Patent ID: 8519120

Claim:
A method for producing a low-substituted hydroxypropylcellulose powder having a molar substitution number per anhydrous glucose unit of 0.05 to 1.0, which is insoluble in water and swollenable by absorbing water, consisting essentially of the steps of: (1) adding an aqueous sodium hydroxide solution to powdered pulp in such a manner that weight ratio of sodium hydroxide with respect to anhydrous cellulose is 0.1 to 0.3 so as to obtain alkali cellulose; (2) etherifying the obtained alkali cellulose so as to obtain a crude reaction product; (3) neutralizing the sodium hydroxide contained in the obtained crude reaction product without performing a step of dissolving part or whole of the crude reaction product; (4) washing and dehydrating the resultant; (5) drying; and (6) pulverizing by compaction-grinding.