HIGH MOLECULAR WEIGHT AND HIGH CATIONIC CHARGE GLYOXALATED POLYACRYLAMIDE COPOLYMERS AND METHODS FOR PRODUCTION AND USE THEREOF Russian patent published in 2018 - IPC D21H17/55 D21H17/49 

FIELD: chemistry.

SUBSTANCE: invention relates to a cellulose reactive glyoxalated copolymer composition and methods of producing and using the glyoxalated copolymer composition to, for instance, strengthen paper or board. Composition includes an aqueous medium containing a glyoxalated copolymer, wherein the glyoxalated copolymer is obtained by reaction in an aqueous reaction medium of a dry weight ratio of glyoxal : cationic copolymer in the range from 5 (±5 %) to 40 (±5 %) of glyoxal to 95 (±5 %) to 60 (±5 %) of the cationic copolymer. Cationic copolymer has a weight average molecular weight of 120,000 (±5 %) to 1 (±5 %) million daltons, based on the total weight of the cationic copolymer before glyoxalation. In addition, the ratio of the weight-average molecular weight of the cationic copolymer before glyoxalation to weight percent of the diallyldimethylammonium halide monomer constituting the cationic copolymer before glyoxalation is greater than or equal to 4,000 or 4,000 to 40,000 daltons/wt%.

EFFECT: technical result is high dewatering rate of the treated cellulosic suspension, as well as the dry strength of the paper / paperboard obtained from the suspension.

33 cl, 4 dwg, 6 tbl, 2 ex