摘要 |
This invention relates to a process for the production of polyurethane foams in closed molds using mixtures of organic polyisocyanates with certain compounds which liberate carbon dioxide under the catalytic influence of basic compounds. In this process a mixture of polyisocyanates and compounds which liberate carbon dioxide under the catalytic influence of basic compounds is reacted with organic compounds containing hydrogen atoms which are reactive with isocyanate groups, which organic compounds are mixed with basic compounds and/or have basic compounds chemically built into them. The process is suitable for the production of any polyurethane foams in a closed mold, but is preferably applied to the production of semi-hard and particularly of hard polyurethane foams having a dense outer skin. |