Liquid crystal medium

Abstract

To provide a liquid crystal medium that is useful for energy-saving LC displays of the VA, IPS or FFS type and has a broad liquid crystal phase and a very high value of T(N,I).SOLUTION: A liquid crystal medium contains a compound of formula I and a compound of formula III, where R11 and R12 each represent an alkyl or the like, A1 represents a 1,4-phenylene group or the like, n represents 0, 1 or 2, Z1 represents a single bond or the like, L11 and L12 each represent F or the like, and W represents O or S.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a chiral liquid crystal (LC) medium with negative dielectric anisotropy and to its 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 highly 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 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. When a voltage is applied 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 structure. When a voltage is applied to the electrodes, this generates an electric field between the electrodes with a significant component parallel to the LC layer. This causes a reorientation of the LC molecules in the plane of the layer.

[0005] Furthermore, so-called FFS ("fringe-field switching") displays have been reported (see, in particular, SH Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, p. 1028 (Non-Patent Document 1)), which have two electrodes on the same substrate, one of which is structured in a comb shape and the other unstructured. This generates a strong so-called "fringe field", i.e., a strong electric field near the electrode edges, which generates an electric field across the cell with both a strong vertical component and a strong horizontal component. FFS displays have a low viewing angle dependence of their contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy and an alignment layer, usually a polyimide alignment layer, which provides a planar alignment for the molecules of the LC medium.

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

[0007] Further, FFS displays have been disclosed that have electrode designs and layer thicknesses similar to those of FFS displays, but that have LC medium layers with negative dielectric anisotropy rather than those with positive dielectric anisotropy (see, for example, S.H. Lee et al., Appl. Phys. Lett., Vol. 73 (No. 20), 1998, pp. 2882-2883 (Non-Patent Document 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 a smaller tilt and a higher twist alignment than LC media with positive dielectric anisotropy, resulting in higher transmittance for these displays. The displays also have 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 planar alignment of the LC molecules of the LC medium. These displays are also known as "Ultra Brightness FFS (UB-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 confined to relatively small domains within the LC cell. Disclinations, also known as tilt domains, may exist between these domains. VA displays with tilt domains have larger contrast-independent viewing angles and gray levels compared to traditional VA displays. Additionally, this type of display is easier to manufacture, and further treatment of the electrode surfaces, for example by rubbing, to achieve uniform alignment of the molecules in the switched-on state is no longer required. 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 typically achieved by electrodes with protrusions, which create a local pretilt. As a result, the LC molecules are oriented parallel to the electrode surface in different directions in different defined regions 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 reduced light transmittance. A further development of MVA uses protrusions on only one electrode side, while the opposite electrode has slits, which improves light transmittance. The slit electrode generates a non-uniform electric field within the LC cell when a voltage is applied, meaning that controlled switching is still achieved. The distance between the slits and the protrusions can be increased to further improve light transmittance, but this results in a longer response time. In so-called PVA ("patterned VA") displays, the protrusions are completely redundant in that both electrodes are structured with slits on the opposite side, which results in increased contrast and improved transparency 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, a shorter response time and an improvement in the contrast and brightness (transmission) of the display are required.

[0010] A further development are the so-called PS ("polymer sustained") or PSA ("polymer sustained alignment") type displays, for which the term "polymer stabilized" 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 polymerizable compound(s), preferably polymerizable monomeric compound(s), are added to the LC medium, which, after filling the display, is polymerized or crosslinked in situ, usually by ultraviolet photopolymerization, optionally with the application of a voltage to the electrodes of the display. The polymerization is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, usually at room temperature. The addition of polymerizable mesogens or liquid crystal compounds, also known as reactive mesogens or "RMs," to the LC mixture has proven particularly suitable.

[0011] On the other hand, the PS(A) principle is used in various conventional LC display modes. 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 an applied voltage in the case of PS-VA and PS-OCB displays, and with or without an applied voltage, preferably without an 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. However, it is also possible to make do without protrusions, for example, with only one structured electrode side, which significantly simplifies production and results in very good contrast and, at the same time, very good light transmittance.

[0012] PS-VA displays are described, for example, in European Patent Application Publication No. 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 SHKim, L.-C-Chien, Jpn.J.Appl.Phys., Vol. 43, 2004, pp. 7643-7647 (Non-Patent Document 5). A PS-IPS display is described, for example, in U.S. Pat. No. 6,177,972 (Patent Document 7) and Appl. Phys. Lett. 1999, Vol. 75 (No. 21), p. 3264 (Non-Patent Document 6). A PS-TN display is 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 pretilt-angle-inducing layer formed by the phase-separated polymerized RM, which provides an initial alignment of the LC molecules prior to the polymer stabilization step. The alignment layer is usually applied over the electrodes (if such electrodes are present) so as to contact the LC medium and induce the initial alignment of the LC molecules. The alignment layer may comprise or consist of, for example, 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, individual pixels are typically addressed by integrated nonlinear active elements such as transistors (e.g., thin film transistors ("TFTs")), while in the case of passive matrix displays, individual pixels are typically addressed by multiplexing methods as known from the prior art.

[0015] There is a continuing demand for optimization of the response time, but also the contrast and brightness (and therefore also the transmittance) of LC displays, particularly for monitor and especially television applications. Here, the PSA method can offer significant advantages: in the case of PS-VA, PS-IPS and PS-FFS displays in particular, a reduction in response time, which correlates with the pretilt and can be measured in test cells, can be achieved without any significant adverse effect 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 fabricated using the one drop filling (ODF) method. This phenomenon is also known as "ODF mura." Therefore, it would be 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, consequently, long switching times. To reduce the viscosity and switching time of LC media, the prior art suggests adding LC compounds with alkenyl groups. However, LC media containing alkenyl compounds have often been observed to exhibit reduced reliability and stability, as well as a decrease in VHR, especially after exposure to UV radiation. In particular, photopolymerization of RMs in PSA displays is typically achieved by exposure to UV radiation, which can cause a decrease in VHR in the LC media, which is a significant disadvantage for use in PSA displays.

[0018] Especially in terms of mobile devices, there is a great demand for displays with high transmittance, which allows for less backlight usage and therefore longer battery life, and of course brighter displays can improve contrast, especially in ambient light.

[0019] Additionally, there is a great demand for PSA displays, and LC media and polymerizable compounds for use in such PSA displays, that 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 that exhibit low threshold voltages and high birefringence. [Prior art documents] [Patent documents]

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

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

[0022] The present invention is based on the object of providing novel suitable materials in LC media containing reactive mesogens (RMs) for use in PSA displays, which do not have the disadvantages mentioned above or have them to a lesser extent. In particular, the present invention is based on the object of an LC medium containing an RM for use in PSA displays, which enables displays with high transmittance and at the same time very high resistivity, high VHR, high reliability, low threshold voltage, short response time, and high birefringence, which exhibit good UV absorption, especially at long wavelengths, which enables rapid and complete polymerization of the RM, which enables the generation of low pretilt angles, preferably as quickly as possible, and high pretilt stability even for longer periods and / or after UV exposure, which reduces or prevents the occurrence of "image sticking" and "ODF mura" in displays, and which, if polymerized as quickly and completely as possible, exhibits high solubility in the LC media typically used as host mixtures in PSA displays.

[0023] Recently, it has also been suggested that VA or PSA displays can be used for outdoor applications, such as PIDs (Public Information Displays). PIDs are one of the new paradigms emerging in the display market. PIDs are increasingly being used to display various information in public places such as stations, city streets, airports, hotels, and shopping malls.

[0024] Compared to conventional LCDs used in TVs or IT applications, PIDs are unique in that they are often installed outdoors. Therefore, compared to conventional LCDs, PIDs are required to have high durability and high reliability of the liquid crystal media used therein for stable operation under various environmental conditions, as well as a wide operating temperature range. As a result, the liquid crystal media used in PIDs have a wide liquid crystal phase range and T(N,I) (the phase transition temperature from nematic to isotropic state, also known as the "clearing temperature" or "clearing point") is very high, preferably above 100°C for this application.

[0025] However, the LC media proposed so far for use in VA or PSA displays usually have a clearing temperature T below 100 °C. (N,I) It has.

[0026] There is therefore still a great demand for PSA displays and LC media, optionally comprising polymerizable compounds, for use in FFS, VA or PSA displays, which do not exhibit the above-mentioned disadvantages or exhibit them to a lesser extent and which have improved properties. [Means for solving the problem]

[0027] These objects have been achieved in accordance with the present invention by the materials and methods described herein. It has been particularly surprising to find that the above-mentioned advantageous effects can be achieved by using a liquid crystal host as described below. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention relates to a liquid-crystalline medium comprising one or more compounds of the formula I and one, two or more compounds of the formula III.

[0029] [ka]

[0030] [ka]

[0031] During the ceremony R 31 and R 32each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that one or more CH groups in these groups are connected in such a way that the O atoms are not directly linked to each other, [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; A 3 represent, independently in each occurrence, a 1,4-phenylene group (with the proviso that one or two CH groups may be replaced by N) or a 1,4-cyclohexylene or 1,4-cyclohexenylene group (with the proviso that one or two non-adjacent CH groups may be replaced by -O- or -S-), with the proviso that said group may be mono- or polysubstituted by halogen atoms, Z 3 represent, in each occurrence independently of one another, -CF2O-, -OCF2-, -C2O-, -OCH2-, -CH2-, -CH2CH2-, -CH=CH-, -C≡C- or a single bond, preferably CHO or a single bond, L 31 and L 32 each independently of one another denotes F, Cl, CF or CHF, preferably F or Cl, very preferably F, W represents O or S, preferably S, and n represents 0, 1 or 2.

[0032] The medium may further comprise a polymerizable compound of formula R:

[0033] [ka]

[0034] In the formula, the individual radicals each independently of one another have the following meanings, which may be the same or different at each occurrence: P is a polymerizable group, Sp is a spacer group or a single bond; A 1 , A 2 is 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 is H or alkyl having 1 to 12 C atoms, R is H, L or P-Sp-; L is 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, and with the proviso that one or more H atoms may be replaced by P-Sp-, F or Cl, respectively; z is 0, 1, 2 or 3; n1 is 1, 2, 3 or 4.

[0035] The invention further relates to an LC display comprising an LC medium as defined above.

[0036] The invention further relates to an LC medium or an LC display as described above comprising one or more compounds of formula R in which the compounds of formula R are polymerized.

[0037] The present invention further relates to a method for preparing an LC medium as described above and below, which comprises mixing one or more compounds of formulae I and III, preferably with one or more compounds selected from formulae IIA, IIB, IIC and IID, and optionally with one or more compounds of formula R, and optionally with further LC compounds and / or additives.

[0038] The present invention further relates to the use of the LC medium according to the invention in PSA displays, in particular in PSA displays comprising an LC medium for the generation of a tilt angle in the LC medium by in situ polymerization of the compound(s) of formula R in the PSA display, preferably in an electric or magnetic field.

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

[0040] 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.

[0041] The present invention further relates to a liquid crystal display of the VA or PSA type, comprising two substrates, at least one of which is transparent to light, an electrode on each substrate or two electrodes on only one substrate, and an LC medium layer located between the substrates and comprising one or more polymerizable compounds and an LC component as defined above and below, with the proviso that the polymerizable compounds are polymerized between the substrates of the display.

[0042] The present invention further relates to a method for manufacturing 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 polymerizable compounds as described above and below, and optionally polymerizing the polymerizable compounds.

[0043] PSA displays according to the invention have two electrodes, preferably in the form of transparent layers, applied to one or both of the substrates. In some displays, for example PS-VA displays, one electrode is applied to each of the two substrates.

[0044] In a preferred embodiment, the polymerizable component is polymerized within the LC display while a voltage is applied to the electrodes of the display.

[0045] The polymerizable compounds of the polymerizable component are preferably polymerized by photopolymerization, very preferably by UV photopolymerization.

