Abstract: There is provided a charging member exhibiting stable charging performance even after the use for a long period of time. The charging member includes a support and a surface layer on the support, the surface layer includes polymetalloxane containing at least one metal atom selected from the group consisting of aluminum, zirconium, titanium, and tantalum, and a group represented by the following formula (1) or (2) is bonded to at least the one metal atom in the polymetalloxane, wherein X represents an atomic group required for forming a ring, A1 and A2 each independently represent a hydrogen atom or an alkyl group, and a symbol “*” represents a binding site with a metal atom in the polymetalloxane.

Abstract: There is provided a charging member exhibiting stable charging performance even after the use for a long period of time. The charging member includes a support and a surface layer on the support, the surface layer includes polymetalloxane containing at least one metal atom selected from the group consisting of aluminum, zirconium, titanium, and tantalum, and a group represented by the following formula (1) or (2) is bonded to at least the one metal atom in the polymetalloxane, wherein X represents an atomic group required for forming a ring, A1 and A2 each independently represent a hydrogen atom or an alkyl group, and a symbol “*” represents a binding site with a metal atom in the polymetalloxane.

Abstract: Concerned with a charging member in the conductive surface layer of which the conductive particles are so kept from agglomerating as to make charging performance not easily change even where the surface layer expands and contracts repeatedly in various environments. The charging member is a charging member having a conductive substrate and formed on the substrate a conductive elastic layer and a conductive surface layer. The elastic layer contains a polymer having a unit coming from ethylene oxide, and the surface layer contains a binder resin and graphitized particles. The binder resin contains a resin having in the molecule a urethane linkage or a siloxane linkage, or a urethane linkage and a siloxane linkage, and the graphitized particles have a graphite (002) plane lattice spacing of from 0.3362 nm or more to 0.3449 nm or less.

Abstract: The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (—O—C2H4—) and L represents polysiloxane having at least a SiO4/2(Q) unit or a SiO3/2(T) unit.

Abstract: The present invention provides an electrophotographic member capable of more definitely suppressing occurrence of a C set image. The electrophotographic member has a surface layer including a modified polysiloxane having a structure represented by the following formula (1). In the formula (1), G represents a bivalent group having an ethylene oxide chain represented by (—O—C2H4—) and L represents polysiloxane having at least a SiO4/2(Q) unit or a SiO3/2(T) unit.

Abstract: When a polymer blend of an NBR and an alkylene oxide-polymerized polymer is used as the electro-conductive elastic layer of an electro-conductive member for electrophotography, a change in shape of the electro-conductive member occurs owing to its expansion due to water absorption, thereby causing image unevenness in some cases. In addition, when the ratio at which the alkylene oxide-polymerized polymer is blended is reduced for suppressing the shape change due to water absorption, image unevenness resulting from the insufficiency of electro-conductivity occurs in some cases. When an electro-conductive member for electrophotography having an electro-conductive elastic layer containing an NBR to which a specific alkylene oxide oligomer is graft-bonded is used, high ionic electro-conductivity is obtained and a change in its shape due to water absorption is reduced.

Abstract: Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.

Abstract: When a polymer blend of an NBR and an alkylene oxide-polymerized polymer is used as the electro-conductive elastic layer of an electro-conductive member for electrophotography, a change in shape of the electro-conductive member occurs owing to its expansion due to water absorption, thereby causing image unevenness in some cases. In addition, when the ratio at which the alkylene oxide-polymerized polymer is blended is reduced for suppressing the shape change due to water absorption, image unevenness resulting from the insufficiency of electro-conductivity occurs in some cases. When an electro-conductive member for electrophotography having an electro-conductive elastic layer containing an NBR to which a specific alkylene oxide oligomer is graft-bonded is used, high ionic electro-conductivity is obtained and a change in its shape due to water absorption is reduced.

Abstract: Provided is the following charging member of an electrophotographic apparatus. The charging member suppresses the occurrence of each of a streak-like image, a spot-like image, and a rough image that occur when image formation is performed over a long time period. Also provided are a process cartridge and an electrophotographic apparatus each having the charging member. A compound having a siloxane dendrimer structure at a vinyl group or a side chain of a vinyl polymer is incorporated into the surface layer of the charging member comprising a conductive substrate and the surface layer.

Abstract: The present invention provides a charging roller having a stable chargeability and capable of preventing occurrence of “fogging” on an electrophotographic image. The invention relates to a contact-charging type charging roller which includes a conductive support and a surface layer. The surface layer contains a binder, resin particles containing a carbon black dispersed in the binder, and graphitized particles dispersed in the binder; and the surface layer has, on its surface, convex portions derived from the resin particles, and convex portions derived from the graphitized particles. These convex portions have a specific relationship.

Abstract: Concerned with a charging member in the conductive surface layer of which the conductive particles are so kept from agglomerating as to make charging performance not easily change even where the surface layer expands and contracts repeatedly in various environments. The charging member is a charging member having a conductive substrate and formed on the substrate a conductive elastic layer and a conductive surface layer. The elastic layer contains a polymer having a unit coming from ethylene oxide, and the surface layer contains a binder resin and graphitized particles. The binder resin contains a resin having in the molecule a urethane linkage or a siloxane linkage, or a urethane linkage and a siloxane linkage, and the graphitized particles have a graphite (002) plane lattice spacing of from 0.3362 nm or more to 0.3449 nm or less.

Abstract: The present invention provides a charging roller having a stable chargeability and capable of preventing occurrence of “fogging” on an electrophotographic image. The invention relates to a contact-charging type charging roller which includes a conductive support and a surface layer. The surface layer contains a binder, resin particles containing a carbon black dispersed in the binder, and graphitized particles dispersed in the binder; and the surface layer has, on its surface, convex portions derived from the resin particles, and convex portions derived from the graphitized particles. These convex portions have a specific relationship.