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.

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##

The present disclosure provides an electrophotographic photoreceptor including, on a conductive base, at least a photoreceptive layer or alternatively at least the photoreceptive layer and a protective layer laminated on the photoreceptive layer, in which both or either one of the photoreceptive layer and the protective layer contains a perimidine compound represented by general formula (I):

##STR00001##

(wherein X represents hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and m represents an integer of 1 to 6).

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%.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer containing a charge transport portion including a first hole transport material represented by General Formula (1) below, a cured resin, and a cross-linked structure there between: ##STR00001## where Za is a polymerizable functional group with a Structural Formula (2), (3), or (4), Zb is a divalent group with a Structural Formula (6) or (7), Ra, Rb, Rc and Rd each are one of a branched or unbranched alkyl group having from 1 to 6 carbon atoms, an alkoxy group having from 1 to 6 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted styryl group, I is 0 or 1 when Za is (2) or (4) and 1 when Za is (3), m is from 0 to 5, n, o, and p are each from 0 to 4, q is from 1 to 3.

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.

The electrophotographic apparatus includes: an electrophotographic photosensitive member; a charging unit; an image-exposing unit; a charge transfer amount-sensing unit for sensing the amount of charge transferred to the electrophotographic photosensitive member; and an exposed portion potential-controlling unit for controlling the potential of each of the exposed portions of the electrophotographic photosensitive member based on a sensing result, which is obtained by charging the electrophotographic photosensitive member with the charging unit, performing image exposure with the image-exposing unit in at least one light amount weaker than a light amount in which the normalized radius of curvature R of the electrophotographic photosensitive member represented by the following equation (E1), the normalized radius of curvature being obtained by a method of measuring an EV curve, shows a minimum, and in at least two light amounts stronger than the light amount in which the normalized radius of curvature shows the minimum.

[00001]$\begin{array}{cc}R=\frac{{\left[1+{\left(\frac{\mathrm{dy}}{\mathrm{dx}}\right)}^2\right]}^{3/2}}{.Math.\frac{d^2}{{\mathrm{dx}}^2}.Math.}& \left(E1\right)\end{array}$

An electrophotographic photosensitive member has a charge generation layer having a film thickness of 0.2 μm or larger and a charge transport layer on a support, wherein in a case where, at 23.5° C. and 50% RH, the photosensitive member is subjected to operations and measurement of: specific (1), (2), (3) and (4), an absolute value of a slope α of a linear approximation straight line is 4×10.sup.−3 or smaller, in a range where the electric field strength E is 10 to 40 V/μm, which is expressed by a relational expression between a recombination constant P.sub.e and an electric field strength E, which is obtained from a specific graph which has been obtained by repeatedly performing the specific operations and measurement of (1) to (4) while changing I.sub.exp from 0.000 to 1.000 μJ/cm.sup.2 at intervals of 0.001 μJ/cm.sup.2.