GB916776A - Foamable thermoplastic polymers - Google Patents

Abstract

A foamable material comprises a thermoplastic polymer of a monovinylidene aromatic hydrocarbon and/or halohydrocarbon or a mixture of such a polymer with another polymer which polymer or mixture contains more than 50% by weight of the hydrocarbon and/or halohydrocarbon, and has uniformly dispersed therein at least 0,5% by weight of an inorganic filler powder and 3-10% of an aliphatic hydrocarbon boiling in the range 10 DEG -100 DEG C. alone or admixed with another organic liquid boiling in the same range. Lists of suitable fillers and hydrocarbons are given. Polymers specified are:- homopolymers of, e.g. styrene or interpolymers with, e.g. butadiene, isoprene, acrylic acid, methyl-, ethyl-, 2-ethylhexyl acrylates and methacrylates, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, mono- and dialkyl esters of maleic and fumaric acids, vinyl formate, acetate and stearate, ethylene, acenaphthalene vinyl and vinylidene chlorides, vinyl methyl ether and vinyl butyl ether. The monovinylidene compound may be partially replaced by, e.g. a methyl- or a ethyl styrene; op- or m-vinyl toluene; op- or m-ethyl styrene, a methyl 2,4-dimethyl styrene; 2,4-dimethyl or 2,4-dichlorostyrene; o-, p- or m-chlorostyrene; or 2-chloro, 4-methyl styrene. The polymers preferably have a M.W. (Staudinger) of 40,000-100,000.ALSO:A foamable material comprises a thermoplastic polymer of a monovinylidene aromatic hydrocarbon and/or halohydrocarbon or a mixture of such a polymer with another polymer which polymer or mixture contains more than 50% by weight of the hydrocarbon and/or halohydrocarbon, and has uniformly dispersed therein at least 0,5% by weight of an inorganic filler powder and 3-10% of an aliphatic hydrocarbon boiling in the range 10 DEG -100 DEG C. alone or admixed with another organic liquid boiling in the same range. Specified are: fillers:- carbon blacks, clays, limestone, bauxite, ultramarine blue, cadmium yellow, ferrocyanide pigments, carbonate silicate and sulphate of calcium, barium sulphate, iron oxide, alumina, thoria, diatomaceous earth and silica: aliphatic hydrocarbons:-pentane, isopentane, cyclo pentane, heptane and petroleum ethers: polymers:- homopolymers of unsubstituted monovinylidene aromatic hydrocarbons e.g. styrene, or interpolymers with e.g. butadiene, isoprene, acrylic acid, methyl-, ethyl-, and 2-ethylhexyl acrylates and methacrylates, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, mono- and dialkyl esters of maleic and fumaric acids, vinyl formate, acetate and stearate, ethylene, acenaphthalene, vinyl and vinylidene chlorides, vinyl methyl ether and vinyl butyl ether. The monovinylidene hydrocarbon may be partially replaced by other compounds-a list being given. The materials become cellular after placing in boiling water.