REFLECTIVE LIQUID CRYSTAL PANEL
20250179365 ยท 2025-06-05
Assignee
Inventors
Cpc classification
G02F1/13712
PHYSICS
C09K19/3003
CHEMISTRY; METALLURGY
C09K19/54
CHEMISTRY; METALLURGY
G02F1/13439
PHYSICS
C09K2019/3408
CHEMISTRY; METALLURGY
International classification
G02F1/137
PHYSICS
C09K19/30
CHEMISTRY; METALLURGY
Abstract
LCoS panels using liquid crystal (LC) media having negative dielectric anisotropy and to the LC media comprised therein. The liquid crystal medium (LC medium) is a negative dielectric anisotropy liquid crystal material having high optical anisotropy. It is particularly useful in electro-optical displays including projection systems based on vertical alignment (VA) nematic panels.
Claims
1. A Liquid Crystal on Silicon (LCoS) panel comprising a semiconductor substrate having a plurality of reflective electrodes, a transparent substrate comprising a transparent electrode assembled with the semiconductor substrate, and a liquid crystal layer arranged between the semiconductor substrate and the transparent substrate, wherein the liquid crystal layer comprises a liquid crystal medium comprising a) one or more compounds of formula IV ##STR00338## in which R.sup.41 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, and R.sup.42 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, an unsubstituted alkenyl radical having 2 to 7 C atoms, wherein one or more compounds of formula IV are selected from formula IV-2, ##STR00339## wherein alkyl denotes alkyl having 1 to 7 C atoms, and alkoxy denotes alkoxy having 1 to 5 C atoms.
2. The LCoS panel according to claim 1 comprising one or more inorganic alignment layers.
3. The LCoS panel according to claim 1 wherein the liquid crystal medium has a clearing point of 90 C. or more.
4. The LCoS panel according to claim 1, wherein the liquid crystal medium is vertically aligned with regard to the substrates.
5. A liquid crystal medium comprising a) one or more compounds of formula IV ##STR00340## in which R.sup.41 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, and R.sup.42 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, wherein one or more compounds of formula IV are selected from formula IV-2, ##STR00341## wherein alkyl denotes alkyl having 1 to 7 C atoms, alkoxy denotes alkoxy having 1 to 5 C atoms, b) one or more compounds of formula I ##STR00342## in which R.sup.11 denotes alkyl having 1 to 7 C atoms, alkoxy having 1 to 7 C atoms, or alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another by ##STR00343## R.sup.12 denotes alkyl having 1 to 7 C atoms, alkoxy having 1 to 7 C atoms, or alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms, and c) 0.1% to 0.9% of one or more compounds of formula ST-1 ##STR00344## wherein R.sup.ST denotes H, an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another by CC, CF.sub.2O, OCF.sub.2, CHCH, ##STR00345## O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, ##STR00346## on each occurrence, identically or differently, denotes ##STR00347## Z.sup.ST each, independently of one another, denote COO, OCO, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, CH.sub.2, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCH, CH.sub.2O, C.sub.2F.sub.4, CH.sub.2CF.sub.2, CF.sub.2CH.sub.2, CFCF, CHCF, CFCH, CHCH, CC or a single bond, and p denotes 0, 1 or 2.
6. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds selected from the group of the formulae in d) and e): d) formulae IIA, IIB, IIC, IID and IIE, ##STR00348## in which R.sup.2A, R.sup.2B, R.sup.2C, R.sup.2D, R.sup.2E1 and R.sup.2E2 each, independently of one another, denote H, an alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S, ##STR00349## CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another; L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, CF.sub.3 or CHF.sub.2; Y denotes H, F, Cl, CF.sub.3, CHF.sub.2 or CH.sub.3; Z.sup.2, Z.sup.2B and Z.sup.2D each, independently of one another, denote a single bond, CH.sub.2CH.sub.2, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, COO, OCO; p denotes 0, 1 or 2, q denotes 0 or 1, and v denotes 1, 2, 3, 4, 5 or 6; e) formula III ##STR00350## in which R.sup.31 and R.sup.32, each, independently of one another, denote H, an alkyl or alkoxy radical having 1 to 7 C atoms, where one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by ##STR00351## CC, CF.sub.2O, OCF.sub.2, CHCH, by O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by halogen, A.sup.3 on each occurrence, independently of one another, denotes a 1,4-phenylene radical, in which one or two CH groups may be replaced by N, or a 1,4-cyclohexylene or 1,4-cyclohexenylene radical, in which one or two non-adjacent CH.sub.2 groups may be replaced by O or S, where the radicals may be mono- or polysubstituted by halogen atoms, Z.sup.3 on each occurrence independently of one another denotes CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, CH.sub.2, CH.sub.2CH.sub.2, CHCH, CC or a single bond, L.sup.31 and L.sup.32, each, independently of one another, denote F, Cl, CF.sub.3 or CHF.sub.2, W denotes O or S, and n denotes 0, 1 or 2.
7. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of formula IIE ##STR00352## in which R.sup.2E1 independently denotes H, an alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S, ##STR00353## CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another; R.sup.2E2 independently denotes an alkoxy or alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by ##STR00354## Y denotes H, F, Cl, CF.sub.3, CHF.sub.2 or CH.sub.3; L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, CF.sub.3 or CHF.sub.2.
8. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of the formula H ##STR00355## in which A denotes an aliphatic, aromatic or heteroaromatic hydrocarbon group with q valencies and having 1 to 40 C atoms; or a bond for q=2; Sp denotes a spacer group or a bond; HA denotes ##STR00356## R.sup.S denotes H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; Z.sup.S denotes O, C(O)O, (CH.sub.2).sub.z or (CH.sub.2).sub.zO, or a single bond; R.sup.H denotes H, O.Math., CH.sub.3, OH or OR.sup.S; R.sup.S1, R.sup.S2, R.sup.S3 and R.sup.S4, identically or differently, denote alkyl having 1 to 6 C atoms; G denotes H or R.sup.S or a group Z.sup.S-HA; z is an integer from 1 to 6; and q is 1, 2, 3 or 4.
9. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of formula H-A ##STR00357## wherein A.sup.a denotes an alkylene group with 1 to 12 carbon atoms, wherein one or two CH.sub.2 groups may be replaced by 1,4-cyclohexylene, and R.sup.H denotes H or O.
10. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of formula IV-1 and IV-3, ##STR00358## in which alkyl and alkyl, independently of one another, denote alkyl having 1 to 7 C atoms, alkenyl denotes an alkenyl radical having 2 to 5 C atoms.
11. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of formula P-1, ##STR00359## in which R.sup.P denotes a straight-chain alkyl or alkoxy radical having 1-6 C atoms or an alkenyl radical having 2-6 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S, ##STR00360## CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another; X.sup.P straight-chain alkyl having 1-6 C atoms, F, Cl, CF.sub.3, OCF.sub.2H, OCF.sub.3, OCHFCF.sub.3, OCF.sub.2CHFCF.sub.3, OCHCF.sub.2, L.sup.P1, L.sup.P2 and L.sup.P3 each independently of one another denote H or F, and L.sup.P4 denotes H or CH.sub.3.
12. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of the formula PIII-1, ##STR00361## in which R.sup.3 denote a straight-chain or branched alkyl radical that is unsubstituted or halogenated and has 1 to 15 C atoms, where one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by ##STR00362## CC, CF.sub.2O, CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another, L.sup.31 and L.sup.32 identically or differently, denote H or F, Y.sup.3 identically or differently, denote H or CH.sub.3, X.sup.3 identically or differently, denote halogen, CN, halogenated alkyl or alkoxy with 1 to 3 C-atoms or halogenated alkenyl or alkenyloxy with 2 or 3 C-atoms, and n independently is 0 or 1.
13. The liquid crystal medium according to claim 5, wherein the medium comprises one or more compounds of formula VI ##STR00363## in which R.sup.6 and R.sup.62 each, independently of one another, denote H, an alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S, ##STR00364## CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another and R.sup.62 alternatively denotes F, Cl, CF.sub.3 or OCF.sub.3 and L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 independently denote H or F, where at least one of L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 denotes F, and wherein the compounds of formula IIC and IIE are excluded.
14. An LCoS panel comprising the liquid crystal medium according to claim 5.
15. A projection system comprising the LCoS panel according to claim 14, a light source, and a light directing element.
16. An LCoS panel, a projection system, a near-eye display or a beam-steering application comprising the liquid crystal medium according to claim 5.
Description
DETAILED DESCRIPTION OF THE INVENTION
[0074] In the following the essential and optional components of the LC media are disclosed in more detail, which relate to preferred embodiments of the media and the LC displays containing them.
[0075] Preferred compounds of the formulae IIA, IIB, IIC, IID and IIE are indicated below:
##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020##
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
in which the parameter 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, preferably an oxygen atom. Alkenyl preferably denotes any of the groups 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.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.
[0076] Very preferred compounds of the formula IID are selected from the following sub-formulae:
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
wherein v denotes 1, 2, 3, 4, 5 or 6.
[0077] In a preferred embodiment, the medium comprises one or more compounds of formula IID-12a
##STR00031##
wherein the groups are defined as for formula IID above, preferably R.sup.2 denotes
##STR00032##
in which r is 0, 1, 2, 3, 4, 5 or 6, s is 1,2 or 3.
[0078] In a preferred embodiment, the medium comprises one or more compounds of formula IIE as follows:
##STR00033##
in which the occurring groups and parameters have the meanings given above under formula IIE.
[0079] More preferred media according to the invention comprise one or more compounds of the formulae IIA-2, IIA-8, IIA-10, IIA-16, IIA-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1, IID-4 and IID-10.
[0080] Very preferred media according to the invention comprise one or more compounds of formula IIB-2
##STR00034##
in which 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, in particular the compounds IIB-2-1 and IIB-2-2:
##STR00035##
[0081] Preferred media according to the invention comprise at least one compound of the formula IIC-1,
##STR00036##
in which alkyl and alkyl* have the meanings indicated above, preferably in amounts of 0.5% to 5% by weight, in particular 1% to 3% by weight.
[0082] In particular, the medium comprises one or more compounds of the formula IIA-2 selected from the following sub-formulae:
##STR00037##
[0083] Alternatively, preferably in addition to the compounds of the formulae IIA-2-1 to IIA-2-5, the medium comprises one or more compounds of the formulae IIA-2a-1 to IIA-2a-5:
##STR00038##
[0084] In particular, the medium comprises one or more compounds of the formula IIA-10 or IIA-52 selected from the following sub-formulae:
##STR00039##
[0085] Alternatively, preferably in addition to the compounds of the formulae IIA-10-1 to IIA-10-5, the medium comprises one or more compounds of the formulae IIA-10a-1 to IIA-10a-5:
##STR00040##
[0086] In particular, the medium comprises one or more compounds of the formula IIB-10 selected from the following sub-formulae:
##STR00041##
[0087] Alternatively, preferably in addition to the compounds of the formulae IIB-10-1 to IIB-10-5, the medium comprises one or more compounds of the formulae IIB-10a-1 to IIB-10a-5:
##STR00042##
[0088] Very preferably, the medium according to the invention comprises one or more compounds of formula IIE, in particular the compounds of the formula IIE-1-1 to IIE-1-8, and most preferably one or more of the compound of formulae IIE-1-1-1 to IIE-1-1-4:
##STR00043##
[0089] The compounds of formula III are preferably selected from the compounds of the formula III-1, III-2 and/or III-4
##STR00044##
in which the occurring groups have the same meanings as given under formula III above and preferably [0090] R.sup.31 and R.sup.32 each, independently of one another, an alkyl or alkoxy radical having 1 to 15 C atoms or an alkenyl radical having 2 to 15 C atoms, more preferably one or both of them denote an alkoxy radical having 1 to 7 C atoms, and [0091] L.sup.31 and L.sup.32 preferably denote F.
