Patent ID: 6951688

Claim:
A charging member for charging a surface of a member to be charged in an image-forming apparatus under application of a voltage, the charging member having an outermost surface layer containing a conductive elastic material, wherein said conductive elastic material comprises a polymer, and at least 70% by weight based on the total weight of the polymer is a polar polymer, wherein said polar polymer primarily comprises: (i) acrylonitrile butadiene rubber; (ii) an ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer; and (iii) a homopolymer of epichlorohydrin, and wherein weights x, y and z of the components (i), (ii) and (iii), respectively, have a relationship represented by the following expressions (1) and (2): 0.2≦ y/ ( x+y+z )≦0.5 (1) 4< y/z≦ 20 (2).