Liquid-crystal display

Abstract

The present invention relates to an LC display of an improved PSA (polymer sustained alignment) mode comprising an LC medium comprising one or more polymerizable compounds, to an LC medium as used in the said LC display, and to a process of producing the said LC display using the said LC medium, especially an energy-saving LC display and energy-saving LC display production process.

Description

[0001] P23167 De - 1 - Liquid-Crystal Display Field of the Invention 5 The present invention relates to an LC display of an improved PSA (polymer sustained alignment) mode comprising an LC medium comprising one or more polymerizable compounds, to an LC medium as used in the said LC display, and to a process of producing the said LC display using the said LC medium, especially an energy-saving LC display and energy-saving LC 10 display production process. Background and Prior Art The popularity of 8K television and gaming monitors leads to an increased 15 need for LC display (LCD) panels having higher refresh rates and thus for LC media having faster response times. Many of these LCD panels are using polymer stabilized (PS) or polymer sustained alignment (PSA) modes, like the PS-VA (vertically aligned), PS-IPS (in-plane switching) or PS-FFS (fringe-field switching) mode or modes derived therefrom, or self-aligned (SA) modes like 20 the SA-VA mode which are polymer stabilized. In the PS or PSA mode a small amount, typically from 0.1 to 1% of one or more polymerizable mesogenic compounds, also known as RMs (reactive mesogens), is added to the LC medium. After filling the LC medium into the 25 display the RMs are then polymerized in situ by UV photopolymerization, while a voltage is applied to the electrodes of the display. Thereby a small tilt angle is generated in the LC molecules of the LC medium, which is stabilized by the polymerized RMs. The UV polymerization process, also referred to as “PSA process”, is usually carried out in two steps, a first UV exposure step ("UV1 30 step"), with application of a voltage, to generate the tilt angle, and a second UV exposure step ("UV2 step"), without application of a voltage, to complete polymerization of the RMs. In the SA-VA mode the alignment layers are omitted in the display. Instead, a 35 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, for example P23167 De - 2 - homeotropic or planar alignment, in situ by a self assembling mechanism. The SA additive usually contains an organic, mesogenic core group and attached thereto one or more polar anchor groups, for example hydroxy, carboxy, amino or thiol groups, which are capable of interacting with the 5 substrate surface, causing the additives on the substrate surface to align and induce the desired alignment also in the LC molecules. The SA additive may also contain one or more polymerizable groups that can be polymerized under similar conditions as the RMs used in the PSA process. The LC medium may in addition to the SA additive also contain one or more RMs. 10 However, there is still a need for further reducing the response times, especially for use in gaming monitors, and the development of new RMs and LC media enabling faster response times, while maintaining other desirable properties like a high reliability, becomes more and more challenging. 15 In the display manufacturing process of PSA mode displays, as radiation source for the UV1 step and / or UV2 step typically a UV C-type and / or a UV B-type lamp is used. A UV C-type lamp typically has an emission spectrum wherein the shortest UV wavelength is ~300nm, while a A UV B-type lamp 20 typically has an emission spectrum wherein the shortest UV wavelength is ~320nm. On the other hand, in order to achieve a low viscosity and fast response times, the LC host mixtures of polymerizable LC media used in PSA mode 25 displays often contain one or more compounds with an alkenyl group. However, this may lead to a decrease of the reliability of the mixture, and to a large drop of its voltage holding ratio (VHR), when being exposed to the UV light needed to polymerize the RMs. Thus is especially problematic when using shorter UV wavelengths of less than 320nm. Therefore there is a 30 desire to use longer UV wavelengths for the PSA process. However, the change of the radiation source to enable longer UV wavelengths in a running display mass production process is costly and time consuming. Also, this would then pose the problem to find RMs which have 35 an absorption at longer wavelengths that is high enough to enable quick and complete photopolymerization. P23167 De - 3 - UV-LED lamps have also been proposed for use in the PSA process, as they show less energy consumption, longer lifetime and more effective optical energy transfer to the LC medium due to the narrower emission peak, which 5 allows to reduce the UV intensity and / or UV irradiation time. This enables a reduced tact time and savings in energy and production costs. Therefore, there is a need for polymerizable LC media and LC displays which have the known advantages of PSA displays and in addition show faster 10 response times, and at the same time enable carrying out the PSA process at longer UV wavelengths, especially in the range from 320 to 400 nm. In addition, there is a great demand for improved PSA or SA displays, and LC media and polymerizable compounds for use therein displays, which 15 show very fast response times even at low temperatures, a high reliability and high VHR values after UV exposure, a high specific resistance, a large working-temperature range, a low threshold voltage, a strong tilt angle, a high tilt stability, a multiplicity of grey shades, a high contrast and a broad viewing angle, and, in case of the polymerizable compounds, have low melting points 20 and a high solubility in the LC host mixtures. In displays for mobile applications, it is especially desired to have available LC media that show low threshold voltage and high birefringence. Moreover, there is a great demand for improved PSA or SA displays, and LC 25 media and polymerizable compounds for use therein displays, which enable fast response times, show good UV absorption especially at UV wavelengths in the range from 320 to 400 nm, especially 320 to 380 nm, enable quick and complete polymerization of the RMs, allow the generation of a low tilt angle, preferably as quickly as possible, enable a high stability of the tilt angle even 30 after longer time and / or after UV exposure, reduce or prevent the occurrence of "image sticking" and "ODF mura" in the display, and in case of the RMs polymerize as rapidly and completely as possible and show a high solubility in the LC media which are typically used as host mixtures in PSA or SA displays. 35 The present invention is based on the object of providing improved PSA and SA displays, and improved materials, in particular RMs and LC media P23167 De - 4 - comprising the same for use in these displays, which fulfil one or more of the above-mentioned demands. A further object aim of the invention is to provide LC media for use in 5 improved PSA displays wherein the RMs exhibit both fast polymerization speed and good reliability parameters, like high VHR or good tilt stability. A further object of the invention is to provide improved LC media containing RMs, in particular for optical, electro-optical and electronic applications, and 10 of suitable processes and intermediates for the preparation thereof. A further object of the invention is to provide improved LC media containing RMs which show one or more of the following advantageous effects: - they enable very fast response times, 15 - they generate a tilt angle to a desired degree after exposure to UV-light, - they enable good control of the tilt angle generation, - they lead to high and stable VHR and only small decrease of the VHR after UV stress, especially in case of LC media based on LC host mixtures which contain alkenyl compounds, 20 - they show good UV absorption especially at UV wavelengths in the range from 320 to 400 nm, especially 320 to 380 nm, - they are suitable for use in PSA displays prepared by a polymerization process using a UV C-type lamp and / or a UV B-type lamp, - they are suitable for use in PSA displays prepared by a polymerization 25 process using a UV-LED lamp, - they enable good control of the the time range of the first UV-step in which the tilt angle is generated during UV-processing, - they lead to good tilt stability, - they enable to keep the time range of the second UV-step, in which any 30 residual RM is polymerized and the tilt angle is stabilized, as short as possible to minimize energy consumption and production cost, - after the first and second UV-exposure step, the residual RMs have less or no negative effects on the LC-mixture performance parameters, such as VHR, tilt stability, etc. P23167 De - 5 - Further objects of the present invention are immediately evident to the person skilled in the art from the following detailed description. It was found that one or more of these objects could be achieved by 5 providing improved PSA and SA displays, and improved RMs and LC media comprising such RMs for use in these displays, as disclosed and claimed hereinafter. Thus, it was surprisingly found that one or more of the above objects could 10 be achieved by providing a PSA display which contains an LC medium that comprises one or more RMs in a significantly higher amount than used in conventional PSA displays, and comprises at least one RM which shows an absorption edge at longer UV wavelengths. 15 Summary of the Invention The present invention thus relates to a liquid crystal display (LCD) of the polymer-stabilized alignment (PSA) mode, preferably of the polymer stabilized vertical aligned (PSVA) mode, which comprises an LC medium 20 comprising from 2.5 to 7%, preferably from 3 to 6%, very preferably from 3.5 to 5.5%, of one or more, preferably two or more, polymerizable mesogenic compounds (hereinafter also referred to as “reactive mesogens” or “RMs”), wherein preferably at least one of these polymerizable mesogenic compounds or RMs has an absorption edge in the wavelength range from 25 300 to 340 nm, preferably from 320 to 340 nm. In a preferred embodiment the LC medium contains only one RM, which is present in a concentration from 2.5 to 7%, preferably from 3 to 6%, very preferably from 3.5 to 5.5% in the LC medium and has an absorption edge in 30 the wavelength range from 300 to 340 nm, preferably from 320 to 340 nm. In another preferred embodiment the LC medium contains a first RM and a second RM, wherein the first RM has an absorption edge in the wavelength range from 300 to 340 nm, preferably from 320 to 340 nm, and wherein the 35 second RM has an absorption edge at a longer wavelength than the first RM, P23167 De - 6 - and preferably the concentration of the second RM is lower than the concentration of the first RM. Preferably, the first RM has an absorption edge in the wavelength range from 5 300 to 340 nm, preferably from 320 to 340 nm, and the second RM has an absorption edge in the wavelength range from 330 to 400 nm, very preferably from 330 to 380 nm, most preferably from 340 to 370 nm. Preferably, the concentration of the first RM in the LC medium is from 2.4 to 10 6.5%, very preferably from 3.5 to 5.5% by weight, and the concentration of the second RM in the LC medium is from 0.01 to 0.5%, very preferably from 0.02 to 0.1% by weight. Preferably, the proportion of the first RM is 90% or more, very preferably 95% 15 or more, most preferably 99% or more, of the total amount of all RMs in the LC medium, and the proportion of the second RM is 10% or less, very preferably 5% or less, most preferably 0.5% or less, of the total amount of all RMs in the LC medium. 20 Preferably, the LC medium contains only polymerizable mesogenic compounds selected from the first RM and the second RM as defined above and below. Very preferably the LC medium contains only (or exactly) two polymerizable mesogenic compounds, one of which is the first RM and the other is the second RM as defined above and below. 25 The polymerizable mesogenic compounds or RMs, including the first and second RM, are preferably selected from the group consisting of the following formulae: P23167 De - 7 - 10 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings Aa, Abphenylene-1,4,-diyl or naphthalene,2-6-diyl which is optionally 15 substituted by one or more groups L, Za, Zb-CH=CH-, -CF=CF-, -C ^C- or a single bond, preferably a single bond, 20 P a polymerizable group, Sp a spacer group that is optionally substituted by one or more groups P, or a single bond, 25 L F, Cl, -CN or straight chain, branched or cyclic alkyl having 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- , in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H atoms 35 are each optionally replaced by P, F or Cl, P23167 De - 8 - R0, R00H or alkyl having 1 to 12 C atoms, a, b 0, 1 or 2, preferably 0 or 1, 5 k 0 or 1, r1, r2 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 0 or 1, r3 0, 1, 2 or 3, preferably 0 or 1. 10 The LC medium according to the present invention preferably comprises a liquid crystal component A (hereinafter also referred to as "LC host mixture") having negative dielectric anisotropy comprising, preferably consisting of, mesogenic or liquid-crystalline molecules, and a polymerizable component B 15 comprising, preferably consisting of, one or more polymerizable mesogenic compounds or RMs as described above and below. The LC medium or LC host mixture preferably comprises one or more compounds of formula II: 20 II 25 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings 30 R21, R22H, straight chain, 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-, 35 , P23167 De - 9 - , in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H atoms are 5 each optionally replaced by F, Cl, CN or CF3, preferably alkyl or alkoxy having 1 to 6 C atoms, R0, R00H or alkyl having 1 to 12 C atoms, 10 A1, A2a group selected from the following formulae: 15 20 25 preferably from formulae A1, A2, A3, A4, A5, A6, A9 and A10, very preferably from formulae A1, A2, A3, A4, A5, A9 and A10, 35 P23167 De - 10 - Z1, Z2-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, 5 L1, L2, L3, L4F, Cl, OCF3, CF3, CH3, CH2F or CHF2, preferably F or Cl, very preferably F, Y H, F, Cl, CF3, CHF2or CH3, preferably H or CH3, very preferably H, 10 LCCH3or OCH3, preferably CH3, a1 0, 1 or 2, 15 a2 0 or 1. The invention further relates to an LC medium as described above and below. 20 The invention furthermore relates to a process for preparing an LC medium as described above and below, comprising the steps of mixing one or more polymerizable compounds selected from formulae IA, IB and IC with one or more compounds of formula II and optionally with further LC compounds and / or additives. 25 The invention further relates to a method of manufacturing an LC display according to the present invention as described above and below. The invention further relates to the use of an LC display according to the 30 present invention as described above and below as energy-saving display. The invention furthermore 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. 35 P23167 De - 11 - The invention furthermore relates to an LC display comprising an LC medium as described above and below wherein the polymerizable compounds are present in polymerized form, which is preferably a PS-VA, PS-IPS, PS-FFS or SA-VA display. 5 The invention furthermore relates to an LC display of the PSA mode as described above and below which comprises two substrates, at least one which is transparent to light, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and located between the 10 substrates a layer of an LC medium as described above and below, wherein the polymerizable compounds are polymerized between the substrates of the display by UV photopolymerization. The invention furthermore relates to a process for manufacturing an LC 15 display of the PSA mode as described above and below, comprising the steps of filling or otherwise providing an 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 >320 nm, more preferably in the range from 320 to 400 20 nm, very preferably in the range from 320 to 380 nm, and preferably while a voltage is applied to the electrodes of the display. The invention furthermore relates to a process for manufacturing an LC display of the PSA mode as described above and below, wherein irradiation 25 of the polymerizable compounds is carried out using a UV C-type and / or a UV B-type lamp. Brief Description of the Drawings 30 Fig.1 shows the VT (voltage vs. transmittance) curve for PSA displays according to Example 1 and Comparison Example 1. Fig.2 shows the VT curve for PSA displays according to Example 2 and Comparison Example 2. 35 P23167 De - 12 - Terms and Definitions An alkenyl group in the compounds of formula II or other components of the LC medium as disclosed below is not considered to be within the meaning of 5 the term “polymerizable group” as used herein. The conditions for the polymerization of the polymerizable compounds of the LC medium are preferably selected such that alkenyl substituents do not participate in the polymerization reaction. Preferably the LC media disclosed and claimed in the present application do not contain an additive that initiates or enhances 10 the participation of the alkenyl group in a polymerization reaction. Unless stated otherwise, the polymerizable compounds and the compounds of formula II are preferably selected from achiral compounds. 15 The expression “absorption edge (at a certain wavelength or in a certain range)” means that the absorption spectrum of the respective compound has a discontinuity, e.g. an absorption peak, at the said certain wavelength or in the said certain wavelength range. Preferably the absorption edge of the respective compound is a wavelength at which the extinction coefficient E is 20 0.5, unless stated otherwise measured in dichloromethane (DCM) at a concentration of 0.3 g / L. 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 25 wavelength limit (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, in the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit and / or that the UV absorption spectrum of the respective chemical 30 compound has a long or short wavelength tail that extends into the given wavelength range or above the given lower wavelength limit or below the given upper wavelength limit. As used herein, the term “full width half maximum” or “FWHM” means the 35 width of a spectrum curve measured between those points on the y-axis which are half the maximum amplitude. P23167 De - 13 - As used herein, the term "substantially transmissive" means that the filter transmits a substantial part, preferably at least 50% of the intensity, of incident light of the desired wavelength(s). As used herein, the term 5 "substantially blocking" means that the filter does not transmit a substantial part, preferably at least 50% of the intensity, of incident light of the undesired wavelengths. As used herein, the term "desired (undesired) wavelength" e.g. in case of a band pass filter means the wavelengths inside (outside) the given range of ^, and in case of a cut-off filter means the wavelengths above 10 (below) the given value of ^. As used herein, the terms "active layer" and "switchable layer" mean a layer in an electrooptical display, for example an LC display, that comprises one or more molecules having structural and optical anisotropy, like for example LC 15 molecules, which change their orientation upon an external stimulus like an electric or magnetic field, resulting in a change of the transmission of the layer for polarized or unpolarized light. As used herein, the terms "tilt" and "tilt angle" will be understood to mean a 20 tilted alignment of the LC molecules of an LC medium relative to the surfaces of the cell in an LC display (here preferably a PSA display), and will be understood to be inclusive of "pretilt" and "pretilt angle". The tilt angle here denotes the average angle (< 90°) between the longitudinal molecular axes of the LC molecules (LC director) and the surface of the plane-parallel outer 25 plates which form the LC cell. A low absolute value for the tilt angle (i.e. a large deviation from the 90° angle) corresponds to a large tilt here. A suitable method for measurement of the tilt angle is given in the examples. Unless indicated otherwise, tilt angle values disclosed above and below relate to this measurement method. 