JPH0547106B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an electrophotographic photoreceptor that can be widely used in the electrophotographic field such as electrophotographic copying machines, laser beam printers, CRT printers, and electrophotographic engraving systems. [Prior Art] 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 phthalocyanine have advantages over inorganic photoconductive materials, such as non-pollution and high productivity, but their low sensitivity has made it difficult to put them into practical use. For this reason, several sensitization methods have been proposed, and the use of a functionally separated photoreceptor in which a charge generation layer and a charge transport layer are laminated is known and put into practical use as an effective method. Of course, electrophotographic photoreceptors have
It is required to have predetermined sensitivity, electrical properties, and further optical properties depending on the electrophotographic process to which it is 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 reductions in sensitivity and potential, increases in residual potential due to deterioration due to ozone generated during corona charging, and the occurrence of surface friction and scratches due to rubbing. In addition, 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. There is a need to form a photoreceptor surface that is not easily contaminated by these substances and is easily removed. Conventionally, various methods have been proposed to solve the above-mentioned drawbacks. As one such method, the use of polycarbonate resin as a binder for the surface layer is being considered. Since polycarbonate resin has good abrasion resistance, a photoreceptor using polycarbonate resin as a binder in the surface layer has significantly improved durability against external mechanical forces. However, since the amount of abrasion of the surface layer decreases, cleaning performance of attached paper dust and residual toner becomes poor, and conversely, this causes deterioration of 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 powder and residual toner to adhere to it and making it easier to clean. As a means for this, there is a method of adding a general coating film surface modifier, ie, a leveling agent, silicone oil, etc., and a method of dispersing Teflon powder. However, these common surface modifiers
Due to its poor compatibility with the components of the coating liquid to which it is added, it migrates or oozes out onto the surface layer during long-term use, making it difficult to maintain its effect. In addition, when the surface layer itself forms a photoconductive layer, the surface modifier has poor compatibility with the photoconductive substance, and is likely to become a trap for carrier movement due to photogeneration, resulting in repeated electrophotographic processes. There was a tendency for the residual charge to increase. On the other hand, problems such as poor dispersibility, decreased transparency, and carrier traps occurred in the surface layer in which Teflon or the like was dispersed. [Problems to be Solved by the Invention] The present invention solves the conventional problems and provides excellent surface lubricity and mold releasability, extremely good cleaning properties, excellent repeat durability, and The purpose is to provide an electrophotographic photoreceptor with less damage. 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. [Means and effects for solving the problems] The electrophotographic photoreceptor of the present invention, which was discovered as a means to achieve the above object of the present invention, contains silicone side chains and ethylene-based side chains at least in the layer furthest from the substrate. It is characterized by containing a comb-shaped graft polymer having a main chain of (hereinafter also simply referred to as a silicone-based comb-shaped graft polymer) and a polycarbonate-based resin. That is, the present invention provides at least the following general formula () and general formula () in the layer farthest from the substrate.
Alternatively, it can be obtained by copolymerizing a modified silicone, which is a condensation reaction product of a silicone represented by the general formula () or at least a compound represented by the following general formula (), with a polymerizable ethylene compound. a comb-shaped graft polymer having a silicone-based side chain and an ethylene-based main chain;
The electrophotographic photoreceptor is characterized by containing a polycarbonate resin. General formula () In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ represent an alkyl group or an aryl group which may have a substituent, and n represents an average degree of polymerization. General formula () In the formula, R ₆ and R ₇ represent an alkyl group or an aryl group which may have a substituent, and n represents an average degree of polymerization. General formula () In the formula, R ₈ is a hydrogen atom, an alkyl group which may have a substituent, an aryl group or an aralkyl group,
_R9 represents an alkyl group or an aryl group which may have a substituent, X represents a halogen atom or an alkoxy group which may have a substituent, k is 0 or 1, and l is k= In the case of 0, it is an integer of 0 to 2; in the case of k=1, it is 2; and m is an integer of 1 to 3. The photosensitive layer has a photosensitive layer and a surface layer of a non-photosensitive layer as constituent components, and the layer farthest from the substrate is the non-photosensitive surface layer, and the photosensitive layer has a charge generation layer and a charge transporting layer. The layer having a laminated structure with a charge generating layer and a charge transport layer and the layer furthest from the substrate is a photosensitive layer, and the layer having a laminated structure of a charge generating layer and a charge transporting layer as a component and being farthest from the substrate is the photosensitive layer. The charge transport layer or the charge generation layer may include the constituent requirements that the content of the silicone comb-shaped graft polymer in the layer furthest from the substrate is within the range of 0.01 to 10% by weight. . As is known in the art, an electrophotographic photoreceptor has a photosensitive layer on a substrate, and optionally a non-photosensitive subbing layer, an intermediate layer, a surface layer, etc., and the photosensitive layer includes There are those that have a single layer structure and those that have a laminated structure of a charge generation layer and a charge transport layer. The present invention can be applied to all of these known types of electrophotographic photoreceptors, and at least the layer furthest away from the substrate (hereinafter referred to as the surface layer of the present invention) may be, for example, the non-photosensitive surface layer, a single layer, etc. The silicone-based comb-shaped graft polymer and the polycarbonate-based resin are contained in the charge-generating layer or the charge-transporting layer in the photosensitive layer of the structure or the photosensitive layer of the laminated structure. The silicone-based comb-shaped graft polymer used in the present invention has the general formula () and the general formula (),
Or one obtained by copolymerizing a modified silicone, which is a condensation reaction product of general formula () or silicone represented by general formula (), and at least a compound represented by general formula (), and a compound having a polymerizable functional group. It has a structure in which silicone-containing side chain groups are bonded to the main chain in a branched manner. The compound represented by the above general formula will be explained in detail below. General formula () General formula () General formula () In the general formulas () and (),
R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ are methyl,
an alkyl group such as ethyl, propyl, butyl, or an aryl group such as phenyl, naphthyl,
It may have a substituent such as a halogen atom or a lower alkyl group. Preferred are methyl group and phenyl group. n indicates an average degree of polymerization, and is in the range of 1 to 1000, preferably in the range of 10 to 500. In the general formula (), R ₈ is a hydrogen atom or an alkyl group such as methyl, ethyl, propyl, butyl, an aryl group such as phenyl or naphthyl, or an aralkyl group such as benzyl, and these groups are halogen atoms, lower alkyl It may have a substituent such as a group. Preferred is a hydrogen atom or a methyl group. R ₉ is an alkyl group such as methyl, ethyl, propyl, butyl, or an aryl group such as phenyl or naphthyl, and may have a substituent such as a halogen atom. Preferred are methyl group and phenyl group. X is a halogen atom such as fluorine, chlorine, bromine, or iodine, or an alkoxy group such as methoxy, ethoxy, propoxy, or butoxy, and may have a substituent such as a lower alkoxy group. Preferred are methoxy group, ethoxy group, and 2-methoxy-ethoxy group. k is 0 or 1, l is an integer from 0 to 2 when k=0, 2 when k=1, and m
is an integer from 1 to 3. Next, typical examples of the compounds represented by the above general formula will be listed. Specific examples of compounds represented by general formula () Specific examples of compounds represented by general formula ()

[Table] ｜
C ₄ H ₉

【table】

【table】 Specific examples of compounds represented by general formula ()

[Table] ‖ ｜

O
OCH ₃

[Table] ‖ ｜

O
Cl

[Table] ‖ ｜

O.C.
_H3

[Table] ‖ ｜

O.C.
_H3

[Table] ‖ ｜

OO
CH ₂ CH ₂ OCH ₃

【table】

[Table] The condensation reaction between general formula () and general formula (), or silicone represented by general formula () or general formula (), and at least a compound represented by general formula () is carried out according to ordinary organic chemical reaction procedures. The reaction molar ratio and reaction conditions were appropriately controlled in accordance with the description in JP-A-58-167606 and JP-A-59-126478, which disclose a method for synthesizing a comb-shaped graft polymer that proceeds extremely smoothly. By doing so, a stable modified silicone can be obtained. Compounds with polymerizable functional groups include macromonomers consisting of polymerizable monomers that do not have silicon atoms or relatively low molecular weight monomers with a molecular weight of about 1,000 to 10,000 that have a polymerizable functional group at the end. Examples include. 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 organic acids such as vinyl acetate. vinyl ester, styrene,
Styrene substitutes and other vinyl aromatic compounds such as vinylpyridine and vinylnaphthalene, acrylic acid, methacrylic acid and their esters, amides and derivatives of acrylic acid, including acrylonitrile, N-vinylcarbazole, N-vinylpyrrolidone and N-
N-vinyl compounds such as vinyl caprolactam,
Examples include vinyl silicon compounds such as vinyltriethoxysilane. Disubstituted ethylenes can also be used, examples of which include vinylidene fluoride, vinylidene chloride, and maleic anhydride, maleic acid and fumaric acid. In particular, acrylic esters, methacrylic esters, styrene, and the like are preferable because of their affinity with polypolycarbonate resins. Further, the monomers can be used alone or in combination of two or more types. As a polymerization method for silicone-based comb-shaped graft polymers, radical polymerization and ionic polymerization such as solution polymerization, suspension polymerization, and bulk polymerization can be applied, but radical polymerization by solution polymerization is simple and preferred. The copolymerization ratio is preferably 5 to 90% by weight, more preferably 10 to 70% by weight as the silicone monomer content. The number average molecular weight of the obtained polymer is preferably 500 to 100,000, particularly preferably 1,000 to 50,000. Since the silicone-based comb-shaped graft polymer in the present invention has such a structure, it can be used as a binder resin for forming the surface layer in the present invention.
It has excellent compatibility with coating solutions containing polycarbonate resins, and therefore the resulting coating film has good transparency and does not migrate or seep onto the surface layer of the present invention. It has a long-lasting effect, and since the silicone-containing branch portion has excellent interfacial migration properties, surface modification can be achieved by adding a small amount. Furthermore, even if this additive is contained on the surface, there is no accumulation of residual charge due to repeated electrophotographic processes, and stable charging characteristics can be obtained. The amount of silicone graft polymer added is suitably 0.01 to 10%, particularly preferably 0.05 to 5%, based on the solid weight of the surface layer. If the amount added is less than 0.01, a sufficient surface modification effect will not 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, so that the resin, which is the main component of the surface layer, will be present. or may cause whitening due to compatibility issues with photoconductive substances.
Residual charge buildup occurs during repeated electrophotographic processes. The polycarbonate resin used in the present invention contains a linear polymer containing one or more repeating units represented by the following general formula (). General formula () In the formula, R ₁₀ and R ₁₁ are each a hydrogen atom,
It represents an alkyl group such as methyl, ethyl, propyl, butyl, or an aryl group such as phenyl or naphthyl, and may have a substituent such as a halogen atom or a lower alkyl group. Alternatively, R ₁₀ and R ₁₁ may form a cyclic structure together with the bonded carbon atoms,
Specific examples include a cyclohexyl ring and a lactone structure. X ₁ , X ₂ , X ₃ and X ₄ are each a hydrogen atom,
Indicates halogen 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. . The polycarbonate resin may be one or two diol compounds represented by the following general formula.
It can be obtained by general polycarbonate resin synthesis methods such as the phosgene method using at least one species. General formula () In the formula, R ₁₀ , R ₁₁ , X ₁ , X ₂ , X ₃ and X ₄ have the same meanings as in the general formula (). Next, typical specific examples of the compound represented by the general formula () are shown below. The present invention will be described in detail below, taking as an example the case where the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the surface layer according to the present invention is the charge transport layer.
When producing the electrophotographic photoreceptor of the present invention, the substrate may be metal such as aluminum or stainless steel;
Cylindrical cylinders or films of paper, plastic, etc. are used. 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 adhesion of the photosensitive layer, improve coating properties, protect the substrate, cover defects on the substrate, improve charge injection from the substrate, protect the photosensitive layer from electrical breakdown, etc. . The material for the undercoat layer is polyvinyl alcohol,
Known examples include poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, copolymerized nylon, glue, and gelatin. These are each dissolved in a suitable solvent and applied onto the substrate. The film thickness is
It is about 0.2 to 2μ. In the functionally separated photoreceptor, selenium, selenium-tellurium, pyrylium dyes, thiopyrylium dyes, phthalocyanine dyes, anthorone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, and azo pigments are used as charge-generating substances. Pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine, quinocyanine, or amorphous silicon described in JP-A-54-143645 can be used, and charge transport substances include pyrene, N-ethylcarbazole, and N-isopropyl. Carbazole, N-methyl-N-phenylhydrazino-3-methylidene-9
-Ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N,N-diphenylhydra Dino-3-methylidene-10-ethylphenoxazine, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone, P-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, P-pyrrolidinobenzaldehyde-N , N-diphenylhydrazone, 1,3,3-trimethylindolenine-ω-
Aldehyde-N,N-diphenylhydrazone, P
Hydrazones such as -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)pyrazoline, 1-[6-methoxypyridyl
(2)]-3-(P-diethylaminostyryl)-5-
(P-diethylaminophenylpyrazoline, 1-
[pyridyl(3)]-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[lepidyl(2)]-3-(P-diethylaminostyryl)-5-(P- diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3-(P-
diethylaminostyryl)-4-methyl-5-(P
-diethylaminophenyl)pyrazoline, 1-
[Pyridyl(2)]-3-(α-Methyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-phenyl-3-(P-diethylaminostyryl)-4-methyl-5- (P-
diethylaminophenyl) pyrazoline, 1-phenyl-3-(α-benzyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)
Pyrazolines such as pyrazoline and spiropyrazoline, 2-(P-diethylaminostyryl)-6-diethylaminobenzoxazole, 2-(P-diethylaminophenyl)-4-(P-dimethylaminophenyl)-5-(2-chlorophenyl) ) Oxazole compounds such as oxazole, 2-(P-
thiazole compounds such as (diethylaminostyryl)-6-diethylaminobenzthiazole, bis(4-diethylamino-2-methylphenyl)
Triarylmethane compounds such as phenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl)heptane, 1,1,2,
2-tetrakis(4-N,N-dimethylamino-
Polyarylalkanes such as 2-methylphenyl)ethane and the like can be used. The charge generation layer contains the above charge generation substance in an amount of 0.3 to 4
It is formed by thoroughly dispersing, coating, and drying together with double the amount of binder resin and solvent using a homogenizer, ultrasonic wave, ball mill, vibrating ball mill, sand mill, attritor, roll mill, etc. Its thickness is about 0.1 to 1μ. The charge transport layer is formed by dissolving the polycarbonate resin and silicone comb-shaped graft polymer, which are essential in the present invention, in a solvent together with a charge transport material as a binder, and coating the mixture on the charge generation layer. The mixing ratio of the charge transport material and the binder resin is 2:
The ratio is about 1 to 1:2. Examples of solvents used 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. It will be done. When applying this solution, coating methods such as dip coating, spinner coating, bead coating, blade coating, and curtain coating can be used, and drying is carried out at 10 to 200°C, preferably 20 to 150°C.
The drying can be carried out at a temperature in the range of 0.degree. C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours under blow drying or stationary drying. The thickness of the generated charge transport layer is 5 to 20μ
That's about it. Further, the charge transport layer can contain various additives. Additives include diphenyl, diphenyl chloride, O-terphenyl, P-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dilaurylthiopropionate, 3,5- Examples include dinitrosalicylic acid and various fluorocarbons. On the other hand, in a functionally separated photoreceptor having a charge generation layer as a surface layer, the polycarbonate resin of the present invention and a silicone comb-shaped graft polymer can be used as a binder for a charge generation substance. Furthermore, even in a single-layer type photoreceptor in which the photosensitive layer is a surface layer defined in the present invention, a polycarbonate resin and a silicone comb-shaped graft polymer can be used as a binder in the photosensitive layer. When a non-photosensitive surface is provided as a protective layer, for example, the polycarbonate resin and the silicone comb-shaped graft polymer can be used as protective film forming materials. Hereinafter, the present invention will be explained according to examples. The silicone-based comb-shaped graft polymers (samples (a) to (o)) used in the examples are those disclosed in JP-A-58-167606 and JP-A-59-126478, which disclose a method for synthesizing comb-shaped graft polymers. It was synthesized according to the polymerization method described in the publication, and its composition is listed below.

[Table] Sample Comonomer Modified silicone monomer content (a) Methyl methacrylate 20% by weight (b) Styrene/Methyl methacrylate 10 〃 (c) Styrene 30 〃 (d) Methyl methacrylate 30 〃 (e) Styrene 15 (f) Methyl methacrylate 25 (g) Methyl methacrylate 30 (h) Styrene 20 (i) Styrene 20 (i) Styrene/Methyl methacrylate 30 (k) Methyl methacrylate 30 (l) Methyl methacrylate 15 (m) Styrene 25 (N) Methyl methacrylate 20 (o) Styrene 25 The structures of the synthesized silicone comb-shaped graft polymers are shown below as representative examples for sample (b) and sample (h). Sample (b) n: average 30, p ₁ , q ₁ ; positive integer A ₁ /B ₁ ; 20/80 (weight ratio) Sample (h) n: average 30, p ₂ , q ₂ ; positive integer A ₂ /B ₂ ; 30/70 (weight ratio) The polycarbonate resin has the above general formula ()
It is synthesized by the reaction between the compound shown in and phosgene. Specifically, 0.15 mol of bisphenols and phenol were added to a 500 ml separable flask with a stirrer.
Add 0.353g, 16.8g of NaOH, and 238ml of water. 50
After heating and dissolving at ℃, cool to 25℃ and dissolve in methylene chloride.
Add 147ml. Then, phosgene was added while stirring at 25°C.
Mix 19.1g over 60 minutes. Thereafter, 0.0342 g of trimethylbenzylammonium chloride, 4.5 g of NaOH, and 30 ml of water were added, and polymerization was carried out at 25° C. for 4.5 hours with stirring. After the polymerization is completed, dilute with 360 ml of methylene chloride, wash with hydrochloric acid to make it weakly acidic, and then wash with water 5 times. The polymer solution is poured into methanol to solidify and dried at 100°C and 1 m.Hg for 15 hours to obtain a white polymer. Example 1 10 parts (parts by weight, the same applies hereinafter) of New Zealand-produced lacquer casein were weighed out, dispersed in 90 parts of water, and then dissolved in 1 part of ammonia water.
Separately, 3 parts of hydroxypropyl methylcellulose resin (trade name: Metrose 60SH50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 20 parts of water, and the two were then mixed to prepare a coating solution for the undercoat layer. Apply this coating liquid to 80φ×300mm.
80% by dipping method onto an aluminum cylinder.
It was dried at ℃ for 10 minutes to form a 2μ thick subbing layer.
Next, 10 parts of a disazo pigment with the following structure, 6 parts of cellulose acetate butyrate resin (trade name: CAB-381, manufactured by Eastman Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed for 20 hours using a sand mill device using 1φ glass beads. Add 100 parts of methyl ethyl ketone to this dispersion, apply it on the undercoat layer by dip coating, heat dry at 100°C for 10 minutes, and apply 0.1g/
A charge generation layer was provided with a coating weight of m ² . Next, 10 parts of a hydrazone compound with the following structure, Using the compound of the specific example (111) of the general formula (), 10 parts of a polycarbonate resin synthesized according to the synthesis method for the polycarbonate resin described above was dissolved in 100 parts of 1,2-dichloroethane. To this liquid, 0.2 part of the silicone comb-shaped graft polymer of the sample (a) was added as a solid content. This solution was applied onto the charge generation layer and dried with hot air at 100° C. for 1 hour to form a charge transport layer with a thickness of 16 μm. This is designated as sample 1. Electrophotographic photoreceptors similarly prepared using the silicone comb-shaped graft polymers of Samples (b) to (o) are designated as Samples 2 to 15. For comparison, a sample 1 without the silicone comb-shaped graft polymer was prepared in the same manner as above, and this was designated as comparative sample 1. The durability of these samples was evaluated on 30,000 sheets using an electrophotographic process consisting of -5.5 kV, corona charging, image exposure, dry toner development, toner transfer to plain paper, and cleaning with a urethane rubber blade. The results are shown below. Evaluation environment: 32.5°C, RH 90% For samples 1 to 15, stable high-quality images were obtained up to 30,000 sheets. In Comparative Sample 1, image deletion occurred after about 500 copies were made. Example 2 10 parts of the hydrazone compound used in Example 1 and 10 parts of a polycarbonate resin synthesized using the compound of specific example (116) of general formula () were dissolved in 80 parts of monochlorobenzene. Add the silicone comb-shaped graft polymer of sample (h) to this liquid as a solid content.
Added 0.4 parts. This solution was applied onto a substrate coated up to the charge generation layer prepared in the same manner as in Example 1, and dried with hot air at 100° C. for 1 hour to form a charge transport layer with a thickness of 16 μm. This is designated as sample 16. For comparison, a product without the silicone comb-shaped graft polymer was prepared in the same manner as above.
This will be referred to as comparative sample 2. The durability of these samples was evaluated under the same conditions as in Example 1. The results are shown below. For sample 16, stable high-quality images were obtained up to 30,000 sheets. In comparative sample 2, image deletion occurred after about 700 copies. Example 3 An aluminum cylinder of 80φ x 300mm was used as a base, and polyamide resin (trade name Amiran) was applied to this
A 5% methanol solution of CN-8000 (manufactured by Toray Industries, Inc.) was applied by dipping to form a 1 μm thick subbing layer. Next, 12 parts of a pyrazoline compound with the following structure, 10 parts of the polycarbonate resin synthesized in Example 2 was dissolved in 60 parts of monochlorobenzene. This solution was dip-coated onto the undercoat layer and dried at 100°C for 1 hour to form a 14μ layer of charge transport layer. Next, the same bisazo pigment used in Example 1 was used.
10 parts were added to 100 parts of a 10% by weight 1,2-dichloroethane solution of the polycarbonate resin synthesized in Example 1, and dispersed for 20 hours using a sand mill device using glass beads. One part of the silicone comb-shaped graft polymer of sample (c) was added as a solid content to this dispersion. This solution was pushed up onto the charge transport layer and applied for 20 minutes at 100℃.
It was dried for minutes to form a charge generation layer 2μ thick.
This is designated as sample 17. For comparison, a sample without the silicone comb-shaped graft polymer was prepared in the same manner as above, and this was designated as Comparative Sample 3. The sample thus obtained was charged with +5.6kV corona.
It was installed in an electrophotographic copying machine that has image exposure, dry toner development, toner transfer to plain paper, and cleaning steps using a urethane rubber blade, and the durability was evaluated on 3000 copies under an environment of 32.5°C and RH 90%. For sample 17, high-quality images were obtained up to 3000 seconds of copying. In Comparative Sample 3, the toner was fused onto the surface layer after 300 copies, and many black spots appeared on the image. Example 4 10 parts of the same hydrazone compound used in Example 1 and 10 parts of the polycarbonate resin synthesized in Example 2
1 part was dissolved in 60 parts of monochlorobenzene. This solution was applied by dip coating onto the undercoat layer formed in the same manner as in Example 3, and dried at 100°C for 1 hour.
