JP5510101B2 - Electrophotographic photosensitive member, and image forming apparatus and process cartridge using the same - Google Patents

Description

  The present invention provides a surface protection that has high wear resistance and excellent toner releasability, and that can particularly suppress the occurrence of abnormal images due to the adhesion of hydrophobic silica contained in the toner over a long period of time. The present invention relates to an electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time as well as having excellent durability, and an image forming apparatus and a process cartridge using the electrophotographic photosensitive member.

  Conventionally, an organic photoreceptor (OPC) has been widely used in a copying machine, a facsimile machine, a laser printer, and a composite machine thereof in place of an inorganic photoreceptor because of various advantages. The reasons are, for example, (1) optical characteristics such as the light absorption wavelength range and the amount of absorption, (2) electrical characteristics such as high sensitivity and stable charging characteristics, and (3) material selection range. (4) Ease of manufacturing, (5) Low cost, (6) Non-toxicity, and the like.

  Recently, the diameter of the photoconductor has 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, organic photoreceptors are generally soft because the surface layer is mainly composed of low molecular charge transport materials and inert polymers, and when used repeatedly in an electrophotographic process, the organic photoreceptors depend on development systems and cleaning systems. There is a drawback that wear is likely to occur due to a mechanical load. In addition, due to the demand for high 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 toner particle size is reduced. This also promotes the wear of the photoreceptor. It is a factor. Such wear of the photoreceptor deteriorates electrical characteristics such as sensitivity deterioration and chargeability, and causes abnormal images such as image density reduction and background stains. In addition, scratches in which wear locally occurs result in streak-like stain images due to poor cleaning.

  In order to increase the durability of the organic photoreceptor, it is indispensable to reduce the amount of wear, but it is also required to increase the toner releasability as a means for further improving the cleaning performance. In particular, when the hydrophobic silica contained on the surface of the toner adheres to the photoreceptor due to a decrease in the amount of wear, it is very difficult to remove the adhered silica. And the toner component adheres to the surface of the photoconductor, leading to the occurrence of abnormal images that appear in the image, and has a good surface with both wear resistance and high releasability. There is a need for an organophotoreceptor that has properties.

  For example, (1) an epoxy acrylate resin having bisoxyethylenated bisphenol A diacrylate as a main unit on the surface of an image holding member and silicone as a technique for achieving both wear resistance and high releasability on the surface of the photoreceptor. Containing a leveling agent (see Patent Document 1), (2) containing a compound obtained by polymerizing an antioxidant, a deterioration inhibitor, a light-shielding agent or a lubricant having a cured chain polymerizable functional group and a silicon atom in the surface protective layer (3) Radical polymerization of a tri- or higher functional group in which a copolymer containing polyorganosiloxane as a constituent component is dispersed in the surface layer, and the surface layer does not have at least a charge transporting structure. Using a cross-linked resin layer obtained by curing a monofunctional radically polymerizable compound having a charge transporting structure and a charge transporting structure (see Patent Document 3), (4) Containing 10% by mass or more of fluororesin fine particles so that the contact angle with the pure water on the outer layer surface is 100 ° or more (see Patent Document 4), (5) A concave surface having a dimple-shaped peripheral surface of the electrophotographic photosensitive member (6) The photosensitive layer has a polyester resin having a specific structural unit, and a carbon number of 20 formed by an ester bond between a carboxylic acid and an alcohol. The thing containing -150 wax (refer patent document 6), etc. are mentioned.

  However, none of these prior art documents have sufficiently satisfied the durability required for maintaining the mechanical durability and high releasability required for the organic photoreceptor for a long period of time. .

  Therefore, a surface protective layer having high wear resistance and excellent toner releasability, and capable of suppressing the occurrence of abnormal images due to the adhesion of hydrophobic silica contained in the toner over a long period of time. An electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time, as well as excellent durability, and an image forming apparatus and a process cartridge using the electrophotographic photosensitive member are still provided. There is no current situation.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention has high wear resistance and excellent toner releasability, and in particular, it is possible to suppress the occurrence of abnormal images and the like due to adhesion of hydrophobic silica contained in the toner over a long period of time. By providing a surface protective layer, an electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time as well as excellent durability, and an image forming apparatus and a process cartridge using the electrophotographic photosensitive member are provided. The purpose is to do.

Means for solving the problems are as follows. That is,
<1> A support and, on the support, at least a photosensitive layer and a surface protective layer,
The surface protective layer is an epoxy acrylate compound represented by at least one of the following general formulas (I) and (II), a trifunctional or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure; An electrophotographic photosensitive member characterized by containing a cured product of:
However, in said general formula (I), R < ¹ > and R < ² > both represent either a hydrogen atom or a methyl group. n represents an integer of 1 to 3.
However, in said general formula (II), R < ¹ > represents either a hydrogen atom or a methyl group.
<2> The electrophotographic photosensitive member according to <1>, wherein the epoxy acrylate compound represented by the general formula (I) is an epoxy acrylate compound represented by the following structural formula.
<3> The electrophotographic photosensitive member according to <1>, wherein the epoxy acrylate compound represented by the general formula (II) is an epoxy acrylate compound represented by the following structural formula.
<4> The electrophotographic photosensitive material according to any one of <1> to <3>, wherein the content of the epoxy acrylate compound is 5 parts by mass to 100 parts by mass with respect to 100 parts by mass of the tri- or higher functional radical polymerizable compound. Is the body.
<5> The electrophotographic photosensitive member according to any one of <1> to <4>, wherein the surface protective layer contains a filler.
<6> The electrophotographic photosensitive member according to any one of <1> to <5>, and at least one unit selected from a charging unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. The process cartridge is detachable from the image forming apparatus main body.
<7> An electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, exposure means for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image, and the electrostatic latent image At least developing means for developing an image using toner to form a visible image, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transferred image transferred to the recording medium An image forming apparatus having
An electrophotographic photosensitive member according to any one of <1> to <5>, wherein the electrophotographic photosensitive member is an image forming apparatus.
<8> The image forming apparatus according to <7>, wherein the toner includes at least hydrophobic silica having a primary average particle diameter of 100 nm to 200 nm on a surface thereof.

In the electrophotographic photoreceptor of the present invention, the surface protective layer contains a cured product of a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure, High wear resistance and high releasability can be realized.
As such a specific epoxy acrylate compound, an epoxy acrylate compound having an aliphatic compound having no cyclic structure in the compound and having at least two or more hydroxyl groups in the compound is used. As a result, it was found that high releasability can be obtained particularly over a long period of time. In particular, an excellent effect can be obtained in suppressing abnormal images caused by the hydrophobic silica having a primary average particle size of 100 nm to 200 nm added to the toner surface adhering to the surface protective layer.
Although the reason is not clear, it is presumed that the following effects are obtained. That is, hydrophobic silica with a primary average particle size of 100 nm to 200 nm contained in the toner plays an effective role in the fluidity and charging characteristics of the toner, but the amount of hydroxyl groups on the surface of the hydrophobic silica is small and the carbon component is increased. Therefore, the polarity of silica is considered to be small. Further, since the polarity of the commonly used photoreceptor surface is small and has properties similar to hydrophobic silica, it is considered that hydrophobic silica is likely to adhere to the photoreceptor surface. In contrast, the specific epoxy acrylate compound used in the present invention is an aliphatic compound having no cyclic structure in the compound, so that the hydrogen groups contained in the compound are densely distributed on the outermost surface. It is considered that the polarity is increased. Therefore, the adhesion force with the low-polarity hydrophobic silica is reduced, and it is considered that the hydrophobic silica is less likely to adhere to the surface of the photoreceptor in the photoreceptor of the present invention.
In addition, by using a tri- or higher functional radical polymerizable compound, a three-dimensional network structure is actively developed by a curing reaction, and a surface protective layer having a high crosslinking density is obtained, thereby achieving high wear resistance. Furthermore, since the crosslinking reaction with the epoxy acrylate compound is actively performed, it becomes possible to uniformly distribute the hydroxyl groups in the epoxy acrylate compound in the network structure, so that both high release properties and wear resistance are compatible. It became possible.
In addition, the formation of the surface protective layer in the electrophotographic photosensitive member of the present invention is performed by using a composition containing a radical polymerizable compound having a charge transporting structure in addition to a specific epoxy acrylate compound and a tri- or higher functional radical polymerizable compound. These are cured at the same time in a short time to form a high-hardness cross-linked bond, and the durability is improved. Furthermore, since a radically polymerizable compound having a charge transporting structure is incorporated in the surface protective layer, stable electrical characteristics can be obtained over a long period of time. On the other hand, when a low molecular charge transport material having no functional group is contained in the surface protective layer, precipitation of the low molecular charge transport material and white turbidity occur due to its low compatibility, and the surface protective layer machine The mechanical strength also decreases, and the sensitivity is lowered due to charge trapping and the residual potential is increased. In addition, when a charge transporting compound having two or more functional groups is used, the charge transporting structure is very bulky, so that the internal stress of the surface protective layer is increased, distortion occurs in the cured resin, and cracks and scratches are generated. Although there was a problem of frequent occurrence, linear saturated aliphatic hydrocarbon groups present in the surface protective layer relieve internal stress, and it became possible to suppress the occurrence of cracks and scratches .
Therefore, according to the present invention, the surface protective layer is formed by polymerizing a specific epoxy acrylate compound, a tri- or higher-functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure. It is possible to provide an electrophotographic photosensitive member capable of maintaining high image quality while improving abrasion and obtaining high releasability over a long period of time.

