| 摘要 |
PROBLEM TO BE SOLVED: To provide a citric acid aluminum salt and its complex salt comprising an aluminum compound of citric acid, easily soluble in water, useful as a surface treating agent for metals, a surface treating agent for the electrode of an electrolytic capacitor, an electrolyte for the capacitor, a dyeing assistant, industrial chemicals, etc., and having excellent effect and provide a method for producing the salt. SOLUTION: Citric acid is added to an aqueous solution of an aluminum salt, calcium hydroxide or barium carbonate, etc., is added to the mixture to form a water-insoluble sulfate and the product is separated from the solution. The solution containing the remaining aluminum citrate is concentrated and crystallized by cooling or subjected to concentration to dryness, spray drying, etc., to obtain a solid product. An alkali metal such as potassium hydroxide is added to an aqueous solution of an aluminum salt until the pH of the solution becomes 4-5, citric acid is added to the separated basic aluminum to form a solution of citric acid aluminum salt and its complex salt and the citric acid aluminum salt and its complex salt are obtained by a method similar to the method described above. COPYRIGHT: (C)2006,JPO&NCIPI
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