POLYESTER FILM, LAMINATE PRODUCED USING SAID FILM, AND STRUCTURE COMPRISING SAID LAMINATE AND SEALANT LAYER

摘要

[Problem] To provide a laminate which can be used for the external packaging of a battery or the packaging of a medicine, has an excellent property of being molded following to the form of a metal foil and excellent warpage resistance after molding, and does not undergo the delamination between an outer covering film and a metal foil. [Solution] A polyester film, in which the maximum surface height (SRmaxA) on the side of an outermost surface (A) is 1500 to 7000 nm inclusive, the maximum surface height (SRmaxB) on the side of an outermost surface (B) is 5 nm or more and less than 7000 nm, and SRmaxA and SRmaxB fulfil formula (1) shown below, and the each of a fracture strength in the length-wise direction and a fracture strength in the width-wise direction is 200 to 330 MPa inclusive at 25˚C. SRmaxA > SRmaxB•••(1)