Barrier film and packaging material

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 R1nM(OR2)m, where R1 and R2 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.