JP2002268258A - Electrophotographic photoreceptor and process cartridge using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high sensitivity and high durability electrophotographic photoreceptor which retains high image quality due to improved wear resistance and is free of defective cleaning even after repeated use. SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer on an electrically conductive substrate, an electric charge transferring vinyl polymer and a filler are contained in at least one layer from the surface side remotest from the electrically conductive substrate.

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 an image forming apparatus using the same, and more particularly, to a long-life electrophotographic photosensitive member, and more particularly, to an electrophotographic photosensitive member of the present invention and an electrophotographic device using the same. The process is applied to copying machines, facsimile machines, laser printers, direct digital plate making machines, and the like.

[0002]

2. Description of the Related Art In recent years, as the speed, size, and image quality of electrophotographic copying machines, electrophotographic printers, and the like have increased, photoconductors have been required to have higher durability. In the electrophotographic process, the durability of the photoreceptor is deteriorated due to mechanical and chemical actions in repeated processes of charging, exposure, development, transfer, and cleaning. The mechanical deterioration causes wear and damage of the photoconductor, and the chemical deterioration causes oxidative deterioration of the binder resin and the charge transfer material due to ozone and NOx, and image quality deterioration due to deposits and the like. In addition, as described above, with the increase in speed and miniaturization, the surface of the photoreceptor is severely damaged by high-energy arc discharge due to the adoption of the roller charging method, and the deterioration of mechanical characteristics is increased. The photoreceptor has been reduced in diameter, and the use conditions in the electrophotographic process have become severe.Especially, the rubber blade is used in the cleaning section, and for sufficient cleaning, the rubber hardness and the contact pressure must be increased. Abrasion of the photoreceptor, turning of the rubber blade, and blade squeal (abnormal noise) occur. In the case of high image quality, cleaning failure occurs due to finer toner particles, and there has been a demand for improved releasability of the toner from the photoreceptor. The photoreceptor also wears out, causing problems such as potential fluctuations and sensitivity fluctuations, causing the color balance of a color image to be lost and causing problems in color reproducibility. For this purpose, it has been proposed to lower the coefficient of friction of the photoreceptor surface.

With respect to the surface lubricity, it has been proposed to add a surfactant of a fluorine compound or a polysiloxane compound. In particular, Japanese Patent Application Laid-Open No. 61-95358 discloses the addition of a graft polymer of a silicone compound. Kaisho 61
JP-A-189559, JP-A-62-75460, JP-A-62-205356, JP-A-2-15
No. 6246 and JP-A-5-323646. These surface lubricants reduce the surface friction coefficient. However, the compatibility with the binder resin or the charge transfer material is poor, and the coating film becomes cloudy and loses transparency. Therefore, although the initial repeated rubbing is effective, the friction coefficient is increased and the reduction of the friction is not continued after about 1000 times, and the abrasion of the photoreceptor, entangling of the blade, and abnormal noise occur. This is presumably because the polysiloxane chains of the low friction segment are localized on the surface and are quickly released from the film. An increase in the density of the low-friction segments in the film makes it possible to reduce the friction of the entire bulk, but optical defects due to the opacity of the coating caused a decrease in image quality and a change in image density due to an increase in residual potential.

[0004]

SUMMARY OF THE INVENTION A first object of the present invention is to maintain high image quality by improving abrasion resistance, and a second object is to provide high sensitivity and high durability without defective cleaning even when used repeatedly. An object of the present invention is to provide an electrophotographic photosensitive member.

[0005]

According to the present invention, in order to solve the above problems, in an electrophotographic photosensitive member having a photosensitive layer on a conductive substrate, at least one layer from the surface farthest from the conductive substrate is provided. A copolymer of a charge-transporting vinyl compound and an acrylic or methacrylic terminal-modified polysiloxane and a filler.

That is, the above-mentioned problem is solved by the present invention which relates to (1) an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, wherein at least one layer is provided from the surface farthest from the conductive substrate.
(2) “In an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, at least one layer from the surface farthest from the conductive substrate” , Acrylic having a triarylamine structure, or methacrylic compound and one terminal acrylic,
Or, an electrophotographic photoreceptor containing a copolymer of a methacryl-modified polysiloxane compound and an inorganic filler or an organic filler ”, (3)“ acrylic or methacrylic compounds having a triarylamine structure of the copolymer are generally used. In the above item (1), the acrylic or methacrylic polysiloxane compound represented by the formula (1) or the general formula (2) is a copolymer represented by the general formula (3). Electrophotographic photoreceptor as described above;

[0007]

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[0008]

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[0009]

Embedded image(Where R¹Is hydrogen, methyl, Ar¹, Ar^TwoIs Arile
And represents an Ar group^Three, Ar ^FourMay be the same or different
Represents an unsubstituted aryl group. R^TwoIs hydrogen, methyl,
R^Three, R^Four, R^Five, R⁶, R⁷Represents an alkyl group or a phenyl group
1 is an integer up to 0 or 6, j is 0 or 1, m
Represents 5-1000. ) ", (4)" The following general formula
One or more of the monomers represented by (4)
Wherein the copolymer is a copolymerized copolymer.
The electrophotographic photoreceptor according to the item (2);

[0010]

Embedded image (Z is a substituted or unsubstituted aryl group, -COOR
^{In 8} , R ⁸ represents hydrogen, a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group, a cyclic ether group, or a hydroxy group-substituted alkyl group. And (5) an electrophotographic photosensitive member having a photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate directly or via an undercoat layer, wherein the charge transport layer is at least a charge transport material. And (6) an electrophotographic photoreceptor characterized in that the content of the filler in the charge transport layer is large on the surface side farthest from the conductive substrate. (4) The electrophotographic photoreceptor according to (4), wherein the electrophotographic photoreceptor is formed by laminating a layer made of a molecular charge transport material and a binder resin and a layer made of a charge transport binder resin and a filler.
(7) “Electrophotographic photoreceptor according to any one of the above items (1) to (6), wherein the inorganic filler contained in the charge transport layer is titanium oxide”, (8)
“The electrophotographic photoreceptor according to any one of the above items (1) to (6), wherein the inorganic filler contained in the charge transport layer is silica”, (9) “the charge transport layer”. Wherein the inorganic filler contained in the electrophotographic photosensitive member according to any one of the above items (1) to (6) is characterized in that the inorganic filler is contained in the charge transport layer. The electrophotographic photoreceptor according to any one of the above items (1) to (6), wherein the organic filler is a crosslinked polymer compound of a polyfunctional vinyl group or a polyfunctional crosslinked polycondensation compound. (11) The electrophotographic photoreceptor according to the above (5) or (6), wherein the charge transport layer is formed by a multiple coating method.

[0011] The object of the present invention is to provide an electrophotographic apparatus having an electrophotographic photosensitive member, a charging means, an image exposing means, a developing means, and a transferring means, wherein (13) An electrophotographic apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of (1) to (11). A process cartridge for an electrophotographic apparatus integrally supporting at least one means selected from the group consisting of the above, wherein the electrophotographic photosensitive member is any one of the above items (1) to (11). A process cartridge which uses an electrophotographic photosensitive member and is detachable from an electrophotographic apparatus main body. "

The present invention is intended to ensure transparency and prevent a rise in residual potential by adding a large amount of low friction segments to the photosensitive layer, to prevent a rise in frictional resistance even in repeated rubbing, and to reverse the cleaning blade. Eliminating poor cleaning, preventing abnormal noise, and preventing surface deterioration due to heat generation on the surface of the photoreceptor due to high frictional resistance, and further including a filler to improve the abrasion resistance of the photoreceptor. The charge transfer vinyl compound is a copolymer of an acrylic or methacrylic ester having a triarylamine structure represented by the following general formulas (1) and (2) and a terminal acrylic or methacryl-modified polysiloxane represented by the following general formula (3) It is.

[0013]

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[0014]

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[0015]

Embedded imageR¹Represents hydrogen or a methyl group;^TwoIs hydrogen, methyl, R
^Three, R^Four, R^Five, R⁶, R ⁷Represents an alkyl group or a phenyl group
Where l is an integer up to 0 or 6, j is 0 or 1, and m is
Represents 5 to 1000. Ar¹, Ar^TwoIs replaced or unplaced
Arylene aryl group, Ar^Three, Ar^FourIs replaced or unsubstituted
And X is a single bond, a substituted or unsubstituted aryl group.
A kylene group, a substituted or unsubstituted cycloalkylene group,
Substituted or unsubstituted alkylene ether group, oxygen atom
, Sulfur atom, vinylene group
You may.

Specific Examples of General Formulas (1) and (2) In the above general formulas (1) and (2), Ar ³ and Ar ⁴ are aryl groups, and specific examples include a non-condensed carbocyclic group and a condensed Examples include a polycyclic hydrocarbon group and a heterocyclic group. As the condensed polycyclic hydrocarbon group, those having preferably 18 or less carbon atoms forming a ring, for example, pentanyl group, indenyl group, naphthyl group, azulenyl group, heptalenyl group, biphenylenyl group, as-indacenyl group , S-indacenyl group, fluorenyl group, acenaphthylenyl group,
Examples include a preadenyl group, an acenaphthenyl group, a phenalenyl group, a phenanthryl group, an anthryl group, a fluoranthenyl group, an acephenanthrenyl group, an aceanthrenyl group, a triphenyler group, a pyrenyl group, a chrysenyl group, and a naphthacenyl group.

The non-condensed carbocyclic group may be a monovalent group of a monocyclic hydrocarbon compound such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenylthioether and diphenylsulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene. , Diphenylalkyne, triphenylmethane,
Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring-assembled hydrocarbon compounds such as 9,9-diphenylfluorene Monovalent groups are exemplified.

Furthermore, when it is a heterocyclic group, specific examples include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole and thiadiazole.

The aryl groups represented by Ar ³ and Ar ⁴ may have the following substituents. (1) Halogen atom, cyano group, nitro group. (2) an alkyl group. Preferably, C ₁ -C ₁₂ especially C ₁
To C ₈ , more preferably a C _{1 to} C ₄ linear or branched alkyl group. These alkyl groups further include a fluorine atom, a hydroxyl group, a cyano group, a C _{1 to} C ₄ alkoxy group, and a phenyl group. or halogen atom, an alkyl group or alkoxy group of C ₁ -C ₄ of C1 -C4, may contain substituted phenyl group. Specifically, a methyl group, an ethyl group, an n-butyl group, an i-propyl group, a t-butyl group,
s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl group, 2
-Cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4
-Phenylbenzyl group and the like. (3) an alkoxy group (—OR ² ). R ² represents an alkyl group defined in (2). Specifically, methoxy, ethoxy, n-propoxy, i-propoxy, t-butoxy, n-butoxy, s-butoxy, i-butoxy, 2-hydroxyethoxy, benzyloxy ,
A trifluoromethoxy group. (4) an aryloxy group. Examples of the aryl group include a phenyl group and a naphthyl group. It may contain a C ₁ -C ₄ alkoxy group, a C ₁ -C ₄ alkyl group or a halogen atom as a substituent. Specifically, a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group,
-Methoxyphenoxy group, 4-methylphenoxy group and the like. (5) An alkyl mercapto group or an aryl mercapto group. Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group. (6)

[0020]

Embedded image (Wherein R ⁹ and R ¹⁰ each independently represent a hydrogen atom, an alkyl group or an aryl group as defined in (2), and examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. May contain a C ₁ -C ₄ alkoxy group, a C ₁ -C ₄ alkyl group or a halogen atom as a substituent. R ⁹ and R ¹⁰ may jointly form a ring) Represents an amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group, pyrrolidino group And the like. (7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group. (8) a substituted or unsubstituted styryl group, a substituted or unsubstituted β-
Phenylstyryl group diphenylaminophenyl group, ditolylaminophenyl group and the like.

The arylene groups represented by Ar ¹ and Ar ² are divalent groups derived from the aryl groups represented by Ar ³ and Ar ⁴ . The X is

[0022]

Embedded image (R ¹¹ is hydrogen, an alkyl group [an alkyl group defined by the general formula (2)], an aryl group [Ar ³ , A
an aryl group represented by r ⁴ ], a represents 2 to 4, and b represents 1 or 2. R ³ , R ⁴ , R ⁵ , R ⁶ , and R ^{7 each} represent an alkyl group (an alkyl group defined by the general formula (2)), a phenyl group, and acryl or methacryl having a triarylamine structure. The compounds are described in JP-A-5-202135, and copolymerization of these monomers and polysiloxane modified with an acrylic terminal is also possible.

[0023] The polysiloxane modified with an acrylic terminal is disclosed in JP-A-58-167606 and JP-A-59-12647.
No. 8 is synthesized by the method described therein. As commercial products, terminal acrylic-modified polysiloxanes are available from Shin-Etsu Chemical Co., Ltd., X-22-174DX, Toray Dow Corning Co., Ltd., BX16-192, and HU-
Commercially available under the trademark 050. These polysiloxane chain lengths can be controlled. Hereinafter, specific examples are shown, but the compounds of the present invention are not limited thereto.

[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

Embedded image In the copolymer species represented by the general formula (4), Z is a substituted or unsubstituted aryl group, —COOR ⁸ , R ⁸ is hydrogen,
It represents a substituted or unsubstituted linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group, a cyclic ether group, or a hydroxy-substituted alkyl group.

For example, methacrylic acid, acrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate,
Representative examples include benzyl methacrylate, tetrahydrofurfuryl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, phenyl methacrylate, octafluoropentyl acrylate, heptadecafluorodecyl methacrylate, tetrafluoropropyl methacrylate, styrene and α-methylstyrene.

These triarylamine monomers and siloxane monomers can be polymerized by arbitrarily changing the copolymerization ratio. Polymerization uses aromatic solvents such as toluene, ketones such as MIBK, ether solvents such as dioxane, and initiators include azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile, and benzoyl peroxide and the like. The reaction is carried out using a peroxide under a nitrogen stream. In addition, it can be copolymerized with other monomers, and can be radically copolymerized with methyl methacrylate, butyl methacrylate, styrene, etc. to impart dispersion stability, film properties, adhesion, and flexibility. The polymerization method is solution polymerization, but is not particularly limited to bulk polymerization, emulsion polymerization and the like. In the case of solution polymerization, the monomer solid content concentration is preferably 10% or more. After the end, it re-sediments and can be taken out as an individual. The molecular weight is preferably 10,000 or more in terms of polystyrene by GPC.

Examples of the inorganic filler include titanium oxide, silica, alumina, zinc oxide, barium titanate, and zirconia, which are obtained by a gas phase method or a precipitation method, and are not subjected to surface treatment with silicone, higher fatty acids, or other inorganic substances. Processing may be sufficient. As the organic filler, one obtained by three-dimensionally cross-linking dimethysiloxane or the like, a vinyl monomer, styrene, methyl methacrylate, or the like, a bifunctional vinyl monomer, divinyl benzene, one obtained by cross-linking with ethylene glycol dimethacrylate, or a phenol resin,
It is a three-dimensional cross-linking substance such as melamine resin, which is insoluble in the coating organic solvent. The primary particle diameter of these fillers is 1
μm or less, preferably 0.8 μm. Filler is binder resin and coating solvent tetrahydrofuran,
It can be formed by dispersing using a solvent such as cyclohexanone, dioxane, dichloroethane, butanone or the like with a ball mill, an attritor, a sand mill or the like, diluting the dispersion liquid appropriately, and applying the diluted liquid. The amount of the filler is 10 to 60% by weight based on the binder resin, preferably 20 to 50%.
% Is preferred. If it is less, the wear resistance is not enough,
On the other hand, if it is too high, the transparency of the photosensitive layer is impaired.

A low molecular charge transport material may be added to the filler-containing layer, and the amount is 10 to 70% by weight, preferably 20 to 50% by weight, based on the binder resin. The thickness of the filler-containing layer is 0.5 to 6 μm, preferably 1 to 5 μm.

Next, the photosensitive member will be described. Examples of the conductive support include those having a conductivity of 10 ¹⁰ Ω or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron, and oxides such as tin oxide and indium oxide. Object coated with film or cylindrical plastic, paper or the like by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. I. , I .; I. After forming into a tube by a method such as extrusion or drawing, a tube or the like whose surface is treated by cutting, superfinishing, polishing, or the like can be used.

The photosensitive layer in the present invention may be 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 will be described.
The charge generation layer is a layer containing a charge generation substance as a main component, and a binder resin may be used as needed. As the charge generation substance, an inorganic material and an organic material can be used. Inorganic materials include crystalline selenium, amorphous
Selenium, selenium-tellurium, selenium-tellurium-halogen,
A selenium-arsenic compound, amorphous silicon, and the like can be given. 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, phthalocyanine pigments such as metal phthalocyanine and non-metal 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, i Jigoido based pigments, and bisbenzimidazole pigments. These charge generating substances can be used alone or as a mixture of two or more.

The binder resin optionally used in the charge generation layer 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
It can be used as a mixture of more than one species. Further, a low molecular charge transport material may be added as needed.

Examples of the hole transporting material include the following electron donating materials, which 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 transporting substances can be used alone or as a mixture of two or more kinds.

As a method of forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system are mainly mentioned. The former method includes a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method,
Reactive sputtering, CVD, or the like is used, and the above-described inorganic and organic materials can be formed favorably. In addition, in order to provide a charge generation layer by a casting method described later, if necessary, the above-mentioned inorganic or organic charge generation substance is used together with a binder resin together with tetrahydrofuran,
It can be formed by dispersing using a solvent such as cyclohexanone, dioxane, dichloroethane, butanone or the like with a ball mill, an attritor, a sand mill or the like, diluting the dispersion liquid appropriately, and applying the diluted liquid. 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 will be described. The low-molecular-weight charge transport materials used in the charge transport layer include oxazole derivatives and oxadiazole derivatives (JP-A-52-13).
No. 9065, JP-A-52-139066) Imidazole derivative, triphenylamine derivative (JP-A-1-77839), benzidine derivative (JP-B-58-32372), α-phenylstilbene derivative (Described in JP-A-57-73075), hydrazone derivatives (JP-A-55-154955, JP-A-55-156954, and JP-A-55-156954).
JP-A-52063, JP-A-56-81850), triphenylmethane derivatives (JP-B-51-109)
No. 83), anthracene derivatives (Japanese Unexamined Patent Publication No.
No. 94829), styryl derivatives (Japanese Unexamined Patent Publication No. Sho 56)
Nos. 29245 and 58-198043), carbazole derivatives (described in JP-A-58-558552), pyrene derivatives (described in JP-A-2-94812), and the like. Can be used in combination.

Further, as a polymer charge transport material, Japanese Patent Application Laid-Open No.
-319120, JP-A-7-258399, JP-A-8-269183, JP-A-9-151
248, JP-A-9-71642,
JP-A-104746, JP-A-9-272735, JP-A-241369, JP-A-9-23536
7, JP-A-9-87376, JP-A-9-1
No. 10976, JP-A-9-268226, JP-A-9-221544, JP-A-9-227669
JP, JP-A-9-157378, JP-A-9-3
Polymer charge transport materials described in JP-A-02084, JP-A-9-32085, and JP-A-5-202135 can be used.

The thickness of the charge transport layer is suitably about 5 to 100 μm, and preferably about 10 to 40 μm. In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer. 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 thereof is suitably about 0 to 30 parts by weight based on 100 parts by weight of the binder resin. It is.

Next, the case where the photosensitive layer has a single-layer structure will be described. When a single-layer photosensitive layer is provided by a casting method, a function-separated type layer composed of a charge-generating substance, a low-molecular compound, and a binder resin is often used. That is, the above-mentioned materials can be used as the charge generating substance and the charge transporting substance. If necessary, a plasticizer or a leveling agent may be added. Further, as the binder resin that can be used as necessary, the binder resin described above for the charge transport layer may be used as it is, or the binder resin described for the charge generation layer may be mixed and used. The thickness of the single-layer photoreceptor is suitably about 5 to 100 μm, and preferably about 10 to 40 μm.

The electrophotographic photosensitive member used in the present invention includes:
An undercoat layer can be provided between the conductive support and the photosensitive layer (the charge generation layer in the case of a laminate type). The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving coating properties of the upper layer, reducing residual potential, and the like. The undercoat layer generally contains a resin as a main component,
Considering that these resins are coated on the photosensitive layer with a solvent, it is desirable that these resins have high solubility in general organic solvents. 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. Also, titanium oxide, silica, alumina,
Fine powders such as metal oxides such as zirconium oxide, tin oxide, and indium oxide, or metal sulfides and metal nitrides may be added. These undercoat layers can be formed using an appropriate solvent and a coating method as in the case of the photosensitive layer in the previous operation. Further, as the undercoat 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 undercoat layer of the present invention is provided with Al ₂ O ₃ by anodic oxidation, an organic substance such as polyparaxylylene (parylene), SiO,
An inorganic material such as SnO ₂ , TiO ₂ , ITO, CeO ₂ or the like provided by a vacuum thin film manufacturing method can also be used favorably. The thickness of the undercoat layer is suitably from 0 to 5 μm.

In the present invention, an antioxidant can be added for the purpose of improving 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 compound 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] crylic ester, tocopherols 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 fats, and commercially available products can be easily obtained. 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.

FIG. 1 is a schematic view of an electrophotographic apparatus and a process cartridge for the electrophotographic apparatus of the present invention. The photoreceptor (11) has a drum shape, but has a sheet shape,
It may be in the form of an endless belt. Charger (13), pre-transfer charger (17), transfer charger (20), separation charger (21), and pre-cleaning charger (23) include corotron, scorotron, solid state charger (solid state charger), and charging. A known means such as a roller is used. As the transfer means, generally, the above-mentioned charger can be used, but as shown in the figure, a combination of a transfer charger and a separation charger is effective.

In the image exposure section (15), 400 to 450 n
An LD or LED having an oscillation wavelength in the range of m is used. In addition, as a light source such as a static elimination lamp (12), any light-emitting material such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, an LED, an LD, and an electroluminescent element (EL) can be used.
To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. At this time, the beam system of the image exposure unit and the writing light source is preferably 10 to 30 μm in order to achieve a high resolution equivalent to 1200 to 2400 dpi. Such a light source or the like irradiates the photoreceptor with light by providing a transfer step using light irradiation, a charge removal step, a cleaning step, or a pre-exposure step in addition to the step shown in FIG.

The photoconductor (1) is developed by the developing unit (16).
1) The developed toner is transferred to the transfer paper (19), but not all of the toner is transferred.
1) Toner remaining on the top is also generated. Such toner is removed from the photoreceptor by the fur brush (24) and the blade (25). Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrostatic detection fine particles), a positive image can be obtained, and if it is developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to such a developing unit.
In addition, a known method is used for the charge removing means.

FIG. 2 is a schematic view of another electrophotographic apparatus according to the present invention. The photoreceptor (31) is the photoreceptor of the present invention, is driven by drive rollers (32a) and (32b), is charged by a charger (33), is exposed by a light source (34), is exposed to light, and is developed (not shown). Transfer using the charger (35), exposure before cleaning with the light source (36), cleaning with the brush (37), and static elimination with the light source (38) are repeatedly performed. In FIG. 3, the photoconductor (21) (of course, the support is translucent in this case) is irradiated with light for pre-cleaning exposure from the support.

The electrophotographic method and the electrophotographic apparatus illustrated above are examples of the embodiment of the present invention, and other embodiments are also possible. For example, in FIG. 2, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or the image exposure and the erasing light irradiation may be performed from the support side. The light irradiation step includes image exposure, pre-cleaning exposure, and charge removal exposure. However, in addition to the above, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation steps are provided, and the photoreceptor is exposed to light. Irradiation can also be performed.

The image forming means performed in this manner may be fixed and incorporated in a copying machine, a facsimile, or a printer, or may be incorporated in these apparatuses in the form of a process cartridge. The process cartridge is a device including a photoreceptor, a charging unit, an exposing unit, a developing unit, a transferring unit, a cleaning unit, and a discharging unit. There are many types of process cartridges, etc.
Here, one example is shown in FIG. This process cartridge comprises the electrophotographic photosensitive member (26) of the present invention, a charging charger (27), a cleaning brush (28), an image exposure section (29), and a developing roller (30).

[0073]

EXAMPLES (Copolymerization Example 1) No. 11 triarylamine acrylic monomer 10 g, one-terminal acrylic-modified polysiloxane (BX16-192 manufactured by Dow Toray) 5
g, 35 g of toluene and 0.1 g of azobisdimethylvaleronitrile were placed in a 100-ml four-necked flask, reacted at 65 ° C. for 7 hours in a nitrogen stream, cooled after the reaction, diluted with toluene, and precipitated with 1 L methanol. As a result of GPC, the molecular weight was Mw 43,000 in terms of polystyrene. Similarly, the polymerization shown in the following table was carried out.

[0074]

[Table 1] MMA: methyl methacrylate, EMA: ethyl methacrylate, MA: methacrylic acid, HEMA: 2 human peroxyethyl methacrylate

Example 1 A coating liquid for an undercoat layer, a coating liquid for a charge generation layer, and a coating liquid for a charge transport layer were sequentially coated and dried on a 30 mm-diameter aluminum cylinder by drying. A 0.5 μm undercoat layer, a 0.2 μm charge generation layer and a 22 μm charge transport layer were formed, and a filler layer was further provided to obtain an electrophotographic photoreceptor of the present invention.

