US3923685A
Expired / Lapsed
US
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Liquid crystal compositions
Assignee: RCA Corp
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Filing: 1973-10-18
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Granted: 1975-12-02
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Expires: 1993-10-18
Abstract
Abstract Liquid crystal cells containing mixtures of cholesteric optically active p-alkoxybenzylidene-p''-aminobenzonitrile compounds with nematic liquid crystal compounds form cholesteric liquid crystals which change to the nematic state upon application of an electric field. Electro-optic devices including such liquid crystals have low voltage requirements and rapid response times.
Inventors
- 👤 Chan Soo Oh
- 👤 Edward F Pasierb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:25
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/58; C09K19/586; C07; C07C; C07C45/00; C07C45/61; C07C45/67; C07C45/68; C07C45/70; C07C45/71; C09K19/582
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
37 words
A CHOLESTERIC MIXTURE COMPRISING FROM 5-80 PERCENT BY WEIGHT OF AN OPTICALLY ACTIVE COMPOUND OF THE FORMULA 1-(CH3-CH2-CH(-CH3)-(CH2)N-O-),4-((4-(NC-)PHENYL)-N=CH-)BENZENE WHEREIN N IS AN INTEGER FROM 1 TO 5 AND A NEMATIC LIQUID CRYSTAL HAVING POSITIVE DIELECTRIC ANISOTROPY COMPOSITION.
Claim 2
Dependent Claim
37 words
A CHOLESTERIC MIXTURE COMPRISING FROM 5-80 PERCENT BY WEIGHT OF AN OPTICALLY ACTIVE COMPOUND OF THE FORMULA 1-(CH3-CH2-CH(-CH3)-(CH2)N-O-),4-((4-(NC-)PHENYL)-N=CH-)BENZENE WHEREIN N IS AN INTEGER FROM 1 TO 5 AND A NEMATIC LIQUID CRYSTAL HAVING POSITIVE DIELECTRIC ANISOTROPY COMPOSITION.
Claim 3
Dependent Claim
23 words
A mixture according to cLaim 1 wherein the nematic liquid crystal composition is selected from the group consisting of alkoxy- and acyloxybenzylidene anils.
Claim 4
Dependent Claim
28 words
A mixture according to claim 1 wherein the optically active compound is (S)-p-(4-methylhexoxy)benzylidene-p''-aminobenzonitrile and the nematic liquid crystal composition comprises an equimolar mixture of p-ethoxybenzylidene-p''-aminobenzonitrile, p-n-butoxybenzylidene-p''-aminobenzonitrile and p-n-octanoyloxybenzylidene-p''-aminobenzonitrile.
References Cited (Backward Citations)
US3796479A
Cited
US3815972A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |