JP2005345593A - Electrophotographic photoreceptor, and image forming apparatus and process cartridge using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor, having improved wear and scuffing resistances by increased film strength and also having proper deposition resistance. <P>SOLUTION: A surface layer of the photoreceptor comprises a compound prepared by curing a mixture, by polymerization or crosslinking under radiation irradiation, including at least a hole transport compound, having a chain-polymerizable functional group and a polymer or oligomer which is soluble by ≥1 wt.% in a compound prepared by hydrogenating a terminal of the chain-polymerizable functional group, and the reaction of which under radiation irradiation is a main chain breaking type one, whose G value is ≥0.5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and a method for producing the electrophotographic photosensitive member, and more specifically, an electrophotographic photosensitive member having a photosensitive layer containing a specific compound. The present invention relates to a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and a method for manufacturing the electrophotographic photosensitive member.

  Conventionally, inorganic materials such as selenium, cadmium sulfide and zinc oxide have been known as photoconductive materials used for electrophotographic photoreceptors. On the other hand, polyvinylcarbazole, phthalocyanine, and azo pigments, which are organic materials, are attracting attention for advantages such as high productivity and non-pollution, and tend to be inferior in terms of photoconductive properties and durability compared to inorganic materials. , Has come to be widely used.

  These electrophotographic photoreceptors are often used as function-separated photoreceptors in which a charge generation layer and a charge transport layer are laminated in order to satisfy both electrical and mechanical properties. On the other hand, as a matter of course, the electrophotographic photosensitive member is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. In particular, since various electrical and mechanical external forces such as charging, image exposure, toner development, transfer to paper, and cleaning are directly applied to the surface of the photoreceptor to be used repeatedly, durability against them is required.

  Specifically, durability against the occurrence of surface wear and scratches due to rubbing, surface deterioration due to charging, for example, transfer efficiency and slipperiness decrease, and durability against deterioration of electrical characteristics such as sensitivity reduction and potential decrease. Required.

  In general, the surface layer of an electrophotographic photoreceptor using an organic photoconductive material is a thin resin layer, and the characteristics of the resin are very important. In recent years, acrylic resins and polycarbonate resins have been put to practical use as resins that satisfy the above-mentioned various conditions. However, not all of the above-mentioned characteristics are satisfied with these resins, and it is difficult to say that the hardness of the resin is sufficiently high particularly for further enhancement of durability. Even when these resins are used as the resin for the surface layer, the surface layer may be worn or scratched with repeated use.

  In addition, due to the recent demand for higher sensitivity, low molecular weight compounds such as charge transport materials are often added in relatively large amounts. In this case, the film strength is significantly reduced due to the plasticizer action of these low molecular weight materials. Therefore, wear and scratches on the surface layer during repeated use have become a more prominent problem. In addition, a problem that the low molecular weight compound precipitates during storage of the electrophotographic photosensitive member is likely to occur.

  As means for solving these problems, the use of a curable resin as a resin for a charge transport layer is disclosed in, for example, JP-A-2-127852 (Patent Document 1). In this case, a curable resin is used as the resin for the charge transport layer, and the charge transport layer is cured and crosslinked to greatly improve the abrasion resistance and scratch resistance during repeated use.

  However, even when a curable resin is used, since the low molecular weight compound acts as a plasticizer in the binder resin, the problem of precipitation as described above has not been fundamentally solved. In the charge transport layer composed of the organic charge transport material and the binder resin, the charge transport ability largely depends on the resin. For example, in a curable resin having a sufficiently high hardness, the charge transport ability tends to be low. Both the hardness and the electrophotographic characteristics have not been fully satisfied, for example, the residual potential tends to increase during repeated use.

  In JP-A-5-216249 (Patent Document 2) and JP-A-7-72640 (Patent Document 3), a charge transport layer contains a monomer having a carbon-carbon double bond, and charge transport is performed. An electrophotographic photoreceptor is disclosed in which a carbon-carbon double bond of a substance is reacted by heat or light energy to form a charge transport layer. However, the charge transport material is only immobilized in a pendant form on the main skeleton of the polymer, and the mechanical strength is not sufficient because the above plastic action cannot be sufficiently eliminated. Further, if the concentration of the charge transport material is increased to improve the charge transport capability, the crosslink density is lowered and sufficient mechanical strength cannot be ensured. Furthermore, there is a concern about the influence of the initiators required during polymerization on the electrophotographic characteristics.

  As another solution, for example, in JP-A-8-248649 (Patent Document 4), an electron having a charge transport layer containing a thermoplastic polymer into which a group having charge transport ability is introduced in the main chain. A photographic photoreceptor is disclosed, which is more effective for precipitation than a conventional molecular dispersion type charge transport layer and improves mechanical strength, but it is only a thermoplastic resin and its mechanical strength. Is limited, and it is difficult to say that it is sufficient in terms of handling and productivity including resin solubility.

As described above, it has been studied to achieve both mechanical strength and charge transport capability at a higher level.
JP-A-2-127852 JP-A-5-216249 Japanese Patent Laid-Open No. 7-72640 JP-A-8-248649

  The object of the present invention is to solve the problems of the conventional electrophotographic photosensitive member, to improve the abrasion resistance and scratch resistance by increasing the film strength, and to have good precipitation resistance. To provide a body.

  Another object of the present invention is to provide an electrophotographic photoreceptor capable of exhibiting stable performance even during repeated use, with very little change or deterioration in photoreceptor properties such as increase in residual potential during repeated use. There is.