A charge transport layer of 15μ was formed. Next, 10 parts of the same bisazo pigment used in Example 3 was added to 10 parts of the polycarbonate resin synthesized in Example 2.
Added to 100 parts of a monochlorobenzene solution of % by weight,
Dispersion was carried out for 20 hours using a sand mill device using glass beads. One part of the silicone comb-shaped graft polymer of sample (j) was added as a solid content to this dispersion.
This solution is pushed up and applied onto the charge transport layer.
It was dried at 100° C. for 20 minutes to form a charge generation layer with a thickness of 2.5 μm. This is designated as sample 18. For comparison, a sample without the silicone comb-shaped graft polymer was prepared in the same manner as above.
This will be referred to as comparative sample 4. The durability of these samples was evaluated under the same conditions as in Example 3. For sample 18, high-quality images were obtained up to 3000 copies. In comparative sample 4, image deletion occurred after about 500 copies were made. Example 5 Two parts of the polycarbonate resin synthesized in Example 1 were dissolved in 100 parts of 1,2-dichloroethane. To this solution, 0.15 of the silicone-based comb-shaped graft polymer of sample (e) was added in terms of solid content. This solution was spray-coated onto an electrophotographic photoreceptor prepared in the same manner as Sample 6 of Example 1, and dried at 100° C. for 5 minutes to form a 0.5 μm protective layer. This is designated as sample 19. Similarly, 2 parts of the polycarbonate resin synthesized in Example 2 was dissolved in 100 parts of monochlorobenzene, and 0.5 part of the silicone-based comb-shaped graft polymer of sample (i) was added in solid content. This solution was used in Example 2.
It was spray-coated onto an electrophotographic photoreceptor prepared in the same manner as Comparison Sample 2, and dried at 100°C for 5 minutes.
A protective layer of 0.4μ was formed. This is designated as sample 20. These samples were treated under the same conditions as in Example 1.
Durability evaluation was conducted on 5000 sheets. High-quality images were obtained for both samples 19 and 20 up to 5,000 copies. Comparative example: Instead of silicone-based comb-shaped graft polymer,
Comparative sample 5 is a sample prepared in the same manner as in Example 1, except that 1 part of silicone oil (trade name KF96, manufactured by Shin-Etsu Silicone Co., Ltd.) was used as a solid content. Similarly, a sample prepared in the same manner as in Example 4, except for using 1 part of the above silicone oil, was designated as Comparative Sample 6. The durability of these samples was evaluated under the same conditions as in Example 3, but the background fog was significant, and the degree of fog increased with repeated copying. Furthermore, when Comparative Samples 5 and 6 were observed one month after their preparation, the silicone oil had migrated to the surface layer and stood out in the form of a stain. On the other hand, samples 1 to 20 to which silicone-based comb-shaped graft polymers were added showed no such change over time, and exhibited the same appearance and characteristics as the initial stage. Example 6 (Measurement of potential characteristics) Next, regarding samples 2, 16 and comparative sample 5, -
An electrophotographic copying machine equipped with a 5.5kV corona charger was used to carry out an empty charging durability test of 30,000 sheets at room temperature and humidity, and the V _D potential and 7.5 Lux were tested. Fluctuations in the V _L potential after second exposure were measured. The results are shown below.

