METHOD FOR PREPARING CELLULOSE ESTER SOLUTION, METHOD FOR PRODUCING CELLULOSE ESTER FILM, CELLULOSE ESTER FILM AND POLARIZING PLATE USING THE FILM

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a cellulose ester film having a reduced retardation value (Rt value) in the thickness direction by preparing a cellulose ester solution without using a chlorine-based solvent. ;SOLUTION: This method for preparing a cellulose ester solution is characterized in that a mixture containing a cellulose ester and bromopropane is dissolved in the whole organic solvents used at a temperature equal to or higher than the boiling point of an organic solvent having the lowest boiling point under normal pressure among the whole organic solvents used and under a pressure condition not to cause bubbling.;COPYRIGHT: (C)2001,JPO