Preparation method for super absorbent polymer film

Patent metadata

Field	Value
Publication number	US-12590193-B2
Application number	US-202117797004-A
Country	US
Kind code	B2
Filing date	Mar 23, 2021
Priority date	Mar 23, 2020
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

The present disclosure relates to a preparation method for a super absorbent polymer film. Specifically, it relates to a preparation method for a new type of super absorbent polymer film, which is thin and exhibits excellent absorption performance. In addition, the super absorbent polymer film of the present disclosure has excellent flexibility and excellent mechanical properties, is free from scattering or leaking, and does not require an auxiliary substance such as pulp, so that products can be made thinner and the manufacturing process and costs may be reduced.

First claim

The invention claimed is:

1 . A method for preparing a super absorbent polymer film, comprising the steps of:
preparing a monomer composition by mixing an acrylic acid-based monomer having at least partially neutralized acidic groups, a cellulose-based thickener, a moisturizing agent, a polymerization initiator, and a solvent; casting the monomer composition on a substrate to form a monomer composition film; forming a hydrogel polymer film by irradiating heat and/or light while drawing the monomer composition film; and drying the hydrogel polymer film.

2 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the monomer composition further contains an internal cross-linking agent.

3 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the cellulose-based thickener is at least one selected from the group consisting of nanocellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, and sodium carboxymethylcellulose.

4 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the moisturizing agent is at least one selected from the group consisting of glycerin; diglycerin; ethylene glycol; propylene glycol; butylene glycol; sorbitol; polyethylene glycol; polyglycerin-3; polyglycerin-6; polyglycerin-10; an ester compound of polyglycerin-10 and a C3 to C18 saturated fatty acid; citric acid; triethyl citrate; methyl citrate; sodium citrate; and trisodium 2-methylcitrate.

5 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the cellulose-based thickener is contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the solid content in the monomer composition.

6 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the moisturizing agent is contained in an amount of 5 to 70 parts by weight based on 100 parts by weight of the acrylic acid-based monomer.

7 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the monomer composition further contains a polyether-modified siloxane-based surfactant having a polyethylene oxide group and/or a polypropylene oxide group.

8 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the monomer composition further contains at least one foaming agent selected from the group consisting of expandable microsphere, expanded microsphere, an azo compound, and an inorganic foaming agent.

9 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the monomer composition has a viscosity at 25° C. of 100 mPa·s or more.

10 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the monomer composition film has a moisture content of 30 wt % to 60 wt %.

11 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein tension applied to the monomer composition film in the step of forming the hydrogel polymer film is 40 to 100 N/m.

12 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the step of forming the hydrogel polymer film is performed at a temperature of 40 to 90° C., and the drying step is performed at a temperature of 80 to 150° C.

13 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the super absorbent polymer film obtained after the drying step has a moisture content of 15% or less.

14 . The method for preparing a super absorbent polymer film of claim 1 ,
after the drying step, further comprising the steps of: applying a surface cross-linking solution containing a surface cross-linking agent to a surface of the super absorbent polymer film; and performing surface modification by heating the super absorbent polymer film coated with the surface cross-linking solution.

15 . The method for preparing a super absorbent polymer film of claim 14 ,
wherein an amount of the surface cross-linking agent applied to the surface of the super absorbent polymer film is 0.05 g/m 2 to 2.0 g/m 2 .

16 . The method for preparing a super absorbent polymer film of claim 2 ,
wherein the internal cross-linking agent is contained in a concentration of 10 ppm to 3000 ppm with respect to the monomer composition.

17 . The method for preparing a super absorbent polymer film of claim 7 ,
wherein the polyether-modified siloxane-based surfactant is contained in an amount of 0.05 to 0.5 parts by weight based on 100 parts by weight of the monomer composition.

18 . The method for preparing a super absorbent polymer film of claim 8 ,
wherein the foaming agent is contained in an amount of 0.1 to 10 parts by weight, based on 100 parts by weight of the monomer composition.

19 . The method for preparing a super absorbent polymer film of claim 14 ,
wherein the surface cross-linking agent is contained in an amount of 0.1 wt % to 1.5 wt % based on 100 wt % of the surface cross-linking solution.

20 . The method for preparing a super absorbent polymer film of claim 1 ,
wherein the super absorbent polymer film prepared has a thickness of 0.001 to 0.8 mm, and the pore size of about 10 to 500 μm.

Assignees

• Lg Chemical Ltd

Inventors

• Yoon Kiyoul
• Kang Seongkyun
• Kim Yu Jin
• Kim Gicheul
• Joo Hyosook
• Choi Hyeon
• Park Se Yeol

Classifications

• C08J2333/02

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

• C08J3/242

  Applying crosslinking or accelerating agent onto compounding ingredients such as fillers, reinforcements · CPC title

• C08J3/075

  Macromolecular gels · CPC title

• C08F20/06

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

• C08F2/50

  with sensitising agents · CPC title