Coating compositions for packaging articles and methods of coating

• US 11,130,881 B2
• Filed: 10/15/2012
• Issued: 09/28/2021
• Est. Priority Date: 04/16/2010
• Status: Active Grant

• Current Assignee: Swimc, LLC (The Sherwin-Williams Company)
• Original Assignee: Swimc, LLC (The Sherwin-Williams Company)
• Inventors: Evans, Richard H., Niederst, Jeffrey, O'Brien, Robert M., Prouvost, Benoit, Romagnoli, Kevin, Schutte, Grant, Stenson, Paul, Van Kuren, Tom
• Primary Examiner(s): Patterson, Marc A
• Application Number:
  US13/651,796
• Publication Number:
  US 20130280455A1
• Time in Patent Office: 3,270 Days
• Field of Search: 428 357, 428 369
• CPC Class Codes: B05D 7/14 to metal, e.g. car bodies involving a chemical reaction between the metal and the coating C23
• CPC Class Codes: B05D 7/227 of containers, cans or the like
• CPC Class Codes: B21D 31/00 Other methods for working sheet metal, metal tubes, metal profiles deforming one surface of tubes helically by rolling B21H3/00; upsetting B21J5/08; working metal by removing material therefrom B23; embossing B44B
• CPC Class Codes: B65D 25/00 Details of other kinds or types of rigid or semi-rigid containers
• CPC Class Codes: C08G 59/066 with chain extension or advancing agents
• CPC Class Codes: C08G 59/24 carbocyclic
• CPC Class Codes: C09D 171/08 Polyethers derived from hydroxy compounds or from their metallic derivatives C09D171/02 takes precedence
• CPC Class Codes: C09D 5/08 Anti-corrosive paints
• CPC Class Codes: Y10T 428/1355 Elemental metal containing [e.g., substrate, foil, film, coating, etc.]

Abstract

This invention provides a polymer that is useful in a variety of applications, including as a binder polymer of a coating composition, and especially a packaging coating composition. Packaging articles (e.g., containers) comprising the polymer and methods of making such packaging articles are also provided.

Claims

1. An article comprising:

a metal substrate of a food or beverage can or a portion thereof; and

a coating applied on at least a portion of a surface of the metal substrate, wherein the coating is an interior food-contact coating formed from a coating composition comprising;

a film-forming amount of a polyether polymer having;

a plurality of pendant secondary hydroxyl groups attached to backbone carbon atoms;

one or more segment of the following Formula I;

—

O—

Ar—

(R_n—

Ar)_n—

O—

,

wherein;

each Ar is independently an aryl or heteroaryl group,

each n is 1,

R includes at least one cyclic group, and

the two oxygen atoms are each ether oxygen;

wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, and the polyether polymer has a Tg of from 70 to 150°

C.

2. The article of claim 1, wherein the polyether polymer has a Tg of from 80 to 110°

C.

3. The article of claim 1, wherein aryl or heteroaryl groups constitute at least 20 weight percent of the polyether polymer, based on the total weight of aryl and heteroaryl groups present in the polymer relative to the weight of the polymer.

8. The article of claim 1, wherein R includes a quaternary carbon atom in a backbone segment connecting the two Ar groups.

9. The article of claim 1, wherein the at least one cyclic group is an aryl or heteroaryl group.

10. The article of claim 1, wherein:

(i) R is free of ester linkages and (ii) the at least one cyclic group is a divalent alicyclic group.

4. An article comprising:

a metal substrate of a food or beverage can or a portion thereof; and

a coating applied on at least a portion of a surface of the metal substrate, wherein the coating is an interior food-contact coating formed from a coating composition comprising;

a film-forming amount of a polyether polymer having;

a plurality of pendant secondary hydroxyl groups attached to backbone carbon atoms;

one or more segment of the following Formula I;

—

O—

Ar—

(R_n—

Ar)_n—

O—

,

wherein;

each Ar is independently an aryl or heteroaryl group,

each n is 1,

R includes at least one cyclic group, and

the two oxygen atoms are each ether oxygen; and

a glass transition temperature (Tg) of at least 70°

C.; and

wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, the polyether polymer is a reaction product of ingredients including a polyepoxide and a polyhydric phenol, and the coating has an overall average dry coating thickness of about 2 to about 12 microns.

5. The article of claim 4, wherein each of the polyepoxide and the polyhydric phenol independently include an aryl or heteroaryl group, and wherein the polyepoxide includes the segment of Formula I.

