Provided is a process cartridge having a charging member and an electrophotographic photosensitive member to be charged by being in contact with the charging member, wherein the electrophotographic photosensitive member has a support and a photosensitive layer in this order, and a surface layer of the electrophotographic photosensitive member has a Martens hardness of 230 N/mm.sup.2 or less.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer having a single-layer structure. The photosensitive layer contains a charge generating material, an electron transport material, a polycarbonate resin, and a hole transport material. The electron transport material includes a compound having a halogen atom and represented by general formula (1), (2), (3), (4), or (5). The polycarbonate resin has a terminal group having a fluoro group and represented by general formula (10). The hole transport material includes a compound represented by general formula (20), (21), (22), (23), (24), (25), (26), or (27). A charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer is at least +6.5 C/g. The photosensitive layer has a Vickers hardness of at least 17.0 HV at 45 C. ##STR00001## ##STR00002## ##STR00003##

An electrophotographic photoreceptor that includes a conductive support; and at least a charge generation layer and a charge transport layer on the conductive support, where the charge transport layer includes at least two layers of a first charge transport layer which is an outermost layer and a second charge transport layer which is in contact with the first charge transport layer, such that the elastic deformation ratio of a binder resin A contained in the first charge transport layer is T1(%) and the elastic deformation ratio of a binder resin B contained in the second charge transport layer is T2(%) such that T1 and T2 satisfy a relationship of {0(T1T2)4}, the first charge transport layer contains a charge transport material having a molecular weight of 600 or more, and the binder resin A and the binder resin B have different monomer units from each other.

An electrophotographic photosensitive member includes a photosensitive layer of a single layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. An optical response time is 0.05 milliseconds or longer and 0.85 milliseconds or shorter. The optical response time is a time from irradiation of a surface of the photosensitive layer charged to +800 V with pulse light having a wavelength of 780 nm to decay of a surface potential of the photosensitive layer from +800 V to +400 V. The pulse light has an intensity that allows the surface potential of the photosensitive layer to decay to +200 V from +800 V after 400 milliseconds elapse from the irradiation of the surface of the photosensitive layer charged to +800 V with the pulse light. The photosensitive layer has a Martens hardness at 50 C. of at least 160 N/mm.sup.2.

The present invention provides an electrophotographic photoreceptor including a photosensitive layer containing an electron transport material, and having high pressure resistance and suppressed occurrence of a leak phenomenon, a method for producing the same, and an electrophotographic device using the same. The electrophotographic photoreceptor includes an electrically conductive support containing an aluminum alloy; an anodic oxide film formed on a surface of the electrically conductive support; and a photosensitive layer formed on the anodic oxide film. The photosensitive layer contains an electron transport material having an electron mobility of 10.sup.7 cm.sup.2/V/sec or more when field intensity is set to 20 V/m. The surface of the electrically conductive support having the anodic oxide film formed thereon has an admittance value that is 25 S or more and 60 S or less.

The object of the present invention is to provide a positive charging electrophotographic photoreceptor having high sensitivity, low residual potential, and excellent chargeability, and relates to a positive charging electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a protective layer in this order, the photosensitive layer containing a charge generation substance, a positive hole transport substance, and an electron transport substance in the same layer, in which the positive hole transport substance includes at least one of the compounds represented by any one of the following formulas (1) to (5), and a binder resin of the protective layer is an alcohol-soluble thermoplastic resin, providing that the symbols in the formula are defined in the specification.

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An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer having a single-layer structure. The photosensitive layer contains a charge generating material, an electron transport material, a polycarbonate resin, and a hole transport material. The electron transport material includes a compound having a halogen atom and represented by general formula (1), (2), (3), (4), or (5). The hole transport material includes a compound represented by general formula (20), (21), (22), (23), (24), (25), (26), or (27). A charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer is at least +6.5 C/g. A Vickers hardness of the photosensitive layer at 45 C. is at least 17.0 HV. ##STR00001## ##STR00002## ##STR00003##

An electrophotographic photosensitive member with suppressed potential variation even in the case that a protective layer including a cured material of a composition having a polymerizable functional group is used is provided. An electrophotographic photosensitive member including a support, a charge generation layer, a charge transport layer containing a charge transporting material, and a protective layer, in the order presented, wherein the charge transport layer contains a polycarbonate resin having a structure selected from a group A and a structure selected from a group B, and the protective layer includes a cured material of a composition containing a compound having at least a functional group selected from chain-polymerizable functional groups and sequential polymerizable functional groups.

The present invention aims to provide an electrophotographic photoreceptor including a charge transport layer and being excellent in electrical properties and adhesiveness while exhibiting sufficient abrasion resistance indispensable for prolonging the life, and an electrophotographic photoreceptor cartridge and an image forming apparatus including the electrophotographic photoreceptor, which is an electrophotographic photoreceptor including a charge transport layer including at least two layers, wherein an elastic deformation ratio of a binder resin contained in a first charge transport layer which is an outermost layer and an elastic deformation ratio of a binder resin contained in a second charge transport layer satisfy a predetermined relationship.

An electrophotographic photoreceptor comprising at least a photosensitive layer on a conductive substrate, wherein the photosensitive layer is a laminate having a charge transport layer and a charge generation layer, the charge transport layer contains four or more types of compounds each having a maximum absorption wavelength falling within a wavelength range of from 300 nm to 600 nm in a tetrahydrofuran solution at 25? C., and maximum absorption wavelengths falling within the wavelength range of at least four types of the compounds of said four or more types of the compounds are separated from each other by 10 nm or more.