In a positively charging single layer type electrophotographic photoreceptor having an over coat layer, an electrophotographic photoreceptor that is excellent in mechanical strength, electric characteristics, and adhesiveness, an electrophotographic photoreceptor cartridge, and an image formation device are provided. In a positively charging electrophotographic photoreceptor having a single layer type photosensitive layer and an over coat layer, the Martens hardness on the photoreceptor surface satisfies the prescribed condition, and preferably the photosensitive layer satisfies the particular relational expression of the contents and the molecular weights of the hole transporting substance and the electron transporting substance contained therein, thereby solving the problem.

An improved overcoat layer for an organic photoconductor drum of an electrophotographic image forming device is provided. The overcoat layer is prepared from a curable composition including a crosslinkable siloxane, an acrylic polymer with pigment affinic groups, nano metal oxide particles sized less than 400 nm in combination with a urethane acrylate resin having at least 6 functional groups. The outermost layer of an organic photoconductors is coated with the overcoat formulation of the present invention then cured. The resulting cured overcoated organic photoconductor has improved wear resistance and importantly does not negatively altering the electrophotographic properties of the organic photoconductor.

An improved overcoat layer for an organic photoconductor drum of an electrophotographic image forming device is provided. The overcoat layer is prepared from a curable composition including a crosslinkable siloxane, nano metal oxide particles sized less than 400 nm in combination with a urethane acrylate resin having at least 6 functional groups. The outermost layer of an organic photoconductors is coated with the overcoat formulation of the present invention then cured. The resulting cured overcoated organic photoconductor has improved wear resistance and importantly does not negatively altering the electrophotographic properties of the organic photoconductor.

A charging member includes a conductive base material; an elastic layer that is provided on the conductive base material and has a storage elastic modulus G of 5.0 MPa or less at 100 Hz; and a surface layer that is provided on the elastic layer, in which in a Cole-Cole plot obtained by measuring the charging member in a range of 1 MHz to 0.1 Hz by an alternating current impedance method, a resistance component Ra of a capacitive semicircle including 2.5 kHz is 6.3×104Ω or less.

A charging member includes a conductive base material; an elastic layer that is provided on the conductive base material and has a storage elastic modulus G of 5.0 MPa or less at 100 Hz; and a surface layer that is provided on the elastic layer, in which in a Cole-Cole plot obtained by measuring the charging member in a range of 1 MHz to 0.1 Hz by an alternating current impedance method, a resistance component Ra of a capacitive semicircle including 2.5 kHz is 6.3×104Ω or less.

Provided is an electrophotographic member including: a substrate having electroconductivity; and a monolayer surface layer formed on the substrate. The surface layer has a matrix containing a crosslinked resin as a binder, and holds at least one particle containing an inorganic layered compound having an ion exchange capacity so that at least a part of the at least one particle is exposed from an outer surface of the surface layer. An elastic modulus of the matrix, measured in a region of a section in a thickness direction of the surface layer from the outer surface of the surface layer to a depth of 0.1 μm, is 200 MPa or more.

Provided is an electrophotographic photosensitive member including an electroconductive support, a photosensitive layer, and a protection layer, wherein the protection layer comprises an electroconductive particle, the electroconductive particle has a surface comprising a metal oxide containing a titanium atom and a niobium atom, an atomic concentration ratio of the niobium atom to the titanium atom in the metal oxide is 0.01 to 0.20, the electroconductive particle is surface-treated with a compound having a silicon atom, a content ratio of the electroconductive particle in the protection layer is 5 vol % or more and less than 40 vol % with respect to a total volume of the protection layer, and relative concentrations of a plurality of atoms at a surface of the protection layer, which are determined by X-ray photoelectron spectroscopy, satisfy specific conditions.

A process cartridge that is detachable from a main body of an electrophotographic apparatus, in which a surface protective layer of an electrophotographic photosensitive member contains an electroconductive particle; the content of the electroconductive particle is 20.0 to 70.0% by volume of the surface protective layer; the surface protective layer has a volume resistivity of 1.0×10.sup.9 to 1.0×10.sup.14 Ω.Math.cm; a toner particle has at least one multivalent metal element selected from the group consisting of aluminum, magnesium, calcium, and iron; and a total content of the multivalent metal elements in the toner particle, as measured by coupled induction plasma atomic emission spectrometry (ICP-AES), is 0.10 to 1.25 μmol/g.

To provide an image formation device that is capable of printing without problems in chargeability, leak resistance, gas resistance, and abrasion resistance, even with a contact charging system, and an electrophotographic photoreceptor and an electrophotographic photoreceptor cartridge used in the image formation device. The problem can be solved by an image formation device of a contact charging system including a positively charging electrophotographic photoreceptor including a single layer photosensitive layer and an over coat layer containing a cured product formed by curing a curable compound.

An improved overcoat layer for an organic photoconductor drum of an electrophotographic image forming device is provided. The overcoat layer is prepared from a curable composition including a crosslinkable siloxane, nano metal oxide particles sized less than 400 nm in combination with a urethane acrylate resin having at least 6 functional groups. The outermost layer of an organic photoconductors is coated with the overcoat formulation of the present invention then cured. The resulting cured overcoated organic photoconductor has improved wear resistance and importantly does not negatively altering the electrophotographic properties of the organic photoconductor.