METHOD FOR PRODUCTION OF CELLULOSE HYDROXYALKYL ETHERS Russian patent published in 2003 - IPC

FIELD: cellulose derivatives. SUBSTANCE: cellulose is treated with 7-9% aqueous sodium hydroxide solution, resulting alkaline cellulose is ground and blown through with nitrogen. Removal of excess water from alkaline cellulose in amounts 10 to 80% of initial amount of water is performed in the hydroxyalkylation stage by dissolving water in hydroxyalkylation agent (propylene oxide or its mixture with ethylene oxide at weight ratio from 1: 0.05 to 1:0.10) added at once in amount 2 to 20 wt parts per 1 wt part cellulose. Neutralization is performed by treating product with aqueous solution of either acid alkali metal salt (with corresponding acid) in concentration 5-15%, or mixed acid plus neutral alkali metal salts in concentration 5-15%, or neutral alkali metal salt in concentration 5-15% at 50-90 C. In this stage, unreacted propylene oxide is distilled off. Invention can be applied in chemical, food, pharmaceutical, and other industries. EFFECT: increased technological appropriateness, reduced number of operations, hydroxyalkylation and washing times, reduced amount of by-products, and improved process safety. 2 cl, 1 tbl, 8 ex