JP2012128324A - Electrophotographic photoreceptor, and image forming apparatus and process cartridge using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor achieving superior durability and stable image formation with high quality for a long period of time by including a surface protective layer having high wear resistance and excellent toner releasability and capable of suppressing generation of an abnormal image or the like due to cleaning failure for a long period of time.SOLUTION: The electrophotographic photoreceptor comprises a support body and at least a photosensitive layer and a surface protective layer on the support body. The surface protective layer contains a cured product of urethane acrylate containing at least a perfluoropolyether part, a radical polymerizable monomer having three or more functional groups, and a radical polymerizable compound having a charge transporting structure.

Description

  The present invention uses a surface protective layer that has high abrasion resistance and excellent toner releasability, and can suppress the occurrence of abnormal images due to poor cleaning over a long period of time. The present invention relates to an electrophotographic photoreceptor capable of realizing stable and high-quality image formation over a long period of time, and an image forming apparatus and a process cartridge using the electrophotographic photoreceptor.

  Conventionally, organic photoreceptors (OPCs) have been widely used for copying machines, facsimile machines, laser printers, and their combined machines in place of inorganic photoreceptors because of various advantages. This is because, 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 higher image quality, the cleaning blade is required to increase its rubber hardness and contact pressure for the purpose of improving the cleaning property as the particle size of the toner particles is reduced. This also promotes the wear of the photoreceptor. It is a factor. Such 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. Further, scratches where wear is locally generated cause streak-like stain images due to poor cleaning.

  Therefore, 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 improving the cleaning property. In particular, if the toner component adheres to the surface due to a decrease in the amount of wear, the surface cannot be scraped, so it is difficult to remove the adhering matter, leading to an abnormal image. There is a need for an organophotoreceptor having.

  For example, (1) an antioxidant having a cured chain polymerizable functional group and a silicon atom in the surface protective layer, an anti-degradation agent, light shielding Containing a compound obtained by polymerizing an agent or a lubricant (Patent Document 1), (2) A copolymer containing polyorganosiloxane as a constituent component is dispersed in the surface layer, and the surface layer has at least a charge transporting structure Using a cross-linked resin layer obtained by curing a tri- or higher functional radical-polymerizable monomer having no charge and a monofunctional radical-polymerizable compound having a charge transporting structure (Patent Document 2), (3) on the outermost surface of the photoreceptor One containing 10% by weight or more of fluororesin fine particles so that the contact angle with pure water is 100 ° or more (Patent Document 3), (4) The peripheral surface of the electrophotographic photosensitive member has a plurality of dimple-shaped recesses. so A method for obtaining high cleaning properties (Patent Document 4), (5) The photosensitive layer contains a polyester resin having a specific structural unit, and a wax having 20 to 150 carbon atoms formed by ester bonding of a carboxylic acid and an alcohol. (Patent Document 5), (6) The outermost surface layer contains any one of a specific polyarylate resin, polytrifluoroethylene and perfluoropolyether or a mixture thereof (Patent Document 6), (7) The surface layer contains a polymer having a specific repeating structural unit composed of an acrylate monomer having at least one of a fluoroalkyl group and a fluoroalkylene group, a methacrylate monomer, etc. (Patent Document 7), and (8) perfluoropolyester in the surface layer. Includes a crosslinked polysiloxane composition containing an ether moiety (Patent Document 8), (9) Specific surface protective layer The surface treatment silica particles and a layer mainly formed by applying and curing a composition mainly containing a photopolymerization initiator, and further, a chemical adsorption layer through a siloxane bond is provided on the surface of the surface protective layer (patent) Reference 9). However, in any of these, the mechanical durability and high releasability required for the organic photoreceptor, and the characteristics for maintaining the stability of the image over a long period of time have been sufficiently satisfied. Not in.

  In view of the above, even in the prior art documents, it cannot be said that the organic photoreceptor having a satisfactory surface property still has a satisfactory overall characteristic.

  An object of the present invention is to solve various problems in the prior art and achieve the following objects. That is, the present invention has excellent durability by using a surface protective layer that has high wear resistance and excellent toner releasability and can suppress the occurrence of abnormal images due to poor cleaning over a long period of time. Another object of the present invention is to provide an electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time, and an image forming apparatus and a process cartridge using the electrophotographic photosensitive member.

  As a result of intensive studies by the present inventors in order to solve the above problem, in the electrophotographic photosensitive member having at least a photosensitive layer and a surface protective layer on a support, the surface protective layer has at least a perfluoropolyether moiety. It has been found that the above problem can be effectively achieved by containing a cured product of a urethane acrylate containing, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure.