  According to the present invention, conventional problems can be solved, wear resistance is high, toner releasability is excellent, and abnormal images due to adhesion of hydrophobic silica contained in the toner are generated for a long time. By using a surface protective layer that can be suppressed over a long period of time, an electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time, as well as excellent durability, and the electrophotographic photosensitive member are used. Image forming apparatus and process cartridge can be provided.

FIG. 1 is a schematic view showing an example of the electrophotographic photosensitive member of the present invention. FIG. 2 is a schematic view showing an example of the electrophotographic photosensitive member of the present invention. FIG. 3 is a schematic view showing an example of the image forming apparatus of the present invention. FIG. 4 is a schematic view showing an example of the process cartridge of the present invention.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor of the present invention comprises a support and at least a photosensitive layer and a surface protective layer on the support, and further comprises other layers as necessary.

<Surface protective layer>
The surface protective layer contains a cured product of a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, a radical polymerizable compound having a charge transporting structure, and preferably a polymerization initiator, a filler, Further, it contains other components as required.

-Epoxy acrylate compound-
As the epoxy acrylate compound, an epoxy acrylate compound represented by at least one of the following general formulas (I) and (II) is used.
However, in said general formula (I), R < ¹ > and R < ² > both represent either a hydrogen atom or a methyl group. n represents an integer of 1 to 3.
However, in said general formula (II), R < ¹ > represents either a hydrogen atom or a methyl group.

In the present invention, among the epoxy acrylate compounds, epoxy acrylate compounds represented by the following structural formula are particularly preferable in that they are effective in suppressing abnormal images caused by adhesion of hydrophobic silica.

The epoxy acrylate compound is composed of a reaction product of an acrylic acid derivative such as acrylic acid or methacrylic acid and an epoxy resin as a raw material compound, and an appropriately synthesized product or a commercially available product may be used. May be.
There is no restriction | limiting in particular as said commercial item, According to the objective, it can select suitably, For example, epoxy ester 40EM, epoxy ester 70PA, epoxy ester 200PA, epoxy ester 80MFA (all are the Kyoeisha Chemical Co., Ltd. product), etc. Is mentioned. Among these, epoxy ester 70PA and epoxy ester 80MFA are particularly preferable from the viewpoint of the effect of suppressing abnormal images caused by adhesion of hydrophobic silica.

  The content of the epoxy acrylate compound is preferably 5 parts by mass to 100 parts by mass with respect to 100 parts by mass of the tri- or higher functional radical polymerizable compound from the viewpoint of a balance between wear resistance and high releasability. -40 mass parts is more preferable. If the content is less than 5 parts by mass, the releasability may be reduced. If the content exceeds 100 parts by mass, the wear resistance is reduced and the life of the electrophotographic photosensitive member is reduced. May end up.

-3 functional or higher radical polymerizable compound The trifunctional or higher functional radical polymerizable compound is, for example, a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, such as condensed polycyclic quinone, diphenoquinone, cyano group, It means a compound having no electron transport structure such as an electron-withdrawing aromatic ring having a nitro group and having three or more radical polymerizable functional groups.

  The radical polymerizable functional group may be any group having a carbon-carbon double bond and 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) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formulas.
However, in said formula, X1 is an arylene group such as a phenylene group optionally having a substituent, a naphthylene group, an alkenylene group optionally having a substituent, a —CO— group, a —COO— group, —CON (R ¹⁰ ) — group (R ¹⁰ represents an alkyl group such as a hydrogen atom, a methyl group or an ethyl group, an aralkyl group such as a benzyl group, a naphthylmethyl group or a phenethyl group, or an aryl group such as a phenyl group or a naphthyl group. Or S-group.
Specific examples of these substituents include vinyl group, styryl group, 2-methyl-1,3-butadienyl group, vinylcarbonyl group, acryloyloxy group, acryloylamide group, vinylthioether group, and the like.

(2) Examples of 1,1-substituted ethylene functional groups include functional groups represented by the following formulas.
CH ₂ = _{CY-X 2} -
In the above formula, Y is an aryl group such as an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group. Group, halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ⁷⁹ group (where R ⁷⁹ is a hydrogen atom, an optionally substituted methyl group, ethyl group, etc. An alkyl group, an aralkyl group such as benzyl or phenethyl group which may have a substituent, an aryl group such as a phenyl group or naphthyl group which may have a substituent, or -CONR ⁸⁰ R ⁸¹ (however, R ⁸⁰ and R ⁸¹ are hydrogen atoms, which may have a substituent an alkyl group such as methyl group and ethyl group, which may have a substituent group benzyl group, naphthylmethyl group or Fene, Aralkyl groups such as group, or a substituent a phenyl group which may have a represents an aryl group such as a naphthyl group, may be the same or different from each other.) Further, X ₂ is X ₁ in the above formula And the same substituent, a single bond, and an alkylene group, provided that at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, and an aromatic ring.

  Specific examples of these substituents include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

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

The trifunctional or higher functional radical polymerizable compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, HPA-modified trimethylolpropane triacrylate. Acrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, HPA-modified trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate , ECH modified glycerol triacrylate, EO modified glycerol triacrylate, PO modified group Serol triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, alkyl-modified dipenta Erythritol tetraacrylate, alkyl-modified dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, EO-modified phosphoric acid triacrylate, 2,2,5,5-tetrahydroxymethylcyclopentanone tetra Acrylate, and the like. These may be used individually by 1 type and may use 2 or more types together.
The content of the trifunctional or higher functional radical polymerizable compound is preferably 30 parts by mass to 70 parts by mass with respect to the total amount of the surface protective layer from the viewpoint of wear resistance and electrical characteristics. If the content is less than 30 parts by mass, the wear resistance may be reduced, and if it exceeds 70 parts by mass, the charge transport property may be reduced.
The surface protective layer contains a cured product of at least a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure. For the purpose of imparting a function, a radical polymerizable compound, a functional monomer, and a radical polymerizable oligomer can be used in combination.

  There is no restriction | limiting in particular as said radically polymerizable compound, According to the objective, it can select suitably, For example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl Carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxytriethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3 -Butanediol diacrylate, 1,4-butanediol diacrylate, 1, -Butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, bisphenol A-EO modified diacrylate, bisphenol F-EO modified diacrylate, And neopentyl glycol diacrylate.

