| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical film showing little increase in haze in a forced deterioration test that repeats high temperature and low temperature conditions. <P>SOLUTION: The method for manufacturing an optical film aims to manufacture an optical film containing cellulose acylate and a matting agent. A web containing cellulose acylate having a calcium content of 50 ppm or less and a polyester-based additive represented by a general formula (1): B-(G-A)n-G-B is stretched by 5% to 50% magnification of stretching at a temperature of 180°C or higher and 230°C or lower. Thereby, the optical film after stretched is controlled to have an in-plane retardation Re in the range from 0 to 10 nm and a retardation Rth in a thickness direction in the range from -5 to 20 nm, measured at a wavelength of 590 nm in an environment of 23°C and 55% RH. <P>COPYRIGHT: (C)2012,JPO&INPIT |
