US5980930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fibres
Assignee: Convatec Technologies Inc
•
Filing: 1994-01-19
•
Granted: 1999-11-09
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Expires: 2014-01-19
Abstract
Abstract Highly absorbent alginate fibers are described which have use in the manufacture of dressings. The fibers and dressings described are highly swellable while also being soluble, rather than just being soluble. This is a considerable advantage for use in environments where high absorption coupled with biodegradability is desired, for example, in wound dressings such as dressings for ulcers or burns.
Inventors
- 👤 John Charles Fenton
- 👤 Bryan Griffiths
- 👤 Peter Michael John Mahoney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:21
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/01; A61F13/01034; A61F13/01042; A61L; A61L15/00; A61L15/16; A61L15/22; A61L15/28; D; D01; D01F; D01F9/00; D01F9/04; A61F13/06; A61F13/064; A61F13/069; A61F2013/00089; A61F2013/00157; A61F2013/00217; A61F2013/00221; A61F2013/00225; A61F2013/00361; A61F2013/00365; A61F2013/00519; A61F2013/00523; Y; Y10; Y10T; Y10T442/00; Y10T442/20; Y10T442/2484; Y10T442/2525
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
26 words
Alginate fabric which absorbs at least 40.0 g of deionized water per gram of fabric and 80 to 280 times its own weight of deionized water.
Claim 2
Dependent Claim
26 words
Alginate fabric which absorbs at least 40.0 g of deionized water per gram of fabric and 80 to 280 times its own weight of deionized water.
Claim 3
Dependent Claim
42 words
Alginate fabric as claimed in claim 1 which comprises a febre characterized in that a plot of the first order derivative of percentage weight loss of the fibre with temperature against temperature has two maxima in the range 100° to 400° C.
Claim 4
Dependent Claim
37 words
Alginate fabric as claimed in claim 2 in which the plot of the first order derivative of percentage weight loss of the fibre with temperature against temperature has two maxima in the range 200° to 300° C.
Claim 5
Dependent Claim
23 words
Alginate fabric as claimed in claim 1 which comprises a fibre characterized in that its glass transition range is less than 30° C.
Claim 6
Dependent Claim
23 words
Alginate fabric as claimed in claim 1 which comprises a fibre which absorbs at least 40.0 g deionized water per gram of fibre.
Claim 7
Dependent Claim
91 words
A process for the preparation of alginate fibres to prepare alginate fabric as claimed in claim 1 which comprises the following steps: (1) treating alginate fibres with a suitable acid so as to produce fibres comprising approximately 90-98% alginic acid fibres; (2) treating the alginic acid fibres with a saturated aqueous solution of mono- or divalent cations; (3) washing the fibres with water until imbibition of water by the fibres has effectively ceased; and (4) treating the fibres with a source of a cation capable of forming a water-soluble alginate salt.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 6 wherein the alginate fibres in step 1 are calcium alginate.
Claim 9
Dependent Claim
17 words
A process as claimed in claim 7 wherein the acid used in step (1) is hydrochloric acid.
Claim 10
Dependent Claim
24 words
A process as claimed in any of claims 6 to 8 wherein the solution used in step (2) is a solution of sodium ions.
Claim 11
Dependent Claim
19 words
A process as claimed in any of claims 6 to 8 wherein step (3) comprises washing in deionized water.
Claim 12
Dependent Claim
23 words
A process as claimed in any of claims 6 to 8 wherein other ions and/or medicaments are included after or during step 4.
Claim 13
Dependent Claim
51 words
Alginate fabric as claimed in claim 1 which comprises a fibre characterized in that a plot of the first order derivative of percentage weight loss of the fibre with temperature against temperature has two maxima in the range 100° to 400° C. and which contains the sodium salt of hyaluronic acid.
Claim 14
Dependent Claim
19 words
A dressing which comprises a fibre or fabric as claimed in any of claims 1 or 2 to 5.
Claim 15
Dependent Claim
26 words
A dressing as claimed in claim 13 in the form of a sterile dressing for the treatment of a burn or ulcer or other exuding wound.
Claim 16
Dependent Claim
31 words
A process as claimed in claim 6 wherein the alginate fibres in step (1) are treated with a suitable acid so as to produce fibres comprising approximately 95-98% alginic acid fibres.
Claim 17
Dependent Claim
32 words
Alginate fabric as claimed in claim 1 which comprises a fibre characterized in that its glass transition range is less than 30° C. and which contains the sodium salt of hyaluronic acid.
Claim 18
Dependent Claim
32 words
Alginate fabric as claimed in claim 1 which comprises a fibre which absorbs at least 40.0 g deionized water per gram of fibre and which contains the sodium salt of hyaluronic acid.
Claim 19
Dependent Claim
19 words
A fabric as claimed in claim 1, 2, 5, 12, 16 or 17 which is a wet layered fabric.
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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) | 2002-11-08 | 2003-05-10 | 2003-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-08 | 2007-05-10 | 2007-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-08 | 2011-05-10 | 2011-11-09 | $7700.00 | Window Closed / Lapsed |