JP2012194305A - Electrophotographic photoreceptor, image forming method using the same, image forming apparatus, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that has few adverse effects such as rise of residual potential, reduction in charging capacity, or image deletion occurring after long-term use; is stable for a long period; and exhibits excellent wear resistance.SOLUTION: An electrophotographic photoreceptor consists of a photosensitive layer and a crosslinked surface layer on a substrate. The crosslinked surface layer has a crosslinked resin and a portion derived from a compound represented by the general formula (1).

Description

  The present invention relates to an electrophotographic photosensitive member having a cross-linked surface layer having a high cross-linking density and uniform and good electrical characteristics, and an image forming method, an image forming apparatus and a process cartridge using the same.

In recent years, organic photoreceptors (OPC) have been widely used in copying machines, facsimile machines, laser printers, and composite machines in place of inorganic photoreceptors because of their good performance and various advantages. This is because, for example, (1) optical characteristics such as the light absorption wavelength range and the amount of absorption, (2) electrical characteristics such as high sensitivity and stable charging characteristics, and (3) material selection range (4) Ease of manufacturing, (5) Low cost, (6) Non-toxicity, and the like.
Recently, the diameter of the photoconductor has been reduced due to the downsizing of the image forming apparatus, and the speed of the machine and the maintenance-free movement have been added, so that an electrophotographic photoconductor having high durability and good electrical characteristics is desired. It has become.

As a wear-resistant technique for a photosensitive layer, Patent No. 3194392 of Patent Document 1 contains a monomer having a carbon-carbon double bond, a charge transporting agent having a carbon-carbon double bond, and a binder resin. Providing a cured charge transport layer is disclosed.
This binder resin includes those having a carbon-carbon double bond and having reactivity with the charge transfer agent and those having no double bond and not having reactivity. This photoconductor is remarkably compatible with wear resistance and good electrical properties, but when a non-reactive binder resin is used, the binder resin, the monomer and the charge transport agent are used. Poorly compatible with the cured product produced by this reaction, phase separation occurs in the cross-linked surface layer, and locally low wear-resistant portions are formed, which can cause scratches on the photoreceptor surface, toner external additives and paper dust. May cause sticking.

Patent No. 4145820 of Patent Document 2 is provided with a crosslinked layer obtained by curing a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a monofunctional radical polymerizable compound having a triarylamine structure. By setting the elastic displacement rate τe of the cross-linked surface layer to 35% or more and the standard deviation of the elastic displacement rate τe to within 2%, high durability and high image quality can be realized over a long period of time. An electrophotographic photoreceptor is disclosed.
However, as a result of further investigation by the present inventors, a compound having a triarylamine structure is subjected to light energy irradiation such as formation of a crosslinked surface layer, so that a part of the charge transporting structure in the crosslinked surface layer is oxidized and decomposed. It has been found that the charge transport structure becomes inhomogeneous due to the chemical reaction, and the residual potential increases, the chargeability decreases, and long-term use causes image flow.

Japanese Patent No. 3244951 of Patent Document 3 discloses that triphenylamine having at least two phenyl groups having three alkyl groups is used to prevent the charge transport material from crystallizing and phase separation. However, it is not dispersed in the cross-linked resin and does not take into consideration the balance with the development of the three-dimensional network structure.

  The present invention uses a charge transport material that is unlikely to cause oxidation and decomposition due to light energy irradiation and does not hinder the cross-linking of the surface layer, increases residual potential, decreases chargeability, image flow that occurs during long-term use, etc. It is an object of the present invention to provide an electrophotographic photosensitive member that has less side effects, is stable in the long term, and has excellent wear resistance, a process cartridge, an image forming apparatus, and an image forming method using the photosensitive member.

The above-mentioned problem is that a triphenylamine structure is formed by introducing a substituent in the ortho position with respect to N in at least one phenyl group of the triphenylamine structure, by light irradiation at the time of forming a crosslinked surface layer, long-time exposure, and the like. This is solved by preventing changes in the structure of the compound.
That is, the said subject is solved by following (1)-(7) of this invention.
(1) The substrate has at least a photosensitive layer and a crosslinked surface layer, and the crosslinked surface layer has at least a crosslinked resin and a site derived from a compound having a triphenylamine structure represented by the general formula (1). An electrophotographic photoreceptor, characterized in that

