Patent ID: 7374816
Filing Date: 2008-05-20
Classification: C08L,C09D,D06N,E04D,Y10T

Abstract:
1. A prefabricated sealing membrane, having high stability to UV exposure and formed of a support or reinforcement, the support or reinforcement being one of coated on at least one surface and impregnated throughout, with a modified bitumen base composition, characterized in that the thermoplastic bituminous coating and or impregnation composition is a bituminous binder modified by a thermoplastic polyurethane having the following weight proportion: 60 to 80% bitumen, 15 to 40% thermoplastic polyurethane, 0 to 5% aromatic oil, 0 to 40% filler, 0 to 0.5% catalyst, the modified bituminous binder adapted to be softened by reheating and recover its properties after subsequent cooling, the prefabricated membrane being adapted for application by heating by torch welding or hot air, the prefabricated sealing membrane highly stable to UV exposure, wherein the thermoplastic polyurethane is obtained from a diisocyanate of a functionality substantially equal to 2, a polyol of functionality substantially equal to 2, and a chain elongation agent, the polyurethane molecules are free of double carbon-carbon bonds, and the polyols are free of ethylene linkages.