	US 12,257,568 B2
	Superabsorbent polymer and preparation method for the same
Young Jae Hur, Daejeon (KR); Taebin Ahn, Daejeon (KR); Dong Hoon Park, Daejeon (KR); and Jihye Ryu, Daejeon (KR)
Assigned to LG Chem, Ltd., Seoul (KR)
Appl. No. 17/424,047
Filed by LG Chem, Ltd., Seoul (KR)
PCT Filed Sep. 16, 2020, PCT No. PCT/KR2020/012493 § 371(c)(1), (2) Date Jul. 19, 2021, PCT Pub. No. WO2021/054718, PCT Pub. Date Mar. 25, 2021.
Claims priority of application No. 10-2019-0114795 (KR), filed on Sep. 18, 2019; and application No. 10-2020-0118534 (KR), filed on Sep. 15, 2020.
Prior Publication US 2022/0080387 A1, Mar. 17, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. B01J 20/26 (2006.01); B01J 20/30 (2006.01); C08F 120/06 (2006.01); C08J 3/12 (2006.01); C08J 3/24 (2006.01)

CPC B01J 20/267 (2013.01) [B01J 20/3021 (2013.01); B01J 20/3085 (2013.01); C08F 120/06 (2013.01); C08J 3/12 (2013.01); C08J 3/245 (2013.01); C08F 2810/20 (2013.01); C08J 2333/02 (2013.01)]

13 Claims

1. A method of preparing a superabsorbent polymer comprising:

preparing a base resin in which an acrylic acid-based monomer having acidic groups which are at least partially neutralized and an internal crosslinking agent are crosslinked; and

heating the base resin in the presence of a surface crosslinking agent to carry out surface modification of the base resin,

wherein the internal crosslinking agent includes a first epoxy crosslinking agent having an epoxy equivalent weight of 100 g/eq or more to less than 130 g/eq, and a second epoxy crosslinking agent having an epoxy equivalent weight of 130 g/eq or more, and

wherein a weight ratio of first epoxy crosslinking agent: second epoxy crosslinking agent is 1.1:1 to 27:1; and

wherein the internal crosslinking agent consists of the first epoxy crosslinking agent and the second epoxy crosslinking agent.