| abstract |
The present invention relates to imidazole and/or its derivative as polyurethane or polyisocyanurate foam catalyst in the presence of Low Global Warming Potential (GWP) halogenated olefinic blowing agents, such as the hydrochlorofluoroolefin (HCFO) HCF0-1233zd. More particularly, the present invention relates to catalyst compositions comprising imidazole and/or its derivative. The present invention further relates to the stable pre-blend formulations and resulting polyurethane or polyisocyanurate foams. A method for stabilizing thermosetting foam blends comprises combining: (a) a polyisocyanate and, optionally, isocyanate compatible raw materials; and (b) a polyol pre-mix composition comprising a halogenated olefinic blowing agent, a polyol, a surfactant and a catalyst. |