Soluble corrosion resistant sol-gel

Patent metadata

Field	Value
Publication number	US-10926237-B2
Application number	US-201816226992-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Feb 2, 2018
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Aspects described herein generally relate to a sol-gel that is the reaction product of an organosilane, a metal alkoxide, an acid, and chromium (III) salt and/or a lanthanide salt having a solubility of about 1 gram or greater per gram of sol-gel at 23° C. The lanthanide salt includes a cation and a ligand. The cation can be lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium, cobalt, calcium, strontium, barium, and zirconium. A ligand can be a nitrate, a trifluoromethane sulfonate, a sulfate, a phosphate, a hydroxide, or hydrate forms thereof. The chromium (III) salt includes a cation and a ligand. The cation is chromium (III) and the ligand can be a nitrate, a trifluoromethane sulfonate, a sulfate, a phosphate, a hydroxide, or hydrate forms thereof.

First claim

What is claimed is:

1. A sol-gel comprising:
an organosilane
a metal alkoxide;
an acid;
a chromium (III) salt comprising a ligand selected from a nitrate, a trifluoromethane sulfonate, a sulfate, a phosphate, a hydroxide, or hydrate forms thereof; and
water.

2. The sol-gel of claim 1 , wherein a weight fraction of the chromium (III) salt in the sol-gel is about 0.2 wt % to about 50 wt %.

3. The sol-gel of claim 1 , wherein a ratio of chromium (III) salt to the sum of metal alkoxide, organosilane, and acid is about 0.01:1 to about 0.5:1 by weight.

4. The sol-gel of claim 1 , wherein a ratio of chromium (III) salt to (metal alkoxide+organosilane+acid) is about 1:1 to about 5:1 by weight.

5. The sol-gel of claim 1 , wherein the sol-gel has a solids content of about 1 wt % or less, based on the total weight of the sol-gel.

6. The sol-gel of claim 5 , wherein the sol-gel has a halogen content of about 1 wt % or less, based on the total weight of the sol-gel.

7. The sol-gel of claim 6 , wherein the sol-gel comprises about 80 wt % or greater of water.

8. The sol-gel of claim 6 , wherein the organosilane is represented by Formula (I):

wherein:
each R 1 is independently selected from C 1 -C 20 alkyl; and
R 2 is selected from alkyl, cycloalkyl, ether, and aryl.

9. The sol-gel of claim 6 , wherein the organosilane is represented by Formula (II):

wherein R is selected from alkyl, cycloalkyl, ether, and aryl.

10. The sol-gel of claim 9 , wherein the organosilane is:

11. The sol-gel of claim 1 , wherein the metal alkoxide is selected from zirconium (IV) tetramethoxide, zirconium (IV) tetraethoxide, zirconium (IV) tetra-n-propoxide, zirconium (IV) tetra-isopropoxide, zirconium (IV) tetra-n-butoxide, zirconium (IV) tetra-isobutoxide, zirconium (IV) tetra-n-pentoxide, zirconium (IV) tetra-isopentoxide, zirconium (IV) tetra-n-hexoxide, zirconium (IV) tetra-isohexoxide, zirconium (IV) tetra-n-heptoxide, zirconium (IV) tetra-isoheptoxide, zirconium (IV) tetra-n-octoxide, zirconium (IV) tetra-n-isooctoxide, zirconium (IV) tetra-n-nonoxide, zirconium (IV) tetra-n-isononoxide, zirconium (IV) tetra-n-decyloxide, zirconium (IV) tetra-n-isodecyloxide, or mixtures thereof.

12. The sol-gel of claim 1 , wherein the acid is acetic acid.

13. The sol-gel of claim 1 , wherein a weight fraction of the sum of metal alkoxide, organosilane, and acid in the sol-gel is at least 4 wt %.

14. The sol-gel of claim 13 , wherein the weight fraction is at least 15 wt %.

15. The sol-gel of claim 1 , wherein the chromium (III) salt comprises a sulfate ligand or hydrate form thereof.

16. The sol-gel of claim 15 , wherein the chromium (III) salt is chromium (III) sulfate hexahydrate.

17. The sol-gel of claim 1 , wherein the chromium (III) salt comprises a nitrate ligand or hydrate form thereof.

18. The sol-gel of claim 1 , wherein the chromium (III) salt comprises a trifluoromethane sulfonate ligand or hydrate form thereof.

19. The sol-gel of claim 1 , wherein the chromium (III) salt comprises a phosphate ligand or hydrate form thereof.

20. The sol-gel of claim 1 , wherein the chromium (III) salt comprises a hydroxide ligand or hydrate form thereof.

21. A component comprising:
a metal substrate; and
the sol-gel of claim 1 disposed on the metal substrate.

22. The component of claim 21 , further comprising a secondary layer disposed on the sol-gel.

23. The component of claim 22 , wherein the secondary layer is an epoxy coating or urethane coating.

24. The component of claim 21 , wherein the component is a vehicle component selected from an auxiliary power unit, a nose of an aircraft, a fuel tank, a tail cone, a panel, a coated lap joint between two or more panels, a wing-to-fuselage assembly, a structural aircraft composite, a fuselage body-joint, a wing rib-to-skin joint, or an internal component.

25. The component of claim 21 , wherein the metal substrate comprises a metal selected from aluminum, aluminum alloy, nickel, iron, iron alloy, steel, titanium, titanium alloy, copper, copper alloy, or mixtures thereof.

26. A method of forming a sol-gel, comprising:
mixing a metal alkoxide and an acid to form a first mixture;
mixing with the first mixture an organosilane to form a second mixture; and
mixing a chromium (III) salt with the second mixture to form a third mixture, wherein the chromium (III) salt comprises a ligand selected from a nitrate, a trifluoromethane sulfonate, a sulfate, a phosphate, a hydroxide, or hydrate forms thereof.

27. The method of claim 26 , further comprising depositing the third mixture onto a metal substrate.

28. The method of claim 27 , further comprising curing the third mixture.

29. The method of claim 27 , further comprising cleaning the metal substrate by degreasing, alkaline washing, chemical etching, chemically deoxidizing, and/or mechanically deoxidizing the metal substrate prior to depositing.

30. The method of claim 27 , further comprising depositing a secondary layer onto the sol-gel.

31. The method of claim 26 , wherein the chromium (III) salt comprises a sulfate ligand or hydrate form thereof.

32. The method of claim 31 , wherein the chromium (III) salt is a chromium (III) sulfate hexahydrate.

33. The method of claim 26 , wherein the chromium (III) salt comprises a nitrate ligand or hydrate form thereof.

34. The method of claim 26 , wherein the chromium (III) salt comprises a trifluoromethane sulfonate ligand or hydrate form thereof.

35. The method of claim 26 , wherein the chromium (III) salt comprises a phosphate ligand or hydrate form thereof.

36. The method of claim 26 , wherein the chromium (III) salt comprises a hydroxide ligand or hydrate form thereof.

Assignees

• Boeing Co

Inventors

• Schuette Waynie M
• Kinlen Patrick J

Classifications

• C09D5/084 Primary

  Inorganic compounds · CPC title

• C08G77/58

  Metal-containing linkages · CPC title

• C09D183/14

  in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms (C09D183/10 takes precedence) · CPC title

• C09D7/63

  organic · CPC title

• C08K5/005

  Stabilisers against oxidation, heat, light, ozone · CPC title