JP2007272191A - Electrophotographic photoreceptor and image forming method using the same, image forming apparatus and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that prevents defects of the output picture qualities of an image forming apparatus such as wear or scratches due to repeated use of the photoreceptor, hardly causes image density unevenness and can form an image of high picture quality for a long period of time, by increasing oxidizing gas resistance without decreasing mechanical durability of a photoreceptor when a crosslinkable material is used to improve the wear resistance and scratch resistance of the photoreceptor surface layer. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer and a surface layer formed in order on a conductive support, wherein the surface layer is formed by curing a radical polymerizable monomer having no specified charge transport structure and a radical polymerizable compound having a charge transport structure by using heat, light or ionizing radiation, and the photosensitive layer and/or the surface layer contains an amine compound having a specified structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member such as a copying machine, a laser printer, and a normal facsimile, and a process cartridge, an image forming apparatus, and an image forming method using the same. Specifically, the present invention relates to an electrophotographic photoreceptor excellent in image quality and durability stability, a process cartridge for an image forming apparatus using the same, an image forming apparatus, and an image forming method.

  In recent years, organic photoreceptors have been widely used for electrophotographic photoreceptors (hereinafter also simply referred to as photoreceptors). Organic photoreceptors are advantageous over inorganic photoreceptors due to the fact that materials that can be used for various exposure light sources from visible light to infrared light can be easily developed, materials that are free from environmental pollution can be selected, and manufacturing costs are low. There are many points. However, organic photoconductors have weak physical and chemical strengths, and have drawbacks such that wear and scratches are likely to occur due to long-term use.

  An electrophotographic image forming apparatus is generally an electrophotographic photosensitive member, a charger for charging the electrophotographic photosensitive member, and a latent image for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger. The image forming apparatus includes an image forming device, a developing device that attaches toner to an image portion of an electrostatic latent image formed by the latent image forming device, and a transfer unit that transfers the toner attached to the image portion to a transfer object. Some of them are equipped with a cleaning device that removes toner remaining on the surface of the photoreceptor without being transferred, if necessary. Since toner remaining on the surface of the photoconductor after the transfer contributes to image quality deterioration, a cleaning device is employed in many image forming apparatuses.

As the cleaning device, a brush, a magnetic brush, a blade, or the like is generally used. For brush cleaning, polyester and acrylic fibers are used, and are used after optimization by changing the shape of the loop or straight hair, the hardness and thickness of the fibers, and the like. However, brush cleaning makes it difficult to sufficiently remove the toner because fine powder toner slips through the fibers. In addition, a magnetic brush method has been proposed in which toner is electrostatically removed by an electric field fire on the brush. However, this method also causes a phenomenon that toner scattered by electrostatic force adheres to the photoconductor again. Thorough cleaning is difficult. Therefore, as the current cleaning means, blade cleaning using an elastic blade is mainly used from the standpoint of removal of residual toner, cost, and diameter reduction. In blade cleaning, the photosensitive member surface layer slides in contact with the cleaning blade, toner, etc., and therefore mechanical wear and scratches are likely to occur on the photosensitive member surface.
Due to the characteristics of the apparatus constituent members as described above, a physical external force is directly applied to the surface of the photoconductor, so that the photoconductor has been required to be durable.

  On the other hand, many research examples have been reported in which a protective layer is provided on the outermost surface of the photoreceptor and inorganic fine particles are dispersed in the protective layer to improve mechanical durability. For example, Japanese Patent Application Laid-Open No. 2002-139859 (Patent Document 1) proposes an electrophotographic photosensitive member in which at least a photosensitive layer and a protective layer containing a filler are sequentially formed on a conductive support.

  As another means, many research examples have been reported that improve by increasing the hardness of the photoreceptor surface. For example, in Japanese Patent Application Laid-Open Nos. 2001-125286 and 2001-324857 (Patent Documents 2 and 3), when a magnetic brush type is applied as a charger, magnetic particles are involuntarily transferred onto a photoreceptor. It has been proposed to increase the hardness of the surface layer of the photoconductor in order to prevent the particles from being scratched by being strongly pressed against the photoconductor in the transfer portion or the cleaning portion. Japanese Patent Laid-Open No. 2003-98708 (Patent Document 4) proposes to increase the hardness of the photoconductor in order to suppress photoconductor surface wear when the blade-type cleaning method is applied.

  As specific means for increasing the surface hardness of the photoreceptor as described above, it has been proposed to use a crosslinkable material such as a thermosetting resin or a UV curable resin as a constituent component of the photoreceptor surface layer. . For example, a technique for improving the wear resistance and scratch resistance of a surface layer by applying a thermosetting resin as a binder component of the surface layer is disclosed in JP-A-5-181299, JP-A-2002-6526 and the like. This is proposed in Japanese Unexamined Patent Application Publication No. 2002-82465 (Patent Documents 5 to 7). Further, in JP 2000-284514 A, JP 2000-284515 A, JP 2001-194413 A (Patent Documents 8 to 10), etc., by using a siloxane resin having a crosslinked structure as a charge transport material, It has been proposed to improve wear and scratch resistance. Furthermore, in Japanese Patent Nos. 3194392 and 3286704 (Patent Documents 11 and 12), in order to improve wear resistance and scratch resistance, both the binder and the charge transport material have a carbon-carbon double bond. A technique using a charge transport material having a carbon-carbon double bond and a binder resin has been reported.

  However, there are many problems such as that sufficient mechanical durability cannot be obtained even with the one described in the report shown here, and the electrical characteristics to be provided as an electrophotographic photosensitive member are insufficient. For example, Japanese Patent No. 3286704 (Patent Document 12) describes one using a polyfunctional acrylate monomer as a composition of the surface layer in order to improve wear resistance and scratch resistance. However, there is no specific description about the charge transporting material, and if a low molecular charge transporting material is simply included in the surface layer, there may be a problem in compatibility with the cured product of the monomer, In some cases, there may be problems such as bleed of low molecular components or a decrease in mechanical durability of the surface layer. In addition, there is a description that a polycarbonate resin is contained for improving the compatibility, but the content in the surface layer of the polyfunctional acrylic monomer is lowered, so that a desired mechanical durability cannot be obtained. And sufficient wear resistance cannot be achieved. Further, there is a description that the surface layer can be a thin film when the surface layer does not contain a charge transporting material. However, in the case of a photoreceptor having a surface layer as shown here, the lifetime is taken as a measure of the life until the surface layer is worn away, and when the surface layer is a thin film, the time until the wear disappears. Is short, so it is difficult to call a long-life photoconductor.

  Japanese Patent No. 3194392 also provides a charge transport layer formed using a coating liquid comprising a monomer having a carbon-carbon double bond, a charge transporting material having a carbon-carbon double bond, and a binder resin. (Patent Document 11). In this patent, the binder may be a compound having a carbon-carbon double bond and reactivity to the charge transporting material, or having no carbon-carbon double bond and having a charge transporting material. It may be a compound having no reactivity with respect to. The photoreceptor described in this patent document has both wear resistance and electrical characteristics, and is notable. However, when a non-reactive compound is used as the binder resin, the monomer and the charge transport material The compatibility with the cured product produced by the reaction is poor, resulting in a decrease in surface smoothness due to layer separation or the like, a resulting poor cleaning property and a decrease in image quality. Moreover, even if it has reactivity, the compound shown as a specific example in this patent document is bifunctional, and it was difficult to obtain a sufficient crosslinking density. For these reasons, the wear resistance is still not satisfactory.

  Thus, in order to obtain the desired mechanical durability, it is necessary to sufficiently study the material constituting the surface layer.

  Further, even if the above-described problems are overcome and a photosensitive member having excellent mechanical durability is obtained, new problems relating to image quality such as image density unevenness occur. That is, in order to crosslink the surface layer, it is necessary to apply heat or light energy, but the influence on the material constituting the photoreceptor (including charge generating material and charge transporting material) cannot be ignored. For example, it is known that titanyl phthalocyanine pigments and the like widely used as charge generation materials have reduced charge generation ability due to the removal of adsorbed water when heat is applied. In addition, many of the triphenylamine materials widely used as charge transport materials have absorption in short-wavelength light such as ultraviolet rays. May cause formation. In addition, in organic photoreceptors, since the constituent materials are not resistant to heat and light, there is a concern that problems relating to image quality such as uneven image density due to reduced durability of oxidizing gas may occur. In particular, when a photoconductor excellent in mechanical durability is used, the image density unevenness can be a serious problem due to the generation mechanism.

As image density unevenness, for example, a decrease in chargeability of the photoreceptor due to an oxidizing gas and a decrease in resistance on the outermost surface due to deposition of an ionic substance on the photoreceptor surface have been confirmed. The former appears as a phenomenon in which, in the charging process, the potential cannot be increased to a desired charging potential, and the image density increases at the portion where the charging property is reduced. On the other hand, the latter appears as a phenomenon that the electrostatic latent image formed in the exposure process cannot be maintained due to the low surface resistance of the photoreceptor, and the image density is lowered.
Although the mechanism of occurrence of these image density unevenness is not clearly understood, it is considered that the cause is as follows.

  Regarding the lowering of the chargeability of the laminate constituting the former photoreceptor, it is considered that the oxidizing gas generated by a charger or the like diffuses into the interior of the photoreceptor and is caused by deterioration of the material. Since the crosslinkable surface layer as in the present invention is considered to have high gas permeability because it causes crosslink shrinkage during film formation, a photoconductor mainly composed of a thermoplastic material as used so far It is considered that material deterioration is likely to occur even inside.

  Regarding the latter, the resistance of the outermost surface of the photoconductor is reduced, and the ionic substance derived from the oxidizing gas generated by the charger is deposited on the surface of the photoconductor and absorbs moisture. The main cause is considered to be that the charge on the latent image moves laterally on the surface of the photoreceptor. Conventional photoconductors have poor mechanical durability, so that ionic substances deposited on the surface by a mechanical external force such as a cleaning blade are easily removed along with wear of the photoconductor. For this reason, the image density unevenness hardly appears, and even if it is recognized as a phenomenon, it recovers within a short time and does not become a big problem. However, when a photoconductor excellent in mechanical durability is used, the surface of the photoconductor is difficult to be scraped, and deposited ionic substances are difficult to remove. For this reason, unlike the past, the phenomenon is likely to be manifested, and it is considered that the phenomenon hardly recovers even after use.

  In order to improve such a defect with respect to the output image, JP 2004-317944 A (Patent Document 13) discloses that an antioxidant is added to the charge transport layer. Japanese Patent Laid-Open No. 2004-240047 (Patent Document 14) discloses that an antioxidant is added to a surface layer having crosslinkability. When such an additive having only an antioxidant ability is used, the expression of its properties depends on the amount of antioxidant added, so that a considerable amount of addition is necessary to obtain a sufficient effect. However, additives such as those disclosed in the above-mentioned published technology do not have charge transport properties, and therefore, charge transport properties are likely to decrease in proportion to the amount added. In general, an antioxidant is designed to have high charge acceptability so that the antioxidant itself interacts with an oxidizing gas or the like. For this reason, in the case of using a material that mainly crosslinks a radical polymerizable reaction as shown in the present invention, crosslinking is easily inhibited. Because of these characteristics, when an antioxidant is added, the antioxidant function and crosslinkability / charge transportability show a reciprocal relationship, and it has excellent charge transportability, wear resistance, and acid gas durability. It is extremely difficult to design such an electrophotographic photosensitive member, and it is necessary to design an electrophotographic photosensitive member specialized for any of the characteristics.

  As described above, by laminating the crosslinkable surface layer as in the present invention, the photoconductor having mechanical durability has excellent wear resistance and can withstand long-term use. Can be disadvantageous. Therefore, in order to obtain a highly durable photoconductor, it is necessary to take sufficient measures against the material deterioration as described above.

