LIQUID-CRYSTALLINE MEDIUM

Abstract

Liquid-crystalline (LC) media having positive dielectric anisotropy and liquid-crystal displays (LCDs) containing these media, especially displays addressed by an active matrix and in particular energy efficient LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA type. The media have an improved long-term stability against UV radiation and elevated temperatures.

Claims

1. A liquid-crystalline medium, comprising two or more compounds of Formula I ##STR00569## in which the individual substituents have the following meanings: R.sup.1 and R.sup.2 each, independently of one another, a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00570## O, CO or OCO in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, A.sup.0, A.sup.1, A.sup.2 each, independently of one another, denote phenylene-1,4-diyl, in which, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH.sub.3, CHF.sub.2, CH.sub.2F, CF.sub.3, OCH.sub.3, OCHF.sub.2 or OCF.sub.3, cyclohexane-1,4-diyl, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced, independently of one another, by O and/or S and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, Z.sup.1 and Z.sup.2 each, independently of one another, denote CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, COO, OCO, C.sub.2H.sub.4, C.sub.2F.sub.4, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, CFHCFH, CFHCH.sub.2, CH.sub.2CFH, CF.sub.2CFH, CFHCF.sub.2, CHCH, CFCH, CHCF, CFCF, CC or a single bond, k and l each, independently of one another, denote 0, 1, 2 or 3; and and one or more compounds of the Formula H ##STR00571## in which R.sup.11 each, independently of one another, denotes a H atom, F, an alkyl group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and one or, if present, a plurality of CH.sub.2 groups may be replaced by CHCH or CC, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, R.sup.12 each, independently of one another, denotes a H atom, an alkyl group having 1 to 20 C atoms, in which one CH.sub.2 group or a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, a hydrocarbon radical which contains a cycloalkyl or alkylcycloalkyl unit and in which one CH.sub.2 group or a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, or an aromatic or heteroaromatic hydrocarbon radical, in which one H atom or a plurality of H atoms may be replaced by OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, R.sup.13 and R.sup.14 each, independently of one another, denotes an alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxylic acid radical having 6 to 12 C atoms, R.sup.15 each, independently of one another, denotes an alkyl group having 1 to 10 C atoms, in which one CH.sub.2 group or a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, R.sup.16 each, independently of one another a H atom, an alkyl group or an alkoxy group having 1 to 10 C atoms, O-cycloalkyl group having 3 to 12 C atoms, O.Math. or OH, S.sup.11 and S.sup.12 each, independently of one another, denote an alkylene group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, or denote a single bond, Y.sup.11 to Y.sup.14 each, independently of one another, denote methyl or ethyl, X.sup.11 denotes C, Z.sup.11 to Z.sup.14 each, independently of one another, denote O, (CO), O(CO), (CO)O, O(CO)O, (NR.sup.13), NR.sup.13(CO) or a single bond if S.sup.11 is a single bond, both Z.sup.11 and Z.sup.12 do not simultaneously denote O; if S.sup.12 is a single bond, both Z.sup.13 and Z.sup.14 do not simultaneously denote O; and, if q denotes 0, both Z.sup.12 and Z.sup.13 do not simultaneously denote O, p denotes 1 or 2, q denotes 0 or 1, o denotes (3-p), n denotes an integer from 1 to 10, m denotes an integer from 0 to 8, wherein n*p denotes an integer from 1 to 10, preferably from 3 to 8, and ##STR00572## denotes an organic moiety having (m+n) bonding sites.

2. The liquid-crystalline medium according to claim 1, wherein in the Formula I k denotes 1, l denotes 0, and A.sup.0 denotes ##STR00573##

3. The liquid-crystalline medium according to claim 1, wherein the compounds of Formula I are selected from the group consisting of the following compounds: ##STR00574## in which L.sup.1 to L.sup.6 each, independently from one another, denote a H atom, F, Cl, or an alkyl group having 1 to 4 C atoms.

4. The liquid-crystalline medium according to claim 1, wherein the one or more compounds of the Formula H are selected from the group consisting of the compounds the following formulae: ##STR00575## ##STR00576## in which R.sup.11 each, independently of one another, denotes an H atom, an alkyl group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and one or, if present, a plurality of CH.sub.2 groups may be replaced by CHCH or CC, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15 R.sup.16 denotes a H atom or O.sup., n denotes an integer from 0 to 8, and S.sup.11 and S.sup.12 each, independently of one another, denote an alkylene group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, or denote a single bond.

5. The liquid-crystalline medium according to claim 1, wherein the one or more compounds of formula H are selected from the following compounds: ##STR00577## ##STR00578##

6. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the following formulae: ##STR00579## in which alkyl and alkyl* denotes C.sub.1-6-alkyl, alkenyl and alkenyl* each, independently of one another, denote C.sub.2-6-alkenyl, X.sup.0 F, Cl, CN, SF.sub.5, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms, L denotes H or F, and R denotes C.sub.1-6-alkyl, C.sub.1-6-alkoxy or C.sub.2-6-alkenyl.

7. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00580## in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning: ##STR00581## R.sup.1, R.sup.2 each, independently of one another, a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2, OCF.sub.2, CHCH, ##STR00582## O, COO or OCO in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, R.sup.3 one of the meanings given for R.sup.1, or X.sup.1, X.sup.1 fluorinated alkyl or alkoxy with 1, 2 or 3 C atoms, Z.sup.x, Z.sup.y CH.sub.2CH.sub.2, CHCH, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, COO, OCO, C.sub.2F.sub.4, CFCF, CHCHCH.sub.2O, or a single bond, Z.sup.z CH.sub.2O or a single bond, Y.sup.1 O or S, L.sup.1-4 H, F or Cl, x, y 0, 1 or 2, with x+y3, z 0 or 1, wherein in formula B the dibenzofuran or dibenzothiophene group may also be further substituted by a methyl or methoxy group, and wherein the compounds of formula Y contain at least one substituent L.sup.1-4 that is F or Cl.

8. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00583## wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings ##STR00584## R.sup.0 each, independently of one another, a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2, OCF.sub.2, CHCH, ##STR00585## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, X.sup.0 F, Cl, CN, SF.sub.5, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms, and Y.sup.1-6 H or F, Y.sup.0 H or CH.sub.3.

9. The liquid-crystalline medium according to claim 8, wherein the one or more compounds of formula II are selected from the following sub-formulae: ##STR00586##

10. The liquid-crystalline medium according to claim 8, wherein the one or more compounds of formula III are selected from the following sub-formulae: ##STR00587## ##STR00588## ##STR00589##

11. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00590## in which R.sup.0 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00591## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, X.sup.0 is F, Cl, CN, SF, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms, Y.sup.1-5 are independently H or F, and Z.sup.0 denotes C.sub.2H.sub.4, (CH.sub.2).sub.4, CHCH, CFCF, C.sub.2F.sub.4, CH.sub.2CF.sub.2, CF.sub.2CH.sub.2, CH.sub.2O, OCH.sub.2, COO or OCF.sub.2, in formulae V and VI also a single bond, in formulae V and VIII also CF.sub.2O, r denotes 0 or 1, and s denotes 0 or 1.

12. The liquid-crystalline medium according to claim 1, further comprising one or more compounds of the formula XIV ##STR00592## in which R.sup.1 and R.sup.2 each, independently of one another, denote n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

13. The liquid-crystalline medium according to claim 1, further comprising one or more compounds of the formula XVI ##STR00593## in which L.sup.1 is H, F or Cl, and R.sup.1 and R.sup.2 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00594## O, COO or OCO in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom.

14. The liquid-crystalline medium according to one or more of claims 1 to 13, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00595## in which L.sup.1 is H, F, or Cl, and R.sup.1 and R.sup.2 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00596## O, COO or OCO in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom.

15. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00597## in which R.sup.0 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00598## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom Y.sup.1-5 are independently H or F, and X.sup.0 each, independently of one another, is F, Cl, CN, SF.sub.5, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms.

16. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00599## in which ##STR00600## and R.sup.1 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00601## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, and X.sup.0 is F, Cl, CN, SF, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms.

17. The liquid-crystalline medium according to claim 1, further comprising one or more compounds selected from the group consisting of the following formulae ##STR00602## in which L.sup.1 H, F or Cl, R.sup.1 and R.sup.2 each, independently of one another, is a H atom, an alkyl or an alkoxy group having 1 to 12 C atoms or an alkenyl or an alkenyloxy group having 2 or 12 C atoms in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00603## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom.

18. (canceled)

19. The liquid-crystalline medium according to claim 1, further comprising one or more polymerizable compounds.

20. A process for the preparation of a liquid-crystalline medium according to claim 1, comprising the steps of mixing two or more compounds of the formula I and one or more compounds of the formula H with one or more mesogenic compounds and optionally with one or more polymerizable compounds and/or one or more additives.

21. (canceled)

22. An electro-optical liquid-crystal display comprising a liquid-crystalline medium according to claim 1.

23. The electro-optical liquid-crystal display according to claim 22, comprising a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA display.

24. The electro-optical liquid-crystal display according to claim 22, comprising an FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, IPS or PS-IPS display.

Description

DETAILED DESCRIPTION OF THE INVENTION

Compounds of Formula I

[0065] Preference is given to LC media comprising the compounds of Formula I in which A.sup.0 denotes phenylene-1,4-diyl, in which, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH.sub.3, CHF.sub.2, CH.sub.2F, OCH.sub.3, OCHF.sub.2, CF.sub.3 or OCF.sub.3. Particularly preferred are compounds in which A.sup.0 denotes

##STR00012##

and very particularly preferably in which

##STR00013##

[0066] The preferred compounds of the Formula I result in media having a particularly high clearing point, low rotational viscosity, a broad nematic phase, high birefringence and an excellent thermal and UV stability.

[0067] Preference is furthermore given to compounds of the Formula I in which m and n denote 0, 1 or 2, particularly preferably 0 or 1. Particular preference is given to compounds of the Formula I in which n denotes 0, i.e. the thiophene ring is a terminal ring. Preference is furthermore given to compounds of the Formula I in which m denotes 0, 1 or 2, preferably 1 or 2 and very particularly preferably 1. [0068] A.sup.1 and A.sup.2 in formula I particularly preferably denote phenylene-1,4-diyl, which may also be mono- or polysubstituted by F, furthermore cyclohexane-1,4-diyl, cyclo-hexenylene-1,4-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl. [0069] Z.sup.1 and Z.sup.2 in formula I particularly preferably denote CF.sub.2O, OCF.sub.2 or a single bond, wherein a single bond is particularly preferred. [0070] A.sup.1 and A.sup.2 in Formula I particularly preferably denote

##STR00014## [0071] preferably unsubstituted 1,4-phenylene, in which L denotes halogen, CF.sub.3 or CN, preferably F.

[0072] Preference is furthermore given to compounds of the Formula I in which R.sup.1 and R.sup.2 each, independently of one another, denote H, F, Cl, Br, CN, SCN, NCS, SF.sub.5, halogen, or alkyl, alkenyl or alkynyl having 1 to 8, preferably 1 to 5, C atoms, each of which is optionally substituted by halogen, in particular by F.

[0073] Particularly preferred radicals R.sup.1 and R.sup.2 in Formula I denote H, halogen, or alkyl, alkenyl, alkynyl or alkoxy having 1 to 12, preferably 1 to 8, C atoms, each of which is optionally substituted by halogen, in particular by F, particularly preferred are H, F, alkyl, alkenyl or alkynyl having 1 to 8 C atoms. Preferably, at least one radical is not H, particularly preferably both radicals R.sup.1 and R.sup.2 are not H. R.sup.1 is very particularly preferably equal to alkyl. R.sup.2 is furthermore preferably H, alkyl or fluorine. Very particularly preferably, R.sup.1 is alkyl and R.sup.2 is H or alkyl. R.sup.1, R.sup.2 each, independently of one another, very particularly preferably denote unbranched alkyl having 1 to 5 C atoms. If R.sup.1 and R.sup.2 denote substituted alkyl, alkoxy, alkenyl or alkynyl, the total number of C atoms in the two groups R.sup.1 and R.sup.2 is preferably less than 10.

[0074] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl.

[0075] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl and pentenyl.

[0076] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl and octynyl.

[0077] Preferred alkoxy groups are, for example, methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy.

[0078] Halogen preferably denotes F or Cl.

[0079] Particularly preferred compounds of the Formula I are those selected from the following sub-formulae:

##STR00015## [0080] in which R.sup.1 and R.sup.2 have the meanings indicated in general Formula I, and L.sup.1 to L.sup.6 independently denote H or F. R.sup.1 and R.sup.2 therein preferably denote optionally fluorinated alkyl or alkoxy having 1 to 12 C atoms, optionally fluorinated alkenyl or alkynyl having 2 to 12 C atoms, optionally fluorinated cycloalkyl having 3 to 12 C atoms.

[0081] Particularly preferred are optionally fluorinated alkyl, alkenyl or alkynyl having 1 to 5 C atoms. L.sup.2 in the Formulae 1-1-1 to 1-1-6 preferably denotes F. In the Formulae I-1-4 to 1-1-6, L.sup.3 and L.sup.4 preferably denote H. In the Formulae 1-1-4 to 1-1-6 L.sup.3 and L.sup.4 preferably denote F.

[0082] In a particularly preferred embodiment, the compounds of Formula I are selected from the following structures:

##STR00016## [0083] where R.sup.1 has the same meaning as in the general Formula I and [0084] R.sup.2 denotes a straight-chain or branched alkyl or alkoxy group having 1 to 7 C atoms, or an alkenyl, alkenyloxy, alkoxyalkyl group having 1 to 7 C atoms, or a cycloalkyl or a cycloalkoxy group having 3 to 12 C atoms, in which one or more non-adjacent CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH,

##STR00017##

O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom, in which one or more H atoms may be replaced by a halogen atom.

[0085] LC media according to the invention having a particularly high long-term stability against UV radiation and elevated temperatures and a low rotational viscosity are obtainable with the following compounds of the general Formula I:

##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##

##STR00024## [0086] wherein R.sup.1 and R.sup.2 are as defined above.

[0087] Additionally, LC media comprising the following compounds of Formula I are particularly preferred:

##STR00025## ##STR00026## ##STR00027##

[0088] Mostly preferred compounds of Formula I include, in particular, one or more of the following:

##STR00028##

[0089] As a further possibility, the following compounds of Formula I can be used:

##STR00029## ##STR00030##

[0090] The compounds of the Formula I can be prepared analogously to processes known to the person skilled in the art and described in standard works of organic chemistry, such as, for example, in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart.

Compounds of Formula H

[0091] In some preferred embodiments of the present invention, in the compounds of the formula H,

##STR00031##

denotes

##STR00032##

##STR00033##

denotes

##STR00034##

##STR00035##

denotes (CH.sub.2).sub.2, (CH.sub.2).sub.3, (CH.sub.2).sub.4, (CH.sub.2).sub.5, (CH.sub.2).sub.6, (CH.sub.2).sub.7, (CH.sub.2).sub.8, i.e. ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl,

##STR00036## [0092] wherein [0093] Z.sup.12S.sup.11Z.sup.11 on each occurrence, independently of one another, denotes O, S.sup.11O, OS.sup.11O, (CO)OS.sup.11O, O(CO)S.sup.11O, O(CO)S.sup.11(CO)O, OS.sup.11(CO)O, (CO)OS.sup.11C, (CO)OS.sup.11O(CO) or (NR.sup.13)S.sup.11O, (NR.sup.13C(O)S.sup.11(CO)O or a single bond, preferably O, S.sup.11O, OS.sup.11O, (CO)OS.sup.11O, O(CO)S.sup.11O or S.sup.11(CO)O, and/or [0094] S.sup.11 preferably denotes an alkylene group having 1 to 20 C atoms, and/or [0095] R.sup.11 if present, denotes alkyl, alkoxy or H, preferably H or alkyl, and/or [0096] R.sup.12 denotes H, methyl, ethyl, propyl, isopropyl or 3-heptyl, or cyclohexyl.

[0097] In a preferred embodiment of the present application, in the compounds of the formula H,

##STR00037##

denotes a group selected from the group of the formulae

##STR00038##

[0098] In a further preferred embodiment of the present application, in the compounds of the formula H,

##STR00039##

denotes a group selected from the group of the formulae

##STR00040##

[0099] In yet a further preferred embodiment of the present invention, in the compounds of the formula H in which p preferably denotes 1,

##STR00041##

denotes

##STR00042##

preferably OS.sup.11O, S.sup.11O or OS.sup.11, particularly preferably OS.sup.11O or S.sup.11O.

[0100] In a further preferred embodiment of the present invention, in the compounds of the formula H, the group

##STR00043##

denotes a group selected from the group of the formulae

##STR00044##

[0101] In a further preferred embodiment of the present invention in which p is 2, which may be identical to or different from those described above, in the compounds of the formula H,

##STR00045##

denotes a group selected from the group of the formulae

##STR00046##

[0102] In yet a further preferred embodiment of the present invention, which may be identical to or different from those described above, in the compounds of the formula H, the group

##STR00047## [0103] on each occurrence, independently of one another, denotes

##STR00048## [0104] preferably

##STR00049##

[0105] Compounds of the following general Formulae H-1-1, H-1-2 and H-1-3, showed to be particularly efficient UV stabilisers in liquid-crystal mixtures, in particular, in terms of VHR stability:

##STR00050## [0106] wherein ZG, R.sup.16 and n are as defined above and n denotes an integer from 1 to 8. These compounds are highly suitable as stabilisers in liquid-crystal mixtures and stabilise the VHR of the mixtures upon a UV exposure.

[0107] In a particularly preferred embodiment, the one or more compounds of the Formula H may be selected from the group consisting of the compounds the following Formulae H-2-1 to H-2-6:

##STR00051## ##STR00052## [0108] in which [0109] R.sup.11 each, independently of one another, denotes an H atom, an alkyl group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and one or, if present, a plurality of CH.sub.2 groups may be replaced by CHCH or CC, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, [0110] R.sup.16 denotes a H atom or O*, [0111] n denotes an integer from 0 to 12, and [0112] S.sup.11 and S.sup.12 each, independently of one another, denote an alkylene group having 1 to 20 C atoms, in which one CH.sub.2 group or, if present, a plurality of CH.sub.2 groups may be replaced by O or C(O), but two adjacent CH.sub.2 groups cannot be replaced by O, and in which one H atom or a plurality of H atoms may be replaced by F, OR.sup.13, N(R.sup.13)(R.sup.14) or R.sup.15, or denote a single bond.

[0113] In a preferred embodiment of the present invention, the media according to the invention comprise in each case one or more compounds of the Formula H selected from the following group of the compounds of the formulae

##STR00053## ##STR00054## ##STR00055## ##STR00056##

##STR00057## ##STR00058## ##STR00059##

[0114] Preferred content of the one or more compounds of Formula H in the LC medium depends inter alia on the inherent chemical stability of the LC medium as well as on the nature of the compound of Formula H. Compounds of Formula H in which R.sup.16 denotes O.Math., which are known as NO radical type HALS are preferably used in proportion ranging from 50 ppm to 1000 ppm, based on the weight of the LC medium. Compounds of Formula H in which R.sup.16 denotes a H atom, which are known as NH radical type HALS are advantageously used in proportion ranging from 50 ppm to 2000 ppm, based on the weight of the LC medium.

Further Mesogenic Components

[0115] Preferably, the medium contains, in addition to the compounds of Formula I and H, one or more compounds selected from the following formulae:

##STR00060## [0116] wherein [0117] alkyl and alkyl* are, independently from one another, C.sub.1-6-alkyl, and preferably denotes ethyl, propyl, butyl or pentyl, very preferably ethyl, propyl or butyl alkenyl and alkenyl* preferably denote C.sub.2-6-alkenyl. Very preferred are compounds of Formula Z1 and Z2.

[0118] Preferred compounds of Formula Z1 to Z6 are those selected from the following subformulae

##STR00061## ##STR00062##

[0119] In another preferred embodiment, the medium contains one or more compounds of Formula Z1 or its preferred subformulae and/or one or more compounds selected from Formulae Z2, Z3, Z4 and Z5 or their preferred subformulae.

[0120] Preferably, the total proportion of compounds of Formula Z1, Z2, Z3, Z4, Z5 and Z6 or their subformulae, such as CC-3-V in the medium is from 10 to 65%, very preferably from 20 to 60%, most preferably from 25 to 55% by weight. In yet a more preferred embodiment, the compound of Formula Z1-1 is used in concentrations ranging from 10 wt.-% to 60 wt.-%, more preferably 10 wt.-% to 40 wt.-%, based on the total weight of the LC medium.

[0121] Preferably, the medium contains 1, 2 or 3 compounds selected from the Formulae Z1, Z2, Z3 and Z4 or their subformulae.

[0122] The medium may additionally comprise one or more compounds of the following general formulae:

##STR00063## [0123] in which [0124] R denotes C.sub.1-6-alkyl, C.sub.1-6-alkoxy or C.sub.2-6-alkenyl, and [0125] alkenyl denotes C.sub.2-6-alkenyl,

[0126] The compounds of the formulae XII are preferably selected from the following subformulae:

##STR00064##

wherein alkyl is methyl, butyl, pentyl or hexyl.

[0127] Particular preference is given to the compounds of the formulae XIIa. In the Formula XIIb, alkyl preferably, independently of one another, denotes n-C.sub.3H.sub.7, n-C.sub.4H.sub.9 or n-C.sub.5H.sub.11, in particular n-C.sub.3H.sub.7.

[0128] Preferred compounds of subformula XIIa are selected from the following group:

##STR00065##

[0129] The medium may additionally comprise one or more compounds selected from the following formulae:

##STR00066##

in which L.sup.1 and L.sup.2 have the meanings indicated in Formula I, and R.sup.1 and R.sup.2 each, independently of one another, denote n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms; in the compound of the Formula XIV, at least one of the radicals R.sup.1 and R.sup.2 preferably denotes alkenyl having 2 to 6 C atoms.

[0130] The medium may further comprise one or more compounds of the Formula XIV in which at least one of the radicals R.sup.1 and R.sup.2 denotes alkenyl having 2 to 6 C atoms, preferably those selected from the following subformulae:

##STR00067##

in which alkyl has the meaning indicated above, and preferably denotes methyl, ethyl or propyl.

[0131] The compounds of the formulae XIV are preferably selected from the following subformulae:

##STR00068##

[0132] Very preferred are compounds of Formula XIVd1.

[0133] In yet a further embodiment the medium comprises one or more compounds of the Formula XVI

##STR00069##

in which R.sup.1 and R.sup.2 have the meanings indicated in Formula I, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H or F.

[0134] Particularly preferred compounds of the Formula XVI are those of the subformulae

##STR00070## [0135] in which [0136] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and [0137] alkenyl and alkenyl*each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH.sub.2=CHC.sub.2H.sub.4, CH.sub.3CHCHC.sub.2H.sub.4, CH.sub.2=CH and CH.sub.3CHCH.

[0138] Particular preference is given to the compounds of the formulae XVIb and XVIc. Very particular preference is given to the compounds of the following subformulae

##STR00071##

[0139] Very preferred are compounds of Formula XVIc2.

[0140] The medium comprises one or more compounds of the following formulae:

##STR00072## [0141] in which [0142] R.sup.1 and R.sup.2 have the meanings indicated in Formula I, respectively, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms. L denotes H or F.

[0143] Very preferred are compounds of Formula XVIIa wherein L is H. Very preferred are compounds of Formula XVIIb wherein L is F.

[0144] In one preferred embodiment according to the present invention, the LC medium contains, in addition to the compounds of Formula I and H, one or more compounds selected from the formulae Y and B

##STR00073## [0145] in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meanings:

##STR00074## ##STR00075## [0146] R.sup.1, R.sup.2 one of the meanings given for R.sup.1 and R.sup.2 in Formula I, [0147] R.sup.3 one of the meanings given for R.sup.1, [0148] Z.sup.x, Z.sup.y CH.sub.2CH.sub.2, CHCH, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, COO, OCO, C.sub.2F.sub.4, CFCF, CHCHCH.sub.2O, or a single bond, preferably a single bond, [0149] Z.sup.z CH.sub.2O or a single bond, [0150] Y.sup.1 O or S, [0151] L.sup.1-4 H, F or Cl, preferably H or F, very preferably F, [0152] x, y 0, 1 or 2, with x+y3, [0153] z 0 or 1, [0154] wherein in Formula B the dibenzofuran or dibenzothiophene group may also be further substituted by a methyl or methoxy group, and [0155] wherein the compounds of Formula Y contain at least one substituent L.sup.1-4 that is F or Cl, preferably F.

[0156] Preferably, the LC medium according to this first preferred embodiment contains one or more compounds of Formula I and H, one or more compounds selected from formulae Z1, Z2 and Z3, and one or more compounds selected from formulae Y and B.

[0157] The LC media according to this first preferred embodiment are especially suitable for use in LC displays of the HB-FFS or PS-HB-FFS mode.

[0158] In a second preferred embodiment according to the present invention, the LC medium does not contain a compound of the formulae Y or B.

[0159] In the compounds of Formula Y and its subformulae, R.sup.1 and R.sup.2 preferably denote straight-chain alkyl or alkoxy having 1 to 6 C atoms, furthermore alkenyl having 2 to 6 C atoms, in particular vinyl, 1E-propenyl, 1E-butenyl, 3-butenyl, 1E-pentenyl, 3E-pentenyl or 4-pentenyl.

[0160] In the compounds of Formula Y and its subformulae, preferably both radicals L.sup.1 and L.sup.2 denote F. In another preferred embodiment of the present invention, in the compounds of Formula Y and its subformulae one of the radicals L.sup.1 and L.sup.2 denotes F and the other denotes Cl.

[0161] In a preferred embodiment of the present invention, the medium contains one or more compounds of Formula Y selected from the following subformulae

##STR00076## [0162] wherein L.sup.1, L.sup.2, R.sup.1, R.sup.2, Z.sup.x, Z.sup.y, x and y have the meanings given in Formula Y or one of the preferred meanings given above in Formula I, [0163] a denotes 1 or 2, [0164] b denotes 0 or 1,

##STR00077##

denotes

##STR00078## [0165] L.sup.3, L.sup.4 denote F or Cl, preferably F, and [0166] L.sup.5 denotes a H atom or CH.sub.3.

[0167] Preferably, in the compounds of Formula Y1 and Y2 both L.sup.1 and L.sup.2 denote F or one of L.sup.1 and L.sup.2 denotes F and the other denotes Cl, or both L.sup.3 and L.sup.4 denote F or one of L.sup.3 and L.sup.4 denotes F and the other denotes Cl.

[0168] Preferably, the medium comprises one or more compounds of the Formula Y1 selected from the group consisting of the following subformulae

##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084##

##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089##

##STR00090## ##STR00091## [0169] in which [0170] a denotes 1 or 2, [0171] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, [0172] alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and L.sup.5 denotes a H atom or CH.sub.3. [0173] alkenyl preferably denotes CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.

[0174] Very preferably, the medium contains one or more compounds of Formula Y1 selected from formulae Y1-1, Y1-2, Y1-7, Y1-12, Y1-17, Y1-22, Y1-40, Y1-41, Y1-42, Y1-44, Y1-50 and Y1-68. L.sup.5 preferably denotes a H atom.

[0175] Further preferably, the medium comprises one or more compounds of the Formula Y2 selected from the group consisting of the following subformulae:

##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098##

##STR00099## [0176] in which [0177] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, and [0178] alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) denotes an oxygen atom or a single bond, and [0179] L.sup.5 denotes a H atom or CH.sub.3, preferably a H atom. [0180] alkenyl preferably denotes CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.

[0181] Very preferably, the medium contains one or more compounds of Formula Y2 selected from formulae Y2-2 and Y2-10.

[0182] The proportion of the compounds of Formula Y1 or its subformulae in the medium is preferably from 0 to 10% by weight.

[0183] The proportion of the compounds of Formula Y2 or its subformulae in the medium is preferably from 0 to 10% by weight.

[0184] The total proportion of the compounds of Formula Y1 and Y2 or their subformulae in the medium is preferably from 1 to 20%, very preferably from 2 to 15% by weight.

[0185] Preferably, the medium contains 1, 2 or 3 compounds of Formula Y1 and Y2 or their subformulae, very preferably selected from formulae Y1-2, Y1-22, Y1-66, Y1-70, Y2-6 and Y2-22.

[0186] In another preferred embodiment of the present invention, the medium contains one or more compounds of Formula Y selected from the following subformula

##STR00100##

wherein L.sup.1, L.sup.2, R.sup.1 and R.sup.2 have one of the meanings given in Formula Y or one of the preferred meanings as given in Formulae I and its subformulae.

[0187] Preferred compounds of the Formula Y3 are selected from the group consisting of the following subformulae:

##STR00101## ##STR00102## [0188] in which, [0189] 0.5 Alkyl and Alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, [0190] Alkenyl and Alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms, and [0191] O denotes an oxygen atom or a single bond. [0192] Alkenyl and Alkenyl* preferably denote CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.

[0193] Particularly preferred compounds of the Formula Y3 are selected from the group consisting of following subformulae:

##STR00103## [0194] wherein Alkoxy and Alkoxy* each, independently of one another, preferably denote straight-chain alkoxy with 3, 4, or 5 C atoms.

[0195] Preferably, in the compounds of Formula Y3 and its subformulae both L.sup.1 and L.sup.2 denote F. Further preferably in the compounds of Formula Y3 one of the radicals L.sup.1 and L.sup.2 denotes F and the other denotes Cl.

[0196] The proportion of the compounds of Formula Y3 or its subformulae in the medium is preferably from 1 to 10%, very preferably from 1 to 6% by weight.

[0197] Preferably, the medium contains 1, 2 or 3 compounds of Formula Y3 or its subformulae, preferably of Formula Y3-6, very preferably of Formula Y3-6A.

[0198] In another preferred embodiment the present invention, the medium contains one or more compounds of Formula Y selected from the subformula Y4

##STR00104## [0199] in which R.sup.1 and R.sup.2 each, independently of one another, have one of the meanings indicated above in Formula Y, and

##STR00105## [0200] each, independently of one another, denote

##STR00106## [0201] in which L.sup.5 denotes F or Cl, preferably F, and L.sup.6 denotes F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F or CHF.sub.2, preferably F, and preferably at least one of the rings G, I and K is different from unsubstituted benzene.

[0202] Preferred compounds of the Formula Y4 are selected from the group consisting of the following subformulae:

##STR00107## ##STR00108## ##STR00109## [0203] in which [0204] R denotes a straight-chain alkyl or alkoxy radical having 1-7 C atoms, [0205] R* denotes a straight-chain alkenyl radical having 2-7 C atoms, [0206] (O) denotes an oxygen atom or a single bond, and m denotes an integer from 1 to 6.

[0207] R* preferably denotes CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.

[0208] R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

[0209] The proportion of the compounds of Formula Y4 or its subformulae in the medium is preferably from 1 to 10%, very preferably from 1 to 6% by weight.

[0210] Particularly preferred compounds are those of the subformulae

##STR00110## [0211] in which [0212] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, in particular ethyl, propyl or pentyl.

[0213] Use of the following compounds is particularly advantageous:

##STR00111##

[0214] In another preferred embodiment the present invention, the medium contains one or more compounds of Formula Y selected from the group consisting of the following subformulae

##STR00112## [0215] in which R.sup.5 has one of the meanings indicated above in Formula Y for R.sup.1, alkyl denotes a straight-chain alkyl radical having 1 to 6 C atoms, L.sup.x denotes H or F, X denotes F, Cl, OCF.sub.3, OCHF.sub.2 or OCHCF.sub.2, d denotes 0 or 1, and z and m each, independently of one another, denote an integer from 1 to 6.

[0216] R.sup.5 in these compounds is particularly preferably C.sub.2-6-alkyl or -alkoxy or C.sub.2-6-alkenyl, d is preferably 1. X in these compounds is particularly preferably F. The LC medium according to the invention preferably comprises one or more compounds of the above-mentioned formulae in amounts of 5% by weight.

