Patent ID: 6803390
Filing Date: 2004-10-12
Classification: C08G,Y10T

Abstract:
A method of making a rigid polyurethane foam, comprising mixing a polyisocyanate component with a polyol component in the presence of at least one catalyst for the reaction of a polyol or water with a polyisocyanate and subjecting the mixture to conditions sufficient to cure to form a polyurethane foam having a bulk density of 45 pounds per cubic foot (720 kg/m3) or less, wherein(a) the polyisocyanate component contains an isocyanate-terminated prepolymer made by reacting an excess of an organic polyisocyanate with (i) at least one polyol and (ii) at least one hydroxy-functional acrylate or methacrylate, (b) the polyol component contains an effective amount of a blowing agent and isocyanate-reactive materials have an average functionality of at least about 2.3 and include at least one polyol and, (c) the volume ratio of the polyisocyanate component to polyol component is no greater than 10:1, and (d) the ratio of isocyanate groups in the polyisocyanate component to the number of isocyanate-reactive groups in the polyol component is from about 0.8:1 to about 1.5:1.