| 摘要 |
<P>PROBLEM TO BE SOLVED: To control the retardation value (Rth value) in the thickness direction of a cellulose acylate film. <P>SOLUTION: A film raw material is prepared using cellulose acylate as a main component to be extruded to a die by an extruder and discharged as a cellulose acylate film 41 from the die. A casting drum 17 having a surface roughness of 25 nm is used and the temperature thereof is adjusted to 116°C. An elastic drum 18 to be used has a shell 50 with a surface roughness of 25 nm and a thickness Z of 1.5 mm. The contact length Q of the cellulose acylate film 41 with the elastic drum 18 is set to 1.5 cm and the linear pressure received from drums 17 and 18 is set to 90 kg/cm. The cellulose acylate film controlled to the Rth value of 32.3 nm and a fluctuation ratio of 0.5% is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT |
