JPH02156246A - Electroprotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance cleanability by incorporating a specified silicone type comb-shaped graft polymer in resin particles. CONSTITUTION:The silicone type comb-shaped graft polymer to be added to the resin particles that are dispersed into a surface layer is obtained by copolymerizing, preferably, the modified silicone of the condensation raction product of the silicone represented by formula I with the compound represented by formula II, with a compound having a polymerizable functional group. In formulae I and II, each of R1-R5 and R11 is alkyl or aryl optionally substituted by halogen; n is a positive integer; each of R8-R10 is H, halogen, alkyl, or aryl; X is halogen or alkoxy; and m is 1, 2 or 3. The graft polymer is added to the resin particles, preferably, in an amount of 0.1-10 wt.%, thus permitting cleanability to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor having low surface energy and excellent cleaning properties.

[Prior Art] Electrophotographic photoreceptors are required to have predetermined sensitivity, electrical properties, and optical properties depending on the electrophotographic process to which they are applied. Gender is also an important factor.

Various external forces such as corona charging, toner development, transfer to paper, and cleaning processing are directly applied to the layer furthest away from the substrate of the photoreceptor (hereinafter referred to as the 1st surface layer). These include abrasion and scratches due to rubbing, adhesion of paper dust from transfer paper, adhesion of toner, and material deterioration due to ozone generated during corona charging. In either case, problems arise that lead to a decline in image quality.

Additionally, cleaning processing is generally performed by bringing a rubber blade into contact with the surface of one photoreceptor.
If the coefficient of friction between the blade and the surface layer is large, the blade will curl up, making cleaning impossible.

For problems related to the photoreceptor surface layer,
It is preferable to impart lubricity and releasability to the surface layer and sufficiently lower the surface energy to improve adhesion and cleaning properties.

Methods for this purpose include an electrophotographic photoreceptor in which a photoconductive surface layer is formed by dispersing or dissolving a photoconductor substance in a binder resin, or an electrophotographic photoreceptor that does not contain a photoconductive component mainly composed of resin on the photoconductive layer. In electrophotographic photoreceptors provided with a protective surface layer, it is known to add a substance that imparts lubricity to the surface layer. Examples of such substances include fluorine-containing vinyl resin powders such as polytetra7ethylene, polyvinylidene fluoride, fluorine-containing surfactants, and silicon-containing surfactants.

[Problem to be solved by the invention]

However, even with these conventional methods, problems remain, such as deterioration of electrophotographic conductivity, insufficient countermeasure effects, and lack of long-term effects (over the entire life of the photoreceptor). Ta.

An object of the present invention is to improve the above-mentioned drawbacks and to provide an electrophotographic photoreceptor that has excellent surface lubricity and mold release properties, and has permanently excellent IJ = lubricating properties.

Another object of the present invention is to provide an electrophotographic photoreceptor that does not suffer from deterioration in image quality due to repeated cycling.

Still another object of the present invention is to provide an electrophotographic photoreceptor that can prevent the cleaning blade from turning over.

[Means to solve the problem]

The present invention aims to achieve the above object by dispersing particles containing a silicone-based comb-shaped graft polymer in the surface layer of an electrophotographic photoreceptor.

The silicone-based comb-shaped graft polymer used in the present invention preferably has the following general formula (1) and/or the general formula (
Silicone represented by 10 and the following general formula ■.

A polymer obtained by copolymerizing a modified silicone, which is a condensation reaction product with a compound represented by (g) or (g), and a compound having a monopolymerizable functional group, and a side chain group containing silicone. has a structure in which R1+ R2r R5+ R4 and R5 are an alkyl group, an aryl group, or a halide thereof,
nFi is a positive integer), General formula (II) (wherein R6 and R7 are an alkyl group, an aryl group, or a halogenide thereof, and n is a positive integer), General formula (II) In the formula, R8, R, and R1° are a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, RIt is an alkyl group, an aryl group, or a halide thereof, and
is a halogen atom or an alkoxy group; 9. mFil～
(In the formula, R12 is a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, "13 is an alkyl group, an aryl, or a halide thereof, and X is a halogen atom or an alkoxy group, y is 0 or 1, X is y=
When 0, it must be an integer between 0 and 2. When y=l, it must be 2,
rIIIVi is an integer of 1 to 3), general formula (9) (wherein R, 4, R, 5 and R16 are a hydrogen atom, a halogen atom, an alkyl group or an aryl group.

R17 is an alkyl group, an aryl group, or a halide thereof, A is an arylene group, X is a halogen atom or an alkoxy group, and 1m is an integer from 1 to 3)
.

The general formula (R1, R2, R3, R4 in (ID)
, R5°R6 and R7, specifically, the alkyl group includes a methyl group, ethyl group, globyl group, butyl group, etc., and may be substituted with a halogen atom or the like. Examples of the aryl group include a phenyl group and a naphthyl group, which may have a substituent. Preferably it is a methyl group or a phenyl group. n indicates the average degree of polymerization, and is 1 or more and 10
00 or less, preferably 10 or more and 500 or less.

Regarding R8, R, and R1° in the general formula (g), examples of hydrogen atoms and halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Further, both the alkyl group and the aryl group may have a substituent, and examples of the alkyl group include a methyl group, ethyl group, globyl group, and butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. . Preferably it is a hydrogen atom. For R,, Ic, the alkyl group is a methyl group, an ethyl group, a globyl group,
Examples include a butyl group, and may be substituted with a halogen atom. Examples of the aryl group include a phenyl group and a naphthyl group, which may have a substituent. Preferably it is a methyl group or a phenyl group. Regarding X, halogen atoms include fluorine atom, chlorine atom, bromine atom, and iodine atom), preferably chlorine atom. The alkoxy group is methoxy group.

It may have a substituent such as an ethoxy group, a globoxy group, or a butoxy group, and preferably a methoxy group, an ethoxy group, or a 2-methoxy-ethoxy group. m td
It is an integer from 1 to 3.

For R12 in the general formula (transformation), a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a f-lobyl group, a butyl group, or a 7-aryl group such as a phenyl group or a 7-tyl group is an acyl or alkyl group. , the aryl group may also have a substituent. Particularly preferred is a hydrogen atom or a methyl group. For R1, the alkyl group is a methyl group or an ethyl group.

It may be substituted with a propyl group, a butyl group, etc. or a halo atom. Examples of the aryl group include a phenyl group and a naphthyl group, which may have a substituent.

Preferably it is a methyl group or a phenyl group. Regarding X, halodane atoms include fluorine atom, chlorine atom, bromine atom, and iodine atom, preferably chlorine atom. The alkoxy group may have a methoxy group, an ethoxy group, a glopoxy group, a butoxy group, etc. or a substituent. Preferred are methoxy group, ethoxy group, and 2-methoxy-ethoxy group. y must be 0 or 1, X is y=0
If , it must be an integer between 0 and 2, and if y=1, it is 2, which is 0m
is an integer from 1 to 3.

Regarding R14, R15, R, and 6 in the general formula (to), examples of the hydrogen atom and the halodane atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Both an alkyl group and an aryl group may have a substituent group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Preferably it is a hydrogen atom. Regarding R17, the alkyl group is a methyl group, an ethyl group, a propyl group,
A butyl group or the like may be substituted with an atom, a halodane atom, or the like. The 7-aryl group may have a substituent such as a phenyl group or a naphthyl group. Preferably it is a methyl group or a phenyl group. For X, halodane atoms are fluorine atoms and chlorine atoms.

A bromine atom or an iodine atom is preferable, preferably a chlorine atom. As the alkoxy group, methoxy group, ethoxy group,
It may have a substituent such as a pro-Ioxy group or a butoxy group. Preferably methoxy group, ethoxy group or 2
-methoxy-ethoxy group. Regarding A, 7-arylene groups such as phenylene group, biphenylene group, and 7-tyrene group are a).

0m, which may have a substituent, is an integer of 1 to 3.

Specific examples of general formulas (1) to (g) are shown below.

Specific example of general formula (1): Edition CC2H5C2H 3CCB.

CH, CH.

C4H3C4CH.

CH.

C2H3 C,H.

04H.

t t C2H5 ■ HO-+S10←H 2H5 C,H.

04H.

HO-(81-0 leak-H C4H.

HO machine S i O+-H 2H5 HO-(810 leak-H C3H.

2H5 HO-+810 inch H amount C4H.

4H8CL ■ C4H, C1 H HO-(S103-H ■ 4H8C2 HO-(S103-H 2H5 Specific example of general formula (to): H OCR.

C2H5 Q.C., H.

HQ04H.

HHCL c=c-81-C1 H.C.L. HF C=C-8l-F HF Hctct c=c-81-CL H.C.L. OCR.

c=c -8l-C1 H.C.L. c2H5 cm2ct QC4HISBr QC2H40C2H5 2H5 OCR.

C2H3 c=c-st-cz +1 H.C.M.

c=c　-Si　-F 0C2H6 C2H5 OCH.

C2H5 C2H5 11r QC4H.

0C4H80C2H5 CH3 C2H5 QC4H.

t C2H5 0c4H80C2H5 oc2H4°IcH.

Specific example of general second beat: CR3 C2H5 truth C3H7 QC4H.

OCR.

OCR.

CH3 2H5 CH2=CH-C-QC, H6-8i-OCH.

0 0CH.

05H.

CH2=CH-C-QC, H, -8i -C3H.

++ 1 0C2H5 C4H.

CH5 CH2=CH-C-QC3H6-8 amount-CtI+
10 CH.

2H5 t C, H5 I OCH2CM20CH.

0CH2C120CH.

OCR.

C215 C2H.

0M2-CH-C-QC2H4QC, H6-8l -Q
C2H50QC2H5 C,H.

Hot CH, -CH-C-QC2H4QC, H6-8i -C
L0 C, H.

Q.C., H.

Q.C., H.

QC4H.

OCR.

C2H5 O C2H5 0-04H.

t t C2H5 C3H.

2H4C2 C2H5 t C2H5 t C3H7 OCR.

0CH5 C2H3 Q.C., H.

OCR.

Specific example of general nien: Q.C., H.

QC4H.

OCR.

C2H5 C3H7 QC4H.

OCH3 CR5 C2H5 2H5 0-0M2CH20CH.

0CR2CH200R.

C2H3 QC4H.

t t t C,H.

CH.

OCH.

QC2H5 QC3H.

OCR.

CH3 QC2H.

QC4H.

QC4H.

OCR.

C2H3 Q.C., H.

t t 2H5 0-CH2CM2OCH3 0CR2CH200R.

QC, H3 O3H.

C2H5 C2H5 C2H3 QC, H5 The condensation reaction between a silicone represented by general formula (1) and/or general formula () and a compound represented by general formula It is possible to obtain a stable modified silicone by appropriately controlling the reaction molar ratio and reaction conditions, as shown in JP-A-58-167606, for example, as shown in JP-A-58-167606. can.

Examples of compounds having a polymerizable functional group include polymerizable monomers that do not have silicon atoms, or macromonomers that are relatively low molecular weight polymers with a molecular weight of about 1,000 to 10,000 that have a polymerizable functional group at the end. Can be mentioned. Examples of polymerizable monomers include olefinic compounds such as low molecular weight linear unsaturated hydrocarbons such as ethylene, propylene, and butylene, vinyl halides such as vinyl chloride and vinyl heptadide, and organic acids such as vinyl acetate. pinyl esters of styrene, styrene substitutes, and other vinyl aromatic compounds such as vinylpyridine and vinylnaphthalene; -vinylcarbazole, N
Examples include N-vinyl compounds such as -vinylpyrrolidone and N-vinylcaglolactam, and vinyl silicon compounds such as vinyltriethoxysilane. Disubstituted ethylenes can also be used, examples of which include vinylidene fluoride, vinylidene chloride, etc., and esters of maleic anhydride, maleic acid and hyfumaric acid.

The monomers can be used alone or in combination of two or more monomers.

Although radical polymerization and ionic polymerization such as solution polymerization, suspension polymerization, and bulk polymerization can be used as a polymerization method for silicone-based comb-shaped graft polymers, radical polymerization by solution polymerization is preferred because it is simple.

The copolymerization ratio is 5 to 90 as the silicone monomer content.
% by weight is preferable, and 10 to 70% by weight is more preferable.

The number average molecular weight of the obtained polymer is 5
00 to 100000. Particularly preferred is 1000 to 5oooo.

The silicone-based comb-shaped graft polymer of the present invention has a structure in which silicone-containing side chain groups are bonded to the main chain in a branched manner, and the silicone-containing branch portions have excellent interfacial migration properties. Therefore, by adding it to the main resin, it is possible to significantly lower its surface energy. Furthermore, if the polymerizable monomer and the main resin are selected to have a certain degree of compatibility, there will be no problems such as migration or precipitation of the silicone graft polymer.

However, when a silicone-based comb-shaped graft polymer is applied to the surface of an electrophotographic photoreceptor, the effect does not last long because the graft polymer locally present on the surface is scraped off by the rubbing of the surface layer during the electrophotographic process. It is limited to a very short period of time.

In view of this, the present inventors have made it possible to uniformly contain the graft polymer in the bulk of one surface layer by dispersing particles containing a silicone comb-shaped graft polymer in the surface layer.

For this reason, even if the surface layer is rubbed and scraped off, the surface properties do not change and high cleaning performance can always be maintained.

Next, an example of a method for producing particles whose surfaces are coated with such a silicone-based comb-shaped graft polymer will be described. First, the above-mentioned silicone-based comb-shaped graft polymer is added to a solution of a resin hexamer or oligomer as a main material forming particles and a crosslinking agent. This solution is dispersed in a solvent that is incompatible with the solvent used, and crosslinked and polymerized to form resin particles. At this time, as described above, the silicone bilimer is localized on the surface of the polymerized particles due to the interfacial migration property of the silicone comb-shaped graft polymer.

A general polymer is used as the main resin, but it is desirable that it is insoluble in the dispersion solvent used to form the surface layer. In addition, since compatibility with silicone comb-type graft polymers is required, vinyl monomers or oligomers are preferred. Examples include acrylic esters, methacrylic esters, and styrene. In addition, the polyfunctional heptamers for crosslinking include sovinylbenzene,
Known materials such as triethylene glycol, diacrylate, 1,6-hexanediol diacrylate, etc. can be used.

The amount of the silicone comb-shaped graft polymer added to the main material is preferably 0.1-10%. If it is less than 0.1%, the intended sufficient surface property improvement effect cannot be obtained. 10 more
If it exceeds %, the compatibility with the main material decreases, which impairs the polymerization and particle formation process, making it impossible to obtain the desired particles.

The particle size of the particles is preferably 5 μm or less. 5
If it exceeds μ, the smoothness of the surface layer coating, dielectric strength, stability of the dispersion, etc. will be affected. Therefore, it is preferable to crush and classify the obtained polymer particles to appropriately control the particle size.

The polymer particles thus obtained are dispersed in the surface layer of the electrophotographic photoreceptor. the non-photosensitive surface layer of the photoreceptor having a surface layer, (ii
) The non-photosensitive surface J of a photoreceptor having a laminated photosensitive layer consisting of a charge generation layer and a charge transport layer and a non-photosensitive surface J-
1i, GiD [The charge transport layer of a photoreceptor whose surface layer is a layered photosensitive I scratch consisting of a charge generation j- and a charge transport j-,
There is a charge generation layer of a photoreceptor whose surface layer is a laminated photosensitive layer consisting of a 4ψ charge generation J- and a charge transport layer.

4'2 on a magnetic substrate, and 7 as a charge generation layer and a charge transport layer.
The case where one large layer is used will be explained below. In this case the surface layer is a charge transport layer.

Examples of charge transporting substances include pyrazoline compounds, hydrazone compounds, and stilbene compounds.

Common compounds such as triphenylamine compounds, benjisone compounds, and oxazole compounds can be used. Further, the binder resin may be appropriately selected from known binder resins. For example, acrylic resin, 1f! Insulating resins such as IJ arylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butanoene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, or poly-N
-Organic photoconductive polymers such as vinylcarbazole, holivinylanthracene, polyvinylpyrene, etc.

These binder resin and charge transport material are dissolved in a suitable solvent, and the silicone polymer coated particles are dispersed in a light source. As a dispersion method, a conventional method such as a curl mill, a sand mill, a homogenizer, an ultrasonic wave, an attritor roll mill, etc. can be used. The thus obtained dispersion coating liquid is coated by an appropriate coating method on the charge generation layer formed by the method described below, and dried.
Form a charge transport layer.

The combined amount of silicone polymer coating particles is preferably 0.5 to 40% with respect to the total solid partial pressure of the charge transport layer.
Furthermore, K is preferably 1 to 20%.

If it is less than 0.5%, the effect of the present invention due to the addition of #'i will not be sufficiently obtained, and if it exceeds 40%, the electrophotographic properties such as a decrease in the carrier transport ability of the charge transport layer and a decrease in light transmittance will occur. In addition to being a regular customer, it is also undesirable because it can damage the smoothness of the paint film.

In addition, for the purpose of improving the dispersibility of the silicone polymer coated particles, general dispersants, surfactants, etc. may be added to the extent that they do not have specific characteristics.

The following Kvi charge-generating layers include pyridium, thiopyrylium dyes, phthalocyanine pigments, andanthrone pigments, zopenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine, and quinocyanin. ,
It is formed by coating a substrate with a coating liquid in which a charge-generating material such as zinc oxide is dispersed in a suitable binder solution, or by vapor-depositing selenium, selenium-arsenic, selenium-tellurium, amorphous silicon, etc. onto a substrate. Ru.

A subbing layer having barrier and adhesive functions can also be provided between the substrate and the photosensitive layer. Undercoat layer C, casein, polyhinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer I-vinyl butyral, phenolic resin, polyamide (nylon 6, nylon 66, nylon 610° copolymerized nylon, alkoxymethylated nylon, etc.), It can be formed from polyurethane, gelatin, aluminum oxide, etc.

The thickness of the undercoat layer is 0.1 micron to 40 micron, preferably 0.1 micron to 3 micron.

As the substrate having a conductive layer, the substrate itself has conductivity, such as aluminum, aluminum alloy, copper,
Zinc, stainless steel, vanadium, molybdenum, chromium,
Substrates made of titanium, nickel, indium, gold, platinum, etc. can be used, as well as aluminum and aluminum alloys.

A base made of plastic (e.g., polyethylene, polypropylene, polyvinyl chloride, polyfluorinated tyrene, etc.) having a layer formed by vacuum deposition of indium oxide, tin oxide, indium oxide-tin oxide alloy, etc.
Conductive particles (e.g.

Substrates obtained by coating plastic with carbon black, silver particles, etc.) together with an appropriate binder, substrates obtained by impregnating glass or paper with conductive particles, and conductive materials.
A substrate made of glass or the like having a reamer can be used.

The silicone comb-shaped graft polymers (samples a to j) used in the following examples were synthesized according to the polymerization method described in JP-A-58-167606, and their compositions are shown in Table 1. As shown.

Table 1: Composition of silicone-based graft polymer composition.

Silicone comb-shaped graft polymer coach in polyvinyl alcohol o, s, y was dissolved in boiling water 30°C,
This was diluted with 500ml of water. This was placed in a three-way flask equipped with a stirrer and a reflux condenser, and 18 methacrylic acid methyl ester monomers, 11 l divinylbenzene, 0.29 benzoyl peroxide, and the silicone comb-shaped graph shown in Table 1) were added. Rimmer (sample Am) 1
g and stirred. While stirring, increase the temperature to 9 for 30 minutes.
Raise the temperature to 0℃ and keep it at this temperature for 4 hours, then stop heating.

It was allowed to cool to room temperature. After cooling, the precipitated polymer particles were separated, washed with water, and dried. The yield was 18.81. This was roughly pulverized with a speed mill, then finely pulverized with a Noet mill, and a powder of 1 to 2.5 μm was obtained with an air classifier.

Similarly, the silicone comb-shaped graft shown in Table 2?
Remer coated particles were obtained.

Example 1 An 80φ x 360mm aluminum cylinder was used as a base.

Next, phenol resin (trade name Nibraio-7en J-
325, manufactured by Dainippon Ink) 10 parts, conductive titanium oxide (
Product name Kronos ECT-62, manufactured by Titan Kogyo) 11 parts and white titanium oxide pigment (Product name Titone 5R-I)
T, made by Sakai Chemical Co., Ltd.) was dispersed in a mixed solvent of methyl cellosolve and methanol, and 9 parts of the paint was applied on the substrate to produce 20 parts.
A zero layer was formed on the surface of μ.

Next, a 5% methanol solution of polyamide resin (trade name: Amilan CM-8000, Toshiten) was provided on the surface coating layer as an injection prevention layer. The film thickness was 0.7μ.

Next, 10 parts (parts by weight, the same applies hereinafter) of a disazo pigment having the following structural formula was added to this dispersion, and 70 to 120 parts of tetrahydro7ran (as appropriate) was added.
A charge generating layer having a thickness of 0.15 .mu.m was formed by adding 1.0 km of cloth onto the undercoat layer.

Next, 10 parts of bisphenol type polycargenate resin (trade name Z-200, Mitsubishi Gas Chemical Exhibition), 5 parts of the silicone-based comb-shaped graft polymer coated particles (sample AA) obtained in the above synthesis example, and 40 parts of monochlorobenzene were added. and 15 parts of dichloromethane. A portion of a hydrazone compound having the following structural formula was dissolved in this to prepare a charge transport layer coating solution.

Polyvinyl butyral resin (product name: Eslec BX-
L, manufactured by Miki Kagaku) and 50 parts of cyclohexanone were dispersed in a sand mill for 20 hours.

This coating solution was coated on the charge generation layer and heated at 120°C for 1 hour.
A charge transport layer of 19 microns was formed by drying for an hour. This is referred to as photoreceptor l. For comparison, a sample in which the silicone comb-shaped graft polymer coating particles were not dispersed was prepared in the same manner as above.

This will be referred to as photoreceptor 2.

The electrophotographic photoreceptor thus produced was -5,6k
V corona charging, image exposure, dry toner development.

Toner transfer to plain paper, urethane rubber blade (hardness 7
0. (pressure 24 items, contact angle to photoreceptor 20°)
It was installed in an electrophotographic copying machine equipped with a cleaning agent, etc., and tested for durability by producing one image. The result is the third
Shown in the table.

Table 3 Example 2 A 30φ×260 cage aluminum cylinder was used as the base. A surface coating layer was added to this as in Example 1.

An injection prevention layer and a charge generation layer were sequentially applied. Next, 10 parts of a styrene-methyl methacrylate copolymer resin (trade name: Estyrene Nl9-600, Nippon Steel Chemical Exhibition) and 6 parts of the silicone-based comb-shaped graft polymer coated particles (sample AB) obtained in the above synthesis example were mixed with monochlorobenzene. 38i and 12 parts of dichloromethane. 8 parts of the same hydrazo compound as in Example 1 was dissolved in this to prepare a charge transport layer coating solution. This coating solution was coated on the charge generation layer and dried at 120°C for 1 hour.
A charge transport layer of 9μ was formed. This will be referred to as a photoreceptor 3.

Examples 3 to 6 Photoreceptors were prepared in exactly the same manner as in Example 2, except that a charge transport layer in which silicone comb-shaped graft polymer coating particles of sample AC-F' were dispersed was provided. These are referred to as photoreceptors 4 to 7. A photoreceptor without particles dispersed therein was also produced in the same manner. This is the photoreceptor 8.
For the above photoconductors 3 to 8, a photocopying machine (FC-5
, Canon family) to test its durability by displaying images. The results are shown in Table 4.

Problems such as poor cleaning shown in Table 4 do not occur.

In this regard, the effect of the present invention was confirmed by measuring the frictional resistance of the surface.

The results are shown in Table 85. Photoreceptors 9 to 12 were obtained by using the silicone comb-shaped graft polymer coated particles of samples AC, H, I, and J in the method of Example 2.

As is clear from these results, the photoreceptor having a surface layer in which silicone-based comb-shaped graft polymer coating particles are dispersed has excellent surface releasability permanently, so it is difficult to prevent blade reversal and paper powder adhesion. Image fading or toner under high humidity [Effects of the invention] As described above, the electrophotographic photoreceptor of the present invention has surface slipperiness,
It has excellent long-lasting mold release properties, does not cause blade reversal or image blurring, and can always form stable, high-quality images.

Claims (2)

[Claims] (1) An electrophotographic photoreceptor in which resin particles are dispersed in a layer farthest from a substrate, characterized in that the resin particles contain a silicone-based comb-shaped graft polymer. (2) The silicone-based comb-shaped graft polymer is a silicone represented by the following general formula (I) and/or general formula (II) and a compound represented by the general formula (III), (IV) or (V). The electrophotographic photoreceptor according to claim 1, which is a polymer obtained by copolymerizing a modified silicone which is a condensation product with a compound having a polymerizable functional group: General formula (I) ▲ Numerical formula, chemical formula , tables, etc. ▼ (In the formula, R_1, R_2, R_3, R_4 and R_5 are an alkyl group, an aryl group, or a halide thereof, and n is a positive integer), General formula (II) ▲ Numerical formula, There are chemical formulas, tables, etc.▼ (In the formula, R_6 and R_7 are alkyl groups, aryl groups, or halides thereof, and n is a positive integer.)
, General formula (III) ▲ Numerical formulas, chemical formulas, tables, etc. It is a halide, where X is a halogen atom or an alkoxy group, and m is a positive integer from 1 to 3), General formula (IV) ▲ Numerical formula, chemical formula, table, etc. are available ▼ (In the formula, R_1_2 is a hydrogen atom , is an alkyl group, an aryl group or an aralkyl group, and R_1_3 is an alkyl group,
an aryl group or a halide thereof, X is a halogen atom or an alkoxy group, y is 0 or 1, x is an integer of 0 to 2 when y = 0, and when y = 1,
2, m is an integer from 1 to 3), General formula (V) ▲ Numerical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1_4, R_1_5 and R_1_6 are hydrogen atoms, halogen atoms, alkyl groups, or is an aryl group, R_1_7 is an alkyl group, an aryl group, or a halide thereof, A is an arylene group, X is a halogen atom or an alkoxy group, and m is an integer of 1 to 3).