| 摘要 |
PURPOSE:The titled material excellent in optical properties, heat resistance and mechanical strength, comprising a specified polycarbonate resin obtained by reacting a bisphenol with phosgene. CONSTITUTION:A bisphenol is reacted with phosgene in a solvent in the presence of, optionally, an alkali, a modifier, etc., to obtain a material for optical appli ances comprising a polycarbonate resin having repeating units of the formula (wherein R<1-2> are each a 1-5C alkyl 1-5C alkoxy, aryl, cycloalkyl or a halogen and R<3-4> are each a 1-5C alkyl or aryl, provided that the case where both of R<3> and R<4> are methyl is excluded) and a reduced viscosity (etasp/c], as deter mined in a methylene chloride solution of a concentration of 0.5g/dl at 20 deg.C, of 0.3-1.0dl/g. This material and, if necessary, additives such as an antioxidant and an ultraviolet absorber are molded into a digital audiodisk, an optical memory disk or the like. |
