Coating system for aluminum-magnesium alloys

Patent metadata

Field	Value
Publication number	US-11248125-B2
Application number	US-201815939345-A
Country	US
Kind code	B2
Filing date	Mar 29, 2018
Priority date	Jun 1, 2017
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A coating system may be configured to be applied to an aluminum-magnesium substrate of an object. The coating system may include a primer configured to reduce the corrosion rate of the aluminum-magnesium substrate and a topcoat configured to resist water and improve solar reflectance of the coating system. The primer may include a silicate and a first additive configured to increase corrosion resistance of the coating system The topcoat may include a siloxane and a second additive configured to reduce solar absorptance of the coating system.

First claim

What is claimed is:

1. A coating system disposed on an aluminum-magnesium substrate of an object, the coating system comprising:
a primer in the form of an insoluble film and configured to reduce the corrosion rate of the aluminum-magnesium substrate, the primer comprising a silicate, and a plurality of first additives configured to increase corrosion resistance of the coating system, wherein the plurality of first additives includes cerium (III) phosphate in powder form, a dibasic ester, 3-glycidyloxypropyltriethoxysilane, and polyethyleneimine; wherein the polyethyleneimine and the silicate define a co-continuous polymer network, wherein the silicate is covalently coupled to the polyethyleneimine via the 3-glycidyloxypropyltriethoxysilane and wherein the silicate has a reduced tendency to crack upon drying by virtue of being incorporated into the co-continuous polymer network; and
a topcoat configured to resist water and improve solar reflectance of the coating system, the topcoat comprising a siloxane and a second additive configured to reduce solar absorptance of the coating system.

2. The coating system of claim 1 , wherein the silicate is potassium silicate.

3. The coating system of claim 1 , wherein the primer comprises 30% to 60% of the silicate by weight of the primer.

4. The coating system of claim 1 , wherein the siloxane is polydimethylsiloxane.

5. The coating system of claim 1 , wherein the topcoat comprises 30% to 60% of the siloxane by weight of the topcoat.

6. The coating system of claim 1 , wherein the primer further comprises any one of zinc oxide, or a silane.

7. The coating system of claim 1 , wherein the primer further comprises methyltrimethoxysilane or dimethyldimethoxysilane.

8. The coating system of claim 1 , wherein the second additive is calcium carbonate.

9. The coating system of claim 1 , wherein the primer comprises from 0.1% to 10% of the polyethyleneimine by weight of the primer.

10. The coating system of claim 1 , wherein the primer comprises from 0.1% to 5% of the 3-glycidyloxypropyltriethoxysilane by weight of the primer.

11. The coating system of claim 1 , wherein the primer comprises 0.1% to 2% of the cerium (III) phosphate by weight of the primer.

12. The coating system of claim 1 , wherein the primer has a ratio between 3-glycidyloxypropyltriethoxysilane and polyethyleneimine from 0.4 to 1.

13. A coating system configured to be applied to an aluminum-magnesium substrate of an object, the coating system comprising:
a primer configured to reduce the corrosion rate of the aluminum-magnesium substrate, the primer comprising (i) a silicate, (ii) cerium (III) phosphate in powder form, (iii) a dibasic ester, (iv) zinc oxide, (v) 3-glycidyloxypropyltriethoxysilane, (vi) methyltrimethoxysilane or dimethyldimethoxysilane, and (vii) polyethyleneimine; wherein the polyethyleneimine forms a co-continuous polymer network with the silicate via the 3-glycidoxypropyltrimethoxysilane that covalently couples the silicate to the polyethyleneimine, and wherein the silicate has a reduced tendency to crack upon drying by virtue of being incorporated into the co-continuous polymer network; and
a topcoat configured to resist water and improve solar reflectance of the coating system, the topcoat comprising a siloxane and a second additive configured to reduce solar absorptance of the coating system.

14. The coating system of claim 13 , wherein the primer further comprises glycerol and fumed silica.

15. The coating system of claim 14 , wherein the primer consists of (i) a silicate, (ii) cerium (III) phosphate in powder form, (iii) a dibasic ester, (iv) zinc oxide, (v) 3-glycidyloxypropyltriethoxysilane, (vi) methyltrimethoxysilane or dimethyldimethoxysilane, (vii) polyethyleneimine, (viii) glycerol, and (ix) fumed silica; wherein the primer has a ratio between 3-glycidoxypropyltrimethoxysilane and polyethyleneimine from 0.4 to 1.

16. The coating system of claim 15 , wherein the primer is disposed onto the aluminum-magnesium substrate and is provided in a dried state.

Assignees

• Univ Johns Hopkins

Inventors

• Benkoski Jason J
• Hoffman Jr Christopher M
• Srinivasan Rengaswamy
• Caruso Keith S

Classifications

• C09D7/60

  non-macromolecular (C09D7/41-C09D7/48 take precedence) · CPC title

• C09D7/65

  macromolecular (C09D7/41-C09D7/48 take precedence) · CPC title

• C09D5/002 Primary

  Priming paints (C09D5/08 takes precedence) · CPC title

• C09D5/004

  Reflecting paints; Signal paints · CPC title

• C09D1/02

  alkali metal silicates · CPC title