| 摘要 |
PROBLEM TO BE SOLVED: To provide a development roller having uniform electric characteristics, sufficient charging capability, low resistance applicable to a high-speed electrophotographic apparatus, uniform electric characteristics even after use in a long period, also having excellent resistance stability, by which high-quality image by uniform charge friction of developer can be formed even under low temperature, which is excellent in antifog property, and to provide an electrophotographic process cartridge and an electrophotographic image forming apparatus. SOLUTION: In the development roller for electrophotography having an elastic layer on a conductive cored bar, the elastic layer contains rubber components containing ethylene-propylene-diene terpolymer of 80 mass% or more and hydrocarbon based plasticizer within a range of 30 to 70 mass%, the hydrocarbon based plasticizer has a flow point at temperature of -50°C or higher and -10°C or lower and the elastic layer has a value of tanδof dynamic viscoelasticity at frequency of 0.1 Hz and measuring temperature of -10°C larger than 0.10 and smaller than 0.90. COPYRIGHT: (C)2007,JPO&INPIT |
