Liquid crystal medium

Abstract

The present invention relates to liquid crystal (LC) media or LC materials and to energy-saving liquid crystal displays (LCDs) containing these media, in particular to game displays and AR / VR headsets addressed by active matrices and in particular to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilized SA-HB-FFS, polymer stabilized SA-XB-FFS, positive VA or positive PS-VA type.

Description

Technical Field

[0001] The present invention relates to liquid crystal (LC) media and to energy-efficient liquid crystal displays (LCDs) containing these media, in particular to high-contrast gaming displays and AR / VR headsets addressed by an active matrix and in particular to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer-stabilized SA-HB-FFS, polymer-stabilized SA-XB-FFS, positive VA or positive PS-VA type. In a preferred embodiment, the LC medium has a positive dielectric anisotropy. Background Art

[0002] Liquid crystal displays (LCDs) are used in many fields for information display. LCDs are used for both direct view and projection displays. Electro-optical modes used are, for example, twisted nematic (TN), super twisted nematic (STN), optically compensated bend (OCB) and electrically controlled birefringence (ECB) modes and their various variations, as well as other modes. All of these modes utilize an electric field generated substantially perpendicular to the substrate and the LC layer.

[0003] In addition to these modes, there are also electro-optical modes, which utilize an electric field substantially parallel to the substrate or LC layer. For example, WO 91 / 10936 discloses LC displays in which the electric signal is generated in such a way that the electric field has a significant component parallel to the LC layer, and which have since been known as "in-plane switching" (IPS) displays. The principle of operating such displays is described, for example, by RA Soref in Journal of Applied Physics, Vol. 45, No. 12, pp. 5466-5468 (1974).

[0004] IPS displays contain an LC layer between two substrates with a planar orientation, wherein the two electrodes are arranged on only one of the two substrates and preferably have an interdigitated comb structure. When a voltage is applied to the electrodes, an electric field with a significant component parallel to the LC layer is generated between them. This leads to a realignment of the LC molecules in the layer plane.

[0005] For example, EP 0 588 568 discloses various possibilities for designing electrodes and for addressing IPS displays. DE 198 24 137 likewise describes various embodiments of such IPS displays.

[0006] Liquid-crystal materials for IPS displays of this type are described, for example, in DE 195 28 104.

[0007] Furthermore, so-called "fringe field switching" (FFS) displays have been reported (see in particular SH Jung et al., Jpn. J. Appl. Phys. [Japanese Journal of Applied Physics], Vol. 43, No. 3, 2004, 1028), which contain two electrodes on the same substrate, one of which is structured in a comb-like manner and the other is unstructured. This results in strong so-called "fringe fields", i.e. strong electric fields close to the edges of the electrodes, and in the entire cell, electric fields with both a strong vertical component and also a strong horizontal component. FFS displays have a low viewing angle dependence of the contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy and an alignment layer, usually a polyimide, which provides a planar alignment for the molecules of the LC medium.

[0008] Liquid crystal displays in the IPS and FFS electro-optical modes are particularly suitable for use in modern desktop monitors, television sets and multimedia applications. The LC media according to the invention are preferably used in displays of this type. Usually, dielectrically positive LC media with rather low dielectric anisotropy values ​​are used in FFS displays, but in some cases LC media with dielectric anisotropy values ​​of only about 3 or even lower are also used in IPS displays.

[0009] Further improvements have been achieved through the HB-FFS mode. One of the unique features of the HB-FFS mode is its ability to achieve higher transmittance compared to conventional FFS technology, which allows the panel to be operated with less energy consumption.

[0010] Another recently developed mode is the XB-FFS mode, in which the LC medium additionally contains polar liquid crystal compounds having low dielectric anisotropy.

[0011] Liquid crystal compositions suitable for LCDs and in particular for FFS and IPS displays are known in the prior art, for example, from JP 07-181 439 (A), EP 0 667 555, EP 0 673 986, DE 195 09 410, DE 195 28106 and DE 195 28 107. However, these compositions have certain disadvantages. Among other drawbacks, most of them result in disadvantageously long addressing times, have insufficient resistivity values ​​and / or require excessively high operating voltages. Improvements in both operating characteristics and also in shelf life are necessary here.

[0012] FFS and IPS displays can be operated as active matrix displays (AMD) or passive matrix displays (PMD). In the case of active matrix displays, the individual pixels are usually addressed by integrated, non-linear active elements such as, for example, thin film transistors (TFTs), while in the case of passive matrix displays, the individual pixels are usually addressed by multiplexing methods as are known from the prior art.

[0013] The displays according to the invention are preferably addressed by an active matrix, preferably by a matrix of TFTs. However, the LC media according to the invention can also be advantageously used in displays having other known addressing means.

[0014] Typical applications of IPS and FFS technologies are monitors, laptops, TVs, mobile phones, tablets, etc. Both IPS and FFS technologies have certain advantages over other LCD technologies, like for example Vertical Alignment (VA) technology, such as wide viewing angle dependency of contrast ratio.

[0015] The provision of further LC media and their use in displays with high transmittance, a good black state and a high contrast ratio are central challenges for modern FFS and IPS applications. In addition, modern applications also require good low temperature stability and fast addressing times.

[0016] Until now, it has not been possible to design materials with high contrast, such as high elastic constants K1 and K av Suitable LC media with low switching speeds, low temperature stability and low response times are still needed. Therefore, the overall image quality in such devices still needs further improvement. In particular, in the field of gaming applications, other parameters related to image quality are often sacrificed in order to achieve fast switching speeds. Summary of the invention

[0017] The object of the present invention is to provide LC media, in particular for energy-saving gaming FFS and IPS displays and AR / VR headsets, but also for TN, positive VA or STN displays, and in particular for active-matrix displays, like those addressed by TFT, which have a high average elastic constant K av In combination with a low response time parameter (γ1 / K1) and low rotational viscosity and a relatively low birefringence Δn. In addition, they need to have high specific resistance, low threshold voltage, high dielectric anisotropy, good low temperature stability (LTS), fast response time and be able to achieve high brightness. In the case of FFS displays, further optimization of response time, contrast, brightness and reliability is required. However, it is found that the LC materials of the prior art generally cannot meet all these requirements simultaneously.

[0018] Surprisingly, the above technical problem has been solved by providing the LC media described and claimed hereinafter.

[0019] It has now surprisingly been found that the LC media according to the invention which comprise a combination of compounds of the formulae G and U

[0020]

[0021] wherein each substituent is as specified in claim 1,

[0022] shows several significant improvements, especially when used in FFS mode displays, such as a high average elastic constant K av , a combination of a low response time parameter (γ1 / K1) with a low rotational viscosity and good solubility, and enables fast response times. Compounds of the formulae G and U are already known per se in the prior art.

[0023] Furthermore, the LC media according to the invention have high definition bright spots, excellent low temperature stability (LTS) and offer optimum motion picture quality and improved overall image quality, in particular high contrast.

[0024] The present invention relates to an LC medium, characterised in that it comprises one or more compounds of formula G

[0025]

[0026] and one or more compounds having formula U

[0027]

[0028] where the individual substituents have the following meanings, identically or differently on each occurrence and independently of one another:

[0029] R 1 , R 4 Each independently represents a H atom, a halogen atom

[0030] and R 5 , -CN, -SCN, -NCS, alkyl or alkoxy having 1 to 12 C atoms or alkenyl or alkenyloxy having 2 to 12 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms may be replaced by halogen atoms, or cycloalkyl or cycloalkoxy having 3 to 12 C atoms, in which one or more H atoms may be replaced by halogen atoms;

[0031] R 2Alkyl or alkoxy having 1 to 12 C atoms or alkenyl or alkenyloxy having 2 to 12 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms may be replaced by a cycloalkyl or cycloalkoxy group having 3 to 12 C atoms;

[0032] R 3 and R 6 each independently of one another represents an H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms, wherein one or more non-adjacent CH2 groups are optionally substituted by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another;

[0033] A 1 , A 2 , each independently represents a phenylene-1,4-diyl group,

[0034] A 3 and A 4 wherein, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3, cyclohexane-1,4-diyl, wherein, in addition, one or two non-adjacent CH2 groups may be replaced independently of one another by O and / or S and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-diol. Alkane-2,5-diyl;

[0035] Z 1 , Z 2 , each independently represents -CF2O-, -OCF2-,

[0036] Z 3 and Z 4-CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-, -C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFH CH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or single bond;

[0037] k, l, m, and n each independently represent 0, 1, 2, or 3.

[0038] The LC media according to the invention are particularly suitable for energy-saving LC displays for gaming and AR / VR headsets in FFS, HB-FFS, XB-FFS and IPS modes based on dielectrically positive liquid crystals and their polymer-stabilized variants.

[0039] The invention further relates to the use of LC media as described above and below for electro-optical purposes, in particular in LC displays, shutter glasses, LC windows, 3D applications, preferably in TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FFS, polymer-stabilized SA-HB-FFS, polymer-stabilized SA-XB-FFS, positive VA and positive PS-VA displays, very preferably in FFS, HB-FFS, IPS, PS-HB-FFS and PS-IPS displays.

[0040] The invention further relates to an electro-optical LC display comprising an LC medium as described above and below, in particular a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FFS, polymer-stabilized SA-HB-FFS, polymer-stabilized SA-XB-FFS, positive VA or positive PS-VA display, preferably a FFS, HB-FFS, IPS, PS-HB-FFS or PS-IPS display.

[0041] In the present application, all atoms also include their isotopes. In some embodiments, one or more hydrogen atoms (H) may be optionally replaced by deuterium (D); a high degree of deuteration enables or simplifies analytical determination of compounds, especially at low concentrations.

[0042] In formulas G and U, if R 1 , R 2, R 3 , R 4 , R 5 or R 6 R represents alkyl and / or alkoxy, which may be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 5 or 6 C atoms, and preferably represents ethyl, propyl, butyl, pentyl, hexyl, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy, furthermore methyl, methoxy. 0 Preferably it represents straight-chain alkyl having 1 to 6 C atoms or alkenyl having 2 to 6 C atoms.

[0043] Oxaalkyl preferably denotes straight-chain 2-oxapropyl (=methoxymethyl), 2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl.

[0044] If R 1 , R 2 , R 3 , R 4 , R 5 or R 6 If an alkoxy group or an oxaalkyl group is represented, it may also contain one or more further oxygen atoms, provided that the oxygen atoms are not directly bonded to one another.

[0045] In another preferred embodiment, R 1 , R 2 , R 4 or R 5 One or more selected from -S 1 -F, -OS 1 -F, -O-S1-O-S2, where S 1 It is C 1-12 -alkylene or C 2-12 -alkenylene, and S 2 It is H, C 1-12 -alkyl or C 2-12 -alkenyl, and very preferably R 1 , R 2 , R 4 or R 5 One or more selected from A group consisting of -OCH2OCH3, -O(CH2)2OCH3, -O(CH2)3OCH3, -O(CH2)4OCH3, -O(CH2)2F, -O(CH2)3F, and -O(CH2)4F.

[0046] If R 1 , R 2 , R 3 , R 4 , R 5 or R 6 denotes alkenyl, which may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Thus, it particularly denotes vinyl, prop-1-enyl or prop-2-enyl, but-1-enyl, but-2-enyl or but-3-enyl, pent-1-enyl, pent-2-enyl, pent-3-enyl or pent-4-enyl, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl or hex-5-enyl, hept-1-enyl, hept-2-enyl, hept-3-enyl, hept-4-enyl, hept-5-enyl or hept-6-enyl, oct-1-enyl, Oct-2-enyl, oct-3-enyl, oct-4-enyl, oct-5-enyl, oct-6-enyl or oct-7-enyl, non-1-enyl, non-2-enyl, non-3-enyl, non-4-enyl, non-5-enyl, non-6-enyl, non-7-enyl or non-8-enyl, dec-1-enyl, dec-2-enyl, dec-3-enyl, dec-4-enyl, dec-5-enyl, dec-6-enyl, dec-7-enyl, dec-8-enyl or dec-9-enyl.

[0047] If R 1 , R 2 , R 3 , R 4 , R 5 or R 6 If alkyl or alkenyl is at least monosubstituted by halogen, the radical is preferably straight-chain and halogen is preferably F or Cl. In the case of polysubstitution, halogen is preferably F. The resulting radicals also include perfluorinated radicals. In the case of monosubstitution, the fluorine or chlorine substituent can be in any desired position, but is preferably in the ω-position.

[0048] A in formula G 1 and A 2 And A in formula U 3 and A 4 Particularly preferably, it represents phenylene-1,4-diyl, which may also be mono- or polysubstituted by F, and furthermore cyclohexane-1,4-diyl, cyclohexene-1,4-diyl, tetrahydropyran-2,5-diyl or 1,3-dihydropyran-1,4-diyl. Alkane-2,5-diyl.

[0049] A in formula G and U 1 and A 3 Particularly preferably,

[0050]

[0051] Where L 1 and L 2 represents halogen, CF3 or CN, preferably F;

[0052] A 1 and A 3 Unsubstituted 1,4-phenylene is preferred.

[0053] Z in formula G 1 and Z 2 And Z in formula U 3 and Z 4 Particularly preferably it represents -CF2O-, -OCF2- or a single bond, wherein a single bond is most preferred.

[0054] Furthermore, preference is given to compounds of the formula G and U, wherein R 1 , R 4 and R 5 Each independently of one another represents H or alkyl, alkenyl or alkynyl having up to 8, preferably up to 5, C atoms, each of which is optionally substituted by halogen, in particular by F.

[0055] Particularly preferred radicals R in formulae G and U are 1 , R 4 and R 5 represents an alkyl, alkenyl, alkynyl or alkoxy radical having up to 12, preferably up to 8, C atoms, each of which is optionally substituted by halogen, in particular by F, particularly preferably H, F, an alkyl, alkenyl or alkynyl radical having up to 8 C atoms. Preferably, the radical R 1 and R 2 and R 4 and R 5 At least one of them is not H, particularly preferably a group R 1 , R 2 , R 4 and R 5 None of them is represented by an H atom. 1 and R 4 Very particularly preferably, R is equal to alkyl. 1 and R 4 is an alkyl group. 1 , R 2 , R 4 and R 5 each independently of one another very particularly preferably represents an unbranched alkyl radical having 1 to 5 C atoms. 1 , R 2 , R 4 and R 5 represents a substituted alkyl, alkoxy, alkenyl or alkynyl group, then the two groups R 1 and R2 Or, R 4 and R 5 The total number of C atoms in each case is preferably less than 10.

[0056] Preferred groups R in formula G and U are 3 and R 6 represents an H atom or an alkyl or alkenyl group having up to 3 C atoms. Very particularly preferably, R 3 and R 6 is a methyl group or a H atom.

[0057] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl and n-octyl.

[0058] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl and pentenyl.

[0059] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl and octynyl.

[0060] Preferred alkoxy groups are, for example, methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy, n-heptyloxy, n-octyloxy.

[0061] Halogen preferably represents F or Cl, F being most preferred.

[0062] Particularly preferred compounds of formula G and U are those selected from the following sub-formulae:

[0063]

[0064]

[0065]

[0066]

[0067] Where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 has the meaning indicated in the general formulae G and U. In a particularly preferred embodiment, the compounds of formulae G and U are selected from structures G-1 and U-1, wherein the combination of compounds described by formulae G-1 and U-1 is most preferred.

[0068] Particularly preferred compounds of the general formula G and U are as follows:

[0069]

[0070]

[0071]

[0072]

[0073] wherein n and m each independently represent 0, 1, 2, 3, 4, 5, 6, 7, 9, 10, 11 or 12.

[0074] Most preferred compounds of formula G include in particular one or more of the following:

[0075]

[0076]

[0077]

[0078] In a further preferred embodiment, the following compounds having formula G may be used:

[0079]

[0080]

[0081]

[0082] In another preferred embodiment, the following compounds having formula U may be used:

[0083]

[0084]

[0085]

[0086]

[0087] Compounds of the formula G and U can be prepared analogously to methods known to the person skilled in the art and described in standard works of organic chemistry such as, for example, Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart.

[0088] The proportion of compounds of formula G (or preferably subformula G-1-1 thereof) in the LC medium is GPreferably it is from 0.5 to 20% by weight, very preferably from 1 to 15%, most preferably from 2 to 10%. The proportion of the compound of formula U (or preferably its subformula U-1-1) in the LC medium is ω U Preferably from 0.5 to 20% by weight, very preferably from 1 to 15%, most preferably from 2 to 10%. Furthermore, the proportion of compounds of formula G in the LC medium is G Typically higher than the proportion ω of the compound of formula U in the LC medium U In a particularly preferred embodiment, ω G ≥1.5*ω U , even more preferably, ω G ≥2.0*ω U The cumulative ratio of compounds of formula G and U in the LC medium (ω G +ω U ) is preferably from 2.0 to 30% by weight, very preferably from 2 to 30%, most preferably from 5 to 20%.

[0089] Additional components

[0090] In a preferred embodiment, the LC medium may additionally comprise one or more compounds selected from the following formulae II and III:

[0091]

[0092] where the individual substituents, independently of one another and identically or differently on each occurrence, have the following meanings:

[0093]

[0094]

[0095] R 0 For R in formula G 1 One of the meanings given,

[0096] X 0 independently of one another represent F, Cl, haloalkyl, haloalkenyl, haloalkoxy or haloalkenyloxy having up to 6 C atoms,

[0097] L 1-8 independently of each other H, F or Cl, and

[0098] Y 0 H or CH3.

[0099] Preferred compounds of formula II and III are those wherein Y 0 Those are H.

[0100] Further preferred compounds of formula II and III are those wherein R 0 represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 Those representing F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably those representing F.

[0101] In a preferred embodiment, the LC medium comprises one or more compounds of formula II selected from the following subformulae:

[0102]

[0103]

[0104] Where R 0 and X 0 has the meaning given in formula II.

[0105] Preferred compounds are those of the formulae II-1, II-2 and II-3, very preferred are those of the formulae II-1 and II-2.

[0106] In the compounds having formulae II-1 to II-7, R 0 preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 It represents F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably F.

[0107] In one embodiment, the LC medium contains one or more compounds of formula II or its subformulae as described above and below, wherein Y 0 is CH3. Very preferably, the LC medium according to this preferred embodiment comprises one or more compounds of formula II selected from the following subformulae:

[0108]

[0109]

[0110] Where R 0 and X 0 has the meaning given in formula II.

[0111] Preferred compounds are those of formula IIA-1, IIA-2 and IIA-3, very preferred are those of formula IIA-1 and IIA-2.

[0112] In the compounds of Formulae IIA-1 to IIA-7, R 0 preferably denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 It represents F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably F.

[0113] The proportion of the compound of formula II in the LC medium is typically from 0 to 20% by weight, very preferably from 1 to 15%, most preferably from 2 to 10% by weight.

[0114] In a further preferred embodiment, the LC medium comprises one or more compounds of formula III selected from the following subformulae:

[0115]

[0116]

[0117]

[0118]

[0119] Where R 0 and X 0 has the meaning given in formula II.

[0120] Preferred compounds are those of formula III-1, III-4, III-6, III-16, III-19 and III-20.

[0121] In the compounds of formulae III-1 to III-21, R 0 represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 represents F, CF3 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F, and Y 0 Preferably it represents H.

[0122] The LC medium may contain one or more compounds of formula III or its subformulae as described above and below, wherein Y 0 is CH3. Very preferably, the medium according to this preferred embodiment comprises one or more compounds of formula III selected from the following subformulae:

[0123]

[0124]

[0125]

[0126]

[0127] Where R 0 and X 0 has the meaning given in formula III.

[0128] Preferred compounds are those having Formula IIIA-1, IIIA-4, IIIA-6, IIIA-16, IIIA-19 and IIIA-20.

[0129] In the compounds of Formulae IIIA-1 to IIIA-21, R 0 represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 It represents F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably F.

[0130] The proportion of the compound of the formula III in the LC medium is preferably from 5 to 60% by weight, very preferably from 10 to 50%, most preferably from 20 to 40%.

[0131] In a further preferred embodiment, the LC medium may additionally comprise one or more compounds selected from the following formulae:

[0132]

[0133]

[0134] in

[0135] R 0 , X 0 , L 1-4 and Y 0 has the meaning indicated in formula II and III,

[0136] Z 0 represents -C2H4-, -(CH2)4-, -CH=CH-, -CF=CF-, -C2F4-, -CH2CF2-, -CF2CH2-, -CH2O-, -OCH2-, -COO-, -CF2O- or -OCF2-, and in formulas V and VI also represents a single bond; and

[0137] s represents 0 or 1.

[0138] The compound of formula IV is preferably selected from the following formulae:

[0139]

[0140]

[0141] Where R 0 and X 0 has the meaning indicated in formulae II and III.

[0142] R 0 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably it represents F or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl.

[0143] The compound of formula IVa is preferably represented by the following sub-formula:

[0144]

[0145] The compound having formula IVb is preferably represented by the following formula:

[0146]

[0147] The compound of formula IVc is preferably represented by the following sub-formula:

[0148]

[0149] Where R 0 has the meanings indicated in formula II and is preferably alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl.

[0150] One or more compounds of the formula IVc, in particular of the formula IVc-1, are preferably used in the LC media according to the invention in an amount of 1% to 20% by weight, particularly preferably 2% to 15% by weight.

[0151] The compound of formula V is preferably selected from the following sub-formulae:

[0152]

[0153]

[0154] Where R 0 and X 0 has the meaning indicated in formula II.

[0155] R 0Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably, F and OCF3 are represented, furthermore OCHF2, CF3, OCF=CF2, OCHFCF3 and OCH=CF2.

[0156] The compound of formula VI is preferably selected from the following sub-formulae:

[0157]

[0158] Where R 0 and X 0 has the meaning indicated in formula II.

[0159] R 0 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably represents F, furthermore OCF3, CF3, CF=CF2, OCHF2, OCHFCF3 and OCH=CF2;

[0160] The compound of formula VII is preferably selected from the following sub-formulae:

[0161]

[0162] Where R 0 and X 0 has the meaning indicated in formula II.

[0163] R 0 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably it represents F, furthermore OCF3, OCHF2, OCHFCF3 and OCH═CF2.

[0164] In some embodiments, the LC medium further comprises one or more compounds selected from the following formulae:

[0165]

[0166]

[0167] in

[0168] R 0 and X 0 each independently of one another has one of the meanings indicated in formula II,

[0169] L 1-4Each independently represents H or F,

[0170] Y 0 represents H or CH3, preferably H,

[0171] X 0 Preferably F, Cl, CF3, OCF3 or OCHF2, OCF=CF2, OCHFCF3

[0172] R 0 Preferably it denotes alkyl, alkoxy, oxaalkyl, cycloalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0173] Very preferably, the LC media according to the invention comprise one or more compounds of the formula XXa:

[0174]

[0175] Where R 0 represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl, and X 0 R represents F, CF3 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F. 0 Preferably it denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0176] One or more compounds of the formula XX, in particular of the formula XXa, are preferably used in the LC media according to the invention in an amount of 0% to 15% by weight, particularly preferably 1% to 10% by weight.

[0177] Very preferably, the LC media according to the invention comprise one or more compounds of the formula XXIa:

[0178]

[0179] Where R 0 R represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably it denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl.

[0180] One or more compounds of the formula XXI, in particular of the formula XXIa, are preferably used in the LC media according to the invention in an amount of 1% to 15% by weight, particularly preferably 2% to 10% by weight.

[0181] Further preferably, the LC media according to the invention comprise one or more compounds of the formula XXIIIa:

[0182]

[0183] Where R 0 represents an alkyl group having 1 to 6 C atoms or a cycloalkyl group having 3 to 6 C atoms. 0 Preferably it denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl and very particularly preferably n-propyl or cycloalkyl, in particular cyclopentyl.

[0184] Preferred specific compounds of formula XXIIIa include in particular

[0185]

[0186] One or more compounds of the formula XXIII, in particular of the formula XXIIIa, are preferably used in the LC media according to the invention in an amount of 0.5% to 5% by weight, particularly preferably 0.5% to 2% by weight.

[0187] The LC medium may additionally comprise one or more compounds of the formula XXIV:

[0188]

[0189] Where R 0 , X 0 and L 1-6 has the meaning indicated in formula III, s represents 0 or 1, and

[0190] express

[0191] In Formula XXIV, X 0 It may also represent an alkyl radical having 1 to 6 C atoms or an alkoxy radical having 1 to 6 C atoms. The alkyl or alkoxy radical is preferably straight-chain.

[0192] R 0 Preferably, X represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F;

[0193] The compound of formula XXIV is preferably selected from the following sub-formulae:

[0194]

[0195]

[0196] Where R 0 , X 0and L 1 has the meaning indicated in formula III. 0 Preferably, X represents an alkyl radical having 1 to 6 C atoms. 0 Preferably, F is represented, and L 1 Preferably F;

[0197] Preferably

[0198]

[0199] R 0 is a straight-chain alkyl or alkenyl group having 2 to 6 C atoms;

[0200] The LC medium may further comprise one or more compounds of the following formula:

[0201]

[0202] Where R 1 and X 0 Respectively have in formula II for R 0 and X 0 The meaning indicated. 1 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0 Preferably represents F, CF3 or OCF3, furthermore OCF=CF2, OCHFCF3 or Cl, very preferably F. In formula XXIV, X 0 Very particularly preferably it represents Cl.

[0203] The LC medium may further optionally comprise one or more compounds of the following formula:

[0204]

[0205] in

[0206]

[0207] And R 1 , X 0 and Y 0 Respectively have in formula II for R 0 , X 0 and Y 0 The meaning indicated. 1 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0Preferably represents F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably F, and Y 0 Preferably represents H. The LC media according to the invention particularly preferably comprise one or more compounds of the formula XXIX, in which X 0 Preferably it represents F.

[0208] One or more compounds of the formulae XXVII-XXX are preferably used in the LC media according to the invention in an amount of 1% to 20% by weight, particularly preferably 1% to 15% by weight. Particularly preferred LC media comprise at least one compound of the formulae XXIX and / or XXX.

[0209] Very preferably, the LC media according to the invention comprise one or more compounds of the formula XXIXa or XXXa:

[0210]

[0211] Where R 1 and Y 0 With formula II, for R 0 and Y 0 The indicated meaning, and preferably R 1 denotes alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl.

[0212] One or more compounds of the formula XXIXa and / or XXXa are preferably used in the LC media according to the invention in an amount of 1% to 15% by weight, particularly preferably 2% to 10% by weight.

[0213] The LC medium may further comprise one or more of the following pyrimidine or pyridine compounds having the following formula:

[0214]

[0215]

[0216] Where R 1 , X 0 and Y 0 Respectively have in formula II for R 0 , X 0 and Y 0 The meaning indicated. 1 Preferably represents alkyl having 1 to 6 C atoms or cycloalkyl having 3 to 6 C atoms, very preferably ethyl, propyl, butyl or pentyl. 0Preferably represents F, CF3 or OCF3, furthermore OCF═CF2, OCHFCF3 or Cl, very preferably F, and Y 0 Preferably represents H. The medium according to the invention may in particular optionally comprise one or more compounds of the formula XXXI-1, in which X 0 Preferably it denotes F. One or more compounds of the formulae XXXI-1 to XXXI-3 can be used in the LC media according to the invention in an amount of 1% to 20% by weight, particularly preferably 1% to 15% by weight.

[0217] Preferably, the LC medium contains, in addition to compounds of formulae G and U and optionally II and / or III, one or more compounds selected from the following formulae:

[0218]

[0219]

[0220] in

[0221] "Alkyl" and "alkyl*" each independently represent an alkyl group having 1 to 6 C atoms;

[0222] “Alkenyl” and “alkenyl*” each independently of one another denote an alkenyl radical having 2 to 6 C atoms.

[0223] Very preferred are compounds of the formula Z1 and Z2.

[0224] Preferred compounds of formula Z1 to Z6 are those selected from the following sub-formulae:

[0225]

[0226]

[0227]

[0228]

[0229] In another preferred embodiment, the LC medium contains one or more compounds of formula Z1 or preferred subformulae thereof and / or one or more compounds selected from formulae Z2, Z3, Z4 and Z5 or preferred subformulae thereof.

[0230] Preferably, the total proportion of compounds of formula Z1, Z2, Z3, Z4, Z5 and Z6 or subformulae thereof, such as CC-3-V, in the medium is from 10 to 65% by weight, very preferably from 20 to 60%, most preferably from 25 to 55%. In a further preferred embodiment, the compound of formula Z1-1 is used in a concentration ranging from 10 to 60 wt.-%, more preferably from 25 to 50 wt.-%, based on the total weight of the LC medium. In a further preferred embodiment, the LC medium comprises a total of 50 to 70 wt.-% of compounds represented by formulae Z1-1 and Z4-2.

[0231] Preferably, the medium contains 1, 2 or 3 compounds selected from the group consisting of formulae Z1, Z2, Z3 and Z4 or subformulae thereof.

[0232] The LC medium may additionally comprise one or more compounds of the following general formula:

[0233]

[0234] in

[0235] R 1 and R 2 Each independently represents C 1-6 -alkyl, C 1-6 -alkoxy or C 2-6 -alkenyl.

[0236] The compound of formula XII is preferably selected from the following sub-formulae:

[0237]

[0238] Here, "alkyl" and "alkyl*" each independently represent methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0239] Particularly preferred are compounds of formulae XIIa and XIIc. In formula XIIb, "alkyl" preferably represents, independently of one another, n-C3H7, n-C4H9 or n-C5H 11 , especially n-C3H7. In formula XIIc, "alkyl" preferably represents n-C3H7 and "alkyl*" is preferably CH3 or n-C3H7.

[0240] Particularly preferred compounds having Formula XII are described by the following structure:

[0241]

[0242] The LC medium may additionally comprise one or more compounds selected from the following formulae:

[0243]

[0244] Where L 1 and L 2 has the meaning indicated in Formula III, and R 1 and R 2 each independently of one another represents n-alkyl, cycloalkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, and preferably each independently of one another represents alkyl having 1 to 6 C atoms; in the compounds of formula XIV, the substituent R 1 and R 2 At least one of preferably represents an alkenyl group having 2 to 6 C atoms.

[0245] The LC medium may further optionally contain one or more compounds of formula XIV, wherein the substituent R 1 and R 2 At least one of represents an alkenyl group having 2 to 6 C atoms, preferably selected from those of the following sub-formulae:

[0246]

[0247]

[0248] Therein, "alkyl" and "alkyl*" have the meanings indicated above and each independently of one another preferably denotes methyl, ethyl or propyl.

[0249] The compound of formula XIV is preferably selected from the following sub-formulae:

[0250]

[0251] Very preferred are compounds of formula XIVd-1, XIVe-1, XIVe-2 and XIVe-3.

[0252] The LC medium may further optionally contain one or more compounds of formula XV, wherein the substituent R 1 and R 2 At least one of represents an alkyl or alkoxy group having 2 to 6 C atoms, preferably selected from those of the following sub-formulae:

[0253]

[0254] Therein, "alkyl" and "alkyl*" have the meanings indicated above and each independently of one another preferably denotes methyl, ethyl or propyl.

[0255] In yet further embodiments, the LC medium comprises one or more compounds of formula XVI:

[0256]

[0257] Where R 1 and R 2 In Formula II, for R 0 The indicated meanings and preferably each independently of one another denote alkyl having 1 to 6 C atoms. L denotes H or F.

[0258] Particularly preferred compounds of formula XVI are those having the following sub-formula:

[0259]

[0260]

[0261] in

[0262] "Alkyl" and "alkyl*" each independently of one another denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0263] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH2═CHC2H4, CH3CH═CHC2H4, CH2═CH and CH3CH═CH.

[0264] Particularly preferred are compounds of the formulae XVIb and XVIc. Very particularly preferred are compounds of the following subformulae:

[0265]

[0266]

[0267] In yet further embodiments, the LC medium comprises one or more compounds having formula XIII:

[0268]

[0269] Where R 1 and R 2 With respect to R in Formula II 0 The indicated meanings and preferably each independently of one another denote an alkyl group having 1 to 6 C atoms. L denotes H, F or Cl.

[0270] Particularly preferred compounds of formula XIII are those having the following sub-formula:

[0271]

[0272]

[0273] in

[0274] "Alkyl" and "alkyl*" each independently of one another denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0275] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH2═CHC2H4, CH3CH═CHC2H4, CH2═CH and CH3CH═CH.

[0276] Particularly preferred are compounds of the formulae XIIIa and XIIIb. Very particularly preferred are compounds of the following sub-formulae:

[0277]

[0278]

[0279] In yet further embodiments, the LC medium comprises one or more compounds having formula XIII':

[0280]

[0281] Where R 1 and R 2 With respect to R in Formula II 0 The indicated meanings and preferably each independently of one another denote an alkyl group having 1 to 6 C atoms. L denotes H, F or Cl.

[0282] Particularly preferred compounds of formula XIII' are those having the following sub-formula:

[0283]

[0284] in

[0285] "Alkyl" and "alkyl*" each independently of one another denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0286] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH2═CHC2H4, CH3CH═CHC2H4, CH2═CH and CH3CH═CH.

[0287] Particularly preferred are compounds of the formula XIII'a and XIII'b. Very particularly preferred are compounds of the following sub-formula:

[0288]

[0289] The LC medium may optionally comprise one or more compounds of the following formula:

[0290]

[0291] in

[0292] R 1 and R 2 have the meanings indicated in formula G and preferably each independently of one another denote an alkyl group having 1 to 6 C atoms. L denotes H or F.

[0293] Very preferred are compounds of formula XVIIa, wherein L is H or F. Very preferred are compounds of formula XVIIb, wherein L is F.

[0294] The LC medium may additionally comprise one or more compounds of the following formula:

[0295]

[0296] Among them, L, R 1 and R 2 In formula LP1, respectively, 1 And in formula U for R 4 and R 5 The meaning indicated. 1 and R 2 Preferably it denotes alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0297] Particularly preferred compounds of formula XXXII are those having the following sub-formula:

[0298]

[0299] in

[0300] "Alkyl" and "alkyl*" each independently of one another denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0301] "Alkenyl" denotes straight-chain alkenyl groups having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4, CH2=CH and CH3CH=CH.

[0302] Very particular preference is given to compounds of the following sub-formula:

[0303]

[0304] In some further embodiments, the LC medium comprises one or more compounds having the following formula:

[0305]

[0306] Where R 1 and R 2 have the meanings indicated in formula G and preferably each independently of one another represent an alkyl group having 1 to 6 C atoms.

[0307] Advantageously, the LC media of the invention comprise one or more compounds of the formulae LP1 and LP2

[0308]

[0309] The substituents have the following meanings:

[0310] R 0 With respect to R in formula G and U 1 , R 4 and R 5 One of the meanings given;

[0311] R 2 In formula U, for R 2 One of the meanings given;

[0312] L 1 and L 2 Each independently represents H, F or Cl;

[0313] Y 0 With formula U and G for R 3 and R 6 One of the meanings given, preferably H or CH3;

[0314] X 0 represents a halogen atom, CN, SCN, NCS or an alkyl or alkoxy group having 1 to 6 C atoms or an alkenyl or alkenyloxy group having 2 to 6 C atoms, in which one or more H atoms are replaced by F atoms.

[0315] The one or more compounds having formula LP1 and LP2 may preferably be described by the following formulas LP1-1 and LP2-1:

[0316]

[0317] in

[0318] R 0 is an alkyl or alkoxy radical having 1 to 6 C atoms or an alkenyl radical having 2 to 6 C atoms, wherein one or more CH2 radicals are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly attached to one another and wherein one or more H atoms may be replaced by a halogen atom;

[0319] R 2 is an alkyl radical having 1 to 6 C atoms, wherein one or more CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-,

[0320] -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly attached to one another and wherein one or more H atoms may be replaced by a halogen atom;

[0321] X 0 F atoms or alkyl or alkoxy having 1 to 3 C atoms or alkenyl or alkenyloxy having 2 or 3 C atoms, wherein one or more H atoms are replaced by F atoms, and

[0322] Y 0 H or CH3.

[0323] Compounds having the general formula LP1 and LP2 may also be represented by one of the following:

[0324]

[0325]

[0326] in

[0327] R 0 is an alkyl or alkoxy radical having 1 to 12 C atoms, wherein one or more CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms may be replaced by halogen atoms, preferably alkyl having 1 to 4 C atoms, alkenyl or alkenyloxy having 2 to 6 C atoms or cycloalkyl or cycloalkoxy having 3 to 6 C atoms, with vinyl, allyl or cyclopentyl being particularly preferred;

[0328] n represents 1, 2, 3, 4, or 5; and

[0329] m means 1, 2, 3, or 4.

[0330] Particularly preferred compounds of formula LP1 are those selected from the group consisting of the following subformulae:

[0331]

[0332]

[0333]

[0334] where Y 0 It is H or CH3, preferably H.

[0335] Very preferred are compounds of formula LP1-1a, LP1-1b and LP1-1c, most preferred are compounds of formula LP1-1a.

[0336] Particularly preferred compounds of formula LP2 are those selected from the group consisting of the following subformulae:

[0337]

[0338]

[0339]

[0340] where Y 0 It is H or CH3, preferably H.

[0341] Very preferred are compounds of formula LP2-1a, LP2-1b, LP2-1c, LP2-1d and LP2-1i, LP2-2b, LP2-3a, LP2-3c, most preferred are compounds of formula LP2-1b.

[0342] The total proportion of compounds of formula LP1 or LP2 or subformulae thereof in the LC medium is preferably from 2 to 35%, very preferably from 3 to 30%, most preferably from 4 to 20% by weight.

[0343] Preferably, the LC medium contains 1, 2 or 3 compounds of formula LP1 or LP2 or subformulae thereof. In a particularly preferred embodiment, the LC medium comprises at least one compound of formula LP1 and at least one compound of formula LP2.

[0344] In addition to compounds of formula G, U, Z1 to Z12, II and / or III, the LC medium may optionally also contain one or more compounds selected from the group consisting of formulae Y and B:

[0345]

[0346] where the individual substituents have the following meanings, identically or differently on each occurrence and independently of one another:

[0347]

[0348] in

[0349] R 1 , R 2 In formula G, for R 1 and R 2 One of the meanings given,

[0350] R 3 For R 1 One of the meanings given,

[0351] Z x , Z y -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O-, or a single bond, preferably a single bond,

[0352] Z z -CH2O-, -O-, -C2H4-, -OCH2-, or a single bond,

[0353] Y 1 -CH2-, -O- or -S-,

[0354] L 1-4 H, F or Cl, preferably H or F, very preferably F,

[0355] x, y 0, 1 or 2, where x+y≤3,

[0356] z 0 or 1,

[0357] Wherein in formula B, the dibenzofuran or dibenzothiophene group may be further substituted by a methyl or methoxy group, and

[0358] Wherein the compound of formula Y contains at least one substituent L which is F or Cl, preferably F 1-4 .

[0359] The LC medium according to this first preferred embodiment may contain one or more compounds of formula G, U, LP1 and / or LP2, II and / or III, one or more compounds selected from formulae Z1, Z2 and Z3, and one or more compounds selected from formulae Y and B.

[0360] The LC media according to this first preferred embodiment are particularly suitable for use in LC displays in HB-FFS or PS-HB-FFS mode.

[0361] In compounds of formula Y and its subformulae, R 1 and R 2Preferably it denotes straight-chain alkyl or alkoxy having 1 to 6 C atoms, furthermore alkenyl having 2 to 6 C atoms, in particular vinyl, 1E-propenyl, 1E-butenyl, 3-butenyl, 1E-pentenyl, 3E-pentenyl or 4-pentenyl.

[0362] In compounds of formula Y and its subformulae, preferably the substituent L 1 and L 2 Both represent F. In another preferred embodiment of the present invention, in the compounds of formula Y and its subformulae, the substituent L 1 and L 2 One represents F and the other represents Cl.

[0363] In a preferred embodiment of the present invention, the LC medium contains one or more compounds of formula Y selected from the following subformulae:

[0364]

[0365] Where R 1 , R 2 , Z x and Z y has the meaning given in formula Y or one of the preferred meanings given above in formula G,

[0366] a means 1 or 2,

[0367] b represents 0 or 1,

[0368] L 1 , L 2 represents F or Cl, preferably F, and

[0369] L 5 represents H atom or CH3,

[0370] express

[0371] express

[0372] Preferably, in compounds of formula Y1 and Y2, L 1 and L 2 Both mean F or L 1 and L 2 One of them represents F and the other represents Cl, or L 1 and L 2 Both mean F or L 1 and L 2 One represents F and the other represents Cl.

[0373] Preferably, the LC medium comprises one or more compounds of formula Y1 selected from the group consisting of the following subformulae:

[0374]

[0375]

[0376]

[0377]

[0378]

[0379]

[0380]

[0381]

[0382]

[0383]

[0384]

[0385]

[0386]

[0387]

[0388] in

[0389] a means 1 or 2,

[0390] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0391] "Alkenyl" means a straight-chain alkenyl group having 2 to 6 C atoms, and

[0392] L 5 Represents an H atom or CH3.

[0393] "Alkenyl" preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0394] Very preferably, the LC medium contains one or more compounds of formula Y1 selected from the group consisting of formulae Y1-1, Y1-2, Y1-7, Y1-12, Y1-17, Y1-22, Y1-40, Y1-41, Y1-42, Y1-44, Y1-50 and Y1-68. 5 Preferably it represents a H atom.

[0395] Further preferably, the LC medium comprises one or more compounds of formula Y2 selected from the group consisting of the following subformulae:

[0396]

[0397]

[0398]

[0399]

[0400]

[0401]

[0402]

[0403] in

[0404] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms, and

[0405] "Alkenyl" means a straight-chain alkenyl group having 2 to 6 C atoms,

[0406] (O) represents an oxygen atom or a single bond, and

[0407] L 5 represents an H atom or CH 3 , preferably an H atom.

[0408] "Alkenyl" preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0409] Very preferably, the LC medium contains one or more compounds of formula Y2 selected from formulae Y2-2 and Y2-10.

[0410] The proportion of compounds of formula Y1 or subformulae thereof in the LC medium is preferably from 0 to 10% by weight.

[0411] The proportion of compounds of formula Y2 or subformulae thereof in the LC medium is preferably from 0 to 10% by weight.

[0412] The total proportion of compounds of the formulae Y1 and Y2 or subformulae thereof in the medium is preferably from 1 to 20% by weight, very preferably from 2 to 15% by weight.

[0413] Preferably, the LC medium contains 1, 2 or 3 compounds of the formulae Y1 and Y2 or subformulae thereof, very preferably selected from the group consisting of the formulae Y1-2, Y1-22, Y1-66, Y1-70, Y2-6 and Y2-22.

[0414] In another preferred embodiment of the present invention, the LC medium contains one or more compounds of the formula Y having the following subformula:

[0415]

[0416] Where L 1 , L 2 , R 1 and R 2 has one of the meanings given in formula Y or one of the preferred meanings as given in formulae G, LP1 and LP2.

[0417] Preferred compounds of formula Y3 are selected from the group consisting of the following subformulae:

[0418]

[0419]

[0420]

[0421]

[0422] in,

[0423] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms;

[0424] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl group having 2 to 6 C atoms; and

[0425] (O) represents an oxygen atom or a single bond.

[0426] “Alkenyl” and “alkenyl*” preferably represent CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0427] Particularly preferred compounds of formula Y3 are selected from the group consisting of the following subformulae:

[0428]

[0429] Among them, "alkoxy" and "alkoxy * " each independently of one another preferably denotes straight-chain alkoxy having 3, 4 or 5 C atoms.

[0430] Preferably, in compounds of formula Y3 and its subformulae, L 1 and L 2 Both represent F. Further preferably, in the compound having formula Y3, the substituent L 1 and L 2 One represents F and the other represents Cl.

[0431] The proportion of compounds of the formula Y3 or subformulae thereof in the LC medium is preferably from 0 to 10% by weight, very preferably from 1 to 6% by weight.

[0432] Preferably, the LC medium contains 1, 2 or 3 compounds of formula Y3 or a subformulae thereof, more preferably compounds of formula Y3-6, very preferably compounds of formula Y3-6A.

[0433] In yet another preferred embodiment of the present invention, the LC medium contains one or more compounds of formula Y having subformula Y4:

[0434]

[0435] Where R 1 and R 2 Each independently has one of the meanings indicated above in formula Y, and

[0436]

[0437] Each independently expresses

[0438]

[0439] Where L 5 represents F or Cl, preferably F, and L 6 represents F, Cl, OCF3, CF3, CH3, CH2F or CHF2, preferably F, and preferably at least one of the rings G, I and K is different from unsubstituted benzene.

[0440] The most preferred compounds of formula Y4 are selected from the group consisting of the following subformulae:

[0441]

[0442]

[0443]

[0444] in

[0445] R represents a straight-chain alkyl or alkoxy group having 1 to 7 C atoms,

[0446] (O) represents an oxygen atom or a single bond, and

[0447] m represents an integer from 1 to 6.

[0448] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

[0449] The proportion of compounds of formula Y4 or subformulae thereof in the medium is preferably from 0 to 10% by weight, very preferably from 1 to 6% by weight.

[0450] Particularly preferred compounds are those having the following sub-formula

[0451]

[0452]

[0453] in

[0454] “Alkyl” and “alkyl*” each independently of one another denote a straight-chain alkyl group having 1 to 6 C atoms, in particular ethyl, propyl or pentyl.

[0455] The following compounds are particularly advantageously used:

[0456]

[0457] In another preferred embodiment of the present invention, the LC medium contains one or more compounds of formula Y selected from the group consisting of the following subformulae:

[0458]

[0459] Where R 5 With the above formula Y for R 1 One of the indicated meanings, "alkyl" represents a straight-chain alkyl group having 1 to 6 C atoms, d represents 0 or 1, and z and m each independently represent an integer from 1 to 6.

[0460] The R 5 Particularly preferably C 2-6-alkyl or -alkoxy or C 2-6 -alkenyl, d is preferably 1. The LC media according to the invention preferably comprise one or more compounds of the above-mentioned formulae in an amount of ≥ 5% by weight.

[0461] Further preferred embodiments are indicated below:

[0462] - the LC medium comprises one or more compounds of formula Y having the following sub-formula

[0463]

[0464] Where R 1 , R 2 , L 1 , L 2 , X, x, and Z x has the meanings given in formula Y, and wherein at least one of the rings X is cyclohexenylene.

[0465] Preferably, the substituent L 1 and L 2 Both represent F. Further preferably, the substituent L 1 and L 2 One represents F and the other represents Cl.

[0466] The compound of formula LY is preferably selected from the group consisting of the following sub-formulae:

[0467]

[0468]

[0469] in

[0470] R 1 has the meaning indicated in the above formula Y, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6.

[0471] R 1 Preferably, it represents a straight-chain alkyl radical having 1 to 6 C atoms or a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH3, C2H5, n-C3H7, n-C4H9, n-C5H 11 , CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0472] Highly preferred are compounds of formula LY4.

[0473] Preferably, the medium contains 1, 2 or 3 compounds of formula LY, very preferably compounds of formula LY4.

[0474] The proportion of compound of formula LY or a subformulae thereof in the medium is preferably from 1 to 10% by weight.

[0475] - the medium comprises one or more compounds of formula Y represented by the following sub-formula:

[0476]

[0477] Where R 1 , R 2 , L 1 , L 2 , Y, y, and Z y has the meanings given in formula Y, and wherein at least one of the rings Y is tetrahydropyran.

[0478] The compound of formula AY is preferably selected from the group consisting of the following sub-formulae:

[0479]

[0480]

[0481]

[0482] in

[0483] R 1 has the meaning indicated above,

[0484] "Alkyl" means a straight-chain alkyl group having 1 to 6 C atoms,

[0485] (O) represents an oxygen atom or a single bond, and

[0486] v represents an integer from 1 to 6.

[0487] R 1 Preferably, it represents a straight-chain alkyl radical having 1 to 6 C atoms or a straight-chain alkenyl radical having 2 to 6 C atoms, in particular CH3, C2H5, n-C3H7, n-C4H9, n-C5H 11 , CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0488] In compounds of formula B and its subformulae, R 1 and R 3Preferably it is straight-chain alkyl or alkoxy having 1 to 6 C atoms, in particular methoxy, ethoxy, propoxy or butoxy, furthermore alkenyl having 2 to 6 C atoms, in particular vinyl, 1E-propenyl, 1E-butenyl, 3-butenyl, 1E-pentenyl, 3E-pentenyl or 4-pentenyl.

[0489] In a preferred embodiment of the invention, the medium contains one or more compounds of formula B selected from the following subformulae:

[0490]

[0491] where Y 1 , L 1 , L 2 , R 1 and R 3 has the meaning given in formula B.

[0492] Preferred compounds of formula B1 are selected from the following sub-formulae:

[0493]

[0494] Where R 1 and R 3 independently represents a straight-chain alkyl group having 1 to 6 C atoms, wherein one or more CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to each other and wherein one or more H atoms may be replaced by a halogen atom.

[0495] Very preferred are compounds of the formulae B1-1 and B1-2 in which both radicals (O) represent oxygen atoms and R 1 and R 3 Alkyl independently represents methyl, ethyl, propyl, butyl, pentyl or hexyl, which are preferably straight-chain. Very preferably, one "alkyl" is ethyl and the other "alkyl*" is n-pentyl.

[0496] Particularly preferred are compounds having the formula B1-2.

[0497] Preferably, the compound of formula B1-1 is selected from the group of compounds of formulae B1-1-1 to B1-1-11, preferably of formula B1-1-6:

[0498]

[0499]

[0500] in

[0501] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0502] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl radical having 2 to 6 C atoms,

[0503] “Alkoxy” and “alkoxy*” each independently of one another denote a straight-chain alkoxy radical having 1 to 6 C atoms.

[0504] Preferably, the compound of formula B1-2 is selected from the group of compounds of formulae B1-2-1 to B1-2-10, preferably of formula B1-2-6:

[0505]

[0506]

[0507] in

[0508] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0509] "Alkenyl" and "alkenyl*" each independently of one another denote a straight-chain alkenyl radical having 2 to 6 C atoms,

[0510] “Alkoxy” and “alkoxy*” each independently of one another denote a straight-chain alkoxy radical having 1 to 6 C atoms.

[0511] Optionally, the LC medium comprises one or more compounds of formula B1-1A and / or B1-2A:

[0512]

[0513]

[0514] in

[0515] (O) represents O or a single bond,

[0516] R IIIA represents an alkyl or alkenyl group or a group Cy-C having up to 7 C atoms m H 2m+1 -,

[0517] m and n, identically or differently, are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1,

[0518] Cy denotes a cycloaliphatic radical having 3, 4 or 5 ring atoms, optionally substituted by alkyl or alkenyl each having up to 3 C atoms, or by halogen or CN, and preferably denotes cyclopropyl, cyclobutyl or cyclopentyl.

[0519] The compound of formula B1-1A and / or B1-2A is contained in the medium alternatively or in addition to the compound of formula B1-1 and B1-2, preferably in addition.

[0520] Preferred compounds having formula B1-1A and / or B1-2A are also the following compounds:

[0521]

[0522]

[0523] wherein alkoxy represents a straight-chain alkoxy radical having 1 to 6 C atoms or alternatively -(CH2) n F, wherein n is 2, 3, 4, or 5, preferably C2H4F.

[0524] The proportion of compounds of the formula B1 or its subformulae in the LC medium is preferably from 1 to 20% by weight, very preferably from 1 to 15% by weight.

[0525] Preferably, the LC medium contains 1, 2 or 3 compounds of formula B1 or subformulae thereof.

[0526] In a preferred embodiment of the present invention, the LC medium may comprise one or more compounds of formula B2-2

[0527]

[0528] in

[0529] R 1 , R 3 Identically or differently represent H, alkyl or alkoxy having 1 to 6 C atoms, wherein one or more CH2 groups in these groups are optionally independently of one another replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a way that the O atoms are not directly connected to one another and wherein, in addition, one or more H atoms may be replaced by halogen.

[0530] The compound of formula B2-2 is preferably selected from the group of compounds of formulae B2-2-1 to B2-2-10:

[0531]

[0532]

[0533] Where R 3 represents alkyl having 1 to 6 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively represents cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively -(CH2) n F, wherein n is 2, 3, 4, or 5, preferably C2H4F.

[0534] Particularly preferred compounds of formula B2 are selected from the following sub-formulae:

[0535]

[0536]

[0537] The proportion of compounds of the formula B2 or its subformulae in the LC medium is preferably from 1 to 20% by weight, very preferably from 1 to 15% by weight.

[0538] Preferably, the LC medium contains 1, 2 or 3 compounds of formula B2 or subformulae thereof.

[0539] Preferred compounds of formula B3 are selected from the following sub-formulae:

[0540]

[0541] Where R 1 has one of the meanings given in formula B3 and preferably denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl, and X 1 has one of the meanings given in formula B3 and preferably represents CF3 or OCF3.

[0542] Preferred compounds of formula B3 are selected from the following sub-formulae:

[0543]

[0544]

[0545] Where R 1 has one of the meanings given in formula B3 and preferably denotes straight-chain alkyl having 1 to 6 C atoms, very preferably methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably ethyl or propyl, most preferably propyl.

[0546] Most preferred are compounds having formula B3-1-1 and B3-2-2.

[0547] In a preferred embodiment, the LC medium contains one or more compounds of formula B or its subformulae B1, B2, B3, B1-1, B1-2, B2-1, B2-2, B2-3, B3-1, B3-2, B3-1-1, B3-1-2, B3-2-1 and B3-2-2, in which the dibenzofuran or dibenzothiophene group is substituted by methyl or methoxy, preferably by methyl, preferably in the para position to the substituent F, very preferably in the para position to the substituent F (i.e. in the terminal group R 2 or X 1 of the interval).

[0548] The proportion of compounds of the formula B3 or its subformulae in the LC medium is preferably from 1 to 20% by weight, very preferably from 1 to 10% by weight.

[0549] Preferably, the LC medium contains 1, 2 or 3 compounds of formula B3 or a subformulae thereof.

[0550] Preferably, the total proportion of compounds of the formulae Y and B or subformulae thereof in the LC medium is from 2 to 25% by weight, very preferably from 3 to 20% by weight.

[0551] Compounds having the formula ST

[0552] In some preferred embodiments of the present invention, the LC medium may further comprise one or more compounds of the general formula ST:

[0553]

[0554] The substituents have the following meanings:

[0555] express

[0556] X 21 , X 22 Each independently represents -O-, -CH2-, -CHR 23 -or-NR 23 -,

[0557] R 21 and R 22 Each independently of one another represents an H atom or an alkyl or alkoxy group having 1 to 12 C atoms, an alkenyl, alkynyl, alkenyloxy or alkoxyalkyl group having 2 to 12 C atoms, or a cycloalkyl group having 3 to 12 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms can be replaced by halogen atoms, or cycloalkyl or cycloalkoxy having 3 to 12 C atoms, in which one or more H atoms can be replaced by halogen atoms,

[0558] R 23 represents an H atom, an alkyl group or an alkoxy group having 1 to 10 C atoms,

[0559] r represents 0 or 1.

[0560] LC media comprising compounds of the following subformulae ST-1, ST-2 and ST-3 show particularly high long-term thermal and UV stability:

[0561]

[0562]

[0563] The substituents have the following meanings:

[0564] express

[0565] R 21 and R 22 each independently of one another represents an H atom or an alkyl or alkoxy group having 1 to 7 C atoms, and

[0566] r represents 0 or 1.

[0567] In a particularly preferred embodiment, the compound having the general formula ST can be selected from the following specific structures:

[0568]

[0569]

[0570]

[0571]

[0572] In a further preferred embodiment, the LC media according to the invention may comprise at least one further sterically hindered phenol, which are mentioned in Table B below.

[0573] Compounds having formula H

[0574] The LC medium may optionally contain one or more compounds of formula H

[0575]

[0576] in

[0577] R 11 each independently of one another represents an H atom, F, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or multiple -CH2- groups (if present) may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and one or more -CH2- groups (if present) may be replaced by -CH=CH- or -C≡C-, and in which one or multiple H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Instead,

[0578] R 12 each independently represents an H atom, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or multiple -CH2- groups can be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be replaced by -O-, a hydrocarbon group containing cycloalkyl or alkylcycloalkyl units, in which one -CH2- group or multiple -CH2- groups can be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be replaced by -O-, and in which one H atom or multiple H atoms can be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 substituted, or aromatic or heteroaromatic hydrocarbon radicals in which one or more H atoms may be replaced by OR 13 、N(R 13 )(R 14 ) or R 15 Instead,

[0579] R 13 and R 14 each independently of one another represents an alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxylic acid group having 6 to 12 C atoms,

[0580] R 15 each independently of one another represents an alkyl group having 1 to 10 C atoms, in which one -CH2- group or a plurality of -CH2- groups may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-,

[0581] R 16 each independently represents an H atom, an alkyl or alkoxy group having 1 to 10 C atoms, an O-cycloalkyl group having 3 to 12 C atoms, an O ●or OH,

[0582] S 11 and S 12 each independently of one another represents an alkylene radical having 1 to 20 C atoms, in which one -CH2- group or a plurality of -CH2- groups (if present) may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and in which one H atom or a plurality of H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Replace, or represent a single bond,

[0583] Y 11 To Y 14 each independently represents a methyl group or an ethyl group,

[0584] X 11 Represents C,

[0585] Z 11 To Z 14 Each independently represents -O-, -(C=O)-, -O-(C=O)-, -(C=O)-O-, -O-(C=O)-O-, -(NR 13 )-、-NR 13 -(C=O)- or a single bond, if S 11 is a single bond, then Z 11 and Z 12 If the two are different, it means -O-; if S 12 is a single bond, then Z 13 and Z 14 If both do not represent -O-, and if q represents 0, then Z 12 and Z 13 The two are different at the same time, which means -O-.

[0586] p means 1 or 2,

[0587] q represents 0 or 1,

[0588] o represents (3-p),

[0589] n represents an integer from 1 to 10,

[0590] m represents an integer from 0 to 8, wherein

[0591] n*p represents an integer from 1 to 10, preferably from 3 to 8, and

[0592] represents an organic moiety having (m+n) bonding sites,

[0593] In some preferred embodiments of the present invention, in the compound having formula H,

[0594] express

[0595] (biphenyl-1,1',3,3'-tetrayl) or

[0596] (Benzene-1,2,4,5-tetrayl)

[0597] express (Benzene-1,3,5-triyl) or

[0598] (Benzene-1,2,4-triyl),

[0599] represents -(CH2-)2, -(CH2-)3, -(CH2-)4, -(CH2-)5, -(CH2-)6, -(CH2-)7, -(CH2-)8, i.e. ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl,

[0600] (1,4-phenylene),

[0601] (1,3-phenylene),

[0602] (1,2-phenylene) or

[0603] (trans-1,4-cyclohexylene) and / or

[0604] in

[0605] -Z 12 -S 11 -Z 11 - represents -O-, S independently of each other at each occurrence 11 -O-, -OS 11 -O-, -(C=O)-OS 11 -O-, -O-(C=O)-S 11 -O-, -O-(C=O)-S 11 -(C=O)-O-, -OS 11 -(C=O)-O-, -(C=O)-OS 11 -C, -(C=O)-OS11 -O-(C=O)- or -(NR 13 )-S 11 -O-、-(NR 13 -C(=O)-S 11 -(C=O)-O or a single bond, preferably -O-, -S 11 -O-, -OS 11 -O-, -(C=O)-OS 11 -O-, -O-(C=O)-S 11 -O-or-OS 11 -(C=O)-O-, and / or

[0606] S 11 preferably represents an alkylene radical having 1 to 20 C atoms, and / or

[0607] R 11 If present, represents alkyl, alkoxy or H, preferably H or alkyl, and / or

[0608] R 12 represents H, methyl, ethyl, propyl, isopropyl or 3-heptyl, or cyclohexyl.

[0609] In a preferred embodiment of the present application, in a compound having formula H,

[0610]

[0611] represents a group selected from the following group:

[0612]

[0613] In a further preferred embodiment of the present application, in a compound having formula H,

[0614]

[0615] represents a group selected from the following group

[0616]

[0617] In a still further preferred embodiment of the present invention, in compounds of formula H, wherein p preferably represents 1,

[0618]

[0619] express Preferably -OS 11 -O-, -S 11 -O-or-OS 11 -,

[0620] Particularly preferably -OS 11 -O- or -S 11 -O-.

[0621] In a further preferred embodiment of the present invention, in the compound of formula H, the group

[0622]

[0623] represents a group selected from the following group

[0624]

[0625] In a further preferred embodiment of the present invention, wherein p is 2, which may be the same as or different from those described above, in the compound having formula H,

[0626]

[0627] represents a group selected from the following group

[0628]

[0629] In yet further preferred embodiments of the present invention, which may be the same as or different from those described above, in compounds of formula H, the group

[0630]

[0631] In each occurrence, they are expressed independently of each other

[0632]

[0633] Preferably

[0634]

[0635] Compounds of the following general formulae H-1-1, H-1-2 and H-1-3 have been shown to be particularly effective UV stabilizers in LC mixtures, in particular with regard to VHR stability:

[0636]

[0637] Among them, ZG, R 16 and n are as defined above and n represents an integer from 1 to 8. These compounds are very suitable as stabilizers in LC mixtures and stabilize the VHR of the mixtures upon UV exposure.