[0046] It has been surprisingly found that the use of the liquid crystal media according to the present invention allows for displays with improved transmittance while maintaining excellent performance with respect to process-related parameters. Specifically, in the case of PSA displays, the media exhibit rapid and complete UV photopolymerization without the addition of photoinitiators, particularly at long UV wavelengths in the 300-380 nm range, especially 320 nm or longer, resulting in rapid generation of large and stable pretilt angles, and reduced image sticking and ODF unevenness in the displays. In particular, liquid crystal host mixtures containing liquid crystal compounds having alkenyl groups exhibit high VHR values ​​after UV photopolymerization, fast response times, low threshold voltages, high birefringence, and high reliability against environmental exposure during outdoor use.

[0047] The LC media according to the invention exhibit the following advantageous properties when used in VA displays: -Improved display transmittance, High clearing temperature, High voltage holding ratio, High-speed switches, · Sufficient stability to heat and / or UV, especially when used outdoors.

[0048] The LC media according to the invention exhibit the following advantageous properties when used in PSA displays: -Improved display transmittance, High clearing temperature, Proper tilt generation within a certain process window, Fast polymerization with minimal RM residue after UV treatment High voltage retention after UV treatment, Good tilt stability, - sufficient stability against heat and / or UV, especially when used outdoors, High speed switch.

[0049] In particular, the liquid-crystalline media according to the invention exhibit an advantageously low ratio of the rotational viscosity to the splay elastic constant γ1 / K1, which contributes to improved switching behavior, especially at low driving voltages, and is useful for enabling energy-saving displays.

[0050] In formula H, aryl represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms containing 1, 2, 3 or 4 aromatic rings, including fused rings, which may be linked directly or via an alkylene linking group having 1 to 12 C atoms, with the proviso that one or more H atoms may be replaced by alkyl or alkoxy having 1 to 6 C atoms or alkenyl having 2 to 6 C atoms, or CN, CF or halogen, with the proviso that one or more CH 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-, in each case independently, such that O or S atoms are not directly linked to each other.

[0051] Preferred aryl groups are benzene, naphthalene, anthracene, biphenyl, m-terphenyl, p-terphenyl and (phenylalkyl)benzene, where aryl is a linear alkyl having 1 to 12 C atoms.

[0052] Preferably, the medium according to the invention comprises one or more compounds selected from the group of compounds of formulae IIA, IIB, IIC and IID.

[0053] [ka]

[0054] During the ceremony, R 2A , R 2B , R 2C and R 2D each independently represent H, an alkyl or alkenyl group having up to 15 C atoms, which is unsubstituted, monosubstituted with CN or CF3, or at least monosubstituted with a halogen, provided that one or more CH2 groups in these groups are -O-, -S-, ... [ka] may be replaced by -C≡C-, -CF2O-, -OCF2-, -CO-O- or -O-CO-; L 1 and L 2 each independently represents F, Cl, CF3 or CHF2, Y represents H, F, Cl, CF3, CHF2 or CH3, preferably H or methyl, very preferably H, Z 2 , Z 2B and Z 2D each independently of one another represents a single bond, -CH2CH2-, -CF2O-, -OCF2-, -CHO-, -OCH2-, -COO-, -OCO-, preferably -CHO- or a single bond, very preferably a single bond, p represents 0, 1 or 2; q represents 0 or 1, and v represents 1, 2, 3, 4, 5 or 6.

[0055] Preferred compounds of formula IIA, IIB, IIC and IID are shown below.

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] In the formula, the parameter a represents 1 or 2, and alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 carbon atoms, alkenyl represents a linear alkenyl group having 2 to 6 carbon atoms, (O) represents an oxygen atom or a single bond, preferably an oxygen atom, 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-.

[0071] Highly preferred compounds of formula IID are selected from the following sub-formulae:

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] In the formula, v represents 1, 2, 3, 4, 5 or 6.

[0079] Highly preferred compounds of formula I are compounds I-1 to I-14.

[0080] In a preferred embodiment, the medium comprises one or more compounds of formula IID-10a.

[0081] [ka]

[0082] wherein 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.

[0083] Preferred compounds of formula IID-10a are compounds IID-10a-1 to IID-10a-14.

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] Particularly preferred mixtures according to the invention comprise one or more compounds of formula 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.

[0088] Highly preferred media according to the present invention comprise one or more compounds of formula IIB-2:

[0089] [ka]

[0090] In the formula, alkyl and alkyl * each independently represent a linear alkyl group having 1 to 6 C atoms, and (O) represents an oxygen atom or a single bond, in particular compounds IIB-2-1 and IIB-2-2.

[0091] [ka]

[0092] Preferred media according to the invention comprise at least one compound of formula IIC-1, preferably in an amount of 0.5% to 5% by weight, in particular 1% to 3% by weight.

[0093] [ka]

[0094] In the formula, alkyl and alkyl * has the meaning given above.

[0095] In particular, the medium comprises one or more compounds of formula IIA-2 selected from the following sub-formulae:

[0096] [ka]

[0097] 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.

[0098] [ka]

[0099] In particular, the medium comprises one or more compounds of formula IIA-10 or IIA-52 selected from the following sub-formulae:

[0100] [ka]

[0101] 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.

[0102] [ka]

[0103] In particular, the medium comprises one or more compounds of formula IIB-10 selected from the following sub-formulae:

[0104] [ka]

[0105] 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.

[0106] [ka]

[0107] The compound of formula III is preferably selected from the compounds of formula III-1, III-2 and / or III-4.

[0108] [ka]

[0109] 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 or alkoxy group having 1 to 15 C atoms or an alkenyl group having 2 to 15 C atoms, more preferably one or both of which are an alkoxy group having 1 to 7 C atoms, L 31 and L 32 preferably represents F.

[0110] The liquid-crystalline media according to the invention preferably comprise one or more compounds of the formula III-2.

[0111] Preferably it is a compound of formula III-1 selected from the group of compounds of formulae III-1-1 to III-1-10, preferably formula III-1-6.

[0112] [ka]

[0113] [ka]

[0114] 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 represent a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represent a linear alkoxy group having 1 to 6 carbon atoms, and L 31 and L 32 each independently represents F or Cl, preferably both represent F.

[0115] Preferably, the compound of formula III-2 is selected from the group of compounds of formulae III-2-1 to III-2-10, preferably III-2-6.

[0116] [ka]

[0117] [ka]

[0118] 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 represent a linear alkenyl group having 2 to 6 carbon atoms, alkoxy and alkoxy * each independently represent a linear alkoxy group having 1 to 6 carbon atoms, and L 31 and L32 each independently represents F or Cl, preferably both represent F.

[0119] Optionally, the medium comprises one or more compounds of formula IIIA-1 and / or IIIA-2.

[0120] [ka]

[0121] In the formula, L 31 and L 32 has the same meaning as given 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, cyclopentyl or cyclopentenyl.

[0122] The compounds of formula IIIA-1 and / or IIIA-2 are contained in the medium alternatively or additionally, preferably additionally, to the compounds of formula III.

[0123] Highly preferred compounds of formula IIIA-1 and IIIA-2 are:

[0124] [ka]

[0125] In the formula, alkoxy is a linear alkoxy group having 1 to 6 carbon atoms or alternatively -(CH2) nF (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0126] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula III-3.

[0127] [ka]

[0128] 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 -C≡C-, -CF2O-, -OCF2-, -CH=CH-, so that O atoms are not directly linked to each other. [ka] may be replaced independently by -O-, -CO-O- or -O-CO-, provided that in addition one or more H atoms may be replaced by halogen.

[0129] The compound of formula III-3 is preferably selected from the group of compounds of formulae III-3-1 to III-3-10:

[0130] [ka]

[0131] [ka]

[0132] In the formula, R 32 is alkyl having 1 to 7 carbon atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl, or alternatively -(CH2) nF (wherein n is 2, 3, 4 or 5), preferably C2H4F.

[0133] 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.

[0134] [ka]

[0135] where the parameters have the meanings given above and R 31 preferably represents a linear alkyl having 1 to 7 C atoms, R 32 preferably denotes alkoxy having 1 to 7 C atoms.

[0136] 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.

[0137] [ka]

[0138] where the parameters have the meanings given above and R 31 preferably represents a linear alkyl having 1 to 7 C atoms, R 32 preferably denotes alkoxy having 1 to 7 C atoms.

[0139] In a preferred embodiment, the medium comprises one or more compounds of formula IV.

[0140] [ka]

[0141] During the ceremony, R 41represents 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 an n-alkyl group 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; However, compounds of formula I are excluded from formula IV.

[0142] The compound of formula IV is preferably selected from the group of compounds of formulae IV-1 to IV-4:

[0143] [ka]

[0144] During the ceremony, alkyl and alkyl' independently denote 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 2 to 4 C atoms, particularly preferably 2 to 3 C atoms, Alkoxy represents alkoxy having 1 to 5 C atoms, preferably 2 to 4 C atoms.

[0145] Preferably, the medium comprises one or more compounds selected from the compounds of formulae IV-1-1 to IV-1-4.

[0146] [ka]

[0147] Very preferably, the medium according to the invention comprises one or more compounds of formula IV-2-1 and / or IV-2-2.

[0148] [ka]

[0149] More preferably, the medium according to the invention comprises one or more compounds of formula IV-3:

[0150] [ka]

[0151] in which alkyl very preferably has the meaning defined above and alkenyl is [ka] wherein m is 0, 1 or 2 and n is 0, 1 or 2; In particular it is selected from the compounds of the formulae IV-3-1 to IV-3-6, very particularly preferably from the compounds of the formula IV-3-2

[0152] [ka]

[0153] Very preferably, the medium comprises in particular, in addition to the compounds of the formulae IV-3-1 to IV-3-6, one or more compounds of the formulae IV-3-7 to IV-3-9.

[0154] [ka]

[0155] Very particularly, the concentration of compounds of formulae IV-3-7 to IV-3-9 in the medium according to the invention is less than 5%, or less than 4%, or less than 3%.

[0156] Highly preferably, the medium according to the invention comprises one or more compounds of formula IV-3 and one or more compounds of formula IV-1, with the total concentration of compounds of formula IV-1 being in the range of 1% to 30%.

[0157] Very preferably, the medium according to the invention comprises a compound of the formula IV-4, in particular selected from the compounds of the formulae IV-4-1 to IV-4-3, in particular of the formula IV-4-3.

[0158] [ka]

[0159] In an 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-18.

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] In the formula, alkyl represents methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl.

[0164] The liquid-crystalline medium preferably additionally comprises one or more compounds of the formula IVa.

[0165] [ka]

[0166] During the ceremony, R 41 and R 42 each independently represent 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-.

[0167] Preferred compounds of formula IVa are shown below.

[0168] [ka]

[0169] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms.

[0170] The medium according to the invention preferably comprises at least one compound of formula IVa-1 and / or formula IVa-2.

[0171] 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.

[0172] Preferably, the medium comprises one or more compounds of formulae IVb-1 to IVb-3.

[0173] [ka]

[0174] 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 carbon atoms.

[0175] The proportion of biphenyls of the formulae IV-1 to IV-3 in the mixture as a whole is preferably at least 3% by weight, in particular less than 2% by weight.

[0176] Among the compounds of formulae IVb-1 to IVb-3, the compound of formula IVb-2 is particularly preferred.

[0177] Particularly preferred are biphenyls.

[0178] [ka]

[0179] In the formula, alkyl * represents an alkyl group having 1 to 6 C atoms, preferably n-propyl or n-butyl. The medium according to the invention particularly preferably comprises one or more compounds of the formulae IVb-1-1 and / or IVb-2-3

[0180] In a particularly preferred embodiment, the medium according to the invention comprises one or more compounds of formula V

[0181] [ka]

[0182] During the ceremony, R 51 and R 52 represents alkyl having 1 to 7 C atoms, cyclic alkyl having 3 to 12 C atoms, alkoxy having 1 to 7 C atoms, or alkoxyalkyl, alkenyl or alkenyloxy, each having 2 to 7 C atoms, [ka] Z 51 , Z 52 each independently represent -CH-CH-, -CH-O-, -CH=CH-, -C≡C-, -COO- or a single bond, and n is 1 or 2.

[0183] The compound of formula V is preferably selected from the compounds of formulae V-1 to V-17.

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] In the formula, R 51 and R 52 has 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.

[0188] Preferred media comprise one or more compounds of formula V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15 and / or V-16, very preferably V-3 or V-7.

