Bridgestone Corporation

Satoru Kusano

Junichiro Sato

Katsuya Seki

Youhei Takeda

Masaru Otsuka

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

The present invention provides a toner transfer roller which exhibits decreased toner charge (Q/M) and an enhanced toner transfer rate (M/A). Specifically, the present invention provides: a toner transfer roller for a negatively chargeable toner, comprising a rotating shaft and a polyurethane foam body layer provided to surround the rotating shaft, wherein the polyurethane foam body layer contains a charge control agent which is negatively chargeable with respect to polyurethane in triboelectric series; and a toner transfer roller for a positively chargeable toner, comprising said rotating shaft and said polyurethane foam body layer, wherein said polyurethane foam body layer contains a charge control agent which is positively chargeable with respect to polyurethane in triboelectric series.

Toner transfer roller and image forming device using the same

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.

Charge-controlled polyurethane foam and toner-conveying roller using the same

The invention provides a toner supply and cleaning roller that secures sufficient density especially at an initial stage of printing, and an image forming apparatus using the same. The toner supply and cleaning roller has a shaft () and an electroconductive elastic layer () made of a urethane foam and supported on the circumference of the shaft () by means of an adhesive layer () in between. The resistance of the roller at an applied voltage of 100 V is 10&#x3a9; or lower, preferably 10&#x3a9; or lower, and the resistance of the roller at an applied voltage of 5 V is 10to 10&#x3a9;. The adhesive layer () contains a hot-melting polymeric adhesive and is formed preferably at a temperature not exceeding the melting point of the hot-melting polymeric adhesive.

Toner supply and cleaning roller comprising electroconductive elastic layer supported by means of adhesive layer and image forming apparatus using the same

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Yokohama, Japan

Satoru Kusano