JP2012098639A - Electrophotographic photoreceptor, image forming apparatus using the same, and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-life electrophotographic photoreceptor that has high abrasion resistance and excellent electrical characteristics; suppresses deterioration in image quality such as image blur, residual images, and poor cleaning; and stably outputs high quality images for a long period.SOLUTION: An electrophotographic photoreceptor is formed by laminating a photosensitive layer and a surface layer on a conductive support. The surface layer contains crosslinked resin obtained by curing a radical polymerizable monomer without a charge transport structure and a radical polymerizable compound with a charge transport structure, and a filler; and the photosensitive layer and/or the surface layer contain a charge transport material represented by the general formula (1).

Description

  The present invention has high wear resistance, good electrical characteristics even after repeated use, can suppress deterioration in image quality such as afterimages and image blurring, and can stably output high-quality images over a long period of time. The present invention relates to an electrophotographic photosensitive member, an image forming apparatus, and a process cartridge for the image forming apparatus.

In recent years, organic photoreceptors (OPCs) have been widely used in copying machines, facsimiles, laser printers, and complex machines of these in place of inorganic photoreceptors.
The reasons include, for example, (1) productivity, (2) freedom of material design, (3) low cost, and (4) low environmental load. On the other hand, as the image forming apparatus is downsized, the diameter of the photoconductor has been reduced, and further, the speed of the apparatus has been increased and maintenance has been made free. Therefore, the high durability of the organic photoconductor has been strongly demanded. I came.
Organic photoreceptors generally have a drawback that they are soft because they are mainly composed of a low molecular charge transport material and an inert polymer, and are easily worn when used repeatedly in an electrophotographic process. The wear of the organic photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability deterioration, and as a result, causes abnormal images such as image density reduction and background stains. In addition, if scratches are formed on the surface of the organic photoreceptor, it may cause image defects due to poor cleaning or foreign matter adhesion.
Therefore, increasing the wear resistance is one of the important issues for increasing the durability of the organic photoreceptor.

  Techniques for improving the wear resistance of the organic photoreceptor include (1) a technique in which a curable binder is used for the surface layer (for example, see JP-A-56-48637 of Patent Document 1), and (2) a polymer type. One using a charge transport material (for example, see JP-A No. 64-1728 of Patent Document 2), (3) One in which an inorganic filler is dispersed in the surface layer (for example, JP-A-4-281461 of Patent Document 3) For example). Among these techniques, those using the curable binder (1) are effective techniques for improving wear resistance, but are compatible with charge transport materials, impurities such as polymerization initiators, and the like. There has been a problem that the stability of electric characteristics deteriorates due to the influence of the reaction residue and the like, such as an increase in residual potential and a decrease in chargeability. In addition, although the wear resistance is improved in the case of using the polymer type charge transport material (2) as compared with the case of using a low molecular weight charge transport material, it does not reach a level satisfying the requirement. In addition, productivity is inferior. The dispersion of the inorganic filler (3) is effective for improving the abrasion resistance, but the residual potential increases due to traps present on the surface of the inorganic filler, and there is a tendency that the image density is not stable. .

  Further, even though the wear resistance can be improved by the addition of the filler, the scratch resistance is not sufficient, and there is a problem that the scratches formed on the surface induce a defective cleaning or adhesion of foreign substances, thereby causing deterioration of image quality. Therefore, in these conventional techniques, even if the abrasion resistance of the organic photoconductor is improved, it is not sufficient, or the durability to the electric characteristics and the image quality is poor. As a result, the high durability of the organic photoconductor is not achieved. The level is not satisfactory.

  On the other hand, in the prior art using a curable binder, there is also disclosed a photoreceptor containing a polyfunctional acrylate monomer cured product in order to improve wear resistance and scratch resistance (Japanese Patent No. 3262488 of Patent Document 4). No. publication). However, there is no specific description of the fact that the surface transport layer may be included in the surface layer provided on the photosensitive layer, but there is no specific description, and if the surface layer simply contains a low molecular charge transport material, Since the compatibility with the cured product is poor, the charge transport material is deposited, and as a result, there is a problem that high durability cannot be achieved due to an increase in residual potential or a decrease in mechanical strength. Furthermore, since this photoconductor specifically reacts with the monomer in a state containing a polymer binder, there is a problem that the curing does not proceed sufficiently, and there is a problem of compatibility between the cured product and the binder resin. There was also a problem that surface unevenness due to separation occurred, resulting in poor cleaning.

  On the other hand, a technique for providing a charge transport layer formed using a coating liquid composed of a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin is disclosed. (For example, refer to Japanese Patent No. 3194392 of Patent Document 5). This binder resin includes those having a carbon-carbon double bond and having reactivity with respect to the charge transport material and those having no double bond and not having reactivity. Therefore, it has the effect of achieving both high wear resistance and good electrical properties, but when a non-reactive binder resin is used, the reaction between the binder resin, the monomer and the charge transport agent The compatibility with the generated cured product was poor, and phase separation caused surface irregularities during crosslinking, resulting in a problem of poor cleaning. In addition, 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 monomer, and the number of functional groups in the bifunctional monomer is Due to the small amount, a sufficient crosslinking density could not be obtained, and from these, the abrasion resistance was not satisfactory.

  In addition, 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 disclosed (for example, Japanese Patent Application Laid-Open No. 2000-66425 of Patent Document 6). reference). However, this photosensitive layer has a bulky hole transporting compound having two or more chain-polymerizable functional groups, so that distortion occurs in the cured product, resulting in high internal stress. Cracks may occur.

Furthermore, there is also disclosed a cross-linked charge transport layer obtained by curing a tri- or higher functional radical polymerizable monomer having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure (Patent Document 7). No. 2004-302450, JP-A No. 2004-302451 of JP-A-2004-302451, JP-A No. 2004-302452 of JP-A-2004-302452). By using a monofunctional radically polymerizable compound having a charge transporting structure, both mechanical and electrical durability are achieved, and the occurrence of cracks is also suppressed. However, the electrical characteristics changed depending on long-term repeated use and the use environment, and there was a problem in stability such as image density.
As described above, in order to achieve high durability in the organic photoconductor, it is necessary to improve the wear resistance. Adhering causes image blurring, poor cleaning, toner material filming, etc., and higher durability of the photoreceptor is satisfied by the side effects of these electrical characteristics and image quality deterioration than the effect of improving wear resistance. The situation was not reached.

  Improvements in electrical properties, especially environmental stability, have been attempted through the development of charge transport materials. For example, Japanese Patent Application Laid-Open No. 3-75660 of Patent Document 10 discloses an electrophotographic photosensitive member using an indoline-based charge transport material having a specific structure for the charge transport layer. Similarly, JP-A-5-6011 of Patent Document 11 and JP-A-11-149170 of Patent Document 12 disclose a charge transfer agent. On the other hand, Japanese Patent Application Laid-Open No. 2004-279939 of Patent Document 13 discloses an oxytitanium phthalocyanine having a specific crystal structure in which the Bragg angle (2θ ± 0.2 °) 27.2 ° of the X-ray diffraction spectrum has a maximum peak in the comparative example. And indoline-based charge transport materials having specific structures are disclosed.

  However, even if the electrical characteristics are improved by the charge transport material used in the photosensitive layer, if the surface layer has a large number of charge trap sites, the fundamental solution cannot be achieved. In addition, the charge transport material contained in the photosensitive layer is dissolved into the surface layer side when the surface layer is provided on the photosensitive layer, which causes a problem of inhibiting crosslinking. In addition, in the case of crosslinking by ultraviolet irradiation, there is a problem that the charge transport material dissolved in the surface layer is deteriorated and electrical characteristics are deteriorated. Further, the inhibition of crosslinking may deteriorate the film quality, resulting in poor cleaning and filming. Therefore, a photoreceptor using a crosslinkable resin for the surface layer can achieve both wear resistance and electrical characteristics unless the charge transport material used in the photosensitive layer is optimized as well as the surface layer. Furthermore, unless the image quality deterioration due to image blurring, afterimages, poor cleaning, filming, or the like is suppressed, high durability of the photoreceptor cannot be realized.

  An object of the present invention is to provide a long-life electrophotographic photosensitive member that has high wear resistance, good electrical characteristics, suppresses image quality degradation such as image blurring, afterimages, and poor cleaning, and can stably output high-quality images over a long period of time. And an image forming apparatus and a process cartridge for the image forming apparatus.

In the present invention, as a result of intensive studies on the above problems, the crosslinkability obtained by curing a radically polymerizable monomer whose surface layer does not have a charge transporting structure and a radically polymerizable compound having a charge transporting structure. It has been found that the above-mentioned problems can be solved by an electrophotographic photoreceptor containing a resin and a filler and using a specific charge transport material in the photosensitive layer, and the present invention has been completed.
That is, the said subject is solved by this invention of the following (1)-(16).
(1) “In an electrophotographic photosensitive member formed by laminating at least a photosensitive layer and a surface layer on a conductive support, the surface layer includes a radical polymerizable monomer having no charge transporting structure, and a charge transporting property. A charge transport material comprising a crosslinkable resin and a filler obtained by curing a radically polymerizable compound having a structure, and wherein the photosensitive layer and / or the surface layer is represented by the general formulas (1), (2) and (3) An electrophotographic photoreceptor comprising at least one of the above.

