Liquid-crystal medium

Abstract

To provide a liquid-crystal medium.SOLUTION: The present invention relates to a liquid-crystal (LC) material as defined in claim 1, having 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.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to liquid crystal (LC) media with negative dielectric anisotropy and to their use for optical, electro-optical and electronic purposes, in particular in LC displays. [Background technology]

[0002] One of the liquid-crystal display (LCD) modes currently in use is the TN ("twisted nematic") mode. However, TN LCDs have the disadvantage that their contrast is strongly dependent on the viewing angle.

[0003] In addition, so-called VA ("vertically aligned") displays are known which have wider viewing angles. The LC cell of a VA display comprises a layer of an LC medium between two transparent electrodes, where the LC medium usually has a negative dielectric anisotropy. In the switched-off state the molecules of the LC layer are aligned perpendicular to the electrode surfaces (homeotropic) or have a tilted homeotropic alignment. Upon application of a voltage to the two electrodes a reorientation of the LC molecules occurs parallel to the electrode surfaces.

[0004] Also known are so-called IPS ("in-plane switching") displays which have an LC layer between two substrates, in which two electrodes are arranged on only one of the two substrates, preferably with an interdigitated comb-like structure. When a voltage is applied to the electrodes, this creates an electric field between the electrodes which has a significant component parallel to the LC layer. This leads to a reorientation of the LC molecules in the layer plane.

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

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

[0007] Further disclosed are FFS displays with electrode designs and layer thicknesses similar to those of FFS displays, but with LC medium layers with negative dielectric anisotropy instead of LC medium layers with positive dielectric anisotropy (see, for example, S.H. Lee et al., Appl. Phys. Lett. vol. 73 (no. 20), 1998, pp. 2882-2883 (Non-Patent Document 2) and S.H. Lee et al., Liquid Crystals vol. 39 (no. 9), 2012, pp. 1141-1148 (Non-Patent Document 3)). LC media with negative dielectric anisotropy exhibit a more favorable director alignment with less tilt and a higher twist alignment than LC media with positive dielectric anisotropy, and as a result these displays have higher transparency. The displays further comprise an alignment layer, preferably a polyimide alignment layer provided on at least one of the substrates, which is in contact with the LC medium and induces a planar alignment of the LC molecules of the LC medium. These displays are also known as "Ultra Brightness FFS" mode displays. These displays require a highly reliable LC medium.

[0008] In more recent types of VA displays, the uniform alignment of the LC molecules is restricted to relatively small domains within the LC cell. Disclinations may exist between these domains, also known as tilt domains. VA displays with tilt domains have larger contrast-independent viewing angles and grey levels compared to conventional VA displays. In addition, this type of display is easier to manufacture, and further treatment of the electrode surface, for example by rubbing, to achieve a uniform alignment of the molecules in the switched-on state is no longer necessary. Instead, the preferred direction of the tilt or pretilt angle is controlled by a special design of the electrodes.

[0009] In so-called MVA ("multidomain vertical alignment") displays, this is usually achieved by electrodes with protrusions, which cause a local pretilt. As a result, the LC molecules are aligned parallel to the electrode surface in different directions and in different defined areas of the cell when a voltage is applied. This achieves a "controlled" switch and prevents the formation of interfering disclination lines. This arrangement improves the viewing angle of the display, but results in a lower transparency to light. A further development of MVA uses protrusions only on one electrode side, while the opposite electrode has slits, which improves the transparency to light. The slit electrodes generate a non-uniform electric field in the LC cell when a voltage is applied, which means that controlled switching is still achieved. To further improve the transparency to light, the distance between the slits and the protrusions can be increased, but this in turn results in a longer response time. In so-called PVA ("patterned VA") displays, the protrusions are fully redundant in that both electrodes are structured with slits on the opposite side, which results in increased contrast and improved transmission to light, but is technically difficult and makes the display more sensitive to mechanical influences (such as "tapping"). However, for many applications, such as monitors and especially television screens, shorter response times and improvements in the contrast and brightness (transmission) of the displays are required.

[0010] Further developments are the so-called PS ("polymer sustained") or PSA ("polymer sustained alignment") type displays, for which the term "polymer stabilised" is sometimes also used. In these displays, small amounts (e.g. 0.3% by weight, typically less than 1% by mass) of one or more polymerisable compound(s), preferably polymerisable monomeric compound(s), are added to the LC medium and polymerised or crosslinked in situ after filling the LC medium into the display, usually by UV photopolymerisation, optionally with the application of a voltage to the electrodes of the display. The polymerisation is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, usually at room temperature. The addition of polymerisable mesogens or liquid crystal compounds, also known as reactive mesogens or "RMs", to the LC mixture has proven to be particularly suitable.

[0011] On the other hand, the PS(A) principle is 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. Polymerization of the RM is preferably carried out with applied voltage in the case of PS-VA and PS-OCB displays, and with or without applied voltage, preferably without applied charge, in the case of PS-IPS displays. As can be demonstrated in test cells, the PS(A) method results in a pretilt in the cell. In the case of PS-VA displays, the pretilt has a positive effect on the response time. For PS-VA displays, standard MVA or PVA pixel and electrode layouts can be used. In addition, however, it is also possible to make do without protrusions, for example with only one structured electrode side, which significantly simplifies the production and at the same time results in a very good contrast and at the same time a very good transparency for light.

[0012] PS-VA displays are described, for example, in EP 1170626 (Patent Document 1), U.S. Patent No. 6,861,107 (Patent Document 2), U.S. Patent No. 7,169,449 (Patent Document 3), U.S. Patent Application Publication No. 2004 / 0191428 (Patent Document 4), U.S. Patent Application Publication No. 2006 / 0066793 (Patent Document 5) and U.S. Patent Application Publication No. 2006 / 0103804 (Patent Document 6). PS-OCB displays are described, for example, in T.-J-Chen et al., Jpn.J.Appl.Phys., Vol. 45, 2006, pp. 2702-2704 (Non-Patent Document 4) and SH Kim, L.-C-Chien, Jpn.J.Appl.Phys., Vol. 43, 2004, pp. 7643-7647 (Non-Patent Document 5). PS-IPS displays are described, for example, in U.S. Patent No. 6,177,972 (Patent Document 7) and Appl. Phys. Lett. 1999, Vol. 75 (No. 21), p. 3264 (Non-Patent Document 6). PS-TN displays are described, for example, in Optics Express 2004, Vol. 12 (No. 7), p. 1221 (Non-Patent Document 7).

[0013] PSA displays typically have an alignment layer on one or both of the substrates forming the display cell below the layer formed by the phase separated and polymerized RM inducing the pretilt angle mentioned above, which provides an initial alignment of the LC molecules before the polymer stabilization step. The alignment layer is usually applied on top of an electrode (if such an electrode is present) so as to be in contact with the LC medium and induce an initial alignment of the LC molecules. The alignment layer may for example comprise or consist of polyimide and may be rubbed or prepared by photoalignment methods.

[0014] Like the conventional LC displays described above, PSA displays can be operated as active matrix displays or passive matrix displays. In the case of active matrix displays, the individual pixels are typically addressed by integrated nonlinear active elements, such as transistors (e.g. thin film transistors ("TFTs")), whereas in the case of passive matrix displays, the individual pixels are typically addressed by multiplexing methods as known from the prior art.

[0015] Especially for monitor and especially television applications, there is a continuing demand for optimization of the response time but also the contrast and brightness (and therefore also the transmission) of LC displays. Here, the PSA method can offer significant advantages: especially for PS-VA, PS-IPS and PS-FFS displays, a reduction in the response time, which correlates with the pretilt measurable in test cells, can be achieved without significant adverse effects on other parameters.

[0016] Another problem observed in the prior art is that the use of conventional LC media in LC displays, including but not limited to PSA type displays, often results in mura in the display, especially when the LC media is filled into display cells manufactured using the one drop filling (ODF) method. This phenomenon is also known as "ODF mura". It is therefore desirable to provide an LC medium that leads to reduced ODF mura.

[0017] Another problem observed in the prior art is that LC media for use in PSA displays, including but not limited to PSA type displays, often exhibit high viscosity and, as a result, high switching times. To reduce the viscosity and switching time of the LC medium, it has been suggested in the prior art to add LC compounds with alkenyl groups. However, it has been observed that LC media containing alkenyl compounds often exhibit reduced reliability and stability as well as reduced VHR, especially after exposure to UV radiation. In particular, since the photopolymerization of RM in PSA displays is usually carried out by exposure to UV radiation, this can cause a reduction in the VHR in the LC medium, which is quite disadvantageous for use in PSA displays.

[0018] In addition, there is a great demand for PSA displays, and LC media and polymerizable compounds for use in such PSA displays, which enable a large operating temperature range as well as high resistivity, short response times even at low temperatures, and low threshold voltages, low pretilt angles, a large number of grey levels, high contrast and wide viewing angles, high reliability and high values ​​for VHR after UV exposure, and in the case of polymerizable compounds, low melting points and high solubility in LC host mixtures. For PSA displays for mobile applications, it is particularly desirable to have available LC media exhibiting low threshold voltages and high birefringence.

[0019] One of the trends in displays is to achieve the fastest possible response time to obtain the best video quality. In this respect, media with negative dielectric anisotropy are inherently at a disadvantage compared to LC media with positive dielectric anisotropy. On the other hand, mixtures with negative dielectric anisotropy allow higher transmittance in standard FFS cell layouts, and therefore their use has a positive impact on power consumption and the environment. In the art, there is a need to achieve both fast response times and high transmittance. For use in mobile devices in particular, displays with high transmittance are required, which allows the use of lower intensity backlights, thus leading to longer battery life and thus more sustainable products. Alternatively, displays with improved contrast, especially under ambient light, and higher brightness can be achieved. Also, the popularity of 8K and gaming monitors leads to an increased demand for LC display panels with higher refresh rates and therefore LC media with faster response times. [Prior art documents] [Patent documents]

[0020] [Patent Document 1] European Patent Application Publication No. 1170626 [Patent Document 2] U.S. Patent No. 6,861,107 [Patent Document 3] U.S. Patent No. 7,169,449 [Patent Document 4] US Patent Application Publication No. 2004 / 0191428 [Patent Document 5] US Patent Application Publication No. 2006 / 0066793 [Patent Document 6] US Patent Application Publication No. 2006 / 0103804 [Patent Document 7] U.S. Patent No. 6,177,972 [Non-patent literature]

[0021] [Non-Patent Document 1] SHJung et al., Jpn.J.Appl.Phys., Volume 43, No. 3, 2004, Page 1028 [Non-Patent Document 2] SHLee et al., Appl. Phys. Lett. Vol. 73 (No. 20), 1998, pp. 2882-2883 [Non-Patent Document 3] SHLee et al., Liquid Crystals Volume 39 (No. 9), 2012, pp. 1141-1148 [Non-Patent Document 4] T.-J-Chen et al., Jpn.J.Appl.Phys. Vol. 45, 2006, pp. 2702-2704 [Non-Patent Document 5] SHKim, L.-C-Chien, Jpn.J.Appl.Phys. Volume 43, 2004, pp. 7643-7647 [Non-Patent Document 6] Appl.Phys.Lett.1999, Volume 75 (No. 21), Page 3264 [Non-Patent Document 7] Optics Express 2004, Volume 12 (No. 7), Page 1221 Summary of the Invention [Problem to be solved by the invention]

[0022] There is therefore still a great demand for VA, FFS or PSA displays and LC media, optionally comprising polymerizable compounds, for use in VA, FFS or PSA displays which do not exhibit the above-mentioned disadvantages or exhibit them to a lesser extent and which have improved properties.

[0023] The present invention is based on the object of providing new suitable LC media which do not have the disadvantages indicated above or have them to a reduced extent. [Means for solving the problem]

[0024] Surprisingly, it has been found that by using liquid-crystalline media comprising one or more compounds of formula I as defined below, liquid-crystalline media can be realized which do not exhibit the disadvantages of the prior art materials or at least exhibit them to a significantly lesser extent and which have a suitably high negative Δε, a suitable phase range and Δn as well as a high LTS.

[0025] The invention relates to a liquid-crystalline medium comprising a) one or more compounds of the formula I and b) one or more compounds selected from the group of the compounds of the formulae IIA, IIB, IIC and IID.

[0026] [ka]

[0027] During the ceremony, R 1 and R 2 are the same or different and represent H, halogen, CN, SCN, linear alkyl or alkoxy having 1 to 15 C atoms, linear alkenyl or alkenyloxy having 2 to 15 C atoms, or branched alkyl, alkoxy, alkenyl or alkenyloxy having 3 to 15 C atoms, with the proviso that one or more CH2 groups in these groups are not directly linked to O atoms, [ka] each independently being replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in which one or more H atoms may be replaced by halogen; A 0 , A 1 and A 2each independently of the other represents 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 the other 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 1 and Z 2 each independently represents -CF2O-, -OCF2-, -CHO-, -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, preferably 0, 1 or 2, very preferably 0 or 1, particularly preferably 0; and m represents 0, 1, 2 or 3, preferably 0, 1 or 2, very preferably 1 or 2 and in particular 1. [ka]

[0028] During the ceremony, R 2A , R 2B , R 2C and R 2Dare the same or different and represent H, linear alkyl or alkoxy having 1 to 15 C atoms, linear alkenyl or alkenyloxy having 2 to 15 C atoms, or branched alkyl, alkoxy, alkenyl or alkenyloxy having 3 to 15 C atoms, provided that one or more CH2 groups in these groups are not directly linked to O atoms, [ka] each independently being replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in which one or more H atoms may be replaced by halogen; L 1 , L 2 , L 3 and L 4 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, -CHCH-, -CH=CH-, -CFO-, -OCF-, -CHO-, -OCH-, -COO-, -OCO-, -CF-, -CF=CF- or -CH=CHCHO-; p represents 0, 1 or 2; q represents 0 or 1, and v represents an integer of 1 to 6.

[0029] Compounds of formula I are known, for example, from WO 2010 / 099853 and DE 10 2010 027 099 A1.

[0030] The present invention further relates to a method for preparing an LC medium as described above and below, comprising the step of mixing one or more compounds of formula I with one or more compounds of formulae IIA, IIB, IIC and / or IID, optionally with one or more chiral dopants, optionally with one or more polymerizable compounds and optionally further LC compounds and / or additives.

[0031] The invention furthermore relates to the use of an LC medium according to the invention for electro-optical purposes, preferably in displays, very preferably of the VA, IPS or FFS type, in particular of the UB-FFS type.

[0032] The present invention furthermore particularly relates to the use of the LC medium according to the invention in PSA displays, preferably in PSA displays comprising an LC medium for the generation of a tilt angle in the LC medium by in situ polymerization of a polymerizable reactive mesogen (RM, reactive mesogen) in an electric or magnetic field in the PSA display.

[0033] The invention furthermore 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.

[0034] The invention further 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.

[0035] According to another aspect of the present invention there is provided an energy-saving display 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 of 0.125 to 0.155.

[0036] The invention further relates to a method for producing an LC display as described above and below, comprising the steps of filling or otherwise providing between the substrates of the display an LC medium, optionally comprising one or more polymerisable compounds as described above and below, and optionally polymerising the polymerisable compounds.

[0037] The LC media according to the invention, in particular when used in UB-FFS displays, exhibit the following advantageous properties: -Excellent low-temperature stability (LTS), -Improved contrast ratio of the display, -High transparency of the display, High clearing temperature, -High voltage holding ratio, -Low rotational viscosity, -Fast switch, Fast response times enabling low power LCDs that extend battery life for mobile devices - sufficient stability against heat and / or UV, especially when used outdoors, Suitably high birefringence combined with fast response time for use in gaming applications. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] A 0 Preference is given to LC media comprising compounds of formula I, in which R represents phenylene-1,4-diyl, in which one or two CH groups may be replaced by N and in which one or more H atoms may be replaced by halogen, CN, CH3, CHF2, CH2F, OCH3, OCHF2, CF3 or OCF3.

[0039] A 0 but [ka] Particularly preferred are compounds which represent:

[0040] Very particularly preferably A0 teeth [ka] Represents.

[0041] A in Formula I 1 and A 2 preferably denotes phenylene-1,4-diyl (which radicals may also be mono- or polysubstituted by F), furthermore cyclohexane-1,4-diyl, cyclohexenylene-1,4-diyl, tetrahydropyran-2,5-diyl or 1,3-dioxane-2,5-diyl, very preferably phenylene-1,4-diyl (which radicals may also be mono- or polysubstituted by F) or cyclohexane-1,4-diyl.

[0042] Z in Formula I 1 and Z 2 preferably represents -CF2O-, -OCF2- or a single bond, very preferably a single bond.

[0043] A in Formula I 1 and A 2 is particularly preferably [ka] where L represents halogen, CF3 or CN, preferably F.

[0044] R 1 and R 2 Further preferred are compounds of formula I, in which each independently of one another denotes H, F or alkyl, alkoxy, alkenyl or alkynyl having 1 to 8, preferably 1 to 5, C atoms, each of which may be replaced by halogen, in particular F.

[0045] R 1 and R 2preferably represents H, optionally fluorinated alkyl or alkoxy having 1 to 7 C atoms, optionally fluorinated alkenyl or alkynyl having 2 to 7 C atoms, optionally fluorinated cycloalkyl having 3 to 12 C atoms.

[0046] Preferably R 1 and R 2 At least one of them is not H, and particularly preferably R 1 and R 2 Both of these are not H. 1 is very particularly preferably alkyl. 2 is more preferably H, alkyl or fluorine. Very particularly preferably R 1 is alkyl, R 2 is H or alkyl. R 1 , R 2 R each independently of one another very particularly preferably denotes unbranched alkyl having 1 to 5 C atoms. 1 and R 2 When R represents a substituted alkyl, alkoxy, alkenyl or alkynyl, two groups R 1 and R 2 The total number of C atoms in is preferably less than 10.

[0047] Preferred compounds of formula I are selected from the following subformulae, more preferably from the compounds of formula I-3:

[0048] [ka]

[0049] In the formula, R 1 and R 2 has the meaning given above, 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 1 and R 2 stands in particular independently for n-alkyl having 1 to 5 C atoms.

[0050] In a first very preferred embodiment the compounds of the formulae I-1 to I-6 are selected from the compounds of the formulae I-1a to I-6a, in particular of the formula I-3a.

[0051] [ka]

[0052] In the formula, R 1 , R 2 , r and s have the meanings defined above.

[0053] In a second very preferred embodiment the compounds of formulae I-1 to I-6 are selected from the compounds of formulae I-1b to I-6b, in particular of formula I3-b.

[0054] [ka]

[0055] In the formula, R 1 , R 2 , r and s have the meanings defined above.

[0056] In a second very preferred embodiment the compounds of formulae I-1 to I-6 are selected from the compounds of formulae I-1c to I-6c, in particular of formula I3-c.

[0057] [ka]

[0058] In the formula, R 1 , R 2 , r and s have the meanings defined above.

[0059] In a fourth very preferred embodiment the compounds of the formulae I-1 to I-6 are selected from the compounds of the formulae I-1d to I-6d, in particular of the formula I-3d.

[0060] [ka]

[0061] In the formula, R 1 , R 2 , r and s have the meanings defined above.

[0062] In a particularly preferred embodiment, the medium according to the invention comprises one or more compounds selected from the group of formulae I-1a to I-6a and one or more compounds selected from the group of formulae I-1b to I-6b.

[0063] Very particularly preferably, the medium comprises one or more compounds selected from the group of the compounds of the formulae I-3a, I-3b, I-3c and I-3d.

[0064] [ka]

[0065] In the formula, R 1 , R 2 , L and r have the meanings defined above, and preferably r is 0.

[0066] In addition, particular preference is given to LC media which comprise a compound of formula I below:

[0067] [ka]

[0068] [ka]

[0069] The most preferred compounds of formula I especially include one or more of the following:

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] Alternatively or additionally, a compound of formula I below may be used:

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] Preferred compounds of formula IIA, IIB, IIC and IID are shown below.

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] In the formula, the parameter a represents 1 or 2, and alkyl and alkyl *each independently represents a linear alkyl group having 1 to 6 C atoms, alkenyl represents a linear alkenyl group having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond. 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-.

[0092] Highly preferred compounds of formula IID are selected from the following subformulae:

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] In a preferred embodiment, the medium comprises one or more compounds of formula IID-10a.

[0100] [ka]

[0101] in which the occurring groups and parameters have the meanings given above under formula IID, and R 2 teeth, [ka] wherein r is 0, 1, 2, 3, 4, 5 or 6; and s is 1, 2 or 3.

[0102] Preferred compounds of formula IID-10a are compounds IID-10a-1 to IID-10a-14.

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] 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.

[0107] A preferred medium according to the invention comprises at least one compound of formula IIC-1.

[0108] [ka]

[0109] In the formula, alkyl and alkyl* has the meaning given above.

[0110] In particular, the medium comprises one or more compounds of formula IIA-2 selected from the following subformulae:

[0111] [ka]

[0112] Alternatively and preferably, in addition to the compounds of formulae IIA-2-1 to IIA-2-5, the medium comprises one or more compounds of formulae IIA-2a-1 to IIA-2a-5.

[0113] [ka]

[0114] In particular, the medium comprises one or more compounds of formula IIA-10 selected from the following subformulae:

[0115] [ka]

[0116] Alternatively and preferably, in addition to the compounds of formulae IIA-10-1 to IIA-10-5, the medium comprises one or more compounds of formulae IIA-10a-1 to IIA-10a-5.

[0117] [ka]

[0118] In particular, the medium comprises one or more compounds of formula IIB-10 selected from the following subformulae:

[0119] [ka]

[0120] Alternatively and preferably, in addition to the compounds of formulae IIB-10-1 to IIB-10-5, the medium comprises one or more compounds of formulae IIB-10a-1 to IIB-10a-5.

[0121] [ka]

[0122] The medium according to the invention preferably comprises one or more compounds of formula III.

[0123] [ka]

[0124] During the ceremony, R 31 and R 32 each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, with the proviso that one or more CH2 groups in these groups are not directly linked to O atoms, [ka] each independently being replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, in which one or more H atoms may be replaced by halogen; A 31 are, independently of each other in each occurrence, a) a 1,4-cyclohexenylene or 1,4-cyclohexylene group, in which one or two non-adjacent CH groups may be replaced by -O- or -S-; b) a 1,4-phenylene group, in which one or two CH groups may be replaced by N, or c) radicals from the group 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. represents with the proviso that groups a), b) and c) may be mono- or polysubstituted by halogen atoms; n represents 0, 1 or 2, preferably 0 or 1; Z 31 represent, independently in each occurrence, -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CHO-, -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 L 31 and L 32 each independently of the other represents F, Cl, CF or CHF, preferably H or F, most preferably F, and W represents O or S.

[0125] The compound of formula III is preferably selected from the compounds of formula III-1 and / or III-2.

[0126] [ka]

[0127] in which the occurring radicals have the same meaning as given above in formula III, preferably R 31 and R 32 are each independently an alkyl, alkenyl or alkoxy group having up to 15 C atoms, more preferably one or both of them represent an alkoxy group, L 11 and L 12each preferably represents F.

[0128] Preferably, the compound of formula III-1 is selected from the group of the compounds of formulae III-1-1 to III-1-11, preferably of formula III-1-6.

[0129] [ka]

[0130] [ka]

[0131] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms, and alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represents a linear alkoxy group having 1 to 6 C atoms; L 31 and L 32 each independently represents F or Cl, preferably both represent F.

[0132] Preferably, the compound of formula III-2 is selected from the group of the compounds of formulae III-2-1 to III-2-10, preferably of formula III-2-6.

[0133] [ka]

[0134] [ka]

[0135] During the ceremony, Alkyl and alkyl *each independently represents a linear alkyl group having 1 to 6 carbon atoms, and alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represents a linear alkoxy group having 1 to 6 C atoms; L 31 and L 32 each independently represents F or Cl, preferably both represent F.

[0136] The medium may contain one or more compounds of formula IIIA-1 and / or IIIA-2.

[0137] [ka]

[0138] In the formula, L 31 and L 32 has the same meaning as given above in formula III, (O) represents O or a single bond, R IIIA is an alkyl or alkenyl group having up to 7 C atoms or a group Cy-C m H 2m+1 - represents m and n are the same or different and are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, Cy represents alkyl or alkenyl, each having up to 3 C atoms, or an alicyclic group having 3, 4 or 5 ring atoms, which may be substituted by halogen or CN, and preferably represents cyclopropyl, cyclobutyl or cyclopentyl.

[0139] The compounds of formula IIIA-1 and / or IIIA-2 are included in the medium either alternatively or additionally, preferably additionally, to the compound of formula III.

[0140] Highly preferred compounds of formula IIIA-1 and IIIA-2 are:

[0141] [ka]

[0142] [ka]

[0143] In the formula, alkoxy is a linear alkoxy group having 1 to 6 C atoms, or alternatively -(CH2) n F (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0144] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula III-3.

[0145] [ka]

[0146] During the ceremony R 31 , R 32 are the same or different and represent H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that one or more CH groups in these groups are not directly linked to O atoms, and are -C≡C-, -CF2O-, -OCF2-, -CH=CH-, [ka] It may be replaced by -O-, -CO-O- or -O-CO-, in which additionally one or more H atoms may be replaced by halogen.

[0147] The compound of formula III-3 is preferably selected from the group of compounds of formulae III-3-1 to III-3-10.

[0148] [ka]

[0149] [ka]

[0150] In the formula, R 32 is 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 (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0151] In a preferred embodiment of the invention the medium comprises one or more compounds of formulae III-4 to III-6, preferably of formula III-5.

[0152] [ka]

[0153] where the parameters have the meanings given above and R 31 preferably represents a linear alkyl group, R 32 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0154] In a preferred embodiment, the medium comprises one or more compounds of formula I selected from the group of compounds of formulae III-7 to III-9, preferably of formula III-8.

[0155] [ka]

[0156] where the parameters have the meanings given above and R 31 preferably represents a linear alkyl group, R 32 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0157] In a preferred embodiment, the medium comprises one or more compounds of formula IV.

[0158] [ka]

[0159] During the ceremony, R 41 represents an unsubstituted alkyl group having 1 to 7 C atoms or an unsubstituted alkenyl group having 2 to 7 C atoms, preferably an n-alkyl group, particularly preferably having 2, 3, 4 or 5 C atoms, R 42 represents an unsubstituted alkyl group having 1 to 7 C atoms or an unsubstituted alkoxy group having 1 to 6 C atoms (both of which preferably have 2 to 5 C atoms), an unsubstituted alkenyl group having 2 to 7 C atoms, preferably having 2, 3 or 4 C atoms, more preferably a vinyl group or a 1-propenyl group, in particular a vinyl group.

[0160] The compound of formula IV is preferably selected from the group of compounds of formulae IV-1 to IV-4.

[0161] [ka]

[0162] During the ceremony, alkyl and alkyl' each independently represent an alkyl having 1 to 7 C atoms, preferably having 2 to 5 C atoms, alkenyl represents an alkenyl group having 2 to 5 C atoms, preferably 2 to 4 C atoms, particularly preferably 2 C atoms; alkenyl' represents an alkenyl group having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms, Alkoxy represents alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms.

[0163] The compound of formula IV-1 is preferably selected from the group of compounds of formulae IV-1-1 to IV-1-5.

[0164] [ka]

[0165] The compound of formula IV-2 is preferably selected from the compounds of formulae IV-2-1 and IV-2-2.

[0166] [ka]

[0167] The compound of formula IV-3 is preferably selected from the group of compounds of formulae IV-3-1 and IV-3-2:

[0168] [ka]

[0169] In the formula, alkyl has the meaning defined above.

[0170] The compounds of the formulae IV-3-1 and IV-3-2 are preferably selected from the following compounds:

[0171] [ka]

[0172] Very preferably, the medium according to the invention comprises a compound selected from the compounds of formula IV-4, in particular of the formulae IV-4-1 to IV-4-3:

[0173] [ka]

[0174] In one embodiment, the medium according to the invention comprises one or more compounds of formula I selected from the compounds of formulae I-1 to I-4 in combination with one or more compounds selected from the group of compounds of formulae IA-1 to IA-9.

[0175] [ka]

[0176] [ka]

[0177] In the formula, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or n-pentyl.

[0178] The liquid crystal medium preferably additionally comprises one or more compounds of the formula IVa.

[0179] [ka]

[0180] During the ceremony, R 41 and R 42 each independently of one another represents a straight-chain alkyl, alkoxy, alkenyl, alkoxyalkyl or alkoxy group having up to 12 C atoms, and [ka] Z 4 represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8-, or -CF=CF-.

[0181] Preferred compounds of formula IVa are shown below.

[0182] [ka]

[0183] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 C atoms.

[0184] The medium according to the invention preferably comprises at least one compound of formula IVa-1 and / or formula IVa-2.

[0185] The proportion of compounds of formula IVa in the mixture as a whole is preferably less than 5% by weight, very preferably less than 2% by weight.

[0186] Preferably the medium comprises one or more compounds of formulae IVb-1 to IVb-3.

[0187] [ka]

[0188] During the ceremony, Alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms, and alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 C atoms.

[0189] Among the compounds of the formulae IVb-1 to IVb-3, the compound of the formula IVb-2 is particularly preferred.

[0190] Particularly preferred are biphenyls.

[0191] [ka]

[0192] In the formula, alkyl *stands for an alkyl group having 1 to 6 C atoms, preferably for n-propyl. The medium according to the invention particularly preferably comprises one or more compounds of the formulae IVb-1-1 and / or IVb-2-3

[0193] In a particularly preferred embodiment, the medium according to the invention comprises one or more compounds of formula V

[0194] [ka]

[0195] During the ceremony, R 51 , R 52 represents an alkyl having 1 to 7 C atoms, an alkoxy having 1 to 7 C atoms, or an alkoxyalkyl, alkenyl, or alkenyloxy having 2 to 7 C atoms, [ka] represents Z 51 , Z 52 each independently represents -CH-CH-, -CH-O-, -CH=CH-, -C≡C-, -COO- or a single bond, and n is 1 or 2; However, compounds of formula CL are excluded.

[0196] The compound of formula V is preferably selected from the compounds of formulae V-1 to V-16.

[0197] [ka]

[0198] [ka]

[0199] In the formula, R 51 and R 52has the meaning given above in formula V. 51 and R 52 preferably, each independently represent a linear alkyl having 1 to 7 C atoms or an alkenyl having 2 to 7 C atoms.

[0200] Preferred media comprise one or more compounds of formula V-1, V-5, V-6, V-8, V-9, V-10, V-11, V-12, V-14, V-15 and / or V-16, very preferably V-5 or V-6.

[0201] A preferred medium according to the invention comprises one or more compounds of formula CL.

[0202] [ka]

[0203] During the ceremony R L represents H, a linear or branched alkyl or alkoxy group having 1 to 15 C atoms or a linear or branched alkenyl group having 2 to 15 C atoms, with the proviso that one or more CH2 groups in these groups are not directly linked to O atoms, [ka] -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO-, each of which may be replaced independently of the other, in which additionally one or more H atoms may be replaced by halogen; X L represents F, Cl, CN, CHF2, CF3, OCF3, or R L has one of the meanings Y L represents H, F, Cl or CH3.

[0204] The compound of formula CL is preferably selected from the group of compounds of formulae CL-1, CL-2 and CL-3.

[0205] [ka]

[0206] During the ceremony, R L1 and R L2 are identical or different and have the meaning given in formula I above and preferably denote alkyl or alkenyl having 1 to 7 or 2 to 7 C atoms, respectively, in which the CH2 group may be replaced by cyclopropane-1,2-diyl.

[0207] Highly preferred compounds of formula I are selected from the compounds of formulae CL-3-1 to CL-3-12:

[0208] [ka]

[0209] [ka]

[0210] In a preferred embodiment, the medium according to the invention comprises the compound CL-3-1.

[0211] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VI-1 to VI-21, preferably of the formula VI-4.

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] In the formula, R 6 represents a linear alkyl or alkoxy group having 1 to 6 C atoms, (O) represents -O- or a single bond, m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4. R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0216] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VII-1 to VII-9.

[0217] [ka]

[0218] [ka]

[0219] During the ceremony, R 7 represents a linear alkyl or alkoxy group having 1 to 6 C atoms or a linear alkenyl group having 2 to 6 C atoms, and and w is an integer from 1 to 6.

[0220] Further preferred embodiments are listed below.

[0221] a) A liquid-crystalline medium comprising at least one compound of the formulae Z-1 to Z-7.

[0222] [ka]

[0223] wherein R and alkyl have the meanings given above in formula III.

[0224] b) Preferred liquid crystal media according to the invention comprise one or more substances which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, the compounds of the formulae N-1 to N-5.

[0225] [ka]

[0226] R in the formula 1N and R 2N are each independently R 2A and preferably represents straight-chain alkyl, straight-chain alkoxy or straight-chain alkenyl, Z 1 and Z 2 each independently represents -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CHO-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond.

[0227] c) Preferred mixtures comprise one or more compounds selected from the group of the difluorodibenzochroman compounds of formula BC, the chromans of formula CR and the fluorinated phenanthrenes of formulae PH-1 and PH-2.

[0228] [ka]

[0229] During the ceremony, R B1 , R B2 , R CR1 , R CR2 , R 1 , R 2 are each independently R 2A where c is 0, 1 or 2. 1 and R 2preferably each independently denote alkyl or alkoxy having 1 to 6 C atoms.

[0230] Particularly preferred compounds of formulae BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.

[0231] [ka]

[0232] [ka]

[0233] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 C atoms, alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 C atoms.

[0234] Very particular preference is given to mixtures comprising one, two or three compounds of the formulae BC-2, BF-1 and / or BF-2.

[0235] d) Preferred mixtures contain one or more indane compounds of formula In.

[0236] [ka]

[0237] During the ceremony, R 11 , R 12 and R 13 each independently represents a linear alkyl, alkoxy, alkoxyalkyl or alkenyl group having 1 to 6 C atoms, R 12 and R 13 represents a halogen, preferably F, [ka] represents i represents 0, 1 or 2.

[0238] Preferred compounds of formula In are compounds of formulae In-1 to In-16 shown below.

[0239] [ka]

[0240] [ka]

[0241] [ka]

[0242] Particularly preferred are the compounds of formulae In-1, In-2, In-3 and In-4.

[0243] e) Preferred mixtures additionally contain one or more compounds of the formulae L-1 to L-5.

[0244] [ka]

[0245] [ka]

[0246] [ka]

[0247] During the ceremony, R, R 1 and R 2 are each independently R in formula IIA above.2A where alkyl represents an alkyl group having 1 to 6 C atoms. The parameter s represents 1 or 2.

[0248] The compounds of the formulae L1 to L9 are preferably used in concentrations of 5 to 15% by weight, in particular 5 to 12% by weight, very particularly preferably 8 to 10% by weight.

[0249] f) Preferred mixtures additionally contain one or more compounds of formula IIA-Y.

[0250] [ka]

[0251] R in the formula 11 and R 12 is the above formula IIA, R 2A has one of the meanings given to L 1 and L 2 are the same or different and represent F or Cl.

[0252] Preferred compounds of formula IIA-Y are selected from the group consisting of the following subformulae:

[0253] [ka]

[0254] [ka]

[0255] In the formula, Alkyl and Alkyl * each independently represents a linear alkyl group having 1 to 6 C atoms, Alkoxy represents a linear alkoxy group having 1 to 6 C atoms, Alkenyl and Alkenyl * each independently represents a linear alkenyl group having 2 to 6 C atoms, and O represents an oxygen atom or a single bond. Alkenyl and Alkenyl* preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0256] Particularly preferred compounds of formula IIA-Y are selected from the group consisting of the following subformulae:

[0257] [ka]

[0258] In the formula, Alkoxy and Alkoxy * has the meaning defined above and preferably denotes methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentyloxy.

[0259] Preferably, the medium according to the invention comprises a compound selected from the group of compounds of formulae ST-1 to ST-18, very preferably of formula ST-3.

[0260] [ka]

[0261] [ka]

[0262] [ka]

[0263] [ka]

[0264] During the ceremony R STrepresents H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that in addition, one or more CH groups in these groups are not directly linked to O atoms, and are -C≡C-, -CF2O-, -OCF2-, -CH=CH-, [ka] -O-, -CO-O-, -O-CO-, each independently of the other, in which one or more H atoms may be replaced by halogen; [ka] may be the same or different in each occurrence, [ka] represents Z ST represent, independently of one another, -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-, -CHO-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond; L 1 and L 2 each independently represents F, Cl, CH3, CF3 or CHF2, p represents 0, 1 or 2; q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0265] Of the compounds of formula ST, the compounds of formula ST-3 and especially the following are particularly preferred:

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] [ka]

[0271] In the compounds of formulae ST-3a and ST-3b, n preferably represents 3. In the compounds of formula ST-2a, n preferably represents 7.

[0272] Very particularly preferred mixtures according to the invention comprise one or more stabilizers from the group of compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1, ST-12.

[0273] [ka]

[0274] [ka]

[0275] Preferably the medium comprises one or more compounds of formula S.

[0276] [ka]

[0277] During the ceremony, 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; Sp represents a spacer group; R S represents H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; Z S are -O-, -C(O)O-, -(CH2) z -or-(CH2) z O-, or a single bond; HA is [ka] represents; R H H, O · , CH3, OH or OR S represents; R S1 , R S2 , R S3 and R S4 are identical or different and represent alkyl having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH3; G is H or R S or group Z S - represents HA; z is an integer from 1 to 6; and q is 2, 3 or 4, preferably 3 or 4.

[0278] In formula S, aryl represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 carbon atoms, and includes 1, 2, 3 or 4 aromatic rings, including fused rings, which may be bonded directly or via an alkylene linking group having 1 to 12 carbon atoms, in which one or more H atoms may be replaced by alkyl or alkoxy having 1 to 6 carbon atoms or alkenyl having 2 to 6 carbon atoms, or by CN, CF3 or halogen, in which one or more CH2 groups may be replaced by -O-, -S-, -NH-, -N(C1-C4-alkyl)-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH- or -C≡C-, respectively, so that O or S atoms are not directly bonded to each other.

[0279] Preferred aryl groups are benzene, naphthalene, anthracene, biphenyl, m-terphenyl, p-terphenyl and (phenylalkyl)benzenes, in which alkyl is a straight-chain alkyl having 1 to 12 C atoms.

[0280] In a preferred embodiment, the medium according to the invention has a parameter q of 3 and G of the group Z S - Includes compounds of formula S, which represents HA.

[0281] In another preferred embodiment the medium according to the invention has a structure in which the parameter q is 4 and G is H or R. S This includes compounds of formula S,

[0282] The compound of formula S is preferably selected from the compounds of formulae S-1, S-2 and S-3.

[0283] [ka]

[0284] [ka]

[0285] During the ceremony, R H has the meaning given above and is preferably H or O · represents; Sp is the same or different in each occurrence and represents a spacer group; W represents a linear or branched, optionally unsubstituted alkylene having 1 to 12 C atoms, in which one or more non-adjacent -CH2- groups may be replaced by -O-.

[0286] Preferred compounds of formula S-1 are selected from compounds of formula S-1-1:

[0287] [ka]

[0288] In the formula, R H has the meaning given above, preferably H or O · and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, and very preferably 7.

[0289] Preferred compounds of formula S-2 are selected from compounds of formula S-2-1:

[0290] [ka]

[0291] In the formula, R H has the meaning given above, preferably H or O · and n2 is the same or different at each occurrence, preferably the same and an integer from 0 to 12, preferably 2, 3, 4, 5 or 6, very preferably 3; and R S is identical or different at each occurrence, preferably identical and represents alkyl having 1 to 6 C atoms, preferably n-butyl.

[0292] Preferred compounds of formula S-3 are selected from compounds of formula S-3-1:

[0293] [ka]

[0294] In the formula, R H has the meaning given above, preferably H or O · and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, and very preferably 7.

[0295] The compounds of the formulae S and ST-1 to ST-18 are preferably present in the liquid crystal mixtures according to the invention in an amount of 0.005 to 0.5%, respectively, based on the mixture.

[0296] If the mixture according to the invention comprises two or more compounds from the group of compounds of the formulae S and ST-1 to ST-18, the concentrations increase correspondingly to 0.01 to 1% for two compounds, based on the mixture.

[0297] However, the total proportion of compounds of the formulae S and ST-1 to ST-18, based on the mixture according to the invention, preferably does not exceed 2%.

[0298] The liquid-crystalline media according to the invention, also referred to herein as liquid-crystalline host mixtures, are suitable for use in polymer-stabilized displays. For this purpose the media according to the invention may comprise one or more polymerizable compounds of formula P

[0299] [ka]

[0300] wherein each independently of one another is identical or different at each occurrence, P represents a polymerizable group; Sp represents a spacer group or a single bond; A 1 , A 2is an aromatic, heteroaromatic, alicyclic or heterocyclic group, preferably having 4 to 25 ring atoms, which may also contain fused rings, which group is unsubstituted or mono- or polysubstituted by L, Z 1 -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, R 0 , R 00 represents H or alkyl having 1 to 12 C atoms, R represents H, L or P-Sp-; L represents F, Cl, -CN, P-Sp- or linear, branched or cyclic alkyl having 1 to 25 C atoms, with the proviso that one or more non-adjacent CH groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly linked to each other, respectively, and with the proviso that one or more H atoms may be replaced by P-Sp-, F or Cl, z is 0, 1, 2 or 3, and n1 is 1, 2, 3 or 4.

[0301] The term "reliability" as used herein refers to the quality of a display's performance over time and under different stress loads such as light load, temperature, humidity, voltage, etc., and display effects such as image sticking (area and line image sticking), mura, smearing, etc., known to those skilled in the art of liquid crystal displays.

[0302] As a standard parameter for classifying reliability, the voltage holding ration (VHR) value is usually used, which is a measure of the maintenance of a constant electrical voltage in a test display. A high VHR is a prerequisite for a reliable LC medium.

[0303] Hereinafter, unless otherwise specified, the term "PSA" is used to refer to polymer-sustained alignment displays in general, and the term "PS" is used to refer to specific display modes such as PS-VA and PS-TN.

[0304] As used herein, the terms "active layer" and "switchable layer" refer to a layer in an electro-optical display, e.g. an LC display, that contains one or more types of molecules with structural and optical anisotropy, e.g. LC molecules, that undergo a change in molecular orientation upon application of an external stimulus, such as an electric or magnetic field, resulting in a change in the transparency of the layer for polarized or unpolarized light.

[0305] As used herein, the terms "tilt" and "tilt angle" are understood to mean the tilted orientation of the LC molecules of the LC medium in an LC display (herein preferably a PSA display) relative to the cell surface. In this specification, tilt angle means the average angle (less than 90°) between the molecular long axis (LC director) of the LC molecules and the surface of the flat parallel outer plates forming the LC cell. In this specification, low values ​​of tilt angle (i.e., large deviation from the angle 90°) correspond to large tilt. A suitable method for measuring the tilt angle is given in the examples. Unless otherwise indicated, the values ​​of tilt angle disclosed above and below refer to this measurement method.

[0306] As used herein, the terms "reactive mesogen" and "RM" are understood to mean a compound containing a mesogenic or liquid crystal backbone and one or more functional groups attached to the backbone suitable for polymerization, which functional groups are also referred to as "polymerizable groups" or "P".

[0307] As used herein, unless otherwise stated, the term "polymerizable compound" is understood to mean a polymerizable monomeric compound.

[0308] As used herein, the term "low molecular weight compound" is understood as a term in contrast to "polymeric compound" or "polymer" to mean a compound that is monomeric and / or not prepared by a polymerization reaction.

[0309] As used herein, the term "non-polymerizable compound" is understood to mean a compound that does not contain any functional group suitable for polymerization under the conditions normally applied for the polymerization of RMs.

[0310] As used herein, the term "mesogenic group" refers to a group known to those skilled in the art and described in the literature, which essentially contributes to the generation of a liquid-crystalline (LC) phase in low molecular weight or polymeric substances 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 by itself. It is also possible that a mesogenic compound exhibits 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 shaped units. A review of the terms and definitions used in relation to mesogens or LC compounds is given in Pure Appl.Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew.Chem. 2004, Vol. 116, p. 6340-6368.

[0311] As used herein, the terms "optically active" and "chiral" are synonymous for a material that can induce a helical pitch in a nematic host material, also referred to as a "chiral dopant."

[0312] As used herein, the term "spacer group", also referred to above and below as "Sp", is known to those skilled in the art and described in the literature, see for example Pure Appl.Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew.Chem. 2004, Vol. 116, p. 6340-6368. As used herein, the term "spacer group" or "spacer" refers to a flexible group, such as an alkylene group, that connects the mesogenic group and the polymerizable group(s) in a polymerizable mesogenic compound.

[0313] Similarly, in compounds of formula I, the spacer group links the optically active central hydrocarbon group and stabilizes the hindered amine functionality.

[0314] Above and below, [ka] represents a trans-1,4-cyclohexylene ring.

[0315] base [ka] The single bond shown between two ring atoms in can be attached to any non-bonded position of the benzene ring.

[0316] Above and below, "organic group" represents a carbon or hydrocarbon group.

[0317] The term "carbon group" refers to a monovalent or polyvalent organic group containing at least one carbon atom, provided that it either does not contain any additional type of atom (e.g., -C≡C-, etc.) or it may contain one or more additional types of atoms, such as, for example, N, O, S, B, P, Si, Se, As, Te, or Ge (e.g., carbonyl, etc.). The term "hydrocarbon group" refers to a carbon group that additionally contains one or more H atoms and may contain one or more heteroatoms, such as, for example, N, O, S, B, P, Si, Se, As, Te, or Ge.

[0318] "Halogen" represents F, Cl, Br or I, preferably F or Cl.

[0319] -CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e. [ka] Represents.

[0320] The carbon or hydrocarbon group may be saturated or unsaturated. The unsaturated group may be, for example, an aryl, alkenyl or alkynyl group. The carbon or hydrocarbon group having more than three C atoms may be linear, branched and / or cyclic, and may contain spiro-linked or fused rings.

[0321] The terms "alkyl," "aryl," "heteroaryl," etc. also include polyvalent radicals, such as alkylene, arylene, heteroarylene, etc.

[0322] The term "aryl" refers to an aromatic carbon group or a group derived therefrom. The term "heteroaryl" refers to an "aryl" as defined above containing one or more heteroatoms, preferably selected from N, O, S, Se, Te, Si and Ge.

[0323] Preferred carbon and hydrocarbon groups are optionally substituted linear, branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having 1 to 40, preferably 1 to 20, particularly 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, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25 C atoms, with the proviso that one or more C atoms may be replaced by a heteroatom, preferably selected from N, O, S, Se, Te, Si and Ge.

[0324] More preferred carbon and hydrocarbon groups are C1-C 20 Alkyl, C2-C 20 Alkenyl, C2-C 20 Alkynyl, C3-C 20 Allyl, C4~C 20 Alkyldienyl, C4-C 20 Polyenyl, C6-C 20 Cycloalkyl, C4-C 15 Cycloalkenyl, C6-C 30 Aryl, C6-C 30 Alkylaryl, C6-C 30 Aryl alkyl, C6-C 30 Alkylaryloxy, C6-C 30 Arylalkyloxy, C2-C 30 Heteroaryl, C2-C 30 It is heteroaryloxy.

[0325] C1~C 12 Alkyl, C2-C 12 Alkenyl, C2-C 12 Alkynyl, C6-C 25 Aryl and C2-C 25 Heteroaryl is especially preferred.

[0326] Further preferred carbon and hydrocarbon groups are alkyl, linear, branched or cyclic, having 1 to 20, preferably 1 to 12, C atoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN, with the proviso that one or more non-adjacent CH groups are each independently of one another -C(R x )=C(R x )-, -C≡C-, -N(R x ) -, -O-, -S-, -CO-, -CO-O-, -O-CO-, or -O-CO-O-.

[0327] R x preferably represents H, F, Cl, CN, a linear, branched or cyclic alkyl chain having 1 to 25 C atoms (with the proviso that in addition, one or more non-adjacent C atoms may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, with the proviso that one or more H atoms may be replaced by F or Cl), or 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.

[0328] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, and the like.

[0329] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, and the like.

[0330] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl and the like.

[0331] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, and the like.

[0332] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, and the like.

[0333] Aryl and heteroaryl groups may be monocyclic or polycyclic, i.e., they may contain one ring (such as phenyl) or two or more rings, and the groups may be fused (such as naphthyl) or covalently linked (such as biphenyl) or may contain a combination of fused and linked rings. Heteroaryl groups preferably contain one or more heteroatoms selected from O, N, S and Se.

[0334] Particularly preferred are monocyclic, bicyclic or tricyclic aryl groups having 6 to 25 C atoms and monocyclic, bicyclic or tricyclic heteroaryl groups having 5 to 25 ring atoms, which may contain fused rings and may be substituted.Furthermore, 5-, 6- or 7-membered aryl and heteroaryl groups are preferred, provided that in addition, one or more CH groups may be replaced by N, S or O, in such a way that the O and / or S atoms are not directly linked to one another.

[0335] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1':3',1"]terphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, 9,10-dihydrophenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, and the like.

[0336] Preferred heteroaryl groups are, for example, 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- Five-membered rings such as thiadiazole, 1,2,5-thiadiazole, and 1,3,4-thiadiazole; six-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, and 1,2,3,5-tetrazine; or indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, pristine, , naphthaimidazole, phenanthroimidazole, pyridaimidazole, pyrazineimidazole, quinoxalineimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoi Condensed groups such as isoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazothiophene, or a combination of these groups.

[0337] The aryl and heteroaryl groups mentioned above and below may also be substituted with alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or further aryl or heteroaryl groups.

[0338] (Non-aromatic) alicyclic and heterocyclic groups include both saturated rings, i.e. those containing exclusively single bonds, and also partially unsaturated rings, i.e. those which may also contain multiple bonds. Heterocyclic rings preferably contain one or more heteroatoms selected from Si, O, N, S and Se.

[0339] (Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e. containing only one ring (e.g. cyclohexane) or polycyclic, i.e. containing several rings (e.g. decahydronaphthalene or bicyclooctane). Saturated groups are particularly preferred. Furthermore, monocyclic, bicyclic or tricyclic groups having 5 to 25 ring atoms are preferred, which may contain fused rings and may be substituted. Furthermore, 5-, 6-, 7- or 8-membered carbocyclic groups are preferred, provided that in addition, 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-.

[0340] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, 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 tetrahydronaphthalene, decahydronaphthalene, 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-methanoindan-2,5-diyl.

[0341] Preferred substituents are solubility-promoting groups such as, for example, alkyl or alkoxy, electron-withdrawing groups such as fluorine, nitro or nitrile, or substituents for increasing the glass transition temperature (Tg) in the polymer, especially bulky groups such as, for example, t-butyl or optionally substituted aryl groups.

[0342] Preferred substituents are referred to below as "L S ", for example, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 , -C(=O)R x , -N(R x )2, linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms (wherein one or more H atoms may be replaced by F or Cl), optionally substituted silyl having 1 to 20 Si atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms.

[0343] In the formula, R x represents H, F, Cl, CN, a linear, branched or cyclic alkyl chain having 1 to 25 C atoms, with the proviso that one or more non-adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, in such a way that the O- and / or S- atoms are not directly linked to one another, with the proviso that one or more H atoms may be replaced by F, Cl, P- or P-Sp-, respectively, and Y 1 represents a halogen.

[0344] The "substituted silyl or aryl" is preferably a halogen, -CN, R 0 , -OR 0 , -CO-R 0 , -CO-OR 0 , -O-CO-R 0 OR-O-CO-OR 0where R 0 represents H or alkyl having 1 to 20 C atoms.

[0345] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and also phenyl.

[0346] A 1 and A 2 Very preferably [ka] where L has one of the meanings given above and r represents 0, 1, 2, 3 or 4, in particular [ka] Represents.

[0347] The polymerizable group P is a group suitable for polymerization reactions, such as, for example, free-radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-analogous reactions, such as, for example, addition or condensation onto a polymer backbone. Groups for chain polymerization, especially those containing a C=C double bond or a C≡C triple bond, and also groups suitable for ring-opening polymerization, such as, for example, oxetane or epoxide groups, are particularly preferred.

[0348] The preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, [ka] CH2=CW 2 -(O) k3 -, C.W. 1 =CH-CO-(O) k3 -, C.W. 1 =CH-CO-NH-, CH2=CW 1-CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -, HS-CW 2 W 3 -, H.W. 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si-, wherein W 1 stands for H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W 2 and W 3 each independently of one another denotes H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each independently of one another represents H, Cl or an alkyl having 1 to 5 C atoms, Phe represents 1,4-phenylene which may be substituted with one or more groups L as defined above other than P-Sp-, 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.

[0349] Highly preferred groups P are CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, [ka] CH2=CW 2 -O-, CH2=CW 2 -, C.W. 1 =CH-CO-(O) k3 -, C.W. 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si-, wherein W 1 stands for H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W 2 and W 3 each independently of one another denotes H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each independently represents H, Cl or an alkyl having 1 to 5 C atoms; Phe represents 1,4-phenylene; k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer of 1 to 10.

[0350] Very particularly preferred groups P are CH2=CW 1-CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, further CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-, [ka] The compound is selected from the group consisting of:

[0351] More preferably, the polymerizable group P is selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide groups, most preferably acrylate and methacrylate.

[0352] When the spacer group Sp is different from a single bond, Sp is preferably of the formula Sp"-X", such that each group P-Sp- corresponds to the formula R-Sp"-X"-, where Sp" and X" have the following meanings:

[0353] Sp" represents a linear or branched alkylene having 1 to 20, preferably 1 to 12, C atoms, which may be mono- or polysubstituted by F, Cl, Br, I or CN, provided that in addition, one or more non-adjacent CH groups are each independently -O-, -S-, -NH-, -N(R 0 )-, -Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-, -O-CO-N(R 0 )-, -N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C-, “X” is -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 represents -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond; R 0 and R 00 each independently represent H or alkyl having 1 to 20 C atoms, Y 2 and Y 3 each independently represents H, F, Cl or CN.

[0354] 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.

[0355] Exemplary spacer groups Sp and -Sp"-X"- include, 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 In the formula, p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 has the meaning given above.

[0356] Particularly preferred spacer groups Sp and -Sp"-X"- are -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, in which p1 and q1 have the meanings given above.

[0357] Particularly preferred radicals Sp" are, in their respective linear forms, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0358] In a preferred embodiment of the invention, the compounds of formula P and its subformulae have the group Sp-P as Sp(P) s (wherein s is 2 or more).

[0359] 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. Highly preferred compounds of formula P according to this preferred embodiment contain a group selected from the following formulae:

[0360] [ka]

[0361] where P is as defined in formula P; alkyl denotes a single bond or a linear or branched alkylene having 1 to 12 C atoms, which is unsubstituted or mono- or polysubstituted by F, Cl or CN, with the proviso that one or more non-adjacent CH groups are each independently connected to each other such that O and / or S atoms are not directly linked to each other, i.e., -C(R 0 )=C(R 0 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O-, provided that R 0 has the meaning given above, aa and bb each independently represent 0, 1, 2, 3, 4, 5 or 6; X has one of the meanings given under X″ and is preferably O, CO, SO2, O—CO—, CO—O or a single bond.

[0362] Preferred spacer groups Sp(P)2 are selected from formulae S1, S2 and S3.

[0363] Highly preferred spacer groups Sp(P)2 are selected from the following subformulae:

[0364] [ka]

[0365] In the compounds of formula P and subformulas thereof as described above and below, P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably acrylate and methacrylate.

[0366] Further preferred are compounds of formula P and sub-formulas thereof as described above and below, in which all polymerizable groups P present in the compound have the same meaning, very preferably denoting acrylate or methacrylate, most preferably methacrylate.

[0367] In the compounds of formula P and its subformulas as described above and below, R preferably represents P-Sp.

[0368] Sp is 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 Sp is -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 Further preferred are compounds of formula P and its subformulas as defined above and below, in which the O atom or CO group, respectively, is linked to a benzene ring.

[0369] Further preferred are compounds of formula P and subformulae thereof as defined above and below, in which at least one group Sp is a single bond.

[0370] At least one group Sp is different from a single bond and is preferably -(CH2) p1 -, -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 where p1 is 2, 3, 4, 5 or 6 and Sp is -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 Further preferred are compounds of formula P and its subformulas as defined above and below, in which the O atom or CO group, respectively, is linked to a benzene ring.

[0371] Highly preferred group -A in formula P 1 -(ZA 2 ) z is selected from the following formula:

[0372] [ka]

[0373] wherein at least one benzene ring is substituted with at least one group L, and the benzene ring may be further substituted with one or more groups L or P-Sp-.

[0374] Preferred compounds of formula P and subformulae thereof are selected from the following preferred embodiments (including any combination thereof): ·All groups P in the compound have the same meaning. -A 1 -(ZA 2 ) z is selected from A1, A2 and A5. The compound has exactly two polymerizable groups (represented by the group P). The compound has exactly three polymerizable groups (represented by groups P). ·P is selected from the group consisting of acrylates, methacrylates and oxetanes, very preferably it is an acrylate or methacrylate. P is a methacrylate. All groups Sp are single bonds. 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. If Sp is different from a single bond, -(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 CO group, respectively, is linked to the benzene ring. Sp is a single bond or -(CH2) p2 -, -(CH2) p2 -O-, -(CH2) p2 -CO-O-, -(CH2) p2 represents -O-CO-, where p2 is 2, 3, 4, 5 or 6, and the O atom or CO group, respectively, is linked to the benzene ring. ·R stands for P-Sp-. R does not represent or contain a polymerizable group. R does not represent or does not contain a polymerizable group and represents a linear, branched or cyclic alkyl having 1 to 25 C atoms, with the proviso that one or more non-adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, in such a way that the O and / or S atoms are not directly linked to each other, respectively, with the proviso that one or more H atoms are not directly linked to each other, respectively, with the proviso that one or more H atoms are not directly linked to each other, a may be replaced by L or L' represents F, Cl or CN. ·L is F.

[0375] Suitable and preferred compounds of formula P are selected from the following formulae:

[0376] [ka]

[0377] [ka]

[0378] [ka]

[0379] [ka]

[0380] [ka]

[0381] [ka]

[0382] in which the individual radicals have the following meanings: P 1 , P2 and P 3 each independently represents an acrylate or methacrylate group, Sp 1 , Sp 2 and Sp 3 each independently of the other denotes a single bond or a spacer having one of the meanings given above and below for Sp, particularly preferably -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO- or -(CH2) p1 -O-CO-O-, where p1 is an integer of 1 to 12; In addition, the group P 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 -At least one of R aa one or more groups P 1 -Sp 1 -, P 2 -Sp 2 - and P 3 -Sp 3 - is R aa may also represent R aa is H, F, Cl, CN, or a linear or branched alkyl having 1 to 25 C atoms (provided that in addition, one or more non-adjacent CH groups may each be independently C(R) such that O and / or S atoms are not directly linked to each other). 0 )=C(R 00 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, provided that in addition, one or more H atoms may be replaced by F, Cl, CN or P 1 -Sp 1-), particularly preferably linear or branched, optionally monofluorinated or polyfluorinated, alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, with the proviso that alkenyl and alkynyl groups have at least 2 C atoms and branched groups have at least 3 C atoms, R 0 , R 00 each, independently of one another, identically or differently at each occurrence, represents H or alkyl having 1 to 12 C atoms, R y and R z each independently represents H, F, CH3 or CF3, X 1 , X 2 and X 3 each independently represents -CO-O-, -O-CO- or a single bond, Z 1 -O-, -CO-, -C(R y R z )- or -CF2CF2-, Z 2 and Z 3 are each independently -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2) n -, where n is 2, 3 or 4; L is, identically or differently, in each occurrence, F, Cl, CN or an alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy which may be linear or branched and mono- or polyfluorinated and has 1 to 12 C atoms, preferably F, L' and L" each independently represent H, F or Cl; k represents 0 or 1; r represents 0, 1, 2, 3 or 4; s represents 0, 1, 2 or 3; t represents 0, 1 or 2; x represents 0 or 1.

[0383] Particularly preferred are compounds of formulae P2, P13, P17, P22, P23, P24, P30, P31 and P32.

[0384] Further, trireactive compounds P15 to P30, in particular P17, P18, P19, P22, P23, P24, P25, P26, P30, P31 and P32 are preferred.

[0385] In the compounds of the formulae P1 to P32, the group [ka]

[0386] with L, identically or differently in each occurrence, having one of the meanings given above and below, preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, OCH3, COCH3 or OCF3, in particular F or CH3.

[0387] Very particularly preferred compounds of formula P are selected from table E below, in particular those of formula 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.

[0388] To produce a PSA display, polymerizable compounds contained in the LC medium are polymerized or crosslinked (if a compound contains more than one polymerizable group) by in situ polymerization in the LC medium between the substrates of the LC display, optionally with application of a voltage to the electrodes.

[0389] The structure of the PSA display according to the invention corresponds to the usual structure of the PSA display as described in the prior art cited at the beginning. A structure without protrusions is preferred, in particular in which the electrode on the color filter side is not structured and only the electrode on the TFT side has slits. A particularly suitable and preferred electrode structure for PS-VA displays is described, for example, in US 2006 / 0066793 A1.

[0390] A preferred PSA type LC display of the present invention is a first substrate including pixel electrodes defining pixel areas, the pixel electrodes being connected to switch elements disposed in each pixel area and optionally having a micro-slit pattern, and optionally a first alignment layer disposed on the pixel electrodes; a second substrate including a common electrode layer, which may be disposed over the entire portion of the second substrate facing the first substrate, and an optional second alignment layer; an LC layer disposed between a first substrate and a second substrate, the LC medium layer comprising a polymerizable component comprising one or more compounds of formula R and a liquid crystal host comprising those described above and below, whereby the polymerizable component may be polymerized; Includes.

[0391] 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, the alignment layer is selected so that it directs the LC molecules into a homeotropic (or vertical) alignment (i.e. perpendicular to the surface) or tilted alignment. Such an alignment layer can, for example, comprise a polyimide, which may be rubbed or prepared by a photoalignment method.

[0392] The LC layer with the LC medium can be placed between the substrates of the display by methods commonly used in the manufacture of displays, e.g. the so-called one-drop-filling (ODF) method. The polymerizable components of the LC medium are then polymerized, e.g. by UV photopolymerization. The polymerization can be carried out in one step or in two or more steps.

[0393] PSA displays may contain further elements such as colour filters, black matrices, passivation layers, optical retardation layers, transistor elements for addressing individual pixels, all of which are known to those skilled in the art and can be used without the exercise of patentable skill.

[0394] The electrode structure can be designed by one skilled in the art according to the type of individual display, for example, electrodes with slits and / or ridges or protrusions can be provided to induce multi-domain alignment of LC molecules to generate two, four or more different tilt alignment directions for PS-VA displays.

[0395] Upon polymerization, the polymerizable compound forms a cross-linked polymer, which induces 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 cross-linked polymer formed by the polymerizable compound phase-separates or precipitates from the LC medium, forming a polymer layer on the substrate or electrodes or alignment layers provided thereon. Microscopy data (such as SEM and AFM) confirmed that at least a portion of the formed polymer accumulates at the LC / substrate interface.

[0396] The polymerization can be carried out in a single step, or it is also possible to first carry out the polymerization in a first step, optionally with the application of a voltage, to generate a pretilt angle, followed by a second polymerization step, without the application of a voltage, to polymerize or crosslink the compounds that did not react in the first step ("final cure").

[0397] Suitable and preferred polymerization methods are, for example, thermal or photopolymerization, preferably photopolymerization, especially UV-induced photopolymerization, which can be achieved by exposing the photopolymerizable compound to UV radiation.

[0398] One or more polymerization initiators can be added to the LC medium. Suitable conditions for polymerization and suitable types and amounts of initiators are known to the skilled artisan and described in the literature. For example, commercially available photoinitiators Irgacure 651®, Irgacure 184®, Irgacure 907®, Irgacure 369® or Darocure 1173® (Ciba) are suitable for free radical polymerization. When a polymerization initiator is used, the proportion of initiator is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

[0399] The polymerizable compound according to the present invention is also suitable for polymerization without initiator, which entails particular advantages such as lower material costs and, in particular, less contamination of the LC medium by the residual amount of initiator or its degradation products.In this way, polymerization can also be carried out without adding initiator.Therefore, in a preferred embodiment, the LC medium does not contain polymerization initiator.

[0400] The LC medium may also contain one or more stabilizers, for example to prevent undesired spontaneous polymerization of the RM during storage or transport. Suitable types and amounts of stabilizers are known to the skilled artisan and described in the literature. Commercially available stabilizers, for example from the Irganox® series (Ciba), such as Irganox® 1076, are particularly suitable. When using a stabilizer, the proportion of the stabilizer is preferably 10 to 500,000 ppm, particularly preferably 50 to 50,000 ppm, based on the total amount of the RM or polymerizable component (component P).

[0401] The polymerizable compounds of formula P show particularly good UV absorption and are therefore particularly suitable for a method of preparing a PSA display comprising one or more of the following features: exposing the polymerizable medium to UV light within the display in a two-step process including a first UV exposure step ("UV-1 step") to generate the tilt angle and a second UV exposure step ("UV-2 step") to complete the polymerization; The polymerizable medium is exposed in the display to UV light produced by energy-saving UV lamps (also known as "green UV lamps"). These lamps are characterized by a relatively low intensity (1 / 100 to 1 / 10 of conventional UV lamps) in the absorption spectrum from 300 to 380 nm and are preferably used in the UV2 process, but can also be used in the UV1 process if high intensities must be avoided; To avoid exposure to short wavelength UV light in the PS-VA process, the polymerizable medium is exposed in the display to UV light produced by a UV lamp with an emission spectrum shifted to longer wavelengths (preferably 340 nm or longer).

[0402] Either by using lower intensity or by shifting to longer wavelength UV, the organic layers are protected from damage that can be caused by UV light.

[0403] Preferred embodiments of the present invention relate to a method for preparing a PSA display as described above and below, comprising one or more of the following features: · exposing the polymerizable LC medium to UV light in two steps, including a first UV exposure step ("UV-1 step") to generate the tilt angle and a second UV exposure step ("UV-2 step") to complete the polymerization; The polymerizable LC medium is illuminated at 0.5 mW / cm within the wavelength range of 300-380 nm. 2 ~10mW / cm 2 (preferably, this UV lamp is used in the UV2 step, and optionally also in the UV1 step); The polymerizable LC medium is exposed to UV light having a wavelength of 340 nm or more and preferably 400 nm or less.

[0404] This preferred method can be carried out, for example, by using a desired UV lamp, or by using a bandpass filter and / or a cutoff filter that substantially transmits UV light having a desired wavelength and substantially blocks light having an undesired wavelength. For example, if irradiation with UV light having a wavelength λ of 300 to 400 nm is desired, UV exposure can be carried out using a wide bandpass filter that substantially transmits wavelengths λ of more than 300 nm and less than 400 nm. If irradiation with UV light having a wavelength λ of more than 340 nm is desired, UV exposure can be carried out using a cutoff filter that substantially transmits wavelengths λ of more than 340 nm.

[0405] "Substantially transmit" means that the filter transmits a majority of incident light of a desired wavelength, preferably at least 50% intensity. "Substantially block" means that the filter does not transmit a majority of incident light of undesired wavelengths, preferably at least 50% intensity. "Desired (undesired) wavelength" means, for example, in the case of a bandpass filter, wavelengths within (outside) a given range of λ, and in the case of a cutoff filter, wavelengths above (below) a given value of λ.

[0406] This preferred method allows for the manufacture of displays using longer wavelength UV, thereby reducing or avoiding the deleterious and damaging effects of the shorter wavelength components of UV light.

[0407] The UV irradiation energy is generally 6 to 100 J, depending on the conditions of the manufacturing process.

[0408] Preferably, the LC medium according to the invention consists essentially of a polymerizable component P) comprising a polymerizable compound of formula R as described above and below or one or more polymerizable compounds of formula P, an LC host mixture and an optically active component comprising one or more chiral dopants. However, the LC medium may additionally comprise one or more further components or additives, preferably selected from the following list without limitation: comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobizing agents, adhesives, flow improvers, antifoaming agents, degassing agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0409] Particular preference is given to LC media which comprise one, two or three polymerisable compounds of the formula P.

[0410] Preferably the proportion of compounds of formula P in the LC medium is from >0% to <5%, very preferably from >0% to <1%, most preferably from 0.01 to 0.5%.

[0411] In a preferred embodiment, the medium according to the invention comprises one or more compounds of formula S in a total concentration preferably in the range of from 10 ppm to 2000 ppm, more preferably from 100 ppm to 1000 ppm, even more preferably from 150 ppm to 500 ppm, very preferably from 200 ppm to 400 ppm, in particular from 250 to 300 ppm.

[0412] In another preferred embodiment, the medium according to the invention comprises one or more compounds of formula S in a total concentration preferably in the range of from 1000 ppm to 5000 ppm, more preferably from more than 1000 ppm to 5000 ppm, even more preferably from 1200 ppm to 4500 ppm, very preferably from 2000 ppm to 4000 ppm, in particular from 2500 to 3500 ppm.

[0413] The medium according to the present invention preferably has a negative dielectric anisotropy.

[0414] The medium according to the invention comprises one or more compounds of formula I in a total concentration ranging from greater than 0% to 20%, preferably from 1% to 15%, more preferably from 2% to 13%, very preferably from 3% to 12%.

[0415] The medium according to the invention is preferably

[0416] one or more compounds selected from the group of compounds of formulae IIA, IIB, IIC and IID in a total concentration in the range of 9% to 70%, more preferably 10% to 65%, very preferably 11% to 64%, in particular 28% to 42% or 9% to 20% or 50% to 64%,

[0417] and / or one or more compounds selected from the group of compounds of formulae IIA, IIB, IIC and IID and additionally one or more compounds of formula III in a total concentration ranging from 20% to 60%, more preferably from 25% to 55%, very preferably from 27% to 52%,

[0418] and / or one or more compounds of formula IIA, preferably of formula IIA-10, in a total concentration ranging from 1% to 30%, more preferably from 2% to 28%, very preferably from 3% to 27%,

[0419] or one or more compounds of formula IIA, preferably of formula IIA-10, preferably in a total concentration ranging from 1% to 10%, more preferably from 2% to 9%, very preferably from 3% to 8%,

[0420] or less than 2%, preferably 0-1%, of one or more compounds of formula IIA,

[0421] and / or one or more compounds of formula IIB, preferably of formula IIB-2 and / or IIB-10, in a total concentration in the range of 1% to 30%, more preferably 2% to 28%, very preferably 3% to 25%, in particular 10% or 15% to 25%,

[0422] and / or one or more compounds of formula IIC, preferably in a total concentration ranging from 1% to 20%, more preferably from 2% to 18%, very preferably from 3% to 16%, in particular from 4% to 15%,

[0423] and / or one or more compounds of formula IID, preferably of formula IID-4, preferably in a total concentration ranging from 5% to 25%, more preferably from 7% to 20%, very preferably from 8% to 18%,

[0424] and / or one or more compounds of formulae IIB and IID in a total concentration ranging from 18% to 45%, more preferably from 22% to 38%, very preferably from 25% to 35%,

[0425] and / or one or more compounds of formula IIB and IIC in a total concentration ranging from 5% to 28%, more preferably from 8% to 23%, very preferably from 10% to 20%,

[0426] and / or one or more compounds of formula III, preferably of formula III-2, more preferably of formula III-2-6, preferably in a total concentration ranging from 3% to 20%, more preferably from 5% to 17%, very preferably from 6% to 15%,

[0427] and / or one or more compounds of formula III-2, more preferably of formula III-2-6 and one or more compounds of formula III-3 in a total concentration ranging from 10% to 30%, more preferably from 15% to 27%, very preferably from 18% to 24%,

[0428] and / or one or more compounds of formula IV in a total concentration ranging from 20% to 65%, more preferably from 28% to 58%, even more preferably from 30% to 55%, very preferably from 32% to 50%, in particular from 35% to 48%,

[0429] and / or one or more compounds of formula IV and one or more compounds of formula IVa and / or IVb, preferably in a total concentration in the range of 28% to 70%, more preferably 30% to 65%, even more preferably 35% to 62%, very preferably 40% to 60%, in particular 42% to 58%,

[0430] and / or one or more compounds of formula IV-1, preferably in a total concentration ranging from 1% to 15%, more preferably from 2% to 12%, even more preferably from 3% to 10%, very preferably from 3% to 8%,

[0431] and / or one or more compounds of formula IV-2, preferably at a total concentration in the range of 0.2% to 5%, more preferably 0.5% to 3%, even more preferably 1% to 2%,

[0432] and / or one or more compounds of formula IV-3, preferably selected from formulae IV-3-1 and IV-3-2, very preferably from formulae IV-3-1a and / or IV-3-1c and / or IV-3-2a and / or IV-3-2b, preferably in a total concentration in the range of 25% to 55%, more preferably 28% to 50%, even more preferably 32% to 47%, very preferably 38% to 45%,

[0433] and / or one or more compounds of formulae IV-3-2a and / or IV-3-2b, preferably in a total concentration ranging from 16% to 32%, more preferably from 18% to 30%, even more preferably from 20% to 28%, very preferably from 22% to 26%,

[0434] and / or one or more compounds of formula IVb, preferably IVb-2-3, in a total concentration ranging from 1% to 20%, more preferably from 2% to 18%, even more preferably from 4% to 16%, very preferably from 5% to 15%,

[0435] and / or one or more compounds of formula V in a total concentration ranging from 3% to 15%, more preferably from 4% to 14%, even more preferably from 5% to 13%, very preferably from 6% to 12%,

[0436] and / or one or more compounds of formula IIA-Y, preferably of formula IIA-Y6, at a total concentration in the range of 0.5% to 10%, more preferably 1% to 8%, very preferably 2% to 5% include.

[0437] In a very preferred embodiment the medium according to the invention comprises

[0438] one or more compounds of formula I-3a, and

[0439] one or more compounds of formula IIB, preferably of formula IIB-2 and / or IIB-10, in a total concentration ranging from 12% to 32%, more preferably from 14% to 30%, very preferably from 15% to 27%

[0440] and one or more compounds of formula IID, preferably of formula IID-4, preferably in a total concentration ranging from 5% to 20%, more preferably from 7% to 18%, very preferably from 8% to 16%

[0441] and one, two or three compounds of formula III-2-6 in a total concentration ranging from 3% to 20%, more preferably from 5% to 17%, very preferably from 7% to 15%;

[0442] and one or more compounds of formula IV-1 in a total concentration ranging from 1% to 15%, more preferably from 2% to 12%, even more preferably from 3% to 10%, very preferably from 3% to 8%,

[0443] and one or more compounds of formulae IV-3-1a and / or IV-3-1b in a total concentration ranging from 12% to 25%, more preferably from 14% to 22%, very preferably from 16% to 20%,

[0444] and one or more compounds of formulae IV-3-2a and / or IV-3-2b in a total concentration in the range of 16% to 32%, more preferably 18% to 30%, even more preferably 20% to 28%, very preferably 22% to 26% include.

[0445] In another highly preferred embodiment the medium according to the invention comprises

[0446] one or more compounds of formula I-3b, and

[0447] one or more compounds of formula IIB, preferably of formula IIB-2 and / or IIB-10, in a total concentration ranging from 6% to 32%, more preferably from 9% to 30%, very preferably from 10% to 22%

[0448] and one or more compounds of formula IID, preferably of formula IID-4, preferably in a total concentration ranging from 5% to 25%, more preferably from 7% to 22%, very preferably from 8% to 20%

[0449] and one, two or three compounds of formula III-2-6 in a total concentration ranging from 3% to 20%, more preferably from 5% to 17%, very preferably from 7% to 15%;

[0450] and one or more compounds of formula IV-1 in a total concentration ranging from 1% to 20%, more preferably from 2% to 18%, even more preferably from 3% to 15%, very preferably from 4% to 13%,

[0451] and one or more compounds of formulae IV-3-1a and / or IV-3-1b and / or IV-3-1c in a total concentration in the range of 12% to 40%, more preferably 14% to 35%, very preferably 16% to 30%,

[0452] and one or more compounds of formulae IV-3-2a and / or IV-3-2b in a total concentration in the range of 3% to 35%, more preferably 5% to 30%, even more preferably 6% to 26%, very preferably 7% to 24% include.

