| 摘要 |
1467889 Production of expandable styrene polymers MONTEDISON SpA 17 May 1974 [18 May 1973] 22006/74 Headings C3P and C3C Styrene is polymerized or copolymerized in the presence of a conventional expanding agent and 0À001 to 1% by weight based on the weight of the styrene, of an elastomeric copolymer of ethylene and propylene or an elastomeric terpolymer of ethylene, propylene and a diene hydrocarbon. The preferred elastomeric polymers are (1) a copolymer of ethylene and propylene containing 10-90% by weight of ethylene and having an inherent viscosity between 0À25 and 4, and (2) a terpolymer containing 30- 70% (by weight) ethylene, 70-30% propylene and up to 15% of ethylidene norbornene. Other diene hydrocarbons mentioned are dicyclopentadiene (exemplified), 1,4-hexadiene, methylenenorbornene, butenylnorbornene and methyltetrahydroindene. The styrene may be copolymerized with such co-monomers as alphamethyl styrene, styrenes halogenated in the nucleus, acrylonitrile, methacrylonitrile, esters of acrylic and/or methacrylic acids with alcohols containing from 1 to 8 carbon atoms, and vinylcarbazole. The example discloses the preparation of expandable polystyrene particles and the moulding of shaped bodies therefrom. The expanding agent used was a mixture of npentane and isopentane. In a comparative experiment a polybutadiene rubber was included in the polymerization instead of one of the specified copolymers and terpolymers. |
