Optical film, polarizing plate and display device utilizing the film, and production method of optical film

Abstract

An optical film obtained by a process comprising the steps of: (a) casting a dope comprising a cellulose ester and a non-chlorinated solvent on a metal support, the cellulose ester having a total acyl substitution degree of 2.6 to 2.85 and having a ratio of a weight-average molecular weight to a number-average molecular weight of 1:1 to 3:1; (b) drying the cast dope on the metal support so as to obtain a cellulose ester film; (c) pealing the cellulose ester film from the metal support; (d) further drying the cellulose ester film while providing a longitudinal stretch or a lateral stretch to the cellulose ester film; and (e) providing a metal oxide layer on the cellulose ester film.

Dependencies are inferred from the claim text.