Liquid crystal display

Abstract

The present invention relates to a liquid crystal (LC) display of the FFS type comprising a liquid crystal medium with negative dielectric anisotropy and a di- or multireactive polymerizable compound, and an alignment layer inducing planar alignment in the LC medium.

Claims

1. A liquid crystal display of Fringe Field Switching mode, comprising: two substrates, two electrodes provided on one of the substrates, and a layer of a liquid crystal medium located between the substrates, said medium having negative dielectric anisotropy and comprising liquid crystal molecules and one or more polymerizable compounds having two or more polymerizable groups, said display further comprising an alignment layer provided on at least one of the substrates, wherein said alignment layer is in contact with the liquid crystal medium and induces planar alignment of the liquid crystal molecules of the liquid crystal medium, and wherein said liquid crystal medium comprises (a) a polymerizable component A) consisting of one or more polymerizable compounds, and (b) a liquid crystalline component B) consisting of non-polymerizable compounds and containing one or more mesogenic or liquid crystalline compounds comprising an alkenyl group, wherein component (B) contains one or more compounds of formula ZK1 ##STR00278## in which alkyl and alkyl* each, independently of one another, each denote a straight-chain alkyl radical having 1-6 C atoms, one or more compounds of formula T: ##STR00279## in which 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 each be replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another, ##STR00280## each, independently of one another, denote ##STR00281## L.sup.5 denotes F or Cl, and L.sup.6 denotes F, Cl, OCF.sub.3, CF.sub.3, CH.sub.3, CH.sub.2F or CHF.sub.2, and one or more compounds selected from formula AN1 and PY1-PY8: ##STR00282## wherein 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 2-7 C atoms, wherein the concentration of alkenyl compounds in component B) is 20-60 wt. %, wherein the concentration of compounds of formulae PY1-PY8 is 2-20 wt. % based on the total weight of liquid crystal medium, and wherein the concentration of polymerizable compounds in the liquid crystal medium is >0 to <5 wt. %.

2. The liquid crystal display of claim 1, wherein one of the electrodes has a comb-shaped structure and the other electrode is unstructured.

3. The liquid crystal display of claim 1, wherein the alignment layer comprises a polyimide.

4. The liquid crystal display of claim 1, wherein the polymerizable compounds are polymerized in the liquid crystal display.

5. The liquid crystal display of claim 1, wherein the liquid crystal medium further comprises one or more compounds selected from formula AY which differ from compounds of formulae PY1-PY8: ##STR00283## in which the individual radicals, on each occurrence identically or differently, each, independently of one another, have the following meaning: ##STR00284## R.sup.A1 is alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, R.sup.A1 can also be alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may each be replaced by —O—, —CH═CH—, —CO—, —OCO— or —COO— in such a way that O atoms are not linked directly to one another, R.sup.A2 alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may each be replaced by —O—, —CH═CH—, —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—, —CH═CH—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2O—, —OCH.sub.2—, —CO—O—, —O—CO—, —C.sub.2F.sub.4—, —CF═CF—, —CH═CH—CH.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, and z 0 or 1.

6. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from the following formulae: ##STR00285## in which alkyl denotes 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.

7. The liquid crystal display of claim 6, wherein the liquid crystal medium comprises one or more compounds selected from the following formulae: ##STR00286## 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.

8. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from the following formulae: ##STR00287##

9. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from the following formulae: ##STR00288## in which the individual radicals have the following meanings: a denotes 1 or 2, b denotes 0 or 1, ##STR00289## 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 each be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that O atoms are not linked directly to one another, Z.sup.x denotes —CH═CH—, —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, and 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.

10. The liquid crystal display of claim 1, wherein the liquid crystal medium further comprises one or more compounds selected from the following formula: ##STR00290## in which the individual radicals have the following meanings: ##STR00291## 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 each be replaced by —O—, —CH═CH—, —CO—, —O—CO— or —CO—O— in such a way that O atoms are not linked directly to one another, and Z.sup.y denotes —CH.sub.2CH.sub.2—, —CH═CH—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2O—, —OCH.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —CF═CF— or a single bond.

11. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more polymerizable compounds selected from the following formula
R.sup.a-A.sup.1-(Z.sup.1-A.sup.2).sub.m1-R.sup.b  I* in which the individual radicals have the following meanings: R.sup.a and R.sup.b each, independently of one another, denote P, P-Sp-, H, halogen, SF.sub.5, NO.sub.2, a carbyl group or a hydrocarbyl group, P on each occurrence, identically or differently, denotes a polymerizable group, Sp on each occurrence, identically or differently, denotes a spacer group or a single bond, A.sup.1 and A.sup.2 each, independently of one another, denote an aromatic, heteroaromatic, alicyclic or heterocyclic group, which may also contain fused rings, and which is optionally mono- or polysubstituted by L, Z.sup.1 on each occurrence, identically or differently, denotes —O—, —S—, —CO—, —CO—O—, —OCO—, —O—CO—O—, —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—, —CH═CH—, —CF═CF—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH—, CR.sup.0R.sup.00 or a single bond, L denotes P, P-Sp-, H, OH, CH.sub.2OH, halogen, SF.sub.5, NO.sub.2, a carbyl group or hydrocarbyl group, R.sup.0 and R.sup.00 each, independently of one another, denote H or alkyl having 1 to 12 C atoms, m1 denotes 0, 1, 2, 3 or 4, and n1 denotes 1, 2, 3 or 4, wherein at least one of the radicals R.sup.a, R.sup.b and L denotes or contains a group P or P-Sp-.

12. The liquid crystal display of claim 11, wherein in the polymerizable compounds of formula I* A.sup.1 and A.sup.2 each, independently of one another, denote 1,4-phenylene, 1,3-phenylene, 1,2-phenylene, naphthalene-1,4-diyl, naphthalene2,6-diyl, phenanthrene-2,7-diyl, anthracene-2,7-diyl, or fluorene-2,7-diyl, in which, in addition, one or more CH groups in these groups may each be replaced by N, cyclohexane-1,4-diyl, in which, in addition, one or more non-adjacent CH.sub.2 groups may each be replaced by O or S, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl, octahydro-4,7-methanoindane-2,5-diyl, 9,10-dihydro-phenanthrene-2,7-diyl, 2H-chromen-2-one-3,6-diyl, 2H-chromen-2-one-3,8-diyl, or 2H-chromen-2-one-3,7-diyl, where all these groups may be unsubstituted or mono- or polysubstituted by L, L denotes P, P-Sp-, OH, CH.sub.2OH, F, Cl, Br, I, —CN, —NO.sub.2, —NCO, —NCS, —OCN, —SCN, —C(═O)N(R.sup.x).sub.2, —C(═O)Y.sup.1, —C(═O)R.sup.x, —N(R.sup.x).sub.2, optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms, straight-chain or branched alkyl or alkoxy having 1 to 25 C atoms, or straight-chain or branched alkenyl, alkinyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 2 to 25 C atoms, wherein in all of these groups, in addition, one or more H atoms may each be replaced by F, Cl or P-Sp-, Y.sup.1 denotes halogen, R.sup.x denotes P, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH.sub.2 groups may each be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— 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 each be replaced by F, Cl or P-Sp-, an optionally substituted aryl or aryloxy group having 6 to 40 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 40 C atoms, where at least one of the radicals R.sup.a, R.sup.b and L denotes P or P-Sp-.

