| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing roll of low hardness which improves image quality by suppressing outside diameter change of a roll and shape change of a roll surface to a minimum. SOLUTION: In the developing roll 20 having an elastic foamed body layer 2 around a core axis 1, an elastic nonfoamed body layer 3 is integrally provided at an outer peripheral part 2a and an end part 2b of the elastic foamed body layer 2 so as to be adjacent to them. Polymer constituting the elastic nonfoamed body layer 3 is preferably epichlorohydrin rubber or nitrile rubber. In the polymer constituting the elastic nonfoamed body layer 3, a liquid polymer having the same repetitive units as the polymer is preferably dispersed as a plasticizer in a noncrosslinked state. The elastic nonfoamed body layer 3 preferably contains an inorganic filler of >=50 volume %. Average grain size of the inorganic filler is preferably <=3μm. |
