Silicone rubber-covered copier roll

Claim 1

In a silicone rubber-covered roll for use in an electrophotographic copier, said roll comprising a roll axle and a layer of silicone rubber obtained by curing a composition comprising (A) 100 parts by weight of an organopolysiloxane having at least 2 silicon-bonded lower alkenyl radicals in each molecule; (B) an organohydrogensiloxane wherein each molecule contains at least two silicon-bonded hydrogen atoms, and the amount of said organohydrogensiloxane is equivalent to a molar ratio of silicon-bonded hydrogen atoms in (B) to lower alkenyl radicals in (A) of from 0.5 to 20; and (C) a platinum-containing catalyst in a quantity providing 0.1 to 500 parts by weight of platinum metal for each 1 million weight parts of the total quantity of components (A) and (B), the improvement characterized by (1) selecting said cured silicone rubber from those exhibiting a hardness value in the range of from 10 to 70 measured on the A scale in accordance with Japanese Industrial Standard C 2123 and a compression set of 10% or less, and (2) selecting said organohydrogensiloxane from organosiloxane copolymers comprising R 3 SiO 1/2 units, R 2 SiO units, RHSiO units, and RSiO 3/2 units, where each R is individually selected from monovalent hydrocarbon or halogenated hydrocarbon radicals free of ethylenic unsaturation, and where from 0.5 to 50 mol % of said copolymer consists of RSiO 3/2 units.