| 摘要 |
PURPOSE:An optical information material having excellent transparency and small optical strain and suited for excellent optical disc bases, comprising a specified polycarbonate. CONSTITUTION:An optical information material comprising a polycarbonate in which units containing at least one pendant aromatic group, for example, units of formula I (wherein X and Y are each H, a 1-6C aliphatic hydrocarbon or an aromatic hydrocarbon group, at least one of which is an aromatic hydrocarbon, and Z and W are each H or a 1-6C aliphatic hydrocarbon) are incorporated in carbonate bond-constituting units in an amount of 25-100wt%, based on the total carbonate bond-constituting units. An example of the comonomer unit which may be contained is that of formula II (wherein X', Y', A and B are each H or a 1-6C aliphatic hydrocarbon). This optical information material has excellent transparency and small optical strain, so that it can yield excellent disc bases. |
