Heat resistant copolymer composition

Claim 1

A heat resistant copolymer composition comprising: 5 to 95% by weight of a copolymer (I) which is obtainable by copolymerizing (A) a maleimide monomer (B) an aromatic vinyl monomer, (C) an unsaturated nitrile monomer, and 0% to 50% by weight of the total weight of (A), (B), (C), and (D) of (D) at least one other comonomer copolymerizable with (A), (B) and (C) in the presence of 0% to 80% by weight of the total weight of (A), (B), (C), (D) and (E) of (E) an elastomeric polymer and has an intrinsic viscosity of 0.3 to 1.2 dl/g, and 95 to 5% by weight of a copolymer (II) which is obtainable by copolymerizing (B) the aromatic vinyl monomer, (C) the unsaturated nitrile and 0 to 50% by weight of the total weight of (B), (C) and (D) of (D) at least one other comonomer copolymerizable with (B) and (C) in the presence of 0% to 80% by weight of the total weight of (B), (C), (D) and (E) of (E) an elastic polymer and has an intrinsic viscosity of 0.3 to 1.5 dl/g, wherein the total weight percentage of the monomers (A) and (C) in the copolymer (I) per total weight of the monomers (A), (B), (C) and (D) in the copolymer (I) and the weight percentage of the monomer (C) in the copolymer (II) per total weight of the monomers (B), (C) and (D) in the copolymer (II) satisfy the following equation: (Said total weight percentage of the monomers (A) and (C) in copolymer (I))-(Said weight percentage of the monomer (C) in copolymer (II))=+40 to -15% by weight, and wherein the intrinsic viscosities of the copolymers (I) and (II) satisfy the following equation: (The intrinsic viscosity of the copolymer(I))-(The intrinsic viscosity of the copolymer (II))=+0.5 to -1.2 dl/g, wherein all intrinsic viscosities refer to the intrinsic viscosity of the non-grafted polymers, when grafted polymers are present, said copolymer (I) having a composition of the monomers (A), (B), (C) and (D) satisfying the following equations (1), (2), and (3) wherein (A), (B), (C) and (D) stand for the respective weights thereof: ##EQU10## where (F) ranges from 1 to 60% by weight, (G) ranges from 99 to 40% by weight and (H) ranges from 5 to 45% by weight, said copolymer (II) having a composition of the monomers (B) and (C) satisfying the following equation (4) wherein (B) and (C) stand for the respective weights thereof: ##EQU11## where (J) ranges from 20 to 45% by weight.