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）」、
（２）「前記感光層及び表面層のいずれか、もしくは両方に、酸化防止剤を含有することを特徴とする前記第（１）項に記載の電子写真感光体」、
（３）「前記感光層及び表面層のいずれか、もしくは両方に、下記一般式（４）で表わされるジアミン化合物を含有することを特徴とする前記第（１）項又は第（２）項に記載の電子写真感光体

(Wherein R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms).
(2) "The electrophotographic photosensitive member according to (1) above, wherein an antioxidant is contained in one or both of the photosensitive layer and the surface layer",
(3) In the item (1) or the item (2), the diamine compound represented by the following general formula (4) is contained in either or both of the photosensitive layer and the surface layer. The electrophotographic photoreceptor described

（式中、Ａ_１、Ａ_２は、下記（ｉ）、（ii）、及び（iii）より選択される基を表わし、各々同一でも異なっていてもよい。但し、（ｉ）、（ii）の場合はＡ_１及びＡ_２が各々同一であっても異なっていてもよいが、（iii）の場合はＡ_１及びＡ_２のいずれかにのみ形成される。
（ｉ）炭素数１〜４のアルキル基
（ii）−ＣＨ_２（ＣＨ_２）_ｍＺ
（iii）置換基を有してもよいアリール基
但し、Ｚは、アリール基、シクロアルキル基、ヘテロシクロアルキル基を表わし、さらに置換基を有してもよい。また、ｍは０及び１のいずれかの整数を表わす。
式中、Ａｒは置換基を有していてもよいアリーレン基を表わす。）」、
（４）「前記電荷輸送性構造を有さないラジカル重合性モノマーが、官能基数が３以上のラジカル重合性モノマーを含むことを特徴とする前記第（１）項乃至第（３）項のいずれかに記載の電子写真感光体」、
（５）「前記電荷輸送性構造を有するラジカル重合性化合物が、官能基数が１のラジカル重合性化合物を含むことを特徴とする前記第（１）項乃至第（４）項のいずれかに記載の電子写真感光体」、
（６）「前記電荷輸送性構造を有さないラジカル重合性モノマー及び／または電荷輸送性構造を有するラジカル重合性化合物が、アクリロイルオキシ基及びメタクリルイルオキシ基よりなる群から選ばれた官能基を有することを特徴とする前記第（１）項乃至第（５）項のいずれかに記載の電子写真感光体」、
（７）「前記電荷輸送性構造を有するラジカル重合性化合物の電荷輸送性構造が、トリアリールアミン構造であることを特徴とする前記第（１）項乃至第（６）項のいずれか記載の電子写真感光体」、
（８）「前記電荷輸送性構造を有するラジカル重合性化合物が、下記一般式（５）又は（６）の一種以上であることを特徴とする前記第（７）項に記載の電子写真感光体。

(In the formula, A ₁ and A ₂ represent groups selected from the following (i), (ii), and (iii), and may be the same or different, provided that (i), (ii) for although may be the same or different, each a ₁ and a _2, in the case of (iii) is formed only on one of a ₁ and a _2.
(I) an alkyl group having 1 to 4 carbon atoms _{(ii) -CH 2 (CH 2} ) m Z
(Iii) Aryl Group that may have a Substituent However, Z represents an aryl group, a cycloalkyl group, or a heterocycloalkyl group, and may further have a substituent. M represents an integer of 0 and 1.
In the formula, Ar represents an arylene group which may have a substituent. ) ",
(4) "Any of the above items (1) to (3), wherein the radical polymerizable monomer having no charge transport structure includes a radical polymerizable monomer having a functional group number of 3 or more. The electrophotographic photosensitive member described in "
(5) “The radically polymerizable compound having a charge transporting structure includes a radically polymerizable compound having one functional group,” (1) to (4), Electrophotographic photoreceptor ",
(6) "A functional group selected from the group consisting of an acryloyloxy group and a methacrylyloxy group, wherein the radical polymerizable monomer having no charge transport structure and / or the radical polymerizable compound having a charge transport structure is The electrophotographic photosensitive member according to any one of (1) to (5) above,
(7) The charge transporting structure of the radical polymerizable compound having the charge transporting structure is a triarylamine structure, according to any one of (1) to (6) above Electrophotographic photoreceptor ",
(8) The electrophotographic photosensitive member according to item (7), wherein the radical polymerizable compound having the charge transporting structure is one or more of the following general formula (5) or (6): .

（上式（５）及び（６）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_２（Ｒ_２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_３Ｒ_４（Ｒ_３及びＲ_４は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル２価基、アルキレンオキシカルボニル２価基を表わす。ｍ、ｎは０〜３の整数を表わす。）」、
（９）「表面層がフィラーを含有し、前記フィラーが金属酸化物であることを特徴とする前記第（１）項乃至第（８）項のいずれかに記載の電子写真感光体」、
（１０）「前記金属酸化物がα−アルミナであることを特徴とする前記第（９）項に記載の電子写真感光体」、
（１１）「前記フィラーの平均一次粒子径が、０．１μｍ以上１．０μｍ以下であることを特徴とする前記第（９）項又は第（１０）項のいずれかに記載の電子写真感光体」、
（１２）「前記電子写真感光体と、少なくとも帯電手段、露光手段、現像手段、転写手段を有する画像形成装置において、該電子写真感光体が前記第（１）項乃至第（１１）項のいずれかに記載の電子写真感光体であることを特徴とする画像形成装置」、
（１３）「前記画像形成装置において、前記電子写真感光体の表面に潤滑性物質を付着させる潤滑性物質供給手段を有することを特徴とする前記第（１２）項に記載の画像形成装置」、
（１４）「前記潤滑性物質が、ステアリン酸亜鉛を含むことを特徴とする前記第（１３）項に記載の画像形成装置」、
（１５）「前記画像形成装置において、前記電子写真感光体と、少なくとも帯電手段、現像手段、潤滑性物質塗布手段より選択される一つ以上の手段からなる画像形成要素を複数配列したタンデム方式であることを特徴とする前記第（１２）項乃至第（１４）項のいずれかに記載の画像形成装置」、
（１６）「前記電子写真感光体と、少なくとも帯電手段、現像手段、潤滑性物質塗布手段より選択される一つ以上の手段とを有し、前記第（１２）項乃至第（１５）項のいずれかに記載の画像形成装置本体に着脱可能であることを特徴とするプロセスカートリッジ。」。

(In the above formulas (5) and (6), R ₁ 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. Good aryl group, cyano group, nitro group, alkoxy group, —COOR ₂ (R ₂ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Aryl group), a carbonyl halide group, or CONR ₃ R ₄ (R ₃ and R ₄ are a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, or an aralkyl group that may have a substituent. Or an aryl group which may have a substituent, which may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same It may be different _.Ar 3, r ₄ represents a substituted or unsubstituted aryl group, which may be identical or different .X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted Represents an 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 divalent group, or an alkyleneoxycarbonyl divalent group, and m and n are 0. Represents an integer of ~ 3) ",
(9) "The electrophotographic photosensitive member according to any one of (1) to (8) above, wherein the surface layer contains a filler, and the filler is a metal oxide",
(10) “The electrophotographic photosensitive member according to (9) above, wherein the metal oxide is α-alumina”,
(11) The electrophotographic photosensitive member according to any one of (9) or (10), wherein the average primary particle diameter of the filler is 0.1 μm or more and 1.0 μm or less. "
(12) In the image forming apparatus having the electrophotographic photosensitive member and at least a charging unit, an exposing unit, a developing unit, and a transferring unit, the electrophotographic photosensitive member is any one of items (1) to (11). An image forming apparatus characterized by being an electrophotographic photosensitive member according to claim 1,
(13) “The image forming apparatus according to (12), wherein the image forming apparatus includes a lubricating substance supply unit that adheres a lubricating substance to a surface of the electrophotographic photosensitive member”;
(14) “Image forming apparatus according to item (13), wherein the lubricating substance contains zinc stearate”;
(15) “In the image forming apparatus, a tandem system in which a plurality of image forming elements each including at least one selected from the electrophotographic photosensitive member and at least a charging unit, a developing unit, and a lubricating substance applying unit are arranged. The image forming apparatus according to any one of (12) to (14),
(16) “The electrophotographic photosensitive member and at least one unit selected from a charging unit, a developing unit, and a lubricating substance coating unit”, and the items (12) to (15) A process cartridge which is detachable from the image forming apparatus main body according to any one of the above.

  According to the present invention, the surface layer contains a radically polymerizable monomer having no charge transporting structure and a crosslinkable resin and filler obtained by curing a radically polymerizable compound having a charge transporting structure. By including a specific charge transporting material, not only the wear resistance can be remarkably improved, but also the scratch resistance becomes very high, and even when used repeatedly for a long time, almost no wear and scratches are observed. Therefore, filming and foreign matter adhesion are suppressed, and image blurring, cleaning failure, and image defects due to foreign matter can be prevented. Further, by incorporating the charge transport material of the present invention in the photosensitive layer, the charge injection property from the photosensitive layer to the surface layer is improved, and the electrical characteristics are improved even in long-term repeated use or in various usage environments. Deterioration can be reduced. For this reason, afterimages can be output in various environments after repeated use for a long time, and afterimages and image density fluctuations can be prevented. As a result, high-quality images can be output stably over a long period of time in any environment. You can continue. Accordingly, it is possible to provide an electrophotographic photosensitive member, an image forming apparatus, and a process cartridge for the image forming apparatus that are excellent in image quality consistency.

It is a figure which shows the layer structure of the electrophotographic photoreceptor 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. FIG. 4 is an X-ray diffraction spectrum diagram of the charge generation material used in the examples, in which the vertical axis represents the counts per second (cps) and the horizontal axis represents the angle (2θ).

Hereinafter, the present invention will be described in detail.
The present invention relates to an electrophotographic photosensitive member obtained by laminating at least a photosensitive layer and a surface layer in this order on a conductive support, a radical polymerizable monomer in which the surface layer does not have a charge transporting structure, and a charge transporting property. A charge transport material comprising a crosslinkable resin and a filler obtained by curing a radically polymerizable compound having a structure, and wherein the photosensitive layer and / or the surface layer is represented by the general formulas (1), (2) and (3) An electrophotographic photoreceptor comprising at least one of the above.

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

（式中、Ｒ_１〜Ｒ_４は、各々独立に水素、ハロゲン原子、置換基を有してもよい炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基を表わす。）

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

<Layer structure of electrophotographic photoreceptor>
The layer structure of the electrophotographic photoreceptor of the present invention will be described with reference to FIG.
FIG. 1 is a sectional view showing the layer structure of an electrophotographic photosensitive member.
In FIG. 1-A, a surface layer (33) is laminated on a photosensitive layer having a single layer structure in which a photosensitive layer (32) having both a charge generation function and a charge transport function is provided on a conductive support (31). It is a photoreceptor.
FIG. 1-B shows a photosensitive structure having a laminated structure in which a charge generation layer (34) having a charge generation function and a charge transport layer (35) having a charge transport material function are laminated on a conductive support (31). This is a photoreceptor in which the surface layer (33) is laminated on the layer.
Further, as shown in FIGS. 1-C and 1-D, the conductive support (31) and the photosensitive layer (32) or the conductive support (31) and the charge generation layer (34) are subtracted. It is also possible to provide a layer (36).

<Conductive support>
As the conductive support (31), a material having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium is deposited or sputtered to form film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. After conversion, a tube that has been subjected to surface treatment such as cutting, superfinishing, or polishing can be used.
Further, an endless nickel belt and an endless stainless steel belt disclosed in Japanese Patent Publication No. 52-36016 can also be used as the conductive support (31).
In addition, the conductive support dispersed in a suitable binder resin and coated on the support can also be used as the conductive support (31) 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 (31) of the present invention.

<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. In the present invention, the photosensitive layer preferably has a laminated structure from the viewpoint of stability of electrical characteristics. Hereinafter, the laminated photosensitive layer will be described.

<Charge generation layer>
The charge generation layer (34) 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.

  As the organic material, the following known materials can be used. For example, monoazo pigment, disazo pigment, asymmetric disazo pigment, trisazo pigment, azo pigment having carbazole skeleton, azo pigment having distyrylbenzene skeleton, azo pigment having triphenylamine skeleton, azo pigment having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, etc. Azo pigments, azulenium salt pigments, squalic acid methine pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphtho Quinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, also metal phthalocyanine backbone represented by the following general formula (7), phthalocyanine pigments such as metal-free phthalocyanine. These charge generation materials can be used alone or as a mixture of two or more.

In the above general formula (7), M (center metal) represents a metal and a metal-free (hydrogen) element.
M (central metal) mentioned here is H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga , Ge, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, TI , La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., or oxide, chloride It consists of two or more elements such as fluoride, fluoride, hydroxide and bromide. The central metal is not limited to these elements.

  The charge generation material having a phthalocyanine skeleton in the present invention may have at least the basic skeleton of the general chemical formula (7), and those having a multimeric structure such as a dimer, a trimer, etc. It may have a polymer structure of In addition, the basic skeleton may have various substituents. Of these various phthalocyanines, titanyl phthalocyanine having TiO as a central metal, metal-free phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, and the like are particularly preferable in terms of photoreceptor characteristics. These phthalocyanines are known to have various crystal systems. For example, in the case of titanyl phthalocyanine, α, β, γ, m, Y type, etc., in the case of copper phthalocyanine, α, β, γ, etc. It has a polycrystal system. Even in the phthalocyanine having the same central metal, various characteristics change as the crystal system changes. It has been reported that the characteristics of photoreceptors using phthalocyanine pigments having these various crystal systems also change accordingly (Journal of Electrophotographic Society, Vol. 29, No. 4, 1990). Therefore, the selection of the phthalocyanine crystal system is very important in terms of the photoreceptor characteristics. Among these phthalocyanine pigments, a titanyl phthalocyanine crystal having a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray (1.542 °) of CuKα is particularly Since it has high sensitivity, it is used particularly effectively.

  The binder resin used as necessary for the charge generation layer (34) includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-. Examples thereof include vinyl carbazole and 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 transfer agent having a charge transport function, such as an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, a stilbene skeleton, a 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.

The charge generation layer (34) can also contain a low molecular charge transport material.
Low molecular charge transport materials that can be used in combination with the charge generation layer (34) 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. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9- Examples include styryl anthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bis-stilbene derivatives, enamine derivatives, distyryl derivatives, and the like. These hole transport materials can be used alone or as a mixture of two or more.

  As a method for forming the charge generation layer (34), a vacuum thin film preparation method and a casting method from a solution dispersion system can be largely mentioned. For the vacuum thin film production 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 order to provide a charge generation layer by a casting method from a solution dispersion, the above inorganic or organic charge generation materials are used together with a binder resin, if necessary, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, Formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as cyclopentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. it can. 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.

<Charge transport layer>
The charge transport layer (35) is a layer having a charge transport function, and is mainly composed of a charge transport material and a binder resin. As the charge transport material, compounds represented by the above general formulas (1), (2) and (3) are used. Specifically, these charge transport materials are more preferably compounds represented by the following general formulas (8) to (22) in the present invention. However, these are merely examples, and the present invention is not limited thereto.

In addition, it is possible and effective to mix a charge transport material other than the charge transport materials represented by the general formulas (1) to (3) in the charge transport layer of the present invention.
Examples of other charge transport materials include electron transport materials such as chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7- Tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophene-4- Examples thereof include substances such as ON, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives, and naphthalenetetracarboxylic acid diimide.
These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transport material include poly (N-vinylcarbazole) and derivatives thereof, poly (γ-carbazolylethyl glutamate) and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, and oxazole. Derivatives, oxadiazole derivatives, imidazole derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, aminobiphenyl derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinyl Benzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., distyrylbenzene derivatives, enamine derivatives, or polymer charge transport materials Etc. Others, polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl pyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, polyisothianaphthene, polyaniline, It is also possible to use conductive polymer compounds such as polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, and polyphthalocyanine.

  Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins. The content of the charge transport material is appropriately 20 to 300 parts by weight, preferably 30 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.

  In the present invention, it is possible and effective to add various additives such as an antioxidant, a plasticizer, a leveling agent, and an ultraviolet absorber. Addition of an antioxidant is effective in suppressing dark portion potential reduction, improving gas resistance, and suppressing image blur. As an example of the antioxidant, conventionally known materials such as phenol compounds, paraphenylenediamines, hydroquinones, organic sulfur compounds, organic phosphorus compounds, hindered amines and the like can be used. The addition amount of the antioxidant is preferably 0 to 10% by weight, and more preferably 0.1 to 5% by weight with respect to the charge transport material. An example of an antioxidant that can be used in the present invention is shown below.

(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] Glycol esters, tocopherols, etc.

(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.

  The plasticizer has an effect of improving the gas resistance of the charge transport layer and preventing the occurrence of cracks. As an example of the plasticizer, plasticizers such as dibutyl phthalate and dioctyl phthalate can be used and are effective. The addition amount of the plasticizer is preferably 0 to 30% by weight and more preferably 1 to 10% by weight with respect to the binder resin. By adding a leveling agent, the film quality of the charge transport layer is improved and the occurrence of coating film defects can be prevented. Further, the film thickness unevenness is reduced, and a smooth film can be obtained. As an example of the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers having a perfluoroalkyl group in the side chain, oligomers, and the like are used. The amount used is preferably 0 to 1% by weight, more preferably 0.01% to 0.5% by weight, based on the binder resin.

  Furthermore, in the present invention, the addition of the diamine compound represented by the following general formula (4) can obtain a remarkable suppression effect on the deterioration of electric characteristics and gas resistance due to repeated use and the resulting image blur. it can. In particular, the combination with the charge transport material of the present invention has little effect on the residual potential, is effective in stabilizing electrical characteristics over time of repeated use, and is also effective in suppressing image blur due to exposure to oxidizing gas. It is very effective. These addition amounts are preferably 0 to 30% by weight, more preferably 3 to 15% by weight, based on the charge transport material.

（式中、Ａ_１、Ａ_２は、下記（ｉ）、（ii）、及び（iii）より選択される基を表わし、各々同一でも異なっていてもよい。但し、（ｉ）、（ii）の場合はＡ_１及びＡ_２が各々同一であっても異なっていてもよいが、（iii）の場合はＡ_１及びＡ_２のいずれかにのみ形成される。
（ｉ）炭素数１〜４のアルキル基
（ii）−ＣＨ_２（ＣＨ_２）ｍＺ
（iii）置換基を有してもよいアリール基
但し、Ｚは、アリール基、シクロアルキル基、ヘテロシクロアルキル基を表わし、さらに置換基を有してもよい。また、ｍは０及び１のいずれかの整数を表わす。
式中、Ａｒは置換基を有していてもよいアリーレン基を表わす。）

(In the formula, A ₁ and A ₂ represent groups selected from the following (i), (ii), and (iii), and may be the same or different, provided that (i), (ii) for although may be the same or different, each a ₁ and a _2, in the case of (iii) is formed only on one of a ₁ and a _2.
(I) an alkyl group having 1 to 4 carbon atoms (ii) —CH ₂ (CH ₂ ) mZ
(Iii) Aryl Group that may have a Substituent However, Z represents an aryl group, a cycloalkyl group, or a heterocycloalkyl group, and may further have a substituent. M represents an integer of 0 and 1.
In the formula, Ar represents an arylene group which may have a substituent. )

  Specific examples of these compounds are described below. However, these compounds are examples, and the present invention is not limited to these compounds.

Solvents used for coating the charge transport layer include solvents such as tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclopentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, and butyl acetate. Although those that can be used, those that dissolve the charge transport material and the binder resin well are suitable. These solvents may be used alone or in combination of two or more.
As a method for coating the charge transport layer, known methods such as dip coating, spray coating, bead coating, nozzle coating, spinner coating, and ring coating can be used, and among these, dip coating is more preferable. After coating, it is manufactured by drying with the touch and then heating and drying in an oven or the like. Although the drying temperature of a charge transport layer changes with kinds of solvent contained in the coating liquid of a charge transport layer, it is preferable that it is 80-150 degreeC, and 100-140 degreeC is more preferable. The thickness of the charge transport layer thus obtained is usually 10 to 50 μm, and more preferably 15 to 35 μm.

<Single layer photosensitive layer>
The photosensitive layer (32) having a single layer structure is a layer having a charge generation function and a charge transport function at the same time, and the photosensitive layer comprises a charge generation substance having a charge generation function, a charge transport substance having a charge transport function, and a binder resin. It can be formed by dissolving or dispersing in a suitable solvent, coating and drying.
As the charge generation material contained in the photosensitive layer, the materials described in the charge generation layer (34) can be applied. Moreover, the charge transport material is represented by the general formulas (1) to (3) described above, and the materials described in the charge transport layer (35) can be applied. Further, the materials described in the charge generation layer (34) and the charge transport layer (35) can be applied to the binder resin. The charge generating material contained in the single photosensitive layer is preferably 1 to 30% by weight based on the total amount of the photosensitive layer, the charge transporting material is preferably 10 to 70% by weight, and the binder resin contained in the photosensitive layer is 20%. ˜80% by weight is used favorably.
Furthermore, an antioxidant, a plasticizer, a leveling agent, etc. can also be added as needed.
The materials described in the charge transport layer (35) can also be applied to these additives. The film thickness of the photosensitive layer is suitably about 5 to 40 μm, preferably about 10 to 30 μm.

<Surface layer>
A surface layer is formed on the surface of the photoreceptor of the present invention. The surface layer of the present invention is characterized by containing a crosslinkable resin and a filler obtained by curing a radically polymerizable monomer having no charge transporting structure and a radically polymerizable compound having a charge transporting structure. A radically polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a charge transporting structure form a three-dimensional network structure, whereby a high hardness surface with a high degree of crosslinking can be obtained. This makes it possible to achieve both high wear resistance and high electrical characteristics.
In addition, the addition of the filler makes the surface layer more tough and dramatically improves the scratch resistance. Further, the effect of improving the scratch resistance and the formation of fine irregularities on the surface by the filler improves the cleaning property and reduces foreign matter adhesion and filming.

The radically polymerizable monomer having no charge transporting structure and the radically polymerizable compound having a charge transporting structure in the present invention will be described below.
As a radical polymerizable monomer having no charge transport structure, a structure responsible for charge transport, for example, a hole transport structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, A monomer that does not have an electron transport structure such as an electron-withdrawing aromatic ring having a cyano group or a nitro group and has a radical polymerizable functional group.
The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization. Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
As the 1-substituted ethylene functional group, for example, a functional group represented by the following general formula (23) is preferably exemplified.

ただし、前記一般式（２３）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_３０）−基（ただし、Ｒ_３０は、水素原子、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。）、又は−Ｓ−基を表わす。
これらの置換基としては、具体的には、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。

However, the general formula (23), X ₁ is an optionally substituted phenylene group, an arylene group, an alkenylene group which may have a substituent such as a naphthylene group, -CO- group, —COO— group, —CON (R ₃₀ ) — group (wherein R ₃₀ is a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group, a naphthylmethyl group or a phenethyl group, a phenyl group, Represents an aryl group such as a naphthyl group), or an -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.

  As the 1,1-substituted ethylene functional group, for example, a functional group represented by the following general formula (24) is preferably exemplified.

ただし、前記一般式（２４）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_３１基（ただし、Ｒ_３１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）、又は−ＣＯＮＲ_３２Ｒ_３３（ただし、Ｒ_３２及びＲ_３３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、又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わし、互いに同一又は異なっていてもよい）、また、Ｘ_２は前記一般式（２３）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の少なくともいず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。
これらの置換基としては、例えば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。

However, in the general formula (24), 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, or naphthyl. An aryl group such as a group, an alkoxy group such as a halogen atom, a cyano group, a nitro group, a methoxy group or an ethoxy group, a —COOR ₃₁ group (where R ₃₁ is a hydrogen atom, an optionally substituted methyl group) , An alkyl group such as an ethyl group, an optionally substituted benzyl, an aralkyl group such as a phenethyl group, an optionally substituted aryl group such as a phenyl group or a naphthyl group), or -CONR ₃₂ R _{33 (provided} that, R ₃₂ and R ₃₃ 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, Rui aralkyl groups such as phenethyl group, or a substituent a phenyl group which may have a represents an aryl group such as a naphthyl group, may be the same or different from one another), also, X ₂ is the formula ( 23) represents the same substituent as X ₁ , a single bond, and an alkylene group.
However, Y, at least one oxycarbonyl group in X _2, a cyano group, an alkenylene group, and an aromatic ring.
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. Moreover, about the number of these functional groups in the radically polymerizable monomer which does not have a charge transport structure, it is preferable that it is polyfunctional and more preferable is trifunctional or more. When only a monofunctional and sometimes bifunctional radically polymerizable monomer is used, the crosslink density in the surface layer becomes dilute, and a dramatic wear resistance effect may not be obtained.
Further, even when a polymer material is contained in the surface layer, the development of the three-dimensional network structure is hindered and the degree of crosslinking is lowered, so that sufficient wear resistance may not be obtained. Furthermore, the compatibility between the polymer material and the cured product resulting from the reaction of the radically polymerizable composition (radically polymerizable monomer or radically polymerizable compound having a charge transporting structure) is deteriorated, and localized due to phase separation. Wear may occur and appear as scratches on the surface.
A compound having a tri- or higher functional acryloyloxy group may be subjected to an ester reaction or a transesterification reaction using, for example, a compound having three or more hydroxyl groups in the molecule and acrylic acid (salt), acrylic acid halide, or acrylic ester. Can be obtained. 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 transport structure include the following, but are not limited to these compounds.
Examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified (alkylene-modified) trimethylolpropane triacrylate, and EO-modified (ethyleneoxy-modified) trimethylol. Propane triacrylate, PO-modified (propyleneoxy-modified) trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified (epichlorohydrin modified) glycerol triacrylate EO modified glycerol triacrylate, PO modified glycerol triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl modified dipentaerythritol Pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, 2,2,5,5,- Tetrahydroxymethylcyclopentanone tetraacrylate, etc. It is. The reason for the modification is to lower the viscosity of the monomer and make it easier to handle.

  Since the radically polymerizable monomer having no charge transporting structure used in the present invention forms a dense crosslink in the surface layer, the ratio of molecular weight to the number of functional groups in the monomer (molecular weight / functional group number) is 250 or less is desirable. If it is larger than 250, the surface layer is soft and wear resistance is somewhat lowered. Therefore, in the monomers exemplified above, monomers having modifying groups such as HPA, EO, PO, etc. have extremely long modifying groups. It is not preferable to use singly.

  The component ratio of the radically polymerizable monomer having no charge transporting structure used for the surface layer is 20 to 80% by mass, preferably 30 to 70% by mass with respect to the total amount of the surface layer. When the monomer component is less than 20% by mass, the three-dimensional cross-linking density of the surface layer is small, and a drastic improvement in wear resistance is not achieved as compared with the case where a conventional thermoplastic binder resin is used. On the other hand, if it exceeds 80% by mass, the content of the charge transporting compound is lowered, resulting in deterioration of electrical characteristics. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally. However, in consideration of the balance of both characteristics, the range of 30 to 70% by mass is most preferable.

-Radical polymerizable compound with charge transport structure-
In the surface layer of the present invention, a radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure are contained, and these radical polymerizable monomers have no charge transport structure. Is incorporated into the cross-linking during curing. The number of functional groups of the radical polymerizable compound having such a charge transporting structure is preferably monofunctional.
By immobilizing a radically polymerizable compound having a monofunctional charge transporting structure in a pendant manner between crosslinks, it is possible to stably maintain high wear resistance and good electrical characteristics over a long period of time. On the other hand, when a radically polymerizable compound having a bifunctional or higher functional charge transporting structure is used as a main component, it is fixed in the crosslinked structure by a plurality of bonds. ) Cannot be kept stable, and the sensitivity may be lowered or the residual potential may be increased due to charge trapping. These appear as image defects such as image density reduction and character thinning. In addition, since the charge transporting structure is very bulky, distortion occurs in the cured resin, the internal stress of the surface layer increases, and cracks may occur.
In addition, in the case where a low molecular charge transport material having no functional group is included in the surface layer instead of the radical polymerizable compound having a charge transport structure, the low molecular charge transport material is used because of its low compatibility. Precipitation and white turbidity may occur, and the mechanical strength of the surface layer may decrease.

Examples of the radical polymerizable compound having a charge transporting structure used in the present invention include a hole transporting structure such as a triarylamine structure, a hydrazone structure, a pyrazoline structure, and a carbazole structure, or a condensed polycyclic quinone, diphenoquinone, a cyano group, and the like. A compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having a radical polymerizable functional group. In the present invention, among these charge transporting structures, a triarylamine structure is particularly effective and useful. Examples of these radical polymerizable functional groups include those shown for the radical polymerizable monomer having no charge transporting structure, and acryloyloxy group and methacryloyloxy group are particularly useful.
Among radically polymerizable compounds having a charge transporting structure, when a compound represented by the structure of the following general formula (5) or (6) is used, high wear resistance is exhibited and electric characteristics are excellent. This is very effective in the present invention.

In general formulas (5) and (6), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₂ (R ₂ is a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group), a carbonyl halide group or CONR ₃ R ₄ (R ₃ and R ₄ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or Represents an aryl group which may have a substituent, and may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same or different May be.
Ar _{3 and} Ar ₄ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group, and Z represents a substituted or unsubstituted alkylene. Represents a group, a substituted or unsubstituted alkylene ether group or an alkyleneoxycarbonyl group, and m and n each represents an integer of 0 to 3;

In the general formulas (5) and (6), examples of the alkyl group in R ₁ 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. As benzyl group, phenethyl group, naphthylmethyl group, and alkoxy groups include methoxy group, ethoxy group, propoxy group, etc., which are halogen atom, nitro group, cyano group, methyl group, ethyl group, respectively. May be substituted with an alkyl group such as methoxy group, ethoxy group, etc., aryloxy group such as phenoxy group, aryl group such as phenyl group, naphthyl group, aralkyl group such as benzyl group, phenethyl group, etc. . Particularly preferred among R ₁ are a hydrogen atom and a methyl group.

Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group. In the present invention, the aryl group includes a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group, and includes the following groups.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an As-indacenyl group, s-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group, Examples include a chrycenyl group and a naphthacenyl group.
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 and 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, it is a C ₁ -C _12, especially C ₁ -C ₈ , more preferably a C ₁ -C ₄ linear or branched alkyl group, and these alkyl groups further include 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 a). R _a 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) Alkyl mercapto group or aryl mercapto group. Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(6) A group represented by the following formula (a).

式中、Ｒ_１０及びＲ_１１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_１０及びＲ_１１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 ₁₀ and R ₁₁ 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, biphenyl group or a naphthyl group, and these may contain an alkoxy group of C ₁ -C _4, alkyl group, or a halogen atom C ₁ -C ₄ as a substituent. R ₁₀ and R ₁₁ may jointly form a ring.
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

The arylene group represented by Ar ₁ and Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .
X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.
The alkylene group for X is a linear or branched alkylene group of C _{1 to} C ₁₂ , preferably C _{1 to} C ₈ , more preferably C _{1 to} C ₄ , and these alkylene groups further include fluorine. atom, a hydroxyl group, a cyano _group, optionally having a C 1 -C ₄ alkoxy group, a phenyl group or a halogen _atom, C 1 -C phenyl group substituted by ₄ alkyl or alkoxy group of _C 1 -C ₄ Also good. 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 cycloalkylene group in _X, a cyclic alkylene group of C 5 -C _7, for these cyclic alkylene group fluorine atom, a hydroxyl _group, an alkyl group of C 1 -C _4, alkoxy group of C 1 -C ₄ etc. You may have the substituent of. Specific examples of the cycloalkylene group include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
The alkylene ether group in X represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the alkylene group of the alkylene ether group is a hydroxyl group, methyl group, ethyl group or the like It may have a group.
The vinylene group in X is represented by the following two structural formulas.

ただし、Ｒ_１２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。

However, R ₁₂ 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, and b is 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.

  More preferred examples of the radically polymerizable compound having a charge transport structure of the present invention include compounds having the following general formula (25).

式中、ｐ、ｑ、ｏはそれぞれ０または１の整数、Ｒ_５は水素原子、メチル基を表わし、Ｒ_６、Ｒ_７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よい。ｓ、ｔは０〜３の整数を表わす。Ｚ_２は単結合、メチレン基、エチレン基、

In the formula, p, q and o are each an integer of 0 or 1, R ₅ represents a hydrogen atom or a methyl group, and R ₆ and R ₇ represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. , A plurality of cases may be different. s and t represent an integer of 0 to 3. Z ₂ is a single bond, a methylene group, an ethylene group,

のいずれかを表わす。
上記一般式（２５）で表わされる化合物としては、Ｒ_６、Ｒ_７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。

Represents one of the following.
As the compound represented by the general formula (25), compounds having a methyl group or an ethyl group are particularly preferable as substituents for R ₆ and R ₇ .

  The radically polymerizable compound having a charge transport structure used in the present invention is polymerized by opening a carbon-carbon double bond on both sides, so that it does not become a terminal structure but is incorporated in a chain polymer and is trifunctional. In the polymer crosslinked by polymerization with the above radical polymerizable monomer, the polymer exists in the main chain of the polymer and in the cross-linked chain between the main chain and the main chain (1 in this cross-linked chain). Intermolecular cross-linked chain between one polymer and another polymer, part of main chain folded in one polymer and other part derived from monomer polymerized in the main chain And an intramolecular cross-linked chain that is cross-linked), whether it is present in the main chain or in the cross-linked chain. The structure consists of at least three ants arranged radially from the nitrogen atom. It is a bulky, but is not directly bonded to the chain part, and is suspended from the chain part via a carbonyl group, etc., so it is fixed in a state that is flexible in three-dimensional positioning. Therefore, these triarylamine structures can be arranged adjacent to each other in the polymer, so that there is little structural distortion in the molecule, and when the surface layer of the electrophotographic photoreceptor is used, the charge is reduced. It is presumed that an intramolecular structure that is relatively free from disruption of the transport pathway can be taken.

  In the present invention, the specific acrylate compound represented by the following general formula (26) can also be used favorably as a radical polymerizable compound having a charge transporting structure.

Ａｒ_５は、置換基を持つ又は無置換の芳香族炭化水素骨格からなる一価基、または二価基を表わす。芳香族炭化水素骨格としては、ベンゼン、ナフタレン、フェナントレン、ビフェニル、等が挙げられる。置換基としては、炭素数１〜１２のアルキル基、炭素数１〜１２のアルコキシ基、ベンジル基、ハロゲン原子が挙げられる。また、上記アルキル基、アルコキシ基は、さらにハロゲン原子、フェニル基を置換基として有していてもよい。
Ａｒ_６は、少なくとも１個の３級アミノ基を有する芳香族炭化水素骨格からなる一価基または二価基、もしくは少なくとも１個の３級アミノ基を有する複素環式化合物骨格からなる一価基または二価基を表わすが、ここで、３級アミノ基を有する芳香族炭化水素骨格とは下記一般式（２７）で表わされる。

Ar ₅ represents a monovalent group or a divalent group having a substituted or unsubstituted aromatic hydrocarbon skeleton. Examples of the aromatic hydrocarbon skeleton include benzene, naphthalene, phenanthrene, biphenyl, and the like. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a benzyl group, and a halogen atom. The alkyl group and alkoxy group may further have a halogen atom or a phenyl group as a substituent.
Ar ₆ is a monovalent group or divalent group composed of an aromatic hydrocarbon skeleton having at least one tertiary amino group, or a monovalent group composed of a heterocyclic compound skeleton having at least one tertiary amino group. Alternatively, it represents a divalent group. Here, the aromatic hydrocarbon skeleton having a tertiary amino group is represented by the following general formula (27).

式中、Ｒ_１３、Ｒ_１４はアシル基、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基を表わす。Ａｒ_７はアリール基を表わす。ｗは１〜３の整数を表わす。
Ｒ_１３、Ｒ_１４のアシル基としてはアセチル基、プロピオニル基、ベンゾイル基等が挙げられる。
Ｒ_１３、Ｒ_１４の置換もしくは無置換のアルキル基は、Ａｒ_５の置換基で述べたアルキル基と同様である。
Ｒ_１３、Ｒ_１４の置換もしくは無置換のアリール基は、フェニル基、ナフチル基、ビフェニリル基、ターフェニリル基、ピレニル基、フルオレニル基、９，９−ジメチル−２−フルオレニル基、アズレニル基、アントリル基、トリフェニレニル基、クリセニル基に加えて下記一般式（２８）で表わされる基を挙げることができる。

In the formula, R ₁₃ and R ₁₄ represent an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Ar ₇ represents an aryl group. w represents an integer of 1 to 3.
Examples of the acyl group for R ₁₃ and R ₁₄ include an acetyl group, a propionyl group, and a benzoyl group.
The substituted or unsubstituted alkyl group for R ₁₃ and R ₁₄ is the same as the alkyl group described for the substituent for Ar ₅ .
The substituted or unsubstituted aryl group of R ₁₃ and R ₁₄ is a phenyl group, a naphthyl group, a biphenylyl group, a terphenylyl group, a pyrenyl group, a fluorenyl group, a 9,9-dimethyl-2-fluorenyl group, an azulenyl group, an anthryl group, In addition to the triphenylenyl group and the chrysenyl group, a group represented by the following general formula (28) can be exemplified.

式中、Ｂは−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ_２−、−ＣＯ−及び以下の二価基から選ばれる。

In the formula, B is selected from —O—, —S—, —SO—, —SO ₂ —, —CO— and the following divalent groups.

ここで、Ｒ_２１は、水素原子、Ａｒ_５で定義された置換もしくは無置換のアルキル基、アルコキシ基、ハロゲン原子、Ｒ_１３で定義された置換もしくは無置換のアリール基、アミノ基、ニトロ基、シアノ基を表わし、Ｒ_２２は、水素原子、Ａｒ_５で定義された置換もしくは無置換のアルキル基、Ｒ_１３で定義された置換もしくは無置換のアリール基を表わし、ｉは１〜１２の整数、ｊは１〜３の整数を表わす。
Ｒ_２１のアルコキシ基の具体例としては、メトキシ基、エトキシ基、ｎ−プロポキシ基、ｉ−プロポキシ基、ｎ−ブトキシ基、ｉ−ブトキシ基、ｓ−ブトキシ基、ｔ−ブトキシ基、２−ヒドロキシエトキシ基、２−シアノエトキシ基、ベンジルオキシ基、４−メチルベンジルオキシ基、トリフルオロメトキシ基等が挙げられる。
Ｒ_２１のハロゲン原子としてはフッ素原子、塩素原子、臭素原子、ヨウ素原子が挙げられる。
Ｒ_２１のアミノ基としては、ジフェニルアミノ基、ジトリルアミノ基、ジベンジルアミノ基、４−メチルベンジル基等が挙げられる。
Ａｒ_７のアリール基としてはフェニル基、ナフチル基、ビフェニリル基、ターフェニリル基、ピレニル基、フルオレニル基、９，９−ジメチル−２−フルオレニル基、アズレニル基、アントリル基、トリフェニレニル基、クリセニル基を挙げることができる。
Ａｒ_７、Ｒ_１３、Ｒ_１４は、Ａｒ_５で定義されたアルキル基、アルコキシ基、ハロゲン原子を置換基として有していてもよい。
３級アミノ基を有する複素環式化合物骨格としては、ピロール、ピラゾール、イミダゾール、トリアゾール、ジオキサゾール、インドール、イソインドール、ベンズイミダゾール、ベンゾトリアゾール、ベンゾイソキサジン、カルバゾール、フェノキサジン等のアミン構造を有する複素環化合物が挙げられる。これらは、Ａｒ_５で定義されたアルキル基、アルコキシ基、ハロゲン原子を置換基として有していてもよい。
Ｂ_１、Ｂ_２はアクリロイルオキシ基、メタクリロイルオキシ基、ビニル基、アクリロイルオキシ基又はメタクリロイルオキシ基又はビニル基を有するアルキル基、アクリロイルオキシ基又はメタクリロイルオキシ基又はビニル基を有するアルコキシ基を表わす。アルキル基、アルコキシ基は、Ａｒ_５で述べたものが同様に適用される。これらＢ_１、Ｂ_２はどちらか一方のみが存在し、両方の存在は除外される。

Here, R ₂₁ is a hydrogen atom, a substituted or unsubstituted alkyl group defined by Ar ₅ , an alkoxy group, a halogen atom, a substituted or unsubstituted aryl group defined by R ₁₃ , an amino group, a nitro group, Represents a cyano group, R ₂₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group defined by Ar ₅ , a substituted or unsubstituted aryl group defined by R ₁₃ , i is an integer of 1 to 12, j represents an integer of 1 to 3.
Specific examples of the alkoxy group of R ₂₁ include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, 2-hydroxy Examples include ethoxy group, 2-cyanoethoxy group, benzyloxy group, 4-methylbenzyloxy group, trifluoromethoxy group and the like.
Examples of the halogen atom for R ₂₁ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the amino group of R ₂₁ include a diphenylamino group, a ditolylamino group, a dibenzylamino group, and a 4-methylbenzyl group.
Examples of the aryl group of Ar ₇ include a phenyl group, a naphthyl group, a biphenylyl group, a terphenylyl group, a pyrenyl group, a fluorenyl group, a 9,9-dimethyl-2-fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, and a chrysenyl group. Can do.
Ar ₇ , R ₁₃ and R ₁₄ may have an alkyl group, alkoxy group or halogen atom defined by Ar ₅ as a substituent.
Heterocyclic compound skeletons having tertiary amino groups include amine structures such as pyrrole, pyrazole, imidazole, triazole, dioxazole, indole, isoindole, benzimidazole, benzotriazole, benzisoxazine, carbazole, and phenoxazine. The heterocyclic compound which has. These may have an alkyl group, an alkoxy group, or a halogen atom defined by Ar ₅ as a substituent.
B ₁ and B ₂ represent an acryloyloxy group, a methacryloyloxy group, a vinyl group, an acryloyloxy group, a methacryloyloxy group, an alkyl group having a vinyl group, an acryloyloxy group, a methacryloyloxy group, or an alkoxy group having a vinyl group. As the alkyl group and alkoxy group, those described for Ar ₅ are similarly applied. Only _{one of} these B ₁ and B ₂ is present, and the presence of both is excluded.

