JP2008233118A - Electrophotographic photoreceptor, method for manufacturing same, image forming method using same, image forming apparatus, and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor and a method for manufacturing the photoreceptor having stable electric characteristics and achieving excellent durability for a long period of time by forming a crosslinked surface layer having high wear resistance and favorable electric characteristics, and to provide an image forming method, an image forming apparatus and a process cartridge for an image forming apparatus using the above long-life high-performance photoreceptor. <P>SOLUTION: The method for manufacturing an electrophotographic photoreceptor having at least a photosensitive layer on a conductive support is characterized in that: the surface layer of the photosensitive layer is a crosslinked surface layer cured by irradiation with luminous energy; and the breadth of temperature increase on the photoreceptor surface during irradiation with luminous energy is within 15°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member that has high wear resistance, excellent durability, and good electrical characteristics, and has realized high-quality image formation over a long period of time, and a method for manufacturing the same. 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. This is because, 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 rubber hardness of the cleaning blade and the contact pressure must be increased 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 (see Patent Document 1), and (2) using a polymer type charge transport material (Patent Document 2). And (3) those obtained by dispersing an inorganic filler in the surface layer (see Patent Document 3). Among these techniques, those using the curable binder (1) have a poor residual potential due to poor compatibility with the charge transport material, and impurities such as polymerization initiators and unreacted residues. There is a tendency that a decrease in 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 (see 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. The binder resin has a carbon-carbon double bond and is reactive with the charge transport material, and the binder resin has a double bond. And non-reactive ones 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 (see 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, there is also known a cross-linked 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 (Patent Document 7). , Patent Document 8, Patent Document 9, etc.), by using a monofunctional radically polymerizable compound having a charge transporting structure and curing the surface layer, the photosensitive layer cracks simultaneously with mechanical and electrical durability. Is suppressed. Further, these photoconductors form a crosslinked surface layer by light energy, thereby realizing a more durable surface layer. It is known that the cross-linked surface layer using such light energy changes its curability depending on the curing conditions and greatly affects the characteristics of the photoreceptor (see Patent Documents 10 and 11, etc.). These photoconductors show that the film quality of the crosslinked surface layer changes depending on the surface temperature of the photoconductor when irradiated with light energy, and a highly smooth film is realized. However, as a result of investigations by the present inventors, these photoreceptors have an exposure portion potential that increases depending on the curing conditions, which may cause a decrease in image density, and have electrical stability due to long-term use. That wasn't true. From the above, it cannot be said that the current method for producing a photoreceptor having a crosslinked surface layer cured by light energy sufficiently satisfies electrical characteristics and durability.

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 2006-38978 A JP 2006-145880 A

  An object of the present invention is to provide an electrophotographic photosensitive member that has a stable electrical property by forming a cross-linked surface layer having high wear resistance and good electrical property, and at the same time, realizes excellent durability 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.

  As a result of intensive studies, the inventors of the present invention have produced a method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support by curing the surface layer of the photosensitive layer by irradiating light energy, The inventors have found that the above-mentioned problems can be solved by producing an electrophotographic photosensitive member with a temperature rise range of the photosensitive member surface temperature within 15 ° C. during the irradiation of light energy, and have reached the present invention.

That is, the electrophotographic photosensitive member, the manufacturing method thereof, the image forming method using the same, the image forming apparatus, and the process cartridge for the image forming apparatus according to the present invention are as follows.
(1) In the method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer is a crosslinked surface layer cured by irradiating light energy, and the light energy The method for producing an electrophotographic photosensitive member, wherein the temperature rise of the photosensitive member surface temperature during irradiation is within 15 ° C. ”,
(2) "The method for producing an electrophotographic photosensitive member according to (1) above, wherein a maximum temperature reached on the surface of the photosensitive member when the crosslinked surface layer is formed is 40 ° C or higher",
(3) The method for producing an electrophotographic photosensitive member according to (1) or (2) above, wherein the initial temperature of the surface of the photosensitive member at the time of forming the crosslinked surface layer is 40 ° C. or lower. "
(4) "Electrophotographic photosensitive member produced by the method for producing an electrophotographic photosensitive member according to any one of (1) to (3)",
(5) "The crosslinked surface layer is
(A) a tri- or more functional radical polymerizable monomer having no charge transporting structure;
(B) a radically polymerizable compound having a charge transporting structure;
The electrophotographic photosensitive member according to item (4) above, comprising:
(6) In the item (5), wherein 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 photosensitive member described,
(7) "The electrophotographic photosensitive member according to (5) or (6) above, wherein the charge transporting structure of (b) is a triarylamine structure",
(8) The items (5) to ((2) above, wherein the radically polymerizable compound (b) has a functional group selected from the group consisting of an acryloyloxy group and a methacryloyloxy group. 7) the electrophotographic photosensitive member according to any one of items
(9) The electrophotographic photosensitive member according to any one of (5) to (8) above, wherein the number of functional groups of the radically polymerizable compound (b) is one. "
(10) The above-mentioned (a) wherein the trifunctional or higher functional radically polymerizable monomer of (a) 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 (5) to (9),
(11) "The electrophotographic photosensitive member according to any one of (4) to (10), wherein the crosslinkable surface layer includes a photopolymerization initiator",
(12) In any one of (4) to (11) above, the photosensitive layer has a stacked structure of a charge generation layer and a charge transport layer from the conductive support side. Electrophotographic photoreceptor ",
(13) “Electrophotographic photosensitive member, electrostatic latent image forming means for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image with toner to form a visible image. An image forming apparatus comprising: a developing unit that transfers the visible image onto a recording medium; and a fixing unit that fixes the transferred image transferred onto the recording medium. An image forming apparatus comprising the electrophotographic photosensitive member according to any one of (4) to (12),
(14) "An electrostatic latent image forming step of forming an electrostatic latent image on an electrophotographic photosensitive member, a developing step of developing the electrostatic latent image with toner to form a visible image, and An image forming method comprising a transfer step of transferring a visible image to a recording medium and a fixing step of fixing the transferred image transferred to the recording medium, wherein the electrophotographic photoreceptor is the item (4). Thru | or the image forming method characterized by being an electrophotographic photosensitive member in any one of (12).
(15) "The electrophotographic photosensitive member according to any one of (4) to (12)," at least one of an electrostatic latent image forming unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit. And a process cartridge characterized by comprising:

  In the method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support according to the present invention, the surface layer of the photosensitive layer is formed by being cured by irradiating with light energy. By producing an electrophotographic photosensitive member with a temperature rise range of the photoreceptor surface temperature within 15 ° C., an electrophotographic photosensitive member having excellent durability, stable electrical characteristics, and capable of maintaining a high-quality image is realized. The 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 is based on the following basic idea.
The method for producing an electrophotographic photosensitive member of the present invention relates to a method for producing a photosensitive layer or a surface layer formed by light energy irradiation. The surface layer formed by light energy irradiation can form a three-dimensional crosslinked surface layer, and can dramatically improve the wear resistance of the electrophotographic photosensitive member. However, in such a crosslinked surface layer, unreacted groups inside the layer remain and become charge traps, which may lead to deterioration of electrical characteristics. The object of the present invention is to reduce unreacted residues in the crosslinked surface layer by such light energy irradiation. According to the present invention, it has been found that the surface temperature of the photoconductor upon irradiation with light energy affects the curing reaction, and in particular, the temperature range at the beginning and at the end of light energy irradiation affects the electrical characteristics of the photoconductor. . About this reason, the characteristics differ between the part that reacted at low temperature and the part that reacted at high temperature in the early stage of light irradiation, the interface between them becomes a charge trap, and there are many unreacted residues in the low temperature reaction part, It is presumed that they become charge traps and have an adverse effect on charge transport properties.

  Based on these findings, the present inventors have conducted an arbitrary study, and as a result, found that better electrical characteristics can be obtained by setting the temperature rise width of the surface of the photoreceptor by irradiation with light energy to 15 ° C. or less. When the temperature rise is larger than 15 ° C., the electrical characteristics are lowered, and when the photosensitive member is fatigued, the exposed portion potential is increased, and an abnormal image such as a decrease in image density is caused. The temperature increase width should be small and more preferably within 12 ° C. In addition, the higher the maximum temperature reached on the surface of the photoconductor when irradiated with light energy, the higher the curability. In order to improve the wear resistance of the photoconductor, the maximum temperature is preferably 40 ° C. or higher. Further, the initial temperature of the surface of the photoreceptor before irradiation with light energy is preferably 40 ° C. or less. When the temperature rise width on the surface of the photoreceptor is within 15 ° C., the volume shrinkage of the film is small and wrinkles are not easily generated on the film. However, when the initial temperature is higher than 40 ° C., a part of the monomer is melted. The surface properties of the film may deteriorate.

  The photoreceptor of the present invention is a photoreceptor having a surface layer cross-linked by light energy irradiation, and in particular, a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a charge transport structure. By using a surface layer obtained by curing the mixture, an electrophotographic photosensitive member having higher wear resistance and stable electric characteristics is achieved. By using a tri- or higher functional radical polymerizable monomer that does not have a charge transporting structure, a three-dimensional network structure is developed, and a high hardness cross-linked surface layer with a very high cross-linking density is obtained, achieving high wear resistance. Is done. Moreover, in addition to the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure, it contains a radical polymerizable compound having a charge transporting structure, so that these are simultaneously polymerized and cured in a short time, and have high hardness. A cross-linking bond is formed, and an improvement in durability is achieved. Furthermore, by curing a radically polymerizable monomer having a large number of reactive functional groups and a fast curing speed and having no charge transporting structure and having a trifunctional or higher functionality and a radically polymerizable compound having a charge transporting structure, It is possible to form a uniform crosslinked film with little distortion, 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 is possible to achieve both an improvement in wear resistance and a stable electrostatic property and an electrophotographic photoreceptor free from cracks.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following examples.
The present invention relates to a method for producing a photoreceptor having a surface layer crosslinked by light energy. The light energy irradiation method of the present invention will be described below. In the present invention, ultraviolet light is used as light energy. Examples of the ultraviolet irradiation lamp include a high-pressure mercury lamp and a metal halide lamp. When light energy is irradiated onto the surface of the photoconductor, the surface temperature of the photoconductor rapidly increases due to the radiant heat. The surface temperature of the photosensitive member at that time has a temperature profile as shown in FIG. The difference between the maximum temperature reached and the initial temperature in FIG. 1 is the temperature rise range of the present invention, which is characterized by being within 15 ° C. By setting the temperature within 15 ° C., it is possible to realize a photoreceptor having good electrical characteristics even during fatigue due to long-term use. In addition, the higher the maximum temperature reached on the surface of the photoreceptor when irradiated with light energy in FIG. 1, the higher the film curability and the higher the wear resistance of the photoreceptor, so that the maximum temperature is preferably 40 ° C. or higher. . Further, the initial temperature of the surface of the photoreceptor before irradiation with light energy is preferably 40 ° C. or less. When the temperature rise width on the surface of the photoreceptor is within 15 ° C., the volume shrinkage of the film is small and wrinkles are not easily generated on the film. However, when the initial temperature is higher than 40 ° C., a part of the monomer is melted. The surface properties of the film may deteriorate.

  Any method may be used as a method for controlling the temperature increase width at the time of light energy irradiation. In the present invention, since the support is on the drum, the temperature increase width due to radiant heat is caused by flowing cooling water inside the drum. , A method of controlling the temperature rise of the surface of the photoconductor by applying cold air from the outside of the photoconductor, a method of reducing the temperature rise range by lowering the irradiation output of ultraviolet rays, applying heat from the outside by an infrared heater, etc. There is a method of decreasing the output of the infrared heater and controlling the temperature increase width as the temperature rises due to ultraviolet irradiation, and these methods can be combined.

  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, a drum-shaped support is used and measurement is performed by bringing a contact-type thermocouple into contact with the surface of the photoreceptor from the non-irradiated side of the photoreceptor irradiated with ultraviolet rays. A digital multimeter PC520M and a K-type thermocouple are used.

Next, the surface layer coating method of the present invention will be described. Examples of the method for coating the surface layer of the photoreceptor generally include a spray coating method, a ring coating method, and a dip coating method.
When the crosslinked surface layer is a surface portion of a photosensitive layer having a multilayer structure or a single layer structure, the thickness of the crosslinked surface layer is preferably 1 to 20 μm, and more 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. When the crosslinked surface layer is a charge transport layer of the photoreceptor, the thickness of the crosslinked surface layer is preferably 10 to 30 μm, and more preferably 10 to 25 μm. If the thickness is less than 10 μm, a sufficient charging potential cannot be maintained. If the thickness is more than 30 μm, peeling from the conductive substrate or the undercoat layer tends to occur due to volume shrinkage during curing.

  Next, the constituent material of the surface layer coating solution of the present invention will be described. In the present invention, a polymerizable compound that crosslinks by light energy is used as the surface layer coating liquid. In particular, (a) a tri- or higher functional radical polymerizable monomer having no charge transport structure and (b) charge transport. It is preferable to use a mixture in which a radically polymerizable compound having a crystalline structure is mixed. Examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure (a) include hole transporting structures such as triarylamine, hydrazone, pyrazoline, and carbazole, such as condensed polycyclic quinone, diphenoquinone, and cyano. A monomer having no electron transport structure such as an electron-withdrawing aromatic ring having a group or a nitro group and having three or more radically polymerizable functional groups. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization.

Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) As the 1-substituted ethylene functional group, for example, a functional group represented by the following general formula (1) is preferably exemplified.
_{CH 2 = CH-X 1 -} ···· general formula (1)
[In the general formula (1), X ₁ represents an arylene group such as a phenylene group or a naphthylene group which may have a substituent, an alkenylene group which may have a substituent, or a —CO— group. , —COO— group, —CON (R ₃₀ ) — group (where R ₃₀ is a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, an aralkyl group such as a benzyl group, a naphthylmethyl group or a phenethyl group, or a phenyl group) Represents an aryl group such as a naphthyl group), or a —S— group. ]
Specific examples of these substituents include vinyl, styryl, 2-methyl-1,3-butadienyl, vinylcarbonyl, acryloyloxy, acryloylamide, and vinylthioether groups.

(2) As the 1,1-substituted ethylene functional group, for example, a functional group represented by the following general formula (2) is preferably exemplified.
_{CH 2 = C (Y) -X} 2 - ···· general formula (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, An aryl group such as a naphthyl group, a halogen atom, a cyano group, a nitro group, an alkoxy group such as a methoxy group or an ethoxy group, and —COOR ₃₁ group (where R ₃₁ is a hydrogen atom or a methyl group optionally having a substituent) 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 (wherein R ₃₂ and R ₃₃ are a hydrogen atom, an optionally substituted methyl group, an alkyl group such as an ethyl group, an optionally substituted benzyl group, a naphthylmethyl group) , Rui aralkyl groups such as phenethyl group, or a substituent a phenyl group which may have a represents an aryl group such as a naphthyl group, may be the same or different from each other.) Further, X ₂ is the formula The same substituent as X _{1 in} (1), a single bond, and an alkylene group are represented. However, Y, at least one oxycarbonyl group in X _2, a cyano group, an alkenylene group, and an aromatic ring. ]
Examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.
In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ , and Y include, for example, a halogen atom, a nitro group, a cyano group, a methyl group, an alkyl group such as an ethyl group, a methoxy group, an ethoxy group, and the like And 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 exceeds 80% by weight, the content of the charge transporting compound is lowered, and the electrical characteristics are deteriorated. Since the required wear resistance and electrical characteristics differ depending on the process used, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 30 to 70% by weight is most preferable.

  The 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.

  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.

〔式中、Ｒ_１は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基、置換基を有してもよいアリール基、シアノ基、ニトロ基、アルコキシ基、−ＣＯＯＲ_２（Ｒ_２は水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基）、ハロゲン化カルボニル基若しくはＣＯＮＲ_３Ｒ_４（Ｒ_３及びＲ_４は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアラルキル基又は置換基を有してもよいアリール基を示し、互いに同一であっても異なっていてもよい）を表わし、Ａｒ_１、Ａｒ_２は置換もしくは未置換のアリーレン基を表わし、同一であっても異なってもよい。Ａｒ_３、Ａｒ_４は置換もしくは未置換のアリール基を表わし、同一であっても異なってもよい。Ｘは単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わし、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。〕

[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 from each other, and Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, which may be the same or different. Ar ₃ 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 represent a substituted or unsubstituted aryl group. In the present invention, the aryl group includes a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group, and includes the following groups.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an As-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , 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.

Further, 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, further including 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 (—ORa), and Ra 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.
(6) The substituent represented by the following formula | equation is mentioned.

（式中、Ｒ_１０及びＲ_１１は各々独立に水素原子、前記（２）で定義したアルキル基、またはアリール基を表わす。アリール基としては、例えばフェニル基、ビフェニル基又はナフチル基が挙げられ、これらはＣ_１〜Ｃ_４のアルコキシ基、Ｃ_１〜Ｃ_４のアルキル基またはハロゲン原子を置換基として含有してもよい。Ｒ_１０及びＲ_１１は共同で環を形成してもよい。）
具体的には、アミノ基、ジエチルアミノ基、Ｎ−メチル−Ｎ−フェニルアミノ基、Ｎ，Ｎ−ジフェニルアミノ基、Ｎ，Ｎ−ジ（トリール）アミノ基、ジベンジルアミノ基、ピペリジノ基、モルホリノ基、ピロリジノ基等が挙げられる。
（７）メチレンジオキシ基、又はメチレンジチオ基等のアルキレンジオキシ基又はアルキレンジチオ基等が挙げられる。
（８）置換又は無置換のスチリル基、置換又は無置換のβ−フェニルスチリル基、ジフェニルアミノフェニル基、ジトリルアミノフェニル基等。

(Wherein R ₁₀ and R ₁₁ each independently represent a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, 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 and Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ and Ar ₄ .

  X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.

The alkylene group in X is a C _{1 to} C ₁₂ , preferably C _{1 to} C ₈ , more preferably C _{1 to} C ₄ linear or branched alkylene group, and these alkylene groups further include fluorine. atom, a hydroxyl group, a cyano _group, optionally having a C 1 -C ₄ alkoxy group, a phenyl group or a halogen _atom, C 1 -C phenyl group substituted by ₄ alkyl or alkoxy group of _C 1 -C ₄ Also good. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene. Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

The cycloalkylene group in X 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.

  The vinylene group in X is

で表わされ、Ｒ_１２は水素、アルキル基〔前記（２）で定義されるアルキル基と同じ〕、アリール基（前記Ａｒ_３、Ａｒ_４で表わされるアリール基と同じ）、ａは１または２、ｂは１〜３を表わす。

R ₁₂ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2 , B represents 1-3.

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

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

（式中、ｐ、ｑ、ｏはそれぞれ０又は１の整数、Ｒ_５は水素原子、メチル基を表わし、Ｒ_６、Ｒ_７は水素原子以外の置換基で炭素数１〜６のアルキル基を表わし、複数の場合は異なっても良い。ｓ、ｔは０〜３の整数を表わす。Ｚ_２は単結合、メチレン基、エチレン基、

(In the formula, p, q and o are each an integer of 0 or 1, R ₅ represents a hydrogen atom or a methyl group, and R ₆ and R ₇ represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. 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,

を表わす。）
上記一般式で表わされる化合物としては、Ｒ_６、Ｒ_７の置換基として、特にメチル基、エチル基である化合物が好ましい。

Represents. )
As the compound represented by the above general formula, a compound having a methyl group or an ethyl group is particularly preferable as a substituent for R ₆ and R ₇ .

  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.
B ₁ —Ar ₅ —CH═CH—Ar ₆ —B ₂ ... General formula (6)
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.
Ar ₆ is a monovalent group or divalent group composed of an aromatic hydrocarbon skeleton having at least one tertiary amino group, or a monovalent group composed of a heterocyclic compound skeleton having at least one tertiary amino group. Alternatively, it represents a divalent group. Here, the aromatic hydrocarbon skeleton having a tertiary amino group is represented by the following general formula (7).

（式中、Ｒ_１３、Ｒ_１４はアシル基、置換もしくは無置換のアルキル基、置換もしくは無置換のアリール基を表わす。Ａｒ_７はアリール基を表わす。ｗは１〜３の整数を表わす。）

(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 of R ₁₃ and R ₁₄ is a phenyl group, a naphthyl group, a biphenylyl group, a terphenylyl group, a pyrenyl group, a fluorenyl group, a 9,9-dimethyl-2-fluorenyl group, an azulenyl group, an anthryl group, In addition to the triphenylenyl group and the chrysenyl group, a group represented by the following general formula (8) can be exemplified.

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

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

（ここで、Ｒ_２１は、水素原子、Ａｒ_５で定義された置換もしくは無置換のアルキル基、アルコキシ基、ハロゲン原子、Ｒ_１３で定義された置換もしくは無置換のアリール基、アミノ基、ニトロ基、シアノ基を表わし、Ｒ_２２は、水素原子、Ａｒ_５定義された置換もしくは無置換のアルキル基、Ｒ_１３で定義された置換もしくは無置換のアリール基を表わし、ｉは１〜１２の整数、ｊは１〜３の整数を表わす。）］

(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 is present, and the presence of both is excluded.

  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.

式中、Ｒ_８、Ｒ_９は、置換もしくは無置換のアルキル基、置換もしくは無置換のアルコキシ基、ハロゲン原子を表わし、Ａｒ_７、Ａｒ_８は、置換もしくは無置換のアリール基またはアリレン基、置換又は無置換のベンジル基を表わす。アルキル基、アルコキシ基、ハロゲン原子は前記Ａｒ_５で述べたものが同様に適用される。
アリール基は、Ｒ_１３、Ｒ_１４で定義されたアリール基と同様である。アリレン基は、そのアリール基から誘導される二価基である。
Ｂ_１〜Ｂ_４は、一般式（６）におけるＢ_１、Ｂ_２と同様である。ｕは０〜５の整数、ｖは０〜４の整数を表わす。

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 Alternatively, it represents an unsubstituted benzyl group. As the alkyl group, alkoxy group, and halogen atom, those described in the above 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 radical polymerizable compound having a charge transporting structure used in the present invention, NO. 1-NO. However, the present invention is 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. The required electrical characteristics and wear resistance differ depending on the process to be used, so 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 the monomer and (b) a radically polymerizable compound having a charge transporting structure. In addition to this, viscosity adjustment during coating, stress relaxation of the crosslinked surface layer, lower surface energy and friction Monofunctional and bifunctional radically polymerizable monomers, functional monomers and radically polymerizable oligomers can be used in combination for the purpose of imparting a function such as a reduction in coefficient. 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 the 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 solvent solution composition (coating solution) of a monomer mixture containing a monofunctional radically polymerizable compound having a transporting structure, drying, polymerizing and curing the composition. If necessary, a photopolymerization initiator may be used in the solvent solution composition in order to allow the crosslinking reaction to proceed efficiently.

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 applies 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 to give light energy. Cured and formed. In some cases, the coating solution is applied after dilution. Examples of the solvent used include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ethyl acetate and acetic acid. Esters such as butyl, ethers such as tetrahydrofuran, dioxane, propyl ether, halogens such as dichloromethane, dichloroethane, trichloroethane, chlorobenzene, aromatics such as benzene, toluene, xylene, methyl cellosolve, ethyl cellosolve, cellosolve acetate, etc. Examples include cellosolve. 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 and the target film thickness, and is arbitrary, but the dilution ratio is preferably 5% to 40% from the viewpoint of film thickness controllability and surface leveling.

