JP6570286B2 - Image forming method - Google Patents

Description

  The present invention relates to an image forming method using an electrophotographic recording system such as a laser printer, a copying machine, and a facsimile.

  An electrophotographic image forming apparatus forms a charge on an image carrier, forms an electrostatic latent image on the image carrier with a laser beam modulated with an image signal, and then develops the electrostatic latent image with toner. The toner image is visualized and transferred to the toner image via a transfer device to obtain a desired image.

As a transfer device, there is an intermediate transfer system in which a toner image on an image carrier is primarily transferred to an intermediate transfer belt, and is secondarily transferred from the intermediate transfer belt to a transfer material to form a toner image on the transfer material.
As a method for removing the secondary transfer residual toner on the intermediate transfer belt, a blade cleaning method is known in which the transfer residual toner is physically collected by a cleaning blade disposed downstream of the secondary transfer unit. Generally, an elastic body such as urethane rubber is used for the cleaning blade.

  In recent years, in order to further improve the image quality, there has been a demand for improved efficiency in transferring a toner image from an intermediate transfer belt to a transfer material. For example, Patent Document 1 discloses that a filler having a particle size smaller than the particle size of the toner is embedded on the surface of the intermediate transfer belt to improve the surface physical properties, so that the toner does not remain on the intermediate transfer belt and transfer efficiency is improved. Have been described. Further, Patent Document 2 describes an intermediate transfer belt in which toner is not left on the intermediate transfer belt and transfer efficiency is improved by optimizing the surface roughness of the intermediate transfer belt.

JP 2009-75154 A JP 2004-240176 A

  At present, the image forming apparatus is required to have further durability, and the intermediate transfer belt using the blade cleaning method needs to be further improved in durability by repeated use.

  As a result of the study by the present inventors, the intermediate transfer belt of Patent Document 1 has a problem in terms of wear of the cleaning blade due to repeated use. When the protrusion shape of the filler is scattered on the surface of the intermediate transfer belt, the cleaning blade edge portion gradually begins to be worn from the contact point with the protrusion shape by repeated use. As a result, the cleaning blade edge portion is unevenly worn or chipped, and there is a concern that toner may slip through (hereinafter referred to as “cleaning failure”). Further, since the intermediate transfer belt defining the surface roughness value of Patent Document 2 includes a surface layer having a protruding shape as in Patent Document 1, there is a concern that the amount of wear of the cleaning blade edge portion may also increase. These blade cleaning type intermediate transfer belts have room for improvement in reducing the wear of the cleaning blade in long-term use.

  The present invention provides an image forming apparatus including an intermediate transfer belt that can improve both the efficiency of toner transfer from the intermediate transfer belt to the transfer material and the suppression of the amount of wear of the cleaning blade in repeated use over a long period of time. Objective.

The present invention
A charging step of charging the image bearing member with a charging means;
An exposure step of exposing the charged image carrier to form an electrostatic latent image;
A developing step of developing the electrostatic latent image with toner to form a toner image on the image carrier;
A transfer step of transferring the toner image to a transfer material via an intermediate transfer belt;
A fixing step of fixing a toner image on the transfer material, and a cleaning step of removing residual transfer toner remaining on the intermediate transfer belt with a cleaning blade;
An image forming method comprising:
The surface of the intermediate transfer belt has a groove shape in a direction crossing the cleaning blade, and the width of the groove shape is less than half of the weight average particle diameter (D4) of the toner;
In the toner with a weight average particle diameter of the four-way (D4μm × D4μm), plane average roughness of the surface of the intermediate transfer belt, and a 10nm or more 30nm or less,
The ten-point average roughness Rzjis of the surface of the intermediate transfer belt in the direction perpendicular to the rotation direction of the intermediate transfer belt is 0.26 μm or more and 0.67 μm or less,
The toner is
Toner particles containing a binder resin, a colorant, and a release agent;
Silica fine particles,
Containing
The present invention relates to an image forming method , wherein the toner satisfies the following formulas (1) and (2).
300 (mJ) ≦ E ≦ 450 (mJ) (1)
1.00 ≦ Ec / E ≦ 2.30 (2)

(In the above formulas (1) and (2),
E is a powder flowability analyzer that allows the peripheral speed of the outermost edge of the propeller blade to rotate at 100 mm / s while vertically entering the toner powder layer in the container, and from the bottom surface of the toner powder layer. The sum (mJ) of rotational torque and vertical load obtained when measurement is started from a position of 100 mm and entered from the bottom to a position of 10 mm is shown.
Ec represents the sum (mJ) of the rotational torque and the vertical load measured in the manner of measuring E in the toner powder layer given a load of 3 kPa. )

  According to the present invention, there is provided an image forming apparatus provided with an intermediate transfer belt that achieves both improvement in toner transfer efficiency from the intermediate transfer belt to a transfer material and suppression of the amount of wear of the cleaning blade in repeated use over a long period of time. be able to.

Schematic views (a) and (b) showing a cross section of the intermediate transfer belt and a schematic view (c) of the intermediate transfer belt as viewed from above are shown. 1 is a configuration diagram of an image forming apparatus having an intermediate transfer belt. FIG. 4 is a diagram illustrating a blade cleaning method for an intermediate transfer belt. The enlarged view (a, b, c) of the surface layer of an intermediate transfer belt is shown. The enlarged view (a, b, c, d) of the intermediate transfer belt surface layer and the cleaning blade nip portion is shown. It is a figure which shows the other aspect of the intermediate transfer belt which concerns on this invention. It is explanatory drawing of the external appearance (a) of the propeller-type blade of a powder fluidity | liquidity analyzer, and the twist angle (b) of a blade outermost edge part.

<Image forming apparatus>
First, a color image forming apparatus using four color toners will be described with reference to FIG. In the configuration shown in FIG. 2, the first station is yellow (Y), the second station is magenta (M), the third station is cyan (C), and the fourth station is black (K). In the first station, reference numeral 1a denotes a photosensitive drum as an image carrier, a charging roller 2a as a charging unit, a cleaning unit 3a for cleaning residual toner remaining on the image carrier 1a, and a developing unit 8a as a developing unit. Have The developing unit 8a includes a developing sleeve 4a, a non-magnetic one-component developer (also referred to as toner) 5a, and a developer application blade 7a. The above-described 1a to 8a are an integrated process cartridge 9a. The exposure means (not shown) is composed of a scanner unit that scans laser light with a polygon mirror, and irradiates the photosensitive drum 1a with a scanning beam 12a modulated based on an image signal. The process cartridges 9b to 9d in the second to fourth stations have the same configuration as the process cartridge 9a in the first station.

  Next, an image forming operation will be described. When the image forming operation starts, the photosensitive drums 1a to 1d, the intermediate transfer belt 13 and the like start to rotate in the arrow direction at a predetermined process speed. First, the operation of the first station will be described. First, the photosensitive drum 1a is uniformly charged to a negative polarity by a voltage supplied from a power source (not shown) to the charging roller 2a. Subsequently, an electrostatic latent image according to the image information is formed on the photosensitive drum 1a by a scanning beam 12a from an exposure unit (not shown). The toner 5a in the developing unit 8a is negatively charged by the developer application blade 7a and applied to the developing sleeve 4a. A voltage is supplied to the developing sleeve 4a from a developing voltage power source (not shown). When the electrostatic latent image formed on the photosensitive drum 1a reaches the developing sleeve 4a facing portion, the electrostatic latent image on the photosensitive drum 1a is visualized by negative toner, and the first color (on the photosensitive drum 1a ( In FIG. 2, a toner image Y) is formed. The second to fourth stations have the same configuration as the first station.

  On the other hand, the intermediate transfer belt 13 which is a toner image carrier is disposed so as to abut against all four photosensitive drums 1a to 1d. The intermediate transfer belt 13 is supported by three rollers, a support roller 24, a drive roller 14, and a tension roller 15, which are positioned opposite to the secondary transfer roller 25, so that appropriate tension is maintained. . By driving the drive roller 14, the intermediate transfer belt 13 moves in the forward direction (direction of arrow a) at substantially the same speed with respect to the photosensitive drums 1a to 1d. The primary transfer roller 10a is urged with a predetermined pressure to the photosensitive drum 1a via the intermediate transfer belt 13 to form a primary transfer nip.

  Electrostatic latent images are formed on the respective photosensitive drums 1a to 1d by exposure with a delay at a constant timing in accordance with the distance between the primary transfer nips for each color. Then, by applying a voltage having a polarity opposite to that of the toner from the primary transfer power sources 22a to 22d to each of the primary transfer rollers 10a to 10d, the toner images are sequentially transferred to the intermediate transfer belt 13, and the multiple toner is transferred onto the intermediate transfer belt 13. An image is formed.

  Thereafter, the transfer material S loaded on a recording medium cassette (not shown) is picked up by a paper supply roller (not shown) in accordance with the formation of an electrostatic latent image by exposure, and a registration roller 18 by a conveyance roller (not shown). It is conveyed to. The transfer material S is conveyed by the registration roller 18 to a secondary transfer nip portion formed by the intermediate transfer belt 13 and the secondary transfer roller 25 in synchronization with the toner image on the intermediate transfer belt 13. Thereafter, the secondary transfer power supply 26 applies a voltage having a polarity opposite to that of the toner to the secondary transfer roller 25, and the four-color multiple toner images carried on the intermediate transfer belt 13 are collectively put on the transfer material S. Secondary transferred.

In this embodiment, the primary transfer rollers 10a to 10d are configured by covering a core metal of a nickel-plated steel rod having an outer diameter of 5 mm with a foaming elastic body so as to have an outer diameter of 14 mm. If the primary transfer roller resistance is in the range of 10 ³ to 10 ⁷ Ω, good image formation can be performed. The secondary transfer roller 25 is configured by coating a core metal of a nickel-plated steel rod having an outer diameter of 8 mm with a foaming elastic body so as to have an outer diameter of 16 mm. If the secondary transfer roller resistance is in the range of 10 ⁷ to 10 ⁹ Ω, good image formation can be performed. The drive roller 14 used had an outer diameter of 26.3 mm covered with silicone rubber having a resistance of 10 ⁵ Ω and a wall thickness of 0.085 mm in which carbon was dispersed in an aluminum core. The tension roller 15 as a stretching member applies a tension of 49 N on one side and a total pressure of 98 N to the intermediate transfer belt 13 using an aluminum metal rod having an outer diameter of 24 mm. As the support roller 24 positioned opposite the secondary transfer roller 25, a support roller 24 having an outer diameter of 18 mm coated with EPDM rubber having a resistance of 10 ⁵ Ω and a thickness of 1 mm in which carbon is dispersed as a conductive agent in an aluminum core metal was used. The transfer material S is conveyed to the fixing unit 19 after the completion of the secondary transfer, and is fixed to the toner image, and is discharged out of the image forming apparatus as an image formed product.

<Blade cleaning of intermediate transfer belt>
Next, cleaning of the intermediate transfer belt in the color image forming apparatus will be described. FIG. 3A schematically shows a portion where the cleaning unit 27 and the intermediate transfer belt 13 are in contact with each other. The cleaning means 27 is an elastic cleaning blade 28 made of urethane rubber. The cleaning blade 28 has a structure in which a rubber part 29 made of polyurethane rubber is bonded to a sheet metal part 30 made of a plated steel plate, and the thickness of the rubber part 29 is 2 mm, for example. The rubber part 29 had a hardness of 77 ° according to JIS K6253 standard. The cleaning blade 28 is configured to swing, and the cleaning shaft is fixed around the swing shaft 32 by fixing the swing shaft 32 to an intermediate transfer belt unit (not shown) and pressurizing the sheet metal 30 with a pressure spring 31. 28 moves. A tension roller 15 is disposed inside the intermediate transfer belt 13 so as to face the rubber portion 29. The cleaning blade 28 contacts the tension roller 15 in the counter direction with respect to the rotational driving direction of the intermediate transfer belt 13, and scrapes off the transfer residual toner at the nip portion 33 (FIG. 3B). In this way, after the secondary transfer is completed, the transfer residual toner remaining on the intermediate transfer belt 13 is removed and collected from the surface by the intermediate transfer belt cleaning unit 27.

The mounting position of the cleaning blade 28 is set at a set angle θ (angle formed by the tangent to the tension roller 15 at the intersection of the intermediate transfer belt 13 and the cleaning blade rubber portion 29 and the cleaning blade rubber portion 29), and the intrusion amount δ. The length in the thickness direction in which the cleaning blade rubber part 29 overlaps the tension roller 15 is 1.5 mm, and the contact pressure of the cleaning blade 28 is 0.6 N / cm ² . By setting to this setting position, the color image forming apparatus of this embodiment has a cleaning blade turning and slipping noise in a high temperature and high humidity environment (temperature 30 ° C./humidity 80%), and a low temperature and low humidity environment (temperature 15). Good cleaning performance can be obtained without causing poor cleaning at a temperature of 10 ° C./humidity.

The above cleaning configuration is appropriately selected according to the intermediate transfer belt material. Preferably, the material of the cleaning blade rubber portion 29 is polyurethane rubber. Further, the hardness of the cleaning blade rubber part 29 is preferably in the range of 70 degrees to 80 degrees in accordance with JIS K6253 standard. Further, the contact pressure of the cleaning blade 28 against the intermediate transfer belt, 0.4 N / cm ² or more 0.8N / cm ² or less.

<Configuration of intermediate transfer belt>
Next, the configuration of the intermediate transfer belt of the present invention will be described. The intermediate transfer belt 13 is preferably an endless film-like member composed of two or more layers having a base layer and a surface layer. FIG. 1A shows an enlarged partial cross-sectional view in the direction orthogonal to the rotational driving direction in the vicinity of the surface layer of the intermediate transfer belt 13. The base layer 101 is a layer having a thickness of 70 μm in which carbon black is dispersed as a resistance adjusting agent in a polyethylene naphthalate resin. The surface layer 102 is a layer having a thickness of 3 μm in which antimony-doped zinc oxide particles 105 are dispersed as a resistance adjusting agent in an acrylic resin 103 and polytetrafluoroethylene (hereinafter referred to as PTFE) particles 104 are added. As shown in FIG. 1A, the PTFE particles 104 added to the surface layer 102 are deposited on the outermost surface and form a protrusion shape in a partially exposed state, and are also dispersed in the surface layer. Existing.

  Further, the surface of the surface layer 102 is subjected to a surface processing treatment to have a groove shape. This groove shape is a direction crossing the cleaning blade. FIG. 1B shows a sectional view of the groove shape formed in the surface layer 102. The width of the groove shape (groove width 111) is less than half of the weight average particle diameter (D4) of the toner. In FIG. 1B, the groove width 111 of the groove shape 110 is 2 μm. The groove depth 112 is 1 μm. The pitch 113 of the groove shape 110 is 10 to 20 μm. Since the thickness of the surface layer 102 is 3 μm, the groove shape 110 does not reach the base layer 101 and exists only in the surface layer 102. FIG. 1C shows the intermediate transfer belt 13 as viewed from above. The groove shape 110 exists over the entire circumference of the intermediate transfer belt 13 along the rotational driving direction of the intermediate transfer belt 13. In FIG. 1C, the groove shape 110 is in a positional relationship orthogonal to the longitudinal contact portion of the cleaning blade rubber portion 29.

When the volume resistivity of the intermediate transfer belt 13 is in the range of 10 ⁹ to 10 ¹² Ω · cm, using Hiresta UP MCP-HT450 (manufactured by Mitsubishi Chemical Corporation), good image formation can be performed.

<Method for producing intermediate transfer belt>
Next, a method for producing the intermediate transfer belt 13 will be described. The surface of the intermediate transfer belt is preferably made of an acrylic copolymer. Specifically, the surface layer of the intermediate transfer belt is composed of an acrylic copolymer.

  First, as a material used for the base layer 101 of the intermediate transfer belt 13 of the present invention, for example, polycarbonate, polyvinylidene fluoride (PVDF), polyethylene, polypropylene, polymethylpentene-1, polystyrene, polyamide, polysulfone, polyarylate, polyethylene Examples include thermoplastic resins such as terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyphenylene sulfide, polyethersulfone, polyethernitrile, thermoplastic polyimide, polyetheretherketone, thermotropic liquid crystal polymer, and polyamic acid. It is done. Two or more of these can be mixed and used. In addition, the base material 101 of the intermediate transfer belt 13 can be obtained by melt-kneading a conductive material or the like in these thermoplastic resins and then appropriately selecting a molding method such as inflation molding, cylindrical extrusion molding, or blow molding. .

  Next, a method for manufacturing the surface layer 102 will be described. From the viewpoint of improving the surface hardness and durability (abrasion resistance) of the intermediate transfer belt, the surface layer preferably contains a cured product of a composition containing a curable monomer and / or oligomer component. Examples of the curing means include curing by irradiation with energy rays such as ultraviolet rays and electron beams, and curing by heat. Curing by irradiation with ultraviolet rays or electron beams is preferable.

