US 12,031,274 B2
High cationic starch as a promoter in AKD sizing emulsions
Jennifer Riser, Atlanta, GA (US); Kirsi Terava, Kirkkonummi (FI); Timo Valkealaakso, Ruutana (FI); and Jaakko Hiltunen, Kauniainen (FI)
Assigned to Kemira Oyj, Helsinki (FI)
Filed by Kemira Oyj, Helsinki (FI)
Filed on Dec. 30, 2021, as Appl. No. 17/565,898.
Prior Publication US 2023/0212820 A1, Jul. 6, 2023
Int. Cl. D21H 17/29 (2006.01); D21H 17/00 (2006.01); D21H 17/66 (2006.01); D21H 23/10 (2006.01)
CPC D21H 17/29 (2013.01) [D21H 17/66 (2013.01); D21H 17/74 (2013.01); D21H 23/10 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for preparation of a starch-promoted alkyl ketene dimer (AKD) sizing emulsion for the manufacture of paper or board, wherein the method comprises adding to a stabilized AKD emulsion comprising a cationic starch stabilizing agent:
(a) a cationic starch sizing promoter, and
(b) polyaluminum chloride (PAC)
wherein addition of said cationic starch sizing promoter and PAC is effected
(i) at temperature ranging from 22-27° C.;
(ii) after emulsification, stabilization, and homogenization of said stabilized AKD emulsion comprising the cationic starch stabilizing agent; and
(iii) prior to addition of the starch-promoted AKD sizing emulsion to papermaking furnish, pulp, or fiber stock,
wherein the high-charge cationic starch sizing promoter comprises a percent nitrogen (% N) content ranging from 0.5% to 1.6% by mass.