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US4299720A
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Liquid crystal mixture
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1979-11-09
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Granted: 1981-11-10
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Expires: 1999-11-09
Abstract
Abstract A liquid crystal mixture intended for electrooptical displays having no polarizers, consisting of: a nematic liquid crystal as the host phase; an optically active additive to give the host phase a cholesteric structure; and at least one pleochroic anthraquinone dye as the guest phase dissolved in the host phase, said anthraquinone dye having the formula: ##STR1## wherein R 2 , R 3 and R 4 are the same or different substituents and are selected from the group consisting of hydrogen, hydroxyl, amino, and short-chain N-monoalkylamino substituents; Y represents halogen, alkyl or alkoxy groups each with 1-16 carbon atoms, amino, alkylamino groups with 1-16 carbon atoms in the alkyl portion, nitro, or hydroxyl group; X represents halogen, amino or the group R 5 , wherein R 5 is an alkyl group with 1-18 carbon atoms, an alkyl chain with 1-18 carbon atoms that is interrupted with one or two oxy groups or a group having the formula: --(CH.sub.2).sub.p --(O--C.sub.2 H.sub.4).sub.r --O--R.sup.6 wherein p is an integer from 1 to 6, r is either zero or an integer from 1 to 6, and R 6 is an alkyl group with 1-6 carbon atoms; the symbol A represents a 5- or 6-membered aromatic, alicyclic or heterocyclic ring which may be substituted with oxo- and/or imino groups, or optionally, hydroxy and/or amino groups and indices n and m can be 0, 1 or 2.
Inventors
- 👤 Maged A. Osman
- 👤 Terry J. Scheffer
- 👤 Laszlo Revesz
- 👤 Jurgen Markert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:08
CPC Classifications
C; C09; C09K; C09K19/00; C09K19/52; C09K19/60; C09K19/603; C09B; C09B3/00; C09B3/78; C09B5/00; C09B5/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
230 words
Liquid crystal mixture intended for electro-optical displays having no polarizers, consisting of: a nematic liquid crystal as the host phase; an optically active additive to give the host phase a cholesteric structure; and at least one pleochroic anthraquinone dye as the guest phase dissolved in the host phase, said anthraquinone dye having the formula: ##STR10## wherein R 2 , R 3 and R 4 are the same or different substituents and are selected from the group consisting of hydrogen, hydroxyl, amino, and short-chain N-monoalkylamine substituents; Y represents halogen, alkyl or alkoxy groups each with 1-16 carbon atoms, amino, alkylamino groups with 1-16 carbon atoms in the alkyl portion, nitro, or hydroxyl groups; X represents halogen, amino or the group R 5 , wherein R 5 is an alkyl group with 1-18 carbon atoms, an alkyl chain with 1-18 carbon atoms that is interrupted with one or two oxy groups or a group having the formula: --(CH.sub.2).sub.p --(O--C.sub.2 H.sub.4).sub.r --O--R.sup.6 wherein p is an integer from 1 to 6, r is either zero or an integer from 1 to 6, and R 6 is an alkyl group with 1-6 carbon atoms; the symbol A represents a 5 or 6 membered aromatic, alicyclic or heterocyclic ring which may be substituted with oxo and/or imino groups or, optionally, hydroxy and/or amino groups and indices n and m can be 0, 1 or 2.
Claim 2
Dependent Claim
230 words
Liquid crystal mixture intended for electro-optical displays having no polarizers, consisting of: a nematic liquid crystal as the host phase; an optically active additive to give the host phase a cholesteric structure; and at least one pleochroic anthraquinone dye as the guest phase dissolved in the host phase, said anthraquinone dye having the formula: ##STR10## wherein R 2 , R 3 and R 4 are the same or different substituents and are selected from the group consisting of hydrogen, hydroxyl, amino, and short-chain N-monoalkylamine substituents; Y represents halogen, alkyl or alkoxy groups each with 1-16 carbon atoms, amino, alkylamino groups with 1-16 carbon atoms in the alkyl portion, nitro, or hydroxyl groups; X represents halogen, amino or the group R 5 , wherein R 5 is an alkyl group with 1-18 carbon atoms, an alkyl chain with 1-18 carbon atoms that is interrupted with one or two oxy groups or a group having the formula: --(CH.sub.2).sub.p --(O--C.sub.2 H.sub.4).sub.r --O--R.sup.6 wherein p is an integer from 1 to 6, r is either zero or an integer from 1 to 6, and R 6 is an alkyl group with 1-6 carbon atoms; the symbol A represents a 5 or 6 membered aromatic, alicyclic or heterocyclic ring which may be substituted with oxo and/or imino groups or, optionally, hydroxy and/or amino groups and indices n and m can be 0, 1 or 2.
Claim 3
Dependent Claim
41 words
The mixture of claim 1, wherein R 5 , X and m have the same meaning as recited and R 7 represents hydrogen or a short chain alkyl group, wherein ring A corresponds to a ring having the formulae (11)-(33) ##STR11##
Claim 4
Dependent Claim
25 words
The mixture of claim 2, wherein ring A is selected from the group consisting of rings of the formula (11)-(19) and R 7 represents hydrogen.
Claim 5
Dependent Claim
36 words
The mixture of claim 1, wherein R 3 is hydrogen or amino, R 4 is hydrogen, n=0, m=1, X has the same meaning as defined in claim 1 and R 2 is hydrogen, amino, or hydroxyl.
Claim 6
Dependent Claim
27 words
The mixture of claim 4, wherein R 5 is an alkyl group with 2-14 carbon atoms, or an alkyloxyalkyl group having a total of 2-14 carbon atoms.
Claim 7
Dependent Claim
25 words
The mixture of claim 1, 2, 3, 4 or 5, wherein the anthraquinone dye of formula (1) has a dichroic ratio of at least 7.
Claim 8
Dependent Claim
22 words
The mixture of claim 1, wherein dye (1) has the formula (34). ##STR12## and R 5 is as defined in claim 1.
Claim 9
Dependent Claim
22 words
The mixture of claim 1, wherein dye (1) has the formula (35) ##STR13## and R 5 is as defined in claim 1.
Claim 10
Dependent Claim
22 words
The mixture of claim 1, wherein dye (1) has the formula (36) ##STR14## and R 5 is as defined in claim 1.
Claim 11
Dependent Claim
21 words
The mixture of claim 1, wherein dye (1) has the formula (37) ##STR15## and R 5 is defined in claim 1.
Claim 12
Dependent Claim
31 words
The mixture of claim 7, 8, 9 or 10 wherein R 5 represents a straight or branched chain alkyl group with 2-14 carbon atoms, --(CH.sub.2).sub.3 OCH.sub.3, or --(CH.sub.2).sub.3 OCH.sub.2 CH(CH.sub.3)(CH.sub.2).sub.3 CH.sub.3.
Claim 13
Dependent Claim
48 words
The mixture of claim 1, wherein the mixture is composed of 80-98.5 wt. % host phase 0.5-15 wt. % optically active additive 0.1-5 wt. % anthraquinone dye and wherein the solubility of the anthraquinone dye in the host phase at normal temperatures is at least 0.5 wt. %.
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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) | 1984-11-09 | 1985-05-11 | 1985-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-09 | 1989-05-11 | 1989-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-09 | 1993-05-11 | 1993-11-10 | $7700.00 | Window Closed / Lapsed |