Liquid crystal medium

Abstract

The present invention relates to liquid crystal (LC) media and energy efficient liquid crystal displays (LCDs) containing these media, in particular to displays 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

[0001] The present invention relates to liquid crystal (LC) media and energy-efficient liquid crystal displays (LCDs) containing these media, in particular to displays 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 positive dielectric anisotropy.

[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 include twisted nematic (TN), super twisted nematic (STN), optically compensated bend (OCB), and electrically controlled birefringence (ECB) modes, as well as their various variations, and other modes. All of these modes utilize an electric field generated substantially perpendicular to the substrate and LC layer.

[0003] In addition to these modes, there are also electro-optic modes, which use an electric field that is substantially parallel to the substrate or LC layer. For example, WO 91 / 10936 discloses an LC display 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 is therefore known as an in-plane switching (IPS) display. The principles of operation of such displays are described, for example, by R. A. Soref in Journal of Applied Physics, Vol. 45, No. 12, pp. 5466-5468 (1974).

[0004] IPS displays contain an LC layer between two planarly oriented substrates. Two electrodes are provided on only one of the two substrates and preferably have an interdigitated, comb-shaped 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 results in 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, inter alia, SH Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, 1028), which comprise two electrodes on the same substrate, one of which is structured in a comb-like manner and the other unstructured. This results in a strong so-called "fringe field," i.e., a strong electric field close to the electrode edges and an electric field with both a strong vertical component and a strong horizontal component throughout the liquid crystal cell. FFS displays have a low viewing angle dependence of the contrast. FFS displays generally comprise an LC medium with positive dielectric anisotropy and an alignment layer, generally of 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 modern desktop monitors, televisions, and multimedia applications. The LC media according to the invention are preferably used in these types of displays. Generally, positive dielectric LC media with relatively 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 less are also used in IPS displays.

[0009] Further improvements are achieved through the HB-FFS mode. One of the unique features of the HB-FFS mode is that it allows for 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 with low dielectric anisotropy.

[0011] Liquid crystal compositions suitable for LCDs, and in particular for FFS and IPS displays, are known from 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 28 106, DE 195 28 107, WO 96 / 23 851, and WO 96 / 28 521. 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 are necessary both in terms of operating properties and shelf life.

[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 typically addressed by integrated non-linear active elements (e.g., thin film transistors (TFTs)), while in the case of passive matrix displays, the individual pixels are typically addressed by multiplexing methods known in the art.

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

[0014] Typical applications of in-plane switching (IPS) and fringe field switching (FFS) technologies are monitors, notebook computers, TVs, mobile phones, tablet PCs, etc.

[0015] Both IPS and FFS technologies have certain advantages over other LCD technologies, such as vertical alignment (VA) technology, such as wide viewing angle dependence of contrast ratio.

[0016] The provision of alternative LC media and their use in displays with high transmittance, a good black state and high contrast are major challenges for modern FFS and IPS applications. In addition, modern applications also require good low-temperature stability and fast addressing times.

[0017] So far, it has not been possible to design a material with high contrast (e.g. high elastic constants K1 and K av ), low-temperature stability, and suitable LC media with low response times. Therefore, the overall image quality in such devices still needs to be further improved.

[0018] It is an object of the present invention to provide LC media, in particular for energy-saving FFS and IPS displays, and also for TN, positive VA or STN displays, and in particular for active-matrix displays such as those addressed by TFTs, which LC media do not exhibit the disadvantages indicated above, or exhibit them only to a lesser extent, and have a high average elastic constant K av As well as a low response time parameter (γ1 / K1), low rotational viscosity, and relatively low birefringence Δn. Furthermore, the LC medium is required to have high specific resistance, low threshold voltage, high dielectric anisotropy, good low-temperature stability (LTS), fast response time, and high brightness. In the case of FFS displays, further optimization of response time, contrast, brightness, and reliability is required. However, it has been found that existing LC materials are generally unable to simultaneously meet all of these requirements.

[0019] Surprisingly, the above technical problem is solved by providing LC media as described and claimed below.

[0020] It has now been found that, surprisingly, LC media according to the invention containing a combination of compounds of the formula I, LP1 and / or LP2

[0021]

[0022] wherein each substituent is as specified in claim 1,

[0023] Shows several significant improvements, especially when used in FFS mode displays, such as high average elastic constant K av , low response time parameter (γ1 / K1) and low rotational viscosity and good solubility, and achieve fast response time.

[0024] Furthermore, the LC media according to the present invention have high-definition bright spots, excellent low-temperature stability (LTS), and offer optimal moving image quality and improved overall image quality, in particular high contrast.

[0025] The present invention relates to an LC medium, characterized in that the LC medium comprises one or more compounds of formula I

[0026]

[0027] where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another:

[0028] R 11 and R 12 Each independently of one another represents an H atom, an alkyl or alkoxy group having 1 to 12 C atoms, or an alkenyl or alkenyloxy group having 2 to 12 C atoms, wherein one or more 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom, or a cycloalkyl or cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, preferably a cyclopentyl or cyclopentyloxy group,

[0029] Z 1 represents a single bond, -CH2-CH2- or -COO-;

[0030] and

[0031] One or more compounds selected from the group consisting of the following formulae LP1 and LP2:

[0032]

[0033] where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another:

[0034] Preferably

[0035] Most preferably

[0036]

[0037] R 0 is an alkyl or alkoxy radical having 1 to 12 C atoms, or an alkenyl radical having 2 to 12 C atoms, wherein one or more CH2 groups are optionally substituted by: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom,

[0038] R 2 is an alkyl or alkoxy radical having 1 to 6 C atoms, wherein one or more CH2 groups are optionally substituted by: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom,

[0039] X 2 is an F atom 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 an F atom,

[0040] L 1 and L 2 are independently H, F or Cl,

[0041] Y 0 is H or CH3, and

[0042] n and m independently represent 0, 1 or 2.

[0043] The LC media according to the invention are particularly suitable for LC displays in the FFS, HB-FFS, XB-FFS and IPS modes, which are based on positive dielectric liquid crystals and polymer-stabilized variants thereof.

[0044] The invention further relates to the use of the LC media 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.

[0045] 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.

[0046] In this application, all atoms also include their isotopes. In some embodiments, one or more hydrogen atoms (H) may be optionally replaced by deuterium (D); a higher degree of deuteration enables or simplifies analytical determination of the compound, especially in the case of low concentrations.

[0047] In formulas I, LP1 and LP2, if R 0 、R 11 、R 12 and R 2 If R represents alkyl and / or alkoxy, this may be linear or branched. It is preferably linear, has 2, 3, 4, 5 or 6 carbon atoms, and preferably represents ethyl, propyl, butyl, pentyl, hexyl, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy, as well as methyl or methoxy. 0 Preferably it represents straight-chain alkyl having 1 to 6 C atoms or alkenyl having 2 to 6 C atoms.

[0048] Oxaalkyl preferably represents straight-chain 2-oxapropyl (=methoxymethyl), 2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-oxapentyl, 3-oxapentyl or 4-oxapentyl, 2-oxahexyl, 3-oxahexyl, 4-oxahexyl or 5-oxahexyl.

[0049] If R0 、R 11 、R 12 or R 2 represents an alkoxy group or an oxaalkyl group, it may also contain one or more additional oxygen atoms, with the proviso that the oxygen atoms are not directly bonded to one another.

[0050] In another preferred embodiment, R 0 、R 11 、R 12 and R 2 One or more of are selected from the group consisting of: -S 1 -F, -OS 1 -F, -O-S1-O-S2, where S 1 C 1-12 Alkylene or C 2-12 Alkenylene and S 2 H, C 1-12 Alkyl or C 2-12 Alkenyl, and very preferably R 0 、R 11 、R 12 and R 2 One or more of are selected from the group consisting of: -OCH2OCH3, -O(CH2)2OCH3, -O(CH2)3OCH3, -O(CH2)4OCH3, -O(CH2)2F, -O(CH2)3F, -O(CH2)4F.

[0051] If R 0 、R 11 、R 12 or R 2If alkylene radicals denote an alkenyl radical, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Thus, it denotes in particular 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.

[0052] If R 0 、R 11 、R 12 or R 2 If represents an alkyl or alkenyl group which is at least monosubstituted by halogen, this group is preferably straight-chain, and the halogen is preferably F or Cl. In the case of polysubstitution, the halogen is preferably F. The resulting groups also include perfluorinated groups. In the case of monosubstitution, the fluorine or chlorine substituent can be located in any desired position, but is preferably located in the ω-position.

[0053] In formula LP2, X 2 Preferably it is an F atom or a monofluorinated or polyfluorinated alkyl or alkoxy group having 1, 2 or 3 C atoms, or a monofluorinated or polyfluorinated alkenyl group having 2 or 3 C atoms. 2 Particularly preferred are F, CF3, CHF2, OCF3, OCHF2, OCFHCF3, OCFHCHF2, OCFHCHF2, OCF2CH3, OCF2CHF2, OCF2CHF2, OCF2CF2CHF2, OCF2CF2CHF2, OCFHCF2CF3, OCFHCF2CHF2, OCF2CF2CF3, OCH═CF2 or CH═CF2, very particularly preferably F or CF3, furthermore OCF3, OCF═CF2, OCHF2 or OCH═CF2.

[0054] In the compounds of formula I and its subformulae, R 11 and R 12Preferably represents straight-chain alkyl or alkoxy having 1 to 6 C atoms or alkenyl having 2 to 6 C atoms, very preferably represents methyl, ethyl or propyl, most preferably represents n-propyl, and also vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl and 1-pentenyl. Preferred compounds of formula I are those in which Z 1 Those compounds that represent single bonds.

[0055] In a preferred embodiment, the compound of formula I can be selected from those of the following sub-formulae I-1 to I-3:

[0056]

[0057] in

[0058] R 11 and R 12 Each independently of one another represents an H atom, 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 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom (preferably an F atom), or a cycloalkyl or cycloalkoxy group having 3 to 6 C atoms, in which one or more H atoms may be replaced by a halogen atom, preferably a cyclopentyl or cyclopentyloxy group.

[0059] Although the substituent R in formula I 11 and R 12 The choice of is not particularly limited, but R 11 and R 12 It is particularly advantageous to be an alkyl or cycloalkyl radical having 1 to 6 C atoms, wherein R 1 It is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and particularly preferably cyclopentyl.

[0060] R 11 and R 12 It may also be advantageous to choose from unbranched alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl and 5-hexenyl.

[0061] In particular, it has been shown to be very advantageous to select compounds of the following formula I:

[0062]

[0063]

[0064] Among them, "alkyl" and "alkyl*" represent C 1-6 alkyl,

[0065] "Cycloalkyl" means C 3-6 Cycloalkyl.

[0066] The use of compounds of sub-formula I-1, in particular those of sub-formulae I-1-1 to I-1-11, is most advantageous with regard to the overall combination of characteristics of the medium obtained.

[0067] The proportion of compounds of the formula I or preferably of subformulae I-1-1 or I-1-2 thereof in the LC medium is preferably 0.5% to 20% by weight, very preferably 1% to 15% by weight, most preferably 2% to 10% by weight.

[0068] The compounds of the general formula LP1 and LP2 can be represented by one of the following:

[0069]

[0070] in

[0071] R 0 is an alkyl or alkoxy radical having 1 to 12 C atoms, wherein one or more CH2 groups are optionally substituted by: -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO-, in such a way that the O atoms are not directly bonded to one another and in which one or more H atoms may be replaced by a halogen atom, preferably alkyl having 1 to 4 C atoms, alkenyl or alkenyloxy having 2 to 6 C atoms or cycloalkyl or cycloalkyloxy having 3 to 6 C atoms, where vinyl, allyl or cyclopentyl are particularly preferred,

[0072] n represents 1, 2, 3, 4, or 5, and

[0073] m represents 1, 2, 3 or 4.

[0074] In another embodiment, one or more compounds of Formula LP1 and LP2 are described by the following Formulas LP1-1 and LP2-1:

[0075]

[0076] in

[0077] R 0is 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 groups are optionally substituted by: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom,

[0078] R 2 is an alkyl radical having 1 to 6 C atoms, wherein one or more CH2 groups are optionally substituted by: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom,

[0079] X 2 is an F atom or an alkyl or alkoxy group having 1 to 3 C atoms or an alkenyl or alkenyloxy group having 2 to 3 C atoms, wherein one or more H atoms are replaced by an F atom, and

[0080] Y 0 is H or CH3.

[0081] Particularly preferred compounds of formula LP1 are those selected from the group consisting of the following subformulae:

[0082]

[0083]

[0084] where Y 0 It is H or CH3, preferably H.

[0085] The compounds of formula LP1-1a, LP1-1b and LP1-1c are particularly preferred, and the compound of formula LP1-1a is most preferred.

[0086] Particularly preferred compounds of formula LP2 are those selected from the group consisting of the following subformulae:

[0087]

[0088]

[0089] where Y 0 It is H or CH3, preferably H.

