| 摘要 |
Organopolysiloxane copolymers comprising units of the general formulae <IMAGE> wherein R represents an alkyl group with 1 to 3 carbon atoms or a vinyl group, R' represents a divalent hydrocarbon radical with 1 to 10 carbon atoms, Q represents an organic radical of the formula -OG, <IMAGE> or -OSiR3 in which G represents an alkyl radical with 1 to 4 carbon atoms, and each R group, which may be identical or different, is as defined above, n represents 2, 3 or 4, the CnH2n group being straight or branched and y represents a number from 4 to 60; the CnH2n groups being the same or different, the ratio of the number of (CH3)2RSiO0.5 units to the number of SiO2 units being 0.55:1 to 0.75:1 and the ratio of the number of <IMAGE> units to the number of SiO2 units being 0.005:1 to 0.1:1 are used as stabilizers in the preparation of open-cell polyvinyl chloride foams. The raw foams can be easily shaped or moulded prior to gelling and gel without gain of density.
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