[0638] In a particularly preferred embodiment, the one or more compounds of formula H may be selected from the group consisting of compounds of the following formulae H-2-1 to H-2-6:

[0639]

[0640]

[0641] in

[0642] R 11 each independently represents an H atom, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or multiple -CH2- groups (if present) may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and one or more -CH2- groups (if present) may be replaced by -CH=CH- or -C≡C-, and in which one or multiple H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Instead,

[0643] R 16 Represents H atom or O · ,

[0644] n represents an integer from 0 to 12, and

[0645] S 11 and S 12 each independently of one another represents an alkylene radical having 1 to 20 C atoms, in which one -CH2- group or a plurality of -CH2- groups (if present) may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and in which one H atom or a plurality of H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Instead, or represents a single bond.

[0646] In a preferred embodiment of the invention, the LC media according to the invention comprise in each case one or more compounds of the formula H selected from the following group of compounds of the formulae:

[0647]

[0648]

[0649]

[0650]

[0651]

[0652]

[0653]

[0654]

[0655] The preferred content of the one or more compounds of formula H in the LC medium depends inter alia on the intrinsic chemical stability of the LC medium and on the nature of the compound of formula H. 16 Compounds of the formula H representing O·, which are referred to as NO radical-type HALS, are preferably used in a proportion ranging from 50 ppm to 1000 ppm, based on the weight of the LC medium. 16 The compound having the formula H representing an H atom, which is referred to as NH radical-type HALS, is advantageously used in a proportion ranging from 50 ppm to 2000 ppm.

[0656] Further preferred LC media are selected from the following preferred embodiments, including any combination thereof:

[0657] Combinations of compounds of formula G and U with compounds of formula LP1, Z1 to Z7 and II and / or III

[0658] Combinations of compounds of formula G and U with compounds of formula LP2, Z1 to Z7 and II and / or III

[0659] Combinations of compounds of formula G and U with compounds of formula LP1, LP2, II and / or III and compounds of formula Z1 and Z4

[0660] -LC medium comprises one or more compounds of formula G and U or subformulae thereof and LP1 and / or LP2, II and / or III and one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4, Z5, V, VI, VII, VIII, XIV, XV, XVI, XVIIa, XVIIb, XVIIc, XVIII, XIX, XX, XXI, XXIII, XXIV, XXV, XXVI, XXVII, XXVIII, XXIX, XXX, XXX-1, XXX-2, XXX-3, XXXII, XXXIII and S and subformulae thereof.

[0661] -LC medium comprises one or more compounds of formula I or its subformulae and LP1 and / or LP2, II and / or III and one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4, Z5, IV, VI, XII, XIV, XVI, XVIIa, XVIIb, XVIIc, XX, LP1-1, XXIII, XXIX and S and subformulae thereof.

[0662] - The LC medium comprises one or more compounds selected from the group consisting of formulae II-1, II-2 and II-3, very preferably selected from formulae II-1 and II-2. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 25% by weight.

[0663] - The LC medium contains one or more compounds selected from the group consisting of formulae III-1, III-4, III-6, III-16, III-19 and III-20, very preferably selected from the group consisting of formulae III-1, III-6, III-16 and III-20. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 30% by weight.

[0664] - The LC medium comprises one or more compounds of formula IV, preferably selected from formula IVa or IVc, very preferably selected from formula IVa-1 or IVc-1, most preferably formula IVc-1. The individual concentration of each of these compounds is preferably from 2 to 15% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight.

[0665] - The LC medium comprises one or more compounds of formula VI, preferably selected from formula VIb. The individual concentration of each of these compounds is preferably from 1 to 20% by weight. The total concentration of these compounds is preferably from 5 to 20% by weight.

[0666] - The LC medium comprises one or more compounds of formula Z1, preferably selected from formula Z1-1. The total concentration of these compounds is preferably from 1 to 60% by weight, more preferably from 5 to 50% by weight.

[0667] The LC medium comprises one or more compounds of formula Z2, preferably selected from the group consisting of formulae Z2-1 and Z2-2. The total concentration of these compounds is preferably from 2 to 35% by weight, very preferably from 3 to 25%.

[0668] The LC medium comprises from 5 to 20% by weight of a compound of formula Z3, preferably of formula Z3-1.

[0669] The LC medium comprises from 5 to 20% by weight of a compound of formula Z4, preferably of formula Z4-1.

[0670] The LC medium comprises from 10 to 65%, very preferably from 20 to 60%, by weight of compounds of formula Z5.

[0671] - The LC medium comprises one or more compounds of formula LP1-1, preferably formula LP1-1a or LP2-1b, very preferably formula LP1-1a. The concentration of these compounds is preferably from 2 to 15% by weight.

[0672] The LC medium comprises from 1 to 15% by weight of a compound of formula LP2-1b.

[0673] - The LC medium comprises one or more compounds of formula XII, preferably formula XIIa or XIIb, very preferably formula XIIa, most preferably formula XIIa-1. The concentration of these compounds is preferably from 2 to 15% by weight.

[0674] The LC medium comprises from 1 to 15% by weight of the compound of formula XIIb.

[0675] - The LC medium comprises one or more compounds of formula XIV, preferably formula XIVd, very preferably formula XIVd-1. The concentration of these compounds is preferably from 2 to 10% by weight.

[0676] - The LC medium comprises one or more compounds of formula XVIb, preferably formula XVIb-1, XVIb-2 and / or XVIb-3. The concentration of these compounds is preferably from 2 to 15% by weight.

[0677] - The LC medium comprises one or more compounds of formula XVIc, preferably formula XVIc-1, XVIc-2 and / or XVIc-3. The concentration of these compounds is preferably from 2 to 20% by weight.

[0678] The LC medium comprises one or more compounds selected from the group consisting of formulae XVIIa, XVIIb and XVIIc, very preferably compounds of formula XVIIa wherein L is H and compounds of formula XVIIb wherein L is F. The total concentration of these compounds is preferably from 0.5 to 5% by weight.

[0679] - The LC medium comprises one or more compounds of formula XX, preferably formula XXa. The concentration of these compounds is preferably from 2 to 10% by weight.

[0680] - The LC medium comprises one or more compounds of formula XXI, preferably formula XXIa. The concentration of these compounds is preferably from 2 to 10% by weight.

[0681] - The LC medium comprises one or more compounds of formula XXIII, preferably formula XXIIIa. The concentration of these compounds is preferably from 0.5 to 5% by weight.

[0682] - The LC medium comprises one or more compounds of formula XXIX, preferably formula XXIXa. The concentration of these compounds is preferably from 2 to 10% by weight.

[0683] - The LC medium comprises one or more compounds of formula XXX. The concentration of these compounds is preferably from 2 to 10% by weight.

[0684] - The LC medium comprises one or more compounds of formula XII. The concentration of these compounds is preferably from 2 to 10% by weight.

[0685] - The LC medium comprises one or more compounds of formula G and U (preferably formula G-1 and U-1) and LP1 and / or LP2, II and / or III, one or more compounds selected from the group consisting of formulae Z1, Z2 and Z3 or subformulae thereof, one or more compounds selected from the group consisting of formulae XIV, one or more compounds selected from the group consisting of formulae IV, VI, XX, XXIII and XXIX or subformulae thereof, and one or more compounds selected from the group consisting of formulae LP2-1, XVI, XVIIa, XVIIb, XVIIc or subformulae thereof.

[0686] - The LC medium comprises one or more compounds of formula G and U (preferably formula G-1 and U-1), LP1 and / or LP2, II and / or III, one or more compounds selected from the group consisting of formula Z1, Z2, Z3, Z4 and Z5 or subformulas thereof, one or more compounds selected from the group consisting of formula XIVd or subformulas thereof, one or more compounds selected from the group consisting of formula IVc, VIb, XXa, XXIIIa and XXIXa or subformulas thereof, and one or more compounds selected from the group consisting of formula LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc or subformulas thereof.

[0687] - The LC medium comprises one or more compounds of formula G and U (preferably formula G-1 and U-1), LP1 and / or LP2, II and / or III, one or more compounds selected from the group consisting of formulae Z1, Z2 and Z3 or subformulae thereof, one or more compounds of formula Y (preferably selected from the group consisting of formulae Y1 and Y2), one or more compounds selected from the group consisting of formula XIV, one or more compounds selected from the group consisting of formulae II, III, IV, VI, XX, XXIII and XXIX or subformulae thereof, and one or more compounds selected from the group consisting of formulae LP2-1, XVI, XVIIa, XVIIb, XVIIc or subformulae thereof.

[0688] - The LC medium comprises one or more compounds of formula G and U (preferably formula G-1 and U-1), LP1 and / or LP2, one or more compounds selected from the group consisting of formula Z1, Z2, Z3, Z4 and Z5 or subformulae thereof, one or more compounds of formula B (preferably selected from the group consisting of formula B1, B2 and B3), one or more compounds of formula XIVd or subformulae thereof, one or more compounds selected from the group consisting of formula II, III, IVc, VIb, XXa, XXIIIa and XXIXa or subformulae thereof, and one or more compounds selected from the group consisting of formula LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc or subformulae thereof.

[0689] - In addition to compounds of formulae G and U, LP1 and / or LP2, the LC medium comprises further compounds selected from the group of compounds of formulae Z1, Z2, Z3, IV, LP1-1, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX and XXIV or subformulae thereof.

[0690] - In addition to compounds of formulae G and U, LP1 and / or LP2, the LC medium comprises further compounds selected from the group of compounds of formulae Z1, Z2, Z3, IV, LP2-1, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX and XXIV or subformulae thereof.

[0691] The proportion of compounds of formulae G and U or subformulae thereof in the LC medium is from 1 to 30%, very preferably from 2 to 25%, most preferably from 2 to 20% by weight.

[0692] The proportion of compounds of the formulae Z1, Z2, Z3, Z4 and Z5 or subformulae thereof in the LC medium is generally from 10 to 65%, very preferably from 20 to 60% by weight.

[0693] The proportion of compounds of formula Y or subformulae thereof in the LC medium is generally from 0 to 15%, very preferably from 2 to 10% by weight.

[0694] The proportion of compounds of formula B or its subformulae in the LC medium is generally from 0 to 15%, very preferably from 2 to 10% by weight.

[0695] The proportion of compounds of the formulae II, III, IV-VIII, XVIII-XXIII and XXVII-XXX in the LC medium is generally 30 to 60% by weight.

[0696] The proportion of compounds of the formulae XIV and XV in the LC medium is generally 40 to 70% by weight.

[0697] The proportion of compounds of the formulae XIV, XVIIa-c and XXXII in the LC medium is generally from 0.5 to 15% by weight.

[0698] The term "alkyl" or "alkyl*" in the present application includes straight-chain and branched alkyl groups having 1 to 6 carbon atoms, in particular the straight-chain groups methyl, ethyl, propyl, butyl, pentyl and hexyl. Groups having 2 to 5 carbon atoms are generally preferred.

[0699] The term "alkenyl" or "alkenyl * " includes straight-chain and branched alkenyl groups having 2 to 6 carbon atoms, especially straight-chain groups. Preferred alkenyl groups are C2-C7-1E-alkenyl, C4-C6-3E-alkenyl, especially C2-C6-1E-alkenyl. Examples of particularly preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl and 5-hexenyl. Groups with up to 5 carbon atoms are generally preferred, especially CH2=CH, CH3CH=CH.

[0700] The term "fluoroalkyl" preferably includes straight chain groups with terminal fluorine, ie fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. However, other positions of fluorine are not excluded.

[0701] The term "oxaalkyl" or "alkoxy" preferably includes groups having the formula C n H 2n+1 -O-(CH2) mwherein n and m each independently represent 1 to 6. m may also represent 0. Preferably, n=1 and m=1 to 6 or m=0 and n=1 to 3. Further preferably, the alkoxy or oxaalkyl group may also contain one or more additional O atoms, so that the oxygen atoms are not directly connected to each other.

[0702] By appropriately selecting R in formula II and III 0 and X 0 In the sense of the term "alkyl", the addressing time, the threshold voltage, the steepness of the transfer characteristic line, etc. can be varied in a desired manner. For example, 1E-alkenyl, 3E-alkenyl, 2E-alkenyloxy, etc. generally lead to shorter addressing times, an improved nematic tendency and a higher ratio between the elastic constants K3 (bend) and K1 (bend) compared to alkyl and alkoxy groups. 4-alkenyl, 3-alkenyl, etc. generally lead to lower threshold voltages and lower K3 / K1 values ​​compared to alkyl and alkoxy groups. The LC media according to the invention are characterized in particular by high Δε values ​​and therefore have significantly faster response times than LC media from the prior art.

[0703] The optimum mixing ratio of the compounds of the above-mentioned formulae depends essentially on the desired properties, the choice of the components of the above-mentioned formulae and the choice of any further components which may be present.

[0704] A suitable mixing ratio within the above-indicated range can be easily determined on a case-by-case basis.

[0705] The total amount of compounds of the above-mentioned formula in the LC medium according to the invention is not critical. Thus, the LC medium may contain one or more further components for the purpose of optimizing various properties. However, the higher the total concentration of compounds of the above-mentioned formula, the greater the effect of the desired improvement on the properties of the medium observed.

[0706] In a particularly preferred embodiment, the LC media according to the invention comprise compounds of the formulae IV to VIII (preferably IV and V), in which X 0 Denotes F, OCF3, OCHF2, OCH=CF2, OCF=CF2 or OCF2-CF2H. The favorable synergy with compounds of formulae G and U, LP1 and / or LP2, II and III leads to particularly favorable properties. In particular, LC media comprising compounds of formulae G and U, LP1 and / or LP2, II and III are distinguished by their low threshold voltage.

[0707] The individual compounds of the above-mentioned formulae and subformulae thereof which can be used in the LC media according to the invention are known or can be prepared analogously to the known compounds.

[0708] The present invention also relates to a process for preparing an LC medium as described above and below, by mixing one or more compounds of the formulae G and U with one or more compounds of the formulae LP1 and / or LP2 and one or more compounds selected from the group consisting of formulae II, III, Z1, Z2, Z3, Z4, IV, VI, XIV, LP2-1, XVI, XVIIa, XVIIb, XVIIc, XX, XXIII, XXIX.

[0709] The LC medium of the present invention may optionally contain one or more polymerizable compounds. The polymerizable compounds are preferably selected from the group consisting of formula M

[0710] R a -B 1 -(Z b -B 2 ) m -R b M

[0711] where the individual substituents have the following meanings, identically or differently on each occurrence and independently of one another:

[0712] R a and R b P, P-Sp-, H, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, SF5 or a straight-chain or branched alkyl radical having 1 to 25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may each be replaced independently of one another by -C(R 0 )=C(R 00 )-、-C≡C-、-N(R 00 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, in such a way that the O and / or S atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by F, Cl, Br, I, CN, P or P-Sp-, wherein if B 1 and / or B 2 Contains saturated C atoms, then R a and / or R b It can also represent a group spiro-bonded to the saturated C atom,

[0713] The substituent R a and R b At least one of them represents or contains a group P or P-Sp-,

[0714] P polymerizable group,

[0715] Sp spacer or single bond,

[0716] B 1 and B 2 an aromatic, heteroaromatic, alicyclic or heterocyclic radical, preferably having 4 to 25 ring atoms, which may also contain fused rings, and which is unsubstituted or mono- or polysubstituted by L,

[0717] Z b -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR 0 R 00 or single key,

[0718] R 0 and R 00 each independently of one another represents H or an alkyl radical having 1 to 12 C atoms,

[0719] m represents 0, 1, 2, 3 or 4,

[0720] n1 means 1, 2, 3 or 4,

[0721] LP, P-Sp-, OH, CH2OH, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 、-C(=O)R x 、-N(R x )2, optionally substituted silyl, optionally substituted aryl having 6 to 20 C atoms, or linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, wherein, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-,

[0722] P and Sp have the meanings indicated in the above formula M,

[0723] Y 1 represents halogen,

[0724] R xrepresents P, P-Sp-, H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups can be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to one another, and wherein, in addition, one or more H atoms can be replaced by F, Cl, P or P-Sp-, optionally substituted aryl or aryloxy having 6 to 40 C atoms, or optionally substituted heteroaryl or heteroaryloxy having 2 to 40 C atoms.

[0725] It is further preferred that the LC media according to the present invention comprise one or more polymerisable compounds selected from Table H below.

[0726] Preferably, the proportion of polymerisable compounds (preferably selected from formula M and table H) in the LC medium is from 0.01% to 5%, very preferably from 0.05% to 1%, most preferably from 0.1% to 0.5%.

[0727] It has been observed that adding one or more polymerizable compounds, like those selected from Formula M and Table H, to the LC medium results in advantageous properties like fast response time. Such LC media are particularly suitable for use in PSA displays, where they exhibit low image sticking, fast and complete polymerization, rapid generation of stable low pretilt angles after UV exposure, high reliability, high VHR values ​​after UV exposure, and high birefringence. By appropriately selecting the polymerizable compound, the absorption of the LC medium at longer UV wavelengths can be increased, making it possible to use such longer UV wavelengths for polymerization, which is advantageous for the display manufacturing process.

[0728] The polymerizable group P is a group which is suitable for polymerization reactions, such as free radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-analogous transformation reactions, such as addition or condensation on the polymer backbone. Particularly preferred are groups for chain polymerization, in particular 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 epoxy groups.

[0729] Preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, CH2=CW 2 -(O) k3 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH2=CW1 -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-, where W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W 2 and W 3 each independently of one another represents 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 C atoms, W 7 and W 8 Each independently represents H, Cl or an alkyl group having 1 to 5 C atoms, Phe represents 1,4-phenylene which is optionally substituted by one or more substituents L different from P-Sp- as defined above for formula M, k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0730] Very preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, CH2=CW 2 -O-, CH=CW 2 -、CW 1 =CH-CO-(O) k3 -、CW1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -、CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si-, where W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W 2 and W 3 each independently of one another represents 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 C atoms, W 7 and W 8 Each independently represents H, Cl or an alkyl group having 1 to 5 C atoms, Phe represents 1,4-phenylene, k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0731] Very particularly preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, in addition CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-,

[0732] Further preferred polymerizable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate.

[0733] If Sp is different from a single bond, it is preferably of the formula Sp"-X", so that the corresponding substituent P-Sp- conforms to the formula P-Sp"-X"-, wherein

[0734] Sp" denotes an alkylene radical having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and wherein, in addition, one or more non-adjacent CH2 groups may each be independently of one another substituted by -O-, -S-, -NH-, -N(R 0 )-、-Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-、-O-CO-N(R 0 )-、-N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C- in such a way that the O and / or S atoms are not directly connected to each other,

[0735] X" means -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-、-N(R 0 )-CO-、-N(R 0 )-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 2 =CY 3 -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond,

[0736] R 0 and R 00 each independently of one another represents H or an alkyl group having 1 to 20 C atoms, and

[0737] Y 2 and Y 3 Each independently of one another represents H, F, Cl or CN.

[0738] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -、-NR 0 -CO-、-NR 0 -CO-NR 00 - or single key.

[0739] Typical spacer groups Sp and -Sp"-X"- are, for example, -(CH2) p1 -、-(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR 0 R 00 -O) p1 -, wherein p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 has the meaning indicated above in formula M.

[0740] Particularly preferred groups Sp and -Sp"-X"- are -(CH2) p1 -、-(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, wherein p1 and q1 have the meanings indicated above.

[0741] Particularly preferred radicals Sp" are in each case linear ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, vinylene, propenylene and butenylene.

[0742] To produce a PSA display, the polymerisable compounds contained in the LC medium are polymerised or crosslinked (if a compound contains two or more polymerisable groups) by in situ polymerisation in the LC medium between the substrates of the LC display, optionally while applying a voltage to the electrodes.

[0743] The structure of the PSA display according to the invention corresponds to the usual geometries of PSA displays, as described in the prior art cited at the outset. Preference is given to geometries without protrusions, in particular those in which, among other things, the electrode on the color filter side is unstructured and only the electrode on the TFT side has grooves. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006 / 0066793 A1.

[0744] The combination of the compounds of the preferred embodiments mentioned above with the polymerized compounds described above leads in the LC media according to the invention to low threshold voltages, low rotational viscosities and very good low temperature stability, together with constant high bright spots and high VHR values.

[0745] The use of LC media containing polymerizable compounds allows particularly low pretilt angles to be quickly established in PSA displays. In particular, the LC media exhibit significantly shortened response times, in particular also grey-to-grey response times, in PSA displays compared to the media of the prior art.

[0746] Preference is generally given to LC media having a nematic LC phase and preferably no chiral liquid crystal phase.

[0747] The invention also relates to the use of an LC medium according to the invention as described above and below for electro-optical purposes, in particular in shutter glasses, for 3D applications, in TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA and positive PS-VA displays, and to an electro-optical display, in particular a display of the aforementioned type, containing an LC medium according to the invention as described above and below, in particular a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, positive VA (vertically aligned) or positive PS-VA display.

[0748] The invention also relates to an electro-optical display, such as for example an STN or matrix LC (MLC) display, having two plane-parallel outer plates which together with a frame form a cell, an integrated non-linear element for switching individual pixels on the outer plates, and a nematic LC medium with positive dielectric anisotropy and high specific resistance located in the cell, wherein the nematic LC medium is an LC medium according to the invention as described above and below.

[0749] The LC media according to the invention enable a significant broadening of the usable parameter range. The achievable combination of clearing point, viscosity at low temperatures, thermal and UV stability and high optical anisotropy is far superior to previous materials from the prior art.

[0750] In particular, the combination of compounds of formulae G and U with compounds of formulae LP1 and / or LP2 and optionally with compounds selected from formulae II to XXXII or subformulae thereof leads to LC media showing a moderately positive dielectric anisotropy and at the same time an increased dielectric constant ε perpendicular to the longitudinal axis of the LC molecules. ┴, while maintaining low rotational viscosity and low values ​​of the ratio γ1 / K1. This enables energy-saving LC displays, especially those in FFS, HB-FFS, XB-FFS and IPS mode, with high brightness and transmittance and low response times.

[0751] The LC media according to the invention are suitable for mobile applications and TFT applications, such as, for example, mobile phones and PDAs. Furthermore, the LC media according to the invention are particularly suitable for use in FFS, HB-FFS, XB-FFS and IPS displays based on dielectrically positive liquid crystals.

[0752] The LC medium according to the invention allows, while maintaining a nematic phase down to -20°C and preferably down to -30°C, particularly preferably down to -40°C, and a clearing point ≥75°C, preferably ≥80°C, to achieve a rotational viscosity γ1 of ≤120 mPa·s, particularly preferably ≤100 mPa·s, enabling excellent MLC displays with fast response times. The rotational viscosity is measured at 20°C.

[0753] The dielectric anisotropy Δ∈ at 20° C. and 1 kHz of the LC media according to the invention is preferably ≧+1.5, very preferably from +3 to +18, most preferably from +5 to +15.

[0754] The birefringence Δn of the LC media according to the invention at 20° C. is preferably from 0.08 to 0.2, very preferably from 0.09 to 0.15.

[0755] The rotational viscosity γ1 of the LC media according to the invention is preferably ≤120 mPa·s, more preferably ≤110 mPa·s, very preferably ≤90 mPa·s.

[0756] The ratio γ1 / K1 of the LC media according to the invention, wherein γ1 is the rotational viscosity and K1 is the elastic constant of the splay deformation, is preferably ≤7 mPa·s / pN, very preferably ≤6 mPa·s / pN, most preferably ≤5.5 mPa·s / pN.

[0757] The average elastic constant of the LC medium according to the invention is K av Preferably at least 14.0 pN, very preferably at least 15.0 pN, most preferably at least 16.0 pN. av It can be calculated according to the following formula: K av =(K1+K2+K3) / 3≈(K1+1 / 2*K1+K3) / 3.

[0758] The nematic phase range of the LC media according to the invention preferably has a width of at least 90° C., more preferably at least 100° C., in particular at least 110° C. This range preferably extends at least from -25° C. to +90° C.

[0759] It goes without saying that by suitable selection of the composition of the LC medium according to the invention, it is also possible to achieve higher clearing points (for example above 100° C.) at higher threshold voltages or lower clearing points at lower threshold voltages, while retaining other advantageous properties. LC media with higher Δε and thus with lower threshold values ​​can likewise be obtained, with a correspondingly only slightly increased viscosity. MLC displays according to the invention are preferably operated in the first Gooch and Tarry transmittance minimum [CH Gooch and HATarry, Electron. Lett. 10, 2-4, 1974; CH Gooch and HATarry, Appl. Phys., Vol. 8, 1575-1584, 1975], wherein, in addition to particularly advantageous electro-optical properties such as, for example, high steepness of characteristic lines and low angular dependence of the contrast (German Patent 30 22818), a lower dielectric anisotropy is sufficient at the same threshold voltage as in a similar display in the second minimum. This enables the use of the LC media according to the invention to achieve significantly higher specific resistance values ​​in the first minimum than in the case of LC media comprising cyano compounds. By suitable selection of the individual components and their proportions by weight, the person skilled in the art is able to set the birefringence required for a prespecified layer thickness for an MLC display using simple conventional methods.

[0760] Measurement of Voltage Holding Ratio (HR) [S. Matsumoto et al., Liquid Crystals] 5 , 1320 (1989); K. Niwa et al., Proc. SID Conference, San Francisco, June 1984, p. 304 (1984); G. Weber et al., Liquid Crystals 5 ,1381(1989)] have shown that Cyanophenylcyclohexane or a cyclohexane having the formula The LC media according to the invention comprising compounds of the formulae ST-1, ST-2, RV, IA and IB show a significantly smaller decrease in HR upon UV exposure compared to similar LC media containing esters of

[0761] The light and UV stability of the LC media according to the invention are significantly better, ie they show a significantly smaller decrease in HR upon exposure to light, heat or UV.

[0762] The construction of the MLC display according to the invention consisting of polarizer, electrode substrate and surface-treated electrodes corresponds to the usual design of displays of this type. The term "usual design" is here to be described in a broad sense and also includes all derivatives and variants of MLC displays, in particular including matrix display elements based on polycrystalline-Si TFTs or MIMs.

[0763] However, a significant difference between the displays according to the invention and hitherto conventional displays based on twisted nematic cells lies in the choice of the LC parameters of the LC layer.

[0764] The LC media which can be used according to the invention are prepared in a manner conventional per se, for example by mixing one or more compounds as claimed in claim 1 with one or more compounds of the formulae II to XXXII or with further LC compounds and / or additives. Usually, the desired amount of the components used in smaller amounts is dissolved in the components constituting the main constituents, advantageously at elevated temperature. It is also possible to mix solutions of the components in organic solvents, for example in acetone, chloroform or methanol, and to remove the solvent again after thorough mixing, for example by distillation.

[0765] The LC medium may also contain further additives known to the person skilled in the art and described in the literature, such as, for example, polymerization initiators, inhibitors, surface-active substances, light stabilizers, antioxidants (e.g. BHT, TEMPOL), microparticles, free radical scavengers, nanoparticles, etc. For example, 0% to 15% of pleochroic dyes or chiral dopants or initiators such as 651 or 907. Suitable stabilizers and dopants are mentioned in the following Tables F and G. In a preferred embodiment, the LC medium comprises one or more stabilizers selected from Table G. Preferably, the proportion of stabilizers (like those of formula ST and H as described above or listed in Table G) in the LC medium is from 10 to 2000 ppm, very preferably from 30 to 1000 ppm.

[0766] Furthermore, it is possible to add, for example, 0 to 15% by weight of pleochroic dyes to the LC medium, and also nanoparticles, conductive salts, preferably 4-hexyloxybenzoic acid ethyldimethyldodecylammonium, tetrabutylammonium tetraphenylborate or complex salts of crown ethers (see, for example, Haller et al., Mol. Cryst. Liq. Cryst. [Molecular Crystals and Liquid Crystals]). 24, 249-258 (1973)), substances for improving the electrical conductivity, or for changing the dielectric anisotropy, the viscosity and / or the orientation of the nematic phase. Substances of this type are described, for example, in DE-A 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 2637 430 and 28 53 728.

[0767] For the present invention and in the following examples, the structures of the LC compounds are indicated by acronyms, the conversion to chemical formulae being carried out according to the following Tables A to C. All substituents C m H 2m+1 , C n H 2n+1 and C l H 2l+1 or C m H 2m-1 , C n H 2n-1 and C l H 2l-1 is a straight-chain alkyl or alkenyl group, in each case with n, m and 1 C atoms, respectively. Preferably, n, m and 1 are independently 1, 2, 3, 4, 5, 6 or 7. Table A shows the codes of the ring elements of the core of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols of the left-hand and right-hand end groups of the molecule. The acronyms consist of the code of the ring element with an optional linking group, followed by the first hyphen and the code of the left-hand end group, and the second hyphen and the code of the right-hand end group. Table D shows the exemplary structures of the compounds and their respective abbreviations.

[0768] Table A: Ring Elements

[0769]

[0770]

[0771]

[0772] Table B: Bridge Unit

[0773]

[0774] Table C: End Groups

[0775]

[0776]

[0777] where n and m are each integers, and the three dots "..." are placeholders for other abbreviations from the table.

[0778] The following abbreviations are used:

[0779] (n, m, k and l are each independently an integer, preferably 1 to 12, preferably 1 to 6, k and l may possibly also be 0 and preferably 0 to 4, more preferably 0 or 2 and most preferably 2, n is preferably 1, 2, 3, 4 or 5, in the combination "-nO-", it is preferably 1, 2, 3 or 4, preferably 2 or 4, m is preferably 1, 2, 3, 4 or 5, in the combination "-Om", it is preferably 1, 2, 3 or 4, more preferably 2 or 4. The combination "-lVm" is preferably "2V1".)

[0780] Preferred components of the LC media are shown in Tables D and E.

[0781] Table D

[0782]

[0783]

[0784]

[0785]

[0786] Table E

[0787] In the following formulae, n and m each independently of one another represent 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, in particular 2, 3, 5 and furthermore 0, 4, 6.

[0788]

[0789]

[0790]

[0791]

[0792]

[0793]

[0794]

[0795]

[0796]

[0797]

[0798]

[0799]

[0800]

[0801] Particularly preferred are LC media which, in addition to compounds of the formula G, LP1 and / or LP2, comprise at least one, two, three, four or more compounds from Table E.

[0802] Table F

[0803] Table F indicates possible dopants typically added to the LC media according to the invention. The LC media preferably comprise 0-10% by weight, in particular 0.01-5% by weight and particularly preferably 0.01-3% by weight of dopant.

[0804]

[0805]

[0806] Table G

[0807] Mention is made below of stabilizers which can additionally be added to the LC media according to the invention, for example in amounts of 0 to 10% by weight.

[0808]

[0809]

[0810]

[0811]

[0812]

[0813] q = 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10

[0814] Table H

[0815] Table H shows exemplary reactive mesogenic compounds (RM) which can be used in the LC media according to the present invention.

[0816]

[0817]

[0818]

[0819]

[0820]

[0821]

[0822]

[0823]

[0824]

[0825]

[0826]

[0827]

[0828]

[0829]

[0830]

[0831]

[0832]

[0833]

[0834]

[0835]

[0836]

[0837]

[0838] The LC media according to the present invention may optionally comprise one or more polymerisable compounds, preferably selected from polymerisable compounds having formulae RM-1 to RM-184. Among these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-58, RM-64, RM-74, RM-76, RM-88, RM-91, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM-145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170 and RM-171 to RM-184 are particularly preferred.

[0839] Table I

[0840] Table I shows self-aligning additives for homeotropic alignment which can be used in the LC medium of SA-FFS, SA-HB-FFS and SA-XB-FFS displays according to the invention:

[0841]

[0842]

[0843]

[0844]

[0845]

[0846]

[0847]

[0848]

[0849]

[0850]

[0851]

[0852]

[0853] In a preferred embodiment, the LC media, SA-VA and SA-FFS displays according to the invention comprise one or more SA additives selected from the formulae SA-1 to SA-49, preferably from the formulae SA-14 to SA-49, very preferably from the formulae SA-20 to SA-34 and SA-44, in combination with one or more RMs.

[0854] The following examples are intended to illustrate the present invention rather than to limit the present invention.

[0855] In the above and below, percentage data refer to percentages by weight. All temperatures are expressed in degrees Celsius. mp = melting point, cl.p. = clearing point. In addition, C = crystalline, N = nematic, S = smectic and I = isotropic. The data between these symbols refer to transition temperatures. In addition, the following symbols are used:

[0856] V0 Freedericks threshold voltage at 20°C, capacitive [V],

[0857] V 10 For the voltage [V] at 10% transmittance,

[0858] n e The extraordinary refractive index measured at 20°C and 589 nm,

[0859] n0 is the ordinary refractive index measured at 20°C and 589nm,

[0860] Δn Optical anisotropy measured at 20°C and 589 nm,

[0861] ε ┴ The dielectric polarizability (or "dielectric constant") perpendicular to the longitudinal axis of the molecule at 20°C and 1 kHz,

[0862] ε || The dielectric polarizability (or "dielectric constant") parallel to the longitudinal axis of the molecule at 20°C and 1 kHz,

[0863] Dielectric anisotropy of Δε at 20°C and 1kHz,

[0864] cl.p.or

[0865] T(N,I) clearing point [℃],

[0866] ν Flow viscosity measured at 20°C [mm 2 ·s -1 ],

[0867] γ1 Rotational viscosity measured at 20°C [mPa·s],

[0868] K1 elastic constant, "bending" deformation at 20°C [pN],

[0869] K2 elastic constant, "twist" deformation at 20°C [pN],

[0870] K3 elastic constant, "bending" deformation at 20°C [pN], and

[0871] VHR electricity Pressure Save hold Rate .

[0872] Unless expressly stated otherwise, all physical properties are determined according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, state November 1997, Merck KGaA, Germany, and apply for a temperature of 20° C. DETAILED DESCRIPTION

[0873] Example

[0874] Example M1

[0875] The nematic LC medium was prepared as follows:

[0876]

[0877] This LC mixture has a K of 16.32 pN. av and γ1 / K1 of 3.29 mPa·s / pN.

[0878] Mixture Example S1 (Stabilized with a compound having formula H-3-5)

[0879] The nematic LC mixture according to the invention was formulated as follows:

[0880]

[0881] Compared to the unstabilized mixture M1, the addition of 50 ppm of the compound of formula H-3-5 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M1.

[0882]

[0883] Example M2

[0884] The nematic LC medium was prepared as follows:

[0885]

[0886] This LC mixture has a K of 15.93 pN. av and γ1 / K1 of 3.25 mPa·s / pN.

[0887] Mixture Example S2 (Stabilized with a Compound of Formula H-3-3)

[0888] The nematic LC mixture according to the invention was formulated as follows:

[0889] Mixture M2 99.9wt.-% Compounds having formula H-3-3 1 000ppm

[0890] Compared to the unstabilized mixture M2, the addition of 1 000 ppm of the compound of formula H-3-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M2.

[0891]

[0892] Example M3

[0893] The nematic LC medium was prepared as follows:

[0894]

[0895] The LC mixture has a K of 16.43 pN av and γ1 / K1 of 3.30 mPa·s / pN.

[0896] Mixture Example S3 (Stabilized with a Compound of Formula H-3-1)

[0897] The nematic LC mixture according to the invention was formulated as follows:

[0898]

[0899] Compared to the unstabilized mixture M3, the addition of 1 000 ppm of the compound of formula H-3-1 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M3.

[0900]

[0901] Embodiment M4

[0902] The nematic LC medium was prepared as follows:

[0903]

[0904] The LC mixture has a K of 16.35 pN av and γ1 / K1 of 3.18 mPa·s / pN.

[0905] Mixture Example S4 (Stabilized with a Compound of Formula ST-2-3)

[0906] The nematic LC mixture according to the invention was formulated as follows:

[0907] Mixture M4 99.95wt.-% Compounds having the formula ST-2-3 500ppm

[0908] Compared to the unstabilized mixture M4, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M4.

[0909]

[0910] Example M5

[0911] The nematic LC medium was prepared as follows:

[0912]

[0913] The LC mixture has a K of 16.43 pN av and γ1 / K1 of 3.25 mPa·s / pN.

[0914] Mixture Example S5 (Stabilized with a Compound of Formula ST-2-3)

[0915] The nematic LC mixture according to the invention was formulated as follows:

[0916]

[0917] Compared to the unstabilized mixture M5, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M5.

[0918] Example M6

[0919] The nematic LC medium was prepared as follows:

[0920]

[0921]

[0922] Mixture Example S6 (Stabilized with a Compound of Formula H-3-1)

[0923] The nematic LC mixture according to the invention was formulated as follows:

[0924]

[0925] Compared to the unstabilized mixture M6, the addition of 1 000 ppm of the compound of formula H-3-1 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M6.

[0926] Embodiment M7

[0927] The nematic LC medium was prepared as follows:

[0928]

[0929]

[0930] Mixture Example S7 (Stabilized with a Compound of Formula ST-1-3)

[0931] The nematic LC mixture according to the invention was formulated as follows:

[0932]

[0933] Compared to the unstabilized mixture M7, the addition of 500 ppm of the compound of formula ST-1-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M7.

[0934]

[0935] Embodiment M8

[0936] The nematic LC medium was prepared as follows:

[0937]

[0938]

[0939] Mixture Example S8 (Stabilized with a Compound of Formula ST-1-3)

[0940] The nematic LC mixture according to the invention was formulated as follows:

[0941]

[0942] Compared to the unstabilized mixture M8, the addition of 500 ppm of the compound of formula ST-1-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M8.

[0943] Embodiment M9

[0944] The nematic LC medium was prepared as follows:

[0945]

[0946]

[0947] Mixture Example S9 (Stabilized with a Compound of Formula ST-2-3)

[0948] The nematic LC mixture according to the invention was formulated as follows:

[0949] Mixture M9 99.96wt.-% Compounds having the formula ST-2-3 400ppm

[0950] Compared to the unstabilized mixture M9, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M9.

[0951] Embodiment M10

[0952] The nematic LC medium was prepared as follows:

[0953]

[0954]

[0955] Mixture Example S10 (Stabilized with a Compound of Formula H-3-4)

[0956] The nematic LC mixture according to the invention was formulated as follows:

[0957] Mixture M10 99.995wt.-% Compounds having formula H-3-4 50ppm

[0958] Compared to the unstabilized mixture M10, the addition of 50 ppm of the compound of formula H-3-4 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M10.

[0959]

[0960] Embodiment M11

[0961] The nematic LC medium was prepared as follows:

[0962]

[0963]

[0964]

[0965] Mixture Example S11 (Stabilized with a Compound of Formula H-3-2)

[0966] The nematic LC mixture according to the invention was formulated as follows:

[0967] Mixture M11 99.995wt.-% Compounds having formula H-3-2 50ppm

[0968] Compared to the unstabilized mixture M11, the addition of 50 ppm of the compound of formula H-3-2 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M11.

[0969]

[0970] Example M12

[0971] The nematic LC medium was prepared as follows:

[0972]

[0973] The LC mixture has a K of 17.83 pN av and γ1 / K1 of 3.61 mPa·s / pN.

[0974] Mixture Example S12 (Stabilized with a Compound of Formula ST-2-3)

[0975] The nematic LC mixture according to the invention was formulated as follows:

[0976] Mixture M12 99.96wt.-% Compounds having the formula ST-2-3 400ppm

[0977] Compared to the unstabilized mixture M12, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M12.

[0978] Matrix mixture M13

[0979] The nematic LC mixture was prepared as follows:

[0980]

[0981] Mixture Example S13 (Stabilized with a Compound of Formula H-3-7)

[0982] The nematic LC mixture according to the invention was formulated as follows:

[0983] Mixture M13 99.9wt.-% Compounds having formula H-3-7 1 000ppm

[0984] Compared to the unstabilized mixture M13, the addition of 1 000 ppm of the compound of formula H-3-7 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M13.

[0985]

[0986] Matrix mixture M14

[0987] The nematic LC mixture was prepared as follows:

[0988]

[0989] Mixture Example S14 (Stabilized with a Compound of Formula H-3-8) The nematic LC mixture according to the invention was formulated as follows:

[0990] Mixture M14 99.9wt.-% Compounds having formula H-3-8 1 000ppm

[0991] Compared to the unstabilized mixture M14, the addition of 1 000 ppm of the compound of formula H-3-8 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M14.

[0992]

[0993] Base mixture M15

[0994] The nematic LC mixture was prepared as follows:

[0995]

[0996] Mixture Example S15 (Stabilized with a Compound of Formula H-3-9)

[0997] The nematic LC mixture according to the invention was formulated as follows:

[0998] Mixture M15 99.995wt.-% Compounds having the formula H-3-9 50ppm

[0999] Compared to the unstabilized mixture M15, the addition of 50 ppm of the compound of formula H-3-9 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M15.

[1000]

[1001] Matrix mixture M16

[1002] The nematic LC mixture was prepared as follows:

[1003]

[1004] Mixture Example S16 (Stabilized with a Compound of Formula H-3-11)

[1005] The nematic LC mixture according to the invention was formulated as follows:

[1006] Mixture M16 99.995wt.-% Compounds having the formula H-3-11 50ppm

[1007] Compared to the unstabilized mixture M16, the addition of 50 ppm of the compound having the formula H-3-11 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M16.

[1008]

[1009] Base mixture M17

[1010] The nematic LC mixture was prepared as follows:

[1011]

[1012] Mixture Example S17 (Stabilized with a Compound of Formula H-3-10)

[1013] The nematic LC mixture according to the invention was formulated as follows:

[1014] Mixture M17 99.995wt.-% Compounds having the formula H-3-10 50ppm

[1015] Compared to the unstabilized mixture M17, the addition of 50 ppm of the compound having the formula H-3-10 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M17.

[1016]

[1017] Base mixture M18

[1018] The nematic LC mixture was prepared as follows:

[1019]

[1020] Mixture Example S18 (Stabilized with a Compound of Formula H-3-12)

[1021] The nematic LC mixture according to the invention was formulated as follows:

[1022] Mixture M18 99.995wt.-% Compounds having the formula H-3-12 50ppm

[1023] Compared to the unstabilized mixture M18, the addition of 50 ppm of the compound having the formula H-3-12 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M18.

[1024]

[1025] Base mixture M19

[1026] The nematic LC mixture was prepared as follows:

[1027]

[1028] Mixture Example S19 (Stabilized with a Compound of Formula ST-2-3)

[1029] The nematic LC mixture according to the invention was formulated as follows:

[1030] Mixture M19 99.95wt.-% Compounds having the formula ST-2-3 500ppm

[1031] Addition of 500 ppm of compound with ST-2-3 significantly improved the VHR after UV exposure compared to the unstabilized mixture M19 100 , without affecting the remaining physical properties of mixture M19.

[1032] Base mixture M20

[1033] The nematic LC mixture was prepared as follows:

[1034]

[1035] Mixture Example S20 (Stabilized with a Compound of Formula ST-2-3)

[1036] The nematic LC mixture according to the invention was formulated as follows:

[1037] Mixture M20 99.96wt.-% Compounds having the formula ST-2-3 400ppm

[1038] Compared to the unstabilized mixture M20, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M20.

[1039] Example M21 (present invention)

[1040] The nematic LC mixture was prepared as follows:

[1041]

[1042] Mixture Example S21 (Stabilized with a Compound of Formula ST-2-3)

[1043] The nematic LC mixture according to the invention was formulated as follows:

[1044] Mixture M21 99.96wt.-% Compounds having the formula ST-2-3 400ppm

[1045] Compared to the unstabilized mixture M21, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M21.

[1046] Example M22 (present invention)

[1047] The nematic LC medium was prepared as follows:

[1048]

[1049] Mixture Example S22 (Stabilized with a Compound of Formula ST-2-3)

[1050] The nematic LC mixture according to the invention was formulated as follows:

[1051] Mixture M22 99.95wt.-% Compounds having the formula ST-2-3 500ppm

[1052] Compared to the unstabilized mixture M22, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1053] Example M23 (present invention)

[1054] The nematic LC medium was prepared as follows:

[1055]

[1056] Mixture Example S23 (Stabilized with a Compound of Formula ST-2-3)

[1057] The nematic LC mixture according to the invention was formulated as follows:

[1058] Mixture M23 99.9wt.-% Compounds having the formula ST-2-3 500ppm

[1059] Compared to the unstabilized mixture M23, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1060] Embodiment M24 (present invention)

[1061] The nematic LC medium was prepared as follows:

[1062]

[1063] Mixture Example S24 (Stabilized with a Compound of Formula H-3-6)

[1064] The nematic LC mixture according to the invention was formulated as follows:

[1065] Mixture M24 99.995wt.-% Compounds having the formula H-3-6 50ppm

[1066] Compared to the unstabilized mixture M24, the addition of 50 ppm of the compound of formula H-3-6 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M24.

[1067]

[1068] Embodiment M25 (present invention)

[1069] The nematic LC medium was prepared as follows:

[1070]

[1071] Mixture Example S25 (Stabilized with a Compound of Formula H-3-13) The nematic LC mixture according to the invention was formulated as follows:

[1072] Mixture M25 99.993wt.-% Compounds having the formula H-3-13 70ppm

[1073] Compared to the unstabilized mixture M25, the addition of 70 ppm of the compound having the formula H-3-13 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M25.

[1074]

[1075] Example M26 (present invention)

[1076] The nematic LC medium was prepared as follows:

[1077]

[1078] Mixture Example S26 (Stabilized with a Compound of Formula H-3-14)

[1079] The nematic LC mixture according to the invention was formulated as follows:

[1080] Mixture M26 99.99wt.-% Compounds having the formula H-3-14 100ppm

[1081] Compared to the unstabilized mixture M26, the addition of 100 ppm of the compound having the formula H-3-14 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M26.

[1082]

[1083] Example M27 (present invention)

[1084] The nematic LC medium was prepared as follows:

[1085]

[1086] Mixture Example S27 (stabilized with a compound having formula H-3-15) The nematic LC mixture according to the invention was formulated as follows:

[1087] Mixture M27 99.99wt.-% Compounds having the formula H-3-15 100ppm

[1088] Compared to the unstabilized mixture M27, the addition of 100 ppm of the compound having the formula H-3-15 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M27.

[1089]

[1090] Embodiment M28 (present invention)

[1091] The nematic LC medium was prepared as follows:

[1092]

[1093] Mixture Example S28 (stabilized with a compound having formula H-3-16)

[1094] The nematic LC mixture according to the invention was formulated as follows:

[1095] Mixture M28 99.99wt.-% Compounds having the formula H-3-16 100ppm

[1096] Compared to the unstabilized mixture M28, the addition of 100 ppm of the compound having the formula H-3-16 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M28.

