Granted Patent B2

US 8,663,765 · App. 13/833,233 · Granted Mar 4, 2014

Abstract

Claims (30)

1. A coating composition comprising a water-based varnish that includes a water-dispersible polyester polymer having salt groups and a backbone or pendant unsaturated at least bicyclic group with a double bond located between carbon atoms of a ring.

2. The coating composition of claim 1 , wherein the unsaturated at least bicyclic group comprises a structure represented by the nomenclature expression:

bicyclo[x,y,z]alkene;

wherein:

x is 2 or more,

y and z are each at least 1, and

the term “alkene” denotes that the bicyclic group includes one or more carbon-carbon double bonds.

3. The coating composition of claim 2 , wherein the unsaturated at least bicyclic group comprises bicyclo[2.1.1]hexene, bicyclo[2.2.1]heptene, bicyclo[2.2.1]heptadiene, bicyclo[2.2.2]octene, bicyclo[2.2.2]octadiene, or a combination thereof.

4. The coating composition of claim 1 , wherein the unsaturated at least bicyclic group was incorporated into the polymer using nadic acid, methyl-nadic acid, or an anhydride ahydride or derivative thereof.

5. The coating composition of claim 1 , wherein the polyester polymer includes a plurality of the unsaturated at least bicyclic groups that constitute at least about 5 weight percent of the polyester polymer.

6. The coating composition of claim 1 , wherein the polyester polymer has an iodine value of at least about 10.

7. The coating composition of claim 1 , wherein the polyester polymer has a Tg of at least 25° C.

8. The coating composition of claim 1 , wherein the polyester polymer has an acid number of at least 15.

9. The coating composition of claim 1 , wherein the salt groups comprise neutralized acid or anhydride groups.

10. The coating composition of claim 1 , wherein the polyester polymer includes at least 5 weight percent of aromatic groups.

11. The coating composition of claim 1 , wherein the polyester polymer comprises a reaction product of ingredients including one or more of maleic acid or anhydride, and wherein a structural unit derived from maleic acid or anhydride includes the unsaturated at least bicyclic group.

12. The coating composition of claim 11 , wherein the structural unit is a Diels-Alder reaction product.

13. The coating composition of claim 1 , wherein the polyester polymer is formed from reactants including a dianhydride.

14. The coating composition of claim 13 , wherein the dianhydride comprises pyromellitic dianhydride.

15. The coating composition of claim 1 , wherein the coating composition includes a crosslinker.

16. The coating composition of claim 15 , wherein the crosslinker comprises a resole phenolic crosslinker.

17. A coating composition, wherein the coating composition includes:

50 to 95 weight percent, based on nonvolatile weight, of a water-dispersible aromatic polyester polymer having a backbone or pendant unsaturated at least bicyclic group with a double bond located between carbon atoms of a ring; and

5 to 50 weight percent, based on nonvolatile weight, of a resole phenolic crosslinker; and

a liquid carrier that comprises at least 50 weight percent of water.

18. The coating composition of claim 17 , wherein the unsaturated at least bicyclic group was incorporated into the polymer using nadic acid, methyl-nadic acid, or an anhydride or derivative thereof.

19. The coating composition of claim 18 , wherein the polyester polymer is formed from reactants including a dianhydride.

20. A method, comprising:

providing a water-based varnish that includes a water-dispersible polyester polymer having salt groups and a backbone or pendant unsaturated at least bicyclic group with a double bond located between carbon atoms of a ring; and

applying the coating composition to at least a portion of a metal substrate of a food or beverage can or a portion thereof.

Assignments (8)