Binder composition and its use for coating metallic and mineral substrates

摘要

The present invention relates to a solvent-free, low viscosity binder composition which contains, in amounts sufficient to provide an NCO:OH equivalent ratio of 0.5:1 to 2.0:1, A) a polyisocyanate component containing one or more organic polyisocyanates and B) a solvent-free polyhydroxy component having a hydroxyl group content of 3.0 to 18 wt. % and a viscosity at 23 DEG C. of 200 to 10,000 mPa.s, which contains B1) a hydroxy-functional polyacrylate component which is prepared by polymerizing a mixture of olefinically unsaturated monomers in which at least one monomer is hydroxy-functional in the presence of B2) a compound containing ether groups and having one or more hydroxy groups. The invention also relates to the use of this binder composition in solvent-free two-component polyurethane coating compositions for coating metallic or mineral substrates.