| 摘要 |
PURPOSE:To improve fire retardancy, heat resistivity, solder resistance and transparency, by coating one or both of the faces of a biaxial oriented polyester film with a film of polyamide-imide or polyimide having a particular thickness so as to produce a laminated structure. CONSTITUTION:One or both of the faces of a biaxial oriented polyester film is coated with a film of polyamide-imide or polyimide to produce a laminated structure. Ratio of thickness of the coat film to that of the polyester film should be 1 or over:25. The polyamide-imide or polyimide used herein is a linear polymer principally composed of repetition units of Formula I or II, respectively. Such polymer is dissolved in a solvent principally composed of N-methyl pyrolidone and the solution is applied on the polyester film by impregnation or coating to produce the coat film. Appearance of the finished surface, molten runaway of the polyester film and autolysis properties can be improved substantially by appropriately selecting sticking viscosity and heating loss of the polymer. |
