US4464321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of chitosan fibers
Assignee: Anic SpA
•
Filing: 1982-10-07
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Granted: 1984-08-07
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Expires: 2002-10-07
Abstract
Abstract Hollow chitosan fibres for use in ultrafiltration processes are described, and which can be plasticized by the addition of glycerin such that they contain this latter in a quantity variable between 0.5 and 5% by weight with respect to the polymer. Said fibres are prepared by the wet spinning of acid chitosan solutions, using an alkali solution as the external fibre coagulant and a gaseous phase containing a basic gaseous component as the internal fibre coagulant.
Inventors
- 👤 Francesco Pittalis
- 👤 Francesco Bartoli
- 👤 Guido Giovannoni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:34
CPC Classifications
D; D01; D01F; D01F9/00; B; B01; B01D; B01D69/00; B01D69/08; B01D71/00; B01D71/06; B01D71/08; D01D; D01D5/00; D01D5/24; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2973; Y10T428/2975
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
71 words
A process for preparing hollow chitosan fibres usable in ultrafiltration and dialytic processes, having a size of between 0.1 and 1 mm. and a thickness of between 0.005 and 0.025 mm. said process comprising wet spinning an acid solution of chitosan through a suitable hollow fibre spinneret, and using an alkali solution as the external fibre coagulant and a gaseous phase containing a basic gaseous component as the internal fibre coagulant.
Claim 2
Dependent Claim
71 words
A process for preparing hollow chitosan fibres usable in ultrafiltration and dialytic processes, having a size of between 0.1 and 1 mm. and a thickness of between 0.005 and 0.025 mm. said process comprising wet spinning an acid solution of chitosan through a suitable hollow fibre spinneret, and using an alkali solution as the external fibre coagulant and a gaseous phase containing a basic gaseous component as the internal fibre coagulant.
Claim 3
Dependent Claim
37 words
A process as claimed in claim 1, wherein the chitosan solution is prepared by dissolving this polymer in acetic or formic acid, the polymer concentration lying between 3.5 and 5% by weight with respect to the solution.
Claim 4
Dependent Claim
25 words
A process for preparing hollow chitosan fibres as claimed in claims 1 or 2, characterized in that the polymer solution and the coagulate contain glycerin.
Claim 5
Dependent Claim
18 words
A process for preparing hollow chitosan fibres as claimed in claim 1 wherein the gaseous component is ammonia.
Claim 6
Dependent Claim
18 words
A process for preparing hollow chitosan fibres as claimed in claim 2 wherein the gaseous component is ammonia.
References Cited (Backward Citations)
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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) | 1987-08-07 | 1988-02-06 | 1988-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-07 | 1992-02-06 | 1992-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-07 | 1996-02-06 | 1996-08-07 | $7700.00 | Window Closed / Lapsed |