| 摘要 |
A method for producing a rigid, closed-cell polyurethane foam having a free-rise density of from about 1.3 lbs/ft.3 to about 4 lbs/ft.3 and exhibiting a shrinkage of less than 10%, comprises mixing together an isocyanate, at least one alkyl alkanoate blowing agent and at least one polyol having a hydroxyl number of from about 150 to about 800 and being selected from the group consisting of polyalkoxylated amines, polyalkoxylated ethers, and polyester polyols, to form a reaction mixture that is curable to produce such foam.
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