Claims
- 1. A hydrogel-forming polymeric material comprising a first compound which is a superabsorbent polymer and a second compound present in the first as a dispersed phase comprising an elastomeric material effective to increase the fracture resistance of the superabsorbent prepared from:a. a first compound comprising carboxylic-functional polyelectrolytes in combination with a crosslinker reactive with carboxyl or carboxylate groups; and b. an effective amount of a second compound comprising an aqueous dispersion of a rubbery material, wherein the hydrogel-forming polymeric material exhibits a gel capacity of at least about 20 grams 0.9% saline per gram of material and a Friability Index of at least about 25% greater than the Friability Index exhibited by a hydrogel-forming polymeric material that is prepared without the second compound.
- 2. The hydrogel-forming polymeric material of claim 1 wherein the first compound is selected from the group consisting of poly(acrylic acid), poly(methacrylic acid), poly(isobutylene-alt-maleic anhydride), poly(styrene-alt-maleic anhydride, carboxymethyl cellulose or starch, and mixtures and copolymers thereof which has been crosslinked by reaction with a crosslinkers reactive with carboxyl or carboxylate groups.
- 3. The hydrogel-forming polymeric material of claim 1 wherein the second compound is a latex prepared by polymerizing ethylenically unsaturated monomers selected from the group consisting of alkylacrylates and methacrylates, styrene, butadiene, isoprene, acrylonitrile, vinyl acetate, and ethylene, and copolymers thereof.
- 4. The hydrogel-forming polymeric material of claim 3 wherein the minimum film-forming temperature of the second compound is not greater than about 25° C. such that the second compound is elastomeric at room temperature.
- 5. The hydrogel-forming polymeric material of claim 1 wherein the second compound is a natural rubber latex.
- 6. The hydrogel-forming polymeric material of claim 1 wherein the second compound is used in an amount that is greater than 0 to about 100 weight percent of the first compound used.
- 7. The hydrogel-forming polymeric material of claim 1 wherein the second compound is used in an amount that is greater than 0 to about 25 weight percent of the first compound used.
- 8. A hydrogel-forming polymeric material comprising a first compound which is a superabsorbent polymer and a second compound present in the first as a dispersed phase comprising an elastomeric material effective to increase the fracture resistance of the superabsorbent prepared from the steps of:(i) preparing an aqueous solution of carboxylic-functional ethylenically unsaturated monomers and a suitable polyfunctional crosslinking agent, said crosslinking agent being reactive with the carboxyl or carboxylate groups or reactive in radical-induced copolymerization with the monomer solution; (ii) blending an amount of an aqueous colloidal dispersion of a rubbery polymeric material into the aqueous solution obtained in step (i), said amount being effective to increase the fracture resistance of the water swellable hydrogel-forming polymeric material; and (iii) initiating the polymerization of the aforementioned monomer/rubber blend.
- 9. The hydrogel-forming polymeric material of claim 8 wherein the first compound is a polymer or copolymer prepared from monomers selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and its anhydride, the salts of the foregoing acidic monomers, and any ethylenically unsaturated monomer copolymerizable with the foregoing monomers, and a poly-functional comonomer capable of crosslinking the foregoing polymers and copolymers during the polymerization step.
- 10. A disposable absorbent product comprising a liquid-permeable topsheet, a backsheet attached to the topsheet, and an absorbent structure positioned between the topsheet and the backsheet, wherein the absorbent structure comprises a hydrogel-forming polymeric material prepared from:a. a first compound which is a superabsorbent polymer; and b. a second compound present in the first as a dispersed phase comprising a elastomeric material effective to increase the fracture resistance of the superabsorbent wherein the hydrogel-forming polymeric material exhibits a gel capacity of at least about 20 grams 0.9% saline per gram of material and a Friability Index of at least about 25% greater than the Friability Index exhibited by hydrogel-forming polymeric material that is prepared without the second compound.
- 11. The process of claim 10 in which the aqueous dispersion of rubbery material is a natural rubber latex.
- 12. The process of claim 10 in which the aqueous dispersion of rubbery material is a synthetic latex prepared from ethylenically unsaturated monomers selected from the group comprising: alkylacrylates and methacrylates, styrene, butadiene, isoprene, acrylonitrile, vinyl acetate, and ethylene and copolymers thereof.
- 13. The process of claim 10 in which the aqueous dispersion of rubbery material is a natural rubber latex.
- 14. The process of claim 10 in which the aqueous dispersion of rubbery material is a synthetic latex prepared from ethylenically unsaturated monomers selected from the group comprising: alkylacrylates and methacrylates, styrene, butadiene, isoprene, acrylonitrile, vinyl acetate, and ethylene and copolymers thereof.
- 15. A process for preparing a hydrogel-forming polymeric material comprising preparing a carboxylic-functional polyelectrolyte solution bya. blending a crosslinker reactive with carboxyl or carboxylate groups into the polyelectrolyte solution along with an aqueous colloidal dispersion of a rubbery polymeric material; b. drying and sizing the hydrogel-forming polymeric material wherein the particle size distribution is between 75 and 1000 microns and is useful as the superabsorbent additive to absorbent hygienic products.
- 16. A process for preparing a hydrogel-forming material comprising the steps of:(i) preparing an aqueous solution of carboxylic-functional ethylenically unsaturated monomers and a suitable polyfunctional crosslinking agent, said crosslinking agent being reactive with the carboxyl or carboxylate groups or reactive in radical-induced copolymerization with the monomer solution; (ii) blending an amount of an aqueous colloidal dispersion of a rubbery polymeric material into the aqueous solution obtained in step (i), said amount being effective to increase the fracture resistance of the water swellable hydrogel-forming polymeric material; and (iii) initiating the polymerization of the aforementioned monomer/rubber blend.
Parent Case Info
This application claims priority under 35 U.S.C. §119 from Provisional Application Ser. No. 60/088,452 filed Jun. 8, 1998 which is hereby incorporated herein in its entirety.
US Referenced Citations (29)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0 689 817 |
Jan 1996 |
EP |
0 690 077 |
Jan 1996 |
EP |
WO 9422940 |
Oct 1994 |
WO |
Non-Patent Literature Citations (1)
Entry |
Carr et al., Interpolymer from Starch Xanthate and Polyamide-Polyamine-Epichlorohydrin Resin: Structure and Papermaking Application, Journal of Applied Polymer Science, 17:721-735 (1973). |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/088452 |
Jun 1998 |
US |