THERMOPLASTIC MOLDING COMPOSITIONS WITH IMPROVED OPTICAL PROPERTIES

摘要

The present invention relates to thermoplastic molding compositions comprising a mixture of (a) 10 to 50% by weight, based on the sum of components (A), (B) and (C), of a methyl methacrylate polymer as component (A) and (b) 20 to 60% by weight, based on the sum of the components (A), (B) and (C), of a copolymer as component (B), obtainable by polymerizing a vinylaromatic monomer and a vinyl cyanide, and 20 to 70% by weight, based on the sum of components (A), (B) and (C), of graft copolymer as component (C), obtainable from (c1) 50 to 70% by weight, based on (C), of a core as component (C1), obtainable by polymerizing a 1,3-diene and a vinylaromatic monomer and an agglomeration polymer and (c2) 15 to 25% by weight, based on (C), of a first graft shell as component (C2), obtainable by polymerizing a vinylaromatic monomer, a C1-C8-alkyl ester of methacrylic acid and/or a C1-C8-alkyl ester of acrylic acid and a crosslinking monomer and (c3) 15 to 25% by weight, based on (C), of a second graft shell as component (C3), obtainable by polymerizing a C1-C8-alkyl ester of methacrylic acid as component (C31) and a further monomer as component (C32), it being essential to the invention that component (C32) is a vinylaromatic monomer and graft copolymer (C) is prepared by emulsion polymerization and isolated from the reaction mixture by shear precipitation, and to processes for producing these molding compositions, to the use thereof and to the moldings obtainable thereby.