JP5540965B2 - Electrophotographic photosensitive member and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member containing oxytitanium phthalocyanine having a specific crystal form as a charge generating agent, and containing a specific compound as a charge transporting agent, as well as an electrophotographic apparatus using the electrophotographic photosensitive member, The present invention relates to a photographic method and a process cartridge for an electrophotographic apparatus.

  In recent years, long-wavelength light sources such as semiconductor lasers and LEDs have been mainly used as exposure light sources for non-impact printers that employ electrophotography. Furthermore, with the miniaturization and speeding up of copiers and printers, processes for reducing the diameter of electrophotographic photosensitive members and increasing the peripheral speed have been adopted. Therefore, the electrophotographic photosensitive member generally uses a charge generating agent having sensitivity in a long wavelength region. Conventionally, phthalocyanine pigments are often used as such materials. It is well known that the sensitivity of this phthalocyanine pigment varies depending on its crystal form. Further, with the recent power saving, there is an increasing demand for high sensitivity in the electrophotographic photosensitive member in order to suppress the output of the exposure light source of the electrophotographic apparatus such as a printer.

  Among the phthalocyanine pigments, oxytitanium phthalocyanine is mentioned as one having high sensitivity in the long wavelength region. Several crystal types of oxytitanium phthalocyanine have been introduced. Among them, the one showing the maximum diffraction peak at 27.2 ° is considered to be highly sensitive. However, when used in a high-speed process, the potential characteristics of the electrophotographic photosensitive member after repeated use deteriorate, and fog, black streaks, density unevenness, and the like occur in the obtained image. When used in a high-speed process, even if the sensitivity is high, if the photoresponsiveness is not sufficient, charges remain in the photosensitive layer, causing fogging, black streaks and density unevenness in the next electrophotographic process. . As a charge transport agent, it is necessary to have a high charge transport capability, and a combination of a charge generator and a charge transport agent is important.

  Therefore, an electrophotographic photosensitive member having high sensitivity in the long wavelength region, high responsiveness, and stable reproducibility of the electrophotographic characteristics, particularly the initial potential and the potential after repeated use, even after repeated use at high speed is desired. It has been. Even if a charge generating agent having high charge generation efficiency is used, sufficient sensitivity cannot be obtained if the compatibility with the charge transporting agent is poor, and it is also high in various usage environments from high temperature and high humidity to low temperature and low humidity. Quality image is not obtained. The compatibility between charge generating agents and charge transporting agents has been studied from various viewpoints, and it has been studied in the past to use oxytitanium phthalocyanine with a specific crystal structure and indoline-based charge transporting materials in electrophotographic photoreceptors. However, the current situation is not clearly found.

For example, in Patent Document 1 (Japanese Patent Laid-Open No. 3-75660), an electrophotographic photosensitive material using an indoline-based charge transporting material having a specific structure (different from the indoline-based charge transporting agent in the present invention) for the charge transporting layer. The body is disclosed. Similarly, Patent Document 2 (Japanese Patent Laid-Open No. 5-6011) and Patent Document 3 (Japanese Patent Laid-Open No. 11-149170) also disclose different charge transport agents that are close to the structure of the charge transfer agent in the present invention. . On the other hand, we have oxytitanium having a specific crystal structure in which the Bragg angle (2θ ± 0.2 °) 27.2 ° of the X-ray diffraction spectrum has a maximum peak in the specification comparative example of Patent Document 4 (Japanese Patent Application Laid-Open No. 2004-279939). Phthalocyanine and an indoline-based charge transport material having a specific structure (different from the indoline-based charge transport agent in the present invention) have already been disclosed.
However, the charge transfer agents disclosed in Patent Documents 1 to 4 cannot sufficiently satisfy the characteristics required for the electrophotographic photosensitive member described above.

The present invention aims to solve the above-mentioned problems of the prior art, and corresponds to the process of reducing the diameter of the electrophotographic photosensitive member and increasing the peripheral speed as the electrophotographic apparatus such as a copying machine and a printer becomes smaller and faster. The present invention provides an electrophotographic photosensitive member that can be electrophotographic photosensitive member, has high sensitivity and high photoresponsiveness in a long wavelength region, has no deterioration in electrical characteristics even after repeated use, and has high stability. Objective.
Another object of the present invention is to provide an electrophotographic apparatus, an electrophotographic method, and a process cartridge for an electrophotographic apparatus using the electrophotographic photosensitive member.

As a result of intensive studies to solve the above problems, the present inventors have used oxytitanium phthalocyanine exhibiting a specific X-ray diffraction peak as a charge generating agent, and an electrophotographic photoreceptor using a charge transporting agent of a specific compound However, the present inventors have found that the above problems can be solved and have completed the present invention.
That is, the said subject is solved by the following this invention.

(1): An electrophotographic photosensitive member having a conductive support and a photosensitive layer provided on the conductive support, wherein the photosensitive layer includes a binder resin, a charge generating agent, a charge The charge generator contains oxytitanium phthalocyanine, and the oxytitanium phthalocyanine has a Bragg angle (2θ ± 0.2 °) diffraction in an X-ray diffraction spectrum using CuKα as a radiation source. As a peak, it has a maximum peak at 27.2 ° and a peak at 28.6 ° at the same time, and its intensity is less than 20% of the intensity of 27.2 °, and the diffraction peak at the lowest angle side. And having a diffraction peak at 7.3 ° and no diffraction peak in the range of 7.4 ° or more and less than 9.4 °, the charge transfer agent is a compound represented by the following general formula (I): An electrophotographic photosensitive member characterized by containing.

(In the general formula (I), R _{1 to} R ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an alkoxy having 1 to 6 carbon atoms. Represents a group.)

