| 摘要 |
PURPOSE:To obtain a high-performance substrate material for an optical disc having superior heat resistance and transparency and a small birefringence and having no possibility of cracking in molding, by blending a specific glycerin fatty ester in the amount of 0.01-10pts.wt. per 100pts.wt. of a specific methacrylimide-containing polymer. CONSTITUTION:A glycerin fatty ester shown by a formula (II) is blended in the amount of 0.01-10pts.wt. per 100pts.wt. of a methacrylimide-containing polymer containing at least 5wt.% of methacrylimide units shown by a formula (I). The methacrylimide units are preferably incorporated in the amount of at least 5wt.%, preferably 20wt.% or more. The content less than 5wt.% results in the reduction of a heat distorsion temperature. As the ester group of the glycerin fatty ester, stearate, linolenate, and oleate, are particularly preferable. In addition, in the formula, R1 represents a hydrogen atom, 1-20 C substd. or unsubstd. alkyl group, cycloalkyl group, phenyl group, or aryl group, and R2 represents 5-30 C alkyl group. |
