Cellulose material with improved absorbency
View Patent ↗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 2g/g.
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, and wherein the pre-superabsorbent polymer has functional groups attached thereto, where the functional groups of the pre-superabsorbent polymer upon heating will crosslink to convert the pre-superabsorbent polymer to a superabsorbent polymer;
(b) providing cellulose material;
(c) preparing a slurry comprising the aqueous solution of pre-superabsorbent polymer and cellulose material;
(d) filtering and heat treating the slurry to obtain a treated cellulose material having enhanced absorbency.
2. The method of claim 1 wherein 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, salt of carboxylic acid monomer, nitrogen containing vinylic monomer, and hydroxyl monomer.
4. The method of claim 1 wherein a network crosslinking agent is added to the aqueous solution of pre-superabsorbent polymer and the functional groups of the pre-superabsorbent polymer include hydroxyl and/or carboxyl groups.
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. 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 form 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.
9. The method of claim 8 wherein a network crosslinking agent is added to the aqueous solution of pre-superabsorbent polymer.
10. The method of claim 8 wherein the cellulose material of step (b) is pretreated with an aqueous alkali solution.
11. The method of claim 8 wherein the cellulose material is cellulose fiber.
12. The method of claim 8 wherein pre-superabsorbent is a water soluble polymer.
13. The method of claim 8 wherein the pre-superabsorbent polymer is formed from a monomer selected from the group consisting of carboxylic acid monomer, salt of carboxylic acid monomer, nitrogen containing vinylic monomer, and hydroxy monomer.
14. The method of claim 8 wherein the aqueous alkaline material is sodium hydroxide.