Frangible film and packaging material

Abstract

As a mono-materialized frangible film having excellent frangibleness, provided is a frangible film having a base material layer containing a cyclic olefin resin on a surface thereof, in which the thickness of the base material layer with respect to the total thickness of the frangible film is 40% or more. For the frangible film, it is preferable that the base material layer contains a cyclic olefin resin having a glass transition temperature of 60° C. or higher. Furthermore, it is preferable that the base material layer is composed of a surface resin layer on the surface side and an inorganic substance-containing layer containing an inorganic substance.

1 . A frangible film comprising a base material layer containing a cyclic olefin resin on a surface thereof,
 wherein a thickness of the base material layer with respect to a total thickness of the frangible film is 40% or more.   
     
     
         2 . The frangible film according to  claim 1 , wherein the base material layer contains a cyclic olefin resin having a glass transition temperature of 60° C. or higher. 
     
     
         3 . The frangible film according to  claim 1 , wherein the base material layer includes a surface resin layer on the surface side and an inorganic substance-containing layer containing an inorganic substance. 
     
     
         4 . The frangible film according to  claim 3 , wherein a content of the inorganic substance is 0.1% by mass or more and 10% by mass or less with respect to a total amount of the frangible film. 
     
     
         5 . The frangible film according to  claim 1 , further comprising a heat seal layer on an opposite side of the surface. 
     
     
         6 . The frangible film according to  claim 1 , wherein a thrust strength when the frangible film is thrust out using a jig having a flat plate-shaped tip part with a diameter of 13 mm, is 35 N or less. 
     
     
         7 . The frangible film according to  claim 1 , further comprising a water vapor and/or oxygen barrier layer. 
     
     
         8 . The frangible film according to  claim 1 , wherein the frangible film serves as a lid material of a package. 
     
     
         9 . A package comprising:
 a container having a recessed part; and   a lid material,   wherein the lid material is the frangible film according to  claim 1 .   
     
     
         10 . The package according to  claim 9 , wherein the package is used for food or beverage packaging, or for medical purposes.