US4840673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anisotropic cellulose articles, fibers, and films and method of producing same
Assignee: North Carolina State University
•
Filing: 1988-03-09
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Granted: 1989-06-20
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Expires: 2008-03-09
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
2026-11-03 09:46
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/02
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
16 words
A cellulose fiber formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 2
Dependent Claim
16 words
A cellulose fiber formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 3
Dependent Claim
15 words
The article according to claim 1 wherein said lyotropic mesophase solution exhibits the nematic phase.
Claim 4
Dependent Claim
16 words
A cellulosic film formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 5
Dependent Claim
16 words
A cellulosic film formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 6
Dependent Claim
39 words
A process for forming a lyotropic cellulose mesophase solution which comprises dissolving cellulose at a concentration of at least 3.5g/100mL in an ammonia/ammonium thiocyanate solvent having a concentration of ammonium thiocyanate of about 70 percent by weight or greater.
Claim 7
Dependent Claim
39 words
A process for forming a lyotropic cellulose mesophase solution which comprises dissolving cellulose at a concentration of at least 3.5g/100mL in an ammonia/ammonium thiocyanate solvent having a concentration of ammonium thiocyanate of about 70 percent by weight or greater.
Claim 8
Dependent Claim
20 words
A process according to claim 4 wherein said solvent has a concentration of about 75 percent by weight ammonium thiocyanate.
Claim 9
Dependent Claim
35 words
A process for selectively forming a lyotropic cellulose mesophase solution in the nematic phase which comprises dissolving cellulose in an ammonia/ammonium thiocyanate solvent having a composition of 24.5 percent ammonia and 75.5 percent ammonium thiocyanate.
Claim 10
Dependent Claim
35 words
A process for selectively forming a lyotropic cellulose mesophase solution in the nematic phase which comprises dissolving cellulose in an ammonia/ammonium thiocyanate solvent having a composition of 24.5 percent ammonia and 75.5 percent ammonium thiocyanate.
Claim 11
Dependent Claim
22 words
A process according to claim 6 wherein said solution has a cellulose concentration within the range of about 8g/100mL to about 16g/100mL.
Claim 12
Dependent Claim
35 words
A process for producing high tenacity, high modulus cellulosic fibers which comprises forming a lyotropic mesophase solution of cellulose in the nematic phase and extruding said solution into a coagulation bath to form fibers therefrom.
Claim 13
Dependent Claim
35 words
A process for producing high tenacity, high modulus cellulosic fibers which comprises forming a lyotropic mesophase solution of cellulose in the nematic phase and extruding said solution into a coagulation bath to form fibers therefrom.
Claim 14
Dependent Claim
23 words
The process according to claim 8 wherein said lyotropic mesophase solution of cellulose comprises a solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 15
Dependent Claim
29 words
The process according to claim 9 wherein said ammonia/ammonium thiocyanate solvent has a composition of about 24.5 percent by weight ammonia and about 75.5 percent by weight ammonium thiocyanate.
Claim 16
Dependent Claim
23 words
A process according to claim 10 wherein said cellulose solution has a cellulose concentration within the range of about 8g/100mL to about 16g/100mL.
Claim 17
Dependent Claim
31 words
A process for producing high tenacity, high modulus cellulosic films which comprises forming a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent and forming a film therefrom by casting.
Claim 18
Dependent Claim
31 words
A process for producing high tenacity, high modulus cellulosic films which comprises forming a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent and forming a film therefrom by casting.
Claim 19
Dependent Claim
16 words
A cellulose article formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 20
Dependent Claim
16 words
A cellulose article formed from a lyotropic mesophase solution of cellulose in an ammonia/ammonium thiocyanate solvent.
Claim 21
Dependent Claim
12 words
The article according to claim 13 in the form of a fiber.
Claim 22
Dependent Claim
12 words
The article according to claim 13 in the form of a film.
Claim 23
Dependent Claim
17 words
A cellulose article formed from a lyotropic mesophase solution of cellulose produced in accordance with claim 4.
Claim 24
Dependent Claim
17 words
A cellulose article formed from a lyotropic mesophase solution of cellulose produced in accordance with claim 6.
Claim 25
Dependent Claim
10 words
A cellulose fiber produced by the process of claim 8.
Claim 26
Dependent Claim
10 words
A cellulose fiber produced by the process of claim 9.
Claim 27
Dependent Claim
10 words
A cellulose fiber produced by the process of claim 10.
Claim 28
Dependent Claim
10 words
A cellulose fiber produced by the process by claim 11.
Claim 29
Dependent Claim
10 words
A cellulose film produced by the process of claim 12.
References Cited (Backward Citations)
US625033A
Cited
US1301652A
Cited
US1691345A
Cited
US2009015A
Cited
FR2340344A1
Cited
US4278790A
Cited
US4486119A
Cited
US4370168A
Cited
US4412059A
Cited
US4367191A
Cited
US4456638A
Cited
US4464323A
Cited
US4501886A
Cited
US4581399A
Cited
US4659470A
Cited
US4750939A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |