Patent ID: 8318828

Claim:
A process for preparing a rigid polyurethane foam, comprising a) forming a reactive mixture consisting of 1) a polyol mixture that includes (i) a reaction product of a C 2 -C 4 alkylene oxide with 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, or a mixture thereof, the reaction product having a hydroxyl functionality of 3.7 to 4.0 and a hydroxyl equivalent weight of from 100 to 130, (ii) 20 to 70% of a sorbitol or sucrose and glycerin initiated polyether polyol having an average functionality of 4.5 to 7 hydroxyl groups and a hydroxy equivalent weight of 100 to 175 (iii) 2 to 20% by weight of an ethylenediamine-initiated polyol having an equivalent weight of 100 to 225 and (iv) 0 to 15% by weight of a non-amine-initiated polyol having a functionality of 2.0 to 3.0 and a hydroxyl equivalent weight of 200 to 500; 2) at least one hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether or fluorine-substituted dialkyl ether physical blowing agent; and 3) at least one polyisocyanate; 4) water; 5) one or more catalysts for the reaction of the polyols and water with the polyisocyanate; 6) a surfactant; and 7) optionally one or more of a filler, a colorant, an odor mask, a flame retardant, a biocide, an antioxidant, a UV stabilizer, an antistatic agent; and b) subjecting the reactive mixture to conditions such that the reactive mixture expands and cures to form a rigid polyurethane foam.