Salt spray-resistant metal-filled infrared reflective coating for aerospace application

Patent metadata

Field	Value
Publication number	US-10844230-B2
Application number	US-201715426635-A
Country	US
Kind code	B2
Filing date	Feb 7, 2017
Priority date	Feb 7, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

The present disclosure relates to highly reflective coating formulations that produce coatings having an average infrared reflectivity ranging from about 75% to about 90% at wavelengths ranging from about 0.5 μm to about 1000 μm, methods for making the coatings and coating mixtures, and substrates comprising such coatings.

First claim

What is claimed is:

1. A method of manufacturing an infrared reflective coating comprising:
combining a predetermined amount of a leafing aluminum pigment with a predetermined amount of a non-polar solvent to yield a leafing aluminum pigment mixture, with the said leafing aluminum pigment having a particle size ranging from about 14 μm to about 17 μm said non-polar solvent present in the leafing aluminum pigment mixture in an amount ranging from about 45 wt % to about 70 wt % of the leafing aluminum pigment mixture;
combining a predetermined amount of an aliphatic amine-containing curing agent with a predetermined amount of a liquid epoxy resin to yield a resin mixture; said liquid epoxy resin present in the resin mixture in an amount ranging from about 15 wt % to about 30 wt % of the epoxy resin mixture, and said amount of aliphatic amine-containing curing agent present in the resin mixture in an amount ranging from about 10 wt % to about 25 wt % of the epoxy resin mixture;
combining the leafing aluminum pigment mixture with the resin mixture at a pigment-to-binder ratio of about 0.1:1.0 to yield a coating mixture;
delivering the coating mixture to a substrate;
curing the coating mixture at room temperature to form an infrared reflective coating;
wherein the infrared reflective coating is configured to comprise an average infrared reflectivity ranging from about 75% to about 90% at wavelengths ranging from about 0.5 μm to about 1000 μm;
wherein the amine-containing curing agent has an amine hydrogen equivalent weight (AHEW) ranging from about 90 to about 150;
wherein the infrared reflective coating mixture is curable at room temperature; and
wherein the non-polar solvent comprises a surface tension ranging from 28 mN/m to 30 mN/m.

2. The method of claim 1 , wherein, in the step of combining a leafing pigment with a predetermined amount of a non-polar solvent, the predetermined amount of the non-polar solvent comprises a predetermined amount of toluene, xylene, hexane, or combinations thereof.

3. The method of claim 1 , wherein, in the step of combining a predetermined amount of an aliphatic amine curing agent with a predetermined amount of liquid epoxy resin, the liquid epoxy resin comprises a predetermined amount of a bisphenol A diglycidyl ether liquid epoxy resin.

4. The method of claim 1 , wherein, in the step of combining a predetermined amount of an aliphatic amine-containing curing agent with a predetermined amount of liquid epoxy resin, the aliphatic amine-containing curing agent comprises a predetermined amount of tetraethylenepentamine, triethylenetetramine or combinations thereof.

5. The method of claim 4 , wherein, in the step of curing, the curing is conducted at room temperature.

6. The method of claim 1 , wherein, in the step of combining a predetermined amount of a leafing aluminum pigment with a predetermined amount of a non-polar solvent, the predetermined amount of the leafing aluminum pigment ranges from about 3 wt % to about 5 wt %.

7. The method of claim 1 , wherein, after the step of combining a predetermined amount of a leafing aluminum pigment with a predetermined amount of the non-polar solvent to yield a leafing aluminum pigment mixture, further comprising:
applying a centrifugal mixer to the leafing aluminum pigment mixture.

