Process for the reduction of heavy metal ions in excess from aqueous synthesis solutions of water soluble heavy metal complex dyestuffs

US4963660A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Uwe Mrotzeck · Kelkheim, DE
• Peter Mischke
• Gunther Schwaiger · Frankfurt, DE
• Werner Russ · Flörsheim, DE
• Manfred Sittig · Kriftel, DE

Key dates

• Filing date: Aug 30, 1988
• Grant date: Oct 16, 1990
• Expiry date: Aug 30, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B45/01
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

Free radical heavy metal ions in water-soluble heavy metal complex dyestuffs are removed from the synthesis solution of the heavy metal complex dyestuff by means of a compound or several of the compounds mentioned below: PA0 (a) saturated and unsaturated fatty acids having about 8 to 18 carbon atoms and water-soluble salts thereof; PA0 (b) the monoesters and diesters of orthophosphoric acid and salts thereof corresponding to the general formula (1a) and (1b) ##STR1## in which R denotes a saturated or unsaturated aliphatic radical having about 8 to 18 carbon atoms and M stands for a hydrogen atom or a salt-forming, water-solubilizing metal; PA0 (c) aliphatic sulfonic acids and water-soluble salts thereof corresponding to the general formula (2) EQU R--SO.sub.3 M (2) PA0 in which R and M have the abovementioned meanings; PA0 (d) aliphatic phosphonic acids and monoesters thereof and also water-soluble salts thereof corresponding to the general formulae (3a) and (3b) ##STR2## in which R and M have the abovementioned meanings; (e) malonic acid and water-soluble salts thereof; PA0 (f) trimercapto-s-triazine, 2-aminobenzoic acid, 8-hydroxyquinoline and water-soluble salts of these compoun…