  Examples of the curable material include curable resins such as melamine resin, urethane resin, alkyd resin, acrylic resin, and fluorinated curable resin. Examples of inorganic materials include alkoxysilane / alkoxyzirconium-based materials and silicate-based materials. Examples of the organic / inorganic hybrid material include inorganic fine particle-dispersed organic polymer materials, inorganic fine particle-dispersed organoalkoxysilane materials, acrylic silicon materials, and organoalkoxysilane materials.

  Examples of the curable monomer and / or oligomer component include unsaturated double bond-containing acrylic copolymers. The base layer contains an acrylic copolymer that is a cured product of the composition containing the unsaturated double bond-containing acrylic copolymer. The unsaturated double bond-containing acrylic copolymer is available, for example, as lucifural (trade name, manufactured by Nippon Paint Co., Ltd.).

  Further, a conductive material may be added to the intermediate transfer belt surface layer 102 for resistance control. As the conductive material, an electron conductive material or an ion conductive material can be used. Examples of the electronically conductive material include carbon black, PAN-based carbon fibers, and carbon-based conductive fillers in the form of particles, fibers, or flakes such as pulverized expanded graphite. Furthermore, particulate, fibrous, or flaky metallic conductive fillers such as silver, nickel, copper, zinc, aluminum, stainless steel, and iron are also included. In addition, particulate metal oxide conductive fillers such as antimony-doped tin oxide, tin-doped indium oxide, and aluminum-doped zinc oxide can be used. Examples of the ion conductive material include an ionic liquid, a conductive oligomer, and a quaternary ammonium salt. These conductive materials may be used alone or in combination of two or more. Among these, a particulate metal oxide based conductive filler of submicron or less is preferable, and antimony-doped zinc oxide particles and the like can be mentioned.

  Further, a solid lubricant may be added to the intermediate transfer belt surface layer 102. Examples of solid lubricants include PTFE resin powder, ethylene trifluoride chloride resin powder, ethylene tetrafluoride hexafluoropropylene resin powder, vinyl fluoride resin powder, vinylidene fluoride resin powder, difluoride difluoride. Fluorine-containing particles such as ethylene chloride resin powder, fluorinated graphite, and copolymers thereof are appropriately selected. Solid lubricants such as silicone resin particles and molybdenum disulfide powder may also be used. Among these, polytetrafluoroethylene (PTFE) resin particles are preferable in that the wear of other members in contact with the intermediate transfer belt surface layer 102 can be reduced.

  Examples of a method for forming the surface layer 102 on the base layer 101 include a normal coating method such as dip coating, spray coating, roll coating, spin coating, and the like. By appropriately selecting from these methods, the surface layer 102 having a desired film thickness can be obtained.

  A groove shape 110 is formed on the surface layer 102 of the intermediate transfer belt obtained by the above method. The intermediate transfer belt 13 is elastically deformed and attached to a cylinder having an outer diameter slightly larger than the inner diameter of the intermediate transfer belt 13. Then, a wrapping film (Lapika # 2000 (trade name), manufactured by KOVAX) using aluminum oxide having a particle size of 9 μm as abrasive grains is brought into contact with the surface of the intermediate transfer belt 13 mounted on the cylinder. Thereafter, the cylinder is rotated for 40 seconds to obtain the intermediate transfer belt 13 in which the groove shape 110 is formed in the surface layer 102. The method for imparting the groove shape 110 to the intermediate transfer belt is to bring the wrapping film into contact with the surface layer 102 and rotate the intermediate transfer belt 13 or to rub the wrapping film in the rotational direction of the intermediate transfer belt 13. A groove shape 110 can be formed.

  The intermediate transfer belt 13 having a groove shape can be produced by any method. For example, a method of imparting a surface form to the surface of the base layer 101 before surface layer coating, post-processing using a mold or a nanoimprint technique, and the like can be mentioned, but there is no particular limitation.

<Relationship between intermediate transfer belt surface layer and transfer efficiency>
In order to improve the transfer efficiency when transferring the toner on the intermediate transfer belt 13 to the transfer material S, the surface layer 102 of the intermediate transfer belt needs to be smooth. Specifically, the in-plane average roughness of the surface of the intermediate transfer belt in the toner weight average particle diameter square (D4 μm × D4 μm) is 10 nm or more and 30 nm or less.

  When the in-plane average roughness of the surface layer 102 as shown in FIG. 4A is 30 nm or less and the ratio of the smooth portion is dominant, the contact opportunity (contact area) between the toner and the surface layer 102 is small. Mainly point contact. As a result, the physical adhesive force acting between the toner and the surface layer 102 is weak and the releasability of the toner is improved, so that the transfer efficiency is improved.

However, when the in-plane average roughness is less than 10 nm, the contact with the cleaning blade that collects the transfer residual toner is increased by being pressed against the surface of the intermediate transfer belt, so that the cleaning blade easily wears and the cleaning performance is impaired. It is easy.
Further, as shown in FIG. 4B, when the in-plane average roughness of the surface layer 102 is larger than 30 nm and there is no smooth portion, there are many opportunities for contact between the toner and the surface layer (contact area), and both are mainly large. Point contact. As a result, the physical adhesive force acting between the toner and the surface layer 102 is strong and the releasability of the toner is deteriorated, so that the transfer efficiency is lowered.

  As shown in FIG. 4C, in the surface layer 102 in which the in-plane average roughness of the surface of the intermediate transfer belt is 10 nm or more and 30 nm or less and the groove shape 110 having the groove width 111 of less than half of the average toner particle diameter is formed. For example, in the case of a spherical toner, the toner may be present on the groove. Since the groove width 111 is smaller than the toner particle size, the toner on the groove exists in two-point contact with the surface layer 102 without being buried in the groove portion. Therefore, the physical adhesion acting between the toner and the surface layer 102 is weaker than that of the surface layer 102 (FIG. 4B) where no smooth portion exists, and a groove width shape less than half of the average toner particle size is formed. As a result, the transfer efficiency is not greatly impaired. Therefore, it can have a surface shape suitable for blade cleaning described later.

<Relationship between intermediate transfer belt surface and cleaning blade wear>
In order to satisfy the cleaning performance of the intermediate transfer belt 13, the surface layer 102 of the intermediate transfer belt needs to have an appropriate roughness.

  The groove shape 110 formed on the surface layer 102 of the intermediate transfer belt intersects the longitudinal contact portion of the cleaning blade rubber portion 29. FIG. 5A shows the vicinity of the nip portion between the cleaning blade rubber portion 29 and the intermediate transfer belt surface layer 102. Since the cleaning blade rubber portion 29 does not contact the groove portion, the contact area with the intermediate transfer belt 13 at the nip portion is reduced. As a result, the frictional force at the nip portion during rotation of the intermediate transfer belt 13 is reduced, and blade wear is suppressed. Further, since the groove width 111 of the groove shape 110 is less than the average toner particle diameter, it is possible to prevent the toner from entering the groove portion and slipping through the cleaning blade. On the other hand, when the surface layer 102 having no groove shape is present as shown in FIG. 5B, the cleaning blade rubber portion 29 is in close contact with the intermediate transfer belt 13 at the nip portion. For this reason, the frictional force at the nip portion during the rotational driving of the intermediate transfer belt 13 is large, and the blade wear progresses due to repeated use, resulting in poor cleaning. Further, as shown in FIG. 5C, when the shape is given to the surface layer 102 and it has a random uneven shape, the cleaning blade rubber portion 29 contacts the convex portion of the surface layer 102 at the nip portion. Therefore, the cleaning blade rubber portion 29 is intensively applied to the contact region portion with the surface layer 102 at the nip portion, and the frictional force at the contact region portion increases. As a result, blade wear locally progresses due to repeated use, and uneven wear and chipping occur, resulting in poor cleaning. Further, as shown in FIG. 5 (d), when the surface layer 102 has a convex shape by adding a filler or the like, the cleaning blade rubber portion 29 contacts the convex portion of the surface layer 102 at the nip portion as in FIG. 5 (c). To do. Therefore, the cleaning blade rubber portion that comes into contact with the convex portion of the surface layer 102 is locally worn by repeated use, and uneven wear and chipping occur, resulting in poor cleaning.

  Thus, in order to obtain good cleaning performance over a long period of time, it is desired to reduce the contact area between the cleaning blade and the intermediate transfer belt at the blade nip portion. Then, the groove is formed on the smooth surface of the intermediate transfer belt along the moving direction of the surface of the intermediate transfer belt (that is, in a direction intersecting the longitudinal direction of the contact portion between the cleaning blade 29 and the intermediate transfer belt 13). This is accomplished by forming 110.

