Stable, non-chrome, thin-film organic passivates
Storage-stable organic passivate formulations that are essentially chromium-free are provided comprising non-ionic or non-ionically stabilized organic film forming resin; at least one complex fluoride and optionally, dissolved phosphate anions, at least one component comprising vanadium, at least one inorganic oxide in dispersed form; and at least one wax in dispersed form.
1 . A composition useful for passivating a metal surface, said composition comprising:
a) water;
b) at least one complex fluoride of an element selected from the group consisting of Ti, Zr, Hf, Si, Sn, Al, Ge and B;
c) a non-ionic or non-ionically stabilized resin in dispersed form said resin selected from the group consisting of acrylic, polyurethane, vinyl, and polyester resins, and mixtures thereof;
d) optionally, dissolved phosphate anions;
e) optionally, at least one component comprising vanadium;
f) optionally, at least one inorganic oxide in dispersed form;
g) optionally, at least one wax in dispersed form; and
h) optionally, at least one further additive selected from the group consisting of a sequestrant, a wetting agent, a defoamer, and a pH adjusting component;
wherein said composition comprises less than 0.04 wt % chromium.
2 . The composition of claim 1 , wherein the total concentration of the complex fluoride is at least 0.5 g/L and is not more than 100 g/L.
3 . The composition of claim 1 , wherein the at least one complex fluoride is a titanium and/or zirconium complex fluoride.
4 . The composition of claim 1 , wherein said composition is essentially free of chromium, c) comprises a non-ionic or non-ionically stabilized acrylic and/or acrylic copolymer resin in dispersed form, said composition comprising at least one pH adjusting component.
5 . The composition of claim 1 , wherein the composition is essentially free of chromium, comprises dissolved phosphate anions and c) comprises a non-ionic or non-ionically stabilized resin in dispersed form selected from the group consisting of acrylic resins and polyurethane resins, and mixtures thereof.
6 . The composition of claim 1 , wherein the pH of the composition is within a range of from about 1 to about 5 and the composition is storage stable at 100 deg. F. for at least 3 months.
7 . The composition of claim 1 , wherein the composition comprises dissolved phosphate anions and c) comprises a non-ionic or non-ionically stabilized resin in dispersed form selected from the group consisting of acrylic resins and polyurethane resins, and mixtures thereof.
8 . The composition of claim 1 , comprising at least one component that comprises vanadium.
9 . The composition of claim 1 , comprising at least one wax, selected from the group of waxes stable in strong acidic solutions having an average particle size less than about 1 micron and a melting point of from about 50 to about 175 degrees C.
10 . The composition of claim 1 , wherein the concentration of wax ranges from about 0.05 to about 6 weight percent.
11 . A composition useful for passivating a metal surface, said composition comprising:
a) water;
b) 0.05-5 weight % of at least one complex fluoride of an element selected from the group consisting of Ti, Zr, Hf, Si, Sn, Al, Ge and B;
c) a non-ionic or non-ionically stabilized resin in dispersed form, said resin selected from the group consisting of acrylic, polyurethane, vinyl, and polyester resins, and mixtures thereof;
d) optionally, dissolved phosphate anions;
e) 0.1 to 7 weight % of at least one component comprising vanadium;
f) optionally, at least one inorganic oxide in dispersed form;
g) 0.05-20 weight % of at least one wax in dispersed form;
h) optionally, at least one further additive selected from the group consisting of a sequestrant, a wetting agent, a defoamer, and a pH adjusting component;
said composition comprising less than 0.04 wt % chromium.
12 . The composition of claim 11 wherein c) comprises 10 -50 weight % of a non-ionic or non-ionically ionically stabilized resin in dispersed form selected from the group consisting of acrylic resins and polyurethane resins, and mixtures thereof.
13 . The composition of claim 11 , wherein the pH of the composition is within a range of from about 1 to about 5 and the composition is storage stable at 100 deg. F. for at least 3 months.
14 . A process of treating a ferriferous, aluminiferous or zinciferous metal substrate comprising:
optionally, cleaning a surface of said metal substrate to be passivated;
contacting the metal substrate surface to be passivated with a passivating composition for a time sufficient to form a coating on said metal surface, wherein the passivating composition comprises:
a) water;
b) at least one complex fluoride of an element selected from the group consisting of Ti, Zr, Hf, Si, Sn, Al, Ge and B;
c) a non-ionic or non-ionically stabilized resin in dispersed form said resin selected from the group consisting of acrylic, polyurethane, vinyl, and polyester resins, and mixtures thereof;
d) optionally, dissolved phosphate anions;
e) optionally, at least one component comprising vanadium;
f) optionally, at least one inorganic oxide in dispersed form;
g) optionally, at least one wax in dispersed form; and
h) optionally, at least one further additive selected from the group consisting of a sequestrant, a wetting agent, a defoamer, and a pH adjusting component;
said composition comprising less than 0.04 wt % chromium; and
drying said coating on the metal surface.
15 . The process of claim 14 wherein the metal substrate temperature during drying ranges between ambient temperature and 250 degrees F.
16 . The process of claim 14 further comprising the step of coating the metal substrate with a dissimilar metal, thereby creating a metal substrate surface to be passivated, prior to contacting with the passivating composition.
17 . The process of claim 14 wherein the coated metal surface is overcoated with a protective layer comprising at least one organic binder.
18 . The process of claim 14 wherein said composition is essentially free of chromium, comprises dissolved phosphate anions and c) comprises a non-ionic or non-ionically stabilized resin in dispersed form selected from the group consisting of acrylic resins and polyurethane resins, and mixtures thereof.
19 . An article of manufacture comprising:
a metal substrate selected from the group consisting of ferriferous, aluminiferous and zinciferous metals, said ferriferous metal substrate comprising a surface layer of a dissimilar metal selected from the group consisting of aluminiferous and zinciferous metals; and
a passivating coating on at least one surface of said metal substrate, said coating comprising the reaction product of said at least one surface and a composition comprising:
a) water;
b) at least one complex fluoride of an element selected from the group consisting of Ti, Zr, Hf, Si, Sn, Al, Ge and B;
c) a non-ionic or non-ionically stabilized resin in dispersed form said resin selected from the group consisting of acrylic, polyurethane, vinyl, and polyester resins, and mixtures thereof;
d) optionally, dissolved phosphate anions;
e) optionally, at least one component comprising vanadium;
f) optionally, at least one inorganic oxide in dispersed form;
g) optionally, at least one wax in dispersed form; and
h) optionally, at least one further additive selected from the group consisting of a sequestrant, a wetting agent, a defoamer, and a pH adjusting component;
said composition comprising less than 0.04 wt % chromium.
20 . The article of claim 19 wherein the passivating coating on the metal surface is overcoated with a protective layer comprising at least one organic binder.
21 . The process of claim 19 wherein the composition is essentially free of chromium, comprises dissolved phosphate anions and c) comprises a non-ionic or non-ionically stabilized resin in dispersed form selected from the group consisting of acrylic resins and polyurethane resins, and mixtures thereof.