Liquid crystal medium

Abstract

The present invention relates to a liquid crystal (LC) medium comprising a polymerizable compound, the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays, in particular in LC displays of the PSA (polymer stabilized alignment) or SA (self-alignment) type, LC displays of PSA or SA mode comprising the LC medium, and a method for manufacturing the LC display.

Description

[0001] This application is a divisional application of Chinese patent application No. 202111351546.8, filed on November 16, 2021, entitled "Liquid Crystal Medium". Technical Field

[0002] This invention relates to a liquid crystal (LC) medium comprising a polymerizable compound for optical, electro-optical and electronic purposes, particularly for use in LC displays, especially in PSA (polymer-stabilized alignment) or SA (self-alignment) type LC displays, a PSA or SA mode LC display comprising the LC medium, and a method for manufacturing the LC display. Background Technology

[0003] The proliferation of 8K and gaming monitors has led to increased demand for LC display (LCD) panels with higher refresh rates, and consequently, for LC media with faster response times. Many of these LCD panels use polymer-stabilized (PS) or polymer-stabilized alignment (PSA) modes, such as PS-VA (vertically aligned), PS-IPS (in-plane switching), or PS-FFS (edge ​​field switching) modes or their derivatives, or self-aligned (SA) modes such as SA-VA, which are polymer-stabilized.

[0004] In PS or PSA mode, a small amount, typically 0.1-1%, of one or more polymerizable mesocrystalline compounds (also known as RM (reactive mesocrystalline)) is added to the LC medium. After the LC medium is filled into the display, the RM is then polymerized in situ by UV photopolymerization while a voltage is applied to the electrodes of the display. This creates a small tilt angle in the LC molecules of the LC medium, which is stabilized by the polymerized RM. The UV polymerization method (also known as the "PSA method") is typically carried out in two steps: a first UV exposure step ("UV1 step"), in which a voltage is applied to create the tilt angle, and a second UV exposure step ("UV2 step"), in which no voltage is applied, to complete the RM polymerization.

[0005] In SA-VA mode, the alignment layer is omitted from the display. Instead, a small amount, typically 0.1–2.5%, of self-aligning (SA) additive is added to the LC medium. This initiates the desired alignment, such as vertical or planar alignment, in situ via a self-assembly mechanism. SA additives typically contain an organic mesocrystalline core group with one or more polar anchoring groups, such as hydroxyl, carboxyl, amino, or thiol groups, attached thereto. These groups interact with the substrate surface, leading to additive alignment on the substrate surface and inducing the desired alignment within the LC molecules. SA additives may also contain one or more polymerizable groups, which can be polymerized under conditions similar to the RM used in the PSA method. In addition to the SA additive, the LC medium also contains one or more RMs.

[0006] One approach to reducing the response time of the LC medium to the PSA mode is, for example, by using alkenyl compounds as components of the LC host mixture. However, this can lead to reduced reliability of the mixture when exposed to the UV light required for polymerizing RM additives, which is believed to be caused by the reaction of the alkenyl compound with the polyimide in the alignment layer, particularly problematic when using shorter UV wavelengths less than 320 nm. Therefore, there is a trend towards using longer UV wavelengths for the PSA method.

[0007] Another way to reduce response time in LC media used in PSA mode is by adjusting the cell gap towards a higher / lower gap.

[0008] The use of UV-LED lamps in the PSA process is also recommended because they exhibit lower energy consumption, longer lifespan, and more efficient light energy transfer to the LC medium due to their narrower emission peaks, which allows for reduced UV intensity and / or UV irradiation time. This can shorten cycle time and save energy and production costs. Currently available UV lamps have higher wavelength emission, for example, at 365 nm.

[0009] Therefore, there is a need for polymerizable LC media for PSA or SA displays that possess high specific resistivity, a wide operating temperature range, short response time (even at low temperatures), low threshold voltage, low tilt angle, high tilt stability, multiple grayscale levels, high contrast, and wide viewing angle; high reliability and high VHR value after UV exposure; and, in the case of polymerizable compounds, low melting point and high solubility in the LC bulk mixture, enabling polymerization even at longer UV wavelengths. For displays used in mobile applications, there is a particular demand for LC media that exhibit low threshold voltage and high birefringence. Summary of the Invention

[0010] The present invention aims to provide novel suitable materials, particularly RM and LC media containing RM, for use in PSA or SA displays, which do not have the aforementioned disadvantages or have the aforementioned disadvantages to a reduced extent.

[0011] Specifically, the present invention is based on the following objectives: to include an LC medium containing an RM for use in PSA or SA displays, which can have very high resistivity, high VHR, high reliability, low threshold voltage, short response time, high birefringence, and good UV absorption at longer UV wavelengths, preferably 340-380 nm; to enable rapid and complete polymerization of the RM; to produce a low tilt angle, preferably as quickly as possible; to have high tilt stability; to reduce or prevent “image stickiness” and “ODF inhomogeneity (mura)” in the display, even after longer time and / or after UV exposure; and to exhibit high solubility in the LC medium, which is typically used as the main mixture for PSA or SA displays, provided that the RM is polymerized as quickly and completely as possible.

[0012] Another object of the present invention is to provide an LC medium for PSA displays, wherein the RM exhibits both a fast polymerization rate and good reliability parameters, such as high VHR or tilt stability.

[0013] Another object of the present invention is to provide novel LC media containing RM, particularly for optical, electro-optical and electronic applications, as well as suitable methods and intermediates for their preparation.

[0014] It has been found that one or more of these purposes can be achieved by providing LC media as described herein and for which protection is sought.

[0015] The present invention also relates to an LC medium, comprising

[0016] - Polymerizable component A), comprising, preferably, one or more polymerizable compounds, and

[0017] -Liquid crystal component B), hereinafter also referred to as "LC host mixture", comprises, preferably, one or more mesocrystalline or liquid crystal compounds,

[0018] Component B) comprises one or more compounds of formula IA, one or more compounds of formula IB, and one or more compounds of formula IC.

[0019]

[0020]

[0021] Each group, appearing identically or differently each time, and independently of the others, has the following meaning:

[0022] R 1 R 2 It is a straight-chain, branched, or cyclic alkyl group having 1-25 carbon atoms, wherein one or more non-adjacent CH2- groups are optionally surrounded by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -,-C≡C-, The O- and / or S- atoms are replaced in such a way that they are not directly connected to each other, and one or more H atoms are optionally replaced by F or Cl, preferably alkyl or alkoxy atoms having 1-6 C atoms.

[0023] R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms.

[0024] L 1 L 2 The preferred form is F or Cl, with F being preferred.

[0025] The alkyl group is an alkyl group having 1 to 7 carbon atoms, preferably having 2 to 5 carbon atoms, and particularly preferably n-propyl.

[0026] alkenyl is an alkenyl group having 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms, and particularly preferably vinyl or 1-propenyl.

[0027] Wherein, the proportion of compound of formula IA in component B) of the LC medium is >5% by weight, preferably >8% by weight.

[0028] The liquid crystal component B of the LC medium according to the invention is also referred to below as the "LC host mixture" and preferably contains only LC compounds selected from non-polymerizable low molecular weight compounds, such as compounds of formula IA, IB or IC, and optionally contains additives such as polymerization initiators, inhibitors, etc.

[0029] The present invention also relates to LC media or LC displays as described above and below, wherein the polymerizable compound of component A) is polymerized.

[0030] The present invention also relates to a method for preparing LC media as described above and below, the method comprising the steps of mixing one or more compounds of formula IA, IB and IC, or LC host mixtures or LC components B as described above and below, with one or more polymerizable compounds and optionally other LC compounds and / or additives.

[0031] The present invention also relates to the use of LC media in LC displays, particularly in LC displays in PSA or SA modes.

[0032] The present invention also relates to the use of the LC medium according to the invention in a PSA display, particularly in a PSA display containing an LC medium, for generating a tilt angle in the LC medium by in-situ polymerization of a polymerizable compound of component B in the PSA display, preferably in an electric or magnetic field.

[0033] The present invention also relates to an LC display comprising one or more compounds of formula I or an LC medium according to the present invention, preferably a PSA display, and very preferably a PS-VA, PS-IPS or PS-UB-FFS display.

[0034] The present invention further relates to an LC display comprising an LC medium as described in the context, wherein the polymerizable compound is present in a polymeric form, preferably a PSA or SA display, and very preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display.

[0035] The present invention further relates to a PSA-type LC display comprising two substrates, at least one of which is transparent to light, an electrode disposed on each substrate, or two electrodes disposed on only one substrate, and a layer of LC dielectric as described in the context located between the substrates, wherein a polymerizable compound is polymerized between the substrates of the display by UV light polymerization.

[0036] The present invention also relates to a method of manufacturing an LC display as described in the context, comprising the steps of: filling or otherwise providing an LC medium as described in the context between substrates of the display, and polymerizing a polymerizable compound, preferably simultaneously applying a voltage to electrodes of the display.

[0037] The present invention further relates to a method for manufacturing an LC display as described in the context, wherein the irradiation of the polymerizable compound is performed using a UV-LED lamp.

[0038] When used in a PSA display, the LC medium according to the invention exhibits one or more of the following advantageous characteristics:

[0039] -High transmittance,

[0040] High contrast,

[0041] - Reduced image stickiness

[0042] - Reduced ODF inhomogeneity

[0043] - Reduced rotational viscosity,

[0044] - High reliability and high VHR value after UV exposure and / or heat treatment

[0045] -Fast response time

[0046] - A strong tilt occurs within a certain process window.

[0047] - Rapid polymerization results in the lowest possible residual RM level after UV treatment.

[0048] - Good tilt stability.

[0049] As described below, alkenyl groups in compounds of formula IA, IB, II, or other components of the LC medium are not considered within the meaning of the term "polymerizable group" as used herein. Preferably, the polymerization conditions of the polymerizable compounds in the LC medium are selected such that alkenyl substituents do not participate in the polymerization reaction. Preferably, the LC media disclosed and claimed in this application do not contain additives that initiate or enhance the participation of alkenyl groups in the polymerization reaction.

[0050] Unless otherwise stated, polymerizable compounds and compounds of formula II are preferably selected from achiral compounds.

[0051] As used herein, the expression “UV light with wavelength of…” followed by a wavelength range (in nm), or a given lower or upper wavelength limit (in nm), indicates that the UV emission spectrum of the corresponding irradiation source has an emission peak, which is preferably the highest peak in the corresponding spectrum within the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit, and / or the UV absorption spectrum of the corresponding chemical compound has a long wavelength tail or a short wavelength tail extending into the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit.

[0052] As used herein, the term "substantially transmittant" means that the filter transmits a substantial portion, preferably at least 50% of the intensity, of incident light at the desired wavelength. As used herein, the term "substantially blocking" means that the filter does not transmit a substantial portion, preferably at least 50% of the intensity, of incident light at the undesired wavelength. As used herein, the term "desired (undesired) wavelength" refers, for example, to wavelengths within (outside) a given range λ for a bandpass filter, and to wavelengths above (below) a given value λ for a cutoff filter.

[0053] As used herein, the terms “active layer” and “switchable layer” refer to layers in electro-optic displays, such as LC displays, which contain one or more molecules with structural and optical anisotropy, such as LC molecules, that change their orientation when subjected to external stimuli such as an electric or magnetic field, resulting in a change in the layer’s transmittance to polarized or unpolarized light.

[0054] As used herein, the terms “tilt” and “tilt angle” should be understood to refer to the tilted orientation of LC molecules of the LC medium relative to the cell surface in an LC display (preferably a PSA display), and should be understood to include “pre-tilt” and “pre-tilt angle”. The tilt angle described herein represents the average angle (<90°) between the longitudinal molecular axis (LC director) of the LC molecules and the planar parallel outer surface forming the LC cell. Low absolute tilt angles (i.e., significantly deviating from 90°) correspond to large tilts. Suitable methods for measuring tilt angles are provided in the embodiments. Unless otherwise stated, tilt angle values ​​disclosed in the context are related to this measurement method.

[0055] As used herein, the terms “reactive mesocrystalline” and “RM” should be understood to refer to a compound containing a mesocrystalline or liquid crystal framework and one or more polymerizable functional groups attached thereto, and said functional groups are also referred to as “polymerizable groups” or “P”.

[0056] Unless otherwise stated, the term “polymerizable compound” as used herein should be understood to mean polymerizable monomeric compound.

[0057] The SA-VA display of this invention will be of polymer-stabilized mode because it comprises an LC medium containing RMs of formulas I and II or is manufactured using an LC medium containing RMs of formulas I and II. Therefore, as used herein, unless explicitly mentioned, the term "SA-VA display" should be understood to refer to a polymer-stabilized SA-VA display when referring to the display of this invention.

[0058] As used herein, the term “low molecular weight compound” should be understood to mean a monomer and / or a compound not prepared by polymerization, as opposed to “polymeric compound” or “polymer”.

[0059] As used herein, the term "non-polymerizable compound" will be understood to mean a compound that does not contain functional groups suitable for polymerization under the conditions typically applied to RM polymerization.

[0060] As used herein, the term "mesocrystalline group" is known to those skilled in the art and described in the literature, and it refers to a group that substantially contributes to the formation of a liquid crystal (LC) phase in a low molecular weight or polymeric substance due to the anisotropy of its attractive and repulsive interactions. A compound containing a mesocrystalline group (mesocrystalline compound) does not necessarily have an LC phase by itself. Mesocrystalline compounds can exhibit LC phase behavior only when mixed with other compounds and / or after polymerization. Typical mesocrystalline groups are, for example, rigid rod-shaped or disk-shaped units. Terms and definitions used in connection with mesocrystalline or LC compounds are given in Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.

[0061] As used herein, the term "spacer group" (hereinafter also referred to as "Sp") is known to those skilled in the art and described in the literature, see, for example, Pure Appl. Chem. 2001, 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 group" means a flexible group, such as an alkylene group, attached to a mesocrystalline or polymerizable group in a polymerizable mesocrystalline compound. In the context, Represents the trans-1,4-cyclohexyl ring, and It represents a 1,4-phenylene ring.

[0062] In groups In this system, the single bond between the two ring atoms can be attached to any free position on the benzene ring.

[0063] If the group R in the formula is shown in the context 1-12 ,R Q R or L represents alkyl and / or alkoxy, and it can be straight-chain or branched. It is preferably straight-chain, having 2, 3, 4, 5, 6 or 7 C atoms and correspondingly preferably representing ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy, as well as methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonoxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

[0064] If the group R in the formula is shown in the context 1-12 ,R QR or L represents an alkyl group in which one or more CH2 groups are replaced by S, and it can be straight-chain or branched. It is preferably straight-chain, having 1, 2, 3, 4, 5, 6 or 7 C atoms and correspondingly preferably representing thiomethyl, thioethyl, thiopropyl, thiobutyl, thiopentyl, thiohexyl or thioheptyl.

[0065] Oxaalkyl preferably represents straight-chain 2-oxapropyl (=methoxymethyl), 2-oxabutyl (=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-,3- or 4-oxapentyl, 2-,3-,4- or 5-oxahexyl, 2-,3-,4-,5- or 6-oxaheptyl, 2-,3-,4-,5-,6- or 7-oxaoctyl, 2-,3-,4-,5-,6-,7- or 8-oxanonyl, 2-,3-,4-,5-,6-,7-,8- or 9-oxadecyl.

[0066] If the group R in the formula is shown in the context 1-12 R or L represents alkoxy or oxalyl, and it may also contain one or more additional oxygen atoms, provided that the oxygen atoms are not directly connected to each other.

[0067] In another preferred embodiment, R 1-12 R Q One or more of R or L selected from -S 1 -F, -OS 1 -F, -O-S1-O-S2, where S 1 C 1-12 -alkylene or C 2-12 - Idemenyl and S 2 For H, C 1-12 -alkyl or C 2-12 -Alkenyl, and very preferably selected from the following groups: -OCH2OCH3, -O(CH2)2OCH3, -O(CH2)3OCH3, -O(CH2)4OCH3, -O(CH2)2F, -O(CH2)3F, -O(CH2)4F.

[0068] If the group R in the formula is shown in the context 1-12 ,R QR or L indicates an alkyl group in which one of the CH2 groups has been replaced by -CH=CH-, and it can be straight-chain or branched. It is preferably straight-chain and has 2-10 C atoms. Accordingly, it represents, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hep-1-, -2-, -3-, -4-, -5- or -6-enyl, oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl, non-1-, -2-, -3-, -4-, -5-, -6-, -7- or -8-enyl, dec-1-, -2-, -3-, -4-, -5-, -6-, -7-, -8- or -9-enyl.

[0069] If the group R in the formula is shown in the context 1-12 ,R Q R or L represents an alkyl or alkenyl group that is at least monosubstituted with a halogen, preferably a straight chain, and the halogen is preferably F or Cl. In the case of multiple substitution, the halogen is preferably F. The resulting group also includes perfluorinated groups. In the case of monosubstituted substitution, the fluorine or chlorine substituent can be at any desired position, but is preferably at the ω-position.

[0070] The halogen is preferably F or Cl, with F being the most preferred.

[0071] Group -CR 0 =CR 00 - Preferably -CH=CH-.

[0072] -CO-, -C(=O)-, and -C(O)- represent carbonyl groups, i.e.

[0073] Preferred substituents L are, for example, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R) x )2、-C(=O)Y 1 -C(=O)R x -N(R) x 2. Straight-chain or branched alkyl, alkoxy, alkyl carbonyl, alkoxy carbonyl, alkyl carbonyloxy, or alkoxy carbonyloxy groups, each having 1-25 carbon atoms, wherein one or more H atoms may optionally be replaced by F or Cl, optionally substituted silyl groups having 1-20 Si atoms, or optionally substituted aryl groups having 6-25, preferably 6-15 carbon atoms.

[0074] Where R xRepresents H, F, Cl, CN, or a straight-chain, branched, or cyclic alkyl group having 1-25 C atoms, wherein one or more non-adjacent CH2 groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, or -O-CO-O-, such that the O- and / or S- atoms are not directly connected to each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P-, or P-Sp-.

[0075] Y 1 It represents halogens.

[0076] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, and phenyl.

[0077] Preferred

[0078] L has one of the meanings described above.

[0079] The polymerizable group P is a group suitable for polymerization reactions, such as free radical or ionic chain polymerization, addition polymerization, or condensation polymerization, or a group suitable for polymer-like reactions, such as groups that add to or condense on the polymer backbone. Groups suitable for chain polymerization are particularly preferred, especially those containing C=C double bonds or -C≡C- triple bonds, and groups suitable for ring-opening polymerization, such as oxobutane or epoxy groups.

[0080] Preferred group P is selected from the following groups

[0081] CH2=CW 1 -CO-O-、CH2=CW 1 -CO-、 CH2=CW 2 -(O) k3 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -、HS-CW 2 W3 -、HW 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 - CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si-, where W 1 It represents H, F, Cl, CN, CF3, phenyl, or alkyl groups having 1-5 carbon atoms, especially H, F, Cl, or CH3, W 2 and W 3 Each independently represents H or an alkyl group having 1-5 carbon atoms, especially H, methyl, ethyl, or n-propyl, W 4 W 5 and W 6 Each independently represents Cl, an oxaalkyl or oxacarbonylalkyl group having 1-5 carbon atoms, and W. 7 and W 8 Each of them independently represents H, Cl or an alkyl group having 1-5 C atoms, Phe represents 1,4-phenylene, which is optionally substituted with one or more groups L different from P-Sp- as defined above, k1, k2 and k3 each independently represent 0 or 1, k3 preferably represents 1, and k4 represents an integer from 1 to 10.

[0082] The preferred group P is selected from the following groups:

[0083] CH2=CW 1 -CO-O-、CH2=CW 1 -CO-、 CH2=CW 2 -O-、CH2=CW 2 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1-CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 - CH2=CH-(CO) k1 -Phe-(O) k2 - Phe-CH=CH- and W 4 W 5 W 6 Si-, where W 1 It represents H, F, Cl, CN, CF3, phenyl, or alkyl groups having 1-5 carbon atoms, especially H, F, Cl, or CH3, W 2 and W 3 Each independently represents H or an alkyl group having 1-5 carbon atoms, especially H, methyl, ethyl, or n-propyl, W 4 W 5 and W 6 Each independently represents Cl, an oxaalkyl or oxacarbonylalkyl group having 1-5 carbon atoms, and W. 7 and W 8 Each of them independently represents H, Cl or an alkyl group having 1-5 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.

[0084] The highly preferred group P is selected from the group CH2=CW. 1 -CO-O-, especially CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, as well as CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-, and

[0085] Further preferred polymerizable groups P are selected from ethylene oxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane, and epoxy groups, with acrylate and methacrylate being the most preferred.

[0086] In a highly preferred polymerizable compound, all polymerizable groups have the same meaning.

[0087] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X, so that each group P-Sp- conforms to the formula P-Sp"-X"-, wherein

[0088] "Sp" represents a linear or branched alkylene group having 1-20, preferably 1-12, carbon atoms, optionally mono- or polysubstituted with F, Cl, Br, I, or CN, wherein one or more non-adjacent CH2 groups may be independently substituted with -O-, -S-, -NH-, or -N(R) in such a manner that the O and / or S atoms are not directly connected to each other. 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- can be substituted.

[0089] X" means -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 single bonds

[0090] R 0 and R 00 Each independently represents H or an alkyl group having 1-20 carbon atoms, and

[0091] Y 2 and Y 3 Each can be represented independently as H, F, Cl, or CN.

[0092] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, or -CO-NR. 0 -、-NR 0 -CO-、-NR 0 -CO-NR 00 - or a single key.

[0093] 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 It has the meaning described above.

[0094] The particularly preferred groups Sp and -Sp"-X"- are -(CH2). p1 -、-(CH2) p1 -O-、-(CH2) p1 -O-CO-、-(CH2) p1 -CO-O-、-(CH2) p1 -O-CO-O-, where p1 and q1 have the meanings described above.

[0095] The particularly preferred group Sp" is, in each case, a straight-chain ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methyliminoethylene, 1-methylalkylene, vinylene, propenylene, and butenylene.

[0096] In a preferred embodiment of the invention, Formula I and its derivative compounds contain a spacer group Sp substituted with one or more polymerizable groups P, such that the group Sp-P corresponds to Sp(P). s , where s is ≥2 (branched polymerizable groups).

[0097] The preferred formula I compound according to this preferred embodiment is one in which s is 2, i.e., a compound containing the group Sp(P)2. The most preferred formula I compound according to this preferred embodiment contains a group selected from the following formulas:

[0098] -X-alkyl-CHPP S1

[0099] -X-alkyl-CH((CH2) aa P)((CH2)bb P) S2

[0100] -XN((CH2) aa P)((CH2) bb P) S3

[0101] -X-alkyl-CHP-CH2-CH2PS4

[0102] -X-alkyl-C(CH2P)(CH2P)-C aa H 2aa+1 S5

[0103] -X-alkyl-CHP-CH2P S6

[0104] -X-alkyl-CPP-C aa H 2aa+1 S7

[0105] -X-alkyl-CHPCHP-C aa H 2aa+1 S8

[0106] Where P is defined as in Equation I.

[0107] Alkyl refers to a straight-chain or branched alkylene group with a single bond or 1-12 carbon atoms, which is unsubstituted or mono- or polysubstituted with F, Cl, or CN, and one or more non-adjacent CH2 groups may be independently bonded to each other such that the O and / or S atoms are not directly connected to each other. 0 )=C(R 0 )-、-C≡C-、-N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- substitution, where R 0 It has the meaning described above.

[0108] aa and bb each independently represent 0, 1, 2, 3, 4, 5, or 6.

[0109] X has one of the meanings described for X", and is preferably O, CO, SO2, O-CO-, CO-O or a single bond.

[0110] The preferred spacer group Sp(P)2 is selected from formulas S1, S2 and S3.

[0111] The highly preferred spacer group Sp(P)2 is selected from the following formulas:

[0112] -CHPP S1a

[0113] -O-CHPP S1b

[0114] -CH2-CHPP S1c

[0115] -OCH2-CHPP S1d

[0116] -CH(CH2-P)(CH2-P)S2a

[0117] -OCH(CH2-P)(CH2-P)S2b

[0118] -CH2-CH(CH2-P)(CH2-P)S2c

[0119] -OCH2-CH(CH2-P)(CH2-P)S2d

[0120] -CO-NH((CH2)2P)((CH2)2P)S3a

[0121] P is preferably selected from ethylene oxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxobutane and epoxy groups, with acrylate and methacrylate being very preferred, and methacrylate being the most preferred.

[0122] Further preferably, all polymerizable groups P present in the same compound have the same meaning, and very preferably represent acrylate group or methacrylate group, most preferably methacrylate group.

[0123] Sp preferably represents a single bond or -(CH2). p1 -、-(CH2) p2 -CH = CH-(CH2) p3 -、-O-(CH2) p1 -、-O-CO-(CH2) p1 or -CO-O-(CH2) p1 Where p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently 0, 1, 2 or 3, and if Sp is -O-(CH2). p1 -、-O-CO-(CH2) p1 Or -CO-O-(CH2) p1 Then, the O-atom or CO-group is attached to the benzene ring.

[0124] Further preferably, at least one Sp group is a single bond.

[0125] Further preferably, at least one Sp group is different from a single bond, and is preferably selected from -(CH2). p1 -、-(CH2) p2 -CH = CH-(CH2) p3 -、-O-(CH2) p1-、-O-CO-(CH2) p1 or -CO-O-(CH2) p1 Where p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently 0, 1, 2 or 3, and if Sp is -O-(CH2). p1 -、-O-CO-(CH2) p1 Or -CO-O-(CH2) p1 Then, the O-atom or CO-group is attached to the benzene ring.

[0126] The Sp atom is preferably different from a single bond and is selected from -(CH2)2-, -(CH2)3-, -(CH2)4-, -O-(CH2)2-, -O-(CH2)3-, -O-CO-(CH2)2- and -CO-O-(CH)2-, wherein the O atom or CO group is attached to the benzene ring.

[0127] Preferred compounds of formula IA are selected from the group consisting of formulas IA-1 to IA-10:

[0128]

[0129]

[0130] Wherein alkyl and alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, alkenyl and alkenyl* each independently represent a straight-chain alkenyl group having 2-6 carbon atoms, alkoxy and alkoxy* each independently represent a straight-chain alkoxy group having 1-6 carbon atoms, and L 1 and L 2 Each can be represented independently as F or Cl, with F being the preferred choice.

[0131] Compounds of formula IA-6 are highly preferred.

[0132] Preferably, the LC medium contains one, two, or three compounds of formula IA or its sub-formulas.

[0133] Preferably, the total proportion of compound IA and its sub-formulas in the LC medium is >5-25%, very preferably 7-20%, and most preferably 8-15%, by weight.

[0134] Preferred compounds of formula IB are selected from the following sub-formulas:

[0135]

[0136]

[0137] Wherein alkyl and alkyl* independently represent straight-chain alkyl groups having 1-6 C atoms, preferably ethyl, n-propyl or n-butyl, and (O) represents an oxygen atom or a single bond, preferably an oxygen atom.

[0138] Compounds of formula IB-1 and IB-2 are highly preferred, and compounds of formula IB-1 are most preferred, especially those in which alkyl represents ethyl, n-propyl or n-butyl, preferably n-propyl, (O) represents an oxygen atom, and alkyl* represents ethyl, n-propyl or n-butyl, preferably those of ethyl.

[0139] Preferably, the LC medium contains 1, 2 or 3 compounds, most preferably 1 compound of formula IB or a subform thereof.

[0140] Preferably, the total proportion of compounds of formula IB and its derivatives in the LC medium is 0.5-10% by weight, very preferably 1-10% by weight. In another preferred embodiment, the total proportion of compounds of formula IB and its derivatives in the LC medium is 2-8%, very preferably 2.5-7%.

[0141] Preferred compounds of formula IC are selected from the following sub-formulas:

[0142]

[0143]

[0144] Compounds of formulas IC-1, IC-2, IC-3, IC-4, IC-5 and IC-6 are highly preferred, and compounds of formulas IC-1 and IC-4 are most preferred.

[0145] The preferred LC medium contains compounds of type 1, 2, or 3 ICs or their derivatives.

[0146] The total proportion of the preferred IC and its derivative compounds in the LC medium is 10 to 65%, very preferably 15 to 55%, and most preferably 20 to 45%, by weight.

[0147] The following are further preferred embodiments of the LC media according to the present invention, including any combination thereof:

[0148] LC media contain one or more compounds of formula II

[0149]

[0150] Each of the groups, independently of each other and in the same or different manner each time it appears, has the following meanings:

[0151] R 1 and R 2It is a straight-chain, branched, or cyclic alkyl group having 1-25 carbon atoms, wherein one or more non-adjacent CH2- groups are optionally surrounded by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -,-C≡C-, The O- and / or S- atoms are replaced in such a way that they are not directly bonded to each other, and one or more H atoms are optionally replaced by F or Cl, preferably alkyl or alkoxy groups having 1-6 C atoms.

[0152] R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms.

[0153] A 1 and A 2 Groups selected from the following formulas

[0154]

[0155]

[0156] Preferred formulas A1, A2, A3, A4, A5, A6, A9, and A10; Very preferred formulas A1, A2, A3, A4, A5, A9, and A10.

[0157] Z 1 and Z 2 The bonds are -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O-, or single bonds, preferably single bonds.

[0158] L 1 L 2 L 3 and L 4 The solvent is F, Cl, OCF3, CF3, CH3, CH2F, or CHF2, preferably F or Cl, and very preferably F.

[0159] Y is H, F, Cl, CF3, CHF2, or CH3, preferably H or CH3, and very preferably H.

[0160] L C It is CH3 or OCH3, preferably CH3.

[0161] a1 is 1 or 2.

[0162] a2 is 0 or 1.

[0163] The preferred LC medium contains one or more compounds of formula II, selected from compounds of formulas IIA, IIB, IIC, and IID.

[0164] The preferred LC medium contains one or more compounds of formula II, selected from compounds of formulas IIA, IIB, IIC, and IID.

[0165]

[0166] in

[0167] R 2A and R 2B Each of these groups independently represents H, an alkyl or alkenyl group having up to 15 carbon atoms, which is unsubstituted, monosubstituted with CN or CF3, or at least monosubstituted with a halogen, wherein one or more CH2 groups in these groups may be -O-, -S- in a manner such that the O atom is not directly attached to each other. -C≡C-, -CF₂O-, -OCF₂-, -OC-O-, or -O-CO- can be substituted.

[0168] L 1 -L 4 Each can be independently represented as F, Cl, CF3, or CHF2.

[0169] Y represents H, F, Cl, CF3, CHF2, or CH3, with H or CH3 being preferred, and H being particularly preferred.

[0170] Z 2 Z 2B and Z 2D Each of these independently represents a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, and -CH=CHCH2O-.

[0171] p represents 0, 1, or 2, and

[0172] Each occurrence of q represents either 0 or 1, either the same or different.

[0173] Preferred compounds of formulas IIA, IIB, IIC, and IID are those in which R 2B Those that represent alkyl or alkoxy groups having a maximum of 15 carbon atoms, and very preferably (O)C. v H 2v+1 , where (O) is an oxygen atom or a single bond and v is 1, 2, 3, 4, 5 or 6.

[0174] Further preferred compounds of formulas IIA, IIB, IIC, and IID are those in which R2A Or R 2B Those that represent or contain cycloalkyl or cycloalkoxy groups are preferably selected from...

[0175] Where S 1 C 1-5 -alkylene or C 2-5 - Idemenyl and S 2 For H, C 1-7 -alkyl or C 2-7 -Alkenyl, and very preferably selected from

[0176]

[0177] Further preferred compounds of formulas IIA, IIB, IIC and IID are shown below:

[0178] Further preferred compounds of formulas IIA, IIB, IIC and IID are shown below:

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189] Wherein parameter a represents 1 or 2, alkyl and alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, alkenyl represents a straight-chain alkenyl group having 2-6 carbon atoms, and (O) represents an oxygen atom or a single bond. alkenyl preferably represents CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH-, or CH3-CH=CH-(CH2)2-.

[0190] Particularly preferred LC media according to the invention comprise one or more compounds of the formulas IIA-2, IIA-8, IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1, and IID-4.

[0191] The proportion of compounds of formula IIA and / or IIB in the mixture as a whole is preferably at least 20 wt%.

[0192] In another preferred embodiment, the LC medium comprises one or more compounds of formula III.

[0193]

[0194] in

[0195] R 11 and R 12 Each of these groups independently represents H, an alkyl or alkoxy group having 1-15 carbon atoms, wherein one or more CH2 groups among these groups can be represented independently such that the O atom is not directly connected to each other. -C≡C-, -CF₂O-, -OCF₂-, -CH=CH-, are replaced by -O-, -CO-O-, or -O-CO-, and in which, one or more H atoms can be replaced by halogens.

[0196] A 3 Each occurrence represents an independent representation.

[0197] a) 1,4-cyclohexeneyl or 1,4-cyclohexeneyl, wherein one or both non-adjacent CH2 groups may be replaced by -O- or -S-.

[0198] b) 1,4-Phenylidene, wherein one or both CH groups may be replaced by N, or

[0199] c) A group selected from spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octyl, 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.

[0200] Groups a), b), and c) can be mono- or poly-substituted with halogen atoms.

[0201] n represents 0, 1, or 2, preferably 0 or 1.

[0202] Z 1Each occurrence independently represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C-, or a single bond, and

[0203] L 11 and L 12 Each of these elements independently represents F, Cl, CF3, or CHF2, preferably H or F, with F being the most preferred.

[0204] W represents O or S, and if n is 0, then W is not S.

[0205] In a preferred embodiment of the invention, the LC medium comprises one or more compounds of formula III-1.

[0206]

[0207] The groups appearing therein have the same meaning as given in Formula III above and are preferably...

[0208] R 11 and R 12 Each of the alkyl, alkenyl, or alkoxy groups having a maximum of 15 carbon atoms, more preferably one or both of them, represents an alkoxy group and...

[0209] L 11 and L 12 Each is preferred, represented by F.

[0210] In another preferred embodiment, the LC medium comprises one or more compounds of formula III-1 selected from compounds of formula III-1-1 to III-1-11, preferably formula III-1-6.

[0211]

[0212]

[0213] Wherein alkyl and alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, alkenyl and alkenyl* each independently represent a straight-chain alkenyl group having 2-6 carbon atoms, alkoxy and alkoxy* each independently represent a straight-chain alkoxy group having 1-6 carbon atoms, and L 11 and L 12 Each can be represented independently as F or Cl, with F being the preferred choice.

[0214] In another preferred embodiment of the invention, the LC medium comprises one or more compounds of formula III2-1 and / or III2-2.

[0215]

[0216] Where L 11 and L 12 Having the same meaning as given in Equation III, (O) represents O or a single bond.

[0217] R IIIA This refers to an alkyl or alkenyl group, or a Cy-C group, having a maximum of 7 carbon atoms. m H 2m+1 -,

[0218] m and n are the same or different from 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, and

[0219] Cy represents an alicyclic group having 3, 4, or 5 ring atoms, which may be optionally alkyl or alkenyl groups having a maximum of 3 C atoms, or substituted with halogen or CN, and preferably represents cyclopropyl, cyclobutyl, or cyclopentyl.

[0220] Compounds of formula III2-1 and / or III2-2 may be used to replace compounds of formula III or may be additionally contained in the LC medium, preferably additionally.

[0221] The most preferred compounds of formula III2-1 and III2-2 are as follows:

[0222]

[0223] Here, alkoxy represents a straight-chain alkoxy group having 1-6 carbon atoms.

[0224] In another preferred embodiment of the invention, the LC medium comprises one or more compounds of formula III-3 to III-5, preferably formula III-4.

[0225]

[0226] The parameters have the meanings given above, R 11 Preferably, it represents straight-chain alkyl and R 12 Preferably, alkoxy groups are represented, each having 1 to 7 carbon atoms.

[0227] In another preferred embodiment, the LC medium comprises one or more compounds of formula I, selected from compounds of formulas III-6 to III-8, preferably formula III-7.

[0228]

[0229] The parameters have the meanings given above, R 11 Preferably, it represents straight-chain alkyl and R 12 Preferably, alkoxy groups are represented, each having 1 to 7 carbon atoms.

[0230] In another preferred embodiment of the invention, the LC medium comprises one or more compounds of formula III-9.

[0231]

[0232] The parameters have the meanings given above, R 11 Preferably, it represents straight-chain alkyl and R 12 Preferably, alkoxy groups are represented, each having 1 to 7 carbon atoms.

[0233] Preferred compounds of formula III-9 are selected from formulas III-9-1 to III-9-10:

[0234]

[0235]

[0236] Where R 12 The alkyl group having 1 to 7 carbon atoms is preferred to be ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl.

[0237] Preferred compounds of formula III-9 are selected from formulas III-9-1, III-9-2, III-9-3, III-9-4, and III-9-5, very preferred formulas III-9-2 and III-9-3, most preferred formula III-9-2, and all of the aforementioned formulas R. 12 Ethyl, n-propyl or n-butyl are preferred, with n-butyl being very preferred.

[0238] In a preferred embodiment, the medium comprises one or more compounds of formula IV.

[0239]

[0240] in

[0241] R 41 This indicates an unsubstituted alkyl group having 1-7 carbon atoms or an unsubstituted alkenyl group having 2-7 carbon atoms, preferably an n-alkyl group, and particularly preferably having 2, 3, 4 or 5 carbon atoms.

[0242] R 42The term refers to an unsubstituted alkyl group having 1-7 carbon atoms or an unsubstituted alkoxy group having 1-6 carbon atoms (preferably having 2-5 carbon atoms), an unsubstituted alkenyl group having 2-7 carbon atoms, preferably having 2, 3 or 4 carbon atoms, more preferably vinyl or 1-propenyl and especially vinyl.

[0243] These compounds are different from those in formula IC.

[0244] The compounds of formula IV are preferably selected from compounds of formulas IV-1 to IV-4.

[0245]

[0246] in

[0247] alkyl and alkyl', independently of each other, represent alkyl groups having 1 to 7 carbon atoms, preferably having 2 to 5 carbon atoms.

[0248] alkenyl indicates an alkenyl group having 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms, and particularly preferably 2 carbon atoms.

[0249] 'alkenyl' represents an alkenyl group having 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms, particularly preferably 2 to 3 carbon atoms, and

[0250] alkoxy means an alkoxy group having 1 to 5 carbon atoms, preferably having 2 to 4 carbon atoms.

[0251] Preferably, the LC medium comprises one or more compounds selected from formulas IV-1-1 to IV-1-4.

[0252]

[0253] Very preferably, the LC medium according to the invention comprises one or more compounds of formula IV-2-1 and / or IV-2-2.

[0254]

[0255] Very preferably, the LC medium according to the invention comprises a compound of formula IV-3, particularly compounds selected from formulas IV-3-1 and IV-3-2.

[0256]

[0257] LC media preferably additionally contain one or more compounds of formula IVa.

[0258]

[0259] in

[0260] R 41 and R 42 Each of these independently represents a straight-chain alkyl, alkoxy, alkenyl, alkoxyalkyl, or alkoxy group having a maximum of 12 carbon atoms.

[0261] express

[0262] Z 4 Representing single bonds: -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -

[0263] OCH2-, -COO-, -OCO-, -C2F4-, -C4H8- or -CF=CF-.

[0264] Preferred compounds of formula IVa are shown below:

[0265]

[0266] Wherein alkyl and alkyl* each independently represent straight-chain alkyl groups having 1-6 carbon atoms.

[0267] The LC medium of the present invention preferably contains at least one compound of formula IVa-1 and / or formula IVa-2.

[0268] The proportion of the IVa compound in the mixture as a whole is preferably at least 5 wt%.

[0269] Preferably, the LC medium comprises one or more compounds of formula IVb-1 to IVb-3.

[0270]

[0271] in

[0272] alkyl and alkyl* each independently represent straight-chain alkyl groups having 1-6 carbon atoms, and

[0273] alkenyl and alkenyl* each independently represent straight-chain alkenyl groups having 2-6 carbon atoms.

[0274] The proportion of biphenyls of formula IV-1 to IV-3 in the mixture as a whole is preferably at least 3 wt%, and particularly ≥5 wt%.

[0275] Of the compounds of formulas IVb-1 to IVb-3, compound IVb-2 is particularly preferred.

[0276] The preferred biphenyl is

[0277]

[0278] Wherein alkyl* represents an alkyl group having 1-6 carbon atoms, and preferably represents n-propyl.

[0279] The LC media of the present invention particularly preferably contain one or more compounds of the formula IVb-1-1 and / or IVb-2-3.

[0280] In a preferred embodiment, the LC medium comprises one or more compounds of formula V.

[0281]

[0282] in

[0283] R 51 and R 52 They are independent of each other for R 41 and R 42 The term "alkyl" is given in one of the following meanings and is preferably interpreted as having 1-7 carbon atoms, preferably n-alkyl, particularly preferably n-alkyl having 1-5 carbon atoms; alkoxy having 1-7 carbon atoms, preferably n-alkoxy, particularly preferably n-alkoxy having 2-5 carbon atoms; or alkoxyalkyl, alkenyl, or alkenyloxy having 2-7 carbon atoms, preferably having 2-4 carbon atoms, preferably alkenyloxy.

[0284] Same or different

[0285]

[0286] in

[0287] Preferred representation

[0288] Z 51 Z 52 Each of these independently represents -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or a single bond, preferably -CH2-CH2-, -CH2-O-, or a single bond, and particularly preferably a single bond.

[0289] n is 1 or 2.

[0290] The compounds of formula V are preferably selected from compounds of formulas V-1 to V-16:

[0291]

[0292]

[0293] Where R 1 and R2 Having the above for R 51 The meaning stated.

[0294] R 1 and R 2 Preferably, each of the two groups is independently represented as a straight-chain alkyl group having 1 to 6 carbon atoms or a straight-chain alkenyl group having 2 to 7 carbon atoms.

[0295] Preferred LC media comprise one or more compounds of formulas V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15 and / or V-16.

[0296] The LC media according to the invention particularly preferably contain compounds of formula V-10, V-12, V-16 and / or IV-1, especially in amounts of 5-30%.

[0297] The preferred compound of formula V-10 is shown below:

[0298]

[0299]

[0300] The LC medium of the present invention particularly preferably comprises a combination of a tricyclic compound of formula V-10a and / or formula V-10b and one or more bicyclic compounds of formula IV-1. The total proportion of the combination of the compound of formula V-10a and / or V-10b and one or more compounds selected from the dicyclohexyl compound of formula IV-1 is 5-40%, very particularly preferably 15-35%.

[0301] The most particularly preferred LC media contain compounds V-10a and CC-2-3.

[0302]

[0303] Compounds V-10a and IV-1-1 are preferably present in the mixture at a concentration of 15-35%, particularly preferably 15-25% and especially preferably 18-22%, based on the mixture as a whole.

[0304] The most particularly preferred LC media contain compounds V-10b and IV-1-1:

[0305]

[0306] Compounds V-10b and IV-1-1 are preferably present in the mixture at a concentration of 15-35%, particularly preferably 15-25% and especially preferably 18-22%, based on the mixture as a whole.

[0307] The most particularly preferred LC media contain the following three compounds

[0308]

[0309] Compounds V-10a, V-10b and IV-1-1 are preferably present in the mixture at a concentration of 15-35%, particularly preferably 15-25% and especially preferably 18-22%, based on the mixture as a whole.

[0310] Preferred LC media contain at least one compound selected from the following compounds

[0311]

[0312] Where R 41 and R 42 and R 51 and R 52 It has the meaning described above. Preferably, in compounds V-6, V-7, and IV-1, R 41 and R 51 This indicates an alkyl or alkenyl group having 1-6 carbon atoms or 2-6 carbon atoms, and R 42 and R 52 This indicates an alkenyl group having 2-6 carbon atoms.

[0313] Preferred LC media comprise at least one compound of formula V-6a, V-6b, V-7a, V-7b, IV-4-1, IV-4-2, IV-3a, and IV-3b:

[0314]

[0315]

[0316] Where alkyl represents an alkyl group having 1-6 carbon atoms and alkenyl represents an alkenyl group having 2-6 carbon atoms.

[0317] Compounds of formulas V-6a, V-6b, V-7a, V-7b, IV-4-1 and IV-4-2 are preferably present in the LC medium of the present invention in an amount of 1-40 wt%, preferably 5-35 wt%, and very particularly preferably 10-30 wt%.

[0318] In a preferred embodiment of the invention, the LC medium additionally comprises one or more compounds of formulas VI-1 to VI-9.

[0319]

[0320]

[0321] in

[0322] R7 Each has its own independent property regarding R in Equation IIA 2A One of the meanings, and

[0323] w and x each represent 1-6 independently.

[0324] Particularly preferred are LC media containing at least one compound of formula V-9.

[0325] In a preferred embodiment of the invention, the LC medium additionally comprises one or more compounds of formulas VII-1 to VII-25.

[0326]

[0327]

[0328]

[0329]

[0330]

[0331] in

[0332] R represents a straight-chain alkyl or alkoxy group with 1-6 carbon atoms, (O) represents -O- or a single bond, X represents F, Cl, OCF3 or OCHF2, and L represents... x It represents H or F, where m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4.

[0333] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, or pentoxy.

[0334] X preferably represents F or OCH3, with F being the most preferred.

[0335] The LC medium of the present invention preferably contains terphenyl of formulas VII-1 to VII-25 in an amount of 2-30 wt%, particularly 5-20 wt%.

[0336] Particularly preferred are compounds of formulas VII-1, VII-2, VII-4, VII-20, VII-21, and VII-22, wherein X represents F. In these compounds, R preferably represents an alkyl group and an alkoxy group, each having 1-5 carbon atoms. In compound VII-20, R preferably represents an alkyl or alkenyl group, particularly an alkyl group. In compound VII-21, R preferably represents an alkyl group. In compounds VII-22 to VII-25, X preferably represents F.

[0337] If the Δn value of the mixture is ≥0.1, then terphenyl compounds of formulas VII-1 to VII-25 are preferably used in the LC medium of the present invention. The preferred LC medium contains 2-20 wt% of one or more terphenyl compounds selected from formulas VII-1 to VII-25.

[0338] Further preferred implementation schemes are listed below:

[0339] a) An LC medium comprising at least one compound of formula Z-1 to Z-7,

[0340]

[0341] R, (O) and alkyl have the meanings described above for Formula III.

[0342] b) Preferably, the LC medium of the present invention comprises one or more substances containing a tetrahydronaphthyl or naphthyl unit, such as compounds of formula N-1 to N-5.

[0343]

[0344] Where R 1N and R 2N Each independently possesses the above-mentioned characteristics for R. 2A The meaning of the above preferably refers to a straight-chain alkyl, a straight-chain alkoxy, or a straight-chain alkenyl group, and

[0345] Z 1 and Z 2 Each of these can be represented independently as -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2-, or a single bond.

[0346] c) Preferred LC media comprise one or more compounds selected from those of formula BC difluorodibenzo-p-chloro, formula CR chloro, and formulas PH-1 and PH-2 fluorophenanthrene compounds.

[0347]

[0348]

[0349] in

[0350] R B1 ,R B2 ,R CR1 ,R CR2 ,R1 ,R 2 Each has its own R independently 2A Meaning. c can be 0, 1, or 2. R 1 and R 2 Preferably, alkyl or alkoxy groups having 1-6 carbon atoms are represented independently of each other.

[0351] The LC medium of the present invention preferably contains compounds of formula BC, CR, PH-1, and PH-2 in an amount of 3-20 wt%, particularly in an amount of 3-15 wt%.

[0352] Particularly preferred compounds of formulas BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.

[0353]

[0354]

[0355] in

[0356] alkyl and alkyl* each independently represent straight-chain alkyl groups having 1-6 carbon atoms, and

[0357] alkenyl and

[0358] each alkenyl* represents a straight-chain alkenyl group having 2-6 carbon atoms, and each alkenyl* represents a straight-chain alkenyl group.

[0359] It is particularly preferred that the LC medium contains one, two or three compounds of the form BC-2, BF-1 and / or BF-2.

[0360] d) Preferred LC media contain one or more Ininium compounds.

[0361]

[0362] in

[0363] R 11 ,R 12 ,

[0364] R 13 Each of these terms independently represents a straight-chain alkyl, alkoxy, alkoxyalkyl, or alkenyl group having 1-6 carbon atoms.

[0365] R 12 and R 13 Additional indication of halogen, preferably F,

[0366] express

[0367]

[0368] i represents 0, 1, or 2.

[0369] Preferred In compounds are those of formulas In-1 to In-16 as described below:

[0370]

[0371]

[0372]

[0373] Compounds of formulas In-1, In-2, In-3 and In-4 are particularly preferred.

[0374] Compounds of formula In and sub-formulas In-1 to In-16 are preferably used in the LC media of the present invention at a concentration of ≥5 wt%, particularly 5-30 wt% and very particularly preferably 5-25 wt%.

[0375] e) Preferred LC media additionally contain one or more compounds of formula L-1 to L-5.

[0376]

[0377] in

[0378] R and R 1 Each of them independently possesses the above-mentioned characteristics for R in Equation IIA. 2A The meanings are as follows: alkyl indicates an alkyl group having 1-6 carbon atoms. The parameter s indicates 1 or 2.

[0379] Compounds of formulas L-1 to L-5 are preferably used at a concentration of 5-50 wt%, particularly 5-40 wt%, and very particularly preferably 10-40 wt%.

[0380] f) The preferred LC medium further comprises one or more compounds of formula IIA-Y.

[0381]

[0382] Where R 11 and R 12 Having the above for R in Equation IIA 2A One of the given meanings, and L 1 and L 2 F or Cl can be represented in the same or different ways.

[0383] Preferred compounds of formula IIA-Y are selected from the following sub-formulas.

[0384]

[0385]

[0386] Wherein, Alkyl and Alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, Alkoxy represents a straight-chain alkoxy group having 1-6 carbon atoms, Alkenyl and Alkenyl* each independently represent a straight-chain alkenyl group having 2-6 carbon atoms, and O represents an oxygen atom or a single bond. Alkenyl and Alkenyl* preferably represent CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH-, or CH3-CH=CH-(CH2)2-.

[0387] The particularly preferred compounds of formula IIA-Y are selected from the following sub-formulas:

[0388]

[0389] Alkoxy and Alkoxy* have the meanings defined above and preferably represent methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentoxy.

[0390] g) An LC medium additionally comprising one or more compounds selected from the following tetraphenyl compounds:

[0391]

[0392] in

[0393] R Q It is an alkyl, alkoxy, oxalyl, or alkoxyalkyl group having 1-9 carbon atoms, or an alkenyl or alkenoxy group having 2-9 carbon atoms, all of which may optionally be fluorinated.

[0394] X Q It is F, Cl, a haloalkyl or alkoxy group having 1-6 carbon atoms, or a haloalkenyl or alkenoxy group having 2-6 carbon atoms.

[0395] L Q1 -L Q6 Each is independently H or F, where L Q1 -L Q6 At least one of them is F.

[0396] The preferred compound of formula Q is wherein R Q Those that represent straight-chain alkyl groups having 2-6 C- atoms are very preferred, with ethyl, n-propyl or n-butyl being the most preferred.

[0397] The preferred compound of formula Q is wherein L Q3 and L Q4Those that are F. A further preferred formula Q compound is one in which L... Q3 L Q4 and L Q1 and L Q2 One or two of them are F.

[0398] The preferred compound of formula Q is wherein X Q For those representing F or OCF3, F is highly preferred.

[0399] Compound Q is preferably selected from the following sub-formulas.

[0400]

[0401] Where R Q It has one of the meanings of formula Q or one of its preferred meanings given in the context, and preferably ethyl, n-propyl or n-butyl.

[0402] The preferred compound is of formula Q1, especially R. Q Those that are n-propyl.

[0403] Preferably, the proportion of compound Q in the LC main mixture is >0 to ≤5 wt%, very preferably 0.05-2 wt%, more preferably 0.1-1 wt%, and most preferably 0.1-0.8 wt%.

[0404] The preferred LC medium contains 1-5 compounds, preferably 1 or 2 compounds of formula Q.

[0405] Adding a Q-type tetraphenyl compound to the LC host mixture can reduce ODF inhomogeneity while maintaining high UV absorption, enabling rapid and complete polymerization, producing a strong and fast tilt angle, and improving the UV stability of the LC medium.

[0406] Furthermore, adding a Q-type compound with positive dielectric anisotropy to an LC dielectric with negative dielectric anisotropy allows for better control of the dielectric constant ε. || and ε ⊥ The value of ε can be achieved, especially high dielectric constant ε. || The value of is adjusted, and the dielectric anisotropy Δε is kept constant, thereby reducing the recoil voltage and reducing image stickiness.

[0407] The LC medium according to the present invention preferably comprises

[0408] - One or more compounds of formula IA or its derivatives, preferably formula IA-6, preferably in the concentration range of >5 to 25%, very preferably 6 to 20%, and most preferably 7 to 15%;

[0409] - One or more compounds of formula IB or its sub-formulas, preferably IB-1 or IB-2, most preferably IB-1, with a preferred concentration range of 0.5 to 5%, and very preferably 0.5 to 2%;

[0410] - A compound of one or more of the formula IC or its sub-formulas, preferably of the formula IC-1, IC-2, IC-3, IC-4, IC-5 or IC-6, very preferably of the formula IC-1 and / or IC-4, preferably with a concentration range of 10 to 70%, very preferably 15 to 55%, and most preferably 20 to 45%;

[0411] - One or more compounds of formula IC-1, in a concentration range of 20 to 70%, very preferably 25 to 65%, and most preferably 27 to 60%;

[0412] and / or

[0413] - One or more compounds of formulas IIA and IIB, preferably with a total concentration ranging from 30% to 45%;

[0414] and / or

[0415] - One or more compounds of formula IV, preferably with a total concentration ranging from 2% to 30%, more preferably from 5% to 25%, and particularly preferably from 5% to 15%;

[0416] and / or

[0417] - One or more compounds of formula V-16, wherein R is preferred. 1 and R 2 Selected from ethyl and propyl, preferably with a total concentration ranging from 2% to 30%, more preferably from 5% to 25%, and particularly preferably from 5% to 15%.

[0418] Specifically, the medium contains

[0419] - One or more compounds CY-n-Om, particularly CY-3-O4, CY-5-O4 and / or CY-3-O2, preferably in a total concentration range of 5% to 30%, more preferably 10% to 20%;

[0420] - One or more compounds PY-n-Om, particularly PY-1-O2, PY-2-O2 and / or PY-3-O2, preferably in a total concentration range of 5% to 40%, more preferably 10% to 30%;

[0421] and / or

[0422] -CPY-n-Om, particularly CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably at a concentration >5%, particularly 7% to 20%, based on the entire mixture.

[0423] and / or

[0424] - 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 >3%, particularly 5 to 15%, based on the entire mixture;

[0425] and / or

[0426] -CPY-n-Om and CY-n-Om, preferably at a concentration of 10 to 80%, based on the entire mixture, and / or

[0427] -CPY-n-Om and PY-n-Om, preferably CPY-2-O2 and / or CPY-3-O2 and PY-3-O2 or PY-1-O2, preferably at a concentration of 5 to 20%, more preferably 10 to 15%, based on the entire mixture.

[0428] The present invention further relates to an active matrix addressing electro-optic display, characterized in that it contains a liquid crystal medium as claimed in claim 1 as a dielectric, and wherein 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-positive-VA, PS-TN, polymer-stabilized SA-VA, or polymer-stabilized SA-FFS display.