There is no restriction | limiting in particular as said functional monomer, According to the objective, it can select suitably, For example, octafluoropentyl acrylate, 2-perfluoro octyl ethyl acrylate, 2-perfluoro octyl ethyl methacrylate, 2-perfluoro A reactive additive having a fluorine atom substituted such as isononylethyl acrylate or a radical polymerizable functional group, for example, a reactive silicone-based additive such as PO-modified-2-neopentylglycol diacrylate can be used effectively. . These functional monomers may be used alone or in combination of two or more.
The content of the radical polymerizable compound or the functional monomer is preferably 0.01 to 30 parts by mass, and 0.05 to 20 parts by mass with respect to the solid content of the coating liquid forming the surface protective layer. More preferred.
The radical polymerizable oligomer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include urethane acrylate oligomers and polyester acrylate oligomers.
However, when a large amount of monofunctional and bifunctional radically polymerizable compounds, functional monomers, and radically polymerizable oligomers are contained, the three-dimensional cross-linking density of the surface protective layer is substantially reduced, resulting in a decrease in wear resistance. There is a fear. For this reason, 100 parts by mass or less is preferable with respect to 100 parts by mass of the tri- or higher functional radical polymerizable compound used in the present invention.

-Radical polymerizable compound with charge transport structure-
The radical polymerizable compound having a charge transporting structure means a compound having a hole transporting structure or an electron transporting structure and having a radical polymerizable functional group.
Examples of the hole transporting structure include triarylamine, hydrazone, pyrazoline, carbazole, and the like.
Examples of the electron transporting structure include condensed polycyclic quinone, diphenoquinone, cyano group, and nitro group.
The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization, and the radical functional group is preferably monofunctional or bifunctional.
The radical polymerizable compound having a charge transporting structure is polymerized by opening a carbon-carbon double bond on both sides, so that it does not become a terminal structure but is incorporated into a chain polymer and crosslinked. In a polymer, it exists in the main chain of a polymer and exists in a cross-linked chain between the main chain and the main chain (this cross-linked chain includes an intermolecular cross-linked chain between one polymer and another polymer). There is an intramolecular cross-linked chain in which a part of a main chain folded in one polymer and another part derived from a polymerized monomer are cross-linked in a position away from the main chain) It may be either present in the main chain or present in the cross-linked chain. Further, the radical polymerizable compound having a charge transporting structure having a triarylamine structure has at least three aryl groups arranged in a radial direction from a nitrogen atom suspended from the chain part, and is a bulky, but in the chain part. Since they are not directly bonded but suspended from the chain part via a carbonyl group, etc., they are fixed in a flexible manner in steric positioning. Since adjacent spatial arrangement is possible, there is little structural distortion in the molecule, and when it is used as a protective layer for an electrophotographic photoreceptor, it can have an intramolecular structure that is relatively free from interruption of the charge transport path. Presumed to be.

Specific examples of the charge transporting compound having a radical polymerizable functional group having a triarylamine structure as a charge transporting structure are shown below, but are not limited to the compounds having these structures.

  The radical polymerizable compound having the charge transport structure is important for imparting charge transport performance to the surface protective layer, and the content of the radical polymerizable compound having the charge transport structure is the total amount of the surface protective layer. 20 mass parts-80 mass parts are preferable with respect to 30 mass parts-70 mass parts. When the content is less than 20 parts by mass, the charge transport performance of the surface protective layer cannot be sufficiently maintained, and deterioration of electrical characteristics such as a decrease in sensitivity and an increase in residual potential may appear due to repeated use. If it exceeds the mass part, the crosslink density of the surface protective layer is lowered and the releasability is reduced, and high wear resistance and releasability are not exhibited. Although the electrical characteristics and abrasion resistance required differ depending on the process used, it cannot be said unconditionally, but the range of 30 parts by mass to 70 parts by mass is most preferable in consideration of the balance of both characteristics.

-Polymerization initiator-
The surface protective layer contains a cured product of at least a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure. In order to proceed well, a polymerization initiator may be used.
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator, and a photopolymerization initiator is preferable from the viewpoint of polymerization efficiency.

  The thermal polymerization initiator is not particularly limited and may be appropriately selected depending on the purpose. For example, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t -Butyl cumyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, etc. Peroxide initiators such as: azobisisobutyronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, azo initiators such as 4,4′-azobis-4-cyanovaleric acid, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.

  The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 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-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o -Ethoxycarbonyl) oxime and other acetophenone or ketal photoinitiators; benzoin, benzoin methyl ether Benzoin ether photopolymerization initiators such as benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyl Benzophenone photopolymerization initiators such as phenyl ether, acrylated benzophenone, 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4- And thioxanthone photopolymerization initiators such as dichlorothioxanthone.

Examples of other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl) phenyl. Phosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compound, triazine compound, imidazole compound, etc. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together.
In addition, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.
The content of the polymerization initiator is preferably 0.5 parts by mass to 40 parts by mass, and more preferably 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the total content having radical polymerizability.

-Filler-
The surface protective layer contains a cured product of at least a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure. It is preferable to contain a filler for the purpose of improving wear resistance.
As the filler, either an organic filler or an inorganic filler is used.
Examples of the organic filler include fluororesin powder such as polytetrafluoroethylene; silicone resin powder, a-carbon powder, and the like. Examples of the inorganic filler include metal powders such as copper, tin, aluminum, and indium; doped with silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, and antimony. Metal oxides such as tin oxide and tin-doped indium oxide; metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride; potassium titanate and boron nitride. Among these, from the viewpoint of the hardness of the filler, the use of an inorganic filler is advantageous for improving the wear resistance.

The average primary particle size of the filler is preferably 0.01 μm to 0.5 μm from the viewpoint of light transmittance and wear resistance of the surface protective layer. When the average primary particle size of the filler is less than 0.01 μm, the dispersibility may be lowered, and the effect of improving wear resistance may not be sufficiently exhibited. When the average primary particle size exceeds 0.5 μm, the surface protective layer In the dispersion liquid, sedimentation of the filler may be promoted or toner filming may occur.
The higher the content of the filler in the surface protective layer, the better the wear resistance is, but if it is too high, the residual potential increases, the writing light transmittance of the surface protective layer decreases, and side effects occur. There is. Therefore, 50 parts by mass or less is preferable, and 30 parts by mass or less is more preferable.
The filler can be surface-treated with at least one kind of surface treatment agent, and it is preferable to do so from the viewpoint of dispersibility of the filler. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem.
There is no restriction | limiting in particular as said surface treating agent, Although all the surface treating agents used conventionally can be used, It is preferable that it is a surface treating agent which can maintain the insulation of a filler.
The amount of the surface treatment agent used varies depending on the average primary particle size of the filler used and cannot be specified unconditionally, but is preferably 3 parts by mass to 30 parts by mass with respect to 100 parts by mass of the filler, and 5 parts by mass to 20 parts by mass. Part by mass is more preferable. If the amount of the surface treatment agent used is less than this, the filler dispersing effect cannot be obtained, and if it is too much, the residual potential may be significantly increased.

The surface protective layer coating liquid may contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement) and a leveling agent, if necessary. Known additives can be used for these additives.
As the plasticizer, for example, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used. The amount of the plasticizer used is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, based on the total solid content of the surface protective layer coating solution.
Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. The amount of the leveling agent used is preferably 3 parts by mass or less based on the total solid content of the surface protective layer coating solution.
The surface protective layer is a surface protective layer coating solution containing at least a specific epoxy acrylate compound, a tri- or higher functional radical polymerizable compound, a radical polymerizable compound having a charge transporting structure, and preferably a polymerization initiator. Can be formed by applying and curing.
The surface protective layer coating solution is diluted with a solvent and applied as necessary.
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohol solvents such as methanol, ethanol, propanol and butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Ester solvents such as ethyl acetate and butyl acetate; Ether solvents such as tetrahydrofuran, dioxane and propyl ether; Halogen solvents such as dichloromethane, dichloroethane, trichloroethane and chlorobenzene; Aromatic solvents such as benzene, toluene and xylene; Methyl cellosolve And cellosolve solvents such as ethyl cellosolve and cellosolve acetate. These may be used individually by 1 type and may use 2 or more types together.
In addition, the dilution rate with the said solvent changes with the solubility of a composition, the coating method, the thickness of the target surface protective layer, etc., and can be selected suitably.
The application can be performed, for example, by dip coating, spray coating, bead coating, ring coating, or the like.

