PROCESS FOR PRODUCING HIGH-PURITY DIPHENYL CARBONATE ON AN INDUSTRIAL SCALE

摘要

It is an object of the present invention to provide a specific process that enables a high-purity diphenyl carbonate required for producing a high-quality high-performance aromatic polycarbonate to be produced industrially in a large amount (e.g. not less than 1 ton / hr) stably for a prolonged period of time (e.g. not less than 1000 hours, preferably not less than 3000 hours, more preferably not less than 5000 hours) from a cyclic carbonate and a phenol. When producing, from a cyclic carbonate and a phenol, a high-purity diphenyl carbonate required for producing a high-quality high-performance aromatic polycarbonate, the above object can be attained by carrying out a process according to the present invention which comprises steps of: (I) producing a dialkyl carbonate and a diol using a reactive distillation column having a specified structure; (II) producing a diphenyl carbonate using two reactive distillation columns each having a specified structure, and (III) obtaining a high-purity diphenyl carbonate from the diphenyl carbonate using a high boiling point material separating column A and a diphenyl carbonate purifying column B.