Liquid crystalline media comprising polymerizable compounds

Abstract

The present invention relates to an LC medium (as a subclass of liquid crystal materials) comprising a polymerizable compound having a monocyclic group; the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays, in particular in LC displays in PSA (polymer sustained alignment) or SA (self-alignment) mode; an LC display in a PSA or SA mode comprising an LC medium; the invention relates to an LC medium and a method for manufacturing an LC display by using the LC medium, in particular to an energy-saving LC display and a preparation method of the energy-saving LC display.

Description

Field of the invention

[0001] The present invention relates to LC media comprising polymerisable compounds having a monocyclic group; for optical, electro-optical and electronic purposes, in particular for use in LC displays, especially in LC displays in PSA (polymer sustained alignment) or SA (self-alignment) mode; PSA or SA mode LC displays comprising the LC media; and methods of manufacturing LC displays, especially energy saving LC displays and energy saving LC display manufacturing methods, using the LC media. BACKGROUND

[0002] The prevalence of 8K and gaming monitors has led to an 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 are using a polymer stabilized (PS) or polymer sustained alignment (PSA) mode, such as a PS-VA (vertically aligned), PS-IPS (in-plane switching) or PS-FFS (fringe field switching) mode or a mode derived therefrom, or a self-alignment (SA) mode, such as a polymer stabilized SA-VA.

[0003] In PS or PSA modes, a small amount (typically 0.1 to 1%) of one or more polymerisable mesogenic compounds, also called RMs (reactive mesogens), is added to the LC medium. After filling the LC medium into the display, the RMs are then polymerized in situ by UV light, while a voltage is applied to the electrodes of the display. As a result, a small tilt angle is created in the LC molecules of the LC medium, which is stabilized by the polymerized RMs. The UV polymerization process, also called "PSA process", is usually performed in two steps, a first UV exposure step ("UV1 step") with voltage applied to create the tilt angle, and a second UV exposure step ("UV2 step") without voltage applied to complete the polymerization of the RMs.

[0004] In SA-VA mode, alignment layers are omitted in the display. Instead, a small amount (typically 0.1 to 2.5%) of a self-alignment (SA) additive is added to the LC medium, which induces the desired alignment, e.g. vertical or planar alignment, in situ by a self-assembly mechanism. The SA additive typically contains an organic mesogenic core group and one or more polar anchor groups, e.g. hydroxyl, carboxyl, amino or thiol groups, connected thereto, which are able to interact with the substrate surface, causing the alignment of the additive on the substrate surface and also inducing the desired alignment in the LC molecules. The SA additive can also contain one or more polymerisable groups, which can be polymerized under similar conditions as the RMs used in the PSA process. In addition to the SA additive, the LC medium can also contain one or more RMs.

[0005] In the display manufacturing process of PSA mode displays, as radiation source for the UV1 step and / or the UV2 step, usually UV C-type and / or UV B-type lamps are used. UV C-type lamps usually have an emission spectrum with the shortest UV wavelength of about 300 nm, while UV B-type lamps usually have an emission spectrum with the shortest UV wavelength of about 320 nm.

[0006] On the other hand, to achieve low viscosity and fast response time, the LC host mixture of the polymerisable LC medium used in PSA mode displays usually contains one or more compounds with alkenyl groups. However, this can lead to a reduced reliability of the mixture and a substantial drop of its voltage holding ratio (VHR) when exposed to the UV light required to polymerise the RM. This is especially problematic when using shorter UV wavelengths of less than 320 nm. This can be overcome by using longer UV wavelength radiation sources for the PSA process. However, a change of the radiation source in a display mass production process is costly and time consuming. Also, this would then pose a problem to finding a RM with an absorption at longer wavelengths that is high enough to enable fast and complete photopolymerisation.

[0007] UV-LED lamps have also been proposed for use in the PSA process as they show lower energy consumption, longer lifetime and due to the narrower emission peak, a more efficient optical energy transfer to the LC medium which allows to reduce the UV intensity and / or the UV irradiation time. This enables to reduce the tact time and saves energy and production costs.

[0008] Therefore, there is a need for polymerisable LC media, especially those based on LC host mixtures containing alkenyl compounds, which contain a RM that can be efficiently polymerised at both UV wavelengths emitted by UV C-type lamps, with the shortest wavelength of about 300 nm, and UV wavelengths emitted by UV B-type lamps, with the shortest wavelength of about 320 nm. There is also a need for polymerisable LC media, especially those based on LC host mixtures containing alkenyl compounds, which show a high reliability and only a small decrease of the VHR value after UV stress, and at the same time show a fast response time.

[0009] Furthermore, there is a great need for PSA or SA displays and LC media and polymerisable compounds for such PSA or SA displays which enable a high specific resistance, while a large operating temperature range, a short response time (even at low temperatures), and a low threshold voltage, a low tilt angle, a high tilt stability, a multiplicity of grey levels, a high contrast ratio and a wide viewing angle, a high reliability and a high VHR value after UV exposure, and in case of polymerisable compounds, a low melting point and a high solubility in the LC host mixture, are achieved. In displays for mobile applications, it is especially desirable to have available LC media which show a low threshold voltage and a high birefringence. SUMMARY

[0010] The present application is based on the object of providing novel suitable materials for PSA or SA displays, in particular RMs and LC media comprising the same, which do not have the above indicated disadvantages or have them to a reduced extent.

[0011] In particular, the present application is based on the object of LC media comprising RMs for PSA or SA displays which enable very high specific resistance values, high VHR values, high reliability, low threshold voltage, short response times, high birefringence, good UV absorption especially in the range of UV wavelengths from 300 to 360 nm, enable fast and complete polymerization of the RMs, allow the generation of low tilt angles, preferably as fast as possible, enable high stability of the tilt angles even after longer times and / or after UV exposure, reduce or prevent the occurrence of "image sticking" and "ODF mura" in the display, and in the case of RMs, enable fast and complete polymerization and high solubility in LC media which are usually used as the bulk mixture of PSA or SA displays, as far as possible.

[0012] Another object of the present application is to provide LC media for PSA displays, wherein the RMs exhibit both fast polymerization speed and good reliability parameters such as high VHR or good tilt stability.

[0013] Another object of the present application is to provide novel LC media containing RMs, in particular for optical, electro-optical and electronic applications, and suitable processes and intermediates for their preparation.

[0014] Another object of the present application is to provide LC media containing RMs which exhibit one or more of the following advantageous effects:

[0015] - which generate the desired degree of tilt angle after exposure to UV light,

[0016] - which lead to good tilt stability,

[0017] - which lead to high and stable VHR and only a small decrease in CHR after UV stress, especially in the case of LC media based on LC bulk mixtures containing alkenyl compounds,

[0018] - which are suitable for PSA displays prepared by polymerization processes using UV-C type lamps and / or UV-B type lamps,

[0019] - which are suitable for PSA displays prepared by polymerization processes using UV-LED lamps,

[0020] - which enable good control of the time frame of the first UV step, in which the tilt angle is generated during the UV treatment,

[0021] - which enables keeping the time frame of the second UV step (where any residual RM is polymerized and the tilt angle is stabilized) as short as possible to minimize energy consumption and production costs,

[0022] - the residual RM has little or no negative impact on LC mixture performance parameters such as VHR, tilt stability, etc. after the first and second UV exposure steps.

[0023] It was found that one or more of these objectives can be achieved by providing an LC medium comprising a polymerizable compound comprising an aromatic mesogenic group as disclosed and claimed in the following.

[0024] The present application relates to an LC medium comprising one or more polymerizable compounds of formula I

[0025]

[0026] wherein each of the radicals, independently of each other and on each occurrence identically or differently, has the following meanings

[0027] P is a polymerizable group,

[0028] Sp is a spacer group or a single bond,

[0029] R a is P-Sp- or R b ,

[0030] R b is H, linear, branched or cyclic alkyl with 1 to 25 C atoms, wherein one or more non- adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -, -C C-, , , , , or atoms are each optionally replaced by F or Cl,

[0031] L is P-Sp-, F, Cl, -CN or linear, branched or cyclic alkyl with 1 to 25 C atoms, wherein one or more non- adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -, -C C-, 、 、 、 、 or one or more H atoms are each optionally replaced by F or CI,

[0032] R 0 , R 00 is H or alkyl having 1 to 12 C atoms,

[0033] r1 is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 1 or 2, most preferably 1,

[0034] and wherein preferably the LC medium does not comprise any polymerisable compounds other than formula I.

[0035] The invention further relates to the use of an LC medium as described above and below in an LC display in PSA or SA mode.

[0036] Furthermore, the invention relates to a process for preparing an LC medium as described above and below, comprising the step of mixing one or more polymerisable compounds of formula I with one or more compounds of formula II as described below and, optionally, with further LC compounds and / or additives.

[0037] Furthermore, the invention relates to an LC display comprising an LC medium according to the invention as described above and below, which is a PSA or SA display, preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display.

[0038] Furthermore, the invention relates to an LC display comprising an LC medium as described above and below, wherein the polymerisable compounds are present in polymerized (ed) form, which LC display is preferably a PSA or SA display, very preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display.

[0039] Furthermore, the invention relates to an LC display of the PSA type, comprising two substrates, at least one of which is transparent to light; electrodes provided on each substrate or two electrodes provided on only one of the substrates; and a layer of an LC medium as described above and below positioned between the substrates, wherein the polymerisable compounds are polymerized between the substrates of the display by UV light polymerization.

[0040] Furthermore, the present application relates to a process for the production of an LC display as described above and below, comprising the following steps: filling or otherwise providing the LC medium as described above and below between the substrates of the display, and polymerizing the polymerizable compounds, preferably by irradiation with UV light, preferably having a wavelength in the range of > 300 nm, more preferably in the range of 300 to 380 nm, very preferably in the range of 300 to 360 nm, and preferably simultaneously applying a voltage to the electrodes of the display.

[0041] Furthermore, the present application relates to a process for the production of an LC display as described above and below, wherein the irradiation of the polymerizable compounds is carried out using a UV C-type lamp and / or a UV B-type lamp.

[0042] When used in a PSA display, the LC medium according to the present application shows the following advantageous properties:

[0043] - suitable tilt generation within a certain process window,

[0044] - fast polymerization leading to a minimum residue of the RM after the UV process,

[0045] - high voltage holding ratio after the UV process,

[0046] - good tilt stability,

[0047] - good VHR,

[0048] - sufficient stability against heat,

[0049] - sufficient solubility in organic solvents commonly used in display manufacturing.

[0050] Furthermore, the LC medium according to the present application shows one or more of the following advantageous properties:

[0051] - which generates a desired degree of tilt angle after exposure to UV light,

[0052] - which provides a high tilt stability,

[0053] - which shows a good UV absorption, especially at longer UV wavelengths, preferably in a range having a wavelength of > 300 nm, more preferably in the range of 300 to 380 nm, very preferably in the range of 300 to 360 nm, and enables fast and complete polymerization of the RM at these wavelengths,

[0054] - which is suitable for PSA displays prepared by polymerization processes using a UV C-type lamp or a UV B-type lamp,

[0055] - which enables to control the time frame of the first UV step, wherein the tilt angle is generated during the UV treatment,

[0056] - which keeps the time frame of the second UV step as short as possible to minimize production costs,

[0057] - which reduces or avoids any negative impact of residual RM on the performance parameters of the LC mixture, such as VHR, tilt stability, etc., after the first and second UV exposure step.

[0058] As described below, alkenyl groups in the compounds of formula II or in other components of the LC medium are not considered to be within the meaning of the term "polymerizable group" as used herein. The polymerization conditions of the polymerizable compounds of the LC medium are preferably chosen such that the alkenyl substituents do not participate in the polymerization reaction. Preferably, the LC medium disclosed and claimed in the present application does not contain additives that initiate or enhance the participation of alkenyl groups in the polymerization reaction.

[0059] Unless otherwise specified, the polymerizable compounds and the compounds of formula II are preferably selected from achiral compounds.

[0060] As used herein, the expression "UV light having a wavelength of... " followed by a given range of wavelengths in nm, or by a given lower or upper limit of wavelength in nm, means that the UV emission spectrum of the respective radiation source has an emission peak which is preferably the highest peak in the respective spectrum within the given range of wavelengths or above the given lower limit of wavelength or below the given upper limit of wavelength, and / or that the UV absorption spectrum of the respective chemical compound has a long wavelength tail or a short wavelength tail which extends into the given range of wavelengths or above the given lower limit of wavelength or below the given upper limit of wavelength.

[0061] As used herein, the term "full width at half maximum" or "FWHM" means the width of a spectral curve measured between those points on the y-axis which are half the maximum amplitude.

[0062] As used herein, the term "substantially transmissive" means that the filter transmits a substantial portion, preferably at least 50% intensity, of the incident light of the desired wavelength. As used herein, the term "substantially blocking" means that the filter does not transmit a substantial portion, preferably at least 50% intensity, of the incident light of the undesired wavelength. As used herein, the term "desired (undesired) wavelength" means, for example for a bandpass filter, a wavelength within (outside) a given range λ, and for a cutoff filter, a wavelength above (below) a given value λ.

[0063] As used herein, the terms "active layer" and "switchable layer" denote a layer in an electro-optical display, e.g. an LC display, which comprises one or more molecules, e.g. LC molecules, having structural and optical anisotropy, which change their orientation when subjected to an external stimulus, e.g. an electric or magnetic field, resulting in a change of the transmission of polarized or non-polarized light by the layer.

[0064] As used herein, the terms "tilt" and "tilt angle" are to be understood to denote a tilted alignment of LC molecules of an LC medium with respect to the surface of a cell in an LC display, preferably a PSA display herein, and are to be understood to include "pre-tilt" and "pre-tilt angle". The tilt angle herein denotes the average angle between the longitudinal molecular axis of the LC molecules (LC director) and the plane parallel outer plate surface forming the LC cell (< 90°). A low absolute value tilt angle herein, i.e. a tilt angle substantially deviating from the 90° angle, corresponds to a large tilt. A suitable method for measuring the tilt angle is given in the Examples. Unless otherwise specified, the tilt angle values disclosed in the context are related to this method of measurement.

[0065] As used herein, the terms "reactive mesogen" and "RM" are to be understood to denote a compound containing a mesogenic or liquid crystalline backbone, and one or more functional groups attached thereto which are suitable for polymerization, and which are also referred to as "polymerizable groups" or "P".

[0066] The term "polymerizable compound" as used herein, unless otherwise indicated, is to be understood to denote a polymerizable monomeric compound.

[0067] The SA-VA display according to the present application will be a polymer stabilized mode as it comprises or is manufactured by using an LC medium containing RMs of formula I and II. Thus, as used herein, even if not explicitly mentioned, the term "SA-VA display" when referring to the display of the present application is to be understood to mean a polymer stabilized SA-VA display.

[0068] As used herein, the term "low molecular weight compound" is to be understood to denote a monomeric and / or a compound which is not prepared by a polymerization reaction, which is opposed to a "polymerizable compound" or "polymer".

[0069] As used herein, the term "non-polymerizable compound" will be understood to denote a compound which does not contain a functional group suitable for polymerization under the conditions usually applied to the polymerization of RMs.

[0070] As used herein, the term "mesogenic group" is known to the person skilled in the art and described in the literature and it denotes a group which contributes substantially to the generation of a liquid crystalline (LC) phase in low molecular weight or polymeric substances due to its anisotropy of attraction and repulsion interactions. A compound comprising a mesogenic group (mesogenic compound) does not necessarily have an LC phase itself. A mesogenic compound can only exhibit LC phase behaviour after mixing with other compounds and / or after polymerisation. Typical mesogenic groups are for example rigid rod-like or disc-like units. The terminology and definitions used in connection with mesogenic 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.

[0071] As used herein, the term "spacer group" (hereinafter also referred to as "Sp") is known to the person 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" denotes a flexible group, for example it is an alkylene group, which is attached to a mesogenic group or to a polymerisable group in a polymerisable mesogenic compound.

[0072]

[0073] If in the formulae shown above and below, terminal groups such as R 1A、2A , R 1 , R 2 , R 11、12、13 , R 31、32 , R 41、42 , R 51、52 , R 61、62 , R 71、72 , R 81、82、83 , R Q , R 0 , R, R M , R S , R S1、S2、S3、S4or L represents alkyl and / or alkoxy, this can be linear or branched. It is preferably linear and has 2, 3, 4, 5, 6 or 7 C atoms and thus preferably represents ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

[0074] If one of the above-mentioned terminal groups represents alkyl, in which one or more CH2groups are replaced by S, this can be linear or branched. It is preferably linear and has 1, 2, 3, 4, 5, 6 or 7 C atoms and thus preferably represents thiomethyl, thioethyl, thiopropyl, thiobutyl, thiopentyl, thiohexyl or thioheptyl.

[0075] Oxaalkyl preferably represents linear 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.

[0076] If one of the above-mentioned terminal groups represents alkoxy or oxaalkyl, it can also contain one or more further oxygen atoms, as long as the oxygen atoms are not directly connected to one another.

[0077] If one of the above-mentioned terminal groups represents alkyl, in which one CH2group has been replaced by -CH=CH-, this can be linear or branched. It is preferably linear and has 2 to 10 C atoms. Thus, in particular, it represents 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; hept-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.

[0078] If one of the terminal groups mentioned above represents an alkyl or alkenyl group which is at least mono-substituted by halogen, this group is preferably straight-chain and the halogen is preferably F or CI. In the case of multiple substitution, the halogen is preferably F. The resulting group also includes perfluorinated groups. In the case of mono-substitution, the fluorine or chlorine substituent can be in any desired position, but is preferably in the omega position.

[0079] In another preferred embodiment, one or more of the terminal groups mentioned above, such as R 1A、2A , R 1 , R 2 , R 11、12、13 , R 31、32 , R 41 、42 , R 51、52 , R 61、62 , R 71、72 , R 81、82、83 , R Q , R 0 , R, R M , R S , R S1、S2、S3、S4 or L, is selected from the group consisting of

[0080]

[0081] -S 1 -F, -O-S 1 -F, -O-S1-O-S2consisting of wherein S 1 is C 1-12 -alkylene or C 2-12 -alkenylene and S 2 is H, C 1-12 -alkyl or C 2-12 -alkenyl, and very preferably selected from the group consisting of

[0082]

[0083] -O(CH2)2OCH3, -OCH2OCH3, -OCH2OCH3, -O(CH2)2OCH3, -O(CH2)3OCH3, -O(CH2)4OCH3, -O(CH2)2F, -O(CH2)3F, -O(CH2)4F.

[0084] If in the formulae shown above and below, the groups R 1-13 , R 51 , R 52 , R Q , R, R 2A , R 2B , R IIIA , R 1N , R2N R B1 R B2 R CR1 R CR2 R or L represents an alkyl group, wherein one CH2group has been replaced by -CH=CH-, which can be linear or branched. It is preferably linear and has 2 to 10 C atoms. Thus, in particular, it represents 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; hept-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.

[0085] If, in the above and below indicated formulae, the group R 1-13 R 51 R 52 R Q R, R 2A R 2B R IIIA R 1N R 2N R B1 R B2 R CR1 R CR2 R or L represents an alkyl or alkenyl group, which is at least monosubstituted by halogen, this group is preferably linear and the halogen is preferably F or CI. In the case of multiple substitution, the halogen is preferably F. The resulting group also includes perfluorinated groups. In the case of monosubstitution, the fluorine or chlorine substituent can be in any desired position, but is preferably in the omega position.

[0086] Halogen is preferably F or CI, very preferably F.

[0087] The group -CR 0 =CR 00 is preferably -CH=CH-.

[0088] -CO-, -C(=O)- and -C(O)- represent a carbonyl group, i.e. .

[0089] Preferred substituents L are, for example, F, CI, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1-C(=0)R x -N(R x )2, linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms, in which one or more H atoms can optionally be replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, linear or branched alkenyl having 2 to 12 C atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15 C atoms,

[0090] in which R x denotes H, F, Cl, CN or linear, branched or cyclic alkyl having 1 to 25 C atoms, in which one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O- and / or S-atoms are not directly attached to one another, and in which one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-, and

[0091] Y 1 denotes halogen.

[0092] Particularly preferred substituents L are, for example, F, Cl, CN, NO2, CH3, C2H5, OCH3, OC2H5, SCH3, SC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, -CH=CH2, -CH2-CH=CH2, -CH=CH-CH3, -CH=CH-CH=CH2 or -C(CH3)=CH2.

[0093] Preferably L is , , or in which L has one of the above specified meanings.

[0094] The polymerizable group P is a group suitable for a polymerization reaction, for example a radical or ionic chain polymerization, an addition polymerization or a condensation polymerization, or for a polymer-analogous reaction, for example an addition or condensation on a polymer backbone. Particularly preferred are groups for chain polymerization, in particular those containing a C=C double bond or a -C≡C- triple bond, and groups suitable for ring-opening polymerization, for example oxetane or epoxy groups.

[0095] Preferred groups P are selected from the following groups

[0096] 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 W 3 -, HW 2 N-, HO-CW 2 W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si-, wherein W 1 denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W 2 and W 3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each, independently of one another, denote H, Cl or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is optionally substituted by one or more groups L, different from P-Sp-, as defined above, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.

[0097] Very preferred groups P are selected from the following groups:

[0098] ​​CH2=CW 1 -CO-O-, 1 -CO-, , , , CH2=CW 2 -O-, 2 -, 1 =CH-CO-(O) k3 -, 1 =CH-CO-NH-, 1 -CO-NH-, 1 -CO-NH-, k1 -Phe-(O) k2 -, k1 -Phe-(O) k2 -, 4 W 5 W 6 Si-, 1 denotes H, F, CI, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, CI or CH3, W 2 and W 3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each, independently of one another, denote CI, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each, independently of one another, denote H, CI or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.

[0099] Very particularly preferred groups P are selected from the groups CH2=CW 1 -CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, and CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-, and .

[0100] Further preferred polymerisable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluorinated acrylate, chlorinated acrylate, oxetane and epoxy, most preferred acrylate and methacrylate.

[0101] Very preferably, all polymerisable groups in the polymerisable compounds as used in the present application have the same meaning.

[0102] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X", such that each group P-Sp- corresponds to the formula P-Sp"-X"-, wherein

[0103] Sp" denotes a linear or branched alkylene group having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or poly-substituted by F, CI, Br, I or CN and wherein, in addition, one or more non-adjacent CH2 groups can each be replaced, independently of one another, by -O-, -S-, -NH-, -N(R 0 )-, -Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-, -O-CO-N(R 0 )-, -N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C-,

[0104] X" denotes -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-, -N(R 0 )-CO-, -N(R 0 )-CO-N(R 00 )-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -, -CY 2 =CY 3 -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond,

[0105] R 0 and R00 Each independently represents H or an alkyl group having 1-20 carbon atoms, and

[0106] Y 2 and Y 3 Each can be represented independently as H, F, Cl, or CN.

[0107] 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.

[0108] 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.

[0109] 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 has one of the meanings specified above.

[0110] 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.

[0111] In a preferred embodiment of the application, the compounds of the formulae IA and / or IB and the subformulae thereof contain a spacer group Sp which is substituted by one or more polymerisable groups P, so that the group Sp-P corresponds to Sp(P) s where s is > 2 (branched polymerisable groups).

[0112] The preferred compounds of the formulae IA and IB according to this preferred embodiment are those in which s is 2, i.e. compounds containing the group Sp(P)2. Very preferred compounds of the formulae IA and IB according to this preferred embodiment contain a group selected from the following formulae:

[0113]

[0114] where P is as defined in formula I,

[0115] alkyl denotes a single bond or a straight-chain or branched alkylene group having 1 -12 C atoms which is unsubstituted or mono- or poly-substituted by F, Cl or CN and in which one or more non-adjacent CH2groups can each be replaced, independently of one another, by -C(R 0 )=C(R 0 )-, -C≡C-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, where R 0 have the meanings indicated above,

[0116] aa and bb each, independently of one another, denote 0, 1, 2, 3, 4, 5 or 6,

[0117] X has one of the meanings indicated for X", and is preferably O, CO, SO2, O-CO-, CO-O or a single bond.

[0118] The preferred spacer groups Sp(P)2are selected from the formulae S1, S2 and S3.

[0119] The very preferred spacer groups Sp(P)2are selected from the following subformulae:

[0120]

[0121] P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluorinated acrylate, chlorinated acrylate, oxetane and epoxy, very preferably acrylate and methacrylate, most preferably methacrylate.

[0122] It is further preferred that all polymerisable groups P present in the same compound have the same meaning, and very preferably denote acrylate or methacrylate, most preferably methacrylate.

[0123] Sp preferably denotes a single bond or -(CH2) p1 - -(CH2) p2 -CH=CH-(CH2) p3 - -(CH2) p1 - -(CH2) p1 - -(CH2) p1 wherein pi is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 independently of each other are 0, 1, 2 or 3 and, if Sp is -O-(CH2) p1 - -(CH2) p1 - -(CH2) p1 then the O-atom or the CO-group, respectively, is attached to the phenyl ring.

[0124] In a preferred embodiment, in formula I and / or its subformulae at least one group Sp is a single bond.

[0125] In a very preferred embodiment, in formula I and / or its subformulae all groups Sp are single bonds.

[0126] In another preferred embodiment, in formula I and / or its subformulae at least one group Sp is a single bond and at least one group Sp is different from a single bond.

[0127] If a group Sp is different from a single bond, it is preferably selected from -(CH2) p1 - -(CH2) p2 -CH=CH-(CH2) p3 - -(CH2) p1 - -(CH2) p1 - -(CH2) p1 wherein pi is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 independently of each other are 0, 1, 2 or 3 and, if Sp is -O-(CH2) p1 - -(CH2) p1 - -(CH2) p1 then the O-atom or the CO-group, respectively, is attached to the phenyl ring. Very preferably, if Sp is different from a single bond, it is selected from -(CH2)2-, -(CH2)3-, -(CH2)4-, -O-(CH2)2-, -O-(CH2)3-, -O-CO-(CH2)2and -CO-O-(CH)2-, wherein the O-atom or the CO-group is attached to the phenyl ring.

[0128] Preferably, in the compounds of the formula I and the subformulae thereof, all polymerizable groups P have the same meaning and very preferably denote an acrylate or a methacrylate, most preferably a methacrylate.

[0129] Very preferably, the compounds of the formula I are selected from the following subformulae: a The compounds of the formula I in which R

[0130] Further preferred are the compounds of the formula I in which R a The compounds of the formula I in which R

[0131] Further preferred are the compounds of the formula I and the subformulae thereof in which r1 or r2 is > 0.

[0132] Further preferred are the compounds of the formula I and the subformulae thereof in which r1 or r2 is 0, 1 or 2, very preferably 1 or 2, most preferably 1.

[0133] R preferably denotes F, CI, CN, or a linear, branched or cyclic alkyl, alkoxy, thioalkyl, alkylcarbonyl or alkylcarbonyloxy group having 1 to 12, preferably 1 to 6 carbon atoms.

[0134] The compounds of the formula I are preferably selected from the following subformulae:

[0135]

[0136] in which P, Sp and L have the meanings given in the formula I or one of the preferred meanings given above and below, r1 is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 1 or 2, most preferably 1, and r2 is 0, 1, 2 or 3, very preferably 0 or 1.

[0137] Especially preferred are the compounds of the formula I-1.

