JP3236182B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system, and more particularly, to a method in which a toner image formed on a first image carrier is temporarily transferred onto an intermediate transfer member and then transferred to a second image carrier.
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, etc., which obtains an image-formed product by being further transferred onto an image carrier.

[0002]

2. Description of the Related Art An image forming apparatus using an intermediate transfer member includes:
A color image forming apparatus, a multi-color image forming apparatus, or a color image forming apparatus that sequentially transfers a plurality of component color images of color image information or multi-color image information and outputs an image formed product by combining and reproducing a color image or a multi-color image. The image forming apparatus is effective as an image forming apparatus having a forming function and a multicolor image forming function, and can obtain an image without overlapping deviation (color deviation) of each component color image.

A color electrophotographic apparatus having an image forming apparatus using the above-mentioned intermediate transfer member is a conventional technique in which a second image carrier is stuck or adsorbed on a transfer drum,
A color electrophotographic apparatus having an image forming apparatus for transferring an image thereon from a first image carrier, for example,
It is superior to the transfer method described in JP-A-301960 in the following points. That is, there is little color misregistration when the toner images of each color are superimposed. In addition, the second image carrier can be selected in various ways. For example,
From thin paper (40 g / m ² paper) to thick paper (200 g / m ²
Paper). Transfer is possible regardless of the width of the second image carrier or the length of the second image carrier. Further, it can be applied to envelopes, postcards, label paper, and the like.

In many cases, the intermediate transfer member is rarely used as a single layer, and it is general to use a multi-layer coating layer having separated functions. At this time, methods for forming the coating layer include melt molding, injection molding, dip coating and spray coating. Such a coating method has advantages that a continuous production of the intermediate transfer member is possible, a mold that can be produced at a relatively low cost, and a large molding device are not required.

[0005]

On the other hand, however, unevenness in the thickness of the coating layer in the coating process, poor dispersion of the paint components, unevenness in electric resistance and surface roughness and the like were liable to occur. Furthermore, unevenness in electric resistance due to uneven heating in the drying step of the coating layer, cracking and peeling of the coating, and the like were easily generated.

When these defects occur, the transfer efficiency decreases due to partial electric resistance unevenness, and the characters 110 shown in FIG.
When the image having the hollow portion 110a is repeatedly used as described above, the coating layer floats, and the portion is not energized, so that an image defect such as a ring-like or dotted white image is generated.

Further, when the intermediate transfer member is repeatedly used, so-called filming, in which toner that cannot be completely removed by the cleaner is deposited on the surface of the intermediate transfer member, may occur. When the filming occurred, it was difficult for the toner to be transferred from the first image carrier to the intermediate transfer member, and a white image was formed in a spot-like manner.

Several materials have been proposed as materials for the intermediate transfer material (for example, see Japanese Unexamined Patent Publication No.
No. 81786, JP-A-4-88385, JP-A-3-242667, JP-A-5-333725, etc.) are still insufficient.

The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus which can obtain a clear image by using an intermediate transfer member which is excellent in transfer efficiency and does not cause filming. I do.

[0010]

According to the present invention, there is provided an image forming apparatus comprising a coating layer containing a binder resin and high molecular weight polymer particles.
An intermediate transfer member having a coating layer formed by applying a coating material, and an image carrier for transferring an image to the intermediate transfer member, the binder resin in the coating material for the coating layer Solubility index SP1 and polymer weight in the coating material for the coating layer
The solubility index SP2 of the coalesced particles is | SP1-SP2 | ≦
4.

An example of the image forming apparatus of the present invention shown in FIG. 1 is an apparatus (copier or laser beam printer) for forming a color image, in which a medium-resistance roller 20 is used as an intermediate transfer member.

Reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) which is repeatedly used as a first image carrier, and rotates at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow. Driven.

