Electrodepositable coating composition having improved crater control

Patent metadata

Field	Value
Publication number	US-10329437-B2
Application number	US-201715637157-A
Country	US
Kind code	B2
Filing date	Jun 29, 2017
Priority date	Jun 30, 2016
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

The present invention is directed towards an electrodepositable coating composition comprising a polybutylene oxide polymer, an ionic film-forming polymer having functional groups, and a curing agent that is reactive with functional groups on the film-forming polymer. Also disclosed are methods of making the electrodepositable coating composition. Also disclosed are substrates treated with the electrodepositable coating composition.

First claim

We claim:

1. An electrodepositable coating composition comprising:
a polybutylene oxide polymer comprising a copolymer of butylene oxide and propylene oxide;
an ionic film-forming polymer having functional groups; and
a curing agent that is reactive with functional groups on the film-forming polymer.

2. The electrodepositable coating composition of claim 1 , wherein the molar ratio of butylene oxide to propylene oxide of the copolymer is at least 1:1.

3. The electrodepositable coating composition of claim 1 , wherein the polybutylene oxide polymer comprises at least two hydroxyl functional groups.

4. The electrodepositable coating composition of claim 1 , wherein the polybutylene oxide polymer has a hydroxyl equivalent weight of at least 500 g/mol.

5. The electrodepositable coating composition of claim 1 , wherein the polybutylene oxide polymer is present in the electrodepositable coating composition in an amount of 0.1% by weight to 10% by weight based on the total weight of the resin blend solids.

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

7. The electrodepositable coating composition of claim 1 , wherein the curing agent comprises a blocked polyisocyanate.

8. The electrodepositable coating composition of claim 7 , wherein the blocked polyisocyanate is at least partially blocked with the polybutylene oxide polymer as a blocking agent.

9. The electrodepositable coating composition of any of claim 1 further comprising a polyetheramine-adduct.

10. The electrodepositable coating composition of claim 9 , wherein the polyetheramine adduct is present in an amount of 3% to 20% by weight based on total weight of the resin blend solids.

11. The electrodepositable coating composition of claim 1 further comprising a polyamine-dialdehyde adduct comprising a polymerization product of a polyamine and a dialdehyde.

12. The electrodepositable coating composition of claim 11 , wherein the polyamine comprises a cationic amine-functionalized resin, a polyetheramine, or combinations thereof.

13. The electrodepositable coating composition of claim 11 , wherein the dialdehyde comprises glyoxal, glutaraldehyde, or combinations thereof.

14. The electrodepositable coating composition of claim 11 , wherein a ratio of aldehyde functional groups of the dialdehyde to amino-functional groups of the polyamine is 2:10 to 1:1.

15. The electrodepositable coating composition of claim 11 , wherein a ratio of the aldehyde functional groups of the dialdehyde to the amino-functional groups of the polyamine is 2:1 to 20:1.

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

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 a crater depth of the coating on the substrate as measured by a Mitutoyo Surftest SJ-402 stylus profilometer is reduced by at least 10% compared to a comparative coating composition that does not include the polybutylene oxide polymer.

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

20. The electrodepositable coating composition of claim 1 , wherein a crater depth of a coating on a substrate coated with the electrodepositable coating composition in an at least partially cured state is reduced by at least 10% compared to a comparative coating composition that does not include the polybutylene oxide polymer, as measured by a Mitutoyo Surftest SJ-402 stylus profilometer.

21. The electrodepositable coating composition of claim 1 , wherein a coating on a substrate coated with the electrodepositable coating composition in an at least partially cured state has an adhesion rating of at least 2, as measured by the White Alkyd Adhesion Test.

22. The method of claim 16 , wherein a crater depth of the coating on the substrate as measured by a Mitutoyo Surftest SJ-402 stylus profilometer is reduced by at least 10% compared to a comparative coating composition that does not include the polybutylene oxide polymer.

23. The method of claim 16 , wherein the coating on the substrate has an adhesion rating of at least 2, as measured by the White Alkyd Adhesion Test.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Kaylo Alan J
• Eswarakrishnan Venkatachalam
• Bice Jo-Ann E
• Wilson Craig A
• Szymanski Chester J
• Lewand Alycia
• Swanger Joseph R

Classifications

• C09D171/02

  Polyalkylene oxides · CPC title

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/643

  Reaction products of epoxy resins with at least equivalent amounts of amines · CPC title

• C09D5/44

  for electrophoretic applications (processes for coating by electrophoresis C25D13/00) · CPC title

• C09D163/00

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