Polyurethane powder lacquers for coatings with matt appearance

摘要

Polyurethane powder lacquer comprising: (a) 3-25 wt.% polyurea; (b) 35-75 wt.% of a polyester derived from polyols and polycarboxylic acids and/or their esters and/or anhydrides, but less than 15 mole% succinic acid or anhydride, and having a hydroxyl number of 5-250 mg KOH/g and a m.pt. of 50-130degreesC; (c) 5-30 wt.% of a hardener based on blocked polyisocyanates, isocyanurates and/or uretdiones with a functionality of at least 2; and (d) 0.5-50 wt.% additives. Component (c) provides 0.5-1.2 isocyanate groups per hydroxy group of component (b). An Independent claim is also included for matt coatings comprising the powder lacquer.