Sumitomo Riko Company Limited

Kuniaki Doi

Yuma Yoshida

Atsuhiro Kawano

Satoshi Suzuki

A paper feed roller including an elastic layer composed of thermosetting polyurethane containing a plasticizer, wherein an amount of the plasticizer is within a range of 10 to 50 pts. mass based on 100 pts. mass of the thermosetting polyurethane, and a surface residual charge on the elastic layer is within a range of 90 to 170 V. The surface residual charge is a value determined by single-point measurement of a surface potential of the elastic layer. The measurement includes rotating the paper feed roller in a circumferential direction, electrifying the surface of the elastic layer with a corotron while rotating the paper feed roller, and measuring the surface potential at a center point on the paper feed roller in a roller axis direction in a position where the paper feed roller is rotated by 90 degrees from a position where the surface of the elastic layer is electrified.

Paper feed roller

A paper feed rolleris used in a paper feeding unit in an electrophotographic image forming device. The paper feed rollerincludes a non-foamed elastic bodyhaving an embossed surfaceincluding crest-like partsand valley-like parts. The embossed surfacehas many dimple partsrecessed inward on bottom surfaces of the valley-like partsor on the bottom surfaces and lateral surfaces of the valley-like parts, and does not have the many dimple partson top parts of the crest-like parts. A diameter of the dimple partscan be set to be 1 to 100 &#x3bc;m and an arithmetic average height Ra of the embossed surfaceto be 3 to 50 &#x3bc;m.

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Susono, Japan

Kuniaki Doi