Water-absorbing, cross-linked polymerizates in the form of a foam, a method for the production thereof, and their use

US6455600B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Hans-Joachim Hähnle · Neustadt, DE
• Ulrich Schröder · Bischofswerda, DE
• Martin H. Beck · Amherst, US
• Wolfgang Heider · Neustadt, DE
• Gunnar Schornick · Neuleiningen, DE
• Thomas Anstock · Bad Dürkheim, DE

Key dates

• Filing date: Sep 5, 2000
• Grant date: Sep 24, 2002
• Expiry date: Sep 5, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2300/14
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

A water-absorbing, expanded, crosslinked polymer 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 dispersing fine bubbles of a gas which is inert to free radicals in the polymerizable aqueous mixture, and(II) polymerizing the foamed mixture to form an expanded hydrogel, whereby at least 20 mol % of the monomers (a) which contain acidic groups have been neutralized with tertiary alkanolamines and/or the free acidic groups of the expanded hydrogel have been at least 20 mol % neutralized with at least one alkalolamine after the polymerization, and, where appropriate, adjusting the water content of the expanded polymer to 1-60% by weight, the production thereof and the use thereof in hygiene articles employed to absorb body fluids and …