(2) The electrophotographic photosensitive member according to (1), wherein the charge transporting agent contains a compound represented by the following chemical formula (Ia).

(3) The electrophotographic photosensitive member according to (1), wherein the charge transporting agent contains a compound represented by the following chemical formula (Ib).

(4) The electrophotographic photosensitive member according to (1), wherein the charge transporting agent contains a compound represented by the following chemical formula (Ic).

(5) The electrophotographic photosensitive member according to the above (1), wherein the charge transfer agent contains a compound represented by the following chemical formula (Id).

(6) The electrophotographic photosensitive member according to (1), wherein the charge transport agent contains a compound represented by the following chemical formula (Ie).

(7): The electrophotographic photosensitive member according to (1), wherein the photosensitive layer contains a phenol-based antioxidant.

(8) The electrophotographic photosensitive member according to (1), wherein the photosensitive layer contains an amine-based antioxidant.

(9): The electrophotographic photosensitive member according to (1), wherein the photosensitive layer contains a sulfur-based antioxidant.

(10) The electrophotographic photosensitive member according to (1), wherein the photosensitive layer contains a benzotriazole ultraviolet absorber.

(11): The electrophotographic photosensitive member according to any one of the above (1) to (10), charging means for charging the surface of the electrophotographic photosensitive member, and electrostatic charge on the surface of the charged electrophotographic photosensitive member. An electrophotographic process comprising: an exposure unit that forms a latent image; a developing unit that visualizes the electrostatic latent image with toner to form a toner image; and a transfer unit that transfers the toner image onto a recording medium. An electrophotographic apparatus is characterized in that it does not have a neutralizing means for neutralizing a photoreceptor.

(12): a charging step for charging the electrophotographic photosensitive member, an exposure step for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, and forming the toner image by visualizing the electrostatic latent image with toner. An electrophotographic method comprising: a developing step for transferring; and a transferring step for transferring the toner image onto a recording medium, wherein the electrophotographic photosensitive member is any one of (1) to (10) above. The electrophotographic method is characterized in that the time required from the exposure step to the development step is 100 milliseconds or less.

(13) One or more means selected from charging means, exposure means, development means, cleaning means, and transfer means, and the electrophotographic photosensitive member according to any one of (1) to (10) above And a process cartridge for an electrophotographic apparatus.

  According to the present invention, an electrophotographic photosensitive member having high responsiveness and repetitive stability, and an electrophotographic apparatus, an electrophotographic method, and a process cartridge for an electrophotographic apparatus using the electrophotographic photosensitive member are obtained.

The X-ray-diffraction figure of the oxytitanium phthalocyanine composition used suitably for this invention is shown. 1 is a schematic configuration diagram showing a configuration in an eraseless type electrophotographic apparatus which is an embodiment of an electrophotographic apparatus according to the present invention. An X-ray diffraction diagram of α-type oxytitanium phthalocyanine is shown.

<Electrophotographic photoreceptor>
The electrophotographic photoreceptor according to the present invention is an electrophotographic photoreceptor having a conductive support and a photosensitive layer provided on the conductive support, and the photosensitive layer includes a binder resin, A charge generating agent, and a charge transporting agent, the charge generating agent containing oxytitanium phthalocyanine, wherein the oxytitanium phthalocyanine has a Bragg angle (2θ ± 0) in an X-ray diffraction spectrum using CuKα as a radiation source. .2 °) has a maximum peak at 27.2 ° and a peak at 28.6 ° at the same time, and its intensity is less than 20% of the intensity at 27.2 °. The low-angle diffraction peak has a diffraction peak at 7.3 ° and does not have a diffraction peak in the range of 7.4 ° or more and less than 9.4 °. The charge transfer agent has the following general formula (I) Containing a compound represented by

(In the general formula (I), R _{1 to} R ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an alkoxy having 1 to 6 carbon atoms. Represents a group.)

  That is, the electrophotographic photosensitive member of the present invention is one in which oxytitanium phthalocyanine having a specific X-ray diffraction spectrum is contained as a charge generating agent in a photosensitive layer on a conductive support as a substrate.

  A preferred embodiment of an electrophotographic photoreceptor (hereinafter sometimes simply referred to as a photoreceptor) according to the present invention will be described in detail. Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached thereto, but the scope of the present invention is intended to limit the present invention in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

In the present invention, for example, a function-separated electrophotographic image in which a charge generation layer containing at least a charge generation agent is formed on a conductive support and a charge transport layer containing at least a charge transfer agent is formed thereon. A photoreceptor is applied.
Various methods can be used as a method for forming the charge generation layer. For example, a specific phthalocyanine composition described later is used as a charge generation agent, and a coating solution dispersed or dissolved in a suitable solvent together with a binder resin is used. It can be formed by coating on a conductive support as a predetermined base and drying as required.

  The charge transport layer has at least the charge transport agent represented by the general formula (I). For example, the charge transport layer may be formed by placing a charge transport agent on the charge generation layer serving as the base and a binder resin. It can be formed by using and binding.

Various methods can be used as a method for forming the charge transport layer. In general, a coating solution in which a charge transport agent is dispersed or dissolved in a suitable solvent together with a binder resin is used as a base charge generation layer. The method of apply | coating and drying can be used.
Further, the present invention can also be applied to an inversely laminated electrophotographic photosensitive member in which a charge generation layer and a charge transport layer are laminated upside down. Furthermore, the present invention can also be applied to a single layer type electrophotographic photosensitive member containing a charge generating agent and a charge transporting agent in the same layer.

