Patent ID: 6569913
Filing Date: 2003-05-27
Classification: C08G

Abstract:
A process for preparing a flexible polyurethane foam comprising reacting:water; a polyether polyol having an equivalent weight of 1,000 to less than 2200, and a nominal hydroxyl functionality of 2-4; and an isocyanate-terminated prepolymer composition comprising: A) a urethane containing adduct of: (i) diphenylmethane diisocyanate, optionally containing oligomers of diphenylmethane diisocyanate, said oligomers having an isocyanate functionality of more than 2, and (ii) a polyoxyethylene polyoxypropylenepolyether polyol, having (a) an equivalent weight of 2,200-10,000, (b) a nominal hydroxyl functionality of 2-4, (c) an oxyethylene content of 5-30% by weight, relative to the total weight of oxyalkylene units present, B) (i) 2-15% by weight, relative to the composition, of unreacted oligomers of diphenylmethane diisocyanate, said oligomers having an isocyanate functionality of at least 3, and/or (ii) 1-25% by weight, relative to the composition, of toluene diisocyanate; wherein said isocyanate-terminated prepolymer composition has an NCO-content of 8-22% by weight, relative to the composition, when no toluene diisocyanate is present and an NCO-content of 8.5-26% by weight, relative to the composition, when toluene diisocyanate is present, and the polyether moieties are present in an amount of from 35-70% by weight, relative to the weight of the composition.