PROCESS FOR PRODUCING CONDUCTIVE RUBBER ROLLER AND ROLLER FOR ELECTROPHOTOGRAPHIC APPARATUS

摘要

A process for producing a conductive rubber roller which has a low aspect ratio of the inner/outer diameter, stable inner-diameter dimension, and even cell distribution and is free from hardness unevenness and resistance unevenness in the peripheral direction. The process comprises: an extrusion step in which a tube of a specific unvulcanized rubber composition is continuously extruded from a rubber extruder in a microwave vulcanizer; and a step in which the unvulcanized-rubber composition tube, while being conveyed at a given rate, is foamed/vulcanized and molded with a microwave irradiation apparatus having a microwave irradiation region with a length of 4 m or shorter. The inner diameter of the foamed rubber tube thus molded through foaming/vulcanization is smaller by 20-35% than the outer diameter of the conductive core material throughout the lengthwise direction of the conductive rubber roller. The conductive core material is forced into the foamed rubber tube without using an adhesive.