摘要 |
This invention relates to the use of phosphorus-containing compounds, specifically cyclic organophosphorus compounds, as carbodiimidization catalysts in the preparation of open-celled flexible polyurethane foam for the purpose of controlling foam density and providing softer foams. foams that are softer and of lower density can be prepared with significantly reduced quantities of blowing agents in comparison to foams prepared in the absence of such phosphorus-containing compounds. Additionally, use of such catalysts provides for a reduced reaction exotherm during the preparation of the foam thereby minimizing foam discoloration or scorching. Preferred phosphorus-containing compounds are the 1-alkyl-1-oxophospholenes, especially 1-methyl-1-oxophospholene.
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