A quinone derivative is represented by general formula (1). In general formula (1), at least one of R.sup.1-R.sup.3 and at least one of R.sup.4-R.sup.6 each represent, independently of one another, an alkyl group having 4 to 10 carbon atoms or an alkyl group having 2 to 5 carbon atoms that has an aryl group having 6 to 14 carbon atoms. All other of R.sup.1-R.sup.3 and all other of R.sup.4-R.sup.6 each represent, independently of one another, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 14 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms.

##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).

The present invention relates to an electrophotographic photoreceptor comprising, on a conductive base: a charge generation layer; and a charge transport layer having a film thickness of 15 μm to 40 μm, wherein the charge transport layer is an outermost layer, and the charge transport layer contains an inorganic filler and a hydrocarbon compound represented by the following Formula (1).

An electrophotographic photoreceptor includes a conductive substrate including an outer peripheral surface treated with a silazane; and a photosensitive layer on the outer peripheral surface of the conductive substrate. The photosensitive layer includes a charge generating material and a charge transporting material.

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.

There is provided an electrophotographic photoreceptor including: a conductive support; and a photosensitive layer and a protective layer containing a cured product obtained by curing a curable compound, which are sequentially disposed on the conductive support. An area ratio A/B is 0.0045 or less, where A is an absorbance area at a wavelength of 1647 cm.sup.−1 to 1627 cm.sup.−1 and B is an absorbance area of a peak at a wavelength of 1800 cm.sup.−1 to 1647 cm.sup.−1 in an infrared absorption spectrum measurement of the protective layer. The photosensitive layer contains at least a hole transport material (HTM) and a radical acceptor compound. The electrophotographic photoreceptor is an electrophotographic photoreceptor including a protective layer with a high curing degree and having good initial electrical characteristics, excellent strong exposure characteristics, and excellent transfer repeatability.

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer on the conductive substrate, and a photosensitive layer on the undercoat layer, in which the undercoat layer is formed of a cured product of a composition that contains a reactive group-containing triarylamine compound, a curing agent, and an electron transport material and that has a butyral resin content of 0 mass % or more and 5 mass % or less relative to all solid components in the undercoat layer.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer and contains a charge generating material, a hole transport material, an electron transport material, and a polyarylate resin. The polyarylate resin includes repeating units represented by formulas (1), (2), and (3).

##STR00001##

A ratio n.sub.1/n.sub.2 of the number n.sub.1 of repeats of the repeating unit represented by formula (1) to the number n.sub.2 of repeats of the repeating unit represented by formula (2) is at least 1.0.

An electrophotographic photoreceptor includes a conductive support; and an undercoat layer and a photosensitive layer stacked on the conductive support, in which the undercoat layer contains crystalline electron transport compound particles. In X-ray diffraction measurement performed on the undercoat layer in a thickness direction, a maximum intensity peak has a half-width of 5° or less, and a maximum value Nmax among orientation indices N expressed by equation (1) below is 1 or more and 3 or less:

[00001]$\begin{array}{cc}\text{Orientation index}\text{=}\frac{l_1}{\frac{{\displaystyle .Math.l_1}}{\frac{l_2}{{\displaystyle .Math.l_2}}}}& \text{­­­(1)}\end{array}$

where I.sub.1 represents a relative integral intensity of each of peaks in the X-ray diffraction measurement performed on the undercoat layer in the thickness direction, and I.sub.2 represents a relative integral intensity of each of peaks in X-ray diffraction measurement performed on the undercoat layer processed into a powder form having a volume-average particle diameter of 5 .Math.m or less.

A compound is represented by general formula (1). In general formula (1), R.sup.1 and R.sup.2 each represent, independently of one another, a hydrogen atom, a methyl group, or an ethyl group, and a sum of the number of carbon atoms of the chemical group represented by R.sup.1 and the number of carbon atoms of the chemical group represented by R.sup.2 is 2. R.sup.3 and R.sup.4 each represent, independently of one another, a hydrogen atom, a methyl group, or an ethyl group, and a sum of the number of carbon atoms of the chemical group represented by R.sup.3 and the number of carbon atoms of the chemical group represented by R.sup.1 is 2. A photosensitive layer of an electrophotographic photosensitive member contains at least a charge generating material, a hole transport material, and a binder resin. The hole transport material includes a compound represented by general formula (1) ##STR00001##