| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing roll for electrophotographic equipment, the roll capable of suppressing variation in toner charging performance in a use environment ranging from low temperature and low humidity to high temperature and high humidity. <P>SOLUTION: The developing roll includes a surface layer formed of a resin composition as an outermost circumference of the roll. The resin composition contains a thermoplastic urethane resin having a glass transition temperature Tg of -20°C or lower, and a thermoplastic urethane resin having a glass transition temperature Tg of 60°C or higher. The resin composition has a tensile storage modulus E' satisfying conditions represented by (1): 5.0×10<SP POS="POST">7</SP>(Pa)≤E'(10)≤1.0×10<SP POS="POST">9</SP>(Pa) and (2): 5.0×10<SP POS="POST">7</SP>(Pa)≤E'(50)≤1.0×10<SP POS="POST">9</SP>(Pa), wherein E'(10) and E'(50) represent a tensile storage modulus at 10°C and 50°C, respectively. <P>COPYRIGHT: (C)2012,JPO&INPIT |
