| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a retardation film which includes a haze value of 0.5 or less and Re (retardation value) of 50 nm or more. SOLUTION: Dope is cast onto a casting drum. A casting film is cooled by the casting drum. The casting film is solidified. The casting film containing a large amount of solvent is peeled as a film. The film 12 is dried in a tenter 15. The film 12 is dried until the residual amount of solvent becomes 60 wt.%. The film 12 is dried by blowing gas at a temperature of 105°C or lower until the residual amount of solvent becomes 10 wt.% or less. The glass transition temperature of cellulose acylate in the film 12 in which the residual amount of solvent is 10 wt.% is denoted by Tg°C. The width of the film 12 is increased while the temperature of the film 12 is within a range between (Tg+10)°C and (Tg+60)°C to obtain a retardation film 14. COPYRIGHT: (C)2010,JPO&INPIT |