[0429] Advantageous for the liquid crystal medium of the present invention is a nematic phase having a temperature of ≤-20°C to ≥70°C, particularly preferably ≤-30°C to ≥80°C, and very particularly preferably ≤-40°C to ≥90°C.

[0430] The medium of the present invention has a clearing temperature of 70°C or higher, preferably 74°C or higher.

[0431] The phrase "possessing a nematic phase" here means, on the one hand, that no smectic phase or crystallization was observed at the corresponding temperature at low temperatures, and on the other hand, that the nematic phase did not become clear upon heating. Low-temperature studies were conducted in a flow viscometer at the corresponding temperature and verified by storage for at least 100 hours in a test chamber with a layer thickness corresponding to the electro-optic application. If the storage stability in the corresponding test chamber at -20°C is 1000 hours or more, the medium is said to be stable at that temperature. The response times were 500 hours and 250 hours at -30°C and -40°C, respectively. At high temperatures, the clearing point was measured in a capillary using conventional methods.

[0432] The liquid crystal mixture preferably has a nematic phase range of at least 60K and a maximum thickness of 30mm at 20°C. 2 ·s -1 Flow viscosity ν20 .

[0433] The mixture is nematic at -20°C or lower, preferably -30°C or lower, and very preferably -40°C or lower.

[0434] The birefringence Δn value in the liquid crystal mixture is typically 0.07-0.16, preferably 0.08-0.15, and most preferably 0.09-0.14.

[0435] In a preferred embodiment of the invention, the birefringence of the medium is 0.090-0.110, preferably 0.095-0.105, and particularly 0.100-0.105.

[0436] In another preferred embodiment, the medium of the present invention has a birefringence of 0.120 or higher, preferably 0.125-0.145, more preferably 0.130-0.140.

[0437] The liquid crystal mixture of the present invention has a dielectric anisotropy Δε of -1.5 to -8.0, preferably -2.0 to -4.0, and particularly -2.5 to -3.5.

[0438] The rotational viscosity γ1 at 20°C is preferably ≤120 mPa·s, and especially ≤100 mPa·s.

[0439] In a preferred embodiment, the rotational viscosity γ1 at 20°C is ≤100 mPa·s, particularly ≤95 mPa·s.

[0440] The liquid crystal media of the present invention have relatively low threshold voltage (V0) values. They are preferably 1.7V-3.0V, particularly preferably ≤2.7V, and very particularly preferably ≤2.5V.

[0441] For the purposes of this invention, unless otherwise explicitly stated, the term “threshold voltage” refers to the capacitive threshold (V0), also known as the Freedericks threshold.

[0442] Furthermore, the liquid crystal medium according to the present invention has a high voltage retention rate in the liquid crystal cell.

[0443] Typically, liquid crystal media with low addressing voltage or threshold voltage exhibit lower voltage retention than those with higher addressing voltage or threshold voltage, and vice versa.

[0444] For the purposes of this invention, the term "dielectrically positive compound" refers to a compound having Δε > 1.5, the term "dielectrically neutral compound" refers to those having -1.5 ≤ Δε ≤ 1.5, and the term "dielectrically negative compound" refers to those having Δε < -1.5. Here, the dielectric anisotropy of the compound is determined by dissolving 10% of the compound in a liquid crystal body in at least one test cell and measuring the capacitance of the resulting mixture. In each case, the test cell has a layer thickness of 20 μm and has vertical and surface alignment at 1 kHz. The measurement voltage is typically 0.5 V–1.0 V, but is always below the capacitance threshold of each liquid crystal mixture studied.

[0445] All temperature values ​​described in this invention are in °C.

[0446] The LC dielectrics of this invention are suitable for all VA-TFT (vertically aligned thin-film transistor) applications, such as VAN (vertically aligned nematic), MVA (multi-domain VA), (S)-PVA (super-patterned VA), ASV (advanced super-view or axisymmetric VA), PSA (polymer-stabilized VA), and PS-VA (polymer-stabilized VA). Furthermore, they are also suitable for IPS (in-plane switching) and FFS (edge-field switching) applications with negative Δε.

[0447] The nematic LC medium in the display of the present invention typically comprises two components, A and B, which are themselves composed of one or more separate compounds.

[0448] Component A exhibits significant negative dielectric anisotropy, and makes the dielectric anisotropy of the nematic phase ≤-0.5. In addition to one or more compounds of formula I, it preferably comprises compounds of formula IIA, IIB, and / or IIC, and one or more compounds of formula IV-1.

[0449] The proportion of component A is preferably 45-100%, particularly 60-85%.

[0450] For component A, it is preferable to select one or more individual compounds with a Δε value of ≤-0.8. The smaller the proportion of A in the mixture as a whole, the more negative this value will be.

[0451] Component B exhibits significant nematogeneity, and its flow viscosity at 20°C is no greater than 30 mm. 2 ·s -1 Preferably no larger than 25mm 2 ·s -1 .

[0452] Many suitable materials are known to those skilled in the art from the literature. Compounds of formula O-17 are particularly preferred.

[0453] A particularly preferred single compound in component B is a nematic liquid crystal with extremely low viscosity, having a flow viscosity of no more than 18 mm at 20°C. 2 ·s -1 Preferably no larger than 12mm 2 ·s -1 .

[0454] Component B is a monotropically or enantiotropically nematic, lacks a smectic phase, and can prevent the formation of a smectic phase in the LC medium at very low temperatures. For example, if various highly nematic materials are added to a smectic liquid crystal mixture, the nematic states of these materials can be compared by suppressing the degree to which a smectic phase is formed.

[0455] The mixture may also optionally contain component C, which comprises a compound having a dielectric anisotropy of Δε ≥ 1.5. These so-called positive compounds are typically present in the mixture of negative dielectric anisotropy in an amount of ≤ 20 wt%, based on the mixture as a whole.

[0456] In addition to one or more compounds of formula IA, IB and IC, the medium preferably contains 4 to 15, particularly 5 to 12, and especially preferably <10 compounds of formula IIA, IIB and / or IIC and optionally one or more compounds of formula IV-1.

[0457] In addition to compounds of formulas IA, IB and IC and formulas IIA, IIB and / or IIC and optional IV-1, other components may also be present in an amount of up to 45% of the mixture as a whole, but preferably up to 35%, and particularly up to 10%.

[0458] Other components are preferably selected from nematogenic substances, particularly from known substances of the following categories: azobenzene, benzenemethylaniline, biphenyl, terphenyl, phenyl benzoate or cyclohexyl benzoate, phenyl cyclohexanecarboxylate or cyclohexanecarboxylate, phenylcyclohexane, cyclohexylbiphenyl, cyclohexylcyclohexane, cyclohexylnaphthalene, 1,4-bicyclohexylbiphenyl or cyclohexylpyrimidine, phenyl dioxane or cyclohexyldioxane, optionally halogenated. Benzyl phenyl ether, diphenylacetylene and substituted cinnamic esters.

[0459] The most important compounds suitable as components of this type of liquid crystal phase can be characterized by the following formula IV.

[0460] R 20 -LGER 21 IV

[0461] Where L and E each refer to a carbocyclic or heterocyclic system derived from the following groups: 1,4-disubstituted benzene rings and cyclohexane rings, 4,4'-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, dihydronaphthalene and tetrahydronaphthalene, quinazoline and tetrahydroquinazoline.

[0462] G represents -CH=CH--N(O)=N-

[0463] -CH=CQ--CH=N(O)-

[0464] -C≡C--CH2-CH2-

[0465] -CO-O--CH2-O-

[0466] -CO-S--CH2-S-

[0467] -CH=N--COO-Phe-COO-

[0468] -CF2O--CF=CF-

[0469] -OCF2- -OCH2-

[0470] -(CH2)4- -(CH2)3O-

[0471] Or a CC single bond, Q refers to halogen, preferably chlorine or -CN, and R 20 and R 21 Each refers to an alkyl, alkenyl, alkoxy, alkoxyalkyl or alkoxycarbonyl group having up to 18, preferably up to 8, carbon atoms, or one of these groups refers to CN, NC, NO2, NCS, CF3, SF5, OCF3, F, Cl or Br.

[0472] In most of these compounds, R 20 and R 21 These substances differ from one another; one of these groups is typically alkyl or alkoxy. Other variations of the proposed substituents are also common. Many such substances, or mixtures thereof, are commercially available. All of these substances can be prepared by methods known from the literature.

[0473] It will be self-evident to those skilled in the art that the VA, IPS or FFS mixtures according to the present invention may also contain compounds in which, for example, H, N, O, Cl and F are substituted with corresponding isotopes.

[0474] The combination of the compounds of the preferred embodiments mentioned above with the aforementioned polymeric compounds results in a low threshold voltage, low rotational viscosity, and very good low-temperature stability in the LC medium of the present invention, while maintaining high-definition bright spots and high HR values, and allowing for the rapid establishment of particularly low tilt angles (i.e., large tilt angles) in PSA displays. In particular, compared with LC media from the prior art, this LC medium exhibits a significantly shorter response time in PSA displays, especially grayscale response time.

[0475] Preferably, the proportion of polymerizable component A) in the LC medium is >0 to <5%, very preferably >0 to ≤1%, and most preferably 0.01 to 0.5%.

[0476] Preferably, the proportion of LC component B in the LC medium is 95% to <100%, and most preferably 99% to <100%.

[0477] For use in PSA displays, the total proportion of polymerizable compounds is preferably 0.01 to 2.0%, very preferably 0.1 to 1.0%, and most preferably 0.2 to 0.8%.

[0478] For use in SA-VA displays, the total proportion of polymerizable compounds in the LC medium is preferably >0 to <3%, very preferably >0 to <2%, more preferably 0.05 to 2.0%, and most preferably 0.05 to 1.0%.

[0479] Polymerizable compounds can be prepared by methods similar to those known to those skilled in the art and described in standard organic chemistry works, such as those in Houben-Weyl, Methodden der Organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, and Stuttgart.

[0480] For example, acrylates or methacrylates can be prepared by esterification of the corresponding alcohol with an acid derivative, such as (meth)acryloyl chloride or (meth)acrylic anhydride, in the presence of a base such as pyridine or triethylamine and 4-(N,N-dimethylamino)pyridine (DMAP). Alternatively, the ester can be prepared by esterification of the alcohol with (meth)acrylic acid in the presence of a dehydrating agent, such as dicyclohexylcarbodiimide (DCC), N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC), or N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride according to Steglich, and DMAP.

[0481] The present invention also relates to LC media or LC displays as described above, wherein polymerizable compounds of formulas I1, I2 and optionally I3 are present in polymeric form.

[0482] The LC display is preferably a PS-VA, PS-IPS, PS-FFS, or SA-VA display.

[0483] In order to produce PSA or polymer-stabilized SA displays, polymerizable compounds contained in the LC medium are polymerized in situ in the LC medium between the LC display substrates, preferably with voltage applied to the electrodes simultaneously.

[0484] As described in the prior art cited at the outset, the structure of the display of the present invention corresponds to the typical geometry of a PSA display. Preferred geometries are those without protrusions, particularly those where the electrodes on the color filter side are unstructured and only the electrodes on the TFT side have slots. For example, a particularly suitable and preferred electrode structure for a PS-VA display is described in US2006 / 0066793A1.

[0485] The preferred PSA-type LC display of the present invention includes:

[0486] - A first substrate, comprising a pixel electrode defining a pixel region, the pixel electrode being connected to a switching element disposed in each pixel region and optionally including a microslit pattern, and an optional first alignment layer disposed on the pixel electrode.

[0487] - A second substrate, comprising a common electrode layer disposed on the entire portion of the second substrate facing the first substrate, and an optional second alignment layer.

[0488] - An LC layer disposed between a first substrate and a second substrate and including an LC medium as described in the context, wherein the polymerizable compound may also be present in a polymerizable form.

[0489] The first and / or second alignment layers control the alignment orientation of the LC molecules in the LC layer. For example, in a PS-VA display, the alignment layers are selected to impart vertical (or perpendicular) alignment (i.e., perpendicular to the surface) or tilted alignment to the LC molecules. Such alignment layers may, for example, contain polyimide, which may also be rubbed or prepared by photoalignment methods.

[0490] An LC layer with an LC dielectric can be deposited between the substrates of a display using methods commonly used by display manufacturers, such as the so-called one-drop-filling (ODF) method. The polymerizable components of the LC dielectric are then polymerized, for example, by UV photopolymerization. Polymerization can be performed in one step or in two or more steps.

[0491] A PSA display may include other components such as color filters, black matrices, passivation layers, optical delay layers, transistor elements for addressing individual pixels, etc., which are well known to those skilled in the art and can be used without inventive skills.

[0492] Electrode structures can be designed by engineers based on the specific display type. For example, for PS-VA displays, multi-domain orientation of LC molecules can be induced by providing electrodes with slits and / or protrusions or bumps to produce two, four, or more distinct tilt alignment directions.

[0493] Following polymerization, the polymerizable compound forms a copolymer, resulting in LC molecules in the LC medium having a certain tilt angle. Without being bound by specific theories, it is believed that at least a portion of the crosslinked polymer formed by the polymerizable compound will separate from or precipitate from the LC medium phase and form a polymer layer on the substrate or electrode, or an alignment layer thereon. Microscopic measurements (such as SEM and AFM) have confirmed that at least a portion of the formed polymer accumulates at the LC / substrate interface.

[0494] Polymerization can be carried out in one step. Alternatively, polymerization may be performed first in a first step to create a tilt angle, optionally with voltage applied simultaneously, followed by polymerization or crosslinking of the unreacted compound from the first step in a second polymerization step without voltage applied (“final curing”).

[0495] Suitable and preferred polymerization methods include, for example, thermal polymerization or photopolymerization, with photopolymerization being preferred, especially UV-induced photopolymerization, which can be achieved by exposing the polymerizable compound to UV irradiation.

