CELLULOSIC ESTER RESIN MODIFIER, CELLULOSIC ESTER RESIN COMPOSITION, OPTICAL FILM, METHOD FOR PRODUCING POLARIZING-PLATE PROTECTIVE FILM, AND LIQUID CRYSTAL DISPLAY DEVICE

摘要

The purpose of the present invention is to provide a cellulosic ester resin modifier which is less likely to contaminate the production line when producing a cellulosic ester film, which facilitates obtaining a film that remains transparent even when exposed to high-humidity and high-temperature environments, and with which it is possible to obtain a film having excellent water vapor permeability resistance, and dimensional stability against heat. The present invention also provides a cellulosic ester resin composition using said modifier, a method for producing a polarizing-plate protective film, and a liquid crystal display device. Provided is a cellulosic ester resin modifier, characterized by containing a polyester polyol (A) having a phthalate residue and a C2-3 aliphatic glycol residue in a main chain thereof, and a diester (B) of a C2-3 aliphatic glycol and an aromatic monocarboxylic acid in a range where the mass ratio of (A)/(B) is 90/10 to 60/40.