After applying the surface protective layer coating liquid, energy is applied from the outside and cured to form a surface protective layer. The external energy includes heat, light, and radiation.
The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves.
The heating temperature is preferably 100 ° C. or higher and 170 ° C. or lower. When the heating temperature is less than 100 ° C., the reaction rate is slow and the reaction may not be completed completely. When the heating temperature exceeds 170 ° C., the reaction proceeds non-uniformly and a large distortion occurs in the surface protective layer. . In order to advance the curing reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 100 ° C. and then heating to 100 ° C. or more. As the light energy, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in ultraviolet light (UV) can be used. A light source can also be selected.
The irradiation light amount is preferably 50 mW / cm ² or more and 1,000 mW / cm ² or less. If the irradiation light amount is less than 50 mW / cm ² , it may take time for the curing reaction. If it exceeds 1,000 mW / cm ² , the progress of the reaction becomes uneven and the surface protective layer becomes rough. Sometimes. Examples of radiation energy include those using electron beams (EB). Among these energies, those using heat and light energy are useful because of the ease of reaction rate control and the simplicity of the apparatus.
Since the thickness of the surface protective layer may vary depending on the layer structure of the photosensitive layer of the photoreceptor in which the surface protective layer is used, it will be described in the following description of the layer structure of the electrophotographic photoreceptor.

<Layer structure of electrophotographic photoreceptor>
The layer structure of the electrophotographic photosensitive member of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of the electrophotographic photosensitive member of the present invention. The photosensitive layer has a single layer structure in which a photosensitive layer 202 having a charge generating function and a charge transporting function is provided on a support 201 at the same time. The structure in which the surface protective layer 203 is provided on the surface is shown.
In FIG. 2, a surface protective layer 203 is provided on the surface of a photosensitive layer having a laminated structure in which a charge generation layer 204 having a charge generation function and a charge transport layer 205 having a charge transport function are stacked on a support 201. The configuration is shown.

<Support>
The support is not particularly limited as long as it has a volume resistance of 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. For example, aluminum, nickel, chromium, nichrome, copper Metals such as gold, silver and platinum; metal oxides such as tin oxide and indium oxide coated with film or cylindrical plastic, paper, or aluminum, aluminum alloy, nickel by vapor deposition or sputtering It is possible to use a plate made of stainless steel or the like and a tube subjected to surface treatment such as cutting, superfinishing, polishing, etc. after forming them into a raw tube by a method such as extruding and drawing them. Further, an endless nickel belt and an endless stainless steel belt disclosed in JP-A-52-36016 can also be used as a support.
Moreover, what coated and disperse | distributed conductive powder to the appropriate binder resin on the said support body can also be used as a support body.
Examples of the conductive powder include carbon black, acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver; metal oxide powder such as conductive tin oxide and ITO. It is done. Examples of the binder resin used simultaneously include polystyrene resin, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester resin, polyvinyl chloride resin, vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetate resin, polyvinylidene chloride resin, polyarylate resin, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl toluene resin, poly-N-vinyl carbazole , Acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and the like. These may be used individually by 1 type and may use 2 or more types together.
The conductive layer can be provided by applying a coating liquid in which these conductive powder and binder resin are dispersed in a solvent.
Examples of the solvent include tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene, and the like.
Further, a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as a support.

<Photosensitive layer>
The photosensitive layer may have a laminated structure or a single layer structure.
When the photosensitive layer has a laminated structure, the photosensitive layer includes a charge generation layer having a charge generation function and a charge transport layer having a charge transport function. When the photosensitive layer has a single layer structure, the photosensitive layer is a layer having both a charge generation function and a charge transport function.
Hereinafter, each of the photosensitive layer having a laminated structure and the photosensitive layer having a single layer structure will be described.

<Photosensitive layer of laminated structure>
(1) Charge generation layer The charge generation layer contains at least a charge generation substance, and contains a binder resin and, if necessary, other components.
As the charge generation material, inorganic materials and organic materials can be used.
The inorganic material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, amorphous silicon Etc. In the amorphous-silicon, those obtained by terminating dangling bonds with hydrogen atoms or halogen atoms, or those doped with boron atoms, phosphorus atoms or the like are preferably used.

  The organic material is not particularly limited and may be appropriately selected from known materials according to the purpose. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azurenium salt pigments, squaric acid methine Pigment, azo pigment having carbazole skeleton, azo pigment having triphenylamine skeleton, azo pigment having diphenylamine skeleton, azo pigment having dibenzothiophene skeleton, azo pigment having fluorenone skeleton, azo pigment having oxadiazole skeleton, bis Azo pigments having a stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyryl carbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenyl Enirumetan pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, a polyamide resin, a polyurethane resin, an epoxy resin, a polyketone resin, a polycarbonate resin, a silicone resin, an acrylic resin, a polyvinyl butyral resin, polyvinyl Formal resin, polyvinyl ketone resin, polystyrene resin, poly-N-vinyl carbazole resin, polyacrylamide resin, and the like can be given. These may be used individually by 1 type and may use 2 or more types together.
In addition to the binder resin described above, the charge generation layer binder resin may be a polymer charge transport material having a charge transport function, such as (1) an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, or a stilbene. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin having a skeleton and a pyrazoline skeleton, and (2) a polymer material having a polysilane skeleton can be used.
Specific examples of the above (1) include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559. JP, 04-011627, JP 04-175337, JP 04-183719, JP 04-22514, JP 04-230767, JP 04-320420, JP 05-232727, JP 05-310904, JP 06-234836, JP 06-234837, JP 06-234838, JP 06-234839, JP JP 06-234840, JP 06-234841 A, JP 06-239049 A Distribution, JP-06-236050, JP-A No. 06-2
No. 36051, No. 06-295077, No. 07-056374, No. 08-176293, No. 08-208820, No. 08-212640, No. 08-253568. JP-A-08-269183, JP-A-09-062019, JP-A-09-043883, JP-A-09-71642, JP-A-09-87376, JP-A-09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 09-227669, JP 09-235367, JP JP 09-241369, JP 09-268226, JP 09-09. 72735, JP-A No. 09-302084, JP-A No. 09-302085 discloses a charge transport polymer material described in JP-A 09-328539 discloses the like.
Specific examples of the above (2) include, for example, those described in JP-A-63-285552, JP-A-05-19497, JP-A-05-70595, JP-A-10-73944, and the like. Examples are polysilylene polymers.
The charge generation layer may contain a low molecular charge transport material.

Examples of the low molecular charge transport material include an electron transport material and a hole transport material.
The electron transport material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, chloroanil, bromilyl, 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-trinitrodibenzothiophene-5,5-dioxide, diphenoquinone derivatives and the like. These may be used individually by 1 type and may use 2 or more types together.

  The hole transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, and triarylamine derivatives. , Stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc. Derivatives, enamine derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

The method for forming the charge generation layer is roughly classified into a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the vacuum thin film production method, for example, 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.
As the casting method, the inorganic or organic charge generating material, and optionally binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclopentanone, anisole, xylene, methyl ethyl ketone It can be formed by dispersing with a ball mill, attritor, sand mill, bead mill or the like using a solvent such as acetone, ethyl acetate, butyl acetate, etc., and applying the solution after diluting the dispersion appropriately. Further, a leveling agent such as dimethyl silicone oil or methyl phenyl silicone oil can be added as necessary. Examples of the application include dip coating, spray coating, bead coating, ring coating, and the like.
The thickness of the charge generation layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.01 μm to 5 μm, and more preferably 0.05 μm to 2 μm.

(2) Charge transport layer The charge transport layer is a layer having a charge transport function, and generally contains at least a charge transport material and a binder resin.
As the charge transport material, the electron transport material, the hole transport material, and the polymer charge transport material described in the section describing the charge generation layer can be used. In particular, the use of a polymer charge transport material is particularly useful because it shows the effect of reducing the solubility of the lower layer during coating of the surface protective layer.

The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 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, ethyl cellulose, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl Examples thereof include thermoplastic or thermosetting resins such as carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin. These may be used individually by 1 type and may use 2 or more types together.
The content of the charge transport material is preferably 20 parts by mass to 300 parts by mass, and more preferably 40 parts by mass to 150 parts by mass with respect to 100 parts by mass 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 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. In addition, the same coating method as that for the charge generation layer can be used to form the lower layer portion of the charge transport layer.

If necessary, a plasticizer and a leveling agent can be further added to the charge transport layer.
As the plasticizer, for example, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used thereof is 30 parts by mass or less with respect to 100 parts by mass of the binder resin. preferable.
Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. The amount used is 100 parts by mass of the binder resin. 1 part by mass or less is preferable.

The thickness of the lower layer portion of the charge transport layer is preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm.
When the surface protective layer is the surface (surface portion) of the charge transport layer, as described in the method for preparing the surface protective layer, a coating containing the radical polymerizable composition on the lower layer portion of the charge transport layer. After applying the working fluid and drying it as necessary, the curing reaction is started by external energy such as heat or light to form a surface protective layer.
In the laminated photosensitive layer, the thickness of the surface protective layer is preferably 1 μm to 20 μm, and more preferably 2 μm to 10 μm. If the thickness is less than 1 μm, the durability may vary due to thickness unevenness, and if it exceeds 20 μm, the entire thickness of the charge transport layer may be increased and image reproducibility may be reduced due to charge diffusion.

<Single layer 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 is usefully used by providing the surface protective layer of the present invention on the photosensitive layer.
The photosensitive layer having a single layer structure is formed by dissolving or dispersing a charge generating material having a charge generating function, a charge transporting material having a charge transporting function, and a binder resin in an appropriate solvent, and applying and drying the solution. it can. 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 and the charge transport layer. As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer, the binder resin mentioned in the charge generation layer may be mixed and used. In addition, the polymer charge transport materials listed above can also be used, which is useful in that contamination of the photosensitive layer composition into the surface protective layer can be reduced.
The charge generation material contained in the single-layer photosensitive layer is preferably 1 to 30 parts by mass with respect to the total amount of the photosensitive layer, and the binder resin contained in the lower layer part of the photosensitive layer is 20 parts by mass in total. -80 mass parts is preferable, and 10 mass parts-70 mass parts is used favorably for the charge transport material.
There is no restriction | limiting in particular in the thickness of the said photosensitive layer, According to the objective, it can select suitably, 5 micrometers-30 micrometers are preferable, and 10 micrometers-25 micrometers are more preferable.
In the photosensitive layer having a single layer structure, the thickness of the surface protective layer is preferably 1 μm to 20 μm, and more preferably 2 μm to 10 μm.

-Intermediate layer-
In the electrophotographic photoreceptor of the present invention, it is possible to provide an intermediate layer between the surface protective layer and the charge transport layer, or between the surface protective layer and the single-layered photosensitive layer.
The intermediate layer prevents inhibition of the curing reaction and unevenness of the surface protective layer caused by mixing of the photosensitive layer composition in the surface protective layer containing the radical polymerizable composition. It is also possible to improve the adhesion between the photosensitive layer and the surface protective layer.
The intermediate layer generally contains a binder resin as a main component. Examples of the binder resin include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol.
There is no restriction | limiting in particular as a formation method of the said intermediate | middle layer, The coating method generally used can be employ | adopted.
There is no restriction | limiting in particular in the thickness of the said intermediate | middle layer, According to the objective, it can select suitably, 0.05 micrometers-2 micrometers are preferable.

-Undercoat layer-
In the electrophotographic photoreceptor of the present invention, an undercoat layer can be provided on the support.
The undercoat layer generally contains a resin as a main component, and further contains other components as necessary. The resin is a resin having a high solvent resistance with respect to a general organic solvent in consideration of applying a surface protective layer, a photosensitive layer, a charge generation layer, or an intermediate layer with a solvent on the undercoat layer. It is preferable.
The resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon. And curable resins that form a three-dimensional network structure, such as polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin.
To the undercoat layer, fine powder pigments of metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added for preventing moire and reducing residual potential.
The undercoat layer can be formed using a solvent and a coating method in the same manner as the photosensitive layer.
As the undercoat layer, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can also be used. In addition, the undercoat layer is provided with Al ₂ O ₃ by anodic oxidation, organic substances such as polyparaxylylene (parylene), and inorganic substances such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO _2. Can also be used satisfactorily. In addition, known ones can be used.
The thickness of the undercoat layer is not particularly limited and can be appropriately selected depending on the purpose, and is preferably 5 μm or less.

  In the present invention, in order to improve environmental resistance, a photosensitive layer, a surface protective layer, a charge generation layer, a charge transport layer, an undercoat layer having a single layer structure are used for the purpose of preventing a decrease in sensitivity and an increase in residual potential. An antioxidant can be added to each layer such as an intermediate layer.

Examples of the antioxidant include phenolic compounds, paraphenylenediamines, hydroquinones, organic sulfur compounds, and organic phosphorus compounds. These may be used individually by 1 type and may use 2 or more types together.
Examples of the phenol compound include 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-t-butylphenol), 2,2'-methylene-bis- (4-ethyl- 6-t-butylphenol), 4,4′-thiobis- (3
-Methyl-6-t-butylphenol), 4,4'-butylidenebis- (3-methyl-6-t-butylphenol), 1,1,3-tris- (2-methyl-4-hydroxy-5-t- Butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5 '-Di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] cricol ester, tocopherol And the like.
Examples of the paraphenylenediamines include 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.
Examples of the hydroquinones include 2,5-di-t-octyl hydroquinone, 2,6-didodecyl hydroquinone, 2-dodecyl hydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methyl. And hydroquinone and 2- (2-octadecenyl) -5-methylhydroquinone.
Examples of the organic sulfur compounds include dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like. It is done.
Examples of the organic phosphorus compounds include triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
In addition, these compounds are known as antioxidants, such as rubber | gum, a plastic, and fats and oils, and a commercial item can be obtained easily.
There is no restriction | limiting in particular in the addition amount of the said antioxidant, According to the objective, it can select suitably, 0.01 mass part-10 mass parts are preferable with respect to the total mass of the layer to add.

(Image forming device)
The image forming apparatus according to the present invention includes at least an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, a transfer unit, and a fixing unit. The other means, for example, a static elimination means, a recycling means, a control means, etc. are provided. The charging unit and the exposure unit may be collectively referred to as an electrostatic latent image forming unit.

-Electrostatic latent image forming means-
The electrostatic latent image forming unit is a unit that forms an electrostatic latent image on the electrophotographic photosensitive member.
As the electrophotographic photoreceptor, the electrophotographic photoreceptor of the present invention is used.
The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrophotographic photosensitive member and then performing imagewise exposure, and can be performed by the electrostatic latent image forming unit. it can.
The electrostatic latent image forming means includes at least a charger that uniformly charges the surface of the electrophotographic photosensitive member and an exposure device that exposes the surface of the electrophotographic photosensitive member imagewise.

The charging can be performed, for example, by applying a voltage to the surface of the electrophotographic photosensitive member using the charger.
The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roller, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons and corotrons.
The shape of the charging member may take any form such as a magnetic brush or a fur brush in addition to the roller, and can be selected according to the specifications and form of the electrophotographic apparatus. When using the magnetic brush, as the magnetic brush, for example, various ferrite particles such as Zn-Cu ferrite are used as a charging member, and a non-magnetic conductive sleeve for supporting it, and a magnet roll included therein Composed. Or, when using a brush, for example, as a material of the fur brush, a fur treated with carbon, copper sulfide, metal or metal oxide is used, and this is wound or attached to a metal or other conductive core. To make a charger.
The charger is not limited to the contact charger as described above. However, since an image forming apparatus in which ozone generated from the charger is reduced is obtained, a contact charger is used. preferable.
It is preferable that the charger is disposed in contact or non-contact with the electrophotographic photosensitive member and charges the surface of the electrophotographic photosensitive member by applying a direct current and an alternating voltage.
The charging device is a charging roller that is disposed in close proximity to the electrophotographic photosensitive member via a gap tape, and charges the surface of the electrophotographic photosensitive member by applying a direct current and an alternating voltage to the charging roller. Those are preferred.

