| 摘要 |
1,134,954. Foamed thermoplastic compositions. STAMICARBON N.V. 7 June, 1966 [11 June, 1965], No. 25405/66. Addition to 1,026,495. Headings C3C and C3P. Foamed plastics are prepared from a mixture of from 95-50% by weight of a polyolefin and from 5-50% by weight total of one or more thermoplastic substances in which a physical blowing agent dissolves better than in the polyolefin and a wax, having a solidification point higher than said mixture and being in intimate admixture therewith, by expansion using a physical blowing agent. The polyolefin is a polymer of at least 90 moles per cent of one or more compounds with the general formula H 2 C = CHR, where R is a hydrogen atom, an alkyl group or a cyclo-alkyl group, and from 0 to 10 moles per cent of a comonomer. Ethylene polymers are preferred with, if desired, at most 10 moles per cent of one or more comonomers, such as acrylic acid, methacrylic acid, vinyl acetate and vinyl benzoate. Thermoplastic substances include the polymers of styrene, vinyl toluene, vinyl xylene and other monovinyl aromatic hydrocarbons. Mixtures which are either homopolymers or copolymers of these monomers with another copolymerizable monomer may also be used. Halogenated alkanes, e.g. trichlorofluoromethane are mentioned as physical blowing agents. |
