JPH10171135A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an electrophotographic photoreceptor excellent in wear resistance at the time of repetitive use without deteriorating its characteristics or affecting image characteristics by adding a very large amt. of silicone oil. SOLUTION: When at least a photosensitive layer is formed on an electrically conductive substrate to obtain an electrophotographic photoreceptor, silicone oil compatible with the constituent materials of the photosensitive layer is added to the layer by an amt. exceeding the compatible limit. It is preferable that the photosensitive layer has a laminated structure consisting of an electric charge generating layer and an electric charge transferring layer and silicone oil is added to the electric charge transferring layer. At the time when the silicone oil deposits in the layer, the size of particles or mist of the silicone oil is preferably <=1μm diameter and the ratio between the size and the thickness of the layer is preferably <1/20. It is preferable that silicone oil is further used in a protective layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having excellent durability. This electrophotographic photoreceptor is suitably used for copying machines, laser printers, laser facsimile machines and the like.

[0002]

2. Description of the Related Art As an electrophotographic method, the Carlson process and various deformation processes thereof are known, and are widely used in copiers and printers. Among the photoreceptors used in such an electrophotographic method, those using an organic photosensitive material have recently begun to be used because of their advantages such as low cost, mass productivity, and no pollution.

[0003] Organic electrophotographic photoreceptors include a photoconductive resin represented by polyvinyl carbazole (PVK), P
VK-TNF (2,4,7-trinitrofluorenone)
A charge-transfer complex type represented by, a pigment dispersion type represented by a phthalocyanine-binder, a function-separated type photoconductor using a combination of a charge-generating substance and a charge-transporting substance, and the like are known. Photoreceptors are receiving attention.

The mechanism of the formation of an electrostatic latent image in the photoreceptor of the function separation type is as follows. When the photoreceptor is charged and irradiated with light, the light passes through a transparent charge transport layer and is charged by a charge generating substance in the charge generating layer. The absorbed charge-generating substance, which has absorbed light, generates charge carriers, which are injected into the charge-transporting layer, move in the charge-transporting layer in accordance with the electric field generated by the charging, and charge the photoreceptor surface. The latent image is formed by neutralization. In a function-separated type photoreceptor, a charge transport material having absorption mainly in an ultraviolet portion,
It is known and useful to use it in combination with a charge generating substance having absorption mainly in the visible region.

Many charge transport materials have been developed as low molecular weight compounds. However, since low molecular weight compounds alone do not have a film-forming property, they are usually used after being dispersed and mixed with an inert polymer. However, the charge transport layer composed of a low-molecular charge transport material and an inert polymer is generally soft, and has a drawback that the Carlson process easily causes film shaving due to repeated use.

[0006] In recent years, there has been remarkable progress in the electrophotographic process using the above-mentioned photoreceptor, and various improvements have been made to the conventional Carlson process. For example, an improvement in the cleaning method for leaving no copy history (Japanese Patent Application Laid-Open No. 58-102273) and an improvement in the charging method for reducing the amount of ozone generated (Japanese Patent Application Laid-Open No.
6-104351, JP-A-57-178267, JP-A-58-40566, and JP-A-58-1
39156, JP-A-58-150975,
JP-A-63-149669, and the like, and improvement of a transfer system for improving image quality (JP-A-5-45916,
JP-A-7-152217).
The quality of the image output from the electrophotographic process is surely improved by such improvements. However, as a result, it is certain that the number of contact members with the photoconductor in the electrophotographic process has increased, and it is no exaggeration to say that the demand for the improvement of the wear resistance of the photoconductor has increased.

As a method for solving such a defect, a technique of providing a protective layer on the surface of a photoreceptor is known. Specifically, a method of providing an organic film on the surface of the photosensitive layer (Japanese Patent Publication No. 38-14466), a method of providing an inorganic oxide (Japanese Patent Publication No. 43-14517), providing an adhesive layer, and then forming an insulating layer A-Si layer, a-Si: N: H layer, a-Si: O: H by a method of laminating (Japanese Patent Publication No. 43-27591), a plasma CVD method, a photo CVD method or the like.
A method of laminating layers (Japanese Patent Laid-Open No. 57-179598,
JP-A-59-58437).
However, the protective layer has an electrophotographic high resistance (10 ¹⁴ Ω).
· Cm or more), there is a problem of an increase in residual potential, accumulation during repeated use, and the like, which is not practically preferable.

As a technique for compensating for the above-mentioned disadvantages, a method of forming a protective layer as a photoconductive layer (JP-A-48-38427, JP-A-49-10258, JP-A-43-16198, U.S. Pat. No. 2,901,348), a method of adding a charge transfer agent represented by a dye or a Lewis acid to the protective layer (JP-A-44-834, JP-A-53-133).
444) or a method of controlling the resistance of a protective layer by adding fine particles of a metal or metal oxide (JP-A-53-3).
No. 338) has been proposed. However, in such a case, light is absorbed by the protective layer, and the amount of light reaching the photoconductive layer is reduced, resulting in a problem that the sensitivity of the electrophotographic photosensitive member is reduced.

From such a viewpoint, Japanese Patent Application Laid-Open No. 57-308
No. 46, the average particle size is 0.3 μm.
There is a method of dispersing the following metal oxide particles as a resistance control agent in a surface protective layer to make them substantially transparent to visible light. The electrophotographic photoreceptor having this surface layer has less decrease in sensitivity and increases the mechanical strength of the surface protective layer,
The durability is improved. However, when this photoreceptor is incorporated in an actual copying machine, there is a disadvantage that a residual potential is generated and an abnormal image such as a background stain is generated on the image. This residual potential is generated by residual charges accumulated on the surface protective layer, and increases remarkably particularly at low temperature and low humidity.

In view of the above, a method has been proposed in which a low-molecular charge transporting substance and a metal or metal oxide fine powder are added to a protective layer (Japanese Patent Laid-Open No. 4-281461). Certainly, although the addition of a low-molecular charge transport material to the protective layer has a remarkable effect on the reduction of the residual potential, the disadvantage that the surface protective layer is more often scraped by repeated use than when no additive is added. Had not reached a satisfactory level.

On the other hand, it has been proposed to add methylphenyl silicone oil to the charge transport layer in order to improve the surface properties of the photoreceptor (JP-A-57-5050).
According to this, methylphenyl silicone oil is added to the charge transport layer coating solution in an amount of 0.001 to 0.
It is said that by adding 5% by weight, coating film defects (orange peel, pinhole, streak, crater) and the like can be reduced. In this case, too, the silicone oil is added in such a small amount that the coating film does not become cloudy, and a continuous effect cannot be obtained much.

JP-A-53-29726 proposes that a silicone oil is added not to the photosensitive layer but to the insulating layer thereon, and for a completely different purpose. According to this, the addition of silicone oil to the insulating layer can prevent a decrease in the potential of the photoconductor. When such an insulating layer is used as a surface protective layer in a current photoreceptor, as described above, the residual potential is large, and is not practical. This is because the photoreceptor described in JP-A-53-29726 is used far from the current mainstream electrophotographic process. Therefore, in order to improve this point, at least the thickness of the insulating layer must be further reduced (it is not enough). If silicone oil is added only to the insulating layer, a continuous effect is expected. Can not.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art, and to reduce the wear resistance during repeated use without impairing the photoreceptor characteristics and without affecting the image characteristics. It is an object of the present invention to provide a photoreceptor which is excellent in performance and at the same time can reduce the surface energy of the photoreceptor and is prevented from toner filming and background contamination.

[0014]

The present inventor has paid attention to the fact that the surface of the photoreceptor is worn by contact between the photoreceptor and a contact member surrounding the photoreceptor, and has studied diligently to reduce the abrasion amount. As a result, it was found that reducing the frictional force between the photosensitive member and the contact member is one of the keys for achieving the above object. In addition, it has been found that this can be achieved by reducing the surface energy of the contact member or the photoreceptor.

In order to realize the above-mentioned items, the following three methods can be considered. That is, one is to reduce the surface energy of all the contact members, and the other is to externally add a material capable of reducing the frictional force between the photoconductor and the contact members. The other one is to reduce the surface energy of the photoconductor. Of these, the first method is not impossible, but it is necessary to perform some processing on all the contact members, which is not practical in view of cost and the like. The second method is also a relatively simple method, but when it is actually mounted on an electrophotographic process, the size of the machine is increased and the cost is increased. Then, the remaining third method is the most realistic.

As a means for reducing the surface energy of the photoreceptor, several methods can be considered, but addition of a material having a small surface energy is common. However, when a material having such a function is added, the electrical characteristics of the obtained photoreceptor may be significantly impaired, and it is necessary to avoid this. The present inventor paid attention to the above-mentioned prior art, Japanese Patent Application Laid-Open No. 57-5050, and studied why the coating film defects are reduced. As a result, the addition of methylphenyl silicone oil lowers the surface energy of the coating film. I found Focusing on this point, as a result of a study to reduce the surface energy of the photosensitive layer (charge transport layer), it was found that the object of the present invention can be achieved by adding a very large amount of silicone oil. Was completed.

Therefore, according to the present invention, (1) in an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, at least a silicone oil compatible with a material constituting the photosensitive layer is coated with a photosensitive layer; An electrophotographic photosensitive member characterized by being added in an amount exceeding the limit of compatibility with the material constituting the layer. ", (2)" The photosensitive layer of the electrophotographic photosensitive member has a charge generation layer and a charge transport layer. (1) The electrophotographic photoreceptor according to the above (1), comprising a laminated structure, wherein silicone oil is added to the charge transport layer. The electrophotographic photosensitive member according to the above (1) or (2), wherein the size of the droplet is 1 μm or less in diameter. ”,
(4) The above-mentioned (1) or (2), wherein, when the silicone oil is deposited in the layer, the relationship between the size of the particles or droplets and the film thickness satisfies the following expression (1). Electrophotographic photoreceptor.

## EQU2 ## (1) "(1)" wherein the protective layer is provided on the photosensitive layer. Or the electrophotographic photosensitive member according to any one of (4) to (4). ", (6)
“Electrophotographic photoreceptor according to any one of the above (1) to (5), wherein a silicone oil is also used in the protective layer”, (7) “Binder resin used in the photosensitive layer” (8) The electrophotographic photoreceptor according to any one of the above (1) to (4), wherein the polycarbonate comprises at least one of the following (2) The electrophotographic photosensitive member according to (7), which is a polycarbonate having a structure represented by the formula:

[0018]

Embedded image In the formula, when R ₃₀₁ and R ₃₀₂ are each independently, a hydrogen atom, an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. (Including a substituted alkyl group such as trifluoromethyl), an aryl group such as phenyl and naphthyl (including a substituted aryl group having a substituent such as halogen and an alkyl group having 1 to 5 carbon atoms), and R ₃₀₁ And R ₃₀₂ represent a group of carbon elements necessary to form a cyclic hydrocarbon group containing cycloalkanes such as hexyl and polycycloalkanes such as norbornyl. R
₃₀₃ and R ₃₀₄ each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom such as chlorine, bromine or iodine. (9) The above (7), wherein the polycarbonate is a polycarbonate containing at least a structure represented by the following formula (3) in a repeating unit.
2. The electrophotographic photoreceptor of claim 1.

[0019]

Embedded image (10) The electrophotographic photosensitive member according to (7), wherein the polycarbonate is a polycarbonate containing at least a structure represented by the following formula (4) in a repeating unit.

[0020]

Embedded image (11) The electrophotographic photosensitive member according to (7), wherein the polycarbonate is a polycarbonate containing at least a structure represented by the following formula (5) in a repeating unit.

[0021]

Embedded image Is provided.

Thus, without affecting the photoreceptor characteristics,
The reason why a photoreceptor having excellent abrasion resistance during repeated use is formed without impairing the image characteristics is not clear, but can be considered as follows at present. Apart from the single-layer photosensitive layer, the outermost layer of the photoreceptor is generally optically transparent. This is because the image light needs to be transmitted through the outermost layer. Therefore, the material added to reduce the surface energy needs to be compatible with the material forming the outermost layer. Of course, when present as fine particles smaller than the wavelength of the image light, there may be cases where the particles can be optically transparent, but it is quite difficult to cover the entire visible light range. In addition, when manufacturing is considered, it is necessary to consider the dispersion stability of the coating liquid, and the design becomes complicated. Considering such a point, it is preferable that the coating liquid is in a “dissolved” state (dissolved via a solvent). As a result, the silicone oil according to the present invention conforms to such a viewpoint and is preferably used.

In the present invention, the term "compatible" refers to a case where the material constituting the layer to which the silicone oil is added is dissolved in a solid state (after drying) and is optically transparent.
The "state exceeding the limit of compatibility" literally indicates a state where phase separation occurs in a layer to which silicone oil is added (which occurs when a very large amount is added). The term “precipitation” in the present specification does not necessarily mean only a solid state, but also includes such a state. Although the layer constitution of the photoreceptor will be described later, the photosensitive layer of the photoreceptor of the present invention may be a single-layer photosensitive layer or a laminated photosensitive layer of a charge generation layer and a charge transport layer. In any case, the object of the present invention (improvement of abrasion resistance) is achieved if at least silicone oil is added to the photosensitive layer to form a state in which the surface energy is reduced.

On the other hand, for the purpose of the present invention, it is necessary that such effects be continuously obtained over a long period of time. Taking this point into account, in a state in which the material is compatible with the material constituting the photosensitive layer as described above, the amount becomes insufficient from a quantitative viewpoint.
In such a case, the persistence of the effect can be improved by adding an amount exceeding the limit of compatibility. This is one point of the present invention. At this time, the silicone oil naturally precipitates in the layer, but usually the outermost layer [in the case where the photoconductor is constituted by a laminated structure, not only the outermost layer but also the innermost layer (the side closer to the support)] Formed in another layer], resulting in a form in which silicone oil is stocked in the photoreceptor (bleeding out to the surface as necessary).

In this case, the outermost layer (photosensitive layer) is opaque in appearance, and it appears that the image light does not proceed to the inside of the photoreceptor. However, the degree of scattering of the image light is wavelength dependent, and The longer the wavelength, the more advantageous. actually,
In the LD region (red to near infrared), almost 100% of the image light is transmitted, and there is almost no problem in the visible region (blue to red). Although the degree of this scattering is remarkable in ultraviolet light having a short wavelength, the light in this area is not used as image light in a normal electrophotographic process, but rather is cut off because it is harmful to the photoconductor. It is often used without any problem.

The size of the silicone oil particles or droplets deposited in the photosensitive layer (charge transport layer) is one factor that affects image characteristics. As a result of investigations in the present invention, it has been found that if the size is 1 μm or less in diameter, normal images are not affected. If the size is larger than this, it may affect a part of the image.This is because the optical carrier formed inside the photoreceptor cannot cross the silicone oil portion having no carrier transportability. Seem. From a very microscopic point of view, the effect may be as small as 1 μm, but from the viewpoint of the particle size of the toner used in a normal electrophotographic process, the reproducibility of development and transfer, etc. Is presumed to be because it is not observed. In addition, the size of the particles or droplets is related to the thickness of the layer to be added. As a result of the examination, if the size is smaller than 1/20 of the film thickness,
Does not affect the image. It is presumed that this is because, with the above-described size, the progress of the photocarrier in the direction of the surface (photosensitive member surface or support surface) is not hindered with this size.

The layer to which silicone oil is added may be added not only to the outermost layer but also to a layer closer to the support. In particular, when added in an amount exceeding the compatibility, the form accumulated inside may be more advantageous, and it is desirable to select an effective means after confirmation. Also in this case, contrary to the above, there is a case where it may seep out to the outermost layer side, but there is no particular problem, and the breathing out to the surface layer side in repeated use is as described above. It is an effective means to use a protective layer in combination for protecting the surface of the photoreceptor. In this case, it is an effective means to add silicone oil to the photosensitive layer in view of the film thickness.

As the silicone oil used in the present invention, known silicone oils can be used. For example,
Dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen polysiloxane, cyclic dimethyl polysiloxane, alkyl-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, amino-modified silicone oil, mercapto-modified silicone oil Epoxy-modified silicone oil, carboxyl-modified silicone oil, higher fatty acid-modified silicone oil, higher fatty acid-containing silicone oil, and the like. In addition, any material that can reduce the surface energy of the outermost layer can be used. Especially, methylphenyl silicone oil can be used effectively.

Next, the electrophotographic photosensitive member of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration example of a photoconductor used in the present invention, in which a photosensitive layer (15) is formed on a conductive support (11). FIG.
It is sectional drawing which shows another structural example, Comprising: A conductive support body (11)
The upper photosensitive layer (15) is a laminated type of a charge generation layer (17) and a charge transport layer (19). FIG.
FIG. 4 is a cross-sectional view showing still another configuration example, in which a photosensitive layer (1) is shown.
An intermediate layer (23) is provided between 5) and the conductive support (11). Also in this case, the photosensitive layer (15) may have a single-layer structure or a laminated structure including the charge generation layer (17) and the charge transport layer (19). FIG. 4 is a sectional view showing still another configuration example, in which a photosensitive layer (15) and a protective layer (21) are formed on a conductive support (11). In this case, the photosensitive layer (15) may be a single-layer photosensitive layer or a laminated photosensitive layer.

Next, the configuration of the electrophotographic photosensitive member according to the present invention will be described. As the conductive support (11),
Those exhibiting a conductivity of 10 ¹⁰ Ω or less, such as aluminum, nickel, chromium, nichrome, copper, silver, gold,
Metals such as platinum and iron, and oxides such as tin oxide and indium oxide coated on film or cylindrical plastic or paper by evaporation or sputtering, or plates made of aluminum, aluminum alloy, nickel, stainless steel, etc. And D. I. , I. I. , Extrusion, drawing, etc., after forming into a tube, cutting, super finishing,
A tube or the like that has been surface-treated by polishing or the like can be used.

The photosensitive layer (15) in the present invention may be of a single layer type or a laminated type, but here, for convenience of explanation, the laminated type will be described first. First, the charge generation layer (17) will be described. The charge generation layer (17) is a layer containing a charge generation substance as a main component, and may use a binder resin as needed. As the charge generation substance, an inorganic material and an organic material can be used. Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous silicon. As amorphous silicon, a material obtained by terminating a dangling bond with a hydrogen atom or a halogen atom, or a material doped with a boron atom, a phosphorus atom, or the like is preferably used.

On the other hand, as the organic material, a known material can be used. For example, metal phthalocyanine, phthalocyanine pigments such as metal-free phthalocyanine, azulhenium salt pigment, methine squaric acid pigment, azo pigment having a carbazole skeleton, azo pigment having a triphenylamine skeleton, azo pigment having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigment having a fluorenone skeleton, azo pigment having an oxadiazole skeleton, azo pigment having a bisstillene skeleton, azo pigment having a distyryl oxadiazole skeleton, azo pigment having a distyryl carbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinone imine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generating substances can be used alone or as a mixture of two or more kinds.

The binder resin used as needed in the charge generation layer (17) includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral,
Polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole, polyacrylamide and the like are used. These binder resins can be used alone or as a mixture of two or more. Further, a charge transporting material described below may be added as needed.

The method for forming the charge generation layer (17) includes:
A vacuum thin film preparation method and a casting method from a solution dispersion system are mainly mentioned. As the former method, a vacuum evaporation method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-mentioned inorganic material and organic material can be favorably formed.

In order to form a charge generating layer by the casting method described below, the above-mentioned inorganic or organic charge generating substance is used together with a binder resin, if necessary, using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone. It can be formed by dispersing with a ball mill, an attritor, a sand mill, or the like, diluting the dispersion liquid appropriately, and applying. The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like. The thickness of the charge generation layer provided as described above is appropriately about 0.01 to 5 μm, and preferably 0.05 to 2 μm.

Next, the charge transport layer (19) will be described. The charge transport layer (19) dissolves or disperses the charge transport material and the binder resin in an appropriate solvent, and coats and dissolves the same.
It can be formed by drying. If necessary, a plasticizer or a leveling agent may be added.

The charge transporting material that can be used in combination with the charge transporting layer (19) includes a hole transporting material and an electron transporting material. Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone,
4,5,7-tetranitro-9-fluorenone, 2,
4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4
H-indeno [1,2-b] thiophen-4one, 1,
Electron accepting substances such as 3,7-trinitrodibenzothiophene-5,5-dioxide are exemplified. These electron transport materials can be used alone or as a mixture of two or more.

As the hole transporting material, the following electron-donating materials can be used, and are preferably used. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9-
(P-diethylaminostyrylanthracene), 1,1
-Bis- (4-dibenzylaminophenyl) propane,
Styryl anthracene, styryl pyrazoline, phenylhydrazone, α-phenylstilbene derivative, thiazole derivative, triazole derivative, phenazine derivative,
Examples include acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. These hole transport substances can be used alone or as a mixture of two or more.

As the binder resin used for the charge transport layer (19), polycarbonate (bisphenol A)
Type, bisphenol Z type), polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenolic resin, epoxy resin, polyurethane, polyvinylidene chloride, alkyd resin, silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl Formal, polyacrylate, polyacrylamide, phenoxy resin and the like are used. Among them, the above (2) to
The polycarbonate having the structure of the formula (4) is effectively used. These binders can be used alone or as a mixture of two or more.

Further, a polymer charge transport material having both functions of a binder resin and a charge transport material can be used as the binder resin. Examples of the polymer charge transport material used in this case include the following.

(A) Polymer having carbazole ring in main chain and / or side chain For example, polymer of poly-N-vinyl carbazole, polymer of N-acrylamidomethyl carbazole disclosed in JP-A-50-82056 Halogenated poly-N-vinylcarbazole described in JP-A-54-9632, poly-N-acrylamidomethylcarbazole and poly-N-acrylamidomethylcarbamoylalkylcarbazole described in JP-A-54-11737, 4
-183719, a specific dihydroxy compound having a carbazole structure, that is, bis [N-hydroxyaryl (or -hydroxyhetero) -N-aryl]
Examples include carbazole-based polycarbonates and compounds obtained by reacting an amino-substituted carbazole or a bisphenol compound with a carbonate-forming compound.

(B) Polymer having a hydrazone structure in the main chain and / or side chain For example, the dehydrochlorination condensation of chloromethylated polystyrene with 4-hydroxybenzylidenebenzylphenylhydrazone described in JP-A-57-78402. Polystyrene having a hydrazone structure produced
For example, polystyrene compounds having a 4-hydrazone side chain structure generated by dehydration condensation of poly (4-formylstyrene) and 1,1-diarylhydrazine described in Japanese Patent No. 50555 are exemplified.

(C) Polysilylene polymer For example, poly (methylphenylsilylene), poly (n-propylmethylsilylene) -1-methylphenylsilylene or poly (n-propylmethylsilylene) described in JP-A-63-285552 ), JP-A-5-1949
No. 7-(Si (R ₁ ) (R ₂ ))-, or

[0044]

Embedded image A polysilane compound having a repeating unit of (R ₁ , R ₂ ,
R ₃ and R ₄ are exemplified by compounds of H, halogen, ether group, substituted alkyl group, etc.).

(D) Polymer having a tertiary amine structure in the main chain and / or side chain, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-13061, And the general formula described in JP-A-1-19049

[0046]

Embedded image (Where Ar and Ar ′ are aryl, and Z is carbazole-
R and R 'each independently represent --CH ₂ -,-(CH ₂₎ , such as a 4,7-diyl group, a fluorenine group, a phenylene group, a pyrenediyl group, and a 4,4′-biphenylene group. )
_{2 -, - (CH 2)} 3 - and _{- (CH 2) 4 -,} R " is -CO-
Or —CO—O—C ₆ H ₄ —Y—C ₆ H ₄ —O—CO— (Y
It is _{-O -, - CH 2 -,} - S -, - C (Me) 2 - , etc.), m
Represents 0 or 1, and n represents 5-5000. ), Japanese Patent Laid-Open No. 1
R- [OAO-CH ₂ -CH (OR) -CH ₂ -O-B described in
_{-O-CH 2 -CH (OR)} -CH 2] m- (R is H, -Me, -Et, m is 4-1
000, A is -Ar-N (Ar ')-[Z]-[N (Ar')-
Ar] n- (Z is a carbazole-4,7-diyl group, a fluorenylene group, a phenylene group, a pyrenediyl group,
A divalent unsaturated cyclic group such as a 4′-biphenylene group, Ar,
Ar ′ is an aryl group), B has the same meaning as A, or —Ar
-V-Ar (V is _{-CH 2 -, - O -,} - S -, - C (M
e) _2-, etc.). ) Having an arylamine-containing polyhydroxyether resin described in JP-A-5-66598.

[0047]

Embedded image (N ₁ is 1 to 10, n ₂ is 0 to 4, n ₃ is 0 to 5, m is 0
(Meth) acrylic acid ester (co) polymers having the structures of 1) to 1) described in JP-A-5-40350;
Structural unit

[0048]

Embedded image (R ₁ and R ₂ are alkyl, aryl, aralkyl, A
r ₁ , Ar ₂ and Ar ₃ are divalent aromatic residues, l is an integer of 0 or more, m is an integer of 1 or more, n is an integer of 2 or more, and p is 3 to
And the like having an integer of 6).

(E) Other polymers: For example, a formaldehyde condensation polymer of nitropyrene, a polymer of a 6-vinylindolo [2,3-b] quinoxaline derivative described in JP-A-51-73888, and JP-A-150749 discloses 1,1-bis (4
-Dibenzylaminophenyl) propane formaldehyde condensation resin compound and the like.

The polymer charge transporting material used in the present invention includes not only the above-mentioned polymers but also copolymers of known monomers,
Block polymer, graft polymer, star polymer,
Further, for example, as disclosed in JP-A-3-109406,

[0051]

Embedded image It is also possible to use a crosslinked polymer having an electron donating group.

The thickness of the charge transport layer (19) is 5 to 100.
About μm is appropriate. In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer (19).

As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is preferably about 0 to 30% by weight based on the binder resin. It is.

Next, the case where the photosensitive layer (15) has a single-layer structure will be described. The inorganic photosensitive layer is made of the amorphous
The selenium, selenium alloy, amorphous silicon photosensitive layer, etc. are also provided by the above-mentioned vacuum deposition method, glow discharge decomposition method, ion plating method, sputtering method, reactive sputtering method, CVD method or other vacuum thin film forming method. Can be. Further, a photoconductor in which two or more of these inorganic material layers are laminated also belongs to the category of the present invention.

When a single-layer photosensitive layer is provided by a casting method, a function-separated type layer comprising a charge generating substance and a charge transporting substance is often used. That is, the above-mentioned materials can be used as the charge generating substance and the charge transporting substance. The single-layer photosensitive layer can be formed by dissolving or dispersing the charge generating substance, the charge transporting substance, and the binder resin in an appropriate solvent, and coating and drying the resulting solution. If necessary, a plasticizer or a leveling agent may be added. As the binder resin, in addition to using the binder resin described above for the charge transport layer (19) as it is, in addition to the charge generation layer (1)
The binder resins mentioned in 7) may be mixed and used.

In the single-layer photosensitive layer, the charge generating substance, the charge transporting substance and the binder resin are dispersed by a ball mill, an attritor, a sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane or butanone. It can be formed by diluting and applying. The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like.
A photoreceptor in which a charge transporting substance is added to a eutectic complex formed from a pyrylium-based dye or a bisphenol A-based polycarbonate can be formed by a similar coating method from a suitable solvent.
The thickness of the single-layer photoreceptor is suitably about 5 to 100 μm.

The electrophotographic photosensitive member used in the present invention includes:
An intermediate layer (2) is provided between the conductive support (11) and the photosensitive layer (15) [in the case of a laminate type, the charge generation layer (17)].
3) can be provided. The intermediate layer (23) is provided for the purpose of improving adhesiveness, preventing moire, improving coating properties of the upper layer, reducing residual potential, and the like.
The intermediate layer (23) generally contains a resin as a main component. However, considering that the photosensitive layer is coated thereon with a solvent, these resins are resins having high resistance to dissolution in general organic solvents. It is desirable. Such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymerized nylon, alcohol-soluble resins such as methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, epoxy resin, and the like. Curable resins that form a three-dimensional network structure are exemplified. Further, a fine powder of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, or a metal sulfide or a metal nitride may be added. These intermediate layers can be formed using an appropriate solvent and a coating method as in the case of the above-described photosensitive layer.

Further, as the intermediate layer of the present invention, a metal oxide layer formed by, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent or the like is also useful. In addition, the intermediate layer of the present invention is provided with Al ₂ O ₃ by anodic oxidation, an organic substance such as polyparaxylene (parylene), SiO, SnO, or the like.
₂ , an inorganic material such as TiO ₂ , ITO, CeO ₂ provided by a vacuum thin film manufacturing method can also be used favorably. The thickness of the intermediate layer is suitably from 0 to 5 μm.

The protective layer (21) is a layer provided for the purpose of protecting the surface of the photoreceptor. The protective layer (21) is formed by adding a polymer charge transport material to a suitable solvent, for example, tetrahydrofuran,
It can be formed by dissolving or dispersing in dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride, cyclohexanone, etc., and applying and drying. For the protective layer, the above-described polymer charge transport material can be used, and in addition, an electrically inactive binder resin can be used. Materials used for this include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, Polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate,
Polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone,
Polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, epoxy resin, and the like, and among them, a cured product of a curable material and a curing agent are exemplified. Among them, polycarbonates having the structures of the above formulas (2) to (4) in the repeating unit are effectively used.

In addition, a filler material can be added to the protective layer for the purpose of improving abrasion resistance. Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, and the like.As the inorganic filler material,
Metal powder such as copper, tin, aluminum, indium,
Metal oxides such as tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, antimony-doped tin oxide, and tin-doped indium oxide;
An inorganic material such as potassium titanate can be used. These filler materials are used alone or in combination of two or more. These filler materials can be dispersed in the coating liquid for the protective layer by using an appropriate disperser. The average particle size of the filler is 0.5 μm or less, preferably 0.2 μm
The following is preferred from the viewpoint of the transmittance of the protective layer.

In the present invention, a plasticizer or a leveling agent may be added to the protective layer (21). As the plasticizer and the leveling agent, the materials described for the charge transport layer can be used as they are. As a method for forming the protective layer, a normal coating method is employed. Incidentally, the film thickness is suitably about 0.5 to 10 μm. The silicone oil added to the electrophotographic photoreceptor of the present invention can also be added to the protective layer. Thereby, the surface energy of the outermost layer is reduced and the wear resistance is improved. It is also possible to add the protective layer and a layer closer to the support than the above as described above,
It is valid.

The silicone oil added to the electrophotographic photoreceptor of the present invention is added to at least the above-mentioned photosensitive layer (in the case of a laminated type, a charge transport layer or both a charge transport layer and a charge generation layer). Thereby, the surface energy of the outermost layer is reduced and the wear resistance is improved. Further, as described above, it is also possible to add simultaneously to the outermost layer or a layer closer to the support than that, which is effective. Further, when a protective layer is used in combination, silicone oil may be added to the protective layer. The amount of the silicone oil to be added depends on the combination of the materials used, but is generally 0.5% by weight or more based on the total solid content of the material constituting the layer to which the silicone oil is added.

In the present invention, an antioxidant can be added for the purpose of improving the environmental resistance, especially for the purpose of preventing a decrease in sensitivity and an increase in residual potential. The antioxidant may be added to any layer containing an organic substance, but good results can be obtained by adding it to a layer containing a charge transporting substance. The antioxidants that can be used in the present invention include the following.

Monophenolic compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5- Di-t-
(Butyl-4-hydroxyphenyl) propionate and the like.

Bisphenol compounds 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-
Ethyl-6-t-butylphenol), 4,4′-thiobis- (3-methyl-6-t-butylphenol),
4,4'-butylidenebis- (3-methyl-6-t-butylphenol) and the like.

High-molecular phenolic compound 1,1,3-tris- (2-methyl-4-hydroxy-
5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-
4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy -3'-t-butylphenyl) butyric acid] glycol esters, tocophenols and the like.

Paraphenylenediamines N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-
Phenylenediamine, N, N'-di-isopropyl-p
-Phenylenediamine, N, N'-dimethyl-N, N '
-Di-t-butyl-p-phenylenediamine and the like.

Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t
-Octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like.

Organic sulfur compounds: dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate and the like.

Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

These compounds are known as antioxidants for rubbers, plastics, oils and the like, and can be easily obtained as commercial products. The addition amount of the antioxidant in the present invention is 0.1 to 100 parts by weight based on 100 parts by weight of the charge transporting substance.
Parts by weight, preferably 2 to 30 parts by weight.

[0072]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples. In the examples, all parts used are parts by weight.

Example 1 A coating liquid for an intermediate layer, a coating liquid for a charge generation layer, and a coating liquid for a charge transport layer having the following compositions were sequentially coated and dried on an aluminum cylindrical support having a diameter of 60 mm. As a result, an intermediate layer having a thickness of about 3.5 μm, a charge generation layer having a thickness of about 0.3 μm, and a charge transport layer having a thickness of about 20 μm were formed.