[0090] The compounds of formula LP2-1a, LP2-1b, LP2-1c, LP2-1d and LP2-1i are particularly preferred, and the compound of formula LP2-1b is most preferred.

[0091] The proportion of compounds of the formula LP1 or LP2 or subformulae thereof in the LC medium is preferably from 2% to 35% by weight, very preferably from 3% to 30% by weight, most preferably from 4% to 20% by weight.

[0092] Preferably, the LC medium contains 1, 2 or 3 compounds of the formula LP1 or LP2 or subformulae thereof. In a particularly preferred embodiment, the LC medium comprises at least one compound of the formula LP1 and at least one compound of the formula LP2.

[0093] Other components

[0094] In a preferred embodiment, the LC medium may also comprise one or more compounds selected from the following formulae II and III:

[0095]

[0096] wherein the individual substituents independently of one another and identically or differently on each occurrence have the following meanings:

[0097] for

[0098] for

[0099] R 0 With R 11 and R 12 One of the meanings given,

[0100] X 0 are independently of one another F, Cl, halogenated alkyl, halogenated alkenyl, halogenated alkoxy or halogenated alkenyloxy with up to 6 C atoms,

[0101] L 1-6 are independently H or F, and

[0102] Y 0 is H or CH3.

[0103] Preferred compounds of formula II and III are those wherein Y 0 Those compounds where H

[0104] Further preferred compounds of formula II and III are those wherein R 0 represents an alkyl radical having 1 to 6 C atoms, very preferably an ethyl or propyl radical, and X 0represents F or OCF3, very preferably those compounds where F is present.

[0105] In a preferred embodiment, the LC medium comprises one or more compounds of formula II selected from the following subformulae:

[0106]

[0107]

[0108] where R 0 and X 0 has the meaning given in formula II.

[0109] Preferred compounds are those of the formulae II-1, II-2 and II-3, very preferably those of the formulae II-1 and II-2.

[0110] In the compounds of formulae II-1 to II-7, R 0 preferably represents an alkyl radical having 1 to 6 C atoms, very preferably an ethyl or propyl radical, and X 0 Preferably it represents F or OCF3, very preferably it represents F.

[0111] 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 CH 3 . Very preferably, the LC medium according to this preferred embodiment comprises one or more compounds of formula II selected from the following subformulae:

[0112]

[0113]

[0114] where R 0 and X 0 has the meaning given in formula II.

[0115] Preferred compounds are those of the formulae IIA-1, IIA-2 and IIA-3, very preferably those of the formulae IIA-1 and IIA-2.

[0116] In the compounds of Formulae IIA-1 to IIA-7, R 0 preferably represents an alkyl radical having 1 to 6 C atoms, very preferably an ethyl or propyl radical, and X 0 Preferably it represents F or OCF3, very preferably it represents F.

[0117] The proportion of the compound of the formula II in the LC medium is generally from 0% to 20% by weight, very preferably from 1% to 15% by weight and most preferably from 2% to 10% by weight.

[0118] In another preferred embodiment, the LC medium comprises one or more compounds of formula III selected from the following subformulae:

[0119]

[0120]

[0121]

[0122]

[0123] where R 0 and X 0 has the meaning given in formula II.

[0124] Preferred compounds are those of formula III-1, III-4, III-6, III-16, III-19 and III-20.

[0125] In the compounds of formulae III-1 to III-21, R 0 preferably represents an alkyl radical having 1 to 6 C atoms, very preferably an ethyl or propyl radical, X 0 Preferably represents F or OCF3, very preferably F, and Y 0 Preferably it represents H.

[0126] The LC medium may also contain one or more compounds of the formula III or its subformulae as described above and below, in which Y 0 is CH 3 . Very preferably, the medium according to this preferred embodiment comprises one or more compounds of formula III selected from the following subformulae:

[0127]

[0128]

[0129]

[0130]

[0131] where R 0 and X 0 has the meaning given in formula III.

[0132] Preferred compounds are those of Formula IIIA-1, IIIA-4, IIIA-6, IIIA-16, IIIA-19 and IIIA-20.

[0133] In the compounds of formula IIIA-1 to IIIA-21, R 0preferably represents an alkyl radical having 1 to 6 C atoms, very preferably an ethyl or propyl radical, X 0 Preferably represents F or OCF3, very preferably F, and Y 2 Preferably it represents F.

[0134] 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% by weight, most preferably from 20% to 40% by weight.

[0135] In a further preferred embodiment, the LC medium may additionally comprise one or more compounds selected from the following formulae:

[0136]

[0137]

[0138] in

[0139] R 0 、X 0 , L 1-4 and Y 0 has the meaning indicated in formula II and III,

[0140] 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

[0141] s represents 0 or 1.

[0142] The compound of formula IV is preferably selected from the following formulae:

[0143]

[0144]

[0145] where R 0 and X 0 have the meanings indicated in formula II and III.

[0146] R 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably it represents F or OCF3, furthermore it represents OCF=CF2 or Cl.

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

[0148]

[0149] The compound of formula IVb is preferably represented by the following formula:

[0150]

[0151] The compound of formula IVc is preferably represented by the following sub-formula:

[0152]

[0153] where R 0 has the meaning indicated in formula II and is preferably propyl or pentyl.

[0154] The compound(s) 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.

[0155] The compound of formula V is preferably selected from the following sub-formulae:

[0156]

[0157] where R 0 and X 0 has the meaning indicated in formula II.

[0158] R 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably, it represents F and OCF3, and further preferably represents OCHF2, CF3, OCF=CF2 and OCH=CF2.

[0159] The compound of formula VI is preferably selected from the following sub-formulae:

[0160]

[0161] where R 0 and X 0 has the meaning indicated in formula II.

[0162] R 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 It preferably represents F, and further represents OCF3, CF3, CF=CF2, OCHF2 and OCH=CF2.

[0163] The compound of formula VII is preferably selected from the following subformulae:

[0164]

[0165]

[0166] where R 0 and X0 has the meaning indicated in formula II.

[0167] R 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F, further represents OCF3, OCHF2 and OCH=CF2;

[0168] In some embodiments, the LC medium further comprises one or more compounds selected from the following formulae:

[0169]

[0170]

[0171] in

[0172] R 0 and X 0 Each independently of one another has one of the meanings indicated in formula II,

[0173] L 1-4 Each independently represents H or F,

[0174] Y 0 represents H or CH3, preferably H,

[0175] X 0 Preferably F, Cl, CF3, OCF3 or OCHF2,

[0176] R 0 Preferably it denotes alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

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

[0178]

[0179] where R 0 R has the meaning indicated in formula LP1. 0 Preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl, and very particularly preferably n-propyl.

[0180] The compound(s) 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.

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

[0182]

[0183] where R 0 R has the meaning indicated in formula LP1. 0 Preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl, and very particularly preferably n-propyl.

[0184] The compound(s) 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.

[0185] It is further preferred that the LC media according to the invention comprise one or more compounds of the formula XXIIIa:

[0186]

[0187] where R 0 R has the meaning indicated in formula LP1. 0 Preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl, and very particularly preferably n-propyl.

[0188] The compound(s) 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.

[0189] The medium may additionally comprise one or more compounds of formula XXIV:

[0190]

[0191] where R 0 、X 0 and L 1-6 has the meaning indicated in formula III, s represents 0 or 1, and express

[0192] In Formula XXIV, X 0 It may also represent an alkyl group having 1 to 6 C atoms or an alkoxy group having 1 to 6 C atoms. The alkyl or alkoxy group is preferably straight-chain.

[0193] R 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F;

[0194] The compound of formula XXIV is preferably selected from the following sub-formulae:

[0195]

[0196]

[0197] where R 0 、X 0 and L 1 R has the meaning indicated in formula III. 0 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F, and L 1 Preferably F;

[0198] Preferably

[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 formula:

[0201]

[0202]

[0203] where R 1 and X 0 Respectively have the formula II for R 0 and X 0 The meaning indicated. 1 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F or Cl. In formula XXIV, X 0 Very particularly preferably represents Cl.

[0204] The LC medium may optionally further comprise one or more compounds of the following formulae:

[0205]

[0206] where R 1 and X 0 Respectively have formula II for R 0 and X 0 The meaning indicated. 1 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F. 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.

[0207] The compound(s) of the formula XXVI-XXIX 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 formula XXIX.

[0208] Very preferably, the LC media according to the invention comprise one or more compounds of the formula XXIXa:

[0209]

[0210] where R 1 has the meaning indicated in formula II and preferably denotes straight-chain alkyl, in particular ethyl, n-propyl, n-butyl or n-pentyl, and very particularly preferably n-propyl.

[0211] The compound(s) of the formula XXIXa 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.

[0212] The LC medium may further comprise one or more compounds of the following pyrimidine or pyridine compounds of the formula:

[0213]

[0214] where R 1 and X 0 Respectively have formula II for R 0 and X 0 The meaning indicated. 1 Preferably represents an alkyl radical having 1 to 6 C atoms. 0 Preferably represents F. The medium according to the invention may particularly optionally comprise one or more compounds of the formula XXX-1, in which X 0 Preferably it represents F. The compound(s) of the formulae XXX-1 to XXX-3 can be used in the LC media according to the invention in amounts of 1% to 20% by weight, particularly preferably 1% to 15% by weight.

[0215] Preferably, the LC medium contains, in addition to the compounds of formula I, LP1 and / or LP2 and optionally II and / or III, one or more compounds selected from the group consisting of:

[0216]

[0217] in

[0218] "alkyl" and "alkyl*" are independently C 1-6 alkyl, and preferably denotes ethyl, propyl, butyl or pentyl, very preferably ethyl, propyl or butyl,

[0219] "Alkenyl" and "alkenyl*" preferably represent C 2-6 Compounds of formula Z1 and Z2 are particularly preferred.

[0220] Preferred compounds of formulae Z1 to Z6 are those selected from the following subformulae:

[0221]

[0222]

[0223] 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.

[0224] Preferably, the total proportion of compounds of formulae Z1, Z2, Z3, Z4, Z5 and Z6 or their subformulae (such as CC-3-V) in the medium is from 10% to 65% by weight, very preferably from 20% to 60% by weight, and most preferably from 25% to 55% by weight. In a further preferred embodiment, the compound of formula Z1-1 is used in a concentration ranging from 10% to 60% by weight, more preferably from 25% to 50% by weight, based on the total weight of the LC medium. In another preferred embodiment, the LC medium comprises a total of 50% to 70% by weight of compounds represented by formulae Z1-1 and Z4-2.

[0225] Preferably, the medium contains 1, 2 or 3 compounds selected from the group consisting of formulae Z1, Z2, Z3 and Z4 or subformulae thereof.

[0226] The LC medium may additionally comprise one or more compounds of the following general formula:

[0227]

[0228] in

[0229] R 1 and R 2 Each independently represents C 1-6 Alkyl, C 1-6 Alkoxy or C 2-6 Alkenyl.

[0230] The compound of formula XII is preferably selected from the following sub-formulae:

[0231]

[0232] Here, "alkyl" and "alkyl*" each independently represent methyl, butyl, pentyl or hexyl.

[0233] In particular, compounds of formula XIIa and XIIc are preferred. 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.

[0234] Particularly preferred compounds of formula XII are described by the following structure:

[0235]

[0236] The LC medium may additionally comprise one or more compounds selected from the following formulae:

[0237]

[0238] Among them 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, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, and preferably each independently of one another represents an alkyl group having 1 to 6 C atoms; in the compound 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.

[0239] In another preferred embodiment, the LC medium comprises one or more compounds of the following formula S:

[0240]

[0241] The substituents have the following meanings:

[0242] R 1 and R 2 Each independently of one another is an H atom, an alkyl or alkoxy group having 1 to 12 C atoms or an alkenyl or alkenyloxy group having 2 to 12 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom, or cycloalkyl or cycloalkoxy having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom;

[0243] R 3is 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 bonded to one another;

[0244] A 0 、A 1 、A 2 each independently of one another represents phenylene-1,4-diyl (in which, 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 (in which, 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-dioxane-2,5-diyl,

[0245] Z 1 and Z 2 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,

[0246] k and l each independently represent 0, 1, 2 or 3.

[0247] Preferred are compounds of formula S, wherein A 0 represents phenylene-1,4-diyl, 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, OCH3, OCHF2, CF3 or OCF3. Particularly preferred are those wherein A 0 Represents the following compound:

[0248]

[0249] More preferred

[0250] and very particularly preferably wherein

[0251] A 0 express

[0252] The presence of compounds of the formula S leads to LC media having particularly high bright spots, low rotational viscosity, a broad nematic phase, high birefringence and excellent thermal and UV stability.