[0138] Very preferably, the compounds of the formula I are selected from the following subformulae:

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] in which P and L have the meanings given in the formula I or one of the preferred meanings thereof given above and below, and Sp' has one of the meanings of Sp, which is different from a single bond.

[0145] Especially preferred are compounds of formulae 1-1-2 to 1-1-5, very preferred are compounds of formula 1-1-2.

[0146] Further preferred are compounds of formula I and the subformulae thereof selected from the following preferred embodiments (including any combination thereof):

[0147] - all groups P in the compound have the same meaning,

[0148] - all groups P in the compound represent methacrylate,

[0149] - the compound contains exactly two polymerizable groups (represented by groups P),

[0150] - the compound contains exactly three polymerizable groups (represented by groups P),

[0151] - P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate, most preferably methacrylate,

[0152] - all groups Sp represent a single bond,

[0153] - all groups Sp are different from a single bond,

[0154] - when different from a single bond, Sp is -(CH2) p2 -, -(CH2) p2 - O-, -(CH2) p2 - CO-O-, -(CH2) p2 - O-CO-, wherein p2 is 2, 3, 4, 5 or 6 and the O-atoms or CO-groups are each attached to a phenyl ring,

[0155] - L represents F, CI, CH3, C2H5, OCH3, OC2H5, SCH3, SC2H5, -C(=0)H, -C(=0)CH3, -C(=0)C2H5, very preferably F, OCH3, SCH3, -C(=0)H, -C(=0)CH3or -C(=0)C2H5, most preferably -C(=0)H or -C(=0)CH3or -C(=0)C2H5,

[0156] - r, r1 and r2 > 0,

[0157] - r and r1 represent 1.

[0158] Very preferred are compounds of formula I and the subformulae thereof of the following formulae:

[0159]

[0160]

[0161] Most preferred are compounds of formula Id, Ie, If and Ig, especially Ie and If.

[0162] In a preferred embodiment of the present application, the LC medium comprises only one compound of formula I or a subformula thereof. In another preferred embodiment, the LC medium comprises two or more compounds of formula I or a subformula thereof.

[0163] In another preferred embodiment, the LC medium does not comprise any polymerisable compounds other than compounds of formula I.

[0164] The total proportion of polymerisable compounds of formula I and subformulae thereof in the LC medium according to the present application is preferably 0.1 to 2.5 %, more preferably 0.1 to 1.0 %, very preferably 0.2 to 0.6 %, by weight.

[0165] The polymerisable compounds as described above and hereinafter can be prepared analogously to methods known to the person skilled in the art and described in standard works of organic chemistry, such as, for example, Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart, and by using the starting materials that are commercially available or readily synthesizable. For example, starting materials for compounds of formula I, such as 2,5-dihydroxybenzaldehyde, 2,5-dihydroxyacetophenone, 2,5-dihydroxypropiophenone or 2-tert-butylhydroquinone, are commercially available.

[0166] For example, acrylate or methacrylate esters can be prepared by esterification of the corresponding alcohol with an acid derivative, for example (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, esters can be prepared by esterification of the alcohol with (meth)acrylic acid in the presence of a dehydrating agent, for example dicyclohexylcarbodiimide (DCC) according to Steglich, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) or N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and DMAP.

[0167] The present application also relates to an LC medium or LC display as described above, wherein the polymerisable compounds are present in polymerized form.

[0168] The LC display is preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display.

[0169] For the production of PSA or polymer stabilised SA displays, the polymerisable compounds contained in the LC medium are polymerised by in situ polymerisation in the LC medium between the substrates of the LC display, preferably with simultaneous application of a voltage to the electrodes.

[0170] As described in the prior art cited in the introduction, the structure of the inventive display corresponds to the usual geometry of PSA displays. Preferred are geometries without protrusions, in particular those where the electrodes on the color filter side are unstructured and only the electrodes on the TFT side have slits. Particularly suitable and preferred electrode structures for PS-VA displays are described, for example, in US 2006 / 0066793 A1.

[0171] The preferred inventive PSA type LC display comprises

[0172] - a first substrate comprising pixel electrodes defining pixel areas, the pixel electrodes being connected to switching elements provided in each pixel area and optionally comprising a micro-slit pattern, and optionally a first alignment layer provided on the pixel electrodes,

[0173] - a second substrate comprising a common electrode layer, which can be provided on the entire portion of the second substrate facing the first substrate, and optionally a second alignment layer,

[0174] - an LC layer provided between the first and the second substrate and comprising an LC medium as described above and below, wherein the polymerizable compounds can also be present in polymerized form.

[0175] The first and / or the second alignment layer controls the alignment direction of the LC molecules of the LC layer. For example, in a PS-VA display, the alignment layer is chosen so as to impart a homeotropic (or vertical) alignment or an oblique alignment to the LC molecules. Such alignment layers can for example comprise a polyimide, which can also be rubbed, or can be prepared by a photo-alignment method.

[0176] The LC layer with the LC medium can be deposited between the substrates of the display by methods conventionally used by display manufacturers, for example by the so-called one-drop-filling (ODF) method. Then, the polymerizable components of the LC medium are polymerized, for example by UV light. The polymerization can be carried out in one step or in two or more steps.

[0177] The PSA display can comprise further elements, for example color filters, black matrix, passivation layers, optical retardation layers, transistor elements for addressing the individual pixels, etc., which are well known to the person skilled in the art and can be used without inventive skill.

[0178] The electrode structure can be designed by the skilled person depending on the respective display type. For example, for a PS-VA display, a multi-domain orientation of the LC molecules can be induced by providing electrodes with slits and / or protrusions or bumps to yield two, four or more different oblique alignment directions.

[0179] After polymerization, the polymerizable compounds form a copolymer, resulting in LC molecules in the LC medium having a certain tilt angle. Without wishing to be bound by a particular theory, it is believed that at least a portion of the cross-linked polymer formed from the polymerizable compounds will phase separate or precipitate from the LC medium and form a polymer layer on the substrate or electrode, or on an alignment layer disposed thereon. Microscopy data (e.g., SEM and AFM) has confirmed that at least a portion of the polymer formed accumulates at the LC / substrate interface.

[0180] The polymerization can be carried out in one step. It is also possible to first carry out the polymerization in a first step to produce a tilt angle, optionally while applying a voltage, and then polymerize or cross-link the compounds that were not reacted in the first step in a second polymerization step without applying a voltage (“final curing”).

[0181] Suitable and preferred polymerization methods are, for example, thermal polymerization or photopolymerization, preferably photopolymerization, in particular UV-induced photopolymerization, which can be achieved by exposing the polymerizable compounds to UV radiation.

[0182] A preferred method of preparing a PSA display comprises one or more of the following features (including any combination thereof):

[0183] - exposing the polymerizable medium in the display to UV light in a 2-step process comprising a first UV exposure step (“UV1 step”) in which a voltage is applied to produce a tilt angle, and a second UV exposure step (“UV2 step”) in which no voltage is applied to complete the polymerization,

[0184] - irradiating the polymerizable medium using a UV radiation source having an emission spectrum in the range of > 300 nm, preferably 300 to 380 nm, very preferably 300 to 360 nm, preferably at least in the UV2 step, more preferably in both the UV1 and UV2 steps,

[0185] - irradiating the polymerizable medium using a UV C-type lamp as the radiation source, preferably at least in the UV1 step, more preferably in both the UV1 and UV2 steps,

[0186] - irradiating the polymerizable medium using a UV C-type lamp in the UV1 step and a UV B-type lamp in the UV2 step as the UV radiation source.

[0187] A preferred embodiment of the present application relates to a method of preparing a PSA display as described hereinbefore and hereinafter comprising one or more of the following features (including any combination thereof):

[0188] - In a two-step process, the polymerizable LC medium is irradiated with UV light. This two-step process includes 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 polymerization is completed without applying a voltage.

[0189] - The polymerizable LC medium is passed through a medium with a strength of 0.5 mW / cm 2 Up to 10mW / cm 2 The UV light irradiation produced by a UV lamp of a certain intensity is preferably carried out in the UV2 step, and optionally also in the UV1 step.

[0190] - Irradiate the polymerizable LC medium with UV light having a wavelength preferably >300 nm.

[0191] -The polymerizable LC dielectric is irradiated with UV light while a voltage is applied to the electrodes of the display.

[0192] - Irradiation with UV light is performed using a UV C-type lamp, preferably at least in the UV2 step, more preferably in both the UV1 and UV2 steps.

[0193] - The process involves irradiation with UV light using a UV C-type lamp in the UV1 step and a UV B-type lamp in the UV2 step.

[0194] - Irradiation with UV light is performed using a UV-LED lamp, preferably at least in the UV2 step, and more preferably in both the UV1 and UV2 steps.

[0195] This preferred method can be carried out, for example, by using a desired UV lamp or by using a bandpass filter and / or a cutoff filter, which substantially transmits UV light having the respective desired wavelength and substantially blocks light having the respective undesired wavelength.

[0196] Preferably, UV C-type lamps are used for UV irradiation, preferably at least in the UV2 step, more preferably in both the UV1 and UV2 steps, or a C-type lamp is used in the UV1 step and a B-type lamp is used in the UV2 step.

[0197] The UV radiation energy is preferably in the range of 2 to 100 J, depending on the production process conditions.

[0198] The LC medium according to the 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.

[0199] The LC medium preferably has a nematic LC phase.

[0200] In a preferred embodiment, the LC medium comprises one or more polymerization initiators. Suitable polymerization conditions as well as suitable initiator types and amounts are known to the person skilled in the art and are described in the literature. Suitable for free-radical polymerization are, for example, the commercially available photoinitiators Irgacure 651®, Irgacure 184®, Irgacure 907®, Irgacure 369®or Darocure 1173®(Ciba AG). If a polymerization initiator is used, its proportion is preferably 0.001 to 5 wt%, particularly preferably 0.001 to 1 wt%.

[0201] The polymerizable compounds according to the application are also suitable for polymerization without an initiator, which has considerable advantages, for example, lower material costs, and in particular less contamination of the LC medium with possible residual amounts of initiator or its degradation products.

[0202] It is thus also possible to carry out the polymerization without the addition of an initiator. In a further preferred embodiment, the LC medium thus contains no polymerization initiators.

[0203] In a further preferred embodiment of the application, the LC medium contains one or more further stabilizers.

[0204] The preferred stabilizer is selected from the group consisting of compounds of the formula H

[0205]

[0206] wherein

[0207] Ar denotes an aromatic or heteroaromatic hydrocarbon radical having 4 to 40 C atoms, preferably 6 to 30 C atoms;

[0208] Sp denotes a spacer group;

[0209] R S denotes H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms;

[0210] Z S denotes -O-, -C(O)O-, -(CH2) z - or -(CH2) z O- or a single bond;

[0211] HA denotes ;

[0212] R H denotes H, O . , CH3, OH or OR S , preferably H or O. ;

[0213] R S1 , R S2 , R S3 and R S4 identically or differently, represent an alkyl group having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH3;

[0214] G represents H or R S or the group Z S -HA;

[0215] z is an integer from 1 to 6; and

[0216] q is 3 or 4.

[0217] Compounds of formula H are described in EP 3354710 A1 and EP 3354709 A1.

[0218] Preferably, the compounds of formula H are selected from the group consisting of formulae H-1, H-2 and H-3:

[0219]

[0220]

[0221] wherein R H have the meaning given above and preferably represent H or O . and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7, and Sp represents a spacer group, preferably an alkylene group having 1 to 12 C atoms, wherein one or more non-adjacent -CH2- groups can be replaced by -O-.

[0222] Preferably, the compounds of formula H-1 are those of formula H-1-1:

[0223]

[0224] wherein R H have the meaning given above and preferably represent H or O . and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0225] Very preferably, the compounds of formula H-1-1 are those of formula H-1-1-1:

[0226]

[0227] Preferably, the compounds of formula H-2 are those of formula H-2-1:

[0228]

[0229] wherein R H has the meaning given above and preferably denotes H or O . and n2, at each occurrence, identically or differently, preferably identically, is an integer from 1 to 12, preferably 2, 3, 4, 5 or 6, very preferably 3, and R S at each occurrence, identically or differently, preferably identically, denotes alkyl having 1 to 6 C atoms, preferably n-butyl.

[0230] Very preferred compounds of formula H-2-1 are those of formula H-2-1-1:

[0231]

[0232] Preferred compounds of formula H-3 are selected from formula H-3-1:

[0233]

[0234] wherein Sp and R H have the meaning given above and R H preferably denotes H or O . and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7.

[0235] Further preferred stabilizers are selected from the group consisting of formulae ST-1 to ST-18:

[0236]

[0237]

[0238]

[0239]

[0240] wherein

[0241] R ST denotes H, alkyl or alkoxy having 1 to 15 C atoms, where, in addition, one or more CH2groups can each be replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, -O-CO- such that the O atoms are not directly connected to one another, and where, in addition, one or more H atoms can be replaced by halogen,

[0242] at each occurrence, identically or differently, denotes or ,

[0243] Z ST each, independently of one another, denotes -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,

[0244] L 1 and L 2 each, independently of one another, denotes F, CI, CH3, CF3or CHF2,

[0245] p denotes 0, 1 or 2,

[0246] q denotes 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0247] Preferred compounds of formula ST are those selected from formula ST-3 and in particular:

[0248]

[0249]

[0250]

[0251]

[0252] In the compounds of formula ST-3a and ST-3b, n preferably denotes 3. In the compounds of formula ST-2a, n preferably denotes 7.

[0253] Very preferred stabilizers are selected from the group of compounds of formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-3d, ST-3e, ST-8-1, ST-9-1 and ST-12:

[0254]

[0255]

[0256] In another preferred embodiment, the LC medium comprises one or more stabilizers selected from the following table D.

[0257] Preferably, the proportion of stabilizer in the LC medium is 10 to 500 ppm, very preferably 20 to 100 ppm.

[0258] In another preferred embodiment, the LC medium of the present application contains a self-alignment (SA) additive, preferably in a concentration of 0.1 - 2.5%.

[0259] In a preferred embodiment, the inventive SA-VA display 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.

[0260] Preferred SA additives for this preferred embodiment are selected from compounds comprising a mesogenic group and linear or branched alkyl side chains terminated by one or more polar anchoring groups selected from a hydroxyl, a carboxyl, an amino or a thiol group.

[0261] Further preferred SA additives contain one or more polymerisable groups, which are optionally connected to the mesogenic group via a spacer group. These polymerisable SA additives can be polymerised in the LC medium under similar conditions as used for the RMs in the PSA process.

[0262] Suitable SA additives for inducing vertical alignment, in particular 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.

[0263] In another preferred embodiment, the inventive LC medium or polymer stabilised SA-VA display contains one or more self-alignment additives selected from Table F below.

[0264] In another preferred embodiment, the LC medium according to the present application contains one or more SA additives, preferably selected from formula II or its subformulae or from Table F, in a concentration of 0.1 to 5 %, very preferably 0.2 to 3 %, most preferably 0.2 to 1.5 %.

[0265] In addition to the above polymerisable compounds and additives, the LC medium for use in the inventive LC display comprises an LC mixture ("host mixture") comprising one or more, preferably two or more, LC compounds selected from non-polymerisable low molecular weight compounds, wherein at least one is a compound of formula II. These LC compounds are selected such that they are stable and / or unreactive towards the polymerisation reaction under the polymerisation conditions applied to the polymerisable compounds.

[0266] A particularly preferred embodiment of such LC medium is shown below.

[0267] The LC medium or LC host mixture preferably comprises one or more compounds of formula II:

[0268]

[0269] wherein each radical, independently of one another and on each occurrence, has the following meanings identically or differently

[0270] R 21 , R 22 is H, linear, branched or cyclic alkyl or alkoxy having 1 to 20 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -, -C≡C-, , , , , or , and wherein one or more H atoms are each optionally replaced by F, Cl, CN or CF3, preferably the alkyl or alkoxy group has 1 to 6 C atoms,

[0271] R 0 , R 00 is H or alkyl having 1 to 12 C atoms,

[0272] A 1 , A 2 is a radical selected from the following formulae:

[0273]

[0274]

[0275] preferably from formulae A1, A2, A3, A4, A5, A6, A9 and A10, very preferably from formulae A1, A2, A3, A4, A5, A9 and A10,

[0276] Z 1 , Z 2 is -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O- or a single bond, preferably a single bond,

[0277] L 1 , L 2 , L 3 , L 4 is F, Cl, OCF3, CF3, CH3, CH2F or CHF2, preferably F or Cl, very preferably F,

[0278] Y is H, F, CI, CF3, CHF2or CH3, preferably H or CH3, very preferably H,

[0279] L C is CH3or OCH3, preferably CH3,

[0280] a1is 0, 1 or 2,

[0281] a2is 0 or 1.

[0282] Preferably, the LC medium contains one or more compounds of formula II selected from the group consisting of compounds of formulae IIA, IIB, IIC and IID

[0283]

[0284] wherein each group, on each occurrence, identically or differently and each independently of each other, has the following meanings:

[0285] R 21 , R 22 is H, alkyl, alkoxy or alkenyl having up to 15 C atoms, which is unsubstituted or mono- to per- substituted by F, CI, CN or CF3and furthermore in which one or more CH2groups in these radicals can be replaced, without the CH group directly adjacent to the CH group being replaced also, by -O-, -S-, -C=C-, -CF2O-, -OCF2-, -OC- O, -O-CO-, -CO-O, -CH=NR1-, -NR1-CO-, -CO-NR1-, -CY=CY- or -CY=CY-CY- with C and Y each being identical or different and being H, F, CI or CN, and furthermore in which H atoms, apart from the H atoms directly bonded to the N atom, can be replaced by F or CI, , , , , instead of,

[0286] L 1 to L 4 is F, CI, CF3or CHF2,

[0287] Y is H, F, CI, CF3, CHF2or CH3, preferably H or CH3, very preferably H,

[0288] Z 1 , Z 2 is a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O-, -CH2CH2O-, -OCH2CH2O-, -CH2OCH2O-, -OCH2CH2CH2O-, -CH2OCH2CH2O-, -CH2CH2OCH2O-, -CH2OCH2OCH2O-, -OCH2OCH2OCH2O-, -CH2O-, -OCH2O-, -O-, -CH2-, -CH=CH-CH2-, -CH2-CH=CH-,

[0289] p is 0, 1 or 2, and

[0290] q is 0 or 1.

[0291] Preferably, the compounds of formulae IIA, IIB, IIC and IID are those in which R 22represents alkyl or alkoxy having up to 15 C atoms, and very preferably represents (O)C v H 2v+1 wherein (O) is an oxygen atom or a single bond and v is 1, 2, 3, 4, 5 or 6.

[0292] Further preferred compounds of formula IIA, IIB, IIC and IID are those wherein R 21 or R 22 represents or contains cycloalkyl or cycloalkoxy, preferably selected from the group consisting of wherein S 1 is C 1-12 -alkylene or C 2-12 -alkenylene and S 2 is H, C 1-12 -alkyl or C 2-12 -alkenyl, and very preferably selected from the group consisting of

[0293]

[0294]

[0295] The following specifies further preferred compounds of formula IIA, IIB, IIC and IID.

[0296] In preferred embodiments, the LC medium comprises one or more compounds of formula IIA selected from the group consisting of the following formulae:

[0297]

[0298] ​wherein the index a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes 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-.

[0299] Particularly preferred LC media according to the present application comprise one or more compounds selected from the group consisting of formulae IIA-2, IIA-8, IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42 and IIA-43.

[0300] Preferably, the LC medium comprises one or more compounds of formula IIA-2 selected from the following subformulae:

[0301]

[0302] Alternatively, preferably in addition to compounds of formulae IIA-2-1 to IIA-2-5, the LC medium comprises one or more compounds of the following formulae:

[0303]

[0304] Further preferably, the LC medium comprises one or more compounds of formula IIA-10 selected from the following subformulae:

[0305]

[0306] Alternatively, preferably in addition to compounds of formulae IIA-10-1 to IIA-10-5, the LC medium comprises one or more compounds of the following formulae:

[0307]

[0308] In another preferred embodiment, the LC medium comprises one or more compounds of formula IIB selected from the group consisting of the following formulae:

[0309]

[0310] wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes 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-.

[0311] Particularly preferred LC media according to the present application comprise one or more compounds selected from the group consisting of formulae IIB-2, IIB-10 and IIB-16.

[0312] Preferably, the LC medium comprises one or more compounds of formula IIB-10 selected from the following subformulae:

[0313]

[0314] Alternatively, preferably in addition to compounds of formulae IIB-10-1 to IIB-10-5, the LC medium comprises one or more compounds of formulae IIB-10a-1 to IIB-10a-5:

[0315]

[0316] The proportion of compounds of formulae IIA and / or IIB in the mixture as a whole is preferably at least 20% by weight.

[0317] In a further preferred embodiment, the LC medium comprises one or more compounds of formula IIC selected from formula IIC-1:

[0318]

[0319] wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, preferably in an amount of 0.5 to 5% by weight, in particular 1 to 3% by weight.

[0320] In a further preferred embodiment, the LC medium comprises one or more compounds of formula IID selected from the group consisting of the following formulae:

[0321]

[0322] wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes 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-, alkyl can also be monofluorinated, and cycloalkyl and cylcoalkyl* independently of one another denote a cycloalkyl radical having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, very preferably selected from the group consisting of:

[0323]

[0324] Particularly preferred LC media according to the application comprise one or more compounds selected from formulae IID-4, IID-7, IID-13 and IID-19.

[0325] Very preferred compounds of formula IID are selected from the following subformulae:

[0326]

[0327] wherein v is 1, 2, 3, 4, 5 or 6.

[0328] Further preferred compounds of formula IID are selected from the following subformulae:

[0329]

[0330] wherein v is 1, 2, 3, 4, 5 or 6.

[0331] Further preferred compounds of formula IID are selected from the following subformulae:

[0332]

[0333] wherein v is 1, 2, 3, 4, 5 or 6.

[0334] Further preferred compounds of formula IID are selected from the following subformulae:

[0335]

[0336] wherein v is 1, 2, 3, 4, 5 or 6.

[0337] In another preferred embodiment, the LC medium comprises one or more compounds of formula IIE selected from the group consisting of

[0338]

[0339] wherein the index a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes 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-.

[0340] Particularly preferred LC media according to the present application comprise one or more compounds selected from the group consisting of formulae IIE-2, IIE-8, IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39 and IIE-40.

[0341] Particularly preferred LC media according to the present application comprise one or more compounds selected from the group consisting of formulae IIA-2, IIA-8, IIA-10, IIA-16, IIA-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1, IID-4, IID-10, IID-14, IID-17, IIE-2, IIE-8, IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39 and IIE-40 or a subformula thereof.

[0342] In another preferred embodiment, the LC medium comprises one or more compounds of formula III, which are different from formula IA,

[0343]

[0344] wherein each radical, independently of each other and on each occurrence, identically or differently, has the following meanings

[0345] R 31 , R 32 is H, alkyl, alkoxy or alkenyl having up to 15 C atoms which is unsubstituted, mono- or di-substituted by F, Cl, CN or CF3, furthermore in which one or more CH2 groups of these radicals can be replaced, without the CH2 groups directly adjacent to each other being replaced by O atoms, by -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC- O- or -O-CO-,

[0346] A 3 is a) 1,4-cyclohexenylene or 1,4-cyclohexylene, wherein one or two non-adjacent CH2 groups can be replaced by -O- or -S-,

[0347] b) 1,4-phenylene, wherein one or two CH groups can be replaced by N, or

[0348] c) a radical selected from the group consisting of spiro[3.3]heptane-2,6-diyl, 1,4- bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4- tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl,

[0349] wherein the groups a), b) and c) can be mono- or polysubstituted by halogen atoms,

[0350] n is 0, 1 or 2, preferably 0 or 1,

[0351] Z 1 -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,

[0352] L 11 , L 12 is F, CI, CF3or CHF2, preferably H or F, most preferably F,

[0353] W is O or S,

[0354] Y 1 , Y 2 is H, F, CI, CF3, CHF2, CH3or OCH3, preferably H, CH3or OCH3, very preferably H.

[0355] In the compounds of formula III, R 31 and R 32 are preferably selected from linear alkyl or alkoxy groups having 1 to 12, preferably 1 to 7 C atoms, linear alkenyl groups having 2 to 12, preferably 2 to 7 C atoms and cyclic alkyl or cycloalkoxy groups having 3 to 12, preferably 3 to 8 C atoms.

[0356] In a preferred embodiment of the present application, the LC medium comprises one or more compounds of formula III-1 or III-2

[0357]

[0358] wherein the groups occurring have the same meaning as given under formula III above and preferably

[0359] R 31 and R 32 are each, independently of one another, alkyl, alkenyl or alkoxy having up to 15 C atoms, more preferably one or both of them represents alkoxy and

[0360] L 11 and L 12 each preferably represent F.

[0361] In another preferred embodiment, the LC medium comprises one or more compounds of formula III-1 selected from the group of compounds of formulae III-1-1 to III-1-10, preferably of formula III-1-6,

[0362]

[0363] ,

[0364] wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy group having 1 to 6 C atoms, and L 11 and L 12 each, independently of one another, denote F or CI, preferably both are F.

[0365] In another preferred embodiment, the LC medium comprises one or more compounds of formula III-2 selected from the group of compounds of formulae III-2-1 to III-2-10, preferably of formula III-2-1,

[0366]

[0367]

[0368]

[0369] wherein alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl group having 1 to 6 C atoms, alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl group having 2 to 6 C atoms, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy group having 1 to 6 C atoms, and L 11 and L 12 each, independently of one another, denote F or CI, preferably both are F.

[0370] Very preferably, the compounds of formula III-2 are selected from the group consisting of the following subformulae:

[0371]

[0372] wherein alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy.

[0373] Very preferably, the compounds of formula III-2-1-3, III-2-1-4 and III-2-1-5.

[0374] In another preferred embodiment of the present application, the LC medium comprises one or more compounds of formula III-3-1 or III-3-2

[0375]

[0376] wherein L 11 and L 12 have the same meaning as given under formula III, (O) denotes O or a single bond,

[0377] R 33 denotes alkyl or alkenyl having up to 7 C atoms or the group Cy-C m H 2m+1 -,

[0378] R 34 denotes alkyl or alkenyl having up to 7 C atoms or the group Cy-C m H 2m+1 -,

[0379] m and n are identically or differently 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, and

[0380] Cy denotes a cycloaliphatic radical having 3, 4 or 5 ring atoms, which is optionally substituted by alkyl or alkenyl each having up to 3 C atoms, or by halogen or CN, and preferably denotes cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl.

[0381] Instead of or in addition to compounds of formula III, preferably in addition to compounds of formula III, compounds of formula III-3-1 and / or III-3-2 are comprised in the LC medium.

[0382] Very preferred compounds of formula III-3-1 are the following:

[0383]

[0384] wherein alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms.

[0385] Very preferred compounds of formula III-3-2 are the following:

[0386]

[0387] wherein alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms.

[0388] Very preferred compounds of formula III-3-3 are the following:

[0389]

[0390] wherein alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy.

[0391] Very preferred compounds of formula III3-4 are the following:

[0392]

[0393] wherein alkoxy denotes a straight-chain alkoxy group having 1 to 6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferably ethoxy or propoxy.

