An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer on the conductive substrate, and a photosensitive layer on the undercoat layer. The undercoat layer contains at least one perinone compound selected from the group consisting of a compound represented by general formula (1) below and a compound represented by general formula (2) below, an amine compound (A) having an ionization potential of 5.4 eV or more and 5.9 eV or less, and a binder resin, ##STR00001##
where: in general formula (1), R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.16, R.sup.17, and R.sup.18 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom; R.sup.11 and R.sup.12 may be bonded to each other to form a ring, so may R.sup.12 and R.sup.13, and so may R.sup.13 and R.sup.14; and R.sup.15 and R.sup.16 may be bonded to each other to form a ring, so may R.sup.16 and R.sup.17, and so may R.sup.17 and R.sup.18, and in general formula (2), R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.26, R.sup.27, and R.sup.28 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom; R.sup.21 and R.sup.22 may be bonded to each other to form a ring, so may R.sup.22 and R.sup.23, and so may R.sup.23 and R.sup.24; and R.sup.25 and R.sup.26 may be bonded to each other to form a ring, so may R.sup.26 and R.sup.27, and so may R.sup.27 and R.sup.28.

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 photoconductor includes, in sequence, a support member; an undercoating layer containing a binder resin and an inorganic particle; and a photosensitive layer, wherein the binder resin of the undercoating layer is an alkyd-melamine resin, and the inorganic particle of the undercoating layer contains a strontium titanate particle.

Provided are an electrophotographic photosensitive member excellent in suppression of the occurrence of a photomemory, and a process cartridge and an electrophotographic apparatus each including the electrophotographic photosensitive member. The electrophotographic photosensitive member includes in this order: an electroconductive support; an undercoat layer; and a photosensitive layer, wherein the undercoat layer contains strontium titanate particles and a binder resin, and the photosensitive layer contains a butanediol adduct of titanyl phthalocyanine.

An electrophotographic photoconductor includes, in sequence, a support, an undercoat layer, a charge generation layer containing a charge generation material and a first binder resin, and a charge transport layer containing a charge transport material and a second binder resin. The charge generation material in the charge generation layer is chlorogallium phthalocyanine having diffraction peaks at Bragg angles (20.2) of 7.4, 16.6, 25.5, and 28.3 in an X-ray diffraction pattern obtained by using Cu K- radiation. The undercoat layer contains strontium titanate particles and a third binder resin.

The electrophotographic photosensitive member includes an undercoat layer and a surface layer on or above a support in this order, in which the undercoat layer contains metal oxide particles and a specific binder resin, the surface layer contains a charge transporting substance, fluororesin particles, and a specific binder resin, an arithmetic average roughness Ra of a surface of the undercoat layer is 0.15 m or less, a refractive index (a) of the metal oxide particles and a refractive index (b) of the binder resin contained in the undercoat layer satisfy a specific relationship, and a refractive index (c) of the binder resin contained in the surface layer and a refractive index (d) of the fluororesin particles satisfy a specific relationship.

An image forming apparatus includes an electrophotographic photoreceptor including a conductive substrate, an undercoat layer containing a binder resin and metal oxide particles, disposed on the conductive substrate, and a photosensitive layer disposed on the undercoat layer; a charging unit that charges a surface of the electrophotographic photoreceptor; an electrostatic latent image-forming unit forming an electrostatic latent image on the charged surface of the electrophotographic photoreceptor; a developing unit developing the electrostatic latent image on the surface of the electrophotographic photoreceptor by using a developer containing a toner to form a toner image; and a transfer unit that transfers the toner image onto a surface of a transfer-receiving member, but not including a charge erasing member that erases charges on the surface of the electrophotographic photoreceptor. The photosensitive layer formed is 3.8% or more and 17% or less to a carbon element abundance determined by X-ray photoelectron spectroscopy.

Described herein is a photoreceptor and a method of making metal oxide particles having hygroscopic polymers attached to a surface of the metal oxide particles. The photoreceptor includes a conductive substrate and an undercoat layer disposed on the conductive substrate. The undercoat layer includes metal oxide particles having hygroscopic polymers attached to a surface of the metal oxide particles. The undercoat layer includes a binder resin. A photosensitive layer is disposed on the undercoat layer.

An electrophotographic photoreceptor includes a conductive substrate having a surface, an undercoat layer disposed on the surface of the conductive substrate, and a photosensitive layer on the undercoat layer. A maximum height waviness of a waviness profile of the surface of the conductive substrate on which the undercoat layer is disposed is 1.4 m or less, and the undercoat layer contains a binder resin and has a thickness non-uniformity of 0.4 m or less.

An electrophotographic photoreceptor includes a conductive substrate, an undercoating layer that is disposed on the conductive substrate, and a photosensitive layer that is disposed on the undercoating layer, in which the undercoating layer contains at least one perinone compound selected from the group consisting of a compound represented by Formula (1) and a compound represented by Formula (2) which are shown below, and polyurethane, contains at least one perinone compound selected from the group consisting of the compounds represented by Formulas (1) and (2), and at least one acceptor compound selected from the group consisting of compounds represented by Formula (3) to (15) which are shown in the specification, or contains a resin obtained by polymerizing a diallyl phthalate compound and a charge transporting material.

##STR00001##