[0496] Polymerizable compounds are preferably selected from formula M

[0497] R a -B 1 -(Z b -B 2 ) m -R b M

[0498] Each group, appearing identically or differently each time, and independently of each other, has the following meaning:

[0499] R a and R b It is P, P-Sp-, H, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, SF5, or a straight-chain or branched alkyl group having 1 to 25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may be independently separated from each other by -C(R 0 )=C(R 00)-、-C≡C-、-N(R 00 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O- are substituted in such a way that O and / or S atoms are not directly connected to each other, and in addition, one or more H atoms may be substituted by F, Cl, Br, I, CN, P or P-Sp-, wherein if B 1 and / or B 2 If it contains saturated C atoms, then R a and / or R b It can also represent a group that is spirotropically attached to the saturated carbon atom.

[0500] Wherein group R a and R b At least one of them represents or contains the group P or P-Sp-,

[0501] P is a polymerizable group.

[0502] Sp can be a spacer group or a single bond.

[0503] B 1 and B 2 It is an aromatic, heteroaromatic, alicyclic, or heterocyclic group, having 4 to 25 ring atoms, and may also contain a fused ring. It may be unsubstituted or mono- or polysubstituted with L atoms.

[0504] Z b is -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR 0 R 00 Or a single key,

[0505] R 0 and R 00 Each of these can independently represent H or an alkyl group having 1 to 12 carbon atoms.

[0506] m represents 0, 1, 2, 3, or 4.

[0507] n1 represents 1, 2, 3, or 4.

[0508] L is P, P-Sp-, OH, CH2OH, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(Rx )2、-C(=O)Y 1 -C(=O)R x -N(R) x 2. Optionally substituted silyl groups, optionally substituted aryl groups having 6 to 20 carbon atoms, or straight-chain or branched alkyl groups having 1 to 25 carbon atoms, alkoxy groups, alkyl carbonyl groups, alkoxy carbonyl groups, alkyl carbonyloxy groups, or alkoxy carbonyloxy groups, wherein one or more H atoms may be substituted with F, Cl, P, or P-Sp-.

[0509] P and Sp have the meanings indicated above.

[0510] Y 1 Indicates halogen,

[0511] R x The symbol represents P, P-Sp-, H, halogen, straight-chain, branched, or cyclic alkyl groups having 1 to 25 carbon atoms, wherein one or more non-adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and wherein one or more H atoms may be replaced by F, Cl, P, or P-Sp-, optionally substituted aryl or aryloxy groups having 6 to 40 carbon atoms, or optionally substituted heteroaryl or heteroaryloxy groups having 2 to 40 carbon atoms.

[0512] The particularly preferred compounds of formula M are those in which B 1 and B 2 Each of these groups independently represents 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl, naphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydro-phenanthrene-2,7-diyl, anthracene-2,7-diyl, fluorene-2,7-diyl, coumarin, and flavonoids, wherein one or more CH groups in these groups may be replaced by N, cyclohexane-1,4-diyl, wherein one or more non-adjacent CH2 groups may be replaced by O and / or S, 1 ,4-cyclohexenyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, piperidine-1,4-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, indane-2,5-diyl or octahydro-4,7-bridged methylene indane-2,5-diyl, wherein all of these groups may be unsubstituted or mono- or polysubstituted as described above.

[0513] The particularly preferred compound of formula M is one in which B 1 and B 2Those that independently represent 1,4-phenylene, 1,3-phenylene, naphthalene-1,4-diyl, or naphthalene-2,6-diyl,

[0514] Further preferred are polymerizable compounds selected from the following formula:

[0515]

[0516]

[0517]

[0518]

[0519]

[0520] Each group, when appearing in the same or different manner, and independently of each other, has the following meaning:

[0521] P 1 ,P 2 ,P 3 The polymerizable group is preferably selected from ethyleneoxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane, and epoxy groups.

[0522] Sp 1 Sp 2 Sp 3 It is a single bond or a spacer group, wherein in addition, the group P 1 -Sp 1 -、P 1 -Sp 2 -and P 3 -Sp 3 One or more of the representations R in - aa The condition is that the group P exists. 1 -Sp 1 -、P 2 -Sp 2 and P 3 -Sp 3 - at least one of them is different from R aa Preferred -(CH2) p1 -、-(CH2) p1 -O-、-(CH2) p1 -CO-O- or -(CH2) p1 -O-CO-O-, where p1 is an integer from 1 to 12.

[0523] R aaIt is H, F, Cl, CN, or a straight-chain or branched alkyl group having 1-25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may be independently coupled to each other such that the O and / or S atoms are not directly connected to each other by -C(R) 0 )=C(R 00 )-、-C≡C-、-N(R 0 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O-, and in addition, one or more H atoms may be replaced by F, Cl, CN or P. 1 -Sp 1 - Alternatively preferred are straight-chain or branched groups having 1-12 carbon atoms, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkyl carbonyl, alkoxy carbonyl, alkyl carbonyloxy, or alkoxy carbonyloxy (wherein the alkenyl and alkynyl groups have at least two carbon atoms and the branched groups have at least three carbon atoms), and wherein R aa Does not represent or contain the group P 1 、P 2 or P 3 ,

[0524] R 0 ,R 00 It is H or an alkyl group having 1-12 carbon atoms.

[0525] R y and R z It can be H, F, CH3 or CF3.

[0526] X 1 ,X 2 ,X 3 It can be -CO-O-, -O-CO-, or a single bond.

[0527] Z M1 -O-, -CO-, -C(R) y R z - or -CF2CF2-,

[0528] Z M2 Z M3 It can be -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2-, or -(CH2). n - where n is 2, 3, or 4.

[0529] L is F, Cl, CN, or a straight or branched chain with 1-12 C atoms, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyl, or alkoxycarbonyloxy.

[0530] L',L" represents H, F, or Cl.

[0531] k is 0 or 1.

[0532] r can be 0, 1, 2, 3, or 4.

[0533] s is 0, 1, 2 or 3.

[0534] t is 0, 1, or 2.

[0535] x is 0 or 1.

[0536] The compounds M2 and M13 are highly preferred, especially those containing exactly two polymerizable groups P. 1 and P 2 Bireactive compounds.

[0537] Further preferred compounds are those selected from formulas M17-M32, particularly formulas M20, M22, M24, M27, M30, and M32, especially those containing three polymerizable groups P. 1 、P 2 and P 3 Tri-reactive compounds.

[0538] In compounds of formulas M1-M31

[0539] Preferred

[0540]

[0541] The L, each time it appears, has one of the meanings given in the context, and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, Cl, CH3, OCH3, COCH3 or OCF3, and most preferably F or OCH3.

[0542] Preferred compounds of formulas M1-M32 are those in which P 1 、P 2 and P 3 Those representing acrylate group, methacrylate group, oxetane or epoxy group are very preferred, acrylate group or methacrylate group is most preferred.

[0543] Further preferred compounds of formulas M1-M32 are those in which Sp 1 Sp2 and Sp 3 Those that are single keys.

[0544] Further preferred compounds of formulas M1-M32 are those in which Sp 1 Sp 2 and Sp 3 One of them is a single bond and Sp 1 Sp 2 and Sp 3 Another one that differs from single bonds.

[0545] Further preferred compounds of formulas M1-M32 are those with Sp groups that are different from single bonds. 1 Sp 2 and Sp 3 It represents -(CH2) s1 Those with -X"-, where s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5, and X" is the connection to the benzene ring and is -O-, -O-CO-, -CO-O, -O-CO-O- or a single bond.

[0546] Further preferred compounds of formula M are those selected from those in Table D below, especially those of formulas RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-64, RM-74, RM-76, RM-88, RM-92, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-142, RM-153, RM-155, RM-158 and RM-159.

[0547] LC media containing one, two, or three polymerizable compounds of formula M are particularly preferred.

[0548] Further preferred are LC media containing two or more bireactive polymerizable compounds of formula M, preferably selected from formulas M1-M16, and very preferably selected from formulas M2 and M13.

[0549] Further preferred are LC media comprising one or more bireactive polymerizable compounds of formula M, preferably selected from formulas M1-M16, very preferably formulas M2 and M13, and one or more trireactive polymerizable compounds of formula M, preferably selected from formulas M17-M32, very preferably formulas M20, M22, M24, M27, M30 and M32.

[0550] Further preferred are LC media comprising one or more polymerizable compounds of formula M, wherein at least one r is not 0, or at least one of s and t is not 0, very preferably selected from formulas M2, M13, M22, M24, M27, M30 and M32, and wherein L is selected from the preferred groups shown above, most preferably F and OCH3.

[0551] Further preferred are polymerizable compounds that exhibit absorption at wavelengths of 340-380 nm, preferably selected from formula M, very preferably from formulas M1-M32, and most preferably from the group consisting of the above formulas in Table D.

[0552] Optionally, one or more polymerization initiators are added to the LC medium. Suitable polymerization conditions, as well as suitable initiator types and amounts, are known to those skilled in the art and described in the literature. Suitable initiators for free radical polymerization include, for example, commercially available photoinitiators. or (Ciba AG). If a polymerization initiator is used, its proportion is preferably 0.001-5 wt%, particularly preferably 0.001-1 wt%.

[0553] The polymerizable compounds of this invention are also suitable for polymerization without an initiator, which has significant advantages, such as lower material costs, and especially less contamination of the LC medium by possible residual initiator or its degradation products. Therefore, polymerization can also be carried out without the addition of an initiator. Thus, in a preferred embodiment, the LC medium does not contain a polymerization initiator.

[0554] The LC medium may also contain one or more stabilizers to prevent unwanted spontaneous polymerization of RM, for example, during storage or transportation. Suitable types and amounts of stabilizers are known to those skilled in the art and are described in the literature. Particularly suitable, for example, Ciba AG series of commercially available stabilizers, such as 1076. If stabilizers are used, their proportion, based on the total amount of RM or polymerizable component (component A), is preferably 10-50,000 ppm, particularly preferably 50-5,000 ppm.

[0555] In a preferred embodiment, the LC medium contains one or more chiral dopants, preferably at a concentration of 0.01-1 wt%, very preferably 0.05-0.5 wt%. The chiral dopants are preferably selected from compounds in Table B below, and very preferably R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, and R- or S-5011.

[0556] In another preferred embodiment, the LC medium contains a racemic form of one or more chiral dopants, preferably selected from the chiral dopants mentioned in the previous paragraph.

[0557] In another preferred embodiment of the invention, the LC medium contains one or more other stabilizers, preferably selected from the following formula.

[0558]

[0559] Each group is independent of the others and, each time it appears, has the same or different meanings as follows:

[0560] R a-d It is a straight-chain or branched alkyl group having 1-10, preferably 1-6, and very preferably 1-4 carbon atoms, with methyl being the most preferred.

[0561] X S It can be H, CH3, OH or O ● ,

[0562] A S It is a straight-chain, branched, or cyclohexane group having 1-20 carbon atoms, which may be optionally substituted.

[0563] n is an integer from 1 to 6, preferably 3.

[0564] Preferred S3 stabilizers are selected from S3A.

[0565]

[0566] Where n2 is an integer from 1 to 12, and the group (CH2) is included. n2 One or more H atoms in the H atom may be optionally replaced by methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0567] The preferred stabilizers are selected from the following formula

[0568]

[0569]

[0570]

[0571] In a preferred embodiment, the liquid crystal medium contains one or more stabilizers selected from formulas S1-1, S2-1, S3-1, S3-1, and S3-3.

[0572] In a preferred embodiment, the liquid crystal medium comprises one or more stabilizers selected from Table C below.

[0573] The proportion of stabilizers in the liquid crystal medium, such as those of formulas S1-S3, is preferably 10-500 ppm, and very preferably 20-100 ppm.

[0574] In another preferred embodiment, the LC medium of the present invention contains a self-aligning (SA) additive, preferably at a concentration of 0.1-2.5%.

[0575] In another preferred embodiment, the LC medium of the present invention contains a self-aligning (SA) additive, preferably at a concentration of 0.1-2.5%.

[0576] In a preferred embodiment, the SA-VA display of the present invention does not contain a polyimide alignment layer. In another preferred embodiment, the SA-VA display according to the preferred embodiment contains a polyimide alignment layer.

[0577] The preferred SA additive used in this preferred embodiment is selected from compounds containing mesocrystalline groups and straight-chain or branched alkyl side chains capped by one or more polar anchoring groups selected from hydroxyl, carboxyl, amino, or thiol groups.

[0578] Further preferred SA additives contain one or more polymerizable groups, optionally linked to mesocrystalline groups via spacer groups. These polymerizable SA additives can be polymerized in an LC medium under conditions similar to those used for RM in the PSA process.

[0579] Suitable SA additives for inducing vertical alignment, particularly SA additives for SA-VA mode displays, are disclosed, for example, in US 2013 / 0182202 A1, US 2014 / 0838581 A1, US 2015 / 0166890 A1 and US 2015 / 0252265 A1.

[0580] In another preferred embodiment, the LC media or polymer-stabilized SA-VA display of the present invention contains one or more self-aligning additives selected from Table E below.

[0581] In another preferred embodiment, the LC medium of the present invention contains one or more SA additives, preferably selected from Formula II or its sub-formulas or selected from Table E, at a concentration of 0.1-5%, very preferably 0.2-3%, and most preferably 0.2-1.5%.

[0582] In another preferred embodiment, the LC media and display according to the invention do not contain self-aligning additives, and in particular, they do not contain compounds selected from Table E below.

[0583] A preferred embodiment of the present invention relates to a method for manufacturing a PSA display as described in the context, the method comprising one or more of the following features:

[0584] - In the two-step method, the polymerizable LC medium is irradiated with UV light, including a first UV exposure step (“UV1 step”), in which a voltage is applied to create a tilt angle, and a second UV exposure step (“UV2 step”), in which no voltage is applied to complete the polymerization.

[0585] - Using a strength of 0.5 mW / cm 2 -10mW / cm 2 UV light irradiation from a UV lamp with a wavelength of 300-380 nm can polymerize LC media, preferably in the UV2 step, and optionally also in the UV1 step.

[0586] -Use UV light irradiation with wavelengths ≥340nm, preferably ≤420nm, very preferably 340-380nm, more preferably 350 to <370nm, and most preferably 355-368nm to irradiate polymerizable LC media.

