Multi-layer film and medicine container using the same

Abstract

Disclosed is a multi-layer film comprising: a surface layer having a thickness of 10 to 50 ƒÊm made of an ethylene-ƒ -olefin copolymer halving a density of 0.935 to 0.950 g/cm3, a flexible layer having a thickness of 100 to 200 ƒÊm made of an ethylene-ƒ -olefin copolymer having a density of 0.860 to 0.930 g/cm3, a barrier layer having a thickness of 10 to 80 ƒÊm made of a mixed resin containing 60 to 95% by weight of a cyclic olefin polymer and 5 to 40% by weight of an ethylene-ƒ -olefin copolymer having a density of 0.900 to 0.965 g/cm3, and a seal layer having a thickness of 5 to 80 ƒÊm made of an ethylene-ƒ -olefin copolymer having a density or 0.910 to 0.950 g/cm3. This multi-layer film is suited for use as a material for production of a medicine container 10 because it suppresses adsorption of a medicine by the barrier layer and is also superior in strength and flexibility.

1 . A multi-layer film comprising: 
 a surface layer having a thickness of 10 to 50 μm made of an ethylene-α-olefin copolymer having a density of 0.935 to 0.950 g/cm 3 ,    a flexible layer having a thickness of 100 to 200 μm made of an ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3 ,    a barrier layer having a thickness of 10 to 80 μm made of a mixed resin containing 60 to 95% by weight of a cyclic olefin polymer and 5 to 40% by weight of an ethylene-α-olefin copolymer having a density of 0.900 to 0.965 g/cm 3 , and    a seal layer having a thickness of 5 to 80 μm made of an ethylene-α-olefin copolymer having a density of 0.910 to 0.950 g/cm 3 .    
     
     
         2 . The multi-layer film according to  claim 1 , wherein the flexible layer comprises a material obtained by mixing an ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3  with 20% by weight or less of a high-density polyethylene having a density of 0.940 to 0.970 g/cm 3 .  
     
     
         3 . The multi-layer film according to  claim 1 , wherein the flexible layer comprises a laminate of a layer made of an ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3  and a layer made of a material obtained by mixing an ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3  with 20% by weight or less of a high-density polyethylene having a density of 0.940 to 0.970 g/cm 3 .  
     
     
         4 . The multi-layer film according to any one of  claims 1  to  3 , wherein the ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3  used in the flexible layer is obtained by polymerizing using a metallocene catalyst.  
     
     
         5 . The multi-layer film according to  claim 2 , wherein the ethylene-α-olefin copolymer having a density of 0.860 to 0.930 g/cm 3  used in the flexible layer is a mixture of an ethylene-α-olefin copolymer having a density of 0.860 to 0.910 g/cm 3  and an ethylene-α-olefin copolymer having a density of 0.910 to 0.940 g/cm 3 .  
     
     
         6 . The multi-layer film according to any one of  claims 1  to  5 , wherein the ethylene-α-olefin copolymer having a density of 0.900 to 0.965 g/cm 3  used in the barrier layer is obtained by polymerizing using a metallocene catalyst.  
     
     
         7 . The multi-layer film according to any one of  claims 1  to  6 , which has a total thickness of 130 to 300 μm.  
     
     
         8 . The multi-layer film according to any one of  claims 1  to  7 , wherein the seal layer has a thickness of 5 to 40 μm.  
     
     
         9 . The multi-layer film according to any one of  claims 1  to  7 , wherein the seal layer has a thickness of 40 to 80 μm.  
     
     
         10 . A medicine container which uses the multi-layer film of any one of  claims 1  to  9  so that the surface layer constitutes the outer surface of the medicine container.