Manufacturing method for cellulose ether having high degree of substitution

Abstract

A manufacturing method for cellulose ether having a high degree of substitution characterized in that an etherifying agent represented by a general formula RCH.sub.2 X (where R is aromatic group, heterocyclic group, vinyl group or ethynyl group or the same group substituted and X is chlorine or bromine) is reacted with a uniform solution of cellulose acetate having a degree of substitution of 2.0 and over in an organic solvent in the presence of a base to manufacture a highly substituted cellulose ether having a degree of substitution of 2.0 and over per anhydrous glucose unit by a one stage reaction at a good yield. As a general method for manufacturing cellulose ether, a method for reacting an etherifying agent with alkali cellulose is now in use. For the general method, several improved methods have been proposed. However, it is difficult to manufacture cellulose ether having a degree of substitution of 2.5 and over by a one stage reaction using the general method. As manufacturing methods for cellulose ether other than the general method, a method for using a solvent-soluble cellulose derivative as the raw material and a method for using a special solvent in which cellulose is soluble were proposed. However, the former had a defect of a low yield and the latter had a defect of too long a reaction time.

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