JP4224008B2 - Electrophotographic photosensitive member, image forming method using the same, image forming apparatus, and image forming process cartridge - Google Patents

Description

  The present invention uses a photosensitive layer having good film surface properties, high wear resistance, and good electrical properties, thereby providing excellent cleaning properties and high durability, and providing stable electrical properties for a long period of time. The present invention relates to an electrophotographic photosensitive member realized over a wide range. 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 cleaning blade is required to increase its rubber hardness and contact pressure 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 above-mentioned wear amount in order to improve the durability of the organic photoreceptor, and in order to impart the ability to prevent toner adhesion to the organic photoreceptor and excellent cleaning and transfer properties, There is a need for lower surface energy of the body, and 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 (for example, see Patent Document 1), and (2) using a polymeric charge transport material (for example, , Patent Document 2), (3) Those in which an inorganic filler is dispersed in the surface layer (for example, see Patent Document 3), and the like. 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 techniques (1) to (3) do not sufficiently satisfy the overall durability including the electrical durability and mechanical durability required for the organic photoreceptor.

Furthermore, a photoreceptor containing a polyfunctional acrylate monomer cured product 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 acrylate monomer cured product 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 transport material, there is a problem of compatibility with the cured product. In some cases, the molecular charge transport material is precipitated and the cloudiness phenomenon occurs, and the mechanical strength is also lowered.
Furthermore, since this photoconductor specifically reacts with a monomer in a state containing a polymer binder, curing does not proceed sufficiently, and there is a problem of compatibility between the cured product and the binder resin. There was a tendency for surface irregularities due to phase separation to cause poor cleaning.

  As a wear resistance technology for a photosensitive layer that replaces these, a charge transport layer formed by using a coating liquid comprising a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin. It is known to provide (for example, refer to Patent Document 5), and the binder resin has a carbon-carbon double bond and is reactive to the charge transfer agent, and the double bond. And those that do not have reactivity. This photoconductor is remarkably compatible with wear resistance and good electrical properties, but when a non-reactive binder resin is used, the binder resin, the monomer and the charge transport agent are used. 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 these points have 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, for example, Patent Document 6).
However, in this photosensitive layer, the bulky hole-transporting compound has two or more chain-polymerizable functional groups, so that the cured product is distorted and the internal stress is increased, resulting in surface layer roughness and cracks over time. In some cases, it does not have sufficient durability.

  On the other hand, various lubrication effects on the outermost surface layer including the charge transport layer as a technology for lowering the surface energy of the organic photoreceptor to impart toner adhesion prevention performance, excellent cleaning properties, and transferability to the organic photoreceptor. There is disclosed a method of containing an additive having the above (see Patent Documents 7 to 13). However, since these photoconductors contain a lubricant in a charge transport layer with insufficient wear resistance, they are initially effective in suppressing adhesion of various substances. Insufficient.

Furthermore, for the purpose of achieving both surface properties and wear resistance of the organic photoreceptor, a method of containing a curable acrylic compound and a reactive acrylic siloxane compound in the protective layer (see Patent Document 14) and a surface layer as a cured film As a lubricant, a method of containing a saturated hydrocarbon compound (see Patent Document 15) is known. The former uses a curable compound that does not have a charge transporting structure, and also uses conductive fine particles of metal oxide to control the resistance value of the protective layer. Decrease in resistance due to the property is unavoidable, which may cause image blur. On the other hand, in the latter case, the hydrocarbon compound as a lubricant is chemically bonded to the photosensitive layer matrix material in the cured film, and the lubricant is incorporated into the photosensitive layer matrix to suppress bleed-out to the surface of the lubricant. However, although it is worth noting that the low surface energy is sustained, the bulky hole transporting compound in the photosensitive layer has two or more chain-polymerizable functional groups. Distortion occurs, surface roughness and cracks with time may occur, and sufficient durability is not achieved. In addition, surface irregularities tend to increase due to distortion in the photosensitive layer. As a result, the contact area between the photosensitive member and its contact member is reduced, and the low surface energy property inherent in the photosensitive member cannot be exhibited. Reality.
As described above, even in a photoreceptor having a crosslinked photosensitive layer chemically bonded to the charge transport structure in these prior arts, it cannot be said that it has sufficient comprehensive properties at present, and a low surface Various ideas for energy conversion have been made, but none of these has yet been satisfactory in terms of durability, electrical characteristics, and other characteristics.

JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent No. 3262488 Japanese Patent No. 3194392 JP 2000-66425 A JP 57-35863 A JP-A 62-75641 JP 63-61256 A JP-A-63-73267 Japanese Patent Application Laid-Open No. 64-35448 JP-A-2-189550 JP-A-11-344818 JP 2000-310872 A JP 2001-166510 A

  An object of the present invention is to use a photosensitive layer having good film surface smoothness, high abrasion resistance, and good electrical characteristics, thereby having excellent cleaning properties and high durability, and further stable electrical properties. It is to provide an electrophotographic photosensitive member that realizes characteristics 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. It is.

  The present invention relates to an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the surface layer of the photosensitive layer has at least a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a charge transporting structure. By having a crosslinked layer obtained by curing a reactive silicone compound having a monofunctional radically polymerizable compound and a radically polymerizable functional group and having a dimethylsiloxane structure as a repeating unit, wear resistance is improved. A long-life, high-performance electrophotographic photosensitive member having high and stable electrical characteristics and good cleaning properties over a long period of time is achieved.

  That is, the above-mentioned problem is (1) “a trifunctional or higher functional radical in which the surface layer of the photosensitive layer has at least a charge transporting structure in an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support. A crosslinked layer obtained by curing a reactive silicone compound having a polymerizable monomer, a monofunctional radically polymerizable compound having a charge transporting structure and a radically polymerizable functional group, and having a dimethylsiloxane structure as a repeating unit The electrophotographic photosensitive member characterized in that the functional group of the reactive silicone compound is an acryloyloxy group or a methacryloyloxy group. (2) Electrophotographic photosensitive member ”, (3)“ The functional group of the reactive silicone compound is an acryloyloxy group ” ) Or the electrophotographic photosensitive member according to item (2) ”, (4)“ the number of acryloyloxy groups of the reactive silicone compound is 2 or more ” (3) The electrophotographic photosensitive member according to any one of items (3) and (5), wherein the molecular weight of the reactive silicone compound is 10,000 or less. The electrophotographic photosensitive member according to any one of the items (1) to (5), wherein the reactive silicone compound has a viscosity at 25 ° C. of 20 Pa · s or less. The electrophotographic photosensitive member according to any one of the above, (7) “the content of the reactive silicone compound is 0.05 to 20% by weight or less based on the solid content of the coating liquid forming the crosslinked layer”. Any of the items (1) to (6) characterized (8) The functional group of the tri- or higher functional radical polymerizable monomer having no charge transporting structure used in the surface layer is an acryloyloxy group or a methacryloyloxy group. The electrophotographic photosensitive member according to any one of (1) to (7) above, (9) “a trifunctional or higher functional radical having no charge transporting structure used for the surface layer” The ratio of molecular weight to the number of functional groups in the polymerizable monomer (molecular weight / number of functional groups) is 250 or less, wherein the electrophotographic photosensitive member according to any one of (1) to (8) above is characterized. (10) “The functional group of the monofunctional radically polymerizable compound having a charge transporting structure used in the surface layer is an acryloyloxy group or a methacryloyloxy group. The electrophotographic photosensitive member according to any one of (1) to (9) above, (11) “Charge transport of a monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer” The electrophotographic photosensitive member according to any one of items (1) to (10), wherein the photoconductive structure is a triarylamine structure ”, (12)“ Charge used in the surface layer ” The monofunctional radically polymerizable compound having a transporting structure is one or more of the following general formulas (1) or (2): The electrophotographic photosensitive member according to the description;