  Still another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

  Still another object of the present invention is to provide a method for producing the electrophotographic photosensitive member.

  That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the surface layer of the photoreceptor has at least a hole-transporting compound having a chain-polymerizable functional group, and the chain-polymerizable functional group. 1% by weight or more is soluble in the compound hydrogenated at the end, and the reaction by irradiation is a main chain cleavage type and the G value is 0.5 or more, or the reaction by irradiation is a crosslinking type and the G value is An electrophotographic photoreceptor comprising a compound cured by polymerizing or crosslinking a mixture containing a polymer or oligomer of 1.0 or more by irradiation.

  The present invention also provides a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

  Furthermore, the present invention provides a method for producing an electrophotographic photoreceptor in which a photosensitive layer is formed on a support, wherein a hole transporting compound having a chain polymerizable functional group and a terminal of the chain polymerizable functional group are hydrogenated. The compound is soluble in the compound by 1% by weight or more and the reaction by irradiation is a main chain cleavage type and the G value is 0.5 or more, or the reaction by irradiation is a crosslinking type and the G value is 1.0 or more. An electrophotographic photosensitive member production method comprising a step of curing a polymer or oligomer-containing mixture by polymerization or crosslinking by irradiation with radiation.

  As described above, the electrophotographic photosensitive member of the present invention has an effect excellent in precipitation resistance, abrasion resistance and scratch resistance. Furthermore, electrophotographic characteristics such as sensitivity and residual potential are very good, and stable performance can be exhibited even during repeated use.

  In addition, the effect of the electrophotographic photosensitive member is naturally exhibited in a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and high image quality is maintained for a long time.

  Details of the present invention will be described below.

  The chain polymerization in the present invention refers to the former polymerization reaction form when the polymer formation reaction is largely divided into chain polymerization and sequential polymerization. For details, see, for example, “Basic Chemistry Resin Chemistry” by Giho Tadahiro Miho. (New Edition) ”July 25, 1995 (1 edition, 8 prints) As described in FIG. 24, the form mainly refers to unsaturated polymerization, ring-opening polymerization, isomerization polymerization, etc. in which the reaction proceeds via an intermediate such as a radical or ion.

  The chain polymerizable functional group means a functional group capable of the above-described reaction form, and here, a specific example of an unsaturated polymerization or ring-opening polymerizable functional group that occupies most of the functional group and has a wide application range will be shown.

  Unsaturated polymerization is a reaction in which unsaturated groups such as C═C, C≡C, C═O, C═N, and C≡N are polymerized by radicals and ions. It is. Specific examples of the unsaturated polymerizable functional group are shown below, but are not limited thereto.

上記中、Ｒは置換基を有してもよいメチル基、エチル基及びプロピル基等のアルキル基、置換基を有してもよいベンジル基及びフェネチル基等のアラルキル基及び置換基を有してもよいフェニル基、ナフチル基及びアンスリル基等のアリール基または水素原子等を示す。

In the above, R has an alkyl group such as a methyl group, an ethyl group and a propyl group which may have a substituent, an aralkyl group such as a benzyl group and a phenethyl group which may have a substituent, and a substituent. An aryl group such as a phenyl group, a naphthyl group and an anthryl group, or a hydrogen atom may be used.

  Ring-opening polymerization is an unstable cyclic structure with distortions such as carbocycles, oxo rings and nitrogen heterocycles activated by the action of a catalyst, and at the same time, the polymerization is repeated to produce a chain polymer. In this case, most of the reactions basically have ions acting as active species. Specific examples of the ring-opening polymerization functional group are shown below, but are not limited thereto.

上記中、Ｒ′は置換基を有してもよいメチル基、エチル基及びプロピル基等のアルキル基、置換基を有してもよいベンジル基及びフェネチル基等のアラルキル基及び置換基を有してもよいフェニル基、ナフチル基及びアンスリル基等のアリール基または水素原子等を示す。

In the above, R ′ has an alkyl group such as a methyl group, an ethyl group and a propyl group which may have a substituent, an aralkyl group such as a benzyl group and a phenethyl group which may have a substituent, and a substituent. An aryl group such as a phenyl group, a naphthyl group, and an anthryl group, a hydrogen atom, or the like may be used.

  Among the chain polymerizable functional groups according to the present invention as described above, those represented by the following general formula (1) are preferable.

式中、Ｅは水素原子、フッ素、塩素及び臭素等のハロゲン原子、置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有してもよいフェニル基、ナフチル基、アンスリル基、ピレニル基、チオフェニル基及びフリル基等のアリール基、ＣＮ基、ニトロ基、メトキシ基、エトキシ基及びプロポキシ基等のアルコキシ基、−ＣＯＯＲ⁷及びＣＯＮＲ⁸Ｒ⁹を示す。

In the formula, E may have a hydrogen atom, a halogen atom such as fluorine, chlorine and bromine, an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, or a substituent. Aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group, optionally substituted phenyl group, naphthyl group, anthryl group, pyrenyl group, thiophenyl group and furyl group, aryl groups such as An alkoxy group such as CN group, nitro group, methoxy group, ethoxy group and propoxy group, -COOR ⁷ and CONR ⁸ R ⁹ are shown.

W is an arylene group such as divalent phenylene, naphthylene and anthracenylene which may have a substituent, a divalent alkylene group such as methylene, ethylene and butylene which may have a substituent, -COO-, -CH _2- , -O-, -OO-, -S- or CONR ^10- .

