Polymer mixtures with optimized toughness/stiffness ratio and optical properties

A polymer mixture of polymer components A1 and A2 and/or A3:

• A1:
• from 5 to 95% by weight of a copolymer A1 of
• A11:
• from 60 to 80% by weight of at least one styrene or styrene derivative A11,
• A12:
• from 40 to 20% by weight of at least one ethylenically unsaturated monomer A12 comprising a nitrile group,
• A13:
• from 0 to 20% by weight of at least one other, copolymerizable monomer A13;
• A2:
• from 5 to 50% by weight of a graft copolymer A2 with median particle size from 90 to 280 nm, of:
• A21:
• from 60 to 80% by weight of at least one rubber-like graft base A21 with Tg<0° C. made of
• A211:
• from 70 to 99.9% by weight of at least one alkyl acrylate A211,
• A212:
• from 0.1 to 0.6% by weight of at least one allyl methacrylate A212,
• A214:
• from 0 to 29.9% by weight of at least one other of the following copolymerizable monomers A214 selected from methyl methacrylate, ethyl methacrylate, phenylmaleimide, acrylamide, and vinyl methyl ether,
• A22:
• from 20 to 40% by weight of at least one graft shell made of:
• A221:
• from 65 to 70% by weight of at least one vinylaromatic monomer A221,
• A222:
• from 30 to 35% by weight of at least one polar, copolymerizable unsaturated monomer A222;
• and/or
• A3:
• from 5-50% by weight of a graft copolymer A3 with particle size from 300 to 600 nm, of:
• A31:
• from 60 to 80% by weight of at least one rubber-like graft base A31 with Tg<0° C. made of:
• A311:
• from 70 to 99.9% by weight of at least one alkyl acrylate A311,
• A312:
• from 0.1 to 0.4% by weight of at least one allyl methacrylate A312,
• A314:
• from 0 to 29.9% by weight of at least one other of the following copolymerizable monomers A314 selected from methyl methacrylate, ethyl methacrylate, phenylmaleimide, acrylamide, and vinyl methyl ether,
• A32:
• from 20 to 40% by weight of at least one graft shell made of:
• A321:
• from 65 to 70% by weight of at least one vinylaromatic monomer A321,
• A322:
• from 30 to 35% by weight of at least one polar, copolymerizable unsaturated monomer A322,
• where the proportions by weight of polymer components A1, A2, and/or A3 give a total of 100% by weight.