PROCESS FOR PRODUCING TEREPHTHALIC ACID WITH HIGH PURITY

摘要

Terephthalic acid with a high purity and high whiteness is produced by oxidizing p-tolualdehyde with molecular oxygen such as air in the presence of a heavy metal catalyst of manganese and/or cerium, a bromine compound, and a mineral acid in water as a solvent at a bromine compound concentration of 0.5-12% by weight on the basis of the reaction solution in terms of bromine ions and at a ratio of g-equivalents of hydrogen ions of the mineral acid to sum total of g-equivalents of the hydrogen ions and manganese and/or cerium ions of 1-85% and at a ratio of sum total of g-equivalents of the hydrogen ions and manganese and/or cerium ions to g-equivalents of bromine ions of 0.5-5. Terephthalic acid thus produced is directly polymerizable with glycols without any purification.