Abstract: Provided is a resin film for laminating a metal plate comprising a resin composition including a polyester-based thermoplastic elastomer and a thermoplastic polyester having a glass transition temperature (Tg) of 70° C. or more and 90° C. or less where the thermoplastic elastomer is dispersed in the thermoplastic polyester, wherein a content of the thermoplastic elastomer in the film is 2 to 50 wt %, and an absolute value ?Tg of a difference between a glass transition temperature of the thermoplastic polyester and a glass transition temperature of the film satisfies the following Expression (1): ?Tg<0.5×W??(1) wherein W represents the thermoplastic elastomer content (wt %) in the film.

Abstract: A method of producing a stretched film comprising melt-coextruding a thermoplastic resin A and a thermoplastic resin B to produce a composite film 1 having both-end films 2 of the thermoplastic resin B arranged in parallel at both end portions of the main film 1a of the thermoplastic resin A in the direction of width thereof, stretching the composite film, and cutting and removing both end portions of the stretched film in the direction of width, wherein a film stretch stress value of the both-end films 2 is larger than a film stretch stress value of the main film 1a at the same stretching ratio. This minimizes an increase in the thickness at both end portions of the film in stretching the film and decreases the widths by which both end portions of the expensive resin film are to be cut and removed for producing a film.

Abstract: A method of producing a stretched film comprising melt-coextruding a thermoplastic resin A and a thermoplastic resin B to produce a composite film 1 having both-end films 2 of the thermoplastic resin B arranged in parallel at both end portions of the main film 1a of the thermoplastic resin A in the direction of width thereof, stretching the composite film, and cutting and removing both end portions of the stretched film in the direction of width, wherein a film stretch stress value of the both-end films 2 is larger than a film stretch stress value of the main film 1a at the same stretching ratio. This minimizes an increase in the thickness at both end portions of the film in stretching the film and decreases the widths by which both end portions of the expensive resin film are to be cut and removed for producing a film.