As a countermeasure against material deterioration, for example, an initiator that uses less energy may be selected. When forming a surface layer using a thermosetting material, it is considered effective to use an initiator having a low half-life temperature, for example. In addition, when using a photocurable material, it is considered effective to use an initiator having sufficiently high initiator efficiency even at low illuminance, or using an initiator having a sufficiently large amount of radical generation even at low exposure. . However, when such an initiator is used, it is difficult to obtain a film having a high cross-linking density, or a surface layer having a desired mechanical durability cannot be obtained due to the limitation of the initiator that can be selected. The current situation is that they are not actively used.
As described above, there are still many problems with the means for improving the mechanical durability, and there are almost no reports on improvement of the oxidizing gas durability, and the countermeasures are not sufficient.

JP 2002-139659 A JP 2001-125286 A JP 2001-324857 A JP 2003-98708 A JP-A-5-181299 JP 2002-6526 A JP 2002-82465 A JP 2000-284514 A JP 2000-284515 A JP 2001-194413 A Japanese Patent No. 3194392 Japanese Patent No. 3286704 JP 2004-317944 A JP 2004-240047 A

The present invention has been made in view of the above-mentioned problems of the prior art, and in the case of using a crosslinkable material in order to improve the abrasion resistance and scratch resistance of the photoreceptor surface layer, its mechanical durability is lowered. By improving the oxidation gas durability without causing defects, defects related to the output image quality of the image forming device, such as wear and scratches due to repeated use of the photoreceptor, do not occur, and image density unevenness is less likely to occur. It is an object of the present invention to provide an electrophotographic photosensitive member capable of forming a high-quality image over a long period of time.
Another object of the present invention is to provide an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using the electrophotographic photosensitive member.

That is, the said subject is solved by following (1)-(16) of this invention.
(1) “Radical polymerizability in which an electrophotographic photoreceptor having at least a photosensitive layer and a surface layer in this order on a conductive support, the surface layer does not have a charge transporting structure represented by the following general formula (1) The photosensitive layer and / or the surface layer is formed by curing a monomer and a radically polymerizable compound having a charge transporting structure using at least one of heat, light, and ionizing radiation. An electrophotographic photoreceptor comprising at least one selected from compounds represented by the following general formula (2):

（式中、Ｒ_１１、Ｒ_１２、Ｒ_１３、Ｒ_１４、Ｒ_１５、Ｒ_１６は水素又は

(Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ are hydrogen or

を示し、Ｒ_１７は単結合、アルキレン基、アルキレンエーテル基、ポリオキシアルキレン基、ヒドロキシル基置換アルキレンエーテル基、（メタ）アクリロイルオキシ基置換アルキレンエーテル基、又はオキシアルキレンカルボニル基、ポリ（オキシアルキレンカルボニル）基を示し、Ｒ_１８は水素又はメチル基を示す。但し、Ｒ_１１〜Ｒ_１６が同時に４つ以上が水素であることはない。）

R ₁₇ represents a single bond, an alkylene group, an alkylene ether group, a polyoxyalkylene group, a hydroxyl group-substituted alkylene ether group, a (meth) acryloyloxy group-substituted alkylene ether group, an oxyalkylene carbonyl group, a poly (oxyalkylene carbonyl group) ) Group, and R ₁₈ represents hydrogen or a methyl group. However, four or more of R _{11 to} R ₁₆ are not hydrogen at the same time. )

（式中、Ｒ_２、Ｒ_３は、置換もしくは無置換の芳香族炭化水素基、置換もしくは無置換のアルキル基を表わし、同一でも異なっていてもよい。また、Ｒ_２、Ｒ_３は互いに結合し窒素原子を含む複素環基を形成してもよい。Ａｒ_１、Ａｒ_２は置換もしくは無置換の芳香環基を表わす。ｌ、ｍはそれぞれ０〜３の整数を表わす。ただし、ｌ、ｍが同時に０となることはない。ｎは１〜３の整数を表わす。）」；
（２）「導電性支持体上に、少なくとも感光層、表面層を順に有する電子写真感光体において、該表面層が少なくとも下記一般式（１）で示される電荷輸送性構造を有しないラジカル重合性モノマーと、電荷輸送性構造を有するラジカル重合性化合物を、熱、光、電離性放射線の少なくとも何れかを用いて硬化することにより形成されたものであるとともに、該感光層および／又は該表面層中に下記一般式（３）で示される化合物から選ばれる少なくとも１種を含有することを特徴とする電子写真感光体。

(In the formula, R ₂ and R ₃ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₂ and R ₃ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aromatic ring group, and l and m each represents an integer of 0 to 3, provided that l and m Are not simultaneously 0. n represents an integer of 1 to 3) ";
(2) “Radical polymerizability in which, in an electrophotographic photoreceptor having at least a photosensitive layer and a surface layer in this order on a conductive support, the surface layer does not have at least a charge transporting structure represented by the following general formula (1) The photosensitive layer and / or the surface layer is formed by curing a monomer and a radically polymerizable compound having a charge transporting structure using at least one of heat, light, and ionizing radiation. An electrophotographic photoreceptor comprising at least one selected from compounds represented by the following general formula (3):

（式中、Ｒ_１１、Ｒ_１２、Ｒ_１３、Ｒ_１４、Ｒ_１５、Ｒ_１６は水素又は

(Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ are hydrogen or

を示し、Ｒ_１７は単結合、アルキレン基、アルキレンエーテル基、ポリオキシアルキレン基、ヒドロキシル基置換アルキレンエーテル基、（メタ）アクリロイルオキシ基置換アルキレンエーテル基、又はオキシアルキレンカルボニル基、ポリ（オキシアルキレンカルボニル）基を示し、Ｒ_１８は水素又はメチル基を示す。但し、Ｒ_１１〜Ｒ_１６が同時に４つ以上が水素であることはない。）

R ₁₇ represents a single bond, an alkylene group, an alkylene ether group, a polyoxyalkylene group, a hydroxyl group-substituted alkylene ether group, a (meth) acryloyloxy group-substituted alkylene ether group, an oxyalkylene carbonyl group, a poly (oxyalkylene carbonyl group) ) Group, and R ₁₈ represents hydrogen or a methyl group. However, four or more of R _{11 to} R ₁₆ are not hydrogen at the same time. )

（式中、Ｒ_４、Ｒ_５は、置換もしくは無置換の芳香族炭化水素基、置換もしくは無置換のアルキル基を表わし、同一でも異なっていてもよい。また、Ｒ_４、Ｒ_５は互いに結合し窒素原子を含む複素環基を形成してもよい。Ａｒ_３、Ａｒ_４は置換もしくは無置換の芳香環基を表わす。ｌ′、ｍ′はそれぞれ０〜３の整数を表わす。ただし、ｌ′、ｍ′が同時に０となることはない。ｎ′は１〜３の整数を表わす。）」；
（３）「前記感光層および／又は前記表面層中に、さらに前記（１）に記載の一般式（２）で示される化合物から選ばれる少なくとも１種を含有することを特徴とする前記（２）に記載の電子写真感光体」；
（４）「前記表面層に用いる電荷輸送性構造を有しないラジカル重合性モノマーとして、前記一般式（１）で示されるラジカル重合性モノマーと、３官能以上のラジカル重合性モノマーとを混合して用いることを特徴とする前記（１）乃至（３）のいずれかに記載の電子写真感光体」；
（５）「前記表面層に用いられる電荷輸送性構造を有するラジカル重合性化合物の官能基が、アクリロイルオキシ基及び／又はメタクリロイルオキシ基であることを特徴とする前記（１）乃至（４）のいずれかに記載の電子写真感光体」；
（６）「前記表面層に用いられる電荷輸送性構造を有するラジカル重合性化合物の電荷輸送構造が、トリアリールアミン構造であることを特徴とする前記（１）乃至（５）のいずれかに記載の電子写真感光体」；
（７）「前記表面層に用いられる電荷輸送性構造を有するラジカル重合性化合物の官能基数が１つであることを特徴とする前記（１）乃至（６）のいずれかに記載の電子写真感光体」；
（８）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物が、下記一般式（４）又は（５）で示される化合物の一種以上であることを特徴とする前記（７）に記載の電子写真感光体。

(Wherein R ₄ and R ₅ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₄ and R ₅ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₃ and Ar ₄ each represent a substituted or unsubstituted aromatic ring group, and l ′ and m ′ each represent an integer of 0 to 3, provided that l 'And m' are not simultaneously 0. n 'represents an integer of 1 to 3) ";
(3) The above-mentioned (2), wherein the photosensitive layer and / or the surface layer further contains at least one selected from the compounds represented by the general formula (2) described in (1). Electrophotographic photosensitive member as described in the above);
(4) “As a radical polymerizable monomer having no charge transporting structure used for the surface layer, a radical polymerizable monomer represented by the general formula (1) and a tri- or higher functional polymerizable monomer are mixed. The electrophotographic photosensitive member according to any one of (1) to (3) above, which is used;
(5) The above-mentioned (1) to (4), wherein the functional group of the radical polymerizable compound having a charge transporting structure used for the surface layer is an acryloyloxy group and / or a methacryloyloxy group The electrophotographic photosensitive member according to any one of the above;
(6) The charge transport structure of the radical polymerizable compound having a charge transport structure used for the surface layer is a triarylamine structure, according to any one of (1) to (5), Electrophotographic photoreceptor "
(7) The electrophotographic photosensitive member according to any one of (1) to (6) above, wherein the radical polymerizable compound having a charge transporting structure used for the surface layer has one functional group. body";
(8) "The radical polymerizable compound having a monofunctional charge transporting structure used for the surface layer is one or more compounds represented by the following general formula (4) or (5)" The electrophotographic photosensitive member according to (7).

〔式中、Ｒ_６は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を表わす。）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい。）を表わし、Ａｒ_５、Ａｒ_６は置換もしくは無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_７、Ａｒ_８は置換もしくは無置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、アルキレンオキシカルボニル基を表わす。ｊ、ｋは０〜３の整数を表わす。〕」；
（９）「前記表面層に用いられる１官能の電荷輸送性構造を有するラジカル重合性化合物が、下記一般式（６）で示される化合物の一種以上であることを特徴とする前記（７）に記載の電子写真感光体。

[Wherein R ₆ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, A group, an alkoxy group, —COOR ₇ (R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. ), A halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group which may be the same or different from each other. Ar ₅ and Ar ₆ represent a substituted or unsubstituted arylene group and may be the same or different. . Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group. j and k each represents an integer of 0 to 3. ]];
(9) In the above (7), the radical polymerizable compound having a monofunctional charge transporting structure used for the surface layer is one or more of the compounds represented by the following general formula (6): The electrophotographic photosensitive member described.