In the course of rotation, the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential by a primary charger (corona discharger) 2 and then exposed to image exposure means (not shown) for color separation / combination of a color original image. An image exposure optical system, a scanning exposure system using a laser scanner that outputs a laser beam modulated in accordance with a time-series electric digital pixel signal of image information, etc.) to receive a first image of a target color image. An electrostatic latent image corresponding to a color component image (for example, a magenta component image) is formed.

Next, the electrostatic latent image is transferred to the first developing device 41.
(Magenta developing device) is developed with magenta toner M as the first color. At this time, the second to fourth developing devices 4
2, 43, and 44 (developing units for cyan, yellow, and black) are turned off and do not act on the photosensitive drum 1, and the magenta toner image of the first color is used for the second to fourth magenta toner images.
Of the developing units 42 to 44.

The intermediate transfer member 20 is driven to rotate at the same peripheral speed as the photosensitive drum 1 in the counterclockwise direction indicated by the arrow. The intermediate transfer member 20 includes a pipe-shaped core metal 100 serving as a support.
And a coating layer 101 formed on the outer peripheral surface thereof.

The above-mentioned first carrier formed and carried on the photosensitive drum 1
In the process in which the magenta toner image of the color passes through the nip portion between the photosensitive drum 1 and the intermediate transfer body 20, an outer peripheral surface of the intermediate transfer body 20 is generated by an electric field formed by a primary transfer bias applied to the intermediate transfer body 20. The intermediate transfer is sequentially performed.

After the transfer of the first color magenta toner image onto the intermediate transfer member 20, the surface of the photosensitive drum 1 is cleaned by the cleaning device 14.

Hereinafter, similarly, the cyan toner image of the second color,
The third color yellow toner image and the fourth color black toner image are sequentially superimposed and transferred onto the intermediate transfer body 20 to form a composite color toner image corresponding to the target color image.

Reference numeral 25 denotes a transfer roller, which is provided in parallel with the intermediate transfer member 20 and in contact with the lower surface thereof.

First transfer from the photosensitive drum 1 to the intermediate transfer member 20
The primary transfer bias for the sequential superimposition transfer of the toner images of the fourth to fourth colors has a polarity (+) opposite to that of the toner and has a bias power supply 61.
Is applied. The applied voltage is, for example, +2 kV to +5
kV range.

First transfer from the photosensitive drum 1 to the intermediate transfer member 20
The transfer roller 25 and the intermediate transfer member cleaner 35 can be separated from the intermediate transfer member 20 in the process of sequentially transferring the toner images of the fourth to fourth colors.

The transfer of the composite color toner image superimposed on the intermediate transfer member 20 to the transfer material 24 as the second image carrier is performed while the transfer roller 25 is in contact with the intermediate transfer member 20 and A recording material 24 such as paper is fed from the paper cassette 9 to a contact nip between the intermediate transfer body 20 and the transfer roller 25 at a predetermined timing, and at the same time, a secondary transfer bias is applied to the transfer roller 25 from a bias power supply 29. . With this secondary transfer bias, the composite color toner image is transferred from the intermediate transfer member 20 to the transfer material 24 as the second image carrier. The transfer material 24 that has received the toner image transfer is
5 and heat-fixed.

After the transfer of the image to the transfer material 24, the transfer residual toner on the intermediate transfer member 20 is cleaned by contacting the intermediate transfer member cleaner 35.

The intermediate transfer member used in the present invention has at least a first coating layer 101 on the outer peripheral surface of a core metal 100 as a support as shown in FIG. Or FIG. 3 or FIG.
As shown in FIG.
2, or the second coating layer 102 and the third coating layer 103
May be provided. In some cases, the intermediate transfer may be constituted only by the coating layer without using the support. At least one of the coating layers is an elastic layer formed of a binder resin containing polymer particles by melt molding, injection molding, dip coating, spray coating, or the like.

