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 μJ/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.

A photoconductor includes an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide particle and a binder resin, and satisfies the following relations (1) and (2):
Smr=Scut/Sk  (1)
0.4≦Smr≦0.6  (2)
where Smr represents an areal ratio of concave parts; Sk represents a reference area; and a Scut represents a cross-sectional area obtained by cutting a three-dimensional curved surface obtained from the reference area with an average height surface, the average height surface being a surface constituted of averaged height of all measured height data.

An electrophotographic photosensitive member comprises a support, an undercoat layer, a charge generation layer and a hole transporting layer disposed in this order. The undercoat layer contains silica particles and a polymer of a composition including an electron transporting material having a polar group selected from the group consisting of a hydroxy group, a thiol group, an amino group, a carboxy group and a methoxy group, and a cross-linking agent. The content of the electron transporting material in the composition is 30 to 70 mass % relative to the total mass of the composition and the content of the silica particles in the undercoat layer is 1 to 30 mass % relative to the total mass of the electron transporting material.

Provided is an electrophotographic photosensitive member including a support, an undercoat layer, and a photosensitive layer in this order, in which: the undercoat layer does not contain a metal oxide, or contains the metal oxide but the content of the metal oxide in the undercoat layer is 10 mass % or less; and the undercoat layer contains a polymerized product of a composition containing at least one kind of anthraquinone derivative selected from the group consisting of a compound represented by the formula (1) and a compound represented by the formula (2). ##STR00001##

An undercoat layer of an electrophotographic photosensitive member includes a binder resin, and a complex particle composed of a core particle coated with tin oxide doped with zinc.

A compound has a structure represented by the following formula (C1): ##STR00001##
wherein R.sub.a1, R.sub.a2, R.sub.a3, R.sub.a41, R.sub.a42, R.sub.a43, R.sub.a44, R.sub.a45, R.sub.a5, R.sub.a6, R.sub.a7, R.sub.a8, R.sub.a9, R.sub.a10, and R.sub.a11 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aralkyl group, an aryl group, a cyano group, a halogen atom, or a group obtained by combining two or more of the above groups, and a combination of R.sub.a1 and R.sub.a2, R.sub.a41 and R.sub.a42, R.sub.a42 and R.sub.a43, R.sub.a43 and R.sub.a44, R.sub.a44 and R.sub.a45, R.sub.a5 and R.sub.a6, R.sub.a8 and R.sub.a9, or R.sub.a10 and R.sub.a11 each independently may form a ring.

A support, a conductive layer, and an intermediate layer of an electrophotographic photosensitive member have a particular surface profile. The intermediate layer is a cured film containing particles.

An electrophotographic photosensitive member includes a support member, an undercoat layer, and a photosensitive layer adjacent to the undercoat layer in this order, wherein the undercoat layer contains a polymerized product of a composition including an electron transporting material having a polymerizable functional group, a cross-linking agent, and a thermoplastic resin having a polymerizable functional group, and at least one type of particles selected from the group consisting of resin particles having a hollow structure and rubber particles, wherein a content of the electron transporting material in the undercoat layer is 30% by mass or more with respect to a total mass of the composition, and wherein a content of the at least one type of particles in the undercoat layer is 10% by mass or more and 100% by mass or less with respect to the content of the electron transporting material.

A photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, the undercoat layer being disposed over the conductive support, the photoconductive layer being disposed over the undercoat layer, wherein the undercoat layer includes zinc oxide particles, wherein when a film thickness of the undercoat layer is 20 μm, the undercoat layer has transmittance of 50% or more to light having a wavelength in a range of 500 nm or more but 800 nm or less, wherein a lowest transmittance of light is 85% or less in the range, and wherein when an electric field of 5 V/μm is applied to the undercoat layer, volume resistivity of the undercoat layer is 1.0×10.sup.7 Ω.Math.cm or more but 5.0×10.sup.8 Ω.Math.cm or less at an environment of 23° C. and 55% RH.

An electrophotographic photosensitive member includes a laminated body, the laminated body including a support, an undercoat layer, and a charge generating layer. The undercoat layer includes a polymerized product of a composition including an electron transport material represented by formula (1), a cross-linking agent, and a thermoplastic resin having a polymerizable functional group, the laminated body satisfying expressions (2) and (3)
Z.sup.1—X—Z.sup.2  (1)
0.20≦|Vd2−Vd1|≦2.0  (2)
τ≦10  (3)
in which Z.sup.1 and Z.sup.2 are groups having electron transport property, X is a linker, Vd2 and Vd1 are surface potentials of the charge generating layer after charging and τ is transit time based on a change rate of the surface of the charge generating layer, each as defined in the specification.