Patent ID: 9273210
Filing Date: 2016-03-01
CPC Classification: B27K,C08G,C08L,C09D,Y10T

Claim Text:
1. A method for coating a wood surface, comprising applying an aqueous preparation to the wood surface; wherein the aqueous preparation comprises: ≧20 weight-% to ≦50 weight-% of a hydroxyl-functional polyurethane-polyacrylate dispersion, ≧20 weight-% to ≦50 weight-% of a polyurethane dispersion comprising a hydroxyl-functional polyurethane, ≧5 weight-% to ≦20 weight-% of an at least partially hydrophilicized polyisocyanate and ≧0 weight-% to ≦10 weight-% of a matting agent, wherein the combined hydroxyl content of the hydroxyl-functional polyurethane-polyacrylate dispersion and the polyurethane dispersion is ≧1% to ≦12%, and wherein the hydroxyl-functional polyurethane-polyacrylate dispersion is a polyurethane-polyacrylate hybrid secondary dispersion prepared by a process comprising: preparing a polyurethane solution (A) having an average molecular weight M adding to the polyurethane solution (A), one or more vinylically unsaturated monomers (B) at least one selected from the group consisting of (B1) acid-functional monomers, (B2) hydroxyl- and/or amino-functional monomers, and (B3) other monomers different from (B1) and (B2), to form a mixture, subjecting the mixture to free-radical polymerization in a homogeneous, non-aqueous phase to provide a hybrid polymer, neutralizing at least one neutralizable group, and dispersing the hybrid polymer into the aqueous phase, wherein the neutralization can take place before or after the vinyl polymerization or during the dispersing step.