US4003844A
Expired / Lapsed
US
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Liquid crystal devices
Assignee: RCA Corp
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Filing: 1975-11-17
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Granted: 1977-01-18
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Expires: 1995-11-17
Abstract
Abstract The addition of certain nitrobenzene compounds to liquid crystal compositions having positive dielectric anisotropy, lowers the threshold voltage of electro-optic cells including such compositions. The nitrobenzene compounds have the formula <IMAGE> wherein R is an alkyl group of 1-20 carbon atoms, X1 and X3 can be hydrogen or nitro and X2 can be hydrogen, -NO2, <IMAGE> or-O-CH2CN, with the proviso that at least one of X1, X2 or X3 is a radical other than hydrogen.
Inventors
- 👤 Howard Sorkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:31
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/58; C09K19/582
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
95 words
In an electro-optic device comprising a twisted nematic liquid crystal composition between two electrodes, the improvement which comprises dissolving in said liquid crystal composition a nitrobenzene compound having the formula ##STR8##wherein R is an alkyl radical of 1-20 carbon atoms X 1 and X 3 independently can be hydrogen or nitro, X 2 can be hydrogen, nitro, or -O-CH 2 CN with the proviso that at least one of X 1 , X 2 or X 3 is a radical other than hydrogen, in an amount effective to lower the threshold voltage of said device.
Claim 2
Dependent Claim
95 words
In an electro-optic device comprising a twisted nematic liquid crystal composition between two electrodes, the improvement which comprises dissolving in said liquid crystal composition a nitrobenzene compound having the formula ##STR8##wherein R is an alkyl radical of 1-20 carbon atoms X 1 and X 3 independently can be hydrogen or nitro, X 2 can be hydrogen, nitro, or -O-CH 2 CN with the proviso that at least one of X 1 , X 2 or X 3 is a radical other than hydrogen, in an amount effective to lower the threshold voltage of said device.
Claim 3
Dependent Claim
10 words
A device according to claim 1 wherein R is methyl.
Claim 4
Dependent Claim
12 words
A device according to claim 1 wherein said nitrobenzene compound is p-nitroanisole.
Claim 5
Dependent Claim
51 words
A device according to claim 3 wherein said twisted nematic liquid crystal composition consists essentially of p-methoxybenzylidene-p' -n-butylaniline, p-ethoxybenzylidene-p'-n- butylaniline, and one or more members of the group having the formula ##STR9##wherein R' is an alkyl group of from 1-7 carbon atoms, and an effective amount of a chiral aligning agent.
Claim 6
Dependent Claim
45 words
A device according to claim 3 wherein said liquid crystal mixture consists essentially of p-methoxybenzylidene-p' -n-butylaniline, p-ethoxybenzylidene-p' -n-butylaniline, one or more members of the group having the formula ##STR10##wherein R' is an alkyl group of from 1-7 carbon atoms, 4-n-pentylphenyl-2-chloro-4-(4'-n-pentylbenzoyloxy)benzoate and a chiral aligning agent.
Claim 7
Dependent Claim
74 words
A liquid crystal composition comprising a nematic liquid crystal composition having positive dielectric anisotropy and a nitrobenzene compound of the formula ##STR11##wherein R is an alkyl group of 1-20 carbon atoms, X 1 and X 3 independently can be hydrogen or nitro, X 2 can be hydrogen, nitro, or --O-CH.sub. 2 CN with the proviso that at least one of X 1 , X 2 or X 3 is a radical other than hydrogen.
Claim 8
Dependent Claim
74 words
A liquid crystal composition comprising a nematic liquid crystal composition having positive dielectric anisotropy and a nitrobenzene compound of the formula ##STR11##wherein R is an alkyl group of 1-20 carbon atoms, X 1 and X 3 independently can be hydrogen or nitro, X 2 can be hydrogen, nitro, or --O-CH.sub. 2 CN with the proviso that at least one of X 1 , X 2 or X 3 is a radical other than hydrogen.
Claim 9
Dependent Claim
25 words
A liquid crystal composition according to claim 6 wherein the nitrobenzene compound has the formula ##STR12##wherein R is an alkyl group of 1-20 carbon atoms.
Claim 10
Dependent Claim
14 words
A liquid crystal composition according to claim 7 wherein said nitrobenzene compound is p-nitroanisole.
Claim 11
Dependent Claim
45 words
A liquid crystal composition according to claim 6 wherein said nematic liquid crystal composition having positive dielectric anisotropy consists essentially of p-methoxybenzylidene-p'-n-butylaniline, p-ethoxybenzylidene-p'-n-butylaniline and one or more members of the group having the formula ##STR13##wherein R' is an alkyl group of from 1-7 carbon atoms.
Claim 12
Dependent Claim
14 words
A liquid crystal composition according to claim 9 additionally containing a chiral aligning agent.
Claim 13
Dependent Claim
15 words
A liquid crystal composition according to claim 10 wherein said aligning agent is cholesteryl nonanoate.
Claim 14
Dependent Claim
14 words
A liquid crystal composition according to claim 11 wherein said nitrobenzene compound is p-nitroanisole.
Claim 15
Dependent Claim
57 words
A liquid crystal composition according to claim 6 wherein said nematic liquid crystal composition having positive dielectric anisotropy comprises p-methoxybenzylidene-p'-butylaniline, p-ethoxybenzylidene-p' -n-butylaniline, one or more members of the group having the formula ##STR14##wherein R' is an alkyl group of 1-7 carbon atoms and from about 5 to about 50% by weight of the total mixture of 4-n-pentylphenyl-2-chloro-4-(4'-n-pentylbenzoyloxy)benzoate.
Claim 16
Dependent Claim
14 words
A liquid crystal composition according to claim 13 additionally containing a chiral aligning agent.
Claim 17
Dependent Claim
15 words
A liquid crystal composition according to claim 14 wherein the aligning agent is cholesteryl nonanoate.
Claim 18
Dependent Claim
14 words
A liquid crystal composition according to claim 14 wherein said nitrobenzene compound is p-nitroanilsole.
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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) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |