METHOD FOR PRODUCING AQUEOUS SOLUTION OF NAPHTHOHYDROQUINONE COMPOUND AND RADICAL-TRAPPING AGENT AQUEOUS SOLUTION

摘要

PROBLEM TO BE SOLVED: To provide a method for producing the aqueous solution of a naphthohydroquinone compound insignificant in the content of coloring ingredients and reduced in coloring deterioration due to storage.;SOLUTION: The method for producing the aqueous solution of the naphthohydroquinone compound is characterized by sequentially comprising an addition reaction process for mixing a solution (A) obtained by dissolving naphthoquionone in an organic solvent dissolving the naphthoquinone and substantially insoluble in water, with an aqueous solution (B) of hydrogen sulfite or hydrogen carbonate, a separation process for separating a naphthohydroquinone compound-containing aqueous phase from an organic solvent phase, and a solvent-removing agent process for removing the solvent existing in the separated and recovered aqueous solution of the naphthohydroquinone compound, further including a decoloration process for treating the aqueous solution of the naphthohydroquinone compound with an adsorbing agent at an arbitrary position after the addition reaction process, maintaining dissolved oxygen concentrations at ≤5 ppm in the solutions and the aqueous solutions in the addition reaction process, the separation process and the solvent-removing agent process, and adding an oxidation-preventing agent or a reducing agent as a stabilizer in one of the processes.;COPYRIGHT: (C)2011,JPO&INPIT