| 摘要 |
PURPOSE:To obtain the titled copolymer of small photoelastic constant outstanding in mechanical properties, heat resistance and transparency, useful for optical information recording discs etc., by using as the dihydric phenolic components, a specific dihydric phenolic compound and bisphenol M. CONSTITUTION:The objective copolymer with a viscosity-average mol.wt. of pref. 13,000-50,000 constituted of recurring units of formulas I and II, respectively, with the molar ratio of the unit I to the unit II being 1:99-99:1. It is suggested that this copolymer be obtained by e.g. ester interchange process using diphenyl carbonate to bring 1,1-bis(4-hydroxy-3-t-butylphenyl)-1-phenylethane of formula III and bisphenol M of formula IV to carbonate linkage. |