The binder resin used for the coating layer is preferably a rubber, an elastomer, or a resin. Examples of the elastomer or rubber include styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, and ethylene-propylene. Copolymers, nitrile butadiene rubber, chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, nitrile rubber, urethane rubber, acrylic rubber, epichlorohydrin rubber, norbornene rubber, and the like can be used. As resins, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-
Chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer Polymers (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), Styrene-methacrylate copolymers (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.), styrene-α -Methyl chloroacrylate copolymer, styrene-acryloyl Tolyl - (homopolymer or copolymer containing styrene or styrene substituents) a styrene resin such as acrylic ester copolymer, a vinyl chloride resin,
Styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenolic resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene,
Examples include an ionomer resin, a polyurethane resin, a silicone resin, a ketone resin, an ethylene-ethyl acrylate copolymer, a xylene resin, and a polyvinyl butyral resin.

As the polymer particles contained in the coating layer, polymer particles having an average particle size of 0.1 to 100 μm are preferable. Examples of such high-molecular polymer particles include L-lysine particles (preferable particle size of 5 to 50 μm), particles made of silicone rubber or silicone resin (preferable particle size of 1 to 10 μm), polyvinylidene fluoride and polytetrafluoro. Ethylene homopolymer particles or copolymer particles (preferable particle size 0.1 to 1 μm), melamine-formaldehyde resin particles (preferable particle size 0.1 to 3 μm), lauryl aspartate particles (preferable particle size 1 to 1)
30 μm), polybenzisidazole particles (preferable particle diameter 10 to 100 μm), polyacrylonitrile particles (preferable particle diameter 1 to 10 μm), and nylon particles (preferable particle diameter 2 to 20 μm).

In addition to the above, polymer particles such as polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, Styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylate copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer) Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic ester copolymer (styrene-methyl methacrylate copolymer, styrene- Ethyl methacrylate copolymer, styrene-butyl methacrylate Alcohol copolymer and styrene - phenyl methacrylate copolymer), styrene -α- chloromethyl acrylate copolymer, styrene - acrylonitrile -
Styrene resins such as acrylic acid ester copolymers (homopolymers or copolymers containing styrene or styrene substituents), vinyl chloride resins, styrene-vinyl acetate copolymers, rosin-modified maleic acid resins, phenolic resins, epoxy Resin, polyester resin, low molecular weight polyethylene,
Constituent resin particles such as low molecular weight polypropylene, ionomer resin, polyurethane resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin, acrylic homopolymer and acrylic copolymer can be used.

For the coating layer other than the elastic layer, for example, a resistance adjusting agent, a releasing agent, a binder resin, a viscosity adjusting agent, a coloring agent, and the like are appropriately selected, and these components are dispersed and suspended in a solvent to prepare a coating material for the coating layer. Thereafter, it is formed by dip coating, spray coating, blade coating, roller coating curtain coating, or the like.

[0029] In the present invention, the solubility parameter SP1 of the binder resin contained in the paint coating layer, and the solubility parameter SP2 of the polymer particles added to the coating layer coating is | S
P1−SP2 | ≦ 4. The binder resin and the polymer particles in this relationship have a high affinity, and the polymer particles do not aggregate in the binder resin and exist uniformly over the entire layer in a state close to single particles. Can be. This high
If the molecular polymer particles have conductivity and are intended for resistance control, when a DC bias is applied to the intermediate transfer member,
A uniform electric resistance can be obtained over the entire surface of the intermediate transfer member, and transfer efficiency can be improved.

When the high molecular weight polymer particles have releasability, the high molecular weight is uniformly applied to the surface of the coating layer.
Since the coalesced particles are distributed, high transfer efficiency can be obtained.

Further, in the present invention, the amount of the polymer particles used can be reduced.

The solubility index SP1 of the binder resin and the high molecular weight
The relationship with the solubility index SP2 of the coalesced particles may be within the range of the above-described expression, and does not depend on the magnitude of SP1 and SP2.

The solubility index (SP value) is a characteristic value serving as a measure of miscibility. When the molecular cohesion energy is E and the molecular volume is V, the solubility index δ is given by the following equation.