（式中、Ｒ_１は水素原子、ハロゲン原子、置換又は無置換のアルキル基、置換又は無置換のアラルキル基、置換又は無置換のアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換又は無置換のアルキル基、置換又は無置換のアラルキル基又は置換又は無置換のアリール基）、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、置換又は無置換のアルキル基、置換又は無置換のアラルキル基又は置換又は無置換のアリール基を示し、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基、アルキレンオキシカルボニル基を表わす。ｍ、ｎは０〜３の整数を表わす。）」、（１３）「前記表面層に用いられる電荷輸送性構造を有する１官能のラジカル重合性化合物が、下記一般式（３）の一種以上であることを特徴とする前記第（１）項乃至第（１２）項のいずれかに記載の電子写真感光体；

(In the formula, R ₁ is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a cyano group, a nitro group, an alkoxy group, —COOR ₇ ( R ₇ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group), a halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ are hydrogen atoms, A halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, which may be the same or different from each other, and Ar ₁ and Ar ₂ are Represents a substituted or unsubstituted arylene group, which may be the same or different, Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group, and X may be 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. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group or an alkyleneoxycarbonyl group, m and n represent an integer of 0 to 3), ”(13)“ Used in the surface layer. The monofunctional radically polymerizable compound having a charge transporting structure is one or more of the following general formula (3), according to any one of (1) to (12) above: Electrophotographic photoreceptor;

（式中、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、

(Wherein, 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 represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

を表わす。）」、（１４）「前記表面層にフィラー微粒子が分散されたことを特徴とする前記第（１）項乃至第（１３）項のいずれかに記載の電子写真感光体」、（１５）「前記表面層の硬化手段が加熱又は光エネルギー照射手段であることを特徴とする前記第（１）項乃至第（１５）項のいずれかに記載の電子写真感光体」により解決される。
また、上記課題は、本発明の（１６）「前記第（１）項乃至第（１５）項のいずれかに記載の電子写真感光体を用いて、少なくとも帯電、画像露光、現像、転写を繰り返し行なうことを特徴とする画像形成方法」により解決される。
また、上記課題は、本発明の（１７）「前記第（１）項乃至第（１５）項のいずれかに記載の電子写真感光体を有することを特徴とする画像形成装置」により解決される。
また、上記課題は、本発明の（１８）「前記第（１）項乃至第（１５）項のいずれかに記載の電子写真感光体と、帯電手段、現像手段、転写手段、クリーニング手段及び除電手段よりなる群から選ばれた少なくとも一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ」により解決される。

Represents. ) ”, (14)“ Electrophotographic photosensitive member according to any one of items (1) to (13), wherein filler fine particles are dispersed in the surface layer ”, (15)“ The electrophotographic photosensitive member according to any one of (1) to (15), wherein the surface layer curing means is heating or light energy irradiation means.
In addition, the above-described problem is that at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of (16) and (1) to (15) of the present invention. The image forming method is characterized in that it is solved.
In addition, the above-described problem is solved by (17) “an image forming apparatus comprising the electrophotographic photosensitive member according to any one of (1) to (15)” of the present invention. .
Further, the above-mentioned problems are solved by the electrophotographic photosensitive member according to any one of (18) and (1) to (15) of the present invention, a charging unit, a developing unit, a transfer unit, a cleaning unit, and a static elimination unit. An image forming apparatus process cartridge having at least one means selected from the group consisting of means and detachable from the main body of the image forming apparatus is solved.

  In the present invention, an additive having a reactive functional group on the surface layer of the photosensitive layer and a compound having a reactive functional group as a resin component constituting the crosslinked layer, more specifically, no charge transporting structure 3 By mixing a radical polymerizable monomer having a functionality or higher and a monofunctional radical polymerizable monomer having a charge transporting structure and simultaneously carrying out a polymerization reaction to obtain a cured crosslinked resin layer, the wear resistance is high and the A photoreceptor having electrical characteristics and capable of forming a good image over a long period of time can be obtained. 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.

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 uses a tri- or higher functional radical polymerizable monomer in the surface layer, thereby developing a three-dimensional network structure and obtaining a high hardness crosslinked surface layer having a very high crosslinking density. High wear resistance is achieved. On the other hand, when only monofunctional and bifunctional radically polymerizable monomers are used, the crosslink density in the cross-linked surface layer becomes dilute and a drastic 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. Furthermore, the polymer material contained therein and a radical polymerizable composition (a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure or a radical polymerizable functional group) And having a dimethylsiloxane structure as a repeating unit, it is poorly compatible with the cured product resulting from the reaction of the reaction, and local wear occurs from phase separation, resulting in surface scratches. Appears as

  In the formation of the crosslinked surface layer of the present invention, in addition to the above trifunctional or higher functional radical polymerizable monomer, the monofunctional radical polymerizable compound having a charge transporting structure and a radical polymerizable functional group, and dimethyl A reactive silicone compound characterized by having a siloxane structure as a repeating unit is contained, and these are simultaneously cured to form a high-hardness cross-linking bond, thereby achieving improved durability. Further, 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.

  Further, regarding the persistence of the low surface energy of the photosensitive layer, a reactive silicone characterized in that an additive to be contained in the photosensitive layer has a radical polymerizable functional group and has a dimethylsiloxane structure as a repeating unit. By making it a compound, it is chemically bonded or polymerized into the crosslinked structure of the photosensitive layer to increase the molecular weight and increase the crosslinking density, thereby improving the durability of the crosslinked layer and simultaneously bringing it to the surface of the additive. This suppresses the surface migration of the resin. In particular, it is possible to improve the surface migration of silicon-based compounds that have been used for the purpose of lowering the surface energy of electrophotographic photoreceptors in the past, and to increase the durability of low surface energy even during long-term use. It became possible. That is, it is possible to make use of characteristics derived from silicon compounds such as high lubricity and releasability through repeated use, and the reduction of the toner adhesion on the surface of the photoreceptor and the deterioration of the cleaning member are suppressed. That is, transferability and cleaning performance are remarkably improved through long-term use, and image defect problems such as black spots and black stripes can be suppressed over a long period of time. Accordingly, it is possible to realize an electrophotographic photosensitive member that can improve the wear resistance and maintain high image quality over a long period of time.

  In the present invention, a compound having a reactive functional group as a resin component constituting the cross-linked layer, more specifically, a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure, 1 having a charge transporting structure A functional radical polymerizable compound and a reactive silicone compound having a radical polymerizable functional group and having a dimethylsiloxane structure as a repeating unit are mixed and polymerized simultaneously to form a crosslinked surface layer. Thus, improvement in wear resistance, long-term stability of electrical characteristics, and improvement in sustainability of low surface energy can be realized.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
The trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention is a hole transport structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano. A monomer having no electron transport structure such as an electron-withdrawing aromatic ring having a group or a nitro group and having three or more radically polymerizable functional groups. 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.

（ただし、式中、Ｘ_１は、置換又は無置換のフェニレン基、ナフチレン基等のアリーレン基、置換又は無置換のアルケニレン基、−ＣＯ−基、−ＣＯＯ−基、−ＣＯＮ（Ｒ_１０）−基（Ｒ_１０は、水素、メチル基、エチル基等のアルキル基、ベンジル基、ナフチルメチル基、フェネチル基等のアラルキル基、フェニル基、ナフチル基等のアリール基を表わす。）、または−Ｓ−基を表わす。）
これらの置換基を具体的に例示すると、ビニル基、スチリル基、２−メチル−１，３−ブタジエニル基、ビニルカルボニル基、アクリロイルオキシ基、アクリロイルアミド基、ビニルチオエーテル基等が挙げられる。
（２）１，１−置換エチレン官能基としては、例えば以下の式で表わされる官能基が挙げられる。

(Wherein, X ₁ is an arylene group such as a substituted or unsubstituted phenylene group or naphthylene group, a substituted or unsubstituted alkenylene group, a —CO— group, a —COO— group, —CON (R ₁₀ ) — A group (R ₁₀ represents an alkyl group such as hydrogen, a methyl group or an ethyl group, an aralkyl group such as a benzyl group, a naphthylmethyl group or a phenethyl group, or an aryl group such as a phenyl group or a naphthyl group), or —S—. Represents a group.)
Specific examples of these substituents include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group, an acryloylamide group, and a vinyl thioether group.
(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following formulas.

（ただし、式中、Ｙは、置換又は無置換のアルキル基、置換又は無置換のアラルキル基、置換又は無置換のフェニル基、ナフチル基等のアリール基、ハロゲン原子、シアノ基、ニトロ基、メトキシ基あるいはエトキシ基等のアルコキシ基、−ＣＯＯＲ_１１基（Ｒ_１１は、水素原子、置換又は無置換のメチル基、エチル基等のアルキル基、置換又は無置換のベンジル、フェネチル基等のアラルキル基、置換又は無置換のフェニル基、ナフチル基等のアリール基、または−ＣＯＮＲ_１２Ｒ_１３（Ｒ_１２およびＲ_１３は、水素原子、置換又は無置換のメチル基、エチル基等のアルキル基、置換又は無置換のベンジル基、ナフチルメチル基、あるいはフェネチル基等のアラルキル基、または置換又は無置換のフェニル基、ナフチル基等のアリール基を表し、互いに同一または異なっていてもよい。）、また、Ｘ_２は上記式１０のＸ１と同一の置換基及び単結合、アルキレン基を表わす。ただし、Ｙ，Ｘ２の少なくとも何れか一方がオキシカルボニル基、シアノ基、アルケニレン基、及び芳香族環である。）
これらの置換基を具体的に例示すると、α−塩化アクリロイルオキシ基、メタクリロイルオキシ基、α−シアノエチレン基、α−シアノアクリロイルオキシ基、α−シアノフェニレン基、メタクリロイルアミノ基等が挙げられる。
なお、これらＸ_１、Ｘ_２、Ｙについての置換基に更に置換される置換基としては、例えばハロゲン原子、ニトロ基、シアノ基、メチル基、エチル基等のアルキル基、メトキシ基、エトキシ基等のアルコキシ基、フェノキシ基等のアリールオキシ基、フェニル基、ナフチル基等のアリール基、ベンジル基、フェネチル基等のアラルキル基等が挙げられる。
これらのラジカル重合性官能基の中では、特にアクリロイルオキシ基、メタクリロイルオキシ基が有用であり、３個以上のアクリロイルオキシ基を有する化合物は、例えば水酸基がその分子中に３個以上ある化合物とアクリル酸（塩）、アクリル酸ハライド、アクリル酸エステルを用い、エステル反応あるいはエステル交換反応させることにより得ることができる。また、３個以上のメタクリロイルオキシ基を有する化合物も同様にして得ることができる。また、ラジカル重合性官能基を３個以上有する単量体中のラジカル重合性官能基は、同一でも異なっても良い。

(In the formula, Y represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, an aryl group such as a substituted or unsubstituted phenyl group or a naphthyl group, a halogen atom, a cyano group, a nitro group, or a methoxy group. Group or an alkoxy group such as an ethoxy group, -COOR ₁₁ group (R ₁₁ is a hydrogen atom, an alkyl group such as a substituted or unsubstituted methyl group or an ethyl group, an aralkyl group such as a substituted or unsubstituted benzyl or phenethyl group, A substituted or unsubstituted phenyl group, an aryl group such as a naphthyl group, or —CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ are a hydrogen atom, a substituted or unsubstituted methyl group, an alkyl group such as an ethyl group, a substituted or unsubstituted group, Aralkyl groups such as substituted benzyl, naphthylmethyl, or phenethyl groups, or aryls such as substituted or unsubstituted phenyl and naphthyl groups It represents a group, which may be the same or different from each other.) Further, X ₂ is identical substituents and a single bond and X1 in formula 10 represents an alkylene group. However, Y, at least one of X2 is Oxycarbonyl group, cyano group, alkenylene group, and aromatic ring.)
Specific examples of these substituents 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, a halogen atom, a nitro group, a cyano group, a methyl group, an alkyl group such as an ethyl group, a methoxy group, an ethoxy group, 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.
Among these radical polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful, and a compound having three or more acryloyloxy groups is, for example, a compound having three or more hydroxyl groups in the molecule and an acrylic group. It can be obtained by using an acid (salt), an acrylic acid halide, or an acrylic ester to cause an ester reaction or a transesterification reaction. A compound having three or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

Specific examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure 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, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl Modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. These may be used alone or in combination of two or more.

