| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a conductive rubber composition for an electrophotographic apparatus, by which a volume resistivity can be lowered, and increase of the volume resistivity and bloom of an ion conductive agent during energization endurance when used for a charging roll are suppressed. <P>SOLUTION: A base layer 14 of a charging roll 10 is formed by using a conductive rubber composition which contains (a) a polar rubber having unsaturated linkage or ether linkage, (b) an ion conductive agent composed of one or plural kinds of phosphonium salts selected from a group represented by formula (1) and formula (2), and (c) a crosslinking agent, and in which (b) component is in a range of 0.1 to 10 pts.mass per 100 pts.mass of (a) component, where the formula (1) is [(H<SB POS="POST">9</SB>C<SB POS="POST">4</SB>)<SB POS="POST">3</SB>(C<SB POS="POST">n</SB>H<SB POS="POST">2n+1</SB>)P](CF<SB POS="POST">3</SB>SO<SB POS="POST">2</SB>)<SB POS="POST">2</SB>N, and the formula (2) is [(H<SB POS="POST">9</SB>C<SB POS="POST">4</SB>)<SB POS="POST">3</SB>(C<SB POS="POST">n</SB>H<SB POS="POST">2n+1</SB>)P](CF<SB POS="POST">3</SB>SO<SB POS="POST">3</SB>). <P>COPYRIGHT: (C)2012,JPO&INPIT |
