Gas-barrier laminate

Abstract

A gas-barrier laminate, containing a plastic substrate, an inorganic thin film on at least one surface of the plastic substrate, and a coating layer on a surface of the inorganic thin film is provided. The coating layer comprises at least one resin selected from the group consisting of a polyester resin, an urethane resin, an acrylic resin, an alkoxysilyl group-containing resin, an oxazoline group-containing resin and copolymer resins thereof and a hardness of the coating layer is from 0.1 to 0.5 GPa as measured at 23° C. in atmospheric air by a nano-indentation hardness testing method. When the gas-barrier laminate is further laminated on the coating layer with an unstretched polypropylene film having a thickness of 60 μm and the further obtained laminate subjected to a hydrothermal treatment at 120° C. for 30 min, an oxygen permeability of the further laminate is not more than 50 fmol/m 2 /s/Pa.

1 . A gas-barrier laminate, comprising:
 a plastic substrate;   an inorganic thin film on at least one surface of the plastic substrate; and   a coating layer on a surface of the inorganic thin film; wherein   the coating layer comprises at least one resin selected from the group consisting of a polyester resin, an urethane resin, an acrylic resin, an alkoxysilyl group-containing resin, an oxazoline group-containing resin and copolymer resins thereof,   a hardness of the coating layer is from 0.1 to 0.5 GPa as measured at 23° C. in atmospheric air by a nano-indentation hardness testing method, and   when the gas-barrier laminate is further laminated on the coating layer with an unstretched polypropylene film having a thickness of 60 μm and the further obtained laminate subjected to a hydrothermal treatment at 120° C. for 30 min, an oxygen permeability of the further laminate is not more than 50 fmol/m 2 /s/Pa.   
     
     
         2 . A gas-barrier laminate, comprising:
 a plastic substrate;   an inorganic thin film on at least one surface of the plastic substrate; and   a coating layer on a surface of the inorganic thin film; wherein   the coating layer comprises at least one resin selected from the group consisting of a polyester-based resin, an urethane-based resin, an acrylic resin, an alkoxysilyl group-containing resin, an oxazoline group-containing resin and copolymer resins thereof,   a hardness of the coating layer is from 0.03 to 0.5 GPa as measured at 23° C. in water by a nano-indentation hardness testing method, and when the gas-barrier laminate is further laminated on the coating layer with an unstretched polypropylene film having a thickness of 60 μm and the further obtained laminate subjected to a hydrothermal treatment at 120° C. for 30 min, an oxygen permeability of the further laminate is not more than 50 fmol/m 2 /s/Pa.   
     
     
         3 . A gas-barrier laminate, comprising:
 a plastic substrate;   an inorganic thin film on at least one surface of the plastic substrate; and   a coating layer on a surface of the inorganic thin film; wherein   the coating layer is made of at least one resin selected from the group consisting of a polyester resin, an urethane resin, an acrylic resin, an alkoxysilyl group-containing resin, an oxazoline group-containing resin and copolymer resins thereof,   a ratio of number of carbon atoms derived from carboxyl groups to number of carbon atoms constituting the surface of the coating layer is from 0.005 to 0.1, and   when the gas-barrier laminate is further laminated on the coating layer with an unstretched polypropylene film having a thickness of 60 μm and the further obtained laminate subjected to a hydrothermal treatment at 120° C. for 30 min, an oxygen permeability of the further laminate is not more than 50 fmol/m 2 /s/Pa.   
     
     
         4 . The gas-barrier laminate according to  claim 1 , wherein the ratio of number of carbon atoms derived from carboxyl groups to number of carbon atoms constituting the surface of the coating layer is 0.005 to 0.1. 
     
     
         5 . The gas-barrier laminate according to  claim 1 , wherein a gas-barrier film obtained by forming a printed layer on the coating layer of the gas-barrier laminate and further laminating an unstretched polypropylene film having a thickness of 60 μm on the printed layer exhibits an oxygen permeability of not more than 50 fmol/m 2 /s/Pa after subjecting the gas-barrier film to hydrothermal treatment at 120° C. for 30 min.