| 摘要 |
1522254 Chlorinated vinyl chloride polymer foams TOKUYAMA SEKISUI KOGYO KK 3 Nov 1976 [5 Nov 1975] 45753/76 Heading C3C A foam of a chlorinated vinyl chloride polymer, having a chlorine content of 60-75% by wt., is made by impregnating 100 parts by wt. of the polymer with 1-50 parts by wt. of a blowing agent which is a C1-5 alcohol, and heating the impregnated polymer to a temperature and for a time sufficient to cause it to foam. In the examples (a) a polyvinyl chloride or a propylene/vinyl chloride copolymer was chlorinated in aqueous suspension and then (b) mixed with ethyl, methyl, or aryl alcohol as blowing agent and optionally calcium carbonate methyl methacrylate/butadiene/styrene copolymer, dibutyl tin maleate and/or a polymeric lubricant and the mixtures were then either (I) placed in a mould which was heated under pressure and a foam was obtained when the pressure was released, or (XI) fed to an extruder to obtain a foamed rod.
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