METHOD FOR PRODUCING AROMATIC POLYCARBONATE

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a polycarbonate of excellent quality by eliminating a difficulty in controlling a mole balance of starting materials used in melt polymerization. SOLUTION: The method for producing an aromatic polycarbonate is one comprising blendin...

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Bibliographische Detailangaben
Hauptverfasser: SHIMONARI MASASHI, SAWAKI TORU, SASAKI KATSUJI, MATSUOKA YUKI
Format: Patent
Sprache:eng
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Zusammenfassung:PROBLEM TO BE SOLVED: To provide a method for efficiently producing a polycarbonate of excellent quality by eliminating a difficulty in controlling a mole balance of starting materials used in melt polymerization. SOLUTION: The method for producing an aromatic polycarbonate is one comprising blending and melting a carbonic diester and a pneumatically conveyed powdery aromatic diydroxy compound under conditions in which the variation width is within at most ±0.005 in the range in which the molar ratio of the aromatic dihydroxy compound to the carbonic diester is 1 to (1.00-1.10) and polycondensing the melt in the presence of a transesterification catalyst, wherein the aromatic dihydroxy compound used is one which is in the form of flakes or prills having an angle of repose of 35-50° and shows an increment in an angle of repose of at most 10° after the pneumatic conveying. COPYRIGHT: (C)2003,JPO