  The trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention is a ratio of molecular weight to the number of functional groups in the monomer in order to form a dense crosslink in the cross-linked surface layer. (Molecular weight / functional group number) is preferably 250 or less. Further, when this ratio is larger than 250, the crosslinked surface layer is soft and wear resistance is somewhat lowered. Therefore, among the monomers exemplified above, monomers having a modifying group such as HPA, EO, and PO are extremely long. It is not preferable to use one having a modifying group alone. Moreover, the component ratio of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure used for the crosslinked surface layer is 20 to 80% by weight, preferably 30 to 70% by weight, based on the total amount of the crosslinked surface layer. When the monomer component is less than 20% 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 is 80% by weight or more, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  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. Examples of the radical polymerizable functional group include those shown in the above radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. As the charge transporting structure, a triarylamine structure is highly effective. 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.

（式中、Ｒ_１は水素原子、ハロゲン原子、置換又は無置換のアルキル基、置換又は無置換のアラルキル基、置換又は無置換のアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換又は無置換のアルキル基、置換又は無置換のアラルキル基又は置換又は無置換のアリール基）、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、置換又は無置換のアルキル基、置換又は無置換のアラルキル基又は置換又は無置換のアリール基を示し、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基、アルキレンオキシカルボニル基を表わす。ｍ、ｎは０〜３の整数を表わす。）

(In the formula, R ₁ is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a cyano group, a nitro group, an alkoxy group, —COOR ₇ ( R ₇ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group), a halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ are hydrogen atoms, A halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, which may be the same or different from each other, and Ar ₁ and Ar ₂ are Represents a substituted or unsubstituted arylene group, which may be the same or different, Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group, and X may be 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. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 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.
Substituted or unsubstituted Ar ₃ and Ar ₄ are 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 is, for example, substituted or unsubstituted as shown below.
(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.
(6)

（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。
（７）メチレンジオキシ基、又はメチレンジチオ基等のアルキレンジオキシ基又はアルキレンジチオ基等が挙げられる。
（８）置換又は無置換のスチリル基、置換又は無置換のβ−フェニルスチリル基、ジフェニルアミノフェニル基、ジトリルアミノフェニル基等。

(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 may form a ring _C 1 -C ₄ alkoxy _groups, C 1 -C a alkyl group or a halogen atom ₄ which may contain as substituents .R ₃ and _{R 4} jointly)
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.
Examples of the substituted or unsubstituted alkylene ether group include a —CH ₂ CH ₂ O— group, a CH ₂ CH ₂ CH ₂ O— group, an (OCH ₂ CH ₂ ) _h —O— group, and — (OCH ₂ CH ₂ CH ₂ ) _i- O- group, etc. are mentioned.
However, h and i in the above formula each represent an integer of 1 to 4.
The alkylene group of the alkylene ether group may have a substituent such as a hydroxyl group, a methyl group, or an ethyl group.
The vinylene group is

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基、アルキレンオキシカルボニル基を表わす。置換もしくは未置換のアルキレン基としは、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基としては、前記Ｘのアルキレンエーテル基が挙げられる。アルキレンオキシカルボニル基としては、カプロラクトン変性基が挙げられる。
また、本発明の１官能の電荷輸送構造を有するラジカル重合性化合物として更に好ましくは、下記一般式（３）の構造の化合物が挙げられる。

Represented by
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 is 1 to 2 3 is represented. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl 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 group include the alkylene ether group represented by X. Examples of the alkyleneoxycarbonyl group include a caprolactone-modified group.
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).

（式中、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、

(Wherein, 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 represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

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。
本発明により形成される架橋表面層は、クラック等の発生がなく、かつ電気特性に優れる。
すなわち、本発明で用いる上記一般式（１）及び（２）特に（３）の１官能性の電荷輸送構造を有する１官能のラジカル重合性化合物は、炭素−炭素間の二重結合が両側に開放されて重合するため、末端構造とはならず、連鎖重合体中に組み込まれ、３官能以上のラジカル重合性モノマーとの重合で架橋形成された重合体中では、高分子の主鎖中に存在し、かつ主鎖−主鎖間の架橋鎖中に存在（この架橋鎖には１つの高分子と他の高分子間の分子間架橋鎖と、１つの高分子内で折り畳まれた状態の主鎖のある部位と主鎖中でこれから離れた位置に重合したモノマー由来の他の部位とが架橋される分子内架橋鎖とがある）するが、主鎖中に存在する場合であってもまた架橋鎖中に存在する場合であっても、鎖部分から懸下するトリアリールアミン構造は、窒素原子から放射状方向に配置する少なくとも３つのアリール基を有し、バルキーであるが、鎖部分に直接結合しておらず鎖部分からカルボニル基等を介して懸下しているため立体的位置取りに融通性ある状態で固定されているので、これらトリアリールアミン構造は重合体中で相互に程よく隣接する空間配置が可能であるため、分子内の構造的歪みが少なく、また、電子写真感光体の表面層とされた場合に、電荷輸送経路の断絶を比較的免れた分子内構造を採りうるものと推測される。
本発明の電荷輸送性構造を有する１官能のラジカル重合性化合物の具体例を以下に示すが、これらの構造の化合物に限定されるものではない。

