POLYANIONIC CELLULOSE PRODUCTION PROCESS Russian patent published in 2006 - IPC C08B11/12 

FIELD: cellulose derivatives production.

SUBSTANCE: invention relates to production of high-molecular weight substances, in particular carboxymethylcellulose sodium salt with high substitution degrees, which is characterized by uniform distribution of carboxyl groups, that is polyanionic cellulose applicable as thickener and emulsifier in papermaking, textile, and oil and gas producing industries. Process is accomplished through activation of cellulose followed by feeding the same on twin-screw multizone reactor-mixing machine, addition of sodium hydroxide in the form of aqueous solution in amount 0.9-1.2 mole per 1 mole cellulose and sodium monochloroacetate, and finally intensive stirring of resulting product in one or several in series arranged reactor-mixing machines while additionally introducing sodium hydroxide in the form of aqueous solution in amount 0.4-0.6 mole per 1 mole cellulose all in one time or in equal portions. Transfer of into next reactor-mixing machine is accomplished with the aid of transportation means.

EFFECT: increased resistance of aqueous solutions of polyanionic cellulose to polymineral aggression and their biological resistance.

6 cl, 1 tbl