| 摘要 |
This invention describes how in a process to produce isocyanate-based rigid foams, swelling agent used is a mixture of at least a low boiling point hydrocarbon having from 3 to 7 carbon atoms, low molecular weight monohydric alcohols containing primary or secondary hydroxyl groups, and having from 1 to 4 carbon atoms and, if desired, carbon dioxide formed from water and isocyanate. Rigid foams can be used as an isolation material.
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