The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1981
Filed:
Jul. 20, 1978
Klaus Sommer, Heidelberg, DE;
Hermann Weber, Hemsbach, DE;
Benckiser-Knapsack GmbH, Ladenburg am Neckar, DE;
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.