Method for the secondary cross-linking of hydrogels with N-acyl-2-oxazolidinones

US6559239B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Ulrich Riegel · Landstuhl, DE
• Matthias Weismantel · Bad Orb, DE
• Volker Frenz · Hochheim, DE
• Thomas Daniel · Waldsee, DE
• Fritz Engelhardt · Frankfurt am Main, DE

Key dates

• Filing date: May 29, 2001
• Grant date: May 6, 2003
• Expiry date: May 29, 2021

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2333/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Liquid-absorbent polymers are prepared by a process for the gel and/or surface postcrosslinking of water-absorbent polymers by the polymer being treated with a surface postcrosslinking solution and being postcrosslinked and dried during and after the treatment by raising the temperature, wherein the surface postcrosslinking solution comprises as crosslinker a compound of the formula I whereR1, R2, R3 and R4 are independently hydrogen, C1-C12-alkyl, C1-C12-alkenyl, C6-C12-aryl or C1-C12-alkoxy,R5 is C1-C16-alkyl, C1-C4-hydroxyalkyl, C6-C12-aryl, C1-C16-alkenyl or a group of the formula —(CH2)n—COOH or —(CH2)n—SO3H in the form of the acid or a respective metal salt, ammonium salt or triethanolammonium salt thereof or —(CH2—CH2—O—)m—R6,R6 is hydrogen or C1-C16-alkyl,n is from 1 to 10,m is from 1 to 20dissolved in an inert solvent,and are used in hygiene articles, packaging materials and nonwovens.