  Similar to the acrylic ester compound of the general formula (26), a compound of the following general formula (29) can also be used favorably.

一般式（２９）中、Ｒ_８、Ｒ_９は、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、ハロゲン原子を表わし、Ａｒ_７、Ａｒ_８は、置換もしくは無置換のアリール基またはアリーレン基、置換又は無置換のベンジル基を表わす。アルキル基、アルコキシ基、ハロゲン原子は前記Ａｒ_５で述べたものが同様に適用される。
アリール基は、一般式（２７）におけるＲ_１３、Ｒ_１４で定義されたアリール基と同様である。アリーレン基は、そのアリール基から誘導される二価基である。
Ｂ_１〜Ｂ_４は、前記一般式（２６）におけるＢ_１、Ｂ_２と同様の基を表わし、いずれか１つのみが存在し、２つ以上の存在は除外される。ｕは０〜５の整数、ｖは０〜４の整数を表わす。

In general formula (29), R ₈ and R _{9 each} represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a halogen atom, and Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group or An arylene group, a substituted or unsubstituted benzyl group. As the alkyl group, alkoxy group, and halogen atom, those described for Ar ₅ are similarly applied.
The aryl group is the same as the aryl group defined by R ₁₃ and R ₁₄ in the general formula (27). An arylene group is a divalent group derived from the aryl group.
B _{1 to} B ₄ represent the same groups as B ₁ and B ₂ in the general formula (26), and only one of them exists, and the presence of two or more thereof is excluded. u represents an integer of 0 to 5, and v represents an integer of 0 to 4.

The specific acrylic ester compound has the following characteristics.
It is a tertiary amine compound having a stilbene-type conjugated structure, and has a developed conjugated system.
By using such a charge-transporting compound with a conjugated system, the charge injection property at the interface part of the cross-linked layer becomes very good, and intermolecular interaction is inhibited even when immobilized between cross-linked bonds. It has a good characteristic with respect to charge mobility. Further, it has an acryloyloxy group or a methacryloyloxy group having high radical polymerizability in the molecule, so that it rapidly gels during radical polymerization and does not cause excessive crosslinking distortion. The double bond at the stilbene structure in the molecule partially participates in the polymerization, and the polymerization is lower than the acryloyloxy group or methacryloyloxy group. In addition, since the number of cross-linking reactions per molecular weight can be increased due to the use of double bonds in the molecule, the cross-linking density can be increased, and further improvement in wear resistance can be realized. .
In addition, the degree of polymerization of this double bond can be adjusted depending on the crosslinking conditions, and an optimum crosslinked film can be easily produced. Such cross-linking participation in radical polymerization is a specific feature of the acrylate compound and does not occur in the α-phenylstilbene type structure as described above.

  From the above, while using the charge transporting compound having a radical polymerizable functional group represented by the general formula (26), particularly the general formula (29), good electrical characteristics are maintained, cracks, etc. It is possible to form a film having a very high crosslink density without causing the occurrence of defects, thereby satisfying various characteristics of the photoreceptor, and preventing the silica fine particles and the like from being stuck in the photoreceptor, and images such as white spots Defects can be reduced.

  Regarding the number of radically polymerizable functional groups, those having a small number of functional groups are preferable for the uniformity of the crosslinked structure, and those having a large number of functional groups are preferable for wear resistance. In the present invention, it is possible to select and use it well from the balance of both.

  The radical polymerizable compound having a charge transporting structure used in the present invention is important for imparting the charge transport performance of the surface layer, and this component is 20 to 80% by mass, preferably 30 to 70%, based on the total amount of the surface layer. The content of the coating liquid component is adjusted so as to be mass%. If this component is less than 20% by mass, the charge transport performance of the surface layer cannot be maintained sufficiently, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential appear with repeated use. On the other hand, if it exceeds 80% by mass, the content of the tri- or higher functional radical polymerizable monomer having no charge transport structure is lowered, resulting in a decrease in the crosslink density, and high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but the range of 30 to 70% by mass is most preferable in consideration of the balance of both characteristics.

  The surface layer of the present invention becomes more effective by curing a tri- or higher functional radical polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a monofunctional charge transporting structure. Monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers can be used in combination for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the surface layer, reduction of surface energy and reduction of friction coefficient. 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, bisphenol A-EO modified diacrylate, bisphenol F-EO modified diacrylate, neopentyl glycol diacrylate, and the like.

  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 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 radical polymerizable compound having a monofunctional charge transport structure. In order to advance this crosslinking reaction efficiently, a polymerization initiator may be used.

  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, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, t-butyl hydroperoxide, cumene hydroperoxide, Peroxide initiators such as lauroyl peroxide, azo series such as azobisisobutylnitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4'-azobis-4-cyanovaleric acid Initiators are mentioned.

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 may contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, antioxidants, and low molecular charge transport agents having no radical reactivity. Can be contained. 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.

Examples of the antioxidant include the following.
(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] Glycol esters, tocopherols, etc.
(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 this invention is 0.01-10 mass% with respect to the total mass of the layer to add.

  The surface layer of the present invention is formed by applying and curing a coating liquid containing at least a trifunctional or higher-functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a monofunctional charge transport structure. Is done. When the radically polymerizable monomer is a liquid, such a coating liquid can be applied by dissolving other components in the liquid, but if necessary, it is diluted with a solvent and applied. Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. Ethers such as dichloromethane, halogens such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolve (registered trademark) 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 liquid, energy is applied from the outside to be cured to form a surface layer. The external energy used at this time includes heat, light, and radiation. The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves. The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. If the heating temperature is lower than 100 ° C., the reaction rate is slow and the reaction is not completely completed. When the temperature is higher than 170 ° C., the reaction proceeds non-uniformly and a large strain is generated in the surface layer. In order to advance the curing reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 100 ° C. and then heating to 100 ° C. or more. As the energy of light, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly have an emission wavelength in ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radically polymerizable substances and photopolymerization initiators. Is possible. Irradiation light amount is 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, it takes time for the curing reaction is less than 50 mW / cm ^2. If it is higher than 1000 mW / cm ^2, the progress of the reaction becomes non-uniform and the surface layer becomes very rough. Examples of radiation energy include those using electron beams. Among these energies, those using heat and light energy are useful because of the ease of reaction rate control and the simplicity of the apparatus.
When the surface layer is cured by light energy or radiation energy, drying is preferably performed to remove the residual solvent after curing. The drying temperature and time can be arbitrarily selected depending on the boiling point of the solvent used in the surface layer coating solution, but are preferably about 100 ° C. to 150 ° C. and about 10 minutes to 30 minutes.
The film thickness of the surface layer is 1 μm to 8 μm, preferably 2 μm to 6 μm. When the thickness is less than 1 μm, the surface layer may be peeled off by long-term use in the image forming process. On the other hand, if it is thicker than 8 μm, the residual potential increases, which may cause a decrease in image density.

  In the composition contained in the surface layer coating solution, it is also possible to contain a radical polymerizable compound having a bifunctional or higher charge transporting structure or a binder resin, which impairs the surface properties, electrical characteristics, or durability of the photoreceptor. This is possible if there is no range. However, when a radically polymerizable compound having a bifunctional or higher functional charge transporting structure is contained, internal stress is generated during the curing reaction due to the bulk of the charge transporting structure, and irregularities are likely to occur on the surface. In addition, when a polymer material such as a binder resin is included in the coating liquid, a polymer formed by a curing reaction of a radical polymerizable composition (radical polymerizable monomer and radical polymerizable compound having a charge transporting structure) is formed. Due to the poor compatibility, phase separation occurs and the surface of the crosslinked layer becomes uneven. Therefore, it is preferable not to use a radical polymerizable compound having a bifunctional or higher functional charge transporting structure or a binder resin.

  As for the dilution solvent of the coating solution, if a large amount of a solvent that dissolves the lower layer is used in a large amount, a composition such as a resin binder or a low molecular charge transport agent in the lower layer is mixed into the outermost surface layer, which hinders the curing reaction. Instead, it becomes the same state as when a large amount of the non-curing material is previously contained in the coating solution, which causes disorder of the crosslinked surface. Conversely, when a solvent that does not dissolve the lower layer at all is used, the adhesion between the surface layer and the lower layer is reduced, and crater-like repellency appears on the surface layer due to volume shrinkage during the curing reaction, resulting in a severe surface roughness. These measures include using a mixed solvent to control the solubility of the lower layer, reducing the amount of solvent contained in the outermost coating layer by liquid composition and coating method, and using a polymer charge transport agent in the lower layer. For example, an intermediate layer having low solubility or an intermediate layer having good adhesiveness may be provided between the lower layer and the surface layer to suppress mixing of lower layer components.

  In the 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 curing after such surface layer coating, if very high energy is applied from the outside and the reaction proceeds rapidly, the curing proceeds unevenly and the unevenness of the cross-linked film surface becomes severe. For this reason, the thing using the heat | fever which can control reaction rate according to heating conditions, light irradiation intensity | strength, and the amount of polymerization initiators, or the external energy of light is preferable.

