Process of protecting metal substrates with corrosion-resistant compositions

Patent metadata

Field	Value
Publication number	US-2016102209-A1
Application number	US-201514971427-A
Country	US
Kind code	A1
Filing date	Dec 16, 2015
Priority date	Jan 21, 2011
Publication date	Apr 14, 2016
Grant date	—

Abstract

This invention relates to galvanic aluminum alloy powder-pigments coated with semi-conducting corrosion-inhibiting compositions and particularly to the process for preparing said coated powder-pigments for coating substrates to inhibit corrosion. The coated aluminum alloy powder-pigments are electrically active and prevent corrosion of metals which are more cathodic (electropositive) than the coated-aluminum alloy pigments.

First claim

The invention claimed:

1 . A process for protecting a metal substrate from corrosion which comprises coating said metal substrate with up to about 10 mils of an electrochemically corrosion-resistant composition comprising in parts by weight, from about
5 to 80 parts of a film-forming binder, and from about 20 to 80 parts of a galvanic aluminum alloy powder-pigment prepared in an atmosphere selected from the group consisting of oxygen, nitrogen-inert gas and nitrogen-hydrogen and has a particle size ranging from about 2 to 100 microns; said aluminum alloy powder-pigment coated with an effective amount of a semi-conducting corrosion-inhibiting coating, and has the formula Aluminum-X—Y wherein X is an element selected from the group consisting of zinc, cadmium, magnesium, barium, and manganese and Y is an element selected from the group consisting of indium, gallium, tin and bismuth.

2 . The process of claim 1 wherein the aluminum alloy powdered-pigment is coated with an effective amount of semi-conducting corrosion-inhibiting coating derived from an acidic aqueous solution consisting essentially of from about
0.01 to 22 parts of a trivalent chromium compound, from about
0.01 to 12 parts of a hexafluorozirconate, from about,
0.01 to 12 parts of at least one fluorometallate selected from the group consisting of tetrafluoroborates, hexafluorosilicates, and hexafluorotitanates, from about
0.0 to 12 parts of at least one divalent zinc compound, and from about 0.00 to 5 parts by weight of a water soluble corrosion inhibitor.

3 . The process of claim 2 wherein said pigment is prepared in an atmosphere of oxygen.

4 . The process of claim 2 wherein said pigment is coated with an aqueous solution having a pH ranging from about 2.5 to 5.5.

5 . The process of claim 2 wherein said pigment has a particle size ranging from about 20 to 40 microns.

6 . The process of claim 2 wherein the fluorometallate in said corrosion-resistant composition is an alkali metal tetrafluoroborate.

7 . The process of claim 2 wherein the hexafluorozirconate is an alkali metal hexafluorozirconate.

8 . The process of claim 2 wherein the corrosion inhibitor is selected from the group consisting of an inorganic talcite clay, benzimidazole, benzothiazole, benzoxazole, diphenyltriazole, benzotriazole, and tolyltriazole.

9 . The process of claim 2 wherein the corrosion-resistant composition comprises a film-forming binder selected from the group consisting of polyurethanes, polyimides, polyacrylates, and polymers derived from diisocyanates, polymers derived from epoxies and the uncured prepolymers of said polymers.

10 . The process of claim 2 wherein the corrosion inhibitor is talcite clay and the aluminum alloy powder-pigment has the formula Aluminum-Zinc-Indium.

11 . The process of claim 9 wherein the film-forming binder comprises a polyurethane.

12 . The process of claim 9 wherein the film-forming binder comprises polymers derived from epoxies.

13 . The process of claim 9 wherein the film-forming binder comprises uncured prepolymers of said polymers.

14 . The process of claim 8 wherein the powder-pigment has the formula Aluminum-Zinc-Tin and the corrosion inhibitor is an azole compound.

15 . The process of claim 2 wherein the corrosion-resistant composition comprises an effective amount of at least one stabilizing compound selected from the group consisting of carboxylic compounds, polyhydroxy compounds and mixtures of said compounds.

16 . The process of claim 15 wherein the stabilizing compound is a polyhydroxy compound.

Assignees

• Matzdorf Craig
• Nickerson William
• Us Navy

Inventors

• Matzdorf Craig
• Nickerson William

Classifications

• C23C4/04

  characterised by the coating material · CPC title

• C23C4/123

  Spraying molten metal · CPC title

• C23C4/06

  Metallic material · CPC title

• C23C4/00

  Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge (build-up welding B23K, e.g. B23K5/18, B23K9/04) · CPC title

• C09D5/084 Primary

  Inorganic compounds · CPC title