| 摘要 |
PROBLEM TO BE SOLVED: To provide an aromatic polycarbonate containing less amount of transparent foreign matters, and excellent in transparency and molded appearance by an ester interchange method. SOLUTION: The method for producing the aromatic polycarbonate by passing a polymer molten liquid formed by the ester interchange reaction of an aromatic dihydroxy compound with a diester compound of carbonic acid in the presence of a catalyst, through a leaf-disk type polymer filter heated to a temperature higher than or equal to the melting temperature, and pelletizing the resultant polymer is characterized in that sulfur-containing acidic compound is added so as to neutralize the catalyst remaining in the polycarbonate, and the number of the transparent foreign matters having the largeness larger than or equal to the absolute filtering accuracy is regulated so as to be≤5 pieces per gram of polycarbonate by heating the leaf disk in an inert atmosphere before passing the molten liquid of the polymer through the polymer filter. COPYRIGHT: (C)2008,JPO&INPIT
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