JP4512495B2 - Electrophotographic photosensitive member, image forming method using the same, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Description

  The present invention uses a photosensitive layer having high abrasion resistance, good film surface properties, and good electrical characteristics, thereby providing stable electrical characteristics and high-quality image formation for a long time as well as excellent durability. 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 cleaning properties as the particle size of toner particles is reduced. This also promotes the wear of the photoconductor. Is a factor. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.

Therefore, it is indispensable to reduce the amount of wear as described above in order to increase the durability of the organic photoreceptor, and an organic photoreceptor having a good surface property is required in order to impart excellent cleaning properties and transferability. These are the most pressing issues in the field.
Techniques for improving the abrasion resistance of the photosensitive layer include (1) using a curable binder for the surface layer (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. In the techniques (1) to (3), the overall durability including the electrical durability and mechanical durability required for the organic photoreceptor has not been sufficiently satisfied.

On the other hand, 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 cracks are generated, and the mechanical strength is also lowered.
Moreover, although there is also a description that a polycarbonate resin is contained for improving compatibility, the content of the curable acrylic monomer is reduced, and as a result, sufficient wear resistance cannot be achieved. In addition, for photoreceptors that do not contain a charge transport material in the surface layer, there is a description that the surface layer is a thin film in order to lower the exposed area potential, but because the film thickness is thin, the life of the photoreceptor is short, and the exposed area potential is also reduced. However, the current situation is that sufficient values have not been maintained.

  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. It may be easy to do and does not have sufficient durability.
From the above, it can not be said that the conventional photoreceptors having a crosslinked photosensitive layer in which the charge transporting structure is chemically bonded have sufficient overall 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

  An object of the present invention is to provide an electrophotographic film that achieves excellent durability and stable electric characteristics over a long period of time by using a photosensitive layer having high wear resistance, good surface properties, and good electric characteristics. It is to provide a photoreceptor, 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 photoreceptor.

  In the electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer has at least a radical polymerizable monomer having no charge transporting structure represented by the general formula (A); It discovered that the said subject could be achieved by forming by hardening | curing the radically polymerizable compound which has a monofunctional charge transport structure, and came to make this invention.

  That is, the above-mentioned problem is (1) “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 charge transport represented by the following general formula (A)”. An electrophotographic photoreceptor formed by curing a radically polymerizable monomer having no functional structure and a radically polymerizable compound having a monofunctional charge transporting structure;

（式中、Ｒ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６は水素又は

(Wherein R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ are hydrogen or

を示し、Ｒ_７７は単結合、アルキレン基、アルキレンエーテル基、又はアルキレンオキシカルボニル基を示し、Ｒ_７８は水素又はメチル基を示す。但し、Ｒ_７１乃至Ｒ_７６が同時に二つ以上が水素であることはない。）」、（２）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物の官能基が、アクリロイルオキシ基及び／又はメタクリロイルオキシ基であることを特徴とする前記第（１）項に記載の電子写真感光体」、（３）「前記最表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物の電荷輸送構造が、トリアリールアミン構造であることを特徴とする前記第（１）項又は第（２）項に記載の電子写真感光体」、（４）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物が、下記一般式（１）又は（２）の一種以上であることを特徴とする前記第（１）項乃至第（３）項のいずれかに記載の電子写真感光体；

R ₇₇ represents a single bond, an alkylene group, an alkylene ether group, or an alkyleneoxycarbonyl group, and R ₇₈ represents hydrogen or a methyl group. However, two or more of R _{71 to} R ₇₆ are not hydrogen at the same time. ) ”, (2)“ The functional group of the radically polymerizable compound having a monofunctional charge transporting structure used for the surface layer is an acryloyloxy group and / or a methacryloyloxy group ” The electrophotographic photosensitive member according to 1), (3) “The charge transport structure of the radical polymerizable compound having a monofunctional charge transport structure used for the outermost surface layer is a triarylamine structure. The electrophotographic photosensitive member according to the item (1) or (2), characterized in that the radical polymerizable compound having a monofunctional charge transport structure used for the surface layer is: The electrophotographic photosensitive member according to any one of (1) to (3), wherein the electrophotographic photosensitive member is one or more of general formula (1) or (2);

〔式中、Ｒ_１は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を表す。）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい。）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、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。〕」、（５）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物が、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（４）項のいずれかに記載の電子写真感光体；

[Wherein, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, A group, an alkoxy group, —COOR ₇ (R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. ), A halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group which may be the same or different, and Ar ₁ and Ar ₂ represent 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 may be the same or different. 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. 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. ], (5) The above item (1), wherein the radical polymerizable compound having a monofunctional charge transport structure used in the surface layer is one or more of the following general formula (3): Thru | or electrophotographic photoreceptor in any one of (4) term;

（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。）」、（６）「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（５）項のいずれかに記載の電子写真感光体」、（７）「前記感光層が支持体側から電荷発生層、電荷輸送層、架橋表面層の積層構成であることを特徴とする前記第（１）項乃至第（６）項のいずれかに記載の電子写真感光体」によって解決される。
また、上記課題は、本発明の（８）「前記第（１）項乃至第（７）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」によって解決される。
また、上記課題は、本発明の（９）「前記第（１）項乃至第（７）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」によって解決される。
また、上記課題は、本発明の（１０）「前記第（１）項乃至第（７）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、クリーニング手段および除電手段よりなる群から選ばれた少なくとも一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ」によって解決される。