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

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

を表わす。）」；
（１０）「前記表面層の硬化手段が加熱又は光エネルギー照射手段であることを特徴とする前記（１）乃至（９）のいずれかに記載の電子写真感光体」；
（１１）「前記表面層の硬化手段が光エネルギー照射手段であることを特徴とする前記（１０）に記載の電子写真感光体」；
（１２）「前記表面層の膜厚が１〜１５μｍであることを特徴とする前記（１）乃至（１１）のいずれかに記載の電子写真感光体」；
（１３）「前記感光層が、少なくとも電荷発生層および電荷輸送層を積層した構造であることを特徴とする前記（１）乃至（１２）のいずれかに記載の電子写真感光体」；
（１４）「前記（１）乃至（１３）のいずれかに記載の電子写真感光体を用いて、少なくとも電子写真感光体を帯電させる帯電プロセスと、帯電プロセスによって帯電させられた電子写真感光体表面に静電潜像を形成する潜像形成プロセスと、潜像形成プロセスによって形成された静電潜像にトナーを付着させる現像プロセスと、現像プロセスによって形成されたトナー像を被転写体に転写させる転写プロセスとを繰り返し行なうことを特徴とする画像形成方法」；
（１５）「前記（１）乃至（１３）のいずれかに記載の電子写真感光体と、電子写真感光体を帯電させる帯電器と、帯電器によって帯電させられた電子写真感光体表面に静電潜像を形成する潜像形成器と、潜像形成器によって形成された静電潜像にトナーを付着させる現像器と、現像器よって形成されたトナー像を被転写体に転写させる転写器とを有する画像形成装置」；
（１６）「前記（１）乃至（１３）のいずれかに記載の電子写真感光体と、少なくとも電子写真感光体を帯電させる帯電器と、帯電器によって帯電させられた電子写真感光体表面に静電潜像を形成する潜像形成器と、潜像形成器によって形成された静電潜像にトナーを付着させる現像器と、現像器よって形成されたトナー像を被転写体に転写させる転写器と、転写後に電子写真感光体表面に残留したトナーを電子写真感光体表面から除去するクリーニング器からなる群から選ばれた一つの手段を有するものであって、画像形成装置本体に着脱可能としたことを特徴とする画像形成装置用プロセスカートリッジ」。

Represents. ) ”;
(10) "The electrophotographic photosensitive member according to any one of (1) to (9) above, wherein the curing means for the surface layer is a heating or light energy irradiation means";
(11) "The electrophotographic photosensitive member according to (10) above, wherein the surface layer curing means is light energy irradiation means";
(12) “The electrophotographic photosensitive member according to any one of (1) to (11) above, wherein the surface layer has a thickness of 1 to 15 μm”;
(13) "The electrophotographic photosensitive member according to any one of (1) to (12) above, wherein the photosensitive layer has a structure in which at least a charge generation layer and a charge transport layer are laminated";
(14) “Using the electrophotographic photosensitive member according to any one of (1) to (13), a charging process for charging at least the electrophotographic photosensitive member, and a surface of the electrophotographic photosensitive member charged by the charging process A latent image forming process for forming an electrostatic latent image on the substrate, a developing process for attaching toner to the electrostatic latent image formed by the latent image forming process, and a toner image formed by the developing process being transferred to a transfer target. An image forming method characterized by repeating the transfer process ”;
(15) “The electrophotographic photosensitive member according to any one of (1) to (13)”, a charger for charging the electrophotographic photosensitive member, and an electrostatic surface on the surface of the electrophotographic photosensitive member charged by the charger. A latent image forming device that forms a latent image, a developing device that attaches toner to the electrostatic latent image formed by the latent image forming device, and a transfer device that transfers the toner image formed by the developing device to a transfer medium. An image forming apparatus having a "
(16) “An electrophotographic photosensitive member according to any one of (1) to (13)”, a charger for charging at least the electrophotographic photosensitive member, and a surface on the surface of the electrophotographic photosensitive member charged by the charger. A latent image forming device for forming an electrostatic latent image, a developing device for attaching toner to the electrostatic latent image formed by the latent image forming device, and a transfer device for transferring the toner image formed by the developing device to a transfer target And a means selected from the group consisting of a cleaning device that removes toner remaining on the surface of the electrophotographic photosensitive member after transfer from the surface of the electrophotographic photosensitive member, and is detachable from the image forming apparatus main body. A process cartridge for an image forming apparatus ".

  In the electrophotographic photoreceptor having at least a photosensitive layer and a surface layer in this order on a conductive support of the present invention, the surface layer does not have at least the charge transporting structure represented by the general formula (1). It is formed by curing a monomer and a radically polymerizable compound having a charge transporting structure, and in the photosensitive layer and / or the surface layer, the above general formula (2) and / or (3) The electrophotographic photoreceptor characterized by containing at least one selected from the compounds shown is excellent in mechanical durability, crack resistance, and abrasion resistance, and excellent in image density unevenness over a long period of time. The image quality can be maintained and the durability against an oxidizing gas generated by a charger or the like is excellent. In addition, an image forming method, an image forming apparatus, and a process cartridge for an image forming apparatus using the photoconductor of the present invention have high performance and high reliability.

In order to suppress the occurrence of wear and scratches due to repeated use, it is effective that the mechanical strength represented by the hardness and elastic work rate of the surface of the photoconductor is large. Various methods and materials are used to increase these characteristics. Has been developed. In order to increase the mechanical strength, it is generally known to use a crosslinkable material in which molecules are bonded to each other. The crosslinkable material can express various properties by selecting the functional group structure, molecular structure, number of functional groups, etc., and not only the desired mechanical strength but also the electrical properties required for electrophotographic photoreceptors. Recently, it has been attracting attention as a material for electrophotographic photoreceptors because it allows molecular design that also takes into account the physical characteristics.
By using a crosslinkable material for the surface layer of the photoreceptor, it is possible to dramatically improve the mechanical durability, which can greatly reduce image defects caused by wear and scratches. However, it is necessary to apply energy such as heat and light at the time of cross-linking, so that the material constituting the photosensitive layer is deteriorated, which may cause a decrease in electrical characteristics and a decrease in oxidizing gas durability. This may cause a new problem such as uneven image density.

In general, as a mechanism of uneven image density, an oxidizing gas such as NO _X generated by a discharge phenomenon in a charger or the like, or an ionic substance generated by the reaction of the oxidizing gas with a surrounding compound is photosensitive. It is thought to be caused by adsorbing or depositing on the body and reducing the bulk or surface resistance of the photoreceptor. Conventional electrophotographic photoreceptors have poor mechanical durability, and the surface can be easily refaced by a mechanical external force such as a cleaning member. Almost no problem to recover.
However, the electrophotographic photosensitive member having a surface layer excellent in mechanical durability as in the present invention hardly wears even by a mechanical external force, and scratches and defects are hardly generated on the surface of the photosensitive layer over a long period of time. On the other hand, since it is difficult to remove oxidizing gas, ionic substances, and the like from the surface and bulk, deterioration in image quality is likely to be manifested when the durability to oxidizing gas is low.

  The present invention has been made to remedy these problems, and includes a radical polymerizable monomer having no charge transporting structure represented by the following general formula (1) and a radical polymerizable having a charge transporting structure. By adding a surface layer obtained by crosslinking a compound and adding at least one compound selected from the compounds represented by the following general formulas (2) and / or (3) to the photosensitive layer and / or the surface layer In addition, the inventors have found that it is possible to provide a photoreceptor that is extremely excellent in both mechanical durability and oxidizing gas durability and that is free from defects relating to image quality over a long period of time, and has completed the present invention.

（式中、Ｒ_１１、Ｒ_１２、Ｒ_１３、Ｒ_１４、Ｒ_１５、Ｒ_１６は水素又は

(Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ are hydrogen or

を示し、Ｒ_１７は単結合、アルキレン基、アルキレンエーテル基、ポリオキシアルキレン基、ヒドロキシル基置換アルキレンエーテル基、（メタ）アクリロイルオキシ基置換アルキレンエーテル基、又はオキシアルキレンカルボニル基、ポリ（オキシアルキレンカルボニル）基を示し、Ｒ_１８は水素又はメチル基を示す。但し、Ｒ_１１〜Ｒ_１６が同時に４つ以上が水素であることはない。）

R ₁₇ represents a single bond, an alkylene group, an alkylene ether group, a polyoxyalkylene group, a hydroxyl group-substituted alkylene ether group, a (meth) acryloyloxy group-substituted alkylene ether group, an oxyalkylene carbonyl group, a poly (oxyalkylene carbonyl group) ) Group, and R ₁₈ represents hydrogen or a methyl group. However, four or more of R _{11 to} R ₁₆ are not hydrogen at the same time. )

（式中、Ｒ_２、Ｒ_３は、置換もしくは無置換の芳香族炭化水素基、置換もしくは無置換のアルキル基を表わし、同一でも異なっていてもよい。また、Ｒ_１、Ｒ_２は互いに結合し窒素原子を含む複素環基を形成してもよい。Ａｒ_１、Ａｒ_２は置換もしくは無置換の芳香環基を表わす。ｌ、ｍはそれぞれ０〜３の整数を表わす。ただし、ｌ、ｍが同時に０となることはない。ｎは１〜３の整数を表わす。）

(Wherein R ₂ and R ₃ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₁ and R ₂ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aromatic ring group, and l and m each represents an integer of 0 to 3, provided that l and m Are not simultaneously 0. n represents an integer of 1 to 3.)

（式中、Ｒ_４、Ｒ_５は、置換もしくは無置換の芳香族炭化水素基、置換もしくは無置換のアルキル基を表わし、同一でも異なっていてもよい。また、Ｒ_３、Ｒ_４は互いに結合し窒素原子を含む複素環基を形成してもよい。Ａｒ_３、Ａｒ_４は置換もしくは無置換の芳香環基を表わす。ｌ′、ｍ′はそれぞれ０〜３の整数を表わす。ただし、ｌ′、ｍ′が同時に０となることはない。ｎ′は１〜３の整数を表わす。）
以下に本発明について詳細に説明する。

(Wherein R ₄ and R ₅ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₃ and R ₄ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₃ and Ar ₄ each represent a substituted or unsubstituted aromatic ring group, and l ′ and m ′ each represent an integer of 0 to 3, provided that l 'And m' are not 0 at the same time. N 'represents an integer of 1 to 3.)
The present invention is described in detail below.

<Configuration of electrophotographic photosensitive member>
The photoreceptor of this embodiment is a laminate having at least a photosensitive layer and a surface layer in this order on a conductive support. The photosensitive layer may have a single layer structure or a multilayer structure as long as it has a charge generation function and a charge transport function. An example of the embodiment will be described with reference to FIGS.

The cross-sectional view of the electrophotographic photosensitive member shown in FIG. 1 is an example in the case where the photosensitive layer is a single layer, and a photosensitive layer mainly composed of a charge generating substance and a charge transporting substance on a conductive support (31). (34) and a surface layer (35) are provided. The surface layer (35) described here represents the crosslinked surface layer described below.
The cross-sectional views of the electrophotographic photosensitive member shown in FIG. 2 and FIG. 3 are examples in the case where the photosensitive layer is a laminate, and a charge generating layer having a charge generating function and a charge having a charge transporting function on a conductive support. The transport layer is separated and laminated. In the case of adopting this embodiment, as shown in the figure, the order of stacking the charge generation layer and the charge transport layer on the conductive support is not particularly limited, and can be properly used according to the application. A surface layer is laminated on the surface.

《Detailed description of functional additives》
When the surface layer as in the present invention is provided, since it has scratch resistance and abrasion resistance, the surface of the photoreceptor is hardly changed (scratched, worn) by use, and the initial state is maintained for a long period of time. Is possible. On the other hand, image quality degradation by oxidizing gases such as ozone and NO _X generated by such a charger (uneven image density) may occur easily drawbacks.
The mechanism of uneven image density due to the oxidizing gas is that the ionic substance derived from the oxidizing gas generated by the charger is deposited on the surface of the photoconductor and absorbs moisture, thereby reducing the resistance of the outermost surface of the photoconductor. It is considered that the charge on the latent image moves laterally on the surface of the photoreceptor.

The electrophotographic photosensitive member that has been generally used so far has poor mechanical durability, and therefore wear due to a mechanical external force applied by a cleaning blade or the like, and ionic substances deposited on the outermost surface can be easily removed. Further, the image density unevenness was hardly manifested. However, when an electrophotographic photosensitive member having excellent mechanical durability is used, the surface of the photosensitive member is not easily worn, and it is very difficult to remove ionic substances deposited on the surface. Easy to convert. In particular, when a surface layer is formed using a crosslinkable material, the free volume of the surface layer becomes large due to volume shrinkage due to crosslinking, and the inside of the layer is relatively easily affected by ionic substances and oxidizing gases. For this reason, image density unevenness tends to be manifested, and in addition, there is a problem that has not been seen so far, such as slow recovery. In order to solve the problem caused by this oxidizing gas, in the present invention, the photosensitive layer and / or the surface layer contains at least one selected from the compounds represented by the following general formulas (2) and (3). Is effective. The reason for this is not clarified at the present time, but it is presumed that the substituted amino group contained in the structure of the compound effectively suppresses the generation of radical substances with respect to the oxidizing gas. In addition, since the compounds represented by the general formulas (2) and (3) also have a charge transport capability, the compounds themselves do not function as traps for charge carriers, and the electric potential such as increase in residual potential due to addition can be reduced. There is almost no characteristic deterioration.
Therefore, unlike the antioxidants conventionally used as a solution to such problems, the addition of the compound shown in the present invention to the photoreceptor causes a decrease in charge transport ability, inhibition of crosslinking, and a decrease in hardness. Therefore, it is possible to obtain an intended electrophotographic photosensitive member having acid gas durability.

（式中、Ｒ_２、Ｒ_３、Ａｒ_１、Ａｒ_２、ｌ、ｍ、ｎは前記定義と同じ。）

(Wherein R ₂ , R ₃ , Ar ₁ , Ar ₂ , l, m, and n are the same as defined above.)

（式中、Ｒ_４、Ｒ_５、Ａｒ_３、Ａｒ_４、ｌ′、ｍ′、ｎ′は前記定義と同じ。）

(Wherein R ₄ , R ₅ , Ar ₃ , Ar ₄ , l ′, m ′, and n ′ are the same as defined above.)

In these general formulas (2) and (3), specific examples of the aromatic hydrocarbon group represented by R _{2 to} R ₅ include aromatic hydrocarbon ring groups such as benzene, naphthalene, anthracene, and pyrene. Specific examples of the alkyl group represented by R _{2 to} R ₅ include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and an undecanyl group, and an alkyl group having 1 to 4 carbon atoms is preferable. . In addition, examples of the aromatic ring group of Ar _{1 to} Ar ₄ include monovalent to tetravalent aromatic hydrocarbon groups of aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and pyrene, and pyridine, quinoline, thiophene, furan, and oxazole. And monovalent to tetravalent aromatic heterocyclic groups of aromatic heterocyclic rings such as oxadiazole and carbazole. These substituents include those exemplified in the above specific examples of alkyl groups, alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group, or halogen atoms of fluorine atom, chlorine atom, bromine atom and iodine atom. An atom, an aromatic ring group, etc. are mentioned. Furthermore, specific examples of the heterocyclic group in which R ₂ and R ₃ , or R ₄ and R ₅ are bonded to each other and contain a nitrogen atom include a pyrrolidinyl group, a piperidinyl group, and a pyrrolinyl group. In addition, examples of the heterocyclic group jointly containing a nitrogen atom include aromatic heterocyclic groups such as N-methylcarbazole, N-ethylcarbazole, N-phenylcarbazole, indole, and quinoline.

Below, the preferable example of a compound represented by the said General formula (2) or (3) is given. However, the present invention is not limited to these compounds.
The compounds represented by the general formulas (2) and (3) include compounds described in Japanese Patent Publication No. 58-5739, Japanese Patent No. 2529299, and the like. The compound represented can be produced by the so-called modified Wittig reaction or Wittig reaction by the reaction of the corresponding phosphonic acid ester compound or triphenylphosphonium salt compound with the corresponding aldehyde compound, and the general formula (Wittig) The compound represented by 3) can be produced by reducing the compound represented by the general formula (2).

In the present invention, the compounds represented by the general formulas (2) and (3) may be used alone or in combination of two or more.
These compounds may be added to the photosensitive layer or the surface layer, or may be added simultaneously to both the photosensitive layer and the surface layer. Even when the photosensitive layer has a multilayer structure composed of a charge generation layer and a charge transport layer, it may be applied to any layer, or may be applied to two or more layers.
The amount to be added is not particularly limited as long as it satisfies the desired electrical characteristics and mechanical characteristics of the photoreceptor. Specifically, it is preferably 0.01 to 150% by weight based on the total amount of the layer to be added. When the addition amount is less than 0.01% by weight, it is difficult to obtain desired oxidation gas durability. On the other hand, when the addition amount exceeds 150% by weight, sufficient oxidizing gas durability can be obtained, but desired mechanical durability and electrical characteristics may not be obtained, which is not preferable.

<< Detailed description of surface layer >>
Next, the constituent material of the crosslinked surface layer of the present invention will be described.
<Description of radical polymerizable monomer having no charge transport structure>
The radical polymerizable monomer having no charge transporting structure used in the present invention is represented by the general formula (1), and a monomer having 5 or more radical polymerizable functional groups of acryloyloxy group or methacryloyloxy group is present. Preferred for achieving the object of the invention.
R ₁₇ in the general formula (1) is preferably a single bond or a hydroxyl group-substituted alkylene ether group in order to achieve the object of the present invention.
A compound having 5 or more acryloyloxy groups can be prepared by, for example, using a compound having 5 or more hydroxyl groups in the molecule and acrylic acid (salt), acrylate halide, or acrylate ester, and performing ester reaction or transesterification reaction. Obtainable. A compound having 5 or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having 5 or more radical polymerizable functional groups may be the same or different.

As the radical polymerizable monomer having no charge transporting structure represented by the general formula (1), compounds having three acryloyloxy groups and three hydrogen groups with respect to R _{11 to} R ₁₆ , four acryloyloxys A group having two and two hydrogen groups, a compound having five acryloyloxy groups and one hydrogen group, a compound having six acryloyloxy groups, three methacryloyloxy groups and three hydrogen groups. A compound having 4 methacryloyloxy groups and 2 hydrogen groups, a compound having 5 methacryloyloxy groups and 1 hydrogen group, a compound having 6 methacryloyloxy groups, etc. Although the following are illustrated in detail, it is not limited to these compounds.

These may be used alone or in combination of two or more.
These monomers can be exemplified by being produced by esterification of polyhydric alcohols for reasons such as excellent yields, low production costs and high productivity, and more than two types of these monomers. When two, three or four types are used in combination and a monomer having six radical polymerizable functional groups is used, six radical polymerizable functional groups are obtained by esterification in that the yield is excellent. It is preferable to use a mixture of a monomer having a hydrogen atom and a monomer having 5 or less radical polymerizable functional groups in which hydrogen groups remain without being esterified. Furthermore, the blending ratio is preferably 20 to 99% by weight, more preferably 30 to 97% by weight, and still more preferably 20% to 99% by weight of the monomer having the six radical polymerizable functional groups in that the yield is also excellent. Is 40 to 95% by weight. For the same reason, when a monomer having five radical polymerizable functional groups is used, it is preferable to contain 20 to 99% by weight of this monomer, more preferably 30 to 97% by weight, still more preferably 40 to 95% by weight. When a monomer having four radical polymerizable functional groups is used for the same reason, it is preferable to contain 0.01 to 30% by weight of this monomer, more preferably 0.1 to 20% by weight, More preferably, it is 3 to 5% by weight. When a monomer having three radical polymerizable functional groups is used for the same reason, it is preferable to contain this monomer in an amount of 0.01 to 30% by weight, more preferably 0 to 0%. 0.1 to 20% by weight, more preferably 3 to 5% by weight.

More specifically, for the same reason, 30 to 70% by weight, preferably 40 to 60% by weight of a compound having 5 acryloyloxy groups and 1 hydrogen group, and 70 to 30% by weight of a compound having 6 acryloyloxy groups. %, Preferably a mixture containing 60 to 40% by weight, a compound having 5 acryloyloxy groups and one hydrogen group 30 to 65% by weight, preferably 40 to 55% by weight, 6 acryloyloxy groups The compound having 65 to 30% by weight, preferably 55 to 40% by weight, and one, two, three or four selected from the compounds listed below are 0.01 to 5% by weight, preferably Is a mixture containing 1-3% by weight,
-Compound having 1 acryloyloxy group and 5 hydrogen groups-Compound having 2 acryloyloxy groups and 4 hydrogen groups-Compound having 3 acryloyloxy groups and 3 hydrogen groups-4 Compounds having 1 acryloyloxy group and 2 hydrogen groups 5 methacryloyloxy groups and 1 hydrogen group 30-70 wt%, preferably 40-60 wt% and 6 methacryloyloxy groups A mixture containing 70 to 30% by weight, preferably 60 to 40% by weight of a compound having 30 to 65% by weight, preferably 40 to 55% by weight, a compound having 5 methacryloyloxy groups and one hydrogen group, 6 65 to 30% by weight, preferably 55 to 40% by weight of a compound having one methacryloyloxy group, and the compounds listed below One selected from among, two, three or four 0.01 to 5 wt%, preferably a mixture containing 1-3 wt% can be exemplified.
-Compound having 1 methacryloyloxy group and 5 hydrogen groups-Compound having 2 methacryloyloxy groups and 4 hydrogen groups-Compound having 3 methacryloyloxy groups and 3 hydrogen groups-4 Compound having 1 methacryloyloxy group and 2 hydrogen groups

  The component ratio of the radical polymerizable monomer having no charge transporting structure represented by the general formula (1) used for the crosslinked surface layer is preferably 3 to 95% by weight, more preferably based on the total amount of the crosslinked surface layer. 5 to 80% by weight, more preferably 10 to 70% by weight. When the monomer component is 3% by weight or more, the three-dimensional cross-linking density of the cross-linked surface layer is high, and a dramatic improvement in wear resistance is achieved as compared with the case where a conventional thermoplastic binder resin is used. On the other hand, when the content is 95% by weight or less, the content of the charge transporting compound is high and the electrical characteristics are hardly deteriorated.

  In forming the surface layer of the present invention, a 1 to 4 functional radical polymerizable monomer and radical polymerization are used for the purpose of adjusting the viscosity of the coating liquid, maintaining the surface smoothness of the surface layer, preventing cracks due to crosslinking shrinkage, and reducing the surface free energy. May be used in combination. Here, since there is a concern that adding a large amount of a compound having 1 or 2 functional groups may cause mechanical durability of the surface layer, a radically polymerizable monomer and a radically polymerizable oligomer having three or more functions are used in combination. It is preferable to do. Known compounds can be used as these compounds. The blending ratio of the 1-4 functional radical polymerizable monomer and / or radical polymerizable oligomer used in combination is preferably 1 to 80% by weight, more preferably 5 to 60% by weight, and still more preferably. Is preferably 10 to 40% by weight. When a 1-4 functional radically polymerizable monomer and / or radically polymerizable oligomer is used for adjusting the viscosity of the coating liquid, the viscosity of the compound is preferably 1000 mPa · s or less at 25 ° C., more preferably 800 mPa · s. s is good.

  Examples of the 1-4 functional radical polymerizable monomer include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, and PO-modified trimethylolpropane triacrylate. Acrylate, caprolactone modified trimethylolpropane triacrylate, ECH modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, ECH modified glycerol triacrylate, EO Modified glycerol triacrylate, PO-modified glyce Triacrylate, tris (acryloxyethyl) isocyanurate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate 2,2,5,5-tetrahydroxymethylcyclopentanone tetraacrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3- Methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acetate Rate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1, 4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, EO-modified bisphenol F diacrylate, neo Examples include pentyl glycol diacrylate, among which trimethylolpropane triacrylate (TMPTA), HPA-modified trimethylolpropane triacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, ECH-modified trimethylolpropane triacrylate are exemplified, but the present invention is limited to this. It is not a thing. In addition, ethyleneoxy modification is described as EO modification, propyleneoxy modification as PO modification, epichlorohydrin modification as ECH modification, and alkylene modification as HPA modification.

  Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers.

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

〔ただし、式中、Ｘ_１は、置換基を有していてもよいフェニレン基、ナフチレン基等のアリーレン基、置換基を有していてもよいアルケニレン基、−ＣＯ−基、−ＣＯＯ−基、−ＣＯＮ（Ｒ_２０）−基（Ｒ_２０は、水素、メチル基、エチル基等のアルキル基、ベンジル基、ナフチルメチル基、フェネチル基等のアラルキル基、フェニル基、ナフチル基等のアリール基を表わす。）、または−Ｓ−基を表わす。〕

[Wherein, X ₁ is an arylene group such as a phenylene group or a naphthylene group optionally having a substituent, an alkenylene group optionally having a substituent, a —CO— group, a —COO— group. , —CON (R ₂₀ ) — group (R ₂₀ represents an alkyl group such as hydrogen, methyl group or ethyl group, an aralkyl group such as benzyl group, naphthylmethyl group or phenethyl group, or an aryl group such as phenyl group or naphthyl group. Or -S- group. ]

Specific examples of these substituents include a vinyl group, a styryl group, a 2-methyl-1,3-butadienyl group, a vinylcarbonyl group, an acryloyloxy group, an acryloylamide group, and a vinyl thioether group.
Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following formulas.

