Patent ID: 7812189

Claim:
A process for the production of a high-purity diphenyl carbonate, the process comprising the steps of: (i) carrying out a transestrification reaction between a dialkyl carbonate and a phenol and/or a disproportionation reaction of an alkyl carbonate and/or a transesterification reaction between an alkyl phenyl carbonate and a phenol in the presence of a homogeneous catalyst, so as to form a reaction mixture containing a diphenyl carbonate; (ii) carrying out separation by distillation in a high boiling point material separating column A into a column top component A T containing the diphenyl carbonate and a column bottom component A B containing the catalyst (iii) carrying out separation by distillation of said column top component A T in a diphenyl carbonate purifying column B having a side cut outlet into a column top component B T , a side cut component B S and a column bottom component B B , said column top component A T introducing from the side cut outlet into the column B; wherein (a) said high boiling point material separating column A comprises a continuous multi-stage distillation column having a length L A (cm), an inside diameter D A (cm), and an internal with a number of stages n A thereinside, wherein L A , D A , and n A satisfy the following formulae (1) to (3); 800≦L A ≦3000 (1) 100≦D A ≦1000 (2) 20≦n A ≦100 (3); (b) said diphenyl carbonate purifying column B comprises a continuous multi-stage distillation column having a length L B (cm), an inside diameter D B (cm), an internal thereinside, an inlet B 1 at a middle portion of the column, and a side cut outlet B 2 between said inlet B 1 and the column bottom, in which a number of stages of the internal above the inlet B 1 is n 1 , a number of stages n 2 of the internal between the inlet B 1 and the side cut outlet B 2 is n 2 , a number of stages n 3 of the internals below the side cut outlet B 2 is n 3 , and a total number of stages is n B (=n 1 +n 2 +n 3 ), wherein L B , D B , n 1 , n 2 , n 3 , and n B satisfy the following formulae (4) to (9); 1000≦L B ≦5000 (4) 100≦D B ≦1000 (5) 5≦n 1 ≦20 (6) 12≦n 2 ≦40 (7) 3≦n 3 ≦15 (8) 20≦n B ≦70 (9).