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).

The present invention relates to an electrophotographic photoreceptor which is a positive charging type electrophotographic photoreceptor comprising a conductive support and a photosensitive layer on the conductive support, wherein the photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin in the same layer, and a residual potential VL.sub.1 at a point at which an exposure amount for forming a latent image is 0.3 ?J/cm.sup.2 is equal to or lower than 130 V when an initial surface potential V0 is set to +700 V, exposure with monochromatic light of 780 nm is performed and measurement is performed by a dynamic method.

The invention relates to an electrophotographic photoreceptor which is excellent in abrasion resistance and electrical properties by using a fluororesin and a polymer containing a structure represented by a specific formula, and has a long life span, an electrophotographic photoreceptor cartridge and an image forming apparatus including the electrophotographic photoreceptor, and a dispersant which is excellent in dispersibility of a fluororesin particle, and the electrical properties, and the compatibility with a binder resin.

An electrophotographic photosensitive member includes an electroconductive support member and a photosensitive layer. The uppermost layer of the electrophotographic photosensitive member defines a surface layer, and the surface layer contains polytetrafluoroethylene particles, a charge transporting material, and polyvinyl acetal. The proportion of the polyvinyl acetal content to the polytetrafluoroethylene particles content in the surface layer is in the range of 0.1% by mass to 15.0% by mass, and the charge transporting material content in the surface layer is 35% by mass or more relative to the total mass of the surface layer.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.

The present invention relates to an electrophotographic photosensitive member in which a surface layer contains a polymer of a hole transport material having a polymerizable functional group, and the hole transport material has a specific fluorene structure.

An electrophotographic photosensitive member includes, in this order, a support, a charge generating layer having a thickness of more than 200 nm and containing a hydroxygallium phthalocyanine pigment or a chlorogallium phthalocyanine pigment as a charge generating material, and a charge transport layer containing a charge transporting material. The charge generating material satisfies a requirement for a specific parameter.

A metallic ingot for impact pressing includes a contact surface of the metallic ingot to contact a male mold in impact pressing having a maximum height roughness Rz of 20 m to 50 m and an average length of a roughness curve element RSm of 150 m to 400 m, the male mold being to be used in combination with a female mold in the impact pressing.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate, wherein when time that takes for a current value to reach the maximum after beginning of application of a square wave voltage to the electrophotographic photoreceptor is T.sub.1 and time that takes for the current value to reach the maximum after the beginning of the application of the square wave voltage and then decrease to one fifth of the maximum is T.sub.2, T.sub.2 is approximately from 3.2 to 11.0 times as large as T.sub.1.

Provided is an electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a surface protective layer disposed in sequence. The surface protective layer includes a cured product of a composition containing a polymerizable compound, a charge transporting material, and at least two polymerization initiators. The polymerization initiators include an acyl phosphine oxide and an O-acyl oxime.