[0253] Particularly preferred compounds of formula S are those selected from the following subformulae:

[0254]

[0255]

[0256] where R 1 、R 2 and R 3 has the meaning indicated in the general formula S, and L 1 To L 6 R independently represents H or F. 1 and R 2 wherein preferably represents an optionally fluorinated alkyl or alkoxy group having 1 to 12 C atoms, an optionally fluorinated alkenyl or alkynyl group having 2 to 12 C atoms, an optionally fluorinated cycloalkyl group having 3 to 12 C atoms, and R 3 Preferably it represents H or methyl.

[0257] Particularly preferred are optionally fluorinated alkyl, alkenyl or alkynyl groups having 1 to 5 C atoms. 2 Preferably, it represents F. In formula S-1-4 to formula S-1-6, L 3 and L 4 Preferably represents H. In formulas S-1-4 to S-1-6, L 3 and L 4 Preferably it represents F.

[0258] In a particularly preferred embodiment, the compound of formula S is represented by the following structure:

[0259]

[0260] in

[0261] R 1 and R 2 independently of one another represent straight-chain or branched alkyl or alkoxy groups having 1 to 7 C atoms, or alkenyl, alkenyloxy, alkoxyalkyl groups having 1 to 7 C atoms, or cycloalkyl or cycloalkoxy groups having 3 to 12 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 manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom, wherein one or more H atoms may be replaced by a halogen atom;

[0262] R 3 represents an H atom, an alkyl group having 1 to 3 C atoms or an alkenyl group having 2 to 3 C atoms, more preferably an H atom or a methyl group; and

[0263] L 1 and L 2 Each independently represents an H atom or F, preferably F.

[0264] The LC medium may further optionally comprise 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 those selected from the group consisting of the following sub-formulae:

[0265]

[0266] Therein, "alkyl" and "alkyl*" have the meanings indicated above and each independently of one another preferably denotes methyl, ethyl or propyl.

[0267] The compound of formula XIV is preferably selected from the following sub-formulae:

[0268]

[0269]

[0270] Very preferred are compounds of the formulae XIVd-1, XIVe-1, XIVe-2 and XIVe-3.

[0271] In yet another embodiment, the LC medium comprises one or more compounds of formula XVI:

[0272]

[0273] where R 1 and R 2 have the meanings indicated in formulae I and LP1, respectively, and preferably each independently of one another represent an alkyl group having 1 to 6 C atoms. L represents H or F.

[0274] Particularly preferred compounds of formula XVI are those of the following sub-formula:

[0275]

[0276]

[0277] in

[0278] "Alkyl" and "alkyl*" each independently of one another denote a straight-chain alkyl radical having 1 to 6 C atoms, in particular ethyl, propyl or pentyl, and

[0279] "Alkenyl" and "alkenyl*" each independently of one another denote straight-chain alkenyl having 2 to 6 C atoms, in particular CH2=CHC2H4, CH3CH=CHC2H4, CH2=CH and CH3CH=CH.

[0280] Particular preference is given to compounds of the formulae XVIb and XVIc. Very particular preference is given to compounds of the following sub-formulae:

[0281]

[0282]

[0283] Compounds of formula XVIc-2 are highly preferred.

[0284] The LC medium may optionally comprise one or more compounds of the formula:

[0285]

[0286] in

[0287] R 1 and R 2 have the meanings indicated in formulae I and LP1, respectively, and preferably each independently of one another represent an alkyl group having 1 to 6 C atoms. L represents H or F.

[0288] Very preferred are compounds of formula XVIIa, wherein L is H. Very preferred are compounds of formula XVIIb, wherein L is F.

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

[0290]

[0291]

[0292] Among them, L, R 1 and R 2 They have the formula LP1 for Y 0 、R 0 and R 2 The meaning indicated. 1 and R 2Preferably it denotes alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms.

[0293] In some other embodiments, the medium comprises one or more compounds of the formula:

[0294]

[0295] where R 1 and R 2 have the meanings indicated in formulae I and LP1, respectively, and preferably each independently of one another represent an alkyl group having 1 to 6 C atoms.

[0296] In a preferred embodiment according to the present invention, the LC medium contains, in addition to the compounds of formula I, LP1 and / or LP2, II and / or III, one or more compounds selected from the group consisting of formula Y and B

[0297]

[0298] where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another:

[0299] for

[0300] for

[0301] for

[0302] R 1 、R 2 With formula I for R 11 and R 12 One of the meanings given,

[0303] R 3 With R 1 One of the meanings given,

[0304] Z x , Z y is -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,

[0305] Z z is -CH2O-, -O-, -C2H4-, -OCH2- or a single bond,

[0306] Y1 is -CH2-, -O- or -S-,

[0307] L 1-4 is H, F or Cl, preferably H or F, very preferably F,

[0308] x, y are 0, 1 or 2, where x+y≤3,

[0309] z is 0 or 1,

[0310] Wherein in formula B, dibenzofuran or dibenzothienyl may be further substituted by methyl or methoxy, and

[0311] The compound of formula Y contains at least one substituent L which is F or Cl, preferably F 1-4 .

[0312] Preferably, the LC medium according to this first preferred embodiment contains one or more compounds of formula I, 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.

[0313] The LC media according to this first preferred embodiment are particularly suitable for LC displays in HB-FFS or PS-HB-FFS mode.

[0314] In the compounds of formula Y and its subformulas, R 1 and R 2 It preferably represents straight-chain alkyl or alkoxy having 1 to 6 C atoms, furthermore represents alkenyl having 2 to 6 C atoms, in particular vinyl, 1E-propenyl, 1E-butenyl, 3-butenyl, 1E-pentenyl, 3E-pentenyl or 4-pentenyl.

[0315] In the 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.

[0316] In a preferred embodiment of the present invention, the LC medium contains one or more compounds of formula Y selected from the following sub-formulae

[0317]

[0318] Among them L 1 , L 2 、R 1 、R 2 , Z x , Zy , x and y have the meanings given in formula Y or one of the preferred meanings given above in formula I,

[0319] a means 1 or 2,

[0320] b represents 0 or 1,

[0321] L 1 , L 2 represents F or Cl, preferably F, and

[0322] L 5 represents H atom or CH3,

[0323] express

[0324] express

[0325] Preferably, in the compounds of formula Y1 and Y2, L 1 and L 2 Both indicate F or L 1 and L 2 One of them represents F and the other represents Cl, or L 1 and L 2 Both indicate F or L 1 and L 2 One represents F and the other represents Cl.

[0326] Preferably, the LC medium comprises one or more compounds of formula Y1 selected from the group consisting of the following subformulae:

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334]

[0335]

[0336]

[0337]

[0338]

[0339] in

[0340] a means 1 or 2,

[0341] "alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0342] "Alkenyl" means a straight-chain alkenyl radical having 2 to 6 C atoms, and

[0343] L 5 Represents an H atom or CH3.

[0344] "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-.

[0345] 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 an H atom.

[0346] Further preferably, the LC medium comprises one or more compounds of formula Y2 selected from the group consisting of the following subformulae:

[0347]

[0348]

[0349]

[0350]

[0351]

[0352]

[0353] in

[0354] "Alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms, and

[0355] "Alkenyl" means a straight-chain alkenyl group having 2 to 6 C atoms,

[0356] (O) represents an oxygen atom or a single bond, and

[0357] L 5 represents an H atom or CH 3 , preferably an H atom.

[0358] "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-.

[0359] Very preferably, the LC medium contains one or more compounds of the formula Y2 selected from the group consisting of formulae Y2-2 and Y2-10.

[0360] The proportion of compounds of the formula Y1 or its subformulae in the LC medium is preferably from 0% to 10% by weight.

[0361] The proportion of compounds of the formula Y2 or subformulae thereof in the LC medium is preferably from 0% to 10% by weight.

[0362] 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.

[0363] 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.

[0364] In another preferred embodiment of the present invention, the LC medium contains one or more compounds of the formula Y of the following subformula:

[0365]

[0366] Among them L 1 , L 2 、R 1 and R 2 has one of the meanings given in formula Y or one of the preferred meanings given in formulas I, LP1 and LP2.

[0367] Preferred compounds of formula Y3 are selected from the group consisting of the following subformulae:

[0368]

[0369]

[0370]

[0371] in,

[0372] "alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms;

[0373] "alkenyl" and "alkenyl*" each independently represent a straight-chain alkenyl group having 2 to 6 C atoms; and

[0374] O represents an oxygen atom or a single bond.

[0375] "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-.

[0376] Particularly preferred compounds of formula Y3 are selected from the group consisting of the following subformulae:

[0377]

[0378] Here, "alkoxy" and "alkoxy*" each independently of one another preferably denote a straight-chain alkoxy group having 3, 4 or 5 C atoms.

[0379] Preferably, in the compounds of formula Y3 and its subformulae, L 1 and L 2 Both represent F. Further preferably, in the compound of formula Y3, the substituent L 1 and L 2 One represents F and the other represents Cl.

[0380] 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.

[0381] Preferably, the LC medium contains 1, 2 or 3 compounds of formula Y3 or a subformulae thereof, more preferably of formula Y3-6, very preferably of formula Y3-6A.

[0382] In yet another preferred embodiment of the present invention, the LC medium contains one or more compounds of formula Y of subformula Y4:

[0383]

[0384] where R 1 and R 2each independently of one another has one of the meanings indicated above in formula Y, and

[0385]

[0386] Each independently expresses

[0387]

[0388] Among them 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 rings G, I and K is different from unsubstituted benzene.

[0389] The most preferred compounds of formula Y4 are selected from the group consisting of the following subformulae:

[0390]

[0391]

[0392] wherein R represents a straight-chain alkyl or alkoxy group having 1 to 7 C atoms, and R* represents a straight-chain alkenyl group having 2 to 7 C atoms,

[0393] (O) represents an oxygen atom or a single bond, and

[0394] m represents an integer of 1 to 6.

[0395] R* 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-.

[0396] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

[0397] The proportion of compounds of the formula Y4 or its subformulae in the medium is preferably from 0% to 10% by weight, very preferably from 1% to 6% by weight.

[0398] Particularly preferred compounds are those of the following sub-formula:

[0399]

[0400] in

[0401] "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.

[0402] The following compounds are particularly advantageously used:

[0403]

[0404] In another preferred embodiment of the present invention, the LC medium contains one or more compounds of the formula Y selected from the group consisting of the following subformulae:

[0405]

[0406]

[0407] in

[0408] R 5 With the above in formula Y for R 1 One of the meanings indicated,

[0409] "alkyl" means a straight-chain alkyl group having 1 to 6 C atoms,

[0410] L x Indicates H or F,

[0411] d represents 0 or 1, and

[0412] z and m each independently represent an integer of 1 to 6.

[0413] The R 5 C is particularly preferred 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 formulae in an amount of ≥5% by weight.

[0414] Further preferred embodiments are indicated below:

[0415] - the LC medium comprises one or more compounds of formula Y of the following sub-formulae:

[0416]

[0417] 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.

[0418] Preferably, the substituent L 1 and L2 Both represent F. Further preferably, the substituent L 1 and L 2 One represents F and the other represents Cl.

[0419] The compound of formula LY is preferably selected from the group consisting of the following subformulae:

[0420]

[0421]

[0422] where R 1 has the meaning indicated above in formula Y, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6. R 1 Preferably 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-.

[0423] Very preferred are compounds of formula LY4.

[0424] Preferably, the medium contains 1, 2 or 3 compounds of formula LY, very preferably formula LY4.

[0425] The proportion of compounds of the formula LY or its subformulae in the medium is preferably from 1% to 10% by weight.

[0426] - the medium comprises one or more compounds of formula Y represented by the following sub-formula:

[0427]

[0428] 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.

[0429] The compound of formula AY is preferably selected from the group consisting of the following subformulae:

[0430]

[0431]

[0432] in

[0433] R 1 has the meaning indicated above,

[0434] "alkyl" means a straight-chain alkyl group having 1 to 6 C atoms,

[0435] (O) represents an oxygen atom or a single bond, and

[0436] v represents an integer from 1 to 6.

[0437] R 1 Preferably 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-.

[0438] In the compounds of formula B and its subformulas, R 1 and R 3 Preferably, it represents 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.

[0439] In a preferred embodiment of the invention, the medium contains one or more compounds of formula B selected from the following subformulae:

[0440]

[0441] Among them L 1 , L 2 、R 1 and R 3 has the meaning given in formula B.

[0442] Preferred compounds of formula B1 are selected from the following sub-formulae:

[0443]

[0444] 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 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 bonded to one another and one or more H atoms may be replaced by a halogen atom. 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 independently represents an alkyl group which is methyl, ethyl, propyl, butyl, pentyl or hexyl, which is preferably linear. Very preferably, one "alkyl" is ethyl and the other "alkyl*" is n-pentyl.

[0445] Very preferred are compounds of formula B1-2.

