Patent ID: 7323530

Claim:
A method of manufacturing a transparent resin film, the method comprising the steps of: dissolving an alkoxysilane in a first solvent containing a alcohol having 1 to 4 carbon atoms to obtain an alkoxysilane polycondensation product solution; dissolving cellulose ester in a second mixture solvent of methylene chloride and ethyl alcohol having a methylene chloride to ethyl alcohol ratio of from 95:5 to 80:20 to obtain a cellulose ester solution; mixing the alkoxysilane polycondensation product solution and the cellulose ester solution to provide a cellulose ester dope containing the alcohol in an amount of 1 to 40% by weight; and casting the resulting cellulose ester dope on a support to form the transparent resin film, wherein the alkoxysilane is represented by the following formula 1: (R 4-n )Si(OR′) n Formula 1 wherein R and R′ independently represent a hydrogen atom or a substituent; and n represents an interger of 3 or 4, and wherein the transparent resin film has an ultraviolet light transmittance of not less than 50%, the ultaviolet light having a wavelength range of from 250 to 450 nm, and has a glass transition temperature of not less than 180° C., the glass transition temperature being measured according to thermal stress strain measurement (TMA).