JP4194996B2 - Electrophotographic photosensitive member, image forming method using the same, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Description

  The present invention uses a surface layer having high wear resistance, smooth film surface properties, and almost no variation in electrical characteristics due to the environment, so that it has excellent durability and stable electrical characteristics and high quality. The present invention relates to an electrophotographic photosensitive member that realizes image formation over a long period of time. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using the long-life, high-performance photoconductor.

  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.

On the other hand, the diameter of the photoconductor has recently been reduced due to the downsizing of the image forming apparatus, and the high speed of the machine and the maintenance-free movement have been added to increase the durability of the photoconductor. From this point of view, organophotoreceptors are generally soft because the surface layer is mainly composed of low-molecular charge transport materials and inert polymers, and when used repeatedly in electrophotographic processes, they are mechanically driven by development systems and cleaning systems. There is a drawback that wear is likely to occur due to a typical load. In addition, due to the demand for higher image quality, the rubber hardness of the cleaning blade and the contact pressure must be increased for the purpose of improving the cleaning property as the particle size of the toner particles is reduced. This also promotes the wear of the photoreceptor. It is a factor. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.
Therefore, it is indispensable to reduce the amount of wear as described above in order to increase the durability of the organic photoreceptor, and an organic photoreceptor having a good surface property is required in order to impart excellent cleaning properties and transferability. These are the most pressing issues in the field.

  Techniques for improving the abrasion resistance of the photosensitive layer include (1) using a curable binder for the surface layer (see Patent Document 1), and (2) using a polymer type charge transport material (Patent Document 2). And (3) those obtained by dispersing an inorganic filler in the surface layer (see Patent Document 3). Among these techniques, those using the curable binder (1) have poor compatibility with the charge transport material, and the residual potential increases due to impurities such as polymerization initiators and unreacted residues, resulting in a decrease in image density. Tends to occur. In addition, (2) using a polymer type charge transport material and (3) dispersed inorganic filler are required for organic photoreceptors, although they can improve wear resistance to some extent. The durability has not been fully satisfied. Further, in the case where the inorganic filler (3) is dispersed, the residual potential increases due to traps present on the surface of the inorganic filler, and the image density tends to decrease. These technologies (1), (2), and (3) are sufficient to satisfy the overall durability including the electrical durability and mechanical durability required for the organic photoreceptor. Has not reached.

  Furthermore, a photoreceptor containing a polyfunctional curable acrylate monomer in order to improve the abrasion resistance and scratch resistance of (1) is also known (see Patent Document 4). However, in this photoreceptor, although there is a description that the polyfunctional curable acrylate monomer is contained in the protective layer provided on the photosensitive layer, the protective layer may contain a charge transport material. However, when the surface layer contains a low-molecular charge transporting substance, there is a problem of compatibility with the cured product. In some cases, the molecular charge transport material is precipitated and cracks are generated, and the mechanical strength is also lowered. There is also a description that a polycarbonate resin is contained for improving compatibility, but the content of the curable acrylic monomer is reduced, and as a result, sufficient wear resistance cannot be achieved. In addition, regarding a photoconductor that does not include a charge transport material in the surface layer, there is a description that the surface layer is a thin film in order to lower the potential of the exposed portion. However, the lifetime of the photoconductor is short because the film thickness is thin. In addition, the environmental stability of the charging potential and the exposure portion potential is poor, and the value fluctuates greatly due to the influence of the greenhouse environment, and the current situation is that a sufficient value has not been maintained.

  As an alternative anti-wear technique for photosensitive layers, a charge transport layer formed by using a coating solution comprising a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin is used. The binder resin has a carbon-carbon double bond and is reactive with the charge transport material, and the binder resin has a double bond. And non-reactive ones are included. This photoconductor is remarkably compatible with wear resistance and good electrical properties. However, when a non-reactive binder resin is used, the binder resin, the monomer, and the charge transport material are used. The compatibility with the cured product produced by this reaction was poor, and surface irregularities were generated during cross-linking from layer separation, and a tendency to cause poor cleaning was observed. Further, as described above, in this case, the binder resin prevents the curing of the monomer, and what is specifically described as the monomer used in the photoreceptor is a bifunctional one. The monomer has a small number of functional groups and a sufficient crosslinking density cannot be obtained, and it has not yet been satisfactory in terms of wear resistance. Further, even when a reactive binder is used, due to the low number of functional groups contained in the monomer and the binder resin, it is difficult to achieve both the binding amount and the crosslinking density of the charge transport material, and the electrical characteristics and The abrasion resistance was not sufficient.

A photosensitive layer containing a compound obtained by curing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is also known (see Patent Document 6). However, in this photosensitive layer, the bulky hole transporting compound has two or more chain-polymerizable functional groups, so that distortion occurs in the cured product, resulting in high internal stress, resulting in rough surface layers and cracks over time. It may be easy to do and does not have sufficient durability.
For the above reasons, it cannot be said that a photoreceptor having a cross-linked photosensitive layer obtained by chemically bonding the charge transporting structure in these prior arts has sufficient comprehensive characteristics at present.
JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent No. 3262488 Japanese Patent No. 3194392 JP 2000-66425 A

  An object of the present invention is to use a surface layer having a smooth surface property with high wear resistance and almost no variation in electrical properties due to the environment, thereby achieving excellent durability as well as highly stable electrical properties and high quality. It is to provide an electrophotographic photosensitive member that realizes image formation over a long period of time, and to provide an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using the long-life, high-performance photosensitive member. That is.

  In the electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the present inventors provide a radical polymerizable monomer in which the surface layer of the photosensitive layer does not have at least a charge transporting structure represented by the following general formula (A) It was discovered that the above-mentioned problems can be achieved by curing a radically polymerizable compound having a monofunctional charge transporting structure, and the present invention has been achieved.

（式（Ａ）中、Ｒ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６の内３つ以上５つ以下は下記一般式（Ｂ）

を示し、Ｒ_７７は単結合、アルキレン基、アルキレンエーテル基、アルキレンオキシカルボニル基を示し、Ｒ_７８は水素およびメチル基を示し、一般式（Ｂ）で表される官能基は同一でも異なっていてもよい。またＲ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６の内一般式（Ｂ）で表される官能基以外の官能基は、炭素数６以下の置換基を有してもよいアルキル基を含む官能基であり、それぞれ同一でも異なっていてもよい。） That is, the above-mentioned problem is (1) an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support of the present invention, wherein the surface layer of the photosensitive layer is at least a charge transporting structure represented by the following general formula (A): An electrophotographic photoreceptor characterized by being formed by curing a radically polymerizable monomer having no cation and a radically polymerizable compound having a monofunctional charge transporting structure;

(In formula (A), 3 or more and 5 or less of R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ are represented by the following general formula (B)

R ₇₇ represents a single bond, an alkylene group, an alkylene ether group or an alkyleneoxycarbonyl group, R ₇₈ represents hydrogen and a methyl group, and the functional groups represented by the general formula (B) are the same or different. Also good. Moreover, functional groups other than the functional group represented by the general formula (B) among R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , and R ₇₆ may have a substituent having 6 or less carbon atoms. A functional group containing an alkyl group, which may be the same or different. )

(2) The electrophotographic photosensitive material according to (1), wherein the functional group of the monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is an acryloyloxy group or a methacryloyloxy group. body,
(3) The electron according to (1) or (2), wherein the charge transport structure of the monofunctional radically polymerizable compound having a charge transport structure used in the surface layer is a triarylamine structure. Photographic photoreceptor,

（式（１）及び（２）中、Ｒ_１は水素原子、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ラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７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ラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、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ラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル２価基、アルキレンオキシカルボニル２価基を表わす。ｍ、ｎは０〜３の整数を表わす。） (4) The monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is one or more of the following general formula (1) or (2): 3) The electrophotographic photosensitive member according to any one of

(In Formulas (1) and (2), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₇ (R ₇ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group), a carbonyl halide group or CONR ₈ R ₉ (R ₈ and R ₉ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or Represents an aryl group which may have a substituent, and may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same or different which may be _.Ar 3, A ₄ represents a substituted or unsubstituted aryl group, which may be identical or different .X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene Represents an ether group, an oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group; Represents an integer of 3.)

（式（３）中、ｏ、ｐ、ｑはそれぞれ０又は１の整数、Ｒaは水素原子、メチル基を表わし、Ｒｂ、Ｒｃは水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚaは単結合、メチレン基、エチレン基、

を表す。） (5) Any of the above (1) to (4), wherein the monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is one or more of the following general formula (3): The electrophotographic photosensitive member according to claim 1,

(In the formula (3), o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. And s and t each represent an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. )

(6) The electrophotographic photosensitive member according to any one of (1) to (5), wherein the curing means for the surface layer is heating or light energy irradiation means,
(7) The electrophotographic photosensitive film as described in any one of (1) to (6) above, wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a crosslinked surface layer from the support side. body,
It is solved by.

The problem is
(8) An image forming method characterized in that at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of (1) to (7) above. Is done.
The problem is
(9) An image forming apparatus comprising the electrophotographic photosensitive member according to any one of (1) to (7).
The problem is
(10) At least one means selected from the group consisting of the electrophotographic photosensitive member according to any one of (1) to (7) above, a charging means, a developing means, a transfer means, a cleaning means, and a static elimination means. And a process cartridge for an image forming apparatus that is detachable from the main body of the image forming apparatus.

  In the present invention, a compound having a reactive functional group as a resin component for forming a crosslinked layer on the surface layer of the photosensitive layer, more specifically, radical polymerization not having a charge transporting structure represented by the general formula (A) By mixing a functional monomer and a monofunctional radically polymerizable monomer having a charge transporting structure, and simultaneously carrying out a polymerization reaction to obtain a cured crosslinked resin layer, it has high wear resistance and good electrical characteristics. A photoconductor excellent in environmental resistance over a long period of time was realized. Therefore, by using this photoreceptor, it is possible to provide a high-performance and highly reliable image forming process, an image forming apparatus, and a process cartridge for an image forming apparatus that can provide a higher quality image over a long period of time.

（式（Ａ）中、Ｒ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６の内３つ以上５つ以下は下記一般式（Ｂ）

を示し、Ｒ_７７は単結合、アルキレン基、アルキレンエーテル基、アルキレンオキシカルボニル基を示し、Ｒ_７８は水素およびメチル基を示し、一般式（Ｂ）で表される官能基は同一でも異なっていてもよい。またＲ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６の内一般式（Ｂ）で表される官能基以外の官能基は、炭素数６以下の置換基を有してもよいアルキル基を含む官能基であり、それぞれ同一でも異なっていてもよい。）
で表される電荷輸送性構造を有しないラジカル重合性モノマーを用いる。 The present invention will be described in detail below.
The present invention is based on the following basic idea. The photoreceptor of the present invention has a surface layer,

(In formula (A), 3 or more and 5 or less of R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ are represented by the following general formula (B)

R ₇₇ represents a single bond, an alkylene group, an alkylene ether group or an alkyleneoxycarbonyl group, R ₇₈ represents hydrogen and a methyl group, and the functional groups represented by the general formula (B) are the same or different. Also good. Moreover, functional groups other than the functional group represented by the general formula (B) among R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , and R ₇₆ may have a substituent having 6 or less carbon atoms. A functional group containing an alkyl group, which may be the same or different. )
A radically polymerizable monomer having no charge transporting structure represented by

In the general formula (A), the carbon number of the alkyl group which may have a substituent having 6 or less carbon atoms in R _{71 to} R ₇₆ is 6 from the viewpoint of the amount of the radical polymerizable functional group per molecule. Hereinafter, it is preferably 4 or less, more preferably 2 or less, and by increasing the amount of the radical polymerizable functional group per molecule, high-density crosslinking is realized, and high wear resistance can be obtained.
Further, the number of carbon atoms in the alkyl portion of R ₇₇ alkylene group, alkylene ether group or alkyleneoxycarbonyl group is 15 or less, preferably 10 or less, from the viewpoint of securing the same amount of radically polymerizable functional group per molecule as above. More preferably, it is 5 or less.

  By using a radically polymerizable monomer having no charge transporting structure represented by the general formula (A), a three-dimensional network structure is developed, and a high-hardness crosslinked surface layer having a very high crosslinking density is obtained. Abrasion is achieved. In addition, when only a monomer having a small number of radically polymerizable functional groups is used, the crosslinking density in the crosslinked surface layer is dilute, and a dramatic improvement in wear resistance cannot be achieved. When a polymer material is contained in the cross-linked surface layer, the development of the three-dimensional network structure is inhibited and the degree of cross-linking is lowered, so that sufficient wear resistance cannot be obtained as compared with the present invention. Further, the polymer material and radical polymerizable composition contained therein (radical polymerizable monomer having no charge transporting structure represented by formula (A), monofunctional radical polymerizable compound having a charge transporting structure) The compatibility with the cured product resulting from this reaction is poor, local wear occurs from the phase separation, and it appears as a scratch on the surface.

  In addition, in the formation of the crosslinked surface layer of the present invention, a monofunctional radically polymerizable compound having a charge transporting structure is added to the radically polymerizable monomer having no charge transporting structure represented by the general formula (A). These were simultaneously hardened in a short time to form a high-hardness cross-linking bond, and an improvement in durability was achieved. Furthermore, it became possible to form a smooth surface layer by improving the curing rate, and it became possible to maintain a good cleaning property for a long period of time. Furthermore, it cures a radically polymerizable monomer having a charge transporting structure and a radically polymerizable monomer having a charge transporting structure and a radically polymerizable monomer represented by the general formula (A), which has many reactive functional groups and a high curing rate. This makes it possible to form a uniform crosslinked film with little distortion in the crosslinked layer. As a result, the unreacted portion of the charge transport material is reduced in the crosslinked surface layer, and the homogeneity inside the crosslinked film is greatly improved. The In addition, since a monofunctional radically polymerizable compound having a charge transporting structure is incorporated in the cross-linked layer, stable electric characteristics are exhibited over a long period of time. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the cross-linked surface layer The mechanical strength also decreases. In addition, when a bifunctional or higher functional charge transporting compound is used, it is fixed in the crosslinked structure by a plurality of bonds. However, since the charge transporting structure is very bulky, distortion occurs in the cured resin, and the inside of the crosslinked surface layer. Stress increases and cracks and scratches occur frequently due to carrier adhesion. In addition, since the intermediate structure (cation radical) at the time of charge transport cannot be stably maintained because a plurality of bonds are fixed in the crosslinked structure, the sensitivity is lowered due to charge trapping and the residual potential is increased. Such deterioration of the electrical characteristics appears as an image such as a decrease in image density and thinning of characters.

  Furthermore, the radically polymerizable monomer represented by the general formula (A) has an alkylene group that is a nonpolar group in the molecular structure, and as a result, the affinity with a polar solvent (such as alcohol or water) is reduced, Furthermore, it shows strong resistance to acids and alkalis. Therefore, it is possible to suppress the hygroscopic property of the cured product in the crosslinked surface layer, and it is possible to suppress deformation due to moisture absorption and deterioration of electrical characteristics. That is, by using the radically polymerizable monomer represented by the general formula (A), the margin for environmental fluctuations considered to be derived from polar groups typified by high temperature and high humidity and low temperature and low humidity is greatly improved.

  Therefore, in the present invention, a compound having a reactive functional group as a resin component constituting the cross-linked surface layer, more specifically, a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a charge By simultaneously polymerizing monofunctional radically polymerizable compounds having a transporting structure to form a cross-linked surface layer, it is possible to maintain high image quality over a long period of time while improving wear resistance, and also against environmental fluctuations It has become possible to realize an electrophotographic photosensitive member that can achieve a significant improvement in margin.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
The radically polymerizable monomer having no charge transporting structure used in the present invention is represented by the general formula (A). For example, a monomer having 3 to 5 radically polymerizable functional groups of acryloyloxy group or methacryloyloxy group, etc. Can be mentioned.
A compound having 3 to 5 acryloyloxy groups is subjected to an ester reaction or a transesterification reaction using, for example, a compound having 3 to 5 hydroxyl groups in the molecule and acrylic acid (salt), acrylic acid halide, or acrylic ester. Can be obtained. Moreover, the compound which has 3-5 methacryloyloxy groups can be obtained similarly. Further, the radical polymerizable functional groups in the monomer having 3 to 5 radical polymerizable functional groups may be the same or different.

  Examples of the radical polymerizable monomer having no charge transporting structure represented by the general formula (A) include the following, but are not limited to these compounds. Alkyl-modified dipentaerythritol pentaacrylate (KAYARAD D-310, manufactured by Nippon Kayaku), alkyl-modified dipentaerythritol tetraacrylate (KAYARAD D-320, manufactured by Nippon Kayaku), alkyl-modified dipentaerythritol triacrylate (KAYARAD D-330) , Made by Nippon Kayaku).

  Moreover, the component ratio of the radically polymerizable monomer having no charge transporting structure represented by the general formula (A) used for the crosslinked surface layer is 5 to 80% by weight, preferably 10 to 70%, based on the total amount of the crosslinked surface layer. % By weight. When the monomer component is less than 5% by weight, the three-dimensional cross-linking density of the cross-linked surface layer is small, and a drastic improvement in wear resistance is not achieved as compared with the case of using a conventional thermoplastic binder resin. On the other hand, if it exceeds 80% by weight, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated.

  The monofunctional radically polymerizable compound having a charge transporting structure used in the present invention is a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, A compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having a radical polymerizable functional group. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization. Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.

(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formulas.
CH ₂ = CH—X ₁ −... Formula 10
(In the formula, X ₁ is an arylene group such as a phenylene group or a naphthylene group which may have a substituent, an alkenylene group which may have a substituent, a —CO— group, a —COO— group. , —CON (R ₁₀ ) — group (R ₁₀ represents an alkyl group such as hydrogen, methyl group or ethyl group, an aralkyl group such as benzyl group, naphthylmethyl group or phenethyl group, or an aryl group such as phenyl group or naphthyl group. Or represents an —S— group.)
Specific examples of these functional groups include vinyl group, styryl group, 2-methyl-1,3-butadienyl group, vinylcarbonyl group, acryloyloxy group, acryloylamide group, vinylthioether group and the like.

(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following formulas.
_{CH 2 = C (Y) -X} 2 - ···· formula 11
(In the formula, Y is an aryl group such as an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group. Group, halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ₁₁ group (R ₁₁ is a hydrogen atom, an alkyl such as an optionally substituted methyl group or ethyl group) Group, an aralkyl group such as benzyl which may have a substituent, a phenethyl group or the like, an aryl group such as a phenyl group or a naphthyl group which may have a substituent, or -CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ is a hydrogen atom, which may have a substituent an alkyl group such as methyl group and ethyl group, which may have a substituent group benzyl group, naphthylmethyl group, or Ara such phenethyl group, Kill group or substituent a phenyl group which may have a represents an aryl group such as phenyl or naphthyl, which may be the same or different from each other.) Further, X ₂ is the same as X ₁ in the formula 10 substituents and a single bond, an alkylene group. However, Y, at least one oxycarbonyl group in X _2, a cyano group, an alkenylene group, and an aromatic ring.)
Specific examples of these functional groups include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ and Y include, for example, halogen groups, nitro groups, cyano groups, methyl groups, ethyl groups and other alkyl groups, methoxy groups, ethoxy groups, and the like. And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

（式（１）及び（２）中、Ｒ_１は水素原子、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ラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７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ラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、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ラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル２価基、アルキレンオキシカルボニル２価基を表わす。ｍ、ｎは０〜３の整数を表わす。） Among these radical polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. In addition, a triarylamine structure is highly effective as a charge transporting structure. Furthermore, when a compound represented by the structure of the following general formula (1) or (2) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.

(In Formulas (1) and (2), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₇ (R ₇ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group), a carbonyl halide group or CONR ₈ R ₉ (R ₈ and R ₉ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or Represents an aryl group which may have a substituent, and may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same or different which may be _.Ar 3, A ₄ represents a substituted or unsubstituted aryl group, which may be identical or different .X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene Represents an ether group, an oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group; Represents an integer of 3.)

Specific examples of general formulas (1) and (2) are shown below.
In the general formulas (1) and (2), in the substituent of R ₁ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.
Of the substituents for R ₁ , particularly preferred are a hydrogen atom and a methyl group.

Ar ₃ and Ar ₄ are substituted or unsubstituted aryl groups, and examples of the aryl group include condensed polycyclic hydrocarbon groups, non-fused cyclic hydrocarbon groups, and heterocyclic groups.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.

Examples of the non-fused cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether and diphenyl sulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne, Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring assemblies such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.
Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) Alkyl groups, preferably C ₁ -C _12, especially C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkyl groups, further including fluorine atoms , a hydroxyl group, a cyano _group, an alkoxy group of C 1 -C _4, a phenyl group or a halogen _atom, which may have a phenyl group substituted by an alkoxy group C 1 -C ₄ alkyl or _C 1 -C ₄ Good. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.
(3) An alkoxy group (—OR ₂ ), and R ₂ represents the alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) An aryloxy group, and examples of the aryl group include a phenyl group and a naphthyl group. It _may contain an alkoxy group having C 1 -C _4, alkyl group, or a halogen atom C 1 -C ₄ as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group, and specific examples include methylthio group, ethylthio group, phenylthio group, p-methylphenylthio group and the like.

（式中、Ｒ_３及びＲ_４は各々独立に水素原子、前記（２）で定義したアルキル基、またはアリール基を表わす。アリール基としては、例えばフェニル基、ビフェニル基又はナフチル基が挙げられ、これらはＣ_１〜Ｃ_４のアルコキシ基、Ｃ_１〜Ｃ_４のアルキル基またはハロゲン原子を置換基として含有してもよい。Ｒ_３及びＲ_４は共同で環を形成してもよい。）
具体的には、アミノ基、ジエチルアミノ基、Ｎ−メチル−Ｎ−フェニルアミノ基、Ｎ，Ｎ−ジフェニルアミノ基、Ｎ，Ｎ−ジ（トリール）アミノ基、ジベンジルアミノ基、ピペリジノ基、モルホリノ基、ピロリジノ基等が挙げられる。 (6)

(In the formula, R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these _C 1 -C ₄ alkoxy _groups, C 1 -C good .R ₃ and _{R 4} may contain as alkyl group or a halogen atom substituents ₄ may be linked to form a ring.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.

(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

The arylene group represented by Ar ₁ and Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .
X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.

The substituted or unsubstituted alkylene group is a C ₁ -C ₁₂ , preferably C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkylene group. a fluorine atom, a hydroxyl group, a cyano _group, an alkoxy group of C 1 -C _4, a phenyl group or a halogen _atom, a phenyl group substituted with an alkyl group or a _C 1 -C ₄ alkoxy group C 1 -C ₄ It may be. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

The substituted or unsubstituted cycloalkylene _group, a cyclic alkylene group of C 5 -C _7, these are the cyclic alkylene group fluorine atom, a hydroxyl _group, an alkyl group of C 1 -C _4, a C 1 -C ₄ It may have an alkoxy group. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
The substituted or unsubstituted alkylene ether group represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the alkylene group of the alkylene ether group is a hydroxyl group, a methyl group, an ethyl group And the like.

で表わされ、Ｒ_５は水素、アルキル基（前記（２）で定義されるアルキル基と同じ）、アリール基（前記Ａｒ_３、Ａｒ_４で表わされるアリール基と同じ）、aは１または２、ｂは１〜３を表わす。
前記Ｚは置換もしくは未置換のアルキレン基、置換もしくは無置換のアルキレンエーテル２価基、アルキレンオキシカルボニル２価基を表わす。
置換もしくは未置換のアルキレン基としては、前記Ｘのアルキレン基と同様なものが挙げられる。
置換もしくは無置換のアルキレンエーテル２価基としては、前記Ｘのアルキレンエーテル基の２価基が挙げられる。アルキレンオキシカルボニル２価基としては、カプロラクトン変性２価基が挙げられる。 The vinylene group is

R ₅ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2 , B represents 1-3.
Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether divalent group include the divalent group of the alkylene ether group of X. Examples of the alkyleneoxycarbonyl divalent group include a caprolactone-modified divalent group.

（式（３）中、ｏ、ｐ、ｑはそれぞれ０又は１の整数、Ｒaは水素原子、メチル基を表わし、Ｒｂ、Ｒｃは水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚaは単結合、メチレン基、エチレン基、

を表わす。）
上記一般式で表わされる化合物としては、Ｒｂ、Ｒｃの置換基として、特にメチル基、エチル基である化合物が好ましい。 Further, the radical polymerizable compound having a monofunctional charge transport structure of the present invention is more preferably a compound having a structure of the following general formula (3).

(In the formula (3), o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. And s and t each represent an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. )
As the compound represented by the above general formula, a compound having a methyl group or an ethyl group as a substituent for Rb and Rc is particularly preferable.

  The radically polymerizable compound having a monofunctional charge transport structure represented by the general formulas (1) and (2), particularly (3) used in the present invention is polymerized with the carbon-carbon double bond open on both sides. Therefore, in a polymer that does not become a terminal structure but is incorporated in a chain polymer and crosslinked by polymerization with a radical polymerizable monomer having no charge transport structure represented by the general formula (A), It exists in the main chain of the molecule and in the cross-linked chain between the main chain and main chain (this cross-linked chain includes an inter-molecular cross-linked chain between one polymer and another polymer, (There is an intramolecular cross-linked chain that crosslinks a part of the main chain that is folded in and another part derived from the polymerized monomer at a position away from the main chain in the main chain), but exists in the main chain Hangs from the chain part, whether or not The rearylamine structure has at least three aryl groups arranged in a radial direction from the nitrogen atom and is bulky, but is not directly bonded to the chain part but is suspended from the chain part via a carbonyl group or the like. Therefore, since these triarylamine structures can be arranged in the polymer in a space that is reasonably adjacent to each other because they are fixed in a state where there is flexibility in steric positioning, there is little structural distortion in the molecule, and When the surface layer of the electrophotographic photosensitive member is used, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport path can be adopted.

Specific examples of the radical polymerizable compound having a monofunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

  Further, the monofunctional radically polymerizable compound having a charge transporting structure used in the present invention is important for imparting the charge transport performance of the crosslinked surface layer, and this component is 20 to 80% by weight based on the total amount of the crosslinked surface layer. %, Preferably 30 to 70% by weight. When this component is less than 20% by weight, the charge transport performance of the crosslinked surface layer cannot be maintained sufficiently, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential appears with repeated use. On the other hand, if it exceeds 80% by weight, the content of the radically polymerizable monomer not having the charge transporting structure represented by the general formula (A) is lowered, the crosslinking density is lowered, and high wear resistance is not exhibited. The required electrical characteristics and wear resistance differ depending on the process to be used, so it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  The surface layer of the present invention is a crosslinked surface layer obtained by simultaneously curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. However, radically polymerizable monomers and radically polymerizable oligomers may be used together for the purpose of imparting functions such as viscosity adjustment during coating of the surface layer, stress adjustment of the cross-linked surface layer, low surface free energy and friction coefficient reduction. it can. Known radical polymerizable monomers and oligomers can be used.

Examples of the radical polymerizable monomer include the following, but are not limited to these compounds.
That is, examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and 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 triacrylate, Lith (acryloxyethyl) isocyanurate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, 2,2,5,5, -tetrahydroxymethylcyclopentanone tetraacrylate, 2 -Ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol Acrylate, phenoxytetraethylene glycol acrylate, cet Acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, 6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO modified bisphenol A diacrylate, EO modified bisphenol F diacrylate, neopentyl glycol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, caprolactone Examples thereof include modified dipentaerythritol hexaacrylate.