30 As used herein, the terms “polymerizable mesogenic compound”, "reactive mesogen" and "RM" will be understood to mean a compound containing a mesogenic or liquid crystalline skeleton, and one or more functional groups attached thereto which are suitable for polymerization and are also referred 35 to as "polymerizable group" or "P". P23167 De - 14 - Unless stated otherwise, the term "polymerizable compound" as used herein will be understood to mean a polymerizable monomeric compound. As used herein, the concentration of an RM (or polymerizable mesogenic 5 compound) in an LC medium or in a display according to the present invention is given in % by weight of the LC medium and means the initial concentration of the said RM, i.e., before it is being polymerized in accordance with the PSA process. 10 An SA-VA display according to the present invention will be of the polymer stabilised mode as it contains, or is manufactured by use of, an LC medium containing RMs as described above and below. Consequently as used herein, the term "SA-VA display" when referring to a display according to the present invention will be understood to refer to a polymer stabilised SA-VA 15 display even if not explicitly mentioned. As used herein, the term "low-molecular-weight compound" will be understood to mean to a compound that is monomeric and / or is not prepared by a polymerization reaction, as opposed to a "polymeric compound" or a 20 "polymer". As used herein, the term "unpolymerizable compound" will be understood to mean a compound that does not contain a functional group that is suitable for polymerization under the conditions usually applied for the polymerization of 25 the RMs. The term "mesogenic group" as used herein is known to the person skilled in the art and described in the literature, and means a group which, due to the anisotropy of its attracting and repelling interactions, essentially contributes 30 to causing a liquid-crystal (LC) phase in low-molecular-weight or polymeric substances. Compounds containing mesogenic groups (mesogenic com- pounds) do not necessarily have to have an LC phase themselves. It is also possible for mesogenic compounds to exhibit LC phase behaviour only after mixing with other compounds and / or after polymerization. Typical mesogenic 35 groups are, for example, rigid rod- or disc-shaped units. An overview of the terms and definitions used in connection with mesogenic or LC compounds is P23167 De - 15 - given in Pure Appl. Chem.2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem.2004, 116, 6340-6368. The term "spacer group", hereinafter also referred to as "Sp", as used herein 5 is known to the person skilled in the art and is described in the literature, see, for example, Pure Appl. Chem.2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem.2004, 116, 6340-6368. As used herein, the terms "spacer group" or "spacer" mean a flexible group, for example an alkylene group, which connects the mesogenic group and the polymerizable group(s) 10 in a polymerizable mesogenic compound. Above and below, denotes a trans-1,4-cyclohexylene ring, O 15 and denotes a 1,4-phenylene ring. In a group the single bond shown between the two ring atoms can be attached to any free position of the benzene ring. 20 If in the formulae shown above and below a terminal group like R1A, 2A, R1, R2, R11,12,13, R31, 32, R41,42, R51,52, R61,62, R71,72, R81,82,83, RQ, R0, R, RM, RS, RS1,S2,S3,S4or L denotes an alkyl radical and / or an alkoxy radical, this may be straight-chain or branched. It is preferably straight-chain, has 2, 3, 4, 5, 6 or 25 7 C atoms and accordingly preferably denotes ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or heptyloxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy. 30 If one of the aforementioned terminal groups denotes an alkyl radical wherein one or more CH2 groups are replaced by S, this may be straight-chain or branched. It is preferably straight-chain, has 1, 2, 3, 4, 5, 6 or 7 C atoms and accordingly preferably denotes thiomethyl, thioethyl, thiopropyl, thiobutyl, 35 thiopentyl, thiohexyl or thioheptyl. P23167 De - 16 - Oxaalkyl preferably denotes straight-chain 2-oxapropyl (= methoxymethyl), 2- (= 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-oxa- 5 decyl. If one of the aforementioned terminal groups denotes an alkoxy or oxaalkyl group it may also contain one or more additional oxygen atoms, provided that oxygen atoms are not linked directly to one another. 10 If one of the aforementioned terminal groups denotes an alkyl radical in which one CH2group has been replaced by -CH=CH-, this may be straight- chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Accordingly, it denotes, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- 15 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. If one of the aforementioned terminal groups denotes an alkyl or alkenyl 20 radical which is at least monosubstituted by halogen, this radical is preferably straight-chain, and halogen is preferably F or Cl. In the case of polysubstitution, halogen is preferably F. The resultant radicals also include perfluorinated radicals. In the case of monosubstitution, the fluorine or chlorine substituent may be in any desired position, but is preferably in the 25 ^-position. In another preferred embodiment, one or more of the aforementioned terminal groups, like R1A, 2A, R1, R2, R11,12,13, R31, 32, R41,42, R51,52, R61,62, R71,72, R81,82,83, RQ, R0, R, RM, RS, RS1,S2,S3,S4or L are selected from the group 30 consisting of P23167 De - 17 - -S1-F, -O-S1-F, -O-S1-O-S2, wherein S1is C1-12-alkylene or C2-12-alkenylene and S2is H, C1-12-alkyl or C2-12-alkenyl, and very preferably are selected from the of 15 If in the formulae shown above and below a group R1-13, R51, R52, RQ, R, R2A, R2B, RIIIA, R1N, R2N, RB1, RB2, RCR1, RCR2, R or L denotes an alkyl radical in which one CH2 group has been replaced by -CH=CH-, this may be straight- chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Accordingly, it denotes, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- 20 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. If in the formulae shown above and below a group R1-13, R51, R52, RQ, R, R2A, 25 R2B, RIIIA, R1N, R2N, RB1, RB2, RCR1, RCR2, R or L denotes an alkyl or alkenyl radical which is at least monosubstituted by halogen, this radical is preferably straight-chain, and halogen is preferably F or Cl. In the case of polysubstitution, halogen is preferably F. The resultant radicals also include perfluorinated radicals. In the case of monosubstitution, the fluorine or 30 chlorine substituent may be in any desired position, but is preferably in the ^-position. Halogen is preferably F or Cl, very preferably F. 35 The group -CR0=CR00- is preferably -CH=CH-. P23167 De - 18 - -CO-, -C(=O)- and -C(O)- denote a carbonyl group, i.e. . Preferred substituents L, are, for example, F, Cl, Br, I, -CN, -NO2, -NCO, - 5 NCS, -OCN, -SCN, -C(=O)N(Rx)2, -C(=O)Y1, -C(=O)Rx, -N(Rx)2, straight- chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy each having 1 to 25 C atoms, in which one or more H atoms may optionally be replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, straight-chain or branched alkenyl 10 having 2 to 12 C atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15, C atoms, wherein Rxdenotes H, F, Cl, CN, or straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH2-groups are 15 optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-, and 20 Y1denotes halogen. 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, - 25 CH=CH-CH=CH2or -C(CH3)=CH2. 30 in which L has one of the meanings indicated above. The polymerizable group P is a group which is suitable for a polymerization reaction, such as, for example, free-radical or ionic chain polymerization, polyaddition or polycondensation, or for a polymer-analogous reaction, for 35 example addition or condensation onto a main polymer chain. Particular preference is given to groups for chain polymerization, in particular those P23167 De - 19 - containing a C=C double bond or -C ^C- triple bond, and groups which are suitable for polymerization with ring opening, such as, for example, oxetane or epoxide groups. 5 Preferred P are selected from the of which W1denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH3, W2and W3each, independently of one another, 20 denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W4, W5and W6each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W7and W8each, 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 25 radicals L as defined above which are other than P-Sp-, k1, k2and k3each, independently of one another, denote 0 or 1, k3preferably denotes 1, and k4denotes an integer from 1 to 10. P are selected from the of P23167 De - 20 - , (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, , (CH2=CH-CH2)2N-CO-, CH2=CW1-CO-NH-, k1-Phe-(O)k2-, CH2=CH-(CO)k1-Phe-(O)k2-, Phe-CH=CH- and which W1denotes H, F, Cl, CN, CF3, phenyl or alkyl having 1 to 5 5 C atoms, in particular H, F, Cl or CH3, W2and W3each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W4, W5and W6each, independently of one another, denote Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W7and W8each, independently of one another, denote H, Cl or alkyl having 1 to 5 C atoms, 10 Phe denotes 1,4-phenylene, k1, k2and k3each, independently of one another, denote 0 or 1, k3preferably denotes 1, and k4denotes an integer from 1 to 10. Very particularly preferred groups P are selected from the group consisting of 20 Further preferred polymerizable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, most preferably from acrylate and methacrylate. Very preferably all polymerizable groups in the polymerizable compounds as 25 used in the present invention have the same meaning. If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X", so that the respective radical P-Sp- conforms to the formula P-Sp"-X"-, wherein 30 Sp" denotes linear or branched alkylene having 1 to 20, preferably 1 to 12, C atoms, which is optionally mono- or polysubstituted by F, Cl, Br, I or CN and in which, in addition, one or more non-adjacent CH2 groups may each be replaced, independently of one another, by -O-, -S-, -NH- 35 , -N(R0)-, -Si(R0R00)-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S- , -N(R00)-CO-O-, -O-CO-N(R0)-, -N(R0)-CO-N(R00)-, -CH=CH- or -C ^C- P23167 De - 21 - in such a way that O and / or S atoms are not linked directly to one another, X" denotes -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R0)-, -N(R0)- 5 CO-, -N(R0)-CO-N(R00)-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, - OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, - N=CH-, -N=N-, -CH=CR0-, -CY2=CY3-, -C ^C-, -CH=CH-CO-O-, -O-CO- CH=CH- or a single bond, 10 R0and R00each, independently of one another, denote H or alkyl having 1 to 20 C atoms, and Y2and Y3each, independently of one another, denote H, F, Cl or CN. 15 X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR0-, -NR0- CO-, -NR0-CO-NR00- or a single bond. 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-, - 20 CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR0R00-O)p1-, in which p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R0and R00have the meanings indicated above. Particularly preferred groups Sp and -Sp"-X"- are -(CH2)p1-, -(CH2)p1-O-, - 25 (CH2)p1-O-CO-, -(CH2)p1-CO-O-, -(CH2)p1-O-CO-O-, in which p1 has one of the meanings indicated above. Particularly preferred groups Sp" are, in each case straight-chain, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, 30 decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methylimino- ethylene, 1-methylalkylene, ethenylene, propenylene and butenylene. In a preferred embodiment of the invention the compounds of formula IA 35 and / or IB and their subformulae contain a spacer group Sp that is substituted P23167 De - 22 - by one or more polymerizable groups P, so that the group Sp-P corresponds to Sp(P)s, with s being ≥2 (branched polymerizable groups). Preferred compounds of formula IA and IB according to this preferred 5 embodiment are those wherein s is 2, i.e. compounds which contain a group Sp(P)2. Very preferred compounds of formula IA and IB according to this preferred embodiment contain a group selected from the following formulae: -X-alkyl-CHPP S1 10 -X-alkyl-CH((CH2)aaP)((CH2)bbP) S2 -X-N((CH2)aaP)((CH2)bbP) S3 15 -X-alkyl-CHP-CH2-CH2P S4 -X-alkyl-C(CH2P)(CH2P)-CaaH2aa+1S5 -X-alkyl-CHP-CH2P S6 20 -X-alkyl-CPP-CaaH2aa+1S7 -X-alkyl-CHPCHP-CaaH2aa+1S8 25 in which P is as defined in formula I, alkyl denotes a single bond or straight-chain or branched alkylene having 1 to 12 C atoms which is unsubstituted or mono- or polysubstituted by F, Cl or CN and in which one or more non-adjacent CH2groups 30 may each, independently of one another, be replaced by -C(R0)=C(R0)-, -C ^C-, -N(R0)-, -O-, -S-, -CO-, -CO-O-, -O-CO- , -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another, where R0has the meaning indicated above, 35 aa and bb each, independently of one another, denote 0, 1, 2, 3, 4, 5 or 6, P23167 De - 23 - X has one of the meanings indicated for X", and is preferably O, CO, SO2, O-CO-, CO-O or a single bond. Preferred spacer groups Sp(P)2are selected from formulae S1, S2 and S3. 5 Very peferred spacer groups Sp(P)2are selected from the following subformulae: -CHPP S1a 10 -O-CHPP S1b -CH2-CHPP S1c 15 -OCH2-CHPP S1d -CH(CH2-P)(CH2-P) S2a -OCH(CH2-P)(CH2-P) S2b 20 -CH2-CH(CH2-P)(CH2-P) S2c -OCH2-CH(CH2-P)(CH2-P) S2d 25 -CO-NH((CH2)2P)((CH2)2P) S3a P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide, very preferably from acrylate and methacrylate, most preferably from 30 methacrylate. Further preferably all polymerizable groups P that are present in the same compound have the same meaning, and very preferably denote acrylate or methacrylate, most preferably methacrylate. 35 P23167 De - 24 - Sp preferably denotes a single bond or -(CH2)p1-, -(CH2)p2-CH=CH-(CH2)p3-, - O-(CH2)p1-, -O-CO-(CH2)p1, or -CO-O-(CH2)p1, wherein p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently of each other 0, 1, 2 or 3 and, if Sp is -O-(CH2)p1-, -O-CO-(CH2)p1or -CO-O-(CH2)p1the O-atom or CO- 5 group, respectively, is linked to the benzene ring. Detailed Description of the Invention It was surprisingly found that the improved PSA displays according to the 10 present invention enable to achieve significant advantages like faster response time, improved reliability, high VHR after UV stress, quick and complete polymerization with a very low amount of residual, unreacted RMs, and high tilt stability. 15 The PSA displays and LC media according to the present invention are characterized in that they contain 2.5 to 7%, preferably from 3 to 6%, very preferably from 3.5 to 5.5% by weight of one or more RMs, before the PSA process of polymerizing the RMs is carried out. This is significantly higher than the initial RM content of 0.1 to 1% of RMs as typically used in 20 conventional PSA displays. When polymerizing the RMs in a PSA display according to the present invention in accordance with the PSA process, the RMs due to their higher concentration will form a polymer network that penetrates through the whole 25 display cell. In contrast thereto, in conventional PSA displays the polymerized RMs are usually confined to the surfaces of the cell substrates where they form an, often discontinuous, layer. The polymer network formed by the polymerized RMs in a PSA display 30 according to the present invention can more efficiently enhance the elastic constants of the LC medium, which enables faster response times compared to the conventional PSA mode. The improved PSA displays according to the present invention are therefore 35 different from the conventional PSA displays known from prior art. A PS(V)A P23167 De - 25 - display according to the present invention is hereinafter also called “Boost PS(V)A mode display”. Moreover, the LC media as used in the PSA displays according to the 5 present invention are characterized in that they contain one or more RMs which show an absorption edge at longer UV wavelengths, preferably in the range from 320 to 400 nm, more preferably in the range from 330 to 380 nm. Thereby it is possible to use long UV wavelength radiation sources or even UV LED lamps in the PSA process, which enables an improved reliability of 10 the LC medium, higher VHR values after UV stress and a higher tilt stability. On the other hand, due to the polymer network formed by the higher RM concentration in the LC host mixture a higher driving voltage is required compared to the conventional PSA mode displays. It is therefore of particular 15 relevance to have available LC media which enable high reliability and less image sticking. Also, the PSA displays show a flatter, i.e., less steep, VT (voltage- transmission) curve than conventional PSA displays, which allows a better 20 control of the grey shades and contrast. Moreover, the LC media according to the present invention show the following advantageous properties when used in Boost PSA displays: - very fast response times, 25 - good control of the tilt angle generation, - a suitable tilt generation which is inside a certain process window, - fast polymerization leading to minimal residues of RM after the UV-process, - a high voltage-holding-ratio after the UV-process, - good tilt stability, 30 - good VHR, - sufficient stability against heat, - sufficient solubility in organic solvents typically used in display manufacture. In addition the LC media according to the present invention show one or 35 more of the following advantageous properties: - they generate a tilt angle to a desired degree after exposure to UV-light, P23167 De - 26 - - they provide a high tilt stability, - they show good UV absorption especially at longer UV wavelengths from 320 to 400 nm, preferably in the range from 330 to 380 nm, and enable quick and complete polymerization of the RMs at these wavelengths, 5 - they are suitable for use in PSA displays prepared by a polymerization process using a UV C-type or UV B-type lamp, - they enable to control the time range of the first UV-step in which the tilt angle is generated during UV-processing, - they keep the time range of the second UV-step as short as possible to 10 minimize production cost, - after the first and second UV-exposure step, they reduce or avoid any negative effects of the residual RM on the LC mixture performance parameters, such as VHR, tilt stability, etc. 15 In a preferred embodiment the LC medium comprises at least one first RM and at least one second RM. The concentration of the first RM, hereinafter also referred to as “main RM”, in the LC medium is preferably higher than the concentration of the second RM, hereinafter also referred to as “doping RM”, in the LC medium. 20 Further preferably the second or doping RM has a longer wavelength absorption edge than the first or main RM. Preferably the first RM has an absorption edge in the wavelength range from 25 300 to 340 nm, preferably from 320 to 340 nm, and the second RM has an absorption edge in the wavelength range from 330 to 400 nm, very preferably from 330 to 380 nm, most preferably from 340 to 370 nm. Without wishing to be bound to a specific theory, the inventors of the present 30 invention believe that during the tilt generation process, the doping RM will mainly absorb the UV radiation energy, and will both react itself and also trigger a part of the main RM into reaction, and thereby the tilt angle of the LC molecules can be well controlled. Therefore, only a small proportion of the doping RM is required, while the main RM makes up the major proportion of 35 the polymerizable component. Since suitable RMs with a longer absorption wavelength >330 nm are often difficult to find and more costly, this enables P23167 De - 27 - an easier and cost-effective way to utilize a longer wavelength for tilt angle generation and polymerization by using a higher amount of the more conventional main RM which is often easier and cheaper to provide. 5 Moreover, this allows a broader choice of UV lamps as used in the UV1 and UV2 step of the PSA process. Thus, for example, it is possible to use a main RM with an absorption spectrum that shows no or only a small overlap with the emission spectrum of the lamp used in the UV1 step for tilt generation (for example a UV-LED lamp with 365 nm), but shows a strong overlap with 10 the emission spectrum of the lamp used in the UV2 step for complete polymerization (for example a UV B-type lamp). On the other hand, the doping RM has an absorption spectrum that shows a strong overlap with the spectra of both UV lamps used in the UV1 and UV2 steps. In the UV1 step, the doping RM will absorb the UV light emitted from the UV lamp (e.g., the 15 UV-LED lamp) and react not only itself, but will also trigger a part of the main RM to generate a tilt. In the UV2 step, the UV lamp (e.g., the UV B-type lamp) will trigger the main RM to react itself, so that all RMs will be fully reacted in this process. Thereby the amount of residual, unreacted RMs can be kept very low. 20 Preferably, the proportion of the first or main RM is 90% or more, very preferably 95% or more, most preferably 99% or more, of the total amount of all RMs (or the total amount of the polymerizable component B) in the LC medium. Further preferably, the proportion of the second or doping RM is 25 10% or less, very preferably 5% or less, most preferably 0.5% or less, of the total amount of all RMs (or the total amount of the polymerizable component B) in the LC medium. Preferably the weight ratio of main RM to doping RM in the LC medium is 30 from 1:300 to 1:100, more preferably from 1:250 to 1:150. Preferably, the concentration of the first or main RM in the LC medium is from 2.4 to 6.5%, very preferably from 3 to 5.5% by weight. Further preferably, the concentration of the second or doping RM in the LC medium is from 0.01 to 35 0.5%, very preferably from 0.02 to 0.1% by weight. P23167 De - 28 - The total concentration of the polymerizable mesogenic compounds or RMs in the LC medium according to the present invention is preferably from 2.5 to 7%, preferably from 3 to 6%, very preferably from 3.5 to 5.5% by weight. 5 In a preferred embodiment the LC medium contains exactly one first or main RM and exactly one second or doping RM. In another preferred embodiment the LC medium contains two more first or main RMs and / or two or more second or doping RMs. 10 In another preferred embodiment the LC medium does not contain any polymerizable mesogenic compounds other than the first and second RMs. The main RM is preferably selected from the compounds of formula IB and 15 its subformulae. The doping RM is preferably selected from the compounds of formulae IA and IC and their subformulae. Preferably the concentration of the compound(s) of formula IA or IC in the LC medium is lower than the concentration of the compound(s) of formula IB in the LC medium. 20 In a preferred embodiment of the present invention, the LC medium contains one or more, preferably exactly one, compound(s) selected from formula IB and its subformulae and one or more, preferably exactly one, compound(s) selected from formulae IA and IC and their subformulae, and preferably does not contain any further polymerizable compounds. 25 In another preferred embodiment, the concentration of the compound(s) of formula IA and IC and their subformulae in the LC medium is from 0.01 to 0.5%, very preferably from 0.02 to 0.1% by weight, and the concentration of the compound(s) of formula IB and its subformulae in the LC medium is from 30 4.5 to 7.5%, very preferably from 4.5 to 6% by weight. In a preferred embodiment in the compounds of formula IA, IB and / or IC at least one group Sp is a single bond. 35 In another preferred embodiment in the compounds of formula IA, IB and / or IC all groups Sp are a single bond. P23167 De - 29 - In another preferred embodiment in the compounds of formula IA, IB and / or IC at least one group Sp is a single bond and at least one group Sp is different from a single bond. 5 If a group Sp is different from a single bond, it is preferably selected from - (CH2)p1-, -(CH2)p2-CH=CH-(CH2)p3-, -O-(CH2)p1-, -O-CO-(CH2)p1, or -CO-O- (CH2)p1, wherein p1 is 2, 3, 4, 5 or 6, preferably 2 or 3, p2 and p3 are independently of each other 0, 1, 2 or 3 and, if Sp is -O-(CH2)p1-, -O-CO- 10 (CH2)p1or -CO-O-(CH2)p1the O-atom or CO-group, respectively, is linked to the benzene 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 benzene ring. 15 Preferably in the componds of formula IA, IB and IC all polymerizable groups P have the same meaning, and very preferably denote acrylate or methacrylate, most preferably methacrylate. 20 Preferably in the compounds of formula IA a and b are independently of each other 0 or 1. In a preferred embodiment of the invention a+b=1 or 2. Preferred compounds of formula IA are selected from formula IAA: 25 wherein P, Sp, L and r3 have independently of each other one of the 30 meanings given in formula IA or one of their preferred meanings as given above and below. P is preferably acrylate or methacrylate, very preferably methacrylate. Sp is preferably a single bond. R3 is preferably 0, 1 or 2, very preferably 0 or 1. L is preferably F or OCH3. Preferably all groups P in the formulae I and IAA have the same meaning, and very preferably denote 35 methacrylate. P23167 De - 30 - Very preferred compounds of formula I and IAA are selected from the following subformulae: 35 P23167 De - 31 - 5 25 30 35 P23167 De - 32 - P23167 De - 33 - 5 Very preferred are the compounds of formula IA1 and IA2. Preferred compounds of formula IB are selected from the following 10 subformulae: 15 20 P23167 De - 34 - 10 15 20 25 35 P23167 De - 35 -

[0002] P23167 De - 36 - 10 15 20

[0003] P23167 De - 37 - 5 wherein P and L have one of the meanings as given in formula IB, and Sp’ has one of the meanings given for Sp that is different from a single bond. P is preferably acrylate or methacrylate, very preferably methacrylate. Preferably all groups P in the formulae IB-1 to IB-30 have the same meaning, and very 10 preferably denote methacrylate. Sp’ is preferably selected from -(CH2)2-, - (CH2)3-, -(CH2)4-, -O-(CH2)2-, -O-(CH2)3-, -O-CO-(CH2)2 and -CO-O-(CH)2-, wherein the O atom or the CO group is attached to the benzene ring. L is preferably selected from F, CH3, OCH3, OC2H5 andC2H5, very preferably from F and OCH3. 15 Very preferred are the compounds of formula IB-1, IB-2, IB-12, IB-13 and IB- 14 and their subformulae. Most preferred are the compounds of formula IB-1 and IB-13. 20 Very preferred compounds of formula IB are selected from the following subformulae: 25 35 P23167 De - 38 - 5 10 30 P23167 De - 39 - 15 Very preferred are the compounds of formula IB1, IB5 and IB6. 25 Preferred compounds of formula IC are selected from the following subformulae P23167 De - 40 - 25 wherein P, Sp, L, r1, r2 and r3 have independently of each other one of the meanings given in formula IC or one of their preferred meanings as given above and below. Preferably at least one of r1, r2 and r3 is not 0. P is preferably acrylate or methacrylate, very preferably methacrylate. L is preferably selected from F, CH3, OCH3, OC2H5 and C2H5, very preferably 30 from OCH3 or F. Preferably all groups P in the formulae IC and IC-1 to IC-6 have the same meaning, and very preferably denote methacrylate. Very preferred are the compounds of formula IC-1, IC-4 and IC-5. 35 More preferred compounds of formula IC are selected from the following subformulae: P23167 De - 41 - IC-1-1 5 35 P23167 De - 42 - P23167 De - 43 - 35 P23167 De - 44 - P23167 De - 45 - 10 15 20 25 30 35 P23167 De - 46 - 10 15 20 25 30 35 P23167 De - 47 - 35 P23167 De - 48 - P23167 De - 49 - wherein P, Sp and L have one of the meanings as given in formula IC and Sp’ has one of the meanings given for Sp that is different from a single bond. P is preferably acrylate or methacrylate, very preferably methacrylate. Preferably all groups P in the formulae IC-1-1 to IC-6-12 have the same 5 meaning, and very preferably denote methacrylate. Sp’ is preferably 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 benzene ring. L is preferably selected from F, CH3, OCH3, OC2H5and C2H5, very preferably from F and OCH3. 10 Very preferred are the compounds of formula IC-1-1, IC-1-6, IC-4-1, IC-5-1 and their subformulae. Very preferred compounds of formula IC are selected from the following 15 subformulae: P23167 De - 50 - IC4 IC5 IC6 35 P23167 De - 51 - 35 P23167 De - 52 - P23167 De - 53 - 30 35 P23167 De - 54 - 5 35 P23167 De - 55 - 35 P23167 De - 56 - 35 P23167 De - 57 - 35 P23167 De - 58 - IC31 IC32 IC33 35 P23167 De - 59 - 35 P23167 De - 60 - P23167 De - 61 - P23167 De - 62 - P23167 De - 63 - 35 P23167 De - 64 - IC51 IC52 IC53 P23167 De - 65 - Of the compounds of formula IC1 to IC21 with two benzene rings very preferred are the compounds of formula IC1, IC2, IC3, IC8, IC9, IC10, IC15, IC16, IC17. Most preferred are the compounds of formula IC1, IC2, IC3, IC8, IC9 and IB10. 5 Of the compounds of formula IC22 to IC53 with three benzene rings very preferred are the compounds of formula IC22 to IC46. Most preferred are the compounds of formula IC22, IC28, IC29, IC35, IC36, IC40 and IC41. 10 Further preferred are the compounds of formulae IC1 to IC53 wherein one or two of the methacrylate groups are replaced by acrylate groups. Further preferred are the compounds of formulae IC1 to IC53 wherein all methacrylate groups are replaced by acrylate groups. 15 Further preferred compounds of formula IA, IB and IC and their subformulae are selected from the following preferred embodiments, including any combination thereof: - All groups P in the compound have the same meaning, 20 - All groups P in the compound denote methacrylate, - the compounds contain exactly two polymerisable groups (represented by the groups P), - the compounds contain exactly three polymerisable groups 25 (represented by the groups P), - P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate, most preferably methacrylate, 30 - all groups Sp denote single bonds, - at lteast one group Sp is different from a single bond, - Sp, when being different from a single bond, or Sp', is -(CH2)p2-, - (CH2)p2-O-, -(CH2)p2-CO-O-, -(CH2)p2-O-CO-, wherein p2 is 2, 3, 4, 5 or 35 6, and the O-atom or the CO-group, respectively, is connected to the benzene ring, P23167 De - 66 - - L denotes F, Cl, CH3, C2H5, OCH3, OC2H5, SCH3or SC2H5, very preferably F, OCH3or SCH3, - L denotes -CH=CH2, -CH2-CH=CH2, -CH=CH-CH3, -CH=CH-CH=CH2or -C(CH3)=CH2, 5 - L does not denote or contain a group P, - r1, r2, r3 and r4 denote 0 or 1, - r1+r2 is 0, 10 - r1+r2 is 1, - r3 is 0. In another preferred embodiment the LC medium additionally comprises one or more RMs selected from the following formulae: 15 P23167 De - 67 - 15 20 25 30 35 P23167 De - 68 - P23167 De - 69 - M20 5 P23167 De - 70 - in which the individual radicals, on each occurrence identically or differently, 25 and each, independently of one another, have the following meaning: P1, P2, P3a polymerizable group, preferably selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, 30 Sp1, Sp2, Sp3a single bond or a spacer group where, in addition, one or more of the radicals P1-Sp1-, P2-Sp2- and P3-Sp3- may denote Raa, with the proviso that at least one of the radicals P1-Sp1-, P2-Sp2and P3-Sp3- present is different from Raa, 35 preferably –(CH2)p1-, -(CH2)p1-O-, -(CH2)p1-CO-O- or – (CH2)p1-O-CO-O-, wherein p1 is an integer from 1 to 12, P23167 De - 71 - RaaH, F, Cl, CN or straight-chain or branched alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH2groups may each be replaced, independently of one 5 another, by -C(R0)=C(R00)-, -C ^C-, -N(R0)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by F, Cl, CN or P1-Sp1-, particularly preferably straight-chain or branched, 10 optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms (where the alkenyl and alkynyl radicals have at least two C atoms and the branched radicals have at least three C atoms), and wherein 15 Raadoes not denote or contain a group P1, P2or P3, R0, R00H or alkyl having 1 to 12 C atoms, Ryand RzH, F, CH3or CF3, 20 X1, X2, X3-CO-O-, -O-CO- or a single bond, ZM1-O-, -CO-, -C(RyRz)- or -CF2CF2-, 25 ZM2, ZM3-CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2)n-, where n is 2, 3 or 4, L F, Cl, CN or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, 30 alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy hav- ing 1 to 12 C atoms, L’, L” H, F or Cl, 35 k 0 or 1, P23167 De - 72 - r 0, 1, 2, 3 or 4, s 0, 1, 2 or 3, 5 t 0, 1 or 2, x 0 or 1. Very preferred are compounds of formulae M2 and M13, especially direactive 10 compounds containing exactly two polymerizable groups P1and P2. Further preferred are compounds selected from formulae M17 to M29, in particular from formulae M20, M22, M24, M27, especially trireactive compounds containing exactly three polymerizable groups P1, P2and P3. 15 In the compounds of formulae M1 to M29 the group 20 25 wherein L on each occurrence, identically or differently, has one of the meanings given above or below, and is preferably F, Cl, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5or P-Sp-, very preferably F, Cl, CN, CH3, C2H5, OCH3, COCH3, OCF3or P-Sp-, more preferably F, Cl, 30 CH3, OCH3, SCH3, COCH3or OCF3, most preferably F, OCH3.or SCH3. Preferred compounds of formulae M1 to M29 are those wherein P1, P2and P3denote an acrylate, methacrylate, oxetane or epoxy group, very preferably an acrylate or methacrylate group, most preferably a methacrylate group. 35 P23167 De - 73 - Further preferred compounds of formulae M1 to M29 are those wherein Sp1, Sp2and Sp3are a single bond. Further preferred compounds of formulae M1 to M29 are those wherein one 5 of Sp1, Sp2and Sp3is a single bond and another one of Sp1, Sp2and Sp3is different from a single bond. Further preferred compounds of formulae M1 to M29 are those wherein those groups Sp1, Sp2and Sp3that are different from a single bond denote – 10 (CH2)s1-X”-, wherein s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5, and X” is X” is the linkage to the benzene ring and is -O-, -O-CO-, -CO-O, -O-CO- O- or a single bond. Further preferred compounds of formula M are those selected from Table E 15 below, especially those selected from the group consisting of formulae RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-64, RM-74, RM-76, RM-88, RM-92, RM-102, RM-103, RM-109, RM-116, RM-117, RM-120, RM-121, RM-122, RM-139, RM-142, RM-153, RM-155, RM-158 and RM-159. 20 Particularly preferred are LC media comprising one, two or three polymerizable compounds of formula M. Further preferred are LC media comprising two or more direactive 25 polymerizable compounds of formula M, preferably selected from formulae M1 to M16, very preferably selected from formulae M2 and M13. Further preferred are LC media comprising one or more direactive polymerizable compounds of formula M, preferably selected from formulae 30 M1 to M16, very preferably from formulae M2 and M13, and one or more trireactive polymerizable compounds of formula M, preferably selected from formulae M17 to M32, very preferably from formulae M20, M22, M24 and M27. 35 Further preferred are LC media comprising one or more polymerizable compounds of formula M wherein at least one r is not 0, or at least one of s P23167 De - 74 - and t is not 0, very preferably selected from formulae M2, M13, M22, M24, and M27, and wherein L is selected from the preferred groups shown above, most preferably from F, OCH3and SCH3. 5 Further preferred are polymerizable compounds which show absorption in the wavelength range from 320 to 380nm, preferably selected from formula M, very preferably from formulae M1 to M32, most preferably from the group consisting of the above-mentioned formulae from Table E. 10 In another preferred embodiment the LC medium additionally comprises one or more polymerizable compounds having two polymerizable groups selected from formula CM: Wherein P, Sp, L, r1 ad r2 have the meanings given in formulae IA to IC or one of the preferred meanings given above and below. 20 Preferred compounds of formula CM are selected from the following subformulae: wherein P and Sp, L, r1 and r2 have independently of each other one of the meanings given in formula CM or one of their preferred meanings as given 35 above and below, and Sp’ has one of the meanings given for Sp that is different from a single bond. P23167 De - 75 - Preferably at least one of r1 and r2 is not 0. P is preferably acrylate or methacrylate, very preferably methacrylate. 5 Preferably all groups P in the formulae CM, CM-1 and CM-2 have the same meaning, and very preferably denote methacrylate. Sp’ is preferably 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 benzene ring. 10 L is preferably selected from F, CH3, OCH3, OC2H5, C2H5, CH=CH2and C(CH3)=CH2, very preferably from F. Very preferred are the compounds of formula CM-1. 15 More preferred compounds of formula CM are selected from the following subformulae: 35 P23167 De - 76 - 10 CM-2-1 25 30 35 P23167 De - 77 - 10 15 wherein P, Sp’ and L have one of the meanings as given in formula CM-1 and CM-2. P is preferably acrylate or methacrylate, very preferably methacrylate. Preferably all groups P in the formulae CM-1-1 to CM-2-9 have the same meaning, and very preferably denote methacrylate. Sp’ is preferably selected from -(CH2)2-, -(CH2)3-, -(CH2)4-, -O-(CH2)2-, -O-(CH2)3-, - 20 O-CO-(CH2)2 and -CO-O-(CH)2-, wherein the O atom or the CO group is attached to the benzene ring. L is preferably selected from F, CH3, OCH3, OC2H5, C2H5, CH=CH2 and C(CH3)=CH2, very preferably from F and OCH3. Very preferred are the compounds of formula CM-1-1, CM-1-2, CM-1-3, CM- 25 1-4, CM-1-5, CM-1-6 and their subformulae. Most preferred are the compounds of formula CM-1-1. Very preferred compounds of formula CM are selected from the following subformulae: 30 CM1 35 P23167 De - 78 - 35 P23167 De - 79 - P23167 De - 80 - P23167 De - 81 - P23167 De - 82 - Besides the polymerizable compounds or RMs described above, the LC media for use in the LC displays according to the invention comprise an LC mixture (“host mixture”) comprising one or more, preferably two or more LC 5 compounds which are selected from low-molecular-weight compounds that are unpolymerizable, and at least one of which is a compound of formula II. These LC compounds are selected such that they stable and / or unreactive to a polymerization reaction under the conditions applied to the polymerization of the polymerizable compoundsIn another preferred embodiment the LC 10 medium comprises, in addition to the polymerizable compounds of formulae IA, IB and their subformulae, at least one further polymerizable compound. Preferred further polymerizable compounds are selected from Table E below, especially selected from the group consisting of formulae RM-1, RM-4, RM-8, 15 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. 20 The proportion of these further polymerizable compounds in the LC medium is preferably from 0.01 to 5%, more preferably from 0.1 to 2% by weight. The polymerizable compounds can be prepared analogously to processes 25 known to the person skilled in the art and described in standard works of organic chemistry, such as, for example, in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart. 30 For example, acrylic or methacrylic esters can be prepared by esterification of the corresponding alcohols with acid derivatives like, for example, (meth)acryloyl chloride or (meth)acrylic anhydride in the presence of a base like pyridine or triethyl amine, and 4-(N,N-dimethylamino)pyridine (DMAP). Alternatively the esters can be prepared by esterification of the alcohols with 35 (meth)acrylic acid in the presence of a dehydrating reagent, for example according to Steglich with dicyclohexylcarbodiimide (DCC), N-(3- P23167 De - 83 - dimethylaminopropyl)-N’-ethylcarbodiimide (EDC) or N-(3- dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride and DMAP. The invention furthermore relates to an LC medium or LC display as 5 described above, wherein the polymerizable compounds are present in polymerized form. The LC display is preferably a PS-VA, PS-IPS, PS-FFS, or SA-VA display. 10 For the production of PSA or polymer stabilised SA displays, the polymerizable compounds contained in the LC medium are polymerized by in-situ polymerization in the LC medium between the substrates of the LC display, preferably while a voltage is applied to the electrodes. 15 The structure of the displays according to the invention corresponds to the usual geometry for PSA displays, as described in the prior art cited at the outset. Geometries without protrusions are preferred, in particular those in which, in addition, the electrode on the colour filter side is unstructured and only the electrode on the TFT side has slots. Particularly suitable and 20 preferred electrode structures for PS-VA displays are described, for example, in US 2006 / 0066793 A1. A preferred PSA type LC display of the present invention comprises: - a first substrate including a pixel electrode defining pixel areas, the pixel 25 electrode being connected to a switching element disposed in each pixel area and optionally including a micro-slit pattern, and optionally a first alignment layer disposed on the pixel electrode, - a second substrate including a common electrode layer, which may be 30 disposed on the entire portion of the second substrate facing the first substrate, and optionally a second alignment layer, - an LC layer disposed between the first and second substrates and including an LC medium as described above and below, wherein the polymerizable compounds may also be present in polymerized form. 35 P23167 De - 84 - The first and / or second alignment layer controls the alignment direction of the LC molecules of the LC layer. For example, in PS-VA displays the alignment layer is selected such that it imparts to the LC molecules homeotropic (or vertical) alignment (i.e. perpendicular to the surface) or tilted alignment. Such 5 an alignment layer may for example comprise a polyimide, which may also be rubbed, or may be prepared by a photoalignment method. The LC layer with the LC medium can be deposited between the substrates of the display by methods that are conventionally used by display 10 manufacturers, for example the so-called one-drop-filling (ODF) method. The polymerizable component of the LC medium is then polymerized for example by UV photopolymerization. The polymerization can be carried out in one step or in two or more steps. 15 The PSA display may comprise further elements, like a colour filter, a black matrix, a passivation layer, optical retardation layers, transistor elements for addressing the individual pixels, etc., all of which are well known to the person skilled in the art and can be employed without inventive skill. 20 The electrode structure can be designed by the skilled person depending on the individual display type. For example for PS-VA displays a multi-domain orientation of the LC molecules can be induced by providing electrodes having slits and / or bumps or protrusions, or patterned electrodes like for example fishbone electrodes, in order to create two, four or more different tilt 25 alignment directions. Alternatively the display of the present invention can exhibit a single tilt domain. Upon polymerization the polymerizable compounds form a copolymer, which causes a certain tilt angle of the LC molecules in the LC medium. Without 30 wishing to be bound to a specific theory, it is believed that at least a part of the crosslinked polymer, which is formed by the polymerizable compounds, will phase-separate or precipitate from the LC medium and form a polymer layer on the substrates or electrodes, or the alignment layer provided thereon. Microscopic measurement data (like SEM and AFM) have confirmed 35 that at least a part of the formed polymer accumulates at the LC / substrate interface. P23167 De - 85 - The polymerization can be carried out in one step. It is also possible firstly to carry out the polymerization, optionally while applying a voltage, in a first step in order to produce a tilt angle, and subsequently, in a second polymerization 5 step without an applied voltage, to polymerize or crosslink the compounds which have not reacted in the first step ("end curing"). Suitable and preferred polymerization methods are, for example, thermal or photopolymerization, preferably photopolymerization, in particular UV 10 induced photopolymerization, which can be achieved by exposure of the polymerizable compounds to UV radiation. A preferred process of preparing a PSA display includes one or more of the following features, including any combination thereof: 15 - the polymerizable medium is exposed to UV light in the display in a 2-step process, including a first UV exposure step ("UV1 step"), with application of a voltage, to generate the tilt angle, and a second UV exposure step ("UV2 step"), without application of a voltage, to complete polymerization, - for irradiation of the polymerizable medium, a UV radiation source is used 20 which has an emission spectrum at ≥300nm, preferably in the range from 320 to 400 nm. very preferably in the range from 320 to 380 nm, preferably at least in the UV2 step, more preferably both in the UV1 and UV2 step, - for irradiation of the polymerizable medium, as radiation source a UV C-type lamp is used, preferably at least in the UV1 step, more preferably both in the 25 UV1 and UV2 step, - for irradiation of the polymerizable medium, as UV radiation source a UV C- type lamp is used in the UV1 step and a UV B-type lamp is used in the UV2 step. 30 A preferred embodiment of the present invention relates to a process for preparing a PSA display as described above and below, comprising one or more of the following features, including any combination thereof: - the polymerizable LC medium is irradiated by UV light in a 2-step process, including a first UV exposure step ("UV1 step"), with application of a voltage, 35 to generate the tilt angle, and a second UV exposure step ("UV2 step"), without application of a voltage, to complete polymerization, P23167 De - 86 - - the polymerizable LC medium is irradiated by UV light generated by a UV lamp having an intensity of from 0.5 mW / cm2to 10 mW / cm2, preferably in the UV2 step, and optionally also in the UV1 step, - the polymerizable LC medium is irradiated by UV light having a wavelength 5 of preferably >300 nm, - the polymerizable LC medium is irradiated by UV light while a voltage is applied to the electrodes of the display, - irradiation by UV light is carried out using a UV C-type lamp, preferably at least in the UV2 step, more preferably both in the UV1 and UV2 step, 10 - irradiation by UV light is carried out using a UV C-type lamp in the UV1 and a UV B-type lamp in the UV2 step, - irradiation by UV light is carried out using a UV-LED lamp, preferably in the UV1 and / or UV2 step, very preferably both in the UV1 and UV2 step. 15 This preferred process can be carried out for example by using the desired UV lamps or by using a band pass filter and / or a cut-off filter, which are substantially transmissive for UV light with the respective desired wavelength(s) and are substantially blocking light with the respective undesired wavelengths. 20 UV radiation energy is preferably in the range from 2 to 100 J, depending on the production process conditions. The LC medium according to the present invention may additionally comprise 25 one or more further components or additives, preferably selected from the list including but not limited to co-monomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricating agents, dispersing agents, hydrophobing agents, adhesive agents, flow improvers, defoaming agents, deaerators, diluents, reactive diluents, auxiliaries, 30 colourants, dyes, pigments and nanoparticles. The LC medium has preferably a nematic LC phase. In a preferrd embodiment the LC medium contains one or more 35 polymerization initiators. Suitable conditions for the polymerization and suitable types and amounts of initiators are known to the person skilled in the P23167 De - 87 - art and are described in the literature. Suitable for free-radical polymerization are, for example, the commercially available photoinitiators Irgacure651®, Irgacure184®, Irgacure907®, Irgacure369® or Darocure1173® (Ciba AG). If a polymerization initiator is employed, its proportion is preferably 0.001 to 5% 5 by weight, particularly preferably 0.001 to 1% by weight. The polymerizable compounds according to the invention are also suitable for polymerization without an initiator, which is accompanied by considerable advantages, such, for example, lower material costs and in particular less 10 contamination of the LC medium by possible residual amounts of the initiator or degradation products thereof. The polymerization can thus also be carried out without the addition of an initiator. Thus, in another preferred embodiment, the LC medium does not 15 contain a polymerization initiator. In another preferred embodiment the LC medium additionally comprises one or more stabilisers in order to prevent undesired spontaneous polymerization of the RMs, for example during storage or transport. Suitable types and 20 amounts of stabilisers are known to the person skilled in the art and are described in the literature. Particularly suitable are, for example, the commercially available stabilisers from the Irganox® series (Ciba AG), such as, for example, Irganox® 1076. If stabilisers are employed, their proportion, based on the total amount of RMs or the polymerizable component (com- 25 ponent A), is preferably 10-50,000 ppm, particularly preferably 50-5,000 ppm. In a preferred embodiment the LC medium contains one or more chiral dopants, preferably in a concentration from 0.01 to 1% by weight, very preferably from 0.05 to 0.5% by weight. The chiral dopants are preferably 30 selected from the group consisting of compounds from Table C below, very preferably from the group consisting of R- or S-1011, R- or S-2011, R- or S- 3011, R- or S-4011, and R- or S-5011. In another preferred embodiment the LC media contain a racemate of one or 35 more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph. P23167 De - 88 - In another preferred embodiment of the present invention the LC media contain one or more further stabilisers. 5 Preferred stabilisers are selected from the compounds of formula H in which 10 Ar denotes an aromatic or heteroaromatic hydrocarbon group having 4 to 40 C atoms, preferably 6 to 30 C atoms; Sp denotes a spacer group; RSdenotes H, alkyl having 1 to 12 C atoms or alkenyl having 2 to 12 C atoms; 15 –(CH2)zO-, or a single bond; 20 preferab . ly H or O; RS1, RS2, RS3and RS4, identically or differently, denote alkyl having 1 to 6 C atoms, preferably having 1 to 3 C atoms, very preferably CH3; G denotes H or RSor a group ZS-HA; z is an integer from 1 to 6; and 25 q is 3 or 4. The compounds of formula H are described in EP3354710 A1 and EP3354709 A1. Preferred compounds of formula H are selected from the formulae H-1, H-2 30 and H-3: 35 P23167 De - 89 - 35 P23167 De - 90 - in which RHhas the meanings given above and preferably denotes H or O., and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7, and Sp denotes a spacer group, preferably alkylene having 1 to 12 C atoms in which one or more non-adjacent -CH2- groups may be replaced with -O-. 5 Preferred compounds of formula H-1 are those of formula H-1-1: in which RHhas the meanings given above and preferably denotes H or O., and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7. of formula H-1-1 are those of formula H-1-1-1: 30 Preferred compounds of formula H-2 are those of formula H-2-1: 35 P23167 De - 91 - in which RHhas the meanings given above and preferably denotes H or O., 15 and n2, on 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 RSon each occurrence identically or differently, preferably identically, denotes alkyl having 1 to 6 C atoms, preferably n-butyl. 20 Very preferred compounds of formula H-2-1 are those of formula H-2-1-1: 35 Preferred compounds of formula H-3 are selected from the formula H-3-1: P23167 De - 92 - in which Sp and RHhave the meanings given above and RHpreferably 15 denotes H or O., and n is an integer from 0 to 12, preferably 5, 6, 7, 8 or 9, very preferably 7. Further preferred stabilisers are selected from the group consisting of the formulae ST-1 to ST-18: 20 ST-1 25 ST-2 30 ST-3 35 P23167 De - 93 - ST-7 20 ST-8 ST-9 ST-10 P23167 De - 94 - ST-11 5 ST-12 ST-13 20 ST-14 ST-15 P23167 De - 95 - in which 25 RSTdenotes H, an alkyl or alkoxy radical having 1 to 15 C atoms, wherein, in addition, one or more CH2 groups may each be replaced, independently 30 , -O-, -CO-O-, -O-CO- in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, 35 , on each occurrence, identically or differently, denotes P23167 De - 96 - , ZSTeach, independently of one another, denote -CO-O-, -O-CO-, -CF2O- 5 , -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, L1and L2each, independently of one another, denote F, Cl, CH3, CF3or CHF2, 10 p denotes 0, 1 or 2, q denotes 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. 15 Preferred compounds of formula ST are those selected from the formulae ST-3 and in particular: in which n = 1, 2, 3, 4, 5, 6 or 7, preferably n = 3 35 P23167 De - 97 - ST-3c 5 in which n = 1, 2, 3, 4, 5, 6 or 7, preferably n = 1 or 7 ST-8-1 ST-9-1 35 P23167 De - 98 - ST-17 ST-18 In the compounds of the formulae ST-3a and ST-3b, n preferably denotes 3. In the compounds of the formula ST-2a, n preferably denotes 7. 35 P23167 De - 99 - Very preferred stabilisers are selected from the group of the compounds of the formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-3d, ST-3e, ST-8-1, ST-9-1 and ST-12: 35 P23167 De - 100 - ST-12 In another preferred embodiment the LC medium comprises one or more 25 stabilisers selected from Table D below. Preferably the proportion of stabilisers in the LC medium is from 20 to 700 ppm, very preferably from 50 to 300 ppm. 30 In another preferred embodiment the LC medium according to the present invention contains a self alignment (SA) additive, preferably in a concentration of 0.1 to 2.5 %. In a preferred embodiment the SA-VA display according to the present 35 invention does not contain a polyimide alignment layer. In another preferred P23167 De - 101 - embodiment the SA-VA display according to preferred embodiment contains a polyimide alignment layer. Preferred SA additives for use in this preferred embodiment are selected from 5 compounds comprising a mesogenic group and a straight-chain or branched alkyl side chain that is terminated with one or more polar anchor groups selected from hydroxy, carboxy, amino or thiol groups. Further preferred SA additives contain one or more polymerizable groups 10 which are attached, optionally via spacer groups, to the mesogenic group. These polymerizable SA additives can be polymerized in the LC medium under similar conditions as applied for the RMs in the PSA process. Suitable SA additives to induce homeotropic alignment, especially for use in 15 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. In another preferred embodiment an LC medium or a polymer stabilised SA- VA display according to the present invention contains one or more self 20 alignment additives selected from Table F below. In another preferred embodiment the LC medium according to the present invention contains one or more SA additives, preferably selected from formula II or its subformulae or selected from Table F, in a concentration from 0.1 to 25 5%, very preferably from 0.2 to 3%, most preferably from 0.2 to 1.5%. Besides the polymerizable compounds and additives described above, the LC medium for use in the LC displays according to the invention comprises an LC mixture ("host mixture") comprising one or more, preferably two or more LC 30 compounds which are selected from low-molecular-weight compounds that are unpolymerizable, and at least one of which is a compound of formula II. These LC compounds are selected such that they stable and / or unreactive to a polymerization reaction under the conditions applied to the polymerization of the polymerizable compounds. 35 Particularly preferred embodiments of such an LC medium are shown below. P23167 De - 102 - The LC medium or LC host mixture preferably comprises one or more compounds of formula II: II 10 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R21, R22H, straight chain, branched or cyclic alkyl or alkoxy having 1 to 20 15 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl, CN or CF3, preferably alkyl or 25 alkoxy having 1 to 6 C atoms, R0, R00H or alkyl having 1 to 12 C atoms, A1, A2a group selected from the following formulae: 30 35 P23167 De - 103 - 10 15 preferably from formulae A1, A2, A3, A4, A5, A6, A9 and A10, very preferably from formulae A1, A2, A3, A4, A5, A9 and A10, 20 Z1, Z2-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, L1, L2, L3, L4F, Cl, OCF3, CF3, CH3, CH2F or CHF2, preferably F or Cl, very 25 preferably F, Y H, F, Cl, CF3, CHF2 or CH3, preferably H or CH3, very preferably H, 30 LCCH3 or OCH3, preferably CH3, a1 0, 1 or 2, a2 0 or 1. 35 P23167 De - 104 - Preferably the LC medium comprises one or more compounds of formula II selected from the group consisting of compounds of the formulae IIA, IIB, IIC and IID, 5 10 15 20 25 30 in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning: R21, R22H, an alkyl, alkoxy or alkenyl radical having up to 15 C atoms 35 which is unsubstituted or monosubstituted by F, Cl, CN or CF3and P23167 De - 105 - where, in addition, one or more CH2groups in these radicals may 5 in such a way that O- and / or S-atoms are not linked directly to one another, L1to L4F, Cl, CF3or CHF2, 10 Y H, F, Cl, CF3, CHF2or CH3, preferably H or CH3, particularly preferably H, Z1, Z2a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, - OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O, 15 p 0, 1 or 2, and q 0 or 1. 20 Preferred compounds of the formulae IIA, IIB, IIC and IID are those wherein R22denotes an alkyl or alkoxy radical having up to 15 C atoms, and very preferablydenotes (O)CvH2v+1wherein (O) is an oxygen atom or a single bond and v is 1, 2, 3, 4, 5 or 6. 25 Further preferred compounds of the formulae IIA, IIB, IIC and IID are those wherein R21or R22denotes or contains cycloalkyl or cycloalkoxy radical, preferably selected from the group consisting of wherein S1is C1-12-alkylene or C2-12-alkenylene and S2is H, C1-12-alkyl or C2-3512-alkenyl, and very preferably are selected from the group consisting of P23167 De - 106 - Further preferred compounds of the formulae IIA, IIB, IIC and IID are 15 indicated below. In a preferred embodiment the LC medium comprises one or more compounds of the formula IIA selected from the group consisting of the following formulae: 20 IIA-1 25 IIA-2 30 IIA-3 IIA-4 35 P23167 De - 107 - 20 IIA-10 25 IIA-11 IIA-12 30 IIA-13 35 P23167 De - 108 - P23167 De - 109 - 10 15 35 P23167 De - 110 - P23167 De - 111 - 35 P23167 De - 112 - P23167 De - 113 - 10 15 20 P23167 De - 114 - P23167 De - 115 - 5 10 15 35 P23167 De - 116 - 5 10 15 20 in which the index a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2=CH-, 25 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-. Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae IIA-2, IIA-8, 30 IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42 and IIA-43. Preferably, the LC medium comprises one or more compounds of the formula IIA-2 selected from the following subformulae: 35 P23167 De - 117 - 10 IIA-2-3 IIA-2-4 15 IIA-2-5 20 Alternatively, preferably in addition to the compounds of the formulae IIA-2-1 to IIA-2-5, the LC medium comprises one or more compounds of the following formulae: P23167 De - 118 - 15 Further preferably, the LC medium comprises one or more compounds of the formula IIA-10 selected from the following sub-formulae: IIA-10-1 20 25 30 35 P23167 De - 119 - Alternatively, preferably in addition to the compounds of the formulae IIA-10- 1 to IIA-10-5, the LC medium comprises one or more compounds of the following formulae: 20 IIA-10a-5 25 30 In another preferred embodiment the LC medium comprises one or more compounds of the formula IIB selected from the group consisting of he following formulae: 35 P23167 De - 120 - IIB-3 10 IIB-4 15 IIB-5 20 IIB-6 IIB-7 25 IIB-8 30 IIB-9 35 P23167 De - 121 - P23167 De - 122 - 10 IIB-21 15 IIB-22 IIB-23 20 P23167 De - 123 - 10 15 in which alkyl and alkyl* each, independently of one another, denote a 20 straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight- chain alkenyl radical having 2-6 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-. 25 Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae IIB-2, IIB-10 and IIB-16. 30 Preferably, the LC medium comprises one or more compounds of the formula IIB-10 selected from the following sub-formulae: IIB-10-1 35 P23167 De - 124 - 15 Alternatively, preferably in addition, to the compounds of the formulae IIB-10- 1 to IIB-10-5, the LC medium comprises one or more compounds of the formulae IIB-10a-1 to IIB-10a-5: P23167 De - 125 - 5 The proportion of compounds of the formulae IIA and / or IIB in the mixture as a whole is preferably at least 20 % by weight. In another preferred embodiment the LC medium comprises one or more compounds of the formula IIC selected from the formula IIC-1, 10 15 in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, preferably in amounts of 0.5% to 5 % by weight, in particular 1% to 3 % by weight. In another preferred embodiment the LC medium comprises one or more 20 compounds of the formula IID selected from the group consisting of the following formulae: 25 30 35 IID-4 P23167 De - 126 - IID-9 20 IID-10 25 IID-11 35 P23167 De - 127 - P23167 De - 128 - 10 in which alkyl and alkyl* each, independently of one another, denote a straight-chain or branched alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, (O) denotes an oxygen atom or a single bond, alkenyl preferably denotes CH2=CH-, 15 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 may also be monofluorinated, and cycloalkyl and cylcoalkyl* each, independently of one another, denote a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or 20 selected from the group consisting of Particularly preferred LC media according to the invention comprise one or more compounds selected from the formulae IID-4, IID-7, IID-13 and IID-19. 30 Very preferred compounds of the formula IID are selected from the following subformulae: P23167 De - 129 - 35 P23167 De - 130 - 10 30 35 P23167 De - 131 - 35 P23167 De - 132 - 10 wherein v is 1, 2, 3, 4, 5 or 6. Further preferred compounds of the formula IID are selected from the following subformulae: 15 IID-7-1 IID-7-2 20 IID-7-3 25 30 35 P23167 De - 133 - 10 15 20 25 35 P23167 De - 134 - 10 P23167 De - 135 - 15 20 25 wherein v is 1, 2, 3, 4, 5 or 6. Further preferred compounds of the formula IID are selected from the following subformulae: 30 35 P23167 De - 136 - 10 15 20 25 30 35 P23167 De - 137 - 10 15 20 25 P23167 De - 138 - 15 20 25 30 35 P23167 De - 139 - 5 P23167 De - 140 - 5 10 15 20 25 30 35 P23167 De - 141 - 5 10 15 20 wherein v is 1, 2, 3, 4, 5 or 6. Further preferred compounds of the formula IID are selected from the following 25 subformulae: 30 35 P23167 De - 142 - P23167 De - 143 - 10 15 20 P23167 De - 144 - 5 P23167 De - 145 - 5 10 wherein v is 1, 2, 3, 4, 5 or 6. In another preferred embodiment the LC medium comprises one or more 15 compounds of the formula IIE selected from the group consisting of the following formulae: P23167 De - 146 - 35 P23167 De - 147 - 35 P23167 De - 148 - 35 P23167 De - 149 - 35 P23167 De - 150 - 25 35 P23167 De - 151 - P23167 De - 152 - 35 P23167 De - 153 - 5 10 15 20 P23167 De - 154 - 5 25 30 35 P23167 De - 155 - 10 15 in which the index a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl denotes a straight-chain alkenyl radical having 2-6 C atoms, and (O) denotes an oxygen atom or a single bond, and alkenyl preferably denotes CH2=CH-, 20 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-. Particularly preferred LC media according to the invention comprise one or more compounds selected from the group consisting of formulae IIE-2, IIE-8, 25 IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39 and IIE-40. Particularly preferred LC media according to the invention comprise one or more compounds selected from the 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, 30 IID-17, IIE-2, IIE-8, IIE-10, IIE-16, IIE-18, IIE-37, IIE-38, IIE-39, and IIE-40 or their subformulae. In another preferred embodiment the LC medium comprises one or more compounds of formula III which are different from formula IA, 35 P23167 De - 156 - III 5 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R31, R32H, an alkyl, alkoxy or alkenyl radical having up to 15 C atoms 10 which is unsubstituted, monosubstituted by F, Cl, CN or CF3or at least monosubstituted by halogen, where, in addition, one or more CH2in these radicals be -O-, -S-, 15 -C ^C-, -CF2O-, -OCF2-, -OC-O- or -O-CO- in such a way that O atoms are not linked directly to one another, A3a) a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups may be replaced by -O- or -S-, 20 b) a 1,4-phenylene radical, in which one or two CH groups may be replaced by N, or 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- 25 tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl, wherein the radicals a), b) and c) may be mono- or polysubstituted by halogen atoms, 30 n 0, 1 or 2, preferably 0 or 1, Z1-CO-O-, -O-CO-, -CF2O- , -OCF2-, -CH2O-, -OCH2-, -CH2-, - CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2 -, 35 -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C ^C- or a single bond, P23167 De - 157 - L11, L12F, Cl, CF3or CHF2, preferably H or F, most preferably F, W O or S, 5 Y1, Y2H, F, Cl, CF3, CHF2, CH3or OCH3, preferably H, CH3or OCH3, very preferably H. In the compounds of formula III R31and R32are preferably selected frm straight-chain alkyl or alkoxy with 1 to 12, preferably 1 to 7 C atoms, straight- 10 chain alkenyl with 2 to 12, preferably 2 to 7 C atoms and cyclic alkyl or alkoxy with 3 to 12, preferably 3 to 8 C atoms. In a preferred embodiment of the present invention the LC medium comprises one or more compounds of the formula III-1 or III-2, 15 20 in which the occurring groups have the same meanings as given under 25 formula III above and preferably R31and R32each, independently of one another, an alkyl, alkenyl or alkoxy radical having up to 15 C atoms, more preferably one or both of them denote an alkoxy radical and 30 L11and L12each preferably denote F. In another preferred embodiment the LC medium comprises one or more compounds of the formula III-1 selected from the group of compounds of 35 formulae III-1-1 to III-1-10, preferably of formula III-1-6, P23167 De - 158 - P23167 De - 159 - III-1-10, 5 in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms, alkoxy and alkoxy* each, independently of one another, denote 10 a straight-chain alkoxy radical having 1-6 C atoms, and L11and L12each, independently of one another, denote F or Cl, preferably both F. In another preferred embodiment the LC medium comprises one or more compounds of the formula III-2 selected from the group of compounds of 15 formulae III-2-1 to III-2-10, preferably of formula III-2-1, 20 25 30 P23167 De - 160 - 10 III-2-8 III-2-9 15 III-2-10, in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl* each, 25 independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms, alkoxy and alkoxy* each, independently of one another, denote a straight-chain alkoxy radical having 1-6 C atoms, and L11and L12each, independently of one another, denote F or Cl, preferably both F. 30 Very preferred compounds of formula III-2 are selected from the group consisting of the following subformulae: 35 P23167 De - 161 - in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferaby ethoxy or 20 propoxy. Very preferred are the compounds of formula III-2-1-3, III-2-1-4 and III-2-1-5. In another preferred embodiment of the present invention the LC medium 25 comprises one or more compounds of the formula III-3-1 or III-3-2 30 35 P23167 De - 162 - in which L11and L12have the same meanings as given under formula III, (O) 10 denotes O or a single bond, R33denotes alkyl or alkenyl having up to 7 C atoms or a group Cy- CmH2m+1-, 15 R34denotes alkyl or alkenyl having up to 7 C atoms or a group Cy- CmH2m+1-, m and n are, identically or differently, 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, and 20 Cy denotes a cycloaliphatic group having 3, 4 or 5 ring atoms, which is optionally substituted with alkyl or alkenyl each having up to 3 C atoms, or with halogen or CN, and preferably denotes cyclopropyl, cyclobutyl, cyclopentyl or cyclopentenyl. 25 The compounds of formula III3-1 and / or III3-2 are contained in the LC medium either alternatively or additionally to the compounds of formula III, preferably additionally. 30 Very preferred compounds of the formula III3-1 are the following: 35 P23167 De - 163 - in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms. 10 Very preferred compounds of the formula III-3-2 are the following: III-3-2-1 15 III-3-2-2 20 III-3-2-3 in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms. 30 Very preferred compounds of the formula III-3-3 are the following: 35 P23167 De - 164 - in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, 10 preferably ethoxy, propoxy, butoxy or pentoxy, very preferaby ethoxy or propoxy. Very preferred compounds of the formula III-3-4 are the following: 15 in which alkoxy denotes a straight-chain alkoxy radical having 1-6 C atoms, preferably ethoxy, propoxy, butoxy or pentoxy, very preferaby ethoxy or 30 propoxy. In another preferred embodiment of the present invention, the LC medium comprises one or more compounds of the formulae III-4 to III-6, preferably of formula III-5, 35 P23167 De - 165 - 10 in which the parameters have the meanings given above, R11preferably denotes straight-chain alkyl and R12preferably denotes alkoxy, each having 15 1 to 7 C atoms. In another preferred embodiment the LC medium comprises one or more compounds of the formula I selected from the group of compounds of formulae III-7 to III-9, preferably of formula III-8, 20 25 30 in which the parameters have the meanings given above, R11preferably denotes straight-chain alkyl and R12preferably denotes alkoxy each having 1 to 7 C atoms. 35 P23167 De - 166 - In a preferred embodiment of the present invention the LC medium comprises one or more compounds of the formula III-10: in which the occurring groups have the same meanings as given under formula III and preferably 10 R31and R32each, independently of one another, an alkyl, alkenyl or alkoxy radical having up to 15 C atoms, preferably having 1 to 7 C atoms, more preferably an alkoxy radical having 1 to 7 C atoms, or a cyclic alkyl group having 3 to 12 C atoms, preferably 15 cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, very preferably selected from the of Very preferred compounds of formula III-10 are selected from the group 25 consisting of the following formulae: III-10-1 30 III-10-2 35 P23167 De - 167 - 5 10 15 20 25 30 35 P23167 De - 168 - III-10-13 III-10-14 P23167 De - 169 - 10 in which R32denotes alkyl having 1 to 7 C-atoms, preferably ethyl, n-propyl or n-butyl, or alternatively cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl or alternatively –(CH2)nF in which n is 2,3,4, or 5, preferably C2H4F. 15 Preferred compounds of formula III are III-2-1-3, III-2-1-4, III-2-1-5 as well as III- 10-2, and the most preferred are compounds B(S)-2O-O4, B(S)-2O-O5, B(S)- 2O-O6, and COB(S)-2-O4. In a preferred embodiment, the LC medium comprises one or more 20 compounds of the formula IV, 25 in which R41denotes an unsubstituted alkyl radical having 1 to 7 C atoms where, in addition, one or more CH2 be by 30 or an unsubstituted alkenyl radical having 2 to 7 C atoms, preferably an n-alkyl radical, particularly preferably having 2, 3, 4 or 5 C atoms, and R42denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an 35 unsubstituted alkoxy radical having 1 to 6 C atoms, both preferably having 2 to 5 C atoms, an unsubstituted alkenyl radical having 2 to 7 C P23167 De - 170 - atoms, preferably having 2, 3 or 4 C atoms, more preferably a vinyl radical or a 1-propenyl radical and in particular a vinyl radical. The compounds of the formula IV are preferably selected from the group of 5 the compounds of the formulae IV-1 to IV-5, IV-1 10 IV-2 IV-3 15 IV-4 IV-5 20 in which alkyl and alkyl’, independently of one another, denote alkyl having 1 to 7 C atoms, preferably having 2 to 5 C atoms, 25 alkenyl denotes an alkenyl radical having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably 2 C atoms, alkenyl’ denotes an alkenyl radical having 2 to 5 C atoms, preferably 30 having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms, alkoxy denotes alkoxy having 1 to 5 C atoms, preferably having 2 to 4 C atoms, and 35 P23167 De - 171 - cycloalkyl denotes a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl, very selected from the of 5 , 10 Preferably, the LC medium comprises one or more compounds of formula IV- 1 selected from the following subformulae: 15 20 25 30 Further preferably, the LC medium according to the invention comprises one or more compounds of the formulae IV-2-1 and / or IV-2-2: 35 P23167 De - 172 - IV-2-2 5 Further preferably, the LC medium according to the invention comprises one or more compounds of formula IV-3, in particular selected from the following subformulae: 25 IV-3-6 IV-3-7 30 IV-3-8 35 P23167 De - 173 - IV-3-9 5 In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula IV-5 selected from the following subformulae: IV-5-1 10 IV-5-2 15 IV-5-3 IV-5-4 20 IV-5-5 25 IV-5-6 IV-5-7 30 IV-5-8 35 P23167 De - 174 - IV-5-11 10 IV-5-12 15 IV-5-13 IV-5-14 IV-5-15 25 IV-5-16 30 IV-5-17 35 P23167 De - 175 - in which alkyl denotes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or n-pentyl. 30 Further preferably, the LC medium according to the invention comprises one or more compounds of formula IV-4, in particular selected from the following subformulae: IV-4-1 35 P23167 De - 176 - 10 IV-4-5 IV-4-6 In another preferred embodiment the LC medium comprises one or more 20 compounds of formula IV-4 and its subformulae in which one or both of "alkenyl" and "alkenyl' " denote in which , m is 0, 1 or 2, and n is 0, 1 or 2, very preferably selected from compounds of formulae IV-4-3 to IV-4-6. 25 Very preferably, the LC medium according to the invention comprises one or more compounds of the formula IV-1 or its subformulae and / or one or more compounds of the formula IV-3 or its subformulae and / or one or more compounds of the formula IV-4 or its subformulae, and / or one or more 30 compounds of the formula IV-5 or its subformulae, where the total concentration of these compounds is in the range from 1% to 30%. The LC medium according to the invention preferably additionally comprises one or more compounds of the formula IVa, 35 P23167 De - 177 - IVa in which 5 R41and R42each, independently of one another, denote a straight-chain alkyl, alkoxy, alkenyl or alkoxyalkyl radical having up to 12 C atoms, denotes 10 , in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms. 35 The LC medium according to the invention preferably comprises at least one compound of the formula IVa-1and / or formula IVa-2. P23167 De - 178 - The proportion of compounds of the formula IVa in the mixture as a whole is preferably at least 5 % by weight 5 Preferably, the LC medium comprises one or more compounds of formula IVb-1 to IVb-3 IVb-1 10 IVb-2 IVb-3 15 in which alkyl and alkyl* each, independently of one another, denote a straight- 20 chain alkyl radical having 1 to 6 C atoms, and alkenyl and alkenyl* each, independently of one another, denote a straight- chain alkenyl radical having 2 to 6 C atoms. 25 The proportion of the compounds of the formulae IV-1 to IV-3 in the mixture as a whole is preferably at least 3 % by weight, in particular ^ 5 % by weight. Of the compounds of the formulae IVb-1 to IVb-3, the compounds of the formula IVb-2 are particularly preferred. 30 Particularly preferred compounds of the formulae IV-1 to IV-3 are selected from the group consisting of the following formulae 35 P23167 De - 179 - 10 in which alkyl* denotes an alkyl radical having 1 to 6 C atoms and preferably denotes n-propyl. The LC medium according to the invention particularly preferably comprises 15 one or more compounds of the formulae IVb-1-1 and / or IVb-2-3. In another preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula V 20 in which 25 R51and R52independently of one another, denote H, an alkyl, alkoxy or alkenyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by F, Cl, CN or CF3 or at least monosubstituted by halogen, where, in addition, one or more 30 CH2 groups in these radicals may be replaced by -O-, -S-,-C ^C- in such a way that O atoms are not linked directly to one 35 another, and preferably denote alkyl having 1 to 7 C atoms, preferably n-alkyl, particularly preferably n-alkyl having 1 to 5 C P23167 De - 180 - 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, 5 , identically or differently, denote 10 , 15 20 Z51, Z52each, independently of one another, denote -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 25 n is 1 or 2. The compounds of formula V are preferably selected from the compounds of the formulae V-1 to V-17: P23167 De - 181 - in which R1and R2have the meanings indicated for R51and R52above. 35 R1and R2preferably each, independently of one another, denote straight- chain alkyl or alkenyl. P23167 De - 182 - Preferred LC media comprise one or more compounds of the 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 5 LC media according to the invention very particularly preferably comprise the compounds of the formula V-10 and / or IV-1, in particular in amounts of 5 to 30 %. Preferred compounds of the formulae V-10 are indicated below: 10 V-10a V-10b 15 V-10c 20 V-10d The LC medium according to the invention particularly preferably comprises the tricyclic compounds of the formula V-10a and / or of the formula V-10b in 25 combination with one or more bicyclic compounds of the formulae IV-1 The total proportion of the compounds of the formulae V-10a and / or V-10b in combination with one or more compounds selected from the bicyclohexyl compounds of the formula IV-1 is 5 to 40 %, very particularly preferably 15 to 35 %. 30 Particularly preferred LC media comprise the compounds V-10a and / or IV-1-1 V-10a 35 P23167 De - 183 - IV-1-1 The compounds V-10a and IV-1-1 are preferably present in the mixture in a 5 concentration of 5 to 30 %, very preferably 10 to 25 %, based on the mixture as a whole. Preferred LC media comprise at least one compound selected from the group of the compounds 10 in which R1, R2, R41and R42have the meanings indicated above. Preferably in the compounds V-6, V-7 and IV, R1and R41denotes alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms, respectively, and R2and R42denotes alkenyl having 2 to 6 C atoms. Preferably in the compounds V-14, R1denotes alkyl or 25 alkenyl having 1 to 6 or 2 to 6 C atoms and R2denotes alkyl having 1 to 6 C atoms. Further preferably, in the compounds V-7 one or both of R1and R2denotes a cyclic alkyl group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl. 30 In another preferred embodiment the LC medium according to the invention comprises one or more compounds of the formula V-7, preferably selected from the compounds of the formulae V-7a to V-7e: V-7a P23167 De - 184 - 10 V-7e in which alkyl denotes an alkyl group having 1 to 7 C atoms, alkenyl denotes an alkenyl group having 2 to 7 C atoms, and cycloalkyl denotes a cyclic alkyl 15 group having 3 to 12 C atoms, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclopropylalkyl, cyclobutylalkyl or cyclopentylalkyl. Very preferred compounds of the formulae V-7a to V-7e are selected from the compounds of the formulae V7-b1 to V7-b3, V-7d-1 to V-7d-8 and V-7e-1 to 20 V-7e-12. V-7b-1 25 V-7b-2 30 V-7d-1 35 P23167 De - 185 - V-7d-4 10 V-7d-5 15 20 V-7d-7 35 P23167 De - 186 - 35 in which alkyl denotes ethyl, n-propyl, n-butyl or n-pentyl, preferably n-propyl. P23167 De - 187 - Further preferred are compounds of formula V, wherein R51and R52independently of one another denote straight-chain alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms. 5 In a preferred embodiment of the present invention the LC medium additionally comprises one or more compounds of the formulae VI-1 to VI-25, P23167 De - 188 - P23167 De - 189 - 20 VI-23 25 VI-25 30 in which R denotes a straight-chain alkyl or alkoxy radical having 1 to 6 C atoms, (O) 35 denotes -O- or a single bond, X denotes F, Cl, OCF3 or OCHF2, Lxdenotes H or F, m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4. P23167 De - 190 - R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy. 5 X preferably denotes F or OCH3, very preferably F. The LC medium according to the invention preferably comprises the ter- phenyls of the formulae VI-1 to VI-25 in amounts of 2 to 30 % by weight, in particular 5 to 20 % by weight. 10 Particular preference is given to compounds of the formulae VI-1, VI-2, VI-4, VI-20, VI-21, and VI-22 wherein X denotes F. In these compounds, R preferably denotes alkyl, furthermore alkoxy, each having 1 to 5 C atoms. In the compounds of the formula VI-20, R preferably denotes alkyl or alkenyl, in 15 particular alkyl. In the compounds of the formula VI-21, R preferably denotes alkyl. In the compounds of the formulae VI-22 to VI-25, X preferably denotes F. The terphenyls of formula VI-1 to VI-25 are preferably employed in the LC media 20 according to the invention if the ^n value of the mixture is to be ^ 0.1. Preferred LC media comprise 2 to 20 % by weight of one or more terphenyl compounds selected from the group of the compounds of formulae VI-1 to VI-25. In another preferred embodiment of the present invention the LC medium 25 additionally comprises one or more compounds of the formulae VII-1 to VII-9 30 35 P23167 De - 191 - 10 15 20 25 in which R1each, independently of one another, have one of the meanings indicated for R21in formula IIA, and 30 w and x each, independently of one another, denote 1 to 6. Particular preference is given to LC media comprising at least one compound of the formula VII-9. 35 P23167 De - 192 - LC medium comprising one or more substances which contain a tetrahydronaphthyl or naphthyl unit, such as, for example, the compounds of the formulae N-1 to N-5, in which R61and R62each, independently of one another, have the 25 meanings indicated for R21, preferably denote straight-chain alkyl, straight-chain alkoxy or straight-chain alkenyl, and Z61and Z62each, independently of one another, denote -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, 30 -CH2CH2CH=CH-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond. c) LC medium comprising one or more compounds selected from the 35 group of the difluorodibenzochroman compounds of the formula BC, P23167 De - 193 - chromans of the formula CR, and fluorinated phenanthrenes of the formulae PH-1 and PH-2, 20 in which R71and R72each, independently of one another, have the meaning of R21and c is 0, 1 or 2. R71and R72preferably, independently of one another, denote alkyl or alkoxy having 1 to 6 C atoms. 25 The LC medium according to the invention preferably comprises the compounds of the formulae BC, CR, PH-1, PH-2 in amounts of 3 to 20 % by weight, in particular in amounts of 3 to 15 % by weight. 30 Particularly preferred compounds of the formulae BC and CR are the compounds BC-1 to BC-7 and CR-1 to CR-5, BC-1 35 P23167 De - 194 - P23167 De - 195 - 10 in which alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, 15 and alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2 to 6 C atoms. 20 Very particular preference is given to an LC medium comprising one, two or three compounds of the formula BC-2, BF-1 and / or BF-2. d) LC medium comprising one or more indane compounds of the formula 25 In, R81, R82, R83each, independently of one another, denote a straight- 35 chain alkyl, alkoxy, alkoxyalkyl or alkenyl radical having 1 to 6 C atoms, P23167 De - 196 - R82and R83may also denote halogen, preferably F, 10 15 i denotes 0, 1 or 2. Preferred compounds of the formula In are the compounds of the formulae In-1 to In-16 indicated below: 30 35 P23167 De - 197 - 20 25 30 35 P23167 De - 198 - Particular preference is given to the compounds of the formulae In-1, In- 2, In-3 and In-4. 20 The compounds of the formula In and the sub-formulae In-1 to In-16 are preferably employed in the LC media according to the invention in concentrations ≥ 5 % by weight, in particular 5 to 30 % by weight and very particularly preferably 5 to 25 % by weight. 25 e) LC medium comprising one or more compounds of the formulae L-1 to L-8, 30 35 P23167 De - 199 - 10 15 20 25 in which R, R1and R2each, independently of one another, have the meanings indicated for R21in formula IIA above, and alkyl denotes an alkyl radical having 1 to 6 C atoms. The parameter s denotes 1 or 2. 30 The compounds of the formulae L-1 to L8 are preferably employed in concentrations of 5 to 15 % by weight, in particular 5 to 12 % by weight and very particularly preferably 8 to 10 % by weight. 35 f) Preferred LC media additionally comprise one or more compounds of formula IIA-Y P23167 De - 200 - 5 in which R11and R12have one of the meanings given for R21in formula IIA above, and L1and L2, identically or differently, denote F or Cl. Preferred compounds of the formula IIA-Y are selected from the group 10 consisting of the following subformulae P23167 De - 201 - in which, Alkyl and Alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, Alkoxy denotes a 20 straight-chain alkoxy radical having 1-6 C atoms, Alkenyl and Alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-6 C atoms, and O denotes an oxygen atom or a single bond. Alkenyl and Alkenyl* preferably denote CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2- 25 CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-. Particularly preferred compounds of the formula IIA-Y are selected from the group consisting of following subformulae: P23167 De - 202 - in which Alkoxy and Alkoxy* have the meanings defined above and preferably denote methoxy, ethoxy, n- propyloxy, n-butyloxy or n- pentyloxy. 5 g) LC medium comprising one or more quaterphenyl compounds selected from the following formula: wherein 15 RQis alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated, 20 XQis F, Cl, halogenated alkyl or alkoxy having 1 to 6 C atoms or halogenated alkenyl or alkenyloxy having 2 to 6 C atoms, LQ1to LQ6independently of each other are H or F, with at least one of LQ1to LQ6being F. 25 Preferred compounds of formula Q are those wherein RQdenotes straight-chain alkyl with 2 to 6 C-atoms, very preferably ethyl, n-propyl or n-butyl. 30 Preferred compounds of formula Q are those wherein LQ3and LQ4are F. Further preferred compounds of formula Q are those wherein LQ3, LQ4and one or two of LQ1and LQ2are F. Preferred compounds of formula Q are those wherein XQdenotes F or 35 OCF3, very preferably F. P23167 De - 203 - The compounds of formula Q are preferably selected from the following subformulae wherein RQhas one of the meanings of formula Q or one of its preferred 15 meanings given above and below, and is preferably ethyl, n-propyl or n- butyl. Especially preferred are compounds of formula Q1, in particular those wherein RQis n-propyl. 20 Preferably the proportion of compounds of formula Q in the LC medium is from >0 to ≤5% by weight, very preferably from 0.05 to 2% by weight, more preferably from 0.1 to 1% by weight, most preferably from 0.1 to 0.8% by weight. 25 Preferably the LC medium contains 1 to 5, preferably 1 or 2 compounds of formula Q. The addition of quaterphenyl compounds of formula Q to the LC mixture 30 of a poymerizable LC medium enables to reduce ODF mura, whilst maintaining high UV absorption, enabling quick and complete polymerization, enabling strong and quick tilt angle generation, and increasing the UV stability of the LC medium. 35 Besides, the addition of compounds of formula Q, which have positive dielectric anisotropy, to the LC medium with negative dielectric P23167 De - 204 - anisotropy allows a better control of the values of the dielectric constants ^^ ^and ^^, and in particular enables to achieve a high value of the dielectric constant ^^ ^while keeping the dielectric anisotropy ^ ^ constant, thereby reducing the kick-back voltage and reducing image 5 sticking. The LC medium according to the invention preferably comprises - one or more compounds of formula II or its subformulae, preferably of 10 formula IIA and / or IIB, preferably in a total concentration in the range of from 30% to 65%, more preferably from 35% to 60%, particularly preferably from 40 to 55%, and / or 15 - one or more compounds of formula IV, preferably in a total concentration in the range of 35% to 60%, more preferably 40% to 55%, particularly preferably 45% to 50%, and / or 20 - one or more compounds of formula III, preferably of formula III-2, very preferably of formula III-2-1 and / or III-10-2, preferably in a total concentration in the range of 2% to 25%, very preferably 4% to 15%, and / or 25 - one or more compounds of formula V, or its subformulae, preferably of formula V-9, preferably in a total concentration in the range of 0.1% to 30%, more preferably 0.25% to 25%, particularly preferably 0.5% to 20%. In particular, the LC medium comprises 30 - one or more compounds CY-n-Om, in particular CY-3-O4, CY-5-O4 and / or CY-3-O2, preferably in a total concentration in the range of from 5% to 30%, preferably 10% to 20%, based on the mixture as a whole, 35 P23167 De - 205 - - one or more compounds PY-n-Om, in particular PY-1-O2, PY-2-O2 and / or PY-3-O2, preferably in a total concentration in the range of from 5% to 40%, preferably 10% to 30%, based on the mixture as a whole, 5 and / or - one or more compounds CPY-n-Om, in particular CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably in concentrations > 5%, in particular 7% to 20%, based on the mixture as a whole, 10 and / or - one or more compounds CCY-n-Om, preferably CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and / or CCY-5-O2, preferably in concentrations > 3%, in particular 5 to 15%, based on the mixture as a whole, 15 and / or - one or more compounds CPY-n-Om and CY-n-Om, preferably in concentrations of 10 to 80%, based on the mixture as a whole, and / or 20 - 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, preferably in concentrations of 5 to 20%, more preferably 10 to 15% to based on the mixture as a whole, and / or 25 - Y-nO-Om, CCY-n-Om, LY-n-Om, and / or CLY-n-Om, in particular 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, preferably in a total concentration in the range of from 30% to 65%, more preferably from 35% to 60%, based on the mixture as a whole, 30 and / or - one or more compounds CC-n-V, in particular CC-3-V, preferably in a total concentration in the range of from 20 % to 60 %, preferably from 25 % to 50%, very preferably from 35 to 45%, 35 and / or P23167 De - 206 - - one or more compound(s) selected from the group consisting of CCH-13, CCH-23, CCH-34, CCH-35, CCH-301 and CCH-303, preferably in a total concentration of 3 to 40%, preferably 3 to 25% based on the mixture as a whole, 5 and / or - 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, preferably in a total concentration of 3 to 40%, more preferably from 5% to 30% based on 10 the mixture as a whole, and / or - one or more compound(s) CCP-n-m and / or CCP-Vn-m and / or CPP-n-m, preferably selected from the group consisting of CCP-3-1, CCP-V-1, CCP- 15 V2-1 and CPP-3-2, preferably in a total concentration of 4 to 35%, preferably 5 to 25% based on the mixture as a whole, and / or - one or more compound(s) CLP-n-m and / or CLP-Vn-m, preferably selected 20 from the group consisting of CLP-3-1, CLP-3-2 and CLP-V-1, preferably in a total concentration of 1 to 25%, preferably 2 to 15% based on the mixture as a whole, and / or 25 - one or more compounds selected from the group consisting of PYP-n-m, PGIY-n-Om and PGP-n-2V, preferably in a total concentration of 2 to 20%, more preferably 2% to 15%, most preferably 2 to 10%, based on the mixture as a whole, 30 and / or - one or more compound(s) PP-n-m and / or PP-n-nVm, preferably selected from the group consisting of PP-1-3, PP-1-4, PP-1-5, PP-1-2V and PP-1-2V1, preferably in a total concentration of 1 to 15%, preferably 2 to 10% based on the mixture as a whole, 35 and / or P23167 De - 207 - - the compound PPGU-3-F, preferably in a concentration of 0.1% to 3% based on the mixture as a whole. The invention furthermore relates to an electro-optical display having active- 5 matrix addressing, characterised in that it contains, as dielectric, a LC medium 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-posi-VA, PS-TN, polymer stabilised SA-VA or polymer stabilised SA-FFS display. 10 It is advantageous for the LC medium according to the invention to preferably have a nematic phase from ^ -20°C to ^ 70°C, particularly preferably from ^ -30°C to ^ 80°C, very particularly preferably from ^ -40°C to ^ 90°C. 15 The medium according to the invention has a clearing temperature of 70°C or more, preferably of 74°C or more. The expression "have a nematic phase" here means on the one hand that no smectic phase and no crystallisation are observed at low temperatures at the 20 corresponding temperature and on the other hand that clearing still does not occur on heating from the nematic phase. The investigation at low temperatures is carried out in a flow viscometer at the corresponding tem- perature and checked by storage in test cells having a layer thickness cor- responding to the electro-optical use for at least 100 hours. If the storage 25 stability at a temperature of -20°C in a corresponding test cell is 1000 h or more, the medium is referred to as stable at this temperature. At tempera- tures of -30°C and -40°C, the corresponding times are 500 h and 250 h respectively. At high temperatures, the clearing point is measured by con- ventional methods in capillaries. 30 The liquid-crystal mixture preferably has a nematic phase range of at least 60 K and a flow viscosity ^20of at most 30 mm2^ s-1at 20°C. The mixture is nematic at a temperature of -20°C or less, preferably at -30°C 35 or less, very preferably at -40°C or less. P23167 De - 208 - The values of the birefringence ^n in the liquid-crystal mixture are generally between 0.07 and 0.16, preferably between 0.08 and 0.15, very preferably between 0.09 and 0.14. 5 In a preferred embodiment of the present invention, the medium has a birefringence in the range of from 0.090 to 0.110, preferably from 0.095 to 0.105, in particular from 0.100 to 0.105. In another preferred embodiment, the medium according to the invention has 10 a birefringence of 0.120 or more, preferably in the range of from 0.125 to 0.145, more preferably from 0.130 to 0.140. The liquid-crystal mixture according to the invention has a dielectric anisotropy ^ ^ of -1.5 to -8.0, preferably of -2.0 to – 4.0, in particular -2.5 15 to -3.5, The rotational viscosity ^1at 20°C is preferably ^ 120 mPa ^s, in particular ^ 100 mPa ^s. 20 In a preferred embodiment, the rotational viscosity ^1at 20°C is ^ 100mPa ^s, in particular ^ 95 mPa ^s. The liquid-crystal media according to the invention have relatively low values for the threshold voltage (V0). They are preferably in the range from 1.7 V to 25 3.0 V, particularly preferably ^ 2.7 V and very particularly preferably ^ 2.5 V. For the present invention, the term "threshold voltage" relates to the capa- citive threshold (V0), also called the Freedericks threshold, unless explicitly indicated otherwise. 30 In addition, the liquid-crystal media according to the invention have high values for the voltage holding ratio in liquid-crystal cells. In general, liquid-crystal media having a low addressing voltage or threshold 35 voltage exhibit a lower voltage holding ratio than those having a higher addressing voltage or threshold voltage and vice versa. P23167 De - 209 - For the present invention, the term "dielectrically positive compounds" denotes compounds having a ^ ^ > 1.5, the term "dielectrically neutral com- pounds" denotes those having -1.5 ^ ^ ^ ^ 1.5 and the term "dielectrically 5 negative compounds” denotes those having ^ ^ < -1.5. The dielectric ani- sotropy of the compounds is determined here by dissolving 10 % of the compounds in a LC host and determining the capacitance of the resultant mixture in at least one test cell in each case having a layer thickness of 20 µm with homeotropic and with homogeneous surface alignment at 1 kHz. 10 The measurement voltage is typically 0.5 V to 1.0 V, but is always lower than the capacitive threshold of the respective liquid-crystal mixture investigated. All temperature values indicated for the present invention are in °C. 15 The LC media according to the invention are suitable for all VA-TFT (vertical alignment-thin film transistor) applications, such as, for example, VAN (vertically aligned nematic), MVA (multidomain VA), (S)-PVA (super patterned VA), ASV (advanced super view, or axially symmetric VA), PSA (polymer sustained VA) and PS-VA (polymer stabilized VA). They are fur- 20 thermore suitable for IPS (in-plane switching) and FFS (fringe field switching) applications having negative ^ ^. The nematic LC media in the displays according to the invention generally comprise two components A and B, which themselves consist of one or more 25 individual compounds. Component A has significantly negative dielectric anisotropy and gives the nematic phase a dielectric anisotropy of ^ -0.5. Besides one or more com- pounds of the formula I, it preferably comprises the compounds of the for- 30 mulae IIA, IIB and / or IIC, furthermore one or more compounds of the formula IV-1. The proportion of component A is preferably between 45 and 100 %, in par- ticular between 60 and 85 %. 35 P23167 De - 210 - For component A, one (or more) individual compound(s) which has (have) a value of ^ ^ ^ -0.8 is (are) preferably selected. This value must be more negative, the smaller the proportion A in the mixture as a whole. 5 Component B has pronounced nematogeneity and a flow viscosity of not greater than 30 mm2^ s-1, preferably not greater than 25 mm2^ s-1, at 20°C. A multiplicity of suitable materials is known to the person skilled in the art from the literature. 10 Particularly preferred individual compounds in component B are extremely low-viscosity nematic liquid crystals having a flow viscosity of not greater than 18 mm2^ s-1, preferably not greater than 12 mm2^ s-1, at 20°C. 15 Component B is monotropically or enantiotropically nematic, has no smectic phases and is able to prevent the occurrence of smectic phases down to very low temperatures in LC media. For example, if various materials of high nematogeneity are added to a smectic liquid-crystal mixture, the nemato- geneity of these materials can be compared through the degree of sup- 20 pression of smectic phases that is achieved. The mixture may optionally also comprise a component C, comprising compounds having a dielectric anisotropy of ^ ^ ^1.5. These so-called posi- tive compounds are generally present in a mixture of negative dielectric 25 anisotropy in amounts of ^ 20 % by weight, based on the mixture as a whole. Besides the polymerizable compounds, the medium preferably comprises 4 to 15, in particular 5 to 12, and particularly preferably < 10, compounds of the formulae IIA, IIB and / or IIC and optionally one or more compounds of the 30 formula IV-1 and / or III-2. Besides the polymerizable compounds and the compounds of the formulae II, optionally III and optionally IV, other constituents may also be present, for example in an amount of up to 45 % of the mixture as a whole, but preferably 35 up to 35 %, in particular up to 10 %. P23167 De - 211 - The other constituents are preferably selected from nematic or nematogenic substances, in particular known substances, from the classes of the azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclo- hexyl benzoates, phenyl or cyclohexyl cyclohexanecarboxylates, phenyl- 5 cyclohexanes, cyclohexylbiphenyls, cyclohexylcyclohexanes, cyclo- hexylnaphthalenes, 1,4-biscyclohexylbiphenyls or cyclohexylpyrimidines, phenyl- or cyclohexyldioxanes, optionally halogenated stilbenes, benzyl phenyl ethers, tolanes and substituted cinnamic acid esters. 