| 摘要 |
There is now provided a polyol composition containing a polyol having polyester linkages, an aliphatic or cycloaliphatic C4-C7 hydrocarbon blowing agent, an d a polyoxyalkylene polyether monool initiated with a C8-C24 fatty hydrocarbon having one alkylene oxide active hydrogen atom. We have found that the monool emulsifie s the C4-C7 blowing agent in the compound having polyester linkages, to form an emulsifi ed polyol composition, after which an organic aromatic isocyanate may be reacted with the emulsified polyol composition to form a closed cell polyurethane foam. The polyol composition is used to make rigid closed cell polyisocyanate base d foams which are dimensionally stable, and have good insulation values and flame retardance. Combining the monool with the polyester based polyol produces a foam having a density lower than that of a reference foam made with the same ingredients and amoun ts except in the absence of the monool. Whether the monool is merely mixed with the polyol or used to form an emulsion with the hydrocarbon blowing agent and the polyol, the foam density may be lowered when the monool is used.
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