Patent ID: 6846850

Claim:
A process for preparing a rigid polyurethane foam comprising reacting: a) an organic polyisocyanate with b) a sorbitol-based polyether polyol having a number average molecular weight of from about 400 to about 1500, b1) an o-toluene diamine-based polyether polyol, b2) a polyester polyol, and b3) water in the presence of c) a pentafluoropropane blowing agent, selected from the group consisting of 1,1,2,2,3-pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1,1,2,3-pentafluoropropane and 1,1,1,3,3-pentafluoropropane, d) a tertiary amine catalyst.