Liquid crystal medium

Abstract

The invention relates to a liquid crystal (LC) material as defined in claim 1, which has a negative dielectric anisotropy, and to the use thereof for optical, electro-optical and electronic purposes, for example in LC displays, in particular energy-saving displays based on the ECB, IPS or FFS effect.

Description

Field of the Invention

[0001] The present invention relates to liquid crystal (LC) dielectrics having negative dielectric anisotropy and their use for optical, electro-optical and electronic purposes, in particular in LC displays. Background of the Invention

[0002] One of the liquid crystal displays (LCDs) currently in use is the TN ("twisted nematic") mode. However, a disadvantage of TN LCDs is that the contrast is strongly dependent on the viewing angle.

[0003] Furthermore, so-called VA ("vertical alignment") displays with a wider viewing angle are known. The LC cell of a VA display contains a layer of LC dielectric between two transparent electrodes, where the LC dielectric typically has negative dielectric anisotropy. In the non-powered state, the molecules of the LC layer are aligned perpendicular to the electrode surfaces (vertically) or have an inclined vertical alignment. When a voltage is applied to the two electrodes, re-alignment of the LC molecules parallel to the electrode surfaces occurs.

[0004] Also known are so-called IPS ("in-plane switching") displays, which contain an LC layer between two substrates, where the two electrodes are arranged on only one of the two substrates and preferably have an intermeshing comb-like structure. When a voltage is applied to the electrodes, an electric field with a significant component parallel to the LC layer is generated therebetween. This causes re-alignment of the LC molecules within the layer plane.

[0005] Furthermore, so-called FFS ("fringe field switching") displays have been reported (see in particular S.H. Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, 1028), which contain two electrodes on the same substrate, one of which is structured in a comb-like manner and the other is unstructured. This results in a strong so-called "fringe field", i.e., a strong electric field close to the electrode edges, and such an electric field throughout the cell, which has both a strong vertical component and a strong horizontal component. FFS displays have a small contrast viewing angle dependence. FFS displays typically contain an LC dielectric with positive dielectric anisotropy and an alignment layer, typically an alignment layer of polyimide, which provides planar alignment of the molecules of the LC dielectric.

[0006] FFS displays can be operated as active matrix or passive matrix displays. In the case of an active matrix display, 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 a passive matrix display, individual pixels are typically addressed according to multiplexing methods known in the prior art.

[0007] In addition, FFS displays have been disclosed (see S.H. Lee et al., Appl. Phys. Lett. 73(20), 1998, 2882-2883 and S.H. Lee et al., Liquid Crystals 39(9), 2012, 1141-1148), which have an electrode design and layer thickness similar to those of FFS displays, but include a layer with an LC medium having negative dielectric anisotropy instead of a layer with an LC medium having positive dielectric anisotropy. Compared with an LC medium having positive dielectric anisotropy, an LC medium having negative dielectric anisotropy shows a more favorable director orientation, which has less tilt and more twist in orientation, and as a result, these displays have higher transmittance. The display also includes an alignment layer, preferably an alignment layer of polyimide provided on at least one substrate, which contacts the LC medium and induces planar alignment of the LC molecules of the LC medium. These displays are also referred to as "ultra-bright FFS (UB-FFS)" mode displays. These displays require an LC medium with high reliability.

[0008] In newer types of VA displays, the homogeneous alignment of LC molecules is limited to a plurality of relatively small domains within the LC cell. Disclinations, also called tilt domains, may exist between these domains. A VA display having tilt domains has a greater contrast and a viewing angle independence of grey shades compared with a conventional VA display. In addition, this type of display is easier to manufacture because no additional electrode surface treatment (such as by rubbing) for homogeneous alignment of molecules in the on state is required. Instead, the preferential direction of the tilt angle or pretilt angle is controlled by a special design of the electrodes.

[0009] In so-called MVA (“multi-domain vertical alignment”) displays, this is typically achieved by electrodes with protrusions that cause local pre-tilting. Thereby, when a voltage is applied, the LC molecules are aligned parallel to the electrode surface in different, defined cell regions in different directions. Thereby, “controlled” switching is achieved and the formation of disturbing disclination lines is prevented. Although this arrangement improves the viewing angle of the display, however, this results in a reduction in its light transmissivity. A further improvement of MVA uses protrusions only on one electrode side, while the opposite electrode has slits, which improves the light transmissivity. The slit electrode generates a non-uniform electric field in the LC cell when a voltage is applied, meaning that controlled switching is still achieved. To further improve the light transmissivity, the spacing between the slit and the protrusion can be increased, but this in turn results in an increase in the response time. In so-called PVA (“patterned VA”) displays, the protrusions are made completely redundant, since both electrodes are structured by slits on opposite sides, which results in increased contrast and improved light transmissivity, but this is technically difficult and makes the display more sensitive to mechanical influences (“tapping”, etc.). However, for many applications, such as monitors and especially TV screens, a shortening of the response time of the display as well as an improvement in the contrast and brightness (transmittance) of the display are required.

[0010] Another development is so-called PS (“polymer sustained”) or PSA (“polymer sustained alignment”) type displays, for which the term “polymer stabilization” is also occasionally used. In these, a small amount (e.g., 0.3 wt%, typically <1 wt%) of one or more polymerizable compounds, preferably polymerizable monomer compounds, is added to the LC medium, and after the LC medium is filled into the display, it is polymerized or crosslinked in situ (usually by UV photopolymerization), while optionally applying a voltage to the electrodes of the display. The polymerization is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, typically at room temperature. Adding a polymerizable mesogenic or liquid crystal compound (also called a reactive mesogen or “RM”) to the LC mixture has proven to be particularly suitable.

[0011] At the same time, the PS(A) principle is being used in various conventional LC display modes. Thus, for example, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, and PS-TN displays are known. The aggregation of the RM preferably occurs under the applied voltage in the case of PS-VA and PS-OCB displays and occurs with or without, preferably without, the applied voltage in the case of PS-IPS displays. As can be verified in a test cell, the PS(A) method results in a pretilt in the cell. In the case of PS-VA displays, this pretilt has a positive effect on the response time. For PS-VA displays, standard MVA or PVA pixel and electrode layouts can be used. However, additionally, for example, it is also possible to manage with only one structured electrode side without protrusions, which significantly simplifies production and at the same time results in very good contrast and very good transmittance.

[0012] PS-VA displays are described, for example, in EP1 170 626 A2, US 6,861,107, US 7,169,449, US2004 / 0191428 A1, US 2006 / 0066793 A1, and US 2006 / 0103804 A1.

[0013] Particularly for monitors and especially for TV applications, there is a continuous requirement for the optimization of the response time as well as the contrast and brightness (and thus also the transmittance) of LC displays. The PSA method can provide key advantages here. Particularly in the case of PS-VA, PS-IPS, and PS-FFS displays, a shortening of the response time related to the pretilt measurable in a test cell can be achieved without a significant detrimental effect on other parameters.

[0014] Another problem observed in the prior art is that the use of conventional LC media in LC displays (including but not limited to PS-type displays) often results in non-uniformities in the display, especially when the LC medium is filled in a display cell manufactured using the one drop filling (ODF) method. This phenomenon is also referred to as "ODF non-uniformity". Therefore, there is a need to provide an LC medium that reduces ODF non-uniformity.

[0015] Another problem observed in the prior art is that LC media used in PSA displays (including but not limited to PSA type displays) often exhibit high viscosities and, as a result, high switching times. To reduce the viscosity and switching time of the LC media, the addition of LC compounds having alkenyl groups has been proposed in the prior art. However, it has been observed that LC media containing alkenyl compounds often show reduced reliability and stability, as well as a reduction in VHR, especially after exposure to UV radiation. In particular, for use in PSA displays, this is a significant drawback since the photopolymerization of the RM in PSA displays is typically carried out by exposure to UV radiation, which can result in a decrease in VHR in the LC media.

[0016] Furthermore, there is a great need for PSA displays and LC media and polymerizable compounds for such PSA displays that can achieve high specific resistance over a large operating temperature range, short response times even at low temperatures, low threshold voltages, low pretilt angles, a large number of gray levels, high contrast, and wide viewing angles, as well as high reliability and high values of VHR after UV exposure, and in the case of the polymerizable compounds, low melting points and high solubility in the LC host mixture. In PSA displays for mobile applications, there is a particular need for available LC media that exhibit low threshold voltages and high birefringence.

[0017] One display trend is to achieve the fastest possible response times for optimal motion picture quality. In this regard, media having negative dielectric anisotropy have an inherent disadvantage compared to LC media having positive dielectric anisotropy. On the other hand, mixtures having negative dielectric anisotropy can achieve higher transmittance in a standard FFS cell layout, and thus their use has a positive impact on power consumption and the environment. There is a need in the art to achieve both fast response times and higher transmittance. Especially for mobile devices, there is a great demand for displays having high transmittance, which enables the use of a lower intensity backlight, and thus, this results in longer battery life and, therefore, a more sustainable product. Alternatively, displays having higher brightness can be achieved, especially with improved contrast in ambient light. In addition, the popularity of 8K and gaming monitors has led to an increased demand for LC display panels having higher refresh rates and, thus, an increased demand for LC media having faster response times.

[0018] Accordingly, there is still a great need for VA, FFS, or PSA displays and LC media optionally containing polymerizable compounds for VA, FFS, or PSA displays that do not exhibit the above-described defects, or only to a lesser extent, and have improved properties. SUMMARY OF THE INVENTION

[0019] The present invention is based on the following object: to provide novel suitable LC media which do not have the above-mentioned disadvantages or have these disadvantages to a reduced extent.

[0020] Surprisingly, it has now been found that liquid crystal media with a suitably high negative Δε, a suitable phase range, and Δn and a high LTS can be achieved by using a liquid crystal medium comprising a compound of formula I defined below and a compound of formula CPY, which do not exhibit the disadvantages of the materials of the prior art or at least exhibit these disadvantages to a significantly lesser extent.

[0021] The present invention relates to a liquid crystal medium comprising a compound of formula I

[0022]

[0023] and

[0024] a compound of formula CPY

[0025]

[0026] and one or more compounds selected from the group of compounds of formulae IIA, IIB, IIC and IID

[0027]

[0028] wherein

[0029] R 2A ,R 2B ,R 2C and R 2D are the same or different and represent H, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenoxy group having 2 to 15 C atoms or a branched alkyl, alkoxy, alkenyl, alkenoxy group each having 3 to 15 C atoms, where one or more CH2 groups in these groups may each independently of one another be -CH=CH-, -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not directly linked to one another, and where one or more H atoms may be replaced by halogen,

[0031] L 1 and L 2 each independently of one another represent F, Cl, CF3 or CHF2,

[0032] Y represents H, F, Cl, CF3, CHF2 or CH3, preferably H or CH3, more preferably H,

[0033] Z 2 ,Z 2Band Z 2D each independently of one another represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF- or -CH=CHCH2O-

[0034] (O) represents O or a single bond

[0035] p represents 0, 1 or 2

[0036] q represents 0 or 1, and

[0037] v represents an integer from 1 to 6

[0038] wherein the CPY compounds of the formula are excluded from the compounds of the formula IIB.

[0039] The invention also relates to an LC display comprising an LC medium according to the invention, in particular a VA, IPS, FFS or UB-FFS or PSA display, particularly preferably an FFS, UB-FFS, VA or PS-VA display.

[0040] The invention also relates to the use of an LC medium according to the invention in a PSA display, in particular in a PSA display containing an LC medium, for generating a tilt angle in the LC medium by in-situ polymerization of a polymerizable reactive mesogen (RM) in the PSA display (preferably in an electric or magnetic field).

[0041] The invention also relates to a method for preparing an LC medium as described above and below, comprising the step of mixing one or more compounds of the formula I with one or more compounds of the formula CPY, and with one or more compounds of the formulae IIA, IIB, IIC and / or IID, and optionally with one or more chiral dopants, and optionally with one or more polymerizable compounds, and optionally with further LC compounds and / or additives.

[0042] The invention also relates to the use of an LC medium according to the invention in a polymer-stabilized SA-VA display, and to a polymer-stabilized SA-VA display comprising an LC medium according to the invention.

[0043] According to a further aspect of the invention, there is provided an energy-saving display preferably for gaming, comprising a liquid crystal medium as defined above and below. In a preferred embodiment, the medium of the energy-saving display for gaming has a birefringence in the range from 0.125 to 0.155. The display according to the invention preferably has a cell gap of 3.3 μm or less, more preferably 2.2 μm or less.

[0044] The invention further relates to a method for manufacturing an LC display as described above, comprising the steps of filling or otherwise providing an LC medium between the substrates of the display, said LC medium optionally comprising one or more polymerizable compounds as described above, and optionally polymerizing said polymerizable compounds.

[0045] The LC media according to the invention exhibit the following advantageous properties, especially when used in FFS displays:

[0046] - Excellent low temperature stability (LTS)

[0047] - Improved contrast of the display,

[0048] - High transmittance of the display

[0049] - High clearing temperature,

[0050] - High voltage holding ratio,

[0051] - Low rotational viscosity

[0052] - Fast switching,

[0053] - Fast response time, enabling an LCD with low power consumption to extend the battery life of mobile devices,

[0054] - Sufficient heat and / or UV stability, especially when used outdoors.

[0055] - A suitably high birefringence in combination with a fast response time for gaming applications (especially in displays with a cell gap of 3.3 μm or less).

[0056] Preferred compounds of formulae IIA, IIB, IIC and IID are shown below:

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] wherein the parameter a represents 1 or 2, alkyl and alkyl* each independently of one another represent straight-chain alkyls having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond. 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-.

[0070] Very preferably, the compounds of formula IID are selected from the following sub-formulas:

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] In a preferred embodiment, the medium comprises one or more compounds of formula IID-10a

[0077]

[0078] wherein the groups and parameters occurring have the meanings given above under formula IID, and

[0079] R 2 represents where r is 0, 1, 2, 3, 4, 5 or 6 and s is 1, 2 or 3.

[0080] Preferred compounds of formula IID-10a are compounds IID-10a-1 to IID-10a-14.

[0081]

[0082]

[0083]

[0084] Particularly preferred mixtures according to the invention comprise one or more compounds of formulae IIA-2, IIA-8, IIA-10, IIA-16, IIA-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1, IID-4 and IID-10.

[0085] Preferred media according to the invention comprise at least one compound of formula IIC-1,

[0086]

[0087] wherein alkyl and alkyl* have the meanings given above.

[0088] In particular, the medium comprises one or more compounds of formula IIA-2 selected from the following sub-formulae:

[0089]

[0090]

[0091] Alternatively, preferably in addition to the compounds of formulae IIA-2-1 to IIA-2-5, the medium further comprises one or more compounds of formulae IIA-2a-1 to IIA-2a-5:

[0092]

[0093] In particular, the medium comprises one or more compounds of formula IIA-10 selected from the following sub-formulae:

[0094]

[0095]

[0096] Alternatively, preferably in addition to the compounds of formulae IIA-10-1 to IIA-10-5, the medium further comprises one or more compounds of formulae IIA-10a-1 to IIA-10a-5:

[0097]

[0098]

[0099] In particular, the medium comprises one or more compounds of formula IIB-10 selected from the following sub-formulae:

[0100]

[0101] Alternatively, preferably in addition to the compounds of formulae IIB-10-1 to IIB-10-5, the medium further comprises one or more compounds of formulae IIB-10a-1 to IIB-10a-5:

[0102]

[0103]

[0104] Alternatively, preferably in addition to the compound of formula IIC-1, the medium further comprises one or more compounds of formulae IIC-1a-1 and IIC-1a-2:

[0105]

[0106] wherein alkyl represents a straight-chain alkyl having 1 to 7 C atoms, preferably 2 to 5 C atoms, and very preferably represents ethyl.

[0107] The medium according to the invention preferably comprises one or more compounds of formula III

[0108]

[0109] wherein

[0110] R 31 and R 32 each independently of one another represent H, an alkyl or alkoxy group having 1 to 15 C atoms, where one or more CH2 groups in these groups are each independently of one another replaced by

[0111] -CH═CH-, -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another, and where one or more H atoms may be replaced by halogen,

[0112] A 31 each independently of one another in each occurrence represents

[0113] a) 1,4-cyclohexenylene or 1,4-cyclohexylene, where one or two non-adjacent CH2 groups may be replaced by -O- or -S-,

[0114] b) 1,4-phenylene, where one or two CH groups may be replaced by N, or

[0115] c) a group selected from spiro[3.3]heptane-2,6-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,

[0116] wherein the groups a), b) and c) may be mono- or poly-substituted by halogen atoms,

[0117] n represents 0, 1 or 2, preferably 0 or 1,

[0118] Z 31 each independently represents, at each occurrence, -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH═CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF═CF-, -CH═CF-, -CF═CH-, -CH═CH-, -C≡C- or a single bond, and

[0119] L 31 and L 32 each independently represents F, Cl, CF3 or CHF2, preferably H or F, most preferably F, and

[0120] W represents O or S.

[0121] The compound of formula III is preferably selected from the compounds of formula III-1 and / or III-2

[0122]

[0123] wherein the groups appearing have the same meanings as those given for formula III above, and preferably

[0124] R 31 and R 32 each independently is an alkyl, alkenyl or alkoxy group having at most 15 C atoms, more preferably one or both of them represent alkoxy groups, and

[0125] L 31 and L 32 each preferably represents F.

[0126] Preferably, the compound of formula III-1 is selected from the compounds of formula III-1-1 to III-1-11, preferably formula III-1-6

[0127]

[0128]

[0129] wherein

[0130] alkyl and alkyl* each independently of the other represent a straight-chain alkyl group having 1 to 6 C atoms, alkenyl and alkenyl* each independently of the other represent a straight-chain alkenyl group having 2 to 6 C atoms, alkoxy and alkoxy* each independently of the other represent a straight-chain alkoxy group having 1 to 6 C atoms, and L 31 and L 32 each independently of the other represent F or Cl, preferably both are F.

[0131] The compounds of formula III-2 are preferably selected from the compounds of formulae III-2-1 to III-2-10, preferably formula III-2-6,

[0132]

[0133]

[0134] wherein

[0135] alkyl and alkyl* each independently of the other represent a straight-chain alkyl group having 1 to 6 C atoms, alkenyl and alkenyl* each independently of the other represent a straight-chain alkenyl group having 2 to 6 C atoms, alkoxy and alkoxy* each independently of the other represent a straight-chain alkoxy group having 1 to 6 C atoms, and L 31 and L 32 each independently of the other represent F or Cl, preferably both are F.

[0136] Optionally, the medium comprises one or more compounds of formula IIIA-1 and / or IIIA-2

[0137]

[0138] wherein L 31 and L 32 have the same meanings as given under formula III, (O) represents O or a single bond,

[0139] R IIIA represents an alkyl or alkenyl group having at most 7 C atoms or the group Cy-C m H 2m+1 -,

[0140] 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,

[0141] Cy represents an alicyclic group having 3, 4 or 5 ring atoms, which is optionally substituted by: an alkyl or alkenyl each having at most 3 C atoms, or a halogen or CN, and preferably represents cyclopropyl, cyclobutyl, cyclopentyl, cyclopent-1-enyl, cyclopent-2-enyl and cyclopent-3-enyl.

[0142] The compounds of formulae IIIA-1 and / or IIIA-2 may alternatively or in addition to the compounds of formula III preferably additionally be included in the medium.

[0143] Very preferred compounds of formulae IIIA-1 and IIIA-2 are as follows:

[0144]

[0145]

[0146] where alkoxy represents a straight-chain alkoxy having 1-6 C atoms or alternatively is -(CH2) n F, where n is 2, 3, 4, or 5, preferably C2H4F.

[0147] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula III-3

[0148]

[0149] where

[0150] R 31 , R 32 are the same or different and represent H, an alkyl or alkoxy having 1 to 15 C atoms, where one or more CH2 groups in these groups are optionally replaced independently of one another by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another, and where, furthermore, one or more H atoms may be replaced by a halogen.

[0151] The compounds of formula III-3 are preferably selected from the compounds of formulae III-3-1 to III-3-10:

[0152]

[0153]

[0154] where R 32 represents an alkyl having 1 to 7 C atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl, or alternatively -(CH2)n F, where n is 2, 3, 4, or 5, preferably C2H4F.

[0155] In a preferred embodiment of the present invention, the medium comprises one or more compounds of formulae III-4 to III-6, preferably of formula III-5,

[0156]

[0157] where the parameters have the meanings given above, R 31 preferably represents a straight-chain alkyl group and R 32 preferably represents an alkoxy group, each having 1 to 7 C atoms.

[0158] In a preferred embodiment, the medium comprises one or more compounds of formula III selected from compounds of formulae III-7 to III-9, preferably of formula III-8,

[0159]

[0160] where the parameters have the meanings given above, R 31 preferably represents a straight-chain alkyl group and R 32 preferably represents an alkoxy group, each having 1 to 7 C atoms.

[0161] In a preferred embodiment, the medium comprises one or more compounds of formula IV,

[0162]

[0163] where

[0164] R 41 represents an alkyl group having 1 to 7 C atoms or an alkenyl group having 2 to 7 C atoms, preferably a normal alkyl group, particularly preferably having 2, 3, 4 or 5 C atoms, and

[0165] R 42 represents an alkyl group having 1 to 7 C atoms or an alkoxy group having 1 to 6 C atoms (both preferably having 2 to 5 C atoms), an alkenyl group having 2 to 7 C atoms, preferably having 2, 3 or 4 C atoms, more preferably vinyl or 1-propenyl, especially vinyl.

[0166] The compounds of formula IV are preferably selected from the compounds of formulae IV-1 to IV-4,

[0167]

[0168]

[0169] where

[0170] alkyl and alkyl’, independently of one another, represent an alkyl group having 1 to 7 C atoms, preferably having 1 to 5 C atoms,

[0171] alkenyl represents an alkenyl group having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably 2 C atoms,

[0172] alkenyl’ represents an alkenyl group having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms, and

[0173] alkoxy represents an alkoxy group having 1 to 5 C atoms, preferably having 2 to 4 C atoms.

[0174] The compounds of formula IV-1 are preferably selected from the compounds of formula IV-1-1 to IV-1-6:

[0175]

[0176] The compounds of formula IV-2 are preferably selected from the compounds of formula IV-2-1 and IV-2-2

[0177]

[0178] The compounds of formula IV-3 are preferably selected from the compounds of formula IV-3-1, IV-3-2 and IV-3-3

[0179]

[0180] wherein alkyl has the meaning defined above, and wherein the compound of formula I is excluded from formula IV-3-2.

[0181] The compounds of formula IV-3-1, IV-3-2 and IV-3-3 are preferably selected from the following compounds:

[0182]

[0183]

[0184] Very preferably, the medium according to the invention comprises a compound of formula IV-4, in particular selected from the compounds of formula IV-4-1 to IV-4-3

[0185]

[0186] The liquid crystal medium preferably further comprises one or more compounds of formula IVa,

[0187]

[0188] wherein

[0189] R 41 and R 42 each independently of one another represent a straight-chain alkyl, alkoxy, alkenyl, alkoxyalkyl or alkoxy having at most 12 C atoms, and represents

[0190] Z 4 represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8-, -CF=CF-.

[0191] Preferred compounds of formula IVa are as follows:

[0192]

[0193] wherein

[0194] alkyl and alkyl* each independently of one another represent a straight-chain alkyl having 1 to 6 C atoms.

[0195] The medium according to the invention preferably comprises at least one compound of formula IVa-1 and / or formula IVa-2.

[0196] The proportion of the compound of formula IVa in the entire mixture is preferably less than 5% by weight, very preferably less than 2% by weight.

[0197] Preferably, the medium comprises one or more compounds of formula IVb-1 to IVb-4, more preferably compounds of formula IVb-1 to IVb-3

[0198]

[0199]

[0200] wherein

[0201] alkyl and alkyl* each independently of one another represent a straight-chain alkyl having 1 to 6 C atoms, and

[0202] alkenyl and alkenyl* each independently of one another represent a straight-chain alkenyl having 2 to 6 C atoms.

[0203] Among the compounds of formula IVb-1 to IVb-3, the compound of formula IVb-2 is particularly preferred.

[0204] Particularly preferred biphenyls are

[0205]

[0206] wherein alkyl* represents an alkyl group having 1 to 6 C atoms and preferably represents n-propyl. The medium according to the invention particularly preferably comprises one or more compounds of formula IVb-1-1 and / or IVb-2-3.

[0207] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula V

[0208]

[0209] wherein

[0210] R 51 and R 52 each independently represent an alkyl group having 1 to 7 C atoms, an alkoxy group having 1 to 7 C atoms, or an alkoxyalkyl, alkenyl or alkenyloxy group having 2 to 7 C atoms, identically or differently represent

[0211] Z 51 and Z 52 each independently of one another represent -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO- or a single bond, and

[0212] n is 1 or 2,

[0213] wherein compounds of formula CL are excluded.

[0214] Compounds of formula V are preferably selected from compounds of formulae V-1, V-2 and V-3:

[0215]

[0216] wherein the groups occurring have the meanings given above for formula V.

[0217] Compounds of formula V-1 are preferably selected from compounds of formulae V-1-1 to V-1-8;

[0218] Compounds of formula V-2 are preferably selected from compounds of formulae V-2-1 to V-2-4; and

[0219] Compounds of formula V-3 are preferably selected from compounds of formulae V-3-1 to V-3-4:

[0220]

[0221] wherein R 51 and R 52 have the meanings shown in formula V above.

[0222] R 51 and R52 Preferably, each independently represents a straight-chain alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms.

[0223] Very preferably, the compound of formula V-2-1 is selected from the compounds of formulae V-2-1a to V-2-1g

[0224]

[0225] Very preferably, the compound of formula V-2-2 is selected from the compounds of formulae V-2-2a to V-2-2i

[0226]

[0227] Preferably, the medium according to the invention comprises one or more compounds of formula CL

[0228]

[0229] wherein

[0230] R L represents H, a straight-chain or branched-chain alkyl or alkoxy group having 1 to 15 carbon atoms, or a straight-chain or branched-chain alkenyl group having 2 to 15 carbon atoms, wherein one or more CH2 groups in these groups may each independently be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to each other, and wherein, furthermore, one or more H atoms may be replaced by halogen

[0231] X L represents F, Cl, CN, CHF2, CF3, OCF3, or, identically or differently, has one of the meanings of R L

[0232] Y L represents H, F, Cl or CH3.

[0233] The compounds of formula CL are preferably selected from the group of compounds of formulae CL-1, CL-2 and CL-3

[0234]

[0235] wherein

[0236] R L1 and R L2 ​, which are the same or different and have the meanings given above for formula I, and preferably each represents an alkyl or alkenyl group having 1 to 7 C atoms or 2 to 7 C atoms, respectively, where the CH2 groups may be replaced by cyclopropane-1,2-diyl, and R L2 Alternatively represents an alkoxy group having 1 to 5 C atoms.

[0237] Highly preferred compounds of formula CL are selected from the compounds of formula CL-3-1 to CL-3-12:

[0238]

[0239]

[0240] In a particularly preferred embodiment, the medium according to the invention comprises the compound CL-3-1 or CLP-3-3.

[0241] In a preferred embodiment of the invention, the medium further comprises one or more compounds of formula VI:

[0242]

[0243] wherein

[0244] R 61 and R 62 represent H, F, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenoxy group having 2 to 15 C atoms or a branched-chain alkyl, alkoxy, alkenyl, alkenoxy group each having 3 to 15 C atoms, where one or more of the CH2 groups in these groups may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another, and where one or more H atoms may be replaced by halogen,

[0245] X 61 , X 62 , X 63 , X 64 , X 65 , and X 66 , which are the same or different, represent H or F, preferably at least one of X 61 , X 62 , X 63 , X 64 , X 65 , and X 66 represents F, more preferably at least one of X 61 , X 62 , X 63 , X 64 , X65 , and X 66 at least two of which represent F;

[0246] Z 61 and Z 62 , the same or different, represent CH2CH2 or a single bond.

[0247] The compounds of formula VI are preferably selected from formulae VI-1 and VI-2:

[0248]

[0249] wherein the groups occurring have the meanings given for formula VI.

[0250] The compounds of formula VI-1 are preferably selected from formulae VI-1-1 to VI-1-21, very preferably formula VI-1-4:

[0251]

[0252]

[0253]

[0254] wherein R 6 represents a straight-chain alkyl or alkoxy group having 1 to 6 C atoms, (O) represents -O- or a single bond, and m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4.

[0255] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentyloxy.

[0256] In the compound of formula VI-1-4, (O) preferably represents -O-.

[0257] The compounds of formula VI-2 are preferably selected from formulae VI-2-1 to VI-2-15, very preferably formula VI-2-1:

[0258]

[0259]

[0260]

[0261] wherein R 6 represents a straight-chain alkyl or alkoxy group having 1 to 6 C atoms, (O) represents -O- or a single bond, and m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4.

[0262] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentyloxy.

[0263] In a preferred embodiment of the invention, the medium further comprises one or more compounds of formulae VII-1 to VII-9

[0264]

[0265]

[0266] wherein

[0267] R 7 represents a straight-chain alkyl or alkoxy group having 1 to 6 C atoms, or a straight-chain alkenyl group having 2 - 6 C atoms, and

[0268] w is an integer from 1 to 6.

