Metal pretreatment composition containing zirconium, copper, and metal chelating agents and related coatings on metal substrates
AssigneeHenkel AG & Co. KGaA
InventorsDonald R. Vonk, Edis Kapic, Michael L. Sienkowski
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Abstract
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.
Claims26
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, dissolved copper, optionally including added dissolved Cu, a copper chelating agent, and optionally materials comprising one or more of silicon, boron and yttrium, wherein the composition has a pH that ranges from neutral to pH 4, thereby forming a pretreatment coating on the metal substrate;
- with the proviso that the copper chelating agent is the only organic molecule present in the zirconium-based metal pretreatment coating composition and is present in said 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.
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:
- i. dissolved Zr,
- ii. a source of fluoride,
- iii. a copper chelating agent,
- iv. mineral acid, organic acid and/or an alkaline source such that the composition has an acidic pH,
- v. dissolved copper, optionally including added dissolved Cu;
- and
- vi. optionally materials comprising one or more of silicon, boron and yttrium, and optional added dissolved Cu,
- 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 of at least 10 ppm to at most 2000 ppm;
- 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.
An article of manufacture comprising a coated metal substrate comprising:
- a cold rolled steel metal substrate;
- and deposited on the cold rolled steel metal substrate, a pretreatment coating comprising metal from said substrate, zirconium, oxygen, copper, and optional elements fluorine and carbon;
- wherein the pretreatment coating on the cold rolled steel metal substrate has an average total ratio of atomic % of Cu to atomic % of Zr that is equal to or less than 1.1.
Dependencies are inferred from the claim text.