ACCELERATING AGENT FOR PHOSPHATE CHEMICAL CONVERSION COATING AND MANUFACTURING METHOD THEREFOR, AND METAL NITRITE SOLUTION AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an aqueous metal nitrite solution as an accelerating agent for phosphate chemical conversion coating, while controlling the formation of impurities. SOLUTION: The method for manufacturing the accelerating agent for the phosphate chemical conversion coating including the aqueous metal nitrite solution comprises the steps of: preparing the metal salt solution (a hydroxide or carbonate solution or the like) containing a metal included in the phosphate chemical conversion coating; introducing nitrous acid gas into the above metal salt solution; and introducing an oxidation inhibitor (for instance, nitrogen gas) for preventing the oxidation of the above nitrous acid gas into the above metal salt solution. COPYRIGHT: (C)2004,JPO