[0269] Preferably, the medium according to the invention comprises one or more compounds of formula VIII:

[0270]

[0271] wherein

[0272] R 81 and R 82 , which are the same or different and represent H, halogen, CN, SCN, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy group having 2 to 15 C atoms or a branched-chain alkyl, alkoxy, alkenyl or alkenyloxy group having 3 to 15 C atoms, wherein one or more CH2 groups in these groups may each independently of one another be

[0273] -C≡C-, -CF2O-, -OCF2-, -CH=CH-, replaced by -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly linked to one another, and wherein one or more H atoms may be replaced by halogen,

[0274] A 0 A 81 , and A 82, each independently represents a phenylene-1,4-diyl group, where one or two CH groups can be replaced by N and one or more H atoms can be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3; a cyclohexane-1,4-diyl group, where one or two non-adjacent CH2 groups can be independently replaced by O and / or S and one or more H atoms can be replaced by F; a cyclohexene-1,4-diyl group; a bicyclo[1.1.1]pentane-1,3-diyl group; a bicyclo[2.2.2]octane-1,4-diyl group; a spiro[3.3]heptane-2,6-diyl group; a tetrahydropyran-2,5-diyl group or a 1,3-dioxane-2,5-diyl group;

[0275] Z 81 and Z 82 , each independently represents -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-, -C2F4, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or a single bond;

[0276] n represents 0, 1, 2 or 3, preferably 0, 1 or 2, very preferably 0 or 1, particularly preferably 0; and

[0277] m represents 0, 1, 2 or 3, preferably 0, 1 or 2, very preferably 1 or 2, especially 1.

[0278] A in formula I 81 and A 82 preferably represents a phenylene-1,4-diyl group which may also be mono- or polysubstituted by F, and a cyclohexane-1,4-diyl group, a cyclohexene-1,4-diyl group, a tetrahydropyran-2,5-diyl group or a 1,3-dioxane-2,5-diyl group, very preferably a phenylene-1,4-diyl group which may also be mono- or polysubstituted by F, or a cyclohexane-1,4-diyl group.

[0279] Z in formula VIII 81 and Z 82 preferably represents -CF2O-, -OCF2- or a single bond, very preferably a single bond.

[0280] A in formula VIII 81 and A 82 particularly preferably represents

[0281] wherein L represents halogen, CF3 or CN, preferably F.

[0282] Compounds of formula VIII are further preferred, wherein R 81 and R 82 each independently of one another represent H, F, or an alkyl, alkoxy, alkenyl or alkynyl group having 1 to 8, preferably 1 to 5 C atoms, each of which is optionally substituted by halogen, in particular by F.

[0283] R 81 and R 82 preferably represent H, an optionally fluorinated alkyl or alkoxy group having 1 to 7 C atoms, an optionally fluorinated alkenyl or alkynyl group having 2 to 7 C atoms, an optionally fluorinated cycloalkyl group having 3 to 12 C atoms.

[0284] Preferably, at least one of R 81 and R 82 is not H, particularly preferably neither R 81 nor R 82 is H. R 81 is very particularly preferably alkyl. R 82 Furthermore, H, alkyl or fluorine are preferred. Very particularly preferably, R 81 is alkyl and R 82 is H or alkyl. R 81 , R 82 each independently of one another very particularly preferably represent unbranched alkyl groups having 1 to 5 C atoms. If R 81 and R 82 represent substituted alkyl, alkoxy, alkenyl or alkynyl groups, the total number of C atoms in the two groups R 81 and R 82 is preferably less than 10.

[0285] Preferred compounds of formula VIII are selected from compounds of formula VIIIa

[0286]

[0287] wherein R 1 and R 2 , which may be the same or different, represent a straight-chain alkyl group having 1 to 15 C atoms, a straight-chain alkenyl group having 2 to 15 C atoms or a branched alkyl or alkenyl group having 3 to 15 C atoms, where one or more CH2 groups in these groups may each independently of one another be replaced, and where one or more H atoms may be replaced by fluorine, preferably both R 1 and R 2 represent straight-chain alkyl groups having 1 to 6 C atoms.

[0288] Very preferred compounds of formula VIIIa are selected from compounds of formulae VIIIa-1 to VIIIa-35:

[0289]

[0290]

[0291]

[0292]

[0293]

[0294] wherein v is an integer from 1 to 6.

[0295] More preferably, the compound of formula VIII is selected from the following sub-formulas:

[0296]

[0297] wherein R 81 , R 82 and L have the above meanings, L preferably represents F, and r, s and t are independently 0, 1, 2, 3, or 4. r is preferably 1 or 2, very preferably 2 and s and t are independently preferably 0 or 1, very preferably 0. R 81 and R 82 in particular independently represent a straight-chain alkyl group having 1 to 5 C atoms.

[0298] In a first very preferred embodiment, the compounds of formulas VIII-1 to VIII-6 are selected from the compounds of formulas VIII-1a to VIII-6a, in particular the compound of formula VIII-3a:

[0299]

[0300] wherein R 81 , R 82 , r and s have the meanings defined above.

[0301] In a second very preferred embodiment, the compounds of formulas VIII-1 to VIII-6 are selected from the compounds of formulas VIII-1b to VIII-6b, in particular the compound of formula I3-b:

[0302]

[0303]

[0304] wherein R 81 , R 82 , L, r and s have the meanings defined above.

[0305] In a third very preferred embodiment, the compounds of formulae VIII-1 to VIII-6 are selected from the compounds of formulae VIII-1c to VIII-6c, especially the compound of formula I3-c:

[0306]

[0307]

[0308] wherein R 81 ,R 82 ,L, r and s have the meanings defined above.

[0309] In a fourth very preferred embodiment, the compounds of formulae VIII-1 to VIII-6 are selected from the compounds of formulae VIII-1d to VIII-6d, especially the compound of formula VIII-3d

[0310]

[0311] wherein R 81 ,R 82 ,L, r and s have the meanings defined above.

[0312] In a particularly preferred embodiment, the medium according to the invention comprises one or more compounds selected from the compounds of formulae VIII-1a to VIII-6a and one or more compounds selected from the compounds of formulae VIII-1b to VIII-6b.

[0313] Very particularly preferably, the medium comprises one or more compounds selected from the group of compounds of formulae VIII-3a, VIII-3b, VIII-3c and VIII-3d:

[0314]

[0315] wherein R 81 ,R 82 ,L and r have the meanings defined above and preferably r is 0. The most preferred compounds of formula I especially include one or more of the following:

[0316]

[0317]

[0318]

[0319] Alternatively or additionally, the following compounds of formula I can be used:

[0320]

[0321]

[0322]

[0323] In a preferred embodiment, the medium comprises one or more compounds of formula IX

[0324] wherein

[0325] R 1 and R 2 , which are the same or different, represent H, halogen, a straight-chain alkyl or alkoxy group having 1 to 15 C atoms, a straight-chain alkenyl or alkenoxy group having 2 to 15 C atoms or a branched alkyl, alkoxy, alkenyl or alkenoxy group each having 3 to 15 C atoms, where one or more CH2 groups in these groups may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, replaced by -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly linked to one another, and where one or more H atoms may be replaced by halogen,

[0326] L 11 and L 12 , each independently of one another, represent F, Cl, CF3 or CHF2,

[0327] L 13 and L 14 , each independently of one another, represent H, F, Cl, CF3 or CHF2,

[0328] Y 1 represents H, F, Cl, CF3, CHF2 or CH3, preferably H or CH3, and

[0329] n is 0 or 1.

[0330] An LC medium preferably comprising a compound of formula IX, wherein n is 0, Y represents H or CH3, more preferably H, and L 11 and L 12 represent F.

[0331] Highly preferred compounds of formula IX are selected from the compounds of formulae IX-1 to IX-35

[0332]

[0333]

[0334]

[0335]

[0336]

[0337] In a preferred embodiment of the present invention, the medium comprises one or more compounds of formula X

[0338]

[0339] wherein

[0340] represents

[0341] represents

[0342] R X represents a straight-chain or branched alkyl or alkoxy group having 1 to 15 carbon atoms, wherein one or more CH2 groups in these groups may each independently of one another be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly linked to one another, and wherein, furthermore, one or more H atoms may be replaced by halogen, preferably by F,

[0343] X X represents F, Cl, CN, SF5, SCN, NCS, a haloalkyl or haloalkoxy group each having 1 to 6 carbon atoms or a haloalkenyl or haloalkenyloxy group each having 2 to 6 carbon atoms,

[0344] Z X represents -C2H4-, -CH2O-, CF2O, -CH=CH- or a single bond.

[0345] In the compound of formula X, R X preferably represents an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, which is preferably straight-chain.

[0346] In the compound of formula X, X X is preferably F, Cl or a mono- or polyfluorinated alkyl or alkoxy group having 1, 2 or 3 carbon atoms, or a mono- or polyfluorinated alkenyl group having 2 or 3 carbon atoms. X XMore preferably F, Cl, CF3, CHF2, OCF3, OCHF2, OCFHCF3, OCFHCHF2, OCFHCHF2, OCF2CH3, OCF2CHF2, OCF2CHF2, OCF2CF2CHF2, OCF2CF2CHF2, OCFHCF2CF3, OCFHCF2CHF2, OCF2CF2CF3, OCF2CF2CClF2, OCClFCF2CF3, OCH=CF2 or CH=CF2, very preferably F or OCF3, furthermore CF3, OCF=CF2, OCHF2 or OCH=CF2, very particularly preferably F, OCF3 or CF3, most preferably F.

[0347] The preferred compounds of formula X are selected from the following sub-formulas:

[0348]

[0349]

[0350] wherein R X has one of the meanings given in formula X, preferably represents a straight-chain alkyl group having 1 to 6 C atoms, very preferably ethyl, propyl or butyl, or a straight-chain alkenyl group having 2 to 6 C atoms, very preferably vinyl or 1-propenyl, most preferably vinyl, and X X has one of the meanings given in formula X and preferably represents F, CF3 or OCF3, very preferably F.

[0351] The very preferred compounds of formula X are selected from the following sub-formulas:

[0352]

[0353]

[0354]

[0355]

[0356]

[0357] Preferably, the LC medium comprises one or more compounds selected from formulas X1-1, X1-3, X2-1 and X2-3.

[0358] The following further preferred embodiments are listed:

[0359] a) A liquid crystal medium which comprises at least one compound of formulas Z-1 to Z-8, preferably compounds of formulas Z-2, Z-4 and Z-6, very preferably the compound of Z-4

[0360]

[0361]

[0362] wherein R Z having the above-mentioned meaning of R 2A preferably represents an alkyl group having 1 to 7 C atoms or an alkenyl group having 2 to 7 C atoms,

[0363] (O) represents O or a single bond, and alkyl represents an alkyl group having 1 to 7 C atoms.

[0364] b) A preferred liquid crystal medium according to the present invention comprises one or more substances containing a tetrahydronaphthyl or naphthyl unit, for example, compounds of formulas N-1 to N-5,

[0365]

[0366]

[0367] wherein R 1N and R 2N each independently of one another have the meaning indicated for R 2A preferably representing a straight-chain alkyl group, a straight-chain alkoxy group or a straight-chain alkenyl group, and

[0368] Z 1 and Z 2 each independently of one another represent -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond.

[0369] c) The preferred mixture comprises one or more compounds selected from difluorodibenzochroman compounds of formula BC, chromans of formula CR, and fluorophenanthrenes of formulas PH-1 and PH-2,

[0370]

[0371]

[0372] wherein R B1 , R B2 , R CR1 , R CR2 , R P1 , R P2 each independently of one another have the meaning of R of formula III 31 ; c is 0, 1 or 2. R1 and R 2 Preferably, each independently represents an alkyl or alkoxy group having 1 to 6 C atoms.

[0373] Particularly preferred BC, CR, and PH-1 compounds of the formula are compounds BC-1 to BC-7, CR-1 to CR-5, and BC-1 to BC-7

[0374]

[0375]

[0376]

[0377] where

[0378] alkyl and alkyl* each independently represent a straight-chain alkyl group having 1 to 6 C atoms, and

[0379] alkenyl and alkenyl* each independently represent a straight-chain alkenyl group having 2 to 6 C atoms.

[0380] Particularly preferred is a mixture comprising one, two, or three compounds of the formula BC-2, BC-3, BP-2, and / or BP-3, very particularly BP-2 and / or BP-3.

[0381] d) The preferred mixture comprises one or more indane compounds of the formula In

[0382]

[0383] where

[0384] R 11 , R 12 , and R 13 each independently represent a straight-chain alkyl, alkoxy, alkoxyalkyl, or alkenyl group having 1 to 6 C atoms,

[0385] R 12 and R 13 alternatively represent halogen, preferably F,

[0386] represents

[0387]

[0388] i represents 0, 1, or 2.

[0389] Preferred compounds of the formula In are compounds In-1 to In-16 as described below:

[0390]

[0391]

[0392] Particularly preferred are the compounds of formulae In-1, In-2, In-3 and In-4.

[0393] e) The preferred mixture additionally contains one or more compounds of formulae L-1 to L-5,

[0394]

[0395] wherein R, R 1 and R 2 each independently of one another have the meanings given above for R in formula IIA, 2A and alkyl represents an alkyl group having 1 to 6 C atoms. The parameter s represents 1 or 2.

[0396] The compounds of formulae L-1 to L-9 are preferably used in a concentration of 5-15 wt%, in particular 5-12 wt% and very particularly preferably 8-10 wt%.

[0397] f) The preferred mixture additionally contains one or more compounds of formula IIA-Y

[0398]

[0399] wherein R 11 and R 12 have one of the meanings given above for R in formula IIA, 2A and L 1 and L 2 identically or differently represent F or Cl,

[0400] The preferred compounds of formula IIA-Y are selected from the following sub-formulae

[0401]

[0402]

[0403] Wherein, Alkyl and Alkyl* each independently of one another represent a straight-chain alkyl group having 1 to 6 C atoms, Alkoxy represents a straight-chain alkoxy group having 1 to 6 C atoms, Alkenyl and Alkenyl* each independently of one another represent a straight-chain alkenyl group having 2 to 6 C atoms, and O represents an oxygen atom or a single bond. Alkenyl and Alkenyl* preferably represent CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0404] Particularly preferred compounds of formula IIA-Y are selected from the following sub-formulas:

[0405]

[0406] Wherein Alkoxy and Alkoxy* have the meanings defined above and preferably represent methoxy, ethoxy, n-propoxy, n-butoxy or n-pentyloxy.