Represents. ) ", (6)" Electrophotographic photosensitive member according to any one of items (1) to (5), wherein the surface layer curing means is heating or light energy irradiation means " (7) The item (1) to (6), wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a cross-linked surface layer from the support side. This is solved by the “electrophotographic photoreceptor”.
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 (8) and “(1) to (7)” of the present invention. The image forming method is characterized in that it is solved.
In addition, the above-described problem is solved by (9) “an image forming apparatus having the electrophotographic photosensitive member according to any one of (1) to (7)” of the present invention. .
Further, the above-mentioned problems are solved by (10) “the electrophotographic photosensitive member according to any one of the above items (1) to (7)”, a charging unit, a developing unit, a transferring unit, a cleaning unit, and a static eliminating 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.

  According to the present invention, a compound having a reactive functional group as a resin component for forming a crosslinked layer on the surface layer of the photosensitive layer, more specifically, a radical having no charge transporting structure represented by the general formula (A) By mixing a polymerizable monomer and a monofunctional radically polymerizable monomer having a charge transporting structure, and simultaneously carrying out a polymerization reaction to obtain a cured crosslinked resin layer, it has high wear resistance and good electrical properties, Further, it is possible to obtain a photoreceptor capable of forming a good image over a long period. 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.

Hereinafter, the present invention will be described in detail.
In the formation of the surface layer, the photoreceptor of the present invention is

（式中、Ｒ_７１、Ｒ_７２、Ｒ_７３、Ｒ_７４、Ｒ_７５、Ｒ_７６は水素又は

(Wherein R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ are hydrogen or

を示し、Ｒ_７７は単結合、アルキレン基、アルキレンエーテル基、アルキレンオキシカルボニル基を示し、Ｒ_７８は水素およびメチル基を示す。但し、Ｒ_７１乃至Ｒ_７６が同時に二つ以上が水素であることはない。）
で表わされる電荷輸送性構造を有しないラジカル重合性モノマーを用いており、これにより３次元の網目構造が発達し、架橋度が非常に高い高硬度架橋表面層が得られ、高い耐摩耗性が達成される。これに対し、ラジカル重合性官能基の少ないモノマーのみを用いた場合は、架橋表面層中の架橋結合が希薄となり飛躍的な耐摩耗性向上が達成されない。また、架橋表面層に高分子材料が含有されている場合、３次元網目構造の発達が阻害され架橋度の低下が起こり、本発明に比べ充分な耐摩耗性が得られない。更に、含有される高分子材料とラジカル重合性組成物（ラジカル重合性モノマーや電荷輸送性構造を有するラジカル重合性化合物）の反応より生じた硬化物との相溶性が悪く、相分離から局部的な摩耗が生じ、表面の傷となって現れる。

R ₇₇ represents a single bond, an alkylene group, an alkylene ether group or an alkyleneoxycarbonyl group, and R ₇₈ represents hydrogen and a methyl group. However, two or more of R _{71 to} R ₇₆ are not hydrogen at the same time. )
A radically polymerizable monomer having no charge transporting structure represented by the following formula is used, whereby a three-dimensional network structure is developed, a highly hard crosslinked surface layer having a very high degree of crosslinking is obtained, and high wear resistance is obtained. Achieved. On the other hand, when only a monomer having few radical polymerizable functional groups is used, the cross-linking bond in the cross-linked surface layer becomes dilute, and a drastic improvement in wear resistance cannot be achieved. Further, when a polymer material is contained in the crosslinked surface layer, the development of the three-dimensional network structure is hindered and the degree of crosslinking is lowered, so that sufficient wear resistance cannot be obtained as compared with the present invention. Furthermore, the compatibility between the polymer material and the cured product resulting from the reaction of the radical polymerizable composition (radical polymerizable monomer or radical polymerizable compound having a charge transporting structure) is poor, resulting in localized from phase separation. Wears and appears as a scratch on the surface.

  In addition, in the formation of the crosslinked surface layer of the present invention, a monofunctional radically polymerizable compound having a charge transporting structure is used in addition to the radically polymerizable monomer having no charge transporting structure represented by the general formula (A). To do. As a result, these are simultaneously cured in a short time, and a high hardness cross-linked surface layer is formed, whereby a photoconductor having high durability can be obtained. In addition, the compatibility problem caused when the charge transport material is contained in the cross-linked surface layer is also solved. Furthermore, it becomes possible to realize the formation of a smooth surface layer by improving the curing rate, and it is possible to maintain good cleaning properties over a long period of time.

  Furthermore, a radically polymerizable monomer having a large number of reactive functional groups and a high curing rate and not having a charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure are cured. This makes it possible to form a uniform crosslinked film with less distortion in the crosslinked layer. As a result, the unreacted portion of the charge transport material is reduced in the crosslinked surface layer, and the homogeneity inside the crosslinked film is greatly improved. The As a result, the wear resistance is improved and at the same time, both stable electrostatic characteristics are realized.

In other words, according to the present invention, various performances such as wear resistance, cleaning properties, and electrical characteristics are not deteriorated by the surrounding environment such as temperature and humidity based on storage or installation location of the photoconductor, and paper can be passed for a long time. On the other hand, it is possible to achieve both stable wear resistance and high image quality. In addition, since a monofunctional radically polymerizable compound having a charge transporting structure is incorporated in the cross-linked layer, stable electric characteristics are exhibited over a long period of time.
On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, as described above, precipitation of the low molecular charge transport material or white turbidity occurs due to its low compatibility, The mechanical strength of the crosslinked surface layer is also reduced. 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 crosslinked surface layer Internal stress increases, and cracks and scratches occur frequently due to carrier adhesion. In addition, since a plurality of bonds are fixed in the crosslinked structure, the intermediate structure (cation radical) at the time of charge transport cannot be stably maintained, and 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.
Therefore, according to the present invention, it is possible to solve such problems of the prior art and realize an electrophotographic photosensitive member capable of maintaining high image quality over a long period of time while improving wear resistance. .

  That is, the present invention provides a compound having a reactive functional group as a resin component constituting the crosslinked layer, more specifically, a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a charge. A monofunctional radically polymerizable compound having a transporting structure is simultaneously polymerized to form a crosslinked surface layer. As a result, it is possible to improve the wear resistance, improve the long-term stability of electrical characteristics, and improve the sustainability of high-quality image formation.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
The radically polymerizable monomer having no charge transporting structure used in the present invention has the general formula (A)
In order to achieve the object of the present invention, a monomer represented by the formula (1) and having 5 or more radical polymerizable functional groups of acryloyloxy group or methacryloyloxy group is preferable.

  A compound having 5 or more acryloyloxy groups can be prepared by, for example, using a compound having 5 or more hydroxyl groups in the molecule and acrylic acid (salt), acrylate halide, or acrylate ester, and performing ester reaction or transesterification reaction. Obtainable. A compound having 5 or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having 5 or more radical polymerizable functional groups may be the same or different.

  The radical polymerizable monomer having no charge transport structure represented by the general formula (A) includes a compound having 3 acryloyloxy groups and 3 hydrogen groups, 4 acryloyloxy groups and 2 hydrogen groups. A compound having 5 acryloyloxy groups and 1 hydrogen group, a compound having 6 acryloyloxy groups, a compound having 3 methacryloyloxy groups and 3 hydrogen groups, 4 methacryloyloxy Examples thereof include compounds having a group and two hydrogen groups, compounds having five methacryloyloxy groups and one hydrogen group, compounds having six methacryloyloxy groups, and the like. However, it is not limited to these compounds.

これらは、単独又は２種類以上を併用しても差し支えない。

These may be used alone or in combination of two or more.

These monomers can be exemplified by being produced by esterification of polyhydric alcohols for reasons such as excellent yields, low production costs and high productivity, and more than two types of these monomers. When two, three or four types are used in combination and a monomer having six radical polymerizable functional groups is used, six radical polymerizable functional groups are obtained by esterification in that the yield is excellent. It is preferable to use a mixture of a monomer having a hydrogen atom and a monomer having 5 or less radical polymerizable functional groups in which hydrogen groups remain without being esterified. Furthermore, the blending ratio is preferably 20 to 99% by weight, more preferably 30 to 97% by weight, and still more preferably 40 to 95% by weight, in that the yield is also excellent. For the same reason, when a monomer having five radical polymerizable functional groups is used, it is preferable to contain 20 to 99% by weight of this monomer, more preferably 30 to 97% by weight, still more preferably 40 to 95% by weight. When a monomer having four radical polymerizable functional groups is used for the same reason, it is preferable to contain 0.01 to 30% by weight of this monomer, more preferably 0.1 to 20% by weight, More preferably, it is 3 to 5% by weight. When a monomer having three radical polymerizable functional groups is used for the same reason, it is preferable to contain this monomer in an amount of 0.01 to 30% by weight, more preferably 0 to 0%. 0.1 to 20% by weight, more preferably 3 to 5% by weight.
More specifically, for the same reason, 30 to 70% by weight, preferably 40 to 60% by weight of a compound having 5 acryloyloxy groups and 1 hydrogen group, and 70 to 30% by weight of a compound having 6 acryloyloxy groups. %, Preferably a mixture containing 60 to 40% by weight, a compound having 5 acryloyloxy groups and one hydrogen group 30 to 65% by weight, preferably 40 to 55% by weight, 6 acryloyloxy groups The compound having 65 to 30% by weight, preferably 55 to 40% by weight, and one, two, three or four selected from the compounds listed below are 0.01 to 5% by weight, preferably Is a mixture containing 1-3% by weight,
-Compound having 1 acryloyloxy group and 5 hydrogen groups-Compound having 2 acryloyloxy groups and 4 hydrogen groups-Compound having 3 acryloyloxy groups and 3 hydrogen groups-4 Compounds having 1 acryloyloxy group and 2 hydrogen groups 5 methacryloyloxy groups and 1 hydrogen group 30-70 wt%, preferably 40-60 wt% and 6 methacryloyloxy groups A mixture containing 70 to 30% by weight, preferably 60 to 40% by weight of a compound having 30 to 65% by weight, preferably 40 to 55% by weight, a compound having 5 methacryloyloxy groups and one hydrogen group, 6 65 to 30% by weight, preferably 55 to 40% by weight of a compound having one methacryloyloxy group, and the compounds listed below One selected from among, two, three or four 0.01 to 5 wt%, preferably a mixture containing 1-3 wt% can be exemplified.
-Compound having 1 methacryloyloxy group and 5 hydrogen groups-Compound having 2 methacryloyloxy groups and 4 hydrogen groups-Compound having 3 methacryloyloxy groups and 3 hydrogen groups-4 Compound having 1 methacryloyloxy group and 2 hydrogen groups In addition, the proportion of the radical polymerizable monomer having no charge transporting structure represented by the general formula (A) used in the crosslinked surface layer is the total amount of the crosslinked surface layer. The content is preferably 3 to 95%, more preferably 5 to 80% by weight, and still more preferably 10 to 70% by weight. When the monomer component is 3% by weight or more, the three-dimensional cross-linking density of the cross-linked surface layer is high, and a dramatic improvement in wear resistance is achieved as compared with the case where a conventional thermoplastic binder resin is used. On the other hand, when the content is 95% by weight or less, the content of the charge transporting compound is high and the electrical characteristics are hardly deteriorated.

