Barrier film and packaging material

1 . A barrier film comprising a barrier coat layer, an inorganic oxide deposition layer, and a substrate layer, in this order,

wherein the barrier coat layer is a coating layer of a barrier coat composition including a metal alkoxide, a water-soluble polymer and a methoxysilane coupling agent,

wherein the metal alkoxide is present in the barrier coat layer in an amount of 62 to 66 wt % based on the amount of solids of the barrier coat layer and consists of at least one metal alkoxide represented by R 1 n M(OR 2 ) m , where R 1 and R 2 are each independently straight or branched alkyl having 1-8 carbon atoms, n is 0 or a positive integer, m is an integer of 1 or more, n+m equals the valence of M, and M is selected from the group consisting of silicon, zirconium, titanium and aluminum, or a hydrolysis product or hydrolytic condensation product thereof,

wherein the water-soluble polymer is present in the barrier coat layer in an amount of 22 to 28 wt % based on the amount of solids of the barrier coat layer and consists of at least one selected from the group consisting of polyvinyl alcohol resin and ethylene vinyl alcohol copolymer,

wherein the methoxysilane coupling agent is present in an amount of 10 to 12 wt % based on the amount of solids of the barrier coat layer and consists of at least one selected from the group consisting of a 3-glycidoxypropylmethyldimethoxysilane and a 3-glycidoxypropyltrimethoxysilane,

wherein the barrier coat layer is produced from a mixture of (A) a first liquid that consists essentially of the metal alkoxide, water, organic solvent, acid, and the coupling agent and (B) a second liquid that consists essentially of the water-soluble polymer, water, and organic solvent, the mixture being applied to the inorganic oxide deposition layer and dried at a temperature in a range of 140° C. to 200° C. for a time of from 1 second to 10 minutes that results in polycondensation,

wherein a solid content ratio (IO value) of the metal alkoxide to the water-soluble polymer is 2.2 to 3.0,

and

wherein the barrier coat layer has a hardness of 1.10 GPa or more and 1.55 GPa or less, and a plastic deformation rate of 21.0% or more.

2 . The barrier film according to claim 1 , wherein

the inorganic oxide deposition layer is an aluminum oxide deposition layer or a silicon oxide deposition layer.

3 . The barrier film according to claim 1 ,

wherein the metal alkoxide is a tetraethoxysilane, and

wherein the water-soluble polymer is a polyvinyl alcohol resin.

4 . The barrier film according to claim 1 , wherein

the barrier film has an oxygen transmission rate of 1.0 cc/m 2 ·atm·day or less, the oxygen transmission rate being measured in accordance with the JIS K7126 method under an environment with a temperature of 23° C. and a humidity of 90% RH.

5 . A packaging material comprising a barrier film according to claim 1 .

6 . The packaging material according to claim 5 , comprising a heat sealing layer, a barrier layer made of the barrier film, and an outer layer, in this order.

7 . The packaging material according to claim 6 , wherein

the heat sealing layer contains a polyolefin resin.

8 . The packaging material according to claim 6 , wherein

the outer layer contains a polyester resin.

9 . The barrier film according to claim 1 , wherein the organic solvent of the first liquid and the second liquid is at least one selected from the group consisting of methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butanol.

10 . The barrier film according to claim 1 , wherein the amount by mass of the first liquid (A) relative to the second liquid (B) in the mixture is 55/45 or more and 62/38 or less.