Metallic substrate treatment methods and articles comprising a phosphonate functionalized layer

Patent metadata

Field	Value
Publication number	US-12018380-B2
Application number	US-201917433312-A
Country	US
Kind code	B2
Filing date	Dec 18, 2019
Priority date	Mar 1, 2019
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

Metallic substrate treatment methods and articles comprising a phosphonate functionalized layer are provided. The method comprises contacting a metallic substrate comprising at least one of aluminum and an aluminum alloy with a fluid to form a phosphonate functionalized layer on at least a region of the metallic substrate. The fluid comprises at least one of a phosphonate containing acid and a derivative thereof. At least one of the phosphonate containing acid and the derivative thereof comprises a pKa of a first acidic proton. The fluid comprises a pH at least 0.5 pH value greater than the pKa of the first acidic proton. The article comprises a metallic substrate comprising aluminum or an aluminum alloy and a phosphonate functionalized layer on at least a region of the metallic substrate.

First claim

What is claimed is:

1. A metallic substrate treatment method comprising:
contacting a metallic substrate comprising at least one of aluminum and an aluminum alloy with a fluid to form a phosphonate functionalized layer on at least a region of the metallic substrate, the fluid comprising at least one of a phosphonate containing acid and a derivative thereof,
wherein the at least one of the phosphonate containing acid and the derivative thereof comprises a pKa of a first acidic proton, and wherein the fluid comprises a pH in a range of 5.5 to 8.5 and at least 0.5 pH value greater than the pKa of the first acidic proton,
wherein the fluid comprises 0.1 weight percent to 20 weight percent, based on the total weight of the fluid, of the at least one of the phosphonate containing acid and derivative thereof.

2. The method of claim 1 , wherein the fluid comprises a pH at least 2 pH values greater than the pKa of the first acidic proton.

3. The method of claim 1 , wherein the fluid comprises a pH in a range of 6.5 to 8.5.

4. The method of claim 1 , wherein the phosphonate containing acid is at least one of phosphorous acid, phenylphosphonic acid, ethylphosphonic acid, octylphosphonic acid, octadecylphosphonic acid, vinylphosphonic acid, vinylphosphonic acid dimethyl ester, diethylenetriaminepentakis(methylphosphonic acid), octane diphosphonic acid, and derivatives of each such compound.

5. The method of claim 1 , wherein the at least one of the phosphonate containing acid and the derivative thereof has the formula

wherein R 1 , R 2 , and R 3 are individually selected from hydrogen, an alkyl, and an aryl.

6. The method of claim 1 , wherein the fluid comprises 0.2 weight percent to 10 weight percent, based on the total weight of the fluid, of the at least one of the phosphonate containing acid and derivative thereof.

7. The method of claim 1 , wherein contacting the metallic substrate comprises at least one of immersing the metallic substrate in a bath of the fluid, spraying the fluid onto the metallic substrate, and wiping the fluid onto the metallic substrate.

8. The method of claim 7 , wherein contacting the metallic substrate comprises immersing the metallic substrate in a bath of the fluid and further comprises agitating the bath of fluid using at least one method selected from the group consisting of bubbling gas through the fluid in the bath and stirring the fluid in the bath.

9. The method of claim 1 , wherein the fluid contacts the metallic substrate for a time in a range of 1 second to 40 minutes.

10. The method of claim 1 , wherein the phosphonate functionalized layer comprises a phosphonate group bonded to the metallic substrate.

11. The method of claim 1 , wherein an International Commission on Illumination L*a*b* lightness difference (ΔL*) between the metallic substrate comprising the phosphonate functionalized layer and the metallic substrate without the phosphonate functionalized layer is no greater than 10, as measured with a BYK-Gardner Spectro Guide 45/0 Spectrophotometer.

12. The method of claim 1 , further comprising, prior to contacting the metallic substrate:
cleaning the metallic substrate, wherein cleaning comprises at least one of an alkaline cleaning, an acid cleaning, and a carbon dioxide based cleaning technique.

13. The method of claim 1 , further comprising depositing a coating layer over at least a portion of the phosphonate functionalized layer on the metallic substrate.

14. The method of claim 13 , wherein the coating layer comprises at least one of a siloxane, a silazane, a fluoropolymer, an acrylic, an epoxy, a polyester, and a polyurethane.

Assignees

• Howmet Aerospace Inc

Inventors

• Scott Ryan N
• Robare Kevin M
• Giocondi Jennifer L
• Menegazzo Nicola
• Weiler Kelly M

Classifications

• C23G1/22

  Light metals · CPC title

• C23G1/125

  aluminium · CPC title

• C23C22/76

  Applying the liquid by spraying · CPC title

• C23C22/73

  characterised by the process · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title