High Moisture Barrier Coextruded Blown Film and Laminate and Package Made Therefrom

Abstract

A coextruded multilayer blown film includes a core layer including a blend of ethylene vinyl alcohol copolymer and an active oxygen barrier composition including a blend of a thermoplastic resin having carbon-carbon double bonds substantially in its main chain, a transition metal salt, and an oxygen barrier polymer; two intermediate layers each including polyamide; a first outer layer including high density polyethylene; a second outer layer including olefinic polymer; and two tie layers each adhering an intermediate layer to the first and second outer layers respectively; wherein from 20% to 65% by weight of the coextruded multilayer blown film is made up of high density polyethylene. A package includes a food product in a hermetic pouch made from the coextruded film, optionally adhered to a PET film, such as a printed, or trap-printed PET film, to form a laminate, the pouch having a longitudinal seal and transverse heat seals.

1 .- 20 . (canceled) 
     
     
         21 . A coextruded multilayer blown film comprising:
 a) a core layer comprising a blend of
 i) ethylene/vinyl alcohol copolymer, and 
 ii) an active oxygen barrier composition comprising a blend of a thermoplastic resin having carbon-carbon double bonds substantially in its main chain, a transition metal salt, and an oxygen barrier polymer; 
   b) a first and second intermediate layer each comprising polyamide;   c) a first outer layer comprising high density polyethylene;   d) a second outer layer comprising an olefinic polymer;   e) a first tie layer adhering the first intermediate layer to the first outer layer; and   f) a second tie layer adhering the second intermediate layer to the second outer layer;   wherein from 20% to 65% by weight of the coextruded multilayer blown film comprises high density polyethylene.   
     
     
         22 . The coextruded multilayer blown film of  claim 21  wherein the thermoplastic resin of the active oxygen barrier composition comprises at least one of the units represented by formula (I) and formula (II): 
       
         
           
           
               
               
           
         
       
       wherein R1, R2, R3 and R4 are the same or different, a hydrogen atom, an alkyl group that may be substituted, an aryl group that may be substituted, an alkylaryl group that may be substituted, —COOR5, —OCOR6, a cyano group or a halogen atom, and R3 and R4 may together form a ring via a methylene group or an oxymethylene group, where R5 and R6 are an alkyl group that may be substituted, an aryl group that may be substituted or an alkylaryl group that may be substituted. 
     
     
         23 . The coextruded multilayer blown film of  claim 21  wherein the polyamide of each of the first and second intermediate layers comprises nylon 6. 
     
     
         24 . The coextruded multilayer film of  claim 21  wherein the olefinic polymer of the second outer layer is selected from the group consisting of
 a) a blend of a heterogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc, and a homogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc; 
 b) a blend of a heterogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc, and a high density polyethylene; and 
 c) high density polyethylene. 
 
     
     
         25 . The coextruded multilayer film of  claim 21  wherein at least one of the first and second tie layers comprises an anhydride grafted polymer. 
     
     
         26 . The coextruded multilayer film of  claim 25  wherein at least one of the first and second tie layers comprises an anhydride grafted high density polyethylene. 
     
     
         27 . The coextruded multilayer film of  claim 26  wherein each of the first and second tie layers comprises a blend of
 a) from 55% to 90% by weight of an anhydride grafted high density polyethylene; and 
 b) from 10% to 45% by weight of high density polyethylene. 
 
     
     
         28 . The coextruded multilayer blown film of  claim 21  wherein the first outer layer and the first tie layer each comprises at least 80%, by weight of the respective layer, high density polyethylene. 
     
     
         29 . The coextruded multilayer blown film of  claim 21  wherein the first outer layer and the first and second tie layers each comprises at least 80%, by weight of the respective layer, high density polyethylene. 
     
     
         30 . The coextruded multilayer blown film of  claim 21  wherein the first outer layer and the first and second tie layers each comprises at least 80%, by weight of the respective layer, high density polyethylene; and the second outer layer comprises from 20% to 60%, by weight of the second outer layer, high density polyethylene. 
     
     
         31 . A package comprises:
 a) a food product, and   b) a hermetic pouch in which the food product is disposed, the hermetic pouch having a longitudinal seal and transverse heat seals, the pouch comprising a coextruded multilayer blown film comprising
 (i) a core layer comprising a blend of ethylene vinyl alcohol copolymer, and an active oxygen barrier composition comprising a blend of a thermoplastic resin having carbon-carbon double bonds substantially in its main chain, a transition metal salt, and an oxygen barrier polymer; 
 (ii) a first and second intermediate layer each comprising polyamide; 
 (iii) a first outer layer comprising high density polyethylene; 
 (iv) a second outer layer comprising an olefinic polymer; 
 (v) a first tie layer adhering the first intermediate layer to the first outer layer; and 
 (vi) a second tie layer adhering the second intermediate layer to the second outer layer; 
 wherein from 20% to 65% by weight of the coextruded multilayer blown film comprises high density polyethylene. 
   
     
     
         32 . The package of  claim 31  wherein the thermoplastic resin of the active oxygen barrier composition comprises at least one of the units represented by formula (I) and formula II: 
       
         
           
           
               
               
           
         
       
       wherein R1, R2, R3 and R4 are the same or different, a hydrogen atom, an alkyl group that may be substituted, an aryl group that may be substituted, an alkylaryl group that may be substituted, —COOR5, —OCOR6, a cyano group or a halogen atom, and R3 and R4 may together form a ring via a methylene group or an oxymethylene group, where R5 and R6 are an alkyl group that may be substituted, an aryl group that may be substituted or an alkylaryl group that may be substituted. 
     
     
         33 . The package of  claim 31  wherein the polyamide of each of the first and second intermediate layers comprises nylon 6. 
     
     
         34 . The package of  claim 31  wherein the olefinic polymer of the second outer layer is selected from the group consisting of
 a) a blend of a heterogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc, and a homogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc; 
 b) a blend of a heterogeneous ethylene/alpha-olefin copolymer having a density of less than 0.940 grams/cc, and a high density polyethylene; and 
 c) high density polyethylene. 
 
     
     
         35 . The package of  claim 31  wherein at least one of the first and second tie layers comprises an anhydride grafted polymer. 
     
     
         36 . The package of  claim 35  wherein at least one of the first and second tie layers comprises an anhydride grafted high density polyethylene. 
     
     
         37 . The package of  claim 36  wherein at least one of the first and second tie layers comprises a blend of
 a) from 55% to 90% by weight of an anhydride grafted high density polyethylene; and 
 b) from 10% to 45% by weight of high density polyethylene. 
 
     
     
         38 . The package of  claim 31  wherein the first outer layer and the first tie layer each comprises at least 80%, by weight of the respective layer, high density polyethylene. 
     
     
         39 . The package of  claim 31  wherein the first outer layer and the first and second tie layers each comprises at least 80%, by weight of the respective layer, high density polyethylene. 
     
     
         40 . The package of  claim 31  wherein the first outer layer and the first and second tie layers each comprises at least 80%, by weight of the respective layer, high density polyethylene; and the second outer layer comprises from 20% to 60%, by weight of the second outer layer, high density polyethylene.