[Coating Liquid for Intermediate Layer] 375 parts of alkyd resin solution (Dainippon Ink and Chemical: Beccolite M-6401-50) Melamine resin solution 210 parts (Dainippon Ink and Chemical: Super Beckamine G-821) 60) Titanium dioxide (Ishihara Sangyo: Taipaque CR-EL) 1250 parts 2-butanone 7800 parts [Coating liquid for charge generation layer] 5 parts of charge generation material having the following structure

[0075]

Embedded image Polyvinyl butyral (manufactured by UCC: XYHL) 2 parts Cyclohexanone 200 parts Tetrahydrofuran 200 parts [Coating liquid for charge transport layer] Bisphenol Z-type polycarbonate 10 parts Charge transport material having the following structure 7 parts

[0076]

Embedded image Methylphenyl silicone oil 0.01 parts (Shin-Etsu Silicone: KF56) Methylene chloride 90 parts

Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.05 part. Example 3 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.1 part. Example 4 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.5 part. Example 5 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 1 part. Example 6 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the amount of the silicone oil in the charge transport layer coating liquid in Example 1 was changed to 2 parts.

Comparative Example 1 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.001 part. Comparative Example 2 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was 0.002 parts. Comparative Example 3 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.005 part. Comparative Example 4 An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that no silicone oil was added to the coating solution for the charge transport layer in Example 1.

Further, the coating liquid for the charge transport layer used in Examples 1 to 6 and Comparative Examples 1 to 4 was coated on a glass substrate by about 2 μm.
m of the charge transport layer was formed to prepare a sample for measuring surface energy. Further, Examples 1 to 6 and Comparative Examples 1 to
Using the charge transport layer coating liquid used in No. 4, an aluminum vapor-deposited polyethylene terephthalate film is
Was formed as a sample for cross-sectional observation.
The photoconductors of Examples 1 to 6 and Comparative Examples 1 to 4 manufactured as described above were mounted on a copying machine (Ricoh: Spirio 3500) and mounted on a copier. A running test was performed. At this time, the image evaluation at the initial stage and after the running, and the abrasion amount of the photoconductor were measured. Also,
The measurement of the surface energy was determined by measuring the contact angle. The contact angle is 31-50 μN / c for the wetting test drug.
m diethylene glycol monoethyl ether,
It was measured by Kyowa Chemical (angle meter). Further, the cross section of the charge transporting layer formed on the polyethylene terephthalate film on which aluminum was vapor-deposited was observed with a scanning electron microscope, and the particle size of the precipitated silicone oil was determined.
The results are shown in Table 1.

[0080]

[Table 1]

Example 7 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the coating solution for the charge transport layer in Example 1 was changed to a coating solution for the charge transport layer having the following composition. [Coating liquid for charge transport layer] Bisphenol A type polycarbonate 10 parts Charge transport material having the following structure 7 parts

[0082]

Embedded image Methylphenyl silicone oil 0.01 part (Shin-Etsu Silicone: KF50) 90 parts methylene chloride

Example 8 An electrophotographic photosensitive member was prepared in the same manner as in Example 7, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.3 part. Comparative Example 5 An electrophotographic photosensitive member was produced in the same manner as in Example 7, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.001 part. Comparative Example 6 An electrophotographic photosensitive member was produced in the same manner as in Example 7, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.005 part. Comparative Example 7 An electrophotographic photosensitive member was produced in the same manner as in Example 7, except that the silicone oil was not added to the coating solution for the charge transport layer in Example 7.

Using the coating liquid for the charge transport layer used in Examples 7 to 8 and Comparative Examples 5 to 7, about 2 μm
m of the charge transport layer was formed to prepare a sample for measuring surface energy. Furthermore, Examples 7-8 and Comparative Examples 5
About 20 μm on a polyethylene terephthalate film on which aluminum was vapor-deposited using the charge transport layer coating solution used in Example 7.
Was formed as a sample for cross-sectional observation.
The photoconductors of Examples 7 to 8 and Comparative Examples 5 to 7 manufactured as described above were mounted on a copying machine (Ricoh: Spirio 3500) after mounting, and were equivalent to 50,000 sheets without paper passing. A running test was performed. At this time, the image evaluation at the initial stage and after the running, and the abrasion amount of the photoconductor were measured. Also,
The measurement of the surface energy was determined by measuring the contact angle. The contact angle is 31-50 μN / c for the wetting test drug.
m diethylene glycol monoethyl ether,
It was measured by Kyowa Chemical (angle meter). Further, the cross section of the charge transporting layer formed on the polyethylene terephthalate film on which aluminum was vapor-deposited was observed with a scanning electron microscope, and the particle size of the precipitated silicone oil was determined.
The results are shown in Table 2.

[0085]

[Table 2]

Example 9 Example 1 was repeated except that the coating solution for the charge transport layer in Example 1 was changed to a coating solution for the charge transport layer having the following composition.
An electrophotographic photoreceptor was produced in the same manner as described above. [Coating liquid for charge transport layer] Bisphenol C-type polycarbonate 10 parts Charge transport material having the following structure 8 parts

[0087]

Embedded image Methylphenyl silicone oil 0.02 parts (Shin-Etsu Silicone: KF54) 90 parts methylene chloride

Example 10 An electrophotographic photosensitive member was prepared in the same manner as in Example 7, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.4 part. Comparative Example 8 An electrophotographic photoreceptor was produced in the same manner as in Example 9, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.002 part. Comparative Example 9 An electrophotographic photosensitive member was produced in the same manner as in Example 9, except that the addition amount of the silicone oil in the coating solution for the charge transport layer was changed to 0.004 part. Comparative Example 10 An electrophotographic photosensitive member was produced in the same manner as in Example 9, except that the silicone oil was not added to the coating solution for the charge transport layer in Example 9.

