| 摘要 |
PURPOSE: To enable close adhesion to a metal sheet to be stably secured by a method wherein at least one face of the metal sheet is covered by polyester resin of respectively specific melting point, crystallization temperature, and facial orientation factor to form a lower resin layer, and by covering the layer with polyester resin which slightly higher in melting point and facial orientation factor, an upper resin layer is formed. CONSTITUTION: One face or both faces of a metal sheet are covered with a two-layerstructure biaxially oriented polyester film. As thermal characteristics of resin, it is necessary that a lower layer is 190 deg.C-250 deg.C in melting point Tm1 and 100 deg.C to 130 deg.C in crystallization temperature, and melting point Tm2 of an upper layer is melting point Tm1 of the lower layer resin + 10 deg.C to 260 deg.C. Then, the orientation property of the upper layer is 0.100 to 0.169 in facial orientation factor and the facial orientation factor of the lower resin layer is 0 to 0.100. |
