Thermoplastic moulding compositions from a copolymer based on methacrylic acid esters and a five-stage emulsion graft copolymer

摘要

Thermoplastic moulding compositions essentially comprising (A) from 20 to 40 % by weight of a copolymer obtainable essentially from from 80 to 100 % by weight of at least one C1-C18-alkyl ester of methacrylic acid and from 0 to 20 % by weight of at least one C1-C18-alkyl ester of acrylic acid, and (B) from 60 to 80 % by weight of an emulsion graft copolymer built up essentially from (b1) from 2 to 10 % by weight of a core obtainable by polymerisation of a monomer mixture essentially comprising from 80 to 99.99 % by weight of methyl methacrylate (I), from 0.01 to 5 % by weight of allyl methacrylate (II), from 0 to 19.99 % by weight of a monofunctional comonomer (III) and from 0 to 3 % by weight of a difunctional or polyfunctional comonomer (IV), (b2) from 15 to 50 % by weight of a first shell, obtainable by polymerisation of a monomer mixture in the presence of the core (b1), essentially comprising from 60 to 89.99 % by weight of a C1-C20-alkyl ester of acrylic acid (V), from 10 to 39.99 % by weight of a vinyl aromatic monomer (VI), from 0.01 to 5 % by weight of allyl methacrylate (II), from 0 to 10 % by weight of methyl methacrylate (I) and/or a monofunctional comonomer (III) and from 0 to 3 % by weight of a difunctional or polyfunctional comonomer (IV), (b3) from 5 to 20 % by weight of a second shell, obtainable by polymerisation of a monomer mixture having the composition given under (b1) in the presence of the polymer obtained from step (b2), (b4) from 15 to 50 % by weight of a third shell, obtainable by polymerisation of a monomer mixture having the composition given under (b2) in the presence of the polymer obtained from step (b3), (b5) from 15 to 30 % by weight of a fourth shell, obtainable by polymerisation of a monomer mixture essentially comprising from 80 to 99.95 % by weight of methyl methacrylate (I), from 0 to 19.95 % by weight of a monofunctional comonomer (III) and from 0.05 to 2 % by weight of a regulator (VII), with the provisos that . the sum of the proportions of the shells (b2) and (b4) is in the range from 50 to 75 % by weight, and . the particle size (d50 value) of the emulsion graft copolymer has a mean diameter in the range from 100 to 200 nm. l