POLYMERISABLE COMPOUNDS AND THE USE THEREOF IN LIQUID-CRYSTAL DISPLAYS

Abstract

The present invention relates to polymerisable compounds, to processes and intermediates for the preparation thereof, to liquid-crystal (LC) media comprising them, and to the use of the polymerisable compounds and LC media for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the polymer sustained alignment type, or a stabilisers in LC media and LC displays.

Claims

1. A compound of formula I
P-Sp-A.sup.1-(Z.sup.1-A.sup.2).sub.z-RI wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings P a polymerisable group, Sp a spacer group or a single bond, A.sup.1, A.sup.2 an alicyclic, heterocyclic, aromatic or heteroaromatic group with 4 to 30 ring atoms, which may also contain fused rings, and is optionally substituted by one or more groups L or R, Z.sup.1 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, CHCF, CFCH, CC, CHCHCOO, OCOCHCH, CH.sub.2CH.sub.2COO, OCOCH.sub.2CH.sub.2, CR.sup.0R.sup.00, or a single bond, R.sup.0, R.sup.00 H or alkyl having 1 to 12 C atoms, R H, L or P-Sp-, L F, Cl, CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S, CO, COO, OCO, OCOO in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F or Cl, z 0, 1, 2 or 3, n1 1, 2, 3 or 4, characterized in that the compound contains at least one group Sp comprising an oxetane-3,3-diyl group.

2. The compound according to claim 1, characterized in that R denotes P-Sp-.

3. The compound according to claim 1, characterized in that P denotes acrylate or methacrylate.

4. The compound according to claim 1, characterized in that it contains one or more spacer groups Sp of formula ##STR00576## wherein S.sup.1 and S.sup.2 independently of each other denote alkylene with 1 to 12 C atoms, which is unsubstituted or mono- or polysubstituted by F or Cl, and in which one or more non-adjacent CH.sub.2 groups may each, independently of one another, be replaced by O, S, CO, COO, OCO or N(R.sup.0) in such a way that O and/or S atoms are not linked directly to one another, and R.sup.0 is H or alkyl having 1 to 12 C atoms.

5. The compound according to claim 1, characterized in that it contains one or more spacer groups Sp of formula SO ##STR00577## wherein X.sup.S is O, COO, OCO, NR.sup.0 or a single bond, R.sup.0 is H or alkyl having 1 to 12 C atoms, and s1 and s2 are independently of each other an integer from 1 to 12, and X.sup.S is not linked to a group P in formula I.

6. The compound according to claim 1, characterized in that it contains one or more spacer groups selected from the following subformulae ##STR00578## which are linked to a polymerisable group P via the methylene group at the right side.

7. The compound according to claim 1, characterized in that Z.sup.1 is a single bond.

8. The compound according to claim 1, characterized in that A.sup.1 and A.sup.2 denote benzene, naphthalene, phenanthrene, anthracene, dibenzofuran or dibenzothiophene, all of which are optionally substituted by one or more groups L or P-Sp-.

9. The compound according to claim 1, characterized in that A.sup.1-(Z.sup.1-A.sup.2).sub.z- is selected from the following formulae ##STR00579## wherein the benzene rings are optionally substituted by one or more groups L or P-Sp-.

10. The compound according to claim 1, characterized in that it is selected from the following subformulae: ##STR00580## ##STR00581## wherein P, Sp, R and L are as defined for formula I, r1, r3, r7 are independently of each other 0, 1, 2 or 3, r2 is 0, 1, 2, 3 or 4, r4, r5, r6 are independently of each other 0, 1 or 2, wherein at least one group Sp contains an oxetane-3,3-diyl group or is selected from formula S, SO or SO1-SO10 ##STR00582## wherein S.sup.1 and S.sup.2 independently of each other denote alkylene with 1 to 12 C atoms, which is unsubstituted or mono- or polysubstituted by F or Cl, and in which one or more non-adjacent CH.sub.2 groups may each, independently of one another, be replaced by O, S, CO, COO, OCO or N(R.sup.0) in such a way that O and/or S atoms are not linked directly to one another ##STR00583## wherein X.sup.S is O, COO, OCO, NR.sup.0 or a single bond, R.sup.0 is H or alkyl having 1 to 12 C atoms, and s1 and s2 are independently of each other an integer from 1 to 12, and X.sup.S is not linked to a group P ##STR00584## which are linked to a polymerisable group P via the methylene group at the right side.

11. The compound according to claim 1, characterized in that it is selected from the following subformulae: ##STR00585## ##STR00586## ##STR00587## ##STR00588## ##STR00589## ##STR00590## wherein P a polymerisable group, Sp a spacer group or a single bond, L F, Cl, CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S, CO, COO, OCO, OCOOin such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F or Cl, r1, r3, r7 are independently of each other 0, 1, 2 or 3, r2 is 0, 1, 2, 3 or 4, r4, r5, r6 are independently of each other 0, 1 or 2, and wherein at least one group Sp contains an oxetane-3,3-diyl group or is selected from formula S, SO or SO1-SO10 ##STR00591## wherein S.sup.1 and S.sup.2 independently of each other denote alkylene with 1 to 12 C atoms, which is unsubstituted or mono- or polysubstituted by F or Cl, and in which one or more non-adjacent CH.sub.2 groups may each, independently of one another, be replaced by O, S, CO, COO, OCO or N(R.sup.0) in such a way that O and/or S atoms are not linked directly to one another ##STR00592## wherein X.sup.S is O, COO, OCO, NR.sup.0 or a single bond, R.sup.0 is H or alkyl having 1 to 12 C atoms, and s1 and s2 are independently of each other an integer from 1 to 12, and X.sup.S is not linked to a group P ##STR00593## which are linked to a polymerisable group P via the methylene group at the right side.

12. A liquid crystal (LC) medium comprising one or more compounds formula I as defined in claim 1.

13. The LC medium of claim 12, characterized in that it comprises a polymerisable component A) comprising one or more compounds of formula I, and a liquid-crystalline LC component B) comprising one or more mesogenic or liquid-crystalline compounds.

14. The LC medium of claim 13, characterized in that component B) comprises one or more compounds of the formulae CY and/or PY: ##STR00594## in which the individual radicals have the following meanings: a denotes 1 or 2, b denotes 0 or 1, ##STR00595## denotes ##STR00596## R.sup.1 and R.sup.2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, Z.sup.x denotes CHCH, CH.sub.2O, OCH.sub.2, CF.sub.2O, OCF.sub.2, O, CH.sub.2, CH.sub.2CH.sub.2 or a single bond, preferably a single bond, L.sup.1-4 each, independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2.

15. The LC medium according to claim 13, characterized in that component B) comprises one or more compounds selected from the following formulae: ##STR00597## in which the individual radicals, on each occurrence identically or differently, each, independently of one another, have the following meaning: ##STR00598## R.sup.A1 alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, also one of the meanings of R.sup.A2, R.sup.A2 alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, Z.sup.x 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, L.sup.1-4 each, independently of one another, H, F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F or CHF.sub.2H, x 1 or 2, z 0 or 1.

16. The LC medium according to claim 13, characterized in that component B) comprises one or more compounds of the following formula: ##STR00599## in which the individual radicals have the following meanings: ##STR00600## denotes ##STR00601## denotes ##STR00602## R.sup.3 and R.sup.4 each, independently of one another, denote alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, Z.sup.y denotes 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 or a single bond.

17. The LC medium according to claim 12, characterized in that the compounds of formula I are polymerised.

18. A process of preparing an LC medium, comprising the steps of mixing one or more mesogenic or liquid-crystalline compounds, or a liquid-crystalline comprising one or more mesogenic or liquid-crystalline compounds, with one or more compounds of formula I as defined in claim 1, and optionally with further liquid-crystalline compounds and/or additives.

19. An LC display comprising one or more compounds of formula I as defined in claim 1.

20. The LC display of claim 19, which is a VA, IPS, UB-FFS, TN, OCB, FFS or posi-VA display.

21. The LC display of claim 20, which is a PSA type display.

22. The LC display of claim 21, which is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA or PS-TN display.

23. The LC display which is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA or PS-TN display, characterized in that it comprises two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the substrates a layer of an LC medium, comprising one or more compounds of formula I as defined in claim 1 and optionally one or more additional compounds that are polymerisable, wherein the compounds of formula I and the additional polymerisable compounds are polymerised between the substrates of the display.

24. A process for the production of an LC display which is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA or PS-TN display, the LC display, characterized in that it comprises two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the substrates a layer of an LC medium, comprising one or more compounds of formula I as defined in claim 1 and optionally one or more additional compounds that are polymerisable, wherein the compounds of formula I and the additional polymerisable compounds are polymerised between the substrates of the display, comprising the steps of providing an LC medium, comprising one or more compounds of formula I and optionally one or more additional compounds that are polymerisable, between the substrates of the display, and polymerising the compounds of formula I and the additional polymerisable compounds.

25. A compound selected from the following formulae ##STR00603## ##STR00604## wherein Sp a spacer group or a single bond, L F, Cl, CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S, CO, COO, OCO, OCOOin such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F or Cl, P a polymerisable group, r1, r3, r7 are independently of each other 0, 1, 2 or 3, r2 is 0, 1, 2, 3 or 4, r4, r5, r6 are independently of each other 0, 1 or 2, R denotes H or Pg-Sp, and Pg denotes OH, a protected hydroxyl group or a masked hydroxyl group.

26. A process for preparing a compound of formula I according to claim 1, by esterification of a compound, selected from the following formulae ##STR00605## ##STR00606## wherein Sp a spacer group or a single bond, L F, Cl, CN, P-Sp- or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S, CO, COO, OCO, OCOOin such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by P, F or Cl, P a polymerisable group, r1, r3, r7 are independently of each other 0, 1, 2 or 3, r2 is 0, 1, 2, 3 or 4, r4, r5, r6 are independently of each other 0, 1 or 2, R denotes H or Pg-Sp, and Pg denotes OH, a protected hydroxyl group or a masked hydroxyl group, using corresponding acids, acid derivatives, or halogenated compounds containing a group P, in the presence of a dehydrating reagent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0095] Unless stated otherwise, the term ultraviolet (UV) light means light in the wavelength region of 310-400 nm of the electromagnetic spectrum.

[0096] Unless stated otherwise, the compounds of formula I are preferably selected from achiral compounds.

[0097] As used herein, the terms active layer and switchable layer mean a layer in an electrooptical display, for example an LC display, that comprises one or more molecules having structural and optical anisotropy, like for example LC molecules, which change their orientation upon an external stimulus like an electric or magnetic field, resulting in a change of the transmission of the layer for polarized or unpolarized light.

[0098] As used herein, the terms tilt and tilt angle will be understood to mean a tilted alignment of the LC molecules of an LC medium relative to the surfaces of the cell in an LC display (here preferably a PSA display). The tilt angle here denotes the average angle (<90) between the longitudinal molecular axes of the LC molecules (LC director) and the surface of the plane-parallel outer plates which form the LC cell. A low value for the tilt angle (i.e. a large deviation from the 90 angle) corresponds to a large tilt here. A suitable method for measurement of the tilt angle is given in the examples. Unless indicated otherwise, tilt angle values disclosed above and below relate to this measurement method.

[0099] As used herein, the terms reactive mesogen and RM will be understood to mean a compound containing a mesogenic or liquid crystalline skeleton, and one or more functional groups attached thereto which are suitable for polymerisation and are also referred to as polymerisable group or P.

[0100] Unless stated otherwise, the term polymerisable compound as used herein will be understood to mean a polymerisable monomeric compound.

[0101] As used herein, the term low-molecular-weight compound will be understood to mean to a compound that is monomeric and/or is not prepared by a polymerisation reaction, as opposed to a polymeric compound or a polymer.

[0102] As used herein, the term unpolymerisable compound will be understood to mean a compound that does not contain a functional group that is suitable for polymerisation under the conditions usually applied for the polymerisation of the RMs.

[0103] The term mesogenic group as used herein is known to the person skilled in the art and described in the literature, and means a group which, due to the anisotropy of its attracting and repelling interactions, essentially contributes to causing a liquid-crystal (LC) phase in low-molecular-weight or polymeric substances. Compounds containing mesogenic groups (mesogenic compounds) do not necessarily have to have an LC phase themselves. It is also possible for mesogenic compounds to exhibit LC phase behaviour only after mixing with other compounds and/or after polymerisation. Typical mesogenic groups are, for example, rigid rod- or disc-shaped units. An overview of the terms and definitions used in connection with mesogenic or LC compounds is given in Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.

[0104] The term spacer group, hereinafter also referred to as Sp, as used herein is known to the person skilled in the art and is described in the literature, see, for example, Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. As used herein, the terms spacer group or spacer mean a flexible group, for example an alkylene group, which connects the mesogenic group and the polymerisable group(s) in a polymerisable mesogenic compound.

[0105] Above and below,

##STR00003##

[0106] denote a trans-1,4-cyclohexylene ring, and

##STR00004##

[0107] denote a 1,4-phenylene ring.

[0108] In a group

##STR00005##

the single bond shown between the two ring atoms can be attached to any free position of the benzene ring.

[0109] Above and below organic group denotes a carbon or hydrocarbon group.

[0110] Carbon group denotes a mono- or polyvalent organic group containing at least one carbon atom, where this either contains no further atoms (such as, for example, CC-) or optionally contains one or more further atoms, such as, for example, N, O, S, B, P, Si, Se, As, Te or Ge (for example carbonyl, etc.). The term hydrocarbon group denotes a carbon group which additionally contains one or more H atoms and optionally one or more heteroatoms, such as, for example, N, O, S, B, P, Si, Se, As, Te or Ge.

[0111] Halogen denotes F, Cl, Br or I.

[0112] CO, C(O) and C(O) denote a carbonyl group, i.e.

##STR00006##

[0113] O. denotes an oxygen free radical.

[0114] Oxetane-3-3-diyl means

##STR00007##

[0115] Above and below, an asterisk (*) means a chemical linkage to an adjacent group in a molecule.

[0116] A carbon or hydrocarbon group can be a saturated or unsaturated group. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. A carbon or hydrocarbon radical having more than 3 C atoms can be straight-chain, branched and/or cyclic and may also contain spiro links or condensed rings.

[0117] The terms alkyl, aryl, heteroaryl, etc., also encompass polyvalent groups, for example alkylene, arylene, heteroarylene, etc.

[0118] The term aryl denotes an aromatic carbon group or a group derived therefrom. The term heteroaryl denotes aryl as defined above, containing one or more heteroatoms, preferably selected from N, O, S, Se, Te, Si and Ge.

[0119] Preferred carbon and hydrocarbon groups are optionally substituted, straight-chain, branched or cyclic, alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having 1 to 40, preferably 1 to 20, very preferably 1 to 12, C atoms, optionally substituted aryl or aryloxy having 5 to 30, preferably 6 to 25, C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25, C atoms, wherein one or more C atoms may also be replaced by hetero atoms, preferably selected from N, O, S, Se, Te, Si and Ge.

[0120] Further preferred carbon and hydrocarbon groups are C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkenyl, C.sub.2-C.sub.20 alkynyl, C.sub.3-C.sub.20 allyl, C.sub.4-C.sub.20 alkyldienyl, C.sub.4-C.sub.20 polyenyl, C.sub.6-C.sub.20) cycloalkyl, C.sub.4-C.sub.15 cycloalkenyl, C.sub.6-C.sub.30 aryl, C.sub.6-C.sub.30 alkylaryl, C.sub.6-C.sub.30 arylalkyl, C.sub.6-C.sub.30 alkylaryloxy, C.sub.6-C.sub.30 arylalkyloxy, C.sub.2-C.sub.30 heteroaryl, C.sub.2-C.sub.30 heteroaryloxy.

[0121] Particular preference is given to C.sub.1-C.sub.12 alkyl, C.sub.2-C.sub.12 alkenyl, C.sub.2-C.sub.12 alkynyl, C.sub.6-C.sub.25 aryl and C.sub.2-C.sub.25 heteroaryl.

[0122] Further preferred carbon and hydrocarbon groups are straight-chain, branched or cyclic alkyl having 1 to 20, preferably 1 to 12, C atoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN and in which one or more non-adjacent CH.sub.2 groups may each be replaced, independently of one another, by C(R.sup.x)C(R.sup.x), CC, N(R.sup.x), O, S, CO, COO, OCO, OCOO in such a way that 0 and/or S atoms are not linked directly to one another.

[0123] R.sup.x preferably denotes H, F, Cl, CN, a straight-chain, branched or cyclic alkyl chain having 1 to 25 C atoms, in which, in addition, one or more non-adjacent C atoms may be replaced by O, S, CO, COO, OCO, OCOO and in which one or more H atoms may be replaced by F or Cl, or denotes an optionally substituted aryl or aryloxy group with 6 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group with 2 to 30 C atoms.

[0124] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, etc.

[0125] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.

[0126] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

[0127] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

[0128] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.

[0129] Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e. they can contain one ring (such as, for example, phenyl) or two or more rings, which may also be fused (such as, for example, naphthyl) or covalently bonded (such as, for example, biphenyl), or contain a combination of fused and linked rings. Heteroaryl groups contain one or more heteroatoms, preferably selected from O, N, S and Se.

[0130] Particular preference is given to mono-, bi- or tricyclic aryl groups having 6 to 25 C atoms and mono-, bi- or tricyclic heteroaryl groups having 5 to 25 ring atoms, which optionally contain fused rings and are optionally substituted. Preference is furthermore given to 5-, 6- or 7-membered aryl and heteroaryl groups, in which, in addition, one or more CH groups may be replaced by N, S or O in such a way that O atoms and/or S atoms are not linked directly to one another.

[0131] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1:3,1]terphenyl-2-yl, naphthyl, anthracene, binaphthyl, phenanthrene, 9,10-dihydro-phenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, etc.

[0132] Preferred heteroaryl groups are, for example, 5-membered rings, such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings, such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, or condensed groups, such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, purine, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazothiophene, or combinations of these groups.

[0133] The aryl and heteroaryl groups mentioned above and below may also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or further aryl or heteroaryl groups.

[0134] The (non-aromatic) alicyclic and heterocyclic groups encompass both saturated rings, i.e. those containing exclusively single bonds, and also partially unsaturated rings, i.e. those which may also contain multiple bonds. Heterocyclic rings contain one or more heteroatoms, preferably selected from Si, O, N, S and Se.

[0135] The (non-aromatic) alicyclic and heterocyclic groups can be monocyclic, i.e. contain only one ring (such as, for example, cyclohexane), or polycyclic, i.e. contain a plurality of rings (such as, for example, decahydronaphthalene or bicyclooctane). Particular preference is given to saturated groups. Preference is furthermore given to mono-, bi- or tricyclic groups having 5 to 25 ring atoms, which optionally contain fused rings and are optionally substituted. Preference is furthermore given to 5-, 6-, 7- or 8-membered carbocyclic groups, in which, in addition, one or more C atoms may be replaced by Si and/or one or more CH groups may be replaced by N and/or one or more non-adjacent CH.sub.2 groups may be replaced by O and/or S.

[0136] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups, such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, pyrrolidine, 6-membered groups, such as cyclohexane, silinane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine, 7-membered groups, such as cycloheptane, and fused groups, such as tetrahydronaphthalene, decahydronaphthalene, indane, bicyclo[1.1.1]-pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindane-2,5-diyl.

[0137] Preferred substituents are, for example, solubility-promoting groups, such as alkyl or alkoxy, electron-withdrawing groups, such as fluorine, nitro or nitrile, or substituents for increasing the glass transition temperature (Tg) in the polymer, in particular bulky groups, such as, for example, t-butyl or optionally substituted aryl groups.

[0138] Preferred substituents are, for example, 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, straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms, in which one or more H atoms may optionally be replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms, wherein R.sup.x denotes H, F, Cl, CN, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S-, CO, COO, OCO, OCOO in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P or P-Sp-, and

[0139] Y.sup.1 denotes halogen.

[0140] Substituted silyl or aryl preferably means substituted by halogen, CN, R.sup.0, OR.sup.0, COR.sup.0, CO-OR.sup.0, OCOR.sup.0 or OCO OR.sup.0, wherein R.sup.0 denotes H or alkyl with 1 to 20 C atoms.

[0141] Particularly preferred substituents are, for example, F, Cl, CN, NO.sub.2, 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, furthermore phenyl.

##STR00008##

[0142] is preferably

##STR00009##

[0143] in which L has one of the meanings indicated above.

[0144] The polymerisable 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.

[0145] Preferred groups P are selected from the group consisting of CH.sub.2CW.sup.1COO, CH.sub.2CW.sup.1CO,

##STR00010##

CH.sub.2CW.sup.2-(O).sub.k3, CW.sup.1CHCO-(O).sub.k3, CW.sup.1CHCO-NH-, CH.sub.2CW.sup.1CO-NH-, CH.sub.3CHCHO, (CH.sub.2CH).sub.2CH-OCO, (CH.sub.2CHCH.sub.2).sub.2CH-OCO, (CH.sub.2CH).sub.2CH-O, (CH.sub.2CHCH.sub.2).sub.2N-, (CH.sub.2CHCH.sub.2).sub.2N-CO, HOCW.sup.2W.sup.3, HSCW.sup.2W.sup.3, HW.sup.2N, HOCW.sup.2W.sup.3NH-, CH.sub.2CW.sup.1CO-NH-, CH.sub.2CH(COO).sub.k1-Phe-(O).sub.k2, CH.sub.2CH(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.e 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 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.

[0146] Very preferred groups P are selected from the group consisting of CH.sub.2CW.sup.1COO, CH.sub.2CW.sup.1CO,

##STR00011##

[0147] CH.sub.2CW.sup.2O, CH.sub.2CW.sup.2-, CW.sup.1CHCO-(O).sub.k3, CW.sup.1CHCO-NH-, CH.sub.2CW.sup.1CO-NH-, (CH.sub.2CH).sub.2CH-OCO, (CH.sub.2CHCH.sub.2).sub.2CH-OCO, (CH.sub.2CH).sub.2CH-O, (CH.sub.2CHCH.sub.2).sub.2N-, (CH.sub.2CHCH.sub.2).sub.2N-CO, CH.sub.2CW.sup.1CO-NH-, CH.sub.2CH(COO).sub.k1-Phe-(O).sub.k2, CH.sub.2CH(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, 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, 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.

[0148] Very particularly preferred groups P are selected from the group consisting of CH.sub.2CW.sup.1COO, in particular CH.sub.2CHCOO, CH.sub.2C(CH.sub.3)COO and CH.sub.2CFCOO, furthermore CH.sub.2CHO, (CH.sub.2CH.sub.2CHO-CO, (CH.sub.2CH).sub.2CHO,

##STR00012##

[0149] Further preferred polymerisable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate.

[0150] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp-X, so that the respective radical P-Sp conforms to the formula P-Sp-X, wherein [0151] Sp denotes linear or branched 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, [0152] X denotes O, S, CO, COO, OCO, OCOO, CO-N(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.2CY.sup.3, CC, CHCHCOO, OCOCHCH or a single bond, [0153] R.sup.0 and R.sup.00 each, independently of one another, denote H or alkyl having 1 to 20 C atoms, and [0154] Y.sup.2 and Y.sup.3 each, independently of one another, denote H, F, Cl or CN. [0155] X is preferably O, S, CO, COO, OCO, OCOO, CONR.sup.0, NR.sup.0CO, NR.sup.0CONR.sup.00 or a single bond.

[0156] Typical spacer groups Sp and -Sp-X are, for example, (CH.sub.2).sub.p1, (CH.sub.2).sub.p1O, (CH.sub.2).sub.p1O-CO, (CH.sub.2).sub.p1-COO, (CH.sub.2).sub.p1OCOO, (CH.sub.2CH.sub.2O).sub.qCH.sub.2CH, 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 above.

[0157] Particularly preferred groups Sp and -Sp-X are (CH.sub.2).sub.p1, (CH.sub.2).sub.p1O, (CH.sub.2).sub.p1O-CO, (CH.sub.2).sub.p1-COO, (CH.sub.2).sub.p1OCOO, in which p1 and q1 have the meanings indicated above.

[0158] Particularly preferred groups Sp are, in each case straight-chain, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methylimino-ethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0159] In a preferred embodiment of the invention the compounds of formula I and its subformulae contain a spacer group Sp that is substituted by one or more polymerisable groups P, so that the group Sp-P corresponds to Sp(P).sub.s, with s being 24 2 (branched polymerisable groups).

[0160] Preferred compounds of formula I according to this preferred embodiment are those wherein s is 2, i.e. compounds which contain a group Sp(P).sub.2. Very preferred compounds of formula I according to this preferred embodiment contain a group selected from the following formulae:

X-alkyl-CHPPS1

-X-alkyl-CH((CH.sub.2).sub.aaP)((CH.sub.2).sub.bbP)S2

-X-N((CH.sub.2).sub.aaP)((CH.sub.2).sub.bbP)S3

-X-alkyl-CHPCH.sub.2CH.sub.2PS4

-X-alkyl-C(CH.sub.2P)(CH.sub.2P)C.sub.aaH.sub.2aa+1S5

-X-alkyl-CHPCH.sub.2PS6

-X-alkyl-CPP-C.sub.aaH.sub.2aa+1S7

-X-alkyl-CHPCHP-C.sub.aaH.sub.2aa+1S8

[0161] in which P is as defined in formula I, [0162] alkyl denotes a single bond or straight-chain or branched alkylene having 1 to 12 C atoms which is unsubstituted or mono- or polysubstituted by F, Cl or CN and in which one or more non-adjacent CH.sub.2 groups may each, independently of one another, be replaced byC(R.sup.0)C(R.sup.0), CC, N(R.sup.0), O, S, CO, COO, OCO, OCOO in such a way that 0 and/or S atoms are not linked directly to one another, where R.sup.0 has the meaning indicated above, [0163] aa and bb each, independently of one another, denote 0, 1, 2, 3, 4, 5 or 6, [0164] X has one of the meanings indicated for X, and is preferably O, CO, SO.sub.2, OCO, COO or a single bond.

[0165] Preferred spacer groups Sp(P).sub.2 are selected from formulae S1, S2 and S3.

[0166] Very preferred spacer groups Sp(P).sub.2 are selected from the following subformulae:

-CHPPS1a

OCHPPS1b

CH.sub.2CHPPS1c

OCH.sub.2CHPPS1d

CH(CH.sub.2P)(CH.sub.2P)S2a

OCH(CH.sub.2P)(CH.sub.2P)S2b

CH.sub.2CH(CH.sub.2P)(CH.sub.2P)S2c

OCH.sub.2CH(CH.sub.2P)(CH.sub.2P)S2d

CONH((CH.sub.2).sub.2P)((CH.sub.2).sub.2P)S3a

[0167] In the compounds of formula I and its subformulae as described above and below, P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate.

[0168] Further preferred are compounds of formula I and its subformulae as described above and below, wherein all polymerisable groups P that are present in the compound have the same meaning, and very preferably denote acrylate or methacrylate, most preferably methacrylate.

[0169] In the compounds of formula I and its subformulae as described above and below, R preferably denotes P-Sp-.

[0170] Preferably the compounds of formula I contain one or more spacer groups Sp selected of formula S

##STR00013##

[0171] wherein S.sup.1 and S.sup.2 independently of each other denote alkylene with 1 to 12, preferably 1 to 6 C atoms, which is unsubstituted or mono- or polysubstituted by F or Cl, and in which one or more non-adjacent CH.sub.2 groups may each, independently of one another, be replaced by O, S, CO, COO, OCO- or N(R.sup.0) in such a way that O and/or S atoms are not linked directly to one another, and R.sup.0 is as defined in formula I.

[0172] Preferred spacer groups of formula S are those containing the divalent

[0173] moiety

##STR00014##

(oxetane-3,3-dimethylene-yl).

[0174] Further preferred spacer groups of formula S are those of formula SO

##STR00015##

[0175] wherein X.sup.S is O, COO, OCO, NR.sup.0 or a single bond, R.sup.0 is as defined in formula I and is preferably H or methyl, s1 and s2 are independently of each other an integer from 1 to 12, preferably an integer from 1 to 6, very preferably 1, 2 or 3, and X.sup.S is not linked to a group P.

[0176] Preferably in formula SO s11 and s21.

[0177] Very preferred spacer groups of formula SO are selected from the following subformulae

##STR00016##

[0178] which are linked to a polymerisable group P via the methylene group at the right side.

[0179] In the compounds of formula I, Z.sup.1 is preferably a single bond.

[0180] In the compounds of formula I, A.sup.1 and A.sup.2 preferably denote benzene, naphthalene, phenanthrene or anthracene, which is optionally substituted by one or more groups L or P-Sp-.

[0181] Preferably -A.sup.1-(Z.sup.1-A.sup.2).sub.z- in formula I denotes benzene, biphenylene, p-terphenylene (1,4-diphenylbenzene), m-terphenylene (1,3-diphenylbenzene), naphthylene, 2-phenyl-naphthylene, phenanthrene, anthracene, dibenzofuran or dibenzozthiophene, all of which are optionally substituted by one or more groups L or P-Sp-.

[0182] Very preferred groups -A.sup.1-(Z.sup.1-A.sup.2).sub.z- in formula I are selected from the following formulae

##STR00017##

[0183] wherein the benzene rings are optionally substituted by one or more groups L or P-Sp-.

[0184] In the compounds of formula I and its subformulae as described above and below, -A.sup.1-(Z.sup.1-A.sup.2).sub.z- is preferably selected from formulae A1, A2, A5, A8 and A9, very preferably from formulae A1, A2 and A5.

[0185] Preferred compounds of formula I are selected from the following subformulae

##STR00018## ##STR00019##

[0186] wherein P, Sp, R and L have the meanings given in formula I,

[0187] r1, r3, r7 are independently of each other 0, 1, 2 or 3,

[0188] r2 is 0, 1, 2, 3 or 4,

[0189] r4, r5, r6 are independently of each other 0, 1 or 2,

[0190] wherein at least one group Sp contains an oxetane-3,3-diyl group and is preferably selected from formula S, SO or SO1-SO10.

[0191] Preferred are compounds of formula I1-I7 wherein one of the two groups R is H and the other is P-Sp.

[0192] Further preferred are compounds of formula I1-I7 wherein both groups R denote H.

[0193] Further preferred are compounds of formula I1-I7 wherein both groups R denote P-Sp.

[0194] Very preferred are compounds of formula I1, I2 and I5.

[0195] Further preferred compounds of formula I and I1-I7 are selected from the following subformulae

##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##

[0196] wherein P, Sp, P(Sp).sub.2, L, r1-r7 have the meanings given in formula I or one of the preferred meanings as given above and below, and wherein at least one group Sp contains an oxetane-3,3-diyl group and is preferably selected from formula S, SO or SO01-SO10.

[0197] Preferably in formulae I1-2, I2-2, I3-2, I4-2, I5-2, I6-2, I6-4 and I7-2 the group Sp(P).sub.2 is selected from formulae S1 to S8 or S1a to S3a as defined above.

[0198] Further preferred compounds of formula I and its subformulae are selected from the following preferred embodiments, including any combinations thereof: [0199] z is 0, [0200] z is 1, 2 or 3, [0201] A.sup.1 and A.sup.2 are selected from benzene, naphthalene, phenanthrene and anthracene, each of which is optionally substituted by one or more groups L or P-Sp-, [0202] Z.sup.1 is a single bond, [0203] A.sup.1-(Z.sup.1-A.sup.2).sub.z- is selected from formulae A1, A2, A5, A8 and A9, very preferably form formulae A1, A2 and A5, [0204] All groups P in the compound have the same meaning, [0205] the compounds contain exactly two polymerisable groups (represented by the groups P), [0206] the compounds contain exactly three polymerisable groups (represented by the groups P), [0207] P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate, [0208] the compounds contain at least one, preferably exactly one, group PSp wherein Sp contains an oxetane-3-3-diyl group, [0209] the compounds contain at least one, preferably exactly one, group PSp wherein Sp is selected of formula S, SO or SO1-SO10, [0210] the compounds contain at least one, preferably exactly one, group PSp wherein Sp is selected of formulae SO1-SO6, [0211] Sp, when not containing an oxetane group, is a single bond, [0212] Sp, when being different from a single bond and not containing an oxetane group, is (CH.sub.2).sub.p2, (CH.sub.2).sub.p2O, (CH.sub.2).sub.p2COO, (CH.sub.2).sub.p2OCO, wherein p2 is 2, 3, 4, 5 or 6, and the O-atom or the CO-group, respectively, is connected to the group A.sup.1 or A.sup.2, [0213] Sp(P).sub.2 is selected from subformulae S1a-S3a, [0214] R denotes P-Sp-, [0215] R denotes P-Sp- and the group -A.sup.1-(Z.sup.1-A.sup.2).sub.z- is substituted by a, preferably one, group P-Sp-, [0216] R denotes P-Sp- and one of the groups Sp contains an oxetane-3,3-diyl group and the other is a single bond, [0217] R denotes P-Sp-, the group -A.sup.1-(Z.sup.1-A.sup.2).sub.z- is substituted by a, preferably one, group P-Sp-, and one of the groups Sp contains an oxetane-3,3-diyl group and the other two groups Sp each denote a single bond, [0218] R denotes P-Sp-, the group -A.sup.1-(Z.sup.1-A.sup.2).sub.z- is substituted by a, preferably one, group P-Sp-, and one of the groups Sp contains an oxetane-3,3-diyl group, one of the groups Sp denotes a single bond, and one of the groups Sp is (CH.sub.2).sub.p2, (CH.sub.2).sub.p2O, (CH.sub.2).sub.p2COO, (CH.sub.2).sub.p2OCO, wherein p2 is 2, 3, 4, 5 or 6, and the O-atom or the CO-group, respectively, is connected to the group A.sup.1 or A.sup.2, [0219] R does not denote or contain a polymerisable group, [0220] R does not denote or contain a polymerisable group and denotes straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH.sub.2-groups are optionally replaced by O, S, CO, COO, OCO, OCOO in such a manner that O- and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl or La, [0221] L denotes F, Cl or CN, [0222] L denotes P-Sp-, [0223] r1, r2 and r3 denote 0 or 1, [0224] r1, r2, r3, r4, r5 and r6 denote 0 or 1, [0225] one of r1 and r7 is 0 and the other is 1, [0226] r1 is 1, and r2 and r3 are 0, [0227] r3 is 1 and r1 and r2 are 0, [0228] one of r4 and r5 is 0 and the other is 1, [0229] r4 and r6 are 0 and r5 is 1, [0230] r1 and r4 are 0 and r3 is 1, [0231] r1 and r3 are 0 and r4 is 1, [0232] r3 and r4 are 0 and r1 is 1,

[0233] Very preferred compounds of formula I and its subformulae are selected from the following list:

##STR00026## ##STR00027##

[0234] wherein Me is methyl.

[0235] The invention furthermore relates to compounds of formula I11-I19

##STR00028## ##STR00029##

[0236] wherein Sp, L, r.sup.1-6 and q are as defined in formula I1-I9, R denotes H or Pg-Sp, and Pg denotes OH, a protected hydroxyl group or a masked hydroxyl group.

[0237] Preferred compounds of formula I11-I19 are selected from subformulae I1-1 to I9-2 as defined above, wherein P is replaced by Pg.

[0238] Suitable protected hydroxyl groups Pg are known to the person skilled in the art. Preferred protecting groups for hydroxyl groups are alkyl, alkoxyalkyl, acyl, alkylsilyl, arylsilyl and arylmethyl groups, especially 2-tetrahydropyranyl, methoxymethyl, methoxyethoxymethyl, acetyl, triisopropylsilyl, tert-butyl-dimethylsilyl or benzyl.

[0239] The term masked hydroxyl group is understood to mean any functional group that can be chemically converted into a hydroxyl group. Suitable masked hydroxyl groups Pg are known to the person skilled in the art.

[0240] The compounds of formula II are suitable as intermediates for the preparation of compounds of the formula I and its subformulae.

[0241] The invention further relates to the use of the compounds of formula II as intermediates for the preparation of compounds of the formula I and its subformulae.

[0242] The compounds and intermediates of the formulae I and II and sub-formulae thereof 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.

[0243] For example, compounds of formula I can be synthesised by esterification or etherification of the intermediates of formula II, wherein Pg denotes OH, using corresponding acids, acid derivatives, or halogenated compounds containing a polymerisable group P.

[0244] For example, acrylic or methacrylic esters can be prepared by esterification of the corresponding alcohols with acid derivatives like, for example, (meth)acryloyl chloride or (meth)acrylic anhydride in the presence of a base like pyridine or triethyl amine, and 4-(N,N-dimethylamino)pyridine (DMAP).

[0245] Alternatively the esters can be prepared by esterification of the alcohols with (meth)acrylic acid in the presence of a dehydrating reagent, for example according to Steglich with dicyclohexylcarbodiimide (DCC), N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (EDC) or N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride and DMAP.

[0246] Further suitable methods are shown in the examples.

[0247] For the production of PSA displays, the polymerisable compounds contained in the LC medium are polymerised or crosslinked (if one compound contains two or more polymerisable groups) by in-situ polymerisation in the LC medium between the substrates of the LC display, optionally while a voltage is applied to the electrodes.

[0248] 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.

[0249] A preferred PSA type LC display of the present invention comprises: [0250] a first substrate including a pixel electrode defining pixel areas, the pixel electrode being connected to a switching element disposed in each pixel area and optionally including a micro-slit pattern, and optionally a first alignment layer disposed on the pixel electrode, [0251] a second substrate including a common electrode layer, which may be disposed on the entire portion of the second substrate facing the first substrate, and optionally a second alignment layer, [0252] an LC layer disposed between the first and second substrates and including an LC medium comprising a polymerisable component A and a liquid crystal component B as described above and below, wherein the polymerisable component A may also be polymerised.

[0253] The first and/or second alignment layer controls the alignment direction of the LC molecules of the LC layer. For example, in PS-VA displays the alignment layer is selected such that it imparts to the LC molecules homeotropic (or vertical) alignment (i.e. perpendicular to the surface) or tilted alignment. Such an alignment layer may for example comprise a polyimide, which may also be rubbed, or may be prepared by a photoalignment method.

[0254] The LC layer with the LC medium can be deposited between the substrates of the display by methods that are conventionally used by display manufacturers, for example the so-called one-drop-filling (ODF) method. The polymerisable component of the LC medium is then polymerised for example by UV photopolymerisation. The polymerisation can be carried out in one step or in two or more steps.

[0255] The PSA display may comprise further elements, like a colour filter, a black matrix, a passivation layer, optical retardation layers, transistor elements for addressing the individual pixels, etc., all of which are well known to the person skilled in the art and can be employed without inventive skill.

[0256] The electrode structure can be designed by the skilled person depending on the individual display type. For example for PS-VA displays a multi-domain orientation of the LC molecules can be induced by providing electrodes having slits and/or bumps or protrusions in order to create two, four or more different tilt alignment directions.

[0257] Upon polymerisation the polymerisable compounds form a crosslinked polymer, which causes a certain pretilt of the LC molecules in the LC medium. Without wishing to be bound to a specific theory, it is believed that at least a part of the crosslinked polymer, which is formed by the polymerisable compounds, will phase-separate or precipitate from the LC medium and form a polymer layer on the substrates or electrodes, or the alignment layer provided thereon. Microscopic measurement data (like SEM and AFM) have confirmed that at least a part of the formed polymer accumulates at the LC/substrate interface.

[0258] The polymerisation can be carried out in one step. It is also possible firstly to carry out the polymerisation, optionally while applying a voltage, in a first step in order to produce a pretilt angle, and subsequently, in a second polymerisation step without an applied voltage, to polymerise or crosslink the compounds which have not reacted in the first step (end curing).

[0259] Suitable and preferred polymerisation methods are, for example, thermal or photopolymerisation, preferably photopolymerisation, in particular UV induced photopolymerisation, which can be achieved by exposure of the polymerisable compounds to UV radiation.

[0260] Optionally one or more polymerisation initiators are added to the LC medium. Suitable conditions for the polymerisation and suitable types and amounts of initiators are known to the person skilled in the art and are described in the literature. Suitable for free-radical polymerisation are, for example, the commercially available photoinitiators Irgacure651, Irgacurel84, Irgacure907, Irgacure369 or Darocure1173 (Ciba AG). If a polymerisation initiator is employed, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

[0261] The polymerisable compounds according to the invention are also suitable for polymerisation without an initiator, which is accompanied by considerable advantages, such, for example, lower material costs and in particular less contamination of the LC medium by possible residual amounts of the initiator or degradation products thereof. The polymerisation can thus also be carried out without the addition of an initiator. In a preferred embodiment, the LC medium thus does not contain a polymerisation initiator.

[0262] The LC medium may also comprise one or more stabilisers in order to prevent undesired spontaneous polymerisation of the RMs, for example during storage or transport. Suitable types and amounts of stabilisers are known to the person skilled in the art and are described in the literature. Particularly suitable are, for example, the commercially available stabilisers from the Irganox series (Ciba AG), such as, for example, Irganox 1076. If stabilisers are employed, their proportion, based on the total amount of RMs or the polymerisable component (component A), is preferably 10-500,000 ppm, particularly preferably 50-50,000 ppm.

[0263] The compounds of formula I do in particular show good UV absorption in, and are therefore especially suitable for, a process of preparing a PSA display including one or more of the following features: [0264] the polymerisable medium is exposed to UV light in the display in a 2-step process, including a first UV exposure step (UV-1 step) to generate the tilt angle, and a second UV exposure step (UV-2 step) to finish polymerization, [0265] the polymerisable medium is exposed to UV light in the display generated by an energy-saving UV lamp (also known as green UV lamps). These lamps are characterized by a relative low intensity ( 1/100- 1/10 of a conventional UV1 lamp) in their absorption spectra from 300-380 nm, and are preferably used in the UV2 step, but are optionally also used in the UV1 step when avoiding high intensity is necessary for the process. [0266] the polymerisable medium is exposed to UV light in the display generated by a UV lamp with a radiation spectrum that is shifted to longer wavelengths, preferably 340 nm or more, to avoid short UV light exposure in the PS-VA process.

[0267] Both using lower intensity and a UV shift to longer wavelengths protect the organic layer against damage that may be caused by the UV light.

[0268] A preferred embodiment of the present invention relates to a process for preparing a PSA display as described above and below, comprising one or more of the following features: [0269] the polymerisable LC medium is exposed to UV light in a 2-step process, including a first UV exposure step (UV-1 step) to generate the tilt angle, and a second UV exposure step (UV-2 step) to finish polymerization, [0270] the polymerisable LC medium is exposed to UV light generated by a UV lamp having an intensity of from 0.5 mW/cm.sup.2 to 10 mW/cm.sup.2 in the wavelength range from 300-380 nm, preferably used in the UV2 step, and optionally also in the UV1 step, [0271] the polymerisable LC medium is exposed to UV light having a wavelength of 340 nm or more, and preferably 400 nm or less.

[0272] This preferred process can be carried out for example by using the desired UV lamps or by using a band pass filter and/or a cut-off filter, which are substantially transmissive for UV light with the respective desired wavelength(s) and are substantially blocking light with the respective undesired wavelengths. For example, when irradiation with UV light of wavelengths of 300-400 nm is desired, UV exposure can be carried out using a wide band pass filter being substantially transmissive for wavelengths 300 nm<<400 nm. When irradiation with UV light of wavelength of more than 340 nm is desired, UV exposure can be carried out using a cut-off filter being substantially transmissive for wavelengths >340 nm.

[0273] Substantially transmissive means that the filter transmits a substantial part, preferably at least 50% of the intensity, of incident light of the desired wavelength(s). Substantially blocking means that the filter does not transmit a substantial part, preferably at least 50% of the intensity, of incident light of the undesired wavelengths. Desired (undesired) wavelength e.g. in case of a band pass filter means the wavelengths inside (outside) the given range of , and in case of a cut-off filter means the wavelengths above (below) the given value of .

[0274] This preferred process enables the manufacture of displays by using longer UV wavelengths, thereby reducing or even avoiding the hazardous and damaging effects of short UV light components.

[0275] UV radiation energy is in general from 6 to 100 J, depending on the production process conditions.

[0276] Preferably an LC medium according to the present invention for use in PSA displays does essentially consist of a polymerisable component A), or one or more compounds of formula I, and an LC component B), or LC host mixture, as described above and below. However, the LC medium may additionally comprise one or more further components or additives, preferably selected from the list including but not limited to co-monomers, chiral dopants, polymerisation initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricating agents, dispersing agents, hydrophobing agents, adhesive agents, flow improvers, defoaming agents, deaerators, diluents, reactive diluents, auxiliaries, colourants, dyes, pigments and nanoparticles.

[0277] Particular preference is given to LC media comprising one, two or three compounds of formula I.

[0278] Preference is furthermore given to LC media in which the polymerisable component A) comprises exclusively compounds of formula I.

[0279] Preference is furthermore given to LC media in which the liquid-crystalline component B) or the LC host mixture has a nematic LC phase, and preferably has no chiral liquid crystal phase.

[0280] The LC component B), or LC host mixture, is preferably a nematic LC mixture.

[0281] Preference is furthermore given to achiral compounds of formula I, and to LC media in which the compounds of component A and/or B are selected exclusively from the group consisting of achiral compounds.

[0282] Preferably the proportion of the polymerisable component A) in the LC medium is from >0 to <5%, very preferably from >0 to <1%, most preferably from 0.01 to 0.5%.

[0283] Preferably the proportion of compounds of formula I in the LC medium is from >0 to <5%, very preferably from >0 to <1%, most preferably from 0.01 to 0.5%.

[0284] Preferably the proportion of the LC component B) in the LC medium is from 95 to <100%, very preferably from 99 to <100%.

[0285] In a preferred embodiment the polymerisable compounds of the polymerisable component B) are exclusively selected from formula I.

[0286] In another preferred embodiment the polymerisable component B) comprises, in addition to the compounds of formula I, one or more further polymerisable compounds (co-monomers), preferably selected from RMs.

[0287] Suitable and preferred mesogenic comonomers are selected from the following formulae:

##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034##

[0288] in which the individual radicals have the following meanings: [0289] P.sup.1, P.sup.2 and P.sup.3 each, independently of one another, denote an acrylate or methacrylate group, [0290] Sp.sup.1, Sp.sup.2 and Sp.sup.3 each, independently of one another, denote a single bond or a spacer group having one of the meanings indicated above and below for Sp, and particularly preferably denote (CH.sub.2).sub.p1-, (CH.sub.2).sub.p1O, (CH.sub.2).sub.p1-COO, (CH.sub.2).sub.p1OCO or (CH.sub.2).sub.p1OCOO, in which p1 is an integer from 1 to 12, 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 Ra, [0291] R.sup.aa denotes 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.1-Sp.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), [0292] R.sup.0, R.sup.00 each, independently of one another and identically or differently on each occurrence, denote H or alkyl having 1 to 12 C atoms, [0293] R.sup.y and R.sup.z each, independently of one another, denote H, F, CH.sub.3 or CF.sub.3, [0294] X.sup.1, X.sup.2 and X.sup.3 each, independently of one another, denote COO, OCO or a single bond, [0295] Z.sup.1 denotes O, CO, C(R.sup.yR.sup.z) or CF.sub.2CF.sub.2, [0296] Z.sup.2 and Z.sup.3 each, independently of one another, denote 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, [0297] L on each occurrence, identically or differently, denotes F, Cl, CN or straight-chain or branched, optionally mono- or poly-fluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, preferably F, [0298] L and L each, independently of one another, denote H, F or Cl, [0299] r denotes 0, 1, 2, 3 or 4, [0300] s denotes 0, 1, 2 or 3, [0301] t denotes 0, 1 or 2, [0302] x denotes 0 or 1.

[0303] Especially preferred are compounds of formulae M2, M13, M17, M22, M23, M24 and M30.

[0304] Further preferred are trireactive compounds M15 to M30, in particular M17, M18, M19, M22, M23, M24, M25, M26, M30 and M31.

[0305] In the compounds of formulae M1 to M31 the group

##STR00035##

is preferably

##STR00036##

[0306] 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.s 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 oder OCF.sub.3, especially F or CH.sub.3.

[0307] In another preferred embodiment of the invention the LC medium does not contain any polymerisable compounds other than the compounds of formula I.

[0308] If the compounds of formula I are used as stabilisers, their proportion in the LC medium according to the invention is preferably from >0 to 1000 ppm, particularly preferably from 100 to 750 ppm, very particularly preferably from 300 to 600 ppm.

[0309] Further to the compounds of formula I the LC medium may also comprise one or more additional stabilisers. Suitable additional stabilisers are, for example, the commercially available stabilisers from the Irganox series (Ciba AG), like, for example, Irganox 1076, or the stabilisers selected from Table C below. If additional stabilisers are employed, their proportion in the LC medium is preferably 10-1000 ppm, particularly preferably 50-500 ppm.

[0310] Besides the compounds of formula I and the optional further polymerisable compounds described above, the LC media for use in the LC displays according to the invention comprise an LC mixture (host mixture) comprising one or more, preferably two or more LC compounds which are selected from low-molecular-weight compounds that are unpolymerisable. These LC compounds are selected such that they stable and/or unreactive to a polymerisation reaction under the conditions applied to the polymerisation of the polymerisable compounds.

[0311] In principle, any LC mixture which is suitable for use in conventional displays is suitable as host mixture. Suitable LC mixtures are known to the person skilled in the art and are described in the literature, for example mixtures in VA displays in EP 1 378 557 A1 and mixtures for OCB displays in EP 1 306 418 A1 and DE 102 24 046 A1.

[0312] The compounds of formula I are especially suitable for use in an LC host mixture that comprises one or more mesogenic or LC compounds comprising an alkenyl group (hereinafter also referred to as alkenyl compounds), wherein said alkenyl group is stable to a polymerisation reaction under the conditions used for polymerisation of the compounds of formula I and of the other polymerisable compounds contained in the LC medium. Compared to RMs known from prior art the compounds of formula I do in such an LC host mixture exhibit improved properties, like solubility, reactivity or capability of generating a tilt angle.

[0313] Thus, in addition to the compounds of formula I, the LC medium according to the present invention comprises one or more mesogenic or liquid crystalline compounds comprising an alkenyl group, (alkenyl compound), where this alkenyl group is preferably stable to a polymerisation reaction under the conditions used for the polymerisation of the compounds of formula I or of the other polymerisable compounds contained in the LC medium.

[0314] The alkenyl groups in the alkenyl compounds are preferably selected from straight-chain, branched or cyclic alkenyl, in particular having 2 to 25 C atoms, particularly preferably having 2 to 12 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 and/or Cl.

[0315] Preferred alkenyl groups are straight-chain alkenyl having 2 to 7 C atoms and cyclohexenyl, in particular ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, 1,4-cyclohexen-1-yl and 1,4-cyclohexen-3-yl.

[0316] The concentration of compounds containing an alkenyl group in the LC host mixture (i.e. without any polymerisable compounds) is preferably from 5% to 100%, very preferably from 20% to 60%.

[0317] Especially preferred are LC mixtures containing 1 to 5, preferably 1, 2 or 3 compounds having an alkenyl group.

[0318] The mesogenic and LC compounds containing an alkenyl group are preferably selected from formulae AN and AY as defined below.

[0319] Besides the compounds of formula I or the polymerisable component A) as described above, the LC media according to the present invention comprise an LC component B), or LC host mixture, comprising one or more, preferably two or more LC compounds which are selected from low-molecular-weight compounds that are unpolymerisable. These LC compounds are selected such that they stable and/or unreactive to a polymerisation reaction under the conditions applied to the polymerisation of the polymerisable compounds.

[0320] In a first preferred embodiment the LC medium contains an LC component B), or LC host mixture, based on compounds with negative dielectric anisotropy.

[0321] Such LC media are especially suitable for use in VA, IPS, UB-FFS, PS-VA, PS-IPS and PS-UB-FFS displays. Particularly preferred embodiments of such an LC medium are those of sections a)-z3) below: [0322] a) LC medium wherein the component B) or LC host mixture comprises one or more compounds selected from formulae CY and PY:

##STR00037## [0323] wherein [0324] a denotes 1 or 2, [0325] b denotes 0 or 1,

##STR00038##

[0326] denotes

##STR00039## [0327] R.sup.1 and R.sup.2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, preferably alkyl or alkoxy having 1 to 6 C atoms, [0328] Z.sup.x and Z.sup.y each, independently of one another, denote 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, [0329] L.sup.1-4 each, independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2. [0330] Preferably, 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. [0331] The compounds of the formula CY are preferably selected from the group consisting of the following sub-formulae:

##STR00040## ##STR00041## ##STR00042## ##STR00043## [0332] in which a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond. Alkenyl preferably denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0333] The compounds of the formula PY are preferably selected from the group consisting of the following sub-formulae:

##STR00044## ##STR00045## ##STR00046## [0334] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond. Alkenyl preferably denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0335] b) LC medium wherein the component B) or LC host mixture comprises one or more mesogenic or LC compounds comprising an alkenyl group (hereinafter also referred to as alkenyl compounds), wherein said alkenyl group is stable to a polymerisation reaction under the conditions used for polymerisation of the polymerisable compounds contained in the LC medium. [0336] Preferably the component B) or LC host mixture comprises one or more alkenyl compounds selected from formulae AN and AY

##STR00047## [0337] in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:

##STR00048## [0338] R.sup.A1 alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, also one of the meanings of R.sup.A2, [0339] R.sup.A2 alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, [0340] Z.sup.x 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, [0341] L.sup.1,2 H, F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F or CHF.sub.2H, preferably H, F or Cl, [0342] x 1 or 2, [0343] z 0 or 1. [0344] Preferred compounds of formula AN and AY are those wherein R.sup.A2 is selected from ethenyl, propenyl, butenyl, pentenyl, hexenyl and heptenyl. [0345] In a preferred embodiment the component B) or LC host mixture comprises one or more compounds of formula AN selected from the following sub-formulae:

##STR00049## [0346] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-7 C atoms. Alkenyl and alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0347] Preferably the component B) or LC host mixture comprises one or more compounds selected from formulae AN1, AN2, AN3 and AN6, very preferably one or more compounds of formula AN1. [0348] In another preferred embodiment the component B) or LC host mixture comprises one or more compounds of formula AN selected from the following sub-formulae:

##STR00050## [0349] in which m denotes 1, 2, 3, 4, 5 or 6, i denotes 0, 1, 2 or 3, and R.sup.b1 denotes H, CH.sub.3 or C.sub.2H.sub.5. [0350] In another preferred embodiment the component B) or LC host mixture comprises one or more compounds selected from the following sub-formulae:

##STR00051## [0351] Most preferred are compounds of formula AN1a2 and AN1a5. [0352] In another preferred embodiment the component B) or LC host mixture comprises one or more compounds of formula AY selected from the following sub-formulae:

##STR00052## ##STR00053## ##STR00054## ##STR00055## [0353] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, (O) denotes an O-atom or a single bond, and alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-7 C atoms. Alkenyl and alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0354] In another preferred embodiment the component B) or LC host mixture comprises one or more compounds of formula AY selected from the following sub-formulae:

##STR00056## [0355] in which m and n each, independently of one another, denote 1, 2, 3, 4, 5 or 6, and alkenyl denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0356] Preferably the proportion of compounds of formula AN and AY in the LC medium is from 2 to 70% by weight, very preferably from 5 to 60% by weight, most preferably from 10 to 50% by weight. [0357] Preferably the LC medium or LC host mixture contains 1 to 5, preferably 1, 2 or 3 compounds selected from formulae AN and AY. [0358] In another preferred embodiment of the present invention the LC medium comprises one or more compounds of formula AY14, very preferably of AY14a. The proportion of compounds of formula AY14 or AY14a in the LC medium is preferably 3 to 20% by weight. [0359] The addition of alkenyl compounds of formula AN and/or AY enables a reduction of the viscosity and response time of the LC medium. [0360] c) LC medium wherein the component B) or LC host mixture comprises one or more compounds of the following formula:

##STR00057## [0361] in which the individual radicals have the following meanings:

##STR00058##

[0362] denotes

##STR00059##

[0363] denotes

##STR00060## [0364] R.sup.3 and R.sup.4 each, independently of one another, denote alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCOor COO in such a way that O atoms are not linked directly to one another, [0365] Z.sup.y denotes 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. [0366] The compounds of the formula ZK are preferably selected from the group consisting of the following sub-formulae:

##STR00061## [0367] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl preferably denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0368] Especially preferred are compounds of formula ZK1. [0369] Particularly preferred compounds of formula ZK are selected from the following sub-formulae:

##STR00062## [0370] wherein the propyl, butyl and pentyl groups are straight-chain groups. [0371] Most preferred are compounds of formula ZK1a. [0372] d) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds of the following formula:

##STR00063## [0373] in which the individual radicals on each occurrence, identically or differently, have the following meanings: [0374] R.sup.5 and R.sup.6 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, preferably alkyl or alkoxy having 1 to 6 C atoms,

##STR00064##

[0375] denotes

##STR00065##

[0376] denotes

##STR00066##

[0377] and [0378] e denotes 1 or 2. [0379] The compounds of the formula DK are preferably selected from the group consisting of the following sub-formulae:

##STR00067## ##STR00068## [0380] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl preferably denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0381] e) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds of the following formula:

##STR00069## [0382] in which the individual radicals have the following meanings:

##STR00070##

[0383] denotes

##STR00071## [0384] with at least one ring F being different from cyclohexylene, [0385] f denotes 1 or 2, [0386] R.sup.1 and R.sup.2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, [0387] Z.sup.x denotes 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, [0388] L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2. [0389] Preferably, both radicals L.sup.1 and L.sup.2 denote F or one of the radicals L.sup.1 and L.sup.2 denotes F and the other denotes Cl. [0390] The compounds of the formula LY are preferably selected from the group consisting of the following sub-formulae:

##STR00072## ##STR00073## ##STR00074## [0391] in which R.sup.1 has the meaning indicated above, alkyl denotes a straight-chain alkyl radical having 1-6 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.4H.sub.9, n-C.sub.5H.sub.11, CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2. [0392] f) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of the following formulae:

##STR00075## [0393] in which alkyl denotes C.sub.1-6-alkyl, L.sup.x denotes H or F, and X denotes F, Cl, OCF.sub.3, OCHF.sub.2 or OCHCF.sub.2. Particular preference is given to compounds of the formula G1 in which X denotes F. [0394] g) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of the following formulae:

##STR00076## ##STR00077## [0395] in which R.sup.5 has one of the meanings indicated above for R.sup.1, alkyl denotes C.sub.1-6-alkyl, d denotes 0 or 1, and z and m each, independently of one another, denote an integer from 1 to 6. R.sup.5 in these compounds is particularly preferably C.sub.1-6-alkyl or -alkoxy or C.sub.2-6-alkenyl, d is preferably 1. The LC medium according to the invention preferably comprises one or more compounds of the above-mentioned formulae in amounts of >5% by weight. [0396] h) LC medium wherein component B) or the LC host mixture additionally comprises one or more biphenyl compounds selected from the group consisting of the following formulae:

##STR00078## [0397] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl and alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0398] The proportion of the biphenyls of the formulae B1 to B3 in the LC host mixture is preferably at least 3% by weight, in particular >5% by weight. [0399] The compounds of the formula B2 are particularly preferred. [0400] The compounds of the formulae B1 to B3 are preferably selected from the group consisting of the following sub-formulae:

##STR00079## [0401] in which alkyl* denotes an alkyl radical having 1-6 C atoms. The medium according to the invention particularly preferably comprises one or more compounds of the formulae B1a and/or B2c. [0402] i) LC medium wherein component B) or the LC host mixture additionally comprises one or more terphenyl compounds of the following formula:

##STR00080## [0403] in which R.sup.5 and R.sup.6 each, independently of one another, have one of the meanings indicated above, and

##STR00081## [0404] each, independently of one another, denote

##STR00082## [0405] 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. [0406] The compounds of the formula T are preferably selected from the group consisting of the following sub-formulae:

##STR00083## ##STR00084## ##STR00085## [0407] in which R denotes a straight-chain alkyl or alkoxy radical having 1-7 C atoms, R* denotes a straight-chain alkenyl radical having 2-7 C atoms, (O) denotes an oxygen atom or a single bond, and m denotes an integer from 1 to 6. R* preferably denotes CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0408] R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy. [0409] The LC host mixture according to the invention preferably comprises the terphenyls of the formula T and the preferred sub-formulae thereof in an amount of 0.5-30% by weight, in particular 1-20% by weight. [0410] Particular preference is given to compounds of the formulae T1, T2, T3 and T21. In these compounds, R preferably denotes alkyl, furthermore alkoxy, each having 1-5 C atoms. [0411] The terphenyls are preferably employed in LC media according to the invention if the n value of the mixture is to be >0.1. Preferred LC media comprise 2-20% by weight of one or more terphenyl compounds of the formula T, preferably selected from the group of compounds T1 to T22. [0412] k) LC medium wherein component B) or the LC host mixture additionally comprises one or more quaterphenyl compounds selected from the group consisting of the following formulae:

##STR00086## [0413] wherein [0414] R.sup.0 is alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, [0415] X.sup.Q is F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, [0416] L.sup.O1 to L.sup.Q6 independently of each other are H or F, with at least one of L.sup.Q1 to L.sup.Q6 being F. [0417] Preferred compounds of formula Q are those wherein R.sup.e denotes straight-chain alkyl with 2 to 6 C-atoms, very preferably ethyl, n-propyl or n-butyl. [0418] Preferred compounds of formula Q are those wherein L.sup.a and L.sup.a4 are F. Further preferred compounds of formula 0 are those wherein L.sup.Q3, L.sup.Q4 and one or two of L.sup.Q1 and L.sup.Q2 are F. [0419] Preferred compounds of formula Q are those wherein X.sup.Q denotes F or OCF.sub.3, very preferably F. [0420] The compounds of formula Q are preferably selected from the following subformulae

##STR00087## [0421] wherein R.sup.Q has one of the meanings of formula Q or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl. [0422] Especially preferred are compounds of formula Q1, in particular those wherein R.sup.Q is n-propyl. [0423] Preferably the proportion of compounds of formula Q in the LC host mixture is from >0 to s5% by weight, very preferably from 0.1 to 2% by weight, most preferably from 0.2 to 1.5% by weight. [0424] Preferably the LC host mixture contains 1 to 5, preferably 1 or 2 compounds of formula Q. [0425] The addition of quaterphenyl compounds of formula Q to the LC host mixture enables to reduce ODF mura, whilst maintaining high UV absorption, enabling quick and complete polymerisation, enabling strong and quick tilt angle generation, and increasing the UV stability of the LC medium. [0426] Besides, the addition of compounds of formula Q, which have positive dielectric anisotropy, to the LC medium with negative dielectric anisotropy allows a better control of the values of the dielectric constants .sub. and .sub., and in particular enables to achieve a high value of the dielectric constant .sub. while keeping the dielectric anisotropy constant, thereby reducing the kick-back voltage and reducing image sticking. [0427] l) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds of formula C:

##STR00088## [0428] wherein [0429] R.sup.C denotes alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, [0430] X.sup.C denotes F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, [0431] L.sup.C1, L.sup.C2 independently of each other denote H or F, with at least one of L.sup.C1 and L.sup.C2 being F. [0432] Preferred compounds of formula C are those wherein R.sup.C denotes straight-chain alkyl with 2 to 6 C-atoms, very preferably ethyl, n-propyl or n-butyl. [0433] Preferred compounds of formula C are those wherein L.sup.C1 and L.sup.C2 are F. [0434] Preferred compounds of formula C are those wherein X.sup.C denotes F or OCF.sub.3, very preferably F. [0435] Preferred compounds of formula C are selected from the following formula

##STR00089## [0436] wherein R.sup.C has one of the meanings of formula C or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl, very preferably n-propyl. [0437] Preferably the proportion of compounds of formula C in the LC host mixture is from >0 to 10% by weight, very preferably from 0.1 to 8% by weight, most preferably from 0.2 to 5% by weight. [0438] Preferably the LC host mixture contains 1 to 5, preferably 1, 2 or 3 compounds of formula C. [0439] The addition of compounds of formula C, which have positive dielectric anisotropy, to the LC medium with negative dielectric anisotropy allows a better control of the values of the dielectric constants .sub. and .sub. and in particular enables to achieve a high value of the dielectric constant .sub. while keeping the dielectric anisotropy constant, thereby reducing the kick-back voltage and reducing image sticking. Besides, the addition of compounds of formula C enables to reduce the viscosity and the response time of the LC medium. [0440] m) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of the following formulae:

##STR00090## [0441] in which R.sup.1 and R.sup.2 have the meanings indicated above and preferably each, independently of one another, denote straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms. [0442] Preferred media comprise one or more compounds selected from the formulae O1, O3 and O4. [0443] n) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds of the following formula:

##STR00091## [0444] in which

##STR00092##

[0445] denotes

##STR00093## [0446] R.sup.9 denotes H, CH.sub.3, C.sub.2H.sub.5 or n-C.sub.3H.sub.7, (F) denotes an optional fluorine substituent, and q denotes 1, 2 or 3, and R.sup.7 has one of the meanings indicated for R.sup.1, preferably in amounts of >3% by weight, in particular >5% by weight and very particularly preferably 5-30% by weight. [0447] Particularly preferred compounds of the formula FI are selected from the group consisting of the following sub-formulae:

##STR00094## [0448] in which R.sup.7 preferably denotes straight-chain alkyl, and R.sup.9 denotes CH.sub.3, C.sub.2H.sub.5 or n-C.sub.3H.sub.7. Particular preference is given to the compounds of the formulae FI1, FI2 and FI3. [0449] o) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of the following formulae:

##STR00095## [0450] in which R.sup.8 has the meaning indicated for R.sup.1, and alkyl denotes a straight-chain alkyl radical having 1-6 C atoms. [0451] p) LC medium wherein component B) or the LC host mixture additionally comprises one or more compounds which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, the compounds selected from the group consisting of the following formulae:

##STR00096## ##STR00097## [0452] in which [0453] R.sup.10 and R.sup.11 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, preferably alkyl or alkoxy having 1 to 6 C atoms, [0454] and R.sup.10 and R.sup.11 preferably denote straight-chain alkyl or alkoxy having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms, and [0455] Z.sup.1 and Z.sup.2 each, independently of one another, denote C.sub.2H.sub.4-, CHCH, (CH.sub.2).sub.4, (CH.sub.2).sub.30, O(CH.sub.2).sub.3-, CHCHCH.sub.2CH.sub.2, CH.sub.2CH.sub.2CHCH, CH.sub.2O, OCH.sub.2, COO, OCO, C.sub.2F.sub.4, CFCF, CFCH, CHCF, CH.sub.2 or a single bond. [0456] q) LC medium wherein component B) or the LC host mixture additionally comprises one or more difluorodibenzochromans and/or chromans of the following formulae:

##STR00098## [0457] in which [0458] R.sup.11 and R.sup.12 each, independently of one another, have one of the meanings indicated above for R.sup.11, [0459] ring M is trans-1,4-cyclohexylene or 1,4-phenylene, [0460] Z.sup.m C.sub.2H.sub.4, CH.sub.2O, OCH.sub.2, COO or OCO, [0461] c is 0, 1 or 2, [0462] preferably in amounts of 3 to 20% by weight, in particular in amounts of 3 to 15% by weight. [0463] Particularly preferred compounds of the formulae BC, CR and RC are selected from the group consisting of the following sub-formulae:

##STR00099## ##STR00100## ##STR00101## [0464] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, (O) denotes an oxygen atom or a single bond, c is 1 or 2, and alkenyl and alkenyl* each, [0465] independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl and alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0466] Very particular preference is given to LC host mixtures comprising one, two or three compounds of the formula BC-2. [0467] r) LC medium wherein component B) or the LC host mixture additionally comprises one or more fluorinated phenanthrenes and/or dibenzofurans of the following formulae:

##STR00102## [0468] in which R.sup.11 and R.sup.12 each, independently of one another, have one of the meanings indicated above for R.sup.11, b denotes 0 or 1, L denotes F, and r denotes 1, 2 or 3. [0469] Particularly preferred compounds of the formulae PH and BF are selected from the group consisting of the following sub-formulae:

##STR00103## [0470] in which R and R each, independently of one another, denote a straight-chain alkyl or alkoxy radical having 1-7 C atoms. [0471] s) LC medium wherein component B) or the LC host mixture additionally comprises one or more monocyclic compounds of the following formula

##STR00104## [0472] wherein [0473] R.sup.1 and R.sup.2 each, independently of one another, denote alkyl having 1 to 12 C atoms, where, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that O atoms are not linked directly to one another, preferably alkyl or alkoxy having 1 to 6 C atoms, [0474] L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F, CHF.sub.2. [0475] Preferably, 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, [0476] The compounds of the formula Y are preferably selected from the group consisting of the following sub-formulae:

##STR00105## [0477] in which, Alkyl and Alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, Alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, Alkenyl and Alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl and Alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-. [0478] Particularly preferred compounds of the formula Y are selected from the group consisting of the following sub-formulae:

##STR00106## [0479] wherein Alkoxy preferably denotes straight-chain alkoxy with 3, 4, or 5 C atoms. [0480] t) LC medium which, apart from the polymerisable compounds as described above and below, does not contain a compound which contains a terminal vinyloxy group (O-CHCH.sub.2). [0481] u) LC medium wherein component B) or the LC host mixture comprises 1 to 8, preferably 1 to 5, compounds of the formulae CY1, CY2, PY1 and/or PY2. The proportion of these compounds in the LC host mixture as a whole is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%. [0482] v) LC medium wherein component B) or the LC host mixture comprises 1 to 8, preferably 1 to 5, compounds of the formulae CY9, CY10, PY9 and/or PY10. The proportion of these compounds in the LC host mixture as a whole is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%. [0483] w) LC medium wherein component B) or the LC host mixture comprises 1 to 10, preferably 1 to 8, compounds of the formula ZK, in particular compounds of the formulae ZK1, ZK2 and/or ZK6. The proportion of these compounds in the LC host mixture as a whole is preferably 3 to 25%, particularly preferably 5 to 45%. The content of these individual compounds is preferably in each case 2 to 20%. [0484] x) LC medium in which the proportion of compounds of the formulae CY, PY and ZK in the LC host mixture as a whole is greater than 70%, preferably greater than 80%. [0485] y) LC medium in which the LC host mixture contains one or more compounds containing an alkenyl group, preferably selected from formulae AN and AY, very preferably selected from formulae AN1, AN3, AN6 and AY14, most preferably from formulae AN1a, AN3a, AN6a and AY14. The concentration of these compounds in the LC host mixture is preferably from 2 to 70%, very preferably from 3 to 55%. [0486] z) LC medium wherein component B) or the LC host mixture contains one or more, preferably 1 to 5, compounds selected of formula PY1-PY8, very preferably of formula PY2. The proportion of these compounds in the LC host mixture as a whole is preferably 1 to 30%, particularly preferably 2 to 20%. The content of these individual compounds is preferably in each case 1 to 20%. [0487] z1) LC medium wherein component B) or the LC host mixture contains one or more, preferably 1, 2 or 3, compounds selected from formulae T1, T2 and T5, very preferably from formula T2. The content of these compounds in the LC host mixture as a whole is preferably 1 to 20%. [0488] z2) LC medium in which the LC host mixture contains one or more compounds selected from formulae CY and PY, one or more compounds selected from formulae AN and AY, and one or more compounds selected from formulae T and Q. [0489] z3) LC medium in which the LC host mixture contains one or more, preferably 1, 2 or 3, compounds of formula BF1, and one or more, preferably 1, 2 or 3, compounds selected from formulae AY14, AY15 and AY16, very preferably of formula AY14. The proportion of the compounds of formula AY14-AY16 in the LC host mixture is preferably from 2 to 35%, very preferably from 3 to 30%. The proportion of the compounds of formula BF1 in the LC host mixture is preferably from 0.5 to 20%, very preferably from 1 to 15%. Further preferably the LC host mixture according to this preferred embodiment contains one or more, preferably 1, 2 or 3 compounds of formula T, preferably selected from formula T1, T2 and T5, very preferably from formula T2 or T5. The proportion of the compounds of formula T in the LC host mixture medium is preferably from 0.5 to 15%, very preferably from 1 to 10%.

[0490] In a second preferred embodiment the LC medium contains an LC host mixture based on compounds with positive dielectric anisotropy. Such LC media are especially suitable for use in TN, OCB, Posi-VA, IPS, FFS, PS-OCB-, PS-TN-, PS-Posi-VA-, PS-IPS- or PS-FFS-displays.

##STR00107##

[0491] in which the individual radicals have, independently of each other and on each occurrence identically or differently, the following meanings:

##STR00108##

[0492] each, independently of one another, and on each occurrence, identically or differently

##STR00109## [0493] R.sup.21, R.sup.31 each, independently of one another, alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, [0494] X.sup.0 F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, [0495] Z.sup.31 CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, COO, trans-CHCH, trans-CFCF-, CH.sub.2O or a single bond, preferably CH.sub.2CH.sub.2, COO, trans-CHCH or a single bond, particularly preferably COO, trans-CHCH or a single bond, [0496] L.sup.21, L.sup.22, L.sup.31, L.sup.32 each, independently of one another, H or F, [0497] g 0, 1, 2 or 3.

[0498] In the compounds of formula A and B, X.sup.0 is preferably F, Cl, CF.sub.3, CHF.sub.2, OCF.sub.3, OCHF.sub.2, OCFHCF.sub.3, OCFHCHF.sub.2, OCFHCHF.sub.2, OCF.sub.2CH.sub.3, OCF.sub.2CHF.sub.2, OCF.sub.2CHF.sub.2, OCF.sub.2CF.sub.2CHF.sub.2, OCF.sub.2CF.sub.2CHF.sub.2, OCFHCF.sub.2CF.sub.3, OCFHCF.sub.2CHF.sub.2, OCF.sub.2CF.sub.2CF.sub.3, OCF.sub.2CF.sub.2CCIF.sub.2, OCClFCF.sub.2CF.sub.3 or CHCF.sub.2, very preferably F or OCF.sub.3, most preferably F.

[0499] In the compounds of formula A and B, R.sup.21 and R.sup.31 are preferably selected from straight-chain alkyl or alkoxy with 1, 2, 3, 4, 5 or 6 C atoms, and straight-chain alkenyl with 2, 3, 4, 5, 6 or 7 C atoms.

[0500] In the compounds of formula A and B, g is preferably 1 or 2.

[0501] In the compounds of formula B, Z.sup.31 is preferably COO, trans-CHCH or a single bond, very preferably COO or a single bond.

[0502] Preferably component B) of the LC medium comprises one or more compounds of formula A selected from the group consisting of the following formulae:

##STR00110##

[0503] in which A.sup.21, R.sup.21, X.sup.0, L.sup.21 and L.sup.22 have the meanings given in formula A, L.sup.23 and L.sup.24 each, independently of one another, are H or F, and X.sup.0 is preferably F. Particularly preferred are compounds of formulae A1 and A2.

[0504] Particularly preferred compounds of formula A1 are selected from the group consisting of the following subformulae:

##STR00111##

[0505] in which R.sup.21, X.sup.0, L.sup.21 and L.sup.22 have the meaning given in formula A1, L.sup.23, L.sup.24, L.sup.25 and L.sup.26 are each, independently of one another, H or F, and X.sup.0 is preferably F.

[0506] Very particularly preferred compounds of formula A1 are selected from the group consisting of the following subformulae:

##STR00112##

[0507] In which R.sup.21 is as defined in formula A1.

[0508] Particularly preferred compounds of formula A2 are selected from the group consisting of the following subformulae:

##STR00113## ##STR00114##

[0509] in which R.sup.21, X.sup.0, L.sup.21 and L.sup.22 have the meaning given in formula A2, L.sup.23, L.sup.24, L.sup.25 and L.sup.26 each, independently of one another, are H or F, and X.sup.0 is preferably F.

[0510] Very particularly preferred compounds of formula A2 are selected from the group consisting of the following subformulae:

##STR00115## ##STR00116##

[0511] in which R.sup.21 and X.sup.0 are as defined in formula A2.

[0512] Particularly preferred compounds of formula A3 are selected from the group consisting of the following subformulae:

##STR00117##

[0513] in which R.sup.21, X.sup.0, L.sup.21 and L.sup.22 have the meaning given in formula A3, and X.sup.0 is preferably F.

[0514] Particularly preferred compounds of formula A4 are selected from the group consisting of the following subformulae:

##STR00118##

[0515] in which R.sup.21 is as defined in formula A4.

[0516] Preferably component B) of the LC medium comprises one or more compounds of formula B selected from the group consisting of the following formulae:

##STR00119##

[0517] in which g, A.sup.31, A.sup.32, R.sup.31, X.sup.0, L.sup.31 and L.sup.32 have the meanings given in formula B, and X.sup.0 is preferably F. Particularly preferred are compounds of formulae B1 and B2.

[0518] Particularly preferred compounds of formula B1 are selected from the group consisting of the following subformulae:

##STR00120##

[0519] in which R.sup.31, X.sup.0, L.sup.31 and L.sup.32 have the meaning given in formula B1, and X.sup.0 is preferably F.

[0520] Very particularly preferred compounds of formula B1a are selected from the group consisting of the following subformulae:

##STR00121##

[0521] in which R.sup.31 is as defined in formula B1.

[0522] Very particularly preferred compounds of formula B1 b are selected from the group consisting of the following subformulae:

##STR00122##

[0523] in which R.sup.31 is as defined in formula B1.

[0524] Particularly preferred compounds of formula B2 are selected from the group consisting of the following subformulae:

##STR00123## ##STR00124##

[0525] in which R.sup.31, X.sup.0, L.sup.31 and L.sup.32 have the meaning given in formula B2, L.sup.33, L.sup.34, L.sup.35 and L.sup.36 are each, independently of one another, H or F, and X.sup.0 is preferably F.

[0526] Very particularly preferred compounds of formula B2 are selected from the group consisting of the following subformulae:

##STR00125##

[0527] in which R.sup.31 is as defined in formula B2.

[0528] Very particularly preferred compounds of formula B2b are selected from the group consisting of the following subformulae

##STR00126##

[0529] in which R.sup.31 is as defined in formula B2.

[0530] Very particularly preferred compounds of formula B2c are selected from the group consisting of the following subformulae:

##STR00127##

[0531] in which R.sup.31 is as defined in formula B2.

[0532] Very particularly preferred compounds of formula B2d and B2c are selected from the group consisting of the following subformulae:

##STR00128##

[0533] in which R.sup.31 is as defined in formula B2.

[0534] Very particularly preferred compounds of formula B2f are selected from the group consisting of the following subformulae:

##STR00129##

[0535] in which R.sup.31 is as defined in formula B2.

[0536] Very particularly preferred compounds of formula B2g are selected from the group consisting of the following subformulae:

##STR00130##

[0537] in which R.sup.31 is as defined in formula B2.

[0538] Very particularly preferred compounds of formula B2h are selected from the group consisting of the following subformulae:

##STR00131##

[0539] in which R.sup.31 is as defined in formula B2.

[0540] Very particularly preferred compounds of formula B2i are selected from the group consisting of the following subformulae:

##STR00132##

[0541] in which R.sup.31 is as defined in formula B2.

[0542] Very particularly preferred compounds of formula B2k are selected from the group consisting of the following subformulae:

##STR00133##

[0543] in which R.sup.31 is as defined in formula B2.

[0544] Very particularly preferred compounds of formula B21 are selected from the group consisting of the following subformulae:

##STR00134##

[0545] in which R.sup.31 is as defined in formula B2.

[0546] Alternatively to, or in addition to, the compounds of formula B1 and/or B2 component B) of the LC medium may also comprise one or more compounds of formula B3 as defined above.

[0547] Particularly preferred compounds of formula B3 are selected from the group consisting of the following subformulae:

##STR00135##

[0548] in which R.sup.31 is as defined in formula B3.

[0549] Preferably component B) of the LC medium comprises, in addition to the compounds of formula A and/or B, one or more compounds of formula C

##STR00136##

[0550] in which the individual radicals have the following meanings:

##STR00137##

[0551] each, independently of one another, and on each occurrence, identically or differently

##STR00138## [0552] R.sup.41, R.sup.42 each, independently of one another, alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, [0553] Z.sup.41, Z.sup.42 each, independently of one another, CH.sub.2CH.sub.2, COO, trans-CHCH-, trans-CFCF-, CH.sub.2O, CF.sub.2O, CC or a single bond, preferably a single bond, [0554] h 0, 1, 2 or 3.

[0555] In the compounds of formula C, R.sup.41 and R.sup.42 are preferably selected from straight-chain alkyl or alkoxy with 1, 2, 3, 4, 5 or 6 C atoms, and straight-chain alkenyl with 2, 3, 4, 5, 6 or 7 C atoms.

[0556] In the compounds of formula C, h is preferably 0, 1 or 2.

[0557] In the compounds of formula C, Z.sup.41 and Z.sup.42 are preferably selected from COO, trans-CHCH and a single bond, very preferably from COO and a single bond.

[0558] Preferred compounds of formula C are selected from the group consisting of the following subformulae:

##STR00139## ##STR00140##

[0559] wherein R.sup.41 and R.sup.42 have the meanings given in formula C, and preferably denote each, independently of one another, alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy with 1 to 7 C atoms, or alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl with 2 to 7 C atoms.

[0560] Further preferably component B) of the LC medium comprises, in addition to the compounds of formula A and/or B, one or more compounds of formula D

##STR00141##

[0561] in which A.sup.41, A.sup.42, Z.sup.41, Z.sup.42, R.sup.41, R.sup.42 and h have the meanings given in formula C or one of the preferred meanings given above.

[0562] Preferred compounds of formula D are selected from the group consisting of the following subformulae:

##STR00142##

in which R.sup.41 and R.sup.42 have the meanings given in formula D and R.sup.41 preferably denotes alkyl bedeutet, and in formula D1 R.sup.42 preferably denotes alkenyl, particularly preferably (CH.sub.2).sub.2-CHCHCH.sub.3, and in formula D2 R.sup.42 preferably denotes alkyl, (CH.sub.2).sub.2-CHCH.sub.2 or (CH.sub.2).sub.2-CHCHCH.sub.3.

[0563] Further preferably component B) of the LC medium comprises, in addition to the compounds of formula A and/or B, one or more compounds of formula E containing an alkenyl group

##STR00143##

[0564] in which the individual radicals, on each occurrence identically or differently, each, independently of one another, have the following meaning:

##STR00144## [0565] R.sup.A1 alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, also one of the meanings of R.sup.A2, [0566] R.sup.A2 alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by O, CHCH, CO, OCO or COO in such a way that 0 atoms are not linked directly to one another, [0567] x 1 or 2.

[0568] R.sup.A2 is preferably straight-chain alkyl or alkoxy having 1 to 8 C atoms or straight-chain alkenyl having 2 to 7 C atoms.

[0569] Preferred compounds of formula E are selected from the following sub-formulae:

##STR00145## ##STR00146##

[0570] in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-7 C atoms. Alkenyl and alkenyl* preferably denote CH.sub.2CH, CH.sub.2CHCH.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.3-CHCH or CH.sub.3CHCH(CH.sub.2).sub.2-.

[0571] Very preferred compounds of the formula E are selected from the following sub-formulae:

##STR00147##

[0572] in which m denotes 1, 2, 3, 4, 5 or 6, i denotes 0, 1, 2 or 3, and R.sup.b1 denotes H, CH.sub.3 or C.sub.2H.sub.5.

[0573] Very particularly preferred compounds of the formula E are selected from the following sub-formulae:

##STR00148##

[0574] Most preferred are compounds of formula E1a2, E1a5, E3a1 and E6a1.

[0575] Further preferably component B) of the LC medium comprises, in addition to the compounds of formula A and/or B, one or more compounds of formula F

##STR00149##

[0576] in which the individual radicals have, independently of each other and on each occurrence identically or differently, the following meanings:

##STR00150##

[0577] denote

##STR00151## [0578] R.sup.21, R.sup.31 each, independently of one another, alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, [0579] X.sup.0 F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, [0580] Z.sup.21 CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, COO, trans-CHCH, trans-CFCF-, CH.sub.2O, CF.sub.2O, CC or a single bond, preferably CF.sub.2O, [0581] L.sup.21, L.sup.22, L.sup.23, L.sup.24 each, independently of one another, H or F, [0582] g 0, 1, 2 or 3.

[0583] Particularly preferred compounds of formula F are selected from the group consisting of the following formulae:

##STR00152##

[0584] in which R.sup.21, X.sup.0, L.sup.21 and L.sup.22 have the meaning given in formula F, L.sup.25 and L.sup.26 are each, independently of one another, H or F, and X.sup.0 is preferably F.

[0585] Very particularly preferred compounds of formula F1-F3 are selected from the group consisting of the following subformulae:

##STR00153##

[0586] In which R.sup.21 is as defined in formula F1.

[0587] The concentration of the compounds of formula A and B in the LC host mixture is preferably from 2 to 60%, very preferably from 3 to 45%, most preferably from 4 to 35%.

[0588] The concentration of the compounds of formula C and D in the LC host mixture is preferably from 2 to 70%, very preferably from 5 to 65%, most preferably from 10 to 60%.

[0589] The concentration of the compounds of formula E in the LC host mixture is preferably from 5 to 50%, very preferably from 5 to 35%.

[0590] The concentration of the compounds of formula F in the LC host mixture is preferably from 2 to 30%, very preferably from 5 to 20%.

[0591] Further preferred embodiments of this second preferred embodiment of the present invention are listed below, including any combination thereof. [0592] 2a) The LC host mixture comprises one or more compounds of formula A and/or B with high positive dielectric anisotropy, preferably with >15. [0593] 2b) The LC host mixture comprises one or more compounds selected from the group consisting of formulae A1a2, A1b1, A1d1, A1f1, A2a1, A2h1, A2l2, A2k1, B2h3, B2l1, F1a. The proportion of these compounds in the LC host mixture is preferably from 4 to 40%, very preferably from 5 to 35%. [0594] 2c) The LC host mixture comprises one or more compounds selected from the group consisting of formulae B2c1, B2c4, B2f4, C14. The proportion of these compounds in the LC host mixture is preferably from 4 to 40%, very preferably from 5 to 35%. [0595] 2d) The LC host mixture comprises one or more compounds selected from the group consisting of formulae C3, C4, C5, C9 and D2. The proportion of these compounds in the LC host mixture is preferably from 8 to 70%, very preferably from 10 to 60%. [0596] 2e) The LC host mixture comprises one or more compounds selected from the group consisting of formulae G1, G2 and G5, preferably G1a, G2a and G5a. The proportion of these compounds in the LC host mixture is preferably from 4 to 40%, very preferably from 5 to 35%. [0597] 2f) The LC host mixture comprises one or more compounds selected from the group consisting of formulae E1, E3 and E6, preferably E1a, E3a and E6a, very preferably E1a2, E1a5, E3a1 and E6a1. The proportion of these compounds in the LC host mixture is preferably from 5 to 60%, very preferably from 10 to 50%.

[0598] 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 LC media according to the invention at the same time as constantly high clearing points and high HR values, and allows the rapid establishment of a particularly low pretilt angle in PSA displays. In particular, the LC 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.

[0599] The LC media and LC host mixtures of the present invention preferably have a nematic phase range of at least 80 K, particularly preferably at least 100 K, and a rotational viscosity 250 mPa.Math.s, preferably 200 mPa.Math.s, at 20 C.

[0600] In the VA-type displays according to the invention, the molecules in the layer of the LC medium in the switched-off state are aligned perpendicular to the electrode surfaces (homeotropically) or have a tilted homeotropic alignment. On application of an electrical voltage to the electrodes, a realignment of the LC molecules takes place with the longitudinal molecular axes parallel to the electrode surfaces.

[0601] LC media according to the invention based on compounds with negative dielectric anisotropy according to the first preferred embodiment, in particular for use in displays of the VA, UB-FFS, PS-VA and PS-UB-FFS type, have a negative dielectric anisotropy , preferably from 0.5 to 10, in particular from 2.5 to 7.5, at 20 C. and 1 kHz.

[0602] The birefringence n in LC media according to the invention for use in displays of the VA, UB-FFS, PS-VA and PS-UB-FFS type is preferably below 0.16, particularly preferably from 0.06 to 0.14, very particularly preferably from 0.07 to 0, 12.

[0603] In the OCB-type displays according to the invention, the molecules in the layer of the LC medium have a bend alignment. On application of an electrical voltage, a realignment of the LC molecules takes place with the longitudinal molecular axes perpendicular to the electrode surfaces.

[0604] LC media according to the invention for use in displays of the OCB, TN, IPS, posi-VA, FFS, PS-OCB, PS-TN, PS-IPS, PS-posi-VA and PS-FFS type are preferably those based on compounds with positive dielectric anisotropy according to the second preferred embodiment, and preferably have a positive dielectric anisotropy &A from +4 to +17 at 20 C. and 1 kHz.

[0605] The birefringence n in LC media according to the invention for use in displays of the OCB and PS-OCB type is preferably from 0.14 to 0.22, particularly preferably from 0.16 to 0.22.

[0606] The birefringence n in LC media according to the invention for use in displays of the TN, posi-VA, IPS, FFS, PS-TN, PS-posi-VA, PS-IPS and PS-FFS-type is preferably from 0.07 to 0.15, particularly preferably from 0.08 to 0.13.

[0607] LC media according to the invention, based on compounds with positive dielectric anisotropy according to the second preferred embodiment, for use in displays of the TN, posi-VA, IPS, FFS, PS-TN, PS-posi-VA, PS-IPS and PS-FFS-type, preferably have a positive dielectric anisotropy from +2 to +30, particularly preferably from +3 to +20, at 20 C. and 1 kHz.

[0608] The LC media according to the invention may also comprise further additives which are known to the person skilled in the art and are described in the literature, such as, for example, polymerisation initiators, inhibitors, stabilisers, surface-active substances or chiral dopants. These may be polymerisable or non-polymerisable. Polymerisable additives are accordingly ascribed to the polymerisable component or component A). Non-polymerisable additives are accordingly ascribed to the non-polymerisable component or component B).

[0609] In a preferred embodiment the LC media contain one or more chiral dopants, preferably in a concentration from 0.01 to 1%, very preferably from 0.05 to 0.5%. The chiral dopants are preferably selected from the group consisting of compounds from Table B below, very preferably from the group consisting of R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, and R- or S-5011.

[0610] In another preferred embodiment the LC media contain a racemate of one or more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph.

[0611] Furthermore, it is possible to add to the LC 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.

[0612] The individual components of the preferred embodiments a)-z) of the LC media according to the invention are either known or methods for the preparation thereof can readily be derived from the prior art by the person skilled in the relevant art, since they are based on standard methods described in the literature. Corresponding compounds of the formula CY are described, for example, in EP-A-0 364 538. Corresponding compounds of the formula ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21 373.

[0613] The LC 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 of the above-mentioned compounds with one or more polymerisable compounds as defined above, and optionally 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. The invention furthermore relates to the process for the preparation of the LC media according to the invention.

[0614] In a preferred embodiment the process of stabilisation of the LC media according to the present invention comprises mixing one or more of the above-mentioned compounds with one or more stabilisers of formula I, and optionally with further liquid crystalline compounds and/or additives. In a particularly preferred embodiment, the desired amount of the components used in lesser amount is dissolved in the components making up the principal constituent.

[0615] When using a compound of formula I as stabilisers, it is further preferred to add it to the LC mixture under inert atmosphere, preferably under nitrogen or argon.

[0616] Advantageously, the mixing process is performed at elevated temperature, preferably above 20 C. and below 120 C., more preferably above 30 C. and below 100 C., most preferably above 40 C. and below 80 C.

[0617] 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. The invention furthermore relates to the process for the preparation of the LC media according to the invention.

[0618] The stabilisation process according to the present invention is particularly useful for LC media exposed to an LCD backlight, typically during the operation of an LC display. Such backlights are preferably cold cathode fluorescent lamps (CCFL) or LED (light-emitting diode) light sources.

[0619] Advantage of these types of light source is the fact that they do not emit UV light or if so, to a negligible extent. Hence, the light stress the LC mixture is exposed to is comparatively small, because of the absence of UV light which could trigger photochemical reactions.

[0620] The stabilisers of formula I are particularly effective when exposed to light with a very small or preferably no portion in the UV region of the spectrum and when used in concentrations of <1000 ppm in the LC mixtures.

[0621] The present invention further relates to LC displays comprising LC mixtures described above and below. The liquid crystal display panel includes first and second substrates, an active region on the first substrate, the active region including a plurality of thin film transistors and pixel electrodes, a sealing region along a periphery of the active region and along a corresponding region of the second substrate, sealant in the sealing region, the sealant attaching the first substrate and the second substrate to one another and maintaining a gap therebetween, and a liquid crystal layer within the gap and on the active region side of the sealant.

[0622] In another aspect of the present invention, a method of manufacturing an LCD panel includes forming a plurality of pixel electrodes in an active region on a first substrate, applying UV-type hardening sealant on a sealing region positioned along a periphery of the active region, attaching the first and second substrates to each other, and irradiating UV-rays to the sealant to harden the sealant.

[0623] In yet another aspect of the present invention, a method of manufacturing an LCD panel includes forming an UV-type hardening sealant in a first sealing region of a first substrate, and dropping liquid crystal on a surface of the first substrate. The first and second substrates are attached to each other at the first and second sealing regions and UV-rays are used to harden the sealant.

[0624] In a preferred embodiment according to the present invention, the active area of the display, i.e. the region of the display that contains switchable LC molecules, is during the LC display manufacturing process not exposed to UV light, at least not exposed to UV light except for the UV portion of ambient light, and preferably shielded from UV light. For example, when hardening a UV-type hardening sealant of the panel, the active region, i.e. the part of the display panel inside the frame used for displaying information, is preferably covered by a shadow mask.

[0625] In another preferred embodiment of the present invention, the LC display manufacturing process does not include a step of polymerising the polymerisable compounds contained in the LC medium, for example by exposing the LC medium to heat or actinic radiation as applied in the process of manufacturing an PSA display.

[0626] It goes without saying to the person skilled in the art that the LC media according to the invention may also comprise compounds in which, for example, H, N, O, Cl, F have been replaced by the corresponding isotopes like deuterium etc.

[0627] The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts with compounds preferably to be employed and the respective concentrations thereof and combinations thereof with one another. In addition, the examples illustrate which properties and property combinations are accessible.