[0446] Preferably, the compound of formula B1-1 is selected from the group consisting of compounds of formulae B1-1-1 to B1-1-11, preferably compounds of formula B1-1-6:

[0447]

[0448]

[0449] in

[0450] "alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0451] "alkenyl" and "alkenyl*" each independently represent a straight-chain alkenyl group having 2 to 6 C atoms,

[0452] “Alkoxy” and “alkoxy*” each independently of one another represent a straight-chain alkoxy radical having 1 to 6 C atoms.

[0453] Preferably, the compound of formula B1-2 is selected from the group consisting of compounds of formulae B1-2-1 to B1-2-10, preferably compounds of formula B1-2-6:

[0454]

[0455]

[0456] in

[0457] "alkyl" and "alkyl*" each independently represent a straight-chain alkyl group having 1 to 6 C atoms,

[0458] "alkenyl" and "alkenyl*" each independently represent a straight-chain alkenyl group having 2 to 6 C atoms,

[0459] “Alkoxy” and “alkoxy*” each independently of one another represent a straight-chain alkoxy radical having 1 to 6 C atoms.

[0460] Optionally, the LC medium comprises one or more compounds of formula B1-1A and / or B1-2A:

[0461]

[0462] in

[0463] (O) represents O or a single bond,

[0464] R IIIA represents an alkyl or alkenyl group having up to 7 C atoms or a group Cy-C m H 2m+1 -,

[0465] m and n, identically or differently, are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1,

[0466] Cy denotes cycloaliphatic 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.

[0467] Alternatively or in addition to the compounds of the formulae B1-1 and B1-2, compounds of the formulae B1-1A and / or B1-2A may be comprised in the LC medium, preferably additionally.

[0468] Preferred compounds of formula B1-1A and / or B1-2A are also the following:

[0469]

[0470] wherein alkoxy represents a straight-chain alkoxy group having 1 to 6 C atoms or alternatively represents -(CH2) n F (wherein n is 2, 3, 4 or 5), preferably represents C2H4F.

[0471] 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.

[0472] Preferably, the LC medium contains 1, 2 or 3 compounds of the formula B1 or a subformulae thereof.

[0473] In a preferred embodiment of the present invention, the LC medium may comprise one or more compounds of formula B2-2:

[0474]

[0475] in

[0476] R 1 、R 3 Identically or differently represent H, alkyl or alkoxy groups having 1 to 6 C atoms, wherein one or more CH2 groups in these groups are optionally substituted independently of one another by: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a way that the O atoms are not directly bonded to one another and, in addition, wherein one or more H atoms may be replaced by halogen.

[0477] The compound of formula B2-2 is preferably selected from the group consisting of compounds of formulae B2-2-1 to B2-2-10:

[0478]

[0479]

[0480] where R 3 represents an alkyl group having 1 to 6 C atoms, preferably an ethyl, n-propyl or n-butyl group, or alternatively a cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl group, or alternatively -(CH2) n F, wherein n is 2, 3, 4 or 5, preferably C2H4F.

[0481] Particularly preferred compounds of formula B2 are selected from the following sub-formulae:

[0482]

[0483] 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.

[0484] Preferably, the LC medium contains 1, 2 or 3 compounds of the formula B2 or a subformulae thereof.

[0485] Preferred compounds of formula B3 are selected from the following sub-formulae:

[0486]

[0487] where R 1 has one of the meanings given in formula B3 and preferably represents straight-chain alkyl having 1 to 6 C atoms, very preferably represents methyl, ethyl, propyl, butyl, pentyl or hexyl, more preferably represents ethyl or propyl, most preferably represents propyl, and X 1 has one of the meanings given in formula B3 and preferably represents CF3 or OCF3.

[0488] Preferred compounds of formula B3 are selected from the following sub-formulae:

[0489]

[0490] where R 1 has one of the meanings given for 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.

[0491] The most preferred are compounds of formula B3-1-1 and B3-2-2.

[0492] In a preferred embodiment, the LC medium contains one or more compounds of the 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 dibenzothiophenyl radical is terminated by a methyl or methoxy radical, preferably by a methyl radical, preferably in the para position to the substituent F, very preferably in the para position to the substituent F (i.e. at the terminal R 2 or X 1 substituted at the meta position.

[0493] 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.

[0494] Preferably, the LC medium contains 1, 2 or 3 compounds of the formula B3 or a subformulae thereof.

[0495] 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.

[0496] Compounds of formula ST

[0497] In some preferred embodiments of the present invention, the LC medium may further comprise one or more compounds of the general formula ST:

[0498]

[0499] The substituents have the following meanings:

[0500] express

[0501] X 21 、X 22 Each independently represents -O-, -CH2-, -CHR 23 -or-NR23 -,

[0502] R 21 and R 22 each independently of one another represents an H atom or an alkyl or alkoxy radical having 1 to 12 C atoms, an alkenyl, alkynyl, alkenyloxy or alkoxyalkyl radical having 2 to 12 C atoms or a cycloalkyl radical having 3 to 12 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom, or a cycloalkyl or cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom,

[0503] R 23 represents an H atom, an alkyl group or an alkoxy group having 1 to 10 C atoms,

[0504] r represents 0 or 1.

[0505] LC media comprising compounds of the following subformulae ST-1, ST-2 and ST-3 exhibit particularly high long-term thermal and UV stability:

[0506]

[0507]

[0508] The substituents have the following meanings:

[0509] express

[0510] 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

[0511] r represents 0 or 1.

[0512] In a particularly preferred embodiment, the compound of the general formula ST can be selected from the following specific structures:

[0513]

[0514]

[0515]

[0516]

[0517] 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.

[0518] Compounds of formula H

[0519] The LC medium may optionally comprise one or more compounds of formula H:

[0520]

[0521] in

[0522] 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 more H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Alternative,

[0523] R 12 each independently of one another 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 Alternative,

[0524] 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,

[0525] R 15each independently of one another represents an alkyl group having 1 to 10 C atoms, in which one -CH2- group or multiple -CH2- groups may be replaced by -O- or -C(=O)-, but two adjacent -CH2- groups may not be replaced by -O-,

[0526] R 16 each independently of one another 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,

[0527] 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,

[0528] Y 11 To Y 14 each independently represents a methyl group or an ethyl group,

[0529] X 11 Represents C,

[0530] 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 The two do not represent -O- at the same time; and if q represents 0, then Z 12 and Z 13 The two are different at the same time, indicating -O-.

[0531] p means 1 or 2,

[0532] q represents 0 or 1,

[0533] o represents (3-p),

[0534] n represents an integer from 1 to 10,

[0535] m represents an integer from 0 to 8, where

[0536] n*p represents an integer from 1 to 10, preferably from 3 to 8, and

[0537] represents an organic moiety having (m+n) bonding sites,

[0538] In some preferred embodiments of the present invention, in the compound of formula H,

[0539] express

[0540]

[0541] express

[0542]

[0543] 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,

[0544] and / or

[0545] in

[0546] -Z 12 -S 11 -Z 11 -In each occurrence, it represents -O-, S independently of each other 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)-OS 11 -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

[0547] S 11 preferably represents an alkylene radical having 1 to 20 C atoms, and / or

[0548] R 11 If present, represents alkyl, alkoxy or H, preferably H or alkyl, and / or

[0549] R 12 represents H, methyl, ethyl, propyl, isopropyl, 3-heptyl, or cyclohexyl.

[0550] In a preferred embodiment of the present application, in the compound of formula H,

[0551]

[0552] represents a group selected from the group consisting of:

[0553]

[0554]

[0555] In a further preferred embodiment of the present application, in the compound of formula H,

[0556]

[0557] represents a group selected from the group consisting of

[0558]

[0559] In a still further preferred embodiment of the present invention, in the compounds of formula H, wherein p preferably represents 1,

[0560]

[0561] express Optimal-OS 11 -O-, -S 11 -O- or -OS 11 -, particularly preferably -OS 11 -O- or -S 11 -O-.

[0562] In a further preferred embodiment of the present invention, in the compound of formula H, the group

[0563]

[0564] represents a group selected from the following group

[0565]

[0566] 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 of formula H,

[0567]

[0568] represents a group selected from the following group

[0569]

[0570] as well as

[0571]

[0572] In a still further preferred embodiment of the present invention, which may be the same as or different from those described above, in the compound of formula H, the group

[0573]

[0574] In each occurrence, independently of each other

[0575]

[0576]

[0577] Preferred

[0578]

[0579] Compounds of the following general formulae H-1-1, H-1-2 and H-1-3 have been shown to be particularly efficient UV stabilizers in LC mixtures, in particular with regard to VHR stability:

[0580]

[0581] 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 LC mixtures upon UV exposure.

[0582] In a particularly preferred embodiment, the one or more compounds of formula H may be selected from the group consisting of compounds having the following formulae H-2-1 to H-2-6:

[0583]

[0584]

[0585]

[0586] in

[0587] R 11 each independently of one another represents an H atom, 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 more H atoms may be replaced by F, OR 13 、N(R 13 )(R 14 ) or R 15 Alternative,

[0588] R 16 represents H atom or O·,

[0589] n represents an integer from 0 to 12, and

[0590] 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 Instead, or represents a single bond.

[0591] In a preferred embodiment of the present 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:

[0592]

[0593]

[0594]

[0595]

[0596]

[0597]

[0598]

[0599]

[0600] as well as

[0601]

[0602] The preferred content of one or more compounds of the formula H in the LC medium depends inter alia on the intrinsic chemical stability of the LC medium and on the properties of the compounds of the formula H. Compounds of the formula H, in which R 16 represents O·, which is known as NO group type HALS, and is preferably used in a proportion within the range of 50 ppm to 1000 ppm, based on the weight of the LC medium. Compounds of formula H, wherein R 16 Representing H atoms, which are known as HALS of the NH group type, are advantageously used in a proportion ranging from 50 ppm to 2000 ppm, based on the weight of the LC medium.

[0603] Further preferred LC media are selected from the following preferred embodiments, including any combination thereof:

[0604] Compounds of formula I in combination with compounds of formula LP1, Z1 to Z7, II and / or III

[0605] Compounds of formula I in combination with compounds of formula LP2, Z1 to Z7, II and / or III

[0606] Compounds of formula I in combination with compounds of formula LP1, LP2, II and / or III and compounds of formula Z1 and Z4

[0607] -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 formula 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, XXXI, XXXII, XXXIII and S and subformulae thereof.

[0608] -LC medium comprising 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 formula Z1, Z2, Z3, Z4, Z5, IV, VI, XII, XIV, XVI, XVIIa, XVIIb, XVIIc, XX, LP1-1, XXIII, XXIX, XXXI and S and subformulae thereof.

[0609] The LC medium comprises one or more compounds selected from the group consisting of formulae II-1, II-2, and II-3, very preferably from the group consisting of formulae II-1 and II-2. The individual concentration of each of these compounds is preferably 2% to 15% by weight. The total concentration of these compounds is preferably 5% to 25% by weight.

[0610] The LC medium comprises one or more compounds selected from the group consisting of formulae III-1, III-4, III-6, III-16, III-19, and III-20, particularly 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 2% to 15% by weight. The total concentration of these compounds is preferably 5% to 30% by weight.

[0611] The LC medium comprises one or more compounds of the formula IV, preferably selected from the group consisting of the compounds of formula IVa or IVc, very preferably selected from the group consisting of the compounds of formula IVa-1 or IVc-1, and most preferably selected from the group consisting of the compounds of formula IVc-1. The individual concentration of each of these compounds is preferably 2% to 15% by weight. The total concentration of these compounds is preferably 5% to 20% by weight.

[0612] - 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 1% to 20% by weight. The total concentration of these compounds is preferably 5% to 20% by weight.

[0613] The LC medium comprises one or more compounds of the formula Z1, preferably selected from the 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.

[0614] The LC medium comprises one or more compounds of the formula Z2, preferably selected from the 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% by weight.

[0615] The LC medium comprises 5 to 20% by weight of a compound of the formula Z3, preferably a compound of the formula Z3-1.

[0616] The LC medium comprises 5 to 20% by weight of a compound of the formula Z4, preferably a compound of the formula Z4-1.

[0617] The LC medium comprises from 10 to 65% by weight, very preferably from 20 to 60% by weight, of the compound of the formula Z5.

[0618] The LC medium comprises one or more compounds of the formula LP1-1, preferably of the formula LP1-1a or LP2-1b, very preferably of the formula LP1-1a. The concentration of these compounds is preferably from 2% to 15% by weight.

[0619] The LC medium comprises from 1 to 15% by weight of the compound of the formula LP2-1b.

[0620] The LC medium comprises one or more compounds of the formula XII, preferably of the formula XIIa or XIIb, very preferably of the formula XIIa, most preferably of the formula XIIa-1. The concentration of these compounds is preferably from 2% to 15% by weight.

[0621] The LC medium comprises from 1 to 15% by weight of the compound of the formula XIIb.

[0622] The LC medium comprises one or more compounds of the formula XIV, preferably of the formula XIVd, very preferably of the formula XIVd-1. The concentration of these compounds is preferably from 2% to 10% by weight.

[0623] - The LC medium comprises one or more compounds of the formula XVIb, preferably compounds of the formulae XVIb-1, XVIb-2 and / or XVIb-3. The concentration of these compounds is preferably from 2% to 15% by weight.

[0624] - The LC medium comprises one or more compounds of the formula XVIc, preferably compounds of the formula XVIc-1, XVIc-2 and / or XVIc-3. The concentration of these compounds is preferably 2% to 20% by weight.

[0625] The LC medium comprises one or more compounds selected from the group consisting of formulae XVIIa, XVIIb and XVIIc, very preferably formula XVIIa (wherein L is H) and formula XVIIb (wherein L is F). The total concentration of these compounds is preferably from 0.5% to 5% by weight.

[0626] - The LC medium comprises one or more compounds of the formula XX, preferably of the formula XXa. The concentration of these compounds is preferably from 2% to 10% by weight.

[0627] The LC medium comprises one or more compounds of the formula XXI, preferably compounds of the formula XXIa. The concentration of these compounds is preferably from 2% to 10% by weight.

[0628] - The LC medium comprises one or more compounds of the formula XXIII, preferably compounds of the formula XXIIIa. The concentration of these compounds is preferably from 0.5% to 5% by weight.

[0629] - The LC medium comprises one or more compounds of the formula XXIX, preferably compounds of the formula XXIXa. The concentration of these compounds is preferably from 2% to 10% by weight.

[0630] The LC medium comprises one or more compounds of the formula XXX. The concentration of these compounds is preferably from 2% to 10% by weight.

[0631] The LC medium comprises one or more compounds of the formula XXXI. The concentration of these compounds is preferably from 2% to 10% by weight.

[0632] The LC medium comprises one or more compounds of the formula S, preferably of the formula S-1-4-1. The concentration of these compounds is preferably from 1% to 25% by weight.

[0633] -LC medium comprises one or more compounds of formula I, preferably formula I-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 formula 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, XXXI and S or subformulae thereof.

[0634] -LC medium comprises one or more compounds of formula I, preferably formula I-1, LP1 and / or LP2, II and / or III; one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4 and Z5 or subformulae thereof; one or more compounds selected from the group consisting of formula XIVd or subformulae thereof; one or more compounds selected from the group consisting of formulae IVc, VIb, XXa, XXIIIa and XXIXa or subformulae thereof; and one or more compounds selected from the group consisting of formulae LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc, XXXI and S or subformulae thereof.

[0635] -LC medium comprises one or more compounds of formula I, preferably formula I-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, XXXI and S or subformulae thereof.

[0636] -LC medium comprises one or more compounds of formula I, preferably formula I-1, LP1 and / or LP2; one or more compounds selected from the group consisting of formulae Z1, Z2, Z3, Z4 and Z5 or subformulae thereof; one or more compounds of formula B, preferably selected from the group consisting of formulae B1, B2 and B3; one or more compounds of formula XIVd or subformulae thereof; one or more compounds selected from the group consisting of formulae II, III, IVc, VIb, XXa, XXIIIa and XXIXa or subformulae thereof; and one or more compounds selected from the group consisting of formulae LP1-1b, XVIb, XVIc, XVIIa, XVIIb, XVIIc, XXXI and S or subformulae thereof.

[0637] - In addition to the compounds of formula I, LP1 and / or LP2, the LC medium also comprises further compounds selected from the following group: compounds of formulae Z1, Z2, Z3, IV, LP1-1, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX, XXXI and XXIV or subformulae thereof.

[0638] - In addition to the compounds of formula I, LP1 and / or LP2, the LC medium also comprises further compounds selected from the following group: compounds of formulae Z1, Z2, Z3, IV, LP2-1, XIV, XVI, XVIIa, XVIIb, XVIIc, XXI, XXIII, XXIX, XXX, XXXI and XXIV or subformulae thereof.

[0639] The proportion of compounds of the formula I or its subformulae in the LC medium is from 1% to 30% by weight, very preferably from 2% to 25% by weight, most preferably from 2% to 20% by weight.

[0640] The proportion of compounds of the formulae Z1, Z2, Z3, Z4 and Z5 or subformulae thereof in the LC medium as a whole is from 10% to 65% by weight, very preferably from 20% to 60% by weight.

[0641] The proportion of the compound of the formula Y or a subformula thereof in the LC medium as a whole is from 0% to 15% by weight, very preferably from 2% to 10% by weight.

[0642] The proportion of the compound of the formula B or its subformulae in the LC medium as a whole is from 0% to 15% by weight, very preferably from 2% to 10% by weight.

[0643] The proportion of the compounds of the formulae II, III, IV-VIII, XVIII-XXIII and XXVII-XXX in the LC medium as a whole is 30% to 60% by weight.

[0644] The proportion of the compounds of the formulae XIV and XV in the LC medium as a whole is from 40% to 70% by weight.

[0645] The proportion of the compounds of the formulae XIV, XVIIa-c and XXXI-XXXIII in the LC medium as a whole is from 0.5% to 15% by weight.

[0646] The term "alkyl" or "alkyl*" in this application encompasses 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.

[0647] The term "alkenyl" or "alkenyl*" encompasses straight-chain and branched alkenyl groups having 2 to 6 carbon atoms, in particular straight-chain groups. Preferred alkenyl groups are C2-C7-1E-alkenyl, C4-C6-3E-alkenyl, in particular 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 having up to 5 carbon atoms, in particular CH2=CH, CH3CH=CH, are generally preferred.

[0648] The term "fluoroalkyl" preferably encompasses straight-chain groups with terminal fluorine, i.e. fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl and 7-fluoroheptyl. However, other positions of fluorine are not excluded.

[0649] The term "oxaalkyl" or "alkoxy" preferably encompasses groups of 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 in such a manner that the oxygen atoms are not directly connected to each other.

[0650] By appropriately selecting R in formula II and III 0 and X 0 The meaning of can modify the addressing time, threshold voltage, steepness of the transmission characteristic curve, etc. in a desired manner. For example, compared to alkyl and alkoxy groups, 1E-alkenyl, 3E-alkenyl, 2E-alkenyloxy, etc. generally lead to shorter addressing times, improved nematic tendencies, and a higher ratio between the elastic constants K3 (bend) and K1 (splay). Compared to alkyl and alkoxy groups, 4-alkenyl, 3-alkenyl, etc. generally give lower threshold voltages and lower K3 / K1 values. The LC media according to the present invention are particularly characterized by high Δε values ​​and thus have significantly faster response times compared to LC media of the prior art.

[0651] The optimum mixing ratio of the compounds of the above formulae depends essentially on the desired properties, the choice of the components of the above formulae and any additional components that may be present.

[0652] An appropriate mixing ratio within the range indicated above can be easily determined depending on the specific situation.

[0653] The total amount of compounds of the above formula in the LC media according to the invention is not critical. Thus, the LC media may contain one or more further components for optimizing various properties. However, the higher the total concentration of compounds of the above formula, the greater the effect observed on the desired improvement in the properties of the media.

[0654] 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 represents F, OCF3, OCHF2, OCH=CF2, OCF=CF2, or OCF2-CF2H. The favorable synergistic effect with the compounds of formula I, LP1 and / or LP2, II, and III results in particularly advantageous properties. In particular, LC media comprising compounds of formula I, LP1 and / or LP2, II, and III are characterized by their low threshold voltage.

[0655] The individual compounds of the formulae and subformulae mentioned above which can be used in the LC media according to the invention are known or can be prepared analogously to known compounds.

[0656] The present invention also relates to a process for preparing the LC medium described above and below, by mixing one or more compounds of the formula I with one or more compounds of the formula 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, XXXI and S.

[0657] The LC medium of the present invention may optionally comprise one or more polymerisable compounds. The polymerisable compounds are preferably selected from the group consisting of formula M

[0658] R a -B 1 -(Z b -B 2 ) m -R b M

[0659] wherein the substituents, which are identical or different on each occurrence and independently of one another, have the following meanings:

[0660] R a and R b represents 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 independently of one another be replaced by -C(R 0 )=C(R 00 )-、-C≡C-、-N(R 00 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, 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, R a and / or R b It can also represent a group spiro-linked to this saturated C atom,

[0661] The substituent R a and R b At least one of represents or contains a group P or P-Sp-,

[0662] P represents a polymerizable group,

[0663] Sp represents a spacer group or a single bond,

[0664] B1 and B 2 is 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,

[0665] Z b Represents -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,

[0666] R 0 and R 00 each independently of one another represents H or an alkyl group having 1 to 12 C atoms,

[0667] m represents 0, 1, 2, 3 or 4,

[0668] n1 means 1, 2, 3 or 4,

[0669] L represents P, 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 straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, where, in addition, one or more H atoms may be replaced by F, Cl, P or P-Sp-,

[0670] P and Sp have the meanings indicated above in formula M,

[0671] Y 1 represents halogen,

[0672] 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.

[0673] Particularly preferred compounds of formula M are those wherein B 1 and B 2 each independently of one another represents 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydro-phenanthrene-2,7-diyl, anthracene-2,7-diyl, fluorene-2,7-diyl, coumarin, flavonoids, wherein in addition one or more CH groups in these groups may be replaced by N, cyclohexane-1,4-diyl, wherein in addition one or more non-adjacent CH2 groups may be replaced by O and / or S, 1,4-cyclohexane-1,4-diyl, wherein in addition one or more non-adjacent CH2 groups may be replaced by O and / or S, hexenyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl or octahydro-4,7-methanoindane-2,5-diyl, all of which may be unsubstituted or monosubstituted or polysubstituted by L as defined in the above formula M.

[0674] Particularly preferred compounds of formula M are those wherein B 1 and B 2 Those which each independently of one another represent 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl or naphthalene-2,6-diyl.

[0675] Very preferred compounds of formula M are selected from the following formulae:

[0676]

[0677]

[0678]

[0679]

[0680]

[0681] where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another:

[0682] P 1 、P 2 、P 3 is a polymerizable group, preferably selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy groups,

[0683] Sp 1 、Sp 2 、Sp 3 is a single bond or a spacer group, and wherein the substituent P 1 -Sp 1 -、P 1 -Sp 2 - and P 3 -Sp 3 -One or more of them can represent R aa , the restriction being the presence of the substituent P 1 -Sp 1 -、P 2 -Sp 2 and P 3 -Sp 3 -At least one of them is different from R aa , preferably -(CH2) p1 -、-(CH2) p1 -O-, -(CH2) p1 -CO-O- or -(CH2) p1 -O-CO-O-, wherein p1 is an integer from 1 to 12,

[0684] R aa is H, F, Cl, CN or a straight-chain or branched alkyl radical having 1 to 25 C atoms, wherein one or more non-adjacent CH2 groups may each independently of one another be replaced by: -C(R 0 )=C(R 00 )-、-C≡C-、-N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, in such a way that the O atoms and / or S atoms are not directly bonded to each other, and in addition, one or more H atoms may be bonded via F, Cl, CN or P 1 -Sp 1 - instead, particularly preferably a straight-chain or branched, optionally monofluorinated or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy radical having 1 to 12 C atoms, where alkenyl and alkynyl radicals have at least two C atoms and branched radicals have at least three C atoms,

[0685] R 0 、R 00 is H or an alkyl group having 1 to 12 C atoms,

[0686] R y and R z is H, F, CH3 or CF3,

[0687] X 1 、X 2 、X 3 is -CO-O-, -O-CO- or a single bond,

[0688] Z M1 -O-, -CO-, -C(R y R z )- or -CF2CF2-,

[0689] Z M2 , Z M3 -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2) n -, where n is 2, 3, or 4,

[0690] L is F, Cl, CN or a linear or branched, optionally monofluorinated or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy radical having 1 to 12 C atoms,

[0691] L', L" are H, F or Cl,

[0692] r is 0, 1, 2, 3, or 4,

[0693] s is 0, 1, 2, or 3,

[0694] t is 0, 1, or 2,

[0695] x is 0 or 1.

[0696] Particularly preferred are compounds of formulae M2 and M13.

[0697] Further preferred are trireactive compounds of M15 to M31, especially M17, M18, M19, M22, M23, M24, M25, M30 and M31.

[0698] In the compounds of formulae M1 to M31, the group

[0699] Preferably

[0700]

[0701] wherein L has, identically or differently at each occurrence, one of the meanings given above or below for formula M and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, OCH3, COCH3 or OCF3, in particular F or CH3.

[0702] Preferred compounds of formula M1 to M31 are those wherein P 1 、P 2 and P 3 Those representing acrylate, methacrylate, oxetanyl or epoxy groups, very preferably acrylate or methacrylate groups.

[0703] Further preferred compounds of formula M1 to M31 are those wherein Sp 1 、Sp 2 and Sp 3 Those that are single bonds.

[0704] Further preferred compounds of formula M1 to M31 are those wherein Sp 1 、Sp 2 and Sp 3 One of them is a single bond, and Sp 1 、Sp 2 and Sp 3 The other one in is different from those of single bonds.

[0705] Further preferred compounds of the formulae M1 to M31 are those in which the group Sp which is different from a single bond is 1 、Sp 2 and Sp 3 Represents -(CH2) s1 -X"-, wherein s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5, and X" is a linker to the benzene ring and is -O-, -O-CO-, -CO-O-, -O-CO-O- or a single bond.

[0706] Particular preference is given to LC media comprising one, two or three polymerisable compounds of the formula M, preferably selected from the formulae M1 to M31.

[0707] It is further preferred that the LC media according to the present invention comprise one or more polymerisable compounds selected from Table H below.

[0708] 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%.

[0709] It has been observed that the addition of one or more polymerizable compounds, such as those selected from Formula M and Table H, to the LC medium results in advantageous properties, such as fast response time. Such LC media are particularly suitable for use in PSA displays, where they exhibit low image sticking, rapid and complete polymerization, rapid development 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, thereby enabling polymerization using such longer UV wavelengths, which is advantageous in the display manufacturing process.

[0710] The polymerizable group P is a group suitable for polymerization reactions, such as free radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-analogous reactions, such as addition or condensation onto the polymer backbone. Particular preference is given to groups suitable 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 (e.g., oxetane or epoxy groups).

[0711] Preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O-, CH2=CW 1 -CO-,

[0712]

[0713] CH2=CW 2 -(O) k3 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -、HS-CW 2 W 3 -、HW 2 N-、HO-CW 2 W 3 -NH-、CH2=CW 1-CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -、CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si-, 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 with one or more substituents L other than 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.

[0714] 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 -、CW 1 =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 4W 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 of 1 to 10.

[0715] Very particularly preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O-, especially 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-,

[0716] Further preferred polymerizable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, most preferably from acrylate and methacrylate.

[0717] If Sp is different from a single bond, it preferably has the formula Sp"-X", so that the corresponding substituent P-Sp- corresponds to the formula P-Sp"-X"-, in which

[0718] 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, wherein in addition one or more non-adjacent CH2 groups may each independently of one another be replaced 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(R0 )-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,

[0719] 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,

[0720] R 0 and R 00 each independently of one another represents H or an alkyl group having 1 to 20 C atoms, and

[0721] Y 2 and Y 3 Each independently represents H, F, Cl or CN.

[0722] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -、-NR 0 -CO-、-NR 0 -CO-NR 00 - or single key.

[0723] 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, R 0 and R 00 has the meaning indicated in the above formula M.

[0724] 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.

[0725] 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.

[0726] For the production of PSA displays, 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 liquid crystal display substrates, optionally while applying a voltage to the electrodes.

[0727] The structure of the PSA display according to the invention corresponds to the customary geometries of PSA displays, as described in the prior art cited above. Preference is given to geometries without protrusions, particularly those in which the color filter-side electrodes are unstructured and only the electrodes on the TFT side have grooves. For example, US 2006 / 0066793 A1 describes particularly suitable and preferred electrode structures for PS-VA displays.

[0728] The combination of the compounds of the above preferred embodiments with the above polymeric compounds leads to low threshold voltages, low rotational viscosities and very good low temperature stability in the LC media according to the invention, with simultaneously constant high bright spots and high VHR values.

[0729] The use of LC media containing polymerizable compounds allows the rapid establishment of particularly low pretilt angles in PSA displays. In particular, in PSA displays, the LC media exhibit significantly shortened response times, in particular grayscale response times, compared to media from the prior art.

[0730] Generally, preference is given to LC media having a nematic LC phase, preferably no chiral liquid crystal phase.

[0731] The present invention further 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 an electro-optical display of the type mentioned above, 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.

[0732] The invention further relates to an electro-optical display, such as 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 situated in the cell, wherein the nematic LC medium is an LC medium according to the invention as described above and below.

[0733] The LC media according to the invention enable a significant broadening of the usable parameter latitude. 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.

[0734] In particular, the combination of compounds of formula I with compounds of formula LP1 and / or LP2, and optionally with compounds selected from formulae II to XXXIII or subformulae thereof, results in LC media which exhibit 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 a low rotational viscosity and a low value for the ratio γ1 / K1. This enables energy-saving LC displays, especially FFS, HB-FFS, XB-FFS and IPS mode LC displays, with high brightness and transmittance and low response times.

[0735] The LC media according to the invention are suitable for mobile applications and TFT applications, such as mobile phones and PDAs. Furthermore, the LC media according to the invention are particularly suitable for FFS, HB-FFS, XB-FFS and IPS displays based on positive dielectric liquid crystals.

[0736] The LC media according to the invention enable excellent MLC displays with fast response times to be obtained while maintaining the nematic phase down to -20°C and preferably down to -30°C, particularly preferably down to -40°C, and a clearing point of ≥75°C, preferably ≥80°C, while simultaneously allowing a rotational viscosity γ1 of ≤120 mPa·s, particularly preferably ≤100 mPa·s to be obtained. The rotational viscosity is measured at 20°C.

[0737] The dielectric anisotropy Δε of the LC media according to the invention at 20° C. and 1 kHz is preferably ≧+1.5, very preferably between +3 and +18, most preferably between +5 and +15.

[0738] 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.

[0739] The rotational viscosity γ1 of the LC media according to the invention is preferably ≤120 mPa·s, more preferably ≤110 mPa·s and very preferably ≤90 mPa·s.

[0740] The ratio γ1 / K1 of the LC media according to the invention, where γ1 is the rotational viscosity and K1 is the elastic constant for the skew deformation, is preferably ≤7 mPa·s / pN, very preferably ≤6 mPa·s / pN, most preferably ≤5.5 mPa·s / pN.

[0741] The average elastic constant of the LC medium according to the invention is greater than K av Preferably it is at least 14.0 pN, very preferably at least 15.0 pN, and 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.

[0742] 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.

[0743] It goes without saying that, by suitable selection of the components of the LC media according to the invention, it is also possible to achieve higher clearing points (e.g. above 100° C.) at higher threshold voltages, or lower clearing points at lower threshold voltages, while maintaining other advantageous properties. It is likewise possible to obtain LC media with higher Δε and therefore lower threshold values, with a correspondingly only slightly increased viscosity. MLC displays according to the invention are preferably operated at the first Gooch and Tarry transmission minimum [C.H. Gooch and H.A. Tarry, Electron. Lett. 10, 2-4, 1974; C.H. Gooch and H.A. Tarry, Appl. Phys., Vol. 8, 1575-1584, 1975], where, in addition to particularly advantageous electro-optical properties (e.g., high characteristic line steepness and low angular dependence of the contrast (German Patent 30 22 818)), a lower dielectric anisotropy is sufficient at the same threshold voltage as in similar displays at the second minimum. This makes it possible to achieve significantly higher specific resistance values ​​at the first minimum using the LC media according to the invention than in the case of LC media comprising cyano compounds. By suitable selection of the individual components and their weight ratios, a person skilled in the art can set the necessary birefringence for a predetermined layer thickness in an MLC display using simple, conventional methods.

[0744] The 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)] has shown that compared with the inclusion of Cyano-phenylcyclohexane or Similar to LC media of the invention comprising esters of the formulae ST-1, ST-2, RV, IA and IB, the LC media according to the invention comprising compounds of the formulae ST-1, ST-2, RV, IA and IB exhibit a significantly smaller decrease in HR upon UV exposure.

[0745] The light and UV stability of the LC media according to the invention are significantly better, ie they exhibit a significantly smaller decrease in HR upon exposure to light, heat or UV.

[0746] The structure of the MLC display according to the present invention, consisting of a polarizer, an electrode base plate, and surface-treated electrodes, conforms to the conventional design of this type of display. The term "conventional design" is used in this context in a broad sense and also encompasses all derivatives and modifications of MLC displays, in particular including matrix display elements based on polysilicon TFTs or MIMs.

[0747] 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.

[0748] The LC media that can be used according to the invention are prepared in a conventional manner, for example, by mixing one or more compounds according to claim 1 with one or more compounds of the formulae II to XXXIIII or with other LC compounds and / or additives. Generally, the desired amount of the components used in smaller amounts is advantageously dissolved in the components constituting the main components at elevated temperature. It is also possible to mix solutions of the components in organic solvents (for example, in acetone, chloroform, or methanol) and, after thorough mixing, remove the solvent again, for example by distillation.

[0749] The LC medium may also contain other additives known to those skilled in the art and described in the literature, such as polymerization initiators, inhibitors, surfactants, light stabilizers, antioxidants (e.g. BHT, TEMPOL), microparticles, free radical scavengers, nanoparticles, etc. For example, 0 to 15% of polychromatic dyes or chiral dopants or initiators may be added, such as 651 or 907. Suitable stabilizers and dopants are described in Tables F and G below.

[0750] In a preferred embodiment, the LC medium comprises one or more stabilizers selected from Table G. Preferably, the proportion of stabilizers in the LC medium (for example those of the formulae ST and H as described above or listed in Table G) is from 10 to 2000 ppm, very preferably from 30 to 1000 ppm.

[0751] Furthermore, it is possible to add, for example, 0 to 15% by weight of polychromatic dyes, as well as nanoparticles, conductive salts (preferably ethyldimethyldodecyl ammonium 4-hexyloxybenzoate, tetrabutylammonium tetraphenylborate or complex salts of crown ethers (see, for example, Haller et al., Mol. Cryst. Liq. Cryst. 24 , 249-258 (1973))) for improving the electrical conductivity or adding substances for changing the dielectric anisotropy, viscosity and / or nematic alignment. Such substances are described, for example, in DE-A 22 09127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

[0752] For the present invention and in the following examples, the structures of the LC compounds are indicated by means of acronyms, which are converted into chemical formulae according to the following Tables A to C. All substituents C m H 2m+1 、Cn 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 alkylene group, having n, m and 1 C atoms, respectively, in each case. Preferably, n, m and 1 are independently 1, 2, 3, 4, 5, 6 or 7. Table A shows the code of the core ring element of the compound, Table B lists the bridging unit, and Table C lists the meaning of the symbol of the left and right 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 end group, and the second hyphen and the code of the right end group. Table D shows the schematic structure of the compound and their corresponding abbreviations.

[0753] Table A : Ring element

[0754]

[0755]

[0756]

[0757]

[0758] Table B : Bridge unit

[0759]

[0760] Table C :Terminal group

[0761]

[0762]

[0763] where n and m are each integers, and the three dots "..." are placeholders for other abbreviations from the table.

[0764] The following abbreviations are used:

[0765] (n, m, k and l are each independently an integer, preferably 1 to 12, preferably 1 to 6, k and l may also be 0, preferably 0 to 4, more preferably 0 or 2, 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".)

[0766] The preferred compositions of the LC media are shown in Tables D and E.

[0767] Table D

[0768]

[0769]

[0770]

[0771]

[0772] Table E

[0773] 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.

[0774]

[0775]

[0776]

[0777]

[0778]

[0779]

[0780]

[0781]

[0782]

[0783]

[0784]

[0785]

[0786] Particular preference is given to LC media which, in addition to the compounds of the formula I, LP1 and / or LP2, comprise at least one, two, three, four or more compounds from Table E.

[0787] Table F

[0788] Table F indicates possible dopants which are typically added to the LC media according to the invention. The LC media preferably comprise 0 to 10% by weight, in particular 0.01 to 5% by weight and particularly preferably 0.01 to 3% by weight of dopant.

[0789]

[0790] Table G

[0791] Stabilizers which may be additionally added to the LC media according to the invention, for example in amounts of 0% to 10% by weight, are described below.

[0792]

[0793]

[0794]

[0795]

[0796]

[0797] Table H

[0798] Table H shows illustrative reactive mesogenic compounds (RM) which can be used in the LC media according to the present invention.

[0799]

[0800]

[0801]

[0802]

[0803]

[0804]

[0805]

[0806]

[0807]

[0808]

[0809]

[0810]

[0811]

[0812]

[0813]

[0814]

[0815]

[0816]

[0817]

[0818]

[0819]

[0820] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from the group consisting of polymerizable compounds of formulae RM-1 to RM-182. Among them, 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-183 are particularly preferred.

[0821] Table I

[0822] Table 1 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:

[0823]

[0824]

[0825]

[0826]

[0827]

[0828]

[0829]

[0830]

[0831]

[0832]

[0833]

[0834] 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-48, preferably from the formulae SA-14 to SA-48, very preferably from the formulae SA-20 to SA-34 and SA-44 in combination with one or more RMs.

[0835] The following examples are intended to illustrate the present invention, not to limit the present invention.

[0836] In this context, percentage data refer to weight percentages. All temperatures are given in degrees Celsius. mp = melting point, cl.p. = clearing point. Furthermore, C = crystalline, N = nematic, S = smectic, and I = isotropic. The data between these symbols represent transition temperatures. Furthermore, the following symbols are used:

[0837] V0 represents the Freedericks threshold voltage at 20°C, capacitance [V],

[0838] V 10 represents the voltage [V] for 10% transmittance,

[0839] n e represents the extraordinary refractive index measured at 20°C and 589 nm,

[0840] n0 is the ordinary refractive index measured at 20°C and 589 nm,

[0841] Δn represents the optical anisotropy measured at 20 °C and 589 nm,

[0842] ε ⊥ represents the dielectric constant perpendicular to the longitudinal axis of the molecule at 20°C and 1 kHz,

[0843] ε || represents the dielectric constant (or permittivity) parallel to the longitudinal axis of the molecule at 20°C and 1 kHz,

[0844] Δε represents the dielectric anisotropy at 20°C and 1 kHz,

[0845] cl.p. or T(N,I) represents the clearing point [℃],

[0846] υ represents the flow viscosity measured at 20°C [mm 2 ·s -1 ],

[0847] γ1 represents the rotational viscosity measured at 20°C [mPa·s],

[0848] K1 represents the elastic constant at 20°C, the “bending” deformation [pN],

[0849] K2 represents the elastic constant at 20°C, "torsion" deformation [pN],

[0850] K3 represents the elastic constant at 20°C, the “bending” deformation [pN], and

[0851] VHR stands for voltage holding ratio.

[0852] Unless expressly indicated otherwise, all physical properties are measured according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, November 1997, Merck KGaA, Germany, and apply to a temperature of 20°C. Example

[0853] Example M1 (comparative)

[0854] The nematic LC medium was prepared as follows:

[0855]

[0856]

[0857] The liquid crystal mixture had a Kav of 13.50 pN and a γ1 / K1 of 3.29 mPa s / PN.

[0858] Mixture Example S1 (Stabilized with a compound of formula ST-1-3)

[0859] The nematic LC mixture according to the present invention was formulated as follows:

[0860] Mixture M1 99.95wt.-% Compound of formula ST-1-3 500ppm

[0861] Compared to the unstabilized mixture M1, 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 M1.

[0862]

[0863] Example M2 (present invention)

[0864] The nematic LC medium was prepared as follows:

[0865]

[0866]

[0867] The LC mixture has a K of 14.23 pN av and γ1 / K1 of 3.28 mPa s / pN. Thus, the LC mixture of Example 2 (inventive) has a significantly higher average elastic constant Kav than the LC mixture of Example 1 (comparative), while the response time parameter γ1 / K1 of both mixtures is essentially the same.

[0868] Mixture Example S2 (Stabilized with Compound of Formula H-3-1)

[0869] The nematic LC mixture according to the present invention was formulated as follows:

[0870] Mixture M2 99.9wt.-% Compound of formula H-3-1 1000ppm

[0871] Compared to the unstabilized mixture M2, the addition of 1000 ppm of the compound of formula H-3-1 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of the mixture M2.

[0872]

[0873] Example M3 (present invention)

[0874] The nematic LC medium was prepared as follows:

[0875]

[0876] The LC mixture has a K of 14.87 pN av and γ1 / K1 of 3.19 mPa s / pN.

[0877] Mixture Example S3 (Stabilized with a Compound of Formula ST-2-3)

[0878] The nematic LC mixture according to the present invention was formulated as follows:

[0879] Mixture M3 99.95wt.-% Compound of formula ST-2-3 500ppm

[0880] Compared to the unstabilized mixture M3, the addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M3.

[0881]

[0882] Example M4 (present invention)

[0883] The nematic LC medium was prepared as follows:

[0884]

[0885] The LC mixture has a K of 14.85 pN av and γ1 / K1 of 3.09 mPa s / pN.

[0886] Mixture Example S4 (Stabilized with Compound of Formula H-3-3)

[0887] The nematic LC mixture according to the present invention was formulated as follows:

[0888] Mixture M4 99.9wt.-% Compound of formula H-3-3 1 000ppm

[0889] Compared to the unstabilized mixture M4, the addition of 1000 ppm of the compound of formula H-3-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M4.

[0890]

[0891] Example M5 (present invention)

[0892] The nematic LC medium was prepared as follows:

[0893]

[0894]

[0895] The LC mixture has a K of 14.77 pN av and γ1 / K1 of 3.33 mPa s / pN.

[0896] Mixture Example S5 (stabilized with compound of formula H-3-5)

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

[0898] Mixture M5 99.995wt.-% Compound of formula H-3-5 50ppm

[0899] Compared to the unstabilized mixture M5, the addition of 50 ppm of the compound of formula H-3-5 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M5.

[0900] Example M6 (present invention)

[0901] The nematic LC medium was prepared as follows:

[0902]

[0903] The LC mixture has a K of 14.75 pN av and γ1 / K1 of 3.35 mPa s / pN. Mixture Example S6 (Stabilized with Compound of Formula ST-1-3)

[0904] The nematic LC mixture according to the present invention was formulated as follows:

[0905] Mixture M6 99.95wt.-% Compound of formula ST-1-3 500ppm

[0906] Compared to the unstabilized mixture M6, 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 M6.

[0907] Example M7 (present invention)

[0908] The nematic LC medium was prepared as follows:

[0909]

[0910] The LC mixture has a K of 16.23 pN av and γ1 / K1 of 3.17 mPa s / pN

[0911] Mixture Example S7 (Stabilized with a Compound of Formula ST-1-3)

[0912] The nematic LC mixture according to the present invention was formulated as follows:

[0913] Mixture M7 99.97wt.-% Compound of formula ST-1-3 300ppm

[0914] Compared to the unstabilized mixture M7, the addition of 300 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.

[0915] Example M8 (present invention)

[0916] The nematic LC medium was prepared as follows:

[0917]

[0918]

[0919] The LC mixture has a K of 15.73 pN av and γ1 / K1 of 3.20 mPa s / pN.

[0920] Mixture Example S8 (Stabilized with a Compound of Formula ST-2-3)

[0921] The nematic LC mixture according to the present invention was formulated as follows:

[0922] Mixture M8 99.96wt.-% Compound of formula ST-2-3 400ppm

[0923] Compared to the unstabilized mixture M8, 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 M8.

[0924] Example M9 (present invention)

[0925] The nematic LC medium was prepared as follows:

[0926]

[0927]

[0928] The LC mixture has a K of 18.75 pN av and γ1 / K1 of 3.08 mPa s / pN.

[0929] Mixture Example S9 (Stabilized with Compound of Formula H-3-1)

[0930] The nematic LC mixture according to the present invention was formulated as follows:

[0931] Mixture M9 99.9wt.-% Compound of formula H-3-1 1 000ppm

[0932] Compared to the unstabilized mixture M9, the addition of 1000 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 M9.

[0933] Example M10 (present invention)

[0934] The nematic LC medium was prepared as follows:

[0935]

[0936]

[0937] The LC mixture has a K of 16.22 pN av and γ1 / K1 of 5.57 mPa s / pN.

[0938] Mixture Example S10 (Stabilized with Compound of Formula H-3-1)

[0939] The nematic LC mixture according to the present invention was formulated as follows:

[0940] Mixture M10 99.9wt.-% Compound of formula H-3-1 1 000ppm

[0941] Compared to the unstabilized mixture M10, the addition of 1000 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 M10.

[0942] Example M11 (present invention)

[0943] The nematic LC medium was prepared as follows:

[0944]

[0945] The LC mixture has a K of 16.00 pN av and γ1 / K1 of 5.49 mPa s / pN.

[0946] Mixture Example S11 (Stabilized with Compound of Formula H-3-1)

[0947] The nematic LC mixture according to the present invention was formulated as follows:

[0948] Mixture M11 99.9wt.-% Compound of formula H-3-1 1 000ppm

[0949] Compared to the unstabilized mixture M11, the addition of 1000 ppm of the compound of formula H-3-1 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M11.

[0950] Example M12 (present invention)

[0951] The nematic LC medium was prepared as follows:

[0952]

[0953]

[0954] The LC mixture has a K of 16.52 pN av and γ1 / K1 of 5.72 mPa s / pN.

[0955] Mixture Example S12 (Stabilized with Compound of Formula ST-1-3)

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

[0957] Mixture M12 99.95wt.-% Compound of formula ST-1-3 500ppm

[0958] Compared to the unstabilized mixture M12, the addition of 500 ppm of the compound of formula ST-1-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M12.

[0959] Example M13 (present invention)

[0960] The nematic LC medium was prepared as follows:

[0961]

[0962]

[0963] The LC mixture has a K of 15.83 pN av and γ1 / K1 of 5.39 mPa s / pN.

[0964] Mixture Example S13 (Stabilized with Compound of Formula ST-1-3)

[0965] The nematic LC mixture according to the present invention was formulated as follows:

[0966] Mixture M13 99.96wt.-% Compound of formula ST-1-3 400ppm

[0967] Compared to the unstabilized mixture M13, the addition of 400 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 M13. Example M14 (present invention)

[0968] The nematic LC medium was prepared as follows:

[0969]

[0970] The LC mixture has a K of 15.08 pNav and γ1 / K1 of 3.08 mPa s / pN. Mixture Example S14 (Stabilized with Compound of Formula ST-2-3)

[0971] The nematic LC mixture according to the present invention was formulated as follows:

[0972]

[0973]

[0974] The addition of 500 ppm of the compound of formula ST-2-3 significantly improved the VHR100 after UV exposure compared to the unstabilized mixture M14, without affecting the remaining physical properties of the mixture M14.

[0975] Example M15 (present invention)

[0976] The nematic LC medium was prepared as follows:

[0977]

[0978] The LC mixture has a K of 15.20 pN av and γ1 / K1 of 3.25 mPa s / pN.

[0979] Mixture Example S15 (Stabilized with Compound of Formula ST-2-3)

[0980] The nematic LC mixture according to the present invention was formulated as follows:

[0981] Mixture M15 99.97wt.-% Compound of formula ST-2-3 300ppm

[0982] Compared to the unstabilized mixture M15, the addition of 300 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 M15.

[0983] Example M16 (present invention)

[0984] The nematic LC medium was prepared as follows:

[0985]

[0986]

[0987] The LC mixture has a K of 14.57 pN av and γ1 / K1 of 3.26 mPa s / pN.

[0988] Mixture Example S16 (Stabilized with Compound of Formula ST-2-3)

[0989] The nematic LC mixture according to the present invention was formulated as follows:

[0990] Mixture M16 99.97wt.-% Compound of formula ST-2-3 300ppm

[0991] The addition of 300 ppm of the compound of formula ST-2-3 significantly improved the VHR100 after UV exposure compared to the unstabilized mixture M16, without affecting the remaining physical properties of the mixture M16.

[0992] Example M17 (present invention)

[0993] The nematic LC medium was prepared as follows:

[0994]

[0995]

[0996] The LC mixture has a K of 15.85 pN av and γ1 / K1 of 3.23 mPa s / pN.

[0997] Mixture Example S17 (Stabilized with Compound of Formula ST-2-3)

[0998] The nematic LC mixture according to the present invention was formulated as follows:

[0999] Mixture M17 99.96wt.-% Compound of formula ST-2-3 400ppm

[1000] Compared to the unstabilized mixture M17, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M17.

[1001] Example M18 (present invention)

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

[1003]

[1004]

[1005] The LC mixture has a K of 17.65 pN av and γ1 / K1 of 3.20 mPa s / pN.

[1006] Mixture Example S18 (Stabilized with Compound of Formula ST-2-3)

[1007] The nematic LC mixture according to the present invention was formulated as follows:

[1008] Mixture M18 99.96wt.-% Compound of formula ST-2-3 400ppm

[1009] Compared to the unstabilized mixture M18, 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 M18.

[1010] Example M19 (present invention)

[1011] The nematic LC medium was prepared as follows:

[1012]

[1013]

[1014] Mixture Example S19 (Stabilized with Compound of Formula ST-2-3)

[1015] The nematic LC mixture according to the present invention was formulated as follows:

[1016] Mixture M19 99.97wt.-% Compound of formula ST-2-3 300ppm

[1017] Compared to the unstabilized mixture M19, the addition of 300 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 M19.

[1018] Example M20 (present invention)

[1019] The nematic LC medium was prepared as follows:

[1020]

[1021]

[1022] Mixture Example S20 (stabilized with compound of formula ST-2-3) A nematic LC mixture according to the present invention was prepared as follows:

[1023]

[1024]

[1025] Compared to the unstabilized mixture M20, the addition of 300 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M20.

[1026] Example M21 (present invention)

[1027] The nematic LC medium was prepared as follows:

[1028]

[1029]

[1030] The LC mixture has a K of 13.52 pN av and γ1 / K1 of 3.63 mPa s / pN.

[1031] Mixture Example S21 (Stabilized with Compound of Formula ST-2-3)

[1032] The nematic LC mixture according to the present invention was formulated as follows:

[1033] Mixture M21 99.96wt.-% Compound of formula ST-2-3 400ppm

[1034] 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 other physical properties of mixture M20.

