Sumitomo Rubber Industries Limited

Sumio Gomu Kogyo Kabushiki Kaisha

Hitoshi Itani

Hirotoshi Murakami

Shunichi Yabushita

Yuji Yamasaki

Hiroaki Tanaka

Soichiro Kozuka

Masahiro Tanigawa

Yasuchika Itoh

An elastic roller contains EPDM rubber as a main component and has a friction coefficient of not less than 2 with respect to ordinary paper and a hardness of not more than 35.degree.. The amount of softening agent added to EPDM rubber which is a main component is not more than 150 parts by weight per 100 parts by weight of rubber.

Elastic roller

An electrically conductive rubber roller for electrophotography which does not exhibit touch memory or bleed out of remnant siloxanes, even after 18 days of storage without use, and, in a preferred form, exhibits little change in electric resistance with changes in environment. This roller is made by making a rubber molding material composition containing a raw polysiloxane rubber which does not contain more than 5,000 ppm of low molecular weight polysiloxanes, cyclic siloxanes and non-functional silicone oils (remnant siloxanes); molding this composition into a roller; at least primarily crosslinking the rubber in the roller; and then subjecting the crosslinked rubber roller to heating under a vacuum.

Silicone rubber roller for electrophotography and method of producing

An apparatus feed paper sheets to a photosensitive dram of an electronic copier, negatively charged toner adhering the dram. The apparatus incorporates a paper feed roller and a rubber member located adjacent the roller for supporting paper sheets in contacting relation to the roller. The robber member has a polymer, vulcanizer, vulcanization aid and filler; and at least one component selected from the group consisting of magnesium oxide, barium oxide, nylon short fibers, powder of nylon short fibers and nigrosine compound. The component is present in an amount of 1 to 100 parts by weight to 100 parts by weight of the polymer. The paper sheet becomes electrostatically charged negatively, when contacting the rubber member during sheet feeding by the roller, thus preventing electrostatic attraction between the paper approaching the dram and negatively charged toner on the dram.

Rubber member for paper feed device

There is disclosed an electrically conductive rubber roller for electrophotography which changes very little in electric resistance with changes in environment. This roller is used for charging and image transferring processes in copying machines and laser beam printers. The roller comprises a porous body of crosslinking silicone composition, containing at least a silica type filler, carbon black a foaming agent and siloxane polymer; the composition has an electric resistance of 10.sup.3 -10.sup.8.

The invention provides an electrically conductive rubber material for use in an electrophotographic copying apparatus of a composition which will prevent bleeding and blooming so as to obtain a image of high quality. The electrically conductive rubber material comprises a diene type rubber and a rubber which contains no double bond in its principal chain, which rubber is cross-linked with a metallic salt cross-linking agent. A portion of the diene type rubber butadiene rubber in a proportion to the total parts by weight of rubber of 10-30 parts by weight. The proportion of the rubber containing no double bond in its principal chain to the total parts by weight of rubber is not less than 15 parts by weights. 5-100 parts by weight of carbon black per 100 parts by weight of rubber are added to serve as an electrical conductivity imparting agent. Not more than 3 parts by weight of oil ingredient, use as a softening agent, plasticizer and the like, per 100 parts by weight of rubber as measured by solvent extraction by acetone is also permitted. Preferably, the rubber containing no double bond in its principal chain is EPDM rubber.

Electrically conductive rubber material used for electrophotographic

It is intended to suppress the production of 'creak' during paper feed. A support block having a friction rubber element mounted thereon to be rubbed by paper sheets is made of a resin compound having a specific gravity of 2.0 or more containing metal powder.

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Kobe, Japan

Hitoshi Itani