US4090975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mixtures of nematic liquid crystal materials
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1976-06-28
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Granted: 1978-05-23
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Expires: 1996-06-28
Abstract
Abstract Liquid crystal mixtures are disclosed which contain 30-60% of a Schiff's base nematic liquid crystal compound, 25-65% of a second nematic liquid crystal compound selected from the classes of azoxy, ester and biphenyl, and 5-15% of a triphenyl compound to raise the isotropic transition temperature. This combination results in liquid crystal compositions having unexpectedly wide nematic temperature ranges.
Inventors
- 👤 Ralph E. Aldrich
- 👤 William J. Cumming
- 👤 William A. Simmons, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:20
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/48
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
121 words
A liquid crystal composition having a freezing point of at most about -50° C and an isotropic transition point of at least about 80° C which, based upon 100% by weight, consists essentially of: a. from about 10% to about 14% by weight of bis(4'-n-octyloxybenzal)-2-chloro-1,4-phenylenediamine; b. from about 40% to about 60% by weight of a Schiff's base nematic liquid crystal compound selected from the group consisting of p-ethoxybenzylidene-p'-n-butylaniline and p-butoxybenzylidene-p'-n-butylaniline; and, c. from about 35 to about 50% by weight of a mixture of nematic liquid crystal azoxy compounds represented by the structural formula ##STR17## wherein one of R and R' is C 1 -C 8 alkyl and the other of R and R' is C 1 -C 8 alkoxy.
Claim 2
Dependent Claim
121 words
A liquid crystal composition having a freezing point of at most about -50° C and an isotropic transition point of at least about 80° C which, based upon 100% by weight, consists essentially of: a. from about 10% to about 14% by weight of bis(4'-n-octyloxybenzal)-2-chloro-1,4-phenylenediamine; b. from about 40% to about 60% by weight of a Schiff's base nematic liquid crystal compound selected from the group consisting of p-ethoxybenzylidene-p'-n-butylaniline and p-butoxybenzylidene-p'-n-butylaniline; and, c. from about 35 to about 50% by weight of a mixture of nematic liquid crystal azoxy compounds represented by the structural formula ##STR17## wherein one of R and R' is C 1 -C 8 alkyl and the other of R and R' is C 1 -C 8 alkoxy.
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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) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |