| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an aqueous piperazinecarbodithioic acid salt solution that is useful as a heavy metal treating agent, suppresses generation of a thiocarbonate as a by-product and prevents generation of a poisonous gas. SOLUTION: In the method for producing a piperazinecarbodithioic acid salt by adding carbon disulfide and an alkali hydroxide to an aqueous solution of piperazine, the addition of the alkali hydroxide in a state in which unreacted carbon disulfide exists in the aqueous solution is carried out in the presence of piperazinecarbodithioic acid in the aqueous solution. Before the total amount of the alkali hydroxide is added, especially preferably carbon disulfide is distilled away and removed and the residual alkali hydroxide is added to the aqueous solution. COPYRIGHT: (C)2008,JPO&INPIT
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