Patent ID: 7919552
Filing Date: 2011-04-05
Classification: C08G,C09D

Abstract:
1. Polyurethane powder lacquer, containing A) a binder component comprising one or more hydroxyfunctional compounds present in solid form below 40° C. and in liquid form above 130° C., with an OH number of 15 to 200 mg KOH/g, a number average molecular weight of 40 to 10,000 and a total content of carboxyl groups (calculated as COOH; molecular weight=45) of up to 2.0 wt. %, B) one or more polyaddition compounds comprising uretdione groups and optionally free isocyanate groups and based on aliphatic and/or cycloaliphatic diisocyanates, wherein the one or more polyaddition compounds has a minimum content of carboxylic acid ester groups (calculated as CO C) one or more monoalcohols present in solid form below 23° C. and in liquid form above 125° C., D) one or more curing catalysts suitable for accelerating the reaction of uretdione groups with hydroxyl groups, E) optionally a component comprising one or more compounds with a number average molecular weight of 200 to 5000 and having groups reactive to carboxyl groups, and F) optionally auxiliary substances and additives known from powder lacquer technology, wherein the components A), B) and C) are present in such quantitative amounts that 0.8 to 2.2 isocyanate groups of the component B) are available for each hydroxyl group of the components A) and C), the components A) and optionally E) are present in such quantitative amounts that 0.8 to 2.0 groups of the component E) that are reactive to carboxyl groups are available for each carboxyl group of the component A), the proportion of the component C) in the total amount of the components A) to F) is from 1 to 10 wt. %, and the proportion of the component D) in the total amount of the components A) to F) is 0.05 to 5 wt. %.