US 9,809,930 B2
Papermaking agent system, method for making a papermaking agent system and its use
Asko Karppi, Turku (FI); Matti Hietaniemi, Espoo (FI); and Marco Polverari, Leonard (CA)
Assigned to Kemira OYJ, Helsinki (FI)
Appl. No. 14/442,433
Filed by Kemira Oyj, Helsinki (FI)
PCT Filed Nov. 13, 2013, PCT No. PCT/FI2013/051072
§ 371(c)(1), (2) Date May 13, 2015,
PCT Pub. No. WO2014/076372, PCT Pub. Date May 22, 2014.
Claims priority of application No. 20126189 (FI), filed on Nov. 13, 2012.
Prior Publication US 2016/0273166 A1, Sep. 22, 2016
Int. Cl. D21H 21/10 (2006.01); D21H 17/37 (2006.01); D21H 17/41 (2006.01); C08L 3/08 (2006.01); D21H 17/29 (2006.01); D21H 17/00 (2006.01); D21H 21/06 (2006.01); C08B 31/12 (2006.01); D21H 21/20 (2006.01)
CPC D21H 21/10 (2013.01) [C08B 31/125 (2013.01); C08L 3/08 (2013.01); D21H 17/29 (2013.01); D21H 17/375 (2013.01); D21H 17/72 (2013.01); D21H 21/06 (2013.01); D21H 21/20 (2013.01)] 15 Claims
 
1. Papermaking agent system in liquid form, which comprises
(i) cationic starch solution, prepared by cooking a starch mixture comprising a starch component and a water component, and
(ii) polymer composition, which has anionic and cationic groups and which has a cationic net charge of >0.1 meq/g, at pH 7, the polymer composition comprising, or originating from constituent c), where
constituent c) contains a third polymer, which comprises a copolymer comprising structural units derived from acrylamide and/or methacrylamide monomers, as well as hydrolytically unstable cationic groups attached to the copolymer, wherein the hydrolytically unstable cationic groups originate from monomers selected from the group consisting of 2-(dimethylamino)ethyl acrylate, [2-(acryloyloxy)ethyl] trimethylammonium chloride, 2-dimethylaminoethyl methacrylate and [2-(methacryloyloxy)ethyl] trimethylammonium chloride;
wherein constituent c) is added to one of the components of the starch mixture or to the starch mixture before the cooking of the starch mixture and a part of the hydrolytically unstable cationic groups are hydrolysed into anionic groups during the cooking; and
wherein the amount of hydrolysed groups is at least 4 mol-% of the total cationic groups in polymer.