A single-layer photosensitive layer of an electrophotographic photosensitive member contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The charge generating material is a phthalocyanine pigment. A content percentage of the phthalocyanine pigment relative to the mass of the photosensitive layer is at least 0.70% by mass and no greater than 1.40% by mass. A film thickness of the photosensitive layer is at least 25 m and no greater than 32 m. A charge amount difference Q is no greater than 6.50 C.

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 (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer (3) is a single-layer photosensitive layer (3c) containing a charge generating material and an electron transport material. The electron transport material includes a compound represented by general formula (1) shown below. An amount of charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer (3) is at least +7.0 C/g. In general formula (1), R.sup.1 and R.sup.2 each represent, independently of each other, a halogen atom, for example. Further, m, n, and Y are as described in the description. ##STR00001##

Provided is an electrophotographic photosensitive member that can achieve both of abrasion resistance and the suppression of a ghost. The electrophotographic photosensitive member includes: a support; an undercoat layer; a charge-generating layer; and a charge-transporting layer, the undercoat layer, the charge-generating layer, and the charge-transporting layer being arranged in the stated order on the support, wherein the charge-transporting layer includes a charge-transporting substance, and a polymer containing a structure represented by the following general formula (1) and a structure represented by the following general formula (2), wherein the charge-generating layer includes a phthalocyanine crystal and a binder resin, and wherein the undercoat layer includes strontium titanate particles and a binder resin.

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The present disclosure provides an electrophotographic photosensitive member that can suppress a black spot and an exposure memory. The electrophotographic photosensitive member has a support, an undercoat layer and a photosensitive layer having a mono-layer structure in this order, wherein the undercoat layer contains a binder resin and strontium titanate particles; and the photosensitive layer having a mono-layer structure contains a binder resin, a charge generation material, a hole transport material and an electron transport material.

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##

A compound mixture contains a mixture of a compound represented by general formula (1) and a compound represented by general formula (2). In the general formula (1), R.sup.1A, R.sup.2A, R.sup.3A, R.sup.4A, R.sup.5A, R.sup.6A, R.sup.7A, R.sup.8A, R.sup.9A, and R.sup.10A each represent, independently of one another, a hydrogen atom, an alkyl group having a carbon number of at least 1 and no greater than 8, an alkoxy group having a carbon number of at least 1 and no greater than 8, or an aryl group having a carbon number of at least 6 and no greater than 14. Y represents a bivalent group represented by chemical formula (Y1), chemical formula (Y2), or general formula (Y3):

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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.

An electrophotographic photoreceptor includes a conductive substrate, a charge-generating layer disposed on the conductive substrate, and a charge-transporting layer as an outermost layer disposed on the charge-generating layer and containing a binder resin and a charge-transporting material, wherein the average particle size of the crystal of the charge-transporting material is approximately from 0.1 m to 5.0 m.