JP2011008098A - Charging member, charging device, process cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charging member, whose surface state is satisfactorily maintained when using an image forming apparatus, and then, in which the occurrence of image defects is prevented; and to provide a charging device, a process cartridge and the image forming apparatus.SOLUTION: The charging member includes at least an elastic layer 33 and a surface layer 34 which are sequentially formed on a conductive support 31, and a resin forming the surface layer 34 is a cured product of at least (a) to (c). In the state where a voltage is applied to the charging member, the charging member comes in contact with a body to be charged, to charge the body to be charged. (a) fluororesin containing at least one of a hydroxyl group and a carboxyl group. (b) glycols. (c) curing agent.

Description

  The present invention relates to a charging member, a charging device, a process cartridge, and a pixel forming apparatus.

An image forming apparatus using an electrophotographic method forms a charge on an image carrier (photosensitive member), forms an electrostatic latent image with a laser or the like that modulates an image signal, and then charges the electrostatic latent image with charged toner. The image is developed into a toner image. Then, a desired transfer image can be obtained by electrostatically transferring the toner image to the recording material medium via an intermediate transfer member.
In an image forming apparatus using an electrophotographic system, for example, a charging roll discharges in a very small space near the nip formed by contact with a photoconductor in the image forming apparatus to charge the photoconductor.

As for the charging roll, for example, a surface layer is formed of a polymer material having a dense molecular structure and excellent releasability, as represented by so-called resin, and generally to a highly adhesive elastic roll (charging roll) surface. Attempts have been made to reduce the adhesion of foreign objects (Patent Documents 1, 2, etc.)
JP-A-194061 Japanese Patent Laid-Open No. 1-204081 etc.

The object of the present invention is to solve the above-mentioned problems of the prior art.
That is, an object of the present invention is to provide a charging member in which the surface state of the charging member is good and the occurrence of image defects is prevented when the image forming apparatus is used.

The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1> At least an elastic layer and a surface layer are sequentially formed on the conductive support, and the resin forming the surface layer is at least a cured product of (a) to (c),
A charging member that contacts a member to be charged in a state where a voltage is applied to charge the member to be charged.
(A) Fluororesin containing at least one of a hydroxyl group and a carboxyl group (b) Glycols (c) Curing agent <2> 0.5 parts of (b) glycol is added to 100 parts by mass of (a) Fluororesin The charging member according to <1>, wherein the charging member is contained in an amount of not less than 25 parts by mass.
<3> The charging member according to <2>, wherein (b) glycols are contained in an amount of 10 parts by mass to 20 parts by mass with respect to 100 parts by mass of the (a) fluororesin.
<4> A charging device comprising a charging member, wherein the charging member is a charging member according to claim 1.
<5> A process cartridge including a charging device, wherein the charging device is the charging device according to claim 4.
<6> An image carrier, a charging unit for charging the image carrier, a latent image forming unit for forming a latent image on the surface of the charged image carrier, and a latent image formed on the surface of the image carrier. A developing unit that develops an image with a developer to form a toner image; a transfer unit that transfers a toner image formed on the surface of the image carrier to a transfer target; and the toner image that is in contact with the image carrier. An image forming apparatus comprising at least a fixing unit that fixes a toner image transferred to a transfer target to which the toner image is transferred, and a cleaning unit that removes residual toner on the surface of the image holding member after transfer. An image forming apparatus, wherein the charging unit includes the charging member according to any one of claims 1 to 3.

According to the first aspect of the present invention, it is possible to provide a charging member in which the surface state of the charging member is good and the occurrence of image defects is prevented when the image forming apparatus is used.
According to the second and third aspects of the invention, a better surface state of the charging member can be obtained as compared with the case where the blending ratio of glycols is not taken into consideration.
According to the fourth aspect of the present invention, it is possible to provide a charging device in which the surface state of the charging member is good and the occurrence of image defects is prevented when the image forming apparatus is used.
According to the fifth aspect of the present invention, it is possible to provide a process cartridge in which the surface state of the charging member is good and the occurrence of image defects is prevented when the image forming apparatus is used.
According to the invention of claim 6, it is possible to provide an image forming apparatus that prevents the occurrence of image defects.

