| 摘要 |
The purpose of the present invention is to provide an optical film which rarely tears during processing even when thin. The optical-film roll is a roll obtained by winding an optical film in the direction perpendicular to the film-width direction, the optical film comprising cellulose acetate and an additive and having a thickness of 20-50 µm. The optical film has an embossed part along each width-direction end and, when a 1-kg load is imposed on a circular area with a diameter of 5 mm of the surface of the embossed parts of the optical film and the optical film in this state is held at 23ºC and 55% RH for 10 minutes, then the percentage crush represented by the following equation is 30% or higher. In the equation, D is the height of the protrusions of the embossed parts as measured after the holding and D0 is the height of the protrusions of the embossed parts as measured before the load imposition. In the optical film, the content of residual methanol is 10-100 mass ppm of the optical film and is higher than each of the contents of residual ethanol and butanol therein. Percentage crush (%) = D/D0×100 |
