| abstract |
PROBLEM TO BE SOLVED: To provide a film for a membrane switch which comprises polyethylene-2,6-naphthalenedicarboxylate as a main component and has excellent permanent deformation resistance when used at high temperatures. SOLUTION: This is a biaxially stretched film containing polyethylene-2,6-naphthalenedicarboxylate as a main component, and has an endothermic peak within a temperature range of 110 to 160 ° C measured by a differential scanning calorimeter (DSC). Wherein the endothermic energy is 0.4 mJ / mg or more. |