PURPOSE: To prevent fused toner from adhering onto a heat-fixing roll by a method wherein mixture of fluororubber dispersion and silicone oil is blended to silicone rubber stock.

CONSTITUTION: 0.1W100pts.wt. of mixture consisting in mixing fluororubber dispersion, which is prepared by dispersing fluororubber in water or organic solvent, with silicone oil is the ratio of 1/100W1/1 is incorporated to 100pts.wt. of silicone rubber by means of open mill rolls in order to uniformly knead. Said silicone rubber stock is tightly rolled onto a mandrel, on which bonding agent is applied, by means of cloth or the like and vulcanized. After the vulcanization, the surface of the rubber stock is finished by polishing. Thus, stainly toner, off-set phenomenon, both of which are produced by the adhesion of fused toner onto a heat-fixing roll at the fusion of toner image, can be prevented from producing.