The present invention is based on the above findings by the present inventors, and means for solving the above 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
Urethane acrylate containing at least a perfluoropolyether moiety;
A tri- or higher functional radical polymerizable monomer;
An electrophotographic photoreceptor comprising a cured product with a radical polymerizable compound having a charge transporting structure.
<2> The electrophotographic photosensitive member according to <1>, wherein the urethane acrylate containing a perfluoropolyether moiety is a bifunctional acrylate having an isocyanurate skeleton.
<3> The cured product is a cured product of 0.1 to 5 parts by mass of urethane acrylate containing a perfluoropolyether portion with respect to 100 parts by mass of a tri- or higher functional radical polymerizable monomer <1 > Or <2>.
<4> The electrophotographic photosensitive member according to any one of <1> to <3>, wherein the surface protective layer contains a filler.
<5> The electrophotographic photosensitive member according to any one of <1> to <4>, and at least one unit selected from a charging unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit, A process cartridge which is detachable from an image forming apparatus main body.
<6> An electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, exposure means for exposing the charged electrophotographic photosensitive member surface to form an electrostatic latent image, and the electrostatic latent image At least development means for developing a visible image by using toner, transfer means for transferring the visible image to a recording medium, and fixing means for fixing the transfer image transferred to the recording medium An image forming apparatus,
The image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of <1> to <4>.

The electrophotographic photosensitive member of the present invention contains a cured product of urethane acrylate having a perfluoropolyether moiety in the surface protective layer, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure. By doing so, high wear resistance and high mold releasability can be obtained.
Examples of urethane acrylates containing perfluoropolyether moieties include those obtained by adding a perfluoropolyether moiety and an acrylic component to a triisocyanate having three NCO groups in the compound. Since the perfluoropolyether portion having moldability can be uniformly distributed in the surface protective layer, it has been found that high releasability can be obtained over a long period of time. In particular, it has been found that high release properties can be obtained over a long period of time particularly by including urethane acrylate containing one perfluoropolyether moiety and two acrylic components and having an isocyanurate skeleton in the surface protective layer. Although the reason is not clear, it is presumed that the following effects are obtained. That is, in general, the perfluoropolyether moiety can impart high releasability due to its structure, but it is difficult to uniformly distribute in the surface layer due to low compatibility. , High releasability cannot be maintained over a long period of time, and when it is unevenly distributed, the portion where the perfluoropolyether part is densely distributed reduces the mechanical strength of the film and promotes scratches and wear. Although there is a problem, the perfluoropolyether moiety can be evenly distributed by using urethane acrylate with a perfluoropolyether moiety and an acrylic component added to the triisocyanate in which three NCO groups are linked in the compound. Since the acrylic component is uniformly fixed in the surface protective layer by the curing reaction, it has excellent releasability and lowers the mechanical strength of the film. It has become possible to obtain gastric surface protective layer.

  In addition, by using a radically polymerizable monomer having three or more functional groups, a three-dimensional network structure is actively developed by a curing reaction, and a high protective property is achieved by obtaining a surface protective layer having a high crosslinking density. Furthermore, since the cross-linking reaction with the acrylic component added to the triisocyanate is actively performed, it becomes possible to uniformly distribute the perfluoropolyether portion in the network structure. It became possible to balance sex.

  In addition, the formation of the surface protective layer in the present invention includes a composition containing a radical polymerizable compound having a charge transporting structure in addition to a urethane acrylate containing a perfluoropolyether moiety and a trifunctional or higher functional radical polymerizable monomer. These are cured at the same time in a short time to form a high-hardness cross-linked bond, and an improvement in durability is achieved. 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, sensitivity decreases due to charge trapping, and residual potential increases.

  Therefore, according to the present invention, the surface protective layer is obtained by polymerizing a urethane acrylate having a perfluoropolyether moiety in the surface protective layer, a radical polymerizable monomer having three or more functional groups, and a radical polymerizable compound having a charge transporting structure. By forming the film, it is possible to realize an electrophotographic photosensitive member that can improve wear resistance, obtain high releasability over a long period of time, and maintain excellent image quality.

  According to the present invention, a surface protective layer that can solve conventional problems, has high wear resistance, is excellent in toner releasability, and can suppress the occurrence of abnormal images due to poor cleaning over a long period of time. By using this, it is possible to provide an electrophotographic photosensitive member capable of realizing stable and high-quality image formation over a long period of time with excellent durability, and an image forming apparatus and a process cartridge using the electrophotographic photosensitive member. .

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 urethane acrylate containing at least a perfluoropolyether part, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure.

-Urethane acrylate containing perfluoropolyether moiety-
The urethane acrylate containing a perfluoropolyether moiety used in the present invention can be prepared by reacting an NCO group present in an isocyanate and adding a perfluoropolyether moiety or an acrylic component. Among them, a compound obtained by adding a perfluoropolyether moiety and an acrylic component to a triisocyanate having three NCO groups in the compound is preferable, and thereby a perfluoropolyether moiety having high releasability in the cross-linked structure is formed on the surface. Since it can be uniformly distributed in the protective layer, high releasability can be obtained over a long period of time. In particular, by adding one perfluoropolyether moiety and two acrylic components to triisocyanate, it becomes possible to form a three-dimensional network structure by a crosslinking reaction with a trifunctional or higher-functional radical polymerizable monomer. In addition to the high releasability of the perfluoropolyether moiety, it is possible to obtain excellent wear resistance.

Examples of the triisocyanate used in the present invention include the following structures. Particularly, a structure having an isocyanurate skeleton has high compatibility and mechanical strength, and the perfluoropolyether portion can be uniformly distributed. Thus, an excellent surface protective layer can be formed. In addition, even if the perfluoropolyether part added to triisocyanate is added to any part of triisocyanate, a release effect can be obtained satisfactorily.

The perfluoropolyether moiety to be added to the isocyanate is reacted with a compound having one hydroxyl group at the molecular end having a perfluoropolyether group or a hydroxyl group at both ends of a molecule having a perfluoropolyether moiety. However, in order for the perfluoropolyether moiety to be uniformly distributed in the surface protective layer, a molecule having a hydroxyl group only at one end of a molecule having a perfluoropolyether portion has a degree of freedom. Highly desirable. Perfluoropolyether moieties can be linear, branched, cyclic, or combinations thereof, and can be saturated or unsaturated.
The perfluoropolyether has at least two chain-connected oxygen heteroatoms, and includes — (C _p F _2p ) —, — (C _p F _2p O) —, — (CF (Z)) —, — (CF (Z) O) - , - (CF (Z) C p F 2p O) -, - (C p F 2p CF (Z) O) -, or is selected from the group of a combination thereof, the repeating unit Although what it has is mentioned, it is not limited to these.
In these repeating units, p is not limited, but an integer of 1 to 10 is particularly desirable.
The Z group is a perfluoroalkyl group, a perfluoroether group, a perfluoropolyether, or a perfluoroalkoxy group, all of which can be linear, branched, or cyclic.
In these perfluoropolyether structures, various repeating units can be randomly dispersed along the chain.

The acrylic moiety to be added to the isocyanate is a (meth) acrylic acid ester having a hydroxyl group at the molecular end or side chain.
As an example of a monomer. Hydroxyethyl (meth) _{acrylate, HO (CH 2 CH 2 O} ) i-COC (R) C = CH 2 (R: H, CH 3, i = 2~10), CH 3 CH (OH) CH 2 OCOC ( R) C═CH ₂ (R: H, CH ₃ ; 2-hydroxypropyl (meth) acrylate), CH ₃ CH ₂ CH (OH) CH ₂ OCOC (R) C═CH ₂ (R: H, CH ₃ ; 2-hydroxybutyl (meth) _{acrylate), C 6 H 5 OCH 2} CH (OH) CH 2 OCOC (R) C = CH 2 (R: H, CH 3; 2- hydroxy-3-phenoxypropyl (meth) acrylate ), Allyl alcohol, HO (CH ₂ ) kCH═CH ₂ (k = 2 to 20), (CH ₃ ) ₃ SiCH (OH) CH═CH _{2 and the} like, but are not limited thereto.

In the present invention, it is possible to form a surface protective layer by adding an acrylic ester to at least one isocyanate among triisocyanates, but by adding them to two isocyanates, a stronger 3 This is desirable because a cross-linked structure having a dimensional network structure can be formed.
In the case of adding an acrylate ester to two isocyanates, in the same reactor, if the reaction is carried out with hydroxyl group of acrylic moiety / hydroxyl group of perfluoropolyether / isocyanate group of triisocyanate = 2/1/3 (equivalent), A bifunctional urethane acrylate containing a fluoropolyether moiety is obtained.

  As the urethane acrylate containing the perfluoropolyether moiety of the present invention, a suitably synthesized urethane acrylate may be used, or a commercially available product may be used.

  The content of the urethane acrylate containing a perfluoropolyether moiety is 0.1 to 5 parts by mass with respect to 100 parts by mass of a tri- or higher functional radical polymerizable monomer from the viewpoint of the balance between wear resistance and high releasability. Is preferred. When the content is less than 0.1 parts by mass, the releasability is lowered. When the content is more than 5 parts by mass, the wear resistance is reduced and the life is shortened.

