Stabilizer and coating compositions thereof

Abstract

Food and beverage containers and other packaging articles having a coating composition on a substrate, wherein the coating composition comprises: a thermoplastic dispersion; and an epoxy-functional stabilizer derived from: a polyhydric phenol having one or more aryl or heteroaryl groups in which each aryl or heteroaryl group includes a hydroxyl group attached to the ring and a substituent group attached to the ring at an ortho or meta position relative to the hydroxyl group; or (ii) a polyhydric phenol having two or more aryl or heteroaryl groups joined by a polar linking group or by a linking group having a molecular weight of at least 125 Daltons; or (iii) a polyhydric phenol having the features of both (i) and (ii).

1 . A packaging article comprising a coating composition on a substrate, wherein the coating composition comprises:
 a thermoplastic dispersion; and   an epoxy-functional stabilizer derived from:
 (i) a polyhydric phenol having one or more aryl or heteroaryl groups in which each aryl or heteroaryl group includes a hydroxyl group attached to the ring and a substituent group attached to the ring at an ortho or meta position relative to the hydroxyl group; or 
 (ii) a polyhydric phenol having two or more aryl or heteroaryl groups joined by a polar linking group or by a linking group having a molecular weight of at least 125 Daltons; or 
 (iii) a polyhydric phenol having the features of both (i) and (ii). 
   
     
     
         2 . A packaging article according to  claim 1 , wherein the article comprises a food container or portion thereof. 
     
     
         3 . A packaging article according to  claim 1 , wherein the article comprises a beverage container or portion thereof. 
     
     
         4 . A packaging article according to  claim 1 , wherein the article comprises a metal can, container or portion thereof. 
     
     
         5 . A packaging article according to  claim 4 , wherein the article comprises a closure, internal crown, two or three-piece can, shallow drawn can, deep drawn can, can end, monobloc aerosol container or general industrial container. 
     
     
         6 . A packaging article according to  claim 1 , wherein the coating composition is on a food-contact surface of the substrate. 
     
     
         7 . A packaging article according to  claim 1 , wherein the coating composition is cured. 
     
     
         8 . A packaging article according to  claim 7 , wherein the coating composition is adhered to at least an interior surface of the article. 
     
     
         9 . A packaging article according to  claim 1 , wherein the coating composition contains a vinyl chloride copolymer. 
     
     
         10 . A packaging article according to  claim 1 , wherein the coating composition contains a vinyl chloride homopolymer. 
     
     
         11 . A packaging article according to  claim 1 , wherein the thermoplastic dispersion comprises a vinyl chloride copolymer or homopolymer having a number average molecular weight of from about 40,000 to about 300,000. 
     
     
         12 . A packaging article according to  claim 11  wherein the thermoplastic dispersion comprises particles of the copolymer or homopolymer dispersed in a liquid carrier. 
     
     
         13 . A packaging article according to  claim 11  wherein the coating composition contains at least about 10 and less than about 80 weight % of the copolymer or homopolymer based on the total weight of nonvolatile components in the coating composition. 
     
     
         14 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from a polyhydric phenol having one or more aryl or heteroaryl groups in which each aryl or heteroaryl group includes a hydroxyl group attached to the ring and a substituent group attached to the ring at an ortho position relative to the hydroxyl group. 
     
     
         15 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from a polyhydric phenol that includes one or more segments of Formula I: 
       
         
           
           
               
               
           
         
       
       wherein:
 H denotes a hydrogen atom, if present; 
 each R 1  is independently an atom or group having an atomic weight of at least 15 Daltons; 
 v is independently 0 to 4; with the proviso that if v is 0, then n is 1 or the phenylene groups depicted in Formula I join to form a fused ring system; 
 w is 4; 
 R 2 , if present, is a divalent group; 
 n is 0 or 1; with the proviso that if n is 0, the phenylene groups depicted in Formula I can optionally join to form a fused ring system in which case w is 3 and v is 0 to 3; 
 t is 0 or 1; 
 if v is 0 and t is 1, R 2  is a polar linking group or a linking group having a molecular weight of at least 125 Daltons; 
 two or more R 1  or R 2  groups can join to form one or more cyclic groups. 
 
     
     
         16 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from one or more of the diglycidyl ether of 4,4′-methylenebis(2,6-di-t-butylphenol), the diglycidyl ether of 2,2′-methylenebis(4-methyl-6-t-butylphenol), the diglycidyl ether of 4,4′-butylidenebis(2-t-butyl-5-methylphenol), the diglycidyl ether of bis-(3,5-dimethyl-4-hydroxyphenyl)methane, the diglycidyl ether of 2,5-di-t-butylhydroquinone, or a derivative or combination thereof. 
     
     
         17 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from the diglycidyl ether of 4,4′-methylenebis(2,6-dimethylphenol). 
     
     
         18 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from a polyhydric phenol having two or more aryl or heteroaryl groups joined by a polar linking group. 
     
     
         19 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer is derived from a polyhydric phenol having two or more aryl or heteroaryl groups joined by a linking group having a molecular weight of at least 125 Daltons. 
     
     
         20 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer has a number average molecular weight of at least 200 and less than about 8500. 
     
     
         21 . A packaging article according to  claim 1 , wherein the epoxy-functional stabilizer has an epoxy value of about 0.005 to 0.8 equivalents per 100 g of the stabilizer. 
     
     
         22 . A packaging article according to  claim 1 , wherein the coating composition includes at least about 2.5 and less than about 65 weight % of the epoxy-functional stabilizer based on the total weight of nonvolatile components in the coating composition. 
     
     
         23 . A packaging article according to  claim 1 , wherein the coating composition further comprises at least about 3 weight % and less than about 20 weight % of a crosslinker. 
     
     
         24 . A packaging article according to  claim 1 , wherein the coating composition further comprises at least about 20 and less than about 65 weight % organic solvent based on the total weight of the coating composition. 
     
     
         25 . A packaging article according to  claim 1 , wherein the coating composition is substantially free of diphenols having estrogenic activity greater than or equal to that of bisphenol S. 
     
     
         26 . A packaging article according to  claim 1 , wherein the substrate comprises metal. 
     
     
         27 . A packaging article according to  claim 6 , wherein the metal comprises steel, tin-free steel, tin plate, electrolytic tin plate or aluminum.