US 11,931,720 B2
Superabsorbent polymer composition and method for preparing the same
Young Jae Hur, Daejeon (KR); Dae Woo Nam, Daejeon (KR); Bohee Park, Daejeon (KR); and Seongbeom Heo, Daejeon (KR)
Assigned to LG Chem, Ltd., Seoul (KR)
Appl. No. 16/768,981
Filed by LG Chem, Ltd., Seoul (KR)
PCT Filed Nov. 28, 2018, PCT No. PCT/KR2018/014840
§ 371(c)(1), (2) Date Jun. 2, 2020,
PCT Pub. No. WO2019/117511, PCT Pub. Date Jun. 20, 2019.
Claims priority of application No. 10-2017-0169492 (KR), filed on Dec. 11, 2017; and application No. 10-2018-0148009 (KR), filed on Nov. 27, 2018.
Prior Publication US 2021/0113989 A1, Apr. 22, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. B01J 20/26 (2006.01); B01J 20/24 (2006.01); B01J 20/28 (2006.01); B01J 20/30 (2006.01); B01J 20/34 (2006.01); C08F 220/06 (2006.01); C08J 3/24 (2006.01)
CPC B01J 20/267 (2013.01) [B01J 20/28021 (2013.01); B01J 20/3021 (2013.01); B01J 20/3085 (2013.01); C08F 220/06 (2013.01); C08J 3/245 (2013.01); C08F 2810/20 (2013.01)] 7 Claims
 
1. A method for preparing superabsorbent polymer comprising:
preparing a base resin in which acrylic acid-based monomers having acid groups, of which at least a part are neutralized, and an internal crosslinking agent are crosslinked;
mixing hydrophobic material having a HLB of 0 or more and 6 or less, and an epoxy-based surface crosslinking agent with the base resin to prepare a mixture; and
increasing a temperature of the mixture to conduct surface modification of the base resin,
wherein the hydrophobic material is mixed in a content of 0.02 to 0.5 parts by weight, based on 100 parts by weight of the base resin,
wherein the hydrophobic material includes one or more of glyceryl stearate, glycol stearate, glyceryl laurate, sorbitan stearate, sorbitan trioleate, or PEG-4 dilaurate, and
wherein during the mixing, the hydrophobic material is dry mixed with the base resin, and then, the epoxy-based surface crosslinking agent is dissolved in water and mixed in a state of a surface crosslinking solution.