〔一般式（１）中、Ｒ３、Ｒ４、Ｒ８、Ｒ９、Ｒ１３、Ｒ１４は、それぞれ水素原子、ハロゲン原子、アルキル基、アルコキシ基、又は、アリール基を表し、すべてが水素原子であることはない。Ｒ１、Ｒ２、Ｒ５、Ｒ６、Ｒ７、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１５は、それぞれ、水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアルコキシ基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、置換基を有してもよいアルキレン基、シアノ基、ニトロ基、又は−ＯＣＯ＝ＣＨ_２Ｒ１６を表し、Ｒ１６は、水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアルコキシ基、置換基を有してもよいアリール基を表す。〕
（２）前記架橋樹脂は、少なくとも３官能以上のラジカル重合性モノマー、光重合開始剤が光エネルギーもしくは電子線照射により硬化したものであることを特徴とする前記（１）に記載の電子写真感光体。
（３）前記一般式（１）で示される化合物由来の部位を架橋表面層中に１０重量％以上７０重量％以下含むことを特徴とする前記（１）または（２）に記載の電子写真感光体。
（４）前記一般式（１）で示される化合物は、波長３５０ｎｍ以上に吸収がないものであることを特徴とする前記（１）乃至（３）のいずれかに記載の電子写真感光体。
（５）該表面層中の式（１）で示される化合物由来の部位と架橋樹脂とが化学結合していることを特徴とする前記（１）乃至（４）のいずれかに記載の電子写真感光体。
（６）前記（１）乃至（５）のいずれかに記載の電子写真感光体と、帯電手段、現像手段、転写手段、クリーニング手段および除電手段よりなる群から選ばれた少なくとも一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ。
（７）前記（１）乃至（５）のいずれかに記載の電子写真感光体を有することを特徴とする画像形成装置。
（８）前記（１）乃至（５）のいずれかに記載の電子写真感光体を用いて、少なくとも帯電、画像露光、現像、転写を繰り返し行なうことを特徴とする画像形成方法。

[In general formula (1), R3, R4, R8, R9, R13, and R14 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and all of them are not hydrogen atoms. . R1, R2, R5, R6, R7, R10, R11, R12, and R15 are each a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. An aralkyl group which may have a group, an aryl group which may have a substituent, an alkylene group which may have a substituent, a cyano group, a nitro group, or —OCO═CH ₂ R16, , A hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and an aryl group which may have a substituent. ]
(2) The electrophotographic photosensitive member as described in (1) above, wherein the cross-linked resin is a radically polymerizable monomer having at least trifunctionality or a photopolymerization initiator cured by light energy or electron beam irradiation. body.
(3) The electrophotographic photosensitive member as described in (1) or (2) above, wherein a site derived from the compound represented by the general formula (1) is contained in the crosslinked surface layer in an amount of 10% by weight to 70% by weight. body.
(4) The electrophotographic photosensitive member according to any one of (1) to (3), wherein the compound represented by the general formula (1) has no absorption at a wavelength of 350 nm or more.
(5) The electrophotography according to any one of (1) to (4) above, wherein a site derived from the compound represented by formula (1) in the surface layer and the crosslinked resin are chemically bonded. Photoconductor.
(6) The electrophotographic photosensitive member according to any one of (1) to (5), and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. What is claimed is: 1. A process cartridge for an image forming apparatus, wherein the process cartridge is detachable from a main body of the image forming apparatus.
(7) An image forming apparatus comprising the electrophotographic photosensitive member according to any one of (1) to (5).
(8) An image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of (1) to (5).

As will be understood from the following detailed and specific description, a triphenylamine structure by irradiation with light energy is introduced into at least one phenyl group of the triphenylamine structure by introducing a substituent at an ortho position with respect to N. It is possible to prevent a change in the structure of the compound having, and to form a highly durable crosslinked surface layer without inhibiting the development of the three-dimensional network structure of the crosslinked resin.
Furthermore, when one or two phenyl groups bonded to N have one substituent at the ortho position, contact between the phenyl groups of adjacent compounds having a triphenylamine structure is improved and high. It has a charge transport capability, can prevent residual potential rise and chargeability reduction, and one of the other phenyl groups has a polymerizable functional group so that it can be incorporated into a three-dimensional network structure to improve mechanical durability. To do.

It is a figure which shows an example of the laminated constitution of the electrophotographic photoreceptor of this invention. It is a figure which shows the other example of a laminated constitution of the electrophotographic photoreceptor of this invention. It is a figure which shows an example of the image forming apparatus of this invention. It is a figure which shows the other example of the image forming apparatus of this invention. It is a figure which shows an example of the process cartridge of this invention.

<About electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention will be described in detail.
The electrophotographic photoreceptor of the present invention has at least a photosensitive layer and a crosslinked surface layer on a support, and may have other undercoat layers and the like as necessary.

<About the cross-linked surface layer>
The cross-linked surface layer is provided in order to protect the photosensitive layer due to abrasion or scratches due to mechanical hazards in the actual photoconductor.
The crosslinked surface layer of the photoreceptor of the present invention has at least a site derived from the compound represented by the crosslinked resin and the general formula (1).

〔一般式（１）中、Ｒ３、Ｒ４、Ｒ８、Ｒ９、Ｒ１３、Ｒ１４は、それぞれ水素原子、ハロゲン原子、アルキル基、アルコキシ基、又は、アリール基を表し、すべてが水素原子であることはない。Ｒ１、Ｒ２、Ｒ５、Ｒ６、Ｒ７、Ｒ１０、Ｒ１１、Ｒ１２、Ｒ１５は、それぞれ、水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアルコキシ基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、置換基を有してもよいアルキレン基、シアノ基、ニトロ基、又は−ＯＣＯ＝ＣＨ_２Ｒ１６を表し、Ｒ１６は、水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアルコキシ基、置換基を有してもよいアリール基を表す。〕

[In general formula (1), R3, R4, R8, R9, R13, and R14 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and all of them are not hydrogen atoms. . R1, R2, R5, R6, R7, R10, R11, R12, and R15 are each a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. An aralkyl group which may have a group, an aryl group which may have a substituent, an alkylene group which may have a substituent, a cyano group, a nitro group, or —OCO═CH ₂ R16, , A hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and an aryl group which may have a substituent. ]

  The compound represented by the general formula (1) has a charge transport function and is effectively used as a charge transport material for an electrophotographic photosensitive member. The compound represented by the general formula (1) is It is very easy to cause a chemical reaction by irradiation with heat energy, light energy, electron beam, etc., and in particular, the ortho-position with respect to N, that is, the reaction at the R3, R4, R8, R9, R13, and R14 sites of the general formula (1) When all of these are hydrogen atoms, the ortho-positions are bonded to each other to form a carbazole structure, and the physical properties are likely to change. When the material having such a change in physical properties is contained in the film, the charge transport ability in the film is changed, which causes an increase in charge trapping.

When the compound having a triphenylamine structure has a phenyl group having a substituent at the ortho position relative to N, binding between the ortho positions of adjacent phenyl groups in the compound having a triphenylamine structure is inhibited, It is difficult to cause a chemical reaction, the charge transport ability does not change, the charge trap is difficult to increase, and the ortho-position substituent exists between two phenyl groups, so that the substituent attached to the para-position or meta-position As compared with the above, there is little influence on the bulkiness of the whole compound, and the development of the three-dimensional network structure of the crosslinked resin described later is not hindered.
Furthermore, if the substituent at the ortho position is an electron donating group, the charge density of the phenyl group is increased and the charge transporting ability is improved. However, when the number of substituents attached to the phenyl group is increased, the adjacent triphenylamine structure is formed. It is preferable that the phenyl group having a substituent at the ortho position does not have any other substituent, since the degree of contact between the charge transporting ability structural portions of the compound having the compound decreases and may become a charge trap. It is preferable that 1 or 2 of the phenyl group to be bonded has one substituent at the ortho position.

Moreover, it is preferable that the compound which has a triphenylamine structure has a functional group in which one other phenyl group different from the phenyl group which had the substituent in ortho position can react with crosslinked resin. By having a functional group capable of reacting, it is incorporated into the three-dimensional network structure of the crosslinked resin by heat energy, light energy, electron beam irradiation, etc., and mechanical durability is improved.
Examples of the functional group capable of reaction include acryloyl group and methacryloyl group, and acryloyl group is particularly preferable.

  Furthermore, the compound having a triphenylamine structure is preferably one having no absorption at a wavelength of 350 nm or more. When the compound having a triphenylamine structure does not absorb light energy for crosslinking, the light absorption of the photopolymerization initiator is not hindered, and the crosslinking reaction can proceed efficiently. Since crosslinking is performed not only from the surface but also from the inside of the crosslinked surface layer, a uniform crosslinked surface layer having a high crosslinking density can be formed, and mechanical durability can be improved.

A method for measuring the absorption spectrum at this time will be described.
First, a compound having a triphenylamine structure represented by the general formula (1), 3 mg is dissolved in 1000 mL of tetrahydrofuran, and the solution is measured by a solution method using an ultraviolet-visible near-infrared spectrophotometer UV-3600 manufactured by Shimadzu Corporation. For 350 nm light, it is assumed that an absorbance of less than 0.1 is not absorbed, and an absorbance of 0.1 or more is absorbed.

Although the example of the compound which has the triphenylamine structure shown by General formula (1) contained in a bridge | crosslinking surface layer is shown below, it is not limited to these compounds.

The content of the compound having a triphenylamine structure depends on the structure and the kind of the crosslinked resin, but is 10 to 70% by weight, preferably 30 to 30% in the entire crosslinked surface layer from the balance between the crosslinking density and the charge transport ability. 60% by weight.

Next, the radical polymerizable monomer constituting the crosslinked surface layer will be described.
The radical polymerizable monomer is crosslinked by light energy and electron beam irradiation. For example, trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate. Acrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO Modified glycerol triacrylate, PO modified glycerol triac Rate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate Alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, 2,2,5,5, -tetrahydroxymethylcyclopentanone tetraacrylate, etc. These may be used alone or in combination of two or more.

The radical polymerizable monomer is preferably crosslinked by light energy or electron beam irradiation. Light energy or an electron beam is transmitted to the inside of the crosslinked surface layer, and a crosslinking reaction occurs also from the inside of the crosslinked surface layer, so that a crosslinked surface layer having high hardness and high elasticity can be formed.

The crosslinked surface layer may preferably contain a photopolymerization initiator in order to efficiently perform a crosslinking reaction by light energy and electron beam irradiation.
Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.
These polymerization initiators may be used alone or in combination of two or more. Content of a polymerization initiator is 0.5 to 40 weight% with respect to the monomer which has radical polymerizability, Preferably it is 1 to 20 weight%.

In addition, a filler material may be added to the crosslinked surface layer for the purpose of improving wear resistance.
Examples of organic filler materials include fluororesin powders such as polytetrafluoroethylene, silicone resin powders, a-carbon powders, etc., and inorganic filler materials include metal powders such as copper, tin, aluminum, and indium. Silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, tin oxide doped with antimony, metal oxides such as tin-doped indium oxide, and inorganic materials such as potassium titanate .
In particular, it is advantageous to use an inorganic material among them from the viewpoint of the hardness of the filler. Metal oxides are particularly good, and aluminum oxide can be used effectively.

The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the crosslinked surface layer. When the average primary particle size of the filler is 0.01 μm or less, it causes a decrease in wear resistance, a decrease in dispersibility, etc., and when it is 0.5 μm or more, the sedimentation property of the filler is promoted in the dispersion liquid. In addition, toner filming may occur.
The higher the filler material concentration in the cross-linked surface layer, the better the wear resistance. However, if it is too high, the residual potential increases, the write light transmittance of the protective layer decreases, and side effects may occur. . Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

The crosslinked surface layer coating solution comprises a crosslinked resin and a compound having a triphenylamine structure represented by the general formula (1), tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclopentanone, anisole, It can be formed by dispersing with a ball mill, attritor, sand mill, bead mill or the like using a solvent such as xylene, methyl ethyl ketone, acetone, ethyl acetate or butyl acetate, and diluting the dispersion appropriately. The cross-linked surface layer coating solution can be applied by dip coating, spray coating, bead coating, ring coating, or the like.
The thickness of the crosslinked surface layer is preferably 1 to 10 μm, and more preferably 3 to 6 μm.

<About photosensitive layer>
Next, the photosensitive layer will be described. The photosensitive layer may have a single photosensitive layer provided with a photosensitive layer having both a charge generation function and a charge transport function as shown in FIG. 1, and a charge generation function as shown in FIG. And a photosensitive layer having a laminate structure in which a charge generation layer having a charge transport layer and a charge transport layer having a charge transport material function are laminated.
Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.

<Photosensitive layer having a laminated structure>
(Charge generation layer)
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.

  Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.

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

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide. These binder resins can be used alone or as a mixture of two or more. In addition to the binder resin described above as a binder resin for the charge generation layer, a polymer charge transport material having a charge transport function, such as an arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, etc. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.

The charge generation layer may contain a low molecular charge transport material.
Low molecular charge transport materials that can be used in the charge generation layer include hole transport materials and electron transport materials.

  Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. As hole transport materials, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls Other known materials such as methane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.

Methods for forming the charge generation layer include a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.
In addition, in order to provide the charge generation layer by the casting method described below, a ball mill, an attritor, a sand mill using the above-mentioned inorganic or organic charge generation material together with a binder resin, if necessary, using the same solvent as the above-mentioned crosslinked surface layer. It can be formed by dispersing with a bead mill or the like and applying the solution after diluting the dispersion appropriately. Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

(About charge transport layer)
The charge transport layer is a layer mainly composed of a charge transport material having a charge transport function, and a binder resin can be used in combination as necessary.

  As the charge transport material, the electron transport material, hole transport material and polymer charge transport material described in the charge generation layer can be used. By using a polymer charge transport material, dissolution of the charge transport layer during coating of the crosslinked surface layer can be reduced, which is particularly useful.

  Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

  The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it can be used alone or in combination with a binder resin.

  As the solvent used for coating the charge transport layer, the same solvent as the above-mentioned crosslinked surface layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. The charge transport layer can be formed by the same coating method as that for the charge generation layer.

If necessary, a plasticizer and a leveling agent can be added.
As a plasticizer that can be used in combination with the lower layer portion of the charge transport layer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 100 parts by weight of the binder resin. On the other hand, about 0 to 30 parts by weight is appropriate.
Leveling agents that can be used in combination with the charge transport layer include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. The amount used is a binder resin. About 0 to 1 part by weight is appropriate for 100 parts by weight.

  The thickness of the charge transport layer is suitably about 5 to 40 μm, preferably about 10 to 30 μm.

<Single photosensitive layer>
A photosensitive layer having a single layer structure is a layer having both a charge generation function and a charge transport function.
It can be formed by dissolving or dispersing the above-described charge generating material having a charge generating function, charge transporting material having a charge transport function, and a binder resin in an appropriate solvent, and applying and drying the solution. Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the charge generation material dispersion method, the charge generation material, the charge transport material, the plasticizer, and the leveling agent may be the same as those already described in the charge generation layer and the charge transport layer. As the binder resin, in addition to the binder resin previously mentioned in the section of the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. In addition, a polymer charge transporting material can be used, which is useful in that the mixing of the photosensitive layer composition into the crosslinked surface layer can be reduced. The film thickness of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.
The

  The charge generation material contained in the photosensitive layer having a single layer structure is preferably 1 to 30% by weight based on the total amount of the photosensitive layer, and the binder resin contained in the lower layer portion of the photosensitive layer is 20 to 80% by weight of the total amount. The transport material is preferably used in an amount of 10 to 70 parts by weight.

<About the undercoat layer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin.

Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.
These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

<About conductive support>
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. After metal oxide is deposited or sputtered, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. Pipes that have been subjected to surface treatment such as cutting, super-finishing, and polishing can be used. Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

In addition, those obtained by dispersing and coating conductive powder in an appropriate binder resin on the support can also be used as the conductive support of the present invention.
Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Can be mentioned. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support of the present invention.

<Image forming apparatus>
Next, the electrophotographic method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 3 is a schematic diagram for explaining the electrophotographic process and the image forming apparatus of the present invention, and the following examples also belong to the category of the present invention.
The photoconductor (10) rotates in the direction of the arrow in FIG. 3, and a charging member (11), an image exposure member (12), a developing member (13), and a transfer member (16) are arranged around the photoconductor (10). ), A cleaning member (17), a charge removal member (18), and the like are disposed. The cleaning member (17) and the charge removal member (18) may be omitted.
The operation of the image forming apparatus is basically as follows. The charging member (11) charges the surface of the photoreceptor (10) almost uniformly. Subsequently, image light writing corresponding to the input signal is performed by the image exposure member (12) to form an electrostatic latent image. Next, the electrostatic latent image is developed by the developing member (13), and a toner image is formed on the surface of the photoreceptor. The formed toner image is transferred onto the transfer paper (15) sent to the transfer site by the transport roller (14) by the transfer member. This toner image is fixed on the transfer paper by a fixing device (not shown). Part of the toner that has not been transferred to the transfer paper is cleaned by the cleaning member (17). Next, the charge remaining on the photoreceptor is neutralized by the neutralizing member (18), and the process proceeds to the next cycle.

  Although the photoconductor (10) in FIG. 3 has a drum shape, it may be a sheet or an endless belt. As the charging member (11) and the transfer member (16), in addition to corotron, scorotron, solid state charger (solid state charger), a roller-shaped charging member or a brush-shaped charging member is used. Are all usable.

Further, light sources such as the image exposure member (12) and the charge removal member (18) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), electroluminescence (EL). ) And other luminescent materials can be used. Among these, a semiconductor laser (LD) and a light emitting diode (LED) are mainly used.

Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

The light source irradiates the photoconductor (10) with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process using light irradiation together. However, the exposure of the photoconductor (10) in the static elimination process has a large influence of fatigue on the photoconductor (10), and may cause a decrease in charge and an increase in residual potential.
Therefore, there is a case where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which may be effective from the viewpoint of enhancing the durability of the photoreceptor.

When the electrophotographic photosensitive member (10) is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

Among the contaminants that adhere to the surface of the photoconductor, discharge substances generated by charging and external additives contained in the toner are easy to pick up the effects of humidity and cause abnormal images. Paper powder is one of the causative substances, and when they adhere to the photoreceptor, abnormal images are more likely to occur, as well as a tendency to reduce wear resistance and cause uneven wear. Is seen. Therefore, it is more preferable from the viewpoint of high image quality that the photoconductor and the paper are not in direct contact for the above reason.

The toner developed on the photoconductor (10) by the developing member (13) is transferred to the transfer paper (15), but not all is transferred, and the toner remaining on the photoconductor (10). Also occurs. Such toner is removed from the photoreceptor (10) by the cleaning member (17).
As the cleaning member, a known member such as a cleaning blade or a cleaning brush is used. Moreover, both may be used together.

The photoconductor according to the present invention can be applied to a small-diameter photoconductor because high photosensitivity and high stability are realized. Therefore, as an image forming apparatus or method for using the above photoreceptor more effectively, each developing unit corresponding to a plurality of colors of toner is provided with a plurality of corresponding photoreceptors, thereby performing parallel processing. It is very effectively used in a so-called tandem type image forming apparatus.

The tandem image forming apparatus includes at least four color toners of yellow (C), magenta (M), cyan (C), and black (K) required for full-color printing and a developing unit that holds them. Further, by providing at least four photoconductors corresponding to them, full-color printing can be performed at an extremely high speed as compared with a conventional image forming apparatus capable of full-color printing.

FIG. 4 is a schematic diagram for explaining the tandem-type full-color electrophotographic apparatus of the present invention, and the following modifications also belong to the category of the present invention.
In FIG. 4, photoconductors (10C (cyan)), (10M (magenta)), (10Y (yellow)), and (10K (black)) are drum-like photoconductors (10), and these photoconductors. (10C, 10M, 10Y, 10K) rotate in the direction of the arrow in the figure, around which at least the charging members (11C, 11M, 11Y, 11K), the developing members (13C, 13M, 13Y, 13K), Cleaning members (17C, 17M, 17Y, 17K) are arranged.

From the surface side of the photoreceptor (10) between the charging member (11C, 11M, 11Y, 11K) and the developing member (13C, 13M, 13Y, 13K), laser light (12C, 12M, 12Y, 12K) is irradiated, and electrostatic latent images are formed on the photoconductors (10C, 10M, 10Y, 10K).
Then, four image forming elements (20C, 20M, 20Y, 20K) centering on such photoconductors (10C, 10M, 10Y, 10K) are along the intermediate transfer belt (25) which is a transfer material conveying means. Are juxtaposed.

The intermediate transfer belt (19) is between the developing member (13C, 13M, 13Y, 13K) of each image forming unit (20C, 20M, 20Y, 20K) and the cleaning member (17C, 17M, 17Y, 17K). A transfer member (16C) for applying a transfer bias to the surface (rear surface) which is in contact with the photoconductor (10C, 10M, 10Y, 10K) and contacts the back side of the intermediate transfer belt (19) on the photoconductor (10) side. , 16M, 16Y, 16K). Each of the image forming elements (20C, 20M, 20Y, 20K) is different in toner color inside the developing device, and the other components have the same configuration.

In the color electrophotographic apparatus having the configuration shown in FIG. 4, the image forming operation is performed as follows. First, in each of the image forming elements (20C, 20M, 20Y, and 20K), the charging member (11C, 11M, and 11Y) in which the photosensitive member (10C, 10M, 10Y, and 10K) rotates along with the photosensitive member (10). , 11K) and then corresponding to the image of each color to be created by laser light (12C, 12M, 12Y, 12K) with an exposure unit (not shown) arranged outside the photoreceptor (10). An electrostatic latent image is formed.

Next, the latent image is developed by a developing member (13C, 13M, 13Y, 13K) to form a toner image. The developing members (13C, 13M, 13Y, and 13K) are developing members that perform development with toners of C (cyan), M (magenta), Y (yellow), and K (black), respectively. 10M, 10Y, and 10K) are overlaid on the transfer belt (19).

The transfer paper (15) is sent out from the tray by the paper supply roller (21), temporarily stopped by the pair of registration rollers (22), and sent to the transfer member (23) in synchronization with the image formation on the photosensitive member. It is done. The toner image held on the transfer belt (19) is transferred onto the transfer paper (15) by an electric field formed by a potential difference between the transfer bias applied to the transfer member (23) and the transfer belt (19). . The toner image transferred onto the transfer paper is conveyed, the toner is fixed onto the transfer paper by the fixing member (24), and is discharged to a paper discharge unit (not shown). Further, residual toner that is not transferred by the transfer unit and remains on the photosensitive members (10C, 10M, 10Y, and 10K) is collected by cleaning members (17C, 17M, 17Y, and 17K) provided in the respective units. The

The intermediate transfer method as shown in FIG. 4 is particularly effective for an image forming apparatus capable of full-color printing. By forming a plurality of toner images once on an intermediate transfer body and transferring them to paper at once, It is easy to control the color shift and is effective for high image quality.
The intermediate transfer member includes various materials or shapes such as a drum shape and a belt shape. In the present invention, any conventionally known intermediate transfer member can be used. It is effective and useful for achieving high quality or high image quality.

In the example of FIG. 4, the image forming elements are arranged in the order of C (cyan), M (magenta), Y (yellow), and K (black) from the upstream side to the downstream side in the transfer paper conveyance direction. However, it is not limited to this order, and the color order is arbitrarily set. Further, when a black-only document is created, it is particularly effective to use the present invention to provide a mechanism that stops the image forming elements (20C, 20M, 20Y) other than black.

The above-described tandem image forming apparatus can transfer a plurality of toner images at a time, so that high-speed full-color printing is realized.
However, since at least four photoconductors are required, an increase in the size of the apparatus is unavoidable, and depending on the amount of toner used, there is a difference in the wear amount of each photoconductor, thereby reproducing the color. However, when the electrophotographic photosensitive member having a highly durable cross-linked surface layer of the present invention is used, the diameter of the photosensitive member is reduced. Since it has a high charge transport capability and the effects of residual potential rise and sensitivity deterioration are reduced, the residual potential and sensitivity can be repeated even if the four photoconductors are used in different amounts. A difference in usage time is small, and it is possible to obtain a full-color image having excellent color reproducibility even after repeated use over a long period of time.

The image forming apparatus as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.

<Process cartridge>
An example of the process cartridge of the present invention is shown in FIG. The process cartridge contains a photoreceptor (10), and in addition, a charging member (11), an image exposure member (12), a developing member (13), a transfer member (16), a cleaning member (17), and a charge eliminating member. 1 is an apparatus (part) that is detachable from the main body of the image forming apparatus.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Note that “parts” used in the examples all represent parts by weight.

An undercoat layer was formed on an Al support (outer diameter 30 mmφ) by dipping so that the film thickness after drying was 3.5 μm.
・ Coating liquid for undercoat layer 6 parts alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
40 parts of titanium oxide
(CR-EL: Ishihara Sangyo)
50 parts of methyl ethyl ketone On this undercoat layer, a charge generation layer coating solution containing a bisazo pigment having the following structure was dip coated and dried by heating to form a 0.2 μm thick charge generation layer.
-Coating solution for charge generation layer 2.5 parts of bisazo pigment with the following structure

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ製） ０．５部
シクロヘキサノン ２００部
メチルエチルケトン ８０部

Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 part Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

On this charge generation layer, a charge transport layer coating solution having the following structure was dip-coated and heat-dried to obtain a charge transport layer having a thickness of 22 μm.
・ Coating solution for charge transport layer 10 parts of bisphenol Z type polycarbonate 10 parts of low molecular charge transport material with the following structure

テトラヒドロフラン ８０部
１％シリコーンオイルのテトラヒドロフラン溶液 ０．２部
（ＫＦ５０−１００ＣＳ、信越化学工業製）

Tetrahydrofuran 80 parts 1% silicone oil tetrahydrofuran solution 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

Spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following constitution, light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , irradiation time: 160 seconds, and further 130 ° C. Was dried for 30 minutes to provide a 4.0 μm cross-linked surface layer to obtain an electrophotographic photoreceptor of the present invention.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound having the following structure (this compound has absorption at 350 nm) 10 parts

光重合開始剤 （イルガキュア２９５９、チバ・スペシャルティ・ケミカルズ製）１部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 2959, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）１部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア９０７、チバ・スペシャルティ・ケミカルズ製）１部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）１部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound having the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア３６９、チバ・スペシャルティ・ケミカルズ製）１部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.
Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.
Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）１部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

(Comparative Example 1)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound having the following structure (this compound has absorption at 350 nm) 10 parts

光重合開始剤 （イルガキュア２９５９、チバ・スペシャルティ・ケミカルズ製）１部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 2959, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

(Comparative Example 2)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
10 parts of a compound having the following structure (this compound has no absorption at 350 nm or more)

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

(Comparative Example 3)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

(Comparative Example 4)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア９０７、チバ・スペシャルティ・ケミカルズ製） １部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

(Comparative Example 5)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

(Comparative Example 6)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound having the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア３６９、チバ・スペシャルティ・ケミカルズ製） １部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals) 1 part Tetrahydrofuran 100 parts

(Comparative Example 7)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

(Comparative Example 8)
A photoconductor was prepared in the same manner as in Example 1 except that the crosslinked surface layer coating solution had the following constitution.

