JP6485134B2 - Image forming method, image forming apparatus, and process cartridge - Google Patents

Description

  The present invention relates to an image forming method, an image forming apparatus, and a process cartridge.

  An electrophotographic image forming apparatus generally has the following configuration and process. That is, the surface of the electrophotographic photosensitive member is charged to polarity and potential, and the surface of the electrophotographic photosensitive member after charging is selectively discharged by image exposure to form an electrostatic latent image, and then the electrostatic latent image is formed. By attaching toner to the image, the latent image is developed as a toner image, and the toner image is transferred onto a recording medium to be discharged as an image-formed product.

  In recent years, electrophotographic photosensitive members have been used in many fields such as copying machines and laser beam printers because they have the advantage of high speed and high print quality.

  As electrophotographic photosensitive members used in these image forming apparatuses, conventional electrophotographic photosensitive members (inorganic photosensitive members) using inorganic photoconductive materials such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide and the like are known. In recent years, organic photoreceptors (organic photoreceptors) using an organic photoconductive material, which is inexpensive and has excellent advantages in terms of manufacturability and discardability, have become mainstream.

  It has been proposed to provide a protective layer on the surface of the electrophotographic photosensitive member to improve the strength in order to prolong the life of the electrophotographic photosensitive member and to improve the reliability.

The followings have been proposed as material systems for forming the protective layer.
That is, for example, in Patent Document 1, a conductive powder dispersed in a phenolic resin, in Patent Document 2, an organic-inorganic hybrid material, in Patent Document 3, an alcohol-soluble charge transport material and a phenolic resin Are each disclosed.
Further, in Patent Document 4, a cured film of an alkyletherified benzoguanamine / formaldehyde resin, an electron accepting carboxylic acid, or an electron accepting polycarboxylic acid anhydride is disclosed in Patent Document 5, iodine may be used as the benzoguanamine resin. In Patent Document 6, a cured film doped with an organic sulfonic acid compound or ferric chloride is a cured film of a specific additive and a phenol resin, a melamine resin, a benzoguanamine resin, a siloxane resin, or a urethane resin. Is disclosed as a protective layer.

Moreover, in recent years, a protective layer made of an acrylic material attracts attention. For example, in Patent Document 7, a film obtained by curing a liquid containing a photocurable acrylic monomer is disclosed in Patent Document 8. In Patent Document 8, a monomer having a carbon-carbon double bond and charge transfer having a carbon-carbon double bond are disclosed. A film formed by reacting a mixture of a material and a binder resin with the carbon-carbon double bond of the monomer and the carbon-carbon double bond of the charge transfer material by heat or light energy is disclosed in Patent Document In 9, 10, a film formed of a compound obtained by polymerizing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is disclosed as a protective layer. Further, Patent Document 11 discloses an electrophotographic photosensitive member using a film formed of a compound obtained by polymerizing a styryl group-modified hole transporting compound.
Since the hole transportable compound having such chain polymerizable functional groups is strongly influenced by the curing conditions, curing atmosphere, etc., for example, Patent Document 12 heats after irradiation in vacuum or in an inert gas. Patent Document 13 discloses a film formed by heat-curing in an inert gas.
Further, for example, Patent Documents 8 and 14 disclose that the film strength is improved by acrylic-modifying the charge transport material itself to make it crosslinkable and adding a reactive monomer having no charge transport property. ing.

Further, as a protective layer made of a reactant and a cured film, the followings have been proposed.
For example, Patent Document 15 discloses a protective layer containing a compound obtained by modifying a charge transport material itself to a trifunctional or higher polyfunctional and polymerizing the same. Further, Patent Document 16 discloses a technique of using a polymer of a charge transport material having a chain polymerizable functional group for a protective layer, and also contains a fluorine atom as a lubricant to improve friction characteristics. There is disclosed a technique of containing a compound in a protective layer. In addition, Patent Document 17 discloses that the mechanical property and the electrical property can be compatible by making the concentration of the charge transport material having a chain polymerizable functional group slope from the outermost surface toward the inside.

  In addition, Patent Document 18 discloses a first charge transporting compound having one or more chain polymerizable functional groups, and a chain polymerizing amount of 5.0 to 45.0 wt% with respect to the first charge transporting compound. It is disclosed to contain a second charge transportable compound having no functional group. Patent Document 19 discloses that a first charge transporting compound having at least an acryloyloxy group or a methacryloyloxy group and a second charge transporting compound having a hydroxyl group are contained. Patent Document 20 discloses that the crosslinked charge transport layer further contains the same low molecular charge transport material as the charge transport layer.

  Also, in Patent Document 21, Patent Document 22 and Non-patent Document 1, supplying zinc stearate to a photoreceptor having a cross-linked structure on the surface, a solid lubricant such as boron nitride, aluminum oxide, etc. It is disclosed that the retention of an image is enhanced by incorporating such an abrasive in zinc stearate.

  Further, Patent Document 23 discloses an image forming method using a photosensitive member having a crosslinked structure on the surface and a toner containing a fatty acid metal salt having a median diameter of 0.10 μm to 1.00 μm.

  Further, Patent Document 24 discloses the wear rate of a photosensitive member whose surface layer is made of polycarbonate and the content of zinc stearate in the toner.

  Further, Patent Document 25 shows an example in which a photosensitive member on the surface of a crosslinked film having a specific structure and a metal soap such as zinc stearate are added to the toner. Patent Document 26 shows a photosensitive member on the surface of a crosslinked film having a specific structure Discloses a method of controlling the coverage of zinc stearate on the surface of a photoreceptor after printing.

Patent No. 3287678 gazette Unexamined-Japanese-Patent No. 12-019749 Japanese Patent Laid-Open No. 2002-82469 Japanese Patent Application Laid-Open No. 62-251757 Japanese Patent Application Laid-Open No. 7-146564 JP, 2006-84711, A Unexamined-Japanese-Patent No. 5-40360 Unexamined-Japanese-Patent No. 5-216249 JP 2000-206715 A JP, 2001-166509, A Patent No. 2852464 JP 2004-12986 A JP-A-7-72640 JP 2004-302450 A JP 2000-206717 A JP 2001-175016 A Japanese Patent Application Publication No. 2007-86522 JP, 2005-62301, A JP, 2005-62302, A Unexamined-Japanese-Patent No. 2006-138956 JP 2007-79244 A JP 2012-123209 A JP, 2010-54884, A JP 2007-301018 A Unexamined-Japanese-Patent No. 2013-44820 JP, 2013-105046, A

Ricoh Technical Report No. 38, P.I. 37

  The subject of the present invention is a cured film of a composition containing a reactive charge transport material, which comprises an electrophotographic photosensitive member by charging means disposed in contact with or in proximity to the surface of the electrophotographic photosensitive member having the outermost surface layer. The developer includes a charging step of charging the surface of the toner, an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and a toner including toner particles and fatty acid metal salt particles. The electrostatic latent image formed on the surface of the electrophotographic photosensitive member is developed to form a toner image, the transfer step of transferring the toner image to the surface of the recording medium, and the surface of the electrophotographic photosensitive member is contacted In the image forming method, the cleaning step of cleaning the surface of the electrophotographic photosensitive member with a cleaning blade, any of Formula (A1), Formula (B1), Formula (B2), Formula (C1) and Formula (C2) Meet the Even when the low image density or high image density image is repeatedly formed in the high temperature and high humidity environment or the low temperature and low humidity environment as compared with the case where the outermost surface layer does not contain the antioxidant. Providing an image forming method capable of obtaining an image in which

  The above-mentioned subject is solved by the following means.

The invention pertaining to < 1 > is
The surface of an electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed. Charging the surface of the electrophotographic photosensitive member by charging means disposed in contact with or in proximity to the
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged;
Developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer including toner having toner particles and fatty acid metal salt particles to form a toner image;
A transfer step of transferring the toner image to the surface of a recording medium;
A cleaning step of cleaning the surface of the electrophotographic photosensitive member with a cleaning blade in contact with the surface of the electrophotographic photosensitive member;
Have
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
An image forming method which satisfies the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2).
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5

The invention pertaining to < 2 > is
The image forming method according to < 1 > , wherein the fatty acid metal salt particles are particles of zinc stearate having a median diameter of 0.1 μm to 10.0 μm on a volume basis.

The invention relating to < 3 > is
The image forming method according to < 1 > or < 2 > , wherein the antioxidant is a radical polymerization inhibitor.

The invention pertaining to < 4 > is
The image forming method according to any one of < 1 > to < 3 > , wherein the reactive charge transporting material is a chain polymerizable compound having at least a charge transporting skeleton and a chain polymerizable functional group in the same molecule.

The invention pertaining to < 5 > is
The image according to any one of < 1 > to < 3 > , wherein the reactive charge transport material is at least one selected from chain polymerizable compounds represented by the following general formulas (I) and (II) Formation method.

[In general formula (I), F shows a charge transportable skeleton. L represents a divalent linking group containing two or more selected from the group consisting of an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S- and -O- Show. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. m represents an integer of 1 or more and 8 or less. ]

[In general formula (II), F shows a charge transportable skeleton. L 'is a trivalent or tetravalent group derived from alkane or alkene, and an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S-, and -O- The (n + 1) valent linking group containing 2 or more types selected from the group which consists of these is shown. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. m 'represents an integer of 1 or more and 6 or less. n represents an integer of 2 or more and 3 or less. ]

The invention pertaining to < 6 > is
An electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed;
A charging unit disposed in contact with or in close proximity to the surface of the electrophotographic photosensitive member to charge the surface of the electrophotographic photosensitive member;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged;
Developing means for containing a developer containing toner having toner particles and fatty acid metal salt particles, and developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member by the developer to form a toner image When,
A transfer unit that transfers the toner image to the surface of a recording medium;
A cleaning unit having a cleaning blade that contacts the surface of the electrophotographic photosensitive member and cleans the surface of the electrophotographic photosensitive member;
Equipped with
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
An image forming apparatus which satisfies the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2).
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5

The invention concerning < 7 > is
An electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed;
A charging unit disposed in contact with or in close proximity to the surface of the electrophotographic photosensitive member to charge the surface of the electrophotographic photosensitive member;
Developing means for containing a developer containing toner having toner particles and fatty acid metal salt particles, and developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member by the developer to form a toner image When,
A cleaning unit having a cleaning blade that contacts the surface of the electrophotographic photosensitive member and cleans the surface of the electrophotographic photosensitive member;
Equipped with
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
Satisfy the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2),
Process cartridge to be attached to and removed from the image forming apparatus.
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5

According to the invention relating to < 1 > , the cured film of the composition containing the reactive charge transport material, is provided by the charging means disposed in contact with or in proximity to the surface of the electrophotographic photosensitive member having the outermost surface layer. It includes a charging step of charging the surface of the electrophotographic photosensitive member, an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and a toner having toner particles and fatty acid metal salt particles. A developing step of developing an electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer to form a toner image; a transferring step of transferring the toner image to the surface of a recording medium; In the image forming method, the cleaning step of cleaning the surface of the electrophotographic photosensitive member by the cleaning blade in contact with the surface, formula (A1), formula (B1), formula (B2), formula (C1) and formula (A) C2) Even when an image of low image density or high image density is repeatedly formed in a high temperature / high humidity environment or a low temperature / low humidity environment as compared with the case where the image is not satisfied or the outermost surface layer does not contain an antioxidant, There is provided an image forming method capable of obtaining an image in which density unevenness is suppressed.

According to the invention relating to < 2 > , the high-temperature high-humidity environment or the low-temperature low-humidity environment is compared with the case where the toner contains only particles of zinc stearate having a median diameter of 10.0 μm or more on a volume basis as fatty acid metal salt particles. Thus, an image forming method is provided in which an image in which density unevenness is suppressed over a long period of time is obtained even when an image with low image density or high image density is repeatedly formed.

According to the invention concerning < 3 > , when the image of low image density or high image density is repeatedly formed in high temperature high humidity environment or low temperature low humidity environment compared with the case where antioxidant is a peroxide decomposition agent However, there is provided an image forming method capable of obtaining an image in which density unevenness is suppressed over a long period of time.

According to the invention relating to < 4 > or < 5 > , the high-temperature, high-humidity environment or the low-temperature environment as compared with the case where the electrophotographic photosensitive member having the outermost surface layer containing only the nonreactive charge transport material is employed as the charge transport material. There is provided an image forming method capable of obtaining an image in which density unevenness is suppressed over a long period even when an image of low image density or high image density is repeatedly formed in a low humidity environment.

According to the invention relating to < 6 > , the electrophotographic photosensitive member having the outermost surface layer and the surface of the electrophotographic photosensitive member in contact with or in proximity to the cured film of the composition containing the reactive charge transport material. And charging means for charging the surface of the electrophotographic photosensitive member, electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and toner having toner particles and fatty acid metal salt particles Developer containing the developer, and developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member by the developer to form a toner image, and transferring the toner image to the surface of the recording medium (A1), formula (B1), and formula (B2) in an image forming apparatus comprising: a cleaning means having a cleaning blade having a cleaning blade that contacts the surface of the electrophotographic photosensitive member and cleans the surface of the electrophotographic photosensitive member. ), Formula (C1) In the high temperature / high humidity environment or the low temperature / low humidity environment, as compared with the case where either of the formula (C2) is not satisfied or the outermost surface layer of the electrophotographic photosensitive member does not contain an antioxidant, low image density or high image density The present invention provides an image forming apparatus capable of obtaining an image in which density unevenness is suppressed over a long period of time, even when the image of (1) is repeatedly formed.

According to the invention relating to < 7 > , the electrophotographic photosensitive member having the outermost surface layer formed of the cured film of the composition containing the reactive charge transporting material and the electrophotographic photosensitive member arranged in contact with or in proximity to the surface of the electrophotographic photosensitive member And a developer containing a toner having a toner particle and a fatty acid metal salt particle, and an electrostatic charge formed on the surface of the electrophotographic photoconductor by the developer. A process cartridge comprising: developing means for developing a latent image to form a toner image; and cleaning means having a cleaning blade in contact with the surface of the electrophotographic photosensitive member to clean the surface of the electrophotographic photosensitive member. A1) In the case where one of Formula (B1), Formula (B2), Formula (C1) and Formula (C2) is not satisfied or the outermost surface layer of the electrophotographic photosensitive member does not contain an antioxidant, High In a high-humidity environment or low temperature and low humidity environment, even when repeatedly formed an image of low image density or high image density, a process cartridge in which the image with suppressed density unevenness over a long time can be obtained are provided.

FIG. 2 is a schematic partial cross-sectional view showing an example of the layer configuration of the electrophotographic photosensitive member according to the present embodiment. FIG. 6 is a schematic partial cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member according to the present embodiment. FIG. 6 is a schematic partial cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member according to the present embodiment. FIG. 1 is a schematic configuration view showing an example of an image forming apparatus according to the present embodiment. FIG. 6 is a schematic configuration view showing another example of the image forming apparatus according to the present embodiment. It is a schematic diagram which shows an image pattern.

  Hereinafter, the present embodiment, which is an example of the present invention, will be described.

  The image forming method according to the present embodiment includes a charging step of charging the surface of a photosensitive member by a charging unit disposed in contact with or in proximity to the surface of an electrophotographic photosensitive member (hereinafter also referred to as “photosensitive member”); The electrostatic latent image formed on the surface of the photosensitive member is developed to form a toner image by an electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged photosensitive member, and a developer containing toner The image forming apparatus includes a developing step, a transfer step of transferring a toner image to the surface of the recording medium, and a cleaning step of cleaning the surface of the photosensitive member with a cleaning blade in contact with the surface of the photosensitive member.

  Further, an image forming apparatus (an image forming apparatus according to the present embodiment) for performing the image forming method according to the present embodiment is disposed in contact with or in proximity to the photosensitive member and the surface of the photosensitive member. A charging unit for charging, an electrostatic latent image forming unit for forming an electrostatic latent image on the surface of the charged photosensitive member, a developer containing toner, and a static agent formed on the surface of the photosensitive member by the developer Cleaning means having a developing means for developing an electrostatic latent image to form a toner image, a transferring means for transferring a toner image to the surface of a recording medium, and a cleaning blade for contacting the surface of the photosensitive member to clean the surface of the photosensitive member Means.

  A photoreceptor comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, wherein the cured film of a composition containing a reactive charge transport material and an antioxidant is an outermost surface layer. (Hereafter, it is also referred to as "curable photosensitive member"). The developer also includes a toner having toner particles and fatty acid metal salt particles.

Then, in the image forming method according to the present embodiment, the content of the fatty acid metal salt particles with respect to the total mass of the toner is Rmf (mass%), and an image including three image patterns different in image density has a high temperature and high humidity environment. When the film is repeatedly formed, the average wear rate of the photosensitive member is Wh (nm / 1000 rotation), the maximum wear rate of the photosensitive member is Whmax (nm / 1000 rotation), and the minimum wear rate of the photosensitive member is Whmin (nm / 1000 rotation) The average wear rate of the photosensitive member is Wl (nm / 1000 rotation), and the maximum wear rate of the photosensitive member is Wlmax (when the image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment). nm / 1000 rotation), and the minimum wear rate of the photosensitive member is Wlmin (nm / 1000 rotation), formula (A1), formula (B1), formula (B2), formula (C1) And formulas to satisfy the (C2).
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5

Here, “when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment or a low temperature and low humidity environment” is “an environment of high temperature and high humidity (temperature 29 ° C., humidity 85% RH) Or in a low temperature and low humidity environment (temperature 10 ° C., humidity 15% RH environment), as shown in FIG. 6, four dots arranged along the paper lateral feed direction (short direction) on A4 paper as a recording medium It is a thin line image of width 2 mm drawn along the paper longitudinal direction (the image density of only this part is 50%) 100 three times the image density 100 of 18 mm × 9 mm square, with a line and 4-dot space repeated thin line image Repeated fine line images of 4 dot lines and 4 dot spaces arranged along the longitudinal direction of the paper, with 6% solid images 100B and 18 mm × 9 mm squares (image density of only this part is 50%) It is shown that “the output for forming an image consisting of six 100Cs is performed by 70,000 sheets of the A4 sheet in the cross feed direction (short side direction) conveyance.
Here, three solid images 100B and three thin line images 100C are alternately arranged at equal intervals between each of three thin line images 100A of width 2 mm drawn along the paper longitudinal direction. Form an image.
That is, on an A4 sheet as a recording medium, a first image pattern 101A having an image density of 1.4% having only the thin line image 100A, and a second image having an image density of 10% having the thin line image 100A and the solid image 100B. An image is formed of the pattern 101B, and the third image pattern 101C having an image density of 5.7% having the thin line image 100A and the thin line image 100C.
The image density of each image pattern is the average value of the image density in the paper feed direction (in the present embodiment, the cross feed direction (short direction)), and the width is a repetitive thin line image of 4 dot lines and 4 dot spaces. The portion of the first image pattern having only a 2 mm thin line image 100A is (2 × 3 × 50%) / 210 = 1.4% with 2 mm × 3 pieces at an image density of 50% for a paper width of 210 mm. Similarly, the portion of the second image pattern 101B having the thin line image 100A and the solid image 100B is {(2 × 3 × 50%) + (9 × 2 × 100%)} / 210 = 10%, and the thin line The portion of the third image pattern 101C having an image density of 5.7% having the image 100A and the thin line image 100C is {(2 × 3 × 50%) + (9 × 2 × 50%)} / 210 = 5.7% The concentration is defined as

The average wear rate of the photosensitive member, the maximum wear rate of the photosensitive member, and the minimum wear rate of the photosensitive member in each environment are values measured by the following method.
Using an optical film thickness measurement device (line interference film thickness meter), measure the film thickness profile of the outermost surface layer along the longitudinal direction of the photosensitive member in the region corresponding to the image forming region excluding both axial end portions of the photosensitive member Do. The film thickness profile of the outermost surface layer is an average measured at four locations at equal intervals in the circumferential direction of the photosensitive member (four locations of 0 °, 90 °, 180 °, 270 ° when viewed from the cross section of the photosensitive member) Create as a value. Then, under each environment, a film thickness profile of the outermost surface layer is created before and after the output for forming an image, and based on the difference between the film thickness profile of the outermost surface layer before and after the output, the average wear rate of the photosensitive member The maximum wear rate of the photosensitive member and the minimum wear rate of the photosensitive member are respectively calculated.
Each wear rate is calculated by converting it into a wear rate per 1,000 rotations (cycles) of the photosensitive member. That is, each wear rate is a wear rate per 1,000 rotations (cycles) of the photosensitive member.

  Further, in the image forming method (apparatus) according to the present embodiment, with the above configuration, the high temperature and high humidity environment (temperature 29 ° C., humidity 85% RH environment) or low temperature low humidity environment (temperature 10 ° C., humidity 15% RH) Even when an image of low image density (image density 1.4%) or high image density (image density 10%) is repeatedly formed, an image in which uneven density is suppressed over a long period of time can be obtained. The reason for this is not clear, but is presumed to be due to the following reasons.

  Heretofore, there has been known a technique for suppressing the wear of the outermost surface layer of a photosensitive member using a toner containing fatty acid metal salt particles. However, when a cured photoreceptor of a composition containing a reactive charge transport material is used and the curable photoreceptor having the outermost surface layer is applied, the mechanical strength of the outermost surface layer is high, so a high temperature high humidity environment or a low temperature low humidity In any of the environments, the wear of the outermost layer may be excessively suppressed. When the wear of the outermost surface layer is excessively suppressed, the fatty acid metal salt tends to be excessively deposited on the surface of the photoreceptor. In particular, when a contact type or proximity type charging method is employed, the influence of the discharge is strong, and the decrease in the lubricity due to the deterioration of the deposited fatty acid metal salt and the remaining of the discharge product tend to occur.

  For this reason, when an image is repeatedly formed, a mechanical load is applied to the cleaning blade, chipping or abrasion occurs, cleaning failure is caused, and density unevenness of the image is easily generated. This phenomenon is likely to occur when an image including a solid image with high image density is repeatedly formed. It is considered that this is because a solid image is an image with a large amount of toner, and therefore the amount of fatty acid metal salt particles supplied to the surface of the photosensitive member is also increased, which causes partial cleaning failure and tends to cause uneven density. That is, it is considered that the amount of toner supplied to the surface of the photosensitive member (that is, the amount of fatty acid metal salt particles) changes due to the level of the image density, which causes a difference in the ease of occurrence of density unevenness.

  As described above, in an image forming method (apparatus) in which toner containing fatty acid metal salt particles and a curing type photosensitive member are applied, charged by contact type or proximity type charging method and cleaned by a cleaning blade method, high temperature and high humidity environment Or, even when an image of low image density or high image density is repeatedly formed in a low temperature and low humidity environment, the content of fatty acid metal salt particles in the toner (that is, the surface of the photoreceptor) to suppress density unevenness of the image. It has been found that, depending on the amount of fatty acid metal salt particles supplied to (1), it is necessary to wear the outermost surface layer of the photoreceptor appropriately.

  Therefore, in the image forming method according to the present embodiment, Formula (A1), Formula (B1), Formula (B2), Formula (C1) and Formula (C2) are satisfied. That is, the content of fatty acid metal salt particles is controlled to satisfy the formula (A1), and the amount of fatty acid metal salt supplied to the surface of the curing type photoreceptor is limited. Furthermore, when an image including three image patterns having different image densities is repeatedly formed in each environment, the content of fatty acid metal salt particles in the toner is satisfied so as to satisfy Formula (B1) and Formula (B2). The ratio between the amount of fatty acid metal salt particles supplied to the surface of the photosensitive member and the average wear rate of the photosensitive member is controlled to cause the outermost surface layer of the photosensitive member to be worn appropriately. In addition to this, the ratio between the maximum wear rate and the minimum wear rate of the photoreceptor is controlled to satisfy the formula (C1) and the formula (C2), and the difference between the maximum wear rate and the minimum wear rate of the photoreceptor Reduce

  Furthermore, by including an antioxidant in the outermost surface layer of the curable photosensitive layer, the antioxidant exposed from the outermost surface layer due to the abrasion of the outermost surface layer, or the antioxidant scraped from the outermost surface layer is a fatty acid metal It is thought to act on salt. By the action of the antioxidant, deterioration due to oxidation of the fatty acid metal salt attached to the outermost surface layer is suppressed, and the decrease in lubricity is suppressed.

  Thus, protection, wear (refreshing) and lubricity are properly controlled in the outermost surface layer of the curing type photosensitive member. As a result, along with the adhesion of the discharge product to the surface of the curing type photosensitive member, cleaning failure due to wear or chipping of the cleaning blade can be suppressed for a long time.

Therefore, in the image forming method (apparatus) according to the present embodiment, uneven density is suppressed for a long time even when an image of low image density or high image density is repeatedly formed in a high temperature high humidity environment or a low temperature low humidity environment The obtained image is obtained.
Further, in the image forming method (apparatus) according to the present embodiment, since the cleaning failure due to the abrasion or chipping of the cleaning blade is suppressed together with the adhesion of the discharge product to the surface of the photosensitive member, the image flow is also long. It becomes easy to be suppressed.

  In addition, in a color image forming method (apparatus) combining an image forming process (image forming unit) of a cyan image, a magenta image, a yellow image, and a black image which are commonly used generally, about 20% to 30% are color images. That is, in the market, image formation using an image forming process (image forming unit) of a cyan image, a magenta image, a yellow image, and a black image is only about 20% to 30% of the total output. On the other hand, in the market, since the black image forming process (image forming unit) is used for most of the output, uneven density of the image is likely to occur and the life is the shortest. This is the same as the monochrome image forming method (apparatus) using only the black image forming process (image forming unit) is the most used in the market.

As described above, the image forming method (apparatus) according to the present embodiment may be applied to an image forming process (image forming unit) of a black image most used on the market.
Specifically, in the image forming method according to the present embodiment, the electrostatic latent image formed on the surface of the photosensitive member is developed with a developer containing black (black) toner to form a black (black) toner image It is preferable to have a developing step. Further, the image forming apparatus according to the present embodiment contains a developer containing black (black) toner, and develops the electrostatic latent image formed on the surface of the photosensitive member with the developer to obtain black (black) toner It is preferable to include developing means for forming an image.

Here, although the image forming method (apparatus) according to the present embodiment satisfies the formula (A1), it is preferable to satisfy the following formula (A1-2) from the viewpoint of suppression of uneven density of the image, and the following formula (A1) It is further preferable to satisfy -3).
Moreover, although Formula (B1) is satisfy | filled, it is preferable to satisfy a following formula (B1-2) from the point of density nonuniformity suppression of an image, and it is still more preferable to satisfy a following formula (B1-3).
Moreover, although Formula (B2) is satisfy | filled, it is preferable to satisfy a following formula (B2-2) from a point of density nonuniformity suppression of an image, and it is still more preferable to satisfy a following formula (B2-3).
Moreover, although Formula (C1) is satisfied, it is preferable to satisfy the following Formula (C1-2), and it is more preferable to satisfy the following Formula (C1-3), from the viewpoint of suppressing density unevenness of an image.
Moreover, although Formula (C2) is satisfy | filled, it is preferable to satisfy a following formula (C2-2) from the point of density nonuniformity suppression of an image, and it is still more preferable to satisfy a following formula (C2-3).

-Formula (A1): 0.01 <Rmf <0.20
-Formula (A1-2): 0.015 <Rmf <0.19
-Formula (A1-3): 0.02 <Rmf <0.18

Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B1-2): 0.005 <Rmf / Wh <4.950
Formula (B1-3): 0.005 <Rmf / Wh <4.900

Formula (B2): 0.002 <Rmf / Wl <1.000
Formula (B2-2): 0.002 <Rmf / Wl <0.950
Formula (B2-3): 0.002 <Rmf / Wl <0.900

-Formula (C1): 1.0 <Whmax / Whmin <2.5
Formula (C1-2): 1.050 <Whmax / Whmin <2.450
Formula (C1-3): 1.100 <Whmax / Whmin <2.400

-Formula (C2): 1.0 <Wlmax / Wlmin <2.5
Formula (C2-2): 1.050 <Wlmax / Wlmin <2.450
Formula (C2-3): 1.100 <Wlmax / Wlmin <2.400

  In the image forming method (apparatus) according to the present invention, the fatty acid metal salt particles satisfy the formula (B1), the formula (B2), the formula (C1) and the formula (C2) to suppress uneven density of the image. The particles of zinc stearate preferably have a median diameter of 0.1 μm to 10.0 μm on a volume basis. When these particles are applied as fatty acid metal salt particles, the specific surface area of the particles is large, the contact efficiency with the surface of the photoreceptor is improved, and the coverage of fatty acid metal salt on the surface of the photoreceptor is excessively reduced. suppress. For this reason, the photoreceptor is apt to wear appropriately, and the fatty acid metal salt hardly remains on the surface of the photoreceptor. As a result, the above equations are easily satisfied, and density unevenness of the image is easily suppressed.

In the image forming method (apparatus) according to the present invention, from the viewpoint of satisfying the formula (B1), the formula (B2), the formula (C1) and the formula (C2) and suppressing density unevenness of the image, the reactive charge transport material is And a chain polymerizable compound having at least a charge transporting skeleton and a chain polymerizable functional group in the same molecule.
In particular, the chain polymerizable compound is represented by general formulas (I) and (II) from the viewpoint of electrical properties and mechanical strength, together with the same viewpoint (hereinafter referred to as “specific chain polymerizable charge transporting material Or at least one selected from The reason for this is not clear, but is considered to be due to the following reasons.

The outermost surface layer of a cured film of a composition containing at least one selected from a specific chain polymerizable charge transporting material (a film containing a polymer or a crosslinked product of a specific chain polymerizable charge transporting material (in particular, a crosslinked product)) The outermost surface layer has excellent electrical properties and mechanical strength. In addition, thickening of the outermost surface layer (for example, 10 μm or more) is also realized. This is because a specific chain polymerizable charge transport material itself is excellent in charge transport performance, there are few polar groups such as -OH and -NH- that hinder carrier transport, and vinylphenyl having π electrons effective for carrier transport Since the said material is connected by superposition | polymerization by group (styryl group), it is thought that a residual distortion is suppressed and formation of the structural trap which capture | acquires an electric charge is suppressed.
Further, it is considered that the specific chain polymerizable charge transport material is more hydrophobic and less susceptible to moisture than the acrylic material, so that the electrical properties are likely to be maintained over a long period of time.
Furthermore, certain chain-polymerizable charge transport materials are more hydrophobic than acrylic materials and have high affinity with fatty acid metal salts (especially zinc stearate). For this reason, it is considered that the surface of the protective layer (uppermost surface layer) is likely to be coated with a small amount of a fatty acid metal salt (in particular, zinc stearate).
Therefore, a cured film of a composition containing at least one selected from a specific chain-polymerizable charge transport material (a film containing a polymer or a cross-linked product of a specific chain-polymerizable charge transport material) is used as the outermost layer. Then, the electrical properties and mechanical strength of the outermost surface layer tend to be enhanced.

On the other hand, a specific chain polymerizable charge transport material has a styryl group, and this styryl group has high affinity with a general non-reactive charge transport material having no reactive group. That is, it is easy to increase the amount of non-reactive charge transport material contained in the outermost layer. For this reason, adjustment of mechanical strength (for example, reduction in mechanical strength) of the outermost surface layer is easy to be realized by the amount of non-reactive charge transport material to be contained.
In particular, among the specific chain polymerizable charge transporting materials, a material having an ether bond (—O—) as a linking group between the charge transporting skeleton and the chain polymerizable functional group (for example, L in General Formula (I) Materials in which the group shown has an ether bond (-O-), materials in which the group shown in L 'of the general formula (II) has an ether bond (-O-), a compound of the general formula (IIA-a3) or (IIA-) The material having a4) has a low polarity, so it has high charge transportability and high affinity with a non-reactive charge transport material, and adjustment of mechanical strength of the outermost surface layer (eg mechanical strength) Intentional reduction) is easy to realize.

  Therefore, when a specific chain polymerizable charge transport material is applied as the reactive charge transport material, it is effective in controlling the wear rate of the photoreceptor and suppressing the density unevenness of the image so as to satisfy the above formulas. .

  In the image forming method (apparatus) according to the present embodiment, as a method of adjusting the average wear rate, the maximum wear rate, and the minimum wear rate of the photosensitive member, for example, mechanical of the outermost surface layer of the curing type photosensitive member And 2) a method of controlling the type, particle size or content of fatty acid metal salt particles in the toner.

The image forming method according to the present embodiment includes a fixing step of fixing a toner image transferred on the surface of a recording medium; direct transfer in which a toner image formed on the surface of an electrophotographic photosensitive member is directly transferred to a recording medium Method of the method; intermediate transfer in which the toner image formed on the surface of the electrophotographic photosensitive member is primarily transferred onto the surface of the intermediate transfer member, and the toner image transferred onto the surface of the intermediate transfer member is transferred secondarily onto the surface of the recording medium Method of method; method of removing electricity by discharging the light of the surface of the image carrier before charging after transferring the toner image; raising temperature of the electrophotographic photosensitive member to reduce relative temperature Well-known image formation methods, such as the method to have are applied.
In the case of the intermediate transfer method, for example, a primary transfer method of primarily transferring a toner image formed on the surface of the image carrier to the surface of the intermediate transfer member, and a toner transferred to the surface of the intermediate transfer member And D. a secondary transfer method of secondary transfer of the image to the surface of the recording medium.

On the other hand, the image forming apparatus according to the present embodiment includes a fixing unit that fixes the toner image transferred to the surface of the recording medium; and directly transfers the toner image formed on the surface of the electrophotographic photosensitive member to the recording medium Direct transfer type apparatus: Primary transfer of toner image formed on the surface of electrophotographic photosensitive member to the surface of intermediate transfer body, and secondary transfer of toner image transferred on the surface of intermediate transfer body to the surface of recording medium Device of intermediate transfer type; device equipped with charge removing means for removing the charge by irradiating the surface of the image carrier with charge light before charge after transfer of the toner image; raise the temperature of the electrophotographic photosensitive member and reduce the relative temperature A known image forming apparatus such as an apparatus provided with an electrophotographic photosensitive member heating member is applied.
In the case of an intermediate transfer type apparatus, for example, an intermediate transfer member to which a toner image is transferred on the surface, and a primary transfer on which the toner image formed on the surface of the image carrier is primarily transferred to the surface of the intermediate transfer member. A configuration is applied that includes a unit and a secondary transfer unit that secondarily transfers the toner image transferred to the surface of the intermediate transfer member to the surface of the recording medium.

  The image forming method (apparatus) according to the present embodiment may be either an image forming method (apparatus) of a dry developing system or an image forming method (apparatus) of a wet developing system (developing system using a liquid developer). Good.

  In the image forming apparatus according to the present embodiment, for example, the part including the electrophotographic photosensitive member may have a cartridge structure (process cartridge) which is detached from the image forming apparatus. As the process cartridge, for example, a process cartridge including an electrophotographic photosensitive member, a developing unit, and a cleaning unit is preferably used. The process cartridge may include, in addition to the electrophotographic photosensitive member, at least one selected from the group consisting of a charging unit, an electrostatic latent image forming unit, and a transfer unit.

  Hereinafter, although an example of the image forming apparatus according to the present embodiment is shown, the present invention is not limited to this. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

FIG. 4 is a schematic configuration view showing an example of the image forming apparatus according to the present embodiment.
The image forming apparatus 100 according to the present embodiment, as shown in FIG. 4, includes a process cartridge 300 including an electrophotographic photosensitive member 7, an exposure device 9 (an example of an electrostatic latent image forming unit), and a transfer device 40 (primary). A transfer device) and an intermediate transfer member 50 are provided. In the image forming apparatus 100, the exposure device 9 is disposed from the opening of the process cartridge 300 at a position where exposure to the electrophotographic photosensitive member 7 is possible, and the transfer device 40 is the electrophotographic photosensitive member via the intermediate transfer member 50. The intermediate transfer member 50 is disposed so as to be in contact with the electrophotographic photosensitive member 7. Although not shown, it also has a secondary transfer device for transferring the toner image transferred to the intermediate transfer member 50 to a recording medium (for example, a sheet). The intermediate transfer member 50, the transfer device 40 (primary transfer device), and the secondary transfer device (not shown) correspond to an example of the transfer unit.

  In the process cartridge 300 shown in FIG. 4, the electrophotographic photosensitive member 7, the charging device 8 (an example of the charging means), the developing device 11 (an example of the developing means), and the cleaning device 13 (an example of the cleaning means) In favor of The cleaning device 13 has a cleaning blade (an example of a cleaning member) 131, and the cleaning blade 131 is disposed in contact with the surface of the electrophotographic photosensitive member 7.

  In FIG. 4, as an image forming apparatus, a fibrous member 132 (roll-shaped) for supplying the lubricant 14 to the surface of the electrophotographic photosensitive member 7 and a fibrous member 133 for assisting cleaning (flat brush-shaped) An example is shown, but these are arranged as needed.

  Hereinafter, each configuration of the image forming apparatus according to the present embodiment will be described.

(Electrophotographic photosensitive member)
The electrophotographic photosensitive member has a conductive substrate and a photosensitive layer provided on the conductive substrate. The outermost surface layer of the photoreceptor is composed of a cured film of a composition containing a reactive charge transport material.

In the electrophotographic photosensitive member, the outermost surface layer only needs to form the uppermost surface of the electrophotographic photosensitive member itself, and is provided as a layer functioning as a protective layer or a layer functioning as a charge transport layer. When the outermost surface layer is a layer that functions as a protective layer, a photosensitive layer consisting of a charge transport layer and a charge generation layer, or a single-layer type photosensitive layer is provided below the protective layer.
Specifically, in the case where the outermost surface layer is a layer that functions as a protective layer, the photosensitive layer (charge generation layer and charge transport layer, or single-layered photosensitive layer) on the conductive substrate, and the protective layer as the outermost surface layer The aspect in which is formed sequentially is mentioned. On the other hand, in the case where the outermost surface layer is a layer functioning as a charge transport layer, an embodiment in which a charge generation layer and a charge transport layer as the outermost surface layer are sequentially formed on a conductive substrate is mentioned.

  Hereinafter, the electrophotographic photosensitive member according to the embodiment in the case where the outermost surface layer is a layer functioning as a protective layer will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals, and overlapping descriptions will be omitted.

  FIG. 1 is a schematic cross-sectional view showing an example of the electrophotographic photosensitive member according to the present embodiment. 2 to 3 are each a schematic cross-sectional view showing another example of the electrophotographic photosensitive member according to the present embodiment.

  The electrophotographic photoreceptor 7A shown in FIG. 1 is a so-called function separation type photoreceptor (or laminated type photoreceptor), the undercoat layer 1 is provided on the conductive substrate 4, and the charge generation layer 2, charge is formed thereon. It has a structure in which the transport layer 3 and the protective layer 5 are sequentially formed. In the electrophotographic photoreceptor 7A, the charge generation layer 2 and the charge transport layer 3 constitute a photosensitive layer.

Like the electrophotographic photoreceptor 7A shown in FIG. 1, the electrophotographic photoreceptor 7B shown in FIG. 2 is a functionally separated photoreceptor in which the functions are separated into the charge generation layer 2 and the charge transport layer 3.
In the electrophotographic photoreceptor 7B shown in FIG. 2, the undercoat layer 1 is provided on the conductive substrate 4, and the charge transport layer 3, the charge generation layer 2, and the protective layer 5 are sequentially formed thereon. The In the electrophotographic photoreceptor 7B, the charge transport layer 3 and the charge generation layer 2 constitute a photosensitive layer.

  The electrophotographic photoreceptor 7C shown in FIG. 3 contains the charge generation material and the charge transport material in the same layer (single-layer type photosensitive layer 6). In the electrophotographic photoreceptor 7C shown in FIG. 3, the undercoat layer 1 is provided on the conductive substrate 4, and the single-layer type photosensitive layer 6 and the protective layer 5 are sequentially formed thereon. .

In the electrophotographic photosensitive members 7A, 7B and 7C shown in FIGS. 1, 2 and 3, the protective layer 5 is the outermost layer disposed on the side farthest from the conductive substrate 4, and The surface layer is configured as described above.
In the electrophotographic photosensitive members shown in FIGS. 1, 2 and 3, the undercoat layer 1 may or may not be provided.

  Hereinafter, each element will be described based on the electrophotographic photosensitive member 7A shown in FIG. 1 as a representative example. In addition, the code | symbol is abbreviate | omitted and demonstrated.

(Conductive substrate)
As the conductive substrate, for example, a metal plate containing metal (aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum etc.) or alloy (stainless steel etc.), metal drum, metal belt etc. Can be mentioned. In addition, as the conductive substrate, for example, paper coated with a conductive compound (eg, conductive polymer, indium oxide etc.), metal (eg, aluminum, palladium, gold etc.) or alloy, vapor deposition or lamination, resin film, belt etc. Can also be mentioned. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm.

  When the electrophotographic photosensitive member is used for a laser printer, the surface of the conductive substrate has a center line average roughness Ra of not less than 0.04 μm and not more than 0.5 μm for the purpose of suppressing interference fringes generated when irradiating a laser beam. It is preferable to be roughened below. In the case where non-interference light is used as a light source, roughening for preventing interference fringes is not particularly required, but it is more suitable for prolonging the life to suppress generation of defects due to unevenness on the surface of the conductive substrate.

  As a method of surface roughening, for example, wet honing performed by suspending an abrasive in water and spraying it onto a conductive substrate, centerless grinding in which a conductive substrate is pressed against a rotating grindstone and grinding is continuously performed , Anodizing treatment, and the like.

  As a method of roughening, conductive or semiconductive powder is dispersed in a resin without roughening the surface of the conductive substrate to form a layer on the surface of the conductive substrate, and A method of roughening with particles dispersed in a layer may also be mentioned.

  In the surface roughening treatment by anodizing, an oxide film is formed on the surface of a conductive substrate by anodizing in a electrolytic solution using a metal (for example, aluminum) conductive substrate as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily polluted, and has a large resistance fluctuation due to the environment. Therefore, for the porous anodic oxide film, the fine pores of the oxide film are blocked by volume expansion due to hydration reaction with pressurized steam or boiling water (a metal salt such as nickel may be added), and more stable hydrated oxidation It is preferable to carry out the sealing process which changes into a thing.

  The thickness of the anodic oxide film is preferably, for example, 0.3 μm or more and 15 μm or less. When the film thickness is in the above range, the barrier property against injection tends to be exhibited, and the increase in residual potential due to repeated use tends to be suppressed.

The conductive substrate may be treated with an acid treatment liquid or boehmite treatment.
The treatment with the acid treatment solution is carried out, for example, as follows. First, an acidic treatment solution containing phosphoric acid, chromic acid and hydrofluoric acid is prepared. The blending ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acid treatment solution is, for example, 10% by mass to 11% by mass of phosphoric acid, 3% by mass to 5% by mass of chromic acid, and hydrofluoric acid The total concentration of these acids is preferably in the range of 13.5 mass% to 18 mass% in the range of 0.5 mass% to 2 mass%. The processing temperature is preferably, for example, 42 ° C. or more and 48 ° C. or less. The film thickness of the film is preferably 0.3 μm or more and 15 μm or less.

  The boehmite treatment is performed, for example, by immersing in pure water of 90 ° C. to 100 ° C. for 5 minutes to 60 minutes, or by bringing the substrate into contact with heated steam of 90 ° C. to 120 ° C. for 5 minutes to 60 minutes. The film thickness of the film is preferably 0.1 μm to 5 μm. This is further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate and the like. Good.

(Sublayer)
The undercoat layer is, for example, a layer containing inorganic particles and a binder resin.

Examples of the inorganic particles include inorganic particles having a powder resistance (volume resistivity) of 10 ² Ωcm or more and 10 ¹¹ Ωcm or less.
Among these, as the inorganic particles having the above-mentioned resistance value, metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles are preferable, and zinc oxide particles are particularly preferable.

The specific surface area of the inorganic particles according to the BET method is, for example, 10 m ² / g or more.
The volume average particle diameter of the inorganic particles is, for example, 50 nm or more and 2000 nm or less (preferably 60 nm or more and 1000 nm or less).

  The content of the inorganic particles is, for example, preferably 10% by mass to 80% by mass, and more preferably 40% by mass to 80% by mass, with respect to the binder resin.

  The inorganic particles may be subjected to surface treatment. The inorganic particles may be used as a mixture of two or more kinds of particles different in surface treatment or different in particle diameter.

  As a surface treating agent, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, surfactant etc. are mentioned, for example. In particular, a silane coupling agent is preferable, and a silane coupling agent having an amino group is more preferable.

  As a silane coupling agent having an amino group, for example, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-amino Examples include, but are not limited to, propylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, and the like.

  You may use a silane coupling agent in mixture of 2 or more types. For example, a silane coupling agent having an amino group may be used in combination with another silane coupling agent. Other silane coupling agents include, for example, vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glylic Cidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- ( Aminoethyl) -3-aminopropylmethyldimethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, etc., but is limited thereto It is not a thing.

  The surface treatment method using the surface treatment agent may be any known method, and may be either a dry method or a wet method.

  The processing amount of the surface treatment agent is preferably, for example, 0.5% by mass or more and 10% by mass or less with respect to the inorganic particles.

  Here, the undercoat layer preferably contains the electron accepting compound (acceptor compound) together with the inorganic particles, from the viewpoint of enhancing the long-term stability of the electrical characteristics and the carrier blocking property.

Examples of the electron accepting compound include quinone compounds such as chloranil and bromoanil; tetracyanoquinodimethane compounds; 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone and the like 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4- Oxadiazole compounds such as oxadiazole and 2,5-bis (4-diethylaminophenyl) -1,3,4 oxadiazole; xanthone compounds; thiophene compounds; 3,3 ', 5,5'tetra- Examples include diphenoquinone compounds such as t-butyl diphenoquinone; electron transporting substances such as, and the like.
In particular, as the electron accepting compound, a compound having an anthraquinone structure is preferable. As the compound having an anthraquinone structure, for example, a hydroxyanthraquinone compound, an aminoanthraquinone compound, an aminohydroxyanthraquinone compound and the like are preferable. Specifically, for example, anthraquinone, alizarin, quinizarin, anthralphine, and purpurin are preferable.

  The electron accepting compound may be contained in the undercoat layer in a dispersed state with the inorganic particles, or may be contained in a state of being attached to the surface of the inorganic particles.

  Examples of the method for attaching the electron accepting compound to the surface of the inorganic particles include a dry method and a wet method.

  In the dry method, for example, while stirring the inorganic particles with a mixer with large shear force, the electron accepting compound in which the electron accepting compound is dissolved directly or in an organic solvent is dropped, and is sprayed together with dry air or nitrogen gas to make the electron accepting compound It is a method of adhering to the surface of inorganic particles. When dropping or spraying the electron accepting compound, it is preferable to carry out at a temperature equal to or lower than the boiling point of the solvent. After dropping or spraying the electron accepting compound, baking may be further performed at 100 ° C. or higher. Baking is not particularly limited as long as the temperature and time at which electrophotographic characteristics can be obtained.

  In the wet method, for example, while dispersing inorganic particles in a solvent by stirring, ultrasonic waves, sand mill, attritor, ball mill etc., an electron accepting compound is added, stirred or dispersed, and then the solvent is removed to obtain an electron. It is a method of attaching a receptive compound to the surface of an inorganic particle. The solvent removal method is distilled off, for example, by filtration or distillation. After solvent removal, baking may be further performed at 100 ° C. or higher. Baking is not particularly limited as long as the temperature and time at which electrophotographic characteristics can be obtained. In the wet method, the water content of the inorganic particles may be removed before adding the electron accepting compound, and examples thereof include a method of removing while stirring and heating in a solvent, and a method of removing azeotropically with a solvent It can be mentioned.

  The adhesion of the electron accepting compound may be performed before or after the inorganic particles are subjected to surface treatment with a surface treatment agent, and may be performed simultaneously with the adhesion of the electron accepting compound and the surface treatment with the surface treatment agent.

  The content of the electron accepting compound is, for example, preferably 0.01% by mass to 20% by mass, and preferably 0.01% by mass to 10% by mass, with respect to the inorganic particles.

Examples of the binder resin used for the undercoat layer include acetal resin (for example, polyvinyl butyral etc.), polyvinyl alcohol resin, polyvinyl acetal resin, casein resin, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, unsaturated polyester Resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, urea resin, phenol resin, phenol-formaldehyde resin, melamine resin, Known polymer compounds such as urethane resin, alkyd resin, epoxy resin, etc .; zirconium chelate compound; titanium chelate compound; aluminum chelate compound; titanium alkoxide compound ; Organic titanium compounds; known materials silane coupling agent, and the like.
Examples of the binder resin used for the undercoat layer also include a charge transporting resin having a charge transporting group, a conductive resin (for example, polyaniline and the like), and the like.

Among these, as the binder resin used in the undercoat layer, resins insoluble in the coating solvent of the upper layer are preferable, and in particular, urea resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, unsaturated polyester Thermosetting resin such as resin, alkyd resin, epoxy resin; and at least one resin selected from the group consisting of polyamide resin, polyester resin, polyether resin, methacrylic resin, acrylic resin, polyvinyl alcohol resin and polyvinyl acetal resin Resins obtained by reaction with curing agents are preferred.
When two or more of these binder resins are used in combination, the mixing ratio thereof is set as necessary.

The undercoat layer may contain various additives to improve the electrical properties, the environmental stability, and the image quality.
Examples of the additive include known materials such as polycyclic condensation type and electron transporting pigments such as azo type, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents. Be The silane coupling agent is used for surface treatment of the inorganic particles as described above, but may be further added to the undercoat layer as an additive.

  As a silane coupling agent as an additive, for example, vinyltrimethoxysilane, 3-methacryloxypropyl-tris (2-methoxyethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- Examples include (aminoethyl) -3-aminopropylmethylmethoxysilane, N, N-bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, 3-chloropropyltrimethoxysilane and the like.

  As a zirconium chelate compound, for example, zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate, Examples thereof include zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt And titanium lactate, titanium lactate ethyl ester, titanium triethanolaminate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethylacetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate) and the like.

  These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

The undercoat layer preferably has a Vickers hardness of 35 or more.
The surface roughness (ten-point average roughness) of the undercoat layer is adjusted from 1 / 4n (n is the refractive index of the upper layer) to 1 / 2λ of the exposure laser wavelength λ used for moire image suppression It is good to be done.
Resin particles and the like may be added to the undercoat layer to adjust the surface roughness. Examples of the resin particles include silicone resin particles and crosslinked polymethyl methacrylate resin particles. In addition, the surface of the undercoat layer may be polished to adjust the surface roughness. The polishing method may, for example, be buffing, sand blasting, wet honing or grinding.

  The formation of the undercoat layer is not particularly limited, and a known formation method is used. For example, a coating film of the undercoat layer forming solution obtained by adding the above components to a solvent is formed, and the coating film is dried. And by heating if necessary.

As a solvent for preparing the coating liquid for undercoat layer formation, known organic solvents such as alcohol solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone solvents, ketone alcohol solvents, ether solvents Solvents, ester solvents and the like can be mentioned.
Specific examples of these solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, Common organic solvents such as n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like can be mentioned.

  Examples of the method of dispersing the inorganic particles when preparing the coating liquid for forming the undercoat layer include known methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill and a paint shaker.

  As a method of applying the coating liquid for undercoat layer formation on a conductive substrate, for example, blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method Etc. can be mentioned.

  The thickness of the undercoat layer is, for example, preferably in the range of 15 μm or more, more preferably 20 μm to 50 μm.

(Intermediate layer)
Although not shown, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer.
The intermediate layer is, for example, a layer containing a resin. Examples of the resin used for the intermediate layer include acetal resin (eg, polyvinyl butyral etc.), polyvinyl alcohol resin, polyvinyl acetal resin, casein resin, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, Polymer compounds such as polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin and the like can be mentioned.
The intermediate layer may be a layer containing an organometallic compound. Examples of the organic metal compound used for the intermediate layer include organic metal compounds containing metal atoms such as zirconium, titanium, aluminum, manganese and silicon.
The compounds used in these intermediate layers may be used alone or as a mixture or polycondensate of a plurality of compounds.

  Among these, the intermediate layer is preferably a layer containing an organic metal compound containing a zirconium atom or a silicon atom.

The formation of the intermediate layer is not particularly limited, and a known formation method is used. For example, a coating film of the coating liquid for forming an intermediate layer in which the above components are added to a solvent is formed, and the coating film is dried. It does by heating according to.
As a coating method for forming the intermediate layer, a usual method such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method or a curtain coating method is used.

  The film thickness of the intermediate layer is preferably set, for example, in the range of 0.1 μm to 3 μm. The intermediate layer may be used as a subbing layer.

(Charge generation layer)
The charge generation layer is, for example, a layer containing a charge generation material and a binder resin. The charge generation layer may be a vapor deposition layer of a charge generation material. The deposition layer of the charge generation material is suitable when using an incoherent light source such as an LED (Light Emitting Diode) or an organic EL (Electro-Luminescence) image array.

  Examples of the charge generating material include azo pigments such as bisazo and trisazo; condensed aromatic pigments such as dibromoanthanthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; trigonal selenium and the like.

  Among these, in order to cope with laser exposure in the near infrared region, it is preferable to use a metal phthalocyanine pigment or a metal free phthalocyanine pigment as the charge generation material. Specifically, for example, hydroxygallium phthalocyanine disclosed in JP-A-5-263007, JP-A-5-279591 and the like; chlorogallium phthalocyanine disclosed in JP-A-5-98181 and the like; JP-A-5 Dichlorotin phthalocyanine disclosed in -140472, JP-A-5-140473 and the like; and titanyl phthalocyanine disclosed in JP-A-4-189873 and the like are more preferable.

  On the other hand, in order to cope with laser exposure in the near ultraviolet region, as charge generating materials, condensed aromatic pigments such as dibromoanthanthrone; thioindigo pigments; porphyrazine compounds; zinc oxide; trigonal selenium; The bisazo pigment etc. which were disclosed by 2004-78147 and Unexamined-Japanese-Patent No. 2005-181992 are preferable.

  Even when using an incoherent light source such as an LED or an organic EL image array having a central wavelength of light emission at 450 nm or more and 780 nm or less, the above charge generation material may be used, but from the viewpoint of resolution When the thin film is used as a thin film, the electric field strength in the photosensitive layer becomes high, and the charge reduction due to the charge injection from the base material tends to cause an image defect called a so-called black point. This becomes remarkable when using a charge generating material which is a p-type semiconductor such as trigonal selenium, phthalocyanine pigment and the like and tends to cause dark current.

On the other hand, when an n-type semiconductor such as a fused aromatic pigment, a perylene pigment, or an azo pigment is used as a charge generation material, it is difficult to generate a dark current, and an image defect called black point can be suppressed even in a thin film. . Examples of the n-type charge generation material include compounds (CG-1) to (CG-27) described in paragraphs [0288] to [0291] of JP 2012-155282 A, and examples thereof It is not limited.
In addition, determination of n-type is determined by the polarity of the photocurrent which flows using the time of flight method normally used, and makes what is easy to flow an electron as a carrier rather than a hole be n-type.

The binder resin used for the charge generation layer is selected from a wide range of insulating resins, and the binder resin is selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinyl anthracene, polyvinyl pyrene, polysilane and the like. You may choose.
As the binder resin, for example, polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol and aromatic divalent carboxylic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, Polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, etc. may be mentioned. Here, "insulating" means that the volume resistivity is 10 ¹³ Ωcm or more.
These binder resins may be used alone or in combination of two or more.

  The compounding ratio of the charge generating material to the binder resin is preferably in the range of 10: 1 to 1:10 by mass ratio.

  The charge generation layer may further contain known additives.

  The formation of the charge generation layer is not particularly limited, and a known formation method is used. For example, a coating film of the charge generation layer forming coating solution obtained by adding the above components to a solvent is formed, and the coating film is dried. And by heating if necessary. Note that the charge generation layer may be formed by vapor deposition of a charge generation material. The formation of the charge generation layer by vapor deposition is particularly suitable when a fused aromatic pigment or perylene pigment is used as the charge generation material.

  As a solvent for preparing a coating solution for forming a charge generation layer, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, acetic acid n And -butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like. These solvents are used singly or in combination of two or more.

As a method of dispersing particles (for example, charge generation material) in the coating liquid for charge generation layer formation, for example, media dispersion machines such as ball mill, vibration ball mill, attritor, sand mill, horizontal sand mill, stirring, ultrasonic dispersion machine Medialess dispersing machines such as roll mills and high pressure homogenizers are used. Examples of the high-pressure homogenizer include a collision method in which the dispersion is dispersed by causing liquid-liquid collision or liquid-wall collision in a high pressure state to disperse it, and a penetration method in which a fine flow path is dispersed by being dispersed in a high pressure state.
At the time of this dispersion, it is effective to set the average particle diameter of the charge generation material in the coating solution for forming a charge generation layer to 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. .

  As a method of applying the coating liquid for charge generation layer formation on the undercoat layer (or on the intermediate layer), for example, blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating And ordinary methods such as curtain coating method.

  The film thickness of the charge generation layer is, for example, preferably in the range of 0.1 μm to 5.0 μm, more preferably 0.2 μm to 2.0 μm.

(Charge transport layer)
The charge transport layer is, for example, a layer containing a charge transport material and a binder resin. The charge transport layer may be a layer containing a polymeric charge transport material.

  As charge transport materials, quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone and the like; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds Cyanovinyl compounds; electron transporting compounds such as ethylene compounds. Examples of the charge transporting material also include hole transporting compounds such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds and the like. Although these charge transport materials are used individually by 1 type or in 2 or more types, it is not limited to these.

  From the viewpoint of charge mobility, a triarylamine derivative represented by the following structural formula (a-1) and a benzidine derivative represented by the following structural formula (a-2) are preferable as the charge transport material.

In structural formula (a-1), Ar ^T1 , Ar ^T2 and Ar ^T3 each independently represent a substituted or unsubstituted aryl group, -C ₆ H ₄ -C (R ^T4 ) = C (R ^T5 ) (R ^{T 5} ) ^T6), or _{-C 6 H 4 -CH = CH-} CH = C (R T7) shows the ^{(R T8).} R ^T4 , R ^T5 , R ^T6 , R ^T7 and R ^T8 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.
As a substituent of each said group, a halogen atom, a C1-C5 alkyl group, and a C1-C5 alkoxy group are mentioned. Moreover, as a substituent of said each group, the substituted amino group substituted by the C1-C3 alkyl group is also mentioned.

In Structural Formula (a-2), ^RT91 and ^RT92 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ^T101 , R ^T102 , R ^T111 and R ^T112 are each independently ^substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkyl group having 1 to 2 carbon atoms A substituted amino group, a substituted or unsubstituted aryl group, -C ( ^RT12 ) = C ( ^RT13 ) ( ^RT14 ), or -CH = CH-CH = C ( ^RT15 ) ( ^RT16 ); R ^T12 , R ^T13 , R ^T14 , R ^T15 and R ^T16 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Tm1, Tm2, Tn1 and Tn2 each independently represent an integer of 0 or more and 2 or less.
As a substituent of each said group, a halogen atom, a C1-C5 alkyl group, and a C1-C5 alkoxy group are mentioned. Moreover, as a substituent of said each group, the substituted amino group substituted by the C1-C3 alkyl group is also mentioned.

Here, among the triarylamine derivative represented by the structural formula (a-1) and the benzidine derivative represented by the structural formula (a-2), in particular, “—C ₆ H ₄ —CH = CH—CH = Triarylamine derivatives having C (R ^T7 ) (R ^T8 ), and benzidine derivatives having “—CH = CH—CH = C (R ^T15 ) (R ^T16 )” are preferred in view of charge mobility.

  As the polymer charge transport material, known materials having charge transportability such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester-based polymer charge transport materials disclosed in JP-A-8-176293, JP-A-8-208820 and the like are particularly preferable. The polymer charge transport material may be used alone or in combination with a binder resin.

The binder resin used for the charge transport layer is polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N -Vinylcarbazole, polysilane and the like can be mentioned. Among these, polycarbonate resin or polyarylate resin is suitable as the binder resin. These binder resins may be used alone or in combination of two or more.
The compounding ratio of the charge transport material to the binder resin is preferably 10: 1 to 1: 5 in mass ratio.

  The charge transport layer may further contain known additives.

  The formation of the charge transport layer is not particularly limited, and a known formation method is used. For example, a coating film of a charge transport layer forming solution obtained by adding the above components to a solvent is formed, and the coating film is dried. Perform by heating if necessary.

  As a solvent for preparing a coating liquid for charge transport layer formation, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; ketones such as acetone and 2-butanone; methylene chloride, chloroform, ethylene chloride and the like Commonly used organic solvents such as halogenated aliphatic hydrocarbons; cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These solvents are used alone or in combination of two or more.

  As a coating method at the time of coating the coating liquid for charge transport layer formation on the charge generation layer, blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain A usual method such as a coating method may be mentioned.

The thickness of the charge transport layer is, for example, preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 30 μm.
.

(Protective layer)
The protective layer (uppermost surface layer) is the outermost layer of the electrophotographic photosensitive member, and is formed of a cured film of a composition containing a reactive charge transport material and an antioxidant. That is, the protective layer contains the polymer or crosslinked body (preferably crosslinked body) of the reactive charge transporting material.
The protective layer may be composed of a composition further including other additives such as a nonreactive charge transport material and a compound having an unsaturated bond (unsaturated double bond). That is, the protective layer may further contain other additives such as a polymer or a crosslinked product (preferably a crosslinked product) of a reactive charge transport material and a compound having an unsaturated bond, and a nonreactive charge transport material. Good.

  In addition, as a curing method of a cured film, radical polymerization by heat, light, radiation or the like is performed. If the reaction is adjusted so as not to proceed too fast, the mechanical strength and electrical properties of the protective layer (uppermost surface layer) will be improved, and the occurrence of film unevenness and wrinkles will be suppressed, so radical generation will be relatively slow. It is preferred to polymerize under the conditions which occur. From this point of view, thermal polymerization which is easy to control the polymerization rate is preferable. That is, the composition for forming a cured film constituting the protective layer (uppermost surface layer) may contain a thermal radical generator or a derivative thereof.

  Hereinafter, details of each element of the protective layer (uppermost surface layer) formed of the cured film will be described.

-Reactive charge transport material-
The reactive charge transporting material is selected from known materials as long as it is a compound having a charge transporting backbone and a reactive group in the same molecule. Here, as the reactive group, a chain polymerizable group may be mentioned, and for example, it may be a functional group capable of radical polymerization, for example, a functional group having a group containing at least a carbon double bond. Specifically, the chain polymerizable group is not particularly limited as long as it is a functional group capable of radical polymerization, for example, a functional group having a group containing at least a carbon double bond. Specific examples thereof include a group containing at least one selected from a vinyl group, a vinyl ether group, a vinyl thioether group, a styryl group, an acryloyl group, a methacryloyl group, and derivatives thereof. Among them, the chain polymerizable functional group is preferably a group containing at least one selected from a vinyl group, a styryl group, an acryloyl group, a methacryloyl group, and derivatives thereof because they are excellent in the reactivity. Is preferred. In addition, as a reactive group, an epoxy group, -OH, -OR (wherein R represents an alkyl group), -NH ₂ , -SH, -COOH, -SiR ^{Q 1} _3- ^Q _n (OR ^{Q 2} ) ^Q _n [wherein And R ^Q1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, and R ^Q2 represents a hydrogen atom, an alkyl group, or a trialkylsilyl group. _Qn represents an integer of 1 to 3] and the like, as well as known reactive groups.
The charge transporting skeleton is not particularly limited as long as it has a known structure in an electrophotographic photosensitive member, and, for example, nitrogen-containing hole transport such as triarylamine compounds, benzidine compounds, and hydrazone compounds. It is a skeleton derived from a sex compound and has a structure conjugated to a nitrogen atom. Among these, a triarylamine skeleton is preferable.

  As the reactive charge transporting material, a chain polymerizable compound having at least a charge transporting skeleton and a chain polymerizable functional group in the same molecule is preferable from the viewpoint of suppressing unevenness in density of an image. In particular, among the chain polymerizable compounds, from the same viewpoint as well as from the viewpoint of electrical properties and mechanical strength, from a specific chain polymerizable charge transporting material (chain polymerizable compounds represented by general formulas (I) and (II)) At least one selected is preferred.

-Specific Reactive Charge Transport Material-
The specific reactive charge transporting material is at least one selected from the group consisting of the reactive compounds represented by the general formulas (I) and (II).

In the general formula (I), F represents a charge transporting skeleton.
L represents a divalent linking group containing two or more selected from the group consisting of an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S- and -O- Show. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group.
m represents an integer of 1 or more and 8 or less.

In the general formula (II), F represents a charge transporting skeleton.
L 'is a trivalent or tetravalent group derived from alkane or alkene, and an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S-, and -O- And (n + 1) -valent linking group containing two or more selected from the group consisting of R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. The term "trivalent or tetravalent group derived from alkane or alkene" means a group obtained by removing three or four hydrogen atoms from alkane or alkene. The same applies below.
m 'represents an integer of 1 or more and 6 or less. n represents an integer of 2 or more and 3 or less.

  In the general formulas (I) and (II), F represents a charge transportable skeleton, that is, a structure having charge transportability, specifically, phthalocyanine compounds, porphyrin compounds, azobenzene compounds, triarylamine compounds Examples include structures having charge transportability such as compounds, benzidine compounds, arylalkane compounds, aryl substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, quinone compounds, fluorenone compounds, and the like.

As the linking group represented by L in the general formula (I), for example,
A bivalent linking group in which —C (= O) —O— intervenes in an alkylene group,
A divalent linking group in which —C (= O) —N (R) — intervenes in an alkylene group,
A divalent linking group in which —C (= O) —S— is present in an alkylene group,
A divalent linking group in which -O- is interposed in an alkylene group,
A divalent linking group in which -N (R)-is interposed in an alkylene group,
A divalent linking group in which -S- is interposed in an alkylene group,
Can be mentioned.
The linking group represented by L is, in the alkylene group, —C (= O) —O—, —C (= O) —N (R) —, —C (= O) —S—, —O Two — or —S— groups may be present.

Specific examples of the linking group represented by L in the general formula (I) include
*-(CH ₂ ) _p -C (= O) -O- (CH ₂ ) _q- ,
_{* - (CH 2) p -O} -C (= O) - (CH 2) r -C (= O) -O- (CH 2) q -,
_{* - (CH 2) p -C} (= O) -N (R) - (CH 2) q -,
*-(CH ₂ ) _p -C (= O) -S- (CH ₂ ) _q- ,
*-(CH ₂ ) _p -O- (CH ₂ ) _q- ,
*-(CH ₂ ) _p -N (R)-(CH ₂ ) _q- ,
*-(CH ₂ ) _p -S- (CH ₂ ) _q- ,
*-(CH ₂ ) _p -O- (CH ₂ ) _r -O- (CH ₂ ) _q-
Etc.
Here, in the linking group represented by L, p represents an integer of 0 or 1 or more and 6 or less (preferably 1 or more and 5 or less). q represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less). r represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less).
In the linking group represented by L, "*" indicates a site linked to F.

On the other hand, as the linking group represented by L ′ in the general formula (II), for example,
(N + 1) -valent linking group in which —C (= O) —O— intervenes in a branched alkylene group;
(N + 1) -valent linking group in which —C (= O) —N (R) — intervenes in a branched alkylene group;
(N + 1) -valent linking group in which —C (= O) —S— intervenes in a branched alkylene group;
(N + 1) -valent linking group in which —O— is interposed in a branched alkylene group,
(N + 1) -valent linking group in which —N (R) — intervenes in a branched alkylene group;
(N + 1) -valent linking group in which —S— is interposed in a branched alkylene group,
Can be mentioned.
Note that the linking group represented by L ′ is a branched alkylene group in which —C (= O) —O—, —C (= O) —N (R) —, —C (= O) Two groups of -S-, -O- or -S- may be present.

Specific examples of the linking group represented by L ′ in the general formula (II) include
*-(CH ₂ ) _p -CH [C (= O) -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH = C [C (= O) -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [C (= O) -N (R)-(CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [C (= O) -S- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH = C [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [(CH ₂ ) _r -N (R)-(CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [(CH ₂ ) _r -S- (CH ₂ ) _q- ] ₂ ,


*-(CH ₂ ) _p -O-C [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₃
*-(CH ₂ ) _p -C (= O) -O-C [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₃
Etc.
Here, in the linking group represented by L ′, p represents an integer of 0 or 1 or more and 6 or less (preferably 1 or more and 5 or less). q represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less). r represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less). s represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less).
In the linking group represented by L ′, “*” indicates a site linked to F.

Among these, as the linking group represented by L ′ in the general formula (II),
*-(CH ₂ ) _p -CH [C (= O) -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH = C [C (= O) -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₂ ,
*-(CH ₂ ) _p -CH = C [(CH ₂ ) _r -O- (CH ₂ ) _q- ] ₂ ,
Is good.
Specifically, a group linked to the charge transporting skeleton represented by F of the reactive compound represented by the general formula (II) (a group represented by the general formula (IIA-a) corresponds) is a compound represented by the following general formula ( A group represented by IIA-a1), the following formula (IIA-a2), the following formula (IIA-a3), or the following formula (IIA-a4) is preferable.

In the general formulas (IIA-a1) or (IIA-a2), X ^k1 represents a divalent linking group. kq1 represents an integer of 0 or 1. X ^k2 represents a divalent linking group. kq2 represents an integer of 0 or 1.
Here, the divalent linking group represented by X ^k1 and X ^k2 is, for example, — (CH ₂ ) _p — (wherein p represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less)) It can be mentioned. The bivalent linking group also includes an alkyleneoxy group.

In the general formulas (IIA-a3) or (IIA-a4), X ^k3 represents a divalent linking group. kq3 represents an integer of 0 or 1; X ^k4 represents a divalent linking group. kq4 represents an integer of 0 or 1;
Here, the divalent linking group represented by X ^k3 and X ^k4 is, for example, — (CH ₂ ) _p — (wherein p represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less)) It can be mentioned. The bivalent linking group also includes an alkyleneoxy group.

In the linking groups represented by L and L ′ in the general formulas (I) and (II), the alkyl group represented by R in “—N (R) —” has 1 to 5 carbon atoms (preferably 1 to 5). 4 or less) of the linear or branched alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group and a butyl group.
Examples of the aryl group represented by R in "-N (R)-" include aryl groups having 6 to 15 carbon atoms (preferably 6 to 12 carbon atoms), and specific examples thereof include phenyl and toluyl Groups, xylyl groups, naphthyl groups and the like.
Examples of the aralkyl group include aralkyl groups having 7 to 15 carbon atoms (preferably 7 to 14 carbon atoms), and specific examples include a benzyl group, a phenethyl group, and a biphenyl methylene group.

In the general formulas (I) and (II), m preferably represents an integer of 1 or more and 6 or less.
m ′ preferably represents an integer of 1 or more and 6 or less.
n preferably represents an integer of 2 or more and 3 or less.

Next, preferred compounds of the reactive compounds represented by formulas (I) and (II) will be described.
As the reactive compound represented by the general formulas (I) and (II), a reactive compound having a charge transporting skeleton (structure having charge transporting property) derived from a triarylamine compound as F is preferable.
Specifically, as the reactive compound represented by the general formula (I), a compound represented by the general formula (I-a), a general formula (I-b), a general formula (I-c), and a general formula (I-d) At least one compound selected from the group consisting of the reactive compounds shown in) is preferred.
On the other hand, as the reactive compound represented by the general formula (II), the reactive compound represented by the general formula (II-a) is preferable.

Reactive Compound Represented by General Formula (I-a) The reactive compound represented by General Formula (I-a) will be described.
When the reactive compound represented by the general formula (I-a) is applied as the specific reactive charge transport material, the deterioration of the electrical characteristics due to the environmental change is easily suppressed. Although the reason is not clear, it is considered as follows.
First, since the reactive compound having a (meth) acrylic group, which has been conventionally used, has high hydrophilicity of the (meth) acrylic group with respect to the portion of the skeleton that exhibits charge transport performance during polymerization, It is considered that some kind of layer separation state is formed, which is an obstacle to hopping conduction. For this reason, the charge transportable film containing a polymer or a cross-linked product of a reactive compound having a (meth) acrylic group is reduced in charge transport efficiency, and further, environmental stability is reduced due to partial adsorption of water and the like. It is considered to be a thing.
On the other hand, the reactive compound represented by the general formula (I-a) has a vinyl-based chain polymerizable group which is not strongly hydrophilic, and further, has a skeleton which exhibits charge transport performance in one molecule. Are connected to one another by a flexible linking group which does not have a conjugated bond such as an aromatic ring or a conjugated double bond. Such a structure is considered to achieve efficient charge transport performance and high strength, and to suppress the formation of a layer separation state during polymerization. As a result, the protective layer (uppermost surface layer) containing the polymer or cross-linked product of the reactive compound represented by the general formula (I-a) is excellent in both charge transport performance and mechanical strength, and further, charge It is thought that environmental dependence (temperature and humidity dependence) of transport performance can be reduced.
From the above, it is considered that when the reactive compound represented by the general formula (I-a) is applied, the deterioration of the electrical characteristics caused by the environmental change is easily suppressed.