[0189] In a preferred embodiment, the medium comprises one or more compounds selected from the compounds of formula V-7, preferably of formulae V-7a to V-7e.

[0190] [ka]

[0191] In the formula, alkyl represents an alkyl group having 1 to 7 C atoms, alkenyl represents an alkenyl group having 2 to 7 C atoms, and cycloalkyl represents a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl.

[0192] Highly preferred compounds of formulae V-7a to V-7e are selected from compounds of formulae V7-b1 to V7-b3, V-7d-1 to V-7d-8 and V-7e-1 to V-7e-12

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] [ka]

[0197] In the formula, alkyl represents ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl.

[0198] In formula V, R 51 and R 52 very preferably independently of one another denote linear alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms.

[0199] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of formula VI.

[0200] [ka]

[0201] In the formula, R 6 and R 62 is R as defined in claim 1 2A R 62 alternatively denotes F, Cl, CF3 or OCF3, preferably F, and L 61 , L 62 , L 63 , L 64 , L 65 and L 66 independently represent H or F, with the proviso that L 61 , L 62 , L 63 , L 64 , L 65 and L 66 At least one of them represents F.

[0202] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VI-1 to VI-21.

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] In the formula, R 6represents 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 6 preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0207] Particularly preferred are compounds of formulae VI-1, VI-2, VI-4, VI-20 and VI-21.

[0208] Very preferably, the medium according to the invention comprises a compound of formula IV-4, in particular a compound of formula IV-4-1.

[0209] [ka]

[0210] In the formula, R 6 and m has the meaning defined above, preferably R 6 represents methyl, ethyl, n-propyl, n-butyl, or n-pentyl, and m is 2, 3, or 4.

[0211] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of formula VIA.

[0212] [ka]

[0213] In the formula, R 6 and R 62 is R as defined in claim 1 2A R 62 alternatively represents F, Cl, CF3 or OCF3, preferably F, and L 61 , L 62 , L 63 , L 64 , L 65 and L 66independently represent H or F, with the proviso that L 61 , L 62 , L 63 , L 64 , L 65 and L 66 at least one of represents F, and Z 61 and Z 62 independently represent a single bond, -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or -CF2-O-, provided that Z 61 is Z 62 is not equal to.

[0214] Very preferably, the medium according to the invention comprises a compound of formula VIA-1 and / or formula X.

[0215] [ka]

[0216] In the formula, R 6 and m has the meaning defined above, preferably R 6 represents methyl, ethyl, n-propyl, n-butyl or n-pentyl, and m is 2, 3 or 4. In a particularly preferred embodiment, R 6 represents n-propyl, and m represents 2.

[0217] In a preferred embodiment of the invention, the medium additionally comprises one or more compounds of the formulae VII-1 to VII-9.

[0218] [ka]

[0219] [ka]

[0220] During the ceremony, R 7represents a linear alkyl or alkoxy group having 1 to 6 C atoms or a linear alkenyl group having 2 to 6 C atoms, and w is an integer of 1 to 6.

[0221] Particularly preferred are mixtures comprising at least one compound of formula V-9.

[0222] Particularly preferred are compounds of formulae VI-1, VI-2, VI-4, VI-20 and VI-21. In these compounds, R preferably represents alkyl, further alkoxy, each having 1 to 5 carbon atoms. In compounds of formula VI-20, R preferably represents alkyl or alkenyl, in particular alkyl. In compounds of formula VI-21, R preferably represents alkyl.

[0223] Further preferred embodiments are listed below.

[0224] a) A liquid-crystalline medium comprising at least one compound of the formulae Z-1 to Z-8.

[0225] [ka]

[0226] In the formula, R and alkyl have the meanings given above in formula III, and alkyl denotes a linear alkyl group having 1 to 6 C atoms.

[0227] In a preferred embodiment, the liquid crystal mixture according to the invention comprises at least one compound of the formula Z-8.

[0228] 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, compounds of the formulae N-1 to N-5.

[0229] [ka]

[0230] 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 represent -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CHO-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond.

[0231] 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 formula PH-1 and PH-2.

[0232] [ka]

[0233] 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 2 preferably independently of one another denote alkyl or alkoxy having 1 to 6 C atoms.

[0234] Particularly preferred compounds of formulae BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.

[0235] [ka]

[0236] [ka]

[0237] During the ceremony, Alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms, alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms.

[0238] Very particular preference is given to mixtures comprising one, two or three compounds of the formulae BC-2, BF-1 and / or BF-2.

[0239] d) Preferred mixtures comprise one or more indane compounds of formula In.

[0240] [ka]

[0241] During the ceremony, R 11 , R 12 and R 13 each independently represent a linear alkyl, alkoxy, alkoxyalkyl or alkenyl group having 1 to 6 C atoms, R 12 and R 13 represents alternatively a halogen, preferably F, [ka] represents i represents 0, 1 or 2.

[0242] Preferred compounds of formula In are compounds of formulae In-1 to In-16 shown below.

[0243] [ka]

[0244] [ka]

[0245] [ka]

[0246] Compounds of formulae In-1, In-2, In-3 and In-4 are particularly preferred.

[0247] e) Preferred mixtures additionally comprise one or more compounds of formulae L-1 to L-11.

[0248] [ka]

[0249] [ka]

[0250] [ka]

[0251] During the ceremony, R, R 1 and R 2 are each independently R in the above formula IIA. 2A where alkyl represents an alkyl group having 1 to 6 carbon atoms. The parameter s represents 1 or 2.

[0252] 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.

[0253] f) Preferred mixtures additionally comprise one or more compounds of formula IIA-Y.

[0254] [ka]

[0255] R in the formula 11 and R 12 is the above formula IIA and R 2A has one of the meanings given to L 1 and L 2 are the same or different and represent F or Cl, and L 3 represents H or CH3.

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

[0257] [ka]

[0258] [ka]

[0259] In the formula, alkyl and alkyl * each independently represents a linear alkyl group having 1 to 6 carbon atoms, alkoxy represents a linear alkoxy group having 1 to 6 carbon atoms, and alkenyl and alkenyl * each independently represents a linear alkenyl group having 2 to 6 carbon atoms, and O represents an oxygen atom or a single bond. * preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0260] Particularly preferred compounds of formula IIA-Y are selected from the group consisting of the following subformulae:

[0261] [ka]

[0262] In the formula, alkoxy and alkoxy * has the meaning defined above and preferably denotes methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentyloxy.

[0263] g) The medium additionally contains one or more compounds selected from the compounds of formulae P-1 to P-4.

[0264] [ka]

[0265] During the ceremony, R P represents a linear alkyl or alkoxy group having 1 to 6 C atoms or an alkenyl group having 2 to 6 C atoms, preferably alkyl, X P is linear alkyl having 1 to 6 C atoms, F, Cl, CF3, OCF2H, OCF3, OCHFCF3, OCF2CHFCF3, OCH=CF2, preferably F, OCF3 or CF3, CH3, L P1 , L P2 and L P3 each independently represents H or F.

[0266] Preferred compounds of formulas P1 to P4 are listed below.

[0267] [ka]

[0268] In the formula, R Phas the meaning given above. Preferably, R P represents alkyl or alkenyl, in particular ethyl, propyl, butyl, pentyl, 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-, and alkyl represents a straight-chain alkyl group having 1 to 6 carbon atoms.

[0269] h) In a preferred embodiment, the mixture according to claim 1 comprises at least one compound selected from the group consisting of compounds of the formulae IIA-18, IIA-42, IIA-49, IIA-51, IIA-52, IID-4, IID-10, III-3, III-4, IIIA-1-3, IVb-1, IV-b-2, VIA-1, X, V-11, V-17, Z-8 and IIA-Y.

[0270] Preferably, the medium according to the invention comprises one or more compounds of formula H:

[0271] [ka]

[0272] During the ceremony, Ar represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms, preferably 6 to 30 C atoms; Sp represents a spacer group; R S represents H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; Z S are -O-, -C(O)O-, and -(CH2) z -or-(CH2) z O-, or a single bond; HA is [ka] represents; R HH, O · , CH3, OH or OR S , preferably H or O · represents; R S1 , R S2 , R S3 and R S4 are identical or different and represent alkyl having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH3; G is H or R S or group Z S - represents HA; z is an integer from 1 to 6; and q is 3 or 4.

[0273] Compounds of formula H are described in EP-A-3354710 and EP-A-3354709.

[0274] The compound of formula H is preferably selected from the compounds of formula H-1, H-2 and H-3.

[0275] [ka]

[0276] [ka]

[0277] During the ceremony, R H has the meaning given above and preferably represents H or O; n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7; and Sp represents a spacer group, preferably alkylene having 1 to 12 C atoms in which one or more non-adjacent -CH2- groups may be replaced by -O-.

[0278] Preferred compounds of formula H-1 are selected from compounds of formula H-1-1:

[0279] [ka]

[0280] In the formula, R H has the meaning given above and preferably represents H or O; and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0281] Preferred compounds of formula H-2 are selected from compounds of formula H-2-1:

[0282] [ka]

[0283] In the formula, R H has the meaning given above and preferably represents H or O; and n2 are identical or different at each occurrence, preferably identical and are integers from 0 to 12, preferably 2, 3, 4, 5 or 6, very preferably 3; and R S are identical or different at each occurrence, preferably identical and denote alkyl having 1 to 6 C atoms, preferably n-butyl.

[0284] Preferred compounds of formula H-3 are selected from compounds of formula H-3-1:

[0285] [ka]

[0286] In the formula, R H has the meaning given above and preferably represents H or O; and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0287] Preferably, the medium according to the invention comprises a compound selected from the group of compounds of formulae ST-1 to ST-18.

[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] During the ceremony R ST represents H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that in addition, one or more CH groups in these groups are not directly linked to O atoms, and are -C≡C-, -CF2O-, -OCF2-, -CH=CH-, [ka] may be replaced independently by -O-, -CO-O-, or -O-CO-, in which one or more H atoms may additionally be replaced by halogen; [ka] may be the same or different in each occurrence, [ka] represents Z STeach independently represent -CO-O-, -O-CO-, -CF2O-, -OCF2-, -C2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-, -C2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond; L 1 and L 2 each independently represents F, Cl, CH3, CF3 or CHF2, p represents 0, 1 or 2; q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0293] Among the compounds of formula ST, particularly preferred is the compound of formula ST-3.

[0294] [ka]

[0295] [ka]

[0296] [ka]

[0297] 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.

[0298] Very particularly preferred mixtures according to the invention comprise one or more stabilizers from the group of the compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12.

[0299] [ka]

[0300] [ka]

[0301] The compounds of the formulae ST-1 to ST-19 are preferably present in the liquid crystal mixtures according to the invention in an amount of 0.005 to 0.5% each, based on the mixture.

[0302] If the mixture according to the invention comprises two or more compounds from the group of compounds of formulae ST-1 to ST-18, the concentrations increase correspondingly to 0.01 to 1% for two compounds, based on the mixture.

[0303] However, the total proportion of compounds of the formulae ST-1 to ST-18, based on the mixture according to the invention, preferably does not exceed 2%.

[0304] The medium according to the invention preferably has a negative dielectric anisotropy. In a preferred embodiment, the medium additionally comprises one or more compounds selected from the compounds of the formulae PI and PII, which preferably have a positive dielectric anisotropy.

[0305] The medium according to the invention preferably comprises one or more compounds selected from the group of compounds of formulae PI and PII.

[0306] [ka]

[0307] During the ceremony, R 2 and R 3 is H, an alkyl or alkenyl group having 1 to 12 C atoms (provided that one or more CH groups in these groups are not directly linked to the O atoms, [ka] -O-, -CO-O- or -O-CO-, provided that one or more H atoms may be replaced by halogen), preferably alkyl having 1 to 7 C atoms, alkenyl having 2 to 7 C atoms or cyclic alkyl having 3 to 9 C atoms (provided that one or more H atoms may be replaced by F), [ka] are independent of each other, [ka] represents L 21 , L 22 , L 31 and L 32 each independently represents H or F, Y 2 and Y 3 are the same or different and represent H or CH3, X 2 and X 3 each independently represent a halogen, a halogenated alkyl or alkoxy having 1 to 3 C atoms or a halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, preferably F, Cl, CF3, OCF3 or OCHF2, more preferably F or OCF3, Z 3 represents -CH2CH2-, -CF2CF2-, -COO-, trans-CH=CH-, trans-CF=CF-, -CHO- or a single bond, and l, m, n, and o are each independently 0 or 1, with the proviso that compounds of formula I are excluded from formula III.

