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).
摘要:
The present invention provides a method for effectively separating independent hydroxynaphthalene-carboxylic acids by treating a mixture containing various kinds of hydroxynaphthalene-carboxylic acids with nonionic porous synthetic adsorbents having as a basic structure aromatic copolymers mainly composed of styrene and divinyl benzene or methacryl copolymers mainly composed of monomethacrylates and dimethacrylates.