| 摘要 |
Disclosed are polycarbonates which are obtained by preparing a polycarbonate prepolymer through prepolymerization followed by polymerizing it through solid-phase, swollen solid-phase or thin film melt-phase transesterification, and have a remaining monomer content of smaller than 100 ppm, especially a dihydroxy compound content of smaller than 100 ppm, or have an acetone soluble content of at most 3.5 or at most 3.0% by weight, or have a terminal hydroxyl fraction of smaller than 2 or smaller than 15 mol %; and optical materials and blow molding materials comprising the polycarbonate. The polycarbonates contain a reduced amount of impurities such as remaining monomers, oligomers and others and have improved physical properties including impact strength, and these are useful as optical materials and blow molding materials.
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