The exposure can be performed, for example, by exposing the surface of the electrophotographic photosensitive member imagewise using the exposure device.
The exposure device is not particularly limited as long as the surface of the electrophotographic photosensitive member charged by the charger can be exposed like an image to be formed, and can be appropriately selected according to the purpose. However, various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system can be used.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

-Development means-
The developing means is means for developing the electrostatic latent image using toner or developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using a toner or a developer, and can be performed by the developing unit.
The developing unit is not particularly limited as long as it can be developed using, for example, the toner or the developer, and can be appropriately selected from known ones. For example, the toner or developer is accommodated. Preferred examples include those having at least a developing unit capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image.
The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a toner having a stirrer for charging the toner or the developer by frictional stirring and a rotatable magnet roller is preferable.
In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrophotographic photosensitive member, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted to the electrophotographic photosensitive member. Move to the surface of the body. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrophotographic photosensitive member.

  The developer accommodated in the developing device may be a one-component developer or a two-component developer, and may be prepared by any one of a pulverization method and a polymerization method. In recent years, in order to achieve high image quality, a toner having a small particle size and a nearly spherical shape has been used. However, since it becomes difficult to clean the toner, it is hydrophobic as an external additive having a primary average particle size of 100 nm to 200 nm. By using the active silica on the toner surface, the cleaning property is improved, and the effect of reducing the adhesion between the photoreceptor and the toner or between the intermediate transfer belt and the toner is reduced. Further, the adhesion force between the toners can be reduced, and the fluidity and charging characteristics can be improved. However, the external additive easily adheres to the surface of the electrophotographic photosensitive member, and silica accumulates on the adhered hydrophobic silica, or the toner resin adheres, thereby generating an abnormal image in which the adhered matter appears as an image. Therefore, an electrophotographic photoreceptor using a surface protective layer made of a cured product of at least the epoxy acrylate compound of the present invention, a radically polymerizable compound having three or more functional groups, and a radically polymerizable compound having a charge transporting structure is used. Thus, excellent releasability can be obtained, so that a good image having no abnormal image can be obtained.

For the toner used in the present invention, a kneading and pulverizing method in which a resin, a pigment, a charge control agent, and a release agent are melt-kneaded, cooled and then pulverized and classified can be used. Therefore, it is preferable to use those prepared using a polymerization toner method such as an emulsion polymerization method or a dissolution suspension method.
The external additive added to the toner surface is preferably hydrophobic silica having a primary average particle size of 100 nm to 200 nm. The primary average particle size is more preferably 120 nm to 180 nm. When the primary average particle diameter is less than 100 nm, toner cleaning properties may be deteriorated and streaky abnormal images may be generated. When the average particle diameter exceeds 200 nm, toner flow characteristics and charging characteristics are deteriorated, and soiling or the like may occur. May occur.
The primary average particle diameter of the hydrophobic silica can be determined by measuring the diameter of 50 particles from an observation image using an electrophotographic microscope such as SEM or TEM and deriving an average value.
The hydrophobicity of the hydrophobic silica is preferably 50% to 90%, more preferably 55% to 85%. When the degree of hydrophobicity is less than 50%, the toner charge leaks at high temperature and high humidity, and toner scattering and photoreceptor fogging are likely to occur. On the other hand, if the degree of hydrophobicity is greater than 90%, the toner tends to be excessively charged under low temperature and low humidity, which may cause image density defects. Further, the presence of excess hydrophobizing agent has an adverse effect such as poor toner fluidity.

The method for measuring the degree of hydrophobicity will be described below.
Add 50 ml of water to a 200 ml beaker and add 0.2 g of external additive fine particles. Then, while gently stirring with a magnetic stirrer, methanol was added from the burette whose tip was immersed in water at the time of dropping, and the floating external additive fine particles began to sink. Read and calculate from the following formula.
Hydrophobic degree (%) = (ml of methanol dropped / (50 + ml of methanol dropped)) × 100
By adhering the hydrophobic silica to the surface of the toner base particles by mixing and stirring. A toner can be produced.

The hydrophobic silica means a material that can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, fluorine Silane coupling agents having an alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, and the like.
Furthermore, in addition to the hydrophobic silica, other external additives can be used in combination. Examples of the inorganic fine particles include silica, alumina, titania, barium titanate, magnesium titanate, calcium titanate, and titanic acid. Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples thereof include silicon and silicon nitride.

  The content of the external additive in the toner is preferably 0.01% by mass to 5.0% by mass, and more preferably 0.01% by mass to 2.0% by mass.

-Transfer means-
The transfer means is a means for transferring the visible image to a recording medium. The intermediate recording medium is used to primarily transfer the visible image onto the intermediate recording medium, and then the visible image is transferred onto the recording medium. A primary transfer unit for forming a composite transfer image by transferring a visible image onto an intermediate recording medium using two or more colors, preferably a full color toner, as the toner, and a composite transfer image; An embodiment including a secondary transfer unit that transfers a transfer image onto a recording medium is more preferable.
The transfer can be performed, for example, by charging the electrophotographic photosensitive member with the transfer charger using the visible image, and can be performed by the transfer unit. The transfer unit includes a primary transfer unit that transfers a visible image onto an intermediate recording medium to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. Embodiments are preferred.
The intermediate recording medium is not particularly limited and may be appropriately selected from known recording media according to the purpose. For example, a transfer belt or the like is preferable.
The transfer unit (the primary transfer unit and the secondary transfer unit) includes at least a transfer unit that peels and charges the visible image formed on the electrophotographic photosensitive member toward the recording medium. preferable. There may be one transfer means or two or more transfer means.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and can be appropriately selected according to the purpose. PET for OHP A base or the like can also be used.

-Fixing means-
The fixing unit is a unit that fixes the visible image transferred to the recording medium, and may be performed each time the toner of each color is transferred to the recording medium, or a state in which the toner is stacked on the toner of each color. Can be done at the same time.

The fixing unit is not particularly limited and may be appropriately selected depending on the intended purpose, but a known heating and pressing unit is preferable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.
The heating in the heating and pressing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or in place of the fixing step and the fixing unit depending on the purpose.

The neutralizing unit is a unit that performs neutralization by applying a neutralizing bias to the electrophotographic photosensitive member.
The neutralizing means is not particularly limited and may be appropriately selected from known neutralizers as long as it can apply a neutralizing bias to the electrophotographic photosensitive member. For example, a neutralizing lamp is preferably used. Can be mentioned.

The cleaning means is means for removing the electrophotographic toner remaining on the electrophotographic photosensitive member.
The cleaning means is not particularly limited, and may be selected from known cleaners as long as the electrophotographic toner remaining on the electrophotographic photosensitive member can be removed. For example, a magnetic brush cleaner Suitable examples include electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

The recycling means is means for recycling the color toner for electrophotography removed by the cleaning means to the developing means.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control means is means for controlling the steps.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

The image forming apparatus according to the present invention uses the electrophotographic photosensitive member having the surface protective layer according to the present invention. For example, the toner image on the recording medium (transfer paper) after at least charging, image exposure, and development of the photosensitive member The image forming apparatus includes processes of transferring, fixing, and cleaning the surface of the photoreceptor.
In some cases, an image forming method or the like in which an electrostatic latent image is directly transferred to a transfer member and developed does not necessarily have the above-described process arranged on a photosensitive member.

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

Next, the developing unit 6 is used to visualize the electrostatic latent image formed on the photoreceptor 1. Development methods include a one-component development method using a dry toner, a two-component development method, and a wet development method using a wet toner. When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. 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 photoreceptor onto the recording medium 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 recording medium 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 photoconductor after transfer. Further, a pre-cleaning charger 13 may be used in order to perform cleaning more efficiently. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.
Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, the charge removal lamp 2 and the 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 apparatus using the electrophotographic photosensitive member of the present invention for such image forming means.
The image forming means may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge and made detachable.

(Process cartridge)
A process cartridge according to the present invention includes the electrophotographic photosensitive member according to the present invention and at least one means selected from a charging unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. Detachable.
FIG. 4 is a schematic view showing an example of the process cartridge of the present invention.
The process cartridge shown in FIG. 4 incorporates the electrophotographic photosensitive member 101 of the present invention, includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and further includes other units as necessary. Become. In FIG. 4, reference numeral 103 denotes exposure by exposure means, and 105 denotes a recording medium.

Next, the image forming process using the process cartridge shown in FIG. 4 will be described. The electrophotographic photosensitive member 101 has its surface formed by charging by the charging means 102 and exposure 103 by the exposure means (not shown) while rotating in the direction of the arrow. Then, an electrostatic latent image corresponding to the exposure image is formed.
The electrostatic latent image is developed by the developing unit 104, and the obtained visible image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the electrophotographic photosensitive member after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

  Since the image forming apparatus and the process cartridge of the present invention use an electrophotographic photosensitive member having a surface protective layer having high wear resistance, smooth surface properties, and almost no variation in electrical characteristics, an image due to wear is used. Deterioration can be suppressed, and high-definition and high-quality images can be formed over a long period of time.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Synthesis Example 1)
<Synthesis Example of Compound having Charge Transporting Structure>
The compound having the charge transporting structure is synthesized based on, for example, a method described in Japanese Patent No. 3164426.
(1) Synthesis of hydroxy group-substituted triarylamine compound (the following structural formula B) 113.85 g (0.3 mol) of a methoxy group-substituted triarylamine compound (the following structural formula A) and 138 g (0.92 mol) of sodium iodide To this, 240 ml of sulfolane was added and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and repeatedly washed with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (silica gel as the adsorption medium and toluene: ethyl acetate = 20: 1 as the developing solvent).
Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g (yield = 80.4%) of white crystals of the following structural formula B was obtained. The melting point is 64.0 ° C to 66.0 ° C. Elemental analysis values (unit:%) are shown in Table A.

(2) Triarylamino group-substituted acrylate compound (Exemplary Compound No. 7)
82.9 g (0.227 mol) of the hydroxy group-substituted triarylamine compound (Structural Formula B) obtained in (1) above was dissolved in 400 ml of tetrahydrofuran, and an aqueous sodium hydroxide solution (NaOH: 12.4 g, Water: 100 ml) was added dropwise. The solution was cooled to 5 ° C., and 25.2 g (0.272 mol) of acrylic acid chloride was added dropwise over 40 minutes. Then, it stirred at 5 degreeC for 3 hours, and reaction was complete | finished. The reaction solution was poured into water and extracted with toluene. This extract was repeatedly washed with an aqueous sodium bicarbonate solution and water. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene). N-Hexane was added to the obtained colorless oil to precipitate crystals. As described above, Exemplified Compound Nos. Represented by the following structural formulas 80.73 g (yield = 84.8%) of 7 white crystals were obtained. The melting point is 117.5-119.0 ° C. Table B shows elemental analysis values (unit:%).

Example 1
<Production of electrophotographic photoreceptor>
Undercoat layer coating solution, charge generation layer coating solution, and charge transport layer coating solution having the following composition are sequentially applied by dip coating on an aluminum cylinder having a wall thickness of 0.8 mm, a length of 346 mm, and an outer diameter of 40 mm. Application and drying were performed to form an undercoat layer having a thickness of 3.5 μm, a charge generation layer having a thickness of 0.2 μm, and a charge transport layer having a thickness of 23 μm.

-Undercoat layer coating solution-
・ Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.) ... 6 parts by mass・ 4 parts by mass ・ Titanium oxide: 40 parts by mass ・ Methyl ethyl ketone: 50 parts by mass

-Charge generation layer coating solution-
-Bisazo pigment represented by the following structural formula: 2.5 parts by mass
・ Polyvinyl butyral (XYHL, manufactured by UCC): 0.5 part by mass ・ Cyclohexanone: 200 part by mass ・ Methyl ethyl ketone: 80 part by mass

-Charge transport layer coating solution-
-Bisphenol Z-type polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) ... 10 parts by mass-Charge transport material represented by the following structural formula: 7 parts by mass
Tetrahydrofuran: 100 parts by mass Silicone oil tetrahydrofuran solution (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass

Next, the surface of the charge transport layer is spray-coated using a surface protective layer coating solution having the following composition, and light is applied using a metal halide lamp under conditions of irradiation intensity: 500 mW / cm ² and irradiation time: 20 seconds. Irradiation was performed, and further drying was performed at 130 ° C. for 30 minutes to form a surface protective layer having a thickness of 4.0 μm. Thus, the electrophotographic photosensitive member of Example 1 was produced.

-Surface protective layer coating solution-
-Epoxy acrylate compound represented by the following structural formula (epoxy ester 80MFA, manufactured by Kyoeisha Chemical Co., Ltd.) ... 20 parts by mass
Trifunctional or higher functional radically polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd., trifunctional) 75 parts by mass. Radical polymerizable compound having the charge transporting structure of Synthesis Example 1 (example) Compound No. 7) ... 95 parts by mass Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184, manufactured by Ciba Specialty Chemicals) ... 10 parts by mass Tetrahydrofuran ... 1 200 parts by mass

(Example 2)
<Production of electrophotographic photoreceptor>
Example 1 and Example 1 except that the epoxy acrylate compound in the surface protective layer coating solution was replaced with an epoxy acrylate compound (epoxy ester 70PA, manufactured by Kyoeisha Chemical Co., Ltd.) represented by the following structural formula. Similarly, an electrophotographic photosensitive member was produced.

(Example 3)
<Production of electrophotographic photoreceptor>
In Example 1, except that the epoxy acrylate compound in the surface protective layer coating solution was replaced with an epoxy acrylate compound represented by the following structural formula (epoxy ester 200PA, manufactured by Kyoeisha Chemical Co., Ltd.), the same as in Example 1. Thus, an electrophotographic photosensitive member was produced.

(Example 4)
<Production of electrophotographic photoreceptor>
In Example 1, it replaced with the epoxy acrylate compound (epoxy ester 40EM, Kyoeisha Chemical Co., Ltd.) represented by the following structural formula, and changed the epoxy acrylate compound in the surface protection layer coating liquid similarly to Example 1. Thus, an electrophotographic photosensitive member was produced.

(Example 5)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the trifunctional or higher functional radical polymerizable compound in the surface protective layer coating solution was changed to the following.
・ Trifunctional or higher radical polymerizable compound (dipentaerythritol hexaacrylate, KAYARAD DPHA, Nippon Kayaku Co., Ltd., 6 functional) ... 75 parts by mass

(Example 6)
<Production of electrophotographic photoreceptor>
In Example 1, the radical polymerizable compound (Exemplary Compound No. 7) having the charge transporting structure of Synthesis Example 1 in the surface protective layer coating solution was the same as Example 1 except that it was changed to the following. Thus, an electrophotographic photosensitive member was produced.
-Radical polymerizable compound having a charge transporting structure represented by the following structural formula (Exemplary Compound No. 38) ... 95 parts by mass

(Example 7)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface protective layer coating solution in Example 1 was replaced with the following surface protective layer coating solution.
-Surface protective layer coating solution-
-Epoxy acrylate compound represented by the following structural formula (epoxy ester 80MFA, manufactured by Kyoeisha Chemical Co., Ltd.) ... 20 parts by mass
Trifunctional or higher functional radically polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd., trifunctional) 75 parts by mass. Radical polymerizable compound having the charge transporting structure of Synthesis Example 1 (example) Compound No. 7) ... 95 parts by mass Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184, manufactured by Ciba Specialty Chemicals) ... 10 parts by mass Tetrahydrofuran ... 1 , 200 parts by mass Filler (Alumina filler, AA-03, manufactured by Sumitomo Chemical Co., Ltd., average primary particle size 0.3 μm) 20 parts by mass

(Example 8)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface protective layer coating solution in Example 1 was replaced with the following surface protective layer coating solution.
-Surface protective layer coating solution-
-Epoxy acrylate compound represented by the following structural formula (epoxy ester 80MFA, manufactured by Kyoeisha Chemical Co., Ltd.): 5 parts by mass
・ Trifunctional or higher radical polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd., trifunctional) 90 parts by mass ・ Radical polymerizable compound having the charge transporting structure of Synthesis Example 1 (Exemplary) Compound No. 7) ... 95 parts by mass Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184, manufactured by Ciba Specialty Chemicals) ... 10 parts by mass Tetrahydrofuran ... 1 200 parts by mass

Example 9
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the surface protective layer coating solution in Example 1 was replaced with the following surface protective layer coating solution.
-Surface protective layer coating solution-
-Epoxy acrylate compound represented by the following structural formula (epoxy ester 80MFA, manufactured by Kyoeisha Chemical Co., Ltd.): 45 parts by mass
Trifunctional or higher radical polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd., trifunctional) ... 45 parts by mass. Radical polymerizable compound having the charge transporting structure of Synthesis Example 1 (example) Compound No. 7) ... 95 parts by mass Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184, manufactured by Ciba Specialty Chemicals) ... 10 parts by mass Tetrahydrofuran ... 1 200 parts by mass

(Comparative Example 1)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the epoxy acrylate compound in the surface protective layer coating solution was replaced with the following radical polymerizable compound.

