| 摘要 |
The present invention relates to a process for the production of polyurethane plastics by reacting compounds containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range of from 400 to 10,000, polyisocyanates and, optionally, chain extenders having a molecular weight of from 32 to 400, foam stabilizers, water and/or organic blowing agents in the presence of catalysts containing tertiary nitrogen. These catalysts are characterized in that mixtures of (a) one or more cross-linking catalysts corresponding to the following general formula: <IMAGE> wherein R1, R2, R3 and R4 which may be the same or different, represent C1-C5-alkyl radicals, preferably CH3- or C2H5 radicals, R' and R'' represent hydrogen or the same or different C1-C3-alkyl radicals, preferably CH3- or C2H5- radicals, and n represents an integer of from 1 to 10, preferably from 4 to 8, (b) blowing catalysts corresponding to the following general formula: <IMAGE> wherein R1, R2, R3 and R4, are as defined above and X represents oxygen or <IMAGE> where R''' represents a C1-C5 alkyl radical, preferably a CH3- or C2H5- radical, p represents an integer of from 2 to 4 and r represents an integer of from 1 to 3, and m and o which may be the same or different, represent numbers ranging from 1 to 10, preferably from 1 to 3 in value.
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