| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a high-purity alkali metal hydroxide, wherein the alkali metal hydroxide is purified by removing heavy metals therefrom while keeping it in a highly concentrated state. <P>SOLUTION: As a result of our ardent study to remove heavy metals from an alkali metal hydroxide in such a high concentration region as to be usual in commercial products, it has been found out that the heavy metals can be removed from the alkali metal hydroxide by treatment with an amidino-containing ion exchange resin. The amidino-containing ion exchange resin is exemplified by one represented by formula (1): A-C(=NR<SB>1</SB>)-NHR<SB>2</SB>(wherein A is a styrene resin; R<SB>1</SB>is a hydrogen atom, a hydroxyl group, or a 1-3C alkyl group; and R<SB>2</SB>is a hydrogen atom, a hydroxyl group, or a 1-3C alkyl group). <P>COPYRIGHT: (C)2008,JPO&INPIT |
