Water soluble packaging system, film and method

Abstract

The present invention relates to a bag packaging system composed of a bag sealable to contain a liquid, in which the bag is composed of a continuous outer water soluble film and an inner continuous protective film layer that allows storage therein of a liquid that would chemically or physically react with the water soluble film but is prevented from doing so by the presence of the continuous protective film layer on the inner portion of the bag.

What is claimed is:  
     
         1 . A water soluble bag packaging system for transporting agrichemicals which chemically or physically react with water soluble films, said packaging system comprising a bag containing an agrichemical composition, said bag containing an outer cold water-soluble film layer and an inner barrier layer and the inner barrier layer prevents the agrichemical composition from contacting the water soluble film layer, and wherein when the packaging system is placed in water and said water-soluble film layer dissolves and said inner barrier layer dissolves or disperses into particles small enough to allow the agrichemical to disperse into the water.  
     
     
         2 . The packaging system of  claim 1 , wherein the water-soluble film layer is a film selected from polyvinyl alcohol, 15 polyoxyethylene or a combination of the above.  
     
     
         3 . The packaging system of  claim 1 , wherein the water-soluble film layer is a film selected from the group consisting of polyvinyl alcohol, polyoxyethylene, cellulose derivatives such as methyl cellulose (MC), methylhydroxyethyl (MHEC), methylhydroxypropyl (MHPC), hydroxypropyl (HPC), cellulose, cellulose monoacetate, hydrophobically modified cellulose derivatives, sodium polyacrylate, polylactic acid, lactic acid ethers and esters of polyvinyl alcohol or cellulosics, carrageenan, pectin, combinations of the above, and combinations of the above with starches.  
     
     
         4 . The packaging system of  claim 1 , wherein the agrichemical is selected from the group consisting of fertilizers and pesticides in the form of liquids, gels, dispersions, solutions, suspensions, emulsions, colloids, powders, granules or prills.  
     
     
         5 . The packaging system of  claim 4 , wherein the pesticide is selected from the group consisting of herbicides, insecticides, and fungicides.  
     
     
         6 . The packaging system of  claim 1 , wherein the agrichemical contains one or more components that dissolve, react deleteriously with, or otherwise adversely affect the outer cold water soluble film layer.  
     
     
         7 . The packaging system of  claim 1 , wherein the inner barrier layer has a thickness between 0.25 microns and 25 microns.  
     
     
         8 . The packaging system of  claim 1 , wherein the water-soluble film layer has a thickness between about 12 microns and 200 microns.  
     
     
         9 . The packaging system of  claim 1 , wherein the inner barrier layer is a polymer layer which does not dissolve in water at temperatures above 50° C.  
     
     
         10 . The packaging system of  claim 9 , wherein the polymer layer which does not dissolve in water at temperatures above 50° C. is selected from the group consisting of cellulose derivatives in which the degree of substitution is sufficient to prevent solubility above 5° C. selected from the group consisting of cellulose acetate lactate, cellulose lactate, methylhydroxybutyl cellulose, hydrophobically modified cellulose derivatives and combinations thereof.  
     
     
         11 . The packaging system of  claim 1 , wherein the inner barrier layer is a polymer layer which does not dissolve in water at temperatures below 50° C.  
     
     
         12 . The packaging system of  claim 11 , wherein the polymer layer which does not dissolve in water at temperatures below 50° C. is between 97 and 99.99% hydrolyzed polyvinyl alcohol.  
     
     
         13 . The packaging system of  claim 2 , wherein the inner barrier layer is a polymer layer which dissolves in water but is less reactive than polyvinyl alcohol or polyoxyethylene to most of the agrichemical compositions being packaged.  
     
     
         14 . The packaging system of  claim 13 , wherein the polymer layer which dissolves in water but is less reactive than polyvinyl alcohol or polyoxyethylene to most of the agrichemical compositions is selected from the group consisting of cellulose derivatives which have a DS (degree of substitution) or MS (moles of substitution) that provides solubility in the range of 50° C. and 60° C. or broader such as methyl cellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose, methylethyl cellulose, methylhydroxybutyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydrophobically modified cellulose derivatives, cellulose monoacetate, cellulose acetate lactate, cellulose lactate, karaya gum, guar gum, carrageenan, pectin, gum tragacanth, sodium alginate, gum arabic, and xanthan gum.  
     
     
         15 . The packaging system of  claim 1 , wherein the inner barrier layer disintegrates in water.  
     
     
         16 . The packaging system of  claim 15 , wherein the inner barrier layer which disintegrates in water is selected from the group consisting of soluble acrylic acid polymers, soluble acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, crosslinked polyvinyl alcohols, crosslinked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl alcohol, ethylene vinyl acetate, polyvinylidene chloride, alkali soluble waxes and polyurethanes.  
     
     
         17 . The packaging system of  claim 1 , wherein the inner barrier layer is laminated to the outer water-soluble film layer.  
     
     
         18 . The packaging system of  claim 1 , wherein the inner barrier is co-extruded with the outer water-soluble film layer.  
     
     
         19 . The packaging system of  claim 1 , wherein the inner barrier is coated onto the outer water-soluble film layer.  
     
     
         20 . A method of packaging an agrichemical which chemically or physically reacts with a cold water soluble film comprising: 
 forming a bag from a film comprising an outer layer of the cold water soluble film and an inner barrier layer that does not react with or become dissolved by the agrichemical, the inner barrier layer forming the bag interior and being dispersible or dissolvable in cold water upon dissolving of the cold water soluble layer;    adding a desired amount of the agrichemical into the bag; and    thereafter sealing the bag with the agrichemical contained therein, the barrier layer preventing the agrichemical composition from contacting the outer water soluble film layer.    
     
     
         21 . The method of  claim 20  wherein said barrier layer is cold water soluble.  
     
     
         22 . The method of  claim 20  wherein said barrier layer is cold water insoluble.  
     
     
         23 . A multi-layer water soluble film, suitable for construction of a bag to contain liquid that adversely affects water soluble film comprising: 
 an outer continuous layer of cold water soluble film of sufficient thickness and strength to provide sufficient structural integrity to contain the liquid in a bag once the outer soluble film layer is dissolved.    
     
     
         24 . The film of  claim 23  wherein said continuous layer of cold water insoluble film does not dissolve in water above a temperature of 50° C. and is selected from the group consisting of cellulose derivatives in which the degree of substitution is sufficient to prevent solubility above 50° C.  
     
     
         25 . The film of  claim 24  wherein said cellulose derivatives are selected from the group consisting of cellulose acetate lactate, cellulose lactate, methylhydroxybutyl cellulose and hydrophobically modified cellulose derivatives.  
     
     
         26 . The film of  claim 23  wherein said inner continuous layer does not dissolve in water at temperatures below 50° C.  
     
     
         27 . The multi-layer water soluble film of  claim 26  wherein the inner continuous layer is a polymer film that has been about 97% and 99.9% hydrolyzed polyvinyl alcohol.  
     
     
         28 . The multi-layer water soluble film of  claim 23  wherein the outer water soluble film layer has a thickness of between about 12 microns and 200 microns.  
     
     
         29 . The multi-layer water soluble film of  claim 23  wherein the inner layer of water insoluble film has a thickness of between about 0.25 microns and 15 microns.  
     
     
         30 . The multi-layer water soluble film of  claim 23  wherein the water soluble film layer is selected from the group consisting of polyvinyl alcohol, polyoxyethylene and combinations thereof.  
     
     
         31 . The multi-layer water soluble film of  claim 23  wherein the water soluble film layer is selected from the group consisting of methylcellulose, methylhydroxyethyl cellulose, methylhydroxpropyl cellulose, hydroxypropyl cellulose, cellulose, cellulose monoacetate, hydrophobically modified cellulose derivatives, sodium polyacrylate, polylactic acid, lactic acid ethers, polyvinyl alcohol esters, cellulose esters, carrageenan, pectin, combinations thereof and combinations thereof with starch.  
     
     
         32 . A multi-layer water soluble film, suitable for construction of a bag to contain liquid therein comprising an outer continuous layer of cold water soluble film comprising polyvinyl alcohol; and 
 an inner continuous layer of a cold water soluble film, different than the outer continuous layer and selected from the group consisting of cellulose derivatives which have a degree of substitution that provides cold water solubility, the outer and inner layers providing sufficient structural strength to contain liquids when formed into a bag.    
     
     
         33 . A water soluble bag for containing an agrichemical composition that substantially deleteriously affects cold water soluble film, said bag comprising an outer layer of the cold water soluble film and an inner barrier layer wherein said agrichemical composition does not react with or substantially deleteriously affect the inner barrier layer and the inner barrier layer is capable of preventing the agrichemical composition when stored therein from contacting the water soluble film layer, and wherein when the bag is placed in water with the agrichemical stored therein said water-soluble film layer dissolves and said inner barrier layer dissolves or disperses into particles small enough to allow the agrichemical to disperse into the water.  
     
     
         34 . The bag of  claim 33 , wherein the cold water-soluble film layer is a film selected from the group consisting of polyvinyl alcohol, polyoxyethylene and combinations thereof.  
     
     
         35 . The bag of  claim 33 , wherein the cold water-soluble film layer is a film selected from the group consisting of polyvinyl alcohol, polyoxyethylene, cellulose derivatives selected from the group consisting of methyl cellulose, methylhydroxyethyl cellulose, methylhydroxpropyl cellulose, hydroxypropyl cellulose, cellulose, cellulose monoacetate, hydrophobically modified cellulose derivatives, sodium polyacrylate, polylactic acid, lactic acid ethers polyvinyl alcohol esters, cellulose esters, carrageenan, pectin, combinations of the above, and combinations of the above with starch.  
     
     
         36 . The bag of  claim 33 , wherein the inner barrier layer has a thickness between 0.25 microns and 15 microns.  
     
     
         37 . The bag of  claim 33 , wherein the water-soluble film layer has a thickness between about 12 microns and 200 microns.  
     
     
         38 . The bag of  claim 33 , wherein the inner barrier layer is a polymer film which does not dissolve in water at temperatures above 5° C.  
     
     
         39 . The bag of  claim 38 , wherein the polymer film which does not dissolve in water at temperatures above 5° C. is selected from the group consisting of cellulose derivatives in which the degree of substitution is sufficient to prevent solubility above 5° C. such as cellulose acetate lactate, cellulose lactate, methylhydroxybutyl cellulose and hydrophobically modified cellulose derivatives.  
     
     
         40 . The bag of  claim 33 , wherein the inner barrier layer is a polymer film which does not dissolve in water at temperatures below 50° C.  
     
     
         41 . The bag of  claim 40 , wherein the polymer film which does not dissolve in water at temperatures below 50° C. is between 97 and 99.99% hydrolyzed polyvinyl alcohol.  
     
     
         42 . The bag of  claim 34 , wherein the inner barrier layer is a polymer layer which dissolves in water but is substantially less reactive than polyvinyl alcohol or polyoxyethylene relative to the agrichemical composition to be contained therein.  
     
     
         43 . The bag of  claim 42 , wherein the inner barrier polymer layer which dissolves in water is less reactive than polyvinyl alcohol or polyoxyethylene to most of the agrichemical compositions is selected from the group consisting of cellulose derivatives which have a DS (degree of substitution) or MS (moles of substitution) that provides solubility in the range of about 5° C. and about 60° C.  
     
     
         44 . The bag of  claim 43  wherein said inner barrier polymer layer cellulose derivative is selected from the group consisting of methylcellulose, methylhydroxyethyl cellulose, methylhydroxypropyl cellulose, methylethyl cellulose, methylhydroxybutyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, hydrophobically modified cellulose derivatives, cellulose monoacetate, cellulose acetate lactate, cellulose lactate, karaya gum, guar gum, carrageenan, pectin, gum tragacanth, sodium alginate, gum arabic, xanthan gum and combinations thereof.  
     
     
         45 . The packaging system of  claim 33 , wherein the inner barrier layer disintegrates in water.  
     
     
         46 . The packaging system of  claim 45 , wherein the inner barrier layer which disintegrates in water is selected from the group consisting of soluble acrylic acid polymers, soluble acrylic ester polymers, soluble acrylic acid copolymers, soluble acrylic ester copolymers, soluble copolymers of acrylic acids and esters, crosslinked polyvinyl alcohols, crosslinked cellulose derivatives, ethyl cellulose, nitrocellulose, cellulose butyrate, cellulose acetate butyrate, ethylene vinyl alcohol, ethylene vinyl acetate, polyvinylidene chloride, alkali soluble waxes, and polyurethanes.  
     
     
         47 . The packaging system of  claim 33 , wherein the inner barrier layer is laminated to the outer water-soluble film layer.  
     
     
         48 . The packaging system of  claim 33 , wherein the inner barrier is co-extruded with the outer water-soluble film layer.  
     
     
         49 . The packaging system of  claim 33 , wherein the inner barrier is coated onto the outer water-soluble film layer.