摘要 |
<p>The present invention relates to a process for producing a cellular or microcellular polyurethane foam wherein the reactants provide a built-in blowing capability. The process is effected by reacting a polyisocyanate with a carboxy-modified polyol to form a polyurethane and carbon dioxide, said carbon dioxide acting as an in situ blowing agent to foam said polyurethane into a cellular or microcellular polyurethane foam. In another aspect, the present invention relates to a process for forming an integral skin cellular or microcellular polyurethane foam by reacting, in a closed mold, a polyisocyanate with a carboxy-modified polyol to form a polyurethane and carbon dioxide.</p> |