US5750585A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Super absorbent hydrogel foams
Assignee: Purdue Research Foundation
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Filing: 1995-04-04
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Granted: 1998-05-12
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Expires: 2015-04-04
Abstract
Abstract A water swellable foam matrix formed as a macroporous solid comprising a foam stabilizing agent and a polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a multiolefin-functional crosslinking agent is described. The foam matrix is characterized by rapid swelling and high water swelling ratios.
Inventors
- 👤 Kinam Park
- 👤 Haesun Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:00
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/48; A61K; A61K9/00; A61K9/10; A61K9/12; A61K9/122; A61K9/20; A61K9/2004; A61K9/2022; A61K9/2027; A61L15/425; A61L15/60
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
68 words
An absorbent hydrogel foam comprising a solid phase comprising a surfactant and a polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups; and a gas phase, wherein the ratio of the volume of the gas phase to the volume of the solid phase is at least one.
Claim 2
Dependent Claim
68 words
An absorbent hydrogel foam comprising a solid phase comprising a surfactant and a polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups; and a gas phase, wherein the ratio of the volume of the gas phase to the volume of the solid phase is at least one.
Claim 3
Dependent Claim
12 words
The hydrogel foam of claim 1, wherein said surfactant is a protein.
Claim 4
Dependent Claim
12 words
The hydrogel foam of claim 1, wherein said crosslinking agent is biodegradeable.
Claim 5
Dependent Claim
41 words
The hydrogel foam of claim 1, wherein a volume of said foam, having a size greater than 1 mm in its smallest dimension, exhibits a water swelling ratio of at least 15 within one hour of contact with an aqueous solution.
Claim 6
Dependent Claim
41 words
The hydrogel foam of claim 1, wherein a volume of said foam, having a size greater than 1 mm in its smallest dimension, exhibits at least 50% of its maximum swelling ratio within one hour of contact with an aqueous solution.
Claim 7
Independent Claim
85 words
A method for producing a water absorbent hydrogel foam matrix, said method comprising the steps of polymerizing at least one hydrophilic olefin monomer compound in an aqueous solution, said aqueous solution comprising about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups and a surfactant; introducing gas into the monomer solution during said polymerization step to form a foamed polymer matrix hydrogel foam; contacting the hydrogel foam with a volatile water miscible solvent; and drying said hydrogel foam.
Claim 8
Independent Claim
85 words
A method for producing a water absorbent hydrogel foam matrix, said method comprising the steps of polymerizing at least one hydrophilic olefin monomer compound in an aqueous solution, said aqueous solution comprising about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups and a surfactant; introducing gas into the monomer solution during said polymerization step to form a foamed polymer matrix hydrogel foam; contacting the hydrogel foam with a volatile water miscible solvent; and drying said hydrogel foam.
Claim 9
Dependent Claim
28 words
The method of claim 6, wherein the step of drying comprises contacting the hydrogel foam with an absorbent material followed by air drying the matrix at room temperature.
Claim 10
Dependent Claim
23 words
The method of claim 7 further comprising the step of drawing warmed air across the hydrogel foam surface during the step of drying.
Claim 11
Dependent Claim
83 words
A water swellable hydrogel foam formed as a macroporous solid comprising a foam stabilizing agent and a polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups, wherein a volume of said hydrogel foam, having a size greater than 2 mm in its smallest dimension, exhibits a water swelling ratio of at least 15 within one hour of contact with an aqueous solution.
Claim 12
Dependent Claim
83 words
A water swellable hydrogel foam formed as a macroporous solid comprising a foam stabilizing agent and a polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups, wherein a volume of said hydrogel foam, having a size greater than 2 mm in its smallest dimension, exhibits a water swelling ratio of at least 15 within one hour of contact with an aqueous solution.
Claim 13
Dependent Claim
12 words
The hydrogel foam of claim 9 wherein the crosslinking agent is biodegradable.
Claim 14
Dependent Claim
80 words
A water swellable hydrogel foam formed as a macroporous solid comprising a surfactant and polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups, wherein a volume of said hydrogel foam, having a size greater than 1 mm in its smallest dimension, exhibits greater than 50% of its maximum swelling ratio within one hour of contact with an aqueous solution.
Claim 15
Dependent Claim
80 words
A water swellable hydrogel foam formed as a macroporous solid comprising a surfactant and polymer or copolymer of a free radical polymerizable hydrophilic olefin monomer crosslinked with about 0.1 to about 10% by weight of a crosslinking agent having at least two alkenyl groups, wherein a volume of said hydrogel foam, having a size greater than 1 mm in its smallest dimension, exhibits greater than 50% of its maximum swelling ratio within one hour of contact with an aqueous solution.
Claim 16
Dependent Claim
12 words
The hydrogel foam of claim 11 wherein the crosslinking agent is biodegradable.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |