Abstract: The charging member includes: an electroconductive support; and an electroconductive elastic layer serving as a surface layer, wherein the elastic layer contains a binder, and holds electrically insulating hollow particles in such a state that at least a part of each of the hollow particles is exposed at a surface of the elastic layer, wherein the charging member has protrusions derived from the hollow particles in an outer surface of the charging member, and the outer surface of the charging member includes an outer surface of the elastic layer and an outer surface of an exposed portion of each of the hollow particles, and wherein the protrusions each have a depression in an outer surface of each of the protrusions, and an edge of the depression constitutes an apex in each of the protrusions.

Abstract: The charging member includes: an electroconductive support; and an electroconductive elastic layer serving as a surface layer, wherein the elastic layer contains a binder, and holds electrically insulating hollow particles in such a state that at least a part of each of the hollow particles is exposed at a surface of the elastic layer, wherein the charging member has protrusions derived from the hollow particles in an outer surface of the charging member, and the outer surface of the charging member includes an outer surface of the elastic layer and an outer surface of an exposed portion of each of the hollow particles, and wherein the protrusions each have a depression in an outer surface of each of the protrusions, and an edge of the depression constitutes an apex in each of the protrusions.

Abstract: To provide a charging member which suppresses the generation of density nonuniformity in an electrophotographic image caused by charge nonuniformity due to adhesion of charged substances, such as toner particles. There is provided a charging member which has a surface layer, the surface layer includes conductive zinc oxide whiskers each formed of a nuclear portion and four needle crystal portions extending radially outward therefrom, and the needle crystal portions are exposed to form convex portions of a surface of the surface layer.

Abstract: A charging member includes an electro-conductive substrate, an elastic layer, and a surface layer provided in this order. The elastic layer has, on an outer surface thereof, concave portions that are independent of each other, and hold insulating particles. The insulating particle is exposed to the surface of the elastic layer. A site in which an outer edge of the projection image derived from each of the insulating particles and an outer edge of a projection image derived from each of the concave portions are separated, exists. The charging member has convex portions derived from the insulating particles exposed to the surface of the elastic layer, and concave portions derived from the concave portions of the elastic layer. The surface layer has a volume resistivity of 1.0×1015 ?cm or more.

Abstract: It is intended to provide a charging member capable of maintaining high charging performance even when used over a long period. The charging member has an electroconductive support and an electroconductive elastic layer as a surface layer, wherein the electroconductive elastic layer has a roughened surface, and the electroconductive elastic layer has an average Martens' hardness Mc of 2 N/mm2 or larger and 20 N/mm2 or smaller measured with an indentation strength of 0.04 mN at a core surface defined according to three dimensional surface texture standard (ISO 25178-2:2012), and has an average viscosity Vc of 70 mV or smaller measured in a 2 ?m square field of view under a scanning probe microscope.

Abstract: Provided a charging member comprising an electro-conductive support and an electro-conductive surface layer, the surface layer including on the outer surface thereof, concave portions that are independent of each other, and holding an insulating particle in each of the concave portions, the insulating particle being exposed to the surface of the charging member and forms a convex portion on the surface of the charging member, in an orthogonal projection image of which the concave portions and the insulating particle are projected on a surface of the electro-conductive support, a site in which an outer edge of a projection image derived from the insulating particle and an outer edge of a projection image derived from each of the concave portions are separated, exists, and a part of a wall of each of the concave portions constitutes a part of the surface of the charging member.

Abstract: Provided a charging member including an electro-conductive support and a surface layer, the surface layer having in an outer surface thereof, concave portions and holding an elastic particle in each of the concave portions, the elastic particle being exposed at a surface of the charging member to form a convex portion in the surface of the charging member, and a part of a wall of each of the concave portions constituting a part of the surface of the charging member.

Abstract: Provided a charging member including an electro-conductive support and a surface layer, the surface layer having in an outer surface thereof, concave portions and holding an elastic particle in each of the concave portions, the elastic particle being exposed at a surface of the charging member to form a convex portion in the surface of the charging member, and a part of a wall of each of the concave portions constituting a part of the surface of the charging member.