[1035] Example M22 (present invention)

[1036] The nematic LC medium was prepared as follows:

[1037]

[1038]

[1039]

[1040] The LC mixture has a K of 13.80 pN av and γ1 / K1 of 3.51 mPa s / pN.

[1041] Mixture Example S22 (Stabilized with Compound of Formula ST-2-3)

[1042] The nematic LC mixture according to the present invention was formulated as follows:

[1043] Mixture M22 99.96wt.-% Compound of formula ST-2-3 400ppm

[1044] Compared to the unstabilized mixture M22, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M22.

[1045] Example M23 (present invention)

[1046] The nematic LC medium was prepared as follows:

[1047]

[1048]

[1049] The LC mixture has a K of 13.85 pN av and a γ1 / K1 of 3.43 mPa s / pN. The nematic LC mixture according to the present invention was formulated as follows:

[1050] Mixture Example S23 (Stabilized with Compound of Formula ST-2-3)

[1051] Mixture M22 99.96wt.-% Compound of formula ST-2-3 400ppm

[1052] Compared to the unstabilized mixture M23, the addition of 400 ppm of the compound of formula ST-2-3 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M23.

[1053] Example M24 (present invention)

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

[1055]

[1056]

[1057] Mixture Example S24 (Stabilized with Compound of Formula ST-2-3)

[1058] The nematic LC mixture according to the present invention was formulated as follows:

[1059] Mixture M24 99.96wt.-% Compound of formula ST-2-3 400ppm

[1060] Compared to the unstabilized mixture M24, 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 M24.

[1061] Example M25 (present invention)

[1062] The nematic LC medium was prepared as follows:

[1063]

[1064]

[1065] Mixture Example S25 (Stabilized with Compound of Formula ST-1-8)

[1066] The nematic LC mixture according to the present invention was formulated as follows:

[1067] Mixture M25 99.97wt.-% Formula ST-1-8 compound 300ppm

[1068] Compared to the unstabilized mixture M25, the addition of 300 ppm of the compound of formula ST-1-8 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M25.

[1069]

[1070] Example M26 (present invention)

[1071] The nematic LC medium was prepared as follows:

[1072]

[1073]

[1074] Mixture Example S26 (Stabilized with Compound of Formula ST-2-8)

[1075] The nematic LC mixture according to the present invention was formulated as follows:

[1076] Mixture M26 99.97wt.-% Compound of formula ST-2-8 300ppm

[1077]

[1078] Compared to the unstabilized mixture M26, the addition of 300 ppm of the compound of formula ST-2-8 significantly improved the VHR after UV exposure. 100 , without affecting the remaining physical properties of mixture M26.

[1079] Example M27 (present invention)

[1080] The nematic LC medium was prepared as follows:

[1081]

[1082] Mixture Example S27 (Stabilized with Compound of Formula ST-4-1)

[1083] The nematic LC mixture according to the present invention was formulated as follows:

[1084]

[1085]

[1086]

[1087] Compared to the unstabilized mixture M27, the addition of 600 ppm of the compound of formula ST-4-1 significantly improved the VHR after UV exposure.100 , without affecting the remaining physical properties of mixture M27.

[1088] Example M28 (present invention)

[1089] The nematic LC medium was prepared as follows:

[1090]

[1091]

[1092] Mixture Example S28 (Stabilized with Compound of Formula ST-4-2)

[1093] The nematic LC mixture according to the present invention was formulated as follows:

[1094] Mixture M28 99.94wt.-% Compound of formula ST-4-2 600ppm

[1095]

[1096] Compared to the unstabilized mixture M28, the addition of 600 ppm of the compound of formula ST-4-2 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M28.

[1097] Example M29 (present invention)

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

[1099]

[1100]

[1101] Mixture Example S29 (Stabilized with Compound of Formula ST-4-2)

[1102] The nematic LC mixture according to the present invention was formulated as follows:

[1103] Mixture M29 99.95wt.-% Compound of formula ST-4-2 500ppm

[1104] Compared to the unstabilized mixture M29, the addition of 500 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 M29.

[1105] Example M30 (present invention)

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

[1107]

[1108] Mixture Example S30 (Stabilized with Compound of Formula ST-4-1)

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

[1110] Mixture M30 99.95wt.-% Compound of formula ST-4-1 500ppm

[1111] Compared to the unstabilized mixture M30, 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 mixture M30.

[1112] Example M31 (present invention)

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

[1114]

[1115] Mixture Example S31 (Stabilized with Compound of Formula H-3-2)

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

[1117]

[1118]

[1119] Compared to the unstabilized mixture M31, the addition of 100 ppm of the compound of formula H-3-2 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M31.

[1120]

[1121] Example M32 (present invention)

[1122] The nematic LC medium was prepared as follows:

[1123]

[1124]

[1125] Mixture Example S32 (Stabilized with Compound of Formula H-3-4)

[1126] The nematic LC mixture according to the present invention was formulated as follows:

[1127] Mixture M32 99.99wt.-% Compound of formula H-3-4 100ppm

[1128] Compared to the unstabilized mixture M32, the addition of 100 ppm of the compound of formula H-3-4 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M32.

[1129]

[1130] Example M33 (present invention)

[1131] The nematic LC medium was prepared as follows:

[1132]

[1133]

[1134] Mixture Example S33 (Stabilized with Compound of Formula H-3-6)

[1135] The nematic LC mixture according to the present invention was formulated as follows:

[1136] Mixture M33 99.995wt.-% Compound of formula H-3-6 50ppm

[1137] Compared to the unstabilized mixture M33, the addition of 50 ppm of the compound of formula H-3-6 significantly improved the VHR after UV exposure. 100 , without affecting the other physical properties of mixture M33.

[1138]

[1139] Example M34 (Invention) A nematic LC medium was prepared as follows:

[1140]

[1141]

[1142] Mixture Example S34 (Stabilized with Compound of Formula H-3-7)

[1143] The nematic LC mixture according to the present invention was formulated as follows:

[1144] Mixture M34 99.98wt.-% Compound of formula H-3-7 200ppm

[1145] The addition of 200 ppm of the compound of formula H-3-7 significantly improved the VHR100 after UV exposure compared to the unstabilized mixture M34, without affecting the remaining physical properties of the mixture M34.

[1146]

[1147] Example M35 (present invention)

[1148] The nematic LC medium was prepared as follows:

[1149]

[1150]

[1151] Mixture Example S35 (Stabilized with Compound of Formula H-3-9)

[1152] The nematic LC mixture according to the present invention was formulated as follows:

[1153] Mixture M35 99.995wt.-% Compound of formula H-3-9 50ppm

[1154] Compared to the unstabilized mixture M35, 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 M35.

[1155]

[1156] Example M36 (Invention) A nematic LC medium was prepared as follows:

[1157]

[1158]

[1159] Mixture Example S36 (Stabilized with Compound of Formula H-3-10)

[1160] The nematic LC mixture according to the present invention was formulated as follows:

[1161] Mixture M36 99.995wt.-% Compound of formula H-3-10 50ppm

[1162] Compared to the unstabilized mixture M36, 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 M36.

[1163]

Claims

1. A liquid crystal medium, characterized in that The liquid crystal medium comprises One or more compounds of formula I where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another: R 11 and R 12 Each independently of one another represents an H atom, an alkyl or alkoxy group having 1 to 12 C atoms, or an alkenyl or alkenyloxy group having 2 to 12 C atoms, wherein one or more 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom, or a cycloalkyl or cycloalkoxy group having 3 to 12 C atoms, in which one or more H atoms may be replaced by a halogen atom, preferably a cyclopentyl or cyclopentyloxy group, Z 1 represents a single bond, -CH2CH2- or -COO-; and One or more compounds selected from the group consisting of the following formulae LP1 and LP2: where the individual substituents have the following meanings on each occurrence, identically or differently and independently of one another: R 0 is an alkyl or alkoxy group having 1 to 12 C atoms, or an alkenyl group having 2 to 12 C atoms, wherein one or more CH2 groups are optionally substituted by the following groups: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom, R 2 is an alkyl or alkoxy group having 1 to 6 C atoms, wherein one or more CH2 groups are optionally substituted by the following groups: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom, X 2 is an F atom 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 an F atom, Y 0 is H or CH3, L 1 and L 2 are independently H, F or Cl, Y 0 is H or CH3, m and n independently represent 0, 1 or 2.

2. The liquid-crystalline medium according to claim 1 , wherein the one or more compounds of formula I are described by formula I-1: in R 11 and R 12 Each independently of one another represents an H atom, 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 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 bonded to one another and in which one or more H atoms may be replaced by a halogen atom, or a cycloalkyl or cycloalkoxy group having 3 to 6 C atoms, in which one or more H atoms may be replaced by a halogen atom.

3. Liquid-crystalline medium according to claim 1 or 2, characterized in that The one or more compounds of formula LP1 and LP2 are described by formula LP1-1 and LP2-1: in R 0 is an alkyl or alkoxy group having 1 to 6 C atoms, or an alkenyl group having 2 to 12 C atoms, wherein one or more CH2 groups are optionally substituted by the following groups: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom, R 2 is an alkyl or alkoxy group having 1 to 6 C atoms, wherein one or more CH2 groups are optionally substituted by the following groups: -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in such a manner that the O atoms are not directly bonded to one another and wherein one or more H atoms may be replaced by a halogen atom; X 2 is an F atom, or an alkyl or alkoxy group having 1 to 3 C atoms, or an alkenyl or alkenyloxy group having 2 or 3 C atoms, wherein one or more H atoms are replaced by an F atom, and Y 0 is H or CH3.

4. Liquid-crystalline medium according to one or more of claims 1 to 3, characterized in that The liquid-crystalline medium comprises one or more compounds selected from the following formulae II and III: where the individual substituents, independently of one another and identically or differently on each occurrence, have the following meanings: for for R 0 According to claim 1, 11 One of the meanings given, L 1-6 are independently H or F, X 0 are independently F, Cl, halogenated alkyl, halogenated alkenyl, halogenated alkoxy or halogenated alkenyloxy with up to 6 C atoms, and Y 0 is H or CH3.

5. Liquid-crystalline medium according to claim 4, wherein 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. Liquid-crystalline medium according to claim 4, wherein 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. Liquid-crystalline medium according to one or more of claims 1 to 6, characterized in that The liquid crystal medium comprises one or more compounds selected from the following formulae Z1 to Z7: "alkyl" and "alkyl*" represent C 1-6 alkyl, and "alkenyl" and "alkenyl*" indicate C 2-6 Alkenyl.

8. Liquid-crystalline medium according to one or more of claims 1 to 7, characterized in that The liquid-crystalline medium comprises one or more compounds selected from the group consisting of: where R 1 and R 2 each independently of one another represents n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having up to 6 C atoms, "alkenyl" means C 2-6 alkenyl, and L 1 has the meaning indicated in claim 1.

9. Liquid-crystalline medium according to one or more of claims 1 to 8, characterized in that The liquid-crystalline 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 indicated in claim 4, L 3 and L 4 Independently of each other, they have 1 one of the meanings given, and 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 s represents 0 or 1.

10. Liquid-crystalline medium according to one or more of claims 1 to 9, characterized in that The liquid-crystalline medium comprises one or more compounds selected from the group consisting of: where R 0 , L 1-4 、Y 0 and X 0 Each independently of one another has one of the meanings indicated in claim 4 .

11. Liquid-crystalline medium according to one or more of claims 1 to 10, characterized in that The liquid-crystalline medium comprises one or more compounds selected from the group consisting of: where R 1 and X 0 With the R in claim 4 0 and X 0 The meaning indicated.

12. Liquid-crystalline medium according to one or more of claims 1 to 11, characterized in that The liquid-crystalline medium comprises one or more compounds of the formula I, LP1 and LP2 and one or more compounds selected from the group consisting of the following formulae: Z1, Z2, Z3, Z4, Z5, II, III, IV, VI, XIV, XX, XXIII, XXIX, XVI, XVIIa, XVIIb and XVIIc.

13. Liquid-crystalline medium according to one or more of claims 1 to 12, characterized in that The liquid-crystalline medium further comprises one or more polymerizable compounds.

14. Process for producing a liquid-crystalline medium according to one or more of claims 1 to 13, characterized in that One or more compounds of formula I and one or more compounds of formula LP1 and / or LP2 are mixed with one or more mesogenic compounds and optionally one or more polymerizable compounds and / or one or more additives.

15. Use of a liquid-crystalline medium according to one or more of claims 1 to 13 for electro-optical purposes.

16. Electro-optical liquid-crystal display comprising a liquid-crystal medium according to one or more of claims 1 to 13.

17. An electro-optical liquid crystal display according to claim 15, characterized in that The electro-optical liquid crystal display is 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.

18. An electro-optical liquid crystal display according to claim 16, characterized in that The electro-optical liquid crystal display is an FFS, HB-FFS, XB-FFS, PS-HB-FFS, PS-XB-FFS, IPS or PS-IPS display.

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