[Coating solution for undercoat layer] Alkyd resin 6 parts (Beccosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals) Melamine resin 4 parts (Super Beckamine G-821-60, Dainippon Ink and Chemicals, Inc.) Manufactured) Titanium oxide 40 parts (CREL manufactured by Ishihara Sangyo) Methyl ethyl ketone 200 parts

[Coating Liquid for Charge Generating Layer] Oxo titanium phthalocyanine pigment 2 parts Polyvinyl butyral (UCC: XYHL) 0.2 parts Tetrahydrofuran 50 parts

[Coating Liquid for Charge Transporting Layer] 10 parts of polycarbonate resin (Z Polyka, Mv50,000 manufactured by Teijin Chemicals Limited)

[0079]

Embedded image 10 parts 1% silicone oil (KF50 Shin-Etsu Chemical Co., Ltd.) methylene chloride solution 1 part Methylene chloride 100 parts The following filler coating solution was ring-coated on the above photosensitive layer, and dried to form a 4 μm filler layer.

[Filler Layer Coating Solution] Compound of Polymerization Example 1 5 parts Titanium oxide (CR97 manufactured by Ishihara Sangyo Co., Ltd.) 2 parts Methylene chloride 40 parts The undercoat layer, the charge generation layer, and the charge transport layer were formed in the same manner as in Example 1. In addition, the inorganic filler layer shown in Table 2 below was provided in the same manner as in Example 1.

Examples 1 to 12 are shown in Table 2 below.

[0082]

[Table 2]

Example 13 In the same manner as in Example 1, an undercoat layer and a charge generation layer were provided, and the following polymer transport layer was provided.

[0084]

Embedded image 3 parts Methylene chloride 20 parts 1% silicone oil methylene chloride solution 0.1 part The filler layer of Example 9 in Table 2 was provided on the charge transport layer.

(Comparative Example 1) A photoreceptor of Example 1 without a filler layer was obtained.

Comparative Example 2 A photoreceptor containing no filler of Example 1 was obtained.

The photosensitive members of Examples 1 to 13 and Comparative Examples 1 and 2 were subjected to roller charging, laser exposure at 780 nm,
Attached to a Ricoh Imagio MF200 equipped with a component type development and a urethane rubber blade counter cleaning system, a dark part potential (VD) of 800 V and a light part potential (VL) of 80
A running test of 10,000 sheets was performed at a setting of V. Table 3
Medium VD and VL indicate the amount of change (V). Initial sensitivity is 80
The half-exposure dose sensitivity from 0V. The amount of abrasion was measured by an eddy current film thickness meter manufactured by Fisher. The coefficient of friction was measured by the Euler belt method.

[0088]

[Table 3]

In Examples 1 to 13, the initial friction coefficient was lowered, but even after copying 10,000 sheets, the friction coefficient was increased, but it was kept low, and abnormal noise in the cleaning section and poor cleaning were not confirmed. In Comparative Example 1, an irregular noise occasionally occurred and cleaning was poor due to sticking of the cleaning blade, resulting in generation of a bumpy background stain. Comparative Example 2
The wear amount is large and the durability is low. Although it was a copy test of 10,000 sheets, in the examples, clear images could be obtained at the beginning and after the endurance. As described above, the filler layer of the acrylic compound having a triarylamine structure and the polysiloxane acrylic compound copolymer can maintain a high image quality by maintaining a low friction coefficient and improving abrasion resistance, and can improve the durability of the photoreceptor. did it.

[0090]

As is apparent from the detailed and concrete description, according to the present invention, in an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, at least one electrophotographic photoreceptor is provided from the surface farthest from the conductive substrate. The layer contains a copolymer of a charge-transporting vinyl compound and a terminal acrylic or methacryl-modified polysiloxane and a filler, so that high image quality can be maintained by improving abrasion resistance, and there is no cleaning failure even when used repeatedly. This is an extremely excellent effect that a high-sensitivity, high-durability electrophotographic photosensitive member and an electrophotographic apparatus using the same can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of an electrophotographic apparatus and a process cartridge for the electrophotographic apparatus of the present invention.

