Abstract: A developing roller comprising an electroconductive substrate and an electroconductive elastic layer constituted by a single layer on an outer periphery of the substrate. The elastic layer contains a diene-based rubber, has a thickness of 0.30 mm or more, and the elastic layer has a crown shape in which an outer diameter of a center portion in a longitudinal direction along an axis of the substrate is larger than an outer diameter of each of both end portions in the longitudinal direction. Elastic moduli E11, E12 and E13 in a first region of the elastic layer in cross-sections at positions P1, P2 and P3 of the elastic layer are each 500 MPa or more.

Abstract: Provided is an electrophotographic member including: an electroconductive substrate; and an elastic layer on the substrate, the elastic layer constituted by a single layer, the elastic layer containing a silicone rubber having a dimethylsiloxane structure, wherein when a peak top temperature of an ion thermogram derived from the dimethylsiloxane structure, the ion thermogram being measured from a first sample sampled from a first region having a thickness of 0.5 ?m from a first surface of the elastic layer toward a second surface thereof, is represented by T1, and a peak top temperature of an ion thermogram derived from the dimethylsiloxane structure, the ion thermogram being measured from a second sample sampled from a second region corresponding to a thickness of 1.0 ?m to 1.5 ?m from the second surface toward the first surface, is represented by T2, T1 and T2 satisfy a relationship of T1>T2.

Abstract: A developing roller comprising an electroconductive substrate and an electroconductive elastic layer constituted by a single layer on an outer periphery of the substrate. The elastic layer contains a diene-based rubber, has a thickness of 0.30 mm or more, and the elastic layer has a crown shape in which an outer diameter of a center portion in a longitudinal direction along an axis of the substrate is larger than an outer diameter of each of both end portions in the longitudinal direction. Elastic moduli E11, E12 and E13 in a first region of the elastic layer in cross-sections at positions P1, P2 and P3 of the elastic layer are each 500 MPa or more.

Abstract: A developing roller comprising an electroconductive substrate and an electroconductive elastic layer constituted by a single layer on an outer periphery of the substrate. The elastic layer contains a diene-based rubber, has a thickness of 0.30 mm or more, and the elastic layer has a crown shape in which an outer diameter of a center portion in a longitudinal direction along an axis of the substrate is larger than an outer diameter of each of both end portions in the longitudinal direction. Elastic moduli E11, E12 and E13 in a first region of the elastic layer in cross-sections at positions P1, P2 and P3 of the elastic layer are each 500 MPa or more.

Abstract: Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1 ?200 MPa and 10 MPa?E2 ?100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 ?m from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0×10?4 N.

Abstract: An electrophotographic member includes an electro-conductive substrate and an elastic layer containing inorganic particles and a binder resin. The electrophotographic member has a protrusion on an outer surface of the electrophotographic member containing the inorganic particles. At least part of the inorganic particles contained in the protrusion are exposed to a surface of the protrusion, and the binder resin is present among the inorganic particles contained in the protrusion. An elastic modulus E1 of the binder resin measured at a first region in a cross-section in a thickness direction of the elastic layer is equal to or above 1000 MPa.

Abstract: Provided an electrophotographic member capable of causing less fog in an H/H environment even when used in a torque-reduced image forming apparatus. The member comprises an electro-conductive substrate, an electro-conductive layer thereon and insulating parts, the member having a surface having an electrical insulating first region and an electro-conductive second region, the first region and the second region being adjacent to each other, a total area of the second region in a square region put on an outer surface of the member is 30% to 80% of an area of the square region; two or more of the 200 straight lines drawn in the square region at an interval of 5 ?m pass the second region at least once, and, the number of line segment LS having a length of 200 ?m or more is 5% or less of the total number of the line segment LS.

Abstract: An electrophotographic member includes an electro-conductive substrate and an elastic layer containing inorganic particles and a binder resin. The electrophotographic member has a protrusion on an outer surface of the electrophotographic member containing the inorganic particles, At least part of the inorganic particles contained in the protrusion are exposed to a surface of the protrusion, and the binder resin is present among the inorganic particles contained in the protrusion. An elastic modulus E1 of the binder resin measured at a first region in a cross-section in a thickness direction of the elastic layer is equal to or above 1000 MPa.

Abstract: An electrophotographic member includes an electro-conductive substrate, and an elastic layer as a surface layer, the elastic layer constituted by a single-layer, wherein the elastic layer includes a first resin, a second resin and an anion, the first resin is a crosslinked urethane resin, and the crosslinked urethane resin is a resin having a specific cationic structure in the molecule, the second resin is at least one of a crosslinked acrylic resin having an ether bond and a crosslinked epoxy resin having an ether bond, and in a first area of the elastic layer, the first are being from an outer surface of the elastic layer to a depth of 0.1 ?m, the first resin and the second resin form an interpenetrating polymer network structure.

Abstract: Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1?200 MPa and 10 MPa?E2?100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 ?m from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0×10?4 N.

