Rubber member for use in electrophotographic apparatus and rubber member for separating paper sheets

摘要

The present invention provides an electrophotography rubber member which has a rebound resilience remaining satisfactorily stabilized over changes in environmental conditions and can serve as a member such as a high-performance cleaning blade and provides a similar sheet-separation rubber member which generates no noise. The electrophotography rubber member or sheet-separation rubber member is formed of a rubber elastomer containing a polyurethane formed from a long-chain polyol containing a polyester-polyol having a number average molecular weight of 500-5,000 and an ester concentration of 2-8 mmol/g, wherein the ester concentration is defined by the following relationship: Ester concentration (mmol/g)=(Amount by mol of ester groups)/(Weight of the polyester-polyol).