JP2001235889A - Electrophotographic photoreceptor, electrophotographic device with the same, process cartridge and method for producing the electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high surface strength, good surface smoothness and lubricity and capable of forming a ghost- free image, an electrophotographic device with the photoreceptor and a process cartridge. SOLUTION: The electrophotographic photoreceptor has a surface layer containing metal oxide particles surface-treated with a surface treating agent, an alcohol-soluble bonding resin and an alcohol-soluble electric charge transferring material.

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 having a surface layer, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and a method of manufacturing the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Electrophotographic photosensitive members used in electrophotographic copying machines and printers are required to have sensitivity to visible light and near-infrared light, which is a semiconductor laser beam, and in recent years the sensitivity has become increasingly high. There is a need to simultaneously achieve reliability and low cost. At present, the most influential photoconductors that meet these demands are organic photoconductors. Above all, a function-separated type organic photoconductor in which a charge generation layer that generates charges by exposure and a charge transport layer that transports generated charges are stacked, has sensitivity, chargeability, their stability over time, and electrophotography. Excellent in characteristics and the like. Various types of such laminated organic photoreceptors have been proposed and put to practical use, but most of them have a charge transport layer in which a low molecular charge transport material is dispersed in a binder resin as an outermost layer. Things.

However, a charge transport layer in which a low-molecular charge transport material is dispersed is easily worn by mechanical stress caused by a cleaning blade, and the life of an electrophotographic photosensitive member having such a charge transport layer is short.

[0004] In recent years, there has been growing interest in the effect of ozone generated from an electrophotographic printer in an office environment on health, and contact charging, which generates a significantly smaller amount of ozone than a conventional non-contact corotron charging system. The method is receiving attention. However, in this contact charging method, the charging roll or charged film is brought into contact with the electrophotographic photosensitive member to charge the electrophotographic photosensitive member, and since the discharge area is close to the photosensitive member surface, the discharge applied to the photosensitive member is Stress is stronger than that of non-contact type corotron charging system. For this reason, the discharge products easily adhere to the surface of the photoconductor,
Since the wear of the photoconductor increases, the chargeability decreases due to abrasion, sensitivity changes, and image quality decreases such as fogging and black lines. Often shorter.

[0005] Under such circumstances, it is required to increase the surface strength of the electrophotographic photosensitive member and extend its useful life. Further, due to repeated use over a long period of time, there arises a problem that reaction products such as ozone and NOx generated during charging and toner used during development remain on the surface of the electrophotographic photosensitive member without being removed in a cleaning step.

[0006] In order to solve these problems, a method of increasing the surface hardness of the surface layer of the photoreceptor to prevent abrasion and scratching, and increasing the lubricity of the surface layer of the photoreceptor, thereby suppressing abrasion. In addition, various methods have been proposed for easily removing attached substances such as toner and reaction products from the surface layer to prevent the surface from being deteriorated.

As a method of strengthening the surface layer of the photoreceptor,
A method of protecting a photosensitive layer with a surface layer in which conductive fine particles having an average particle diameter smaller than the wavelength of light used, for example, metal oxide fine particles whose surface has been treated with a surface treating agent are dispersed in a binder resin. It has been proposed (for example, Japanese Patent Application Laid-Open
No. 0846).

[0008] However, an image formed by using such an electrophotographic photosensitive member sometimes has a ghost.

Further, as a binder resin for such a surface layer, a thermoplastic resin is not suitable because of insufficient strength. On the other hand, when a thermosetting resin is used as a binder resin for the surface layer, a solvent that easily dissolves the resin, such as aromatic hydrocarbons, acetates, and halogenated carbides, must be used.
Since these solvents also dissolve the resin of the photosensitive layer, as a method of applying the surface layer, a layer having a uniform thickness can be formed in a short time as in the dip coating method, but at that time, the photosensitive layer is dissolved. The method cannot be adopted. Further, since the thermosetting resin is cured even in the coating liquid, the pot life of the coating liquid containing the thermosetting resin is short. Therefore, the application method of the surface layer has been limited to a spray coating method which hardly dissolves the photosensitive layer and has little influence on the pot life.

As a method for increasing the lubricity of the surface layer of the photoreceptor, a method of dispersing a fluororesin powder in the surface layer has been proposed (for example, Japanese Patent Application Laid-Open No. Sho 63).
-221355). According to this method, the surface energy and friction coefficient of the surface layer are reduced by the fluororesin powder, toner and the like are easily removed, and durability against abrasion and scratches is improved.

