METHOD OF CARBOXYMETHYLATION OF LIGNIN CARBOHYDRATE MATERIALS Russian patent published in 2012 - IPC C08B11/12 

FIELD: immunology and bioengineering.

SUBSTANCE: invention refers to the way of production of carboxymethyl esters of lignin carbohydrate materials in order to use them as chemical agent in the course of oil and gas well-sinking, in building industry, as chemical agents during flotation, in mining and processing industry. The lignin carbohydrate material is treated with the water solution containing 24.5 % of acetic acid, 6.5 % of hydrogen peroxide and 2 % of sulphuric acid at 100°C with the hydronic module (2-20) and is kept within 15-90 min. The treated solid product is rinsed with distilled water and undergoes alkaline treatment with the mole ratio of LCM OH-group:NaOH that equals 1:1 at the temperature of 60°C and within 120 min. Then natrium acetate monochloride is added with the mole ratio of LCM OH-group:CLCH₂COONa that equals 1:0.5 and is kept within 15-120 min. at the temperature of 25-80°C. The obtained product is washed with ethanol that is acidified with a mineral acid and is dried in the air.

EFFECT: product characterized by a high content of carboxymethyl groups and a high viscosity of solutions.

1 dwg, 4 tbl, 24 ex