In the general formula (I-a), Ar ^{a1 to} Ar ^a4 each independently represent a substituted or unsubstituted aryl group. Ar ^a5 and Ar ^a6 each independently represent a substituted or unsubstituted arylene group. Xa represents a divalent linking group formed by combining a group selected from an alkylene group, -O-, -S- and an ester. Da represents a group represented by the following general formula (IA-a). Each of ac1 to ac4 independently represents an integer of 0 or more and 2 or less. However, the total number of Da is 1 or 2.

In the general formula (IA-a), L ^a is a *-(CH ₂ ) _an -O-CH _2- , and is a divalent linking group which is linked to a group represented by Ar ^{a1 to} Ar ^a4 by * Indicates an represents an integer of 1 or 2.

Hereinafter, the details of the general formula (I-a) will be described.
In General Formula (I-a), the substituted or unsubstituted aryl groups represented by Ar ^{a1 to} Ar ^a4 may be identical to or different from each other.
Here, as a substituent in the substituted aryl group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, as other than "Da" Examples thereof include a substituted phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom.

In the general formula (I-a), Ar ^{a1 to} Ar ^a4 are preferably any of the following structural formulas (1) to (7).
The following structural formulas (1) to (7) collectively represent “-(Da) _ac1 ” to “-(Da) _ac1 ” that can be linked to each of Ar ^{a1 to} Ar ^a4. _C ) It shows it with ".

In structural formulas (1) to (7), R ¹¹ is substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms 1 type selected from the group which consists of a phenyl group, an unsubstituted phenyl group, and a C7 or more and 10 or less carbon aralkyl group is shown. R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms And 1 type selected from the group consisting of an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom. R ¹⁴ each independently represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, This represents one selected from the group consisting of an aralkyl group having 7 to 10 carbon atoms and a halogen atom. Ar represents a substituted or unsubstituted arylene group. s represents 0 or 1. t represents an integer of 0 or more and 3 or less. Z ′ represents a divalent organic linking group.

  Here, in the formula (7), as Ar, one represented by the following structural formula (8) or (9) is preferable.

In Structural Formulas (8) and (9), R ¹⁵ and R ¹⁶ each independently represent an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy having 1 to 4 carbon atoms. Represents one selected from the group consisting of a phenyl group substituted by a group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and t1 and t2 each represent an integer of 0 to 3; Show.

  Moreover, in Formula (7), what is shown by either of following Structural formula (10)-(17) is preferable.

In Structural Formulas (10) to (17), R ¹⁷ and R ¹⁸ each independently represent an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy having 1 to 4 carbon atoms. 1 group selected from the group consisting of a phenyl group substituted by a group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom. W represents a divalent group. Each of q1 and r1 independently represents an integer of 1 or more and 10 or less. t3 and t4 each represent an integer of 0 or more and 3 or less.

  In Structural Formulas (16) to (17), W is preferably any one of divalent groups represented by the following Structural Formulas (18) to (26). However, u shows an integer of 0 or more and 3 or less in Formula (25).

In the substituted or unsubstituted arylene group represented by Ar ^a5 and Ar ^a6 in the general formula (I-a), as the arylene group, the target position from the aryl group exemplified in the description of Ar ^{a1 to} Ar ^a4 And an arylene group from which one hydrogen atom has been removed.
Further, examples of the substituent in the substituted arylene group, in the description of Ar ^a1 to Ar ^a4, is the same as those listed as the substituent other than "Da" in the substituted aryl group.

In General Formula (I-a), the divalent linking group represented by Xa is a divalent group formed by combining an alkylene group, or a group selected from an alkylene group, -O-, -S-, and an ester. It is a linking group which does not contain a conjugated bond such as an aromatic ring or a conjugated double bond.
Specifically, examples of the divalent linking group represented by Xa include an alkylene group having 1 to 10 carbon atoms, and in addition, an alkylene group having 1 to 10 carbon atoms and -O-, -S-, -O The bivalent group which combines the group chosen from -C (= O)-and -C (= O) -O- is also mentioned.
When the divalent linking group represented by Xa is an alkylene group, this alkylene group may have a substituent such as alkyl, alkoxy or halogen, and two of these substituents are bonded to each other, It may have a structure like a divalent linking group represented by Structural Formula (26) described as a specific example of W in Structural Formulas (16) to (17).

Reactive Compound Represented by General Formula (I-b) The reactive compound represented by General Formula (I-b) will be described.
When the reactive compound represented by the general formula (I-b) is applied as a specific reactive charge transport material, abrasion of the protective layer (uppermost surface layer) is suppressed and generation of density unevenness of the image is easily suppressed. Become. Although the reason is not clear, it is considered as follows.
First, if the bulky charge transport skeleton and the polymerization site (styryl group) are structurally close and rigid (rigid), the polymerization sites are less likely to move with each other, residual strain due to curing reaction tends to remain, and the charge transport skeleton is distorted. It is thought that the change of the level of HOMO (highest occupied molecular orbital) that leads to carrier transport occurs, and as a result, the energy distribution is likely to be spread (energy disorder: large σ).
On the other hand, when a methylene group or an ether group is used, flexibility can be obtained in the molecular structure and a small σ can be easily obtained. Furthermore, the methylene group and the ether group are compared to an ester group, an amide group, etc. It is considered that the dipole moment (dipole moment) is small, this effect also contributes to the reduction of σ, and the electrical characteristics are improved. In addition, flexibility is added to the molecular structure to increase the freedom of movement of the reaction site (reaction site), and the reaction rate is also considered to be a high strength film by improving the reaction rate. The structure which interposes a flexible connection chain between the polymerization site is preferred.
Therefore, the reactive compound represented by the general formula (I-b) is considered to increase the molecular weight of the molecule itself by the curing reaction, to make it difficult to move the center of gravity and to have a high degree of freedom of styryl group. As a result, the protective layer (uppermost surface layer) containing the polymer or crosslinked product of the reactive compound represented by the general formula (I-b) is considered to be excellent in electrical properties and to have high strength.
From the above, it is considered that when the reactive compound represented by the general formula (I-b) is applied, the wear of the protective layer (the outermost surface layer) is suppressed and the generation of the density unevenness of the image is easily suppressed.

In the general formula (I-b), Ar ^{b1 to} Ar ^b4 each independently represent a substituted or unsubstituted aryl group. Ar ^b5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Db represents a group represented by the following general formula (IA-b). bc1 to bc5 each independently represent an integer of 0 or more and 2 or less. bk represents 0 or 1; However, the total number of Db is 1 or 2.

In the general formula (IA-b), L ^b contains a group represented by *-(CH ₂ ) _bn -O- and is a divalent linking group which is linked to the group represented by Ar ^{b1 to} Ar ^b5 by * Indicates bn represents an integer of 3 or more and 6 or less.

Hereinafter, the details of the general formula (I-b) will be described.
In the general formula (I-b), the substituted or unsubstituted aryl group represented by Ar ^{b1 to} Ar ^b4 is a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) Is the same as
Ar ^b5 represents a substituted or unsubstituted aryl group when bk is 0, and as the substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) or It is the same as an unsubstituted aryl group.
Ar ^b5 represents a substituted or unsubstituted arylene group when bk is 1, and examples of the substituted or unsubstituted arylene group include the substituents represented by Ar ^a5 and Ar ^a6 in the general formula (I-a) or It is the same as an unsubstituted arylene group.

Next, the details of the general formula (IA-b) will be described.
Examples of the divalent linking group represented by L ^b in general formula (IA-b) include
*-(CH ₂ ) _bp -O-,
*-(CH ₂ ) _bp -O- (CH ₂ ) _bq -O-
Etc.
Here, in the linking group represented by L ^b , bp represents an integer of 3 or more and 6 or less (preferably 3 or more and 5 or less). bq represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less).
In the linking group represented by L ^b , “*” indicates a site linked to the group represented by Ar ^{b1 to} Ar ^b5 .

Reactive Compound Represented by General Formula (I-c) The reactive compound represented by General Formula (I-c) will be described.
When the reactive compound represented by the general formula (Ic) is applied as the specific reactive charge transport material, the surface is less likely to be scratched even when used repeatedly, and image quality deterioration is easily suppressed. Although the reason is not clear, it is considered as follows.
First, when forming the outermost surface layer containing a polymer or a crosslinked product of a specific reactive charge transport material, the film shrinkage associated with the polymerization reaction or the crosslinking reaction, the charge transport structure and the structure around the chain polymerizable group It is believed that cohesion of Therefore, when the electrophotographic photosensitive member surface is subjected to mechanical load in repeated use, the film itself is abraded or the chemical structure in the molecule is cut, and the film contraction and aggregation state change, and the electrophotographic photosensitive member It is considered that the electrical characteristics of the image quality change and image quality deterioration occurs.
On the other hand, since the reactive compound represented by the general formula (Ic) has a styrene skeleton as a chain polymerizable group, it has good compatibility with the aryl group which is the main skeleton of the charge transport material, and the film shrinks. It is considered that the aggregation of the charge transport structure and the chain polymerizable group peripheral structure due to polymerization reaction or crosslinking reaction is suppressed. As a result, it is considered that an electrophotographic photosensitive member having a protective layer (uppermost surface layer) containing a polymer or a crosslinked product of a reactive compound represented by the general formula (I-c) suppresses image quality deterioration due to repeated use. Be
In addition, the reactive compound represented by the general formula (I-c) has a charge transporting skeleton and a styrene skeleton, and a specific group such as -C (= O)-, -N (R)-or -S- By linking through a linking group, it is considered that interaction between a specific group and a nitrogen atom in the charge transportable backbone, or between specific groups, etc. will occur. As a result, The protective layer (uppermost surface layer) containing the polymer or crosslinked product of the reactive compound shown in c) is considered to further improve the strength.
From the above, it is considered that when the reactive compound represented by the general formula (I-c) is applied, scratches are not easily generated on the surface even when used repeatedly, and image quality deterioration is easily suppressed.
In addition, specific groups such as -C (= O)-, -N (R)-and -S- are caused by their polarity and hydrophilicity, and are factors that cause degradation of image quality under charge transportability and high humidity conditions. However, since the reactive compound represented by the general formula (I-c) has a styrene skeleton which is more hydrophobic than (meth) acrylic or the like as a chain polymerizable group, the charge transportability is deteriorated or the previous cycle is It is considered that image quality deterioration such as afterimage phenomenon (ghost) due to history is unlikely to occur.

In the general formula (I-c), Ar ^{c1 to} Ar ^c4 each independently represent a substituted or unsubstituted aryl group. Ar ^c5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Dc represents a group represented by the following general formula (IA-c). cc1 to cc5 each independently represent an integer of 0 or more and 2 or less. ck shows 0 or 1. However, the total number of Dc is 1 or more and 8 or less.

In the general formula (IA-c), L ^C is —C (= O) —, —N (R) —, —S—, and —C (= O) —, —O—, —N (R And b) a divalent linking group containing one or more groups selected from the group consisting of a group in combination with-or -S-. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group.

Hereinafter, the details of the general formula (I-c) will be described.
In the general formula (I-c), the substituted or unsubstituted aryl group represented by Ar ^{c1 to} Ar ^c4 is a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) Is the same as
Ar ^c5 represents a substituted or unsubstituted aryl group when ck is 0, and examples of the substituted or unsubstituted aryl group include a substituent represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) or It is the same as an unsubstituted aryl group.
Ar ^c5 represents a substituted or unsubstituted arylene group when ck is 1, and examples of the substituted or unsubstituted arylene group include the substituents represented by Ar ^a5 and Ar ^a6 in the general formula (I-a) or It is the same as an unsubstituted arylene group.
The total number of Dc is preferably 2 or more, more preferably 4 or more from the viewpoint of obtaining a protective layer (uppermost surface layer) having higher strength. In general, when the number of chain polymerizable groups in one molecule is too large, as the polymerization (crosslinking) reaction proceeds, the molecules become difficult to move, the chain polymerization reactivity decreases, and the proportion of unreacted chain polymerizable groups increases. In view of the above, the total number of Dc is preferably 7 or less, more preferably 6 or less.

Next, the details of the general formula (IA-c) will be described.
In the general formula (IA-c), ^examples of the divalent linking group represented by L ^c include —C (= O) —, —N (R) —, —S— and —C (= O) — It is a bivalent coupling group containing the group (Hereafter, "specific coupling group" is called) which combined and -O-, -N (R)-, or -S-.
Here, the specific linking group is, for example, -C (= O)-, -N (R)-or -S- from the viewpoint of the balance between the strength and polarity (hydrophilicity and hydrophobicity) of the protective layer (uppermost surface layer). , -C (= O) -O-, -C (= O) -N (R)-, -C (= O) -S-, -O-C (= O) -O-, -O-C (= O) -N (R)-is preferable, preferably -N (R)-, -S-, -C (= O) -O-, -C (= O) -N (H)-,- C (= O) -O-, more preferably -C (= O) -O-.
And, as the divalent linking group represented by L ^c , for example, a specific linking group, a residue of a saturated hydrocarbon (including any of linear, branched and cyclic) or an aromatic hydrocarbon, and oxygen And a divalent linking group formed by combining atoms, and among these, it is formed by combining a specific linking group, a residue of a linear saturated hydrocarbon, and an oxygen atom. The linking group is preferred.
The total number of carbon atoms contained in the divalent linking group represented by L ^c is, for example, 1 or more and 20 or less, preferably 2 or more, from the viewpoint of the density of the styrene skeleton in the molecule and the chain polymerization reactivity. It is below.

Specific examples of the divalent linking group represented by L ^c in general formula (IA-c) include
*-(CH ₂ ) _cp -C (= O) -O- (CH ₂ ) _cq- ,
*-(CH ₂ ) _cp -O-C (= O)-(CH ₂ ) _cr -C (= O) -O- (CH ₂ ) _cq- ,
*-(CH ₂ ) _cp -C (= O) -N (R)-(CH ₂ ) _cq- ,
*-(CH ₂ ) _cp -C (= O) -S- (CH ₂ ) _cq- ,
*-(CH ₂ ) _cp -N (R)-(CH ₂ ) _cq- ,
*-(CH ₂ ) _cp -S- (CH ₂ ) _cq- ,
Etc.
Here, in the linking group represented by L ^c , cp represents an integer of 0 or 1 or more and 6 or less (preferably 1 or more and 5 or less). cq represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less). cr represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less).
In the linking group represented by L ^c , “*” indicates a site linked to a group represented by Ar ^{c1 to} Ar ^c5 .

Among these, in the general formula (IA-c), as the divalent linking group represented by L ^c , *-(CH ₂ ) _cp -C (= O) -O-CH ₂ -is preferable. That is, the group represented by the general formula (IA-c) is preferably a group represented by the following general formula (IA-c1). However, in the general formula (IA-c1), cp1 represents an integer of 0 or more and 4 or less.

Reactive Compound Represented by General Formula (Id) The reactive compound represented by General Formula (Id) will be described.
When the reactive compound represented by the general formula (I-d) is applied as a specific reactive charge transport material, abrasion of the protective layer (uppermost surface layer) is suppressed and generation of density unevenness of the image is easily suppressed. Become. Although the reason is not clear, it is thought that it is based on the same reason as the reactive compound represented by the general formula (I-b).
In particular, since the reactive compound represented by the general formula (I-d) has a total number of Dd as large as 3 or more and 8 or less as compared with the general formula (I-b) It is considered that the crosslinked network is easily formed, and the wear of the protective layer (the outermost surface layer) is more easily suppressed.

In the general formula (Id), Ar ^{d1 to} Ar ^d4 each independently represent a substituted or unsubstituted aryl group. Ar ^d5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Dd represents a group represented by the following general formula (IA-d). dc1 to dc5 each independently represent an integer of 0 or more and 2 or less. dk shows 0 or 1. However, the total number of Dd is 3 or more and 8 or less.

In the general formula (IA-d), L ^d includes a group represented by *-(CH ₂ ) _dn -O-, and a divalent linking group linked to a group represented by Ar ^{d1 to} Ar ^d5 by * is represented by Show. dn represents an integer of 1 or more and 6 or less.

Hereinafter, the details of the general formula (I-d) will be described.
In the general formula (Id), the substituted or unsubstituted aryl group represented by Ar ^{d1 to} Ar ^d4 is a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) Is the same as
Ar ^d5 represents a substituted or unsubstituted aryl group when dk is 0, and as the substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) or It is the same as an unsubstituted aryl group.
Ar ^d5 represents a substituted or unsubstituted arylene group when dk is 1, and examples of the substituted or unsubstituted arylene group include the substituents represented by Ar ^a5 and Ar ^a6 in the general formula (I-a) or It is the same as an unsubstituted arylene group.
The total number of Dd is preferably 4 or more from the viewpoint of obtaining a stronger protective layer (uppermost surface layer).

Next, the details of the general formula (IA-d) will be described.
Examples of the divalent linking group represented by L ^d in general formula (IA-d) include
*-(CH ₂ ) _dp -O-,
*-(CH ₂ ) _dp -O- (CH ₂ ) _dq -O-
Etc.
Here, in the linking group represented by L ^d , dp represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less). dq represents an integer of 1 or more and 6 or less (preferably 1 or more and 5 or less).
In the linking group represented by L ^d , “*” indicates a site linked to the group represented by Ar ^{d1 to} Ar ^d5 .

Reactive Compound Represented by General Formula (II-a) The reactive compound represented by General Formula (II-a) will be described.
When a reactive compound represented by the general formula (II) (in particular, the general formula (II-a)) is applied as a specific reactive charge transport material, deterioration of the electrical characteristics is easily suppressed even when used repeatedly over a long period of time Become. Although the reason is not clear, it is considered as follows.
First, the reactive compound represented by the general formula (II) (in particular, the general formula (II-a)) has two or three chain-polymerizable reactive groups via one linking group from the charge transporting skeleton. It is a compound having (styrene group).
Therefore, the reactive compound represented by the general formula (II) (particularly, the general formula (II-a)) was polymerized or crosslinked by the presence of the linking group while maintaining a high degree of curing and the number of crosslinking sites. It is considered that it is difficult to cause distortion in the charge transportable skeleton at the time, and it becomes easy to realize both the high curing degree and the excellent charge transport performance.
In addition, charge transfer compounds having a (meth) acrylic group, which have been conventionally used, are susceptible to strain as described above, and the reactive site is highly hydrophilic and the charge transport site is highly hydrophobic. Therefore, the reactive compound represented by the general formula (II) (especially, the general formula (II-a)) has a styrene group as a reactive group, while microscopic phase separation (micro phase separation) is likely to occur. In addition, it has a structure that has a linking group that is less likely to cause distortion in the charge transporting skeleton when it is cured (crosslinked), and because both the reactive site and the charge transporting site are hydrophobic. Since separation hardly occurs, it is considered that efficient charge transport performance and high strength can be achieved. As a result, the protective layer (uppermost surface layer) containing the polymer or the crosslinked product of the reactive compound represented by the general formula (II) (in particular, the general formula (II-a)) is excellent in mechanical strength and has a charge It is considered that transport performance (electrical characteristics) is more excellent.
From the above, it is considered that when the reactive compound represented by the general formula (II) (particularly, the general formula (II-a)) is applied, deterioration of the electrical characteristics is easily suppressed even when used repeatedly over a long period of time.

In the general formula (II-a), Ar ^{k1 to} Ar ^k4 each independently represent a substituted or unsubstituted aryl group. ^Ark5 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted arylene group. Dk represents a group represented by the following general formula (IIA-a). kc1 to kc5 each independently represent an integer of 0 or more and 2 or less. kk represents 0 or 1; However, the total number of Dk is 1 or more and 8 or less.

In the general formula (IIA-a), L ^k is a trivalent or tetravalent group derived from an alkane or alkene, and an alkylene group, an alkenylene group, -C (= O)-, -N (R)- The (kn + 1) valent connecting group containing 2 or more types selected from the group which consists of -S-, and -O- is shown. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. kn represents an integer of 2 or more and 3 or less.

Hereinafter, the details of the general formula (II-a) will be described.
In the general formula (II-a), the substituted or unsubstituted aryl group represented by Ar ^{k1 to} Ar ^k4 is a substituted or unsubstituted aryl group represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) Is the same as
^Ark5 represents a substituted or unsubstituted aryl group when kk is 0, and ^examples of the substituted or unsubstituted aryl group include a substituent represented by Ar ^{a1 to} Ar ^a4 in the general formula (I-a) or It is the same as an unsubstituted aryl group.
Ar ^k5 represents a substituted or unsubstituted arylene group when kk is 1, and ^examples of the substituted or unsubstituted arylene group include the substituents represented by Ar ^a5 and Ar ^a6 in the general formula (I-a) or It is the same as an unsubstituted arylene group.
The total number of Dk is preferably 2 or more, and more preferably 4 or more from the viewpoint of obtaining a protective layer (uppermost surface layer) with higher strength. In general, when the number of chain polymerizable groups in one molecule is too large, as the polymerization (crosslinking) reaction proceeds, the molecules become difficult to move, the chain polymerization reactivity decreases, and the proportion of unreacted chain polymerizable groups increases. In view of the above, the total number of Dk is preferably 7 or less, more preferably 6 or less.

Next, the details of the general formula (IIA-a) will be described.
The (kn + 1) -valent linking group ^represented by L ^k in General Formula (IIA-a) is, for example, the same as the (n + 1) -valent linking group represented by L ′ in General Formula (II).

The specifics of the specific reactive charge transport material are shown below.
Specifically, the charge transporting skeleton F of the general formulas (I) and (II) (for example, a portion corresponding to the skeleton of Da in the general formula (I-a) or Dk of the general formula (II-a)) And the specific examples of the functional group linked to the charge transporting skeleton F (for example, the portion corresponding to Da in the general formula (I-a) or Dk of the general formula (II-a)) Specific examples of the reactive compound represented by (II) and (II) are shown, but not limited thereto.
The “*” portion of the specific example of the charge transporting skeleton F of the general formulas (I) and (II) means that the “*” portion of the functional group linked to the charge transporting skeleton F is linked. Do.
That is, for example, the exemplified compound (I-b) -1 is shown as a specific example of the charge transporting skeleton F: (M1) -1, and a specific example of the functional group: (R2) -1, The typical structure shows the following structure.

  First, specific examples of the charge transporting skeleton F will be shown below.

  Next, specific examples of the functional group linked to the charge transporting skeleton F will be shown.

  Next, specific examples of the compound represented by the general formula (I), specifically the general formula (I-a), are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically the general formula (I-b) are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically the general formula (Ic), are shown.

  Next, specific examples of the compound represented by the general formula (I), specifically the general formula (I-d), are shown.

  Next, specific examples of the compound represented by the general formula (II), specifically the general formula (II-a), are shown.

The specific chain polymerizable charge transporting material (in particular, the chain polymerizable compound represented by the general formula (I)) is synthesized, for example, as follows.
That is, a specific chain polymerizable charge transport material is synthesized by, for example, etherification with a precursor carboxylic acid or alcohol and the corresponding chloromethylstyrene or the like.

  The synthesis route of the exemplified compound (I-d) -22 of the specific chain polymerizable charge transporting material is shown below as an example.

The arylamine compound carboxylic acid can be selected, for example, from the ester group of the arylamine compound as described in, for example, J. Chem. It is obtained by hydrolysis using a basic catalyst (NaOH, K ₂ CO ₃ etc.), an acidic catalyst (eg phosphoric acid, sulfuric acid etc.) as described in 51 et al.
At this time, various solvents may be mentioned as the solvent, but it is preferable to use an alcohol such as methanol, ethanol, ethylene glycol or the like, or to mix water with this.
Furthermore, when the solubility of the arylamine compound is low, methylene chloride, chloroform, toluene, dimethyl sulfoxide, ether, tetrahydrofuran or the like may be added.
Although the amount of the solvent is not particularly limited, for example, 1 part by mass or more and 100 parts by mass or less, preferably 2 parts by mass or more and 50 parts by mass or less with respect to 1 part by mass of the arylamine compound containing an ester group Good.
The reaction temperature is set, for example, in the range of room temperature (eg, 25 ° C.) to the boiling point of the solvent, and is preferably 50 ° C. or more in view of the reaction rate.
The amount of the catalyst is not particularly limited, but for example, 0.001 part by mass or more and 1 part by mass or less, preferably 0.01 part by mass or more, preferably 1 part by mass to 1 part by mass of the arylamine compound containing an ester group. It is good to use by the mass part or less.
After the hydrolysis reaction, when hydrolysis is carried out with a basic catalyst, the formed salt is neutralized with an acid (for example, hydrochloric acid etc.) and liberated. Furthermore, after thoroughly washing with water, it is used after being dried or, if necessary, after recrystallization purification with an appropriate solvent such as methanol, ethanol, toluene, ethyl acetate, acetone or the like, it is used after drying It is also good.

  The alcohol form of the arylamine compound can be selected, for example, from the ester group of the arylamine compound as described in, for example, J. Chem. The compound is synthesized by reduction to the corresponding alcohol using lithium aluminum hydride, sodium borohydride and the like as described in 10 et al.

  For example, when introducing a reactive group by an ester bond, the usual esterification in which an arylamine compound carboxylic acid and hydroxymethylstyrene are dehydrated and condensed by an acid catalyst, an arylamine compound carboxylic acid and a halogenated methylstyrene May be condensed using a base such as pyridine, piperidine, triethylamine, dimethylaminopyridine, trimethylamine, DBU, sodium hydride, sodium hydroxide or potassium hydroxide, but the method using halogenated methylstyrene is It is preferred because the product is suppressed.

It is preferable to add 1 equivalent or more, preferably 1.2 equivalents or more, more preferably 1.5 equivalents or more of halogenated methylstyrene to the acid of the arylamine compound carboxylic acid, and the base is 0 based on the halogenated methylstyrene. .8 equivalent or more and 2.0 equivalents or less, preferably 1.0 equivalent or more and 1.5 equivalents or less.
As the solvent, aprotic polar solvents such as N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as diethyl ether and tetrahydrofuran, toluene, chlorobenzene, 1 Aromatic solvents such as chloro naphthalene are effective, and the amount is 1 to 100 parts by mass, preferably 2 to 50 parts by mass with respect to 1 part by mass of the arylamine compound carboxylic acid. It is good to be used.
The reaction temperature is not particularly limited. After completion of the reaction, the reaction solution is poured into water, extracted with a solvent such as toluene, hexane or ethyl acetate and washed with water, and further, if necessary, purification is performed using an adsorbent such as activated carbon, silica gel, porous alumina or activated clay. May be

Moreover, when introduce | transducing by ether bond, arylamine compound alcohol and halogenated methylstyrene, bases, such as a pyridine, a piperidine, a triethylamine, a dimethylamino pyridine, a trimethylamine, DBU, sodium hydride, sodium hydroxide, potassium hydroxide, etc. It is preferable to use a method of condensation using
It is preferable to add 1 equivalent or more, preferably 1.2 equivalents or more, more preferably 1.5 equivalents or more of halogenated methylstyrene to the alcohol of the arylamine compound alcohol, and the base is preferably 0. It is preferable to use 8 equivalents or more and 2.0 equivalents or less, preferably 1.0 equivalent or more and 1.5 equivalents or less.
As the solvent, aprotic polar solvents such as N-methyl pyrrolidone, dimethyl sulfoxide and N, N-dimethylformamide, ketone solvents such as acetone and methyl ethyl ketone, ether solvents such as diethyl ether and tetrahydrofuran, toluene, chlorobenzene, 1 Aromatic solvents such as chloro naphthalene are effective, and it is used in the range of 1 to 100 parts by mass, preferably 2 to 50 parts by mass with respect to 1 part by mass of the arylamine compound alcohol Good thing.
The reaction temperature is not particularly limited. After completion of the reaction, the reaction solution is poured into water, extracted with a solvent such as toluene, hexane or ethyl acetate and washed with water, and further, if necessary, purification is performed using an adsorbent such as activated carbon, silica gel, porous alumina or activated clay. May be

The specific chain polymerizable charge transporting material (in particular, the chain polymerizable compound represented by the general formula (II)) is, for example, a general charge transporting material synthesis method shown below (formylation, esterification, etherification, hydrogenation) ) To be synthesized.
Formylation: reaction suitable for introducing a formyl group to an aromatic compound having an electron donating group, a heterocyclic compound, and an alkene. It is common to use DMF and phosphorus oxytrichloride, and the reaction temperature is usually from room temperature (eg, 25 ° C.) to about 100 ° C.
Esterification: condensation reaction of an organic acid with a compound containing a hydroxyl group such as an alcohol or phenol. It is preferable to use a method in which the equilibrium is biased to the ester side by coexisting a dehydrating agent or removing water out of the system.
Etherification: The Williamson synthesis method in which an alkoxide and an organic halogen compound are condensed is common.
Hydrogenation: A method of reacting hydrogen with unsaturated bonds using various catalysts.

  In addition to the specific chain-polymerizable charge transporting material, the reactive charge transporting material may be a compound described in [0110] to [0153] of JP-A-2012-163693, and [0055] of Japanese Patent No. 4365960. Compounds described in [0082], compounds described in [0040] to [0043] of Patent No. 4429340, compounds described in [0161] to [0166] of JP-A No. 2013-195762, etc. It can be mentioned.

  The content of the specific chain-polymerizable charge transporting material is, for example, preferably 40% by mass or more and 95% by mass or less, preferably 50% by mass or more and 95% by mass or less based on the total solid content in the composition for layer formation. It is below.

-Antioxidant-
As an antioxidant, a typical example thereof has the property of preventing or suppressing the action of oxygen under the conditions of light, heat, discharge and the like to an oxidizing substance present inside or on the surface of the electrophotographic photosensitive member It is a substance.
As an antioxidant, a radical polymerization inhibitor, a peroxide decomposition agent, etc. are mentioned. Examples of the radical polymerization inhibitor include known antioxidants such as hindered phenol type antioxidants, hindered amine type antioxidants, diallylamine type antioxidants, diallyldiamine type antioxidants, hydroquinone type antioxidants, etc. Be As a peroxide decomposition agent, organic sulfur type (for example, thioether type) antioxidant, phosphoric acid type (for example, phosphite type) antioxidant, dithiocarbamate type antioxidant, thiourea type antioxidant, benzimidazole type oxidation Well-known antioxidants, such as an inhibitor, are mentioned.
Among these, as an antioxidant, a radical polymerization inhibitor is preferable in terms of suppressing deterioration due to oxidation of a fatty acid metal salt and suppressing density unevenness of an image, particularly hindered phenol-based antioxidants, hindered amine-based antioxidants Agents are preferred. The antioxidant may be an antioxidant having two or more different skeletons having an antioxidant action in one molecule (for example, an antioxidant having a hindered phenol skeleton and a hindered amine skeleton).

The hindered phenolic antioxidant is described.
A hindered phenolic antioxidant is a compound having a hindered phenol ring.

  In the hindered phenol-based antioxidant, the hindered phenol ring is, for example, a phenol ring in which an alkyl group having 4 to 8 carbon atoms (eg, a branched alkyl group having 4 to 8 carbon atoms) is substituted at least one It is. More specifically, the hindered phenol ring is, for example, a phenol ring in which the position ortho to the phenolic hydroxyl group is substituted with a tertiary alkyl group (for example, a tert-butyl group).

As a hindered phenolic antioxidant,
1) Antioxidants having one hindered phenol ring,
2) A connecting group consisting of a linear or branched divalent or tetravalent aliphatic hydrocarbon group having two or more and four or less hindered phenol rings, or a divalent or tetravalent or less aliphatic group A linking group in which at least one of an ester bond (—C (= O) O—) and an ether bond (—O—) intervenes between carbon-carbon bonds of a hydrocarbon group, and is a hindered group of 2 or more and 4 or less Dephenol ring-linked antioxidant 3) Two or more but four or less hindered phenol rings, and one benzene ring (unsubstituted or substituted benzene ring substituted with an alkyl group or the like) or an isocyanurate ring And antioxidants in which 2 or more and 4 or less hindered phenol rings are linked via a benzene ring or an isocyanurate ring and an alkylene group, respectively, and the like.

  Specific examples of hindered phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, 3,5-di-t-butyl-4-hydroxybiphenyl, n -Octadecyl-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) -propionate, 2,2'-methylenebis (6-t-butyl-4-methylphenol), 2-t- Butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-t-butylphenol) , 4,4'-thio-bis- (3-methyl-6-t-butylphenol), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) iso Anurate, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, 3,9-bis [2- [3- (3-t-butyl -4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane and the like.

  Examples of commercially available hindered phenolic antioxidants include Irganox 1076, Irganox 1010, Irganox 1098, Irganox 245, Irganox 1330, Irganox 3114, Irganox 1076 (all manufactured by Ciba Japan Ltd.) And Sumilyzer MDP-S (manufactured by Sumitomo Chemical Co., Ltd.).

The hindered amine antioxidant is described.
The hindered amine antioxidant is an antioxidant having a hindered amine skeleton. The hindered amine skeleton includes, for example, a piperidyl skeleton substituted with an alkyl group. Specifically, examples of the hindered amine skeleton include a tetraalkyl piperidyl skeleton in which two hydrogen atoms bonded to a carbon atom ortho to the nitrogen atom are each substituted with an alkyl group. In this tetraalkyl piperidyl skeleton, a hydrogen atom bonded to a nitrogen atom may be substituted by an alkyl group or an alkoxy group.

  Specific examples of hindered amine antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethyl-4-piperidyl). Sebacate, 1- [2- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-) Hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] Undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, succinic acid dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6 6-Tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl} {(2,2,6 , 6-Tetramethyl-4-piperidyl) imino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-) Hydroxybenzyl) -2-n-butyl malonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [ N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like can be mentioned.

  Commercially available hindered amine antioxidants include, for example, Sanol LS2626, Sanol LS765, Sanol LS770, Sanol LS744 (all manufactured by Sanko Lifetech Co., Ltd.), Tinuvin 144, Tinuvin 622 LD (all manufactured by Ciba Japan Ltd.), Mark LA57, mark LA67, mark LA62, mark LA68, mark LA63 (all manufactured by Adeka Corp.) can be mentioned.

  In addition, as a commercial item of thioether system antioxidant, Sumilyzer TPS and Sumilyzer TP-D (above, Sumitomo Chemical Co., Ltd. make) are mentioned, for example. As a phosphite type | system | group antioxidant, mark 2112, mark PEP-8, mark PEP-24G, mark PEP-36, mark 329K, mark HP-10 (above, Adeka company make) etc. are mentioned.

  One of these antioxidants may be used alone, or two or more thereof may be used in combination.

  The content of the antioxidant is 0.01% by mass or more with respect to the total solid content in the composition for layer formation from the viewpoint of suppressing deterioration due to oxidation of the fatty acid metal salt and suppressing density unevenness of the image. % By mass or less is preferable, and preferably 0.05% by mass or more and 10% by mass or less. In addition, when content of antioxidant is 20 mass% or less, the fall of the charge transport of a protective layer (upper surface layer) will be suppressed, and the increase of a residual potential will be easy to be suppressed. In addition, the reduction in strength of the protective layer (uppermost surface layer) is also easily suppressed.

-Resin particle-
The film constituting the protective layer (uppermost surface layer) may contain resin particles.
Examples of resin particles include particles of polycarbonate resin such as bisphenol A type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-styrene copolymer resin, Acrylonitrile-butadiene copolymer resin, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-acrylic copolymer, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate- Particles of insulating resin such as maleic anhydride resin, silicone resin, phenol-formaldehyde resin, polyacrylamide resin, polyamide resin, chlorine rubber, polyvinyl carbazole, poly And particles of an organic photoconductive polymer such as vinyl anthracene and polyvinyl pyrene.
These resin particles may be hollow particles.
Moreover, resin particles may use these resin individually or in mixture of 2 or more types.

The film constituting the protective layer (the outermost surface layer) may contain fluorine-containing resin particles as the resin particles.
Examples of fluorine-containing resin particles include fluoroolefin homopolymers and copolymers of two or more types, and particles of copolymers of one or more types of fluoroolefins and a non-fluorinated monomer .

  As the fluoroolefin, for example, tetrafluoroethylene (TFE), perfluorovinylether, hexafluoropropylene (HFP), perhaloolefin such as chlorotrifluoroethylene (CTFE), vinylidene fluoride (VdF), trifluoroethylene, fluoride Non-perfluoro olefins, such as vinyl, etc. are mentioned, VdF, TFE, CTFE, HFP etc. are preferable.

  On the other hand, as non-fluorinated monomers, for example, hydrocarbon based olefins such as ethylene, propylene and butene, cyclohexyl vinyl ether (CHVE), ethyl vinyl ether (EVE), alkyl vinyl ethers such as butyl vinyl ether and methyl vinyl ether, polyoxyethylene allyl ether (POEAE), alkenyl vinyl ethers such as ethyl allyl ether, vinyltrimethoxysilane (VSi), organotrisilicon compounds having a reactive α, β-unsaturated group such as vinyltriethoxysilane, vinyltris (methoxyethoxy) silane, acrylic acid Acrylic acid esters such as methyl and ethyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, vinyl acetate, vinyl benzoate, "BEOBA (Trade name, vinyl ester manufactured by Shell Corp.) and the like, and alkyl vinyl ether, allyl vinyl ether, vinyl ester, organosilicon compounds having a reactive α, β-unsaturated group are preferable.

  Among these, those having a high fluorination ratio are preferable, and polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro (alkyl vinyl ether) copolymer (PFA) , Ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and the like. Among these, PTFE, FEP and PFA are particularly preferable.

The fluorine-containing resin particles may be, for example, particles (fluorine resin aqueous dispersion) prepared by a method such as emulsion polymerization of fluorine-based monomer as it is, or it may be used after being sufficiently washed with water and then dried. Good.
The average particle size of the fluorine-containing resin particles is preferably 0.01 μm or more and 100 μm or less, and particularly preferably 0.03 μm or more and 5 μm or less.
In addition, the average particle diameter of the said fluorine-containing resin particle says the value measured using laser diffraction type particle size distribution measuring apparatus LA-700 (made by Horiba, Ltd.).

  As the fluorine-containing resin particles, commercially available ones may be used. For example, as the PTFE particles, Fluon L173JE (manufactured by Asahi Glass Co., Ltd.), mite ion THV-221AZ, mite ion 9205 (manufactured by Sumitomo 3M company), Rubron L2, ル bron L5 (made by Daikin) etc. are mentioned.

  The fluorine-containing resin particles may be irradiated with laser light having an oscillation wavelength in the ultraviolet region. It does not specifically limit about the laser beam irradiated to a fluorine-containing resin particle, For example, an excimer laser etc. are mentioned. As excimer laser light, ultraviolet laser light having a wavelength of 400 nm or less, particularly 193 nm or more and 308 nm or less is preferable. In particular, KrF excimer laser light (wavelength: 248 nm) and ArF excimer laser light (wavelength: 193 nm) are preferable. Excimer laser light irradiation is usually performed at room temperature (25 ° C.) in the air, but may be performed in an oxygen atmosphere.

The irradiation conditions of the excimer laser light depend on the kind of the fluorocarbon resin and the degree of surface modification required, but the general irradiation conditions are as follows.
Fluence: 50 mJ / cm ² / pulse or more Incident energy: 0.1 J / cm ² or more Shot number: 100 or less

The commonly used irradiation conditions of particularly preferable KrF excimer laser light and ArF excimer laser light are as follows.
KrF
Fluence: 100 mJ / cm ² / pulse or more 500 mJ / cm ² / pulse or less incident energy: 0.2 J / cm ² or more 2.0 J / cm ² or less number of shots: 1 to 20

ArF
Fluence: 50 mJ / cm ² / pulse or more 150 mJ / cm ² / pulse or less incident energy: 0.1 J / cm ² or more 1.0 J / cm ² or less number of shots: 1 to 20

  The content of the fluorine-containing resin particles is preferably 1% by mass to 20% by mass, and more preferably 1% by mass to 12% by mass, with respect to the total solid content of the protective layer (uppermost surface layer).

-Fluorine-containing dispersant-
The film constituting the protective layer (uppermost surface layer) may contain a fluorine-containing dispersant together with the fluorine-containing resin particles.
Since the fluorine-containing dispersant is used to disperse the fluorine-containing resin particles in the protective layer (the outermost surface layer), it preferably has a surface activity, that is, a hydrophilic group in the molecule It is preferably a substance having a hydrophobic group.

The fluorine-containing dispersant includes a resin obtained by polymerizing the following reactive monomer (hereinafter, referred to as "specific resin"). Specifically, a random or block copolymer of an acrylate having a perfluoroalkyl group and a monomer having no fluorine, a methacrylate homopolymer and an acrylate having the perfluoroalkyl group, and no fluorine A random or block copolymer of a monomer, and a random or block copolymer of a methacrylate and the monomer which does not have the said fluorine are mentioned. Examples of acrylates having a perfluoroalkyl group include 2,2,2-trifluoroethyl methacrylate and 2,2,3,3,3-pentafluoropropyl methacrylate.
Further, as a monomer having no fluorine, for example, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate , 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, 2-hydroxy acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methoxypolyethylene glycol acrylate, methoxy polyethylene glycol methacrylate , Phenoxy polyethylene glycol Le acrylate, phenoxy polyethylene glycol methacrylate, hydroxyethyl o- phenylphenol acrylate, o- phenylphenol glycidyl ether acrylate. Also, block or branch polymers disclosed in US Pat. No. 5,637,142, patent No. 425162, etc. can be mentioned. In addition, fluorine-based surfactants can be mentioned. Specific examples of the fluorine-based surfactant include Surfron S-611, Surfron S-385 (manufactured by AGC Seimi Chemical Co., Ltd.), FUTERgent 730 FL, FUTERgent 750 FL (manufactured by Neos), PF-636, PF-6520 (Kitamura) Manufactured by Kagaku Co., Ltd., Megafuck EXP, TF-1507, Megafuck EXP, TF-1535 (manufactured by DIC), FC-4430, FC-4432 (manufactured by 3M), and the like.
The weight average molecular weight of the specific resin is preferably 100 or more and 50000 or less.

  The content of the fluorine-containing dispersant is preferably 0.1% by mass or more and 1% by mass or less, and more preferably 0.2% by mass or more and 0.5% by mass or less based on the total solid content of the protective layer (the outermost surface layer). preferable.

  As a method of attaching the fluorine-containing dispersant to the surface of the fluorine-containing resin particles, the fluorine-containing dispersant may be directly attached to the surface of the fluorine-containing resin particles, After adsorption on the surface, polymerization may be performed to form the specific resin on the surface of the fluorine-containing resin particles.

  The fluorine-containing dispersant may be used in combination with other surfactants. However, the amount is preferably as small as possible, and the content of the other surfactant is preferably 0 parts by mass or more and 0.1 parts by mass or less, and preferably 0 parts by mass, with respect to 1 part by mass of the fluorine-containing resin particles. The content is 0.05 parts by mass or less, more preferably 0 parts by mass or more and 0.03 parts by mass or less.

Other surfactants include nonionic surfactants, such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl Esters, glycerin esters, fluorosurfactants and derivatives thereof can be mentioned.
Specific examples of polyoxyethylenes include, for example, Emulgen 707 (manufactured by Kao Corp.), Nalocacty CL-70, Nalocacty CL-85 (manufactured by Sanyo Chemical Industries, Ltd.), LeoCole TD-120 (manufactured by Lion Corp.), etc. Be

-Compound having unsaturated bond-
The film constituting the protective layer (uppermost surface layer) may be used in combination with a compound having an unsaturated bond.
The compound having an unsaturated bond may be any of a monomer, an oligomer and a polymer. Moreover, as a compound which has an unsaturated bond, the thing which does not have charge transportable frame | skeleton is mentioned.

Examples of the compound having an unsaturated bond which does not have a charge transporting skeleton include the following.
Monofunctional monomers are, for example, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, lauryl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl Acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, 2-hydroxy acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methoxy polyethylene glycol acrylate, methoxy polyethylene glycol methacrylate, phenoxy polyethylene glycol acrylate , Roh carboxymethyl polyethylene glycol methacrylate, hydroxyethyl o- phenylphenol acrylate, o- phenylphenol glycidyl ether acrylate, styrene, and the like.

Examples of difunctional monomers include diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, divinylbenzene, diallyl phthalate and the like can be mentioned.
Examples of trifunctional monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, aliphatic tri (meth) acrylate, trivinylcyclohexane and the like.
Examples of tetrafunctional monomers include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and aliphatic tetra (meth) acrylate.
Examples of the penta- or higher functional monomer include dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like, as well as (meth) acrylate having a polyester skeleton, a urethane skeleton, and a phosphazene skeleton.

  Further, among the compounds having unsaturated bonds, as polymers, for example, JP-A-5-216249, JP-A-5-323630, JP-A-11-52603, JP-A 2000-264961, The thing disclosed by Unexamined-Japanese-Patent No. 2005-2291 etc. is mentioned.

When using a compound having an unsaturated bond which does not have a charge transport component, it is used alone or as a mixture of two or more.
The content of the compound having an unsaturated bond having no charge transport component is, for example, preferably 60% by mass or less based on the total solid content of the composition used in forming the protective layer (uppermost surface layer). Preferably it is 55 mass% or less, More preferably, it is 50 mass% or less.

-Non-reactive charge transport material-
The film constituting the protective layer (uppermost surface layer) may be used in combination with a non-reactive charge transport material. Since the non-reactive charge transport material does not have a reactive group, the concentration of the charge transport component is increased when the non-reactive charge transport material is used for the protective layer (uppermost surface layer), and the electrical characteristics are improved. It is effective to further improve. Alternatively, a non-reactive charge transport material may be added to reduce the crosslink density and adjust the strength.

As the non-reactive charge transport material, known charge transport materials may be used. Specifically, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl substituted ethylene compounds, stilbene compounds Anthracene compounds, hydrazone compounds and the like are used.
Among them, those having a triphenylamine skeleton are preferable from the viewpoint of charge mobility, compatibility and the like.

  The non-reactive charge transport material is preferably used in an amount of 0% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 25% by mass or less based on the total solid content in the coating solution for layer formation. More preferably, they are 5 mass% or more and 25 mass% or less.

-Other additives-
The film constituting the protective layer (uppermost surface layer) is further mixed with other coupling agents, particularly with a fluorine-containing coupling agent, for the purpose of adjusting film forming property, flexibility, lubricity, adhesion and the like. You may use it. As such compounds, various silane coupling agents and commercially available silicone hard coat agents are used. Moreover, you may use the silicon compound which has a radically polymerizable group, and a fluorine-containing compound.

As a silane coupling agent, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxy Silane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, N-2 (aminoethyl) -3-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane , Dimethyldimethoxysilane, and the like.
Commercially available hard coating agents include KP-85, X-40-9740, X-8239 (above, Shin-Etsu Chemical Co., Ltd.), AY 42-440, AY 42-441, AY 49-208 (above, Toray Dow Corning Co., Ltd.) Etc.).

  In addition, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta), for imparting water repellency and the like. Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may also be added.

The silane coupling agent is used in any amount, but the amount of the fluorine-containing compound may be 0.25 times or less by mass with respect to the compound not containing fluorine from the viewpoint of the film formability of the crosslinked film. preferable. Furthermore, you may mix the reactive fluorine compound etc. which are disclosed by Unexamined-Japanese-Patent No. 2001-166510 etc. FIG.
Examples of the silicon compound having a radically polymerizable group and the fluorine-containing compound include compounds described in JP-A-2007-11005.

Conductive particles or organic or inorganic particles may be added to the film constituting the protective layer (uppermost surface layer).
As an example of this particle, silicon-containing particles can be mentioned. The silicon-containing particles are particles containing silicon as a constituent element, and specific examples thereof include colloidal silica and silicone particles. The colloidal silica used as the silicon-containing particles is preferably an acidic or alkaline aqueous dispersion or an organic solvent such as alcohol, ketone, ester or the like having an average particle diameter of 1 nm or more and 100 nm or less, more preferably 10 nm or more and 30 nm or less. It is selected from those dispersed in As the particles, those generally marketed may be used.

  The solid content of the colloidal silica in the protective layer is not particularly limited, but is 0.1% by mass or more and 50% by mass or less, preferably 0.1% by mass, based on the total solid content of the protective layer. It is used in% or more and 30 mass% or less.

The silicone particles used as the silicon-containing particles may be selected from silicone resin particles, silicone rubber particles, silicone surface-treated silica particles, and may be commercially available.
These silicone particles are spherical and preferably have an average particle size of 1 nm or more and 500 nm or less, more preferably 10 nm or more and 100 nm or less.
The content of silicone particles in the surface layer is preferably 0.1% by mass to 30% by mass, more preferably 0.5% by mass to 10% by mass, based on the total solid content of the protective layer. .