However, since the fluororesin powder is hard to disperse in the binder resin and easily aggregates, it is difficult to form a smooth and uniform surface layer.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having high surface strength, good surface smoothness, and lubricity and capable of forming a ghost-free image. It is another object of the present invention to provide an electrophotographic apparatus and a process cartridge having such an electrophotographic photosensitive member. Another object of the present invention is to provide a method for producing an electrophotographic photoreceptor in which a surface layer can be formed by a dip coating method.

[0013]

SUMMARY OF THE INVENTION The present invention provides an electrophotographic photoreceptor having a surface layer containing metal oxide particles whose surfaces have been treated with a surface treating agent, an alcohol-soluble binder resin and an alcohol-soluble charge transport material. I will provide a.

Further, the present invention provides an electrophotographic apparatus and a process cartridge having the electrophotographic photosensitive member.

The present invention further provides a photosensitive layer provided on a substrate, comprising: a metal oxide particle having a surface treated with a surface treating agent;
Provided is a method for producing an electrophotographic photoreceptor, in which a surface layer is formed by immersing an alcohol-soluble binder resin and an alcohol-soluble charge transport material in a dispersion obtained by dissolving and dispersing the same in alcohol.

[0016]

Embodiments of the present invention will be described below in detail.

The electrophotographic photoreceptor of the present invention has a conductive substrate, a photosensitive layer, and a surface layer in this order. An undercoat layer may be provided between the conductive substrate and the photosensitive layer. The photosensitive layer may be a single layer having both a function of generating charge and a function of transporting charge, or a laminate including a charge generation layer and a charge transport layer. Further, the order of the charge generation layer and the charge transport layer is arbitrary. Further, the electrophotographic photoreceptor of the present invention may include an intermediate layer.

Known conductive substrates can be used. For example, aluminum, nickel, chromium, metals such as stainless steel, aluminum, titanium,
Examples include a plastic film provided with a thin film of nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, ITO, and the like, and a paper and plastic film coated or impregnated with a conductivity imparting agent. The shape of these conductive substrates is generally a drum shape or a sheet shape, but is not limited thereto. Various processes can be performed on the surface of the conductive substrate within a range that does not affect the image quality. For example, oxidation treatment, chemical treatment, coloring treatment, graining, irregular reflection treatment such as liquid honing, and the like can be performed.

The undercoat layer contains a binder. Examples of the binder used in the undercoat layer include acetal resins such as polyvinyl butyral, polyvinyl alcohol resins, casein, and the like.
Polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol- Examples include polymer compounds such as formaldehyde resins and melamine resins, and organometallic compounds containing zirconium, titanium, aluminum, manganese, silicon, and the like. Among the organometallic compounds, those containing titanium, aluminum and silicon are preferable.

Examples of the organometallic compound containing titanium include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene Glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanol aminate, polyhydroxytitanium stearate and the like can be mentioned.

Examples of the organometallic compound containing aluminum include aluminum isopropylate, monobutoxyaluminum isopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

Examples of silicon-containing organometallic compounds include, for example, vinylmethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy)
Silane, vinyltriacetoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycid Xypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,
γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β- (Hydroxyethyl) -γ-aminopropyltriethoxysilane, N
-Phenyl-3-aminopropyltrimethoxysilane,
γ-chloropropyltrimethoxysilane and the like. Among these, silane compounds particularly preferably used are vinyltriethoxysilane, vinyltris (β-methoxyethoxysilane), γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropylmethoxysilane, β- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane,
Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, γ-methylcaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane.

The organometallic compound can be used alone, as a mixture of a plurality of compounds, as a polycondensate of a plurality of compounds, or together with the polymer compound used for the undercoat layer. In addition, a polymer compound can be used alone or in combination.

In the undercoat layer, various organic or inorganic fine powders can be mixed for the purpose of preventing the occurrence of interference fringes and improving the electrical characteristics. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, and lithopone; inorganic pigments such as alumina, calcium carbonate, and barium sulfate; Teflon resin particles, benzoguanamine resin particles, and styrene resin particles And silicon single crystal fine powder are effective. Particle size of fine powder is 0.01μm ~ 2μ
m is preferable. If the particle size is larger than 2 μm, the undercoat layer will have severe irregularities, the electrical characteristics will vary depending on the location, and image quality defects will easily occur. In addition, 0.01 μm
If it is smaller, a sufficient light scattering effect cannot be obtained. When the fine powder is added, the amount is preferably 10 to 80% by weight based on the solid content of the undercoat layer, and 30 to 80% by weight.
More preferably, it is 70% by weight.

When the thickness of the undercoat layer is increased, the surface of the photoreceptor can be smoothed even if the conductive substrate has irregularities, so that image quality defects generally tend to be reduced. Be faster. Therefore, the thickness of the undercoat layer is 0.1
It is desirably in the range of ５5 μm.

