Canon Kabushiki Kaisha

Masashi Uno

Ryo Sugiyama

Kenta Matsunaga

Kazuaki Nagaoka

Fumihiko Utsuno

Hideya Arimura

Tomoya Uesugi

Yoshinobu Ogawa

Masaki Yamada

Minoru Nakamura

Toru Ishii

Tsunenori Ashibe

Wataru Moriai

Takashi Kusaba

Hiroaki Komatsu

Shohei Urushihara

Provided is an electrophotographic member in which the increase in tackiness is small even in an environment of high temperature and high humidity. The electrophotographic member includes an electroconductive substrate and a surface layer, the surface layer contains resin including at least one of a urethane bond and an amide bond, the resin includes a cationic structure and an anionic structure in a molecule, and also includes a particular main-chain structure with hydrophobicity.

Electrophotographic member, process cartridge, and electrophotographic apparatus

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 &#x3bc;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 &#x3bc;m from the outer surface of the surface layer to 1.1 &#x3bc;m from the outer surface of the surface layer is defined as E2, E1 and E2 satisfy the following Expressions (1) and (2), respectively:1&#x2265;200 MPa&#x2003;&#x2003;(1); and10 MPa&#x2264;2&#x2264;100 MPa&#x2003;&#x2003;(2).

Electrophotographic member having a surface layer with a cross-linked urethane resin-containing matrix, process cartridge, and apparatus

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&#xb7;mor more as measured at the outer surface thereof by an indentation fracture method.

Developing roller, process cartridge and electrophotographic image forming apparatus

A developing roller that suppresses contamination of the surface of a photosensitive member and also obtains a high-quality image. The developing roller includes an electro-conductive substrate, an electro-conductive elastic layer and a surface layer which are stacked in this order, wherein the surface layer has resin particles that are dispersed in a polyurethane matrix, an outer surface of the surface layer has a first protrusion originating in first resin particle and a second protrusion originating in second resin particle, wherein the first resin particle contains polyurethane, an elastic modulus Eof the first resin particle is 100 to 2000 MPa, an elastic modulus Eof the second resin particle is 2 to 50 MPa, a maximum height roughness Rz of the outer surface is 6 to 18 &#x3bc;m, and a peak vertex density Spd is 5.0&#xd7;10to 5.0&#xd7;10(1/mm).

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.

Developing roller having crown-shaped electro-conductive layer with outer surface providing electrically insulating first regions adjacent to second regions having higher conductivity

Provided is a developing roller including elastic layer and resin layer adhered to each other and having an appropriately resistance, thereby suppressing fogging. The developing member comprises a mandrel; an elastic layer; and a resin layer, wherein: the resin layer comprises polyurethane resin obtained by isocyanate and polyol; and the elastic layer includes cured silicone rubber composition comprising (a)-(d): 

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Mishima, Japan

Masashi Uno