JPS62205358A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having excellent lubricating and mold releasing properties of a surface of the titled body by incorporating a comb type graft polymer composed of a specific silicone and a polyarylate resin to a layer which exist the most far from the substrate at least. CONSTITUTION:The comb type graft polymer composed of the copolymer of a condensation reaction product of silicone shown by formulas I and or II, and at least a compd. shown by formula III and a polymerizable compd. contg. an unsatd. binding, and the polyarylate resin are incorporated to the layer which exists the most far from the substrate at least. In the formulas, R1, R2, R3, R4, R5, R6, and R7 may be substd, and are each an alkyl or an aryl group, (n) is an average polymerization degree, R8 is H atom, or may be substd. an alkyl group, R9 may be substd. and is an alkyl or an aryl group, X is halogen atom or an alkoxy group, (m) is 0 or 1. When (m) is 0, (l) is 0-2, when (m) is 1, (l) is 2, (k) is 1-3. Thus, the titled body having improved cleaning and repeating durability properties is obtd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an electrophotographic device that can be widely used in electrophotographic application fields such as electrophotographic copying machines, laser beam printers, CRT printers, and electrophotographic plate making systems. Regarding photoreceptors.

[Conventional technology]

Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have conventionally been used as photoconductive materials for electrophotographic photoreceptors. On the other hand, organic photoconductive materials such as polyvinylcarbazole, oxadiazole, and phthalo-7anine have advantages such as non-pollution and high productivity compared to inorganic photoconductive materials.
It is widely used (Haru).

As a matter of course, electrophotographic photoreceptors are required to have predetermined sensitivity, electrical properties, and optical properties depending on the electrophotographic process to which they are applied. In particular, for photoreceptors that can be used repeatedly, the surface layer of the photoreceptor, that is, the layer furthest from the substrate, is directly exposed to electrical and mechanical external forces such as corona charging, toner development, transfer to paper, and cleaning processing. Since these materials are added, durability against them is required. Specifically, durability is required against a decrease in sensitivity, a decrease in potential, an increase in residual potential due to deterioration due to ozone generated during corona charging, and the occurrence of surface abrasion and scratches due to rubbing.

Also, adhesion of paper dust due to contact with paper is one of the causes of image fading under high humidity conditions, and toner filming and residual toner due to poor cleaning can significantly impair the resulting image. Therefore, there is a need to form a photoreceptor surface that is less susceptible to contamination and easier to remove.

Conventionally, various methods have been proposed to solve the above-mentioned drawbacks. As one of these methods, the use of polyarylate resin as a binder for the surface layer is being considered. yJ?
Polyarylate resin has good abrasion resistance, so in a photoreceptor using polyarylate resin as the surface layer 74, the durability against external mechanical forces is greatly improved. However, since the amount of abrasion of the surface layer decreases, cleaning performance of adhering paper powder and residual toner becomes poor.
On the contrary, this will cause deterioration in image quality. In order to improve this problem, attempts have been made to impart lubricity and release properties to the surface layer, making it difficult for paper dust and residual toner to adhere to it and making it easier to clean. As a means for this, there are methods of adding general coating film surface modifiers, ie, leveling agents, silicone oil, etc., and dispersing Teflon powder, etc.

However, these general surface modifiers have poor compatibility with the components of the coating liquid to which they are added, so they migrate or ooze out onto the surface layer during long-term use, reducing the sustainability of their effects. There was a problem. In addition, when the surface layer itself forms a photoconductive layer (17), the surface modifier has poor compatibility with the photoconductive substance, and furthermore, it tends to be a drag against the movement of carriers due to photogeneration, and it is difficult to repeatedly There was a tendency for the residual charge to increase due to the photographic process. On the other hand, a surface layer in which Teflon powder or the like is dispersed has problems such as poor dispersibility, decreased transparency, and carrier drag.

[Problem that the invention seeks to solve]

The present invention solves the conventional problems and provides an electrophotographic photoreceptor with excellent surface lubricity and mold releasability, extremely good cleaning properties, excellent repeat durability, and less damage to the surface layer. The purpose is to

Another object of the present invention is to provide an electrophotographic photoreceptor that does not accumulate residual charge during repeated electrophotographic processes and can always produce high-quality images.