R ⁷ , R ⁸ , R ⁹ and R ¹⁰ have a hydrogen atom, a halogen atom such as fluorine, chlorine and bromine, an optionally substituted alkyl group such as a methyl group, an ethyl group and a propyl group, and a substituent. An aralkyl group such as a benzyl group and a phenethyl group, and an aryl group such as a phenyl group, a naphthyl group and an anthryl group which may have a substituent, and R ⁸ and R ⁹ may be the same or different from each other; May be.

  F represents 0 or 1.

  Examples of the substituent that E and W may have include halogen atoms such as fluorine, chlorine, bromine and iodine, alkyl groups such as nitro group, cyano group, hydroxyl group, methyl group, ethyl group, propyl group and butyl group, Alkoxy groups such as methoxy group, ethoxy group and propoxy group, aryloxy groups such as phenoxy group and naphthoxy group, aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group, phenyl group, naphthyl group, Examples include aryl groups such as anthryl group and pyrenyl group.

  Among the general formula (1), more particularly preferable chain polymerizable functional groups include those represented by the following general formulas (2) to (6).

本発明で用いる連鎖重合性官能基を有する正孔輸送性化合物は分子内に正孔輸送性基を有する。正孔輸送性基は正孔輸送性を示すものであればいずれのものでもよく、連鎖重合性官能基を水素原子に置き換えた水素付加化合物（正孔輸送性化合物）として示せば、例えばオキサゾール誘導体、オキサジアゾール誘導体、イミダゾール誘導体、トリフェニルアミン等のトリアリールアミン誘導体、９−（ｐ−ジエチルアミノスチリル）アントラセン、１，１−ビス−（４−ジベンジルアミノフェニル）プロパン、スチリルアントラセン、スチリルピラゾリン、フェニルヒドラゾン類、チアゾール誘導体、トリアゾール誘導体、フェナジン誘導体、アクリジン誘導体、ベンゾフラン誘導体、ベンズイミダゾール誘導体、チオフェン誘導体及びＮ−フェニルカルバゾール誘導体等が挙げられる。

The hole transporting compound having a chain polymerizable functional group used in the present invention has a hole transporting group in the molecule. The hole transporting group may be any group as long as it exhibits hole transporting properties. For example, an oxazole derivative may be used as a hydrogenation compound (hole transporting compound) in which a chain polymerizable functional group is replaced with a hydrogen atom. , Oxadiazole derivatives, imidazole derivatives, triarylamine derivatives such as triphenylamine, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyra Examples include zoline, phenylhydrazones, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and N-phenylcarbazole derivatives.

  Preferable examples of the hole transporting compound having a chain polymerizable functional group are disclosed in the applications by the present inventors (JP 2000-066425, JP 2000-206715, JP 2000-206716). It is not limited to.

  The surface layer of the electrophotographic photoreceptor of the present invention is soluble in the compound having the chain polymerizable functional group hydrogenated at least 1% by weight together with the hole transport compound having the chain polymerizable functional group and is irradiated with radiation. A mixture containing a polymer or an oligomer having a G chain value of 0.5 or more, or a reaction by crosslinking, and a G or G value of 1.0 or more. Contains compounds cured by polymerization or crosslinking.

  The effect of mixing the polymer or oligomer with a hole transport compound having a chain polymerizable functional group is to increase the starting point of a polymerization reaction generated by radiation irradiation, that is, the generation efficiency of radicals and ions. This makes it possible to achieve a high degree of polymerization with a small amount of radiation, and as a result, it is possible to simultaneously increase productivity and durability.

  When a hole transport compound having a chain polymerizable functional group is polymerized by irradiation, the degree of polymerization can be increased by increasing the radiation dose, but if the radiation dose is excessively increased at this time, There is also a tendency that adverse effects occur in the sensitivity characteristics of the electrophotographic photosensitive member and the stability of the potential during continuous use. Therefore, in the present invention, the above polymer or oligomer is mixed with a hole transport compound having a chain polymerizable functional group to enable curing with a small amount of radiation, thereby preventing the occurrence of the above adverse effects.

  In order to effectively increase the degree of polymerization by mixing with a hole transport compound having a chain polymerizable functional group, the material must be compatible with the hole transport compound having a chain polymerizable functional group. The material must have high radical and ion generation efficiency upon irradiation, which acts as a starting point for the polymerization reaction, and polymers and oligomers with repeating units in the molecule were more effective than low molecular weight materials. .

  As a measure of compatibility with a hole transport compound having a chain polymerizable functional group, as a result of the study by the present inventors, the solubility in a compound in which the terminal of the chain polymerizable functional group is hydrogenated is 1% by weight or more. It was necessary to be. Here, the compound in which the terminal of the chain polymerizable functional group is hydrogenated is, for example, acrylic acid if the polymerizable functional group of the hole transporting compound is an acrylic group represented by the general formula (2). If it is a styrene group shown by Formula (6), it is a styrene monomer. It is a polymer or oligomer that can be mixed with a polymer or oligomer that dissolves 1% by weight or more with respect to these acrylic acid or styrene monomer and further exhibits a predetermined G value as described below.

  In addition, when the hole transport compound having a chain polymerizable functional group has a plurality of different chain polymerizations in the molecule, or when a plurality of different hole compounds are used, the determination of the solubility is most often included in the mixture. The functional group to be selected can be selected, and this can be judged by the solubility in the compound in which the terminal is hydrogenated.

