Optical Components

Abstract

Optical components are provided. The present invention relates to an optical component comprising a liquid crystal (LC) medium operable in the infrared region of the electromagnetic spectrum. The invention further relates to the use of said liquid crystal medium in the infrared (IR) region and to devices comprising said optical component. The invention further relates to an LC medium comprising one or more compounds of formulae I, II and III and preferably one or more compounds of formula RO. TIFF2023534174000298.tif73166 (wherein the occurring groups and parameters have the meanings defined in claim 1.) TIFF2023534174000299.tif42166 (wherein the occurring groups and parameters have the meanings defined in claim 2.)

Description

[Technical Field]

[0001] The present invention relates to an optical component comprising a liquid crystal (LC) medium operable in the infrared region of the electromagnetic spectrum. The invention further relates to the use of said liquid crystal medium in the infrared (IR) region and to devices comprising said optical component. [Background technology]

[0002] Liquid crystal media have been used for many years in electro-optical displays (liquid crystal displays: LCDs) to display information by amplitude modulating polarized light in the visible range. 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 (Non-Patent Document 1) 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. SPIE 7618, Emerging Liquid Crystal Technologies V, No. 76180E (February 12, 2010); doi:10.1117 / 12.851788, describes refractive beam steering using waveguide structures.

[0003] In the communications field, there is a growing need for optical components operating in the infrared region. For example, wavelength-selective switch (WSS)-based reconfigurable optical add-drop multiplexers (ROADMs) are essential components of dynamic optical networks. The rapid growth of high-speed broadband communications necessitates the development of so-called colorless, directionless, contentionless, and gridless (CDC-F) network architectures. Wavelength-selective switch technology, on which the latest generation of ROADMs are based, is envisioned to provide the CDC-F functionality upon which next-generation optical networks rely. Currently, there are several competing switch engine technologies for use in WSSs, one of which is the liquid-crystal-on-silicon (LCoS) spatial light modulator (SLM). LCoS-SLMs have demonstrated advantages such as flexible bandwidth adjustment, adaptive optical alignment for high-port-count WSSs, and robustness without mechanical movement.

[0004] Another application using liquid crystal-based devices is Lidar (light detection and ranging), a method of measuring distance by shining a laser beam at 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 3D representation of the target. WO 2019 / 24052 (Patent Document 1) proposes, for example, a holographic Lidar system using an LCoS SLM.

[0005] U.S. Patent No. 10,665,953 (Patent Document 2) proposes a tunable optical metasurface that includes an optically reflective surface that reflects infrared laser light, an optically resonant antenna array arranged on the reflective surface to achieve one-dimensional beam steering or shaping of a LIDAR system, and a voltage-controlled liquid crystal arranged in the optical field region of each optically resonant antenna.

[0006] The most important feature of phase-only LCoS devices is the use of optically nonlinear liquid crystal (LC) materials that are sensitive to operating temperature. While conventional LCoS devices mainly focus on light intensity modulation, which is insensitive to temperature changes, in phase-only LCoS devices, the optical phase modulation of incident light is the essential performance parameter, which can be easily affected by small changes in operating temperature, resulting in significant changes in the corresponding light diffraction output.

[0007] Liquid crystal mixtures optimized for typical display applications, such as televisions or mobile phones, known from the prior art are not suitable for infrared applications because their birefringence decreases with increasing wavelength, requiring optical devices with very high cell gaps to modulate IR radiation. Many liquid crystal mixtures suffer from both insufficient birefringence (Δn) and high optical losses in the IR region. The paper by Fenglin Peng, Yuan Chen, Shin-Tson Wu, Suvagata Tripathi, and Robert J. Twieg (2014) "Low-loss liquid crystals for infrared applications," Liquid Crystals, Vol. 41, No. 11, pp. 1545-1552; DOI: 10.1080 / 02678292.2014.932452 (Non-Patent Document 3) suggests avoiding liquid crystal mixture components with CN or NCS polar groups and using chlorine or fluorine instead. This problem is particularly acute in devices where phase modulation must be achieved at NIR wavelengths. A mixture optimized for birefringence alone is not sufficient for commercial applications; other thermal, optical, and electro-optical properties are also important. Outdoor IR applications of liquid crystal attenuators typically require a wide temperature range and low temperature dependence of the optical properties.

[0008] A key challenge for the development of next-generation LCoS devices is the creation of high-speed multilevel phase modulation. While nematic LCoS devices offer the advantages of multilevel phase modulation, they are limited by the slow response time of nematic liquid crystals. This is especially true for communications applications that use infrared wavelengths, which require thicker devices, thus resulting in even slower response times. Therefore, a major materials challenge for these applications is to find suitable high-speed LC materials that can achieve the full 2π phase depth required for these applications. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2019 / 24052 [Patent Document 2] Specification of U.S. Patent No. 10,665,953 [Non-Patent Document]

[0010] [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: pp. 268 - 298; doi: 10.1109 / 5.4872231<000111>[Non-Patent Document 2] Scott R. Davis, George Farca, Scott D. Rommel, Seth Johnson, Michael H. Anderson, "Liquid crystal waveguides: new devices enabled by >1000 waves of optical phase control", Proc. SPIE 7618, Emerging Liquid Crystal Technologies V, No. 76180E (February 12, 2010); doi: 10.1117 / 12.851788 [Non-Patent Document 3] Fenglin Peng, Yuan Chen, Shin-Tson Wu, Suvagata Tripathi and Robert J. Twieg (2014) Low loss liquid crystals for infrared applications, Liquid Crystals, Vol. 41: No. 11, pp. 1545 - 1552; DOI: 10.1080 / 02678292.2014.932452 [Disclosure of the Invention] [Problems to be Solved by the Invention]

[0011] There is a need for liquid crystal based optical components that have high birefringence, fast switching speeds, and overall improved properties relevant to applications, and that are operable in the infrared region of the electromagnetic spectrum.

[0012] The present invention has been devised in light of the problems in the prior art described herein, and 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]

[0013] The object of the present invention is an optical component comprising a liquid-crystalline medium sandwiched between a pair of substrates, wherein the liquid-crystalline medium comprises one or more compounds of formulae I, II and III.

[0014] [ka]

[0015] During the ceremony, R 1 represents H, linear or branched alkyl having 1 to 12, preferably 2 to 7, C atoms or alkenyl having 2 to 15, preferably 2 to 7, C atoms, in which one or more CH groups are [ka] may be replaced by Preferably it is alkyl or alkenyl, n is 0, 1 or 2; [ka] occur independently of each other, [ka] represents R in the formula Lare, identically or differently, at each occurrence, H or alkyl having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H, however, [ka] is substituted, [ka] Preferably, [ka] represents When n=2, [ka] One of the following is preferably [ka] represents Others are preferably [ka] represents Preferably [ka] are independent of each other, [ka] represents More preferably [ka] represents [ka] represents [ka] represents

[0016] R 2 represents H, linear or branched alkyl having 1 to 12, preferably 2 to 7, C atoms or alkenyl having 2 to 15, preferably 2 to 7, C atoms, in which one or more CH groups are [ka] may be replaced by Preferably it is alkyl or alkenyl, Z 21 represents trans -CH=CH-, trans -CF=CF- or -C≡C-, preferably -C≡C-, [ka] are independent of each other, [ka] represents R in the formula L are, identically or differently, at each occurrence, H or alkyl having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H, However, preferably, [ka] are independent of each other, [ka] represents [ka] is preferably [ka] represents [ka] is preferably [ka] More preferably, [ka] represents

[0017] R 3 represents H, linear or branched alkyl having 1 to 12, preferably 2 to 7, C atoms or alkenyl having 2 to 15, preferably 2 to 7, C atoms, in which one or more CH groups are [ka] may be replaced by Preferably it is alkyl or alkenyl, Z 31 and Z 32 On the other hand, preferably Z 32 represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and independently the other represents -C≡C-, trans-CH=CH-, trans-CF=CF- or a single bond, preferably one of them, preferably Z 32 represents -C≡C- or trans-CH=CH-, and the other represents a single bond; [ka] are independent of each other, [ka] represents R in the formula L are, identically or differently, at each occurrence, H or alkyl having 1 to 6 C atoms, preferably H, methyl or ethyl, particularly preferably H, however, [ka] is substituted, [ka] represents Preferably [ka] are independent of each other, [ka] represents More preferably [ka] represents [ka] represents [ka] represents However, compounds of the following formula RO are excluded from the compounds of formulas I, II and III.

[0018] In the compounds of formula I, II and III, R L preferably denotes H. In another preferred embodiment, in compounds of formula I, II and III, one or two groups R L , preferably one group R L is different from H.

[0019] The invention further relates to the use of the media defined above and below for phase modulation of said infrared light in the infrared region of the electromagnetic spectrum, preferably in the A-band and / or B-band and / or C-band.

[0020] The present invention further relates to a device comprising an optical component according to the invention, preferred devices being infrared imagers, wavelength-selective switches, LCoS-SLMs, LIDAR systems, wavelength-division multiplexing (WDM) systems, reconfigurable optical add-drop multiplexers (ROADMs), and steerable electro-evanescent optical refraction (SEEOR) prisms, as described in the article by P. McManamon, 2006, "Agile Nonmechanical Beam Steering", Opt. Photon. News, Vol. 17 (No. 3): pp. 24-29.

[0021] According to another aspect of the present invention, there is provided a method for spatially modulating infrared light, comprising the steps of: 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, wherein the liquid crystal comprises one or more compounds selected from compounds of formulas I, II and III 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 which includes:

[0022] 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 actuatable 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

[0023] 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 therein. As a result, the components and devices containing them can operate under extreme temperature conditions. Surprisingly, the temperature dependence of the birefringence of the liquid-crystalline medium is very small, i.e., Δn changes very little with temperature, making the devices reliable and easy to control.

[0024] The media used in the components according to the invention are distinguished by high values ​​of dielectric anisotropy and low rotational viscosity. As a result, the threshold voltage, i.e., the minimum voltage at which the device can switch, is very low. Low operating voltages and low threshold voltages are desirable to enable devices with improved switching characteristics and high energy efficiency. Low rotational viscosity allows the components and devices according to the invention to switch quickly. [Brief explanation of the drawings]

[0025] [Figure 1] 1 illustrates an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] 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.

[0027] As used herein, infrared A (IR-A) shall mean the spectral region of electromagnetic radiation having wavelengths within the range of 0.75 μm to 1.4 μm.

[0028] As used herein, infrared B (IR-B) shall mean the spectral region of electromagnetic radiation having wavelengths within the range of 1.4 μm to 3 μm.

[0029] As used herein, infrared-C (IR-C) shall mean the spectral region of electromagnetic radiation having wavelengths within the range of 3 μm to 1000 μm.

[0030] Preferably, the optical component according to the invention operates at wavelengths in the range of 750 nm to 2500 nm, in particular 1530 nm to 1565 nm.

[0031] 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.

[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] As used herein, a cyclic alkyl group refers to an alicyclic group or an alkyl group in which a methylene group has been replaced with an alicyclic group (i.e., cycloalkylalkyl or alkylcycloalkylalkyl), and the group may be saturated or partially unsaturated, and is preferably cyclopropyl, methylcyclopropyl, cyclobutyl, methylcyclobutyl, cyclopentyl, methylcyclopentyl, cyclopent-1-enyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, or cyclopent-1-enylmethyl.

[0036] In this specification, an alkoxy group is linear or branched and contains 1 to 15 C atoms, which is preferably linear and, unless otherwise stated, 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 this specification, the alkenyl group is preferably an alkenyl group having 2 to 15 carbon atoms, which is linear or branched and contains at least one C-C double bond. It is preferably linear and has 2 to 7 carbon atoms. Thus, 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, or hept-1-, -2-, -3-, -4-, -5- or -6-enyl. If two carbon atoms of the C-C double bond are substituted, the alkenyl group may be in the form of an E and / or Z isomer (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 C-C triple bond. 1- and 2-propynyl and 1-, 2- and 3-butynyl are preferred.

[0039] R F represents a halogenated alkyl, alkoxy, alkenyl or alkenyloxy, it may be branched or unbranched. Preferably, it is unbranched and monofluorinated, polyfluorinated or perfluorinated, preferably perfluorinated, and has 1, 2, 3, 4, 5, 6 or 7 C atoms, and in the case of alkenyl, 2, 3, 4, 5, 6 or 7 C atoms.

[0040] R P is preferably CN, NCS, Cl, F, -(CH2) n -CH=CF2, -(CH2) n -CH=CHF, -(CH2) n -CH=Cl2, -C n F 2n+1 , -(CF2) n -CF2H, -(CH2) n -CF3, -(CH2) n -CHF2, -(CH2) n CH2F, -CH=CF2, -O(CH2) n -CH=CF2, -O(CH2) n CHCl2, -OC n F 2n+1 , -O(CF2) n -CF2H, -O(CH2) n CF3, -O(CH2) n -CHF2, -O(CF) n CH2F, -OCF=CF2, -SC n F 2n+1 , -S(CF) n -CF3, where n is an integer of 0 to 7.

[0041] Preferably the medium comprises one or more compounds of formula RO.

[0042] [ka]

[0043] During the ceremony, R RO represents a linear or branched alkyl having 1 to 12 C atoms or a linear or branched alkenyl having 2 to 12 C atoms, in each of which one or more CH2 groups are [ka] may be replaced by Z T1 , Z T2 are the same or different and represent -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -CF=CF-, -C≡C- or a single bond; X 1 , X 2 , X 3 and X 4 are the same or different and represent H, Cl, F or CH3, preferably H or F; t is 0 or 1, and [ka] represents a group selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N, and in which one or more H atoms may be replaced by L; b) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, furan-2,5-diyl, each of which may be mono- or polysubstituted by L; L, in each occurrence, is the same or different and represents F, Cl, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, which may in each case be fluorinated.

[0044] In a preferred embodiment, R in the formula R RO represents a straight-chain alkyl or alkenyl having up to 7 C atoms.

[0045] In another preferred embodiment, R in formula RO RO represents a branched alkyl or alkenyl group having up to 10 C atoms.

[0046] In yet another preferred embodiment, R in formula RO RO represents a cyclic alkyl having up to 10 C atoms.

[0047] Preferably, the compound of formula RO is selected from the group consisting of formulas RO-1 to RO-7.

[0048] [ka]

[0049] In the formula, X 1 and X 2 represents H, Cl, F or CH3, preferably H or F, [ka] has the meaning given above, preferably [ka] Very preferably [ka] represents R ROhas one of the meanings given above and preferably denotes methyl, ethyl, n-propyl, 2-propyl, n-butyl, 2-butyl, 2-methylpropyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclopent-1-enyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentyl, cyclopent-1-enylmethyl, in which one or more, but not all, H atoms may be replaced by F.

[0050] More preferred compounds of the formulae RO-1 to RO-7 are selected from the group consisting of the formulae RO-2, RO-3, RO-4 and RO-5, very preferred is RO-2; particularly preferred is the medium comprising one or more n-alkoxy derivatives of the formula RO-2 selected from the subformulae RO-2-1a to RO-2-1l and / or one or more branched alkoxy derivatives selected from the subformulae RO-2-2a to RO-2-2m and / or one or more cycloalkoxy derivatives of the formula RO-2 selected from the subformulae RO-2-3a to RO-2-3p.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] In a preferred embodiment of the present invention, the compound of formula I is selected from the group of compounds of formulae I-1 to I-5.

[0058] [ka]

[0059] During the ceremony, L 1 , L 2 and L 3 represents H or F at each occurrence, which may be the same or different, and the other groups have the respective meanings given above in formula I, Preferably R 1 represents alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0060] The medium preferably comprises one or more compounds of formula I-1, preferably selected from the group of compounds of formulae I-1a to I-1d, preferably compounds of formula I-1b.

[0061] [ka]

[0062] In the formula, R 1 has the meaning given above in formula I and preferably denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0063] The medium preferably comprises one or more compounds of formula I-2, preferably selected from the group of compounds of formulae I-2a to I-2e, preferably compounds of formula I-2c.

[0064] [ka]

[0065] In the formula, R 1 has the meaning given above in formula I and preferably denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0066] The medium preferably comprises one or more compounds of formula I-3, preferably selected from the group of compounds of formula I-3a to I-3d, preferably compounds of formula I-3b.

[0067] [ka]

[0068] In the formula, R 1 has the meaning given above in formula I and preferably denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0069] The medium preferably comprises one or more compounds of formula I-4, preferably selected from the group of compounds of formula I-4a to I-4e, preferably compounds of formula I-4b.

[0070] [ka]

[0071] In the formula, R 1 has the meaning given above in formula I and preferably denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0072] The medium preferably comprises one or more compounds of formula I-5, preferably selected from the group of compounds of formulae I-5a to I-5d, preferably compounds of formula I-5b.

[0073] [ka]

[0074] In the formula, R 1 has the meaning given above in formula I and preferably denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0075] The medium preferably 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-2

[0076] [ka]

[0077] in which the occurring radicals have the meanings given above in formula II, and Preferably R 2 represents H, alkyl or alkoxy having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms, and [ka] represents The other, independently, [ka] Preferably [ka] Most preferably [ka] represents and preferably R 2 is C n H 2n+1 or CH2=CH-(CH2) Z represents, and n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0078] The compound of formula II-1 is preferably selected from the group of compounds of formulae II-1a to II-1f:

[0079] [ka]

[0080] During the ceremony, R 2 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and n's are each independently an integer in the range of 0 to 15, preferably in the range of 1 to 7 and particularly preferably in the range of 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0081] The compound of formula II-2 is preferably selected from the group of compounds of formula II-2a and II-2b:

[0082] [ka]

[0083] During the ceremony, R 2 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0084] The compound of formula II-3 is preferably selected from the group of compounds of formulae II-3a to II-3d:

[0085] [ka]

[0086] During the ceremony, R 2 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0087] The compound of formula III is preferably selected from the group of compounds of formulae III-1 to III-6, more preferably from the group of compounds of formulae III-1, III-2, III-3 and III-4, particularly preferably from the group of compounds of formula III-1.

[0088] [ka]

[0089] During the ceremony, Z 31 and Z 32 are each independently trans-CH=CH- or trans-CF=CF-, or in formula III-6, Z 31 and Z 32 may represent -C≡C-, the other radical having the meaning given above in formula III, and preferably R 3 represents H, alkyl or alkoxy having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms, and [ka] Preferably [ka] represents On the other hand, independently of each other, [ka] Preferably [ka] More preferably [ka] represents However, or [ka] represents and preferably R 3 is C n H 2n+1 or CH2=CH-(CH2) Z represents n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0090] The compound of formula III-1 is preferably selected from the group of compounds of formulae III-1a to III-1l, more preferably from the group of compounds of formulae III-1a, III-1b, III-1h and III-1i, particularly preferably from the group of compounds of formulae III-1b and / or III-1h.

[0091] [ka]

[0092] [ka]

[0093] During the ceremony, R 3has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0094] The compounds of formula III-2 are preferably compounds of formulae III-2a to III-2l, very preferably III-2b and / or III-2j.

[0095] [ka]

[0096] [ka]

[0097] During the ceremony, R 3 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z or a cyclic alkyl having 3 to 10 carbon atoms, n represents an integer in the range of 0 to 15, preferably 1 to 7 and particularly preferably 1 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0098] Very preferably, the medium comprises one or more compounds of the formula III-2j selected from the following sub-formulae III-2j-1 to III-2j-15:

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] The compounds of formula III-5 are preferably selected from the compounds of formula III-5a:

[0103] [ka]

[0104] R 3 has the meaning indicated above in formula III-5, preferably C n H 2n+1 where n represents an integer in the range of 0 to 7, preferably 1 to 5.

[0105] The compound of formula III-6 is preferably selected from the compounds of formulae III-6a to III-6l:

[0106] [ka]

[0107] [ka]

[0108] In a preferred embodiment, the medium according to the invention comprises one or more compounds selected from the group of the compounds of the formulae IIA-1-1 to IIA-1-12, very preferably IIA-1-1 or IIA-1-2.

[0109] [ka]

[0110] [ka]

[0111] During the ceremony, R 1 represents alkyl or alkenyl having up to 7 C atoms, preferably ethyl, n-propyl, n-butyl or n-pentyl, n-hexyl, R L are identical or different in each occurrence alkyl or alkenyl having 1 to 5 C atoms or cycloalkyl or cycloalkenyl having 3 to 6 C atoms, respectively, preferably methyl, ethyl, n-propyl, n-butyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopent-1-enyl, very preferably ethyl, and compounds of formula II-1 are excluded.

[0112] Additionally, the liquid crystal medium according to the invention in certain embodiments, which may be the same as or different from the above preferred embodiments, preferably comprises one or more compounds of formula IV.

[0113] [ka]

[0114] During the ceremony, [ka] represents s is 0 or 1, preferably 1, and Preferably [ka] Particularly preferably [ka] represents L 4represents H or alkyl having 1 to 6 C atoms, cycloalkyl having 3 to 6 C atoms or cycloalkenyl having 4 to 6 C atoms, preferably CH3, C2H5, n-C3H7, i-C3H7, cyclopropyl, cyclobutyl, cyclohexyl, cyclopent-1-enyl or cyclohex-1-enyl, and particularly preferably CH3, C2H5, cyclopropyl or cyclobutyl, X 4 represents H, alkyl having 1 to 3 C atoms or halogen, preferably H, F or Cl, more preferably H or F, very particularly preferably F, R 41 ~R 44 represent independently of one another alkyl or alkoxy, each having 1 to 15 C atoms, alkenyl, alkenyloxy or alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and alternatively R 43 and R 44 one or both of may also represent H; Preferably R 41 and R 42 represent, independently of one another, alkyl or alkoxy, each having 1 to 7 C atoms, or alkenyl, alkenyloxy or alkoxyalkyl, each having 2 to 7 C atoms, Particularly preferably R 41 represents alkyl having 1 to 7 C atoms or alkenyl, alkenyloxy or alkoxyalkyl, respectively having 2 to 7 C atoms, and Particularly preferably R 42 represents alkyl or alkoxy, each having 1 to 7 C atoms, and Preferably R 43 and R 44denotes H, alkyl having 1 to 5 C atoms, cycloalkyl or cycloalkenyl having 3 to 7 C atoms, alkylcycloalkyl or cycloalkylalkyl having 4 to 12 C atoms, respectively, or alkylcycloalkylalkyl having 5 to 15 C atoms, particularly preferably cyclopropyl, cyclobutyl or cyclohexyl, and very particularly preferably R 43 and R 44 At least one of these represents n-alkyl, particularly preferably methyl, ethyl or n-propyl, and the other represents H or n-alkyl, particularly preferably H, methyl, ethyl or n-propyl.

[0115] In a preferred embodiment of the present application the liquid crystal medium additionally comprises one or more compounds selected from the group of compounds of the formulae V, VI, VII, VIII and IX.

[0116] [ka]

[0117] During the ceremony, L 51 is R 51 or X 51 represents L 52 is R 52 or X 52 represents R 51 and R 52 represent, independently of one another, H, alkyl or alkoxy having 1 to 12, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, X 51 and X 52represent, independently of one another, H, F, Cl, -CN, -NCS, -SF5, a fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or a fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, preferably a fluorinated alkoxy, a fluorinated alkenyloxy, F or Cl, and [ka] Preferably [ka]

[0118] L 61 is R 61 represents Z 61 and / or Z 62 represents trans-CH=CH- or trans-CF=CF-, and alternatively X 61 Also represents, L 62 is R 62 represents Z 61 and / or Z 62 represents trans-CH=CH- or trans-CF=CF-, and alternatively X 62 Also represents, R 61 and R 62 represent, independently of one another, H, alkyl or alkoxy having 1 to 12, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, X 61 and X 62 represent, independently of one another, F or Cl, —CN, —SF5, fluorinated alkyl or alkoxy having 1 to 7 C atoms or fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 C atoms, Z 61 and Z 62one of them represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and independently the other represents trans-CH=CH-, trans-CF=CF- or a single bond, preferably one of them represents -C≡C- or trans-CH=CH-, and the other represents a single bond; [ka] Preferably [ka] represents, and

[0119] x represents 0 or 1, L 71 is R 71 or X 71 represents L 72 is R 72 or X 72 represents R 71 and R 72 represent, independently of one another, H, alkyl or alkoxy having 1 to 12, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, X 71 and X 72 represent, independently of one another, H, F, Cl, -CN, -NCS, -SF5, a fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or a fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, preferably a fluorinated alkoxy, a fluorinated alkenyloxy, F or Cl, and Z 71 ~Z 73 are independently trans-CH=CH-, trans-CF=CF-, -C≡C- or a single bond, one of which preferably represents a single bond, particularly preferably all of which represent a single bond, [ka] Preferably [ka] represents

[0120] R 81 and R 82 represent, independently of one another, H, alkyl or alkoxy having 1 to 15, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, Z 81 and Z 82 one of them represents trans-CH=CH-, trans-CF=CF- or -C≡C-, and the others independently represent trans-CH=CH-, trans-CF=CF- or a single bond, one of them preferably represents -C≡C- or trans-CH=CH-, and the other represents a single bond; and [ka] [ka] represents

[0121] L 91 is R 91 or X 91 represents L 92 is R 92 or X 92 represents R 91 and R 92 represent, independently of one another, H, alkyl or alkoxy having 1 to 15, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, X 91 and X 92represent, independently of one another, H, F, Cl, -CN, -NCS, -SF5, a fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or a fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, preferably a fluorinated alkoxy, a fluorinated alkenyloxy, F or Cl, and Z 91 ~Z 93 are independently trans-CH=CH-, trans-CF=CF-, -C≡C- or a single bond, one of which preferably represents a single bond, particularly preferably all of which represent a single bond, [ka] [ka] Represents.