〔ただし、式中、Ｙは、置換基を有していてもよいアルキル基、置換基を有していてもよいアラルキル基、置換基を有していてもよいフェニル基、ナフチル基等のアリール基、ハロゲン原子、シアノ基、ニトロ基、メトキシ基あるいはエトキシ基等のアルコキシ基、−ＣＯＯＲ_２１基（Ｒ_２１は、水素原子、置換基を有していてもよいメチル基、エチル基等のアルキル基、置換基を有していてもよいベンジル、フェネチル基等のアラルキル基、置換基を有していてもよいフェニル基、ナフチル基等のアリール基を表わす。）または−ＣＯＮＲ_２２Ｒ_２３（Ｒ_２２およびＲ_２３は、水素原子、置換基を有していてもよいメチル基、エチル基等のアルキル基、置換基を有していてもよいベンジル基、ナフチルメチル基、あるいはフェネチル基等のアラルキル基、または置換基を有していてもよいフェニル基、ナフチル基等のアリール基を表わし、互いに同一または異なっていてもよい。）、また、Ｘ_２は上記式のＸ_１と同一の基及び単結合、アルキレン基を表わす。ただし、Ｙ、Ｘ_２の少なくとも何れか一方がオキシカルボニル基、シアノ基、アルケニレン基、及び芳香族環である。〕
これらの置換基を具体的に例示すると、α−塩化アクリロイルオキシ基、メタクリロイルオキシ基、α−シアノエチレン基、α−シアノアクリロイルオキシ基、α−シアノフェニレン基、メタクリロイルアミノ基等が挙げられる。

[Wherein Y represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, an aryl such as a naphthyl group, etc. Group, halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ₂₁ group (R ₂₁ is an alkyl such as hydrogen atom, methyl group which may have a substituent, ethyl group) An aralkyl group such as a benzyl or phenethyl group which may have a substituent, an aryl group such as a phenyl group or a naphthyl group which may have a substituent) or -CONR ₂₂ R ₂₃ (R ₂₂ and R ₂₃ are hydrogen atom, an optionally substituted methyl group, an alkyl group such as ethyl group, optionally substituted benzyl group, naphthylmethyl group or phenethyl, Aralkyl group or substituent a phenyl group which may have a equal, an aryl group such as a naphthyl group, which may be the same or different from each other.) Further, X ₂ is identical to X ₁ of the formula And 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. ]
Specific examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

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

Among these radical polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. In order to have good electrical characteristics over a long period of time, the number of radical polymerizable functional groups is preferably 1. When a bifunctional or higher functional charge transporting compound is used as the main component, the site having the charge transporting structure is fixed in the cross-linked structure by a plurality of bonds, so that the intermediate structure (cation radical) at the time of charge transport is It cannot be maintained stably, and the sensitivity is lowered due to charge trapping, and the residual potential is likely to increase. Such deterioration of the electrical characteristics may appear as a phenomenon such as a decrease in image density and thinning of characters.
A triarylamine structure is highly effective as a charge transporting structure. Furthermore, when a compound represented by the following general formula (4) or (5) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.

〔式中、Ｒ_６は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_７（Ｒ_７は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を表わす。）、ハロゲン化カルボニル基若しくはＣＯＮＲ_８Ｒ_９（Ｒ_８及びＲ_９は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい。）を表わし、Ａｒ_５、Ａｒ_６は置換もしくは無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_７、Ａｒ_８は置換もしくは無置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わす。Ｚは置換もしくは無置換のアルキレン基、置換もしくは無置換のアルキレンエーテル基、アルキレンオキシカルボニル基を表わす。ｊ、ｋは０〜３の整数を表わす。〕

[Wherein R ₆ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, A group, an alkoxy group, —COOR ₇ (R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. ), A halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group which may be the same or different from each other. Ar ₅ and Ar ₆ represent a substituted or unsubstituted arylene group and may be the same or different. . Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group. j and k each represents an integer of 0 to 3. ]

Specific examples of the substituents in the general formulas (4) and (5) are shown below.
In the general formulas (4) and (5), in the substituent of R ₆ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.
Among the substituents for R ₆ , particularly preferred are a hydrogen atom and a methyl group.
Substituted or unsubstituted Ar ₇ and Ar ₈ are aryl groups, and examples of the aryl group include a condensed polycyclic hydrocarbon group, a non-fused cyclic hydrocarbon group, and a heterocyclic group.

  The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.

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

The aryl group represented by Ar ₇ or Ar ₈ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) an alkyl group;
_Preferably, C 1 _{-C 12} especially _C 1 -C _8, more preferably a straight or branched alkyl group of _C 1 -C _4, in the alkyl group a fluorine atom, a hydroxyl group, a cyano group, C ₁ -C ₄ alkoxy group which may have a phenyl group or a halogen _atom, C 1 -C ₄ alkyl or _C 1 -C ₄ phenyl group substituted with an alkoxy group.

  Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.

(3) alkoxy group (—OR ₃₀ );
(In the formula, R ₃₀ represents an alkyl group defined in (2).)
Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.

(4) aryloxy group;
Examples of the aryl group include a phenyl group and a naphthyl group. It _may contain an alkoxy group having C 1 -C _4, alkyl group, or a halogen atom C 1 -C ₄ as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) an alkyl mercapto group or an aryl mercapto group;
Specific examples include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.
(6) a substituent represented by the following formula;

（式中、Ｒｄ及びＲｅ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。Ｒｄ及びＲｅ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。

(In the formula, Rd and Re each independently represent a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. C ₁ -C ₄ alkoxy group, C ₁ -C ₄ alkyl group or halogen atom may be contained as a substituent. Rd and Re may form a ring together.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.

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

Examples of the arylene group represented by Ar ₅ and Ar ₆ include a divalent group derived from the aryl group represented by Ar ₇ and Ar ₈ .

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

The substituted or unsubstituted cycloalkylene _group, a cyclic alkylene group of C 5 -C _7, these are the cyclic alkylene group fluorine atom, a hydroxyl _group, an alkyl group of C 1 -C _4, a C 1 -C ₄ It may have an alkoxy group. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
Examples of the substituted or unsubstituted alkylene ether group include alkyleneoxy groups such as ethyleneoxy group and propyleneoxy group, alkylenedioxy groups derived from ethylene glycol, propylene glycol, and the like, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the like. Examples thereof include a derived di- or poly (oxyalkylene) oxy group, and the alkylene group of the alkylene ether group may have a substituent such as a hydroxyl group, a methyl group, or an ethyl group.
Examples of the vinylene group include substituents represented by the following general formula.

〔式中、Ｒｆ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_７、Ａｒ_８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。〕

[Wherein, Rf 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 ₇ or Ar ₈ above), a is 1 or 2, b Represents 1-3. ]

Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether group include the alkylene ether group represented by X.
Examples of the alkyleneoxycarbonyl group include a caprolactone-modified group.

  Further, the radically polymerizable compound having a monofunctional charge transport structure of the present invention is more preferably a compound having a structure represented by the following general formula (6).

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

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

を表わす。）
上記一般式（６）で表わされる化合物としては、Ｒｂ、Ｒｃの置換基として、特にメチル基、エチル基である化合物が好ましい。

Represents. )
As the compound represented by the general formula (6), compounds having a methyl group or an ethyl group are particularly preferable as substituents for Rb and Rc.

  In the radical polymerizable compound having a monofunctional charge transport structure represented by the general formulas (4) and (5), particularly (6), used in the present invention, the carbon-carbon double bond is opened on both sides. In the polymer formed into a crosslink by polymerization with a radically polymerizable monomer that does not have a terminal structure, is incorporated in a chain polymer, and does not have a charge transporting structure represented by the general formula (1). Is present in the main chain of the polymer and in the cross-linked chain between the main chain and the main chain (this cross-linked chain includes one intermolecular cross-linked chain between one polymer and another polymer, and one cross-linked chain. There is an intramolecular cross-linked chain where the site of the main chain folded in the polymer and the other site derived from the polymerized monomer are cross-linked in the main chain. Whether present in the chain or in the cross-linked chain The suspended triarylamine structure has at least three aryl groups arranged in a radial direction from the nitrogen atom and is bulky, but is not directly bonded to the chain part but from the chain part via a carbonyl group or the like. Because they are suspended and anchored in a flexible manner in steric positioning, these triarylamine structures can be arranged in a polymer in a space adjacent to each other, so When the surface layer of the electrophotographic photosensitive member is small, it is presumed that an intramolecular structure relatively free from interruption of the charge transport path can be taken.

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

  Further, the monofunctional radically polymerizable compound having a charge transporting structure used in the present invention is important for imparting the charge transport performance of the crosslinked surface layer, and this component is 20 to 80% by weight based on the total amount of the crosslinked surface layer. %, Preferably 30 to 70% by weight. When this component is less than 20% by weight, the charge transport performance of the crosslinked surface layer cannot be maintained sufficiently, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential appears with repeated use. On the other hand, if it exceeds 80% by weight, the content of the radically polymerizable monomer not having the charge transport structure represented by the general formula (1) is lowered, resulting in lowering of 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 considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

<Description of initiator>
Further, the surface layer of the present invention comprises at least a radical polymerizable monomer having no charge transporting structure represented by the general formula (1) and a radical polymerizable compound having a charge transporting structure (preferably monofunctional). , A cross-linked surface layer cured simultaneously using at least one of light and ionizing radiation. When forming a cross-linked surface layer using heat energy or light energy, this cross-linking reaction is carried out as necessary. In order to proceed efficiently, a polymerization initiator may be used in the crosslinked surface layer. When performing crosslinking using ionizing radiation, it is usually possible to obtain a crosslinking reaction without using a polymerization initiator, but in order to cure the uncured components remaining after irradiation with ionizing radiation, as a post-treatment Heat energy and / or light energy can be applied, but even in that case, it is effective to add a polymerization initiator shown below.

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

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Photopolymerization initiator, bis (cyclopentadienyl) -di-chloro-titanium, bis (cyclopentadienyl) -di-phenyl-titanium, bis (cyclopentadienyl) -bis ( , 3,4,5,6 pentafluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium, etc. Other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compound, triazine compound, imidazole compound Be .

  Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4'-dimethylaminobenzophenone, and the like.

  These polymerization initiators may be used alone or in combination of two or more. The content of the polymerization initiator is 0.5 to 40 parts by weight, preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total content having radical polymerizability.

<Description of filler addition>
The surface layer of the present invention is obtained by simultaneously curing at least a radical polymerizable monomer having no charge transport structure represented by the general formula (1) and a radical polymerizable compound having a charge transport structure (preferably monofunctional). Although it is a cross-linked surface layer, filler fine particles can be contained for the purpose of improving wear resistance.
The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of the light transmittance and wear resistance of the surface layer. When the average primary particle size of the filler is less than 0.01 μm, it causes a decrease in dispersibility and the effect of improving the wear resistance is not sufficiently exhibited. There is a possibility that the settling property of the toner is promoted and toner filming may occur.

The higher the filler material concentration in the surface layer is, the higher the wear resistance is, and thus the better. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content.
Furthermore, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the fillers. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem. As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable.
The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30% by weight and more preferably 5 to 20% by weight with respect to the filler weight. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These filler materials may be used alone or in combination of two or more.

<Description of other additives>
Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. It is suppressed to 20 parts by weight or less, preferably 10 parts by weight or less with respect to 100 parts by weight. Moreover, 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 parts by weight or less is appropriate.

<About film production method>
The surface layer of the present invention comprises a coating containing at least a radical polymerizable monomer represented by the general formula (1) having no charge transport structure and a radical polymerizable compound having a charge transport structure (preferably monofunctional). It is formed by applying and curing a working solution on a photosensitive layer described later. When the radically polymerizable monomer is a liquid, the coating liquid used for coating can be coated by dissolving other components in the liquid. However, if necessary, the coating liquid is diluted with a solvent and coated. The solvent used here is not particularly limited as long as it is usually used. For example, 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, ethers such as tetrahydrofuran, dioxane and propyl ether, dichloromethane And halogen series such as dichloroethane, trichloroethane and chlorobenzene, aromatic series such as benzene, toluene and xylene, and cellosolv series such as methyl cellosolve, ethyl cellosolve and cellosolve acetate. These solvents may be used alone or in combination of two or more.

