INDUSTRIAL PROCESS FOR PRODUCTION OF HIGH-PURITY DIARYL CARBONATES

摘要

The invention aims at providing a specific process for producing high-purity diaryl carbonates, which are necessary in producing high-quality and high-performance aromatic polycarbonates, from cyclic carbonates and aromatic monohydroxyl compounds on an industrial scale (e.g., in an amount of one ton or above per hour) stably over a long period (e.g., for 1000 hours or longer, preferably 3000 hours or longer, still preferably 5000 hours or longer). The aim can be attained by a process for producing high-purity diaryl carbonates from cyclic carbonates and aromatic monohydroxyl compounds which comprises the step (I) of producing a dialkyl carbonate and a diol by use of a reaction-distillation column having a specific structure, the step (II) of producing a diaryl carbonate by use of two reaction-distillation columns having specific structures, and the step (III) of purifying the diaryl carbonate.