  Therefore, the polymer or oligomer that can be used in the present invention differs depending on the hole transport compound having a chain polymerizable functional group, and it is necessary to select an appropriate combination. Furthermore, since the solubility of the polymer or oligomer depends on the molecular weight, it is necessary to select the molecular weight. The solubility was confirmed at 23 ° C., and whether or not dissolution was possible was judged visually. Here, the G value represents the efficiency of the reaction caused by radiation. The G value is defined by the number of chemical species that are lost or produced by the reaction per 100 eV of radiation energy absorbed by the system. In particular, when a polymer compound is irradiated with radiation, a reaction such as cutting of the polymer main chain or crosslinking between polymer compounds occurs. Whether the production efficiency and main chain cleavage or cross-linking is prioritized depends on the conditions such as the atmosphere, temperature, solid or liquid, but in the irradiation in the solid state in an inert gas atmosphere or vacuum, The reaction is determined by the chemical structure of the polymer compound, and the reaction efficiency of the main chain cleavage and crosslinking reaction at this time is defined as the G value of the main chain cleavage and crosslinking reaction. The polymer or oligomer is divided into a main chain cleavage type and a cross-linking type depending on which of the two reactions at the time of irradiation is superior. In the present invention, the G value for effective operation of the polymer or oligomer is determined by irradiation. The G value in the main chain cleavage type by 0.5 was 0.5 or more, and the G value in the crosslinking reaction by radiation irradiation in the crosslinking type was 1.0 or more.

  Among cross-linked polymers or oligomers, compounds having an unsaturated carbon-carbon double bond in the repeating unit of the chemical structure have a very large effect of promoting curing when irradiated with a low dose of radiation, and the effect is butadiene-based. It was even more pronounced with polymers or oligomers and isoprene-based oligomers or oligomers.

  Of the main chain cleavage type polymers or oligomers, polyisobutylene is particularly effective for improving curability when irradiated with a low radiation dose, and also has good photoreceptor characteristics such as sensitivity and residual potential.

Table 1 shows examples of reaction superiority type and G value in each polymer.
Among the polymers or oligomers shown in Table 1, those having a G value equal to or higher than a specified value can be used in the present invention, but are not limited to the examples in Table 2, and are compatible with the polymerizable functional group and predetermined. Any G value can be used.

本発明においては、連鎖重合性基を有する正孔輸送性化合物の重合／架橋を放射線により行う。

In the present invention, polymerization / crosslinking of the hole transporting compound having a chain polymerizable group is carried out by radiation.

  The greatest advantage of polymerization by radiation is that a polymerization initiator is not required, which makes it possible to produce a very high-purity polymer and to ensure good electrophotographic characteristics. In addition, the productivity is high because it is a short and efficient polymerization reaction. Furthermore, since radiation is excellent in permeability, it can be mentioned that a blocking substance such as an additive is present in the layer or the influence of curing inhibition when forming a thick layer is very small.

  However, depending on the type of the chain polymerizable group and the type of the central skeleton, the polymerization reaction may not easily proceed, and in that case, it is possible to add a polymerization initiator within a range that does not affect.

  Examples of the radiation to be used include an electron beam and γ-ray, and an electron beam is preferable in terms of efficiency. In the case of electron beam irradiation, any type of accelerator such as a scanning type, an electro curtain type, a broad beam type, a pulse type, and a laminar type can be used. Moreover, when irradiating an electron beam, in this invention, irradiation conditions are very important in order to express an electrical property and durability performance. The acceleration voltage is preferably 300 KV or less, and optimally 150 KV or less. The dose is preferably in the range of 0.1 Mrad to 30 Mrad, more preferably in the range of 0.5 Mrad to 20 Mrad. When the acceleration voltage exceeds 300 KV, the damage of the electron beam irradiation on the characteristics of the photoreceptor tends to increase. Further, when the dose is less than 0.1 Mrad, the crosslinking is likely to be insufficient, and when it exceeds 30 Mrad, the influence of radiation irradiation may be observed on the sensitivity characteristics of the photoconductor and the potential fluctuation during repeated use.

  In the present invention, the main chain cleavage type reaction is soluble in a hole transporting compound having a chain polymerizable functional group and a compound in which the terminal of the chain polymerizable functional group is hydrogenated by 1% by weight or more, and the reaction by radiation irradiation. By polymerizing and cross-linking a mixture containing a polymer or oligomer having a G value of 0.5 or more or a reaction by radiation irradiation and a G value of 1.0 or more by radiation irradiation, In the surface layer of the photoreceptor, a compound having a hole transporting ability is incorporated into the photosensitive layer through a covalent bond with a crosslinking point. The hole transporting compound can be polymerized, crosslinked, or mixed with a compound having another chain polymerizable group, and the kind / ratio thereof is arbitrary. As used herein, the compound having another chain polymerizable group includes any of a monomer, an oligomer and a polymer having a chain polymerizable group.

  When the functional group of the hole transporting compound and the functional group of the other chain polymerizable compound are the same group or a group that can be polymerized with each other, both have a copolymerized three-dimensional crosslinked structure via a covalent bond. It is possible. When both functional groups are functional groups that do not polymerize with each other, the photosensitive layer is a mixture of at least two or more three-dimensional cured products or other chain polymerizable compound monomers in the main component three-dimensional cured product, Or it is comprised as what contains the hardened | cured material, However, IPN (Inter Penetrating Network), ie, an interpenetrating network structure, can also be formed by controlling the compounding ratio / film forming method well.

