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US4506957A
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Liquid crystal materials containing pleochroic anthraquinone dyes
Assignee: Qinetiq Ltd
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Filing: 1983-04-06
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Granted: 1985-03-26
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Expires: 2003-04-06
Abstract
Abstract A material suitable for a guest-host liquid crystal device comprises a solution of a liquid crystal material and a pleochroic dye characterized in that the dye comprises at least one anthraquinone compound free from water-solubilizing and ionic substituents and having the formula: ##STR1## wherein each of R and R 1 independently represents an n-alkyl group having from 4 to 7 carbon atoms inclusive and wherein each of R 2 and R 3 is independently selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms inclusive.
Inventors
- 👤 Kenneth J. Harrison
- 👤 Edward P. Raynes
- 👤 Frances C. Saunders
- 👤 David J. Thompson
- 👤 David F. Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:03
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/04; C09K19/06; C09K19/08; C09K19/10; C09K19/20; C09K19/30; C09K19/3001; C09K19/2007; C09K19/52; C09K19/60; C09K19/603; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
88 words
A material suitable for a guest-host liquid crystal device comprising a solution of a liquid crystal material and a pleochroic dye characterised in that the dye comprises at least one anthraquinone compound free from water-solubilising and ionic substituents and having the formula: ##STR24## wherein each of R and R 1 independently represents an n-alkyl group having from 4 to 7 carbon atoms inclusive and wherein each of R 2 and R 3 is independently selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms inclusive.
Claim 2
Dependent Claim
88 words
A material suitable for a guest-host liquid crystal device comprising a solution of a liquid crystal material and a pleochroic dye characterised in that the dye comprises at least one anthraquinone compound free from water-solubilising and ionic substituents and having the formula: ##STR24## wherein each of R and R 1 independently represents an n-alkyl group having from 4 to 7 carbon atoms inclusive and wherein each of R 2 and R 3 is independently selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms inclusive.
Claim 3
Dependent Claim
21 words
A material according to claim 1 and wherein the liquid crystal material comprises at least 90% by weight of the solution.
Claim 4
Dependent Claim
17 words
A material according to claim 1 and wherein the liquid crystal material has a positive dielectric anisotropy.
Claim 5
Dependent Claim
17 words
A material according to claim 1 and wherein the liquid crystal material has a negative dielectric anisotropy.
Claim 6
Dependent Claim
24 words
A material according to claim 1 and wherein the groups R and R 1 in Formula I specified in claim 1 are the same.
Claim 7
Dependent Claim
21 words
A material according to claim 5 and wherein the groups R 2 and R 3 in Formula I are both hydrogen.
Claim 8
Dependent Claim
17 words
A material according to claim 6 and wherein the compound of Formula I has the formula: ##STR25##
Claim 9
Dependent Claim
17 words
A material according to claim 6 and wherein the compound of Formula I has the formula: ##STR26##
Claim 10
Dependent Claim
17 words
A material according to claim 6 and wherein the compound of Formula I has the formula: ##STR27##
Claim 11
Dependent Claim
17 words
A material according to claim 6 and wherein the compound of Formula I has the formula: ##STR28##
Claim 12
Dependent Claim
23 words
A material according to claim 1 and wherein at least one of the groups R 2 and R 3 represents C 1-4 -alkyl.
Claim 13
Dependent Claim
38 words
A material according to claim 11 and wherein the groups R 1 and R 2 in Formula I are identical and are selected from n-butyl and n-hexyl, R 2 is H and R 3 is C 1-4 -alkyl.
Claim 14
Dependent Claim
27 words
A material according to claim 12 and wherein the pleochroic dye is a mixture of compounds at least one of which is as specified in claim 12.
Claim 15
Dependent Claim
56 words
A material according to claim 13 and wherein the pleochroic dye is a mixture of compounds at least one of which is of Formula I wherein R and R 1 are the same and are selected from n-butyl and n-hexyl, one of R 2 and R 3 is H and the other is C 1-4 -alkyl.
Claim 16
Dependent Claim
45 words
A material according to claim 14 and wherein the mixture also includes at least one compound of Formula I wherein R and R 1 are the same and are selected from n-butyl and n-hexyl and R 2 and R 3 are both C 1-4 -alkyl.
Claim 17
Dependent Claim
26 words
A material according to claim 14 and wherein the different compounds having Formula I both or all have the same groups R and R 1 .
Claim 18
Dependent Claim
39 words
A material according to claim 1, and wherein any compound of Formula I incorporated in the material and having R 2 or R 3 or both representing a C 1-4 -alkyl group, the C 1-4 -alkyl group is methyl.
Claim 19
Dependent Claim
29 words
A material according to claim 1 and wherein the liquid crystal material comprises a mixture of cyanobiphenyls together with a material having a clearing point greater than 80° C.
Claim 20
Dependent Claim
31 words
A material according to claim 1 and wherein the liquid crystal material comprises a mixture of cyanophenyl cyclohexane compounds together with a material having a clearing point greater than 80° C.
