| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject colorless polymer excellent in mechanical properties and having a high quality at a high polymerization rate by allowing the melted polymer to absorb a small amount of an inactive gas by specific method in the course of the polymerization and subsequently further polymerizing the melted polymer under vacuum. SOLUTION: This method for producing an aromatic polycarbonate comprises polymerizing (A) an aromatic dihydroxy compound with (B) a diaryl carbonate in one or more polymerizers by a melt polymerization method. Therein, the melted polymer is allowed to absorb an inactive gas (e.g. nitrogen gas) by the use of an inactive gas absorption installation in the course of the polymerization, and subsequently polymerized under vacuum. the change in the number- average mol.wt. of the melted polymer before and after the absorption of the inactive gas in the course of the polymerization is preferably <=1000. The temperature of the inactive gas absorption installation is preferably 150-350 deg.C, and the pressure P(Pa) preferably satisfies a relation of the inequality: P>4×10<12> Mn<-2.6871> , to the number-average mol.wt. Mn of the melted polymer fed into the inactive gas absorption installation.
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