  Further, a photosensitive layer may be formed from the above-described hole transporting compound and a monomer, oligomer and polymer having no chain polymerizable group, or a monomer, oligomer or polymer having a polymerizable group other than the chain polymerizable group. Good. Furthermore, in some cases, it is also possible to contain a hole transporting compound that is not chemically bonded to the three-dimensional crosslinked structure, that is, does not have a chain polymerizable functional group. Moreover, you may contain other various additives, for example, lubricants, such as fluorine atom containing resin fine particles.

  The photoreceptor of the present invention has a structure in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order on the support as a photosensitive layer, or vice versa. It is possible to take any configuration of a single layer in which a substance and a charge transporting substance are dispersed in the same layer. In the former stacked type, the charge transport layer may be composed of two or more layers. In the latter single layer type, a charge transport layer may be further formed on the photosensitive layer containing the same charge generating material and charge transport material. Furthermore, a protective layer can be formed on the charge generation layer or the charge transport layer.

  In any of these cases, the surface layer of the photoreceptor contains a polymer obtained by polymerizing and crosslinking a mixture containing the hole transport compound having the chain polymerizable functional group and the specific polymer or oligomer by irradiation. It only has to be. However, from the viewpoint of characteristics as an electrophotographic photoreceptor, particularly electrical characteristics such as residual potential and durability, a function-separated photoreceptor structure in which a charge generation layer and a charge transport layer are laminated in this order is preferable, and the advantages of the present invention However, the surface layer can be made highly durable without deteriorating the charge transport ability.

  The support that the electrophotographic photosensitive member has is only required to have conductivity. For example, a metal or alloy such as aluminum, copper, chromium, nickel, zinc and stainless steel formed into a drum shape or a sheet shape, a metal stay such as aluminum and copper laminated on a plastic film, aluminum, indium oxide and tin oxide Or the like deposited on a plastic film, a metal provided with a conductive layer by applying a conductive substance alone or with a binder resin, a plastic film, and paper.

  In the present invention, an undercoat layer having a barrier function and an adhesive function can be provided between the support and the photosensitive layer. The undercoat layer is used to improve the adhesion of the photosensitive layer, improve coating properties, protect the support, cover defects on the support, improve charge injection from the support, and protect against electrical breakdown of the photosensitive layer. It is formed.

  Materials for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue and gelatin Etc. The undercoat layer is formed by applying a solution prepared by dissolving these materials in a solvent suitable for each of the materials onto a support and drying it. The film thickness is preferably 0.1 to 2 μm.

  As described above, the laminated photosensitive layer has a charge generation layer and a charge transport layer.

  Examples of charge generation materials include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals and crystal systems, specifically, phthalocyanine compounds having crystal types such as α, β, γ, ε, and X type, Anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, quinocyanine, and amorphous silicon described in JP-A No. 54-143645 It is done.

  The charge generation layer is obtained by dispersing the charge generation material together with 0.3 to 4 times the amount of binder resin and solvent by a method such as homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, adrider and roll mill. The resulting dispersion is applied and dried, or is formed as a single composition film such as a vapor-deposited film of the charge generation material. The film thickness is preferably 5 μm or less, and particularly preferably 0.1 to 2 μm.

  As binder resin, polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, polyvinyl acetal, polycarbonate, polyester , Polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin and epoxy resin.

  In the present invention, the hole transporting compound having a chain polymerizable functional group formed a charge transport layer on the charge generation layer described above or a charge transport layer made of a charge transport material and a binder resin on the charge generation layer. It can be used later as a surface protective layer having a hole transport capability. Since this surface protective layer has a hole transport capability, it is included within the definition of the photosensitive layer.

  In any case, together with the hole transporting compound having the chain polymerizable functional group, the chain polymerizable functional group is soluble in a compound hydrogenated at 1% by weight or more, and the reaction by radiation irradiation is a main chain cleavage type. And after applying a solution containing a polymer or oligomer having a G value of 0.5 or more or a reaction by radiation irradiation and a G value of 1.0 or more, a polymerization / crosslinking reaction is performed. Although it is preferable, a surface layer can be formed using a material obtained by reacting a solution containing a hole transporting compound in advance to obtain a cured product and then dispersing or dissolving it again in a solvent.

  When a hole transporting compound having a chain polymerizable group is used as the charge transporting layer, the amount of the hole transporting compound is determined by hydrogenation of the hole transporting group with respect to the total weight of the charge transporting layer after curing. It is preferable that the product contains 20% by weight or more, preferably 40% by weight or more. If it is less than 20% by weight, the charge transport ability is lowered, and problems such as a reduction in sensitivity and an increase in residual potential are likely to occur. The thickness of the charge transport layer is preferably 1 to 50 μm, and particularly preferably 3 to 30 μm.

  When the hole transporting compound is used as a surface protective layer on the charge generation layer / charge transport layer, the charge transport layer corresponding to the lower layer is formed of a suitable charge transport material such as a complex such as poly-N-vinylcarbazole and polystyrylanthracene. Polymer compounds having rings and condensed polycyclic aromatics, heterocyclic compounds such as pyrazoline, imidazole, oxazole, triazole and carbazole, triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylene Applying a solution in which a low molecular weight compound such as a diamine derivative, N-phenylcarbazole derivative, stilbene derivative, or hydrazine derivative is dispersed / dissolved in a solvent together with an appropriate binder resin (can be selected from the aforementioned resin for charge generation layer) And can be formed by drying .

