COATING COMPOSITIONS FOR PACKAGING ARTICLES AND METHODS OF COATING
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.
1 - 25 . (canceled).
26 . A food or beverage can coating composition that includes:
a polyether polymer having a backbone formed from a diglycidyl ester or diglycidyl ether of cyclobutanediol, the polyether polymer having a number average molecular weight of at least 2,000 and a glass transition temperature (Tg) of at least 70° C.; and
a carrier liquid;
wherein the coating composition is at least substantially free of bisphenol A and the diglycidyl ether of bisphenol A, and is suitable for use in forming a food-contact coating.
27 . The coating composition of claim 26 , wherein the backbone is formed from a diglycidyl ether of cyclobutanediol.
28 . The coating composition of claim 26 , wherein the backbone is formed from a diglycidyl ether of tetramethylcyclobutanediol.
29 . The coating composition of claim 26 , wherein the backbone is formed from 1,3-dihydroxy-2,2,4,4,tetramethylcyclobutane) diglycidyl ether.
30 . The coating composition of claim 26 , wherein the polyether polymer includes one or more pendant hydroxyl groups attached to backbone carbon atoms.
31 . The coating composition of claim 26 , wherein the backbone includes -CH 2 -CH(OH)-CH 2 - segments.
32 . The coating composition of claim 26 , wherein the polyether polymer has a number average molecular weight of at least 3,000.
33 . The coating composition of claim 26 , wherein the polyether polymer has a number average molecular weight of at least 4,000.
34 . The coating composition of claim 26 , wherein the polyether polymer has a Tg of at least 70° C.
35 . The coating composition of claim 26 , wherein the polyether polymer has a Tg from about 80° C. to about 110° C.
36 . The coating composition of claim 26 , wherein the polyether polymer comprises a polyether-acrylic copolymer that includes both the polyether polymer and an acrylic component.
37 . The coating composition of claim 36 , wherein the coating composition is a water-based system.
38 . The coating composition of claim 26 , wherein the coating composition is a water-based system, and wherein the polyether polymer constitutes at least 10 wt-% of the total resin solids in the coating composition.
39 . The coating composition of claim 26 , wherein the coating composition is a solvent-based system, and wherein the polyether polymer constitutes at least 30 wt-% of the total resin solids in the coating composition.
40 . The coating composition of claim 26 , wherein the coating composition includes a crosslinker.
41 . The coating composition of claim 40 , wherein the crosslinker comprises a phenoplast.
42 . A metal food or beverage can or a portion thereof having a food- contact coating formed from the coating composition of claim 26 .
43 . The metal food or beverage can or a portion thereof according to claim 42 , wherein the backbone is formed from a diglycidyl ether of cyclobutanediol.
44 . The metal food or beverage can or a portion thereof according to claim 42 , wherein the backbone is formed from a diglycidyl ether of tetramethylcyclobutanediol.
45 . A method, including:
applying the coating composition of claim 26 on at least a portion of a surface of a metal substrate prior to, or after, forming the substrate into a food or beverage container or a portion thereof.
46 . The method of claim 45 , wherein the backbone is formed from a diglycidyl ether of cyclobutanediol.
47 . The method of claim 45 , wherein the backbone is formed from a diglycidyl ether of tetramethylcyclobutanediol.