Patent US5338766A successfully refreshed from Google Patents.
US5338766A
Expired / Lapsed
US
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Superabsorbent polymer foam
Assignee: Procter and Gamble Co
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Filing: 1993-03-26
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Granted: 1994-08-16
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Expires: 2013-03-26
Abstract
Abstract An improved superabsorbent polymer foam having a morphology to provide improved absorptive properties is disclosed. The foam preferably comprises a superabsorbent polymer formed from a substantially water-soluble, unsaturated monomer having neutralized carboxyl groups and a substantially water-soluble internal crosslinking agent. The monomer and crosslinking agent are expanded in the presence of a substantially water-insoluble blowing agent and a suitable solvent and reacted to form a superabsorbent polymer foam having substantially continuous, intercommunicating channels substantially throughout the foam and a relatively high surface area to mass ratio. Methods for making the foam and absorbent products, members and articles containing the foam are also disclosed.
Inventors
- 👤 Dean V. Phan
- 👤 Paul D. Trokhan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:46
CPC Classifications
A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; A61L15/22; A61L15/24; A61L15/425; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/2481; Y10T428/24851; Y10T428/249921; Y10T428/249953; Y10T428/249975; Y10T428/249978; Y10T428/249979; Y10T428/24998; Y10T428/249986; Y10T442/00; Y10T442/60; Y10T442/647; Y10T442/652
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
60 words
A superabsorbent polymer foam comprising a plurality of mutually connected struts of superabsorbent polymer material to form open cells, said foam having: (a) a surface area to mass ratio of at least about 0.2 m 2 /g; (b) an average cell size of less than about 100 microns; and (c) a density of less than about 0.5 g/cm 3 .
Claim 2
Dependent Claim
60 words
A superabsorbent polymer foam comprising a plurality of mutually connected struts of superabsorbent polymer material to form open cells, said foam having: (a) a surface area to mass ratio of at least about 0.2 m 2 /g; (b) an average cell size of less than about 100 microns; and (c) a density of less than about 0.5 g/cm 3 .
Claim 3
Dependent Claim
18 words
The superabsorbent polymer foam of claim 1 having an average cell size of less than about 50 microns.
Claim 4
Dependent Claim
18 words
The superabsorbent polymer foam of claim 1 having an average cell size of less than about 20 microns.
Claim 5
Dependent Claim
23 words
The superabsorbent polymer foam of claim 1, 2, or 3 further characterized by a cell size distribution value of less than about 5.
Claim 6
Dependent Claim
132 words
A superabsorbent polymer foam comprising a plurality of mutually connected struts of superabsorbent polymer material to form open cells, said superabsorbent polymer material comprising reactants capable of forming said superabsorbent polymer material, said reactants being capable of being made substantially soluble in a solvent; said reactants being expanded in the presence of (i) said solvent and (ii) a blowing agent which is substantially insoluble in said solvent to form an expanded structure; said reactants being reacted to form a superabsorbent polymer material which is substantially insoluble in said solvent; the superabsorbent polymer foam having: (a) a surface area to mass ratio of at least about 0.2 m 2 /g; (b) an average cell size of less than about 100 microns; and (c) a density of less than about 0.5 g/cm 3 .
Claim 7
Dependent Claim
132 words
A superabsorbent polymer foam comprising a plurality of mutually connected struts of superabsorbent polymer material to form open cells, said superabsorbent polymer material comprising reactants capable of forming said superabsorbent polymer material, said reactants being capable of being made substantially soluble in a solvent; said reactants being expanded in the presence of (i) said solvent and (ii) a blowing agent which is substantially insoluble in said solvent to form an expanded structure; said reactants being reacted to form a superabsorbent polymer material which is substantially insoluble in said solvent; the superabsorbent polymer foam having: (a) a surface area to mass ratio of at least about 0.2 m 2 /g; (b) an average cell size of less than about 100 microns; and (c) a density of less than about 0.5 g/cm 3 .
Claim 8
Dependent Claim
44 words
The superabsorbent polymer foam of claim 5 wherein said reactants comprise: (a) a substantially water-soluble, unsaturated monomer comprising neutralized carboxyl groups; and (b) a substantially water-soluble internal crosslinking agent which is capable of reacting with said monomer to form a substantially water-insoluble polymer material.
Claim 9
Dependent Claim
34 words
The superabsorbent polymer foam of claim 6 wherein said monomer is selected from the group consisting of acrylic acid, maleic acid, methacrylic acid, fumaric acid, itaconic acid, maleic arthydride, ethylacrylate, butylacrylate, and mixtures thereof.
Claim 10
Dependent Claim
31 words
The superabsorbent polymer foam of claim 7 wherein said internal crosslinking agent is selected from the group consisting of N,N'-methylenebisacrylamide, triallylamine, triallylphosphate, and di- or polyglycidyl ethers of aliphatic polyvalent alcohols.
Claim 11
Dependent Claim
23 words
The superabsorbent polymer foam of claim 8 wherein said solvent is selected from the group consisting of water, lower alcohols, or mixtures thereof.
Claim 12
Dependent Claim
26 words
The superabsorbent polymer foam of claim 9 wherein said blowing agent comprises a substantially water-insoluble compound having a vaporization temperature of less than about 50° C.
Claim 13
Dependent Claim
34 words
The superabsorbent polymer foam of claim 10 wherein said internal crosslinking agent is expanded and reacted with said monomer in the presence of a surfactant, an initiator, a viscosity control agent, or mixtures thereof.
Claim 14
Dependent Claim
32 words
The superabsorbent polymer foam of claim 6 or 11 having an average cell size of less than about 50 microns and a cell distribution value of from about 1 to about 3.
Claim 15
Dependent Claim
18 words
The superabsorbent polymer foam of claim 6 wherein said superabsorbent polymer material additionally comprises an external crosslinking agent.
Claim 16
Dependent Claim
17 words
The superabsorbent polymer foam of claim 6 wherein the superabsorbent polymer foam is flexibilized by a plasticizer.
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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) | 1997-08-15 | 1998-02-14 | 1998-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-15 | 2002-02-14 | 2002-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-15 | 2006-02-14 | 2006-08-16 | $7700.00 | Window Closed / Lapsed |