Acid functional phosphorus-containing polyester powder compositions and powder coatings made therefrom

摘要

The present invention provides storage stable powder compositions comprising one or more acid functional, phosphorus-containing polyester chosen from aromatic polyesters having an acid number of 15 or higher mg KOH/g polyester, aliphatic polyesters having an acid number of 20 or higher mg KOH/g polyester. The acid functional, phosphorus-containing polyester comprises the reaction product of one or more polyacid, one or more phosphorus-containing acid or salt thereof and one or more polyol. Preferably, the one or more polyol reactant contains no ²-hydrogen such as, for example, neopentyl glycol (NPG). The acid functional, phosphorus-containing polyester may comprise all or part of a binder powder composition, such as a coating powder, or it may comprise an additive thereto that imparts improved pigment wetting and corrosion resistance to a binder composition Further, the composition may comprise one or more curing agent, such as hydroxyalkylamide (HAA) or epoxy resin. In addition, the invention provides coated substrates made from the powder composition, such as coated steel, aluminum, pretreated steel, and pretreated aluminum.