METAL PRETREATMENT COMPOSITION CONTAINING ZIRCONIUM, COPPER, AND METAL CHELATING AGENTS AND RELATED COATINGS ON METAL SUBSTRATES

摘要

Disclosed is a zirconium-based metal pretreatment coating composition that includes a metal chelator that chelates copper in the metal pretreatment coating composition and thereby improves adhesion of paints to a metal substrate coated with the pretreatment coating composition. The pretreatment coating composition has a longer pot life than one without the metal chelator and therefore can accommodate a wide latitude of application times. The chelating agent is present in a sufficient amount to ensure that in the deposited pretreatment coating on the metal substrate the average total atomic % of copper to atomic % of zirconium is equal to or less than 1.1. The pretreatment coating composition is useful for treating a variety of metal substrates.