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 and 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.

主权项

1. An article of manufacture comprising a coated metal substrate which has been coated according to a method comprising steps of:
a) optionally cleaning a metal substrate; b) applying to the metal substrate a zirconium-based metal pretreatment coating composition comprising water and dissolved Zr, a source of fluoride, a copper chelating agent, optionally materials comprising one or more of silicon, boron and yttrium and optional added dissolved Cu, wherein the composition has a pH in the range of 6.0 to 9.0, thereby forming a pretreatment coating on the metal substrate; wherein the copper chelating agent is present in said zirconium-based metal pretreatment coating composition in an amount sufficient to result in an average total ratio of atomic % of Cu to atomic % of Zr in the pretreatment coating deposited on the metal substrate is equal to or less than 1.1; and c) optionally applying a paint to the metal pretreatment coated metal substrate thereby producing a painted coated metal substrate; wherein the pretreatment coating on the metal substrate comprises Zr and Cu present in amounts such that the average total ratio of atomic % of Cu to atomic % of Zr in the pretreatment coating deposited on the metal substrate is equal to or less than 1.1.