| 摘要 |
PROBLEM TO BE SOLVED: To suppress scratches and wrinkles of a stretched film obtained by subjecting a cellulose acylate film preliminarily heated by a plurality of preheating rollers to stretching machining in a longitudinal direction by a the difference of peripheral speeds of a pair of rollers. SOLUTION: V<SB>n+1</SB>is set so as to become in a range≥0.01×ΔT<SB>n</SB>×V<SB>n</SB>and≤0.2×ΔT<SB>n</SB>×V<SB>n</SB>when the peripheral speed of the (n+1)th roller from the upstream side of the plurality of preheating rollers 22, 24, 26, 28 and uppermoststream roller 32 of the pair of rollers is set to be V<SB>n+1</SB>(m/min), the peripheral speed of the nth roller present in the upstream side by one roller from the (n+1)th roller is set to be V<SB>n</SB>(m/min), and the temperature difference at which the cellulose acylate film heat-changes before and after contacting by contacting the nth roller is set to beΔTn (°C), and a time t<SB>n</SB>when the cellulose acylate film 12 contacts each preheating roller of the plurality of preheating rollers 22, 24, 26, 28 is set to be in a range≥one sec. and≤10 sec. COPYRIGHT: (C)2008,JPO&INPIT |
