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...
Gespeichert in:
Hauptverfasser: | , , , |
---|---|
Format: | Patent |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
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 |
---|