Coating compositions for containers and methods of coating

• US 7,910,170 B2
• Filed: 10/18/2006
• Issued: 03/22/2011
• Est. Priority Date: 10/18/2005
• Status: Active Grant

• Current Assignee: Swimc, LLC (The Sherwin-Williams Company)
• Original Assignee: Valspar Sourcing, Inc. (Sherwin-Williams Company)
• Inventors: O'Brien, Robert M., Evans, Richard H., Spynda, Rachael A.
• Primary Examiner(s): Seidleck; James
• Assistant Examiner(s): Tischler; Frances
• Application Number:
  US11/550,451
• Publication Number:
  US 20070087146A1
• Time in Patent Office: 1,616 Days
• Field of Search: 428/34.1, 428/34.6, 428/34.7, 428/34.8, 428/35.1, 428/35.7, 428/35.8, 428/36.8, 428/36.9, 428/36.91, 428/36.92, 427/388.1, 427/388.4, 427/383.1, 427/384, 427/385.5, 427/386, 427/388.5, 528/272, 528/308.3, 528/300
• US Class Current: 427/388.1
• CPC Class Codes: C08G 59/182 using pre-adducts of epoxy compounds with curing agents
• CPC Class Codes: C08G 59/621 Phenols
• CPC Class Codes: C09D 163/00 Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
• CPC Class Codes: C09D 167/00 Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain based on polyester-amides C09D177/12; based on polyester-imides C09D179/08; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 5/02 Emulsion paints including aerosols
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/1317 Multilayer [continuous layer]
• CPC Class Codes: Y10T 428/1321 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1324 Flexible food casing [e.g., sausage type, etc.]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

This invention provides a coating composition for use on a food-contact surface of a container (e.g., a food or beverage can) that includes a polymer having one or more segments of Formula I:
—O—Ar—R_n—C(O)—O—R¹—O—C(O)—R_n—Ar—O—
wherein each Ar is independently a divalent aryl group (i.e., an arylene group) or heteroarylene group; R¹ is a divalent organic group; each R is independently a divalent organic group; and n is 0 or 1. Containers comprising the polymer and methods of making such containers are also provided.

Claims

1. A container comprising a food or beverage container, wherein at least a portion of an inside surface of the container is coated with a composition comprising a polymer having one or more segments of Formula I:

—

O—

Ar—

R_n—

C(O)—

O—

R¹—

O—

C(O)—

R_n—

Ar—

O—

wherein;

each Ar is independently a divalent aryl group or heteroarylene group;

each R is independently a divalent organic group;

R¹ is a divalent organic group; and

each n is 0 or 1.

2. The container of claim 1, wherein the polymer further comprises —

CH₂—

CH(OH)—

CH₂—

segments.

3. The container of claim 1, wherein R¹ provides hydrolytic stability to at least one of the adjacent ester linkages.

4. The container of claim 1, wherein R¹ is —

C(R²)₂—

Y_t—

C(R²)₂—

wherein each R² is independently hydrogen or an organic group, each Y is independently a divalent organic group, and t is 0 or 1.

5. The container of claim 4, wherein Y includes one or more ether or ester linkages.

6. The container of claim 4, wherein R¹ has the formula —

(C(R²)₂)_s—

wherein s is at least 2, wherein each R² is independently hydrogen or an organic group.

7. The container of claim 4, wherein Y is —

[Z_w—

C(R²)₂—

O—

C(O)—

R³—

C(O)—

O—

C(R²)₂—

]_vZ_w—

, wherein w is 0 or 1, v is 1 to 10, each R³ is independently a divalent organic group, and each Z is independently a divalent organic group.

8. The container of claim 7, wherein each Z provides hydrolytic stability to at least one adjacent ester linkages.

9. The container of claim 4, wherein each Y provides hydrolytic stability to at least one of the ester linkages adjacent R¹ in Formula I.

10. The container of claim 1, wherein n is 0.

11. The container of claim 1, wherein each Ar is independently a phenylene group.

12. The container of claim 11, wherein each Ar is independently a phenylene group of the formula —

C₆(R₄)₄—

, wherein each R⁴ is independently hydrogen, a halogen, or an organic group, wherein two R⁴ groups can optionally join to form a ring optionally containing one or more heteroatoms.

13. The container of claim 12, wherein each R⁴ is independently hydrogen or an organic group, wherein two R⁴ groups can optionally join to form a 6-membered ring.

14. The container of claim 12, wherein R⁴ is hydrogen.

15. The container of claim 1, wherein the composition is prepared from a water-based system.

16. The container of claim 1, wherein the composition is prepared from an organic solvent-based system.

17. The container of claim 1, which is a metal food or beverage can.

18. The container of claim 15, wherein the coating composition includes at least 25 weight percent of the polymer having segments of Formula I, based on the non-volatile film-forming components of the coating composition.

19. The container of claim 16, wherein the coating composition includes at least 50 weight percent of the polymer having segments of Formula I, based on the non-volatile film-forming components of the coating composition.

20. The container of claim 1, wherein the polymer, prior to any cure of the composition, includes ether linkages.

21. The container of claim 1, wherein the composition is substantially free of bound BPA, BADGE, BPF, and BFDGE.

22. The container of claim 1, wherein the polymer has a number average molecular weight of at least 2,000.

23. The container of claim 1, wherein the polymer has a number average molecular weight of at least 4,000.

24. The container of claim 1, wherein R₁ includes at least 5 carbon atoms.

25. The container of claim 1, wherein R₁ includes at least 8 carbon atoms.

26. The container of claim 1, wherein the polymer is made from a compound of Formula II:

HO—

Ar—

R_n—

C(O)—

O—

R¹—

O—

C(O)—

R_n—

Ar—

OH,

wherein each Ar, R, R¹, and n are as described in Formula I.

27. An article, comprising:

a metal food or beverage container including;

a coating composition applied to at least a portion of an inside surface of the container comprising a liquid carrier and a polymer having ether linkages and one or more backbone segments of Formula I;

—

O—

Ar—

R_n—

C(O)—

O—

R¹—

O—

C(O)—

R_n—

Ar—

O—

wherein;

each Ar is independently a divalent phenylene group of the formula —

C₆(R⁴)₄—

, wherein each R⁴ is independently hydrogen, a halogen, or an organic group, wherein two R⁴ groups can optionally join to form a ring optionally containing one or more heteroatoms;

each R is independently a divalent organic group;

R¹ is a divalent organic group; and

each n is 0 or 1.

28. The article of claim 27, wherein the polymer comprises a reaction product of a non-BPA or non-BPF based diepoxide reacted with a compound of Formula II:

HO—

Ar—

R_n—

C(O)—

O—

R¹—

O—

C(O)—

R_n—

Ar—

OH,

wherein each Ar, R, R¹, and n are as described for Formula I.

29. The article of claim 27, wherein the polymer further comprises —

CH₂—

CH(OH)—

CH₂—

segments.

30. The article of claim 27, wherein the coating composition is substantially free of bound BPA, BADGE, BPF, and BFDGE.

31. The article of claim 27, wherein the coating composition comprises a cured coating.

32. An article, comprising:

a metal food or beverage can including;

a coating composition applied to at least a portion of an inside surface of the can comprising at least 25 weight percent of a polymer, based on the non-volatile film forming components of the coating composition, having;

ether linkages;

—

CH₂—

CH(OH)—

CH₂—

segments; and

segments of Formula I;

—

O—

Ar—

R_n—

C(O)—

O—

R¹—

O—

C(O)—

R_n—

Ar—

O—

;

wherein;

each Ar is independently a divalent phenylene group of the formula —

C₆(R⁴)₄—

, wherein each R⁴ is independently hydrogen, a halogen, or an organic group, wherein two R⁴ groups can optionally join to form a ring optionally containing one or more heteroatoms,

each R is independently a divalent organic group,

R¹ is a divalent organic group, and

each n is 0 or 1.