Films having a desiccant material incorporated therein and methods of use and manufacture

Abstract

Film structures, packages and methods of making the same are provided wherein the film structures have a desiccant material incorporated into a sealant layer of the films structures. More specifically, the film structure further includes a barrier material incorporated as an internal film layer within the film structure. The film structure is utilized for a package to hold a product that may be sensitive to the presence of moisture. The product may preferably be diagnostic test strips useful in the medical or pharmaceutical field.

We claim:  
     
         1 . A flexible film structure comprising: 
 a barrier layer comprising a barrier material that blocks the transmission of moisture through the film structure; and    a sealant layer comprising a desiccant material.    
     
     
         2 . The flexible film structure of  claim 1  wherein said desiccant material is a chemical desiccant material.  
     
     
         3 . The flexible film structure of  claim 1  wherein said desiccant material is selected from the group consisting of calcium oxide, magnesium sulfate, sodium phosphate di-basic, ammonium chloride, potassium carbonate, potassium aluminum disulfate, magnesium chloride, diammonium sulfate, sodium nitrate, calcium chloride, calcium sulfate, sodium chloride, potassium bromide, molecular sieves, clays and blends of these materials.  
     
     
         4 . The flexible film structure of  claim 1  wherein said barrier material is selected from the group consisting of metal foil, nylon, high density polyethylene or oriented polypropylene, metallized oriented polypropylene, and oriented polyester.  
     
     
         5 . The flexible film structure of  claim 1  further comprising a first tie layer of a polymeric material disposed between said barrier layer and said sealant layer.  
     
     
         6 . The flexible film structure of  claim 5  wherein said first tie layer of polymeric material comprises ethylene acrylic acid copolymer.  
     
     
         7 . The flexible film structure of  claim 5  further comprising: 
 an outer layer of a polymeric material.  
 
     
     
         8 . The flexible film structure of  claim 7  wherein said outer layer comprises a polymeric material selected from the group consisting of PET, oriented polypropylene, polyethylene, nylon, foil, or metallized substrates.  
     
     
         9 . The flexible film structure of  claim 7  further comprising a second tie layer disposed between said outer layer and said barrier layer.  
     
     
         10 . The flexible film structure of  claim 9  wherein said second tie layer comprises ethylene acrylic acid copolymer.  
     
     
         12 . A package comprising: 
 a flexible film wherein said flexible film comprises a barrier layer having a barrier material that blocks the transmission of moisture through the film structure and a sealant layer comprising a desiccant material; and    a space inside the package for a moisture-sensitive product.    
     
     
         13 . The package of  claim 12  wherein said desiccant material is a chemical desiccant material.  
     
     
         14 . The package of  claim 12  wherein said desiccant material is selected from the group consisting of calcium oxide, magnesium sulfate, sodium phosphate di-basic, ammonium chloride, potassium carbonate, potassium aluminum disulfate, magnesium chloride, diammonium sulfate, sodium nitrate, calcium chloride, calcium sulfate, sodium chloride, potassium bromide, molecular sieves, clays and blends of these materials.  
     
     
         15 . The package of  claim 12  further comprising a second flexible film wherein said second flexible film comprises a barrier layer having a barrier material that blocks the transmission of moisture through the second flexible film structure and a sealant layer comprising a second desiccant material, wherein said first and second flexible film structures are heat sealed together to form the package having the space inside the package for said moisture-sensitive product.  
     
     
         16 . The package of  claim 15  wherein said second desiccant material is a chemical desiccant material.  
     
     
         17 . The package of  claim 12  further comprising: 
 an outer layer of polyethylene terephthalate;  
 a first tie layer disposed between said sealant layer and said barrier layer; and  
 a second tie layer disposed between said barrier layer and said outer layer.  
 
     
     
         18 . A method of making a flexible film structure, comprising the steps of: 
 extruding a film layer comprising a blend of a polymeric material and a desiccant material; and    laminating said film layer to a moisture barrier layer.    
     
     
         19 . The method of  claim 18  wherein said film layer is extruded via a blown film extrusion process.  
     
     
         20 . The method of  claim 18  wherein said film layer is extruded via a cast film extrusion process.  
     
     
         21 . The method of  claim 18  wherein said film layer is adhesive laminated to said barrier material.  
     
     
         22 . The method of  claim 18  wherein said film layer is extrusion laminated to said barrier material.  
     
     
         23 . The method of  claim 18  further comprising the steps of: 
 coextruding a tie layer with said film layer comprising the blend of polymeric material and the desiccant material; and  
 laminating said tie layer and said film layer comprising the blend of polymeric material and the desiccant material to said barrier layer.  
 
     
     
         24 . The method of  claim 18  wherein said barrier layer comprises a material selected from the group consisting of metal foil, nylon, high density polyethylene, oriented polypropylene, metallized oriented polypropylene, and metallized polyester.  
     
     
         25 . A package having a space therein for a moisture-sensitive product made from the film structure made from the method of  claim 18  wherein said first layer is a heat sealant layer.  
     
     
         26 . The package of  claim 25  wherein said product comprises a medical diagnostic test strip.  
     
     
         27 . A method of making a flexible film structure, comprising the steps of: 
 extrusion coating a film layer comprising a blend of a polymeric material and a desiccant material to a moisture barrier film layer.    
     
     
         28 . The method of  claim 25  wherein said moisture barrier film layer comprises a material selected from the group consisting of metal foil, nylon, high density polyethylene, oriented polypropylene, metallized oriented polypropylene, and metallized polyester.  
     
     
         29 . The method of  claim 25  wherein said film comprising the blend of the polymeric material and the desiccant material is coextruded with at least one other film layer.  
     
     
         30 . A package having a space therein for a moisture-sensitive product made from the film structure made from the method of  claim 18  wherein said first layer is a heat sealant layer.  
     
     
         31 . A package having a space therein for a moisture-sensitive product made from the film structure made from the method of  claim 27  wherein said first layer is a heat sealant layer.  
     
     
         32 . The package of  claim 31  wherein said product comprises a medical diagnostic test strip.