Corrosion-inhibiting sol-gel coating systems and methods

Patent metadata

Field	Value
Publication number	US-10167394-B2
Application number	US-201414554335-A
Country	US
Kind code	B2
Filing date	Nov 26, 2014
Priority date	Nov 26, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Corrosion-inhibiting coating materials comprise a sol-gel and a corrosion-inhibiting compound with at least one disulfide group. The corrosion-inhibiting compound is contained within the sol-gel. Coated and/or laminated structures may include the corrosion-inhibiting coating materials on a metal substrate, and may include a secondary layer (e.g., a paint, etc.) adhered to the coating material opposite the metal substrate. Methods of forming a corrosion-inhibiting sol-gel comprise mixing organo-metallic compounds and the corrosion-inhibiting compound into a sol solution and incubating (e.g., reacting) the sol solution to form the corrosion-inhibiting sol-gel with the corrosion-inhibiting compound contained within the sol-gel. Generally, corrosion-inhibiting coating materials are hexavalent chromium free.

First claim

The invention claimed is:

1. A corrosion-inhibiting coating material bonded to a metal substrate, the coating material comprising:
a corrosion-inhibiting compound that is insoluble in water and is a polymer of 2,5-dimercapto-1,3,4-thiadiazole, wherein the polymer of 2,5-dimercapto-1,3,4-thiadiazole includes at least one disulfide group; and
a zirconium-based sol-gel bonded to the metal substrate, wherein the zirconium-based sol-gel is formed from an aqueous sol solution containing an emulsion of the corrosion-inhibiting compound;
wherein the corrosion-inhibiting compound is contained within the zirconium-based sol-gel.

2. The corrosion-inhibiting coating material of claim 1 , wherein the polymer includes at least one thiol group.

3. The corrosion-inhibiting coating material of claim 1 , wherein the polymer includes a thiolate group.

4. The corrosion-inhibiting coating material of claim 1 , wherein the corrosion-inhibiting coating material further includes 5,5-dithiobis-(1,3,4-thiadiazole-2(3H)-thione).

5. A laminated structure comprising:
a metal substrate; and
the corrosion-inhibiting coating material of claim 1 , bonded to the metal substrate.

6. The laminated structure of claim 5 , wherein the metal substrate is an unplated aluminum alloy.

7. The laminated structure of claim 5 , further comprising a secondary layer of organic material bonded to the corrosion-inhibiting coating material opposite the metal substrate.

8. A method of forming a corrosion-inhibiting sol-gel, the method comprising: mixing an organo-zirconate and a corrosion-inhibiting compound that is insoluble in water to form an aqueous sol solution containing an emulsion of the corrosion-inhibiting compound, wherein the corrosion-inhibiting compound is a polymer of 2,5-dimercapto-1,3,4-thiadiazole, wherein the polymer of 2,5-dimercapto-1,3,4-thiadiazole includes at least one disulfide group; incubating the aqueous sol solution to form the corrosion-inhibiting sol-gel; and coating a metal substrate with the corrosion-inhibiting sol-gel.

9. The method of claim 8 , wherein the mixing includes mixing such that a weight fraction of the organo-zirconate in the aqueous sol solution is at least 0.5% and at most 5%.

10. The method of claim 8 , wherein the mixing includes mixing such that a weight fraction of the corrosion-inhibiting compound in the aqueous sol solution is at least 0.1% and at most 10%.

11. The method of claim 8 , wherein the mixing includes dissolving the corrosion-inhibiting compound in a solvent before mixing with the organo-zirconate.

12. The method of claim 11 , wherein the solvent includes at least one of an ether, a glycol ether, tetrahydrofuran, N-methyl-2-pyrrolidone, and dimethyl sulfoxide.

13. The method of claim 8 , wherein the mixing includes introducing the corrosion-inhibiting compound as a powder to the organo-zirconate.

14. The method of claim 8 , wherein the mixing includes mixing with a high-shear mixer.

15. The method of claim 8 , wherein the polymer includes at least one thiol group.

16. The method of claim 8 , further comprising curing the corrosion-inhibiting sol-gel on the metal substrate.

17. The method of claim 8 , further comprising applying a secondary layer of organic material to the corrosion-inhibiting sol-gel on the metal substrate.

Assignees

• Boeing Co

Inventors

• Kinlen Patrick John
• Lawless Lawrence Michael
• Kutscha Eileen Olga

Classifications

• C09D165/00

  Coating compositions based on macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain (C09D107/00 - C09D157/00, C09D161/00 take precedence); Coating compositions based on derivatives of such polymers · CPC title

• C08L81/04

  Polysulfides · CPC title

• C08K5/56 Primary

  Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond · CPC title

• C09D5/08 Primary

  Anti-corrosive paints · CPC title

• C23C18/00

  Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating · CPC title