Hybrid polyester-fluorocarbon powder coating compositions and methods of coating substrates with such compositions

摘要

The present invention provides a hybrid polyester-fluorocarbon powder coating composition, wherein the hybrid polyester-fluorocarbon powder coating composition is a dry blend of a polyester powder coating composition A and a fluorocarbon powder coating composition B; The ester powder coating composition A comprises a first polyester polymer and a curing agent for the first polyester polymer; - the fluorocarbon powder coating composition B comprises a fluorocarbon polymer, a curing agent for this fluorocarbon polymer, a second polyester polymer and a curing agent for this second polyester polymer; The weight ratio of polyester powder coating composition A: fluorocarbon powder coating composition B is in the range of 25:75 to 75:25, and this first polyester polymer has an acid value in the range of 18 to 70 mg KOH/g polymer. and this second polyester polymer is a hydroxyl functional polyester polymer having a hydroxyl value in the range of 70 to 350 mg KOH/g polymer. Furthermore, the present invention provides a method for coating such a hybrid polyester-fluorocarbon powder coating composition on a substrate.