Abstract: The invention provides a novel semiconductive silicone rubber roller suitable for use as a development roller in a photocopying machine exhibiting high performance with stability and long durability. The rubber roller is prepared by (A) forming a cylindrical layer of a semi-conductive silicone rubber on and around a metallic core mandrel, (B) irradiating the surface of the rubber layer with ultraviolet light and (C) coating the ultraviolet-irradiated surface of the rubber layer with a silane coupling agent.

Abstract: Disclosed is an improvement in a rubber roller as a developing roller in a electrophotographic printer of which the silicone rubber forming the rubber layer on and around a metallic core mandrel is electrically semiconductive. The printing characteristics and abrasion resistance of the rubber roller to ensure good durability of the rubber roller in printing services can be greatly improved by the irradiation treatment of the rubber surface with ultraviolet light having principal wavelengths of 253.7 nm and 184.9 nm in an irradiation dose of 1.2 to 76 J/cm.sup.2, preferably, in an oxygen-containing atmosphere to form an ultraviolet-hardened surface layer of which the rubber surface has a specified surface rough-ness.