| 摘要 |
PURPOSE:To provide a methacrylate resin containing a methacrylic acid ester having an aromatic hydrocarbon group at the ester part as a component of a copolymer, keeping excellent optical properties and having excellent heat- resistance and low hygroscopicity. CONSTITUTION:(A) 10-90(wt)% methyl methacrylate, (B) 10-90% methacrylic acid ester having aromatic hydrocarbon group at the ester part (e.g. phenyl methacrylate, 2-naphthyl methacrylate, etc.) and (C) 0-40% vinyl monomer copolymerizable with the components A and B (e.g. methyl acrylate, styrene, etc.) are copolymerized preferably in the presence of a radical polymerization initiator (e.g. 2,2'-azobisisobutyronitrile). USE:Material for optical instruments, disk for information recording medium, etc. |
