Abstract: A medical rubber part in which non-elution characteristics are maintained even after sterilization with gamma ray, a packaging article for the medical rubber part, and a medical rubber composition for manufacturing the medical rubber part can be provided or implemented. The medical rubber composition can contain or comprise: a (a) base polymer containing a halogenated isobutylene-isoprene rubber; a (b) polyethylene; and a (c) triazine derivative as a crosslinking agent. A proportion of the triazine derivative contained per 100% by mole of a halogen of the halogenated isobutylene-isoprene rubber contained in the (a) base polymer can be 1% by mole to 15% by mole.

Abstract: A sterilization method for a medical rubber part in which non-elution characteristics can be maintained even after sterilization with gamma ray. The sterilization method for a medical rubber part can include irradiating, with gamma ray, a packaging article for a medical rubber part made from an elastomer that contains a polyethylene, the packaging article accommodating a plurality of the medical rubber parts.

Abstract: A developing roller is provided, which includes a roller body having a simplified structure without a coating film and yet having a higher wear resistance. The developing roller (1) includes a roller body (2) made of a crosslinked product of a rubber composition containing a rubber component including 20 to 50 parts by mass of ECO and/or GECO as an ion conductive rubber and 50 to 80 parts by mass of NBIR based on 100 parts by mass of the overall rubber component, and an oxide film (6) formed in an outer peripheral surface (5) of the roller body (2) by irradiation with ultraviolet radiation or the like.

Abstract: A developing roller is provided, which includes a roller body having a simplified structure without a coating film and yet having a higher wear resistance. The developing roller (1) includes a roller body (2) made of a crosslinked product of a rubber composition containing a rubber component including 20 to 50 parts by mass of ECO and/or GECO as an ion conductive rubber and 50 to 80 parts by mass of NBIR based on 100 parts by mass of the overall rubber component, and an oxide film (6) formed in an outer peripheral surface (5) of the roller body (2) by irradiation with ultraviolet radiation or the like.

Abstract: An inventive semiconductive roller includes a tubular semiconductive rubber layer (2) rotatable in a rotation direction, the semiconductive rubber layer having a multiplicity of minute projections (6) provided in circumferentially and axially discrete relation on an outer peripheral surface (5) thereof, the minute projections each having an apex (7) located forward (F) in the rotation direction and two edges (8,8) extending from the apex rearward (R) in the rotation direction obliquely with respect to the rotation direction so that the projections are each flared with a width (w) thereof progressively increasing in a rearward direction (R) from the apex (7) as measured axially of the semiconductive roller.

Abstract: A nonporous semiconductive roller is provided, which constantly ensures proper image formation substantially without image density unevenness attributable to the roughness of an outer peripheral extrusion surface thereof when being used as a developing roller. The semiconductive roller (1) is made of a nonporous crosslinking product of a rubber composition which contains a rubber component including only four types of rubbers including an epichlorohydrin rubber, a chloroprene rubber, a butadiene rubber and an acrylonitrile butadiene rubber.

Abstract: A semiconductive roller (1) is provided, which is formed from a rubber composition and has an outer peripheral surface (4) irradiated with electron radiation in a non-oxidizing atmosphere, wherein the rubber composition contains a rubber component including an epichlorohydrin rubber and a diene rubber, the epichlorohydrin rubber being present in a proportion of 50 mass % to 80 mass %, a thiourea crosslinking agent and/or a triazine crosslinking agent, and a sulfur crosslinking component.

Abstract: An electrically conductive rubber composition is provided, which is usable for production of a developing roller imparted with proper flexibility without the use of a softening agent without the formation of a shield layer and permits the developing roller to form an image substantially free from image unevenness due to permanent compressive deformation, banding, fogging and other defects. A developing roller employing the electrically conductive rubber composition is also provided. The electrically conductive rubber composition contains a rubber component including only four types of rubbers, i.e., an epichlorohydrin rubber, a butadiene rubber, a chloroprene rubber and an acrylonitrile butadiene rubber, and 0.75 to 2.25 parts by mass of sulfur, 0.25 to 1 part by mass of a thiuram accelerating agent, 0.75 to 2 parts by mass of a thiazole accelerating agent and 2.5 to 4.5 parts by mass of hydrotalcites based on 100 parts by mass of the overall rubber component.

Abstract: An electrically conductive rubber composition is provided, which is usable for production of a developing roller imparted with proper flexibility without the use of a softening agent without the formation of a shield layer and permits the developing roller to form an image substantially free from image forming defects such as banding and fogging. A developing roller employing the electrically conductive rubber composition is also provided. The electrically conductive rubber composition contains a rubber component including only four types of rubbers, i.e., an epichlorohydrin rubber, a butadiene rubber, a chloroprene rubber and an acrylonitrile butadiene rubber, and a crosslinking component including 0.75 to 2.25 parts by mass of sulfur and 0.25 to 0.75 parts by mass of a thiuram accelerating agent based on 100 parts by mass of the overall rubber component. The developing roller (1) is produced from the electrically conductive rubber composition.

Abstract: A semiconductive roller for use as a developing roller or the like is provided, which has an outer peripheral surface at least partly imparted with a reduced friction coefficient ? without irradiation with ultraviolet radiation. The semiconductive roller (1) includes a tubular body made of a crosslinking product of an electrically conductive rubber composition containing a crosslinkable rubber component, and a chloride film (5) formed in the outer peripheral surface (4) thereof through chlorination.

Abstract: A nonporous semiconductive roller is provided, which constantly ensures proper image formation substantially without image density unevenness attributable to the roughness of an outer peripheral extrusion surface thereof when being used as a developing roller. The semiconductive roller (1) is made of a nonporous crosslinking product of a rubber composition which contains a rubber component including only four types of rubbers including an epichlorohydrin rubber, a chloroprene rubber, a butadiene rubber and an acrylonitrile butadiene rubber.

Abstract: A semiconductive roller (1) is produced by: preparing a rubber composition containing a rubber component including an NBR and an EPDM in a mass ratio of NBR/EPDM=70/30 to 30/70, at least one selected from the group consisting of SAF, ISAF and HAF, sulfur, a peroxide crosslinking agent and a sulfenamide accelerating agent; extruding the rubber composition into a tubular body; crosslinking the tubular body in a vulcanization can or with the use of a continuous crosslinking apparatus; and forming an oxide film (5) in an outer peripheral surface (4) of the tubular body by irradiation with ultraviolet radiation with a shaft (3) inserted through the tubular body.

Abstract: A semiconductive roller (1) is provided, which is formed from a rubber composition and has an outer peripheral surface (4) irradiated with electron radiation in a non-oxidizing atmosphere, wherein the rubber composition contains a rubber component including an epichlorohydrin rubber and a diene rubber, the epichlorohydrin rubber being present in a proportion of 50 mass % to 80 mass %, a thiourea crosslinking agent and/or a triazine crosslinking agent, and a sulfur crosslinking component.

Abstract: A semiconductive roller for use as a developing roller or the like is provided, which has an outer peripheral surface at least partly imparted with a reduced friction coefficient ? without irradiation with ultraviolet radiation. The semiconductive roller (1) includes a tubular body made of a crosslinking product of an electrically conductive rubber composition containing a crosslinkable rubber component, and a chloride film (5) formed in the outer peripheral surface (4) thereof through chlorination.

Abstract: The semiconductive roller according to the present invention includes: a roller body having an outer peripheral surface made of a semiconductive rubber composition; and an oxide film covering the outer peripheral surface of the roller body, while the semiconductive rubber composition contains a base polymer and a crosslinking component for crosslinking the base polymer, the base polymer is a mixture of a bicopolymer E containing epichlorohydrin and nitrile-butadiene rubber N, the mass ratio E/N of the bicopolymer E and the nitrile-butadiene rubber N in the mixture is 50/50 to 80/20, and the crosslinking component includes a thiourea-based crosslinking component for crosslinking the bicopolymer E and a sulfur-based vulcanizing component for vulcanizing the nitrile-butadiene rubber N.

Abstract: An inventive semiconductive roller includes a tubular semiconductive rubber layer (2) rotatable in a rotation direction, the semiconductive rubber layer having a multiplicity of minute projections (6) provided in circumferentially and axially discrete relation on an outer peripheral surface (5) thereof, the minute projections each having an apex (7) located forward (F) in the rotation direction and two edges (8,8) extending from the apex rearward (R) in the rotation direction obliquely with respect to the rotation direction so that the projections are each flared with a width (w) thereof progressively increasing in a rearward direction (R) from the apex (7) as measured axially of the semiconductive roller.

Abstract: A semiconductive roller (1) is produced by: preparing a rubber composition containing a rubber component including an NBR and an EPDM in a mass ratio of NBR/EPDM=70/30 to 30/70, at least one selected from the group consisting of SAF, ISAF and HAF, sulfur, a peroxide crosslinking agent and a sulfenamide accelerating agent; extruding the rubber composition into a tubular body; crosslinking the tubular body in a vulcanization can or with the use of a continuous crosslinking apparatus; and forming an oxide film (5) in an outer peripheral surface (4) of the tubular body by irradiation with ultraviolet radiation with a shaft (3) inserted through the tubular body.

Abstract: The electrically conductive rubber composition contains a rubber component including an SBR, an epichlorohydrin rubber and a CR, and the proportion of the SBR is 40 to 80 parts by mass based on 100 parts by mass of the rubber component. The rubber composition further contains 1.0 to 1.5 parts by mass of a sulfur crosslinking agent, 0.2 to 0.6 parts by mass of a thiourea accelerating agent, 0.1 to 0.5 parts by mass of a thiuram accelerating agent, and 1.0 to 2.0 parts by mass of a thiazole accelerating agent based on 100 parts by mass of the rubber component.

Abstract: The semiconductive roller according to the present invention includes: a roller body having an outer peripheral surface made of a semiconductive rubber composition; and an oxide film covering the outer peripheral surface of the roller body, while the semiconductive rubber composition contains a base polymer and a crosslinking component for crosslinking the base polymer, the base polymer is a mixture of a bicopolymer E containing epichlorohydrin and nitrile-butadiene rubber N, the mass ratio E/N of the bicopolymer E and the nitrile-butadiene rubber N in the mixture is 50/50 to 80/20, and the crosslinking component includes a thiourea-based crosslinking component for crosslinking the bicopolymer E and a sulfur-based vulcanizing component for vulcanizing the nitrile-butadiene rubber N.

Abstract: A semiconductive roller having good semiconductivity as a charging roller or a developing roller is described. The semiconductive roller includes an oxide film having excellent characteristics as a protective film, and in particular, hardly causes an image defect of white stripes associated with tackiness in an image formed in a storage test in an environment of high temperature and high humidity. The semiconductive roller includes a semiconductive rubber composition formed by mixing a base polymer with a triazine crosslinker and a sulfur-based crosslinking component as a crosslinking component for crosslinking the base polymer, wherein the base polymer is a mixture of an epichlorohydrin rubber E and a diene rubber D having a mass ratio of E/D of 50/50 to 80/20. The semiconductive roller also has an oxide film formed on its outer peripheral surface by ultraviolet irradiation.