METHOD OF SULPHATION ORGANOSOLVENT LIGNIN Russian patent published in 2018 - IPC C07G1/00 C08H7/00 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical technology and is intended for preparation of water-soluble ammonium or sodium salts of lignin sulphate esters, which can be used as chemical additives to regulate the properties of washing liquids when drilling oil and gas wells, and in the pharmaceutical industry as potential antiviral drugs. Method of sulphation of organosolvent lignins is carried out by the interaction of lignins with the sulfating complex sulfamic acid – urea in the presence of a solvent of N,N-dimethylformamide with stirring and a temperature of 100 °C for 0.5–6.0 hours at a ratio of the amount of lignin to the sulfating complex of 1:3 (pmol). Product is isolated by neutralization and decantation of the solvent, then purified from low molecular weight impurities by dialysis.

EFFECT: yield of sulfated lignin is increased, the range of solvents for sulphating lignins in a homogeneous medium is extended.

1 cl, 1 tbl, 7 ex