[0394] In another preferred embodiment of the present application, the LC medium comprises one or more compounds of formulae III-4 to III-6, preferably of formula III-5

[0395]

[0396] wherein the parameters have the meaning given above, R 11 preferably denotes a straight-chain alkyl group and R 12 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0397] In another preferred embodiment, the LC medium comprises one or more compounds of formula III selected from the group of compounds of formulae III-7 to III-9, preferably of formula III-8,

[0398]

[0399] wherein the parameters have the meaning given above, R 11 preferably denotes a straight-chain alkyl group and R 12 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0400] In a preferred embodiment of the present application, the LC medium comprises one or more compounds of formula III-10:

[0401]

[0402] wherein the groups occurring have the same meaning as given under formula III and preferably

[0403] R 31 and R 32each independently is alkyl, alkenyl or alkoxy having up to 15 C atoms, preferably having 1 to 7 C atoms, or cycloalkyl having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, very preferably selected from the group consisting of:

[0404]

[0405] Very preferred compounds of formula III-10 are selected from the group consisting of the following formulae:

[0406]

[0407] wherein R 32 represents alkyl having 1 to 7 C atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl, or alternatively -(CH2) n F, wherein n is 2, 3, 4 or 5, preferably C2H4F.

[0408] Preferred compounds of formula III are III-2-1-3, III-2-1-4, III-2-1-5 and III-10-2, wherein the most preferred compounds are B(S)-2O-O4, B(S)-2O-O5, B(S)-2O-O6 and COB(S)-2-O4.

[0409] In preferred embodiments, the LC medium comprises one or more compounds of formula IV

[0410]

[0411] wherein

[0412] R 41 represents unsubstituted alkyl having 1 to 7 C atoms, further wherein one or more CH2groups can be replaced by or unsubstituted alkenyl having 2 to 7 C atoms, preferably n-alkenyl, particularly preferably having 2, 3, 4 or 5 C atoms, and

[0413] R 42 represents unsubstituted alkyl having 1 to 7 C atoms or unsubstituted alkoxy having 1 to 6 C atoms (both preferably having 2 to 5 C atoms), unsubstituted alkenyl having 2 to 7 C atoms (preferably having 2, 3 or 4 C atoms), more preferably ethenyl or 1-propenyl and in particular ethenyl.

[0414] The compounds of formula IV are preferably selected from the group of compounds of formulae IV-1 to IV-5

[0415]

[0416] wherein

[0417] alkyl and alkyl’ independently of one another denote alkyl having 1 to 7 C atoms, preferably having 2 to 5 C atoms,

[0418] alkenyl denotes alkenyl having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably 2 C atoms,

[0419] alkenyl’ denotes alkenyl having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms,

[0420] alkoxy denotes alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms, and

[0421] cycloalkyl denotes cycloalkyl having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, very preferably selected from the group consisting of

[0422]

[0423] Preferably, the LC medium comprises one or more compounds of formula IV-1 selected from the following subformulae:

[0424]

[0425] Further preferably, the LC medium according to the present application comprises one or more compounds of formula IV-2-1 and / or IV-2-2

[0426]

[0427] Further preferably, the LC medium according to the present application comprises one or more compounds of formula IV-3, in particular selected from the following subformulae:

[0428]

[0429] In another preferred embodiment, the LC medium according to the present application comprises one or more compounds of formula IV-5 selected from the following subformulae:

[0430]

[0431] wherein alkyl denotes methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl or n-pentyl.

[0432] Further preferably, the LC medium according to the present application comprises one or more compounds of formula IV-4, in particular selected from the following subformulae:

[0433]

[0434] In another preferred embodiment, the LC medium comprises one or more compounds of formula IV-4 and the subformulae thereof, wherein one or both of "alkenyl" and "alkenyl'" denotes wherein m is 0, 1 or 2, and n is 0, 1 or 2, very preferably selected from the compounds of formulae IV-4-3 to IV-4-6.

[0435] Very preferably, the LC medium according to the present application comprises one or more compounds of formula IV-1 or the subformulae thereof and / or one or more compounds of formula IV-3 or the subformulae thereof and / or one or more compounds of formula IV-4 or the subformulae thereof, and / or one or more compounds of formula IV-5 or the subformulae thereof, wherein the total concentration of these compounds is in the range of 1 % to 30%.

[0436] The LC medium according to the present application preferably additionally comprises one or more compounds of formula IVa,

[0437]

[0438] wherein

[0439] R 41 and R 42 each, independently from one another, denotes a linear alkyl, alkoxy, alkenyl or alkoxyalkyl group having up to 12 C atoms,

[0440]

[0441] Z 4 denotes a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8- or -CF=CF-.

[0442] The following preferred compounds of formula IVa are specified:

[0443]

[0444] wherein alkyl and alkyl* each, independently from one another, denote a linear alkyl group having 1 to 6 C atoms.

[0445] The LC medium according to the present application preferably comprises at least one compound of formula IVa-1 and / or formula IVa-2.

[0446] The proportion of compounds of formula IVa in the mixture as a whole is preferably at least 5% by weight.

[0447] Preferably, the LC medium comprises one or more compounds of formula IVb-1 to IVb-3

[0448]

[0449] wherein

[0450] alkyl and alkyl* each, independently of one another, denote a linear alkyl radical having 1 to 6 C atoms, and

[0451] alkenyl and alkenyl* each, independently of one another, denote a linear alkenyl radical having 2 to 6 C atoms.

[0452] The proportion of compounds of formula IV-1 to IV-3 in the mixture as a whole is preferably at least 3% by weight, in particular > 5% by weight.

[0453] Of the compounds of formula IVb-1 to IVb-3, the compounds of formula IVb-2 are particularly preferred.

[0454] Particularly preferred compounds of formula IV-1 to IV-3 are selected from the group consisting of the following formulae:

[0455]

[0456] wherein alkyl* denotes an alkyl radical having 1 to 6 C atoms and preferably denotes n-propyl.

[0457] The LC medium according to the present application particularly preferably comprises one or more compounds of formula IVb-1-1 and / or IVb-2-3.

[0458] In a further preferred embodiment, the LC medium according to the present application comprises one or more compounds of formula V

[0459]

[0460] wherein

[0461] R 51 and R 52independently of one another H, alkyl having up to 15 C atoms, which is unsubstituted, mono- or di-substituted with F, CI, CN or CF3, and in which, in addition, one or more CH2 groups can be replaced, by -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC- O-, -O-CO-, -CO-O-, wherein at least one CH2 group is replaced by -O- or -S-, , , , , alternatively and preferably alkyl having 1 to 7 C atoms, preferably n-alkyl, particularly preferably n-alkyl having 1 to 5 C atoms, alkoxy having 1 to 6 C atoms, preferably n-alkoxy, particularly preferably n-alkoxy having 2 to 5 C atoms, alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 C atoms, preferably having 2 to 4 C atoms, preferably alkenyloxy,

[0462]

[0463] wherein

[0464]

[0465] Z 51 , Z 52 each, independently of one another, denotes -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, and

[0466] n is 1 or 2.

[0467] The compounds of the formula V are preferably selected from the group of the compounds of the formulae V-1 to V-17:

[0468]

[0469]

[0470] wherein R 1 and R 2 have the meanings indicated above for R 51 and R 52 .

[0471] R 1 and R 2 preferably each, independently of one another, denote linear alkyl or alkenyl.

[0472] Preferably the LC medium comprises one or more compounds of formulae V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15 and / or V-16.

[0473] The LC medium according to the present application very particularly preferably comprises compounds of formula V-10 and / or IV-1, in particular in an amount of 5 to 30%.

[0474] The following preferred compounds of formula V-10 are specified:

[0475]

[0476] The LC medium according to the present application particularly preferably comprises tricyclic compounds of formula V-10a and / or V-10b in combination with one or more bicyclic compounds of formula IV-1. The total proportion of the combination of compounds of formula V-10a and / or V-10b with one or more compounds selected from bicyclic hexyl compounds of formula IV-1 is 5 to 40%, very particularly preferably 15 to 35%.

[0477] Particularly preferred LC media comprise compounds V-10a and IV-1 -1 :

[0478]

[0479] The compounds V-10a and IV-1 -1 are preferably present in the mixture in a concentration of 5 to 30%, very preferably 10 to 25%, based on the mixture as a whole.

[0480] Preferably the LC medium comprises at least one compound selected from the group of the following compounds

[0481]

[0482] wherein R 1 , R 2 , R 41 and R 42 have the meanings specified above. Preferably, in the compounds V-6, V-7 and IV, R 1 and R 41 each denote alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms, and R 2 and R 42 denote alkenyl having 2 to 6 C atoms. Preferably, in the compound V-14, R 1 denotes alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms and R 2 denotes alkyl having 1 to 6 C atoms. Further preferably, in the compound V-7, R 1 and R 2One or two of them represent cycloalkyl groups having 3 to 12 carbon atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl, or cyclopentylalkyl.

[0483] In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula V-7, preferably selected from compounds of formulas V-7a to V-7e:

[0484]

[0485] Wherein alkyl represents an alkyl group having 1 to 7 carbon atoms, alkenyl represents an alkenyl group having 2 to 7 carbon atoms, and cycloalkyl represents a cycloalkyl group having 3 to 12 carbon atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl, or cyclopentylalkyl.

[0486] The highly preferred compounds V-7a to V-7e are selected from compounds of formulas V7-b1 to V7-b3, V-7d-1 to V-7d-8 and V-7e-1 to V-7e-12.

[0487]

[0488] Wherein alkyl represents ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl.

[0489] Another preferred compound is of formula V, wherein R 51 and R 52 Each can be independently represented as an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms.

[0490] In a preferred embodiment of the invention, the LC medium further comprises one or more compounds of formulas VI-1 to VI-25.

[0491]

[0492] in

[0493] R represents a straight-chain alkyl or alkoxy group with 1 to 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.

[0494] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, or pentoxy.

[0495] X preferably represents F or OCH3, and very preferably F.

[0496] The LC medium according to the invention preferably contains 2 to 30% by weight, particularly 5 to 20% by weight, of terphenyl of formula VI-1 to VI-25.

[0497] Particularly preferred are compounds of formulas VI-1, VI-2, VI-4, VI-20, VI-21, and VI-22, wherein X represents F. In these compounds, R preferably represents an alkyl group, and may also represent an alkoxy group, each having 1 to 5 carbon atoms. In compounds of formula VI-20, R preferably represents an alkyl or alkenyl group, particularly an alkyl group. In compounds of formula VI-21, R preferably represents an alkyl group. In compounds of formulas VI-22 to VI-25, X preferably represents F.

[0498] If the Δn value of the mixture is ≥0.1, then terphenyl compounds of formula VI-1 to VI-25 are preferably used in the LC medium according to the invention. Preferably, the LC medium contains 2 to 20% by weight of one or more terphenyl compounds selected from the group consisting of compounds of formula VI-1 to VI-25.

[0499] In another preferred embodiment of the invention, the LC medium further comprises one or more compounds of formulas VII-1 to VII-9.

[0500]

[0501]

[0502] in

[0503] R 1 Each of them independently possesses the characteristics of R in Equation IIA. 21 One of the specified meanings, and

[0504] w and x each represent 1 to 6 independently.

[0505] Particularly preferred are LC media containing at least one compound of formula VII-9.

[0506] LC media, comprising one or more substances containing tetrahydronaphthyl or naphthyl units, such as, for example, compounds of formulas N-1 to N-5.

[0507]

[0508] Where R 61 and R62 Each has its own independent characteristics targeting R. 21 The specified meaning preferably refers to a straight-chain alkyl, a straight-chain alkoxy, or a straight-chain alkenyl group, and

[0509] Z 61 and Z 62 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.

[0510] c) An LC medium comprising one or more compounds selected from the group consisting of difluorodibenzo-p-chromium compounds of formula BC, chromium compounds of formula CR, and fluorinated phenanthrene compounds of formulas PH-1 and PH-2.

[0511]

[0512] in

[0513] R 71 and R 72 Each has its own R independently 21 The meaning is that c is 0, 1, or 2. R 71 and R 72 Preferably, alkyl or alkoxy groups having 1 to 6 carbon atoms are represented independently of each other.

[0514] The LC medium according to the invention preferably contains 3 to 20% by weight, particularly 3 to 15% by weight, of a compound of the formula BC, CR, PH-1, PH-2.

[0515] Particularly preferred compounds of formulas BC and CR are compounds BC-1 to BC-7 and CR-1 to CR-5.

[0516]

[0517]

[0518] in

[0519] alkyl and alkyl* each independently represent straight-chain alkyl groups having 1 to 6 carbon atoms, and

[0520] alkenyl and alkenyl* each independently represent straight-chain alkenyl groups having 2 to 6 carbon atoms.

[0521] Very particularly preferred are LC media containing one, two or three compounds of the formula BC-2, BF-1 and / or BF-2.

[0522] d) An LC medium comprising one or more indene compounds of the formula In.

[0523]

[0524] in

[0525] R 81 R 82 R 83 Each of these terms independently represents a straight-chain alkyl, alkoxy, alkoxyalkyl, or alkenyl group having 1 to 6 carbon atoms.

[0526] R 82 and R 83 It can also represent halogen, preferably F.

[0527]

[0528] i represents 0, 1, or 2.

[0529] The preferred In compounds are those specified below as In-1 to In-16:

[0530]

[0531] Compounds of formulas In-1, In-2, In-3 and In-4 are particularly preferred.

[0532] In the LC medium according to the invention, compounds of the formula In and its sub-formulas In-1 to In-16 are preferably used at concentrations of ≥5% by weight, particularly 5 to 30% by weight and very particularly preferably 5 to 25% by weight.

[0533] e) An LC medium comprising one or more compounds of formulas L-1 to L-8,

[0534]

[0535] ,

[0536] in

[0537] R, R 1 and R 2 Each of them independently possesses the properties of R in Equation IIA above. 21 The specified meaning, where alkyl represents an alkyl group having 1 to 6 carbon atoms. The parameter s indicates 1 or 2.

