| 摘要 |
<p>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.</p> |
