Graft copolymer for moulding materials with high cold impact strength

摘要

Graft copolymers (GCP) are obtd. by (A) copolymerisation of 25-60 wt.% of a mixt. of (a1) 70-99.9 wt.% (1-18C alkyl) acrylate, opt. with a Ph- or PhO-substd. alkyl gp.; (a2) 0.1-10 wt.% polyfunctional monomer and (a3) 0-29.9 wt.% other unsatd. comonomer, in presence of 5-25 wt.% crosslinked silicone rubber, followed by (B) polymerisation of 5-25 wt.% of a mixt. of (b1) 50-100 wt.% styrene cpd. of formula and/or (1-8C alkyl) (meth)acrylate and (b2) 0-50 wt.% (meth)acrylonitrile, (meth)acrylic acid, maleic anhydride, N-(1-4C alkyl)-substd. maleimide, vinyl 2-8C aliphatic carboxylate, acrylamide or vinyl methyl ether, in the presence of graft copolymer (A); R<1>, R<2> = H, 1-8C alkyl or Ph (opt. substd. with up to 3 1-4C alkyl gps.) Also claimed are thermoplastic moulding materials (TMM) contg. 5-95 wt.% (GCP) and 95-5 wt.% copolymer (C) derived from (c1) 50-100 wt.% monomer as in (b1), (c2) 0-50 wt.% monomer as in (b2), (c3) 0-90 wt.% polycarbonate and (c4) 0-100 wt.% conventional additives. Also claimed is the above process for the prodn. of GCP, and a process for the prodn. of TMM by mixing GCP and copolymer (C) in the above amts. by known methods. Also claimed are moulded prods. obtd. from GCP and TMM.