[0092] The liquid crystal medium according to the invention preferably comprises one, two or more compounds of formula III-2. In a preferred embodiment the liquid crystal medium contains at least one compound of formula III-1 and at least one compound of formula III-2. In a further preferred embodiment the liquid crystal medium contains at least one compound of formula III-2 and at least one compound of the formula III-3.
[0093] Preferably, the compounds of the formula III-1 selected from the group of compounds of formulae III-1-1 to III-1-10, preferably of formula III-1-6,
##STR00045##
in which [0094] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl 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, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1-6 C atoms, and L.sup.31 and L.sup.32 each, independently of one another, denote F or Cl, preferably both F.
[0095] Preferably, the compounds of the formula III-2 are selected from the group of compounds of formulae III-2-1 to III-2-10, preferably of formula III-2-6,
##STR00046##
in which [0096] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl 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, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1-6 C atoms, and L.sup.31 and L.sup.32 each, independently of one another, denote F or Cl, preferably both F.
[0097] Optionally the medium comprises one or more compounds of the formula IIIA-1 and/or IIIA-2
##STR00047##
[0098] in which L.sup.31 and L.sup.32 have the same meanings as given under formula III, (O) denotes O or a single bond, [0099] R.sup.IIIA denotes alkyl or alkenyl having up to 7 C atoms or a group Cy-C.sub.mH.sub.2m+1, [0100] m and n are, identically or differently, 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, [0101] Cy denotes a cycloaliphatic group having 3, 4 or 5 ring atoms, which is optionally substituted with alkyl or alkenyl each having up to 3 C atoms, or with halogen or CN, and preferably denotes cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl.
[0102] The compounds of formula IIIA-1 and/or IIIA-2 are contained in the medium either alternatively or in addition to the compounds of formula III, preferably additionally.
[0103] Very preferred compounds of the formulae IIIA-1 and IIIA-2 are the following:
##STR00048##
in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms or alternatively (CH.sub.2).sub.nF in which n is 2, 3, 4, or 5, preferably C.sub.2H.sub.4F.
[0104] In a preferred embodiment of the present invention, the medium comprises one or more compounds of formula III-3
##STR00049##
in which [0105] R.sup.31, R.sup.32 identically or differently, denote H, an alkyl or alkoxy radical having 1 to 15 C atoms, in which one or more CH.sub.2 groups in these radicals are optionally replaced, independently of one another, by CC, CF.sub.2O, OCF.sub.2, CHCH,
##STR00050##
O, COO or OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen.
[0106] The compounds of formula III-3 are preferably selected from the group of compounds of the formulae III-3-1 to III-3-10:
##STR00051##
[0107] in which R.sup.32 denotes alkyl having 1 to 7 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively (CH.sub.2).sub.nF in which n is 2,3,4, or 5, preferably C.sub.2H.sub.4F.
[0108] In a preferred embodiment of the present invention, the medium comprises one or more compounds of the formulae III-4 to III-6, preferably of formula III-5,
##STR00052##
in which the parameters have the meanings given above, R.sup.31 preferably denotes straight-chain alkyl having 1 to 7 C atoms and R.sup.32 preferably denotes alkoxy having 1 to 7 C atoms.
[0109] In a preferred embodiment the media according to the invention comprise one or more compounds of the formula III selected from the group of compounds of formulae III-7 to III-9, preferably of formula III-8,
##STR00053##
in which the parameters have the meanings given above, R.sup.31 preferably denotes straight-chain alkyl having 1 to 7 C atoms and R.sup.32 preferably denotes alkoxy having 1 to 7 C atoms.
[0110] In a preferred embodiment, the medium comprises one or more compounds of the formula IV,
##STR00054##
in which [0111] R.sup.41 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, preferably an n-alkyl radical, particularly preferably having 2, 3, 4 or 5 C atoms, and [0112] R.sup.42 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, both preferably having 2 to 5 C atoms, an unsubstituted alkenyl radical having 2 to 7 C atoms, preferably having 2, 3 or 4 C atoms, more preferably a vinyl radical or a 1-propenyl radical and in particular a vinyl radical, [0113] where the compounds of formula I are excluded from formula IV and its sub-formulae.
[0114] The compounds of the formula IV are preferably selected from the group of the compounds of the formulae IV-1 to IV-4,
##STR00055##
in which [0115] alkyl and alkyl, independently of one another, denote alkyl having 1 to 7 C atoms, preferably having 2 to 5 C atoms, [0116] alkenyl denotes an alkenyl radical having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably 2 C atoms, [0117] alkenyl denotes an alkenyl radical having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms, and [0118] alkoxy denotes alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms.
[0119] Preferably the medium contains in addition to the compounds of formula IV-2 one or more compounds selected from the compounds of the formulae IV-1 and IV-3.
[0120] Preferably, the medium comprises one or more compounds selected from the compounds of the formulae IV-1-1 to IV-1-4
##STR00056##
[0121] Very preferably, the medium according to the invention comprises the compound of formula IV-1-1.
[0122] Very preferably, the medium according to the invention comprises one or more compounds of the formulae IV-2-1 and/or IV-2-2
##STR00057##
[0123] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula IV-3,
##STR00058##
in which very preferably alkyl denotes an alkyl radical having 1 to 7 C atoms, in particular n-ethyl or n-propyl, very particularly n-propyl, and alkenyl denotes
##STR00059##
in which m is 0, 1 or 2, preferably 0, and n is 0, 1 or 2, preferably 0 or 1, [0124] in particular selected from the compounds of the formulae IV-3-1 to IV-3-6, very particularly preferably of the formula IV-3-2:
##STR00060##
[0125] In a preferred embodiment, the medium comprises, in particular in addition to the compounds of the formulae IV-3-1 to IV-3-6, one or more compounds of the formulae IV-3-7 to IV-3-9
##STR00061##
[0126] Preferably, the concentration of the compounds of the formulae IV-3-7 to IV-3-9 in the medium according to the invention is less than 5% or less than 4% or less than 3%, very preferably 0% to 1%, in particular 0%.
[0127] Very preferably, the medium according to the invention comprises one or more compounds of the formula IV-3 and one or more compounds of the formula IV-1, where the total concentration of the compounds of the formula IV-1 is in the range of from 1% to 30%.
[0128] Very preferably, the medium according to the invention comprises a compound of formula IV-4, in particular selected from the compounds of the formulae IV-4-1 to IV-4-3, in particular of the formula IV-4-3
##STR00062##
[0129] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula I selected from the compounds of the formulae I-1 to 1-4 in combination with one or more compounds selected from the group of compounds of the formulae IA-1 to IA-18:
##STR00063## ##STR00064## [0130] in which alkyl denotes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl.
[0131] The LC medium according to the invention preferably comprises one or more compounds of the formula IVa,
##STR00065##
in which [0132] R.sup.41 and R.sup.42 each, independently of one another, denote a straight-chain alkyl, alkoxy, alkenyl, alkoxyalkyl or alkenyloxy radical having up to 12 C atoms, and
##STR00066##
denotes
##STR00067## [0133] Z.sup.4 denotes a single bond, 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, C.sub.4H.sub.8, CFCF.
[0134] Preferred compounds of the formula IVa are indicated below:
##STR00068##
in which [0135] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms.
[0136] The medium according to the invention preferably comprises at least one compound of the formula IVa-1 and/or formula IVa-2, very preferably of formula IVa-2, in particular the compounds IVa-2 in which alkyl denotes n-propyl and alkyl* denotes methyl.
[0137] The proportion of compounds of the formula IVa in the mixture as a whole is preferably less than 5% by weight, very preferably less than 2% by weight. Preferably, the medium comprises one or more compounds of formula IVb-1 to IVb-3
##STR00069##
in which [0138] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, and [0139] alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms.
[0140] The proportion of the compounds of the formulae IV-1 to IV-3 in the mixture as a whole is preferably less than 3% by weight, in particular less than 2% by weight.
[0141] Of the compounds of the formulae IVb-1 to IVb-3, the compounds of the formula IVb-2 are particularly preferred.
[0142] Very particularly preferred biphenyls are
##STR00070##
in which alkyl* denotes an alkyl radical having 1 to 6 C atoms and preferably denotes n-propyl or n-butyl. The medium according to the invention particularly preferably comprises one or more compounds of the formulae IVb-1-1 and/or IVb-2-3.
[0143] In the compounds of the formula IVb-1-1 alkyl denotes preferably propyl, butyl and pentyl and most preferably propyl.
[0144] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula V
##STR00071##
in which [0145] R.sup.51, R.sup.52 denote alkyl having 1 to 7 C atoms, alkoxy having 1 to 7 C atoms, or alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms,
##STR00072##
denotes
##STR00073##
denotes
##STR00074## [0146] Z.sup.51, Z.sup.52 each, independently of one another, denote CH.sub.2CH.sub.2, CH.sub.2O, CHCH, CC, COO or a single bond, and [0147] n is 1 or 2.
[0148] The compounds of formula V are preferably selected from the compounds of the formulae V-1 to V-14:
##STR00075## ##STR00076##
[0149] in which R.sup.51 and R.sup.52 have the meanings indicated for formula V above.
[0150] R.sup.51 and R.sup.52 preferably each, independently of one another, denote straight-chain alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.
[0151] Preferred media comprise one or more compounds of the formulae V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12 and/or V-14.
[0152] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula Vb
##STR00077##
in which [0153] R.sup.51, R.sup.52 denote alkyl having 1 to 7 C atoms, alkoxy having 1 to 7 C atoms, or alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms,
##STR00078##
denotes
##STR00079##
denotes
##STR00080## [0154] Z.sup.51, Z.sup.52 each, independently of one another, denote CH.sub.2CH.sub.2, CH.sub.2O, CHCH, CC, COO or a single bond, and [0155] n is 2.
[0156] The compounds of formula Vb are preferably selected from the compounds of the formulae Vb-1 to Vb-2:
##STR00081##
[0157] In a preferred embodiment of the present invention the medium additionally comprises one or more compounds of formula VI
##STR00082##
in which R.sup.6 and R.sup.62 each, independently of one another, denote H, an alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S,
##STR00083##
CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another and R.sup.62 alternatively denotes F, Cl, CF.sub.3 or OCF.sub.3, preferably F, and L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 independently denote H or F, where at least one of L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 denotes F, and wherein the compounds of formula IIC and IIE are excluded.
[0158] The compounds of formula VI are preferably selected from the formulae VI-1 to VI-20, in particular from the formulae VI-1, VI-2, IV-4, VI-14, VI-19 and VI-20:
##STR00084## ##STR00085## ##STR00086##
in which R.sup.6 denotes a straight-chain alkyl or alkoxy radical having 1 to 6 C atoms, (O) denotes O or a single bond, and m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4. R.sup.6 preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.
[0159] Particular preference is given to compounds of the formulae VI-1, VI-2, VI-4, VI-19 and VI-20.