(Underlayer)
In the electrophotographic photosensitive member of the present invention, an undercoat layer can be provided between the conductive support (31) and the photosensitive layer. These subbing layers generally contain a resin as a main component. However, considering that these resins are coated with a charge generation layer and a charge transport layer with a solvent, these subbing layers have a solvent resistance to general organic solvents. It is desirable to use a high resin. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymerized polyamide (copolymerized nylon) and methoxymethylated polyamide (nylon), polyurethane, melamine resin, and phenol. Examples thereof include curable resins that form a three-dimensional network structure, such as resins, alkyd-melamine resins, isocyanates, and epoxy resins.
In addition, it is possible and effective to add a metal oxide to the undercoat layer in order to prevent moire and reduce residual potential. Moire is a type of image defect in which interference fringes called moire are formed in an image by optical interference when writing with coherent light such as laser light. Basically, it is necessary to contain a material having a large refractive index in order to prevent the occurrence of moire by scattering the incident laser light by the undercoat layer. In order to prevent moiré, a configuration in which an inorganic pigment is dispersed in a binder resin is most effective. As the inorganic pigment used, white pigments are effectively used, and metal oxides such as titanium oxide, zinc oxide, calcium fluoride, calcium oxide, silicon oxide, magnesium oxide, aluminum oxide, tin oxide, and zirconium oxide are used. And indium oxide.
In addition, the undercoat layer preferably has a function of transferring a charge having the same polarity as the charge charged on the surface of the photoreceptor from the charge generation layer to the conductive support side in terms of reducing the residual potential. It also plays that role. For example, in the case of a negatively charged electrophotographic photoreceptor, the residual potential can be reduced by having the undercoat layer have electronic conductivity. As these inorganic pigments, the metal oxides described above are effectively used, but the effect of reducing the residual potential by using an inorganic pigment with low resistance or increasing the addition ratio of the inorganic pigment to the binder resin. On the other hand, the effect of suppressing soiling may be reduced. Therefore, it is necessary to achieve both suppression of background contamination and reduction of residual potential by properly using them according to the layer structure and film thickness of the undercoat layer in the photoreceptor and adjusting the addition amount. In consideration of prevention of moire, increase in residual potential, and suppression of soiling, titanium oxide is most effectively used among the above metal oxides.
These undercoat layers are mainly composed of a binder resin and an inorganic pigment (metal oxide), and can be wet-dispersed in a state including a solvent to obtain a coating dispersion. Examples of the solvent used include acetone, methyl ethyl ketone, methanol, ethanol, butanol, cyclohexanone, cyclopentanone, dioxane, and the like, and mixed solvents thereof. In particular, the inclusion of a part of cyclopentanone provides an effect of enhancing the dispersibility of the inorganic pigment, and may be effective for scumming resistance and stability of the exposed portion potential.
A coating liquid can be obtained by dispersing the inorganic pigment together with a solvent and a binder resin by a conventionally known method such as a ball mill, a sand mill, or an attriler. The binder resin may be added before dispersion or may be added as a resin solution after dispersion. Further, if necessary, a dispersant may be added for the purpose of enhancing the dispersibility of the chemicals, additives, curing accelerators, and inorganic pigments necessary for curing (crosslinking). Using these coating liquids, they are formed on a conductive substrate using a conventionally known method such as dip coating, spray coating, ring coating, beat coating, or nozzle coating. After the application, it can be produced by drying or heating, and if necessary, drying or curing by a curing treatment such as light irradiation. Although the film thickness of an undercoat layer changes with kinds of inorganic pigment to contain, 0-10 micrometers is preferable and 2-7 micrometers is more preferable.
Further, an intermediate layer can be further provided between the conductive support and the undercoat layer or between the undercoat layer and the charge generation layer. The intermediate layer is added to suppress the injection of holes from the conductive support, and the main purpose is to prevent scumming. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble polyamide (soluble nylon), water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As the method for forming the intermediate layer, the above-described method and a known coating method are employed. In addition, 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer. By adopting a two-layer configuration of the intermediate layer and the undercoat layer, it is possible to remarkably enhance the background stain suppression effect.

<About image forming apparatus>
Next, the image forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as means for charging the photosensitive member. 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 method can be used.
In the present invention, not only a contact charging method but also a charging means such as a non-contact proximity arrangement charging method can be effectively used among roller charging devices. Here, the contact charging method is a charging method in which a charging roller, a charging brush, a charging blade, or the like is in direct contact with the photosensitive member. On the other hand, the proximity charging method is, for example, a type in which the charging roller is arranged in a non-contact state so as to have a gap of 200 μm or less between the surface of the photoreceptor and the charging means. If this gap is too large, the charging tends to become unstable, and if it is too small, the surface of the charging member may be contaminated when toner remaining on the photoreceptor exists. is there. Accordingly, the gap is suitably 10 to 200 μm, preferably 10 to 100 μm.
Next, the image exposure unit (5) is used to form an electrostatic latent image on the uniformly charged photoreceptor (1). As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Next, the developing unit (6) is used to visualize the electrostatic latent image formed on the photoreceptor (1). Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
Next, a transfer charger (10) is used to transfer the toner image visualized on the photoconductor onto the transfer body (9). In addition, a pre-transfer charger (7) may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.
Next, a separation charger (11) and a separation claw (12) are used as means for separating the transfer body (9) from the photoreceptor (1). As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger (11), the charging means can be used.
Next, a fur brush (14) and a cleaning blade (15) are used to clean the toner remaining on the photoreceptor after transfer. Further, a pre-cleaning charger (13) may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.
Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a charge removal charger are used, and the exposure light source and the charging means can be used respectively.
In addition, known processes can be used for paper feeding, fixing, paper ejection and the like.

The present invention is 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. 3, the surface of the photoconductor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. 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.

  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.

<Synthesis example of compound having monofunctional charge transport structure>
The compound having a monofunctional charge transport structure in the present invention is synthesized, for example, by the method described in Japanese Patent No. 3164426. An example of this is shown below.

(1) Synthesis of hydroxy group-substituted triarylamine compound (the following structural formula B) 113.85 g (0.3 mol) of a methoxy group-substituted triarylamine compound (the following structural formula A) and 138 g (0.92 mol) of sodium iodide To this, 240 ml of sulfolane was added and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%) of white crystals of the following structural formula B was obtained.
Melting point: 64.0-66.0 ° C

(2) Triarylamino group-substituted acrylate compound 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 water was added in a nitrogen stream. An aqueous sodium oxide 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, 80.73 g (yield = 84.8%) of white crystals of the following compound was obtained.
Melting point: 117.5-119.0 ° C

A subbing layer of 3.5 μm was formed by applying and drying a coating liquid for an undercoat layer of the following composition on an aluminum cylinder having a diameter of 60 mm.
[Coating liquid for undercoat layer]
Alkyd resin: 6 parts (Beccosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin: 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide: 40 parts Methyl ethyl ketone: 50 parts

Subsequently, a 0.2 μm charge generation layer was formed by applying and drying a charge generation layer coating solution having the following composition on the undercoat layer.
[Coating liquid for charge generation layer]
Titanyl phthalocyanine pigment showing the X-ray diffraction spectrum of FIG. 4: 1.5 parts polyvinyl butyral: 1.0 part (XYHL, manufactured by UCC)
Methyl ethyl ketone: 80 parts

Subsequently, a charge transport layer coating liquid having the following composition was applied onto the charge generation layer and dried to form a 22 μm charge transport layer.
[Coating liquid for charge transport layer]
Charge transport material represented by formula (8): 10 parts Bisphenol Z polycarbonate: 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.)
2.6-di-tert-butyl-4-methylphenol: 0.2 part (manufactured by Wako Pure Chemical Industries, Ltd.)
Sanol LS2626: 0.5 part (Ciba Japan)
Tetrahydrofuran: 100 parts Silicone oil: 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

Further, a surface layer was formed on the charge transport layer. The filler was dispersed in a 50 cc glass pot by placing an alumina ball having a diameter of 5 mm, and the following filler, polycarboxylic acid compound and cyclopentanone were further dispersed in a ball mill for 24 hours (150 rpm).
Then, the coating liquid for surface layers was produced by mixing the mill base obtained by adding tetrahydrofuran and stirring and the solution which mixed other materials previously.
The coating solution for the surface layer was spray-coated on the charge transport layer, and was cured by irradiating with ultraviolet rays while rotating the support at 30 rpm using an ultraviolet irradiation device Fusion UV lamp system. A V bulb was used for the ultraviolet irradiation lamp, the distance between the ultraviolet lamp and the photosensitive member surface was 50 mm, the irradiation intensity was 500 mW / cm ^2, and ultraviolet irradiation was performed for 50 seconds to cure the coating film. After the ultraviolet irradiation, drying was performed at 130 ° C. for 20 minutes to provide a surface layer having a thickness of 4 μm, and the electrophotographic photosensitive member of the present invention was produced.

[Coating liquid for surface layer]
(Mill base)
Alumina filler: 8 parts (Sumicorundum AA-03, average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.)
Polycarboxylic acid compound: 0.2 parts (BYK-P104, nonvolatile content 50%, manufactured by BYK Chemie)
Cyclopentanone: 8 parts Tetrahydrofuran: 12 parts

(Coating liquid for surface layer)
Millbase: 3 parts Radical polymerizable compound having no charge transporting structure: 5 parts (KAYARAD TMPTA, Nippon Kayaku Co., Ltd., molecular weight: 296, functional group number: trifunctional, molecular weight / functional group number = 99)
Radical polymerizable compound having the following monofunctional charge transport structure: 5 parts

光重合開始剤： １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・ケミカルズ社製）
テトラヒドロフラン： ５０部

Photopolymerization initiator: 1 part (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184, manufactured by Ciba Specialty Chemicals)
Tetrahydrofuran: 50 parts

  In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) was changed to the charge transport material represented by the general formula (9). did.

  In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) was changed to the charge transport material represented by the general formula (10). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (11). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (12). did.

  In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transporting material represented by the general formula (8) was changed to the charge transporting material represented by the general formula (13). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (14). did.

  In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) was changed to the charge transport material represented by the general formula (15). did.

  In Example 1, all except that the charge transporting material represented by the general formula (8) was changed to the charge transporting material represented by the general formula (16), and the antioxidant Sanol LS2626 was not added. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

  In Example 1, the charge transport material represented by the general formula (8) was changed to the charge transport material represented by the general formula (17), and the diamine compound No. 2 was used instead of the sanol LS2626. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 16 was contained.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (18). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (19). did.

  In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) was changed to the charge transport material represented by the general formula (20). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (21). did.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material represented by the general formula (8) in Example 1 was changed to the charge transport material represented by the general formula (22). did.

  In Example 15, diamine compound No. was further added to the charge transport layer. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 7 was added.

  In Example 1, the charge transport material represented by the general formula (8) was converted into a 1: 1 ratio between the charge transport material represented by the general formula (8) and the charge transport material represented by the general formula (13). An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the mixture was changed to a mixture.

  In Example 1, the charge transport material represented by the general formula (8) was converted into a 1: 1 ratio between the charge transport material represented by the general formula (8) and the charge transport material represented by the general formula (20). An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the mixture was changed to a mixture.

  In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 1 part of the charge transport material represented by the general formula (8) was further added to the surface layer.

  An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having the charge transporting structure of the surface layer was changed to the following compound in Example 1.

