JPH09197702A - Electrophotographic photoreceptor, image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material for an undercoat layer ensuring high image quality and not affecting electrical characteristics by incorporating a copolymer resin having hydrolyzable silyl groups and an electron transferring org. pigment into an undercoat layer forming material. SOLUTION: An undercoat layer contg. a copolymer resin having hydrolyzable silyl groups and an electron transferring org. pigment is formed. The copolymer resin is preferably an acrylic copolymer resin. The undercoat layer may further contain metal oxide particles. The copolymer resin is, e.g. a vinyl copolymer of a vinyl monomer having a hydrolyzable silyl group with other vinyl monomer copolymerizable with it. The org. pigment is, e.g. perylenetetracarboxylic acid diimide, diimidazole perylene-tetracarboxylate, polycyclic quinone or diimidazole naphthalenetetracaboxylate.

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 an improved undercoat layer, and an image forming method and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Electrophotographic devices are used in the fields of copying machines, laser beam printers, etc., because of their high speed and high printing quality. As a photoconductor used in an electrophotographic apparatus, an organic photoconductor (OPC) using an organic photoconductive material has been developed and is in widespread use. The photosensitive member is also composed of a single layer type photosensitive member in which a charge transfer type complex structure or a charge generating material is dispersed in a binder resin, and a function separation type photosensitive member structure in which a charge generating layer and a charge transport layer are separated. The performance has improved. In this function-separated type photoreceptor structure, at present, a structure in which an undercoat layer is formed on an aluminum substrate, and then a charge generation layer and a charge transport layer are formed, has become the mainstream. With the progress of electrophotographic devices, higher quality image quality has been required for the performance of the photoconductor. In order to improve the repetitive stability and environmental stability of the photoconductor, all of the charge generation layer, charge transport layer and subbing layer are important for the electrophotographic properties such as sensitivity, image quality and repetitive stability. Have an impact. Further, as the substrate, various materials such as an extruded tube, an ED tube, and an El tube have come to be used for the purpose of cost reduction and improvement of image quality defects. Furthermore, in order to reduce interference fringes, a method of roughening the surface of the substrate has also been studied.

However, the surface of the substrate has many defects such as crystallized substances, pickups and dents. For example, an ED tube used as a low-cost pipe has a peeling on the surface of an aluminum substrate called a pickup, and it has been found that its size reaches 20 μm. Such surface defects cause unevenness in the film-forming state of the photoconductor, which causes local concentration of an electric field when the photoconductor is charged and causes a charge leak. Further, when it is used in a contact charging process using a charging roll, the surface defects or coating film defects of the conductive substrate cause charge leakage between the charging roll and black spots or white spots at the leak point. Cause spot defects. If this phenomenon is significant, the charging ability of the charging roll itself is reduced, and charging failure is caused in the entire axial direction of the photoconductor.

Depending on the photoconductor, the aluminum substrate may be roughened by honing, rough cutting, etching or the like in order to prevent interference fringes. It may cause abnormal protrusions on the surface. Even in this case, there is a problem that an image quality defect occurs and a current leak occurs at the contact between the charging roll and the photoconductor. To solve these problems, it is effective to form an undercoat layer having sufficient substrate concealing ability and carrier blocking property on the surface of the substrate or to form a conductive layer to conceal defects in the substrate.

As the undercoat layer formed on the surface of the substrate, various resins such as maleic acid ester copolymers in JP-A-52-10138 and JP-A-52-2083 are disclosed.
A polyester resin is disclosed in JP-A-52-256.
Copolymerized nylon is disclosed in JP-A-52-10.
No. 0240 discloses polyvinyl alcohol, and
No. 2,121,325 discloses an epoxy resin, and JP-A No. 54-26379 discloses a styrene butadiene resin. Further, as a method for forming the conductive layer, a metal oxide such as titanium oxide or tin oxide is used as a polyamide resin (JP-A-61-110153), a phenol resin (JP-A-60-111255), or an epoxy resin. (JP-A-61-110153), urethane resin (JP-A-61-110153) and the like dispersed in a resin have been proposed.

However, when these undercoat layers or conductive layers are formed, secondary obstacles such as increase in residual potential and increase in environmental change occur in electrical characteristics, and image defects such as black spots or white spots occur. In many cases, the improvement effect of was not sufficient.

Attempts have also been made to add metal oxide fine particles or metal fine particles to the resin of the undercoat layer to reduce the resistance of the undercoat layer and to improve the electrical characteristics and the image quality. . However, when a metal oxide or metal fine particles are added, a conductive path is formed in the undercoat layer,
There are problems such as fogging and white spots due to the injection of holes from the substrate side. When used in a contact charging process using a charging roll, charge leakage is likely to occur between the charging roll and a photoconductor that does not cause an image quality defect when a normal scorotron is used. White spot-like spot defects are caused, or, if significant, the charging ability of the charging roll itself is reduced, resulting in poor charging over the entire axial direction of the photoconductor. In order to prevent this leakage, it is effective to make the undercoat layer as thick as possible. However, even if a conventional undercoat layer material can obtain good electrical characteristics up to a film thickness of about 1 μm, Further, when the film is made thicker, the residual potential is remarkably increased, and it is usually a level that cannot be used. In order to prevent current leakage due to the contact charging roll, it is desirable that the thickness of the undercoat layer be thicker than about 3 μm. There was a need for an undercoat layer without obstacles.

[0008]

DISCLOSURE OF THE INVENTION In view of the above points in the prior art, the present inventors have aimed to form a material for an undercoat layer having higher image quality and having no adverse effect on electrical characteristics. It is a thing. Therefore, an object of the present invention is to provide an electrophotographic photosensitive member having excellent electric characteristics and having few image quality defects. Another object of the present invention is to provide an electrophotographic photosensitive member capable of forming an image having no image quality defect when used in a contact charging type image forming method, and an image forming method and an image forming apparatus using the same. To do.

[0009]

The inventors of the present invention have investigated a material for forming an undercoat layer which has a high image quality and does not adversely affect the electric properties, and as a result, has found that a copolymer resin having a hydrolyzable silyl group and an electron transporting material are used. It has been found that the above-mentioned object is satisfied by containing a water-soluble organic pigment, and the present invention has been completed.

