| 摘要 |
The purpose of the present invention is to provide an optical film which is not only capable of suppressing deterioration of a polarizer but also has high toughness even if the thickness thereof is small. An optical film according to the present invention contains a cellulose ester and one or more compounds (A) selected from the group consisting of a polymer containing a repeating unit that is derived from a monomer represented by general formula (1), a compound represented by general formula (2), a compound represented by general formula (3) and a compound represented by general formula (4). This optical film has a thickness of 15-45 μm. If the optical film is elongated in the long side direction (α) or in the short side direction (β) of the optical film at 23°C at 55% RH, and if T (MPa or N/mm2) is the stress at break, E (%) is the elongation at break and A (mm2) is the cross-sectional area of the optical film in a direction perpendicular to the elongation direction, the toughness G represented by the formula below is 7-20 in the long side direction (α) and in the short side direction (β). |
