Method for producing hydroxyalkyl alkyl cellulose

Abstract

There is provided a method for producing a hydroxyalkyl alkyl cellulose having a high storage modulus (thermal gel strength) and a small number of undissolved fibers. More specifically, there is provided a method for producing a hydroxyalkyl alkyl cellulose including steps of: bringing sheet-shaped pulp having a pore volume of 0.55 ml/g or more and less than 1.00 ml/g or chip-shaped pulp obtained by cutting the sheet-shaped pulp into contact with a first alkali metal hydroxide solution to obtain an alkali cellulose mixture, removing a liquid from the alkali cellulose mixture to obtain alkali cellulose, reacting the alkali cellulose with an alkylating agent and a hydroxyalkylating agent to obtain a first reaction mixture, mixing the first reaction mixture with a second alkali metal hydroxide solution to obtain a second reaction mixture, and purifying the second reaction mixture to obtain a hydroxyalkyl alkyl cellulose.

Dependencies are inferred from the claim text.