The present invention relates to an electrophotographic photosensitive member having an undercoat layer provided between a conductive substrate and a photosensitive layer, wherein the undercoat layer has a copolymer resin having a hydrolyzable silyl group and an electron transporting organic compound. It is characterized by containing a pigment. In the present invention, the copolymer having a hydrolyzable silyl group is preferably an acrylic copolymer resin. Further, the undercoat layer may contain metal oxide particles. The image forming method of the present invention comprises the steps of charging an electrophotographic photoreceptor, imagewise exposing it, developing it, and transferring and fixing it.
It is characterized in that the above-mentioned electrophotographic photosensitive member is used as the electrophotographic photosensitive member, a charging device is brought into contact with the surface of the electrophotographic photosensitive member, and an electric charge is supplied from the outside to charge the electrophotographic photosensitive member. The image forming apparatus of the present invention has an electrophotographic photosensitive member and a charger, and the electrophotographic photosensitive member is composed of the above-mentioned, and the charger contacts the surface of the electrophotographic photosensitive member, It is characterized by supplying more electric charge.

[0011]

Embodiments of the present invention will be described below in detail. The electrophotographic photosensitive member of the present invention has a structure in which an undercoat layer is formed on a conductive substrate, and a photosensitive layer is further formed thereon. The photoconductor is effective regardless of the layer structure, but since the laminated photoconductor having the charge transport layer as the surface layer is excellent in performance such as repeated stability and environmental change. preferable. Hereinafter, the laminated type photoreceptor having the charge transport layer as a surface layer will be mainly described.

As the conductive substrate, copper, aluminum,
In addition to metals such as nickel and iron, a cylindrical, belt-shaped or sheet-shaped substrate made of plastic or paper that has been made conductive by evaporating a metal on the surface or forming a coating film in which conductive powder is dispersed. Can be used. In order to prevent interference fringes, the surface of the conductive substrate can be roughened by a method such as etching, anodic oxidation, wet blasting method, sand blasting method, rough cutting, and centerless cutting.

An undercoat layer is provided on the conductive substrate. In the present invention, the undercoat layer contains a copolymer resin having a hydrolyzable silyl group and an electron-transporting organic pigment, but may contain other film-forming material. Further, for the purpose of accelerating the curing reaction, a hydrolyzable silyl group curing catalyst may be contained. Furthermore, when it is intended to reduce the resistance, conductive fine particles may be included. The undercoat layer includes a first undercoat layer containing conductive fine particles and a second undercoat layer containing no conductive fine particles.
It may have a two-layer structure with the undercoat layer.

In the present invention, the copolymer resin having a hydrolyzable silyl group used in the undercoat layer is a vinyl monomer (a) having a hydrolyzable silyl group, and other copolymerizable resin. A vinyl-based copolymer composed of a vinyl-based monomer (b) can be used. Examples of the hydrolyzable silyl group in the vinyl monomer (a) having a hydrolyzable silyl group include a halogenosilyl group, an acyloxysilyl group, an amidosilyl group, an amidoxysilyl group, an aminoxysilyl group, an alkenyloxysilyl group, Examples thereof include an aminosilyl group, an oxime silyl group, an alkoxysilyl group and a thioalkoxysilyl group. Preferred is an alkoxysilyl group.

Examples of the vinyl monomer (a) having an alkoxysilyl group include vinylsilanes (such as vinylmethyldimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris (β-methoxyethoxy) silane); alkoxysilyl. Group-containing acryloxy- or methacryloxyalkylsilanes (γ-
Methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltriethoxysilane and the like).

Other copolymerizable vinyl monomers (b) include, for example, (1) acryl- or methacrylic acid alkyl ester (wherein the alkyl group has 1 to 20 carbon atoms) [methyl acrylate, methyl methacrylate , Ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, etc.]; (2) Aromatic vinyl monomers [styrene, α-methylstyrene, α-chlorostyrene, etc.]; (3) Vinyl halide monomer [vinyl chloride, etc.]; (4) Alkyl or cycloalkyl vinyl ether [methyl vinyl ether, cyclohexyl vinyl ether, etc.]; (5) Vinyl ester [vinyl acetate, etc.]; (7) Amide group-containing vinyl monomer [acrylamide, methacrylamide, crotonamide, N-methylolacrylamide, fumaric acid diamide, etc.]; (8) Epoxy group-containing vinyl monomer [7] Glycidyl acrylate, glycidyl methacrylate, etc.]; (9) Fluorine Vinyl-based monomer having substituted alkyl group [perfluoroalkyl group-containing acrylic acid ester and methacrylic acid ester such as perfluorooctylethyl group, C ₈ F ₁₇ (CH ₂ ) ₁₁ OCOCH = C
Perfluoroalkyl group-containing maleates such _{HCOOCH 3, C 7 F 15 CH} 2 OCH = perfluoroalkyl group-containing vinyl ether of CH _2, etc., etc.]; (10)
Vinyl-based monomer containing polydimethylsiloxane [CH ₂ =
CHCOO (CH ₂ ) ₃ [Si (CH ₃ ) ₂ O] _n Si
_{(CH 3) 3, CH 2} = C (CH 3) COOC 6 H
₄ [Si (CH ₃ ) ₂ O] _n Si (CH ₃ ) ₃ , CH _{2
= C (CH 3) COO (} CH 2) 3 [Si (CH 3) 2
_{O] n Si (CH 3)} 3, CH 2 = C (CH 3) COO
(CH ₂ ) ₃ [Si (C ₆ H ₅ ) ₂ O] _n Si (C
H ₃ ) ₃ etc. (in each formula, n = 0 to 130)]; (11) unsaturated mono- or polycarboxylic acids [acrylic acid, methacrylic acid, crotonic acid, sorbic acid, maleic acid, itaconic acid, cinnamic acid Etc.]; (12) Aliphatic or aromatic vinyl sulfonic acid [vinyl sulfonic acid, allyl sulfonic acid,
Vinyltoluenesulfonic acid, styrenesulfonic acid, etc.];
(13) Acrylic and methacryl sulfonic acid esters [ethyl acrylate sulfonate, ethyl methacryl sulfonate, propyl acrylic sulfonate, propyl methacryl sulfonate, etc.]; and (14) polyoxyethylene group-containing vinyl monomer [CH ₂ = C (R) COOCH
₂ CH ₂ O (CH ₂ CH ₂ O) ₁ H, CH ₂ = C (R)
COOCH ₂ CH ₂ CH ₂ O (CH ₂ CH ₂ O) ₁ H,
CH ₂ = C (R) COOCH ₂ CH ₂ O (CH ₂ CH ₂
O) ₁ R ', CH ₂ = C (R) COOCH ₂ CH ₂ CH
₂ O (CH ₂ CH ₂ O) ₁ R '(in each formula, R = H or CH ₃ , l = 1 to 200, R' = C _{1 to} C ₁₀ alkyl group]; CH ₂ = C (R) COO (EO / PO) _m H, C
H ₂ = C (R) COO (EO / PO) _m R '(in both formulas,
R = H or CH ₃ , m = 1 to 200, EO is an oxyethylene group, PO is an oxypropylene group, EO / PO> 2
(Molar ratio), R ′ = C ₁ -C ₁₀ alkyl group)].

