GB901386A - New polymeric compositions - Google Patents

Abstract

A thermoplastic moulding composition comprises a hard resinous polymer derived essentially from styrene and/or methyl methacrylate and a rubbery copolymer of butadiene and a monoethylenically unsaturated compound, the resin and the rubber each containing either free carboxyl groups or basic nitrogen atoms or amido nitrogen atoms so that one polymer has acidic groups and one basic group, there being from 50 to 90% of the resinous copolymer present based on the combined resinous and rubbery polymers. The carboxyl containing polymer may contain from 2,5 to 7,5% of carboxyl groups, the basic nitrogen containing polymer 0,2 to 2% nitrogen atoms. The butadiene copolymer may have as comonomer styrene, acrylonitrile, methacrylonitrile, methyl acrylate or ethyl acrylate or preferably 15 to 60% of methyl methacrylate and may be crosslinked to the extent of 0,1 to 5% of divinyl benzene or glycol dimethacrylate. The carboxyl polymer may be obtained by polymerizing the monomer together with an ethylenically unsaturated carboxylic acid, e.g. acrylic, methacrylic, maleic and fumaric acids. Alternatively the carboxyl containing polymer may be polymethyl methacrylate in which some of the ester groups have been hydrolysed to carboxyl groups. The nitrogen-containing polymer may be obtained by polymerizing the monomer and an ethylenically unsaturated basic compound containing basic nitrogen or amido nitrogen atoms, e.g. 2- or 4-vinyl pyridine, N-dimethylamino-ethyl methacrylate, acrylamide, methacrylamide, crotonamide, vinyl phthalimide, N-tert.-butyl acrylamide, di-N-ethylacrylamide and vinyl pyrrolidone. The moulding compositions may be obtained by coagulating the polymers together or separately while in stable aqueous dispersion and thereafter masticating in a mixer.