JP2007279288A - Electrophotographic photoreceptor, method for manufacturing the same, image forming method and image forming apparatus using the same, and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form high-quality images for a long time by reducing the degradation of positive charging property due to repeated use. <P>SOLUTION: The electrophotographic photoreceptor having at least a photosensitive layer and a surface layer on a conductive support is disclosed, which is characterized in that: the surface layer is formed of a crosslinked resin film by irradiating with UV rays a monomer mixture containing (α) radical polymerizable monomers having three or more functional groups and no charge transporting structure and (β) a radical polymerizable compound having a charge transporting structure; the irradiation energy of UV rays is controlled at 2 J/cm<SP>2</SP>to 7 J/cm<SP>2</SP>; and the highest temperature of the photoreceptor surface during irradiation with UV rays is 70°C to 90°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides an electrophotographic photosensitive material that realizes stable electric characteristics and high-quality image formation over a long period of time as well as excellent durability by using a crosslinked surface layer having high wear resistance and good electric characteristics. The present invention relates to a body and a manufacturing method thereof. The present invention also relates to an image forming method, an image forming apparatus, and a process cartridge for the image forming apparatus using those long-life, high-performance photoconductors.

  In recent years, organic photoreceptors (OPC) have been widely used in copying machines, facsimile machines, laser printers, and composite machines in place of inorganic photoreceptors because of their good performance and various advantages. The reasons for this are, for example, (i) optical characteristics such as the light absorption wavelength range and the amount of absorption, (ii) electrical characteristics such as high sensitivity and stable charging characteristics, and (iii) material selection range. (Iv) ease of production, (v) low cost, (vi) non-toxicity, and the like.

  On the other hand, the diameter of the photoconductor has recently been reduced due to the downsizing of the image forming apparatus, and the high speed of the machine and the maintenance-free movement have been added to increase the durability of the photoconductor. From this point of view, organophotoreceptors are generally soft because the surface layer is mainly composed of low-molecular charge transport materials and inert polymers, and when used repeatedly in electrophotographic processes, they are mechanically driven by development systems and cleaning systems. There is a drawback that wear is likely to occur due to a typical load. In addition, due to the demand for higher image quality, the cleaning blade is required to increase its rubber hardness and contact pressure for the purpose of improving the cleaning property as the particle size of the toner particles is reduced. This also promotes the wear of the photoreceptor. It is a factor. Such abrasion of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning. Under the present circumstances, the wear and scratches are rate-determined and the life of the photoconductor has been replaced.

  Therefore, it is indispensable to reduce the amount of wear as described above in order to increase the durability of the organic photoreceptor, and an organic photoreceptor having a good surface property is required in order to impart excellent cleaning properties and transferability. These are the most pressing issues in the field.

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

  Furthermore, a photoreceptor containing a polyfunctional curable acrylate monomer in order to improve the abrasion resistance and scratch resistance of (1) is also known (Patent Document 4). However, in this photoreceptor, although there is a description that the polyfunctional curable acrylate monomer is contained in the protective layer provided on the photosensitive layer, the protective layer may contain a charge transport material. However, when the surface layer contains a low-molecular charge transporting substance, there is a problem of compatibility with the cured product. In some cases, the molecular charge transport material is precipitated and cracks are generated, and the mechanical strength is also lowered. There is also a description that a polycarbonate resin is contained for improving compatibility, but the content of the curable acrylic monomer is reduced, and as a result, sufficient wear resistance cannot be achieved. In addition, regarding a photoconductor that does not include a charge transport material in the surface layer, there is a description that the surface layer is a thin film in order to lower the potential of the exposed portion, but the life of the photoconductor is short because the film is thin. In addition, the environmental stability of the charging potential and the exposure portion potential is poor, and the value fluctuates greatly due to the influence of the temperature and humidity environment, and it is not possible to maintain a sufficient value.

  As an alternative anti-wear technique for photosensitive layers, a charge transport layer formed by using a coating solution comprising a monomer having a carbon-carbon double bond, a charge transport material having a carbon-carbon double bond, and a binder resin is used. It is known (Patent Document 5) that this binder resin has a carbon-carbon double bond and is reactive to the charge transporting substance, and has no double bond. Those having no reactivity are included. This photoconductor is remarkably compatible with wear resistance and good electrical properties. However, when a non-reactive binder resin is used, the binder resin, the monomer, and the charge transport material are used. The compatibility with the cured product produced by this reaction was poor, and surface irregularities were generated during cross-linking from layer separation, and a tendency to cause poor cleaning was observed. Further, as described above, in this case, the binder resin prevents the curing of the monomer, and what is specifically described as the monomer used in the photoreceptor is a bifunctional one. The monomer has a small number of functional groups and a sufficient crosslinking density cannot be obtained, and it has not yet been satisfactory in terms of wear resistance. Further, even when a reactive binder is used, due to the low number of functional groups contained in the monomer and the binder resin, it is difficult to achieve both the binding amount and the crosslinking density of the charge transport material, and the electrical characteristics and The abrasion resistance was not sufficient.

  A photosensitive layer containing a compound obtained by curing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule is also known (Patent Document 6). However, in this photosensitive layer, the bulky hole transporting compound has two or more chain-polymerizable functional groups, so that distortion occurs in the cured product, resulting in high internal stress, resulting in rough surface layers and cracks over time. It may be easy to do and does not have sufficient durability.

  Furthermore, a crosslinked charge transport layer obtained by curing a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a monofunctional radical polymerizable compound having a charge transport structure is also known (Patent Document 7, Patent Document 8, Patent Document 9) Using a monofunctional radically polymerizable compound having a charge transporting structure and curing the surface layer suppresses cracking of the photosensitive layer as well as mechanical and electrical durability. ing. These photoreceptors are polymerized with a radically polymerizable monomer by irradiating with ultraviolet rays to form a crosslinked surface layer, thereby improving the wear resistance.

  Moreover, it is known that the electrical characteristics of the photoconductor change depending on the temperature of the photoconductor at the time of ultraviolet irradiation (Patent Documents 10 and 11) in curing the surface layer by ultraviolet irradiation as described above. By controlling the surface temperature, an increase in the residual potential after repeated use is suppressed, and a decrease in image quality such as a decrease in density is prevented.

  However, these photoconductors have not been studied for abnormal images resulting from material deterioration due to ultraviolet irradiation. With ultraviolet irradiation energy required for sufficient curing, the reaction becomes non-uniform, and the charge transport material in the crosslinked surface layer may deteriorate, unreacted groups, and reaction termination terminals may occur. In such a case, in a negatively charged electrophotographic photosensitive member, after repeated use in the electrophotographic process, when a positive potential is applied in the electrostatic transfer process, a positive charge is injected into the photosensitive member. In some cases, an abnormal image such as an afterimage is generated in the electrophotographic process after the second round. For this reason, it cannot be said that the above-described photoreceptors (Patent Documents 7 to 11) that perform ultraviolet irradiation achieve wear resistance and long-term high-quality image formation at the same time.

For the above reasons, it cannot be said that the conventional photoreceptors having a crosslinked surface layer in which a charge transporting structure is chemically bonded by ultraviolet irradiation also have sufficient comprehensive properties at present.
JP 56-48637 A JP-A 64-1728 JP-A-4-281461 Japanese Patent No. 3262488 Japanese Patent No. 3194392 JP 2000-66425 A JP 2004-302450 A JP 2004-302451 A JP 2004-302452 A JP 59-162559 A JP 2001-125297 A

  The object of the present invention is to form a cross-linked surface layer by irradiating with ultraviolet rays, thereby providing excellent durability, and at the same time preventing deterioration of electrical characteristics due to ultraviolet irradiation, and reducing positive chargeability by repeated use. An object of the present invention is to provide an electrophotographic photosensitive member capable of reducing and realizing high-quality image formation over a long period of time, and a manufacturing method thereof. 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 long life and high performance photoconductor.

In the electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, the present inventors provide a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a charge transporting property. a monomer mixture containing a radically polymerizable compound having a structure formed by crosslinking the resin film was cured by irradiation with ultraviolet rays, light energy at the ultraviolet 2J / cm ² or more 7J / cm is ² or less The present invention has been completed by discovering that the above-mentioned problems can be achieved by setting the maximum temperature reached on the surface of the photoreceptor at 70 ° C. to 90 ° C. during ultraviolet irradiation.

The first of the present invention is an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, wherein the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, the light energy at the ultraviolet rays, 2J / cm ² or more 7J / cm ² or less, the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is less than 90 ° C. 70 ° C. or higher The present invention relates to a characteristic electrophotographic photosensitive member.

The second invention relates to an electrophotographic photosensitive member of the first, wherein the irradiation intensity of the ultraviolet rays is 500 mW / cm ² or more 1000 mW / cm ² or less.
According to a third aspect of the present invention, the maximum temperature reached on the surface of the photosensitive member is reached by radiant heat of ultraviolet irradiation light energy, and the temperature is controlled by flowing air through the support. Or it relates to the electrophotographic photosensitive member described in the second item.

A fourth aspect of the present invention relates to the electrophotographic photosensitive member according to any one of the first to third aspects, wherein an initial temperature of the surface of the photosensitive member before ultraviolet irradiation is 30 ° C. or lower.
According to a fifth aspect of the present invention, in the first to fourth aspects, the rate of decrease of the positive charging potential of the photoconductor is 50% or less, and the elastic power of the surface layer is 52% or more. The electrophotographic photoreceptor according to any one of the above.

In a sixth aspect of the present invention, the charge transporting structure (b) is selected from the group consisting of a triarylamine structure, a hydrazone structure, a pyrazoline structure, and a carbazole structure. The electrophotographic photoreceptor according to any one of the fifth aspect.
A seventh aspect of the present invention relates to the electrophotographic photosensitive member according to any one of the first to sixth aspects, wherein the charge transporting structure (b) is a triarylamine structure.

In an eighth aspect of the present invention, the radically polymerizable compound (b) has a functional group selected from the group consisting of an acryloyloxy group and a methacryloyloxy group. The electrophotographic photosensitive member according to any one of the above.
A ninth aspect of the present invention relates to the electrophotographic photosensitive member according to any one of the first to eighth aspects, wherein the number of functional groups of the radical polymerizable compound (b) is one.

A tenth aspect of the present invention is characterized in that the trifunctional or higher functional radical polymerizable monomer of (i) has three or more functional groups selected from the group consisting of an acryloyloxy group and a methacryloyloxy group. The electrophotographic photosensitive member according to any one of the first to ninth aspects.
An eleventh aspect of the present invention is any one of the first to tenth aspects, wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a crosslinked surface layer from the support side. The present invention relates to an electrophotographic photoreceptor.

