Coating compositions and articles coated therewith
View Patent ↗The present invention relates to a binder useful in coating end uses. The binder preferably includes an aqueous polymer dispersion and a vinyl polymer. The binder is useful in packaging coatings, including coatings for use on food or beverage cans, or a portion thereof.
1. An article, comprising:
a food or beverage can, or a portion thereof, comprising:
a metal substrate; and
a coating disposed on at least a portion of the metal substrate, wherein the coating is formed from an aqueous coating composition that includes a latex polymer comprising a water-dispersible polymer and a vinyl polymer that are linked together by one or more covalent linkages.
2. The article of claim 1 , wherein the water-dispersible polymer comprises a water-dispersible acrylic polymer, a water-dispersible alkyd polymer, a water-dispersible polyester polymer, a water-dispersible polyurethane polymer, or a mixture or copolymer thereof.
3. The article of claim 1 , wherein the vinyl polymer is formed by emulsion polymerizing an ethylenically unsaturated component in the presence of an aqueous dispersion of the water-dispersible polymer.
4. The article of claim 1 , wherein the one or more covalent linkages is a step-growth linkage, a substituted or unsubstituted hydrocarbyl linkage, or a combination thereof.
5. The article of claim 1 , wherein the one or more covalent linkages comprises a carbonate ester, epoxy, ether, imide, imine, urethane, or urea linkage, or a combination thereof.
6. The article of claim 1 , wherein:
the water-dispersible polymer is present in an amount of at least 5 wt- %, based on the total weight of the vinyl polymer and the water-dispersible polymer; and
the vinyl polymer is present in an amount of at least 15 weight percent, based on the total weight of the vinyl polymer and the water-dispersible polymer.
7. The article of claim 1 , wherein at least 40 weight percent of the vinyl polymer comprises an alkyl acrylate, alkyl methacrylate, or a combination thereof, based on the total non-volatile weight of ingredients used to make the vinyl polymer.
8. The article of claim 1 , wherein the vinyl polymer has a number average molecular weight of at least 100,000.
9. The article of claim 1 , wherein the coating composition is substantially free of bound bisphenol A and aromatic glycidyl ether compounds.
10. The article of claim 1 , wherein the coating composition, when present on an aluminum beverage can end at a dry film thickness of 7 milligrams per square inch, passes less than 5 milliamps of current after being exposed for 4 seconds to a room -temperature electrolyte solution containing 1% by weight of NaCl dissolved in water.
11. The article of claim 1 , wherein the coating composition is present on a food-contact surface of the metal substrate.
12. The article of claim 1 , wherein the water-dispersible polymer comprises a polyurethane-urea polymer.
13. The article of claim 12 , wherein the polyurethane-urea polymer includes one or more aliphatic carbon-carbon double bonds.
14. The article of claim 13 , wherein the polyurethane-urea polymer includes one or more (poly)butadiene groups.
15. The article of claim 1 , wherein the one or more covalent linkages comprises a condensation linkage.
16. The article of claim 15 , wherein the one or more covalent linkages are hydrolytically stable.
17. A method, comprising:
providing a coating composition comprising an aqueous dispersion of a latex polymer, wherein the latex polymer includes a water-dispersible polymer and a vinyl polymer that are linked together by one or more covalent linkages; and
forming a food or beverage can or a portion thereof from a metal substrate having the coating composition disposed on at least one surface.
18. The method of claim 17 , wherein the coating composition comprises at least 10 weight percent of organic solvent and at least 20 weight percent of water.
19. The method of claim 17 , wherein the latex polymer comprises at least 5 weight percent of the coating composition, based on the weight of latex polymer solids relative to the total weight of the coating composition.
20. A food or beverage can, or a portion thereof, produced by the method of claim 17 .
21. A method, comprising:
providing a coating composition comprising an aqueous dispersion of a latex polymer, wherein the latex polymer includes a water-dispersible acrylic polymer and a vinyl polymer that are linked together by one or more hydrolytically stable covalent linkages, wherein the vinyl polymer is formed by emulsion polymerizing an ethylenically unsaturated component in the presence of an aqueous dispersion of the water-dispersible polymer; and
forming a food or beverage can or a portion thereof from a metal substrate having the coating composition disposed on an interior surface.
22. The method of claim 21 , wherein the coating composition contains less than 2 weight percent, if any, of vinyl chloride materials.
23. The method of claim 22 , wherein the coating composition is substantially free of Bisphenol A and aromatic glycidyl ether compounds.