| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductive silicone rubber roll which keeps initial characteristics for a long time. SOLUTION: A semiconductive silicone rubber roll 4 is prepared by forming a surface coating layer 3 containing synthetic resin and conductive grains on an outer peripheral surface of a conductive shaft body 1 through a semiconductive elastic layer 3 made of silicone rubber. The conductive grains contained in the surface coating layer 3 are positively electrified, while having the conduction ratioεranging between 2.0 and 8.0. The following formulae are to be satisfied, -0.01 <=r1-r0<=0; 0.5<=RZ1/RZ0<=2; 0.1<=R1/R0<=10; 0.5<=T1/T0<=2.5 where (r) denotes an outer diameter of the rubber roll (mm), Rz denotes surface roughness, R denotes resistance (Ω). An initial value and the value after long usage of toner electrified rate (μC/g) are represented by respectively adding 0 and 1. |
