Methods and materials for the functionalization of polymers and coatings including functionalized polymer
View Patent ↗The disclosure provides a functionalized polymer for use in coating compositions and a method for making the functionalized polymer. In some embodiments, the functionalized polymer is a water-dispersible polymer, more preferably a water-dispersible polyester polymer, having one or more side groups including one or more salt groups. Packaging containers (e.g., food or beverage cans) comprising the functionalized polymer and methods of making such containers are also provided.
1. An article comprising a food or beverage can, or a portion thereof, the article comprising:
a metal substrate; and
a coating disposed on at least a portion of the metal substrate, the coating formed from a coating composition comprising an aqueous dispersion of a water-dispersible polymer, wherein the polymer includes:
a backbone having at least one heteroatom; and
a side group that includes at least one salt group, wherein the side group comprises the reaction product of an unsaturated compound having at least one salt or salt-forming group that is attached to another portion of the polymer via reaction of the unsaturated compound with one or more double or triple bonds, with the proviso that the reaction of the unsaturated compound with the one or more double or triple bonds does not require the participation of a free-radical initiator.
2. The article of claim 1 , wherein the side group is attached directly to the backbone.
3. The article of claim 1 , wherein the side group is attached to another portion of the polymer via a carbon-carbon bond.
4. The article of claim 1 , wherein the side group includes at least a portion of a cyclic group that links the side group to the backbone or another portion of the water-dispersible polymer that is attached to the backbone.
5. The article of claim 4 , wherein the cyclic group has at least one carbon-carbon double bond present in a ring of the cyclic group.
6. The article of claim 1 , wherein the reaction of the unsaturated compound with the one or more double or triple bonds comprises a pericyclic reaction.
7. The article of claim 6 , wherein the reaction of the unsaturated compound with the one or more double or triple bonds comprises a cycloaddition reaction.
8. The article of claim 7 , wherein the cycloaddition reaction is a Diels-Alder reaction.
9. The article of claim 1 , wherein the reaction of the unsaturated compound with the one or more double or triple bonds comprises an Ene reaction.
10. The article of claim 1 , wherein the at least one salt group of the side group comprise a neutralized acid or anhydride group.
11. The article of claim 1 , wherein the unsaturated compound includes at least two conjugated carbon-carbon double bonds.
12. The article of claim 1 , wherein the unsaturated compound comprises sorbic acid or neutralized sorbic acid.
13. The article of claim 1 , wherein the side group is formed from a single molecule of the unsaturated compound having a molecular weight of less than 200.
14. The article of claim 1 , wherein the side group is attached, via a carbon-carbon bond, to a structural unit derived from maleic anhydride.
15. The article of claim 1 , wherein the water-dispersible polymer is a polyester polymer.
16. The article of claim 15 , wherein the polyester polymer has a glass transition temperature of at least 25° C. and a number average molecular weight of at least 2,000.
17. The article of claim 1 , wherein the article comprises a riveted food or beverage can end.
18. The article of claim 1 , wherein the coating is located on an interior side of the article.
19. An article comprising a food or beverage can, or a portion thereof, the article comprising:
a metal substrate; and
a coating disposed on at least a portion of the metal substrate, the coating formed from a coating composition comprising an aqueous dispersion of a water-dispersible polyester polymer, wherein the polymer includes a side group that includes at least one salt group, wherein the side group comprises a Diels-Alder or an Ene reaction product of an unsaturated compound having at least one salt or salt-forming group that is attached to another portion of the polymer via reaction of the unsaturated compound with one or more double or triple bonds.
20. The article of claim 19 , wherein the unsaturated compound comprises sorbic acid or neutralized sorbic acid.