Patent ID: 6790926
Filing Date: 2004-09-14
Classification: C08G,D06M,Y10S

Abstract:
Non-porous, waterproof film having a water vapor permeability of at least 1000 g/m2 day in accordance with ASTM E96-66 (Procedure B), with the proviso that the water temperature is kept at 30Â° C., while the ambient temperature is 21Â° C. at 60% RH, comprising a thermoplastic polyurethane composed of a polyether glycol, a polyisocyanate, and a chain extender, at a ratio of NCO to active hydrogen atom of 0.9:1 to 1.2:1, wherein the polyurethane is a reaction product of a composition comprisinga) 40 to 52 wt. % of a total weight of the composition of polyalkylene oxide glycol having an average molecular weight of 800 to 4000 and an atomic ratio of carbon to oxygen in the range of 2.0:1 to 4.3:1, with the proviso that at least 30 wt. % of the polyurethane is composed of a polyether glycol having an atomic ratio of carbon to oxygen in the range of 2.0:1 to 2.4:1, b) 30 to 45 wt. % of the total weight of the composition of 4,4â€²-diphenyl methane diisocyanate, and c) 5 to 20 wt. % of the total weight of the composition of a combined amount of 1,4-butane diol and an araliphatic diol, both the 1,4-butane diol and the araliphatic diol being present in the composition, with the araliphatic diol comprising 0.5 to 10 wt. % of the total weight of the composition and having the formula wherein k=0 or 1, where if k=1, Y stands for a methylene or isopropylidene group, Q has the meaning of an H-atom or a CH3-group, C6X4 has the meaning of a phenylene group wherein X is hydrogen or a chlorine or bromine atom, and m and n is the same or different and stand for an integer&gE;1, with m+n&lE;10, wherein a) is not c).