Powder-form polymers which absorb, even under pressure, aqueous liquids and blood, a method of producing them and their use in textile articles for body-hygiene applications

US5610220A · kind A · utility

Assignee

• Chemische Fabrik Stockhausen GmbH · DE

Inventors

• Helmut Klimmek · Krefeld, DE
• Helmut Brehm · Krefeld, DE

Key dates

• Filing date: Jun 30, 1995
• Grant date: Mar 11, 1997
• Expiry date: Jun 30, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T442/699
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

The invention relates to powdery cross-linked polymers (superabsorbers) capable of absorbing aqueous liquids and blood, which are formed of 55-99.9%-wt. polymerized unsaturated, polymerizable acid-groups-comprising monomers which are neutralized to the extent of at least 25 mol-%, b) 0-40%-wt. polymerized unsaturated monomers copolymerizable with a), c) 0.1-5.0%-wt. of a cross-linking agent, d) 0-30%-wt. of a water-soluble polymer, whereby the weight amounts of a) to d) relate to anhydrous polymers, characterized in that 100 parts of the particle-shaped polymers have been mixed with an aqueous solution consisting of a maximum of 10 parts of an at least 10% phosphoric acid and a) 0.05-0.3 parts of a compound capable of reacting with at least two carboxyl groups and not comprising an alkali-salt-forming group in the molecule, and/or b) 0.05-1 parts of a compound capable of reacting with at least two carboxyl groups and comprising an alkali-salt-forming group in the molecule, and that they have been heated to 150.degree.-250.degree. C. The superabsorbers according to the invention have a high retention capacity, high gel strength and a high absorption under load and can be manufacture…