[0217] In the compounds of Formula B and its subformulae, R.sup.1 and R.sup.3 preferably denote straight-chain alkyl or alkoxy having 1 to 6 C atoms, in particular methoxy, ethoxy, propoxy or butoxy, furthermore alkenyl having 2 to 6 C atoms, in particular vinyl, 1E-propenyl, 1E-butenyl, 3-butenyl, 1E-pentenyl, 3E-pentenyl or 4-pentenyl.

[0218] In a preferred embodiment of the present invention, the medium contains one or more compounds of Formula B selected from the following subformulae

##STR00113## [0219] wherein L.sup.1, L.sup.2, R.sup.1 and R.sup.3 have the meanings given in Formula B.

[0220] Preferred compounds of Formula B1 are selected from the following subformulae:

##STR00114##

wherein R.sup.1 and R.sup.3 independently denote a straight-chain alkyl radical having 1 to 6 C atoms, in which one or more CH.sub.2 groups are optionally substituted by CC, CF.sub.2O, OCF.sub.2, CHCH,

##STR00115##

[0221] 0, O, COO or OCO in such a way that 0 atoms are not linked directly to one another, and in which one or more H atoms may be replaced by a halogen atom. Very preferred are compounds of Formula B1-1 and B1-2 wherein both groups (0) denote an oxygen atom and R.sup.1 and R.sup.3 independently denote an alkyl group being methyl, ethyl, propyl, butyl, pentyl or hexyl, which are preferably straight-chained. Very preferably, one alkyl is ethyl and the other alkyl is n-pentyl.

[0222] Very preferred are compounds of Formula B1-2.

[0223] Preferably, the compounds of the Formula B1-1 are selected from the group of compounds of formulae B1-1-1 to B1-1-11, preferably of Formula B1-1-6,

##STR00116## [0224] in which [0225] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, [0226] alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms, [0227] alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1 to 6 C atoms.

[0228] Preferably, the compounds of the Formula B1-2 are selected from the group of compounds of formulae B1-2-1 to B1-2-10, preferably of Formula B1-2-6,

##STR00117## [0229] in which [0230] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, [0231] alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms, [0232] alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1 to 6 C atoms.

[0233] Optionally the medium comprises one or more compounds of the Formula B1-1A and/or B1-2A

##STR00118## [0234] in which [0235] (O) denotes 0 or a single bond, [0236] R.sup.IIIA denotes alkyl or alkenyl having up to 7 C atoms or a group Cy-C.sub.mH.sub.2m+1, m and n are, identically or differently, 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, [0237] Cy denotes a cycloaliphatic group having 3, 4 or 5 ring atoms, which is optionally substituted with alkyl or alkenyl each having up to 3 C atoms, or with halogen or CN, and preferably denotes cyclopropyl, cyclobutyl or cyclopentyl.

[0238] The compounds of formulae B1-1A and/or B1-2A are contained in the medium either alternatively or in addition to the compounds of formulae B1-1 and B1-2, preferably additionally.

[0239] Very preferred compounds of the formulae B1-1A and/or B1-2A are the following:

##STR00119##

in which alkoxy denotes a straight-chain alkoxy radical having 1 to 6 C atoms or alternatively (CH.sub.2).sub.nF in which n is 2,3,4, or 5, preferably C.sub.2H.sub.4F.

[0240] The proportion of the compounds of Formula B1 or its subformulae in the medium is preferably from 1 to 20%, very preferably from 1 to 15% by weight.

[0241] Preferably, the medium contains 1, 2 or 3 compounds of Formula B1 or its subformulae.

[0242] In a preferred embodiment of the present invention, the medium may comprise one or more compounds of Formula B2-2

##STR00120##

in which [0243] R.sup.1, R.sup.3 identically or differently, denote H, an alkyl or alkoxy radical having 1 to 6 C atoms, in which one or more CH.sub.2 groups in these radicals are optionally replaced, independently of one another, by CC, CF.sub.2O, OCF.sub.2, CHCH,

##STR00121## [0244] O, COO or OCO in such a way that 0 atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen.

[0245] The compounds of Formula B2-2 are preferably selected from the group of compounds of the formulae B2-2-1 to B2-2-10:

##STR00122## ##STR00123## [0246] in which R.sup.3 denotes alkyl having 1 to 6 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively (CH.sub.2).sub.nF in which n is 2,3,4, or 5, preferably C.sub.2H.sub.4F.

[0247] Particularly preferred compounds of Formula B2 are selected from the following subformulae:

##STR00124##

[0248] The proportion of the compounds of Formula B2 or its subformulae in the medium is preferably from 1 to 20%, very preferably from 1 to 15% by weight.

[0249] Preferably, the LC medium contains 1, 2 or 3 compounds of Formula B2 or its subformulae.

[0250] Preferred compounds of Formula B3 are selected from the following subformulae:

##STR00125## [0251] wherein R.sup.1 has one of the meanings given in Formula B3 and preferably denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl, and X.sup.1 has one of the meanings given in Formula B3 and preferably denotes CF.sub.3 or OCF.sub.3.

[0252] Preferred compounds of Formula B3 are selected from the following subformulae:

##STR00126## [0253] wherein R.sup.1 has one of the meanings given in Formula B3 and preferably denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl.

[0254] Most preferred are compounds of formulae B3-1-1 and B3-2-2.

[0255] In another preferred embodiment, the medium contains one or more compounds of Formula B or its subformulae B1, B2, B3, B1-1, B1-2, B2-1, B2-2, B2-3, B3-1, B3-2, B3-1-1, B3-1-2, B3-2-1 and B3-2-2 wherein the dibenzofuran or dibenzothiophene group is substituted by a methyl or methoxy group, preferably by a methyl group, preferably in p-position to the substituent F, very preferably in p-position to the substituent F (i.e. in m-position to the terminal group R.sup.2 or X.sup.1).

[0256] The proportion of the compounds of Formula B3 or its subformulae in the LC medium is preferably from 1 to 20%, very preferably from 1 to 10% by weight.

[0257] Preferably, the LC medium contains 1, 2 or 3 compounds of Formula B3 or its subformulae.

[0258] Preferably, the total proportion of compounds of Formula Y and B or their subformulae in the medium is from 2 to 25%, very preferably from 3 to 20% by weight.

[0259] Further preferred embodiments are indicated below: [0260] The medium comprises one or more compounds of Formula Y selected from the following subformula

##STR00127## [0261] wherein R.sup.1, R.sup.2, L.sup.1, L.sup.2, X, x and Z.sup.x have the meanings given in Formula Y, and wherein at least one of the rings X is cyclohexenylene.

[0262] Preferably, both radicals L.sup.1 and L.sup.2 denote F. Further preferably one of the radicals L.sup.1 and L.sup.2 denotes F and the other denotes Cl.

[0263] The compounds of the Formula LY are preferably selected from the group consisting of the following subformulae:

##STR00128## [0264] in which R.sup.1 has the meaning indicated in Formula Y above, (O) denotes an oxygen atom or a single bond, and v denotes an integer from 1 to 6. R.sup.1 preferably denotes straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms, in particular CH.sub.3, C.sub.2H.sub.5, n-C.sub.3H.sub.7, n-C.sub.4Hg, n-C.sub.5H.sub.11, CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.

[0265] Very preferred are compounds of Formula LY4.

[0266] Preferably, the medium contains 1, 2 or 3 compounds of Formula LY, very preferably of Formula LY4.

[0267] The proportion of the compounds of Formula LY or its subformulae in the medium is preferably from 1 to 10% by weight.

[0268] The medium comprises one or more compounds of Formula Y selected from the following subformula

##STR00129## [0269] wherein R.sup.1, R.sup.2, L.sup.1, L.sup.2, Y, y and Z.sup.y have the meanings given in Formula Y, and wherein at least one of the rings Y is tetrahydropyrane.

[0270] The compounds of the Formula AY are preferably selected from the group consisting of the following subformulae:

##STR00130## ##STR00131## [0271] in which R.sup.1 has the meaning indicated above, alkyl denotes a straight-chain alkyl radical having 1 to 6 C atoms, (O) denotes an oxygen atom or a single bond, and v denotes an integer from 1 to 6. R.sup.1 preferably denotes straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms, in particular CH.sub.3, C.sub.2H.sub.5, n-C.sub.3H.sub.7, n-C.sub.4Hg, n-C.sub.5H.sub.11, CH.sub.2=CH, CH.sub.2=CHCH.sub.2CH.sub.2, CH.sub.3CHCH, CH.sub.3CH.sub.2CHCH, CH.sub.3(CH.sub.2).sub.2-CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2. [0272] The medium does not contain a compound of Formula Y, B, LY or AY. [0273] The medium does not contain a compound having a 1,4-phenylene group that is substituted in 2- and 3-position with F or Cl. [0274] The medium additionally comprises one or more compounds selected from the following formulae:

##STR00132## [0275] wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings

##STR00133## [0276] R.sup.0 one of the meanings given for R.sup.1 in Formula I, [0277] X.sup.0 F, Cl, CN, SF.sub.5, SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms, and [0278] Y.sup.1-6 H or F, [0279] Y.sup.0 H or CH.sub.3.

[0280] Preferred compounds of Formula II and III are those wherein Y.sup.0 is H.

[0281] Further preferred compounds of Formula II and III are those wherein R.sup.0 denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, and X.sup.0 denotes F or OCF.sub.3, very preferably F.

[0282] The medium comprises one or more compounds of Formula II selected from the following subformulae:

##STR00134## [0283] in which R.sup.0 and X.sup.0 have the meanings given in Formula II.

[0284] Preferred compounds are those of Formula II1, II2 and II3, very preferred those of Formula II1 and II2.

[0285] In the compounds of formulae II1 to II7 R.sup.0 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, and X.sup.0 preferably denotes F or OCF.sub.3, very preferably F.

[0286] The medium contains one or more compounds of Formula II or their subformulae as described above and below wherein Y.sup.0 is CH.sub.3, very preferably the medium according to this preferred embodiment comprises one or more compounds of Formula II selected from the following subformulae:

##STR00135## [0287] in which R.sup.0 and X.sup.0 have the meanings given in Formula II.

[0288] Preferred compounds are those of Formula IIA1, IIA2 and IIA3, very preferred those of Formula IIA1 and IIA2.

[0289] In the compounds of formulae IIA1 to IIA7 R.sup.0 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, and X.sup.0 preferably denotes F or OCF.sub.3, very preferably F. [0290] The medium comprises one or more compounds of Formula III selected from the following subformulae:

##STR00136## ##STR00137## ##STR00138## [0291] in which R.sup.0 and X.sup.0 have the meanings given in Formula II.

[0292] Preferred compounds are those of Formula III, III4, III6, III16, III19 and III20.

[0293] In the compounds of formulae III1 to III21 R.sup.0 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, X.sup.0 preferably denotes F or OCF.sub.3, very preferably F, and Y.sup.2 preferably denotes F.

[0294] The medium contains one or more compounds of Formula III or their subformulae as described above and below wherein Y.sup.0 is CH.sub.3, very preferably, the medium according to this preferred embodiment comprises one or more compounds of Formula III selected from the following subformulae:

##STR00139## ##STR00140## ##STR00141## [0295] in which R.sup.0 and X.sup.0 have the meanings given in Formula III.

[0296] Preferred compounds are those of Formula IIIA1, IIIA4, IIIA6, IIIA16, IIIA19 and IIIA20.

[0297] In the compounds of formulae IIIA1 to IIIA21 R.sup.0 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, X.sup.0 preferably denotes F or OCF.sub.3, very preferably F, and Y.sup.2 preferably denotes F.

[0298] The medium additionally comprises one or more compounds selected from the following formulae:

##STR00142## [0299] in which [0300] R.sup.0, X.sup.0 and Y.sup.1-5 have the meanings indicated in Formulae II and III, [0301] Z.sup.0 denotes C.sub.2H.sub.4, (CH.sub.2).sub.4, CHCH, CFCF, C.sub.2F.sub.4, CH.sub.2CF.sub.2, CF.sub.2CH.sub.2, CH.sub.2O, OCH.sub.2, COO or OCF.sub.2, in formulae V and VI also a single bond, in formulae V and VIII also CF.sub.2O, [0302] r denotes 0 or 1, and [0303] s denotes 0 or 1.

[0304] The compounds of the Formula IV are preferably selected from the following formulae:

##STR00143## [0305] in which R.sup.0 and X.sup.0 have the meanings indicated in Formulae II and III. [0306] R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F or OCF.sub.3, furthermore OCFCF.sub.2 or Cl.

[0307] The compounds of the Formula IVa are preferably selected from the following subformula:

##STR00144##

[0308] The compounds of the Formula IVb are preferably represented by the following formula:

##STR00145##

[0309] The compounds of the Formula IVc are preferably selected from the following subformula:

##STR00146##

in which R.sup.0 has the meanings indicated in Formula II and is preferably propyl or pentyl.

[0310] The compound(s) of the Formula IVc, in particular of the Formula IVc1, is (are) preferably employed in the mixtures according to the invention in amounts of 1-20% by weight, particularly preferably 2-15% by weight.

[0311] The compounds of the Formula V are preferably selected from the following subformulae:

##STR00147## [0312] in which R.sup.0 and X.sup.0 have the meanings indicated in Formula II. [0313] R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F and OCF.sub.3, furthermore OCHF.sub.2, CF.sub.3, OCFCF.sub.2 and OCHCF.sub.2; [0314] The compounds of the Formula VI are preferably selected from the following subformulae:

##STR00148## [0315] in which R.sup.0 and X.sup.0 have the meanings indicated in Formula II. [0316] R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F, furthermore OCF.sub.3, CF.sub.3, CFCF.sub.2, OCHF.sub.2 and OCHCF.sub.2;

[0317] The compounds of the Formula VII are preferably selected from the following subformulae:

##STR00149## [0318] in which R.sup.0 and X.sup.0 have the meanings indicated in Formula II. [0319] R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F, furthermore OCF.sub.3, OCHF.sub.2 and OCHCF.sub.2.

[0320] In some embodiments, the medium additionally comprises one or more compounds selected from the following formulae:

##STR00150## [0321] in which [0322] R.sup.0 and X.sup.0 each, independently of one another, have one of the meanings indicated in Formula II, [0323] Y.sup.1-4 each, independently of one another, denote H or F, [0324] Y.sup.5 denotes H or CH.sub.3, preferably H, [0325] X.sup.0 is preferably F, Cl, CF.sub.3, OCF.sub.3 or OCHF.sub.2, [0326] R.sup.0 preferably denotes alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0327] Very preferably, the medium according to the invention comprises one or more compounds of the Formula XXa,

##STR00151## [0328] in which R.sup.0 has the meanings of R.sup.1 in Formula I. R.sup.0 preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0329] The compound(s) of the Formula XX, in particular of the Formula XXa, is (are) preferably employed in the mixtures according to the invention in amounts of 0-15% by weight, particularly preferably 1-10% by weight.

[0330] Very preferably, the medium according to the invention comprises one or more compounds of the Formula XXIa,

##STR00152## [0331] in which R.sup.0 has the meaning of R.sup.1 in Formula I. R.sup.0 preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0332] The compound(s) of the Formula XXI, in particular of the Formula XXIa, is (are) preferably employed in the mixtures according to the invention in amounts of 1-15% by weight, particularly preferably 2-10% by weight.

[0333] Further preferably the medium according to the invention comprises one or more compounds of the Formula XXIIIa,

##STR00153## [0334] in which R.sup.0 has the meaning of R.sup.1 in Formula I. R.sup.0 preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0335] The compound(s) of the Formula XXIII, in particular of the Formula XXIIIa, is (are) preferably employed in the mixtures according to the invention in amounts of 0.5-5% by weight, particularly preferably 0.5-2% by weight.

[0336] The medium additionally comprises one or more compounds of the Formula XXIV,

##STR00154##

in which R.sup.0, X.sup.0 and Y.sup.1-6 have the meanings indicated in Formula III, s denotes 0 or 1, and

##STR00155##

denotes

##STR00156##

[0337] In the Formula XXIV, X.sup.0 may also denote an alkyl radical having 1 to 6 C atoms or an alkoxy radical having 1 to 6 C atoms. The alkyl or alkoxy radical is preferably straight-chain.

[0338] R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F;

[0339] The compounds of the Formula XXIV are preferably selected from the following subformulae:

##STR00157## [0340] in which R.sup.0, X.sup.0 and Y.sup.1 have the meanings indicated in Formula III. R.sup.0 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F, and Y.sup.1 is preferably F;

##STR00158##

is preferably

##STR00159## [0341] R.sup.0 is straight-chain alkyl or alkenyl having 2 to 6 C atoms;

[0342] The medium may further comprise one or more compounds of the following formulae:

##STR00160## [0343] in which R.sup.1 and X.sup.0 have the meanings of R.sup.0 and X.sup.0 indicated in Formula II, respectively. R.sup.1 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F or Cl. In the Formula XXIV, X.sup.0 very particularly preferably denotes Cl.

[0344] The medium comprises one or more compounds of the following formulae:

##STR00161##

in which

##STR00162##

and [0345] R.sup.1 and X.sup.0 have the meanings of R.sup.0 and X.sup.0 indicated in Formula II, respectively. R.sup.1 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F. The medium according to the invention particularly preferably comprises one or more compounds of the Formula XXIX in which X.sup.0 preferably denotes F.

[0346] The compound of general formula XXX may be advantageously selected from one of the following formulae XXX1 to XXX3, wherein use of the compound of formula XXX1 is particularly preferred:

##STR00163##

[0347] The compound(s) of the formulae XXVI-XXIX is (are) preferably employed in the mixtures according to the invention in amounts of 1-20% by weight, particularly preferably 1-15% by weight. Particularly preferred mixtures comprise at least one compound of the Formula XXIX.

[0348] In some further embodiments, the medium comprises one or more compounds of the following formulae:

##STR00164## [0349] in which R.sup.1 and R.sup.2 have the meanings indicated in Formula I, and preferably each, independently of one another, denote alkyl having 1 to 6 C atoms.

[0350] Very preferably, the medium according to the invention comprises one or more compounds of the Formula XXIXa:

##STR00165## [0351] in which R.sup.1 has the meanings indicated in Formula I, and preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0352] The compound(s) of the Formula XXIXa is (are) preferably employed in the mixtures according to the invention in amounts of 1-15% by weight, particularly preferably 2-10% by weight.

[0353] The medium may further comprise one or more compounds of the following pyrimidine or pyridine compounds of the formulae

##STR00166## [0354] in which R.sup.1 and X.sup.0 have the meanings indicated in Formula II for R.sup.0 and X.sup.0, respectively. R.sup.1 preferably denotes alkyl having 1 to 6 C atoms. X.sup.0 preferably denotes F. The medium according to the invention particularly preferably comprises one or more compounds of the Formula XXXI1, in which X.sup.0 preferably denotes F. The compound(s) of the formulae XXXI1 to XXXI3 is (are) preferably employed in the mixtures according to the invention in amounts of 1-20% by weight, particularly preferably 1-15% by weight.

[0355] The medium may additionally comprise one or more compounds of the following formulae:

##STR00167## [0356] in which L, R.sup.1 and R.sup.2 have the meanings indicated in Formula Y for Y.sup.1, R.sup.1 and R.sup.2, respectively. R.sup.1 and R.sup.2 preferably denote alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0357] Very preferably, the medium according to the invention comprises one or more compounds of the formula XXXVa,

##STR00168## [0358] in which alkyl denotes a straight-chain alkyl radical having 1 to 6 C atoms, in particular ethyl, propyl or pentyl.

[0359] The compound(s) of the formula XXXV, in particular of the formula XXXVa, is (are) preferably employed in the mixtures according to the invention in amounts of 0.5-10% by weight, particularly preferably 1-5% by weight.

[0360] Further preferred LC media are selected from the following preferred embodiments, including any combination thereof:

[0361] The total content of compounds of the formula I in the LC medium is preferably 2 to 80% by weight, preferably 5 to 70% by weight, and particularly preferably 10 to 60% by weight, based on the weight of the LC medium.

[0362] It has proved surprisingly advantageous to select the compounds of formula I in such a way that they can be described in the LC medium of the invention by a single formula selected from I-1-1 to I-1-17 and I-2-1 to I-2-53. It is particularly preferred that all compounds of formula I can be described in the LC medium of the invention by a single structure selected from the following list: [0363] I-3-1, I-3-2, I-3-3, I-3-4, I-3-5, I-3-6, I-3-7, I-3-8, I-3-9, I-3-10, I-3-11, I-3-12, I-3-15, I-3-16, I-3-17, I-3-18, I-3-19, I-3-20, I-3-21, I-3-22.

[0364] Thus, the LC medium according to the invention may in particular comprise a combination of at least two different compounds of the general formula selected from the following compounds: [0365] I-3-9-2-2, I-3-9-3-2, I-3-9-4-5, I-3-9-5-5, I-3-9-6-5, I-3-22-4, I-3-6-3.

[0366] It has been shown that a combination of at least two different compounds of formula I in the LC medium of the present invention not only has much better solubility than a single compound of formula I but also exhibits significantly improved stability to UV radiation and elevated temperatures. The stabilizing effect of the compounds of the general formula H is thereby synergistically enhanced.

[0367] If two compounds of formula I are present in the LC medium of the invention, their weight ratio is preferably between 10:90 and 90:10, particularly preferably between 20:80 and 80:20, even more preferably between 30:70 and 70:30, based on the total weight of the two compounds of formula I.

[0368] Preferably, the proportion of compounds of Formula ST, as described above or listed in Table G, in the LC medium is from 10 to 2000 ppm, very preferably from 30 to 1000 ppm by weight.

[0369] Preferred content of the one or more compounds of Formula H in the LC medium depends inter alia on the inherent chemical stability of the LC medium as well as on the nature of the compound of Formula H. Compounds of Formula H in which R.sup.16 denotes O.Math., which are known as NO radical type HALS are preferably used in proportion ranging from 50 ppm to 1000 ppm by weight, based on the weight of the LC medium. Compounds of Formula H in which R.sup.16 denotes a H atom, which are known as NH radical type HALS are advantageously used in proportion ranging from 50 ppm to 2000 ppm by weight, based on the weight of the LC medium. [0370] The medium comprises two or more, preferably three or more, compounds of formula I or its sub-formulae, a compound of formula H and one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4, Z5, Y, B, LY, AY, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVIIa, XVIIb, XVIIc, XVIII, XIX, XX, XXI, XII, XXIII, XXIV, XXV, XXVI, XXVII, XXVIII, XXIX, XXXI, XXXI1, XXXI2, XXXI3, XXXII, XXXIII, XXXIV and XXXV and their sub-formulae. [0371] The medium comprises two or more, preferably three or more, compounds of formula I or its sub-formulae, a compound of formula H and one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4, Z5, Y, B, II, III, IV, VI, IX, X, XIV, XVI, XVIIa, XVIIb, XVIIc, XX, XII, XXIII, XXIX, XXXII and XXXV and their sub-formulae. [0372] The medium does not contain a compound of formula Y, B, AY or LY. [0373] The medium comprises one or more compounds of the formula II, preferably selected from the group consisting of formula II1, II2 and II3, very preferably from formula II1 and II2. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 25% by weight. [0374] The medium comprises one or more compounds of the formula III, preferably selected from the group consisting of formula III1, III4, III6, III16, III19 and III20, very preferably from the group consisting of formula III1, III6, III16 and III20. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 30% by weight. [0375] The medium comprises one or more compounds of the formula IV, preferably selected from formula IVa or IVc, very preferably from formula IVa1 or IVc1, most preferably of formula IVc1. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight. [0376] The medium comprises one or more compounds of the formula VI, preferably selected from formula VIb. The individual concentration of each of these compounds is preferably from 1 to 20% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight. [0377] The medium comprises one or more compounds of the formula Z1, preferably selected from formula Z1-1. The total concentration of these compounds is preferably from 1 to 25% by weight. [0378] The medium comprises one or more compounds of the formula Z2, preferably selected from formulae Z2-1 and Z2-2. The total concentration of these compounds is preferably from 2 to 35%, very preferably from 3 to 25% by weight. [0379] The medium comprises from 5 to 20% by weight of compounds of formula Z3, preferably of formula Z3-1. [0380] The medium comprises from 5 to 20% by weight of compounds of formula Z4, preferably of formula Z4-1. [0381] The medium comprises from 10 to 65%, very preferably from 20 to 60% by weight of compounds of formula Z5. [0382] The medium comprises one or more compounds of the formula XII, preferably of the formula XIIa or XIIb, very preferably of formula XIIa, most preferably of formula XIIa1. The concentration of these compounds is preferably from 2 to 15% by weight. [0383] The medium comprises from 1 to 15% by weight of compounds of formula XIIb. [0384] The medium comprises one or more compounds of the formula XIV, preferably of the formula XIVd, very preferably of formula XIVd1. The concentration of these compounds is preferably from 2 to 10% by weight. [0385] The medium comprises one or more compounds of the formula XVIb, preferably of formula XVIb1, XVIb2 and/or XVI3. The concentration of these compounds is preferably from 2 to 15% by weight. [0386] The medium comprises one or more compounds of the formula XVIc, preferably of formula XVIc1, XVIc2 and/or XVIc3. The concentration of these compounds is preferably from 2 to 20% by weight. [0387] The medium comprises one or more compounds of the formula XVIg, preferably of the formula XVIg1 and/or XVIg2. The total concentration of these compounds is preferably from 5 to 25% by weight. [0388] The medium comprises one or more compounds selected from the group consisting of the formulae XVIIa, XVIIb and XVIIc, very preferably of formula XVIIa wherein L is H and of formula XVIIb wherein L is F. The total concentration of these compounds is preferably from 0.5 to 5% by weight. [0389] The medium comprises one or more compounds of the formula XX, preferably of the formula XXa. The concentration of these compounds is preferably from 2 to 10% by weight. [0390] The medium comprises one or more compounds of the formula XXI, preferably of the formula XXIa. The concentration of these compounds is preferably from 2 to 10% by weight. [0391] The medium comprises one or more compounds of the formula XXIII, preferably of the formula XXIIIa. The concentration of these compounds is preferably from 0.5 to 5% by weight. [0392] The medium comprises one or more compounds of the formula XXIX, preferably of the formula XXIXa. The concentration of these compounds is preferably from 2 to 10% by weight. [0393] The medium comprises one or more compounds of the formula XXXI, preferably of the formula XXXIa. The concentration of these compounds is preferably from 2 to 10% by weight. [0394] The medium comprises one or more compounds of the formula XXXII. The concentration of these compounds is preferably from 2 to 10% by weight. [0395] The medium comprises one or more compounds of the formula XXXII. The concentration of these compounds is preferably from 2 to 10% by weight. [0396] The medium comprises one or more compounds of the formula XXXV, preferably of the formula XXXVa. The concentration of these compounds is preferably from 1 to 5% by weight. [0397] The medium comprises two or more, preferably three or more, compounds of formula I, preferably of formula I-2-6, a compound of formula H, one or more compounds selected from the group consisting of the formulae Z1, Z2 and Z3, Z4, Z5 or their sub-formulae, one or more compounds selected from the group consisting of formula XIV or their sub-formulae, one or more compounds selected from the group consisting of formulae II, III, IV, VI, XX, XXIII and XXIX or their sub-formulae, and one or more compounds selected from the group consisting of the formulae XII, XVI, XVIIa, XVIIb, XVIIc, XXXII and XXXV or their sub-formulae.

[0398] The medium comprises two or more, preferably three or more, compounds of formula I, preferably of formula I-2-6, a compound of formula H, one or more compounds selected from the group consisting of the formulae Z1, Z2 and Z3, Z4, Z5 or their sub-formulae, one or more compounds selected from the group consisting of formulae Z1-1, Z2-2, Z5 and XIVd or their sub-formulae, one or more compounds selected from the group consisting of formulae II, III, IVc, VIb, XXa, XXIIIa and XXIXa or their sub-formulae, and one or more compounds selected from the group consisting of the formulae XIIb, XVIb, XVIc, XVIIa, XVIIb, XVIIc, XXXII and XXXVa or their sub-formulae. [0399] The medium comprises two or more, preferably three or more, compounds of formula I, preferably of formula I-2-6, a compound of formula H, one or more compounds selected from the group consisting of the formulae Z1, Z2, Z3, Z4 and Z4 or their sub-formulae, one or more compounds of formula Y, preferably selected from the group consisting of the formulae Y1 and Y2, one or more compounds selected from the group consisting of formula XIV or their sub-formulae, one or more compounds selected from the group consisting of formulae II, III, IV, VI, XX, XXIII and XXIX or their sub-formulae, and one or more compounds selected from the group consisting of the formulae XII, XVI, XVIIa, XVIIb, XVIIc, XXXII and XXXV or their sub-formulae. [0400] The medium comprises two or more, preferably three or more, compounds of formula I, preferably of formula I-2-6, a compound of formula H, one or more compounds selected from the group consisting of the formulae Z1, Z2, Z3, Z4 and Z5 or their sub-formulae, one or more compounds of formula B, preferably selected from the group consisting of the formulae B1, B2 and B3, one or more compounds selected from the group consisting of formulae Z1-1, Z2-2, Z5 and XIVd or their sub-formulae, one or more compounds selected from the group consisting of formulae II, III, IVc, VIb, XXa, XXIIIa and XXIXa or their sub-formulae, and one or more compounds selected from the group consisting of the formulae XIIb, XVIb, XVIc, XVIIa, XVIIb, XVIIc, XXXII and XXXVa or their sub-formulae. [0401] Besides the compounds of the formulae I and H, the medium comprises further compounds selected from the group of the compounds of the formula Z1, Z2, Z3, Z4, Z5, Y, B, IV, XII, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXXI, XXXII and XXIV or their sub-formulae. [0402] Besides the compounds of the formulae I and H, the medium comprises further compounds selected from the group of the compounds of the formula Z1, Z2, Z3, IV, XII, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXXI, XXXII and XXXIV or their sub-formulae. [0403] The proportion of compounds of formula I or its sub-formulae in the medium is from 1 to 30%, very preferably from 2 to 25%, most preferably from 2 to 20% by weight. [0404] The proportion of compounds of the formula Z1, Z2 and Z3 or their sub-formulae in the mixture as a whole is from 10 to 65%, very preferably from 20 to 60%. [0405] The proportion of compounds of the formula Y or its sub-formulae in the mixture as a whole is from 1 to 20%, very preferably from 2 to 15%. [0406] The proportion of compounds of the formula B or its sub-formulae in the mixture as a whole is from 1 to 20%, very preferably from 2 to 18%. [0407] The proportion of compounds of the formulae II, III, IV-VIII, XVIII-XXIII and XXVII-XXX in the mixture as a whole is 30 to 60% by weight. [0408] The proportion of compounds of the formulae IX-XV in the mixture as a whole is 40 to 70% by weight. [0409] The proportion of compounds of the formulae XIV, XVIIa-c and XXXII-XXXV in the mixture as a whole is 0.5 to 15% by weight.

[0410] The term alkyl or alkyl* in this application encompasses straight-chain and branched alkyl groups having 1 to 6 carbon atoms, in particular the straight-chain groups methyl, ethyl, propyl, butyl, pentyl and hexyl. Groups having 2 to 5 carbon atoms are generally preferred.

[0411] The term alkenyl or alkenyl* encompasses straight-chain and branched alkenyl groups having 2 to 6 carbon atoms, in particular the straight-chain groups.

[0412] Preferred alkenyl groups are C.sub.2-C.sub.7-1E-alkenyl, C.sub.4-C.sub.6-3E-alkenyl, in particular C.sub.2-C.sub.6-1E-alkenyl. Examples of particularly preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl and 5-hexenyl. Groups having up to 5 carbon atoms are generally preferred, in particular CH.sub.2=CH, CH.sub.3CHCH.

[0413] The term fluoroalkyl preferably encompasses straight-chain groups having a terminal fluorine, i.e. fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. However, other positions of the fluorine are not excluded.