Abstract: The electrophotographic member includes: an electroconductive substrate; and a surface layer having a mono-layer structure, wherein the surface layer has a matrix containing a cross-linked urethane resin as a binder, and when an elastic modulus of the matrix in a first region in a thickness direction from an outer surface of the surface layer to a depth of 0.1 ?m from the outer surface of the surface layer is defined as E1, and an elastic modulus of the matrix in a second region in a thickness direction from a depth of 1.0 ?m from the outer surface of the surface layer to 1.1 ?m from the outer surface of the surface layer is defined as E2, E1 and E2 satisfy the following Expressions (1) and (2), respectively: E1?200 MPa??(1); and 10 MPa?E2?100 MPa??(2).

Abstract: A developing roller that enables the image density of electrophotographic images to be kept uniform even when used in an environment at a high temperature and a high humidity for a long period. The developing roller includes an electro-conductive mandrel and an electro-conductive layer on the mandrel, having an outer surface constituted by at least a first region which is electrically insulating, and a second region, the second region having higher electro-conductivity than that of the first region, the first region being arranged adjacent to the second region, the first region being disposed on an outer surface of the electro-conductive layer, the first region having a Vickers hardness of 10.0 or more as measured at an outer surface thereof, and the first region having a fracture toughness value of 800 Pa·m0.5 or more as measured at the outer surface thereof by an indentation fracture method.

Abstract: A developing roller that enables the image density of electrophotographic images to be kept uniform even when used in an environment at a high temperature and a high humidity for a long period. The developing roller includes an electro-conductive mandrel and an electro-conductive layer on the mandrel, having an outer surface constituted by at least a first region which is electrically insulating, and a second region, the second region having higher electro-conductivity than that of the first region, the first region being arranged adjacent to the second region, the first region being disposed on an outer surface of the electro-conductive layer, the first region having a Vickers hardness of 10.0 or more as measured at an outer surface thereof, and the first region having a fracture toughness value of 800 Pa·m0.5 or more as measured at the outer surface thereof by an indentation fracture method.

Abstract: A developing roller is capable of preventing the generation of a difference in image density between a central portion and an end portion of an electrographic image. The developing roller has an electro-conductive mandrel and an electro-conductive layer on the mandrel, the electro-conductive layer has a crown shape in which an outer diameter of a central portion in a direction along the mandrel is larger than outer diameters of both end portions in the direction along the mandrel, an outer surface of the developing roller includes a first region having an electrically insulating property and a second region having a higher conductive property than the first region, and the first region and the second region are disposed adjacent to each other.

Abstract: Provided is an electrophotographic developing member capable of sufficiently increasing a density of an image initially output from a standby state. The developing member includes: a substrate; a porous electroconductive elastic layer on the substrate; and an electroconductive solid layer on the electroconductive elastic layer, in which an outer surface of the developing member includes a first region having an electrical insulating surface and a second region having an electroconductive surface, the first region and the second region are arranged to be adjacent to each other, and the first region is constituted by an electrical insulating portion disposed on an outer surface of the electroconductive solid layer.

Abstract: The electrophotographic member includes: an electroconductive substrate; and a surface layer having a mono-layer structure, wherein the surface layer has a matrix containing a cross-linked urethane resin as a binder, and when an elastic modulus of the matrix in a first region in a thickness direction from an outer surface of the surface layer to a depth of 0.1 ?m from the outer surface of the surface layer is defined as E1, and an elastic modulus of the matrix in a second region in a thickness direction from a depth of 1.0 ?m from the outer surface of the surface layer to 1.1 ?m from the outer surface of the surface layer is defined as E2, E1 and E2 satisfy the following Expressions (1) and (2), respectively: E1?200 MPa??(1); and 10 MPa?E2?100 MPa??(2).

Abstract: To provide a developing roller having improved toner conveying force in a high-temperature and high-humidity environment. The developing roller has a substrate and an electro-conductive layer on the substrate. The outer surface of the developing roller has an electrical insulating first region and an electro-conductive second region adjacent to the first region and at the same time has at least one groove in the first region.

Abstract: Provided is a developing member capable of sufficiently securing a toner conveyance amount, thereby being capable of suppressing a reduction in image density, even when a solid black image or an image having a high print percentage is continuously output. The developing member includes an electro-conductive substrate and an electro-conductive layer thereon, an outer surface of the developing member includes a first, second and third regions, when surface potentials of the respective regions with scanning probe microscope, and measured surface potential of the respective regions are defined as V1, V2, and V3, respectively, V1 is ?0.70 V to ?0.50 V, 1.30?V1/V2?25.00, and V3 is 0.00 V to 0.50 V.

Abstract: An electrophotographic member has an electro-conductive substrate, an elastic layer on the substrate and a coating layer on the elastic layer. The elastic layer has an elastic modulus of 0.5 MPa to 3.0 MPa and the coating layer has an elastic modulus of 5.0 MPa to 100.0 MPa as measured in an environment of a temperature of 30° C. and a relative humidity of 80%.

Abstract: Provided is a developing member capable of sufficiently securing a toner conveyance amount, thereby being capable of suppressing a reduction in image density, even when a solid black image or an image having a high print percentage is continuously output. The developing member includes an electro-conductive substrate and an electro-conductive layer thereon, an outer surface of the developing member includes a first, second and third regions, when surface potentials of the respective regions with scanning probe microscope, and measured surface potential of the respective regions are defined as V1, V2, and V3, respectively, V1 is ?0.70 V to ?0.50 V, 1.30?V1/V2?25.00, and V3 is 0.00 V to 0.50 V.