Liquid-crystal medium

Abstract

To provide a liquid-crystal medium.SOLUTION: The present invention relates to a liquid-crystal (LC) medium or LC material based on a mixture of polar compounds, its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the vertically aligned mode and / or the fringe-field switching mode, an LC display of the vertically aligned mode and / or the fringe-field switching mode comprising the LC medium, especially an energy-saving LC display, and a process of manufacturing the LC display.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal (LC) medium or LC material based on a mixture of polar compounds and to its use for optical, electro-optical and electronic purposes, in particular in LC displays, in particular in vertically aligned mode and / or fringe field switched mode LC displays, and to vertically aligned mode and / or fringe field switched mode LC displays, in particular energy-saving LC displays, comprising the LC medium, as well as to a method for preparing the LC medium and to a method for producing an LC display. [Background technology]

[0002] So-called VA ("vertically aligned") displays are known, which have wider viewing angles and faster response times. The LC cell of a VA display comprises a layer of LC medium between two transparent electrodes, where the LC medium usually has a negative value of dielectric anisotropy (Δε). In the switched-off state, the molecules of the LC layer are aligned perpendicular to the electrode surfaces (homeotropic) or have a tilted homeotropic alignment. When a voltage is applied to the two electrodes, a reorientation of the LC molecules occurs parallel to the electrode surfaces.

[0003] Furthermore, UV 2 VA displays using alignment layers prepared by photoalignment, known as A-mode, have been disclosed (see, for example, Q. Tang et al., SID Symposium Digest of Technical Papers, 2018, pp. 414-417 (Non-Patent Document 1)). These displays utilize alignment layers prepared from crosslinkable, photoalignable monomers or prepolymers, such as cinnamic acid chromophores, and are obliquely irradiated with linearly polarized UV light. This results in the formation of a crosslinked alignment layer, which induces uniaxial alignment with a pretilt angle in the LC molecules near its surface. By varying the irradiation direction, a multidomain structure with different pretilt directions can be obtained.

[0004] Thanks to a special polymer stabilization process, PS-VA ("polymer stabilized-vertically aligned") technology ensures that the liquid crystals are not perfectly vertical in their black state, but have a slight tilt. This is called "tilt" and ensures that the direction in which the liquid crystal molecules switch is locally defined.

[0005] Furthermore, so-called FFS ("fringe-field switching") displays have been reported (see, in particular, SH Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, p. 1028 (Non-Patent Document 2)), which have two electrodes on the same substrate, one of which is structured in a comb shape and the other unstructured. This generates a strong so-called "fringe field", i.e., a strong electric field near the electrode edges, which generates an electric field across the cell with both a strong vertical component and a strong horizontal component. FFS displays have a low viewing angle dependence of their contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy and an alignment layer, usually a polyimide alignment layer, which provides a planar alignment for the molecules of the LC medium.

[0006] FFS displays can be operated as active matrix displays or passive matrix displays. In the case of active matrix displays, individual pixels are typically addressed by integrated non-linear active elements such as transistors (e.g., thin film transistors ("TFTs")), while in the case of passive matrix displays, individual pixels are typically addressed by multiplexing methods known from the prior art.

[0007] Furthermore, FFS displays have been disclosed that have electrode designs and layer thicknesses similar to those of FFS displays, but that have LC medium layers with negative dielectric anisotropy rather than those with positive dielectric anisotropy (see, for example, S.H. Lee et al., Appl. Phys. Lett., Vol. 73 (No. 20), 1998, pp. 2882-2883 (Non-Patent Document 3) and S.H. Lee et al., Liquid Crystals, Vol. 39 (No. 9), 2012, pp. 1141-1148 (Non-Patent Document 4)). LC media with negative dielectric anisotropy exhibit more favorable director alignment with smaller tilt and higher twist alignment than LC media with positive dielectric anisotropy, resulting in higher transmittance for these displays.

[0008] UB-FFS ("ultra-brightness fringe field switching") technology or UBplus technology is based on FFS technology, which uses a dielectrically negative element to increase the overall transmittance of the panel. UB-FFS is primarily used in smaller devices, while UBplus is primarily used in larger displays. Specifically, specially oriented liquid crystals allow the backlight illuminating a UB-FFS display to have a brighter transmittance, and the optimized use of light reduces the energy demand of a UB-FFS display by at least one-third, while improving image quality. This results in a longer run time and / or a brighter display.

[0009] Also known are so-called IPS ("in-plane switching") devices, which comprise an LC layer with planar alignment between two substrates, but with two electrodes located on only one of the two substrates, preferably with an interdigitated comb-like structure. When a voltage is applied to the electrodes, an electric field is generated between them with a significant component parallel to the LC layer. This causes a reorientation of the LC molecules in the plane of the layer.

[0010] However, the use of LC media with negative dielectric anisotropy in VA or FFS displays also has some drawbacks: for example, they have significantly lower reliability compared to LC media with positive dielectric anisotropy.

[0011] As used herein, the term "reliability" refers to the performance quality of a display when subjected to various stresses such as illumination load, temperature, humidity, and voltage, which result in display defects such as image sticking (area and line image sticking), mottling, and smearing, and are known to those skilled in the art of LC displays. A standard parameter used to classify reliability is usually the voltage holding ratio (VHR), which is a measure of maintaining a constant voltage in a test display. The higher the VHR value, the better the reliability of the medium.

[0012] The reduced reliability of LC media with negative dielectric anisotropy in VA or FFS displays can be explained by the interaction of the LC molecules with the polyimide of the alignment layer, resulting in the extraction of ions from the polyimide alignment layer, and LC molecules with negative dielectric anisotropy extract such ions more effectively.

[0013] This results in new requirements for the LC media to be used in VA or FFS displays. In particular, the LC media must exhibit high reliability and high VHR values after UV exposure. Further requirements are high resistivity, a large operating temperature range, short response times even at low temperatures, low threshold voltages, a large number of grey levels (gray-out), high contrast and a wide viewing angle, as well as reduced image sticking.

[0014] Thus, in displays known from the prior art, one often observes the undesirable effect so-called "image sticking" or "image burning", whereby images created in LC displays by temporary addressing of individual pixels remain visible and remain even after the electric field in these pixels has been switched off or other pixels have been addressed.

[0015] On the other hand, the use of LC media with low VHR can cause this "image sticking." The UV component of daylight or backlight can cause undesired decomposition reactions of the LC molecules in the mixture, thereby initiating the production of ionic or free radical impurities. These can accumulate, particularly in the electrodes or alignment layers, where they can reduce the effective applied voltage.

[0016] Another problem encountered in the prior art is that LC media for use in displays, including but not limited to FFS displays, often exhibit high viscosity and, as a result, high switching times. To reduce the viscosity and switching time of LC media, the prior art has suggested adding LC compounds having alkenyl groups. However, LC media containing alkenyl compounds often exhibit reduced reliability and stability, and VHR has been observed to decrease, especially after exposure to UV radiation, but also to visible light from the backlight of displays that do not normally emit UV light. [Prior art documents] [Non-patent literature]

[0017] [Non-Patent Document 1] Q. Tang et al., SID Symposium Digest of Technical Papers, 2018, pp. 414-417 [Non-patent document 2] SHJung et al., Jpn.J.Appl.Phys., Volume 43, No. 3, 2004, Page 1028 [Non-patent document 3] SHLee et al., Appl. Phys. Lett. Vol. 73 (No. 20), 1998, pp. 2882-2883 [Non-patent document 4] SHLee et al., Liquid Crystals Volume 39 (No. 9), 2012, pp. 1141-1148 Summary of the Invention [Problem to be solved by the invention]

[0018] It is therefore an object of the present invention to provide an improved LC medium for use in VA-, PS-VA-, FFS-, polymer-stabilized PS-FFS, UB-FFS-, UBplus- and / or IPS-displays which do not exhibit the above-mentioned disadvantages or exhibit them only to a lesser extent and have improved properties.A further object of the present invention is to provide VA-, PS-VA-, FFS-, UB-FFS-, UBplus- and / or IPS-displays which have good transmittance, high reliability, high VHR values, in particular after backlight exposure, relatively high resistivity, a large operating temperature range, short response times even at low temperatures, low threshold voltages, a large number of grey levels (grey-out), high contrast and wide viewing angles, as well as reduced image sticking.

[0019] VA-, PS-VA-, FFS-, UB-FFS-, UBplus, and / or IPS displays require fast-switching mixtures that exhibit excellent reliability. To achieve fast switching characteristics, low cell gaps, for example, between 2.2 and 3.3 μm, are considered. Meanwhile, highly polar monolayers with dielectric anisotropy values Δε in the range of −15 to −10 are used to achieve fast switching characteristics. However, the solubility limitations inherent in these highly polar monolayers can affect achievable switching times. This can be overcome by combining the highly polar monolayers with highly birefringent monolayers characterized by their birefringence values Δn in the range of 0.22 to 0.30, regardless of their polarity. Therefore, a further object of the present invention is to provide improved LC mixtures comprising highly polar monolayers and highly birefringent monolayers, where the highly birefringent monolayers exhibit a favorably low ratio of rotational viscosity to clearing point γ / cl.p. and excellent solubility in the LC mixture so that the mixture maintains excellent low-temperature stability.

[0020] It has now been found that one or more of these objects can be achieved by providing an LC medium as disclosed and claimed hereinafter. [Means for solving the problem]

[0021] The present invention therefore relates to a liquid-crystalline medium comprising one or more compounds selected from the group of the compounds of the formula III and / or the formula IIIA and / or the formula BC and / or the formula PH-1 and one or more compounds of the formula I.

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] [ka]

[0027] During the ceremony, R 11 , R 12 , R 31 , R 32 , R 81 and R 82 each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, preferably 1 to 7 C atoms, provided that one or more -CH2- groups in these groups are connected in such a way that O atoms are not directly linked to each other, [ka] each independently being replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in which one or more H atoms may be replaced by halogen; X represents S or O, preferably S; A 3 occur independently of each other, a) a 1,4-cyclohexenylene or 1,4-cyclohexylene group, in which one or two non-adjacent CH groups may be replaced by —O— or —S—; b) a 1,4-phenylene group, in which one or two CH groups may be replaced by N, or c) a group selected from the group consisting of spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, and fluorene-2,7-diyl represents provided that groups a), b) and c) may be mono- or polysubstituted by halogen atoms; n represents 0, 1 or 2; Z 3 represent, in each occurrence independently of one another, -CO-O-, -O-CO-, -CF2O-, -OCF2-, -C2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CHO-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond, L 11 , L 12 , L 31 and L 32 each independently represent F, Cl, CF or CHF, and Y 1 , Y 2 , Y 3 , Y 4each independently of one another denotes H, F, Cl, CF3, CHF2, CH3 or OCH3, preferably H, CH3 or OCH3, very preferably H, However, H may be replaced by deuterium.

[0028] The present invention furthermore relates to LC displays comprising a liquid crystal medium as described above and below, in particular VA, PS-VA, FFS, PS-FFS, UB-FFS, UBplus, IPS, PS-IPS or UV 2 ARegarding the display.

[0029] The present invention further provides a method for producing a VA, PS-VA, FFS, PS-FFS, UB-FFS, UBplus, IPS, PS-IPS or UV 2 A relates to the use of a liquid-crystalline medium as described above and below in a display.

[0030] The present invention further relates to a method for preparing an LC medium as described above and below, which comprises mixing one or more compounds of formula I with one or more compounds selected from the group of compounds of formula III and / or formula IIIA and / or formula BC and / or formula PH-1 and optionally further LC compounds and / or additives.

[0031] The present invention further relates to a method for manufacturing an LC display as described above and below, which method comprises the step of filling or otherwise providing an LC medium as described above and below between the substrates of the display.

[0032] The LC media according to the invention, especially when used in LC displays with a small cell gap, for example between 2.2 and 3.3 μm, can achieve one or more of the following advantageous effects: Reduced rotational viscosity, allowing for fast response times High birefringence, a favorably low ratio of rotational viscosity to clearing point γ1 / cl.p., Excellent low temperature stability, Reduced ODF unevenness, High reliability and high VHR values after UV exposure and / or heat treatment, Low threshold voltage, useful for reducing drive voltages and enabling energy-saving displays; Enables a time-, cost-, and energy-efficient production method for LC panels.

[0033] It has been surprisingly found that the LC media according to the invention exhibit a favorable combination of reduced rotational viscosity and high birefringence. The relatively low rotational viscosity and high birefringence allow fast LC media mixtures suitable for very small cell gaps. Furthermore, in terms of reliability, the LC media according to the invention exhibit high VHR values and little or no undesirable mura effects such as edge mura. DETAILED DESCRIPTION OF THE INVENTION

[0034] Alkenyl groups in the compounds of the LC medium as disclosed below are not considered to be within the meaning of the term "polymerizable group" as used herein. The polymerization conditions of the polymerizable compounds of the LC medium are preferably selected so that the alkenyl substituents do not participate in the polymerization reaction. Preferably, the LC media disclosed and claimed in this application do not contain additives that initiate or promote the participation of alkenyl groups in the polymerization reaction.

[0035] Unless otherwise specified, the compounds as disclosed above and below, except for chiral dopants, are preferably selected from achiral compounds.

[0036] As used herein, the expression "UV light having a wavelength of" followed by a predetermined wavelength range (in nm) or a predetermined lower or upper wavelength limit (in nm) means that the UV emission spectrum of the respective radiation source has an emission peak that is preferably the highest peak in the respective spectrum within the predetermined wavelength range or above the predetermined lower wavelength limit or below the predetermined upper wavelength limit, and / or that the UV absorption spectrum of the respective chemical has a long or short wavelength tail that extends within the predetermined wavelength range or above the predetermined lower wavelength limit or below the predetermined upper wavelength limit.

[0037] As used herein, the term "substantially transmit" means that the filter transmits a majority of incident light of a desired wavelength, preferably at least 50% intensity. As used herein, the term "substantially block" means that the filter does not transmit a majority of incident light of undesired wavelengths, preferably at least 50% intensity. As used herein, the term "desired (undesired) wavelength" means, for example, in the case of a bandpass filter, a wavelength within (outside) a given λ range, and in the case of a cutoff filter, a wavelength above (below) a given λ value.

[0038] As used herein, the terms "active layer" and "switchable layer" refer to a layer in an electro-optical display, e.g., an LC display, that contains one or more types of molecules with structural and optical anisotropy, e.g., LC molecules, that undergo a change in molecular orientation upon application of an external stimulus, such as an electric or magnetic field, resulting in a change in the transparency of the layer for polarized or unpolarized light.

[0039] As used herein, the terms "tilt" and "tilt angle" are understood to mean the tilted orientation of the LC molecules of the LC medium in an LC display (herein preferably a PSA display) relative to the cell surface. As used herein, tilt angle means the average angle (less than 90°) between the molecular long axis (LC director) of the LC molecules and the surfaces of the flat, parallel outer plates forming the LC cell. As used herein, low values of tilt angle (i.e., large deviations from the 90° angle) correspond to large tilt. A suitable method for measuring tilt angle is given in the examples. Unless otherwise indicated, the tilt angle values disclosed above and below refer to this measurement method.

[0040] As used herein, the terms "reactive mesogen" and "RM" are understood to mean a compound containing a mesogenic or liquid crystalline backbone and one or more functional groups attached to the backbone that are suitable for polymerization, which functional groups are also referred to as "polymerizable groups" or "P".

[0041] Unless otherwise stated, as used herein, the term "polymerizable compound" is understood to mean a polymerizable monomeric compound.

[0042] The SA-VA displays according to the present invention are polymer-stabilized mode displays that comprise or are produced using an LC medium comprising an RM such as those described below. Consequently, as used herein, the term "SA-VA display" when referring to a display according to the present invention is understood to refer to a polymer-stabilized SA-VA display, even if not explicitly stated otherwise.

[0043] As used herein, the term "low molecular weight compound" is understood as a term in contrast to "polymeric compound" or "polymer" to mean a compound that is monomeric and / or not prepared by a polymerization reaction.

[0044] As used herein, the term "non-polymerizable compound" is understood to mean a compound that does not contain functional groups suitable for polymerization under conditions normally applied for the polymerization of RMs.

[0045] As used herein, the term "mesogenic group" is known to those skilled in the art and described in the literature and refers to a group that, due to the anisotropy of its attractive and repulsive interactions, essentially contributes to the generation of a liquid crystal (LC) phase in low-molecular-weight or polymeric materials. A compound containing a mesogenic group (mesogenic compound) does not necessarily have an LC phase by itself. It is also possible for a mesogenic compound to exhibit LC phase behavior only after mixing with other compounds and / or polymerization. Typical mesogenic groups are, for example, rigid rod- or disc-shaped units. A review of terms and definitions used in connection with mesogens or LC compounds is given in Pure Appl. Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, Vol. 116, pp. 6340-6368.

[0046] As used herein, the term "spacer group", hereinafter also referred to as "Sp", is known to those skilled in the art and described in the literature, see, for example, Pure Appl. Chem. 2001, vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, vol. 116, pp. 6340-6368. As used herein, the term "spacer group" or "spacer" refers to a flexible group, such as an alkylene group, that connects a mesogenic group and a polymerizable group(s) in a polymerizable mesogenic compound.

[0047] Above and below, [ka] represents a trans-1,4-cyclohexylene ring, [ka] represents a 1,4-phenylene ring.

[0048] base [ka] The single bond shown between two ring atoms in can be attached to any free position on the benzene ring.

[0049] In the formulas above and below, R 11 , R 21,22 , R 31,32,33 , R 41,42 , R 51, 52 , R 61 , R 71 , R N1,N2 , R 81,82 , R 91,92,93 , R L1,L2 , R Q , R R1,R2 or L represents an alkyl and / or alkoxy group, which may be linear or branched. It is preferably linear and has 2, 3, 4, 5, 6 or 7 C atoms and therefore preferably represents ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or heptyloxy, further methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

[0050] If one of the above-mentioned terminal groups represents an alkyl group in which one or more CH groups have been replaced by S, this may be linear or branched. It is preferably linear and has 2, 3, 4, 5, 6 or 7 C atoms and therefore preferably represents thiomethyl, thioethyl, thiopropyl, thiobutyl, thiopentyl, thiohexyl or thioheptyl.

[0051] Oxaalkyl preferably represents straight-chain 2-oxapropyl (= methoxymethyl), 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

[0052] When one of the above terminal groups represents an alkoxy or oxaalkyl group, it may also contain one or more additional oxygen atoms, provided that the oxygen atoms are not directly linked to one another.

[0053] If one of the above-mentioned end groups represents an alkyl group in which one or more CH groups have been replaced by -CH=CH-, this may be linear or branched. It is preferably linear and has 2 to 10 C atoms. It therefore stands in particular for vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl, oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl, non-1-, -2-, -3-, -4-, -5-, -6-, -7- or -8-enyl, dec-1-, -2-, -3-, -4-, -5-, -6-, -7-, -8- or -9-enyl.

[0054] When one of the above-mentioned terminal groups represents an alkyl or alkenyl group that is at least monosubstituted with a halogen, this group is preferably linear, and the halogen is preferably F or Cl. In the case of polysubstitution, the halogen is preferably F. The resulting group also includes perfluoro groups. In the case of monosubstitution, the fluorine or chlorine substituent may be in any desired position, but is preferably in the ω-position.

[0055] In another preferred embodiment, R11 , R 21,22 , R 31,32,33 , R 41,42 , R 51,52 , R 61 , R 71 , R N1,N2 , R 81,82 , R 91,92,93 , R L1,L2 , R Q , R R1,R2 One or more of the above-mentioned terminal groups or L may be [ka] -S 1 -F, -OS 1 -F, -O-S1-O-S2 (S in the formula 1 is C 1~12 -Alkylene or C 2~12 -alkenylene, and S 2 is H, C 1~12 -Alkyl or C 2~12 -alkenyl), very preferably [ka] 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.

[0056] Halogen is preferably F or Cl, very preferably F.

[0057] Group-CR 0 =CR 00 - is preferably -CH=CH-.

[0058] -CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e., [ka] Represents.

[0059] Preferred substituents L are, for example, 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, linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms (wherein one or more H atoms may be replaced by F or Cl), optionally substituted silyl having 1 to 20 Si atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms,

[0060] In the formula, R x represents H, F, Cl, CN, a linear, branched or cyclic alkyl chain having 1 to 25 C atoms, with the proviso that one or more non-adjacent CH groups may 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 linked to one another, with the proviso that one or more H atoms may be replaced by F, Cl, P- or P-Sp-, respectively, and

[0061] Y 1 represents a halogen.

[0062] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and also phenyl.

[0063] [ka] wherein L has one of the meanings given above.

[0064] In a preferred embodiment the LC medium according to the invention comprises one or more compounds of formula I, where R 11and R 12 each independently represent a straight-chain alkyl having 1 to 7 C atoms or an alkenyl having 2 to 7 C atoms.

[0065] In a preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula I, preferably selected from the compounds of formulae I-1 to I-9.

[0066] [ka]

[0067] [ka]

[0068] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 7 carbon atoms, alkoxy and alkoxy * each independently represents a linear alkoxy group having 1 to 6 carbon atoms, X represents S or O, preferably S, and L 11 and L 12 each independently represents F or Cl, preferably both represent F.

[0069] Highly preferred compounds of formula I-1 are selected from the compounds of formulae I-1-1 to I-1-10:

[0070] [ka]

[0071] [ka]

[0072] In the formula, alkyl and alkyl * each independently of one another denotes methyl, ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl.

[0073] Highly preferred compounds of formula I-6 are selected from the compounds of formulae I-6-1 to I-6-3:

[0074] [ka]

[0075] In the formula, alkyl represents methyl, ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl; alkoxy represents * represents a linear alkoxy group having 1 to 6 carbon atoms.

[0076] Preferred compounds of formula I are I-1-1, most preferred are compounds PUS-nm, in which n and m each independently represent 1, 2, 3, 4 or 5.

[0077] Preferred compounds of formula III are those of formulae III-1 to III-6:

[0078] [ka]

[0079] in which the occurring radicals have the same meaning as given above in formula III, preferably R 31 and R 32each independently represent an alkyl, alkenyl or alkoxy group having up to 15 C atoms, preferably having 1 to 7 C atoms, preferably one or both of which represent an alkoxy group or a cyclic alkyl having 3 to 6 C atoms, R 33 is an alkyl or alkenyl group having up to 7 C atoms or a group Cy-C m H 2m+1 - represents m and n are the same or different and are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, Cy represents alkyl or alkenyl, each having up to 3 C atoms, or an alicyclic group having 3, 4 or 5 ring atoms, which may be substituted by halogen or CN, preferably cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl, (O) represents O or a single bond; L 31 and L 32 each independently represents F or Cl, preferably both represent F, and Y 3 represents H, F, Cl, CF3, CHF2, CH3 or OCH3, preferably H or CH3.

[0080] In another preferred embodiment the LC medium comprises one or more compounds of the formula III-1 selected from the group of the compounds of the formulae III-1-1 to III-1-20, preferably of the formulae III-1-1 and III-1-11:

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] In the formula, alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms, and alkenyl and alkenyl * each independently represent a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represents a linear alkoxy group having 1 to 6 carbon atoms, L 31 and L 32 each independently represents F or Cl, preferably both represent F.

[0085] Highly preferred compounds of formula III-1-1 are selected from the group consisting of the following subformulae:

[0086] [ka]

[0087] Highly preferred compounds of formula III-1-11 are selected from the group consisting of the following subformulae:

[0088] [ka]

[0089] Highly preferred compounds of formula III-2 are:

[0090] [ka]

[0091] [ka]

[0092] In the formula, alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy, and alkenyl denotes a straight-chain alkenyl group having 2 to 6 C atoms.

[0093] Highly preferred compounds of formula III-6 are selected from the group consisting of the following formulae:

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] In the formula, R 32 is alkyl having 1 to 7 carbon atoms, preferably ethyl, n-propyl or n-butyl, or cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl, or -(CH2) n F (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0098] Preferred compounds of formula III are III-1-1-3, III-1-1-4, III-1-1-5, III-2-7 and III-6-2, with compounds B(S)-2O-O4, B(S)-2O-O5, B(S)-2O-O6, B(S)-1VO-O1(c5) and COB(S)-2-O4 being most preferred.

[0099] Preferably the LC medium further comprises one or more compounds of formula IIIA.

[0100] [ka]

[0101] In the formula, R 31 , R 32 , A 3 , Z 3 , L 31 , L 32 , Y 1 , Y 2 , Y 3 , Y 4 and n has the meaning given above for Formula III.

[0102] In a preferred embodiment of the invention the LC medium comprises one or more compounds of the formula IIIA-1

[0103] [ka]

[0104] wherein the occurring radicals have the same meaning as given above in formula IIIA, preferably R 31 and R 32 each independently represent an alkyl, alkenyl or alkoxy group having up to 15 C atoms, preferably having 1 to 7 C atoms, more preferably one or both of which represent an alkoxy group or a cyclic alkyl having 3 to 6 C atoms, and L 31 and L 32 each independently represents F or Cl, and preferably both represent F.

[0105] In another preferred embodiment the LC medium comprises one or more compounds of the formula IIIA-1 selected from the group of the compounds of the formulae IIIA-1-1 to IIIA-1-20, preferably of the formulae IIIA-1-8 and IIIA-1-18:

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] In the formula, alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms, and alkenyl and alkenyl * each independently represent a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represents a linear alkoxy group having 1 to 6 carbon atoms, L 31 and L 32 each independently represents F or Cl, preferably both represent F.

[0110] Preferably the LC medium comprises one or more compounds of the formula IIIA-1-8 selected from the following sub-formulae:

[0111] [ka]

[0112] Preferably the LC medium comprises one or more compounds of the formula IIIA-1-18 selected from the following sub-formulae:

[0113] [ka]

[0114] In another preferred embodiment of the invention the LC medium comprises one or more compounds of the formula IIIA-2

[0115] [ka]

[0116] In the formula, L 31 and L 32 has the same meaning as given in formula IIIA, (O) represents O or a single bond, R 33 is an alkyl or alkenyl group having up to 7 C atoms or a group Cy-C m H 2m+1 - represents m and n are the same or different and are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, and Cy represents alkyl or alkenyl, each having up to 3 C atoms, or an alicyclic group having 3, 4 or 5 ring atoms, which may be substituted by halogen or CN, and preferably represents cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl.

[0117] The compound of formula IIIA-2 is included in the LC medium either instead of or in addition to, preferably in addition to, the compound of formula III.

[0118] In another preferred embodiment of the invention the LC medium comprises one or more compounds of the formula IIIA-2

[0119] Highly preferred compounds of formula IIIA-2 are:

[0120] [ka]

[0121] In the formula, alkoxy represents a linear alkoxy group having 1 to 6 C atoms.

[0122] In another preferred embodiment the LC medium comprises one or more compounds of the formula IIIA selected from the group of the compounds of the formulae IIIA-3 to IIIA-5

[0123] [ka]

[0124] wherein the occurring groups have the same meaning as given in formula III, and R 31 preferably represents a linear alkyl or a cyclic alkyl, and R 32 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0125] In a preferred embodiment of the invention the LC medium comprises one or more compounds of the formula IIIA-6

[0126] [ka]

[0127] in which the occurring radicals have the same meaning as given in formula III, preferably R 31 and R 32 are each independently an alkyl, alkenyl or alkoxy group having up to 15 C atoms, preferably having 1 to 7 C atoms, more preferably one or both of which represent an alkoxy group.

[0128] Highly preferred compounds of formula IIIA-6 are selected from the group consisting of the following formulae:

[0129] [ka]

[0130] [ka]

[0131] In the formula, R 32 is alkyl having 1 to 7 carbon atoms, preferably ethyl, n-propyl or n-butyl, or cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl, or -(CH2)n F (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0132] In a preferred embodiment of the invention the LC medium comprises at least one compound of formula I, at least one compound of formula III and at least one compound of formula IIIA.

[0133] The LC media according to the invention comprise one or more compounds selected from the group of the difluorodibenzochroman compounds of the formula BC, the chromans of the formula CR and the fluorinated phenanthrenes of the formulae PH-1 and PH-2.

[0134] [ka]

[0135] During the ceremony, R 81 and R 82 each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, preferably 1 to 7 C atoms, provided that one or more -CH2- groups in these groups are connected in such a way that O atoms are not directly linked to each other, [ka] may be replaced independently by —C≡C—, —CF2O—, —OCF2—, —CH═CH—, —O—, —CO—O— or —O—CO—, in which one or more H atoms may be replaced by halogen; R 81 and R 82 preferably, independently of one another, denote alkyl or alkoxy having 1 to 6 C atoms or cyclic alkyl having 3 to 6 C atoms, c is 0, 1 or 2, and Y 1 , Y 2 , Y 3 , Y 4 each independently represent H, F, Cl, CF3, CHF2, CH3 or OCH3.

[0136] The LC media according to the invention comprise compounds of the formulae BC, CR, PH-1, PH-2 preferably in an amount of 3 to 20% by weight, in particular in an amount of 3 to 15% by weight.

[0137] Particularly preferred compounds of formulae BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.

[0138] [ka]

[0139] [ka]

[0140] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 6 C atoms, alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms.

[0141] A particularly preferred compound of formula BC is compound B(A)-2O-O2.

[0142] [ka]

[0143] Particularly preferred compounds of formula PH-1 are compounds B(P)-2O-O3 and B(P)-2O-O4.

[0144] [ka]

[0145] Further preferred embodiments of the LC media according to the invention are listed below, including any combinations thereof.

[0146] Preferably the LC medium further comprises one or more compounds of formula II.

[0147] [ka]

[0148] In the formula, the individual radicals each independently of one another have the following meanings, which may be the same or different at each occurrence: R 21 and R 22 is a linear, branched or cyclic alkyl or alkoxy having 1 to 20 carbon atoms (provided that one or more non-adjacent CH groups are not directly linked to each other by O atoms and / or S atoms, respectively, and are -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -, -C≡C-, [ka] wherein one or more H atoms may be replaced by F, Cl, CN or CF3, respectively), preferably alkyl or alkoxy having 1 to 6 C atoms, R 0 , R 00 is H or alkyl having 1 to 12 C atoms, A 1 and A 2 is expressed as follows: [ka] are preferably groups selected from the formulae A1, A2, A3, A4, A5, A6, A9 and A10, very preferably groups selected from the formulae A1, A2, A3, A4, A5, A9 and A10, Z 1 and Z 2is —CH2CH2—, —CH═CH—, —CF2O—, —OCF2—, —CHO—, —OCH2—, —CO—O—, —O—CO—, —C2F4—, —CF═CF—, —CH═CH—CHO— or a single bond, preferably a single bond, L 1 , L 2 , L 3 and L 4 is F, Cl, OCF3, CF3, CH3, CH2F or CHF2, preferably F or Cl, very preferably F, Y is H, F, Cl, CF3, CHF2 or CH3, preferably H or CH3, very preferably H, L C is CH3 or OCH3, preferably CH3, a1 is 1 or 2, a2 is 0 or 1.

[0149] Preferably the LC medium comprises one or more compounds of formula II selected from the group consisting of the compounds of formulae IIA, IIB, IIC, IID, IIE and IIF.

[0150] [ka]

[0151] In the formula, the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: R 21 and R 22 is H, an alkyl or alkenyl group having up to 15 C atoms, which is unsubstituted or monosubstituted by F, Cl, CN or CF, provided that in addition one or more CH groups in these groups are -O-, -S-, -C≡C-, -CFO-, -OCF-, -CO-O- or -O-CO-, in such a way that the O and / or S atoms are not directly linked to one another, [ka] may be replaced by L1 ~L 4 is F, Cl, CF3 or CHF2, Y is H, F, Cl, CF3, CHF2 or CH3, preferably H or CH3, particularly preferably H, Z 2 , Z 2 is a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCHO-, p is 0, 1 or 2, and q is 0 or 1.

[0152] Preferred compounds of formula IIA, IIB, IIC, IID and IIE are R 22 represents an alkyl or alkoxy group having up to 15 C atoms, very preferably (O)C v H 2v+1 wherein (O) is an oxygen atom or a single bond, and v is 1, 2, 3, 4, 5, or 6.

[0153] Further preferred compounds of formula IIA, IIB, IIC, IID and IIE are 21 or R 22 is preferably [ka] (S in the formula 1 is C 1~12 -Alkylene or C 2~12 -alkenylene, and S 2 is H, C 1~12 -Alkyl or C 2~12 -alkenyl), and very preferably [ka] and represents or contains a cycloalkyl or cycloalkoxy group selected from the group consisting of:

[0154] More preferred compounds of formula IIA, IIB, IIC, IID and IIE are shown below.

[0155] In a preferred embodiment the LC medium comprises one or more compounds of formula IIA selected from the group consisting of the following formulae:

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] In the formula, the index represents 1 or 2, and alkyl and alkyl * each independently represent a linear or branched alkyl group having 1 to 6 C atoms, alkenyl represents a linear or branched alkenyl group having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond, and 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-.

[0169] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of the formulae IIA-2, IIA-8, IIA-10, IIA-16, IIA-18, IIA-40, IIA-41, IIA-42, IIA-43, IIA-67, IIA-69 and IIA-81

[0170] Preferably the LC medium comprises one or more compounds of formula IIA-2 selected from the following sub-formulae:

[0171] [ka]

[0172] Alternatively and preferably, in addition to the compounds of the formulae IIA-2-1 to IIA-2-5 the LC medium comprises one or more compounds of the following formulae:

[0173] [ka]

[0174] More preferably, the LC medium comprises one or more compounds of the formula IIA-10 selected from the following sub-formulae:

[0175] [ka]

[0176] Alternatively and preferably, in addition to the compounds of the formulae IIA-10-1 to IIA-10-6 the LC medium comprises one or more compounds of the following formulae:

[0177] [ka]

[0178] More preferably, the LC medium comprises one or more compounds of the formula IIA-16, which are selected from the following sub-formulae:

[0179] [ka]

[0180] More preferably, the LC medium comprises one or more compounds of the formula IIA-40, which are selected from the following sub-formulae:

[0181] [ka]

[0182] Alternatively and preferably, in addition to the compounds of the formulae IIA-40-1 to IIA-40-5 the LC medium comprises one or more compounds of the following formulae:

[0183] [ka]

[0184] More preferably the LC medium comprises one or more compounds of the formula IIA-42 selected from the following sub-formulae:

[0185] [ka]

[0186] More preferably the LC medium comprises one or more compounds of the formula IIA-67, which are selected from the following sub-formulae:

[0187] [ka]

[0188] More preferably the LC medium comprises one or more compounds of the formula IIA-69 selected from the following sub-formulae:

[0189] [ka]

[0190] More preferably the LC medium comprises one or more compounds of the formula IIA-81 selected from the following sub-formulae:

[0191] [ka]

[0192] Preferred LC media additionally comprise one or more compounds of the formulae IIA-Y.

[0193] [ka]

[0194] In the formula, R 21 and R 22 has one of the meanings given above in formula IIA, L 1 and L 2 are the same or different and represent F or Cl.

[0195] Preferred compounds of formula IIA-Y are selected from the group consisting of the following subformulae:

[0196] [ka]

[0197] [ka]

[0198] In the formula, Alkyl and Alkyl * each independently represents a linear or branched alkyl group having 1 to 6 C atoms, Alkoxy represents a linear or branched alkoxy group having 1 to 6 C atoms, Alkenyl and Alkenyl * each independently represents a linear or branched alkenyl group having 2 to 6 carbon atoms, and O represents an oxygen atom or a single bond. * 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-.

[0199] Particularly preferred compounds of formula IIA-Y are selected from the group consisting of the following subformulae:

[0200] [ka]

[0201] In the formula, Alkoxy and Alkoxy* has the meaning defined above and preferably denotes methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentyloxy.

[0202] In another preferred embodiment the LC medium comprises one or more compounds of formula IIB selected from the group consisting of the formulae IIB-1 to IIB-26.

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] [ka]

[0208] In the formula, alkyl and alkyl * are each independently a linear or branched alkyl group having 1 to 6 C atoms, a linear or branched alkenyl group having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond, and 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-.

[0209] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of the formulae IIB-2, IIB-11 and IIB-17.

[0210] Preferably the LC medium comprises one or more compounds of the formula IIB-11 selected from the following sub-formulae:

[0211] [ka]

[0212] Alternatively and preferably, in addition to the compounds of the formulae IIB-11-1 to IIB-11-5 the LC medium comprises one or more compounds of the formulae IIB-11a-1 to IIB-11a-5.

[0213] [ka]

[0214] Preferably the LC medium comprises one or more compounds of the formula IIB-17 selected from the following sub-formulae:

[0215] [ka]

[0216] In another preferred embodiment the LC medium comprises one or more compounds of formula IIC selected from formula IIC-1:

[0217] [ka]

[0218] In the formula, alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms, preferably in an amount of 0.5% to 5% by weight, in particular 1% to 3% by weight.

[0219] In another preferred embodiment the LC medium comprises one or more compounds of formula IID selected from the group consisting of the following formulae:

[0220] [ka]

[0221] [ka]

[0222] [ka]

[0223] In the formula, alkyl and alkyl * are each independently a linear or branched alkyl group having 1 to 6 C atoms, a linear or branched alkenyl group having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond, and 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-.

[0224] Particularly preferred LC media according to the invention comprise one or more compounds of the formulae IID-1, IID-4, IID-12 and / or IID-19.

[0225] Highly preferred compounds of formula IID are selected from the following subformulae of IID-1:

[0226] [ka]

[0227] [ka]

[0228] [ka]

[0229] [ka]

[0230] wherein v is 1, 2, 3, 4, 5, or 6.

[0231] Highly preferred compounds of formula IID are selected from the following subformulae of IID-4:

[0232] [ka]

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] wherein v is 1, 2, 3, 4, 5, or 6.

[0237] Highly preferred compounds of formula IID are selected from the following subformulae of IID-12:

[0238] [ka]

[0239] [ka]

[0240] [ka]

[0241] wherein v is 1, 2, 3, 4, 5, or 6.

[0242] In a preferred embodiment the LC medium comprises one or more compounds of formula IID-12a.

[0243] [ka]

[0244] In the formula, R 21 , Y and q have the meanings given in formula IID, and R 23 teeth [ka] wherein r is 0, 1, 2, 3, 4, 5, or 6, and s is 1, 2, or 3.

[0245] Preferred compounds of formula IID-10a are compounds IID-12a-1 to IID-12a-14.

[0246] [ka]

[0247] [ka]

[0248] [ka]

[0249] Highly preferred compounds of formula IID are selected from the following subformulae of IID-19:

[0250] [ka]

[0251] [ka]

[0252] [ka]

[0253] [ka]

[0254] wherein v is 1, 2, 3, 4, 5, or 6.

[0255] In a preferred embodiment the LC medium comprises one or more compounds of formula IIE selected from the group consisting of the following formulae:

[0256] [ka]

[0257] [ka]

[0258] [ka]

[0259] [ka]

[0260] [ka]

[0261] [ka]

[0262] [ka]

[0263] [ka]

[0264] [ka]

[0265] [ka]

[0266] [ka]

[0267] [ka]

[0268] In the formula, the index represents 1 or 2, and alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms, alkenyl represents a linear alkenyl group having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond, and 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-.

[0269] Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of the formulae IIE-2, IIE-8, IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39 and IIE-40

[0270] Preferably the LC medium comprises one or more compounds of formula IIE-2 selected from the following sub-formulae:

[0271] [ka]

[0272] Preferably the LC medium comprises one or more compounds of the formula IIE-10 selected from the following sub-formulae:

[0273] [ka]

[0274] In another preferred embodiment the LC medium comprises one or more compounds of formula IIF selected from the group consisting of the following formulae:

[0275] [ka]

[0276] In the formula, alkyl and alkyl * each independently represents a linear or branched alkyl group having 1 to 6 carbon atoms.

[0277] Preferably the LC medium comprises one or more compounds of formula IIF-2 selected from the following sub-formulae:

[0278] [ka]

[0279] Particularly preferred LC media according to the invention comprise one or more compounds selected from the formulae IIA-2, IIA-8, IIA-10, IIA-16, IIA-18, IIA-40, IIA-41, IIA-42, IIA-43, IIA-67, IIA-69, IIA-81, IIB-2, IIB-10, IIB-16, IIC-1 and IID-1, IID-4, IID-12, IID-19, IIE-2, IIE-8, IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39, IIE-40 and IIF-2 and sub-formulae thereof.

[0280] The proportion of compounds of formula IIA and / or IIB in the mixture as a whole is preferably at least 20% by weight.

[0281] In a preferred embodiment the LC medium comprises one or more compounds of formula IV

[0282] [ka]

[0283] During the ceremony, R 41 is an unsubstituted alkyl group having 1 to 7 C atoms (but in addition one or more CH2 groups, [ka] ) or an unsubstituted alkenyl group having 2 to 7 C atoms, preferably an n-alkyl group, particularly preferably having 2, 3, 4 or 5 C atoms, and R 42 represents an unsubstituted alkyl group having 1 to 7 C atoms or a cyclic alkyl group having 3 to 6 C atoms or an unsubstituted alkoxy group having 1 to 6 C atoms (both preferably having 2 to 5 C atoms), an unsubstituted alkenyl group having 2 to 7 C atoms, preferably having 2, 3 or 4 C atoms, more preferably a vinyl group or a 1-propenyl group, in particular a vinyl group.

[0284] The compound of formula IV is preferably selected from the group of compounds of formulae IV-1 to IV-4:

[0285] [ka]

[0286] During the ceremony, alkyl and alkyl' independently represent an alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms, alkenyl represents an alkenyl group having 2 to 5 C atoms, preferably 2 to 4 C atoms, particularly preferably 2 C atoms; alkenyl' represents an alkenyl group having 2 to 5 C atoms, preferably 2 to 4 C atoms, particularly preferably 2 to 3 C atoms, Alkoxy represents alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms.

[0287] Preferably the LC medium comprises one or more compounds selected from the compounds of the formulae IV-1-1 to IV-1-14:

[0288] [ka]

[0289] [ka]

[0290] In the formula, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl.

[0291] Very preferably, the LC medium according to the invention comprises one or more compounds of the formulae IV-2-1 and / or IV-2-2.

[0292] [ka]

[0293] Very preferably, the LC medium according to the invention comprises a compound of the formula IV-3, in particular selected from the compounds of the formulae IV-3-1 to IV-3-9

[0294] [ka]

[0295] The LC media according to the invention preferably comprise one or more compounds CC-nV and / or CC-n-Vm, in particular CC-3-V, CC-4-V, CC-3-V1 and / or CC-4-V1, in a total concentration in the range from 15 to 70%, preferably from 25 to 55%, very preferably from 30 to 50%. CC-3-V is preferably used in a concentration of from 5 to 60%, in particular from 10 to 55%.

[0296] In another embodiment the LC medium according to the invention comprises one or more compounds of the formula IV-3 selected from the compounds of the formulae IV-3-10 to IV-3-25

[0297] [ka]

[0298] [ka]

[0299] Very preferably, the LC medium according to the invention comprises one or more compounds of the formula IV-4, in particular selected from the compounds of the following formulae:

[0300] [ka]

[0301] In another embodiment the LC medium comprises one or more compounds of formula IV-4 and its sub-formulae, in which one or both of "alkenyl" and "alkenyl'" are [ka] where m is 0, 1 or 2 and n is 0, 1 or 2.) and are very preferably selected from the compounds of the formulae IV-4-3 to IV-4-6:

[0302] Very preferably, the LC medium according to the invention comprises one or more compounds of formula IV-1 or any subformula thereof and / or one or more compounds of formula IV-3 or any subformula thereof and / or one or more compounds of formula IV-4 or any subformula thereof, with the proviso that the concentration of these compounds of formula IV-1 is in the range from 1% to 30%.

[0303] The LC media according to the invention preferably additionally comprise one or more compounds of the formula IVa.

[0304] [ka]

[0305] During the ceremony, R 41 and R 42 each independently represent a linear alkyl, alkoxy, alkenyl, alkoxyalkyl or alkenyloxy group having up to 12 C atoms or a cyclic alkyl having 3 to 6 C atoms, [ka] Z 4 represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8- or -CF=CF-.

[0306] Preferred compounds of formula IVa are shown below.

[0307] [ka]

[0308] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms.

[0309] The LC media according to the invention preferably comprise at least one compound of the formula IVa-1 and / or IVa-2.

[0310] The proportion of compounds of formula IVa in the mixture as a whole is preferably at least 5% by weight.

[0311] Preferably the LC medium comprises one or more compounds of the formulae IVb-1 to IVb-3.

[0312] [ka]

[0313] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 6 C atoms, preferably alkyl represents methyl, and alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms.

[0314] The proportion of the compounds of the formulae IV-1 to IV-3 in the entire mixture is preferably at least 3% by weight, in particular 5% by weight or more.

[0315] Among the compounds of formulae IVa-1 to IVa-4, the compound of formula IVa-2 is particularly preferred.

[0316] Among the compounds of formulae IVb-1 to IVb-3, the compound of formula IVb-2 is particularly preferred.

[0317] Particularly preferred compounds of formulae IV-1 to IV-3 are selected from the group consisting of the following formulae:

[0318] [ka]

[0319] In the formula, alkyl * represents an alkyl group having 1 to 6 C atoms, preferably n-propyl.

[0320] The LC media according to the invention particularly preferably comprise one or more compounds of the formulae IVb-1-1, IVb-2-3 and / or IVb-2-4.

[0321] In another preferred embodiment the LC medium according to the invention comprises one or more compounds of formula V

[0322] [ka]

[0323] During the ceremony, R 51 and R 52 represent, independently of one another, H, an alkyl, alkoxy or alkenyl group having up to 15 C atoms, which is unsubstituted or monosubstituted with F, Cl, CN or CF3 or at least monosubstituted with a halogen, provided that in addition one or more CH2 groups in these groups are not directly linked to one another and are substituted with -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -CO-O-, -O-CO-, [ka] and preferably represents alkyl having 1 to 7 C atoms, preferably n-alkyl, particularly preferably n-alkyl having 1 to 5 C atoms, alkoxy having 1 to 6 C atoms, preferably n-alkoxy, particularly preferably n-alkoxy having 2 to 5 C atoms, alkoxyalkyl having 2 to 7 C atoms, preferably 2 to 4 C atoms, alkenyl or alkenyloxy, preferably alkenyloxy, [ka] During the ceremony, [ka] Z 51 , Z 52 each independently represent -CH-CH-, -CH-O-, -CH=CH-, -C≡C-, -COO- or a single bond, preferably -CH-CH-, -CH-O- or a single bond, particularly preferably a single bond, and n is 1 or 2, However, one or more compounds of formula V are different from formula I.

[0324] The compound of formula V is preferably selected from the compounds of formulae V-1 to V-17.

[0325] [ka]

[0326] [ka]

[0327] In the formula, R 51 and R 52 has the meaning as indicated above.

[0328] R 51 and R 52 are each independently a straight-chain alkyl or alkenyl.

[0329] Preferred media comprise one or more compounds of formula V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15 and / or V-16.

[0330] The LC media according to the invention very particularly preferably comprise compounds of the formulae V-10 and / or IV-1, in particular in an amount of 5 to 30%.

[0331] Preferred compounds of formula V-10 are shown below.

[0332] [ka]

[0333] The LC media according to the invention particularly preferably comprise tricyclic compounds of the formulae V-10a and / or V-10b in combination with one or more bicyclohexyl compounds of the formula IV-1. The total proportion of compounds of the formulae V-10a and / or V-10b in combination with one or more compounds selected from the bicyclohexyl compounds of the formula IV-1 is 5 to 40%, very particularly preferably 15 to 35%.

[0334] Particularly preferred LC media include compounds V-9a and IV-1-1.

[0335] [ka]

[0336] Compounds V-10a and IV-1-1 are preferably present in the mixture in a concentration of 5 to 35%, very preferably 10 to 25%, based on the mixture as a whole.

[0337] Preferred LC media comprise at least one compound selected from the group of compounds below.

[0338] [ka]

[0339] In the formula, R 41 , R 42 , R 51 and R 52 has the meaning as indicated above. Preferably, in compounds V-6, I and IV, R 41 and R 51 represents alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms, respectively, and R 42 and R 52 represents alkenyl having 2 to 6 carbon atoms. Preferably, in compound V-14, R 51 represents alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms, R 52 represents alkyl having 1 to 6 C atoms.

[0340] In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of the formula V-7, preferably selected from the compounds of the formulae V-7a to V-7e

[0341] [ka]

[0342] In the formula, alkyl represents an alkyl group having 1 to 7 C atoms, alkenyl represents an alkenyl group having 2 to 7 C atoms, and cycloalkyl represents a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl.

[0343] Highly preferred compounds of formulae V-7a to V-7e are selected from the compounds of the following sub-formulae:

[0344] [ka]

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] In the formula, alkyl represents ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl.

[0349] R 51 and R 52 Further preferred are compounds of formula V, in which independently of one another, denote linear alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0350] In a preferred embodiment of the invention, the LC medium additionally comprises one or more compounds of the formulae VI-1 to VI-22.

[0351] [ka]

[0352] [ka]

[0353] [ka]

[0354] During the ceremony, R 61 represents a linear alkyl or alkoxy group having 1 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms, (O) represents O or a single bond, X represents F, Cl, OCF3 or OCHF2, Lx represents H or F; m is 0, 1, 2, 3, 4, 5, or 6; and n is 0, 1, 2, 3, or 4.

[0355] R 61 preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0356] X preferably represents F or OCH3, very preferably F.

[0357] The LC media according to the invention preferably contain terphenyls of the formulae VI-1 to VI-22 in an amount of 2 to 30% by weight, in particular 5 to 20% by weight.

[0358] Particularly preferred are compounds of formulae VI-2, VI-18 and VI-20 in which X represents F. In these compounds, R 61 preferably denotes alkyl, further alkoxy, each having 1 to 5 C atoms. In the compounds of formula VI-18, R 61 preferably represents alkyl or alkenyl, especially alkyl. In the compound of formula VI-19, R 61 In the compounds of the formulae VI-20 to VI-22, X preferably represents F.

[0359] Terphenyls of the formulae VI-1 to VI-22 are preferably employed in the LC media according to the invention, if the mixture has a Δn value of 0.1 or more. Preferred LC media contain 2 to 20% by weight of one or more terphenyl compounds selected from the group of the compounds of the formulae VI-1 to VI-22

[0360] In a preferred embodiment of the invention, the LC medium additionally comprises one or more compounds of the formulae VII-1 to VII-9.

[0361] [ka]

[0362] During the ceremony, R 71 are each independently a group represented by R in formula IIA. 21 has one of the meanings given in w and x each independently represent 1 to 6;

[0363] Particularly preferred are LC media which comprise at least one compound of the formula VII-9.

[0364] LC medium comprising one or more substances which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, compounds of the formulae N-1 to N-5.

[0365] [ka]

[0366] R in the formula N1 and R N2 are each independently R 21 and preferably represents straight-chain alkyl, straight-chain alkoxy or straight-chain alkenyl, Z N1 and Z N2 each independently represent -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CHO-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond.

[0367] LC medium comprising one or more indane compounds of formula In

[0368] [ka]

[0369] During the ceremony, R 91 , R 92 , R 93each independently represent a linear alkyl, alkoxy, alkoxyalkyl or alkenyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 6 C atoms, Also R 92 and R 93 may also represent halogen, preferably F, [ka] represents i represents 0, 1 or 2.

[0370] Preferred compounds of formula In are compounds of formulae In-1 to In-16 shown below.

[0371] [ka]

[0372] [ka]

[0373] [ka]

[0374] Compounds of formulae In-1, In-2, In-3 and In-4 are particularly preferred.

[0375] The compounds of the formula In and the subformulae In-1 to In-16 are preferably employed in the LC media according to the invention in a concentration of 5% by weight or more, in particular 5 to 30% by weight, very particularly preferably 5 to 25% by weight.

[0376] LC medium comprising one or more compounds of the formulae L-1 to L-8.

[0377] [ka]

[0378] During the ceremony, R L1 and R L2 are each independently R in the above formula IIA. 21 where alkyl represents an alkyl group having 1 to 6 carbon atoms. The parameter s represents 1 or 2.

[0379] The compounds of the formulae L-1 to L-8 are preferably used in concentrations of 5 to 15% by weight, in particular 5 to 12% by weight, very particularly preferably 8 to 10% by weight.

[0380] LC medium comprising one or more quaterphenyl compounds selected from the following formulae:

[0381] [ka]

[0382] During the ceremony, R Q is alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which groups may be fluorinated, X Q is F, Cl, a halogenated alkyl or alkoxy having 1 to 6 C atoms or a halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, L Q1 ~L Q6 are each independently H or F, with the proviso that L Q1 ~L Q6 At least one of is F.

[0383] Preferred compounds of formula Q are Q is linear alkyl having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

[0384] Preferred compounds of formula Q are Q3 and L Q4is F.

[0385] Further preferred compounds of formula Q are Q3 , L Q4 and L Q1 and L Q2 One or two of these are F.

[0386] Preferred compounds of formula Q are X Q represents F or OCF3, very preferably F.

[0387] The compounds of formula Q are preferably selected from the following sub-formulae:

[0388] [ka]

[0389] In the formula, R Q has one of the meanings of formula Q or one of the preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl.

[0390] Especially R Q Particularly preferred are compounds of formula Q1 wherein is n-propyl or cyclopentyl.

[0391] Preferably the proportion of compounds of formula Q in the LC medium is from >0 to 5% by weight, very preferably from 0.05 to 2% by weight, more preferably from 0.1 to 1% by weight, most preferably from 0.1 to 0.8% by weight.

[0392] Preferably the LC medium comprises 1 to 5, preferably 1 or 2, compounds of formula Q.

[0393] Adding a quaterphenyl compound of formula Q to the LC mixture of a polymerizable LC medium can reduce ODF unevenness while maintaining high UV absorption, enabling rapid and complete polymerization, strong and rapid tilt angle generation, and increasing the UV stability of the LC medium.

[0394] In addition, the compound of formula Q with positive dielectric anisotropy can be added to an LC medium with negative dielectric anisotropy to increase the dielectric constant ε ∥ and ε ⊥ In particular, the dielectric constant ε can be controlled by keeping the dielectric anisotropy Δε constant. ∥ It is possible to achieve high values of ρ, thereby reducing kickback voltage and reducing image sticking.

[0395] The LC media according to the invention preferably have

[0396] one or more compounds of the formula I or sub-formulas thereof, preferably of the formula I-1, preferably in a proportion of 2 to 30% by weight, very preferably 5 to 20% by weight, most preferably 8 to 12% by weight, based on the total mixture;

[0397] and / or one or more compounds of the formula III, preferably of the formula III-1 and / or III-6, very preferably of the formula III-1-1 and / or III-6-2, with the formula III-1 preferably in a total concentration in the range of 2 to 20% by weight, very preferably 7 to 14% by weight, based on the total mixture, and the formula III-6 preferably in a total concentration in the range of 2 to 20% by weight, very preferably 8 to 12% by weight, based on the total mixture;

[0398] and / or one or more compounds of the formula IIIA, preferably of the formula IIIA-1, very preferably of the formula IIIA-1-6, in a total concentration preferably in the range of 2 to 8% by weight, very preferably in the range of 3 to 5% by weight, based on the total mixture;

[0399] and / or one or more compounds of the formula BC or sub-formulas thereof, preferably in a total concentration in the range of 0.1 to 10% by weight, more preferably 1 to 7% by weight, very preferably 1 to 4% by weight, based on the total mixture;

[0400] and / or one or more compounds of the formula PH-1 or sub-formulas thereof, preferably in a total concentration in the range of 0.1 to 10% by weight, more preferably 1 to 7% by weight, very preferably 1 to 4% by weight, based on the total mixture;

[0401] and / or one or more compounds of formula II or any of its sub-formulas, preferably of formulae IIA, IIB, IIC, IID, IIE and IIF, preferably in a total concentration in the range of 20 to 70%, more preferably 25 to 65%, particularly preferably 30 to 65%, based on the total mixture;

[0402] and / or one or more compounds of the formula IV or sub-formulas thereof, preferably of the formulae IV-1, IV-3 and IVa-2, preferably in a total concentration in the range from 10 to 60% by weight, more preferably from 13 to 55% by weight, particularly preferably from 15 to 50% by weight, based on the mixture as a whole;

[0403] and / or one or more compounds of the formula V or sub-formulas thereof, preferably of the formula V-10, preferably in a total concentration in the range from 0.1 to 30% by weight, more preferably from 0.5 to 25% by weight, particularly preferably from 1 to 15% by weight, based on the mixture as a whole;

[0404] and / or one or more compounds of the formula VI or sub-formulas thereof, preferably of the formula VI-1, in a total concentration preferably in the range from 0.5 to 20% by weight, more preferably from 0.75 to 15% by weight, particularly preferably from 1 to 10% by weight, based on the mixture as a whole Includes.

[0405] Further preferred embodiments are listed below, where the acronyms used are explained in Table B, where n and m are each independently an integer from 1 to 7:

[0406] one or more PUS-nm compounds, preferably in a proportion of 2 to 30% by weight, very preferably 5 to 20% by weight, most preferably 8 to 12% by weight, based on the total mixture;

[0407] and / or one or more B(S)-nO-Om compounds, in particular B(S)-2O-O4, B(S)-2O-O5, B(S)-2O-O6, in a total concentration preferably in the range of 2 to 30% by weight, more preferably 7 to 14% by weight, based on the total mixture;

[0408] and / or one or more COB(S)-n-Om compounds, in particular COB(S)-2-O4 compounds, preferably in a total concentration ranging from 2 to 20% by weight, more preferably from 8 to 12% by weight, based on the total mixture;

[0409] and / or one or more B-nO-Om, in particular B-2O-O5, compounds, preferably in a total concentration in the range of 2 to 8% by weight, very preferably 3 to 5% by weight, based on the total mixture;

[0410] and / or one or more compounds B(P)-nO-Om, in particular B(P)-2O-O3 and / or B(P)-2O-O4, preferably in a total concentration in the range of 0.1 to 10% by weight, more preferably 1 to 7% by weight, very preferably 1 to 4% by weight, based on the mixture as a whole;

[0411] and / or one or more compounds B(A)-nO-Om, in particular B(A)-2O-O2, preferably in a total concentration in the range of 0.1 to 10% by weight, more preferably 1 to 7% by weight, very preferably 1 to 4% by weight, based on the mixture as a whole;

[0412] and / or one or more compounds Y-nO-Om, CY-n-Om, CPY-n-Om, CCY-n-Om, CCY-Vn-Om, CLY-n-Om, CLOY-n-Om, LOY-n-Om, COY-n-Om, CCOY-n-Om, CCEY-n-Om, PY-n-Om, PYP-nm and / or CAIY-n-Om, in particular Y-4O-O4, CY-3-O2, CPY-3-O2, CCY-3-O2, CCY-5-O2, CLY-3-O2, CLY-3-O3, CLY-4-O2, CLY-5-O2, CLOY-3-O2, LOY-3-O2, PYP-2-3, PYP-2-4 and / or CAIY-3-O2, preferably in a total concentration in the range of 20-70%, more preferably 25-65%, based on the whole mixture;

[0413] and / or one or more compounds CC-nm, CC-nV, CC-n-Vm and / or CP-n-Om, preferably CC-3-4, CC-3-5, CC-3-V, CC-3-V1, CC-4-V1 and / or CP-3-O2, preferably in a total concentration in the range of 10 to 60%, more preferably 13 to 55%, particularly preferably 15 to 50%, based on the total mixture;

[0414] and / or one or more compounds CY-n-Om, in particular CY-3-O4, CY-5-O4 and / or CY-3-O2, preferably in a total concentration in the range of 5 to 30%, preferably 10 to 20%, based on the total mixture;

[0415] and / or one or more compounds PY-n-Om and / or PY-nO-Om, in particular PY-1-O2, PY-2-O2 and / or PY-3-O2, preferably in a total concentration in the range of 5 to 40%, preferably 10 to 30%, based on the entire mixture;

[0416] and / or one or more compounds CPY-n-Om and / or CPY-Vn-m, in particular CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably in a concentration of more than 5%, in particular 7% to 20%, based on the mixture as a whole,

[0417] and / or one or more compounds CCY-n-Om, in particular CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and / or CCY-5-O2, preferably in a concentration of more than 3%, in particular 5-15%, based on the mixture as a whole;

[0418] and / or one or more compounds CPY-n-Om and CY-n-Om, preferably in a concentration of 10 to 80%, based on the total mixture,

[0419] and / or one or more compounds CPY-n-Om and PY-n-Om, preferably CPY-2-O2 and / or CPY-3-O2 and PY-3-O2 or PY-1-O2, preferably in a concentration of 5 to 20%, more preferably 10 to 15%, based on the total mixture,

[0420] and / or one or more compounds selected from the group consisting of CCH-13, CCH-23, CCH-24, CCH-25, CCH-34, CCH-35, CCH-301 and CCH-303, preferably in a total concentration of 3 to 40%, preferably 3 to 25%, based on the total mixture,

[0421] and / or one or more compounds selected from the group consisting of CC-2-V1, CC-3-V1, CC-3-V2, CC-4-V1, CC-3-V, CC-4-V and CC-5-V, preferably in a total concentration of 3 to 40%, more preferably 5 to 30%, based on the total mixture,

[0422] and / or one or more compounds selected from the group consisting of one or more CCP-nm and / or CCP-Vn-m and / or CPP-nm, preferably CCP-3-1, CCP-V-1, CCP-V2-1 and CPP-3-2, preferably in a total concentration of 4 to 35%, preferably 5 to 25%, based on the total mixture,

[0423] and / or one or more compounds selected from the group consisting of one or more CLP-nm, CLP-n-Om and / or CLP-Vn-m, preferably CLP-3-1, CLP-3-2, CLP-3-O1, CLP-3-O2 and CLP-V-1, preferably in a total concentration of 1 to 25%, preferably 2 to 15%, based on the total mixture,

[0424] and / or one or more compounds selected from the group consisting of PYP-nm, PGIY-n-Om and PGP-n-2V, preferably in a total concentration of 2 to 20%, more preferably 2 to 15%, most preferably 2 to 10%, based on the total mixture,

[0425] and / or one or more compounds selected from the group consisting of one or more PP-nm and / or PP-n-nVm, preferably PP-1-3, PP-1-4, PP-1-5, PP-1-2V and PP-1-2V1, preferably in a total concentration of 1 to 15%, preferably 2 to 10%, based on the total mixture,

[0426] and / or one or more compounds PPGU-3-F, preferably at a concentration of 0.1% to 3% based on the total mixture; Includes.

[0427] The liquid crystal media according to the invention advantageously have a nematic phase preferably at temperatures from -20°C to 70°C, particularly preferably from -30°C to 80°C, very particularly preferably from -40°C to 90°C.

[0428] The LC media according to the invention have a clearing temperature of 70°C or higher, preferably 85°C or higher, for example between 85°C and 125°C.

[0429] The expression "having a nematic phase" as used herein means, on the one hand, that neither a smectic phase nor crystallization is observed at the corresponding low temperature, and, on the other hand, that clearing does not occur upon heating from the nematic phase. Low-temperature studies are carried out in a flow viscometer at the corresponding temperature and confirmed by storage for at least 100 hours in test cells with layer thicknesses corresponding to electro-optical applications. An LC medium is considered stable at this temperature if the storage stability of the corresponding test cells at -20°C is 1000 hours or more. At temperatures of -30°C and -40°C, the corresponding times are 500 hours and 250 hours, respectively. At higher temperatures, the clearing point is measured in capillaries by conventional methods.

[0430] The liquid crystal mixture preferably has a nematic phase range of at least 60 K and a maximum of 30 mm 2 ·s -1 Flow viscosity ν 20 It has.

[0431] The mixture is nematic at temperatures below -20°C, preferably below -30°C, and very preferably below -40°C.

[0432] The birefringence value Δn of the liquid crystal mixture is generally between 0.07 and 0.16, preferably between 0.08 and 0.15, very preferably between 0.09 and 0.15. In a preferred embodiment of the invention, the LC medium has a birefringence in the range from 0.075 to 0.147, preferably from 0.090 to 0.145, in particular from 0.1150 to 0.1420.

[0433] The liquid crystal mixture according to the invention has a dielectric anisotropy Δε of −1.5 to −8.0, preferably of −2.6 to −6.0.

[0434] The rotational viscosity γ1 at 20° C. is preferably 245 mPa·s or less, particularly 240 mPa·s or less. In a preferred embodiment, the rotational viscosity γ1 at 20° C. is 215 mPa·s or less, particularly 200 mPa·s or less.

[0435] The liquid-crystalline media according to the invention have relatively low values of the threshold voltage (V0): they are preferably in the range from 1.7 V to 3.0 V, particularly preferably ≦2.7 V, very particularly preferably ≦2.5 V.

[0436] For the present invention, the term "threshold voltage" relates to the capacitive threshold (V0), also called the Freederickss threshold, unless otherwise specified.

[0437] In addition, the liquid-crystalline media according to the invention have high values for the voltage holding ratio in liquid-crystal cells.

[0438] In general, liquid crystal media with a low addressing voltage or threshold voltage show a lower voltage holding ratio than those with a high addressing voltage or threshold voltage, and vice versa.

[0439] In the present invention, the term "dielectrically positive compound" refers to a compound with Δε > 1.5, the term "dielectrically neutral compound" refers to one with -1.5 ≦ Δε ≦ 1.5, and the term "dielectrically negative compound" refers to one with Δε < -1.5. The dielectric anisotropy of a compound is determined herein by dissolving 10% of the compound in a liquid crystal host and measuring the capacitance of the resulting mixture in at least one test cell with a layer thickness of 20 μm in each case and with homeotropic and homogeneous surface alignment at 1 kHz. The measurement voltage is typically between 0.5 V and 1.0 V, but is always below the capacitance threshold of each liquid crystal mixture under consideration.

[0440] All temperature values given for this invention are in °C.

[0441] The LC media according to the invention are suitable for all FFS (fringe field switching) and UB-FFS (ultra-brightness FFS) applications with a negative Δε. They are also suitable for all VA-TFT (vertical alignment-thin film transistor) applications, such as VAN (vertically aligned nematic), MVA (multidomain VA), (S)-PVA (super patterned VA), ASV (advanced super view or axially symmetric VA), PSA (polymer sustained VA) and PS-VA (polymer stabilized VA). They are also suitable for IPS (in-plane switching) applications with a negative Δε.

[0442] The nematic LC medium in the displays according to the invention generally comprises two components A and B which themselves consist of one or more individual compounds.

[0443] Component A has a significantly negative dielectric anisotropy, giving the nematic phase a dielectric anisotropy of -0.5 or less.

[0444] The proportion of component A is preferably between 45 and 100%, in particular between 60 and 85%.

[0445] For component A, one (or more) individual compounds are preferably selected that have a Δε value of less than or equal to −1.5, this value having to be more negative the smaller the proportion of component A in the overall mixture.

[0446] Component B is a dielectrically neutral compound with -1.5≦Δε≦1.5. Furthermore, component B has pronounced nematogenicity and a 30 mm 2 ·s -1 Less than 25mm, preferably 2 ·s -1 It has the following flow viscosity:

[0447] Many suitable materials are known to those skilled in the art from the literature.

[0448] Particularly preferred individual compounds in component B have a viscosity of 18 mmHg at 20°C. 2 ·s -1 Less than 12mm, preferably 2 ·s -1 It is a very low viscosity nematic liquid crystal having the following flow viscosity:

[0449] Component B is unidirectionally or enantiomerically nematic, does not have a smectic phase, and can prevent the occurrence of smectic phases in LC media down to very low temperatures. For example, when various highly nematogenic materials are added to a smectic liquid crystal mixture, the nematogenicity of these materials can be compared through the degree of smectic phase suppression achieved.

[0450] The mixture may also contain a component C which comprises compounds having a dielectric anisotropy of Δε≧1.5. These so-called positive compounds are generally present in mixtures of negative dielectric anisotropy in amounts of up to 20% by weight, based on the total mixture.

[0451] In addition to compounds of formula I, compounds of formula III, compounds of formula IIIA, compounds of formula BC, compounds of formula PH-1 and compounds of formulae IIA, IIB, IIC, IID, IIE and IIF, other components may also be present, for example in amounts of up to 45%, preferably up to 35%, in particular up to 10% of the total mixture.

[0452] The other components are preferably selected from nematic or nematogenic substances, in particular known substances, from the classes of azoxybenzene, benzylideneaniline, biphenyl, terphenyl, phenyl or cyclohexylbenzoate, phenyl or cyclohexylcyclohexanecarboxylate, phenylcyclohexane, cyclohexylbiphenyl, cyclohexylcyclohexane, cyclohexylnaphthalene, 1,4-biscyclohexylbiphenyl or cyclohexylpyrimidine, phenyl or cyclohexyldioxane, optionally halogenated stilbenes, benzyl phenyl ethers, tolanes and substituted cinnamic acid esters.

[0453] The most important compounds suitable as components of this type of liquid crystal phase can be characterized by the formula R:

[0454] [ka]

[0455] wherein L and E each represent a carbocyclic or heterocyclic ring system from the group formed by 1,4-disubstituted benzene and cyclohexane rings, 4,4'-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydronaphthalene, quinazoline and tetrahydroquinazoline, G is -CH=CH-, -N(O)=N-, -CH=CQ-, -CH=N(O)-, -C≡C-, -CH2-CH2-, -CO-O-, -CH2-O-, -CO-S-, -C Represents H2-S-, -CH=N-, -COO-Phe-COO-, -CF2O-, -CF=CF-, -OCF2-, -OCH2-, -(CH2)4-, -(CH2)3O-, or a CC single bond, Q represents a halogen, preferably chlorine, or represents -CN, and R R1 and R R2represents alkyl, alkenyl, alkoxy, alkoxyalkyl or alkoxycarbonyloxy, each having up to 18, preferably up to 8, carbon atoms, or one of these groups represents CN, NC, NO, NCS, CF, SF, OCF, F, Cl or Br.

[0456] In most of these compounds, R R1 and R R2 are different from each other, and one of these groups is usually an alkyl or alkoxy group. Other variations of the proposed substituents are also common. Many such substances or mixtures thereof are commercially available. All of these substances can be prepared by methods known from the literature.

[0457] It will be appreciated by those skilled in the art that the VA, IPS or FFS mixtures according to the invention may also comprise compounds in which, for example, H, N, O, Cl and F are replaced by the corresponding isotopes.

[0458] The LC medium preferably has a nematic LC phase.

[0459] The LC medium may also contain one or more stabilizers, for example to prevent undesired spontaneous polymerization of the RM during storage or transport. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Commercially available stabilizers, such as those from the Irganox® series (Ciba), are particularly suitable, such as Irganox® 1076. When a stabilizer is used, the proportion of the stabilizer based on the RM or polymerizable component (component A) is preferably 10 to 50,000 ppm, particularly preferably 50 to 5,000 ppm.

[0460] In a preferred embodiment the LC medium comprises one or more chiral dopants, preferably in a concentration of 0.01 to 1% by weight, very preferably 0.05 to 0.5% by weight. The chiral dopants are preferably selected from the group consisting of the compounds from Table C below, very preferably from the group consisting of R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011 and R- or S-5011.

[0461] In another preferred embodiment the LC medium comprises a racemate of one or more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph.

[0462] In another preferred embodiment of the invention the LC medium comprises one or more further stabilizers.

[0463] Preferred stabilizers are selected from compounds of formula H:

[0464] [ka]

[0465] During the ceremony, Ar represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms, preferably 6 to 30 C atoms; Sp represents a spacer group; R S represents H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; Z S are -O-, -C(O)O-, and -(CH2) z -or-(CH2) z O-, or a single bond; HA is [ka] represents; R H H, O · , CH3, OH or ORS , preferably H or O · represents; R S1 , R S2 , R S3 and R S4 are identical or different and represent alkyl having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH3; G is H or R S or group Z S - represents HA; z is an integer from 1 to 6; and q is 3 or 4.

[0466] Compounds of formula H are described in EP-A-3354710 and EP-A-3354709.

[0467] Preferred compounds of formula H are selected from formulae H-1, H-2 and H-3.

[0468] [ka]

[0469] [ka]

[0470] During the ceremony, R H has the meaning given above and is preferably H or O · represents; n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7; and Sp represents a spacer group, preferably alkylene having 1 to 12 C atoms in which one or more non-adjacent -CH2- groups may be replaced by -O-.

[0471] A preferred compound of formula H-1 is of formula H-1-1:

[0472] [ka]

[0473] In the formula, R H has the meaning given above, preferably H or O · and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, and most preferably 7.

[0474] Highly preferred compounds of formula H-1-1 are those of formula H-1-1-1:

[0475] [ka]

[0476] Preferred compounds of formula H-2 are those of formula H-2-1:

[0477] [ka]

[0478] In the formula, R H has the meaning given above, preferably H or O · and n2 are the same or different in each occurrence, preferably the same and are an integer from 0 to 12, preferably 2, 3, 4, 5 or 6, very preferably 3; and R S are identical or different at each occurrence, preferably identical and denote alkyl having 1 to 6 C atoms, preferably n-butyl.

[0479] Highly preferred compounds of formula H-2-1 are those of formula H-2-1-1:

[0480] [ka]

[0481] Preferred compounds of formula H-3 are selected from formula H-3-1:

[0482] [ka]

[0483] In the formula, Sp and R H has the meaning given above and R H is preferably H or O · where n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, and most preferably 7.

[0484] More preferred stabilizers are selected from the group consisting of formulae ST-1 to ST-18.

[0485] [ka]

[0486] [ka]

[0487] [ka]

[0488] [ka]

[0489] During the ceremony R ST represents H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that in addition, one or more CH groups are present so that the O atoms are not directly linked to each other, such as -C≡C-, -CF2O-, -OCF2-, -CH=CH-, [ka] may be replaced independently by -O-, -CO-O-, or -O-CO-, in which one or more H atoms may additionally be replaced by halogen; [ka] may be the same or different in each occurrence, [ka] represents Z ST each independently represent -CO-O-, -O-CO-, -CF2O-, -OCF2-, -C2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-, -C2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond; L 1 and L 2 each independently represents F, Cl, CH3, CF3 or CHF2, p represents 0, 1 or 2; q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0490] Preferred compounds of formula ST are those of formula ST-1, ST-3, ST-8, ST-9, ST-12, ST-16, ST-17 and ST-18 and especially those selected from below:

[0491] [ka]

[0492] [ka]

[0493] [ka]

[0494] [ka]

[0495] In the compounds of formula ST-2a, n preferably represents 7.

[0496] Highly preferred stabilizers are selected from the group of compounds of formula ST-2a-1, ST-3a-1, ST-3a-2, ST-3b-1, ST-3b-2, ST-3c-1, ST-7, ST-8-1, ST-9-1 and ST-12.

[0497] [ka]

[0498] [ka]

[0499] In another preferred embodiment the LC medium comprises one or more stabilizers selected from Table D below.

[0500] The proportion of stabilizer in the LC medium is preferably between 10 and 500 ppm, very preferably between 20 and 100 ppm.

[0501] The LC media according to the present invention may additionally comprise one or more further components or additives, which are preferably selected, but not limited to, from the following list: comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobizing agents, adhesives, flow improvers, antifoaming agents, degassing agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0502] Furthermore, the LC medium can contain, for example, 0 to 15% by weight of pleochroic dyes, nanoparticles, conductive salts, preferably ethyl dimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium tetraphenylborate, or crown ether complex salts (e.g., Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), substances that improve the electrical conductivity, or substances that modify the dielectric anisotropy, viscosity, or alignment of the nematic phase. Substances of this type are described, for example, in German Patent Applications DE 22 09 127, DE 22 40 864, DE 23 21 632, DE 23 38 281, DE 24 50 088, DE 26 37 430, and DE 28 53 728.

[0503] The individual components of the preferred embodiments of the LC media according to the present invention listed above are either known or can be easily derived by those skilled in the art from the prior art, since their preparation methods are based on standard methods described in the literature.The corresponding compounds of formula CY are described, for example, in EP-A-0 364 538.The corresponding compounds of formula IV are described, for example, in DE-A-26 36 684 and DE-A-33 21 373.

[0504] The LC media that can be used according to the present invention can be prepared in a conventional manner, for example by mixing one or more of the above-mentioned compounds with one or more polymerizable compounds as defined above, and optionally with further liquid crystal compounds and / or additives. Generally, the desired amount of the component used in the smaller amount is dissolved in the component that constitutes the main component, advantageously at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, such as acetone, chloroform or methanol, and, after thorough mixing, remove the solvent again, for example by distillation. The present invention also relates to a method for preparing the LC media according to the present invention.

[0505] It goes without saying for those skilled in the art that the LC media according to the invention may also include compounds in which, for example, H, N, O, Cl, F are replaced by the corresponding isotopes, such as deuterium.

[0506] The following examples illustrate the present invention without limiting it. However, they provide those skilled in the art with preferred mixing ideas, along with the compounds preferably used, their respective concentrations and their combinations with one another. In addition, the examples illustrate what properties and property combinations are available.

[0507] In the present invention and in the following examples, the structures of liquid crystal compounds are represented by acronyms. Unless otherwise specified, the conversion to chemical formulas is carried out according to the following Tables A.1 to A.3. n H 2n+1 , C m H 2m+1 and C l H 2l+1 or C n H 2n , C m H 2m and C l H 2l are linear alkyl or alkylene groups with n, m and l C atoms in each case. Preferably, n, m and l are each, independently of one another, 1, 2, 3, 4, 5, 6 or 7. Table A.1 shows the codes for the ring elements of the nucleus of the compounds, Table A.2 lists the bridging units, and Table A.3 lists the meaning of the symbols for the left- and right-most groups of the molecules. The acronyms consist of the code for the ring element with an optional linking group followed by the first hyphen and the code for the left-most group, and the second hyphen and the code for the right-most group.

[0508] <Table A.1: Ring elements>

[0509] [Table 1]

[0510] [Table 2]

[0511] [Table 3]

[0512] <Table A.2: Cross-linking units>

[0513] [Table 4]

[0514] <Table A.3: Terminal group>

[0515] [Table 5]

[0516] [Table 6]

[0517] In the table, n and m are each integers, and the three dots "..." are places for other abbreviations from this table.

[0518] Table B shows exemplary structures of compounds, along with their respective abbreviations, that are preferred co-compounds according to the claimed blend concepts of the present invention.

[0519] In Table B, n, m, k, and l are each independently an integer, preferably 1 to 9, preferably 1 to 7, and k and l may 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-", n is preferably 1, 2, 3, or 4, very preferably 2 or 4. m is preferably 1, 2, 3, 4, or 5. In the combination "-Om", m is preferably 1, 2, 3, or 4, more preferably 2 or 4. The combination "-nVm" is preferably "2V1". (O)C m H 2m+1 is C m H 2m+1 or O.C. m H 2m+1 means.

[0520] [Table 7]

[0521] [Table 8]

[0522] [Table 9]

[0523] [Table 10]

[0524] [Table 11]

[0525] [Table 12]

[0526] [Table 13]

[0527]

Table 14

[0528]

Table 15

[0529] Table 16

[0530]

Table 17

[0531]

Table 18

[0532] Table 19

[0533] Table 20

[0534] Table 21

[0535] Table 22

[0536] Table 23

[0537] [Table 24]

[0538] [Table 25]

[0539] [Table 26]

[0540] [Table 27]

[0541] [Table 28]

[0542] [Table 29]

[0543] [Table 30]

[0544] [Table 31]

[0545] [Table 32]

[0546] In a preferred embodiment of the invention, the LC medium according to the invention comprises one or more compounds selected from the group consisting of the compounds from Table B.

[0547] Table C shows possible chiral dopants which can be added to the LC media according to the invention.

[0548] [Table 33]

[0549] [Table 34]

[0550] The LC media preferably comprise 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, of dopants. The LC media preferably comprise one or more dopants selected from the group consisting of the compounds from Table C.

[0551] Table D shows possible stabilizers which can be added to the LC media according to the invention, where n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and terminal methyl groups are not shown.

[0552] [Table 35]

[0553] [Table 36]

[0554] [Table 37]

[0555] [Table 38]

[0556] [Table 39]

[0557] [Table 40]

[0558] [Table 41]

[0559] [Table 42]

[0560] The LC medium preferably comprises 0 to 10% by weight, particularly preferably 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight, of stabilizers. The LC medium preferably comprises one or more stabilizers selected from the group consisting of the compounds from Table D.

[0561] Table E shows exemplary reactive mesogenic compounds that can be used in the LC media according to the present invention.

[0562] [Table 43]

[0563] [Table 44]

[0564] [Table 45]

[0565] [Table 46]

[0566] [Table 47]

[0567] Table 48

[0568] Table 49

[0569]

Table 50

[0570] Table 51

[0571] Table 52

[0572] Table 53

[0573] Table 54

[0574] Table 55

[0575] Table 56

[0576] Table 57

[0577] [Table 58]

[0578] [Table 59]

[0579] [Table 60]

[0580] [Table 61]

[0581] [Table 62]

[0582] [Table 63]

[0583] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from the polymerizable compounds of the formulae RM-1 to RM-182. Among these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-58, RM-64, RM-74, RM-76, RM-88, RM-91, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM-145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170, and RM-171 to RM-183 are particularly preferred. [Example]

[0584] The following examples illustrate the present invention without limiting it. However, they provide those skilled in the art with preferred mixing ideas, along with the compounds preferably used, their respective concentrations and their combinations with one another. In addition, the examples illustrate what properties and property combinations are available.

[0585] In addition, the following abbreviations and symbols are used: V0 is the capacitance threshold voltage [V] at 20°C, n e is the extraordinary refractive index at 20°C and 589 nm, n0 is the ordinary refractive index at 20°C and 589 nm, Δn is the optical anisotropy at 20°C and 589 nm; ε ⊥ is the dielectric constant perpendicular to the director at 20°C and 1 kHz, ε ∥ is the dielectric constant parallel to the director at 20°C and 1 kHz, Δε is the dielectric anisotropy at 20 °C and 1 kHz, cl.p., T(N,I) is the clearing point [°C], γ1 is the rotational viscosity at 20°C [mPa·s], K1 is the elastic constant for "splay" deformation at 20°C [pN], K2 is the elastic constant for "twist" deformation at 20°C [pN], K3 is the elastic constant for "bend" deformation at 20°C [pN], K avg is the average elastic constant [pN] at 20°C, and in this specification

number

[0586] Unless otherwise specified, all concentrations in this application are given in weight percent and refer to the corresponding total mixture, including all solid or liquid crystal components, excluding solvent.

[0587] Unless otherwise specified, all temperature values given in this application, such as the melting point T(C,N), the smectic (S) to nematic (N) phase transition T(S,N), and the clearing point T(N,I), are given in degrees Celsius (°C). Mp denotes the melting point, cl.p. the clearing point. Furthermore, C is the crystalline state, N is the nematic phase, S is the smectic phase, and I is the isotropic phase. The data between these symbols represent the transition temperatures.

[0588] All physical properties are or have been determined in accordance with "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck KGaA, Germany, and unless otherwise stated in each case, a temperature of 20°C applies, Δn is determined at 589 nm and Δε is determined at 1 kHz.

[0589] For the present invention, the term "threshold voltage" refers to the capacitive threshold (V), also known as the Freederickss threshold, unless otherwise specified. Also, in the examples, and as is generally usual, the threshold voltage is referred to as the 10% relative contrast (V 10 ) may also be given as the optical threshold.

[0590] Unless otherwise specified, the process of polymerizing the polymerizable compounds in the PSA displays, as described above and below, is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably at room temperature.

[0591] Unless otherwise specified, the methods for preparing the test cells and measuring their electro-optical and other properties are as or similar to those described hereinafter.

[0592] Unless otherwise specified, a PSVA display or PSVA test cell used for tilt angle measurements typically consists of two flat, parallel glass outer plates separated by approximately 4 μm, each with an electrode layer on its inner side and a polyimide alignment layer on top, except that the two polyimide layers are rubbed antiparallel to each other to produce homeotropic edge alignment of the liquid crystal molecules. PSVA displays or test cells have the same structure but omit one or both polyimide layers.

[0593] The polymerizable compound is typically polymerized in the display or test cell by irradiation with UV light of a defined intensity for a defined time while simultaneously applying a voltage to the display (typically 10V-30V AC, 1 kHz).

[0594] Tilt angles are typically determined using a Mueller matrix polarimeter "AxoScan" manufactured by Axometrics, Inc. Herein, low values (i.e., large deviations from a 90° angle) correspond to large tilts.

[0595] Unless otherwise specified, the term "tilt angle" refers to the angle between the LC director and the substrate, and "LC director" refers to the preferred orientation direction of the principal optical axes of the LC molecules in a layer of uniformly aligned LC molecules, which in the case of calamitic, uniaxial, positively birefringent LC molecules corresponds to their molecular long axis.

[0596] <Example 1> The nematic LC mixture N1 is formulated as follows:

[0597] [Table 64]

[0598] To the mixture N1 150 ppm of stabilizer ST-3a-1 is added.

[0599] [ka]

[0600] <Example 2> The nematic LC mixture N2 is formulated as follows:

[0601] [Table 65]

[0602] To the mixture N2 is added 100 ppm of stabilizer H-1-1-1.

[0603] [ka]

[0604] <Example 3> The nematic LC mixture N3 is formulated as follows:

[0605] [Table 66]

[0606] To mixture N3 is added 100 ppm of stabilizer ST-3b-1 and 50 ppm of stabilizer ST-3a-1.

[0607] [ka]

[0608] <Example 4> The nematic LC mixture N4 is formulated as follows:

[0609] [Table 67]

[0610] To mixture N4 is added 500 ppm of stabilizer H-2-1-1 and 50 ppm of stabilizer ST-3a-1.

[0611] [ka]

[0612] <Example 5> The nematic LC mixture N5 is formulated as follows:

[0613] [Table 68]

[0614] To mixture N5 is added 100 ppm of stabilizer ST-8-1 and 50 ppm of stabilizer ST-3a-1.

[0615] [ka]

[0616] <Example 6> The nematic LC mixture N6 is formulated as follows:

[0617] [Table 69]

[0618] To mixture N6 is added 50 ppm of stabilizer ST-9-1 and 50 ppm of stabilizer ST-3a-1.

[0619] [ka]

[0620] <Example 7> The nematic LC mixture N7 is formulated as follows:

[0621] [Table 70]

[0622] To mixture N7 is added 50 ppm of stabilizer ST-12 and 50 ppm of stabilizer ST-3a-1.

[0623] [ka]

[0624] <Example 8> The nematic LC mixture N8 is formulated as follows:

[0625] [Table 71]

[0626] To mixture N8 is added 150 ppm of stabilizer ST-3a-2.

[0627] [ka]

[0628] <Example 9> The nematic LC mixture N9 is formulated as follows:

[0629] [Table 72]

[0630] To mixture N9 is added 100 ppm of stabilizer ST-3b-2 and 50 ppm of stabilizer ST-3a-1.

[0631] [ka]

[0632] <Example 10> The nematic LC mixture N10 is formulated as follows:

[0633] [Table 73]

[0634] To the mixture N10, 100 ppm of stabilizer ST-7 and 50 ppm of stabilizer ST-3a-2 are added.

[0635] [ka]

[0636] <Example 11> The nematic LC mixture N11 is formulated as follows:

[0637] [Table 74]

[0638] To mixture N11 is added 100 ppm of stabilizer H-1-1-1 and 50 ppm of stabilizer ST-3a-2.

[0639] <Example 12> The nematic LC mixture N12 is formulated as follows:

[0640] [Table 75]

[0641] To mixture N12 is added 150 ppm of stabilizer ST-3a-1.

[0642] <Example 13> The nematic LC mixture N13 is formulated as follows:

[0643] [Table 76]

[0644] To mixture N13 is added 100 ppm of stabilizer ST-3b-1 and 50 ppm of stabilizer ST-3a-2.

[0645] <Example 14> The nematic LC mixture N14 is formulated as follows:

[0646] [Table 77]

[0647] To mixture N14 is added 50 ppm of stabilizer H-2-1-1 and 50 ppm of stabilizer ST-3a-1.

[0648] <Example 15> The nematic LC mixture N15 is formulated as follows:

[0649] [Table 78]

[0650] To mixture N15 is added 100 ppm of stabilizer ST-8-1 and 50 ppm of stabilizer ST-3a-2.

[0651] <Example 16> The nematic LC mixture N16 is formulated as follows:

[0652] [Table 79]

[0653] To mixture N16 is added 50 ppm of stabilizer ST-9-1 and 50 ppm of stabilizer ST-3a-1.

[0654] <Example 17> The nematic LC mixture N17 is formulated as follows:

[0655] [Table 80]

[0656] To mixture N17 is added 50 ppm of stabilizer ST-12.

[0657] <Example 18> The nematic LC mixture N18 is formulated as follows:

[0658] [Table 81]

[0659] To mixture N18 is added 150 ppm of stabilizer ST-3a-2.

[0660] <Example 19> The nematic LC mixture N19 is formulated as follows:

[0661] [Table 82]

[0662] To mixture N19 is added 150 ppm of stabilizer ST-3b-2.

[0663] <Example 20> The nematic LC mixture N20 is formulated as follows:

[0664] [Table 83]

[0665] To the mixture N20, 50 ppm of stabilizer ST-7 is added.

[0666] <Example 21> The nematic LC mixture N21 is formulated as follows:

[0667] [Table 84]

[0668] However, B(S)-4O-O1(c5) is [ka] is.

[0669] To mixture N21 is added 100 ppm of stabilizer H-1-1-1.

[0670] <Example 22> The nematic LC mixture N22 is formulated as follows:

[0671] [Table 85]

[0672] However, B(S)-1V1O-O1(c5) is [ka] is.

[0673] To mixture N22 is added 150 ppm of stabilizer ST-3a-1.

[0674] <Example 23> The nematic LC mixture N23 is formulated as follows:

[0675] [Table 86]

[0676] However, the CCP-1V2-1 [ka] is.

[0677] To mixture N23 is added 150 ppm of stabilizer ST-3b-1.

[0678] <Example 24> The nematic LC mixture N24 is formulated as follows:

[0679] [Table 87]

[0680] To the mixture N24 is added 50 ppm of stabilizer H-2-1-1.

[0681] <Example 25> The nematic LC mixture N25 is formulated as follows:

[0682] [Table 88]

[0683] To the mixture N25 is added 100 ppm of stabilizer ST-8-1.

