N-Carboxy alkyl amino alkane polyphosphonic acids

US4307038A · kind A · utility

Assignee

• Benckiser-Knapsack GmbH · DE

Inventors

• Klaus Sommer · Heidelberg, DE
• Hermann Weber

Key dates

• Filing date: Jul 20, 1978
• Grant date: Dec 22, 1981
• Expiry date: Jul 20, 1998

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/3808
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Novel N-carboxy alkyl amino alkane polyphosphonic acids which have more than two carbon atoms in their carboxy alkyl group, and their alkali metal salts are prepared in a good yield by reacting alkali metal salts of amino alkane phosphonic acids in which at least one hydrogen atom of the amino group is unsubstituted, in an alkaline medium with an .alpha., .beta.-unsaturated carboxylic acid at increased temperature. The free acids are preferably recovered from the reaction solution by a treatment with a cation exchange agent. In place of the .alpha., .beta.-unsaturated carboxylic acids there can also be used their anhydrides, esters, or nitriles. The resulting polyphosphonic acids have a good complexing or sequestering effect on polyvalent metal ions.