JPH11218945A - Electrophotographic photoreceptor and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rise of residual potential in the repeated uses and to enhance transfer efficiency and to improve cleanability by forming a resin layer containing a charge transfer material having fluoroalkyl groups and a fluororesin for the outermost layer of the photoreceptor. SOLUTION: A charge generating layer 17 composed essentially of a charge generating material and a charge transfer layer 19 composed essentially of a charge generating material are laminated on a conductive substrate 11, and the outermost layer is prepared by using a coating fluid obtained, by dispersing the specified charge transfer material having the fluoroalkyl groups and the fluororesin particles of a polymer comprising >=2 kinds of polytetrafluoroethylene and polyvinylidene fluoride and the like into a binder resin solved in a solvent. The charge generating material is embodied by inorganic and organic materials typified by monoazo, disazo, and trisazo pigments and perylene type pigments and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor and an image forming apparatus using the same, and more particularly, to a highly durable electrophotographic photoreceptor which is excellent in toner transfer efficiency, cleanability and environmental stability. The present invention relates to an electrophotographic photosensitive member and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, amorphous silicon, zinc oxide and the like have been mainly used as photoconductive materials for electrophotographic photosensitive members in terms of sensitivity and durability. Materials are harmful,
It has the disadvantage of high cost due to poor productivity. For this reason, organic photoreceptors that are non-polluting, can be mass-produced by coating, and can be easily reduced in cost have been actively developed in recent years.

[0003] Although these organic photoreceptors have advantages such as no pollution and low cost, they still have problems in sensitivity, environmental stability, and durability, and in particular, environmental stability and durability. The development of an electrophotographic photoreceptor having excellent performance is eagerly desired. Furthermore, recent demands for higher image quality have been directed toward reducing the particle size of toner, and an electrophotographic photoreceptor having a high transfer efficiency and a high cleaning property corresponding to this trend has been demanded. Further, in recent years, full-color electrophotographic apparatuses have become widespread, and full-color electrophotographic apparatuses are required to have higher image quality than monochrome machines. In particular, in a full-color electrophotographic apparatus using an intermediate transfer member, a higher transfer performance is required for the photosensitive member in order to transfer from the photosensitive member to paper instead of paper. If the transfer performance of the photoreceptor is poor, a part of the line image will drop out when the image is transferred to the intermediate transfer member, and a so-called insect-eating image will be generated. In order to achieve these, it is particularly desired to reduce the coefficient of friction of the photoreceptor surface and to maintain its long-term stability.

As a method for solving these problems, Japanese Patent Laid-Open Publication No.
-64243, JP-A-60-256146, JP-A-61-95358, JP-A-61-1
JP-A-32954 and JP-A-61-219047 propose that the charge transport layer provided on the surface of the photoreceptor contains a silicone resin or a silicone-containing polymer. However, the method of adding a silicone resin or a silicone-containing polymer has poor abrasion resistance,
Further, there is a disadvantage that the residual potential increases.

Japanese Patent Application Laid-Open No. 57-35863 proposes that a charge transporting layer contains a lubricant such as fine fluorine particles. However, the charge transporting layer has poor dispersibility in a resin, and is required to improve the dispersibility. The use of an auxiliary has the disadvantage that the residual potential increases. Also, JP-A-63-3
No. 0850, JP-A-63-58352, JP-A-63-61255, JP-A-63-61256, JP-A-8-305052, etc. disclose the use of fluorine fine particles and a specific charge transport material. Combinations have been proposed. However, it has not been able to stably maintain the friction coefficient and the residual potential in long-term use. As described above, in reality, various durability problems still remain, and sufficient characteristics have not been obtained even for high transfer efficiency and cleanability requirements.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems by preventing the residual potential from increasing during repeated use, further improving the transfer efficiency, and improving the cleaning property. A highly durable electrophotographic photosensitive member.

[0007]

As a result of repeated studies, the present inventors have completed the present invention. That is, the above object is achieved by (1) an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, wherein the outermost layer of the electrophotographic photosensitive member has a fluoroalkyl group and a charge transport material and fluororesin fine particles. And (2) an image forming apparatus using the same, and (3) the following charge transport material having a fluoroalkyl group: The electrophotographic photoreceptor according to the above (1), which is a substance represented by the formula (1);

[0008]

Embedded image (Wherein, R _{1 to} R ₄ represent a substituted or unsubstituted aryl group,
Rf is -C _n F _2n-1 and (n is integer from 6-12), R represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. )) And (4) an image forming apparatus using the same, and (5) the charge transport material having a fluoroalkyl group is a substance represented by the following general formula (2). The electrophotographic photosensitive member according to the item 1);

[0009]

Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.) And (6) “Image forming apparatus using the same”, (7) “Charge having fluoroalkyl group” The electrophotographic photoreceptor according to the above (1), wherein the transport material is a substance represented by the following general formula (3);

[0010]

Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.) And (8) “Image forming apparatus using the same”, (9) “Static friction coefficient of photoreceptor surface” The electrophotographic photoreceptor according to any one of the above items (1), (3), (5) and (7), and (10) "an image forming apparatus using the same." (11) "A plurality of visible color developed images sequentially formed on the image carrier by the toner are sequentially superimposed on the intermediate transfer body running endlessly and primary-transferred, and the primary transfer is performed on the intermediate transfer body. An image forming apparatus of an intermediate transfer system for collectively and secondarily transferring a primary transfer image to a transfer material, wherein the image carrier has the above-mentioned items (1), (3),
An image forming apparatus characterized in that the photoconductor is the photosensitive member according to any one of the above mode (5) and the mode (7).

[0011]

Next, the contents of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a single-layer photoreceptor of the present invention. A single-layer photoreceptor (15) containing a charge generation material and a charge transport material as main components on a conductive support (11).
Is provided. FIG. 2 is a cross-sectional view showing a configuration example of the laminated photoreceptor of the present invention, wherein a charge generation layer (17) mainly containing a charge generation material and a charge transport layer (19) mainly containing a charge transport material. Are laminated. FIG. 3 is a cross-sectional view showing another configuration example of the laminated photoreceptor of the present invention, which has a configuration in which a protective layer (21) is further laminated on a charge transport layer (20).

In the present invention, the outermost layer is a layer containing the charge transporting material having the fluoroalkyl group and fine fluorine particles, and means a layer provided on the surface of the electrophotographic photosensitive member. Therefore, in the case of a single layer photoreceptor, the photosensitive layer is the outermost layer, and in the case of a laminated photoreceptor, the layer provided on the surface of either the charge transport layer or the protective layer is referred to as the outermost layer. Become.

When the protective layer (21) is not provided, the charge transport layer (19) contains a charge transport material having a fluoroalkyl group and fine fluorine particles. When the protective layer (21) is provided, this layer contains a charge transport material having a fluoroalkyl group and fine fluorine particles. in this case,
The charge transporting material used for the charge transporting layer (20) is not particularly limited, but is selected so as to satisfy characteristic values such as charge mobility and residual potential.

In the present invention, a charge transporting material represented by the general formulas (1) to (3) and polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, Or tetrafluoroethylene, vinylidene fluoride,
A coating liquid in which fine particles of fluorine, such as a polymer made of two or more kinds selected from hexafluoropropylene, are dissolved in a solvent and dispersed in a binder resin liquid is used. The dispersion may be performed by a paint shaker, a sand mill, a bead mill, a ball mill, an ultrasonic disperser, or the like, if necessary. The coating liquid is formed into a film by a method such as dipping and dried at a predetermined temperature to obtain an electrophotographic photosensitive member of the present invention.

As the conductive support (11), those having a conductivity of not more than 10 ¹⁰ Ωcm, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold and platinum, tin oxide, Metal oxides such as indium oxide, by vapor deposition or sputtering, coated on film or cylindrical plastic, paper, or aluminum, aluminum alloy, nickel, stainless steel, etc. A tube or the like that has been surface-treated by superfinishing, polishing, or the like can be used.

Next, the photosensitive layers (15), (17) + (1)
9), (17) + (20) will be described. The photosensitive layer may be a single layer or a laminated layer. For convenience of explanation, the case where the photosensitive layer is composed of the charge generation layer (17) and the charge transport layer (19) (the configuration in FIG. 2) will be described first. The charge generation layer (17)
This is a layer containing a charge generation material as a main component. Inorganic and organic materials are used for the charge generation material, and as typical examples, monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squaric acid dyes, Phthalocyanine pigments, naphthalocyanine pigments, azulenium salt dyes, selenium, selenium-tellurium, selenium-arsenic alloys, amorphous silicon and the like are used.

The charge generating material (17) is used alone or in combination of two or more. The charge generation layer is obtained by dispersing the charge generation material with an appropriate solvent such as tetrahydrofuran, cyclohexanone, dioxane, 2-butanone, or dichloroethane using a ball mill, an attritor, a sand mill, or the like, and applying a dispersion. Can be formed. The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like. Examples of suitable binder resins include polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, and polyacrylamide. The amount of the binder resin is suitably from 0 to 2 parts by weight based on 1 part by weight of the charge generating material. When the charge generation layer does not correspond to the outermost layer, it can be provided by a known vacuum thin film manufacturing method. The thickness of the charge generation layer (17) is 0.0
About 1 to 5 μm is appropriate, and preferably 0.1 to 2 μm.
m.

The charge transporting layer (19) can be formed by dissolving or dispersing a charge transporting material and a binder resin in a suitable solvent, coating and drying. Further, a plasticizer or the like can be added as necessary. Also, silicone oil or the like may be added as a film smoothing agent. Examples of the charge transport material include a material having a fluoroalkyl group represented by the following general formula. These charge transport materials may be used alone or in combination.

[0019]

Embedded image (Wherein, R _{1 to} R ₄ represent a substituted or unsubstituted aryl group,
Rf is -C _n F _2n-1 and (n is integer from 6-12), R represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. )

[0020]

Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.)

[0021]

Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.)

Hereinafter, specific examples of the general formula (1) are shown in Table 1.
Table 2 shows specific examples of the general formula (2), and Table 3 shows specific examples of the compound of the general formula (3).

[0023]

[Table 1]

[0024]

[Table 2-1]

[0025]

[Table 2-2]

[0026]

[Table 3-1]

[0027]

[Table 3-2]

The charge transporting layer (19) further contains the above-mentioned fluororesin fine particles. By containing the fluorine fine particles, the friction coefficient and surface energy of the photoreceptor surface are reduced, the abrasion resistance is improved, the transfer efficiency of the toner is improved, and a high quality image can be stably provided. Become like However, merely containing fluorine fine particles has a certain effect, but the characteristics cannot be sufficiently maintained when used for a long period of time such as tens of thousands. In the present invention, by using the above-described charge transporting material having a fluoroalkyl group and the fine fluorine particles in combination, the initial characteristics can be maintained for a long period of time. The content of the fluororesin fine particles is about 1 to 30% of the total solids. Preferably, 5 to 10
%. If it is less than 1%, stable surface characteristics cannot be obtained.
Above 30%, disadvantages such as a remarkable decrease in sensitivity and a remarkable increase in residual potential occur. If it is 5% or less, sufficiently stable surface characteristics cannot be obtained, and if it is 10% or more, problems such as a decrease in sensitivity and an increase in residual potential occur.

The charge transport layer together with the charge transport material (19)
Polystyrene, as the binder resin used for
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, Thermoplastic or thermosetting resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin can be used. Among them, polycarbonate is preferable because it has excellent environmental properties, abrasion resistance and mechanical properties when used as an electrophotographic photosensitive member.

Examples of the solvent include tetrahydrofuran, dioxane, toluene, 2-butanone, monochlorobenzene, dichloroethane, methylene chloride and the like.
The thickness of the charge transport layer (19) is suitably from 5 to 100 μm. In the present invention, a plasticizer may be added to the charge transport layer (19). As the plasticizer, those used as general plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is suitably about 0 to 30% by weight based on the binder resin.

Next, the case where the protective layer (21) is laminated on the charge transporting layer (20) (the configuration of FIG. 3) will be described. The protective layer (21) has the same configuration as the above-described charge transport layer (20) in that the binder resin contains a charge transport material having a fluoroalkyl group and fine fluorine particles in the binder resin. As the charge transporting material used for the charge transporting layer (20) below this protective layer, the charge transporting material used for the protective layer (21) is also used. Can be used.

For example, oxazole derivatives, imidazole derivatives, triphenylamine derivatives, and compounds represented by the following general formulas (4) to (22) can be used.

[0033]

Embedded image (Wherein, R ₁ represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, R ₂ represents a methyl group, an ethyl group, a benzyl group or a phenyl group, R ₃ represents a hydrogen atom, Represents a bromine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group, or a nitro group.)

The compound represented by the general formula (4) includes, for example, 9-ethylcarbazole-3-aldehyde-1-aldehyde.
Methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1-benzyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-
Examples include 1,1-diphenylhydrazone.

[0035]

Embedded image (In the formula, Ar represents a naphthalene ring, an anthracene ring, a styryl ring, or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents an alkyl group.)

The compound represented by the general formula (5) includes, for example, 4-diethylaminostyryl-β-aldehyde-
There are 1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone and the like.

[0037]

Embedded image (Wherein, R ₁ is an alkyl group, a benzyl group, a phenyl group,
Or a naphthyl group, wherein R ₂ is a hydrogen atom,
Represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group, or a diarylamino group; n represents an integer of 1 to 4;
Is 2 or more, R ₂ may be the same or different. R ₃ represents a hydrogen atom or a methoxy group. Examples of the compound represented by the general formula (6) include 4-methoxybenzaldehyde-1-methyl-1-phenylhydrazone and 2,4-dimethoxybenzaldehyde-1-
Benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone,
4-methoxybenzaldehyde-1-benzyl-1-
(4-methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1-phenylhydrazone, 4-dibenzylaminobenzaldehyde-
Examples include 1,1-diphenylhydrazone.

[0038]

Embedded image (Wherein, R ₁ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group, or a heterocyclic group;
_2, R ₃ may be different from each other in the same, represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, or a substituted or unsubstituted aralkyl group, and R _2, R ₃ may combine with each other to form a heterocyclic ring containing a nitrogen atom. R ₄ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a halogen atom. The compounds represented by the general formula (7) include, for example, 1,1
-Bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-
Bis (4-dibenzylaminophenyl) propane, 2,
2'-dimethyl-4,4'-bis (diethylamino)-
And triphenylmethane.

[0039]

Embedded image (Wherein, R ₁ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a phenyl group, and R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or a halogen atom.) Examples of the compound represented by 8) include N
-Ethyl-3,6-tetrabenzylaminocarbazole and the like.

[0040]

Embedded image (Wherein, R represents a hydrogen atom or a halogen atom;
Ar is a substituted or unsubstituted phenyl group, naphthyl group,
Represents an anthryl group or a carbazolyl group. As the compound represented by the general formula (9), for example, 9
-(4-diethylaminostyryl) anthracene, 9-
Brom-10- (4-diethylaminostyryl) anthracene and the like.

[0041]

Embedded image (Wherein, R ₁ represents a hydrogen atom, a halogen atom, a cyano group, an alkoxy group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and Ar is

[0042]

Embedded image Wherein R ₂ represents an alkyl group having 1 to 4 carbon atoms;
R ₃ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a dialkylamino group having 1 to 4 carbon atoms, and n is 1 or 2;
₃ may be the same or different, and R ₄ and R ₅ represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted benzyl group. The compounds represented by the general formula (10) include, for example, 9-
(4-dimethylaminobenzylidene) fluorene, 3-
(9-Fluorenylidene) -9-ethylcarbazole and the like.

[0043]

Embedded image (Wherein R represents a carbazolyl group, a pyridyl group, a thienyl group, an indolyl group, a furyl group, or a substituted or unsubstituted phenyl group, styryl group, naphthyl group,
Or an anthryl group, and in the case of substitution, these substituents are a dialkylamino group, an alkyl group, an alkoxy group,
A carboxy group or an ester thereof, a halogen atom, a cyano group, an aralkylamino group, an N-alkyl-N-aralkylamino group, an amino group, a nitro group, and an acetylamino group. As the compound represented by the general formula (11), for example,
Examples include 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene.

[0044]

Embedded image (Wherein, R ₁ represents a lower alkyl group, a substituted or unsubstituted phenyl group, or a benzyl group, and R ₂ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group, or a lower group. Represents an amino group substituted with an alkyl group or a benzyl group, and n represents an integer of 1 or 2.) Examples of the compound represented by the general formula (12) include:
Examples include 3-styryl-9-ethylcarbazole and 3- (4-methoxystyryl) -9-ethylcarbazole.

[0045]

Embedded image (Wherein R ₁ is a hydrogen atom, an alkyl group, an alkoxy group,
Or a halogen atom, R ₂ and R ₃ represent an alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group, and R ₄ represents a hydrogen atom, a lower alkyl group, or a substituted or unsubstituted phenyl group. And Ar represents a substituted or unsubstituted phenyl group or a naphthyl group. As the compound represented by the general formula (13), for example,
4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1-
(4-diphenylaminostyryl) naphthalene, 1-
(4-Diethylaminostyryl) naphthalene and the like.

[0046]

Embedded image (In the formula, n is an integer of 0 or 1, R ₁ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group;
r ₁ represents a substituted or unsubstituted aryl group; R ₅ represents an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group;

[0047]

Embedded image Represents a 9-anthryl group or a substituted or unsubstituted carbazolyl group, wherein R ₂ represents a hydrogen atom, an alkyl group,
An alkoxy group, a halogen atom, or

[0048]

Embedded image (Wherein, R ₃ and R ₄ represents an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ₃ and R ₄ may be the same or different, R ₄
May form a ring), m is an integer of 0, 1, 2 or 3, and when m is 2 or more, R ₂ may be the same or different. When n is 0, A and R ₁ may form a ring together. The compound represented by the general formula (14) includes, for example, 4′-
Diphenylamino-α-phenylstilbene, 4′-bis (4-methylphenyl) amino-α-phenylstilbene and the like.

[0049]

Embedded image (In the formula, R ₁ , R ₂ and R ₃ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a dialkylamino group, or a halogen atom, and n represents 0 or 1.) Formula (15) Examples of the compound include, for example,
1-phenyl-3- (4-diethylaminostyryl)-
5- (4-diethylaminophenyl) pyrazolin, 1-
Phenyl-3- (4-dimethylaminostyryl) -5
(4-dimethylaminophenyl) pyrazoline and the like.

[0050]

Embedded image (Wherein R ₁ and R ₂ represent an alkyl group including a substituted alkyl group, or a substituted or unsubstituted aryl group;
Represents a substituted amino group, a substituted or unsubstituted aryl group or an allyl group. As the compound represented by the general formula (16), for example,
2,5-bis (4-diethylaminophenyl) -1,
3,4-oxadiazole, 2-N, N-diphenylamino-5- (diethylaminophenyl) -1,3,4-
Oxadiazole, 2- (4-dimethylaminophenyl) -5- (4-diethylaminophenyl) 1,3,4
Oxadiazole and the like.

[0051]

Embedded image (Wherein, X represents a hydrogen atom, a lower alkyl group, or a halogen atom, R represents an alkyl group including a substituted alkyl group,
Or A represents a substituted or unsubstituted aryl group, and A represents a substituted amino group or a substituted or unsubstituted aryl group. As the compound represented by the general formula (17), for example,
2-N, N-diphenylamino-5- (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole, 2- (4-diethylaminophenyl) -5- (N-
Ethylcarbazol-3-yl) -1,3,4-oxadiazole and the like.

[0052]

Embedded image (Wherein, R ₁ represents a lower alkyl group, a lower alkoxy group or a halogen atom, n represents an integer of 0 to 4,
₂ and R ₃ may be the same or different and represent a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom. Examples of the benzidine compound represented by the general formula (18) include N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl]-
4,4′-diamine, 3,3′-dimethyl-N, N,
N ', N'-tetrakis (4-methylphenyl)-
[1,1′-biphenyl] -4,4′-diamine and the like.

[0053]

Embedded image (Wherein R ₁ , R ₃ and R ₄ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted R ₂ represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or a halogen atom, provided that R ₁ ,
Except when R ₂ , R ₃ and R ₄ are all hydrogen atoms.
K, l, m and n are integers of ₁ , ₂ , 3 or 4, and when each is an integer of 2, 3 or 4, the above R ₁ , R ₂ ,
R ₃ and R ₄ may be the same or different. Examples of the biphenylamine compound represented by the general formula (19) include 4′-methoxy-N, N-diphenyl- [1,1′-biphenyl] -4-amine and 4′-methyl-N, N ′ -Bis (4-methylphenyl)-[1,
1'-biphenyl] -4-amine, 4'-methoxy-
N, N'-bis (4-methylphenyl)-[1,1'-
Biphenyl] -4-amine and the like.

[0054]

Embedded image (Wherein, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms, and R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group,
Represents a substituted or unsubstituted phenyl group, which may be the same or different. Examples of the triarylamine compound represented by the general formula (20) include 1-phenylaminopyrene and 1-di (p-triamino) pyrene.

[0055]

Embedded image Examples of the diolefin aromatic compound represented by the general formula (21) include 1,4-bis (4-diphenylaminostyryl) benzene and 1,4-bis [4-di (p-tolyl) aminostyryl] benzene Etc.