[0160] In a preferred embodiment of the present invention the medium additionally comprises one or more compounds of formula VIA
##STR00087##
in which R.sup.6 and R.sup.62 each, independently of one another, denote H, an alkyl radical having 1 to 7 C atoms or an alkenyl radical having 2 to 7 C atoms, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S,
##STR00088##
CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another and R.sup.62 alternatively denotes F, Cl, CF.sub.3 or OCF.sub.3, preferably F, and L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 independently denote H or F, where at least one of L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.65, and L.sup.66 denotes F and [0161] Z.sup.61 and Z.sup.62 independently denote a single bond, CH.sub.2CH.sub.2, CH.sub.2O, CHCH, CC, COO or CF.sub.2O but Z.sup.61 Z.sup.62.
[0162] Very preferably, the medium according to the invention comprises the compound of formula VIA-1 and/or formula X
##STR00089##
in which R.sup.6 and m have the meanings defined above and preferably R.sup.6 denotes methyl, ethyl, n-propyl, n-butyl, or n-pentyl, and m is 2, 3 or 4. In a particular preferred embodiment R.sup.6 denotes n-propyl and m denotes 2.
[0163] In a preferred embodiment of the present invention the medium additionally comprises one or more compounds of the formulae VII-1 to VII-9
##STR00090##
in which [0164] R.sup.7 denotes a straight-chain alkyl or alkoxy radical having 1 to 6 C atoms, or a straight chain alkenyl radical having 2 to 6 C atoms, and [0165] w is an integer from 1 to 6.
[0166] Particular preference is given to mixtures comprising at least one compound of the formula VII-9.
Further Preferred Embodiments are Listed Below
[0167] a) Liquid-crystalline medium comprising at least one compound of the formulae Z-1 to Z-8,
##STR00091##
in which R has the meanings of R.sup.2A in formula IIA and alkyl denotes a straight-chain alkyl radical having 1 to 6 C atoms.
[0168] In a preferred embodiment the liquid crystal mixtures according to the present invention contain at least one compound of formula Z-8. [0169] b) Preferred liquid-crystalline media according to the invention comprise one or more substances which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, the compounds of the formulae N-1 to N-5,
##STR00092##
in which R.sup.1N and R.sup.2N each, independently of one another, have the meanings indicated for R.sup.2A, preferably denote straight-chain alkyl, straight-chain alkoxy or straight-chain alkenyl, and [0170] 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.3O, 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, CF.sub.2O, OCF.sub.2, CH.sub.2 or a single bond. [0171] c) Preferred mixtures comprise one or more compounds selected from the group of the difluorodibenzochroman compounds of the formula BC, chromans of the formula CR, and fluorinated phenanthrenes of the formulae PH-1 and PH-2,
##STR00093##
in which R.sup.B1, R.sup.B2, R.sup.CR1, R.sup.CR2, R.sup.1, R.sup.2 each, independently of one another, have the meaning of R.sup.2A. c is 0, 1 or 2. R.sup.1 and R.sup.2 preferably, independently of one another, denote alkyl or alkoxy having 1 to 6 C atoms.
[0172] Particularly preferred compounds of the formulae BC and CR are the compounds BC-1 to BC-7 and CR-1 to CR-5.
##STR00094## ##STR00095##
in which [0173] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, and [0174] alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms.
[0175] Very particular preference is given to mixtures comprising one, two or three compounds of the formula BC-2, BF-1 and/or BF-2. [0176] d) Preferred mixtures comprise one or more indane compounds of the formula In,
##STR00096##
in which
[0177] R.sup.11, R.sup.12, and R.sup.13 each, independently of one another, denote a straight-chain alkyl, alkoxy, alkoxyalkyl or alkenyl radical having 1 to 6 C atoms, [0178] R.sup.12 and R.sup.13 alternatively denote halogen, preferably F,
##STR00097##
denotes
##STR00098## [0179] i denotes 0, 1 or 2.
[0180] Preferred compounds of the formula In are the compounds of the formulae In-1 to In-16 indicated below:
##STR00099## ##STR00100##
[0181] Particular preference is given to the compounds of the formulae In-1, In-2, In-3 and In-4. [0182] e) Preferred mixtures additionally comprise one or more compounds of the formulae L-1 to L-12.
##STR00101## ##STR00102##
in which [0183] R, R.sup.1 and R.sup.2 each, independently of one another, have the meanings indicated for R.sup.2A in formula IIA above, and alkyl denotes an alkyl radical having 1 to 6 C atoms. The parameter s denotes 1 or 2.
[0184] The compounds of the formulae L-1 to L-11 are preferably employed in concentrations of 5 to 15% by weight, in particular 5 to 12% by weight and very particularly preferably 8 to 10% by weight. [0185] f) Preferred mixtures additionally comprise one or more compounds of formula IIA-Y
##STR00103##
in which R.sup.11 and R.sup.12 have one of the meanings given for R.sup.2A in formula IIA above, and L.sup.1 and L.sup.2, identically or differently, denote F or CI and L.sup.3 denotes H or CH.sub.3.
[0186] Preferred compounds of the formula IIA-Y are selected from the group consisting of the following sub-formulae
##STR00104## ##STR00105##
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, and O denotes an oxygen atom or a single bond. 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.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2.
[0187] Particularly preferred compounds of the formula IIA-Y are selected from the group consisting of following sub-formulae:
##STR00106##
[0188] in which alkoxy and alkoxy* have the meanings defined above and preferably denote methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentyloxy. [0189] g) The medium additionally comprises one or more compounds selected from the compounds of formulae P-1 to P-4:
##STR00107##
in which [0190] R.sup.P denotes a straight-chain alkyl or alkoxy radical having 1-6 C atoms or an alkenyl radical having 2-6 C atoms, preferably alkyl, each of which is unsubstituted, or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may be replaced by O, S,
##STR00108##
CC, CF.sub.2O, OCF.sub.2, OCO or OCO in such a way that O atoms are not linked directly to one another; [0191] X.sup.P straight-chain alkyl having 1-6 C atoms, F, Cl, CF.sub.3, OCF.sub.2H, OCF.sub.3, OCHFCF.sub.3, OCF.sub.2CHFCF.sub.3, OCHCF.sub.2, preferably F, OCF.sub.3 or CF.sub.3, CH.sub.3, [0192] L.sup.P1, L.sup.P2 and L.sup.P3 each independently of one another denote H or F, and [0193] L.sup.P4 denotes H or CH.sub.3, preferably H.
[0194] Preferred compounds of the formulae P1 to P4 are listed in the following:
##STR00109##
wherein [0195] L.sup.P4 denotes H or CH.sub.3; [0196] R.sup.P has the meanings given above. Preferably R.sup.P denotes alkyl, cycloalkyl, cycloalkylalkyl or alkenyl, in particular ethyl, propyl, butyl, pentyl, cyclopropyl, cyclopentyl, 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.2CHCH, CH.sub.3(CH.sub.2).sub.3CHCH or CH.sub.3CHCH(CH.sub.2).sub.2 and alkyl denotes a straight-chain alkyl group having 1-6 carbon atoms.
[0197] The compounds of formula P-1 have stabilizing properties for the liquid crystal medium. In a preferred embodiment the medium according to the invention comprises at least one compound of formula P-1, more preferably of formula P-1a, preferably in an amount from 0.1 to 5% by weight, more preferably 0.4 to 2.5% by weight. [0198] h) The medium additionally comprises one or more compounds selected from the group consisting of the formulae PII and PIII:
##STR00110##
in which
[0199] R.sup.2 and R.sup.3 denote a straight-chain or branched alkyl or alkoxy radical that is unsubstituted or halogenated and has 1 to 15 C atoms, where one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by
##STR00111##
CC, CF.sub.2O, CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another,
##STR00112##
identically or differently, denote
##STR00113##
preferably
##STR00114## [0200] L.sup.21, L.sup.22, L.sup.31 and L.sup.32 identically or differently, denote H or F, preferably F, [0201] Y.sup.2 and Y.sup.3 identically or differently, denote H or CH.sub.3, [0202] X.sup.2 and X.sup.3 identically or differently, denote halogen, CN, halogenated alkyl or alkoxy with 1 to 3 C-atoms or halogenated alkenyl or alkenyloxy with 2 or 3 C-atoms, preferably F, Cl, OCF.sub.3 or CF.sub.3, most preferably F, CF.sub.3 or OCF.sub.3, [0203] Z.sup.3 denotes 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, most preferably COO, and [0204] l, m, n and o are, independently of each other, 0 or 1, [0205] preferably l+m is 2.
[0206] Preferred compounds of the formula PIII are of formula PIII-1
##STR00115##
in which [0207] R.sup.3 denote a straight-chain or branched alkyl radical that is unsubstituted or halogenated and has 1 to 15 C atoms, where one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by
##STR00116##
CC, CF.sub.2O, CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another, [0208] L.sup.31 and L.sup.32 identically or differently, denote H or F, preferably F, [0209] Y.sup.3 identically or differently, denote H or CH.sub.3, [0210] X.sup.3 identically or differently, denote halogen, CN, halogenated alkyl or alkoxy with 1 to 3 C-atoms or halogenated alkenyl or alkenyloxy with 2 or 3 C-atoms, preferably F, CN, OCF.sub.3 or CF.sub.3, most preferably F or CN, and [0211] n independently is 0 or 1, preferably n is 0.
[0212] Preferably in PIII and PIII-1 the groups independently denote one or more of: [0213] X.sup.3 denotes CN, [0214] L.sup.31 denotes F, [0215] L.sup.32 denotes H, [0216] n denotes 0, [0217] L.sup.33, L.sup.34 denote H, and [0218] Y.sup.3 denotes H.
[0219] Preferably, the liquid crystal medium according to the invention comprises one or more compounds of the formula H
##STR00117##
in which [0220] A denotes an aliphatic, aromatic or heteroaromatic hydrocarbon group with q valencies and having 1 to 40 C atoms, preferably 6 to 30 C atoms; or a bond for q=2; [0221] Sp denotes a spacer group or a bond; [0222] R.sup.S denotes H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; [0223] Z.sup.S denotes O, C(O)O, (CH.sub.2).sub.z or (CH.sub.2).sub.zO, or a single bond; preferably C(O)O, [0224] HA denotes
##STR00118## [0225] R.sup.H denotes H, O, CH.sub.3, OH or OR.sup.S, preferably H or O.Math., [0226] R.sup.S1, R.sup.S2, R.sup.S3 and R.sup.S4, identically or differently, denote alkyl having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH.sub.3, [0227] G denotes H or R.sup.S or a group Z.sup.SHA, [0228] Z is an integer from 1 to 6, and [0229] q is 1, 2, 3 or 4, preferably 2.
[0230] In formula H, aryl preferably denotes an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms, comprising one, two, three or four aromatic rings including condensed rings that may be linked directly or via an alkylene linking group having 1 to 12 C atoms, in which one or more H atoms are optionally replaced with alkyl or alkoxy having 1 to 6 C atoms or alkenyl having 2 to 6 C atoms, or with CN, CF.sub.3 or halogen, and in which one or more CH.sub.2 groups may each, independently of one another, be replaced by O, S, NH, N(C.sub.1-C.sub.4-alkyl)-, CO, COO, OCO, OCOO, CHCH or CC in such a way that O or S atoms are not linked directly to one another.
[0231] Preferred aliphatic groups are alkylene, cycloalkylene, more preferably [0232] (CHR.sup.S5).sub.s, wherein R.sup.S5 is H or alkyl with 1 to 5 C atoms, and s is an integer from 1 to 20.
