Patent ID: 7815823
Filing Date: 2010-10-19
Classification: B29C,B29K,C09K,G02B

Abstract:
1. A method of manufacturing an optical film, comprising the step of: melt-casting a composition comprising a cellulose resin and a plasticizer to form the optical film, wherein the cellulose resin has a residual sulfuric acid content of 0.1-50 ppm in terms of sulfur element, and the composition contains a polymer having a weight average molecular weight of 500-30000 prepared via polymerization of ethylenic unsaturated monomers, or an acrylic polymer having a weight average molecular weight of 500-30000, the method further comprising the step of: conducting a stretching process for the optical film, wherein stretching temperature B in the stretching process is expressed in the following Formula (I): Formula (I): Melting temperature A—100° C.≦Stretching temperature B≦ Melting temperature A—40° C., where melting temperature A represents a temperature during melt-casting of the optical film.