JP4160512B2 - 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 provides an electronic device having high durability and high image quality over a long period of time by using a photosensitive layer having good film surface properties, high wear resistance, and good electrical characteristics. The present invention relates to a photographic photoreceptor. 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, in order to improve the cleaning performance as the toner particle size is reduced, the rubber hardness of the cleaning blade and the contact pressure must be increased, which also reduces the wear of the photoreceptor. It is a factor to promote. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.

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

Furthermore, a photoreceptor containing a polyfunctional acrylate monomer cured product in order to improve the abrasion resistance and scratch resistance of (1) is also known (see Patent Document 4). However, in this photoreceptor, although there is a description that the polyfunctional acrylate monomer cured product is contained in the protective layer provided on the photosensitive layer, the protective layer may contain a charge transport material. However, when the surface layer contains a low-molecular charge transport material, there is a problem of compatibility with the cured product. In some cases, the molecular charge transport material is precipitated and the cloudiness phenomenon occurs, and the mechanical strength is also lowered.
Furthermore, since this photoconductor specifically reacts with a monomer in a state containing a polymer binder, curing does not proceed sufficiently, and there is a problem of compatibility between the cured product and the binder resin. There was a tendency for surface irregularities due to phase separation to cause poor cleaning.

  As an alternative to the wear resistance technology of the photosensitive layer, 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 is used. 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 distortion occurs in the cured product, resulting in high internal stress, resulting in rough surface layers and cracks over time. In some cases, it does not have sufficient durability.

Further, even if it becomes possible to improve the wear resistance of the photoreceptor, high durability is not realized if abnormal images such as image blur and image quality deterioration are likely to occur. In order to reduce the surface energy and the coefficient of friction on the surface of the photoreceptor, a method of adding various lubricants to the surface layer of the photoreceptor is known. A method of incorporating a lubricant such as fluorine-modified silicone oil in the surface layer is disclosed (for example, see Patent Documents 7, 8, and 9).
Although this method is effective in reducing the surface energy of the photoconductor and is effective for cleaning and removing foreign matter, these fluorine-modified silicone oils move to the vicinity of the surface in the process of forming the protective layer. Therefore, the effect is lost at an early stage due to a very small amount of abrasion of the surface layer by repeated use. Therefore, the actual situation is that a sufficient effect is not obtained for high durability.

Various attempts have also been made regarding methods of adding various particulate lubricants to the outermost surface layer of the photoreceptor.
Examples of these include the addition of silicone resin fine particles, fluorine-containing resin fine particles (for example, see Patent Document 10), melamine resin fine particles (for example, see Patent Document 11), and the like. (For example, see Patent Document 12), a method for containing a fluororesin powder in the surface layer (for example, see Patent Document 13), a method for containing silicone fine particles in the surface layer (for example, Patent Document 14, 15), a method of containing cross-linked organic fine particles in the surface layer (see, for example, Patent Documents 16 and 17), a method of containing methylsiloxane resin fine particles in the surface layer (see, for example, Patent Document 18), etc. It has been known. The method of dispersing these particulate lubricants on the surface layer of the photoreceptor is effective in increasing the sustainability of the effect, and is an effective method for improving durability compared to the addition of the silicone oil or the like. I can say that. However, since these photoconductors contain a lubricant in a charge transport layer with insufficient wear resistance, they are initially effective in suppressing adhesion of various substances. Insufficient.
For the above reasons, it cannot be said that a photoreceptor having a cross-linked photosensitive layer obtained by chemically bonding the charge transporting structure in these prior arts has sufficient comprehensive characteristics at present.

JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent No. 3262488 Japanese Patent No. 3194392 JP 2000-66425 A JP 07-295248 A JP-A-7-301936 JP-A-8-082940 JP-A 63-65449 JP-A-60-177349 JP-A-2-143257 Japanese Patent Laid-Open No. 2-144550 Japanese Patent Laid-Open No. 7-128872 Japanese Patent Laid-Open No. 10-254160 JP 2000-010322 A US Pat. No. 5,998,072 JP-A-8-190213

  An object of the present invention is to provide an electrophotographic photosensitive member that has high wear resistance, is stable, has good electrical characteristics, and realizes high image quality over a long period of time. Another object of the present invention is to provide an image forming method, an image forming apparatus, and a process cartridge for an image forming apparatus using a high-performance photoconductor.

As a result of intensive studies, the present inventors have found that in an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, a copolymer containing polyorganosiloxane as a constituent component is formed on the surface layer of the photosensitive layer. By dispersing the surface layer into a crosslinked resin layer obtained by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure, The inventors have found that the object can be achieved, and have accomplished the present invention.

That is, the above-described problem is that (1) “an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support in the present invention is a copolymer containing polyorganosiloxane as a constituent component on the surface layer of the photosensitive layer. dispersed, and the surface layer is characterized by one crosslinked resin layer der Rukoto formed by curing a radical polymerizable compound functional having tri- or more functional radical polymerizable monomer and a charge transport structure without at least a charge transport structure ( 2 ) “The functional group of the tri- or higher functional radical polymerizable monomer having no charge transporting structure used in the surface layer is an acryloyloxy group and / or a methacryloyloxy group. wherein wherein the first (1) the electrophotographic photosensitive member according to claim ', (3) "trifunctional or more radio having no charge transport structure for use in said surface layer Ratio of molecular weight to the number of functional groups in the local polymerizable monomer (molecular weight / number of functional groups) is characterized in that said at 250 or less paragraph (1) or the (2) The electrophotographic photosensitive member according to claim '( 4) "1 functional group of the radical polymerizable compound functional having a charge transport structure for use in the surface layer, said first (1, characterized in that an acryloyloxy group or a methacryloyloxy group) term to the ( 3) the electrophotographic photosensitive member according to any one of Items ", (5) a charge transport structure of a monofunctional radically polymerizable compound having a charge transport structure for use" before Symbol table surface layer is a triarylamine structure 1 with the paragraph (1), second (4) the electrophotographic photosensitive member according to any one of Items "(6)" that is used on the surface layer conductive charge transport structure, characterized in that it is functionality of the Raj Le polymerizable compound, wherein the first (1), characterized in that it is the following general formula (1) or (2) one or more terms to the (5) The electrophotographic photosensitive member according to any one of claim;

〔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。〕」、（７）「前記表面層に用いられる電荷輸送性構造を有する１官能のラジカル重合性化合物が、下記一般式（３）の一種以上であることを特徴とする前記第（１）項乃至第（６）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, Ar ₄ represents a substituted or unsubstituted aryl group, or 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. ] "(7)" radical polymerizable compound monofunctional with that electrostatic charge transport structure employed in the surface layer, said first (1, characterized in that at least one of the following general formula (3) ) To ( 6 ) The electrophotographic photosensitive member according to any one of the items;

（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。）」、（８）「前記表面層に含有される、ポリオルガノシロキサンを共重合体成分として含有する共重合体が、アクリル変性ポリオルガノシロキサンであることを特徴とする前記第（１）項乃至第（７）項のいずれかに記載の電子写真感光体」、（９）「前記表面層に含有されるアクリル変性ポリオルガノシロキサン化合物が、シリコーン主鎖にアクリル重合体をグラフト化させた化合物であることを特徴とする前記第（８）項に記載の電子写真感光体」、（１０）「前記表面層に含有されるアクリル変性ポリオルガノシロキサンが、下記一般式（５）；

Represents. ) ”, ( 8 )“ The copolymer containing polyorganosiloxane as a copolymer component contained in the surface layer is an acrylic-modified polyorganosiloxane, ”the items (1) to the (7) the electrophotographic photosensitive member according to any one of Items ", (9) acryl-modified polyorganosiloxane compound" is contained in the surface layer, a compound obtained by grafting an acrylic polymer to the silicone backbone characterized in that said in first (8) electrophotographic photosensitive member according to claim ', (10) "acrylic-modified polyorganosiloxane contained in said surface layer is a compound represented by the following general formula (5);

〔式中のＲ_２０、Ｒ_２１及びＲ_２２は、それぞれ同一又は異なる炭素数１〜２０の炭化水素基又はハロゲン化炭化水素基、Ｙはラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基、Ｚ_１及びＺ_２は、それぞれ同一又は異なる水素原子、低級アルキル基又は

[In the formula, R ₂₀ , R ₂₁ and R ₂₂ are the same or different, respectively, a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, Y is a radical reactive group, an SH group or an organic group having both. , Z ₁ and Z ₂ are the same or different hydrogen atoms, lower alkyl groups or

基（Ｒ_２３及びＲ_２４は、それぞれ同一又は異なる炭素数１〜２０の炭化水素基又はハロゲン化炭化水素基、Ｒ_２５は炭素数１〜２０の炭化水素基もしくはハロゲン化炭化水素基、あるいはラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基を表わす。）、ｕは１０，０００以下の正の整数、ｖは１以上の整数である〕で表わされるポリオルガノシロキサンと、下記一般式（６）；

Groups (R ₂₃ and R ₂₄ are the same or different, respectively, a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, R ₂₅ is a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, or a radical Represents an organic group having a reactive group and / or an SH group), u is a positive integer of 10,000 or less, and v is an integer of 1 or more], and the following general formula ( 6);

（式中のＲ_２６は水素原子又はメチル基、Ｒ_２７はアルキル基、アルコキシ置換アルキル基、シクロアルキル基又はアリール基を表わす。）
で表わされる（メタ）アクリル酸エステル、又はこの（メタ）アクリル酸エステル１０重量％以上と共重合可能な単量体９０重量％以下との混合物とを、重量比５：９５ないし９５：５の割合で乳化グラフト共重合させてなるアクリル変性ポリオルガノシロキサンであることを特徴とする前記第（８）項又は第（９）項に記載の電子写真感光体」、（１１）「前記表面層に含有されるアクリル変性ポリオルガノシロキサンが、上記一般式（５）で表わされるポリオルガノシロキサンと、上記一般式（６）で表わされる（メタ）アクリル酸エステル、又はこの（メタ）アクリル酸エステル７０重量％以上と共重合可能な単量体３０重量％以下との混合物を、重量比５１：４９ないし９５：５の割合で乳化グラフト共重合させてなるアクリル変性ポリオルガノシロキサンであることを特徴とする前記第（１０）項に記載の電子写真感光体」、（１２）「前記表面層に含有されるアクリル変性ポリオルガノシロキサンが、上記一般式（５）で表わされるポリオルガノシロキサンと、上記一般式（６）で表わされる（メタ）アクリル酸エステル、又はこの（メタ）アクリル酸エステル７０重量％以上と共重合可能な単量体３０重量％以下との混合物とを、重量比６５：３５ないし９５：５の割合で乳化グラフト共重合させて成るアクリル変性ポリオルガノシロキサンであることを特徴とする前記第（１０）項に記載の電子写真感光体」、（１３）「前記一般式（６）の成分として用いる（メタ）アクリル酸エステル、あるいは該（メタ）アクリル酸エステルと前記共重合可能な他の単量体の混合物のポリマー化物のガラス転移温度が２０℃以上であることを特徴とする前記第（１０）項乃至第（１２）項のいずれかに記載の電子写真感光体」、（１４）「前記アクリル変性ポリオルガノシロキサン化合物が粒状に分散されていることを特徴とする前記第（１）項乃至第（１３）項のいずれかに記載の電子写真感光体」、（１５）「前記感光層が支持体側から電荷発生層、電荷輸送層、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（１４）項のいずれかに記載の電子写真感光体」、（１６）「前記感光層の電荷輸送層が高分子電荷輸送物質を含有することを特徴とする前記第（１５）項に記載の電子写真感光体」、（１７）「前記高分子電荷輸送物質がトリアリールアミン構造を主鎖又は側鎖に有するポリカーボネートであることを特徴とする前記第（１６）項に記載の電子写真感光体」、（１８）「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（１７）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（１９）「前記第（１）項乃至第（１８）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（２０）「前記第（１）項乃至第（１８）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（２１）「前記第（１）項乃至第（１８）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。

(In the formula, R ₂₆ represents a hydrogen atom or a methyl group, and R ₂₇ represents an alkyl group, an alkoxy-substituted alkyl group, a cycloalkyl group, or an aryl group.)
Or a mixture of 10% by weight or more of this (meth) acrylic acid ester and 90% by weight or less of a copolymerizable monomer with a weight ratio of 5:95 to 95: 5 The electrophotographic photosensitive member according to item ( 8 ) or ( 9 ), which is an acrylic-modified polyorganosiloxane obtained by emulsion graft copolymerization at a ratio ", ( 11 )" on the surface layer The acrylic-modified polyorganosiloxane contained is a polyorganosiloxane represented by the above general formula (5) and a (meth) acrylic ester represented by the above general formula (6), or this (meth) acrylic ester 70 wt. % And an acrylic graft copolymer obtained by emulsion graft copolymerization in a weight ratio of 51:49 to 95: 5. Said first characterized in that it is a sex polyorganosiloxane (10) The electrophotographic photosensitive member according to claim ', (12) "acrylic-modified polyorganosiloxane contained in said surface layer is the general formula (5) And (meth) acrylic acid ester represented by the above general formula (6), or 30% by weight or less of a monomer copolymerizable with 70% by weight or more of this (meth) acrylic acid ester The electrophotographic photosensitive member according to ( 10 ) above, which is an acrylic-modified polyorganosiloxane obtained by emulsion graft copolymerization of the mixture at a weight ratio of 65:35 to 95: 5. (13) "the use as a component of the general formula (6) (meth) acrylic acid ester or the (meth) the copolymerizable other acrylic acid esters, Wherein said (10) section to the (12) The electrophotographic photosensitive member according to any one of Items glass transition temperature of the polymer product of the mixture of monomers and wherein the at 20 ° C. or more ", (14) "The electrophotographic photosensitive member according to any one of (1) to ( 13 ) above, wherein the acrylic-modified polyorganosiloxane compound is dispersed in a granular form", ( 15 ) The electrophotographic photosensitive member according to any one of (1) to ( 14 ), wherein the layer has a laminated structure of a charge generation layer, a charge transport layer, and a surface layer from the support side. 16 ) “The electrophotographic photosensitive member according to item ( 15 ), wherein the charge transport layer of the photosensitive layer contains a polymer charge transport material”, ( 17 ) “The polymer charge transport material is Triarylamine structure on the main chain or side Electrophotographic photosensitive member "described in the first (16), characterized in that a polycarbonate having the said, which is a (18) curing means" the surface layer is heated or light energy emitting means This can be solved by the electrophotographic photosensitive member according to any one of items (1) to ( 17 ).
Further, the above-mentioned problem is that at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of ( 19 ) and (1) to ( 18 ) of the present invention. The image forming method is characterized in that it is solved.
In addition, the above-described problem is solved by ( 20 ) “an image forming apparatus comprising the electrophotographic photosensitive member according to any one of (1) to ( 18 )” of the present invention. .
In addition, the above-described problems are solved by the electrophotographic photosensitive member according to any one of ( 21 ) and (1) to ( 18 ), a charging unit, a developing unit, a transfer 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 copolymer containing polyorganosiloxane as a constituent component is dispersed in the surface layer of the photosensitive layer, and the surface layer has at least a trifunctional or higher radical having no charge transporting structure. By using a cross-linked resin layer obtained by curing a monofunctional radically polymerizable compound having a polymerizable monomer and a charge transporting structure, it has high wear resistance, good electrical properties, and maintains low surface energy over a long period of time. Thus, a highly durable and high-performance photoconductor can be obtained. Therefore, by using this photoreceptor, it is possible to provide a high-performance and highly reliable image forming process, an image forming apparatus, and a process cartridge for the image forming apparatus that can provide a good image over a long period of time.

Hereinafter, the present invention will be described in detail.
In the present invention, as described above, in the electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, a copolymer containing polyorganosiloxane as a constituent component is dispersed on the surface layer of the photosensitive layer, and the surface layer is Ru 1 crosslinked resin layer by curing a radical polymerizable compound functional Tona having a tri- or more functional radical polymerizable monomer having no at least a charge transport structure charge transport structure. As a result, an electrophotographic photosensitive member that has high wear resistance, is stable, and achieves high image quality over a long period of time is achieved.

The reasons for this are as follows.
The photoreceptor of the present invention uses a tri- or higher functional radical polymerizable monomer in the surface layer, thereby developing a three-dimensional network structure and obtaining a highly hard crosslinked surface layer having a very high degree of crosslinking, High wear resistance is achieved. On the other hand, when only monofunctional and bifunctional radically polymerizable monomers are used, the cross-linking bond in the cross-linked surface layer becomes dilute, and a dramatic improvement in wear resistance cannot be achieved. In addition, when the cross-linked surface layer contains a polymer material, the development of the three-dimensional network structure is hindered and the degree of cross-linking 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 radical polymerizable compound having a charge transporting structure is used in addition to the trifunctional radical polymerizable monomer, which is a trifunctional or higher functional radical polymerization. Is incorporated into the cross-linking during curing of the functional monomer. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the cross-linked surface layer The mechanical strength also decreases.

  Furthermore, in the present invention, the crosslinked surface layer contains a copolymer containing polyorganosiloxane as a constituent component, so that foreign matters such as discharge products, toner external additives, and paper dust are removed from the photoreceptor surface. Easy to remove. This is because the surface energy of the photoreceptor is lowered and the releasability is improved. Further, when the polyorganosiloxane copolymer is, for example, an acrylic-modified polyorganosiloxane compound, the compatibility with the above-mentioned radical polymerizable monomer is further improved, and in the obtained crosslinked film, polyorganosiloxane is obtained. The cohesiveness of the copolymer is remarkably lowered and the dispersibility is greatly improved, and the surface smoothness of the photoreceptor is remarkably improved, so that both wear resistance and low surface energy can be realized.

Furthermore, the photoconductor in the present invention can maintain the effect of reducing the surface energy even after repeated use, and thereby adhere to the surface of the photoconductor to prevent the occurrence of foreign matter that causes abnormal images. The removal effect can be maintained over a long period of time, and high image quality can be stabilized. In addition, the effect on the transfer efficiency and the cleaning property is stably maintained over a long period of time. In particular, the primary particles of the acryl-modified polyorganosiloxane produced by emulsion polymerization can form nano-order ultrafine particles, and have good compatibility with the crosslinked resin of the present invention, and aggregates. The ultrafine particle state can be present in the crosslinked film without forming.
When the conventional particulate lubricant is dispersed in the cross-linked resin, the dispersibility becomes insufficient, and the additive effect of the lubricant will vary locally, but in the case of using the above acrylic-modified polyorganosiloxane Can be dispersed uniformly in the layer in an ultrafine particle state, thereby reducing variations in the surface energy reduction effect on the entire surface of the photoreceptor, and improving the uniformity of the effect, Thereby, the stability of the effect can be greatly improved. The acrylic-modified polyorganosiloxane has a more effective structure for enhancing compatibility with the crosslinked resin by graft copolymerization with the siloxane chain as the main chain and the acrylic chain as the side chain. It is thought that there is. This not only further improves dispersibility and orientation, but also enables the siloxane polymerization ratio to be significantly increased while maintaining it, which is effective for improving the stability of the effect. It is thought that it was.
As a result, discharge products, toner additives, paper dust, and other foreign substances that adhere to the surface of the photoreceptor are less likely to adhere to or are easy to remove even if adhered, and the stability of the effect is greatly enhanced. As a result, not only image blur is suppressed, but transfer efficiency, cleaning performance, abnormal images due to filming and foreign matter adhesion, and abrasion resistance are improved, resulting in higher durability and higher image quality. Has many effects.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
The trifunctional or higher functional radical polymerizable monomer having no charge transporting property used in the present invention is a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group. And a monomer having no electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having three or more radical polymerizable functional groups. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization.
Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formulas.

〔ただし、式中、Ｘ_１は、置換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わす。）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り、３個以上のアクリロイルオキシ基を有する化合物は、例えば水酸基がその分子中に３個以上ある化合物とアクリル酸（塩）、アクリル酸ハライド、アクリル酸エステルを用い、エステル反応あるいはエステル交換反応させることにより得ることができる。また、３個以上のメタクリロイルオキシ基を有する化合物も同様にして得ることができる。また、ラジカル重合性官能基を３個以上有する単量体中のラジカル重合性官能基は、同一でも異なっても良い。

[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) Represents 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 phenethyl, Aralkyl group or an optionally substituted phenyl group, etc., an aryl group such as phenyl or naphthyl, which may be the same or different from each other.) Further, X ₂ and X ₁ of the formula 10 It represents the same substituent, single bond, and alkylene group. However, Y, at least one oxycarbonyl group in X _2, a cyano group, an alkenylene group, and an aromatic ring. ]
Specific examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.
In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ , and Y include, for example, a halogen atom, a nitro group, a cyano group, a methyl group, an alkyl group such as an ethyl group, a methoxy group, an ethoxy group, and the like And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.
Among these radical polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful, and a compound having three or more acryloyloxy groups is, for example, a compound having three or more hydroxyl groups in the molecule and an acrylic group. It can be obtained by using an acid (salt), an acrylic acid halide, or an acrylic ester to cause an ester reaction or a transesterification reaction. A compound having three or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

Specific examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure include the following, but are not limited to these compounds.
That is, examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and PO-modified. Trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH-modified glycerol triacrylate, EO-modified glycerol triacrylate , PO-modified glycerol triacrylate, Lith (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl Modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, etc. These may be used alone or in combination of two or more.

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

The monofunctional radically polymerizable compound having a charge transporting structure used in the present invention is a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, It refers to a compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having one radical polymerizable functional group. Examples of the radical polymerizable functional group include those shown in the above radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. Further, triarylamine structure is effective high KuYoshimi preferable as charge transport structure. Furthermore, when a compound represented by the structure of the following general formula (1) or (2) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.

〔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）、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, Group, alkoxy group, —COOR ₇ (R ₇ is 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), halogen Carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ may 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 a good aryl group, which may be the same or different from each other, and Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, which may be the same or different. Ar _3, Ar ₄ represents a substituted or unsubstituted aryl group, or 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, as (asym) -Indacenyl group, s (sym) -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, chrycenyl group, naphthacenyl group and the like.

  Examples of the non-condensed 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
（８）置換又は無置換のスチリル基、置換又は無置換のβ−フェニルスチリル基、ジフェニルアミノフェニル基、ジトリルアミノフェニル基等。

(In the formula, R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these may form a ring _C 1 -C ₄ alkoxy _groups, C 1 -C a alkyl group or a halogen atom ₄ which may contain as substituents .R ₃ and _{R 4} jointly)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) alkylenedioxy group or alkylenedithio group such as methylenedioxy group or methylenedithio group (8) substituted or unsubstituted styryl group, substituted or unsubstituted β-phenylstyryl group, diphenylaminophenyl group, ditolyl Aminophenyl group and the like.

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

Represents. ]
As the compound represented by the general formula (3), compounds having a methyl group or an ethyl group as substituents for Rb and Rc are particularly preferable.
The general formula for use in the present invention (1) and (2), in particular (3) radically polymerizable compound of monofunctional with electrostatic charge transport structure, carbon - is double bond between carbons is open on both sides polymerization Therefore, in the polymer that does not become a terminal structure, is incorporated in the chain polymer, and is crosslinked by polymerization with a tri- or higher functional radical polymerizable monomer, it exists in the main chain of the polymer, and Present in the main chain-cross-linked chain (this cross-linked chain has an intermolecular cross-linked chain between one polymer and another polymer, and a main chain folded in one polymer. There is an intramolecular cross-linked chain that crosslinks the site and another site derived from the polymerized monomer at a position away from this in the main chain), but even if it exists in the main chain, Even if present in the triarylamine structure suspended from the chain portion, the nitrogen atom It has at least three aryl groups arranged in the radial direction and is bulky, but is not directly bonded to the chain part, but is suspended from the chain part via a carbonyl group, etc. Since these triarylamine structures can be arranged adjacent to each other in the polymer, there is little structural distortion in the molecule, and the surface of the electrophotographic photosensitive member is also fixed. In the case of a layer, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport pathway can be adopted.
Specific examples of the monofunctional radically polymerizable compound having a photoelectric charge transport structure of the present invention are shown below, but the invention is not limited to the compounds of these structures.

As a reference example, it shows the specific example of the bifunctional radically polymerizable compound having a charge transport structure below.

As a reference example, it shows the specific example of a trifunctional radically polymerizable compound having a charge transport structure below.

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 contained in an amount of 20 to 80% by weight based on the crosslinked resin. Preferably it is 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 trifunctional monomer having no charge transport structure is lowered, and the crosslink density is lowered, so that high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but the range of 30 to 70% by weight is most preferable in consideration of the balance of both characteristics.

The surface layer of the present invention is obtained by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a monofunctional radical polymerizable compound having a charge transport structure, and an acrylic-modified polyorganosiloxane. In addition to this, monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are used in combination for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the crosslinked surface layer, lower surface energy and friction coefficient reduction. can do. Known radical polymerizable monomers and oligomers can be used.

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

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

Examples of the functional monomer include those substituted with a fluorine atom such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, No. 60503, JP-B-6-45770, siloxane repeating units: 20-70 acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl polydimethylsiloxane Examples include vinyl monomers having a polysiloxane group such as diethyl, acrylates and methacrylates.
Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers. However, when a large amount of monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the cross-linked surface layer is substantially reduced, resulting in a decrease in wear resistance. For this reason, the content of these monomers and oligomers is limited to 50 parts by weight or less, preferably 30 parts by weight or less, with respect to 100 parts by weight of the tri- or higher functional radical polymerizable monomer.

The surface layer of the present invention is obtained by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure. In order to advance this crosslinking reaction efficiently, a polymerization initiator may be used in the crosslinked surface layer.

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

Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.
These polymerization initiators may be used alone or in combination of two or more. The content of the polymerization initiator is 0.5 to 40 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total content having radical polymerizability.

  Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. As these additives, known additives can be used, and as plasticizers, those 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, 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 present invention, a copolymer containing polyorganosiloxane as a constituent component is dispersed in the surface layer of the photosensitive layer. Examples of the copolymer include acrylic modified polyorganosiloxane, styrene modified polyorganosiloxane, Epoxy modified polyorganosiloxane, polyether modified polyorganosiloxane, polyglycerin modified polyorganosiloxane, alkyd resin modified polyorganosiloxane, polyester modified polyorganosiloxane, methacryloxypropyl modified polyorganosiloxane, fluorine modified polyorganosiloxane, polyoxyethylene / Polyorganosiloxane copolymer, polyoxypropylene / polyorganosiloxane copolymer, etc. can be used, and among them, acrylic modified polyorganosiloxane It is preferred.
This acrylic-modified polyorganosiloxane has the following general formula (5)

〔式中、Ｒ_２０、Ｒ_２１及びＲ_２２は、それぞれ同一又は異なる炭素数１〜２０の炭化水素基又はハロゲン化炭化水素基、Ｙはラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基、Ｚ_１及びＺ_２は、それぞれ同一又は異なる水素原子、低級アルキル基又は

[Wherein R ₂₀ , R ₂₁ and R ₂₂ are the same or different hydrocarbon groups or halogenated hydrocarbon groups having 1 to 20 carbon atoms, Y is a radical reactive group, an SH group or an organic group having both, , Z ₁ and Z ₂ are the same or different hydrogen atoms, lower alkyl groups or

基（式中、Ｒ_２３及びＲ_２４は、それぞれ同一又は異なる炭素数１〜２０の炭化水素基又はハロゲン化炭化水素基、Ｒ_２５は炭素数１〜２０の炭化水素基もしくはハロゲン化炭化水素基、あるいはラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基を表す。）、ｕは１０，０００以下の正の整数、ｖは１以上の整数を表わす。〕で表わされるポリオルガノシロキサンと、下記一般式（６）

Group (wherein R ₂₃ and R ₂₄ are the same or different, respectively, a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, and R ₂₅ is a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms. Or an organic group having a radical reactive group or an SH group or both.), U is a positive integer of 10,000 or less, and v is an integer of 1 or more. And a polyorganosiloxane represented by the following general formula (6)

（式中、Ｒ_２６は水素原子又はメチル基、Ｒ_２７はアルキル基、アルコキシ置換アルキル基、シクロアルキル基又はアリール基を表わす。）
で表わされる（メタ）アクリル酸エステル及び所望に応じて用いられる共重合可能な単量体を、乳化重合法によりグラフト重合させることにより製造される。

(In the formula, R ₂₆ represents a hydrogen atom or a methyl group, and R ₂₇ represents an alkyl group, an alkoxy-substituted alkyl group, a cycloalkyl group, or an aryl group.)
(Meth) acrylic acid ester represented by the formula (1) and a copolymerizable monomer used as desired are produced by graft polymerization using an emulsion polymerization method.

The substituents of the polyorganosiloxane represented by the general formula (5) will be described more specifically. R ₂₀ , R ₂₁ and R ₂₂ are each an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group; At least one hydrogen atom bonded to a carbon atom having 1 to 20 carbon atoms or an aryl group such as a phenyl group, tolyl group, xylyl group, naphthyl group or the like or a hydrogen atom bonded to a carbon atom of these hydrocarbon groups is substituted with a halogen atom In the halogenated hydrocarbon group having 1 to 20 carbon atoms, R ₂₀ , R ₂₁ and R ₂₂ may be the same or different from each other. Y is an organic group having a radical reactive group such as a vinyl group, an allyl group, a γ-acryloxypropyl group, a γ-methacryloxypropyl group, a γ-mercaptopropyl group, or an SH group and / or both. . Z ₁ and Z ₂ are a hydrogen atom, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, or

で示されるトリオルガノシリル基であり、このトリオルガノシリル基におけるＲ_２３及びＲ_２４は、それぞれ同一又は異なる炭素数１〜２０の炭化水素基又はハロゲン化炭化水素基、Ｒ_２５は炭素数１〜２０の炭化水素基もしくはハロゲン化炭化水素基、あるいはラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基である。該トリオルガノシリル基における炭素数１〜２０の炭化水素基、ハロゲン化炭化水素基及びラジカル反応性基又はＳＨ基もしくはその両方をもつ有機基としては、前記に例示したものを挙げることができる。該Ｚ_１とＺ_２は、それぞれ同一であってもよいし、互いに異なるものであってもよい。さらに、ｕは１０，０００以下の正の整数、好ましくは５００〜８，０００の範囲の整数であり、ｖは１以上の整数、好ましくは１〜５００の範囲の整数である。

In the triorganosilyl group, R ₂₃ and R ₂₄ are the same or different hydrocarbon groups or halogenated hydrocarbon groups having 1 to 20 carbon atoms, and R ₂₅ is 1 to 3 carbon atoms. An organic group having 20 hydrocarbon groups or halogenated hydrocarbon groups, or radical reactive groups and / or SH groups. Examples of the organic group having a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group, a radical reactive group and / or an SH group in the triorganosilyl group include those exemplified above. Z ₁ and Z ₂ may be the same or different from each other. Further, u is a positive integer of 10,000 or less, preferably an integer in the range of 500 to 8,000, and v is an integer of 1 or more, preferably an integer in the range of 1 to 500.

