Liquid crystal media and electronic components

Abstract

The Company provides liquid crystal media and electronic components. The invention relates to a) a liquid crystal medium comprising one or more compounds of formula I and one or more compounds of formula T and one or more compounds of formula S1, and to an electronic component which comprises said LC medium and which can operate in the visible (VIS), infrared (IR) or microwave region of the electromagnetic spectrum. The invention further relates to the use of said LC medium in the IR, VIS or microwave region and to a device which comprises said electronic component. TIFF2024518955000155.tif85166 (wherein the occurring groups and parameters have the meanings defined in claim 1.)

Description

[Technical field]

[0001] The present invention relates to a liquid crystal (LC) medium operable in the visible (VIS), infrared (IR) or microwave region of the electromagnetic spectrum and to electronic components comprising said LC medium. The invention further relates to the use of said LC medium in the IR, VIS or microwave region and to devices comprising said electronic components. [Background technology]

[0002] Liquid crystal media have been used for many years in electro-optical displays (LCDs (liquid crystal displays)) to display information by amplitude modulating polarized light in the visible range and are widely used in televisions, monitors or displays for portable devices such as tablet PCs and mobile phones.

[0003] Nematic liquid crystals have also been proposed for phase modulation of light. The article Mcmanamon PF, Dorschner TA, Corkum DL, Friedman LJ, Hobbs DS, Holz M, Liberman S, Nguyen HQ, Resler DP, Sharp RC, Watson EA, Optical phased array technology. Proc IEEE. 1996;84:268-298;doi:10.1109 / 5.482231 describes liquid crystal-based optical phased arrays for various types of sensor applications. The article "Liquid crystal waveguides: new devices enabled by >1000 waves of optical phase control" by Scott R. Davis, George Farca, Scott D. Rommel, Seth Johnson and Michael H. Anderson, Proc. SPIE7618, Emerging Liquid Crystal Technologies V, No. 76180E (February 12, 2010); doi:10.1117 / 12.851788, describes refractive beam steering using waveguide structures.

[0004] Liquid crystal on silicon (LCoS) is a small, reflective, active-matrix liquid crystal display or "microdisplay" that uses a layer of liquid crystal on top of a silicon backplane. It is also called a spatial light modulator (SLM).

[0005] The silicon backplane is an array of pixels, each with a mirrored surface and simultaneously acting as an electrical conductor. Each pixel contains a stationary mirror covered with an active liquid crystal layer with a twisted nematic alignment that can be switched to a homeotropic alignment by the application of a voltage. LCoS microdisplays are typically small, with a diagonal of less than 1.0 inch, but capable of high resolutions ranging from 1 / 4VGA (78 thousand pixels) to UXGA+ (over 2 million pixels).

[0006] Due to the small pixel size, LCoS displays also have a very small cell thickness, typically around 1 micron. A low cell thickness may also be required if the device is operated in reflective mode, since the light passes through the LC layer twice. The liquid crystal phases used in these displays must therefore have particularly high values ​​of optical anisotropy Δn, in contrast to conventional reflective LC displays, which usually require LC phases with low Δn. The response time decreases proportionally, often quadratically, with the cell thickness, so small cell thicknesses are preferably used for applications requiring particularly short response times.

[0007] Liquid crystal compounds with high birefringence often have an inherent smectic phase or can induce the formation of a smectic phase when mixed with other liquid crystal compounds, which has a detrimental effect on the low temperature stability of the display.

[0008] LCoS was initially developed for projection television, but is now also used for wavelength selective switches, structured lighting, near-eye displays and optical pulse shaping. Computer-generated holograms may be encoded on spatial light modulators arranged to modulate the amplitude and / or phase of incident light forming part of a holographic projector as described in WO 2020 / 015933. Such projectors have found application in head-up displays (HUDs) and head-mounted displays (HMDs), including near-eye devices.

[0009] Another application using liquid crystal based devices is Lidar (light detection and ranging), a method of measuring distance by shining a laser light on a target and measuring the reflection with a sensor. Differences in the reflection time and wavelength of the laser can then be used to create a digital three-dimensional representation of the target. WO 2019 / 24052 (Patent Document 2) proposes a holographic LIDAR system using, for example, an LCoS SLM.

[0010] One of the most important features of phase-only LCoS devices is the use of optically nonlinear liquid crystal materials that are sensitive to operating temperature. While conventional LCoS devices mainly focus on light intensity modulation, which is less susceptible to temperature changes, in phase-only LCoS devices, the optical phase modulation of the incident light is the essential performance parameter, which can be easily affected by slight changes in operating temperature, resulting in significant changes in the corresponding light diffraction output.

[0011] Another important challenge for the development of next-generation LCoS devices is the creation of fast multi-level phase modulation. Nematic LCoS devices offer the advantages of multi-level phase modulation, but are limited by the slow response speed of nematic LC. This is especially true for communication applications that require thicker devices using infrared wavelengths, thus resulting in even slower response speeds. Thus, the main material challenge in these applications is to find suitable fast LC materials that can perform the full 2π phase depth required in these applications.

[0012] Thus, there is a need for liquid crystal based optical components, particularly LCOS devices, that have high birefringence and high switching speeds, improving overall application relevant properties, and capable of operating in the visible or infrared regions of the electromagnetic spectrum. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. 2020 / 015933 [Patent Document 2] International Publication No. 2019 / 24052 [Non-patent literature]

[0014] [Non-Patent Document 1] Mcmanamon PF, Dorschner TA, Corkum DL, Friedman LJ, Hobbs DS, Holz M, Liberman S, Nguyen HQ, Resler DP, Sharp RC, Watson EA, Optical phased array technology.Proc IEEE.1996;84:268-298;doi:10.1109 / 5.482231 [Non-Patent Document 2] Scott R. Davis, George Farca, Scott D. Rommel, Seth Johnson, and Michael H. Anderson, "Liquid crystal waveguides: new devices enabled by >1000 waves of optical phase control," Proc.SPIE7618, Emerging Liquid Crystal Technologies V, No. 76180E (February 12, 2010);doi:10.1117 / 12.851788 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0015] The present invention has been devised in light of the problems in the prior art described herein.It is therefore a general object of the present invention to provide new and useful devices and techniques that can solve the problems described herein. [Means for solving the problem]

[0016] An object of the invention is a liquid-crystalline medium comprising a) one or more compounds of the formula I; and b) one or more compounds of the formula T; and c) one or more compounds of the formula S1.

[0017] [ka]

[0018] During the ceremony, R 11 and R 12 are the same or different and represent H, alkyl or alkoxy having 1 to 12 C atoms, or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, in which one or more CH groups are [ka] in which one or more H atoms may be replaced by halogen; L 11 , L 12 , L 13 are the same or different and represent H, CH3, Cl or F, A 11 represents phenylene-1,4-diyl, with the proviso that in addition one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3 or cyclohexane-1,4-diyl or cyclohexene-1,4-diyl, with the proviso that one or two non-adjacent CH2 groups may be replaced independently of one another by O and / or S and one or more H atoms may be replaced by F, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, A 12represents phenylene-1,4-diyl (with the proviso that in addition one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3 or cyclohexane-1,4-diyl or cyclohexene-1,4-diyl, with the proviso that one or two non-adjacent CH2 groups may be replaced independently of one another by O and / or S and one or more H atoms may be replaced by F), preferably phenylene-1,4-diyl (with the proviso that one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3 or cyclohexane-1,4-diyl), Z 1 represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCHO-, preferably a single bond; n is 0 or 1, preferably 1.

[0019] [ka]

[0020] During the ceremony, R 1 and R 2 represents H, F, Cl, Br, -CN, -SCN, -NCS, SF5 or a straight-chain or branched alkyl having 1 to 12 C atoms, with the proviso that one or more non-adjacent CH2 groups may each independently be replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O atoms are not directly linked to one another, with the proviso that one or more H atoms may be replaced by F, Cl or Br, A T1 , A T2 and A T3each independently represent phenylene-1,4-diyl, in which one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3, with the proviso that A T1 alternatively represents cyclohexane-1,4-diyl, in which one or two non-adjacent CH groups may be replaced independently of one another by O and / or S, and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, Z 1 and Z 2 each independently represents -CF2O-, -OCF2-, -CHO-, -OCH2-, -CO-O-, -O-CO-, -C2H4-, -C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or a single bond, preferably a single bond, t is 0 or 1, preferably 0.

[0021] [ka]

[0022] During the ceremony, R S1 and R S2 are each identically or differently H or a linear alkyl having 1 to 25 carbon atoms or a branched alkyl having 3 to 25 carbon atoms, which group is unsubstituted or monosubstituted with CN or CF3 or at least monosubstituted with a halogen, provided that one or more CH2 groups are each independently of one another such that O and / or S atoms are not directly linked to one another. [ka] -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C-) or halogen, aryl, heteroaryl, alkylaryl or arylalkyl having 6, 5, 7 or 7 to 25 carbon atoms, respectively (each of said groups is unsubstituted or mono- or polysubstituted with alkyl having 1 to 6 C atoms or halogen); s is 0, 1 or 2, and t is 0, 1, 2, or 3.

[0023] According to another aspect of the invention there is provided an electronic component comprising a liquid crystal medium according to the invention.

[0024] The invention further relates to a device comprising said electronic component.

[0025] The present invention further relates to the use of the medium as defined above and below for electro-optical purposes for the phase modulation of said visible or infrared light in the visible or infrared region of the electromagnetic spectrum, preferably in the region from 420 nm to 750 nm or in the A band and / or B band and / or C band. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 illustrates an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The medium according to the invention is characterized by a very high birefringence, and in spite of the high birefringence, excellent photostability is observed under blue light irradiation. The medium is further distinguished by a particularly high dielectric anisotropy and a low rotational viscosity. As a result, the threshold voltage, i.e. the minimum voltage at which the device can be switched, is very low. Low operating voltages and low threshold voltages are desired to enable devices with improved switching properties and high energy efficiency. The low rotational viscosity allows the components and devices according to the invention to be switched quickly.

[0028] The optical components according to the invention are distinguished by their excellent operational stability when exposed to the environment due to the high clearing temperature, the wide nematic phase range and the excellent low-temperature stability (LTS) of the liquid-crystalline media used. As a result, the components and devices containing them can be operated even under extreme temperature conditions. Surprisingly, the temperature dependence of the birefringence of the liquid-crystalline media is very small, i.e. Δn changes very little with temperature, making the devices reliable and easy to control.

[0029] The media according to the invention are likewise suitable for use in components and devices for applications in radio frequency technology and the microwave range, in particular in devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures and electronic beam steering antennas (e.g. phased array antennas).

[0030] Thus, according to another aspect of the invention there is provided a component and a device including said component, both operable in the microwave region of the electromagnetic spectrum. Preferred components are phase shifters, varactors, wireless and radio antenna arrays, matching circuits and adaptive filters.

[0031] Unless otherwise stated, the following definitions apply:

[0032] As used herein, halogen is F, Cl, Br or I, preferably F or Cl, particularly preferably F.

[0033] In this specification, alkyl is linear or branched and has 1 to 15 C atoms, preferably linear and, unless otherwise indicated, has 1, 2, 3, 4, 5, 6 or 7 C atoms, and is therefore preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

[0034] As used herein, branched alkyl is alkyl having secondary and / or tertiary, preferably secondary, carbon atoms, and is preferably isopropyl, sec-butyl, isobutyl, isopentyl, 2-methylhexyl or 2-ethylhexyl, 2-methylpropyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl.

[0035] In this specification, a cyclic alkyl group is intended to mean an alicyclic group or an alkyl group in which a methylene group is replaced by an alicyclic group (i.e., cycloalkylalkyl or alkylcycloalkylalkyl), which may be saturated or partially unsaturated, and preferably represents cyclopropyl, methylcyclopropyl, cyclobutyl, methylcyclobutyl, cyclopentyl, methylcyclopentyl, cyclopent-1-enyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, or cyclopent-1-enylmethyl.

[0036] In the present specification, an alkoxy group is linear or branched and contains 1 to 15 C atoms. It is preferably linear and, unless otherwise indicated, has 1, 2, 3, 4, 5, 6 or 7 C atoms, and is therefore preferably methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy or n-heptoxy.

[0037] In the present specification, an alkenyl group is preferably an alkenyl group having 2 to 15 C atoms, which group is linear or branched and contains at least one CC double bond. It is preferably linear and has 2 to 7 C atoms. It is thus 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 two C atoms of the CC double bond are substituted, the alkenyl group may be in the form of the E and / or Z isomers (trans / cis). Generally, the respective E isomers are preferred. Of the alkenyl groups, prop-2-enyl, but-2- and -3-enyl and pent-3- and -4-enyl are particularly preferred.

[0038] In the present specification, alkynyl is understood to mean an alkynyl group having 2 to 15 C atoms, which is linear or branched and contains at least one CC triple bond. 1- and 2-propynyl and 1-, 2- and 3-butynyl are preferred.

[0039] As used herein, the infrared region of the electromagnetic spectrum is intended to mean the spectral region of electromagnetic radiation having wavelengths within the range of 0.75 μm to 1000 μm.

[0040] As used herein, visible light is intended to mean light having a wavelength within the range of 420 nm to 750 nm.

[0041] As used herein, blue light is light having a peak wavelength within the range of 420 nm to 490 nm, preferably 450 nm to 460 nm.

[0042] As used herein, infrared A (IR-A) is intended to mean the spectral region of electromagnetic radiation having wavelengths within the range of 0.75 μm to 1.4 μm.

[0043] As used herein, infrared B (IR-B) is intended to mean the spectral region of electromagnetic radiation having wavelengths within the range of 1.4 μm to 3 μm.

[0044] As used herein, infrared-C (IR-C) is intended to mean the spectral region of electromagnetic radiation having wavelengths within the range of 3 μm to 1000 μm.

[0045] Preferably, the optical component according to the invention operates at wavelengths in the range from 750 nm to 2500 nm, in particular from 1530 nm to 1565 nm.

[0046] Highly preferred light sources for use according to the invention are IR lasers emitting light with a wavelength of 1.55 μm or IR lasers emitting light with a wavelength of 905 nm.

[0047] In this specification, "high frequency technology" refers to the use of electromagnetic radiation having a frequency within the range of 1 MHz to 1 THz, preferably 1 GHz to 500 GHz, more preferably 2 GHz to 300 GHz, and particularly preferably 5 GHz to 150 GHz.

[0048] The compounds of formula I are preferably selected from the group of formulae I-1 to I-3, particularly preferably from formula I-3.

[0049] [ka]

[0050] in which the occurring radicals have the respective meanings given above in formula I, and in formulae I-1 and I-2 preferably R 11 is n-alkyl or alkenyl having up to 7 C atoms, most preferably n-alkyl having 1 to 5 C atoms, R 12 is n-alkoxy or alkenyloxy having 1 to 6 C atoms, most preferably n-alkoxy having 1 to 4 C atoms, In I-3, preferably R 11 is n-alkyl or alkenyl having up to 7 C atoms, most preferably n-alkyl having 1 to 5 C atoms, R 12 is n-alkyl or alkenyl with up to 7 C atoms, most preferably n-alkyl with 1 to 5 C atoms.

[0051] The liquid crystal media according to the present invention preferably comprise one or more compounds of the formula I-1, preferably selected from the group of the compounds of the formulae I-1a to I-1d, preferably of the formulae I-1a and / or I-1d, most preferably of the formula I-1a.

[0052] [ka]

[0053] In the formula, R 11 and R 12 has the meaning given above.

[0054] The liquid crystal media according to the present invention preferably comprise one or more compounds of the formula I-2, preferably selected from the group of the compounds of the formulae I-2a to I-2f, preferably I-2a and / or I-2d, most preferably I-2a.

[0055] [ka]

[0056] In the formula, R 11 and R 12 has the meaning given above.

[0057] The liquid crystal medium according to the present invention preferably comprises one or more compounds of the formula I-3, preferably selected from the group of the compounds of the formulae I-3a to I-3d, preferably I-3a and / or I-3c and / or I-3d, most preferably I-3d.

[0058] [ka]

[0059] In the formula, R 11 and R 12 has the meaning given above.

[0060] Preferred compounds of formula T are selected from the group of formulae T1 to T5, with compounds of formula T1 being highly preferred.

[0061] [ka]

[0062] In the formula, R 1 and R 2 has the meaning given above for formula T, L 2 , L 3 , L 4 , L 5 and L 6 represents H or F. Preferably, L 2 stands for F, and L 4 , L 5 and L 6 stands for H, and L 3 represents H or F.

[0063] Highly preferred compounds of formula S1 are those which contain the group R S2 at least one of which is linear or branched alkyl having 1 to 15 carbon atoms (but in addition one or more CH groups may be replaced by -COO- or -O-CO-), aryl or alkylaryl having 5 to 15 carbon atoms, and X is preferably H or Cl. Very particularly preferred radicals R S2 are methyl, tert-butyl, 2-butyl, 1,1-dimethylpropyl, 1,1,2,2-tetramethylpropyl and 1-methyl-1-phenylethyl.

[0064] The compound of formula S1 is preferably selected from the compounds of formula S1-1.

[0065] [ka]

[0066] During the ceremony, R S1 represents H, F or Cl, preferably H or Cl, and R 21 and R 22 are the same or different and are H or linear or branched alkyl having 1 to 12 carbon atoms (provided that one or more CH2 groups are each independently connected such that the O atoms are not directly connected to each other). [ka] -O-, -CO-O-, -O-CO-, -CH=CH- or -C≡C-, or represents an aryl or arylalkyl having 6 to 25 carbon atoms.

[0067] Particularly preferred are compounds of formula S1-1 selected from the following formulae or mixtures of these compounds: Particularly preferred are compounds of formula S1-1a:

[0068] [ka]

[0069] [ka]

[0070] Further suitable UV stabilizers are selected from the following formulae:

[0071] [ka]

[0072] In a preferred embodiment of the invention, the medium comprises one or more compounds selected from the group consisting of formulae S2 and S3.

[0073] [ka]

[0074] During the ceremony, q is 1, 2, 3 or 4, preferably 2, 3 or 4, very preferably 2 or 4, G represents a hydrocarbon group, which may be linear, branched or cyclic, having 1 to 60 carbon atoms, which is unsubstituted or monosubstituted with CN or CF3 or at least monosubstituted with a halogen, provided that one or more CH2 groups are each independently -O-, -S-, -NR2-, -NR1-, -NR2-, -NR3-, -NR4-, -NR5-, -NR6-, -NR7-, -NR8-, -NR9-, -NR10-, -NR11-, -NR12-, -NR13-, -NR14-, -NR15-, -NR16-, -NR17-, -NR18-, -NR19-, -NR20-, -NR21-, -NR22-, -NR23-, -NR24-, -NR25-, -NR26-, -NR27-, -NR28-, -NR39-, -NR40-, -NR41-, -NR52 0 may be replaced by -, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C-, R 0 represents alkyl having 1 to 6 C atoms, R 2 -H, -O · , -OH, linear, branched or cyclic alkyl or alkoxy or arylalkoxy, each having 1 to 12 C atoms, preferably H or -O · represents R 21 and R 22 are the same or different, each independently representing a linear or branched alkyl residue having 1 to 12 carbon atoms, or R 21 and R 22 together with the carbon atom to which they are attached form a cycloalkyl group having 5 to 12 carbon atoms, R 23 and R 24 are the same or different, each independently representing a linear or branched alkyl residue having 1 to 12 carbon atoms, or R 23 and R 24 together with the carbon atom to which they are attached form a cycloalkyl group having 5 to 12 carbon atoms, Z 2 represents, identically or differently, -O-, -C(O)O-, -OC(O)- or a single bond in each occurrence; R ST represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, provided that one or more CH2 groups [ka] wherein one or more H atoms may be replaced by fluorine; Z ST each independently represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CHO-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond; [ka] each occurrence is identical or different and represents cyclohexane-1,4-diyl, cyclohexene-1,4-diyl, pyran-2,5-diyl, or 1,3-dioxane-2,5-diyl, provided that one or more H atoms may be replaced by F; p is 0, 1 or 2.