  The coating method used for forming the surface layer is not particularly limited as long as it is a commonly used coating method. A coating method may be appropriately selected depending on the viscosity of the coating liquid, the desired film thickness of the surface layer, and the like. Examples include dip coating, spray coating, bead coating, ring coating, and the like.

In this invention, after apply | coating this coating liquid, a surface layer is hardened by giving energy from the outside. As the external energy used at this time, heat energy, light energy, or energy using ionizing radiation can be used. However, when ionizing radiation is used, the energy penetration depth and energy intensity are For this reason, since there is a concern about deterioration of electrophotographic characteristics accompanying deterioration of the constituent material of the electrophotographic photosensitive member, it is preferable to cure using thermal energy and light energy. In addition, since curing using light energy can be expected to reduce the amount of solvent used during production, reduce energy required for crosslinking, and further increase the strength of the crosslinked film, it is more preferable to use light energy and effectively Any two of the above means may be used in combination for crosslinking.
As the thermal energy, air, nitrogen and other gases, steam, various heat media, infrared rays, and electromagnetic waves can be used, and heating is performed from the coated surface side or the support side. The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. When the temperature is lower than 100 ° C., the reaction rate is slow, so that productivity is lowered and unreacted material remains in the film. On the other hand, when the treatment is performed at a temperature higher than 170 ° C., the shrinkage of the film due to the cross-linking is increased, and the skin-like defects and cracks may be generated on the surface, or peeling may occur at the interface with the adjacent layer. Further, when the volatile component in the photosensitive layer is sprayed to the outside, it is not preferable because desired electrical characteristics may not be obtained. When using a resin having a large shrinkage due to crosslinking, it is also effective to complete the crosslinking at a high temperature of 100 ° C. or higher after preliminary crosslinking at a low temperature of less than 100 ° C.

As the light energy, a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc metal halide lamp or the like may be used. The radical polymerizable compound (preferably monofunctional) having a charge transporting structure, and further the absorption property of the photopolymerization initiator used in combination are preferably selected. As the light emission illuminance of the light source used, it is generally preferable to expose with an illuminance of 50 to 2000 mW / cm ² with a wavelength of 365 nm as a reference. Moreover, when the illuminance measurement in the vicinity of the maximum emission wavelength is possible, it is more preferable to expose in the illuminance range. When the illuminance is low, the time required for curing increases, which is not preferable from the viewpoint of productivity. On the other hand, when the illuminance is high, curing shrinkage is likely to occur, and the surface may have a skin-like defect or crack, or may peel at the interface with the adjacent layer.

  Ionizing radiation is radiation that can ionize a substance. Examples include direct ionizing radiation represented by alpha rays and electron beams, and indirect ionizing radiation represented by X rays and neutron rays. It is done. The ionizing radiation that can be used in the present invention is not particularly limited as long as it is generally used, but in view of the influence on the human body, an electron beam is preferable. As an electron beam irradiation device, when using a device using various electron beam accelerators such as a cockroft Walton type, a bandegraph type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, a high frequency type, etc. good. The irradiation amount of the electron beam may be appropriately determined according to the material to be used and the thickness of the crosslinkable surface layer, but it is usually preferable to irradiate electrons having energy of 100 to 1000 keV, preferably 100 to 300 keV, about 0.1 to 30 Mrad. When the irradiation amount is less than 0.1 Mrad, the electron beam cannot reach the crosslinkable surface layer, and there is a possibility that poor curing of the deep layer may occur. On the other hand, when the irradiation amount exceeds 30 Mrad, the electron beam may reach a charge transport layer and a charge generation layer, which will be described later, and may affect the constituent materials of each layer.

At the time of UV irradiation or ionizing radiation irradiation, the temperature of the photoreceptor surface layer rises due to the influence of heat rays generated from the light source. If the surface temperature of the photoconductor rises too much, curing shrinkage of the surface layer is likely to occur, and low molecular components contained in the adjacent layer migrate to the surface layer, resulting in inhibition of curing, etc. This is not preferable, for example, because the electrical characteristics are degraded. Therefore, the photoreceptor surface temperature during UV irradiation is 100 ° C. or less, preferably 80 ° C. or less. As a cooling method, it is possible to use a cooling agent sealed inside the photoconductor, cooling with a gas or liquid inside the photoconductor, or the like.
You may post-heat with respect to the surface layer after hardening as needed. For example, in the case where a large amount of residual solvent remains in the film, it may cause a decrease in electrical characteristics or deterioration with time. Therefore, it is preferable to volatilize the residual solvent by post-heating.

  The film thickness of the surface layer is preferably 1 to 15 μm, more preferably 3 to 10 μm from the viewpoint of protecting the photosensitive layer. When the surface layer is thin, not only the photosensitive layer cannot be protected from mechanical abrasion due to the contact member to the photosensitive member or proximity discharge by a charger, etc., but also the film surface becomes difficult to level during film formation. It may be crumpled. On the other hand, when the surface layer is thick, the entire photoreceptor layer becomes thick, and the reproducibility of the image due to the diffusion of charges is not preferable.

<About adhesive layer>
For the purpose of preventing delamination due to poor adhesion between the surface layer / photosensitive layer, an adhesive layer may be provided between both layers as necessary.

  As the adhesive layer, the radical polymerizable monomer may be used, or a non-crosslinked polymer compound may be used. Non-crosslinked polymer compounds include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide, and polyvinyl benzal. , Polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, and the like, but are not limited thereto. In addition, the radical polymerizable monomer and the non-crosslinked polymer compound may be used either alone or as a mixture of two or more. Furthermore, a radically polymerizable monomer and a non-crosslinked polymer compound may be used in combination as long as sufficient adhesiveness is obtained. Of course, the charge transport material described in this specification may be used or may be used in combination. Moreover, if it aims at improving adhesiveness, you may use an additive suitably.

  The adhesive layer is formed by applying a coating solution prepared by dissolving or dispersing a compound formulated in a prescribed formulation in a solvent such as tetrahydrofuran, dioxane, dichloroethane, or cyclohexane by dip coating, spray coating, bead coating, or ring coating. it can. The thickness of the adhesive layer is suitably about 0.1 to 5 μm, preferably 0.1 to 3 μm is most suitable.

<About photosensitive layer>
Next, the photosensitive layer will be described. As described above, the photosensitive layer may have a function separation type laminated structure or a single layer structure. In the case of a laminated structure, the photosensitive layer is generally formed from a charge generation layer and a charge transport layer. In the case of a single layer structure, the photosensitive layer is a layer having a charge generation function and a charge transport function at the same time. Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.

<About the charge generation layer>
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.

  Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triarylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone. These binder resins can be used alone or as a mixture of two or more. The amount of the binder resin is preferably 0 to 500 parts by weight, more preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generation material. The binder resin may be added before or after dispersion.

Methods for forming the charge generation layer include a vacuum thin film preparation method and a casting method from a solution dispersion system. As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed. In addition, in order to provide the charge generation layer by the latter casting method, the inorganic or organic charge generation material described above together with a binder resin, if necessary, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. It can be formed by dispersing with a ball mill, attritor, sand mill, bead mill or the like using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc., and applying the solution after appropriately diluting the dispersion. Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The application can be performed by dip coating, spray coating, bead coating, ring coating, or the like.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

<About the charge transport layer>
The charge transport layer is a layer having a charge transport function, and is a layer mainly composed of a charge transport material and a binder resin.
Examples of the charge transport material include a hole transport material and an electron transport material.

  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 hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Other known materials may be used. These charge transport materials may be used alone or in combination of two or more.

  Binder resins 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-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins. In addition, as a binder resin, a polymeric charge transport material having a charge transport function, for example, polycarbonate, polyester, polyurethane, polyether, and polyamine having an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, a stilbene skeleton, a pyrazoline skeleton, or the like. Polymer materials such as siloxane and acrylic resins, polymer materials having a polysilane skeleton, and the like can be used and are useful.

The amount of the charge transport material is preferably 20 to 300 parts by weight, more preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it may be used alone or in combination with a binder resin.
As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used. These may be used alone or in combination of two or more.

If necessary, a plasticizer and a leveling agent can be added. As the plasticizer used for the charge transport layer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are. About 30 parts by weight is appropriate. Examples of leveling agents that can be used in the charge transport layer include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. About 0 to 1 part by weight is appropriate for the part by weight.
The thickness of the charge transport layer is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of resolution and responsiveness. Regarding the lower limit, although it differs depending on the system to be used (particularly, the charging potential), 5 μm or more is preferable.

<When the photosensitive layer is a single layer>
A photosensitive layer having a single layer structure is a layer having both a charge generation function and a charge transport function. The photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin in a suitable solvent, and applying and drying them. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. Of course, the polymer charge transport materials mentioned above can also be used favorably. The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. The photosensitive layer is formed by dip coating, spray coating, bead coating, ring coating with a charge generating material, a binder resin and a charge transport material dispersed in a disperser using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a coat.
The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

<About the undercoat layer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used.
The thickness of the undercoat layer is suitably from 0 to 5 μm.

<About other additives>
In the present invention, the surface layer, photosensitive layer, charge generation layer, charge transport layer, subbing layer, intermediate layer are used for the purpose of improving the environmental resistance, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential. An antioxidant can be added to each layer.
The following are mentioned as antioxidant which can be used for this invention.

<Phenolic compound>
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- [meth -3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) buty Rick acid] cricol ester, tocopherols and the like.

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

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

<Organic sulfur compounds>
Dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate and the like.
<Organic phosphorus compounds>
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
These compounds are known as antioxidants such as rubbers, plastics, oils and fats, and commercially available products can be easily obtained.
The addition amount of the antioxidant in the present invention is preferably 0.01 to 10 parts by weight with respect to the total weight of the layer to be added.

<About conductive support>
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. After metal oxide is deposited or sputtered, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. Pipes that have been subjected to surface treatment such as cutting, super-finishing, and polishing can be used. Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

  In addition, the conductive support dispersed in an appropriate binder resin on the support can be used as the conductive support of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Can be mentioned. The binder resin used at the same time includes 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-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine Examples thereof include thermoplastic resins such as resins, urethane resins, phenol resins, and alkyd resins, thermally crosslinkable resins, and photocrosslinkable resins. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Further, 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, polytetrafluoroethylene-based fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as the conductive support of the present invention.

<Protective substances>
A protective substance may be applied to the surface of the electrophotographic photosensitive member for the purpose of improving the cleaning property by reducing the surface energy of the electrophotographic photosensitive member and protecting it from electrical and mechanical hazards.
As the protective substance, various materials can be used as long as they can be uniformly applied to the surface of the electrophotographic photosensitive member, but materials such as wax, silicone oil, and fatty acid salts are effective. Fatty acid salts are particularly effective because they can be uniformly coated on the surface of the photoreceptor without causing deterioration of the electrical characteristics of the electrophotographic photoreceptor. Examples of fatty acids include undecyl acid, lauric acid, tridecyl acid, myristic acid, palmitic acid, pendadecyl acid, stearic acid, heptadecyl acid, arachidic acid, montanic acid, oleic acid, arachidonic acid, caprylic acid, capric acid, caproic acid, etc. Examples of the metal salt include salts with metals such as zinc, iron, copper, magnesium, aluminum, and calcium.

Furthermore, it is preferable to use a lamellar crystal powder such as zinc stearate as a protective substance. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and is slippery. This action is effective for lowering the coefficient of friction, but when viewed from the viewpoint of protecting the photoreceptor surface from electric discharge, the characteristics of lamellar crystals that uniformly cover the photoreceptor surface under shearing force are as follows: Since the surface of the photoreceptor can be effectively covered with a small amount of protective material, it is desirable as a protective material.
The method for applying the protective substance is not particularly limited, and examples thereof include a method in which a protective substance is applied in advance to a member such as a cleaning member that contacts the photosensitive member, and a method in which a dedicated application member is integrated with the process cartridge. . Providing a dedicated application member is preferable because a stable amount can be applied over a long period of time.