  In this case, the ratio of the charge transport material to the binder resin is preferably 30 to 100, particularly preferably 50 to 100, when the total weight of both is 100. If the amount of the charge transport material is less than 30, the charge transport ability is lowered, and problems such as a decrease in sensitivity and an increase in residual potential are likely to occur. The total thickness of the charge transport layer combined with the upper surface protective layer is preferably 1 to 50 μm, and particularly preferably 5 to 30 μm.

  In the present invention, in any of the above cases, the charge transport material can be contained in the surface layer of the photoreceptor containing the cured product of the hole transport compound having a chain polymerizable group.

  In the case of a single layer type photosensitive layer, it is formed by polymerizing / crosslinking a solution containing both a hole transporting compound and a charge generation material, or a single layer type photosensitive layer containing a charge generation material and a charge transport material It is formed by polymerizing / crosslinking after applying a solution containing a hole transporting compound thereon.

  Various additives can be added to the photoreceptor in the invention. Additives include anti-degradation agents such as antioxidants and ultraviolet absorbers, and lubricants such as fluorine atom-containing resin fine particles.

  Examples of the method for applying the solution for each layer include a dip coating method, a spray coating method, a curtain coating method, and a spin coating method. The dip coating method is preferable from the viewpoint of efficiency / productivity. Also, vapor deposition, plasma, and other known film forming methods can be appropriately selected.

  FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 in a direction indicated by an arrow at a predetermined peripheral speed. In the rotating process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then exposure light from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Receive 4. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1.

  The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner developed image is rotated between the photosensitive member 1 and the transfer unit 6 from a sheet feeding unit (not shown). The image is sequentially transferred by the transfer means 6 to the transfer material 7 that is synchronously taken out and fed. The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy).

  After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9 and further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown), and then repeatedly. Used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5 and the cleaning unit 9 described above are integrally coupled as a process cartridge. May be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photosensitive member 1 to form a cartridge and can be attached to and detached from the apparatus main body using guide means such as a rail 12 of the apparatus main body. The process cartridge 11 can be obtained.

  Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is a reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal, and scanning of the laser beam performed according to this signal, Light emitted by driving the LED array, driving the liquid crystal shutter array, or the like.

  The electrophotographic photosensitive member of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.

  Hereinafter, it demonstrates according to an Example. In the examples, “parts” represents parts by weight.

  First, the coating material for conductive layers was prepared by the following procedure. 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts of phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average 0.002 part of molecular weight 3000) was prepared by dispersing for 2 hours in a sand mill using φ1 mm glass beads. This paint was applied on an aluminum cylinder having a diameter of 30 mm by a dip coating method and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.

  Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare an intermediate layer coating material. This paint was applied onto the conductive layer by a dip coating method and dried at 100 ° C. for 20 minutes to form a 0.6 μm intermediate layer.

  Next, 5 parts of a bisazo pigment of the following structural formula (A), 2 parts of polyvinyl butyral resin and 60 parts of cyclohexanone are dispersed for 24 hours in a sand mill apparatus using φ1 mm glass beads, and 60 parts of tetrahydrofuran is further added to form a charge generation layer. Paint was used. This paint was applied onto the intermediate layer by a dip coating method and dried at 100 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.2 μm.

次いで、下記構造式（B）の正孔輸送性化合物６０部と

Next, 60 parts of a hole transporting compound of the following structural formula (B)

ポリイソブチレン（数平均分子量：２５００、アクリル酸への溶解度１０ｗｔ％以上、主鎖切断タイプ、Ｇ値：４．５5）１０部をモノクロロベンゼン３０部／ジクロロメタン３０部の混合溶媒中に溶解し、電荷輸送層用塗料を調製した。この塗料を前記の電荷発生層上にコーティングし、加速電圧１２０ＫＶ、線量１０Ｍｒａｄの条件で電子線を照射し樹脂を硬化し、膜厚１５μｍの電荷輸送層を形成し、電子写真感光体を得た。

10 parts of polyisobutylene (number average molecular weight: 2500, solubility in acrylic acid of 10 wt% or more, main chain cleavage type, G value: 4.55) is dissolved in a mixed solvent of 30 parts monochlorobenzene / 30 parts dichloromethane, A coating for the transport layer was prepared. This paint was coated on the charge generation layer, and the resin was cured by irradiating an electron beam under the conditions of an acceleration voltage of 120 KV and a dose of 10 Mrad to form a charge transport layer having a film thickness of 15 μm to obtain an electrophotographic photosensitive member. .

  The produced electrophotographic photosensitive member was evaluated for precipitation with time, electrophotographic characteristics, and durability. With regard to precipitation over time, a urethane rubber cleaning blade for a copying machine was pressed against the surface of the photoreceptor, stored at 80 ° C., and an accelerated test for precipitation was performed. In the evaluation, the surface of the photoreceptor was observed with a microscope after 14 days to determine the presence or absence of precipitation. When there was no precipitation, the test was continued until 30 days later.

  The electrophotographic characteristics and durability were evaluated by mounting this photoreceptor on a Canon Co., Ltd. copier GP405. Initial photosensitive member characteristics [dark portion potential Vd, light attenuation sensitivity (light amount necessary for light attenuation to −150 V when dark portion potential −700 V is set) and residual potential Vs1 (light amount three times the light attenuation sensitivity) ), And a 20000 sheet endurance test was performed to visually observe the occurrence of image defects, the amount of photoconductor scraping, and the photoconductor characteristics after endurance were measured. Change values ΔVd, ΔVl (difference between initial Vl and Vl when irradiation with the same amount of light as that required to initially set Vl to −150 V after endurance) and ΔVsl were obtained.

  The results are shown in Table 2. In the photoconductor of the present invention, no precipitation occurs, the photoconductor characteristics are good, the amount of abrasion is small, and there is almost no change in the photoconductor characteristics even in durability. It shows very stable and good characteristics, such as not being seen.

(Examples 2 to 10)
Electrophotographic photosensitivity in the same manner as in Example 1 except that the hole transporting compound and the polymer or oligomer to be mixed (solubility, reaction type upon irradiation and G value) are replaced with the compounds shown in Table 3. A body was made and evaluated. The results are shown in Table 2.

（実施例１１〜１５）
電子線の照射条件を下表４に示したように変えた以外は、実施例１と同様にして電子写真感光体を作製し、評価した。結果、削れ量、耐久画像は良好であったが、線量を０．５Ｍｒａｄより下げると若干削れ量が増加し、線量を２０Ｍｒａｄより上げることで初期の電子写真特性において、若干の感度低下や残留電位の上昇が見られた。結果を第２表に示す。

(Examples 11 to 15)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the electron beam irradiation conditions were changed as shown in Table 4 below. As a result, the shaving amount and the durable image were good, but when the dose was lowered below 0.5 Mrad, the shaving amount increased slightly, and by raising the dose above 20 Mrad, in the initial electrophotographic characteristics, there was a slight decrease in sensitivity and residual potential. The rise of was seen. The results are shown in Table 2.

（実施例１６）

(Example 16)

  The charge generation layer was formed in the same manner as in Example 1.

  Next, 20 parts of a styryl compound of the following structural formula (C),

及び下記構造式（Ｄ）の繰り返し単位を有するポリカーボネート樹脂（数平均分子量２０，０００）１０部

And 10 parts of a polycarbonate resin (number average molecular weight 20,000) having a repeating unit of the following structural formula (D)

をモノクロロベンゼン５０部／ジクロロメタン２０部の混合溶媒中に溶解して調製した電荷輸送層用塗料を用いて、前記電荷発生層上に電荷輸送層を形成した。この時の電荷輸送層の膜厚は１０μｍであった。

A charge transport layer was formed on the charge generation layer using a charge transport layer coating material prepared by dissolving in a mixed solvent of 50 parts of monochlorobenzene / 20 parts of dichloromethane. At this time, the thickness of the charge transport layer was 10 μm.

Next, 60 parts of the hole transporting compound used in Example 1 and 15 parts of polybutadiene (number average molecular weight: 2000, solubility in acrylic acid of 10 wt% or more, crosslinking type, G value: 3.5) were added to 50 parts of monochlorobenzene. / Dissolved in a mixed solvent of 50 parts of methylal to prepare a coating material for the surface protective layer. This paint is applied on the charge transport layer by spray coating, and the resin is cured by irradiating with an electron beam under the conditions of an acceleration voltage of 150 KV and a dose of 0.8 Mrad to form a surface protective layer having a thickness of 4 μm. A photographic photoreceptor was obtained. This photoreceptor was evaluated in the same manner as in Example 1. The results are shown in Table 2.
(Example 17)

The hole transporting compound was changed to the hole transporting compound used in Example 6, and polybutadiene was replaced with polyisoprene (number average molecular weight: 4500, solubility in acrylic acid of 1 wt% or more, crosslinking type, G value: 1.9). An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 16 except that the above was changed. The results are shown in Table 2.
(Example 18)

The hole transporting compound was changed to the hole transporting compound used in Example 5, and polybutadiene was replaced with polymethyl methacrylate (number average molecular weight: 25000, solubility in acrylic acid of 10 wt% or more, main chain cleavage type, G value: An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 16 except that it was changed to 1.8). The results are shown in Table 2.
(Example 19)

  Except that the amount of the hole transporting compound used in Example 6 was 45 parts and 15 parts of the acrylic monomer of the structural formula (E) was added,

実施例１６と同様にして電子写真感光体を作製し、評価した。結果を第２表に示す。

An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 16. The results are shown in Table 2.

(Comparative Example 1)
The charge generation layer was formed in the same manner as in Example 1.

  Next, a charge transport layer coating material prepared by dissolving 15 parts of a styryl compound of the structural formula (C) and 15 parts of a polymethyl methacrylate resin (number average molecular weight 40000) in a mixed solvent of 50 parts of monochlorobenzene / 20 parts of dichloromethane was prepared. A charge transport layer was formed on the charge generation layer. The thickness of the charge transport layer at this time was 15 μm.

  As a result of evaluating this electrophotographic photosensitive member in the same manner as in Example 1, precipitation was observed after 14 days. On the other hand, although the initial electrophotographic characteristics were good, the amount of abrasion of the surface layer in durability was large, and image defects such as fogging and scratches occurred. Further, after 9000 sheets, the thickness of the charge transport layer was reduced by scraping, resulting in poor charging and image formation became impossible. The results are shown in Table 2.