  The polyorganosiloxane represented by the general formula (5) is a cyclic polyorganosiloxane, a liquid polydimethylsiloxane in which both molecular chain ends are blocked with hydroxyl groups, a liquid polydimethylsiloxane in which both molecular chain ends are blocked with alkoxy groups, Polydimethylsiloxane with both ends of the molecular chain blocked with trimethylsilyl groups, silanes for introducing radical reactive groups and / or SH groups, or hydrolyzed products of silanes, etc., if desired The trifunctional trialkoxysilane in an amount that does not impair the object of the present invention and its hydrolysis product can be used for the reaction.

  Next, different examples of the method for producing the polyorganosiloxane represented by the general formula (5) will be described. First, the first method uses, as a raw material, a cyclic low molecular siloxane such as the above-mentioned octamethylcyclotetrasiloxane, a dialkoxysilane compound having a radical reactive group and / or an SH group, or a hydrolyzate thereof. This is a method for obtaining a high molecular weight polyorganosiloxane by polymerizing in the presence of a strongly alkaline or strongly acidic catalyst. The high molecular weight polyorganosiloxane thus obtained is emulsified and dispersed in an aqueous medium in the presence of a suitable emulsifier in order to be used for the emulsion graft copolymerization in the next step.

  Next, the second method uses, as raw materials, for example, the low molecular polyorganosiloxane, a dialkoxysilane having a radical reactive group and / or an SH group, or a hydrolyzate thereof, and a sulfonic acid-based interface. In this method, emulsion polymerization is carried out in an aqueous medium in the presence of an activator or a sulfate ester surfactant. In this emulsion polymerization, the same raw materials are used, and after emulsifying and dispersing in an aqueous medium with a cationic surfactant such as alkyltrimethylammonium chloride or alkylbenzylammonium chloride, an appropriate amount of potassium hydroxide or sodium hydroxide is obtained. It can also be polymerized by adding a strong alkaline compound such as.

  When the polyorganosiloxane represented by the general formula (5) thus obtained has a low molecular weight, the molded product obtained from the composition is imparted with a slidability and abrasion resistance that are durable. Since the effect becomes inferior, it is preferable that the molecular weight is as large as possible. For this reason, in the first method, it is necessary to leave the polyorganosiloxane of high molecular weight in the polymerization and to emulsify and disperse it, and in the second method, the aging treatment performed after the emulsion polymerization. In this case, since the molecular weight of the polyorganosiloxane increases if the temperature is lowered, the aging temperature is advantageously 30 ° C. or less, preferably 15 ° C. or less.

  In the present invention, examples of the (meth) acrylic acid ester represented by the general formula (6) to be graft-polymerized to the polyorganosiloxane represented by the general formula (5) include methyl (meth) acrylate and ethyl (meth). Acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) Alkyl (meth) acrylates such as acrylate, stearyl (meth) acrylate, alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, cyclohexyl (meth) acrylate Relate, phenyl (meth) acrylate and benzyl (meth) acrylate. These (meth) acrylic acid esters may be used alone or in combination of two or more.

  Moreover, a polyfunctional monomer and an ethylenically unsaturated monomer are mentioned as a copolymerizable monomer used with these (meth) acrylic acid esters as desired. Examples of the polyfunctional monomer include (meth) acrylamide, diacetone (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, and N-methoxymethyl (meth) acrylamide. Ethylenically unsaturated amides and alkylols or alkoxyalkylated products of ethylenically unsaturated amides, oxirane group-containing unsaturated monomers such as glycidyl (meth) acrylate, glycidyl allyl ether, 2-hydroxyethyl (meth) acrylate, 2- Hydroxyl group-containing unsaturated monomers such as hydroxypropyl (meth) acrylate, carboxyl group-containing ethylenically unsaturated monomers such as (meth) acrylic acid, maleic anhydride, crotonic acid and itaconic acid, N-dimethylaminoethyl (Meta) Acry Amino group-containing unsaturated monomers such as N-diethylaminoethyl (meth) acrylate, polyalkylene oxide group-containing unsaturated monomers such as ethylene oxide and propylene oxide adducts of (meth) acrylic acid, ethylene glycol di Examples include (meth) acrylates, diethylene glycol di (meth) acrylates, full esters of polyhydric alcohols such as trimethylolpropane tri (meth) acrylate and (meth) acrylic acid, and allyl (meth) acrylates and divinylbenzene. . These may be used alone or in combination of two or more. These polyfunctional monomers have an effect of imparting elasticity, durability, heat resistance, and the like to the molded body by participating in crosslinking between polymers in the acrylic-modified polyorganosiloxane.

  On the other hand, examples of the ethylenically unsaturated monomer include styrene, α-methylstyrene, vinyl toluene, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl acetate, vinyl propionate, and vinyl versatate. These monomers may be used singly or in combination of two or more, or in combination of one or more of these monomers and one or more of the above functional monomers. May be.

  The amount of the copolymerizable monomer used as desired is 30 based on the total weight of the (meth) acrylic acid ester represented by the general formula (6) and the copolymerizable monomer. It is necessary to select within the range of weight% or less. When this amount exceeds 30% by weight, the miscibility between the resulting acrylic-modified polyorganosiloxane and the binder resin is lowered.

  In addition, the (meth) acrylic acid ester of the general formula (6) component, or the mixture of the (meth) acrylic acid ester and the other copolymerizable monomer described above has excellent slidability and resistance to molding. In order to impart abrasion, it is desirable that the polymerized product has a glass transition temperature of 20 ° C., preferably 30 ° C. or higher.

  The acrylic-modified polyorganosiloxane in the present invention is a polyorganosiloxane of the general formula (5), a (meth) acrylic acid ester of the general formula (6), or other copolymerizable with the (meth) acrylic acid ester. And a mixture of the above monomers in a weight ratio of 5:95 to 95: 5, and obtained by graft copolymerization by an emulsion polymerization method. When the proportion of the polyorganosiloxane of the general formula (5) is less than the above range, the resulting acrylic-modified polyorganosiloxane cannot sufficiently exhibit the effects of the polyorganosiloxane itself, and is a drawback of the acrylic polymer. If it exceeds the above range, the acrylic-modified polyorganosiloxane will be less miscible with the cross-linked membrane resin and will easily bleed on the cross-linked membrane surface, making it slidable and wear resistant. Etc. tend to decrease with time.

In the emulsion graft copolymerization of the component of the general formula (5) and the component of the general formula (6), an aqueous emulsion of polyorganosiloxane is used as the component of the general formula (5), and a normal radical initiator is used. Can be carried out by a known emulsion polymerization method.
The production of acrylic modified polyorganosiloxane is described in detail in Japanese Patent Publication No. 7-5808 (Nisshin Chemical Industry Co., Ltd.).

Below, the typical example of the acrylic modified polyorganosiloxane used by this invention is shown.
For example, Sharine R-170S, R-170, NR-150, NR-130, R-210 from Nissin Chemical Industry Co., Ltd. and X-22-8084, X-22-8171 from Shin-Etsu Chemical Co., Ltd. What is marketed with the brand name.

  In addition, in the acrylic-modified polyorganosiloxane used in the present invention, residual impurities such as an emulsifier and a flocculant used in polymerization may be impaired in an electrophotographic photoreceptor having an electrical property problem. It is preferable to use after purification. Examples of the purification method include a method of stirring and washing with an acid, an aqueous alkali solution, water and alcohol, and a solid-liquid extraction method such as Soxhlet extraction.

