Superabsorbent Polymer Compositions Having A Triggering Composition
AssigneeEvonik Stockhausen GmbH
InventorsGonglu Tian, Scott J. Smith, Yaru Shi, Richard N. Dodge, Jian Qin
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Abstract
The present invention relates to absorbent compositions which exhibit swelling, deswelling, and reswelling behavior. More specifically, absorbent compositions of this invention swell and absorb fluids after exposure to aqueous fluids, deswell and release fluids from the swollen absorbent compositions, and may also reswell and absorb fluids. The swelling-deswelling-reswelling behavior allows enhanced liquid distribution in absorbent composites.
Claims22
1-29. (canceled)
An absorbent composition comprising:
- a) superabsorbent polymer partially neutralized crosslinked poly(acrylic acid) wherein from about 40 molar percent to about 60 molar percent of the acidic functional groups are neutralized, and having a pH less than about 6.0;
- b) a deswell triggering agent comprising a first water-soluble chemical comprising cations X having an ionized valence of two or more;
- and
- c) a reswell triggering agent comprising a second water-soluble chemical comprising anions Y;
- wherein the cations X of the first water-soluble chemical are capable of complexing with the anionic functional groups of the SAP;
- and the anions Y of the second water-soluble chemical are capable of complexing with the cations X to form a salt having a solubility product constant Ksp<10−5.
An absorbent composition comprising:
- a) a superabsorbent polymer comprising partially neutralized crosslinked poly(acrylic acid) wherein from about 40 molar percent to about 60 molar percent of the acidic functional groups are neutralized, having a pH less than about 6.0;
- b) a deswell triggering agent comprising a first water-soluble chemical;
- c) a reswell triggering agent comprising a second water-soluble chemical having a pH of about 10 or more;
- wherein when the absorbent composition is contacted with an aqueous fluid, the superabsorbent polymer exhibits swell-deswell-reswell behavior and the resultant swollen superabsorbent polymer has a pH higher than the superabsorbent polymer of a);
- and
- wherein the deswell triggering agent has a release profile for releasing the first water-soluble chemical wherein the release profile is selected from a singular release profile or a sigmoidal release profile, and the reswell triggering agent has a sigmoidal release profile for releasing the second water-soluble chemical;
- wherein the first water-soluble chemical has a higher cumulative release than the second water-soluble chemical after exposure to aqueous fluid and before about 100% release.
An absorbent composition comprising a superabsorbent polymer, a deswell triggering agent (TAD) and a reswell triggering agent (TAR);
- wherein the superabsorbent polymer, the TAD and the TAR are all selected from either solubility-based chemistry or neutralization-based chemistry groupings;
- wherein the TAD comprises a first water-soluble solid chemical wherein the TAD has a release profile for releasing the water-soluble solid chemical wherein the release profile is selected from a singular release profile or a sigmoidal release profile;
- wherein the TAR comprises a second water-soluble solid chemical wherein the reswell triggering agent has a sigmoidal release profile for releasing the second water-soluble solid chemical;
- wherein the first water-soluble chemical has a higher cumulative release than the second water-soluble chemical after exposure to aqueous fluid and before about 100% release.
Dependencies are inferred from the claim text.