Among these other copolymerizable vinyl monomers (b), preferable ones are vinyl monomers containing anionic or nonionic hydrophilic group ((11) to (14) above). )), And particularly preferred is the polyoxyethylene group-containing vinyl monomer (14). Two or more kinds of the above vinyl-based monomers (b) may be used in combination. The proportion of the monomer (a) and the monomer (b) constituting the copolymer resin having a hydrolyzable silyl group is usually 0.01 to 80% by weight of the monomer (a), preferably 0.5 to 60% by weight, (B) is usually 20 to 99.99% by weight, preferably 40 to 99.5% by weight.

The copolymer resin having a hydrolyzable silyl group can be produced by radical polymerization such as thermal polymerization, photopolymerization or radiation polymerization of the above-mentioned monomer (a) and monomer (b). A preferred method is radical polymerization using a radical initiator for the monomer (a) and the monomer (b) in an organic solvent. As the organic solvent in radical polymerization, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, n-butyl acetate, cellosolve acetate, ethylene dichloride, or the like, or a mixture of two or more thereof can be used.

As the radical initiator, it is effective to use an azo compound (azobisisobutyronitrile, azobisisovaleronitrile, etc.). Further, in some cases, together with a radical initiator, a chain transfer agent (n-lauryl mercaptan, n-dodecyl mercaptan, mercaptopropionic acid, t-dodecyl mercaptan, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, etc.) Can be added to control the molecular weight. Although the molecular weight of the copolymer resin having a hydrolyzable silyl group is not particularly limited, it is usually 1,000.
Those of 100 to 100,000 are used.

As the curing catalyst used for the purpose of accelerating the curing reaction of the copolymer resin having a hydrolyzable silyl group, those conventionally used can be used. For example, organic titanate-based compounds (isopropyl triisostearoyl titanate, isopropyl tri (dioctyl pyrophosphate) titanate, tetraisopropyl di (lauryl phosphite) titanate, etc.), organoaluminum-based compounds (acetoalkoxy aluminum diisopropylate, etc.), carboxylic acid -Type tin compounds (tin dioctanoate, dibutyltin dilaurate, dibutyltin malate, etc.), sulfide-type or mercapto-type sulfur-containing organic tin compounds (dibutyltin sulfide, etc.), dialkyltin oxides (dibutyltin oxide, dioctyltin oxide, etc.) ), Carboxylic acid metal salts (sodium acetate, zinc caproate, lead octylate, cobalt naphthenate, etc.), acid phosphates (monomethyl acid phosphates, dimethyl acid phosphates) Ether, dimethyl acid phosphate esters,
Diethyl acidic phosphoric acid ester, monobutyl acidic phosphoric acid ester, etc., carboxylic acid and its acid anhydride (adipic acid, maleic acid, citric acid, itaconic acid, succinic acid, phthalic acid, trimellitic acid, maleic anhydride, phthalic anhydride) Etc.), aminosilane (γ-aminopropyltriethoxysilane etc.), amine and its salt (triethylamine,
Dibutylamine-2-hexoate, cyclic amidine and salts thereof, etc., quaternary ammonium salts (tetrabutylammonium hydroxide etc.) and the like. These curing catalysts may be used alone or in combination of two or more. When the curing catalyst is added, the addition amount is usually 0.001 to 20% by weight based on the copolymer resin.

In the present invention, the undercoat layer contains an electron-transporting organic pigment, whereby the electrons formed in the charge generation layer are rapidly moved to the substrate side, and the electrons are accumulated in the undercoat layer. As a result, the rise of the residual potential can be prevented, and stable electric characteristics can be obtained. That is, the inclusion of the electron-transporting organic pigment has the advantage that it can act as a sufficiently resistant layer against hole injection from the substrate, so that image quality defects due to injection can be prevented.

In the present invention, an electron-transporting organic pigment is used. Whether the organic pigment has a hole-transporting property or an electron-transporting property depends on whether the hole-transporting property is high or the electron-transporting property is high. It is determined by whether it is high. As a more specific discrimination method, for example, a coating film of several μm to 10 μm in which an organic pigment to be discriminated is dispersed in a binder resin is charged by both positive charging and negative charging. Is higher in sensitivity, and if negatively charged shows higher sensitivity, it is determined as an electron-transporting organic pigment. Also,
For some pigments, the pigment alone cannot form a carrier. As a determination method in this case, a submicron-order charge generation layer made of different materials is formed on a coating film of several μm to 10 μm in which an organic pigment to be determined is dispersed in a binder resin. By irradiating light of a wavelength having sensitivity to form a carrier, the carrier is injected into the organic pigment in the lower layer, and the transport polarity of the organic pigment is determined depending on which charging polarity causes a larger potential decay. Is the way. As another method, a thin charge transport layer having a thickness of submicron to 1 μm is formed on a coating film having an organic pigment dispersed therein of several μm to 10 μm, and the organic pigment to be distinguished is irradiated with light having sensitivity. As a result, carriers are formed at the pigment / thin layer charge transport layer interface, and the carriers are injected into the organic pigment layer, and it is determined by which charging polarity causes greater potential attenuation.

Examples of the compounds of the electron-transporting organic pigment thus identified are perylene tetracarboxylic acid diimide pigments, perylene tetracarboxylic acid diimidazole pigments, polycyclic quinone pigments, anthraquinone acridone pigments, and naphthalene tetracarboxylic acid. Examples include diimidazole pigments. More specifically, as the perylene tetracarboxylic acid diimide pigment, the following exemplary compound N
o. 1-1 to No. 1-10, and as the perylene tetracarboxylic acid diimidazole pigment, the following exemplary compound No. 2-1 to No. 2-7, and as the anthraquinone acridone pigment, the following exemplary compound N
o. 3-1 to No. 3-40, and as the polycyclic quinone pigment, the following exemplified compound No. 4-1 to No. Four
-41, and as the naphthalenetetracarboxylic acid diimidazole pigment, the following exemplified compound No. 5-1
-No. 5-9 can be given.

(Specific Examples of Perylene Tetracarboxylic Acid Diimide Pigment)

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[0025]

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(Specific Examples of Perylene Tetracarboxylic Acid Diimidazole Pigment) The cis form and the cis / trans form mixture are omitted.

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[0027]

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(Specific examples of anthraquinone acridone pigment)

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[0029]

[Chemical 6]

[0030]

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[0031]

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[0032]

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[0033]

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(Specific examples of polycyclic quinone pigment)

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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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(Specific examples of naphthalenetetracarboxylic acid diimidazole pigment)

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[0041]

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In the present invention, in addition to the above copolymer resin having a hydrolyzable silyl group and the electron transporting organic pigment, another film forming material can be used in the undercoat layer. Materials that can be used in combination include acetal resins such as polyvinyl butyral, polyvinyl alcohol resins, casein, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins. In addition to polymer compounds such as vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin and melamine resin, zirconium, titanium,
Examples thereof include organometallic compounds containing aluminum, manganese, silicon atoms and the like. These compounds can be used alone or as a mixture or polycondensation product of a plurality of compounds. Among them, organometallic compounds containing zirconium or silicon atoms are excellent in performance such as low residual potential, little potential change due to environment, and little potential change due to repeated use.

Examples of the organometallic compound containing a silicon atom include vinyltrimethoxysilane, vinyltriethoxysilane and vinyltris (β-methoxyethoxy).
Silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane , Vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ
-Aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane,
N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ −
Examples thereof include silicon compounds such as chloropropyltrimethoxysilane. Among these, particularly preferably used silicon compounds are vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and β- (3. 4-epoxycyclohexyl) ethyltrimethoxysilane, N-β
-(Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane , Γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like.

Examples of organometallic compounds containing zirconium atoms are zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate. , Zirconium phosphonate, zirconium octoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

Examples of the organic metal compound containing a titanium atom include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate and titanium octyl. Examples thereof include ren glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanolaminate, and polyhydroxytitanium stearate.

Examples of the organometallic compound containing an aluminum atom include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate) and the like. . The above matrix components can be added in the range of 1 to 70% by weight based on the total weight of the solid content of the undercoat layer.

In the undercoat layer, various organic or inorganic fine powders different from the electron-transporting organic pigments may be mixed for the purpose of preventing light interference and preventing interference fringes or improving dispersibility. it can. In particular, white pigments such as titanium oxide, zinc oxide, zinc sulfide, lead white, and lithopone, extender pigments such as alumina, calcium carbonate, barium sulfate, Teflon resin particles, benzogranamine resin particles, styrene resin particles and the like can be mentioned. . These may be added in an amount of 1 to 80% by weight, preferably 5 to 70% by weight, and more preferably 30 to 60% by weight, based on the solid content of the undercoat layer.

The particle size of the above-mentioned fine particles is appropriately set, and those having a particle size of 0.01 to 3 μm are usually used, but especially 0.05
A range of ˜1 μm is suitable. If the particle size is too large, the unevenness of the undercoat layer becomes severe and electrical non-uniformity becomes large, and image quality defects are likely to occur. If it is less than 0.01 μm, a sufficient light scattering effect cannot be obtained.

In the formation of the coating liquid for forming the undercoat layer, the electron-transporting organic pigment and other fine particles are added to the liquid containing the resin component and the dispersion treatment is carried out. As a method for performing the dispersion treatment, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, or the like can be used. The undercoat layer can be formed by a spray coating method, a ring coating method, a dip coating method or the like in the case of a drum photoreceptor, and a spray coating method, a bead coating method, in the case of a belt-shaped photoreceptor. It can be formed using a curtain coating method, a slot coating method, or the like.

By increasing the thickness of the undercoat layer,
Since the concealment of the irregularities of the support is enhanced, the image quality defect is generally reduced when the film thickness is increased, but the electrical repeatability is deteriorated, and therefore, it is preferably in the range of 0.1 to 5 μm. . However, when the undercoat layer contains an electron-transporting organic pigment, the deterioration in electrical characteristics is small even if the film is thickened, so that the thickness can be set within the range of 10 μm. Furthermore, the thicker the film, the less likely it is that a leak defect will occur even in a charging method such as a contact charging method in which current leakage is likely to occur. Therefore, in the present invention, the film thickness of the undercoat layer when the electron transporting organic pigment is contained can be set in the range of 2 to 10 μm.

The charge generation layer formed on the undercoat layer is formed by vacuum deposition of the charge generation material or by dispersing and coating the charge generation material together with an organic solvent and a binder resin. As the charge generating material, amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, zinc oxide, inorganic photoconductive materials such as titanium oxide, metal-free phthalocyanine, Titanyl phthalocyanine, copper phthalocyanine,
Various phthalocyanine pigments such as tin phthalocyanine, gallium phthalocyanine, and chloroindium phthalocyanine,
Various organic pigments and dyes such as squarylium-based aromatic polycyclic compounds such as anthanthrone-based, perylene-based, azo-based, anthraquinone-based, and pyrene-based compounds, pyrylium salts, and thiapyrylium salts are used. In addition, these organic pigments generally have several crystal forms, and in particular, phthalocyanine pigments are known to have various crystal forms such as α and β, but a sensitivity suitable for the purpose can be obtained. Any crystal type can be used as long as it is a pigment.