[0056]

Embedded image (In the formula, Ar represents an aromatic hydrocarbon group, R represents a hydrogen atom, a substituted or unsubstituted alkyl group or an aryl group. N is 0 or 1, m is 1 or 2, and n =
When 0 and m = 1, Ar and R may form a ring together. Examples of the styrylpyrene compound represented by the general formula (22) include 1- (4-diphenylaminostyryl)
Pyrene, 1- [4-di (p-tolyl) aminostyryl]
There is pyrene. Among these, those having good electrostatic characteristics of the photoreceptor are appropriately selected and used.

The charge transport layer (20) together with the charge transport material
Polystyrene, as the binder resin used for
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, Thermoplastic or thermosetting resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin can be used, but they are protected so as not to generate an interface barrier with the protective layer (21). It is necessary to select a resin having a high affinity for the resin used in the layer. Preferably, it is the same as the protective layer (21).

As the coating solvent, tetrahydrofuran,
Dioxane, toluene, 2-butanone, monochlorobenzene, dichloroethane, methylene chloride and the like are used. The thickness of the charge transport layer (20) is suitably from 5 to 100 μm. In the present invention, a plasticizer may be added to the charge transport layer (20). As the plasticizer, those used as general plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is suitably about 0 to 30% by weight based on the binder resin.

Next, the case where the photosensitive layer (15) has a single-layer structure will be described. In this case as well, similarly to the case of the function separation type, a charge generating substance and a charge transport substance are used. That is,
It can be formed by dissolving or dispersing at least the charge generation material and the charge transport material in a suitable solvent together with a binder resin, and applying and drying this. Further, a plasticizer or the like can be added as necessary. As the binder resin, the binder resin described for the charge transport layer (19) can be used as it is, or the binder resin described for the charge generation layer (17) may be mixed.
The thickness of the single-layer photosensitive layer is suitably from 5 to 100 μm.

The electrophotographic photosensitive member of the present invention may have an undercoat layer between the conductive support (11) and the photosensitive layer. The undercoat layer generally contains a resin as a main component. However, in consideration of applying the photosensitive layer on the undercoat layer with a solvent, the resin should be a resin having high solubility resistance to a general organic solvent. 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.

The undercoat layer may contain fine powder of a metal oxide exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc. for preventing moire and reducing residual potential. Good. These undercoat layers can be formed using an appropriate solvent and a coating method as in the above-described photosensitive layer. Further, a silane coupling agent, a titanium coupling agent, a chromium coupling agent and the like can be used as a subbing layer of the electrophotographic photoreceptor in the present invention. For example, a metal oxide layer formed by a sol-gel method or the like can be used. Useful.

In addition, the undercoat layer of the present invention has an Al ₂ O ₃
Provided by anodic oxidation, organic substances such as polyparaxylylene (parylene), SiO, SnO ₂ , TiO ₂ , I
An inorganic substance such as TO or CeO ₂ provided by a vacuum thin film manufacturing method can also be used favorably. The thickness of the undercoat layer is 0 to 5 μm
Is appropriate.

The coefficient of friction of the surface of the photoreceptor thus manufactured preferably has a static friction coefficient of 0.3 or less. If the coefficient of static friction exceeds this, the load between the cleaning blade and the cleaning blade becomes large, and unusual noise is generated and the cleaning blade is entangled. Further, in a full-color electrophotographic apparatus using an intermediate transfer member, the static friction coefficient of the photosensitive member is 0.3
If it exceeds, an insect-eating image is easily generated, which is not preferable.

Next, an image forming apparatus using the above photosensitive member will be described. FIG. 4 shows an outline of an example of the apparatus. The photoreceptor (41) is charged by a charger (42) first, and then is exposed (43) to form an electrostatic latent image. The electrostatic latent image is developed by a developing device (44) with toner charged to a predetermined charge polarity and charge amount.
It is visualized. This toner image is transferred to the transfer paper (45) in the transfer section (46). Thereafter, the untransferred toner is removed from the photoreceptor by the cleaning member (47), and one process is completed through a charge removal process using a charge removal lamp (48). The device is not particularly limited to this. For example, the charger and the transfer device are not limited to the charging roller and the transfer roller as shown in the figure, and a corona charger may be used. In this device,
The photoreceptor (41) is mainly worn by being rubbed with the transfer paper (45), the cleaning member (47) and the like via the toner. In the present invention, by using the photoconductor having the above-described configuration, the coefficient of friction of the photoconductor surface can be reduced, and the amount of wear can be suppressed.

