Sumitomo Rubber Industries Limited

Kei Tajima

Yoshihisa Mizumoto

Takashi Marui

Hideyuki Okuyama

Kenichi Kuroda

Yuta Imase

Noriaki Hitomi

Akira Minagoshi

Kiyotaka Okuda

Akira Kamigoro

Yasufumi Kozono

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 () includes a roller body () 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 () formed in an outer peripheral surface () of the roller body () by irradiation with ultraviolet radiation or the like.

Developing roller including roller body with simplified structure without a coating film

An inventive semiconductive roller includes a tubular semiconductive rubber layer () rotatable in a rotation direction, the semiconductive rubber layer having a multiplicity of minute projections () provided in circumferentially and axially discrete relation on an outer peripheral surface () thereof, the minute projections each having an apex () located forward (F) in the rotation direction and two edges () 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 () as measured axially of the semiconductive roller.

Semiconductive roller

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 () 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.

Semiconductive roller for image developing roller

A semiconductive roller () is provided, which is formed from a rubber composition and has an outer peripheral surface () 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.

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 &#x3bc; without irradiation with ultraviolet radiation. The semiconductive roller () includes a tubular body made of a crosslinking product of an electrically conductive rubber composition containing a crosslinkable rubber component, and a chloride film () formed in the outer peripheral surface () thereof through chlorination.

A semiconductive roller () 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 () in an outer peripheral surface () of the tubular body by irradiation with ultraviolet radiation with a shaft () inserted through the tubular body.

Semiconductive roller and production method therefor

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.

Semiconductive roller, charging roller and electrophotographic apparatus

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.

Electrically conductive rubber composition, developing roller, and image forming apparatus

The semiconductive rubber composition according to the present invention contains: a rubber content containing at least copolymer rubber containing ethylene oxide as a copolymeric component and chloroprene rubber; and not less than 0.5 parts by mass and not more than 1.5 parts by mass of a thiourea-based vulcanization accelerator, not less than 0.5 parts by mass and not more than 1.5 parts by mass of a guanidine-based vulcanization accelerator and not less than 0.5 parts by mass and not more than 2.0 parts by mass of a peroxide-based crosslinking agent with respect to 100 parts by mass of the sum of the rubber content.

Semiconductive rubber composition and semiconductive rubber roller employing the same

A conductive thermoplastic elastomer composition comprising a component (A) containing a thermoplastic resin or/and a thermoplastic elastomer; a component (B) comprising an ionic-conductive agent containing an ethylene oxide-propylene oxide copolymer or/and an ethylene oxide-propylene oxide-allyl glycidyl ether copolymer and a metal salt contained in the ethylene oxide-propylene oxide copolymer or/and the ethylene oxide-propylene oxide-allyl glycidyl ether copolymer; and a component (C) comprising an ethylene-acrylic ester-maleic anhydride copolymer.

Conductive thermoplastic elastomer composition, method of producing same, and molding

A rubber component containing at least one of diene rubber and ethylene-propylene-diene rubber is dynamically crosslinked. Thereby the rubber component is dispersed in a mixture of a thermoplastic elastomer and a thermoplastic resin. An ethylene oxide-propylene oxide-allyl glycidyl ether and an anion-containing salt having fluoro groups and sulfonyl groups are added to the elastomer composition to obtain a conductive dynamically crosslinked thermoplastic elastomer composition. A mixture of the obtained conductive dynamically crosslinked thermoplastic elastomer composition and a micro-capsule composed of a polymer, having acrylic groups, which forms an outer shell thereof is molded to obtain a conductive roller having Shore A hardness specified in JIS K6253 not more than 40 measured at 23&#xb0; C.

Conductive roller of rubber, thermoplastics, EO-PO-glycidyl ether, fluoro and sulfonyl anion salt and microcapsule

A fender for absorbing the impact of a vessel is provided, which is formed of rubber and fixed to a fixing surface of a dock and adapted to have an impact receiving plate secured to a distal end of a body of the fender. The fender comprises a first bumper member having an elongated hollow cylindrical body of a constant outside diameter and affixed to the impact receiving plate at one end, and a second bumper member connected at one end to an opposite end of the cylindrical body of the first bumper member. The second bumper member at the opposite end thereof is fixed to the fixing surface at a portion having a hollow conical body with its distal end being greater in outside diameter than its closest end, and the second bumper member buckling radially outwardly upon receiving a compressive force from the vessel thereby absorbing the impact of the vessel; and a shoulder formed along an outer periphery of a connection portion between the first and second bumper members.

Fender with step and/or projection

The present invention provides a novel fender, which has a sufficient shock absorbing action with respect to a ship and is capable of dispersing a compressive force given at the time when the ship comes alongside at the pier and reducing a friction force at the time given when the ship is moored at the pier. A fender of the present invention comprises a fender body,, and a surface layer,with which at least an impact receiving surface of this fender body,is coated, wherein the surface layer,is made of a blended polymer of a crystalline polyolefin resin and a diene rubber and the proportion of the crystalline polyolefin resin in the blended polymer exceeds 50% by weight and not more than 85% by weight.

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Kobe, Japan

Kei Tajima