13. The liquid crystal display of claim 1, wherein the polymerizable compounds are selected from the following formulae ##STR00292## ##STR00293## ##STR00294## ##STR00295## in which the individual radicals have the following meanings: P.sup.1, P.sup.2 and P.sup.3 each, independently of one another, denote a polymerizable group, Sp.sup.1, Sp.sup.2 and Sp.sup.3 each, independently of one another, denote a single bond or a spacer group of the formula Sp′-X′, where, in addition, one or more of the radicals P.sup.1-Sp.sup.1-, P.sup.1-Sp.sup.2- and P.sup.3-Sp.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.2-Sp.sup.2 and P.sup.3-Sp.sup.3- present is different from R.sup.aa, Sp′ denotes straight-chain or branched alkylene having 1 to 20 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I, CN or P, 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.00R.sup.000)—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —S—CO—, —CO—S—, —N(R.sup.00)—CO—O—, —O—CO—N(R.sup.00)—, —N(R.sup.00)—CO—N(R.sup.00)—, —CH═CH— or —C≡C— in such a way that O and/or S atoms are not linked directly to one another, X′ denotes —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —CO—N(R.sup.00)—, —N(R.sup.00)—CO—, —N(R.sup.00)—CO—N(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—, —CH═N—, —N═CH—, —N═N—, —CH═CR.sup.0—, —CY.sup.2═CY.sup.3—, —C≡C—, —CH═CH—CO—O—, —O—CO—CH═CH— or a single bond, wherein X′ denotes a single bond if it is adjacent to an ester group, 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)—, —C≡C—, —N(R.sup.0)—, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— 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, 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, X.sup.1, X.sup.2 and X.sup.3 each, independently of one another, denote —CO—O—, —O—CO— or a single bond, Z.sup.1 denotes —O—, —CO—, —C(R.sup.yR.sup.z)— or —CF.sub.2CF.sub.2—, R.sup.y and R.sup.z each, independently of one another, denote H, F, CH.sub.3 or CF.sub.3, Z.sup.2 and Z.sup.3 each, independently of one another, denote —CO—O—, —O—CO—, —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, L on each occurrence, identically or differently, denotes F, Cl, CN or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, L′ and L″ each, independently of one another, denote H, F or Cl, r denotes 0, 1, 2, 3 or 4, s denotes 0, 1, 2 or 3, t denotes 0, 1 or 2, and x denotes 0 or 1.

14. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more polymerizable compounds selected from the following formulae: ##STR00296## ##STR00297## ##STR00298## ##STR00299## ##STR00300## ##STR00301##

15. The liquid crystal display of claim 1, wherein the liquid crystal medium contains at least one chiral dopant selected from the following compounds: ##STR00302##

16. The liquid crystal display of claim 1, wherein the liquid crystal medium contains at least one stabilizer selected from the following formulae: ##STR00303## ##STR00304## ##STR00305## ##STR00306## wherein n denotes an integer from 1 to 12.

17. A process for the production of a liquid crystal display according to claim 1, comprising: filling said liquid crystal medium between the substrates of the display, and polymerizing the polymerizable compounds.

18. The liquid crystal display according to claim 5, wherein Z.sup.x is a single bond, and L.sup.1-4 are each, independently of one another, H, F or Cl.

19. The liquid crystal display of claim 6, wherein alkenyl and alkenyl* each, independently of one another, denote CH.sub.2═CH—, CH.sub.2═CHCH.sub.2CH.sub.2—, CH.sub.3—CH═CH—, CH.sub.3—CH.sub.2—CH═CH—, CH.sub.3—(CH.sub.2).sub.2—CH═CH—, CH.sub.3—(CH.sub.2).sub.3—CH═CH— or CH.sub.3—CH═CH—(CH.sub.2).sub.2—.

20. The liquid crystal display according to claim 9, wherein Z.sup.x is a single bond.

21. The liquid crystal display according to claim 11, wherein P on each occurrence, identically or differently, denotes an acrylate or methacrylate group.

22. The liquid crystal display according to claim 13, wherein P.sup.1, P.sup.2 and P.sup.3 each, independently of one another, denote an acrylate or methacrylate groups, and Sp.sup.1, Sp.sup.2 and Sp.sup.3 each, independently of one another, denote a single bond or —(CH.sub.2).sub.p1—, —(CH.sub.2).sub.p1—O—, —(CH.sub.2).sub.p1—CO—O—, —(CH.sub.2).sub.p1—O—CO— or —(CH.sub.2).sub.p1—O—CO—O—, 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.1-Sp.sup.2- and P.sup.3-Sp.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.2-Sp.sup.2 and P.sup.3-Sp.sup.3- present is different from R.sup.aa.

