PROCEDE DE PRODUCTION D'ACIDE TEREPHTALIQUE DE QUALITE POUR FIBRES

摘要

A process for producing fiber grade terephthalic acid by subjecting p -xylene to a liquid phase oxidation with oxygen or an oxygen-containing gas in the presence of an oxidation catalyst comprising cobalt, manganese and bromine and in the presence of a lower aliphatic carboxylic acid solvent, said catalyst comprising: (a) the amount of cobalt is in the range of 0.05 - 0.50 percent by weight based on the solvent, (b) the amount of the manganese is in the range of 1 - 20 percent by weight based on cobalt, (c) the source of bromine is cobalt bromide, free bromine, or a mixture thereof, and (d) the weight ratio of bromine to cobalt is in the range of 1.5:1 - 6.0: 1. Terephthalic acid thus obtained can be used as a raw material of direct polymerization with glycols for providing high quality polyester.