Patent ID: 6268528
Filing Date: 2001-07-31
Classification: C07C

Abstract:
A method of producing naphthalenedicarboxylic acid, which comprises the steps of:oxidizing dialkylnaphthalene to naphthalenedicarboxylic acid at 160 to 240.degree. C. in a solvent containing a lower aliphatic carboxylic acid using a molecular oxygen-containing gas in the presence of a catalyst comprising a cobalt compound, a manganese compound and a bromine compound to obtain an oxidation product mixture, andsubjecting said oxidation product mixture to a solid-liquid separation to obtain crystals of naphthalenedicarboxylic acid and a mother liquor when a concentration of naphthalenedicarboxylic acid in said oxidation product mixture is 8 to 30% by weight,an atomic ratio of manganese to cobalt of said catalyst being 0.03 to 0.5, and said catalyst being supplied to an oxidation reaction zone so that a total of cobalt and manganese is 0.025 to 0.1 gram atom based on 1 gram atom of said dialkylnaphthalene, and wherein a compound capable of forming bromide ions is added to said oxidation product mixture prior to said solid-liquid separation.