[0538] Compounds of formula L-1 to L-8 are preferably used at a concentration of 5 to 15% by weight, particularly 5 to 12% by weight and very particularly preferably 8 to 10% by weight.

[0539] f) Preferably, the LC medium further comprises one or more compounds of formula IIA-Y.

[0540]

[0541] Where R 11 and R 12 Having the above formula IIA for R 21 One of the given meanings, and L 1 and L 2 F or Cl can be represented in the same or different ways.

[0542] The preferred compound IIA-Y is selected from the group consisting of the following formulas.

[0543]

[0544]

[0545] Alkyl and Alkyl* each independently represent a straight-chain alkyl group having 1 to 6 carbon atoms, Alkoxy represents a straight-chain alkoxy group having 1 to 6 carbon atoms, Alkenyl and Alkenyl* each independently represent a straight-chain alkenyl group having 2 to 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-.

[0546] The particularly preferred compounds of formula IIA-Y are selected from the group consisting of the following formulas:

[0547]

[0548] Alkoxy and Alkoxy* have the meanings defined above and preferably represent methoxy, ethoxy, propoxy, butoxy, or pentoxy.

[0549] g) An LC medium comprising one or more tetraphenyl compounds selected from the following formula:

[0550]

[0551] in

[0552] R Q It is an alkyl, alkoxy, oxalyl, or alkoxyalkyl group having 1 to 9 carbon atoms, or an alkenyl or alkenoxy group having 2 to 9 carbon atoms, all of which are optionally fluorinated.

[0553] X Q It is F, Cl, a haloalkyl or alkoxy group having 1 to 6 carbon atoms, or a haloalkenyl or alkenoxy group having 2 to 6 carbon atoms.

[0554] L Q1 To L Q6 Each is independent of the other, either H or F, where L Q1 To L Q6 At least one of them is F.

[0555] The preferred compound Q is wherein R Q It refers to a straight-chain alkyl group having 2 to 6 carbon atoms, very preferably those that are ethyl, n-propyl, or n-butyl.

[0556] The preferred compound Q is wherein L Q3 and L Q4 Those that are F. Additionally, the preferred compound Q is in which L... Q3 L Q4 and L Q1 and L Q2 Those in which one or both are F.

[0557] The preferred compound Q is wherein X Q It represents F or OCF3, with those of F being very preferred.

[0558] Compound Q is preferably selected from the following sub-formulas.

[0559]

[0560] Where R Q It has one of the meanings of formula Q or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl.

[0561] Compounds of formula Q1 are particularly preferred, especially those containing R. Q Those that are n-propyl.

[0562] Preferably, the proportion of compound Q in the LC medium is >0 to ≤5% by weight, very preferably 0.05 to 2% by weight, more preferably 0.1 to 1% by weight, and most preferably 0.1 to 0.8% by weight.

[0563] Preferably, the LC medium contains 1 to 5, more preferably 1 or 2, compounds of formula Q.

[0564] Adding tetraphenyl compounds of formula Q to polymerizable LC media mixtures reduces ODF inhomogeneity while maintaining high UV absorption, enables rapid and complete polymerization, allows for strong and rapid generation of tilt angles, and increases the UV stability of LC media.

[0565] Furthermore, adding a Q-type compound with positive dielectric anisotropy to an LC dielectric with negative dielectric anisotropy allows for better control over the dielectric constant ε. ‖ and ε ⊥ The value of ε, and in particular, enables the achievement of a high dielectric constant ε. ‖ The value is maintained while preserving the dielectric anisotropy Δε constant, thereby reducing kickback voltage and image residue.

[0566] The LC medium according to the present invention preferably contains

[0567] - Preferably, one or more compounds of formula II or its sub-formulas, preferably compounds of formula IIA and / or IIB, in a total concentration ranging from 30% to 65%, more preferably from 35% to 60%, and particularly preferably from 40% to 55%;

[0568] and / or

[0569] - Preferably, one or more Formula IV compounds in a total concentration ranging from 35% to 60%, more preferably from 40% to 55%, and particularly preferably from 45% to 50%;

[0570] and / or

[0571] - Preferably, one or more compounds of formula III, preferably of formula III-2, and most preferably of formula III-2-1 and / or III-10-2, in a total concentration ranging from 2% to 25%, and very preferably from 4% to 15%.

[0572] and / or

[0573] - Preferably, one or more compounds of formula V or its sub-formulas, preferably compounds of formula V-9, in a total concentration ranging from 0.1% to 30%, more preferably from 0.25% to 25%, and particularly preferably from 0.5% to 20%;

[0574] Specifically, the LC medium contains

[0575] - Preferably, one or more compounds CY-n-Om, particularly CY-3-O4, CY-5-O4 and / or CY-3-O2, are present in a total concentration of 5% to 30%, preferably 10% to 20%, based on the mixture as a whole;

[0576] and / or

[0577] - Preferably, one or more compounds PY-n-Om, particularly PY-1-O2, PY-2-O2 and / or PY-3-O2, are present in a total concentration ranging from 5% to 40%, preferably from 10% to 30%, based on the mixture as a whole;

[0578] and / or

[0579] - Preferably, based on a concentration of >5%, particularly 7% to 20%, of one or more compounds CPY-n-Om, especially CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, in the mixture as a whole.

[0580] and / or

[0581] - Preferably, based on a concentration of >3%, particularly 5 to 15%, of 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, when the mixture is as a whole;

[0582] and / or

[0583] - Preferably, one or more compounds CPY-n-Om and CY-n-Om are present at a concentration of 10% to 80% based on the mixture as a whole.

[0584] and / or

[0585] - Preferably, based on a concentration of 5 to 20%, more preferably 10 to 15%, of one or more compounds CPY-n-Om and PY-n-Om, preferably CPY-2-O2 and / or CPY-3-O2 and PY-3-O2 or PY-1-O2, of the mixture as a whole.

[0586] and / or

[0587] Preferably, the total concentration of Y-nO-Om, CCY-n-Om, LY-n-Om and / or CLY-n-Om, particularly Y-4O-O4, CCY-3-O1, CCY-3-O2, CCY-3-O3, CLY-2-O4, CLY-3-O2, CLY-3-O3, CLY-4-O2 and / or CLY-5-O2, is 30% to 65%, more preferably 35% to 60%, based on the mixture as a whole.

[0588] and / or

[0589] Preferably, the total concentration of one or more compounds CC-nV, particularly CC-3-V, ranges from 20% to 60%, more preferably from 25% to 50%, and most preferably from 35% to 45%.

[0590] and / or

[0591] - Preferably, based on a total concentration of 3% to 40%, more preferably 3% to 25%, of one or more compounds selected from the group consisting of CCH-13, CCH-23, CCH-34, CCH-35, CCH-301 and CCH-303, the mixture as a whole.

[0592] and / or

[0593] - Preferably, based on a total concentration of 3% to 40%, more preferably 5% to 30%, of one or more compounds selected from the group consisting of CC-2-V1, CC-3-V1, CC-3-V2, CC-4-V1, CC-3-V, CC-4-V, and CC-5-V.

[0594] and / or

[0595] - Preferably, based on a total concentration of 4% to 35%, preferably 5% to 25% of the mixture as a whole, one or more compounds CCP-nm and / or CCP-Vn-m and / or CPP-nm, preferably selected from the group consisting of CCP-3-1, CCP-V-1, CCP-V2-1 and CPP-3-2,

[0596] and / or

[0597] - Preferably, one or more compounds CLP-nm and / or CLP-Vn-m are present at a total concentration of 1% to 25%, preferably 2% to 15%, based on the mixture as a whole, and preferably selected from the group consisting of CLP-3-1, CLP-3-2 and CLP-V-1.

[0598] and / or

[0599] - Preferably, based on a total concentration of 2% to 20%, more preferably 2% to 15%, and most preferably 2% to 10% of the mixture as a whole, one or more compounds selected from the group consisting of PYP-nm, PGIY-n-Om, and PGP-n-2V.

[0600] and / or

[0601] - Preferably, based on a total concentration of 1% to 15%, preferably 2% to 10%, of one or more compounds PP-nm and / or PP-n-nVm, as a mixture as a whole, preferably selected from the group consisting of PP-1-3, PP-1-4, PP-1-5, PP-1-2V, and PP-1-2V1,

[0602] and / or

[0603] - Preferably, the concentration of compound PPGU-3-F is 0.1% to 3% based on the mixture as a whole.

[0604] The present invention further relates to an electro-optic display with active matrix addressing, characterized in that it contains an LC medium as a dielectric according to claim 1, 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.

[0605] Advantageous for the LC 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.

[0606] The medium of the present invention has a clearing temperature of 70°C or higher, preferably 74°C or higher.

[0607] 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.

[0608] The liquid crystal mixture preferably has a nematic phase range of at least 60 K and a maximum of 30 mm at 20 °C. 2 ·s -1 Flow viscosity ν 20 .

[0609] The mixture is nematic at -20°C or lower, preferably -30°C or lower, and very preferably -40°C or lower.

[0610] 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.

[0611] 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.

[0612] 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.

[0613] 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.

[0614] The rotational viscosity γ1 at 20°C is preferably ≤120 mPa·s, and especially ≤100 mPa·s.

[0615] In a preferred embodiment, the rotational viscosity γ1 at 20°C is ≤100 mPa·s, particularly ≤95 mPa·s.

[0616] The liquid crystal media of the present invention have relatively low threshold voltage (V0) values. They are preferably 1.7 V to 3.0 V, particularly preferably ≤2.7 V, and very particularly preferably ≤2.5 V.

[0617] 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.

[0618] Furthermore, the liquid crystal medium according to the present invention has a high voltage retention rate in the liquid crystal cell.

[0619] 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.

[0620] 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 an LC 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.

[0621] All temperature values ​​described in this invention are in °C.

[0622] 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.

[0623] 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.

[0624] 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.

[0625] The proportion of component A is preferably 45-100%, especially 60-85%.

[0626] 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.

[0627] 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 25 mm 2 · s -1 .

[0628] Many suitable materials are known to those skilled in the art from the literature.

[0629] 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 12 mm 2 · s -1 .

[0630] 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.

[0631] 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.

[0632] In addition to one or more polymerizable compounds, the medium preferably contains 4-15, particularly 5-12, and especially preferably <10 compounds of formula IIA, IIB and / or IIC, and optionally one or more compounds of formula IV-1 and / or III-2.

[0633] In addition to polymerizable compounds and compounds of formulas II, III and optional IV, 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%.

[0634] 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 acid esters.

[0635] The most important compound suitable as a component of this type of liquid crystal phase can be characterized by the following formula R.

[0636] R R1 LGER R2 R

[0637] 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.

[0638]

[0639] Or a CC single bond, Q refers to halogen, preferably chlorine or -CN, and R R1 and R R2Each 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.

[0640] In most of these compounds, R R1 and R R2 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.

[0641] It will be self-evident to those skilled in the art that the LC medium mixture according to the present invention may also contain compounds in which, for example, H, N, O, Cl and F are substituted with corresponding isotopes.

[0642] 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.

[0643] The LC medium of this invention may also contain other additives known to those skilled in the art and described in the literature, such as polymerization initiators, inhibitors, stabilizers, surfactants, or chiral dopants. These may 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.

[0644] 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, 22 40864, ​​23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

[0645] 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.

[0646] 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.

[0647] 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.

[0648] The following examples illustrate the invention but do not limit it. However, they demonstrate to those skilled in the art the preferred mixture concept, the preferred compounds used and their respective concentrations, and combinations thereof. Furthermore, the examples clarify which properties and combinations of properties are available.

[0649] In connection with this invention and in the following embodiments, the structures of the liquid crystal compounds are indicated by acronyms. Unless otherwise specified, conversions to chemical formulas are performed according to Tables A.1 to A.3 below. All groups C n H 2n+1 C m H 2m+1 and C l H 2l+1 Or C n H 2n C m H 2m and C l H 2lThe carbon atom is a straight-chain alkyl or alkenyl group, having n, m, or l carbon atoms in each case. Preferably, n, m, and l are 1, 2, 3, 4, 5, 6, or 7 independently of each other. Table A.1 shows the codes for the ring elements used in the core of the compound, Table A.2 lists the bridging units, and Table A.3 lists the meanings of the symbols for the left-hand and right-hand end groups of the molecule. The acronym consists of the code for the ring element with an optional linking group, followed by a first hyphen and the code for the left-hand end group, and a second hyphen and the code for the right-hand end group.

[0650] Table A.1: Ring Elements

[0651]

[0652]

[0653]

[0654]

[0655] Table A.2: Bridging Units

[0656]

[0657] Table A.3: End bases

[0658]

[0659]

[0660] Where n and m are integers, and the three dots “…” are placeholders for other abbreviations from this table.

[0661] Table B shows the illustrative structures of the compounds along with their respective abbreviations.

[0662] Table B

[0663] In Table B, n, m, k, and l are each an independent integer, preferably 1 to 9, more preferably 1 to 7. k and l can also be 0, preferably 0 to 4, more preferably 0 or 2, and most preferably 2. n is preferably 1, 2, 3, 4, or 5, or in the combination "-nO-", n is preferably 1, 2, 3, or 4, very preferably 2 or 4. m is preferably 1, 2, 3, 4, or 5, or in the combination "-Om", m is preferably 1, 2, 3, or 4, more preferably 2 or 4. The combination "-nVm" is preferably "2V1". (O)C m H 2m+1 Meaning C m H 2m+1 or OC m H 2m+1 .

[0664]

[0665] In a preferred embodiment of the invention, the LC medium according to the invention comprises one or more compounds selected from the group consisting of compounds from Table B.

[0666] Table C

[0667] Table C shows possible chiral dopants that can be added to the LC medium according to the present invention.

[0668]

[0669] The LC medium preferably contains 0 to 10% by weight, particularly 0.01 to 5% by weight, and especially preferably 0.1 to 3% by weight of dopant. The LC medium preferably contains one or more dopants selected from the group consisting of compounds derived from Table C.

[0670] Table D

[0671] Table D shows possible stabilizers that can be added to the LC media according to the invention. Wherein n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7, or 8, and terminal methyl groups are not shown.

[0672]

[0673] The LC medium preferably contains 0 to 10% by weight, particularly 1 to 5% by weight, and especially preferably 1 to 1% by weight of a stabilizer. The LC medium preferably contains one or more stabilizers selected from the group consisting of compounds derived from Table D.

[0674] Table E

[0675] Table E shows illustrative reactive mesocrystalline compounds that can be used in LC media according to the present invention.

[0676]

[0677]

[0678]

[0679]

[0680]

[0681]

[0682]

[0683]

[0684]

[0685]

[0686]

[0687]

[0688]

[0689]

[0690]

[0691]

[0692]

[0693]

[0694]

[0695] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, preferably selected from polymerizable compounds of formula RM-1 to RM-182. 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-58, RM-64, RM-74, RM-76, RM-88, RM-91, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-140, RM-142, RM-143, RM-145, RM-146, RM-147, RM-149, RM-156 to RM-163, RM-169, RM-170, and RM-171 to RM-183 are particularly preferred.

[0696] Table F

[0697] Table F shows self-aligning additives for vertical alignment, which, together with polymerizable compounds, can be used in the LC media of the SA-VA and SA-FFS displays according to the present invention:

[0698]

[0699]

[0700]

[0701]

[0702]

[0703]

[0704]

[0705]

[0706]

[0707]

[0708]

[0709]

[0710] In a preferred embodiment, the LC media, SA-VA and SA-FFS displays according to the invention comprise one or more SA additives selected from SA-1 to SA-48, preferably selected from SA-14 to SA-48, and very preferably selected from SA-20 to SA-34 and SA-44, in combination with one or more RMs. Example

[0711] 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.

[0712] In addition, the following abbreviations and symbols were used:

[0713]

[0714] 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).

[0715] 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.

[0716] 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.

[0717] 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.)

[0718] 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.

[0719] 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.

[0720] Displays used to measure capacitive threshold voltages typically consist 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 the liquid crystal molecules.

[0721] A PSVA display or PSVA test chamber used for measuring tilt angles typically consists of two planar parallel glass outer plates spaced approximately 4 µm apart. Unless otherwise specified, each of these outer plates 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.

[0722] Polymerizable compounds are typically 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, 1 kHz) to the display.

[0723] Intensity was measured using a standard instrument (the high end of the Hoenle UV meter with a UV sensor).

[0724] The tilt angle is typically 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.

[0725] 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.

[0726] Example 1

[0727] The absorption wavelength λ of the polymerizable compound Ie of the present invention and the prior art reference polymerizable compound C1 at an extinction coefficient E=0.5 was measured in a DCM solution with a concentration of 3 g / L. The results are shown in Table 1.1.

[0728] Table 1.1 - UV Absorption

[0729]

[0730]

[0731] As can be seen from Table 1, the absorption wavelength of compound Ie in this invention is significantly higher than that of compound C1. Therefore, compound Ie is more suitable for UV photopolymerization at longer wavelengths.

[0732] Nematic LC bulk mixture N1 is prepared as follows

[0733]

[0734] The polymerizable mixture P1 of the present invention is prepared by adding 0.3% of the polymerizable compound Ie to the nematic LC host mixture N1.

[0735] For comparison, the reference polymerizable mixture PC1 was prepared by adding 0.5% of the polymerizable compound C1 to the nematic LC host mixture N1.

[0736] Because compound C1 has a higher molecular weight, the molar amounts of polymerizable compounds in mixtures P1 and PC1 are roughly equivalent.

[0737] An electro-optic VA test chamber with an AF glass substrate containing a polymerizable mixture was exposed to UV light in a two-step process: a first step (UV1) to generate the tilt angle and a second step (UV2) to polymerize any residual monomers not polymerized in the first step. In the UV1 step, a voltage was applied (0.1V step and curing at DC 15V). In the UV2 step, no voltage was applied. A type C fluorescent UV lamp with a 313nm cutoff filter was used as the radiation source. The UV intensity was checked using a UV detector at 313nm. Unless otherwise specified, other conditions were as follows:

[0738] UV1 (Type C lamp): 5mW / cm² for 10 to 300 seconds at room temperature.

[0739] UV2 (Type C lamp): 0.5mW / cm² at RT for 30-60 minutes, or

[0740] UV2 (Type B lamp): 1.8 mW / cm² at RT for 60-120 minutes.

[0741] Tilt angle generation

[0742] The tilt angle produced in the test chamber after changing the irradiation time following the above UV1 step was measured using the OtsukaT_RETS-10 system.

[0743] The time required to achieve an 88° tilt angle is shown in Table 1.2 below.

[0744] Table 1.2 – Inclination Angle

[0745]

[0746] It can be seen that the polymerizable mixture P1 according to the present invention, containing compound Ie, exhibits a significantly faster tilt angle generation than the reference mixture PC1 containing compound C1.

[0747] Residual RM

[0748] The residual content (ppm) of unpolymerized monomers in the mixture was determined after UV photopolymerization. Lower residual monomer content after a given time interval indicates faster polymerization. For this purpose, the polymerizable mixture was filled into a test chamber and tested under RT using a UV photopolymerizer with 0.5 mW / cm². 2 Intensity C-type fluorescent UV lamp or lamp with 1.8mW / cm² 2 Polymerization was performed by varying UV exposure time intervals to a Type B UV lamp of varying intensity. UV intensity was monitored using a UV detector at 313 nm. After a certain time interval of photopolymerization, the test chamber was opened, the mixture was dissolved, rinsed out of the test chamber with methyl ethyl ketone, and analyzed by ultra-high performance liquid chromatography (UPLC).

[0749] The results are shown in Table 1.4.

[0750] Table 1.4 – Residual RM

[0751]

[0752] nd = undetectable

[0753] It can be seen that in the polymerizable mixture P1 of the present invention containing compound Ie, the rate of decrease in the residual monomer content after polymerization is faster than that in the reference polymerizable mixture PC1 containing compound C1.

[0754] Voltage holding ratio (VHR)

[0755] To measure VHR, a polymerizable LC medium was filled into a test chamber, and monomers were polymerized under the same conditions as those described above for generating the tilt angle. VHR was measured before and after exposure to a UV-B or UV-C lamp used in the PSA method described above, with a voltage of 1V / 0.6 Hz applied at 60°C.

[0756] Optical stress typically leads to a decrease in VHR in LC mixtures; therefore, the smaller the absolute decrease in VHR value after stress, the better the display application performance.

[0757] The results are shown in Table 1.5.

[0758] Table 1.5-VHR

[0759]

[0760] As can be seen, for both Type B and Type C lamps, the polymerizable mixture P1 of the present invention containing compound Ie shows an initial VHR value similar to that of the reference mixture PC1 containing compound C1. However, after UV stress, the VHR of mixture P1 of the present invention shows a significantly smaller decrease, while the VHR value of the reference mixture PC1 decreases sharply.

[0761] In summary, the above results confirm that the polymerizable mixtures of the polymerizable compounds containing formula Ie according to the present invention exhibit significant improvements, such as faster tilt angle generation, higher VHR after UV stress, and lower amounts of residual monomer.

[0762] Example 2

[0763] The nematic LC bulk mixture N2 is prepared as follows

[0764]

[0765] The polymerizable mixture P2 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N2.

[0766] Example 3

[0767] The polymerizable mixture P3 was prepared by adding 0.5% of the polymerizable compound If and 100 ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N3.

[0768]

[0769] Example 4

[0770] The nematic LC bulk mixture N3 is prepared as follows:

[0771]

[0772] The polymerizable mixture P4 was prepared by adding 0.5% of compound Ie and 100 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N3.

[0773]

[0774] Example 5

[0775] The polymerizable mixture P5 was prepared by adding 0.5% polymerizable compound Ia and 100 ppm stabilizer ST-3a-1 to the nematic LC host mixture N1.

[0776]

[0777] Example 6

[0778] The polymerizable mixture P6 was prepared by adding 0.5% polymerizable compound Ia and 100 ppm stabilizer ST-3a-1 to the nematic LC host mixture N2.

[0779] Example 7

[0780] The nematic LC bulk mixture N4 is prepared as follows:

[0781]

[0782] The polymerizable mixture P7 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N4.

[0783]

[0784] Example 8

[0785] The polymerizable mixture P8 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N4.

[0786]

[0787] Example 9

[0788] Nematic LC bulk mixture N5 is prepared as follows

[0789]

[0790] The polymerizable mixture P9 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N5.

[0791] Example 10

[0792] Nematic LC bulk mixture N7 is prepared as follows

[0793]

[0794] The polymerizable mixture P10 was prepared by adding 0.5% of compound If and 150 ppm of stabilizer ST-8-1 to the nematic LC host mixture N6.

[0795]

[0796] Example 11

[0797] Nematic LC bulk mixture N8 is prepared as follows

[0798]

[0799]

[0800] The polymerizable mixture P11 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N8.

[0801] Example 12

[0802] Nematic LC bulk mixture N9 is prepared as follows

[0803]

[0804] The polymerizable mixture P12 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture 9.

[0805] Example 13

[0806] Nematic LC bulk mixture N10 is prepared as follows

[0807]

[0808] The polymerizable mixture P13 was prepared by adding 0.5% of compound If and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N9.

[0809] Example 14

[0810] Nematic LC bulk mixture N11 is prepared as follows

[0811]

[0812] The polymerizable mixture P14 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N11.

[0813] Example 15

[0814] Nematic LC bulk mixture N12 is prepared as follows

[0815]

[0816] The polymerizable mixture P15 was prepared by adding 0.4% of compound IA1, 0.3% of compound IB1 and 100 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N11.

[0817] Example 16

[0818] Nematic LC bulk mixture N13 is prepared as follows

[0819]

[0820]

[0821] The polymerizable mixture P16 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-8-1 to the nematic LC host mixture N13.

[0822] Example 17

[0823] Nematic LC bulk mixture N14 is prepared as follows

[0824]

[0825] The polymerizable mixture P17 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-12 to the nematic LC host mixture N14.

[0826]

[0827] Example 18

[0828] Nematic LC bulk mixture N15 is prepared as follows

[0829]

[0830] The polymerizable mixture P18 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N15.

[0831] Example 19

[0832] Nematic LC bulk mixture N16 is prepared as follows

[0833]

[0834]

[0835] The polymerizable mixture P19 was prepared by adding 0.4% of compound Ia and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N16.

[0836] Example 20

[0837] Nematic LC bulk mixture N17 is prepared as follows

[0838]

[0839] The polymerizable mixture P20 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-12 to the nematic LC host mixture N17.

[0840] Example 21

[0841] Nematic LC bulk mixture N18 is prepared as follows

[0842]

[0843]

[0844] The polymerizable mixture P21 was prepared by adding 0.5% of compound IA1, 0.3% of compound IB1 and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N18.

[0845] Example 22

[0846] Nematic LC bulk mixture N19 is prepared as follows

[0847]

[0848] The polymerizable mixture P22 was prepared by adding 0.5% of compound If and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N19.

[0849] Example 23

[0850] The nematic LC bulk mixture N20 is prepared as follows:

[0851]

[0852] The polymerizable mixture P23 was prepared by adding 0.5% of compound Ia and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N20.

[0853] Example 24

[0854] Nematic LC bulk mixture N21 is prepared as follows

[0855]

[0856]

[0857] The polymerizable mixture P24 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-9-1 to the nematic LC host mixture N21.

[0858]

[0859] Example 25

[0860] The nematic LC bulk mixture N22 is prepared as follows

[0861]

[0862]

[0863] The polymerizable mixture P25 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N22.

[0864] Example 26

[0865] Nematic LC bulk mixture N23 is prepared as follows

[0866]

[0867] The polymerizable mixture P26 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N23.

[0868] Example 27

[0869] Nematic LC bulk mixture N24 is prepared as follows

[0870]

[0871]

[0872] The polymerizable mixture P27 was prepared by adding 0.5% of compound Ia and 150 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N24.

[0873] Example 28

[0874] Nematic LC bulk mixture N25 is prepared as follows

[0875]

[0876] The polymerizable mixture P28 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-8-1 to the nematic LC host mixture N25.

[0877] Example 29

[0878] Nematic LC bulk mixture N26 is prepared as follows

[0879]

[0880] The polymerizable mixture P29 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N26.

[0881] Example 30

[0882] Nematic LC bulk mixture N27 is prepared as follows

[0883]

[0884]

[0885] The polymerizable mixture P30 was prepared by adding 0.5% of compound Ia and 100 ppm of stabilizer ST-8-1 to the nematic LC host mixture N27.

[0886] Example 31

[0887] Nematic LC bulk mixture N28 is prepared as follows

[0888]

[0889] The polymerizable mixture P31 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-12 to the nematic LC host mixture N28.

[0890] Example 32

[0891] Nematic LC bulk mixture N29 is prepared as follows

[0892]

[0893] The polymerizable mixture P32 was prepared by adding 0.5% of compound If and 100 ppm of stabilizer ST-9-1 to the nematic LC host mixture N29.

[0894] Example 33

[0895] Nematic LC bulk mixture N30 is prepared as follows

[0896]

[0897] The polymerizable mixture P33 was prepared by adding 0.4% of compound Ia and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N30.

[0898] Example 34

[0899] Nematic LC bulk mixture N31 is prepared as follows

[0900]

[0901] The polymerizable mixture P34 was prepared by adding 0.3% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N31.

