| 摘要 |
PURPOSE: To improve transparency, heat resistance, dimensional stability, transportability and adhesiveness and to suppress curl by using ethylene-2,6- naphthalate units as the principal repeating units of a substrate film, incorporating element of Mg, etc., and specifying the partial melting temp. CONSTITUTION: A substrate film has ethylene-2,6-naphthalate units as the principal repeating units, contains elements of Mg and P and has 80-170 deg.C partial melting temp. and an easily adhering layer is disposed on at least one side of the film. The elements of Mg and P are preferably contained so as to satisfy 0.1<=M/P<=1.6 (M/P shows the molar ratio of the elements of Mg to P contained in polyester). For example, easily adhering layers are disposed on both sides of the substrate film, a photographic sensitive material layer is disposed on the surface of one of the adhering layers and a magnetic layer is disposed on the surface of the other. |
