| abstract |
An improved rubber composition for use in articles requiring reduced permeability to air, comprises: none hundred parts by weight of a terpolymer of isobutylene, isoprene and α-methylstyrene, nfrom about 30 to about 90 parts by weight of at least one carbon black, and na curing system, nwherein the terpolymer comprises from about 0.5 to about 2 mole percent of isoprene, from about 2 to about 7 mole percent of α-methylstyrene and from about 91 to about 97.5 mole percent of isobutylene. |