Super absorbent polymer and preparation method thereof

Patent metadata

Field	Value
Publication number	US-10150829-B2
Application number	US-201514932570-A
Country	US
Kind code	B2
Filing date	Nov 4, 2015
Priority date	May 13, 2013
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

The present invention relates to a super absorbent polymer and a preparation method thereof, the super absorbent polymer including: surface cross-linked polymer particles prepared by surface cross-linking particles of a base resin, the base resin polymerized from a monomer composition including water-soluble ethylene-based unsaturated monomers having at least partially neutralized acidic groups; and a water-soluble component, wherein the water-soluble component has a weight average molecular weight of 150,000 to 300,000 g/mol. The super absorbent polymer may have high centrifuge retention capacity and excellent permeability at the same time, while having low content of the water-soluble component.

First claim

What is claimed is:

1. A super absorbent polymer, comprising:
surface cross-linked polymer particles prepared by surface cross-linking particles of a base resin, the base resin polymerized from a monomer composition including water-soluble ethylene-based unsaturated monomers having at least partially neutralized acidic groups; and
a water-soluble component,
wherein the water-soluble component has a weight average molecular weight of 150,000 to 250,000 g/mol,
wherein the water-soluble component has a content of 5 to 20 wt %, based on the total weight of the super absorbent polymer, as measured by the EDANA WSP 270.2 method; and
wherein a permeability of the super absorbent polymer measured according to the following Equation 1 is 10 to 150 seconds:
Permeability (sec)=T1−B  [Equation 1]

wherein T 1 represents a time required for decreasing a liquid level height from 40 ml up to 20 ml under a load of 0.3 psi (106.26 g) in a chromatography tube in the presence of saline solution-absorbed super absorbent polymer, wherein the saline solution-absorbed super absorbed polymer is prepared by putting 0.2±0.0005 g of a classified sample (30#to 50#) (particles size ranging from 300 μm to 600 μm) of super absorbent polymer into the chromatography tube and adding saline solution so that the saline solution has a volume of 50 ml, and leaving the tube for 30 minutes prior to measuring T 1 , and
B represents a time required for decreasing a liquid level height from 40 ml up to 20 ml in a chromatography tube filled with saline solution under a load of 0.3 psi in the absence of the super absorbent polymer;
wherein a centrifuge retention capacity is 30 to 35 g/g as measured by the EDANA WSP 241.2 method.

2. The super absorbent polymer of claim 1 , wherein an absorbency under load is 20 to 30 g/g as measured by the EDANA WSP 242.2 method.

3. A hygiene product including the super absorbent polymer of claim 1 .

4. A disposable diaper including the super absorbent polymer of claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Lee Sang Gi
• Ryu Chul Hee
• Kim Kyu Pal
• Kim Bhom Ri

Classifications

• B01J2220/68

  Superabsorbents · CPC title

• C08J2333/02

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

• A61L15/60

  Liquid-swellable gel-forming materials, e.g. super-absorbents · CPC title

• C08L101/14

  the macromolecular compounds being water soluble or water swellable, e.g. aqueous gels · CPC title

• B01J20/267

  Cross-linked polymers · CPC title