6. The article of claim 4, wherein one or more of the polyepoxide or polyhydric phenol are selected from 1,1-di(4-hydroxyphenyl)-cyclohexane, 1,1-di(4-hydroxy-3-methylphenyl)-cyclohexane, 1,1-di(4-hydroxy-3,5-dimethylphenyl)-cyclohexane, or the diglycidyl ether of any of these.

7. The article of claim 4, wherein one or more of the polyepoxide or polyhydric phenol are selected from:

1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane or the diglycidyl ether of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane.

11. An article comprising:

a metal substrate of a food or beverage can or a portion thereof; and

a coating applied on at least a portion of a surface of the metal substrate, wherein the coating is an interior food-contact coating formed from a coating composition comprising;

a film-forming amount of a polyether polymer having;

a plurality of pendant secondary hydroxyl groups attached to backbone carbon atoms;

one or more segment of the following Formula I;

—

O—

Ar—

(R_n—

Ar)_n—

O—

,

wherein;

each Ar is independently an aryl or heteroaryl group,

each n is 1,

R includes at least one cyclic group, and

the two oxygen atoms are each ether oxygen; and

a glass transition temperature (Tg) of at least 70°

C.; and

wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, R has a molecular weight of greater than 75 and less than 500, and segments of Formula I constitute at least 30 weight percent of the polymer.

12. A thermoset coating composition, comprising:

a film-forming amount of a polyether polymer, wherein the polyether polymer is a reaction product of ingredients including a dihydric phenol and a diepoxide, the polyether polymer having;

one or more segments of the following Formula I;

—

O—

Ar—

(R_n—

Ar)_n—

O—

, wherein;

each Ar is independently a phenylene group,

each n is 1,

R includes at least one cyclic group, and

the two oxygen atoms are each ether oxygen;

a plurality of secondary hydroxyl groups attached to backbone carbon atoms, in —

CH₂—

CH(OH)—

CH₂—

segments;

and a number average molecular weight of at least 2,000; and

a liquid carrier;

wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, and the polyether polymer has a Tg of from 70 to 150°

C.

13. The coating composition of claim 12, wherein the polyether polymer has a Tg of from 80 to 110°

C.

14. The coating composition of claim 12, wherein the polyether polymer does not include a segment of Formula I in which n is 1 and R comprises a segment of the below formula:

—

R⁵_t—

C(O)—

O—

R⁴—

O—

C(O)—

R⁵_t—

wherein;

R⁴ is a divalent organic group;

each R⁵ is a divalent organic group; and

each t is 0 or 1.

15. An article comprising:

a metal substrate of a food or beverage can or a portion thereof; and

a food-contact coating applied on at least a portion of an interior surface of the metal substrate, wherein the coating is formed from a thermoset coating composition comprising;

a polyether polymer that has a glass transition temperature (Tg) of at least 70°

C. and has a backbone that includes;

(i) segments of the following Formula I;

—

O—

Ar—

(R_n—

Ar)_n—

O—

, wherein;

each Ar is independently a phenylene group,

each n is 1,

R includes at least one cyclic group, and

the two oxygen atoms are each ether oxygen; and

(ii) a plurality of secondary hydroxyl groups attached to backbone carbon atoms, in —

CH₂—

CH(OH)—

CH₂—

segments; and

a liquid carrier;

wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, the polyether polymer is a reaction product of ingredients including a diepoxide and a dihydric phenol, and the coating is a mono-layer or multi-layer coating having an overall average dry coating thickness of from about 3 to about 12 microns.

16. The article of claim 15, wherein the polyether polymer has a number average molecular weight of at least 2,000 and constitutes at least 30 weight percent of the coating composition, based on the total weight of resin solids in the coating composition.

17. The article of claim 15, wherein the polyether polymer does not include a segment of Formula I in which n is 1 and R comprises a segment of the below formula:

—

R⁵_t—

C(O)—

O—

R⁴—

O—

C(O)—

R⁵_t—

wherein;

R⁴ is a divalent organic group;

each R⁵ is a divalent organic group; and

each t is 0 or 1.

18. The article of claim 15, wherein the polyether polymer includes at least 30 weight percent of the segments of Formula I.

19. The article of claim 16, wherein the polyether polymer includes at least 50 weight percent of the segments of Formula I.

20. The article of claim 15, wherein the polyether polymer has a Tg of from 70 to 150°

C.