JP2006243506A - Electrophotographic photoreceptor, and image forming apparatus, process cartridge and image forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which hardly deteriorates its surface, in a charging system by proximity discharge with an AC voltage superimposed on a DC voltage, has very good mechanical durability, and enables long-term stable image formation. <P>SOLUTION: The electrophotographic photoreceptor is used in an image forming apparatus including: a charger which is disposed in contact with or in proximity to the electrophotographic photoreceptor and charges the photoreceptor by discharge caused by applying a voltage with an AC component superimposed on a DC component; a latent image forming unit for forming an electrostatic latent image on the surface of the photoreceptor; and a developing unit for depositing toner on the image part of the electrostatic latent image. The photoreceptor has at least a photosensitive layer 32 on a conductive support, wherein a self-restoring resin is contained in the photosensitive layer 32. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member effective for an electrophotographic process having a charger for charging an electrophotographic photosensitive member using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component, and the same. The present invention relates to an image forming apparatus, a process cartridge, and an image forming method.

In recent years, miniaturization and higher image quality have been demanded for electrophotographic apparatuses from the viewpoints of saving office space and expanding business opportunities.
Many attempts have been made to improve the electrophotographic process in order to reduce the size of the electrophotographic apparatus. In the charging process, a charging method using proximity discharge tends to be adopted. This is a system in which a charging member is brought into contact with the surface of the electrophotographic photosensitive member, or a charging member is disposed in the vicinity without contact to generate a proximity discharge to charge the surface of the electrophotographic photosensitive member. If this method is used, a large-scale charging device is not required, and thus it is very effective for downsizing the device. Also, recent proximity charging systems often employ a system in which an AC voltage is superimposed on a DC voltage and applied in order to achieve uniform charging on the electrophotographic photosensitive member.
However, the charging method using proximity discharge in which AC voltage is superimposed on DC voltage concentrates the discharge near the surface of the electrophotographic photosensitive member, so that the surface of the electrophotographic photosensitive member is deteriorated and the thickness of the electrophotographic photosensitive member is greatly reduced. all right. Deterioration of the electrophotographic photosensitive member surface due to proximity discharge occurs even when there is no contact member to the image carrier, unlike mechanical rubbing. For this reason, development of an electrophotographic photosensitive member having durability against proximity discharge or a technology for protecting the surface of the electrophotographic photosensitive member is strongly desired.

The deterioration mechanism of the electrophotographic photoreceptor surface due to proximity discharge will be described below.
FIG. 1 shows a state in which only a charging member is placed close to the surface of the electrophotographic photosensitive member in a non-contact state in order to investigate the deterioration state of the surface of the electrophotographic photosensitive member due to proximity discharge, and a charging experiment is performed for about 150 hours continuously. 3 is a result of measuring a change in film thickness on the surface of the electrophotographic photosensitive member.
The electrophotographic photosensitive member used in the experiment is an organic photosensitive member using polycarbonate for the charge transport layer, and all the members in contact with the electrophotographic photosensitive member are removed, and an alternating voltage in which an alternating voltage is superimposed on a direct current voltage is applied. Charging was performed using a non-contact charging roller. As a result, it was found that the amount of film scraping on the surface of the electrophotographic photosensitive member gradually increased and the film thickness of the electrophotographic photosensitive member gradually decreased. The mechanism of film thickness reduction has not been clarified at present. However, when an electrophotographic photosensitive member having a reduced film thickness is analyzed, the polycarbonate constituting the electrophotographic photosensitive member is considered to have been decomposed. Acid etc. were detected. Since such a substance has been detected, the following may be considered as a mechanism for reducing the film thickness of the electrophotographic photosensitive member.

FIGS. 2A and 2B show the state of the surface of the electrophotographic photosensitive member when the surface of the electrophotographic photosensitive member 1 deteriorates due to the proximity discharge, with the charging roller 2a facing the surface of the electrophotographic photosensitive member with a minute gap. It is explanatory drawing shown taking the state as an example.
As shown in FIG. 2A, when proximity discharge is performed, the energy of particles (ozone, electrons, excited molecules, ions, plasma, etc.) generated by the discharge is discharged in the discharge region on the surface of the electrophotographic photoreceptor. Irradiated to the charge transport layer 1a on the surface. This energy resonates and is absorbed by the binding energy of the molecules constituting the surface of the electrophotographic photosensitive member, and as shown in FIG. 2 (b), the charge transport layer 1a has a lower molecular weight due to the breakage of the resin molecular chain, Chemical degradation such as a decrease in the degree of entanglement occurs. It is considered that the thickness of the charge transport layer 1a on the surface of the electrophotographic photoreceptor gradually decreases due to the chemical deterioration of the electrophotographic photoreceptor due to such proximity discharge.
This problem is not only a problem that occurs in a photoreceptor using polycarbonate, but polyarylate (Patent Document 1), polystyrene (Patent Document 2), acrylic resin (Patent Document 3), urethane resin (Patent Document 4), etc. are used. A similar reduction in film thickness occurs in the existing photoreceptor, and this problem has not been solved.
In addition, the self-restoring resin described below is publicly known and is described in detail in Patent Document 5, Non-Patent Document 1, and the like.

JP 2003-195564 A Japanese Patent Laid-Open No. 10-90932 Japanese Patent No. 3164426 JP 2004-12865 A JP 2001-81304 A "Self-healing materials that have come so far", Self-healing Materials Study Group, Industrial Research Committee

  An object of the present invention is to form a stable image over a long period of time in a charging method using proximity discharge in which an AC voltage is superimposed on a DC voltage, with little deterioration on the surface of the electrophotographic photosensitive member, and very good mechanical durability. And an image forming apparatus using the same, a process cartridge, and an image forming method.

The invention of claim 1 utilizes at least an electrophotographic photosensitive member and a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component provided in contact with or close to the electrophotographic photosensitive member. A charger for charging the electrophotographic photosensitive member, a latent image forming device for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger, and an electrostatic latent image formed by the latent image forming device. An electrophotographic photosensitive member used in an image forming apparatus having a developing unit for attaching toner to an image portion of an image, wherein the electrophotographic photosensitive member has at least a photosensitive layer on a conductive support, and the electrophotographic photosensitive member is provided. An electrophotographic photosensitive member characterized in that a self-recovering resin is contained in a layer constituting the surface of the photosensitive member.
The invention according to claim 2 is the electrophotographic photoreceptor according to claim 1, wherein the self-healing resin contains an effective amount of a catalyst that can be substantially synthesized from a monomer or an oligomer constituting the resin. is there.
The invention according to claim 3 is the electrophotographic photoreceptor according to claim 2, wherein the catalyst is a copper amine catalyst, a manganese chelate catalyst, potassium carbonate or sodium carbonate.
The invention according to claim 4 is the electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the self-healing resin is polyphenylene ether or a resin composition containing polyphenylene ether.
The invention according to claim 5 is the electrophotographic photoreceptor according to any one of claims 1 to 3, wherein the self-healing resin is polycarbonate or a resin composition containing polycarbonate.
The invention according to claim 6 is the electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the self-healing resin is polyarylate or a resin composition containing polyarylate.
The invention according to claim 7 is the electrophotographic photoreceptor according to any one of claims 1 to 6, wherein the electrophotographic photoreceptor has a structure in which a photosensitive layer and a surface layer are laminated.
The invention according to claim 8 is the electrophotographic photosensitive member according to any one of claims 1 to 7, wherein the self-healing resin is a resin composition containing a charge transport material.
The invention according to claim 9 is the electrophotographic photosensitive member according to claim 2, wherein the amount of the catalyst is 0.00001 to 1 mass% with respect to the self-recovering resin.
The tenth aspect of the present invention is the electrophotographic photosensitive member according to any one of the first to ninth aspects, wherein the photosensitive layer has a structure in which a charge generation layer and a charge transport layer are laminated in this order.
The invention of claim 11 utilizes at least an electrophotographic photosensitive member and a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component provided in contact with or in proximity to the electrophotographic photosensitive member. A charger for charging the electrophotographic photosensitive member, a latent image forming device for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger, and an electrostatic latent image formed by the latent image forming device. An image forming apparatus comprising: a developing unit that attaches toner to an image portion of an image, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. is there.
A twelfth aspect of the present invention is a process cartridge comprising the electrophotographic photosensitive member according to any one of the first to tenth aspects.
A thirteenth aspect of the present invention is an image forming method using the electrophotographic photosensitive member according to any one of the first to tenth aspects.

  According to the present invention, in a charging method using proximity discharge in which an alternating voltage is superimposed on a direct current voltage, the surface of the electrophotographic photosensitive member is less deteriorated, the mechanical durability is very good, and stable image formation over a long period of time. An electrophotographic photosensitive member capable of performing the above, an image forming apparatus using the same, a process cartridge, and an image forming method are provided.

Hereinafter, the present invention will be described in detail.
The electrophotographic photosensitive member of the present invention is particularly effective in an electrophotographic process having a charger that charges the electrophotographic photosensitive member by using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component. .

As a result of intensive studies by the present inventors, the electrophotographic photoreceptor of the present invention is not only mechanically durable when using a charger using a charging method by proximity discharge in which an AC voltage is superimposed on a DC voltage, It has been found that it has extremely high durability against energy irradiation of particles (ozone, electrons, excited molecules, ions, plasma, etc.) generated by discharge.
As a cause of this, the self-healing resin has a function of actively repairing and restoring the original state even if the molecular chain is broken by the energy of the particles generated by the discharge colliding with the surface of the photoreceptor. It is inferred that

