| 摘要 |
PROBLEM TO BE SOLVED: To absorb the dispersion of a foaming cell diameter of a foaming layer and to obtain an excellent image by lowering the resistance of a non- foaming rubber layer laminated on the foaming layer. SOLUTION: An elastic layer 3 equipped with a 1st elastic layer 31 made of conductive foaming rubber and a 2nd elastic layer 32 made of conductive non-foaming rubber is formed on the outer periphery of a good conductive shaft 2, and further a surface layer 4 is formed on the elastic layer 3 as necessary. In such a case, 0.0001<=ρ2/√1<=1 andρ1=10<3> to 10<8>Ω.cm are satisfied when it is assumed that the volume specific resistance of the 1st elastic layer 31 isρ1 and that of the 2nd elastic layer 32 isρ2. The rubber foaming body having conductivity, which forms the 1st elastic layer 31, is the foaming elastic body obtained by adding conductive agent, foaming agent and cross linking agent to rubber material and cross-linking and foaming the rubber. Furthermore, the non-foaming rubber having the conductivity, which constitutes the 2nd elastic layer 32, is the elastic body obtained by adding the conductive agent and the cross linking agent to the rubber material and cross-linking the rubber. |