Further, as other particles, ZnO-Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ , In ₂ O ₃ -SnO ₂ , ZnO ₂ -TiO ₂ , ZnO-TiO ₂ , MgO-Al ₂ O ₃ , FeO _{-TiO 2, TiO 2, SnO 2} , in 2 O 3, ZnO, semiconductive metal oxides such as MgO and the like. In addition, various known dispersing agents may be used to disperse the particles.

An oil such as silicone oil may be added to the film constituting the protective layer (uppermost surface layer).
As silicone oils, silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, phenylmethylsiloxane, etc .; amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, mercapto-modified poly Reactive silicone oils such as siloxane and phenol modified polysiloxane; cyclic dimethyl cyclosiloxanes such as hexamethyl cyclotrisiloxane, octamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane and dodecamethyl cyclohexasiloxane; 1,3,5- Trimethyl-1.3.5-triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclo Cyclic methyl phenyl cyclosiloxanes such as trasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenyl cyclopentasiloxane; cyclic phenyl cyclosiloxanes such as hexaphenyl cyclotrisiloxane Fluorine-containing cyclosiloxanes such as 3- (3,3,3-trifluoropropyl) methyl cyclotrisiloxane; hydrosilyl group-containing cyclosiloxanes such as methylhydrosiloxane mixture, pentamethylcyclopentasiloxane, phenylhydrocyclosiloxane and the like And vinyl group-containing cyclosiloxanes such as pentavinyl pentamethyl cyclopentasiloxane.

  A silicone-containing oligomer, a fluorine-containing acrylic polymer, a silicone-containing polymer or the like may be added to the film constituting the protective layer (uppermost surface layer) in order to improve the wettability of the coating film.

Metals, metal oxides, carbon black and the like may be added to the film constituting the protective layer (uppermost surface layer). Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver and stainless steel, or those obtained by vapor-depositing these metals on the surface of resin particles. Examples of metal oxides include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, antimony oxide doped with antimony and tantalum and zirconium oxide doped with antimony, etc. .
These are used alone or in combination of two or more. When two or more kinds are used in combination, they may be simply mixed, or mixed in solid solution or fusion. The average particle diameter of the conductive particles is preferably 0.3 μm or less, and particularly preferably 0.1 μm or less.

-Composition-
The composition used to form the protective layer is preferably prepared as a coating solution for forming a protective layer, in which each component is dissolved or dispersed in a solvent.
Here, the solvent of the coating liquid for forming a protective layer is charge transport from the viewpoint of suppressing the solubility of the charge transport material, the dispersibility of the fluorine-containing resin particles, and the uneven distribution of the fluorine-containing resin particles on the surface side of the outermost surface layer. The difference (absolute value) of the SP value (solubility parameter calculated by the Feders method) with the binder resin (specific polycarbonate copolymer) of the layer is 2.0 or more and 4.0 or less (preferably 2.5 or more and 3.5 or less) The following ketone solvents or ester solvents may be used.
Specifically, as a solvent for the coating solution for forming a protective layer, for example, methyl ethyl ketone, methyl isobutyl ketone, diisopropyl ketone, diisobutyl ketone, ethyl n butyl ketone, di n propyl ketone, methyl n amyl ketone, methyl n butyl ketone, diethyl ketone, Ketones such as methyl n propyl ketone; isopropyl acetate, isobutyl acetate, ethyl acetate, n propyl acetate, n butyl acetate, ethyl isovalerate, isoamyl acetate, isopropyl butyrate, isoamyl propionate, butyl butyrate, amyl acetate, butyl propionate And solvents such as ethyl propionate, methyl acetate, methyl propionate, and esters such as allyl acetate, etc. may be used alone or in combination. And 0 to 50% by mass of ether solvents (eg, diethyl ether, dioxane, diisopropyl ether, cyclopentyl methyl ether, tetrahydrofuran etc.), alkylene glycol solvents (eg, 1-methoxy-2-propanol, 1-ethoxy-) 2-propanol, ethylene glycol monoisopropyl ether, propylene glycol monomethyl ether acetate, etc. may be mixed and used.

  As a dispersion method for dispersing the fluorine-containing resin particles in the coating solution for forming a protective layer, media dispersion machines such as ball mill, vibration ball mill, attritor, sand mill, horizontal sand mill, stirring, ultrasonic dispersion machine, roll mill, A dispersing method using a medialess dispersing machine such as a high pressure homogenizer may be mentioned. Furthermore, as the dispersion method, as a high-pressure homogenizer, a collision method in which the dispersion is dispersed by causing liquid-liquid collision or liquid-wall collision in a high pressure state to disperse, a penetration method in which a fine flow path is dispersed by The dispersion method is also mentioned.

  The method of preparing the coating solution for forming a protective layer is not particularly limited, and the charge transport material, the fluorine-containing resin particles, the fluorine-containing dispersant, and other components such as a solvent, if necessary, are mixed. It may be prepared using the above-mentioned disperser, or the two liquids of the mixed liquid A containing fluorine-containing resin particles, the fluorine-containing dispersant and the solvent, and the mixed liquid B containing at least the charge transport material and the solvent separately. After preparation, it may be prepared by mixing the mixed solution A and the mixed solution B. By mixing the fluorine-containing resin particles and the fluorine-containing dispersant in the solvent, the fluorine-containing dispersant is easily attached to the surface of the fluorine-containing resin particles.

  When the above components are reacted to obtain a coating solution for forming a protective layer, each component may be simply mixed and dissolved, but preferably from room temperature (20 ° C.) to 100 ° C., more preferably 30 ° C. The heating is performed at a temperature of 80 ° C. or less, preferably 10 minutes to 100 hours, more preferably 1 hour to 50 hours. In addition, it is also preferable to irradiate ultrasonic waves at this time.

-Formation of protective layer-
The coating solution for forming a protective layer is formed by blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, curtain coating, or the like on the surface to be coated (charge transport layer). It is applied by a usual method such as an ink jet coating method.
Thereafter, light, an electron beam or heat is applied to the obtained coating film to cause radical polymerization to cure the coating film.

  As a method of curing, heat, light, radiation or the like is used. When curing is performed by heat or light, a polymerization initiator is not necessarily required, but a photocuring catalyst or a thermal polymerization initiator may be used. As the photocuring catalyst and the thermal polymerization initiator, known photocuring catalysts and thermal polymerization initiators are used. As radiation, an electron beam is preferable.

Electron Beam Curing When using an electron beam, the acceleration voltage is preferably 300 KV or less, and most preferably 150 KV or less. The dose is preferably in the range of 1 Mrad to 100 Mrad, more preferably in the range of 3 Mrad to 50 Mrad. When the acceleration voltage is 300 KV or less, the damage of the electron beam irradiation to the photosensitive member characteristics is suppressed. Further, when the dose is 1 Mrad or more, crosslinking is sufficiently performed, and when the dose is 100 Mrad or less, deterioration of the photosensitive member is suppressed.

  The irradiation may be performed at an oxygen concentration of 1000 ppm, preferably 500 ppm or less, in an inert gas atmosphere such as nitrogen or argon, and may be heated to 50 ° C. to 150 ° C. during or after irradiation.

-Photo-curing As a light source, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, etc. are used, and a suitable wavelength may be selected using a filter such as a band pass filter. Irradiation time, the light intensity is selected freely, for example, the illuminance (365 nm) is 300 mW / cm ² or more, preferably 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 600 mW / cm ^2, 5 seconds or more 360 It may be irradiated for less than a second.

  The irradiation may be performed at an oxygen concentration of preferably 1000 ppm or less, more preferably 500 ppm or less, in an inert gas atmosphere such as nitrogen or argon, and may be heated to 50 ° C. to 150 ° C. during or after irradiation.

As the photocuring catalyst, as the intramolecular cleavage type, benzyl ketal type, alkylphenone type, aminoalkylphenone type, phosphine oxide type, titanocene type, oxime type and the like can be mentioned.
More specifically, examples of benzyl ketal include 2,2-dimethoxy-1,2-diphenylethan-1-one.

In addition, as an alkyl phenone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] 2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl- Propan-1-one, acetophenone, 2-phenyl-2- (p-toluenesulfonyloxy) acetophenone can be mentioned.
As an amino alkyl phenone type, p-dimethylamino acetophenone, p-dimethylamino propiophenone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1 -Butanone etc. are mentioned.
Examples of phosphinoxides include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphincide and the like.
Examples of titanocenes include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium and the like.
As an oxime system, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl]-, 1- (O-acetyloxime) and the like.

As a hydrogen abstraction type, benzophenone type, thioxanthone type, benzyl type, Michler's ketone type etc. are mentioned.
More specifically, as benzophenones, 2-benzoylbenzoic acid, 2-chlorobenzophenone, 4,4'-dichlorobenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, p, p'-bisdiethylaminobenzophenone and the like It can be mentioned.
As a thioxanthone type | system | group, a 2, 4- diethyl thioxanthen 9-one, 2-chloro thioxanthone, 2-isopropyl thioxanthone etc. are mentioned.
Examples of benzyl include benzyl, (±) -camphor quinone, p-anisyl and the like.

  These photopolymerization initiators may be used alone or in combination of two or more.

Thermosetting Thermal polymerization initiators include a thermal radical generator or a derivative thereof. Specifically, for example, V-30, V-40, V-59, V601, V65, V-70, VF- Azo initiators such as 096, VE-073, Vam-110, Vam-111 (manufactured by Wako Pure Chemical Industries, Ltd.), OTazo-15, OTazo-30, AIBN, AMBN, ADVN, ACVA (Otsuka Chemical Co., Ltd.); Perhexa HC, Per Hex C, Per Hex V 22, Per Hex MC, Per Butyl H, Percumyl H, Percumyl P, Permenta H, Per Octal H, Per Butyl C, Per Butyl D, Perhexyl D, Peroyl IB, Peroyl 355, Peroyl L, Peroyl SA , Nyper BW, nyper BMT-K 40 / M, peroyl IPP, perlo IL NPP, Peroyl TCP, Peroyl OPP, Perroyl SBP, Perkyl ND, Perocta ND, Perhexyl ND, Perbutyl ND, Perbutyl NHP, Perhexyl PV, Perbutyl PV, Perhexa 250, Perocta O, Perhexyl O, Perbutyl O, Perbutyl L, Perbutyl 355 , Perhexyl I, Perbutyl I, Perbutyl E, Perhexa 25Z, Perbutyl A, Perhexyl Z, Perbutyl ZT, Perbutyl Z (manufactured by NOF Chemical Co., Ltd.), Kayaketal AM-C55, Trigonox 36-C75, Laurox, Percadox L-W75, Perka Dox CH-50 L, Trigonox TM BH, Kayakmen H, Kayabutyl H-70, Percadox BC-FF, Kaya Hexa AD, Perka Dox 14, Kayabuti C, Kayabutyl D, Kaya Hexa YD-E85, Percadox 12-XL25, Percadox 12-EB20, Trigonox 22-N70, Trigonox 22-70 E, Trigonox D-T50, Trigonox 423-C70, Kaya Ester CND-C70, Kaya Ester CND-W50, Trigonox 23-C70, Trigonox 23-W50N, Trigonox 257-C70, Kayaester P-70, Kayaester TMPO-70, Trigonox 121, Kayaester O, Kayaester HTP-65W, Kayaester AN, Trigonox 42 Trigonox F-C50, Kaya butyl B, Kaya carbon EH-C70, Kaya carbon EH-W60, Kaya carbon I-20, Kaya carbon BIC-75, trigonock 117, Kayalen 6-70 (manufactured by Kayaku Akzo Co., Ltd.), Luperox 610, Luperox 188, Luperox 844, Luperox 259, Luperox 10, Luperox 701, Luperox 11, Luperox 26, Luperox 80, Luperox 7, Luperox 270, Luperox P, Ruperox 546, Ruperox 554, Ruperox 575, Ruperox 555, Ruperox 570, Luperox TAP, Luperox TBIC, Ruperox TBEC, Ruperox JW, Ruperox TAIC, Ruperox TAEC, Ruperox DC, Ruperox 101, Ruperox F, Ruperox DI, Ruperox 130 , Luperox 220, Luperox 230, Luperox 23 3 and Luperox 531 (manufactured by Arkema Yoshitomi Co., Ltd.).

  Among these, when an azo polymerization initiator having a molecular weight of 250 or more is used, the reaction proceeds uniformly at a low temperature, so that formation of a high-strength film in which unevenness is suppressed can be achieved. More preferably, the molecular weight of the azo polymerization initiator is 250 or more, and 300 or more is more preferable.

  The heating is performed in an inert gas atmosphere such as nitrogen or argon at an oxygen concentration of preferably 1000 ppm or less, more preferably 500 ppm or less, preferably 50 ° C. to 170 ° C., more preferably 70 ° C. to 150 ° C., Preferably, heating is performed for 10 minutes or more and 120 minutes or less, more preferably 15 minutes or more and 100 minutes or less.

  The total content of the photocuring catalyst or the thermal polymerization initiator is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.1% by mass or more, with respect to the total solid content in the solution for layer formation. 8 mass% or less is more preferable, and the range of 0.1 mass% or more and 5 mass% or less is especially preferable.

In the present embodiment, if the reaction proceeds too fast, the structural relaxation of the coating film becomes difficult due to crosslinking, and the generation of radicals relatively slowly occurs because the film becomes uneven and wrinkled easily. Curing method is adopted.
In particular, by combining a specific chain-polymerizable charge transporting material and curing by heat, structural relaxation of the coating film is promoted, and a high protective layer (uppermost surface layer) having excellent surface properties is easily obtained.

  The film thickness of the protective layer is, for example, preferably in the range of 3 μm to 40 μm, more preferably 5 μm to 35 μm, and still more preferably 7 μm to 30 μm.

  The configuration of each layer in the function separation type photosensitive layer has been described above with reference to the electrophotographic photosensitive member shown in FIG. 1, but this configuration is also applied to each layer in the function separated type electrophotographic photosensitive member shown in FIG. It can be adopted. Further, in the case of the single-layer type photosensitive layer of the electrophotographic photosensitive member shown in FIG.

That is, the single-layer type photosensitive layer (charge generation / charge transport layer) is configured to include a charge generation material, a charge transport material, and, if necessary, a binder resin and other known additives. Is good. Note that these materials are the same as the materials described for the charge generation material and the charge transport layer.
The content of the charge generation material in the single-layer type photosensitive layer is preferably 10% by mass to 85% by mass, and more preferably 20% by mass to 50% by mass, with respect to the total solid content. Further, the content of the charge transport material in the single-layer type photosensitive layer is preferably 5% by mass to 50% by mass with respect to the total solid content.
The method of forming the single-layer type photosensitive layer is the same as the method of forming the charge generation layer or the charge transport layer.
The film thickness of the single layer type photosensitive layer is, for example, 5 μm to 50 μm, and preferably 10 μm to 40 μm.

In the electrophotographic photosensitive member according to the present embodiment, the form in which the outermost surface layer is a protective layer has been described, but a layer configuration without a protective layer may be employed.
In the case of a layer configuration without a protective layer, in the electrophotographic photosensitive member shown in FIG. 1, the charge transport layer located on the outermost surface in the layer configuration is the outermost surface layer. And the charge transport layer which becomes the said outermost layer is comprised by the cured film of the said specific composition.
In the case of a layer configuration without a protective layer, in the electrophotographic photosensitive member shown in FIG. 3, the single-layer type photosensitive layer located on the outermost surface in the layer configuration is the outermost surface layer. And the single layer type photosensitive layer used as the said outermost layer is comprised by the cured film of the said specific composition. However, a charge generating material is blended in the above composition.

-Charging device-
As the charging device 8, a charging device which is disposed in contact with or in proximity to the surface of the electrophotographic photosensitive member 7 and which charges the surface of the electrophotographic photosensitive member is employed. Here, to arrange the charging device 8 in proximity, for example, the charging device 8 (its conductive member (charging member)) is arranged to be separated from the surface of the electrophotographic photosensitive member 7 in the range of 1 μm to 200 μm. Indicates that.
Specifically, as the charging device 8, a contact type charging device provided with a conductive or semiconductive member such as a charging roller, a charging brush, a charging film, a charging rubber blade, or a charging tube in contact with the surface of the electrophotographic photosensitive member 7. And a proximity type charging device in which the conductive or semiconductive member is provided apart from the surface of the electrophotographic photosensitive member 7.

-Exposure apparatus-
Examples of the exposure device 9 include an optical system device that exposes the surface of the electrophotographic photosensitive member 7 with light such as semiconductor laser light, LED light, liquid crystal shutter light, etc. in a defined image. The wavelength of the light source is in the spectral sensitivity region of the electrophotographic photosensitive member. As the wavelength of the semiconductor laser, near infrared light having an oscillation wavelength around 780 nm is the mainstream. However, the wavelength is not limited to this, and a laser having an oscillation wavelength of 400 nm or more and 450 nm or less may be used as an oscillation wavelength laser of about 600 nm or a blue laser. In addition, a surface emitting laser light source of a type capable of outputting multiple beams is also effective for color image formation.

-Development device-
Examples of the developing device 11 include, for example, a general developing device which develops with a developer in contact or non-contact. The developing device 11 is not particularly limited as long as it has the above-described function, and is selected according to the purpose. For example, a known developing device or the like having a function of causing the one-component developer or the two-component developer to adhere to the electrophotographic photosensitive member 7 using a brush, a roller or the like can be mentioned. Among them, one using a developing roller holding a developer on the surface is preferable.

  Here, the developer contained in the developing device contains toner particles and fatty acid metal salt particles. The fatty acid metal salt particles are included in the developer as an external additive.

Next, the configuration of the toner particles will be described.
The toner particles contain, for example, a binder resin. The toner particles may optionally contain a colorant, a release agent and other additives.

Binder resin As the binder resin, for example, styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.), (meth) acrylates (eg, methyl acrylate, ethyl acrylate, acrylic acid n-) Propyl, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc., ethylenically unsaturated nitriles (Eg acrylonitrile, methacrylonitrile etc.), vinyl ethers (eg vinyl methyl ether, vinyl isobutyl ether etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone etc.), olefins (eg ethylene) , Propylene, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, non-vinyl resin such as modified rosin, a mixture of these with the above-mentioned vinyl resin, or The graft polymer etc. which are obtained by polymerizing a vinyl-type monomer in coexistence are also mentioned.
These binder resins may be used alone or in combination of two or more.

  The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less More preferable.

-Colorant As a colorant, for example, carbon black, chrome yellow, Hansa yellow, benzidine yellow, Sureren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, Vulcan orange, watch young red, permanent red, brilliant carmine 3B, Brilliant Carmine 6B, DuPont Oil Red, Pyrazolone Red, Risol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Chalco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Various pigments such as phthalocyanine green, malachite green oxalate, or acridine type, xanthe Types, azo type, benzoquinone type, azine type, anthraquinone type, anthraquinone type, thioindico type, dioxazine type, thiazine type, azomethine type, indico type, phthalocyanine type, aniline black type, polymethine type, triphenylmethane type, diphenylmethane type, thiazole type And various dyes and the like.
The coloring agents may be used alone or in combination of two or more.

  As the coloring agent, a surface-treated coloring agent may be used if necessary, and may be used in combination with a dispersing agent. Moreover, a coloring agent may use multiple types together.

  As content of a coloring agent, 1 mass% or more and 30 mass% or less are preferable with respect to the whole toner particle, for example, and 3 mass% or more and 15 mass% or less are more preferable.

· Releasing agent As the releasing agent, for example, hydrocarbon wax; natural wax such as carnauba wax, rice wax, candelilla wax; synthesis of montan wax etc. or mineral or petroleum wax; fatty acid ester, montanic acid ester etc. Ester-based waxes; and the like. The release agent is not limited to this.

50 degreeC or more and 110 degrees C or less are preferable, and, as for the melting temperature of a mold release agent, 60 degrees C or more and 100 degrees C or less are more preferable.
In addition, melting temperature is calculated | required by "melting peak temperature" as described in how to obtain | require the melting temperature of JISK-1987 "the transition temperature measurement method of plastics" from the DSC curve obtained by differential scanning calorimetry (DSC).

  The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

Other Additives Other additives include, for example, known additives such as magnetic substances, charge control agents and inorganic powders. These additives are contained in the toner particles as an internal additive.

· Properties of toner particles, etc. The toner particles may be toner particles having a single layer structure, and a so-called core / shell formed of a core (core particles) and a coating layer (shell layer) for coating the core. It may be a toner particle of structure.
Here, the toner particles having a core-shell structure include, for example, a core portion constituted by including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised by the comprised coating layer.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm to 10 μm, and more preferably 4 μm to 8 μm.

In addition, various average particle diameters of toner particles and various particle size distribution indexes are measured using Coulter Multisizer II (manufactured by Beckman Coulter Co., Ltd.), and electrolytic solution is measured using ISOTON-II (manufactured by Beckman Coulter Co.) Ru.
In the measurement, 0.5 mg or more and 50 mg or less of a measurement sample is added to 2 ml of a 5% aqueous solution of surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of electrolyte solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and Coulter Multisizer II, using an aperture of 100 μm as the aperture diameter, the particle size distribution of particles of 2 μm to 60 μm in size. taking measurement. The number of particles to be sampled is 50,000.
With respect to the particle size range (channel) divided based on the particle size distribution to be measured, the cumulative distribution is drawn from the small diameter side in terms of volume and number, and the particle size of cumulative 16% is the volume particle size D16v, number particle size The particle diameter of D16p and cumulative 50% is defined as volume average particle diameter D50v, cumulative number average particle diameter D50p, and particle diameter of 84% cumulative, as volume particle diameter D84v and number particle diameter D84p.
Using these, the volume average particle size distribution index (GSDv) is calculated as (D84 v / D 16 v) ^1/2 , and the number average particle size distribution index (GSD p) is calculated as (D 84 p / D 16 p) ^1/2 .

  The shape factor SF1 of the toner particles is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

The shape factor SF1 is determined by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above equation, ML represents the absolute maximum length of the toner, and A represents the projected area of the toner.
Specifically, the shape factor SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, an optical microscope image of particles dispersed on the slide glass surface is taken into a Luzex image analyzer by a video camera, the maximum length and projection area of 100 particles are determined, and calculation is made according to the above equation, and the average value is determined. can get.

External Additive The external additive contains fatty acid metal salt particles. The external additive may contain, in addition to the fatty acid metal salt particles, other external additives such as inorganic abrasive particles and inorganic lubricant particles from the viewpoint of suppressing unevenness in image density.

Examples of fatty acid metal salt particles include fatty acids (eg, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, lauric acid, and other fatty acids such as organic acids) and metals (eg, calcium, zinc, magnesium, aluminum, etc.) Particles of metal salts with other metals (Na, Li etc.) can be mentioned.
Specific examples of fatty acid metal salt particles include zinc stearate, calcium stearate, iron stearate, copper stearate, magnesium palmitate, calcium palmitate, manganese oleate, lead oleate, zinc laurate, zinc palmitate And the like.
Among these, fatty acid metal salt particles are preferably particles of zinc stearate from the viewpoint of suppressing unevenness in image density as well as lubricity, hydrophobicity, and wettability to an electrophotographic photosensitive member.

  The fatty acid metal salt particles may be mixed particles of a plurality of fatty acid metal salts. The fatty acid metal salt particles may also be particles containing a fatty acid metal salt and other components. Examples of other components include higher fatty acid alcohols. However, fatty acid metal salt particles contain 10% by mass or more of fatty acid metal salt.

The median diameter based on the volume of fatty acid metal salt particles is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.2 μm or more and 10.0 μm or less, and more preferably 0.2 μm or more and 0.2 μm or less from the viewpoint of suppressing density unevenness of an image. 0 μm or less is more preferable.
The median diameter based on the volume of fatty acid metal salt particles is a value measured by the following method. As a measuring apparatus, a laser diffraction / scattering type particle size distribution measuring apparatus "LA-920" (manufactured by Horiba, Ltd.) is used. Setting of measurement conditions and analysis of measurement data use dedicated software “HORIBA LA-920 for Windows (registered trademark) WET (LA-920) Ver. 2.02” attached to LA-920. In addition, ion exchange water from which impure solid substances and the like have been removed in advance is used as a measurement solvent.

The inorganic abrasive particles are inorganic particles having a function of polishing the surface of the photosensitive member.
Inorganic abrasive particles include particles of well-known abrasives such as inorganic oxides, nitrides, borides, carbonates and the like. Specific examples of inorganic abrasive particles include, for example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide And particles of tin oxide, tellurium oxide, manganese oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride, calcium carbonate, magnesium carbonate, hydrotalcite and the like.
Among these, as the inorganic abrasive particles, at least one selected from the group consisting of particles of cerium oxide and particles of strontium titanate from the viewpoint of suppressing unevenness in image density as well as abrasiveness, availability, and cost. Preferred are particles of the species (in particular, stringium titanate).