[0075] In formula S2, when q is 2, G can be a divalent linear or branched aliphatic residue (either saturated or unsaturated) having 2 to 20 carbon atoms, a divalent alicyclic residue having 5 to 20 carbon atoms, a divalent aralkyl residue having 8 to 20 carbon atoms, or a divalent aryl residue having 6 to 20 carbon atoms.

[0076] Examples of radicals G in which q is 2 are 1,2-ethylene, 1,2-propylene, 1,4-n-butylene, 1,3-butylene, 1,6-n-hexylene, 1,7-n-heptylene, 1,10-n-decylene, 1,12-n-dodecylene, 2,2-dimethyl-1,3-propylene, 1,2,3-trimethyl-1,4-butylene, 3-thia-1,5-pentylene, 3-oxa-1,5-pentylene, 1,4-buta- 2-enylene, 1,4-but-2-ynylene, 2,5-hex-3-enylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, hexahydro-p-xylylene, p-xylylene, m-xylylene, 1,2-phenylene, 1,4-phenylene, 2,2'-biphenylene, 4,4'-biphenylene, 2,6-naphthylene and 2,7-fluoroenylene.

[0077] In formula S2, when q is 3, G can be a trivalent linear or branched aliphatic residue (either saturated or unsaturated) having 3 to 15 carbon atoms, a trivalent alicyclic residue having 5 to 15 carbon atoms, a trivalent aralkyl residue having 9 to 15 carbon atoms, or a trivalent aryl residue having 6 to 16 carbon atoms.

[0078] Examples of groups G where q is 3 are 1,2,3-trisubstituted propane, 1,2,4-trisubstituted butane, 2,5-dimethyl-1,2,6-trisubstituted hexane, 1,1,1-trimethylenepropane, 1,2,3-trisubstituted cyclohexane, 1,3,5-trisubstituted cyclohexane, 1,3,5-trimethylenebenzene and 1,2,7-trisubstituted anthracene.

[0079] In formula S2, when q is 4, G can be a linear or branched tetravalent aliphatic residue (either saturated or unsaturated) having 4 to 60 carbon atoms or a tetravalent alicyclic residue having 5 to 60 carbon atoms, such as tetramethylenemethane or 1,1,4,4-tetramethylenecyclohexane or arylene-tetraalkylene or aralkylaryl-tetraalkylene.

[0080] When n is 2, 3 or 4 and G is an aliphatic or alicyclic residue, each of these residues may be unsubstituted or substituted with halogen or interrupted by one or more oxygen or sulfur atoms or aryl or aralkyl residues, where aryl includes fused rings such as naphthalene, one, two or more aryl groups linked via single bonds or alkylene groups.

[0081] base R 21 and R 22 And R 23 and R 24 Examples of R are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-hexyl, n-dodecyl, or together with the carbon to which they are attached, R 21 and R 22 And R 23 and R 24 teeth [ka] It is possible to form groups such as

[0082] Particularly preferred substituents R 21 and R 22 And R 23 and R 24 is a straight or branched alkyl group having 1 to 4 carbon atoms, most preferably methyl.

[0083] Highly preferred compounds of formula S2 are selected from subformulae S2-1 and S2-2.

[0084] [ka]

[0085] In the formula, G represents a divalent aliphatic or alicyclic group having 1 to 20 C atoms.

[0086] Examples of groups G in formula S2-1 or S2-2 are methylene, ethylene or polymethylene having up to 20 carbon atoms, which may be alkylated; or the alkylene group is interrupted by one or two heteroatoms, such as the divalent groups -CHOCH-, -CHCHOCHCH-, -CHCHOCHCHOCHCH-, -CHC(O)OCHCHO(O)CCH-, -CHCHC(O)OCHCHO(O)CCHCH-, -CHCH-C(O)O(CH2)4O(O)C-CHCH-, -CHCHO(O)C(CH2)4C(O)OCHCH- and -CHCHO(O)C(CH2)8C(O)OCHCH-. G can also be an arylene-bis-alkylene, such as p-xylylene, benzene-1,3-bis(ethylene), biphenyl-4,4'-bis(methylene) or naphthalene-1,4-bis(methylene).

[0087] Further highly preferred compounds of formula S2 are selected from the compounds of formula S2-3:

[0088] [ka]

[0089] During the ceremony, Sp is, in each occurrence, the same or different, a straight-chain or branched alkylene having 1 to 12 C atoms (provided that one or more CH2 groups may be replaced by O so that the O atoms are not directly linked to each other) or a single bond.

[0090] Particularly preferably, the medium comprises one or more compounds of formula S2-1a or S2-2a, preferably S2-1a.

[0091] [ka]

[0092] During the ceremony, R S3represents H or alkyl having 1 to 6 C atoms, preferably H or ethyl; t is 0 or 1, and q is 0, 1, 2, 3, 4, 5, 6, 7, 8 or 9; r is 2, 3, 4, 5, 6, 7 or 8, and s is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

[0093] Particularly preferably, the compounds of the formula S2 are selected from the compounds of the formulae S2-1a-1, S2-1a-2, S2-2a-1 and S2-3a-1, which are characterized by very good solubility in liquid-crystalline media.

[0094] [ka]

[0095] Further preferred examples of compounds of formula S2 are:

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] In the formula, R 2 has the meaning given above, preferably H or -O · Represents.

[0103] Among the compounds of formula S3, the compounds of formulas S3-1 to S3-4 are particularly preferred.

[0104] [ka]

[0105] [ka]

[0106] In a preferred embodiment, the medium according to the invention comprises one or more compounds selected from the group consisting of formulae II and III.

[0107] [ka]

[0108] During the ceremony, R 2 and R 3 represents an unsubstituted or halogenated linear or branched alkyl or alkoxy group having 1 to 15 C atoms, with the proviso that one or more CH2 groups in these groups are not directly linked to O atoms, [ka] may be replaced independently by -C≡C-, -CF2O-, -CH=CH-, -O-, -CO-O- or -O-CO-; [ka] are the same or different [ka] Preferably [ka] represents L 21 , L 22 , L 31 and L 32 are the same or different and represent H or F, preferably F; Y 2 and Y 3 are the same or different and represent H or CH3, X 2 and X 3 are the same or different and represent halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, preferably F, Cl, OCF3 or CF3, most preferably F, CF3 or OCF3, Z 3 represents -CH2CH2-, -CF2CF2-, -COO-, trans--CH=CH-, trans-CF=CF-, -CHO- or a single bond, preferably -CH2CH2-, -COO-, trans--CH=CH- or a single bond, most preferably -COO-, trans--CH=CH- or a single bond, and l, m, n and o are each independently 0 or 1, and preferably l+m is 2.

[0109] Preferably, the medium comprises one or more compounds of formula II, preferably selected from the group of compounds of formulae II-1 to II-3, very preferably selected from the group of compounds of formulae II-1 and II-3.

[0110] [ka]

[0111] In the formula, the occurring radicals have the respective meanings given in formula II above, and in formula II-1, the radical L 23 and L 24 each independently of the other and of the other parameters is H or F, and in formula II-1 is preferably [ka] Represents.

[0112] In formulas II-1, II-2 and II-3, L 21 and L 22 or L 23 and L 24 preferably both represent F.

[0113] In another preferred embodiment of formula II-1 and II-2, L 21 , L 22 , L 23 and L 24 All represent F.

[0114] The compound of formula II-1 is preferably selected from the group of the compounds of formulae II-1a to II-1h, preferably from II-1a, II-1b, II-1g and II-1h.

[0115] [ka]

[0116] [ka]

[0117] In the formulae, the occurring radicals have the respective meanings given above.

[0118] In a preferred embodiment of the present invention, the medium is 21 and L 22 and / or L 23 and L 24and R are each independently one or more compounds selected from the group of compounds of formulae II-1a to II-1h,

[0119] In another preferred embodiment, the medium is L 21 , L 22 , L 23 and L 24 The present invention also includes compounds selected from the group of compounds of formulae II-1a to II-1h, wherein all are F.

[0120] Particularly preferred are compounds of formula II-1.

[0121] [ka]

[0122] In the formula, R 2 has the meaning given above.

[0123] Preferably, the compound of formula II-2 is selected from the group of compounds of formulae II-2a to II-2c:

[0124] [ka]

[0125] In the formula, the occurring radicals have the respective meanings given above, preferably L 21 and L 22 Both are F.

[0126] Preferably, the compound of formula II-3 is selected from the group of compounds of formulae II-3a to II-3e, preferably from II-3d and II-3e.

[0127] [ka]

[0128] In the formula, the occurring radicals have the respective meanings given above, preferably L21 and L 22 Both are F and L 23 and L 24 are both H, or L 21 , L 22 , L 23 and L 24 are all F.

[0129] Particularly preferred are compounds of formula II-3.

[0130] [ka]

[0131] In the formula, R 2 has the meaning given above.

[0132] Compounds of formula II-3d-1 are highly preferred.

[0133] In addition to the preferred compounds of formula II above, the medium may contain one or more compounds of formula II selected from the compounds of formulae IIA1 to IIA7.

[0134] [ka]

[0135] In the formula, R 2 and X 2 has the meaning given in formula II or one of the preferred meanings given above and below.

[0136] Preferred compounds are of formulae IIA1, IIA2 and IIA3, very preferably of formulae IIA1 and IIA2.

[0137] In the compounds of formula IIA1 to IIA7, R 2 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or n-propyl, and X 2preferably represents F or OCF3, very preferably F.

[0138] In another preferred embodiment of the present invention, the medium comprises one or more compounds of formula III, preferably selected from the group of formulae III-1 and III-2, preferably formula III-2.

[0139] [ka]

[0140] wherein the occurring groups and parameters have the respective meanings given in formula III above.