Abstract: Provided a charging member comprising an electro-conductive support and an electro-conductive surface layer, the surface layer including on the outer surface thereof, concave portions that are independent of each other, and holding an insulating particle in each of the concave portions, the insulating particle being exposed to the surface of the charging member and forms a convex portion on the surface of the charging member, in an orthogonal projection image of which the concave portions and the insulating particle are projected on a surface of the electro-conductive support, a site in which an outer edge of a projection image derived from the insulating particle and an outer edge of a projection image derived from each of the concave portions are separated, exists, and a part of a wall of each of the concave portions constitutes a part of the surface of the charging member.

Abstract: To provide a charging member which suppresses the generation of density nonuniformity in an electrophotographic image caused by charge nonuniformity due to adhesion of charged substances, such as toner particles. There is provided a charging member which has a surface layer, the surface layer includes conductive zinc oxide whiskers each formed of a nuclear portion and four needle crystal portions extending radially outward therefrom, and the needle crystal portions are exposed to form convex portions of a surface of the surface layer.

Abstract: The present invention provides a charging member having an elastic layer on a surface thereof in which occurrence of compression set is reduced. The charging member includes an electro-conductive support and an elastic layer provided on the support as a surface layer, wherein the elastic layer is a rubber layer made of a crosslinked product of a rubber mixture including acrylonitrile butadiene rubber and polybutadiene, the polybutadiene includes 1,2-syndiotactic polybutadiene, and the elastic layer is formed by irradiating a surface of the rubber layer with electron rays.

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: 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: A roller for electrophotography has an electrically conductive support and an elastic layer as a surface layer. The elastic layer holds spherical particles each having a plane on their peripheral surfaces, in such a way that part or the whole of the plane comes exposed to the surface of the elastic layer, and the plane of each of the spherical particles standing exposed to the surface of the elastic layer and a plane that is i) orthogonal to a straight line passing through an axis of a section orthogonal to an axis of the roller for electrophotography and being directed toward the peripheral surface of the roller for electrophotography and is ii) tangential to the peripheral surface of the roller for electrophotography form an acute internal angle.

Abstract: To provide a charging member which suppresses the generation of density nonuniformity in an electrophotographic image caused by charge nonuniformity due to adhesion of charged substances, such as toner particles. There is provided a charging member which has a surface layer, the surface layer includes conductive zinc oxide whiskers each formed of a nuclear portion and four needle crystal portions extending radially outward therefrom, and the needle crystal portions are exposed to form convex portions of a surface of the surface layer.

Abstract: An electrophotographic member including an electrically conductive substrate and an electrically conductive resin layer corresponding to a surface layer. The resin layer includes electrically conductive particles and a binder resin.

Abstract: An electrophotographic member including an electrically conductive substrate and an electrically conductive resin layer corresponding to a surface layer. The resin layer includes electrically conductive particles and a binder resin.

Abstract: The conductive member has a conductive support and a conductive elastic layer. The elastic layer is a mixture containing an electron conductive agent and a binder polymer, or a cured product thereof, and the electron conductive agent contains a carbon black satisfying the following characteristics: (i) an average primary particle diameter is 20 nm or more and 30 nm or less; (ii) a DBP oil absorption is 40 ml/100 g or more and 70 ml/100 g or less, and the total amount of CO and CO2 generated by temperature programmed desorption/mass spectrometry is 0.30 mass % or more and 0.80 mass % or less with reference to the carbon black; and (iii) the amount of SO2 generated by the temperature programmed desorption/mass spectrometry is 0.05 mass % or more with reference to the carbon black.

Abstract: The present invention provides a charging member having an elastic layer on a surface thereof in which occurrence of compression set is reduced. The charging member includes an electro-conductive support and an elastic layer provided on the support as a surface layer, wherein the elastic layer is a rubber layer made of a crosslinked product of a rubber mixture including acrylonitrile butadiene rubber and polybutadiene, the polybutadiene includes 1,2-syndiotactic polybutadiene, and the elastic layer is formed by irradiating a surface of the rubber layer with electron rays.

Abstract: A roller for electrophotography is provided which has an electrically conductive support and an elastic layer as a surface layer, where the elastic layer holds spherical particles each having a plane on their peripheral surfaces, in such a way that part or the whole of the plane comes exposed to the surface of the elastic layer, and the plane of each of the spherical particles standing exposed to the surface of the elastic layer and a plane that is i) orthogonal to a straight line passing through an axis of a section orthogonal to an axis of the roller for electrophotography and being directed toward the peripheral surface of the roller for electrophotography and is ii) tangential to the peripheral surface of the roller for electrophotography forms an acute internal angle.