Method for producing purified low-substituted hydroxypropyl cellulose

Abstract

Provided is a method for producing low-substituted hydroxypropyl cellulose with less yellowing. More specifically, the method for producing purified low-substituted hydroxypropyl cellulose includes the steps of: reacting alkali cellulose and an etherifying agent to obtain a reaction mixture; dispersing the reaction mixture in water containing a portion of acetic acid necessary for neutralizing the total amount of the reaction mixture to neutralize a portion of the reaction mixture, and then completely neutralizing with the remaining acetic acid to cause precipitation, to obtain a slurry containing crude low-substituted hydroxypropyl cellulose; disintegrating a solid component in the slurry through a cutter pump, the solid component containing the crude low-substituted hydroxypropyl cellulose, and discharging the slurry containing the disintegrated solid component; washing the discharged slurry with water to obtain a cake of purified low-substituted hydroxypropyl cellulose; and drying the cake.