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:
Apr. 07, 1981
Filed:
Sep. 10, 1979
Horst-Dieter Thamm, Kelkheim, DE;
Volker Knittel, Wiesbaden, DE;
Werner Sommer, Sulzbach, DE;
Gerhard Weckler, Sulzbach, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Novel phosphonocarboxylic acid compounds having the formula ##STR1## wherein the radicals R which may be identical or different and which represent alkyl radicals with 1-18 carbon atoms which may be optionally substituted by halogen, hydrogen, alkali metal ions or ammonium ions, are prepared by reacting methylene phosphonic acid alkyl esters with acrylic acid esters in the presence of strongly basic catalysts at temperatures of about 0.degree.-140.degree. C., and by possibly trans-esterifying the reaction products or by submitting the latter to acid or basic hydrolysis. The acid hydrolysis to yield the free 3,3-diphosphono-pimelic acid is best carried out with at least the about 6-fold molar quantity of a carboxylic acid such as HCOOH, CH.sub.3 COOH, etc., optionally in the presence of catalytic quantities of strong acids or bases, at elevated temperatures. The compounds of formula (I), wherein the radicals R represent only alkyl radicals which may possibly be substituted by halogen, are valuable plasticizers for polyvinyl chloride, the compounds of formula (I), wherein R=H, alkali metal ions and/or ammonium ions, are valuable gypsum setting retardants and complex-forming agents for metal ions.