| 摘要 |
PROBLEM TO BE SOLVED: To obtain a naphthalenedicarboxylic acid by incorporating a polymeric flocculant in a slurry of the product from oxidation of a dialkylnaphthalene to increase the crystal size of the naphthalenedicarboxylic acid so as to industrially advantageously separate and collect the compound. SOLUTION: This compound is obtained by incorporating a solvent containing a lower aliphatic carboxylic acid (e.g. acetic acid) with a dialkylnaphthalene (e.g. dimethylnaphthalene) and a catalyst comprising a heavy metal compound (e.g. cobalt acetate tetrahydrate, manganese acetate tetrahydrate) and a bromine compound (e.g. aqueous hydrobromic acid solution) followed by introducing an oxygen-contg. gas into the system and then carrying out a reaction pref. at 160-250 deg.C and 5-40 kg/cm2G, and subsequently by adding pref. 0.005-0.3 wt.%, based on the objective compound crystal, of a polymeric flocculant (e.g. sodium polyacrylate, polyacrylamide' Mannich-modified product) to the resulting reaction product slurry followed by agitation and then conducting a solid/liquid separation. |
