Coating compositions for aluminum beverage cans and methods of coating same

Patent metadata

Field	Value
Publication number	US-9415900-B2
Application number	US-201514918258-A
Country	US
Kind code	B2
Filing date	Oct 20, 2015
Priority date	Oct 20, 2004
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A coating composition for a food or beverage can that includes an emulsion polymerized latex polymer formed by combining an ethylenically unsaturated monomer component with an aqueous dispersion of a water-dispersible polymer.

First claim

What is claimed is:

1. An inside spray beverage can coating composition, comprising:
an emulsion polymerized latex polymer that is prepared from ingredients including:
a salt of an acid- or anhydride-functional acrylic polymer and an amine;
an ethylenically unsaturated monomer component that includes a vinyl aromatic compound and an oxirane-group containing monomer; and
water;

wherein the coating composition is substantially free of bound bisphenol A, and wherein the coating composition is suitable for forming an inside spray coating of a two-piece drawn and ironed aluminum beverage can.

2. The coating composition of claim 1 , wherein the oxirane-group containing monomer is present in an amount of 0.1 wt-% to 30 wt-%, based on the weight of the ethylenically unsaturated monomer component.

3. The coating composition of claim 1 , wherein the oxirane-group containing monomer is present in an amount of more than 5 wt-% to 9 wt-%, based on the weight of the ethylenically unsaturated monomer component.

4. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component comprises a vinyl aromatic component that is at least 20 wt-% of the ethylenically unsaturated monomer component, and wherein the vinyl aromatic component comprises one or more aromatic compounds.

5. The coating composition of claim 1 , wherein the vinyl aromatic compound is styrene.

6. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component comprises at least 20 wt-% of styrene.

7. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component includes ethyl acrylate.

8. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component includes ethyl acrylate, styrene, and glycidyl methacrylate.

9. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component includes butyl acrylate, styrene, and glycidyl methacrylate.

10. The coating composition of claim 1 , wherein the coating composition is made without using PVC compounds.

11. The coating composition of claim 1 , wherein the emulsion polymerized latex polymer is substantially free of bound aromatic glycidyl ether compounds.

12. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component does not include acrylamide, methacrylamide, N-isobutoxymethyl acrylamide, or N-butoxymethyl acrylamide.

13. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer component does not include any vinyl acrylamide monomers.

14. The coating composition of claim 1 , wherein at least 25 wt-% of the ethylenically unsaturated monomer component is used in making the latex polymer, based on the total weight of ethylenically unsaturated monomer component and salt of the acid- or anhydride-functional acrylic polymer.

15. The coating composition of claim 1 , wherein the acid- or anhydride-functional acrylic polymer has a number average molecular weight of 1,500 to 50,000.

16. The coating composition of claim 1 , wherein the acid- or anhydride-functional acrylic polymer has a number average molecular weight of 2,000 to 20,000.

17. The coating composition of claim 1 , wherein the acid- or anhydride-functional acrylic polymer has an acid number of at least 40.

18. The coating composition of claim 1 , wherein at least 40 wt-% of the ethylenically unsaturated monomer component comprises one or more monomers selected from alkyl acrylates and methacrylates.

19. The coating composition of claim 1 , wherein the coating composition, when spray applied onto an interior of a 12 ounce two-piece drawn and ironed aluminum beverage can at 120 to 130 milligrams per can coating weight and cured at 188° C. to 199° C. (measured at the can dome) for 30 seconds, exhibits a global extraction result of less than 10 ppm.

20. The coating composition of claim 1 , wherein the coating composition, when spray applied onto an interior of a 12 ounce two-piece drawn and ironed aluminum beverage can at 120 to 130 milligrams per can coating weight and cured at 188° C. to 199° C. (measured at the can dome) for 30 seconds, shows no craze after the outside of the dome apex of the can is subjected to a 12 in-lbs reverse impact.

21. The coating composition of claim 1 , wherein the coating composition, when spray applied onto an interior of a 12 ounce two-piece drawn and ironed aluminum beverage can at 120 to 130 milligrams per can coating weight and cured at 188° C. to 199° C. (measured at the can dome) for 30 seconds, exhibits no adhesion failure when tested pursuant to ASTM D-3359-Test method B after retort in deionized water for 90 minutes at a heat of 121° C. and a corresponding pressure.

22. The coating composition of claim 1 , wherein at least 10 wt-% of the salt of the acid- or anhydride-functional acrylic polymer is used in making the latex polymer, based on the total weight of ethylenically unsaturated monomer component and salt of the acid- or anhydride-functional acrylic polymer.

23. The coating composition of claim 1 , wherein the coating composition is made without using PVC compounds.

24. The coating composition of claim 1 , wherein the acid- or anhydride-functional acrylic polymer comprises an organic-solution polymerized acid- or anhydride-functional acrylic polymer.

25. The coating composition of claim 24 , wherein the polymerizable unsaturated monomers used to generate the organic-solution polymerized acid- or anhydride-functional acrylic polymer include methacrylic acid, styrene, and ethyl acrylate.

26. The coating composition of claim 24 , wherein the oxirane-group containing monomer is present in an amount of more than 5 wt-% to 30 wt-%, based on the weight of the ethylenically unsaturated monomer component.

27. The coating composition of claim 24 , wherein the oxirane group-containing monomer comprises glycidyl methacrylate.

28. The coating composition of claim 24 , wherein the coating composition is substantially free of bound aromatic glycidyl ether compounds.

29. The coating composition of claim 24 , wherein at least 50 wt-% of the ethylenically unsaturated monomer component is used in making the latex polymer, based on the total weight of ethylenically unsaturated monomer component and salt of the organic-solution polymerized acid- or anhydride-functional acrylic polymer.

30. The coating composition of claim 24 , wherein the organic-solution polymerized acid- or anhydride-functional acrylic polymer has an acid number of at least 40.

31. The coating composition of claim 24 , wherein the organic-solution polymerized acid- or anhydride-functional acrylic polymer has an acid number of at least 100.

32. The coating composition of claim 24 , wherein the acid- or anhydride-functional acrylic polymer comprises more than 30 wt-% acid- or anhydride-functional monomers, based on the weight of polymerizable unsaturated monomer used to generate the organic-solution polymerized acid- or anhydride-functional acrylic polymer.

33. The coating composition of claim 24 , wherein the acid- or anhydride-functional monomers included in the polymerizable unsaturated monomers used to generate the organic-solution polymerized acid-or anhydride-functional acrylic polymer consists of methacrylic acid.

Assignees

• Valspar Sourcing Inc

Inventors

• O'Brien Robert M
• Rardon Daniel E
• Spynda Rachael Ann
• Bartley George K
• Evans Richard H

Classifications

• B32B27/00

  Layered products comprising {a layer of} synthetic resin {(fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18)} · CPC title

• B05D7/227

  of containers, cans or the like · CPC title

• Y10T428/31855

  Of addition polymer from unsaturated monomers · CPC title

• C23C4/12

  characterised by the method of spraying · CPC title

• B05D2202/00

  Metallic substrate · CPC title