| 摘要 |
PURPOSE:To provide thermoplastic polyimide-based tubular film, which is produced by melt-extruding material mainly made of brand-new type thermoplastic polyimide-based resin different from the conventional polyimide-based resin in the form of film. CONSTITUTION:Polyimide-based resin with water content of 30 ppm or less is melt-extruded in the form of tube with an extruder, the inner surface of the cylinder of which is lined by special alloy and at the tip of the cylinder and near the head of which filters are arranged. Next, after being cooled by cooling system with a water tank, the resultant tubular resin is stretched and heat-set. By being turned into film as described above, thermoplastic polyimide- based tubular film having excellent dimensional accuracy and film thickness accuracy is obtained, resulting in expecting to be used in wide field. |
