Liquid-crystal medium

Abstract

To provide an LC medium to be used for optical, electro-optical, and electronic purposes in an IPS, FFS, VA, or PS-VA display.SOLUTION: A liquid-crystalline medium comprises one or more compounds of a formula IA (wherein R11 and R12, identically or differently, denote H, an alkyl or alkoxy group radical having 1 to 15 carbon atoms, in which one or more CH2 groups are optionally each replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, -O-CO- or the like in such a way that O atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced with halogen).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to liquid crystal (LC) media and, in particular, to the use of LC media for optical, electro-optical and electronic purposes in LC displays, in particular IPS, FFS, VA or PS-VA displays.

Background Art

[0002] One of the currently used liquid crystal display (LCD) modes is the TN ("twisted nematic") mode. However, TN LCDs have the drawback of strong viewing angle dependence of contrast.

[0003] In addition, so-called VA ("vertical alignment") displays with a wider viewing angle are known. The LC cell of a VA display contains a layer of LC 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 arranged perpendicular (homeotropically) to the electrode surface or have an inclined homeotropic arrangement. When a voltage is applied to the two electrodes, rearrangement of the LC molecules parallel to the electrode surface occurs.

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

[0005] Furthermore, so-called FFS ("fringe field switching") displays have been reported (see, inter alia, S.H. Jung et al., Jpn. J. Appl. Phys., Volume 43, No. 3, 2004, 1028), which include two electrodes on the same substrate, one structured in a comb shape and the other unstructured. A strong, so-called "fringe field", i.e., a strong electric field near the edges of the electrodes, is thereby generated, and an electric field with both a strong vertical component and a strong horizontal component is generated across the cell. FFS displays have a low viewing angle dependence of contrast. FFS displays typically include an LC medium with positive dielectric anisotropy and an alignment layer, usually made of polyimide, which gives a planar alignment to the molecules of the LC medium.

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

[0007] Furthermore, FFS displays are disclosed (see S.H. Lee et al., Appl. Phys. Lett. 73(20), 1998, 2882 - 2883 and S.H. Lee et al., Liquid Crystals 39(9), 2012, 1141 - 1148), which have an electrode design and layer thickness similar to those of FFS displays, but include a layer of an LC medium having negative dielectric anisotropy instead of an LC medium having positive dielectric anisotropy. The LC medium having negative dielectric anisotropy exhibits a more preferable director orientation with less tilt and a larger twist direction compared to the LC medium having positive dielectric anisotropy, and as a result, these displays have a higher transmittance. The display further includes an alignment layer, preferably made of polyimide, provided on at least one of the substrates that contacts the LC medium and induces a planar alignment of the LC molecules of the LC medium. These displays are also referred to as "ultrabrightness FFS (UB - FFS)" mode displays. These displays require a highly reliable LC medium.

Prior Art Documents

Non - Patent Documents

[0008]

Non - Patent Document 1

Non - Patent Document 2

Non - Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] As used herein, the term "reliability" means the quality of the performance of a display associated with the passage of time and different stress loads such as light load, temperature, humidity, voltage, etc., and includes display effects such as burn-in (surface and line burn-in), non-uniformity, and contamination, which are known to those skilled in the field of LC displays. As a standard parameter for classifying reliability, the voltage holding ratio (VHR) value is usually used, which is a measure for maintaining a constant voltage in a test display. Among other factors, a high VHR is a prerequisite for the high reliability of the LC medium.

[0010] In more recent types of VA displays, the uniform alignment of LC molecules is restricted to a plurality of relatively small domains within the LC cell. There may be disclinations, also called tilt domains, between these domains. VA displays having tilt domains have a greater contrast and viewing angle independence of gray shades compared to conventional VA displays. Further, this type of display is easier to manufacture because additional processing of the electrode surface, such as by rubbing, for a uniform alignment of molecules in the switched-on state is no longer necessary. Instead, the preferred direction of the tilt angle or pre-tilt angle is controlled by a special design of the electrodes.

[0011] In so-called MVA ("Multi-Domain Vertical Alignment") displays, this is typically achieved by electrodes having protrusions that cause local pretilt. As a result, LC molecules are aligned parallel to the electrode surface in different directions in different defined regions of the cell when a voltage is applied. This enables "controlled" switching and prevents the formation of interference disclination lines. This alignment improves the viewing angle of the display but results in a reduction in light transmissivity. In a further development of MVA, protrusions are used only on one electrode side, and the opposite electrode has slits, which improves light transmissivity. The slit electrodes create a non-uniform electric field within the LC cell when a voltage is applied, which means that controlled switching is still achieved. For further improvement of light transmissivity, the spacing between the slits and the protrusions can be increased, but this results in an increase in the response time. In so-called PVA ("Patterned VA") displays, since both electrodes are composed of opposing slits, the protrusions become completely redundant, which results in an increase in contrast and an improvement in light transmissivity, but is technically difficult and makes the display more sensitive to mechanical effects ("tapping", etc.). However, in many applications such as monitors, especially TV screens, etc., a reduction in response time and an improvement in the contrast and brightness (transmittance) of the display are required.

[0012] A further development is so-called PS ("Polymer Stabilized") or PSA ("Polymer Stabilized Alignment") type displays, and the term "polymer stabilization" is also sometimes used. In these, a small amount (e.g., 0.3 wt%, usually <1 wt%) of one or more polymerizable compounds, preferably polymerizable monomer compounds, are added to the LC medium, and after filling the LC medium into the display, it is polymerized or crosslinked in situ, usually by UV photopolymerization, optionally while applying a voltage to the electrodes of the display. The polymerization is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, 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 to be particularly suitable.

[0013] Unless otherwise specified, the term "PSA" is used hereinafter to refer to displays of the polymer-maintained alignment type in general, and the term "PS" is used when referring to specific display modes such as PS-VA and PS-TN.

[0014] Also, unless otherwise instructed, the term "RM" is used when referring to a polymerizable mesogen or a liquid crystal compound.

[0015] On the other hand, the PS(A) principle is used in various conventional LC display modes. Thus, for example, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, and PS-TN displays are known. The polymerization of RM is preferably carried out without an applied voltage in the case of PS-VA and PS-OCB displays together with the applied voltage, and preferably without an applied voltage in the case of PS-IPS displays with or without an applied voltage. As can be demonstrated in a test cell, the PS(A) method provides a pretilt to the cell. In the case of a PS-VA display, the pretilt has a positive effect on the response time. In the case of a PS-VA display, a standard MVA or PVA pixel and electrode layout can be used. However, furthermore, for example, it is also possible to dispense with protrusions on only one of the structured electrode sides, which greatly simplifies production while at the same time providing very good contrast and very good light transmittance.

[0016] PS-VA displays are described, for example, in EP1170626A2, US6,861,107, US7,169,449, US2004 / 0191428A1, US2006 / 0066793A1 and US2006 / 0103804A1. PS-OCB displays are described, for example, in T.-J- Chen et al., Jpn.J.Appl.Phys.45, 2006, 2702-2704 and S.H.Kim, L.-C- Chien, Jpn.J.Appl.Phys.43, 2004, 7643-7647. PS-IPS displays are described, for example, in US6,177,972 and Appl.Phys.Lett.1999, 75(21), 3264. PS-TN displays are described, for example, in Optics Express 2004, 12(7), 1221.

[0017] A liquid crystal medium suitable for application to the above types of displays according to the present invention is also disclosed in EP17161352.

[0018] Another problem observed in the prior art is that LC media used in PSA displays, including but not limited to PSA type displays, often exhibit high viscosities, and as a result, long switching times. To reduce the viscosity and switching time of the LC medium, it has been proposed in the prior art to add LC compounds having alkenyl groups. However, LC media containing alkenyl compounds often exhibit a decrease in reliability and stability, and in particular, a decrease in VHR has been observed especially after UV irradiation. In particular, when used in PSA displays, the photopolymerization of RM in PSA displays is usually carried out by exposure to UV radiation, which can cause a decrease in VHR in the LC medium, which is a significant disadvantage.

[0019] Furthermore, simultaneously with a high resistivity, it enables a wide operating temperature range, a short response time even at low temperatures, a low threshold voltage, a low pretilt angle, a multiplicity of gray shades, a high contrast and a wide viewing angle, and has high reliability and high values of VHR after UV exposure. Also, in the case of a polymerizable compound, it has a low melting point and high solubility in an LC host mixture. There is a great demand for PSA displays and LC media and polymerizable compounds used in such PSA displays. In PSA displays for mobile applications, it is particularly desirable to have an available LC medium that exhibits a low threshold voltage and high birefringence.

[0020] Therefore, there remains a great demand for an LC medium for use in such displays that exhibits few or no such drawbacks and has improved properties. The series of compounds disclosed so far having a liquid crystal mesophase do not include any compound that satisfies all of these requirements. Therefore, in order to obtain a substance that can be used as an LC phase, a mixture of generally 2 to 25, preferably 3 to 18 compounds is prepared. However, since a liquid crystal material having a significantly negative dielectric anisotropy and appropriate long-term stability has not been available until now, it has not been possible to easily prepare an optimal phase by this method.

Means for Solving the Problems

[0021] The present invention is based on the object of providing a novel and suitable material in an LC medium, optionally containing a reactive mesogen (RM), for use in a PSA display.

[0022] Furthermore, it is an object of the present invention to provide alternative media in addition to existing media known to those skilled in the art in order to widen the range of available materials that enable more specific optimization of a particular display.

[0023] These objects have been achieved by the present invention by the materials and methods described in the present application. In particular, surprisingly, it has been found that the use of the liquid crystal host described below makes it possible to achieve the above-mentioned advantageous effects.

Mode for Carrying Out the Invention

[0024] The present invention relates to an LC medium comprising one or more compounds of formula IA.

[0025]

Chemical formula

[0026] This type of medium can be used, in particular, in electro-optical displays with active matrix addressing based on the ECB effect, and in IPS (In-Plane Switching) displays or FFS (Fringe Field Switching) displays. The medium is characterized by a surprisingly low rotational viscosity in combination with a high voltage holding ratio and a high clearing temperature. This, together with the broad nematic phase range and excellent low-temperature stability of the medium at -20°C and -30°C, enables displays with a broad operating temperature range, fast switching times, and excellent stability under storage at low temperatures.

[0027] The mixture according to the invention is further characterized by the fact that, in addition to the improvement of the rotational viscosity γ1, a relatively high value of the elastic constant K 33 can be observed, which improves the response time. The use of the compound of formula IA in an LC mixture, preferably having negative dielectric anisotropy, rotational viscosity ratio γ1 and elastic constant K1, is reduced.

