| 摘要 |
PURPOSE:To obtain an optical material which is excellent in clarity, heat resistance, moisture resistance and mechanical strengths and scarcely causes birefringence when molded. CONSTITUTION:Bisphenols of formula I [where X is an (aryl-substd.) straight- chain or branched alkylene, cycloalkylene, -O-, -S-, -SO-, -SO2-; n is 0, 1; R<1-2> are each a halogen, alkyl, alkoxy, aryl; l and m are each 0-3) and bisphenols of formula II (where X' is X; n' is n; R<3-4> are each R<1>; l' and m' are each 0-4), in a molar ratio of 10:1-1:10, are dissolved in a solvent (e.g., methylene chloride), and the soln. is submitted to an interfacial polycondensation by introducing thereto a phosgene gas at 0-40 deg.C to give an optical material consisting of a polycarbonate copolymer contg. recurring units of formulas III and IV. |
