Mitsui Toatsu Chemicals, Incorporated

Tomonori Ito

Akihiro Yamaguchi

Masakatsu Nakatsuka

Yoshiyuki Totani

Motokazu Hirao

Masahiro Ohta

Takashi Kuroki

Shoji Obuchi

Yukiko Mori

Ken-Ichi Goto

1. A method for preparing an aromatic polycarbonate having less content of a low molecular weight oligomer which comprises the steps of: (A) conducting an interfacial polymerization reaction in a reaction system comprising at least one aromatic dihydroxy compound, a carbonate precursor, an alkali metal or alkaline earth metal base, water and an organic solvent in the absence of an endcapping agent, and (B) conducting an interfacial polymerization reaction with the addition of an endcapping agent after at least one of the following parameters reaches a predetermined value: (1) a weight-average molecular weight of a prepolymer obtained in step A, (2) a residual amount of the aromatic dihydroxy compound which is contained in the reaction mixture obtained in step A, (3) an amount ratio of a bishaloformate compound to a prepolymer wherein the bishaloformate compound is a bishaloformate derivative of a dihydroxy compound and is contained in the reaction mixture obtained in step A.

Method for preparing an aromatic polycarbonate

A process for producing an aromatic polycarbonate by reacting an aromatic dihydroxy compound, an alkali or alkaline earth metal base and a carbonyl halide compound comprises feeding a polymerization catalyst as the carbonyl halide is fed to a mixture of the aromatic dihydroxy compound, the alkali metal or alkaline earth metal, water and an organic solvent. The molecular weight of the aromatic polycarbonate can be properly controlled, the rate of end capping is high, and coloration of the aromatic polycarbonate is less. Such aromatic polycarbonate can be produced while suppressing hydrolysis of the carbonyl halide compound and/or haloformate compound.

Aromatic polycarbonate and process for production thereof

A process for producing continuously an aromatic polycarbonate oligomer by reacting an aromatic dihydroxy compound and an alkali metal base or an alkaline earth metal base with a carbonyl halide compound comprises:

Processes for producing aromatic polycarbonate oligomer and aromatic

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Yokohama, Japan

Tomonori Ito