The cross-linked surface layer in the present invention is cured by light energy irradiation after applying the coating liquid. As light energy, UV irradiation light sources such as high-pressure mercury lamps and metal halide lamps, which mainly emit light in the ultraviolet light, can be used, but a visible light source can also be selected according to the absorption wavelength of radical polymerizable substances and photopolymerization initiators. It is. Irradiation light amount is 50 mW / cm ² or more is preferable, 500~1000mW / cm ² is more preferable. When irradiation light with an illuminance higher than 1000 mW / cm ² is used, the progress rate of the polymerization reaction increases, and a strong cross-linked film can be formed. May cause decline.

  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. 2 is a cross-sectional view showing the electrophotographic photosensitive member of the present invention, in which a single layer structure in which a photosensitive layer (33) having both a charge generating function and a charge transporting function is provided on a conductive support (31). This is a photoreceptor. FIG. 2-A shows the case where the crosslinked surface layer is the entire photosensitive layer, and FIG. 2-B shows the case where the crosslinked surface layer is the surface portion of the photosensitive layer.
FIG. 3 shows a photoreceptor having a laminated structure in which a charge generation layer (35) having a charge generation function and a charge transport layer (37) having a charge transport function are laminated on a conductive support (31). . FIG. 3-A shows the case where the cross-linked surface layer is the entire charge transport layer, and FIG. 3-B shows the case where the cross-linked surface layer is the surface portion of the charge transport layer.

<About conductive support>
As the conductive support (31), a material having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, a metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium is deposited or sputtered to form film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. After conversion, a tube that has been subjected to surface treatment such as cutting, superfinishing, or polishing can be used. In addition, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as the conductive support (31).

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

<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 (35) 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 carbazole skeleton, azo pigments having triphenylamine skeleton, azo pigments having diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, 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 (35) is 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. No. 1, JP-A 09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 09-227669. JP 09-235367 A, JP 09-241369 A Charge transporting polymer materials described in JP 09-268226 A, JP 09-272735 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Can be mentioned.
Specific examples of the latter include polysilylene polymers described in, for example, JP-A 63-285552, JP-A 05-19497, JP-A 05-70595, JP-A 10-73944, and the like. Illustrated.

The charge generation layer (35) may contain a low molecular charge transport material.
Low molecular charge transport materials that can be used in combination with the charge generation layer (35) include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.

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

Methods for forming the charge generation layer (35) include a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.
In addition, in order to provide a charge generation layer by the casting method described later, if necessary, the inorganic or organic charge generation material together with a binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. Can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. . Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The 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 (37) is a layer having a charge transport function, and the crosslinked surface layer having a charge transport structure of the present invention is useful as a charge transport layer. When the cross-linked surface layer is the entire charge transport layer (37), the radical polymerizable composition (charge transport structure of the present invention is formed on the charge generation layer (35) as described in the above cross-linked surface layer preparation method. A coating liquid containing a radically polymerizable monomer and a charge transporting compound having a radically polymerizable functional group, which are not included, is applied and cured by light energy to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If it is thinner than 10 μm, a sufficient charging potential cannot be maintained, and if it is thicker than 30 μm, peeling from the lower layer tends to occur due to volume shrinkage during curing.
When the cross-linked surface layer is formed on the surface portion of the charge transport layer (37) and the charge transport layer (37) has a laminated structure, the lower layer portion of the charge transport layer has a charge transport material having a charge transport function and a binder. The resin is dissolved or dispersed in a suitable solvent, and this is formed on the charge generation layer (35) by coating and drying, and a coating solution containing the radical polymerizable composition of the present invention is coated thereon. And cured by light energy.
As the charge transport material, the electron transport material, hole transport material and polymer charge transport material described in the charge generation layer (35) can be used. As described above, the use of the polymer charge transport material can reduce the solubility of the lower layer at the time of coating the surface layer, and is particularly useful.

Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin. However, when a polymer charge transport material is used, it can be used alone or in combination with a binder resin.

  As the solvent used for coating the lower layer portion of the charge transport layer, the same solvent as that for the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. The lower layer portion of the charge transport layer can be formed by a coating method similar to that for the charge generation layer (35).

If necessary, a plasticizer and a leveling agent can be added.
As a plasticizer that can be used in combination with the lower layer portion of 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 100 parts by weight of the binder resin. On the other hand, about 0 to 30 parts by weight is appropriate.
As a leveling agent that can be used in combination with the lower layer portion of the charge transport layer, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used. About 0 to 1 part by weight is appropriate for 100 parts by weight of the binder resin.
The thickness of the lower layer portion of the charge transport layer is appropriately about 5 to 40 μm, preferably about 10 to 30 μm.

  When the cross-linked surface layer is the surface portion of the charge transport layer (37), the radical polymerizable composition of the present invention is contained on the lower layer portion of the charge transport layer as described in the method for preparing a cross-linked surface layer. After coating the coating liquid, it is cured by light energy to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. If the thickness is less than 1 μm, the durability varies due to uneven film thickness. If the thickness is more than 20 μm, the entire thickness of the charge transport layer is increased, and the reproducibility of the image is reduced due to the diffusion of charges.

<Single photosensitive layer>
The photosensitive layer having a single layer structure is a layer having a charge generation function and a charge transport function at the same time, and the cross-linked surface layer having the charge transport structure of the present invention has a single layer structure by containing a charge generation material having a charge generation function. It is useful as a photosensitive layer. As described in the method for forming the charge generation layer, the charge generation material is dispersed together with the coating solution containing the radical polymerizable composition, applied onto the charge generation layer (35), and then cured by light energy. And a crosslinked surface layer is formed. In addition, you may add the liquid in which the charge generation material was previously disperse | distributed with the solvent to this coating solution for bridge | crosslinking surface layers. At this time, the film thickness of the crosslinked surface layer is 10 to 30 μm, preferably 10 to 25 μm. If the thickness is less than 10 μm, a sufficient charging potential cannot be maintained. If the thickness is more than 30 μm, peeling from the conductive substrate or the undercoat layer tends to occur due to volume shrinkage during curing.

