Patent ID: 6733707
Filing Date: 2004-05-11
Classification: C08G

Abstract:
A method of manufacturing a microcellular polyurethane foam comprising the steps of:selecting an isocyanate-terminated prepolymer containing less than 12% functionality; preparing a curative component by mixing a polyol, water, a foam surfactant, and a catalyst component comprising a standard solid cast polyurethane catalyst and a delayed-action tin catalyst, wherein the ratio of tin catalyst to standard solid cast polyurethane catalyst component is about 1.25:1 and said water comprises between 1% and 5% of weight of said curative component; and mixing said curative component with said isocyanate-terminated prepolymer at a functional group (NCO/OH) ratio of about 1:1, provided that if said isocyanate-terminated prepolymer or said curative component is present in excess of one over the other, the maximum percentage of said excess over the other is 2%.