| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a developing roller capable of restraining occurrence of binding even when images are output at a high speed for a long period of time and capable of restraining initial fixing of toner and fusion of toner when image output is carried out repeatedly at a low temperature and a low humidity. <P>SOLUTION: In the developing roller having a shaft core body and at least one resin layer provided around the shaft core body, the outermost layer of the developing roller contains a polyurethane resin (A) as a binding resin for forming a continuous layer and polyurethane resin particles (B) dispersed in the polyurethane resin (A). If the loss tangents (tanδ) of the polyurethane resin (A) and polyurethane resin particles (B), obtained at a measurement temperature T(T=-20°C to 40°C) and at a frequency of 10 Hz are defined as tanδ(A) and tanδ(B) respectively, the developing roller satisfies the following expressions: (1) 0.40≤tanδ(B)≤1.10 and (2) 0.30≤tanδ(B)-tanδ(A)≤0.70. <P>COPYRIGHT: (C)2012,JPO&INPIT |