[0028] Preferred embodiments of the present invention are defined in the dependent claims and are shown below.

[0029] The liquid crystal medium according to the invention, also referred to herein as a liquid crystal host mixture, is suitable for use in polymer stabilized displays. For this purpose, the medium according to the invention optionally contains one or more polymerizable compounds of formula P. P-Sp-A 1 -(Z 1 -A 2 ) z -R P (wherein the individual radicals, independently of one another and for each occurrence, are the same or different and have the following meanings: P represents a polymerizable group, Sp represents a spacer group or a single bond, A 1 , A 2 preferably represents an aromatic, heteroaromatic, alicyclic or heterocyclic group having 4 to 25 ring atoms, which may contain fused rings and which is unsubstituted or mono- or polysubstituted by L, Z 1 is -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 represents a single bond, R 0 , R 00 represents H or alkyl having 1 to 12 carbon atoms, R represents H, L, or P-Sp-, L represents a straight-chain, branched or cyclic alkyl having F, Cl, -CN, P-Sp-, or 1 to 25 carbon atoms, wherein one or more non-adjacent CH2 groups are optionally substituted by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- such that O and / or S atoms are not directly linked to each other, and optionally one or more H atoms are each substituted by P-Sp-, F or Cl, z represents 0, 1, 2 or 3, n1 represents 1, 2, 3, or 4.)

[0030] As used herein, the terms "active layer" and "switchable layer" mean a layer in an electro-optical display, such as an LC display, that contains one or more molecules having structural and optical anisotropy, such as LC molecules, which, upon an external stimulus such as an electric or magnetic field, changes its orientation, resulting in a change in the transmittance of the layer for polarized or non-polarized light.

[0031] As used herein, the terms "tilt" and "tilt angle" are to be understood to mean the tilted arrangement of the LC molecules of the LC medium with respect to the surface of the cell of an LC display (preferably a PSA display here). Here, the tilt angle represents the average angle (<90°) between the longitudinal molecular axis (LC director) of the LC molecules and the surface of the parallel plane outer plate forming the LC cell. A low value of the tilt angle (i.e., a large deviation from the 90° angle) corresponds here to a large tilt. A method suitable for measuring the tilt angle is shown in the examples. Unless otherwise specified, the tilt angle values disclosed above and below relate to this measurement method.

[0032] As used herein, the terms "reactive mesogen" and "RM" are to be understood to mean a compound containing a mesogen or liquid crystal backbone and one or more functional groups attached thereto that are suitable for polymerization and are also referred to as "polymerizable groups" or "P".

[0033] Unless otherwise specified, the term "polymerizable compound" as used herein is understood to mean a polymerizable monomer compound.

[0034] The term "low molecular weight compound" as used herein is understood to mean a compound that is a monomer and / or is not prepared by a polymerization reaction, in contrast to a "high molecular weight compound" or a "polymer".

[0035] The term "non-polymerizable compound" as used herein is understood to mean a compound that does not contain functional groups suitable for polymerization under conditions normally applicable to the polymerization of RM.

[0036] The term "mesogenic group" as used herein is known to those skilled in the art and is described in the literature, and means a group that essentially contributes to causing a liquid crystal (LC) phase in a low molecular weight or high molecular weight substance due to the anisotropy of its attractive and repulsive interactions. A compound containing a mesogenic group (mesogenic compound) does not necessarily have an LC phase by itself. It is also possible for a mesogenic compound to exhibit LC phase behavior only after mixing with other compounds and / or after polymerization. Typical mesogenic groups are, for example, rigid rod-like or disc-like units. An overview of the terms and definitions used in relation to mesogens or LC compounds is described in Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.

[0037] The terms "optically active" and "chiral" as used herein are synonyms for materials that can induce a helical pitch in a nematic host material, also called a "chiral dopant".

[0038] As used herein, the term "spacer group" (hereinafter also referred to as "Sp") is known to those skilled in the art and is described in the literature. See, for example, Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. As used herein, the term "spacer group" or "spacer" means a flexible group that connects a mesogenic group and a polymerizable group in a polymerizable mesogenic compound, for example, an alkylene group.

[0039] TIFF2025098072000003.tif38166

[0040] TIFF2025098072000004.tif24166

[0041] In the above and below, "organic group" refers to a carbon or hydrocarbon group.

[0042] "Carbon group" refers to a monovalent or polyvalent organic group containing at least one carbon atom, which may or may not contain additional atoms (e.g., -C≡C-), or optionally contains one or more additional atoms such as N, O, S, B, P, Si, Se, As, Te, or Ge (e.g., carbonyl, etc.). The term "hydrocarbon group" refers to a carbon group that further contains one or more H atoms and optionally one or more heteroatoms such as N, O, S, B, P, Si, Se, As, Te, or Ge.

[0043] "Halogen" refers to F, Cl, Br, or I, preferably F or Cl.

[0044] -CO-, -C(=O)-, and -C(O)- represent a carbonyl group, that is, TIFF2025098072000005.tif17166 is shown.

[0045] The carbon or hydrocarbon group may be a saturated or unsaturated group. The unsaturated group is, for example, an aryl, alkenyl or alkynyl group. A carbon or hydrocarbon group having more than 3 C atoms may be linear, branched and / or cyclic, and may also include spiro bonds or fused rings.

[0046] Terms such as "alkyl", "aryl", "heteroaryl", etc. also include polyvalent groups, such as alkylene, arylene, heteroarylene, etc.

[0047] The term "aryl" refers to an aromatic carbon group or a group derived therefrom. The term "heteroaryl" preferably refers to the "aryl" defined above and containing one or more heteroatoms selected from N, O, S, Se, Te, Si and Ge.

[0048] 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, very preferably 1 to 12 C atoms, optionally substituted aryl or aryloxy having 5 to 30, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25 C atoms, wherein one or more C atoms may preferably be substituted by a heteroatom selected from N, O, S, Se, Te, Si and Ge.

[0049] Even 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-C20 Polyenyl, C6-C 20 Cycloalkyl, C4-C 15 Cycloalkenyl, C6-C 30 Aryl, C6-C 30 Alkylaryl, C6-C 30 Arylalkyl, C6-C 30 Alkylaryloxy, C6-C 30 Arylalkyloxy, C2-C 30 Heteroaryl, C2-C 30 Is heteroaryloxy.

[0050] C1-C 12 Alkyl, C2-C 12 Alkenyl, C2-C 12 Alkynyl, C6-C 25 Aryl and C2-C 25 Heteroaryl is particularly preferred.

[0051] More preferred carbon and hydrocarbon groups are linear, branched or cyclic alkyls having 1 to 20, preferably 1 to 12 C atoms, which are unsubstituted or mono- or polysubstituted with F, Cl, Br, I, CN, and one or more non-adjacent CH2 groups are each independently such that O and / or S atoms are not directly bonded to each other, -C(R x )=C(R x )-, -C≡-, -N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be substituted.

[0052] R xrepresents, preferably, a linear, branched or cyclic alkyl chain having H, F, Cl, CN, or 1 to 25 C atoms, and further, one or more non-adjacent C atoms may be substituted by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms may be substituted by F or Cl, or alternatively, an aryl or aryloxy group having 6 to 30 C atoms which is optionally substituted, or a heteroaryl or heteroaryloxy group having 2 to 30 C atoms which is optionally substituted.

[0053] 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, etc.

[0054] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.

[0055] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

[0056] 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, etc.

[0057] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

[0058] 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 can also be fused (e.g., naphthyl, etc.) or covalently bonded (e.g., biphenyl, etc.), or can contain a combination of fused rings and linked rings. The heteroaryl group preferably contains one or more heteroatoms selected from O, N, S and Se.

[0059] Particularly preferred are monocyclic, bicyclic or tricyclic aryl groups having 6 to 25 C atoms, optionally containing fused rings and optionally substituted, and monocyclic, bicyclic or tricyclic heteroaryl groups having 5 to 25 ring atoms. Further, 5-membered, 6-membered or 7-membered aryl and heteroaryl groups are preferred, where one or more CH groups may be further substituted with N, S or O such that O atoms and / or S atoms do not directly bond to each other.

[0060] 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.

[0061] Preferred heteroaryl groups include, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole; 6-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine; or fused rings such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, purine, naphthoimidazole, phenanthrolizine, pyridinoimidazole, pyrazinoimidazole, quinoxalinoimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarbazole, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiophene, benzothiadiazothiophene; or combinations of these groups.

[0062] The aryl and heteroaryl groups above and below may be substituted with alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl, or a further aryl or heteroaryl group.

[0063] (Non-aromatic) Alicyclic and heterocyclic groups include both saturated rings, i.e., those containing only single bonds, and partially unsaturated rings, i.e., those containing multiple bonds. Heterocycles preferably contain one or more heteroatoms selected from Si, O, N, S, and Se.

[0064] (Non-aromatic) Alicyclic and heterocyclic groups can be monocyclic, i.e., containing only one ring (e.g., cyclohexane, etc.), or polycyclic, i.e., containing multiple rings (e.g., decahydronaphthalene or bicyclooctane, etc.). Saturated groups are particularly preferred. Monocyclic, bicyclic, or tricyclic groups having 5 to 25 ring atoms, optionally containing fused rings and optionally substituted, are more preferred. Further, one or more C atoms may be substituted by Si, and / or one or more CH groups may be substituted by N, and / or one or more non-adjacent CH2 groups may be substituted by -O- and / or -S-. Five-membered, six-membered, seven-membered, or eight-membered carbocyclic groups are more preferred.

[0065] Preferred alicyclic and heterocyclic groups are, for example, five-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiophene, pyrrolidine, etc., six-membered groups such as cyclohexane, silinane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine, etc., seven-membered groups such as cycloheptane, etc., and fused groups such as tetrahydronaphthalene, decahydronaphthalene, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindane-2,5-diyl, etc.

[0066] Preferred substituents are, for example, 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) of the polymer, particularly bulky groups such as t-butyl or optionally substituted aryl groups.

[0067] The following preferred substituents, also referred to as "L" S ", are, for example, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 , -C(=O)R x , -N(R x )2, linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having from 1 to 25 C atoms, where one or more H atoms may optionally be replaced by F or Cl, an optionally substituted silyl having from 1 to 20 Si atoms, or an optionally substituted aryl having from 6 to 25, preferably from 6 to 15, C atoms, where R x represents H, F, Cl, CN, or linear, branched or cyclic alkyl having from 1 to 25 C atoms, where one or more non-adjacent CH2 groups are optionally substituted by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- such that O and / or S atoms are not directly linked to each other, and where one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-, and Y 1 represents halogen.