The present invention aims to achieve the above object by containing a specific silicone-based comb-shaped graft polymer and polyarylate-based resin in at least the layer farthest from the substrate of an electrophotographic photoreceptor.

[Means for solving problems]

That is, the present invention is based on the general formula (1) %Formula% (In the formula, R1+ R2* Rg r R4v R5 represents an alkyl group or an aryl group that may have a substituent, and b represents the average degree of polymerization.) and/or general formula (1) % formula % (in the formula, R6, R, represents a proper alkyl group or aryl group with a substituent, and n represents the average degree of polymerization) silicone and at least general formula (2)% formula%
) (wherein, R8 represents a hydrogen atom or an alkyl group, aryl group, or aralkyl group that may have a substituent; R9 represents an alkyl group or aryl group that may have a substituent;
represents a halogen atom or an alkoxy group. m represents 0 or 1; when m=0, t represents an integer from O to 2; when m=1, t represents 2. k represents an integer of 1 to 3. ) Contains a silicone comb-shaped graft polymer, which is a copolymer of a condensation reaction product with a compound represented by the following formula, and a polymerizable unsaturated bond-containing compound, and a prearylate resin, at least in the layer furthest from the base. This is an electrophotographic photoreceptor characterized by the ability to

The present invention will be explained in detail below.

The silicone-based comb temperature graft polymer used in the present invention is a modified silicone which is a condensation reaction product of a silicone represented by the following general formula (1) and/or general formula (I[) and at least the following general formula (to). It is obtained by copolymerizing a compound having a polymerizable functional group with a compound having a polymerizable functional group, and has a structure in which silicone-containing side chain groups made of modified silicone are bonded to the main chain in a branched manner.

General formula (1) Alkyl group that may have substituents or represents an aryl group, and n is a flat Indicates the degree of homopolymerization.

General formula (n) Alkyl group or aryl group which may be represents a polymer group, and n represents the average degree of polymerization. 0 General formula (to) an alkyl group that may have a substituent, Indicates an aryl group, an aralkyl group, R9 is an alkyl group which may have a substituent. Indicates a kill group or an aryl group, and X is Indicates a halogen atom or an alkoxy group. vinegar. m is 0 or 1, t is m==0 If an integer from 0 to 2, if m-1 2 is shown. k represents an integer from 1 to 3 vinegar.

In the general formulas (1) and (II), R1e R2*
R5*R4tR5, R6 and R7 are specifically alkyl groups such as methyl, ethyl, propyl, butyl, or aryl groups such as phenyl and naphthyl, and have a substituent such as a halogen atom or a lower alkyl group. Good too. Preferred are methyl group and phenyl group.

n indicates the average degree of polymerization, and is in the range of 1 to 1000, preferably in the range of 1O to 500.

In the general formula (2), R8 is specifically a hydrogen atom,
Halogen atoms such as fluorine, chlorine, bromine, and iodine; monoalkyl groups such as methyl, ethyl, propyl, and butyl; or aryl groups such as phenyl and naphthyl; A hydrogen atom or a methyl group is preferable.

Specifically, R2 is an alkyl group such as methyl, ethyl, propyl, and butyl, or an aryl group such as phenyl and naphthyl, and may have a substituent such as a halogen atom. Preferred are methyl group and phenyl group.

Specifically, X is a hydrogen atom, a halogen atom such as fluorine, chlorine, bromine, or iodine, preferably a chlorine atom, or an alkoxy group such as methoxy, ethoxy, propoxy, or butoxy, and a lower alkoxy group such as It may have a substituent. Preferably methoxy group, ethoxy group, 2
-methoxy-ethoxy group. m id O or 1
, t is an integer from 0 to 2 when m-0, 2 when rn=1, and k is an integer from 1 to 3.

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

Specific example of general formula (1) shop CR2CHs C4) T8ctcH3 CHCH5・ C2H5C,H.

16, HO-(810) 5i-CH.

C4H, CH3 ShiL ・Specific example of general formula (IN) Flat CH3 2:6.　　　　HO4SIO(H CH5 2H5 27, HO machine SiO9H 2H5 3H7 28゜　　　Ho-(sio→-H C,H.