[0122] In a preferred embodiment of the invention the liquid crystal medium comprises one or more compounds selected from the group of compounds of formula V, preferably of formulae V-1 to V-3, preferably of formulae VI-1 and / or V-2 and / or V-3, preferably of formulae V-1 and V-2

[0123] [ka]

[0124] wherein the parameters each have the meanings given in Formula V above, preferably R 51 represents alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms, R 52 represents alkyl having 1 to 7 C atoms, alkenyl having 2 to 7 C atoms, or alkoxy having 1 to 7 C atoms, X 51 and X 52are each independently F, Cl, —OCF3, —CF3, —CN, —NCS or —SF5, preferably F, Cl, —OCF3 or —CN. The compounds of formula V-1 are preferably selected from the group of compounds of formulae V-1a to V-1d, preferably of formulae V-1c and V-1d:

[0125] [ka]

[0126] wherein the parameters each have the meanings given above in Formula V-1, except that Y 51 and Y 52 represent in each case independently of one another H or F, and preferably R 51 represents alkyl or alkenyl, and X 51 represents F, Cl or -OCF3. The compound of formula V-2 is preferably selected from the group of compounds of formulae V-2a to V-2e and / or from the group of compounds of formulae V-2f and V-2g.

[0127] [ka]

[0128] In each case, compounds of formula V-2a are excluded from compounds of formula V-2b and V-2c, compounds of formula V-2b are excluded from compounds of formula V-2c, compounds of formula V-2f are excluded from compounds of formula V-2g, and wherein the parameters each have the meanings set forth above in Equation V-1, Y 51 and Y 52 represent in each case independently of one another H or F, and preferably Y 51 and Y 52 denote in each case independently of one another H or F, preferably H as well.

[0129] The compound of formula V-3 is preferably a compound of formula V-3a:

[0130] [ka]

[0131] wherein the parameters each have the meanings given in formula V-1 above, but preferably X 51 represents F, Cl, preferably F, X 52 represents F, Cl or —OCF3, preferably —OCF3.

[0132] The compound of formula V-1a is preferably selected from the group of compounds of formula V-1a-1 and V-1a-2:

[0133] [ka]

[0134] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 where n represents an integer in the range of 0 to 7, preferably 1 to 5, and particularly preferably 3 or 7.

[0135] The compound of formula V-1b is preferably a compound of formula V-1b-

[0136] [ka]

[0137] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 where n represents an integer in the range of 0 to 15, preferably 1 to 7, and particularly preferably 1 to 5.

[0138] The compound of formula V-1c is preferably selected from the group of compounds of formulae V-1c-1 to V-1c-4, particularly preferably selected from the group of compounds of formulae V-1c-1 and V-1c-2.

[0139] [ka]

[0140] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 where n represents an integer in the range of 0 to 15, preferably 1 to 7, and particularly preferably 1 to 5.

[0141] The compound of the formula V-1d is preferably selected from the group of the compounds of the formulae V-1d-1 and V-1d-2, particularly preferably the compound of the formula V-1d-2.

[0142] [ka]

[0143] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 where n represents an integer in the range of 1 to 7, preferably 2 to 6, and particularly preferably 2 to 5.

[0144] The compound of the formula V-2a is preferably selected from the group of the compounds of the formulae V-2a-1 and V-2a-2, particularly preferably the compound of the formula V-2a-1.

[0145] [ka]

[0146] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0147] In particular, in the case of formula V-2a-1 (R 51 and R 52 ) is preferably a combination of (C n H 2n+1 and C m H 2m+1 ), (C n H 2n+1 and O.C. m H 2m+1 ), (CH2=CH-(CH2) Z and C m H 2m+1 ), (CH2=CH-(CH2) Z and O.C. m H 2m+1 ) and (C n H 2n+1 and (CH2) Z -CH=CH2).

[0148] A preferred compound of formula V-2b is a compound of formula V-2b-1.

[0149] [ka]

[0150] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0151] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 )

[0152] A preferred compound of formula V-2c is a compound of formula V-2c-1:

[0153] [ka]

[0154] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0155] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 )

[0156] A preferred compound of formula V-2d is a compound of formula V-2d-1:

[0157] [ka]

[0158] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0159] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 )

[0160] A preferred compound of formula V-2e is a compound of formula V-2e-1.

[0161] [ka]

[0162] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0163] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and O.C. m H 2m+1 )

[0164] A preferred compound of formula V-2f is a compound of formula V-2f-1:

[0165] [ka]

[0166] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Zrepresents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0167] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0168] A preferred compound of formula V-2g is a compound of formula V-2g-1.

[0169] [ka]

[0170] During the ceremony, R 51 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 52 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0171] where (R 51 and R 52 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and O.C. m H 2m+1 )

[0172] The compound of formula VI is preferably selected from the group of compounds of formulae VI-1 to VI-5:

[0173] [ka]

[0174] During the ceremony, Z 61 and Z 62 represents -C≡C-, trans-CH=CH- or trans-CF=CF-, preferably -C≡C- or trans-CH=CH-, and other occurring groups and parameters have the meanings given in formula VI above, preferably R 61 and R 62 represent, independently of one another, alkyl or alkoxy having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms, X 62 represents F, Cl, -OCF3 or -CN.

[0175] The compound of formula VI-1 is preferably selected from the group of compounds of formula VI-1a and VI-1b, more preferably selected from the group of compounds of formula VI-1a.

[0176] [ka]

[0177] During the ceremony, R 61 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 62 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0178] In this specification, (R 61 and R 62 ) is particularly preferred combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), and in the case of formula U-1a, particularly preferably (C n H 2n+1 and C m H 2m+1 ), and in the case of formula U-1b, it is particularly preferably (C n H 2n+1 and O.C. m H 2m+1 )

[0179] The compound of formula VI-3 is preferably selected from the compounds of formulae VI-3a to VI-3e:

[0180] [ka]

[0181] wherein the parameters have the meanings given above in formula VI-3, preferably R 61 has the meaning given above, preferably C n H 2n+1 where n represents an integer ranging from 1 to 7, preferably from 2 to 5, and X 62 represents -F, -Cl, -OCF3 or -CN.

[0182] The compound of formula VI-4 is preferably selected from the compounds of formulae VI-4a to VI-4e:

[0183] [ka]

[0184] wherein the parameters have the meanings given above in formula VI-4, preferably R 61 has the meaning given above, preferably C n H 2n+1 where n represents an integer ranging from 1 to 7, preferably from 2 to 5, and X 62 represents -F, -Cl, -OCF3 or -CN.

[0185] The compounds of formula VI-5 are preferably selected from the compounds of formulae VI-5a to VI-5d, preferably VI-5b:

[0186] [ka]

[0187] wherein the parameters have the meanings given above in formula VI-5, preferably R 61 has the meaning given above, preferably C n H 2n+1 where n represents an integer ranging from 1 to 7, preferably from 2 to 5, and X 62 represents -F, -Cl, -OCF3 or -CN, particularly preferably -OCF3.

[0188] The compound of formula VII is preferably selected from the group of compounds of formulae VII-1 to VII-6:

[0189] [ka]

[0190] provided that compounds of formula VII-5 are excluded from compounds of formula VII-6, and wherein the parameters each have the meanings set forth above in Formula VII; Y 71 , Y 72 , Y 73 represent independently of one another H or F, and Preferably R 71 represents alkyl or alkoxy, each having 1 to 7 C atoms, or alkenyl having 2 to 7 C atoms, R 72 represents alkyl or alkoxy, each having 1 to 7 C atoms, or alkenyl having 2 to 7 C atoms, and X 72 represents F, Cl, NCS or -OCF3, preferably F or NCS, and Particularly preferably, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Zrepresents, and R 72 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0191] The compound of formula VII-1 is preferably selected from the group of compounds of formulae VII-1a to VII-1d:

[0192] [ka]

[0193] X in the formula 72 has the meaning given above in formula VII-2, and R 71 has the meaning given above, preferably C n H 2n+1 where n represents 1 to 7, preferably 2 to 6, particularly preferably 2, 3 or 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2, and X 72 preferably represents F.

[0194] The compounds of the formula VII-2 are preferably selected from the group of the compounds of the formulae VII-2a and VII-2b, particularly preferably of the formula VII-2a.

[0195] [ka]

[0196] During the ceremony, R 71has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 72 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0197] where (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0198] The compound of formula VII-3 is preferably a compound of formula VII-3a.

[0199] [ka]

[0200] During the ceremony, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 72 has the meaning given above, preferably C m H2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0201] where (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0202] The compound of formula VII-4 is preferably a compound of formula VII-4a:

[0203] [ka]

[0204] During the ceremony, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 72 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0205] where (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0206] The compound of formula VII-5 is preferably selected from the group of compounds of formula VII-5a and VII-5b, more preferably of formula VII-5a.

[0207] [ka]

[0208] During the ceremony, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 72 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0209] where (R 71 and R 72) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0210] The compound of formula VII-6 is preferably selected from the group of compounds of formula VII-6a and VII-6b:

[0211] [ka]

[0212] During the ceremony, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 72 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0213] where (R 71 and R 72 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0214] The compound of formula VII-7 is preferably selected from the group of compounds of formulae VII-7a to VII-7d:

[0215] [ka]

[0216] During the ceremony, R 71 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents X 72 represents F, -OCF3 or -NCS, n represents an integer in the range of 1 to 7, preferably 2 to 6 and particularly preferably 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0217] The compounds of formula VIII are preferably selected from the group of compounds of formulae VIII-1 to VIII-3, more preferably these compounds of formula VIII consist mainly, even more preferably consist essentially and very particularly preferably consist completely thereof.

[0218] [ka]

[0219] During the ceremony, Y 81 and Y 82 one of represents H and the other represents H or F, and R 81 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2)Z represents, and R 82 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0220] where (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0221] The compound of formula VIII-1 is preferably selected from the group of compounds of formulae VIII-1a to VIII-1c:

[0222] [ka]

[0223] During the ceremony, R 81 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 82 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0224] where (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0225] The compound of formula VIII-2 is preferably a compound of formula VIII-2a.

[0226] [ka]

[0227] During the ceremony, R 81 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 82 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0228] where (R 81 and R 82 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ), (C n H 2n+1 and O.C. m H 2m+1 ) and (CH2=CH-(CH2) Z and C m H 2m+1 ), particularly preferably (C n H 2n+1 and C m H 2m+1 )

[0229] The compound of formula VIII-3 is preferably a compound of formula VIII-3a.

[0230] [ka]

[0231] During the ceremony, R 81 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 82 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0232] where (R 81 and R 82) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 )

[0233] The compound of formula IX is preferably selected from the group of compounds of formulae IX-1 to IX-3:

[0234] [ka]

[0235] wherein the parameters each have the meanings given in formula IX above, preferably [ka] and wherein R 91 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 92 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0236] where (R 91 and R 92 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1and O.C. m H 2m+1 )

[0237] The compound of formula IX-1 is preferably selected from the group of compounds of formulae IX-1a to IX-1e:

[0238] [ka]

[0239] wherein the parameters have the meanings given above, preferably R 91 has the meaning given above, preferably C n H 2n+1 represents, and n represents an integer in the range of 1 to 7, preferably 2 to 6 and particularly preferably 2 to 5, and X 92 preferably represents F or Cl.

[0240] The compound of formula IX-2 is preferably selected from the group of compounds of formulae IX-2a and IX-2b:

[0241] [ka]

[0242] During the ceremony, R 91 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 92 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0243] where (R 91 and R 92 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 )

[0244] The compound of formula IX-3 is preferably selected from the group of compounds of formulae IX-3a and IX-3b:

[0245] [ka]

[0246] During the ceremony, R 91 has the meaning given above, preferably C n H 2n+1 or CH2=CH-(CH2) Z represents, and R 92 has the meaning given above, preferably C m H 2m+1 or O.C. m H 2m+1 or (CH2) Z represents -CH=CH2, n and m each independently represent an integer in the range of 1 to 7, preferably in the range of 2 to 6 and particularly preferably in the range of 2 to 5, and z represents 0, 1, 2, 3 or 4, preferably 0 or 2.

[0247] where (R 91 and R 92 ) is particularly preferably a combination of (C n H 2n+1 and C m H 2m+1 ) and (C n H 2n+1 and O.C. m H 2m+1 ), particularly preferably (Cn H 2n+1 and O.C. m H 2m+1 )

[0248] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula X:

[0249] [ka]

[0250] During the ceremony, R 101 represents H, alkyl or alkoxy having 1 to 15, preferably 2 to 7, C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15, preferably 2 to 7, C atoms, preferably alkyl or alkenyl, X 101 represents H, F, Cl, —CN, SF5, NCS, a fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or a fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, preferably a fluorinated alkoxy, fluorinated alkenyloxy, F, Cl or NCS, particularly preferably NCS, Y 101 represents methyl, ethyl or Cl, Y 102 represents H, methyl, ethyl, F or Cl, preferably H or F, Z 101 , Z 102 are the same or different and represent a single bond, -CH=CH-, -CF=CF- or -C≡C-; [ka] Preferably [ka] represents, and, however, or [ka] represents n is 0 or 1.