  The ratio of the contact area between the intermediate transfer belt 13 and the cleaning blade 29 to the total surface area of the intermediate transfer belt 13 within the range of the cleaning blade 29 in the direction orthogonal to the belt conveyance direction (within the region where the blade and the belt face each other). Contact area ratio. The contact area ratio can be obtained in detail by a measurement method described later as a ratio of the total surface area in an arbitrary region of the surface layer 102 of the intermediate transfer belt 13 and the contact region portion with the cleaning blade 29. In this case, in order to obtain good cleaning performance due to the frictional force reducing effect as described above, the contact area ratio is preferably 80% or more and 97% or less. When the contact area ratio is less than 80%, the surface layer 102 of the intermediate transfer belt 13 that is in contact with the cleaning blade 29 is small, and pressure is intensively applied to the contact region, so that the amount of wear of the cleaning blade 29 is likely to increase. . On the other hand, when the contact area ratio is greater than 97%, the effect of reducing the frictional force due to the reduction of the contact portion does not appear, and the amount of cleaning blade wear tends to increase.

  As described above, the groove 110 is appropriately formed on the surface of the intermediate transfer belt 13 along the belt conveyance direction, thereby improving the transfer efficiency of the toner from the intermediate transfer belt 13 to the transfer material S and cleaning blade. 29 can be suppressed.

Further, the ten-point average roughness Rzjis of the surface of the intermediate transfer belt in the direction orthogonal to the rotation direction of the intermediate transfer belt is 0.26 μm or more and 0.67 μm or less.
The surface roughness when the surface layer of the intermediate transfer belt is viewed macroscopically also affects the transfer efficiency and the wear of the cleaning blade. By setting Rzjis to 0.26 μm or more, local wear of the cleaning blade can be suppressed, and by setting it to 0.67 μm or less, high transfer efficiency can be maintained.

<Configuration of toner>
The toner used in the present invention contains toner particles containing a binder resin, a colorant and a release agent, and silica fine particles.

  Examples of the binder resin used in the toner of the present invention include polystyrene; homopolymers of styrene substitution products such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymers and styrene-vinyltoluene copolymers. Polymer, styrene-vinyl naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Styrenes such as methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Copolymer; Acrylic resin; Meta Lil resins; polyvinyl acetate; silicone resins; polyester resins; polyamide resin; furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.

  The comonomer for the styrene monomer of the styrene copolymer includes acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, doditer acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methacrylic acid. Monocarboxylic acid having a double bond such as methyl acid, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a substituted product thereof; maleic acid, butyl maleate, methyl maleate, maleate Dicarboxylic acids having a double bond such as dimethyl acid and its substitutes; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; Sulfonyl methyl ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

  The toner particles constituting the toner of the present invention can be produced by any of conventional pulverization methods, suspension polymerization methods, emulsion polymerization aggregation methods, and dissolution suspension methods.

  As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p A styrene derivative such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl accelerator Acrylic polymerizable monomers such as N-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Body; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n- Octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl meta Methacrylic polymerizable monomers such as relate and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinylmethyl And vinyl ethers such as ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, Examples include 2,2′-bis (4- (methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

  In the present invention, the above-described monofunctional polymerizable monomers are used alone or in combination of two or more, or the above-mentioned monofunctional polymerizable monomers and polyfunctional polymerizable monomers are used in combination. . The polyfunctional polymerizable monomer can also be used as a crosslinking agent.

  In the toner of the present invention, a crosslinking agent may be used for the purpose of increasing the mechanical strength of the toner.

  Examples of the bifunctional crosslinking agent include the following. Bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol Diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate , Polyester type diacrylate (MANDA Nippon Kayaku), and dimethacrylate replaced with dimethacrylate.

  The following are mentioned as a polyfunctional crosslinking agent. Pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, diallyl phthalate, tri Allyl cyanurate, triallyl isocyanurate and triallyl trimellitate.

  The addition amount of these crosslinking agents is preferably 0.001 to 1.000 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  The following are mentioned as a polymerization initiator used when manufacturing the toner of this invention with a polymerization method. 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis Azo or diazo polymerization initiators such as -4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl Peroxide-based polymerization initiators such as peroxide, lauroyl peroxide, tert-butyl-peroxypivalate.

  The amount of these polymerization initiators used is generally 3 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. The kind of the polymerization initiator is slightly different depending on the polymerization method, but is selected with reference to the 10-hour half-life temperature and used alone or in combination.

  In the present invention, in order to control the degree of polymerization of the polymerizable monomer, a known chain transfer agent, polymerization inhibitor or the like can be further added and used.

  When the toner of the present invention is produced by a polymerization method using an aqueous medium, it is preferable to add a polar resin in addition to the binder resin as the main component. By adding the polar resin, a polar resin layer can be provided on the surface of the toner particles, and the fastness of the toner particles can be improved without impairing the fixing property.

  Examples of the polar resin include polyester resin, epoxy resin, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, and styrene-maleic acid copolymer. A preferable addition amount of the polar resin is 1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Examples of the colorant used in the present invention include the following organic pigments or dyes, and inorganic pigments.

  As the organic pigment or organic dye as the cyan colorant, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, or a basic dye lake compound can be used.

  Specific examples include the following. C. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

  Examples of the organic pigment or organic dye as the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds.

  Specific examples include the following. C. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254, C.I. I. Pigment violet 19.

  As the organic pigment or organic dye as the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used.

  Specific examples include the following. C. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 191, 194.

  As the black colorant, carbon black and carbon black that is toned in black using the yellow / magenta / cyan colorant are used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner.

  The colorant is preferably used by adding 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  Examples of the release agent that can be used in the toner of the present invention include the following. Petroleum waxes and derivatives thereof such as paraffin wax, microcrystalline wax, petrolactam; montan wax and derivatives thereof; hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method; polyolefin waxes and derivatives thereof such as polyethylene wax and polypropylene wax; carnauba wax Natural waxes such as candelilla wax and derivatives thereof. These derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, and animal waxes. Among these, ester wax and hydrocarbon wax are preferable from the viewpoint of excellent releasability.

  The release agent used in the present invention has an endothermic peak derived from the release agent at a temperature of 60 ° C. or more and 120 ° C. or less in a DSC curve measured by a differential scanning calorimeter (DSC). It is preferable from the viewpoint of achieving both stability.

  The release agent is preferably contained in an amount of 0.5 to 30 parts by mass, preferably 3 to 20 parts by mass with respect to 100 parts by mass of the binder resin. More preferably, it is 5-15 mass parts. If content of a mold release agent is in said range, low temperature offset can be suppressed favorably, maintaining a long-term preservability. Also, good fluidity and image characteristics can be maintained without disturbing the dispersion of other toner materials.

  In the toner of the present invention, a charge control agent can be mixed with toner particles and used as necessary. As the charge control agent, known ones can be used, and examples of the toner that controls the toner to be negatively charged include the following. Organic metal compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, and phenol derivatives such as bisphenol. Further examples include urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, and resin charge control agents.

  Examples of controlling the toner to be positively charged include the following. Guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts thereof, and their Lake pigments; triphenylmethane dyes and these lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide); Metal salt of higher fatty acid; resin charge control agent.

  The toner of the present invention can contain these charge control agents alone or in combination of two or more.

The toner used in the present invention further satisfies the following relational expressions (1) and (2).
300 (mJ) ≦ E ≦ 450 (mJ) (1)
1.00 ≦ Ec / E ≦ 2.30 (2)
In the above formulas (1) and (2),
E is a powder fluidity analyzer that allows the peripheral speed of the outermost edge of the propeller blade to rotate at 100 mm / s while vertically entering the toner powder layer in the container, and 100 mm from the bottom of the powder layer. Start the measurement from the position. And the total (mJ) of rotational torque and a vertical load obtained when making it approach to the position of 10 mm from a bottom face is shown.

  Ec represents the total (mJ) of the rotational torque and the vertical load measured in the manner of measuring E in the toner powder layer to which a load of 3 kPa is applied.

  As a result of intensive studies, the present inventors have found the following in the intermediate transfer belt having the above characteristics. In other words, good transfer characteristics are obtained and the cleaning blade wear is prolonged by using toner in which the sum of the rotational torque and vertical load (total energy) measured by the powder flowability analyzer is controlled within a certain range. It was found that the period can be suppressed.

  By using a toner whose E value is controlled to a high fluidity of 300 (mJ) or more and 450 (mJ) or less, the transfer efficiency is effectively improved in the intermediate transfer belt of the present invention having surface characteristics with low in-plane average roughness. Can be increased.

  The value of Ec indicates the powder characteristics when a load of 3 kPa is applied to the toner. Ec / E represents the degree of change in fluidity with respect to toner pressure. A toner having an Ec / E value close to 1 means a characteristic that is easily unpacked or difficult to pack. The value of Ec / E was found to correlate with the degree of toner deterioration at the end of repeated printing (end of durability). Toner deterioration means a phenomenon in which inorganic fine particles externally added to toner particles for the purpose of imparting fluidity are embedded in toner particles due to agitation stress received in a developing device during durability.

  Further, according to the study by the present inventors, it has been found that there is a correlation between the toner deterioration and the wear state of the cleaning blade of the intermediate transfer belt used in the present invention. The present inventors consider that the reason is as follows. That is, it is considered that the cleaning blade is imparted with lubricity and the blade wear is suppressed when the external additive enters the nip portion with the intermediate transfer belt. Observing the blade nip, of course, there is no room for the residual toner to slip through the nip, but when observing the damped component on an enlarged scale, a small particle size is found upstream of the nip. And then a large particle size external additive is present as a blocking layer. Subsequently, there are toners having a small particle size and toners having a large particle size. It is already known that the formation of the blocking layer of the external additive is indispensable for the cleaning stability, but the cutting-edge external additive of the blocking layer partially penetrates into the nip portion by driving the belt. It was observed.

  When the toner deteriorates, the external additive is embedded, so that the amount of the external additive released in the transferred toner component is reduced, the lubricity of the blade is impaired, and wear progresses. Therefore, if toner deterioration can be suppressed through durability, it is considered that the external additive released to the blade nip can be stably supplied, and blade wear can be more effectively suppressed.

  In the present invention, the use of the toner whose Ec / E value is controlled to 1.00 or more and 2.30 or less enables the stirring torque in the developing device to be kept low throughout the durability. Sex can be further suppressed.

  Examples of the method for controlling the values of E and Ec include a method of controlling the selection according to selection of the type of silica particles added to the toner particles, adjustment of the formulation, addition amount, and addition conditions.

  As a preferable control method, a method of adding silica fine particles having a small particle diameter in which the number average particle diameter of primary particles is 4 to 20 nm is preferable. Further, titanium oxide fine particles having a primary particle number average particle size of 50 nm or less may be added.

The silica fine particles used in the present invention are preferably produced by subjecting the silica raw material to a hydrophobic treatment with silicone oil and a silane compound and / or silazane compound. Furthermore, those treated with silicone oil are preferable because they have a high lubricant effect at the blade nip portion. The titanium oxide fine particles are also preferably treated with silicone oil.
Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil. The treatment amount of the silicone oil at that time is preferably 5 to 40 parts by mass with respect to 100 parts by mass of the silica fine particles.

  Silane compounds include alkoxysilanes such as methoxysilane, ethoxysilane, and propoxysilane, halosilanes such as chlorosilane, bromosilane, and iodosilane, hydrosilanes, alkylsilanes, arylsilanes, vinylsilanes, acrylic silanes, and epoxysilanes. , Silyl compounds, siloxanes, silylureas, silylacetamides, and silane compounds having different substituents of these silane compounds at the same time.

  A silazane compound is a general term for compounds having a Si-N bond in the molecule. Specifically, dimethyldisilazane, trimethyldisilazane, tetramethyldisilazane, pentamethyldisilazane, hexamethyldisilazane, octamethyltrisilazane, hexamethylcyclotrisilazane, tetraethyltetramethylcyclotetrasilazane, tetraphenyldimethyldi Examples include silazane, dipropyltetramethyldisilazane, dibutyltetramethyldisilazane, dihexyltetramethyldisilazane, dioctyltetramethyldisilazane, diphenyltetramethyldisilazane, octamethylcyclotetrasilazane, and the like.

  As the silica base, both so-called dry process or dry silica called fumed silica produced by vapor phase oxidation of silicon halide, and so-called wet silica produced from water glass or the like can be used. . The silica fine particles used in the present invention are preferably those that have been crushed during or after the hydrophobization treatment step. Further, when the hydrophobizing treatment is performed in two stages, it is possible to perform the crushing treatment between the hydrophobizing treatment steps.

  The hydrophobic treatment with silicone oil and the hydrophobic treatment with silane compound and / or silazane compound may be either dry treatment or wet treatment.

  The specific procedure for the hydrophobic treatment with silicone oil is, for example, by reacting silica fine particles in a solvent in which silicone oil is dissolved (preferably a solvent adjusted to pH 4 with an organic acid or the like), and then removing the solvent. To do. Thereafter, a crushing process may be performed. Subsequently, when performing a hydrophobization treatment with a silane compound and / or a silazane compound, the specific procedure is to put the crushed silicone oil-treated silica fine particles into a solvent in which these are dissolved and to react. Thereafter, the solvent is removed and a crushing treatment is performed. Further, the following method may be used. For example, in the hydrophobic treatment with silicone oil, silica fine particles are placed in a reaction vessel. Then, alcohol water is added with stirring in a nitrogen atmosphere, silicone oil is introduced into the reaction vessel to perform a hydrophobization treatment, and the mixture is further heated and stirred to remove the solvent, followed by pulverization treatment. In the hydrophobization treatment with a silane compound and / or a silazane compound, the silane compound and / or the silazane compound is introduced and the hydrophobization treatment is performed with stirring in a nitrogen atmosphere. . In the silica fine particles used in the present invention, it is one of preferred embodiments that both the hydrophobization treatment of the silicone oil and the hydrophobization treatment with the silane compound and / or the silazane compound are performed. You may go first.

  In the hydrophobic treatment with the silicone oil, it is preferable to chemically fix the silicone oil to the surface of the silica base. Therefore, it is preferable to perform a heat treatment in order to chemically fix it. The heating temperature is preferably 100 ° C. or higher, and the higher the heating temperature, the more preferable. This heat treatment step is preferably performed immediately after the silicone oil treatment, but when the crushing treatment is performed, the heat treatment step may be performed after the crushing treatment step.

  The toner of the present invention preferably contains silica fine particles of 0.40 parts by mass or more and 2.00 parts by mass or less per 100 parts by mass of the toner particles.

<Measurement method of E and Ec>
E and Ec in the present invention are measured by using “powder fluidity analyzer powder rheometer FT4” (manufactured by Freeman Technology, hereinafter may be abbreviated as FT4). Specifically, the measurement is performed by the following operation.

  In all operations, a 48 mm-diameter blade dedicated to FT4 (see FIG. 7, model number: C210, material: SUS, hereinafter may be abbreviated as “blade”) is used as the propeller blade. This propeller blade has a rotation axis in the normal direction at the center of a blade plate of 48 mm × 10 mm. The blade plate is smoothly twisted counterclockwise so that both outermost edge portions (24 mm from the rotating shaft) are 70 ° and a portion 12 mm from the rotating shaft is 35 °.

  As the measurement container, a cylindrical split container dedicated to FT4 (model number: C203, material: glass, diameter 50 mm, volume 160 ml, height 82 mm from the bottom surface to the split part, hereinafter may be abbreviated as container) is used. . In addition, 100 g of toner left in an environment of a temperature of 23 ° C. and a humidity of 60% RH for 3 days or more is put in the measurement container to form a toner powder layer.

(1) Conditioning operation (a) The propeller blade is rotated clockwise with respect to the powder layer surface so that the peripheral speed of the outermost edge of the blade is 60 mm / sec (the powder layer is loosened by the rotation of the blade). Direction). The surface of the powder layer at an approach speed at which the angle between the locus drawn by the outermost edge of the moving blade and the surface of the powder layer (hereinafter sometimes referred to as the angle formed) is 5 °. From the bottom surface of the toner powder layer to the position of 10 mm in the vertical direction. Thereafter, the toner powder layer is rotated while rotating clockwise with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the blade is 60 mm / sec. The blade is advanced to a position of 1 mm from the bottom surface. Further, while rotating clockwise with respect to the powder layer surface so that the angle formed is 5 ° and the peripheral speed of the outermost edge of the blade is 60 mm / sec, 100 mm from the bottom surface of the toner powder layer. Move the blade to position and remove it. When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.
(B) The operations (1) to (a) are repeated five times to remove the air taken in the toner powder layer.

(2) Compression operation When measuring Ec, the toner powder layer subjected to the conditioning operation in (1) is compressed by applying a pressure of 3 kPa. Specifically, a compression test piston (diameter 48 mm, height 20 mm, lower mesh tension) is mounted instead of the propeller blade. The piston is lowered at 0.1 mm / s to compress the toner. When the load on the piston reaches 3 kPa, the descent is stopped and held for 60 seconds to form a compressed powder layer.

(3) Split operation The conditioned powder layer or compressed powder layer is cut off at the split portion of the FT4 container described above, and the toner on the upper part of the powder layer is removed. By this operation, the volume of the toner powder layer can be made the same for each measurement.

(4) Measurement operation (i) E measurement (a) Conditioning operation similar to (1)-(a) is performed once.
(B) Rotate the propeller blade counterclockwise with respect to the powder layer surface (direction in which the powder layer is pushed in by rotation of the blade) so that the peripheral speed of the outermost edge of the blade is 100 mm / sec. To do. The blade is advanced in the vertical direction from the powder layer surface to a position 10 mm from the bottom surface of the toner powder layer at an approach speed of 5 °. Thereafter, the blade rotates clockwise with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the blade is 60 mm / sec, and the angle forming the vertical entry speed to the powder layer becomes 2 °. It is made to approach to the position of 1 mm from the bottom face of the powder layer at the approach speed. Further, the blade is moved to a position of 100 mm from the bottom surface of the powder layer at a speed of 5 °, and is extracted. When the extraction is completed, the toner attached to the blade is wiped off by rotating the blade alternately in small clockwise and counterclockwise directions.
(C) The operations of (4)-(i)-(b) are further repeated 6 times, and the rotation obtained when the blade enters the position from 100 mm to 10 mm from the bottom of the toner powder layer at the sixth time. E is the sum of torque and vertical load.
(Ii) Measurement of Ec The operation of (4)-(i)-(b) is similarly performed on the compressed powder layer, and the blade is advanced from the position of 100 mm to the position of 10 mm from the bottom of the toner powder layer. Ec is the sum of the rotational torque and vertical load obtained at the time.

<Number average particle diameter of silica fine particles>
Measurement of the average primary particle size of silica fine particles contained in the toner is 100,000 times by adding 1 part by mass of silica fine particles to 100 parts by mass of toner particles using FE-SEM S-4800 (manufactured by Hitachi, Ltd.). Take a photo of the enlarged toner particle surface. Using the enlarged photograph, the particle size of 100 or more silica fine particles is measured and obtained from the arithmetic average. The particle diameter of the silica fine particles is counted as the absolute maximum length when the shape is spherical, and the major axis is counted as the particle diameter when it has a major axis and a minor axis.

<Method for Measuring Toner Weight Average Particle Size (D4)>
The weight average particle diameter (D4) of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOMME)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution is put in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rotations / second. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetra 150” (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . The measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

  Hereinafter, the present invention will be described in detail by way of examples and comparative examples. First, toner production examples used in Examples and Comparative Examples of the present invention will be described. Unless otherwise specified, all parts and% in the examples and comparative examples are based on mass.

<Production Example of Toner Particle (1)>
Toner particles 1 were produced by the suspension polymerization method as follows. The following materials were mixed and stirred for 2 hours to dissolve the polar resin to obtain a polar resin-containing monomer composition.
-Styrene 34.0 parts-N-butyl acrylate 30.0 parts-Polar resin saturated polyester resin [produced from terephthalic acid and PO-modified bisphenol A: Mp = 9000, Tg = 72 ° C., acid value = 12.0 mgKOH / g ] 5.0 parts ・ Charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 1.0 parts In addition, the following materials are mixed together with zirconia beads (3/16 inch) in an attritor (manufactured by Mitsui Mining). The mixture was stirred at 200 rpm for 3 hours, and the beads were separated to obtain a colorant dispersion.
-Styrene 36.0 parts-Colorant C.I. I. Pigment Blue 15: 3 6.0 parts Next, the following materials were mixed.
-Polar resin-containing monomer composition 70.0 parts-Colorant dispersion 42.0 parts Subsequently, the mixture was heated to 60 ° C, and 10.0 parts of wax (HNP-51: manufactured by Nippon Seiwa Co., Ltd.) ) Was added. Next, 5.0 parts of a polymerization initiator perbutyl O (manufactured by NOF Corporation) was added and stirred for 5 minutes.

On the other hand, 875 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution and 8.0 parts of 10 mass% hydrochloric acid were added to a container equipped with a high-speed stirring device Claremix (M Technique Co., Ltd.), and the rotation speed was 15000 rpm. And heated to 60 ° C. To this, 70 parts of a 1.0 mol / L-CaCl ₂ aqueous solution was added to prepare an aqueous medium containing a minute hardly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ . 5 minutes after the polymerization initiator is charged into the polymerizable monomer composition, the polysynthetic monomer composition at 60 ° C. is charged into an aqueous medium heated to 60 ° C., and the CLEARMIX is rotated at 15000 rpm. And granulated for 15 minutes. Thereafter, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and the mixture was reacted at 60 ° C. for 5 hours while refluxing. The liquid temperature was then adjusted to 80 ° C., and the mixture was further reacted for 5 hours. After completion of the polymerization, the liquid temperature was lowered to about 20 ° C., diluted hydrochloric acid was added to adjust the pH of the aqueous medium to 3.0 or less, and the poorly water-soluble dispersant was dissolved. Further, washing and drying were performed to obtain toner particles 1 (toner particles before processing the external additive) having a weight average particle diameter (D4) of 6.0 μm.

<Production Example of Silica Fine Particle 1>
As a first treatment step, 10.0 parts of dimethyl silicone with respect to 100 parts of fumed silica (trade name AEROSIL 380S, specific surface area 380 m ² / g by BET method, number average diameter of primary particles 7 nm, manufactured by Nippon Aerosil Co., Ltd.) Oil was sprayed, and silicone oil treatment was performed in a fluidized state of silica. Thereafter, the temperature was raised to 300 ° C. with stirring, and the mixture was further stirred for 2 hours, whereby dimethyl silicone oil was baked on the fumed silica surface to complete the reaction.

  As the second treatment step, 30.0 parts of hexamethyldisilazane (hereinafter also referred to as HMDS) is sprayed on the silica fine particles produced in the first treatment step, and the silane compound treatment is performed in a fluidized state of silica. It was. This reaction was continued for 60 minutes, and then the reaction was terminated.

<Example of production of silica fine particles 2>
In the production example of silica fine particles 1, silica fine particles 2 were obtained in the same manner except that the first treatment step was changed to HMDS treatment and the second treatment step was changed to silicone oil treatment.

<Example of production of silica fine particles 3>
In the production example of silica fine particles 2, the same is performed except that the fumed silica used is changed to (trade name AEROSIL200, specific surface area 200 m ² / g by BET method, number average diameter of primary particles 12 nm, manufactured by Nippon Aerosil Co., Ltd.). Thus, silica fine particles 3 were obtained.

<Example of production of titanium oxide fine particles 1>
As a first treatment step, 10.0 parts of isobutyltrimethoxysilane are sprayed inside with respect to 100 parts of titanium oxide fine particles (trade name MT-150A, manufactured by Teika Co., Ltd.) having a number average diameter of 15 nm of primary particles. The silane compound treatment was performed in a fluidized state of titanium. This reaction was continued for 60 minutes, and then the reaction was terminated.

  As the second treatment step, 10.0 parts of dimethyl silicone oil was sprayed on the titanium fine particles produced in the first treatment step, and stirring was continued for 30 minutes. Thereafter, the temperature was raised to 190 ° C. while stirring, and the mixture was further stirred for 3 hours, whereby dimethyl silicone oil was baked on the titanium oxide surface to complete the reaction. Thereafter, crushing treatment was repeatedly performed with a jet mill until the aggregate of titanium oxide disappeared, and titanium oxide fine particles 1 were obtained.

<Production Example of Toner 1>
Silica fine particles 1: 0.8 parts and titanium oxide fine particles 1: 0.8 parts are added to toner particles 1: 100.0 parts and mixed for 10 minutes at 4000 rpm using a Henschel mixer (Mitsui Mining Co., Ltd.). Thus, toner 1 was obtained.

  Toner 1 had a weight average particle diameter (D4) of 6.0 μm, E of 400 mJ, and Ec / E of 1.90. Table 1 shows the physical properties of Toner 1.

<Production example of toner 2 to toner 5>
In the toner 1 production example, toners 2 to 5 were obtained in the same manner as in the toner 1 production example, except that the types and addition amounts of silica fine particles and titanium oxide fine particles added were changed to those shown in Table 1. . In Toner 5, no titanium oxide fine particles were added. Table 1 shows the physical properties of Toner 2 to Toner 5.

