| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for manufacturing a thermoplastic resin film which can give a film uniform in physical properties in the width direction by reducing the bowing phenomenon. SOLUTION: In the manufacturing process, in which a substantially non-oriented thermoplastic resin sheet is drawn longitudinally and then transversely by a factor of 3.0 or more with a tenter, the above longitudinal drawing is conducted, as the first longitudinal drawing, by drawing 1.1-3.0 times at a temperature of (Tg+30°C) or higher and not higher than Tm and succeedingly passing the film for 0.1 seconds or more through a zone at a temperature of (Tg+10)°C or higher and not higher than Tm, as the subsequent second longitudinal drawing, by drawing 1.1-3.0 times at a temperature of (Tg+20)°C or higher to (Tc+20)°C or lower, and then as the subsequent third longitudinal drawing, by drawing at a temperature of (Tg+10)°C or higher to (Tc+20)°C or lower so as for the combined longitudinal drawing ratio to make 3.1-6.0 times, and the succeeding transverse drawing is conducted at a temperature of (Tg+20)°C or higher to (Tm-20)°C or lower with the tenter. COPYRIGHT: (C)2004,JPO |