[0684] <Example 26> The nematic LC mixture N26 is formulated as follows:

[0685] [Table 89]

[0686] To mixture N26 is added 50 ppm of stabilizer ST-9-1.

[0687] <Example 27> The nematic LC mixture N27 is formulated as follows:

[0688] [Table 90]

[0689] However, PYP-2-(c5) [ka] is.

[0690] To mixture N27 is added 50 ppm of stabilizer ST-12.

[0691] <Example 28> The nematic LC mixture N28 is formulated as follows:

[0692] [Table 91]

[0693] However, PYP-2-1(c3) [ka] is.

[0694] To mixture N28 is added 150 ppm of stabilizer ST-3a-2.

[0695] <Example 29> The nematic LC mixture N29 is formulated as follows:

[0696] [Table 92]

[0697] To mixture N29 is added 150 ppm of stabilizer ST-3b-2.

[0698] <Example 30> The nematic LC mixture N30 is formulated as follows:

[0699] [Table 93]

[0700] To the mixture N30, 100 ppm of stabilizer ST-7 is added.

[0701] <Example 31> The nematic LC mixture N31 is formulated as follows:

[0702] [Table 94]

[0703] To mixture N31 is added 100 ppm of stabilizer H-1-1-1.

[0704] <Example 32> The nematic LC mixture N32 is formulated as follows:

[0705] [Table 95]

[0706] To mixture N32 is added 150 ppm of stabilizer ST-3a-1.

[0707] <Example 33> The nematic LC mixture N33 is formulated as follows:

[0708] [Table 96]

[0709] To mixture N33 is added 150 ppm of stabilizer ST-3b-1.

[0710] <Example 34> The nematic LC mixture N34 is formulated as follows:

[0711] [Table 97]

[0712] To mixture N34 is added 50 ppm of stabilizer H-2-1-1.

[0713] <Example 35> 0.3% of polymerizable compound RM-171 is added to the mixture of Example 1 to prepare a polymerizable mixture.

[0714] [ka]

[0715] <Example 36> 0.3% of polymerizable compound RM-1 is added to the mixture of Example 2 to prepare a polymerizable mixture.

[0716] [ka]

[0717] <Example 37> 0.3% of polymerizable compound RM-35 is added to the mixture of Example 3 to prepare a polymerizable mixture.

[0718] [ka]

[0719] <Example 38> 0.3% of polymerizable compound RM-172 is added to the mixture of Example 4 to prepare a polymerizable mixture.

[0720] [ka]

[0721] <Example 39> 0.4% of polymerizable compound RM-64 is added to the mixture of Example 5 to prepare a polymerizable mixture.

[0722] [ka]

[0723] <Example 40> 0.3% of polymerizable compound RM-184 is added to the mixture of Example 6 to prepare a polymerizable mixture.

[0724] [ka]

[0725] <Example 41> The nematic LC mixture N41 is formulated as follows:

[0726] [Table 98]

[0727] However, LY-(c5)-O2 is [ka] is.

[0728] To mixture N41 is added 100 ppm of stabilizer H-1-1-1 and 50 ppm of stabilizer ST-3a-2.

[0729] <Example 42> The nematic LC mixture N42 is formulated as follows:

[0730] [Table 99]

[0731] However, CCOY-3-O(c5) is [ka] is.

[0732] To mixture N42 150 ppm of stabilizer ST-3a-1 is added.

[0733] <Example 43> The nematic LC mixture N43 is formulated as follows:

[0734] [Table 100]

[0735] However, CCOY-3-O(c4) is [ka] is.

[0736] To mixture N43 150 ppm of stabilizer ST-3b-1 is added.

[0737] <Example 44> The nematic LC mixture N44 is formulated as follows:

[0738] [Table 101]

[0739] However, CCOY-3-O(c3) is [ka] is.

[0740] To mixture N44 is added 50 ppm of stabilizer H-2-1-1.

[0741] <Example 45> The nematic LC mixture N45 is formulated as follows:

[0742] [Table 102]

[0743] However, CCOY-3-O1(c5) [ka] is.

[0744] To the mixture N45 100 ppm of stabilizer ST-8-1 is added.

[0745] <Example 46> The nematic LC mixture N46 is formulated as follows:

[0746] [Table 103]

[0747] However, CCOY-3-O1(c4) [ka] is.

[0748] To mixture N46 is added 50 ppm of stabilizer ST-9-1.

[0749] <Example 47> The nematic LC mixture N47 is formulated as follows:

[0750] [Table 104]

[0751] However, CCOY-3-O1(c3) [ka] is.

[0752] To the mixture N47, 50 ppm of stabilizer ST-12 is added.

[0753] <Example 48> The nematic LC mixture N48 is formulated as follows:

[0754] [Table 105]

[0755] However, CLY-(c5)-O2 is [ka] is.

[0756] To mixture N48 is added 150 ppm of stabilizer ST-3a-2.

[0757] <Example 49> The nematic LC mixture N49 is formulated as follows:

[0758] [Table 106]

[0759] However, PUS-3-(c5) [ka] is.

[0760] To mixture N49 is added 150 ppm of stabilizer ST-3b-2.

[0761] <Example 50> The nematic LC mixture N50 is formulated as follows:

[0762] [Table 107]

[0763] However, PUS-3-1(c5) [ka] is.

[0764] To the mixture N50, 100 ppm of stabilizer ST-7 is added.

[0765] <Example 51> The nematic LC mixture N51 is formulated as follows:

[0766] [Table 108]

[0767] However, PUS-3-2(c5) [ka] is.

[0768] To mixture N51 is added 100 ppm of stabilizer H-1-1-1 and 50 ppm of stabilizer ST-3a-2.

[0769] <Example 52> The nematic LC mixture N52 is formulated as follows:

[0770] [Table 109]

[0771] However, PUS-3-O(c5) [ka] is.

[0772] To mixture N52 is added 150 ppm of stabilizer ST-3a-1.

[0773] <Example 53> The nematic LC mixture N53 is formulated as follows:

[0774] [Table 110]

[0775] However, PUS-3-O1(c5) [ka] is.

[0776] To mixture N53 is added 150 ppm of stabilizer ST-3b-1.

[0777] <Example 54> The nematic LC mixture N54 is formulated as follows:

[0778] [Table 111]

[0779] However, LOY-3-O2 is [ka] is.

[0780] To the mixture N54 is added 50 ppm of stabilizer H-2-1-1.

[0781] <Example 55> The nematic LC mixture N55 is formulated as follows:

[0782] [Table 112]

[0783] However, YG-2O-O4 is [ka] is.

[0784] To the mixture N55 is added 100 ppm of stabilizer ST-8-1.

[0785] <Example 56> The nematic LC mixture N56 is formulated as follows:

[0786] [Table 113]

[0787] However, YG-4O-O4 is [ka] is.

[0788] To mixture N56 is added 50 ppm of stabilizer ST-9-1.

Claims

1. Liquid-crystalline medium comprising one or more compounds selected from the group of the compounds of the formula III and / or the formula IIIA and / or the formula BC and / or the formula PH-1 and one or more compounds of the formula I 【Chemical 1】 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 (In the formula, R １１ , R １２ , R ３１ , R ３２ , R ８１ and R ８２ each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that one or more —CH ２ The - group is formed so that the O atoms are not directly connected to each other. 【Chemistry 6】 -C≡C-, -CF ２ O-, -OCF ２ each independently being replaced by -, -CH=CH-, -O-, -CO-O- or -O-CO-, in which one or more H atoms may be replaced by halogen; X represents S or O; A ３ occur independently of each other, a) a 1,4-cyclohexenylene or 1,4-cyclohexylene group, in which one or two non-adjacent CH ２ The group may be replaced by —O— or —S—; b) a 1,4-phenylene group, in which one or two CH groups may be replaced by N, or c) a group selected from the group consisting of spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, and fluorene-2,7-diyl. represents provided that groups a), b) and c) may be mono- or polysubstituted by halogen atoms; n represents 0, 1 or 2; Z ３ are each independently, at each occurrence, —CO—O—, —O—CO—, —CF ２ O-, -OCF ２ -, -CH ２ O-, -OCH ２ -, -CH ２ -, -CH ２ CH ２ -, -(CH ２ ) ４ -, -CH=CH-CH ２ O-, -C ２ F ４ -, -CH ２ CF ２ -, -CF ２ CH ２ represents -, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond, L １１ , L １２ , L ３１ and L ３２ are each independently F, Cl, CF ３ or CHF ２ represents, and Y １ , Y ２ , Y ３ , Y ４ are each independently H, F, Cl, CF ３ , CHF ２ , C.H. ３ or OCH ３ Represents.)

2. 2. Liquid-crystalline medium according to claim 1, wherein the medium comprises one or more compounds selected from the compounds of the formulae III-1, III-6 and / or IIIA-1 【Chemistry 7】 【Chemistry 8】 【Chemistry 9】 wherein the occurring groups have the same meanings as given in Formula III and Formula IIIA.

3. 3. Liquid-crystalline medium according to claim 1, wherein the medium comprises one or more compounds selected from the group of the formulae IIA, IIB, IIC, IID, IIE and IIF 【Chemistry 10】 wherein the individual radicals, which are identical or different at each occurrence, each have the following meaning independently of one another: R ２１ and R ２２ is H, an alkyl, alkoxy or alkenyl group having up to 15 C atoms, the group being unsubstituted or F, Cl, CN or CF ３ and in addition, one or more CH ２ The group is -O-, -S-, -C≡C-, -CF so that O and / or S atoms are not directly linked to each other. ２ O-, -OCF ２ -, -CO-O-, -O-CO-, 【Chemistry 11】 may be replaced by L １ ~L ４ are F, Cl, CF ３ or CHF ２ and Y is H, F, Cl, CF ３ , CHF ２ or CH ３ and Z ２ , Z ２ is a single bond, -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ -, -CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ -, -CF=CF-, -CH=CHCH ２ O-, p is 0, 1 or 2, and q is 0 or 1.

4. Liquid-crystalline medium according to any one of claims 1 to 3, wherein the medium comprises one or more compounds of the formula IV 【Chemistry 12】 (In the formula, R ４１ represents an unsubstituted alkyl group having 1 to 7 C atoms, a cyclic alkyl group having 3 to 6 C atoms, or an unsubstituted alkenyl group having 2 to 7 C atoms, and R ４２ represents an unsubstituted alkyl group having 1 to 7 C atoms, a cyclic alkyl group having 3 to 6 C atoms, an unsubstituted alkoxy group having 1 to 6 C atoms, or an unsubstituted alkenyl group having 2 to 7 C atoms.

5. 5. Liquid-crystalline medium according to claim 4, wherein the medium comprises one or more compounds of the formulae IV-1 and IV-3. 【Chemistry 13】 (In the formula, alkyl and alkyl ＊ represent independently of one another an alkyl group having 1 to 7 C atoms or a cyclic alkyl group having 3 to 6 C atoms, and alkenyl represents an alkenyl group having 2 to 7 C atoms.

6. 5. Liquid-crystalline medium according to claim 4, wherein the medium comprises one or more compounds of the formula IVa-2 【Chemistry 14】 (In the formula, alkyl and alkyl ＊ represent independently a linear alkyl group having 1 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms.

7. Liquid-crystalline medium according to any one of claims 1 to 6, wherein the medium comprises one or more compounds of the formula V 【Chemistry 15】 (In the formula, R ５１ , R ５２ represents alkyl having 1 to 7 C atoms or cyclic alkyl having 3 to 6 C atoms, alkoxy having 1 to 7 C atoms or alkoxyalkyl having 2 to 7 C atoms, alkenyl or alkenyloxy, 【Chemistry 16】 represents Z ５１ , Z ５２ are each independently —CH ２ -CH ２ -, -CH ２ represents —O—, —CH═CH—, —C≡C—, —COO— or a single bond, and n is 1 or 2; provided that one or more compounds of formula V are different from formula I.

8. Liquid-crystalline medium according to any one of claims 1 to 7, wherein the medium comprises one or more compounds of the formulae VI-1 to VI-22.

9. Liquid-crystalline medium according to any one of claims 1 to 8, wherein the medium comprises one or more compounds of the formulae VII-1 to VII-9

10. Liquid-crystalline medium according to any one of claims 1 to 9, wherein the medium comprises one or more compounds of the formulae CR and PH-2.

11. 11. The liquid-crystalline medium according to claim 1, further comprising one or more additives selected from the group consisting of stabilizers, chiral dopants, polymerization initiators and self-aligning additives.

12. Liquid crystal display comprising a liquid crystal medium according to any one of claims 1 to 11.

13. The display may be VA, PS-VA, FFS, PS-FFS, UB-FFS, UBplus, IPS, PS-IPS or UV ２ 13. The liquid crystal display of claim 12, which is an A display.

14. Use of a liquid-crystalline medium according to any one of claims 1 to 11 for energy-saving LC displays.

15. 12. Process for preparing a liquid-crystalline medium according to any one of claims 1 to 11, comprising mixing one or more compounds of formula I with one or more compounds selected from the group of compounds of formula III and / or formula IIIA and / or formula BC and / or formula PH-1, and optionally further LC compounds and / or additives.

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