FIG. 2 is a schematic view of another electrophotographic apparatus of the present invention.

FIG. 3 is another view showing the process cartridge of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 photoconductor 12 static elimination lamp 13 charging charger 14 eraser 15 image exposure unit 16 developing unit 17 pre-transfer charger 18 registration roller 19 transfer paper 20 transfer charger 21 separation charger 22 separation claw 23 cleaning charger 24 fur brush 26 photoconductor 27 charging charger 28 Cleaning brush 29 Image exposure unit 30 Developing roller 31 Photoreceptor 32a Driving roller 32b Driving roller 33 Charging charger 34 Image exposure source 35 Transfer charger 36 Exposure before cleaning 37 Cleaning brush 38 Static elimination light source

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 5/05 103 G03G 5/05 103A 103B 104 104A 104B 5/07 103 5/07 103

Claims (13)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, wherein at least one layer from the surface farthest from the conductive substrate contains a charge-transporting vinyl polymer and a filler. . 2. An electrophotographic photosensitive member having a photosensitive layer on a conductive substrate, wherein at least one layer from the surface farthest from the conductive substrate has acrylic or methacrylic compound having a triarylamine structure and one terminal acrylic. Or an electrophotographic photosensitive member containing a copolymer of a methacryl-modified polysiloxane compound and an inorganic filler or an organic filler. 3. The triarylamine structure of the copolymer
Acrylic or methacrylic compounds having the general formula
(1) or a compound represented by the general formula (2)
Or methacrylic polysiloxane compounds have the general formula
Claims characterized by being a copolymer represented by (3).
Item 2. The electrophotographic photosensitive member according to Item 1. Embedded imageEmbedded imageEmbedded image(Where R¹Is hydrogen, methyl, Ar¹, Ar^TwoIs Arile
And represents an Ar group^Three, Ar ^FourMay be the same or different
Represents an unsubstituted aryl group. R^TwoIs hydrogen, methyl,
R^Three, R^Four, R^Five, R⁶, R⁷Represents an alkyl group or a phenyl group
1 is an integer up to 0 or 6, j is 0 or 1, m
Represents 5-1000. ) 4. The electrophotographic photoreceptor according to claim 2, wherein the photoreceptor is a copolymer obtained by copolymerizing one or more monomers represented by the following general formula (4). Embedded image (Z is a substituted or unsubstituted aryl group, -COOR
^{In 8} , R ⁸ represents hydrogen, a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group, a cyclic ether group, or a hydroxy group-substituted alkyl group. ) 5. An electrophotographic photosensitive member having a photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate directly or via an undercoat layer, wherein the charge transport layer comprises at least a charge transport substance and a filler. And a filler in the charge transport layer has a higher content on the surface farthest away from the conductive substrate. 6. The electron according to claim 4, wherein the charge transport layer is formed by laminating a layer composed of a low molecular charge transport substance and a binder resin and a layer composed of a charge transport binder resin and a filler. Photoreceptor. 7. The electrophotographic photoreceptor according to claim 1, wherein the inorganic filler contained in the charge transport layer is titanium oxide. 8. The electrophotographic photosensitive member according to claim 1, wherein the inorganic filler contained in the charge transport layer is silica. 9. The electrophotographic photosensitive member according to claim 1, wherein the inorganic filler contained in the charge transport layer is alumina. 10. The method according to claim 1, wherein the organic filler contained in the charge transport layer is a crosslinked polymer compound of a polyfunctional vinyl group or a polyfunctional crosslinked polycondensation compound. Electrophotographic photoreceptor. 11. The electrophotographic photosensitive member according to claim 5, wherein the charge transport layer is formed by a multiple coating method. 12. An electrophotographic apparatus having an electrophotographic photoreceptor, a charging unit, an image exposing unit, a developing unit, and a transfer unit, wherein the electrophotographic photoreceptor is an electrophotographic photoreceptor according to any one of claims 1 to 11. An electrophotographic apparatus, which is a photographic photoreceptor. 13. A process cartridge for an electrophotographic apparatus integrally supporting at least one unit selected from the group consisting of an electrophotographic photosensitive member, a charging unit, a developing unit and a cleaning unit, wherein the electrophotographic photosensitive member is A process cartridge comprising the electrophotographic photosensitive member according to claim 1, wherein the process cartridge is detachable from an electrophotographic apparatus main body.