US4750939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anisotropic cellulose solutions, fibers, and films formed therefrom
Assignee: North Carolina State University
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Filing: 1986-12-02
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Granted: 1988-06-14
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Expires: 2006-12-02
Abstract
Abstract Lyotropic mesophase (liquid crystalline) solutions of cellulose are formed in an ammonia/ammonium thiocyanate solvent. The nature of the solution can be controlled to selectively produce lyotropic cellulose mesophases having either nematic or cholesteric character. High strength, high modulus fibers are produced from a lyotropic mesophase solution of cellulose essentially in the nematic phase. The films are prepared from mesophase solutions of cellulose that are mainly in the cholesteric phase.
Inventors
- 👤 John A. Cuculo
- 👤 Michael H. Theil
- 👤 Kap S. Yang
- 👤 Yue S. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:01
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
11 words
A lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 2
Dependent Claim
11 words
A lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 3
Dependent Claim
12 words
A cellulose solutio according to claim 1 which exhibits the nematic phase.
Claim 4
Dependent Claim
12 words
A cellulose solution according to claim 1 which exhibits the cholesteric phase.
Claim 5
Dependent Claim
33 words
A cellulose solution according to claim 1 wherein said solvent has a composition of about 24.5 percent (w/w) ammonia and about 75.5 percent (w/w) ammonium thiocyanate and the solution includes the nematic phase.
Claim 6
Dependent Claim
17 words
A lyotropic mesophase solution of cellulose which exhibs the nematic phase in the absence of external stimulus.
Claim 7
Dependent Claim
17 words
A lyotropic mesophase solution of cellulose which exhibs the nematic phase in the absence of external stimulus.
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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) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |