Title:
PRODUCTION OF HYDROXYPROPYLCELLULOSE HAVING LOW DEGREE OF SUBSTITUTION
Document Type and Number:
Japanese Patent JP3212532
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain the subject cellulose capable of increasing the granulation speed of a granular preparation by an extruding granulation method even in the case of adding the same in a large amount by controlling the amount of washing liquid for a crude hydroxypropylcellulose having a low degree of substitution obtained by reacting an alkali cellulose with propyleneoxide to leave a specific amount of propylene glycols as a reaction byproduct.
SOLUTION: This method for producing a hydroxypropylcellulose having a low degree of substitution comprises reacting an alkalicellulose containing sodium hydroxide with propyleneoxide, then dispersing the reaction mixture into a water containing 5-40 mol% acid (e.g.; acetic acid) required for neutralizing the all of sodium hydroxide to dissolve a part of the cellulose ether, and then adding the acid to neutralize the residual sodium hydroxide to obtain a crude hydroxypropylcellulose having a low degree of substitution. The obtained cellulose ether is washed with 30-80 fold weight hot water (usually, at ≥60°C temperature) to make 0.03-2 wt.% content of propylene glycols produced as a byproduct in the reaction of the cellulose ether formation and ≤1 wt.% ignition residue to obtain the objective cellulose.
Inventors:
Yasuaki Mutoh
Sakae Ohara
Sakae Ohara
Application Number:
JP7287497A
Publication Date:
September 25, 2001
Filing Date:
March 26, 1997
Export Citation:
Assignee:
Shin-Etsu Chemical Co., Ltd.
International Classes:
A61K9/16; C08B11/08; (IPC1-7): C08B11/08
Attorney, Agent or Firm:
Nao Okuyama (2 outside)