[0407] Preferably, the medium according to the invention comprises a compound selected from the compounds of formulas ST-1 to ST-18, very preferably formula ST-3:

[0408]

[0409]

[0410]

[0411]

[0412] Wherein

[0413] R ST represents H, an alkyl or alkoxy group having 1 to 15 C atoms, wherein, in addition, one or more CH2 groups in these groups may each independently of one another be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-,-O-CO- in such a way that the O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by halogen,

[0414] In each occurrence, identically or differently, represents

[0415] Z STEach independently represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-, -CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond,

[0416] L 1 and L 2 Each independently represents F, Cl, CH3, CF3 or CHF2,

[0417] p represents 0, 1 or 2,

[0418] q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0419] Among the compounds of formula ST, the compounds of the following formula are particularly preferred:

[0420]

[0421] where n = 1, 2, 3, 4, 5, 6 or 7, preferably n

[0422] = 1 or 7

[0423]

[0424] where n = 1, 2, 3, 4, 5, 6 or 7, preferably n

[0425] = 3

[0426]

[0427] where n = 1, 2, 3, 4, 5, 6 or 7, preferably n

[0428] = 3

[0429]

[0430]

[0431]

[0432] In the compounds of formula ST-3a and ST-3b, n preferably represents 3. In the compounds of formula ST-2a, n preferably represents 7.

[0433] A very particularly preferred mixture according to the invention comprises a stabilizer selected from one or more compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12:

[0434]

[0435]

[0436] Preferably, the medium comprises one or more compounds of the formula S

[0437]

[0438] wherein

[0439] Ar represents a methylene group or an aromatic hydrocarbon group having 6 to 40 C atoms or a heteroaromatic hydrocarbon group having 4 to 40 C atoms; preferably an aromatic hydrocarbon group having 6 to 40 C atoms;

[0440] Sp represents a spacer group;

[0441] R S represents H, an alkyl group having 1 to 12 C atoms or an alkenyl group having 2 to 12 C atoms;

[0442] Z S represents -O-, -C(O)O-, -(CH2) z - or -(CH2) z O-, or a single bond;

[0443] HA represents

[0444] R H represents H, O · CH3, OH or OR S ;

[0445] R S1 R S2 R S3 and R S4 independently represent an alkyl group having 1-6 C atoms, preferably having 1-3 C atoms, very preferably CH3;

[0446] G represents H or R S or the group Z S -HA;

[0447] z is an integer from 1 to 6, and

[0448] q is 2, 3 or 4, preferably 3 or 4.

[0449] In formula S, aryl represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms, including one, two, three or four aromatic rings including fused rings, said fused rings being directly linked or linked via an alkylene linking group having 1 to 12 C atoms, where one or more H atoms are optionally replaced by an alkyl or alkoxy group having 1 to 6 C atoms or an alkenyl group having 2 to 6 C atoms, or optionally replaced by CN, CF3 or a halogen, and where one or more CH2 groups may each independently of one another be replaced by -O-, -S-, -NH-, -N(C1-C4-alkyl)-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C- in such a way that O or S atoms are not directly linked to one another.

[0450] Preferred aryls are benzene, naphthalene, anthracene, biphenyl, m-terphenyl, p-terphenyl and (phenylalkyl)benzene, where the alkyl is a straight-chain alkyl having 1-12 C atoms.

[0451] In a preferred embodiment, the medium according to the invention comprises a compound of formula S, where the parameter q is 3 and G represents the group Z S -HA.

[0452] In another preferred embodiment, the medium according to the invention comprises a compound of formula S, where the parameter q is 4 and G represents H or R S .

[0453] The compounds of formula S are preferably selected from the compounds of formulae S-1, S-2 and S-3:

[0454]

[0455]

[0456] where R H has the meanings given above and preferably represents H or O . ,

[0457] Sp is the same or different each time it appears and represents a spacer group, and

[0458] W represents a straight-chain or branched, optionally unsaturated alkylene having 1-12 C atoms, where one or more non-adjacent -CH2- groups may be replaced by -O-.

[0459] Preferred compounds of formula S-1 are selected from the compounds of formula S-1-1:

[0460]

[0461] where R H has the meanings given above and preferably represents H or O. , and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0462] The preferred compound of formula S-2 is selected from the compounds of formula S-2-1:

[0463]

[0464] wherein R H has the meanings given above and preferably represents H or O . , and n2, the same or different each time it appears, preferably the same, is an integer from 1 to 12, preferably 2, 3, 4, 5, or 6, very preferably 3, and R S , the same or different each time it appears, preferably the same, represents an alkyl group having 1 to 6 C atoms, preferably n-butyl.

[0465] The preferred compound of formula S-3 is selected from the compounds of formula S-3-1:

[0466]

[0467] wherein R H has the meanings given above and preferably represents H or O . , and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0468] Based on the mixture, the compounds of formula S and ST-1 to ST-18 are preferably each present in the liquid crystal mixture according to the invention in an amount of 0.005 - 0.5%.

[0469] If the mixture according to the invention contains two or more compounds selected from the compounds of formula S and ST-1 to ST-18, then based on the mixture, in the case of two compounds, the concentration is correspondingly increased to 0.01 - 1%.

[0470] However, based on the mixture according to the invention, the total proportion of the compounds of formula S and ST-1 to ST-18 should not exceed 2%.

[0471] The liquid crystal medium according to the invention (also referred to herein as the liquid crystal host mixture) is suitable for use in polymer-stabilized displays. For this purpose, the medium according to the invention optionally contains one or more polymerizable compounds of formula P:

[0472] P-Sp-A 1 -(Z 1 -A 2 ) z -R P

[0473] where each is independent of one another and the same or different each time it appears

[0474] P represents a polymerizable group,

[0475] Sp represents a spacer group or a single bond,

[0476] A 1 、A 2 represents an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, and which is unsubstituted, or mono- or polysubstituted by L,

[0477] Z 1 represents -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-,-CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH2-CH2-CO-O-, -O-CO-CH2-CH2-, -CR 0 R 00 -, or a single bond,

[0478] R 0 ,R 00 represents H or an alkyl group having 1 to 12 C atoms,

[0479] R represents H, L, or P-Sp-,

[0480] L represents F, Cl, -CN, P-Sp- or a straight-chain, branched-chain or cycloalkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not directly connected to each other, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or Cl,

[0481] z is 0, 1, 2 or 3, and

[0482] n1 is 1, 2, 3 or 4.

[0483] As used herein, the term "reliability" means the quality of the performance of a display over time and under different stress loads, such as light load, temperature, humidity, voltage, and includes display effects such as image sticking (surface and line image sticking), non-uniformity (mura), stain (yogore), etc., which are known to those skilled in the art of LC displays. As a standard parameter for classifying reliability, the voltage holding ratio (VHR) value is usually used, which is a measure for maintaining a constant voltage in a test display. Among other factors, a high VHR is a prerequisite for high reliability of the LC medium.

[0484] Unless otherwise specified, the term "PSA" is used hereinafter when generally referring to a display in which a polymer maintains an alignment type, and the term "PS" is used when referring to a specific display mode (such as PS-VA, PS-TN, etc.).

[0485] As used herein, the terms "active layer" and "switchable layer" denote a layer in an electro-optical display, such as in an LC display, that contains one or more molecules having structural and optical anisotropy (e.g., LC molecules), which change their orientation when subjected to an external stimulus such as an electric or magnetic field, which results in a change in the transmittance of the layer for polarized or non-polarized light.

[0486] As used herein, the terms "tilt" and "tilt angle" should be understood to denote a tilted alignment of the LC molecules of the LC medium with respect to the cell surface in an LC display (preferably a PSA display herein). The tilt angle here represents the average angle (<90°) between the longitudinal molecular axis (LC director) of the LC molecules and the outer plate parallel to the plane forming the LC cell. Here, a low value of the tilt angle (i.e., a large deviation from the 90° angle) corresponds to a large tilt. A suitable method for measuring the tilt angle is given in the examples. Unless otherwise specified, the tilt angle values disclosed in the context are related to this measurement method.

[0487] As used herein, the terms "reactive mesogen" and "RM" should be understood to denote a compound containing a mesogenic or liquid crystal backbone and one or more functional groups suitable for polymerization attached thereto, and the functional groups are also referred to as "polymerizable groups" or "P".

[0488] Unless otherwise specified, the term "polymerizable compound" as used herein should be understood as a polymerizable monomer compound.

[0489] As used herein, the term "low molecular weight compound" should be understood to denote a monomeric and / or a compound not prepared by a polymerization reaction, as opposed to a "polymeric compound" or "polymer".

[0490] As used herein, the term "non-polymerizable compound" is to be understood to denote a compound that does not contain functional groups suitable for polymerization under the conditions normally imposed on the polymerization of RMs.

[0491] As used herein, the term "mesogenic group" is known to those skilled in the art and has been described in the literature, and it denotes a group that substantially contributes to the generation of a liquid crystal (LC) phase in a low molecular weight or polymeric material due to the anisotropy of its attractive and repulsive interactions. A compound containing a mesogenic group (mesogenic compound) does not necessarily have an LC phase per se. The mesogenic compound may also exhibit LC phase behavior only after mixing with other compounds and / or after polymerization. Typical mesogenic groups are, for example, rigid rod-like or disc-like units. An overview of the terms and definitions used in connection with mesogenic or LC compounds is given in Pure Appl.Chem.2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew.Chem.2004, 116, 6340 - 6368.

[0492] As used herein, the terms "optically active" and "chiral" are synonyms for a material that can induce a helical pitch in a nematic host material, also referred to as a "chiral dopant".

[0493] As used herein, the term "spacer group" (also referred to as "Sp" in the context) is known to those skilled in the art from the prior art and has been described in the literature, see, for example, Pure Appl.Chem.2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew.Chem.2004, 116, 6340 - 6368. As used herein, the term "spacer group" or "spacer" denotes a flexible group, for example, an alkylene group, which connects the mesogenic group and the polymerizable group(s) in a polymerizable mesogenic compound.

[0494] Likewise, in the compounds of formula I, the spacer group connects the central hydrocarbon group to the optically active, sterically hindered amine functional group.

[0495] In the context, represents a trans - 1,4 - cyclohexylene ring.

[0496] In the group the single bond shown between the two ring atoms can be connected to any free position of the benzene ring.

[0497] The "organic group" in the context denotes a carbon or hydrocarbon group.

[0498] "Carbon group" means a mono- or polyvalent organic group containing at least one carbon atom, where the group does not contain other atoms (such as -C≡C-) or optionally contains one or more other atoms, such as N, O, S, B, P, Si, Se, As, Te or Ge (such as carbonyl, etc.). The term "hydrocarbyl group" means a carbon group that additionally contains one or more H atoms and optionally one or more heteroatoms, such as N, O, S, B, P, Si, Se, As, Te or Ge.

[0499] "Halogen" means F, Cl, Br or I, preferably F or Cl.

[0500] -CO-, -C(=O)- and -C(O)- represent a carbonyl group, i.e.,

[0501] The carbon or hydrocarbyl group can be a saturated or unsaturated group. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. A carbon or hydrocarbyl group having more than 3 C atoms can be straight-chain, branched and / or cyclic and can also contain spiro linkages or fused rings.

[0502] The terms "alkyl", "aryl", "heteroaryl", etc. also include polyvalent groups, such as alkylene, arylene, heteroarylene, etc.

[0503] The term "aryl" means an aromatic carbon group or a group derived therefrom. The term "heteroaryl" means an "aryl" as defined above that contains one or more heteroatoms (preferably selected from N, O, S, Se, Te, Si and Ge).

[0504] Preferred carbon and hydrocarbyl groups are optionally substituted, straight-chain, branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having 1 to 40, preferably 1 to 20, very preferably 1 to 12 C atoms, optionally substituted aryl or aryloxy having 5 to 30, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, aralkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25 C atoms, where one or more C atoms can also be replaced by heteroatoms (preferably selected from N, O, S, Se, Te, Si and Ge).

[0505] Further preferred carbon and hydrocarbyl groups are C1-C 20 alkyl, C2-C 20 alkenyl, C2-C 20 alkynyl, C3-C 20 allyl, C4-C 20 alkyl diene, C4-C 20 polyene, C6-C 20Naphthenyl, C4-C 15 Cycloalkenyl, C6-C 30 Aryl, C6-C 30 Alkylaryl, C6-C 30 Aralkyl, C6-C 30 Alkylaryloxy, C6-C 30 Arylalkyloxy, C2-C 30 Heteroaryl, C2-C 30 Heteroaryloxy.

[0506] Particularly preferred are C1-C 12 Alkyl, C2-C 12 Alkenyl, C2-C 12 Alkynyl, C6-C 25 Aryl and C2-C 25 Heteroaryl.

[0507] Further preferred carbon-based and hydrocarbon-based groups are straight-chain, branched-chain or cyclic alkyl groups having 1-20, preferably 1-12 C atoms, which are unsubstituted or mono- or poly-substituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH2 groups can each be independently of one another replaced by -C(R x )=C(R x )-, -C≡-, -N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not directly linked to one another.

[0508] R x Preferably represents H, F, Cl, CN, a straight-chain, branched-chain or cyclic alkyl chain having 1 to 25 C atoms, in which additionally one or more non-adjacent C atoms can be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and in which one or more H atoms can be replaced by F or Cl, or represents an optionally substituted aryl or aryloxy group having 6 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 30 C atoms.

[0509] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecyl, trifluoromethyl, perfluorobutyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, etc.

[0510] Preferred alkenyl groups are, for example, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.

[0511] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

[0512] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, 2-methylbutoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, etc.

[0513] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.

[0514] Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e., they can contain one ring (e.g., phenyl) or two or more rings, which can also be fused (e.g., naphthyl) or covalently bonded (e.g., biphenyl), or contain a combination of fused and linked rings. Heteroaryl contains one or more heteroatoms, preferably selected from O, N, S, and Se.

[0515] Particularly preferred are mono-, bi- or tricyclic aryls having 6 - 25 C atoms and mono-, bi- or tricyclic heteroaryls having 5 - 25 ring atoms, which optionally contain fused rings and are optionally substituted. Further preferred are 5-, 6- or 7-membered aryls and heteroaryls, wherein additionally, one or more CH groups can be replaced by N, S or O in such a way that O atoms and / or S atoms are not directly connected to each other.

[0516] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1':3',1”]terphenyl-2'-yl, naphthyl, anthracenyl, binaphthyl, phenanthryl, 9,10-dihydro-phenanthryl, pyrene, dihydropyrene, picene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, etc.

[0517] Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine or fused groups such as indole, isoindole, indene, indazole, benzimidazole, benzotriazole, purine, naphthimidazole, phenanthrimidazole, pyridinimidazole, pyrazinimidazole, quinoxalinimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarbazole, phenanthridine, phenanthroline, thiophene[2,3b]thiophene, thiophene[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiophene, benzothiadiazolethiophene, or combinations of these groups.

[0518] The aryl and heteroaryl groups mentioned in the context may also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or other aryl or heteroaryl groups.

[0519] (Non-aromatic) alicyclic groups and heterocyclic groups include both saturated rings, i.e., rings containing only single bonds, and partially unsaturated rings, i.e., those that may also contain multiple bonds. Heterocycles contain one or more heteroatoms, preferably selected from Si, O, N, S, and Se.

[0520] (Non-aromatic) alicyclic groups and heterocyclic groups may be monocyclic, i.e., containing only one ring (such as cyclohexane), or polycyclic, i.e., containing multiple rings (such as decalin or bicyclooctane). Saturated groups are particularly preferred. Also preferred are mono-, bi- or tricyclic groups having 5-25 ring atoms, which optionally contain fused rings and are optionally substituted. Further preferred are 5-, 6-, 7- or 8-membered carbocyclic groups, wherein additionally, one or more C atoms may be replaced by Si and / or one or more CH groups may be replaced by N and / or one or more non-adjacent CH2 groups may be replaced by -O- and / or -S-.

[0521] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiophene, pyrrolidine; 6-membered groups such as cyclohexane, silinane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine; 7-membered groups such as cycloheptane; and fused groups such as tetralin, decalin, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindane-2,5-diyl.

[0522] Preferred substituents are, for example, solubility-promoting groups such as alkyl or alkoxy groups; electron-withdrawing groups such as fluorine, nitro or nitrile; or substituents for increasing the glass transition temperature (Tg) of the polymer, in particular bulky groups such as tert-butyl or optionally substituted aryl.

[0523] Preferred substituents, also referred to hereinafter as "L" S ", 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, a straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group each having 1 to 25 C atoms, where one or more H atoms may optionally be replaced by F or Cl, an optionally substituted silyl group having 1 to 20 Si atoms, or an optionally substituted aryl group having 6 to 25, preferably 6 to 15 C atoms.

[0524] where R x represents H, F, Cl, CN, or a straight-chain, branched or cyclic alkyl group having 1 to 25 C atoms, where one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O- and / or S-atoms are not directly linked to each other, and where one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-, and

[0525] Y 1 represents halogen.

[0526] "Substituted silyl or aryl" preferably means that it is substituted by halogen, -CN, R 0 , -OR 0 , -CO-R 0 , -CO-O-R 0, -O-CO-R 0 or -O-CO-O-R 0 is substituted, where R 0 represents H or an alkyl group having 1 to 20 C atoms.

[0527] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and in addition phenyl.

[0528] A 1 and A 2 very preferably represents where L has one of the above meanings and r represents 0, 1, 2, 3 or 4, in particular

[0529] represents

[0530] The polymerizable group P is a group suitable for polymerization reactions (such as free radical or ionic chain polymerization, addition polymerization or condensation polymerization), or a group suitable for polymer-analogous reactions (such as addition or condensation on the polymer backbone). Particularly preferred are groups for chain polymerization, especially those containing a C═C double bond or a -C≡C- triple bond, and groups suitable for ring-opening polymerization, such as oxetanyl or epoxy groups.

[0531] Preferred groups P are selected from the group consisting of: CH2═CW 1 -CO-O-, CH2═CW 1 -CO-,

[0532] CH2═CW 2 -(O) k3 -, CW 1 ═CH-CO-(O) k3 -, CW 1 ═CH-CO-NH-, CH2═CW 1 -CO-NH-,

[0533] CH3-CH═CH-O-, (CH2═CH)2CH-OCO-, (CH2═CH-CH2)2CH-OCO-,

[0534] (CH2═CH)2CH-O-, (CH2═CH-CH2)2N-, (CH2═CH-CH2)2N-CO-, HO-CW 2 W3 - HS-CW 2 W 3 - HW 2 N- HO-CW 2 W 3 -NH- CH2=CW 1 -CO-NH- CH2=CH-(COO) k1 -Phe-(O) k2 - CH2=CH-(CO) k1 -Phe-(O) k2 - Phe-CH=CH- HOOC- OCN- and W 4 W 5 W 6 Si-, where W 1 represents H, F, Cl, CN, CF3, phenyl or an alkyl group having 1 to 5 C atoms, especially H, F, Cl or CH3, W 2 and W 3 each independently of one another represents H or an alkyl group having 1 to 5 C atoms, especially H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently of one another represents Cl, an oxaalkyl group or an oxacarbonylalkyl group having 1 to 5 C atoms, W 7 and W 8 each independently of one another represents H, Cl or an alkyl group having 1 to 5 C atoms, Phe represents 1,4-phenylene, which is optionally substituted by one or more groups L different from P-SP- as defined above, k1, k2 and k3 each independently of one another represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0535] Very preferred groups P are selected from the group consisting of: CH2=CW 1 -CO-O- CH2=CW 1 -CO- CH2=CW 2 -O- CH2=CW 2 - CW 1 =CH-CO-(O) k3 - CW 1 =CH-CO-NH- CH2=CW 1 -CO-NH- (CH2=CH)2CH-OCO- (CH2=CH-CH2)2CH-OCO- (CH2=CH)2CH-O- (CH2=CH-CH2)2N- (CH2=CH-CH2)2N-CO- CH2=CW1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si-, where W 1 represents H, F, Cl, CN, CF3, phenyl or an alkyl group having 1 to 5 C atoms, especially H, F, Cl or CH3, W 2 and W 3 each independently of one another represents H or an alkyl group having 1 to 5 C atoms, especially H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently of one another represents Cl, an oxaalkyl group or an oxacarbonylalkyl group having 1 to 5 C atoms, W 7 and W 8 each independently of one another represents H, Cl or an alkyl group having 1 to 5 C atoms, Phe represents 1,4-phenylene, k1, k2 and k3 each independently of one another represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0536] Very particularly preferred groups P are selected from the group consisting of CH2=CW 1 -CO-O-, especially CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, also CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-,

[0537] Other preferred polymerizable groups P are selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetanyl and epoxy groups, most preferably from acrylate and methacrylate groups.

[0538] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X" such that the respective groups P-Sp- correspond to the formula R-Sp"-X"-, where

[0539] Sp" represents a straight-chain or branched alkylene group having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and where additionally, one or more non-adjacent CH2 groups are each independently of one another replaced by -O-, -S-, -NH-, -N(R0 )-, -Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-, -O-CO-N(R 0 )-, -N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C- are replaced in such a way that O and / or S atoms are not directly connected to each other,

[0540] X" represents -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-, -N(R 0 )-CO-, -N(R 0 )-CO-N(R 00 )-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -, -CY 2 =CY 3 -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond,

[0541] R 0 and R 00 each independently of one another represent H or an alkyl group having 1 - 20 C atoms, and

[0542] Y 2 and Y 3 each independently of one another represent H, F, Cl or CN.

[0543] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 00 - or a single bond.

[0544] Typical spacer groups Sp and -Sp"-X"- are for example -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1-CO-O-, -(CH2) p1 -O-CO-O-, -(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR 0 R 00 -O) p1 -, where p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 have the meanings indicated above.

[0545] Particularly preferred groups Sp and -Sp"-X"- are -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, where p1 and q1 have the meanings indicated above.

[0546] Particularly preferred groups Sp" are, in each case, straight-chain ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethyl-N-methylimino-ethylene, 1-methylalkylene, vinyl, propenyl and butenyl.

[0547] In a preferred embodiment of the present invention, the compounds of formula P and its sub-formulas contain a spacer group Sp substituted by one or more polymerizable groups P such that the group Sp-P corresponds to Sp(P) s , where s is ≥ 2 (branched polymerizable group).

[0548] Preferred compounds of formula P according to this preferred embodiment are those in which s is 2, i.e., compounds containing the group Sp(P)2. Very preferred compounds of formula P according to this preferred embodiment contain a group selected from the following formulas:

[0549] -X-alkyl-CHPP S1

[0550] -X-alkyl-CH((CH2) aa P)((CH2) bb P) S2

[0551] -X-N((CH2) aa P)((CH2) bb P) S3

[0552] -X-alkyl-CHP-CH2-CH2P S4

[0553] -X-alkyl-C(CH2P)(CH2P)-C aa H 2aa+1 S5

[0554] -X-alkyl-CHP-CH2P S6

[0555] -X-alkyl-CPP-C aa H 2aa+1 S7

[0556] -X-alkyl-CHPCHP-C aa H 2aa+1 S8

[0557] wherein P is as defined in formula P,

[0558] alkyl represents a single bond or a straight-chain or branched alkylene group having 1 to 12 C atoms, which is unsubstituted or mono- or polysubstituted by F, Cl or CN, and one or more non-adjacent CH2 groups may each independently of one another be replaced by -C(R 0 )=C(R 0 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- such that the O atoms and / or S atoms are not directly linked to one another, where R 0 has the meaning indicated above,

[0559] aa and bb each independently of one another represent 0, 1, 2, 3, 4, 5 or 6,

[0560] X has one of the meanings indicated for X", and is preferably O, CO, SO2, O-CO-, CO-O or a single bond.

[0561] Preferred spacer groups Sp(P)2 are selected from formulae S1, S2 and S3.

[0562] Very preferred spacer groups Sp(P)2 are selected from the following sub-formulae:

[0563] -CHPP S1a

[0564] -O-CHPP S1b

[0565] -CH2-CHPP S1c

[0566] -OCH2-CHPP S1d

[0567] -CH(CH2-P)(CH2-P) S2a

[0568] -OCH(CH2-P)(CH2-P) S2b

[0569] -CH2-CH(CH2-P)(CH2-P) S2c

[0570] -OCH2-CH(CH2-P)(CH2-P) S2d

[0571] -CO-NH((CH2)2P)((CH2)2P) S3a

[0572] In the compounds of formula P and its sub-formulas as described above and below, P is preferably selected from the group consisting of: vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, and most preferably selected from acrylate and methacrylate.

[0573] More preferably, the compounds are those of formula P and its sub-formulas as described above and below, wherein all polymerizable groups P present in the compound have the same meaning, and very preferably represent acrylate or methacrylate, and most preferably methacrylate.

[0574] In the compounds of formula P and its sub-formulas as described above and below, R preferably represents P-Sp-.

[0575] More preferably, the compounds are those of formula P and its sub-formulas as described above and below, wherein Sp represents a single bond or -(CH2) p1 -,-O-(CH2) p1 -,-O-CO-(CH2) p1 or -CO-O-(CH2) p1 , where p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH2) p1 -,-O-CO-(CH2) p1 or -CO-O-(CH2) p1 , then the O-atom or the CO-group is attached to the benzene ring, respectively.

[0576] More preferably, the compounds are those of formula P and its sub-formulas as described above and below, wherein at least one group Sp is a single bond.

[0577] More preferably, the compounds are those of formula P and its sub-formulas as described above and below, wherein at least one group Sp is different from a single bond, and is preferably selected from -(CH2) p1 -,-O-(CH2) p1 -,-O-CO-(CH2) p1 or -CO-O-(CH2)p1 , where p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 , then the O-atom or the CO-group is attached to the benzene ring, respectively.

[0578] The very preferred group -A in formula P 1 -(Z-A 2 ) z - is selected from the following formulas

[0579]

[0580]

[0581] where at least one benzene ring is substituted by at least one group L and the benzene ring is optionally further substituted by one or more groups L or P-Sp-.

[0582] The preferred compounds of formula P and its sub-formulas are selected from the following preferred embodiments, including any combination thereof:

[0583] - All groups P in the compound have the same meaning,

[0584] --A 1 -(Z-A 2 ) z - is selected from formulas A1, A2 and A5,

[0585] - The compound contains exactly two polymerizable groups (represented by the group P),

[0586] - The compound contains exactly three polymerizable groups (represented by the group P),

[0587] - P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate,

[0588] - P is methacrylate,

[0589] - All groups Sp are single bonds,

[0590] - At least one of the groups Sp is a single bond and at least one of the groups Sp is different from a single bond,

[0591] - When Sp is different from a single bond, it is -(CH2) p2 -, -(CH2) p2 -O-, -(CH2) p2 -CO-O-, -(CH2) p2-O-CO-, where p2 is 2, 3, 4, 5 or 6, and the O atom or the CO-group is connected to the benzene ring respectively,

[0592] -Sp is a single bond or represents -(CH2) p2 -, -(CH2) p2 -O-, -(CH2) p2 -CO-O-, -(CH2) p2 -O-CO-, where p2 is 2, 3, 4, 5 or 6, and the O atom or the CO-group is connected to the benzene ring respectively,

[0593] -R represents P-Sp-,

[0594] -R does not represent or contain a polymerizable group,

[0595] -R does not represent or contain a polymerizable group and represents a straight-chain, branched-chain or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and wherein one or more H atoms are each optionally replaced by F, Cl or L a replaced,

[0596] -L or L’ represents F, Cl or CN,

[0597] -L is F.

[0598] Suitable and preferred compounds of formula P are selected from the following formulas:

[0599]

[0600]

[0601]

[0602]

[0603] wherein each group has the following meanings:

[0604] P 1 、P 2 and P 3 each independently of one another represents an acrylate group or a methacrylate group,

[0605] Sp 1 、Sp 2 and Sp 3 each independently of one another represents a single bond or a spacer group (having one of the meanings as described for Sp in the context), and particularly preferably represents -(CH2) p1-, -(CH2) p1 -O-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO- or -(CH2) p1 -O-CO-O-, where p1 is an integer from 1 to 12, and in addition where the group P 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 - in one or more of them can represent R aa , provided that the group P present 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 - in at least one of them is different from R aa ,

[0606] R aa represents H, F, Cl, CN or a straight-chain or branched alkyl group having 1 to 25 C atoms, where one or more additional non-adjacent CH2 groups can also each be independently replaced by C(R 0 )=C(R 00 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not directly connected to each other, and where one or more additional H atoms can be replaced by F, Cl, CN or P 1 -Sp 1 -, particularly preferably a straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy group having 1 to 12 C atoms (where alkenyl and alkynyl groups have at least two C atoms and branched groups have at least three C atoms),

[0607] R 0 , R 00 each independently of one another and each time they appear the same or different, represent H or an alkyl group having 1 to 12 C atoms,

[0608] R y and R z each independently of one another represent H, F, CH3 or CF3,

[0609] X 1 、X 2 and X 3each independently represents -CO-O-, -O-CO- or a single bond,

[0610] Z 1 represents -O-, -CO-, -C(R y R z )- or -CF2CF2-,

[0611] Z 2 and Z 3 each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2) n -, where n is 2, 3 or 4,

[0612] L, each occurrence being the same or different, represents F, Cl, CN or a straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, preferably F,

[0613] L' and L” each independently represent H, F or Cl,

[0614] k represents 0 or 1,

[0615] r represents 0, 1, 2, 3 or 4,

[0616] s represents 0, 1, 2 or 3,

[0617] t represents 0, 1 or 2,

[0618] x represents 0 or 1.

[0619] Particularly preferred are the compounds of the formulas P2, P13, P17, P22, P23, P24, P30, P31 and P32.

[0620] Further preferred are the tri-reactive compounds P15 to P30, in particular P17, P18, P19, P22, P23, P24, P25, P26, P30, P31 and P32.

[0621] In the compounds of the formulas P1 to P32, the groups

[0622] preferably

[0623]

[0624] Wherein L, each time it appears, is the same or different and has one of the meanings given above or below, and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, OCH3, COCH3 or OCF3, especially F or CH3.

[0625] The very particularly preferred compounds of formula P are selected from Table E below.

[0626] For the production of PSA displays, the polymerizable compounds contained in the LC medium are polymerized or crosslinked (if a compound contains two or more polymerizable groups) by in-situ polymerization in the LC medium (between the substrates of the LC display), optionally while applying a voltage to the electrodes simultaneously.

[0627] The structure of the PSA display according to the invention corresponds to the usual geometry of PSA displays, as described in the prior art cited at the beginning. A geometry without protrusions is preferred, wherein, in addition, especially those in which the electrodes on the color filter side are unstructured and only the electrodes on the TFT side have slots. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US2006 / 0066793A1.

[0628] The preferred PS-type LC display of the present invention comprises:

[0629] - A first substrate, which includes a pixel electrode defining a pixel region (the pixel electrode is connected to a switching element arranged in each pixel region and optionally includes a micro-slit pattern), and optionally a first alignment layer arranged on the pixel electrode,

[0630] - A second substrate, which includes a common electrode layer (which can be arranged on the entire part of the second substrate facing the first substrate), and optionally a second alignment layer,

[0631] - An LC layer, the LC layer is arranged between the first substrate and the second substrate, and includes an LC medium, the LC medium includes a polymerizable component and a liquid crystal host, the polymerizable component includes one or more compounds of formula R, the liquid crystal host includes as described above and below, wherein the polymerizable component can also be polymerized.

[0632] The first and / or second alignment layer controls the alignment direction of the LC molecules in the LC layer. For example, in a PS-VA display, an alignment layer is selected to impart a homeotropic (or vertical) alignment (i.e., perpendicular to the surface) or an inclined alignment to the LC molecules. Such an alignment layer may comprise, for example, polyimide, which may also be rubbed or may be prepared by a photo-alignment method.

[0633] The LC layer having the LC medium can be deposited between the substrates of the display by methods conventionally used by display manufacturers (such as the so-called one-drop filling (ODF) method). The polymerizable components of the LC medium are then polymerized, for example, by UV photopolymerization. This polymerization can be carried out in one step or in two or more steps.

[0634] The PSA display may include other elements, such as color filters, black matrices, passivation layers, optical retardation layers, transistor elements for individual pixel addressing, etc., all of which are well known to those skilled in the art and can be used without creative skills.

[0635] Those skilled in the art can design the electrode structure depending on the individual display type. For example, in a PS-VA display, a multi-domain alignment of the LC molecules can be induced by providing electrodes having slits and / or bumps or protrusions in order to generate two, four or more different inclined alignment directions.

[0636] After polymerization, the polymerizable compound forms a crosslinked polymer, which results in a certain pretilt of the LC molecules in the LC medium. Without wishing to be bound by a particular theory, it is believed that at least a portion of the crosslinked polymer formed by the polymerizable compound phase separates or precipitates from the LC medium and forms a polymer layer on the substrate or electrode, or on the alignment layer provided thereon. Microscopic measurement data (such as SEM and AFM) have confirmed that at least a portion of the formed polymer accumulates at the LC / substrate interface.

[0637] The polymerization can be carried out in one step. It is also possible to first carry out the polymerization in a first step (optionally while applying a voltage) in order to generate a pretilt angle, and then polymerize or crosslink the compounds that did not react in the first step in a second polymerization step without applying a voltage ("final curing").

[0638] Suitable and preferred polymerization methods are, for example, thermal or photopolymerization, preferably photopolymerization, especially UV-induced photopolymerization, which can be achieved by exposing the polymerizable compound to UV radiation.

[0639] Optionally, one or more polymerization initiators are added to the LC medium. Suitable conditions for polymerization, suitable types and amounts of initiators are known to those skilled in the art and are described in the literature. Suitable for free radical polymerization are, for example, commercially available photoinitiators or (Ciba AG). If a polymerization initiator is used, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

[0640] The polymerizable compounds according to the invention are also suitable for polymerization without initiator, which is accompanied by a number of advantages, such as low material costs and in particular less contamination of the LC medium by possible residual amounts of initiator or its degradation products. Polymerization can thus also be carried out without addition of an initiator. In a preferred embodiment, the LC medium thus does not contain a polymerization initiator.

[0641] The LC medium may also contain one or more stabilizers in order to prevent spontaneous polymerization of unwanted RMs, for example during storage or transport. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Particularly suitable are, for example, stabilizers commercially available from the series (Ciba AG), such as 1076. If stabilizers are used, their proportion is preferably 10 - 500,000 ppm, particularly preferably 50 - 50,000 ppm, based on the total amount of RM or polymerizable components (component P).

[0642] The polymerizable compounds of formula P do in fact particularly exhibit good UV absorption and are thus particularly suitable for production methods of PSA displays comprising one or more of the following features:

[0643] - The polymerizable medium in the display is exposed to UV light in a two-step process, which includes a first UV exposure step ("UV-1 step") to generate an inclination angle, and a second UV exposure step ("UV-2 step") to complete the polymerization,

[0644] - The polymerizable medium in the display is exposed to UV light generated by energy-saving UV lamps (also called "green UV lamps"). These lamps are characterized by a relatively low intensity in their absorption spectrum of 300 - 380 nm (1 / 100 - 1 / 10 of a conventional UV1 lamp), and are preferably used in the UV2 step, but may also optionally be used in the UV1 step when it is necessary to avoid high intensities for the process.

[0645] - The polymerizable medium in the display is exposed to UV light generated by a UV lamp, which has a radiation spectrum shifted to longer wavelengths (preferably 340 nm or longer) to avoid short UV light exposure in the PS-VA process.

[0646] Both low-intensity and UV shifted to longer wavelengths are used to protect the organic layer from damage that may be caused by UV light.

[0647] Preferred embodiments of the present invention relate to methods of preparing PSA displays as described in context, which include one or more of the following features:

[0648] - The polymerizable LC medium is exposed to UV light in a two-step process that includes a first UV exposure step (“UV-1 step”) to create antiltilt angles and a second UV exposure step (“UV-2 step”) to complete polymerization.

[0649] - The polymerizable LC medium is exposed to UV light having an intensity of from 0.5 mW / cm 2 to 10 mW / cm 2 in the wavelength range of 300 - 380 nm, preferably for the UV2 step and optionally also for the UV1 step, generated by a UV lamp.

[0650] - The polymerizable LC medium is exposed to UV light having a wavelength of 340 nm or longer and preferably 400 nm or shorter.

[0651] This preferred method is carried out, for example, by using a desired UV lamp or by using a bandpass filter and / or a cutoff filter that is substantially transmissive for UV light having respective desired wavelengths and substantially blocks UV light having respective undesired wavelengths. For example, when radiation of UV light having a wavelength λ in the range of 300 - 400 nm is desired, the UV exposure can be carried out using a broadband pass filter that is substantially transmissive for wavelengths 300 nm < λ < 400 nm. When radiation of UV light having a wavelength λ greater than 340 nm is desired, the UV exposure can be carried out using a cutoff filter that is substantially transmissive for wavelengths λ > 340 nm.

[0652] “Substantially transmissive” means that the filter transmits most, preferably at least 50%, of the intensity of the incident light at the desired wavelength. “Substantially blocks” means that the filter does not transmit most, preferably at least 50%, of the intensity of the incident light at the undesired wavelength. “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.

[0653] This preferred method makes it possible to manufacture displays using longer UV wavelengths, thereby reducing or even avoiding the harmful and damaging effects of short UV light components.

[0654] The UV radiation energy is generally from 6 to 100 J, depending on the production method conditions.

[0655] Preferably, the LC medium according to the present invention consists essentially of a polymerizable component P) comprising one or more polymerizable compounds of formula P as described above and below, and an LC host mixture, and an optically active component comprising one or more chiral dopants. However, the LC medium may additionally contain one or more other components or additives, preferably selected from the list including but not limited to: comonomers, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, water repellents, binders, flow improvers, defoamers, degassing agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments, and nanoparticles.

[0656] Particularly preferred is an LC medium containing one, two or three polymerizable compounds of formula P.

[0657] The proportion of the preferred compound of formula P in the LC medium is >0 to <5%, very preferably >0 to <1%, and most preferably 0.01 to 0.5%.

[0658] In a preferred embodiment, the medium according to the present invention preferably contains one or more compounds of formula S, with a total concentration ranging from 10 ppm to 2000 ppm, more preferably from 100 ppm to 1000 ppm, still more preferably from 150 ppm to 500 ppm, very preferably from 200 ppm to 400 ppm, and especially from 250 to 300 ppm.

[0659] In another preferred embodiment, the medium according to the present invention preferably contains one or more compounds of formula S, with a total concentration ranging from 1000 ppm to 5000 ppm, more preferably more than 1000 ppm to 5000 ppm, still more preferably from 1200 ppm to 4500 ppm, very preferably from 2000 ppm to 4000 ppm, and especially from 2500 to 3500 ppm.

[0660] The medium according to the present invention preferably has negative dielectric anisotropy.

[0661] The medium according to the present invention contains a compound of formula I in a concentration range of 1% to 35%, preferably 5% to 30%, more preferably 6% to 26%, very preferably 8% to 25%, and

[0662] a compound of formula CPY in a concentration range of 1% to 15%, preferably 2% to 14%, more preferably 3% to 13%, very preferably 4% to 12%.

[0663] Preferred embodiments, either alone or in combination with each other, are as follows.

[0664] According to a first preferred embodiment of the invention, the birefringence of the medium is in the range from 0.120 to 0.150, more preferably from 0.125 to 0.145, and in particular from 0.128 to 0.138.

[0665] The medium according to the first preferred embodiment preferably comprises:

[0666] - one or more compounds of formula IIA in a total amount of less than 3%, more preferably less than 2%, and very preferably less than 1%;

[0667] or

[0668] - one or more compounds of formula IIA in an amount from 0% to 1%, very preferably 0%;

[0669] and / or

[0670] - one or more compounds of formula IIB and CPY, preferably formula IIB-2 and / or IIB-10 and CPY, more preferably formula IIB-2 and IIB-10 and CPY, in a total concentration range from 10% to 50%, more preferably from 15% to 45%, still more preferably from 20% to 40%, and in particular from 26% to 37%;

[0671] and / or

[0672] - one or more compounds of formula IIC, preferably in a total concentration range from 1% to 15%, more preferably from 1.5% to 12% and very preferably from 3% to 10%;

[0673] and / or

[0674] - one or more compounds of formula IID in an amount less than 2%, preferably 0%;

[0675] and / or

[0676] - one or more compounds of formula III, preferably formula III-2 and / or III-3, more preferably formula III-2-6 and / or III-3, in particular one or more compounds B(S)-nO-Om and / or COB(S)-n-Om, very particularly B(S)-2O-O4, B(S)-2O-O5, B(S)-2O-O6, and / or COB(S)-2-O4, preferably in a total concentration range from 3% to 20%, more preferably from 3% to 17% and very preferably from 4% to 15%;

[0677] and / or

[0678] - one or more compounds of formula VI-1-4, preferably in a total concentration range from 1% to 15%, more preferably from 2% to 12% and very preferably from 3% to 10%;

[0679] and / or

[0680] - One or more compounds of Formula IIC and VI-1-4, preferably in a total concentration range of 1% to 18%, more preferably 3% to 15% and very preferably 4% to 13%;

[0681] - One or more compounds selected from the following: compounds of Formula CPY, IIA, IIB, IIC, IID, III and VI-1-4, preferably Formula CPY, IIB, IIC and optionally VI-1-4, in a total concentration range of 32% to 70%, more preferably 38% to 65% and very preferably 45% to 60%;

[0682] and / or

[0683] - A compound of Formula I and one or more compounds of Formula IV, more preferably Formula I and IV-3, in a total concentration range of 20% to 65%, more preferably 23% to 58%, still more preferably 26% to 50% and very preferably 28% to 45%, especially 30% to 42%;

[0684] and / or

[0685] - A compound of Formula I and a compound of Formula IV-3-2b, preferably in a total concentration range of 20% to 40%, more preferably 22% to 38% especially 24% to 32%;

[0686] and / or

[0687] - One or more compounds of Formula IVb, more preferably Formula IVb-2, in a total concentration range of 1% to 15%, more preferably 2% to 12%, very preferably 4% to 10%;

[0688] and / or

[0689] - One or more compounds of Formula V, more preferably Formula V-2-1 and / or V-2-2, preferably in a total concentration range of 1% to 18%, more preferably 2% to 15%, very preferably 3% to 10%;

[0690] and / or

[0691] One or more compounds of Formula IIA-Y, preferably Formula IIA-Y6, in a total concentration range of 0.5% to 10%, more preferably 1% to 8%, and very preferably 2% to 5%;

[0692] and / or

[0693] One or more compounds of Formula CL, more preferably Formula CL-3, very preferably selected from Formula CLP-V-m, CLP-V-Om, CLP-n-m, and CLP-n-Om, where n and m are independently 1, 2, 3, 4 or 5, preferably in a total concentration range of 1% to 12%, more preferably 2% to 10% and very preferably 3% to 7%.

[0694] For the liquid crystal medium according to the invention, it is advantageous to have a nematic phase of ≤ -20 °C to ≥ 70 °C, particularly preferably ≤ -30 °C to ≥ 72 °C, and very particularly preferably ≤ -40 °C to ≥ 74 °C.

[0695] In a first preferred embodiment, the medium according to the invention has a clearing temperature of 70 °C or higher, preferably 72 °C or higher, more preferably 73 °C or higher and in particular 74 °C or higher.

[0696] The expression "having a nematic phase" here means on the one hand that no smectic phase and no crystallization are observed at low temperatures at the corresponding temperature and on the other hand that it does not become clear (phase transition to the isotropic phase) when heated from the nematic phase. The low-temperature studies are carried out in a flow viscometer at the corresponding temperature and are checked by storing in a test cell with a layer thickness corresponding to electro-optical use for at least 100 hours. If the storage stability in the corresponding test cell at a temperature of -20 °C is 1000 hours or more, the medium is called stable at this temperature. At temperatures of -30 °C and -40 °C, the response times are 500 hours and 250 hours respectively. At high temperatures, the clearing point is measured in a capillary by a conventional method.

[0697] The liquid crystal mixture according to the invention is nematic, preferably at a temperature of -20 °C or lower, preferably at -30 °C or lower, and very preferably at -40 °C or lower.

[0698] In a preferred embodiment, the dielectric anisotropy Δε of the liquid crystal mixture according to the invention is from -2.0 to -5.0, preferably from -2.5 to -4.0, and in particular from -2.8 to -3.3.

[0699] In a preferred embodiment, the dielectric anisotropy Δε of the liquid crystal mixture according to the invention is from -2.5 to -6.0, preferably from -2.8 to -5.0, and in particular from -3.0 to -4.3.

[0700] The rotational viscosity γ1 at 20 °C preferably ranges from 60 to 120 mPas, more preferably from 80 to 110 mPa s.

