Improved butyl rubber compositions.

摘要

A new rubber composition, the vulcanizate of which has reduced permeability to gases, comprises: from about 70 to about 90 parts by weight of a high molecular weight butyl-type rubbery polymer; from about 10 to about 30 parts by weight of a low molecular weight butyl-type rubber polymer, wherein the total amount of polymers described above is one hundred parts by weight; from about 30 to about 90 parts by weight of at least one carbon black; and a curing system.