Process for separating and purifying alkali metal salts of hydroxynaphthalenecarboxylic acids

摘要

The present invention provides a process for separating and purifying alkali metal salts of hydroxynaphthalenecarboxylic acids, in which alkali metal salt(s) of hydroxynaphthalenecarboxylic acid(s) are separated and purified from a mixture of alkali metal salts of hydroxynaphthalenecarboxylic acids by treating it with a nonionic porous synthetic adsorbent using water or water and water-soluble organic solvent(s).