| 摘要 |
PURPOSE:To obtain the title base excellent in low double refraction, creeping resistance, low hygroscopicity, moldability and transparency, by copolymerizing a specified amount of methyl methacrylate with specified amount of methyl acrylate in the presence of, optionally, a chain transfer agent or the like in an amount suitable to control the reduced viscosity of the product. CONSTITUTION:1-8wt.% methyl acrylate (A) is copolymerized with 99-92wt.% methyl methacrylate (B) in the presence of a polymerization initiator (C) such as lauroyl peroxide and, optionally, a chain transfer agent (e.g., linear alkyl mercaptan or polymercaptan such as n-octyl mercaptan) in an amount suitable to control the reduced viscosity of the obtained copolymer to a desired value to obtain a copolymer containing 1-8wt.% component B unit and a reduced viscosity of 25-45ml/g (in chloroform at 25 deg.C). This copolymer is molded by, e.g., injection, extrusion or casting to obtain the titled base. |