8. An infrared reflective coating mixture comprising:
an epoxy resin mixture mixed with a leafing aluminum pigment mixture to yield an infrared reflective coating mixture; said epoxy resin mixture comprising:
a predetermined amount of liquid epoxy resin in an amount ranging from about 15 wt % to about 30 wt % of the epoxy resin mixture combined with a predetermined amount of aliphatic amine-containing curing agent in an amount ranging from about 10 wt % to about 25 wt % of the epoxy resin mixture; and

said a leafing aluminum pigment mixture comprising:
a predetermined amount of leafing aluminum pigment in an amount ranging from about 3 wt % to about 5 wt % of the leafing aluminum pigment mixture, with the leafing aluminum pigment having a particle size ranging from about 14 μm to about 17 μm, said leafing aluminum pigment combined with a predetermined amount of a non-polar solvent, said non-polar solvent present in the leafing aluminum pigment mixture in an amount ranging from about 45 wt % to about 70 wt % of the leafing aluminum pigment mixture;

wherein the infrared reflective coating mixture comprises a pigment-to-binder ratio value of about 0.1:1.0;
wherein the amine-containing curing agent has an amine hydrogen equivalent weight (AHEW) ranging from about 90 to about 150;
wherein the infrared reflective coating mixture is curable at room temperature; and
wherein the non-polar solvent comprises a surface tension ranging from 28 mN/m to 30 mN/m.

9. The infrared reflective coating mixture of claim 8 , wherein the liquid epoxy resin comprises a bisphenol A diglycidyl ether liquid epoxy resin.

10. The infrared reflective coating mixture of claim 8 , wherein the aliphatic amine-containing curing agent comprises a predetermined amount of tetraethylenepentamine.

11. The infrared reflective coating mixture of claim 8 , wherein the aliphatic amine-containing curing agent comprises a predetermined amount of triethylenetetramine.

12. The infrared reflective coating mixture of claim 8 , wherein the leafing aluminum pigment comprises aluminum leafing flakes, said aluminum flakes having a specific gravity ranging from about 1.49 to about 1.65.

13. The infrared reflective coating mixture of claim 8 , wherein the non-polar solvent comprises at least one of: xylene, toluene, or hexane.

14. A highly infrared reflective coating for a substrate outer surface, said infrared reflective coating formed from an infrared reflective coating mixture that is cured, said infrared reflective coating mixture, comprising:
an epoxy resin mixture mixed with a leafing aluminum pigment mixture and an amine-containing curing agent to yield an infrared reflective coating mixture; said epoxy resin mixture comprising:
a predetermined amount of liquid epoxy resin in an amount ranging from about 15 wt % to about 30 wt % of the epoxy resin mixture;

said leafing aluminum pigment mixture comprising:
a predetermined amount of leafing aluminum pigment in an amount ranging from about 3 wt % to about 5 wt % of the leafing aluminum pigment mixture, with the leafing aluminum pigment having a particle size ranging from about 14 μm to about 17 μm;
a predetermined amount of a non-polar solvent in an amount ranging from about 45 wt % to about 70 wt % of the leafing aluminum pigment mixture;

said amine-containing curing agent having an amine hydrogen equivalent weight (AHEW) ranging from about 90 to about 150;
wherein the infrared reflective coating mixture comprises a pigment-to-binder ratio value of about 0.1:1.0;
wherein the leafing aluminum pigment comprises aluminum flakes, said aluminum flakes oriented substantially parallel to one another;
wherein the aluminum flakes provide a substantially continuous metallic flake barrier in the highly infrared reflective coating at a substrate outer surface;
wherein the highly reflective infrared coating has an average infrared reflectivity ranging from about 75% to about 90% over a wavelength range, said wavelength range ranging from about 0.5 μm to about 1000 μm; and
wherein the infrared reflective coating mixture is curable at room temperature.

15. A coated substrate comprising the highly infrared reflective coating of claim 14 .

16. The substrate of claim 15 , wherein the coated substrate has an average infrared reflect

Assignees

• Boeing Co

Inventors

• Babilo Peter
• Russo Giuseppe A

Classifications

• C08G59/5006

  aliphatic · CPC title

• C09D163/00

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• C09D5/004 Primary

  Reflecting paints; Signal paints · CPC title

• C08K2003/0812

  Aluminium · CPC title