Abstract: To provide a charging member that can not easily cause faulty cleaning on a photosensitive member while having a flexibility high enough to form a nip between it and the photosensitive member in a sufficient width. The charging member has an electro-conductive support and an elastic layer that is a surface layer, which elastic layer has at its surface a region having been cured by irradiation with electron rays, where this region supports spherical polyethylene particles in such a state that the spherical polyethylene particles are exposed to the surface of the elastic layer, thereby making the surface roughened.

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: 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: An object of the present invention is to provide a charging member in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method, and a process cartridge and an electrophotographic apparatus having the charging member. The present invention provides a charging member comprising a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

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.

Abstract: A charging member has a surface layer. The surface layer contains a polysiloxane having a first unit, a second unit and a third unit each of which is represented by a specific formula. The ratio of the sum of the mole numbers of the first and second units to the sum of the mole numbers of the first to third units is in a specific range.

Abstract: A charging member is provided in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method. Also provided are a process cartridge and an electrophotographic apparatus having the charging member. The charging member includes a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

Abstract: A charging member is provided in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method. Also provided are a process cartridge and an electrophotographic apparatus having the charging member. The charging member includes a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.

Abstract: A charging member has a surface layer. The surface layer contains a polysiloxane having a first unit, a second unit and a third unit each of which is represented by a specific formula. The ratio of the sum of the mole numbers of the first and second units to the sum of the mole numbers of the first to third units is in a specific range.

Abstract: An object of the present invention is to provide a charging member in which a toner, an additive for use in the toner, or the like is hard to adhere to the surface even under repeated use for a long time, and hence the charging and image output are made stable for a long time even if the charging member is used in the DC contact charging method, and a process cartridge and an electrophotographic apparatus having the charging member. The present invention provides a charging member comprising a support, a conductive elastic layer formed on the support, and a surface layer formed on the conductive elastic layer, characterized in that the surface layer contains a polysiloxane having a fluoroalkyl group and an oxyalkylene group, and a process cartridge and an electrophotographic apparatus having the charging member.