METHOD FOR PRODUCING LOW-SUBSTITUTED HYDROXYPROPYLCELLULOSE

摘要

PURPOSE: A manufacturing method of low-substituted hydroxy propylcellulose is provided to stably and quickly low-substituted hydroxy propylcellulose with wanted viscosity by depolymerization avoiding the danger of explosion. CONSTITUTION: A manufacturing method of low-substituted hydroxy propylcellulose comprises following steps: reacting alkali cellulose and an etherifying agent; and depolymerizing after the reaction. The manufactured low-substituted hydroxy propylcellulose has the degree of propoxy substitution of 9.5-16.0weight%. The alkali cellulose is obtained by contacting pulp and alkali metal oxide solution. The depolymerization is conducted by controlling the concentration of oxygen in a reactor.