  Further, when the crosslinked surface layer is a surface portion of a photosensitive layer having a single layer structure, the lower layer portion of the photosensitive layer is composed of a charge generating material having a charge generating function, a charge transporting material having a charge transport function, and a binder resin in an appropriate solvent. It can be formed by dissolving or dispersing in, coating and drying. Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the 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 (35) and the charge transport layer (37). As the binder resin, in addition to the binder resin previously mentioned in the section of the charge transport layer (37), the binder resin mentioned in the charge generation layer (35) may be mixed and used. In addition, the above-described polymer charge transport materials can also be used, which is useful in that contamination of the lower photosensitive layer composition into the crosslinked surface layer can be reduced. The thickness of the lower layer portion of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.

When the crosslinked surface layer is a surface portion of a photosensitive layer having a single layer structure, the coating solution containing the radically polymerizable composition of the present invention and the charge generating material is applied onto the lower layer portion of the photosensitive layer as described above. Cured with light energy to form a crosslinked surface layer. At this time, the film thickness of the crosslinked surface layer is 1 to 20 μm, preferably 2 to 10 μm. When the thickness is less than 1 μm, the durability varies due to the film thickness unevenness.
The charge generating material contained in the photosensitive layer having a single layer structure is preferably 1 to 30% by weight based on the total amount of the photosensitive layer, and the binder resin contained in the lower layer portion of the photosensitive layer is 20 to 80% by weight of the total amount. 10 to 70 parts by weight of the transport material is preferably used.

<About the intermediate layer>
In the photoreceptor of the present invention, when the crosslinked surface layer is the surface portion of the photosensitive layer, it is possible to provide an intermediate layer for the purpose of suppressing mixing of lower layer components into the crosslinked surface layer or improving adhesion with the lower layer. is there. This intermediate layer prevents inhibition of the curing reaction and unevenness of the crosslinked surface layer caused by mixing of the lower photosensitive layer composition in the outermost surface layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the lower photosensitive layer and the surface cross-linked layer.
In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method is employed as described above. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.

<About the undercoat layer>
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support (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 matter 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 and fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant in the present invention is 0.01 to 10% by weight based on the total weight of the layer to be added.

<Image Forming Method and Apparatus>
Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
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, the image is held. An image forming method and an image forming apparatus including a process of transferring a toner image onto a body (transfer paper), fixing, and cleaning of 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 the photosensitive member.

  FIG. 4 is a schematic diagram illustrating an example of an image forming apparatus. A charging charger (3) is used as a means for charging the photoconductor on average. As the charging means, a corotron device, a scorotron device, a solid discharge element, a needle electrode device, a roller charging device, a conductive brush device, or the like is used, and a known system can be used.

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

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

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

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

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

  Next, a fur brush (14) and a cleaning blade (15) are used to clean the toner remaining on the photoreceptor after transfer. Further, a pre-cleaning charger (13) may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.

Next, a neutralizing unit is used for the purpose of removing the latent image on the photoconductor as necessary. 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.
This 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. 5, the surface of the photoreceptor (101) is exposed by charging by the charging means (102) and exposure by the exposure means (103) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed, and the electrostatic latent image is developed with toner by the developing means (104). The toner development is transferred to the transfer body (105) by the transfer means (106), and printed. Be out. Next, the surface of the photoconductor after the image transfer is cleaned by a cleaning unit (107), and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

The present invention provides a process cartridge for an image forming apparatus in which a 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 photosensitive member of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

<Synthesis Example of 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 (1) Synthesis of Hydroxy Group-Substituted Triarylamine Compound (Structural Formula B below) Methoxy group-substituted triarylamine compound (Structural Formula A below) 113.85 g (0 0.3 mol) and 138 g (0.92 mol) of sodium iodide were added with 240 ml of sulfolane and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%, melting point: 64.0-66.0 ° C.) of the white crystal of the following structural formula B was obtained. The elemental analysis results are shown below.

(2) Synthesis of Triarylamino Group-Substituted Acrylate Compound (Exemplary Compound No. 54 in Table 1-3) Hydroxy Group-Substituted Triarylamine Compound (Structural Formula B) Obtained in (1) above 82.9 g (0 .227 mol) 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 (1) Preparation of diethyl 2-hydroxybenzylphosphonate 38.4 g of 2-hydroxybenzyl alcohol (manufactured by Tokyo Chemical Co., Ltd.) was added to a reaction vessel equipped with a stirrer, thermometer and dropping funnel. 80 ml of o-xylene was added, 62.8 g of triethyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) was slowly added dropwise at 80 ° C. under a nitrogen stream, and the reaction was further carried out 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%)

(2) 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 subjected to column purification with silica gel, followed by crystallization in hexane, and 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.)

(3) Preparation of 4 ′-(N, N-bis (4-methylphenyl) amino) stilben-2-yl acrylate In a reaction vessel equipped with a stirrer, thermometer and 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こと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, and acrylation or methacrylation is carried out to produce various acrylic acids. 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 an undercoating layer coating solution, a charge generation layer coating solution, and a charge transporting layer coating solution in the following composition on a φ100 mm aluminum cylinder sequentially by a dip coating method and drying, A 3.0 μm undercoat layer, 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 and Chemicals)
・ 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-Tetrahydrofuran solution of 1% silicone oil: 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 applied on the charge transport layer by spraying, cured by ultraviolet irradiation, and dried to obtain an electrophotographic photoreceptor. The composition of the crosslinked surface layer coating solution is shown below.

[Coating liquid for cross-linked surface layer]
-Radical polymerizable compound having a charge transporting structure: 10 parts [Exemplary Compound NO. 54 (Molecular weight: 419, number of functional groups: 1)]
・ Trifunctional or higher radical polymerizable monomer having no charge transport 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.)

After spray coating, UV irradiation was performed while rotating the support at 30 rpm with a UV lamp system manufactured by Fusion, a UV irradiation device. For the ultraviolet irradiation, a metal halide lamp was used, the distance between the ultraviolet lamp and the surface of the photoconductor was 50 mm, the irradiation intensity was 800 mW / cm ^2, and ultraviolet irradiation was performed for 120 seconds to cure the coating film. At the time of ultraviolet irradiation, water at 37 ° C. is circulated inside the support, and ultraviolet light is irradiated while applying cold air of 20 ° C. to the surface of the photoconductor, so that the initial temperature of the photoconductor surface is 37 ° C. and the maximum temperature reached 52 ° C. The temperature increase width was controlled at 15 ° C. After the ultraviolet irradiation, drying at 100 ° C. for 10 minutes was added to provide a crosslinked surface layer having a film thickness of 8 μm to obtain the electrophotographic photosensitive member of the present invention.

(Example 2)
At the time of ultraviolet irradiation in Example 1, the temperature of water circulated inside the support was 37 ° C., and further, ultraviolet rays were irradiated while applying 15 ° C. cold air to the photoreceptor, and the initial temperature of the photoreceptor surface was 37 ° C., the highest. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the ultimate temperature was 48 ° C. and the temperature increase range was 11 ° C.

(Example 3)
At the time of ultraviolet irradiation in Example 1, the temperature of the water circulated inside the support was 37 ° C., and further, ultraviolet rays were irradiated while applying 10 ° C. cold air to the photosensitive member, and the initial temperature of the photosensitive member surface was 37 ° C., the highest. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the ultimate temperature was 45 ° C. and the temperature increase was 8 ° C.

Example 4
At the time of ultraviolet irradiation of Example 1, the ultraviolet irradiation intensity was changed to 600 mW / cm ² , except that the initial temperature of the photoreceptor surface was 37 ° C., the maximum temperature reached was 47 ° C., and the temperature increase range was 10 ° C. An electrophotographic photoreceptor was produced in the same manner as in Example 1.

(Example 5)
At the time of ultraviolet irradiation of Example 1, the ultraviolet irradiation intensity was changed to 500 mW / cm ² , except that the initial temperature of the photoreceptor surface was 37 ° C., the maximum temperature reached was 43 ° C., and the temperature increase range was 6 ° C. An electrophotographic photoreceptor was produced in the same manner as in Example 1.

(Example 6)
In the ultraviolet irradiation of Example 1, the ultraviolet irradiation intensity was changed to 650 mW / cm ² , the temperature of the water circulated inside the support was changed to 25 ° C., and the photosensitive member was irradiated with ultraviolet rays without applying cold air to the photosensitive member. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the initial surface temperature was 25 ° C., the maximum temperature reached 37 ° C., and the temperature increase range was 12 ° C.

(Example 7)
In Example 6, the radically polymerizable compound having a charge transporting structure contained in the coating solution for the crosslinked surface layer was exemplified by Compound No. 1. 109 (molecular weight: 445, functional group number: 1 functional). Further, all the steps were performed except that the temperature of water circulating inside the support was 40 ° C., the initial temperature of the photoreceptor surface was 40 ° C., the maximum temperature reached 52 ° C., and the temperature increase range was 12 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

(Example 8)
In Example 6, 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 (dipentaerythritol hexaacrylate). Furthermore, all the steps were performed except that the temperature of water circulating inside the support was 43 ° C., the initial temperature of the photoreceptor surface was 43 ° C., the maximum temperature reached 55 ° C., and the temperature increase range was 12 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1.
Dipentaerythritol hexaacrylate (Mix 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 9
In Example 1, the trifunctional or higher functional radical polymerizable monomer having no charge transport structure contained in the crosslinked surface layer coating solution was changed to the following material (caprolactone-modified dipentaerythritol hexaacrylate). Except that, an electrophotographic photosensitive member was produced in the same manner as in Example 1.
・ 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 cold air applied at the time of ultraviolet irradiation was changed to 30 ° C., the initial temperature was 37 ° C., the maximum temperature reached 54 ° C., and the temperature increase range was 17 ° C. A photographic photoreceptor was prepared.

(Comparative Example 2)
In Example 1, ultraviolet rays were irradiated to the photoconductor without applying cold air, the initial temperature was 37 ° C., the maximum temperature reached 60 ° C., and the temperature increase range was 23 ° C. All in the same manner as in Example 1. An electrophotographic photosensitive member was produced.

(Comparative Example 3)
In Example 1, 37 ° C. circulating water was allowed to flow in a state where a 1.0 mm rubber sheet was in close contact with the inside of the support, and ultraviolet rays were irradiated without applying cold air to the photoconductor. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature was 65 ° C. and the temperature increase was 28 ° C.

(Comparative Example 4)
In Example 1, the irradiation intensity of ultraviolet rays was changed to 1000 mW / cm ² , the initial temperature was 37 ° C., the maximum temperature reached 55 ° C., and the temperature increase range was 18 ° C. An electrophotographic photosensitive member was produced.

(Comparative Example 5)
In Example 1, the temperature of the water circulated inside the support was changed to 30 ° C., the cold air applied during UV irradiation was changed to 30 ° C., the initial temperature was set to 30 ° C., the maximum reached temperature was set to 47 ° C., and the temperature increase range was 17 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that.

(Comparative Example 6)
In Example 1, the temperature of the water circulated inside the support is changed to 20 ° C., the cool air applied to the surface of the photoreceptor is eliminated, the initial temperature is 30 ° C., the maximum temperature reached is 47 ° C., and the temperature rise is 17 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that.

(Comparative Example 7)
In Example 1, the ultraviolet irradiation intensity was changed to 650 mW / cm ² , a rubber sheet of 0.5 mm was brought into close contact with the inside of the support, the circulating water was 25 ° C., the initial temperature was 25 ° C., and the maximum temperature reached An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature was 42 ° C. and the temperature increase range was 17 ° C.

(Comparative Example 8)
In Example 1, the irradiation intensity of ultraviolet rays was changed to 650 mW / cm ² , a rubber sheet of 0.5 mm was adhered inside the support, the circulating water was set to 40 ° C., the initial temperature was 40 ° C., and the maximum reached temperature was An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the temperature was 57 ° C. and the temperature increase was 17 ° C.