[0233] Preferred aryl groups are benzene, naphthalene, anthracene, biphenyl, m-terphenyl, p-terphenyl, and (phenylalkyl)benzene in which alkyl is straight chain alkyl having 1 to 12 C atoms.
[0234] The compounds of formula H are described in EP 3354710 A1 and EP 3354709 A1.
[0235] The compounds of formula H are preferably applied in a range of 0.1 to 0.3% (by weight).
[0236] In a preferred embodiment the medium comprises one or more compounds of formula H selected from compounds of formula H-A
##STR00119##
wherein [0237] A.sup.a denotes an alkylene group with 2 to 12 carbon atoms, wherein one or two CH.sub.2 groups may be replaced by 1,4-cyclohexylene, and [0238] R.sup.H denotes H or O.
[0239] The group A.sup.a preferably denotes
##STR00120## [0240] (CH.sub.2).sub.2, (CH.sub.2).sub.3, (CH.sub.2).sub.4, (CH.sub.2).sub.5, (CH.sub.2).sub.6, (CH.sub.2).sub.7, (CH.sub.2).sub.8, i.e. ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl,
##STR00121##
wherein [0241] S.sup.11 denotes an alkylene group having 1 to 20 C atoms,
[0242] The compounds of formula H are preferably selected from the compounds of the formulae H-1, H-2 and H-3:
##STR00122## ##STR00123##
in which R.sup.H has the meanings given above and preferably denote H or O.Math., and [0243] n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7, and [0244] Sp denotes a spacer group, preferably alkylene having 1 to 12 C atoms in which one or more non-adjacent CH.sub.2 groups may be replaced with O.
[0245] Preferred compounds of formula H-10 are selected from the compounds of the formula H-10-1.
##STR00124##
in which R.sup.H has the meanings given above and preferably denotes H or O.Math., and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.
[0246] Preferred compounds of formula H-11 are selected from the compounds of the formula H-11-1:
##STR00125##
[0247] in which R.sup.H has the meanings given above and preferably denotes H or O.Math., and n2, on each occurrence identically or differently, preferably identically, is an integer from 1 to 12, preferably 2, 3, 4, 5, or 6, very preferably 3, and R$ on each occurrence identically or differently, preferably identically, denotes alkyl having 1 to 6 C atoms, preferably n-butyl.
[0248] Preferred compounds of formula H-12 are selected from the compounds of the formula H-12-1:
##STR00126##
in which R.sup.H has the meanings given above and preferably denotes H or O.Math., and [0249] n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.
[0250] Preferred stabilizers H are the following:
##STR00127##
[0251] Preferably, the medium according to the invention comprises a compound selected from the group of compounds of the formulae ST-1 to ST-12:
##STR00128## ##STR00129##
in which [0252] R.sup.ST denotes H, an alkyl or alkoxy radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another by CC, CF.sub.2O, OCF.sub.2, CHCH,
##STR00130##
O, COO, OCO in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, preferably alkyl with 1-7 C atoms or cyclopentyl,
##STR00131##
on each occurrence, identically or differently, denotes
##STR00132## [0253] Z.sup.ST each, independently of one another, denote COO, OCO, CF.sub.2O, OCF.sub.2, CH.sub.2O, OCH.sub.2, CH.sub.2, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCH, CH.sub.2O, C.sub.2F.sub.4, CH.sub.2CF.sub.2, CF.sub.2CH.sub.2, CFCF, CHCF, CFCH, CHCH, CC or a single bond, [0254] L.sup.1 and L.sup.2 each, independently of one another, denote F, Cl, CH.sub.3, CF.sub.3 or CHF.sub.2, [0255] p denotes 0, 1 or 2, [0256] q denotes 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
[0257] Of the compounds of the formula ST, special preference is given to the compounds of the formulae ST-1 and ST-3 and in particular to any of the following:
##STR00133##
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=3
##STR00134##
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=1 or 7
##STR00135##
in which n=1, 2, 3, 4, 5, 6 or 7, preferably n=3
##STR00136##
[0258] Very particularly preferred mixtures according to the invention comprise one or more stabilizers from the group of the compounds of the formulae ST-1a, ST-1b-1 and ST-1c-1:
##STR00137##
[0259] The compounds of the formulae ST-1 to ST-12 are preferably each present in the liquid-crystal mixtures according to the invention in amounts of 0.1 to 0.5%, based on the mixture.
[0260] However, the total proportion of the compounds of the formulae ST-1 to ST-12, based on the mixture according to the invention, should not exceed 2%.
[0261] The medium according to the invention preferably has negative dielectric anisotropy.
Definitions
[0262] The term reliability as used herein means the quality of the performance of the display during time and with different stress loads, such as light load, temperature, humidity, voltage, and comprises display effects such as image sticking (area and line image sticking), mura, yogore etc. which are known to the skilled person in the field of LC displays. As a standard parameter for categorising the reliability usually the voltage holding ration (VHR) value is used, which is a measure for maintaining a constant electrical voltage in a test display. Among other factors, a high VHR is a prerequisite for a high reliability of the LC medium.
[0263] 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.
[0264] Unless indicated otherwise, the term LC display is used herein when referring to an information display based on switchable liquid crystals. It includes back-lit and reflective displays, for direct or indirect view, for virtual or augmented reality systems or projection systems. The size ranges from microdisplays to large screens. The addressing can be realized in that the LC display comprises simple electrodes on a substrate, an array of thin-film-transistors with electrodes for each pixel, or a structured silicon semiconductor as backplane, the latter of which is preferred.
[0265] As used herein, the terms optically active and chiral are synonyms for materials that are able to induce a helical pitch in a nematic host material, also referred to as chiral dopants.
[0266] Throughout the patent application, 1,4-cyclohexylene rings and 1,4-phenylene rings are depicted as follows:
##STR00138##
[0267] The cyclohexylene rings are trans-1,4-cyclohexylene rings.
[0268] Above and below,
##STR00139##
denotes a trans-1,4-cyclohexylene ring.
[0269] In a group
##STR00140##
the single bond shown between the two ring atoms can be attached to any free position of the benzene ring.
[0270] Above and below organic group denotes a carbon or hydrocarbon group.
[0271] 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.
[0272] Halogen denotes F, Cl, Br or I, preferably F or Cl. [0273] CO, C(O) and C(O) denote a carbonyl group, i.e.
##STR00141##
[0274] 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.
[0275] The terms alkyl, aryl, heteroaryl, etc., also encompass polyvalent groups, for example alkylene, arylene, heteroarylene, etc.
[0276] 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.
[0277] Herein, alkyl is straight-chain or branched and has 1 to 15 C atoms, is preferably straight-chain and has, unless indicated otherwise, 1, 2, 3, 4, 5, 6 or 7 C atoms and is accordingly preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.
[0278] Herein, branched alkyl is alkyl having a secondary and/or tertiary, preferably secondary, carbon atom and is preferably isopropyl, s-butyl, isobutyl, isopentyl, 2-methylhexyl or 2-ethylhexyl, 2-methylpropyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl.
[0279] Herein, a cyclic alkyl group is taken to mean a cycloaliphatic radical or an alkyl group in which a methylene group is replaced with a cycloaliphatic group (i.e. a cycloalkylalkyl or alkylcycloalkylalkyl), which may be saturated or partially unsaturated, and preferably denotes cyclopropyl, methylcyclopropyl, cyclobutyl, methylcyclobutyl, cyclopentyl, methylcyclopentyl, cyclopent-1-enyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, cyclopent-1-enylmethyl.
[0280] Herein, an alkoxy radical is straight-chain or branched and contains 1 to 15 C atoms. It is preferably straight-chain and has, unless indicated otherwise, 1, 2, 3, 4, 5, 6 or 7 C atoms and is accordingly preferably methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy or n-heptoxy.
[0281] Herein, an alkenyl radical is preferably an alkenyl radical having 2 to 15 C atoms, which is straight-chain or branched and contains at least one CC double bond. It is preferably straight-chain and has 2 to 7 C atoms. Accordingly, it is preferably vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl. If the two C atoms of the CC double bond are substituted, the alkenyl radical can be in the form of E and/or Z isomer (trans/cis). In general, the respective E isomers are preferred. Of the alkenyl radicals, prop-2-enyl, but-2-and-3-enyl, and pent-3-and-4-enyl are particularly preferred.
[0282] Herein, alkynyl is taken to mean an alkynyl radical having 2 to 15 C atoms, which is straight-chain or branched and contains at least one CC triple bond. 1- and 2-propynyl and 1-, 2- and 3-butynyl are preferred.
[0283] 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.
[0284] 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.
[0285] 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.
[0286] 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), C-, N(R.sup.x), O, S, CO, COO, OCO, OCOO in such a way that O and/or S atoms are not linked directly to one another.
[0287] 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.
[0288] 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.
[0289] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.
[0290] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.
[0291] 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.
[0292] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.,
[0293] 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.
[0294] 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.
[0295] 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.
[0296] 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, aza-carbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiophene, benzothiadiazothiophene, or combinations of these groups.
[0297] 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.
[0298] 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.
[0299] 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.
[0300] 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.
[0301] 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. [0302] NCSOCN Preferred substituents, hereinafter also referred to as L, are, for example, F, Cl, Br, I, CN, NO.sub.2, NCO, -, -, SCN, C(O)N(R.sup.x).sub.2, C(O)Y.sup.1, [0303] NCSOCNC(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, [0304] 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 PSp, and [0305] Y.sup.1 denotes halogen.
[0306] Substituted silyl or aryl preferably means substituted by halogen, CN, R.sup.0, OR.sup.0, COR.sup.0, COOR.sup.0, OCOR.sup.0 or OCOOR.sup.0, wherein R.sup.0 denotes H or alkyl with 1 to 20 C atoms.
[0307] Particularly preferred substituents L 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.
[0308] The LC medium according to the invention may additionally comprise one or more further components or additives, preferably selected from the list including but not limited to co-monomers, 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.
[0309] The LC media according to the invention may comprise one, two or three chiral dopants, preferably one chiral dopant.
[0310] Preferred embodiments, taken alone or in combination with one another, are listed below. The medium according to the invention preferably comprises [0311] the compound of formula I in a concentration in the range of from 2% to 20%, preferably of 3% to 16%, very preferably from 3% to 14%; [0312] the compound of formula IV-2 in a concentration in the range of from 4% to 20%, preferably of 5% to 15%, very preferably from 6% to 12%; [0313] the compound of formula ST-1 in a concentration in the range of from 0.11% to 0.85%, preferably of 0.15% to 0.40%, very preferably from 0.16% to 0.30%, or other combinations of these boundaries; [0314] the compound of formula H, preferably of the formula H-A, more preferably of formula H-1 in a concentration in the range of from 0.008% to 0.08%, preferably of 0.012% to 0.06%, very preferably from 0.015% to 0.04%; [0315] one or more compounds of the formula IIA, IIB, IIC, IID, IIE and Ill in a total concentration in the range of from 68% to 88%, more preferably from 70% to 85% and very preferably from 71% to 83%; [0316] one, two, three or more compounds of the formula III, preferably of the formula III-1 and/or III-2, more preferably of the formula III-2, in a total concentration in the range of from 0% to 15%, more preferably from 1% to 12%, very preferably from 2% to 10% and in particular from 3% to 8%; [0317] one or more compounds of the formula IIA in a total concentration in the range of from 15% to 50%, more preferably from 15% to 45% and very preferably from 35% to 43% or from 20% to 25%; [0318] one or more compounds of the formula IIA-2 in a total concentration in the range of from 3% to 18%, more preferably from 5% to 16% and very preferably from 5% to 16%; [0319] one or more compounds of the formula IIA-10 in a total concentration in the range of from 10% to 32%, more preferably from 12% to 30% and very preferably from 13% to 29%; [0320] one or more compounds selected from the compounds of formula IIC, more preferably of IIC-1 and IIC-2, preferably of the formula IIC-1, in a total concentration in the range of from 1% to 25%, more preferably from 4% to 25%, and very preferably from 8% to 22%; [0321] one or more compounds of the formula IIE, preferably of the formula IIE-1, in a total concentration in the range of from 1% to 18%, more preferably from 2% to 15%, and very preferably from 3% to 12%; [0322] one or more compounds of the formula IIB, preferably of the formula IIB-2 and/or IIB-10, in a total concentration in the range of from 7% to 30%, more preferably from 8% to 27% and very preferably from 9% to 26%; [0323] one or more compounds of the formula IIB-2 in a total concentration in the range of from 7% to 30%, more preferably from 8% to 27% and very preferably from 9% to 26%; [0324] one or more compounds of formula IIA and one or more compounds of formula IIB, preferably selected from the formulae IIA, -2, IIA-10, IIB-2 and IIB-10, preferably in a total concentration in the range of from 44% to 70%, more preferably from 45% to 68%, and very preferably from 40% to 67%; [0325] one or more compounds of the formula IV-1, preferably the compound IV-1-3, in a total concentration in the range of from 1% to 15%, more preferably from 2% to 12%, and very preferably from 5% to 12%; [0326] one or more compounds of the formula IV-3, preferably of the formula IV-3-2 and/or IV-3-5 in a total concentration in the range of from 1% to 25%, more preferably from 2% to 20%, and very preferably from 3% to 16%; [0327] two or more compounds of the formula I and formula IV in a total concentration in the range of from 18% to 30%, more preferably of 19% to 25%, and very preferably of 20% to 24%; [0328] two or more compounds of the formula I and the compound of the formula IV and the compounds of the formula V in a total concentration in the range of from 20% to 30%, more preferably from 20% to 28%, very preferably from 20% to 27%, and in particular from 21% to 27%; [0329] Particularly preferred mixture concepts are indicated below: (the acronyms used are explained in Tables A-D. n and m here each, independently of one another, denote 1-6).
[0330] The mixtures according to the invention preferably comprise [0331] PYP-n-m, in particular PYP-2-3 and/or PYP-2-4, [0332] preferably in concentrations >5%, in particular 8-30%, based on the mixture as a whole, [0333] and/or [0334] CPY-n-Om, in particular CPY-2-O2, CPY-3-O2 and/or CPY-5-O2, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole, and/or [0335] B-nO-Om and/or B(S)-nO-Om, preferably in concentrations of 1-15%, [0336] and/or [0337] CY-n-Om, preferably CY-3-O2, CY-3-O4, CY-5-O2 and/or CY-5-O4, preferably in concentrations >5%, in particular 15-50%, based on the mixture as a whole, [0338] and/or [0339] CCY-n-Om, preferably CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and/or CCY-5-O2, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole, [0340] and/or [0341] CLY-n-Om, preferably CLY-2-O4, CLY-3-O2 and/or CLY-3-O3, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole, and/or [0342] LY-n-Om, preferably LY-3-O2, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole, and/or [0343] CCOY-n-Om, preferably CCOY-3-O2, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole, and/or [0344] CLOY-n-Om, preferably CLOY-3-O2, preferably in concentrations >5%, in particular 10-30%, based on the mixture as a whole.
[0345] It is advantageous for the LC medium according to the invention to preferably have a nematic phase from 20 C. to 90 C., particularly preferably from 30 C. to 100 C., very particularly preferably from 40 C. to 105 C.
[0346] In a preferred embodiment, the medium according to the invention has a clearing temperature (clearing point) of 90 C. or more, more preferably of 100 C. or more, and in particular of 105 C. more.
[0347] Herein, the expression to have a nematic phase at a given temperature means that no smectic phase and no crystallisation is observed at low temperatures and on the other hand that clearing (phase transition to the isotropic phase) does not occur on heating of a nematic phase at a given temperature. The investigation at low temperatures is carried out in a flow viscometer at the corresponding temperature and checked by storage in test cells having a layer thickness corresponding to the electro-optical use for at least 100 hours. If the storage stability at a temperature of 20 C. in a corresponding test cell is 1000 h or more, the medium is referred to as stable at this temperature. At temperatures of 30 C. and 40 C., the corresponding times are 500 h and 250 h respectively. At high temperatures, the clearing point is measured by conventional methods in capillaries.
[0348] The liquid-crystal mixture preferably has a nematic phase range of at least 60 K and a flow viscosity v.sub.20 of at most 30 mm.sup.2.Math.s.sup.1 at 20 C.
[0349] The mixture is nematic at a temperature of 20 C. or less, preferably at 30 C. or less, very preferably at 40 C. or less.
[0350] The medium according to the invention has a birefringence in the range of from 0.085 to 0.170, preferably from 0.13 to 0.16, in particular from 0.14 to 0.16.
[0351] In a preferred embodiment, the medium has a birefringence in the range of from 0.1480 to 0.155, preferably from 0.147 to 0.153, in particular from 0.158 to 0.152.
[0352] In a preferred embodiment, the medium according to the invention has a dielectric anisotropy of 2.5 to 6.0, preferably of 2.8 to 4.7, in particular 3.5 to 4.5.
[0353] In a very preferred embodiment, the liquid-crystal mixture according to the invention has a dielectric anisotropy of 3.8 to 4.2.
[0354] The rotational viscosity .sub.1 at 20 C. is preferably in the range of from 90 to 300 mPa.Math.s, more preferably from 100 to 290 mPa s.
[0355] The medium according to the invention has an elastic constant K.sub.1 in the range of from 16 to 20 pN.
[0356] In a preferred embodiment, the medium according to the invention has a ratio of the rotational viscosity to the splay elastic constant .sub.1/K.sub.1 of 15 mPa.Math.s pN.sup.1 or less.
[0357] The liquid-crystal media according to the invention have relatively low values for the threshold voltage (V.sub.0). They are preferably in the range from 1.7 V to 3.0 V, particularly preferably 2.6 V and very particularly preferably 2.4 V.
[0358] For the present invention, the term threshold voltage relates to the capacitive threshold (V.sub.0), also called the Freedericks threshold, unless explicitly indicated otherwise.
[0359] In addition, the liquid-crystal media according to the invention have high values for the voltage holding ratio in liquid-crystal cells.
[0360] In general, liquid-crystal media having a low addressing voltage or threshold voltage exhibit a lower voltage holding ratio than those having a higher addressing voltage or threshold voltage and vice versa.
[0361] For the present invention, the term dielectrically positive compounds denotes compounds having a >1.5, the term dielectrically neutral compounds denotes those having 1.51.5 and the term dielectrically negative compounds denotes those having <1.5. The dielectric anisotropy of the compounds is determined here by dissolving 10% of the compounds in a liquid-crystalline host and determining the capacitance of the resultant mixture in at least one test cell in each case having a layer thickness of 20 m with homeotropic and with homogeneous surface alignment at 1 KHz. The measurement voltage is typically 0.5 V to 1.0 V, but is always lower than the capacitive threshold of the respective liquid-crystal mixture investigated.
[0362] All temperature values indicated for the present invention are in C.
[0363] The mixtures according to the invention are suitable for all VA-TFT applications, such as, for example, VAN, MVA, (S)-PVA, ASV, PSA (polymer sustained VA) and PS-VA (polymer stabilized VA). They are furthermore suitable for IPS (in-plane switching) and FFS (fringe field switching) applications having negative .
[0364] The mixtures are also particularly suitable for VA-TFT application of the LCoS type, more preferably LCoS microdisplays. LCoS microdisplays are reflective displays which typically contain a liquid-crystal layer having a nematic structure between a silicon backplane and a cover glass. The silicon backplane is an array of pixels, each of which has a mirrored surface which at the same time acts as electrical conductor. Each pixel comprises a stationary mirror covered by an active liquid-crystal layer having a twisted nematic alignment which can be switched between homeotropic and homogeneous alignment by application of a voltage. LCoS microdisplays are small, with a diagonal of typically less than 1.0, but enable high resolutions nevertheless.
[0365] Owing to the small pixel size, LCoS displays also have a very small cell thickness, which is typically about 1 micron. The liquid-crystalline phases used in these displays therefore have to have, in particular, high values for the optical anisotropy n, in contrast to conventional reflective-type LC displays, which usually require LC phases of low n.
[0366] In an preferred embodiment, the LCoS panel according to the invention comprises inorganic alignment layers, more preferably vertical alignment layers for vertical alignment of the liquid crystal medium. Most preferred are SiO.sub.x alignment layers. Such inorganic alignment layers are especially suitable for LCoS panels.
[0367] It goes without saying for the person skilled in the art that the VA, IPS or FFS mixture according to the invention may also comprise compounds in which, for example, H, N, O, Cl and F have been replaced by the corresponding isotopes.
[0368] The compounds according to the present invention can be synthesized by or in analogy to known methods described in the literature (for example in the standard works such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart), under reaction conditions which are known and suitable for said reactions. Use may also be made here of variants which are known per se, but are not mentioned here. In particular, they can be prepared as described in or in analogy to the following reaction schemes. Further methods for preparing the inventive compounds can be taken from the examples.
[0369] Other mesogenic compounds which are not explicitly mentioned above can optionally and advantageously also be used in the media in accordance with the present invention. Such compounds are known to the person skilled in the art.
[0370] For the present invention and in the following examples, the structures of the liquid-crystal compounds are indicated by means of acronyms, with the transformation into chemical formulae taking place in accordance with Tables A to C below. All radicals C.sub.mH.sub.2m+1, C.sub.nH.sub.2n+1, and C.sub.lH.sub.2l+1 or C.sub.mH.sub.2m1, C.sub.nH.sub.2n1 and C.sub.lH.sub.2l1 are straight-chain alkyl radicals or alkylene radicals, in each case having n, m and l C atoms respectively. Preferably n, m and l are independently of each other 1, 2, 3, 4, 5, 6, or 7. Table A shows the codes for the ring elements of the nuclei of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are composed of the codes for the ring elements with optional linking groups, followed by a first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group. Table D shows illustrative structures of compounds together with their respective abbreviations.
