Title:
光学フィルムの製造方法
Document Type and Number:
Japanese Patent JP4273955
Kind Code:
B2
Abstract:
To provide an optical film which is made of a cellulose ester film having a uniform and excellent phase difference compensation performance and a viewing angle enlarging function almost all over the region of the film, and to provide a production method of the optical film. The optical film is made of a cellulose ester film of which the retardation Ro of the in-plane direction is 40 to 100 nm and the retardation Rt of the thickness direction is 50 to 200 nm. In the production method of the optical film according to a solution casting film forming method, a cellulose ester solution (dope) is casted on a substrate, a film (web) is stripped from the substrate, thereafter, the film is stretched in the width direction (TD direction) and, at the same time, is stretched in the machine direction (MD direction) under such conditions that remaining solvent exists while being dried. Therein, the remaining solvent amount upon the stretching after the film (web) is stripped from the substrate is 5 to 10% and the relaxation contraction of the MD direction in the range of the TD direction stretching ratio(%)*0.1 to the TD direction stretching ratio(%)*0.3 is caused concurrently with the TD direction stretching.
Inventors:
Keisuke Nagashima
Application Number:
JP2003423361A
Publication Date:
June 03, 2009
Filing Date:
December 19, 2003
Export Citation:
Assignee:
Konica Minolta Opto Co., Ltd.
International Classes:
G02B5/30; B29C41/24; B29C41/28; B29C41/34; B29C41/52; B29C55/14; B29C55/16; B29C69/02; C08J5/18; G02B1/04; B29K1/00; B29L11/00; C08L1/10
Domestic Patent References:
| JP2003240955A | ||||
| JP2003279729A |
Attorney, Agent or Firm:
Norihiko Hibi
Einosuke Kishimoto
Akira Watanabe
Einosuke Kishimoto
Akira Watanabe