An electrophotographic photosensitive member includes, in sequence, a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. The conductive layer is a cured film, and the cured film contains titanium oxide particles doped with niobium. The undercoat layer contains a cured product of a composition that contains an electron transport material having a polymerizable functional group and a resin functionalized with a carboxylic acid derivative.

An electrophotographic photoreceptor includes a conductive substrate; a photosensitive layer provided on the conductive substrate; and an undercoating layer that is provided between the conductive substrate and the photosensitive layer and includes a charge transport material containing at least one of imide compounds represented by Formula (1) or (2):

##STR00001## (in Formulas (1) and (2), R.sup.10, R.sup.11, R.sup.20 or R.sup.21 independently represents a group represented by Formula (3) or (4) where X represents a monovalent organic group having at least one of an alkyl group, an alkylene group, an ether group, an ester group, and a keto group, a halogen atom, a nitro group, an aralkyl group, or an aryl group, Y represents a sulfur atom or an oxygen atom, n represents an integer of 0 to 2, and when n represents 2, two X's may be the same or different), and an imide compound is represented by Formula (1A) where Ar represents an aromatic group having 6 to 18 carbon atoms except for a tetravalent perylene group, X.sup.1 and X.sup.2 each independently represent a nitrogen atom or a substituted or unsubstituted carbon atom, Y.sup.1 and Y.sup.2 each independently represent an oxygen atom, a sulfur atom, a selenium atom, or NH, and R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a monovalent organic group:

##STR00002##

An electrophotographic photoreceptor includes a conductive substrate; an undercoat layer on the conductive substrate; a charge generating layer on the undercoat layer; a charge transporting layer on the charge generating layer; and an inorganic protective layer on the charge transporting layer. The undercoat layer, the charge transporting layer, and the inorganic protective layer each have a film elastic modulus of 5 GPa or more.

A photoreceptor comprises a conductive substrate. An undercoat layer is disposed on the conductive substrate. The undercoat layer includes modified metal oxide particles and a binder resin, the modified metal oxide particles comprising metal oxide particles having an outer surface and hygroscopic polymers attached to the surface. The hygroscopic polymers are made by linking a hydrophilic polymer group to the metal oxide particles using a dithiofunctionalized phosphonatomethylaryl ligand that acts as the linking group. A photosensitive layer is disposed on the undercoat layer.

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.

To provide an electrophotographic photosensitive member which does not cause film exfoliation in long-term use. An electrophotographic photosensitive member, having: a support; a layered photosensitive layer; and a protective layer in this order, wherein the protective layer is a single layer, the protective layer includes: at least two specific structures, the two specific structures are included in the protective layer at a mass ratio of 20% or more and 240% or less, and a peak area based on in-plane deformation vibration of terminal olefin (CH.sub.2) of the protective layer and a peak area based on stretching vibration of CO of acryloyloxy groups, the peak areas being determined by total reflection Fourier transform infrared spectroscopy under conditions where an internal reflection element is Ge, and an incidence angle is 45, have a fixed relationship.

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer disposed on the conductive substrate, having a volume resistivity of 5.0?10.sup.7 [?m] or more and 5.0?10.sup.9 [?m] or less, and having a thickness of 20 ?m or more and 40 ?m or less, a charge generation layer disposed on the undercoat layer, and a charge transport layer disposed on the charge generation layer, having a volume resistivity of 1.0?10.sup.13 [?m] or more and 5.0?10.sup.14 [?m] or less, and having a thickness of 15 ?m or more and 40 ?m or less.

Provided is an electrophotographic photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, wherein the undercoat layer and the photoconductive layer are provided over the conductive support in the order of reciting, wherein the undercoat layer contains at least metal oxide particles, a binder, and a salicylic acid derivative such as 4-methylsalicylic acid, wherein the metal oxide particles have a volume resistivity of 110.sup.5 .Math.cm or higher but 110.sup.8 .Math.cm or lower, wherein the undercoat layer has a volume resistivity of 0.00110.sup.6 .Math.cm or higher but 0.0210.sup.6 .Math.cm or lower, and wherein the undercoat layer has a thickness of 2 micrometers or greater but 20 micrometers or less.

An electrophotographic photosensitive member includes a support member, an electroconductive layer, and a photosensitive layer, in this order. The electroconductive layer contains a binder resin, electrically conductive first metal oxide particles, and second metal oxide particles. The refractive index Rb of the binder resin, the refractive index Rc of the first metal oxide particles, and the refractive index Rh of the second metal oxide particles satisfy the relationships: |RbRc|0.35 and |RbRh|0.65. The electroconductive layer has a volume resistivity of 1.010.sup.6 .Math.cm to 1.010.sup.13 .Math.cm, and the ratio of the specific gravity of the first metal oxide particles to the specific gravity of the second metal oxide particles is 0.85 to 1.20.

An electrophotographic apparatus includes an electrophotographic photosensitive member, a charging roller disposed so as to come into contact with the electrophotographic photosensitive member, and a charging device operable to apply only a DC voltage to charge the electrophotographic photosensitive member. The electrophotographic photosensitive member includes a support member, an undercoat layer over the support member, and a photosensitive layer over the undercoat layer and having a plurality of discrete recesses in the surface thereof. The undercoat layer contains zinc oxide particles and a binder resin. The undercoat layer has cavities therein, and the cavities account for 5.00% or less of the volume of the undercoat layer.