(Comparative Example 9)
In Example 1, ultraviolet rays were irradiated without flowing water into the support and without applying cold air, except that the initial temperature was 20 ° C., the maximum temperature reached 68 ° C., and the temperature increase range was 48 ° C. An electrophotographic photosensitive member was produced in the same manner as in Example 1.

(Comparative Example 10)
In Example 1, water was not flowed into the support, the cold air applied to the photoreceptor was changed to 20 ° C., the initial temperature was 20 ° C., the maximum reached temperature was 52 ° C., and the temperature rise was 31 ° C. Were prepared in the same manner as in Example 1 to produce an electrophotographic photoreceptor.

(Comparative Example 11)
In Example 1, the thickness of the charge transport layer was 28 μm, and an electrophotographic photosensitive member was produced without providing a crosslinked surface layer.

  The photoconductor produced as described above uses a Ricoh-made Imagio MF7070 machine with the development unit and transfer belt removed, and the initial dark portion potential is set to -800 V, and charging and discharging processes are performed for 24 hours to accumulate fatigue. It was. Further, 100,000 sheets (A4) were passed using an Imagio Neo1050Pro manufactured by Ricoh. In the present invention, the initial portion and the exposed portion potential after fatigue and paper passing, the measurement of the wear amount, and the image evaluation were performed. The amount of wear due to paper passing was calculated by measuring the film thickness of the photoreceptor before and after paper passing using an eddy current film thickness measuring device (manufactured by Fischer Instruments). Table 5 shows the results.

  From the results of Table 5, in Examples 1 to 9, the increase in the potential of the exposed portion was small even in the paper passing test after electrostatic fatigue, and no decrease in the image density was observed. In Examples 1 to 9, the amount of wear is small, and an improvement in wear resistance can be expected. On the other hand, in Comparative Examples 1 to 10 in which the temperature increase range was larger than 15 ° C., the exposed portion potential was greatly increased in the paper passing test after fatigue, and the density was reduced in the image. In Comparative Example 11 in which no cross-linked surface layer was provided, the amount of wear was large and high wear resistance could not be expected.

Accordingly, in the method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer is a crosslinked surface layer cured by irradiating with light energy. The electrophotographic photosensitive member produced by the method for producing an electrophotographic photosensitive member, characterized in that the temperature rise of the photosensitive member surface temperature is within 15 ° C., has good electrical characteristics and high durability, and has high quality. An electrophotographic photosensitive member capable of maintaining a stable image has been realized.
Further, it has been clarified that the image forming process, the image forming apparatus, and the process cartridge for the image forming apparatus using the photoconductor of the present invention have high performance and high reliability.

It is a figure which shows the relationship between light energy irradiation time and a photoreceptor surface temperature. 1 is a cross-sectional view illustrating an example of an electrophotographic photosensitive member of the present invention. It is sectional drawing which shows the other example of the electrophotographic photoreceptor of this invention. 1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention. FIG. 2 is a schematic diagram illustrating an example of a process cartridge for an image forming apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger 4 Eraser 5 Image exposure part 6 Developing unit 7 Pre-transfer charger 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation charger 12 Separation claw 13 Pre-cleaning charger 14 Fur brush 15 Cleaning blade 101 Photosensitive drum 102 Charging device 103 Exposure 104 Developing device 105 Transfer body 106 Transfer device 107 Cleaning blade

Claims (15)

In the method for producing an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the surface layer of the photosensitive layer is a crosslinked surface layer cured by irradiating light energy, A method for producing an electrophotographic photosensitive member, wherein the body surface temperature rises within 15 ° C. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the maximum temperature reached on the surface of the photosensitive member when the crosslinked surface layer is formed is 40 [deg.] C. or higher. The method for producing an electrophotographic photosensitive member according to claim 1, wherein an initial temperature of the surface of the photosensitive member at the time of forming the crosslinked surface layer is 40 ° C. or less. An electrophotographic photosensitive member produced by the method for producing an electrophotographic photosensitive member according to claim 1. The crosslinked surface layer is
(A) a tri- or more functional radical polymerizable monomer having no charge transporting structure;
(B) a radically polymerizable compound having a charge transporting structure;
The electrophotographic photosensitive member according to claim 4, comprising: 6. The electrophotographic photoreceptor according to claim 5, wherein 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 photosensitive member according to claim 5 or 6, wherein the charge transporting structure (b) is a triarylamine structure. The electrophotographic image according to any one of claims 5 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 5, wherein the radically polymerizable compound (b) has one functional group. 10. The trifunctional or higher functional radical polymerizable monomer (i) has three or more functional groups selected from the group consisting of acryloyloxy groups and methacryloyloxy groups. The electrophotographic photosensitive member according to any one of the above. The electrophotographic photosensitive member according to claim 4, wherein the crosslinkable surface layer contains a photopolymerization initiator. The electrophotographic photosensitive member according to claim 4, wherein the photosensitive layer has a stacked structure of a charge generation layer and a charge transport layer from the conductive support side. An electrophotographic photosensitive member; an electrostatic latent image forming unit that forms an electrostatic latent image on the electrophotographic photosensitive member; and a developing unit that develops the electrostatic latent image with toner to form a visible image. An image forming apparatus comprising: a transfer unit that transfers the visible image to a recording medium; and a fixing unit that fixes the transfer image transferred to the recording medium, wherein the electrophotographic photosensitive member comprises: 12. An image forming apparatus comprising the electrophotographic photosensitive member according to any one of the items 12. An electrostatic latent image forming step of forming an electrostatic latent image on an electrophotographic photosensitive member; a developing step of developing the electrostatic latent image with toner to form a visible image; and 13. An image forming method comprising a transfer step of transferring to a recording medium and a fixing step of fixing the transferred image transferred to the recording medium, wherein the electrophotographic photosensitive member is any one of claims 4 to 12. An image forming method characterized by being an electrophotographic photosensitive member. It comprises at least one of an electrostatic latent image forming unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit, and the electrophotographic photosensitive member according to any one of claims 4 to 12. Process cartridge.

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