[1097] Embodiment M29 (present invention)

[1098] The nematic LC medium was prepared as follows:

[1099]

[1100] Mixture Example S29 (stabilized with a compound having formula H-3-17)

[1101] The nematic LC mixture according to the invention was formulated as follows:

[1102] Mixture M29 99.99wt.-% Compounds having the formula H-3-17 100ppm

[1103] Compared to the unstabilized mixture M29, the addition of 100 ppm of the compound having the formula H-3-17 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M29.

[1104]

[1105] Embodiment M30 (present invention)

[1106] The nematic LC medium was prepared as follows:

[1107]

[1108] Mixture Example S30 (stabilized with a compound having formula H-3-18)

[1109] The nematic LC mixture according to the invention was formulated as follows:

[1110] Mixture M30 99.995wt.-% Compounds having the formula H-3-18 50ppm

[1111] Compared to the unstabilized mixture M30, the addition of 50 ppm of the compound having the formula H-3-18 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M30.

[1112] Example M31 (present invention)

[1113] The nematic LC medium was prepared as follows:

[1114]

[1115] Mixture Example S31 (Stabilized with a Compound of Formula H-3-19)

[1116] The nematic LC mixture according to the invention was formulated as follows:

[1117] Mixture M31 99.995wt.-% Compounds having the formula H-3-19 50ppm

[1118] Compared to the unstabilized mixture M31, the addition of 50 ppm of the compound having the formula H-3-19 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M31.

[1119]

[1120] Embodiment M32 (present invention)

[1121] The nematic LC medium was prepared as follows:

[1122]

[1123] Mixture Example S32 (Stabilized with a Compound of Formula ST-4-1)

[1124] The nematic LC mixture according to the invention was formulated as follows:

[1125] Mixture M32 99.95wt.-% Compounds having the formula ST-4-1 500ppm

[1126] Compared to the unstabilized mixture M32, the addition of 500 ppm of the compound of formula ST-4-1 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture M32.

[1127]

[1128] Embodiment M33 (present invention)

[1129] The nematic LC medium was prepared as follows:

[1130]

[1131] Mixture Example S33 (Stabilized with a Compound of Formula ST-4-2)

[1132] The nematic LC mixture according to the invention was formulated as follows:

[1133] Mixture M33 99.92wt.-% Compounds having the formula ST-4-2 800ppm

[1134] Compared to the unstabilized mixture M33, the addition of 800 ppm of the compound of formula ST-4-2 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M33.

[1135]

[1136] Embodiment M34 (present invention)

[1137] The nematic LC medium was prepared as follows:

[1138]

[1139] Mixture Example S34 (Stabilized with a Compound of Formula H-3-20)

[1140] The nematic LC mixture according to the invention was formulated as follows:

[1141] Mixture M34 99.995wt.-% Compounds having the formula H-3-20 50ppm

[1142] Compared to the unstabilized mixture M34, the addition of 50 ppm of the compound having the formula H-3-20 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M34.

[1143]

[1144] Example M35 (present invention)

[1145] The nematic LC medium was prepared as follows:

[1146]

[1147] Mixture Example S35 (Stabilized with a Compound of Formula H-3-21)

[1148] The nematic LC mixture according to the invention was formulated as follows:

[1149] Mixture M35 99.995wt.-% Compounds having the formula H-3-21 50ppm

[1150] Compared to the unstabilized mixture M35, the addition of 50 ppm of the compound having the formula H-3-21 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M35.

[1151]

[1152] Embodiment M36 (present invention)

[1153] The nematic LC medium was prepared as follows:

[1154]

[1155] Mixture Example S36 (Stabilized with Compounds of Formula H-3-1 and ST-4-2)

[1156] The nematic LC mixture according to the invention was formulated as follows:

[1157] Mixture M36 99.87wt.-% Compounds having formula H-3-1 800ppm Compounds having the formula ST-4-2 500ppm

[1158] Compared to the unstabilized mixture M36, the addition of compounds of formula H-3-1 and ST-4-2 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1159] Embodiment M37 (present invention)

[1160] The nematic LC medium was prepared as follows:

[1161]

[1162]

[1163] Mixture Example S37 (Stabilized with Compounds of Formula H-3-2 and ST-4-2) The nematic LC mixture according to the invention was formulated as follows:

[1164] Mixture M37 99.934wt.-% Compounds having formula H-3-2 60ppm Compounds having the formula ST-4-2 600ppm

[1165] Compared to the unstabilized mixture M37, the addition of compounds of formula H-3-2 and ST-4-2 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1166] Embodiment M38 (present invention)

[1167] The nematic LC medium was prepared as follows:

[1168]

[1169]

[1170] Mixture Example S38 (Stabilized with Compounds of Formula H-3-1 and ST-2-3)

[1171] The nematic LC mixture according to the invention was formulated as follows:

[1172] Mixture M38 99.89wt.-% Compounds having formula H-3-1 800ppm Compounds having the formula ST-2-3 300ppm

[1173] Compared to the unstabilized mixture M38, the addition of compounds of formula H-3-1 and ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1174] Embodiment M39 (present invention)

[1175] The nematic LC medium was prepared as follows:

[1176]

[1177]

[1178] Mixture Example S39 (Stabilized with Compounds of Formula H-3-4 and ST-2-3)

[1179] The nematic LC mixture according to the invention was formulated as follows:

[1180] Mixture M39 99.972wt.-% Compounds having formula H-3-4 80ppm Compounds having the formula ST-2-3 200ppm

[1181] Compared to the unstabilized mixture M39, the addition of compounds of formula H-3-4 and ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

[1182] Matrix mixture M40

[1183] The nematic LC mixture was prepared as follows:

[1184]

[1185] Mixture Example S40 (Stabilized with Compounds of Formula H-3-1 and ST-1-3) The nematic LC mixture according to the invention was formulated as follows:

[1186] Mixture M40 99.89wt.-% Compounds having formula H-3-1 800ppm Compounds having the formula ST-1-3 300ppm

[1187] Compared to the unstabilized mixture M40, the addition of compounds of formula H-3-1 and ST-1-3 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of the mixture.

Claims

1. A liquid crystal medium, characterized in that: It comprises one or more compounds having formula G and one or more compounds having formula U The substituents have the following meanings: R 1 , R 2 Each independently represents a H atom, a halogen atom R 4 and R 5 , -CN, -SCN, -NCS, alkyl or alkoxy having 1 to 12 C atoms or alkenyl or alkenyloxy having 2 to 12 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms may be replaced by halogen atoms, or cycloalkyl or cycloalkoxy having 3 to 12 C atoms, in which one or more H atoms may be replaced by halogen atoms; R 3 and R 6 each independently of one another represents an H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms, wherein one or more non-adjacent CH2 groups are optionally substituted by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another; A 1 To A 4 each independently of one another represents phenylene-1,4-diyl, wherein, in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3, cyclohexane-1,4-diyl, wherein, in addition, one or two non-adjacent CH2 groups may be replaced independently of one another by O and / or S and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dihydropyran-2,5-diyl. Alkane-2,5-diyl; Z 1 To Z 4 Each independently represents -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-, -C2F4-, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or a single bond; k, l, m, and n each independently represent 0, 1, 2, or 3.

2. The medium according to claim 1, characterized in that In the formulas G and U R 1 , R 2 , as defined in claim 1; R 4 and R 5 A 1 and A 3 Each independently represents a phenylene-1,4-diyl group, a cyclohexane-1,4-diyl group, a cyclohexene-1,4-diyl group, a tetrahydropyran-2,5-diyl group or a 1,3-diyl group. Alkane-2,5-diyl; Z 1 and Z 3 Each independently of one another represents a single bond; k and m each independently represent 1; and l and n each independently represent 0.

3. The medium according to claim 1 or 2, characterized in that The compounds of formula G and U are selected from the group consisting of: Where R 1 , R 2 , R 3 , R 4 , R 5 and R 6 As defined in claim 1.

4. The medium according to one or more of claims 1 to 3, characterized in that The medium comprises one or more compounds selected from the group consisting of: The substituents have the following meanings: R 0 The invention has the following characteristics: 1 , R 4 and R 5 One of the meanings given; X 0 With respect to X in claim 4 0 One of the meanings given; L 1 To L 6 Each independently represents H, F or Cl; Y 0 Each independently represents H or CH3.

5. The medium according to claim 4, characterized in that The one or more compounds of formula II are selected from the following sub-formulae: Where R 0 and X 0 has the meaning given in formula II.

6. The medium according to claim 4, characterized in that The one or more compounds of formula III are selected from the following sub-formulae: Where R 0 and X 0 has the meaning given in formula III.

7. The medium according to one or more of claims 1 to 6, characterized in that The medium further comprises one or more compounds selected from the group consisting of: Where R 0 , X 0 , L 1 , L 2 and Y 0 has the meaning given in claim 5; L 3 and L 4 Each independently has a 1 the meaning given; Z 0 represents -C2H4-, -(CH2)4-, -CH=CH-, -CF=CF-, -C2F4-, -CH2CF2-, -CF2CH2-, -CH2O-, -OCH2-, -COO-, -CF2O- or -OCF2-, in Formulas V and VI, also represents a single bond; and s represents 0 or 1.

8. The medium according to one or more of claims 1 to 7, characterized in that It comprises one or more compounds selected from the group consisting of: The substituents have the following meanings: "Alkyl" and "alkyl*" each independently represent an alkyl group having 1 to 6 C atoms; "Alkenyl" and "alkenyl*" each independently of one another represent an alkenyl radical having 2 to 6 C atoms.

9. The medium according to one or more of claims 1 to 8, characterized in that The medium comprises one or more compounds selected from the group consisting of: in R 1 and R 2 each independently of one another represents an alkyl, alkoxy, oxaalkyl or fluoroalkyl group each having 1 to 6 C atoms or an alkenyl group having 2 to 6 C atoms; and L 1 and L each independently represent H, F or Cl.

10. The medium according to one or more of claims 1 to 9, characterized in that The medium further comprises one or more compounds selected from the group consisting of compounds of formula LP1 and LP2 The substituents have the following meanings: R 0 The invention has the following characteristics for R 1 , R 4 and R 5 One of the meanings given; R 2 The invention has the following characteristics: 2 One of the meanings given; L 1 and L 2 Each independently represents H, F or Cl; Y 0 With formula U and G for R 3 and R 6 One of the meanings given, preferably H or CH3; X 0 represents an F atom, CN, SCN, NCS or an alkyl or alkoxy group having 1 to 6 C atoms or an alkenyl or alkenyloxy group having 2 to 6 C atoms, wherein one or more H atoms are replaced by F atoms.

11. The medium according to one or more of claims 1 to 10, characterized in that The medium comprises one or more compounds selected from the group consisting of Where R 0 , X 0 , Y 0 and L 1-4 Each independently of one another has one of the meanings indicated in claim 5.

12. The medium according to one or more of claims 1 to 11, characterized in that The medium comprises one or more compounds selected from the group consisting of: in R 1 , X 0 and Y 0 Respectively have the following characteristics for R in claim 5 0 , X 0 and Y 0 The meaning indicated.

13. The medium according to one or more of claims 1 to 12, characterized in that The medium comprises one or more compounds having the formula H in R 11 each independently of one another represents an H atom, F, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or, if present, a plurality of -CH2- groups may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and one or, if present, a plurality of -CH2- groups may be replaced by -CH=CH- or -C≡C-, and in which one or a plurality of H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Instead, R 12 each independently represents an H atom, an alkyl group having 1 to 20 C atoms, in which one -CH2- group or multiple -CH2- groups can be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be replaced by -O-, a hydrocarbon group containing cycloalkyl or alkylcycloalkyl units, in which one -CH2- group or multiple -CH2- groups can be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups cannot be replaced by -O-, and in which one H atom or multiple H atoms can be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 substituted, or aromatic or heteroaromatic hydrocarbon radicals in which one or more H atoms may be replaced by OR 13 、N(R 13 )(R 14 ) or R 15 Instead, R 13 and R 14 each independently of one another represents an alkyl or acyl group having 1 to 10 C atoms or an aromatic hydrocarbon or carboxylic acid group having 6 to 12 C atoms, R 15 each independently of one another represents an alkyl group having 1 to 10 C atoms, in which one -CH2- group or a plurality of -CH2- groups may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, R 16 each independently represents an H atom, an alkyl or alkoxy group having 1 to 10 C atoms, an O-cycloalkyl group having 3 to 12 C atoms, an O ● or OH, S 11 and S 12 each independently of one another represents an alkylene radical having 1 to 20 C atoms, in which one -CH2- group or, if present, a plurality of -CH2- groups may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-, and in which one H atom or a plurality of H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Replace, or represent a single bond, Y 11 To Y 14 each independently represents a methyl group or an ethyl group, X 11 Represents C, Z 11 To Z 14 Each independently represents -O-, -(C=O)-, -O-(C=O)-, -(C=O)-O-, -O-(C=O)-O-, -(NR 13 )-、-NR 13 -(C=O)- or a single bond, if S 11 is a single bond; Z 11 and Z 12 If the two are different, it means -O-; if S 12 is a single bond, then Z 13 and Z 14 If both do not represent -O-, and if q represents 0, then Z 12 and Z 13 The two are different at the same time, which means -O-. p means 1 or 2, q represents 0 or 1, o represents (3-p), n represents an integer from 1 to 10, m represents an integer from 0 to 8, wherein n*p represents an integer from 1 to 10, preferably from 3 to 8, and 14. The medium according to one or more of claims 1 to 13, characterized in that The medium comprises one or more compounds having the formula ST: The substituents have the following meanings: express X 21 , X 22 Each independently represents -O-, -CH2-, -CHR 23 -or-NR 23 -, R 21 and R 22 each independently of one another represents an H atom or an alkyl or alkoxy group having 1 to 12 C atoms, an alkenyl, alkynyl, alkenyloxy or alkoxyalkyl group having 2 to 12 C atoms or a cycloalkyl group having 3 to 12 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-substituted in such a way that the O atoms are not directly connected to one another and in which one or more H atoms can be replaced by halogen atoms, or cycloalkyl or cycloalkoxy having 3 to 12 C atoms, in which one or more H atoms can be replaced by halogen atoms, R 23 represents an H atom, an alkyl group or an alkoxy group having 1 to 10 C atoms, r represents 0 or 1.

15. The medium according to one or more of claims 1 to 12, characterized in that The medium comprises one or more additives selected from the group consisting of polymerization initiators, inhibitors, surfactants, light stabilizers, antioxidants, microparticles, free radical scavengers, nanoparticles, pleochroic dyes and chiral dopants.

16. A method for producing a liquid-crystalline medium according to one or more of claims 1 to 15, characterized in that One or more compounds of formula G and one or more compounds of formula U are mixed with one or more mesogenic compounds and optionally one or more polymerizable compounds and / or one or more additives.

17. Use of a liquid-crystalline medium according to one or more of claims 1 to 15 for electro-optical purposes.

18. An electro-optical liquid crystal display or an AR / VR headset comprising a liquid crystal medium according to one or more of claims 1 to 15.

19. The electro-optical liquid crystal display according to claim 18, characterized in that: It is a TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, SA-HB-FFS, SA-XB-FS, polymer-stabilized SA-HB-FFS, polymer-stabilized SA-XB-FFS, positive VA or positive PS-VA display.

20. The electro-optical liquid crystal display according to claim 18, characterized in that: It is a FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, IPS or PS-IPS display.

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