Laminate film and packaging bag using same

Abstract

A laminate film () of the present invention includes a heat sealing layer () composed of a resin composition including, with respect to 20 to 95 parts by weight of a propylene-based polymer (A) having a melting point (Tm) of equal to or higher than 120° C. and equal to or lower than 170° C. as measured by differential scanning calorimetry (DSC), a total of 5 to 80 parts by weight of two or more kinds of copolymers selected from the group consisting of a propylene.1-butene copolymer (B) containing a unit derived from propylene in an amount of 51 to 95 mol % and a unit derived from 1-butene in an amount of 5 to 49 mol %, wherein the total of the unit derived from propylene and the unit derived from 1-butene is 100 mol %, a copolymer (C) of ethylene and an α-olefin having 3 to 20 carbon atoms, and a copolymer (D) of 1-butene and an α-olefin having 3 carbon atoms or 5 to 20 carbon atoms containing a constitutional unit derived from 1-butene in an amount of 50 to 99 mol % and a constitutional unit derived from an α-olefin having 3 carbon atoms or 5 to 20 carbon atoms in an amount of 1 to 50 mol %, wherein the total of the unit derived from 1-butene and the unit derived from the α-olefin is 100 mol %, wherein each of Component (B), Component (C), and Component (D) does not correspond to Component (A), and the total amount of Component (A), Component (B), Component (C), and Component (D) is 100 parts by weight, and a base layer (), in which a surface of the heat sealing layer () opposite to the base layer () has a wet tension of 32 to 45 mN/m.