| 摘要 |
PROBLEM TO BE SOLVED: To excellently adapt a rubber roll to an electrostatic recording device requiring various kinds of characteristics such as low hardness, medium resistance, high wet and surface smoothness by having a first layer made of polar rubber and a second layer made of a synthetic resin with specified thickness coated on the outer periphery of the first layer 1. SOLUTION: In a rubber roll, a first layer 9 made of polar rubber is formed in about 1 to 2 mm in thickness on a core bar 7 and a second layer 10 of a synthetic resin of a fluorine system, a silicon system and an urethane system is formed in about 10 to 100μm on the first layer 9. By providing the second layer 10 in this way, a resistance value changes under high wet environments of the first layer 9. But, when this roll is used for a developing roll, unnecessary toner is prevented from sticking on the surface of the roll and characteristics such as a toner surface lubricant, lubricity and toner chargeability can be improved. Further, when the second layer 10 is formed by dispersing low resistance particle 11 such as metal in a material of the second layer 10, the second layer 10 acts as a developing electrode and image quality can be improved. |