  Hereinafter, embodiments of a charging member, a charging device, a process cartridge, and an image forming apparatus according to the present invention will be described in detail.

The charging member according to the embodiment of the present invention may have any of a roll shape, a rod shape, a plate shape, and a sheet shape, but a roller shape is particularly desirable. It has been found that when the resin forming the surface layer of these charging members is a cured product of at least (a) to (c), image defects due to adhesion of foreign matters are prevented when the image forming apparatus is used.
(A) a fluororesin containing at least one of a hydroxyl group and a carboxyl group (b) glycols (c) a curing agent

  Conventionally, attention has been paid to the surface layer material, and attempts have been made to reduce the adhesion of toner to the surface of the charging roll by forming the surface layer of the charging roll from a non-adhesive material such as a fluorine-based material or a silicone-based material. However, in particular, fluororesins have a high carbon-fluorine bond energy and are highly resistant to discharge and ozone generated during charging, and are effective in extending the life of the charging roll. There is lack of flexibility, and there is a tendency that cracks and cracks are likely to occur due to deterioration and fatigue, and foreign matter may adhere to the cracked portions.

The layer structure of the charging roll as the charging member according to the embodiment of the present invention is not particularly limited as long as at least an elastic layer and a surface layer are formed on the conductive support, but the conductive support and the elastic layer are not limited. A resistance layer or the like may be formed on the outer peripheral surface of the adhesive layer or the elastic layer in between (FIGS. 1 to 3). Here, “conductive” in the conductive support means that the resistance value is 1 × 10 ⁴ Ω or less. Examples of the conductive support include a metal or alloy such as stainless steel; plating with chromium, nickel or the like. An example is a support made of treated iron.

FIG. 1 shows a configuration of a charging roller according to a first embodiment of the charging member of the present invention. In FIG. 1, a conductive support 31 is covered with an elastic layer 33 via an adhesive layer 32, and a surface layer 34 is covered on the surface of the elastic layer 33.
FIG. 2 shows a configuration of a charging roller according to a second embodiment of the charging member of the present invention. In FIG. 2, a conductive support 31 is covered with an elastic layer 33 via an adhesive layer 32, the elastic layer 33 is covered with an intermediate layer 35, and the intermediate layer 35 is covered with a surface phase 4. .
FIG. 3 shows a configuration of a charging roller according to a third embodiment of the charging member of the present invention. In FIG. 3, the conductive support 31 is covered with an elastic layer 33, and the surface layer 34 is covered on the surface of the elastic layer 33.

  The elastic layer is formed of various rubbers and elastomers. Rubber and elastomer materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin- Examples include ethylene oxide-allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and blended rubbers thereof. Among these, polyurethane, silicone rubber, EPDM, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, NBR and blended rubbers thereof are preferably used. The elastic layer constituent material may be used as a resistance layer material when a resistance layer is formed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of the electronic conductive agent include carbon black such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, stainless steel; tin oxide, indium oxide, titanium oxide And fine powders of various conductive metal oxides such as tin oxide-antimony oxide solid solution and tin oxide-indium oxide solid solution;

Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals ;
These conductive agents may be used alone or in combination of two or more.
The amount of addition is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the rubber material. More preferably, it is in the range of no more than parts by mass. On the other hand, in the case of the ionic conductive agent, it is preferably in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the rubber material, and 0.5 to 3.0 parts by mass. The following range is more preferable.

The material constituting the surface layer is not particularly limited as long as it is a cured product of at least (a) to (c).
(A) a fluororesin containing at least one of a hydroxyl group and a carboxyl group (b) glycols (c) a curing agent

<Fluorine resin>
Examples of the fluororesin containing at least one of a hydroxyl group and a carboxyl group include vinyl ether type, vinyl ester type copolymerized tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), vinylidene fluoride (VDF), and hexafluoro. Examples thereof include propylene (HFP) and copolymers thereof, but those modified with silicon are preferable from the viewpoint of releasability, and a fluororesin siloxane graft polymer is particularly preferable. The fluororesin preferably has a hydroxyl value of 10 or more and 200 or less, more preferably 20 or more and 120 or less, and still more preferably 55 or more and 120 or less.

