Cellulose material with improved absorbency

• US 20050020771A1
• Filed: 08/20/2004
• Published: 01/27/2005
• Est. Priority Date: 09/17/2001
• Status: Active Grant

• Current Assignee: Evonik Superabsorber GmbH
• Original Assignee: Evonik Stockhausen GmbH (Evonik Degussa GmbH)
• Inventors: Smith, Scott J., Ahmed, Iqbal, Jones, Angela Marie
• Granted Patent: US 7,482,058 B2
• Time in Patent Office: Days
• US Class Current: 525/54.300
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 2013/530481 having superabsorbent materials, i.e. highly absorbent polymer gel materials
• CPC Class Codes: A61L 15/28 Polysaccharides or their derivatives A61L15/225 takes precedence
• CPC Class Codes: C08B 15/00 Preparation of other cellulose derivatives or modified cellulose , e.g. complexes
• CPC Class Codes: C08L 1/00 Compositions of cellulose, modified cellulose or cellulose derivatives
• CPC Class Codes: C08L 1/08 Cellulose derivatives
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof

Abstract

An absorbent cellulose material having an application of superabsorbent polymer adhered to the cellulose material. In particular, the cellulose material has an application of pre-superabsorbent polymer adhered to the material, wherein an aqueous solution of pre-superabsorbent polymer is applied to the cellulose material and converted to superabsorbent polymer upon subjected to heat for a sufficient time. The absorbent cellulose material has a fluid retention of greater then 2 g/g.

Claims

1. A method for making a treated cellulose material having enhanced absorbency, said method comprising:

(a) preparing an aqueous solution of pre-superabsorbent polymer, which is formed from at least one monomer, where the pre-superabsorbent polymer is capable upon being subjected to heating of becoming a superabsorbent polymer;

(b) providing cellulose material;

(c) preparing a slurry comprising the aqueous solution of pre-superabsorbent polymer and the cellulose material,

(d) filtering and heat treating the slurry to obtain a treated cellulose material having an enhanced absorbency.

2. The method of claim 1 where in pre-superabsorbent is a water soluble polymer.

3. The method of claim 1 wherein the pre-superabsorbent polymer is formed from a monomer selected from the group consisting of carboxylic acid monomer, salts of carboxylic acid monomer, nitrogen containing vinylic monomer, and hydroxy monomer.

4. The method of claim 1 wherein a network crosslinking agent is added to the aqueous solution of pre-superabsorbent polymer.

5. The method of claim 1 wherein the crosslinking agent is diglycidyl ether.

6. The method of claim 1 wherein the cellulose material of step (b) is pretreated with an aqueous alkali solution.

7. The method of claim 1 wherein the cellulose material is cellulose fiber.

8. An absorbent cellulose material comprising a cellulose material having an application of superabsorbent polymer composition adhered to the cellulose material wherein an aqueous solution of pre-superabsorbent polymer is applied to the cellulose material and converted to absorbent polymer upon subjected to heat for a sufficient time wherein the absorbent cellulose material has a fluid retention of greater than 2 g/g.

9. A method for making a treated cellulose material having enhanced absorbency, said method comprising

(a) preparing an aqueous solution of pre-superabsorbent polymer, which is formed from at least one monomer, where the pre-superabsorbent polymer is capable upon being subjected to heating of becoming a superabsorbent polymer;

(b) providing cellulose material;

(c) providing superabsorbent polymer fines;

(d) preparing a slurry comprising the aqueous solution of pre-superabsorbent polymer, the superabsorbent polymer fines, and the cellulose material; and

(e) filtering and heat treating the cellulose material to convert the aqueous solution of pre-superabsorbent and superabsorbent polymer fines into a superabsorbent polymer resulting in a treated cellulose material having enhanced absorbency.

10. The method of claim 9 wherein a network crosslinking agent is added to the aqueous solution of pre-superabsorbent polymer.

11. The method of claim 9 wherein the cellulose material of step (b) is pretreated with an aqueous alkali solution.

12. The method of claim 9 wherein the cellulose material is cellulose fiber.

13. The method of claim 9 wherein pre-superabsorbent is a water soluble polymer.

14. The method of claim 9 wherein the pre-superabsorbent polymer is formed from a monomer selected from the group consisting of carboxylic acid monomer, salts of carboxylic acid monomer, nitrogen containing vinylic monomer, and hydroxy monomer.

15. The method of claim 9 wherein the aqueous alkaline material is sodium hydroxide.

16. An absorbent cellulose material comprising a cellulose material having an application of pre-superabsorbent polymer and superabsorbent polymer fines adhered to the material, wherein an aqueous solution of pre-superabsorbent polymer is applied to the cellulose material and converted to superabsorbent polymer upon subjected to heat for a sufficient time wherein the cellulose material has a fluid retention of greater then 2 g/g.

17. A method for making pulp or paper comprising the steps of:

(a) preparing an aqueous solution of pre-superabsorbent polymer, which is formed from at least one monomer, where the pre-superabsorbent polymer is capable upon being subjected to heating of becoming a superabsorbent polymer;

(b) providing cellulose material;

(c) preparing a slurry comprising the aqueous solution of pre-superabsorbent polymer and the cellulose material; and

(d) filtering and heat treating the slurry to obtain a treated cellulose material having an enhanced absorbency.

18. The method of claim 17 wherein pre-superabsorbent is a water soluble polymer.

19. The method of claim 17 wherein the pre-superabsorbent polymer is formed from a monomer selected from the group consisting of carboxylic acid monomer, salts of carboxylic acid monomer, nitrogen containing vinylic monomer, and hydroxy monomer.

20. The method of claim 17 wherein a network crosslinking agent is added to the aqueous solution of pre-superabsorbent polymer.

21. The method of claim 17 wherein the cellulose material of step (b) is pretreated with an aqueous solution.

22. The method of claim 17 wherein the cellulose material is cellulose fiber.

23. The method of claim 17 including providing superabsorbent fines to the preparation of the slurry.

24. An absorbent product selected from the group consisting of, agricultural products, fiber optic cables, power cables, water blocking tapes, insulation, hygiene articles, feminine care products, sanitary napkins, tampons, adult incontinence items, baby diapers, paper towels, sealing composites for concrete blocks, bandages, surgical sponges, meat trays, and bath mats, the absorbent product comprising an absorbent cellulose material comprising a cellulose material having an application of superabsorbent polymer composition adhered to the cellulose material wherein an aqueous solution of pre-superabsorbent polymer is applied to the cellulose material and converted to absorbent polymer upon subjected to heat for a sufficient time wherein the absorbent cellulose material has a fluid retention of greater than 2 g/g.