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US4824217A
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Compounds for ferroelectric liquid crystal devices
Assignee: Qinetiq Ltd
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Filing: 1985-11-08
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Granted: 1989-04-25
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Expires: 2005-11-08
Abstract
Abstract ##STR1## Ferroelectric smectic liquid crystal mixtures are provided consisting of two constituents; a smectic host and another containing a chiral compound in which rotation of the chiral center relative to the molecular core is sterically hindered, so that the chiral compound induces a high Ps in the mixture. A preferred class of chiral compounds is those derived from naturally occurring compounds with chiral groups, especially α-hydroxycarboxylic acids, amino acids and terpenoids, e.g. with chiral groups (I), (II), (III). The chiral group is incorporated into a compound containing a mesogenic combination of groups, e.g. with chains of cyclic groups and some mesogenic combinations are described.
Inventors
- 👤 Lawrence K. M. Chan
- 👤 David Coates
- 👤 Peter A. Gemmell
- 👤 George W. Gray
- 👤 David Lacey
- 👤 Kenneth J. Toyne
- 👤 Daniel J. S. Young
- 👤 Matthew F. Bone
- 👤 Adam Jackson
- 👤 Richard M. Scrowston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:41
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/06; C09K19/08; C09K19/30; C09K19/3001; C09K19/02; C09K19/0225; C09K19/10; C09K19/12; C09K19/126; C09K19/20; C09K19/2007; C09K19/2021; C09K19/2028; C09K19/22; C09K19/32; C09K19/42; C09K19/50; C09K19/52; C09K19/58; C09K19/586; C09K2019/3095
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A ferroelectric smectic liquid crystal mixture in which a first constituent of the mixture is chiral, which first constituent is admixed with a second constituent which exhibits a tilted smectic C phase, and wherein the said first constituent consists of one or more compounds having a molecular structure in which the chiral group of the molecule is sterically hindered with respect to the main molecular core, said compound(s) having a molecular structure: ##STR75## wherein R 1 is n-alkyl or n-alkoxy containing 5-12 carbon atoms, p is 0 or 1, R 2 is C 1 -C 4 n-alkyl or n-alkoxy, provided that if p is 0, then R 2 is C 1 -C 4 n-alkyl.
Claim 2
Dependent Claim
114 words
A ferroelectric smectic liquid crystal mixture in which a first constituent of the mixture is chiral, which first constituent is admixed with a second constituent which exhibits a tilted smectic C phase, and wherein the said first constituent consists of one or more compounds having a molecular structure in which the chiral group of the molecule is sterically hindered with respect to the main molecular core, said compound(s) having a molecular structure: ##STR75## wherein R 1 is n-alkyl or n-alkoxy containing 5-12 carbon atoms, p is 0 or 1, R 2 is C 1 -C 4 n-alkyl or n-alkoxy, provided that if p is 0, then R 2 is C 1 -C 4 n-alkyl.
Claim 3
Dependent Claim
40 words
A mixture as claimed in claim 1 wherein the extent of the steric hindrance is such that the first contituent produces, in the mixture, an extrapolated spontaneous polarisation (Ps) with a maximum value that exceeds 10 n Ccm -2 .
Claim 4
Dependent Claim
21 words
A mixture as claimed in claim 2 wherein the maximum value of Ps is greater than 20 n Ccm -2 .
Claim 5
Dependent Claim
26 words
A mixture as claimed in claim 1 wherein the said first constituent has a structure: ##STR76## wherein R 1 is n-alkoxy and R 2 is n-alkoxy.
Claim 6
Dependent Claim
12 words
A mixture as claimed in claim 4 wherein R 2 is n-butyloxy.
Claim 7
Dependent Claim
18 words
A mixture as claimed in claim 4 or 5 wherein R 1 is n--C 8 H 17 O--.
Claim 8
Dependent Claim
26 words
A mixture as claimed in claim 1 wherein the said first constituent has a structure: ##STR77## wherein R 1 is n-alkoxy and R 2 is n-alkyl.
Claim 9
Dependent Claim
12 words
A mixture as claimed in claim 7 wherein R 2 is ethyl.
Claim 10
Dependent Claim
24 words
A mixture as claimed in claim 7 or 8 wherein R 1 is n--C 8 H 17 O-- or n--C 9 H 19 O--.
Claim 11
Dependent Claim
160 words
A liquid crystal electro-optic display device comprising two substrates defining inner surfaces, at least one of said substrates being optically transparent, electrodes on the inner surfaces of the substrates and a layer of a liquid crystal material sandwiched between the substrates, wherein the liquid crystal material is a ferroelectric smectic liquid crystal mixture in which a first constituent of the mixture is chiral, which first constituent is admixed with a second constituent which exhibits a tilted smectic C phase, and wherein the first constituent consists of one or more compounds having a molecular structure in which the chiral group of the molecule is sterically hindered with respect to the main molecular core, said compound(s) having a molecular structure: ##STR78## wherein R 1 is n-alkyl or n-alkoxy containing 5-12 carbon atoms, p is 0 or 1, R 2 is C 1 -C 4 n-alkyl or n-alkoxy, provided that if p is 0, then R 2 is C 1 -C 4 n-alkyl.
Claim 12
Dependent Claim
160 words
A liquid crystal electro-optic display device comprising two substrates defining inner surfaces, at least one of said substrates being optically transparent, electrodes on the inner surfaces of the substrates and a layer of a liquid crystal material sandwiched between the substrates, wherein the liquid crystal material is a ferroelectric smectic liquid crystal mixture in which a first constituent of the mixture is chiral, which first constituent is admixed with a second constituent which exhibits a tilted smectic C phase, and wherein the first constituent consists of one or more compounds having a molecular structure in which the chiral group of the molecule is sterically hindered with respect to the main molecular core, said compound(s) having a molecular structure: ##STR78## wherein R 1 is n-alkyl or n-alkoxy containing 5-12 carbon atoms, p is 0 or 1, R 2 is C 1 -C 4 n-alkyl or n-alkoxy, provided that if p is 0, then R 2 is C 1 -C 4 n-alkyl.
References Cited (Backward Citations)
US4293193A
Cited
US4394070A
Cited
US4460492A
Cited
US4613209A
Cited
US4600526A
Cited
US4576732A
Cited
US4596667A
Cited
US4622165A
Cited
US4650600A
Cited
EP0156726A1
Cited
US4668829A
Cited
US4775223A
Cited
US4769176A
Cited
US4784793A
Cited
US4764619A
Cited
US4753752A
Cited
US4705874A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |