Patent ID: 7896633

Claim:
An expandable curing bladder for use in curing rubber products; the bladder comprising an inner layer and a calendered outer layer bonded to the inner layer, wherein the outer layer has a thickness ranging from about 0.025 to about 0.25 cm, and the inner layer is thicker than the outer layer; the inner layer comprising a rubber composition comprised of, based on parts weight per 100 parts by weight rubber (phr): an isobutylene copolymer rubber selected from butyl rubber and/or halobutyl rubber, wherein said butyl rubber comprises a copolymer of isobutylene and isoprene which contains from about 0.5 to about 5 weight percent units derived from isoprene; wherein said halobutyl rubber is a halogenated butyl rubber comprising a chlorinated or brominated copolymer of isobutylene and isoprene which contains from about 0.5 to about 5 weight percent units derived from isoprene; and the outer layer comprising a rubber composition comprising a silicone rubber; wherein said silicone rubber is formed from a composition comprising an organopolysiloxane containing at least 2 silicon-bonded alkenyl groups per molecule, an organohydrogenpolysiloxane having at least 2 silicon-bonded hydrogen atoms in each molecule, an inorganic filler, and a hydrosilylation catalyst.