A twelfth aspect of the present invention is the method for producing an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, wherein the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, characterized in that the light quantity of ultraviolet irradiation, 2J / cm ² or more 7J / cm ² or less, the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is less than 90 ° C. 70 ° C. or higher The present invention relates to a method for producing an electrophotographic photoreceptor.
A thirteenth aspect of the present invention relates to an image forming method, wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member according to any one of the first to eleventh aspects. .

A fourteenth aspect of the present invention relates to an image forming apparatus comprising the electrophotographic photosensitive member according to any one of the first to eleventh aspects.
According to a fifteenth aspect of the present invention, there is provided at least one selected from the group consisting of the electrophotographic photosensitive member according to any one of the first to eleventh aspects, a charging unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. The present invention relates to a process cartridge for an image forming apparatus, characterized in that the process cartridge is detachable from an image forming apparatus main body.

In the electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on the conductive support of the present invention, the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, light energy at the ultraviolet rays, 2J / cm ² or more 7J / cm ² or less, by the maximum temperature of the photosensitive member surface is 90 ° C. or less 70 ° C. or higher at the time of irradiation of ultraviolet light Thus, an electrophotographic photosensitive member having high abrasion resistance and stable electrical characteristics over a long period of time and capable of maintaining a high-quality image is realized. In addition, the method for producing a photoconductor, the image forming process using the photoconductor, the image forming apparatus, and the process cartridge for the image forming apparatus of the present invention have high performance and high reliability.

The present invention will be described in detail below. The present invention is based on the following basic idea.
The photoreceptor of the present invention uses a tri- or higher functional radical polymerizable monomer having no charge transporting structure on the surface layer, thereby developing a three-dimensional network structure and a high hardness cross-linking having a very high cross-linking density. A surface layer is obtained and high wear resistance is achieved. On the other hand, when only a monomer having few radical polymerizable functional groups is used, the crosslink density in the cross-linked surface layer becomes dilute, and a dramatic improvement in wear resistance cannot be achieved. When the crosslinked surface layer contains another polymer material, the development of the three-dimensional network structure is hindered and the degree of crosslinking is lowered, so that sufficient wear resistance cannot be obtained as compared with the present invention. Furthermore, from the reaction between the other polymer material contained and the radical polymerizable composition of the present invention (a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure). The compatibility with the resulting cured product is poor, and local wear occurs from the phase separation, which appears as a scratch on the surface.

  In addition, in the formation of the crosslinked surface layer of the present invention, in addition to the trifunctional or higher functional radical polymerizable monomer having no charge transport structure, a radical polymerizable compound having a charge transport structure is contained. At the same time, it was polymerized and cured in a short time to form a hardened cross-linked bond, and an improvement in durability was achieved. Furthermore, it became possible to form a smooth surface layer by improving the curing rate, and it became possible to maintain a good cleaning property for a long period of time. Furthermore, the crosslinking layer is distorted by curing a radically polymerizable monomer having a charge transporting structure and a trifunctional or higher-functional radically polymerizable monomer having a large number of reactive functional groups and a fast curing speed and having no charge transporting structure. It is possible to form a uniform crosslinked film with a small amount of particles, and as a result, the unreacted portion of the charge transport material is reduced in the crosslinked surface layer, and the homogeneity inside the crosslinked film is greatly improved. As a result, it was possible to achieve both an improvement in wear resistance and a stable electrostatic property and an electrophotographic photoreceptor free from cracks. In other words, various characteristics such as abrasion resistance, cleaning properties, and electrical characteristics of the photoconductor do not depend on the location of the photoconductor, and both stable wear resistance and long-term image formation are realized for long-term paper passing. Further, since a radical polymerizable compound having a charge transporting structure is incorporated in the cross-linked layer, stable electric characteristics are exhibited over a long period of time. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linked surface layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the cross-linked surface layer The mechanical strength also decreases.

Further, in the present invention, the surface layer formed of the radical polymerizable compound is polymerized and crosslinked by irradiating with ultraviolet rays. At this time, when the irradiation light energy is small, a sufficient cross-linked structure cannot be obtained, and high wear resistance cannot be obtained. Moreover, when irradiation light energy is large, the electrical property of a bridge | crosslinking surface layer may be reduced. In such a case, after repeated use in the electrophotographic process, positive charges are injected into the photoconductor in the electrostatic transfer process and trapped inside, and abnormal images such as afterimages are generated in the electrophotographic process after the second round. May occur. When such an afterimage is generated, the positive chargeability on the surface of the photoreceptor is lowered, and the positive charge injection property is increased. In other words, by reducing the decrease in positive chargeability, it is possible to suppress the occurrence of afterimages. Specifically, by reducing the rate of decrease in positive charge potential due to electrostatic fatigue in repeated use to 50% or less. Generation of afterimages is suppressed. In the present invention, the light energy at the ultraviolet and 2J / cm ² or more 7J / cm ² or less, that further the maximum temperature of the surface of the photoreceptor at the time of ultraviolet irradiation and 70 ° C. or higher 90 ° C. or less, crosslinking by ultraviolet irradiation Sufficient cross-linking in the surface layer while suppressing deterioration of the charge transport material in the surface layer, generation of unreacted groups and reaction terminating groups, and reducing the rate of decrease of positive charging potential by repeated use to 50% or less It has been found that a surface layer having a high wear resistance in which a structure can be formed and an elastic power of the crosslinked surface layer is 52% or more can be constructed. In other words, by having a cross-linked surface layer with a sufficient cross-linked structure, high wear resistance can be realized, and at the same time, reduction in positive chargeability due to repeated use in the electrophotographic process can be reduced, such as afterimage It is possible to realize an electrophotographic photosensitive member that does not generate an abnormal image.

In the present invention, in an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, the surface layer has a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a charge transporting structure. a monomer mixture containing a radically polymerizable compound having, formed by crosslinking a resin film was cured by irradiation with ultraviolet rays, the light energy at the ultraviolet, and 2J / cm ² or more 7J / cm ² or less, By setting the maximum temperature on the surface of the photoreceptor at the time of ultraviolet irradiation to 70 ° C. or more and 90 ° C. or less, an electrophotographic photoreceptor having high wear resistance and stable electrical characteristics over a long period can be realized.

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

As the 1-substituted ethylene functional group, for example, a functional group represented by the following general formula (1) is preferably exemplified.
General formula (1)
CH ₂ = CH-X ₁ -
However, in said general formula (1), X < ₁ > is arylene groups, such as phenylene group which may have a substituent, a naphthylene group, alkenylene group which may have a substituent, -CO- group, —COO— group, —CON (R ₃₀ ) — group (wherein R ₃₀ represents a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group, a naphthylmethyl group or a phenethyl group, a phenyl group, Represents an aryl group such as a naphthyl group) or an S-group.
Specific examples of these substituents include vinyl, styryl, 2-methyl-1,3-butadienyl, vinylcarbonyl, acryloyloxy, acryloylamide, and vinylthioether groups.

As the 1,1-substituted ethylene functional group, for example, a functional group represented by the following general formula (2) is preferably exemplified.
General formula (2)
_{CH 2 = C (Y) -X} 2 -
In the general formula (2), Y represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, or naphthyl. An aryl group such as a group, an alkoxy group such as a halogen atom, a cyano group, a nitro group, a methoxy group or an ethoxy group, a —COOR ₃₁ group (where R ₃₁ is a hydrogen atom or an optionally substituted methyl group) , An alkyl group such as an ethyl group, an optionally substituted benzyl, an aralkyl group such as a phenethyl group, an optionally substituted phenyl group, an aryl group such as a naphthyl group, or CONR ₃₂ R ₃₃ (However, R ₃₂ and R ₃₃ are each a hydrogen atom, an alkyl group such as an optionally substituted methyl group, an ethyl group, a benzyl group optionally having a substituent, a naphthylmethyl group, or a phenethyl group. Basics Aralkyl group, or a substituent a phenyl group which may have a represents an aryl group such as a naphthyl group, may be the same or different from each other.) Further, X ₂ is X ₁ in the general formula (1) And the same substituent, a single bond, and an alkylene group, provided that at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, and an aromatic ring.
Examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

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

  Among these radical polymerizable functional groups, an acryloyloxy group and a methacryloyloxy group are particularly useful, and a compound having three or more acryloyloxy groups includes, for example, a compound having three or more hydroxyl groups in the molecule. It can be obtained by an ester reaction or a transesterification reaction using acrylic acid (salt), acrylic acid halide, and acrylic ester. A compound having three or more methacryloyloxy groups can be obtained in the same manner. Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

Specific examples of the trifunctional or higher-functional radical polymerizable monomer (a) having no charge transporting structure include the following, but are not limited to these compounds.
That is, examples of the radical polymerizable monomer (A) used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified (alkylene-modified) trimethylolpropane triacrylate, EO-modified ( (Ethyleneoxy modified) trimethylolpropane triacrylate, PO modified (propyleneoxy modified) trimethylolpropane triacrylate, caprolactone modified trimethylolpropane triacrylate, HPA modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA) ), Glycerol triacrylate, ECH-modified (epichlorohydrin-modified) glycero Triacrylate, EO modified glycerol triacrylate, PO modified glycerol triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl modified Dipentaerythritol pentaacrylate, alkyl-modified dipentaerythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphate triacrylate, 2, 2, 5, 5, -tetrahydroxymethylcyclopentanone tetra Such as acrylate and the like, which can be used in combination either alone or in combination. The reason for the modification is to lower the viscosity of the monomer and make it easier to handle.

  The trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention is a ratio of molecular weight to the number of functional groups in the monomer in order to form a dense crosslink in the cross-linked surface layer. (Molecular weight / functional group number) is preferably 250 or less. Further, when this ratio is larger than 250, the crosslinked surface layer is soft and wear resistance is somewhat lowered. Therefore, among the monomers exemplified above, monomers having a modifying group such as HPA, EO, and PO are extremely long. It is not preferable to use one having a modifying group alone.

  Moreover, the component ratio of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure used for the crosslinked surface layer is 20 to 80% by weight, preferably 30 to 70% by weight, based on the total amount of the crosslinked surface layer. When the monomer component is less than 20% by weight, the three-dimensional cross-linking density of the cross-linked surface layer is small, and a drastic improvement in wear resistance is not achieved as compared with the case of using a conventional thermoplastic binder resin. On the other hand, if it is 80% by weight or more, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  The radically polymerizable compound having a (b) charge transporting structure used in the present invention is a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, etc. A compound having an electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having a radical polymerizable functional group. Examples of the radical polymerizable functional group include those previously shown for the radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. As the charge transporting structure, a triarylamine structure is highly effective.

〔式中、Ｒ₁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、−ＣＯＯＲ₂（Ｒ₂は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ₃Ｒ₄（Ｒ₃及びＲ₄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、Ａｒ₁、Ａｒ₂は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_3、Ａｒ₄は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わし、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し、ｍとｎは０〜３の整数を表わす。〕 Furthermore, when a compound represented by the structure of the following general formula (3) or (4) is used, electrical characteristics such as sensitivity and residual potential are favorably maintained.

[Wherein R ₁ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, Group, alkoxy group, —COOR ₂ (R ₂ is a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent), halogen Carbonyl group or CONR ₃ R ₄ (R ₃ and R ₄ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Represents a good aryl group, which may be the same or different, and Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, which may be the same or different. Ar _{3 and} Ar ₄ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group, and Z represents a substituted or unsubstituted alkylene. Represents a group, a substituted or unsubstituted alkylene ether group or an alkyleneoxycarbonyl group, and m and n each represents an integer of 0 to 3; ]

In the general formulas (3) and (4), examples of the alkyl group in R ₁ include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the aryl group include a phenyl group and a naphthyl group. As benzyl group, phenethyl group, naphthylmethyl group, and alkoxy groups include methoxy group, ethoxy group, propoxy group, etc., which are halogen atom, nitro group, cyano group, methyl group, ethyl group, respectively. Or an alkyl group such as methoxy group or ethoxy group, an aryloxy group such as phenoxy group, an aryl group such as phenyl group or naphthyl group, an aralkyl group such as benzyl group or phenethyl group, etc. . Particularly preferred among R ₁ are a hydrogen atom and a methyl group.

Ar ₃ and Ar _{4 each} represents a substituted or unsubstituted aryl group. In the present invention, the aryl group includes a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group, and includes the following groups.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an As-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.

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

The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) Alkyl groups, preferably C ₁ -C _12, especially C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkyl groups, and these alkyl groups further contain fluorine atoms , a hydroxyl group, a cyano group, an alkoxy group of C ₁ -C _4, a phenyl group or a halogen atom, which may have a phenyl group substituted by an alkoxy group C ₁ -C ₄ alkyl or C ₁ -C ₄ Good. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.

(3) An alkoxy group (—OR _a ), and R _a represents an alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) An aryloxy group, and examples of the aryl group include a phenyl group and a naphthyl group. It may contain an alkoxy group having C ₁ -C _4, alkyl group, or a halogen atom C ₁ -C ₄ as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group, and specific examples include methylthio group, ethylthio group, phenylthio group, p-methylphenylthio group and the like.

（式中、Ｒ₁₀及びＲ₁₁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Ｃ₁〜Ｃ₄のアルコキシ基、Ｃ₁〜Ｃ₄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。Ｒ₁₀及びＲ₁₁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。 (6)

(Wherein R ₁₀ and R ₁₁ each independently represents a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these C ₁ -C ₄ alkoxy groups, C ₁ -C good .R ₁₀ and R ₁₁ may contain, as a substituent, an alkyl group or a halogen atom ₄ may be linked to form a ring.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.

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

The arylene group represented by Ar ₁ or Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ or Ar ₄ .
X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.
The alkylene group for X is a C ₁ -C ₁₂ , preferably C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkylene group, and these alkylene groups further contain fluorine. atom, a hydroxyl group, a cyano group, optionally having a C ₁ -C ₄ alkoxy group, a phenyl group or a halogen atom, C ₁ -C phenyl group substituted by ₄ alkyl or alkoxy group of C ₁ -C ₄ Also good. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

The cycloalkylene group in X is a C _{5 to} C ₇ cyclic alkylene group, and these cyclic alkylene groups include a fluorine atom, a hydroxyl group, a C _{1 to} C ₄ alkyl group, and a C _{1 to} C ₄ alkoxy group. And may have a substituent such as Specific examples of the cycloalkylene group include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.

  The alkylene ether group in X represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, and the alkylene group of the alkylene ether group includes a hydroxyl group, a methyl group, an ethyl group, and the like. You may have a substituent.

で表わされ、Ｒ₁₂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Ａｒ₃、Ａｒ₄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。 The vinylene group in X is

R ₁₂ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), and 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.

（式中、ｐ、ｑ、ｏはそれぞれ０又は１の整数、Ｒ₅は水素原子、メチル基を表わし、Ｒ₆、Ｒ₇は水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚ₂は単結合、メチレン基、エチレン基、

を表わす。） Further, the radically polymerizable compound having a charge transport structure of the present invention is more preferably a compound having the structure of the following general formula (5).

(In the formula, p, q and o are each an integer of 0 or 1, R ₅ represents a hydrogen atom or a methyl group, and R ₆ and R ₇ represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. And a plurality of s and t each represent an integer of 0 to _3. Z ₂ represents a single bond, a methylene group, an ethylene group,

Represents. )

As the compound represented by the above general formula, compounds having a methyl group or an ethyl group as substituents for R ₆ and R ₇ are particularly preferable.
The radically polymerizable compound having the charge transport structure represented by the general formulas (3) and (4), particularly (5) used in the present invention is polymerized by opening a double bond between carbon and carbon on both sides. In a polymer incorporated in a chain polymer and crosslinked by polymerization with a tri- or higher functional radical polymerizable monomer, the polymer exists in the main chain of the polymer, and the main chain-main chain Present in the cross-linked chain (in this cross-linked chain, the inter-molecular cross-linked chain between one polymer and the other polymer, the site with the main chain folded in one polymer and the main chain In other words, there is an intramolecular cross-linked chain that is cross-linked with other sites derived from the polymerized monomer at a position away from this), but even if it is present in the main chain or in the cross-linked chain Even so, the triarylamine structure suspended from the chain moiety is radial from the nitrogen atom. It has at least three aryl groups arranged in the direction and is bulky, but is not directly bonded to the chain part, but is suspended from the chain part via a carbonyl group etc. Since these triarylamine structures can be arranged adjacent to each other in the polymer, the structural distortion in the molecule is small, and the surface layer of the electrophotographic photosensitive member In this case, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport pathway can be taken.

In the present invention, the specific acrylate compound represented by the following general formula (6) can also be used favorably as a radical polymerizable compound having a charge transporting structure.
General formula (6)
B ₁ —Ar ₅ —CH═CH—Ar ₆ —B ₂

Ar ₅ represents a monovalent group or a divalent group composed of a substituted or unsubstituted aromatic hydrocarbon skeleton. Examples of the aromatic hydrocarbon include benzene, naphthalene, phenanthrene, biphenyl, 1,2,3,4-tetrahydronaphthalene and the like.
Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a benzyl group, and a halogen atom. The alkyl group and alkoxy group may further have a halogen atom or a phenyl group as a substituent.

（式中、Ｒ₁₃、Ｒ₁₄はアシル基、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基を表す。Ａｒ₇はアリール基を表す。ｗは１〜３の整数を表す。） Ar ₆ represents a monovalent group consisting of an aromatic hydrocarbon skeleton having at least one tertiary amino group, a monovalent group consisting of a divalent group or a heterocyclic compound skeleton having at least one tertiary amino group, or Although it represents a divalent group, the aromatic hydrocarbon skeleton having a tertiary amino group is represented by the following general formula (7).

(Wherein R ₁₃ and R ₁₄ represent an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Ar ₇ represents an aryl group. W represents an integer of 1 to 3)

Examples of the acyl group for R ₁₃ and R ₁₄ include an acetyl group, a propionyl group, and a benzoyl group.
The substituted or unsubstituted alkyl group for R ₁₃ and R ₁₄ is the same as the alkyl group described for the substituent for Ar ₅ .
The substituted or unsubstituted aryl group for R ₁₃ and R ₁₄ is phenyl group, naphthyl group, biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group, azulenyl group, anthryl group, In addition to the triphenylenyl group and the chrycenyl group, a group represented by the following general formula (8) can be exemplified.

[式中、Ｂは−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＯ−及び以下の二価基から選ばれる。

（ここで、Ｒ₂₁は、水素原子、Ａｒ₅で定義された置換もしくは無置換のアルキル基、アルコキシ基、ハロゲン原子、Ｒ₁₃で定義された置換もしくは無置換のアリール基、アミノ基、ニトロ基、シアノ基を表し、Ｒ₂₂は、水素原子、Ａｒ₅定義された置換もしくは無置換のアルキル基、Ｒ₁₃で定義された置換もしくは無置換のアリール基を表し、ｉは１〜１２の整数、ｊは１〜３の整数を表す。）]

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

(Wherein R ₂₁ is a hydrogen atom, a substituted or unsubstituted alkyl group defined by Ar ₅ , an alkoxy group, a halogen atom, a substituted or unsubstituted aryl group defined by R ₁₃ , an amino group, a nitro group; Represents a cyano group, R ₂₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group defined by Ar ₅ , a substituted or unsubstituted aryl group defined by R ₁₃ , and i is an integer of 1 to 12, j represents an integer of 1 to 3)]

Specific examples of the alkoxy group of R ₂₁ include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, 2-hydroxyethoxy. Group, 2-cyanoethoxy group, benzyloxy group, 4-methylbenzyloxy group, trifluoromethoxy group and the like.

Examples of the halogen atom for R ₂₁ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the amino group of R ₂₁ include a diphenylamino group, a ditolylamino group, a dibenzylamino group, and a 4-methylbenzyl group.

Examples of the aryl group of Ar ₇ include a phenyl group, a naphthyl group, a biphenylyl group, a terphenylyl group, a pyrenyl group, a fluorenyl group, a 9,9-dimethyl-2-fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, and a chrysenyl group. Can do.
Ar ₇ , R ₁₃ and R ₁₄ may have an alkyl group, alkoxy group or halogen atom defined by Ar ₅ as a substituent.

Examples of the heterocyclic compound skeleton having a tertiary amino group include amines such as pyrrole, pyrazole, imidazole, triazole, dioxazole, indole, isoindole, benzimidazole, benzotriazole, benzisoxazine, carbazole, and phenoxazine. Examples include heterocyclic compounds having a structure. These may have an alkyl group, an alkoxy group, or a halogen atom defined by Ar ₅ as a substituent.

B ₁ and B ₂ represent an acryloyloxy group, a methacryloyloxy group, a vinyl group, an acryloyloxy group, a methacryloyloxy group, an alkyl group having a vinyl group, an acryloyloxy group, a methacryloyloxy group, or an alkoxy group having a vinyl group. As the alkyl group and alkoxy group, those described for Ar ₅ are similarly applied. Only _{one of} these B ₁ and B ₂ exists, and the presence of both is excluded.

式中、Ｒ₈、Ｒ₉は、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、ハロゲン原子を表し、Ａｒ₇、Ａｒ₈は、置換もしくは無置換のアリール基またはアリレン基、置換又は無置換のベンジル基をあらわす。アルキル基、アルコキシ基、ハロゲン原子は前記Ａｒ₅で述べたものが同様に適用される。 As a more preferable structure in the acrylic ester compound of the general formula (6), a compound of the following general formula (9) can be exemplified.

In the formula, R ₈ and R ₉ represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a halogen atom, and Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group or an arylene group, substituted Or an unsubstituted benzyl group is represented. As the alkyl group, alkoxy group, and halogen atom, those described for Ar ₅ are similarly applied.

The aryl group is the same as the aryl group defined by R ₁₃ and R ₁₄ . An arylene group is a divalent group derived from the aryl group.
B _{1 to} B ₄ are the same as B ₁ and B ₂ in the general formula (6). u represents an integer of 0 to 5, and v represents an integer of 0 to 4.

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

  From the above, the use of the charge transporting compound having a radical polymerizable functional group represented by the general formula (6), particularly the general formula (9), while maintaining good electrical characteristics and generating cracks and the like. A film having a very high crosslinking density can be formed without causing any problems, thereby satisfying various characteristics of the photoconductor, preventing silica fine particles from being stuck in the photoconductor, and reducing image defects such as white spots. be able to.

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

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

  Further, the radical polymerizable compound (b) having a charge transporting structure used in the present invention is important for imparting the charge transporting 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 trifunctional or higher-functional radical polymerizable monomer having no charge transport structure is lowered, and the crosslink density is lowered, so that high wear resistance is not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  The cross-linked surface layer of the present invention is a tri- or higher functional radical polymerizable compound in which the surface layer of the photosensitive layer has at least (i) a charge transporting structure in an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support. It is formed by curing a monomer and a radically polymerizable compound having a (b) charge transporting structure. In addition to this, viscosity adjustment during coating, stress relaxation of the cross-linked surface layer, lower surface energy and reduced friction coefficient Monofunctional and bifunctional radically polymerizable monomers, functional monomers and radically polymerizable oligomers can be used in combination for the purpose of imparting functions such as. Known radical polymerizable monomers and oligomers can be used.

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

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

  Examples of the functional monomer include those substituted with a fluorine atom such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, No. 60503, JP-B-6-45770, siloxane repeating units: 20-70 acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl polydimethylsiloxane Examples include vinyl monomers having a polysiloxane group such as diethyl, acrylates and methacrylates.

Examples of the radical polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers.
However, when a large amount of monofunctional and bifunctional radically polymerizable monomers and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the cross-linked surface layer is substantially reduced, resulting in a decrease in wear resistance. For this reason, the content of these monomers and oligomers is limited to 50 parts by weight or less, preferably 30 parts by weight or less with respect to 100 parts by weight of a tri- or higher functional radical polymerizable monomer.

  The surface layer of the present invention is an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, and the surface of the photosensitive layer has at least a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a charge. It is formed by applying a coating solution of a monomer mixture containing a radically polymerizable compound having a transporting structure, and polymerizing and curing this by ultraviolet irradiation. In order to advance the reaction efficiently, a photopolymerization initiator may be used in the coating solution composition.

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

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

  Furthermore, the coating liquid of the present invention can contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no radical reactivity as required. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20 wt% or less, preferably 10 wt% or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating liquid. 3% by weight or less is appropriate.

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

In this invention, after apply | coating this coating liquid, the light energy by an ultraviolet-ray is given and hardened, and a crosslinked surface layer is formed. As the light energy, an ultraviolet light source such as a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, or a metal halide lamp having a wavelength in ultraviolet light can be used. In the present invention, the light irradiation energy of the UV is at 2J / cm ² or more 7J / cm ² or less, and wherein the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is 70 ° C. or higher 90 ° C. or less . By forming the cross-linked surface layer within this range, the elastic work rate of the surface layer is 52% or more and high wear resistance can be realized, and at the same time, the rate of decrease in the positive charging potential of the photoreceptor in repeated use is 50%. Thus, an electrophotographic photoreceptor capable of maintaining high image quality over a long period of time can be realized.

When the irradiation light energy of ultraviolet rays is less than ² J / cm ² , the elastic power of the surface layer is less than 52%, a sufficient cross-linked structure cannot be obtained, and high wear resistance cannot be obtained. If it exceeds 7 J / cm ² , the progress of the reaction becomes non-uniform, and the charge transport material in the crosslinked surface layer may deteriorate, unreacted groups, and reaction termination terminals may occur. In such a case, in a negatively charged electrophotographic photosensitive member due to repeated use in the electrophotographic process, when a positive potential is applied in the electrostatic transfer process, a positive charge is injected into the photosensitive member. The trapped image may cause an abnormal image such as an afterimage in the electrophotographic process after the second round. On the other hand, when the maximum temperature reached is lower than 70 ° C., the elastic power of the crosslinked surface layer is less than 52% within the range of the irradiation light energy of the ultraviolet rays, and sufficient curing cannot be obtained. When the maximum temperature reached is higher than 90 ° C., the residual potential increases, causing an abnormal image such as a decrease in density. From the viewpoint of the electrical characteristics of the photoreceptor and the curability of the crosslinked surface layer, the irradiation light energy of ultraviolet rays is 3 J / cm ² or more and 5 J / cm ² or less, and the maximum temperature of the photoreceptor surface is 70 ° C. or more and 80 ° C. or less. More preferably.

The ultraviolet irradiation light energy in the present invention is calculated from the integrated light amount and irradiation time of the ultraviolet light irradiated on the surface of the photoconductor, and the ultraviolet light amount is measured by Ushio Electric UV integrated light meter UIT-150-A and measurement probe UVD-S365. Is used to measure. The method for measuring the ultraviolet light irradiation light energy in the present invention is shown below. First, as shown in FIG. 1, the light receiving portion of the measurement probe is fixed to the central portion of the surface of the cylindrical support, and the amount of light when irradiated with ultraviolet rays while rotating the support at 30 rpm is measured. Obtain the UV light intensity profile. Next, using the ultraviolet light amount profile of FIG. 2, an integral value up to the actual ultraviolet irradiation time is calculated, and the value is used as the ultraviolet irradiation light energy. However, the measurement method is not limited to this, and any method may be used as long as a value equivalent to this can be measured. The irradiation intensity of ultraviolet rays in the present invention indicates the maximum value of the ultraviolet light amount profile in FIG. In the present invention, the irradiation light energy of ultraviolet rays is controlled by the irradiation intensity and the irradiation time. However, from the viewpoint of insufficient curing due to insufficient irradiation intensity and non-uniform reaction due to excessive irradiation intensity, 500 mW / cm ^{2 to} 1000 mW / It is preferable to make it cm ² or less.

  In the present invention, since an ultraviolet lamp is used to irradiate ultraviolet rays, the surface of the photoreceptor is heated by radiant heat generated from the ultraviolet lamp when the crosslinked surface layer is formed. The maximum temperature achieved in the present invention indicates the temperature at the end of ultraviolet irradiation when the surface of the photoreceptor is heated by the radiant heat of the ultraviolet lamp as shown in FIG.

  The initial temperature on the surface of the photoreceptor before the ultraviolet irradiation is lower than the maximum temperature and is preferably 30 ° C. or less. As long as the maximum temperature reaches the above range, any method for controlling the maximum temperature may be used. Examples of the control method of the maximum temperature reached include a method of raising the temperature only by radiant heat when the photosensitive member is irradiated with ultraviolet rays, a method of controlling the ultraviolet ray irradiation in a thermostat, a method of controlling the surface of the photosensitive member by blowing air, Control method using infrared heaters, control method using microwave irradiation, if the support is cylindrical, control the maximum temperature by flowing air inside the support, control by flowing water inside the support Method, etc. In addition, it is possible to change the cooling efficiency and the amount of heat dissipation by using materials with different thermal conductivity inside the support and using the control method shown above, and to control the maximum temperature. is there. At this time, as a material for changing the thermal conductivity, heat transfer sheets such as rubber, graphite, and silicone, and metals such as a copper plate and an iron plate processed into a support body shape can be used. Although it is not done, a thing with high adhesiveness is preferable.

  The method for measuring the surface temperature of the photoreceptor in the present invention may be any method, such as a contact thermocouple, a non-contact thermocouple, an infrared radiation thermometer, a liquid column thermometer, and a bimetal thermometer. There is a measurement method. In the present invention, as shown in FIG. 4, a cylindrical support is used, and a contact-type thermocouple is brought into contact with the surface of the photoreceptor from the non-irradiated side of the photoreceptor irradiated with ultraviolet rays. Uses a digital multimeter PC510 manufactured by Sanwa Electric Instruments Co., Ltd. and a K-type thermocouple.

The elastic power in the present invention is measured by a load-unloading test of a micro surface hardness meter using a diamond indenter. As shown in FIG. 5, the indenter is pushed at a constant load speed from the point (a) where the indenter contacts the sample (loading process), and is stationary for a certain time at the maximum displacement (b) when the set load is reached. The indenter is pulled up at the unloading speed (unloading process), and the point at which no load is finally applied to the indenter is defined as the plastic displacement (c). At this time, the curve of the indentation depth and the load obtained is recorded as shown in FIG. 6, and from this curve, the elastic deformation relative to the total work (work of plastic deformation + work of elastic deformation) performed by the indenter on the surface layer is recorded. The elastic work rate of the present invention is obtained by determining the work rate. In other words, this is expressed as follows:
Elastic power (%)
= Work of elastic deformation x 100 / (Work of plastic deformation + Work of elastic deformation)

  In the present invention, measurement is performed under the condition of a set load of 9.8 mN using a Fisher Instruments H-100 (manufactured by Fischer Instruments) and a Vickers indenter. It may be a value.

