To provide a method for obtaining a broad optical film including a birefringent layer excellent in accuracy of an orientation axis.
An optical film including a birefringent layer having a slow axis in a TD direction is obtained by the production method of an optical film of the present invention. The method includes: a coating film forming step of applying a birefringent layer forming material on a shrinkable film 1 that can shrink in a MD direction so as to form a coating film 3 on the shrinkable film 1, the birefringent layer forming material containing a non-liquid crystalline material giving a birefringent index Δnxz in a thickness direction, which is represented by a formula Δnxz=nx'-nz', of 0.0007 or more; and a birefringent layer forming step of forming a birefringent layer by shrinking the shrinkable film 1 in the MD direction as well as broadening the film in the TD direction.
OSUGA KOYA
YAGINUMA HIRONORI
MURAKAMI NAHO
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Nobuo Ouchi
Suzuki Katsuto