| 摘要 |
1489547 Preparation of terephthalic acid MITSUBISHI CHEMICAL INDUSTRIES Ltd 25 June 1976 [25 June 1975] 26493/76 Heading C2C The invention comprises a process for the preparation of terephthalic acid by liquid phase oxidation of p-xylene in acetic acid with a free oxygen containing gas at a temperature of 205-225‹ C. in the presence of a catalyst consisting of (a) a, cobalt compound present in an amount, calculated as cobalt, of 200-600 p.p.m. based on the solvent, (b) a manganese compound present in an amount by weight, calculated as manganese, of from 0À5 to 1À5 times that of cobalt, and (c) at least one bromine compound selected from HBr, manganese bromide and cobalt bromide present in an amount, calculated as bromine, of from 400- 2000 p.p.m. based on the solvent. When cobalt and/or manganese bromide provide the bromine compound they can also be used to provide the Co and/or Mn compound. |