TABLE-US-00001 TABLE A Ring elements C
TABLE-US-00002 TABLE B Bridging unit E CH.sub.2CH.sub.2 V CHCH T CC W CF.sub.2CF.sub.2 B CFCF Z COO ZI OCO X CFCH XI CHCF O CH.sub.2O OI OCH.sub.2 Q CF.sub.2O QI OCF.sub.2
TABLE-US-00003 TABLE C End groups On the left individually or in combination On the right individually or in combination -n- C.sub.nH.sub.2n+1 -n C.sub.nH2.sub.n+1 nO C.sub.nH.sub.2n+1O On OC.sub.nH.sub.2n+1 V CH.sub.2CH V CHCH.sub.2 nV C.sub.nH.sub.2n+1CHCH nV C.sub.nH.sub.2nCHCH.sub.2 Vn CH.sub.2CHC.sub.nH.sub.2n Vn CH=CHC.sub.nH.sub.2n+1 nVm C.sub.nH.sub.2n+1CHCHC.sub.mH.sub.2m nVm C.sub.nH.sub.2nCHCHC.sub.mH.sub.2m+1 N NC N CN S SCN S NCS F F F F CL Cl CL Cl M CFH.sub.2 M CFH.sub.2 D CF.sub.2H D CF.sub.2H T CF.sub.3 T CF.sub.3 MO CFH.sub.2O OM OCFH.sub.2 DO CF.sub.2HO OD OCF.sub.2H TO CF.sub.3O OT OCF.sub.3 A HCC A CCH nA C.sub.nH.sub.2n+1CC An CCC.sub.nH.sub.2n+1 NA NCCC AN CCCN (cn)
in which n and m are each integers, and the three dots . . . are placeholders for other abbreviations from this table.
[0371] Apart from the compounds of formula IV-2, I and ST-1 the mixtures according to the invention optionally comprise one or more compounds of the compounds listed in Table D.
[0372] The following abbreviations are used: [0373] (n, m, k and l are, independently of one another, each an integer, preferably 1 to 9 preferably 1 to 7, k and I possibly may be also 0 and preferably are 0 to 4, more preferably 0 or 2 and most preferably 2, n preferably is 1, 2, 3, 4 or 5, in the combination -nO it preferably is 1, 2, 3 or 4, preferably 2 or 4, m preferably is 1, 2, 3, 4 or 5, in the combination -Om it preferably is 1, 2, 3 or 4, more preferably 2 or 4. The combination -IVm preferably is 2V1.)
TABLE-US-00004 TABLE D The following illustrative structures are examples as well as compounds, which are preferably additionally used in the media:
[0374] Table E shows chiral dopants which are preferably employed in the mixtures according to the invention.
TABLE-US-00005 TABLE E
[0375] In a preferred embodiment of the present invention, the media according to the invention comprise one or more compounds selected from the group of the compounds from Table E.
EXAMPLES
[0376] The present invention is illustrated in detail by the following non-restrictive working examples.
[0377] The following abbreviations and symbols are used: [0378] V.sub.0 threshold voltage, capacitive [V] at 20 C., [0379] n.sub.e extraordinary refractive index at 20 C. and 589 nm, [0380] n.sub.o ordinary refractive index at 20 C. and 589 nm, [0381] n optical anisotropy at 20 C. and 589 nm, [0382] .sub. dielectric permittivity perpendicular to the director at 20 C. and 1 kHz, [0383] .sub. dielectric permittivity parallel to the director at 20 C. and 1 kHz, [0384] dielectric anisotropy at 20 C. and 1 kHz, [0385] cl.p., T(N,I) clearing point [ C.], [0386] .sub.1 rotational viscosity at 20 C. [mPa.Math.s], [0387] K.sub.1 elastic constant, splay deformation at 20 C. [pN], [0388] K.sub.2 elastic constant, twist deformation at 20 C. [pN], [0389] K.sub.3 elastic constant, bend deformation at 20 C. [pN].
[0390] 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.
[0391] 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.
[0392] All physical properties are and have been determined in accordance with Merck Liquid Crystals, Physical Properties of Liquid Crystals, Status November 1997, Merck KGaA, Germany, and apply for a temperature of 20 C., and n is determined at 589 nm and at 1 KHz, unless explicitly indicated otherwise in each case.
[0393] 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).
[0394] 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.
[0395] The display used for measurement of the capacitive threshold voltage consists of two plane-parallel glass outer plates with a distance of 25 m, each of which has on the inside an electrode layer and an unrubbed polyimide alignment layer on top, which effect homeotropic alignment of the liquid-crystal molecules.
[0396] Unless indicated otherwise, the VHR is determined at 20 C. (VHR.sub.20) and after 5 minutes in an oven at 100 C. (VHR.sub.100) in a commercially available instrument Model LCM-1 (O0004) from TOYO Corporation, Japan. The voltage used has a frequency of in a range from 1 Hz to 60 Hz, unless indicated more precisely.
[0397] The stability to UV irradiation is investigated in a Suntest CPS+, a commercial instrument from Heraeus, Germany, using a Xenon lamp NXE1500B. The sealed test cells are irradiated for 2.0 h, unless explicitly indicated, without additional heating. The irradiation power in the wavelength range from 300 nm to 800 nm is 765 W/m.sup.2 V. A UV cut-off filter having an edge wavelength of 310 nm is used in order to simulate the so-called window glass mode. In each series of experiments, at least four test cells are investigated for each condition, and the respective results are indicated as averages of the corresponding individual measurements.
[0398] In order to investigate the low-temperature stability, also known as LTS, i.e. the stability of the LC mixture in the bulk against spontaneous crystallisation of individual components at low temperatures or the occurrence of smectic phases, as the case may be, several sealed bottles, each containing about 1 g of the material, are stored at one or more given temperatures, typically of 10 C., 20 C., 30 C. and/or 40 C. and it is inspected at regular intervals visually, whether a phase transition is observed or not. As soon as the first one of the samples at a given temperature shows a change time is noted. The time until the last inspection, at which no change has been observed, is noted as the respective LTS.
[0399] The ion density from which the resistivity is calculated is measured using the commercially available LC Material Characteristics Measurement System Model 6254 from Toyo Corporation, Japan, using VHR test cells with AL16301 Polyimide (JSR Corp., Japan) having a 3.2 m cell gap. The measurement is performed after 5 min of storage in an oven at 60 C. or 100 C.
[0400] The clearing point is measured using the Mettler Thermosystem FP900. The optical anisotropy (n) is measured using an Abbe Refractometer H005 (Natrium-spectral lamp Na10 at 589 nm, 20 C.). The dielectric anisotropy () is measured using an LCR-Meter E4980A/Agilent (G005) at 20 C. (-parallel-cells with JALS 2096-R1). The turn on voltage (V.sub.0) is measured using an LCR-Meter E4980A/Agilent (G005) at 20 C. (-parallel-cells with JALS 2096-R1). The rotational viscosity (1) is measured using a TOYO LCM-2 (0002) at 20 C. (gamma 1 negative cells with JALS-2096-R1). The elastic constant (K.sub.1, splay) is measured using an LCR-Meter E4980A/Agilent (G005) at 20 C. ( parallel-cells with JALS 2096-R1). K.sub.3: The elastic constant (K.sub.3, bend) is measured using an LCR-Meter E4980A/Agilent (G005) at 20 C. (-parallel-cells with JALS 2096-R1).
[0401] The following mixture examples having negative dielectric anisotropy are suitable, in particular, for vertically aligned liquid crystal displays.
Mixture Examples
[0402] The following stabilizing compounds are used and described with the acronyms as follows:
##STR00337##
[0403] The nematic LC mixtures M1 to M41 have the composition and physical properties given in the following tables:
Host Mixture M1
TABLE-US-00006 BCH-32 12.0% T.sub.(N, I) [ C.]: 111 CBC-33 1.5% n (589 nm, 20 C.): CCH-3O1 8.0% n.sub.e (20 C., 589.3 nm): CCY-3-O1 5.0% n.sub.o (20 C., 589.3 nm): CCY-3-O2 8.0% (1 kHz, 20 C.): CCY-3-O3 7.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 7.0% .sub. (1 kHz, 20 C.): CPY-3-O2 10.0% K.sub.1 [pN], (20 C.): CY-3-O2 11.5% K.sub.3 [pN], (20 C.): CY-3-O4 4.0% .sub.1 [mPa .Math. s], (20 C.): PYP-2-3 12.0% V.sub.0 [V], (20 C.): PYP-2-4 14.0% 100.0%
Example Mixture M2
TABLE-US-00007 M1 99.8% T.sub.(N, I) [ C.]: 111 ST-1a-1 0.2% n (589 nm, 20 C.): 0.151 100.0% n.sub.e (20 C., 589.3 nm): 1.649 n.sub.o (20 C., 589.3 nm): 1.497 (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): 3.7 .sub. (1 kHz, 20 C.): 7.7 K.sub.1 [pN], (20 C.): 17.3 K.sub.3 [pN], (20 C.): 17.5 .sub.1 [mPa .Math. s], (20 C.): 287 V.sub.0 [V], (20 C.): 2.21
Example Mixture M3
TABLE-US-00008 M1 99.77% T.sub.(N, I) [ C.]: 111 ST-1a-1 0.2% n (589 nm, 20 C.): 0.151 H-1 0.03% n.sub.e (20 C., 589.3 nm): 1.649 100.0% n.sub.o (20 C., 589.3 nm): 1.497 (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): 3.7 .sub. (1 kHz, 20 C.): 7.7 K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M4
TABLE-US-00009 BCH-32 12.0% T.sub.(N, I) [ C.]: 109 CBC-33 1.5% n (589 nm, 20 C.): 0.149 CCH-3O1 8.0% n.sub.e (20 C., 589.3 nm): CCY-3-O1 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-O2 8.0% (1 kHz, 20 C.): 4.0 CCY-3-O3 6.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 6.0% .sub. (1 kHz, 20 C.): CPY-3-O2 10.0% K.sub.1 [pN], (20 C.): CY-3-O2 11.5% K.sub.3 [pN], (20 C.): CY-3-O4 4.0% .sub.1 [mPa .Math. s], (20 C.): PYP-2-3 10.0% V.sub.0 [V], (20 C.): PYP-2-4 12.0% PPY-3-O2 4.0% CCEY-3-O2 3.0% 100.0%
Example Mixture M5
TABLE-US-00010 M4 99.77% T.sub.(N, I) [ C.]: 109 ST-1a-1 0.2% n (589 nm, 20 C.): 0.149 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M6
TABLE-US-00011 BCH-32 12.0% T.sub.(N, I) [ C.]: 112 CBC-33 1.5% n (589 nm, 20 C.): 0.150 CCH-3O1 8.0% n.sub.e (20 C., 589.3 nm): CCY-3-O1 5.0% n.sub.o (20 C., 589.3 nm): CCY-3-O2 8.0% (1 kHz, 20 C.): 4.0 CCY-3-O3 4.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 5.0% .sub. (1 kHz, 20 C.): CPY-3-O2 10.0% K.sub.1 [pN], (20 C.): CY-3-O2 11.5% K.sub.3 [pN], (20 C.): CY-3-O4 4.0% .sub.1 [mPa .Math. s], (20 C.): PYP-2-3 10.0% V.sub.0 [V], (20 C.): PYP-2-4 12.0% CCOY-3-02 5.0% PGP-2-4 4.0% 100.0%
Example Mixture M7
TABLE-US-00012 M6 99.77% T.sub.(N, I) [ C.]: 112 ST-1a-1 0.2% n (589 nm, 20 C.): 0.150 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M8
TABLE-US-00013 BCH-32 11.0% T.sub.(N, I) [ C.]: 109 CBC-33 1.5% n (589 nm, 20 C.): 0.150 CCH-3O1 8.0% n.sub.e (20 C., 589.3 nm): CCY-3-O1 5.0% n.sub.o (20 C., 589.3 nm): CCY-3-O2 8.0% (1 kHz, 20 C.): 4.0 CCY-3-O3 7.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 7.0% .sub. (1 kHz, 20 C.): CPY-3-O2 10.0% K.sub.1 [pN], (20 C.): CY-3-O2 10.0% K.sub.3 [pN], (20 C.): CY-3-O4 4.0% .sub.1 [mPa .Math. s], (20 C.): PYP-2-3 10.0% V.sub.0 [V], (20 C.): PYP-2-4 12.0% PGIGI-3-F 2.0% CBC-33F 1.5% PY-4-O2 2.0% 100.0%
Example Mixture M9
TABLE-US-00014 M8 99.77% T.sub.(N, I) [ C.]: 109 ST-1a-1 0.2% n (589 nm, 20 C.): 0.150 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M10
TABLE-US-00015 BCH-32 12.0% T.sub.(N, I) [ C.]: 112 CCH-3O1 9.0% n (589 nm, 20 C.): 0.150 CCY-3-O1 5.0% n.sub.e (20 C., 589.3 nm): CCY-3-O2 9.0% n.sub.o (20 C., 589.3 nm): CCY-3-O3 6.0% (1 kHz, 20 C.): 4.0 CCY-4-O2 6.0% .sub.|| (1 kHz, 20 C.): CPY-3-O2 12.0% .sub. (1 kHz, 20 C.): CY-3-O2 11.5% K.sub.1 [pN], (20 C.): CY-3-O4 4.0% K.sub.3 [pN], (20 C.): PYP-2-3 10.0% .sub.1 [mPa .Math. s], (20 C.): PYP-2-4 12.0% V.sub.0 [V], (20 C.): CPGP-5-2 3.0% PPGU-3-F 0.5% 100.0%
Example Mixture M11
TABLE-US-00016 M10 99.77% T.sub.(N, I) [ C.]: 112 ST-1a-1 0.2% n (589 nm, 20 C.): 0.150 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.0 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M12
TABLE-US-00017 BCH-32 4.0% T.sub.(N, I) [ C.]: 110 CCH-3O1 8.0% n (589 nm, 20 C.): CCH-34 10.5% n.sub.e (20 C., 589.3 nm): CCP-3-2 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-O1 5.0% (1 kHz, 20 C.): CCY-3-O2 5.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 5.0% .sub. (1 kHz, 20 C.): CPY-2-O2 12.0% K.sub.1 [pN], (20 C.): CPY-3-O2 12.0% K.sub.3 [pN], (20 C.): CY-3-O2 7.0% .sub.1 [mPa .Math. s], (20 C.): PGIY-2-O4 8.0% V.sub.0 [V], (20 C.): PYP-2-3 12.0% PYP-2-4 7.5% 100.0%
Example Mixture M13
TABLE-US-00018 M12 99.8% T.sub.(N, I) [ C.]: 110 ST-1a-1 0.2% n (589 nm, 20 C.): 0.150 100.0% n.sub.e (20 C., 589.3 nm): 1.647 n.sub.o (20 C., 589.3 nm): 1.500 (1 kHz, 20 C.): 3.9 .sub.|| (1 kHz, 20 C.): 3.7 .sub. (1 kHz, 20 C.): 7.6 K.sub.1 [pN], (20 C.): 18.3 K.sub.3 [pN], (20 C.): 17.1 .sub.1 [mPa .Math. s], (20 C.): 257 V.sub.0 [V], (20 C.): 2.20
Example Mixture M14
TABLE-US-00019 M12 99.77% T.sub.(N, I) [ C.]: 110 ST-1a-1 0.2% n (589 nm, 20 C.): 0.150 H-1 0.03% n.sub.e (20 C., 589.3 nm): 1.647 100.0% n.sub.o (20 C., 589.3 nm): 1.500 (1 kHz, 20 C.): 3.9 .sub.|| (1 kHz, 20 C.): 3.7 .sub. (1 kHz, 20 C.): 7.6 K.sub.1 [pN], (20 C.): 18.4 K.sub.3 [pN], (20 C.): 16.8 .sub.1 [mPa .Math. s], (20 C.): 258 V.sub.0 [V], (20 C.): 2.18
Host Mixture M15
TABLE-US-00020 BCH-32 4.0% T.sub.(N, I) [ C.]: 108 CCH-3O1 8.0% n (589 nm, 20 C.): 0.151 CCH-23 8.0% n.sub.e (20 C., 589.3 nm): CCP-3-1 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-O1 5.0% (1 kHz, 20 C.): 4.1 CCY-3-O2 7.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 5.0% .sub. (1 kHz, 20 C.): CPY-2-O2 12.0% K.sub.1 [pN], (20 C.): CPY-3-O2 12.0% K.sub.3 [pN], (20 C.): CY-3-O2 7.0% .sub.1 [mPa .Math. s], (20 C.): PGIY-2-O4 8.0% V.sub.0 [V], (20 C.): PYP-2-3 12.0% PYP-2-4 8.0% 100.0%
Example Mixture M16
TABLE-US-00021 M15 99.77% T.sub.(N, I) [ C.]: 108 ST-1a-1 0.2% n (589 nm, 20 C.): 0.151 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.1 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M17
TABLE-US-00022 BCH-32 4.0% T.sub.(N, I) [ C.]: 108 CCH-3O1 8.0% n (589 nm, 20 C.): 0.151 CCH-34 10.5% n.sub.e (20 C., 589.3 nm): CCP-3-1 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-O1 5.0% (1 kHz, 20 C.): 4.1 CCY-3-O2 5.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 5.0% .sub. (1 kHz, 20 C.): CPY-2-O2 11.0% K.sub.1 [pN], (20 C.): CPY-3-O2 11.0% K.sub.3 [pN], (20 C.): CY-3-O2 9.0% .sub.1 [mPa .Math. s], (20 C.): PGIY-2-O4 4.0% V.sub.0 [V], (20 C.): PYP-2-3 12.0% PYP-2-4 7.5% PPY-3-O2 4.0% 100.0%
Example Mixture M18
TABLE-US-00023 M17 99.77% T.sub.(N, I) [ C.]: 108 ST-1a-1 0.2% n (589 nm, 20 C.): 0.151 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.1 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M19
TABLE-US-00024 BCH-32 4.0% T.sub.(N, I) [ C.]: 109 CCH-3O1 8.0% n (589 nm, 20 C.): 0.147 CCH-34 10.5% n.sub.e (20 C., 589.3 nm): CCP-3-1 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-O1 5.0% (1 kHz, 20 C.): 4.4 CCY-3-O2 5.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 5.0% .sub. (1 kHz, 20 C.): CPY-2-O2 12.0% K.sub.1 [pN], (20 C.): CPY-3-O2 12.0% K.sub.3 [pN], (20 C.): CY-3-O2 7.0% .sub.1 [mPa .Math. s], (20 C.): PGIY-2-O4 2.0% V.sub.0 [V], (20 C.): PYP-2-3 12.0% PYP-2-4 7.5% B(S)-(c5)1O-O2 2.0% B(S)-2O-O6 2.0% B(S)-2O-O4 2.0% 100.0%
Example Mixture M20
TABLE-US-00025 M19 99.77% T.sub.(N, I) [ C.]: 109 ST-1a-1 0.2% n (589 nm, 20 C.): 0.147 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.4 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M21
TABLE-US-00026 BCH-32 2.0% T.sub.(N, I) [ C.]: 132 CBC-33 3.0% n (589 nm, 20 C.): CBC-33F 3.0% n.sub.e (20 C., 589.3 nm): CBC-53F 3.0% n.sub.o (20 C., 589.3 nm): CCH-3O1 2.0% (1 kHz, 20 C.): CCY-3-O1 5.0% .sub.|| (1 kHz, 20 C.): CCY-3-O2 6.0% .sub. (1 kHz, 20 C.): CCY-3-O3 5.1% K.sub.1 [pN], (20 C.): CCY-4-O2 6.0% K.sub.3 [pN], (20 C.): CPY-2-O2 13.0% .sub.1 [mPa .Math. s], (20 C.): CPY-3-O2 13.0% V.sub.0 [V], (20 C.): PPGU-3-F 1.0% PY-1-O4 1.9% PY-2-O2 5.0% PY-3-O2 7.0% PYP-2-3 12.0% PYP-2-4 12.0% 100.0%
Example Mixture M22
TABLE-US-00027 M21 99.8% T.sub.(N, I) [ C.]: 132 ST-1a-1 0.2% n (589 nm, 20 C.): 0.181 100.0% n.sub.e (20 C., 589.3 nm): 1.683 n.sub.o (20 C., 589.3 nm): 1.502 (1 kHz, 20 C.): 4.7 .sub.|| (1 kHz, 20 C.): 4.1 .sub. (1 kHz, 20 C.): 8.7 K.sub.1 [pN], (20 C.): 20.6 K.sub.3 [pN], (20 C.): 21.6 .sub.1 [mPa .Math. s], (20 C.): 496 V.sub.0 [V], (20 C.): 2.27
Example Mixture M23
TABLE-US-00028 M21 99.77% T.sub.(N, I) [ C.]: 132 ST-1a-1 0.2% n (589 nm, 20 C.): 0.181 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.7 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M24
TABLE-US-00029 CY-3-O2 7.5% T.sub.(N, I) [ C.]: CCY-3-O2 7.0% n (589 nm, 20 C.): CCY-4-O2 7.0% n.sub.e (20 C., 589.3 nm): CCY-3-O3 7.0% n.sub.o (20 C., 589.3 nm): CCY-5-O2 3.0% (1 kHz, 20 C.): CPY-2-O2 12.0% .sub.|| (1 kHz, 20 C.): CPY-3-O2 11.0% .sub. (1 kHz, 20 C.): PYP-2-3 13.0% K.sub.1 [pN], (20 C.): PYP-2-4 12.0% K.sub.3 [pN], (20 C.): CCH-301 8.0% .sub.1 [mPa .Math. s], (20 C.): PY-3-O2 3.5% V.sub.0 [V], (20 C.): BCH-32 9.0% 100.0%
