Tokai Rubber Industries, Ltd.

Akitoshi Nozawa

Satoshi Suzuki

Hitoshi Yoshikawa

Keita Shiraki

Kunio Ito

Saburou Hayashi

Mitsuyoshi Kondo

An elastic member of a semiconductive polymer comprising a conductive composition containing a conductive polymer and binder polymer, wherein the elastic member satisfies both characteristics of (A) a variation of 1.5 digit or less between the electrical resistance at an applied voltage of 1V and the electrical resistance at an applied voltage of 133V under an environment of 25&#xb0; C. and 50% RH, and (B) a variation of one digit or less between the electrical resistance at an applied voltage of 10V under an environment of 15&#xb0; C. and 10% RH and the electrical resistance at an applied voltage of 10V under an environment of 35&#xb0; C. and 85% RH.

Elastic member of semiconductive polymer and OA equipment using the same

Electrically conductive foam component

A toner supply roll including a cylindrical soft polyurethane sponge structure formed on an outer circumferential surface of a metal shaft by foam molding of a polyurethane material in a mold cavity of a mold. The sponge structure having hardness of 350 g or lower includes a skin layer having a network of cells and openings open in its outer circumferential surface and communicating with respective ones of the cells located adjacent to the skin layer, such that the openings are substantially aligned with central portions of the respective ones of the cells in axial and circumferential directions of the sponge structure. Each opening has a size of 100-800 .mu.m, and a total area of the openings is at least 20% of the total surface area of the skin layer. The sponge structure has a plurality of protrusions formed on the outer circumferential surface of the skin layer so as to extend linearly or helically in the axial direction of the sponge structure. The protrusions have a height of 20-3000 .mu.m and are arranged in a circumferential direction of the sponge structure with a pitch of 300-3000 .mu.m, so that the skin layer is provided with recesses each interposed between the adjacent protrusions. Methods of producing the roll are also disclosed.

Toner supply roll including porous cylindrical polyurethane sponge

A toner supply roll including a metal shaft and a cylindrical soft polyurethane sponge structure formed on an outer circumferential surface of the metal shaft by foam molding of a polyurethane material in a mold cavity of a mold. The sponge structure having a hardness of 350 g or lower includes a skin layer having generally smooth surface and openings, and a network of cells. The openings are open in the smooth surface and communicate with respective ones of the cells located adjacent to the skin layer, such that the openings are substantially aligned with central portions of the respective ones of the cells in axial and radial directions of the sponge structure. Each opening has a size within a range of 100-800 .mu.m, and a total area of the openings is at least 20% of a total area of the smooth surface of the skin layer. The method of producing the roll is also disclosed.

Toner supply roll having openings in skin layer of porous cylindrical

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Komaki, Japan

Akitoshi Nozawa