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.

A polyarylate resin is represented by general formula (1) shown below. In general formula (1), R.sup.1 and R.sup.2 each represent, independently of one another, a hydrogen atom or a methyl group. r and s each represent an integer of at least 0 and no greater than 49. t and u each represent an integer of at least 1 and no greater than 50. r+s+t+u=100. r+t=s+u. X and Y each represent, independently of one another, a divalent group represented by chemical formula (1-1), chemical formula (1-2), chemical formula (1-3), or chemical formula (1-4). X and Y are different from one another. ##STR00001##

A photoreceptor for electrophotography includes a photosensitive layer provided on a conductive substrate that contains at least a resin binder, a charge transport material, and an additive. The photoreceptor exhibits high photoresponsivity, stable electrical properties regardless of repeated use thereof, and high durability. The resin binder contains a polycarbonate resin composed of a copolymer having structural units expressed by general formulae (1) and (2) below. The charge transport material contains at least one type of stilbene compound expressed by general formulae (3), (4), and (5) below. The additive contains at least one type of diester compound expressed by general formula (6) below. ##STR00001##

An electrophotographic image forming system forms an electrostatic latent image on at least a photoreceptor, develops an image using an electrostatic charge image developing toner, and removes the toner using a cleaning blade. A tip ridge of the cleaning blade is pressed against a surface of the photoreceptor. The system includes a photosensitive layer of the photoreceptor and a surface protecting layer that is provided on a surface of the photosensitive layer. The surface protecting layer includes a polymerizable monomer having at least two polymerizable groups in a molecule and a polymer of a hole transporting compound having a polymerizable group represented by General formula (1). The tip ridge of the cleaning blade has an edge angle that is obtuse and less than 120? and is pressed against the surface of the photoreceptor at an effective contact angle that is in a range of 8 to 20?. ##STR00001##

A photoconductor including a conductive support, an undercoat layer, a charge-generating layer, and a charge-transporting layer, at least the undercoat layer, the charge-generating layer, and the charge-transporting layer being disposed on the conductive support in an order mentioned, wherein the undercoat layer includes a binder resin and metal oxide particles, and the charge-generating layer includes a binder resin, a titanyl phthalocyanine pigment, and a salicylic acid derivative.

The present invention relates to an electrophotographic photoreceptor comprising: a conductive support; and a photosensitive layer on the conductive support, wherein the photosensitive layer contains a charge transport substance, a binder resin, and a compound which has a molecular weight of equal to or less than 350, and is represented by General Formula (1).

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin contains a polyarylate resin. The polyarylate resin is represented by general formula (1). The hole transport material contains a compound represented by general formula (HTM1), (HTM2), (HTM3), (HTM4), (HTM5), (HTM6), or (HTM7). The photosensitive layer has a scratch resistance depth of no greater than 0.50 m. The photosensitive layer has a Vickers hardness of at least 17.0 HV. ##STR00001## ##STR00002##

The present invention relates to an electrophotographic photoreceptor for positive charging, the photoreceptor comprising: a conductive support; and a single-layer type photosensitive layer disposed on the conductive support, the single-layer type photosensitive layer containing a binder resin, a compound (1) having hole transporting ability, and a compound (2) having electron-transporting ability, wherein the level Ah of a compound having a highest energy level of HOMO in the compound (1), the level BI of a compound having a lowest energy level of LUMO in the compound (2), and an energy level Ch of HOMO of another compound C which has a molecular weight of 500 or less and is contained in the photosensitive layer satisfy specific equations.

Provided is a positively charged electrophotographic photoconductor that provides a stable high-quality image in any environment, a manufacturing method thereof, and an electrophotographic apparatus using the same. The positively charged electrophotographic photoconductor includes an electroconductive support; and a single layer-type photosensitive layer provided on the electroconductive support and including a charge generation material, a hole transport material, an electron transport material and a binder resin. Alternately, the positively charged electrophotographic photoconductor includes an electroconductive support; a charge transport layer provided on the electroconductive support and containing at least a hole transport material and a binder resin; and a charge generation layer provided on the charge transport layer and including at least a charge generation material, a hole transport material, an electron transport material and a binder resin. In either embodiment, the binder resin contains a polycarbonate-based resin and has a water vapor permeability ranging from 5 to 13 g/m.sup.2.Math.day.

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.

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