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 crosslinked surface layer formed according to the present invention is free from cracks and has excellent electrical characteristics.
That is, the monofunctional radically polymerizable compound having a monofunctional charge transport structure represented by the general formulas (1) and (2), particularly (3) used in the present invention has carbon-carbon double bonds on both sides. In the polymer that is released and polymerized, it does not become a terminal structure, but is incorporated into a chain polymer and crosslinked by polymerization with a trifunctional or higher radical polymerizable monomer. Exists in the cross-linked chain between the main chain and the main chain (in this cross-linked chain, an intermolecular cross-linked chain between one polymer and another polymer and a folded state in one polymer) There is an intramolecular cross-linked chain in which a site with a main chain and another site derived from a polymerized monomer are cross-linked at a position away from this in the main chain), but even if it exists in the main chain Even if it is present in the cross-linked chain, the triarylamine suspended from the chain part The 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 and is suspended from the chain part via a carbonyl group or the like. Since these triarylamine structures can be arranged adjacent to each other in the polymer, there is little structural distortion in the molecule. In the case of a surface layer of a photographic photoreceptor, 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 monofunctional radically polymerizable compound having a 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, when the content is 80% by weight or more, the content of a trifunctional or higher monomer having no charge transporting structure is lowered, and the crosslinking density is lowered, and high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  Next, the reactive silicone compound having a radical polymerizable functional group used in the present invention and having a dimethylsiloxane structure as a repeating unit has one or more radical polymerizable functional groups. In addition, dimethyl having a siloxane structure as a repeating unit is used. Examples of the radical polymerizable functional group include those represented by the above-described trifunctional or higher radical polymerizable monomer having no charge transport structure, and acryloyloxy group and methacryloyloxy group are particularly useful, and the curing rate and An acryloyloxy group is particularly preferable from the viewpoint of compatibility. Furthermore, as the number of acryloyloxy groups, bifunctional or higher functional groups can be used more favorably than monofunctional ones for the purpose of improving the crosslink density, and both terminal diacrylates of reactive silicone compounds exhibit good characteristics. . Further, the molecular weight of the reactive silicone compound is preferably 20000 or less, more preferably 10,000 or less. When the molecular weight exceeds 20000, the compatibility with the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure or the monofunctional radical polymerizable compound having the charge transporting structure is lowered, and the surface of the crosslinked film is smoothened. Inferior. Further, the viscosity of the reactive silicone compound at 25 ° C. is preferably 30 Pa · s or less, more preferably 20 Pa · s or less. When the viscosity exceeds 30 Pa · s, when the amount of reactive silicone added is large, the viscosity of the surface-forming coating solution becomes high, making it difficult to handle when forming the coating film. It causes a coating film defect such as a small hole or a small bubble-like blister, and the smoothness of the coating film surface is impaired. The viscosity of the present invention is measured using TV-20 (rotary viscometer manufactured by Tokimec Co., Ltd.) and a thermostatic bath under conditions of cone rotor rotation speed 1.0 rpm and 25 ° C. It may be a value measured by any device having equivalent performance. As specific examples, those having one and two radical polymerizable functional groups are shown in the general formulas (4) and (5), respectively.

（上記一般式（４）中のＲ_４１は、アクリロイルオキシ基、メタクリロイルオキシ基等、前記の電荷輸送性構造を有しない３官能以上のラジカル重合性モノマーの説明中に挙げたラジカル重合性官能基、Ｒ_４２、Ｒ_４３、Ｒ_４４、Ｒ_４５、Ｒ_４６は互いに同一又は異種の水素原子または炭素数１〜１２のアルキル基又はアリール基、Ａは炭素数２〜６のアルキレン基または単結合、ｎは２以上の整数である。）

(R ₄₁ in the above general formula (4) is the radical polymerizable functional group mentioned in the description of the radical polymerizable monomer having three or more functional groups having no charge transporting structure such as acryloyloxy group, methacryloyloxy group, etc. , R ₄₂ , R ₄₃ , R _44, R _45, R ₄₆ are the same or different hydrogen atoms or alkyl groups or aryl groups having 1 to 12 carbon atoms, A is an alkylene group or single bond having 2 to 6 carbon atoms, n is an integer of 2 or more.)

（上記一般式（５）中のＲ_４１、Ｒ_４６は、アクリロイルオキシ基、メタクリロイルオキシ基等、前記の電荷輸送性構造を有しない３官能以上のラジカル重合性モノマーの説明中に挙げたラジカル重合性官能基、Ｒ_４２、Ｒ_４３、Ｒ_４４、Ｒ_４５は互いに同一又は異種の水素原子または炭素数１〜１２のアルキル基又はアリール基、Ａは炭素数２〜６のアルキレン基または単結合、ｎは２以上の整数である。）

(R ₄₁ and R ₄₆ in the general formula (5) are radical polymerizations mentioned in the description of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure such as acryloyloxy group and methacryloyloxy group. Functional groups, R ₄₂ , R ₄₃ , R _{44 and} R ₄₅ are the same or different hydrogen atoms or alkyl groups or aryl groups having 1 to 12 carbon atoms, A is an alkylene group or single bond having 2 to 6 carbon atoms, n is an integer of 2 or more.)

  In the general formulas (4) and (5), the radical polymerizable functional group is located at the end of the polysiloxane structure, but the radical polymerizable functional group used in the present invention has a dimethylsiloxane structure. As the reactive silicone compound characterized by having as a repeating unit, the position of the radical polymerizable functional group is not limited to the end portion, and of course, it can be effectively used for those in which the side chain portion of the siloxane structure is substituted. Can do.

    The reactive silicone compound having a radically polymerizable functional group and having a dimethylsiloxane structure as a repeating unit according to the present invention provides an ester of acrylic acid (or methacrylic acid) and alkylene glycol as a known method. , A method in which a trimethylsilyl compound or a polydimethylsiloxane compound is subjected to a condensation reaction, an ester of acrylic acid (or methacrylic acid) and allyl alcohol is obtained, and a method in which a trimethylsilyl compound or a polydimethylsiloxane compound is subjected to an addition reaction However, commercially available products can also be used. Examples of commercially available products include X-22-164A (molecular weight 860, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-164B (molecular weight 1630, manufactured by Shin-Etsu Chemical Co., Ltd.), X-22-164C (molecular weight 2370, Shin-Etsu Chemical Co., Ltd.) X-22-174DX (Molecular weight 4600, Shin-Etsu Chemical Co., Ltd.), X-24-8201 (Molecular weight 2100, Shin-Etsu Chemical Co., Ltd.), X-22-2426 (Molecular weight 12000, Shin-Etsu Chemical Co., Ltd.), both end silaplane FM-7711 (molecular weight 1000, manufactured by Chisso Corporation), both end silaplane FM-7721 (molecular weight 5000, manufactured by Chisso Corporation), both end silaplane FM-7725 (manufactured by Chisso Corporation) Molecular weight 10,000, manufactured by Chisso Corporation), one-end silaplane FM-0711 (molecular weight 1000, Manufactured by Cisso Co., Ltd.), one-end silaplane FM-0721 (molecular weight 5000, manufactured by Chisso Corporation), one-end silaplane FM-0725 (molecular weight 10,000, manufactured by Chisso Corporation), one-end silaplane TM-0701 (molecular weight) 423, manufactured by Chisso Corporation), one-end silaplane TM-0701T (molecular weight 423, manufactured by Chisso Corporation), BYK-UV3500 (produced by Big Chemie Japan Corporation), BYK-UV3510 (produced by Big Chemie Japan Corporation), BYK -UV3570 (manufactured by Big Chemie Japan Co., Ltd.) TEGO Rad2100 (manufactured by Tegochemy Service), TEGO Rad2200N (manufactured by Tegochemy Service), TEGO Rad2250 (manufactured by Tegochemy Service), TEGO Rad2500 (Tegochemi) Service Co.), TEGO Rad2600 (Tego Chemie Service Co.), there may be mentioned TEGO Rad2700 (Tego Chemie Service Co., Ltd.), but is not limited thereto.

