| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for continuously and industrially advantageously producing pyromellitic acid in oxidizing 2,4,5-trimethylbenzaldehyde or its oxidized derivative in a liquid phase by developing a highly active catalyst. SOLUTION: 2,4,5-Trimethylbenzaldehyde or its oxidized derivative is subjected to liquid-phase oxidation in the presence of a catalyst containing bromine, manganese and iron or further zirconium and cerium by using 10-90 wt.% of acetic acid solvent. Preferably bromine ion concentration in the solvent is 0.05-2 wt.%, the whole heavy metal atom concentration of manganese, iron, zirconium and cerium in the solvent is 0.03-2 wt.% and the ratio of the whole heavy metal atom concentration to the bromine ion is in the range of 0.5-15. |