  In addition, an effective amount of catalyst may be included to promote self-healing properties. Examples of this catalyst include copper amine-based catalysts, manganese chelate-based catalysts, and carbonate-based catalysts (such as potassium carbonate and sodium carbonate). It is. These catalysts may be used in one type of catalyst system, or may be a mixed system in which several types of catalysts are mixed. The amount of the catalyst used is not particularly limited, but may be an amount necessary for exhibiting the desired self-healing ability. An amount of 0.00001 to 1% by weight with respect to the self-healing resin is suitable. Particularly suitable among the catalyst systems is a catalyst system that is highly active when the corresponding monomer or oligomer is polymerized in an oxygen-containing atmosphere to obtain a polyphenylene ether. An example of such a highly active catalyst is the use of a diamine catalyst as a copper amine catalyst. Examples of such a catalyst include a copper / bidentate tertiary amine catalyst described in JP-A-49-41490, JP-A-53-30698, JP-A-59-131627, Copper compounds / secondary diamines / tertiary monoamines / bromine compounds / secondary monoamine type catalysts described in Japanese Laid-Open Patent Publication Nos. 59-196318, JP-A 63-135423, JP-A 63-142029, JP Copper compounds / tertiary diamines and special secondary amines described in JP-A-63-304025, JP-A-64-119, JP-A-1-45427, JP-A-1-33131, and JP-A-1-158035 Using a catalyst system such as that described above, a method using a special anion in a copper diamine catalyst system described in JP-A-10-87818, a copper / asymmetric dia described in JP-A-10-237172 The method used down like those exemplified as described in JP. Similarly, examples of highly active manganese chelate catalyst systems include, for example, manganese / hydroxyoxime catalyst systems described in JP-A-51-34995 and JP-A-51-34996, and JP-A-51-87600. Manganese / hydroxyarene oxime catalyst system, manganese / phenylbenzoin oxime catalyst described in JP-A-53-79992, chelate catalyst system based on a polymer containing manganese / benzoin oxime described in JP-A-53-79994, JP Manganese / orthohydroxyazo compound-based catalyst described in Japanese Patent Laid-Open No. 58-19329, manganese / salicylidenediamine or triamine-based catalyst described in Japanese Patent Laid-Open No. 62-86019, and Japanese Patent Laid-Open No. 62-95319 Manganese / bissalicylidenediamine catalyst, etc. Examples described are exemplified.

  Examples of the resin having a self-healing property include polyphenylene ether, polycarbonate, polyarylate, etc., and the expression of these resin compositions is not limited as long as the self-healing property is not hindered, or includes an organic compound. Say. Examples of the organic compound include a plasticizer and a charge transport material.

  Specifically, as polyphenylene ether, for example, poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-diethyl) -1,4-phenylene) ether, poly (2-methyl-6-n-propyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n-propyl-1,4-phenylene) ether, poly (2-methyl-6-i-propyl-1,4-phenylene) ether, poly (2-ethyl-6-i-propyl) -1,4-phenylene) ether, poly (2,6-di-i-propyl-1,4-phenylene) ether, poly (2-methyl-6-phenyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2-methyl-6-chloro-1,4-phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) Ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether, poly (2-methyl-6-methoxy-1,4-phenylene) ether, poly (2-methyl-1,4-phenylene) Examples include homopolymers such as ether, poly (-1,4-phenylene) ether, poly (2,6-di (p-fluorophenyl) -1,4-phenylene) ether, and examples of the copolymer. For example, a copolymer of 2,6-dimethylphenol and o-cresol, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, etc. Polyphenylene ether copolymers comprising a polyphenylene ether structure as a main component can be mentioned. Specific examples of polycarbonate and polyarylate include those derived from the following monomers constituting them. Also included are resins obtained by mixing two or more of these. Specific examples of the monomer include bis (4-hydroxyphenyl) methane, bis (2-methyl-4-hydroxyphenyl) methane, bis (3-methyl-4-hydroxyphenyl) methane, 1,1-bis (4- Hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) -1 -Phenylethane, 1,3-bis (4-hydroxyphenyl) -1,1-dimethylpropane, 2,2-bis (4-hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3- Hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 2,2- Su (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, bis ( 3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2 -Bis (3-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-tert-butyl-4-hydroxyphenyl) propane, , 2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3,5-dichloro-4-) Hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy) Phenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclo Hexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dichloro- 4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) cycloheptane, 2,2-bis (4- Hydroxyphenyl) norbornane, 2,2-bis (4-hydroxyphenyl) adamantane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, ethylene glycol bis (4-hydroxyphenyl) Ether, 1,3-bis (4-hydroxyphenoxy) benzene 1,4-bis (3-hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenyl sulfide, 3,3′-dimethyl-4,4′-dihydroxydiphenyl sulfide, 3,3 ′, 5,5′-tetramethyl -4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 3,3'-dimethyl -4,4'-dihydroxydiphenylsulfone, 3,3'-diphenyl-4,4'-dihydroxydiphenylsulfone, 3,3'-dichloro-4,4'-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) ketone Bis (3-methyl-4-hydroxyphenyl) ketone 3,3,3 ′, 3′-tetramethyl-6,6′-dihydroxyspiro (bis) indane, 3,3 ′, 4,4′-tetrahydro-4,4,4 ′, 4′-tetramethyl- 2,2′-spirobis (2H-1-benzopyran) -7,7′-diol, trans-2,3-bis (4-hydroxyphenyl) -2-butene, 9,9-bis (4-hydroxyphenyl) ) Fluorene, 9,9-bis (4-hydroxyphenyl) xanthene, 1,6-bis (4-hydroxyphenyl) -1,6-hexanedione, α, α, α ′, α′-tetramethyl-α, α′-bis (4-hydroxyphenyl) -p-xylene, α, α, α ′, α′-tetramethyl-α, α′-bis (4-hydroxyphenyl) -m-xylene, 2,6-dihydroxy Dibenzo-p-dioxin, 2,6 -Dihydroxythianthrene, 2,7-dihydroxyphenoxathiin, 9,10-dimethyl-2,7-dihydroxyphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, 4,4'-dihydroxybiphenyl, 1,4-dihydroxynaphthalene, 2,7-dihydroxypyrene, hydroquinone, resorcin, 4-hydroxyphenyl-4-hydroxybenzoate, ethylene glycol-bis (4-hydroxybenzoate), diethylene glycol-bis (4-hydroxybenzoate), tri Ethylene glycol-bis (4-hydroxybenzoate), p-phenylene-bis (4-hydroxybenzoate), 1,6-bis (4-hydroxybenzoyloxy) -1H, 1H, 6H, 6H- -Fluorohexane, 1,4-bis (4-hydroxybenzoyloxy) -1H, 1H, 4H, 4H-perfluorobutane, 1,3-bis (4-hydroxyphenyl) tetramethyldisiloxane, phenol-modified silicone oil, etc. Is mentioned.

  Specific examples of the plasticizer, the charge transport material, and the antioxidant will be described below.

Hereinafter, the layer structure of the present invention will be described.
<About the layer structure of the electrophotographic photoreceptor>
The electrophotographic photosensitive member used in the present invention will be described with reference to the drawings.
FIG. 3 is a cross-sectional view showing the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member has a single layer structure in which a photosensitive layer 32 having a charge generating function and a charge transporting function is provided on a conductive support 31. Is the body. In this case, the photosensitive layer 32 contains a self-repairing resin.
FIG. 4 shows a surface layer 33 provided on the photosensitive layer 32 of FIG. In this case, the surface layer 33 contains a self-repairing resin.
FIG. 5 shows an electrophotographic photosensitive member having a laminated structure in which a charge generation layer 321 having a charge generation function and a charge transport layer 322 having a charge transport material function are laminated on a conductive support 31. In this case, the charge transport layer 322 contains a self-repairing resin.
6 shows a structure in which a surface layer 33 is provided on the charge transport layer 322 of FIG. In this case, the surface layer 33 contains a self-repairing resin.

<About conductive support>
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. After metal oxide is deposited or sputtered, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. Pipes that have been subjected to surface treatment such as cutting, super-finishing, and polishing can be used. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.
In addition, the conductive support dispersed in an appropriate binder resin on the support can be used as the conductive support of the present invention.
Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. Can be mentioned. The binder resin used at the same time includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as resins, urethane resins, phenol resins, and alkyd resins. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.
Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support of the present invention.

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

<Photosensitive layer with a laminated structure>
(About the charge generation layer)
The charge generation layer is a layer mainly composed of a charge generation material having a charge generation function, and a binder resin can be used in combination as necessary. As the charge generation material, inorganic materials and organic materials can be used.
Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, and amorphous silicon. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.
On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, azo pigments having a distyryl oxadiazole skeleton, azo pigments having a distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generation materials can be used alone or as a mixture of two or more.

As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Examples include polyacrylamide. These binder resins can be used alone or as a mixture of two or more. In addition to the binder resin described above as a binder resin for the charge generation layer, a polymer charge transport material having a charge transport function, such as an arylamine skeleton, benzidine skeleton, hydrazone skeleton, carbazole skeleton, stilbene skeleton, pyrazoline skeleton, etc. Polymer materials such as polycarbonate, polyester, polyurethane, polyether, polysiloxane, and acrylic resin, polymer materials having a polysilane skeleton, and the like can be used.
Specific examples of the former include JP-A-01-001728, JP-A-01-009964, JP-A-01-013061, JP-A-01-019049, JP-A-01-241559, No. 04-011627, No. 04-175337, No. 04-183719, No. 04-2225014, No. 04-230767, No. 04-320420, No. 05 -232727, JP-A 05-310904, JP-A 06-234836, JP-A 06-234837, JP-A 06-234838, JP-A 06-234839, JP-A 06-234840. No. 1, JP-A 06-234841, JP-A 06-239049, Japanese Unexamined Patent Publication Nos. 06-236050, 06-236051, 06-295077, 07-0756374, 08-176293, 08-208820, 08 No. -21640, JP 08-252868, JP 08-269183, JP 09-062019, JP 09-038883, JP 09-71642, JP 09-87376. JP-A 09-104746, JP-A 09-110974, JP-A 09-110976, JP-A 09-157378, JP-A 09-221544, JP-A 09-227669. JP-A 09-228367, JP-A 09-241369 Charge transporting polymer materials described in JP 09-268226 A, JP 09-272728 A, JP 09-302084 A, JP 09-302085 A, JP 09-328539 A, etc. Can be mentioned.
Specific examples of the latter include polysilylene polymers described in, for example, JP-A No. 63-285552, JP-A No. 05-19497, JP-A No. 05-70595, JP-A No. 10-73944, and the like. Illustrated.

The charge generation layer may contain a charge transport material.
Charge transport materials that can be used in the charge generation layer include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and diphenoquinone derivatives. These electron transport materials can be used alone or as a mixture of two or more.
Examples of the hole transporting material include the electron donating materials shown below and are used favorably. As hole transport materials, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triaryls Other known materials such as methane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, and the like can be given. These hole transport materials can be used alone or as a mixture of two or more.
Methods for forming the charge generation layer include a vacuum thin film preparation method and a casting method from a solution dispersion system.
As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.
In addition, in order to provide a charge generation layer by the casting method described later, if necessary, the inorganic or organic charge generation material together with a binder resin, tetrahydrofuran, dioxane, dioxolane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, cyclohexane. Can be formed by dispersing with a ball mill, attritor, sand mill, bead mill, etc. using a solvent such as pentanone, anisole, xylene, methyl ethyl ketone, acetone, ethyl acetate, butyl acetate, etc. . Moreover, leveling agents, such as a dimethyl silicone oil and a methylphenyl silicone oil, can be added as needed. The coating can be performed using a dip coating method, spray coating, bead coating, ring coating method or the like.
The thickness of the charge generation layer provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

(About charge transport layer)
The charge transport layer is a layer having a charge transport function.
The charge transport layer is formed by dissolving or dispersing a charge transport material having a charge transport function and a binder resin in an appropriate solvent, and coating and drying the solution on the charge generation layer.
As the charge transport material, the electron transport material and the hole transport material described in the charge generation layer can be used.
Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin.
As the solvent used for the charge transport layer, the same solvent as that for the charge generation layer can be used, but a solvent that dissolves the charge transport material and the binder resin well is suitable. These solvents may be used alone or in combination of two or more. The 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 that can be used in combination with the charge transport layer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is 0 to 100 parts by mass of the binder resin. About 30 parts by mass is appropriate.
Examples of leveling agents that can be used in the charge transport layer include silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain. About 0-1 mass part is suitable with respect to a mass part.
The thickness of the charge transport layer is suitably about 5 to 40 μm, preferably about 10 to 30 μm.

<Single photosensitive layer>
A photosensitive layer having a single layer structure is a layer having both a charge generation function and a charge transport function.
The photosensitive layer can be formed by dissolving or dispersing a charge generation material having a charge generation function, a charge transport material having a charge transport function, and a binder resin in an appropriate solvent, and applying and drying the solution. Moreover, a plasticizer, a leveling agent, etc. can also be added as needed. As the charge generation material dispersion method, the charge generation material, the charge transport material, the plasticizer, and the leveling agent may be the same as those already described in the charge generation layer and the charge transport layer. As the binder resin, in addition to the binder resin previously mentioned in the section of 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 mentioned above can also be used. The film thickness of the photosensitive layer is suitably about 5 to 30 μm, preferably about 10 to 25 μm.
The charge generation material contained in the photosensitive layer having a single layer structure is preferably 1 to 30% by mass based on the total amount of the photosensitive layer, the binder resin contained in the photosensitive layer is 20 to 80% by mass, and the charge transport material is 10%. ~ 70% by weight is used favorably.

<Contains self-healing resin in photosensitive layer>
When the single layer and the laminated photosensitive layer are the outermost layer, the outermost layer portion is made of a self-repairing resin or a resin composition. In the case of a single layer structure, a film is formed with a charge generating material having a charge generating function, a charge transporting material having a charge transporting function, and a self-healing resin or resin composition.
In the case of a laminated structure, a film is formed with a charge transport material used as a charge transport layer and a self-healing resin or resin composition.

<About surface layer>
In the photoreceptor of the present invention, a surface layer made of a self-healing resin or resin composition may be provided on the photosensitive layer.
It can be formed by dissolving or dispersing the self-healing resin or resin composition in an appropriate solvent, and applying and drying it.
If necessary, an appropriate amount of a charge transport material, a plasticizer, an antioxidant, a leveling agent, and the like can be added. The means for mixing the self-healing resin and the catalyst is not particularly limited, and examples thereof include simple stirring addition, solvent dissolution, mixing by dispersion, mixing by a mixer, and kneading.
Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. And ethers such as dichloromethane, dichloroethane, trichloroethane, and chlorobenzene, aromatics such as benzene, toluene, and xylene, and cellosolves such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary.
As a method of providing a surface layer on the photosensitive layer, a dip coating method, a ring coating method, a spray coating method, or the like is used.
Among these, a general method for forming a surface layer is a spray that forms a coating film by depositing fine droplets generated by discharging a paint from a nozzle having a fine opening and atomizing it onto the photosensitive layer. A coating method is used.
The thickness of the surface layer is preferably in the range of 1.0 to 10.0 μm. If it is too thin, it tends to wear out and disappear during long-term use, and if it is thick, it can be considered that the residual potential increases and the fine dot reproducibility decreases.

<About the undercoat layer>
In the electrophotographic photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.
These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodization, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. The thickness of the undercoat layer is suitably from 0 to 5 μm.

