GAS BARRIER FILM AND PRODUCTION METHOD THEREFOR, PACKAGING FILM, AND PACKAGING BAG

摘要

This gas barrier film includes: a film base material containing a polyester resin having a butylene terephthalate unit as the main constitutive unit; an inorganic oxide layer containing an inorganic oxide; and a gas barrier cover layer that has been formed using a gas barrier cover layer-forming composition containing at least one selected from the group consisting of a hydroxyl group-containing polymer compound, a metal alkoxide, a silane coupling agent, and hydrolysates thereof. The Tg of the film base material is between 50°C and 70°C inclusive. At a depth position of 50 ± 5 nm from the surface of the gas barrier cover layer on the side facing away from the film base material side, the hardness of the gas barrier cover layer is between 0.6 GPa and 2.0 GPa inclusive.