| 摘要 |
In producing polycarbonates through transesterification of a dicarbonate with a dihydroxy compound, a compound having a specific branched structure and serving as a chain terminator, such as 4-(1,1,3,3-tetramethylbutyl)phenol, is added to the reaction system. The polycarbonates produced in the process are molded into optical-disk substrates. The process provides polycarbonates having well-balanced fluidity and impact resistance, without requiring toxic phosgene as the starting material. The optical-disk substrates as obtained by molding the polycarbonates produced in the process have reduced birefringence and improved transcriptional ability.
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