  Examples of the conductive support that can be used in the present invention include aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, indium, and other simple metals and alloys thereof. The body is mentioned. The shape may be a flexible shape such as a sheet shape, a film shape, or a belt shape, or may be an inflexible shape such as a drum shape, and may be endless or endless. The diameter of the conductive support is particularly effective when it is 60 mm or less, preferably 30 mm or less.

  Among these, aluminum alloys such as JIS 3000, JIS 5000, and JIS 6000 are used, and general methods such as an EI (Extension Ironing) method, an ED (Extension Drawing) method, a DI (Drawing Ironing) method, and an II (Impact Ironing) method are used. A conductive support formed by a simple method is preferable, and the surface of the conductive support is further subjected to surface treatment such as diamond cutting or polishing, surface treatment such as anodizing treatment, or these treatments and treatments. Anything such as a non-cutting tube which is not performed may be used.

  Moreover, when using resin as an electroconductive support body, electroconductive agents, such as metal powder and electroconductive carbon, can be contained in resin, and electroconductive resin can also be used as resin for electroconductive support body formation.

  Furthermore, when glass is used for the conductive support, the surface thereof may be coated with tin oxide, indium oxide, or aluminum iodide to provide conductivity.

  Further, an undercoat layer may be formed on the conductive support. This undercoat layer has a function of improving adhesion, a barrier function for preventing an inflow current from an aluminum tube as a conductive support, a defect covering function for the surface of the aluminum tube, and the like. This undercoat layer is made of various resins such as polyethylene resin, acrylic resin, epoxy resin, polycarbonate resin, polyurethane resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, polyamide resin, nylon resin, alkyd resin, melamine resin, etc. The undercoat layer may be composed of a single resin selected from these, or may be composed of a mixture of two or more resins. Moreover, a metal compound, carbon, silica, resin powder, etc. can be dispersed in the undercoat layer. Further, various pigments, electron accepting substances, electron donating substances and the like can be contained in the undercoat layer for improving the characteristics.

  As a charge generating agent, the diffraction peak with a Bragg angle (2θ ± 0.2 °) shows a maximum peak at 27.2 ° in the X-ray diffraction spectrum using CuKα as a radiation source, and simultaneously peaks at 28.6 °. And its intensity is less than 20% of the intensity of 27.2 °, and further has a diffraction peak at 7.3 ° as the lowest angled diffraction peak, and is 7.4 ° or more and less than 9.4 ° Oxytitanium phthalocyanine having no diffraction peak in the range is used.

An example of the X-ray diffraction pattern of the oxytitanium phthalocyanine used is shown in FIG.
The oxytitanium phthalocyanine shown in FIG. 1 has a maximum diffraction peak at 27.2 ° as a diffraction peak with a Bragg angle (2θ ± 0.2 °) and a peak at 28.6 ° at the same time. Is less than 20% of the intensity of 27.2 °, and further has a diffraction peak at 7.3 ° as the lowest diffraction peak, and a diffraction peak in the range of 7.4 ° to less than 9.4 °. It does not have.

  The diffraction peaks shown above were measured in a state where oxytitanium phthalocyanine was extracted from the photosensitive layer after the photosensitive layer was formed. By using this specific oxytitanium phthalocyanine, it is possible to provide an electrophotographic photosensitive member having excellent sensitivity in a long wavelength region and exhibiting stable characteristics without being affected by the use environment, particularly humidity.

  Conventionally, X-ray diffraction spectra of oxytitanium phthalocyanine used in electrophotographic photoreceptors include powdered oxytitanium phthalocyanine having a desired crystal form after synthesis, or a resin or dispersion solvent created when forming a photosensitive layer. The sample was measured using a pellet of the coating solution.

  However, even if the X-ray diffraction spectrum of oxytitanium phthalocyanine is measured before the formation of the photosensitive layer, the crystal form of oxytitanium phthalocyanine contained in the photosensitive layer cannot be accurately determined. That is, there are various external factors in forming the photosensitive layer, and the diffraction spectrum may be different before and after the formation of the photosensitive layer.

That is, in a laminated type photoreceptor in which a charge transport layer is laminated on a charge generation layer, a coating solution containing a charge generator is applied and formed on a conductive support, dried if necessary, and then charge transport. In order to form a photosensitive layer by applying a coating liquid containing an agent to form a charge transport layer and drying to fix each layer, the thermal external cause of the drying process, the charge transport layer forming coating liquid There is a possibility that the diffraction spectrum of the charge generating agent undergoes crystal transition due to contact with the solvent used, and the diffraction spectrum in the coating solution state and the diffraction spectrum in the final state of the photoconductor do not necessarily show the same crystal type. There is. Therefore, in order to examine the diffraction spectrum of the charge generating agent actually functioning, it is necessary to take out and measure the charge generating agent after forming the photosensitive layer.
When extracting oxytitanium phthalocyanine from the photosensitive layer, care must be taken not to crystallize the oxytitanium phthalocyanine. Further, the photosensitive layer contains a binder resin, a charge transport agent, and the like, which are obstacles in measuring the X-ray diffraction spectrum. Therefore, it is necessary to appropriately select a solvent that does not change the crystal form of oxytitanium phthalocyanine by removing the binder resin, the charge transport agent, and the like.

  In addition to the specific oxytitanium phthalocyanine used in the present invention, other oxytitanium phthalocyanine, an azo pigment, or the like can be mixed in the photosensitive layer in order to obtain an appropriate photosensitivity wavelength and sensitizing action. . These are desirable in terms of good sensitivity compatibility. Other examples include monoazo pigments, bisazo pigments, trisazo pigments, polyazo pigments, indigo pigments, selenium pigments, toluidine pigments, pyrazoline pigments, perylene pigments, quinacridone pigments, and pyrylium salts.