[0141] Preferably, the compound of formula III-1 is selected from the group of compounds of formulae III-1a and III-1b.

[0142] [ka]

[0143] In the formula, the occurring radicals have the respective meanings given above, and L 33 and L 34 each independently represents H or F.

[0144] The compound of formula III-1a is preferably selected from the group of the compounds of formulae III-1a-1 to III-1a-6:

[0145] [ka]

[0146] In the formula, R 3 has the meaning given above.

[0147] Preferably, the compound of formula III-2 is selected from the group of compounds of formulae III-2a to III-2m.

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] In the formula, the occurring radicals have the respective meanings given above, and L 35 and L 36 represent independently H or F.

[0152] Preferably, the compound of formula II-2a is selected from the group of compounds of formulae III-2a-1 to III-2a-4.

[0153] [ka]

[0154] In the formula, R 3 has the meaning given above.

[0155] The compound of formula III-2b is preferably selected from the group of the compounds of formulae III-2b-1 and III-2b-2, preferably III-2b-2.

[0156] [ka]

[0157] In the formula, R 3 has the meaning given above.

[0158] The compound of the formula II-2c is preferably selected from the group of the compounds of the formulae III-2c-1 to III-2c-5.

[0159] [ka]

[0160] In the formula, R 3 has the meaning given above.

[0161] The compounds of the formulae III-2d and III-2e are preferably selected from the group of the compounds of the formulae III-2d-1, III-2d-2 and III-2e-1.

[0162] [ka]

[0163] In the formula, R 3 has the meaning given above.

[0164] The compound of formula III-2f is preferably selected from the group of the compounds of formulae III-2f-1 to III-2f-7:

[0165] [ka]

[0166] The compound of formula III-2g is preferably selected from the group of the compounds of formulae III-2g-1 to III-2g-7:

[0167] [ka]

[0168] In the formula, R 3 has the meaning given above.

[0169] The compound of the formula III-2h is preferably selected from the group of the compounds of the formulae III-2h-1 to III-2h-5:

[0170] [ka]

[0171] In the formula, R 3 has the meaning given above.

[0172] The compound of formula III-2i is preferably selected from the group of the compounds of formulae III-2i-1 to III-2i-3:

[0173] [ka]

[0174] In the formula, R 3 has the meaning given above.

[0175] The compound of formula III-2j is preferably selected from the group of the compounds of formulae III-2j-1 to III-2j-3:

[0176] [ka]

[0177] In the formula, R 3 has the meaning given above.

[0178] The compound of formula III-2k is preferably selected from the group of the compounds of formulae III-2k-1 to III-2k-6:

[0179] [ka]

[0180] In the formula, R 3 has the meaning given above.

[0181] The compound of formula III-2l is preferably selected from the group of the compounds of formulae III-2l-1 to III-2l-6:

[0182] [ka]

[0183] In the formula, R 3 has the meaning given above.

[0184] The compounds of formula III-2m are preferably selected from the compounds of formula III-2m-1.

[0185] [ka]

[0186] Alternatively, or in addition to the compounds of formula III-1 and / or III-2, the medium according to the invention may comprise one or more compounds of formula III-3, preferably III-3a.

[0187] [ka]

[0188] wherein the groups and parameters have the respective meanings given in Formula III above.

[0189] [ka]

[0190] In the formula, R 3 has the meaning given above.

[0191] In addition to the preferred compounds of formula III above, the medium may contain one or more compounds selected from the group consisting of formulae IIIA-1 to IIIA-21.

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] In the formula, R 3 and X 3 has the meaning given in formula III or one of the preferred meanings given above and below. Preferred compounds are those of the formulae IIIA1, IIIA4, IIIA6, IIIA16, IIIA19 and IIIA20.

[0197] Preferably, the medium according to the invention comprises one or more compounds of formula IV.

[0198] [ka]

[0199] During the ceremony, R 41 represents a linear alkyl group having 1 to 12 C atoms, or a branched or cyclic alkyl group having 3 to 12 C atoms, or a linear alkenyl group having 2 to 12 C atoms, or a branched alkenyl group having 3 to 12 C atoms, or a cyclic alkenyl group having 5 to 12 C atoms (wherein one or more H atoms may be replaced by fluorine), preferably a linear alkenyl group having 2 to 12 C atoms, R 42represents a linear alkyl or alkoxy group having 1 to 12 C atoms, or a branched or cyclic alkyl or alkoxy group having 3 to 12 C atoms, or a linear alkenyl group having 2 to 12 C atoms, or a branched alkenyl group having 3 to 12 C atoms, or a cyclic alkenyl group having 5 to 12 C atoms (wherein one or more H atoms may be replaced by fluorine), preferably a linear alkyl group having 1 to 12 C atoms, very preferably having 1 to 7 C atoms.

[0200] The compound of formula IV is preferably selected from the group of the compounds of the formulae IV-1 to IV-4, very preferably of the formula IV-3.

[0201] [ka]

[0202] During the ceremony, alkyl and alkyl' independently denote alkyl having 1 to 7 C atoms, preferably having 2 to 5 C atoms, alkoxy represents alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms, alkenyl represents an alkenyl group having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 C atoms, Alkenyl' represents an alkenyl group having 2 to 5 C atoms, preferably 2 to 4 C atoms, particularly preferably 2 to 3 C atoms.

[0203] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula IV selected from the group of compounds of formulae IV-1 to IV-4 in combination with one or more compounds selected from the group of compounds of formulae IVA-1 to IVA-18.

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] In the formula, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or n-pentyl.

[0208] Preferably, the medium comprises one or more compounds of formula IV-1, preferably selected from the compounds of formulae IV-1-1 to IV-1-6.

[0209] [ka]

[0210] Preferably, the medium according to the invention comprises one or more compounds of formula IV-2-1 and / or IV-2-2.

[0211] [ka]

[0212] Preferably, the medium according to the invention comprises a compound of the formula IV-3, very preferably selected from the compounds of the formulae IV-3-1 to IV-3-6, in particular the compounds of the formulae IV-3-2 and / or IV-3-6.

[0213] [ka]

[0214] Preferably, the medium according to the invention comprises a compound of formula IV-4, in particular selected from the compounds of formulae IV-4-1 and IV-4-2:

[0215] [ka]

[0216] Preferably, the medium according to the invention comprises one or more compounds of formula IVa and / or IVb.

[0217] [ka]

[0218] During the ceremony R 41 and R 42 have, independently of one another, the meaning defined above in formula IV, [ka] represents Z 4 represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8- or -CF=CF-.

[0219] Preferred compounds of formula IVa are selected from the compounds of formulae IVa-1 to IVa-4.

[0220] [ka]

[0221] During the ceremony Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 C atoms.

[0222] The medium according to the invention preferably comprises at least one compound of formula IVa-2.

[0223] Preferred compounds of formula IVb are selected from the compounds of formulae IVb-1 to IVb-3.

[0224] [ka]

[0225] During the ceremony Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 C atoms, alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 C atoms.

[0226] Among the compounds of the formulae IVb-1 to IVb-3, the compound of the formula IVb-2 is particularly preferred.

[0227] Particularly preferred compounds of formula IVb are selected from the following compounds:

[0228] [ka]

[0229] The medium according to the invention particularly preferably comprises the compound IVb-2-3.

[0230] Preferably, the medium according to the invention comprises one or more compounds of formula V

[0231] [ka]

[0232] During the ceremony, R 51 , R 52 represents an alkyl having 1 to 7 C atoms, an alkoxy having 1 to 7 C atoms, or an alkoxyalkyl having 2 to 7 C atoms, an alkenyl, or an alkenyloxy, [ka] represents Z 51 , Z52 each independently represents -CH-CH-, -CH-O-, -CH=CH-, -C≡C-, -COO- or a single bond; n is 1 or 2.

[0233] The compound of formula V is preferably selected from the compounds of formulae V1 to V17.

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] In the formula, R 1 and R 2 has the meaning given above in formula V. 1 and R 2 preferably each independently denote linear alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0238] Preferred media contain one or more compounds of formulae V-10, V-11, V-12, V-14, V-15, V-16 and / or V-17. Very preferably, the media contain one or more compounds of formulae V-10, V-16 and / or V-17, in particular V-10 and V-17.

[0239] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VI-1 to VI-9.

[0240] [ka]

[0241] [ka]

[0242] During the ceremony, R 7 are each independently R in claim 5. 2A has one of the meanings given in W and x each independently represent 1 to 6.

[0243] Particularly preferred are mixtures containing at least one compound of formula V-9.

[0244] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VII-1 to VII-21.

[0245] [ka]

[0246] [ka]

[0247] [ka]

[0248] During the ceremony, R represents a linear alkyl or alkoxy group having 1 to 6 C atoms, (O) represents O- or a single bond, m is 0, 1, 2, 3, 4, 5 or 6, n is 0, 1, 2, 3 or 4, and R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0249] Particularly preferred are compounds of formulae VII-1, VII-2, VII-4, VII-20 and VII-21. In these compounds R preferably represents alkyl, furthermore alkoxy, each having 1 to 5 C atoms. In compounds of formula VII-20 R preferably represents alkyl or alkenyl, in particular alkyl. In compounds of formula VII-21 R preferably represents alkyl.

[0250] In an embodiment of the invention the liquid crystal medium has a clearing point of 70° C. or more, more preferably 75° C. or more, even more preferably 80° C. or more or 85° C. or more, very preferably 90° C. or more and particularly preferably 100° C. or more.