Examples of the binder resin in the charge generation layer include the following. That is, polycarbonate resin such as bisphenol A type, bisphenol Z type or bisphenol C type, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinylidene chloride- Examples thereof include acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole and the like.

These binder resins can be used alone or in admixture of two or more. 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. The film thickness of the charge generation layer is generally set in the range of 0.01 to 5 μm, preferably 0.05 to 2.0 μm. As a method for dispersing the charge generation material in the resin, a roll mill, a ball mill, a vibrating ball mill, an attritor, a dyno mill, a sand mill, a colloid mill or the like can be used.

Examples of the charge transport material used in the charge transport layer include the following. Oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenylpyrazoline, 1- [pyridyl- (2)]-3 -(P
-Diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline and other pyrazoline derivatives, triphenylamine, tri (p-methyl) phenylamine,
Aromatic tertiary amino compounds such as N, N-bis (3,4-dimethylphenyl) biphenyl-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-
1,4,4-Triazine derivatives such as (4′-methoxyphenyl) -1,2,4-triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 2-phenyl-4-styrylquinazoline Quinazoline derivatives such as 6-hydroxy-2,3
Benzofuran derivatives such as di (p-methoxyphenyl) benzofuran, p- (2,2-diphenylvinyl)-
Hole-transporting substances such as α-stilbene derivatives such as N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and its derivatives; quinone compounds such as chloranil, bromoanil and anthraquinone Electrons of compounds, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone, xanthone compounds, thiophene compounds, diphenoquinone compounds Examples thereof include a transport substance; and a polymer having a group composed of the above compound in its main chain or side chain. These charge transport materials can be used alone or in combination of two or more.

Examples of the binder resin used in the charge transport layer include acrylic resin, polyarylate, polyester resin, polycarbonate resin such as bisphenol A type, bisphenol Z type or bisphenol C type, polystyrene, acrylonitrile-styrene copolymer. , Acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone,
Examples thereof include insulating resins such as polyacrylamide, polyamide and chlorinated rubber, and organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene and polyvinylpyrene.

For the charge transport layer, a solution prepared by dissolving the above charge transport material and binder resin in a suitable solvent is applied,
It can be formed by drying. Examples of the solvent used for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene and chlorobenzene, ketones such as acetone and 2-butanone, halogenated fats such as methylene chloride, chloroform and ethylene chloride. Group hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, dioxane, ethylene glycol, diethyl ether, and mixed solvents thereof can be used.
The compounding ratio of the charge transport material and the binder resin is 10: 1 to
A range of 1: 5 is preferred. The thickness of the charge transport layer is
Generally, it is set in the range of 5 to 50 μm, preferably 10 to 40 μm.

Additives such as antioxidants, light stabilizers and heat stabilizers in the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone or oxidizing gas generated in the electrophotographic apparatus, or light or heat. Can be added. For example, 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, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

Further, for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use, at least one electron-accepting substance may be contained. Examples of the electron accepting substance that can be used in the electrophotographic photoreceptor of the present invention include:
For example, succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrate. Examples thereof include nitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid and phthalic acid. Of these, fluorenone type, quinone type, Cl, CN, NO ₂
Particularly preferred are benzene derivatives having electron-withdrawing substituents such as

The coating can be carried out using a coating method such as a dip coating method, a spray coating method, a bead coating method, a blade coating method or a roller coating method. In the case of not using a humidification treatment method, it is preferable to heat-dry after touch-drying at room temperature. The heat drying is preferably performed at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours.

If necessary, a surface protective layer can be formed on the photosensitive layer. As the surface protective layer, there is an insulating resin protective layer or a low resistance protective layer in which a resistance adjusting agent is added to the insulating resin. In the case of the low resistance protective layer, for example, a layer in which conductive fine particles are dispersed in an insulating resin can be used. Electrically conductive particles have an electrical resistance of 10 ⁹ Ω.
Fine particles having an average particle size of 0.3 μm or less, preferably 0.1 μm or less, which exhibits a white, gray or bluish white color at 10 cm or less, for example, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, oxide Examples thereof include a solid solution or mixture of indium, tin oxide and antimony or antimony oxide, or a mixture of these metal oxides in a single particle or a coated material. Among them, tin oxide, and a solid solution of tin oxide and antimony oxide or antimony oxide are preferable because they can appropriately adjust the electric resistance and can make the protective layer substantially transparent (special characteristics). Kaisho 57-30847
Japanese Patent Laid-Open No. 57-128344).
As an insulating resin. Examples thereof include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene and polyacrylamide.

The electrophotographic photosensitive member of the present invention is a light lens type copying machine, a laser beam printer emitting near infrared light or visible light, a digital copying machine, an LED printer,
It can be used for an electrophotographic apparatus such as a laser facsimile. The electrophotographic photosensitive member of the present invention may use either a one-component or two-component regular developer or a reversal developer.

Next, the image forming apparatus and the image forming method of the present invention will be described. FIG. 1 shows an example of an image forming apparatus using the electrophotographic photosensitive member of the present invention.
A charger 3 to which a voltage is supplied from a power source 2 provided outside the apparatus is disposed on the photosensitive drum 1 so as to contact the surface thereof. An image input device 4, a developing device 5, a pressure transfer device or an electrostatic transfer device 6, a cleaner mechanism 9, and a de-exposure device 10 are provided around the photosensitive drum 1. In addition,
Reference numeral 7 is a sheet, and 8 is a fixing device. In the image forming apparatus of the present invention, a charging roll is shown as the charging device, but a charging brush or a blade type film charging device may be used. A DC voltage is applied to the charger from a power source 2 provided outside the apparatus, but an AC voltage may be superimposed and applied on the DC voltage in order to improve the uniformity of charging.