-Radical polymerizable monomer with 3 or more functions-
The trifunctional or higher functional radical polymerizable monomer used in the present invention is, for example, an electron having a hole transporting structure such as triarylamine, hydrazone, pyrazoline, carbazole, etc. It refers to a monomer that does not have an electron transport structure such as an attractive aromatic ring and has three or more radically 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.
CH ₂ = CH-X ₁ -
However, in formula, X < ₁ > is arylene groups, such as the phenylene group which may have a substituent, a naphthylene group, the alkenylene group which may have a substituent, -CO- group, -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 the 1,1-substituted ethylene functional group include functional groups represented by the following formulas.
CH ₂ = CY-X ₂ -
(In the 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 (R ₇₉ is a hydrogen atom, an alkyl such as an optionally substituted methyl group or ethyl group) Group, an aralkyl group such as benzyl and phenethyl group which may have a substituent, an aryl group such as a phenyl group and a naphthyl group which may have a substituent, or -CONR ₈₀ R ₈₁ (R ₈₀ and R ₈₁ is a hydrogen atom, an alkyl group such as an optionally substituted methyl group, an ethyl group, an aralkyl group such as an optionally substituted benzyl group, naphthylmethyl group, or phenethyl group, or Place A phenyl group which may have a group, an aryl group such as phenyl or naphthyl, with each other the same or may be different.) Furthermore, X ₂ is identical substituents and a single bond and the X _1, 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 alkyl groups such as halogen atom, nitro group, cyano group, methyl group, and ethyl group, methoxy group, and ethoxy group. And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

  Among these radically polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. For example, a compound having three or more acryloyloxy groups may be a compound having three or more hydroxyl groups in the molecule and an acrylic group. It can be obtained by using an acid (salt), an acrylic acid halide, or an acrylic ester to cause an ester reaction or a transesterification reaction. 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. When the content is less than 30 parts by mass, the wear resistance decreases, and when it exceeds 70 parts by mass, the charge transport property decreases.

-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 charge transporting compound having a radical polymerizable functional group 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 to form a crosslink. In the polymer, it exists in the main chain of the polymer and in the cross-linked chain between the main chain and the main chain (this cross-linked chain includes an intermolecular cross-linked chain between one polymer and another polymer). And a part of the main chain folded in one polymer and an intramolecular cross-linked chain in which the other part derived from the polymerized monomer is cross-linked in the main chain at a position away from it) May be present in the main chain or in the cross-linked chain. Further, the radical polymerizable monomer 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. 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.

<Synthesis Example of Compound having Charge Transporting Structure>
The compound having the charge transporting structure in the present invention 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 64.0-66.0 ° C. Table 1 shows elemental analysis values (unit:%).

(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. Thus, 80.73 g (yield = 84.8%) of white crystals of (Exemplary Compound No. 7) was obtained. The melting point is 117.5-119.0 ° C. Table 2 shows elemental analysis values (unit:%).

-Polymerization initiator-
The surface protective layer contains a cured product of a urethane acrylate containing at least a perfluoropolyether moiety, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure, In order to advance the curing reaction efficiently, 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.
Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5- Peroxide initiators such as di (peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydrobelloxide, cumene hydroperoxide, lauroyl peroxide; azobisisobutylnitrile, azobiscyclohexane And azo initiators such as carbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, Acetophenone-based or ketal-based photopolymerization initiators such as 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one and 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl Benzoin ether photopolymerization initiators such as ether and benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, 1 Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene; thioxanthone photopolymerization such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Initiators; and the like.

  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 a urethane acrylate containing at least a perfluoropolyether moiety, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure, In addition to these components, 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, the ratio of the surface protective layer to the total solid content is preferably 30% by mass or less, and more preferably 20% by mass or less.

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 conventionally used surface treating agents can be used, the surface treating agent which can maintain the insulation of a filler is preferable.

  About the usage-amount of the said surface treating agent, although it changes with average primary particle diameters of the filler to be used, 3 mass parts-30 mass parts are preferable with respect to 100 mass parts of fillers, and 5 mass parts-20 mass parts are more preferable. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if the surface treatment amount is too much, the residual potential may be significantly increased.

The surface protective layer coating solution may contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement) as 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% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the surface protective layer coating solution.

  The surface protective layer coating solution may contain a binder resin as long as the smoothness, electrical characteristics, and durability of the surface of the photoreceptor are not impaired. However, when a polymer material such as a binder resin is included in the surface protective layer coating liquid, the high molecular weight produced by the curing reaction of the radical polymerizable composition (radical polymerizable monomer and radical polymerizable compound having a charge transporting structure). Phase separation occurs due to poor compatibility with molecules, and the surface protective layer surface becomes uneven. Therefore, it is preferable not to use a binder resin.

  The surface protective layer is coated with a surface protective layer coating solution containing a urethane acrylate containing at least a perfluoropolyether moiety, a tri- or higher functional radical polymerizable monomer, and a radical polymerizable compound having a charge transporting structure. And can be formed by 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.

In the present invention, 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 strain is generated 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 energy of the light, 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, but it is visible according to the absorption wavelength of the radical polymerizable substance or the photopolymerization initiator. A light source can also be selected.
The amount of irradiation light is preferably 50 mW / cm ² or more and 1,000 mW / cm ² or less. If the irradiation light quantity 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 non-uniform 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.

  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.

<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. On the surface of 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 provided with the surface protective layer 203 is shown.
FIG. 2 shows a structure in which a surface protective layer 203 is provided on the surface of a stacked 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. It 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.
Examples of the inorganic material include crystalline selenium, amorphous-selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous-silicon. In amorphous-silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms or phosphorus atoms 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 JP-A 06-236050, JP-A 06-236051, JP-A 06-295077, JP-A 07-056374, JP-A 08-176293, JP 08-208820, JP 08-21640 A, JP 08-253568 A, JP 08-269183 A, JP 09-062019 A, JP 09-038883 A, JP 09-71642 A, JP JP 09-87376, JP 09-104746, JP 09-110974, JP 09-110976, JP 09-157378, JP 09-221544, JP 09-09. No. 227669, JP 09-235367 A, JP 09-241369 JP-A 09-268226, JP-A 09-272735, JP-A 09-302084, JP-A 09-302085, JP-A 09-328539, and the like. Materials.

  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.
The low molecular charge transport material includes a hole transport material and an electron transport material.
Examples of the electron transporting material include chloroanil, bromoanil, 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.

Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives. , Triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, and the like, and other known materials such as bisstilbene derivatives and enamine derivatives.
These may be used individually by 1 type and may use 2 or more types together.

As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be mentioned.
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. Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The application can be performed by dip coating, spray coating, bead coating, ring coating, or the like.
The thickness of the charge generation layer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 0.01 μm to 5 μm, 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 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. The charge transport layer can be formed by the same coating method as that for the charge generation layer.

If necessary, a plasticizer and a leveling agent can be added.
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 charge transport layer is preferably 5 μm to 40 μm, more preferably 10 μm to 30 μm.

<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.
A photosensitive layer having a single-layer structure can be 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, applying the solution, and drying. . Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the charge generation material dispersion method, the charge generation material, the charge transport material, the plasticizer, and the leveling agent, the same charge generation layer and charge transport layer as those already described can be used. 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.
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.
The charge generation material contained in the photosensitive layer having a single layer structure is preferably 1% by mass to 30% by mass with respect to the total amount of the photosensitive layer, and the binder resin contained in the photosensitive layer is 20% by mass to 80% by mass. %, And the charge transport material is preferably used in an amount of 10% to 70% by weight.

-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 preferably a resin having high solvent resistance with respect to a general organic solvent in consideration of applying a photosensitive layer or a charge generation layer on the undercoat layer with a solvent.
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 formed by anodizing Al ₂ O ₃ , organic materials such as polyparaxylylene (parylene), and inorganic materials such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, and CeO _2. Can also be used satisfactorily. In addition, known ones can be used.
There is no restriction | limiting in particular in the thickness of the said undercoat layer, According to the objective, it can select suitably, 5 micrometers or less are preferable.

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-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3 -Tris- (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy Ben ) 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, tocopherols, 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%-10 mass% are preferable with respect to the total mass of the layer to add.

(Image forming device)
The image forming apparatus of 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, and a cleaning unit, and further appropriately selected as necessary. 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. In the case of using a magnetic brush, the magnetic brush is composed of, for example, various ferrite particles such as Zn-Cu ferrite as a charging member, and a non-magnetic conductive sleeve for supporting the same, and a magnet roll included therein. . 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 arranged in contact or non-contact with the electrophotographic photosensitive member and charges the surface of the electrophotographic photosensitive member by applying DC and AC voltages in a superimposed manner.
Further, the charger 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 are exemplified.
In the present invention, an optical backside system that performs imagewise exposure from the backside of the electrophotographic photosensitive member may be employed.

The developing means is means for developing the electrostatic latent image with the toner or developer to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the toner or developer, and can be performed by the developing unit.
The developing means 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 unit, for example, the toner and the carrier are mixed and stirred, 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 contained in the developing device may be a one-component developer. A two-component developer may be used, and a developer prepared by any one of a pulverization method and a polymerization method may be used.
As the external additive added to the toner surface, inorganic fine particles are preferably used. As inorganic fine particles, for example, silica, alumina, titania, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth, oxidation Examples thereof include chromium, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

The transfer means is a means for transferring the visible image to a recording medium, but directly transferring to the recording medium, or using an intermediate recording medium, and first transferring the visible image onto the intermediate recording medium, A mode in which the visible image is secondarily transferred onto the recording medium is exemplified. When two or more colors, preferably full color toners are used as the toner, a primary transfer means for forming a composite transfer image by transferring a visible image onto an intermediate recording medium, and transferring the composite transfer image onto the recording medium A mode including a secondary transfer unit is more preferable.
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.

