Process for producing high purity isophthalic acid
US5132450A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1991 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Jun 25, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/265
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for producing isophthalic acid by oxidation of m-xylene with an oxygen-containing gas in a hydrous acetic acid solvent in the presence of a cobalt/manganese/bromine system catalyst, the process being capable of industrially advantageously producing high-purity isophthalic acid having excellent whiteness, the process comprising (1) a step of carrying out an oxidation reaction in a main oxidation reactor under specified ranges of a catalyst concentration, a reaction temperature and an oxygen concentration in a discharge gas such that the concentration of 3-carboxybenzaldehyde becomes 500 to 10,000 ppm, (2) a step of further carrying out an oxidation reaction in a post oxidation reactor such that the concentration of 3-carboxybenzaldehyde becomes 100 to 800 ppm, separating crude isophthalic acid, evaporating remaining mother liquor and recovering acetic acid, and (3) mixing the crude isophthalic acid with purified acetic acid, stirring the resultant mixture at 100.degree. C. or higher, and separating purified isophthalic acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.