[0068] "Substituted silyl or aryl" preferably means substituted by halogen-CN, R 0 , -OR 0 , -CO-R 0 , -CO-OR 0 , -O-CO-R 0 or -O-CO-OR 0 , where R 0 represents H or alkyl having from 1 to 20 C atoms.

[0069] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and further phenyl.

[0070] A 1 and A 2 are very preferably TIFF2025098072000006.tif18166, where in the formula, L has one of the above meanings, r represents 0, 1, 2, 3, or 4, and particularly TIFF2025098072000007.tif21166

[0071] The polymerizable group P is, for example, a group suitable for polymerization reactions such as free radical or ionic chain polymerization, polyaddition, or polycondensation, or a group suitable for polymer-analogous reactions, such as addition or condensation to the polymer main chain. Groups for chain polymerization, particularly groups containing a C=C double bond or a -C≡C- triple bond, and groups suitable for polymerization involving ring opening, such as oxetane or epoxide groups, are particularly preferred.

[0072] Preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, TIFF2025098072000008.tif48166CH2=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 2W 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 Selected from the group consisting of Si-, where W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, especially H, F, Cl or CH3, and W 2 and W 3 each independently represents H or alkyl having 1 to 5 C atoms, especially H, methyl, ethyl or n-propyl, and W 4 W 5 and W 6 each independently represents Cl, oxaalkyl or oxocarbonylalkyl having 1 to 5 C atoms, and W 7 and W 8 each independently represents H, Cl, or alkyl having 1 to 5 C atoms, Phe represents 1,4-phenylene, which is optionally substituted by one or more groups L 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.

[0073] A very preferred group P is CH2=CW 1 -CO-O-, CH2=CW 1 -CO- TIFF2025098072000009.tif48166CH2=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 Selected from the group consisting of Si-, where W 1 represents H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, especially H, F, Cl or CH3, and W 2 and W 3 each independently represents H or alkyl having 1 to 5 C atoms, especially H, methyl, ethyl or n-propyl, and W 4 W 5 and W 6 each independently represents Cl, oxaalkyl or oxocarbonylalkyl having 1 to 5 C atoms, and W 7 and W 8 each independently represents 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 from 1 to 10.

[0074] A very particularly preferred group P is CH2=CW 1 -CO-O-, especially 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- Selected from the group consisting of TIFF2025098072000010.tif22166.

[0075] More preferably, the polymerizable group P is selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, and most preferably selected from acrylate and methacrylate.

[0076] When the spacer group Sp is different from a single bond, it is preferably of the formula Sp”-X”, whereby each group P-Sp- follows the formula R-Sp”-X”- where, Sp” represents a linear or branched alkylene having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN, and furthermore, one or more non-adjacent CH2 groups are each independently of one another such that O and / or S atoms are not directly bonded to each other, -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- may be substituted, 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 -,-C≡C-,-CH=CH-CO-O-,-O-CO-CH=CH- or a single bond, R 0 and R 00each independently represents H or an alkyl having 1 to 20 C atoms, and Y 2 and Y 3 each independently represents H, F, Cl, or CN, X” is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 00 - or a single bond.

[0077] Typical spacer groups Sp and -Sp”-X”- are, for example, -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, -(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR 0 R 00 -O) p1 -, where p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 have the above meanings.

[0078] Particularly preferred groups Sp and -Sp”-X”- are -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, where p1 and q1 have the above meanings.

[0079] Particularly preferred groups Sp” are, in each case, linear ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methylenoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

[0080] In a preferred embodiment of the present invention, the compounds of formula P and its sub-formulas contain a spacer group Sp substituted by one or more polymerizable groups P, whereby the group Sp-P corresponds to Sp(P) s and s is 2 or more (branched polymerizable group).

[0081] Preferred compounds of formula P according to this preferred embodiment are those in which s is 2, i.e., compounds containing the group Sp(P)2. Very preferred compounds of formula P according to this preferred embodiment contain groups selected from the following formulas. -X-alkyl-CHPP S1 -X-alkyl-CH((CH2) aa P)((CH2) bb P) S2 -XN((CH2) aa P)((CH2) bb P) S3 -X-alkyl-CHP-CH2-CH2P S4 -X-alkyl-C(CH2P)(CH2P)-C aa H 2aa+1 S5 -X-alkyl-CHP-CH2P S6 -X-alkyl-CPP-C aa H 2aa+1 S7 -X-alkyl-CHPCHP-C aa H 2aa+1 S8 (wherein P is as defined in formula P, Alkyl represents a single bond or a straight-chain or branched alkylene having 1 to 12 carbon atoms that is unsubstituted or mono- or polysubstituted with F, Cl, or CN, where one or more non-adjacent CH2 groups are each independently, such that O and / or S atoms are not directly bonded to each other, -C(R 0 )=C(R 0 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be substituted, where R 0 has the above meanings, aa and bb each independently represent 0, 1, 2, 3, 4, 5, or 6, X has one of the meanings shown for X”, preferably O, CO, SO2, O-CO-, CO-O, or a single bond.)

[0082] Preferred spacer group Sp(P)2 is selected from formulas S1, S2, and S3.

[0083] A very preferred spacer group Sp(P)2 is selected from the following sub-formulas: -CHPP S1a -O-CHPP S1b -CH2-CHPP S1c -OCH2-CHPP S1d -CH(CH2-P)(CH2-P) S2a -OCH(CH2-P)(CH2-P) S2b -CH2-CH(CH2-P)(CH2-P) S2c -OCH2-CH(CH2-P)(CH2-P) S2d -CO-NH((CH2)2P)((CH2)2P) S3a

[0084] In the compounds of the above and below formulas P and its sub-formulas, P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, and most preferably selected from acrylate and methacrylate.

[0085] More preferably, the compounds are those of the above and below formulas P and its sub-formulas, wherein all the polymerizable groups P present in the compound have the same meaning, very preferably acrylate or methacrylate, and most preferably methacrylate.

[0086] In the compounds of the above and below formulas P and its sub-formulas, R preferably represents P-Sp-.

[0087] More preferably, the compounds are those of the above and below formulas P and its sub-formulas, where Sp is a single bond or -(CH2) p1 -, -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 and p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 then the O atom or the CO group is respectively linked to the benzene ring.

[0088] More preferably, the compounds are those of the above and below formulas P and its sub-formulas in which at least one Sp group is a single bond.

[0089] More preferably, the compounds are those of the above and below formulas P and its sub-formulas, where at least one Sp group is different from a single bond and is preferably -(CH2) p1 -, -O-(CH2) p1 -, -O-CO-(CH2) p1 , or -CO-O-(CH2) p1selected from, where p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH2) p1 -, -O-CO-(CH2) p1 or -CO-O-(CH2) p1 then the O atom or CO group is each linked to the benzene ring.

[0090] Very preferred group -A in formula P 1 -(ZA 2 ) z - is selected from the following formulae.

[0091] [Chemical formula] (wherein at least one benzene ring is substituted with at least one group L, and the benzene ring is optionally further substituted with one or more groups L or P-Sp-.)

[0092] Preferred compounds of formula P and their sub-formulae are selected from the following preferred embodiments, including any combination thereof: - all P groups in the compound have the same meaning, - -A 1 -(ZA 2 ) z - is selected from formulae A1, A2, and A5, - the compound contains two polymerizable groups (represented by group P), - the compound contains exactly three polymerizable groups (represented by group P), - P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate, - P is methacrylate, - all Sp groups are single bonds, - at least one of the Sp groups is a single bond and at least one of the Sp groups is different from a single bond, - when 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 is respectively linked to the benzene ring - Sp is a single bond or -(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 is respectively linked 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, where one or more non-adjacent CH2 groups are optionally substituted by -O-,-S-,-CO-,-CO-O-,-O-CO-,-O-CO-O- so that O and / or S atoms are not directly linked to each other, and one or more H atoms are each optionally substituted by F, Cl or L a and are substituted by - L or L' represents F, Cl or CN - L is F

[0093] In formula IA, R 11 and R 12 preferably represent alkyl or alkenyl or alkoxy having 1 to 7 C atoms, and R 12 particularly preferably represents alkoxy having 1 to 7 C atoms

[0094] The compound of formula IA is preferably selected from the group of compounds of formulas IA-1 to IA-10

[0095]

Chemical formula

[0096] 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.

[0097]

Chemical formula

[0098] In a preferred embodiment of the invention, the medium comprises one or more compounds of formula IB.

[0099] [Chemical formula] (In the formula, R 11 and R 12 each independently represents H, an alkyl or alkoxy radical having 1 to 15 C atoms, and further, one or more CH2 groups in these groups are each independently -C≡C-, -CF2O-, -OCF2-, -CH=CH-, TIFF2025098072000017.tif12166 - O-, -CO - O- or -O - CO-, so that O atoms are not directly bonded to each other and may be substituted, and further, one or more H atoms may be substituted by halogen, A 1 each independently for each occurrence, a) 1,4 - cyclohexenylene or 1,4 - cyclohexylene group, where one or two non - adjacent CH2 groups may be substituted by -O- or -S-, b) 1,4 - phenylene group, where one or two CH groups may be substituted by N, c) a group from piperidine - 1,4 - diyl, 1,4 - bicyclo[2.2.2]octylene, naphthalene - 2,6 - diyl, decahydronaphthalene - 2,6 - diyl, 1,2,3,4 - tetrahydronaphthalene - 2,6 - diyl, phenanthrene - 2,7 - diyl and fluorene - 2,7 - diyl groups represents, where the groups a), b) and c) may be mono - or polysubstituted by halogen atoms, a represents 0, 1 or 2, preferably 0 or 1, particularly preferably 0, Z 1 each independently for each occurrence represents -CO - O-, -O - CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH = CH - CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF = CF-, -CH = CF-, -CF = CH-, -CH = CH-, -C≡C- or a single bond, X 1 represents S or O, and L 11 and L 12 each independently represents F, Cl, CF3 or CHF2, preferably H or F, most preferably F, provided that compounds of formula IA are excluded.)

