METHOD OF HYDROXYETHYLCELLULOSE PRODUCTION Russian patent published in 2023 - IPC C08B11/08 C08B11/20 C08B1/08 C08B15/00 

FIELD: hydroxyethyl cellulose production.

SUBSTANCE: method includes treatment with alkali, esterification, pH adjustment, washing and desalination, separation into solid and liquid phases of cellulose raw materials. Prior to washing and desalting, the method additionally includes the step of adding a precipitant until the hydroxyethyl cellulose precipitates. This method, after adjusting the pH value and before washing and desalination, may also further include the step of adding a crosslinking agent, which allows the crosslinking reaction with hydroxyethyl cellulose. The cellulose is treated with alkali and esterified in a solvent, and the solvent is removed before or after adjusting the pH value. The precipitant is added before the solvent is removed, and the solvent is removed by separation by centrifugation. Washing is carried out with water. The precipitant is a salt that is not mutually soluble with hydroxyethyl cellulose in water, the salt cation is one or more cations selected from sodium, iron, ammonium, magnesium, aluminum and zinc, and the salt anion is one or more anions, selected from the series including phosphate radical, sulfate radical, sulfite radical, carbonate radical and borate radical. Also, the substance is one or more compounds selected from the range including disodium phosphate and diammonium hydrogen phosphate.

EFFECT: more efficient and environmentally friendly method for producing hydroxyethyl cellulose.

11 cl, 3 tbl, 7 ex