[0251] In one embodiment, the medium comprises:

[0252] one or more compounds of formula I in a total concentration ranging from 10% to 60%, preferably from 15% to 55%, more preferably from 30% to 40%,

[0253] and one or more compounds of formula T in a total concentration ranging from 5% to 25%, preferably from 8% to 15%, more preferably from 10% to 20%,

[0254] and one or more compounds of formula S1 in a total concentration of more than 0% to 3%, preferably 0.1% to 2%, more preferably 0.15% to 1.5%, in particular 0.2% to 1%,

[0255] and preferably one or more compounds of formula II and / or III, more preferably formula II, with the total concentration of compounds of formula II and / or III being in the range of 15% to 45%, preferably 20% to 40%, more preferably 25% to 35%; compounds of formula II are preferably selected from formulae II-1a and II-1g and II-3d; the medium very preferably comprises one or more compounds of formulae II-1a and / or II-1g in a total concentration of 10% to 20%, in particular 12% to 17%, and one or more compounds of formula II-3d in a total concentration of 10% to 20%, in particular 12% to 17%;

[0256] and / or Preferably one or more compounds of formula IV, more preferably formula IV-3, with the total concentration of compounds of formula IV being in the range of 5-25%, preferably 7%-20%, very preferably 12%-17%; or one or more compounds of formula IV and IVa, preferably formula IV-3 and IVa-2, with the total concentration of compounds of formula IV being in the range of 2-20%, preferably 5%-15%, very preferably 8%-12%, and with the total concentration of compounds of formula IVa being in the range of 5-25%, preferably 7%-20%, very preferably 12%-17%, with the total concentration of compounds of formula IV and IVa being in the range of 10-40%, more preferably 15%-35%, very preferably 20%-30%.

[0257] In a preferred embodiment, the liquid-crystalline media according to the invention have a positive dielectric anisotropy Δε in the range from 6.0 to 20.0, preferably from 8.0 to 17.0, in particular from 10 to 13.

[0258] In a preferred embodiment, 589 nm (Na D ) and at 20° C., the birefringence (Δn) of the liquid crystal medium according to the present invention is in the range of 0.180 to 0.400, preferably 0.190 to 0.310, more preferably 0.200 to 0.300, and very preferably 0.210 to 0.260.

[0259] In another embodiment, the medium comprises:

[0260] one or more compounds of formula I in a total concentration ranging from 15% to 65%, preferably from 20% to 60%, more preferably from 35% to 45%,

[0261] and one or more compounds of formula T in a total concentration in the range of 2% to 30%, preferably 5% to 25%, more preferably 7% to 18%, very preferably 8% to 13%,

[0262] and one or more compounds of formula S1 in a total concentration of more than 0% to 3%, preferably 0.1% to 2%, more preferably 0.15% to 1.5%, in particular 0.2% to 1%,

[0263] and preferably one or more compounds of formula II and / or III, more preferably formula II, with the total concentration of compounds of formula II and / or III being in the range of 5% to 30%, preferably 8% to 20%, more preferably 10% to 16%; compounds of formula II are preferably selected from formulae II-1a and II-1g and II-3d; the medium very preferably comprises one or more compounds of formulae II-1a and / or II-1g in a total concentration of 2% to 15%, in particular 8% to 10%, and one or more compounds of formula II-3d in a total concentration of 1% to 10%, in particular 2% to 7%;

[0264] and / or Preferably one or more compounds of formula IV, more preferably formula IV-3, wherein the total concentration of compounds of formula IV is in the range of 3-20%, preferably 5-15%, very preferably 7-12%;

[0265] and / or Preferably one or more compounds of formula V, preferably selected from compounds of formula V-10 and V-17, in a total concentration in the range of 5% to 30%, more preferably 8% to 25%, very preferably 12% to 18%, with the proviso that the total concentration of compounds of formula V-10 is in the range of 2% to 20%, more preferably 4% to 13%, very preferably 5% to 10%, and with the proviso that the total concentration of compounds of formula V-17 is in the range of 2% to 20%, more preferably 4% to 13%, very preferably 5% to 10%.

[0266] In a preferred embodiment, the liquid-crystalline medium according to the invention has a positive dielectric anisotropy Δε in the range from 2.0 to 6.0, preferably from 3.0 to 5.0, in particular from 3.5 to 4.5.

[0267] In a preferred embodiment of the invention the liquid-crystalline medium has a clearing point of 120° C. or more, preferably 130° C. or more, particularly preferably 140° C. or more and very particularly preferably 150° C. or more.

[0268] The nematic phase of the media according to the invention preferably ranges from at least 0° C. to at least 90° C. Advantageously, the media according to the invention exhibit an even wider nematic phase range, preferably from at least −10° C. to at least 120° C., very preferably from at least −20° C. to at least 140° C., in particular from at least −30° C. to at least 150° C., and very particularly preferably from at least −40° C. to at least 170° C.

[0269] The tunability τ of the media according to the invention, measured at 20° C. and 19 GHz, is greater than or equal to 0.200, preferably greater than or equal to 0.210.

[0270] Preferred liquid crystal materials have a material quality (η) of 6 or more, preferably 8 or more, very preferably 10 or more, especially 15 or more.

[0271] Preferred liquid crystal materials in the corresponding components have a phase shift of more than 15° / dB, preferably more than 20° / dB, preferably more than 30° / dB, preferably more than 40° / dB, preferably more than 50° / dB, particularly preferably more than 80° / dB and very particularly preferably more than 100° / dB.

[0272] An electronic component is provided which comprises first and second substrates opposed to each other, wherein a liquid crystal medium according to the invention is sandwiched between said first and second substrates, and either one electrode is provided on each substrate, or two electrodes are provided on only one substrate, for applying an electrical potential across the liquid crystal material to drive the liquid crystal in a desired configuration.

[0273] In one embodiment, the electronic component is operable in the microwave region of the electromagnetic spectrum, where the liquid crystal medium within the component acts as a tunable dielectric and can be used in radio frequency technology.

[0274] Preferred components are liquid crystal based antenna elements, phase shifters, tunable filters, tunable metamaterial structures, matching networks or varactors.

[0275] A microwave antenna array is provided that includes one or more of the above components.

[0276] In another embodiment the electronic component is an optical component operable in the visible or infrared range of the electromagnetic spectrum, preferably a transmissive SLM.

[0277] In another preferred embodiment the optical component is a reflective SLM.

[0278] In the optical device component according to the invention, the light modulation elements (i.e. pixels) of the spatial light modulator are cells containing liquid crystals according to claim 1. That is, the spatial light modulator is a liquid crystal device and the optically active components are liquid crystals. Each liquid crystal cell is configured to selectively provide a plurality of light modulation levels. That is, each liquid crystal cell is always configured to operate at one light modulation level selected from a plurality of possible light modulation levels. Each liquid crystal cell is dynamically reconfigurable to different light modulation levels from the plurality of light modulation levels.

[0279] LCOS devices provide a dense array of light-modulating elements or pixels within a small aperture (e.g. a few centimetres wide). Typically the pixels are around 10 microns or less, resulting in diffraction angles of a few degrees, meaning that the optical system can be compact. LCOS devices are typically reflective, meaning that the circuitry driving the pixels of an LCOS SLM can be embedded below the reflective surface. This results in a higher aperture ratio. In other words the pixels are densely packed, meaning that there is very little dead space between them. This is advantageous as it reduces optical noise in the reproducing field. LCOS SLMs use a silicon backplane, which has the advantage that the pixels are optically flat. This is particularly important for phase modulating devices.

[0280] Thus, in a preferred embodiment, and referring to Figure 1, there is provided a reflective spatial light modulator, in particular an LCoS device 100, comprising a liquid crystal material 140 as defined above sandwiched between a transparent glass layer 110 having transparent electrodes 120, a mirror 150 mounted on a silicon CMOS back substrate 160 and a PCB mounting (not shown). The mirror is divided into a two-dimensional array of individually addressable pixels. Each pixel is individually drivable by a voltage signal to impart a localized phase change to at least one polarization component of the optical signal, thereby providing a two-dimensional array of phase manipulation regions. Pre-orientation of the liquid crystal 140 is provided by alignment layers 131 and 132.

[0281] Said LCOS devices are useful for integration into optical devices. The described LCOS SLMs output spatially modulated light in a reflective manner. Reflective LCOS SLMs have the advantage that the signal lines, gate lines and transistors are under the mirror surface resulting in a high fill factor (typically greater than 90%) and high resolution. Another advantage of using reflective LCOS spatial light modulators is that the thickness of the liquid crystal layer can be half that required when using transmissive devices. This greatly improves the switching speed of the liquid crystal (an important advantage in moving image projection). However, the teachings of this disclosure can be equally implemented using transmissive LCOS SLMs.

[0282] Examples of devices including optical components according to the present invention are holographic projectors, head-up displays including at least one holographic projection channel, driver monitoring systems for head-up displays, more preferably infrared holographic projectors for driver monitoring systems in vehicles, head-up displays, augmented reality head-up displays, "AR-HUDs" (including eye tracking or head tracking), image generation units and integrated infrared holographic illumination devices for head tracking or eye tracking.

[0283] Spatial light modulators may be used to display diffraction patterns including computer-generated holograms. If the hologram is a phase-only hologram, a spatial light modulator that modulates the phase is required. If the hologram is a fully complex hologram, a spatial light modulator that modulates the phase and amplitude may be used, or a first spatial light modulator that modulates the phase and a second spatial light modulator that modulates the amplitude may be used.

[0284] Other preferred devices are infrared imagers, wavelength selective switches, LCoS-SLMs, LIDAR systems, wavelength-division multiplex (WDM) systems, reconfigurable optical add-drop multiplexers (ROADM) and non-mechanical beam steering, e.g. steerable electro evanescent optical refraction (SEEOR) prisms as described in the article by P. McManamon, "Agile Nonmechanical Beam Steering", Opt. Photon. News, Vol. 17(No. 3): pp. 24-29, 2006.

[0285] The technology incorporates an SLM device and a red-green-blue (RGB) light source configured to emit red, green and blue light simultaneously or at different times (e.g., time-multiplexed RGB LEDs or laser diodes). In one example, the light source is an RGB light source using red, green and blue micro-LED arrays, for example as proposed in EP 3539157 A1.