[0701] In another preferred embodiment, the rotational viscosity γ1 at 20 °C preferably ranges from 60 to 200 mPas, more preferably from 80 to 180 mPa s.

[0702] The elastic constant K1 preferably ranges from 13.0 to 17.0, more preferably from 14.0 to 16.8, and in particular from 15.0 to 16.5.

[0703] The elastic constant K3 preferably ranges from 13.0 to 17.0, more preferably from 14.0 to 16.8, and in particular from 15.0 to 16.5.

[0704] According to a second preferred embodiment of the invention, the birefringence of the medium ranges from 0.105 to 0.125, more preferably from 0.107 to 0.117 and especially from 0.110 to 0.119.

[0705] The medium according to the second preferred embodiment of the invention preferably comprises:

[0706] - one or more compounds of formula IIA, preferably selected from formula IIA-2 and IIA-10, preferably with a total concentration ranging from 5% to 40%, more preferably from 7% to 35% and especially from 10% to 40%;

[0707] and / or

[0708] - one or more compounds of formula IIB and CPY, preferably formula IIB-2 and / or IIB-10 and CPY, more preferably formula IIB-2 and IIB-10 and CPY, with a total concentration ranging from 5% to 45%, more preferably from 6% to 42% and especially from 8% to 40%;

[0709] and / or

[0710] - one or more compounds of formula IIC, preferably with a total concentration ranging from 1% to 10%, more preferably from 1% to 9% and very preferably from 1% to 8%;

[0711] and / or

[0712] - one or more compounds of formula IID, preferably with a total concentration ranging from 1% to 10%, more preferably from 1.5% to 8% and very preferably from 2% to 6%;

[0713] and / or

[0714] - one or more compounds of formula III, preferably formula III-2, more preferably formula III-2-6, especially selected from B(S)-2O-O4, B(S)-2O-O5 and B(S)-2O-O6, preferably with a total concentration ranging from 1% to 12%, more preferably from 2% to 11% and very preferably from 3% to 10%;

[0715] and / or

[0716] -- one or more compounds of formula III, preferably formula III-2 and / or III-3, more preferably formula III-2-6 and / or III-3, especially one or more compounds B(S)-nO-Om and / or COB(S)-n-Om, very especially B(S)-2O-O4, B(S)-2O-O5, B(S)-2O-O6, and / or COB(S)-2-O4, preferably with a total concentration ranging from 5% to 25%, more preferably from 7% to 20% and very preferably from 10% to 18%;

[0717] and / or

[0718] - One or more compounds of formula VI-1-4, preferably in a total concentration range of 1% to 12%, more preferably 2% to 9% and very preferably 3% to 8%;

[0719] and / or

[0720] - One or more compounds of formula IIC and VI-1-4, preferably in a total concentration range of 1% to 18%, more preferably 3% to 15% and very preferably 6% to 12%;

[0721] - One or more compounds selected from the following: compounds of formula CPY, IIA, IIB, IIC, IID, III and VI-1-4, preferably in a total concentration range of 32% to 70%, more preferably 38% to 65% and very preferably 45% to 60%;

[0722] and / or

[0723] - A compound of formula I and one or more compounds of formula IV, more preferably formula I and IV-1 and IV-3, in a total concentration range of 20% to 65%, more preferably 23% to 58%, still more preferably 26% to 50% and very preferably 28% to 45%, especially 30% to 42%;

[0724] and / or

[0725] - A compound of formula I and a compound of formula IV-3-2b, preferably in a total concentration range of 5% to 40%, more preferably 8% to 35%, especially 10% to 30%;

[0726] and / or

[0727] - One or more compounds of formula IVa, more preferably formula IVa-2, especially CP-3-O2, in a total concentration range of 1% to 14%, more preferably 2% to 12%, very preferably 4% to 10%;

[0728] and / or

[0729] - One or more compounds of formula IVb, very preferably PP-n-m and / or PP-n-nVm, especially selected from PP-1-3, PP-1-4, PP-1-5, PP-1-2V and PP-1-2V1, in a total concentration range of 1% to 15%, more preferably 2% to 13%, very preferably 4% to 12%;

[0730] and / or

[0731] -One or more compounds of formula V, more preferably compounds selected from formula V-1-1 and V-1-6, especially CCC-n-m and / or CCC-n-V, very especially CCC-3-V and / or CCC-V-V, preferably in a total concentration range of 1% to 20%, more preferably 2% to 17%, very preferably 3% to 14%;

[0732] and / or

[0733] -One or more compounds of formula V, more preferably compounds selected from formula V-2-1 and V-2-2, especially CCP-n-m and / or CCP-Vn-m and / or CPP-n-m, very especially selected from CCP-3-1, CCP-V-1, CCP-V2-1 and CPP-3-2, preferably in a total concentration range of 1% to 20%, more preferably 2% to 17%, very preferably 3% to 14%;

[0734] and / or

[0735] One or more compounds of formula IIA-Y, preferably formula IIA-Y6, especially Y-nO-Om, very especially Y-4O-O4, in a total concentration range of 0.5% to 10%, more preferably 1% to 8%, and very preferably 2% to 5%;

[0736] and / or

[0737] One or more compounds of formula CL, more preferably formula CL-3, very preferably selected from the compounds CLP-V-m, CLP-V-Om, CLP-n-m, and CLP-n-Om, where n and m are independently 1, 2, 3, 4 or 5, preferably in a total concentration range of 1% to 12%, more preferably 2% to 10% and very preferably 3% to 7%,

[0738] and / or

[0739] Compounds of formula COYOIC-n-m and compounds of formula GIY-n-Om.

[0740] Furthermore, the liquid crystal medium according to the invention has a high voltage holding ratio value in the liquid crystal cell.

[0741] Generally, liquid crystal media with low addressing voltage or threshold voltage exhibit lower voltage holding ratios than those with higher addressing voltage or threshold voltage, and vice versa.

[0742] As used herein, the term "dielectric positive compound" denotes a compound having Δε > 1.5, the term "dielectric neutral compound" denotes those having -1.5 ≤ Δε ≤ 1.5 and the term "dielectric negative compound" denotes those having Δε < -1.5. Here, the dielectric anisotropy of the compound is determined by dissolving 10% of the compound in a liquid crystal host in at least one test cell and measuring the capacitance of the resulting mixture, the test cell having a layer thickness of 20 μm and homeotropic and planar surface alignments at 1 kHz in each case. The measurement voltage is generally 0.5 V - 1.0 V, but always below the capacitance threshold of the respective liquid crystal mixture under investigation.

[0743] All temperature values referred to in the present invention are given in °C.

[0744] The mixtures according to the invention are suitable for all VA-TFT applications, such as, for example, VAN, MVA, (S)-PVA, ASV, PSA (Polymer Sustained VA) and PS-VA (Polymer Stabilized VA). They are furthermore suitable for IPS (In-Plane Switching) and FFS (Fringe Field Switching) applications with negative Δε, in particular UB-FFS.

[0745] It goes without saying for a person skilled in the art that the VA, IPS or FFS mixtures according to the invention may also contain compounds in which, for example, H, N, O, Cl and F are replaced by the corresponding isotopes.

[0746] The compounds according to the invention can be synthesized by or analogously to known methods described in the literature (for example in standard works, such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart) under reaction conditions known and suitable for the said reaction. Variants known per se can also be used here, but are not mentioned here again. In particular, they can be prepared as described in the following reaction schemes or analogously to the following reaction schemes. Other methods for preparing the compounds of the invention can be obtained from the examples.

[0747] Other mesogenic compounds not explicitly mentioned above can also optionally and advantageously be used in the media according to the invention. Such compounds are known to a person skilled in the art. Detailed Description

[0748] For the present invention and in the following examples, the structures of the liquid crystal compounds are represented by abbreviations and converted into chemical formulas according to Tables A to C below. All groups C m H 2m+1 、C n H 2n+1 、and Cl H 2l+1 or C m H 2m-1 、C n H 2n-1 and C l H 2l-1 is a straight-chain alkyl group or an alkylene group, each having n, m, and l carbon atoms in each case. Preferably, n, m, and l are each independently 1, 2, 3, 4, 5, 6, or 7. Table A shows the codes for the ring elements of the compound nucleus, Table B lists the bridging units, and Table C lists the symbolic meanings of the molecular left- and right-hand end groups. The abbreviations consist of the code for the ring element with an optional linking group, followed by a first hyphen and the left-hand end group code, and a second hyphen and the right-hand end group code. Table D shows the exemplary structures of the compounds and their respective abbreviations.

[0749] Table A: Ring Elements

[0750]

[0751]

[0752]

[0753]

[0754] Table B: Bridging Units

[0755] Table C: End Groups

[0756]

[0757]

[0758] wherein n and m are each integers, and the three dots "..." are placeholders for other abbreviations from the table.

[0759] In addition to the compounds of formulae I, IIA, IIB, IIC, and / or IID, IVa, IVb, and V, the mixtures according to the invention optionally contain one or more compounds of the following compounds.

[0760] Use the following abbreviations:

[0761] (n, m, k, and l are each independently integers, preferably from 1 to 9, more preferably from 1 to 7, k and l may also be 0 and are preferably from 0 to 4, more preferably 0 or 2 and most preferably 2, n is preferably 1, 2, 3, 4, or 5, and in the combination "-nO-", it is preferably 1, 2, 3, or 4, more preferably 2 or 4, m is preferably 1, 2, 3, 4, or 5, and in the combination "-Om", it is preferably 1, 2, 3, or 4, more preferably 2 or 4. The combination "-lVm" is preferably "2V1".)

[0762] Table D

[0763]

[0764]

[0765]

[0766]

[0767]

[0768]

[0769]

[0770]

[0771]

[0772]

[0773]

[0774]

[0775]

[0776]

[0777]

[0778]

[0779]

[0780]

[0781]

[0782] Table E

[0783] Table E shows illustrative reactive mesogenic compounds that can be used in the LC media according to the present invention.

[0784]

[0785]

[0786]

[0787]

[0788]

[0789]

[0790]

[0791]

[0792]

[0793]

[0794]

[0795]

[0796]

[0797]

[0798]

[0799]

[0800]

[0801]

[0802]

[0803] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from the polymerizable compounds of formulas RM-1 to RM-182. Among these, the 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.

[0804] Examples

[0805] The present invention is illustrated in detail by the following non-limiting working examples.

[0806] The following abbreviations and symbols are used:

[0807] V0 represents the threshold voltage at 20 °C, capacitive [V],

[0808] n e represents the extraordinary refractive index at 20 °C and 589 nm,

[0809] n o represents the ordinary refractive index at 20 °C and 589 nm,

[0810] Δn represents the optical anisotropy at 20 °C and 589 nm,

[0811] ε ⊥ represents the dielectric constant perpendicular to the director at 20 °C and 1 kHz,

[0812] ε || represents the dielectric constant parallel to the director at 20 °C and 1 kHz,

[0813] Δε represents the dielectric anisotropy at 20 °C and 1 kHz,

[0814] cl.p., T(N,I) represents the clearing point [°C],

[0815] γ1 represents the rotational viscosity at 20 °C [mPa·s],

[0816] K1 represents the elastic constant, "bending" deformation at 20 °C [pN],

[0817] K2 represents the elastic constant, "twisting" deformation at 20 °C [pN],

[0818] K3 represents the elastic constant, "flexure" deformation at 20 °C [pN],

[0819] Unless otherwise explicitly stated, all concentrations in this application are expressed as weight percentages and relate to the corresponding mixtures as a whole, which include all solid or liquid crystal components and exclude solvents.

[0820] Unless otherwise explicitly stated, all temperature values indicated in this application, such as the melting point T(C,N), the transition from the smectic phase (S) to the nematic phase (N) T(S,N), and the clearing point T(N,I), are cited in degrees Celsius (°C). M.p. represents the melting point, and cl.p. = the clearing point. In addition, C = crystalline state, N = nematic phase, S = smectic phase, and I = isotropic phase. The data between these symbols represent the transition temperatures.

[0821] Unless otherwise explicitly stated, in each case, all physical properties are and have been determined in accordance with "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status Nov. 1997, Merck KGaA, Germany, and applied at a temperature of 20 °C, with △n measured at 589 nm and △ε measured at 1 kHz.

[0822] The term "threshold voltage" used in the present invention relates to the capacitive threshold (V0), which is also referred to as the Freedericks threshold, unless otherwise explicitly stated. In the examples, as usual, the optical threshold can also be cited for a relative contrast of 10% (V 10 )

[0823] Unless otherwise stated, the method for polymerizing polymerizable compounds in a PSA display 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.

[0824] Unless otherwise specified, the method for preparing test cells and measuring their electro-optical and other properties should be carried out using the method described below or a method similar thereto.

[0825] The display for measuring the capacitive threshold voltage consists of two plane-parallel glass outer plates spaced 25 μm apart, each outer plate having an electrode layer on the inside and an unrubbed polyimide alignment layer on the top, which results in a vertical alignment of the liquid crystal molecules.

[0826] A display or test cell for measuring an inclination angle consists of two plane-parallel glass outer plates spaced 4 μm apart, each of the outer plates having an electrode layer on the inner side and a polyimide alignment layer on top, wherein the two polyimide layers are rubbed antiparallel to each other and cause a vertical edge alignment of liquid crystal molecules.

[0827] By irradiating with UV light of a defined intensity for a predetermined time while applying a voltage (usually 10 V - 30 V alternating current, 1 kHz) to the display, a polymerizable compound is polymerized in the display or test cell. In the examples, unless otherwise stated, a fluorescent lamp and an intensity of 0 to 20 mW / cm 2 are used for polymerization. The intensity is measured using a standard meter (Ushio Accumulate UV meter (UV meter) with a center wavelength of 313 nm).

[0828] Transmittance measurements are carried out in a test cell with a fishbone electrode layout (from Merck Ltd., Japan; 1 pixel fishbone electrode (ITO, 10 x 10 mm, fishbone angle 47.7°, 3 μm line / 3 μm space), 3.2 μm cell gap, AF - glass, inclination angle 1°).

[0829] At a given temperature T, the storage stability (LTS 本体 ) in the bulk of the medium according to the present invention is determined by visual inspection. 2 g of the medium of interest is filled into a closed glass container (bottle) of a suitable size placed in a refrigerator at a predetermined temperature. The bottles are checked at defined time intervals for the occurrence of a smectic phase or crystallization. For each material and each temperature, two bottles are stored. If crystallization or the appearance of a smectic phase is observed in at least one of the two corresponding bottles, the test is terminated, and the time of the last check before the appearance of a higher ordered phase is recorded as the corresponding storage stability.

[0830] Mixture Examples

[0831] Mixture Examples M1 to M102 and P1 to P10 have the compositions and physical properties shown in the following table:

[0832] Mixture Example M1

[0833]

[0834] Medium M1 contains compound CCG - V - F. This mixture is characterized in that "flickering" in the FFS panel is improved, thus enabling a more energy - efficient panel as the addressing frequency can be reduced.