  The acrylic modified polyorganosiloxane and the radical polymerizable monomer are mixed together with an organic solvent, and a dispersion treatment is performed as necessary to produce a dispersion. In some cases, it is also possible to use a method in which dispersion is performed with the acrylic-modified polyorganosiloxane and an organic solvent, and then a radical polymerizable monomer is added. Moreover, it is possible to add a charge transport material and various additives to these dispersions as necessary. As the dispersing means, conventionally known dispersing means such as a ball mill, an attritor, a sand mill, a bead mill, ultrasonic waves, high-pressure liquid collision and the like can be used.

  The higher the concentration of acrylic-modified polyorganosiloxane in the surface protective layer, the better because the low surface energy stability is higher. However, if it is too high, the residual potential increases and the hardness of the protective layer decreases, causing side effects. There is a case. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.

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

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

  Since the film thickness of the crosslinked surface layer of the present invention varies depending on the layer structure of the photoreceptor in which the crosslinked surface layer is used, it will be described later together with the layer structure.

  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.

  In the cross-linked surface layer of the present invention, it is necessary to contain a bulky charge transporting structure in order to maintain electrical characteristics and to increase the cross-linking density in order to increase the strength. In such curing after application of the crosslinked surface layer, if very high energy is applied from the outside and the reaction proceeds rapidly, curing proceeds unevenly and the unevenness of the crosslinked film surface becomes severe. For this reason, the thing using the heat | fever which can control reaction rate by heating conditions, the irradiation intensity | strength of light, and the amount of polymerization initiators, or the external energy of light is preferable.

In the case of using the crosslinked surface layer forming material of the present invention, examples of the coating method include, for example, an acrylate monomer having three acryloyloxy groups and a triarylamine compound having one acryloyloxy group as a coating solution. When these are used, their use ratio is 7: 3 to 3: 7, and 3-20% by weight of a polymerization initiator is added to the total amount of these acrylate compounds, and a solvent is added to prepare a coating solution. To do. For example, in the case where the charge transport layer which is the lower layer of the cross-linked surface layer uses a triarylamine donor as the charge transport material and polycarbonate as the binder resin, and the cross-linked surface layer is formed by spray coating, the above coating solution As the solvent, tetrahydrofuran, 2-butanone, ethyl acetate and the like are preferable, and the use ratio thereof is 3 to 10 times the total amount of the acrylate compound.
The cured surface crosslinked layer is preferably insoluble in an organic solvent. A film that is not sufficiently cured is soluble in an organic solvent and has a low crosslink density, so that the mechanical durability is also low.

Next, for example, the prepared coating solution is applied by spraying or the like on a photoreceptor in which an undercoat layer, a charge generation layer, and the charge transport layer are sequentially laminated on a support such as an aluminum cylinder. Thereafter, it is dried at a relatively low temperature for a short time (25 to 80 ° C., 1 to 10 minutes) and cured by UV irradiation or heating.
For UV irradiation, uses a metal halide lamp, illuminance 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, for example, the case of irradiation with UV light of 700 mW / cm ^2, for example upon curing, by rotating the drum All surfaces may be uniformly irradiated for about 200 seconds. At this time, the drum temperature is controlled so as not to exceed 50 ° C.
In the case of thermosetting, the heating temperature is preferably 100 to 170 ° C. For example, when a blowing oven is used as a heating means and the heating temperature is set to 150 ° C, the heating time is 20 minutes to 3 hours.
After the curing is completed, the photosensitive member of the present invention is obtained by heating at 100 to 150 ° C. for 10 to 30 minutes to reduce the residual solvent.

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. FIG. 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, 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 (radical polymerizable monomer having no charge transport structure) of the present invention is formed on the charge generation layer as described in the above cross-linked surface layer preparation method. And a radically polymerizable compound having a charge transporting structure; the same shall apply hereinafter) and an acrylic-modified polyorganosiloxane-containing coating liquid. After drying, if necessary, a curing reaction is initiated by external energy, It 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. Dissolved or dispersed, formed on the charge generation layer by coating and drying, and coated thereon with a coating liquid containing the above-mentioned radical polymerizable composition of the present invention and acrylic-modified polyorganosiloxane. It is crosslinked and cured by 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.

As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it can be used alone or in combination with a binder resin.
As the solvent used for coating the lower layer portion of the charge transport layer, the same solvent as that for the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. In addition, the same coating method as that for the charge generation layer can be used to form the lower layer portion of the charge transport layer.

If necessary, a plasticizer and a leveling agent can be added.
As 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 appropriately about 5 to 40 μm, preferably about 10 to 30 μm.

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

<Single photosensitive layer>
The photosensitive layer having a single layer structure is a layer having a charge generation function and a charge transport function at the same time, and the crosslinked surface layer having the charge transport structure of the present invention contains a charge generation material having a charge generation function, thereby providing a single layer structure. It is useful as a photosensitive layer. As described in the method for forming a charge generation layer, the charge generation material is dispersed together with a coating 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 means for dispersing the charge generation material, the same charge generation material, charge transport material, plasticizer and leveling agent as those already described in the charge generation layer and charge transport layer can be used. As the binder resin, in addition to the binder resin previously mentioned in the section of the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. In addition, the above-described polymer charge transport materials can also be used, which is useful in that contamination of the lower photosensitive layer composition into the crosslinked surface layer can be reduced. The thickness of the lower layer portion of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.

  When the cross-linked surface layer is the surface portion of the photosensitive layer having a single layer structure, the coating solution containing the radical polymerizable composition of the present invention and the charge generating material is applied onto the lower layer portion of the photosensitive layer as described above. If necessary, after drying, it is cured by external energy such as heat or light to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness.

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

<About the intermediate layer>
In the photoreceptor of the present invention, when the crosslinked surface layer is 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, a photoreceptor having a smooth charge transporting cross-linked surface layer is used. For example, at least after the photoreceptor is charged, exposed to an image, and developed, an image holding member (transfer In the image forming method or apparatus in which the electrostatic latent image is directly transferred to the transfer body and developed, the process described above is arranged on the photoreceptor. Not necessarily.

FIG. 3 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as a means for charging the photoconductor on average. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known system can be used.
Next, the image exposure unit (5) is used to form an electrostatic latent image on the uniformly charged photoreceptor (1). As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Next, the developing unit (6) is used to visualize the electrostatic latent image formed on the photoreceptor (1). Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
Next, a transfer charger (10) is used to transfer the toner image visualized on the photoconductor onto the transfer body (9). In addition, a pre-transfer charger (7) may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.
Next, a separation charger (11) and a separation claw (12) are used as means for separating the transfer body (9) from the photoreceptor (1). As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger (11), the charging means can be used.
Next, a fur brush (14) and a cleaning blade (15) are used to clean the toner remaining on the photoreceptor after transfer. Further, a pre-cleaning charger (13) may be used in order to perform cleaning more efficiently. As other cleaning means, there are a web system, a magnet brush system, and the like, but a single system or a plurality of systems may be used together.
Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a charge removal charger are used, and the exposure light source and the charging means can be used respectively.
In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.

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

Referring to the image forming process by the apparatus illustrated in FIG. 4, the surface of the photoreceptor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. Be 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 photoreceptor having a polymer charge transport layer and a crosslinked surface layer is integrated with at least one of charging, developing, transferring, cleaning, and charge eliminating means.
As is apparent from the above description, the electrophotographic photosensitive member of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

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

（２）トリアリールアミノ基置換アクリレート化合物（表１中の例示化合物Ｎｏ．５４）
上記（１）で得られたヒドロキシ基置換トリアリールアミン化合物（構造式Ｂ）８２．９ｇ（０．２２７ｍｏｌ）をテトラヒドロフラン４００ｍｌに溶解し、窒素気流中で水酸化ナトリウム水溶液（ＮａＯＨ：１２．４ｇ，水：１００ｍｌ）を滴下した。この溶液を５℃に冷却し、アクリル酸クロライド２５．２ｇ（０．２７２ｍｏｌ）を４０分かけて滴下した。その後、５℃で３時間撹拌し反応を終了させた。この反応液を水に注ぎ、トルエンにて抽出した。この抽出液を炭酸水素ナトリウム水溶液と水で繰り返し洗浄した。その後、このトルエン溶液から溶媒を除去し、カラムクロマト処理（吸着媒体：シリカゲル、展開溶媒：トルエン）にて精製した。得られた無色のオイルにｎ−ヘキサンを加え、結晶を析出させた。この様にして例示化合物Ｎｏ．５４の白色結晶８０．７３ｇ（収率＝８４．８％）を得た。
融点：１１７．５〜１１９．０℃

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

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Note that “parts” used in the examples all represent parts by weight.
Example 1
An undercoat layer was formed on an Al support (outer diameter 30 mmφ) by dipping so that the film thickness after drying was 3.5 μm.
・ Coating liquid for undercoat layer 6 parts alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide (CR-EL: Ishihara Sangyo) 40 parts Methyl ethyl ketone 50 parts On this undercoat layer, it is dip-coated in a charge generation layer coating solution containing a bisazo pigment of the following structure, dried by heating, and a film thickness of 0.2 μm A charge generation layer was formed.
-Coating solution for charge generation layer 2.5 parts of bisazo pigment with the following structure

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ製） ０．５部
シクロヘキサノン ２００部
メチルエチルケトン ８０部
この電荷発生層上に下記構造の電荷輸送層用塗工液を用いて、浸積塗工し、加熱乾燥させ、膜厚２２μｍの電荷輸送層とした。
・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
下記構造の低分子電荷輸送物質 １０部

Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 parts Cyclohexanone 200 parts Methyl ethyl ketone 80 parts On this charge generation layer, dip-coating is performed using the coating liquid for charge transport layer having the following structure, followed by drying by heating. A charge transport layer of 22 μm was formed.
・ Coating solution for charge transport layer 10 parts of bisphenol Z type polycarbonate 10 parts of low molecular charge transport material with the following structure

テトラヒドロフラン ８０部
１％シリコーンオイルのテトラヒドロフラン溶液 ０．２部
（ＫＦ５０−１００ＣＳ、信越化学工業製）
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：７００ｍＷ／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３官能以上のラジカル重合性モノマー ９部
トリメチロールプロパントリアクリレート
（ＫＡＹＡＲＡＤ ＴＭＰＴＡ、日本化薬製）
分子量：３８２、官能基数：３官能、分子量／官能基数＝９９
電荷輸送性構造を有するラジカル重合性化合物 ９部
（例示化合物Ｎｏ．５４）
光重合開始剤 ２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）
精製したアクリル変性ポリオルガノシロキサン ２部
（シャリーヌＲ―１７０Ｓ、日信化学工業株式会社製）
テトラヒドロフラン １００部

Tetrahydrofuran 80 parts Tetrahydrofuran solution of 1% silicone oil 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
Spray coating is performed on the charge transport layer using a crosslinked surface layer coating solution having the following constitution, light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 700 mW / cm ² , irradiation time: 20 seconds, and further 130 ° C. Was dried for 30 minutes to provide a 4.0 μm cross-linked surface layer to obtain an electrophotographic photoreceptor of the present invention.
・ Crosslinked surface layer coating liquid Trifunctional or higher radical polymerizable monomer having no charge transporting structure 9 parts Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku)
Molecular weight: 382, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
9 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photoinitiator 2 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals)
Purified acrylic modified polyorganosiloxane 2 parts (Charine R-170S, manufactured by Nissin Chemical Industry Co., Ltd.)
Tetrahydrofuran 100 parts

Example 2
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that Charine R-170 (manufactured by Nissin Chemical Industry Co., Ltd.) was used as the acrylic-modified polyorganosiloxane of the crosslinked surface layer coating solution material of Example 1. did. The film thickness was 4.0 μm.

Example 3
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that Charine R-210 (manufactured by Nissin Chemical Industry Co., Ltd.) was used as the acrylic-modified polyorganosiloxane of the crosslinked surface layer coating solution material of Example 1. did. The film thickness was 4.5 μm

Example 4 (Reference Example)
As the radically polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution of Example 1, Exemplified Compound NO. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 182 was used. The film thickness was 4.0 μm.

Example 5 (Reference Example)
As the radically polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution of Example 1, Exemplified Compound NO. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 364 was used. The film thickness was 4.0 μm.

Example 6
As the radically polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution of Example 1, Exemplified Compound NO. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that No. 1 was used. The film thickness was 4.0 μm.

Example 7
As the radically polymerizable compound having a charge transporting structure in the crosslinked surface layer coating solution of Example 1, Exemplified Compound NO. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 53 was used. The film thickness was 4.0 μm.

Example 8
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the coating liquid for charge transport layer in Example 1 had the following constitution.
Polymer charge transport material having the following structure 20 parts (weight average molecular weight: 120,000)

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 ０．２部
（ＫＦ５０−１００ＣＳ、信越化学工業製）

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

Example 9
Electrophotography as in Example 1 except that the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating liquid of Example 1 was changed to the following monomer. A photoconductor was prepared. The film thickness was 4.0 μm.
Trifunctional or higher radical polymerizable monomer having no charge transporting structure Caprolactone-modified dipentaerythritol hexaacrylate (KAYARAD DPCA-60, manufactured by Nippon Kayaku Co., Ltd.)
Molecular weight: 1263, number of functional groups: 6 functions, molecular weight / number of functional groups = 211

Example 10
Examples 1-9 (Examples 4 and 5 are reference examples) The crosslinked surface layer sections of the photoreceptor were stained with ruthenic acid vapor, and the morphology was observed with a transmission electron microscope (H-9000NAR).
It can be seen that both exhibit a so-called microphase separation structure in which an acrylic-modified polyorganosiloxane dispersed phase having an average particle size of 0.2 to 0.4 μm is uniformly distributed in the matrix phase of the crosslinked surface layer.

Comparative Example 1
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the acrylic-modified polyorganosiloxane contained in the crosslinked surface layer coating solution in Example 1 was not added.

Comparative Example 2
The coating liquid for the crosslinked surface layer of Example 1 does not contain a tri- or higher functional radical polymerizable monomer having no charge transporting structure, and the amount of the radical polymerizable compound having a charge transporting structure is changed to 18 parts. Except for the above, an electrophotographic photosensitive member was produced in the same manner as in Example 1.

Comparative Example 3
The crosslinking surface layer coating solution of Example 1 does not contain a radical polymerizable compound having a charge transporting structure, and the amount of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure is changed to 18 parts. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that.

Comparative Example 4
Implemented except that the low molecular charge transport material used in the charge transport layer coating solution is used in place of the radical polymerizable compound having the charge transport structure in the crosslinked surface layer coating solution of Example 1. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

Comparative Example 5
A photoconductor for electrophotography was produced in the same manner as in Example 1 except that the acrylic-modified polyorganosiloxane in Example 1 was replaced with polysiloxane fine particles (Torefill R-902A manufactured by Toray Silicon Co., Ltd.).

Comparative Example 6
In Example 1, an electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the acrylic-modified polyorganosiloxane was replaced with tetrafluoroethylene resin particles (Lublon L-2, manufactured by Daikin Industries, Ltd.). Produced.

(Real machine paper test)
The prepared electrophotographic photosensitive member was tested for 150,000 sheets using a Ricoh imagio MF2200 remodeling machine (655 nm semiconductor laser as an image exposure light source) (A4, MyPaper made by NBS Ricoh, charged potential at start-700V). ) To evaluate wear characteristics, in-machine potential, and image evaluation. The results are shown in Tables 6-8.

Note) Examples 4 and 5 are reference examples.