Example 1
In Example 1, the intermediate transfer belt 13 including the base layer 102 and the surface layer 101 was used. A method for manufacturing the intermediate transfer belt 13 will be described below.

<Preparation of base layer>
First, a method for manufacturing the base layer 101 will be described. A bottle-shaped molded body was obtained by blow-molding a polyethylene naphthalate resin, and an endless belt body was obtained by cutting this with an ultrasonic cutter. In the polyethylene naphthalate resin, carbon black is dispersed as a resistance adjusting agent. The polyethylene naphthalate resin belt having a thickness of 70 μm thus obtained was used as the base layer 101 of the intermediate transfer belt 13.

<Preparation of surface layer forming coating solution>
Next, a method for producing a coating solution for forming the surface layer will be described. In a container shielded from ultraviolet rays,
Sliding property particles: PTFE particles having a particle size of 200 nm,
Lucifal (trade name, manufactured by Nippon Paint Co., Ltd.), which is an acrylic ultraviolet curable hard coat material containing pentaerythritol triacrylate and pentaerythritol tetraacrylate, was mixed. Fluorine-based graft polymer GF400 (trade name, manufactured by Toagosei Co., Ltd.) and methyl isobutyl ketone were added thereto as a dispersant for PTFE particles, and coarse dispersion was performed by processing with a high-speed shearing disperser (homogenizer). .

  Thereafter, the liquid subjected to the rough dispersion treatment was subjected to the main dispersion treatment using a high-pressure emulsification disperser (Nanobeta: manufactured by Yoshida Kikai Kogyo Co., Ltd.). Further, the liquid after the final dispersion treatment of PTFE was dropped while stirring the liquid in which amine having a low molecular weight was added as a dispersing agent to Cellax (trade name, 210IP: manufactured by Nissan Chemical Industries, Ltd.) as conductive particles. A coating solution for forming the surface layer was obtained.

<Preparation of intermediate transfer belt with surface layer>
Next, a method for forming a surface layer on the base layer will be described. On the base layer for the intermediate transfer belt, a coating for forming the surface layer was dip-coated in a coating environment at a temperature of 25 ° C. and a relative humidity of 60%. Then, after 10 seconds from the end of the coating, ultraviolet rays are irradiated using an ultraviolet irradiation device (trade name: UE06 / 81-3, manufactured by Eye Graphic Co., Ltd., integrated light quantity: 1000 mJ / cm ² ) in the same place as the coating environment. The surface layer 102 was cured. As a result, a cured resin film having a thickness of 3 μm was formed, and this cured resin film was used as the intermediate transfer belt surface layer 102. Thus, the intermediate transfer belt 13 having the surface layer 102 was produced.

Next, a groove shape 110 was formed on the surface layer 102 of the intermediate transfer belt obtained by the above method. The intermediate transfer belt 13 is elastically deformed and attached to a cylinder having an outer diameter slightly larger than the inner diameter of the intermediate transfer belt 13. Then, a lapping film (Lapika # 2000 (trade name), manufactured by KOVAX Co., Ltd.) using aluminum oxide having a grain size of 9 μm as an abrasive is brought into contact with the surface of the intermediate transfer belt mounted on the cylinder at a surface pressure of 1.96 N / mm ^2. The cylinder was rotated for 40 seconds. As a result, an intermediate transfer belt 13 having a groove shape 110 having a groove width 111 of 2 μm and a groove depth 112 of 1 μm formed on the surface layer 102 was obtained.

<Surface observation evaluation 1>
The in-plane average roughness of the surface layer 102 was measured in the four observation fields (average toner particle diameter) of the surface layer 102 of the produced intermediate transfer belt 13. A scanning probe microscope (SPI3800: manufactured by SII Nanotechnology Inc.) was used for the measurement. The cantilever was made of silicone and had a tip radius of 15 nm or less, a spring constant of 15 N / m, and a resonance frequency of 136 KHz. As the measurement mode, a dynamic force mode capable of obtaining a highly accurate image in nano order without destroying the sample was used. The measurement frequency was 0.3 to 1.0 Hz. The visual field of observation was determined from the average particle diameter of the toner obtained from the measurement of the average particle diameter of the toner, and in this example, the in-plane average roughness of the surface layer 102 in a 6 μm square was measured. The in-plane average roughness of the surface layer 102 was measured as an average value at 10 arbitrary positions that do not overlap.

<Surface observation evaluation 2>
The ten-point average roughness Rzjis on the surface layer 102 of the produced intermediate transfer belt 13 was measured under the following conditions. Using a surface roughness / contour shape measuring device Surfcom 1500SD (manufactured by Tokyo Seimitsu), measurement was performed at a cutoff wavelength of 0.25 mm, a measurement reference length of 0.25 mm, and a measurement length of 1.25 mm in accordance with the standard JIS B0601: 2001. . For the ten-point average roughness Rzjis of the surface layer 102, the stylus of the measuring device was scanned in a direction orthogonal to the rotational driving direction of the intermediate transfer belt 13, and an average value of at least five arbitrary points was used as a measurement result.

<Surface observation evaluation 3>
The contact area ratio in the surface layer 102 of the produced intermediate transfer belt 13 was measured using a confocal microscope (OPTELICS, manufactured by Lasertec Corporation). The observation area was 100 μm square, the measurement wavelength was 546 nm, the scan frequency in the thickness direction of the intermediate transfer belt was 0.2 μm, and the surface layer thickness was 3 μm. The contact area ratio is calculated for the obtained surface shape by the following method.

A threshold is provided on the base layer side of 0.3 μm from the outermost surface portion of the measurement region, a contact region is defined as less than 0.3 μm from the outermost surface, and a non-contact region is defined as 0.3 μm or more from the outermost surface.
Contact area ratio% = (area of contact area / area of observation area) × 100. The average value of at least 5 arbitrary places was made into the measurement result by the said method.

  This value is the contact area between the surface of the intermediate transfer belt 13 and the cleaning blade 29 with respect to the total surface area of the intermediate transfer belt 13 within the range of the cleaning blade 29 in the direction orthogonal to the moving direction of the surface of the intermediate transfer belt 13. The percentage can be represented.

<Evaluation of transfer efficiency>
The produced intermediate transfer belt 13 and toner 1 were mounted on the image forming apparatus shown in FIG. 2 and the transfer efficiency was evaluated. The toner 1 was evaluated by filling the toner containers 5 of all process cartridges indicated by YMCK shown in FIG.

As for the image pattern, a solid image is overlaid from each station of YMC, the amount of toner per unit area on the intermediate transfer belt is 1.3 mg / cm ^2, and the secondary transfer bias is optimum for the transfer material S. Transfer efficiency was calculated from the amount of toner before and after transfer. The transfer efficiency was evaluated using a 25% COTTON CONTENT (trade name) transfer material having a basis weight of 90 g / m ² under an environment of a temperature of 25 ° C. and a relative humidity of 50%. At this time, when the transfer efficiency was less than 94%, an image defect (toner granularity, white spots) of a level that could be visually confirmed occurred.

<Evaluation of cleaning durability>
In order to investigate the durability of the cleaning performance of the image forming apparatus, a paper passing durability evaluation was performed using the color image forming apparatus of FIG. The produced intermediate transfer belt 13 was used, and the toner was evaluated by filling toner 1 in all YMCK cartridges.

In an environment where the temperature is 25 ° C and the relative humidity is 50%, OCE Extra grammage 80g / m ² , A4 paper is used to intermittently print 2 sheets of 1% printing image, and poorly cleaned. The occurrence of was confirmed. In the cleaning evaluation method, the secondary transfer voltage is set to an appropriate value after a secondary color image (Y, M station toner) is printed on the entire surface of the A4 size with the secondary transfer voltage turned off (0 V). The paper is continuously passed in a blank sheet state. By doing so, the toner of the Y and M stations that is hardly transferred to the transfer material S at the secondary transfer portion enters the cleaning blade. If they can be cleaned, the three sheets to be passed after that are output in a completely blank state, but if they cannot be cleaned, the toner that has passed through the cleaning blade is transferred onto the white paper and output as a poorly cleaned image. . The evaluation as described above was performed for every 10,000 sheets passed, and “A” was indicated when cleaning was completed after 100,000 sheets were passed, and “B” was indicated otherwise. The toner was replenished by replacing the process cartridge every time the printing became thinner. Table 2 shows the performance evaluation results of Examples and Comparative Examples.