  The binder resin for forming the photosensitive layer includes polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, chlorinated polyether, vinyl chloride-vinyl acetate. Resin, polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin, polyallylsulfone resin , Silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, EVA (ethylene / vinyl acetate) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene) resin ABS (acrylonitrile butadiene styrene) resin and epoxy arylate such resins.

  They may be used alone or in combination of two or more. It is preferable to use a mixture of resins having different molecular weights because the hardness and wear resistance can be improved.

  In the case where the photosensitive layer has a laminated structure comprising a charge generation layer and a charge transport layer, the resin can be applied to either layer.

  Solvents used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, toluene and xylene. Aromatic hydrocarbons such as dichloromethane, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran (THF), methoxyethanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone , Esters such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, diethyl ether, dimethoxyethane, tetrahydride Furan, dioxolane, dioxane or ether solvents such as anisole,, N, N-dimethylformamide, there are dimethyl sulfoxide and the like. Among these, ketone solvents, ester solvents, ether solvents, or halogenated hydrocarbon solvents (chlorine hydrocarbons) are preferred, and these can be used alone or as a mixture of two or more.

  The amount of the binder resin is 10 to 500 parts by weight, preferably 25 to 300 parts by weight with respect to 100 parts by weight of the charge generating agent.

  The electrophotographic photoreceptor of the present invention contains a compound represented by the following general formula (I) as a charge transport agent.

In the general formula (I), R _{1 to} R ₄ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. Represents.

  The charge transfer agent represented by the above general formula (I) has good compatibility with the above-mentioned specific oxytitanium phthalocyanine and can provide a highly durable electrophotographic photosensitive member.

  Among the compounds represented by the general formula (I), the compounds represented by the following chemical formulas (Ia) to (Ie) are particularly preferable because of their good compatibility with the specific oxytitanium phthalocyanine described above.

  Specific compounds are shown below, but the present invention is not limited to them.

  In this case, the content of the compound represented by the general formula (I) in the charge transport layer is preferably 0.3 to 2.0 parts by weight with respect to 1 part by weight of the binder resin. If the content of this compound is less than 0.3 parts by weight, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 2.0 parts by weight, mechanical properties such as wear resistance are deteriorated.

  Furthermore, the compound represented by the general formula (I) and another charge transporting agent can be mixed and used. In this case, the content ratio of the compound represented by the general formula (I) and the other compound is the compound represented by the general formula (I): other compound = 50: 50 to 95: 5, preferably 70:30. A range of ~ 95: 5 is preferred.

  Other charge transport agents include polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl pyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, poly Conductive polymer compounds such as isothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, and polyphthalocyanine can be used. Further, as a low molecular compound, trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone and derivatives thereof, polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, indole, carbazole, Nitrogen-containing heterocyclic compounds such as imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, triphenylmethane, triphenylamine, enamine, stilbene and the like can be used. Further, a polymer solid electrolyte in which a polymer compound such as polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethacrylic acid or the like is doped with a metal ion such as Li ion can also be used. Furthermore, an organic charge transport complex formed of an electron donating compound typified by tetrathiafulvalene-tetracyanoquinodimethane and an electron accepting compound can also be used. Desired photoreceptor characteristics can be obtained by mixing and adding the above compounds.

  In the coating solution for producing the electrophotographic photosensitive member of the present invention, an antioxidant, an ultraviolet absorber, a radical scavenger, a softener, a curing agent, a crosslinking agent, etc. are added as long as the characteristics are not impaired. The characteristics, durability, and mechanical properties of the electrophotographic photosensitive member can be improved. In particular, the use of an antioxidant and an ultraviolet absorber alone or in combination contributes to improving the durability of the electrophotographic photoreceptor, and is useful. Of these, hindered phenolic antioxidants, amine-based antioxidants, sulfur-based antioxidants, and benzotriazole-based ultraviolet absorbers are preferred for the photosensitive layer.

As the hindered phenol antioxidant, amine antioxidant, sulfur antioxidant and benzotriazole ultraviolet absorber added to the photosensitive layer, for example, the following are preferable.
Phenol antioxidants include 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6-tert. -Butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl-propionate-β- (3,5-di-tert-butyl-4-hydroxyphenyl), α-tocopherol, monophenols such as β-tocopherol, n-octadecyl-3- (3′-5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2,2′-methylenebis (6-tert-butyl-4) -Methylphenol), 4.4'-butylidene-bis- (3-methyl-6-tert-butylpheno) 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3 , 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate] Polyphenols such as methane are preferred, and one or more of them can be simultaneously contained in the photosensitive layer.

  For example, amine antioxidants include α, α ′ (tetrabenzyl) diamino-P-xylene, N-phenyl-1-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N, N-diethyl. -P-phenylenediamine, N-phenyl-N'-ethyl-2-methyl-p-phenylenediamine, N-ethyl-N-hydroxyethyl-p-phenylenediamine, alkylated diphenylamine, N, N'-diphenyl-p -Phenylenediamine, N, N'-diallyl-p-phenylenediamine, N-phenyl-1,3-dimethylbutyl-p-phenylenediamine, 4,4'-dioctyl-diphenylamine, 4,4'-dioctyl-diphenylamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2, Examples include 4-trimethyl-1,2-dihydroquinoline, N-phenyl-β-naphthylamine, N, N′-di-2-naphthyl-p-phenylenediamine, and the like. One or more of these can be simultaneously contained in the photosensitive layer.