  The rate of decrease of the positive charging potential in the present invention is calculated from the charging potential before and after electrostatic fatigue. The positive charging potential in the present invention is measured by using a photoconductor potential simulation apparatus for a copying machine described in Japanese Patent Application Laid-Open No. 60-1000016. The surface potential at this time is measured to obtain a positive charging potential, but it may be a value measured by any device having equivalent performance. In the present invention, the electrostatic fatigue is repeated for 24 hours on the electrophotographic photosensitive member only by charging and discharging processes, and this is regarded as electrostatic fatigue. In the present invention, the initial dark portion potential is set to -800 V using only a Ricoh imagio MF7070 machine with the developing unit and transfer belt removed, and only the charging and discharging processes are repeated for 24 hours. Any method may be used as long as it is electrostatic fatigue.

Since the film thickness of the surface layer of the present invention varies depending on the layer structure of the photoreceptor in which the surface layer is used, it is described in accordance with the following description of the layer structure.
<About the layer structure of the electrophotographic photoreceptor>
The electrophotographic photosensitive member used in the present invention will be described with reference to the drawings.
FIG. 7 is a sectional view showing the electrophotographic photosensitive member of the present invention. FIG. 7A shows a photoconductor in which a cross-linked surface layer is laminated on a photoconductor having a single layer structure in which a photoconductive layer (32) having a charge generation function and a charge transport function is provided on a conductive support (31). It is. FIG. 7B shows a photosensitive structure having a laminate structure in which a charge generation layer (33) having a charge generation function and a charge transport layer (34) having a charge transport material function are laminated on a conductive support (31). This is a photoreceptor in which a crosslinked surface layer is laminated on the body.

<About conductive support>
Examples of the conductive support (31) include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium by vapor deposition or sputtering, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. After conversion, a tube that has been subjected to surface treatment such as cutting, superfinishing, or polishing can be used. Further, an endless nickel belt and an endless stainless steel belt disclosed in Japanese Patent Application Laid-Open No. 52-36016 can be used as the conductive support (31).

In addition, the conductive support dispersed in a suitable binder resin and coated on the support can also be used as the conductive support (31) of the present invention.
Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Can be mentioned. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support (31) of the present invention.

<About photosensitive layer>
Next, the photosensitive layer will be described. The photosensitive layer may have a laminated structure or a single layer structure.
In the case of a laminated structure, the photosensitive layer is composed of a charge generation layer having a charge generation function and a charge transport layer having a charge transport function. In the case of a single layer structure, the photosensitive layer is a layer having a charge generation function and a charge transport function at the same time.

Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.
<Photosensitive layer comprising a charge generation layer and a charge transport layer>
(Charge generation layer)
The charge generation layer (33) is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.

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

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, 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.

  The binder resin used as necessary for the charge generation layer (33) includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-. Examples thereof include vinyl carbazole and polyacrylamide. These binder resins can be used alone or as a mixture of two or more. In addition to the binder resin described above as a binder resin for the charge generation layer, a polymer charge transport material having a charge transport function, such as an arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, etc. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.

  Specific examples of the former include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559, Japanese Unexamined Patent Publication Nos. 04-011627, 04-175337, 04-183719, 04-2225014, 04-230767, 04-320420, 05 -232727, JP-A 05-310904, JP-A 06-234836, JP-A 06-234837, JP-A 06-234838, JP-A 06-234839, JP-A 06-234840. No. 1, JP-A 06-234841, JP-A 06-239049, Japanese Unexamined Patent Publication Nos. 06-236050, 06-236051, 06-295077, 07-0756374, 08-176293, 08-208820, 08 No. -21640, JP 08-253568, JP 08-269183, JP 09-062019, JP 09-043883, JP 09-71642, JP 09-87376. JP-A 09-104746, JP-A 09-110974, JP-A 09-110976, JP-A 09-157378, JP-A 09-221544, JP-A 09-227669. JP 09-235367 A, JP 09-241369 A Charge transporting polymer materials described in JP 09-268226 A, JP 09-272735 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Can be mentioned.

  Specific examples of the latter include polysilylene polymers described in, for example, JP-A No. 63-285552, JP-A No. 05-19497, JP-A No. 05-70595, JP-A No. 10-73944, and the like. Illustrated.

The charge generation layer (33) may contain a low molecular charge transport material.
Low molecular charge transport materials that can be used in combination with the charge generation layer (33) include hole transport materials and electron transport materials.
Examples of the electron transport material include chloranil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. As hole transport materials, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls Other known materials such as methane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.

As a method for forming the charge generation layer (33), a vacuum thin film preparation method and a casting method from a solution dispersion system can be largely mentioned.
As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.

In addition, in order to provide a charge generation layer by the casting method described later, if necessary, the inorganic or organic charge generation material together with a binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. Can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. . Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The 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 charge transport layer)
The charge transport layer (34) is a layer having a charge transport function, and a charge transport material having a charge transport function and a binder resin are dissolved or dispersed in an appropriate solvent, and this is applied onto the charge generation layer (33). It is formed by drying. A coating solution containing the radically polymerizable composition of the present invention is applied on this, and crosslinked and cured by the light energy of ultraviolet rays.

  As the charge transport material, the electron transport material, hole transport material and polymer charge transport material described in the charge generation layer (33) can be used. As described above, the use of the polymer charge transport material can reduce the solubility of the lower layer when the surface layer is applied, and is particularly useful.

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it can be used alone or in combination with a binder resin.
As the solvent used for coating the charge transport layer, the same solvent as that used for the charge generation layer can be used. These solvents may be used alone or in combination of two or more. The charge transport layer can be formed by the same coating method as that for the charge generation layer (33).

If necessary, a plasticizer and a leveling agent can be added.
As the plasticizer that can be used in combination with the charge transport layer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 0 with respect to 100 parts by weight of the binder resin. About 30 parts by weight is appropriate.

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. The amount used is a binder resin. About 0 to 1 part by weight is appropriate for 100 parts by weight.
The thickness of the charge transport layer is suitably about 5 to 40 μm, preferably about 10 to 30 μm.

  As described in the above cross-linked surface layer preparation method, the cross-linked surface layer is coated with a coating solution containing the radical polymerizable composition of the present invention on the charge transport layer and then cured by ultraviolet irradiation light energy. And a crosslinked surface layer is formed. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. If the thickness is less than 1 μm, the durability varies due to uneven film thickness. If the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased, and the reproducibility of the image is reduced due to the diffusion of charges.

<Single photosensitive layer>
The photosensitive layer (32) having a single layer structure is a layer having a charge generation function and a charge transport function at the same time, and the photosensitive layer comprises a charge generation substance having a charge generation function, a charge transport substance having a charge transport function, and a binder resin. It can be formed by dissolving or dispersing in a suitable solvent, coating and drying. Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the charge generation material dispersion method, the charge generation material, the charge transport material, the plasticizer, and the leveling agent may be the same as those already described in the charge generation layer (33) and the charge transport layer (34). As the binder resin, in addition to the binder resin previously mentioned in the section of the charge transport layer (34), the binder resin mentioned in the charge generation layer (33) may be mixed and used. In addition, the polymer charge transport materials listed above can also be used, which is useful in that contamination of the lower layer photosensitive layer composition into the crosslinked surface layer can be reduced. The film thickness of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.

The crosslinked surface layer is coated with a coating solution containing the radically polymerizable composition of the present invention on the photosensitive layer as described above, dried as necessary, and cured by irradiation light energy of ultraviolet rays. Form. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness.
The charge generation material contained in the photosensitive layer having a single layer structure is preferably 1 to 30% by weight based on the total amount of the photosensitive layer, the binder resin contained in the photosensitive layer is 20 to 80% by weight of the total amount, and the charge transport material is 10 to 70% by weight is preferably used.

<About the intermediate layer>
In the photoreceptor of the present invention, since the crosslinked surface layer is provided on the photosensitive layer, it is possible to provide an intermediate layer for the purpose of suppressing mixing of lower layer components into the crosslinked surface layer or improving adhesion with the lower layer. . This intermediate layer prevents inhibition of the curing reaction and unevenness of the crosslinked surface layer caused by mixing of the lower photosensitive layer composition in the outermost surface layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the lower photosensitive layer and the surface cross-linked layer.

  In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method is employed as described above. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

<About the undercoat layer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support (31) 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 anodic oxidation, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

<Addition of antioxidant to each layer>
In the present invention, in order to improve environmental resistance, in order to prevent a decrease in sensitivity and an increase in residual potential, a surface cross-linked layer, a photosensitive layer, a charge generation layer, a charge transport layer, an undercoat layer, an intermediate layer An antioxidant can be added to each layer such as a layer.
The following are mentioned as antioxidant which can be used for this invention.

(Phenolic compounds)
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-tert-butylphenol), 4, 4'-thiobis- (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2-methyl-4 -Hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid ] Cryol ester, tocopherols and the like.

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

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

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

<Image Forming Method and Apparatus>
Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
The image forming method and the image forming apparatus of the present invention use a photoconductor having a smooth charge transporting surface cross-linked layer. For example, at least after the photoconductor is charged, exposed to an image, and developed, an image carrier (transfer) An image forming method and an image forming apparatus including a process of transferring a toner image onto paper (paper), fixing, and cleaning the surface of a photoreceptor.
In some cases, an image forming method or the like in which an electrostatic latent image is directly transferred to a transfer member and developed does not necessarily have the above-described process arranged on a photosensitive member.

  FIG. 8 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.

  In particular, the configuration of the present invention is effective when a charging unit such as a contact charging method or a non-contact proximity arrangement charging method is used in which the photosensitive composition is decomposed by proximity discharge from the charging unit. Here, the contact charging method is a charging method in which a charging roller, a charging brush, a charging blade, or the like is in direct contact with the photosensitive member. On the other hand, the proximity charging method is, for example, a type in which the charging roller is arranged in a non-contact state so as to have a gap of 200 μm or less between the surface of the photoreceptor and the charging means. If this gap is too large, the charging tends to become unstable, and if it is too small, the surface of the charging member may be contaminated when toner remaining on the photoreceptor exists. is there. Accordingly, the gap is suitably 10 to 200 μm, preferably 10 to 100 μm.

  Next, the image exposure unit (5) is used to form an electrostatic latent image on the uniformly charged photoreceptor (1). As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Next, the developing unit (6) is used to visualize the electrostatic latent image formed on the photoreceptor (1). Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. 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. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp (2) and a charge removal charger are used, and the exposure light source and the charging means can be used respectively.
In addition, known processes can be used for reading, feeding, fixing, paper discharge and the like that are not close to the photoconductor.
The present invention is an image forming method and an image forming apparatus using the electrophotographic photoreceptor according to the present invention for such image forming means.