[0628] Preferred mixture components are shown in Tables A1 and A2 below. The compounds shown in Table A1 are especially suitable for use in LC mixtures with positive dielectric anisotropy. The compounds shown in Table A2 are especially suitable for use in LC mixtures with negative dielectric anisotropy.

TABLE-US-00001 TABLE A1 [00154] APU-n-OXF [00155] ACQU-n-F [00156] APUQU-n-F [00157] BCH-nFF [00158] BCH-nFFF [00159] BCH-nFm [00160] CFU-n-F [00161] CBC-nm [00162] CBC-nmF [00163] CCOC-n-m [00164] [00165] C-n-V C-n-XF [00166] [00167] C-n-m CC-n-V [00168] CC-n-Vm [00169] CC-n-kVm [00170] CC-nV-Vm [00171] CCP-nV-m [00172] CCP-Vn-m [00173] CCG-V-F [00174] CCVC-n-V [00175] CCP-n-m [00176] CP-nV-m [00177] CP-Vn-m [00178] CPPC-nV-Vm [00179] CVCP-1V-OT [00180] CLP-n-T [00181] CLP-n-OT [00182] CLP-nV-T [00183] CLP-nV-OT [00184] CLP-Vn-T [00185] CLP-Vn-OT [00186] CLP-nVm-T [00187] CLP-nVm-OT [00188] CLP-nVk-m [00189] CPGP-n-m [00190] CCP-n0CF.sub.3 [00191] CCP-nFFF [00192] CGG-n-F [00193] CGU-n-F [00194] CDU-n-F [00195] DCU-n-F [00196] CCGU-n-F [00197] CPGU-n-F [00198] CCPU-n-F [00199] CPGU-n-OT [00200] CCQU-n-F [00201] CCQG-n-F [00202] CUQU-n-F [00203] CQU-n-F [00204] CCCQU-n-F [00205] CDUQU-n-F [00206] CLUQU-n-F [00207] CPPQU-n-F [00208] CGUQU-n-F [00209] CCZU-n-F [00210] CGZP-n-OT [00211] CPTU-n-F [00212] GPTU-n-F [00213] CPU-n-VT [00214] CPU-n-AT [00215] CPU-n-OXF [00216] CWCG-n-F [00217] CWCU-n-F [00218] CWCQU-n-F [00219] Dec-U-n-F [00220] LPP-n-m [00221] DPGU-n-F [00222] DPGU-n-OT [00223] DGUQU-n-F [00224] DUUQU-n-F [00225] ECCP-nm [00226] ECCP-nOCF.sub.3 [00227] GP-n-Cl [00228] GGP-n-Cl [00229] GGP-n-F [00230] PGIGI-n-F [00231] GPQU-n-F [00232] GUQGU-n-F [00233] PGU-n-OXF [00234] MPP-n-F [00235] MUQU-n-F [00236] NUQU-n-F [00237] PGU-n-F [00238] PPGU-n-F [00239] PQU-n-F [00240] PGUQU-n-F [00241] PGP-n-m [00242] PGP-n-kVm [00243] PP-nV-Vm [00244] PP-n-kVm [00245] PCH-nOm [00246] PCH-nCl [00247] PYP-nF

[0629] In Table A1, m and n are independently of each other an integer from 1 to 12, preferably 1, 2, 3, 4, 5 or 6, k is 0, 1, 2, 3, 4, 5 or 6, and (O)C.sub.mH.sub.2m+1 means C.sub.mH.sub.2m+1 or OC.sub.mH.sub.2m+1.

TABLE-US-00002 TABLE A2 [00248] [00249] AIK-n-F AIY-n-Om [00250] [00251] AY-n-Om B-nO-Om [00252] [00253] B-n-Om B-nO-O5i [00254] CB-n-m [00255] CB-n-Om [00256] PB-n-m [00257] PB-n-Om [00258] BCH-nm [00259] BCH-nmF [00260] BCN-nm [00261] C-1V-V1 [00262] [00263] CY-n-Om CY(F,Cl)-n-Om [00264] CY(Cl,F)-n-Om [00265] CCY-n-Om [00266] CCY(F,Cl)-n-Om [00267] CCY(Cl,F)-n-Om [00268] CCY-n-m [00269] CCY-V-m [00270] CCY-Vn-m [00271] CCY-n-OmV [00272] CBC-nmF [00273] CBC-nm [00274] CCP-V-m [00275] CCP-Vn-m [00276] CCP-nV-m [00277] CCP-n-m [00278] CPYP-n-(O)m [00279] CYYC-n-m [00280] CCYY-n-(O)m [00281] CCY-n-O2V [00282] CCH-nOm [00283] CCC-n-m [00284] CCC-n-V [00285] [00286] CY-n-m CCH-nm [00287] [00288] CC-n-V CC-n-V1 [00289] CC-n-Vm [00290] [00291] CC-V-V CC-V-V1 [00292] CC-2V-V2 [00293] CVC-n-m [00294] CC-n-mV [00295] CCOC-n-m [00296] CP-nOmFF [00297] CH-nm [00298] CEY-n-Om [00299] CEY-V-n [00300] [00301] CVY-V-n CY-V-On [00302] CY-n-O1V [00303] CY-n-OC(CH.sub.3)CH.sub.2 [00304] [00305] CCN-nm CY-n-OV [00306] CCPC-nm [00307] CCY-n-kOm [00308] CPY-n-Om [00309] CPY-n-m [00310] CPY-V-Om [00311] CQY-n-(O)m [00312] CQIY-n-(O)m [00313] CCQY-n-(O)m [00314] CCQIY-n-(O)m [00315] CPQY-n-(O)m [00316] CPQIY-n-(O)m [00317] CPYG-n-(O)m [00318] CCY-V-Om [00319] CCY-V2-(O)m [00320] CCY-1V2-(O)m [00321] CCY-3V-(O)m [00322] CCVC-n-V [00323] CCVC-V-V [00324] CPYG-n-(O)m [00325] CPGP-n-m [00326] CY-nV-(O)m [00327] CENaph-n-Om [00328] COChrom-n-Om [00329] COChrom-n-m [00330] CCOChrom-n-Om [00331] CCOChrom-n-m [00332] CONaph-n-Om [00333] CCONaph-n-Om [00334] CCNaph-n-Om [00335] CNaph-n-Om [00336] CETNaph-n-Om [00337] CTNaph-n-Om [00338] CK-n-F [00339] CLY-n-Om [00340] CLY-n-m [00341] LYLI-n-m [00342] CYLI-n-m [00343] LY-n-(O)m [00344] COYOICC-n-m [00345] COYOIC-n-V [00346] CCOY-V-O2V [00347] CCOY-V-O3V [00348] COY-n-Om [00349] CCOY-n-Om [00350] D-nOmFF [00351] PCH-nm [00352] PCH-nOm [00353] PGIGI-n-F [00354] PGP-n-m [00355] PP-n-m [00356] PP-n-2V1 [00357] PYP-n-mV [00358] PYP-n-m [00359] PGIY-n-Om [00360] PYP-n-Om [00361] PPYY-n-m [00362] PPGU-n-F [00363] YPY-n-m [00364] YPY-n-mV [00365] PY-n-Om [00366] PY-n-m [00367] PY-V2-Om [00368] DFDBC-n(O)-(O)m [00369] [00370] Y-nO-Om Y-nO-OmV [00371] Y-nO-OkVm [00372] [00373] YG-n-Om YG-nO-Om [00374] [00375] YGI-n-Om YGI-nO-Om [00376] [00377] YY-n-Om YY-nO-Om

[0630] In Table A2, m and n are independently of each other an integer from 1 to 12, preferably 1, 2, 3, 4, 5 or 6, k is 0, 1, 2, 3, 4, 5 or 6 and (O)C.sub.mH.sub.2m+1 means C.sub.mH.sub.2m+1 or OC.sub.mH.sub.2m+1.

[0631] In a first preferred embodiment of the present invention, the LC media according to the invention, especially those with positive dielectric anisotropy, comprise one or more compounds selected from the group consisting of compounds from Table A1.

[0632] In a second preferred embodiment of the present invention, the LC media according to the invention, especially those with negative dielectric anisotropy, comprise one or more compounds selected from the group consisting of compounds from Table A2.

TABLE-US-00003 TABLE B [00378] C 15 [00379] CB 15 [00380] CM 21 [00381] R/S-811 [00382] CM 44 [00383] CM 45 [00384] CM 47 [00385] CN [00386] R/S-2011 [00387] R/S-3011 [00388] R/S-4011 [00389] R/S-5011 [00390] R/S-1011

[0633] Table B shows possible chiral dopants which can be added to the LC media according to the invention.

[0634] The LC media preferably comprise 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, of dopants. The LC media preferably comprise one or more dopants selected from the group consisting of compounds from Table B.

TABLE-US-00004 TABLE C [00391] [00392] [00393] [00394] [00395] [00396] [00397] [00398] [00399] [00400] [00401] [00402] [00403] [00404] [00405] [00406] [00407] [00408] [00409] [00410] [00411] [00412] [00413] [00414] [00415] [00416] [00417] [00418] [00419] [00420] [00421] [00422] [00423] [00424] [00425] [00426] [00427] [00428] [00429] [00430] [00431] [00432] [00433] [00434] [00435] [00436] [00437] [00438]

[0635] Table C shows possible stabilisers which can be added to the LC media according to the invention. Therein n denotes an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and terminal methyl groups are not shown.

[0636] The LC media preferably comprise 0 to 10% by weight, in particular 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight, of stabilisers.

[0637] The LC media preferably comprise one or more stabilisers selected from the group consisting of compounds from Table C.

TABLE-US-00005 TABLE D [00439] RM-1 [00440] RM-2 [00441] RM-3 [00442] RM-4 [00443] RM-5 [00444] RM-6 [00445] RM-7 [00446] RM-8 [00447] RM-9 [00448] RM-10 [00449] RM-11 [00450] RM-12 [00451] RM-13 [00452] RM-14 [00453] RM-15 [00454] RM-16 [00455] RM-17 [00456] RM-18 [00457] RM-19 [00458] RM-20 [00459] RM-21 [00460] RM-22 [00461] RM-23 [00462] RM-24 [00463] RM-25 [00464] RM-26 [00465] RM-27 [00466] RM-28 [00467] RM-29 [00468] RM-30 [00469] RM-31 [00470] RM-32 [00471] RM-33 [00472] RM-34 [00473] RM-35 [00474] RM-36 [00475] RM-37 [00476] RM-38 [00477] RM-39 [00478] RM-40 [00479] RM-41 [00480] RM-42 [00481] RM-43 [00482] RM-44 [00483] RM-45 [00484] RM-46 [00485] RM-47 [00486] RM-48 [00487] RM-49 [00488] RM-50 [00489] RM-51 [00490] RM-52 [00491] RM-53 [00492] RM-54 [00493] RM-55 [00494] RM-56 [00495] RM-57 [00496] RM-58 [00497] RM-59 [00498] RM-60 [00499] RM-61 [00500] RM-62 [00501] RM-63 [00502] RM-64 [00503] RM-65 [00504] RM-66 [00505] RM-67 [00506] RM-68 [00507] RM-69 [00508] RM-70 [00509] RM-71 [00510] RM-72 [00511] RM-73 [00512] RM-74 [00513] RM-75 [00514] RM-76 [00515] RM-77 [00516] RM-78 [00517] RM-79 [00518] RM-80 [00519] RM-81 [00520] RM-82 [00521] RM-83 [00522] RM-84 [00523] RM-85 [00524] RM-86 [00525] RM-87 [00526] RM-88 [00527] RM-89 [00528] RM-90 [00529] RM-91 [00530] RM-92 [00531] RM-93 [00532] RM-94 [00533] RM-95 [00534] RM-96 [00535] RM-97 [00536] RM-98 [00537] RM-99 [00538] RM-100 [00539] RM-101 [00540] RM-102 [00541] RM-103 [00542] RM-104 [00543] RM-105 [00544] RM-106 [00545] RM-107 [00546] RM-108 [00547] RM-109 [00548] RM-110 [00549] RM-111 [00550] RM-112 [00551] RM-113 [00552] RM-114 [00553] RM-115 [00554] RM-116 [00555] RM-117 [00556] RM-118 [00557] RM-119 [00558] RM-120 [00559] RM-121 [00560] RM-122 [00561] RM-123 [00562] RM-124 [00563] RM-125 [00564] RM-126 [00565] RM-127 [00566] RM-128 [00567] RM-129 [00568] RM-130 [00569] RM-131

[0638] Table D shows illustrative reactive mesogenic compounds which can be used in the LC media in accordance with the present invention.

[0639] In a preferred embodiment, the mixtures according to the invention comprise one or more polymerisable compounds, preferably selected from the polymerisable compounds of the formulae M-1 to M-131. Of these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-43, RM-47, RM-49, RM-51, RM-59, RM-69, RM-71, RM-83, RM-97, RM-98, RM-104, RM-112, RM-115 and RM-116 are particularly preferred.

[0640] In addition, the following abbreviations and symbols are used:

[0641] V.sub.0 threshold voltage, capacitive [V] at 20 C.,

[0642] n.sub.e extraordinary refractive index at 20 C. and 589 nm,

[0643] n.sub.o ordinary refractive index at 20 C. and 589 nm,

[0644] n optical anisotropy at 20 C. and 589 nm,

[0645] .sub. dielectric permittivity perpendicular to the director at 20 C. and 1 kHz,

[0646] .sub. dielectric permittivity parallel to the director at 20 C. and 1 kHz,

[0647] dielectric anisotropy at 20 C. and 1 kHz,

[0648] cl.p., T(N,I) clearing point [ C.],

[0649] .sub.1 rotational viscosity at 20 C. [mPa.Math.s],

[0650] K.sub.1 elastic constant, splay deformation at 20 C. [pN],

[0651] K.sub.2 elastic constant, twist deformation at 20 C. [pN],

[0652] K.sub.3 elastic constant, bend deformation at 20 C. [pN].

[0653] Unless explicitly noted otherwise, all concentrations in the present application are quoted in percent by weight and relate to the corresponding mixture as a whole, comprising all solid or liquid-crystalline components, without solvents.

[0654] Unless explicitly noted otherwise, all temperature values indicated in the present application, such as, for example, for the melting point T(C,N), the transition from the smectic (S) to the nematic (N) phase T(S,N) and the clearing point T(N,I), are quoted in degrees Celsius ( C.). M.p. denotes melting point, cl.p.=clearing point. Furthermore, C=crystalline state, N=nematic phase, S=smectic phase and I=isotropic phase. The data between these symbols represent the transition temperatures.

[0655] All physical properties are and have been determined in accordance with Merck Liquid Crystals, Physical Properties of Liquid Crystals, Status Nov. 1997, Merck KGaA, Germany, and apply for a temperature of 20 C., and n is determined at 589 nm and &E at 1 kHz, unless explicitly indicated otherwise in each case.

[0656] The term threshold voltage for the present invention relates to the capacitive threshold (V.sub.0), also known as the Freedericks threshold, unless explicitly indicated otherwise. In the examples, the optical threshold may also, as generally usual, be quoted for 10% relative contrast (V.sub.10).

[0657] Unless stated otherwise, the process of polymerising the polymerisable compounds in the PSA displays as described above and below is carried out at a temperature where the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably is carried out at room temperature.

[0658] Unless stated otherwise, methods of preparing test cells and measuring their electrooptical and other properties are carried out by the methods as described hereinafter or in analogy thereto.

[0659] The display used for measurement of the capacitive threshold voltage consists of two plane-parallel glass outer plates at a separation of 25 m, each of which has on the inside an electrode layer and an unrubbed polyimide alignment layer on top, which effect a homeotropic edge alignment of the liquid-crystal molecules.

[0660] The display or test cell used for measurement of the tilt angles consists of two plane-parallel glass outer plates at a separation of 4 m, each of which has on the inside an electrode layer and a polyimide alignment layer on top, where the two polyimide layers are rubbed antiparallel to one another and effect a homeotropic edge alignment of the liquid-crystal molecules.