The charge generation layer contains a binder resin and a charge generation material dispersed in the binder resin. Examples of the charge generation material include metal-free phthalocyanine, titanyl phthalocyanine, copper phthalocyanine, tin phthalocyanine, various phthalocyanine pigments such as gallium phthalocyanine, squarium, anthantrone, perylene, azo, anthraquinone, pyrene, pyrylium salts, Various organic pigments and dyes such as thiapyrylium salts are used. Organic pigments generally have several types of crystal forms, and in particular, phthalocyanine pigments are known to have various crystal types, including α, β, etc. A crystal type may be used.

Examples of the binder resin used for the charge generation layer include polycarbonate resins such as bisphenol A type and bisphenol Z type, polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polystyrene resins, polyvinyl acetate resins, and styrene. −
Butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinyl carbazole, and the like. These binder resins can be used alone or in combination of two or more.

A silane coupling agent or an organometallic alkoxide can be added to the charge generation layer for various purposes such as preventing aggregation of the charge generation material, improving dispersibility, and improving electrical characteristics.

The compounding ratio (weight ratio) of the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10. Also,
The thickness of the charge generation layer is generally from 0.01 to 5 μm, preferably from 0.05 to 2.0 μm.

The charge transport layer contains a charge transport material and, if necessary, a binder resin. As the charge transport material, 2,5
-Bis (p-diethylaminophenyl) -1,3,4-
Oxadiazole derivatives such as oxadiazole, 1,
3,5-triphenyl-pyrazoline, 1-pyridyl-3
Pyrazoline derivatives such as-(p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline;
Aromatic tertiary amino compounds such as triphenylamine, tri (p-methylphenyl) amyl-4-amine and dibenzylaniline, N, N'-diphenyl-N, N'-bis (3-methylphenyl)- [1,1'-biphenyl]
Aromatic tertiary diamino compounds such as 4,4'-diamine,
3- (4'-dimethylaminophenyl) -5,6-di-
1,2,4-triazine derivatives such as (4'-methoxyphenyl) -1,2,4-triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 2-phenyl-4-styryl- Quinazoline derivatives such as quinazoline, 6-hydroxy-2,
Benzofuran derivatives such as 3-di (p-methoxyphenyl) benzofuran, p- (2,2-diphenylvinyl)-
Hole transport substances such as α-stilbene derivatives such as N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof; quinone compounds such as chloranyl and bromoanthraquinone , Tetraalkyldimethane compounds, 2,4,7-trinitrofluorenone,
Electron transport substances such as fluorenone compounds such as 2,4,5,7-tetranitro-9-fluorenone; xanthone compounds; thiophene compounds; and polymers having a group consisting of the above compounds in the main chain or side chain. Can be These charge transport materials can be used alone or in combination of two or more.

Examples of the binder resin used for the charge transport layer include acrylic resins, polyarylates, polyester resins, polycarbonate resins such as bisphenol A type and bisphenol Z type, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene. Examples thereof include copolymers, insulating resins such as polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, and chlorine rubber, and organic photoconductive polymers such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene.

The mixing ratio of the charge transport material to the binder resin is preferably from 10: 1 to 1: 5. The thickness of the charge transport layer is generally 5 to 50 μm, preferably 10 to 40 μm.
m.

When the photosensitive layer is a single layer, a material in which a charge generation material or a charge transport material is dispersed in a binder resin can be used.

For the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, light and heat generated in the electrophotographic apparatus, additives such as antioxidants, light stabilizers and heat stabilizers are added to the photosensitive layer. Can be added. Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like. Examples of the light stabilizer include derivatives such as benzophenone, benzoazole, dithiocarbamate, and tetramethylpipen.

The surface layer contains metal oxide particles the surface of which has been treated with a surface treating agent, a binder resin, and a charge transport material. This surface layer is preferably colorless and transparent.

The content of the metal oxide particles is preferably 5 to 90% by weight, and more preferably 30 to 8% by weight based on the total weight of the surface layer.
More preferably, it is 0% by weight. Content is 5% by weight
If it is less than 90%, it is difficult to obtain sufficient conductivity, and if it exceeds 90% by weight, it may be difficult to obtain sufficient mechanical strength.

The average primary particle diameter of the metal oxide particles is 0.0
It is preferably from 1 to 0.3 μm, and from 0.05 to 0.
More preferably, it is 1 μm. If the average primary particle size is less than 0.01 μm, the particles are likely to aggregate, which makes it difficult to disperse. Defects may occur.

The metal oxide used in the present invention includes tin oxide, antimony oxide, zinc oxide, titanium oxide, bismuth oxide, indium oxide, tantalum oxide, tin oxide doped with tantalum, tin oxide doped with antimony, Indium-doped tin oxide may be used. These metal oxides may be used alone or in combination of two or more.

Examples of the surface treatment agent used for lowering the surface energy of the metal oxide include a silane coupling agent, a silicone oil, a siloxane compound, and a surfactant. These preferably contain a fluorine atom.

Examples of the fluorine-containing silane coupling agent include, for example, CF ₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ and C ₄
F ₉ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , C ₆ F ₁₃ CH ₂ CH ₂ S
i (OCH ₃ ) ₃ , C ₈ F ₁₇ CH ₂ CH ₂ Si (OC
_{H 3) 3, C 8 F} 17 CH 2 CH 2 SiMe (OCH 3) 2, C 8
F ₁₇ CH ₂ CH ₂ Si (OCH ₂ CH ₂ OCH ₃ ) ₃ , C ₁₀ F
₂₁ Si (OCH ₃ ) ₃ , C ₁₀ F ₂₁ CH ₂ CH ₂ Si (OCH
₃ ) ₃ .

Examples of the fluorine-modified silicone oil include, for example, compounds represented by the following general formula (I).

[0042]

Embedded image

R in the formula is -CH ₂ CH ₂ CF ₃ , -CH ₂ C
_{H 2 C 4 F 9, -CH} 2 CH 2 C 6 F 13, -CH 2 CH 2 C 8 F
Represents a fluorinated alkyl group such as ₁₇ , and m and n are positive integers.

Examples of the fluorine-based surfactant include, for example, compounds represented by the following general formulas (II) to (IV). _{X-SO 2 NRCH 2 CH 2} O (CH 2 CH 2 O) nH (II) X-RO (CH 2 CH 2 O) nH (III)

[0045]

Embedded image

In the formula, R is a single bond, an alkyl group, and X is-
CF_Three, -C_FourF₉, -C₆F₁₃, -C ₈F₁₇Fluoride such as
Represents a alkyl group, and n represents a positive integer.

In order to treat the metal oxide particles with the above-mentioned surface treating agent, first, the metal oxide particles and the surface treating agent are dispersed in an appropriate solvent, and the surface treating agent is attached to the surface of the metal oxide particles. Let it. A catalyst may be added to this dispersion to promote the reaction. As a method for dispersing the metal oxide particles in a solvent, a method such as a roll mill, a ball mill, a vibration mill, an attritor, a sand mill, and an ultrasonic dispersion can be used. Next, after removing the solvent from the dispersion,
The surface treatment agent is fixed to the surface of the metal oxide particles by heat treatment. If the obtained surface-treated metal oxide is agglomerated, pulverization may be performed as necessary.

The amount of the surface treating agent depends on the particle size of the metal oxide particles, but is preferably 1 to 70% by weight, more preferably 5 to 50% by weight, based on the amount of the metal oxide. More preferred.

The binder resin of the surface layer needs to be soluble in an alcohol solvent, and examples of such a binder resin include a polyamide resin and a resin having a polyvinyl alcohol component. As the polyamide resin, copolymerized nylon or methoxymethylated nylon soluble in an alcohol solvent is used. Copolymer nylon is nylon 6, nylon 66, nylon 610, nylon 1.
Polymerized by various combinations of 2 and the like, and those obtained by methoxymethylation thereof can also be used. Also,
Examples of the resin having a polyvinyl alcohol component include polyvinyl alcohol obtained by saponifying polyvinyl acetate (copolymer resin of polyvinyl alcohol and polyvinyl acetate), and polyvinyl acetal obtained by acetalizing it with an aliphatic aldehyde (polyvinyl alcohol-polyvinyl acetate-).
For example, a terpolymer resin of polyvinyl acetal) is used. The polyvinyl acetal includes polyvinyl formal, polyvinyl butyral, and the like.

The charge transporting material used for the surface layer needs to be soluble in an alcohol solvent. Examples of such a charge transporting material include a charge transporting material represented by the following general formula (V).

[0051]

Embedded image

In the formula, l is an integer of 0 to 4, m is an integer of 1 to 4, and T is any one of linear or branched alkylene, ester bond, ether bond and the like having 1 to 10 carbon atoms. U represents a carboxylic acid or a hydroxyl group. A
Represents a structure represented by the following general formula (VI) or (VII).

[0053]

Embedded image

R ₆₁ and R ₆₂ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom; R _{63 to} R ₆₆ may be the same or different; , An alkoxy group, a halogen atom or a substituted amino group. K to n each represent an integer of 1 or 2.