23. The liquid crystal display according to claim 1, wherein the liquid crystal medium comprises a compound of the following formula: ##STR00307## wherein the propyl is a straight-chain groups.

24. The liquid crystal display according to claim 1, wherein the liquid crystal medium comprises one or more compounds of formula T2: ##STR00308## wherein (O) denotes an oxygen atom or a single bond, and m denotes an integer from 1 to 6.

25. The liquid crystal display according to claim 1, wherein the liquid crystal medium comprises a compound of the following formula: ##STR00309##

26. The liquid crystal display according to claim 1, wherein the liquid crystal medium comprises one or more compounds of formulas CY30 and/or CY32: ##STR00310## wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and (O) denotes an oxygen atom or a single bond.

27. The liquid crystal display according to claim 1, wherein said medium contains one or more polymerizable compounds selected from formulae M29 and M30 ##STR00311## in which the individual radicals have the following meanings: P.sup.1, P.sup.2 and P.sup.3 each, independently of one another, denote a polymerizable group, Sp.sup.1, Sp.sup.2 and Sp.sup.3 each, independently of one another, denote a single bond or a spacer group of the formula Sp′-X′, where, in addition, one or more of the radicals P.sup.1-Sp.sup.1-, P.sup.1-Sp.sup.2- and P.sup.3-Sp.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.2-Sp.sup.2 and P.sup.3-Sp.sup.3- present is different from R.sup.aa, Sp′ denotes straight-chain or branched alkylene having 1 to 20 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I, CN or P, 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.00R.sup.000)—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —S—CO—, —CO—S—, —N(R.sup.00)—CO—O—, —O—CO—N(R.sup.00)—, —N(R.sup.00)—CO—N(R.sup.00)—, —CH═CH— or —C≡C— in such a way that O and/or S atoms are not linked directly to one another, X′ denotes —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O—, —CO—N(R.sup.00)—, —N(R.sup.00)—CO—, —N(R.sup.00)—CO—N(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—, —CH═N—, —N═CH—, —N═N—, —CH═CR.sup.0—, —CY.sup.2═CY.sup.3—, —C≡C—, —CH═CH—CO—O—, —O—CO—CH═CH— or a single bond, wherein X′ denotes a single bond if it is adjacent to an ester group, 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)—, —C≡C—, —N(R.sup.0)—, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— 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-, 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, X.sup.1, X.sup.2 and X.sup.3 each, independently of one another, denote —CO—O—, —O—CO— or a single bond, Z.sup.1 denotes —O—, —CO—, —C(R.sup.yR.sup.z)— or —CF.sub.2CF.sub.2—, R.sup.y and R.sup.z each, independently of one another, denote H, F, CH.sub.3 or CF.sub.3, Z.sup.2 and Z.sup.3 each, independently of one another, denote —CO—O—, —O—CO—, —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, L on each occurrence, identically or differently, denotes F, Cl, CN or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, L′ and L″ each, independently of one another, denote H, F or Cl, r denotes 0, 1, 2, 3 or 4, s denotes 0, 1, 2 or 3, t denotes 0, 1 or 2, and x denotes 0 or 1.

28. The liquid crystal display according to claim 27, wherein said medium contains one or more polymerizable compounds selected from formulae M70 and M71. ##STR00312##

29. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from the following formula: ##STR00313## in which m denotes 1, 2, 3, 4, 5 or 6, and R.sup.b1 denotes H, CH.sub.3 or C.sub.2H.sub.5.

30. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from the following formula: ##STR00314##

31. The liquid crystal display of claim 1, wherein the liquid crystal medium comprises one or more compounds selected from formula PY2.

32. The liquid crystal display of claim 31, wherein the liquid crystal medium as a whole contains 1 to 20% of compounds of formula PY2.

33. The liquid crystal display of claim 1, wherein said medium comprises one or more polymerizable compounds having three or more polymerizable groups.

Description

A) LC HOST MIXTURES

Example 1

(1) The nematic LC host mixture N1 is formulated as follows.

(2) TABLE-US-00005 CY-3-O2 13.00% cl. p. +80.0° C. CCY-3-O2 6.00% Δn 0.1025 CCY-4-O2 7.00% Δε −3.8 CPY-2-O2 9.00% ε.sub.∥ 3.8 CPY-3-O2 9.00% K.sub.3/K.sub.1 1.15 PYP-2-3 0.50% γ.sub.1 112 mPa s PY-3-O2 10.00% CCY-3-O1 10.00% CC-3-V1 10.50% CC-3-V 25.00%

Example 2

(3) The nematic LC host mixture N2 is formulated as follows.

(4) TABLE-US-00006 BCH-32 4.50% cl. p. 85.5° C. CC-3-V 23.50% Δn 0.1109 CCH-3O1 4.00% Δε −4.3 CCY-3-O2 4.00% ε.sub.∥ 3.7 CCY-3-O3 7.00% K.sub.3/K.sub.1 1.13 CCY-4-O2 8.00% γ.sub.1 140 mPa s CLY-3-O2 8.00% CPY-2-O2 7.00% CPY-3-O2 11.00% CY-3-O2 10.00% CY-3-O4 1.00% PY-3-O2 11.00% PY-4-O2 1.0%

Example 3

(5) Polymerizable mixtures are prepared by adding in each case one of the monomers of Table 1 to the LC host mixtures N1 and N2, respectively, at a concentration of 0.3% by weight.

(6) TABLE-US-00007 TABLE 1 RM1 RM2 RM3 RM4

Example 4

(7) Each of the polymerizable mixtures was inserted into a FFS e/o test cell (polyimide alignment layer which was rubbed or treated by photoalignment, LC-layer thickness d 3 to 4 μm). The test cells were irradiated with UV light having an intensity of 100 mW/cm.sup.2 for the time indicated with application of a voltage of 24 V.sub.rms (alternating current), causing polymerization of the polymerizable monomeric compound.

(8) The VHR values of the polymerizable mixtures before and after UV exposure were measured as described above. For comparison purposes similar measurements were carried out for the pure host mixtures N1 and N2 without a polymerizable compound as reference. The results are shown in Tables 2 and 3, wherein “suntest” means an irradiation step with lower UV intensity but longer exposure time than the UV step.

(9) TABLE-US-00008 TABLE 2 N1 N1 + RM1 N1 + RM2 N1 + RM4 VHR/% initial 60.23 50.30 56.14 57.23 after 10 min UV 64.38 75.30 77.65 after 30 min 49.81 66.72 74.71 73.02 sunstest

(10) TABLE-US-00009 TABLE 3 N2 N2 + RM1 N2 + RM3 N2 + RM4 VHR/% initial 53.32 51.84 51.94 53.09 after 10 min UV 61.68 73.08 70.32 after 30 min 49.13 63.51 72.01 63.29 sunstest

(11) From Table 2 and 3 it can be seen that, in the LC media comprising a polymerizable compound, after polymerization the VHR value increased after 10 min UV compared to the initial value, and also compared to the VHR values of the reference LC media not containing a polymerizable compound.

(12) Also after a typical light load of 30 min suntest the VHR value is stable in the LC media with the polymerized compound, whereas it decreases in the reference LC media. This shows that a significant improvement of the reliability behavior of an FFS LC medium according to the present invention could be achieved, compared to a standard FFS LC medium without a polymerizable compound.

(13) Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.

(14) The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

(15) From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

(16) The entire disclosures of all applications, patents and publications, cited herein and of corresponding European patent application no. 14000204.9, filed Jan. 21, 2014, are incorporated by reference herein.