| abstract |
A process for curing a heat-weldable roofing membrane by applying elemental sulfur on the exterior surface of the roofing membrane, said membrane being a blend of (a) 50-80% by weight of an ethylene/propylene/nonconjugated diene elastomer and (b) 20-50% by weight of an ethylene-containing polymer selected from the group consisting of polyethylene, an ethylene alpha-monoolefin copolymer wherein the monoolefin contains from 3-12 carbon atoms and is present in amounts of 2-8% by weight, and an ethylene/vinyl acetate copolymer having a vinyl acetate content up to about 10% by weight, said membrane containing a cure accelerator. The roofing membrane is exposed to ambient outdoor temperatures resulting in migration of sulfur to the interior of the membrane where, together with the cure accelerator, it effects cure of the membrane. |