Bridgestone Corporation

Youhei Takeda

Katsuya Seki

Junichiro Sato

Satoru Kusano

Masaru Otsuka

Tomohiro Yamamoto

Provided are urethane foam: which heightens toner charge amount (Q/M); by which toner is sufficiently absorbed in the surface layer of a toner-conveying roller to give a sufficient toner conveying ability; and by which a good image can be obtained with a low cost, and a toner-conveying roller using the same. Also provided are urethane foam in which substrate urethane foam is impregnated with one or more powders selected from the group consisting of silicone powder and silica powder, and a toner-conveying roller using the same. Preferred are urethane foam wherein said powder is bound with said substrate urethane foam via a binder, and a toner-conveying roller using the same.

Urethane foam and toner-conveying roller using the same

A sealing material is provided, which maintains excellent sealing property for a long period of time. The sealing material of the invention is characterized by being prepared by vulcanizing and foaming a mixture containing a rubber component containing a copolymer rubber of ethylene, an &#x3b1;-olefin having 3 or more carbon atoms, and a non-conjugated diene, a vulcanizing agent, and a blowing agent, wherein the mixture contains a thermoplastic resin having a melting point of 80&#xb0; C. or less.

Sealing material

Provided are charge-controlled polyurethane foam by which the influence of electrification by friction between toner on the surface layer of a toner-conveying roller and a developing roller can be sufficiently prevented and by which a good image can be stably obtained with a low cost, and a toner-conveying roller using the same. The charge-controlled polyurethane foam is the one wherein the surface layer of the polyurethane foam is impregnated with a charge control agent which is on the negative side or on the positive side in the triboelectric series with respect to substrate polyurethane foam. The toner-conveying roller is the one which supports the charge-controlled polyurethane foam on the periphery of the axis of the roller.

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Yokohama, Japan

Youhei Takeda