[0286] RGB refers to the three primary colors of light, red, green and blue, which may form other colors and white. A conventional single LED may only transmit monochromatic (monochrome) light, which is one of these three primary colors. To create more colors, three LEDs may be used together to create an RGB mix. RGB LEDs are essentially three monochromatic LEDs, red, green and blue in color, placed close to each other, often in the same package. If all LEDs in an RGB-LED emit proportionally the same luminous intensity and the right kind of optics is used, the light emitted by the RGB-LED appears white to the human eye.

[0287] The use of an RGB light source avoids the exposure of the liquid crystal to UV light that is unavoidable when using conventional light sources such as cold cathode fluorescent lamps.

[0288] Thus, according to another aspect of the present invention there is provided an optical device comprising an RGB light source and an optical component as above, wherein upon operation of the optical device a phase of an incident light signal from said RGB light source is modulated by the component.

[0289] According to another aspect of the invention there is provided a method for spatially modulating visible or infrared light, comprising the steps of: i) providing an optical component comprising first and second substrates facing each other, each having a surface, the first substrate comprising at least a first electrode and the second substrate comprising at least a second electrode, the component further comprising a liquid crystal layer sandwiched between the first and second substrates, wherein the liquid crystal comprises one or more compounds selected from the compounds of formulae I, T and S1 shown above; ii) receiving incident infrared light at a surface of the optical component; iii) applying a predetermined voltage to each of the individual electrodes formed on the first substrate to modulate the refractive index of the liquid crystal layer; A method is provided that includes:

[0290] According to another aspect of the present invention, there is provided a method of manufacturing an optical phase modulator, comprising the steps of: a) providing a first substrate having a first electrode, which may have a two-dimensional array of individually electrically addressable cells; b) depositing a liquid crystal medium as defined in claim 1 on a first substrate; c) mounting a second substrate having a second electrode on the liquid crystal material; A method is provided that includes at least

[0291] The liquid crystal media according to the invention consist of a number of compounds, preferably 3 to 30, more preferably 4 to 20, very preferably 4 to 16. These compounds are mixed in the usual way. In general, the desired amount of the compound used in the smaller amount is dissolved in the compound used in the larger amount. It is particularly easy to observe the completion of the dissolution process if the temperature is above the clearing point of the compound used in the higher concentration. However, it is also possible to prepare the media using other conventional methods, so-called premixes, whose components are ready-to-use mixtures, for example, homogeneous mixtures or eutectic mixtures of compounds, or for example using the so-called "multi-bottle" system.

[0292] In the present invention and especially in the following examples, the structures of the mesogenic compounds are shown by abbreviations or acronyms. These acronyms are used in the following tables A to C to abbreviate the chemical formulae as follows: n H 2n+1 , C m H 2m+1 and C l H 2l+1 and C n H2 n-1 , C m H 2m-1 and C l H 2-1 represents a straight chain alkyl or alkenyl, respectively, having n, m and l C atoms, respectively, where n and m are independently 1, 2, 3, 4, 5, 6 or 7, and l is 1, 2 or 3. Table A lists the codes used for the ring elements of the core structure of the compounds, while Table B shows the linking and terminal groups. Table C shows exemplary structures of the compounds, together with their respective abbreviations.

[0293] <Table A: Ring elements>

[0294] [Table 1]

[0295] [Table 2]

[0296] [Table 3]

[0297] [Table 4]

[0298] [Table 5]

[0299] [Table 6]

[0300] <Table B: Crosslinking group>

[0301] [Table 7]

[0302] <Table B: Terminal group>

[0303] [Table 8]

[0304] In the table, n and m each represent an integer, and the three dots "..." are places for other abbreviations from this table.

[0305] The branched lateral chain groups are numbered starting from the position next to the ring (1) from which the longest chain is selected, with the smaller number indicating the length of the branch and the superscript number in parentheses indicating the position of the branch, e.g., below.

[0306] [ka] TIFF2024518955000104.tif51166

[0307] The following table shows exemplary structures with their respective abbreviations, which are presented to illustrate the meaning of the abbreviation rules, which further represent the preferred compounds to be used.

[0308] Table C: Exemplary Structures The following exemplary structures are examples and are preferred additionally used compounds in the medium.

[0309] [Table 9]

[0310] [Table 10]

[0311] [Table 11]

[0312] [Table 12]

[0313] [Table 13]

[0314] [Table 14]

[0315] [Table 15]

[0316] [Table 16]

[0317] [Table 17]

[0318] [Table 18]

[0319] [Table 19]

[0320] [Table 20]

[0321] [Table 21]

[0322] [Table 22]

[0323] [Table 23]

[0324] In the formula, m and n are the same or different and each is 1, 2, 3, 4, 5, 6, or 7.

[0325] Preferably, the medium according to the invention comprises one or more compounds selected from the compounds of Table C.

[0326] The following table, Table D, gives exemplary compounds which can be used as additional stabilizers in the mesogenic medium according to the invention. The total concentration of these and similar compounds in the medium is preferably 5% or less.

[0327]

[0328] [Table 24]

[0329] [Table 25]

[0330] [Table 26]

[0331] In a preferred embodiment of the invention the mesogenic medium comprises one or more compounds selected from the group of compounds in Table D.

[0332] The mesogenic medium according to the present application preferably comprises two or more, preferably four or more compounds selected from the group consisting of the compounds from the table above.

[0333] Preferably the medium comprises one or more chiral dopants in a concentration in the range of greater than 0% to 5%, preferably 0.01% to 4%, more preferably 0.1% to 3%, very preferably 0.2% to 2%, in particular 0.3% to 1%.

[0334] The mixtures according to the invention are all nematic. The liquid crystal media according to the invention preferably have a nematic phase in the preferred ranges given above. The expression "having a nematic phase" in this specification means, on the one hand, that at the corresponding temperatures no smectic phases and no crystallization are observed at low temperatures and, on the other hand, that no clearing occurs on heating from the nematic phase. At high temperatures, the clearing point is measured in a capillary tube in a conventional manner. Studies at low temperatures are carried out at the corresponding temperatures in a flow viscometer and are confirmed by storage of bulk samples: the storage stability (LTS) in bulk of the media according to the invention at a given temperature T is determined by visual inspection. 2 g of the medium to be studied are filled into a suitable sized sealed glass container (bottle) placed in a refrigerator at a given temperature. The bottles are checked at defined time intervals for the occurrence of smectic phases and / or crystallization. Two bottles are stored for each material and each temperature. If crystallization or the appearance of smectic phases is observed in at least one of the two corresponding bottles, the test is terminated and the last inspection time before the appearance of higher order phases is observed is recorded as the respective storage stability. Finally, the test is terminated after 1000 hours, i.e., an LTS value of 1000 hours means that the mixture is stable for at least 1000 hours at a given temperature.

[0335] The response time is the time for a change in relative tuning for the electro-optic response from 0% to 90%, respectively (t 90 -t0), i.e., delay time (t 10 -t0) including the rise time (τ on ) and the time (t 100 -t 10 ) versus decay time (τ off ) and the total response time (τ total = τ on +τ off ), respectively.

[0336] mp stands for melting point, T (N,I)denotes the clearing point of the liquid crystal material in degrees Celsius. Furthermore, K denotes the crystalline solid state, S denotes the smectic phase (the index indicates the type of phase), N denotes the nematic state, Ch denotes the cholesteric phase, I denotes the isotropic phase, and T denotes the smectic phase. g represents the glass transition temperature. The number between the two symbols indicates the transition temperature in degrees Celsius.

[0337] All temperatures are quoted in degrees Celsius, e.g. melting points T(C,N) or T(C,S), the transition from the smectic (S) to the nematic (N) phase T(S,N) and the clearing point of liquid crystals T(N,I). All temperature differences are quoted in degrees Celsius.

[0338] The host mixture used for the determination of the optical anisotropy Δn of the single compounds is the commercial mixture ZLI-4792 (Merck). The dielectric anisotropy Δε is determined using the commercial mixture ZLI-2857. The physical data for each compound studied are obtained from the change in the dielectric constant of the host mixture after the compound studied is added and extrapolated to 100% of the compound used. Depending on the solubility, typically 10% of the compound studied is dissolved in the host mixture.

[0339] Unless otherwise indicated, parts or percentage data refer to parts by weight or percentages by weight.

[0340] Above and below: V0 represents the capacitance threshold voltage [V] at 20°C. n e represents the extraordinary refractive index at 20°C and 589 nm, n0 represents the ordinary refractive index at 20° C. and 589 nm; Δn represents the optical anisotropy at 20° C. and 589 nm; ε ⊥ represents the dielectric constant perpendicular to the director at 20°C and 1 kHz, ε ∥ represents the dielectric constant parallel to the director at 20°C and 1 kHz, Δε represents the dielectric anisotropy at 20° C. and 1 kHz; cl.p., T(N,I) stands for clearing point [℃], γ1 represents the rotational viscosity [mPa s] measured at 20°C, K1 represents the elastic constant for "splay" deformation at 20°C [pN], K2 represents the elastic constant [pN] for the "twist" deformation at 20°C, K3 represents the elastic constant for "bend" deformation at 20°C [pN], and LTS (low-temperature stability) stands for low-temperature stability (nematic phase) determined in a test cell or in bulk, as specified.

[0341] The term "threshold voltage" for the present invention, unless otherwise specified, relates to the capacitive threshold (V0), also known as the Freedericks threshold. Also, in the examples, and as is generally customary, the threshold voltage is set to 10% relative contrast (V 10 ) may also be indicated.

[0342] The display used for measuring the capacitive threshold voltage consisted of two flat parallel glass outer plates spaced 20 μm apart, each plate having an electrode layer on its inner side and an unrubbed polyimide alignment layer on top, resulting in homeotropic edge alignment of the liquid crystal molecules.

[0343] The display or test cell used for measuring the tilt angle consists of two flat parallel glass outer plates spaced 4 μm apart, each with an electrode layer on the inside and a polyimide alignment layer on top, where the two polyimide layers are rubbed antiparallel to each other to produce a homeotropic edge alignment of the liquid crystal molecules.

[0344] Tilt angles are typically determined using a Mueller matrix polarimeter "AxoScan" manufactured by Axometrics, Inc. Herein, low values ​​(i.e., large deviations from a 90° angle) correspond to large tilts.

