POLYCARBONATES AND METHOD OF PREPARING SAME
    3.
    发明公开
    POLYCARBONATES AND METHOD OF PREPARING SAME 审中-公开
    聚碳酸酯和方法

    公开(公告)号:EP2074160A2

    公开(公告)日:2009-07-01

    申请号:EP07797583.7

    申请日:2007-05-18

    IPC分类号: C08G64/00

    CPC分类号: C08G64/307 C08G64/04

    摘要: Polycarbonates incorporating terminal carbonate groups derived from ester-substituted activated carbonates, for example terminal methyl salicyl carbonate (TMSC) derived from the use of BMSC as the activated carbonate in a transesterification process, have unfavorable properties with respect to color, hydrolytic stability and thermal stability, particularly when the polycarbonate containing such end groups is molded. The number of activated carbonate end groups formed during the melt transesterification formation of polycarbonate can be reduced, however, without sacrificing the benefits of using an activated diaryl carbonate, and without requiring a separate reaction or additional additives by reacting a dihydroxy compound with an activated diaryl carbonate in the presence of an esterification catalyst to produce a polycarbonate, wherein the molar ratio of activated diaryl carbonate to dihydroxy compound is less than 1 when expressed to at least three decimal places, for example 0.996 or less.