[0308] Preferably, the medium comprises one or more compounds of formula II, preferably selected from the group of compounds of formulae PI-1 to PI-3, very preferably from the group of compounds of formulae PI-1 and PI-3.

[0309] [ka]

[0310] In the formula, the occurring groups have the respective meanings given in formula II above, and in formula PI-1, the group L 23 and L 24 each independently of each other and the other parameters represents H or F, and in formula PI-2 preferably: [ka] Represents.

[0311] In formulas PI-1, PI-2 and PI-3, L 21 and L 22 or L 23 and L 24 Preferably, each of represents F.

[0312] In another preferred embodiment of formulas PI-1 and PI-2, L 21 , L 22 , L 23 and L 24 All of these represent F.

[0313] The compound of formula PI-1 is preferably selected from the group of compounds of formulae PI-1a to PI-1h:

[0314] [ka]

[0315] [ka]

[0316] In the formulae, the occurring radicals have the respective meanings given above.

[0317] In a preferred embodiment of the present invention, the medium is 21 and L 22 and / or L 23 and L 24and each are both F. In another preferred embodiment, the medium comprises one or more compounds selected from the group of compounds of formula PI-1a to PI-1h, 21 , L 22 , L 23 and L 24 and n is 0 or 1. The present invention also includes compounds selected from the group of compounds of formulas PI-1a to PI-1h, wherein all are F.

[0318] Particularly preferred compounds are of formula PI-1.

[0319] [ka]

[0320] In the formula, R 2 has the meaning given above.

[0321] Preferably, the compound of formula PI-2 is selected from the group of compounds of formula PI-2a to PI-2c.

[0322] [ka]

[0323] in which the occurring radicals each have the meaning given above, preferably L 21 and L 22 are both F.

[0324] Preferably, the compound of formula PI-3 is selected from the group of compounds of formula PI-3a to PI-3e.

[0325] [ka]

[0326] In the formulae, the occurring radicals have the respective meanings given above.

[0327] Preferably L 21 and L 22are both F, and L 23 and L 24 are both H or L 21 , L 22 , L 23 , L 24 are all F.

[0328] Particularly preferred compounds are of formula PI-3.

[0329] [ka]

[0330] In the formula, R 2 has the meaning given above.

[0331] In addition to the preferred compounds of formula II above, the medium may contain one or more compounds of formula II selected from the compounds of formulas PIA-1 to PIA-7.

[0332] [ka]

[0333] In the formula, R 2 and X 2 has the meaning given in formula II or one of the preferred meanings given above and below.

[0334] Preferred compounds are of formulae PIA-1, PIA-2 and PIA-3, and highly preferred are of formulae PIA-1 and PIA-2.

[0335] In the compounds of formulae PIA-1 to PIA-7, R 2 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or n-propyl, and X 2 preferably represents F or OCF3, very preferably F.

[0336] In another preferred embodiment of the invention, the medium comprises one or more compounds of formula III, preferably selected from the group of formulae PII-1 and PII-2, preferably formula PII-2.

[0337] [ka]

[0338] wherein the occurring groups and parameters have the respective meanings given in formula III above.

[0339] Preferably, the compound of formula PII-1 is selected from the group of compounds of formula PII-1a and formula PII-1b.

[0340] [ka]

[0341] wherein the occurring groups have the respective meanings given above, and L 33 and L 34 each independently represents H or F.

[0342] The compound of formula PII-1a is preferably selected from the group of compounds of formulae PII-1a-1 to PII-1a-6:

[0343] [ka]

[0344] In the formula, R 3 has the meaning given above.

[0345] Preferably, the compound of formula PII-2 is selected from the group of compounds of formulae PII-2a to PII-2m.

[0346] [ka]

[0347] [ka]

[0348] [ka]

[0349] wherein the occurring groups have the respective meanings given above, and L 35 and L 36 are each independently H or F.

[0350] Preferably, the compound of formula II-2a is selected from the group of compounds of formulae PII-2a-1 to PII-2a-4.

[0351] [ka]

[0352] In the formula, R 3 has the meaning given above.

[0353] The compound of formula PII-2b is preferably selected from the group of compounds of formulae PII-2b-1 and PII-2b-2, preferably of formula PII-2b-2.

[0354] [ka]

[0355] In the formula, R 3 has the meaning given above.

[0356] The compound of formula PII-2c is preferably selected from the group of compounds of formulae PII-2c-1 to PII-2c-5:

[0357] [ka]

[0358] [ka]

[0359] In the formula, R 3 has the meaning given above.

[0360] The compounds of formulae PII-2d and PII-2e are preferably selected from the group of compounds of formulae PII-2d-1 and PII-2e-1.

[0361] [ka]

[0362] In the formula, R 3 has the meaning given above.

[0363] The compound of formula PII-2f is preferably selected from the group of compounds of formulae PII-2f-1 to PII-2f-7:

[0364] [ka]

[0365] The compound of formula PII-2g is preferably selected from the group of compounds of formulae PII-2g-1 to PII-2g-7.

[0366] [ka]

[0367] In the formula, R 3 has the meaning given above.

[0368] The compound of formula PII-2h is preferably selected from the group of compounds of formulae PII-2h-1 to PII-2h-5:

[0369] [ka]

[0370] In the formula, R 3 has the meaning given above.

[0371] The compound of formula PII-2i is preferably selected from the group of compounds of formulae PII-2i-1 to PII-2i-3:

[0372] [ka]

[0373] In the formula, R 3 has the meaning given above.

[0374] The compound of formula PII-2j is preferably selected from the group of compounds of formulae PII-2j-1 to PII-2j-3.

[0375] [ka]

[0376] In the formula, R 3 has the meaning given above.

[0377] The compound of formula PII-2k is preferably selected from the group of compounds of formulae PII-2k-1 to PII-2k-6.

[0378] [ka]

[0379] In the formula, R 3 has the meaning given above.

[0380] The compound of formula PII-2l is preferably selected from the group of compounds of formulae PII-2l-1 to PII-2l-6:

[0381] [ka]

[0382] In the formula, R 3 has the meaning given above.

[0383] The compound of formula PII-2m is preferably selected from the group of compounds of formula PII-2m-1:

[0384] [ka]

[0385] Alternatively or in addition to the compounds of formula PII-1 and / or PII-2, the medium according to the invention optionally comprises one or more compounds of formula PII-3.

[0386] [ka]

[0387] wherein the groups and parameters have the respective meanings given in Formula III above.

[0388] Preferably, it is of formula PII-3a.

[0389] [ka]

[0390] In the formula, R 3 has the meaning given above.

[0391] In addition to the preferred compounds of formula III above, the medium optionally comprises one or more compounds selected from the group consisting of formulae PIA-1 to PIA-21.

[0392] [ka]

[0393] [ka]

[0394] [ka]

[0395] [ka]

[0396] In the formula, R 3 and X 3 has the meaning given in formula III or one of the preferred meanings given above and below. Preferred compounds are those of the formulae PIA-1, PIA-4, PIA-6, PIA-16, PIA-19 and PIA-20.

[0397] In the compounds of formulae PIA-1 to PIA-21, R 3 preferably denotes alkyl having 1 to 6 C atoms, very preferably ethyl or propyl, and X 3 preferably represents F or OCF3, very preferably F.

[0398] The term "reliability" as used herein refers to the quality of a display's performance over time under different stress loads, such as light load, temperature, humidity, voltage, and other display effects known to those skilled in the art of liquid crystal displays, such as image sticking (area and line image sticking), mura, and smearing. As a standard parameter for classifying reliability, the voltage holding ratio (VHR) value is usually used, which is a measure of the ability of a test display to maintain a constant electrical voltage. A high VHR is a prerequisite for a reliable LC medium.

[0399] Unless otherwise specified, the term "PSA" will be used hereinafter to refer to polymer-sustained alignment displays in general, and the term "PS" will be used to refer to specific display modes such as PS-VA and PS-TN.

[0400] In the following description, unless otherwise specified, the term "RM" will be used to refer to a polymerizable mesogenic compound or a liquid crystal compound.

[0401] 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.

[0402] As used herein, the terms "tilt" and "tilt angle" are understood to mean the tilted orientation of the LC molecules of the LC medium in an LC display (herein preferably a PSA display) relative to the cell surface. As used herein, tilt angle means the average angle (less than 90°) between the molecular long axis (LC director) of the LC molecules and the surfaces of the flat, parallel outer plates forming the LC cell. As used herein, low values ​​of tilt angle (i.e., large deviations from the 90° angle) correspond to large tilt. A suitable method for measuring tilt angle is given in the examples. Unless otherwise indicated, the tilt angle values ​​disclosed above and below refer to this measurement method.

[0403] As used herein, the terms "reactive mesogen" and "RM" are understood to mean a compound containing a mesogenic or liquid crystalline backbone and one or more functional groups attached to the backbone that are suitable for polymerization, which functional groups are also referred to as "polymerizable groups" or "P".

[0404] Unless otherwise stated, as used herein, the term "polymerizable compound" is understood to mean a polymerizable monomeric compound.

[0405] 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.

[0406] As used herein, the term "non-polymerizable compound" is understood to mean a compound that does not contain functional groups suitable for polymerization under conditions normally applied for the polymerization of RMs.

[0407] As used herein, the term "mesogenic group" is known to those skilled in the art and described in the literature and refers to a group that, due to the anisotropy of its attractive and repulsive interactions, essentially contributes to the generation of a liquid crystal (LC) phase in low-molecular-weight or polymeric materials. A compound containing a mesogenic group (mesogenic compound) does not necessarily have an LC phase by itself. It is also possible for a mesogenic compound to exhibit LC phase behavior only after mixing with other compounds and / or polymerization. Typical mesogenic groups are, for example, rigid rod- or disc-shaped units. A review of terms and definitions used in connection with mesogens or LC compounds is given in Pure Appl. Chem. 2001, Vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, Vol. 116, pp. 6340-6368.

[0408] 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."

[0409] As used herein, the term "spacer group", hereinafter also referred to as "Sp", is known to those skilled in the art and described in the literature, see, for example, Pure Appl. Chem. 2001, vol. 73 (No. 5), p. 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, vol. 116, pp. 6340-6368. As used herein, the term "spacer group" or "spacer" refers to a flexible group, such as an alkylene group, that connects a mesogenic group and a polymerizable group(s) in a polymerizable mesogenic compound.

[0410] Above and below, [ka] represents a trans-1,4-cyclohexylene ring.

[0411] basis [ka] The single bond shown between two ring atoms in can be attached to any free position on the benzene ring.

[0412] Above and below, "organic group" represents a carbon or hydrocarbon group.

[0413] The term "carbon group" refers to a monovalent or polyvalent organic group containing at least one carbon atom, provided that it either contains no additional atoms (e.g., -C≡C-) or it may contain one or more additional atoms (e.g., carbonyl) such as, for example, N, O, S, B, P, Si, Se, As, Te, or Ge. 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.

[0414] "Halogen" represents F, Cl, Br or I, preferably F or Cl.

[0415] -CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e., [ka] Represents.

[0416] The carbon or hydrocarbon group may be saturated or unsaturated. Unsaturated groups are, for example, aryl, alkenyl, or alkynyl groups. The carbon or hydrocarbon group having more than three carbon atoms may be linear, branched, and / or cyclic, and may contain spiro-linked or fused rings.

[0417] The terms "alkyl," "aryl," "heteroaryl," etc. also encompass polyvalent groups such as alkylene, arylene, heteroarylene, etc.

[0418] 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).

[0419] In the present specification, alkyl is linear or branched and has 1 to 15 C atoms, preferably linear, and, unless otherwise specified, has 1, 2, 3, 4, 5, 6 or 7 C atoms, and is accordingly preferably methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

[0420] As used herein, branched alkyl refers to alkyl having secondary and / or tertiary, preferably secondary, carbon atoms, and is preferably isopropyl, s-butyl, isobutyl, isopentyl, 2-methylhexyl or 2-ethylhexyl, 2-methylpropyl, 2-pentyl, 3-pentyl, 2-methylbutyl, 3-methylbutyl.

[0421] In this specification, the term "cyclic alkyl group" refers to an alicyclic group or an alkyl group in which a methylene group is substituted with an alicyclic group (i.e., cycloalkylalkyl or alkylcycloalkylalkyl), which may be saturated or partially unsaturated, and preferably represents cyclopropyl, methylcyclopropyl, cyclobutyl, methylcyclobutyl, cyclopentyl, methylcyclopentyl, cyclopent-1-enyl, cyclopropylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentoylethyl, or cyclopent-1-enylmethyl.

[0422] In this specification, alkoxy groups are linear or branched and contain 1 to 15 C atoms, preferably linear and, unless otherwise indicated, have 1, 2, 3, 4, 5, 6 or 7 C atoms and are accordingly preferably methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, n-hexoxy or n-heptoxy.

[0423] In this specification, the alkenyl group is preferably an alkenyl group having 2 to 15 carbon atoms, linear or branched, and containing at least one C-C double bond. It is preferably linear and has 2 to 7 carbon atoms. Therefore, it is preferably vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, or hept-1-, -2-, -3-, -4-, -5- or -6-enyl. If two carbon atoms of the C-C double bond are substituted, the alkenyl group may be in the form of an E and / or Z isomer (trans / cis). Generally, the respective E isomers are preferred. Of the alkenyl groups, prop-2-enyl, but-2- and -3-enyl and pent-3- and -4-enyl are particularly preferred.

[0424] In the present specification, alkynyl is understood to mean an alkynyl radical having 2 to 15 C atoms, which is linear or branched and contains at least one C-C triple bond. 1- and 2-propynyl and 1-, 2- and 3-butynyl are preferred.

[0425] 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.

[0426] 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.

[0427] C1~C 12 Alkyl, C2-C 12 Alkenyl, C2-C 12 Alkynyl, C6-C 25 Aryl and C2-C 25 Heteroaryl is particularly preferred.

[0428] 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, provided 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-.

[0429] 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-, and 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.

[0430] 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.

[0431] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, and the like.

[0432] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, and the like.

[0433] 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.

[0434] Preferred amino groups include, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, and the like.

[0435] Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e., they can contain one ring (e.g., phenyl) or two or more rings, and the groups can be fused (e.g., naphthyl) or covalently linked (e.g., biphenyl) or contain a combination of fused and linked rings. Heteroaryl groups preferably contain one or more heteroatoms selected from O, N, S, and Se.

[0436] Particularly preferred are mono-, bi- or tricyclic aryl groups having 6 to 25 C atoms and mono-, bi- 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.

[0437] 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.

[0438] 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, prilus benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoiazole, naphthimidazole, phenanthroimidazole, pyridimidazole, 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, benzoiazole fused 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 combinations of these groups.

[0439] 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.

[0440] (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.

[0441] (Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e., containing only one ring (e.g., cyclohexane), or polycyclic, i.e., containing multiple 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 CH groups may be replaced by -O- and / or -S-.

[0442] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, and pyrrolidine; 6-membered groups such as cyclohexane, silynan, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, and 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, and octahydro-4,7-methanoindan-2,5-diyl.

[0443] Preferred substituents are solubility-promoting groups such as 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 t-butyl or optionally substituted aryl groups.

[0444] Preferred substituents are hereinafter referred to 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 (provided that 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.

[0445] 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.

[0446] "Substituted silyl or aryl" preferably includes 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.

[0447] 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.

[0448] A 1 and A 2 is 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.

[0449] Throughout this patent application, 1,4-cyclohexylene rings and 1,4-phenylene rings are represented as follows: [ka]

[0450] The cyclohexylene ring is a trans-1,4-cyclohexylene ring.

[0451] 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 groups suitable for ring-opening polymerization, such as, for example, oxetane or epoxide groups, are particularly preferred.

[0452] The preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, [ka] CH2=CW 2 -(O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -, HS-CW 2 W 3 -, HW 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si—, wherein W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, and 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 carbon atoms, W 7 and W 8each independently represent H, Cl or alkyl having 1 to 5 C atoms; Phe represents 1,4-phenylene which may be substituted by one or more groups L as defined above other than P-Sp-; k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0453] A highly preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, [ka] CH2=CW 2 -O-, CH2=CW 2 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=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 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, and 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 6each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 carbon atoms, W 7 and W 8 each independently represent H, Cl or 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.

[0454] 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] is selected from the group consisting of:

[0455] 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.

[0456] When the spacer group Sp is different from a single bond, Sp is preferably of the formula Sp"-X" so that each group P-Sp- corresponds to the formula R-Sp"-X"-, where Sp" and X" have the following meanings:

[0457] Sp" represents a linear or branched alkylene group 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.

[0458] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, or -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 00 - or a single bond.

[0459] 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 of 1 to 12, q1 is an integer of 1 to 3, and R 0 and R 00 has the meaning given above.

[0460] 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.

[0461] 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.

[0462] In a preferred embodiment of the invention, compounds of formula P and its subformulas have the group Sp-P as Sp(P) s (where s is 2 or more) and contains a spacer group Sp (branched polymerizable group) substituted with one or more polymerizable groups P so as to correspond to the above.

[0463] Preferred compounds of formula R 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 R according to this preferred embodiment contain a group selected from the following formulae:

[0464] [ka]

[0465] wherein P has the meaning as defined in formula R; alkyl represents 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, provided that one or more non-adjacent CH groups are each independently connected to one another in such a way that O and / or S atoms are not directly linked to one another, -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.

[0466] Preferred spacer groups Sp(P)2 are selected from formulae S1, S2 and S3.

[0467] Highly preferred spacer groups Sp(P)2 are selected from the following sub-formulae:

[0468] [ka]

[0469] In the compounds of formula R 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.

[0470] Further preferred are compounds of formula R and its sub-formulae as above and below, in which all polymerizable groups P present in the compound have the same meaning, very preferably acrylate or methacrylate, most preferably methacrylate.

[0471] In the compounds of formula R and its subformulae above and below, R preferably represents P-Sp.

[0472] 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 R and its subformulae as above and below, in which the O atom or CO group, respectively, is linked to a benzene ring.

[0473] Further preferred are compounds of formula R and subformulae thereof as defined above and below, in which at least one group Sp is a single bond.

[0474] 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 R and its subformulae as above and below, in which the O atom or CO group, respectively, is linked to a benzene ring.

[0475] Highly preferred group -A in formula R 1 -(ZA 2 ) z is selected from the following formulas:

[0476] [ka]

[0477] 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-.

[0478] Preferred compounds of formula R and their sub-formulas 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 the group P). ·P is selected from the group consisting of acrylates, methacrylates and oxetanes, and is very preferably 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 connected 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 connected to the benzene ring. ·R represents P-Sp-. R does not represent or contain a polymerizable group. R does not represent or contain a polymerizable group and represents a linear, branched or cyclic alkyl having 1 to 25 C atoms, provided 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, and provided that one or more H atoms are replaced by F, Cl or L a may be replaced by L or L' represents F, Cl or CN. ·L is F.

[0479] Suitable and preferred compounds of formula R are selected from the following formulae:

[0480] [ka]

[0481] [ka]

[0482] [ka]

[0483] [ka]

[0484] [ka]

[0485] [ka]

[0486] wherein the individual groups have the following meanings: P 1 , P 2 and P 3 each independently represents an acrylate or methacrylate group, Sp 1 , Sp 2 and Sp 3 each independently of one another represents 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-, wherein 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 independently be 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 represents a linear or branched, optionally monofluorinated or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, 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 in 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-, -CHO-, -OCH-, -CFO-, -OCF- or -(CH) 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 group having 1 to 12 carbon atoms, which may be linear or branched and monofluorinated or polyfluorinated, 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.

[0487] Compounds of formula R2, R13, R17, R22, R23, R24, R30, R31 and R32 are particularly preferred.

[0488] Furthermore, trireactive compounds R15 to R30, particularly R17, R18, R19, R22, R23, R24, R25, R26, R30, R31 and R32 are preferred.

[0489] In the compounds of formulas R1 to R32, the group [ka]

[0490] wherein L, identically or differently, in each occurrence has 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.

[0491] To produce a PSA display, polymerizable compounds contained in the LC medium are polymerized or crosslinked (if one 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.

[0492] The structure of the PSA display according to the present invention corresponds to the usual configuration of PSA displays as described in the prior art cited at the beginning. A configuration without protrusions is preferred, in particular one in which the electrode on the color filter side is unstructured 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 Patent Application Publication No. 2006 / 0066793.

[0493] 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, and an optional second alignment layer, which may be disposed on the entire portion of the second substrate facing the first substrate; an LC layer disposed between a first substrate and a second substrate, the LC layer comprising an LC medium layer comprising a polymerizable component comprising one or more compounds of formula R and a chiral nematic liquid crystal host, including those described above and below, where the polymerizable component may be polymerized; Includes:

[0494] The first and / or second alignment layers control the alignment direction of the LC molecules in the LC layer. For example, in a PS-VA display, the alignment layers are selected to align the LC molecules in a homeotropic (or vertical) orientation (i.e., perpendicular to the surface) or tilted orientation. Such alignment layers can comprise, for example, polyimides, which may be rubbed or prepared by photoalignment.

[0495] The LC layer with the LC medium can be placed between the substrates of the display by methods commonly used in display manufacturing, such as the so-called one-drop-filling (ODF) method. The polymerizable components of the LC medium are then polymerized, for example by UV photopolymerization. Polymerization can be carried out in one step or in two or more steps.

[0496] PSA displays may include additional elements such as color 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.

[0497] The electrode structure can be designed by those skilled in the art depending on the type of display, for example, to generate two, four or more different tilt alignment directions for PS-VA displays, electrodes with slits and / or ridges or protrusions can be provided to induce multi-domain alignment of the LC molecules.

[0498] Upon polymerization, the polymerizable compound forms a crosslinked polymer, which induces a certain pretilt of the LC molecules in the LC medium. Without wishing to be bound by any particular theory, it is believed that at least a portion of the crosslinked polymer formed by the polymerizable compound phase-separates or precipitates from the LC medium, forming a polymer layer on the substrate or electrode or an alignment layer provided thereon. Microscopic measurement data (e.g., SEM and AFM) confirmed that at least a portion of the formed polymer accumulates at the LC / substrate interface.

[0499] 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 in which the compounds that did not react in the first step are polymerized or crosslinked without the application of a voltage ("final cure").

[0500] Suitable and preferred methods of polymerization are, for example, thermal or photopolymerization, preferably photopolymerization, especially UV-induced photopolymerization, which can be achieved by exposing the photopolymerizable compound to UV radiation.

[0501] One or more polymerization initiators can be added to the LC medium. Suitable polymerization conditions and the appropriate type and amount of initiator are known to those skilled in the art and are 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.

[0502] The polymerizable compound according to the present invention is also suitable for polymerization without initiator, which has significant advantages, such as lower material costs and, in particular, less contamination of the LC medium by residual amounts 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 a polymerization initiator.

[0503] The LC medium may also contain one or more stabilizers, for example, to prevent undesired spontaneous polymerization of the RM during storage or transportation. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Commercially available stabilizers, such as Irganox® 1076 from the Irganox® series (Ciba), are particularly suitable. When a stabilizer is used, 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 A).

[0504] The polymerizable compounds of formula I exhibit particularly good UV absorption and are therefore particularly suitable for methods of preparing PSA displays 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 that of conventional UV lamps) in the absorption spectrum of 300 to 380 nm and are preferably used in the UV2 process, but can also be used in the UV1 process if high intensities need to 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 generated by a UV lamp with an emission spectrum shifted to longer wavelengths (preferably 340 nm or longer).

[0505] Either using lower intensity or shifting to longer wavelength UV protects the organic layers from damage that can be caused by UV light.

[0506] Preferred embodiments of the present invention relate to methods for preparing the PSA displays 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 a 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.