[0100] In the compounds of formulae IA, IB and IC, R 11 and R 12 are preferably each independently a straight-chain alkyl, especially CH3, n-C2H5, n-C3H7, n-C4H9, n-C5H 11 , n-C6H 13 -, or n-C7H 15 , a straight-chain alkoxy, especially CH3-O, n-C2H5-O, n-C3H7-O, n-C4H9-O, n-C5H 11 -O or n-C6H 13 -O, further alkenyl, especially CH2=CH, CH3CH=CH, CH3CH=CHCH2 or CH3CH2CH=CH, branched alkoxy, especially (CH3)2CH(CH2)3O, and alkenyloxy, especially CH2=CHO, CH2=CH2CH2O, CH3CH=CHCH2O or CH3CH2CH=CHCH2O.

[0101] R 11 particularly preferably represents a straight-chain alkyl having 1 to 7 C atoms, and R 12 particularly preferably represents a straight-chain alkoxy having 1 to 6 C atoms, especially methoxy, ethoxy, propoxy, butoxy, pentoxy or hexyloxy.

[0102] In formula IB, L 11 and L 12 both preferably represent F.

[0103] The parameter "a" of formula IB preferably represents 1.

[0104] Preferred compounds of formula IB present in the medium are compounds of formulae IB-1 to IB-3, preferably compounds of formula IB-2.

[0105] [Chemical formula] (In the formula, The groups that appear have the above meanings, and preferably, R 11 represents a linear alkyl, R 12 represents an alkoxy, and L 11 and L 12 both represent F.)

[0106] In a preferred embodiment, the medium comprises one or more compounds of formula IB selected from the group of compounds of formulae IB-O-1 to IB-O-3, preferably compounds of formula IB-O-2.

[0107] [Chemical formula] (In the formula, the groups that appear have the above meanings.)

[0108] In another preferred embodiment, the medium comprises one or more compounds of formula IB selected from the group of compounds of formulae IB-S-1 to IB-S-3, preferably compounds of formula IB-S-2.

[0109] [Chemical formula] (In the formula, the parameters have the meanings given above.)

[0110] In a preferred embodiment of the present invention, the medium comprises one or more compounds selected from the group of compounds of formulae IB-O-1 to IB-O-3, and one or more compounds selected from the group of compounds of formulae IB-S-1 to IB-S-3.

[0111] In a preferred embodiment, the medium comprises one or more compounds of formula IC.

[0112]

Chemical formula

[0113] In a preferred embodiment, the medium comprises one or more compounds of formula IC selected from the group of compounds of formula IC-O-1 to IC-O-10, preferably the compound of formula IC-O-6.

[0114]

Chemical formula

[0115] In a further preferred embodiment, the medium contains, instead of or in addition to one or more compounds selected from the group of compounds of formulas IC-O-1 to IC-O-10, X 1 one or more compounds of formula IC where X 1 is S, preferably a compound selected from the group of compounds of formulas IC-S-1 to IC-S-10, preferably a compound selected from IC-S-6, which has the same structure as the corresponding compounds of formulas IC-O-1 to IC-O-10 with the same number, except that the bridging atom (i.e., X

[0116] The compounds of formulas IA, IB and IC can be prepared as described, for example, in US2005 / 0258399 or WO02 / 055463A1. The compounds of formula IA are disclosed in DE102015004271A1.

[0117] Preferred embodiments of the liquid crystal medium according to the invention are shown below:

[0118] a) A liquid crystal medium further containing one or more compounds selected from the group of compounds of formulas IIA, IIB, IIC and IID.

[0119] In the compounds of formulas IIA, IIB and IID, Z 2 can have the same or different meanings. In the compounds of formula IIB, Z 2 and Z 2B can have the same or different meanings. In the compounds of formula IID, Z 2 and Z 2D can have the same or different meanings.

[0120] In the compounds of formulas IIA, IIB, IIC and IID, R 2A , R 2B , R 2C and R 2D each preferably represent an alkyl having 1 to 6 C atoms, in particular CH3, C2H5, n-C3H7, n-C4H9, n-C5H 11 .

[0121] In the compounds of formulae IIA, IIB and IID, L 1 , L 2 , L 3 and L 4 preferably represent L 1 =L 2 =F and L 3 =L 4 =F, further L 1 =F and L 2 =Cl, L 1 =Cl and L 2 =F, L 3 =F and L 4 =Cl, L 3 =Cl and L 4 =F. In formulae IIA and IIB, Z 2 and Z 2’ each preferably represent, independently of one another, a single bond and further represent a -C2H4- bridge.

[0122] If, in formula IIB, Z 2 =-C2H4- or -CH2O-, then Z 2B is preferably a single bond, or if Z 2B =-C2H4- or -CH2O-, then Z 2 is preferably a single bond.

[0123] In formula IID, Z 2D is preferably a single bond.

[0124] In the compounds of formulae IIA, IIB and IID, (O)C v H 2v+1 preferably represents OC v H 2v+1 . In the compounds of formula IIC, (O)C v H 2v+1 preferably represents C v H 2v+1 .

[0125] In the compounds of formula IIC, L 3 and L 4 preferably each represent F.

[0126] Preferred compounds of formulas IIA, IIB and IIC are shown below:

[0127]

Chemical formula

[0128] Particularly preferred mixtures according to the invention comprise one or more compounds of formulas IIA-2, IIA-8, IIA-14, IIA-26, II-28, IIA-33, IIA-39, IIA-45, IIA-46, IIA-47, IIA-50, IIB-2, IIB-11, IIB-16, IIC-1, and IID-4.

[0129] The proportion of compounds of formula IIA and / or IIB in the total mixture is preferably at least 20% by weight.

[0130] Particularly preferred media according to the invention contain at least one compound of formula IIC-1,

[0131]

Chemical formula

[0132] b) A liquid crystal medium further containing one or more compounds of formula III.

[0133]

Chemical formula

[0134] Preferred compounds of formula III are shown below:

[0135]

Chemical formula

[0136] The media according to the invention preferably contain at least one compound of formula IIIa and / or formula IIIb.

[0137] The proportion of the compound of formula III in the entire mixture is preferably at least 5% by weight.

[0138] c) A liquid crystal medium further comprising a compound of the following formula, preferably in an amount of 5% by weight or more, particularly 10% by weight or more, in the total amount.

[0139]

Chemical formula

[0140] A mixture according to the invention further comprising the compound (acronym: CC-3-V1) in an amount preferably in the range of 2 to 15% by weight is more preferred.

[0141]

Chemical formula

[0142] Preferred mixtures contain 5 to 60% by weight, preferably 10 to 55% by weight, particularly 20 to 50% by weight of the compound of formula (acronym: CC-3-V).

[0143]

Chemical formula

[0144] Furthermore, the compound of formula (acronym: CC-3-V)

[0145]

Chemical formula

[0146]

Chemical formula

[0147] d) A liquid crystal medium further comprising one or more tetracyclic compounds of the following formula.

[0148]

Chemical formula

[0149] A mixture containing at least one compound of formula V-9 is particularly preferred.

[0150] e) A liquid crystal medium further comprising one or more compounds of formulae Y-1 to Y-6.

[0151]

Chemical formula

[0152] The medium according to the invention particularly preferably contains one or more compounds of formulae Y-1 to Y-6, preferably in an amount of 5% by weight or more.

[0153] f) A liquid crystal medium further comprising one or more fluorinated terphenyls of formulae T-1 to T-21.

[0154]

Chemical formula

[0155] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0156] The medium according to the invention preferably contains terphenyls of formulas T-1 to T-21 in an amount of 2 to 30% by weight, in particular 5 to 20% by weight.

[0157] Compounds of formulas T-1, T-2, T-4, T-20 and T-21 are particularly preferred. In these compounds, R preferably represents alkyl and further alkoxy each having 1 to 5 carbon atoms. In the compound of formula T-20, R preferably represents alkyl or alkenyl, in particular alkyl. In the compound of formula T-21, R preferably represents alkyl.

[0158] Terphenyl is preferably used in the mixture according to the invention if the Δn value of the mixture is 0.1 or more. Preferred mixtures contain 2 to 20% by weight of one or more terphenyl compounds selected from the group of compounds T-1 to T-21.

[0159] g) A liquid crystal medium further containing one or more biphenyls of formulas B-1 to B-3.

[0160]

Chemical formula

[0161] The proportion of biphenyls of formulae B-1 to B-3 in the whole mixture is preferably at least 3% by weight, in particular 5% by weight or more.

[0162] Among the compounds of formulae B-1 to B-3, the compound of formula B-2 is particularly preferred.

[0163] Particularly preferred biphenyls are

[0164]

Chemical formula

[0165] The medium according to the invention particularly preferably contains one or more compounds of formula B-1a and / or B-2c.

[0166] h) A liquid crystal medium containing at least one compound of formulae Z-1 to Z-7.

[0167]

Chemical formula

[0168] i) A liquid crystal medium further containing at least one compound of formulae O-1 to O-18.

[0169]

Chemical formula

[0170] R 1 and R 2Preferably, each independently represents a linear alkyl or alkenyl.

[0171] Preferred media contain one or more compounds of formulae O-1, O-3, O-4, O-6, O-7, O-10, O-11, O-12, O-14, O-15, O-16 and / or O-17.

[0172] Particularly preferred are those containing one or more compounds selected from the group of compounds of formula O-17.

[0173] The mixtures according to the invention very particularly preferably contain compounds of formulae O-10, O-12, O-16 and / or O-17, in particular in an amount of 5 to 30%.

[0174] Preferred compounds of formulae O-10 and O-17 are shown below.

[0175]

Chemical formula

[0176] The media according to the invention particularly preferably contain tricyclic compounds of formula O-10a and / or formula O-10b in combination with one or more bicyclic compounds of formulae O-17a to O-17d. The total proportion of the compounds of formula O-10a and / or O-10b in combination with one or more compounds selected from the bicyclic compounds of formulae O-17a to O-17d is 5 to 40%, very particularly preferably 15 to 35%.

[0177] Very particularly preferred mixtures contain compounds O-10a and O-17a.

[0178]

Chemical formula

[0179] Compounds O-10a and O-17a preferably exist in the mixture at a concentration of 15 to 35%, particularly preferably 15 to 25%, and particularly preferably 18 to 22% based on the total mixture.

[0180] A very particularly preferred mixture contains compounds O-10b and O-17a.

[0181]

Chemical formula

[0182] Compounds O-10b and O-17a preferably exist in the mixture at a concentration of 15 to 35%, particularly preferably 15 to 25%, and particularly preferably 18 to 22% based on the total mixture.

[0183] A very particularly preferred mixture contains the following three compounds.

[0184]

Chemical formula

[0185] Compounds O-10a, O-10b and O-17a preferably exist in the mixture at a concentration of 15 to 35%, particularly preferably 15 to 25%, and particularly preferably 18 to 22% based on the total mixture.

[0186] A preferred mixture contains at least one compound selected from the following group of compounds.

[0187]

Chemical formula

[0188] Preferably, in compounds O-6, O-7 and O-17, R 1represents alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms respectively, and R 2 represents alkenyl having 2 to 6 C atoms.

[0189] Preferred mixtures contain at least one compound of the formulas O-6a, O-6b, O-7a, O-7b, O-17e, O-17f, O-17g and O-17h:

[0190]

Chemical formula

[0191] The compounds of the formulas O-6, O-7 and O-17e to h are preferably present in the mixtures according to the invention in an amount of 1 to 40% by weight, preferably 2 to 35% by weight, very particularly preferably 2 to 30% by weight.

[0192] j) Preferred liquid crystal media according to the invention contain one or more substances containing tetrahydronaphthyl or naphthyl units, such as compounds of the formulas N-1 to N-5, etc.

[0193]

Chemical formula

[0194] k) Preferred mixtures comprise one or more compounds selected from the group of difluorodibenzochroman compounds of formula BC, chromans of formula CR, fluorinated phenanthrenes of formulas PH-1 and PH-2, and fluorinated dibenzofurans of formulas BF-1 and BF-2.

[0195]

Chemical formula

[0196] The mixtures according to the invention preferably contain the compounds of formula BC, CR, PH-1, PH-2 and / or BF in an amount of 3 to 20% by weight, in particular 3 to 15% by weight.

[0197] Particularly preferred compounds of formulas BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.)

[0198]

Chemical formula

[0199] A mixture containing one, two or three compounds of formula BC-2, BF-1 and / or BF-2 is considered to be very particularly preferred.

[0200] l) Preferred mixtures contain one or more indane compounds of formula In.

[0201]

Chem.

[0202] Preferred compounds of formula In are the compounds of formulae In-1 to In-16 shown below.

[0203]

Chem.

[0204] Compounds of formulae In-1, In-2, In-3 and In-4 are considered to be particularly preferred.

[0205] Compounds of formula In and sub-formulae In-1 to In-16 are preferably used in the mixtures according to the invention at a concentration of 5% by weight or more, in particular 5 to 30% by weight, very particularly preferably 5 to 25% by weight.

[0206] m) Preferred mixtures further contain one or more compounds of formulae L-1 to L-11.

[0207]

Chem.

[0208] The compounds of formulas L-1 to L-5 are preferably used at a concentration of 5 to 50% by weight, particularly 5 to 40% by weight, and very particularly preferably 10 to 40% by weight.

[0209] Preferably, the medium according to the present invention contains a stabilizer selected from the group of compounds of formulas ST-1 to ST-18.

[0210]

Chem.

[0211] Among the compounds of formula ST, the compounds of the following formula are particularly preferred.

[0212]

Chemical formula

[0213] In the compounds of formula ST-3a and ST-3b, n preferably represents 3. In the compounds of formula ST-2a, n preferably represents 7.

[0214] A very particularly preferred mixture according to the invention comprises one or more stabilizers from the group of compounds of formula ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12.

[0215]

Chemical formula

[0216] The compounds of formulas ST-1 to ST-18 are preferably each present in the liquid crystal mixture according to the invention in an amount of 0.005 to 0.5% based on the mixture.

[0217] When the mixture according to the invention contains two or more compounds from the group of compounds of formulas ST-1 to ST-18, in the case of two compounds, the concentration based on the mixture increases correspondingly to 0.01 to 1%.

[0218] However, the total proportion of the compounds of formulas ST-1 to ST-18 based on the mixture according to the invention should not exceed 2%.

[0219] A particularly preferred concept of the mixture is shown below: (The acronyms used are explained in Table A. n and m each independently of one another represent 1 to 15, preferably 1 to 6).

[0220] The mixture according to the invention preferably contains the following. - One or more compounds of formula IA selected from COB(S)-2-O2, COB(S)-2-O4 and COB(S)-4-O4, in a total concentration preferably in the range of 1% to 25%, more preferably 5% to 15%, particularly preferably 7% to 10%; and / or - One or more compounds of formulas IA, IIA and IIC, in a total concentration preferably in the range of 25% to 65%, more preferably 30% to 55%, particularly preferably 40% to 50%; and / or - One or more compounds of formulas IA, IIA, IID-4 and IIC, in a total concentration preferably in the range of 40% to 85%, more preferably 50% to 70%, particularly preferably 55% to 65%; and / or - One or more compounds of formulas IA, IIB and IIC, in a total concentration preferably in the range of 15% to 45%, more preferably 20% to 40%, particularly preferably 25% to 35%; and / or - One or more compounds of formula IA and IIB and IIC and IID-4, preferably at a total concentration in the range of 30% to 60%, more preferably 35% to 55%, particularly preferably 40% to 50%; and / or - One or more compounds of formula IA and formula IC, preferably at a total concentration in the range of 10% to 20%, particularly preferably 12% to 18%; and / or - One or more compounds of formula IA and IC and IIA, preferably at a total concentration in the range of 20% to 60%, preferably 40% to 50%; and / or - One or more compounds CY-n-Om, particularly CY-3-O4, CY-5-O4 and / or CY-3-O2, preferably at a total concentration in the range of 5% to 20%, preferably 10% to 17%; and / or - CPY-n-Om, particularly CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably at a concentration of preferably 5% or more, particularly 10 to 30%, based on the whole mixture; and / or - One or more compounds CCY-n-Om, preferably CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and / or CCY-5-O2, preferably at a concentration of preferably 5% or more, particularly 10 to 30%, based on the whole mixture; and / or - CLY-n-Om, preferably CLY-2-O4, CLY-3-O2, and / or CLY-3-O3, preferably at a concentration of preferably 5% or more, particularly 10 to 30%, very particularly preferably 15 to 20%, based on the whole mixture.

[0221] Furthermore, the mixture of the present invention containing the following is preferably provided: (n and m each independently represent 1 to 6.) - L 11 =L 12 =F, R 1 =alkyl, and R 1* =alkoxy, one or more compounds of formula IB; - At a concentration in the range of 1 to 20% by weight, more preferably 2 to 15% by weight, particularly preferably 3 to 12% by weight, and very particularly preferably 4 to 11% by weight, a compound of formula IB, preferably formulae IB-1 to IB-3, i.e., formulae IB-O-1 to IB-O-3 and / or IB-S-1 to IB-S-3, particularly the compounds LB-3-O4 and / or LB(S)-4-O3, - Based on the entire mixture, preferably at a concentration of 10 to 80%, CPY-n-Om and CY-n-Om, and / or - Based on the entire mixture, preferably at a concentration of 10 to 45%, CPY-n-Om and PY-n-Om, preferably CPY-2-O2 and / or CPY-3-O2 and PY-3-O2, and / or - Based on the entire mixture, preferably at a concentration of 10 to 80%, CPY-n-Om and CLY-n-Om, and / or - Based on the entire mixture, preferably at a concentration of 2 to 10%, CCVC-n-V, preferably CCVC-3-V, and / or - Based on the entire mixture, preferably at a concentration of 5 to 50%, CC-V-V.

[0222] In a particularly preferred embodiment of the present invention, the medium preferably contains one or more compounds of formula B-nO-Om and / or B(S)-nO-Om, particularly the compound B(S)-2O-O5, at a concentration in the range of 2 to 8%, and the compound CC-3-V at a concentration in the range of 25 to 40% by volume, and optionally the compound CC-3-V1 at a concentration in the range of 1 to 10%, preferably 2 to 5%.

[0223] The present invention further relates to an electro-optical display with active matrix addressing, which contains the liquid crystal medium according to claim 1 as a dielectric, and is characterized in that the display is a VA, SA-VA, IPS, U-IPS, FFS, UB-FFS, SA-FFS, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA, PS-TN, polymer-stabilized SA-VA or polymer-stabilized SA-FFS display.

[0224] The liquid crystal medium according to the invention preferably advantageously has a nematic phase at -20 °C or lower to 70 °C or higher, particularly preferably at -30 °C or lower to 80 °C or higher, and very particularly preferably at -40 °C or lower to 90 °C or higher.

[0225] The medium according to the invention has a clearing temperature of 80 °C or higher, preferably 85 °C or higher.

[0226] In this specification, the expression "having a nematic phase" means, on the one hand, that neither a smectic phase nor crystallization is observed at low temperatures corresponding to the temperature, and on the other hand, that no clearing occurs upon heating from the nematic phase. The investigation at low temperatures is carried out with a flow viscometer at the corresponding temperature and confirmed by storing in a test cell having a layer thickness corresponding to electro-optical applications for at least 100 hours. If the storage stability at a temperature of -20 °C of the corresponding test cell is 1000 hours or more, the medium is considered to be stable at this temperature. At temperatures of -30 °C and -40 °C, the corresponding times are 500 hours and 250 hours, respectively. At high temperatures, the clearing point is measured by a conventional method using a capillary.

[0227] The liquid crystal mixture preferably has a nematic phase range of at least 60 K and a flow viscosity ν of at most 30 mm 2 ·s -1 at 20 °C 20 and has.

[0228] The birefringence value Δn in the liquid crystal mixture is generally from 0.07 to 0.16, preferably from 0.08 to 0.13, and very preferably from 0.09 to 0.12.

[0229] In a preferred embodiment of the present invention, the medium has a birefringence in the range of 0.100 to 0.115, preferably 0.105 to 0.112.

[0230] In another preferred embodiment, the medium according to the present invention has a birefringence in the range of 0.100 or less, 0.070 to 0.098, preferably 0.085 to 0.095.

[0231] The liquid crystal mixture according to the present invention has a Δε of -0.5 to -8.0, particularly -2.5 to -6.0, where Δε represents the dielectric anisotropy. The rotational viscosity γ1 at 20 °C is preferably 150 mPa·s or less, particularly 120 mPa·s or less.

[0232] In a preferred embodiment, the rotational viscosity γ1 at 20 °C is 100 mPa·s or less, particularly 95 mPa·s or less.

[0233] The liquid crystal medium according to the present invention has a relatively low threshold voltage (V0) value. They are preferably in the range of 1.7 V to 3.0 V, particularly preferably 2.5 V or less, and very particularly preferably 2.3 V or less.

[0234] In the case of the present invention, the term "threshold voltage" relates to the capacitance threshold (V0), also called the Frederiks threshold, unless otherwise specified.

[0235] In addition, the liquid crystal medium according to the present invention has a high value for the voltage holding ratio in the liquid crystal cell.

[0236] Generally, a liquid crystal medium having a low address voltage or threshold voltage shows a lower voltage holding ratio than one having a high address voltage or threshold voltage, and vice versa.

[0237] In the present invention, the term "dielectrically positive compound" refers to a compound with Δε > 1.5, the term "dielectrically neutral compound" refers to a compound with -1.5 ≤ Δε ≤ 1.5, and the term "dielectrically negative compound" refers to a compound with Δε < -1.5. The dielectric anisotropy of a compound is determined here by dissolving 10% of the compound in a liquid crystal host and determining the capacitance of the resulting mixture in at least one test cell having a layer thickness of 20 μm and a homeotropic and homogeneous surface orientation at 1 kHz. The measurement voltage is usually 0.5 V to 1.0 V, but is always lower than the capacitance threshold of each liquid crystal mixture being investigated.

[0238] All temperature values given for the present invention are in °C.

[0239] The mixtures according to the invention are suitable for application to any VA-TFT, for example VAN, MVA, (S)-PVA, ASV, PSA (polymer sustained VA) and PS-VA (polymer stabilized VA). Furthermore, they are also suitable for application to IPS ( i n- p lane s witching) and FFS ( f ringe f ield s witching).

[0240] The nematic liquid crystal mixtures in the displays according to the invention generally comprise two components A and B, which themselves consist of one or more individual compounds.

[0241] Component A has a significantly negative dielectric anisotropy and gives a dielectric anisotropy of -0.5 or less in the nematic phase. It preferably comprises one or more compounds of formula I, in addition to compounds of formulae IIA, IIB and / or IIC, and furthermore one or more compounds of formula O-17.

[0242] The proportion of component A is preferably 45 to 100%, in particular 60 to 100%.

[0243] For component A, one (or more) individual compounds having a Δε value of -0.8 or less are selected. This value must be more negative the smaller the proportion of A in the whole mixture.

[0244] Component B has a significant nematogeneity and a kinematic viscosity at 20 °C of 30 mm 2 ·s -1 or less, preferably 25 mm 2 ·s -1 or less.

[0245] A number of suitable materials are known to the person skilled in the art from the literature. Compounds of formula O-17 are particularly preferred.

[0246] Particularly preferred individual compounds of component B are very low viscosity nematic liquid crystals having a kinematic viscosity at 20 °C of 18 mm 2 ·s -1 or less, preferably 12 mm 2 ·s -1 or less.

[0247] Component B is uniaxially or enantiotropically nematic, has no smectic phase and can prevent the occurrence of a smectic phase down to very low temperatures in the liquid crystal mixture. For example, when various highly nematogenic materials are added to a smectic liquid crystal mixture, the nematogenicity of these materials can be compared through the degree of suppression of the smectic phase achieved.

[0248] Optionally, the mixture may contain component C which comprises a compound having a dielectric anisotropy of Δε ≧ 1.5. These so-called positive compounds are generally present in the mixture with negative dielectric anisotropy in an amount of ≦ 20% by weight, based on the whole mixture.

[0249] In addition to one or more compounds of formula I, the phase preferably comprises compounds of formulae IIA, IIB and / or IIC with 4 to 15, in particular 5 to 12, particularly preferably < 10, and optionally one or more compounds of formula O-17.

[0250] Compounds of formula IB and compounds of formula IIA, IIB and / or IIC, and optionally in addition to O-17, other components may also be present in an amount up to 45% of the total mixture, preferably up to 35%, in particular up to 10%.

[0251] The other components are preferably selected from azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, phenyl or cyclohexyl cyclohexanecarboxylates, phenylcyclohexanes, cyclohexylbiphenyls, cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-biscyclohexylbiphenyls or cyclohexylpyrimidines, phenyl or cyclohexyldioxanes, optionally halogenated stilbenes, benzyl phenyl ethers, nematic or nematogenic substances from the class of trans and substituted cinnamic acid esters, in particular known substances.

[0252] The most important compounds suitable as components of this type of liquid crystal phase can be characterized by formula IV. R 20 -L-G-E-R 21 IV (wherein L and E each represent a carbocyclic or heterocyclic system from the group formed by 1,4-disubstituted benzene and cyclohexane rings, 4,4'-disubstituted biphenyls, phenylcyclohexanes and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidines and 1,3-dioxane rings, 2,6-disubstituted naphthalenes, di- and tetrahydronaphthalenes, quinazolines and tetrahydroquinazolines, G represents -CH=CH-, -N(O)=N-, -CH=CQ-, -CH=N(O)-, -C≡C-, -CH2-CH2-, -CO-O-, -CH2-O-, -CO-S-, -CH2-S-, -CH=N-, -COO-Phe-COO-, -CF2O-, -CF=CF-, -OCF2-, -OCH2-, -(CH2)4-, -(CH2)3O-, or represents a C-C single bond, Q represents a halogen, preferably chlorine, or represents -CN, and R 20 and R 21 each represent alkyl, alkenyl, alkoxy, alkoxyalkyl or alkoxycarbonyloxy having up to 18, preferably up to 8 carbon atoms, or one of these groups represents CN, NC, NO2, NCS, CF3, SF5, OCF3, F, Cl, or Br.)

[0253] In most of these compounds, R 20 and R 21 are different from each other, and one of these groups is usually an alkyl or alkoxy group. Other variants of the proposed substituents are also common. Many such substances or mixtures thereof are commercially available. All of these substances can be prepared by methods known from the literature.

[0254] It goes without saying for those skilled in the art that the VA, IPS or FFS mixtures of the present invention may also include compounds in which H, N, O, Cl and F are substituted with the corresponding isotopes.

[0255] The compounds of formula P are optionally added to the mixtures according to the invention, preferably in a concentration of from 0.01 to 5% by weight, particularly preferably from 0.2 to 2% by weight, based on the mixture. These mixtures can optionally also contain initiators, as described, for example, in US Pat. No. 6,781,665. Initiators, such as Irganox-1076 from BASF, are preferably added in an amount of from 0 to 1% to the mixtures containing polymerizable compounds. Mixtures of this kind can be used in the so-called polymer stabilization VA mode (PS-VA) or PSA (polymer sustained VA), where the polymerization of the reactive mesogen is intended to take place in the liquid crystal mixture after filling of the display panel. The prerequisite for this is that the liquid crystal compounds of the LC host do not react under the polymerization conditions of the reactive mesogen, i.e. generally upon exposure to UV in the wavelength range from 320 to 360 nm. For example, liquid crystal compounds containing alkenyl side chains, such as CC-3-V, do not show any reaction under the polymerization conditions of the RM (UV polymerization) and are therefore not considered as RM in this specification.

[0256] Preferred compounds of formula P are selected from the following formulas.

[0257]

Chemical formula

[0258] Particularly preferred compounds of formula P are the compounds of formulae P-2, P-13, P-17, P-22, P-23, P-24 and P-30.

[0259] Even more preferred are the tri-reactive compounds P-17 to P-31, in particular P-17, P-18, P-19, P-22, P-23, P-24, P-25, P-26, P-30 and P-31.

[0260] In the compounds of Formulas P-1 to P-31, TIFF2025098072000091.tif50166wherein L is, each occurrence, the same or different and has one of the meanings given above or 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, particularly F or CH3.

[0261] The mixture according to the invention may further contain conventional additives such as stabilizers, antioxidants, UV absorbers, nanoparticles, microparticles and the like.

[0262] The structure of the liquid crystal display according to the invention corresponds to a normal shape, as described, for example, in EP-0240379.

[0263] The following examples are intended to illustrate the invention without limiting it. In the above and below, percent data are given as weight percent; all temperatures are given in degrees Celsius.

[0264] Throughout this application, 1,4-cyclohexylene rings and 1,4-phenylene rings are depicted as follows:

[0265]

Chemical formula

[0266] Unless otherwise specified, the cyclohexylene ring is a trans-1,4-cyclohexylene ring.

[0267] Throughout this application and in the examples, the structures of the liquid crystal compounds are indicated by acronyms. Unless otherwise indicated, the conversion to chemical formulas is carried out according to Tables 1 to 3. All groups C n H 2n+1 、C m H 2m+1 and C m’ H2 m’+1 or C n H 2n and C m H 2m are each a linear alkyl group or an alkylene group, and in each case have n, m, m' or z carbon atoms, respectively. n, m, m', z each independently of one another represent 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, preferably 1, 2, 3, 4, 5 or 6. In Table 1, the ring elements of each compound are coded, in Table 2, the crosslinking elements are listed, and in Table 3, the meaning of the symbols of the side chains on the left or right hand side of the compound is shown.

[0268] Table 1: Ring elements

[0269]

Table 1

[0270] Table 2: Crosslinking elements

[0271]

Table 2

[0272] Table 3: Side chains

[0273]

Table 3

[0274] In addition to one or more compounds of formula I, the mixtures according to the invention preferably comprise one or more compounds among those mentioned in Table A below.

[0275] Table A The following abbreviations are used: (n, m, m’, z: each independently of one another 1, 2, 3, 4, 5 or 6; (O)C m H 2m+1 is OC m H 2m+1 or C m H 2m+1 .)

[0276] [Table 4] TIFF2025098072000099.tif200166 TIFF2025098072000100.tif196166 TIFF2025098072000101.tif198166 TIFF2025098072000102.tif187166 TIFF2025098072000103.tif190166 TIFF2025098072000104.tif203166 TIFF2025098072000105.tif213166 TIFF2025098072000106.tif195166 TIFF2025098072000107.tif205166 TIFF2025098072000108.tif194166 TIFF2025098072000109.tif185166 TIFF2025098072000110.tif191166 TIFF2025098072000111.tif183166 TIFF2025098072000112.tif170166 TIFF2025098072000113.tif199166 TIFF2025098072000114.tif199166 TIFF2025098072000115.tif196166 TIFF2025098072000116.tif196166 TIFF2025098072000117.tif194166 TIFF2025098072000118.tif207166 TIFF2025098072000119.tif206166 TIFF2025098072000120.tif203166 TIFF2025098072000121.tif198166 TIFF2025098072000122.tif224166

[0277] The liquid crystal mixture that can be used according to the present invention is prepared in a manner customary per se. Generally, the desired amounts of the components used in smaller amounts are advantageously dissolved in the components constituting the main component at elevated temperatures. It is also possible to mix the solution of the components with an organic solvent, such as acetone, chloroform or methanol, and after complete mixing, remove the solvent again, for example by distillation.