(Comparative Example 2)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the epoxy acrylate compound in the surface protective layer coating solution was replaced with the following radical polymerizable compound.

(Comparative Example 3)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the epoxy acrylate compound in the surface protective layer coating solution was replaced with the following radical polymerizable compound.

(Comparative Example 4)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the trifunctional or higher radical polymerizable compound in the surface protective layer coating solution was replaced with the following bifunctional radical polymerizable compound. Was made.
-Bifunctional radically polymerizable compound represented by the following structural formula (bifunctional acrylate: KAYARAD NPGDA, manufactured by Nippon Kayaku Co., Ltd.) 75 parts by mass

(Comparative Example 5)
<Production of electrophotographic photoreceptor>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having the charge transporting structure in the surface protective layer coating solution was changed to the following charge transporting material. did.
-Charge transport material represented by the following structural formula: 95 parts by mass

Next, the produced electrophotographic photoreceptors of Examples 1 to 9 and Comparative Examples 1 to 5 were mounted on a process cartridge, and hydrophobic silica (hydrophobic degree 65%) having a primary average particle diameter of 150 nm was added to the surface. In addition, using a spherical toner having an average particle size of 5.5 μm (manufactured by Ricoh Co., Ltd., prototype polymerization toner) and using an image forming apparatus (manufactured by Ricoh Co., Ltd., imagio MPC4500 modified machine), a total of 500,000 sheets continuously. The actual machine passing test was conducted, and the wear amount, the in-machine potential, and the image evaluation were performed as follows. The results are shown in Table 1.
In addition, the primary average particle diameter of hydrophobic silica measured the diameter of 50 particles from the image observed by 30,000 time using FE-SEM (S-4200, Hitachi, Ltd.), and calculated the average value. Measured by deriving.

<Measurement of wear>
Before and after passing 500,000 sheets, the film thickness of the electrophotographic photosensitive member was measured using an eddy current film thickness meter (Fisherscope MMS, manufactured by Fisher Instruments Co., Ltd.). The difference was defined as the amount of wear.

<Measurement of in-flight potential>
After passing 500,000 sheets, a surface potential meter (surface potential meter Model 344, manufactured by Trek) was set on the image forming apparatus (made by Ricoh Co., Ltd., imagio MPC4500 modified machine) used in the actual machine passing test. The surface potential when one A4 size image of the pattern and the entire black pattern was output was measured, and the dark portion potential and the bright portion potential were obtained.

<Image evaluation>
After passing 500,000 sheets using the image forming apparatus (made by Ricoh Co., Ltd., imagio MPC4500 modified machine) used in the actual machine paper passing test, A3 size of full white pattern, full black pattern, and full halftone pattern Two images were output, and the presence or absence of abnormal images was confirmed.

(Examples 10 to 12)
In Examples 10 to 12, evaluation was performed using the following toners and the electrophotographic photosensitive member of Example 1.
As Example 10, a spherical toner (manufactured by Ricoh Co., Ltd., a prototype polymerized toner) having an average particle size of 5.5 μm with hydrophobic silica having a primary average particle size of 100 nm (hydrophobic degree 65%) added to the surface thereof was used.
As Example 11, a spherical toner (manufactured by Ricoh Co., Ltd., prototype polymerization toner) having an average particle size of 5.5 μm, which was obtained by adding hydrophobic silica having a primary average particle size of 200 nm (hydrophobic degree 65%) to the surface thereof, was used.
As Example 12, a spherical toner (manufactured by Ricoh Co., Ltd., prototype polymerization toner) having an average particle size of 5.5 μm, which was obtained by adding untreated surface silica having a primary average particle size of 150 nm to the surface.
Here, the primary average particle diameter of the hydrophobic silica was determined by measuring the diameter of 50 particles from an image observed at 30,000 times using FE-SEM (S-4200, manufactured by Hitachi, Ltd.), and calculating the average value. Was measured by deriving.
A total of 500,000 sheets of the toners of Examples 10 to 12 were continuously used by using the image forming apparatus (manufactured by Ricoh Co., Ltd., imagio MPC4500 modified machine) in which the electrophotographic photosensitive member of Example 1 was mounted on a process cartridge. The actual machine paper passing test was conducted, and in the same manner as in Examples 1 to 9 and Comparative Examples 1 to 5, the wear amount, the in-machine potential, and the image evaluation were performed. The results are shown in Table 2.

  The electrophotographic photosensitive member of the present invention includes, for example, a laser printer, a direct digital plate making machine, a full color copying machine using a direct or indirect electrophotographic multicolor image developing system, a full color laser printer, a CRT printer, an LED printer, a liquid crystal printer, a laser. It can be widely used for plate making and full color plain paper fax.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Static elimination lamp 3 Charger charger 4 Eraser 5 Image exposure part 6 Development unit 7 Charger before transfer 8 Registration roller 9 Recording medium 10 Transfer charger 11 Separation charger 12 Separation claw 13 Charger before cleaning 14 Fur brush 15 Cleaning blade 101 Photosensitive drum DESCRIPTION OF SYMBOLS 102 Charging apparatus 103 Exposure 104 Developing apparatus 105 Recording medium 106 Transfer apparatus 107 Cleaning blade 201 Support body 202 Photosensitive layer 203 Surface protective layer 204 Charge generation layer 205 Charge transport layer

Japanese Patent Publication No.58-7988 Japanese Patent No. 4208367 Japanese Patent No. 4160512 JP-A-6-95413 Japanese Patent No. 3938209 Japanese Patent No. 4214655

Claims (8)

A support, and at least a photosensitive layer and a surface protective layer on the support;
The surface protective layer is an epoxy acrylate compound represented by at least one of the following general formulas (I) and (II), a trifunctional or higher functional radical polymerizable compound, and a radical polymerizable compound having a charge transporting structure; An electrophotographic photoreceptor comprising a cured product of:
However, in said general formula (I), R < ¹ > and R < ² > both represent either a hydrogen atom or a methyl group. n represents an integer of 1 to 3.
However, in said general formula (II), R < ¹ > represents either a hydrogen atom or a methyl group. The electrophotographic photoreceptor according to claim 1, wherein the epoxy acrylate compound represented by the general formula (I) is an epoxy acrylate compound represented by the following structural formula.
The electrophotographic photoreceptor according to claim 1, wherein the epoxy acrylate compound represented by the general formula (II) is an epoxy acrylate compound represented by the following structural formula.
  The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the content of the epoxy acrylate compound is 5 parts by mass to 100 parts by mass with respect to 100 parts by mass of the tri- or higher functional radical polymerizable compound.   The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains a filler.   An electrophotographic photosensitive member according to any one of claims 1 to 5, and at least one means selected from a charging means, a developing means, a transfer means, a cleaning means, and a charge eliminating means, A process cartridge which is detachable. An electrophotographic photosensitive member; a charging unit that charges the surface of the electrophotographic photosensitive member; an exposure unit that exposes the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image; and The image forming apparatus includes at least a developing unit that forms a visible image by developing the image, a transfer unit that transfers the visible image to a recording medium, and a fixing unit that fixes the transferred image transferred to the recording medium. A device,
An image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.   The image forming apparatus according to claim 7, wherein the toner includes hydrophobic silica having a primary average particle diameter of 100 nm to 200 nm on a surface thereof.