[0345] Unless otherwise specified, the term "tilt angle" refers to the angle between the LC director and the substrate, and "LC director" refers to the preferred orientation direction of the principal optical axes of the LC molecules in a layer of uniformly oriented LC molecules, which in the case of calamitic, uniaxial, positively birefringent LC molecules corresponds to their long molecular axis.

[0346] Unless otherwise stated, VHR is measured at 20°C (VHR 20 ) and after 5 min in a 100°C oven (VHR 100 ) on an instrument model LCM-1 (O0004) commercially available from Toyo Corporation, Japan. Unless expressly stated more precisely, the voltages used have frequencies within the range of 1 Hz to 60 Hz.

[0347] The stability against UV irradiation is investigated with "Suntest CPS+" by Heraeus GmbH, Germany, using a xenon lamp NXE1500B. The sealed test cells are irradiated for 2.0 h without additional heating unless explicitly stated. The irradiation power in the wavelength range from 300 nm to 800 nm is 765 W / m 2 V. To simulate the so-called window pane mode, a UV "cut-off" filter with an edge wavelength of 310 nm is used. For each condition in each experimental series, at least four test cells are considered and each result is presented as the average value of the corresponding individual measurements.

[0348] The degradation in voltage holding ratio (ΔVHR), typically caused by exposure to, for example, UV radiation or an LCD backlight, is determined according to equation (1) below.

[0349]

number

[0350] The ion density for calculating resistivity is measured using a commercially available LC Material Property Measurement System Model 6254 from Toyo Corporation, Japan, using a VHR test cell with AL16301 polyimide (JSR Corporation, Japan) and a cell gap of 3.2 μm. Measurements are taken after storage in an oven at 60°C or 100°C for 5 min.

[0351] The so-called "helical twisting power" (HTP) describes the helical twisting power of an optically active or chiral substance in an LC medium (unit: μm). Unless otherwise indicated, HTP is measured in a commercially available nematic LC host mixture MLC-6260 (Merck) at a temperature of 20°C.

[0352] The clearing point is measured using a Mettler Thermosystem FP900. The optical anisotropy (n) is measured using an Abbe refractometer H005 (sodium spectrum lamp Na10, 589 nm, at 20°C). The dielectric anisotropy (Δε) is measured using an LCR meter E4980A / Agilent (G005) at 20°C (ε-parallel cell with JALS2096-R1). The starting voltage (V0) is measured using an LCR meter E4980A / Agilent (G005) at 20°C (ε-parallel cell with JALS2096-R1). The rotational viscosity (γ1) is measured using a Toyo Corporation LCM-2 (0002) at 20°C (gamma 1 negative cell with JALS-2096-R1). Elastic constant (K1, splay) is measured at 20°C using LCR meter E4980A / Agilent (G005) (ε-parallel cell with JALS2096-R1). K3: Elastic constant (K3, bend) is measured at 20°C using LCR meter E4980A / Agilent (G005) (ε-parallel cell with JALS2096-R1).

[0353] Unless otherwise indicated, all concentrations in this application are given in weight percent with respect to the corresponding total mixture including all solid or liquid crystal components without solvent. All physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck KGaA, Germany, and apply at a temperature of 20°C unless otherwise indicated.

[0354] Liquid crystal media are considered with regard to their properties in the microwave frequency range as described in A. Penirschke et al., "Cavity Perturbation Method for Characterisation of Liquid Crystals up to 35 GHz", 34th European Microwave Conference - Amsterdam, pages 545-548. Comparison is also made to A. Gaebler et al., "Direct Simulation of Material Permittivites (omitted)", 12MTC2009 - International Instrumentation and Measurement Technology Conference, Singapore, 2009 (IEEE), pages 463-467 and DE 10 2004 029 429 A1, in which the measurement methods are likewise described in detail.

[0355] The liquid crystal is introduced into a cylindrical polytetrafluoroethylene (PTFE) or quartz capillary. The capillary has an inner diameter of 0.5 mm and an outer diameter of 0.78 mm. The effective length is 2.0 cm. The filled capillary is introduced into the center of a cylindrical cavity with a resonant frequency of 19 GHz. The cavity has a length of 11.5 mm and a radius of 6 mm. An input signal (signal source) is then applied and the resulting output signal is recorded using a commercial vector network analyzer (N5227A PNA Microwave Network Analyzer, Keysight Technologies, USA). For other frequencies, the dimensions of the cavity are adapted accordingly.

[0356] The change in resonant frequency and the Q factor between measurements with and without the capillary filled with liquid crystal are used to determine the dielectric constant and loss angle at the corresponding target frequency using equations 10 and 11 as described in the above mentioned publication by A. Penirschke et al., 34th European Microwave Conference-Amsterdam, pages 545-548.

[0357] The values ​​of the characteristic components perpendicular and parallel to the director of the liquid crystal are obtained by orienting the liquid crystal in a magnetic field. For this purpose, the magnetic field of a permanent magnet is used. The magnetic field strength is 0.35 Tesla.

[0358] The dielectric anisotropy in the microwave region is defined as follows.

[0359]

number

[0360] Adjustability (τ) is defined as follows:

[0361]

number

[0362] The material quality (η) is defined as follows:

[0363]

number

[0364] where the maximum dielectric loss is below.

[0365]

number

[0366] The following examples are intended to illustrate the present invention without limiting it. Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are therefore to be construed as merely illustrative, and are not intended to limit the remainder of the disclosure in any manner whatsoever. The following examples can be repeated with equal success by substituting the generally or specifically described reactants and / or operating conditions of the present invention for those used in the following examples. From the preceding description, one skilled in the art can readily ascertain the essential features of the present invention, and can make various changes and modifications to adapt the present invention to various applications and conditions without departing from the spirit and scope of the present invention.

[0367] <Mixture example M1>

[0368] [Table 27]

[0369] <Mixture example M2>

[0370] [Table 28]

[0371] <Mixture example M3> Medium M3 consists of 99.9% medium M1 and 0.1% compound S2-1a-1.

[0372] [ka]

[0373] <Mixture example M4> Medium M4 consists of 99.99% of medium M1 and 0.01% of compound S2-2a-1.

[0374] [ka]

[0375] <Mixture example M5> Medium M5 consists of 99.9% medium M2 and 0.1% compound S2-1a-1.

[0376] <Mixture example M6> Medium M4 consists of 99.99% medium M2 and 0.01% compound S2-2a-1.

[0377] Photostability test is performed with Honle LED Cube100IC with a peak wavelength of 460nm and 280mW / cm 2 The experiment is carried out using blue light at an irradiance of 1000 nm. The mixture is irradiated in an ITO cell with a cell gap of 6 μm and coated with polyimide (AL3046 (CT19320)), and the VHR is measured every 2 hours at a temperature of 60 °C and a frequency of 60 Hz. The results are shown in Table 1.

[0378] Table 1: VHR[%] (60℃, 60Hz, 1V)

[0379] [Table 29]

[0380] Mixtures M1-M6 have excellent stability under blue light irradiation, and their VHR values ​​are high enough for electronic device applications.

[0381] Mixture M7 contains compound S3-3a.

[0382] [ka]

[0383] <Mixture example M7>

[0384] [Table 30]

[0385] Medium M7 has advantageous properties for high frequency applications due to low dielectric loss and high tunability.

Claims

1. Liquid-crystalline medium comprising a) one or more compounds of the formula I; and b) one or more compounds of the formula T; and c) one or more compounds of the formula S1. 【Chemistry 1】 (In the formula, R １１ and R １２ are the same or different and represent H, alkyl or alkoxy having 1 to 12 C atoms, or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, in which one or more CH ２ The base is 【Chemistry 2】 in which one or more H atoms may be replaced by fluorine, L １１ , L １２ , L １３ are the same or different and may be H, CH ３ , Cl or F, A １１ represents phenylene-1,4-diyl, in which one or two CH groups may be replaced by N, and one or more H atoms are halogen, CN, CH ３ , C.H.F. ２ , C.H. ２ F, C.F. ３ , O.C.H. ３ , O.C.H.F. ２ or O.C.F. ３ , cyclohexane-1,4-diyl, or cyclohexene-1,4-diyl, provided that one or two non-adjacent CH ２ the radicals may be replaced independently of one another by O and / or S, one or more H atoms may be replaced by F, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, A １２ represents phenylene-1,4-diyl, in which one or two CH groups may be replaced by N, and one or more H atoms are halogen, CN, CH ３ , C.H.F. ２ , C.H. ２ F, C.F. ３ , O.C.H. ３ , O.C.H.F. ２ or O.C.F. ３ or cyclohexane-1,4-diyl or cyclohexene-1,4-diyl, provided that one or two non-adjacent CH ２ The groups may be replaced independently of one another by O and / or S, and one or more H atoms may be replaced by F, Z １ is a single bond, -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ --, --CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ -, -CF=CF- or -CH=CHCH ２ represents O-, n is 0 or 1. 【Chemistry 3】 (In the formula, R １ and R ２ is H, F, Cl, Br, -CN, -SCN, -NCS, SF ５ or represents a straight-chain or branched alkyl group having 1 to 12 C atoms, provided that there are one or more non-adjacent CH ２ the groups may each independently be replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, -O-CO- or -O-CO-O- in such a way that the O atoms are not directly linked to one another, with the proviso that one or more H atoms may be replaced by F, Cl or Br; A Ｔ１ , A Ｔ２ and A Ｔ３ each independently represents phenylene-1,4-diyl, with the proviso that one or two CH groups may be replaced by N, and one or more H atoms may be halogen, CN, CH ３ , C.H.F. ２ , C.H. ２ F, C.F. ３ , O.C.H. ３ , O.C.H.F. ２ or O.C.F. ３ may be replaced with, except A Ｔ１ Alternatively, represents cyclohexane-1,4-diyl, provided that one or two non-adjacent CH ２ the radicals may be replaced independently of one another by O and / or S, one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, Z １ and Z ２ are each independently -CF ２ O-, -OCF ２ --, --CH ２ O-, -OCH ２ -, -CO-O-, -O-CO-, -C ２ H ４ -, -C ２ F ４ -, -CF ２ CH ２ --, --CH ２ CF ２ -, -CFHCFH-, -CFHCH ２ --, --CH ２ CFH-, -CF ２ CFH-, -CFHCF ２ represents -, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or a single bond; t is 0 or 1. 【Chemistry 4】 (In the formula, R Ｓ１ and R Ｓ２ is, at each occurrence, the same or different, H or a linear alkyl having 1 to 25 carbon atoms or a branched alkyl having 3 to 25 carbon atoms (the group is unsubstituted or CN or CF ３ or at least monosubstituted with halogen, provided that one or more CH ２ The groups may each be independently selected such that the O and / or S atoms are not directly linked to each other. 【Chemistry 5】 -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C-), or halogen, aryl, heteroaryl, alkylaryl or arylalkyl, respectively, having 6, 5, 7 or 7 to 25 carbon atoms (each of said groups being unsubstituted or mono- or polysubstituted with alkyl or halogen having 1 to 6 C atoms), s is 0, 1 or 2, and t is 0, 1, 2 or 3.