[0278] By means of suitable additives, the liquid crystal phase according to the invention can be modified so as to be usable, for example, in any of the types of ECB, VAN, IPS, GH or ASM-VA LCD displays disclosed hitherto.

[0279] Furthermore, the dielectric may also contain further additives known to those skilled in the art and described in the literature, such as, for example, UV absorbers, antioxidants, nanoparticles and free radical scavengers. For example, 0 to 15% of a dichroic dye, such as phenol, HALS( h indered a mine l ight s tabilisers), or a chiral dopant can be added. Stabilisers suitable for the mixtures according to the invention are, in particular, those listed in Table C.

[0280] For example, 0 to 15% of a dichroic dye may be added. Further, a conductive salt, preferably ethyl dimethyldodecylammonium 4-hexyloxybenzoate, tetrabutylammonium tetraphenylborate, or a complex salt of a crown ether (see, for example, Haller et al., Mol. Cryst. Liq. Cryst., Volume 24, pages 249-258 (1973)) may be added to improve the conductivity, or substances may be added to modify the dielectric anisotropy, viscosity and / or the orientation of the nematic phase. Substances of this kind are described, for example, in DE-A2209127, 2240864, 2321632, 2338281, 2450088, 2637430, 2853728.

[0281] Table B Table B shows possible dopants that can be added to the mixtures according to the invention. If the mixture contains a dopant, it is added in an amount of 0.01 to 4% by weight, preferably 0.01 to 3% by weight.

[0282]

Table 5

[0283] The mixtures according to the invention contain at least one stabilizer from Table C given below.

[0284] Table C For example, stabilizers that can be added to the mixtures according to the invention in an amount of 0 to 10% by weight, preferably 0.001 to 5% by weight, in particular 0.001 to 1% by weight, are shown below.

[0285]

Table 6

[0286] Table D Table D shows exemplary reactive mesogenic compounds of formula P that can be used in the LC medium according to the present invention.

[0287] [Table 7] TIFF2025098072000134.tif177166TIFF2025098072000135.tif164166TIFF2025098072000136.tif164166TIFF2025098072000137.tif166166 TIFF2025098072000138.tif185166 TIFF2025098072000139.tif190166 TIFF2025098072000140.tif207166 TIFF2025098072000141.tif173166 TIFF2025098072000142.tif158166 TIFF2025098072000143.tif166166 TIFF2025098072000144.tif190166TIFF2025098072000145.tif180166 TIFF2025098072000146.tif194166TIFF2025098072000147.tif178166 TIFF2025098072000148.tif161166 TIFF2025098072000149.tif191166 TIFF2025098072000150.tif181166 TIFF2025098072000151.tif174166 TIFF2025098072000152.tif136166 TIFF2025098072000153.tif158166 TIFF2025098072000154.tif196166TIFF2025098072000155.tif168166 TIFF2025098072000156.tif195166

[0288] In a preferred embodiment, the mixture according to the invention preferably comprises one or more polymerizable compounds selected from the polymerizable compounds of formulas RM-1 to RM-131. Among these, the compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-43, RM-47, RM-49, RM-51, RM-59, RM-69, RM-71, RM-83, RM-97, RM-98, RM-104, RM-112, RM-115, RM-116, and RM-128 are particularly preferred.

Examples

[0289] Examples: The following examples are intended to illustrate the invention without limiting it. In the examples, m.p. indicates the melting point, C indicates the clearing point of the liquid crystal substance in degrees Celsius; the boiling point is indicated by m.p. Further: C indicates a crystalline solid state, S indicates a smectic phase (the subscript indicates the type of phase), N indicates a nematic state, Ch indicates a cholesteric phase, I indicates an isotropic phase, Tg indicates the glass transition temperature. The number between two symbols indicates the transition temperature in degrees Celsius.

[0290] The host mixture used for the determination of the optical anisotropy Δn of the compound of formula IB is the commercially available mixture ZLI-4792 (Merck KGaA). The dielectric anisotropy Δε is determined using the commercially available mixture ZLI-2857. The physical data of the compounds investigated are obtained from the change in the dielectric constant of the host mixture after the addition of the compounds investigated and extrapolation to 100% of the compounds used. Generally, depending on solubility, 10% of the compounds investigated are dissolved in the host mixture.

[0291] Unless otherwise indicated, parts or percentage data indicate parts by weight or percentages by weight.

[0292] In the above and below: V o represents the threshold voltage at 20°C, capacitance [V], n e represents the extraordinary refractive index at 20°C and 589 nm, n o represents the normal refractive index at 20 °C and 589 nm, Δn represents the optical anisotropy at 20 °C and 589 nm, ε ⊥ represents the dielectric constant perpendicular to the director at 20 °C and 1 kHz, ε || represents the dielectric constant parallel to the director at 20 °C and 1 kHz, Δε represents the dielectric anisotropy at 20 °C and 1 kHz, cl.p., T(N, I) represent the clearing point [°C], γ1 represents the rotational viscosity [mPa·s] measured at 20 °C and determined by the method of rotation in a magnetic field, K1 represents the elastic constant, "spray" deformation [pN] at 20 °C, K2 represents the elastic constant, "twist" deformation [pN] at 20 °C, K3 represents the elastic constant, "bend" deformation [pN] at 20 °C, and LTS represents the low-temperature stability (nematic phase) and is determined in the test cell or bulk as specified.

[0293] Unless otherwise specified, all values shown in this application with respect to temperature, for example, the melting point T(C, N), the transition T(S, N) from the smectic (S) phase to the nematic (N) phase, and the clearing point T(N, I) or cl.p., are shown in degrees Celsius (°C). M.p. represents the melting point. Further, Tg = glassy state, C = crystalline state, N = nematic phase, S = smectic phase, and I = isotropic phase. The numbers between these symbols represent the transition temperature.

[0294] Unless otherwise specified, the term "threshold voltage" for the present invention relates to the capacitance threshold (V0), also called the Frederiks threshold. In the examples, as is generally usual, the optical threshold can also be shown for a relative contrast of 10% (V 10 ).

[0295] The displays used for measuring the capacitance threshold voltage each consist of two parallel planar glass outer plates spaced 20 μm apart, each having an electrode layer on the inside and an unrubbed polyimide alignment layer that provides a homeotropic edge alignment of liquid crystal molecules.

[0296] The displays or test cells used for measuring the tilt angle each consist of two parallel planar glass outer plates spaced 4 μm apart, each having an electrode layer and a polyimide alignment layer on the inside, where the two polyimide layers are rubbed antiparallel to each other, providing a homeotropic edge alignment of liquid crystal molecules.

[0297] Unless otherwise specified, VHR is determined at 20 °C (VHR 20 ) and after 5 minutes in an oven at 100 °C (VHR 100 ) by a commercially available instrument Model 6254 manufactured by Toyo Technica (Japan). The frequency of the voltage used is in the range of 1 Hz to 60 Hz unless more precisely indicated.

[0298] The accuracy of the VHR measurement values depends on each value of VHR. As the value decreases, the accuracy decreases. The deviations generally observed for values in various size ranges are summarized in order of size in the following table.

[0299]

Table 8

[0300] The stability against UV irradiation is investigated in a "Suntest CPS" commercially available from Heraeus in Germany. The sealed test cell is irradiated for 30 minutes to 2.0 hours without additional heating unless explicitly indicated. The irradiation power in the wavelength range of 300 nm to 800 nm is 765 W / m 2It is V. To simulate the so-called window glass mode, a UV “cut-off” filter having an edge wavelength of 310 nm is used. In each series of experiments, at least 4 test cells are investigated for each condition, and each result is shown as the average of the corresponding individual measurements.

[0301] The decrease in the voltage holding ratio (ΔVHR) is usually caused by, for example, exposure to UV irradiation or an LCD backlight, and is determined according to the following formula (1): TIFF2025098072000158.tif10166

[0302] To investigate the low temperature stability (LTS), that is, the stability of the LC mixture in the bulk against the spontaneous crystallization of individual components or the generation of a smectic phase at low temperatures, several sealed bottles each containing about 1 g of material are typically stored at one or more predetermined temperatures of -10 °C, -20 °C, -30 °C, and / or -40 °C, and visually inspected at regular intervals to see if a phase transition is observed. As soon as the first of the samples at a given temperature shows a change, the change time is recorded. The time until the last inspection at which no change has been observed is recorded as the respective LTS.

[0303] The ion density for which the resistivity is calculated is measured using a VHR test cell with AL16301 polyimide (JSR Corporation, Japan) having a cell gap of 3.2 μm, using an LC material property measurement system Model 6254 commercially available from Toyo Technica, Japan. The measurement is performed after storing in an oven at 60 °C or 100 °C for 5 minutes.

[0304] The so-called “HTP” indicates the helical twisting power (μm) of an optically active or chiral substance in an LC medium. Unless otherwise specified, HTP is measured at a temperature of 20 °C in a commercially available nematic LC host mixture MLD-6260 (Merck KGaA).

[0305] Unless otherwise specified, all concentrations in this application are expressed as weight percentages and relate to the entire corresponding mixture, excluding solvents and including all solid or liquid crystal components. All physical properties are determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", November 1997, Merck KGaA, Germany, and apply at a temperature of 20 °C unless otherwise specified.

[0306] The following mixing examples with negative dielectric anisotropy are particularly suitable for, for example, at least one planar alignment layer liquid crystal displays such as IPS and FFS displays, especially UB-FFS (= ultra-high brightness FFS), and VA displays.

[0307] Mixture examples and comparative examples Comparative mixture C1 are prepared as follows:

[0308]

Table 9

[0309] Mixture M1 are prepared as follows:

[0310]

Table 10

[0311] Mixture M2 are prepared as follows:

[0312]

Table 11

[0313] Mixture M3 are prepared as follows:

[0314]

Table 12

[0315] Mixture M4 is prepared as follows:

[0316] [Table 13]

[0317] Mixture M5 is prepared as follows:

[0318] [Table 14]

[0319] Mixture M6 is prepared as follows:

[0320] [Table 15]

[0321] Mixture M7 is prepared as follows:

[0322] [Table 16]

[0323] As shown in the following table, the VHRs of mixtures C1 and M1 - M6 were measured (VHR test cell with UV - PI for planar alignment, cell gap 4.0 μm, 1 V, 1 Hz, 60 °C). The values were measured immediately after filling the test cell.

[0324] [Table 17]

[0325] Surprisingly, the use of the compound of formula IA in the medium according to the invention results in a liquid crystal mixture having a VHR at least as high as that of the reference mixture C1. At the same time, compared to C1, the medium according to the invention exhibits a lower rotational viscosity. Thus, it is possible to realize a medium with improved response time without adversely affecting reliability.