[0453] The liquid crystal media according to the invention advantageously have a nematic phase preferably at temperatures from -20°C to 70°C, particularly preferably from -30°C to 72°C and very particularly preferably from -40°C to 74°C.

[0454] In a first preferred embodiment the medium according to the invention has a clearing temperature of 70°C or more, preferably 72°C or more, more preferably 73°C or more, in particular 74°C or more.

[0455] The expression "having a nematic phase" means, on the one hand, that no smectic phases and no crystallization are observed below the corresponding temperature, and, on the other hand, that no clearing (transition to an isotropic phase) occurs upon heating of the nematic phase at a given temperature. The low-temperature studies are carried out with a flow viscometer at the corresponding temperature and are confirmed by storage for at least 100 hours in test cells with layer thicknesses corresponding to the electro-optical application. If the storage stability in test cells at a temperature of -20 ° C is more than 1000 hours, the medium is called stable at this temperature. For temperatures of -30 ° C and -40 ° C, the corresponding times are 500 hours and 250 hours, respectively. At higher temperatures, the clearing point is measured in a capillary tube in the conventional manner.

[0456] The liquid crystal mixture preferably has a maximum viscosity of 30 mm at 20° C. 2 ·Seconds -1 Flow viscosity ν 20 has.

[0457] The liquid crystal mixtures according to the invention are preferably nematic at temperatures below -20°C, preferably below -30°C, very preferably below -40°C.

[0458] In a preferred embodiment of the invention, the medium has a birefringence of 0.105 or greater.

[0459] In a preferred embodiment of the invention the medium has a birefringence in the range of 0.1050 to 0.155, more preferably 0.1055 to 0.150, very preferably 0.110 to 0.145, especially 0.115 to 0.143.

[0460] In a preferred embodiment of the invention the medium has a birefringence in the range of 0.125 to 0.155, more preferably 0.130 to 0.150, very preferably 0.135 to 0.145, especially 0.137 to 0.143.

[0461] In a preferred embodiment of the invention, the medium has a birefringence in the range of 0.100 to 0.113, preferably 0.105 to 0.109.

[0462] In a preferred embodiment of the invention, the medium has a birefringence in the range of 0.115 to 0.128, preferably 0.118 to 0.122.

[0463] In a preferred embodiment, the liquid crystal mixture according to the invention has a dielectric anisotropy Δε of −1.8 to −5.0, preferably of −1.9 to −4.8, in particular of −2.0 to −3.9.

[0464] In a preferred embodiment, the liquid crystal mixture according to the invention has a dielectric anisotropy Δε of −2.0 to −3.8, preferably −2.3 to −3.4, in particular −2.8 to −3.2.

[0465] The rotational viscosity γ1 at 20° C. is preferably within a range of 60 to 120 mPas, and more preferably 70 to 110 mPa·s.

[0466] The elastic constant K1 is preferably in the range of 17.0 to 25.0, more preferably 18.0 to 24.0, and particularly preferably 19.0 to 22.0.

[0467] The elastic constant K3 is preferably within the range of 16.0 to 24.0, more preferably 17.0 to 23.0, and particularly preferably 18.0 to 21.0.

[0468] In addition, the liquid-crystal media according to the invention have high values ​​of the voltage holding ratio in a liquid-crystal cell.

[0469] In general, liquid crystal media having a low addressing voltage or threshold voltage show a lower voltage holding ratio than those having a high addressing voltage or threshold voltage and vice versa.

[0470] In the present invention, the term "dielectrically positive compound" refers to a compound having a Δε greater than 1.5, the term "dielectrically neutral compound" refers to a Δε between -1.5 and 1.5, and the term "dielectrically negative compound" refers to a Δε smaller than -1.5. The dielectric anisotropy of the compound is determined by dissolving 10% of the compound in a liquid crystal host and measuring the capacitance of the resulting mixture at 1 kHz in at least one test cell with homeotropic and homogeneous surface alignment, respectively, with a layer thickness of 20 μm. The measuring voltage is typically between 0.5 V and 1.0 V, but always lower than the capacitance threshold of the respective liquid crystal mixture under consideration.

[0471] All temperature values ​​given in this invention are in °C.

[0472] The mixtures according to the invention are suitable for all VA-TFT applications, e.g. 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.

[0473] It will be appreciated by those skilled in the art that the VA, IPS or FFS mixtures of the present invention may also contain compounds in which, for example, H, N, O, Cl and F are replaced by the corresponding isotopes.

[0474] The compounds according to the invention can be synthesized by known methods described in the literature (e.g. standard works such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart) or in a similar manner under known reaction conditions suitable for said reactions. Also, per se known variations can be used here, although not mentioned here. In particular, they can be prepared as described in the following reaction schemes or in a similar manner. Further methods for preparing the compounds of the invention can be taken from the examples.

[0475] Other mesogenic compounds not explicitly mentioned above can also be advantageously used in the medium according to the invention, such compounds being known to those skilled in the art.

[0476] In the present invention and the following examples, the structures of liquid crystal compounds are represented by acronyms, and the conversion to chemical formulas is performed according to the following Tables A to C. m H 2m+1 , C n H 2n+1 , and C l H 2l+1 or C m H 2m-1 , C n H 2n-1 andC l H 2l-1 is a linear alkyl or alkylene radical with in each case n, m and l C atoms. Preferably, n, m and l are each independently 1, 2, 3, 4, 5, 6 or 7. Table A gives the codes of the ring elements of the nucleus of the compounds, Table B lists the bridging units and Table C lists the meaning of the symbols of the left and rightmost groups of the molecules. The acronyms consist of the code of the ring element with an optional linking group followed by the first hyphen and the code of the leftmost group and the second hyphen and the code of the rightmost group. Table D gives examples of the structures of the compounds with their respective abbreviations.

[0477] <Table A: Ring elements>

[0478] [Table 1]

[0479] [Table 2]

[0480] [Table 3]

[0481] [Table 4]

[0482] <Table B: Cross-linking units>

[0483] [Table 5]

[0484] <Table C: Terminal group>

[0485] [Table 6]

[0486] In the table, n and m are each integers, and the three dots "..." are places for other abbreviations from this table.

[0487] Apart from the compounds of the formulae I, IIA, IIB, IIC and / or IID, IVa, IVb and V, the mixtures according to the invention preferably comprise one or more of the compounds mentioned below.

[0488] The following abbreviations are used: (n, m, k and l are each independently an integer, preferably 1 to 9, preferably 1 to 7, and k and l may be 0, preferably 0 to 4, more preferably 0 or 2, most preferably 2; n is preferably 1, 2, 3, 4 or 5; in the combination "-nO-", it is preferably 1, 2, 3 or 4, more preferably 2 or 4; m is preferably 1, 2, 3, 4 or 5; in the combination "-Om", it is preferably 1, 2, 3 or 4, more preferably 2 or 4. The combination "-lVm" is preferably "2V1".)

[0489]

[0490] [Table 7]

[0491] [Table 8]

[0492] [Table 9]

[0493] [Table 10]

[0494] [Table 11]

[0495] [Table 12]

[0496] [Table 13]

[0497]

Table 14

[0498]

Table 15

[0499]

Table 16

[0500]

Table 17

[0501]

Table 18

[0502]

Table 19

[0503]

Table 20

[0504]

Table 21

[0505]

Table 22

[0506]

Table 23

[0507]

Table 24

[0508] [Table 25]

[0509] [Table 26]

[0510] [Table 27]

[0511] Table E shows exemplary reactive mesogenic compounds which may be used in the LC media according to the present invention.

[0512] [Table 28]

[0513] [Table 29]

[0514] [Table 30]

[0515] [Table 31]

[0516] [Table 32]

[0517] [Table 33]

[0518]

Table 34

[0519]

Table 35

[0520]

Table 36

[0521]

Table 37

[0522]

Table 38

[0523]

Table 39

[0524]

Table 40

[0525]

Table 41

[0526]

Table 42

[0527]

Table 43

[0528] [Table 44]

[0529] [Table 45]

[0530] [Table 46]

[0531] [Table 47]

[0532] [Table 48]

[0533] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from the polymerizable compounds of the formulae RM-1 to RM-182. Among these, the compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-4 8, 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. EXAMPLES

[0534] The invention will now be described in detail by the following non-limiting examples.

[0535] The following abbreviations and symbols are used: V0 is the capacitance threshold voltage at 20°C [V]. n e is the extraordinary refractive index at 20°C and 589 nm, n0 is the normal refractive index at 20°C and 589 nm; Δn is the optical anisotropy at 20 °C and 589 nm; ε ⊥ is the dielectric constant perpendicular to the director at 20°C and 1 kHz, ε ∥ is the dielectric constant parallel to the director at 20°C and 1 kHz, Δε is the dielectric anisotropy at 20°C and 1 kHz. cl.p., T(N,I) is the clearing point [℃], γ1 is the rotational viscosity at 20℃ [mPa s], K1 is the elastic constant for "splay" deformation at 20°C [pN], K2 is the elastic constant for "twist" deformation at 20°C [pN], K3 is the elastic constant for "bend" deformation at 20°C [pN].

[0536] Unless expressly stated otherwise, all concentrations in this application are quoted in weight percent and refer to the corresponding mixture as a whole of all solid or liquid crystal components, without solvent.

[0537] Unless explicitly stated otherwise, all temperature values ​​given in this application, such as the melting point T(C,N), the transition from the smectic (S) phase to the nematic (N) phase T(S,N) and the clearing point T(N,I), are quoted in degrees Celsius (°C). Mp is the melting point and cl.p. is the clearing point. Furthermore, C is the crystalline state, N is the nematic phase, S is the smectic phase and I is the isotropic phase. The data between these symbols represent the transition temperatures.

[0538] All physical properties are determined or have been determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck KGaA, Germany, and apply for a temperature of 20° C., with Δn being determined at 589 nm and Δε at 1 kHz, unless explicitly indicated otherwise in each case.

[0539] The term "threshold voltage" for the present invention, unless otherwise specified, relates to the capacitive threshold (V0), also known as the Freedericks threshold. Also, in the examples, and as is generally customary, the threshold voltage is set to 10% relative contrast (V 10 ) may also be indicated.

[0540] Unless stated otherwise, the process of polymerizing the polymerizable compounds in the PSA displays described above and below is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, preferably a nematic phase, most preferably at room temperature.

[0541] Unless otherwise specified, the method for preparing the test cells and the method for measuring the electro-optical properties, etc. are carried out according to the method described below or a similar method.

[0542] The display used to measure the capacitive threshold voltage consists of two plane-parallel glass outer plates spaced 25 μm apart, each with an electrode layer on its inner side and an unrubbed polyimide alignment layer on top that provides homeotropic alignment of the liquid crystal molecules.

[0543] The display or test cell used to measure the tilt angle consists of two parallel outer glass plates spaced 4 μm apart, each with an electrode layer and a polyimide alignment layer on its inner side, the two polyimide layers being rubbed anti-parallel to each other to effect a homeotropic edge alignment of the liquid crystal molecules.

[0544] Polymerizable compounds can be polymerized in a display or test cell by irradiating the display with UV light of a defined intensity for a predefined time while simultaneously applying a voltage to the display (usually 10 V to 30 V AC, 1 kHz). In the examples, unless otherwise noted, polymerization is performed using fluorescent lamps and 0 to 20 mW / cm. 2 The intensity is measured using a standard meter (Ushio Accumulate UV meter, central wavelength 313 nm).

[0545] The transmittance measurements are performed in a test cell with a fishbone electrode layout (MEL, Japan, 1 pixel fishbone electrode (ITO, 10 × 10 mm, 3 μm line / 3 μm space fishbone angle 47.7°), 3.2 μm cell gap, AF glass, tilt angle 1°).

[0546] The storage stability (LTS) in bulk of the medium according to the invention at a given temperature T bulk ) is determined by visual inspection. 2 g of the medium in question are filled into a suitable sized closed glass container (bottle) and placed in a refrigerator at a given temperature. The bottles are checked at defined time intervals for the occurrence of smectic phases or crystallization. For each material and temperature, two bottles are stored. If crystallization or the appearance of smectic phases is observed in at least one of the two corresponding bottles, the test is terminated and the time of the last inspection before the occurrence of a higher order phase is observed is recorded as the respective storage stability.

[0547] <Mixture example> Mixture examples M1-M75 and P1-P10 have the compositions and physical properties shown in the table below.

[0548] <Mixture M1>

[0549] [Table 49]

[0550] <Mixture M2>

[0551] [Table 50]

[0552] <Mixture M3>

[0553] [Table 51]

[0554] The following table summarizes the main parameters of mixtures M1-M3.

[0555] [Table 52]

[0556] It has surprisingly been found that by using compounds of formula I in a medium with negative dielectric anisotropy, a favorably low rotational viscosity (γ1) and at the same time a very low ratio γ1 / K1 can be achieved, improving the response time of the display.