  Examples of the functional monomer include those having a fluorine atom substituted such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, and radical polymerizable functional groups. A reactive additive having a group, for example, a reactive silicone-based additive such as PO-modified-2-neopentylglycol diacrylate can also be used effectively. These functional monomers may be used alone or in combination of two or more. The content of the functional monomer is 0.01 to 30% by weight, preferably 0.05 to 20% by weight, based on the solid content of the coating liquid forming the crosslinked layer.

Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers.
However, if one or two functional radical polymerizable monomers or radical polymerizable oligomers are contained in a large amount, the three-dimensional cross-linking density of the cross-linked surface layer is substantially reduced, resulting in a decrease in wear resistance. For this reason, the content of these monomers and oligomers is limited to 150 parts by weight or less, preferably 100 parts by weight or less with respect to 100 parts by weight of the radically polymerizable monomer having no charge transporting structure represented by the general formula (A). The

The surface layer of the present invention is a crosslinked surface obtained by simultaneously curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. Although it is a layer, a polymerization initiator may be used in the crosslinked surface layer in order to efficiently advance the crosslinking reaction as necessary.
Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( Peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, peroxide initiators such as lauroyl peroxide, azobisisobutylnitrile, azobiscyclohexanecarbonitrile Azo initiators such as methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid.

  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. The content of the polymerization initiator is 0.5 to 40 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total content having radical polymerizability.

The surface layer of the present invention is a crosslinked surface layer obtained by simultaneously curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. However, in addition to this, filler fine particles can be contained for the purpose of improving wear resistance.
The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of the light transmittance and wear resistance of the surface layer. When the average primary particle size of the filler is 0.01 μm or less, it causes a decrease in dispersibility and the effect of improving the abrasion resistance is not sufficiently exhibited. When the average primary particle size is 0.5 μm or more, the filler is contained in the dispersion. There is a possibility that the settling property of the toner is promoted and toner filming may occur. The higher the filler material concentration in the surface layer is, the higher the wear resistance is, and the better. However, if it is too high, the residual potential increases and the writing light transmittance of the surface layer decreases, which may cause side effects. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

  Furthermore, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the fillers. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem. As the surface treatment agent, all conventionally used surface treatment agents can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable.

  About surface treatment amount, although it changes with average primary particle diameters of the filler to be used, 3-30 wt% is suitable with respect to filler weight, and 5-20 wt% is more preferable. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These filler materials may be used alone or in combination of two or more.

  Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement) and leveling agents as necessary. Known additives can be used as these additives, and plasticizers that are used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20% by weight or less, preferably 10% or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating liquid. 3% by weight or less is appropriate.

  In the composition contained in the crosslinked surface layer coating solution, it is possible to contain a binder resin as long as the smoothness, electrical characteristics, or durability of the photoreceptor surface is not impaired. However, when a polymer material such as a binder resin is included in the coating liquid, it is in phase with the polymer formed by the curing reaction of the radical polymerizable composition (radical polymerizable monomer and radical polymerizable compound having a charge transporting structure). Phase separation occurs due to poor solubility, and the surface of the crosslinked surface layer becomes uneven. Therefore, it is preferable not to use a binder resin.

  The crosslinked surface layer of the present invention is coated with a coating solution containing a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radical polymerizable compound having a charge transporting structure, It is formed by curing. When the radically polymerizable monomer is a liquid, such a coating liquid can be applied by dissolving other components in the liquid, but if necessary, it is diluted with a solvent and applied. Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. Ethers such as dichloromethane, halogens such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolves such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.

In the present invention, after applying such a coating solution, energy is applied from the outside and cured to form a crosslinked surface layer. The external energy used at this time includes heat, light, and radiation. The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves. The heating temperature is preferably 100 ° C. or more and 170 ° C. or less, and if it is less than 100 ° C., the reaction rate is slow and the reaction is not completely completed. At a temperature higher than 170 ° C., the reaction proceeds non-uniformly and a large strain is generated in the crosslinked surface layer. In order to proceed the curing reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 100 ° C. and then heating to 100 ° C. or more. As the energy of light, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly have an emission wavelength in ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radically polymerizable substances and photopolymerization initiators. Is possible. Irradiation light amount is 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, it takes time for the curing reaction is less than 50 mW / cm ^2. If it is higher than 1000 mW / cm ^2, the progress of the reaction becomes non-uniform and the cross-linked surface layer becomes very rough. Examples of radiation energy include those using electron beams. Among these energies, those using heat and light energy are useful because of easy reaction rate control and simple apparatus.

Since the film thickness of the crosslinked surface layer of the present invention varies depending on the layer structure of the photoreceptor in which the crosslinked surface layer is used, it is described in accordance with the following description of the layer structure.
<About the layer structure of the electrophotographic photoreceptor>
The electrophotographic photosensitive member used in the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an electrophotographic photosensitive member of the present invention, which is a single-layered photosensitive member in which a photosensitive layer having a charge generating function and a charge transporting function is provided on a conductive support. FIG. 1A shows the case where the cross-linked surface layer is the entire photosensitive layer, and FIG. 1-B shows the case where the cross-linked surface layer is the surface portion of the photosensitive layer.
FIG. 2 shows a photoreceptor having a laminated structure in which a charge generation layer having a charge generation function and a charge transport layer having a charge transport material function are laminated on a conductive support. FIG. 2-A shows the case where the cross-linked surface layer is the entire charge transport layer, and FIG. 2-B shows the case where the cross-linked surface layer is the surface portion of the charge transport layer.

<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-vinyl carbazole, 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.

<About photosensitive layer>
Next, the photosensitive layer will be described. The photosensitive layer may have a laminated structure or a single layer structure.
In the case of a laminated structure, the photosensitive layer is composed of a charge generation layer having a charge generation function and a charge transport layer having a charge transport function. In the case of a single layer structure, the photosensitive layer is a layer having a charge generation function and a charge transport function at the same time.
Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.

<Photosensitive layer with a laminated structure>
(1) 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 a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having 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, Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.

  Specific examples of the former include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559, Japanese Unexamined Patent Publication Nos. 04-011627, 04-175337, 04-183719, 04-2225014, 04-230767, 04-320420, 05 -232727, JP-A 05-310904, JP-A 06-234836, JP-A 06-234837, JP-A 06-234838, JP-A 06-234839, JP-A 06-234840. No. 1, JP-A 06-234841, JP-A 06-239049, Japanese Unexamined Patent Publication Nos. 06-236050, 06-236051, 06-295077, 07-0756374, 08-176293, 08-208820, 08 No. -21640, JP 08-253568, JP 08-269183, JP 09-062019, JP 09-043883, JP 09-71642, JP 09-87376. JP-A 09-104746, JP-A 09-110974, JP-A 09-110976, JP-A 09-157378, JP-A 09-221544, JP-A 09-227669. JP 09-235367 A, JP 09-241369 A Charge transporting polymer materials described in JP 09-268226 A, JP 09-272735 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Can be mentioned.

  Specific examples of the latter include polysilylene polymers described in, for example, JP-A No. 63-285552, JP-A No. 05-19497, JP-A No. 05-70595, JP-A No. 10-73944, and the like. Illustrated.

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, bromanyl, 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 a charge generation layer by the casting method described later, if necessary, the inorganic or organic charge generation material together with a binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. Can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. . 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.

(2) Charge Transport Layer The charge transport layer is a layer having a charge transport function, and the crosslinked surface layer having the charge transport structure of the present invention is useful as a charge transport layer. When the cross-linked surface layer is the entire charge transport layer, the radical polymerizable composition of the present invention (charge transport property represented by the general formula (A)) is formed on the charge generation layer as described in the above cross-linked surface layer preparation method. Apply a coating solution containing a radically polymerizable monomer having no structure and a monofunctional radically polymerizable compound having a charge transporting structure (the same applies hereinafter), and if necessary, after drying, start a curing reaction by external energy. A crosslinked surface layer is formed. At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If it is thinner than 10 μm, a sufficient charging potential cannot be maintained, and if it is thicker than 30 μm, peeling from the lower layer tends to occur due to volume shrinkage during curing.
In addition, when the cross-linked surface layer is formed on the surface portion of the charge transport layer and the charge transport layer has a laminated structure, the lower layer portion of the charge transport layer uses a charge transport material having a charge transport function and a binder resin as an appropriate solvent. It dissolves or disperses, and this is formed by applying and drying on the charge generation layer, on which a coating liquid containing the radical polymerizable composition of the present invention is applied and crosslinked and cured by external energy.

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. In particular, the use of a polymer charge transport material is particularly useful because it has an effect of reducing the solubility of the lower layer during coating of the surface layer.
As the binder resin, 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-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And 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 lower layer portion of the charge transport layer, the same solvent as that for the charge generation 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. In addition, the same coating method as that for the charge generation layer can be used to form the lower layer portion of the charge transport 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.
As a leveling agent that can be used in combination with the lower layer portion of the charge transport layer, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used. About 0 to 1 part by weight is appropriate for 100 parts by weight of the binder resin.
The thickness of the lower layer portion of the charge transport layer is appropriately about 5 to 40 μm, preferably about 10 to 30 μm.

  When the cross-linked surface layer is the surface portion of the charge transport layer, as described in the above cross-linked surface layer preparation method, the coating liquid containing the radical polymerizable composition of the present invention on the lower layer portion of the charge transport layer After the coating and drying as necessary, the curing reaction is initiated by external energy such as heat or light to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. If the thickness is less than 1 μm, the durability varies due to uneven film thickness. If the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased, and the reproducibility of the image is reduced due to the diffusion of charges.

<Single photosensitive layer>
The photosensitive layer having a single layer structure is a layer having a charge generation function and a charge transport function at the same time, and the crosslinked surface layer having the charge transport structure of the present invention contains a charge generation material having a charge generation function, thereby providing a single layer structure. It is useful as a photosensitive layer. As described in the method for forming a charge generation layer, the charge generation material is dispersed together with a coating solution containing a radical polymerizable composition, applied onto a conductive support, dried as necessary, and externally applied. The curing reaction is initiated by energy, and a crosslinked surface layer is formed. In addition, you may add the liquid in which the charge generation material was previously disperse | distributed with the solvent to this coating material for bridge | crosslinking surface layers. At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If the thickness is less than 10 μm, a sufficient charging potential cannot be maintained. If the thickness is more than 30 μm, peeling from the conductive substrate or the undercoat layer tends to occur due to volume shrinkage during curing.

  Further, when the crosslinked surface layer is a surface portion of a photosensitive layer having a single layer structure, the lower layer portion of the photosensitive layer is composed of a charge generating material having a charge generating function, a charge transporting material having a charge transport function, and a binder resin in an appropriate solvent. It can be formed by dissolving or dispersing in, coating and drying. 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, the above-described polymer charge transport materials can also be used, which is useful in that contamination of the lower photosensitive layer composition into the crosslinked surface layer can be reduced. The thickness of the lower layer portion of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.

When the cross-linked surface layer is the surface portion of the photosensitive layer having a single layer structure, the coating solution containing the radical polymerizable composition of the present invention and the charge generating material is applied onto the lower layer portion of the photosensitive layer as described above. If necessary, after drying, it is cured by external energy such as heat or light to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness.
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 intermediate layer>
In the photoreceptor of the present invention, when the crosslinked surface layer is a surface portion of the photosensitive layer, an intermediate layer can be provided between the crosslinked surface layer and the lower photosensitive layer. This intermediate layer prevents inhibition of the curing reaction and unevenness of the crosslinked surface layer caused by mixing of the lower photosensitive layer composition in the outermost surface layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the lower photosensitive layer and the surface cross-linked layer.
In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method is employed as described above. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

<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.

<Addition of antioxidant to each layer>
Further, in the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, in particular, a crosslinked surface layer, a charge generation layer, a charge transport layer, an undercoat layer, an intermediate layer, etc. Antioxidants can be added to each layer.
The following are mentioned as antioxidant which can be used for this invention.
(1) Phenol compounds 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di -T-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-t -Butylphenol), 4,4'-thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2-Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene , Tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butyl) Phenyl) butyric acid] cricol ester, tocopherols and the like.

(2) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(3) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.
(4) Organic sulfur compounds Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(5) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.
These compounds are known as antioxidants such as rubbers, plastics and fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant in the present invention is 0.01 to 10% by weight based on the total weight of the layer to be added.

<Image Forming Method and Apparatus>
Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
The image forming method and the image forming apparatus of the present invention use the photoconductor having the smooth charge transporting cross-linked surface layer of the present invention. For example, at least after the photoconductor is subjected to charging, image exposure, and development processes, image holding is performed. An image forming method and an image forming apparatus including a process of transferring a toner image onto a body (transfer paper), fixing, and cleaning of the surface of a photoreceptor.
In some cases, an image forming method or the like in which an electrostatic latent image is directly transferred to a transfer member and developed does not necessarily have the above-described process arranged on a photosensitive member.
FIG. 3 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger 3 is used as a means for charging the photosensitive member on average. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known system can be used.

Next, the image exposure unit 5 is used to form an electrostatic latent image on the uniformly charged photoreceptor 1. As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be 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.
Next, the developing unit 6 is used to visualize the electrostatic latent image formed on the photoreceptor 1. Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member 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.

Next, a transfer charger 10 is used to transfer the toner image visualized on the photosensitive member onto the transfer member 9. In addition, a pre-transfer charger 7 may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.
Next, a separation charger 11 and a separation claw 12 are used as means for separating the transfer body 9 from the photoreceptor 1. As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger 11, the charging means can be used.

Next, a fur brush 14 and a cleaning blade 15 are used to clean the toner remaining on the photoconductor after transfer. Further, a pre-cleaning charger 13 may be used in order to perform cleaning more efficiently. As other cleaning means, there are a web system, a magnet brush system, and the like, but a single system or a plurality of systems may be used together.
Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, the charge removal lamp 2 and the charge removal charger are used, and the exposure light source and the charging means can be used respectively.
In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.

The present invention is an image forming method and an image forming apparatus using the electrophotographic photoreceptor according to the present invention for such image forming means.
The image forming means may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge and detachable. An example of the process cartridge is shown in FIG.
The process cartridge for an image forming apparatus includes a photosensitive member 101, and further includes at least one of a charging unit 102, a developing unit 104, a transfer unit 106, a cleaning unit 107, and a charge eliminating unit (not shown). An apparatus (part) that is detachable from the forming apparatus main body.

  The image forming process by the apparatus illustrated in FIG. 4 will be described. The photosensitive member 101 is charged in the direction of the arrow while being charged by the charging unit 102 and exposed by the exposure unit 103. A latent image is formed, and the electrostatic latent image is developed with toner by the developing unit 104. The toner development is transferred to the transfer member 105 by the transfer unit 106 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

The present invention provides a process cartridge for an image forming apparatus in which a photoreceptor having a polymer charge transport layer and a crosslinked surface layer is integrated with at least one of charging, developing, transferring, cleaning, and charge eliminating means.
As is apparent from the above description, the electrophotographic photosensitive member of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

<Synthesis Example of Radical Polymerizable Compound Having Monofunctional Charge Transporting Structure>
The radically polymerizable compound having a monofunctional charge transport structure in the present invention is synthesized, for example, by the method described in Japanese Patent No. 3164426. An example of this is shown below.
(1) Synthesis of hydroxy group-substituted triarylamine compound (the following structural formula B) 113.85 g (0.3 mol) of a methoxy group-substituted triarylamine compound (the following structural formula A) and 138 g (0.92 mol) of sodium iodide To this, 240 ml of sulfolane was added and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%) of white crystals of the following structural formula B was obtained.
Melting point: 64.0-66.0 ° C

(2) Triarylamino group-substituted acrylate compound (the above exemplified compound No. 54)
82.9 g (0.227 mol) of the hydroxy group-substituted triarylamine compound (Structural Formula B) obtained in (1) above was dissolved in 400 ml of tetrahydrofuran, and an aqueous sodium hydroxide solution (NaOH: 12.4 g, Water: 100 ml) was added dropwise. The solution was cooled to 5 ° C., and 25.2 g (0.272 mol) of acrylic acid chloride was added dropwise over 40 minutes. Then, it stirred at 5 degreeC for 3 hours, and reaction was complete | finished. The reaction solution was poured into water and extracted with toluene. This extract was repeatedly washed with an aqueous sodium bicarbonate solution and water. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene). N-Hexane was added to the obtained colorless oil to precipitate crystals. In this way, Exemplified Compound No. As a result, 80.73 g (yield = 84.8%) of 54 white crystals were obtained.
Melting point: 117.5-119.0 ° C

  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.

Example 1
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating and dried to obtain a 3.5 μm undercoat layer, 0. A 2 μm charge generation layer and a 23 μm charge transport layer were formed.
◎ Undercoat layer coating liquid ・ Alkyd resin: 6 parts (Beccosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin: 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals)
・ Titanium oxide: 40 parts ・ Methyl ethyl ketone: 50 parts

・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 ◎ Charge generation layer coating solution ・ Bisazo pigment with the following structure: 2.5 parts

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

・テトラヒドロフラン： １００部
・１％シリコーンオイルのテトラヒドロフラン溶液： １部
（ＫＦ５０−１００ＣＳ、信越化学工業製） ◎ Charge transport layer coating solution ・ Bisphenol Z-type polycarbonate: 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals)
-Charge transport material with the following structural formula: 7 parts

Tetrahydrofuran: 100 parts Tetrahydrofuran solution of 1% silicone oil: 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

（式中、Ｒはアルキル基を示す。）
・１官能の電荷輸送性構造を有するラジカル重合性化合物： ９５部
（例示化合物Ｎｏ．５４）
・光重合開始剤： １０部
（１−ヒドロキシ−シクロヘキシル−フェニル−ケトン：
イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）
・テトラヒドロフラン： １２００部 Further, spray coating is performed on the charge transport layer using a crosslinked surface layer coating liquid having the following constitution, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , irradiation time: 20 seconds, Drying was carried out at 130 ° C. for 30 minutes to provide a 4.0 μm crosslinked surface layer, and an electrophotographic photosensitive member was produced.
◎ Crosslinked surface layer coating solution ・ Radically polymerizable monomer having no charge transporting structure: 95 parts (alkyl-modified dipentaerythritol pentaacrylate:
KAYARAD D-310, manufactured by Nippon Kayaku, average molecular weight 580)

(In the formula, R represents an alkyl group.)
-Radical polymerizable compound having a monofunctional charge transporting structure: 95 parts (Exemplary Compound No. 54)
Photopolymerization initiator: 10 parts (1-hydroxy-cyclohexyl-phenyl-ketone:
Irgacure 184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran: 1200 parts

（式中、Ｒはアルキル基を示す。） Example 2
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
Alkyl modified dipentaerythritol tetraacrylate:
KAYARAD D-320, manufactured by Nippon Kayaku, average molecular weight 582

(In the formula, R represents an alkyl group.)

（式中、Ｒはアルキル基を示す。） Example 3
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
Alkyl modified dipentaerythritol tetraacrylate:
KAYARAD D-330, manufactured by Nippon Kayaku, average molecular weight 584

(In the formula, R represents an alkyl group.)

（式中、Ｒはアルキル基を示す。）
（２）トリメチロールプロパントリアクリレート（ＴＭＰＴＡ、東京化成製）：
４７．５部

Example 4
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
-Radical polymerizable monomer having no charge transporting structure: 95 parts (1) Alkyl-modified dipentaerythritol pentaacrylate (KAYARAD D-310, manufactured by Nippon Kayaku, average molecular weight 580): 47.5 parts

(In the formula, R represents an alkyl group.)
(2) Trimethylolpropane triacrylate (TMPTA, manufactured by Tokyo Chemical Industry):
47.5 parts

（式中、Ｒはアルキル基を示す。）
（２）トリメチロールプロパントリアクリレート（ＴＭＰＴＡ、東京化成製）：
４７．５部

Example 5
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
-Radical polymerizable monomer having no charge transporting structure: 95 parts (1) Alkyl-modified dipentaerythritol tetraacrylate (KAYARAD D-320, manufactured by Nippon Kayaku, average molecular weight 582): 47.5 parts

(In the formula, R represents an alkyl group.)
(2) Trimethylolpropane triacrylate (TMPTA, manufactured by Tokyo Chemical Industry):
47.5 parts

（式中、Ｒはアルキル基を示す。）
（２）カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（ＫＡＹＡＲＡＤ ＤＰＣＡ−１２０、日本化薬製）： ４７．５部

Example 6
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
-Radical polymerizable monomer having no charge transporting structure: 95 parts (1) Alkyl-modified dipentaerythritol triacrylate (KAYARAD D-330, Nippon Kayaku, average molecular weight 584): 47.5 parts

(In the formula, R represents an alkyl group.)
(2) Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, manufactured by Nippon Kayaku): 47.5 parts

Example 7
In Example 1, the radical polymerizable compound having a monofunctional charge transporting structure contained in the crosslinked surface layer coating solution was exemplified as Compound No. 1. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the number was changed to 16.

Example 8
In Example 1, the radical polymerizable compound having a monofunctional charge transporting structure contained in the crosslinked surface layer coating solution was exemplified as Compound No. 1. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the number was changed to 24.