Crosslinked surface layer coating solution / radical polymerizable monomer (trimethylolpropane acrylate) 10 parts (KAYARAD TMPTA, Nippon Kayaku)
Compound of the following structure (this compound has no absorption at 350 nm or more) 10 parts

光重合開始剤 （イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製） １部
アルミナ微粒子（ＡＡ０２：住友化学製） ５部
テトラヒドロフラン １００部

Photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) 1 part Alumina fine particles (AA02: manufactured by Sumitomo Chemical) 5 parts Tetrahydrofuran 100 parts

(Comparative Example 9)
A photoconductor was prepared in the same manner as in Example 1 except that the cross-linked surface layer was not provided and the charge transport layer was 28 μm.

Example and Comparative Example Evaluation of Photoconductors (Actual Machine Passing Test)
The produced electrophotographic photosensitive member was subjected to 200,000 actual paper feeding tests (A4, MyPaper made by NBS Ricoh) using Ricoh's Ipsio Color CX9000, and subjected to wear characteristics, in-machine potential evaluation, and image evaluation. The results are shown in Tables 1, 2, and 3.
The abrasion amount was evaluated by measuring the film thickness at 20 points on the photoconductor with an eddy current film thickness meter (Fisherscope MMS) and determining the film thickness reduction from the initial stage.

*比較例９は摩耗が非常に大きいことから、１０万枚で通紙試験を終了した。

* In Comparative Example 9, the wear was very large, so the paper passing test was completed with 100,000 sheets.

*VD ： 帯電電位、VL ： 露光部電位

* VD: Charging potential, VL: Exposure area potential

*ドット再現性 ・・・ ドット画像を出力し、目視で評価 ○：良好、△；ドットチリが見られた、△：ドットチリが認められた。
*濃度低下 ： ○：良好、△：やや低下みられた、×：明らかな濃度低下が見られた

* Dot reproducibility: A dot image was output and visually evaluated. ○: Good, Δ: Dot dust was observed, Δ: Dot dust was observed.
* Decrease in density: ○: Good, △: Slightly reduced, X: Clearly reduced density

10, 10Y, 10M, 10C, 10K Photoconductor 11, 11Y, 11M, 11C, 11K Charging member 12, 12Y, 12M, 12C, 13K Image exposure member 13, 13Y, 13M, 13C, 13K Developing member 14 Transport roller 15 Transfer Paper 16, 16Y, 16M, 16C, 16K Transfer member 17, 17Y, 17M, 17C, 17K Cleaning member 18 Static elimination member 19 Intermediate transfer body 20Y, 20M, 20C, 20K Image forming element 21 Paper feed roller 22 Registration roller 23 Transfer member (Secondary transfer member)
24 Fixing member

Japanese Patent No. 3194392 Japanese Patent No. 4145820 Japanese Patent No. 3244951

Claims (8)

It has at least a photosensitive layer and a crosslinked surface layer on the support, and the crosslinked surface layer has at least a site derived from a compound having a triphenylamine structure represented by general formula (1) with a crosslinked resin. An electrophotographic photoreceptor characterized by the above.

[In general formula (1), R3, R4, R8, R9, R13, and R14 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or an aryl group, and all of them are not hydrogen atoms. . R1, R2, R5, R6, R7, R10, R11, R12, and R15 are each a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. An aralkyl group which may have a group, an aryl group which may have a substituent, an alkylene group which may have a substituent, a cyano group, a nitro group, or —OCO═CH ₂ R16, , A hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, and an aryl group which may have a substituent. ]
2. The electrophotographic photosensitive member according to claim 1, wherein the cross-linked resin is obtained by curing at least a trifunctional or higher-functional radical polymerizable monomer and a photopolymerization initiator by light energy or electron beam irradiation.
3. The electrophotographic photosensitive member according to claim 1, wherein a site derived from the compound represented by the general formula (1) is contained in the crosslinked surface layer in an amount of 10 wt% to 70 wt%.
The electrophotographic photoreceptor according to any one of claims 1 to 3, wherein the compound represented by the general formula (1) has no absorption at a wavelength of 350 nm or more.

The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein a site derived from the compound represented by the formula (1) in the surface layer and the crosslinked resin are chemically bonded.
An electrophotographic photosensitive member according to any one of claims 1 to 5, and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, a cleaning means and a charge eliminating means, A process cartridge for an image forming apparatus, wherein the process cartridge is removable from a main body of the forming apparatus.
An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.
  6. An image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to claim 1.

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