[0557] <Mixture M4>

[0558] [Table 53]

[0559] <Mixture M5>

[0560] [Table 54]

[0561] <Mixture M6>

[0562] [Table 55]

[0563] <Mixture M7>

[0564]

Table 56

[0565] <Mixture M8>

[0566]

Table 57

[0567] <Mixture M9>

[0568]

Table 58

[0569] <Mixture M10>

[0570]

Table 59

[0571] <Mixture M11>

[0572]

Table 60

[0573] <Mixture M12>

[0574]

Table 61

[0575] <Mixture M13>

[0576]

Table 62

[0577] <Mixture M14>

[0578]

Table 63

[0579] <Mixture M15>

[0580]

Table 64

[0581] <Mixture M16>

[0582]

Table 65

[0583] <Mixture M17>

[0584]

Table 66

[0585] <Mixture M18>

[0586]

Table 67

[0587] <Mixture M19>

[0588]

Table 68

[0589] <Mixture M20>

[0590]

Table 69

[0591] <Mixture M21>

[0592]

Table 70

[0593] <Mixture M22>

[0594]

Table 71

[0595] <Mixture M23>

[0596]

Table 72

[0597] <Mixture M24>

[0598]

Table 73

[0599] <Mixture M25>

[0600]

Table 74

[0601] <Mixture M26>

[0602]

Table 75

[0603] <Mixture M27>

[0604]

Table 76

[0605] <Mixture M28>

[0606]

Table 77

[0607] <Mixture M29>

[0608]

Table 78

[0609] <Mixture M30>

[0610]

Table 79

[0611] <Mixture M31>

[0612]

Table 80

[0613] <Mixture M32>

[0614]

Table 81

[0615] <Mixture M33>

[0616]

Table 82

[0617] <Mixture M34>

[0618]

Table 83

[0619] <Mixture M35>

[0620]

Table 84

[0621] <Mixture M36>

[0622]

Table 85

[0623] <Mixture M37>

[0624]

Table 86

[0625] <Mixture M38>

[0626]

Table 87

[0627] <Mixture M39>

[0628]

Table 88

[0629] <Mixture M40>

[0630]

Table 89

[0631] <Mixture M41>

[0632]

Table 90

[0633] <Mixture M42> Mixture Example M42 consists of 99.98% Mixture Example M1 and 0.02% of the compound of formula ST-12b-1.

[0634] [ka]

[0635] <Mixture M43> Example Mixture M43 consists of 99.985% Example Mixture M1 and 0.015% of the compound of formula S1-1a.

[0636] [ka]

[0637] <Mixture M44> Example Mixture M44 consists of 99.98% Example Mixture M2 and 0.02% of the compound of formula S2-1a.

[0638] [ka]

[0639] <Mixture M45>

[0640] [Table 91]

[0641] <Mixture M46>

[0642] [Table 92]

[0643] <Mixture M47>

[0644] [Table 93]

[0645] <Mixture M48>

[0646]

Table 94

[0647] <Mixture M49>

[0648]

Table 95

[0649] <Mixture M50>

[0650]

Table 96

[0651] <Mixture M51>

[0652]

Table 97

[0653] <Mixture M52>

[0654]

Table 98

[0655] <Mixture M53>

[0656]

Table 99

[0657] <Mixture M54>

[0658]

Table 100

[0659] <Mixture M55>

[0660]

Table 101

[0661] <Mixture M56>

[0662]

Table 102

[0663] <Mixture M57>

[0664]

Table 103

[0665] <Mixture M58>

[0666]

Table 104

[0667] <Mixture M59>

[0668]

Table 105

[0669] <Mixture M60>

[0670]

Table 106

[0671] <Mixture M61>

[0672]

Table 107

[0673] <Mixture M62>

[0674]

Table 108

[0675] <Mixture M63>

[0676]

Table 109

[0677] <Mixture M64>

[0678]

Table 110

[0679] <Mixture M65>

[0680]

Table 111

[0681] <Mixture M66>

[0682]

Table 112

[0683] <Mixture M67>

[0684]

Table 113

[0685] <Mixture M68>

[0686]

Table 114

[0687] <Mixture M69>

[0688]

Table 115

[0689] <Mixture M70>

[0690]

Table 116

[0691] <Mixture M71>

[0692]

Table 117

[0693] <Mixture M72>

[0694]

Table 118

[0695] <Mixture M73>

[0696]

Table 119

[0697] <Mixture M74>

[0698]

Table 120

[0699] <Mixture M75>

[0700]

Table 121

[0701] <Mixture M76>

[0702]

Table 122

[0703] <Mixture M77>

[0704]

Table 123

[0705] <Mixture M78>

[0706]

Table 124

[0707] <Mixture M79>

[0708]

Table 125

[0709] <Mixture M80>

[0710]

Table 126

[0711] <Mixture M81>

[0712]

Table 127

[0713] <Mixture M82>

[0714]

Table 128

[0715] <Mixture M83>

[0716]

Table 129

[0717] <Mixture M84>

[0718]

Table 130

[0719] <Mixture M85>

[0720]

Table 131

[0721] <Mixture M86>

[0722]

Table 132

[0723] <Mixture M87>

[0724]

Table 133

[0725] <Mixture M88>

[0726]

Table 134

[0727] <Mixture M89>

[0728] [Table 135]

[0729] <Mixture M90>

[0730] [Table 136]

[0731] <Mixture M91>

[0732] [Table 137]

[0733] <Mixture M92>

[0734] [Table 138]

[0735] <Polymerizable mixture> 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 formula RM-1, RM-17, RM-35, RM-64 and RM-171 in the amount given in Table 1 (% RM).

[0736] [ka]

[0737] [ka]

[0738] Table 1: Polymerizable mixture

[0739] [Table 139]

[0740] <Mixture example P10> 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 Irganox® 1076 and 0.015% of the compound ST-3a-1.

[0741] [ka]

Claims

1. a) A liquid crystal medium comprising one or more compounds of formula I, and b) one or more compounds selected from the group of compounds of formulas IIA, IIB, IIC, and IID. 【Chemistry 1】 (In the formula, R １ and R ２ This represents the same or different H, halogen, linear alkyl or alkoxy having 1 to 15 carbon atoms, linear alkenyl or alkenyloxy having 2 to 15 carbon atoms, or branched alkyl or alkoxy or alkenyl or alkenyloxy having 3 to 15 carbon atoms, provided that one or more CH groups are present in these groups. ２ The group is designed so that the oxygen atoms are not directly bonded to each other. 【Chemistry 2】 -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, -O-, -CO-O-, or -O-CO- may be substituted for each other independently, and one or more H atoms in the group may be replaced by halogens. A ０ 、 A １ and A ２ are each, independently of one another, phenylene-1,4-diyl (in which one or two CH groups in the group may be replaced by N, and one or more H atoms are halogen, CN, CH ３ , CHF ２ , CH ２ F, CF ３ , OCH ３ , OCHF ２ or OCF ３ and may be replaced. ), cyclohexane-1,4-diyl (in which one or two non-adjacent CH ２ 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 １ and Z ２ Each of them independently of the other is -CF ２ O-, -OCF ２ -ien-CH ２ O-, -OCH ２ -, -CO-O-, -O-CO-, -C ２ H ４ -, -C ２ F ４ -, -CF ２ CH ２ -ien-CH ２ CF ２ -, -CFHCFH-, -CFHCH ２ -ien-CH ２ CFH-, -CF ２ CFH-, -CFHCF ２ -, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C- or single bond, m represents 0, 1, 2 or 3, and n represents 0, 1, 2, or 3. 【Transformation 3】 (In the formula, R ２Ａ , R ２Ｂ , R ２Ｃ and R ２Ｄ This represents a linear alkyl or alkoxy group having the same or different H atoms, 1 to 15 C atoms, a linear alkenyl or alkenyloxy group having 2 to 15 C atoms, or a branched alkyl or alkoxy group having 3 to 15 C atoms, provided that one or more CH groups are present in these groups. ２ The group is designed so that the oxygen atoms are not directly bonded to each other. 【Chemistry 4】 -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, -O-, -CO-O-, or -O-CO- may be substituted for each other independently, and one or more H atoms in the group may be replaced by halogens. L １ , L ２ , L ３ and L ４ These are F, Cl, and CF, which are independent of each other. ３ or CHF ２ This represents, Y is H, F, Cl, CF ３ CHF ２ or CH ３ This represents, Z ２ Z ２Ｂ and Z ２Ｄ Each of them is independently bonded to the other by a single bond, -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ -ien-CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ -, -CF=CF- or -CH=CHCH ２ Represents O-, p represents 0, 1, or 2. q represents 0 or 1, and v represents an integer between 1 and 6.

2. The liquid crystal medium according to claim 1, wherein the total amount of one or more compounds selected from the group of compounds of formulas IIA, IIB, IIC, and IID is in the range of 9% to 70%.

3. The liquid crystal medium according to claim 1, wherein one or more compounds of formula I are selected from the group of compounds of formula I-1 to I-6. 【Transformation 5】 (In the formula, R １ and R ２ (where r, s, and t are independently 0, 1, 2, 3, or 4.)

4. In formulas I-1 to I-6, the basis 【Transformation 6】 A liquid crystal medium according to claim 3, representing the liquid crystal medium described in claim 3.

5. The liquid crystal medium according to claim 1, comprising one or more compounds of formula III. 【Transformation 7】 (In the formula, R ３１ and R ３２ Each represents an alkyl or alkoxy group having H and 1 to 15 C atoms independently of each other, provided that one or more CH groups are present in these groups. ２ The group is designed so that the oxygen atoms are not directly bonded to each other. 【Transformation 8】 -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, -O-, -CO-O-, or -O-CO- may be substituted for each other independently, and one or more H atoms in the group may be replaced by halogens. A ３１ Each of them appeared independently of the others. a) A 1,4-cyclohexenylene or 1,4-cyclohexylene group, with one or two non-adjacent CH groups in the group. ２ The base can be replaced with -O- or -S-. b) A 1,4-phenylene group, in which one or two CH groups may be replaced by N, or c) Groups from the group 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 This represents, However, groups a), b), and c) may be monosubstituted or polysubstituted with halogen atoms. n represents 0, 1, or 2. Z ３１ In each occurrence, -CO-O-, -O-CO-, and -CF appear independently of each other. ２ O-, -OCF ２ -ien-CH ２ O-, -OCH ２ -ien-CH ２ -ien-CH ２ CH ２ -, - (CH ２ ) ４ -, -CH=CH-CH ２ O-, -C ２ F ４ -ien-CH ２ CF ２ -, -CF ２ CH ２ -, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or single bond, and L ３１ and L ３２ each independently represents F, Cl, CF ３ or CHF ２ and (W represents O or S.)

6. The liquid crystal medium according to claim 5, wherein W in formula III represents S.

7. The liquid crystal medium according to claim 1, comprising one or more compounds of formula IV. 【Chemistry 9】 (In the formula, R ４１ This represents an unsubstituted alkyl group having 1 to 7 carbon atoms or an unsubstituted alkenyl group having 2 to 7 carbon atoms. R ４２ (This represents an unsubstituted alkyl group having 1 to 7 carbon atoms, an unsubstituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted alkenyl group having 2 to 7 carbon atoms.)

8. The liquid crystal medium according to claim 1, comprising one or more compounds of formulas IV-3-1 and IV-3-2. 【Chemistry 10】 (In the formula, "alkyl" represents an n-alkyl group having 1 to 7 carbon atoms.)

9. The liquid crystal medium according to claim 1, comprising one or more compounds of formula V. 【Chemistry 11】 (In the formula, R ５１ , R ５２ This represents an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkoxyalkyl group having 2 to 7 carbon atoms, an alkenyl group, or an alkenyloxy group. 【Chemistry 12】 This represents, Z ５１ and Z ５２ are the same or different and are -CH ２ -CH ２ -, -CH ２ -O-, -CH=CH-, -C≡C-, -COO- or a single bond, and n is either 1 or 2.

10. A liquid crystal medium according to claim 1, having a birefringence of 0.105 or greater.

11. A liquid crystal medium according to claim 1, comprising a polymerizable compound.

12. A liquid crystal display comprising the liquid crystal medium described in claim 1.

13. The liquid crystal display according to claim 12, which is a VA, IPS, FFS, PS-VA, PS-IPS, or PS-FFS type display.

14. Use of the liquid crystal medium according to claim 1 in a VA, IPS, FFS, PS-VA, PS-IPS, or PS-FFS display.

15. An energy-saving display for games, comprising the liquid crystal medium described in claim 1.

16. A method for preparing a liquid crystal medium according to claim 1, A method comprising the step of mixing one or more compounds of formula I with one or more compounds selected from the group of formulas IIA, IIB, IIC, and IID, and optionally with a polymerizable mixture or further liquid crystal compounds or additives.

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