| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical film capable of being used as a protective film for the polarizing plate of a liquid crystal image display device or the like, a phase difference film, the antireflection film of a plasma display or the functional film of every kind of an organic EL display or the like, adaptable to a wide range of a film forming speed or film thickness, enhanced in productivity, improved in quality, extremely stable in film thickness in both of longitudinal and lateral directions, free from thickness irregularity, having no flaw such as color irregularity or the like caused by the thickness irregularity and capable of obtaining excellent optical quality good in flatness. <P>SOLUTION: The optical film is manufactured by casting a dope of fatty acid cellulose ester having an acetyl group and a propionyl group on a support by a casting die 2. A solvent is allowed to flow down to both end parts of the slit of the casting die 2 from the leading end parts of a nozzle 3 and the inner diameters of the leading end parts of the nozzle on both sides of the casting die 2 are respectively set to 0.5-4 mm and the solvation parameter (-▵H<SB>D-BF3</SB>) of the flow-down solvent is set to 15-100[kJ/mol]. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
