| 摘要 |
PROBLEM TO BE SOLVED: To provide an aromatic vinyl/vinyl cyanide compound/N-substituted maleimide copolymer having heat resistance, transparency and high mechanical strengths and having a content of residual unreacted N-substituted maleimide of 50ppm or below and to provide a thermoplastic resin composition containing the same. SOLUTION: This copolymer comprises 30-70wt.% units derived from an aromatic vinyl compound, 4-40wt.% units derived from a vinyl cyanide compound and 26-50wt.% units derived from an N-substituted maleimide and has the following properties: the compositional distribution is narrow for every fraction prepared by fractionating the sample on the basis of the molecular weight determined by GPC, it is substantially free from acetone insolubles, the weight- average molecular weight is 100,000-300,000, the number-average molecular weight is 50,000-150,000, and the content of residual unreacted N-substituted maleimide is 50ppm or below. The composition contains the above copolymer. |
