Patent ID: 8093376

Claim:
A process of preparing hydroxyethyl cellulose by reacting cellulose with ethylene oxide in the presence of alkali metal hydroxide, said process comprising: (a) preparing a mixture of cellulose and isopropyl alcohol azeotropic solvent in a horizontally agitated reactor equipped with a baffle in an upper portion of said reactor, (b) activating said cellulose by adding alkali metal hydroxide in the mixture, thereby preparing an activated mixture, (c) performing a first reaction by adding ethylene oxide and isopropyl alcohol azeotropic solvent in said activated mixture, thereby preparing a first reaction solution, (d) cooling said first reaction solution and controlling the amount of the alkali metal hydroxide remaining in said first reaction solution by adding isopropyl alcohol azeotropic solvent in said first reaction solution, (e) performing a second reaction by adding ethylene oxide in said first reaction solution, thereby preparing a second reaction solution, and (f) separating and filtering said second reaction solution, followed by its neutralization to pH 5-7 and drying.