US5147344A
Expired / Lapsed
US
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Hydrogel foams, and a process for their preparation
Assignee: Beiersdorf AG
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Filing: 1991-03-05
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Granted: 1992-09-15
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Expires: 2011-03-05
Abstract
Abstract Hydrogel foams a) based on gelatin and water, b) optionally containing polyvinyl alcohol, c) containing a crosslinking agent selected from the group comprising ca) the compounds of at least trivalent metals or semimetals, for example boric acid, borates, aluminium salts, titanates and alkyl titanates, and/or from the group comprising cb) organic and/or inorganic acids and/or salts thereof, for example gallic acid, gallates, phosphoric acids, phosphates, dihydroxybenzoic acid and dihydroxybenzoates, d) and optionally containing organic plasticizers, and/or auxiliary agents and/or additives.
Inventors
- 👤 Gunther Sachau
- 👤 Katrin Borgschulte
- 👤 Hanns Pietsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:15
CPC Classifications
A; A61; A61L; A61L26/00; A61L26/0061; A61L26/0085; A61L15/00; A61L15/16; A61L15/22; A61L15/32; A61L26/0009; A61L26/0028; A61L26/0038; A61L26/008; C; C08; C08L; C08L89/00; C08L89/04; C08L89/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
A hydrogel foam comprising by weight 0.01%-20.0% of at least one crosslinking agent selected from the group consisting of i) a compound of an at least trivalent metal or semimetal and ii) an organic or inorganic acid or salt thereof, 0.01%-30.0% of gelatin, 30.0%-0.0% of polyvinyl alcohol, 0.0%-50.0% of an organic plasticizer, 50.0%-90.0% of water and 0 to about 20% of at least one auxiliary agent or additive.
Claim 2
Dependent Claim
68 words
A hydrogel foam comprising by weight 0.01%-20.0% of at least one crosslinking agent selected from the group consisting of i) a compound of an at least trivalent metal or semimetal and ii) an organic or inorganic acid or salt thereof, 0.01%-30.0% of gelatin, 30.0%-0.0% of polyvinyl alcohol, 0.0%-50.0% of an organic plasticizer, 50.0%-90.0% of water and 0 to about 20% of at least one auxiliary agent or additive.
Claim 3
Dependent Claim
43 words
A hydrogel foam according to claim 1, comprising by weight 0.01%-10.0% of a crosslinking agent, 0.1%-15.0% of gelatin, 15.0%-1.0% of polyvinyl alcohol, 5.0%-30.0% of an organic plasticizer, 50.0%-80.0% of water and up to about 25% of at least one auxiliary agent or additive.
Claim 4
Dependent Claim
43 words
A hydrogel foam according to claim 1, comprising by weight 0.05%-50.0% of a crosslinking agent, 2.0%-15.0% of gelatin, 15.0%-2.0% of polyvinyl alcohol, 10.0%-30.0% of an organic plasticizer, 50.0%-80.0% of water and up to about 25% of at least one auxiliary agent or additive.
Claim 5
Dependent Claim
29 words
A hydrogel foam according to claim 1, wherein the crosslinking agent is selected from the group consisting of borax, boric acid, tetraethyl orthotitanate, orthophosphoric acid and potassium aluminium sulfate.
Claim 6
Dependent Claim
13 words
A hydrogel foam according to claim 1, wherein the crosslinking agent is acidic.
Claim 7
Dependent Claim
35 words
A hydrogel foam according to claim 1, wherein the crosslinking agent comprises at least one member selected from the group consisting of boric acid, a borate, an aluminium salt, a titanate and an alkyl titanate.
Claim 8
Dependent Claim
37 words
A hydrogel foam according to claim 1, wherein the crosslinking agent comprises at least one member selected from the group consisting of gallic acid, a gallate, phosphoric acid, a phosphate, dihydroxybenzoic acid and a dihydroxybenzoic acid salt.
Claim 9
Dependent Claim
11 words
A sheet-like support carrying a hydrogen foam according to claim 1.
Claim 10
Dependent Claim
49 words
A process for the preparation of a sheet-like structure according to claim 8, comprising: a) stirring with water gelatin and the polyvinyl alcohol if included, b) adding thereto the crosslinking agent, c) stirring vigorously, d) passing a stream of gas therethrough, and e) applying the mass to a support.
Claim 11
Dependent Claim
28 words
In the application to the skin of a sheet-like structure carrying a hydrogel foam, the improvement which comprises employing as said structure a structure according to claim 8.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-15 | 1996-03-16 | 1996-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-15 | 2000-03-16 | 2000-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-15 | 2004-03-16 | 2004-09-15 | $7700.00 | Window Closed / Lapsed |