[0251] Preferably, the compound of formula X is selected from sub-formulae X-1 and X-2.

[0252] [ka]

[0253] wherein the occurring groups and parameters have the meanings given above for formula X.

[0254] Particularly preferably, the medium according to the invention comprises one or more compounds selected from the group of compounds of the formulae X-1-1 to X-1-9.

[0255] [ka]

[0256] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula XI.

[0257] [ka]

[0258] During the ceremony, R S represents 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 CH2 groups are [ka] wherein one or more H atoms may be replaced by F; [ka] represents In the formula, R L are identical or different at each occurrence and represent H, Cl or a linear, branched or cyclic alkyl having 1 to 6 C atoms, L S1 , L S2 are the same or different and represent H, Cl or F; R S1 , R S2 are the same or different and represent H, alkyl or alkenyl having up to 6 C atoms or cyclopropyl, cyclobutyl, cyclopentenyl or cyclopentyl, R Th1 , R Th2 are the same or different and represent H, alkyl or alkenyl or alkoxy having up to 6 C atoms or cyclopropyl, cyclobutyl, cyclopentenyl or cyclopentyl, Z S1 , Z S2 , Z S3 are the same or different and represent -CH=CH-, -CH=CF-, -CF=CH-, -CF=CF-, -C≡C- or a single bond; a and b are the same or different and each is 0 or 1.

[0259] Preferably, the compound of formula XI is selected from the group of compounds of formula XI-1 to formula XI-24.

[0260] [ka]

[0261] [ka]

[0262] [ka]

[0263] [ka]

[0264] in which the occurring radicals have the meanings given above for formula XI, preferably R S represents an alkyl or alkenyl having 2 to 6 C atoms, in which one or more CH2 groups are [ka] may be replaced by R S1 and R S2 are the same or different and represent H or alkyl having 1 to 6 C atoms, preferably H, R S3 represents H, F or alkyl having up to 6 C atoms or cyclopropyl, preferably H, F or ethyl, very preferably H, L S1 and L S2 are the same or different and represent H or F, preferably F.

[0265] Preferably, the medium according to the invention comprises one or more compounds of formula T

[0266] [ka]

[0267] During the ceremony, R T is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or alkenyl having up to 12 C atoms, [ka] represents L 4 and L 5are the same or different and represent F, Cl or straight-chain, branched or cyclic alkyl or alkenyl having up to 12 C atoms, Z T3 , Z T4 are the same or different and represent -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, and t is 0 or 1.

[0268] In a preferred embodiment, the liquid crystal medium according to the invention comprises one or more compounds selected from the group of compounds of the following formulae T-1a to T-3b:

[0269] [ka]

[0270] During the ceremony, [ka] has the meaning given above, and n is 1, 2, 3, 4, 5, 6 or 7, preferably 1, 2, 3 or 4, particularly preferably 1.

[0271] In a particularly preferred embodiment of the invention, the medium comprises one or more compounds selected from the compounds of formula T-1a and formula T-2a:

[0272] Preferred compounds of formula T-1a are selected from the group of compounds of the following subformulae:

[0273] [ka]

[0274] In the formula, n is 1, 2, 3 or 4, preferably 1.

[0275] Preferred compounds of formula T-2a are selected from the group of compounds of the following subformulae:

[0276] [ka]

[0277] In the formula, n is 1, 2, 3 or 4, preferably 1.

[0278] Highly preferably, the medium comprises one or more compounds of formula T-1a-5.

[0279] Preferably, the medium comprises a compound of formula C.

[0280] [ka]

[0281] During the ceremony, R C represents 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 CH2 groups are [ka] or the group R P represents R P is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or alkenyl having up to 9 C atoms, Z C1 , Z C2 are the same or different and represent -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -C≡C- or a single bond; X represents Cl or F, preferably F, Y represents H, Cl, F, alkyl or alkoxy, each having 1 to 6 C atoms, preferably H, F, CH3 or C2H5, very preferably H, t is 0, 1 or 2, preferably 0 or 1, and [ka] represents a group selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N, and in which one or more H atoms may be replaced by L; b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, in which one or more non-adjacent CH groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by F; c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may be mono- or polysubstituted by L; L, in each occurrence, is the same or different and represents F, Cl, CN, SCN, SF5, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, or alkoxycarbonyloxy having 1 to 12 C atoms, which may in each case be fluorinated.

[0282] Compounds of formula C are preferably selected from compounds of the following sub-formulae:

[0283] [ka]

[0284] [ka]

[0285] During the ceremony, L 1 , L 2 and L 3 are the same or different and represent H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, or cyclopentenyl; R C and X has the meaning given above, preferably R C is an alkyl having 1 to 7 C atoms or a group R P represents However, R P preferably denotes perfluoroalkoxy having 1 to 7 C atoms, X represents F.

[0286] Preferably, the group Z of formula C C1 and Z C2 One of the groups represents a single bond, and Z C1 and Z C2 The other represents -C≡C-. Highly preferred compounds of formula C are selected from compounds of the following sub-formulae:

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] In the formula, R C has the meaning given above and preferably denotes alkyl having 1 to 7 C atoms or CF3O.

[0291] Very particularly preferred compounds are those of the formulae C-7-1, C-9-1, C-9-4, C-10-1, C-10-2, C-10-3, C-10-4, C-10-5, C-10-6 and C-10-7.

[0292] Preferably, the medium comprises one or more compounds of formula U:

[0293] Compound of formula U

[0294] [ka]

[0295] During the ceremony, R U represents 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 CH2 groups are [ka] or the group R P where R P is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or alkenyl having up to 9 C atoms, Z U1 , Z U2 , Z U3 are the same or different and represent -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -C≡C- or a single bond; X 1 , X 2 are the same or different and represent H, Cl, F, CH or CH, preferably F; Y 1 , Y 2 , Y3 , Y 4 are the same or different and represent H, F, Cl or a linear, branched or cyclic alkyl, alkenyl, alkoxy or alkenyloxy, each having up to 12 C atoms, provided that Y 1 , Y 2 , Y 3 and Y 4 At least one of is different from F, s is 0, 1 or 2, preferably 0 or 1; t is 0, 1 or 2, preferably 0 or 1; s+t is 0, 1 or 2, preferably 0 or 1; [ka] represents a group selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N, and in which one or more H atoms may be replaced by L; b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, in which one or more non-adjacent CH groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by F; c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may be mono- or polysubstituted by L; L, in each occurrence, is the same or different and represents F, Cl, CN, SCN, SF5, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, or alkoxycarbonyloxy having 1 to 12 C atoms, which may in each case be fluorinated.

[0296] Compounds of formula U are preferably selected from compounds of the following sub-formulae:

[0297] In a preferred embodiment of the invention, the compound of formula U is selected from the compounds of formulae U-1 to U-20, very preferably from the compounds of formulae U-1 to U-13.

[0298] [ka]

[0299] [ka]

[0300] [ka]

[0301] [ka]

[0302] in which the occurring radicals have the meanings given above for formula U and its subformulas, preferably R U represents alkyl having 1 to 7 carbon atoms, Y 1 , Y 2 , Y 3 and Y 4 are the same or different and represent H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, more preferably Y 1 and Y 2 independently represent H or F, in particular H; Y 3 and Y 4 very preferably denotes H, L 1 and L 2 are identical or different and very preferably represent H, F, methyl or ethyl, in particular H.

[0303] According to one embodiment of the present invention, R U represents 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 CH2 groups are [ka] may be replaced by Preferably compounds of formula U are used, which are alkyl with 1 to 12 C atoms.

[0304] According to another embodiment of the present invention, the group R U R P where R P is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F Compounds of formula U are used, where U represents a fluorinated alkyl or fluorinated alkenyl having up to 9 C atoms, preferably CF3 or OCF3.

[0305] Preferably, the medium comprises one or more compounds of formula UF.

[0306] The present invention relates to compounds of formula U:

[0307] [ka]

[0308] During the ceremony, R T represents 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 CH2 groups are [ka] or the group R P represents RP is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F represents a fluorinated alkyl or alkenyl having up to 9 C atoms, Z T1 , Z T2 are the same or different and represent -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C- or a single bond, preferably -C≡C- or a single bond; X 1 , X 2 , X 3 and X 4 are the same or different and represent Cl or F, preferably F; t is 0 or 1, and [ka] represents a group selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by L, with the exception of tetrafluoro-1,4-phenylene; b) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene, bicyclo[1.1.1]pentane-1,3-diyl, 4,4'-bicyclohexylene, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, in which one or more non-adjacent CH groups may be replaced by -O- and / or -S-, and in which one or more H atoms may be replaced by F; c) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, each of which may be mono- or polysubstituted by L; L, in each occurrence, is the same or different and represents F, Cl, CN, SCN, SF5, or a linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, or alkoxycarbonyloxy having 1 to 12 C atoms, which may in each case be fluorinated.

[0309] The compounds of formula UF are preferably selected from the compounds of the following sub-formulae:

[0310] [ka]

[0311] [ka]

[0312] During the ceremony, L 1 , L 2 and L 3 are the same or different and represent H, F, Cl, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyclobutyl, cyclopentyl, or cyclopentenyl; R T , X 1 , X 2 , X 3 and X 4 has the meaning given above.

[0313] According to one embodiment of the present invention, R U represents 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 CH2 groups are [ka] may be replaced by Preferably compounds of formula UF are used, which are alkyl having 1 to 12 C atoms.

[0314] According to another embodiment of the present invention, the group R U R P where R P is halogen, CN, NCS, R F , R F -O- or R F -S-, where R F Compounds of the formula UF are used, where UF stands for fluorinated alkyl or fluorinated alkenyl having up to 9 C atoms, preferably CF3 or OCF3.

[0315] The medium according to the invention comprises one or more chiral dopants. Preferably, these chiral dopants are -1 ~150μm -1 in the range of 10 μm -1 ~100μm -1 The absolute value of the helical twisting power (HTP) is in the range of . If the medium contains two or more chiral dopants, they may have opposite signs of their HTP values. This condition is preferred for some specific embodiments, since it allows the chirality of each compound to be compensated to some extent, and can thus be used to compensate for the various temperature-dependent properties of the resulting medium in the device. However, it is generally preferred that most, preferably all, of the chiral compounds present in the medium according to the present invention have the same sign of their HTP values.

[0316] Preferably, the chiral dopants present in the media according to the present application are mesogenic compounds, most preferably they alone exhibit a mesophase.

[0317] In a preferred embodiment of the present invention, the medium comprises two or more chiral compounds that all have the same algebraic sign of the HTP.

[0318] The temperature dependence of the HTP of individual compounds can be high or low. The temperature dependence of the pitch of the medium can be compensated for by mixing compounds with different temperature dependences of the HTP in corresponding ratios.

[0319] For optically active components, a large number of chiral dopants, some of which are commercially available, are available to those skilled in the art, such as, for example, cholesteryl nonanoate, R- and S-811, R- and S-1011, R- and S-2011, R- and S-3011, R- and S-4011, or CB15 (all Merck, Darmstadt).

[0320] Particularly suitable dopants are compounds which contain one or more chiral groups and one or more mesogenic groups, or one or more aromatic or alicyclic groups which together with the chiral groups form a mesogenic group.

[0321] Suitable chiral groups are, for example, monovalent or polyvalent chiral groups selected from the group consisting of chiral branched hydrocarbon groups, chiral ethanediols, binaphthols or dioxolanes, also sugar derivatives, sugar alcohols, sugar acids, lactic acid, chiral substituted glycols, steroid derivatives, terpene derivatives, amino acids or sequences of several, preferably 1 to 5, amino acids.

[0322] Preferred chiral groups are sugar derivatives, such as glucose, mannose, galactose, fructose, arabinose and dextrose; sugar alcohols, such as sorbitol, mannitol, iditol, galactitol or their anhydro derivatives, in particular dianhydrohexitols, such as dianhydrosorbide (1,4:3,6-dianhydro-D-sorbide, isosorbide), dianhydromannitol (isosorbitol) or dianhydroiditol (isoiditol); sugar acids, such as gluconic acid, gulonic acid and ketogulonic acid; chiral substituted glycol groups. , such as mono- or oligoethylene or propylene glycols in which one or more CH2 groups are substituted by alkyl or alkoxy; amino acids, such as alanine, valine, phenylglycine or phenylalanine, or a sequence of 1 to 5 of these amino acids; steroid derivatives, such as cholesteryl or cholic acid groups; terpene derivatives, such as menthyl, neomenthyl, campheyl, pineyleyl, terpineyl, isolongifolyl, fenchyl, careyl, myrtenyl, nopyr, geranyl, linaloyl, neryl, citronellyl or dihydrocitronellyl.

[0323] The medium according to the present invention preferably comprises chiral dopant that is selected from the group of known chiral dopants.Suitable chiral group and mesogenic chiral compound are described, for example, in German Patent No. 3425503, German Patent No. 3534777, German Patent No. 3534778, German Patent No. 3534779 and German Patent No. 3534780, German Patent No. 4342280, European Patent No. 01038941 and German Patent No. 19541820.Also examples are the compounds listed in table F below.

[0324] Chiral compounds preferably used in accordance with the present invention are selected from the group consisting of the formulae shown below:

[0325] Particularly preferred are chiral dopants selected from the group consisting of compounds of the following formulae AI to A-III and A-Ch:

[0326] [ka]

[0327] During the ceremony, R a11 , R a12 and R b12 represent, independently of one another, alkyl having 1 to 15 C atoms, where, furthermore, one or more non-adjacent CH groups may be, independently of one another, —C(R z )=C(R z )-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, wherein further one or more H atoms may be replaced by F, Cl, Br, I or CN; Preferably, it represents alkyl, more preferably n-alkyl, provided that R a12 is R b12 Unlike, R a21 and R a22 represent, independently of one another, alkyl having 1 to 15 C atoms, where, furthermore, one or more non-adjacent CH groups may be, independently of one another, —C(R z )=C(R z )-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, wherein further one or more H atoms may be replaced by F, Cl, Br, I or CN; Preferably, both represent alkyl, more preferably n-alkyl; R a31 , R a32 and R b32 represent, independently of one another, a straight-chain or branched alkyl having 1 to 15 C atoms, wherein further, one or more non-adjacent CH groups may be joined independently of one another by a -C(R z )=C(R z)-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, wherein further one or more H atoms may be replaced by F, Cl, Br, I or CN; Preferably, it represents alkyl, more preferably n-alkyl, provided that R a32 is R b32 Unlike, R z represents H, CH3, F, Cl or CN, preferably H or F, R 8 is the R given above a11 preferably alkyl having 1 to 15 C atoms, more preferably n-alkyl, Z 8 represents —C(O)O—, —CHO—, —CFO— or a single bond, preferably —C(O)O—, A 11 is below A 12 or [ka] represents A 12 teeth, [ka] Preferably [ka] represents During the ceremony, L 12 represent, in each occurrence independently of one another, halogen, CN, or alkyl, alkenyl, alkoxy or alkenyloxy having up to 12 C atoms, with the proviso that one or more H atoms may be replaced by halogen, preferably methyl, ethyl, Cl or F, particularly preferably F. A 21 teeth, [ka] represents A 22 is A 12 has the meaning given to A 31 is A 11 has the meaning given to [ka] represents A 32 is A 12 has the meaning given to n2 is, identically or differently, 0, 1, or 2 in each occurrence; n3 is 1, 2 or 3; r is 0, 1, 2, 3 or 4.

[0328] Particularly preferred are dopants selected from the group consisting of compounds of the following formulae:

[0329] [ka]

[0330] [ka]

[0331] During the ceremony, m, which may be the same or different in each occurrence, is an integer from 1 to 9; and n is the same or different in each occurrence and is an integer from 2 to 9.

[0332] A particularly preferred compound of formula A is the compound of formula A-III:

[0333] Further preferred dopants are derivatives of isosorbide, isomannitol or isoiditol of formula A-IV below.

[0334] [ka]

[0335] In the formula, the group [ka] teeth, [ka] and preferably dianhydrosorbitol.

[0336] and chiral ethanediols, such as diphenylethanediol (hydrobenzoin), in particular mesogenic hydrobenzoin derivatives of formula AV below, including the (S,S) enantiomer not shown.

[0337] [ka]

[0338] During the ceremony, [ka] 1,4-phenylene or 1,4-cyclohexylene, each of which may be mono-, di- or trisubstituted by L; L is H, F, Cl, CN, or optionally halogenated alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, or alkoxycarbonyloxy having 1 to 7 carbon atoms; c is 0 or 1, X is CH2 or -C(O)-; Z 0 is -COO-, -OCO-, -CH2CH2- or a single bond, R 0 is alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having 1 to 12 carbon atoms.

[0339] Examples of compounds of formula IV are:

[0340] [ka]

[0341] [ka]

[0342] Compounds of formula A-IV are described in WO 98 / 00428. Compounds of formula AV are described in GB 2,328,207.

[0343] Highly particularly preferred dopants are the chiral binaphthyl derivatives described in WO 02 / 94805, the chiral binaphthol acetal derivatives described in WO 02 / 34739, the chiral TADDOL derivatives described in WO 02 / 06265, and the chiral dopants having at least one fluorinated bridging group and a terminal or central chiral group described in WO 02 / 06196 and WO 02 / 06195.

[0344] Chiral compounds of formula A-VI are particularly preferred.

[0345] [ka]

[0346] During the ceremony, X 1 , X 2 , Y 1 and Y 2 are each, independently of one another, F, Cl, Br, I, CN, SCN, SF, linear or branched alkyl having 1 to 25 carbon atoms (which may be mono- or polysubstituted with F, Cl, Br, I or CN, and in addition, one or more non-adjacent CH groups are each, independently of one another, -O-, -S-, -NH-, NR, such that O and / or S atoms are not directly bonded to one another; 0-, -CO-, -COO-, -OCO-, -OCOO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C-), a polymerizable group or a cycloalkyl or aryl having up to 20 carbon atoms, which may be optionally mono- or polysubstituted by halogen, preferably F, or by a polymerizable group, x 1 and x 2 are each independently 0, 1 or 2, y 1 and y 2 are each independently 0, 1, 2, 3 or 4, B 1 and B 2 are each, independently of one another, an aromatic or partially saturated or fully saturated aliphatic six-membered ring, in which one or more CH groups are each optionally replaced by an N atom, and one or more non-adjacent CH groups are each optionally replaced by O and / or S, W 1 and W 2 are each independently of the other, -Z 1 -A 1 -(Z 2 -A 2 ) m -R, or one of the two is R 1 or A 3 but not both at the same time, or [ka] teeth, [ka] and U 1 and U 2 are each independently CH, O, S, CO or CS, V 1 and V 2 are each independently (CH2) n(wherein 1 to 4 non-adjacent CH groups may be replaced by O and / or S), and V 1 and V 2 One of them is [ka] but, [ka] are both single bonds, n is 1, 2 or 3; Z 1 and Z 2 are each independently -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, or -CO-NR 0 -, -NR 0 -CO-, -O-CH2-, -CH2-O-, -S-CH2-, -CH2-S-, -CF2-O-, -O-CF2-, -CF2-S-, -S-CF2-, -CH2-CH2-, -CF2-CH2-, -CH2-CF2-, -CF2-CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C-, a combination of two of these groups (wherein two O and / or S and / or N atoms are not directly bonded to each other), (preferably -CH=CH-COO- or -COO-CH=CH-), or a single bond, R x represents alkyl having 1 to 6 C atoms, A 1 , A 2 and A 3are each independently 1,4-phenylene in which one or two non-adjacent CH groups may be replaced by N, 1,4-cyclohexylene in which one or two non-adjacent CH groups may be replaced by O and / or S, 1,3-dioxolane-4,5-diyl, 1,4-cyclohexenylene, 1,4-bicyclo[2.2.2]octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl (each of these groups may be mono- or polysubstituted by L), and further A 1 can be a single bond, L is a halogen atom, preferably F, CN, NO, alkyl having 1 to 7 carbon atoms, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy (wherein one or more H atoms may be replaced by F or Cl), m is independently 0, 1, 2, or 3; R and R 1 are each independently H, F, Cl, Br, I, CN, SCN, SF5, straight-chain or branched alkyl having 1 or 3 to 25 carbon atoms (which may be mono- or polysubstituted with F, Cl, Br, I or CN), and one or more non-adjacent CH2 groups may be -O-, -S-, -NH-, -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-, -NR29-, -NR30-, -NR31-, -NR32-, -NR33-, -NR44-, -NR45-, -NR46-, -NR47-, -NR48-, -NR59-, -NR50-, -NR51-, -NR52-, -NR53-, -NR54-, -NR55-, -NR56-, -NR57-, -NR58-, -NR59 ...0-, -NR51-, -NR51-, -NR52-, -NR53-, -NR54-, -NR55-, -NR56-, -NR57-, -NR58-, -NR59-, -NR59-, -NR59-, -NR 0 -, -CO-, -COO-, -OCO-, -O-COO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C-), or a polymerizable group.

[0347] Chiral binaphthyl derivatives of formula A-VI-1 are particularly preferred.

[0348] [ka]

[0349] In the formula, rings B, R 0 and Z0 is as defined for Formulas A-IV and AV, and b is 0, 1, or 2.

[0350] In particular, they are selected from the following formulae A-VI-1a to A-VI-1c:

[0351] [ka]

[0352] In the formula, rings B, R 0 and Z 0 is as defined for formula A-VI-1, R 0 is as defined for formula A-IV, or is H or alkyl having 1 to 4 carbon atoms; b is 0, 1 or 2; Z 0 is in particular -OC(O)- or a single bond.

[0353] The concentration of one or more chiral dopants (single or multiple) in the LC medium is preferably in the range of 0.001% to 20%, preferably 0.05% to 5%, more preferably 0.1% to 2%, and most preferably 0.5% to 1.5%. These preferred concentration ranges apply in particular to chiral dopants S-4011 or R-4011 (both from Merck) and chiral dopants with the same or similar HTP. For chiral dopants with higher or lower absolute HTP values ​​compared to S-4011, these preferred concentrations should be proportionally reduced or increased, respectively, according to the ratio of their HTP value to that of S-4011.

[0354] The pitch p of the LC media or host mixtures according to the invention is preferably in the range from 5 to 50 μm, more preferably from 8 to 30 μm, particularly preferably from 10 to 20 μm.

[0355] Preferably, the medium according to the invention comprises an antioxidant, preferably a stabilizer selected from the group of the hindered phenol antioxidants and hindered amine light stabilizers (HALS), more preferably from the group of compounds of formulae ST-1 to ST-18

[0356] [ka]

[0357] [ka]

[0358] [ka]

[0359] [ka] During the ceremony, R ST represents H, alkyl or alkoxy having 1 to 15 C atoms, wherein, further, one or more non-adjacent CH groups in these groups may each independently be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, ... [ka] -O-, -CO-O- or -O-CO-O-, wherein further, one or more H atoms may be replaced by halogen; [ka] [ka] represents Z STrepresent, independently of one another, -CO-O-, -O-CO-, -CF2O-, -OCF2-, -C2O-, -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; L 1 and L 2 each independently represent F, Cl, CF3 or CHF2, p is 1 or 2; q is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0360] Among the compounds of formula ST, the compounds of formula:

[0361] [ka]

[0362] [ka]

[0363] [ka]

[0364] In the compounds of formulae ST-3a and ST-3b, n preferably represents 3. In the compounds of formula ST-2a, n preferably represents 7.

[0365] Very particularly preferred mixtures according to the invention comprise one or more stabilizers from the group of the compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12.

[0366] [ka]

[0367] [ka]

[0368] The compounds of the formulae ST-1 to ST-18 are preferably each present in the liquid crystal mixture according to the invention in an amount of 0.005 to 0.5%, based on the mixture.

[0369] If the mixture according to the invention comprises two or more compounds from the group of compounds of formulae ST-1 to ST-18, then the concentration increases to 0.01 to 1% for two compounds, correspondingly, based on the mixture.

[0370] However, the total proportion of compounds of the formulae ST-1 to ST-18, based on the mixture according to the invention, should not exceed 2%.

[0371] According to another aspect of the present invention, an optical component comprises a polymer network liquid crystal obtained by polymerizing one or more compounds of formula P as defined below in a liquid crystal host mixture comprising one or more compounds selected from the group consisting of compounds of formulas I, II and III as defined above. A is, for example, as described in Peng, Fenglin, Chen, Haiwei, Tripathi, Suvagata, Twieg, Robert, Wu, Shin-Tson (2015) Fast-response infrared phase modulator based on polymer network liquid crystal. Optical Materials Express. Vol. 5, No. 2, pp. 265-273. doi:10.1364 / OME.5.000265.

[0372] [ka]

[0373] wherein the individual groups have the following meanings: P a , P beach independently represents a polymerizable group, Sp a , Sp b represents a spacer group, which may be the same or different in each occurrence; s1 and s2 each independently represent 0 or 1; A 1 , A 2 each independently represents a group selected from the following group: a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene and 1,4'-bicyclohexylene, wherein in addition one or more non-adjacent CH groups may be replaced by -O- and / or -S-, and in addition one or more H atoms may be replaced by F; b) the group consisting of 1,4-phenylene and 1,3-phenylene, in which in addition one or two CH groups may be replaced by N, and in which in addition one or more H atoms may be replaced by L; c) the group consisting of tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobuta-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may be mono- or polysubstituted by L; d) polycyclic groups having 5 to 20 ring C atoms which may be saturated, partially unsaturated or fully unsaturated, in addition one or more of which may be replaced by a heteroatom, preferably [ka] selected from the group consisting of provided that one or more H atoms in these groups may be replaced by L, and / or one or more double bonds may be replaced by single bonds, and / or one or more CH groups may be replaced by N; n2 represents 0, 1, 2 or 3; Z aare in each case independently of one another -CO-O-, -O-CO-, -CHO-, -OCH-, -CFO-, -OCF- or -(CH) n -, where n is 2, 3, or 4, and -O-, -CO-, -C(R y R z )-, -CH2CF2-, -CF2CF2- or a single bond; L in each occurrence is the same or different and represents F, Cl, CN, SCN, SF5 or linear or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, R y , R z each independently represent H, F or linear or branched alkyl having 1 to 12 C atoms, provided that in addition one or more H atoms may be replaced by F, M is -O-, -S-, -CH2-, -CHY 1 -or-CY 1 Y 2 - represents Y 1 and Y 2 are each independently R y has one of the meanings given above or represents Cl or CN.

