PROCESS FOR PRODUCING HIGH-PURITY DIARYL CARBONATE ON COMMERICAL SCALE

摘要

This invention provides a specific production process in which a high-purity diaryl carbonate usable as a starting material for a high-quality and high-performance polycarbonate using, as a starting material, a reaction mixture containing an alkyl aryl carbonate produced by transesterification of a dialkyl carbonate with an aromatic monohydroxy compound can be produced on a commercial scale of not less than one ton per hr stably over a long period of time. The above starting material is subjected to transesterification using a reaction distillation column. The high-boiling reaction mixture obtained from a bottom of the reaction distillation column is supplied to three specific continuous multistage distillation columns in the following order: a high-boiling substance separation column A, a diaryl carbonate purification column B, and a medium-boiling substance separation column C, whereby a high-purity diaryl carbonate substantially free from medium-boiling by-products, high-boiling by-products and the like can be obtained as a side-cut component in the purification column B on a commercial scale of not less than one ton/hr stably over a long period of time.