| 摘要 |
<p>A composite article comprising a body of semi-rigid polyurethane foam in contact with a layer of sheet of polymeric material, the foam having been prepared by reacting an organic polyisocyanate with a polymeric polyol having a hydroxyl number in the range from 20 to 80 and a crosslinking agent or chain extender having a hydroxyl number of at least 250 in the presence of water and a catalytically effective amount of an alkali metal or alkaline earth metal salt of an acid of the formula : R-A-COOH wherein R represents R min OCO-, R min COO- or R min O-, R min represents an optionally substituted hydrocarbon or heterocyclic radical and A represents an optionally substituted C1-C3 chain.</p> |