[Table] As shown in the table above, the variation in _VL after 30,000 sheets of the sample to which silicone oil was added was extremely large.
In contrast, it can be seen that the photoreceptor of the present invention has an extremely stable potential during durability. Example 7 (Measurement of potential characteristics) Next, regarding sample 18 and comparative sample 6, +
An electrophotographic copying machine equipped with a 5.5kV corona charger was used to carry out an empty charging durability test of 3,000 sheets at room temperature and humidity, and the V _D potential and 7.5 Lux. Fluctuations in the V _L potential after second exposure were measured. The results are shown below.

[Table] As shown in the table above, the _VL fluctuation of the sample to which silicone oil was added is extremely large after 3,000 sheets of durability.
In contrast, it can be seen that the photoreceptor of the present invention has an extremely stable potential during durability. Example 8 (Friction force test) Next, the friction force between the urethane blade and the surface layer was measured for the sample and the comparative sample. The results are shown below. (Frictional force is expressed as a relative value, with the frictional force of comparative sample 2 as reference value 1.)

【table】

[Table] As shown in the table above, the photoreceptor of the present invention to which a silicone-based comb-shaped graft polymer was added and the comparative sample to which silicone oil was added had significantly reduced frictional force compared to the additive-free sample. However, the comparative sample to which silicone oil was added had poor storage stability and potential stability during durability as described above. Example 9 In place of the polycarbonate resin used in Example 1, specific examples of the general formula (115), (119),
Although each polycarbonate resin synthesized using compounds such as (120), (127), (130), (132), and (137) was used, the same results as in the case of the polycarbonate resin of Example 1 were obtained. It was done. By adding the silicone-based comb-shaped graft polymer in this manner, the frictional force of the surface layer is reduced, and the cleaning performance is improved and it is difficult for deposits such as toner and paper dust to stick to the surface layer. In particular, the combination with polycarbonate resin has excellent durability, little increase in residual potential, and exhibits stable characteristics over a long period of time. [Effects of the Invention] The electrophotographic photoreceptor of the present invention has excellent surface lubricity and mold release properties, and 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 (1)

[Claims] 1 At least in the layer farthest from the substrate, silicone represented by the following general formula () and general formula (), or the following general formula () or general formula (), and at least a silicone represented by the following general formula (). A comb-shaped graft polymer having a silicone side chain and an ethylene main chain obtained by copolymerizing a modified silicone, which is a condensation reaction product with the compound shown, and a polymerizable ethylene compound, and a polycarbonate resin. An electrophotographic photoreceptor characterized by containing. General formula () In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ represent an alkyl group or an aryl group which may have a substituent, and n represents an average degree of polymerization. General formula () In the formula, R ₆ and R ₇ represent an alkyl group or an aryl group which may have a substituent, and n represents an average degree of polymerization. General formula () In the formula, R ₈ is a hydrogen atom, an alkyl group which may have a substituent, an aryl group or an aralkyl group,
_R9 represents an alkyl group or an aryl group which may have a substituent, X represents a halogen atom or an alkoxy group which may have a substituent, k is 0 or 1, and l is k= In the case of 0, it is an integer of 0 to 2; in the case of k=1, it is 2; and m is an integer of 1 to 3. 2. The electrophotographic photoreceptor according to claim 1, which comprises a photosensitive layer and a non-photosensitive surface layer as constituent components, and the non-photosensitive surface layer is the layer that is furthest away from the substrate. 3. The electrophotographic photoreceptor according to claim 2, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer. 4. The electrophotographic photoreceptor according to claim 1, wherein the layer furthest away from the substrate is a photosensitive layer. 5. The electrophotographic photoreceptor according to claim 1, which has as a component a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer, and the layer furthest away from the substrate is the charge transport layer. . 6. The electrophotographic photoreceptor according to claim 1, which comprises as a component a photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer, and the charge generation layer is the layer furthest away from the substrate. 7. Claims 1 to 6, wherein the content of the silicone 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 according to item 1.