10 The most important compounds which are suitable as constituents of liquid- crystal phases of this type can be characterised by the formula R RR1L-G-E-RR2 15 in which L and E each denote a carbo- or heterocyclic ring system from the group formed by 1,4-disubstituted benzene and cyclohexane rings, 4,4’- disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydronaphthalene, quinazoline and tetra- 20 hydroquinazoline, G denotes -CH=CH- -N(O)=N- -CH=CQ- -CH=N(O)- -C ^C- -CH2-CH2- 25 -CO-O- -CH2-O- -CO-S- -CH2-S- -CH=N- -COO-Phe-COO- -CF2O- -CF=CF- -OCF2- -OCH2- 30 -(CH2)4- -(CH2)3O- or a C-C single bond, Q denotes halogen, preferably chlorine, or -CN, and RR1and RR2each denote alkyl, alkenyl, alkoxy, alkoxyalkyl or alkoxycar- bonyloxy having up to 18, preferably up to 8, carbon atoms, or one of these 35 radicals alternatively denotes CN, NC, NO2, NCS, CF3, SF5, OCF3, F, Cl or Br. P23167 De - 212 - In most of these compounds, RR1and RR2are different from one another, one of these radicals usually being an alkyl or alkoxy group. Other variants of the proposed substituents are also common. Many such substances or also 5 mixtures thereof are commercially available. All these substances can be prepared by methods known from the literature. It goes without saying for the person skilled in the art that the LC medium according to the invention may also comprise compounds in which, for 10 example, H, N, O, Cl and F have been replaced by the corresponding isotopes. The combination of compounds of the preferred embodiments mentioned above with the polymerized compounds described above causes low 15 threshold voltages, low rotational viscosities and very good low-temperature stabilities in the LC media according to the invention at the same time as constantly high clearing points and high HR values, and allows the rapid establishment of a particularly low tilt angle (i.e. a large tilt) in PSA displays. In particular, the LC media exhibit significantly shortened response times, in 20 particular also the grey-shade response times, in PSA displays compared with the LC media from the prior art. The LC media according to the invention may also comprise further additives which are known to the person skilled in the art and are described in the 25 literature, such as, for example, polymerization initiators, inhibitors, stabilisers, surface-active substances or chiral dopants. These may be polymerizable or non-polymerizable. Polymerizable additives are accordingly ascribed to the polymerizable component or component A). Non- polymerizable additives are accordingly ascribed to the non-polymerizable 30 component or component B). Furthermore, it is possible to add to the LC media, for example, 0 to 15% by weight of pleochroic dyes, furthermore nanoparticles, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutyl- 35 ammonium tetraphenylborate or complex salts of crown ethers (cf., for example, Haller et al., Mol. Cryst. Liq. Cryst.24, 249-258 (1973)), for P23167 De - 213 - improving the conductivity, or substances for modifying the dielectric anisotropy, the viscosity and / or the alignment of the nematic phases. Sub- stances of this type are described, for example, in DE-A 2209127, 2240 864, 2321632, 2338281, 2450088, 2637430 and 2853728. 5 The individual components of the above-listed preferred embodiments of the LC media according to the invention are either known or methods for the preparation thereof can readily be derived from the prior art by the person skilled in the relevant art, since they are based on standard methods 10 described in the literature. Corresponding compounds of the formula CY are described, for example, in EP-A-0364538. Corresponding compounds of the formula ZK are described, for example, in DE-A-2636684 and DE-A-3321 373. 15 The LC media which can be used in accordance with the invention are prepared in a manner conventional per se, for example by mixing one or more of the above-mentioned compounds with one or more polymerizable compounds as defined above, and optionally with further liquid-crystalline compounds and / or additives. In general, the desired amount of the com- 20 ponents used in lesser amount is dissolved in the components making up the principal constituent, advantageously at elevated temperature. It is also possible to mix solutions of the components in an organic solvent, for example in acetone, chloroform or methanol, and to remove the solvent again, for example by distillation, after thorough mixing. The invention 25 furthermore relates to the process for the preparation of the LC media according to the invention. It goes without saying to the person skilled in the art that the LC media according to the invention may also comprise compounds in which, for 30 example, H, N, O, Cl, F have been replaced by the corresponding isotopes like deuterium etc. The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts 35 with compounds preferably to be employed and the respective con- centrations thereof and combinations thereof with one another. In addition, P23167 De - 214 - the examples illustrate which properties and property combinations are accessible. For the present invention and in the following examples, the structures of the 5 liquid-crystal compounds are indicated by means of acronyms. Unless stated otherwise, the transformation into chemical formulae is done in accordance with Tables A.1 to A.3 below. All radicals CnH2n+1, CmH2m+1and ClH2l+1or CnH2n, CmH2mand ClH2lare straight-chain alkyl radicals or alkylene radicals, in each case having n, m and l C atoms respectively. Preferably n, m and l 10 are independently of each other 1, 2, 3, 4, 5, 6, or 7. Table A.1 shows the codes for the ring elements of the nuclei of the compound, Table A.2 lists the bridging units, and Table A.3 lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are composed of the codes for the ring elements with optional linking groups, followed by a 15 first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group. Table A.1: Ring elements P23167 De - 215 - P23167 De - 216 - Table A.2: Bridging units P23167 De - 217 - -CH2-O- OI -O-CH2- -CF2-O- QI -O-CF2- Table A.3: End groups 5 On the left individually or in combi- On the right individually or in com- nation bination -n- CnH2n+1- -n -CnH2n+1 -nO- CnH2n+1-O- -On -O-CnH2n+1 10 -m -CmH2m+1-Om -O-CmH2m+1 -V- CH2=CH- -V -CH=CH2 -nV- CnH2n+1-CH=CH- -nV -CnH2n-CH=CH2 -Vn- CH2=CH- CnH2n- -Vn -CH=CH-CnH2n+1 15 -nVm- CnH2n+1-CH=CH-CmH2m- -nVm - CnH2n-CH=CH-CmH2m+1 -N- N≡C- -N -C≡N -S- S=C=N- -S -N=C=S -F- F- -F -F -CL- Cl- -CL -Cl 20 -M- CFH2- -M -CFH2 -D- CF2H- -D -CF2H -T- CF3- -T -CF3 -MO- CFH2O - -OM -OCFH2 -DO- CF2HO - -OD -OCF2H 25 -TO- CF3O - -OT -OCF3 -A- H-C≡C- -A -C≡C-H -nA- CnH2n+1-C≡C- -An -C≡C-CnH2n+1 -NA- N≡C-C≡C- -AN -C≡C-C≡N On the left in combination On the in combination -…m…- -CmH2m- P23167 De - 218 - -…M…- -CFH- -…M…- -CFH- -…D…- -CF2- -…D…- -CF2- -…V…- -CH=CH- -…V…- -CH=CH- -…Z…- -CO-O- -…Z…- -CO-O- 5 -…ZI…- -O-CO- -…ZI…- -O-CO- -…K…- -CO- -…K…- -CO- -…W…- -CF=CF- -…W…- -CF=CF- -…O…- -O- -…O…- -O- 10 in which n and m are each integers, and the three dots "…" are placeholders for other abbreviations from this table. Table B shows illustrative structures of compounds together with their respective abbreviations. 15 Table B In Table B, n, m, k and l are, independently of one another, each an integer, preferably 1 to 9 preferably 1 to 7, k and l may also be 0 and are preferably 0 20 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” preferably is “2V1”. (O)CmH2m+1means CmH2m+1or OCmH2m+1. 25 30 AIK-n-F 35 P23167 De - 219 - 15 20 P23167 De - 220 - 10 15 20 PB-n-m PB-n-Om 25 BCH-nmF 30 P23167 De - 221 - CY-n-Om CY-(c3)-Om P23167 De - 222 - P23167 De - 223 - 10 CCP-n-m 15 CPYP-n-(O)m 25 CCYY-n-(O)m 30 35 P23167 De - 224 - 25 35 P23167 De - 225 - CCZPC-n-m 35 P23167 De - 226 - CCZC-n-m, CH-nm 10 15 20 n- 25 30 CCPC-nm 35 P23167 De - 227 - 10 15 20 25 30 CQIY-n-(O)m 35 P23167 De - 228 - P23167 De - 229 - CCY-1V2-(O)m 10 CCVC-n-V 15 20 25 CLP-n-m 30 CLP-V-n CPP-n-m 35 P23167 De - 230 - P23167 De - 231 - P23167 De - 232 - 5 10 CETNaph-n-Om 25 CK-n-F 30 35 P23167 De - 233 - 15 20 25 COYOICC-n-m 30 35 P23167 De - 234 - COY-n-Om 10 15 20 25 30 D-n0mFF 35 P23167 De - 235 - 10 15 20 25 30 PGP-n-2V 35 P23167 De - 236 - 10 15 20 P23167 De - 237 - 10 15 20 In a preferred embodiment of the present invention, the LC media according to the invention comprise one or more compounds selected from the group consisting of compounds from Table B. 35 P23167 De - 238 - Table C Table C shows possible chiral dopants which can be added to the LC media according to the invention. 5 10 15 CM 21 R / S-811 20 R / S-1011 35 P23167 De - 239 - 5 10 R / S-4011 R / S-5011 The LC media preferably comprise 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, of dopants. The LC 15 media preferably comprise one or more dopants selected from the group consisting of compounds from Table C. Table D 20 Table D shows possible stabilisers which can be added to the LC media according to the invention. Therein n denotes an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and terminal methyl groups are not shown. 35 P23167 De - 240 - 35 P23167 De - 241 - P23167 De - 242 - 15 30 35 P23167 De - 243 - 35 P23167 De - 244 - P23167 De - 245 - P23167 De - 246 - The LC media preferably comprise 0 to 10% by weight, in particular 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight, of stabilisers. The LC media preferably comprise one or more stabilisers selected from the group consisting of compounds from Table D. 5 Table E Table E shows illustrative reactive mesogenic compounds which can be used in the LC media in accordance with the present invention. 10 15 20 RM-4 25 RM-5 RM-6 RM-7 RM-8 35 P23167 De - 247 - 5 RM-9 RM-10 10 RM-11 RM-12 15 RM-13 RM-14 20 RM-15 RM-16 25 RM-17 RM-18 RM-19 35 P23167 De - 248 - 10 RM-23 15 RM-25 20 RM-27 25 RM-29 RM-30 RM-31 35 P23167 De - 249 - 10 RM-35 15 RM-37 RM-39 RM-40 25 RM-41 RM-42 30 35 RM-43 RM-44 P23167 De - 250 - RM-47 15 RM-50 RM-51 30 RM-52 35 P23167 De - 251 - RM-64 RM-65 35 P23167 De - 252 - 20 25 30 35 RM-79 P23167 De - 253 - 5 RM-80 RM-81 RM-82 RM-83 RM-84 20 25 RM-86 RM-87 30 RM-88 RM-89 35 P23167 De - 254 - RM-94 RM-96 30 RM-98 RM-99 35 P23167 De - 255 - 10 15 RM-103 30 35 P23167 De - 256 - RM-104 30 35 RM-109 RM-110 P23167 De - 257 - 10 15 25 35 P23167 De - 258 - 35 P23167 De - 259 - 10 P23167 De - 260 - 15 RM-141 RM-142 30 P23167 De - 261 - RM-143 RM-144 RM-153 RM-154 35 P23167 De - 262 - RM-163 RM-164 35 P23167 De - 263 - RM-167 RM-168 15 20 25 P23167 De - 264 - RM-175 RM-176 10 15 30 In a preferred embodiment, the mixtures according to the invention comprise one or more polymerizable compounds, preferably selected from the polymerizable compounds of the formulae RM-1 to RM-182. Of 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, 35 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- P23167 De - 265 - 147, RM-149, RM-156 to RM-163, RM-169, RM-170 and RM-171 to RM-183 are particularly preferred. Table F 5 Table F shows self-alignment additives for vertical alignment which can be used in LC media for SA-VA and SA-FFS displays according to the present invention together with the polymerizable compounds: 20 25 30 35 P23167 De - 266 - P23167 De - 267 - 30 35 P23167 De - 268 - 5 P23167 De - 269 - 35 P23167 De - 270 - P23167 De - 271 - 5 30 35 P23167 De - 272 - P23167 De - 273 - P23167 De - 274 - P23167 De - 275 - P23167 De - 276 - 35 In a preferred embodiment, the LC media, SA-VA and SA-FFS displays according to the present invention comprise one or more SA additives P23167 De - 277 - selected from formulae SA-1 to SA-48, preferably from formulae SA-14 to SA-48, very preferably from formulae SA-20 to SA-34 and SA-44, in combination with one or more RMs. 5 Examples The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts with compounds preferably to be employed and the respective con- 10 centrations thereof and combinations thereof with one another. In addition, the examples illustrate which properties and property combinations are accessible. In addition, the following abbreviations and symbols are used: 15 V0threshold voltage, capacitive [V] at 20°C, neextraordinary refractive index at 20°C and 589 nm, noordinary refractive index at 20°C and 589 nm, ^n optical anisotropy at 20°C and 589 nm, 20 ^^dielectric permittivity perpendicular to the director at 20°C and 1 kHz, ^^ ^dielectric permittivity parallel to the director at 20°C and 1 kHz, ^ ^ dielectric anisotropy at 20°C and 1 kHz, 25 cl.p., T(N,I) clearing point [°C], ^1rotational viscosity at 20°C [mPa ^s], K1elastic constant, "splay" deformation at 20°C [pN], 30 K2elastic constant, "twist" deformation at 20°C [pN], K3elastic constant, "bend" deformation at 20°C [pN] Kavaverage eleastic constant at 20°C [pN] defined here as 35 LTS low-temperature stability of the phase, determined in test cells, VHR voltage holding ratio. P23167 De - 278 - Unless explicitly noted otherwise, all concentrations in the present application are quoted in per cent by weight and relate to the corresponding mixture as a whole, comprising all solid or liquid-crystalline components, without solvents. 5 Unless explicitly noted otherwise, all temperature values indicated in the present application, such as, for example, for the melting point T(C,N), the transition from the smectic (S) to the nematic (N) phase T(S,N) and the clearing point T(N,I), are quoted in degrees Celsius (°C). M.p. denotes 10 melting point, cl.p. = clearing point. Furthermore, C = crystalline state, N = nematic phase, S = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. All physical properties are and have been determined in accordance with 15 "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status Nov. 1997, Merck KGaA, Germany, and apply for a temperature of 20°C, and ^n is determined at 589 nm and ^ ^ at 1 kHz, unless explicitly indicated otherwise in each case. 20 The term "threshold voltage" for the present invention relates to the capa- citive threshold (V0), also known as the Freedericks threshold, unless explicitly indicated otherwise. In the examples, the optical threshold may also, as generally usual, be quoted for 10% relative contrast (V10). 25 Unless stated otherwise, the process of polymerizing the polymerizable compounds in the PSA displays as described above and below is carried out at a temperature where the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably is carried out at room temperature. 30 Unless stated otherwise, methods of preparing test cells and measuring their electrooptical and other properties are carried out by the methods as described hereinafter or in analogy thereto. The display used for measurement of the capacitive threshold voltage usually 35 consists of two plane-parallel glass outer plates at a separation of 25 µm, P23167 De - 279 - each of which has on the inside an electrode layer and an unrubbed poly- imide alignment layer on top, which effect a homeotropic edge alignment of the liquid-crystal molecules. 5 The PSVA display or PSVA test cell used for measurement of the tilt angles usually consists of two plane-parallel glass outer plates at a separation of ca. 4 µm unless stated otherwise, each of which has on the inside an electrode layer and a polyimide alignment layer on top, where the two polyimide layers are rubbed antiparallel to one another and effect a homeotropic edge 10 alignment of the liquid-crystal molecules. The SAVA display or test cell has the same structure but wherein one or both polyimide layers are omitted. The polymerizable compounds are usually polymerized in the display or test cell by irradiation with UV light of defined intensity for a prespecified time, 15 with a voltage simultaneously being applied to the display (usually 10 V to 30 V alternating current, 1 kHz). The intensity is measured using a standard meter (Hoenle UV-meter high end with UV sensor). 20 The tilt angle is usually determined using the Mueller Matrix Polarimeter “AxoScan” from Axometrics. A low value (i.e. a large deviation from the 90° angle) corresponds to a large tilt here. 25 Unless stated otherwise, the term "tilt angle" means the angle between the LC director and the substrate, and "LC director" means in a layer of LC molecules with uniform orientation the preferred orientation direction of the optical main axis of the LC molecules, which corresponds, in case of calamitic, uniaxially positive birefringent LC molecules, to their molecular long axis. 30 Example 1 For the polymerizable compounds IA1, IB5 and IC41 as used in a PSA display according the present invention and of polymerizable reference 35 compound R1 of prior art the absorption wavelength ^ at an extinction P23167 De - 280 - coefficient of E = 0.5 is measured in a solution in DCM at a concentration of 3g / L. The results are shown in Table 1.1. Table 1.1 - UV Absorption 5 Compound R1 IA1 IB5 IC41 UV absorption wavelength ^ ^ (nm) at E=0.5 320 364 335 359 10 15 20 P23167 De - 281 - From Table 1.1 it can be seen that compounds IA1 and IC41 have a significantly higher absorption wavelength than compound R1, and also a higher absorption wavelength than compound IB5. Compounds IA and IC41 5 are therefore suitable for UV photopolymerization at longer wavelengths, e.g., using a UV B-type lamp, and can be used as doping RMs (or second RMs) in an LC medium and PSA display according to the present invention, while compound IB5 has a lower absorption wavelength and can be used as main RM (or first RM). 10 This allows to use a UV B-type lamp in the UV 2 step, thereby reducing the risk of a decrease in reliability and the appearance of image sticking. Polymerizable Mixtures 15 The nematic LC host mixture N1 is formulated as follows: BCH-32 6.50 % cl.p. 74.7 °C CC-3-V1 8.00 % ^n 0.1039 20 CCH-23 17.00 % ^ ^ -3.0 CCH-34 6.50 % ^^3.4 CCY-3-O1 3.50 % K3 / K1^ 1.07 CCY-3-O2 12.50 % ^^106 mPa s CPY-2-O2 5.50 % V02.43 V 25 CPY-3-O2 10.00 % CY-3-O2 15.50 % PCH-301 4.50 % PP-1-2V1 5.00 % PY-3-O2 5.50 % 30 Polymerizable mixtures P11 and P12 according to the present invention are prepared by adding compound IB5 as main RM and compound IA1 or IC41 as doping RM in a total amount of 5% by weight to LC host mixture N1. 35 For comparison purpose polymerizable reference mixture PC11 is prepared by adding compound R1 to nematic LC host mixture N1, and polymerizable P23167 De - 282 - reference mixture PC12 is prepared by adding compound IB5 to nematic LC host mixture N1, each in a small amount of 0.3 and 0.4%, respectively. The polymerizable mixture compositions are shown in Table 1.2. 5 Table 1.2 – Polymerizable mixture compositions Conc. Host Monomer Total Monomer (wt. %) N1R1 IA1 IB5 IC41Conc. (%)10 PC11 99.7 0.3 - - - 0.3 PC12 99.6 - - 0.4 - 0.4 P11 95.0 - 0.025 4.975 - 5.0 P12 99.2 - - 4.975 0.025 5.0 15 Electrooptical VA test cells with AF glass substrates containing the polymerizable mixtures are exposed to UV light in a two step process, the first step (UV1) for generating a tilt angle and the second step (UV2) for polymerizing any residual monomer that was not polymerized in the first step. In the UV1 step a voltage is applied (0.1V step and curing at DC 15V), while in 20 the UV2 step no voltage is applied. As radiation source a fluorescent UV C- type lamp with a cut-off filter of 313 nm, or a UV B-type lamp, or a UV-LED lamp with an emission wavelength of 365nm is used. For example, a 365nm UV-LED lamp can be advantageously to avoid polymerization of main RM. The UV intensity is checked by UV detector. The other conditions are as 25 follows, unless stated otherwise: UV1 (UV-LED lamp): 5 mW / cm² at room temperature for 10-300s UV2 (C-type lamp): 0.5 mW / cm² at RT, 10-60 mins, or UV2 (B-type lamp): 1.8 mW / cm² at RT, 30-120 min 30 A tilt angle is generated in the test cells after the UV1 step above. Voltage Holding Ratio (VHR) 35 For the VHR measurement the polymerizable LC media are filled in test cells and the monomers are polymerized under the conditions as described above. P23167 De - 283 - The VHR is measured before and after exposure to a UV B-type lamp or a UV-C type lamp used for the PSA process as described above, while applying a voltage of 1 V / 0.6 Hz at 60°C. 5 Light stress usually causes the decrease of VHR in LC mixtures, therefore the smaller the absolute decrease of VHR value after stress, the better performance for display applications. The results are shown in Table 1.3. 10 Table 1.3 – VHR Mixture PC11 PC12 P11 UV Lamp type B B B 15 VHR (%) initial 97.8 97.2 97.5 VHR (%) after 1h UV 96.6 97 96.4 VHR (%) after 2h UV 96.5 95.5 97.1 It can be seen that the polymerizable mixture P11 according to the invention, 20 despite the higher amount of RM, surprisingly shows a higher VHR value after long UV stress than the reference mixtures PC11 and PC12. Residual RM 25 The residual content of unpolymerized RM (in ppm) in the mixture is determined after UV photopolymerization. The smaller the residual monomer content after a given time interval, the faster the polymerization. For this purpose the polymerizable mixtures are filled in test cells and polymerized by UV exposure for varying time intervals at RT using a fluorescent UV C-type 30 lamp with an intensity of 0.5 mW / cm2or UV B-type lamp with intensity 1.8mW / cm2. The UV intensity is both checked by UV detector with 313nm. After photopolymerization for a certain time interval the test cells are opened, and the mixture is dissolved and rinsed out of the test cell with methyl ethyl ketone and analyzed by Ultra Performance Liquid Chromatography (UPLC). 