MULTI-STEP CATALYTIC CARBOXYLATION OF MERCERISED CELLULOSE FIBRES Russian patent published in 2016 - IPC C08B15/04 D06M11/40 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical engineering of polymer fibres and multi-step catalytic carboxylation of mercerised cellulose fibres. Cellulose fibres have at least 12 meq/100 g of carboxyl substitution at the C-6 position of the anhydroglucose units, wherein cellulose includes at least 20% of cellulose II. Catalytic carboxylation of mercerised cellulose fibres is carried out in at least two catalytic carboxylation steps in a continuous sequence, where pH is controlled and at the beginning of each step a primary catalyst - oxoammonium salt or precursor thereof, and a secondary oxidant are added. Carboxylated mercerised cellulose can be obtained without aldehyde groups through a stabilisation step after the final carboxylation step, wherein aldehyde groups which are present in the fibres are converted to carboxyl groups.

EFFECT: invention provides a high level of carboxylation.

20 cl, 1 dwg, 3 tbl