<Addition of antioxidant to each layer>
In the present invention, in order to improve environmental resistance, the surface layer, the charge generation layer, the charge transport layer, the undercoat layer, etc. An antioxidant can be added to each layer such as an intermediate layer provided.
These antioxidants are known as additives such as rubbers, plastics, fats and oils, and commercially available products can be easily obtained.
The addition amount of the antioxidant in this invention is 0.01-10 mass% with respect to the total mass of the layer to add.

<Image Forming Method and Apparatus>
Embodiments of an image forming apparatus to which the present invention is applied will be described below. However, these are just examples, and the present invention is not limited to these. FIG. 7 shows an example of an image forming apparatus having a configuration common to the embodiments described later. This image forming apparatus includes an electrophotographic photosensitive member made of an organic photosensitive member. The electrophotographic photoreceptor 1 is characterized in that it has at least a photosensitive layer and is a film containing a self-restoring resin or a resin composition in the vicinity of the surface of the photoreceptor.

<About the overall configuration>
In FIG. 7, the electrophotographic photosensitive member 1 is rotationally driven by a driving device (not shown), and the surface thereof is charged to a predetermined polarity by a charging roller 2a of a charging device 2 of a proximity charging type. The surface of the charged electrophotographic photosensitive member 1 is exposed by the exposure device 3 to form an electrostatic latent image corresponding to the image information. The electrostatic latent image is developed with toner as a developer supplied from the developing device 4 to the surface of the electrophotographic photosensitive member 1 to be visualized as a toner image.
On the other hand, a transfer sheet as a recording medium is fed toward the electrophotographic photosensitive member 1 from a paper feeding unit (not shown). A toner image on the electrophotographic photosensitive member 1 is transferred onto the transfer paper on the transfer paper by a transfer device 5 disposed opposite to the electrophotographic photosensitive member 1. The transfer paper onto which the toner image has been transferred is separated from the electrophotographic photosensitive member 1 and then conveyed to the fixing device 6 along the transfer material conveyance path 10 to fix the toner image. Transfer residual toner as residual toner remaining on the electrophotographic photosensitive member 1 after the toner image is transferred to the transfer paper is removed from the electrophotographic photosensitive member 1 by the cleaning device 7. Further, the residual charge on the surface of the electrophotographic photosensitive member after the transfer residual toner is removed is removed by the static eliminator 9. In this way, the electrophotographic photoreceptor 1 is repeatedly used.
In the image forming apparatus according to the present embodiment, the electrophotographic photosensitive member, the charging member, the developing device, and the cleaning device are integrally configured as a process cartridge that is detachable from the image forming apparatus main body.

<About charging>
Next, the charging device 2 used in the image forming apparatus will be described. The charging device 2 charges the electrophotographic photosensitive member using proximity discharge. As a method of charging the electrophotographic photosensitive member using proximity discharge, a contact charging method in which a rotatable roller-shaped charging member (hereinafter referred to as a charging roller) 2a is placed in contact with the electrophotographic photosensitive member, and charging is performed. There is a non-contact charging method in which a roller is disposed in a non-contact manner on an electrophotographic photosensitive member. In this embodiment, a non-contact charging method is used.
The present invention can also be applied to a contact charging method. However, in the contact charging method, it is preferable to use an elastic member that improves the contact property with the surface of the electrophotographic photosensitive member and does not apply mechanical stress to the electrophotographic photosensitive member. However, when an elastic member is used, the charging nip width is widened, which may cause the protective material to easily adhere to the charging roller side. Therefore, it is more advantageous to adopt a non-contact charging method for high durability. In the present embodiment, a non-contact charging method is adopted in which the charging roller 2a is disposed so as to face at least an image forming area on the surface of the electrophotographic photosensitive member with a predetermined charging gap.

