Patent ID: 7544158

Claim:
An electroconductive rubber roller comprising: an electroconductive metal core; and an electroconductive crosslinked rubber layer including an epichlorohydrin-based rubber and provided on the electroconductive metal core; wherein the epichlorohydrin-based rubber is at least one copolymer selected from the group consisting of an epichlorohydrin-ethylene oxide copolymer and an epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer; the ethylene oxide unit in the epichlorohydrin-based rubber is in a content of 40 to 90 mol % based on the epichlorohydrin-based rubber; and the electroconductive crosslinked rubber layer has a heat quantity (enthalpy: DH) of 5 mJ/mg or less as measured by a differential scanning calorimetry (DSC) and indicated by a peak appearing within a range of −20 to 150° C.