<< Configuration of image forming apparatus >>
Next, the image forming apparatus of the present invention will be described in detail with reference to the drawings.
The image forming apparatus of the present invention uses the electrophotographic photosensitive member having the crosslinked surface layer of the present invention. For example, at least after the photosensitive member is charged, exposed to an image, and developed, it is transferred to an image holding member (transfer paper). The toner image transfer means, and further, if necessary, means for fixing and cleaning the surface of the photoreceptor.
In some cases, an image forming apparatus that directly transfers an electrostatic latent image to a transfer body and develops the image forming apparatus does not necessarily include the above-described means disposed on the photoreceptor.

FIG. 4 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as a means for charging the photoconductor on average. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known method can be used.
Next, the image exposure unit (5) is used to form an electrostatic latent image on the uniformly charged photoreceptor (1). As this light source, all luminescent materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), and electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Next, the developing unit (6) is used to visualize the electrostatic latent image formed on the photoreceptor (1). Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (detection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained.

  Next, a transfer charger (10) is used to transfer the toner image visualized on the photoconductor onto the transfer body (9). In addition, a pre-transfer charger (7) may be used for better transfer. As these transfer means, a transfer charger, an electrostatic transfer method using a bias roller, a mechanical transfer method such as an adhesive transfer method and a pressure transfer method, and a magnetic transfer method can be used. As the electrostatic transfer method, the charging means can be used.

  Next, a separation charger (11) and a separation claw (12) are used as means for separating the transfer body (9) from the photoreceptor (1). As other separation means, electrostatic adsorption induction separation, side end belt separation, tip grip conveyance, curvature separation, and the like are used. As the separation charger (11), the charging means can be used.

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

The present invention also relates to an image forming method and an image forming apparatus process cartridge 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.

  In the image forming method using the apparatus illustrated in FIG. 5, 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. Parts and% are based on weight.

<Example 1>
<< Method for producing photoconductor >>
By coating and drying an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution in the following order on a φ30 mm aluminum cylinder in sequence, an undercoat layer of 3.5 μm A 0.2 μm charge generation layer and an 18 μm charge transport layer were formed.
[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 and Chemicals)
・ Titanium oxide 40 parts ・ Methyl ethyl ketone 50 parts

[Coating liquid for charge generation layer]
-Bisazo pigment of the following structural formula (1) 2.5 parts-Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 part-Cyclohexanone 200 parts-Methyl ethyl ketone 80 parts

[Coating liquid for charge transport layer]
・ 10 parts of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals)
・ Low molecular charge transport material of the following structural formula (2) 7 parts ・ Tetrahydrofuran 100 parts ・ 1% silicone oil tetrahydrofuran solution 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

Next, after applying a surface layer coating solution having the following composition onto the laminate comprising the conductive support / undercoat layer / charge generation layer / charge transport layer, using a metal halide lamp, illuminance: 500 mW / cm ² , Irradiation time: The surface layer was crosslinked by irradiating with light for 20 seconds to obtain a 5.2 μm hardened surface film. Thereafter, drying was performed at 130 ° C. for 30 minutes to obtain an electrophotographic photosensitive member comprising a conductive support / undercoat layer / charge generation layer / charge transport layer / surface layer.

[Coating liquid for surface layer]
-Radical polymerizable monomer having no charge transporting structure 95 parts Dipentaerythritol hexaacrylate of the following formula
(KAYARAD DPHA, Nippon Kayaku Co., Ltd.)

（ａ＝５，ｂ＝１の化合物とａ＝６、ｂ＝０の化合物の重量比１：１の混合物）
・１官能の電荷輸送性構造を有するラジカル重合性化合物 ９５部
（例示化合物 Ｎｏ．５４）
・一般式（２）または（３）で示される化合物 ６部
（例示化合物 Ｎｏ．２−１）
・光重合開始剤 １０部
１−ヒドロキシ−シクロヘキシル−フェニル−ケトン
（イルガキュアＩ−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 １２００部

(A mixture of a = 5, b = 1 and a = 6, b = 0 compound in a weight ratio of 1: 1)
-95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
-6 parts of compound shown by General formula (2) or (3) (Exemplary compound No.2-1)
Photopolymerization initiator 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone
(Irgacure I-184, Ciba Specialty Chemicals)
・ 1200 parts of tetrahydrofuran

<Example 2>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Example 1 was changed to the following.
95 parts of radically polymerizable monomer having no charge transporting structure caprolactone-modified dipentaerythritol hexaacrylate of the following formula
(KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)

<Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Example 1 was changed to the following.
-Radical polymerizable monomer having no charge transporting structure 95 parts Two mixed monomers using <1> and <2> below in a weight ratio of 1: 1 <1> Caprolactone-modified dipentaerythritol hexaacrylate of the following formula
KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)

〈２〉下記式のトリメチロールプロパントリアクリレート
（ＴＭＰＴＡ，東京化成社製）

<2> Trimethylolpropane triacrylate of the following formula
(TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)

<Example 4>
An electrophotographic photosensitive member was produced in the same manner as in Example 3 except that the compound represented by formula (2) or (3) used in the surface layer coating solution of Example 3 was changed to the following.
-6 parts of compound shown by general formula (2) or (3) (Exemplary Compound No. 3-1)

<Example 5>
An electrophotographic photosensitive member was produced in the same manner as in Example 3 except that the compound represented by formula (2) or (3) used in the surface layer coating solution of Example 3 was changed to the following.
Compound represented by general formula (2) or (3) Compound using <3> and <4> below in a weight ratio of 1: 1 6 parts <3> Illustrative compound 2-1
<4> Exemplary compounds 3-1.

<Example 6>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport layer coating solution and the surface layer coating solution in Example 1 were changed to the following.

[Coating liquid for charge transport layer]
・ 10 parts of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals)
-7 parts of the low molecular charge transport material of the structural formula (2)-0.2 parts of the compound represented by the general formula (2) or (3) (Exemplary Compound No. 2-1)
Tetrahydrofuran 100 parts 1% silicone oil tetrahydrofuran solution 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Coating liquid for surface layer]
・ Radical polymerizable monomer without charge transporting structure 95 parts Dipentaerythritol hexaacrylate
(KAYARAD DPHA, Nippon Kayaku Co., Ltd.)
-95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone
(Irgacure I-184, Ciba Specialty Chemicals)
・ 1200 parts of tetrahydrofuran

<Example 7>
An electrophotographic photoreceptor was produced in the same manner as in Example 6 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Example 6 was changed to the following.
95 parts of radically polymerizable monomer having no charge transporting structure caprolactone-modified dipentaerythritol hexaacrylate of the following formula
(KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)

<Example 8>
An electrophotographic photoreceptor was produced in the same manner as in Example 6 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Example 6 was changed to the following.
-Radical polymerizable monomer having no charge transporting structure 95 parts Two mixed monomers using <1> and <2> below in a weight ratio of 1: 1 <1> Caprolactone-modified dipentaerythritol hexaacrylate of the following formula
(KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)

〈２〉下記式のトリメチロールプロパントリアクリレート
（ＴＭＰＴＡ，東京化成社製）

<2> Trimethylolpropane triacrylate of the following formula
(TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)

<Example 9>
An electrophotographic photoreceptor was produced in the same manner as in Example 8, except that the compound represented by formula (2) or (3) used in the surface layer coating solution of Example 8 was changed to the following.
-6 parts of compound shown by general formula (2) or (3) (Exemplary Compound No. 3-1)

<Example 10>
An electrophotographic photoreceptor was produced in the same manner as in Example 8, except that the compound represented by formula (2) or (3) used in the surface layer coating solution of Example 8 was changed to the following.
Compound represented by general formula (2) or (3) Compound using <3> and <4> below in a weight ratio of 1: 1 6 parts <3> Illustrative compound 2-1
<4> Exemplary compounds 3-1.

<Example 11>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transport layer coating solution and the surface layer coating solution in Example 1 were changed to the following.

[Coating liquid for charge transport layer]
・ 10 parts of bisphenol Z polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals)
-7 parts of the low molecular charge transport material of the structural formula (2)-0.2 parts of the compound represented by the general formula (2) or (3) (Exemplary Compound No. 2-1)
Tetrahydrofuran 100 parts 1% silicone oil tetrahydrofuran solution 1 part (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Coating liquid for surface layer]
・ Radical polymerizable monomer without charge transporting structure 95 parts Dipentaerythritol hexaacrylate
(KAYARAD DPHA, Nippon Kayaku Co., Ltd.)
-95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
-0.2 part of compound shown by General formula (2) or (3) (Exemplary compound No.2-1)
Photopolymerization initiator 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure I-184, Ciba Specialty Chemicals)
・ 1200 parts of tetrahydrofuran

<Example 12>
An electrophotographic photoreceptor was produced in the same manner as in Example 11 except that the compound represented by formula (2) or (3) used in the surface layer coating solution of Example 11 was changed to the following.
-6 parts of compound shown by general formula (2) or (3) (Exemplary Compound No. 3-1)

<Example 13>
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 used in the surface layer coating solution of Example 1 was changed to the following.
95 parts of a radically polymerizable compound having a charge transporting structure of the following structural formula

<Example 14>
The photopolymerization initiator used in the surface layer coating solution of Example 3 was changed to the following thermal polymerization initiator, and the conductive support / undercoat obtained by applying the surface layer in the same manner as in Example 3 An electrophotographic photosensitive member was obtained by crosslinking the surface layer of the laminate comprising layer / charge generation layer / charge transport layer / surface layer by heating at 135 ° C. for 60 minutes.
Thermal polymerization initiator 10 parts by weight 1,1′-azobis (1-acetoxy-1-phenylethane)
(OT _AZO- 15, manufactured by Otsuka Chemical Co., Ltd.)

<Example 15>
By applying the surface layer in the same manner as in Example 3 using the surface layer coating liquid prepared without adding the photopolymerization initiator among the surface layer coating liquid composition used in Example 3. Irradiating an electron beam on the laminate comprising the obtained conductive support / undercoat layer / charge generation layer / charge transport layer / surface layer using an electron beam irradiation apparatus under conditions of an acceleration voltage of 150 keV and an irradiation amount of 5 Mrad. The surface layer was crosslinked with An electrophotographic photosensitive member was obtained by heating at 130 ° C. for 30 minutes after the electron beam irradiation.

<Comparative Example 1>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface layer coating solution in Example 1 was changed to the following.

[Coating liquid for surface layer]
・ Radical polymerizable monomer without charge transporting structure 95 parts Dipentaerythritol hexaacrylate
(KAYARAD DPHA, Nippon Kayaku Co., Ltd.)
-95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 10 parts 1-hydroxy-cyclohexyl-phenyl-ketone
(Irgacure I-184, Ciba Specialty Chemicals)
・ 1200 parts of tetrahydrofuran

<Comparative example 2>
An electrophotographic photoreceptor was prepared in the same manner as in Comparative Example 1 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Comparative Example 1 was changed to the following.
・ Radical polymerizable monomer without charge transporting structure 95 parts Caprolactone-modified dipentaerythritol hexaacrylate
(KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)

<Comparative Example 3>
An electrophotographic photoreceptor was prepared in the same manner as in Comparative Example 1 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Comparative Example 1 was changed to the following.
-Radical polymerizable monomer having no charge transporting structure 95 parts Two types of mixed monomers using <1> and <2> below in a weight ratio of 1: 1
<1> Caprolactone-modified dipentaerythritol hexaacrylate
(KAYARAD DPCA-120, manufactured by Nippon Kayaku Co., Ltd.)
<2> Trimethylolpropane triacrylate
(TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)

<Comparative example 4>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the surface layer coating solution in Comparative Example 1 was changed to the following.