FIG. 8 is an explanatory diagram of the charging device 2 used in the image forming apparatus of the present embodiment.
The charging roller includes a shaft portion 21a and a roller portion 21b. The roller portion 21 b can be rotated by the rotation of the shaft portion 21 a, and a portion of the surface of the electrophotographic photosensitive member 1 that faces the image forming region 11 where an image is formed is not in contact with the electrophotographic photosensitive member 1. The length of the charging roller in the longitudinal direction (axial direction) is set slightly longer than the image forming area, and spacers 22 are provided at both ends in the longitudinal direction. By bringing these two spacers into contact with the non-image forming regions 12 at both ends of the electrophotographic photosensitive member surface, a minute gap 14 is formed between the electrophotographic photosensitive member 1 and the charging roller. The minute gap 14 is configured such that the distance at the closest portion between the charging roller and the electrophotographic photosensitive member 1 can be maintained at 1 to 100 μm. A more preferable range of the gap 14 is 10 to 80 μm, and more preferably 30 to 65 μm. In the apparatus of this embodiment, the gap 14 is set to 50 μm. Further, the shaft portion 21a is pressed against the electrophotographic photosensitive member side by a pressing spring 15 made of a spring. Thereby, the minute gap 14 can be accurately maintained. The charging roller rotates along with the surface of the electrophotographic photosensitive member via the spacer 22.
A charging power source is connected to the charging roller. As a result, the surface of the electrophotographic photosensitive member is uniformly charged by proximity discharge in a minute gap between the surface of the electrophotographic photosensitive member and the surface of the charging roller. As an applied voltage, an AC voltage is superimposed on a DC voltage. When an alternating voltage obtained by superimposing an AC voltage on a DC voltage is used as the applied voltage, the effect of variations in charging potential due to minute gap fluctuations is suppressed, and uniform charging becomes possible. In this embodiment, an alternating voltage obtained by superimposing an AC voltage that is an AC component on a DC voltage that is a DC component is used.
The charging roller has a metal core as a conductive support having a cylindrical shape, and a resistance adjusting layer formed on the outer peripheral surface of the metal core. The surface of the charging roller is preferably hard. A rubber member can also be used as the roller member, but if it is a member that is easily deformed, such as a rubber member, it is difficult to maintain the minute gap 14 with the electrophotographic photosensitive member 1 uniformly, and depending on the image forming conditions, the center of the charging roller Only the portion may suddenly contact the surface of the electrophotographic photosensitive member. The charging roller is preferably a hard member with less deflection when using the non-contact charging method.
Specific examples of the charging roller having a hard surface include, for example, a thermoplastic resin composition (polyethylene, polypropylene, polymethyl methacrylate, polystyrene, and copolymers thereof) in which a polymer ion conductive agent is dispersed in a resistance adjustment layer. In which the surface of the resistance adjustment layer is cured with a curing agent. The cured film treatment is performed, for example, by immersing the resistance adjustment layer in a treatment solution containing an isocyanate-containing compound, but may be performed by forming a cured treatment film layer on the surface of the resistance adjustment layer. In this embodiment, the charging roller is formed with a diameter of 10 mm (diameter 10 mm).
As is apparent from the above description, the electrophotographic photosensitive member of the present invention is not only used in electrophotographic copying machines, but also in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making. Can also be used widely.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited thereby. All parts are based on mass.
Example 1
An undercoat layer was formed on an Al support (outer diameter 30 mmφ) by dipping so that the film thickness after drying was 28 μm.

・ Coating liquid for undercoat layer 6 parts alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin 4 parts (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide 40 parts (CR-EL: Ishihara Sangyo)
50 parts of methyl ethyl ketone

  On this undercoat layer, it was dip-coated in a charge generation layer coating solution containing a bisazo pigment having the following structure and dried by heating to form a charge generation layer having a thickness of 0.2 μm.

-Coating solution for charge generation layer Bisazo pigment having the following chemical formula 1 2.5 parts Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 part Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

  On this charge generation layer, a charge transport layer coating solution having the following structure was dip-coated and heat-dried to obtain a charge transport layer having a thickness of 22 μm.

・ Coating liquid for charge transport layer 10 parts of bisphenol Z type polycarbonate 10 parts of charge transport material having the following chemical formula 2 80 parts of tetrahydrofuran 80 parts of tetrahydrofuran solution of 1% silicone oil (KF50, manufactured by Shin-Etsu Chemical Co., Ltd.)

  On the charge transport layer, a surface layer coating solution having the following constitution was applied by spray coating and dried by heating at 150 ° C. to form a surface layer having a thickness of 5.0 μm.

-Coating liquid for surface layer Charge transport material used for charge transport layer Poly (2,6-dimethyl-1,4-phenylene) ether Mass average molecular weight 50,000 Cupric chloride dihydrate N, N, N, N, -tetramethyldiaminopropane tetrahydrofuran cyclohexanone
<Mixing ratio (mass)>
Charge transport material / poly (2,6-dimethyl-1,4-phenylene) ether / cupric chloride dihydrate / N, N, N, N, -tetramethyldiaminopropane / tetrahydrofuran / cyclohexanone = 4/5 /0.0001/0.0002/170/50

Example 2
It was produced in the same manner as in Example 1 except that polycarbonate Z (mass average molecular weight 40,000) was used instead of the poly (2,6-dimethyl-1,4-phenylene) ether used in Example 1.

Example 3
It was produced in the same manner as in Example 1 except that a polyarylate resin was used instead of the poly (2,6-dimethyl-1,4-phenylene) ether used in Example 1.

Example 4
Example 2 except that 0.0001 part of sodium carbonate was added instead of the catalyst cupric chloride dihydrate / N, N, N, N, -tetramethyldiaminopropane used in Example 1. It produced similarly.

Example 5
Except that the mixing ratio used in Example 1 was set to the following, everything was produced in the same manner as in Example 1.
<Mixing ratio (mass)>
Charge transport material / poly (2,6-dimethyl-1,4-phenylene) ether / cupric chloride dihydrate / N, N, N, N, -tetramethyldiaminopropane / tetrahydrofuran / cyclohexanone = 4/5 /0.00005/0.0001/170/50

Example 6
Except that the mixing ratio used in Example 1 was set to the following, everything was produced in the same manner as in Example 1.
<Mixing ratio (mass)>
Charge transport material / poly (2,6-dimethyl-1,4-phenylene) ether / cupric chloride dihydrate / N, N, N, N, -tetramethyldiaminopropane / tetrahydrofuran / cyclohexanone = 4/5 /0.01/0.03/170/50

Comparative Example 1
All were produced in the same manner as in Example 1 except that the surface layer was not provided.

(Real machine paper test)
Using the Ricoh IPSiO Color CX9000, which has a non-contact charger that applies a voltage in which an AC component is superimposed on a DC component, the actual electrophotographic photosensitive member was tested using an actual machine (A4, NBS Ricoh My Paper, at the start) Photoreceptor surface charging potential -650 V) was performed, and wear characteristics and image (S3 chart) characteristics were evaluated. The results are shown in Tables 1 and 2.

At least the electrophotographic photosensitive member and the electrophotographic photosensitive member are charged by using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component that is in contact with or close to the electrophotographic photosensitive member. Toner is applied to a charger, a latent image forming device that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger, and an image portion of the electrostatic latent image formed by the latent image forming device. In an electrophotographic photosensitive member used in an image forming apparatus having a developing device to be attached, the electrophotographic photosensitive member has at least a photosensitive layer on a conductive support and constitutes the surface of the electrophotographic photosensitive member. Because the layer contains a self-healing resin, the surface of the electrophotographic photosensitive member is hardly deteriorated by charging, has high wear resistance, has good electrical characteristics, and has high durability and high performance. The body can be obtained.
Therefore, by using this electrophotographic photosensitive member, it is possible to provide a high-performance and highly reliable image forming apparatus, process cartridge, and image forming method that can provide good images over a long period of time.

It is a figure which shows the change of the film thickness by the charging load of an electrophotographic photoreceptor. FIG. 6 is a diagram illustrating an example of a state of the surface of the electrophotographic photosensitive member when the surface of the electrophotographic photosensitive member deteriorates due to proximity discharge, in which the charging roller is opposed to the surface of the electrophotographic photosensitive member with a minute gap. It is a schematic cross-sectional view showing an example of the electrophotographic photoreceptor layer configuration of the present invention. It is a schematic cross-sectional view showing an example of the electrophotographic photoreceptor layer configuration of the present invention. It is a schematic cross-sectional view showing an example of the electrophotographic photoreceptor layer configuration of the present invention. It is a schematic cross-sectional view showing an example of the electrophotographic photoreceptor layer configuration of the present invention. It is a figure which shows an example of the image forming apparatus of this invention. It is a figure which shows an example of the charging device which can be utilized for this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photosensitive member 1a Charge transport layer 2 Charging device 2a Charging roller 3 Exposure device 4 Development device 5 Transfer device 6 Fixing device 7 Cleaning device 8 Cleaning blade 9 Static elimination device 11 Image forming region 12 Non-image forming region 15 Pressure spring 21 Charging roller 21a Shaft portion 21b Roller portion 31 Conductive support 32 Photosensitive layer 321 Charge generation layer 322 Charge transport layer 33 Surface layer

Claims (13)

  At least the electrophotographic photosensitive member and the electrophotographic photosensitive member are charged by using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component that is in contact with or close to the electrophotographic photosensitive member. Toner is applied to a charger, a latent image forming device that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger, and an image portion of the electrostatic latent image formed by the latent image forming device. In an electrophotographic photosensitive member used in an image forming apparatus having a developing device to be attached, the electrophotographic photosensitive member has at least a photosensitive layer on a conductive support and constitutes the surface of the electrophotographic photosensitive member. An electrophotographic photosensitive member comprising a self-healing resin in a layer.   2. The electrophotographic photoreceptor according to claim 1, wherein the self-healing resin contains an effective amount of a catalyst that can be substantially synthesized from a monomer or an oligomer constituting the resin.   3. The electrophotographic photosensitive member according to claim 2, wherein the catalyst is a copper amine catalyst, a manganese chelate catalyst, potassium carbonate or sodium carbonate.   The electrophotographic photosensitive member according to claim 1, wherein the self-healing resin is polyphenylene ether or a resin composition containing polyphenylene ether.   The electrophotographic photosensitive member according to claim 1, wherein the self-healing resin is polycarbonate or a resin composition containing polycarbonate.   The electrophotographic photosensitive member according to claim 1, wherein the self-healing resin is polyarylate or a resin composition containing polyarylate.   The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member has a structure in which a photosensitive layer and a surface layer are laminated.   The electrophotographic photosensitive member according to claim 1, wherein the self-healing resin is a resin composition containing a charge transport material.   The electrophotographic photosensitive member according to claim 2, wherein the amount of the catalyst is 0.00001 to 1% by mass with respect to the self-healing resin.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a structure in which a charge generation layer and a charge transport layer are laminated in this order.   At least the electrophotographic photosensitive member and the electrophotographic photosensitive member are charged by using a discharge generated by applying a voltage in which an alternating current component is superimposed on a direct current component that is in contact with or close to the electrophotographic photosensitive member. Toner is applied to a charger, a latent image forming device that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member charged by the charger, and an image portion of the electrostatic latent image formed by the latent image forming device. An image forming apparatus having a developing device to be attached, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1.   A process cartridge comprising the electrophotographic photosensitive member according to claim 1. An image forming method using the electrophotographic photosensitive member according to claim 1.

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