Zinc pigments for anti-corrosive powder coatings
STANDART® Zinc Flake AT and STANDART® Zinc Flake GTT are platelet pigments consisting of metallic zinc, providing excellent corrosion protection properties for powder coating primers.
Apart from offering cathodic corrosion protection, they provide – due to their lamellar structure – an additional barrier effect in the powder coating film, resulting in a significantly reduced permeability to corrosive agents.
For formulating powder coating primers the platelet zinc pigments Zinc Flake AT and Zinc Flake GTT are normally combined with other anti-corrosive pigments. Particularly combinations with other platelet substrates (e. g. with micaceous iron or aluminium pigments) as well as with spherical inorganic or metallic substances such as iron/zinc phosphates (silicates or zirconates) or zinc dust have been successfully proved in practice.
For the production of zinc-based powder coating primers, Zinc Flake AT or Zinc Flake GTT (10%–15%) are added with the other anti-corrosive pigments (40%– 60%) at the premix stage, followed by extruding, grinding and sieving.