  Sulfur-based antioxidants include dilauryl-3,3-thiodipropionate, ditridecyl-3,3-thiodipropionate, dimyristyl-3,3-thiodipropionate, distearyl-3,3-thiodipropioate. Lauryl stearyl-3,3-thiopropionate, bis [2-methyl-4- (3-n-alkylC12-C14) thiopropionate) -5-t-butylphenyl] sulfide, pentaerythritol tetra (Β-lauryl-thiopropionate) ester, 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole and the like can be mentioned. One or more of these can be simultaneously contained in the photosensitive layer.

  Ultraviolet absorbers include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5 -Di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5 ' -Tert-octylphenyl) benzotriazoles such as benzotriazole, phenyl salicylate, salicylic acid-p-te Salicylic acid series such as rt-butylphenyl and salicylic acid-p-octylphenyl are preferred, and benzotriazole ultraviolet absorbers are particularly preferred. One or more ultraviolet absorbers can be simultaneously contained in the photosensitive layer.

  The addition amount of the phenolic antioxidant added to the electrophotographic photosensitive member of the present invention is in the range of 1 to 20% by weight with respect to the binder resin, and the addition amount of the amine antioxidant is 1 with respect to the binder resin. In the range of ˜20% by weight, the addition amount of the sulfur-based antioxidant is preferably 0.1 to 5% by weight with respect to the binder resin. On the other hand, the addition amount of the ultraviolet absorber is preferably 1 to 20% by weight with respect to the binder resin.

  In addition, a thin film made of an organic thin film such as polyvinyl formal resin, polycarbonate resin, fluororesin, polyurethane resin, or silicone resin, or a siloxane structure formed from a hydrolyzate of a silane coupling agent is formed on the photosensitive layer. A surface protective layer (protective layer) may be provided as a film. In that case, the durability of the electrophotographic photosensitive member is improved, which is preferable. This surface protective layer may be provided in order to improve functions other than the durability improvement.

<Electrophotographic device>
An electrophotographic apparatus on which the electrophotographic photosensitive member of the present invention is mounted performs image formation by at least a commonly used method such as a charging step, an exposure step, a development step, and a transfer step, and realizes these steps. Have means for.
Specifically, the charging method may be any of a contact type such as a brush or a roller, or a non-contact type such as a scorotron or a corotron, and may be a positive or negative charged charge.
The exposure method may be either LED or LD.
The development method may be two-component, one-component, or magnetic / non-magnetic.
The transfer system may be a roller, a belt, or the like.
As the cleaning method, blade cleaning, brush cleaning, a charging unit or a developing unit may be used as a cleaning process.
Further, a method in which the cleaning process and the charge removal process are omitted may be used.

Next, the electrophotographic apparatus of the present invention will be described. FIG. 2 is a schematic configuration diagram of the electrophotographic apparatus of the present invention.
Reference numeral 11 denotes an electrophotographic photosensitive member rotated in the direction of an arrow in the figure, and a charging member 12 serving as a charging unit is provided in contact with the electrophotographic photosensitive member 11.
The charging member 12 is supplied with a voltage from a power source 13 and uniformly charges the surface of the electrophotographic photosensitive member 11 to a predetermined potential.

  Around the electrophotographic photosensitive member 11, an exposure device 14 as an exposure unit, a developing device 15 as a developing unit, a transfer device 16 as a transfer unit, and a cleaning device are sequentially arranged along the rotation direction of the electrophotographic photosensitive member 11. 17 is arranged. In addition, a fixing device 19 is disposed downstream of the transfer device 16 and the electrophotographic photosensitive member 11 in the conveying direction of the recording medium (recording paper). Note that a static eliminator is not provided.

The exposure device 14 forms an electrostatic latent image by exposing the surface of the electrophotographic photosensitive member 11 uniformly charged by the charging device 12 imagewise.
The electrostatic latent image is carried on the surface of the electrophotographic photosensitive member 11 and moves to a position facing the developing device 15 and is visualized by toner stored in the developing device 15, and the toner image is visualized by the toner. 11 is formed.
This toner image is carried on the surface of the electrophotographic photosensitive member 11 while moving to a position facing the transfer device 16, and is recorded on a recording paper that is a recording medium sandwiched between the electrophotographic photosensitive member 11 and the transfer device 16. Transcribed.
The recording paper having the transferred toner image is conveyed to the fixing device 19, and the toner image is fixed on the recording paper by heat and pressure.
In addition, the electrophotographic photosensitive member 11 after the toner image has been transferred is subjected to a series of electrophotographic image forming processes after the transfer residual toner and the like are removed by the cleaning device 17.
In the case of repeatedly forming an image, an image forming process of an electrophotographic method starting from a charging step by the charging device 12 is performed again.

  At this time, it is preferable that the time required from the start of exposure of the surface of the electrophotographic photoreceptor 11 by the exposure device 14 to the end of the toner image formation by the developing device 15 is 100 milliseconds or less. That is, the electrophotographic photosensitive member on the line connecting the center of the developing roller of the developing device 15 and the center of the electrophotographic photosensitive member 11 in FIG. 2 from the position where the light emitted from the exposure device 14 reaches the electrophotographic photosensitive member 11. The time required for the electrophotographic photosensitive member 11 to rotate to the developing position which is the surface of the body 11 is preferably 100 milliseconds or less. By being 100 milliseconds or less, it becomes difficult to be affected by the dark decay of the photosensitive member, and it becomes possible to develop faithfully with respect to the latent image formed by the exposure device 14. Furthermore, it is possible to cope with an image forming apparatus with higher speed and higher productivity.

  The example shown in FIG. 2 is a mode including a single electrophotographic photosensitive member, a charging unit, a developing unit, and a transfer unit. However, the present invention is not limited to such a mode. Correspondingly, a so-called tandem type color electrophotographic apparatus provided with four each may be used.

