Polycarbonate/abs compositions of high heat resistance

Claim 1

A thermoplastic molding composition comprising a blend of: A. 3 to 99 parts by weight of an aromatic polycarbonate wherein at least 20 mol % by weight of the bifunctional carbonate structural unit correspond to the formula (I) ##STR6## wherein R 1 and R 2 independently of one another denote hydrogen, halogen, C 1 -C 8 -alkyl, C 5 -C 6 -cycloalkyl, C 6 -C 10 -aryl or C 7 -C 12 -aralkyl, m is an integer from 4 to 7, R 3 and R 4 are selected individually for each X and independently of one another denote hydrogen or C 1 -C 6 -alkyl and X denotes carbon with the proviso that R 3 and R 4 on at least one atom X simultaneously denote alkyl, B. 3 to 95 parts by weight of copolymer of (i) (ii) or (iii) where (i) is a mixture of 50 to 98% by weight of at least one member selected from the group consisting of a α-methylstyrene, nuclear substituted styrene, and 50 to 2% by weight of at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, C 1 -C 8 -alkyl methacrylate, C 1 -C 8 -alkyl acrylate, maleic anhydride and N-substituted maleamides, and where (ii) is a mixture of 50 to 98% by weight of at least one member selected from the group consisting of α-methylstyrene, nuclear substituted styrene, C 1 -C 6 -alkyl methacrylate and C 1 -C 8 -alkyl acrylates and 50 to 2% by weight of at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, maleic anhydride and N-substituted maleamides, and where (iii) is a mixture of at least two members selected from the group consisting of C 1 -C 8 -alkyl methacrylate and C 1 -C 8 -alkyl acrylates, C. 1 to 95 parts by weight of a diene rubber based graft polymer of C.1 5 to 90 parts by weight of (i) (ii) or (iii) on 95 to 10 parts by weight of C.2 where (i) is a mixture of 50 to 98% by weight of at least one member selected from the group consisting of styrene, α-methylstyrene, styrenes substituted on the nucleus by C 1 -C 4 alkyl or halogen, and 5 to 50% by weight of at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, C 1 -C 8 -alkyl methacrylates, C 1 -C 8 -alkyl acrylates, maleic anhydride, C 1 -C 4 -alkyl-N-substituted maleimides and phenyl-N-substituted maleimides, and where (ii) is a mixture of 50 to 98% by weight of at least one member selected from the group consisting of styrene, α-methylstyrene, styrenes substituted on the nucleus by C 1 -C 4 -alkyl or halogen, C 1 -C 8 -alkyl methacrylates and C 1 -C 8 -alkyl acrylates, and 5 to 50% by weight of at least one member selected from the group consisting of acrylonitrile, methacrylonitrile, maleic anhydride, C 1 -C 4 -alkyl-N-substituted maleimides and phenyl-N-substituted maleimides, and where (iii) is at least two members selected from the group consisting of C 1 -C 8 -alkyl methacrylates and C 1 -C 8 -alkyl acrylates, and where C.2 is a diene rubber having an average particle diameter (d 50 ) of 0.09 to 1 μm and a gel content of more than 50 weight %, D. 0 to 80 parts by weight of aromatic polycarbonate different from said polycarbonate A.