Water-based two layer coating systems based on urethane, the use thereof and substrates coated with them

US8299164B2 · kind B2 · utility

Assignee

• BASF COATINGS GMBH · DE

Inventors

• Anne Fickers · Hachenburg, DE
• Heinz-Peter Rink · Hachenburg, DE
• Andreas Dopp · Kohlenbissen, DE

Key dates

• Filing date: Apr 30, 2008
• Grant date: Oct 30, 2012
• Expiry date: Nov 15, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L75/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Disclosed is an aqueous clearcoat material for producing a waterborne urethane-based two-coat coating system, comprising at least one secondary polyacrylate dispersion having a polyacrylate glass transition temperature Tg≧20° C. and at least one hybrid polyacrylate-polyurethane dispersion with a weight ratio of the polyacrylate fraction of the secondary dispersion to the polyacrylate-polyurethane fraction of the hybrid dispersion of 1:1 to 4:1, and as curing agent at least one low-viscosity aminosulfonic polyisocyanate and an aqueous basecoat material for producing a waterborne two-coat coating system comprising at least one polyurethane dispersion, at least one hybrid polyacrylate-polyurethane dispersion, and at least one melamine resin. Also disclosed are a waterborne two-coat coating system comprising the clearcoat material and the basecoat material, a process for producing it, its use to coat a substrate, and substrates coated with it.