The present invention relates to a single-layer type electrophotographic photoreceptor for positive charging, comprising: a conductive support; and a photosensitive layer disposed on the conductive support and comprising a binder resin, a charge generation material, a hole transport material and a specific electron transport material within the same layer, wherein the photosensitive layer contains a specific aromatic compound.

A photosensitive layer of an electrophotographic photosensitive member is a single layer and contains a charge generating material, a hole transport material, a first electron transport material, a second electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units (1), (2), (3), and (4).

##STR00001##

A percentage of the number of repeats of the repeating unit (3) relative to the total of the number of repeats of the repeating units (1) and the number of repeats of the repeating unit (3) is greater than 0% and less than 20%. The first electron transport material includes a compound represented by formula (A15) or (A16).

##STR00002##

The second electron transport material includes a compound represented by formula (B10), (B11), (B12), (B13), or (B14)

##STR00003##

A single-layer photosensitive layer included in an electrophotographic photosensitive member contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units (1), (2), (3), and (4).

##STR00001##

The percentage of the number of repeats of the repeating unit (3) relative to the total of the number of repeats of the repeating unit (1) and the number of repeats of the repeating unit (3) is greater than 0% and less than 20%. The hole transport material has one nitrogen atom.

A single-layer photosensitive layer included in an electrophotographic photosensitive member contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4).

##STR00001##

The percentage of the number of repeats of the repeating unit represented by formula (3) relative to a total of the number of repeats of the repeating unit represented by formula (1) and the number of repeats of the repeating unit represented by formula (3) is greater than 0% and less than 20%.

As a new negatively charging electrophotographic photoconductor having a cured resin based protective layer that does not necessitate a heat treatment for enhancing the electric characteristics, a negatively charging electrophotographic photoconductor having a structure including a photosensitive layer and a protective layer containing a cured product formed by curing a curable compound on a conductive support in this order, the photosensitive layer containing at least a hole transporting material (HTM) and a radical acceptor compound or an electron transporting material (ETM), the hole transporting material (HTM) being a compound having an energy difference between a HOMO level and a LUMO level of 3.60 eV or less, and having a HOMO level of −4.50 eV or less based on the vacuum level is proposed.

Provided are an electrophotographic photoconductor being resistant to abrasion even in long-term use, having highly sensitive electric characteristics, being capable of maintaining a high retention rate, and being capable of providing a stable image without filming, a method of manufacturing the same, and an electrophotographic device. The photoconductor includes an electroconductive substrate (1), a charge generation layer (3), and a charge transport layer (4); the charge transport layer contains a hole transport material, a resin binder, an electron transport material, and an inorganic oxide; the charge generation layer contains a charge generation material; the masses of the hole transport material, the resin binder, the electron transport material, and the inorganic oxide in the charge transport layer respectively denoted by a to d satisfy 1.5≤b/a≤5.7, 0.005≤c/a≤0.35, 0.05≤d/a≤0.70, a≥c+d, and c/d≥0.01; the hole transport material contains a compound expressed by formula (A-1); and the charge generation material contains titanyl phthalocyanine having an exothermic peak at 251±5° C., a half-value width of the exothermic peak equal to or less than 15° C., and a heating value equal to or greater than 1.0 mJ/mg when a temperature rise condition is 20° C./min in differential scanning calorimetry, and having an X-ray diffraction peak at 27.2±0.3°. ##STR00001##

An electrophotographic photoreceptor comprising at least a photosensitive layer on a conductive substrate, wherein the photosensitive layer is a laminate having a charge transport layer and a charge generation layer, the charge transport layer contains four or more types of compounds each having a maximum absorption wavelength falling within a wavelength range of from 300 nm to 600 nm in a tetrahydrofuran solution at 25° C., and maximum absorption wavelengths falling within the wavelength range of at least four types of the compounds of said four or more types of the compounds are separated from each other by 10 nm or more.

A photoconductor that includes, for example, a supporting substrate, an optional ground plane layer, an optional hole blocking layer, an optional adhesive layer, a photogenerating layer, and a charge transport layer, and where the charge transport layer contains a mixture of a charge transport component and a polycarbonate AP.

A quinone derivative is represented by general formula (1), (2), or (3). In general formulae (1), (2), and (3), R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.21, R.sup.22, R.sup.23, and R.sup.24 each represent, independently of one another, a hydrogen atom, a cyano group, a halogen atom, an optionally substituted alkyl group having a carbon number of 1-6, or an optionally substituted alkoxy group having a carbon number of 1-6. R.sup.5, R.sup.6, R.sup.15, R.sup.16, R.sup.25, and R.sup.26 each represent, independently of one another, an optionally substituted alkyl group having a carbon number of 1-6, an optionally substituted alkoxy group having a carbon number of 1-6, an optionally substituted aryl group having a carbon number of 6-14, an optionally substituted aralkyl group having a carbon number of 7-12, or an optionally substituted cycloalkyl group having a carbon number of 3-10.

##STR00001##

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##