  These reactive silicone compounds may be used alone or in combination of two or more. The content of the reactive silicone compound is 0.01 to 30% by weight, preferably 0.05 to 20% by weight, based on the solid content of the coating solution forming the crosslinked surface layer. When the content of the reactive silicone compound is 0.01% by weight or less, since the proportion of the lubricant in the crosslinked surface layer is too small, sufficient low surface energy is not realized, and good cleaning properties are not exhibited. In addition, when the content of the reactive silicone compound exceeds 30% by weight, the amount of the lubricant is excessively large, and unreacted molecules that are not chemically incorporated are generated in the matrix of the surface cross-linked layer, which is an electron. This causes problems such as fluctuations in electrical characteristics when the photographic process is repeated, leading to phenomena such as a decrease in image density and thinning of characters. The required electrical characteristics and abrasion 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 0.05 to 20% by weight is most preferable.

  The surface layer of the present invention comprises at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure, and a reactive silicone compound having a radical polymerizable functional group. Although it is a crosslinked surface layer cured at the same time, filler fine particles can be contained for the purpose of improving wear resistance.

  The following can be used as the filler fine particles. Examples of organic filler materials include fluororesin powders such as polytetrafluoroethylene, silicone resin powders, A-carbon powders, etc., and inorganic filler materials include copper, tin, aluminum, Examples thereof include metal powders such as indium, metal oxides such as silicon oxide, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, and bismuth oxide, and inorganic materials such as potassium titanate. In particular, it is advantageous to use an inorganic material among them from the viewpoint of the hardness of the filler. In particular, metal oxides are good, and silicon oxide, aluminum oxide, and titanium oxide can be used effectively. Also, fine particles such as colloidal silica and colloidal alumina can be used effectively.

  The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the 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 wear 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 filler dispersibility. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating film, causes defects in the coating film, 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. For example, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, higher fatty acids, etc., or mixed treatments of these with silane coupling agents, Al ₂ O ₃ , TiO ₂ , ZRO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image blur. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. 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.

  The surface layer of the present invention comprises at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure, and a reactive silicone compound having a radical polymerizable functional group. Although it is a crosslinked surface layer that has been cured at the same time, it is monofunctional and bifunctional for the purpose of imparting functions such as viscosity adjustment during coating of the surface layer, stress relaxation of the crosslinked surface layer, low surface free energy and reduced friction coefficient. A radical polymerizable monomer and a radical polymerizable oligomer can be used in combination. Known radical polymerizable monomers and oligomers can be used.

  Examples of the monofunctional radical monomer include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, and cyclohexyl acrylate. , Isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, and the like.

  Examples of the bifunctional radical polymerizable monomer include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1, Examples include 6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, and neopentyl glycol diacrylate.

  Examples of the functional monomer include those substituted with fluorine atoms such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, and 2-perfluoroisononylethyl acrylate.

  Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers. However, when a large amount of monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, 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 50 parts by weight or less, preferably 30 parts by weight or less, with respect to 100 parts by weight of the tri- or higher functional radical polymerizable monomer.

  The surface layer of the present invention comprises at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure, and a reactive silicone having a radical polymerizable functional group. Although it is a crosslinked surface layer obtained by simultaneously curing the compound, 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 promotion effect can also be used individually or in combination with the said photoinitiator. Examples 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.

  Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. 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 comprises at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure, and a reactive silicone compound having a radical polymerizable functional group. It is formed by applying and hardening a coating solution containing 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 higher and 170 ° C. or lower. If the heating temperature is lower 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 advance 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 the ease of reaction rate control and the simplicity of the 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. 1A shows a case where a crosslinked surface layer is formed by crosslinking and curing the entire photosensitive layer, and FIG. 1B shows a case where the crosslinked surface layer is provided on the surface portion of the photosensitive layer.
FIG. 2 is a view showing 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. 2A shows a case where the entire charge transport layer is crosslinked and cured to form a crosslinked surface layer, and FIG. 2B shows a case where a crosslinked surface layer is provided on 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>
(About the charge generation layer)
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.
Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having 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, etc. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.

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.

(About 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 (trifunctional or higher functional group having no charge transport structure) is formed on the charge generation layer as described in the above cross-linked surface layer preparation method. A coating solution containing a radically polymerizable monomer, a monofunctional radically polymerizable compound having a charge transporting structure and a reactive silicone compound having a radically polymerizable functional group; the same applies hereinafter) is applied, and if necessary, dried. The curing reaction is initiated by external energy, and 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 polymer charge transport materials listed above can also be used, which is useful in that contamination of the lower layer 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 becomes the surface portion of the photosensitive layer, an intermediate layer can be provided between the crosslinked surface 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. The thickness of the intermediate layer is suitably about 0.05 to 2 μm.

<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 anodic oxidation, organic matter 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.
(Phenolic 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-tert-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-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-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid ] Cryol ester, tocopherols and the like.

(Paraphenylenediamines)
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.

(Hydroquinones)
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.

(Organic sulfur compounds)
Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.

(Organic phosphorus compounds)
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
These compounds are known as antioxidants 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 a photoconductor having a charge transporting cross-linked surface layer having a smooth and low surface energy. For example, at least the photoconductor is charged, image exposed, and developed. After that, an image forming method and an image forming apparatus including a process of transferring a toner image onto an image holding member (transfer paper), fixing, and cleaning the surface of the photosensitive member.
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 photoconductor 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 photoconductor onto the transfer body (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 photoreceptor after transfer. Further, a pre-cleaning charger (13) may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a 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 the image forming apparatus includes a photoreceptor (101), and in addition, a charging unit (102), a developing unit (104), a transfer unit (106), a cleaning unit (107), and a discharging unit (not shown). ), And an apparatus (part) that can be attached to and detached from the image forming apparatus main body.

Referring to the image forming process by the apparatus illustrated in FIG. 4, the surface of the photoreceptor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. Out. Next, the surface of the photoconductor after the image transfer is cleaned by a cleaning unit (107), and is 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 photosensitive member having a polymer charge transport layer and a crosslinked surface layer is integrated with at least one of charging, developing, transferring, cleaning, and neutralizing 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 Compound having Charge Transporting Structure>
The compound having a charge transporting 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）トリアリールアミノ基置換アクリレート化合物（表１中の例示化合物Ｎｏ．５４）
上記（１）で得られたヒドロキシ基置換トリアリールアミン化合物（構造式Ｂ）８２．９ｇ（０．２２７ｍｏｌ）をテトラヒドロフラン４００ｍｌに溶解し、窒素気流中で水酸化ナトリウム水溶液（ＮａＯＨ：１２．４ｇ，水：１００ｍｌ）を滴下した。この溶液を５℃に冷却し、アクリル酸クロライド２５．２ｇ（０．２７２ｍｏｌ）を４０分かけて滴下した。その後、５℃で３時間撹拌し反応を終了させた。この反応液を水に注ぎ、トルエンにて抽出した。この抽出液を炭酸水素ナトリウム水溶液と水で繰り返し洗浄した。その後、このトルエン溶液から溶媒を除去し、カラムクロマト処理（吸着媒体：シリカゲル、展開溶媒：トルエン）にて精製した。得られた無色のオイルにｎ−ヘキサンを加え、結晶を析出させた。この様にして例示化合物Ｎｏ．５４の白色結晶８０．７３ｇ（収率＝８４．８％）を得た。
融点：１１７．５〜１１９．０℃

(2) Triarylamino group-substituted acrylate compound (Exemplary Compound No. 54 in Table 1)
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 solution Alkyd resin: 6 parts (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin: 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide: 40 parts Methyl ethyl ketone: 50 parts Charge generation layer coating solution Bisazo pigment having the following structure: 2.5 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
・電荷輸送層塗工液
ビスフェノールＺ型ポリカーボネート：１０部
（パンライトＴＳ−２０５０、帝人化成製）
下記構造式の電荷輸送物質：７部

Polyvinyl butyral (XYHL, manufactured by UCC): 0.5 part Cyclohexanone: 200 parts Methyl ethyl ketone: 80 parts Charge transport layer coating solution Bisphenol Z-type polycarbonate: 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals)
Charge transport material of the following structural formula: 7 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）
電荷輸送層上に更に、下記構成の架橋表面層塗工液を用いて、スプレー塗工し、メタルハライドランプ、照射強度：７００ｍＷ／ｃｍ２、照射時間：２０秒の条件で光照射を行ない、更に１３０℃で３０分乾燥を加え４．０μｍの架橋表面層を設け、電子写真感光体を作成した。
・架橋表面層塗工液
電荷輸送性構造を有さない３官能以上のラジカル重合性モノマー：９５部
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
分子量：２９６．３２
官能基数：３
分子量／官能基数＝９９
電荷輸送性構造を有する１官能の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
ラジカル重合性官能基を有する反応性シリコーン化合物：１０部
両末端メタクリル変性ポリシロキサン：Ｘ−２２−１６４Ａ、信越シリコーン製

Tetrahydrofuran: 100 parts 1% silicone oil in tetrahydrofuran solution: 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
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: 700 mW / cm 2, irradiation time: 20 seconds, and further 130 Drying was carried out at 30 ° C. for 30 minutes to provide a 4.0 μm crosslinked surface layer to prepare an electrophotographic photosensitive member.
-Crosslinked surface layer coating solution Trifunctional or higher functional radical polymerizable monomer having no charge transport structure: 95 parts Trimethylolpropane triacrylate: TMPTA, manufactured by Tokyo Chemical Industry Molecular weight: 296.32
Functional group number: 3
Molecular weight / number of functional groups = 99
Monofunctional radically polymerizable compound having a charge transporting structure: 95 parts 54
Photoinitiator: 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone:
Irgacure 184, manufactured by Ciba Specialty Chemicals Tetrahydrofuran: 1200 parts Reactive silicone compound having a radical polymerizable functional group: 10 parts Both-end methacryl-modified polysiloxane: X-22-164A, manufactured by Shin-Etsu Silicone

Example 2
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the reactive silicone compound having a radical polymerizable functional group contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
One-end methacryl-modified polysiloxane: X-22-174DX, manufactured by Shin-Etsu Silicone

Example 3
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the reactive silicone compound having a radical polymerizable functional group contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
Polydimethylsiloxane having a polyether-modified acrylic group: BYK-UV3500, manufactured by Big Chemie

Example 4
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the reactive silicone compound having a radical polymerizable functional group contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
70% solution of polydimethylsiloxane having polyester-modified acrylic group (PO-modified-2-neopentylglycol diacrylate): BYK-UV3570, manufactured by BYK Chemie

Example 5
The same procedure as in Example 1 was conducted except that the reactive silicone compound having a radical polymerizable functional group contained in the crosslinked surface layer coating solution in Example 1 was changed to the following and the content was changed to 0.11 part. An electrophotographic photosensitive member was prepared.
Cross-linking reactive silicone compound polyether acrylate: TEGO Rad2200N, manufactured by German Chemie Service

Example 6
The same procedure as in Example 1 was conducted except that the reactive silicone compound having a radical polymerizable functional group contained in the crosslinked surface layer coating solution in Example 1 was changed to the following and the content was 50 parts. A photoconductor was prepared.
Both end silaplane: FM-7721, manufactured by Chisso Corporation

Example 7
In all the same manner as in Example 1 except that the trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials. Created the body.
Pentaerythritol tetraacrylate: SR-295, manufactured by Kayaku Sartomer, molecular weight: 352.34
Number of functional groups: 4
Molecular weight / number of functional groups: 88

Example 8
An electrophotographic photoreceptor in the same manner as in Example 1 except that the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials. It was created.
Dipentaerythritol hexaacrylate: KAYARAD DPHA, manufactured by Nippon Kayaku Molecular weight: 551.55
Functional group number: 5.5
Molecular weight / number of functional groups = 100

Example 9
Except for changing the trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 to a mixture of the following materials, the same procedure as in Example 1 was performed. An electrophotographic photoreceptor was prepared.
Trimethylolpropane triacrylate: TMPTA, manufactured by Tokyo Chemical Industry, 47 parts Molecular weight: 296.32
Functional group number: 3
Molecular weight / number of functional groups = 99
Caprolactone-modified dipentaerythritol hexaacrylate: KAYARAD DPCA-120, manufactured by Nippon Kayaku, 47 parts Molecular weight: 1948.3
Number of functional groups: 6
Molecular weight / number of functional groups = 325

Example 10
In Example 1, the radical polymerizable compound having a charge transporting structure contained in the crosslinked surface layer coating solution is exemplified as No. 1. An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the number was changed to 16.

Example 11
In Example 1, the radical polymerizable compound having a charge transporting structure contained in the crosslinked surface layer coating solution is exemplified as No. 1. An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the number was changed to 24.

