Electrodepositable coating composition having improved crater control

• US 10,421,874 B2
• Filed: 06/29/2017
• Issued: 09/24/2019
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Eswarakrishnan, Venkatachalam, Kaylo, Alan J., Bice, Jo-Ann E., Wilson, Craig A., Szymanski, Chester J., Lewand, Alycia, Swanger, Joseph R.
• Primary Examiner(s): Truong, Duc
• Application Number:
  US15/637,064
• Publication Number:
  US 20180002545A1
• Time in Patent Office: 817 Days
• Field of Search: 528245, 528230
• CPC Class Codes: C09D 179/02 Polyamines
• CPC Class Codes: C09D 5/4419 with polymers obtained otherwise than by polymerisation reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09D 5/4496 characterised by the nature of the curing agents

Abstract

The present invention is directed towards an electrodepositable coating composition comprising a polyamine-dialdehyde adduct comprising a polymerization product of a polyamine and a dialdehyde. Also disclosed are methods of making the electrodepositable coating composition, methods of coating a substrate, and substrates treated with the electrodepositable coating composition.

Claims

1. An electrodepositable coating composition comprising a polyamine-dialdehyde adduct comprising a polymerization product of a polyamine and a dialdehyde.

2. The electrodepositable coating composition of claim 1, wherein a ratio of aldehyde functional groups of the dialdehyde to amino-functional groups of the polyamine is 2:

10 to 1;

1.

3. The electrodepositable coating composition of claim 1, wherein the polyamine comprises a cationic amine-functionalized resin, a first polyetheramine, or combinations thereof.

4. The electrodepositable coating composition of claim 1, wherein the dialdehyde comprises glyoxal, glutaraldehyde, or combinations thereof.

5. The electrodepositable coating composition of claim 1, wherein the z-average molecular weight of the polyamine-dialdehyde adduct is greater than 100,000 g/mol.

6. The electrodepositable coating composition of claim 1, further comprising:

(a) an ionic film-forming polymer having functional groups; and

(b) a curing agent that is reactive with functional groups on the film-forming polymer.

7. The electrodepositable coating composition of claim 6, wherein the polyamine-dialdehyde adduct is present in an amount of 0.2% by weight to 20% by weight based on the total weight of the resin blend solids.

8. The electrodepositable coating composition of claim 1, wherein the polyamine-dialdehyde adduct comprises an ionic film-forming polymer having functional groups, and further comprising a curing agent that is reactive with functional groups on the film-forming polymer.

9. The electrodepositable coating composition of claim 8, wherein a ratio of aldehyde functional groups of the dialdehyde to amino-functional groups of the polyamine is 2:

1 to 20;

1.

10. The electrodepositable coating composition of claim 8, wherein the polyamine-dialdehyde adduct is present in an amount of 50% by weight to 90% by weight based on the total weight of the resin blend solids.

11. The electrodepositable coating composition of claim 1, further comprising a polyetheramine-adduct.

12. The electrodepositable coating composition of claim 11, wherein the polyetheramine-adduct is present in an amount of 3% to 20% by weight based on total weight of resin blend solids.

13. The electrodepositable coating composition of claim 1, further comprising a polybutylene oxide polymer.

14. The electrodepositable coating composition of claim 13, wherein the polybutylene oxide polymer comprises a copolymer of butylene oxide and propylene oxide.

15. The electrodepositable coating composition of claim 14, wherein the polybutylene oxide polymer is present in an amount of 0.1% to 10% by weight based on the total weight of the resin blend solids.

16. The electrodepositable coating composition of claim 1, wherein the electrodepositable coating composition is substantially free of tin.

17. A substrate coated with the electrodepositable coating composition of claim 1 in an at least partially cured state.

18. The substrate of claim 17, wherein crater depth of the coating on the substrate as measured by a Mitutoyo Surftest SJ-402 skidless stylus profilometer is reduced by at least 10% compared to a comparative coating composition that does not include the polyamine-dialdehyde adduct.

19. The substrate of claim 17, wherein the coating has an adhesion rating of at least 2, as measured by the White Alkyd Adhesion Test.

20. A process for preparing the electrodepositable coating composition of claim 1, wherein the electrodepositable coating composition further comprises an ionic film-forming polymer and a curing agent, the process comprising the step of mixing:

(a) the ionic film-forming polymer, wherein the ionic film-forming polymer comprises the polyamine-dialdehyde adduct; and

(b) the curing agent.

21. A process for preparing the electrodepositable coating composition of claim 1, wherein the electrodepositable coating composition further comprises an ionic film-forming polymer and a curing agent, the process comprising the step of mixing:

(a) the ionic film-forming polymer;

(b) the curing agent; and

(c) the polyamine-dialdehyde adduct.

22. A method of coating a substrate comprising electrophoretically applying the electrodepositable coating composition of claim 1 to at least a portion of the substrate.