Dynamically cured thermoplastic olefin polymers

Abstract From the Canadian patent

Thermoplastic compositions of matter useful as gasketing materials as well as flexible boots and seals which are soft, have low compression set and high tensile. The compositions comprise a polyolefin resin and at least two different rubbers, one of which is vulcanized to a fully cured state by a cure system which leaves the other rubber(s) unvulcanized. The preferred embodiment comprises a blend of polypropylene and ethylene vinylacetate as the polyolefin resin component EPDM as the uncured rubber component and a ZnO cured halogenated butyl rubber. In another embodiment of the invention, the resin is excluded and the uncured rubber is a high crystallinity EPDM.