The image forming method of the present invention is carried out as follows. That is, the surface of the photosensitive drum 1 is generally supplied with 50 to 2000 V from the power source 2 provided outside the apparatus.
It is charged by the charger 3 to which a DC voltage in the range is applied. For example, in the case of a method in which the conductive elastic roller is brought into contact with the surface of the photoconductor, a DC voltage of about 1 to 2 KV may be applied. Next, an electrostatic latent image is formed by exposure with light from an image input device 4 such as an optical system for irradiating a document image or a laser or LED. The formed electrostatic latent image is visualized as toner by the developing device 5 and converted into a toner image. In this case, a magnetic brush method can be used for development. Then, the toner image is transferred onto the sheet 7 by the pressure transfer device or the electrostatic transfer device 6 and fixed by the fixing device 8. On the other hand, the toner remaining on the surface of the photosensitive drum 1 after the transfer is removed by the cleaner mechanism 9 using a blade, and the electric charge slightly remaining on the surface of the photosensitive drum 1 is erased by the deexposure device 10.

[0064]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 Hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Kasei Co., Ltd.) (consisting of three monomer components of methyl methacrylate, butyl acrylate and γ-methacryloxypropyltrimethoxysilane, The composition ratio (molar ratio) is 38:35:27, the number average molecular weight is 11,000,
60 parts by weight of xylene was added to 33 parts by weight of an acrylic copolymer resin base having a weight average molecular weight of 34,000 and stirred. Further, to this mixture, as an electron-transporting pigment, the exemplified compound No. 39 parts by weight of 4-6 was added, and a dispersion treatment was performed for 3 hours by a sand mill. In addition to this mixture 0.
3 parts by weight of an organotin compound catalyst (S-CAT.24, manufactured by Sankyo Machine Gosei Co., Ltd.) was added and stirred to prepare a coating liquid for forming an undercoat layer. This coating solution was roughened to Ra = 0.18 μm by liquid honing treatment, and then E of 30 mmφ was used.
Coating on a D-tube aluminum substrate using a ring coating device and curing treatment at 150 ° C. for 1 hour to give a film thickness of 5 μm.
Was formed. As a charge generating material, a mixed solution of 15 parts by weight of gallium phthalocyanine chloride, 10 parts by weight of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.), and 300 parts by weight of n-butyl alcohol was dispersed by a sand mill for 4 hours. Processed. The obtained dispersion was applied onto the undercoat layer by dip coating and dried to form a charge generation layer having a thickness of 0.2 μm. Next, N, N '
-Diphenyl-N, N'-bis (3-methylphenyl)
4 parts by weight of-[1,1'-biphenyl] -4,4'-diamine and 6 parts by weight of a bisphenol Z polycarbonate resin (molecular weight 40,000) were added to 80 parts by weight of chlorobenzene and dissolved. The obtained solution was applied onto the charge generation layer and dried to form a charge transport layer having a film thickness of 20 μm, and an electrophotographic photoreceptor having three layers was produced. A printer (PC-P) having a contact charging system is provided with the obtained electrophotographic photoreceptor.
R1000 / 4R, manufactured by NEC Corporation), and a copying operation was performed. The results obtained regarding the residual potential and the image quality of the electrophotographic photosensitive member at that time are shown in Table 1 below.

The electron transporting property was confirmed as follows. In Example 1, a drum in which the undercoat layer and the charge generation layer according to the present invention were formed on a conductive substrate was prepared. This drum was charged to −200 V by using a scorotron and irradiated with light of 780 nm to excite photocarriers in the charge generation layer. As a result, a light attenuation characteristic of 10 V · m ² / mJ was obtained. On the other hand, this same drum +20
When light was charged to 0 V and the same light irradiation was performed, no light attenuation was observed. Therefore, Exemplified Compound No. used in the undercoat layer in the present invention. It was confirmed that the pigment of 4-6 was an electron-transporting pigment.

Comparative Example 1 Hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Chemical Industries) (from three monomer components of methyl methacrylate, butyl acrylate and γ-methacryloxypropyltrimethoxysilane) The composition ratio (molar ratio) is 38:35:27, and the number average molecular weight is 11,000.
40 parts by weight of xylene was added to 33 parts by weight of an acrylic copolymer resin base having a weight average molecular weight of 34,000 and stirred. To the resulting solution, 0.3 parts by weight of the organotin compound catalyst (S
-CAT. No. 24, manufactured by Sankoki Gosei Co., Ltd.) was added and stirred. This coating liquid was subjected to liquid honing treatment to obtain Ra =
Using a ring coating device, it was coated on a 30 mmφ ED tube aluminum substrate roughened to 0.18 μm.
Curing treatment was performed at 0 ° C. for 1 hour to form an undercoat layer having a film thickness of 5 μm. Further, an undercoat layer, a charge generation layer and a charge transport layer were sequentially formed in the same manner as in Example 1 to prepare an electrophotographic photoreceptor. The obtained electrophotographic photosensitive member was evaluated in the same manner as in Example 1, and the results shown in Table 1 were obtained.

[0067]

[Table 1]

Example 2 60 parts by weight of xylene was added to 33 parts by weight of the hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Kasei Co., Ltd.) used in Example 1. In the obtained solution, as an electron transporting pigment, the exemplified compound No. 60 parts by weight of 2-1 was added, and a dispersion treatment was carried out for 20 hours with a ball mill. The obtained dispersion liquid was subjected to liquid honing treatment to Ra = 0.1.
A 30 mmφ ED tube aluminum substrate roughened to 8 μm was coated using a ring coating device and cured at 170 ° C. for 1 hour to form an undercoat layer having a thickness of 4 μm. As a charge generating material, a mixed solution of 15 parts by weight of hydroxygallium phthalocyanine, 10 parts by weight of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.), and 300 parts by weight of n-butyl alcohol was subjected to dispersion treatment for 4 hours by a sand mill. The obtained dispersion was applied onto the undercoat layer by dip coating and dried to form a charge generation layer having a thickness of 0.2 μm. Next, N, N-bis (3,4-
4 parts by weight of dimethylphenyl) biphenyl-4-amine and bisphenol Z polycarbonate resin (molecular weight 40,000)
6 parts by weight and 80 parts by weight of chlorobenzene were added and dissolved. The obtained solution was applied onto the charge generation layer and dried to form a charge transport layer having a film thickness of 20 μm, and an electrophotographic photosensitive member having three layers was produced. The obtained electrophotographic photosensitive member was mounted on a printer (PC-PR1000 / 4R, manufactured by NEC Corporation) having a contact charging system, and a copying operation was performed. Table 2 shows the results obtained regarding the residual potential and the image quality of the electrophotographic photosensitive member at that time.

Examples 3 and 4 In the hydrolyzable silyl group-containing acrylic resin shown in Example 2, methyl methacrylate, butyl acrylate, γ-
The composition ratio (molar ratio) of the monomer component of methacryloxypropyltrimethoxysilane was changed to 25:23:52 (Example 3) and 46:43:11 (Example 4) to change the hydrolyzable silyl group. Example 2 containing the acrylic resin containing
An undercoat layer was formed in the same manner as in. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as shown in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner. Table 2 shows the obtained results.

Example 5 Using azobisisobutyronitrile as a radical polymerization initiator, CF ₃ (CF ₂ ) ₅ (CH ₂ ) _{2 in} xylene was used.
A copolymer resin was synthesized by copolymerizing 50 parts by weight of OCOCH = CH _2, 47 parts by weight of n-butyl acrylate, and 3 parts by weight of γ-mercaptopropyltrimethoxysilane.
Using this resin, an undercoat layer was formed by the same method as in Example 2, and a charge generation layer and a charge transport layer were sequentially formed thereon under the same conditions as in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner.
Table 2 shows the obtained results.

Comparative Example 2 In Example 2, 60 parts by weight of xylene was added to 33 parts by weight of a hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Chemical Industry Co., Ltd.) and stirred. A coating solution was obtained in the same manner without adding the electron-transporting pigment in Example 2 to the obtained solution. This coating solution was applied on a 30 mmφ ED tube aluminum substrate roughened to Ra = 0.18 μm by liquid honing using a ring coating device, and dried at 170 ° C. for 1 hour to perform a curing treatment. hand,
An undercoat layer having a thickness of 4.8 μm was formed. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner. Table 2 shows the obtained results.

Comparative Example 3 In Example 2, 18 parts by weight of a polyamide resin (laccamide 5003, Dainippon Ink and Chemicals, Inc.) was used in place of the hydrolyzable silyl group-containing acrylic resin used in the undercoat layer, and 17 parts by weight of methanol was used. Parts and 17 parts by weight of water. In the obtained solution, as an electron transporting pigment, the exemplified compound No. 60 parts by weight of 2-1 was added, and a dispersion treatment was carried out for 20 hours with a ball mill. The obtained dispersion liquid was applied onto a 30 mmφ ED tube aluminum substrate roughened to Ra = 0.18 μm by liquid honing using a ring coating device, dried at 150 ° C. for 30 minutes and cured. Then, an undercoat layer having a film thickness of 4.1 μm was formed. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner. Table 2 shows the obtained results.

Comparative Example 4 In Example 2, 18 parts by weight of methyl methacrylate resin (Elvsite 2021, manufactured by DuPont) was used instead of the hydrolyzable silyl group-containing acrylic resin used for the undercoat layer, and 34 parts by weight of xylene was used. And mixed to dissolve.
The obtained solution was used as an electron-transporting pigment, and the exemplified compound No. Add 60 parts by weight of 2-1 and add 20 to 20 with a ball mill.
Time-dispersed processing was performed. The obtained dispersion liquid was roughened to Ra = 0.18 μm by liquid honing treatment.
It was applied onto an ED tube aluminum substrate having a diameter of mmφ using a ring coating device, dried at 150 ° C. for 30 minutes and cured to form an undercoat layer having a thickness of 4.1 μm. Further thereon, the charge generation layer shown in Example 2 was formed.
The undercoat layer was dissolved to form a coating film with severe coating defects, and the photoreceptor could not be formed.

Example 6 Hydrolyzable silyl group-containing copolymer resin (consisting of three monomer components of methyl methacrylate, butyl acrylate and γ-methacryloxypropyltrimethoxysilane, the composition ratio (molar ratio) thereof) Is 25:23:52, 33 parts by weight of an acrylic copolymer resin having a number average molecular weight of 11,000 and a weight average molecular weight of 34,000, and 25 parts of xylene.
Parts by weight were added. In the obtained solution, as an electron transporting pigment, the exemplified compound No. 39 parts by weight of 4-6 was added, and a dispersion treatment was carried out for 3 hours with a sand mill. The obtained dispersion was mixed with 5 parts by weight of zirconium acetylacetonate tetrabutoxide (ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.).
The obtained coating liquid was subjected to liquid honing treatment to obtain Ra =
Using a ring coating device, it was coated on a 30 mmφ ED tube aluminum substrate roughened to 0.18 μm.
Curing treatment was performed at 0 ° C. for 1 hour to form an undercoat layer having a film thickness of 5.3 μm. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner. Table 2 shows the obtained results.

Example 7 25 parts by weight of xylene was added to 33 parts by weight of the hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Chemical Industry Co., Ltd.) used in Example 1. In the obtained solution, as an electron transporting pigment, the exemplified compound No. 39 parts by weight of 4-5 was added, and a dispersion treatment was carried out for 3 hours with a sand mill. Γ-Aminopropyltriethoxysilane (A
1100, manufactured by Nippon Unicar Co., Ltd.) 30 parts by weight were mixed.
Ra by liquid honing using the obtained coating liquid
= 30 mmφ ED tube aluminum substrate roughened to 0.18 μm was coated using a ring coating device and cured at 170 ° C. for 1 hour to give a film thickness of 4.5 μm.
Was formed. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as in Example 2. Regarding the obtained electrophotographic photoreceptor, Example 2
A copying operation was performed in the same manner as in, and the same evaluation was performed. Table 2 shows the obtained results.