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the trifunctional or higher functional radical polymerizable monomer having no surface layer charge transporting structure was changed to the following compound.
Trifunctional or higher radical polymerizable monomer dipentaerythritol caprolactone-modified hexaacrylate having no charge transporting structure: 5 parts (KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd., molecular weight: 1947, number of functional groups: 6 functions)

In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure on the surface layer was changed to 2.5 parts, and the same procedure as in Example 1 was performed except that the following compound was added. An electrophotographic photosensitive member was produced.
Trifunctional or higher radical polymerizable monomer dipentaerythritol caprolactone-modified hexaacrylate not having a charge transporting structure: 2.5 parts (KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd., molecular weight: 1947, number of functional groups: 6 functions)

In Example 1, all except that the radical polymerizable compound having a charge transporting structure contained in the protective layer coating solution is 4 parts monofunctional compound and 1 part bifunctional compound having the following structure is 1 part. In the same manner as in Example 1, an electrophotographic photosensitive member was produced.
Radical polymerizable compound having monofunctional charge transport structure: 4 parts

下記構造式で示される２官能の電荷輸送性構造を有するラジカル重合性化合物： １部

Radical polymerizable compound having a bifunctional charge transport structure represented by the following structural formula: 1 part

In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the filler contained in the protective layer coating solution was changed to the following filler.
α-Alumina (Sumicorundum AA-07, average primary particle size: 0.7 μm, manufactured by Sumitomo Chemical Co., Ltd.)

In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the filler contained in the protective layer coating solution was changed to the following filler.
Silica (SO-E2, average primary particle size: 0.5 μm, manufactured by Admatechs)

<Comparative Example 1>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material contained in the charge transport layer was changed to the charge transport material represented by the following structural formula.

<Comparative example 2>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material contained in the charge transport layer was changed to the charge transport material represented by the following structural formula.

<Comparative Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport material contained in the charge transport layer was changed to the charge transport material represented by the following structural formula.

<Comparative example 4>
The same procedure as in Example 1 was conducted except that the radical polymerizable compound having the charge transport structure of the surface layer was not contained and the radical polymerizable monomer having no charge transport structure was changed to 10 parts. An electrophotographic photosensitive member was produced.

<Comparative Example 5>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that no filler was added.

<Comparative Example 6>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution was changed to a coating solution having the following composition and ultraviolet irradiation was not performed.
(Coating liquid for surface layer)
Mill base according to claim 1: 3 parts Polycarbonate: 10 parts (Z Polyca, manufactured by Teijin Chemicals Ltd.)
Charge transport material represented by the above general formula (8): 7 parts Sanol LS2626 (manufactured by Sankyo Kasei Co., Ltd.): 0.5 part 2.6-di-tert-butyl-4-methylphenol: 0.2 part (Wako Pure) Yakuhin Kogyo Co., Ltd.)
Tetrahydrofuran: 600 parts

<Comparative Example 7>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the thickness of the charge transport layer was 28 μm and no surface layer was provided.

(Paper test)
The electrophotographic photosensitive members of Examples 1 to 25 and Comparative Examples 1 to 7 are set in a process cartridge, and further mounted on an Ricoh tandem digital full-color multi-functional peripheral, imagio MPC7500, and a paper passing test of 500,000 A4 sheets is performed. It was. The paper passing test consists of a proximity roller charging method charging means, an exposure means using a semiconductor laser having a wavelength of 655 nm, a developing means having a developer using polymerized toner, a cleaning means using a cleaning blade, and a downstream side of the cleaning means. A process cartridge equipped with a lubricant application means for applying zinc stearate to the surface of the photoreceptor via a brush was used.

Before starting the paper passing test, a potential sensor (surface potential meter Model 344 manufactured by Trek) was attached to the developing unit position of the process cartridge set in the magenta station, and exposure was performed in a normal temperature and humidity environment (23 ° C 55%). The post-potential (VL) was measured, and the post-exposure potential was measured again in the same manner after the 500,000 sheet passing test. Also, before and after the paper passing test, an image having an area ratio of 0% (blank paper), 5%, and 100% (solid) in a normal temperature and humidity environment (23 ° C. 55%) was printed and evaluated. I did it.
Further, the wear amount of the photoreceptor before and after the paper passing test was measured using an eddy current film thickness meter Fischer scope. The film thickness of the photoconductor is measured at 30 points at 10 mm intervals in the axial direction of the photoconductor, the average value thereof is adopted, and the amount of wear (μm) is obtained from the difference in film thickness before and after the paper passing test. It was.
Table 4 shows the results.
The image evaluation was performed by visual evaluation using a loupe for background stains, afterimages, image density fluctuations, resolution, filming (spotted defects), and poor cleaning (striped defects). The image evaluation rank is almost inferior to ◎ and ◎, with almost no defects, but a level that shows no image quality problems. Δ, and the level at which image defects frequently occur and is clearly regarded as a problem is indicated as x.

  From the above results, the electrophotographic photosensitive member of the present invention is stable in high-quality images with little fluctuation in the potential of the exposed area and no occurrence of image defects even after 500,000 sheet passing tests. It became clear that it was maintained. On the other hand, when the specific charge transport material of the present invention was not used, the variation in the exposed portion potential with time increased and the image density variation was observed. In addition, the influence of afterimages increased with the passage of paper. When the surface layer of the present invention did not contain a filler, cleaning failure, filming, and charging roller contamination increased remarkably, and the stability of image quality was greatly reduced. When a crosslinkable resin was not used for the surface layer of the present invention, image density fluctuations and filming tended to deteriorate.

  As described above, in the electrophotographic photosensitive member formed by laminating at least a photosensitive layer and a surface layer on a conductive support, the surface layer has a radical polymerizable monomer having no charge transporting structure and a charge transporting structure. It contains a crosslinkable resin obtained by curing a radically polymerizable compound and a filler, and the photosensitive layer and / or the surface layer is at least one of the charge transport materials represented by the general formulas (1), (2) and (3) By containing one type, not only the wear resistance is improved, but the exposed portion potential is stably maintained even after repeated use, and the occurrence of image defects such as poor cleaning, filming, and fluctuations in image density is recognized. Accordingly, it has been clarified that an electrophotographic photosensitive member, an image forming apparatus, and a process cartridge that can stably maintain a high-quality image even when used repeatedly for a long period of time can be provided.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 5 Image exposure part 6 Developing unit 7 Charger before transfer 8 Registration roller 9 Transfer body 10 Transfer charger 11 Separation charger 12 Separation claw 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 31 Conductive support 32 Photosensitive layer 33 Surface layer 34 Charge generation layer 35 Charge transport layer 36 Undercoat layer 101 Photoconductor 102 Charging means 103 Exposure means 104 Development means 105 Transfer body 106 Transfer means 107 Cleaning means

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 2004-302450 A JP 2004-302451 A JP 2004-302452 A JP-A-3-75660 Japanese Patent Laid-Open No. 5-6011 JP 11-149170 A JP 2004-279939 A

Claims (16)

In an electrophotographic photosensitive member formed by laminating at least a photosensitive layer and a surface layer on a conductive support, the surface layer includes a radical polymerizable monomer having no charge transporting structure and a radical having a charge transporting structure. A charge transport material containing a crosslinkable resin obtained by curing a polymerizable compound and a filler, and wherein the photosensitive layer and / or the surface layer are represented by the general formulas (1), (2) and (3) An electrophotographic photoreceptor comprising a seed.

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)

(In the formula, R _{1 to} R ₄ each independently represent hydrogen, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.)   The electrophotographic photosensitive member according to claim 1, wherein an antioxidant is contained in one or both of the photosensitive layer and the surface layer. 3. The electrophotographic photoreceptor according to claim 1, wherein a diamine compound represented by the following general formula (4) is contained in one or both of the photosensitive layer and the surface layer.

(In the formula, A ₁ and A ₂ represent groups selected from the following (i), (ii), and (iii), and may be the same or different, provided that (i), (ii) for although may be the same or different, each a ₁ and a _2, in the case of (iii) is formed only on one of a ₁ and a _2.
(I) an alkyl group having 1 to 4 carbon atoms _{(ii) -CH 2 (CH 2} ) m Z
(Iii) Aryl Group that may have a Substituent However, Z represents an aryl group, a cycloalkyl group, or a heterocycloalkyl group, and may further have a substituent. M represents an integer of 0 and 1.
In the formula, Ar represents an arylene group which may have a substituent. )   4. The electrophotographic photosensitive member according to claim 1, wherein the radical polymerizable monomer having no charge transporting structure includes a radical polymerizable monomer having 3 or more functional groups.   5. The electrophotographic photosensitive member according to claim 1, wherein the radical polymerizable compound having a charge transporting structure includes a radical polymerizable compound having 1 functional group.   The radical polymerizable monomer having no charge transporting structure and / or the radical polymerizable compound having a charge transporting structure has a functional group selected from the group consisting of an acryloyloxy group and a methacrylyloxy group. The electrophotographic photosensitive member according to any one of claims 1 to 5.   The electrophotographic photoreceptor according to claim 1, wherein the charge transporting structure of the radical polymerizable compound having the charge transporting structure is a triarylamine structure. 8. The electrophotographic photoreceptor according to claim 7, wherein the radical polymerizable compound having the charge transporting structure is one or more of the following general formula (5) or (6).

(In the above formulas (5) and (6), R ₁ 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. Good aryl group, cyano group, nitro group, alkoxy group, —COOR ₂ (R ₂ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Aryl group), a carbonyl halide group, or CONR ₃ R ₄ (R ₃ and R ₄ are a hydrogen atom, a halogen atom, an alkyl group that may have a substituent, or an aralkyl group that may have a substituent. Or an aryl group which may have a substituent, which may be the same or different from each other), Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same It may be different _.Ar 3, r ₄ represents a substituted or unsubstituted aryl group, which may be identical or different .X is a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted Represents an 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 divalent group, or an alkyleneoxycarbonyl divalent group, and m and n are 0. Represents an integer of ~ 3)   The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains a filler, and the filler is a metal oxide.   The electrophotographic photosensitive member according to claim 9, wherein the metal oxide is α-alumina.   11. The electrophotographic photosensitive member according to claim 9, wherein an average primary particle diameter of the filler is 0.1 μm or more and 1.0 μm or less.   12. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is an image forming apparatus having at least a charging unit, an exposing unit, a developing unit, and a transferring unit. An image forming apparatus.   13. The image forming apparatus according to claim 12, further comprising a lubricating substance supply unit that adheres a lubricating substance to the surface of the electrophotographic photosensitive member.   The image forming apparatus according to claim 13, wherein the lubricating substance contains zinc stearate.   The image forming apparatus is a tandem system in which a plurality of image forming elements including the electrophotographic photosensitive member and at least one unit selected from a charging unit, a developing unit, and a lubricating substance applying unit are arranged. The image forming apparatus according to claim 12.   The image forming apparatus main body according to any one of claims 12 to 15, comprising the electrophotographic photosensitive member and at least one means selected from a charging means, a developing means, and a lubricating substance applying means. Process cartridge characterized in that it is possible.

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