Provided are a photoconductor for electrophotography that has sufficiently high sensitivity and excellent potential stability during repeated printing in various environments, and does not cause problems, such as deterioration of gradation or generation of memory images, especially when applied to monochrome high-speed printers and small medium-speed tandem color printers, as well as a method of manufacturing the photoconductor for electrophotography, and an electrophotographic equipment. The positively-charged photoconductor for electrophotography includes a conductive substrate; and a photosensitive layer formed on the conductive substrate, in which the photosensitive layer contains electron transport materials, and at least one of the electron transport materials contains an azoquinone derivative having a structure represented by general formula (ET1) below:

##STR00001##

A compound of the general formula ##STR00001##
a process for the production of the compound and its use in electronic devices, especially electroluminescent devices. Improved efficiency, stability, manufacturability, or spectral characteristics of electroluminescent devices are provided when the compound of formula I is used as host material for phosphorescent emitters in electroluminescent devices.

The process cartridge includes an electrophotographic photosensitive member having a first support and a photosensitive layer; and a charging member. In the photosensitive member when an electric current is measured which flows when a voltage is applied to a surface while being varied, a gradient a.sub.1 of a low electric field region and a gradient a.sub.2 of a high electric field region satisfy a.sub.2/a.sub.1≥1.50, in a graph. The charging member includes a second support having an electroconductive outer surface, and a second electroconductive layer including a matrix and a plurality of domains being dispersed in the matrix, at least a portion of the domain is exposed to an outer surface which includes at least the matrix and at least a portion of the domain, and a volume resistivity ρ.sub.M of the matrix is 1.00×10.sup.5 times or higher of a volume resistivity ρ.sub.D of the domain.

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a charge transport material, at least one of a polyester resin that has a constitutional unit having an aromatic ring or a polycarbonate resin that has a constitutional unit having an aromatic ring, and a compound (1) represented by Formula (1) and having a melting point of 40° C. or higher,

##STR00001## in Formula (1), Ar represents an aromatic ring that may have a substituent, L represents a single bond, an oxygen atom, or a sulfur atom, R represents an alkyl group having 1 or more and 10 or less carbon atoms, an aryl group having 6 or more and 20 or less carbon atoms, or an aralkyl group having 7 or more and 20 or less carbon atoms, and n represents an integer of 1 or greater.

An image forming unit includes a photoreceptor and a charging member that comes into contact with a surface of the photoreceptor and charges the photoreceptor, in which the photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, the charge transport layer contains at least one of a polyester resin that has a constitutional unit having an aromatic ring or a polycarbonate resin that has a constitutional unit having an aromatic ring, the charging member includes a support member and an elastic layer disposed on the support member, and the elastic layer has a storage elastic modulus G′ of 5.0 MPa or less at a frequency of 100 Hz in dynamic viscoelasticity measurement under a temperature condition of 24° C.

The present disclosure provides an electrophotographic photosensitive member having excellent dispersibility of fluorine atom-containing resin particles, and excellent durability, with an occurrence of a ghost suppressed. In the electrophotographic photosensitive member having a surface layer, the surface layer includes a fluorine atom-containing resin particle, a binder material, a charge transport substance, and a polymer A having a specific structural unit, wherein the binder material is a thermoplastic resin, and a film thickness of the surface layer is 35 μm or larger and 50 μm or smaller.

The present disclosure provides an electrophotographic photosensitive member having a surface layer that is excellent in dispersibility of a fluorine atom-containing resin particle and suppresses a potential fluctuation at the time of repeated use. The electrophotographic photosensitive member having the surface layer, wherein the surface layer includes the fluorine atom-containing resin particle, a binder material, and a polymer A having a specific structural unit.

An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. $\begin{array}{cc}0.60\leqq \frac{V}{\left(Q/S\right)\times \left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}& \left(1\right)\end{array}$
In formula (1), Q represents a charge amount [C] of the circumferential surface of the image bearing member, S represents a charge area [m.sup.2] of the charged circumferential surface of the image bearing member, d represents a film thickness [m] of the photosensitive layer, co represents vacuum permittivity [F/m], and V represents a value calculated in accordance with formula V=V.sub.0−V.sub.r.

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 photoreceptor includes a conductive support, an undercoat layer on the conductive support, and a charge generation layer on the undercoat layer, in which the charge generation layer contains a phthalocyanine compound, the undercoat layer contains an electron transport compound, and a difference between an energy level of the lowest unoccupied molecular orbital of the phthalocyanine compound and an energy level of the lowest unoccupied molecular orbital of the electron transport compound is less than 0.45 eV.