Coating compositions for packaging articles and methods of coating

Abstract

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.