[0076]

[Table 2]

Examples 8-12 and Comparative Examples 5-7 33 parts by weight of the same hydrolyzable silyl group-containing copolymer resin (SA246, Sanyo Kasei Co., Ltd.) as used in Example 1 was added with 25 parts by weight of xylene. added. To the resulting solution, 39 parts by weight of the organic pigment shown in Table 3 was added as an electron-transporting pigment, and a dispersion treatment was performed for 3 hours with a sand mill. In these organic pigments, those of Examples 8 to 12 are electron transporting organic pigments, and those of Comparative Examples 5 to 7 are hole transporting pigments. The obtained dispersion liquid is subjected to R by liquid honing treatment.
a using a ring coating device on an ED tube aluminum substrate of 30 mmφ roughened to a = 0.18 μm,
Curing treatment was carried out at 170 ° C. for 1 hour to form an undercoat layer having a film thickness of about 5 μm. Further thereon, a charge generation layer and a charge transport layer were sequentially formed under the same conditions as in Example 2. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 2 and evaluated in the same manner. Table 3 shows the obtained results.

[0078]

[Table 3]

Example 13 To 33 parts by weight of a hydrolyzable silyl group-containing copolymer resin (SA246, manufactured by Sanyo Chemical Industries, Ltd.) similar to that used in Example 1, 60 parts by weight of xylene was added and mixed and stirred. In the obtained solution, as an electron transporting pigment, the exemplified compound No.
39 parts by weight of 4-6 was added, and dispersion treatment was performed for 3 hours by a sand mill. 0.3 parts by weight of an organotin compound catalyst (S-CAT.24, manufactured by Sankyoki Gosei Co., Ltd.) was added to the obtained dispersion liquid, and the mixture was stirred to obtain a coating liquid for forming an undercoat layer. Ra = 0.18 by liquid honing using this coating liquid.
Coating is performed on a 30 mmφ ED tube aluminum substrate roughened to μm using a ring coating device, and the temperature is 150 ° C.
Cured for 1 hour to give a film thickness of 1, 3, 5 and 8 μm
Was formed. As a charge generating material, a mixed solution of 15 parts by weight of gallium phthalocyanine chloride, 10 parts by weight of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.), and 300 parts by weight of n-butyl alcohol was dispersed by a sand mill for 4 hours. Processed. The obtained dispersion was applied onto the undercoat layer by dip coating and dried to form a charge generation layer having a thickness of 0.2 μm. Next, N, N-
4 parts by weight of bis (3,4-dimethylphenyl) biphenyl-4-amine and 6 parts by weight of bisphenol Z polycarbonate resin (molecular weight 40,000) were added to 80 parts by weight of chlorobenzene and dissolved. The obtained solution was applied onto the charge generation layer and dried to form a charge transport layer having a film thickness of 20 μm, and an electrophotographic photoreceptor having three layers was produced. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 1 and evaluated in the same manner. Table 4 shows the obtained results.

Comparative Example 8 50 parts by weight of xylene was added to 33 parts by weight of the same hydrolyzable silyl group-containing copolymer resin (SA246, Sanyo Kasei Co., Ltd.) used in Example 1 and mixed and stirred. Without adding an electron-transporting pigment, 0.3 part by weight of an organotin compound catalyst (S-CAT.24, manufactured by Sankyo Machine Gosei Co., Ltd.) was added to the obtained solution and stirred to form an undercoat layer. A coating solution for use was obtained. Ra is applied by liquid honing using this coating liquid.
= 30 mmφ ED tube aluminum substrate roughened to 0.18 μm was coated using a ring coating device and cured at 150 ° C. for 1 hour to obtain a film thickness of 1, 3, 5
And an undercoat layer of 8 μm was formed. A charge generation layer and a charge transport layer similar to those in Example 13 were formed on this undercoat layer to prepare an electrophotographic photoreceptor having three layers. The obtained electrophotographic photosensitive member was subjected to a copying operation in the same manner as in Example 1 and evaluated in the same manner. Table 4 shows the obtained results.

[0081]

[Table 4]

As shown in Table 4, the electrophotographic photosensitive member of Example 13 using the electron-transporting pigment shows good electric characteristics even if the thickness of the undercoat layer is changed. Indicated. Further, in the electrophotographic photosensitive member of Comparative Example 8 in which the electron-transporting pigment was not used, the residual potential increased significantly as the film thickness increased, and an image could not be obtained.

[0083]

As described above, the electrophotographic photoreceptor of the present invention uses the copolymer resin containing a hydrolyzable silyl group and the electron-transporting organic pigment for forming the undercoat layer. The environment dependence is small, and even if the contact charging method is used, there is no current leakage, and a copy image of excellent image quality can be formed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a printer device used in an image forming method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 2 ... Power supply, 3 ... Charging device, 4 ... Image input device, 5 ... Developing device, 6 ... Pressure transfer device or electrostatic transfer device, 7 ... Paper, 8 ... Fixing device, 9 ... Cleaner mechanism 1
0 ... Exposing device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Gojima 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Takaaki Kimura 1600 Takematsu, Minami Ashigara City, Kanagawa Prefecture, Fuji Xerox Co., Ltd.

Claims (7)

[Claims] 1. An electrophotographic photosensitive member having an undercoat layer provided between a conductive substrate and a photosensitive layer, wherein the undercoat layer comprises a copolymer resin having a hydrolyzable silyl group and an electron transporting organic pigment. An electrophotographic photoreceptor containing the same. 2. The electrophotographic photoreceptor according to claim 1, wherein the copolymer resin having a hydrolyzable silyl group is an acrylic copolymer resin. 3. The electrophotographic photosensitive member according to claim 4, wherein the electron transporting pigment is a polycyclic quinone pigment. 4. The electrophotographic photosensitive member according to claim 4, wherein the electron transporting pigment is a perylene pigment. 5. The electrophotographic photosensitive member according to claim 4, wherein the electron transporting pigment is a naphthalenetetracarboxylic acid diimidazole pigment. 6. An image forming method comprising the steps of charging, imagewise exposing, developing, and transferring and fixing an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member according to claim 1 is used as the electrophotographic photosensitive member. An image forming method, characterized in that a container is brought into contact with the surface of the electrophotographic photosensitive member, and an electric charge is supplied from the outside to charge. 7. An image forming apparatus having an electrophotographic photosensitive member and a charger, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1, and the charger is the surface of the electrophotographic photosensitive member. An image forming apparatus characterized in that the image forming apparatus is a charger which is brought into contact with a battery and supplies an electric charge from the outside.