Note) Examples 4 and 5 are reference examples.

注）実施例４及び５は参考例である。
スジ画像：○→良好、△→局部的に発生、×→画像全面に発生
画像濃度：○→良好、△→わずかに画像濃度定価、×→画像濃度低下

Note) Examples 4 and 5 are reference examples.
Streaked image: ○ → good, △ → locally generated, x → generated over the entire image Image density: ○ → good, △ → slight image density fixed price, x → image density decreased

Since Comparative Example 1 did not contain a copolymer containing polyorganosiloxane as a main component, a cleaning failure occurred, a streak image was generated on the entire surface in a 50,000-sheet passing test, and the image density was also lowered.
In Comparative Example 2, a number of cracks occurred immediately after the crosslinked surface layer was formed, and a streak-like image was generated on the entire surface.
In Comparative Examples 3 and 6, the exposed portion potential was higher than the initial value, and a decrease in image density was observed.
Since Comparative Example 4 contained a low molecular charge transport material having no reactivity in the crosslinked film, the amount of wear was large.
In Comparative Example 5, polysiloxane fine particles of a commonly used lubricant were added to the cross-linked film, but the compatibility between the fine particles and the cross-linked film resin was lacking, resulting in poor cleaning and 50,000-sheet passing test. As a result, a streak image occurred on the entire surface, and the image density also decreased.
On the other hand, in Examples 1 to 9 , especially Examples 1 to 3 and 6 to 9 of the present invention , the wear resistance is extremely high, no streak image and no crack are observed, and the image The decrease in concentration is also suppressed very effectively.
Therefore, a copolymer containing polyorganosiloxane as a main component is dispersed in the surface layer of the photosensitive layer of the present invention, and has at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a charge transport structure. It has been found that a long-life and high-performance photoconductor capable of maintaining a good image for a long period of time can be provided by using a cured cross-linked resin layer of a monofunctional radically polymerizable compound. In addition, it has been found that the image forming process, the image forming apparatus, and the process cartridge for the image forming apparatus using the photoconductor of the present invention have high performance and high reliability.

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 (21)

In an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support, a copolymer containing polyorganosiloxane as a constituent component is dispersed in the surface layer of the photosensitive layer, and the surface layer has at least a charge transporting structure. 3 electrophotographic photoreceptor or more functional groups of the radical polymerizable monomer and wherein the crosslinked resin layer der Rukoto formed by curing a monofunctional radically polymerizable compound having a charge transport structure no. 2. The electrophotography according to claim 1, wherein a functional group of a trifunctional or higher-functional radical polymerizable monomer having no charge transport structure used in the surface layer is an acryloyloxy group and / or a methacryloyloxy group. Photoconductor. Ratio of molecular weight to functionality in the trifunctional or more radical polymerizable monomer having no charge transport structure for use in the surface layer (molecular weight / number of functional groups) of claim 1 or 2, characterized in that 250 or less The electrophotographic photoreceptor described in 1. Electrons according to the functional groups of the radical polymerizable compound of monofunctional having a charge transport structure for use in the surface layer, any one of claims 1 to 3, characterized in that an acryloyloxy group or a methacryloyloxy group Photoconductor. The charge transport structure before Symbol monofunctional radically polymerizable compound having a charge transport structure for use in table surface layer, electrons according to any one of claims 1 to 4, characterized in that a triarylamine structure Photoconductor. Radical polymerizable compound monofunctional with that electrostatic charge transport structure employed in the surface layer, any of claims 1 to 5, characterized in that the following general formula (1) or (2) one or more An electrophotographic photoreceptor according to any one of the above.

[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, Ar ₄ represents a substituted or unsubstituted aryl group, or 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. ] Radical polymerizable compound monofunctional with that electrostatic charge transport structure employed in the surface layer, as claimed in any one of claims 1 to 6, characterized in that at least one of the following general formula (3) Electrophotographic photoreceptor.

(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. ) Contained in the surface layer, the copolymer containing polyorganosiloxane as a copolymer component, an electrophotographic photosensitive according to any one of claims 1 to 7, characterized in that an acrylic-modified polyorganosiloxane body. 9. The electrophotographic photoreceptor according to claim 8 , wherein the acrylic-modified polyorganosiloxane compound contained in the surface layer is a compound obtained by grafting an acrylic polymer to a silicone main chain. The acrylic-modified polyorganosiloxane contained in the surface layer has the following general formula (5)

[In the formula, R ₂₀ , R ₂₁ and R ₂₂ are the same or different, respectively, a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, Y is a radical reactive group, an SH group or an organic group having both. , Z ₁ and Z ₂ are the same or different hydrogen atoms, lower alkyl groups or

Groups (R ₂₃ and R ₂₄ are the same or different, respectively, a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, R ₂₅ is a hydrocarbon group or halogenated hydrocarbon group having 1 to 20 carbon atoms, or a radical Represents an organic group having a reactive group and / or an SH group), u is a positive integer of 10,000 or less, and v is an integer of 1 or more], and the following general formula ( 6)

(In the formula, R ₂₆ represents a hydrogen atom or a methyl group, and R ₂₇ represents an alkyl group, an alkoxy-substituted alkyl group, a cycloalkyl group, or an aryl group.)
Or a mixture of 10% by weight or more of this (meth) acrylic acid ester and 90% by weight or less of a copolymerizable monomer with a weight ratio of 5:95 to 95: 5 The electrophotographic photosensitive member according to claim 8 or 9 , which is an acrylic-modified polyorganosiloxane obtained by emulsion graft copolymerization at a ratio. The acrylic-modified polyorganosiloxane contained in the surface layer is a polyorganosiloxane represented by the general formula (5) and a (meth) acrylic acid ester represented by the general formula (6), or this (meth) acrylic. It is an acrylic modified polyorganosiloxane obtained by emulsion graft copolymerization of a mixture of 70% by weight or more of an acid ester and 30% by weight or less of a copolymerizable monomer at a weight ratio of 51:49 to 95: 5. The electrophotographic photosensitive member according to claim 10 . The acrylic-modified polyorganosiloxane contained in the surface layer is a polyorganosiloxane represented by the general formula (5) and a (meth) acrylic acid ester represented by the general formula (6), or this (meth) acrylic. An acrylic-modified polyorganosiloxane obtained by emulsion graft copolymerization of a mixture of 70% by weight or more of an acid ester and 30% by weight or less of a copolymerizable monomer at a weight ratio of 65:35 to 95: 5. The electrophotographic photosensitive member according to claim 10 . (Meth) acrylic acid ester used as a component of the general formula (6) or the (meth) Glass transition temperature of the polymer product of the mixture of the other copolymerizable monomer and acrylic acid esters is 20 ° C. or more, the electrophotographic photosensitive member according to any one of claims 10 to 12, characterized in that there. The electrophotographic photosensitive member according to any one of claims 8 to 13 wherein the acrylic modified polyorganosiloxane compound is characterized by being dispersed in granular form. The charge generating layer photosensitive layer from the support side, a charge transport layer, the electrophotographic photosensitive member according to any one of claims 1 to 14, characterized in that a laminated structure of the surface layer. The electrophotographic photosensitive member according to claim 15 , wherein the charge transport layer of the photosensitive layer contains a polymer charge transport material. 17. The electrophotographic photoreceptor according to claim 16 , wherein the polymer charge transport material is a polycarbonate having a triarylamine structure in the main chain or side chain. The electrophotographic photosensitive member according to any one of claims 1 to 17, wherein the curing means of the surface layer is a heat or light energy irradiating means. Using an electrophotographic photosensitive member according to any one of claims 1 to 18, 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 18. An electrophotographic photosensitive member according to any one of claims 1 to 18 , and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, a cleaning means, and a charge eliminating means, A process cartridge for an image forming apparatus, wherein the process cartridge is removable from a main body of the forming apparatus.

Images