Examples of the monofunctional radically polymerizable compound having a charge transport structure used in the present invention include hole transport structures such as triarylamine, hydrazone, pyrazoline and carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, A compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having a radical polymerizable functional group. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and can be radically polymerized.
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、置換基を有していてもよいフェニレン基、ナフチレン基等のアリーレン基、置換基を有していてもよいアルケニレン基、−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 phenylene group or a naphthylene group optionally having a substituent, an alkenylene group optionally having a substituent, a —CO— group, a —COO— group. , —CON (R ₁₀ ) — group (R ₁₀ represents an alkyl group such as hydrogen, methyl group or ethyl group, an aralkyl group such as benzyl group, naphthylmethyl group or phenethyl group, or an aryl group such as phenyl group or naphthyl group. Or -S- 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、置換基を有していてもよいアルキル基、置換基を有していてもよいアラルキル基、置換基を有していてもよいフェニル基、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、置換基を有していてもよいメチル基、エチル基等のアルキル基、置換基を有していてもよいベンジル、フェネチル基等のアラルキル基、置換基を有していてもよいフェニル基、ナフチル基等のアリール基を表す。）または−ＣＯＮＲ_１２Ｒ_１３（Ｒ_１２およびＲ_１３は、水素原子、置換基を有していてもよいメチル基、エチル基等のアルキル基、置換基を有していてもよいベンジル基、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、または置換基を有していてもよいフェニル基、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Ｘ_１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，Ｘ_２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さら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る。
また、電荷輸送性構造としてはトリアリールアミン構造が効果が高い。さらに、下記一般式（１）又は（２）の構造で示される化合物を用いた場合、感度、残留電位等の電気的特性が良好に持続される。

[Wherein Y represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, an aryl such as a naphthyl group, etc. Group, halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ₁₁ group (R ₁₁ is a hydrogen atom, an alkyl such as an optionally substituted methyl group or ethyl group) An aralkyl group such as a benzyl or phenethyl group which may have a substituent, an aryl group such as a phenyl group or a naphthyl group which may have a substituent) or —CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ are hydrogen atoms, which may have a substituent an alkyl group such as methyl group and ethyl group, which may have a substituent group benzyl group, naphthylmethyl group or a phenethyl group, Aralkyl group or substituent a phenyl group which may have a of an aryl group such as a naphthyl group, which may be the same or different from each other.) Further, X ₂ is identical to X ₁ of the formula 10 Represents a substituent, a single bond, or an alkylene group. However, Y, at least one oxycarbonyl group in X _2, cyano, an alkenylene group, and an 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 phenyl group and a naphthyl group, an aralkyl group such as a benzyl group and a phenethyl group, and the like.
Among these radical polymerizable functional groups, 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、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を表す。）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい。）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、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。〕

[Wherein, R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, A group, an alkoxy group, —COOR ₇ (R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. ), A halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group which may be the same or different, and Ar ₁ and Ar ₂ represent 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 may be the same or different. 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. 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. ]

Specific examples of the substituents in the 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 may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) an alkyl group;
_Preferably, C 1 _{-C 12} especially _C 1 -C _8, more preferably a straight or branched alkyl group of _C 1 -C _4, in the alkyl group a fluorine atom, a hydroxyl group, a cyano group, C ₁ -C ₄ alkoxy group which may have a phenyl group or a halogen _atom, C 1 -C ₄ alkyl or _C 1 -C ₄ phenyl group substituted with an alkoxy group.
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 );
(In the formula, R ₂ represents an 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) aryloxy group;
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) an alkyl mercapto group or an aryl mercapto group;
Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(6) a substituent represented by the following formula;

（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。
（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 _C 1 -C ₄ alkoxy _groups, C 1 -C good .R ₃ and _{R 4} may contain as alkyl group or a halogen atom substituents ₄ may be linked to form a ring.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

Examples of the arylene group represented by Ar ₁ and Ar ₂ include 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, and these alkylene groups include 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 alkyleneoxy groups such as ethyleneoxy group and propyleneoxy group, alkylenedioxy groups derived from ethylene glycol, propylene glycol, and the like, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the like. Examples thereof include a derived di- or poly (oxyalkylene) oxy group, and the alkylene group of the alkylene ether group may have a substituent such as a hydroxyl group, a methyl group, or an ethyl group.
Examples of the vinylene group include substituents represented by the following general formula.

〔式中、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。

[Wherein, R ₅ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2, b represents 1-3. ]
Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether 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（３）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、一般式（Ａ）で示される電荷輸送性構造を有しないラジカル重合性モノマー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１官能の電荷輸送性構造を有するラジカル重合性化合物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 general formula (3), compounds having a methyl group or an ethyl group are particularly preferable as substituents for Rb and Rc.
The radically polymerizable compound having a monofunctional charge transport structure of the above general formulas (1) and (2), particularly (3) used in the present invention is polymerized by releasing the carbon-carbon double bond on both sides. Therefore, in the polymer which is not a terminal structure but is incorporated in a chain polymer and crosslinked by polymerization with a radical polymerizable monomer having no charge transporting structure represented by the general formula (A), Present in the main chain of the polymer and present in the cross-linked chain between the main chain and the main chain (this cross-linked chain includes an intermolecular cross-linked chain between one polymer and another polymer, and one polymer There is an intramolecular cross-linked chain that crosslinks the site of the main chain folded inside and the other site derived from the polymerized monomer at a position away from the main chain in the main chain) Suspended from the chain, whether present or in a cross-linked chain The triarylamine structure has at least three aryl groups arranged radially from the nitrogen atom and is bulky, but is not directly bonded to the chain part but suspended from the chain part via a carbonyl group or the like. Therefore, since these triarylamine structures can be arranged in the polymer in a space that is reasonably adjacent to each other, the structural distortion in the molecule is small. In addition, when the surface layer of the electrophotographic photosensitive member is used, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport path can be adopted.
Specific examples of the radically polymerizable compound having a monofunctional charge transporting structure of the present invention are shown below, but are not limited to the compounds having these structures.

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

  The surface layer of the present invention is a cross-linked surface layer obtained by curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. 1 to 4 functional radically polymerizable monomers and radically polymerizable oligomers 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 friction coefficient reduction. Can be used together. This combined use improves the smoothness of the coating film by reducing the viscosity of the radically polymerizable monomer or surface layer coating liquid that does not have a charge transporting structure, and as a result, smoothes the crosslinked surface layer and reduces distortion. This leads to improved cleaning properties and crack suppression in actual use. For this reason, a combination of trifunctional radically polymerizable monomers is preferred. As these radical polymerizable monomers and oligomers, known ones can be used, and the ratio of these radical polymerizable monomers and oligomers is preferably 1 to 80% by weight, more preferably 5 to 60%, based on the total amount of the crosslinked surface layer. % By weight, more preferably 10 to 40% by weight. Furthermore, the viscosity of these radical polymerizable monomers is preferably 1000 mPa · s and 25 ° C. or less, more preferably 800 mPa · s and 25 ° C. or less.

Although the following are illustrated as a 1-4 functional radically polymerizable monomer, It is not limited to these compounds.
Ethyleneoxy modification is abbreviated as EO, propyleneoxy modification is abbreviated as PO, epichlorohydrin modification is abbreviated as ECH, and alkylene modification is abbreviated as HPA.

  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, ECH modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol Triacrylate, EO-modified glycerol tria Relate, PO-modified glycerol triacrylate, tris (acryloxyethyl) isocyanurate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified Phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol Acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyla Relate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F di Acrylate, neopentyl glycol diacrylate, etc. Rupropane triacrylate (TMPTA), HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and ECH-modified trimethylolpropane triacrylate are preferred for the reasons described above.

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

  Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers. However, 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 150 parts by weight or less, preferably 100 parts by weight or less with respect to 100 parts by weight of the radically polymerizable monomer having no charge transporting structure represented by the general formula (A). The

  The surface layer of the present invention is a crosslinked surface obtained by simultaneously curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. Although it is a layer, a polymerization initiator may be used in the crosslinked surface layer in order to efficiently advance the crosslinking reaction as necessary.

  Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( Peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, peroxide initiators such as lauroyl peroxide, azobisisobutylnitrile, azobiscyclohexanecarbonitrile Azo initiators such as methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid.

Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned. Moreover, what has a photopolymerization 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.

  The surface layer of the present invention is a crosslinked surface layer obtained by simultaneously curing at least a radically polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radically polymerizable compound having a charge transporting structure. However, in addition to this, filler fine particles can be contained for the purpose of improving wear resistance.

The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of the light transmittance and wear resistance of the surface layer. When the average primary particle size of the filler is less than 0.01 μm, it causes a decrease in dispersibility and the effect of improving the wear resistance is not sufficiently exhibited. 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 thus the better. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

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

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

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

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

The crosslinked surface layer of the present invention is coated with a coating liquid containing a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a monofunctional radical polymerizable compound having a charge transporting structure, It is formed by curing.
In the case where 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. And ethers 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 to be 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. When 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.

Hereinafter, the present invention will be described according to 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 shows a photoreceptor having a laminated structure in which a charge generation layer having a charge generation function and a charge transport layer having a charge transport material function are laminated on a conductive support. 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 having a laminated structure>
(Charge generation layer)
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.
Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide. These binder resins can be used alone or as a mixture of two or more. In addition to the binder resin described above as a binder resin for the charge generation layer, a polymer charge transport material having a charge transport function, such as an arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, 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. No. 1, JP-A 09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 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 (charge transport property represented by the general formula (A)) is formed on the charge generation layer as described in the above cross-linked surface layer preparation method. Apply a coating solution containing a radically polymerizable monomer having no structure and a monofunctional radically polymerizable compound having a charge transporting structure; the same shall apply hereinafter), and if necessary, start a curing reaction by external energy after drying. 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. As described above, the use of the polymer charge transport material can reduce the solubility of the lower layer when the surface layer is applied, and is particularly useful.

Examples of the binder resin include 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, a coating method similar to 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 the plasticizer that can be used in combination with the lower layer portion of the charge transport layer, those used as general resin plasticizers such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is based on 100 parts by weight of the binder resin. 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 suitably 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. When the thickness is less than 1 μm, the durability varies due to uneven film thickness, and when the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased and the reproducibility of the image is deteriorated 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 cross-linked surface layer having the charge transport structure of the present invention has a single layer structure by containing a charge generation material having a charge generation function. 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 liquid containing a radical polymerizable composition, applied onto the charge generation layer, dried as necessary, and then external energy. By this, the curing reaction is started 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, it is possible to provide an intermediate layer for the purpose of suppressing mixing of lower layer components into the crosslinked surface layer or improving adhesion with the lower layer. is there. This intermediate layer prevents inhibition of the curing reaction and unevenness of the crosslinked surface layer caused by mixing of the lower photosensitive layer composition in the outermost surface layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the lower photosensitive layer and the surface cross-linked layer.
In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method is employed as described above. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

<About the undercoat layer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.
These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

<Addition of antioxidant to each layer>
Further, in the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, in particular, a crosslinked surface layer, a charge generation layer, a charge transport layer, an undercoat layer, an intermediate layer, etc. Antioxidants can be added to each layer.
The following are mentioned as antioxidant which can be used for this invention.
(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.
In the image forming method and the image forming apparatus of the present invention, the present invention uses a photoconductor having a smooth charge transporting cross-linked surface layer. For example, at least after the photoconductor is charged, exposed to an image, and developed, the image is held. This involves a process of transferring a toner image to a body (transfer paper), fixing and cleaning of the surface of the photosensitive member. It does not necessarily have a process.

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. If this is developed with toner of negative (positive) polarity (detection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained.
Next, the transfer charger (10) is used to transfer the toner image visualized on the photosensitive member onto the transfer member (9). In addition, a pre-transfer charger (7) may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.
Next, a separation charger (11) and a separation claw (12) are used as means for separating the transfer body (9) from the photoreceptor (1). As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger (11), the charging means can be used.
Next, a fur brush (14) and a cleaning blade (15) are used to clean the toner remaining on the 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 photoconductor (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 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 the cross-linked surface layer and at least one of charging, developing, transferring, cleaning, and charge eliminating means are integrated.
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 purification was performed 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２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 2)
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.
In the examples, the viscosity of the radical polymerizable monomer was measured using a TVE-20H, TVE-20L viscometer (manufactured by Tokimec Co., Ltd.).
Example 1
An undercoating layer coating solution, a charge generation layer coating solution, and a charge transporting layer coating solution having the following composition are sequentially applied by dip coating on an aluminum cylinder having an outer diameter of 30 mm, dried, and 3.5 μm below. A pulling layer, a 0.2 μm charge generation layer, and a 23 μm charge transport layer were formed.
・ Coating liquid for undercoat layer 6 parts alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide (CR-EL: Ishihara Sangyo) 40 parts Methyl ethyl ketone 50 parts ・ Coating liquid for charge generation layer 2.5 parts of bisazo pigment with the following structure

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ製） ０．５部
シクロヘキサノン ２００部
メチルエチルケトン ８０部
・電荷輸送層用塗工液
ビスフェーノルＺ型ポリカーボネート １０部
（パンライトＴＳ−２０５０、帝人化成製）
下記構造の低分子電荷輸送物質 ７部

Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 parts Cyclohexanone 200 parts Methyl ethyl ketone 80 parts ・ Coating liquid for charge transport layer 10 parts of bisphenol Z type polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals)
7 parts low molecular charge transport material with the following structure

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：５００ｍＷ／ｃｍ^２、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、本発明の電子写真感光体を得た。
・架橋表面層塗工液
電荷輸送性構造を有さないラジカル重合性モノマー ９５部
ジペンタエリスリトールヘキサアクリレート
（ヘキサアクリレートとペンタアクリレートの重量比１：１混合物；
ＫＡＹＡＲＡＤ ＤＰＨＡ、日本化薬製、粘度：６２００ｍＰａ・ｓ，２５℃）

Tetrahydrofuran 100 parts 1% silicone oil in tetrahydrofuran 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following constitution, light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , irradiation time: 20 seconds, and further 130 ° C. Was dried for 30 minutes to provide a crosslinked surface layer of 4.0 μm to obtain an electrophotographic photosensitive member of the present invention.
-Crosslinked surface layer coating solution Radical polymerizable monomer having no charge transporting structure 95 parts Dipentaerythritol hexaacrylate (1: 1 weight ratio mixture of hexaacrylate and pentaacrylate;
(KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., viscosity: 6200 mPa · s, 25 ° C.)

