Patent attributes
The present invention makes it possible to provide a film exhibiting an excellent oxygen-gas barrier properties and an excellent moisture proofness, the film containing at least a multivalent metal salt of a polycarboxylate-based polymer (A), the film having the density which is not lower than 1.80 g/cm3; the surface ratio α [the peak surface S1 (3700 to 2500 cm−1)/the peak surface S2 (1800 to 1500 cm−1)] of an infrared absorption spectrum which is not larger than 2.5; and the peak ratio β [the peak A1 (1560 cm−1)/the peak A2 (1700 cm−1)] of the infrared absorption spectrum which is not smaller than 1.2, by means of applying a solution containing the polycarboxylate-based polymer (A) and the multivalent metal compound (B) to a substrate, thus obtaining a dried film, and thereafter treating the dried film with heat under predetermined conditions. Accordingly, the present invention makes it possible to provide packaging materials and packaging containers for not only foods which are required not to contact an oxygen gas, but also foods, beverages, chemicals, pharmaceuticals, and precision metal parts such as electronic parts, as well as members of electronic equipment, all of which are required to be protected from moisture.