The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the toner of each color is transferred to the recording medium, or for the toner of each color. You may perform this simultaneously in the state which laminated | stacked this.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. 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 neutralization step is a step of performing neutralization by applying a neutralization bias to the electrophotographic photosensitive member, and can be suitably performed by a neutralization unit.
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 step is a step of removing the electrophotographic toner remaining on the electrophotographic photosensitive member, and can be suitably performed by a cleaning unit.
The cleaning means is not particularly limited as long as it can remove the electrophotographic toner remaining on the electrophotographic photosensitive member, and can be appropriately selected from known cleaners. 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 step is a step of recycling the electrophotographic color toner removed in the cleaning step to the developing unit, and can be suitably performed by the recycling unit.
There is no restriction | limiting in particular as said recycling means, A well-known conveyance means etc. are mentioned.

The control step is a step of controlling each of the steps, and can be suitably performed by a control unit.
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 sequencers and computers.

The image forming apparatus of 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) is obtained 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 11 is used as means for charging the photoconductor 10 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 12 is used to form an electrostatic latent image on the uniformly charged photoreceptor 10. As the light source, all luminescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

Next, the developing unit 13 is used to visualize the electrostatic latent image formed on the photoconductor 10. 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 16 is used to transfer the toner image visualized on the photoreceptor onto the recording medium 15. In addition, a pre-transfer charger 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.
A separation charger or a separation claw is used as means for separating the recording medium 15 from the photoreceptor 10. 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, the charging means can be used.

Next, a fur brush or a cleaning blade 17 is used to clean the toner remaining on the photoconductor after transfer. In addition, a pre-cleaning charger may be used for more efficient cleaning. Other cleaning means include a web method, a magnet brush method, and the like, but each may be used alone or in combination.
Next, a neutralizing unit is used for the purpose of removing the latent image on the photoreceptor as required. As the charge removal means, a charge removal lamp 18 and 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 such an image forming unit.
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 106, 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 is charged by the charging unit 102 while being rotated in the clockwise direction, and exposed by the exposure unit (not shown) 103. An electrostatic latent image corresponding to the exposure image is formed on the surface.
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 106 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 and excellent toner releasability, abnormal images due to poor cleaning can be suppressed over a long period of time. High-definition and high-quality images can be formed.

[Synthesis example]
Hereinafter, although the synthesis example of the urethane acrylate containing the perfluoro polyether part used for this invention is demonstrated, this invention is not limited to these synthesis examples at all.
(Synthesis Example 1)
In a flask, 57 g of SUMIDUR N3300 (hexamethylene diisocyanate cyclic trimer, manufactured by Sumitomo Bayer Urethane Co., Ltd.) having the following structure was dissolved in 151 g of HCFC225, and 0.4 g of dibutyltin dilaurate (primary reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added. The mixture was heated to 40 to 45 ° C., and 24.4 g of hydroxyethyl acrylate was added dropwise over 10 minutes, followed by stirring for 3 hours. Subsequently, perfluoropolyether F (CF ₂ CF ₂ CF ₂ O) nCF ₂ CF ₂ CH ₂ OH (having a hydroxyl group at one end) over 4.5 hours with stirring at room temperature in air (manufactured by Daikin Industries, Ltd.) (Demnum SA: molecular weight 2000) A solution of 226 g of 226 g of HCFC225 in 153 g of HCFC225 was added dropwise and stirred at room temperature for 6 hours to obtain a 50 wt% HCFC225 solution of a bifunctional urethane acrylate having a perfluoropolyether moiety and an isocyanurate skeleton. Obtained.

(Synthesis Example 2)
SUMIDUR N3300 (hexamethylene diisocyanate cyclic trimer, manufactured by Sumitomo Bayer Urethane Co., Ltd.) 57 g, except that 54 g of DURANATE 24A-100 (manufactured by Asahi Kasei Chemicals Co., Ltd.) having the following structure was used. Thus, a 50 wt% HCFC225 solution of a bifunctional urethane acrylate having a perfluoropolyether moiety and not having an isocyanurate skeleton was obtained.

(Synthesis Example 3)
In Synthesis Example 1, 24.4 g of hydroxyethyl acrylate was changed to 12.2 g, and perfluoropolyether F (CF ₂ CF ₂ CF ₂ O) nCF ₂ CF ₂ CH ₂ OH having a hydroxyl group at one end (Daikin Industries) Demnum SA: molecular weight 2000) 226 g (HCFC225 153 g dissolved solution) was changed to 452 g (HCFC225 370 g dissolved solution), except that it was changed to 452 g (HCFC225 370 g dissolved solution) and had a perfluoropolyether moiety and an isocyanurate skeleton. A 50 wt% HCFC225 solution of monofunctional urethane acrylate was obtained.

(Comparative Synthesis Example 1)
In a flask, 57 g of SUMIDUR N3300 (hexamethylene diisocyanate cyclic trimer, manufactured by Sumitomo Bayer Urethane Co., Ltd.) having the above structure was dissolved in 94 g of HCFC225, and 0.4 g of dibutyltin dilaurate (primary reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added. It is heated to 40 to 45 ° C., 36.6 g of hydroxyethyl acrylate is dropped in 10 minutes and stirred for 3 hours, so that 50 wt% of the trifunctional urethane acrylate having no isocyanurate skeleton and no perfluoropolyether moiety. An HCFC225 solution was obtained.

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

Example 1
<Production of electrophotographic photoreceptor>
An undercoating layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating, dried, and coated with 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 were formed.
-Undercoat layer coating solution-
・ Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
... 6 parts by mass Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
... 4 parts by mass-Titanium oxide ... 40 parts by mass-Methyl ethyl ketone ... 50 parts by mass

・ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ社製） ・・・０．５質量部
・シクロヘキサノン ・・・２００質量部
・メチルエチルケトン ・・・８０質量部 -Charge generation layer coating solution-
-Bisazo pigment represented by the following structural formula: 2.5 parts by mass

・ Polyvinyl butyral (XYHL, manufactured by UCC Co., Ltd.) 0.5 mass part Cyclohexanone 200 mass parts Methyl ethyl ketone 80 mass parts

・テトラヒドロフラン ・・・１００質量部
・１質量部のシリコーンオイルのテトラヒドロフラン溶液
（ＫＦ５０−１００ＣＳ、信越化学工業株式会社製） ・・・１質量部 -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 Tetrahydrofuran solution of 1 part by mass of silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass

Next, spray coating is performed on the charge transport layer using a surface protective layer coating solution having the following composition, and light irradiation is performed under the conditions of a metal halide lamp, irradiation intensity: 500 mW / cm ² , and irradiation time: 20 seconds. And dried 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-
-Urethane acrylate of Synthesis Example 1 (50 wt% solution) ... 3 parts by mass-Trifunctional or higher-functional radical polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
... 75 parts by mass-Exemplified Compound No. Radical polymerizable compound having a charge transporting structure represented by 7
... 75 parts by mass-Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184,
Ciba Specialty Chemicals) 7.5 mass parts Tetrahydrofuran 1,200 mass parts

(Example 2)
<Production of electrophotographic photoreceptor>
In the surface protective layer coating solution of Example 1, the urethane acrylate of Synthesis Example 1 is 7.5 mass of bifunctional urethane acrylate having a perfluoropolyether moiety (20 wt% solution) (OPTOOL DAC, manufactured by Daikin Industries, Ltd.). An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the part was replaced with the part.

(Example 3)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the urethane acrylate of Synthesis Example 1 was replaced with the urethane acrylate of Synthesis Example 2 in the surface protective layer coating solution of Example 1.

Example 4
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the urethane acrylate of Synthesis Example 1 was replaced with the urethane acrylate of Synthesis Example 3 in the surface protective layer coating solution of Example 1.

(Example 5)
<Production of electrophotographic photoreceptor>
In the surface protective layer coating liquid of Example 1, the same procedure as in Example 1 was carried out except that 3 parts by mass of the urethane acrylate of Synthesis Example 1 was replaced with 7.5 parts by mass of the urethane acrylate of Synthesis Example 1. A photoconductor was prepared.

(Example 6)
<Production of electrophotographic photoreceptor>
In the surface protective layer coating liquid of Example 1, the same procedure as in Example 1 was conducted except that 3 parts by mass of the urethane acrylate of Synthesis Example 1 was replaced with 0.15 parts by mass of the urethane acrylate of Synthesis Example 1. A photoconductor was prepared.

(Example 7)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the tri- or higher functional radical polymerizable compound in the surface protective layer coating solution of Example 1 was changed to the following.
・ Trifunctional or higher radical polymerizable compound (dipentaerythritol hexaacrylate, KAYARAD DPHA,
Nippon Kayaku Co., Ltd.) 75 parts by mass

(Example 8)
<Production of electrophotographic photoreceptor>
In the surface protective layer coating solution of Example 1, Exemplified Compound No. 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 represented by 7 was changed to the following.
-Radical polymerizable compound having charge transporting structure (Exemplary Compound No. 38)
... 95 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 of Example 1 was replaced with the following surface protective layer coating solution.
-Surface protective layer coating solution-
-Urethane acrylate of Synthesis Example 1 (50 wt% solution) ... 3 parts by mass-Trifunctional or higher-functional radical polymerizable compound (trimethylolpropane triacrylate, TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.)
... 75 parts by mass-Exemplified Compound No. Radical polymerizable compound having a charge transporting structure represented by 7
... 75 parts by mass-Photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone, Irgacure 184,
Ciba Specialty Chemicals Co., Ltd.) 7.5 parts by mass Tetrahydrofuran ... 1,200 parts by mass Filler (alumina filler, AA-03, manufactured by Sumitomo Chemical Co., Ltd.) 8 parts by mass

(Example 10)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the charge transport layer coating solution of Example 9 was changed to the following filler.
・ Filler (alumina filler, AA-03, manufactured by Sumitomo Chemical Co., Ltd.) ... 40 parts by mass

(Comparative Example 1)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the urethane acrylate of Synthesis Example 1 was changed to the urethane acrylate produced in Comparative Synthesis Example 1 in the surface protective layer coating solution of Example 1. .

(Comparative Example 2)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the urethane acrylate of Synthesis Example 1 was changed to the ethoxylated isocyanuric acid triacrylate shown below in the surface protective layer coating solution of Example 1. .

(Comparative Example 3)
<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 of Example 1 did not contain the urethane acrylate of Synthesis Example 1.

(Comparative Example 4)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the tri- or higher functional radical polymerizable compound in the surface protective layer coating solution of Example 1 was changed to the following.
-Bifunctional radically polymerizable compound (Bifunctional acrylate: KAYARAD NPGDA, manufactured by Nippon Kayaku)
... 75 parts by mass

次に、作製した各電子写真感光体を、プロセスカートリッジに装着し、株式会社リコー製ｉｍaｇｉｏ ＭＰ９００１にて、連続して合計５０万枚の実機通紙試験を行い、以下のようにして、転写率測定、摩耗量測定、及び画像評価を行った。結果を表に示す。 (Comparative Example 5)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the radical polymerizable compound having a charge transporting structure in the surface protective layer coating solution of Example 1 was changed to the following.
-Charge transport material represented by the following structural formula: 75 parts by mass

Next, each produced electrophotographic photosensitive member is mounted on a process cartridge, and a real paper passing test of a total of 500,000 sheets is continuously performed with imago MP9001 manufactured by Ricoh Co., Ltd., and the transfer rate is as follows. Measurement, wear measurement, and image evaluation were performed. The results are shown in the table.

(Transfer rate measurement)
The following evaluation was performed before and after 500,000 sheets were passed. First, a solid black image with an image area of 2 cm ² was output, and the apparatus was stopped before the toner on the photoconductor was transferred to the transfer paper, and the amount of toner on the photoconductor was determined. Subsequently, a black solid image having an image area of 2 cm ² was output again, and the apparatus was stopped immediately after the toner on the photoconductor was transferred to the transfer paper, and the amount of toner on the photoconductor was determined. Based on the above results, the transfer rate was measured by measuring the ratio of the amount of untransferred toner on the photoreceptor.

<Abrasion amount>
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.

<Image evaluation>
After passing 500,000 sheets, output two A3 size images of white pattern, black pattern, and halftone pattern using imgio MP9001 manufactured by Ricoh Co., Ltd. used in the actual machine passing test. confirmed.

  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 10 Photoconductor 11 Charging charger 12 Image exposure part 13 Developing unit 14 Registration roller 15 Recording medium 16 Transfer charger 17 Cleaning blade 18 Static elimination lamp 101 Photoconductor 102 Charging means 103 Exposure 104 Developing means 105 Recording medium 106 Transfer means 107 Cleaning means 201 Support Body 202 Photosensitive layer 203 Surface protective layer 204 Charge generation layer 205 Charge transport layer

Patent No. 4208367 Japanese Patent No. 4160512 JP-A-6-95413 Patent No. 3938209 Patent No. 4214655 JP 2007-193309 A JP 2009-104146 A JP2007-025676 JP 2003-066642 A

Claims (6)

A support, and at least a photosensitive layer and a surface protective layer on the support;
The surface protective layer is
Urethane acrylate containing at least a perfluoropolyether moiety;
A tri- or higher functional radical polymerizable monomer;
An electrophotographic photoreceptor comprising a cured product with a radical polymerizable compound having a charge transporting structure.   2. The electrophotographic photosensitive member according to claim 1, wherein the urethane acrylate containing a perfluoropolyether moiety is a bifunctional acrylate having an isocyanurate skeleton.   The cured product is a cured product of 0.1 to 5 parts by mass of urethane acrylate containing a perfluoropolyether portion with respect to 100 parts by mass of a tri- or higher functional radical polymerizable monomer. The electrophotographic photoreceptor described in 1.   The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains a filler. The electrophotographic photosensitive member according to any one of claims 1 to 4, and at least one unit selected from a charging unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit,
Process cartridge characterized by being detachable from the image forming apparatus main body An electrophotographic photosensitive member; a charging unit that charges the surface of the electrophotographic photosensitive member; an exposing unit that exposes the surface of the charged electrophotographic photosensitive member to form an electrostatic latent image; and An image forming apparatus comprising at least a developing unit that develops a visible image using the developing unit, 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 Because
An image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.

Images