[0902] Example 35

[0903] Nematic LC bulk mixture N32 is prepared as follows

[0904]

[0905]

[0906] The polymerizable mixture P35 was prepared by adding 0.3% of compound Ie and 150 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N32.

[0907] Example 36

[0908] Nematic LC bulk mixture N33 is prepared as follows

[0909]

[0910] The polymerizable mixture P36 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-9-1 to the nematic LC host mixture N33.

[0911] Example 37

[0912] Nematic LC bulk mixture N34 is prepared as follows

[0913]

[0914] The polymerizable mixture P37 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N34.

[0915] Example 38

[0916] Nematic LC bulk mixture N35 is prepared as follows

[0917]

[0918]

[0919] The polymerizable mixture P38 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N35.

[0920] Example 39

[0921] Nematic LC bulk mixture N36 is prepared as follows

[0922]

[0923] The polymerizable mixture P39 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-12 to the nematic LC host mixture N36.

[0924] Example 40

[0925] Nematic LC bulk mixture N37 is prepared as follows

[0926]

[0927]

[0928] The polymerizable mixture P40 was prepared by adding 0.5% of compound Ie and 100 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N37.

[0929] Example 41

[0930] Nematic LC bulk mixture N38 is prepared as follows

[0931]

[0932] The polymerizable mixture P41 was prepared by adding 0.4% of compound If and 150 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N38.

[0933] Example 42

[0934] Nematic LC bulk mixture N39 is prepared as follows

[0935]

[0936]

[0937] The polymerizable mixture P42 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-9-1 to the nematic LC host mixture N39.

[0938] Example 43

[0939] Nematic LC bulk mixture N40 is prepared as follows

[0940]

[0941] The polymerizable mixture P43 was prepared by adding 0.4% of compound Ia and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N40.

[0942] Example 44

[0943] Nematic LC bulk mixture N41 is prepared as follows

[0944]

[0945]

[0946] The polymerizable mixture P44 was prepared by adding 0.4% of compound Ie and 100 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N41.

[0947] Example 45

[0948] Nematic LC bulk mixture N42 is prepared as follows

[0949]

[0950] The polymerizable mixture P45 was prepared by adding 0.5% of compound If and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N42.

[0951] Example 46

[0952] Nematic LC bulk mixture N43 is prepared as follows

[0953]

[0954]

[0955] The polymerizable mixture P46 was prepared by adding 0.4% of compound Ie and 100 ppm of stabilizer ST-8-1 to the nematic LC host mixture N43.

[0956] Example 47

[0957] Nematic LC bulk mixture N44 is prepared as follows

[0958]

[0959] The polymerizable mixture P47 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N44.

[0960] Example 48

[0961] Nematic LC bulk mixture N45 is prepared as follows

[0962]

[0963]

[0964] The polymerizable mixture P48 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N45.

[0965] Example 49

[0966] Nematic LC bulk mixture N46 is prepared as follows

[0967]

[0968] The polymerizable mixture P49 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-8-1 to the nematic LC host mixture N46.

[0969] Example 50

[0970] Nematic LC bulk mixture N47 is prepared as follows

[0971]

[0972] The polymerizable mixture P50 was prepared by adding 0.5% of compound Ie and 100 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N47.

[0973] Example 51

[0974] Nematic LC bulk mixture N48 is prepared as follows

[0975]

[0976] The polymerizable mixture P51 was prepared by adding 0.4% of compound Ia and 100 ppm of stabilizer ST-8-1 to the nematic LC host mixture N48.

[0977] Example 52

[0978] Nematic LC bulk mixture N49 is prepared as follows

[0979]

[0980] The polymerizable mixture P52 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N49.

[0981] Example 53

[0982] Nematic LC bulk mixture N50 is prepared as follows

[0983]

[0984]

[0985] The polymerizable mixture P53 was prepared by adding 0.5% of compound If and 100 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N50.

[0986] Example 54

[0987] Nematic LC bulk mixture N51 is prepared as follows

[0988]

[0989] The polymerizable mixture P54 was prepared by adding 0.5% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N51.

[0990] Example 55

[0991] Nematic LC bulk mixture N52 is prepared as follows

[0992]

[0993]

[0994] The polymerizable mixture P55 was prepared by adding 0.4% of compound Ie and 150 ppm of stabilizer ST-3a-1 to the nematic LC host mixture N52.

[0995] Example 56

[0996] Nematic LC bulk mixture N53 is prepared as follows

[0997]

[0998] The polymerizable mixture P56 was prepared by adding 0.5% of compound Ie and 0.6% of SA additive SA-32 to the nematic LC host mixture N53.

[0999]

[1000] Example 57

[1001] Nematic LC bulk mixture N54 is prepared as follows

[1002]

[1003] The polymerizable mixture P57 was prepared by adding 0.5% of compound Ie and 0.6% of SA additive SA-23 to the nematic LC host mixture N54.

[1004]

[1005] Example 58

[1006] Nematic LC bulk mixture N55 is prepared as follows

[1007]

[1008] The polymerizable mixture P58 was prepared by adding 0.5% of compound Ie, 0.6% of SA additive SA-23 and 50 ppm of stabilizer ST-9-1 to the nematic LC host mixture N55.

[1009] Example 59

[1010] Nematic LC bulk mixture N56 is prepared as follows

[1011]

[1012]

[1013] The polymerizable mixture P59 was prepared by adding 0.45% of compound Ie, 0.6% of SA additive SA-32 and 50 ppm of stabilizer ST-8-1 to the nematic LC host mixture N56.

[1014] Example 60

[1015] Nematic LC bulk mixture N57 is prepared as follows

[1016]

[1017] The polymerizable mixture P60 was prepared by adding 0.5% of compound Ie, 0.6% of SA additive SA-32 and 150 ppm of stabilizer ST-8-1 to the nematic LC host mixture N57.

[1018] Example 61

[1019] Nematic LC bulk mixture N58 is prepared as follows

[1020]

[1021] The polymerizable mixture P61 was prepared by adding 0.5% of compound Ie, 0.6% of SA additive SA-32 and 100 ppm of stabilizer ST-3b-1 to the nematic LC host mixture N58.

[1022] Example 62

[1023] Nematic LC bulk mixture N59 is prepared as follows

[1024]

[1025]

[1026] The polymerizable mixture P62 was prepared by adding 0.45% of compound Ie, 0.6% of SA additive SA-32 and 150 ppm of stabilizer ST-9-1 to the nematic LC host mixture N59.

Claims

1. An LC medium comprising one or more polymerizable compounds of formula I. Each group, independently of the others and appearing in the same or different ways, has the following meaning: P is a polymerizable group. Sp can be a spacer group or a single bond. R a For P-Sp- or R b , R b H, a straight-chain, branched, or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2- groups are optionally arranged such that the O and / or S atoms are not directly connected to each other via -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, or CR-. 0 =CR 00 -、-C≡C-、 , , , , or Substitution, and one or more of the H atoms are optionally substituted by F or Cl, L is P-Sp-, F, Cl, -CN or a straight-chain, branched or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2- groups are optionally arranged such that the O and / or S atoms are not directly connected to each other via -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -、-C≡C-、 , , , , or Substitution, and one or more of the 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. r1 can be 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 1 or 2, and most preferably 1. Preferably, the LC medium does not contain any polymerizable compound other than the polymerizable compound of Formula I.

2. The LC medium according to claim 1, characterized in that... In equation I, R a It represents P-Sp-.

3. The LC medium according to claim 1 or 2, characterized in that... The compound of formula I is selected from the following sub-formulas: Wherein P, Sp and L have the meanings given in claim 1 or 2, r1 is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 1 or 2, most preferably 1, and r2 is 0, 1, 2 or 3, very preferably 0 or 1.

4. The LC medium according to one or more of claims 1 to 3, characterized in that... The compound of formula I is selected from the following sub-formulas: Wherein P and L have the meanings given in claim 1, and Sp' has one of the meanings of Sp given in claim 1, which is different from a single bond.

5. The LC medium according to one or more of claims 1 to 4, characterized in that... The compound of formula I is selected from the following sub-formulas:

6. The LC medium according to one or more of claims 1 to 5, characterized in that... It contains one or more compounds of formula II: Each group, independently of the others and appearing in the same or different ways, has the following meaning: R 21 R 22 H, a straight-chain, branched, or cyclic alkyl or alkoxy group having 1 to 20 C atoms, wherein one or more non-adjacent CH2- groups are optionally positioned such that the O- and / or S- atoms are not directly connected to each other via -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, CR 0 =CR 00 -、-C≡C-、 , , , , or Substitution, wherein one or more H atoms are optionally substituted by F, Cl, CN or CF3. R 0 R 00 It is H or an alkyl group having 1 to 12 carbon atoms. A 1 A 2 Groups selected from the following formulas: Z 1 and Z 2 For -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O-, or single bonds. L 1 L 2 L 3 L 4 It can be F, Cl, OCF3, CF3, CH3, CH2F, or CHF2. Y is H, F, Cl, CF3, CHF2, or CH3. L C It is CH3 or OCH3. a1 is 0, 1, or 2. a2 is 0 or 1.

7. The LC medium according to any one of claims 1 to 6, characterized in that... It comprises one or more compounds selected from those of formulas IIA, IIB, IIC, IID, and IIE: Each of these groups, when appearing in turn, has the following meaning, either identically or differently, and independently of each other: R 21 R 22 It is H, an alkyl, alkoxy, or alkenyl group having up to 15 carbon atoms, which is unsubstituted or monosubstituted with F, Cl, CN, or CF3, and furthermore, one or more of these groups can be connected in such a manner that the O- and / or S- atoms are not directly connected to each other via -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC-O, or -O-CO-. , , , , Replacement L 1 To L 4 It can be F, Cl, CF3 or CHF2. Y is H, F, Cl, CF3, CHF2, or CH3. Z 1 Z 2 For single bonds, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O-, p is 0, 1, or 2, and q is 0 or 1.

8. The LC medium according to one or more of claims 1 to 7, characterized in that... It contains one or more compounds of formula III: Each group, independently of the others and appearing in the same or different ways, has the following meaning: R 31 R 32 It is H, an alkyl, alkoxy, or alkenyl group having up to 15 carbon atoms, which is unsubstituted or monosubstituted with F, Cl, CN, or CF3, and furthermore, one or more of these groups can be connected in a manner such that the O- and / or S- atoms are not directly connected to each other via -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC-O-, -O-CO-, Replacement A 3 a) 1,4-cyclohexeneyl or 1,4-cyclohexeneyl, wherein one or both non-adjacent CH2 groups may be substituted with -O- or -S-. b) 1,4-Phenylidene, wherein one or both CH groups may be substituted with N, or c) Select groups from the group consisting of 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. The groups a), b) and c) may be mono- or poly-substituted with halogen atoms. n is 0, 1, or 2. Z 1 For -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 single bonds, L 11 L 12 It can be F, Cl, CF3 or CHF2. W is either O or S. Y 1 Y 2 It can be H, F, Cl, CF3, CHF2, CH3 or OCH3.

9. The LC medium according to one or more of claims 1 to 8, characterized in that... It contains one or more compounds of formula IV: in R 41 This indicates an unsubstituted alkyl group having 1 to 7 carbon atoms, furthermore, one or more of the CH2 groups may be substituted. , or Substitution, or representing an unsubstituted alkenyl group having 2 to 7 carbon atoms, and R 42 It refers to an unsubstituted alkyl group having 1 to 7 carbon atoms or an unsubstituted alkoxy group having 1 to 6 carbon atoms.

10. An LC medium according to one or more of claims 1 to 9, characterized in that... It contains one or more compounds of formula V: in R 51 R 52 Independently representing H, an alkyl, alkoxy, or alkenyl group having up to 15 carbon atoms, which is unsubstituted, monosubstituted with F, Cl, CN, or CF3, or at least monosubstituted with a halogen, and furthermore, one or more of these groups can be represented by CH2 groups such that the O atoms are not directly connected to each other via -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC-O-, -O-CO-, etc. , , , , Replacement Z 51 Z 52 Each can independently represent -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or a single bond, and n is 1 or 2.

11. The LC medium according to one or more of claims 1 to 10, characterized in that... It also includes one or more additives selected from the group consisting of chiral dopants, stabilizers, polymerization initiators and self-aligning additives.

12. A method for preparing an LC medium according to one or more of claims 1 to 11, comprising the following steps: Mix one or more polymerizable compounds of formula I as defined in one or more of claims 1 to 5 with one or more compounds of formula II as defined in claim 6 and optionally one or more compounds of formulas IIA-IIE, III, IV and / or V as defined in one or more of claims 7 to 10, and optionally with additional liquid crystal compounds and / or additives, and optionally polymerize the polymerizable compounds.

13. An LC display comprising an LC medium as defined in one or more of claims 1 to 11.

14. The LC display according to claim 13, wherein it is a PS-VA, PS-IPS, PS-FFS or SA-VA display.

15. The LC display according to claim 13 or 14, characterized in that... It comprises two substrates, at least one of which is transparent to light; electrodes disposed on each substrate or two electrodes disposed on only one of the substrates; and an LC dielectric layer positioned between the substrates according to one or more of claims 1 to 11, wherein the polymerizable compound is polymerized between the substrates of the display by UV photopolymerization.

16. A method of manufacturing an LC display according to claim 15, comprising the following steps: An LC medium according to one or more of claims 1 to 11 is provided between the substrates of the display, and the polymerizable compound is polymerized by irradiation with UV light, wherein optionally a voltage is applied to the electrodes of the display during the polymerization of the polymerizable compound.

17. Use of an LC medium according to one or more of claims 1 to 11, or an LC display according to one or more of claims 13 to 15, or the method according to claim 16 for an energy-saving LC display or a method for manufacturing an energy-saving LC display.

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