| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing roller that has low hardness and set performance, less bled substance, and appropriate and uniform conductivity. <P>SOLUTION: In the developing roller having a shaft core body 11 and an elastic layer 12 and a coating layer 13 laid in that order on the external circumferential surface of the shaft core body 11, the elastic layer 12 contains a cross-linked product of conjugated diene polymer, a polybutadiene compound with a mass average molecular weight of 3000 or more but 7000 or less, and carbon black, and a chemical bond is formed between the cross-linking product of the conjugated diene polymer and the carbon black. The elastic layer 12 of the developing roller 1 is formed in such a manner that an uncross-linked rubber composition is prepared by mixing modified conjugated diene polymer obtained by selecting and coupling at least one of tin atom, nitrogen atom, and silicon atom, the polybutadiene compound, and carbon black, and the uncross-linking rubber composition is formed on the external circumferential surface of the shaft core body 11 and heated and cured. <P>COPYRIGHT: (C)2012,JPO&INPIT |