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

  Referring to the image forming process by the apparatus illustrated in FIG. 9, 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.

The present invention provides a process cartridge for an image forming apparatus in which a photosensitive member having a smooth charge transporting surface cross-linked layer and at least one of charging, developing, transferring, cleaning, and neutralizing means are integrated.
As is apparent from the above description, the electrophotographic photoreceptor of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

<Synthesis Example of Radical Polymerizable Compound Having Charge Transporting Structure>
The compound having a charge transporting structure in the present invention is synthesized, for example, by the method described in Japanese Patent No. 3164426. An example of this is shown below.
Synthesis Example of Radical Polymerizable Compound Having Triarylamine Structure (i) Synthesis of Hydroxy Group-Substituted Triarylamine Compound (Structure Formula B below) Methoxy group-substituted triarylamine compound (Structure Formula A below) 113.85 g (0. 3 mol) and 138 g (0.92 mol) of sodium iodide were added 240 ml of sulfolane and heated to 60 ° C. in a nitrogen stream. In this liquid, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%, melting point: 64.0-66.0 ° C.) of the white crystal of the following structural formula B was obtained.

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

Synthesis Example of Acrylic Acid Ester Compound (i) Preparation of Diethyl 2-Hydroxybenzyl Phosphonate Into a reaction vessel equipped with a stirrer, thermometer and dropping funnel, 38.4 g of 2-hydroxybenzyl alcohol (manufactured by Tokyo Chemical Industry), o -Xylene 80ml was put, 62.8g of triethyl phosphite (product made from Tokyo Chemicals) was dripped slowly at 80 degreeC under nitrogen stream, and also reaction was performed at the same temperature for 1 hour. Thereafter, the produced ethanol, the solvent o-xylene, and unreacted triethyl phosphite were removed by distillation under reduced pressure to obtain 66 g of diethyl 2-hydroxybenzylphosphonate. (Boiling point 120.0 ° C./1.5 mmHg) (yield 90%)

(Ii) Preparation of 2-hydroxy-4 ′-(N, N-bis (4-methylphenyl) amino) stilbene Into a reaction vessel equipped with a stirrer, thermometer and dropping funnel, 14.8 g of potassium tert-butoxide. A solution of 9.90 g of diethyl 2-hydroxybenzylphosphonate and 5.44 g of 4- (N, N-bis (4-methylphenyl) amino) benzaldehyde in tetrahydrofuran was added under a nitrogen stream. The solution was slowly added dropwise at room temperature, and then reacted at the same temperature for 2 hours. Thereafter, water was added under water cooling, and then 2N hydrochloric acid aqueous solution was added for acidification. Tetrahydrofuran was removed by an evaporator, and the crude product was extracted with toluene. The toluene phase was washed with water, an aqueous sodium hydrogen carbonate solution and saturated brine in this order, and dehydrated by adding magnesium sulfate. After filtration, toluene was removed to obtain an oily crude product, which was further purified with silica gel and then crystallized in hexane to give 5.09 g of 2-hydroxy-4 ′-(N, N-bis). (4-Methylphenyl) amino) stilbene was obtained. (Yield 72%, melting point 136.0-138.0 ° C.)

(Iii) Preparation of 4 ′-(N, N-bis (4-methylphenyl) amino) stilben-2-yl acrylate In a reaction vessel equipped with a stirrer, a thermometer and a dropping funnel, 2-hydroxy-4′- (N, N-bis (4-methylphenyl) amino) stilbene (14.9 g), tetrahydrofuran (100 ml), 12% strength aqueous sodium hydroxide solution (21.5 g) were added, and acrylic acid chloride (5.17 g) was added at 5 ° C. under a nitrogen stream. It was added dropwise over 30 minutes. Then, it was made to react at the same temperature for 3 hours. The reaction solution was poured into water, extracted with toluene, concentrated and subjected to column purification with silica gel. The obtained crude product was recrystallized with ethanol, and yellow needle-like 4 ′-(N, N-bis (4-methylphenyl) amino) stilben-2-yl acrylate (Exemplary Compound NO. 109) 13. 5 g was obtained. (Yield 79.8%, melting point 104.1-105.2 ° C.) Elemental analysis results are shown below.

以上の様に、２−ヒドロキシベンジルホスホン酸エステル誘導体と種々のアミノ置換ベンズアルデヒド誘導体を反応させることにより数多くの２−ヒドロキシスチルベン誘導体を合成し、そのアクリル化またはメタクリル化を行なう事で種々のアクリル酸エステル化合物を合成することができる。

As described above, a number of 2-hydroxystilbene derivatives are synthesized by reacting 2-hydroxybenzylphosphonic acid ester derivatives with various amino-substituted benzaldehyde derivatives. An ester compound can be synthesized.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Note that “parts” used in the examples all represent parts by weight.

Example 1
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 φ100 mm aluminum cylinder in sequence, an undercoat layer of 3.0 μm A 0.2 μm charge generation layer and a 20 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 & Chemicals, Inc.)
Titanium oxide: 40 parts Methyl ethyl ketone: 50 parts

[Coating liquid for charge generation layer]
Titanyl phthalocyanine pigment of the following structural formula (I): 15 parts Polyvinyl butyral (BX-1: manufactured by Sekisui Chemical): 10 parts 2-butanone: 280 parts

[Coating fluid for charge transport layer]
Bisphenol Z polycarbonate: 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals)
Low molecular charge transport material of the following structural formula (II): 7 parts Tetrahydrofuran: 100 parts 1% silicone oil in tetrahydrofuran: 0.2 parts (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

A coating solution for a crosslinked surface layer having the following constitution was spray-coated on the charge transport layer. After spray coating, a UV lamp system manufactured by Fusion was used as the UV irradiation device, and UV irradiation was performed while rotating the support at 30 rpm. UV irradiation using a metal halide lamp, the distance of the ultraviolet lamp and the surface of the photosensitive body 50 mm, 800 mW / cm ² irradiation intensity, irradiation time 40 sec, 3.6 J / cm ² irradiation light energy, when the ultraviolet irradiation The surface temperature of the photosensitive member was set such that the initial temperature of the photosensitive member surface was 20 ° C. and the maximum temperature reached 72 ° C. by flowing 20 ° C. air through the support at a flow rate of 0.3 m ³ / min. After the ultraviolet irradiation, drying was performed at 90 ° C. for 10 minutes, and a 5 μm cross-linked surface layer was provided to obtain the electrophotographic photoreceptor of the present invention.

[Coating liquid for cross-linked surface layer]
Radical polymerizable compound having charge transporting structure: 10 parts Exemplified compound NO. 54 (Molecular weight: 419, number of functional groups: 1)
Trifunctional or higher radical polymerizable monomer having no charge transporting structure: 10 parts Trimethylolpropane triacrylate (manufactured by Nippon Kayaku, KAYARAD TMPTA, molecular weight: 296, number of functional groups: trifunctional)
Photopolymerization initiator: 1 part Irgacure 184 (manufactured by Nippon Kayaku, molecular weight: 204)
Solvent: 120 parts Tetrahydrofuran (boiling point: 66 ° C., saturated vapor pressure: 176 mmHG / 25 ° C.)

Example 2
In Example 1, all except that the temperature of the air flowing inside the support was changed to 30 ° C., the flow rate was changed to 0.2 m ³ / min, the initial temperature of the photoreceptor surface was set to 30 ° C., and the maximum reached temperature was set to 87 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

ジペンタエリスリトールカプロラクトン変性ヘキサアクリレート
（日本化薬製、ＫＡＹＡＲＡＤ ＤＰＣＡ−６０）官能基数：６官能 Example 3
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Also, the irradiation time under the ultraviolet irradiation conditions is changed to 60 seconds, the irradiation light energy is changed to 5.5 J / cm ² , the temperature of the air flowing inside the support is changed to 20 ° C., and the flow rate is changed to 0.3 m ³ / min. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial temperature on the surface of the photosensitive member was 20 ° C. and the maximum temperature reached on the surface of the photosensitive member was 81 ° C.

Dipentaerythritol caprolactone-modified hexaacrylate (manufactured by Nippon Kayaku, KAYARAD DPCA-60) Number of functional groups: 6 functions

Example 4
In Example 1, the irradiation time under the ultraviolet irradiation conditions was changed to 70 seconds, the irradiation light energy was changed to 6.4 J / cm ² , and a 1 mm rubber sheet (manufactured by Maruyoshi Polymer) was brought into close contact with the inner surface of the support, and the water at 30 ° C. Was supplied at a flow rate of 3 L / min, and an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial temperature on the surface of the photosensitive member was 30 ° C. and the maximum temperature reached 74 ° C.

ジペンタエリスリトールヘキサアクリレート
（ヘキサアクリレート（ａ＝５、ｂ＝１）とペンタアクリレート（ａ＝６、ｂ＝０）の質量比１：１混合物）
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＨＡ）
官能基数：５官能化合物と６官能化合物（質量比１：１） Example 5
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Also, the irradiation time under the ultraviolet irradiation condition is changed to 70 seconds, the irradiation light energy is changed to 6.4 J / cm ² , a 3 mm rubber sheet (made by Maruyoshi polymer) is brought into close contact with the inner surface of the support, and 30 ° C. water is supplied at a flow rate of 3 L. The electrophotographic photosensitive member was manufactured in the same manner as in Example 1 except that the initial temperature of the photosensitive member surface was 30 ° C. and the maximum temperature reached 86 ° C.

Dipentaerythritol hexaacrylate (mass ratio 1: 1 mixture of hexaacrylate (a = 5, b = 1) and pentaacrylate (a = 6, b = 0))
(Nippon Kayaku, KAYARAD DPHA)
Number of functional groups: pentafunctional compound and hexafunctional compound (mass ratio 1: 1)

ジペンタエリスリトールヘキサアクリレート（ヘキサアクリレート（ａ＝５、ｂ＝１）とペンタアクリレート（ａ＝６、ｂ＝０）の質量比１：１混合物）
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＨＡ）
官能基数：５官能化合物と６官能化合物（質量比１：１） Example 6
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Further, the irradiation time under the ultraviolet irradiation condition is changed to 50 seconds, the irradiation light energy is changed to 4.5 J / cm ² , the temperature of the air flowing inside the support is changed to 30 ° C., and the flow rate is changed to 0.3 m ³ / min. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial temperature of the surface of the photosensitive member was 30 ° C. and the maximum temperature reached 88 ° C.

Dipentaerythritol hexaacrylate (mass ratio 1: 1 mixture of hexaacrylate (a = 5, b = 1) and pentaacrylate (a = 6, b = 0))
(Nippon Kayaku, KAYARAD DPHA)
Number of functional groups: pentafunctional compound and hexafunctional compound (mass ratio 1: 1)

Example 7
In Example 1, the irradiation intensity under the ultraviolet irradiation condition was changed to 1000 mW / cm ² , the irradiation time was changed to 30 seconds, the irradiation light energy was changed to 3.4 J / cm ² , and water at 40 ° C. was flowed into the support at a flow rate of 1 L / min. The electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial temperature on the surface of the photosensitive member was 40 ° C. and the maximum temperature reached 73 ° C.

カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＣＡ−１２０）
官能基数：６官能 Example 8
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Further, the irradiation intensity under the ultraviolet irradiation condition was changed to 500 mW / cm ² , the irradiation time was changed to 60 seconds, and the irradiation light energy was changed to 3.4 J / cm ² . In addition, the initial temperature of the surface of the photoconductor is set to 15 ° C., air is not allowed to flow inside the support, and a far infrared heater FIH-1005A (manufactured by Nippon Heat Transfer Co., Ltd.) is installed at a position 10 cm from the non-irradiated surface of the photoconductor An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the maximum temperature of the photosensitive member was 90 ° C. by raising the temperature simultaneously with the irradiation.

Caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120)
Functional group number: 6 functions

Example 9
In Example 1, the irradiation intensity under the ultraviolet irradiation conditions is 300 mW / cm ² , the irradiation time is 100 seconds, the irradiation light energy is 3.4 J / cm ² , the temperature of the air flowing inside the support is 30 ° C., the flow rate is 0. The electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature was changed to 2 m ³ / min and the initial temperature of the photosensitive member surface was 30 ° C. and the maximum temperature reached 80 ° C.

Example 10
In Example 1, the radical polymerizable monomer having a charge transporting structure was converted into the exemplified compound NO. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the molecular weight was changed to 109 (molecular weight: 445, functional group number: 1). At this time, the maximum temperature reached was 74 ° C.

カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＣＡ−１２０）
官能基数：６官能 Example 11
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Further, the distance between the ultraviolet lamp and the surface of the photosensitive member was 100 mm, and the irradiation time was 80 seconds. At this time, the irradiation intensity was 400 mW / cm ² and the irradiation light energy was 3.6 J / cm ² . Also, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature of the air flowing inside the support was changed to 30 ° C. and the flow rate was changed to 0.2 m ³ / min, and the maximum temperature reached 71 ° C.

Caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120)
Functional group number: 6 functions

Comparative Example 1
In Example 1, the irradiation time under the ultraviolet irradiation conditions was changed to 20 seconds, the irradiation light energy was changed to 1.8 J / cm ² , air was not passed through the support, and the maximum temperature reached on the surface of the photosensitive member was 74 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that.

ジペンタエリスリトールカプロラクトン変性ヘキサアクリレート
（日本化薬製、ＫＡＹＡＲＡＤ ＤＰＣＡ−６０）
官能基数：６官能 Comparative Example 2
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Further, the irradiation time under the ultraviolet irradiation condition is changed to 20 seconds, the irradiation light energy is changed to 1.8 J / cm ² , water at 60 ° C. is flowed at 1 L / min inside the support, and the initial temperature of the surface of the photosensitive member is 60 ° C. In addition, far-infrared heater FIH-1005A (manufactured by Nippon Heat Transfer Co., Ltd.) is installed at a position 10 cm from the non-irradiated surface of the photoconductor. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

Dipentaerythritol caprolactone-modified hexaacrylate (manufactured by Nippon Kayaku, KAYARAD DPCA-60)
Functional group number: 6 functions

Comparative Example 3
In Example 1, the irradiation time under ultraviolet irradiation conditions was changed to 40 seconds, the irradiation light energy was changed to 3.6 J / cm ² , a 3 mm rubber sheet was brought into close contact with the inner surface of the support, and 30 ° C. water was supplied at 1 L / min. The initial temperature on the surface of the photoconductor is set to 30 ° C., and a far infrared heater FIH-1005A (manufactured by Nippon Heat Transfer Co., Ltd.) is installed at a position 10 cm from the non-irradiated surface of the photoconductor. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the maximum temperature reached 103 ° C.

Comparative Example 4
In Example 1, the irradiation time under the ultraviolet irradiation condition was changed to 70 seconds, the irradiation light energy was changed to 6.4 J / cm ² , and air at 10 ° C. was flown at 2 m ³ / min inside the support to obtain the initial surface of the photoreceptor. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature was 10 ° C. and the maximum temperature reached 40 ° C.

ジペンタエリスリトールヘキサアクリレート（ヘキサアクリレート（ａ＝５、ｂ＝１）とペンタアクリレート（ａ＝６、ｂ＝０）の質量比１：１混合物）
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＨＡ）
官能基数：５官能化合物と６官能化合物（質量比１：１） Comparative Example 5
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. In addition, the irradiation time under the ultraviolet irradiation conditions was changed to 70 seconds, the irradiation light energy was changed to 6.4 J / cm ² , air was not flowed into the support, and the maximum temperature reached on the surface of the photosensitive member was 98 ° C. An electrophotographic photoreceptor was produced in the same manner as in Example 1.

Dipentaerythritol hexaacrylate (mass ratio 1: 1 mixture of hexaacrylate (a = 5, b = 1) and pentaacrylate (a = 6, b = 0))
(Nippon Kayaku, KAYARAD DPHA)
Number of functional groups: pentafunctional compound and hexafunctional compound (mass ratio 1: 1)

Comparative Example 6
In Example 1, the irradiation time under ultraviolet irradiation conditions was changed to 100 seconds, the irradiation light energy was changed to 9.1 J / cm ² , a 2 mm rubber sheet was brought into close contact with the inner surface of the support, and 30 ° C. water was flowed at a flow rate of 5 L / min. The electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial temperature on the surface of the photosensitive member was 30 ° C. and the maximum temperature reached 55 ° C.

カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（日本化薬社製、ＫＡＹＡＲＡＤ ＤＰＣＡ−１２０）
官能基数：６官能 Comparative Example 7
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following material. Further, the irradiation time under the ultraviolet irradiation condition is changed to 150 seconds, the irradiation light energy is changed to 13.6 J / cm ² , water at 20 ° C. is flowed into the support at a flow rate of 6 L / min, and the initial temperature of the surface of the photosensitive member is 20 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the temperature reached 30 ° C. and the maximum temperature reached 30 ° C.

Caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPCA-120)
Functional group number: 6 functions

Comparative Example 8
The charge transport layer was prepared in the same manner as in Example 1. On this charge transport layer, a crosslinked surface layer was formed according to Example 9 described in JP-A-2005-227761 to produce an electrophotographic photosensitive member. At this time, the irradiation light energy was 1.1 J / cm ² and the maximum temperature reached 38 ° C.

Comparative Example 9
The charge transport layer was prepared in the same manner as in Example 1. On this charge transport layer, a surface layer was formed according to Example 1 described in JP-A No. 2001-125297 to prepare an electrophotographic photosensitive member. At this time, the irradiation light energy was 3.4 J / cm ² and the maximum temperature reached 27 ° C.

Comparative Example 10
The charge transport layer was prepared in the same manner as in Example 1. On this charge transport layer, a surface layer was formed in accordance with the examples described in JP-A-59-162559 to prepare an electrophotographic photoreceptor. However, the ultraviolet irradiation intensity was 1000 mW / cm ² , the irradiation light energy was 17.0 J / cm ² , and the maximum temperature reached was 63 ° C.

Comparative Example 11
In Example 1, the cross-linked surface layer was not provided, and the thickness of the charge transport layer was 25 μm to prepare an electrophotographic photosensitive member.

２官能アクリレート：日本化薬製、ＫＡＹＡＲＡＤ ＮＰＧＤＡ
官能基数：２官能 Comparative Example 12
In Example 1, all the same procedures as in Example 1 except that the trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure contained in the crosslinked surface layer coating solution was changed to the following materials. The body was made. At this time, the irradiation light energy was 3.6 J / cm ² and the maximum temperature reached 73 ° C. The following materials are bifunctional groups and are not included in the trifunctional or higher functional radical polymerizable monomer having no charge transport structure.

Bifunctional acrylate: Nippon Kayaku, KAYARAD NPGDA
Functional group number: 2 functions

Comparative Example 13
Example 1 is the same as Example 1 except that the radical polymerizable monomer having a charge transporting structure is not added and the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure is 20 parts. Thus, an electrophotographic photosensitive member was produced. At this time, the irradiation light energy was 3.6 J / cm ² and the maximum temperature reached 72 ° C.

Comparative Example 14
Example 1 is the same as Example 1 except that no trifunctional or higher-functional radical polymerizable monomer having no charge transporting structure is added and 20 parts of the radical polymerizable monomer having a charge transporting structure is used. Thus, an electrophotographic photosensitive member was produced. At this time, the irradiation light energy was 3.6 J / cm ² and the maximum temperature reached 71 ° C.

The test method evaluated below is shown.
<Curing test>
A solubility test for an organic solvent is performed as an index of the curing progress of the crosslinked surface layer. One drop of tetrahydrofuran is dropped on the photoreceptor, and the change in the surface shape after natural drying is visually observed. In the case where the curing has not progressed, a part of the surface is dissolved, and ring-shaped unevenness and cloudiness occur.

<Electrostatic fatigue method>
Installed the electrophotographic photosensitive member in a process cartridge for an electrophotographic apparatus, and using a Ricoh imagio MF7070 remodeling machine with the developing unit and transfer belt removed, the initial dark portion potential was set to -800 V, and only charging and static elimination processes Was repeated for 24 hours.
<Electric potential evaluation>
The prepared electrophotographic photosensitive member is mounted on the apparatus disclosed in Japanese Patent Laid-Open No. 60-1000016, rotated at 1700 rpm, and subjected to +6.0 kV corona charging for 20 seconds, and the surface potential Vm at this time is measured. did. The evaluation was performed before and after electrostatic fatigue. The rate of decrease in positive charging potential is the ratio of the difference between Vm before and after electrostatic fatigue to Vm before electrostatic fatigue.
<Electric potential and image evaluation>
The photosensitive member was mounted on a process cartridge for an electrophotographic apparatus, the initial dark portion potential was set to -800 V using Ricoh's imgio Neo 1050 Pro, and the potential evaluation when the image was output and the quality evaluation of the output image were performed. . Evaluation was performed before and after electrostatic fatigue.

