Modified container

Abstract

The gas permeance of polyester bottles or other packaging article is improved by the combination of an oxygen scavenging material provided in the wall of the article and an external barrier to gas flow.

What we claim is:  
     
         1 . A packaging article having at least a wall constructed of a polyester having an oxygen scavenging material therein and having an external barrier to gas flow thereon.  
     
     
         2 . The article of  claim 1  wherein said oxygen scavenging material is uniformly distributed through the thickness of the wall.  
     
     
         3 . The article of  claim 2  wherein said oxygen scavenging material is polyester copolymer comprising predominantly polyester segments and an oxygen scavenging amount of polyolefin oligomer segments.  
     
     
         4 . The article of  claim 3  wherein said copolymer is capable of absorbing at least 0.4 cc of oxygen per gram of copolymer at temperature in the range of about 4° to about 60° C.  
     
     
         5 . The article of  claim 3  wherein said polyolefin oligomer is selected from the group consisting of polypropylene, poly(4-methyl)1-pentene unhydrogenated polybutadiene, and mixtures thereof.  
     
     
         6 . The article of  claim 5  wherein the polyolefin segments comprise from about 0.5% to about 12 wt % of the polyester copolymer.  
     
     
         7 . The article of  claim 1  wherein the external barrier comprises a thin coating of an epoxy-amine resin.  
     
     
         8 . The article of  claim 8  wherein the epoxy-amine resin has an amine hydrogen to epoxy equivalent cure ratio lower than 1.5 to 1.  
     
     
         9 . The article of  claim 1  wherein the external barrier coating is a thin coating of silica.  
     
     
         10 . The article of  claim 1  wherein the external barrier is applied to the whole external surface of the article.  
     
     
         11 . The article of  claim 1  wherein said polyester is polyethylene-terephthalate.  
     
     
         12 . The article of  claim 11  wherein said article is a bottle.