Δ = (E / V) ^1/2

The solubility index (SP value) is one of the indices for expressing the intermolecular force of a substance, and is described in Journal App.
ly Polymer Science. , 19,11
63 (1975), it is expressed as the sum of the respective forces (energy) of dispersive force, polar effect, and hydrogen bond.

The thickness of the coating layer as the elastic layer is 0.5 to 1
It is preferably 0 mm. The thickness of the coating layer other than the elastic layer is 3 mm or less, further 2 mm or less, especially 20 μm or more.
It is preferably 1 mm.

As the conductive support, for example, metals and alloys such as aluminum, iron, copper and stainless steel, conductive resins in which carbon and metal particles are dispersed, and the like can be used. A belt-shaped thing is preferable.

The volume resistivity of the intermediate transfer member is 10 ¹ to 10 ¹³
Ω · cm, particularly preferably 10 ² to 10 ¹⁰
It is preferably Ω · cm. In order to control the resistance as described above, a resistance controlling agent such as an electron conductor or an ionic conductor can be added to the coating layer as appropriate as long as the performance is not hindered.

Examples of preferred electron conductors include conductive metal oxides, graphite, and metals (copper, aluminum,
Nickel and silver) and conductive polymers (polyaniline,
Polypyrrole, polythiophene, polyacetylene, polypyridine, polyacene, polyazulene, polydiphenylbenzidine, polyvinylcarbazole, poly-3-alkylthiophene, and the like. Of these, metals, polyaniline, polypyrrole and polythiophene are particularly preferred. Examples of preferred ionic conductors include metal salts and ammonium salts. Examples of the metal salt include salts of metals of Group I or Group II, and salts of Li, Na and K having a relatively small cation radius are particularly preferable. Examples of the anions constituting these metal salts include halogen ions (F, Cl, Br and I, etc.), thiocyanate ions, perchlorate ions, trifluoromethanesulfonate ions, fluoroborate ions and the like.
Of these, particularly preferred are thiocyanate, perchlorate, trifluoromethanesulfonate and fluoroborate. As the ammonium salt, carboxylic acids (adipic acid, phthalic acid,
Ammonium salts of acids such as azelaic acid), phosphoric acid, boric acid, sulfonic acid (such as arylsulfonic acid) and borofluoric acid. Of these ammonium salts, ammonium carboxylate, ammonium phosphate and ammonium borate are particularly preferred. The electron conductor and the ionic conductor may be used as a mixture.

When these resistance control agents are added to the coating layer, it is preferable to add them in an amount of 1.0% by weight to 200% by weight based on the solid resin content in the coating material for the coating layer.

The image forming apparatus shown in FIG. 5 uses a belt-shaped intermediate transfer member 104 as an intermediate transfer member.

As the first image carrier used in the image forming apparatus of the present invention, a roller-shaped or belt-shaped photoreceptor can be used, and the roller-shaped one has higher transfer efficiency and image superposition (registration). ) Can be minimized, which is preferable in the present invention.
It is presumed that this has a favorable effect because the rigid intermediate transfer member and the rigid photosensitive drum are in contact with each other.

As the photosensitive layer of the photosensitive member, an OPC (organic and photoconductor-containing) photosensitive layer, particularly a layer having a layer containing fluororesin particles on the outermost layer, has a friction between the rigid roller surface and the intermediate transfer member. It has advantages such as reduced high durability, improved transfer efficiency, and prevention of partial transfer failure.

[0044]

The present invention will be described below in detail with reference to examples. In addition, "part" shown below means "polymerization part".

Example 1 182 mm in diameter and 320 in length
A rubber compound having the following composition was transfer-molded on the surface of an aluminum cylindrical roller having a thickness of 5 mm and a thickness of 5 mm using a mold to obtain a roller (1) having an elastic layer having a thickness of 1 mm.

Rubber-blended NBR rubber 100 parts Zinc oxide 2 parts Conductive carbon black 10 parts Paraffin oil 30 parts Vulcanizing agent (sulfur) 2 parts Vulcanization accelerator (dibenzothiazyl disulfide, MBT
S) 3 copies

Next, in order to obtain a coating layer thereon, a coating material for a coating layer was prepared based on the following formulation.

