| abstract |
An object of the present invention is to provide a method for continuously producing a stretched semi-aromatic polyamide film having excellent heat resistance, heat and humidity resistance, chemical resistance, dimensional stability, and excellent appearance uniformity such as thickness. A polyamide-based resin containing a dicarboxylic acid unit containing 60 to 100 mol% of a terephthalic acid unit and a diamine unit containing 60 to 100 mol% of an aliphatic alkylenediamine unit having 9 carbon atoms is used. . The cooling temperature in the melt extrusion cooling step is 40 ° C to 120 ° C. The preheating temperature Tp in the biaxial stretching step is set to (Tg−20) to (Tg + 40) ° C. Tp and preheating time tp satisfy the relationship of the following formula, the stretching temperature is set to Tg or more, and stretching is performed under the condition of stretching strain rate exceeding 400% / min. 1 × 10 4 × EXP (−0.06 × Tp) ≦ tp ≦ 2 × 10 7 × EXP (−0.1 × Tp) [Selection figure] None |