PRODUCTION OF MULTILAYERED STRETCHED FILM

摘要

PROBLEM TO BE SOLVED: To impart gas barrier properties and hot water treatment resistance by constituting a multilayered stretched film of at least two layers, that is, a layer composed of a saponified ethylene/vinyl acetate copolymer (EVOH) and a layer composed of a thermoplastic resin (P) having an m.p. higher than that of EVOH and subjecting the same to heat treatment at temp. below the m.p. of (P) before applying predetermined heat treatment thereto. SOLUTION: A multilayered stretched film is heat-treated within a temp. range from the m.p. of EVOH to below the m.p. of a thermoplastic resin (P) of which the m.p. is higher than that of EVOH and subsequently subjected to heat treatment satisfying conditions of t>=0.0889 (Tc-T)<2> -0.373 (Tc-T)+5.1 and -19<=Tc-T<=61 [wherein T is heat treatment temp. (F), t is a treatment time (sec) and Tc is the crystallizing peak temp ( deg.C) of EVOH at a time of the falling of temp. at a speed of 10 deg.C/min by a differential scanning calorimeter].