Patent ID: 8193257

Claim:
A process for preparing a rigid polyurethane foam, comprising a) forming a reactive mixture containing at least 1) a mixture of an amine-initiated polyol that has a functionality of 3.7 to 4.0, a hydroxyl equivalent weight of from 100 to 130 and which is a reaction product of 1,8-diamino-p-menthane and a C 2 -C 4 alkylene oxide with at least one polyether polyol having a functionality of from 4.5 to 7 and a hydroxyl equivalent weight of 100 to 175, provided that such a mixture contains at least 5% by weight of the amine-initiated polyol; 2) at least one hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether or fluorine-substituted dialkyl ether physical blowing agent; and 3) at least one polyisocyanate; wherein the reactive mixture further contains water, and b) subjecting the reactive mixture to conditions such that the reactive mixture expands and cures to form a rigid polyurethane foam.