Coating composition for forming gas barrier layer, gas barrier film, and method for producing gas barrier film

A production method of a gas barrier film formed of a single layer or multiple layers, at least one of said layer or layers that forms or form the gas barrier film being a gas barrier layer that exhibits gas barrier properties, which comprises:

• applying, to a surface of a base material or a surface of a release paper, a coating composition,
• wherein the coating composition comprises:
• a carbonate compound having at least three 5-membered cyclic carbonate groups as Component A;
• and
• an amine compound having at least two amino groups as Component B,
• wherein the carbonate compound and the amine compound react at an equivalent ratio of functional groups, as defined by a following equation, from 0.8 to 1.25 so as to form the polyhydroxyurethane resin, and
• the equivalent ratio of functional groups is obtained by a following formula:
• Equivalent ratio=(mass of the carbonate compound in the coating composition×number of functional groups in the carbonate compound/molecular weight of the carbonate compound)/(mass of the amine compound in the coating composition×number of functional groups in the amine compound/molecular weight of the amine compound),
• where the number of functional groups in the carbonate compound means a number of cyclic carbonate structures in a molecule of the carbonate compound, and
• the number of functional groups in the amine compound means a number of amino groups in a molecule of the amine compound, and
• wherein the carbonate compound is at least one compound selected from the group consisting of

A method for protecting a material from gas present in an environment, comprising:

• covering the material with a gas barrier film so as to prevent the gas from permeating through the gas barrier film,
• wherein the gas barrier film is formed of a single layer or multiple layers,
• the single layer or at least one of said multiple layers exhibits gas barrier properties,
• the layer that exhibits the gas barrier properties comprises a film that comprises a polymer having, as a repeating unit in a main chain of the polymer, at least one chemical structure selected from the group consisting of structures represented by following formulas from (2-1) to (2-4), and
• the polymer is polyhydroxyurethane resin comprising, as monomer units, a carbonate compound having two 5-membered cyclic carbonate groups and an amine compound having at least two amino groups, and
• the polymer is obtained by an addition reaction of the monomer units,
• wherein Xs and Ys represent chemical structures formed of hydrocarbons or aromatic hydrocarbons derived from the monomer units, and
• the structures may each contain at least one hetero atom selected from the group consisting of oxygen, nitrogen, and sulfur,
• wherein the carbonate compound is at least one compound selected from the group consisting of
• where R is hydrogen or CH3,
• the amine compound is selected from the group consisting of linear aliphatic polyamines, cyclic aliphatic polyamines, aliphatic polyamines having aromatic rings, and aromatic polyamines,
• the layer that exhibits the gas barrier properties has a thickness in a range from 0.1 to 100 μm, and
• the polymer film has an oxygen permeation rate of no higher than 50 mL/m2·24 h·atm at a temperature of 23° C. and humidity in a range from 0% to 90% when measured according to JIS K-7126.