首页>
外国专利>
Purification process of ethylenediaminetetra(methylenephosphonic) acid or 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methylenephosphonic)acid
Purification process of ethylenediaminetetra(methylenephosphonic) acid or 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methylenephosphonic)acid
In the present invention there is disclosed a purification process of ethylenediaminetetra(methylenephosphonic) acid of the general formula (A) or 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methylenephosphonic) acid of the general formula (B), which purification process comprises the following stages: (a) dissolving aminophosphonic acid in aqueous solution of ammonium hydroxide, (b) addition of the solution obtained in the stage (a) in the acid solution, (c) cooling this solution down to a temperature ranging from 20 degC to 95 degC after carrying out the preceding stages, provided this solution has been warmed up, and leaving this solution at the above specified temperature for a period of about 1 to 24 hours to ensure precipitation of the aminophosphonic acid, (d) filtering off crystals of the aminophosphonic acid, a (e) rinsing these crystals with water.
展开▼