[0507] This preferred method can be carried out, for example, by using a desired UV lamp or a bandpass filter and / or cutoff filter that substantially transmits UV light having the desired wavelength and substantially blocks light having undesired wavelengths. 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 greater than 300 nm and less than 400 nm. If irradiation with UV light having a wavelength λ greater than 340 nm is desired, UV exposure can be carried out using a cutoff filter that substantially transmits wavelengths λ greater than 340 nm.

[0508] "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 λ range, and in the case of a cutoff filter, wavelengths above (below) a given λ value.

[0509] This preferred method allows for the manufacture of displays using longer wavelength UV, thereby reducing or avoiding the harmful and damaging effects of the short wavelength component of UV light.

[0510] The UV irradiation energy is generally 6 to 100 J, depending on the conditions of the manufacturing process.

[0511] Preferably, the LC medium according to the present invention consists essentially of a polymerizable component P) comprising a polymerizable compound of formula R or one or more polymerizable compounds of formula R as described above and below, 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 list including, but not limited to, 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.

[0512] The LC media according to the invention may comprise one, two or three chiral dopants, very preferably one chiral dopant.

[0513] Particular preference is given to LC media which comprise one, two or three polymerisable compounds of the formula R. Further preference is given to LC media which have a chiral nematic LC phase.

[0514] Preferably the proportion of compounds of formula R in the LC medium is greater than 0% and less than 5%, very preferably greater than 0% and less than 1%, most preferably between 0.01 and 0.5%.

[0515] Preferred embodiments, alone or in combination with one another, are listed below: The medium according to the invention preferably comprises:

[0516] A compound of formula I in a concentration ranging from 5% to 35%, preferably from 10% to 30%, very preferably from 15% to 25%.

[0517] one, two, three or more compounds of formula III in a total concentration ranging from 5% to 25%, more preferably from 6% to 20%, very preferably from 7% to 18%, in particular from 9% to 15%.

[0518] one or more compounds of formula III-3 in a total concentration ranging from 2% to 15%, more preferably from 4% to 14%, very preferably from 5% to 12%.

[0519] one or more compounds of formula III-1 and / or III-2, preferably III-2, and formula III-3, in a total concentration ranging from 5% to 25%, more preferably from 7% to 20%, very preferably from 10% to 18%.

[0520] one or more compounds of formula IIA in a total concentration ranging from 1% to 50%, more preferably from 5% to 35%, very preferably from 7% to 30% or from 10% to 30%.

[0521] one or more compounds of formula IIA-2 in a total concentration ranging from 5% to 35%, more preferably from 6% to 30%, very preferably from 7% to 28%.

[0522] One or more compounds of formula IIA-10 in a total concentration ranging from 2% to 20%, more preferably from 4% to 15%, and very preferably from 5% to 13%.

[0523] One or more compounds of formula IIB, preferably compounds of formula IIB-2 and / or IIB-10, in a total concentration ranging from 2% to 30%.

[0524] one or more compounds of formula IIB-2 in a total concentration ranging from 15% to 40%, more preferably from 17% to 35%, very preferably from 19% to 33%.

[0525] one or more compounds of formula IIA-2 and one or more compounds of formula IIB-2 in a combined concentration ranging from 10% to 30%, more preferably from 11% to 28%, very preferably from 12% to 24%.

[0526] one or more compounds of formula IIC in a total concentration ranging from 1% to 15%, more preferably from 2% to 13%, and very preferably from 3% to 12%.

[0527] One or more compounds of formula IID, more preferably IID-10, in a total concentration ranging from 10% to 40%, more preferably from 15% to 35%, very preferably from 19% to 32%.

[0528] one or more compounds of formula IIA and one or more compounds of formula IIB in a total concentration ranging from 15% to 45%, more preferably from 18% to 42%, very preferably from 20% to 40%.

[0529] one or more compounds of formula IIA and one or more compounds of formula IID in a total concentration ranging from 15% to 45%, more preferably from 18% to 42%, very preferably from 20% to 40%.

[0530] one or more compounds of formula IIB and one or more compounds of formula IID in a total concentration ranging from 15% to 35%, more preferably from 20% to 32%, very preferably from 22% to 30%.

[0531] one or more compounds of formula IIA and one or more compounds of formula IIB and one or more compounds of formula IIC and one or more compounds of formula IID in a total concentration in the range of 40% to 70%, more preferably 45% to 65%, very preferably 50% to 60%.

[0532] one or more compounds of formula III and one or more compounds selected from formulae IIA, IIB, IIC and IID in a total concentration ranging from 40% to 70%, more preferably from 45% to 65%, very preferably from 50% to 60%.

[0533] one or more compounds of formula I and one or more compounds of formula IV-3-2 in a total concentration ranging from 15% to 40%, more preferably from 22% to 38%, very preferably from 25% to 35%.

[0534] one or more compounds of formula I and one or more compounds selected from formulae IV, IVa and IVb in a total concentration ranging from 20% to 60%, more preferably from 28% to 55%, very preferably from 32% to 50%.

[0535] one or more compounds of formula I and one or more compounds selected from formula IV, IVa and IVb and one or more compounds of formula V in a total concentration ranging from 35% to 70%, more preferably from 40% to 65%, very preferably from 45% to 60%.

[0536] Contains one or more compounds of formulae IV-3-6, IV-3-7 and IV-3-8, preferably IV-3-6, in a total concentration of less than 30%, preferably less than 25%, more preferably less than 24% or less than 23% or less than 22%.

[0537] Compound of formula IV-3-6, in a total concentration ranging from 0% to 5%, preferably 0%.

[0538] one or more compounds of formula IV-1 in a total concentration ranging from 1% to 30%, more preferably from 2% to 22%, very preferably from 3% to 20%.

[0539] one or more compounds of formula IV-1 in a total concentration ranging from 15% to 25%.

[0540] one or more compounds of formula IV-1 in a total concentration ranging from 7% to 13%.

[0541] one or more compounds of formula IV-1 in a total concentration ranging from 1% to 8%.

[0542] one or more compounds of formula IV-2 in a total concentration ranging from 1% to 14%, more preferably from 2% to 13%, even more preferably from 3% to 12%, very preferably from 8% to 11%.

[0543] one or more compounds of formula IVa and / or formula IVb in a total concentration ranging from 1% to 12%, more preferably from 2% to 11%, very preferably from 3% to 10%.

[0544] one or more compounds of formula V in a total concentration ranging from 3% to 30%, more preferably from 5% to 25%, very preferably from 6% to 20%.

[0545] one or more compounds of formula V-10 in a total concentration ranging from 1% to 25%, more preferably from 3% or 5% or from 7% to 22%, even more preferably from 10% to 20%, very preferably from 13% to 18%.

[0546] One or more compounds of formula V-16 in a total concentration ranging from 1% to 12%, more preferably from 3% to 11%, even more preferably from 5% to 10%, and very preferably from 6% to 9%.

[0547] one or more compounds of formula PI-3, preferably of formula PI-3a, very preferably of formula PI-3a-2, preferably in a concentration in the range of 0.05% to 1%, more preferably 0.1% to 0.8%, in particular 0.2% to 0.4%.

[0548] one or more compounds of the formula PII-2, preferably of the formula PII-2m, very preferably of the formula PII-2m-1, preferably in a concentration in the range of 0.05% to 3%, more preferably 0.1% to 2%, in particular 0.5% to 1.5%.

[0549] Particularly preferred mixture concepts are given below (the acronyms used are explained in Tables A to D, where n and m each independently represent 1 to 6):

[0550] The mixture according to the invention preferably comprises:

[0551] PYP-nm, especially PYP-2-3 and / or PYP-2-4, preferably in a concentration of more than 5%, especially between 8 and 30%, based on the total mixture.

[0552] and / or CPY-n-Om, especially CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably at a concentration of more than 5%, especially 10-30%, based on the mixture as a whole.

[0553] and / or B-nO-Om and / or B(S)-nO-Om, preferably in a concentration of 1-15.

[0554] and / or CY-n-Om, preferably CY-3-O2, CY-3-O4, CY-5-O2 and / or CY-5-O4, preferably in a concentration of more than 5%, in particular 15 to 50%, based on the total mixture.

[0555] and / or CCY-n-Om, preferably CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and / or CCY-5-O2, preferably in a concentration of more than 5%, in particular 10-30%, based on the total mixture.

[0556] and / or CLY-n-Om, preferably CLY-2-O4, CLY-3-O2 and / or CLY-3-O3, preferably at a concentration of more than 5%, in particular 10-30%, based on the mixture as a whole.

[0557] and / or LY-n-Om, preferably LY-3-O2, preferably at a concentration of more than 5%, in particular 10-30%, based on the total mixture.

[0558] and / or CCOY-n-Om, preferably CCOY-3-O2, preferably at a concentration of more than 5%, in particular 10-30%, based on the total mixture.

[0559] and / or CLOY-n-Om, preferably CLOY-3-O2, preferably at a concentration of more than 5%, in particular 10-30%, based on the total mixture.

[0560] CK-nF, preferably CK-3-F, CK-4-F and / or CK-5-F, preferably in a concentration of more than 5%, in particular 5-25%, based on the total mixture.

[0561] and / or at least two compounds of the formula PY-n-Om, preferably PY-1-O2 and PY-3-O2;

[0562] Further preferred are mixtures according to the invention which include the following mixture concepts (n and m each independently represent 1 to 6):

[0563] CPY-n-Om and CY-n-Om, preferably at a concentration of 10-80% based on the total mixture.

[0564] and / or CPY-n-Om and CK-nF, preferably at a concentration of 10-70% based on the total mixture.

[0565] and / or CPY-n-Om and PY-n-Om, preferably CPY-2-O2 and / or CPY-3-O2 and PY-3-O2, preferably in a concentration of 10-40% based on the total mixture.

[0566] and / or CPY-n-Om and CLY-n-Om, preferably at a concentration of 10-80% based on the total mixture.

[0567] and / or · CC-3-V1, preferably in an amount of 3-15%.

[0568] and / or · PGIY-n-Om preferably in an amount of 3-15%.

[0569] and / or · CC-n-2V1, preferably in an amount of 3-20%.

[0570] and / or At least 20% CC-3-V1 and CC-4-V1 based on the total weight of the mixture.

[0571] and / or at least one compound of formula III-3 and at least one compound of formula III-1, or at least one compound of formula III-3 and at least one compound of formula III-2.

[0572] The liquid-crystalline media according to the invention advantageously have a nematic phase preferably at temperatures from -20°C to 70°C, particularly preferably from -30°C to 80°C, very particularly preferably from -40°C to 90°C.

[0573] In a preferred embodiment, the medium according to the invention has a clearing temperature of 70°C or higher, more preferably 72°C or higher, in particular 73°C or higher.

[0574] In another preferred embodiment the medium according to the invention has a clearing temperature of 85°C or higher, more preferably 90°C or higher, in particular 92°C or higher.

[0575] In another preferred embodiment the medium according to the invention has a clearing temperature of 100°C or higher, more preferably 105°C or higher, very preferably 110°C or higher, in particular 112°C or higher.

[0576] The expression "having a nematic phase" means, on the one hand, that no smectic phase or crystallization is observed below the corresponding temperature, and, on the other hand, that at a given temperature, no clearing (transition to an isotropic phase) occurs upon heating of the nematic phase. Low-temperature studies are carried out using a flow viscometer at the corresponding temperature and confirmed by storage for at least 100 hours in test cells with a layer thickness corresponding to the electro-optical application. If the storage stability in the test cells at a temperature of -20°C is 1000 hours or more, the medium is said to be 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 capillary tubes using conventional methods.

[0577] The liquid crystal mixture preferably has a nematic phase range of at least 60 K and a maximum of 30 mm 2 ·Seconds -1 Flow viscosity ν20 It has.

[0578] The mixture is nematic at temperatures below -20°C, preferably below -30°C, and very preferably below -40°C.

[0579] The medium according to the invention has a birefringence in the range of 0.085 to 0.120, preferably 0.095 to 0.115, in particular 0.100 to 0.110.

[0580] In a preferred embodiment, the medium has a birefringence in the range of 0.1000 to 0.1040, preferably 0.1010 to 0.1030, in particular 0.1015 to 0.1025.

[0581] In a preferred embodiment, the medium has a birefringence in the range of 0.1005 to 0.1080, preferably 0.1020 to 0.1075, in particular 0.1035 to 0.1060.

