Binder mixtures for two-component polyurethane coating compositions

US6001931A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Martin Brahm · Siegen, DE
• Dieter Margotte
• Christian Wamprecht · Neuss, DE
• Wieland Hovestadt · Leichlingen, DE
• Jurgen Meixner · Krefeld, DE

Key dates

• Filing date: Aug 10, 1992
• Grant date: Dec 14, 1999
• Expiry date: Aug 10, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G18/7831
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to binder mixtures for two-component polyurethane coating compositions which dry at room temperature and contain PA1 a) a polyisocyanate component, PA1 b) a hydroxy-functional polyacrylate component based on a mixture of at least two hydroxyl group-containing poly(meth)acrylate resins PA2 i) having a molecular weight (M.sub.n) of 1000 to 100,000, PA2 ii) having an at least bimodal molecular weight distribution, PA2 iii) prepared by radical copolymerization of olefinically unsaturated monomers in a solvent using monomer mixtures containing less than 50% by weight of monomers carrying hydroxyl groups and PA2 iv) wherein the hydroxyl group content of the component having the lowest molecular weight is at least 1.5 times the hydroxyl group content of the component having the highest molecular weight, PA1 c) optionally reactive diluents, wherein components a) and b) are present in an amount which corresponds to an NCO/OH equivalent ratio of 0.2:1 to 5:1.