Granted Patent B2

US 12,605,694 · App. 18/985,192 · Granted Apr 21, 2026

Inventors: Kyung Su Kim (Daejeon, KR); Kwang In Shin (Daejeon, KR); Soo Young Kwak (Daejeon, KR)

Assignee: LG Chem, Ltd.

B01J20/267B01J20/28004B01J20/28011B01J20/28016C08F220/06C08F2810/20

Abstract

Claims (25)

1 . A polyacrylic acid (salt)-based super absorbent polymer, the polyacrylic acid (salt)-based super absorbent polymer satisfying Equation 1,

( D Sap /D E )×100(%)≤92.5(%)  [Equation 1]

wherein, in Equation 1:

D Sap is a diffusion coefficient of ethanol in the polyacrylic acid (salt)-based super absorbent polymer measured by nuclear magnetic resonance (NMR) spectroscopy, and

D E is a diffusion coefficient of pure ethanol as measured by nuclear magnetic resonance spectroscopy;

wherein when the polyacrylic acid (salt)-based super absorbent polymer is swelled in water having an electrical conductivity value of 100 to 130 μS/cm for 1 minute, a maximum capacity of water that the polyacrylic acid (salt)-based super absorbent polymer is able to hold (free swelling capacity) is 170 g/g or more.

2 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer satisfies Equation 2:

80.0(%)≤( D Sap /D E )×100(%)  [Equation 2]

3 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the D Sap is 7.0 m 2 /s or more.

4 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the D Sap is 8.0 m 2 /s or less.

5 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has an average convexity value of 0.92 or less for all particles, as calculated using Equation 3:

M c =L s /L   [Equation 3]

wherein, in Equation 3,

M c is convexity,

L s is a length of a perimeter of a polygon of minimal perimeter that surrounds a two-dimensional (2D) image of a three-dimensional (3D) particle to be measured, and

L is an actual perimeter length of the 2D image of the 3D particle to be measured.

6 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has a centrifuge retention capacity (CRC) of 33 g/g or more, measured according to the EDANA method WSP 241.3.

7 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has an absorbency under pressure (AUP) of 28 g/g or more, measured under 0.3 psi according to the EDANA method WSP 242.3.

8 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has an average circle equivalent (CE) diameter of 220 μm to 400 μm.

9 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has an effective absorption capacity (EFFC) of 30 g/g or more, calculated by Equation 4:

EFFC=(CRC+AUP)/2  [Equation 4]

wherein, in Equation 4,

CRC is a centrifuge retention capacity (units: g/g) measured according to the EDANA method WSP 241.3, and

AUP is an absorbency under pressure (units: g/g) measured under 0.3 psi according to the EDANA method WSP 242.3.

10 . The polyacrylic acid (salt)-based super absorbent polymer of claim 1 , wherein the polyacrylic acid (salt)-based super absorbent polymer has an absorption rate (vortex time) of 40 seconds or less, measured by a vortex measurement method at 24.0° C.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (165)