[0582] In another preferred embodiment, the medium has a birefringence in the range of 0.1030 to 0.1090, preferably 0.1040 to 0.1080, in particular 0.1050 to 0.1080.

[0583] In another preferred embodiment, the medium has a birefringence in the range of 0.1050 to 0.1110, preferably 0.1070 to 0.1105, in particular 0.1080 to 0.1100.

[0584] In a preferred embodiment, the medium according to the invention has a dielectric anisotropy Δε of 2.5 to 5.0, preferably −2.8 to −4.8, in particular 3.0 to 4.5.

[0585] In a highly preferred embodiment, the liquid crystal mixture according to the invention has a dielectric anisotropy Δε of 3.8 to 4.2.

[0586] In another highly preferred embodiment, the liquid crystal mixture according to the invention has a dielectric anisotropy Δε of 3.3 to 3.8.

[0587] In yet another highly preferred embodiment, the liquid crystal mixture according to the invention has a dielectric anisotropy Δε of 2.9 to 3.3.

[0588] The rotational viscosity γ1 at 20° C. is preferably in the range of 70 to 200 mPa·s, and more preferably 90 to 160 mPa·s.

[0589] The medium according to the present invention has an elastic constant K1 in the range of 14-25.

[0590] In a preferred embodiment, the medium according to the invention has a viscosity of 8.2 mPa·s·pN -1 It has the following ratio of rotational viscosity to splay elastic constant γ1 / K1:

[0591] In a preferred embodiment, the medium according to the invention has a viscosity of 6.0 mPa·s·pN -1 ~6.6 mPa·s·pN -1 The ratio of rotational viscosity to splay elastic constant γ1 / K1 is in the range

[0592] In another preferred embodiment, the medium according to the invention has a viscosity of 5.5 mPa·s·pN -1 The ratio of rotational viscosity to splay elastic constant γ1 / K1 is in the range of ~6.0.

[0593] In yet another preferred embodiment, the medium according to the invention has a viscosity of 6.5 mPa·s·pN -1 The ratio of rotational viscosity to splay elastic constant γ1 / K1 is in the range of ~6.8.

[0594] The liquid-crystalline media according to the invention have relatively low values ​​for the threshold voltage (V0): they are preferably in the range from 1.7 V to 3.0 V, particularly preferably ≦2.8 V, very particularly preferably ≦2.6 V.

[0595] In the present invention, the term "threshold voltage" relates to the capacitive threshold (V0), also called the Freederickss threshold, unless explicitly stated otherwise.

[0596] In addition, the liquid-crystalline media according to the invention have high values ​​of the voltage holding ratio in liquid-crystal cells.

[0597] In general, liquid crystal media with a low addressing voltage or threshold voltage show a lower voltage holding ratio than those with a high addressing voltage or threshold voltage, and vice versa.

[0598] In the present invention, the term "dielectrically positive compound" refers to a compound having a Δε of greater than 1.5, the term "dielectrically neutral compound" refers to a compound having a Δε of -1.5 or more and 1.5 or less, and the term "dielectrically negative compound" refers to a compound having a Δε of less than -1.5.

[0599] The dielectric anisotropy of the compounds 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 a layer thickness of 20 μm, both in homeotropic and homogeneous surface alignment. The measurement voltage is typically 0.5 V to 1.0 V, but is always lower than the capacitance threshold of the liquid crystal mixture under consideration.

[0600] All temperature values ​​given in this invention are in °C.

[0601] The mixtures according to the invention are suitable for all VA-TFT applications, such as 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 a negative Δε.

[0602] 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.

[0603] 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 analogy thereto, under known reaction conditions suitable for the reactions. Also, although not mentioned here, per se known variations can be used herein. In particular, they can be prepared as described in the following reaction schemes or in analogy thereto. Further methods for preparing the compounds of the invention can be taken from the examples.

[0604] Other mesogenic compounds not explicitly mentioned above can also be used advantageously in the media according to the invention, such compounds being known to those skilled in the art.

[0605] 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 carried out 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 group having in each case n, m and l C atoms. Preferably, n, m and l are each, independently of one another, 1, 2, 3, 4, 5, 6 or 7. Table A shows the codes for the ring elements of the nucleus of the compounds, Table B lists the bridging units, and Table C lists the meaning of the symbols for the left- and right-most groups of the molecule. The acronyms consist of the code for the ring element with an optional linking group, followed by the code for the first hyphen and the left-most group, and the code for the second hyphen and the right-most group. Table D shows examples of the structures of compounds with their respective abbreviations.

[0606] <Table A: Ring elements>

[0607] [Table 1]

[0608] [Table 2]

[0609] [Table 3]

[0610] [Table 4]

[0611] <Table B: Crosslinking Units>

[0612] [Table 5]

[0613] <Table C: Terminal group>

[0614] [Table 6]

[0615] In the table, n and m are each integers, and the three dots "..." are places for other abbreviations from this table.

[0616] Apart from the compounds of formula I, IIA, IIB, IIC and / or IID, IVa, IVb and V, the mixtures according to the invention preferably comprise one or more compounds of the compounds mentioned below.

[0617] The following abbreviations are used: (n, m, k and l are each independently an integer, preferably 1 to 9, preferably 1 to 7; 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".)

[0618]

[0619] [Table 7]

[0620] [Table 8]

[0621] [Table 9]

[0622] [Table 10]

[0623] [Table 11]

[0624] [Table 12]

[0625] [Table 13]

[0626] [Table 14]

[0627] [Table 15]

[0628] [Table 16]

[0629] [Table 17]

[0630] [Table 18]

[0631] [Table 19]

[0632] [Table 20]

[0633] [Table 21]

[0634] [Table 22]

[0635] Table E shows chiral dopants that are preferably employed in the mixtures according to the invention.

[0636]

[0637] [Table 23]

[0638] [Table 24]

[0639] [Table 25]

[0640] In a preferred embodiment of the invention, the medium according to the invention comprises one or more compounds selected from the group of compounds from Table E.

[0641] Table F shows exemplary compounds which can be preferably used as reactive mesogenic compounds in the LC media according to the invention. If the mixture according to the invention contains one or more reactive compounds, they are preferably employed in an amount of 0.01 to 5% by weight. For the polymerization, it may be necessary to add an initiator or a mixture of two or more initiators. The initiator or initiator mixture is preferably added in an amount of 0.001 to 2% by weight, based on the mixture. Suitable initiators are, for example, Irgacure (BASF) or Irganox (BASF).

[0642] [Table 26]

[0643] [Table 27]

[0644] [Table 28]

[0645] [Table 29]

[0646] Table 30

[0647] Table 31

[0648] Table 32

[0649] Table 33

[0650] Table 34

[0651] Table 35

[0652] Table 36

[0653] Table 37

[0654] Table 38

[0655] Table 39

[0656] [Table 40]

[0657] [Table 41]

[0658] [Table 42]

[0659] [Table 43]

[0660] [Table 44] [Example]

[0661] The present invention will now be described in detail by the following non-limiting examples.

[0662] The following abbreviations and symbols are used: V0 is the capacitance threshold voltage [V] at 20°C. n e is the extraordinary refractive index at 20°C and 589 nm, n0 is the 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°C [mPa·s], K1 is the elastic constant for "splay" deformation at 20°C [pN]. K2 is the elastic constant for "twist" deformation at 20°C [pN], K3 is the elastic constant for "bend" deformation at 20°C [pN].

[0663] Unless expressly stated otherwise, all concentrations in this application are quoted in weight percent and refer to the corresponding mixture as a whole, consisting of all solid or liquid crystal components, excluding solvent.

[0664] Unless explicitly stated otherwise, all temperature values ​​given in this application, such as the melting point T(C,N), the smectic (S) to nematic (N) phase transition T(S,N), and the clearing point T(N,I), are quoted in degrees Celsius (°C). Mp is the melting point, 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.

[0665] All physical properties are or have been determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck, Germany, and apply for a temperature of 20°C, with Δn being determined at 589 nm and Δε at 1 kHz unless expressly indicated otherwise in each case.

[0666] The term "threshold voltage" for the present invention relates to the capacitive threshold (V), also known as the Freederickss threshold, unless otherwise specified. Also, in the examples, and as is generally usual, the threshold voltage is the 10% relative contrast (V 10 ) may also be given as the optical threshold.

[0667] Unless otherwise stated, the step 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, and most preferably at room temperature.

[0668] Unless otherwise specified, the method for preparing test cells and the method for measuring electro-optical properties are carried out by the following method or a method equivalent thereto.

[0669] 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 the inside and an unrubbed polyimide alignment layer on top that provides homeotropic alignment of the liquid crystal molecules.

[0670] 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 the inside, the two polyimide layers rubbed antiparallel to each other to achieve homeotropic edge alignment of the liquid crystal molecules.

[0671] Polymerizable compounds can be polymerized in a display or test cell by irradiating it with UV light of a specified intensity for a predetermined 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 light and 0 to 20 mW / cm. 2 The intensity is measured using a standard meter (Ushio Accumulate UV meter, center wavelength 313 nm).

[0672] The transmittance measurements were performed using a test cell with a fishbone-shaped electrode layout (Merck, Japan; 1 pixel fishbone-shaped electrode (ITO, 10 × 10 mm, fishbone angle 47.7°, 3 μm line / 3 μm space), 3.2 μm cell gap, AF-glass, tilt angle 1°).

[0673] <Mixture example> The nematic LC host mixtures M1 to M105 have the compositions and physical properties given in the table below.

[0674] <Mixture M1> Table 45

[0675] <Mixture M2> Table 46

[0676] <Mixture M3> Table 47

[0677] <Mixture M4> Table 48

[0678] <Mixture M5> Table 49

[0679] <Mixture M6> Table 50

[0680] <Mixture M7> Table 51

[0681] <Mixture M8> Table 52

[0682] <Mixture M9> Table 53

[0683] <Mixture M10> Table 54

[0684] <Mixture M11> Table 55

[0685] <Mixture M12> Table 56

[0686] <Mixture M13> Table 57

[0687] <Mixture M14> Table 58

[0688] <Mixture M15> Mixture M15は, compound B(S)-2O-O1(c5)をcontains む.

change

[0689] <Mixture M16> Mixture M-16は, compound CLY-(c3)2-O2をcontains む.

change

[0690] <Mixture M17> Mixture M17は, compound B(S)-2O-O1(c3)をcontains.

change

[0691] <Mixture M18> Table 62

[0692] <Mixture M19> Table 63

[0693] <Mixture M20> Table 64

[0694] <Mixture M21> Table 65

[0695] <Mixture M22> Table 66

[0696] <Mixture M23> Table 67

[0697] <Mixture M24> Table 68

[0698] <Mixture M25> Table 69

[0699] <Mixture M26> Table 70

[0700] <Mixture M27> Table 71

[0701] <Mixture M28> Table 72

[0702] <Mixture M29> Table 73

[0703] <Mixture M30> Table 74

[0704] <Mixture M31> Table 75

[0705] <Mixture M32> Table 76

[0706] <Mixture M33> Table 77

[0707] <Mixture M34> Table 78

[0708] <Mixture M35> Table 79

[0709] <Mixture M36> Table 80

[0710] <Mixture M37> Table 81

[0711] <Mixture M38> Table 82

[0712] <Mixture M39> Table 83

[0713] <Mixture M40> Table 84

[0714] <Mixture M41> Table 85

[0715] <Mixture M42> Table 86

[0716] <Mixture M43> Table 87

[0717] <Mixture M44> Table 88

[0718] <Mixture M45> Table 89

[0719] <Mixture M46> Table 90

[0720] <Mixture M47> Table 91

[0721] <Mixture M48> Table 92

[0722] <Mixture M49> Table 93

[0723] <Mixture M50> Table 94

[0724] <Mixture M51> Table 95

[0725] <Mixture M52> Table 96

[0726] <Mixture M53> Table 97

[0727] <Mixture M54> [Table 98]

[0728] <Mixture M55> [Table 99]

[0729] <Mixture M56> [Table 100]

[0730] <Mixture M57> Mixture M57 contains 99.965% of mixture M56 and 0.035% of compound ST-3a-1. [ka]

[0731] <Mixture M58> [Table 101]

[0732] <Mixture M59> [Table 102]

[0733] <Mixture M60> [Table 103]

[0734] <Mixture M61> [Table 104]

[0735] Mixture M61 additionally contains 400 ppm of compound ST-3b-1. [ka]

[0736] <Mixture M62> [Table 105]

[0737] <Examples of polymerizable mixtures>

[0738] <Mixture P1> Example mixture P1 consists of 99.595% mixture M-1, 0.40% compound RM-1 and 0.005% compound ST-3a-1. [ka]

[0739] <Mixture P2> Example mixture P2 consists of 99.595% mixture M-2, 0.40% compound RM-1 and 0.005% compound ST-3a-1.