[0835] Mixture Example M2

[0836]

[0837]

[0838] Mixture Example M3

[0839]

[0840] Mixture Example M4

[0841]

[0842] Mixture Example M5

[0843]

[0844]

[0845] Mixture Example M6

[0846]

[0847] Mixture Example M7

[0848]

[0849]

[0850] Mixture Example M8

[0851]

[0852] Mixture Example M9

[0853]

[0854]

[0855] Mixture Example M10

[0856]

[0857] Mixture Example M11

[0858]

[0859] Mixture Example M12

[0860]

[0861]

[0862] Mixture Example M13

[0863]

[0864] Mixture Example M14

[0865]

[0866]

[0867] Mixture Example M15

[0868]

[0869] Mixture Example M16

[0870]

[0871]

[0872] Mixture Example M17

[0873]

[0874] Mixture Example M18

[0875]

[0876]

[0877] Mixture Example M19

[0878]

[0879] Mixture Example M20

[0880]

[0881] Mixture Example M21

[0882]

[0883] Mixture Example M22

[0884]

[0885] Mixture Example M23

[0886]

[0887] Mixture Example M24

[0888]

[0889] Mixture Example M25

[0890]

[0891]

[0892] Mixture Example M26

[0893]

[0894] Mixture Example M27

[0895]

[0896]

[0897] Mixture Example M28

[0898]

[0899] Mixture Example M29

[0900]

[0901] Mixture Example M30

[0902]

[0903] Mixture Example M31

[0904]

[0905]

[0906] Mixture Example M32

[0907]

[0908] Mixture Example M33

[0909]

[0910] Mixture Example M34

[0911]

[0912]

[0913] Mixture Example M35

[0914]

[0915] Mixture Example M36

[0916]

[0917]

[0918] Mixture Example M37

[0919]

[0920] Mixture Example M38

[0921]

[0922]

[0923] Mixture Example M39

[0924]

[0925] Mixture Example M40

[0926]

[0927]

[0928] Mixture Example M41

[0929]

[0930] Mixture Example M42

[0931]

[0932]

[0933] Mixture Example M43

[0934]

[0935] Mixture Example M44

[0936]

[0937]

[0938] Mixture Example M45

[0939]

[0940] Mixture Example M46

[0941]

[0942]

[0943] Mixture Example M47

[0944]

[0945] Mixture Example M48

[0946]

[0947]

[0948] Mixture Example M49

[0949]

[0950] Mixture Example M49

[0951]

[0952]

[0953] Mixture Example M50

[0954]

[0955] Mixture Example M51

[0956]

[0957] Mixture Example M52

[0958] Mixture Example M52 consists of 99.985% of Mixture Example M1 and 0.015% of the compound of formula S1-1a

[0959]

[0960] Mixture Example M53

[0961] Mixture Example M53 consists of 99.98% of Mixture Example M2 and 0.02% of the compound of formula S2-1a

[0962]

[0963] Mixture Example M54

[0964]

[0965] Mixture Example M55

[0966]

[0967] Mixture Example M56

[0968]

[0969]

[0970] Mixture Example M57

[0971]

[0972] Mixture Example M58

[0973]

[0974]

[0975] Mixture Example M59

[0976]

[0977] Mixture Example M60

[0978]

[0979]

[0980] Mixture Example M61

[0981]

[0982]

[0983] Mixture Example M62

[0984]

[0985] Mixture Example M63

[0986]

[0987]

[0988] Mixture Example M64

[0989]

[0990] Mixture Example M65

[0991]

[0992]

[0993] Mixture Example M66

[0994]

[0995]

[0996] Mixture Example M67

[0997]

[0998] Mixture Example M68

[0999]

[1000] Mixture Example M69

[1001]

[1002]

[1003] Mixture Example M70

[1004]

[1005] Mixture Example M71

[1006]

[1007] Mixture Example M72

[1008]

[1009]

[1010] Mixture Example M73

[1011]

[1012] Mixture Example M74

[1013] Mixture Example M74 consists of 99.98% of Mixture Example M1 and 0.02% of Compound ST-12b-1

[1014]

[1015] Mixture Example M75

[1016]

[1017]

[1018] Mixture Example M76

[1019]

[1020] Mixture Example M77

[1021]

[1022] Mixture Example M78

[1023]

[1024]

[1025] Mixture Example M79

[1026]

[1027] Mixture Example M80

[1028]

[1029]

[1030] Mixture Example M81

[1031] Mixture Example M81 consists of 99.975% of the medium of Mixture Example M79 and 0.025% of Compound ST-3c:

[1032]

[1033] Mixture Example M82

[1034] Mixture Example M82 consists of 99.980% of the medium of Mixture Example M78 and 0.020% of Compound ST-3d:

[1035]

[1036] Mixture Example M83

[1037]

[1038]

[1039] Mixture Example M84

[1040]

[1041] Mixture Example M85

[1042]

[1043]

[1044] Mixture Example M86

[1045]

[1046] Mixture Example M87

[1047]

[1048]

[1049] Mixture Example M88

[1050]

[1051] Mixture Example M89

[1052]

[1053] Mixture Example M90

[1054]

[1055]

[1056] Mixture Example M91

[1057]

[1058] Mixture Example M92

[1059]

[1060]

[1061] Mixture Example M93

[1062]

[1063] Mixture Example M94

[1064]

[1065]

[1066] Mixture Example M95

[1067]

[1068] Mixture Example M96

[1069]

[1070]

[1071] Mixture Example M97

[1072]

[1073] Mixture Example M98

[1074]

[1075] Mixture Example M99

[1076]

[1077] Mixture Example M100

[1078]

[1079] Mixture Example M101

[1080]

[1081]

[1082] Mixture Example M102

[1083]

[1084] Polymerizable mixture

[1085] The polymerizable mixtures P1 to P9 are prepared from the nematic mixtures given in Table 1 by adding a reactive mesogen (RM) selected from the group of compounds of the formulae RM-1, RM-17, RM-35, RM-64 and RM-171 in the amounts (% RM) given in Table 1.

[1086]

[1087]

[1088] Table 1: Polymerizable Mixture

[1089]

[1090]

[1091] Mixture Example P10

[1092] The polymerizable mixture P10 consists of 99.434% of the mixture Example M1, 0.300% of RM-1, 0.200% of RM-145, 0.050% of RM-163, 0.001% of 1076 and 0.015% of the compound ST-3a-1.

[1093]

Claims

1. A liquid crystal medium comprising a compound of formula I and Compounds of formula CPY and One or more compounds selected from the group consisting of compounds of formula IIA, IIB, IIC and IID in R 2A , R 2B , R 2C and R 2D Identically or differently, denote H, a straight-chain alkyl or alkoxy radical having 1 to 15 C atoms, a straight-chain alkenyl or alkenyloxy radical having 2 to 15 C atoms or a branched alkyl, alkoxy, alkenyl, alkenyloxy radical each having 3 to 15 C atoms, wherein one or more CH2 radicals in these radicals may each independently of one another be -CH=CH-, -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO- is substituted in such a way that the O atoms are not directly connected to each other, and wherein one or more H atoms may be replaced by halogen, L 1 and L 2 , each independently represents F, Cl, CF3 or CHF2, Y represents H, F, Cl, CF3, CHF2 or CH3, Z 2 , Z 2B and Z 2D Each independently represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF- or -CH=CHCH2O-, (O) represents O or a single bond, p represents 0, 1 or 2, q represents 0 or 1, and v represents an integer from 1 to 6, Compounds of the formula CPY are excluded from Formula IIB.

2. A liquid crystal medium according to claim 1, wherein the medium comprises one or more compounds selected from the group consisting of compounds of formula III, BC, CR, PH-1 and PH-2 in R 31 , R 32 , R B1 , R B2 , R CR1 , R CR2 , R P1 , and R P2 each independently of one another represents H, alkyl or alkoxy having 1 to 15 C atoms, wherein one or more CH2 groups in these radicals can each independently of one another be -CH=CH-, -C≡C-, -CF2O-, -OCF2-, -O-, -CO-O- or -O-CO- is substituted in such a way that the O atoms are not directly connected to each other, and wherein one or more H atoms may be replaced by halogen, A 31 In each occurrence, they are expressed independently of each other a) 1,4-cyclohexylene or 1,4-cyclohexenylene, in which one or two non-adjacent CH2 groups may be replaced by -O- or -S-, b) 1,4-phenylene, in which one or both CH groups may be replaced by N, or c) a radical selected from the group consisting of spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octane-2,6-diyl, 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, where the radicals a), b) and c) may be mono- or polysubstituted by halogen atoms, n represents 0, 1 or 2, Z 31 represents, independently of one another, at each occurrence -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond, L 31 and L 32 each independently represents F, Cl, CF3 or CHF2, W means O or S, and c is 0, 1 or 2.

3. A liquid crystal medium according to claim 1 or 2, wherein the medium comprises one or more compounds of formula VI in R 61 and R 62 represents H, F, straight-chain alkyl or alkoxy having 1 to 15 C atoms, straight-chain alkenyl or alkenyloxy having 2 to 15 C atoms or branched alkyl, alkoxy, alkenyl, alkenyloxy each having 3 to 15 C atoms, wherein one or more CH2 groups in these radicals may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- are substituted in such a way that the O atoms are not directly connected to each other, and wherein one or more H atoms may be replaced by halogen, X 61 To X 66 , identically or differently, represent H or F, and Z 61 and Z 62 , identically or differently, represent CH2CH2 or a single bond.

4. Liquid-crystalline medium according to one or more of claims 1 to 3, wherein the medium comprises one or more compounds of the formula VIII in R 81 and R 82 , identically or differently, represent H, F, straight-chain alkyl or alkoxy having 1 to 15 C atoms, straight-chain alkenyl or alkenyloxy having 2 to 15 C atoms or branched alkyl, alkoxy, alkenyl or alkenyloxy having 3 to 15 C atoms, wherein one or more CH2 groups in these radicals may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, replaced by -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly attached to each other, and wherein one or more H atoms may be replaced by halogen; A 0 , A 81 , and A 82 , each independently of one another denotes phenylene-1,4-diyl, in which one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, CF3, OCH3, OCHF2 or OCF3, cyclohexane-1,4-diyl, in which one or two non-adjacent CH2 groups may be replaced independently of one another by O and / or S and one or more H atoms may be replaced by F, cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl; Z 81 and Z 82 , each independently represents -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2H4-, -C2F4, -CF2CH2-, -CH2CF2-, -CFHCFH-, -CFHCH2-, -CH2CFH-, -CF2CFH-, -CFHCF2-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or a single bond; n represents 0, 1, 2 or 3; and m represents 0, 1, 2 or 3.

5. Liquid-crystalline medium according to one or more of claims 1 to 4, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae Z-1 to Z-8: in R Z Having R in claim 1 2A Meaning, (O) represents O or a single bond, and Alkyl represents an alkyl group having 1 to 7 C atoms.

6. Liquid-crystalline medium according to one or more of claims 1 to 5, wherein the medium comprises one or more compounds of the formula IV in R 41 represents an alkyl group having 1 to 7 C atoms or an alkenyl group having 2 to 7 C atoms, R 42 represents an alkyl group having 1 to 7 C atoms or an alkoxy group having 1 to 6 C atoms or an alkenyl group having 2 to 7 C atoms, The compounds of formula I according to claim 1 are excluded.

7. Liquid-crystalline medium according to one or more of claims 1 to 6, wherein the medium comprises one or more compounds of the formulae IVb-1 to IVb-3 in Alkyl and alkyl* each independently represent a straight-chain alkyl radical having 1 to 6 C atoms, and Alkenyl and alkenyl* each independently of one another represent straight-chain alkenyl having 2 to 6 C atoms.

8. Liquid-crystalline medium according to one or more of claims 1 to 7, wherein the medium comprises one or more compounds of the formula V in R 51 , R 52 represents an alkyl group having 1 to 7 C atoms, an alkoxy group having 1 to 7 C atoms, or an alkoxyalkyl group, an alkenyl group or an alkenyloxy group having 2 to 7 C atoms, Same or different, indicating Z 51 and Z 52 , identically or differently, represent -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO- or a single bond, and n is 1 or 2.

9. Liquid-crystalline medium according to one or more of claims 1 to 8, wherein the medium comprises one or more compounds selected from the group consisting of compounds of the formulae V-1, V-2 and V-3: The radicals occurring therein have the meanings given in claim 8.

10. Liquid-crystalline medium according to one or more of claims 1 to 9, wherein the medium according to the invention comprises one or more compounds of the formula CL in R L represents H, a straight-chain or branched alkyl or alkoxy radical having 1 to 15 C atoms, or a straight-chain or branched alkenyl radical having 2 to 15 C atoms, wherein one or more CH2 radicals in these radicals may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- are substituted in such a way that the O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by halogen, X L represents F, Cl, CN, CHF2, CF3, OCF3, or the same or different, having R L One of the meanings of Y L Represents H, F, Cl or CH3.

11. Liquid-crystalline medium according to one or more of claims 1 to 10, wherein the medium comprises one or more compounds of the formula X in R X denotes a straight-chain or branched alkyl or alkoxy radical having 1 to 15 C atoms, wherein one or more CH2 groups in these radicals may each independently of one another be -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- are substituted in such a way that the O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms may be replaced by halogen, express express X X represents F, Cl, CN, a haloalkyl or haloalkoxy group each having 1 to 6 C atoms or a haloalkenyl or haloalkenyloxy group each having 2 to 6 C atoms, Z X It represents -C2H4-, -CH2O-, CF2O, -CH=CH- or a single bond.

12. Liquid-crystalline medium according to one or more of claims 1 to 11, wherein the medium comprises one or more compounds of the formula S in Ar represents a methylene group or an aromatic hydrocarbon group having 6 to 40 C atoms or a heteroaromatic hydrocarbon group having 4 to 40 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 Indicates -O-, -C(O)O-, -(CH2) z -or-(CH2) z O-, or single bond; HA means R H Indicates H, O · , CH3, OH or OR S ; R S1 , R S2 , R S3 and R S4 , identically or differently, represent an alkyl group having 1 to 6 C atoms; G stands for H or R S or group Z S -HA; z is an integer from 1 to 6; and q is 2, 3 or 4.

13. Liquid-crystalline medium according to one or more of claims 1 to 12, wherein the medium comprises polymerizable compounds.

14. A liquid crystal display comprising a liquid crystal medium according to any one of claims 1 to 13.

15. The liquid crystal display of claim 14, wherein the display is a VA, IPS, FFS, PS-VA, PS-IPS or PS-FFS type display.

16. Use of the liquid-crystalline medium according to one or more of claims 1 to 13 in VA, IPS, FFS, PS-VA, PS-IPS or PS-FFS displays.

17. Energy-saving display for gaming, comprising a liquid-crystalline medium according to one or more of claims 1 to 13.

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