| 摘要 |
PURPOSE:To improve the deformability of an optical disk due to water absorption and the double refractivity by using a copolymer consisting of alkyl acrylate, alkyl methacrylate and alpha-substituted aromatic vinyl compound as the base material of the disk. CONSTITUTION:A copolymer is composed of 0-20pts.wt. alkyl acrylate, 20- 90pts.wt. alkyl methacrylate and 80-10pts.wt. alpha-substituted aromatic vinyl compound, and it is preferably composed of 0-20pts.wt. alkyl acrylate, 40- 80pts.wt. alkyl methacrylate and 60-20pts.wt. alpha-substituted aromatic vinyl compound. Thus, the copolymer can satisfy necessary physical properties such as transmittance, deformability due to water absorption and double refractivity. |