[0055]

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R _{71 to} R ₇₂ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and m and n each represent an integer of 1 or 2. R ₇₃ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

Tables 1 to 3 show specific examples of the benzidine compound represented by the general formula (VI).

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

Tables 4 and 5 show specific examples of the triarylamine-based compound represented by the general formula (VII).

[0062]

[Table 4]

[0063]

[Table 5]

In addition to the compound represented by the above general formula (I), the following general formula (VII) can be used as a charge transporting material which can be used with the polymer of the present invention to obtain good properties.
Compounds represented by I) to (XII) are exemplified.

[0065]

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In the formula, X ₈ represents an optionally substituted 2
R _{81 to} R ₈₆ each represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent,
Represents an alkoxy group or a substituted amino group, which may be the same or different; Also, R _{87 to} R ₈₁₂
Represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent, which are the same or different from each other. R ₈₈ and R ₈₉ and R ₈₁₁ and R ₈₁₂ may be condensed to form a carbocyclic or heterocyclic group.

[0067]

Embedded image

In the formula, X ₉ represents —CH ₂ CH ₂ — or —CH
ＣＨCH-, R _{91 to} R ₉₃ represent an alkyl group, an aralkyl group, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent, and R _{94 to} R ₉₅ Hydrogen atom,
Represents an alkyl group, an alkoxy group or a halogen atom.

[0069]

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In the formula, R _{101 to} R ₁₀₂ represent an alkyl group,
R ₁₀₃ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ₁₀₄ to R ₁₀₅ represents a hydrogen atom, an alkyl group, an aryl group which may have an aralkyl group or substituent.

[0071]

Embedded image

In the formula, R _{111 to} R ₁₁₈ are each a hydrogen atom,
Represents an alkyl group, an alkoxy group or a halogen atom,
These may be the same or different from each other.

[0073]

Embedded image

In the formula, R _{121 to} R ₁₂₄ are each a hydrogen atom,
Represents an alkyl group, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent.

The content of the charge transporting material is preferably from 1 to 90% by weight, more preferably from 5 to 60% by weight, based on the total weight of the surface layer. If the content is less than 1% by weight, residual potential tends to accumulate, and if it exceeds 90% by weight, unreacted hydroxyl groups increase, so that electrical characteristics depend on the environment. In addition, it is easy to adhere.

It is preferable that at least one of the binder resin and the charge transporting material used for the surface layer is crosslinked.
Examples of the crosslinking agent include melamine derivatives and polyisocyanates.

The melamine derivative is represented by the following general formula (XI)
Compounds represented by II) are preferred.

[0078]

Embedded image

In the formula, R ¹ represents a methyl group, an ethyl group or a butyl group, and R ² represents a hydrogen, acetonyl group or a hydroxymethyl group.

The isocyanate is preferably a blocked isocyanate. This blocked isocyanate is a stable compound at room temperature obtained by reacting a compound having a certain type of active hydrogen (blocking agent) with a polyisocyanate compound. When the compound is heated under certain conditions, the blocking agent is dissociated. Thus, the original active isocyanate groups are regenerated. As a polyisocyanate compound serving as a base of such a blocked isocyanate,
Tolylene diisocyanate, diphenylmethane-4,
4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, and the like. Examples of the blocking agent to be reacted with the isocyanate include lactams such as caprolactam, oximes such as methyl ethyl ketoxime and acetoxime, and β-diketones such as diethyl malonate and ethyl acetoacetate.

In the present invention, a leveling agent can be added to the surface layer in order to smooth the surface.

The thickness of the surface layer of the present invention is 0.5 to 50 μm.
And more preferably 2 to 10 μm. If the film thickness is less than 0.5 μm, the life cannot be improved, and if it exceeds 50 μm, the sensitivity tends to decrease and the residual potential tends to increase.

The electrophotographic photosensitive member of the present invention can be manufactured as follows.

The coating liquid is prepared by dissolving and dispersing the components of the undercoat layer (if any), the charge generation layer and the charge transport layer in a solvent. As a dispersion method, a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill,
A method using a colloid mill, a paint shaker, or the like can be used. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, and chlorobenzene, ketones such as acetone and 2-butanone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride, tetrahydrofuran, and dioxane. Or a cyclic or linear ether such as ethylene glycol and diethyl ether, or a mixed solvent thereof. Immerse the conductive substrate that has undergone the necessary treatment in the coating solution,
The step of drying the coating layer is repeated for each layer. Next, the components of the surface layer are dissolved and dispersed in alcohol to prepare a coating solution for the surface layer. A conductive substrate on which a photosensitive layer is formed is immersed in this coating solution, and the coated layer is dried to obtain the electrophotographic photosensitive member of the present invention. As alcohol solvents,
Methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-
Butanol, tert-butanol and the like.