[0414] The term oxaalkyl or alkoxy preferably encompasses straight-chain radicals of the formula C.sub.nH.sub.2n+1O(CH.sub.2).sub.m, in which n and m each, independently of one another, denote 1 to 6. m may also denote 0. Preferably, n=1 and m=1-6 or m=0 and n=1-3. Further preferably the alkoxy or oxaalkyl group can also contain one or more further O atoms such that oxygen atoms are not directly linked to one another.

[0415] Through a suitable choice of the meanings of R.sup.0 and X.sup.0, the addressing times, the threshold voltage, the steepness of the transmission characteristic lines, etc., can be modified in the desired manner. For example, 1E-alkenyl radicals, 3E-alkenyl radicals, 2E-alkenyloxy radicals and the like generally result in shorter addressing times, improved nematic tendencies and a higher ratio between the elastic constants k.sub.33 (bend) and k.sub.11 (splay) compared with alkyl and alkoxy radicals. 4-Alkenyl radicals, 3-alkenyl radicals and the like generally give lower threshold voltages and lower values of k.sub.33/k.sub.11 compared with alkyl and alkoxy radicals.

[0416] The mixtures according to the invention are distinguished, in particular, by high values and thus have significantly faster response times than the mixtures from the prior art.

[0417] The optimum mixing ratio of the compounds of the above-mentioned formulae depends substantially on the desired properties, on the choice of the components of the above-mentioned formulae and on the choice of any further components that may be present.

[0418] Suitable mixing ratios within the range indicated above can easily be determined from case to case.

[0419] The total amount of compounds of the above-mentioned formulae in the liquid-crystalline media according to the invention is not crucial. The mixtures can therefore comprise one or more further components for the purposes of optimisation of various properties. However, the observed effect on the desired improvement in the properties of the medium is generally greater, the higher the total concentration of compounds of the above-mentioned formulae.

[0420] In a particularly preferred embodiment, the liquid-crystalline media according to the invention comprise compounds of the formulae IV to VIII (preferably IV and V) in which X.sup.0 denotes F, OCF.sub.3, OCHF.sub.2, OCHCF.sub.2, OCFCF.sub.2 or OCF.sub.2CF.sub.2H. A favourable synergistic action with the compounds of the formulae I, II and III results in particularly advantageous properties. In particular, mixtures comprising compounds of the formulae I, H, II and III are distinguished by their low threshold voltage.

[0421] The individual compounds of the above-mentioned formulae and the sub-formulae thereof which can be used in the liquid-crystalline media according to the invention are either known or can be prepared analogously to the known compounds.

[0422] The invention also relates to a process for the preparation of a liquid-crystalline medium as described above and below, by mixing one or more compounds of the formula I with one or more compounds of the formulae Y1, Y2 or Y3, one or more compounds of formula B, and one or more compounds selected from the group consisting of formulae II, III, IV, VI, XIV, XII, XVI, XVIIa, XVIIb, XVIIc, XX, XXIII, XXIX, XXXII and XXXV.

[0423] In another preferred embodiment of the present invention, the liquid-crystalline medium additionally comprises one or more polymerizable compounds. The polymerizable compounds are preferably selected from formula M

R.sup.aB.sup.1(Z.sup.bB.sup.2).sub.mR.sup.bM [0424] in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning: [0425] R.sup.a and R.sup.b P, P-Sp-, H, F, Cl, Br, I, CN, NO.sub.2, NCO, NCS, OCN, SCN, SF.sub.5 or straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH.sub.2 groups may each be replaced, independently of one another, by C(R.sup.0)C(R.sup.00), CC, N(R.sup.00), O, S, CO, COO, OCO, OCOO in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, C, Br, I, CN, P or P-Sp-, where, if B.sup.1 and/or B.sup.2 contain a saturated C atom, R.sup.a and/or R.sup.b may also denote a radical which is spiro-linked to this saturated C atom, [0426] wherein at least one of the radicals R.sup.a and R.sup.b denotes or contains a group P or P-Sp-, [0427] P a polymerizable group, [0428] Sp a spacer group or a single bond, [0429] B.sup.1 and B.sup.2 an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, and which is unsubstituted, or mono- or polysubstituted by L, [0430] Z.sup.b O, S, CO, COO, OCO, OCOO, OCH.sub.2, CH.sub.2O, SCH.sub.2, CH.sub.2S, CF.sub.2O, OCF.sub.2, CF.sub.2S, SCF.sub.2, (CH.sub.2).sub.n1, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, (CF.sub.2).sub.n1, CHCH, CFCF, CC, CHCHCOO, OCOCHCH, CR.sup.0R.sup.00 or a single bond, [0431] R.sup.0 and R.sup.00 each, independently of one another, denote H or alkyl having 1 to 12 C atoms, [0432] m denotes 0, 1, 2, 3 or 4, [0433] n1 denotes 1, 2, 3 or 4, [0434] L P, P-Sp-, OH, CH.sub.2OH, F, Cl, Br, I, CN, NO.sub.2, NCO, NCS, OCN, SCN, C(O)N(R.sup.x).sub.2, C(O)Y.sup.1, C(O)R.sup.x, N(R.sup.x).sub.2, optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms, or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, in which, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-, [0435] P and Sp have the meanings indicated above, [0436] Y.sup.1 denotes halogen, [0437] R.sup.x denotes P, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH.sub.2 groups may be replaced by O, S, CO, COO, OCO, OCOO in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-, an optionally substituted aryl or aryloxy group having 6 to 40 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 C atoms.

[0438] Particularly preferred compounds of the formula M are those in which B.sup.1 and B.sup.2 each, independently of one another, denote 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydro-phenanthrene-2,7-diyl, anthracene-2,7-diyl, fluorene-2,7-diyl, coumarine, flavone, where, in addition, one or more CH groups in these groups may be replaced by N, cyclohexane-1,4-diyl, in which, in addition, one or more non-adjacent CH.sub.2 groups may be replaced by O and/or S, 1,4-cyclohexenylene, bicycle[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl or octahydro-4,7-methanoindane-2,5-diyl, where all these groups may be unsubstituted or mono- or polysubstituted by L as defined above.

[0439] Particularly preferred compounds of the formula M are those in which B.sup.1 and B.sup.2 each, independently of one another, denote 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl.

[0440] Very preferred compounds of formula M are selected from the following formulae:

##STR00169## ##STR00170## ##STR00171## ##STR00172## ##STR00173## [0441] in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning: [0442] P.sup.1, P.sup.2, P.sup.3 a polymerizable group, preferably selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, [0443] Sp.sup.1, Sp.sup.2, Sp.sup.3 a single bond or a spacer group where, in addition, one or more of the radicals P.sup.1-Sp.sup.1-, P.sup.1Sp.sup.2- and P.sup.3Sp.sup.3- may denote R.sup.aa, with the proviso that at least one of the radicals P.sup.1-Sp.sup.1-, P.sup.2Sp.sup.2 and P.sup.3Sp.sup.3- present is different from R.sup.aa, preferably (CH.sub.2).sub.p1, (CH.sub.2).sub.p1O, (CH.sub.2).sub.p1COO or (CH.sub.2).sub.p1OCOO, wherein p1 is an integer from 1 to 12, [0444] R.sup.aa H, F, Cl, CN or straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH.sub.2 groups may each be replaced, independently of one another, by C(R.sup.0)C(R.sup.00), CC, N(R.sup.0), O, S, CO, COO, OCO, OCOO in such a way that O and/or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, CN or P.sup.1Sp.sup.1-, particularly preferably straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms (where the alkenyl and alkynyl radicals have at least two C atoms and the branched radicals have at least three C atoms), [0445] R.sup.0, R.sup.00 H or alkyl having 1 to 12 C atoms, [0446] R.sup.y and R.sup.z H, F, CH.sub.3 or CF.sub.3, [0447] X.sup.1, X.sup.2, X.sup.3 COO, OCO or a single bond, [0448] Z.sup.M1 O, CO, C(R.sup.yR.sup.z) or CF.sub.2CF.sub.2, [0449] Z.sup.M2, Z.sup.M3 COO, OCO, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2 or (CH.sub.2).sub.n, where n is 2, 3 or 4, [0450] L F, Cl, CN or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, [0451] L, L H, F or C, [0452] r 0, 1, 2, 3 or 4, [0453] s 0, 1, 2 or 3, [0454] t 0, 1 or 2, [0455] x 0 or 1.

[0456] Especially preferred are compounds of formulae M2 and M13.

[0457] Further preferred are trireactive compounds M15 to M31, in particular M17, M18, M19, M22, M23, M24, M25, M30 and M31.

[0458] In the compounds of formulae M1 to M31 the group

##STR00174##

is preferably

##STR00175## [0459] wherein L on each occurrence, identically or differently, has one of the meanings given above or below, and is preferably F, Cl, CN, NO.sub.2, CH.sub.3, C.sub.2H.sub.5, C(CH.sub.3).sub.3, CH(CH.sub.3).sub.2, CH.sub.2CH(CH.sub.3)C.sub.2H.sub.5, OCH.sub.3, OC.sub.2H.sub.5, COCH.sub.3, COC.sub.2H.sub.5, COOCH.sub.3, COOC.sub.2H.sub.5, CF.sub.3, OCF.sub.3, OCHF.sub.2, OC.sub.2F.sub.5 or P-Sp-, very preferably F, Cl, CN, CH.sub.3, C.sub.2H.sub.5, OCH.sub.3, COCH.sub.3, OCF.sub.3 or P-Sp-, more preferably F, Cl, CH.sub.3, OCH.sub.3, COCH.sub.3 or OCF.sub.3, especially F or CH.sub.3.

[0460] Preferred compounds of formulae M1 to M31 are those wherein P.sup.1, P.sup.2 and P.sup.3 denote an acrylate, methacrylate, oxetane or epoxy group, very preferably an acrylate or methacrylate group.

[0461] Further preferred compounds of formulae M1 to M31 are those wherein Sp.sup.1, Sp.sup.2 and Sp.sup.3 are a single bond.

[0462] Further preferred compounds of formulae M1 to M31 are those wherein one of Sp.sup.1, Sp.sup.2 and Sp.sup.3 is a single bond and another one of Sp.sup.1, Sp.sup.2 and Sp.sup.3 is different from a single bond.

[0463] Further preferred compounds of formulae M1 to M31 are those wherein those groups Sp.sup.1, Sp.sup.2 and Sp.sup.3 that are different from a single bond denote (CH.sub.2).sub.s1X, wherein s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5, and X is X is the linkage to the benzene ring and is O, OCO, COO, OCOO or a single bond.

[0464] Particular preference is given to liquid-crystalline media comprising one, two or three polymerizable compounds of formula M, preferably selected from formulae M1 to M31.

[0465] Further preferably the liquid-crystalline media according to the present invention comprise one or more polymerizable compounds selected from Table E below.

[0466] Preferably, the proportion of polymerizable compounds in the liquid-crystalline medium, preferably selected from formula M and Table E, is from 0.01 to 5%, very preferably from 0.05 to 1%, most preferably from 0.1 to 0.5%.

[0467] It was observed that the addition of one or more polymerizable compounds to the liquid-crystalline medium, like those selected from formula M and Table E, leads to advantageous properties like fast response times. Such a liquid-crystalline medium is especially suitable for use in PSA displays where it shows low image sticking, a quick and complete polymerisation, the quick generation of a low pretilt angle which is stable after UV exposure, a high reliability, high VHR value after UV exposure, and a high birefringence. By appropriate selection of the polymerizable compounds it is possible to increase the absorption of the liquid-crystalline medium at longer UV wavelengths, so that it is possible to use such longer UV wavelengths for polymerisation, which is advantageous for the display manufacturing process.

[0468] The polymerizable group P is a group which is suitable for a polymerisation reaction, such as, for example, free-radical or ionic chain polymerisation, polyaddition or polycondensation, or for a polymer-analogous reaction, for example addition or condensation onto a main polymer chain. Particular preference is given to groups for chain polymerisation, in particular those containing a CC double bond or CC triple bond, and groups which are suitable for polymerisation with ring opening, such as, for example, oxetane or epoxide groups.

[0469] Preferred groups P are selected from the group consisting of CH.sub.2CW.sup.1COO, CH.sub.2=CW.sup.1CO,

##STR00176##

CH.sub.2=CW.sup.2(O).sub.k3, CW.sup.1=CHCO(O).sub.k3, CW.sup.1=CHCONH, CH.sub.2=CW.sup.1CONH, CH.sub.3CHCHO, (CH.sub.2=CH).sub.2CHOCO, (CH.sub.2=CHCH.sub.2).sub.2CHOCO, (CH.sub.2=CH).sub.2CHO, (CH.sub.2=CHCH.sub.2).sub.2N, (CH.sub.2=CHCH.sub.2).sub.2NCO, HOCW.sup.2W.sup.3, HSCW.sup.2W.sup.3, HW.sup.2N, HOCW.sup.2W.sup.3NH, CH.sub.2=CW.sup.1CONH, CH.sub.2=CH(COO).sub.k1-Phe-(O).sub.k2, CH.sub.2=CH(CO).sub.k1-Phe-(O).sub.k2, Phe-CHCH, HOOC, OCN and W.sup.4W.sup.5W.sup.6Si, in which W.sup.1 denotes H, F, Cl, CN, CF.sub.3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH.sub.3, W.sup.2 and W.sup.3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W.sup.4, W.sup.5 and W.sup.6 each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W.sup.7 and W.sup.8 each, independently of one another, denote H, Cl or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is optionally substituted by one or more radicals L as defined for Formula M above which are other than P-Sp-, k.sub.1, k.sub.2 and k.sub.3 each, independently of one another, denote 0 or 1, k.sub.3 preferably denotes 1, and k.sub.4 denotes an integer from 1 to 10.

[0470] Very preferred groups P are selected from the group consisting of CH.sub.7=CW.sup.1COO, CH.sub.2=CW.sup.1CO,

##STR00177##

CH.sub.2=CW.sup.2O, CH.sub.2=CW.sup.2, CW.sup.1=CHCO(O).sub.k3, CW.sup.1=CHCONH, CH.sub.2=CWCONH, (CH.sub.2=CH).sub.2CHOCO, (CH.sub.2=CHCH.sub.2).sub.2CHOCO, (CH.sub.2=CH).sub.2CHO, (CH.sub.2=CHCH.sub.2).sub.2N, (CH.sub.2=CHCH.sub.2).sub.2NCO, CH.sub.2=CW.sup.1CONH, CH.sub.2=CH(COO).sub.k1-Phe-(O).sub.k2, CH.sub.2=CH(CO).sub.k1-Phe-(O).sub.k2, Phe-CHCH and W.sup.4W.sup.5W.sup.6Si, in which W.sup.1 denotes H, F, C, CN, CF.sub.3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, C or CH.sub.3, W.sup.2 and W.sup.3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W.sup.4, W.sup.5 and W.sup.6 each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W.sup.7 and W.sup.8 each, independently of one another, denote H, Cl or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, k.sub.1, k.sub.2 and k.sub.3 each, independently of one another, denote 0 or 1, k.sub.3 preferably denotes 1, and k.sub.4 denotes an integer from 1 to 10.

[0471] Very particularly preferred groups P are selected from the group consisting of CH.sub.2CW.sup.1COO, in particular CH.sub.2=CHCOO, CH.sub.2=C(CH.sub.3)COO and CH.sub.2=CFCOO, furthermore CH.sub.2=CHO, (CH.sub.2=CH).sub.2CHOCO, (CH.sub.2=CH).sub.2CHO,

##STR00178##

[0472] Further preferred polymerizable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate.

[0473] If Sp is different from a single bond, it is preferably of the formula SpX, so that the respective radical P-Sp- conforms to the formula P-SpX, wherein [0474] Sp denotes alkylene having 1 to 20, preferably 1 to 12, C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN and in which, in addition, one or more non-adjacent CH.sub.2 groups may each be replaced, independently of one another, by O, S, NH, N(R.sup.0), Si(R.sup.0R.sup.00), CO, COO, OCO, OCOO, SCO, COS, N(R.sup.00)COO, OCON(R.sup.0), N(R.sup.0)CON(R.sup.00), CHCH or CC in such a way that O and/or S atoms are not linked directly to one another, [0475] X denotes O, S, CO, COO, OCO, OCOO, CON(R.sup.0), N(R.sup.0)CO, N(R.sup.0)CON(R.sup.00), OCH.sub.2, CH.sub.2O, SCH.sub.2, CH.sub.2S, CF.sub.2O, OCF.sub.2, CF.sub.2S, SCF.sub.2, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, CF.sub.2CF.sub.2, CHN, NCH, NN, CHCR.sup.0, CY.sup.2=CY.sup.3, CC, CHCHCOO, OCOCHCH or a single bond, [0476] R.sup.0 and R.sup.00 each, independently of one another, denote H or alkyl having 1 to 20 C atoms, and [0477] Y.sup.2 and Y.sup.3 each, independently of one another, denote H, F, C or CN. [0478] X is preferably O, S, CO, COO, OCO, OCOO, CONR.sup.0, NR.sup.0CO, NR.sup.0CONR.sup.00 or a single bond.

[0479] Typical spacer groups Sp and -SpX are, for example, (CH.sub.2).sub.p1, (CH.sub.2CH.sub.2O).sub.g1CH.sub.2CH.sub.2, CH.sub.2CH.sub.2SCH.sub.2CH.sub.2, CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2 or (SiR.sup.0R.sup.00O).sub.p1, in which p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R.sup.0 and R.sup.00 have the meanings indicated in Formula M above.

[0480] Particularly preferred groups Sp and -SpX are (CH.sub.2).sub.p1, (CH.sub.2).sub.p1O, (CH.sub.2).sub.p1OCO, (CH.sub.2).sub.p1COO, (CH.sub.2).sub.p1OCOO, in which p1 and q1 have the meanings indicated above.

[0481] Particularly preferred groups Sp are, in each case straight-chain, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutyl-ene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0482] For the production of PSA displays, the polymerizable compounds contained in the liquid-crystalline medium are polymerised or crosslinked (if one compound contains two or more polymerizable groups) by in-situ polymerisation in the liquid-crystalline medium between the substrates of the LC display, optionally while a voltage is applied to the electrodes.

[0483] The structure of the PSA displays according to the invention corresponds to the usual geometry for PSA displays, as described in the prior art cited at the outset. Geometries without protrusions are preferred, in particular those in which, in addition, the electrode on the colour filter side is unstructured and only the electrode on the TFT side has slots. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006/0066793 A1.

[0484] The combination of compounds of the preferred embodiments mentioned above with the polymerised compounds described above causes low threshold voltages, low rotational viscosities and very good low-temperature stabilities in the liquid-crystalline media according to the invention at the same time as constantly high clearing points and high VHR values.

[0485] The use of liquid-crystalline media containing polymerizable compounds allows the rapid establishment of a particularly low pretilt angle in PSA displays. In particular, the liquid-crystalline media exhibit significantly shortened response times, in particular also the grey-shade response times, in PSA displays compared with the media from the prior art.

[0486] Preference is generally given to liquid-crystalline media which have a nematic liquid-crystalline phase, and preferably have no chiral liquid crystal phase.

[0487] The invention also relates to the use of a liquid-crystalline medium according to the present invention as described above and below for electro-optical purposes, in particular for the use is in shutter glasses, for 3D applications, in TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA and positive PS-VA displays, and to electro-optical displays, in particular of the aforementioned types, containing a liquid-crystalline medium according to the present invention as described above and below, in particular a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA (vertically aligned) or positive PS-VA display.

[0488] The invention also relates to electro-optical displays, such as, for example, STN or MLC displays, having two plane-parallel outer plates, which, together with a frame, form a cell, integrated non-linear elements for switching individual pixels on the outer plates, and a nematic liquid-crystal medium having positive dielectric anisotropy and high specific resistance located in the cell, wherein the a nematic liquid-crystal medium is a liquid-crystalline medium according to the present invention as described above and below.

[0489] The liquid-crystalline media according to the invention enable a significant broadening of the available parameter latitude. The achievable combinations of clearing point, viscosity at low temperature, thermal and UV stability and high optical anisotropy are far superior to previous materials from the prior art.

[0490] In particular, the combination of compounds of formula I with compounds of formula Y and/or B, and additionally with compounds selected from formulae II-XXXV or their sub-formulae, leads to liquid-crystalline media which show a moderate positive dielectric anisotropy and at the same time an increased dielectric constant .sub. perpendicular to the longitudinal axes of the liquid-crystalline molecules, while maintaining a low rotational viscosity and a low value of the ratio .sub.1/k.sub.11. This enables liquid-crystalline displays, especially of the FFS, HB-FFS, XB-FFS and IPS mode, with high brightness and transmission and low response times.

[0491] The liquid-crystalline media according to the invention are suitable for mobile applications and TFT applications, such as, for example, mobile telephones and PDAs. Furthermore, the liquid-crystalline media according to the invention are particularly suitably for use in FFS, HB-FFS, XB-FFS and IPS displays based on dielectrically positive liquid crystals.

[0492] The liquid-crystalline media according to the invention, while retaining the nematic phase down to 20 C. and preferably down to 30 C., particularly preferably down to 40 C., and the clearing point 75 C., preferably 80 C., at the same time allow rotational viscosities .sub.1 of 110 mPa.Math.s, particularly preferably 100 mPa.Math.s, to be achieved, enabling excellent MLC displays having fast response times to be achieved. The rotational viscosities are determined at 20 C.

[0493] The dielectric anisotropy of the liquid-crystalline media according to the invention at 20 C. and 1 kHz is preferably +1.5, very preferably from +2 to +6.

[0494] The birefringence n of the liquid-crystalline media according to the invention at 20 C. is preferably from 0.08 to 0.15, very preferably from 0.1 to 0.14.

[0495] The rotational viscosity .sub.1 of the liquid-crystalline media according to the invention is preferably 80 mPa.Math.s, more preferably 70 mPa.Math.s, very preferably 60 mPa s.

[0496] The ratio .sub.1/k.sub.11 (wherein .sub.1 is the rotational viscosity .sub.1 and k.sub.11 is the elastic constant for splay deformation) of the liquid-crystalline media according to the invention is preferably 4.6 mPa.Math.s/pN, very preferably 4.2 mPa.Math.s/pN, most preferably 4.0 mPa.Math.s/pN.

[0497] The nematic phase range of the liquid-crystalline media according to the invention preferably has a width of at least 90 C., more preferably of at least 100 C., in particular at least 110 C. This range preferably extends at least from 25 C. to +80 C.

[0498] It goes without saying that, through a suitable choice of the components of the liquid-crystalline media according to the invention, it is also possible for higher clearing points (for example above 100 C.) to be achieved at higher threshold voltages or lower clearing points to be achieved at lower threshold voltages with retention of the other advantageous properties. At viscosities correspondingly increased only slightly, it is likewise possible to obtain liquid-crystalline media having a higher and thus low thresholds. The MLC displays according to the invention preferably operate at the first Gooch and Tarry transmission minimum [C. H. Gooch and H. A. Tarry, Electron. Lett. 10, 2-4, 1974; C. H. Gooch and H. A. Tarry, Appl. Phys., Vol. 8, 1575-1584, 1975], where, besides particularly favourable electro-optical properties, such as, for example, high steepness of the characteristic line and low angle dependence of the contrast (German patent 30 22 818), lower dielectric anisotropy is sufficient at the same threshold voltage as in an analogous display at the second minimum. This enables significantly higher specific resistance values to be achieved using the mixtures according to the invention at the first minimum than in the case of liquid-crystalline media comprising cyano compounds. Through a suitable choice of the individual components and their proportions by weight, the person skilled in the art is able to set the birefringence necessary for a pre-specified layer thickness of the MLC display using simple routine methods.

[0499] Measurements of the voltage holding ratio (HR) [S. Matsumoto et al., Liquid Crystals 5, 1320 (1989); K. Niwa et al., Proc. SID Conference, San Francisco, June 1984, p. 304 (1984); G. Weber et al., Liquid Crystals 5, 1381 (1989)] have shown that liquid-crystalline media according to the invention comprising compounds of the formulae ST-1, ST-2, RV, IA and IB exhibit a significantly smaller decrease in the HR on UV exposure than analogous mixtures comprising cyanophenylcyclohexanes of the formula

##STR00179##

or esters of the formula

##STR00180##

instead of the compounds of the formulae I ST-1, ST-2, RV, IA and IB.

[0500] The light stability and UV stability of the liquid-crystalline media according to the invention are considerably better, i.e. they exhibit a significantly smaller decrease in the HR on exposure to light, heat or UV.

[0501] The construction of the MLC display according to the invention from polarisers, electrode base plates and surface-treated electrodes corresponds to the usual design for displays of this type. The term usual design is broadly drawn here and also encompasses all derivatives and modifications of the MLC display, in particular including matrix display elements based on poly-Si TFTs or MIM.

[0502] A significant difference between the displays according to the invention and the hitherto conventional displays based on the twisted nematic cell consists, however, in the choice of the liquid-crystal parameters of the liquid-crystal layer.

[0503] The liquid-crystalline media which can be used in accordance with the invention are prepared in a manner conventional per se, for example by mixing one or more compounds of Claim 1 with one or more compounds of the formulae II-XXXV or with further liquid-crystalline compounds and/or additives. In general, the desired amount of the components used in lesser amount is dissolved in the components making up the principal constituent, advantageously at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, for example in acetone, chloroform or methanol, and to remove the solvent again, for example by distillation, after thorough mixing.

[0504] The LC media may also comprise further additives known to the person skilled in the art and described in the literature, such as, for example, polymerisation initiators, inhibitors, surface-active substances, light stabilisers, antioxidants, e.g. BHT, TEMPOL, microparticles, free-radical scavengers, nanoparticles, etc. For example, 0-15% of pleochroic dyes or chiral dopants or initiators like Irgacure651 or Irgacure907 can be added. Suitable stabilisers and dopants are mentioned below in Tables C and D.

[0505] In a preferred embodiment of the present invention, the LC media contain one or more further stabilisers, preferably selected from the group consisting of the following formulae

##STR00181## [0506] wherein [0507] n is an integer from 1 to 6, preferably 3.

[0508] Very preferred stabilisers are selected from the group consisting of the following formulae

##STR00182##

[0509] In a preferred embodiment, the LC medium comprises one or more stabilisers selected from the group consisting of formulae S.sup.1-1, S.sup.2-1.

[0510] In a preferred embodiment, the LC medium comprises one or more stabilisers selected from Table D.

[0511] Preferably, the proportion of stabilisers, like those of formula S1-S3, in the LC medium is from 10 to 2000 ppm, very preferably from 30 to 1000 ppm.

[0512] In another preferred embodiment, the LC medium according to the present invention contains a self-aligning (SA) additive, preferably in a concentration of 0.1 to 2.5%.

[0513] An LC medium according to this preferred embodiment is especially suitable for use in polymer stabilised SA-FFS, SA-HB-FFS or SA-XB-FFS displays.

[0514] In a preferred embodiment, the SA-FFS, SA-HB-FFS or SA-XB-FFS display according to the present invention does not contain a polyimide alignment layer. In another preferred embodiment, the SA-FFS, SA-HB-FFS or SA-XB-FFS display according to that preferred embodiment contains a polyimide alignment layer.

[0515] Preferred SA additives for use in this preferred embodiment are selected from compounds comprising a mesogenic group and a straight-chain or branched alkyl side chain that is terminated with one or more polar anchor groups selected from hydroxy, carboxy, amino or thiol groups.

[0516] Further preferred SA additives contain one or more polymerizable groups which are attached, optionally via spacer groups, to the mesogenic group. These polymerizable SA additives can be polymerised in the LC medium under similar conditions as applied for the RMs in the PSA process.

[0517] Suitable SA additives to induce homeotropic alignment, especially for use in SA-VA mode displays, are disclosed for example in US 2013/0182202 A1, US 2014/0138581 A1, US 2015/0166890 A1 and US 2015/0252265 A1.

[0518] In another preferred embodiment, an LC medium or a polymer stabilised SA-FFS, SA-HB-FFS or SA-XB-FFS display according to the present invention contains one or more self-aligning additives selected from Table F below.

[0519] Furthermore, it is possible to add to the liquid-crystalline media, for example, 0 to 15% by weight of pleochroic dyes, furthermore nanoparticles, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutyl-ammonium tetraphenylborate or complex salts of crown ethers (cf., for example, Haller et al., Mol. Cryst. Liq. Cryst. 24. 249-258 (1973)), for improving the conductivity, or substances for modifying the dielectric anisotropy, the viscosity and/or the alignment of the nematic phases. Substances of this type are described, for example, in DE-A 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

[0520] For the present invention and in the following examples, the structures of the liquid-crystal compounds are indicated by means of acronyms, with the transformation into chemical formulae taking place in accordance with Tables A to C below. All radicals C.sub.mH.sub.2m+1, C.sub.nH.sub.2n+1, and C.sub.lH.sub.2l+1 or C.sub.mH.sup.2m1, C.sub.nH.sub.2n1 and C.sub.lH.sub.2l-1 are straight-chain alkyl radicals or alkylene radicals, in each case having n, m and l C atoms respectively. Preferably, n, m and l are independently of each other 1, 2, 3, 4, 5, 6, or 7. Table A shows the codes for the ring elements of the nuclei of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are composed of the codes for the ring elements with optional linking groups, followed by a first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group. Table D shows illustrative structures of compounds together with their respective abbreviations.

TABLE-US-00001 TABLE A Ring elements C [00183] D [00184] DI [00185] A [00186] AI [00187] P [00188] G [00189] GI [00190] U [00191] UI [00192] Y [00193] P(F, Cl)Y [00194] P(Cl, F)Y [00195] np [00196] n3f [00197] nN3fl [00198] th [00199] thl [00200] tH2f [00201] tH2fl [00202] o2f [00203] o2fl [00204] dh [00205] B [00206] B(S) [00207] O [00208] S [00209] K [00210] KI [00211] L [00212] LI [00213] F [00214] FI [00215] Bh [00216] Bh(S) [00217] Bf [00218] Bf(S) [00219] Bfi [00220] Bfi(S) [00221]

TABLE-US-00002 TABLE B Bridging units E CH.sub.2CH.sub.2 V CHCH T CC W CF.sub.2CF.sub.2 B CFCF Z COO ZI OCO X CFCH XI CHCF O CH.sub.2O OI OCH.sub.2 Q CF.sub.2O QI OCF.sub.2

TABLE-US-00003 TABLE C End groups On the left individually or in On the right individually or in combination combination -n- C.sub.nH.sub.2n+1 -n C.sub.nH.sub.2n+1 -nO C.sub.nH.sub.2n+1O On OC.sub.nH.sub.2n+1 V CH.sub.2CH V CHCH.sub.2 -nV C.sub.nH.sub.2n+1CHCH -nV C.sub.nH.sub.2nCHCH.sub.2 Vn- CH.sub.2CHC.sub.nH.sub.2n Vn CHCHC.sub.nH.sub.2n+1 -nVm- C.sub.nH.sub.2n+1CHCH -nVm C.sub.nH.sub.2nCHCH C.sub.mH.sub.2m C.sub.mH.sub.2m+1 N NC N CN S SCN S NCS F F F F CL Cl CL Cl M CFH.sub.2 M CFH.sub.2 D CF.sub.2H D CF.sub.2H T CF.sub.3 T CF.sub.3 MO CFH.sub.2O OM OCFH.sub.2 DO CF.sub.2HO OD OCF.sub.2H TO CF.sub.3O OT OCF.sub.3 A HCC A CCH -nA C.sub.nH.sub.2n+1CC An CCC.sub.nH.sub.2n+1 NA NCCC AN CCCN -(cn)- [00222] -(cn) [00223] -(cn)m- [00224] -m(cn) [00225] On the left only in combination On the right only in combination - ... n ... - C.sub.nH.sub.2n - ... n ... C.sub.nH.sub.2n - ... M ... - CFH - ... M ... CFH - ... D ... - CF.sub.2 - ... D ... CF.sub.2 - ... V ... - CHCH - ... V ... CHCH - ... Z ... - COO - ... Z ... COO - ... ZI ... - OCO - ... ZI ... OCO - ... K ... - CO - ... K ... CO - ... W ... - CFCF - ... W ... CFCF [0521] in which n and m are each integers, and the three dots . . . are placeholders for other abbreviations from this table.

