US 12,410,286 B2
Method for preparation of super absorbent polymer
Junwye Lee, Daejeon (KR); Tae Young Won, Daejeon (KR); Jungmin Sohn, Daejeon (KR); Hyemin Lee, Daejeon (KR); Kwangin Shin, Daejeon (KR); Minsu Kim, Daejeon (KR); and Chang Hun Han, Daejeon (KR)
Assigned to LG Chem, Ltd., Seoul (KR)
Appl. No. 17/598,609
Filed by LG Chem, Ltd., Seoul (KR)
PCT Filed Sep. 8, 2020, PCT No. PCT/KR2020/012102
§ 371(c)(1), (2) Date Sep. 27, 2021,
PCT Pub. No. WO2021/066340, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 10-2019-0121050 (KR), filed on Sep. 30, 2019; and application No. 10-2020-0113937 (KR), filed on Sep. 7, 2020.
Prior Publication US 2022/0145018 A1, May 12, 2022
Int. Cl. C08J 3/24 (2006.01); C08F 20/06 (2006.01); C08J 3/12 (2006.01)
CPC C08J 3/24 (2013.01) [C08F 20/06 (2013.01); C08J 3/12 (2013.01); C08J 2333/08 (2013.01)] 5 Claims
 
1. A method for preparation of a super absorbent polymer, comprising:
1) Forming a hydrogel polymer containing a first cross-linked polymer by cross-linking polymerization of a water-soluble ethylene-based unsaturated monomer having at least partially neutralized acidic groups in the presence of an internal cross-linking agent;
2) Drying, pulverizing and classifying the hydrogel polymer to form a base resin powder; and
3) cross-linking a surface by heat-treating the base resin powder in the presence of a surface cross-linking solution to form super absorbent polymer particles; and
4) Adding brine to the super absorbent polymer particles to remove fine particles having a particle diameter of 150 μm or less present in the super absorbent polymer,
wherein a conductivity of the brine is 15 to 55 mS/cm,
wherein the brine is an aqueous solution of Na2CO3, NaCl, or Mg(CH3COO)2,
wherein an amount of the brine is 0.1 to 10 wt % based on the super absorbent polymer particles,
wherein about 50% or more of the fine particles contained in the super absorbent polymer are removed.