The present invention provides an acrylic thermoplastic resin containing 50 to 95% by mass of a repeating unit (X) derived from a methacrylate monomer represented by the following formula (1), 0.1 to 20% by mass of a repeating unit (Y1) derived from an N-substituted maleimide monomer (a) represented by the following formula (2), and 0.1 to 49.9% by mass of a repeating unit (Y2) derived from an N-substituted maleimide monomer (b) represented by the following formula (3), regarding the total amount of the repeating unit (X), the repeating unit (Y1), and the repeating unit (Y2) as 100% by mass:
The absolute value of a photoelastic coefficient (C) of the acrylic thermoplastic resin is not greater than 3.0 × 10-12Pa-1. The halogen atom content is less than 0.47% by mass with reference to the mass of the acrylic thermoplastic resin.
本发明提供了一种
丙烯酸热塑性
树脂,该
树脂含有 50%至 95%(以质量计)由下式(1)表示的
甲基丙烯酸酯单体衍生的重复单元(X),0.1%至 20%(以质量计)由下式(2)表示的 N-取代马来
酰亚胺单体(a)衍生的重复单元(Y1),以及 0.1至49.9%(质量百分比)的重复单元(Y2),该重复单元(Y2)来源于下式(3)所代表的N-取代马来
酰亚胺单体(b),而重复单元(X)、重复单元(Y1)和重复单元(Y2)的总量为100%(质量百分比):
丙烯酸热塑性
树脂的光弹性系数(C)的绝对值不大于 3.0 × 10-12Pa-1。相对于
丙烯酸热塑性
树脂的质量,卤原子含量小于 0.47%。