Coating layer coating polyurethane (solubility index: 10) 100 parts Conductive tin oxide 40 parts Dispersing aid (coupling agent) 2 parts Spherical silicon rubber particles having an average particle diameter of 2.3 μm 30 parts (solubility index 7.5) 100) Kimiren

A coating layer having a thickness of about 50 to 200 μm was formed on the surface of the roller (1) by spray coating with the above coating material, followed by drying and curing at 100 ° C. for 60 minutes to obtain an intermediate transfer member.

The intermediate transfer was mounted on a full-color electrophotographic apparatus shown in FIG. 1, and a full-color image copying test was repeatedly performed using an OPC photosensitive drum having a photosensitive layer on an aluminum cylinder as a photosensitive member.

The image forming conditions of this embodiment will be described below.

Photoreceptor: OPC photosensitive drum Surface potential: -700 V Color developer (for all four colors): non-magnetic one-component toner Primary transfer voltage: +900 V Secondary transfer voltage: +3400 V Process speed: 120 mm / s Development bias: -500 V

As a result, the transfer efficiency (hereinafter referred to as primary transfer efficiency) from the photosensitive drum as the first image carrier to the intermediate transfer member is 95%, and the transfer efficiency from the intermediate transfer member to the second image carrier is 80 g. / M ² paper transfer efficiency (hereinafter referred to as secondary transfer efficiency) was 92%. The full-color copy image had characters and fine lines without any voids, and the solid image had a uniform image quality. Even after the endurance test of 10,000 sheets, the same image quality as in the initial stage was obtained, and the secondary transfer efficiency was hardly reduced to 89%. Microscopic observation of the surface of the intermediate transfer member after 10,000 copies did not show any filming with the toner.

Next, the entire halftone image having an image density of 0.8 was copied, and the homogeneity of the image quality was checked. However, it was good without partial density unevenness or white spot image.

Further, the intermediate transfer body using 10,000 sheets was rotated idly by repeating only charging and discharging without developing the toner up to 30,000 sheets, and its durability was confirmed. No scraping or peeling between the elastic layer and the coating layer occurred.

[Example 2] Acrylic rubber (solubility index: 9.6) 100 parts Conductive carbon black 8 parts Paraffin oil 20 parts Vulcanizing agent (sulfur) 2 parts Vulcanization accelerator (MBTS) 2 parts Average particle size 3.4 μm polymethyl methacrylate particles
30 parts (solubility index: 9.2)

The coating having the above composition was applied to the surface of an aluminum cylindrical roller in the same manner as in Example 1 to form a coating layer, thereby obtaining an intermediate transfer member.

This intermediate transfer member was used.
In the same manner as in the above, a repetitive copy durability test of 20,000 sheets of magenta alone was performed.

The transfer efficiency was 89% for the primary transfer efficiency and 84% for the secondary transfer efficiency, which was lower than the case where the coating layer was further provided on the upper layer of the elastic layer.
Significant effects were seen.

As for the image quality, a uniform halftone was obtained over the entire surface of the image, and there was no unevenness of density and no void.

After 20,000 sheets, the toner is fused on the intermediate transfer member,
Filming hardly occurred. The image quality was the same as the initial one.

Example 3 The binder resin of the coating material for the coating layer of Example 1 was fluororubber 100
Part (solubility index: 7.3), and the polymer particles were changed to 35 parts (solubility index: 9.03) of spherical polystyrene particles having an average particle diameter of 2.5 μm. The primary transfer efficiency was 96%, and the secondary transfer efficiency was 94%, which was considerably high, and the image quality was good with no voids.
Filming did not occur even after the durability test.

Example 4 The coating material for the coating layer used in Example 1 was applied to the surface of an endless polytetrafluoroethylene belt to obtain a belt-like intermediate transfer member. Using the full-color electrophotographic apparatus shown in FIG. 5, the belt was subjected to an endurance test of 10,000 sheets.