[0374] Polymerizable group P a、b is a group suitable for polymerization reactions, such as, for example, free-radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-analogous reactions, such as, for example, addition or condensation onto a polymer backbone. Groups for chain polymerization, especially those containing a C=C double bond or a C≡C triple bond, and groups suitable for ring-opening polymerization, such as, for example, oxetane or epoxide groups, are particularly preferred.

[0375] Preferred group P a、b is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, [ka] CH2=CW 2 -(O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -, HS-CW 2 W 3 -, HW 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si—, wherein W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, and W 2 and W 3 each independently of one another denotes H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 carbon atoms, W 7 and W 8each independently represent H, Cl or alkyl having 1 to 5 C atoms; Phe represents 1,4-phenylene which may be substituted with one or more groups L as defined above and different from P-Sp; k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0376] Particularly preferred groups P a、b is CH2=CW 1 -CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, further CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-, [ka] is selected from the group consisting of:

[0377] Very particularly preferred groups P a、b is selected from the group consisting of acrylate, methacrylate, fluoroacrylate, vinyloxy, chloroacrylate, oxetane and epoxide groups, of which the acrylate or methacrylate group is preferred.

[0378] Preferred spacer groups Sp a、b is the group P a / b -Sp a / b - is the formula P a / b -Sp"-X"-, where: Sp" represents alkylene having 1 to 20, preferably 1 to 12, C atoms, which may be mono- or polysubstituted by F, Cl, Br, I or CN, provided that in addition, one or more non-adjacent CH groups are each independently of one another -O-, -S-, -NH-, -N(R 0 )-, -Si(R 00 R 000)-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-, -O-CO-N(R 00 )-, -N(R 00 )-CO-N(R 00 )-, -CH=CH- or -C≡C-, “X” is -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 00 )-, -N(R 00 )-CO-, -N(R 00 )-CO-N(R 00 )-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -, -CY 3 =CY 4 represents -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond; R 0 , R 00 and R 000 each independently represent H or alkyl having 1 to 12 C atoms, and Y 3 and Y 4 are the same or different and represent H, F, Cl, or CN.

[0379] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, or -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 0 - or a single bond.

[0380] A typical spacer group Sp" is, for example, -(CH2) p1 -, -(CH2CH2O) q1-CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR 00 R 000 -O) p1 wherein p1 is an integer of 1 to 12, q1 is an integer of 1 to 3, and R 00 and R 000 has the meaning given above.

[0381] Particularly preferred groups -Sp"-X"- are -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -O-CO-O-, in which p1 and q1 have the meanings given above.

[0382] Particularly preferred radicals Sp" are, for example, in each case linear ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0383] Particularly preferred monomers of formula P are:

[0384] [ka]

[0385] [ka]

[0386] [ka]

[0387] [ka]

[0388] [ka]

[0389] [ka]

[0390] wherein the individual groups have the following meanings: P 1 , P 2 and P 3 each independently represent a polymerizable group as defined by formula P, preferably an acrylate, methacrylate, fluoroacrylate, oxetane, vinyloxy or epoxide group, Sp 1 , Sp 2 and Sp 3 are each independently a single bond or a spacer group, preferably Sp a has one of the meanings given above and below, particularly preferably -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -CO-O- or -(CH2) p1 represents -O-CO-O-, where p1 is an integer from 1 to 12, provided that in the last-mentioned group the connection to the adjacent ring occurs via an O atom, However, the additional group P 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 -At least one of R aa one or more groups P, provided that they do not represent 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 - is the group R aa It can be expressed as Raa is H, F, Cl, CN or linear or branched alkyl having 1 to 25 C atoms, provided that in addition one or more non-adjacent CH groups are each independently of one another such that the -O- and / or -S- atoms are not directly linked to one another, 0 )=C(R 00 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition one or more H atoms may be replaced by F, Cl, CN or P 1 -Sp 1 -, particularly preferably linear or branched, mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having 1 to 12 C atoms, with the proviso that alkenyl and alkynyl groups have at least 2 C atoms and branched groups have at least 3 C atoms, R 0 and R 00 each independently represent H or alkyl having 1 to 12 C atoms, R y and R z each independently represents H, F, CH3 or CF3, Z p1 -O-, -CO-, -C(R y R z )- or -CF2CF2-, Z p2 and Z p3 are each independently -CO-O-, -O-CO-, -CHO-, -OCH-, -CFO-, -OCF- or -(CH) n3 -, where n3 is 2, 3, or 4; L is, in each occurrence, identically or differently, F, Cl, CN, SCN, SF5, or an alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 carbon atoms, which may be linear or branched and monofluorinated or polyfluorinated, preferably F; L' and L" each independently represent H, F or Cl; r represents 0, 1, 2, 3 or 4; s represents 0, 1, 2 or 3; t represents 0, 1 or 2; x represents 0 or 1.

[0391] In a particularly preferred embodiment of the invention, the LC mixture comprises one or more compounds of formula P10-1.

[0392] [ka]

[0393] where the parameters are defined as above and P 1 and P 2 preferably represents an acrylate or methacrylate.

[0394] Particularly preferred compounds of formula P10-1 are selected from the group of the following subformulae:

[0395] [ka]

[0396] wherein each n4 represents, independently of one another, an integer between 2 and 10, preferably 3, 4, 5 or 6.

[0397] In one embodiment of the present invention, the liquid crystal composition is injected between the first and second substrates, or is filled into the cell by capillary force after combining the first and second substrates. In an alternative embodiment, the liquid crystal composition may be loaded onto the first substrate, and then the second substrate may be combined with the first substrate, sandwiching the liquid crystal composition between the first and second substrates.

[0398] The total amount of compounds of formula P in the medium is in the range of from above 0% to 20%, preferably from 2% to 15%, very preferably from 3% to 10%, in particular 4%, 5%, 6%, 7% or 8%.

[0399] The polymerizable compound is polymerized or crosslinked (if the polymerizable compound contains two or more polymerizable groups) in the LC medium between the substrates of the optical component, optionally under the application of a voltage, in an in situ polymerization. The polymerization can be carried out in one step or in two or more steps ("final cure").

[0400] Suitable and preferred polymerization methods include, for example, thermal or photopolymerization, preferably photopolymerization, especially UV photopolymerization. One or more initiators can also be added. Suitable polymerization conditions and suitable types and amounts of initiators are known to those skilled in the art and are described in the literature. For example, commercially available photopolymerization initiators such as Irgacure 651®, Irgacure 184®, Irgacure 907®, Irgacure 369®, or Darocure 1173® (BASF) are suitable for free-radical polymerization. When an initiator is used, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

[0401] The polymerizable compound according to the present invention is also suitable for polymerization without initiator, which has significant advantages, such as lower material costs and, in particular, less contamination of the LC medium by residual amounts of initiator or its decomposition products.Therefore, polymerization can also be carried out without adding initiator.Therefore, in a preferred embodiment, the LC medium does not contain a polymerization initiator.

[0402] The polymerizable component or the LC medium may also contain one or more stabilizers, for example to prevent undesired spontaneous polymerization of the RM during storage or transportation. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Commercially available stabilizers from the Irganox® series (BASF), such as Irganox® 1076, are particularly suitable. When stabilizers are used, their proportion is preferably 10 to 10,000 ppm, highly preferably 50 to 500 ppm, based on the total amount of the RM or polymerizable component.

[0403] Other mesogenic compounds not explicitly mentioned above can also optionally and advantageously be used in the media according to the invention, such compounds being known to those skilled in the art.

[0404] In a preferred embodiment of the invention, the liquid-crystalline medium comprises a total of at least 30%, preferably at least 40%, particularly preferably at least 50%, of compounds of the formula I, which are preferably selected from the group of the compounds of the formulae I-1, I-2 and I-3, particularly preferably selected from the compounds of the formulae I-2 and I-3.

[0405] In another preferred embodiment of the invention, the liquid-crystalline medium comprises a total of not more than 20%, preferably not more than 18%, particularly preferably not more than 15%, of compounds of formula I, which are preferably selected from the group of the compounds of the formulae I-1, I-2 and I-3, particularly preferably selected from the compounds of the formulae I-2 and I-3.

[0406] Preferably, the proportion of compounds of formula I-1 in the medium is less than or equal to 20%, more preferably less than or equal to 15%, particularly preferably less than or equal to 10%, very particularly preferably less than or equal to 5%.

[0407] In a preferred embodiment, the medium comprises one or more compounds of formula I-2 in a total concentration in the range of 5% to 25%, more preferably 7% to 25%, particularly preferably 10% to 20%.

[0408] In another preferred embodiment, the medium comprises one or more compounds of formula I-2 in a total concentration of less than or equal to 10%, preferably less than or equal to 5%, particularly preferably less than or equal to 2%.

[0409] In a preferred embodiment, the medium contains the compound of formula I-3 in an amount of preferably 5% to 50%, more preferably 10% to 40%, particularly preferably 15% to 35%.

[0410] In a preferred embodiment, the total concentration of compounds of formula I-3 in the medium according to the invention is greater than or equal to 20%, more preferably greater than or equal to 25%, particularly preferably greater than or equal to 30%.

[0411] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula II and / or RO-2, preferably of formula II-1 and / or RO-2, in a total concentration of 5% to 40%, more preferably 10% to 37%, particularly preferably 15% to 35%.

[0412] Preferably, the medium comprises one or more compounds of formula II-1.

[0413] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula II-1 in a total concentration of not more than 25%, more preferably not more than 20%, particularly preferably not more than 15%, very particularly preferably not more than 10%.

[0414] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula III, preferably formula III-1, very preferably formula III-1b, in a total concentration of 2% to 30%, more preferably 5% to 25%, very preferably 10% to 25%, in particular 10% to 20%.

[0415] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula RO in a total concentration ranging from 2% to 35%, more preferably from 5% to 30%, particularly preferably from 7% to 25%.

[0416] In a preferred embodiment of the invention the liquid-crystalline medium preferably comprises in total 5% to 35%, preferably 10% to 32%, particularly preferably 20% to 30% of compounds of the formula T.

[0417] In a preferred embodiment of the invention the liquid-crystalline medium comprises in total not more than 30%, preferably not more than 15%, particularly preferably not more than 10% of compounds of the formula T.

[0418] Preferably, the medium comprises one or more compounds of formula C, preferably in a total concentration in the range of 5% to 50%, preferably 10% to 40%, particularly preferably 15% to 30%.

[0419] In further preferred embodiments of the invention, alone or in combination with each other, the following, except that some compounds are abbreviated using the abbreviations given in Table C:

[0420] the medium comprises one or more compounds of formula RO and one or more compounds of formula T;

[0421] The medium comprises one or more compounds of formula T-1;

[0422] The medium comprises one or more compounds of formula T-2;

[0423] The medium comprises one or more compounds of formula T-1 and T-2;

[0424] the medium comprises one or more compounds of formula T-1 and / or T-2 and one or more compounds of formula I and / or II and / or III;

[0425] The medium comprises one or more compounds of formula III-1;

[0426] The medium comprises two or more compounds of formula T-1;

[0427] The medium comprises two or more compounds of formula T-2;

[0428] The medium contains the compound PPU-TO-S;

[0429] the medium comprises one or more compounds of the formula RO and one or more compounds of the formula III-1, in particular the formula RO-2 and the formula III-1b, preferably in a total concentration in the range of 20-70%, more preferably 30-65%, very preferably 35-62%, particularly preferably 40-60%;

[0430] · the medium contains one or more compounds of formula PPTU-nS and / or PPTU-(cn)mS in a total concentration in the range of 10-20%;

[0431] the medium comprises one or more compounds of formula PTPU-nS and / or PTPU-(cn)mS in a total concentration in the range of 10-20%;

[0432] The medium contains one or more compounds of formula PPTU-nS and PGTU-nS in a total concentration in the range of 15-25%.

[0433] The liquid-crystalline media according to the present invention preferably have a clearing point of 90°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, more preferably 120°C or higher, even more preferably 130°C or higher, particularly preferably 140°C or higher, and very particularly preferably 150°C or higher.

[0434] The liquid-crystalline media according to the invention preferably have a clearing point of 160°C or less, more preferably 140°C or less, particularly preferably 120°C or less and very particularly preferably 100°C or less.

[0435] The nematic phase of the media according to the invention preferably extends from at least below 0° C. to above 90° C. The media according to the invention advantageously exhibit an even wider nematic phase range, preferably from at least below −10° C. to above 120° C., very preferably from at least below 20° C. to above 140° C., particularly preferably from at least below 30° C. to above 150° C., and very particularly preferably from at least below 40° C. to above 170° C.

[0436] The Δε at 1 kHz and 20° C. of the liquid-crystalline media according to the invention is preferably 10 or more, more preferably 15 or more, very preferably 18 or more.

[0437] 589 nm (Na D ) and birefringence (Δn) at 20° C. is preferably 0.280 or more, more preferably 0.300 or more, even more preferably 0.320 or more, very preferably 0.330 or more, and especially 0.350 or more.

[0438] 589 nm (Na D ) and Δn at 20° C. is preferably in the range of 0.200 to 0.900, more preferably in the range of 0.250 to 0.800, even more preferably in the range of 0.300 to 0.700, and very particularly preferably in the range of 0.350 to 0.600.

[0439] In a preferred embodiment of the present invention, the Δn of the liquid-crystalline media according to the present invention is preferably ≧0.50, more preferably ≧0.55.

[0440] The compounds of formulas I to III in each case include dielectrically positive compounds having a dielectric anisotropy greater than 3, dielectrically neutral compounds having a dielectric anisotropy less than 3 and greater than -1.5, and dielectrically negative compounds having a dielectric anisotropy of -1.5 or less.

[0441] The compounds of formulae I, II and III are preferably dielectrically positive.

[0442] However, in some embodiments, liquid crystals with negative values ​​of dielectric anisotropy can also be used to advantage.

[0443] Preferably, the optical component according to the invention is arranged and configured as an optical phase modulator.

[0444] In one preferred embodiment, optical components according to the present invention are designed and constructed for use in transmissive devices for phase modulation of IR radiation.

[0445] In another preferred embodiment, an optical component according to the present invention is designed and constructed for use in a reflective device for phase modulation of IR radiation.

[0446] A typical electro-optic modulator includes a conductive infrared-transmitting window, eg, made of Ge, separated by a spacer, and has a cell gap in the range of 1 mm to 5 mm.

[0447] According to another aspect of the present invention, there is provided a LIDAR scanning system as described in WO 2018 / 156643, including a laser configured to emit light pulses at an operating wavelength in the infrared. The LIDAR scanning system includes a transmit reconfigurable metasurface configured to reflect incident light pulses from the laser as an illumination beam directed toward a selected portion of a field of view, preferably a two-dimensional field of view. The aiming of the illumination beam is responsive to a first selected holographic beam steering pattern implemented in the transmit reconfigurable metasurface. The system further includes a receive reconfigurable metasurface configured to reflect a returning illumination beam from the selected portion of the field of view as a relay beam directed toward an optical detector. The aiming of the relay beam is responsive to a second selected holographic beam steering pattern implemented in the receive reconfigurable metasurface. The system includes a photodetector including an array of detector pixels. Each detector pixel includes (i) a photodetector configured to detect the returning illumination beam and (ii) a timing circuit configured to determine the time-of-flight of the detected light. The photodetector is also configured to output a detection signal indicative of the detected light and the time-of-flight of the detected light for each pixel of the array. The transmit reconfigurable metasurface includes a plurality of dynamically tunable high-Q dielectric resonators arranged on a surface of the reconfigurable metasurface with an element spacing smaller than the operating wavelength of the laser, wherein the surface of the reconfigurable metasurface includes a conductive surface, and the plurality of resonators provide dynamically tunable reflected waves responsive to incident waves and have a corresponding plurality of tunable reflection phases, wherein the conductive surface and the plurality of resonators define a metasurface. Each of the plurality of dielectric resonators includes (i) a pair of regions having a high refractive index and (ii) an electrically tunable material disposed in a gap between the regions, the electrically tunable material being a liquid crystal material defined above and below.

[0448] 1, in accordance with another aspect of the present invention, a reflective spatial light modulator, specifically an LCoS device 100, is provided, 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 backplane 160, and a PCB mounting (not shown). The mirror is divided into a two-dimensional array of individually addressable pixels. Each pixel can be individually driven by a voltage signal to impart a localized phase change to at least one polarization component of an 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.

[0449] The LCoS devices are useful for integration into optical devices, with preferred devices being wavelength selective switches (WSS), LIDAR scanners, infrared scene projectors, and other beam steering applications as shown in the paper Micallef, F. (2019). Middle infrared beam-steering using liquid crystals for spatial light modulation (PhD thesis). https: / / doi.org / 10.17863 / CAM.39602 (https: / / www.repository.cam.ac.uk / handle / 1810 / 292443).

[0450] In this application, the expression "dielectrically positive" refers to a compound or component with Δε > 3.0, dielectrically neutral refers to those with -1.5 ≦ Δε ≦ 3.0, and dielectrically negative refers to those with Δε < -1.5. Δε is determined at a frequency of 1 kHz and 20°C. The dielectric anisotropy of each compound is determined from a 10% solution of each individual compound in a nematic host mixture. If the solubility of each compound in the host mixture is less than 10%, the concentration is reduced to 5%. The capacitance of the test mixtures is determined in both cells with homeotropic alignment and cells with homogeneous alignment. The cell thickness of both types of cells is approximately 20 μm. The applied voltage is a square wave with a frequency of 1 kHz and an effective value typically between 0.5 V and 1.0 V, which is always selected to be below the capacitance threshold of each test mixture.

[0451] Δε is (ε ∥ -ε ⊥ ), while ε ave is (ε ∥ +2ε ⊥ ) / 3.

[0452] The host mixture used to determine the physical constants of the pure compounds by extrapolation is ZLI-4792 from Merck, Germany. The absolute values ​​of the dielectric constant, birefringence (Δn), and rotational viscosity (γ1) of the compound are determined from the change in the respective values ​​of the host mixture upon addition of the compound. The concentration in the host is 10% or 5% if solubility is insufficient. The values ​​are extrapolated to 100% for the added compound.

[0453] In the examples the phase sequences of the pure compounds are given using the following abbreviations: K: crystalline, N: nematic, SmA: smectic A, SmB: smectic B, I: isotropic.

[0454] Components that have a nematic phase at a measurement temperature of 20°C are measured as they are, and other components are treated in the same manner as compounds.

[0455] In any case, unless otherwise specified, the term "threshold voltage" in this application refers to the optical threshold voltage at which 10% relative contrast (V 10 ) and the expression "saturation voltage" refers to optical saturation and 90% relative contrast (V 90 ) is quoted. The capacitance threshold voltage (V0) is the Fredericks threshold (V Fr ) and should only be used when explicitly stated.

[0456] All parameter ranges given herein are inclusive unless otherwise stated.

[0457] The different upper and lower limits set forth for the various range properties may be combined with each other to create additional preferred ranges.

[0458] Throughout this application, the following conditions and definitions apply unless stated otherwise: All concentrations are quoted in weight percent, all temperatures are quoted in degrees Celsius, and all temperature differences are quoted in degrees Celsius, with respect to the respective mixture total. All physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals," November 1997, Merck, Germany, and are quoted for a temperature of 20°C unless stated otherwise. The optical anisotropy (Δn) is determined at a wavelength of 589.3 nm. The dielectric anisotropy (Δε) is determined at a frequency of 1 kHz. The threshold voltage as well as all other electro-optical properties are determined using test cells manufactured by Merck. The test cells for determining Δε have a cell thickness of approximately 20 μm. The electrodes are 1.13 cm thick. 2 The ITO electrode is a circular electrode with an area of ​​100 μm and a guard ring. The alignment layer provides homeotropic alignment (ε ∥ ) is SE-1211 manufactured by Nissan Chemical Co., Ltd., Japan, and homogeneous orientation (ε ⊥ The capacitor is made of polyimide AL-1054 manufactured by Japan Synthetic Rubber Co., Ltd. The capacitance is 0.3V rmsThe characteristic voltage is determined using a Solatron 1260 frequency response analyzer using a sine wave with a voltage of 1000 Hz. The light used for the electro-optical measurements is white light. In this specification, an instrument configuration using a DMS device commercially available from Autronic-Melchers, Germany, is used. The characteristic voltage was determined under normal observation. The threshold voltage (V 10 ), medium gray (V 50 ) and saturation (V 90 ) voltages were determined at 10%, 50% and 90% relative contrast, respectively.

[0459] In this application, the term compound is intended to refer to both one compound and multiple compounds, unless otherwise specified.

[0460] All mixtures according to the invention are nematic. The liquid-crystalline media according to the invention preferably have a nematic phase within the preferred ranges given above. Having a nematic phase here means, on the one hand, that no smectic phase or crystallization is observed at the corresponding temperature, and, on the other hand, that no clearing occurs upon heating from the nematic phase. At high temperatures, the clearing point is measured in capillaries using conventional methods. Low-temperature studies are carried out at the corresponding temperature using a flow viscometer and confirmed by storage of bulk samples. The bulk storage stability (LTS) 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 is filled into a sealed glass container (bottle) of appropriate size, placed in a refrigerator at the specified temperature. The bottles are checked at defined time intervals for the appearance of smectic phases or crystallization. Two bottles are stored for each material and at each temperature. If crystallization or the appearance of a smectic phase is observed in at least one of the two corresponding bottles, the test is terminated, and the last inspection time before the appearance of a higher-order phase 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 at a given temperature for at least 1000 hours.

[0461] The liquid-crystalline media according to the invention may contain further additives and chiral dopants in the usual concentrations. The total concentration of these further components is in the range of 0% to 10%, preferably 0.1% to 6%, based on the total mixture. The concentrations of the individual compounds used are preferably in the range of 0.1% to 3%. The concentrations of these and similar additives are not taken into account when citing the values ​​and concentration ranges of the liquid-crystalline compounds of the liquid-crystalline media in this application.

[0462] Preferably, the media according to the invention comprise one or more chiral compounds as chiral dopants to adjust their cholesteric pitch, the total concentration of which in the media according to the invention is preferably in the range of 0.05% to 15%, more preferably 1% to 10%, most preferably 2% to 6%.

[0463] Optionally, the media according to the invention contain further liquid crystal compounds to adjust the physical properties. Such compounds are known to those skilled in the art. Their concentration in the media according to the invention is preferably 0% to 30%, more preferably 0.1% to 20%, most preferably 1% to 15%.

[0464] The response time is the time (t 90 -t0), that is, the delay time (t 10 -t0) including the rise time (τ on ) and the time (t) for the relative tuning of the electro-optic response to change from 100% back to 10%, respectively. 100 -t 10 ) versus decay time (τ off ) and the total response time (τ total =τ on +τ off ) are shown respectively.

[0465] The liquid-crystalline media according to the present invention comprise a plurality of compounds, preferably 3 to 30, more preferably 4 to 20, and very preferably 4 to 16 compounds. These compounds are mixed in the usual manner. In general, the desired amount of the compound used in a smaller amount is dissolved in the compound used in a larger amount. It is particularly easy to observe the completion of the dissolution process when the temperature is higher than the clearing point of the compound used in a higher concentration. However, it is also possible to prepare the media using other conventional methods, such as so-called premixes, whose components are ready-to-use mixtures, for example, homogeneous mixtures or eutectic mixtures of compounds, or, for example, using so-called "multi-bottle" systems.

[0466] All temperatures are quoted in degrees Celsius, e.g., melting points T(C,N) or T(C,S), smectic (S) to nematic (N) phase transitions T(S,N), and liquid crystal clearing points T(N,I). All temperature differences are quoted in degrees Celsius.

[0467] In the present invention and in particular in the following examples, the structures of the mesogenic compounds are represented by abbreviations, also called acronyms. These acronyms are used in tables A to D below 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 , C m H 2m and C l H2 represents a straight-chain alkyl or alkenyl, preferably 1E-alkenyl, 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 groups. Table C gives the meaning of the codes for the left-hand or right-hand terminal groups. Table D shows exemplary structures of compounds, along with their respective abbreviations.

[0468] <Table A: Ring elements>

[0469] [Table 1]

[0470] [Table 2]

[0471] [Table 3]

[0472] [Table 4]

[0473] [Table 5]

[0474] [Table 6]

[0475] <Table B: Linking group>

[0476] [Table 7]

[0477] <Table B: Terminal group>

[0478] [Table 8]

[0479] In the table, n and m each represent an integer, and the three dots "..." are places for other abbreviations from this table.

[0480] The following table shows exemplary structures with their respective abbreviations, which are provided to illustrate the meaning of the abbreviation rules, which further represent preferred compounds for use:

[0481] Table C: Exemplary Structures The following exemplary structures are compounds that are preferably additionally used in the medium.

[0482] [Table 9]

[0483] [Table 10]

[0484] [Table 11]

[0485] [Table 12]

[0486] [Table 13]

[0487] [Table 14]

[0488] [Table 15]

[0489] [Table 16]

[0490] [Table 17]

[0491] [Table 18]

[0492] [Table 19]

[0493] [Table 20]

[0494] [Table 21]

[0495] [Table 22]

[0496] [Table 23]

[0497] In the table, m and n are the same or different and are 1, 2, 3, 4, 5, 6, or 7.