Claim 21
Dependent Claim
39 words
A material according to claim 1, wherein the liquid crystal material comprises a mixture of esters having the general formula: ##STR29## wherein ##STR30## is bicyclo (2,2,2) octane and ##STR31## and wherein R A and R B are alkyl substituents.
Claim 22
Dependent Claim
39 words
A material according to claim 1, wherein the liquid crystal material comprises a mixture of compounds having the formula: ##STR32## where R Q is C 2-9 n-alkyl, together with a material having a clearing point greater than 80° C.
Claim 23
Dependent Claim
38 words
A material according to claim 1 and wherein for each compound contained in the dye the product of molar extinction coefficient and the solutibility of the dye in moles per liter is at least 500 cm -1 .
Claim 24
Dependent Claim
26 words
A material according to claim 1 and wherein each compound contained in the pleochroic dye forms between 0.5 and 10 percent by weight of the material.
Claim 25
Dependent Claim
26 words
A material according to claim 1 and wherein each compound contained in the pleochroic dye forms between 0.5 and 5 percent by weight of the material.
Claim 26
Dependent Claim
37 words
A material according to claim 1 and wherein the pleochroic dye comprises a mixture of dyes of a different colour, at least one of which is a dye compound of Formula I as defined in claim 1.
Claim 27
Dependent Claim
36 words
A material according to claim 25 and wherein the pleochroic dye includes a mixture of a blue dye, a purple or red/purple dye and a yellow dye, the blue dye being a compound of Formula I.
Claim 28
Dependent Claim
21 words
A material according to claim 6 and wherein the mixture also includes any orange dye and comprises a neutral coloured mixture.
Claim 29
Dependent Claim
44 words
A material according to claim 25, and wherein the pleochroic dye comprises a neutral coloured mixture of a yellow dye, a red or purple/red dye, a blue dye and a blue/green dye, the blue dye and the blue/green dye being compounds of Formula I.
Claim 30
Dependent Claim
29 words
A material according to 28, wherein the yellow dye has the following general formula: ##STR33## wherein said formula S is sulphur and R C and R D are aryl.
Claim 31
Dependent Claim
29 words
A material according to 28, wherein the yellow dye has the following general formula: ##STR33## wherein said formula S is sulphur and R C and R D are aryl.
Claim 32
Dependent Claim
42 words
A material according to 26, wherein the dye mixture includes a red/purple dye having the following general formula: ##STR34## wherein said formula K 1 and K 2 represent alkyl groups, S is sulphur, and R A and R B represent aryl groups.
Claim 33
Dependent Claim
42 words
A material according to 26, wherein the dye mixture includes a red/purple dye having the following general formula: ##STR34## wherein said formula K 1 and K 2 represent alkyl groups, S is sulphur, and R A and R B represent aryl groups.
Claim 34
Dependent Claim
35 words
A material according to claim 1, and wherein the liquid crystal material is suitable for a cholesteric to nematic phase change effect device and comprises a nematic liquid crystal material together with a chiral agent.
Claim 35
Dependent Claim
53 words
A liquid crystal electro-optical device including two electrically insulating substrates at least one of which is optically transparent, electrodes on the inner surfaces of the substrates and a film of dielectric material contained between the substrates, wherein the improvement comprises the dielectric material being a dyed liquid crystal material according to claim 1.
Claim 36
Dependent Claim
21 words
A liquid crystal device according to claim 32 and wherein the device is a cholesteric to nematic phase change effect device.
Claim 37
Dependent Claim
17 words
A liquid crystal device according to claim 32 and wherein the device is a Freedericksz effect device.
Claim 38
Dependent Claim
18 words
A liquid crystal device according to claim 32 and wherein the device is a twisted nematic effect device.
Claim 39
Dependent Claim
89 words
A material suitable for a guest-host liquid crystal device consisting of a solution composed of a liquid crystal material and a pleochroic dye wherein said dye is at least one anthraquinone compound which compound is water-solubilizing-ionic-substituents-free, said compound having the following formula: ##STR35## wherein said formula each of R and R 1 independently represents an n-alkyl group having 4 to 7 carbon atoms inclusive and wherein each of R 2 and R 3 is independently selected from hydrogen or alkyl groups having from 1 to 4 carbon atoms inclusive.
Claim 40
Dependent Claim
89 words
A material suitable for a guest-host liquid crystal device consisting of a solution composed of a liquid crystal material and a pleochroic dye wherein said dye is at least one anthraquinone compound which compound is water-solubilizing-ionic-substituents-free, said compound having the following formula: ##STR35## wherein said formula each of R and R 1 independently represents an n-alkyl group having 4 to 7 carbon atoms inclusive and wherein each of R 2 and R 3 is independently selected from hydrogen or alkyl groups having from 1 to 4 carbon atoms inclusive.
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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) | 1988-03-25 | 1988-09-24 | 1989-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-25 | 1992-09-24 | 1993-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-25 | 1996-09-24 | 1997-03-26 | $7700.00 | Window Closed / Lapsed |