Closure Liner Composition With Improved Oxygen Reduction

Abstract

Disclosed is a closure liner composition comprising a mixture (or blend) of a thermoplastic polymer, an oxygen barrier polymer, and a particulate oxygen scavenging material. The oxygen barrier polymer preferably comprises polyisobutylene. The particulate oxygen scavenging material preferably is selected from the group consisting of an alkali metal salt of sulfite, ascorbate, isoascorbate, and a mixture of two or more of these materials. The closure liner composition may be used to fabricate a liner for a closure (e.g., a metal crown used to cap a bottle) that provides superior oxygen reduction properties and improved shelf life.

1 . A closure liner composition comprising a thermoplastic polymer, an oxygen barrier polymer, and a particulate oxygen scavenging material. 
     
     
         2 . The closure liner composition according to  claim 1  wherein the oxygen barrier polymer comprises polyisobutylene, and wherein the particulate oxygen scavenging material is selected from the group consisting of an alkali metal sulfite, an alkali metal ascorbate, an alkali metal isoascorbate, and a mixture of two or more of these materials. 
     
     
         3 . The closure liner composition according to  claim 1  comprising, by weight of the composition, 40% to 80% of a thermoplastic polymer, 5% to 50% of an oxygen barrier polymer comprising polyisobutylene, and 1% to 30% of a particulate oxygen scavenging material selected from the group consisting of an alkali metal sulfite, an alkali metal ascorbate, an alkali metal isoascorbate, and a mixture of two or more of these materials. 
     
     
         4 . The closure liner composition according to  claim 1  comprising, by weight of the composition, 50% to 70% of a thermoplastic polymer, 10% to 30% of an oxygen barrier polymer comprising polyisobutylene, and 3% to 20% of a particulate oxygen scavenging material selected from an alkali metal sulfite, an alkali metal ascorbate, an alkali metal isoascorbate, and a mixture of two or more of these materials. 
     
     
         5 . The closure liner composition according to any preceding claim wherein the thermoplastic polymer comprises one or more polymers selected from the group consisting of polyethylene, polypropylene, ethylene propylene copolymer, styrene butadiene rubber, carboxylated styrene butadiene, polyisoprene, styrene isoprene styrene block copolymer, styrene butadiene styrene block copolymer, styrene ethylene butylene styrene block copolymer, ethylene vinyl acetate copolymer, ethylene (meth) acrylate copolymer, ethylene vinyl alcohol copolymer, vinyl chloride homopolymer or copolymer, styrene acrylic polymer, polyamide, and vinyl acetate polymer, and blends of one or more of these. 
     
     
         6 . The closure liner composition according to any preceding claim wherein the oxygen barrier polymer consists essentially of polyisobutylene. 
     
     
         7 . The closure liner composition according to any preceding claim wherein the particulate oxygen scavenging material comprises sodium sulfite. 
     
     
         8 . A closure for a container, wherein the closure includes a closure liner fabricated from the closure liner composition according to any of  claims 1  to  7 . 
     
     
         9 . A metal crown for a beverage container, wherein the metal crown includes a closure liner fabricated from the closure liner composition according to any of  claims 1  to  7 . 
     
     
         10 . A container filled with a product, wherein the container is capped by a closure, wherein the closure includes a closure liner fabricated from the closure liner composition according to any of  claims 1  to  7 . 
     
     
         11 . A bottle filled with a beverage, wherein the bottle is capped by a metal crown that includes a liner fabricated from a closure liner composition according to any of  claims 1  to  7 .