GB1303308A - - Google Patents

Abstract

1303308 Craft polymers POLYMER CORP Ltd 12 Nov 1970 [24 Dec 1969] 53830/70 Heading C3G A process of preparing ABS and MBS resins comprises: (1) dissolving a mixture of preformed rubbery polymer A and preformed polymer B in a mixture of grafting monomers, (2) prepolymerizing with agitation the mixture so formed to a conversion of grafting monomers of from 10 to 40% preferably 20-40%, whereby a dispersion is formed of a solution of said preformed polymers, in a solution of a polymer of said grafting monomers, said solutions being solutions in the residual grafting monomers, (3) continuing the polymerization of the residual grafting to at least 50% conversion, said continued polymerization being carried out in bulk or in aqueous suspension under suspension conditions, and (4) recovering the thermoplastic resin so formed, wherein polymer A is a polydiolefin having a 1,4-content of at least 85%, and polymer B is a polymer of butadiene-1,3 having at least 50% of butadiene units in the 1,2- configuration, and said grafting monomers comprise a mixture of styrene or a polymerizable homologue of styrene with one or more of acrylonitrile, polymerizable homologues of acrylonitrile, methyl methacrylate and polymerizable homologues of methyl methacrylate. Polymer A is preferably a polybutadiene, such as a cis-polybutadiene, or a polyisoprene. Polymer B may be a hcmopolymer of butadiene such as a polybutadiene having a 1,2-content of at least 80%, or a copolymer of butadiene with less than 50% by weight of a copolymerisable monomer such as styrene, α-methyl styrene, acrylonitrile, methacrylonitrile and methyl methacrylate, or a block copolymer of an alkenyl aromatic hydrocarbon and butadiene-1,3 such as polystyrene-polybutadiene-polystyrene, polystyrene - butadiene/styrene copolymer, polystyrene - butadiene / styrene copolymer - polystyrene, polystyrene - polybutadiene - poly α-methyl styrene, and poly α-methyl styrenepolybutadiene-poly α-methyl styrene. The weight ratio of polymer A to polymer B is preferably greater than 1 : 1, more preferably 10 : 1-1À5 : 1. The continued polymerization is preferably carried out in aqueous suspension medium comprising an aqueous solution of polyvinyl alcohol. The pre-polymerization in bulk is preferably carried out at 50-120‹ C. and the continued polymerization, if still in bulk, is preferably carried out at 30-200‹ C. The polymer produced by the process comprises 15-75% by weight of polymerized styrene and/or its polymerizable homologues, 12-30% by weight of polymerized acrylonitrile, methyl methacylate and/or their polymerizable homologue and 5-30% by weight of the rubber.