[0522] The following abbreviations are used: [0523] (n, m, k and l are, independently of one another, each an integer, preferably 1 to 9 preferably 1 to 7, k and l possibly may be also 0 and preferably are 0 to 4, more preferably 0 or 2 and most preferably 2, n preferably is 1, 2, 3, 4 or 5, in the combination -nO- it preferably is 1, 2, 3 or 4, preferably 2 or 4, m preferably is 1, 2, 3, 4 or 5, in the combination -Om it preferably is 1, 2, 3 or 4, more preferably 2 or 4. The combination -IVm preferably is 2V1.)

[0524] Preferred mixture components are shown in Tables D and E.

TABLE-US-00004 TABLE D [00226] PYP [00227] PYRP [00228] BCH [00229] CBC [00230] CCH [00231] CCP [00232] CPTP [00233] CEPTP [00234] ECCP [00235] CECP [00236] EPCH [00237] PCH [00238] CH [00239] PTP [00240] CCPC [00241] CP [00242] BECH [00243] EBCH [00244] CPC [00245] B [00246] FET-nF [00247] CGG [00248] CGU [00249] CFU

Table E

[0525] In the following formulae, n and m each, independently of one another, denote 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, in particular 2, 3, 5, furthermore 0, 4, 6.

TABLE-US-00005 [00250] APU-n-OXF [00251] ACQU-n-F [00252] APUQU-n-F [00253] BCH-nFm [00254] CFU-n-F [00255] CBC-nmF [00256] ECCP-nm [00257] CCZU-n-F [00258] PGP-n-m [00259] CGU-n-F [00260] CDUQU-n-F [00261] CLUQU-n-F [00262] CLUQU(1)-n-F [00263] CLP-V-n [00264] CDU-n-F [00265] DCU-n-F [00266] CGG-n-F [00267] CPZG-n-OT [00268] CC-nV-Vm [00269] CCP-Vn-m [00270] CCG-V-F [00271] CCP-nV-m [00272] CC-n-V [00273] CCQU-n-F [00274] CC-n-Vm [00275] CLUQU-n-F [00276] CPPC-nV-Vm [00277] CCQG-n-F [00278] CQU-n-F [00279] CP-1V-m [00280] CLP-n-T [00281] CLP-n-OT [00282] CP-2V-m [00283] CP-V2-m [00284] Dec-U-n-F [00285] CWCU-n-F [00286] CPGP-n-m [00287] CWCG-n-F [00288] CLU-n-F [00289] CCOC-n-m [00290] CPTU-n-F [00291] GPTU-n-F [00292] PQU-n-F [00293] PUQU-n-F [00294] PGU-n-F [00295] CGZP-n-OT [00296] CCGU-n-F [00297] CCQG-n-F [00298] DPGU-n-F [00299] DPGU-n-OT [00300] CUQU-n-F [00301] CCCQU-n-F [00302] CGUQU-n-F [00303] CPGU-n-OT [00304] PYP-nF [00305] CPGU-n-F [00306] CCVC-n-m [00307] CCVC-n-V [00308] CCVC-n-IV [00309] CVCP-1V-OT [00310] GGP-n-Cl [00311] DLGU-n-F [00312] DLGU-n-m [00313] PP-nV-Vm [00314] PP-1-nVm [00315] CWCQU-n-F [00316] PPGU-n-F [00317] PGUQU-n-F [00318] PGUQU(1)-n-F [00319] GPQU-n-F [00320] MPP-n-F [00321] MUQU-n-F [00322] NUQU-n-F [00323] PGP-n-kVm [00324] PP-n-kVm [00325] PCH-nCl [00326] GP-n-Cl [00327] GGP-n-F [00328] PGIGI-n-F [00329] PGU-n-OXF [00330] CPU-n-OXF [00331] CCQU-n-F(1) [00332] DUQU-n-F(1) [00333] PUQU-n-F(1) [00334] APUQU-n-F(1) [00335] CDUQU-n-F(1) [00336] CPPQU-n-F(1) [00337] DGUQU-n-F(1) [00338] DPUQU-n-F(1) [00339] PGUQU-n-F(1) [00340] PYP-n-m

[0526] Particular preference is given to liquid-crystalline media which, besides the compounds of the formulae IA, IIA, IB and IIB, comprise at least one, two, three, four or more compounds from Table E.

Table F

[0527] Table F indicates possible dopants which are generally added to the liquid-crystalline media according to the invention. The liquid-crystalline media preferably comprise 0-10% by weight, in particular 0.01-5% by weight and particularly preferably 0.01-3% by weight of dopants.

TABLE-US-00006 [00341] C 15 [00342] CB 15 [00343] CM 21 [00344] R/S-811 [00345] CM 44 [00346] CM 45 [00347] CM 47 [00348] CN [00349] R/S-2011 [00350] R/S-3011 [00351] R/S-4011 [00352] R/S-5011 [00353] R/S-1011

Table G

[0528] Stabilisers, which can additionally be added, for example, to the liquid-crystalline media according to the invention in amounts of 0-10% by weight, are mentioned below.

TABLE-US-00007 [00354] [00355] [00356] [00357] n =1, 2, 3, 4, 5, 6 or 7 [00358] n =1, 2, 3, 4, 5, 6 or 7 [00359] [00360] n =1, 2, 3, 4, 5, 6 or 7 [00361] q =1, 2, 3, 4, 5, 6 or 7 [00362] [00363] [00364] [00365] [00366] [00367] [00368] [00369] [00370] [00371] [00372] [00373] [00374] [00375] [00376] [00377] [00378] [00379] [00380] [00381] [00382] [00383] [00384] [00385] [00386] q =1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Table H

[0529] Table H shows illustrative reactive mesogenic compounds (RMs) which can be used in the liquid-crystalline media in accordance with the present invention.

TABLE-US-00008 [00387] RM-1 [00388] RM-2 [00389] RM-3 [00390] RM-4 [00391] RM-5 [00392] RM-6 [00393] RM-7 [00394] RM-8 [00395] RM-9 [00396] RM-10 [00397] RM-11 [00398] RM-12 [00399] RM-13 [00400] RM-14 [00401] RM-15 [00402] RM-16 [00403] RM-17 [00404] RM-18 [00405] RM-19 [00406] RM-20 [00407] RM-21 [00408] RM-22 [00409] RM-23 [00410] RM-24 [00411] RM-25 [00412] RM-26 [00413] RM-27 [00414] RM-28 [00415] RM-29 [00416] RM-30 [00417] RM-31 [00418] RM-32 [00419] RM-33 [00420] RM-34 [00421] RM-35 [00422] RM-36 [00423] RM-37 [00424] RM-38 [00425] RM-39 [00426] RM-40 [00427] RM-41 [00428] RM-42 [00429] RM-43 [00430] RM-44 [00431] RM-45 [00432] RM-46 [00433] RM-47 [00434] RM-48 [00435] RM-49 [00436] RM-50 [00437] RM-51 [00438] RM-52 [00439] RM-53 [00440] RM-54 [00441] RM-55 [00442] RM-56 [00443] RM-57 [00444] RM-58 [00445] RM-59 [00446] RM-60 [00447] RM-61 [00448] RM-62 [00449] RM-63 [00450] RM-64 [00451] RM-65 [00452] RM-66 [00453] RM-67 [00454] RM-68 [00455] RM-69 [00456] RM-70 [00457] RM-71 [00458] RM-72 [00459] RM-73 [00460] RM-74 [00461] RM-75 [00462] RM-76 [00463] RM-77 [00464] RM-78 [00465] RM-79 [00466] RM-80 [00467] RM-81 [00468] RM-82 [00469] RM-83 [00470] RM-84 [00471] RM-85 [00472] RM-86 [00473] RM-87 [00474] RM-88 [00475] RM-89 [00476] RM-90 [00477] RM-91 [00478] RM-92 [00479] RM-93 [00480] RM-94 [00481] RM-95 [00482] RM-96 [00483] RM-97 [00484] RM-98 [00485] RM-99 [00486] RM-100 [00487] RM-101 [00488] RM-102 [00489] RM-103 [00490] RM-104 [00491] RM-105 [00492] RM-106 [00493] RM-107 [00494] RM-108 [00495] RM-109 [00496] RM-110 [00497] RM-111 [00498] RM-112 [00499] RM-113 [00500] RM-114 [00501] RM-115 [00502] RM-116 [00503] RM-117 [00504] RM-118 [00505] RM-119 [00506] RM-120 [00507] RM-121 [00508] RM-122 [00509] RM-123 [00510] RM-124 [00511] RM-125 [00512] RM-126 [00513] RM-127 [00514] RM-128 [00515] RM-129 [00516] RM-130 [00517] RM-131 [00518] RM-132 [00519] RM-133 [00520] RM-134 [00521] RM-135 [00522] RM-136 [00523] RM-137 [00524] RM-138 [00525] RM-139 [00526] RM-140 [00527] RM-141 [00528] RM-142 [00529] RM-143

[0530] In a preferred embodiment, the liquid-crystalline media according to the invention comprise one or more polymerizable compounds, preferably selected from the polymerizable compounds of the formulae RM-1 to RM-143. Of these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-64, RM-74, RM-76, RM-88, RM-102, RM-103, RM-109, RM-117, RM-120, RM-121 and RM-122 are particularly preferred.

Table I

[0531] Table I shows self-alignment additives for vertical alignment which can be used in LC media for SA-FFS, SA-HB-FFS and SA-XB-FFS displays according to the present invention, optionally together with the polymerizable compounds of formula I:

TABLE-US-00009 [00530] SA-1 [00531] SA-2 [00532] SA-3 [00533] SA-4 [00534] SA-5 [00535] SA-6 [00536] SA-7 [00537] SA-8 [00538] SA-9 [00539] SA-10 [00540] SA-11 [00541] SA-12 [00542] SA-13 [00543] SA-14 [00544] SA-15 [00545] SA-16 [00546] SA-17 [00547] SA-18 [00548] SA-19 [00549] SA-20 [00550] SA-21 [00551] SA-22 [00552] SA-23 [00553] SA-24 [00554] SA-25 [00555] SA-26 [00556] SA-27 [00557] SA-28 [00558] SA-29 [00559] SA-30 [00560] SA-31 [00561] SA-32 [00562] SA-33 [00563] SA-34

[0532] In a preferred embodiment, the LC media, SA-FFS, SA-HB-FFS and SA-XB-FFS displays according to the present invention comprise one or more SA additives selected from formulae SA-1 to SA-34, preferably from formulae SA-14 to SA-34, very preferably from formulae SA-20 to SA-28, most preferably of formula SA-20, in combination with one or more RMs of formula I.

[0533] The following mixture examples are intended to explain the invention without limiting it.

[0534] Above and below, percentage data denote percent by weight. All temperatures are indicated in degrees Celsius. m.p. denotes melting point, cl.p. =clearing point.

[0535] Furthermore, C=crystalline state, N=nematic phase, S=smectic phase and I=isotropic phase. The data between these symbols represent the transition temperatures. Furthermore, the following symbols are used [0536] V.sub.0 Freedericks threshold voltage, capacitive [V] at 20 C., [0537] V.sub.10 voltage [V] for 10% transmission, [0538] n.sub.e extraordinary refractive index measured at 20 C. and 589 nm, [0539] n.sub.0 ordinary refractive index measured at 20 C. and 589 nm, [0540] n optical anisotropy measured at 20 C. and 589 nm, [0541] .sub. dielectric susceptibility (or dielectric constant) perpendicular to the to the longitudinal axes of the molecules at 20 C. and 1 kHz, [0542] .sub. dielectric susceptibility (or dielectric constant) parallel to the to the longitudinal axes of the molecules at 20 C. and 1 kHz, [0543] dielectric anisotropy at 20 C. and 1 kHz, [0544] cl.p. or [0545] T(N,I) clearing point [ C.], [0546] v flow viscosity measured at 20 C. [mm.sup.2.Math.s.sup.1], [0547] .sub.1 rotational viscosity measured at 20 C. [mPa.Math.s], [0548] k.sub.11 elastic constant, splay deformation at 20 C. [pN], [0549] k.sub.22 elastic constant, twist deformation at 20 C. [pN], [0550] k.sub.33 elastic constant, bend deformation at 20 C. [pN], and [0551] LTS low-temperature stability of the phase [h] in bulk [0552] VHR voltage holding ratio.

[0553] All physical properties are determined in accordance with Merck Liquid Crystals, Physical Properties of Liquid Crystals, status November 1997, Merck KGaA, Germany, and apply for a temperature of 20 C., unless explicitly indicated otherwise.

Base Mixture M1

[0554] A nematic LC mixture is formulated as follows:

TABLE-US-00010 Composition Concen- tration, Nr. Compound wt.-% Properties 1 PGUQU-4-F 2.5 T(N, I) = 74.5 C. 2 PPGU-3-F 1.0 n (20 C., 589 nm) = 0.1255 3 CLP-3-T 6.0 .sub. (20 C., 1 kHz) = 5.2 4 CCP-V-1 4.0 .sub. (20 C., 1 kHz) = 2.6 5 PGP-1-2V 3.0 (20 C., 1 kHz) = 2.6 6 PGP-2-2V 6.0 k.sub.11 (20 C.) = 15.6 pN 7 PGU-2-F 3.0 k.sub.33 (20 C.) = 13.0 pN 8 PGU-3-F 2.0 V.sub.0 (V, 20 C.) = 2.60 V 9 CC-3-V 49.0 .sub.1 (20 C.) = 43 mPa .Math. s 10 CC-3-V1 6.5 LTS (20 C.) > 1 000 h 11 PP-1-2V1 2.0 12 PUS-3-2 9.0 13 PUS-2-2 6.0

Mixture Example 1 (Stabilised with Compound of Formula H-3-1)

[0555] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00011 Mixture M1 99.99% Compound of Formula H-3-1 100 ppm

[0556] Addition of 100 ppm of the compound of Formula H-3-1 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M1.

Base Mixture M2

[0557] A nematic LC mixture is formulated as follows:

TABLE-US-00012 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-2V1 3.0 T(N, I) = 73.6 C. 2 CC-3-V 37.5 n (20 C., 589 nm) = 0.1337 3 CC-3-V1 11.0 .sub. (20 C., 1 kHz) = 5.6 4 CLP-3-T 7.0 .sub. (20 C., 1 kHz) = 2.7 5 DGUQU-4-F 4.0 (20 C., 1 kHz) = 2.9 6 PGP-1-2V 3.5 k.sub.11 (20 C.) = 16.7 pN 7 PGP-2-2V 6.5 k.sub.33 (20 C.) = 13.9 pN 8 PGUQU-3-F 2.0 V.sub.0 (V, 20 C.) = 2.51 V 9 PP-1-2V1 10.0 .sub.1 (20 C.) = 48 mPa .Math. s 10 PPGU-3-F 1.0 LTS (20 C.) > 1 000 h 11 PUS-2-2 10.0 12 PUS-3-2 4.5

Mixture Example 2 (Stabilised with Compound of Formula H-3-1)

[0558] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00013 Mixture M2 99.999% Compound of Formula H-3-3 150 ppm

[0559] Addition of 150 ppm of the compound of Formula H-3-3 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M2.

Base Mixture M3

[0560] A nematic LC mixture is formulated as follows:

TABLE-US-00014 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 47.0 T(N, I) = 73.5 C. 2 CC-3-V1 4.0 n (20 C., 589 nm) = 0.1360 3 CLP-3-T 7.0 .sub. (20 C., 1 kHz) = 5.5 4 PGP-1-2V 3.0 .sub. (20 C., 1 kHz) = 2.7 5 PGP-2-2V 9.0 (20 C., 1 kHz) = 2.8 6 PGUQU-3-F 4.0 k.sub.11 (20 C.) = 15.5 pN 7 PGUQU-4-F 2.5 k.sub.33 (20 C.) = 13.5 pN 8 PP-1-2V1 7.5 V.sub.0 (V, 20 C.) = 2.50 V 9 PPGU-3-F 1.0 .sub.1 (20 C.) = 46 mPa .Math. s 10 PUS-3-2 10.0 LTS (20 C.) > 1 000 h 11 PUS-2-2 5.0

Mixture Example 3 (Stabilised with Compound of Formula H-3-7)

[0561] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00015 Mixture M3 99.999% Compound of Formula H-3-7 150 ppm

[0562] Addition of 150 ppm of the compound of Formula H-3-7 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M3.

Base Mixture M4

[0563] A nematic LC mixture is formulated as follows:

TABLE-US-00016 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 47.0 T(N, I) = 74 C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 0.1333 3 CLP-3-T 7.0 .sub. (20 C., 1 kHz) = 5.6 4 PGP-1-2V 2.0 .sub. (20 C., 1 kHz) = 2.6 5 PGP-2-2V 9.0 (20 C., 1 kHz) = 3.0 6 PGUQU-3-F 3.0 k.sub.11 (20 C.) = 15.8 pN 7 PGUQU-4-F 4.0 k.sub.33 (20 C.) = 13.2 pN 8 PP-1-2V1 6.0 V.sub.0 (V, 20 C.) = 2.43 V 9 PPGU-3-F 1.0 .sub.1 (20 C.) = 48 mPa .Math. s 10 PUS-3-2 10.0 LTS (20 C.) > 1 000 h 11 PUS-2-2 5.0

Mixture Example 4 (Stabilised with Compound of Formula H-3-8)

[0564] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00017 Mixture M4 99.999% Compound of 150 ppm Formula H-3-8

[0565] Addition of 150 ppm of the compound of Formula H-3-8 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M4.

Base Mixture M5

[0566] A nematic LC mixture is formulated as follows:

TABLE-US-00018 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 47.0 T(N, I) = 71.5 C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 0.1341 3 CLP-3-T 5.0 .sub. (20 C., 1 kHz) = 5.7 4 PGP-1-2V 2.0 .sub. (20 C., 1 kHz) = 2.7 5 PGP-2-2V 5.0 (20 C., 1 kHz) = 3.0 6 CDUQU-3-F 2.0 k.sub.11 (20 C.) = 15.1 pN 7 PGUQU-3-F 4.0 k.sub.33 (20 C.) = 12.7 pN 8 PGUQU-4-F 2.0 V.sub.0 (V, 20 C.) = 2.35 V 9 PP-1-2V1 6.0 .sub.1 (20 C.) = 46 mPa .Math. s 10 PPGU-3-F 1.0 LTS (20 C.) > 1 000 h 11 PUS-3-2 10.0 12 PUS-2-2 10.0

Mixture Example 5 (Stabilised with Compound of Formula H-3-10)

[0567] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00019 Mixture M5 99.999% Compound of 30 ppm Formula H-3-10

[0568] Addition of 30 ppm of the compound o Formula H-3-10 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M5.

Base Mixture M6

[0569] A nematic LC mixture is formulated as follows:

TABLE-US-00020 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 40.0 T(N, I) = 71.3 C. 2 CC-3-V1 8.0 n (20 C., 589 nm) = 0.1504 3 PGP-1-2V 4.0 .sub. (20 C., 1 kHz) = 5.7 4 PGP-2-2V 10.0 .sub. (20 C., 1 kHz) = 2.7 5 PGUQU-3-F 6.0 (20 C., 1 kHz) = 3.0 6 PGUQU-4-F 4.0 k.sub.11 (20 C.) = 14.0 pN 7 PP-1-2V1 8.0 k.sub.33 (20 C.) = 12.5 pN 8 PUS-2-2 10.0 V.sub.0 (V, 20 C.) = 2.27 V 9 PUS-3-2 10.0 .sub.1 (20 C.) = 53 mPa .Math. s LTS (20 C.) > 1 000 h

Mixture Example 6 (Stabilised with Compound of Formula H-3-2)

[0570] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00021 Mixture M6 99.999% Compound of 20 ppm Formula H-3-2

[0571] Addition of 20 ppm of the compound of Formula H-3-2 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M6.

Base Mixture M7

[0572] A nematic LC mixture is formulated as follows:

TABLE-US-00022 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = 75.1 C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 0.1555 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 5.7 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 2.7 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 3.0 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = 16.1 pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = 12.2 pN 8 PGP-2-2V 9.0 V.sub.0 (V, 20 C.) = 2.45 V 9 PGUQU-3-F 3.0 .sub.1 (20 C.) = 59 mPa .Math. s 10 PP-1-2V1 8.0 LTS (20 C.) > 1 000 h 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 15.0

Mixture Example 7 (Stabilised with Compound of Formula H-3-4)

[0573] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00023 Mixture M7 99.999% Compound of 20 ppm Formula H-3-4

[0574] Addition of 20 ppm of the compound of Formula H-3-4 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M7.

Base Mixture M8

[0575] A nematic LC mixture is formulated as follows:

TABLE-US-00024 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 27.5 T(N, I) = 82.3 C. 2 CC-3-V1 9.0 n (20 C., 589 nm) = 0.1554 3 CCP-V-1 5.0 .sub. (20 C., 1 kHz) = 6.6 4 CCP-V2-1 5.0 .sub. (20 C., 1 kHz) = 2.7 5 CLP-3-T 3.0 (20 C., 1 kHz) = 3.9 6 CLP-V-1 3.0 k.sub.11 (20 C.) = 18.2 pN 7 DGUQU-4-F 5.0 k.sub.33 (20 C.) = 15.1 pN 8 PGUQU-3-F 4.5 V.sub.0 (V, 20 C.) = 2.27 V 9 PP-1-2V1 12.0 .sub.1 (20 C.) = 68 mPa .Math. s 10 PPGU-3-F 1.0 LTS (20 C.) > 1 000 h 11 PUS-3-2 20.0 12 PUS-3-V 5.0

Mixture Example 8 (Stabilised with Compound of Formula H-3-7)

[0576] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00025 Mixture M8 99.999% Compound of 120 ppm Formula H-3-7

[0577] Addition of 120 ppm of the compound of Formula H-3-7 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M8.

Base Mixture M9

[0578] A nematic LC mixture is formulated as follows:

TABLE-US-00026 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 44.0 T(N, I) = 75.2 C. 2 CLP-3-T 7.0 n (20 C., 589 nm) = 0.1514 3 PGP-2-2V 15.0 .sub. (20 C., 1 kHz) = 5.7 4 PGUQU-3-F 4.0 .sub. (20 C., 1 kHz) = 2.7 5 PGUQU-4-F 3.0 (20 C., 1 kHz) = 3.0 6 PP-1-2V1 10.0 k.sub.11 (20 C.) = 16.7 pN 7 PUS-3-2 12.0 k.sub.33 (20 C.) = 13.0 pN 8 PUS-3-V 5.0 V.sub.0 (V, 20 C.) = 2.48 V .sub.1 (20 C.) = 55 mPa .Math. s LTS (20 C.) > 1 000 h

Mixture Example 9 (Stabilised with Compound of Formula H-3-7)

[0579] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00027 Mixture M9 99.999% Compound of 100 ppm Formula H-3-7

[0580] Addition of 100 ppm of the compound of Formula H-3-7 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M9.

Base Mixture M10

[0581] A nematic LC mixture is formulated as follows:

TABLE-US-00028 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-2V1 5.0 T(N, I) = 73 C. 2 CC-3-V 35.5 n (20 C., 589 nm) = 0.1338 3 CC-3-V1 11.0 .sub. (20 C., 1 kHz) = 5.4 4 CLP-3-T 7.0 .sub. (20 C., 1 kHz) = 2.7 5 DGUQU-4-F 4.0 (20 C., 1 kHz) = 2.7 6 PGP-1-2V 5.5 k.sub.11 (20 C.) = 16.9 pN 7 PGUQU-3-F 1.5 k.sub.33 (20 C.) = 13.8 pN 8 PP-1-2V1 10.0 V.sub.0 (V, 20 C.) = 2.58 V 9 PPGU-3-F 1.0 .sub.1 (20 C.) = 49 mPa .Math. s 10 PUS-2-2 9.5 LTS (20 C.) > 1 000 h 11 PUS-3-2 5.0 12 PUS-4-5 5.0

Mixture Example 10 (Stabilised with Compound of Formula H-3-1)

[0582] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00029 Mixture M10 99.999% Compound of 100 ppm Formula H-3-1

[0583] Addition of 100 ppm of the compound of Formula H-3-1 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M10.

Base Mixture M11

[0584] A nematic LC mixture is formulated as follows:

TABLE-US-00030 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 28.0 T(N, I) = 105.5 C. 2 CC-3-V1 8.0 n (20 C., 589 nm) = 0.1255 3 CCP-V-1 15.0 .sub. (20 C., 1 kHz) = 6.4 4 CCP-V2-1 9.0 .sub. (20 C., 1 kHz) = 2.7 5 CCVC-3-V 5.0 (20 C., 1 kHz) = 3.7 6 PGP-2-2V 2.0 k.sub.11 (20 C.) = 18.0 pN 7 PP-1-2V1 1.0 k.sub.33 (20 C.) = 17.6 pN 8 PPGU-3-F 0.5 V.sub.0 (V, 20 C.) = 2.36 V 9 CDUQU-3-F 7.5 LTS (20 C.) > 1 000 h 10 DGUQU-4-F 4.0 11 PUS-3-2 10.0 12 PUS-5-5 10.0

Mixture Example 11 (Stabilised with Compound of Formula H-3-3)

[0585] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00031 Mixture M11 99.999% Compound of Formula H-3-3 100 ppm

[0586] Addition of 100 ppm of the compound of Formula H-3-3 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M11.

Base Mixture M12

[0587] A nematic LC mixture is formulated as follows:

TABLE-US-00032 Composition Concen- tration, Nr. Compound wt.-% Properties 1 PPGU-3-F 0.5 T(N, I) = 77 C. 2 CLP-3-T 6.0 n (20 C., 589 nm) = 0.1408 3 CCQU-3-F 5.0 .sub. (20 C., 1 kHz) = 6.0 4 CC-3-V 41.0 .sub. (20 C., 1 kHz) = 2.6 5 CC-3-V1 2.0 (20 C., 1 kHz) = 3.4 6 PUS-3-2 10.0 k.sub.11 (20 C.) = 16.6 pN 7 PUS-4-5 15.0 k.sub.33 (20 C.) = 11.6 pN 8 PUS-6-5 15.0 V.sub.0 (V, 20 C.) = 2.34 V 9 DGUQU-4-F 4.0 LTS (20 C.) > 1 000 h 10 APUQU-3-F 1.5

Mixture Example 12 (Stabilised with Compound of Formula H-3-3)

[0588] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00033 Mixture M12 99.999% Compound of Formula H-3-3 100 ppm

[0589] Addition of 100 ppm of the compound of Formula H-3-3 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M12.

Base Mixture M13

[0590] A nematic LC mixture is formulated as follows:

TABLE-US-00034 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 47.0 T(N, I) = 75.0 C. 2 CC-3-V1 4.0 n (20 C., 589 nm) = 0.1360 3 CLP-3-T 7.0 .sub. (20 C., 1 kHz) = 5.6 4 PGP-1-2V 3.0 .sub. (20 C., 1 kHz) = 2.7 5 PGP-2-2V 9.0 (20 C., 1 kHz) = 2.9 7 PGUQU-3-F 4.0 k.sub.11 (20 C.) = 16.0 pN 8 PGUQU-4-F 2.5 k.sub.33 (20 C.) = 13.8 pN 9 PP-1-2V1 7.5 .sub.1 (20 C.) = 50 mPa .Math. s 10 PPGU-3-F 1.0 LTS (20 C.) > 1 000 h 11 Compound 10.0 I-3-22-4 12 PUS-2-2 5.0

##STR00564##

Mixture Example 13 (Stabilised with Compound of Formula H-3-6)

[0591] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00035 Mixture M13 99.999% Compound of Formula H-3-6 10 ppm

[0592] Addition of 10 ppm of the compound of Formula H-3-6 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M13.

Base Mixture M14

[0593] A nematic LC mixture is formulated as follows:

TABLE-US-00036 Composition Concen- tration, Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = 75.5 C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 0.1555 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 5.7 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 2.7 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 3.0 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = 16.5 pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = 12.4 pN 8 PGP-2-2V 9.0 .sub.1 (20 C.) = 62 mPa .Math. s 9 PGUQU-3-F 3.0 LTS (20 C.) > 1 000 h 10 PP-1-2V1 8.0 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 7.0 14 Compound 8.0 I-3-22-4

Mixture Example 14 (Stabilised with Compound of Formula H-3-6)

[0594] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00037 Mixture M14 99.999% Compound of Formula H-3-6 10 ppm

[0595] Addition of 10 ppm of the compound of Formula H-3-6 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M14.

Base Mixture M15

[0596] A nematic LC mixture is formulated as follows:

TABLE-US-00038 Composition Concentration, Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = pN 8 PGP-2-2V 9.0 .sub.1 (20 C.) = mPa .Math. s 9 PGUQU-3-F 3.0 10 PP-1-2V1 8.0 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 7.0 14 Compound 8.0 I-4-1-3

##STR00565##

Mixture Example 15 (Stabilised with Compound of Formula H-3-5)

[0597] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00039 Mixture M15 99.999% Compound of Formula H-3-5 10 ppm

[0598] Addition of 10 ppm of the compound of Formula H-3-5 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M15.

Base Mixture M16

[0599] A nematic LC mixture is formulated as follows:

TABLE-US-00040 Composition Concentration, Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = pN 8 PGP-2-2V 9.0 .sub.1 (20 C.) = mPa .Math. s 9 PGUQU-3-F 3.0 10 PP-1-2V1 8.0 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 7.0 14 Compound 8.0 I-4-1-1

##STR00566##

Mixture Example 16 (Stabilised with Compound of Formula H-3-1)

[0600] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00041 Mixture M16 99.99% Compound of Formula H-3-1 100 ppm

[0601] Addition of 100 ppm of the compound of Formula H-3-1 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M16.

Base Mixture M17

[0602] A nematic LC mixture is formulated as follows:

TABLE-US-00042 Composition Concen- tration Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = 75.5 C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 0.1555 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 5.7 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 2.7 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 3.0 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = 16.5 pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = 12.4 pN 8 PGP-2-2V 9.0 .sub.1 (20 C.) = 62 mPa .Math. s 9 PGUQU-3-F 3.0 10 PP-1-2V1 8.0 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 7.0 14 Compound 8.0 I-3-1-1

##STR00567##

Mixture Example 17 (Stabilised with Compound of Formula H-3-3)

[0603] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00043 Mixture M17 99.99% Compound of Formula H-3-5 100 ppm

[0604] Addition of 100 ppm of the compound of Formula H-3-5 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M17.

Base Mixture M18

[0605] A nematic LC mixture is formulated as follows:

TABLE-US-00044 Composition Concentration, Nr. Compound wt.-% Properties 1 CC-3-V 29.0 T(N, I) = C. 2 CC-3-V1 6.0 n (20 C., 589 nm) = 3 CC-2-3 5.0 .sub. (20 C., 1 kHz) = 4 CC-3-5 6.0 .sub. (20 C., 1 kHz) = 5 DGUQU-4-F 2.5 (20 C., 1 kHz) = 6 DPGU-4-F 3.0 k.sub.11 (20 C.) = pN 7 PGP-1-2V 2.5 k.sub.33 (20 C.) = pN 8 PGP-2-2V 9.0 .sub.1 (20 C.) = mPa .Math. s 9 PGUQU-3-F 3.0 10 PP-1-2V1 8.0 11 PPGU-3-F 1.0 12 PUS-2-2 10.0 13 PUS-3-2 7.0 14 Compound 8.0 I-3-1-3

##STR00568##

Mixture Example 18 (Stabilised with Compound of Formula H-3-4)

[0606] A nematic LC mixture according to the invention is formulated as follows:

TABLE-US-00045 Mixture M6 99.999% Compound of Formula H-3-4 10 ppm

[0607] Addition of 10 ppm of the compound of Formula H-3-4 significantly improves the VHR.sub.100 after UV exposure compared with the non-stabilised mixture M18.