| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing roll which does not cause unevenness in density, insufficient gradation or a ghost even when incorporated into a printer adaptable to high image quality. SOLUTION: The developing roll is obtained by forming a base rubber layer (innermost layer) 2 and a surface layer 3 in this order on the periphery of a shaft 1 and the base rubber layer 2 is formed using an electrically conductive material containing a quaternary ammonium salt of formula (1) as an ionic conductor. In the formula (1), R<1> -R<4> are each alkyl, at least one is different from the others, at least one is a 4-12C alkyl; X<n-> is an n-valent anion; and (n) is an integer of 1-6. |