Next, FIG. 5 shows an example of a full-color device using an intermediate transfer member. In the apparatus of this example, the latent image formed on the photoreceptor (51) is first visualized by the developing unit (55-1) for the first color, and then is applied to the intermediate transfer body (61). The image is transferred to the intermediate transfer member at the contact portion. This transfer is called primary transfer. After the primary transfer, the photoreceptor
The untransferred toner is cleaned by the cleaning members (58) and (59), and the process proceeds to the second color image forming process through the charge removing process by the charge removing lamp (60). In the case of full color, this process is repeated for three or four colors to form a full color image on the intermediate transfer member.

Next, the image formed on the intermediate transfer member is collectively transferred onto a transfer paper (62). This transfer is called secondary transfer. Here, the transfer bias voltage is applied to the transfer roller (63).
Is applied. The transfer paper is then output as a full-color image through a fixing process. In this device,
The photoreceptor transfers the toner image to an intermediate transfer member instead of paper.

The intermediate transfer member is made of a material having relatively good releasability in order to transfer the received toner image to paper in the secondary transfer in the next step. For this reason, if the surface characteristics of the photoreceptor are poor, a so-called insect-eating image in which a part of the image is not transferred and remains on the photoreceptor during the primary transfer is generated. Specifically, it is likely to occur when the friction coefficient of the photoconductor is larger than 0.3. In the present invention, by using the photoconductor having the above-described configuration, the friction coefficient on the surface of the photoconductor is reduced, the amount of wear is suppressed, and the friction coefficient does not change over time.

[0068]

The present invention will be specifically described below with reference to examples. Example 1 <Preparation of Photoconductor> Titanium oxide (CR-EL manufactured by Ishihara Sangyo Co., Ltd.)
75 parts by weight (purity 99.7% by weight), alkyd resin (Beccolite M6401-50- manufactured by Dainippon Ink and Chemicals, Inc.)
S (50% solid content)), 15 parts by weight, melamine resin (Super Beckamine L-121-6 manufactured by Dainippon Ink and Chemicals, Inc.)
0 (solid content: 60%)) and a mixture consisting of 10 parts by weight of methyl ethyl ketone and 100 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 72 hours to prepare a coating liquid for an undercoat layer. This is φ30mm
Dipping on aluminum tube of
After drying for 3 minutes, an undercoat layer having a thickness of 3 μm was formed.

Subsequently, 10 parts by weight of a trisazo pigment having the following structural formula was added to a resin solution prepared by dissolving 4 parts by weight of polyvinyl butyral (BM-2, manufactured by Sekisui Chemical Co., Ltd.) in 150 parts by weight of cyclohexanone. For 48 hours. After the dispersion, cyclohexanone 21
0 parts by weight were added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This is applied on the intermediate layer,
Drying was performed at 10 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

[0070]

Embedded image

Next, 2 parts by weight of polytetrafluoroethylene fine particles (Lubron L2, Daikin Industries, Ltd.) were added to 100 parts by weight of dichloromethane, and dispersed for 2 hours by a sand mill using 1 mmφ glass beads. In this dispersion, 7 parts by weight of a charge transporting substance represented by the structural formula (1-2) in Table 1, 10 parts by weight of a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Company, Iupilon Z300), and silicon oil (manufactured by Shin-Etsu Chemical Co., Ltd.) , KF-50) in an amount of 0.002 parts by weight to prepare a charge transport layer coating solution. This was applied on the charge generation layer and dried at 130 ° C. for 15 minutes to form a charge transport layer having a thickness of 20 μm. Thus, an electrophotographic photoreceptor (photoreceptor 1) of Example 1 was obtained.

<Running evaluation by actual machine> The photoconductor prepared above was used as a copying machine manufactured by Ricoh, image MF250.
Table 4 shows the results before and after output of 100,000 copies of the test image.

Example 2 A photoreceptor 2 was prepared in the same manner as in Example 1, except that the charge transporting material represented by the structural formula (2-5) in Table 2 was used instead of the charge transporting material. Example 3 In place of the charge transport material of Example 1, the structural formula (3
Photoconductor 3 was prepared in the same manner as in Example 1, except that the charge transporting material represented by -8) was used. Example 4 A photoconductor 4 was prepared in the same manner as in Example 1, except that the addition amount of the polytetrafluoroethylene fine particles in Example 1 was changed to 1 part by weight. Example 5 A photoconductor 5 was prepared in the same manner as in Example 1, except that the addition amount of the polytetrafluoroethylene fine particles in Example 1 was changed to 0.5 part by weight.

Comparative Example 1 A photoreceptor 6 was prepared in the same manner as in Example 1 except that the polytetrafluoroethylene fine particles were not added. Comparative Example 2 A photoconductor 7 was prepared in the same manner as in Example 1, except that the substance having the following structural formula was used instead of the charge transporting material of Example 1.

[0075]

Embedded image Comparative Example 3 A photoconductor 8 was prepared in the same manner as in Example 1, except that the substance having the following structural formula was used instead of the charge transporting substance of Example 1.

[0076]

Embedded image

[0077]

[Table 4]

Next, each photoreceptor was prepared by coating the same prescription as the photoreceptors prepared in the above Examples and Comparative Examples on a φ80 aluminum tube. The same measurement was performed when the A3 full-color image was mounted on a Ricoh full-color copying machine Printer 650 of the intermediate transfer belt type and 10,000 copies were output. At this time (at the time of output of 10,000 sheets), abnormalities (worm worms) occurring in the image were observed. -Insect-eating rank 5: No worm-eating Rank 4: Insect-like worms like small needle holes are found at one or two places. Rank 3: Many insect bites like small needle holes are seen. Rank 2: A large worm is found. Rank 1: Many large worms are seen. Table 5 shows the results.

[0079]

[Table 5]

[0080]

As described above, as is apparent from the detailed and specific description, by using the photoreceptor of the present invention,
Even when used for a long time, the coefficient of friction of the surface can be kept low and the abrasion resistance can be excellent. Furthermore, by using the photoreceptor of the present invention, it is possible to provide an electrophotographic apparatus which is excellent in transferability and cleaning properties over a long period of time and which provides high quality images. Further, even in a full-color electrophotographic apparatus using an intermediate transfer member system, it is possible to provide a high-quality image forming apparatus in which no wormy image is generated for a long period of time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a single-layer photoreceptor of the present invention.

FIG. 2 is a cross-sectional view illustrating a laminated photoconductor of the present invention.

FIG. 3 is a cross-sectional view illustrating another laminated photoconductor of the present invention.

FIG. 4 is a diagram illustrating an outline of an image forming apparatus of the present invention.

FIG. 5 is a diagram illustrating an outline of a full-color image forming apparatus using the intermediate transfer member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Conductive support 15 Photosensitive layer 17 Charge generation layer 19 Charge transport layer 20 Charge transport layer 21 Protective layer 41 Photoconductor 42 Charger 43 Exposure 44 Developer 45 Transfer paper 46 Transfer unit 47 Cleaning member 48 Static elimination lamp 51 Photoconductor 52 Charging unit 53 Exposure unit 55 Developing unit 56 Primary transfer unit 57 Static elimination unit 58 Cleaning member 59 Cleaning member 60 Static elimination lamp 61 Intermediate transfer body 62 Transfer paper 63 Transfer roller 64 Cleaning member

Claims (7)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the outermost layer of the electrophotographic photoreceptor comprises a resin layer containing a charge transport material having a fluoroalkyl group and fine particles of fluororesin. An electrophotographic photoreceptor, comprising: 2. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting material having a fluoroalkyl group is a substance represented by the following general formula (1). Embedded image (Wherein, R _{1 to} R ₄ represent a substituted or unsubstituted aryl group,
Rf is -C _n F _2n-1 and (n is integer from 6-12), R represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. ) 3. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting material having a fluoroalkyl group is a substance represented by the following general formula (2). Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.) 4. The electrophotographic photoreceptor according to claim 1, wherein the charge transport material having a fluoroalkyl group is a substance represented by the following general formula (3). Embedded image (In the formula, R _{1 to} R ₄ represent a substituted or unsubstituted alkyl group or aryl group.) 5. The electrophotographic photosensitive member according to claim 1, wherein the static friction coefficient of the surface of the photosensitive member is 0.3 or less. 6. An electrophotographic photosensitive member comprising a photosensitive layer provided on a conductive support, and an outermost layer comprising a resin layer containing a charge transporting material having a fluoroalkyl group and fluororesin fine particles. Image forming apparatus. 7. A plurality of visible color-developed images sequentially formed on an image carrier by toner are superimposed sequentially on an intermediate transfer body running endlessly and primary-transferred, and the primary transfer on the intermediate transfer body is performed. An intermediate transfer type full-color image forming apparatus for batch-transferring a transfer image to a transfer material, wherein the image carrier is the photoconductor according to any one of claims 1 to 5. Full color image forming device.