Patent ID: 7648737

Claim:
A method of producing a stretched laminate film with oxygen-gas barrier properties, which includes a layer (a) formed from a composition of a polycarboxylate-based polymer (A) and a plasticizer (B), a layer (c) containing a multivalent metal compound (C) and a layer (b) formed from a thermoplastic resin, and which includes at least one layer forming unit where the layer (a) and the layer (c) are adjacent to each other, the method comprising the steps of: superposing at least one of the layer (a) and the layer (c) on at least one surface of the layer (b) by a coating process; and stretching a laminate film including the layer (a), the layer (b) and the layer (c) in an integrated manner and with a surface stretch ratio of 1.1 to 100.