improvements to processes for the preparation of isophthalic acid or acid terephtalique by catalytic oxidation of meta - and para xylene

摘要

ISO- OR TEREPHTHALIC PREPARATION IN A BENZOIC ACID-WATER SOLVENT SYSTEM The present invention relates to the preparation of iso- or terephthalic acid by the oxidation of m- or p-xylene with molecular oxygen at elevated temperatures and under liquid phase conditions in the presence of catalysis provided by a combination of one or more transition metal oxidation catalysts and a source of bromine improved by the use of a liquid solvent system consisting essentially of benzoic acid and at least 3 percent and up to about 15 percent by weight of water which provides commercially feasible control of oxidation temperature not otherwise feasible in the absence of the water component of said catalyst system when said xylenes are oxidized.