Carboxyl-functional polyester epoxy resin powder coatings based on 1,3-propanediol

摘要

In accordance with the foregoing, the present invention comprises a polyester epoxy resin powder coating exhibiting improved impact resistance and flexibility, without the loss of other key properties and where the 1,3-PDO modified polyester has lower melt viscosity than polyesters made with 100% neopentyl glycol, which is formed by reacting: a) A carboxyl functional polyester resin formed by reacting one or more aliphatic glycols and one or more polycarboxylic acids and/or anhydrides, wherein 5 to 90% (on a molar basis) of the aliphatic glycol is 1,3-propanediol, in the presence of an esterification catalyst and then endcapping the polyester with an endcapping agent to ensure that the polyester has carboxyl chain ends; and b) An epoxy resin crosslinking agent.