An electrophotographic photosensitive member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains at least a charge generating material and a compound represented by general formula (1). In general formula (1), R.sup.1 represents an aryl group having a carbon number of at least 6 and no greater than 22 and optionally having an alkyl group having a carbon number of at least 1 and no greater than 10, an alkyl group having a carbon number of at least 3 and no greater than 20, an aralkyl group having a carbon number of at least 7 and no greater than 20, a cycloalkyl group having a carbon number of at least 3 and no greater than 20, or an alkoxy group having a carbon number of at least 1 and no greater than 6. Chemical groups R.sup.2 each represent a halogen atom.

##STR00001##

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 includes a charge generating layer and a charge transport layer. The charge generating layer contains a charge generating material. The charge transport layer contains a hole transport material and a binder resin. The charge transport layer further contains an electron acceptor compound. The hole transport material includes a compound represented by general formula (1). In general formula (1), R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 each represent, independently of one another, a hydrogen atom or a methyl group.

##STR00001##

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 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##

The present invention provides an electrophotographic photosensitive member in which a photosensitive layer has strong close adhesiveness even when used repeatedly, and a positive ghost is reduced. An undercoat layer of the electrophotographic photosensitive member contains a cured product of an electron transport material having a polymerizable functional group; a polyolefin resin having at least one group/structure selected from the group consisting of a carboxyl group, an alkoxycarbonyl group and an anhydrous carboxylic acid structure, and a substituted or unsubstituted phenyl group; and an isocyanate compound having two or more isocyanate groups.

An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer arranged on the conductive substrate and containing, as a charge generating material, any one material selected from the group consisting of titanyl phthalocyanines, metal-free phthalocyanines, chlorogallium phthalocyanines and hydroxygallium phthalocyanines; and, as an electron transporting material, a naphthalene tetracarboxylic acid diimide compound represented by Formula (1) below, where R.sup.1 and R.sup.2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkylene group, an alkoxy group, an alkyl ester group, a phenyl group optionally having a substituent, a naphthyl group optionally having a substituent, or a halogen element; and R.sup.1 and R.sup.2 are optionally the same or different:

##STR00001##

The photoreceptor realizes a stable print density even in a low-temperature environment by suppressing a reduction in print density that is caused by potential fluctuation of the photoreceptor in the low-temperature environment.

A positively chargeable single-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and an electron accepting compound. The hole transport material includes a benzidine derivative. The electron transport material includes at least one compound selected from the group consisting of compounds represented by general formulae (1), (2), (3), and (4) shown below. The electron accepting compound includes at least one compound selected from the group consisting of compounds represented by general formulae (5) and (6) shown below. ##STR00001##

An image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate, an undercoat layer provided on the conductive substrate, containing a binder resin and an electron transport material, and satisfying Expression 1-1, and a photosensitive layer provided on the undercoat layer, a charging device that charges a surface of the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the electrophotographic photoreceptor, a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image, and a transfer device that transfers the toner image to a surface of a recording medium, in which a moving time of an outer peripheral surface of the electrophotographic photoreceptor, required from charging performed by the charging device to development performed by the developing device, is 90 msec or longer, Expression 1-1: 0.20E.sub.F1E.sub.LUMO10.60 (in Expression 1-1, E.sub.F1 represents a Fermi level of the undercoat layer, and E.sub.LUMO1 represents an energy level of LUMO of the undercoat layer).

An image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate, an undercoat layer provided on the conductive substrate, containing a binder resin and an electron transport material, and satisfying Expression 1-1, and a photosensitive layer provided on the undercoat layer, a charging device that charges a surface of the electrophotographic photoreceptor, an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the electrophotographic photoreceptor, a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image, and a transfer device that transfers the toner image to a surface of a recording medium, in which a moving time of an outer peripheral surface of the electrophotographic photoreceptor, required from charging performed by the charging device to development performed by the developing device, is 90 msec or longer,

0.20E.sub.F1E.sub.LUMO10.60Expression 1-1:

(in Expression 1-1, E.sub.F1 represents a Fermi level of the undercoat layer, and E.sub.LUMO1 represents an energy level of LUMO of the undercoat layer).