（式中、Ｒはアルキル基を示す。）
・１官能の電荷輸送性構造を有するラジカル重合性化合物： ９０部
（例示化合物Ｎｏ．５４）
・光重合開始剤： ２０部
（１−ヒドロキシ−シクロヘキシル−フェニル−ケトン：
イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）
・テトラヒドロフラン： ９０部
・フィラー微粒子： ２０部
（アルミナフィラー：ＡＡ０３、住友化学製） Example 9
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the crosslinked surface layer coating solution in Example 1 was changed to the following.
◎ Crosslinked surface layer coating solution ・ Radically polymerizable monomer having no charge transport structure: 90 parts (alkyl-modified dipentaerythritol hexaacrylate:
KAYARAD D-310, manufactured by Nippon Kayaku, average molecular weight 580)

(In the formula, R represents an alkyl group.)
-Radical polymerizable compound having a monofunctional charge transport structure: 90 parts (Exemplary Compound No. 54)
-Photopolymerization initiator: 20 parts (1-hydroxy-cyclohexyl-phenyl-ketone:
Irgacure 184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran: 90 parts Filler fine particles: 20 parts (Alumina filler: AA03, manufactured by Sumitomo Chemical)

Comparative Example 1
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was not added.

Comparative Example 2
An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was used as the following material.
-Radical polymerizable monomer having no charge transport structure of the following structural formula: 95 parts (Bifunctional acrylate: KAYARAD NPGDA, manufactured by Nippon Kayaku,
(Molecular weight: 212, number of functional groups: bifunctional, molecular weight / number of functional groups = 106)

Comparative Example 3
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having a monofunctional charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was not added.

Comparative Example 4
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having a monofunctional charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials. did.
-Radical polymerizable compound having a charge transport structure of the following structural formula: 95 parts

Comparative Example 5
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having a monofunctional charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials. did.
-Charge transport material of the following structural formula: 10 parts

Comparative Example 6
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the crosslinked surface layer was not provided in Example 1 and the thickness of the charge transport layer was 27 μm.

（但しa＝５．５、ｂ＝０．５である。） Comparative Example 7
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
-Radical polymerizable monomer having no charge transporting structure: 95 parts (Dipentaerythritol hexaacrylate:
KAYARAD DPHA (Nippon Kayaku)

(However, a = 5.5 and b = 0.5.)

（但しa＝５．５、ｂ＝０．５である。） Comparative Example 8
An electrophotographic photoreceptor was prepared in the same manner as in Example 9 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 9 was changed to the following. .
-Radical polymerizable monomer having no charge transporting structure: 95 parts (Dipentaerythritol hexaacrylate:
KAYARAD DPHA (Nippon Kayaku)

(However, a = 5.5 and b = 0.5.)

  The electrophotographic photosensitive member produced as described above is mounted on an electrophotographic process cartridge, and the grid voltage is set to 1000 (−) using a copying machine in which the exposure light source of Ricoh's imgio MF 8570 is modified to 655 nm at room temperature and humidity. V), and at this time, the bright portion potential when 10 sheets of A4 were output by full-surface light irradiation was obtained as an initial value. Furthermore, a continuous paper endurance test was conducted for a total of 500,000 sheets continuously, and the amount of photoconductor wear, the in-machine potential, and the output image were evaluated. Further, as a surface property evaluation of the prepared photoreceptor, a ten-point average roughness (Rz) was measured using a surface roughness profile measuring machine Surfcom 1400D manufactured by Tokyo Seimitsu. The results are shown in Table 3. For Examples 1, 2, 4 and Comparative Examples 4, 7, and 8, a total of 50,000 similar durability tests were conducted in a high temperature and high humidity environment of 30 ° C. and 90% humidity, and the in-machine potential and output image were evaluated. Went. Each result is shown in Table 4.

As is clear from the results in Table 3, in Comparative Examples 1 to 6, it was impossible to achieve both improvement of wear resistance over a long period of time and maintenance of high-quality images.
In Comparative Examples 7 and 8, good results were obtained from the results in Table 3, but from the results in Table 4, it can be seen that high-quality images cannot be obtained in a high-temperature and high-humidity environment.
Further, from Table 4, the crosslinked surface layer is formed by curing a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a radical polymerizable compound having a monofunctional charge transporting structure. It can be seen that the electrophotographic photoreceptor has stable photoreceptor characteristics in a high temperature and high humidity environment. As a result, it can be seen that enhanced resistance to the environment has been realized, and improvement in wear resistance over a long period of time and maintenance of high-quality image output have been achieved.

1 is an example of a cross-sectional view of an electrophotographic photosensitive member of the present invention. It is another example of sectional drawing of the electrophotographic photosensitive member of this invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating an example of a process cartridge for an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger 4 Eraser 5 Image exposure part 6 Developing unit 7 Pre-transfer charger 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Pre-cleaning charger 14 Fur brush 15 Cleaning blade 101 Photoconductor 102 Charging means 103 Exposure 104 Developing means 105 Transfer body 106 Transfer means 107 Cleaning means

Claims (10)

In an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer has at least a radical polymerizable monomer having no charge transporting structure represented by the following general formula (A) and a monofunctional charge. An electrophotographic photoreceptor formed by curing a radically polymerizable compound having a transporting structure.

(In formula (A), 3 or more and 5 or less of R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ are represented by the following general formula (B)

R ₇₇ represents a single bond, an alkylene group, an alkylene ether group or an alkyleneoxycarbonyl group, R ₇₈ represents hydrogen and a methyl group, and the functional groups represented by the general formula (B) are the same or different. Also good. Moreover, functional groups other than the functional group represented by the general formula (B) among R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , and R ₇₆ may have a substituent having 6 or less carbon atoms. A functional group containing an alkyl group, which may be the same or different. )   2. The electrophotographic photoreceptor according to claim 1, wherein the functional group of the monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is an acryloyloxy group or a methacryloyloxy group.   3. The electrophotographic photosensitive member according to claim 1, wherein the monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer has a triarylamine structure. The monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is one or more of the following general formula (1) or (2). The electrophotographic photosensitive member according to Item.

(In Formulas (1) and (2), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₇ (R ₇ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group), a carbonyl halide group or CONR ₈ R ₉ (R ₈ and R ₉ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or Represents an aryl group which may have a substituent, and may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same or different which may be _.Ar 3, A ₄ represents a substituted or unsubstituted aryl group, which may be identical or different .X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene Represents an ether group, an oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group; Represents an integer of 3.) The monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is one or more of the following general formula (3), according to any one of claims 1 to 4. Electrophotographic photoreceptor.

(In the formula (3), o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. And s and t each represent an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. )   6. The electrophotographic photosensitive member according to claim 1, wherein the surface layer curing means is heating or light energy irradiation means.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a crosslinked surface layer from the support side.   An image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to claim 1.   An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.   The electrophotographic photosensitive member according to claim 1, 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 charge eliminating unit. A process cartridge for an image forming apparatus, wherein the process cartridge is removable from the main body of the image forming apparatus.

Images