Electrodepositable coating compositions and electrically conductive coatings resulting therefrom

Patent metadata

Field	Value
Publication number	US-11827809-B2
Application number	US-201816956815-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Dec 20, 2017
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

The present invention is directed towards an electrodepositable coating composition comprising a film-forming binder and electrically conductive particles, wherein the electrically conductive particles are present in an amount of at least 25% by weight, based on the total solids weight of the electrodepositable coating composition. The present invention is also directed towards methods of coating a substrate, coatings, and coated substrates.

First claim

What is claimed is:

1. An electrodepositable coating composition comprising:
a film-forming binder, wherein the film-forming binder comprises an ionic salt group-containing, film-forming polymer and a curing agent;
electrically conductive particles; and
an aqueous dispersion medium;
wherein the electrically conductive particles comprise zinc particles present in an amount of at least 80% by weight, based on the total solids weight of the electrodepositable coating composition.

2. The electrodepositable coating composition of claim 1 , wherein the electrically conductive particles further comprise aluminum, magnesium, zinc/aluminum alloy, zinc/tin alloy, or combinations thereof.

3. The electrodepositable coating composition of claim 1 , wherein the zinc comprises surface treated zinc.

4. The electrodepositable coating composition of claim 3 , wherein the surface treatment comprises a silane.

5. An electrodepositable coating composition comprising:
a film-forming binder; and
electrically conductive particles;
wherein the electrically conductive particles are present in an amount of at least 25% by weight, based on the total solids weight of the electrodepositable coating composition;

wherein the electrically conductive particles comprise aluminum particles, and the composition has an aluminum particle to binder weight ratio of at least 3:1.

6. The electrodepositable coating composition of claim 1 , wherein the electrically conductive particle comprises zinc particles, and the composition has a zinc particle to binder weight ratio of at least 2:1.

7. The electrodepositable coating composition of claim 1 , wherein the ionic salt group-containing, film-forming polymer comprises a cationic salt group-containing, film-forming polymer.

8. An electrodepositable coating composition comprising:
a film-forming binder, wherein the film-forming binder comprises an anionic salt group-containing, film-forming polymer and a curing agent;
electrically conductive particles; and
an aqueous dispersion medium;
wherein the electrically conductive particles comprise zinc particles present in an amount of at least 80% by weight, based on the total solids weight of the electrodepositable coating composition.

9. The electrodepositable coating composition of claim 1 , wherein the curing agent comprises an at least partially blocked polyisocyanate, an aminoplast resin, a phenoplast resin, or combinations thereof.

10. The electrodepositable coating composition of claim 1 , wherein the curing agent comprises high molecular weight volatile groups.

11. The electrodepositable coating composition of claim 1 , wherein the electrodepositable coating composition is substantially free of lithium-containing particles.

12. The electrodepositable coating composition of claim 1 , wherein the electrically conductive particles to binder volume ratio is 0.5:1 to 3:1.

13. The electrodepositable coating composition of claim 1 , wherein the electrically conductive particles further comprise non-metal conductive particles.

14. The electrodepositable coating composition of claim 1 , further comprising a rheology modifier.

15. The electrodepositable coating composition of claim 1 , further comprising a corrosion inhibitor.

16. A method of coating a substrate, the method comprising:
electrophoretically applying the electrodepositable coating composition of claim 1 to at least a portion of the substrate to form a coating.

17. The method of claim 16 , further comprising subjecting the coating to curing conditions sufficient to at least partially cure the coating, wherein the curing conditions comprise heating the substrate.

18. The method of claim 17 , wherein heating the substrate comprises heating the substrate to a temperature wherein at least a portion of the binder undergoes pyrolysis.

19. The method of claim 16 , further comprising contacting the substrate with a sealing composition after the electrodepositable coating composition is electrophoretically applied to the substrate.

20. The method of claim 16 , further comprising contacting the substrate with a metallic conditioning composition before the electrodepositable coating composition is electrophoretically applied to the substrate.

21. The method claim 16 , further comprising applying a film-forming composition having a pigment-to-binder ratio greater than the pigment-to-binder ratio of the electrodepositable coating composition prior to electrophoretically applying the electrodepositable coating composition.

22. An at least partially coated substrate coated by the method of claim 16 .

23. The at least partially coated substrate of claim 22 , further comprising a first metal-rich coating layer underneath the coating resulting from electrophoretically applying the electrodepositable coating composition of claim 1 , the first metal-rich coating layer having a pigment-to-binder ratio greater than the pigment-to-binder ratio of the coating layer resulting from electrophoretically applying the electrodepositable coating composition of claim 1 .

Assignees

• Ppg Ind Ohio Inc

Inventors

• Zawacky Steven R
• Puodziukynaite Egle
• Milanak Jr Stephen L
• Sandala Michael G
• Donnelly John T
• Dedomenic Corey J
• Sylvester Kevin T
• Nguyen Minh An Thi
• Oakes Landon J
• Okerberg Brian C
• Moretti Ross A

Classifications

• C09D5/448 Primary

  characterised by the additives used (C09D5/4403 - C09D5/4476, C09D5/4492 take precedence) · CPC title

• C08K3/08

  Metals · CPC title

• C08K9/06

  with silicon-containing compounds · CPC title

• C09D5/24

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title

• C09D5/4453

  characterised by the nature of the curing agent · CPC title