Superabsorbent polymer and preparation method thereof

Patent metadata

Field	Value
Publication number	US-12262714-B2
Application number	US-202017774202-A
Country	US
Kind code	B2
Filing date	Nov 13, 2020
Priority date	Nov 13, 2019
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Provided are both a superabsorbent polymer capable of continuously and safely exhibiting an improved bacterial growth inhibitory property and a deodorant property without deterioration in the physical properties of the superabsorbent polymer, such as water retention capacity, absorption under pressure, etc., as well as a preparation method for the superabsorbent polymer.

First claim

The invention claimed is:

1. A superabsorbent polymer comprising:
a base polymer powder comprising a crosslinked polymer of water-soluble ethylene-based unsaturated monomers having acidic groups of which at least a part are neutralized, and a polymerizable antimicrobial monomer; and
a surface crosslinked layer formed on the base polymer powder, in which the crosslinked polymer is additionally crosslinked by a surface crosslinking agent;
wherein the polymerizable antimicrobial monomer comprises one or more of guanidine acrylate and salts thereof.

2. The superabsorbent polymer of claim 1 , wherein the guanidine acrylate is a compound represented by the following Chemical Formula 1:

in Chemical Formula 1,
R 11 and R 12 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms.

3. The superabsorbent polymer of claim 1 , wherein the salt of guanidine acrylate is a compound represented by the following Chemical Formula 2:

in Chemical Formula 2,
R 21 and R 22 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms.

4. The superabsorbent polymer of claim 1 , wherein the polymerizable antimicrobial monomer comprises one or more of compounds represented by the following Chemical Formulae:

5. The superabsorbent polymer of claim 1 , wherein the superabsorbent polymer has a 30-min centrifuge retention capacity of 29 g/g to 50 g/g for a physiological saline solution (0.9 wt % aqueous sodium chloride solution), as measured in accordance with EDANA method WSP 241.3, and exhibits antimicrobial property against Gram-negative bacteria.

6. The superabsorbent polymer of claim 5 , wherein the Gram-negative bacteria is Proteus mirabilis or E. coli.

7. A method of preparing the superabsorbent polymer of claim 1 , the method comprising:
carrying out a crosslinking polymerization of water-soluble ethylene-based unsaturated monomers having acidic groups of which at least a part are neutralized, and a polymerizable antimicrobial monomer, in the presence of an internal crosslinking agent, to form a hydrogel polymer;
drying, pulverizing, and classifying the hydrogel polymer to form a base polymer powder; and
carrying out additional crosslinking of the base polymer powder by heat treatment in the presence of a surface crosslinking agent,
wherein the polymerizable antimicrobial monomer comprises one or more of guanidine acrylate and salts thereof.

8. The method of claim 7 , wherein the polymerizable antimicrobial monomer comprises one or more of compounds represented by the following Chemical Formulae:

9. The method of claim 7 , wherein the polymerizable antimicrobial monomer is used in an amount of 0.01 part by weight to 10 parts by weight with respect to 100 parts by weight of the water-soluble ethylene-based unsaturated monomers.

10. The method of claim 7 , wherein the crosslinking polymerization is carried out by photopolymerization.

11. A hygiene product comprising the superabsorbent polymer of claim 1 , wherein the hygiene product is a diaper or sanitary pad.

Assignees

• Lg Chemical Ltd

Inventors

• Yun Haesung
• Choi Hyungsam
• Kim Dong Hyun
• Jung Seonjung
• Lee Ji Seok
• Lee Jin Woo
• Kim Jun Kyu
• Kim Byungguk
• Kim Sanggon

Classifications

• A61L2103/00

  Materials or objects being the target of disinfection or sterilisation · CPC title

• C08J2333/02

  Homopolymers or copolymers of acids; Metal or ammonium salts thereof · CPC title

• C08J3/245

  Differential crosslinking of one polymer with one crosslinking type, e.g. surface crosslinking · CPC title

• C08F220/06 Primary

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• A61L2300/404

  Biocides, antimicrobial agents, antiseptic agents · CPC title