[0661] The polymerisable compounds are polymerised in the display or test cell by irradiation with UV light of defined intensity for a prespecified time, with a voltage simultaneously being applied to the display (usually 10 V to 30 V alternating current, 1 kHz). In the examples, unless indicated otherwise, a metal halide lamp and an intensity of 100 mW/cm.sup.2 is used for polymerisation.

[0662] The intensity is measured using a standard meter (Hoenle UV-meter high end with UV sensor).

[0663] The tilt angle is determined by crystal rotation experiment (Autronic-Melchers TBA-105). A low value (i.e. a large deviation from the 90 angle) corresponds to a large tilt here.

[0664] Unless stated otherwise, the term tilt angle means the angle between the LC director and the substrate, and LC director means in a layer of LC molecules with uniform orientation the preferred orientation direction of the optical main axis of the LC molecules, which corresponds, in case of calamitic, uniaxially positive birefringent LC molecules, to their molecular long axis.

[0665] The VHR value is measured as follows: 0.3% of a polymerisable monomeric compound is added to the LC host mixture, and the resultant mixture is introduced into VA-VHR test cells which comprise an unrubbed VA-polyimide alignment layer. The LC-layer thickness d is approx. 4 m, unless stated otherwise. The VHR value is determined after 5 min at 100 C. before and after UV exposure at 1 V, 60 Hz, 64 s pulse (measuring instrument: Autronic-Melchers VHRM-105).

Example 1

[0666] Polymerisable monomeric compound 1 is prepared as follows.

##STR00570##

[0667] 1a: To a solution of 1-benzyloxy-4-bromo-benzene (25.0 g, 92.2 mmol) and 4-hydroxyphenylboronic acid (14.7 g, 101.4 mmol) in 310 ml 1,4-dioxane was added sodium carbonate (19.5 g, 184.3 mmol) and 75 ml distilled water. After thoroughly degassing with argon, [1,1-bis(diphenylphosphino)ferrocene]-dichloropalladium(II) (2.02 g, 2.76 mmol) is added. The reaction mixture is heated to reflux and stirred overnight. After cooling to room temperature, the reaction mixture is carefully neutralized with 2 M HCl. The aqueous phase is separated and extracted with ethyl acetate. The organic phase is combined, dried over anhydrous sodium sulfate, and filtrated through silica gel. After removing solvent in vacuo, the obtained crude product is recrystallized from heptane/toluene solvent mixture to provide 1a as light brown crystal (17.8 g).

[0668] 1b: To a solution of 1a (5.7 g, 20.6 mmol) and (3-bromoethyl-oxetan-3-yl)-methanol (5.77 g. 30.9 mmol) in 90 ml DMF is added dry cesium carbonate (10.1 g, 30.9 mmol). The reaction mixture is stirred at 70 C. for 5 hours. After cooling to room temperature, the reaction mixture is added into 100 ml water and neutralized carefully with 2 M HCl. The aqueous phase is extracted with ethylacetate. The organic phase is combined and washed with sat. aq. NaCl solution, dried over sodium sulfate. After removing solvent, the solid residue is recrystallized with toluene/heptane/ethyl acetate solvent mixture to provide 1b as grey crystal (5.9 g).

[0669] 1c: A solution of 1b (5.9 g, 13.3 mmol) in 60 ml tetrahydrofuran is treated with palladium (5%) on activated charcoal (1.0 g) and submitted to hydrogenation for 30 hs. The catalyst is then filtered off, and the remaining solution is concentrated in vacuo. The residue is recrystallized from toluene/heptane solvent mixture to provide 1c as off-white solid (3.5 g).

[0670] 1: Methacrylic acid (2.83 g, 33.3 mmol) and 4-(dimethylamino)pyridine (0.13 g, 1.1 mmol) is added to a suspension of 1c (3.5 g, 11.1 mmol) in 40 ml dichloromethane. The reaction mixture is treated dropwise at 0 C. with a solution of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (5.2 g, 33.3 mmol) in dichloromethane (20 ml) and stirred for 20 h at room temperature. After removing solvent in vacuo, the oily residue is purified by silica gel chromatography with dichcloromethane/ethyl acetate 10:1 as eluent. The obtained product is recrystallized from ethanol to afford white crystals of 1 (2.6 g, mp. 108 C.).

Example 2

[0671] Polymerisable monomeric compound 2 is prepared in analogy to Example 1.

##STR00571##

Example 3

[0672] Polymerisable monomeric compound 3 is prepared as follows.

##STR00572##

[0673] 3a: To a suspension of 2,7-dibromophenanthrene (40.0 g, 0.12 mol) in 500 ml 1,4-dioxane is added the solution of potassium hydroxide (16.5 g, 0.60 mol) in 250 ml distilled water. After thoroughly degassing with argon, bis(dibenzylideneacetone)palladium(O) (1.37 g, 2 mmol) and 2-di-tert-butylphosphino-2,4,6-triisopropylbiphenyl (4.0 g, 9.4 mmol) are added. The reaction mixture is heated to 90 C. and stirred for 3 hours. After cooling to room temperature, 200 ml methyl tert-butyl ether is added. The aqueous phase is separated from the organic phase, and acidified with 2 M aq. HCl solution. The product is then extracted from the aqueous phase with 3200 ml ethyl acetate. After removing solvent, 1a is obtained as yellowish crystal (16.6 g).

[0674] 3b: To a solution of 3a (16.6 g, 79.0 mmol) in 130 ml dichloromethane (DCM) and 150 ml THF is added carefully trimethylamine (12.0 ml, 86.8 mmol) and 4-dimethylamino-pyridine (0.5 g, 4.2 mmol) at 3 C. A solution of chlorotriisopropylsilane (16.9 ml, 79.0 mmol) in 20 ml DCM is then added dropwise at max. 5 C. The reaction mixture is then allowed slowly warmed up to RT and stirred for 6 hours. After distilling off the solvent, 300 ml 1:1 ethyl acetate/THF solvent mixture and 150 ml distilled water is added. The aqueous phase is extracted twice with ethyl acetate. The organic phase is combined, washed with sat. aq. NaCl solution and dried over anhydrous sodium sulfate. After removing solvent, the crude product is purified by column chromatography on silica gel with DCM as elute to provide 3b as light brown solid (13.8 g).

[0675] 3c: To a solution of 3b (13.8 g, 37.8 mmol) in 150 ml DMF is added dry cesium carbonate (4.5 g, 56.8 mmol). The reaction is stirred at RT for 10 min and (3-bromoethyl-oxetan-3-yl)-methanol (10.6 g. 56.8 mmol) is then added. The reaction mixture is heated to 70 C. and stirred for 5 hours. After cooling to room temperature, the reaction mixture is added into 100 ml water and neutralized carefully with 2 M HCl. The aqueous phase is extracted with ethylacetate/THF solvent mixture. The organic phase is combined, washed with sat. aq. NaCl solution and dried over sodium sulfate. After removing solvent, the crude product is purified by column chromatography on silica gel with DCM as elute. A mixture of desired product 3c and di-functionalized side product is obtained (10.5 g), which is used for the next step without further purification.

[0676] 3: The crude product containing 3c (9.5 g) is added in 100 ml DCM. To this suspension is added methacrylic acid (7.9 g, 92.6 mmol) and 4-(dimethylamino)pyridine (0.37 g, 3.1 mmol). The reaction mixture is then treated dropwise at 0 C. with a solution of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (14.37 g, 92.6 mmol) in 20 ml DCM. After slowly warmed up to RT, the reaction mixture is stirred further for 20 hours. After removing solvent in vacuo, the oily residue is purified by silica gel chromatography with heptane/ethyl acetate solvent mixture as eluent. The obtained product is recrystallized from ethanol to afford white crystals of 3 (1.2 g, mp. 120 C.).

Examples 4-7

[0677] The following compounds are prepared in analogy to the methods described in Examples 1-3.

##STR00573## ##STR00574##

Mixture Example 1

[0678] The nematic LC host mixture N1 is formulated as follows.

TABLE-US-00006 CCH-501 9.00% cl.p. 70.0 C. CCH-35 14.00% n 0.0825 PCH-53 8.00% 3.5 CY-3-O4 14.00% .sub.|| 3.5 CY-5-O4 13.00% K.sub.3/K.sub.1 1.00 CCY-2-1 9.00% .sub.1 .sup.141 mPa s CCY-3-1 9.00% V.sub.0 .sup.2.10 V CCY-3-O2 8.00% CCY-5-O2 8.00% CPY-2-O2 8.00%

Mixture Example 2

[0679] The nematic LC host mixture N2 is formulated as follows.

TABLE-US-00007 CY-3-O2 18.00% cl.p. +74.5 C. CPY-2-O2 10.00% n 0.1021 CPY-3-O2 10.00% 3.1 CCY-3-O2 9.00% .sub.|| 3.5 CCY-4-O2 4.00% K.sub.3/K.sub.1 1.16 PYP-23 9.00% .sub.1 86 mPa s CC-3-V 40.00% V.sub.0 2.29 V

Polymerisable Mixture Examples

[0680] Polymerisable mixtures P11-P13 are prepared by adding polymerisable compound 1, 2 or 3, respectively, to nematic LC host mixture N1 at a concentration of 0.3-0.5% by weight.

[0681] Polymerisable mixtures P21-P23 are prepared by adding polymerisable compound 1, 2 or 3, respectively, to nematic LC host mixture N2 at a concentration of 0.3-0.5% by weight.

[0682] For comparison purposes polymerisable mixtures C11, C12 and C13 are prepared by adding polymerisable compound M1, M2 or M3, respectively, of prior art to nematic LC host mixture N1 at a concentration of 0.3% by weight, and polymerisable mixtures C21, C22 and C23 are prepared by adding polymerisable compound M1, M2 or M3, respectively, of prior art to nematic LC host mixture N2 at a concentration of 0.3% by weight.

##STR00575##

[0683] wherein Me is methyl.

[0684] The polymerisable mixture compositions are shown in Table 1 below.

TABLE-US-00008 TABLE 1 Polymerisable mixture composition Mix. No. P11 P12 P13 P21 P22 P23 LC Host N1 N1 N1 N2 N2 N2 Polym. Cpd. 1 2* 3 1 2* 3 Conc. Polym. Cpd. (%) 0.3 0.42 0.3 0.3 0.42 0.3 Mix. No. C11 C12 C13 C21 C22 C23 LC Host N1 N1 N1 N2 N2 N2 Polym. Cpd. M1 M2 M3 M1 M2 M3 Conc. Polym. Cpd. (%) 0.3 0.3 0.3 0.3 0.3 0.3

Use Examples

[0685] Polymerisable mixtures C11-C23 and C21-C23 which contain M1-M3 of prior art, are compared with polymerisable mixtures P11-P13 and P21-P23 which contain one of polymerisable compounds 1-3 according to the invention with an oxetane spacer.

[0686] Voltage Holding Ratio (VHR)

[0687] For measuring the VHR the polymerisable mixtures are inserted into electrooptic test cells. The test cells comprise two AF glass substrates with an ITO electrode layer of approx. 20 nm thickness and a VA-polyimide alignment layer (PI-4) of approx. 100 nm thickness. The LC layer thickness is approx. 4 m.

[0688] The VHR is measured at 100 C. with application of a voltage of 1 V/60 Hz. For the sun-test the test cells are irradiated at 20 C. for 2 h with light having an intensity of 750 W/m.sup.2 using a Xenon lamp (Atlas Suntest CPS+). For the UV test the test cells are irradiated for 10 min with UV light having an intensity of 100 mW/cm.sup.2 (Fe-doped Hg lamp with a 320 nm cut-off filter).

[0689] The results are shown in Table 2.

TABLE-US-00009 TABLE 2 VHR values VHR (%) Mixture no illumination 2 h Suntest C11 98.2 97.6 C12 99.2 98.9 C13 98.9 98.0 P11 98.0 98.5 P12 98.8 98.4 P13 98.6 97.5 VHR (%) Mixture no illumination 2 h Suntest 10 min UV C21 98.3 85.6 74.8 C22 98.8 82.6 77.4 C23 98.1 82.3 74.1 P21 96.2 91.0 87.2 P22 98.1 92.0 91.8 P23 98.3 83.8 76.6

[0690] It can be seen that polymerisable mixtures P11-P13 and P21-P23 containing polymerisable compounds 1-3 according to the present invention show a VHR value after suntest and/or UV test that is comparable or even higher than that of polymerisable mixtures C11-C13 and C21-C23 containing compounds M1-M3 of prior art without an oxetane spacer.

[0691] Residual RM

[0692] The polymerisation speed is measured by determining the residual content of residual, unpolymerised monomer (in % by weight) in the mixture after UV exposure at a given intensity and lamp spectrum.

[0693] For this purpose the polymerisable mixtures are inserted into electrooptic test cells. The test cells comprise two soda-lime glass substrates with an ITO electrode layer of approx. 200 nm thickness and a VA-polyimide alignment layer (JALS-2096-R1) of approx. 30 nm thickness. The LC layer thickness is approx. 25 m.

[0694] The test cells are irradiated with UV light having an intensity of 100 mW/cm.sup.2 (metal halide lamp with a 320 nm cut-off filter) for the time indicated, causing polymerisation of the RM, while the temperature at the bottom side of the test cell is kept at 20 C.

[0695] The mixture is then rinsed out of the test cell using MEK (methyl ethyl ketone) and the residual amount of unreacted monomer is measured by HPLC. The results are shown in Table 3.

TABLE-US-00010 TABLE 3 Residual monomer content Residual RM (%) after Exposure Time (min) Mixture 0 2 4 6 C11 0.300 0.264 0.203 0.173 C12 0.300 0.255 0.191 0.140 C13 0.300 0.105 0.033 0.019 P11 0.300 0.267 0.210 0.164 P13 0.300 0.068 0 Residual RM (%) after Exposure Time (min) Mixture 0 2 6 C21 0.300 0.185 0.067 C22 0.300 0.178 0.016 C23 0.300 0.082 0 P21 0.300 0.206 0.085 P23 0.300 0.079 0

[0696] Tilt Angle Generation

[0697] For measuring the tilt angle generation the polymerisable mixtures are inserted into electrooptic test cells. The test cells comprise two soda-lime glass substrates with an ITO electrode layer of approx. 200 nm thickness and a VA-polyimide alignment layer (JALS-2096-R1) of approx. 30 nm thickness which is rubbed antiparallel. The LC-layer thickness d is approx. 4 m.

[0698] The test cells are irradiated with UV light having an intensity of 100 mW/cm.sup.2 (metal halide lamp with a 320 nm cut-off filter) for the time indicated, with application of a voltage of 24 V.sub.RMS (alternating current), causing polymerisation of the RM.

[0699] The tilt angle is determined before and after UV irradiation by a crystal rotation experiment (Autronic-Melchers TBA-105). The results are shown in Table 3.

TABLE-US-00011 TABLE 3 Tilt angles Tilt Angle () after Exposure Time (sec) Mixture 0 30 60 120 240 360 C11 89.6 89.0 88.2 84.9 79.8 77.5 C12 88.6 89.0 87.5 84.1 78.7 75.8 C13 89.6 88.8 86.3 76.5 69.2 69.3 P11 89.2 88.5 87.0 83.3 79.4 75.9 P12 88.3 87.9 85.5 80.5 68.3 64.6 P13 89.5 86.6 80.8 75.4 72.2 71.1 Tilt Angle () after Exposure Time (sec) Mixture 0 120 360 C21 88.8 77.2 70.3 C22 88.5 78.5 74.8 C23 87.6 74.5 71.3 P21 89.2 80.4 76.9 P22 89.7 73.3 67.6 P23 89.9 79.6 77.0

[0700] The use examples demonstrate that the polymerisable compounds and polymerisable mixtures according to the present invention show in particular a quick polymerisation with low amount of residual monomer, while maintaining sufficient pretilt angle generation and sufficient VHR values after suntest or UV exposure for display applications.