4H9 29, HO-(-81-0+-H C4H? CH.

30, HO-cS ioi Hζ 2H5 CH5 31. HO-(SiO)-HC,H.

2H5 32, HO-(SiO92H Star 04H.

4H8Ct 33, HO (810+-H blind 4H8Ct CH3 34, HO-4810→-H summer C2XI8C1 Mari C2H3 Specific example of general formula (2) CH.

CH3 CH3 CH3 CH3 47, CH2寞CH-C-QC3H6-8i -QC2
H4CH.

0 CH.

CH.

CH5 CH.

CH3 51, CI(2=CI(-C-QC3H6-8t -Q
C4H.

0 0C4H.

CH.

OCR.

53, CH2-CH-C-oc,)I6-s
i-0CR.

0 0CR.

C2H5 blind C3H7 C4H9 56, Cl2=CH-C-QC, ll6-8i -QC
4H? 0C4H9 CH.

CH.

2H5 3H7 4H9 61, CH2=CH-C-QC, H6-8t -QC4
H.

0 0-C4H.

CH3 2H5 t " CH3 2H5 " CH.

blindness 0CH2CH20CH3 CH3 2H5 C, H7 ■ OC3H.

OCH3 0CH3 74, CH2''C-C-QC5H6-5i-QC3H.

0 CH3 0CH3 76, CH2-C-C-QC, H6-8t-QC2H4
0CH.

0 CH.

OQC,H.

OQC4H.

0M30CHy.

0 0C2H5 0QC5H.

0C4H9 00CH.

0 0CH3 00C2H5 90, CH2=C-C-QC3H6-81-QC4H9
00-C4H.

OCR.

Oct Oct 0 C2H3 O0-CH2CH20CH5 00CH2CH20CH.

0OC2H5 0C3H7 0C2H4Ct 0 Ct C2H3 OCt 0 0CH.

0 0CH3 110, CH2=C-C-QC2H,QC,H6-81
-C)(30CH3 The condensation reaction between the silicone represented by the general formula (I) and/or the general formula (II) and the general formula (g) proceeds very smoothly according to ordinary organic chemical reaction operations, such as a comb-shaped According to JP-A-58-167606 and JP-A-59-126478, which disclose methods for synthesizing glatt polymers, multistable modified silicones can be obtained by appropriately controlling the reaction molar ratio and reaction conditions. .for example,
When X of the compound represented by the general formula (to) is a chlorine atom,
A silicone compound of general formula (1) and/or (II) and an acid acceptor such as an amine are dissolved in a suitable solvent such as tetrahydrofuran or acetone at a concentration of 10 to 50% by weight. The compound or its solution is added dropwise at room temperature. After the reaction, the generated acid acceptor hydrochloride is separated by F,
The desired modified silicone can be obtained by removing it, then washing with water if necessary, and evaporating the solvent.

Compounds having a polymerizable functional group include macromonomers consisting of polymerizable monomers that do not have silicon atoms or 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 fluoride, and vinyl acetate. [acrylic acids including vinylnystyl, styrene, styrene substitutes and other vinyl aromatic compounds such as vinylpyridine and vinylnaphthalene, acrylic acid, methacrylic acid, and their esters, amides and acrylonitrile;
Derivatives of methacrylic acid, N-vinylcarbazole, N-
Examples include N-vinyl compounds such as vinylpyrrolidone and N-vinylcaglolactam, and vinyltriethoxysilane-like vinylsilicon compounds. Disubstituted ethylene can also be used, and other examples include vinylidene fluoride, vinylidene chloride, etc., and esters of maleic anhydride, maleic acid, and fumaric acid can also be used.

In particular, from the viewpoint of affinity with polyarylate resins, acrylic esters, methacrylic esters, styrene, etc. are preferred. Further, the polymerizable monomer can be used alone or in combination of two or more types of polymerizable monomers.

Polymerizable macromonomers can be produced, for example, by radical polymerizing methyl methacrylate in the coexistence of thioglycolic acid.
It can be obtained by obtaining a monoterminal carboxylic acid grepolymer having a molecular weight of 1,000 to 10,000 and reacting it with glycidyl methacrylate.

As a polymerization method for silicone-based comb-shaped graft polymers, radical polymerization and ionic polymerization such as solution polymerization, suspension polymerization, )+LUK polymerization can be applied, but radical polymerization by solution polymerization is preferred because it is simple.

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

The molecular weight of the obtained polymer was 500 to 100,000 as a number average molecular weight. In particular, 1000 to 50000 is preferable.

Since the silicone-based comb-shaped graft polymer of the present invention has such a structure, it can be used as a binder resin for forming the surface layer according to the present invention, and has excellent compatibility with a coating liquid containing a polyarylate-based resin. The resulting coating film should have good transparency and a long-lasting effect without causing any migration or oozing onto the surface layer according to the present invention, and the silicone-containing branch portions should be at the interface. Since it has excellent migration properties, surface modification can be achieved by adding a small amount. Furthermore, even if this additive is contained in the surface layer, stable charging characteristics can be obtained without accumulation of residual charges due to the reverse electrophotographic process.

The polyarylate resin used in the present invention contains a linear polymer containing one or more repeating units represented by the following general formula [■].

However, in the formula, R12 and R13 are each a hydrogen atom, an alkyl group, or an aryl group, and specifically, an alkyl group such as methyl, ethyl, propyl, and butyl, a 7-aryl group such as phenyl, and naphthyl, and a dihalogen Substitutions such as atoms, lower alkyl groups, etc. may also be introduced. Also, R12
A cyclic structure may be formed together with the carbon atom bonded to R13, and specific examples thereof include a 7-chlorohexyl ring and a lactone structure.

Xl p X2 p X3 p and X4 are specifically hydrogen atoms.

Halodane atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as methyl, ethyl, propyl, and butyl; alicyclic alkyl groups such as cyclohexyl; aryl groups such as phenyl and naphthyl; and alkoxy groups such as methoxy and ethoxy. be.

The polyarylate resin used in the present invention is, for example, one or two diol compounds represented by the following general formula [■].
It can be obtained by a general polyarylate synthesis method such as the terephthalic acid chloride method using more than one species.

〔Record〕

However, in the formula, R12 and R13 are each a hydrogen atom, an alkyl group, or an aryl group, specifically an alkyl group such as methyl, ethyl, propyl, butyl, or a 7-aryl group such as phenyl or naphthyl. It may have a substituent such as a halogen atom or a lower alkyl group. Also, R12
A cyclic structure may be formed together with the carbon atom bonded to R13, and specific examples thereof include a cyclohexyl ring and a lactone structure.

X1 + X2 + These include aryl groups such as phenyl and naphthyl, and alkoxy groups such as methoxy and ethoxy.

Typical specific examples of the diol compounds used in the present invention are shown below using structural formulas.

Specific example of general formula [V] Structural formula Structural formula %formula%) Structural formula CH.

Pseudo CH5 CH, -CH-CH3 Structural formula l H3 H3 C, H7 Structural formula Structural formula H3 H3 Structural formula % Formula % Structural formula CH30P-QC) I3 0CR3 The amount of silicone comb-shaped graft polymer added is determined by the solid content of the surface layer. Based on weight, 0.01-1.degree. is suitable, particularly 0.05-5%.

If the amount added is less than 0.01%, a sufficient surface modification effect cannot be obtained, while if it exceeds 10%, the graft polymer will exist not only on the surface of the coating film but also in the bulk, making it the main component of the surface layer. Whitening occurs due to compatibility problems with resins and photoconductive materials, and residual charge buildup occurs when repeated electrophotographic processes are performed.

When producing the electrophotographic photoreceptor of the present invention, a metal such as aluminum or stainless steel, a cylindrical cylinder or a film made of paper, glass, or the like is used as the substrate. A subbing layer (adhesive layer) having a barrier function and a subbing function can be provided on these substrates.

The undercoat layer is formed to improve the adhesion of the photosensitive layer, improve its coating properties, protect the substrate, cover defects on the substrate, improve charge injection from the substrate, and protect the photosensitive layer from electrical breakdown. Ru. Known materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, copolymerized nylon, glue, gelatin, and the like. These are each dissolved in a suitable solvent and applied onto the substrate.

The film thickness is about 0.2 to 2μ.

Examples of charge-generating substances include pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthoanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine, quinocyanine, etc. Can be used.

As the charge transport substance, pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-
Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-sifzylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazone-3-methylidene-1O-ethylphenothiazine, N,N- diphenylhydrazino-3-methylidene-10-ethylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p
-diethylaminopenzaldehyde N-α-naphthyl-N-7enylhydrazone, p-pyrrolidinobenzaldehyde-N,N-diphenylhydrazo 7.11313-
) IJ methylindolenine-ω-771/dehyde N, N-diphenylhydrazino, hydrazones such as p-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis(p-diethylaminophenyl ) -1,3,4-oxadiazole,
1-phenyl-3-(p-diethylaminostyryl)-
5-(p-diethylaminophenyl)pyrazoline, 1-
[Quinolyl(2)]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2))-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl) phenyl)
Pyrazoline, 1-(6-medoxyviridyl(2))
-3-(p-diethylaminostyryl)-・5-(p
-diethylaminophenyl) hilazoline, 1-[pyridyl (3)) -3-(p-diethylaminostyryl)-5-(p-1'ethylaminophenyl) hilazoline, 1-[lepidyl (2)) -3- (p-diethylaminostyryl)-5-(p-diethylaminophenyl)
Pyrazoline, 1-(Biri, Sol(2) ]-3-(p
-diethylaminostyryl)-4-methyl-5-(p-
diethylaminophenyl) hirazoline, 1-[pyridyl(2))-3-(α-methyl-p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-phenyl-3-(p-diethylaminostyryl)- 4-Methyl-5-(p-diethylaminophenyl)vira! +)”/, 1-tubonyl-3-(α-pen・
True p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, spiropyrazoline and other pyrazolines, 2-(p-diethylaminostyryl)-6-dinithylaminopenzoxazole, 2-(p-diethylaminostyryl)-6-dinithylaminopenzoxazole,
Oxazole compounds such as -diethylaminophenyl)-4-(p-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(p--7ethylaminostyryl)-6-dinithylaminobenzothiazole, etc. Thiazole compounds, bis(4-f ethylamino-
Triarylmethane compounds such as 2-methylphenyl)-phenylmethane, 1.1-bis(4-N,N-diethylamino-2-methylphenyl)hebutane, 1.1,
2.2-tetrakis(4-N,N-dimethylamine-2
Polyarylalkanes such as -methylphenyl)ethane and the like can be used.

The photoreceptor of the present invention can be prepared by the method shown below.

The above charge generating substance was mixed with O73 to 10 times the amount of polyarylate resin and a solvent using a homo zonizer, ultrasonic waves,
It is well dispersed by methods such as gall mills, vibrating tail mills, Zyde mills, attritor mills, and roll mills. Next, the silicone-based comb-shaped graft polymer according to the present invention and the charge transport material described above are dissolved and applied onto a substrate. The mixing ratio of the charge transport material and the polyarylate resin is 2:1 to 1:
It is about 2. Examples of solvents include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene, and chlorinated hydrocarbons such as chlorobenzene, chloroform, and carbon tetrachloride. used. When applying this solution, coating methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, and curtain coating can be used, and drying is carried out at 10°C to 200°C. , preferably L (can be carried out under blow drying or stationary drying at a temperature in the range of 20° C. to 150° C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours. Thickness of the photosensitive layer produced is about 5 to 20μ.

〔Example〕

Hereinafter, the present invention will be explained according to examples.

The silicone-based comb-shaped graft polymers (samples A & ~ O) used in the following examples were synthesized according to JP-A-58-167606 and JP-A-59-126478, which disclose a method for synthesizing comb-shaped graft polymers. This is what I did.

Specifically, the modified silicone synthesized by the above-mentioned synthesis method and a polymerizable unsaturated bond-containing monomer such as styrene or methyl methacrylate are combined with toluene in the presence of a radical polymerization initiator such as azobisisobutyronitrile. It can be obtained by solution polymerization in a solvent such as The reaction temperature is preferably 6
The reaction time is preferably 0 to 90°C and 10 to 25 hours. After the reaction is completed, the contents are poured into a large amount of methanol to precipitate the polymer, which is then dried to obtain the desired product. Its composition is shown in Table 1.

The structure of the synthesized silicone-based comb-shaped graft polymer is shown below as a representative example for samples A and H.

Sample b B, B2 Sample h 2B2 The polyarylate used in the present invention is synthesized from bisphenols represented by the general formula [v] and terephthalic acid chloride. Specifically, 1.0 mole of bisphenols was dissolved in 1 mole of sodium hydroxide aqueous solution, a surfactant was added, and the solution was stirred.While stirring, 1.0 mole of terephthalic acid chloride was dissolved in chloroform. Add the solution. After continued stirring.

The obtained emulsion is poured into acetone to precipitate a polymer, which is thoroughly washed with water and separated by F; after drying by heating, a white polymer is obtained.

Example 1 After dispersing 10 parts (parts by weight, the same applies hereinafter) of cutinku casein produced in a new sealant and 90 parts of water,
1 part of aqueous ammonia was added and dissolved. On the other hand, 3 parts of hydroxyglobil methylcellulose resin (trade name: Metrose 60SH50, manufactured by Shin-Etsu Chemical) was dissolved in 20 parts of water, and the two were then mixed to prepare a coating solution for an undercoat layer.

(7J) W i,c It was applied to an At cylinder of 80φ x 300m by dipping method, dried at 80°C for 10 minutes,
A subbing layer of 2 μJ7 was formed.

2 parts of C-copper phthalocyanine pigment as photoconductor 6-ff
'What kind of bisphenol is used in 2 VD's 111? 10 parts of a mortar resin synthesized according to the synthesis method of Real 1/-t and 1. ．． 60 parts of 2-U chloroethane was dispersed for 20 hours in a sand mill using φ Gazis beads. To this liquid, 0.2 part of silicone-based comb-shaped graft polymer of trial All was added as solid content. This dispersion solution was dip coated onto the undercoat layer, and
It was dried at 0° C. for 1 hour to form a 19 μm photoconductive layer. This is called Trial 1. Electrophotographic photoreceptors similarly prepared using the silicone comb-shaped graft polymer of sample Ab=o are designated as samples 2 to 15.

For comparison, a sample C was prepared in the same manner as above without adding the silicone comb-shaped graft polymer.

This is designated as sample 16.

These samples were charged with -5,5 kV and corona.

The durability of 100 sheets was evaluated using an electrophotographic process consisting of image exposure, dry toner development, toner transfer to plain paper, and cleaning with a urethane rubber blade. The results are shown in Table 2 below.

The evaluation environment was 32.5°C, RH 90°C.

Table 2 Example 2 In place of the polyarylate resin in Example 1.

Specific examples of general formula [V] 132, 116, 119, 120, 127゜1
The same results as in the case of the polyarylate resin of Example 1 were obtained even when each of the 4-birylylates synthesized using bisphenols such as 30.137 was used.

Example 3 3 parts of a disazo pigment having the following structural formula, 10 parts of polyarylate resin synthesized using bisphenol of specific example A116 of general formula (V:II), and 50 parts of monochlorobenzene were mixed in a sand mill apparatus using a 1φ glass beer r. It was dispersed for 20 hours.The silicone comb-shaped graft polymer of sample Aa was added as a solid content to this liquid.
10 parts of a hydrazone compound having the following structural formula were added and dissolved. This dispersion solution was prepared in Example 1. The photoconductive layer was applied by dip coating onto a substrate having an undercoat layer prepared in the same manner as described above, and dried at 100° C. for 1 hour to form a photoconductive layer of 19 μm. This is sample 17
shall be.

For comparison, a sample without the addition of silicone-based comb-shaped graft polymer was prepared in the same manner as in Section 1.

This is designated as sample 18.

The durability of these samples was evaluated under the same conditions as in Example 1. The results are shown in Table 3.

Table 3 Example 4 In place of the prearylate resin in Example 3.

Specific example of general formula [V] A111, 119, 120, 127-130゜1
Even when each polyarylate synthesized using bisphenols such as 32.137 was used, the same results as in the case of the polyarylate resin of Example 3 were obtained.

Comparative Example Sample 19 was prepared in the same manner as in Example 1, except that 1.0 part of silicone oil (trade name: KF 96, manufactured by Shin-Etsu Silicone Co., Ltd.) was used as a solid content in place of the silicone-based comb-shaped polymer. shall be.

Sample 20 was prepared in the same manner as in Example 3, except that 1.0 part of the silicone oil was used. Durability evaluation of these samples was carried out under the same conditions as in Examples 1 and 3, but the strength of the samples was markedly lowered, and the degree of strength was further increased by repeated copying. Further, when samples 19 and 20 were prepared and observed on the blade ridge, silicone oil had migrated to the surface layer and stood out in the form of a stain. On the other hand, in the sample to which the silicone-based comb-shaped graft polymer was added, no such change over time was observed, and the sample had the same appearance and characteristics as the initial sample.

Example 5 Next, regarding samples A 1 , 17 , 19 = 20 -
It was installed in an electrophotographic copying machine equipped with a 5.5 kV corona charger and subjected to an empty charging durability test of 10,000 sheets at room temperature and humidity, and was exposed to VD potential and 7.5 lux for seconds.
Fluctuations in L potential were measured. The results are shown in Table 4.

Table 4 10 samples were prepared by adding silicone oil as shown in the table above.
The vL fluctuation after 000 sheets durability is very large.

In contrast, it can be seen that the product of the present invention has an extremely stable potential during durability.

Example 6 Next, the samples 1, 5, 10, 16, 17, 18°19.
For No. 20, the frictional force between the urethane blade and the surface layer was measured. The results are shown in Table 5.

Table 5 *The friction force of friction crab sample 16 is set as the standard value 1.

Shown as relative values.

As shown in the table above, the present invention to which silicone-based comb-shaped polymer was added and the comparative sample to which silicone oil was added,
The frictional force is significantly reduced compared to the additive-free sample.

However, the comparative materials to which silicone oil was added had poor storage stability and potential stability during durability as described above.

In this way, the addition of a silicone-based comb-shaped graft polymer reduces the frictional force of the surface layer, improves cleaning performance, and prevents adhesion of toner, paper dust, etc. The combination with arylate resin has excellent durability, little increase in residual potential, and exhibits stable characteristics over a long period of time.

〔Effect of the invention〕

As is clear from the above, the electrophotographic photoreceptor of the present invention has excellent surface lubricity and mold releasability due to the combination of a specific silicone-based comb-shaped graft polymer with a polyarylate-based resin, and has extremely good cleaning properties. Moreover, it has excellent durability against repeated electrophotography, and high-quality images can always be obtained without accumulation of residual charge in repeated electrophotographic processes.

Claims (4)

[Claims] (1) General formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼ (I) (In the formula, R_1, R_2, R_3, R_4, R_5 represent an alkyl group or an aryl group that may have a substituent. , n indicates the average degree of polymerization) and/or general formula (II) ▲ Numerical formula, chemical formula, table, etc. ▼ (II) (In the formula, B_6 and R_7 are an alkyl group that may have a substituent or represents an aryl group, and n represents the average degree of polymerization) and at least has the general formula (III) ▲ mathematical formula, chemical formula, table, etc. ▼ (in the formula, R_8 is a hydrogen atom or has a substituent R_9 represents an optionally substituted alkyl group, aryl group, or aralkyl group; R_9 represents an optionally substituted alkyl group or aryl group; X represents a halogen atom or alkoxy group; m represents 0 or 1; When m = 0, l represents an integer of 0 to 2, and when m = 1, l represents 2. k represents an integer of 1 to 3. An electrophotographic photoreceptor characterized in that a silicone-based comb-shaped graft polymer, which is a copolymer with a saturated bond-containing compound, and a polyarylate-based resin are contained at least in a layer furthest away from a substrate. (2) The electrophotographic photoreceptor according to claim (1), which has a photosensitive layer as the layer furthest away from the substrate. (3) The photosensitive layer furthest away from the substrate is a single layer containing a charge generating substance and a charge transporting substance.
2) The electrophotographic photoreceptor described in section 2). (4) One of claims (1) to (3), wherein the content of the silicone-based comb-shaped graft polymer in the layer furthest from the substrate is within the range of 0.01 to 10% by weight. The electrophotographic photoreceptor described in .