US5376302A
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Electrooptical liquid crystal system
Assignee: Merck Patent GmbH
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Filing: 1993-04-06
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Granted: 1994-12-27
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Expires: 2013-04-06
Abstract
Abstract The invention relates to an electrooptical liquid crystal system which between two electrode layers there is contained a liquid crystal mixture and a further optically transparent polymer medium, whose liquid crystal molecules have irregular orientation in the switched-off state, in which one of the refractive indices of the liquid crystal mixture is substantially the same as the refractive index of the medium n m and/or in which the quotient from the weight of the liquid crystal mixture and the weight of the optically transparent medium is 1.5 or more, which in one of the switching states has reduced transmission compared with the other state essentially independent of the polarization of the incident light, and whose liquid crystal mixture contains at least one dielectrically neutral and at least one dielectrically positive liquid crystalline or monotropic compound, characterized in that the liquid crystalline mixture contains less than 15% by weight of one or more dielectrically positive liquid crystalline, enantiotropic or monotropic, two-ring compounds in order to lower the solubility of the liquid crystal mixture in the medium.
Inventors
- 👤 David Coates
- 👤 Patrick Nolan
- 👤 Shirley Marden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:50
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1334; C; C09; C09K; C09K19/00; C09K19/04; C09K19/42; C09K19/52; C09K19/54; C09K19/542; C09K19/544; C09K2323/00
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
178 words
In an electrooptical liquid crystal system comprising two electrode layers between which is a liquid crystal mixture and a further optically transparent polymer medium, wherein: the liquid crystal molecules of said mixture have irregular orientation in the switched-off state, one of the refractive indices of the liquid crystal mixture is substantially the same as the refractive index of the polymer medium and/or the quotient of the weight of the liquid crystal mixture and the weight of the optically transparent medium is 1.5 or more, one of the switching states has reduced transmission compared with the other state essentially independent of polarization of incident light, and said liquid crystal mixture contains at least one dielectrically neutral and at least one dielectrically positive liquid crystalline, enantiotropic or monotropic, compound, the improvement wherein said liquid crystal mixture contains one or more dielectrically positive liquid crystalline, enantiotropic or monotropic, two-ring compounds to lower the solubility of the liquid crystal mixture in said medium, the amount of said dielectrically positive liquid crystalline, enantiotropic or monotropic, two-ring compounds being less than 15% by weight.
Claim 2
Dependent Claim
178 words
In an electrooptical liquid crystal system comprising two electrode layers between which is a liquid crystal mixture and a further optically transparent polymer medium, wherein: the liquid crystal molecules of said mixture have irregular orientation in the switched-off state, one of the refractive indices of the liquid crystal mixture is substantially the same as the refractive index of the polymer medium and/or the quotient of the weight of the liquid crystal mixture and the weight of the optically transparent medium is 1.5 or more, one of the switching states has reduced transmission compared with the other state essentially independent of polarization of incident light, and said liquid crystal mixture contains at least one dielectrically neutral and at least one dielectrically positive liquid crystalline, enantiotropic or monotropic, compound, the improvement wherein said liquid crystal mixture contains one or more dielectrically positive liquid crystalline, enantiotropic or monotropic, two-ring compounds to lower the solubility of the liquid crystal mixture in said medium, the amount of said dielectrically positive liquid crystalline, enantiotropic or monotropic, two-ring compounds being less than 15% by weight.
Claim 3
Dependent Claim
33 words
A system according to claim 1, wherein said liquid crystal mixture contains more than 25% by weight of one or more dielectrically neutral liquid crystalline, enantiotropic or monotropic, two-, three-, or four-ring compounds.
Claim 4
Dependent Claim
35 words
A system according to claim 1, wherein said liquid crystal mixture further contains more than 20% by weight of one or more dielectrically positive liquid crystalline, enantiotropic or monotropic, compounds containing three or more rings.
Claim 5
Dependent Claim
18 words
A system according to claim 1, wherein said liquid crystal mixture further contains one or more pleochroic dyes.
Claim 6
Dependent Claim
25 words
A system according to claim 1, wherein the amount of said dielectrically positive, liquid crystalline, enantiotropic or monotropic, two-ring compounds is not less than 1%.
Claim 7
Dependent Claim
104 words
A system according to claim 1, wherein said dielectrically positive, liquid crystalline two-ring compound are compounds of Formula I ##STR10## wherein: R is an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH 2 groups can be replaced by --0--, --CO--, --COO--, --OCO--, --S-- or --CH═CH=; ##STR11## is Cyc, Phe, Phe.2F, Phe.3F, Phe.2F6F, Phe.2F3F6F, Pyr, Pyd or Dio; Z is --CH 2 CH 2 --, --COO--, --OCO--, --C.tbd.C-- or a single bond; Q is CF 2 , OCF 2 , C 2 F 4 , OC 2 F 4 or a single bond; and Y is H, Cl, F or CN.
Claim 8
Dependent Claim
47 words
A system according to claim 6, wherein the dielectrically positive two-ring component is based on carbonitriles in which O is a single bond and Y is CN, and the percentage of said two-ring component is 3-15% with respect to the total mass of the liquid crystal mixture.
Claim 9
Dependent Claim
40 words
A system according to claim 1, wherein said dielectrically positive two-ring component is based on SFM (super fluorinated materials) compounds, and the percentage of said two-ring component is 7.5-15% with respect to the total mass of the liquid crystal mixture.
Claim 10
Dependent Claim
97 words
A system according to claim 2, wherein said dielectrically neutral compounds are compounds of formula II ##STR12## wherein: R 1 and R 2 in each case independently of one another, are an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH 2 groups can be replaced by --0--, --CO--, --COO--, --OCO--, --S-- or --CH═CH═; ##STR13## in each case independently of one another, are Cyc, Phe, Phe.2F, Phe.3F, Phe.2F6F, Phe.2F3F6F, Pyr, Pyd, or Dio; Z is --CH 2 CH 2 --, --COO--, --OCO--, --C.tbd.C-- or a single bond; and n is 1, 2 or 3.
Claim 11
Dependent Claim
128 words
A system according to claim 1, wherein said liquid crystal mixture further contains one or more dielectrically positive, liquid crystalline, enantiotropic or monotropic compounds having three or more rings selected from the group of compounds of formula III ##STR14## wherein: R is an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH 2 groups can be replaced by --0--, --CO--, --COO--, --OCO--, --S-- or --CH═CH═; ##STR15## is Cyc, Phe, Phe.2F, Phe.3F, Phe.2F6F, Phe.2F3F6F, Pyr, Pyd or Dio; Z is --CH 2 CH 2 --, --COO--, --OCO--, --C.tbd.C-- or a single bond; m is 1 or 2; Q is CF 2 , OCF 2 , C 2 F 4 , OC 2 F 4 or a single bond; and Y is H, Cl, F or CN.
Claim 12
Dependent Claim
28 words
A system according to claim 10, wherein the amount of said one or more dielectrically positive, liquid crystalline compounds having three or more rings is at least 20%.
Claim 13
Dependent Claim
24 words
A system according to claim 1, wherein the amount of said dielectrically positive, liquid crystalline, enantiotropic or monotropic, two-ring compounds is 3% or more.
Claim 14
Dependent Claim
13 words
A system according to claim 1, wherein said system is a network system.
Claim 15
Dependent Claim
14 words
A system according to claim 1, wherein said system is a microdroplet matrix system.
Claim 16
Dependent Claim
29 words
A system according to claim 1, wherein said transparent polymer medium has a structure between the structure of a network system and the structure of a microdroplet matrix system.
Claim 17
Dependent Claim
16 words
A system according to claim 1, wherein the thickness of the electrooptical system, d, is≦2 mm.
Claim 18
Dependent Claim
102 words
A system according to claim 6, wherein said compounds of formula I are of the following formulae: R-Cyc-Z-Cyc-Q-Y R-Cyc-Z-Phe-Q-Y R-Cyc-Z-Phe.2F-Q-Y R-Cyc-Z-Phe.3F-Q-Y R-Cyc-Z-Phe.2F6F-Q-Y R-Cyc-Z-Phe.2F3F6F-Q-Y R-Phe-Z-Phe-Q-Y R-Phe.2F-Z-Phe-Q-Y R-Phe.3F-Z-Phe-Q-Y R-Phe.2F6F-Z-Phe-Q-Y R-Phe.(F)-Z-Phe.(F)-Q-Y R-Pyr-Z-Phe.(F)-CN R-Pyd-Z-Phe.(F)-CN wherein R is an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH 2 groups can be replaced by --0--, --CO--, --COO---, --OCO--, --S-- or --CH═CH--; Z is --CH 2 CH 2 --, --COO--, --OCO--, --C.tbd.C-- or a single bond; Q is CF 2 , OCF 2 , C 2 F 4 , OC 2 F 4 or a single bond; and Y is H, Cl, F or CN.
Claim 19
Dependent Claim
20 words
A system according to claim 17, wherein Z is --CH 2 CH 2 --, --COO--, --OCO-- or a single bond.
Claim 20
Dependent Claim
32 words
A system according to claim 7, wherein said system contains at least one two-ring carbonitrile compound according to formula I, wherein R is an alkoxy group with 5 or more C atoms.
Claim 21
Dependent Claim
33 words
A system according to claim 8, wherein, in said SFM compounds, Q is CF 2 , OCF 2 , C 2 F 4 or a single bond; and Y is Cl or F.
Claim 22
Dependent Claim
28 words
A system according to claim 8, wherein, in said SFM compounds, Q is CF 2 , OCF 2 or C 2 F 4 ; and Y is H.
Claim 23
Dependent Claim
21 words
A system according to claim 8, wherein, in said SFM compounds, Q-Y is F, Cl, CF 3 or OCF 3 .
Claim 24
Dependent Claim
30 words
A system according to claim 1, wherein said liquid-crystalline mixture further contains 0.1-20 wt. %, based on the total weight of the liquid-crystalline mixture, of one or more pleochroic dyes.
Claim 25
Dependent Claim
128 words
A system according to claim 9, wherein said liquid crystal mixture further contains one or more dielectrically positive, liquid crystalline, enantiotropic or monotropic compounds having three or more rings selected from the group of compounds of formula III ##STR16## wherein R is an alkyl group with 1-15 C atoms, wherein one or more non-adjacent CH 2 groups can be replaced by --0--, --CO--, --COO--, --OCO--, --S-- or --CH═CH--; ##STR17## is Cyc, Phe, Phe.2F, Phe.3F, Phe.2F6F, Phe.2F3F6F, Pyr, Pyd or Dio; Z is --CH 2 CH 2 --, --COO--, --OCO--, --C.tbd.C-- or a single bond; m is 1 or 2; Q is CF 2 , OCF 2 , C 2 F 4 , OC 2 F 4 or a single bond; and Y is H, Cl, F or CN.
Claim 26
Dependent Claim
28 words
A system according to claim 24, wherein the amount of said one or more dielectrically positive, liquid crystalline compounds having three or more rings is at least 20%.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |