| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing pyromellitic acid by industrially advantageous liquid phase air oxidation from durene in a high yield and with little waste solvent and environmental load, the pyromellitic acid being useful as an intermediate for various kinds of plastics, coatings, and the like. ! SOLUTION: Pyromellitic acid can be produced in a high yield by, when carrying out liquid phase oxidation of durene, separating crystals of reaction products including pyromellitic acid and a mother liquid following oxidation reaction, precipitating dissolved components contained in the mother liquid, pyromellitic acid and/or durene oxidation derivatives by addition of a catalyst metal to the mother liquid followed by separation and removal of the precipitate; and carrying out the reaction by recycling the mother liquid obtained containing heavy metals and bromine into the reactor so that the mother liquid is repeatedly used. ! COPYRIGHT: (C)2014,JPO&INPIT |