Examples 9 to 10 and Comparative Examples 8 to 10
A charge transport layer having a thickness of about 2 μm was formed on a glass substrate using the charge transport layer coating liquid used in Example 1 to prepare a sample for surface energy measurement. Further, using the coating liquid for a charge transport layer used in Examples 9 to 10 and Comparative Examples 8 to 10, a charge transport layer of about 20 μm was formed on a polyethylene terephthalate film on which aluminum was vapor-deposited. And The photoconductors of Examples 9 to 10 and Comparative Examples 8 to 10 manufactured as described above were mounted on a copying machine (Ricoh: Spirio 3500) after mounting, and the photoconductors were placed in a state where no paper was passed.
A running test equivalent to 10,000 sheets was performed. At this time, the image evaluation at the initial stage and after the running, and the abrasion amount of the photoconductor were measured. The surface energy was measured by measuring the contact angle. The contact angle ranges from 31 to 31 for the wetting test drug.
The measurement was performed by Kyowa Chemical (Angle Meter) using 50 μN / cm of diethylene glycol monoethyl ether. Further, the cross section of the charge transporting layer formed on the polyethylene terephthalate film on which aluminum was vapor-deposited was observed with a scanning electron microscope, and the particle size of the precipitated silicone oil was determined. The results are shown in Table 3.

[0090]

[Table 3]

Example 11 A coating liquid for a protective layer having the following composition was laminated on the photoreceptor of Example 1 to prepare an electrophotographic photoreceptor of the present invention. [Coating liquid for protective layer] Bisphenol Z-type polycarbonate 10 parts Tin oxide 5 parts Methylene chloride 90 parts

Example 12 A coating liquid for a protective layer having the following composition was laminated on the photoreceptor of Example 1 to prepare an electrophotographic photoreceptor of the present invention. [Coating liquid for protective layer] Bisphenol A type polycarbonate 10 parts Tin oxide 5 parts Methylphenyl silicone oil 0.1 part (Shin-Etsu Silicone: KF50) 90 parts methylene chloride

Comparative Example 11 A protective layer having a protective layer thickness of 2 μm was laminated on the photoreceptor of Comparative Example 1 by using a coating liquid for a protective layer having the following composition to prepare an electrophotographic photoreceptor. [Coating solution for protective layer] Bisphenol Z-type polycarbonate 10 parts Tin oxide 5 parts Methylene chloride 90 parts Comparative Example 12 On the photoreceptor of Comparative Example 4, the protective layer used in Example 12 was provided.
An electrophotographic photosensitive member was prepared by laminating μm.

Examples 11 and 12 produced as described above
The photoconductors of Comparative Examples 11 and 12 were mounted on a copier (Ricoh: Spirio 3500), and were subjected to a running test for 50,000 sheets without paper passing. At this time, the image evaluation at the initial stage and after the running, and the abrasion amount of the photoconductor were measured. The results are shown in Table 4.

[0095]

[Table 4]

[0096]

As described above in detail and specifically, according to the present invention, the wear of the outermost layer of the photoreceptor in repeated use can be improved at low cost without affecting the electrostatic characteristics. . As a result, a long-term stable image can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an electrophotographic photosensitive member used in an electrophotographic image forming apparatus of the present invention.

FIG. 2 is a cross-sectional view illustrating another configuration of the electrophotographic photosensitive member used in the electrophotographic image forming apparatus of the present invention.

FIG. 3 is a cross-sectional view showing still another configuration of the electrophotographic photosensitive member used in the electrophotographic image forming apparatus of the present invention.

FIG. 4 is a cross-sectional view showing still another configuration of the electrophotographic photosensitive member used in the electrophotographic image forming apparatus of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 conductive support 15 photosensitive layer 17 charge generation layer 19 charge transport layer 21 protective layer 23 intermediate layer

Claims (11)

[Claims] 1. An electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, wherein at least the photosensitive layer is made of a silicone oil compatible with a material constituting the photosensitive layer. An electrophotographic photoreceptor characterized by being added in an amount exceeding a limit. 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer of the electrophotographic photoreceptor has a laminated structure of a charge generation layer and a charge transport layer, and silicone oil is added to the charge transport layer. 3. When the silicone oil precipitates in the layer,
3. The electrophotographic photoreceptor according to claim 1, wherein the size of the particles or droplets is 1 [mu] m or less. 4. When the silicone oil precipitates in the layer,
3. The electrophotographic photosensitive member according to claim 1, wherein the relationship between the size of the particles or droplets and the film thickness satisfies the following expression (1). ## EQU1 ## Size of particle or droplet / thickness of layer to be added <1/20 (1) 5. The electrophotographic photoreceptor according to claim 1, wherein a protective layer is provided on the photosensitive layer. 6. The electrophotographic photoreceptor according to claim 1, wherein a silicone oil is also used in the protective layer. 7. The electrophotographic photosensitive member according to claim 1, wherein the binder resin used in the photosensitive layer contains at least polycarbonate. 8. The electrophotographic photoreceptor according to claim 7, wherein the polycarbonate is a polycarbonate having a structure represented by the following formula (2) in a repeating unit. Embedded image In the formula, when R ₃₀₁ and R ₃₀₂ are each independently, a hydrogen atom, an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. (Including a substituted alkyl group such as trifluoromethyl), an aryl group such as phenyl and naphthyl (including a substituted aryl group having a substituent such as halogen and an alkyl group having 1 to 5 carbon atoms), and R ₃₀₁ And R ₃₀₂ represent a group of carbon elements necessary to form a cyclic hydrocarbon group containing cycloalkanes such as hexyl and polycycloalkanes such as norbornyl. R
₃₀₃ and R ₃₀₄ each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom such as chlorine, bromine or iodine. 9. The electrophotographic photoreceptor according to claim 7, wherein said polycarbonate is a polycarbonate containing at least a structure represented by the following formula (3) in a repeating unit. Embedded image 10. The electrophotographic photoreceptor according to claim 7, wherein said polycarbonate is a polycarbonate containing at least a structure represented by the following formula (4) in a repeating unit. Embedded image 11. The electrophotographic photoreceptor according to claim 7, wherein said polycarbonate is a polycarbonate containing at least a structure represented by the following formula (5) in a repeating unit. Embedded image