[0587] - While applying voltage to the electrodes of the display, polymerizable LC dielectric is irradiated with UV light.

[0588] -Use UV-LED lamps for UV irradiation.

[0589] For example, this preferred method can be carried out by using the desired UV lamp or by using bandpass and / or cutoff filters that are substantially transmissive to UV light of each desired wavelength and substantially blocking to each undesirable wavelength. For example, when UV irradiation with wavelength λ of 300-400 nm is required, a broadband filter that is substantially transmissive to wavelengths 300 nm < λ < 400 nm can be used for UV exposure. When UV irradiation with wavelength λ greater than 340 nm is required, a cutoff filter that is substantially transmissive to wavelengths λ > 340 nm can be used for UV irradiation.

[0590] Preferably, UV-LED lamps are used for UV irradiation.

[0591] In the PSA process, using UV-LED lamps with only a narrow emission peak offers several advantages, such as more efficient transfer of light energy to polymerizable compounds in the LC medium, depending on the selection of suitable polymerizable compounds that exhibit absorption at the LED lamp's emission wavelength. This allows for reductions in UV intensity and / or UV irradiation time, thereby enabling shorter cycle times and saving energy and production costs. Another advantage is the narrow emission spectrum of the lamp, which makes it easier to select appropriate wavelengths for photopolymerization.

[0592] Very preferably, the UV light source is a UV-LED lamp that emits light with a wavelength of 340-400nm, more preferably 340-380nm. Particularly preferred are UV-LED lamps that emit UV light with a wavelength of 365nm.

[0593] This preferred method enables the manufacture of displays by using longer UV wavelengths, thereby reducing or even avoiding the harmful and destructive effects of short UV components.

[0594] UV irradiation energy is typically 6-100J, depending on the production process conditions.

[0595] The LC medium of the present invention may additionally contain one or more other components or additives, preferably selected from the following list, including but not limited to comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobic agents, binders, flow improvers, defoamers, degassing agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles.

[0596] Further additives can be polymerizable or non-polymerizable. Polymerizable additives are correspondingly classified as polymerizable components or component A). Correspondingly, non-polymerizable additives are classified as non-polymerizable components or component B.

[0597] The LC medium preferably has a nematic LC phase.

[0598] In addition, 0 to 15% by weight of a pleochroic dye, nanoparticles, conductive salts, preferably ammonium ethyl dimethyl dodecyl 4-hexyloxybenzoate, ammonium tetrabutyltetraphenylborate, or complex salts of crown ethers can be added to the LC medium (see, for example, Haller et al., Mol. Cryst. Liq. Cryst.). 24 , 249-258 (1973)) are used to improve conductivity, or to add substances to modify the dielectric anisotropy, viscosity and / or orientation of the nematic phase. Such substances are described, for example, in DE-A 22 09 127, 2240 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

[0599] The individual components of the preferred embodiments of the LC media listed above according to the invention are known, or the methods for preparing them can be obtained from the prior art by those skilled in the art, as they are based on standard methods described in the literature. For example, corresponding compounds of formula CY are described in EP-A-0 364 538. For example, corresponding compounds of formula ZK are described in DE-A-26 36 684 and DE-A-33 21 373.

[0600] The LC media used according to the invention can be prepared by conventional methods, for example by mixing one or more of the compounds mentioned above with one or more polymerizable compounds as defined above, and optionally with other liquid crystal compounds and / or additives. Typically, a desired amount of the component used in a small quantity is dissolved in the component constituting the main component, which is advantageously carried out at elevated temperatures. The solution of the components can also be mixed in an organic solvent such as acetone, chloroform, or methanol, and the solvent is removed again, for example by distillation after thorough mixing. The invention also relates to a method for preparing the LC media according to the invention.

[0601] It will be self-evident to those skilled in the art that the LC medium according to the present invention may also contain, for example, compounds in which H, N, O, Cl, and F are replaced by corresponding isotopes such as deuterium.

[0602] The following examples illustrate the invention but do not limit it. However, they demonstrate to those skilled in the art preferred mixture concepts, as well as preferred compounds used and their respective concentrations, and combinations thereof. Furthermore, the examples clarify which properties and combinations of properties are available. Preferred mixture compositions are shown in Table A below.

[0603] Table A

[0604] In Table A, m and n are independent integers from 1 to 12, preferably 1, 2, 3, 4, 5, or 6, k is 0, 1, 2, 3, 4, 5, or 6, and (O)C m H 2m+1 C represents m H 2m+1 or OC m H 2m+1 .

[0605]

[0606]

[0607]

[0608]

[0609]

[0610]

[0611]

[0612]

[0613]

[0614]

[0615]

[0616]

[0617]

[0618]

[0619]

[0620]

[0621]

[0622]

[0623]

[0624]

[0625]

[0626] In a first preferred embodiment of the invention, the LC dielectric of the invention, especially those having positive dielectric anisotropy, comprises one or more compounds selected from the compounds in Table A1.

[0627] In a second preferred embodiment of the invention, the LC medium according to the invention, especially those having negative dielectric anisotropy, comprises one or more compounds selected from the compounds in Table A2.

[0628] Table B

[0629] Table B shows the chiral dopants that can be added to the LC media of this invention.

[0630]

[0631]

[0632] The LC dielectric preferably contains 0-10 wt%, particularly 0.01-5 wt%, and especially preferably 0.1-3 wt% of dopant. The LC dielectric preferably contains one or more dopants selected from the compounds in Table B.

[0633] Table C

[0634] Table C shows possible stabilizers that can be added to the LC media of the present invention. Here, n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and the terminal methyl group is not shown.

[0635]

[0636]

[0637]

[0638]

[0639]

[0640]

[0641]

[0642] The LC medium preferably contains 0-10 wt%, particularly 1 ppm-5 wt%, and especially preferably 1 ppm-1 wt% of a stabilizer. The LC medium preferably contains one or more stabilizers selected from the compounds in Table C.

[0643] Table D

[0644] Table D shows exemplary reactive mesocrystalline compounds that can be used in the LC media of this invention.

[0645]

[0646]

[0647]

[0648]

[0649]

[0650]

[0651]

[0652]

[0653]

[0654]

[0655]

[0656]

[0657]

[0658]

[0659]

[0660]

[0661]

[0662]

[0663]

[0664]

[0665]

[0666] In a preferred embodiment, the mixture of the present invention comprises one or more polymerizable compounds, preferably selected from polymerizable compounds of formulas RM-1 to RM-144. Among these, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-64, RM-74, RM-76, RM-88, RM-102, RM-103, RM-109, RM-117, RM-120, RM-121, RM-122, and RM-145 to RM-152 are particularly preferred.

[0667] In another preferred embodiment, the mixture of the present invention comprises one or more polymerizable compounds selected from formulas RM-145 to RM-152, with formulas RM-147 to RM-152 being particularly preferred.

[0668] Table E

[0669] Table E shows the self-aligning additives for vertical alignment, which can be used together with the polymerizable compounds of Formula I in the LC media of the SA-VA and SA-FFS displays of the present invention:

[0670]

[0671]

[0672]

[0673]

[0674]

[0675]

[0676]

[0677]

[0678]

[0679]

[0680]

[0681] In a preferred embodiment, the LC medium of the SA-VA and SA-FFS displays of the present invention comprises one or more SA additives selected from SA-1 to SA-48 (preferably selected from SA-14 to SA-48, very preferably SA-20 to SA-34 and SA-44) and one or more RMs of formula I. Detailed Implementation

[0682] Example

[0683] The following examples illustrate the invention but do not limit it. However, they demonstrate to those skilled in the art the concept of preferred mixtures and the preferred compounds used, their corresponding concentrations, and combinations thereof. Furthermore, the examples illustrate the available properties and combinations of properties.

[0684] In addition, the following abbreviations and symbols were used:

[0685] V0 represents the threshold voltage at 20℃, capacitive [V].

[0686] n e This indicates the unusual refractive index at 20°C and 589 nm.

[0687] n o This represents the ordinary refractive index at 20°C and 589 nm.

[0688] △n represents the optical anisotropy at 20℃ and 589nm.

[0689] ε ⊥ This represents the dielectric constant perpendicular to the director at 20℃ and 1kHz.

[0690] ε || This represents the dielectric constant parallel to the director at 20℃ and 1kHz.

[0691] Δε represents the dielectric anisotropy at 20℃ and 1kHz.

[0692] cl.p., T(N,I) represents the clearing point [°C].

[0693] γ1 represents the rotational viscosity [mPa·s] at 20℃.

[0694] K1 represents the elastic constant at 20℃, and the "oblique stretching" deformation [pN].

[0695] K2 represents the elastic constant at 20℃, and the "torsional" deformation [pN].

[0696] K3 represents the elastic constant at 20°C, and the bending deformation [pN].

[0697] Unless otherwise expressly stated, all concentrations in this application are given as weight percentages and refer to the entire mixture in question, which contains all solid or liquid crystal components (without solvent).

[0698] Unless otherwise stated, all temperature values ​​indicated in this application, such as melting point T(C,N), transformation from smectic (S) to nematic (N) T(S,N), and clearing point T(N,I), are expressed in degrees Celsius (°C). Mp represents the melting point, and cl.p. = clearing point. Furthermore, C = liquid crystal phase, N = nematic phase, S = smectic phase, and I = isotropic phase. The data between these symbols represent the transformation temperature.

[0699] All physical properties are and have been determined according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals” Status November 1997, Merck KGaA, Germany, and are applicable to a temperature of 20°C, with Δn measured at 589 nm and Δε measured at 1 kHz, unless otherwise explicitly stated in each case.

[0700] The term "threshold voltage" used in this invention refers to the capacitive threshold (V0), which is also known as the Freedericks threshold, unless otherwise stated. In embodiments, the optical threshold is also, as is generally the case, for 10% relative contrast (V0). 10 (This is given.)

[0701] Unless otherwise stated, the method of polymerizing polymerizable compounds in a PSA display as described in the context, wherein the LC medium is in the form of a liquid crystal phase, preferably a nematic phase, is carried out at a temperature, and most preferably at room temperature.

[0702] Unless otherwise stated, the preparation of test kits and the measurement of their electro-optic and other properties shall be carried out by the methods described below or similar methods.

[0703] The display used to measure capacitive threshold voltage consists of two planar parallel glass outer plates spaced 25 μm apart. Each outer plate has an electrode layer on its inner side and an unrubbed polyimide alignment layer on its top, which results in vertical edge alignment of liquid crystal molecules.

[0704] A PSVA display or PSVA test chamber for measuring tilt angles consists of two parallel, planar glass outer plates spaced 4 μm apart. Unless otherwise specified, each outer plate has an electrode layer on its inner side and a polyimide alignment layer on top, wherein the two polyimide layers rub against each other antiparallel, resulting in vertical edge alignment of the liquid crystal molecules. A SAVA display or test chamber has the same structure, but one or two polyimide layers are omitted.

[0705] Polymerizable compounds are polymerized in a display or test chamber by irradiating the display with UV light of a defined intensity for a predetermined time while simultaneously applying a voltage (typically 10V-30V AC, 1kHz) to the display. In the examples, unless otherwise specified, metal halides or high-pressure Hg lamps and 50 to 100 mW / cm² are used. 2 The polymerization intensity was determined using a standard instrument (the high end of the Hoenle UV meter with a UV sensor).

[0706] The tilt angle was determined using Axometrics' Mueller Matrix Polarimeter "AxoScan". Smaller values ​​(i.e., larger deviations relative to a 90° angle) correspond to larger tilts in this case.

[0707] Unless otherwise stated, the term "tilt angle" means the angle between the LC director and the substrate, and "LC director" means the preferred orientation of the optical principal axis of the LC molecules in a layer of LC molecules with uniform orientation, corresponding to the long axis of the molecules in the case of rod-shaped, uniaxial positive birefringent LC molecules.

[0708] Comparative Example 1

[0709] The nematic LC bulk mixture C1 is prepared as follows:

[0710]

[0711]

[0712] The mixture contains compounds of formula IA, B(S)-2O-O4 and B(S)-2O-O5, and compounds of formula IC, CC-3-V and CC-3-V1, but does not contain compounds of formula IB.

[0713] Example 1

[0714] The nematic LC bulk mixture N1 is prepared as follows:

[0715]

[0716] The mixture contains compounds B(S)-2O-O4 and B(S)-2O-O5 of formula IA, compound CLY-3-O2 of formula IB, and compounds CC-3-V and CC-3-V1 of formula IC.

[0717] Comparative Example 2

[0718] The nematic LC bulk mixture C2 is prepared as follows:

[0719]

[0720]

[0721] The mixture contains compounds of formula IA, B(S)-2O-O4, B(S)-2O-O5 and B(S)-2O-O6, and compounds of formula IC, CC-3-V and CC-3-V1, but does not contain compounds of formula IB.

[0722] Example 2

[0723] The nematic LC bulk mixture N2 is prepared as follows:

[0724]

[0725] The mixture contains compounds of formula IA, namely B(S)-2O-O4, B(S)-2O-O5 and B(S)-2O-O6, compound of formula IB, namely CLY-3-O2, and compounds of formula IC, namely CC-3-V and CC-3-V1.

[0726] polymerizable mixtures

[0727] The polymerizable blends are prepared by adding polymerizable compound M1 and stabilizer S1 to a nematic LC host blend as described above. The polymerizable blend compositions are shown in Table 1 below.

[0728] Table 1 - Polymerizable Mixtures

[0729] mixture PC1 P1 PC2 P2 main body C1 N1 C2 N2 ％M1 0.4 0.4 0.4 0.4 ％S1 0.005 0.005 0.005 0.005

[0730]

[0731] VHR

[0732] The VHR of the polymerizable mixture is measured at 60°C with a voltage of 1V / 60Hz before and after a certain period of UV irradiation, and after a certain period of backlight load (BL).

[0733] Optical stress typically leads to a decrease in VHR in LC mixtures; therefore, the smaller the absolute decrease in VHR after stress, the better the performance in display applications. The results are shown in Table 2.

[0734] Table 2 - VHR

[0735]

[0736]

[0737] As can be seen from Table 2, the VHR values ​​of the polymerizable mixtures P1 and P2 according to the present invention are significantly higher than those of the polymerizable reference mixtures PC1 and PC2.

[0738] Tilt stability

[0739] Tilt stability, or the change in tilt angle after repeated electrical stress, is a standard used to assess the risk of image sticking. Low values ​​of tilt angle change indicate high tilt stability and a low potential risk of image sticking.

[0740] To determine tilt stability, the polymerizable mixture was polymerized in a VA-tilt test chamber with a chamber thickness of approximately 4 μm and two substrates having an antiparallel friction polyimide layer (JALS-2096-R1). The polymerization was performed at room temperature using a high-pressure Hg lamp at 50 mW / cm². 2 and 14V PP 6J of UV exposure was performed with a square wave voltage applied at 60Hz. Initially, at a voltage of 60V... PP Axometrics was used after applying a square wave voltage and 60Hz electrical stress for 72 hours and after releasing the electrical stress for 24 hours. Measure the tilt angle. Determine the change in tilt angle Δ based on the following equation.

[0741] tilt 在应力后 -tilt 在倾斜角生成后 =Δ tilt

[0742] And this is shown in Table 3 below. The lower the value of Δtilt, the higher the tilt stability.

[0743] Table 3 - Tilt Stability

[0744]

[0745] 1) After electrical stress

[0746] 2) After release (24 hours after electrical stress)

[0747] As can be seen from Table 3, the polymerizable mixtures P1 and P2 according to the present invention exhibit similar or even better tilt stability than the polymerizable reference mixtures PC1 and PC2.

Claims

1. LC media, including Polymerizable component A), comprising one or more polymerizable compounds, and Liquid crystal component B), hereinafter also referred to as "LC host mixture", contains one or more mesocrystalline or liquid crystal compounds. Component B) comprises one or more compounds of formula IA, one or more compounds of formula IB, and one or more compounds of formula IC as defined below. Each of the groups, in each occurrence, either identically or differently, and each independently of the others, has the following meaning: R 1 R 2 It is a straight-chain, branched, or cyclic alkyl group having 1-25 carbon atoms, wherein one or more non-adjacent CH2- groups are optionally surrounded by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -,-C≡C-, The O- and / or S- atoms are substituted in such a way that they are not directly connected to each other, and one or more H atoms are optionally substituted by F or Cl. R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms. L 1 L 2 The preferred form is F or Cl, with F being preferred. Alkyl refers to an alkyl group having 1 to 7 carbon atoms. alkenyl is an alkenyl group having 2 to 5 carbon atoms. in, The proportion of compound of formula IA in component B) of the LC medium is >5% by weight.

2. The LC medium according to claim 1, characterized in that the compound of formula IA is selected from formulas IA-1 to IA-10: Wherein alkyl and alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, alkenyl and alkenyl* each independently represent a straight-chain alkenyl group having 2-6 carbon atoms, alkoxy and alkoxy* each independently represent a straight-chain alkoxy group having 1-6 carbon atoms, and L 1 and L 2 Each can be represented independently as F or Cl, with F being preferred.

3. The LC medium according to claim 1 or 2, characterized in that... Compounds of formula IB are selected from the following sub-formulas: Where alkyl and alkyl* independently represent straight-chain alkyl groups having 1-6 C atoms and (O) represents an oxygen atom or a single bond.

4. The LC medium according to any one of claims 1 to 3, characterized in that... The compounds of formula IC are selected from formulas IC-1 to IC-12:

5. The LC medium according to any one of claims 1 to 4, characterized in that... It additionally contains one or more compounds of formula II Each of the groups, independently of each other and in the same or different manner each time it appears, has the following meanings: R 1 and R 2 It is a straight-chain, branched, or cyclic alkyl group having 1-25 carbon atoms, wherein one or more non-adjacent CH2- groups are optionally surrounded by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -,-C≡C-, The O- and / or S- atoms are replaced in such a way that they are not directly bonded to each other, and one or more H atoms are optionally replaced by F or Cl, preferably alkyl or alkoxy groups having 1-6 C atoms. R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms. A 1 and A 2 Groups selected from the following formulas The preferred selection is from formulas A1, A2, A3, A4, A5, A6, A9, and A10; the most preferred selection is from formulas A1, A2, A3, A4, A5, A9, and A10. Z 1 and Z 2 -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2- -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O- or single bonds, preferably single bonds. L 1 L 2 L 3 and L 4 The solvent is F, Cl, OCF3, CF3, CH3, CH2F, or CHF2, preferably F or Cl, and very preferably F. Y is H, F, Cl, CF3, CHF2, or CH3, preferably H or CH3, and very preferably H. L C It is CH3 or OCH3, preferably CH3. a1 is 1 or 2. a2 is 0 or 1.

6. The LC medium according to any one of claims 1 to 5, characterized in that... It contains one or more compounds of formula II selected from formulas IIA, IIB, IIC, and IID. in R 2A and R 2B Each group independently represents H, an alkyl or alkenyl group having up to 15 carbon atoms, which is unsubstituted, monosubstituted with CN or CF3, or at least monosubstituted with a halogen, wherein one or more CH2 groups in these groups may be -O-, -S-, such that the O atom is not directly attached to each other. -C≡C-, -CF₂O-, -OCF₂-, -OC-O-, or -O-CO- can be substituted. L 1 To L 4 Each can be represented independently as F, Cl, CF3, or CHF2. Y represents H, F, Cl, CF3, CHF2, or CH3, preferably H or CH3, and particularly preferably H. Z 2 Z 2B and Z 2D Each of these independently represents a single bond: -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O-. p represents 0, 1, or 2, and Each occurrence of q represents either 0 or 1, either the same or different.

7. The LC medium according to any one of claims 1 to 6, characterized in that... It additionally contains one or more compounds of formula IV. in R 41 This indicates an unsubstituted alkyl group having 1-7 carbon atoms or an unsubstituted alkenyl group having 2-7 carbon atoms, preferably an n-alkyl group, and particularly preferably having 2, 3, 4 or 5 carbon atoms. R 42 The term refers to an unsubstituted alkyl group having 1-7 carbon atoms or an unsubstituted alkoxy group having 1-6 carbon atoms, both preferably having 2-5 carbon atoms, an unsubstituted alkenyl group having 2-7 carbon atoms, preferably having 2, 3 or 4 carbon atoms, more preferably vinyl or 1-propenyl and especially vinyl.

8. The LC medium according to any one of claims 1 to 7, characterized in that it additionally comprises one or more compounds of formula V. in R 51 and R 52 They are independent of each other for R 41 and R 42 One of the given meanings and preferred meanings refers to an alkyl group having 1-7 carbon atoms, preferably an n-alkyl group, particularly preferably an n-alkyl group having 1-5 carbon atoms; an alkoxy group having 1-7 carbon atoms, preferably an n-alkoxy group, particularly preferably an n-alkoxy group having 2-5 carbon atoms; and an alkoxyalkyl, alkenyl, or alkenyloxy group having 2-7 carbon atoms, preferably having 2-4 carbon atoms, preferably an alkenyloxy group. Same or different in Preferred representation Z 51 Z 52 Each of these independently represents -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or a single bond, preferably -CH2-CH2-, -CH2-O-, or a single bond, and particularly preferably a single bond. n is 1 or 2.

9. The LC medium according to any one of claims 1 to 8, characterized in that... It additionally contains one or more compounds of formula IV-16. Where R 1 and R 2 Each of these terms independently represents a straight-chain alkyl group having 1 to 6 carbon atoms.

10. The LC medium according to one or more of claims 1 to 9, characterized in that, The polymerizable compound is selected from formula I. R a -B 1 -(Z b -B 2 ) m -R b I Each of the groups, in each occurrence, either identically or differently, and each independently of the others, has the following meaning: R a and R b It is P, P-Sp-, H, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, SF5, or a straight-chain or branched alkyl group having 1 to 25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may be independently separated from each other by -C(R) 0 )=C(R 00 -, -C≡C-, -N(R) 00 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O- are substituted in such a way that O and / or S atoms are not directly connected to each other, and wherein one or more H atoms may be substituted by F, Cl, Br, I, CN, P or P-Sp-, wherein if B 1 and / or B 2 If it contains saturated C atoms, then R a and / or R b It can also represent a group that is spirotropically attached to the saturated carbon atom. Wherein group R a and R b At least one of them represents or contains the group P or P-Sp-, P is a polymerizable group. Sp can be a spacer group or a single bond. B 1 and B 2 It is an aromatic, heteroaromatic, alicyclic, or heterocyclic group, having 4 to 25 ring atoms, and may also contain a fused ring. It may be unsubstituted or mono- or polysubstituted with L atoms. Z b is -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH 2- , -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, CR 0 R 00 Or a single key, R 0 and R 00 It is H or an alkyl group having 1 to 12 carbon atoms. m is 0, 1, 2, 3, or 4. n1 is 1, 2, 3, or 4. L is P, P-Sp-, OH, CH2OH, 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. Optionally substituted silyl groups, optionally substituted aryl groups having 6 to 20 carbon atoms, or straight-chain or branched alkyl groups having 1 to 25 carbon atoms, alkoxy groups, alkyl carbonyl groups, alkoxy carbonyl groups, alkyl carbonyloxy groups, or alkoxy carbonyloxy groups, wherein one or more H atoms may be substituted with F, Cl, P, or P-Sp-. Y 1 Halogen, R x It is P, P-Sp-, H, halogen, a straight-chain, branched, or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and wherein one or more H atoms may be replaced by F, Cl, P, or P-Sp-, optionally substituted aryl or aryloxy groups having 6 to 40 C atoms, or optionally substituted heteroaryl or heteroaryloxy groups having 2 to 40 C atoms.

11. The LC medium according to one or more of claims 1 to 10, characterized in that... Polymerizable compounds are selected from the following formula: Each of the groups, in each occurrence, either identically or differently, and each independently of the others, has the following meaning: P 1 P 2 P 3 The groups are ethyleneoxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetyl, and epoxy. Sp 1 Sp 2 Sp 3 It is a single bond or a spacer group, wherein in addition, the group P 1 -Sp 1 -、P 1 -Sp 2 -and P 3 -Sp 3 One or more of the representations R in - aa The condition is that the group P exists. 1 -Sp 1 -、P 2 -Sp 2 and P 3 -Sp 3 - at least one of them is different from R aa , R aa It is H, F, Cl, CN, or a straight-chain or branched alkyl group having 1-25 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may be independently coupled to each other such that the O and / or S atoms are not directly connected to each other by -C(R) 0 )=C(R 00 -, -C≡C-, -N(R) 0 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O-, and in addition, one or more H atoms may be replaced by F, Cl, CN or P. 1 -Sp 1 -Alternative, R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms. R y and R z It can be H, F, CH3 or CF3. X 1 X 2 X 3 It can be -CO-O-, -O-CO-, or a single bond. Z 1 -O-, -CO-, -C(R) y R z - or -CF2CF2-, Z 2 Z 3 It can be -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2-, or -(CH2). n - where n is 2, 3, or 4. L is F, Cl, CN, or a straight or branched chain with 1-12 C atoms, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyl, or alkoxycarbonyloxy. L', L" are H, F or Cl, r can be 0, 1, 2, 3, or 4. s can be 0, 1, 2, or 3. t is 0, 1, or 2. x is 0 or 1.

12. The LC medium according to any one of claims 1 to 11, characterized in that it additionally comprises one or more additives selected from stabilizers, chiral dopants, polymerization initiators and self-aligning additives.

13. The LC medium according to any one of claims 1 to 12, characterized in that it additionally contains one or more compounds of formula IIB-2. Wherein alkyl and alkyl* each independently represent straight-chain alkyl groups having 1-6 carbon atoms.

14. The LC medium according to any one of claims 1 to 13, characterized in that it contains two or three compounds of formula 1A.

15. The LC medium according to any one of claims 1 to 14, characterized in that it additionally contains one or more compounds of formula III2-1 or III2-2. Where L 11 and L 12 Each can independently represent F, Cl, CF3, or CHF2, with H or F being preferred, and F being the most preferred. (O) represents O or a single bond. R IIIA This refers to an alkyl or alkenyl group, or a Cy-C group, having a maximum of 7 carbon atoms. m H 2m+1 -, n can be 0, 1, 2, 3, 4, 5, or 6, preferably 1, 2, or 3, very preferably 1, and Cy represents an alicyclic group having 3, 4, or 5 ring atoms, which may be optionally alkyl or alkenyl groups having a maximum of 3 C atoms, or substituted with halogen or CN, and preferably represents cyclopropyl, cyclobutyl, or cyclopentyl.

16. A method for preparing an LC medium according to one or more of claims 1 to 15, comprising the following steps: The polymerizable compound is mixed with one or more of the polymerizable compounds as defined in one or more of the claims 1 to 15, and with one or more of the compounds of formula IA, IB and IC as defined in one or more of the claims 1 to 9, and optionally with one or more of the compounds of formula II, III, IV and / or V, and optionally with additional liquid crystal compounds and / or additives, and optionally polymerized.

17. An LC display comprising an LC medium as defined in one or more of claims 1-15.

18. The LC display according to claim 17, wherein it is a PSA or SA display.

19. The LC display according to claim 18, wherein it is a PS-VA, PS-IPS, PS-FFS or SA-VA display.

20. The LC display according to claim 18 or 19, characterized in that it comprises two substrates, at least one of which is transparent to light, an electrode disposed on each substrate, or two electrodes disposed on only one substrate, and a layer of LC medium according to one or more of claims 1-15 located between the substrates, wherein the polymerizable compound is polymerized between the substrates of the display by UV light polymerization.

21. A method for preparing an LC display according to claim 20, comprising the steps of: providing an LC medium according to one or more of claims 1 to 15 between substrates of the display, and polymerizing a polymerizable compound by irradiation with UV light, preferably simultaneously applying a voltage to electrodes of the display.

22. The method according to claim 21, characterized in that the wavelength range of the UV light is 340 to 380 nm.

23. The method according to claim 21 or 22, characterized in that UV-LED lamps are used for UV light irradiation.

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