Abstract: A sealant film including a surface resin layer (A), an adhesive resin layer (B), a release resin layer (C), and a heat seal resin layer (D) that are laminated is provided. The adhesive resin layer (B) contains a thermoplastic elastomer (b1) and a tackifier resin (b2). The release resin layer (C) contains a certain amount of an ethylene ionomer (c1) with a polar group concentration exceeding 5.5 mol % and an ethylene ionomer (c2) with a polar group concentration of 5.5 mol % or less in a resin component contained in the release resin layer (C). The heat seal resin layer (D) contains a certain amount of an olefin resin (d1) and a thermoplastic elastomer (d2) in a resin component contained in the heat seal resin layer (D).

Abstract: A sealant film including a layered film that includes a sealable resin layer including a heat seal layer (A) as a surface layer; and a base material layer (B), in which the sealable resin layer is formed of a resin layer having a 1% secant modulus of 200 MPa or less and has a thickness of 15 ?m to 50 ?m, the heat seal layer (A) has a 1% secant modulus of 20 MPa to 45 MPa and a thickness of 5 ?m or more, and the base material layer (B) has a 1% secant modulus of 250 MPa or more and a thickness of 1 ?m to 30 ?m. Thus, the sealant film not only has good adhesion and suitable openability with respect to the surface to be adhered to but also achieves excellent pressure resistance that prevents the occurrence of opening even under high-pressure treatment.