developmental role

摘要

A developing roller has a core bar (12), an electrically conductive layer (14) formed on the circumferential surface of the core bar (12), and a covering layer (16) formed on the circumferential surface of the conductive layer (14). The covering layer (16) includes a reaction product produced by subjecting a reaction mixture containing a polyol, an isocyanate compound and a both-terminal reactive silicone oil to a reaction condition for them, and has a dynamic friction coefficient against paper of 0.9 or more and less than 1.2. IMAGE