The example shown in FIG. 2 is a transfer system in which a toner image is directly transferred from the electrophotographic photoreceptor 11 to a recording medium. However, the present invention is not limited to such a transfer system, and an intermediate transfer using an intermediate transfer body. It may be a method.
In other words, the transfer means for transferring the toner image carried on the electrophotographic photosensitive member to the recording medium may include a primary transfer portion, an intermediate transfer member, and a secondary transfer portion.

The intermediate transfer method will be described in more detail. For example, when the above-described developing unit forms one toner image, the toner image carried on the electrophotographic photosensitive member is conveyed to a position facing the primary transfer unit. Then, the image is primarily transferred to an intermediate transfer member of a well-known and conventional form such as a belt shape. Next, the toner image primarily transferred onto the intermediate transfer member is conveyed to a position facing the secondary transfer portion while being carried on the surface of the intermediate transfer member, and then secondarily transferred onto the recording medium. Here, both the primary transfer portion and the secondary transfer portion can adopt a well-known and commonly used transfer method. For example, a toner image can be transferred by arranging a transfer roller and applying a predetermined transfer bias. it can.
Further, at this time, when the developing means forms four color toner images corresponding to each of YMCK as in the above-described tandem type color electrophotographic apparatus, the predetermined position on the intermediate transfer member. In addition, primary transfer is performed for each color so that toner images of four colors are stacked. Next, the four-color toner images that are primarily transferred and laminated on the intermediate transfer member are conveyed to a position facing the secondary transfer unit while being supported on the surface of the intermediate transfer member, and then are recorded on the recording medium. Secondary transfer is performed at once.

<Process cartridge for electrophotographic apparatus>
An electrophotographic process cartridge comprising one or more means selected from the above-described charging means, exposure means, developing means, cleaning means, and transfer means, and an electrophotographic photosensitive member is provided. It can be attached / removed integrally with the apparatus, and the exchange operation can be simplified.

  Hereinafter, Examples 1 to 9 of the electrophotographic photoreceptor according to the present invention will be described in detail together with Reference Example 1 and Comparative Examples 1 to 4.

(Synthesis example 1 of oxytitanium phthalocyanine)
292 parts of 1,3-diiminoisoindoline and 1800 parts of sulfolane are mixed, and 204 parts of titanium tetrabutoxide are added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 170 ° C. and 180 ° C. After the reaction is completed, the mixture is allowed to cool, and then the precipitate is filtered, washed with acetone until the powder turns blue, then washed several times with methanol, further washed several times with hot water at 80 ° C., and dried. Crude oxytitanium phthalocyanine was obtained.
60 parts of the obtained crude oxytitanium phthalocyanine pigment washed with hot water was stirred and dissolved in 1000 parts of 96% sulfuric acid at 3 to 5 ° C. and filtered. The obtained sulfuric acid solution was added dropwise to 35000 parts of ice water with stirring, the precipitated crystals were filtered, and then washed with water until the washing solution became neutral to obtain an aqueous paste of oxytitanium phthalocyanine pigment.
To this water paste, 1500 parts of tetrahydrofuran was added and stirred at room temperature. When the dark blue color of the paste changed to light blue, the stirring was stopped and immediately filtered under reduced pressure. The crystals obtained on the filter were washed with tetrahydrofuran to obtain 98 parts of a pigment wet cake. This was dried under reduced pressure (5 mmHg) at 70 ° C. for 2 days to obtain 78 parts of oxytitanium phthalocyanine crystal.

Example 1
As a conductive support, on a cylindrical drum made of aluminum with a diameter of 30 mm, an alkyd resin (Beckolite M-6401-50 manufactured by Dainippon Ink and Chemicals) and an amino resin (Super Becamine G-821-60 Dainippon Ink) (Chemical Industry Co., Ltd.) was mixed at a weight ratio of 65:35 to prepare a mixed resin. Further, the mixed resin and titanium oxide (CR-EL Ishihara Sangyo Co., Ltd.) were mixed at a weight ratio of 1: 3 and dissolved in methyl ethyl ketone to form an undercoat layer having a thickness of 1.5 μm as a coating solution.

  Next, 10 g of the oxytitanium phthalocyanine powder obtained in Synthesis Example 1 is added to a solution obtained by dissolving 10 g of polyvinyl butyral resin (BH-1 Sekisui Chemical Co., Ltd.) in 500 ml of glass beads and methyl ethyl ketone, and 20 hours in a sand mill disperser. After dispersion, the obtained dispersion was filtered to remove the glass beads, and a charge generation layer coating solution was prepared. This was dip-coated on the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm.

  Next, a polycarbonate resin (Panlite TS2050 manufactured by Teijin Chemicals Ltd.) as a binder resin, a compound represented by the chemical formula (Ia) (described in paragraph [0064]), and a phenolic antioxidant as a charge transport agent 2.6-di-t-4 methylphenol was prepared at a weight ratio of 1.0: 1.0: 0.05 and dissolved in tetrahydrofuran to prepare a charge transport layer coating solution. The electroconductive support having the charge generation layer formed thereon is dip-coated in the charge transport layer coating solution and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 25.0 μm. Produced.

Preparation of specimen for X-ray diffraction Incision is made on the surface of the electrophotographic photosensitive member obtained in Example 1 in the circumferential direction and the cylindrical axis direction intersecting with the office cutter to form a cut having a side of about 2 cm. . The photosensitive film is peeled off using tweezers from the cut portion. Place 15 ml of 4-methoxy-4-methylpentanone in a 50 ml beaker, immerse the peeled photosensitive film in it, completely dissolve the charge transport layer, and stir well to disperse it in a solvent as gel-like fine pieces Let This is suction filtered with a membrane filter (Pore size 0.2 μm) made of Teflon (registered trademark), and the filtrate is washed with 10 ml of PTX. Next, the membrane filter is closely attached to the silicon non-reflective plate so that the filtrate is inside, and only the membrane filter is peeled off to attach oxytitanium phthalocyanine to the silicon non-reflective plate. did.

