| 摘要 |
PURPOSE:The titled substrate, obtained by using a polycarbonate consisting of specific bisphenol constituent units, etc., under mild conditions and having improved transparency and small optical strain. CONSTITUTION:A substrate obtained by molding a polycarbonate consisting of (A) 60-100wt% carbonate bonding constituent units expressed by formula I (Y and Z are H or 1-6C aliphatic hydrocarbon; X and W are 1-6C aliphatic hydrocarbon) and, as necessary, (B) carbonate bonding constituent units expressed by formula II (Y' and Z' are H or 1-100C hydrocarbon). For example, a bisphenol compound, e.g. 2,2-bis(4-hydroxy-3-methylphenyl)propane and, as necessary, another diol compound, e.g. bisphenol A, are (co)polymerized normally in an inert solvent, e.g. methylene chloride, in the presence of an acid acceptor, e.g. triethylamine, at 0-100 deg.C while introducing phosgene thereinto the produce a polycarbonate having preferably 12,000-22,000 average molecular weight, which is then molded to afford the aimed substrate. |