[Coating liquid for surface layer]
-95 parts of radically polymerizable compound having a monofunctional charge transporting structure (Exemplary Compound No. 54)
-0.1 part of compound shown by General formula (2) or (3) (Exemplary compound No.2-1)
Photopolymerization initiator 5 parts 1-hydroxy-cyclohexyl-phenyl-ketone
(Irgacure I-184, Ciba Specialty Chemicals)
・ 600 parts of tetrahydrofuran

<Comparative Example 5>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the surface layer coating solution in Comparative Example 1 was changed to the following.

[Coating liquid for surface layer]
・ Radical polymerizable monomer without charge transporting structure 95 parts Dipentaerythritol hexaacrylate
(KAYARAD DPHA, Nippon Kayaku Co., Ltd.)
-0.1 part of compound shown by General formula (2) or (3) (Exemplary compound No.2-1)
Photopolymerization initiator 5 parts 1-hydroxy-cyclohexyl-phenyl-ketone
(Irgacure I-184, Ciba Specialty Chemicals)
・ 600 parts of tetrahydrofuran

<Comparative Example 6>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable monomer having no charge transporting structure used in the surface layer coating solution of Example 1 was changed to the following.

-Radical polymerizable monomer having no charge transporting structure 95 parts Bifunctional acrylate
(KAYARAD NPGDA, manufactured by Nippon Kayaku Co., Ltd.)

<Comparative Example 7>
Electrons were obtained in the same manner as in Example 1 except that the radical polymerizable compound having a charge transporting structure used in the surface layer coating solution of Example 1 was changed to a compound having a charge transporting structure of the following structural formula. A photographic photoreceptor was prepared.
・ 95 parts of a compound having a charge transporting structure

The following tests were carried out on the electrophotographic photoreceptors of Examples 1 to 15 and Comparative Examples 1 to 7 produced as described above.
<Surface roughness measurement>
For surface roughness measurement, Surfcom 1400D (manufactured by Tokyo Seimitsu) was used, and surface roughness Rz (10-point average roughness, JIS B0601-1982 standard) was measured against an evaluation length of 2.5 mm and a reference length of 0.5 mm. did. The measurement points were 80 mm from both ends of the drum in the axial direction, three points in the center of the drum, and four ways of 90 degrees in the circumferential direction. A total of 12 points were measured, and the average value was defined as the surface roughness Rz of the drum. Table 5 shows the results of measuring the surface roughness of the photoreceptor prepared by the method described above.

《Paper running with actual machine》
The paper running by the actual machine was tested by mounting the photosensitive member on an electrophotographic process cartridge and loading the process cartridge on a Ricoh-made Imagio MF2200 remodeling machine. In the image forming apparatus used here, a semiconductor laser having a wavelength of 655 nm was used as an image exposure light source, and a corona charging method (scorotron type) was used as a charging method. As a test method, a total of 100,000 sheets were continuously printed after setting the dark part potential to −800 V, and the initial image, 100,000 images, the light part potential, and the dark part potential were measured. In addition, the film thickness of the photoreceptor after initial printing of 50,000 sheets and 100,000 sheets was measured, and the amount of decrease from the initial film thickness was compared as the amount of wear. Table 6 shows the results of evaluating the photoconductor prepared by the above-described method by this test method.

《Oxidizing gas exposure test》
As a method for evaluating the oxidizing gas durability, the photoconductors shown in Examples 1 to 15 and Comparative Examples 1 to 7 were separately prepared, and adjusted in an atmosphere having a NO gas concentration of 50 ppm and a NO ₂ gas concentration of 15 ppm. The gas exposure was carried out by leaving still for 4 days. After the gas exposure, a halftone with an image density of 50% was output using the above-described image forming apparatus, and the change in the image density before and after the gas exposure was confirmed. Table 7 shows the results of evaluation of the photoconductors of Examples 1 to 4, 6 to 9, 11, 14 to 15 and Comparative Examples 1 to 3 by this test method.

From the results of Table 5, the photoreceptors of Examples 1 to 12 and 14 to 15 all had good smoothness. In particular, in Examples 3 to 5 and 8 to 10 in which a trifunctional acrylic monomer was used in combination, a photoreceptor excellent in surface property could be obtained. Further, although the surface property of the photoconductor of Example 13 was slightly inferior, there was no problem in use.
On the other hand, Comparative Examples 1-3 and 5-6 all had good smoothness. The photoconductor of Comparative Example 4 was not successfully cross-linked and as a result could not be used for testing. Further, the photoreceptor of Comparative Example 7 had poor surface properties, and defects could be easily confirmed visually.

  As is apparent from the results in Table 6, in the photoconductors of Examples 1 to 13 and 15, no significant fluctuation was observed in the in-machine potential from the start of actual machine run to the end of 100,000 sheets, and the amount of wear was extremely high. Less was shown. In Example 14, there was a tendency that the exposed portion potential and the wear amount slightly increased. Although the cause is not clear, it is considered to be an influence of the polymerization initiator used in this example, but sufficient wear resistance was shown, and the potential fluctuation was within the use range. Similarly, the photoreceptors of Comparative Examples 1 to 3 show that the in-machine potential fluctuation is small and the amount of wear is extremely small. On the other hand, the photoconductor of Comparative Example 5 was not suitable for actual use because the bright part potential was high and the image density was low from the beginning of running. Further, the photoconductors of Comparative Examples 6 to 7 had a large amount of wear, and it was difficult to say that they were highly durable photoconductors.

  As is clear from the results of Table 7, changes in image density due to gas exposure were confirmed for the photoreceptors of Comparative Examples 1 to 3 that did not contain the compounds described in the general formulas (2) and (3) in the layer. On the other hand, for the photoreceptor containing the compounds described in the general formulas (2) and (3) in the layer, there was almost no change in image density before and after gas exposure.

It is sectional drawing which shows an example in case the photosensitive layer of the electrophotographic photoreceptor in this invention is a single layer. It is sectional drawing which shows the example in case the photosensitive layer of the electrophotographic photoreceptor in this invention is laminated | stacked. It is sectional drawing which shows another example in case the photosensitive layer of the electrophotographic photoreceptor in this invention is laminated | stacked. 1 is a schematic diagram illustrating an example of an image forming apparatus according to the present invention. It is a figure which shows an example of the process cartridge in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 4 Eraser 5 Image exposure part 6 Development 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 101 Photoconductor DESCRIPTION OF SYMBOLS 102 Charging means 103 Exposure means 104 Developing means 105 Transfer body 106 Transfer means 107 Cleaning means

Claims (16)

In an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer in this order on a conductive support, the surface layer has at least a radical polymerizable monomer having no charge transporting structure represented by the following general formula (1); A radically polymerizable compound having a transportable structure is formed by curing using at least one of heat, light, and ionizing radiation, and the following general components are included in the photosensitive layer and / or the surface layer. An electrophotographic photoreceptor comprising at least one selected from compounds represented by formula (2).

(Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ are hydrogen or

R ₁₇ represents a single bond, an alkylene group, an alkylene ether group, a polyoxyalkylene group, a hydroxyl group-substituted alkylene ether group, a (meth) acryloyloxy group-substituted alkylene ether group, an oxyalkylene carbonyl group, a poly (oxyalkylene carbonyl group) ) Group, and R ₁₈ represents hydrogen or a methyl group. However, four or more of R _{11 to} R ₁₆ are not hydrogen at the same time. )

(In the formula, R ₂ and R ₃ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₂ and R ₃ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aromatic ring group, and l and m each represents an integer of 0 to 3, provided that l and m Are not simultaneously 0. n represents an integer of 1 to 3.) In an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer in this order on a conductive support, the surface layer has at least a radical polymerizable monomer having no charge transporting structure represented by the following general formula (1); A radically polymerizable compound having a transportable structure is formed by curing using at least one of heat, light, and ionizing radiation, and the following general components are included in the photosensitive layer and / or the surface layer. An electrophotographic photoreceptor comprising at least one selected from compounds represented by formula (3).

(Wherein R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ are hydrogen or

R ₁₇ represents a single bond, an alkylene group, an alkylene ether group, a polyoxyalkylene group, a hydroxyl group-substituted alkylene ether group, a (meth) acryloyloxy group-substituted alkylene ether group, an oxyalkylene carbonyl group, a poly (oxyalkylene carbonyl group) ) Group, and R ₁₈ represents hydrogen or a methyl group. However, four or more of R _{11 to} R ₁₆ are not hydrogen at the same time. )

(Wherein R ₄ and R ₅ represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted alkyl group, and may be the same or different. R ₄ and R ₅ are bonded to each other. And a heterocyclic group containing a nitrogen atom may be formed, Ar ₃ and Ar ₄ each represent a substituted or unsubstituted aromatic ring group, and l ′ and m ′ each represent an integer of 0 to 3, provided that l 'And m' are not 0 at the same time. N 'represents an integer of 1 to 3.)   3. The electrophotographic image according to claim 2, wherein the photosensitive layer and / or the surface layer further contains at least one selected from the compounds represented by the general formula (2) according to claim 1. Photoconductor.   The radical polymerizable monomer having no charge transporting structure used for the surface layer is a mixture of a radical polymerizable monomer represented by the general formula (1) and a tri- or higher functional radical polymerizable monomer. The electrophotographic photosensitive member according to any one of claims 1 to 3.   5. The electrophotography according to claim 1, wherein the functional group of the radical polymerizable compound having a charge transporting structure used for the surface layer is an acryloyloxy group and / or a methacryloyloxy group. Photoconductor.   6. The electrophotographic photoreceptor according to claim 1, wherein the charge transport structure of the radical polymerizable compound having a charge transport structure used for the surface layer is a triarylamine structure.   The electrophotographic photosensitive member according to claim 1, wherein the radical polymerizable compound having a charge transporting structure used for the surface layer has one functional group. The radically polymerizable compound having a monofunctional charge transporting structure used for the surface layer is one or more of the compounds represented by the following general formula (4) or (5). Electrophotographic photoreceptor.

[Wherein R ₆ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, A group, an alkoxy group, —COOR ₇ (R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. ), A halogenated carbonyl group or CONR ₈ R ₉ (R ₈ and R ₉ have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents an aryl group which may be the same or different from each other. Ar ₅ and Ar ₆ represent a substituted or unsubstituted arylene group and may be the same or different. . Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether group, or an alkyleneoxycarbonyl group. j and k each represents an integer of 0 to 3. ] 8. The electrophotographic photosensitive member according to claim 7, wherein the radical polymerizable compound having a monofunctional charge transporting structure used in the surface layer is one or more of compounds represented by the following general formula (6). body.

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

Represents. )   The electrophotographic photoreceptor according to claim 1, wherein the surface layer curing means is heating or light energy irradiation means.   The electrophotographic photosensitive member according to claim 10, wherein the surface layer curing means is light energy irradiation means.   The electrophotographic photosensitive member according to claim 1, wherein the surface layer has a thickness of 1 to 15 μm.   13. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a structure in which at least a charge generation layer and a charge transport layer are laminated.   A charging process for charging at least the electrophotographic photosensitive member using the electrophotographic photosensitive member according to any one of claims 1 to 13, and forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charging process. A latent image forming process, a developing process for attaching toner to the electrostatic latent image formed by the latent image forming process, and a transfer process for transferring the toner image formed by the developing process to the transfer target are repeated. An image forming method.   14. The electrophotographic photosensitive member according to claim 1, a charger for charging the electrophotographic photosensitive member, and a latent image for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger. An image forming apparatus comprising: a forming unit; a developing unit that attaches toner to an electrostatic latent image formed by the latent image forming unit; and a transfer unit that transfers a toner image formed by the developing unit to a transfer target. 14. The electrophotographic photosensitive member according to claim 1, a charger for charging at least the electrophotographic photosensitive member, and a latent image for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger. An image forming unit; a developing unit that attaches toner to the electrostatic latent image formed by the latent image forming unit; a transfer unit that transfers the toner image formed by the developing unit to a transfer target; and an electrophotographic photosensitive member after transfer An image forming apparatus comprising one means selected from the group consisting of a cleaning device for removing toner remaining on the surface of the body from the surface of the electrophotographic photosensitive member, wherein the image forming apparatus body is removable. Process cartridge for equipment.

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