| 摘要 |
Disclosed is a polyurethane powder coating material comprising: A) from 3 to 35% by weight of a polymeric composition comprising: 1. at least one polymer (such as a polyester polyol) and 2. at least one thermoset in an amount of from 0.5 to 50% by weight, based on the sum of 1. and 2., the thermoset being prepared by reaction in the polymer matrix A1) of: a) at least one starting component containing NH2 groups, and b) at least one starting component containing NCO groups, where the components a) and b) have each a functionality of .gtoreq.2, while at least one of them has a functionality of >2 and is present in an amount of from 0.5 to 100% by weight; B) from 15 to 45% by weight of at least one amorphous or crystalline polyester having an OH number of from 10 to 250 mg KOH/g; C) from 7 to 25% by weight of at least one curing agent based on a blocked polyisocyanate, isocyanurate or uretdione having a functionality of at least 1.7; and D) from 1 to 50% by weight of an auxiliary or additive; wherein there are from 0.6 to 1.2 NCO groups of the curing agent C) per OH group of the polymers A) and B). The coating material, when applied to a substrate and baked, forms a matt coating layer.
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