[0740] <Mixture P3> Example mixture P3 consists of 99.595% mixture M-3, 0.40% compound RM-1 and 0.005% compound ST-3a-1.

[0741] <Mixture P4> Example blend P4 consists of 99.595% blend M-4, 0.40% compound RM-1 and 0.005% compound ST-3a-1.

[0742] <Mixture P5> Example blend P5 consists of 99.595% blend M-5, 0.40% compound RM-1 and 0.005% compound ST-3a-1.

[0743] <Mixture P6> Example blend P6 consists of 99.595% blend M-6, 0.40% compound RM-19, and 0.005% compound ST-3a-1. [ka]

[0744] <Mixture P7> The example blend P7 consists of 99.595% blend M-7, 0.40% compound RM-19, and 0.005% compound ST-3b-1.

[0745] <Mixture P8> Example blend P8 consists of 99.595% blend M-8, 0.40% compound RM-35, and 0.005% compound ST-3a-1. [ka]

[0746] <Mixture P9> Example blend P9 consists of 99.595% blend M-9, 0.40% compound RM-156, and 0.005% compound ST-3a-1. [ka]

[0747] <Mixture P10> The example mixture P10 consists of 99.595% mixture M-10, 0.40% compound RM-157, and 0.005% compound ST-3b-1. [ka]

[0748] <Mixture P11> The example mixture P11 consists of 99.685% mixture M62, 0.30% compound RM-1 and 0.015% compound ST-3a-1. [ka] [ka]

[0749] <Mixture M63> [Table 106]

[0750] <Mixture M64> [Table 107]

[0751] <Mixture M65> Mixture M65 consists of 99.09% of mixture M64 and 0.91% of chiral dopant S-4011. [ka]

[0752] <Mixture M66> Mixture M66 consists of 99.7% of mixture M65 and 0.3% of the following reactive mesogens: [ka]

[0753] <Mixture M67> Mixture M67 consists of 99.985% of Mixture M66 and 0.015% of ST-3a-1. [ka]

[0754] <Mixture M68> [Table 108]

[0755] <Mixture M69> Example blend M69 consists of 99.685% blend M67, 0.30% compound RM-1 and 0.015% compound ST-3a-1. [ka] [ka]

[0756] <Mixture M70> [Table 109]

[0757] <Mixture M71> The example mixture M71 consists of 99.66% mixture M70 and 0.04% compound ST-3b-1. [ka]

[0758] <Mixture M72> [Table 110]

[0759] <Mixture M73> [Table 111]

[0760] <Mixture M74> [Table 112]

[0761] <Mixture M75> Table 113

[0762] <Mixture M76> Table 114

[0763] <Mixture M77> Table 115

[0764] <Mixture M78> Table 116

[0765] <Mixture M79> Table 117

[0766] <Mixture M80> Table 118

[0767] <Mixture M81> Table 119

[0768] <Mixture M82> Table 120

[0769] <Mixture M83> Table 121

[0770] <Mixture M84> Table 122

[0771] <Mixture M85> Table 123

[0772] <Mixed M86> Table 124

[0773] <Mixture M87> Table 125

[0774] <Mixture M88> Table 126

[0775] <Mixture M89> Table 127

[0776] <Mixture M90> Table 128

[0777] <Mixture M91> Example mixture M91 is 99.955% mixture M90 ​​and 0.04% of the lower compound. [ka] and 0.005% of the following compounds. [ka]

[0778] <Mixture M92> [Table 129]

[0779] <Mixture M93> The example mixture M93 consists of 99.965% mixture M92 and 0.035% compound ST-3a-1. [ka]

[0780] <Mixture M94> [Table 130]

[0781] <Mixture M95> The example mixture M95 consists of 99.965% mixture M94 and 0.035% compound ST-3a-1. [ka]

[0782] <Mixture M96> [Table 131]

[0783] <Mixture M97> The example mixture M97 consists of 99.97% mixture M97 and 0.03% compound ST-3a-1. [ka]

[0784] <Mixture M98> [Table 132]

[0785] <Mixture M99> The example mixture M99 consists of 99.965% mixture M98 and 0.035% compound ST-3a-1. [ka]

[0786] <Mixture M100> [Table 133]

[0787] <Mixture M101> Mixture M101 consists of 99.09% of mixture M100 and 0.91% of chiral dopant S-4011. [ka]

[0788] <Mixture M102> Mixture M102 consists of 99.7% of mixture M101 and 0.3% of the following reactive mesogens: [ka]

[0789] <Mixture M103> Example mixture M103 consists of 99.985% mixture M102 and 0.015% ST-3a-1. [ka]

[0790] <Mixture M104> The mixture M104 consists of 99.7% of the mixture M100 and 0.3% of the following reactive mesogens: [ka]

[0791] <Mixture M105> The mixture M105 consists of 99.7% of the mixture M100 and 0.3% of the following reactive mesogens: [ka]

Claims

1. Liquid-crystalline medium comprising one or more compounds of the formula I and one, two or more compounds of the formula III. 【Chemical 1】 【Chemistry 2】 (In the ceremony R １１ and R １２ each independently represent H, an alkyl or alkoxy group having 1 to 15 C atoms, provided that one or more CH ２ The group is formed so that the O atoms are not directly connected to each other. 【Chemistry 3】 -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, -O-, -CO-O- or -O-CO-, each independently replaced by one another, provided that one or more H atoms may be replaced by halogen; A １ are, in each occurrence independently of one another, a 1,4-phenylene group (provided that one or two CH groups may be replaced by N) or a 1,4-cyclohexylene or 1,4-cyclohexenylene group (provided that one or two non-adjacent CH groups may be replaced by N). ２ The group may be substituted by —O— or —S—, provided that the group may be mono- or polysubstituted by halogen atoms, n represents 0, 1 or 2; Z １ are each independently of each other in their occurrence -CF ２ O-, -OCF ２ -, -CH ２ O-, -OCH ２ -, -CH ２ -, -CH ２ CH ２ represents -, -CH=CH-, -C≡C- or a single bond, L １１ and L １２ are each independently F, Cl, CF ３ or CHF ２ represents, and W represents O or S.

2. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula III-3 【Chemistry 4】 (In the formula, R １１ and R １２ 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 ２ The groups are formed by -C≡C-, -CF so that the O atoms are not directly linked to each other. ２ O-, -OCF ２ -, -CH=CH-, 【Chemistry 5】 may be independently replaced by —O—, —CO—O—, or —O—CO—, provided that in addition, one or more H atoms may be replaced by a halogen.

3. 2. The liquid-crystalline medium according to claim 1, comprising one or more compounds selected from the compounds of the formulae III-1 and III-2 【Chemistry 6】 (In the formula, R １１ , R １２ , L １１ and L １２ has the meaning given to formula III in claim 1.

4. 4. Liquid-crystalline medium according to claim 3, comprising one or more compounds of the formula III-2

5. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds selected from the group of the formulae IIA, IIB, IIC and IID 【Chemistry 7】 (In the formula, R ２Ａ , R ２Ｂ , R ２Ｃ and R ２Ｄ each independently represent H, an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms, each of which is unsubstituted or at least monosubstituted with a halogen, provided that one or more CH ２ The group is formed by combining -O-, -S-, and -O- groups so that the O atoms are not directly linked to each other. 【Chemistry 8】 -C≡C-, -CF ２ O-, -OCF ２ may be replaced by —, —CO—O— or —O—CO—, L １ and L ２ are each independently F, Cl, CF ３ or CHF ２ represents Y is H, F, Cl, CF ３ , CHF ２ or CH ３ represents Z ２ , Z ２Ｂ and Z ２Ｄ are each independently a single bond, —CH ２ CH ２ -, -CF ２ O-, -OCF ２ -, -CH ２ O-, -OCH ２ represents -, -COO-, or -OCO-; p represents 0, 1 or 2; q represents 0 or 1, and v represents 1, 2, 3, 4, 5 or 6.

6. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula IV-3 【Chemistry 9】 (wherein alkyl represents an alkyl group having 1 to 7 C atoms, and alkenyl represents an alkenyl group having 2 to 7 C atoms, and compounds of formula I in claim 1 are excluded.

7. 7. The liquid-crystalline medium according to claim 6, comprising a compound of the formula IV-3, in which alkenyl is: 【Chemistry 10】 (In the formula, m is 0, 1, or 2, and n is 0, 1, or 2.)

8. 7. Liquid-crystalline medium according to claim 6, comprising a compound of formula IV-3 as defined in claim 6, in which alkenyl denotes vinyl.

9. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula IV-1 in a total concentration in the range from 1% to 30%. 【Chemistry 11】 (In the formula, alkyl and alkyl' may be the same or different and represent alkyl having 1 to 7 carbon atoms.

10. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula V 【Chemistry 12】 (In the formula, R ５１ , R ５２ represents alkyl having 1 to 7 C atoms, alkoxy having 1 to 7 C atoms or alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms, 【Chemistry 13】 represents Z ５１ , Z ５２ are each independently —CH ２ -CH ２ -, -CH ２ represents —O—, —CH═CH—, —C≡C—, —COO— or a single bond, and n is 1 or 2.

11. 2. Liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula H 【Chemistry 14】 (In the formula, Ar represents an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms; Sp represents a spacer group; R Ｓ represents H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; Z Ｓ is -O-, -C(O)O-, -(CH ２ ) ｚ - or - (CH ２ ) ｚ O— or a single bond; HA is, 【Chemistry 15】 represents; R Ｈ H, O ・ , C.H. ３ , OH or OR Ｓ represents; R Ｓ１ , R Ｓ２ , R Ｓ３ and R Ｓ４ are the same or different and represent alkyl having 1 to 6 C atoms; G is H or R Ｓ or group Z Ｓ - represents HA; z is an integer from 1 to 6; and q is 3 or 4.

12. 10. Liquid-crystalline medium according to claim 1, 8 or 9, which comprises one or more compounds selected from the group of compounds of the following formulae: 【Chemistry 16】 【Chemistry 17】 【Chemistry 18】 wherein the parameters are as defined in claims 1, 8 and 9; and alkyl and alkyl ＊ each independently represent a linear alkyl group having 1 to 6 carbon atoms, Alkenyl and alkenyl ＊ each independently represent a straight-chain alkenyl group having 2 to 6 C atoms, (O) alkyl ＊ Or (O)-alkyl is alkyl ＊ or O-alkyl ＊ represents m represents 0, 1, 2, 3, 4, 5 or 6; R is R in formula IIA ２Ａ It has the meaning of R １１ and R １２ are each independently R in formula IIA. ２Ａ has one of the meanings given to L １ and L ２ each independently represents F or Cl, L ３ is H or CH3 を Represents, (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 each represents 0, 1, 2, 3, 4, 5, or 6; Cy represents an alicyclic group having 3, 4 or 5 ring atoms, which may be substituted with alkyl or alkenyl, each having up to 3 C atoms, or halogen or CN.

13. 10. A liquid crystal display comprising a liquid crystal medium according to claim 1.

14. 14. The display of claim 13 which is a VA, IPS, FFS, PS-VA, PS-IPS or PS-FFS display.

15. 2. Use of a liquid-crystalline medium according to claim 1 in a VA, IPS, FFS, PS-VA, PS-IPS or PS-FFS display.

16. 10. Use of a liquid-crystalline medium according to claim 1 for energy-saving LC displays.

17. 2. A process for preparing a liquid crystal medium according to claim 1, comprising the step of mixing one or more compounds of the formulae I and III with optionally further LC compounds and / or additives.

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