RESIN WITH LARGE MOLECULAR WEIGHT GIVING PAPER TEMPORARY STRENGTH IN WET STATE Russian patent published in 2021 - IPC D21H17/34 D21H17/37 D21H17/44 D21H17/45 D21H17/47 D21H17/54 D21H17/55 D21H19/20 D21H19/24 D21H21/20 D21H23/04 D21H23/24 

FIELD: paper industry.

SUBSTANCE: present invention relates to a composition of glyoxalated copolymer capable of reacting with cellulose, used in paper products, as well as to a method for its preparation. The specified composition contains an aqueous medium and from 0.1 to 4 wt.% of glyoxalated copolymer of vinyl amide capable of reacting with cellulose per the total weight of the aqueous medium. Glyoxalated copolymer of vinyl amide is obtained by a reaction in an aqueous reaction medium of glyoxal and cationic copolymer of vinyl amide. A ratio of glyoxal:cationic copolymer per dry substance in the aqueous reaction medium is from 5 to 40 wt.% of glyoxal and from 95 to 60 wt.% of cationic copolymer of vinyl amide. The aqueous reaction medium has from 0.5 to 2.5 wt.% of the total concentration of solids. The average mass molecular weight of cationic copolymer of vinyl amide ranges from 20,500 to 46,100 Daltons. Cationic copolymer of vinyl amide includes from 5 to 95 wt.% of monomer of ammonium diallyl dimethyl halide and from 95 to 5 wt.% of acrylamide monomer per the total weight of cationic copolymer before glyoxalation.

EFFECT: resulting composition has improved characteristics for use in paper products, including the capability of giving strength in a wet state.

10 cl, 2 tbl, 5 ex