(Example 2)
In Example 2, the groove depth 112 is made larger than that in Example 1, the intermediate transfer belt 13 in which the groove shape 110 having a groove width 111 of 2 μm and a groove depth of 1.5 μm is formed is used. The performance was confirmed. The intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the contact time of the wrapping film with the intermediate transfer belt when forming the groove shape 110 on the surface layer 102 was set to 80 sec. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Examples 3 to 5)
In Examples 3 to 5, the evaluation was performed in the same manner as in Example 2 except that the toner used in Example 2 was changed to toners 2 to 4. Table 2 shows the toner used in each example, the transfer efficiency evaluation, and the cleaning durability evaluation results.

(Example 6)
In Example 6, the transfer efficiency and cleaning performance were confirmed using the intermediate transfer belt 13 in which the groove width 111 was made smaller than that in Example 1, and the groove shape 110 having a groove width 111 of 1 μm and a groove depth of 1 μm was formed. did. The intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the pressing force of the wrapping film when forming the groove shape 110 on the surface layer 102 was 0.98 N / mm ² . Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Example 7)
In Example 7, the transfer efficiency and cleaning performance of the intermediate transfer belt 13 in which the groove width 111 is larger than that in Example 1, and the groove shape 110 having the groove width 111 of 2.5 μm and the groove depth of 1 μm is formed. confirmed. An intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the pressing force of the wrapping film when forming the groove shape 110 on the surface layer 102 was a surface pressure of 3.92 N / mm ² . Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Example 8)
In Example 8, the intermediate transfer belt 13 in which the groove width 111 and the groove depth 112 are made larger than in Example 1, the groove shape 110 having a groove width 111 of 2.5 μm and a groove depth of 2 μm is formed, is used. The transfer efficiency and cleaning performance were confirmed. An intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the abrasive grain size of the wrapping film when forming the groove shape 110 on the surface layer 102 was 12 μm. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Comparative Example 1)
In Comparative Example 1, the transfer efficiency and cleaning performance were confirmed using the intermediate transfer belt 13 in which the groove shape 110 is not formed on the surface layer 102 of the intermediate transfer belt. An intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the groove shape 110 by lapping was not formed after the surface layer 102 was formed. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Comparative Example 2)
In Comparative Example 2, toner 5 having a larger Ec / E value than toner 4 was used. Further, the groove shape 110 is made smaller than the belt used in Example 6, and the intermediate transfer belt 13 having the groove shape 110 having a groove width 111 of 0.5 μm and a groove depth of 0.3 μm is used. Efficiency and cleaning performance were confirmed. After forming the surface layer 102, an intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1 except that the abrasive grain size of the wrapping film when forming the groove shape 110 on the surface layer 102 of the intermediate transfer belt was changed to 5 μm. . Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Comparative Example 3)
In Comparative Example 3, the groove shape 110 is made larger than that in Example 8, the intermediate transfer belt 13 in which the groove shape 110 having a groove width 111 of 4 μm and a groove depth of 2.5 μm is formed is used. The performance was confirmed. After forming the surface layer 102, the abrasive grain size of the wrapping film when forming the groove shape 110 on the surface layer 102 of the intermediate transfer belt was 12 μm, and the contact time of the wrapping film with the intermediate transfer belt was 80 seconds. Otherwise, the intermediate transfer belt 13 having the surface layer 102 was obtained in the same manner as in Example 1. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Comparative Example 4)
In Comparative Example 4, the transfer efficiency and the cleaning performance were confirmed using the intermediate transfer belt 13 in which a filler was added to the intermediate transfer belt surface layer 102 to give a random uneven shape. When preparing the surface layer forming coating solution, 50 parts by weight of styrene / acrylic resin fine particles (Fineware: Nippon Paint Co., Ltd.) having a particle diameter of 1 μm were added for the purpose of imparting a shape to the surface layer 102. Otherwise, an intermediate transfer belt 13 having a surface layer 102 was obtained in the same manner as in Comparative Example 1. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

(Comparative Example 5)
In Comparative Example 5, transfer efficiency and cleaning performance were confirmed using an intermediate transfer belt 13 to which a filler having a larger particle diameter than that of Comparative Example 4 was added to give a random uneven shape. At the time of preparing the surface layer forming coating solution, 50 parts by weight of melamine silica resin particles having a particle size of 2 μm (Opto Beads: manufactured by Nissan Chemical Industries, Ltd.) were added for the purpose of imparting a shape to the surface layer 102. Otherwise, an intermediate transfer belt 13 having a surface layer 102 was obtained in the same manner as in Comparative Example 1. Table 2 shows the results of evaluation of transfer efficiency and evaluation of cleaning durability.

  From the above evaluation results, in order to obtain a transfer efficiency of 94% or more, it is necessary from the results of Example 8, Comparative Example 3 and Comparative Example 5 that the 6 μm square average roughness is 30 nm or less. Next, from the results of Example 8 and Comparative Example 4, the surface layer shape for satisfying the cleaning durability is not a random uneven shape, but a groove shape intersecting with the cleaning blade is required.

1 (1a, 1b, 1c, 1d) Photosensitive drum 8 (8a, 8b, 8c, 8d) Development unit 9 (9a, 9b, 9c, 9d) Process cartridge 10 (10a, 10b, 10c, 10d) Primary transfer roller 13 Intermediate transfer belt 14 Driving roller 15 Tension roller 19 Fixing means 25 Secondary transfer roller 27 Cleaning means 28 Cleaning blade 101 Intermediate transfer belt base layer 102 Intermediate transfer belt surface layer 103 Acrylic resin 104 PTFE particles

Claims (10)

A charging step of charging the image bearing member with a charging means;
An exposure step of exposing the charged image carrier to form an electrostatic latent image;
A developing step of developing the electrostatic latent image with toner to form a toner image on the image carrier;
A transfer step of transferring the toner image to a transfer material via an intermediate transfer belt;
A fixing step of fixing a toner image on the transfer material, and a cleaning step of removing residual transfer toner remaining on the intermediate transfer belt with a cleaning blade;
An image forming method comprising:
The surface of the intermediate transfer belt has a groove shape in a direction crossing the cleaning blade, and the width of the groove shape is less than half of the weight average particle diameter (D4) of the toner;
In the toner with a weight average particle diameter of the four-way (D4μm × D4μm), plane average roughness of the surface of the intermediate transfer belt, and a 10nm or more 30nm or less,
The ten-point average roughness Rzjis of the surface of the intermediate transfer belt in the direction perpendicular to the rotation direction of the intermediate transfer belt is 0.26 μm or more and 0.67 μm or less,
The toner is
Toner particles containing a binder resin, a colorant, and a release agent;
Silica fine particles,
Containing
An image forming method , wherein the toner satisfies the following formulas (1) and (2).
300 (mJ) ≦ E ≦ 450 (mJ) (1)
1.00 ≦ Ec / E ≦ 2.30 (2)
(In the above formulas (1) and (2),
E is a powder flowability analyzer that allows the peripheral speed of the outermost edge of the propeller blade to rotate at 100 mm / s while vertically entering the toner powder layer in the container, and from the bottom surface of the toner powder layer. The sum (mJ) of rotational torque and vertical load obtained when measurement is started from a position of 100 mm and entered from the bottom to a position of 10 mm is shown.
Ec represents the sum (mJ) of the rotational torque and the vertical load measured in the manner of measuring E in the toner powder layer given a load of 3 kPa. ) The image forming method according to claim 1, wherein a contact area ratio of the cleaning blade is 80% or more and 97% or less with respect to a total area of the surface of the intermediate transfer belt. The surface of the intermediate transfer belt, an image forming method according to 請 Motomeko 1 or 2 that is composed of an acrylic copolymer. The intermediate transfer belt is composed of two or more layers,
The image forming method according to claim 1, wherein the surface layer of the intermediate transfer belt contains a cured product of a composition containing a curable monomer and / or oligomer component.   The image forming method according to claim 4, wherein the surface layer of the intermediate transfer belt further contains fluorine-containing particles. The image forming method according to claim 5, wherein the fluorine-containing particles are polytetrafluoroethylene (PTFE).   The image forming method according to claim 1, wherein the toner further contains titanium oxide fine particles.   The image forming method according to claim 7, wherein the silica fine particles and the titanium oxide fine particles are treated with silicone oil. The image forming method according to claim 1, wherein the cleaning blade is a blade made of polyurethane rubber.   The image forming method according to claim 1, wherein the cleaning blade has a hardness of 70 degrees or more and 80 degrees or less in accordance with JIS K6253 standard.

Images