Patent ID: 6583215
Filing Date: 2003-06-24
Classification: B01D,B08B,B44D,C08G,C09D,E04G,Y10T

Abstract:
An aqueous 2-component polyurethane (PU) coating composition wherein the binder comprisesa) a vinyl polymer polyol dispersion, having a hydroxyl number between 10 and 264 mg KOH/g solid resin, an acid value (calculated from the sum of neutralized and non-neutralized acid groups) between 0 and 55 mg KOH/g solid resin, a number-average molecular weight Mn of at least 5000 g/mol and a weight average molecular weight Mw of at least 30,000 g/mol, a glass transition temperature of at least 20Â° C. and an average particle diameter of no greater than 300 nm, which is prepared in the presence of 0.1 to 10.0 wt. %, relative to the sum of the solids contents of polymer polyol and polyisocyanate, of a non-ionic polyether surfactant selected from the group consisting of block polymers of ethylene oxide and propylene oxide of formula (I) â€ƒblock and random ethylene oxide/propylene oxide copolymers based on fatty alcohols, block polymers of formula (III), which can be obtained by polycondensation of propylene oxide and ethylene oxide on ethylene diamine, â€ƒadducts of polyethylene oxide on fatty alcohols and polyether/polyester block polymers, and b) a polyisocyanate having a viscosity at 23Â° C. of no more than 12,000 mPa*s and either a non-hydrophilic or a non-ionically or anionically hydrophilic character, wherein the equivalent ratio of isocyanate groups of component b) to hydroxyl groups of component a) is 0.2:1 to 5:1.