Example Mixture M25
TABLE-US-00030 M24 99.67% T.sub.(N, I) [ C.]: 113 ST-1a-1 0.3% n (589 nm, 20 C.): 0.161 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.5 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): 18.5 K.sub.3 [pN], (20 C.): 18.2 .sub.1 [mPa .Math. s], (20 C.): 344 V.sub.0 [V], (20 C.): 2.11
Host Mixture M26
TABLE-US-00031 CY-3-O2 CY-3-O2 T.sub.(N, I) [ C.]: CCY-3-O2 CCY-3-O2 n (589 nm, 20 C.): CCY-4-O2 CCY-4-O2 n.sub.e (20 C., 589.3 nm): CCY-3-O3 CCY-3-O3 n.sub.o (20 C., 589.3 nm): CCY-5-O2 CCY-5-O2 (1 kHz, 20 C.): CPY-2-O2 CPY-2-O2 .sub.|| (1 kHz, 20 C.): CPY-3-O2 CPY-3-O2 .sub. (1 kHz, 20 C.): PYP-2-3 PYP-2-3 K.sub.1 [pN], (20 C.): PYP-2-4 PYP-2-4 K.sub.3 [pN], (20 C.): CCH-301 CCH-301 .sub.1 [mPa .Math. s], (20 C.): PY-3-O2 PY-3-O2 V.sub.0 [V], (20 C.): BCH-32 BCH-32 PPGU-3-F 1.0% 100.0%
Example Mixture M27
TABLE-US-00032 M26 99.67% T.sub.(N, I) [ C.]: 114.5 ST-1a-1 0.3% n (589 nm, 20 C.): 0.161 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.5 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): 18.6 K.sub.3 [pN], (20 C.): 18.2 .sub.1 [mPa .Math. s], (20 C.): 354 V.sub.0 [V], (20 C.): 2.11
Host Mixture M28
TABLE-US-00033 BCH-32 BCH-32 T.sub.(N, I) [ C.]: CCH-301 CCH-301 n (589 nm, 20 C.): CCH-34 CCH-34 n.sub.e (20 C., 589.3 nm): CCP-3-1 CCP-3-1 n.sub.o (20 C., 589.3 nm): CCY-3-O1 CCY-3-O1 (1 kHz, 20 C.): CCY-3-O2 CCY-3-O2 .sub.|| (1 kHz, 20 C.): CPY-2-O2 CPY-2-O2 .sub. (1 kHz, 20 C.): CPY-3-O2 CPY-3-O2 K.sub.1 [pN], (20 C.): CY-3-O2 CY-3-O2 K.sub.3 [pN], (20 C.): PGIY-2-O4 PGIY-2-O4 .sub.1 [mPa .Math. s], (20 C.): PY-3-O2 PY-3-O2 V.sub.0 [V], (20 C.): PYP-2-3 PYP-2-3 PYP-2-4 PYP-2-4 PPGU-3-F PPGU-3-F 100.0%
Example Mixture M29
TABLE-US-00034 M28 99.67% T.sub.(N, I) [ C.]: 103 ST-1a-1 0.3% n (589 nm, 20 C.): 0.161 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.6 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): 17.5 K.sub.3 [pN], (20 C.): 17.6 .sub.1 [mPa .Math. s], (20 C.): 284 V.sub.0 [V], (20 C.): 2.08
Example Mixture M30
TABLE-US-00035 BCH-32 11.98% T.sub.(N, I) [ C.]: 106 CCH-301 7.98% n (589 nm, 20 C.): 0.150 CCY-3-O1 4.99% n.sub.e (20 C., 589.3 nm): CCY-3-O2 4.99% n.sub.o (20 C., 589.3 nm): CCY-3-O3 5.99% (1 kHz, 20 C.): 4.0 CCY-4-O2 4.99% .sub.|| (1 kHz, 20 C.): CCY-5-O2 4.99% .sub. (1 kHz, 20 C.): CPY-3-O2 10.98% K.sub.1 [pN], (20 C.): 16.9 CY-3-O4 15.97% K.sub.3 [pN], (20 C.): 17.1 PYP-2-3 11.97% .sub.1 [mPa .Math. s], (20 C.): 287 PYP-2-4 14.97% V.sub.0 [V], (20 C.): 2.18 ST-1a-1 0.20% 100.0%
Host Mixture M31
TABLE-US-00036 CCY-3-O1 3.75% T.sub.(N, I) [ C.]: 94 CCY-3-O2 8.0% n (589 nm, 20 C.): 0.090 CCY-3-O3 8.0% n.sub.e (20 C., 589.3 nm): CCY-4-O2 8.0% n.sub.o (20 C., 589.3 nm): CCY-5-O2 8.0% (1 kHz, 20 C.): 4.8 CPY-3-O2 5.25% .sub.|| (1 kHz, 20 C.): CCY-2-1 8.5% .sub. (1 kHz, 20 C.): CCY-3-1 8.5% K.sub.1 [pN], (20 C.): CCH-301 18.5% K.sub.3 [pN], (20 C.): BCH-32 2.0% .sub.1 [mPa .Math. s], (20 C.): CY-5-O2 12.5% V.sub.0 [V], (20 C.): CY-5-O4 7.5% CY-3-O2 1.5 100.0%
Example Mixture M32
TABLE-US-00037 M31 99.67% T.sub.(N, I) [ C.]: 93 ST-1a-1 0.3% n (589 nm, 20 C.): 0.090 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.8 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): 246 V.sub.0 [V], (20 C.): 1.98
Example Mixture M33
TABLE-US-00038 M31 99.74% T.sub.(N, I) [ C.]: 93 ST-1a-1 0.2% n (589 nm, 20 C.): 0.090 ST-12 0.4% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 4.8 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): 246 V.sub.0 [V], (20 C.): 1.98
Host Mixture M34
TABLE-US-00039 BCH-32 5.0% T.sub.(N, I) [ C.]: CBC-33F 4.0% n (589 nm, 20 C.): CCH-301 7.0% n.sub.e (20 C., 589.3 nm): CCY-2-1 4.0% n.sub.o (20 C., 589.3 nm): CCY-3-1 5.0% (1 kHz, 20 C.): CCY-3-O2 8.0% .sub.|| (1 kHz, 20 C.): CCY-3-O3 8.0% .sub. (1 kHz, 20 C.): CCY-4-O2 7.0% K.sub.1 [pN], (20 C.): CPY-2-O2 12.0% K.sub.3 [pN], (20 C.): CPY-3-O2 12.0% .sub.1 [mPa .Math. s], (20 C.): CY-3-O2 15.0% V.sub.0 [V], (20 C.): CY-3-O4 5.0% PGIGI-3-F 8.0% 100.0%
Example Mixture M35
TABLE-US-00040 M34 99.67% T.sub.(N, I) [ C.]: 109.5 ST-1a-1 0.3% n (589 nm, 20 C.): 0.131 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 5.2 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M36
TABLE-US-00041 BCH-32 5.0% T.sub.(N, I) [ C.]: CBC-33F 4.0% n (589 nm, 20 C.): CBC-53F 3.0% n.sub.e (20 C., 589.3 nm): CCH-301 10.0% n.sub.o (20 C., 589.3 nm): CCY-3-O2 8.0% (1 kHz, 20 C.): CCY-3-O3 8.0% .sub.|| (1 kHz, 20 C.): CCY-4-O2 7.0% .sub. (1 kHz, 20 C.): CCY-5-O2 6.0% K.sub.1 [pN], (20 C.): CPY-2-O2 12.0% K.sub.3 [pN], (20 C.): CPY-3-O2 12.0% .sub.1 [mPa .Math. s], (20 C.): CY-3-O4 18.0% V.sub.0 [V], (20 C.): PYP-2-3 7.0% 100.0%
Example Mixture M37
TABLE-US-00042 M36 99.67% T.sub.(N, I) [ C.]: 119 ST-1a-1 0.3% n (589 nm, 20 C.): 0.131 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 5.1 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Host Mixture M38
TABLE-US-00043 BCH-32 16.0% T.sub.(N, I) [ C.]: CBC-33F 4.0% n (589 nm, 20 C.): CCH-301 5.0% n.sub.e (20 C., 589.3 nm): CCY-3-O2 8.0% n.sub.o (20 C., 589.3 nm): CCY-3-O3 8.0% (1 kHz, 20 C.): CCY-4-O2 7.0% .sub.|| (1 kHz, 20 C.): CPY-2-O2 12.0% .sub. (1 kHz, 20 C.): CPY-3-O2 12.0% K.sub.1 [pN], (20 C.): CY-3-O2 15.0% K.sub.3 [pN], (20 C.): CY-3-O4 11.0% .sub.1 [mPa .Math. s], (20 C.): CBC-53F 2.0% V.sub.0 [V], (20 C.): 100.0%
Example Mixture M39
TABLE-US-00044 M38 99.67% T.sub.(N, I) [ C.]: 114.5 ST-1a-1 0.3% n (589 nm, 20 C.): 0.131 H-1 0.03% n.sub.e (20 C., 589.3 nm): 100.0% n.sub.o (20 C., 589.3 nm): (1 kHz, 20 C.): 5.0 .sub.|| (1 kHz, 20 C.): .sub. (1 kHz, 20 C.): K.sub.1 [pN], (20 C.): K.sub.3 [pN], (20 C.): .sub.1 [mPa .Math. s], (20 C.): V.sub.0 [V], (20 C.):
Example Mixture M40
TABLE-US-00045 BCH-32 8.97% T.sub.(N, I) [ C.]: 113 CBC-33F 3.99% n (589 nm, 20 C.): 0.133 CBC-53F 2.99% n.sub.e (20 C., 589.3 nm): CCY-2-1 3.99% n.sub.o (20 C., 589.3 nm): CCY-3-1 3.99% (1 kHz, 20 C.): 5.2 CCY-3-O2 7.97% .sub.|| (1 kHz, 20 C.): CCY-3-O3 7.97% .sub. (1 kHz, 20 C.): CCY-4-O2 6.98% K.sub.1 [pN], (20 C.): CCY-5-O2 4.98% K.sub.3 [pN], (20 C.): CPY-2-O2 9.97% .sub.1 [mPa .Math. s], (20 C.): CY-3-O4 15.95% V.sub.0 [V], (20 C.): CY-5-O2 10.96% PGIGI-3-F 5.98% PGIY-2-O4 4.98% ST-1a-1 0.3% H-1 0.03% 100.0%
Example Mixture M41
TABLE-US-00046 BCH-32 5.99% T.sub.(N, I) [ C.]: 109 CCH-3O1 6.98% n (589 nm, 20 C.): 0.147 CCH-34 12.46% n.sub.e (20 C., 589.3 nm): CCP-3-1 3.99% n.sub.o (20 C., 589.3 nm): CCY-3-O1 4.99% (1 kHz, 20 C.): 4.4 CCY-3-O2 3.99% .sub.|| (1 kHz, 20 C.): CCY-4-O2 4.99% .sub. (1 kHz, 20 C.): CPY-2-O2 11.97% K.sub.1 [pN], (20 C.): CPY-3-O2 11.97% K.sub.3 [pN], (20 C.): CY-3-O2 4.99% .sub.1 [mPa .Math. s], (20 C.): PGIY-2-O4 2.00% V.sub.0 [V], (20 C.): PYP-2-3 11.97% PYP-2-4 7.48% B(S)-(c5en)1O-O4 2.00% B(S)-2O-O6 2.00% B(S)-(3)1O-O2 2.00% ST-1a-1 0.2% H-1 0.03% 100.0%
Example Mixture M42
TABLE-US-00047 CC-3-V 7.952% T.sub.(N, I) [ C.]: 121 CCH-301 7.952% n (589 nm, 20 C.): 0.271 CPGP-5-2 2.982% n.sub.e (20 C., 589.3 nm): 1.784 PGUQU-3-F 2.982% n.sub.o (20 C., 589.3 nm): 1.512 PGUQU-5-F 2.982% (1 kHz, 20 C.): 7.5 PPTUI-3-2 24.85% .sub.|| (1 kHz, 20 C.): 11 PPTUI-3-4 25.844% .sub. (1 kHz, 20 C.): 3.5 PUS-3-2 10.934% K.sub.1 [pN], (20 C.): PZG-4-N 5.964% K.sub.3 [pN], (20 C.): PZG-2-N 1.988% .sub.1 [mPa .Math. s], (20 C.): 290 CPTP-301 2.982% V.sub.0 [V], (20 C.): PTP-102 1.988% ST-1a-1 0.2% H-12 0.4% 100.0%
Stability Tests
[0404] The above Example Mixtures are subjected to test cells with inorganic alignment (SiO.sub.x) layers or to analogous LCoS panels. The devices are tested under enforced temperature and illumination (stress test blue light, >45 W/cm.sup.2, 70 C.). Occurrence of bubbles and dark stains is avoided over prolonged time. Alignment of the mixtures is found to be stable over prolonged time under these conditions. Stability for practical use in LCoS of the mixtures is improved over conventional mixtures.