（ａ＝５、ｂ＝１の化合物と、ａ＝６、ｂ＝０の化合物の重量比１：１混合物）
１官能の電荷輸送性構造を有するラジカル重合性化合物 ９５部
（例示化合物Ｎｏ．５４）
光重合開始剤 １０部
１−ヒドロキシ−シクロヘキシル−フェニル−ケトン
（イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）
テトラヒドロフラン １２００部

(1: 1 weight ratio mixture of a = 5, b = 1 compound and a = 6, b = 0 compound)
95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 1200 parts

Example 2
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-60, manufactured by Nippon Kayaku,
(Viscosity: 1400 mPa · s, 25 ° C.) 95 parts

Example 3
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following.
EO-modified dipentaerythritol hexaacrylate (KAYARAD DPEA-12, manufactured by Nippon Kayaku,
(Viscosity: 1800 mPa · s, 25 ° C.) 95 parts

（但しｎの平均値は１２である。）

(However, the average value of n is 12.)

Example 4
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
Radical polymerizable monomer having no charge transporting structure (two mixed monomers using the following (1) and (2) in a weight ratio of 1: 1,
Viscosity: 430 mPa · s, 25 ° C.) 95 parts (1) Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, manufactured by Nippon Kayaku,
(Viscosity: 1700 mPa · s, 25 ° C)

（２）トリメチロールプロパントリアクリレート
（ＴＭＰＴＡ、東京化成製、粘度：１０５ｍＰａ・ｓ，２５℃）

(2) Trimethylolpropane triacrylate (TMPTA, manufactured by Tokyo Chemical Industry, viscosity: 105 mPa · s, 25 ° C.)

Example 5
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
Radical polymerizable monomer having no charge transporting structure (two mixed monomers using the following (1) and (2) in a weight ratio of 1: 1,
Viscosity: 750 mPa · s, 25 ° C.) 95 parts (1) Dipentaerythritol hexaacrylate (a 1: 1 mixture by weight of hexaacrylate and pentaacrylate;
(KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., viscosity: 6200 mPa · s, 25 ° C.)

（a＝５、ｂ＝１の化合物と、a＝６、ｂ＝０の化合物の重量比１：１混合物）
（２）トリメチロールプロパントリアクリレート
（ＴＭＰＴＡ、東京化成製、粘度：１０５ｍＰａ・ｓ，２５℃）

(1: 1 weight ratio mixture of a = 5, b = 1 compound and a = 6, b = 0 compound)
(2) Trimethylolpropane triacrylate (TMPTA, manufactured by Tokyo Chemical Industry, viscosity: 105 mPa · s, 25 ° C.)

Example 6
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following. .
Radical polymerizable monomer having no charge transporting structure (two mixed monomers using the following (1) and (2) in a weight ratio of 1: 1,
Viscosity: 3300 mPa · s, 25 ° C.) 95 parts (1) Dipentaerythritol hexaacrylate (a 1: 1 mixture by weight of hexaacrylate and pentaacrylate);
KAYARAD DPHA, manufactured by Nippon Kayaku,
(Viscosity: 6200 mPa · s, 25 ° C.)

（a＝５、ｂ＝１の化合物と、a＝６、ｂ＝０の化合物の重量比１：１混合物）
（２）カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（ＫＡＹＡＲＡＤ ＤＰＣＡ−１２０、日本化薬製、
粘度：１７００ｍＰａ・ｓ，２５℃）

(1: 1 weight ratio mixture of a = 5, b = 1 compound and a = 6, b = 0 compound)
(2) Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, manufactured by Nippon Kayaku,
(Viscosity: 1700 mPa · s, 25 ° C)

Example 7
In Example 1, the radical polymerizable compound having the charge transporting structure contained in the crosslinked surface layer coating solution is exemplified as No. 1. An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the number was changed to 16.

Example 8
In Example 1, the radical polymerizable compound having the 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 9
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 liquid Radical polymerizable monomer having no charge transporting structure 90 parts Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-120, manufactured by Nippon Kayaku,
(Viscosity: 1700 mPa · s, 25 ° C)

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 ９０部
（例示化合物Ｎｏ．５４）
光重合開始剤 ２０部
１−ヒドロキシ−シクロヘキシル−フェニル−ケトン
（イルガキュア１８４、チバ・スペシャルティ・ケミカルズ製）
テトラヒドロフラン ９０部
フィラー微粒子 ２０部
アルミナフィラー（ＡＡ０３、住友化学製）

90 parts of a monofunctional radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 20 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran 90 parts Filler fine particles 20 parts Alumina filler (AA03, manufactured by Sumitomo Chemical)

Comparative Example 1
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure was not added in Example 1.

