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US 5,667,845 AGranted
Treatment to improve corrosion resistance of autodeposited coatings on metallic surfaces
AssigneeHenkel Corporation
InventorsOscar E. Roberto, Shawn E. Dolan
Life of this patent
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Abstract
A process enhances corrosion resistance of autodeposited coatings on metallic surfaces by contacting the uncured coating on the metallic surface with a reaction rinse solution containing complex fluoride anions. In a preferred use, because the protective properties of the autodeposited coatings are improved on both cold rolled and galvanized steel, both may be processed simultaneously, providing practical and economic advantages.
Claims21
A process for providing a metal substrate surface with a protective coating containing an organic binder, said process comprising steps of:
- (A) contacting a metal substrate surface with a liquid autodeposition composition containing dispersed organic binder for a sufficient time to form a wet adherent film on the surface of said metal substrate wherein said wet adherent film includes said organic binder deposited from the autodeposition composition;
- (B) separating the substrate bearing the wet adherent film formed in step (A) from further contact with the autodeposition composition and contacting the wet adherent film with an aqueous liquid rinse solution comprising
- (1)) water;
- (2) anions wherein said anions consist of (i) at least four fluorine atoms and (ii) at least one atom of an element selected from the group consisting of titanium, zirconium, hafnium, silicon, and boron and, optionally, (iii) one or more oxygen atoms;
- and
- (3) a stoichiometric amount of counterions for said anions;
- said solution including only non-chromium-containing materials thereby raising no disposal problems created by the use of chromium-containing compounds;
- and
- (C) separating the substrate bearing the wet adherent film as modified by the contacting of step (B) from the aqueous liquid rinse solution used in step (B) and subsequently drying the wet film into place on the substrate to produce a dry film.
6 more elements
A process, of providing a metal substrate surface with a protective coating containing an organic binder, said process comprising steps of
- (A) contacting a metal substrate surface with a liquid autodeposition composition containing dispersed organic binder for a sufficient time to form a wet adherent film on the surface of said metal substrate wherein said wet adherent film includes said organic binder deposited from the autodeposition composition;
- (B) separating the substrate bearing the wet adherent film formed in step (A) from further contact with the autodeposition composition and contacting the wet adherent film with an aqueous liquid rinse solution comprising
- (1) water;
- (2) anions wherein said anions consists of (i) at least four fluorine atoms and (ii) at least one atom of an element selected from the group consisting of titanium, zirconium, hafnium, silicon and optionally, (iii) one or more oxygen atoms;
- and
- (3) counterions,
- (C) separating the substrate bearing the wet adherent film as modified by the contacting of step (B) from the aqueous liquid rinse solution used in step (B) and subsequently drying the wet film into place on the substrate to produce a dry film, wherein the aqueous liquid rinse solution contains a total of about 0.002 moles per liter of solution to about 1.0 moles per liter of solution of said anions and said ions are selected from the group consisting of fluoborate, fluosilicate, fluotitanate, and fluozirconate anions and wherein said solution includes only non-chromium-containing materials thereby raising no disposal problems created by the use of chromium-containing compounds.
4 more elements
A process for providing a metal substrate surface with a protective coating containing an organic binder, said process comprising steps of
- (A) contacting a metal substrate surface with a liquid autodeposition composition containing dispersed organic binder for a sufficient time to form a wet adherent film on the surface of said metal substrate wherein said wet adherent film includes said organic binder deposited from the autodeposition composition;
- (B) separating the substrate bearing the wet adherent film formed in step (A) from further contact with the autodeposition coating and contacting the wet adherent film with an aqueous liquid rinse solution;
- (C) separating the substrate bearing the wet adherent film as modified by the contacting of step (B) from the aqueous liquid rinse solution used in step (B) and subsequently drying the wet film into place on the substrate to produce a dry film;
- wherein said aqueous liquid rinse comprises
- (1) water;
- and
- (2) fluozirconate ions in an amount of from 0.002 moles per liter to about 1.0 mole per liter and,
- (3) cobalt counterions,
- said aqueous liquid rinse solution including only non-chromium-containing materials thereby raising no disposal problems created by the use of chromium-containing compounds.
6 more elements
Dependencies are inferred from the claim text.