Patent ID: 9026014
Filing Date: 2015-05-05
Classification: F16C,G03G,Y10T

Abstract:
1. A developing roller comprising successively on an outer periphery of a shaft an elastic layer, an intermediate layer, and a surface layer wherein said surface layer contains a urethane (meth)acrylate oligomer obtained by allowing a polybutadiene polyol or a hydrogenated polybutadiene polyol, a polyisocyanate, and a (meth)acrylate having a hydroxyl group to react, and said intermediate layer contains 1 part by mass or more of carbon black with respect to 100 parts by mass of an ultraviolet curable resin, and wherein when a surface of said elastic layer is electrified by corona discharge at 8 kV from a position 1 mm away from the surface under conditions at a temperature of 32.5° C. and at a humidity of 80% RH, a surface potential 0.4 seconds thereafter is 25 V or higher.