Comparative Example 2
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was used as the following material.
95 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、
粘度：７ｍＰａ・ｓ，２５℃
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,
Viscosity: 7 mPa · s, 25 ° C
Molecular weight: 212
Functional group number: bifunctional Molecular weight / functional group number = 106

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 compound having a charge transporting structure contained in the crosslinked surface layer coating solution in Example 1 was changed to the following materials.
95 parts of a radically polymerizable compound having a charge transporting structure represented by the following structural formula

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.
10 parts of charge transport material of the following structural formula

Comparative Example 6
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.

Comparative Example 7
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 Radical polymerizable monomer having no charge transporting structure 5 parts Dipentaerythritol hexaacrylate (1: 1 weight ratio mixture of hexaacrylate and pentaacrylate;
(KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd., viscosity: 6200 mPa · s, 25 ° C.)

（a＝５、ｂ＝１の化合物と、a＝６、ｂ＝０の化合物の重量比１：１混合物）
下記構造式の電荷輸送性物質：２０部

(1: 1 weight ratio mixture of a = 5, b = 1 compound and a = 6, b = 0 compound)
Charge transport material having the following structural formula: 20 parts

光重合開始剤 ０．１５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）
ポリカーボネート樹脂（ビスフェノールＡ型） １５部
モノクロロベンゼン ３００部

Photopolymerization initiator 0.15 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Polycarbonate resin (bisphenol A type) 15 parts Monochlorobenzene 300 parts

As described above, the surface roughness Ra (JIS B0601: 1982 standard: centerline surface roughness) was measured using Surfcom 1400D (manufactured by Tokyo Seimitsu) for the surface roughness of the electrophotographic photosensitive member produced in Examples 1-9. did. The photoreceptor of Example 1 is 0.23 μm, the photoreceptor of Example 2 is 0.21 μm, the photoreceptor of Example 3 is 0.22 μm, the photoreceptor of Example 4 is 0.07 μm, and the photoreceptor of Example 5 Is 0.08 μm, the photoreceptor of Example 6 is 0.18 μm, the photoreceptor of Example 7 is 0.25 μm, the photoreceptor of Example 8 is 0.28 μm, and the photoreceptor of Example 9 is 0.24 μm. All have good smoothness, and in particular, Examples 4 and 5 were particularly good.
Similarly, the prepared electrophotographic photosensitive member is mounted on an electrophotographic process cartridge, and the dark portion potential 700 is set on a Ricoh IPSiO Color 7100 using an AC non-contact roller type charging method and a 655 nm semiconductor laser as an image exposure light source. After setting to (−V), a total of 50,000 sheets were continuously passed through the actual machine, and the wear amount and the in-machine potential were evaluated. The results are shown in Table 5. Further, Examples 1, 2, and 4 and Comparative Examples 2, 4, and 7 were subjected to a crack acceleration test of the photosensitive layer. As an evaluation method, finger oil was attached to the surface of the electrophotographic photosensitive member, and after standing at 50 ° C. and normal pressure for 3 days, the crystallization state of the photosensitive layer was observed. The results are shown in Table 6.

As is clear from the results of Table 5, in all of the comparative examples, it was impossible to achieve both improvement of wear resistance over a long period of time and maintenance of high quality images.
Further, from Table 6, the crosslinked surface layer is formed by curing a radical polymerizable monomer having no charge transporting structure represented by the general formula (A) and a radical polymerizable compound having a monofunctional charge transporting structure. It can be seen that no cracks are generated in the electrophotographic photoreceptor, and the compound having a charge transporting structure in the crosslinked film is uniformly taken into the crosslinked film. As a result, it can be seen that the long-term wear resistance is improved and the high-quality image output is maintained.
Further, the electrophotographic photoreceptors of Examples 4 and 5 were mounted on Ricoh IPSiO Color 7100 using a small particle diameter toner having a volume average particle diameter of 4.5 μm, and a cleaning property test was performed. In the test method, the cloth was pressed against the downstream side of the cleaning blade, and the amount of toner adhering to the cloth after a certain period of time was measured with a Macbeth reflection densitometer. As a result, the photoreceptors of Examples 4 and 5 were found to have good cleaning properties.

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 (6)

In an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer has at least a radical polymerizable monomer having no charge transport structure represented by the following general formula (A) and the following general formula: An electrophotographic photosensitive member formed by curing a radically polymerizable compound having a monofunctional charge transporting structure represented by (3) .

(Wherein R ₇₁ , R ₇₂ , R ₇₃ , R ₇₄ , R ₇₅ , R ₇₆ represent the following general formula (B) , and R ₇₇ represents a single bond, an alkylene group, an alkylene ether group, or an alkyleneoxycarbonyl group. And R ₇₈ represents hydrogen or a methyl group.)

(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. ) 2. The electrophotographic photosensitive member according to claim 1 , wherein the curing means for the surface layer is a heating or light energy irradiation means. The charge generating layer photosensitive layer from the support side, a charge transport layer, the electrophotographic photosensitive member according to claim 1 or 2, characterized in that a laminated structure of a cross-linked surface layer. Using an electrophotographic photosensitive member according to any one of claims 1 to 3, at least charging, image exposure, development, image forming method characterized by repeating the transfer. An image forming apparatus, comprising an electrophotographic photosensitive member according to any one of claims 1 to 3. An electrophotographic photosensitive member according to any one of claims 1 to 3 , 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 detachable from the forming apparatus main body.

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