The electrophotographic photoreceptor of the present invention can be used in electrophotographic apparatuses such as light lens type copiers, laser beam printers emitting near infrared light or visible light, digital copiers, LED printers, and laser facsimile machines. it can. Also, this electrophotographic photoreceptor is a one-component type,
It can be used in combination with a two-component regular developer or a reversal developer.

FIG. 1 is a schematic view of a non-contact charging type electrophotographic apparatus 20 provided with the electrophotographic photosensitive member 7 of the present invention. Around the electrophotographic photosensitive member 7, a charging member 8 of a corona discharge type to which a voltage is supplied from a power supply 9, an image input device 10 for exposing the electrophotographic photosensitive member 7, and a latent image on the electrophotographic photosensitive member 7. Developing device 11 for attaching toner, transfer device 1 for transferring toner image on electrophotographic photoreceptor 7 to a recording medium such as paper
2. A cleaning device 13 for removing toner remaining on the electrophotographic photosensitive member 7 and a static eliminator 14 for removing charges on the electrophotographic photosensitive member 7 are provided in this order. Further, a fixing device 15 for fixing the toner image on the recording medium is provided downstream of the electrophotographic photosensitive member on the conveyance path of the recording medium. Note that the cleaning device 13 may be omitted.

FIG. 2 is a schematic view of a contact charging type electrophotographic apparatus 22 provided with the electrophotographic photosensitive member 7 of the present invention. In addition,
The same components as those of the electrophotographic apparatus 20 of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The electrophotographic apparatus 22 is different from the electrophotographic photosensitive member 20 shown in FIG.
A charging member 24 that contacts the electrophotographic photosensitive member 7 is provided. In the electrophotographic device 22, the cleaning device 13,
The static eliminator 14 can be omitted.

FIG. 3 is a schematic view of a process cartridge 17 provided with the electrophotographic photosensitive member 7 of the present invention. Note that the same components as those of the electrophotographic apparatus 20 of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the process cartridge 17, the electrophotographic photosensitive member 7, the charging member 8,
Developing device 11, cleaning device 13, and static eliminator 14
A fixing rail 16 for fixing the process cartridge 17 to an electrophotographic apparatus is fixed outside the process cartridge 17.

[0089]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. (Example 1) 30 parts by weight of acetylacetone zirconium butyrate as a zirconium-containing organic metal compound in 170 parts by weight of n-butyl alcohol in which 4 parts by weight of a polyvinyl butyral resin (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) was dissolved, and As a silicon-containing organometallic compound, 3 parts by weight of γ-aminopropyltrimethoxysilane was added and stirred to obtain a coating liquid for forming an undercoat layer. This coating solution is 84 m in diameter roughened by a honing process.
m, and air-dried at room temperature for 5 minutes. Then, the temperature of the substrate was raised to 50 ° C. for 10 minutes.
It was placed in a thermo-hygrostat at 0 ° C. and 85% RH (dew point: 47 ° C.), and was subjected to a humidification and curing acceleration treatment for 20 minutes. Then, it was dried in a hot air dryer at 170 ° C. for 10 minutes.

A mixture of 15 parts by weight of gallium chloride phthalocyanine as a charge generating material, 10 parts by weight of a vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide Co., Ltd.) and 300 parts by weight of n-butyl alcohol was sand-milled. For 4 hours. The resulting dispersion is dip-coated on the undercoat layer and dried to form a film having a thickness of 0.1 μm.
A 2 μm charge generation layer was formed.

Next, N, N'-diphenyl-N, N'-
Bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (4 parts) and bisphenol Z polycarbonate resin (molecular weight 40,000) (6 parts by weight) are added to 80 parts by weight of chlorobenzene and dissolved. did. The obtained solution was dip-coated on the charge generation layer and dried to form a 13 μm-thick charge transport layer.

