Patent ID: 6153712
Filing Date: 2000-11-28
Classification: C08F

Abstract:
A thermoplastic copolymer containing a residual group of an aromatic vinyl monomer in a range of 5 weight percent to 85 weight percent, a residual group of a vinyl cyanide monomer in a range of 5 weight percent to 35 weight percent, a residual group of a maleimide in a range of 10 weight percent to 50 weight percent, and a residual group of a vinyl monomer (b) copolymerizable with the above three monomers in a range of 0 weight percent to 20 weight percent,wherein said thermoplastic copolymer satisfies:YI.sub.1 <(1.5.times.X.sup.2 /100)+5;andYI.sub.2 /YI.sub.1 <1.5where YI.sub.1 is a yellowness index of a 15 weight percent chloroform solution of said thermoplastic copolymer, YI.sub.2 is a yellowness index of a 15 weight percent chloroform solution of said thermoplastic copolymer after heated at 265.degree. C. for four minuets, and X is a weight percent of the residual group of the maleimide.