Corrosion resistant conversion coatings
AssigneeDeft, Inc.
InventorEric Morris
Life of this patent
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Abstract
A conversion coating composition for coating a metal substrate is provided which imparts corrosion resistance to the underlying metal substrate. The conversion coating composition comprises an aqueous carrier and first and second rare earth element salts. A complete coating system employing the conversion coating composition is also provided as well as methods for conversion coating a metal substrate with the rare earth element conversion coating compositions of the present invention.
Claims31
A composition for coating a metal substrate comprising an aqueous carrier and first and second salts, each salt comprising an anion and a cation, the anion of the first and second salts being different, and the cation of the first and second salts being the same or different, wherein each cation, individually, is a rare earth element, and the first and second salts in combination are present in the composition in an amount effective to form a corrosion resistant coating on the metal substrate.
A composition for coating a metal substrate comprising water, an oxidizing agent, and first and second salts, wherein the first and second salts in combination are present in the composition in at least about 0.04 weight percent, and wherein each salt comprises at least two different anions of the same rare earth element cation.
A composition for coating a metal substrate comprising a plating bath having the dissolution products from one or more rare earth element oxides and an acid generating compound, wherein at least one dissolution product from a rare earth element oxide is present in the plating bath in an amount effective to form a corrosion resistant coating on the metal substrate.
A metal substrate coating comprising:
- a) a conversion coating prepared from a composition having first and second salts, each salt comprising an anion and a cation, the anion of the first and second salts being different, and the cation of the first and second salts being the same or different, wherein each cation, individually, is a rare earth element, and the first and second salts in combination are present in the composition in an amount effective to form a corrosion resistant coating on the metal substrate;
- and
- b) a primer coat.
A metal substrate coating comprising:
- a) a conversion coating prepared from a composition having first and second salts, each salt comprising an anion and a cation, the anion of the first and second salts being different, and the cation of the first and second salts being the same or different, wherein each cation, individually, is a rare earth element, and the first and second salts in combination are present in the composition in an amount effective to form a corrosion resistant coating on the metal substrate;
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- b) a self-priming top-coat or an enhanced self-priming topcoat.
A method of coating a metal substrate comprising:
- a) providing a metal substrate having a surface;
- b) contacting the metal substrate with a composition, the composition comprising an oxidizing agent and first and second salts, each salt comprising an anion and a cation, the anion of the first and second salts being different, and the cation of the first and second salts being the same or different, wherein each cation, individually, is a rare earth element, and the first and second salts, in combination, are present in the composition in at least about 0.04 weight percent;
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- c) oxidizing at least one rare earth element cation, thereby resulting in the formation of a rare earth element oxide coating, a rare earth element hydroxide coating, or mixture thereof, at or near the surface of the metal substrate.
Dependencies are inferred from the claim text.