Preparation of polycondensates of citric acid and use thereof in detergents and cleaners

US5652330A · kind A · utility

Assignee

• BASF SE

Inventors

• Dieter Boeckh · Schifferstadt, DE
• Angelika Funhoff · Schriesheim, DE
• Alexander Kud · Eppelsheim, DE
• Richard Baur · Mutterstadt, DE
• Volker Schwendemann · Neustadt, DE
• Gunnar Schornick · Neuleiningen, DE

Key dates

• Filing date: Aug 16, 1995
• Grant date: Jul 29, 1997
• Expiry date: Aug 16, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C11D3/3757
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Process for preparing polycondensates of citric acid and/or isocitric acid, by converting PA1 (a) citric acid, isocitric acid or mixtures thereof in an organic solvent in the presence of a water-withdrawing agent at least partially into the anhydride form and then condensing the reaction mixture, if desired after addition of two cocondensable compounds selected from the group consisting of PA1 (b) other hydroxycarboxylic acids and/or PA1 (c) amino acids, alcohols, amines and/or at least dibasic carboxylic acids other than carboxylic acids (a) and (b), at temperatures of at least 80.degree. C. to form polycarboxylates which have an average molecular weight of at least 500, polycondensates of citric acid and/or isocitric acid obtainable thereby, and use of said polycondensates as ingredients in phosphate-free and reduced-phosphate detergents and cleaners, and also detergents and cleaners which contain at least one surfactant and optionally builders and other customary constituents with from 0.1 to 30% by weight of an abovementioned polyestercarboxylate.