X-Ray Diffraction When measuring the specimen sample prepared as described above, measurement is performed by a powder method, CuKα (wavelength 1.54178Å) is used as an X-ray source, and the measurement conditions are as follows.

〔Measurement condition〕
X-ray diffractometer X'Pert manufactured by Flipx Corporation
Measurement conditions X-ray tube Cu
Scanning range 4 ° to 35 °
Tube voltage 45kv
Tube current 40mA
Step angle 0.01 degree
Counting time 20 seconds
Receiving slit, divergent slit, variable type
Irradiation width 20mm

  The X-ray diffraction pattern of the specimen sample is shown in FIG. According to FIG. 1, oxytitanium phthalocyanine extracted from the photosensitive layer has a maximum peak at a Bragg angle (2θ ± 0.2 °) of 27.2 °, and a peak at 28.6 ° at the same time. Its intensity is less than 20% of the intensity of 27.2 °, and further has a diffraction peak at 7.3 ° as the lowest angled diffraction peak, and diffracts in the range of 7.4 ° or more and less than 9.4 °. It did not have a peak.

(Example 2)
An electrophotographic photoreceptor in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (Ib) (described in paragraph [0065]) was used instead of the charge transfer agent used in Example 1. Was made.

(Example 3)
An electrophotographic photoreceptor in the same manner as in Example 1 except that instead of the charge transfer agent used in Example 1, the charge transfer agent represented by the chemical formula (Ic) (described in paragraph [0066]) was used. Was made.

Example 4
An electrophotographic photoreceptor in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (Id) (described in paragraph [0067]) was used instead of the charge transfer agent used in Example 1. Was made.

(Example 5)
An electrophotographic photoreceptor in the same manner as in Example 1 except that instead of the charge transfer agent used in Example 1, the charge transfer agent represented by the chemical formula (Ie) (described in paragraph [0068]) was used. Was made.

(Example 6)
Instead of the phenolic antioxidant 2.6-di-tert-butyl-4-methylphenol used in Example 1, the sulfur-based antioxidant distearyl 3,3′thiodipropionate (Semilyzer TPS Electrophotographic photosensitive member in the same manner as in Example 1 except that the ratio (weight ratio) of binder resin: charge transport agent: sulfuric antioxidant was changed to 1: 1: 0.01. Was made.

(Example 7)
Instead of the phenolic antioxidant 2.6-di-tert-butyl-4-methylphenol used in Example 1, the ultraviolet absorber 2- (2-hydroxy-5-methylphenyl) benzotriazole (Tinuvin) -P Geigy) was used to produce an electrophotographic photoreceptor in the same manner as in Example 1.

(Example 8)
Instead of the phenolic antioxidant 2.6-di-tert-butyl-4-methylphenol used in Example 1, an amine antioxidant α, α ′-(tetrabenzyl) diamino-P-xylene Otherwise, an electrophotographic photosensitive member was produced in the same manner as in Example 1.

Example 9
In addition to the composition of the charge transport layer used in Example 1, the sulfur-based antioxidant distearyl 3,3′thiodipropionate and the ultraviolet absorber 2- (2-hydroxy-5-methylphenyl) benzotriazole In addition, the ratio (weight ratio) of binder resin: charge transport agent: phenolic antioxidant: sulfuric antioxidant: UV absorber is 1: 1: 0.05: 0.01: 0.05. A photoconductor was prepared.

(Reference Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the phenolic antioxidant used in Example 1 was not added.

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that α-type oxytitanium phthalocyanine represented in FIG. 3 was used instead of the charge generating agent used in Example 1.

(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that a charge transporting agent represented by the following chemical formula (A) was used instead of the charge transporting agent used in Example 1.

(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that a charge transporting agent represented by the following chemical formula (B) was used instead of the charge transporting agent used in Example 1.

(Comparative Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that a charge transporting agent represented by the following chemical formula (C) was used instead of the charge transporting agent used in Example 1.

(Electrophotographic photoreceptor evaluation)
Using an electrophotographic photosensitive member evaluation apparatus (manufactured by Yamanashi Electronics Co., Ltd.), the electrophotographic photosensitive member produced in Examples 1 to 9, Comparative Examples 1 to 4, and Reference Example 1 has an environment of a temperature of 23 ° C. and a humidity of 50%. Below (N / N), the surface potential (V0) of the electrophotographic photosensitive member when a discharge current of 25 μA is applied to the electrophotographic photosensitive member by the scorotron method is measured. Thereafter, the discharge current is adjusted so that the surface potential becomes −700 V, and the exposure energy amount when the surface potential is attenuated to ½ (−350 V) by irradiation with a semiconductor laser having a wavelength of 780 nm: half exposure energy amount (E1 / 2) was measured. Further, the surface potential of the electrophotographic photosensitive member when irradiated with an exposure energy of 1.0 μJ / cm ² is defined as a residual potential (VL), and the results are shown in Table 1. The measurement was performed at a development-exposure interval of 100 ms. Here, the potential measurement position coincides with the development position in the electrophotographic apparatus. For example, in the case of an electrophotographic apparatus as shown in FIG. 2, the center of the electrophotographic photoreceptor 11 and the developing roller of the developing apparatus 15 are provided. The surface of the electrophotographic photosensitive member 11 on the line connecting the center is the development position.

Here, when the upper limit of VL is about 100 V and half exposure is 0.13 (μJ / cm ² ) or more, the image density decreases. When the Vo drop is Δ50V or more, image noise occurs.

As can be seen from Table 1, Examples 1 to 9 are based on the combination of the specific charge generating agent and the specific charge transport agent in the present invention. The potential did not change greatly, and the photoreceptor characteristics were good.
On the other hand, Reference Example 1 was reduced by Vo, Comparative Example 1 was reduced by half-exposure, and Comparative Examples 2 and 3 were a combination of a specific charge generating agent and another charge transport agent in the present invention after 10,000 cycles. Vo or the residual potential changed greatly, and the characteristics of the photoreceptor were not satisfactory.

(Light response)
Using an electrophotographic photoreceptor evaluation apparatus (manufactured by Yamanashi Electronics Co., Ltd.), the amount of light which is 5 times the half exposure amount with respect to the electrophotographic photoreceptors produced in Examples 1 to 9 and Comparative Examples 1 to 4 and Reference Example 1. The surface potential at the development position when the time from exposure to arrival at the development position was changed to 100 ms, 50 ms, and 30 ms was evaluated as photoresponsiveness (-V), and the results are shown in Table 1. It is shown in 2.

  As can be seen from Table 2, Examples 1 to 9 had excellent photoreceptor characteristics with a low surface potential regardless of whether the time until reaching the developer position after exposure was long or short. On the other hand, in Comparative Examples 1 to 3, when the arrival time is shortened, the surface potential is remarkably increased, and the photoreceptor characteristics are not satisfactory.

(Image evaluation)
The image was confirmed by changing the transfer current using a Ricoh CX-411 color printer. A solid black image was printed in the first cycle, and the afterimage (ghost) appearing on the subsequent halftone was evaluated in an environment of 23 ° C. and 50% RH. However, the erase exposure equipment equipped in the process was excluded and evaluated. The results are shown in Table 3. Note that no afterimage generation was indicated by ○, afterimage generation was indicated by Δ, and strong afterimage generation was indicated by ×.

  As is apparent from Table 3, Examples 1 to 9 were photoreceptors having good afterimages. On the other hand, in Reference Example 1, a slight afterimage was generated in a strong transfer current, and in Comparative Examples 2 to 4, an afterimage was generated and the photoreceptor characteristics were not satisfactory.

  Summarizing the above evaluation results, by combining the specific charge transfer agent and charge generator in the present invention, it is possible to provide an electrophotographic photoreceptor excellent in durability, capable of high-speed correspondence and excellent in image noise. In other words, according to the present invention, it can be seen that an electrophotographic photoreceptor having excellent electrophotographic characteristics can be obtained without showing an afterimage even when used in an erase-less electrophotographic apparatus with a very low residual potential. It was.

11 Electrophotographic photosensitive member 12 Charging member 13 Power source 14 Exposure device 15 Developing device 16 Transfer device 17 Cleaning device 19 Fixing device

JP-A-3-75660 Japanese Patent Laid-Open No. 5-6011 JP 11-149170 A JP 2004-279939 A

Claims (13)

An electrophotographic photoreceptor having a conductive support and a photosensitive layer provided on the conductive support,
The photosensitive layer includes a binder resin, a charge generator, and a charge transport agent,
The charge generating agent contains oxytitanium phthalocyanine,
The oxytitanium phthalocyanine has a maximum peak at 27.2 ° as a diffraction peak with a Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum using CuKα as a radiation source, and as much as 28.6 °. At the same time, it has a peak, the intensity is less than 20% of the intensity of 27.2 °, and further has a diffraction peak at 7.3 ° as the diffraction peak on the lowest angle side, 7.4 ° to 9.4 ° No diffraction peak in the range of less than
The electrophotographic photoreceptor, wherein the charge transfer agent contains a compound represented by the following general formula (I).

(In the general formula (I), R _{1 to} R ₄ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, or an alkoxy having 1 to 6 carbon atoms. Represents a group.) The electrophotographic photoreceptor according to claim 1, wherein the charge transfer agent contains a compound represented by the following chemical formula (Ia).

The electrophotographic photoreceptor according to claim 1, wherein the charge transfer agent contains a compound represented by the following chemical formula (Ib).

The electrophotographic photoreceptor according to claim 1, wherein the charge transport agent contains a compound represented by the following chemical formula (Ic).

The electrophotographic photoreceptor according to claim 1, wherein the charge transfer agent contains a compound represented by the following chemical formula (Id).

The electrophotographic photoreceptor according to claim 1, wherein the charge transfer agent contains a compound represented by the following chemical formula (Ie).

  The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains a phenol-based antioxidant.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains an amine-based antioxidant.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains a sulfur-based antioxidant.   The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains a benzotriazole-based ultraviolet absorber. The electrophotographic photosensitive member according to any one of claims 1 to 10,
Charging means for charging the surface of the electrophotographic photosensitive member;
Exposure means for forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for visualizing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image onto a recording medium,
An electrophotographic apparatus characterized by having no static eliminating means for neutralizing the electrophotographic photosensitive member. A charging step for charging the electrophotographic photosensitive member;
An exposure step of forming an electrostatic latent image on the surface of the charged electrophotographic photosensitive member;
A developing step of visualizing the electrostatic latent image with toner to form a toner image;
A transfer step of transferring the toner image onto a recording medium,
The electrophotographic photoreceptor is the electrophotographic photoreceptor according to any one of claims 1 to 10,
An electrophotographic method, wherein a time required from the exposure step to the development step is 100 milliseconds or less. One or more means selected from charging means, exposure means, developing means, cleaning means, and transfer means;
A process cartridge for an electrophotographic apparatus, comprising: the electrophotographic photosensitive member according to claim 1.

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