Water-absorbing, cellular, cross-linked polymers with improved distribution effect, method for their production and their use

US6750262B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Hans-Joachim Hähnle · Neustadt, DE
• Ulrich Schröder · Bischofswerda, DE
• Wolfgang Heider · Neustadt, DE
• Gunnar Schornick · Neuleiningen, DE
• Thomas Anstock · Bad Dürkheim, DE

Key dates

• Filing date: Sep 4, 2001
• Grant date: Jun 15, 2004
• Expiry date: Sep 4, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K2200/0657
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

Water-absorbing, expanded, crosslinked polymers obtainable by(I) foaming a polymerizable aqueous mixture which comprises(a) monoethylenically unsaturated monomers which contain acidic groups and are optionally neutralized,(b) optionally other monoethylenically unsaturated monomers,(c) crosslinkers,(d) initiators,(e) 0.1-20% by weight of at least one surfactant,(f) optionally at least one solubilizer and(g) optionally thickeners, foam stabilizers, polymerization regulators, fillers and/or cell nucleating agents,where the foaming takes place by dissolving a gas which is inert to free radicals under a pressure of 2-400 bar in the polymerizable aqueous mixture, and then decompressing the latter to atmospheric pressure, and(II) polymerizing the foamed mixture to form an expanded hydrogel and, where appropriate, adjusting the water content of the expanded polymer to 1-60% by weight, process for preparing the water-absorbing, expanded, crosslinked polymers and use of these polymers in sanitary articles employed for absorbing body fluids, in dressing material for covering wounds, as sealing material, as soil improver, as soil substitute and as packaging material.