In the inorganic abrasive particles, the surface may be subjected to a hydrophobization treatment with a hydrophobization treatment agent.
Examples of the hydrophobizing agent include titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecyl benzene sulfonyl titanate, and bis (dioctyl pyrophosphate) oxyacetate titanate; 2-Aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, N-2- (N-vinylbenzylaminoethyl) 3-aminopropyl Trimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrichloride Silane coupling agents such as toxilsilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, etc .; silicone oils; aluminum stearate, zinc stearate, And higher fatty acid metal salts such as calcium stearate; and the like. These may be used alone or in combination of two or more.
The amount of the hydrophobic treatment agent is usually, for example, 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the inorganic particles.

The median diameter based on the volume of the inorganic abrasive particles is preferably 0.1 μm or more and 10.0 μm or less, more preferably 1.0 μm or more and 10.0 μm or less, and more preferably 2.0 μm or more, from the viewpoint of suppressing density unevenness of the image. 0 μm or less is more preferable.
The median diameter based on the volume of the inorganic abrasive particles is a value measured similarly to the median diameter of the fatty acid metal salt particles.

The inorganic lubricant particles include particles having a function of cleaving and lubricating the substance itself or particles which cause internal slippage. Specific examples of the inorganic lubricant particles include mica, boron nitride, molybdenum disulfide, tungsten disulfide, talc, talc, kaolinite, montmorillonite, calcium fluoride, graphite and the like.
Among these, as inorganic lubricant particles, particles of boron nitride are preferable from the viewpoint of suppressing unevenness in image density as well as lubricity.

The volume average particle diameter of the inorganic lubricant particles is preferably 0.1 μm or more and 10 μm or less, more preferably 0.2 μm or more and 10 μm or less, and still more preferably 0.2 μm or more and 8 μm or less from the viewpoint of suppressing density unevenness of an image.
The volume average particle diameter of the inorganic lubricant particles is determined by observing 100 primary particles of the inorganic lubricant particles with a scanning electron microscope (SEM) device, and measuring 50 as the cumulative frequency of the equivalent circle diameter obtained by image analysis of the primary particles. % Diameter (D50v), measured by this method.

Examples of other external additives include inorganic particles having a volume average particle size of 5 nm or more and less than 100 nm (preferably 5 nm or more and 80 nm or less). The inorganic particles are externally added to toner particles for the purpose of improving toner fluidity and chargeability. The volume average particle size of the inorganic particles is a value measured by the same method as the volume average particle size of the inorganic lubricant particles.
Examples of the inorganic particles include SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, and ZrO _{2. , CaO · SiO 2, K 2} O · (TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.
The surface of the inorganic particles may be subjected to a hydrophobization treatment. The hydrophobization treatment is performed, for example, by immersing inorganic particles in a hydrophobization treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used alone or in combination of two or more.
The amount of the hydrophobic treatment agent is usually, for example, 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the inorganic particles.

  Other external additives include resin particles (resin particles such as polystyrene, PMMA, melamine resin, etc.), cleaning activators (for example, particles of fluorine-based high molecular weight), and the like.

  Other external additives also include particles of fatty acid metal salt and particles of lubricant other than inorganic lubricant particles. As particles of lubricants, low molecular weight polyolefins such as polypropylene, polyethylene and polybutene; silicones having a softening point by heating, aliphatics such as oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide and the like Amides; plant-based waxes such as carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil; animal-based waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Examples of such particles include mineral or petroleum waxes; and modified products thereof.

Method of Manufacturing Toner Next, a method of manufacturing the toner according to the present embodiment will be described.
The toner according to the exemplary embodiment is obtained by externally adding an external additive to toner particles after producing the toner particles.

  The toner particles may be produced by any of dry production method (for example, kneading and pulverization method and the like) and wet production method (for example, aggregation and coalescence method, suspension polymerization method, dissolution and suspension method and the like). There are no particular limitations on the method for producing toner particles, and any known method may be employed.

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to the obtained toner particles in a dry state and mixing them. The mixing may be performed by, for example, a V blender, a Henschel mixer, a Loedige mixer, or the like. Furthermore, if necessary, coarse particles of toner may be removed using a vibration divider, an air flow divider, or the like.

Carrier The carrier is not particularly limited, and may be any known carrier. As the carrier, for example, a coated carrier obtained by coating a coating resin on the surface of a core material made of magnetic powder; a magnetic powder dispersion type carrier in which magnetic powder is dispersed / blended in a matrix resin; porous magnetic powder is impregnated with resin Resin impregnated carriers; and the like.
The magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier in which the constituent particles of the carrier are used as a core material and the core particles are coated with a coating resin.

  The mixing ratio (mass ratio) of toner and carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

-Cleaning device-
As the cleaning device 13, a cleaning blade type device provided with a cleaning blade 131 is used.

  The cleaning blade 131 has a first portion in contact with the surface of the electrophotographic photosensitive member 7 and other first portions from the viewpoint of improving wear resistance, sag resistance (permanent deformation resistance), and chipping resistance. It is preferable to have two parts, and the material of the first layer satisfies the following formulas (1) to (3).

-Formula (1) 3.92 <= M <= 29.42
Formula (2) 0 <α ≦ 0.294
· Formula (3) S 250 250
[Wherein, in the formulas (1) to (3), M represents 100% modulus (MPa), α represents a strain amount change (Δ strain amount at a strain amount of 100% or more and 200% or less) Ratio of stress change (Δ stress) to Δ) {Δ stress / Δ strain amount = (stress at 200% strain−stress at 100% strain amount) / (200−100)} (MPa /%), S represents The breaking elongation (%) measured based on JIS K6251 (use of dumbbell-shaped No. 3 test piece) is shown. ]

The 100% modulus M shown in the formula (1) can be obtained from the stress at 100% strain, measured at a tensile speed of 500 mm / min using a dumbbell-shaped No. 3 test piece in accordance with JIS K6251 (1993). . In addition, as a measuring apparatus, a Toyo Seiki Co., Ltd. product and Strograph AE elastomer were used.
On the other hand, α shown in the equation (2) is obtained from a stress-strain curve. The amount of stress and strain can be determined by the procedure and method described below. That is, in accordance with JIS K6251 (1993), using a dumbbell-shaped No. 3 test piece, it is measured at a tensile speed of 500 mm / min, and is obtained from stress at 100% strain and stress at 200% strain. In addition, as a measuring apparatus, a Toyo Seiki Co., Ltd. product and Strograph AE elastomer were used.

  Here, the cleaning blade 131 includes: 1) a first layer (an example of a first portion) in contact with the surface of the electrophotographic photosensitive member 7 and a second layer (an example of a second portion) on the back surface of the first layer 2) a contact portion (an example of a first portion) disposed at a corner of the blade contacting the surface of the electrophotographic photosensitive member 7 and a support portion (an example of a second portion) supporting the contact portion And the structure which has and. The second layer as the back layer may have a single layer structure or a multilayer structure of two or more layers.

  Hereinafter, the cleaning blade 131 having a two-layer configuration including the first layer and the second layer (single layer) as the back layer will be described in detail.

First Layer When the material of the first layer satisfies the formula (1), abrasion resistance tends to be enhanced while exhibiting good cleaning properties. The 100% modulus M is preferably in the range of 5 MPa to 20 MPa, and more preferably in the range of 6.5 MPa to 15 MPa.

When the material of the first layer satisfies the formulas (2) and (3), chipping resistance tends to be enhanced.
Here, α is preferably 0.2 or less, more preferably 0.1 or less, and the closer to 0, which is the limit lower limit value in physical properties, the better.
The breaking elongation S is preferably 300% or more, more preferably 350% or more. On the other hand, the breaking elongation S is preferably 500% or less, more preferably 450% or less, and still more preferably 400% or less from the viewpoint of wear resistance.

  From the viewpoint of the stability of the contact pressure of the cleaning blade 131, the glass transition temperature Tg of the material of the first layer is preferably equal to or lower than the lower limit (for example, 10 ° C.) of the operating environment temperature of the apparatus.

The glass transition temperature of the material of the first layer is determined as a peak temperature of tan δ (loss tangent) by measuring temperature dispersion with a viscoelasticity measuring device.
Here, the tan δ value is derived from the storage and loss modulus described below. When a linear elastic body is given a sinusoidal distortion in a steady-state vibration manner, the stress is expressed by equation (4). | E * | is called complex elastic modulus. Further, according to the theory of rheology, the elastic component is represented by the formula (5), and the viscous component is represented by the formula (6). Here, E ′ is called storage modulus, and E ′ ′ is called loss modulus. δ represents the phase difference angle between stress and strain, and is called “mechanical loss angle”.
The tan δ value is expressed by E ′ ′ / E ′ as in equation (7) and is called “loss sine”, and the larger the value, the more the linear elastic body has rubber elasticity. .
Equation (4) σ = | E * | γ cos (ωt)
Formula (5) E '= | E * | cos δ
Equation (6) E ′ ′ = | E * | sin δ
Formula (7) tan δ = E ′ ′ / E ′
The tan δ value was measured at a static strain of 5%, 10 Hz sine wave tensile excitation in a temperature range of −60 ° C. or more and 100 ° C. or less by Leopectra-DVE-V4 (manufactured by Rheology Co., Ltd.).

  The impact resilience R of the material of the first layer is preferably 10% or more, preferably 15% or more, under an environment at a temperature of 10 ° C. or higher, which is a substantially lower limit value of the operating environment temperature. Preferably, 20% or more is more preferable. Stick-and-slip behavior (microscopic self-excitation vibration phenomenon caused by repeated adhesion and sliding of the first layer to the surface of the electrophotographic photoreceptor 7) when the impact resilience R of the material of the first layer is 10% or more Is more likely to occur, and plastic deformation of the first layer is less likely to occur. Thereby, the adhesion between the first layer and the electrophotographic photosensitive member 7 is improved, and the occurrence of the cleaning failure is easily suppressed. The impact resilience R is a value measured according to JIS K 6255 (1996).

Next, materials satisfying the formulas (1) to (3) will be described.
Although the material which satisfy | fills Formula (1)-(3) will not be specifically limited if it is an elastomeric material, It is especially preferable that it is an elastomeric material containing a hard segment and a soft segment. By including both the hard segment and the soft segment, the elastomeric material can easily satisfy the physical properties shown in Formulas (1) to (3), and both wear resistance and chipping resistance can be achieved at a higher level. It is because it can be compatible.
In the “hard segment” and “soft segment”, in the elastomer material, the material constituting the former is relatively harder than the material constituting the latter, and the material constituting the latter is Means a segment made of a material softer than the material constituting the former.

Here, the glass transition temperature of the elastomeric material containing the hard segment and the soft segment is preferably in the range of −50 ° C. to 30 ° C., and more preferably in the range of −30 ° C. to 10 ° C. When the glass transition temperature is 30 ° C. or less, the occurrence of embrittlement tends to be suppressed in the practical temperature range in which the cleaning blade is used. In addition, when the glass transition temperature is -50 ° C or more, sufficient hardness and stress can be easily obtained in the practical use region.
Therefore, in order to realize the glass transition temperature in the above range, the glass transition temperature of the material constituting the hard segment of the elastomer material (hereinafter sometimes referred to as “hard segment material”) is 30 ° C. or more and 100 ° C. or less It is preferable to be in the range of 35.degree. C. to 60.degree. C. or less. On the other hand, the glass transition temperature of the material constituting the soft segment (hereinafter sometimes referred to as “soft segment material”) is preferably in the range of −100 ° C. or more and −50 ° C. or less, −90 ° C. or more It is more preferable to be in the range of 60 ° C. or less.

In addition, when hard segment material and soft segment material having a glass transition temperature in the above range are used, the mass ratio of the material constituting the hard segment to the total amount of hard segment material and soft segment material (hereinafter referred to as “hard segment material ratio” Is preferably in the range of 46% by mass to 96% by mass, more preferably in the range of 50% by mass to 90% by mass, and more preferably 60% by mass to 85% by mass More preferably, it is within the range.
When the hard segment material ratio is 46% by mass or more, the wear resistance of the front end of the first layer is ensured, and the occurrence of wear is easily suppressed. This makes it easy to maintain good cleanability over a long period of time. In addition, when the hard segment material ratio is 96 mass% or less, the tip of the first layer does not become too hard, and flexibility and extensibility are easily obtained. As a result, the occurrence of chipping can be suppressed, and good cleanability can be easily maintained over a long period of time.

The combination of hard segment material and soft segment material is not particularly limited, and is selected from known resin materials such that one is relatively hard with respect to the other and the other is relatively soft with respect to the one. However, the following combinations are preferred.
That is, it is preferable to use a polyurethane resin as the hard segment material. The weight average molecular weight of the polyurethane resin in this case is preferably in the range of 1000 or more and 4000 or less, and more preferably in the range of 1500 or more and 3500 or less.
When the weight average molecular weight is 1000 or more, when the cleaning blade 131 is used in a low temperature environment, the elasticity of the polyurethane resin constituting the hard segment is unlikely to be lost. This makes it easy to suppress cleaning failure. In addition, when the weight average molecular weight is 4000 or less, the permanent deformation of the polyurethane resin constituting the hard segment is unlikely to be excessively large. As a result, since the front end of the first layer can hold the contact pressure with respect to the electrophotographic photosensitive member 7, the cleaning failure is easily suppressed.
Examples of the polyurethane resin used as the hard segment material include Plaxel 205 and Plaxel 240, etc., manufactured by Daicel Chemical Industries, Ltd.

  The pressing pressure of the cleaning blade 131 is preferably set to 1.7 gf / mm or more and 6.5 gf / mm or less, more preferably 2.0 gf / mm or more and 6.0 gf / mm or less. When the pressing pressure is equal to or more than the lower limit value, cleaning failure of the toner can be easily suppressed even when using a high hardness blade. If the pressing pressure is less than the above upper limit, the friction with the photosensitive member does not become too high, and the torque increase, the photosensitive member wear, the generation of streaks due to blade edge chipping, and the generation of ghost due to the frictional contact with the photosensitive member are suppressed. It becomes easy to do.

-Transfer device-
The transfer device 40 may be, for example, a contact type transfer charger using a belt, a roller, a film, a rubber blade or the like, a scorotron transfer charger using corona discharge, a corotron transfer charger, etc. It can be mentioned.

-Intermediate transfer body-
As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) containing semiconductive conductive polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber and the like is used. The intermediate transfer member may be in the form of a drum other than the belt.

FIG. 5 is a schematic configuration view showing another example of the image forming apparatus according to the present embodiment.
An image forming apparatus 120 shown in FIG. 5 is a tandem multicolor image forming apparatus in which four process cartridges 300 are mounted. In the image forming apparatus 120, four process cartridges 300 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member is used for one color. The image forming apparatus 120 has the same configuration as that of the image forming apparatus 100 except that the image forming apparatus 120 is a tandem system.

  Note that the image forming apparatus (process cartridge) according to the present embodiment described above is not limited to the above configuration, and a known configuration may be applied.

  EXAMPLES The present invention will be described more specifically by the following examples, but the present invention is not limited thereto.

<Production of Photoreceptor>
[Photosensitive body (1)]
-Preparation of undercoat layer-
Zinc oxide: (average particle diameter 70 nm: manufactured by Tayca: specific surface area 15 m ² / g) 100 parts by mass is stirred and mixed with 500 parts by mass of toluene, and a silane coupling agent (KBM 503: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.3 The parts were added and stirred for 2 hours. Thereafter, toluene was distilled off by distillation under reduced pressure, and baking was carried out at 120 ° C. for 3 hours to obtain a silane coupling agent surface-treated zinc oxide.
110 parts by mass of surface-treated zinc oxide was stirred and mixed with 500 parts by mass of tetrahydrofuran, and a solution of 0.6 parts by mass of alizarin dissolved in 50 parts by mass of tetrahydrofuran was added and stirred at 50 ° C. for 5 hours . Thereafter, the zinc oxide to which alizarin was imparted was separated by filtration under reduced pressure, and further dried under reduced pressure at 60 ° C. to obtain alizarin-added zinc oxide.

60 parts by mass of this alizarin-imparted zinc oxide and a curing agent (blocked isocyanate semidur 3175, manufactured by Sumitomo Bavaria Urethane Co., Ltd.): 13.5 parts by mass and 15 parts by mass of butyral resin (S-Lec BM-1, manufactured by Sekisui Chemical Co., Ltd.) A solution of 38 parts by mass of methyl ethyl ketone dissolved in 85 parts by mass of methyl ethyl ketone and 25 parts by mass of methyl ethyl ketone were mixed, and dispersion was performed for 2 hours in a sand mill using 1 mmφ glass beads to obtain a dispersion.
Dioctyltin dilaurate as a catalyst: 0.005 parts by mass, and silicone resin particles (Tospearl 145, manufactured by Momentive Performance Materials): 40 parts by mass as a catalyst were added to the obtained dispersion, and a coating liquid for forming an undercoat layer was added. Obtained.

  A cylindrical aluminum substrate having a diameter of 30 mm, a length of 340 mm and a thickness of 1 mm is prepared as a conductive substrate, and the obtained undercoat layer forming coating solution is applied onto the cylindrical aluminum substrate by dip coating. Drying curing was performed for 40 minutes at a temperature of 1 ° C. to obtain an undercoat layer having a thickness of 18.7 μm.

-Preparation of charge generation layer-
The Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generation material is at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° A mixture comprising 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak in 10% by mass, vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.) as a binder resin, and 200 parts by mass of n-butyl acetate The mixture was dispersed for 4 hours with a sand mill using glass beads of 1 mm in diameter. 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added to the obtained dispersion, and the mixture was stirred to obtain a coating liquid for forming a charge generation layer.
The obtained coating solution for forming a charge generation layer was dip-coated on the undercoat layer previously formed on a cylindrical aluminum substrate, and dried at normal temperature (25 ° C.) to form a charge generation layer having a thickness of 0.2 μm. It formed.

-Preparation of charge transport layer-
First, polycarbonate copolymer (1) was obtained as follows.
4, 10, 1 g (0.398 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane (hereinafter referred to as "Z") under a nitrogen atmosphere in a flask equipped with a phosgene blowing tube, a thermometer and a stirrer 24.7 g (0.133 mol) of 4'-dihydroxybiphenyl (hereinafter referred to as "BP"), 0.41 g of hydrosulfite, 825 ml of a 9.1% aqueous solution of sodium hydroxide (2.018 mol of sodium hydroxide), chloride 500 ml of methylene was charged and dissolved, and the mixture was stirred and kept in the range of 18 ° C. or more and 21 ° C. or less, and 76.2 g (0.770 mol) of phosgene was blown for 75 minutes to cause phosgenation reaction. After completion of the phosgenation reaction, 1.11 g (0.0075 mol) of p-tert-butylphenol and 54 ml of a 25% aqueous sodium hydroxide solution (0.266 mol of sodium hydroxide) are added and stirred, while 0.18 mL (0.0013) of triethylamine is added. Mol) was added and reacted for 2.5 hours at a temperature of 30.degree. C. or more and 35.degree. C. or less. The separated methylene chloride phase was acid-washed and washed with water until inorganic salts and amines were eliminated, and then methylene chloride was removed to obtain a polycarbonate copolymer (1). In this polycarbonate, the molar ratio of Z to BP was 75:25.

  Next, 25 parts by mass of N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] biphenyl-4,4'-diamine (TPD), the following structural formula (A) 20 parts by mass of a compound represented by the following formula, and 55 parts by mass of a polycarbonate copolymer (1) (viscosity average molecular weight: 50,000) as a binder resin are added to 560 parts by mass of tetrahydrofuran and 240 parts by mass of toluene and dissolved: A coating solution was obtained. The coating solution was applied onto the charge generation layer and dried at 135 ° C. for 45 minutes to form a charge transport layer having a thickness of 20 μm.

-Preparation of protective layer-
100 parts by mass of “exemplified compound (I-d) -28” as a reactive charge transporting material (chain polymerizable charge transporting material) and 2 parts by mass of VE-073 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator And 5 parts by mass of antioxidant "Sumilyzer MDP-S (manufactured by Sumitomo Chemical Co., Ltd.), 2,2'-methylene bis (6-t-butyl-4-methylphenol)" and 300 parts by mass of isobutyl acetate The mixture was stirred and mixed at room temperature for 12 hours to prepare a coating solution for forming a protective layer.

  Next, the obtained coating solution for forming a protective layer was coated on the charge transport layer previously formed on the cylindrical aluminum substrate by a ring coating method at a pushing speed of 180 mm / min. Thereafter, in a nitrogen dryer having an oximeter, a curing reaction was carried out at a temperature of 160 ± 5 ° C. for 60 minutes in a state of an oxygen concentration of 200 ppm or less to form a protective layer. The film thickness of the protective layer was 12 μm.

  As described above, a photosensitive member (1) was produced. The produced photosensitive body (1) was attached to an image forming apparatus "Fuji Xerox Co., Ltd. (Docucentre-IV C2260)". Then, an image pattern shown in FIG. 6 was output by the image forming apparatus, and an initial image quality test was conducted to confirm that an image having a target image density can be obtained.

[Photoreceptors (2) to (24), Reference Photoreceptor (R1)]
In the same manner as in the method described for the photosensitive member (1), an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a cylindrical aluminum substrate by coating. Thereafter, according to Table 1, the composition of the coating solution for forming a protective layer [type and amount of reactive charge transport material (denoted as “RCTM” in the table), non-reactive charge transport material (denoted as “CTM” in the table) The protective layer is formed in the same manner as the photosensitive member (1) except that the type and amount of antioxidant, the type and amount of antioxidant, and the type and amount of additive] and the thickness of the protective layer are changed. (2) to (24), a reference photosensitive member (R1) was produced. Then, an initial image quality test was conducted in the same manner as in the photosensitive member (1).
As a result of the initial image quality test, the photosensitive member (22) remarkably lowered its density, and the protective layer with a film thickness of 12 μm could not fulfill its function as a photosensitive member.
The reference photoreceptor (R1) on which the protective layer of 5 μm thickness is formed has a smaller wear rate than the photosensitive body (22) and can extend its life, but the protective layer can be thickened. The life of the photosensitive member (1) etc. is further increased.

[Comparative Example photoconductor (C1)]
In the same manner as in the method described for Photosensitive Member 1, a subbing layer and a charge generation layer were sequentially formed on a cylindrical aluminum substrate by coating.
Next, 25 parts by mass of N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] biphenyl-4,4'-diamine (TPD), shown by the structural formula (A) 20 parts by weight of the compound to be used, and 55 parts by weight of a polycarbonate copolymer (1) (viscosity average molecular weight: 50,000) as a binder resin, 7.3 parts by weight of PTFE fine particles (Lublon L-2, manufactured by Daikin), fluorocarbon resin (GF-400, manufactured by Toagosei Co., Ltd.) 0.35 parts by mass, antioxidant "Sumilyzer MDP-S (manufactured by Sumitomo Chemical Co., Ltd.), 2,2'-methylene bis (6-t-butyl-4-methylphenol) 5 parts by mass is dissolved in 560 parts by mass of tetrahydrofuran and 240 parts by mass of toluene and dissolved, and dispersion treatment is performed with a high-pressure wet medialess atomization device (Nanomizer NMS-200ED, manufactured by Nanomizer Inc.), A charge transport layer coating solution was obtained. The coating solution was applied onto the charge generation layer and dried at 135 ° C. for 45 minutes to form a charge transport layer having a thickness of 40 μm.
The comparative photoreceptor (C1) was produced as described above. Then, an initial image quality test was conducted in the same manner as in the photosensitive member (1).

[Comparative Example photoconductor (C2)]
In the same manner as in the method described for the photosensitive member (1), an undercoat layer, a charge generation layer, and a charge transport layer were sequentially formed on a cylindrical aluminum substrate by coating. Thereafter, the photosensitive member (1) is used except that the antioxidant "Sumilyzer MDP-S (manufactured by Sumitomo Chemical Co., Ltd.), 2,2'-methylenebis (6-t-butyl-4-methylphenol)" is not used. Similarly, a protective layer was formed, and a comparative photosensitive member (C2) was produced. Then, an initial image quality test was conducted in the same manner as in the photosensitive member (1).

<Preparation of Toner Particles>
[Production of cyan (C) toner particles (1)]
-Synthesis of crystalline polyester resin (1)-
After 124 parts by mass of ethylene glycol, 22.2 parts by mass of dimethyl 5-sulfoisophthalate, 213 parts by mass of dimethyl sebacate and 0.3 parts by mass of dibutyltin oxide as a catalyst are put into a heat-dried three-necked flask, The air in the container was brought into an inert atmosphere with nitrogen gas by a pressure reduction operation, and stirring was performed at 180 ° C. for 5 hours by mechanical stirring. Thereafter, the temperature was gradually raised to 220 ° C. under reduced pressure and the mixture was stirred for 4 hours. When it became viscous, air cooling was performed to stop the reaction, and 220 parts by mass of crystalline polyester resin (1) was synthesized.
In gel permeation chromatography molecular weight measurement by (in terms of polystyrene), the weight average molecular weight of the resulting crystalline polyester resin (1) _{(M W)} is 19000, the number average molecular weight _{(M n)} was 5800.
Further, the melting point (Tm) of the crystalline polyester resin (1) is measured using a differential scanning calorimeter (DSC) by the above-mentioned measuring method, and it has a clear peak, and the temperature of the peak top is 70 ° C. Met.

-Preparation of resin dispersion (1)-
150 parts by mass of the crystalline polyester resin (1) is put in 850 parts by mass of distilled water, mixed and stirred by a homogenizer (UltraTaracus manufactured by IKA Japan Co., Ltd.) while heating to 80 ° C., resin particle dispersion (1 Got). Next, 250 parts by mass of phthalocyanine pigment (Dainichi Seika Co., Ltd. product: PV FAST BLUE), 20 parts by mass of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd. product: Neogen RK), 700 parts by mass of ion exchanged water After mixing and dissolving, they were dispersed using a homogenizer (manufactured by IKA: Ultra-Taracus) to prepare a colorant dispersion liquid (1) in which the colorant (phthalocyanine pigment) is dispersed.

-Preparation of aggregated particles-
Resin particle dispersion (1) 2400 parts by mass, colorant dispersion (1) 100 parts by mass, release agent particle dispersion liquid 63 parts by mass, aluminum sulfate 6 parts by mass (manufactured by Wako Pure Chemical Industries, Ltd.), ion-exchanged water 100 The mass part is contained in a round stainless steel flask, adjusted to pH 2.0, dispersed using a homogenizer (manufactured by IKA: Ultra-Tarlax T50), and heated to 60 ° C. in a heating oil bath Heated while stirring. After holding at 60 ° C. for 2 hours, observation with an optical microscope confirmed that aggregated particles having an average particle diameter of about 4.3 μm were formed. After further heating and stirring at 60 ° C. for 1 hour, observation with an optical microscope confirmed that aggregated particles having a volume average particle diameter of 4.4 μm were formed.
The pH of this aggregated particle liquid was 2.4. Therefore, an aqueous solution of sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) diluted to 0.5% by mass is gently added to adjust the pH to 5.0, and then heated to 75 ° C. while continuing the stirring for 3 hours I kept it.
Thereafter, the reaction product is filtered, sufficiently washed with ion exchange water, and dried using a vacuum drier to obtain cyan toner particles (1). The melting point of the cyan toner particle was 65.degree.
The obtained cyan toner particles (1) had a volume average particle diameter of 4.5 μm and a shape factor SF1 of 133.

[Yellow (Y) toner particles (1)]
A yellow (Y) toner particle (1) was obtained with the same formulation except that a yellow-azo pigment was used instead of the phthalocyanine pigment in the preparation of the cyan toner particle (1).

[Magenta (M) toner particles (1)]
A magenta (M) toner particle (1) was obtained by the same formulation except that a quinacridone pigment was used instead of the phthalocyanine pigment in the preparation of the cyan toner particle (1).

[Black (K) toner particles (1)]
A black (K) toner particle (1) was obtained by the same formulation, except that carbon black was used instead of the phthalocyanine pigment in the preparation of the cyan toner particle (1).

<Preparation of developer>
[Developer 1]
100 parts by mass of the obtained four color toner particles (1), 0.5 parts by mass of silica particles (volume average particle diameter 40 nm) treated with hexamethyldisilazane as an external additive, and isobutyltrimethoxy in metatitanic acid 0.7 parts by mass of titanium compound particles (volume average particle diameter 30 nm) obtained by firing after 50% treatment with silane and zinc stearate particles as fatty acid metal salt particles (Nissan Electol MZ-2, median based on volume) 0.18 parts by weight of 1.5 μm in diameter, manufactured by NOF Corporation, is mixed for 10 minutes with a 75 L Henschel mixer, and then sifted with a wind screen sieving machine Hi-Bolter 300 (manufactured by Toyo Hitech Co., Ltd.) to obtain 4 colors Each toner (1) was produced separately.

  Next, a mixture of 0.15 parts by mass of vinylidene fluoride and 1.35 parts by mass of a copolymer of methyl methacrylate and trifluoroethylene (polymerization ratio 80: 20) with 100 parts by mass of the ferrite core is prepared. Using a kneader, a ferrite core having an average particle diameter of 50 μm was resin-coated (coated) to prepare a carrier.

  Then, 8 parts by mass of each of the obtained four toners (1) and 100 parts by mass of the obtained carrier were mixed in a 2-liter V blender to prepare four color developers. A set of the obtained four color developers was used as a developer (1).

[Developer 2]
In the preparation of each of the four color toners (1), in the same manner as each of the four color toners (1) except that the amount of zinc stearate particles was changed from 0.18 parts by mass to 0.12 parts by mass, 4 Each color toner (2) was prepared.
Then, a developer (2) was produced in the same manner as the developer (1) except that the obtained four toners (2) were used instead of the four toners (1).

[Developer 3]
In the preparation of each of the four color toners (1), in the same manner as each of the four color toners (1), except that the amount of zinc stearate particles was changed from 0.18 parts by mass to 0.03 parts by mass, 4 Color toners (3) were prepared respectively.
Then, a developer (3) was produced in the same manner as the developer (1) except that the obtained four toners (3) were used instead of the four toners (1).

[Developer 4]
Zinc stearate particles (zinc stearate) in place of zinc stearate particles (Nissan Electol MZ-2, median diameter 1.5 μm by volume, manufactured by NOF Corporation) in the preparation of each toner (1) of four colors Each of the four color toners (4) was prepared in the same manner as the four color toners (1) except that S and a median diameter 12 μm based on volume, manufactured by NOF Corporation, were used.
Then, a developer (4) was produced in the same manner as the developer (1) except that the obtained four toners (4) were used instead of the four toners (1).

[Developer 5]
In the preparation of each of the four toners (1), each of the four toners (5) was prepared in the same manner as the four toners (1) except that zinc stearate particles were not added.
Then, a developer (5) was produced in the same manner as the developer (1) except that the obtained four toners (5) were used instead of the four toners (1).

[Developer 6]
In the preparation of each of the four color toners (1), in the same manner as each of the four color toners (1) except that the amount of zinc stearate particles was changed from 0.18 parts by mass to 0.25 parts by mass, 4 Color toners (6) were prepared respectively.
Then, a developer (6) was produced in the same manner as the developer (1) except that the obtained four toners (6) were used instead of the four toners (1).

[Developer 7]
In the preparation of each of the four color toners (1), in the same manner as each of the four color toners (1) except that the amount of zinc stearate particles was changed from 0.18 parts by mass to 0.06 parts by mass, 4 Color toners (7) were prepared respectively.
Then, a developer (7) was produced in the same manner as the developer (1) except that the obtained four toners (7) were used instead of the four toners (1).

[Developer 8]
Zinc stearate particles (zinc stearate) in place of zinc stearate particles (Nissan Electol MZ-2, median diameter 1.5 μm by volume, manufactured by NOF Corporation) in the preparation of each of the four color toners (1) Four toners (8) were produced in the same manner as the four toners (1), respectively, except that FP, a median diameter of 5.5 μm based on volume, manufactured by NOF Corporation were used.
Then, a developer (8) was produced in the same manner as the developer (1) except that the obtained four toners (8) were used instead of the four toners (1).

[Developer 9]
Zinc stearate particles (zinc stearate) in place of zinc stearate particles (Nissan Electol MZ-2, median diameter 1.5 μm by volume, manufactured by NOF Corporation) in the preparation of each of the four color toners (1) Each toner of four colors except for the amount of zinc stearate particles changed from 0.18 parts by mass to 0.005 parts by mass using FP, a median diameter based on volume, 5.5 μm, manufactured by NOF Corporation In the same manner as in the above, four toners (9) were prepared.
Then, a developer (9) was produced in the same manner as the developer (1) except that the obtained four toners (9) were used instead of the four toners (1).

<Preparation of Cleaning Blade>
[Cleaning blade (1)]
First, a member for the first layer was formed as follows.
First, as a polyol component, polycaprolactone polyol (manufactured by Daicel Chemical Industries, Plaxel 205, average molecular weight 529, hydroxyl value 212 KOHmg / g) and polycaprolactone polyol (manufactured by Daicel Chemical Co., Plaxel 240, average molecular weight 4155, hydroxyl number 27 KOHmg / g And a soft segment material composed of an acrylic resin (Atoflow UMB-2005B, manufactured by Soken Chemical Co., Ltd.) containing two or more hydroxyl groups in a ratio of 8: 2 (mass ratio) did.

Next, with respect to 100 parts of a mixture of the hard segment material and the soft segment material, as an isocyanate compound, 4,4′-diphenylmethane diisocyanate (Nippon Polyurethane Industry Co., Ltd., Millionate MT, hereinafter referred to as “MDI”) is 6.26. A portion was added and allowed to react at 70 ° C. for 3 hours under a nitrogen atmosphere. The amount of isocyanate compound used in this reaction is selected such that the ratio of isocyanate group to hydroxyl group (isocyanate group / hydroxyl group) contained in the reaction system is 0.5.
Subsequently, 34.3 parts of the above isocyanate compound was further added, and the mixture was reacted at 70 ° C. for 3 hours under a nitrogen atmosphere to obtain a prepolymer.
In addition, the total amount of the isocyanate compound utilized in using the prepolymer is 40.56 parts.

  Next, this prepolymer is heated to 100 ° C. and degassed for 1 hour under reduced pressure, and then a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60 per 100 parts of prepolymer). 7.14 parts of / 40) were added, and thoroughly mixed so as not to cause bubbles for 3 minutes, to prepare a composition for forming a first layer A1.

  Subsequently, the composition A1 for forming the first layer was poured into a centrifugal molding machine whose mold was adjusted to 140 ° C., and curing reaction was performed for 1 hour to form a flat first layer.

On the other hand, a composition for forming a second layer A1 prepared by the following method as a member for the second layer was prepared.
Diphenylmethane-4,4-diisocyanate is mixed with dehydrated polytetramethylether glycol and reacted at 120 ° C for 15 minutes, and the formed prepolymer is used in combination with 1,4-butadiol and trimethylolpropane as a curing agent. Using.

  Next, the composition A1 for forming the second layer is poured into a centrifugal molding machine after forming the first layer in a flat plate shape as described above, and cured, and the second layer is formed on the back surface of the first layer. It formed.

Then, the flat plate having the second layer formed on the back surface of the first layer obtained is crosslinked after being crosslinked for 24 hours at 110 ° C., cooled, and cut into the desired dimensions, the first layer thickness 0.5 mm, the second layer A cleaning blade (1) having a thickness of 1.5 mm (thickness ratio of 25% of the total thickness) was obtained.
In addition, when the physical property in a 1st layer single layer was measured, it was as follows.
· 100% modulus M = 7.4 MPa
· Α = 0.09 (MPa /%)
· Elongation at break S = 535%
· Rebound resilience R = 35%
Glass transition temperature Tg = -8 ° C.

<Examples 1 to 27, Comparative Examples 1 to 9>
The photoreceptor, the developer, and the cleaning blade were mounted on an image forming apparatus ("Docucentre-IV C2260" manufactured by Fuji Xerox Co., Ltd.) equipped with a charging device of a contact charging type in the combination according to Table 2. This image forming apparatus was used as the image forming apparatus of Examples 1 to 27 and Comparative Examples 1 to 9.

<Evaluation>
The image forming apparatus shown in each example outputs the image pattern shown in FIG. 6 to an A4 sheet, and an initial image quality test is performed to confirm that an image having a target image density can be obtained.
Next, a job pattern for continuously outputting three sheets of the image pattern shown in FIG. 6 onto A4 paper is as follows: 1) 70,000 sheets (photosensitive member 200,000 rotations (at a temperature of 20 ° C., humidity 50% RH) 2) 70,000 sheets at low temperature and low humidity (temperature 10 ° C, humidity 15% RH) 3) 70,000 sheets at high temperature and humidity (temperature 29 ° C, humidity 85% RH) The output test to output was carried out. The output of this image pattern was carried out in the short direction conveyance of A4 paper [P paper made by Fuji Xerox].

At the end of each output test in each environment, 1) evaluation of the electrical characteristics of the photoreceptor, 2) average wear rate of the photoreceptor (nm / 1000 rotations), maximum wear rate (nm / 1000 rotations), and minimum wear rate ( 3) Evaluation of wear cross section (μm ² ) of cleaning blade, 4) Evaluation of chipping of cleaning blade, 5) Evaluation of image quality, and 6) Evaluation of external additive slip through.

(Electrical characteristics of photoreceptor)
The electrical characteristics of the photosensitive member are determined by providing a surface potential probe in the area to be measured using the surface potential meter (TREK 334, manufactured by Trek Co., Ltd.) after removing the residual charge (the surface of the electrophotographic photosensitive member 1), and the difference (ΔRp) between the initial residual potential and the residual potential after printing of 50,000 sheets in each environment was calculated. And about the residual potential, it evaluated by the following evaluation criteria.
A +: Less than 20 V A: 20 V or more and less than 50 V B: 50 V or more and less than 80 V C: 80 V or more

(Abrasion rate of photoreceptor)
The average wear rate of the photosensitive member, the maximum wear rate of the photosensitive member, and the minimum wear rate of the photosensitive member were measured by the methods described above. In the table, the unit "(nm / 1000 rotation)" is omitted. The notation of each wear rate in each table is as follows.
・ “Wm”: Average wear rate of photoreceptor at normal temperature and humidity environment ・ “Wmmax”: Maximum wear rate of photoreceptor at normal temperature and humidity environment ・ “Wmmin”: Minimum wear of photoreceptor at normal temperature and humidity environment Rate · "Wl": Average wear rate of photoreceptor in low temperature and low humidity environment · "Wlmax": Maximum wear rate of photoreceptor in low temperature and low humidity environment · "Wlmin": Minimum wear rate of photoreceptor in low temperature and low humidity environment · "Wh": Average wear rate of photoreceptor at high temperature and high humidity environment "Whmax": Maximum wear rate of photoreceptor at high temperature and high humidity environment "Whmin": Minimum wear rate of photoreceptor at high temperature and high humidity environment

(Abrasion cross section of cleaning blade)
The portion of the cleaning blade in contact with the photosensitive member was observed with a laser microscope to measure the wear cross-sectional area. The wear cross-sectional area was determined as the area obtained by subtracting the wear cross-sectional area after the output test from the cross-sectional area of the portion where the initial blade contacts the photosensitive member. And the following evaluation criteria evaluated about the wear cross-sectional area of the cleaning blade.
A +: less than 10μm ² A: 10μm ² or more 20 [mu] m ² less B: less 20 [mu] m ² or more 40μm ² C: 40μm ² or more

(Missing of cleaning blade)
After the output test in each environment, one solid image with an image density of 30% was further output to A4 paper, and the occurrence of streaks on the image was observed. And the following evaluation criteria evaluated about the crack of the cleaning blade.
A +: no streaks generated A: minor streaks of 3 or less were generated B: streaks of more than 3 and less than 10 were generated C: clear streaks of 10 or more were generated

(image quality)
After completion of the output test in each environment, one solid image with an image density of 30% was further output on A4 paper, the obtained image was observed, and the image flow and density unevenness were evaluated according to the following evaluation criteria.

-Evaluation criteria of image flow-
A +: no image flow at all A: no image flow to cause image quality problems B: slight image flow generation C: image flow problems to cause image quality problems

-Evaluation criteria for uneven density-
A +: No occurrence of uneven density A: No occurrence of uneven density B: Some occurrence of uneven density C: Occurrence of uneven density

(External additive slip through)
After the output test in each environment, one solid image with an image density of 30% is further output to A4 paper, and then a total of three photosensitive members of the central part of the axial direction and the part of 5 cm from both ends. The surface was observed with a laser microscope, and the average of the number of external additives observed in the area of 100 μm ² was evaluated by the following evaluation criteria.
A +: The number of external additives is less than 5 A: The number of external additives is 5 or more and less than 10 B: The number of external additives is 10 or more and less than 20 C: The number of external additives is 20 or more

(Comprehensive evaluation)
The above evaluations were integrated, and the electrophotographic photoreceptor and the image forming system were comprehensively evaluated. The evaluation criteria are as follows.
A +: Particularly excellent A: Excellent B: There are some problems but there are no major problems in practical use C: There are practical problems

  The details of each example and the evaluation results are listed in Tables 1 to 5 below.

From the above results, it can be seen that in the present example, evaluation of density unevenness is better than in the comparative example.
In this example, it is understood that the electrical characteristics (residual potential) of the photosensitive member, the wear cross-sectional area (μm ² ) of the cleaning blade, the chipping of the cleaning blade, the external additive slip-through, and the evaluation of the image flow are also good.

  From the evaluation results of the comparative example, when three types of image patterns having different image densities as shown in FIG. 6 are continuously output, the wear rate of the photosensitive member greatly varies depending on the image pattern. Since a film thickness difference occurs, it can be seen that unevenness in density tends to appear. Since the wear of the photosensitive member tends to progress at low temperatures where the hardness of the cleaning blade increases, the maximum wear rate Wlmax of the photosensitive member in a low temperature and low humidity environment is preferably as small as possible taking into account the wear of the cleaning blade, 10 nm It turns out that / Kcycle or less is more preferable.

The details of the respective abbreviations shown in the table are shown below.
[RCTM: Reactive Charge Transport Material]
(I-d) -28: exemplified compound (I-d) -28 (see the synthesis method below)
(I-b) -23: exemplified compound (I-b) -23
(I-b) -28: exemplified compound (I-b) -28
(I-c) -23: exemplified compound (I-c) -23
(I-c) -53: exemplified compound (I-c) -53
(I-d) -20: exemplified compound (I-d) -20
・ (II) -50: Exemplified compound (II) -50
(II) -56: exemplified compound (II) -56
・ (II) -182: exemplified compound (II) -181
(II) -182: exemplified compound (II) -182
-Compound (B): a compound represented by the following structural formula (B)

-Synthesis of Exemplified Compound (Id)-28-
In a 500 ml flask, 22 g of the following compound (2), 33 g of potassium t-butoxide, 300 ml of tetrahydrofuran and 0.2 g of nitrobenzene were added, and a solution of 25 g of 4-chloromethylstyrene in 150 ml of tetrahydrofuran was stirred while stirring under a nitrogen stream. It dripped slowly. After completion of the dropwise addition, the mixture was heated under reflux for 4 hours, cooled, poured into water and extracted with toluene. The toluene layer was sufficiently washed with water and then concentrated, and the obtained oil was purified by silica gel column chromatography to obtain 29 g of an exemplary compound (Id)-28 as an oil.

  Other exemplified compounds were synthesized according to the above synthesis.

[CTM: non-reactive charge transport material]
-Compound (C): a compound represented by the following structural formula (C)

[Antioxidant]
-MDS-S: SMILIZER MDP-S (manufactured by Sumitomo Chemical Co., Ltd.), 2,2'-methylenebis (6-t-butyl-4-methylphenol)
-144: Tinuvin 144 (manufactured by BASF), bis (1,2,2,6,6-pentamethyl-4-piperidyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] Methyl] butyl malonate · TPS: Sumilyzer TPS (manufactured by Sumitomo Chemical Co., Ltd.)

[Additive]
· L-2: tetrafluoroethylene polymer particles: Rubron L-2 (manufactured by Daikin Industries, Ltd.))

DESCRIPTION OF SYMBOLS 1 ... undercoat layer, 2 ... charge generation layer, 3 ... charge transport layer, 4 ... conductive substrate, 5 ... protective layer, 6 ... single layer type photosensitive layer, 7A, 7B, 7C, 7 ... electrophotographic photosensitive member, 8: charging device, 9: exposure device, 11: developing device, 13: cleaning device, 131: cleaning blade, 132: lower seal, 133: toner accumulation sheet, 40: transfer device, 50: intermediate transfer member, 100: image formation Device 120: Image forming device 300: Process cartridge

Claims (8)

The surface of an electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed. Charging the surface of the electrophotographic photosensitive member by charging means disposed in contact with or in proximity to the
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged;
Developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer including toner having toner particles and fatty acid metal salt particles to form a toner image;
A transfer step of transferring the toner image to the surface of a recording medium;
A cleaning step of cleaning the surface of the electrophotographic photosensitive member with a cleaning blade in contact with the surface of the electrophotographic photosensitive member;
Have
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
An image forming method which satisfies the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2).
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5   The image forming method according to claim 1, wherein the fatty acid metal salt particles are particles of zinc stearate having a median diameter of 0.1 μm or more and 10.0 μm or less based on volume.   The image forming method according to claim 1, wherein the antioxidant is a radical polymerization inhibitor.   The image forming method according to any one of claims 1 to 3, wherein the reactive charge transporting material is a chain polymerizable compound having at least a charge transporting skeleton and a chain polymerizable functional group in the same molecule. The image according to any one of claims 1 to 3, wherein the reactive charge transporting material is at least one selected from chain polymerizable compounds represented by the following general formulas (I) and (II). Formation method.


[In general formula (I), F shows a charge transportable skeleton. L represents a divalent linking group containing two or more selected from the group consisting of an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S- and -O- Show. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. m represents an integer of 1 or more and 8 or less. ]


[In general formula (II), F shows a charge transportable skeleton. L 'is a trivalent or tetravalent group derived from alkane or alkene, and an alkylene group, an alkenylene group, -C (= O)-, -N (R)-, -S-, and -O- The (n + 1) valent linking group containing 2 or more types selected from the group which consists of these is shown. R represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. m 'represents an integer of 1 or more and 6 or less. n represents an integer of 2 or more and 3 or less. ]   The image forming method according to any one of claims 1 to 5, wherein the formula: 0.01 <Rmf <0.18 is satisfied. An electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed;
A charging unit disposed in contact with or in close proximity to the surface of the electrophotographic photosensitive member to charge the surface of the electrophotographic photosensitive member;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged;
Developing means for containing a developer containing toner having toner particles and fatty acid metal salt particles, and developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member by the developer to form a toner image When,
A transfer unit that transfers the toner image to the surface of a recording medium;
A cleaning unit having a cleaning blade that contacts the surface of the electrophotographic photosensitive member and cleans the surface of the electrophotographic photosensitive member;
Equipped with
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
An image forming apparatus which satisfies the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2).
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5 An electrophotographic photosensitive member comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, and a cured film of a composition containing a reactive charge transport material and an antioxidant, wherein the outermost surface layer is formed;
A charging unit disposed in contact with or in close proximity to the surface of the electrophotographic photosensitive member to charge the surface of the electrophotographic photosensitive member;
Developing means for containing a developer containing toner having toner particles and fatty acid metal salt particles, and developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member by the developer to form a toner image When,
A cleaning unit having a cleaning blade that contacts the surface of the electrophotographic photosensitive member and cleans the surface of the electrophotographic photosensitive member;
Equipped with
The content of the fatty acid metal salt particles relative to the total mass of the toner is Rmf (mass%),
The average wear rate of the electrophotographic photosensitive member is Wh (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a high temperature and high humidity environment, and the maximum wear of the electrophotographic photosensitive member Rate is Whmax (nm / 1000 rotation), and the minimum wear rate of the electrophotographic photosensitive member is Whmin (nm / 1000 rotation),
The average wear rate of the electrophotographic photosensitive member is Wl (nm / 1000 revolutions) when an image including three image patterns different in image density is repeatedly formed in a low temperature and low humidity environment, and the maximum wear rate of the electrophotographic photosensitive member Where Wlmax (nm / 1000 rotations) and the minimum wear rate of the electrophotographic photosensitive member is Wlmin (nm / 1000 rotations),
Satisfy the following formula (A1), the following formula (B1), the following formula (B2), the following formula (C1) and the following formula (C2),
Process cartridge to be attached to and removed from the image forming apparatus.
-Formula (A1): 0.01 <Rmf <0.20
Formula (B1): 0.005 <Rmf / Wh <5.000
Formula (B2): 0.002 <Rmf / Wl <1.000
-Formula (C1): 1.0 <Whmax / Whmin <2.5
-Formula (C2): 1.0 <Wlmax / Wlmin <2.5