Patent US4501886A successfully refreshed from Google Patents.
US4501886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cellulosic fibers from anisotropic solutions
Assignee: EIDP Inc
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Filing: 1983-08-01
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Granted: 1985-02-26
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Expires: 2003-08-01
Abstract
Abstract High strength, high modulus cellulose triacetate fibers are produced by spinning a 30-42% by weight solution of cellulose triacetate having an acetyl content of at least 42.5% and an inherent viscosity of at least 5 from a solvent mixture comprising trifluoroacetic acid and another solvent having a molecular weight of less than 160 in a mol ratio of 0.3-3.0 through an air gap into a coagulating bath. The fibers are optionally heat treated under tension or saponified to provide high strength high modulus regenerated cellulose fibers.
Inventors
- 👤 John P. O'Brien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:17
CPC Classifications
D; D01; D01F; D01F11/00; D01F11/02; D01F2/00; D01F2/24; D01F2/28
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
Cellulose triacetate fibers having at least 42.5% by weight acetyl groups, an inherent viscosity in hexafluoroisopropanol at 0.5 g/dl of at least 5, a tenacity of at least 10 dN/tex, an orientation angle of 35° or less, an AACS value of at least 130 and an exotherm in their DSC scan in the range between 190° and 240° C.
Claim 2
Dependent Claim
59 words
Cellulose triacetate fibers having at least 42.5% by weight acetyl groups, an inherent viscosity in hexafluoroisopropanol at 0.5 g/dl of at least 5, a tenacity of at least 10 dN/tex, an orientation angle of 35° or less, an AACS value of at least 130 and an exotherm in their DSC scan in the range between 190° and 240° C.
Claim 3
Dependent Claim
13 words
The fibers of claim 1 having at least 44% by weight acetyl groups.
Claim 4
Dependent Claim
18 words
The fibers of claim 1 having an inherent viscosity in hexafluoroisopropanol at 0.5 g/dl of at least 6.3.
Claim 5
Dependent Claim
45 words
Cellulose triacetate fibers having at least 42.5% by weight acetyl groups, an inherent viscosity in hexafluoroisopropanol at 0.5 g/dl of at least 5, a tenacity of at least 10.6 dN/tex, a modulus of at least 155 dN/tex, and an orientation angle of 20° or less.
Claim 6
Dependent Claim
45 words
Cellulose triacetate fibers having at least 42.5% by weight acetyl groups, an inherent viscosity in hexafluoroisopropanol at 0.5 g/dl of at least 5, a tenacity of at least 10.6 dN/tex, a modulus of at least 155 dN/tex, and an orientation angle of 20° or less.
Claim 7
Dependent Claim
27 words
Regenerated cellulose fibers having a tenacity of at least 12.4 dN/tex and a modulus of at least 220 dN/tex, and an orientation angle of 18° or less.
Claim 8
Dependent Claim
27 words
Regenerated cellulose fibers having a tenacity of at least 12.4 dN/tex and a modulus of at least 220 dN/tex, and an orientation angle of 18° or less.
Claim 9
Dependent Claim
14 words
Regenerated cellulose fibers of claim 5 having an orientation angle of 10° or less.
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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) | 1988-02-26 | 1988-08-27 | 1989-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-26 | 1992-08-27 | 1993-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-26 | 1996-08-27 | 1997-02-26 | $7700.00 | Window Closed / Lapsed |