Aminomethylenephosphonic acid solutions
AssigneeMonsanto Company
InventorsMichel A. O. Ledent, Bronislav H. May
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Abstract
Aqueous solutions of aminomethylenephosphonic acid selected from diethylenetriaminepenta(methylenephosphonic acid), diethylenetriaminetetra(methylenephosphonic acid), diethylenetriaminetri(methylenephosphonic acid) and mixtures thereof are stabilized against crystallization of said aminomethylenephosphonic acid by including non-oxidizing mineral acid in such solutions in an amount stoichiometrically equivalent to at least 10% hydrochloric acid by weight of the solution.
Claims8
An aqueous solution comprising an aminomethlenephosphonic acid selected from diethylenetriaminepenta-(methylenephosphonic acid), diethylenetriaminetetra(methylenephosphonic acid), diethylenetriaminetri(methylenephosphonic acid) and mixtures thereof and a non-oxidizing mineral acid, characterized in that said non-oxidizing mineral acid is present in an amount sufficient to inhibit crystallization of said aminomethylene-phosphonic acid from the solution, said non-oxidizing mineral acid comprising sulfuric acid, phosphoric acid, hydrobromic acid, and mixtures containing sulfuric acid, phosphoric acid or hydrobromic acid which non-oxidizing mineral acid is at least about 12% by weight of the solution.
Dependencies are inferred from the claim text.