Aqueous polyurethane resin dispersion, processes for its preparation, and its use in aqueous coating compositions

US5552496A · kind A · utility

Assignee

• Herberts Gesellschaft mit beschrankter Haftung · DE

Inventors

• Bettina Vogt-Birnbrich · Solingen, DE
• Hans-Peter Patzschke · Wuppertal, DE
• Werner Lenhard · Wuppertal, DE
• Walter Schubert · Wuppertal, DE

Key dates

• Filing date: Feb 27, 1995
• Grant date: Sep 3, 1996
• Expiry date: Feb 27, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D175/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

An aqueous coating composition which is self-drying or is crosslinked by external agents, processes and dispersions for its preparation and its use. The coating composition comprises: PA1 I) 40 to 100% by weight of a film-former in the form of an aqueous dispersion of one or more polyurethane resins having a number-average molecular mass (Mn) of from 2500 to 1,000,000 and a content of ionic groups, groups which can be converted to ionic groups, and/or hydrophilic groups of from 5 to 200 meq per 100 g of solid resin, and at least one CH-acid group per molecule and a OH-number of 0 to 100, wherein some or all of the Ch-acid groups can be reacted with one ore more compounds which are able to react with at least two CH-acid groups for chain-lengthening, and PA1 II) 60 to 0% by weight of one or more crosslinkers based on compounds which can react with at least two CH-acidic groups, based on formaldehyde condensation resins and/or polyisocyanates containing free or blocked isocyanate groups, the percentages by weight of I) and II) relating to the resin solids content and adding up to 100% by weight, and optionally pigments, fillers, organic solvents and/or conventional coating additives.