GB1330056A - Process for the manufacture of impact resistant styrene polymers - Google Patents

Abstract

1330056 Graft polymers CHEMISCHE WERKE HULS AG 19 April 1971 [21 Feb 1970] 22243/71 Heading C3G A process for the manufacture of an impact resistant polymer by polymerization of a solution of rubber in styrene or mixture of styrene and up to 50% by weight of at least one copolymerizable monomer in aqueous dispersion, optionally in the presence of one or more radicalforming catalysts, pre-polymerization being carried out in a water-in-oil emulsion and polymerization being subsequently completed in suspension after converting the water-in-oil suspension into an oil-in-water emulsion, comprises introducing a solution of 2-20% by weight of rubber in styrene or mixture with up to 50% by weight of at least one copolymerizable monomer and adding thereto an 0À05-1% by weight aqueous solution of an organic colloid in an amount such that the phase ratio of the rubber solution to water is 1 : 0À4 to 1 : 1À5 by weight, the mixture being vigorously stirred to achieve a water-in-oil emulsion, partially polymerizing the resulting water-in-oil emulsion at 50-150‹ C. up to a monomer conversion of 10-50%, and finally completing the polymerization at 100-180‹ C. after conversion of the water-in-oil emulsion to an oil-in-water emulsion optimally in the presence of an oil-inwater emulsifier. The copolymerizable monomer may be acrylonitrile or a substituted styrene such as α-methylstyrene or chlorostyrene. The rubber may be natural rubber, polybutadiene, butadiene - styrene copolymers, butadieneacrylonitrile copolymers, ethylene-propylene rubber or synthetic polyisoprene. The organic colloid may be hydroxyethylcellulose, polyvinyl alcohol or alkali metal salts of copolymers of styrene with acrylic acid, methacrylic acid, maleic acid or maleic anhydrides or mixtures thereof. The polymerization may be carried out in the presence of a free radical catalyst which may be used in an amount 0À01-0À5% by weight.