Multi-layer laminate structure

Abstract

A multi-layer structure for fabricating a beverage container having two or more layers comprising paperboard and at least one barrier layer formed of a blend of polyethylene, nylon and a compatibilizer selected from maleic anhydride modified polyethylene, zinc neutralized ethylene methacrylic acid, sodium neutralized ethylene methacrylic acid, ethylene acrylic acid copolymers, ethylene methacrylic acid copolymers and epoxy functionalized polyethylene. The containers or cartons made from the laminates containing the blend offer substantial heat resistance and exhibit superior abuse resistance. The method and process of making the blend and multi-layer structure are also disclosed.

We claim:  
     
         1 . Process for producing a compatibilized blend of polyethylene and nylon which comprises forming a mixture of polyethylene, nylon, and a compatibilizer which is a member selected from the group consisting of maleic anhydride modified polyethylene, zinc neutralized ethylene methacrylic acid, sodium neutralized ethylene methacrylic acid, ethylene methacrylic acid copolymers, ethylene acrylic acid copolymers and epoxy functionalized polyethylene and heating said mixture in an extruder to a temperature which is sufficient to form a homogeneous melt blend of said polyethylene, nylon and compatibilizer.  
     
     
         2 . A process according to  claim 1  which comprises forming said blend by separately introducing each of said polyethylene, nylon and compatibilizer into said extruder for forming said mixture in situ.  
     
     
         3 . A process according to  claim 1  which comprises forming said blend by dry mixing said polyethylene, nylon and compatibilizer prior to introduction into the extruder.  
     
     
         4 . A compatibilized blend of polyethylene, nylon and a compatibilizer which is a member selected from the group consisting of maleic anhydride modified polyethylene, zinc neutralized ethylene methacrylic acid, sodium neutralized ethylene methacrylic acid, ethylene methacrylic acid copolymers, ethylene acrylic acid copolymers and epoxy functionalized polyethylene.  
     
     
         5 . A compatibilized blend according to  claim 4  wherein said polyethylene is a member selected from the group consisting of low density polyethylene, linear low density polyethylene, metallocene polyethylene and mixtures thereof.  
     
     
         6 . A compatibilized blend according to  claim 4  wherein said nylon is a member selected from the group consisting of nylon 6, nylon 7, nylon 8, nylon 11, nylon 12, nylon 6-6, nylon 6-9, nylon 6-10, copolymer of nylon 6 and nylon 6-6, amorphous nylon, MXD6 nylon, nylon nanoclay composite and mixtures thereof.  
     
     
         7 . A compatibilized blend according to  claim 4  wherein said nylon is nylon 6.  
     
     
         8 . A compatibilized blend according to  claim 4  wherein said polyethylene is low density polyethylene and said nylon is nylon 6.  
     
     
         9 . A compatibilized blend according to  claim 4  wherein said compatibilizer is present in said blend in an amount of about 0.1 wt. % to about 15 wt. %.  
     
     
         10 . A compatibilized blend according to  claim 4  wherein said blend contains less than about 40 wt. % of said polyethylene.  
     
     
         11 . A compatibilized blend according to  claim 4  wherein said blend contains more than about 60 wt. % of said nylon.  
     
     
         12 . A compatibilized blend according to  claim 4  wherein said compatibilizer is present in an amount of about 0.1 wt. % to about 15 wt. % said polyethylene is present in an amount of less than about 40 wt. % and said nylon is present in an amount of more than about 60 wt. %.  
     
     
         13 . A multi-layer laminate material having two or more layers comprising at least one layer comprising a compatibilized blend according to  claim 4 .  
     
     
         14 . A laminated material comprising a paperboard substrate and a layer formed of a compatibilized blend according to  claim 4  deposited on one surface of the paperboard.  
     
     
         15 . A beverage container comprising a multi-layered structure comprising a paperboard substrate and at least one barrier layer formed of a compatibilized blend according to  claim 4 .  
     
     
         16 . A beverage container according to  claim 15  wherein said barrier layer is deposited on one surface of said paperboard.