Next, 100 parts by weight of tin oxide particles (S-1, manufactured by Mitsubishi Materials Corporation), which are conductive fine particles, were mixed with heptadecafluorodecyltrimethoxysilane (TSL823).
3, 20 parts by weight of Toshiba Silicone Co., Ltd.) and 300 parts of methanol were stirred in a ball mill for 24 hours, the solution was filtered, the tin oxide on the filter was washed with methanol, and then dried at 150 ° C. for 2 hours to oxidize. Surface treatment of tin particles was performed. 12 parts by weight of the surface-treated tin oxide particles, 4 parts by weight of the charge transporting material represented by the following structural formula (XIV), and 11 parts by weight of a block-type isocyanate (Sumidur BL3175, manufactured by Sumitomo Bayer Urethane Co.) were mixed with polyvinyl butyral. 8 parts by weight of a resin (ESLEK BH-S, manufactured by Sekisui Chemical Co., Ltd.) was mixed with a solution of 200 parts of n-butyl alcohol and dispersed in a sand mill for 12 hours. The charge transport layer was dip-coated on the obtained dispersion and dried and cured at 150 ° C. for 1 hour.
A μm surface layer was formed on the charge transport layer. As described above, since the alcohol which does not dissolve the charge transport layer resin thereunder was used in the surface layer coating solvent, all the layers could be formed by dip coating as described above, and the electrophotographic photoreceptor could be manufactured efficiently. The liquid viscosity of the surface layer coating liquid was stable at room temperature (20 to 25 ° C.) without any significant change even after one month since a block type isocyanate curing agent was used.

[0093]

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The electrophotographic photosensitive member obtained as described above was charged by a scorotron charger of (A) a grid application voltage of -650 V under an environment of 20 ° C. and 50% RH.
(B) After 0.5 seconds, irradiate 9.0 mJ / m ² light with a 780 nm semiconductor laser to discharge the irradiated portion. (C) After 3 seconds, emit 50 mJ / m ² red LED light. The potential of the surface of the electrophotographic photosensitive member was measured in each step of the process of irradiating the entire surface with irradiation. in this case,
The higher the potential V _H of (A), the higher the contrast. The lower the potential V _L of (B), the higher the sensitivity. The lower the potential of (C) V _RP , the lower the residual potential. This indicates that there is little residual image or fog affecting the next image formation.

The above electrophotographic photosensitive member was heated at 28 ° C.
85% RH high temperature and high humidity environment, contact charging type printer (Fuji Xerox Color Laser)
Wind 3310 was modified to measure the potential of the surface of the electrophotographic photoreceptor), and 50,000 sheets of A4
A monochrome image was printed on paper, and the image quality and the wear amount of the photoconductor were evaluated. Table 6 shows the results. (Example 2) Electrons were formed in the same manner as in Example 1 except that the charge transport material represented by the structural formula (XV) was used instead of the charge transport material represented by the structural formula (XIV), which was a material in the surface layer. A photoreceptor was prepared and evaluated. Table 6 shows the results.

[0096]

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(Example 3) Up to the charge transporting layer of the electrophotographic photosensitive member, the same procedure as in Example 1 was carried out. Next, tin oxide particles, which are conductive fine particles (S-1, manufactured by Mitsubishi Materials Corporation)
100 parts by weight of (3,3,3-trifluoropropyl)
The mixture was stirred for 24 hours with a ball mill together with 20 parts by weight of trimethoxysilane (manufactured by Chisso) and 300 parts of methanol, the solution was filtered, the tin oxide particles on the filter were washed with methanol, and then dried at 150 ° C. for 2 hours. The surface treatment of the tin oxide particles was performed. 12 parts by weight of the surface-treated tin oxide particles and the structural formula (XI)
4 parts by weight of the charge transporting material represented by V) were mixed with a polyvinyl butyral resin (Eslek BH-S, manufactured by Sekisui Chemical Co., Ltd.) 8
A part by weight was mixed with a solution of 200 parts of n-butyl alcohol and dispersed in a sand mill for 12 hours. Dip coating was performed using the obtained dispersion, and a dry curing treatment was performed at 150 ° C. for 1 hour to form a surface layer having a thickness of 6 μm on the charge transport layer. The electrophotographic photosensitive member thus obtained was evaluated in the same manner as in Example 1. Table 6 shows the results. (Example 4) Up to the charge transport layer of the electrophotographic photoreceptor, the same procedure as in Example 1 was carried out. Next, 100 parts by weight of tin oxide particles (S-1, manufactured by Mitsubishi Materials Corporation), which are conductive fine particles, were mixed with heptadecafluorodecyltrimethoxysilane (TS).
L8233, manufactured by Toshiba Silicone Co., Ltd.) and 20 parts by weight together with 300 parts of methanol in a ball mill for 24 hours, the solution was filtered, the tin oxide particles on the filter were washed with methanol, and then dried at 150 ° C. for 2 hours. The surface treatment of the tin oxide particles was performed. 12 parts by weight of the surface-treated tin oxide particles and the structural formula (XI)
V) 4 parts by weight of the charge transporting material, 15 parts by weight of a block type isocyanate (Coronate 2507, manufactured by Nippon Polyurethane Industry Co., Ltd.), and 8 parts by weight of a polyamide resin (Platabond MX1602, manufactured by Elfatochem Japan) are n-butyl. It was mixed with a solution dissolved in 200 parts of alcohol and dispersed in a sand mill for 12 hours. Dip coating was performed using the obtained dispersion, and a drying and curing treatment was performed at 150 ° C. for 1 hour to form a surface layer having a thickness of 6 μm on the charge transport layer. The electrophotographic photosensitive member thus obtained was evaluated in the same manner as in Example 1. Table 6 shows the results. (Example 5) tin oxide particles in the surface layer (S-1, manufactured by Mitsubishi Materials Corporation) in place of, Sb ₂ O ₅ is doped tin oxide particles (T-1, manufactured by Mitsubishi Materials Corporation) metal oxide An electrophotographic photosensitive member was prepared by performing a surface treatment of a metal oxide in the same manner as in Example 1 except that the particles were used as material particles, and evaluated.
Table 6 shows the results. Comparative Example 1 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that no surface layer was provided. Table 6 shows the results.

In this electrophotographic photoreceptor, the charge transport layer becomes thinner with printing due to low abrasion resistance.
Since the chargeability was reduced, the electrical characteristics after printing 50,000 sheets could not be evaluated. Comparative Example 2 An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 up to the charge transport layer. Next, 100 parts by weight of tin oxide particles (S-1, manufactured by Mitsubishi Materials Corporation), which are conductive fine particles, were mixed with 20 parts by weight of heptadecafluorodecyltrimethoxysilane (TSL8233, manufactured by Toshiba Silicone Co., Ltd.).
And 300 parts of methanol with a ball mill for 24 hours, and the solution was filtered and washed with methanol.
The surface treatment of the tin oxide particles was performed by drying at 0 ° C. for 2 hours. 12 parts by weight of the surface-treated tin oxide particles, 11 parts by weight of a block type isocyanate (Sumidur BL3175, manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 12 parts by weight of a polyvinyl butyral resin (Eslek BH-S, manufactured by Sekisui Chemical Co., Ltd.) -Butyl alcohol 200
The mixture was mixed with the solution dissolved in the mixture and dispersed by a sand mill for 12 hours. Dip coating was performed using the obtained dispersion, and 150
A dry hardening treatment at 1 ° C. for 1 hour to form a 6 μm thick surface layer,
It was formed on the charge transport layer. The electrophotographic photosensitive member thus obtained was evaluated in the same manner as in Example 1. Table 6 shows the results.

Regarding the image quality, when a character was first printed and then a low density solid image was printed, a negative ghost of the previously printed character was confirmed.

[0100]

[Table 6]

[0101]

According to the present invention, there is provided an electrophotographic photoreceptor having high surface strength, good surface smoothness, and lubricity and capable of forming a ghost-free image, and an electrophotographic photoreceptor having such an electrophotographic photoreceptor. An apparatus and a process cartridge can be provided. Further, the present invention can provide a method for producing an electrophotographic photoreceptor capable of forming a surface layer by a dip coating method.

[Brief description of the drawings]

FIG. 1 is a schematic view of a non-contact charging type electrophotographic apparatus used in the present invention.

FIG. 2 is a schematic view of a contact charging type electrophotographic apparatus used in the present invention.

FIG. 3 is a schematic view of a process cartridge used in the present invention.

DESCRIPTION OF SYMBOLS 7 Electrophotographic photosensitive member 8 Charging member 9 Power supply 10 Image input device 11 Developing device 12 Transfer device 13 Cleaning device 14 Static eliminator 15 Fixing device 16 Mounting rail 17 Cartridge 20 Electrophotographic device 22 Electrophotographic device 24 Charging Parts

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Hozumi 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Kenji 1600 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72 ) Inventor Takahiro Suzuki 1600 Takematsu, Minami Ashigara, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Tetsuya Esumi 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. 1600 address Fuji Xerox Co., Ltd. F-term (reference) 2H068 AA03 AA04 AA05 BA03 BA12 BA58 BB16 BB28 BB29 CA37 EA14 EA16

Claims (4)

[Claims] 1. An electrophotographic photoreceptor comprising a surface layer containing metal oxide particles the surface of which has been treated with a surface treating agent, an alcohol-soluble binder resin, and an alcohol-soluble charge transport material. 2. An electrophotographic apparatus comprising the electrophotographic photoreceptor according to claim 1. 3. A process cartridge comprising the electrophotographic photosensitive member according to claim 1. 4. A dispersion obtained by dissolving and dispersing metal oxide particles, an alcohol-soluble binder resin, and an alcohol-soluble charge transporting material, the surface of which has been treated with a surface treatment agent, in a photosensitive layer provided on a substrate. A method for producing an electrophotographic photoreceptor in which a surface layer is formed by immersion in a photoreceptor.