| abstract |
(57) [Problem] To provide a composite film having excellent mechanical strength and chemical resistance, and also having excellent gas barrier properties and water vapor barrier properties. SOLUTION: At least one layer film made of a cyclic olefin-based polymer which contains a repeating unit having an alicyclic structure and at least 30% by weight of the repeating unit has no norbornane structure, and a polyvinyl alcohol-based film A composite film comprising at least one layer of a polymer film. The composite film is formed by laminating a polyvinyl alcohol-based polymer film on at least one surface of the above-mentioned cyclic olefin-based polymer film via an adhesive layer if necessary, and by heat-pressing or by pressing the above-mentioned cyclic olefin-based polymer, polyvinyl alcohol-based polymer film. Manufactured by coextrusion of the polymer, and optionally the adhesive. |