<Glycols>
Examples of glycols include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyoxyethylene-monomethyl ether, polyoxyethylene-dimethyl ether, polyoxyethylene-glyceryl ether, polyoxypropylene-glyceryl ether, and polytetramethylene glycol. .
The molecular weight of glycols is preferably from 200 to 4,000, more preferably from 500 to 2,000. When the molecular weight is in the above range, the photoreceptor contamination due to unreacted components can be suppressed and flexibility tends to be imparted.

  The glycol is preferably 1 part by mass or less and 20 parts by mass or more with respect to 100 parts by mass of the fluororesin solid content. When the blending amount is in the above range, sufficient flexibility can be imparted, the high releasability of the fluororesin can be maintained, and the unreacted component tends to be inhibited from affecting the photoreceptor contamination and the like.

<Curing agent>
Examples of the curing agent include isocyanate and amino resin. Curing with isocyanate is preferable from the viewpoint of flexibility. The blending ratio of the fluororesin and the curing agent is not particularly limited as long as it is not dissolved by a solvent after curing, but is preferably 60% or more in terms of gel fraction by acetone.
The blending amount when isocyanate is blended is preferably NCO / OH (or COOH) = 0.8 or more and 1.5 or less / 1.0, and NCO / OH (or COOH) = 1.0 or more and 1.2 or less / 1.0 is more preferable.
It is desirable in terms of compatibility and reactivity that (a) to (c) are liquid under the conditions of blending.

  The polymer material for forming the resin layer on the intermediate layer other than the surface layer is not particularly limited, but polyamide, polyurethane, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, polyimide, silicone resin, acrylic Examples thereof include resins, polyvinyl butyral, ethylene tetrafluoroethylene copolymer, melamine resin, fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride, polyethylene, and ethylene vinyl acetate copolymer.

The above polymer materials may be used alone or in combination of two or more. Further, the number average molecular weight of the polymer material is preferably in the range of 1,000 or more and 100,000 or less, and more preferably in the range of 10,000 or more and 50,000 or less.
The surface layer is formed as a composition by mixing the above polymer material with the conductive agent used in the elastic layer as the conductive agent and various particles. Although there is no restriction | limiting in particular in the addition amount, It is preferable that it is the range of 1 mass part 50 mass parts or less with respect to 100 mass parts of polymeric materials, and it is more preferably the range of 5 mass parts or more and 20 mass parts or less. preferable.
Examples of the particles include metal oxides such as silicon oxide, aluminum oxide, and barium titanate, and composite metal oxides, and polymer fine powders such as tetrafluoroethylene and vinylidene fluoride. The adhesive layer, which is not limited to the above, is made of thermosetting or thermoplastic resin or rubber-based material, but a conductive agent may be added if necessary.

Next, an embodiment of the image forming apparatus of the present invention will be described with reference to the drawings.
FIG. 4 is a cross-sectional view schematically showing the basic configuration of the image forming apparatus according to the first embodiment of the present invention. An image forming apparatus 200 illustrated in FIG. 4 includes an electrophotographic photosensitive member 207, a charging device 208 that charges the electrophotographic photosensitive member 207, a power source 209 connected to the charging device 208, and an electrophotographic image that is charged by the charging device 208. An exposure device 206 that exposes the photosensitive member 207 to form a latent image, a developing device 211 that develops the latent image formed by the exposure device 206 with toner and forms a toner image, and a toner that is formed by the developing device 211 The image forming apparatus includes a transfer device 212 that transfers an image to an object to be transferred (image output medium) 500, a cleaning device 213, a static eliminator 214, and a fixing device 215. The charging member which is an embodiment of the present invention is used for the charging device 208. In this case, there is a case where the static eliminator 214 is not provided.