[0326] Mixture M8 is prepared as follows:

[0327]

Table 18

[0328] Medium M8 is distinguished by a particularly low rotational viscosity that enables an LC display with a surprisingly short switching time.

[0329] Mixture M9

[0330]

Table 19

[0331] Mixture M10 Mixture M10 consists of 99.96% of mixture M9 and 0.04% of the compound ST-3a-1 shown above.

[0332] Mixture M11

[0333]

Table 20

[0334] Mixture M12 Mixture M12 consists of 99.965% of mixture M11 and 0.035% of the compound ST-3a-1 shown above.

[0335] Mixture M13

[0336]

Table 21

[0337] Mixture M14 Mixture M14 consists of 99.965% of mixture M13 and 0.035% of the compound ST-3a-1 shown above.

[0338] Mixture M15

[0339]

Table 22

[0340] Mixture M16 Mixture M16 consists of 99.965% of mixture M15 and 0.035% of the compound ST-3a-1 shown above.

[0341] Mixture M17

[0342]

Table 23

[0343] Mixture M18

[0344]

Table 24

[0345] Mixture M19 TIFF2025098072000175.tif138166

[0346] Mixture M20

[0347]

Table 25

[0348] Mixture M21

[0349]

Table 26

[0350] Mixture M22

[0351]

Table 27

[0352] Mixture M23

[0353]

Table 28

[0354] Mixture M24

[0355]

Table 29

[0356] Mixture M25

[0357]

Table 30

[0358] Mixture M26

[0359]

Table 31

[0360] Mixture M27

[0361]

Table 32

[0362] Mixture M28

[0363]

Table 33

[0364] Mixture M29 Mixture M29 consists of 99.975% of mixture M28 and 0.025% of the compound ST-3a-1 shown above.

[0365] Mixture M30

[0366]

Table 34

[0367] Mixture M31

[0368]

Table 35

[0369] Mixture M32

[0370]

Table 36

[0371] Mixture M33

[0372]

Table 37

[0373] Mixture M34

[0374]

Table 38

[0375] Mixture M35

[0376]

Table 39

[0377] Mixture M36

[0378]

Table 40

[0379] Mixture M37

[0380]

Table 41

[0381] Mixture M38

[0382]

Table 42

[0383] Mixture M39

[0384]

Table 43

[0385] Mixture M40

[0386]

Table 44

[0387] Mixture M41

[0388]

Table 45

[0389] Mixture M42

[0390]

Table 46

[0391] Mixture M43

[0392]

Table 47

[0393] Mixture M44

[0394]

Table 48

[0395] Mixture M45

[0396]

Table 49

[0397] Mixture M46

[0398]

Table 50

[0399] Mixture M47

[0400]

Table 51

[0401] Mixture M48

[0402]

Table 52

[0403] Mixture M49

[0404]

Table 53

[0405] Mixture M50

[0406]

Table 54

[0407] Mixture M51

[0408]

Table 55

[0409] Mixture M52

[0410]

Table 56

[0411] Mixture M53

[0412]

Table 57

[0413] Mixture M54

[0414]

Table 58

[0415] Mixture M55

[0416]

Table 59

[0417] Mixture M56

[0418]

Table 60

[0419] Mixture M57

[0420]

Table 61

[0421] Mixture M58

[0422]

Table 62

[0423] Mixture M59

[0424]

Table 63

[0425] Mixture M60

[0426]

Table 64

[0427] Mixture M61

[0428]

Table 65

[0429] Mixture M62

[0430]

Table 66

[0431] Mixture M63

[0432]

Table 67

[0433] Mixture M64

[0434]

Table 68

[0435] Mixture M65

[0436]

Table 69

[0437] Mixture M66

[0438]

Table 70

[0439] Mixture M67

[0440]

Table 71

[0441] Mixture M68

[0442]

Table 72

[0443] Mixture M69

[0444]

Table 73

[0445] Mixture M70

[0446]

Table 74

[0447] Mixture M71

[0448]

Table 75

[0449] Mixture M72

[0450]

Table 76

[0451] Mixture M73

[0452]

Table 77

[0453] Mixture M74

[0454]

Table 78

[0455] Mixture M75

[0456]

Table 79

[0457] Mixture M76

[0458]

Table 80

[0459] Mixture M77

[0460]

Table 81

[0461] Mixture M78

[0462]

Table 82

[0463] Mixture M79

[0464]

Table 83

[0465] Mixture M80

[0466]

Table 84

[0467] Mixture M81

[0468]

Table 85

[0469] Mixture M82

[0470]

Table 86

[0471] Mixture M83

[0472]

Table 87

[0473] Mixture M84

[0474]

Table 88

Claims

1. It is characterized in that it comprises one or more compounds of formula IA, 【Chemistry 1】 During the ceremony, R １１ , R １２ are the same or different and represent H, an alkyl or alkoxy group having 1 to 15 C atoms, where one or more of the CH ２ The groups are each independently -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, 【change】 O atoms may be substituted by -O-, -CO-O- or -O-CO- so as not to be directly bonded to each other, and one or more H atoms may be substituted by halogen; liquid crystal medium.

2. R in Formula IA １１ and R １２ 2. The medium according to claim 1, wherein the radicals, which may be the same or different, denote alkyl, alkenyl or alkoxy having 1 to 7 C atoms.

3. R in Formula IA １２ 3. The medium according to claim 1 or 2, wherein the radical denotes alkoxy having 1 to 7 C atoms.

4. A medium according to any one of claims 1 to 3, in which the total concentration of one or more compounds of formula IA ranges from 1% to 25% by weight.

5. The medium comprises one or more compounds selected from the group of compounds of formula IIA, IIB, IIC and IID, 【Chemistry 2】 During the ceremony, R ２Ａ , R ２Ｂ , R ２Ｃ and R ２Ｄ are each independently H, unsubstituted, CN or CF ３ or at least one halogen, and furthermore, in these groups, one or more CH ２ The groups are -O-, -S-, 【change】 -C≡C-, -CF ２ O-, -OCF ２ The O atoms may be substituted by -, -OC-O- or -O-CO- in such a way that they are not directly bonded to each other, L １ From L ４ each independently represents F or Cl, Z ２ , Z ２Ｂ , and Z ２Ｄ are each independently a single bond, -CH ２ CH ２ -, -CH=CH-, -CF ２ O-, -OCF ２ --, --CH ２ O-, -OCH ２ -, -COO-, -OCO-, -C ２ F ４ -, -CF=CF-, or -CH=CHCH ２ Shows O-, p represents 0, 1 or 2; q represents 0 or 1, and v represents 1 to 6; The medium according to any one of claims 1 to 4.

6. The medium comprises one or more compounds of formula IC, 【Chemistry 3】 During the ceremony, R １１ and R １２ each independently of the other denotes H, an alkyl or alkoxy group having 1 to 15 C atoms, and furthermore one or more of these groups may be CH ２ The groups are each independently -C≡C-, -CF ２ O-, -OCF ２ -, -CH=CH-, 【change】 O atoms may be replaced by -O-, -CO-O- or -O-CO- in such a way that they are not directly bonded to each other, and further, one or more H atoms may be replaced by halogen; X １ represents S or O, and L １１ and L １２ are each independently F, Cl, CF ３ or CHF ２ Showing, The medium according to any one of claims 1 to 5.

7. In formula IC: X １ denotes S, R １１ and R １２ each independently of the other denotes an alkyl, alkenyl or alkoxy group having up to 15 C atoms, and L １１ and L １２ The medium according to claim 6 , wherein both of the above represent F.

8. The medium further comprises one or more compounds selected from the group of compounds of formulae O-1 to O-18, 【Chemistry 4】 【change】 During the ceremony, R １ and R ２ are each independently R of claim 5. ２Ａ has the meaning given to 8. The liquid-crystalline medium according to claim 1 .

9. The medium further comprises one or more compounds selected from the group of compounds of formulae T-1 to T-21, 【Chemistry 5】 【change】 【change】 【change】 During the ceremony, R denotes a linear alkyl or alkoxy group having 1 to 6 C atoms, (O) denotes -O- or a single bond, m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4, 9. The liquid-crystalline medium according to claim 1 .

10. The medium comprises one or more polymerizable compounds of formula P, P-Sp-A １ -(Z １ -A ２ ) ｚ -R P During the ceremony, P represents a polymerizable group; Sp represents a spacer group or a single bond; A １ , A ２ represents an aromatic, heteroaromatic, alicyclic or heteroaliphatic group, which may contain fused rings, and which is unsubstituted or mono- or polysubstituted by L; Z １ is selected from -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH ２ -, -CH ２ O-, -SCH ２ -, -CH ２ S-, -CF ２ O-, -OCF ２ -, -CF ２ S-, -SCF ２ -, -(CH ２ ) ｎ１ -, -CF ２ CH ２ -, -CH ２ CF ２ -, -(CF ２ ) ｎ１ -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH ２ -CH ２ -CO-O-, -O-CO-CH ２ -CH ２ -, -CR ０ R ００ - or a single bond, R ０ , R ００ are the same or different and represent H or alkyl having 1 to 12 C atoms, R represents H, L, or P-Sp-; L represents F, Cl, -CN, P-Sp-, or a linear, branched or cyclic alkyl having 1 to 25 C atoms, where one or more non-adjacent CH ２ the group is optionally substituted 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 optionally one or more H atoms are replaced by P-Sp-, F or Cl, respectively; z represents 0, 1, 2 or 3; n1 represents 1, 2, 3, or 4; 10. The liquid-crystalline medium according to claim 1 .

11. LC medium according to claim 10, wherein the polymerisable compounds of the formula P are polymerised.

12. A process for the preparation of an LC medium according to any one of claims 1 to 9, comprising the step of mixing one or more compounds of formula IA according to claim 1 with one or more mesogenic or liquid crystalline compounds, and optionally a polymerisable compound according to claim 10, and optionally one or more additives.

13. LC display comprising a medium according to any one of the preceding claims.

14. 14. The LC display of claim 13, wherein the display is a PSA display.

15. 15. The LC display of claim 14, wherein the display is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA, PS-TN, polymer stabilized SA-VA, or polymer stabilized SA-FFS display.

16. 14. The LC display of claim 13, wherein the display is a VA, IPS, U-IPS, FFS, UB-FFS, SA-FFS, or SA-VA display.

17. Use of a liquid-crystalline medium according to any one of claims 1 to 11 in an electro-optical display.

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