[0498] Preferably, the medium according to the invention comprises one or more compounds selected from the compounds of Table C.

[0499] The following table, Table D, shows exemplary compounds that can be used as alternative stabilizers in mesogenic media according to the invention. The total concentration of these and similar compounds in the media is preferably 5% or less.

[0500]

[0501] [Table 24]

[0502] [Table 25]

[0503] In a preferred embodiment of the present invention the mesogenic medium comprises one or more compounds selected from the group of compounds from Table D.

[0504] The following table, Table E, shows exemplary compounds which can be preferably used as chiral dopants in the mesogenic media according to the present invention.

[0505]

[0506] [Table 26]

[0507] [Table 27]

[0508] [Table 28]

[0509] In a preferred embodiment of the invention the mesogenic medium comprises one or more compounds selected from the group of compounds in Table E.

[0510] 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 in the table above.

[0511] Without further elaboration, it is believed that using the preceding description, one skilled in the art can utilize the present invention to its fullest extent. The following examples are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way. From this description, one skilled in the art can readily grasp the essential features of the present invention, and can make various changes and modifications to adapt the present invention to various uses and conditions without departing from the spirit and scope thereof. [Example]

[0512] Comparative mixture C1 and example mixtures N1-N22 for use according to the invention are prepared having the compositions and properties as shown in the table below and are characterized with respect to their general physical properties and their applicability in optical components.

[0513] Optical components comprising a medium according to the invention as defined in claim 1 and produced according to a process as defined in claim 12 are distinguished by excellent operational stability when exposed to the environment due to the high clearing temperature, wide nematic phase range and excellent low-temperature stability (LTS) of the liquid-crystalline medium used therein. As a result, the components and devices comprising them can operate under extreme temperature conditions. Surprisingly, the temperature dependence of the birefringence of the liquid-crystalline medium is very small, i.e., Δn varies very little with temperature, making the devices reliable and easy to control.

[0514] <Comparison mixture C1>

[0515] [Table 29]

[0516] <Example N1>

[0517] [Table 30]

[0518] <Example N2>

[0519] [Table 31]

[0520] The birefringence of comparative mixture C-1 and mixture examples N-1 and N-2 is determined at 20° C. and 60° C. The results are shown in Table 1.

[0521]

[0522] [Table 32]

[0523] Surprisingly, the ratio Δn20 / Δn60 is advantageously small for the media according to the invention, ie they exhibit less variation of birefringence with temperature compared to state-of-the-art media.

[0524] <Example N3>

[0525] [Table 33]

[0526] <Example N4>

[0527] [Table 34]

[0528] <Example N5>

[0529] [Table 35]

[0530] <Example N6>

[0531] [Table 36]

[0532] <Example N7>

[0533] Table 37

[0534] <Example N8>

[0535] Table 38

[0536] <Example N9>

[0537] Table 39

[0538] <Example N10>

[0539] Table 40

[0540] <Example N11>

[0541] Table 41

[0542] <Example N12>

[0543] Table 42

[0544] <Example N13>

[0545] Table 43

[0546] <Example N14>

[0547] Table 44

[0548] <Example N15>

[0549] Table 45

[0550] <Example N16>

[0551] Table 46

[0552] <Example N17>

[0553] Table 47

[0554] <Example N18>

[0555] Table 48

[0556] <Example N19>

[0557] Table 49

[0558] <Example N20>

[0559] Table 50

[0560] <Example N21>

[0561] [Table 51]

[0562] <Example N22>

[0563] [Table 52]

[0564] Furthermore, the media according to the invention are distinguished by a high clearing temperature combined with excellent low-temperature stability, ie they have a very wide operating temperature range.

[0565] Furthermore, the media according to the invention exhibit a surprisingly low threshold voltage V0.

[0566] Surprisingly, media comprising compounds RO with alkoxy side chains have a much higher birefringence and a higher clearing temperature than media containing exclusively compounds with alkyl side chains.

Claims

1. An optical component (100) operable in the infrared region of the electromagnetic spectrum, comprising: a liquid crystal medium (140) sandwiched between a first substrate (110) and a second substrate (160) facing each other; first and second electrodes (120, 150) for applying an electrical potential across said liquid crystal medium to drive the liquid crystal in a predetermined configuration; said liquid-crystalline medium comprises one or more compounds selected from the group of compounds of the formulae I, II and III and one or more compounds of the formula RO, Component characterized in that the liquid-crystalline medium comprises, as the compound of formula RO, one or more compounds of formula PTU-nO-S and one or more compounds of formula PTG-nO-S. 【Chemistry 1】 (In the formula, R １ represents H, linear or branched alkyl having 1 to 12 C atoms or linear or branched alkenyl having 2 to 15 C atoms, provided that one or more CH ２ The base is 【Chemistry 2】 may be replaced by n is 0, 1 or 2; 【Transformation 3】 occur independently of each other, 【Chemistry 4】 represents In the formula R Ｌ are identical or different at each occurrence H or alkyl having 1 to 6 C atoms, provided that 【Transformation 5】 is substituted, 【Transformation 6】 represents R ２ represents H, linear or branched alkyl having 1 to 12 C atoms or linear or branched alkenyl having 2 to 15 C atoms, provided that one or more CH ２ The base is 【Transformation 7】 may be replaced by Z ２１ represents trans-CH=CH-, trans-CF=CF- or -C≡C-; 【Transformation 8】 are independent of each other, 【Chemistry 9】 represents In the formula R Ｌ are identical or different at each occurrence and represent H or alkyl having 1 to 6 C atoms, R ３ represents H, linear or branched alkyl having 1 to 12 C atoms or linear or branched alkenyl having 2 to 15 C atoms, provided that one or more CH ２ The base is 【Chemistry 10】 may be replaced by Z ３１ and Z ３２ one of the groups represents trans-CH=CH-, trans-CF=CF-, or -C≡C-, and independently the other group represents -C≡C-, trans-CH=CH-, trans-CF=CF-, or a single bond; 【Chemistry 11】 are independent of each other, 【Chemistry 12】 represents In the formula R Ｌ are identical or different at each occurrence H or alkyl having 1 to 6 C atoms, provided that 【Chemistry 13】 is substituted, 【Chemistry 14】 Represents.) 【Chemistry 15】 (In the formula, R ＲＯ represents a linear or branched alkyl having 1 to 12 C atoms or a linear or branched alkenyl having 2 to 12 C atoms, provided that in each case one or more CH ２ The base is 【Chemistry 16】 may be replaced by Z Ｔ１ , Z Ｔ２ are the same or different and represent —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C≡C—, or a single bond, X １ , X ２ , X ３ and X ４ are the same or different and are H, Cl, F or CH ３ represents t is 0 or 1, and 【Chemistry 17】 represents a group selected from the following groups: a) the group consisting of 1,4-phenylene, 1,4-naphthylene and 2,6-naphthylene, wherein one or two CH groups may be replaced by N, and wherein one or more H atoms may be replaced by L; b) the group consisting of thiophene-2,5-diyl, thieno[3,2-b]thiophene-2,5-diyl, selenophene-2,5-diyl, furan-2,5-diyl, each of which may be mono- or polysubstituted by L; L, identically or differently in each occurrence, represents F, Cl or linear or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms. 【Chemistry 20】 (wherein n is independently 1, 2, 3, 4, 5, 6, or 7).

2. 2. Component comprising a liquid-crystalline medium according to claim 1, in which the total concentration of the one or more compounds of the formula RO is in the range from 2% to 35% by weight.

3. One or more compounds of formulae RO-1 to RO-7 (excluding compounds of formulae PTU-nO-S and PTG-nO-S) 3. A component comprising a liquid-crystalline medium according to claim 1, further comprising: [Chemistry 18] (In the formula, X １ and X ２ is H, Cl, F or CH ３ represents R ＲＯ 、 【Chemistry 19】 has the meaning given in claim 1.

4. R ＲＯ 4. A component comprising a liquid-crystalline medium according to claim 1, further comprising one or more compounds of the formula RO, in which R represents cyclic alkyl.

5. Component comprising a liquid-crystalline medium according to any one of claims 1 to 4, wherein the liquid-crystalline medium comprises one or more compounds of formula T 【Chemistry 21】 (In the formula, R Ｔ is halogen, CN, NCS, R Ｆ , R Ｆ -O- or R Ｆ represents —S—, where R Ｆ represents a fluorinated alkyl or alkenyl having up to 12 C atoms, 【Chemistry 22】 represents L ４ and L ５ are the same or different and represent F, Cl or straight-chain, branched or cyclic alkyl or alkenyl, each having up to 12 C atoms, Z Ｔ３ , Z Ｔ４ are the same or different and represent —CH═CH—, —CF═CF—, —CH═CF—, —CF═CH—, —C≡C—, or a single bond, and t is 0 or 1.

6. 6. A component comprising a liquid-crystalline medium according to any one of claims 1 to 5, wherein the liquid-crystalline medium is a polymer network liquid crystal comprising a polymer network obtainable from a liquid-crystalline medium according to any one of claims 1 to 5 by in situ polymerization, the liquid-crystalline medium further comprising one or more compounds of formula P 【Chemistry 23】 wherein the individual groups have the following meanings: P ａ , P ｂ each independently represents a polymerizable group, Sp ａ , Sp ｂ represents a spacer group, which may be the same or different in each occurrence; s1 and s2 each independently represent 0 or 1; A １ , A ２ each independently represents a group selected from the following group: a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene and 1,4'-bicyclohexylene, provided that in addition one or more non-adjacent CH ２ groups may be replaced by —O— and / or —S—, provided that in addition one or more H atoms may be replaced by F; b) the group consisting of 1,4-phenylene and 1,3-phenylene, wherein in addition one or two CH groups may be replaced by N, and in addition one or more H atoms may be replaced by L; c) the group consisting of tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobuta-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may be mono- or polysubstituted by L; d) polycyclic groups having 5 to 20 ring C atoms which may be saturated, partially unsaturated or fully unsaturated, but in addition one or more may be replaced by heteroatoms, preferably 【Chemistry 24】 selected from the group consisting of provided that one or more H atoms in these groups may be replaced by L, and / or one or more double bonds may be replaced by single bonds, and / or one or more CH groups may be replaced by N; n2 represents 0, 1, 2 or 3; Z ａ are in each occurrence independently of one another -CO-O-, -O-CO-, -CH ２ O-, -OCH ２ -, -CF ２ O-, -OCF ２ - or - (CH ２ ) ｎ -, where n is 2, 3, or 4, and -O-, -CO-, -C(R ｙ R ｚ ) -, -CH ２ CF ２ -, -CF ２ CF ２ represents - or a single bond, L may be the same or different in each occurrence and is selected from the group consisting of F, Cl, CN, SCN, SF ５ or alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, which may be linear or branched and in each case fluorinated, R ｙ , R ｚ each independently represent H, F or linear or branched alkyl having 1 to 12 C atoms, with the proviso that one or more H atoms may be replaced by F, M is -O-, -S-, or -CH ２ --, --CHY １ - or -CY １ Y ２ represents -, Y １ and Y ２ each independently represents H, F, or a straight-chain or branched alkyl having 1 to 12 C atoms (provided that one or more H atoms may be replaced by F), or represents Cl or CN.

7. Component comprising a liquid-crystalline medium according to any one of claims 1 to 6, wherein the liquid-crystalline medium comprises a chiral dopant.

8. 8. Component comprising a liquid-crystalline medium according to claim 1, wherein the liquid-crystalline medium comprises a stabilizer.

9. Component according to any one of claims 1 to 8, which is a transmissive spatial light modulator.

10. 9. The component of any one of claims 1 to 8, wherein the component is a reflective spatial light modulator (100) configured to modulate the phase of an incident optical signal propagating at least partially in a first dimension, wherein the first substrate is a transparent glass layer (110) having a first transparent electrode (120), and the second substrate is a CMOS silicon back substrate (160), and the component further comprises a mirror (150) disposed between the second substrate and the liquid crystal medium (140), the mirror being arranged and configured as the 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.

11. An LCoS device comprising a component according to claim 10.

12. 12. A device comprising the LCoS device of claim 11, wherein the device is a wavelength selective switch, a LIDAR scanner, an infrared scene projector, a wavelength division multiplexing system, a reconfigurable optical add-drop multiplexer, or an electro-evanescent photorefractive prism.

13. 1. A method for spatially modulating infrared 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 layer of a liquid-crystalline medium as defined in any one of claims 1 to 8 sandwiched between the first and second substrates; 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 layer of liquid crystal medium; A method comprising:

14. 1. A method of manufacturing an optical phase modulator, comprising: 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 any one of claims 1 to 8 on a first substrate; c) mounting a second substrate having a second electrode on the liquid crystal material; The method includes at least the following.

15. Liquid-crystalline medium as defined in any one of claims 1 to 8.

Images