A charging device 208 in FIG. 4 is of a type (contact charging type) in which a conductive member (charging roll) is brought into contact with the surface of the electrophotographic photosensitive member 207 to charge the surface of the photosensitive member 207 (contact charging method). A charging device according to an embodiment of the present invention is used.
As the exposure device 206, an optical system device or the like that exposes a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surface of the electrophotographic photosensitive member in a desired image-like manner.

  Further, an embodiment of the process cartridge of the present invention is a cartridge provided with an electrophotographic photosensitive member 207, a charging device 208, and a cleaning device 213 in FIG.

  The transfer device 212 can supply a current having a predetermined current density to the electrophotographic photosensitive member when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the transfer target 500. Preferably there is.

  The cleaning device 213 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process. The cleaned electrophotographic photosensitive member is repeatedly used for the image forming process described above. . As the cleaning device, a cleaning blade, brush cleaning, roll cleaning, or the like is used. Among these, it is preferable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  The image forming apparatus according to the embodiment of the present invention may further include a light irradiation device as the charge eliminator 214 as shown in FIG. As a result, when the electrophotographic photosensitive member is repeatedly used, the phenomenon that the residual potential of the electrophotographic photosensitive member is brought into the next cycle is prevented, so that the image quality can be further improved.

  FIG. 5 is a cross-sectional view schematically showing a basic configuration of an image forming apparatus according to the second embodiment of the present invention. The image forming apparatus 210 shown in FIG. 5 transfers the toner image formed on the electrophotographic photosensitive member 207 to the primary transfer member 212a and then supplies it between the primary transfer member 212a and the secondary transfer member 212b. A transfer device of an intermediate transfer system for transferring to a transfer target (image output medium) 500 to be transferred, and at the time of such transfer, a predetermined current density from the primary transfer member 212a toward the electrophotographic photosensitive member. Current is supplied. Although not shown in FIG. 5, the image forming apparatus 210 may further include a static eliminator as in the image forming apparatus 200 shown in FIG. Other configurations of the image forming apparatus 210 are the same as those of the image forming apparatus 200.

As described above, the image forming apparatus 210 is different in that the intermediate transfer method is applied. However, as in the case of the image forming apparatus 200 according to the first embodiment, the charging device according to the embodiment of the present invention. By combining with, good image quality can be stably obtained over a long period of time.
Further, when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the primary transfer member 212a, a current having a predetermined current density is supplied from the primary transfer member 212a to the electrophotographic photosensitive member 207. As a result, fluctuations in the transfer current due to the type and material of the transfer medium 500 are suppressed, and the amount of charge flowing into the electrophotographic photosensitive member 207 is accurately controlled. As a result, higher image quality and reduced environmental impact can be achieved at a higher level.

  FIG. 6 is a sectional view schematically showing a basic configuration of an image forming apparatus according to the third embodiment of the present invention. An image forming apparatus 220 shown in FIG. 6 is an intermediate transfer type image forming apparatus. In the housing 400, four electrophotographic photoreceptors 401a to 401d (for example, the electrophotographic photoreceptor 401a is yellow and the electrophotographic photoreceptor 401b is magenta). The electrophotographic photosensitive member 401c can form an image of cyan and the electrophotographic photosensitive member 401d can form a black color) are arranged in parallel along the intermediate transfer belt 409.

  Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 220 each have a hydroxygallium phthalocyanine having a maximum peak wavelength in a range of 810 nm to 839 nm in a spectral absorption spectrum in a wavelength region of 600 nm to 900 nm. An electrophotographic photosensitive member having a photosensitive layer containing

  Each of the electrophotographic photosensitive members 401a to 401d is rotated in a predetermined direction (counterclockwise on the paper surface), and along the rotation direction, the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can supply toners of four colors, yellow, magenta, cyan, and black, which are accommodated in toner cartridges 405a to 405d. These toners satisfy the condition that the average shape factor is 100 to 140. Further, the primary transfer rolls 410a to 410d are in contact with the electrophotographic photosensitive members 401a to 401d via the intermediate transfer belt 409, respectively.

  Further, a laser light source (exposure device) 403 is disposed at a predetermined position in the housing 400, and the surfaces of the electrophotographic photoreceptors 401a to 401d after charging are irradiated with laser light emitted from the laser light source 403. It is possible to do. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner. Here, in the tandem type color image forming apparatus, the electrophotographic photoreceptors 401a to 401d having the photosensitive layer containing the specific hydroxygallium phthalocyanine are combined with each color toner having an average shape factor of 100 to 140. In addition, high image quality and reduction of environmental burden can be achieved at a high level.

  The intermediate transfer belt 409 is supported by a driving roll 406, a support roll 408, and a tension applying roll 407 with a predetermined tension, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to come into contact with the support roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 that has passed between the support roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A paper feeding unit (paper feeding unit for a medium to be transferred) 411 is provided at a predetermined position in the housing 400, and the medium to be transferred 500 such as paper in the paper feeding unit 411 is transferred by the transfer roll 412. After being sequentially transferred between the intermediate transfer belt 409 and the secondary transfer roll 413 and between the two fixing rolls 414 in contact with each other, the paper is discharged to the outside of the housing 400.

In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. There may be.
When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. An elastic layer may be coated on the cylindrical base material as necessary, and a surface layer may be formed on the elastic layer.

  Hereinafter, the present invention will be specifically described with reference to conductive elastic rolls as examples, but the present invention is not limited to these examples.

<Example 1>
<Formation of elastic layer>
A mixture having the following composition is kneaded with an open roll, and an elastic layer is formed on the surface of a conductive support having a diameter of 8 mm made of SUM23L, the surface of which is nickel-plated, using a press molding machine via an adhesive layer, and vulcanized. An elastic roll A having a diameter of 14 mm was obtained.
-100 parts by mass of rubber material (epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber Gechron 3106: manufactured by Nippon Zeon Co., Ltd.)
-Conductive agent (carbon black Asahi Thermal: Asahi Carbon Co., Ltd.) 15 parts by mass-Conductive agent (Ketjen Black EC: Lion Corp.) 5 parts by mass-Ion conductive agent (lithium perchlorate) 1 part by mass-Vulcanizing agent (Sulfur 200 mesh: manufactured by Tsurumi Chemical Co., Ltd.) 1 part by mass, vulcanization accelerator (Noxeller DM: manufactured by Ouchi Shinsei Chemical Co., Ltd.) 2.0 parts by mass, vulcanization accelerator (Noxeller TT: Ouchi New Chemical Co., Ltd.) 0.5 parts by mass, vulcanization accelerating aid (Zinc oxide, zinc oxide 1 type: manufactured by Shodo Chemical Co., Ltd.) 3 parts by mass, 1.5 parts by mass of stearic acid

<< Formation of surface layer >>
Dispersion A obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll A, and then heated and dried at 180 ° C. for 30 minutes to form a surface layer having a thickness of 7 μm. Thus, a charging roll 1 was obtained.
・ 100 parts by mass of fluororesin (solvent soluble fluororesin solution fluorinate K700, hydroxyl value 51: manufactured by Dainippon Ink & Chemicals, Inc.)
-Glycols 5 parts by mass (polypropylene glycol Uniol D2000, molecular weight 2000, pour point <-30 ° C: manufactured by NOF Corporation)
・ 58 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 40 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)

<Evaluation>
The charging roll 1 is mounted on a color copier DocuCenter Color a450: Fuji Xerox drum cartridge and printed on 50,000 sheets of A4 paper (after printing 25,000 sheets in a low temperature and low humidity (10 ° C., 15% RH) environment) After durability test by high temperature and high humidity (printing 25,000 sheets in 28 ° C, 85% RH) environment, image quality evaluation by low temperature and low humidity and high temperature and high humidity by 50% halftone printing and contamination state of charging roll surface Observations were made. The results are shown in Table 1.

<Image quality evaluation criteria>
A: Density unevenness, white spots, and color spots are not generated.
○: Minor density unevenness, white spots, and color spots partially occur.
Δ: Minor density unevenness, white spots, and color spots occur.
X: Density unevenness, white spots, and color spots occur.

<Contamination condition standard of charging roll surface>
A: Slight foreign matter adhering.
○: Adhesion of foreign matter on the entire surface Δ: Partial adhesion of foreign matter
X: Foreign matter adhered to the entire roll surface.
※ ・ ・ ・ Adhesion is a level that can be easily wiped off with waste cloth. Fixation is a level that cannot be wiped off easily with waste.

<High temperature and high humidity storage>
The drum cartridge equipped with the charging roll 1 was stored for one month in a high temperature and high humidity (45 ° C., 95% RH) environment, and then image quality evaluation was performed at room temperature (25 ° C.). The results are shown in Table 1.

<Example 2>
<Formation of elastic layer>
Elastic roll B was obtained in the same manner as Example 1.
<< Formation of surface layer >>
Dispersion B obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll B, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. Thus, a charging roll 2 was obtained.
-Fluororesin 100 parts by mass (fluorine resin siloxane graft polymer solution ZX-007-C hydroxyl value 58: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 3.5 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
Curing agent 102 parts by mass (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Example 3>
<Formation of elastic layer>
An elastic roll C was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion C obtained by dispersing the following mixture with a bead mill was diluted with MEK, dip-coated on the surface of the conductive elastic roll C, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. To obtain a charging roll 3.
-Fluororesin 100 parts by mass (fluorine resin siloxane graft polymer solution ZX-022 hydroxyl value 120: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 4.5 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
・ 151 parts by weight of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 25 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Example 4>
<Formation of elastic layer>
An elastic roll D was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion D obtained by dispersing the following mixture in a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll D, then heated and dried at 180 ° C. for 30 minutes, and a surface layer having a thickness of 7 μm And the charging roll 4 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 3.5 parts by mass (polypropylene glycol Uniol TG1000, molecular weight 1000, pour point <−25 ° C .: manufactured by NOF Corporation)
・ 94 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 2.

<Example 5>
<Formation of elastic layer>
An elastic roll E was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion E obtained by dispersing the following mixture in a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll E, dried by heating at 180 ° C. for 30 minutes, and a surface layer having a thickness of 7 μm Thus, a charging roll 5 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 0.35 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
・ 94 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 2.

<Example 6>
<Formation of elastic layer>
An elastic roll F was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion E obtained by dispersing the following mixture in a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll F, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. And the charging roll 6 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 1.75 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
・ 94 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 2.

<Example 7>
<Formation of elastic layer>
An elastic roll G was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion E obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll G, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. Thus, a charging roll 7 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 7 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
・ 94 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 3.

<Example 8>
<Formation of elastic layer>
An elastic roll H was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion B obtained by dispersing the following mixture in a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll H, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. Thus, a charging roll 8 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 3.5 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
・ 122 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 3.

<Example 9>
<Formation of elastic layer>
An elastic roll c was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
A dispersion c obtained by dispersing the following mixture in a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll c, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. Thus, a charging roll 23 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
・ Glycols 0.18 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
Curing agent 102 parts by mass (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 3.

<Example 10>
<Formation of elastic layer>
An elastic roll d was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
A dispersion d obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll d, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. Thus, a charging roll 24 was obtained.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
-Glycols 8.8 parts by mass (polypropylene glycol Uniol D2000: manufactured by NOF Corporation)
Curing agent 102 parts by mass (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 4.

<Comparative Example 1>
<Formation of elastic layer>
The elastic roll a was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
A dispersion liquid a obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll a, dried by heating at 180 ° C. for 30 minutes, and a surface layer having a thickness of 7 μm. Thus, a charging roll 21 was obtained.
・ 100 parts by mass of fluororesin (solvent soluble fluororesin solution fluorinate K700: manufactured by Dainippon Ink & Chemicals, Inc.)
・ 58 parts by mass of curing agent (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 40 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 4.

<Comparative Example 2>
<Formation of elastic layer>
An elastic roll b was obtained in the same manner as in Example 1.
<< Formation of surface layer >>
Dispersion b obtained by dispersing the following mixture with a bead mill is diluted with MEK, dip-coated on the surface of the conductive elastic roll b, and then heated and dried at 180 ° C. for 30 minutes to obtain a surface layer having a thickness of 7 μm. To obtain a charging roll 22.
・ 100 parts by mass of fluororesin (fluororesin siloxane graft polymer solution ZX-007-C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
Curing agent 102 parts by mass (polyisocyanate solution coronate L: manufactured by Nippon Polyurethane Industry Co., Ltd.)
-Conductive agent 20 parts by mass (antimony-doped tin oxide SN-100P: manufactured by Ishihara Sangyo Co., Ltd.)
<Evaluation>
Evaluation was conducted in the same manner as in Example 1, and the results are shown in Table 4.

It is sectional drawing which shows 1st Embodiment of the charging member of this invention. It is sectional drawing which shows 2nd Embodiment of the charging member of this invention. It is sectional drawing which shows 3rd Embodiment of the charging member of this invention. 1 is a schematic configuration diagram showing a first embodiment of an image forming apparatus of the present invention. It is a schematic block diagram which shows 2nd Embodiment of the image forming apparatus of this invention. It is a schematic block diagram which shows 3rd Embodiment of the image forming apparatus of this invention.

31 ... conductive support, 32 ... adhesive layer, 33 ... elastic layer, 34 ... surface layer, 35 ... intermediate layer, 200, 210, 220 ... image forming apparatus, 207 ... electron Photographic photosensitive member 208 ... charging device 209 ... power source 210 ... exposure device 211 ... developing device 212 ... transfer device 213 ... cleaning device 214 ... static discharger 215 ... fixing device 216 ... mounting rail 217 ... Opening for static elimination exposure, 218 ... Opening for exposure, 300 ... Process cartridge, 400 ... Housing, 401a-b ... Electrophotographic photosensitive member, 402a-402d ... Charging roll, 403 ... Laser light source (exposure) Device), 404a to 404d, developing device, 405a to 405d, toner cartridge, 406, drive roll, 407, tension applying roll, 408, support Roll, 409 ... Intermediate transfer belt, 410a to 410d, Primary transfer roll, 411 ... Feeding means (transfer material feeding means), 412 ... Transfer roll, 413 ... Secondary transfer roll, 414 ... Fixing roll, 415a- 415d ... Cleaning blade, 416 ... Cleaning blade, 500 ... Transfer object

Claims (6)

At least an elastic layer and a surface layer are sequentially formed on the conductive support, and the resin forming the surface layer is at least a cured product of (a) to (c),
A charging member that contacts a member to be charged in a state where a voltage is applied to charge the member to be charged.
(A) a fluororesin containing at least one of a hydroxyl group and a carboxyl group (b) glycols (c) a curing agent   2. The charging member according to claim 1, wherein (b) glycol is contained in an amount of 0.5 to 25 parts by mass with respect to 100 parts by mass of (a) fluororesin.   The charging member according to claim 2, wherein (b) glycols are contained in an amount of 10 parts by weight to 20 parts by weight with respect to 100 parts by weight of the (a) fluororesin.   A charging device comprising a charging member, wherein the charging member is the charging member according to claim 1.   A process cartridge comprising a charging device, wherein the charging device is the charging device according to claim 4.   An image carrier, charging means for charging the image carrier, latent image forming means for forming a latent image on the surface of the charged image carrier, and developing the latent image formed on the surface of the image carrier Developing means for forming a toner image by developing with an agent, transfer means for transferring the toner image formed on the surface of the image carrier to a transfer target, and the toner image being transferred in contact with the image carrier. At least a fixing unit that fixes the toner image transferred to the transfer target, and a cleaning unit that removes residual toner on the surface of the image holding member after transfer. An image forming apparatus comprising the charging member according to any one of items 3 to 3.