<Actual paper passing test>
Attach the photoconductor to a process cartridge for an electrophotographic apparatus, set the dark area potential to -800 V using Ricoh's imgio Neo 1050 Pro, pass 100,000 sheets, and then measure the wear amount of the surface layer did. The amount of wear is the difference in film thickness before and after the actual machine passes, and the film thickness was measured by an eddy current method using a multi-system film thickness meter manufactured by Fischerscope.

この結果から架橋表面層を設けていない比較例１１、アクリル官能基数が少ない比較例１２、３官能以上のラジカル重合性官能基を有するモノマーを含有していない比較例１４において表面がテトラヒドロフランに溶解した。この結果からこれらの比較例については３次元架橋が進んでおらず、高い耐摩耗性が得られない。 The result of the sclerosis | hardenability test of Examples 1-11 and Comparative Examples 1-14 is shown at the following table.

From this result, the surface was dissolved in tetrahydrofuran in Comparative Example 11 in which no cross-linked surface layer was provided, Comparative Example 12 in which the number of acrylic functional groups was small, and Comparative Example 14 in which a monomer having a radical polymerizable functional group of 3 or more functions was not contained. . From these results, in these comparative examples, the three-dimensional crosslinking does not proceed and high wear resistance cannot be obtained.

この結果から、３官能以上のラジカル重合性モノマーを有し、紫外線の照射光エネルギーが２Ｊ／ｃｍ²以上でかつ、最高到達温度が７０℃以上の範囲である実施例１〜１１および比較例３、５、１３は、弾性仕事率が５２％以上であり、十分に架橋した架橋表面層が形成された。比較例６、７は最高到達温度が７０℃未満であるが、照射光エネルギーが高いため、十分な架橋構造が形成された。また照射光エネルギーが７Ｊ／ｃｍ²以下である実施例１〜１１および比較例１〜５、８〜９、１２〜１４は、正の帯電電位の低下率が５０％以下であり、正帯電性の低下を低減した感光体が実現されている。紫外線照射がなく、架橋表面層を形成していない比較例１１においても正帯電性の低下は５０％以下であった。 The results of measuring the elastic power and the reduction rate of the positive charging potential in Examples 1 to 11 and Comparative Examples 1 to 14 are shown in the following table.

From these results, Examples 1 to 11 and Comparative Example 3 having a radical polymerizable monomer having 3 or more functional groups, an irradiation light energy of ultraviolet rays of ² J / cm ² or more, and a maximum attained temperature of 70 ° C. or more. Nos. 5 and 13 had an elastic power of 52% or more, and a sufficiently crosslinked cross-linked surface layer was formed. In Comparative Examples 6 and 7, the maximum temperature reached was less than 70 ° C., but since the irradiation light energy was high, a sufficient crosslinked structure was formed. In Examples 1 to 11 and Comparative Examples 1 to 5, 8 to 9, and 12 to 14 in which the irradiation light energy is 7 J / cm ² or less, the rate of decrease in the positive charging potential is 50% or less, and the positive chargeability Thus, a photoconductor with reduced decrease in the size has been realized. Even in Comparative Example 11 where there was no ultraviolet irradiation and no crosslinked surface layer was formed, the decrease in positive chargeability was 50% or less.

この結果から、最高到達温度が９０℃より高かった比較例３、５では明部電位が高く濃度低下が発生した。表面層に電荷輸送機能がない比較例１０、１３でも、明部電位が高くなり、濃度低下が発生したが、表面層に電荷輸送機能がない比較例９は、膜厚が３μｍと薄いため明部電位の上昇は見られなかった。また、紫外線の照射エネルギーが７Ｊ／ｃｍ²より高く、正の帯電電位の低下率が５０％以上であった比較例６、７では静電疲労後に残像が発生した。紫外線の照射光エネルギーが７Ｊ／ｃｍ²以下であり、紫外線の照射時における感光体表面の最高到達温度が９０℃以下である実施例１〜１１、比較例１、２、４、８、９、１１、１２、１４の感光体では、静電疲労露後も残像や濃度低下などの異常画像は発生せず、高画質の画像出力が得られている。 Next, with respect to Examples 1 to 11 and Comparative Examples 1 to 14, potential and image evaluation results before and after the electrostatic fatigue are shown in the following table.

From these results, in Comparative Examples 3 and 5 in which the maximum reached temperature was higher than 90 ° C., the bright portion potential was high and the concentration decreased. Even in Comparative Examples 10 and 13 in which the surface layer does not have a charge transport function, the bright portion potential increased and the concentration decreased, but in Comparative Example 9 in which the surface layer did not have a charge transport function, the thickness was as thin as 3 μm. There was no increase in part potential. In Comparative Examples 6 and 7, in which the irradiation energy of ultraviolet rays was higher than 7 J / cm ² and the rate of decrease in the positive charging potential was 50% or more, afterimages were generated after electrostatic fatigue. Examples 1 to 11 and Comparative Examples 1, 2, 4, 8, 9, wherein the irradiation light energy of ultraviolet rays is 7 J / cm ² or less, and the maximum temperature reached on the surface of the photoreceptor when irradiated with ultraviolet rays is 90 ° C. or less. On the photoconductors 11, 12, and 14, abnormal images such as afterimages and density reduction do not occur after electrostatic fatigue exposure, and high-quality image output is obtained.

弾性仕事率が５２％未満であった比較例１、２、４、８、９、１１、１２、１４では、摩耗量が多く、高い耐久性は期待できない。一方弾性仕事率が５２％以上であった実施例１〜１１においては、摩耗量が少なく、高い耐摩耗性と長期に渡る高品質な画像の維持が実現可能である。 Next, with respect to Examples 1 to 11 and Comparative Examples 1, 2, 4, 8, 9, 11, 12, and 14, the amount of wear was evaluated when 100,000 sheets were passed with RICOH Imagio Neo 1050. The results are shown in the table below.

In Comparative Examples 1, 2, 4, 8, 9, 11, 12, and 14 in which the elastic power is less than 52%, the wear amount is large, and high durability cannot be expected. On the other hand, in Examples 1 to 11 in which the elastic power is 52% or more, the wear amount is small, and high wear resistance and maintenance of high-quality images over a long period can be realized.

Therefore, in the electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on the conductive support of the present invention, the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, the light energy at the ultraviolet rays, 2J / cm ² or more 7J / cm ² or less, the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is less than 90 ° C. 70 ° C. or higher Due to the characteristics, an electrophotographic photosensitive member having high wear resistance and stable electrical characteristics over a long period of time and capable of maintaining a high-quality image has been realized. It has also been clarified that the method for producing a photoreceptor of the present invention, the image forming process using the photoreceptor, the image forming apparatus and the process cartridge for the image forming apparatus have high performance and high reliability.

It is a figure explaining the measuring method of ultraviolet irradiation light energy. It is the ultraviolet light quantity profile obtained by measuring the light quantity of the light-receiving part of FIG. It is a graph which shows the temperature change of the photoreceptor surface. It is a figure explaining the measuring method of a photoreceptor surface temperature. It is a figure which shows the measuring method of an elastic work rate. It is a graph which shows the relationship between the indentation depth and load obtained in order to measure an elastic work rate. 1 is a cross-sectional view illustrating an electrophotographic photosensitive member of the present invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. It is the schematic which shows an example of the process cartridge of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 5 Image exposure part 6 Developing unit 7 Charger before transfer 9 Transferr 10 Transfer charger 11 Separation charger 12 Separation nail 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 101 Photoreceptor 102 Charging means 104 Developing means 105 Transfer body 106 Transfer means 107 Cleaning means

Claims (15)

In an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, the light energy at the ultraviolet rays, 2J / cm ² or more 7J / cm ² or less, the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is less than 90 ° C. 70 ° C. or higher An electrophotographic photosensitive member. ^2. The electrophotographic photosensitive member according to claim 1, wherein the ultraviolet irradiation intensity is 500 mW / cm ² or more and 1000 mW / cm ² or less.   The electrophotographic photosensitive member according to claim 1 or 2, wherein the maximum temperature reached on the surface of the photosensitive member is reached by radiant heat of ultraviolet irradiation energy, and the temperature is controlled by flowing air through the support. body.   The electrophotographic photosensitive member according to claim 1, wherein an initial temperature of the surface of the photosensitive member before ultraviolet irradiation is 30 ° C. or less.   5. The electrophotographic photosensitive member according to claim 1, wherein the rate of decrease in positive charging potential of the photoconductor is 50% or less, and the elastic power of the surface layer is 52% or more. body.   6. The (b) charge transporting structure is selected from the group consisting of a triarylamine structure, a hydrazone structure, a pyrazoline structure, and a carbazole structure. Electrophotographic photoreceptor   7. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting structure (b) is a triarylamine structure.   The electrophotographic image according to any one of claims 1 to 7, wherein the radically polymerizable compound (b) has a functional group selected from the group consisting of an acryloyloxy group and a methacryloyloxy group. Photoconductor.   9. The electrophotographic photosensitive member according to claim 1, wherein the radically polymerizable compound (b) has one functional group.   The trifunctional or more radically polymerizable monomer of (i) has three or more functional groups selected from the group consisting of an acryloyloxy group and a methacryloyloxy group. The electrophotographic photosensitive member according to any one of the above.   The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer, a charge transport layer, and a crosslinked surface layer from the support side. In the method for producing an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support, the surface layer comprises:
Crosslinking cured by irradiating ultraviolet rays onto a monomer mixture containing (b) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) a radical polymerizable compound having a charge transport structure is formed of a resin film, the light energy at the ultraviolet rays, 2J / cm ² or more 7J / cm ² or less, the maximum temperature of the photosensitive member surface at the time of irradiation of ultraviolet rays is less than 90 ° C. 70 ° C. or higher A method for producing an electrophotographic photosensitive member.   An image forming method comprising: repeatedly performing at least charging, image exposure, development, and transfer using the electrophotographic photosensitive member according to claim 1.   An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.   An image forming apparatus comprising at least one means selected from the group consisting of an electrophotographic photosensitive member according to claim 1 and a charging means, a developing means, a transfer means, a cleaning means, and a charge eliminating means. A process cartridge for an image forming apparatus, wherein the process cartridge is removable from the apparatus main body.

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