CPC B32B 27/08 (2013.01) [B32B 25/08 (2013.01); B32B 25/14 (2013.01); B32B 27/302 (2013.01); B32B 27/306 (2013.01); B32B 27/40 (2013.01); C08J 5/18 (2013.01); B29C 48/08 (2019.02); B29K 2023/083 (2013.01); B29K 2075/00 (2013.01); B29K 2995/0067 (2013.01); B32B 2250/05 (2013.01); B32B 2250/24 (2013.01); B32B 2250/42 (2013.01); B32B 2307/7244 (2013.01); B32B 2439/70 (2013.01); C08J 2329/04 (2013.01); C08J 2425/04 (2013.01); C08J 2475/04 (2013.01)] | 11 Claims |
1. A film, comprising:
at least one gas barrier layer (A) formed from a polymer comprising a gas barrier resin having a glass transition temperature of 70° C. or below; and
at least one elastomer layer (B) formed from a polymer comprising an elastomer, wherein the at least one elastomer layer (B) comprises at least one elastomer layer (B1) formed from a polymer comprising a hydrocarbon elastomer, wherein at least one of the at least one elastomer layer (B1) is laminated as an outermost layer;
wherein
the film has an oxygen permeability coefficient of 200 mL/(m2·day·atm) or less, and
in a case where tension is applied to stretch the film in a machine direction (MD) at 20° C. such that a twofold increase in length of the film is kept for 30 seconds, and then the tension is released, a ratio L2/L1 is 1.5 or less, where L1 denotes a length of the film in the MD prior to application of the tension and L2 denotes a length of the film in the MD subsequent to release of the tension, and
wherein the film is produced by a film forming apparatus comprising, in this order: an extrusion die for extruding polymers which form each layer; and a first conveyor roller and a second conveyor roller for conveying a laminate formed from the polymers extruded from the extrusion die,
wherein air pressure at an air slit provided between the extrusion die and the first conveyor roller is 0.01 MPa or more and 0.45 MPa or less, and a draw ratio (R2/R1), being a ratio of a rotational speed (R2) of the second conveyor roller to a rotational speed (R1) of the first conveyor roller, is 1.0 or more and 1.5 or less.
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