2. 2. Liquid-crystalline medium according to claim 1, which comprises one or more compounds selected from the group of compounds of the formulae S2 and S3 【Chemistry 6】 (In the formula, q is 1, 2, 3 or 4; G represents a hydrocarbon group, which may be linear, branched or cyclic, having from 1 to 60 carbon atoms, said group being unsubstituted or selected from the group consisting of CN or CF ３ or at least monosubstituted with halogen, provided that one or more CH ２ The groups are each independently -O-, -S-, -NR in such a way that the O or S atoms are not directly linked to each other. ０ may be replaced by -, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C-, R ０ represents H or alkyl having 1 to 6 C atoms, R ２ is H, -O ・ , -OH, linear alkyl or alkoxy having 1 to 12 C atoms or branched or cyclic alkyl having 3 to 25 C atoms or arylalkoxy having 7 to 25 C atoms, R ２１ and R ２２ are the same or different and represent a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, or R ２１ and R ２２ together with the carbon atom to which they are attached form a cycloalkyl group having 5 to 12 carbon atoms, R ２３ and R ２４ are the same or different and represent a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, or R ２３ and R ２４ together with the carbon atom to which they are attached form a cycloalkyl group having 5 to 12 carbon atoms, Z ２ represents, identically or differently, —O—, —C(O)O—, —OC(O)—, or a single bond at each occurrence; R ＳＴ represents H, alkyl or alkoxy having 1 to 12 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 12 C atoms, provided that one or more CH ２ The basis is 【Chemistry 7】 with the proviso that one or more H atoms may be replaced by fluorine; Z ＳＴ are each independently -CO-O-, -O-CO-, or -CF ２ O-, -OCF ２ --, --CH ２ O-, -OCH ２ --, --CH ２ --, --CH ２ CH ２ -, -(CH ２ ) ４ -, -CH=CH-CH ２ O-, -C ２ F ４ --, --CH ２ CF ２ -, -CF ２ CH ２ represents -, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond; 【Chemistry 8】 each occurrence is identical or different and represents cyclohexane-1,4-diyl, cyclohexene-1,4-diyl, pyran-2,5-diyl, or 1,3-dioxane-2,5-diyl, in which one or more H atoms may be replaced by F; p is 0, 1 or 2.

3. 3. The liquid-crystalline medium according to claim 2, which comprises one or more compounds selected from the group of the compounds of the formulae S2-1 and S2-2 【Chemistry 9】 (In the formula, G represents a divalent aliphatic group having 1 to 20 C atoms or an alicyclic group having 3 to 20 C atoms.)

4. 2. The liquid-crystalline medium according to claim 1, which comprises one or more compounds selected from the group of the compounds of the formulae PT-1 to PT-3 【Chemistry 10】 (In the formula, R １１ , R １２ , Z １ , L １１ , L １２ and L １３ has the meaning given in claim 1.

5. 2. The liquid-crystalline medium according to claim 1, which comprises one or more compounds of the formula T selected from the group of the compounds of the formulae T1 to T5 【Chemistry 11】 (In the formula, R １ and R ２ has the meaning given in claim 1, L ２ ~L ６ represents H or F.)

6. 2. The liquid-crystalline medium according to claim 1, which comprises one or more compounds of the formula S1-1 【Chemistry 12】 (In the formula, R Ｓ１ represents H, F or Cl, and R ２１ and R ２２ are the same or different and each represents H or a straight or branched alkyl group having 1 to 12 carbon atoms (provided that one or more CH ２ The groups are each independently of one another such that the O atoms are not directly linked to one another. 【Chemistry 13】 -O-, -CO-O-, -O-CO-, -CH=CH- or -C≡C-, or represents an aryl or arylalkyl having 6 to 25 carbon atoms.

7. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds selected from the group consisting of the formulae II and III 【Chemistry 14】 (In the formula, R ２ and R ３ represents an unsubstituted or halogenated linear or branched alkyl or alkoxy group having 1 to 15 C atoms, provided that one or more CH ２ The group is such that the O atoms are not directly linked to each other. 【Chemistry 15】 -C≡C-, -CF ２ may be replaced independently by O—, —CH═CH—, —O—, —CO—O— or —O—CO—; 【Chemistry 16】 are the same or different 【Chemistry 17】 represents L ２１ , L ２２ , L ３１ and L ３２ are the same or different and represent H or F; Y ２ and Y ３ are the same or different and each represents H or CH ３ represents X ２ and X ３ are the same or different and represent halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, Z ３ is -CH ２ CH ２ -, -CF ２ CF ２ -, -COO-, trans--CH=CH-, trans-CF=CF-, -CH ２ represents O- or a single bond, l, m, n and o are each independently 0 or 1.

8. The medium of claim 1 comprising one or more compounds of formula IV: 【Chemistry 18】 (In the formula, R ４１ represents a linear alkyl group having 1 to 12 C atoms or a branched or cyclic alkyl group having 3 to 12 C atoms or a linear alkenyl group having 2 to 12 C atoms or a branched alkenyl group having 3 to 12 C atoms or a cyclic alkenyl group having 5 to 12 C atoms, with the proviso that one or more H atoms may be replaced by fluorine, R ４２ represents a linear alkyl or alkoxy group having 1 to 12 C atoms, or a branched or cyclic alkyl or alkoxy group having 3 to 12 C atoms, or a linear alkenyl group having 2 to 12 C atoms, or a branched alkenyl group having 3 to 12 C atoms, or a cyclic alkenyl group having 5 to 12 C atoms, with the proviso that one or more H atoms may be replaced by fluorine.

9. 2. The medium according to claim 1, comprising one or more compounds selected from the group of compounds of formulae IVa and IVb: 【Chemistry 19】 (In the formula, R 41 represents a linear alkyl group having 1 to 12 C atoms, or a branched or cyclic alkyl group having 3 to 12 C atoms, or a linear alkenyl group having 2 to 12 C atoms, or a branched alkenyl group having 3 to 12 C atoms, or a cyclic alkenyl group having 5 to 12 C atoms, with the proviso that one or more H atoms may be replaced by fluorine; R 42 represents a linear alkyl or alkoxy group having 1 to 12 C atoms, or a branched or cyclic alkyl or alkoxy group having 3 to 12 C atoms, or a linear alkenyl group having 2 to 12 C atoms, or a branched alkenyl group having 3 to 12 C atoms, or a cyclic alkenyl group having 5 to 12 C atoms, with the proviso that one or more H atoms may be replaced by fluorine; 【Chemistry 20】 represents Z ４ is a single bond, -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ --, --CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ -, -C ４ H ８ - or -CF=CF-.)

10. 1. An electronic component comprising first and second opposing substrates, a liquid crystal medium sandwiched between said first and second substrates, and an electrode provided on each substrate or two electrodes provided on only one of the substrates for applying an electrical potential across said liquid crystal medium to drive the liquid crystal in a predetermined configuration, 2. An electronic component, characterized in that the liquid crystal medium comprises a liquid crystal medium according to claim 1.

11. 11. An electronic component according to claim 10, wherein the liquid crystal medium within the component is arranged as a tunable dielectric configured for use in high frequency technology.

12. 11. The electronic component of claim 10, which is a liquid crystal based antenna element, a phase shifter, a tunable filter, a tunable metamaterial structure, a matching network or a varactor.

13. A microwave antenna array comprising one or more components according to claim 10.

14. 11. The component of claim 10, which is an optical component operable in the visible or infrared region of the electromagnetic spectrum.

15. 15. The component of claim 14, which is a transmissive spatial light modulator.

16. 15. The component of claim 14, wherein the component is a reflective spatial light modulator (100) configured to at least partially modulate the phase of an incident optical signal propagating in a first dimension, the first substrate being a transparent glass layer (110) having a first transparent electrode (120) and the second substrate being a CMOS silicon back substrate (160), the component further comprising a mirror (150) disposed between the second substrate and the liquid crystal medium (140), the mirror being arranged and configured as a second electrode (150) and divided into a two-dimensional array of individually addressable pixels, each pixel being individually driven by a voltage signal to provide a localized phase change to at least one polarization component of the optical signal.

17. an RGB light source, and The component of claim 14 , arranged and configured to modulate a phase of an incident optical signal from the RGB light source when the optical device is operated; Includes optical devices.

18. 1. A method for spatially modulating light, comprising: i) providing an optical component comprising first and second substrates facing each other and each having a surface, the first substrate comprising at least one first electrode and the second substrate comprising at least one second electrode, the component further comprising a liquid crystal layer sandwiched between the first and second substrates, the liquid crystal comprising a liquid crystal medium according to claim 1; ii) providing an RGB light source; ii) receiving incident light from the RGB light source at a surface of the optical component; iii) applying a predetermined voltage to each of the individual electrodes formed on the first substrate to modulate the refractive index of the liquid crystal layer; The method includes:

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