Patent ID: RE43432

Claim:
A single component polyurethane foam forming composition comprising a mixture of (a) prepolymers containing free isocyanate groups in the range of 12 to 17 percent by weight, based on the weight of the prepolymer, which is produced by reacting a polyisocyanate with a polyol blend comprising a first polyol that is a triol having a molecular weight of in the range of from 500 to 3000 600 to 2,500 and a second polyol that is a diol, triol or a mixture mixtures thereof having a molecular weight in the range of from 4,000 to 12,000 6,000 to 10,000, wherein the first to polyol and the second polyol are present in a parts by weight ratio in the range of form from 1.6 to 1:2; (b) a blowing agent ; and (c) from 0.5 to 4 percent by weight a surfactant comprising the reaction product of a poly(alkyl siloxane) and a poly(alkylene oxide) copolymer, where the alkylene oxide are ethylene oxide, propylene oxide or butylene oxide, based on the total weight of the single component polyurethane foam forming composition, wherein said polyurethane foam forming composition forms an open-cell structure foam having open cells in the range of from 60% to 95% .