Example 12
An electrophotographic photoreceptor was prepared 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 Trifunctional or higher functional radical polymerizable monomer having no charge transporting structure: 90 parts Caprolactone-modified dipentaerythritol hexaacrylate: KAYARAD DPCA-120, Nippon Kayaku Co., Ltd. Molecular weight: 1948.3
Number of functional groups: 6 functions Molecular weight / number of functional groups = 325
Monofunctional radically polymerizable compound having a charge transporting structure: 90 parts 54
Photopolymerization initiator: 20 parts 1-hydroxy-cyclohexyl-phenyl-ketone: Irgacure 184, manufactured by Ciba Specialty Chemicals Tetrahydrofuran: 90 parts Reactive silicone compound having a radical polymerizable functional group: 10 parts Both-end methacryl-modified polysiloxane : X-22-164A, manufactured by Shin-Etsu Silicone Molecular weight: 860
Viscosity 25 ° C .: 25 mm ² / s
Refractive index 25 ° C .: 1.415
Specific gravity 25 ° C: 0.98
Fine filler 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 reactive silicone compound contained in the crosslinked surface layer coating solution in Example 1 was not added.

Comparative Example 2
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was not added. did.

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

Comparative Example 4
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 in Example 1 was changed to the following material.
90 parts of radically polymerizable monomer having no charge transport structure of the following structural formula

２官能アクリレート：ＫＡＹＡＲＡＤ ＮＰＧＤＡ、日本化薬製
分子量：２１２
官能基数：２官能
分子量／官能基数＝１０６

Bifunctional acrylate: KAYARAD NPGDA, manufactured by Nippon Kayaku Molecular weight: 212
Functional group number: bifunctional Molecular weight / functional group number = 106

Comparative Example 5
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable compound having a charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials.
90 parts of a radically polymerizable compound having a charge transporting structure of the following structural formula

Comparative Example 6
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the reactive silicone compound contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials.
Methylphenyl silicone oil without radical polymerizable functional group: KF50-100CS, manufactured by Shin-Etsu Silicone

Comparative Example 7
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the crosslinked layer was not provided in Example 1 and the thickness of the charge transport layer was changed to 27 μm.

  The electrophotographic photosensitive member produced as described above is mounted on an electrophotographic process cartridge, and the dark portion potential is changed by a Ricoh imagio MF2200 remodeling machine using a DC contact roller type charging method and a 655 nm semiconductor laser as an image exposure light source. After setting to 700 (-V), a total of 50,000 sheets were continuously passed through the actual machine, and wear characteristics, in-machine potential, and image evaluation were performed. Table 4 shows the wear characteristics, Table 5 shows the in-machine potential, and Table 6 shows the image evaluation. Moreover, about Examples 1, 2, 3, 4, and 6, ten-point average roughness (Rz) was measured using the surface roughness shape measuring machine Surfcom 1400D by Tokyo Seimitsu. The results are shown in Table 7. Further, for Examples 1, 3, 8, and 10 and Comparative Examples 1 and 6, the contact angle measurement with respect to pure water was performed using the CA-W type automatic contact angle meter manufactured by Kyowa Interface Science Co., Ltd. after the initial and 10,000 sheet passing tests. Table 8 shows the results.

画像濃度：○→良好、△→わずかに画像濃度低下、×→画像濃度低下
画像欠陥：○→良好、△→局部的に発生、×→画像全面に発生

Image density: ○ → Good, Δ → Slight image density reduction, × → Image density reduction

In each of Comparative Examples 1, 4, 6, and 7, it was impossible to achieve both improvement in wear resistance over a long period of time and maintenance of high-quality images. In Comparative Example 2, a surface cross-linked layer could not be formed. In Comparative Example 3, the bright portion potential was high from the beginning, and the image density was significantly reduced.
Also, from Table 7, in the photoreceptors of the examples, those containing reactive silicone having an acryloyloxy group show a small Rz value and realize good surface smoothness. It can also be seen that a small Rz value is obtained even for a reactive silicone having a low molecular weight and a low viscosity.
In addition, it can be seen from Table 8 that the improvement in the sustainability of the low surface energy was realized by including the reactive silicone compound.

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 Photosensitive drum 102 Charging device 103 Exposure 104 Developing device 105 Transfer body 106 Transfer device 107 Cleaning blade

Claims (18)

In an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer has at least a trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure and a monofunctional having a charge transporting structure. An electrophotographic photosensitive member characterized by being a crosslinked layer obtained by curing a reactive silicone compound having a radical polymerizable compound and a radical polymerizable functional group, and having a dimethylsiloxane structure as a repeating unit. 2. The electrophotographic photoreceptor according to claim 1, wherein the functional group of the reactive silicone compound is an acryloyloxy group or a methacryloyloxy group. The electrophotographic photosensitive member according to claim 1, wherein the functional group of the reactive silicone compound is an acryloyloxy group. 4. The electrophotographic photosensitive member according to claim 1, wherein the number of acryloyloxy groups of the reactive silicone compound is 2 or more. 5. The electrophotographic photosensitive member according to claim 1, wherein the molecular weight of the reactive silicone compound is 10,000 or less. The electrophotographic photosensitive member according to claim 1, wherein the reactive silicone compound has a viscosity at 25 ° C. of 20 Pa · s or less. 7. The electron according to claim 1, wherein the content of the reactive silicone compound is 0.05 to 20% by weight or less based on the solid content of the coating liquid forming the crosslinked layer. Photoconductor. 8. The functional group of a tri- or higher functional radical polymerizable monomer having no charge transport structure used for the surface layer is an acryloyloxy group or a methacryloyloxy group. Electrophotographic photoreceptor. The ratio of the molecular weight to the number of functional groups (molecular weight / number of functional groups) in a tri- or higher functional radical polymerizable monomer having no charge transport structure used for the surface layer is 250 or less. The electrophotographic photosensitive member according to any one of the above. 10. The electron 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. Photoconductor. The electrophotographic apparatus according to any one of claims 1 to 10, wherein the charge transporting structure of the monofunctional radically polymerizable compound having a charge transporting structure used for the surface layer is a triarylamine structure. Photoconductor. 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 described.

(In the formula, R ₁ is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a cyano group, a nitro group, an alkoxy group, —COOR ₇ ( R ₇ is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group), a halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ are hydrogen atoms, A halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, which may be the same or different from each other, and Ar ₁ and Ar ₂ are Represents a substituted or unsubstituted arylene group, which may be the same or different, Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group, and X may be 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. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group or an alkyleneoxycarbonyl group, and m and n represent an integer of 0 to 3.) The electrophotography according to any one of claims 1 to 12, 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). Photoconductor.

(Wherein, 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 represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,

Represents. ) The electrophotographic photosensitive member according to claim 1, wherein filler fine particles are dispersed in the surface layer. 16. The electrophotographic photosensitive member according to claim 1, wherein the surface layer curing means is heating or light energy irradiation means. 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. An electrophotographic photosensitive member according to any one of claims 1 to 15, and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, a cleaning means and a charge eliminating means, A process cartridge for an image forming apparatus, wherein the process cartridge is removable from a main body of the forming apparatus.

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