Bag-in-box film form packaging refrigerated liquids

Abstract

Multi-layer films for making bags for containing flowable materials, in particular to large bags for dairy products. The multi-layer films have an outer and an inner sealant layer and a core layer and optionally, an interposed layer positioned between the outer sealant layer and the core layer and between the core layer and the inner sealant layer. The outer and inner sealant layers contain an ethylene/a-olefin interpolymer composition and the intermediate layer optionally contains this interpolymer composition.

1 . A multilayer film for making pouches containing flowable materials, said multi-layer film comprising the following layers in order, from an at least one inner sealant-layer to at least one core layer and to an at least one outer sealant-layer for packaging liquids comprising:
 (A) at least one outer sealant layer and at least one inner sealant layer, each layer comprising an ainterpolymer composition comprises from 50-75% by weight of a first ethylene/a-olefin copolymer fraction having a density in the range of 0.894 to 0.908 g/cc; a melt index in the range of 0.2 to 1 g/10 min.; and from 25 to 50 percent by weight of a second ethylene,a-olefin copolymer fraction and wherein the interpolymer has a density in the range of 0.910 to 0.924 g/cc and a melt index in the range from 0.5 to 2 g/10 min: a zero shear viscosity ratio (ZSVR) in the range of from 1.15 to 2.5; a molecular weight distribution, expressed as the ratio of the weight average molecular weight (Mw/Mn), in the range of 2.0 to 4.0;   (B) at least one core layer selected from the group consisting of: 
 (1) a core layer comprising linear low density polyethylene, ethylene/octene-1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc: 
 (2) a core layer comprising 30-100% by weight of linear low density polyethylene, ethylene/octene -1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc and 70-0% of ethylene butane copolymer having a melt index of 1.0 g/10 min and a density of 0.918; and 
 (3) a core layer comprising 30-100% by weight of linear low density polyethylene, ethylene/hexene -1 copolymer having a melt index of 1.0 g/10 min. and density of 0.916 g/cc. and 70-0% by weight of a linear low density ethylene/hexene copolymer having a melt index of 1.0 g/10 min. and a density of 0.918 g/cc . 
   
     
     
         2 . The multilayer film of  claim 1  wherein the at least one outer sealant layer, the at least one inner sealant layer and the core layer individually comprise a single layer up to and including eight layers. 
     
     
         3 . The multilayer film of  claim 2  wherein the ethylene/a-olefin interpolymer comprises a polymer fraction of linear low density polyethylene and a second copolymer fraction of ethylene/octene- 1 copolymer and the interpolymer having a density of 0.915 g/cc and a melt index of 0.85 g/10 min. 
     
     
         4 . The multilayer film of  claim 3  wherein the at least one core layer comprises a linear low density polyethylene, ethylene/octene-1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.91 6 g/cc. 
     
     
         5 . The multilayer film of  claim 3  wherein the at least one core layer comprises 30-100% by weight of ethylene/octene -1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc and 70-0% of ethylene butane copolymer having a melt index of 1.0 g/10 min and a density of 0.918 and the copolymers are in a ratio of 40/60. 
     
     
         6 . The multilayer film of  claim 3  wherein the at least one core layer comprises 30-100% by weight of ethylene/hexene -1 copolymer having a melt index of 1.0 g/10 min. and density of 0.916 g/cc. and 70-0% by weight of ethylene/hexene copolymer having a melt index of 1.0 g/10 min. and a density of 0.918 g/cc and the copolymers are a weight ratio of 40/60. 
     
     
         7 . A multilayer film for making pouches containing flowable materials, said multi-layer film comprising the following layers in order, from an at least one inner sealant-layer to an at least one interposed layer to an at least one core layer to a second interposed layer and to an outer sealant-layer for packaging liquids comprising: 
 (A) at least one outer sealant layer and at least one inner sealant layer, each layer comprising an ultra-low density polyethylene, ethylene /octene-1 copolymer having a melt index of 0.85 g/10 min and a density of 0.912 g/cc. and an ethylene/a-olefin interpolymer composition comprising linear low density polyethylene, ethylene /octene -1 copolymer having a melt index of 0.85 g/10 min.ad a density of 0.920 g/cc;   (B) at least one interposed layer position between the at least one core layer and the at least on outer sealant layer and the at least one second interposed layer between the at least one core layer and the second outer sealant layer comprising an ethylene/a-olefin interpolymer composition comprises from 50-75% by weight of a first ethylene/a-olefin copolymer fraction having a density in the range of 0.894 to 0.908 g/cc: a melt index in the range of 0.2 to 1 g/10 min.; and from 25 to 50 percent by weight of a second ethylene/a-olefin copolymer fraction and wherein the interpolymer has a density in the range of 0.910 to 0.924 g/cc and a melt index in the range from 0.5 to 2 g/10 min; a zero shear viscosity ratio (ZSVR) in the range of from 1.15 to 2.5: a molecular weight distribution, expressed as the ratio of the weight average molecular weight (Mw/Mn), in the range of 2.0 to 4.0;   (C) at least one core layer selected from the group consisting of 
 (1) a core layer comprising linear low density polyethylene, ethylene/octene-1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc; 
 (2) a core layer comprising 30-100% by weight of linear low density polyethylene, ethylene/octene -1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc and 70-0% of ethylene butane copolymer having a melt index of 1.0 g/10 min and a density of (0.918; and 
 (3) a core layer comprising 30-100% by weight of linear low density polyethylene, ethylene/hexene -1 copolymer having a melt index of 1.0 g/10 min. and density of 0.916 g/cc. and 70-0% by weight of linear low density polyethylene, ethylene/hexene copolymer having a melt index of 1.0 g/10 min. and a density of 0.918 g/cc . 
   
     
     
         8 . The multilayer film of  claim 7  wherein the at least one outer sealant layer, the at least one inner sealant layer, the core layer and the interposed layers between the sealant layers and the core layer individually comprise a single layer up to and including eight layers. 
     
     
         9 . The multilayer film of  claim 7  wherein the at least one core layer comprises 30-100% by weight of linear low density polyethylene, ethylene/octene -1 copolymer having a melt index of 1.0 g/10 min. and a density of 0.916 g/cc and 70-0% of ethylene butane copolymer having a melt index of 1.0 g/10 min and a density of 0.918 in a weight ratio of 40/60. 
     
     
         10 . The multilayer film of  claim 7  wherein the at least one core layer comprises 30-100% by weight of linear low density polyethylene, ethylene/hexene -1 copolymer having a melt index of 1.0 g/10 min. and density of 0.916 g/cc. and 70-0% by weight of linear low density polyethylene, ethylene/hexene copolymer having a melt index of 1.0 g/10 min. and a density of 0.918 g/cc in a weight ratio of 40/60. 
     
     
         11 . A bag for containing flowable liquid formed of the multilayer film of  claim 1 . 
     
     
         12 . The bag of  claim 11  wherein the flowable material is a refrigerated dairy product. 
     
     
         13 . A bag for containing flowable liquid formed of the multilayer film of  claim 7 . 
     
     
         14 . The bag of  claim 13  wherein the flowable material is a refrigerated dairy product. 
     
     
         15 . A process for filling bags with flowable product wherein the bags are formed from the multilayer film of  claim 1 . 
     
     
         16 . A process for filling bags with flowable product wherein the bags are formed from the multilayer film of  claim 7 .