A process cartridge configured to be detachably attachable to a main body of an electrophotographic image forming apparatus, in which an occurrence of an image failure is suppressed, wherein the process cartridge includes an electrophotographic photosensitive member and a cleaning member arranged in contact with the electrophotographic photosensitive member, wherein an elastic deformation modulus of a surface layer of the electrophotographic photosensitive member is 35% or larger, and the cleaning member is formed of a urethane foam, wherein a density of the urethane foam is 200 to 500 kg/cm.sup.3, and a 25% compressive load of the urethane foam is 0.3 MPa or smaller.

Provided are a process cartridge and an electrophotographic apparatus each suppressed in fluctuation in charging potential at the time of its long-term use. The process cartridge includes: an electrophotographic photosensitive member having a surface layer containing a resin and a charge-transporting substance; and a charging member configured to charge the electrophotographic photosensitive member, wherein an average of Martens hardnesses of the surface layer of the electrophotographic photosensitive member measured at a pushing force of 7 mN is 245 N/mm.sup.2 or more, and wherein in a core defined by three-dimensional surface texture standards (ISO 25178-2:2012) of the surface of the charging member, an average of Martens hardnesses measured at a pushing force of 0.04 mN is 2 N/mm.sup.2 or more and 20 N/mm.sup.2 or less, and an average of adhesivenesses measured with a scanning probe microscope in a field of view of 2-micrometer square is 70 mV or less.

The present invention relates to an electrophotographic photoreceptor which is a positive charging type electrophotographic photoreceptor comprising a conductive support and a photosensitive layer on the conductive support, wherein the photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin in the same layer, and a residual potential VL.sub.1 at a point at which an exposure amount for forming a latent image is 0.3 ?J/cm.sup.2 is equal to or lower than 130 V when an initial surface potential V0 is set to +700 V, exposure with monochromatic light of 780 nm is performed and measurement is performed by a dynamic method.

An electrophotographic photoreceptor according to the present invention includes a conductive support, a photosensitive layer, and a protective layer disposed in sequence. The protective layer includes a cured product of a composition containing a radically polymerizable compound, a charge transporting material exhibiting a maximal absorption wavelength of 40550 nm, and a photopolymerization initiator of a single-molecule system; and a following Expression (A) is satisfied:
G=Eox(D/D.sup.+)Ered(A.sup./A)E*0.2 [eV]Expression (A):
G represents a free energy change, Eox(D/D.sup.+) represents an oxidation potential of the charge transporting material, Ered(A.sup./A) represents a reduction potential of the photopolymerization initiator, and E* represents an excitation energy of the charge transporting material.

The present invention relates to an electrophotographic photoreceptor which is a positive charging type electrophotographic photoreceptor comprising a conductive support and a photosensitive layer on the conductive support, wherein the photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin in the same layer, and a residual potential VL.sub.1 at a point at which an exposure amount for forming a latent image is 0.3 ?J/cm.sup.2 is equal to or lower than 130 V when an initial surface potential V0 is set to +700 V, exposure with monochromatic light of 780 nm is performed and measurement is performed by a dynamic method.

An electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer having a single-layer structure. The photosensitive layer contains a charge generating material, an electron transport material, a polycarbonate resin, and a hole transport material. The electron transport material includes a compound having a halogen atom and represented by general formula (1), (2), (3), (4), or (5). The hole transport material includes a compound represented by general formula (20), (21), (22), (23), (24), (25), (26), or (27). A charge of calcium carbonate as measured by charging the calcium carbonate through friction with the photosensitive layer is at least +6.5 C/g. A Vickers hardness of the photosensitive layer at 45 C. is at least 17.0 HV.

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Provided is an electrographic photoconductor resistant to surface discharge and having good wear resistance. The electrographic photoconductor has a conductive support and a photosensitive layer disposed on the conductive support, the photosensitive layer containing a charge generation material and a charge transport material. A layer forming the surface of the electrographic photoconductor contains a resin binder forming the layer and a layered carbide dispersed in the resin binder. The layer forming the surface has a light transmittance in the range of 20 to 98% at a wavelength of 350 to 800 nm.

A photoreceptor for electrophotography and an electrophotography device having the same reduces wear loss of the photoreceptor surface and stably obtaining a favorable image for long time. The photoreceptor for electrophotography includes a conductive substrate and a charge transport layer provided on the conductive substrate. The charge transport layer contains a charge transport material, a resin binder, and an inorganic oxide filler surface-treated with a silane coupling agent. A difference (SPa) in a dipole-dipole force component that is a Hansen solubility parameter between the charge transport material and the silane coupling agent satisfies a relationship SPa<1.0. A difference (SPb) in a London dispersion force component that is a Hansen solubility parameter between the resin binder and the silane coupling agent satisfies a relationship SPb<2.5.

Provided is an electrophotographic photoreceptor including a conductive support, a photosensitive layer, and a surface protective layer disposed in sequence. The surface protective layer includes a cured product of a composition containing a polymerizable compound, a charge transporting material, and at least two polymerization initiators. The polymerization initiators include an acyl phosphine oxide and an O-acyl oxime.

The invention provides an electrophotographic photoreceptor, which undergoes little abrasion over long term use and is able to develop a stable image, as well as a method of producing the same and an electrophotographic device including the same. The electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer that contains an inorganic oxide and that is formed on the conductive substrate from a coating liquid. A test slurry containing 20% by mass of the inorganic oxide dispersed in a solvent for forming the coating liquid has a light transmittance of 40% or more in a test case where light having a wavelength of 780 nm irradiates the test slurry.