As a result, the same good results as in Example 1 were obtained.

[Comparative Example 1] A durability test was performed in the same manner as in Example 1 except that the intermediate transfer member (having only the elastic layer) which was not formed with the coating layer was used.
Filming gradually occurs on the surface of the intermediate transfer member from 000 sheets, and after 10,000 sheets, a fine streak appears as if raining on the image, resulting in an adverse effect of filming. It was impossible. In addition, the image quality was initially a negligible hollow image that could be ignored, but after 10,000 copies, the image quality was clearly poor with the center of the character missing. The initial transfer efficiency was as follows: primary transfer efficiency 91%, secondary transfer efficiency 7
6%.

Comparative Example 2 In Example 3, the spherical polystyrene particles were replaced with 66 nylon particles 45 having an average particle size of 5 μm.
The same test was conducted as in Example 3 except that the primary transfer efficiency was 79% and the transfer efficiency was 79%.
The secondary transfer efficiency was as low as 68%.

Further, during the durability test by repeated copying, nylon particles, which are high-molecular polymer particles, were gradually removed from the coating layer, and after about 10,000 sheets, filming due to the adhesion of toner to the intermediate transfer member was observed. Occurred, and white spots due to poor transfer and hollow spots in the character portion began to be noticeable. When the filming portion was observed with a microscope, it was confirmed that the toner was embedded in the trace where the nylon particles had fallen off, and this was a trigger, and it is presumed that toner adhesion was promoted. As described above, this intermediate transfer member was difficult in durability and was not practical.

[0068]

As described above, according to the image forming apparatus of the present invention, the transfer efficiency from the first image bearing member to the intermediate transfer member and from the intermediate transfer member to the second image bearing member are both high. Regardless of the type of paper or OHP sheet, it is possible to obtain a homogeneous image free from image defects such as image dropout. Good properties are maintained even after durability. Further, filming due to toner adhesion to the intermediate transfer member does not occur.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of the electrophotographic apparatus of the present invention.

FIG. 2 is a schematic sectional view of an example of an intermediate transfer member used in the present invention.

FIG. 3 is a schematic sectional view of an example of an intermediate transfer member used in the present invention.

FIG. 4 is a schematic sectional view of an example of an intermediate transfer member used in the present invention.

FIG. 5 is a schematic sectional view showing another example of the electrophotographic apparatus of the present invention.

FIG. 6 is a diagram illustrating an example of a blank image.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 20 Intermediate transfer member 100 Support 101, 102, 103 Coating layer

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiko Nakazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tsunetori Ashbe 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-5-46035 (JP, A) JP-A-5-173434 (JP, A) JP-A-4-184348 (JP, A) JP-A-5-72889 ( JP, A) JP-A-63-68678 (JP, A) JP-A-6-95415 (JP, A) JP-A-6-250460 (JP, A) JP-A-7-234592 (JP, A) JP-A-6-337598 (JP, A) JP-A-6-175510 (JP, A) JP-A-5-257398 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15 / 16 G03G 15/01 F16C 13/00

Claims (4)

(57) [Claims] 1. Contains a binder resin and high molecular weight polymer particles
An intermediate transfer member having a coating layer formed by applying a coating material for a coating layer to be coated , and an image carrier for transferring an image to the intermediate transfer member. The solubility index SP1 of the binder resin in the coating composition for coating and the solubility index SP2 of the polymer particles in the coating composition for coating layer are | SP1-
An image forming apparatus, wherein SP2 | ≦ 4. 2. The image forming apparatus according to claim 1, wherein each of said intermediate transfer member and said image bearing image member has a roller shape. 3. The image forming apparatus according to claim 1, wherein the intermediate transfer member has a belt shape, and the image carrier has a roller shape. 4. The image forming apparatus according to claim 1, wherein said image bearing member is an electrophotographic photosensitive member having an outermost layer containing fluorine resin particles.