Patent ID: 6087449
Filing Date: 2000-07-11
Classification: C08L

Abstract:
A thermoplastic molding material containing a mixture of(A) from 10 to 60% by weight of a methyl methacrylate polymer obtainable by polymerizing a mixture consisting of(A1) from 90 to 100% by weight, based on (A), of methyl methacrylate and(A2) from 0 to 10% by weight, based on (A), of a C.sub.1 -C.sub.8 - alkyl ester of acrylic acidand(B) from 10 to 70% by weight of a copolymer obtainable by polymerizing a mixture consisting of(B1) from 75 to 88% by weight, based on (B), of a vinyl-aromatic monomer and(B2) from 12 to 25% by weight, based on (B), of a vinyl cyanideand(C) from 15 to 50% by weight of a graft copolymer obtainable from(C1) from 40 to 80% by weight, based on (C), of a core obtainable by polymerizing a monomer mixture consisting of(C11) from 65 to 90% by weight of a 1,3-diene and(C12) from 10 to 35% by weight of a vinylaromatic monomerand(C2) from 10 to 30% by weight, based on (C), of a first graft shell obtainable by polymerizing a monomer mixture consisting of (where the individual stated percentages C21, C22 and C23 sum to 100% by weight)(C21) from 30 to 60% by weight of a vinylaromatic monomer,(C22) from 40 to 60% by weight of a C.sub.1 -C.sub.8 -alkyl ester of methacrylic acid and(C23) from 0 to 2% by weight of a crosslinking monomerand(C3) from 10 to 30% by weight, based on (C), of a second graft shell obtainable by polymerizing a monomer mixture consisting of(C31) from 70 to 98% by weight of a C.sub.1 -C.sub.8 -alkyl ester of methacrylic acid and(C32) from 2 to 30% by weight of a C.sub.1 -C.sub.8 -alkyl ester of acrylic acid,the individual stated percentages of A, B and C in the mixture summing to 100% by weight, and(D) optionally, conventional additives in amounts of up to 20% by weight, based on the sum of the components A, B and C,with the provisos that the ratio of (C2) to (C3) is from 2:1 to 1:2, the refractive index of the first graft shell (n.sub.D -C2) is greater than the refractive index of the second graft shell (n.sub.D -C3) and the refractive index of the total graft shell (n.sub.D -C2+n.sub.D -C3) is less than the refractive index of the core (n.sub.D -C1), the magnitude of the difference between the refractive index of the total component C (n.sub.D -C) and that of the total matrix (n.sub.D -A+n.sub.D -B) is less than or equal to 0.02.