(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the polycarbonate resin (number average molecular weight 20000) represented by the structural formula (D) was used instead of the polymethyl methacrylate resin used in Comparative Example 1. evaluated. As a result, precipitation was observed after 30 days. Further, although the durability was slightly improved as compared with the case of the polymethylmethacrylate resin, it was not sufficient, and image defects after durability were generated. The results are shown in Table 2.

(Comparative Example 3)
A photoconductor of Comparative Example 3 was prepared and evaluated in the same manner as in Example 16 except that the surface protective layer in Example 16 did not contain polybutadiene. As a result, precipitation did not occur and the electrophotographic characteristics were good, but the initial electrophotographic characteristics were good. However, the durability of 20000 sheets was such that shallow scratches occurred on the surface of the photoreceptor, and thin image defects were seen in the halftone image. The results are shown in Table 2.

(Comparative Examples 4, 5, 6)
In Example 16, instead of polybutadiene, polymethyl acrylate (number average molecular weight 20000, solubility in acrylic acid of 10 wt% or more, crosslinking type, G value 0.5), polytetrafluoroethylene particles (number average) Molecular weight: 40000, solubility in acrylic acid of 0.1 wt% or less, number average particle size: 0.2 μm, main chain cleavage type, G value 1.5), poly α-methylstyrene (number average molecular weight: 12000, acrylic The photoconductors of Comparative Examples 4, 5, and 6 were prepared and evaluated in the same manner as in Example 16 except that the solubility in acid was 1 wt% or more, the main chain was cut, and the G value was 0.25. As a result, in any of Comparative Examples 4, 5, and 6, precipitation did not occur and the electrophotographic characteristics were good, but the initial electrophotographic characteristics were good. Thin image defects were seen in the image. The results are shown in Table 2.

1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

Claims (15)

  In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface layer of the photosensitive member has at least a hole-transporting compound having a chain polymerizable functional group and a terminal of the chain polymerizable functional group hydrogenated. Cured by polymerizing or crosslinking by irradiation with a mixture containing a polymer or oligomer that is soluble in the compound by 1% by weight or more and whose reaction by irradiation is a main chain cleavage type and whose G value is 0.5 or more. An electrophotographic photoreceptor comprising a compound.   In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the surface layer of the photosensitive member has at least a hole-transporting compound having a chain polymerizable functional group and a terminal of the chain polymerizable functional group hydrogenated. A compound cured by polymerizing or crosslinking by irradiation with a mixture containing a polymer or oligomer that is soluble in the compound by 1% by weight or more and has a crosslinking type reaction caused by irradiation and a G value of 1.0 or more. An electrophotographic photosensitive member containing the electrophotographic photosensitive member.   3. The electrophotographic photosensitive member according to claim 1, wherein the surface layer of the photosensitive member contains at least a hole transporting compound in the electrophotographic photosensitive member having a photosensitive layer on a conductive support. The electrophotographic photosensitive member according to claim 1, wherein the chain polymerizable functional group is an unsaturated polymerizable functional group represented by the following general formula (1).

(E is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent and an aryl group which may have a substituent, a cyano group, a nitro group, an alkoxy group, -COOR ¹ (R ¹ is a hydrogen atom, A halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and an aryl group which may have a substituent, CONR ² R ³ (R ² and R ³ are hydrogen atoms) , A halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, and an aryl group which may have a substituent, which may be the same or different from each other W represents a divalent aryl group which may have a substituent or a divalent alkylene group which may have a substituent, —COO—, —CH ₂ —, —O—, —OO—. , -S -, - CONR ⁴ -
(R ⁴ represents a hydrogen atom, a halogen 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); f is 0 or 1) The electrophotographic photosensitive member according to claim 1, wherein the chain polymerizable functional group is any one of the following formulas (2) to (6).

  The electrophotographic photoreceptor according to claim 1, wherein the hole transporting compound having a chain polymerizable functional group is a hole transporting compound having two or more chain polymerizable functional groups in the same molecule.   The electrophotographic photosensitive member according to claim 1, wherein the radiation is an electron beam.   The electrophotographic photosensitive member according to claim 1, wherein an electron beam irradiation amount is in a range of 0.5 to 20 Mrad.   2. The electrophotographic photosensitive member according to claim 1, wherein the polymer or oligomer whose reaction by radiation irradiation is a main chain cleavage type and whose G value is 0.5 or more is polyisobutylene.   3. The polymer or oligomer in which the reaction by radiation irradiation is a crosslinking type and the G value is 1.0 or more is a compound having an unsaturated carbon-carbon double bond in a repeating unit of the chemical structure. Electrophotographic photoreceptor.   The electrophotographic photosensitive member according to claim 10, wherein the polymer or oligomer whose reaction by radiation irradiation is a crosslinking type and whose G value is 1.0 or more is a butadiene-based synthetic rubber.   The electrophotographic photosensitive member according to claim 10, wherein the polymer or oligomer whose reaction by radiation irradiation is a crosslinking type and has a G value of 1.0 or more is an isoprene-based synthetic rubber.   The electrophotographic photosensitive member according to any one of claims 1 to 12, and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means are integrally supported and detachably attached to the electrophotographic apparatus main body. A process cartridge characterized by being.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.   In the method for producing an electrophotographic photosensitive member for forming a photosensitive layer on a support, the method includes a step of curing by polymerizing or crosslinking a hole transporting compound having two or more chain polymerizable functional groups in the same molecule. A method for producing an electrophotographic photosensitive member.

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