35 The results are shown in Table 1.4. P23167 De - 284 - Table 1.4 – Residual RM Monomer conc. (% PC11 PC12 P11 5 ) Monomer R1 IB5 IA1 IB5 0 0.3000 0.4000 0.025 4.9750 1 h 0.0156 0.0227 0 0 2 h n.d. 0.0064 0 0 10 n.d. = not detectable It can be seen that in the polymerizable mixture P11 according to the invention, despite the higher initial amount of RM, surprisingly polymerization proceeds faster and more complete, with practically no residual RM already 15 after 1 h, compared to reference mixtures PC11 and PC12. Transmittance For the transmittance versus voltage (VT curve) measurements the 20 polymerizable LC mixtures are filled in PSA test cells and the monomers are polymerized under the conditions as described above. The transmittance of the PSA test cells is measured using an Otsuka LCD-5200 between crossed polarizers, upon increasing voltage in steps of 0.1 V. 25 Fig.1 depicts the VT curves for PSA test cells prepared from mixtures PC11, P11 and P12. It can be seen that the PSA test cells according to the invention containing mixture P11 or P12 show a flatter curve than the PSA test cell containing reference mixture PC11. This allows a better control of the grey shades. 30 Response Times For the response time measurement the polymerizable LC mixtures are filled in PSA test cells and the monomers are polymerized under the conditions as 35 described above. The response times for the PSA test cells are measured using an Otsuka LCD-5200 between crossed polarizers upon application of a P23167 De - 285 - square wave voltage. The time for a transmittance change from 10% to 90% is defined as raising time or Ton. The time for a transmittance change from 90% to 10% is defined as falling time or Toff. 5 In the PSA test cells prepared from mixtures P11 and P12 according to the invention the higher concentration of RMs leads to the formation of a polymer network in the LC medium. Therefore, a higher driving voltage is required than in the PSA test cells prepared from mixture PC11 and PC12, where the lower RM concentration only leads to formation of a polymer on the 10 substrates. The response times are therefore determined for the different test cells at similar transmittance. The results are shown in Table 1.5. 15 Table 1.5 – Response Times Response Time (ms) PC11 P11 PC12 P12 6V Ton 12.1 - 11.75 - 6V Toff5.35 - 5.5 - 20 8V Ton- 10.12 - - 8V Toff - 3.6 - - 10V Ton - 8.7 - 9.9 10V Toff - 3.6 - 3.5 25 It can be seen that the test cells using polymerizable mixtures P11 and P12 according to the invention show significantly faster response times than the test cells using reference mixtures PC11 and PC12. In particular the Toff time can be reduced by 30%. 30 Overall, the above results demonstrate that the boost PSA test cells using a polymerizable LC medium according to the invention, which contains a high amount of the main RM IB5 and a low amount of the doping RM IA1 or IC41, show significant improvements like faster response times, higher VHR after UV stress, lower amount of residual monomer, while still allowing good tilt 35 angle generation, compared to the PSA test cells containing the polymerizable reference LC medium PC11 with the RM R1 or the polymerizable reference P23167 De - 286 - LC medium with the RM IB5, each being present in a low amount of 0.3% or 0.4%, respectively, as typically used in conventional PSA displays. Example 2 5 The nematic LC host mixture N2 is formulated as follows: B(S)-2O-O4 5.00 % cl.p. 74.3 B(S)-2O-O5 5.00 % ^n 0.1302 10 BCH-32 9.00 % ne1.625 CC-3-V 15.00 % no1.4948 CC-3-V1 7.50 % ^ ^ ^ -2.9 CC-4-V1 13.00 % ^^ ^3.6 CCP-3-1 10.00 % ^^6.5 15 CLY-3-O2 2.50 % ^^89 CPY-3-O2 2.00 % K115.1 PY-1-O2 12.00 % K315 PY-3-O2 10.00 % K3 / K10.99 V02.42 V 20 Polymerizable mixture P21 according to the present invention is prepared by adding compound IB5 as main RM and compound IA1 as doping RM in a total amount of 5% by weight to LC host mixture N2. 25 For comparison purpose polymerizable reference mixture PC21 is prepared by adding compound IB5 to LC host mixture N2 in a small amount of 0.4%. The polymerizable mixture compositions are shown in Table 2.1. 30 Table 2.1 - Polymerizable mixture compositions Conc. Host Monomer Conc. (%) (wt. %) N1 IA1 IB5 PC21 99.6 - 0.4 35 P21 95.0 0.025 4.975 P23167 De - 287 - Transmission The transmission versus voltage (VT curve) for PSA test cells prepared from mixture PC21 or P21, respectively, is measured as described in Example 1. 5 The VT curves are depicted in Fig.2. It can be seen that the PSA test cell according to the invention containing mixture P21 shows a flatter curve than the PSA test cell containing reference mixture PC21. This allows a better control of the grey shades. 10 Response Times The response times for PSA test cells prepared from mixture PC21 or P21, respectively, are measured as described in Example 1. The results are shown 15 in Table 2.2. Table 2.2 – Response Times Response Time (ms) PC21 P21 20 6V Ton 9.5 - 6V Toff2.46 - 8V Ton- 7.1 8V Toff - 1.92 25 It can be seen that the test cell using polymerizable mixture P21 according to the invention shows significantly faster response times than the test cell using reference mixture PC21. Both the Tonand Tofftime can be reduced by 20-25%. Example 3 30 The nematic LC host mixture N3 is formulated as follows: B(S)-2O-O4 4.50 % cl.p. 74°C B(S)-2O-O5 5.00 % ^n 0.1120 35 BCH-32 6.00 % ne1.6002 CC-3-V 47.50 % no1.4882 P23167 De - 288 - ^ ^ ^ -3.0 ^^ ^3.5 ^^6.6 PY-1-O2 10.00 % ^^74 mPa s 5 K114.2 K314.5 K3 / K11.03 V02.31 V 10 Polymerizable mixture P3 is prepared by adding 4.975% of compound IB5, 0.025% of compound IA1 and 250 ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N1. 20 Example 4 The nematic LC host mixture N4 is formulated as follows B(S)-2O-O4 4.50 % cl.p. 75.7 25 B(S)-2O-O5 5.00 % ^n 0.1232 CC-3-V 28.20 % ne 1.6169 CC-3-V1 8.00 % no 1.4937 CCP-3-1 3.80 % ^ ^ ^ -2.8 CCP-V-1 10.60 % ^ ^ ^ 3.5 30 CPY-2-O2 7.80 % ^ ^ 6.3 CPY-3-O2 12.00 % ^ ^ 78 PP-1-2V1 7.60 % K1 15.0 PY-1-O2 10.00 % K3 16.1 PY-3-O2 3.00 % K3 / K1 1.07 35 V0 2.55 V P23167 De - 289 - Polymerizable mixture P4 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC41 and 0.6% of the SA additive SA23 to the nematic LC host mixture N4. 15 Example 5 The nematic LC host mixture N5 is formulated as follows B(S)-2O-O4 5.00 % cl.p. 74.3 20 B(S)-2O-O5 5.00 % ^n 0.1302 BCH-32 9.00 % ne1.625 CC-3-V 15.00 % no1.4948 CC-3-V1 7.50 % ^ ^ ^ -2.9 CC-4-V1 13.00 % ^^ ^3.6 25 CCP-3-1 10.00 % ^^6.5 CLY-3-O2 2.50 % ^^89 CPY-3-O2 2.00 % K115.1 PY-1-O2 12.00 % K315 PY-3-O2 10.00 % K3 / K10.99 30 PYP-2-3 9.00 % V02.42 V Polymerizable mixture P5 is prepared by adding 4.95% of compound IB5, 0.05% of compound IA1 and 150ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N5. 35 P23167 De - 290 - Example 6 The nematic LC host mixture N6 is formulated as follows 5 CC-3-V1 9.00 % cl.p. 74.6°C CCH-301 3.50 % ^n 0.0984 CCH-34 8.00 % ne1.5804 CCH-35 8.00 % no1.4820 ^ ^ ^ -3.6 10 ^^ ^3.6 ^^7.1 ^^119 mPa.s CY-3-O2 15.50 % K114.1 PCH-301 8.50 % K317.0 15 PY-3-O2 12.50 % K3 / K11.21 V02.31 V Polymerizable mixture P6 is prepared by adding 4.95% of compound IB6 and 0.05% of compound IA1 to the nematic LC host mixture N6. 20 25 The nematic LC host mixture N7 is formulated as follows 30 B(S)-2O-O4 3.50 % cl.p. 74.9°C B(S)-2O-O5 5.00 % ^n 0.1154 BCH-32 7.50 % ^ ^ -2.6 CC-3-V 29.50 % ^ . ^ 74 mPas 35 CC-3-V1 5.50 % K1 ^ 14.5 CCP-3-1 7.00 % K3 14.9 P23167 De - 291 - CCP-V-1 11.50 % ^^ / K34.97 CLY-3-O2 5.00 % CPY-2-O2 4.00 % CPY-3-O2 10.00 % 5 0.50 % PY-2-O2 11.00 % Polymerizable mixture P7 is prepared by adding 4.975% of compound IB1, 0.025% of compound IC41 and 250ppm of the stabilizer ST-3a-1 to the 10 nematic LC host mixture N7. 15 Example 8 The nematic LC host mixture N8 is formulated as follows 20 B(S)-2O-O4 4.50 % cl.p. 74.9°C B(S)-2O-O5 5.00 % ^n 0.1122 B(S)-2O-O6 2.00 % ne 1.5993 CC-3-V 30.00 % no 1.4871 25 CC-4-V1 17.50 % ^ ^ ^ -3.7 CLY-3-O2 8.00 % ^ ^ ^ 3.7 CPY-2-O2 10.00 % ^ ^ 7.4 CPY-3-O2 10.00 % ^ . ^ 85 mPas PY-1-O2 3.00 % K1 14.5 30 PY-2-O2 10.00 % K3 14.2 K3 / K1 0.98 V0 2.07 V Polymerizable mixture P11 is prepared by adding 4.975% of compound IB5 35 and 0.025% of compound IA2 to the nematic LC host mixture N8. P23167 De - 292 - 5 Example 9 The nematic LC host mixture N9 is formulated as follows 10 B(S)-2O-O4 4.00 % cl.p. 74.7 B(S)-2O-O5 5.00 % ^n 0.1122 BCH-32 7.00 % ne1.5977 CC-3-V1 8.00 % no1.4855 15 CC-4-V1 11.00 % ^ ^ ^ -3.8 CCH-34 8.00 % ^^ ^3.9 CCH-35 6.00 % ^^7.7 CCY-3-O2 11.00 % ^^109 mPa.s CPY-2-O2 3.00 % K115.0 20 CPY-3-O2 5.00 % K315.4 CY-3-O2 15.00 % K3 / K10.97 PCH-302 5.00 % V02.13 PPGU-3-F 1.00 % PY-1-O2 4.00 % 25 PY-2-O2 7.00 % Polymerizable mixture P9 is prepared by adding 4.97% of compound IB5, 0.03% of compound IC1 and 150ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N9. 30 35 P23167 De - 293 - IC1 Example 10 10 The nematic LC host mixture N10 is formulated as follows CC-3-V1 8.50 % cl.p. 75.1°C CC-4-V1 19.00 % ^n 0.1123 PY-1-O2 6.00 % K115.2 PY-2-O2 6.00 % K318.3 PY-3-O2 8.00 % K3 / K11.20 V02.29 V 25 Polymerizable mixture P10 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC40 to the nematic LC host mixture N9. 30 35 P23167 De - 294 - IC40 Example 11 15 The nematic LC host mixture N11 is formulated as follows B(S)-2O-O4 2.00 % cl.p. 73.9 B(S)-2O-O5 2.50 % ^n 0.1165 BCH-32 8.00 % ne 1.6084 20 CC-3-V 30.00 % no 1.4919 CC-4-V1 7.00 % ^ ^ ^ -2.7 CCP-3-1 11.00 % ^ ^ ^ 3.6 CLY-3-O2 3.00 % ^ ^ 6.3 CPY-2-O2 2.00 % ^ 79 m . ^ Pas 25 CPY-3-O2 12.00 % K1 14.1 PY-1-O2 11.50 % K3 14.7 PY-2-O2 11.00 % K3 / K1 1.04 V0 2.46 V 30 Polymerizable mixture P14 is prepared by adding 4.95% of compound IB5 and 0.05% of compound IC2 to the nematic LC host mixture N11. 35 P23167 De - 295 - IC2 Example 12 10 The nematic LC host mixture N12 is formulated as follows B(S)-2O-O4 4.50 % cl.p. 75.6°C B(S)-2O-O5 3.00 % ^n 0.1049 15 CC-3-V 51.00 % ne1.5904 CCP-3-1 1.00 % no1.4855 CLY-3-O2 9.00 % ^ ^ ^ -3.1 CPY-2-O2 10.00 % ^^ ^3.5 CPY-3-O2 12.00 % ^^6.6 PY-1-O2 9.50 % ^^7 . 20 2 mPas K114.1 K315.0 K3 / K11.06 V02.34 V 25 Polymerizable mixture P12 is prepared by adding 4.97% of compound IB1, 0.03% of compound IA1 and 250ppm of the stabilizer ST-3b-1 to the nematic LC host mixture N11. 30 35 Example 13 P23167 De - 296 - The nematic LC host mixture N13 is formulated as follows CC-3-V1 9.00 % cl.p. 75.4°C 5 CCH-23 14.00 % ^n 0.1055 CCH-34 6.00 % ne1.5907 CCH-35 6.00 % no1.4852 CCP-3-1 7.00 % ^ ^ ^ -2.8 ^^ ^3.3 10 ^^6.1 ^^102 mPa.s K116.2 PP-1-2V1 8.50 % K317.3 PY-3-O2 12.00 % K3 / K11.07 15 PY-4-O2 1.00 % V02.67 V Polymerizable mixture P13 is prepared by adding 4.95% of compound IB6, 0.05% of compound IC1 and 0.6% of the SA additive SA32 to the nematic LC host mixture N13. Example 14 The nematic LC host mixture N14 is formulated as follows 35 CC-3-V1 9.00 % cl.p. 74.7°C P23167 De - 297 - CCH-23 18.00 % ^n 0.0982 CCH-34 3.00 % ne1.5800 CCH-35 7.00 % no1.4818 PY-3-O2 11.50 % K315.9 10 K3 / K11.07 V02.28 V Polymerizable mixture P14 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC40 and 150ppm of the stabilizer ST-3a-1 to the 15 nematic LC host mixture N14. The nematic LC host mixture N15 is formulated as follows 20 BCH-32 10.00 % CC-3-V1 6.50 % 0.1113 CCH-34 8.00 % ne1.5981 CCH-35 8.00 % no1.4868 25 ^ ^ ^ -3.3 30 PP-1-4 10.00 % K315.3 K3 / K11.06 V02.28 V Polymerizable mixture P15 is prepared by adding 4.97% of compound IB5, 35 0.03% of compound IA1 and 200ppm of the stabilizer ST-3b-1 to the nematic LC host mixture N15. P23167 De - 298 - Example 16 The nematic LC host mixture N16 is formulated as follows 5 CC-3-V1 8.00 % cl.p. 74.6°C CCH-23 15.0 % ^n 0.0899 CCH-34 5.00 % ne1.5694 CCH-35 6.00 % no1.4795 10 CCP-3-1 3.00 % ^ ^ ^ -3.3 CCY-3-O1 8.00 % ^^ ^3.5 CCY-3-O2 10.00 % ^^6.8 CCY-3-O3 6.00 % ^^114 mPa.s CCY-4-O2 6.00 % K113.9 15 CY-3-O2 12.0 % K314.6 CY-3-O4 3.75 % K3 / K11.05 PCH-301 3.00 % V02.22 V PY-3-O2 2.75 % PY-4-O2 6.50 % 20 PYP-2-3 5.00 % Polymerizable mixture P16 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC41 and 0.5% of the SA additive SA-32 to the nematic LC host mixture N16. 25 Example 17 The nematic LC host mixture N17 is formulated as follows 30 B(S)-2O-O4 0.25 % cl.p. 74.6°C BCH-32 4.50 % ^n 0.1034 CC-3-V1 13.00 % ne1.5883 CCH-23 15.00 % no1.4849 CCH-301 1.00 % ^ ^ ^ -2.9 35 CCH-34 2.00 % ^^ ^3.4 CCH-35 0.50 % ^^6.3 P23167 De - 299 - CCY-3-O2 6.50 % ^^103 mPa.s K113.0 K315.3 K3 / K11.18 5 CY-3-O4 0.25 % V02.44 V PCH-301 13.00 % PP-1-2V1 0.50 % PYP-2-3 1.00 % 10 Polymerizable mixture P17 is prepared by adding 04.975% of compound IB5 and 0.025% of compound IA1 to the nematic LC host mixture N17. 15 The nematic LC host mixture N18 is formulated as follows CCH-301 6.00 % cl.p. 109.9°C CCH-303 10.00 % ^n 0.0976 CCH-501 4.00 % ne1.5806 20 no1.4830 CCPC-33 3.00 % ^ ^ ^ -3.6 CCPC-34 3.00 % ^^ ^3.4 ^^7.0 CCY-3-O2 9.50 % ^^233 mPa.s 25 K116.9 CCY-4-O2 8.50 % K319.6 CPY-2-O2 3.00 % K3 / K11.16 CPY-3-O2 12.50 % V02.47 V CY-3-O4 9.50 % 30 PCH-301 11.50 % Polymerizable mixture P18 is prepared by adding 4.975% of compound IB1, 0.025% of compound IC41 and 250ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N18. 35 P23167 De - 300 - The nematic LC host mixture N19 is formulated as follows BCH-32 8.00 % cl.p. 74.6°C 5 ^n 0.1042 CC-4-V1 2.50 % ne1.5897 CCH-301 10.00 % no1.4855 CCH-34 5.00 % ^ ^ ^ -3.1 CCH-35 5.00 % ^^ ^3.5 10 ^^6.6 ^^104 mPa.s K113.7 K315.4 PCH-301 6.50 % K3 / K11.12 15 V02.37 V Polymerizable mixture P19 is prepared by adding 4.96% of compound IB6 and 0.04% of compound IC5 to the nematic LC host mixture N19. IC5 30 The nematic LC host mixture N20 is formulated as follows 35 BCH-32 4.50 % cl.p. 74.8°C CC-3-V 15.00 % ^n 0.1030 P23167 De - 301 - CC-3-V1 7.50 % ne1.5889 CC-4-V1 12.50 % no1.4859 CCP-3-1 7.00 % ^ ^ ^ -3.1 ^^ ^3.6 5 ^^6.8 CCY-4-O2 6.50 % ^^94 mPa.s CY-3-O2 4.50 % K113.8 PY-1-O2 9.50 % K315.4 PY-2-O2 9.00 % K3 / K11.12 10 PY-3-O2 6.50 % V02.35 V Polymerizable mixture P20 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC41 to the nematic LC host mixture N20. 20 CC-3-V1 5.50 % ^n 0.1033 CC-4-V1 20.00 % ne1.5875 CCH-34 2.00 % no1.4842 CCH-35 1.50 % ^ ^ ^ -3.3 CCY-3-1 2.00 % ^^ ^3.6 25 ^^6.9 30 PP-1-2V1 3.50 % V02.29 V PY-1-O2 9.50 % PY-2-O2 9.50 % 35 Polymerizable mixture P21 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC8 to the nematic LC host mixture N21. P23167 De - 302 - IC8 10 Example 22 The nematic LC host mixture N22 is formulated as follows CC-3-V1 7.50 % cl.p. 74.5°C 15 ^n 0.1030 CCH-34 5.00 % ne 1.5861 CCH-35 7.50 % no 1.4831 ^ ^ ^ -3.5 ^ ^ ^ 3.6 20 ^ ^ 7.1 mPa.s 25 V0 2.23 V PY-3-O2 10.50 % Polymerizable mixture P22 is prepared by adding 4.97% of compound IB5, 0.03% of compound IC40 and 250ppm of the stabilizer ST-8-1 to the nematic 30 LC host mixture N22. 35 P23167 De - 303 - 10 Example 23 The nematic LC host mixture N23 is formulated as follows CC-3-V1 7.50 % cl.p. 75°C 15 ^n 0.1041 CCH-301 5.50 % ne 1.5884 CCH-34 5.00 % no 1.4843 CCP-3-1 11.00 % ^ ^ ^ -3.1 ^ ^ ^ 3.6 20 ^ ^ 6.7 CPY-3-O2 11.50 % ^ . ^ 101 mPas CY-3-O2 15.00 % K1 14.0 PY-1-O2 6.50 % K3 15.7 PY-2-O2 7.50 % K3 / K1 1.12 25 V0 2.37 V Polymerizable mixture P23 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC41 and 150ppm of the stabilizer ST-8-1 to the nematic LC host mixture mixture N23. 30 The nematic LC host mixture N24 is formulated as follows 35 CC-3-V1 2.50 % cl.p. 105.9°C CC-4-V1 10.00 % ^ ^ -3.6 P23167 De - 304 - CCH-301 3.00 % CCH-34 4.00 % CCH-35 4.00 % ^ CCP-3-1 6.00 % 5 CCP-3-3 6.00 % CCY-3-O1 4.00 % CCY-3-O2 4.00 % CCY-3-O3 4.00 % CCY-4-O2 4.00 % 10 CCY-5-O2 4.00 % CPY-2-O2 10.00 % CPY-3-O2 10.00 % CY-3-O2 6.50 % CY-3-O4 10.00 % 15 PYP-2-3 5.00 % PYP-2-4 3.00 % Polymerizable mixture P24 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC22 to the nematic LC host mixture N24. 20 IC22 30 Example 25 The nematic LC host mixture N25 is formulated as follows BCH-52 9.00 % cl.p. 105°C 35 CC-3-V1 2.00 % ^ ^ -3.6 CC-4-V1 12.50 % ^^ ^3.4 P23167 De - 305 - CCH-301 2.00 % ^^7.0 CCH-34 3.50 % ^ CCH-35 4.00 % CCP-3-1 7.50 % 5 4.00 % CCY-3-O2 4.00 % CCY-3-O3 4.00 % CCY-4-O2 4.00 % CCY-5-O2 4.00 % 10 CPY-2-O2 10.00 % CPY-3-O2 10.00 % CY-3-O4 12.50 % PY-1-O2 7.00 % 15 Polymerizable mixture P25 is prepared by adding 4.975% of compound IB6 0.025% of compound IC22 to the nematic LC host mixture N25. 20 The nematic LC host mixture N26 is formulated as follows B(S)-2O-O5 0.25 % BCH-32 1.50 % ^n 0.1038 CC-3-V1 8.00 % ne1.5864 25 CC-4-V1 20.00 % no1.4826 CCH-303 1.50 % ^ ^ ^ -3.0 CCH-34 6.00 % ^^ ^3.4 CCH-35 8.00 % ^^6.5 CCY-3-O2 9.50 % ^^99 mPa.s 30 CPY-2-O2 6.00 % K115.6 CPY-3-O2 11.00 % K316.0 CY-3-O2 12.50 % K3 / K11.03 PP-1-2V1 2.75 % V02.44 V PY-1-O2 5.50 % 35 PY-2-O2 4.50 % PY-3-O2 3.00 % P23167 De - 306 - Polymerizable mixture P26 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC41 and 200ppm of the stabilizer ST-12 to the nematic LC host mixture N26. 5 15 Example 27 The nematic LC host mixture N27 is formulated as follows BCH-32 0.50 % cl.p. 74.8°C 20 ^n 0.1036 CC-4-V1 19.50 % ne 1.5884 CCH-301 12.00 % no 1.4848 CCH-34 1.50 % ^ ^ ^ -3.1 CCP-3-1 9.00 % ^ ^ ^ 3.6 25 ^ ^ 6.7 ^ ^ 102 mPa.s CPY-2-O2 3.00 % K1 13.8 CPY-3-O2 11.00 % K3 15.6 CY-3-O2 6.50 % K3 / K1 1.13 30 PY-1-O2 9.00 % V0 2.39 V PY-3-O2 1.00 % Polymerizable mixture P27 is prepared by adding 4.97% of compound IB5 35 and 0.03% of compound IA2 to the nematic LC host mixture N27. P23167 De - 307 - Example 28 The nematic LC host mixture N28 is formulated as follows 5 B-2O-O5 4.00 % cl.p. 74.2°C BCH-32 8.00 % ^n 0.1091 CC-3-V1 9.00 % ne74.2 CCH-301 2.00 % no1.4862 CCH-34 8.00 % ^ ^ ^ -3.1 10 CCH-35 7.00 % ^^ ^3.6 CCP-3-1 8.00 % ^^6.7 CCP-V2-1 5.00 % ^^108 mPa.s CCY-3-O2 10.50 % K114.5 CLY-3-O2 1.00 % K316.5 15 CPY-3-O2 2.50 % K3 / K11.14 CY-3-O2 11.50 % V02.41 V PCH-301 5.50 % PY-3-O2 18.00 % 20 Polymerizable mixture P28 is prepared by adding 4.975% of compound IB1 and 0.025% of compound IC40 to the nematic LC host mixture N28. Example 29 25 The nematic LC host mixture N29 is formulated as follows CC-3-V1 3.00 % cl.p. 74.8°C CCH-301 9.00 % ^n 0.0891 CCH-303 5.00 % ne1.5681 30 CCH-34 9.00 % no1.4790 CCH-35 9.00 % ^ ^ ^ -3.2 CCP-3-1 8.00 % ^^ ^3.5 CCY-3-O2 11.50 % ^^6.7 CCY-5-O2 9.00 % ^^115 mPa.s 35 CPY-3-O2 6.00 % K114.2 CY-3-O2 15.00 % K316.3 P23167 De - 308 - PCH-301 4.50 % K3 / K11.15 PY-3-O2 11.00 % V02.38 V Polymerizable mixture P29 is prepared by adding 4.98% of compound IB5, 5 0.02% of compound IC22 and 100ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N29. 10 The nematic LC host mixture N30 is formulated as follows BCH-32 10.50 % cl.p. 74.5°C CCH-34 9.00 % ^n 0.1090 CCH-35 9.00 % ne1.5953 15 CCP-3-1 8.00 % no1.4863 CCY-3-O2 9.50 % ^ ^ ^ -3.4 CCY-4-O2 5.50 % ^^ ^3.7 CPY-3-O2 5.50 % ^^7.0 CY-3-O2 15.00 % ^^128 mPa.s 20 K114.0 PCH-301 K315.7 PY-3-O2 16.00 % K3 / K11.12 V02.25 V 25 Polymerizable mixture P30 is prepared by adding 4.97% of compound IB6, 0.03% of compound IA1 and 200ppm of the stabilizer ST-9-1 to the nematic LC host mixture N30. 30 35 P23167 De - 309 - Example 31 The nematic LC host mixture N31 is formulated as follows 15 B(S)-2O-O5 4.00 % cl.p. 74.7°C BCH-32 5.00 % ^n 0.1024 CC-3-V1 6.00 % ne1.5885 CCH-34 9.00 % no1.4861 CCH-35 9.00 % ^ ^ ^ -3.2 20 CCP-3-1 8.00 % ^^ ^3.6 CCY-3-O1 6.50 % ^^6.7 CCY-3-O2 9.00 % ^^109 mPa.s CLY-3-O2 1.00 % K113.5 CPY-3-O2 4.50 % K316.5 25 CY-3-O2 13.00 % K3 / K11.22 PCH-301 15.00 % V02.39 V PY-1-O2 8.00 % PY-2-O2 2.00 % 30 Polymerizable mixture P31 is prepared by adding 4.97% of compound IB5 and 0.03% of compound IC29 to the nematic LC host mixture N31. 35 P23167 De - 310 - IC29 The nematic LC host mixture N32 is formulated as follows 15 CCH-301 9.00 % cl.p. 110.9°C CCH-34 9.00 % ^n 0.1022 CCH-35 8.00 % ne 1.5867 CCOC-4-3 3.00 % no 1.4845 20 CCP-3-1 6.00 % ^ ^ ^ -3.0 CCP-3-3 6.00 % ^ ^ ^ 3.3 CCPC-33 3.00 % ^ ^ 6.3 CCY-3-1 3.50 % ^ 199 m . ^ Pas CCY-3-O2 4.50 % K1 18.8 25 CCY-3-O3 6.00 % K3 19.6 CCY-4-O2 6.00 % K3 / K1 1.04 CCY-5-O2 5.00 % V0 2.69 V CPY-2-O2 10.50 % CPY-3-O2 6.50 % 30 CY-3-O2 1.00 % PCH-302 4.00 % PY-2-O2 9.00 % Polymerizable mixture P32 is prepared by adding 4.97% of compound IB5, 35 0.03% of compound IC40 and 250ppm of the stabilizer ST-8-1 to the nematic LC host mixture N32. P23167 De - 311 - Example 33 The nematic LC host mixture N33 is formulated as follows 5 BCH-32 3.00 % cl.p. 109.8°C CCH-301 9.00 % ^n 0.1020 CCH-34 9.00 % ne1.5867 CCH-35 2.50 % no1.4847 10 CCOC-4-3 3.00 % ^ ^ ^ -3.0 CCP-3-1 6.00 % ^^ ^3.3 CCP-3-3 5.00 % ^^6.2 CCY-3-1 3.00 % ^^204 mPa.s CCY-3-O2 6.00 % K118.4 15 CCY-3-O3 6.00 % K320.3 CCY-4-O2 6.00 % K3 / K11.10 CCY-5-O2 6.00 % V02.75 V CPY-2-O2 10.00 % CPY-3-O2 8.50 % 20 CY-3-O2 6.00 % PCH-302 11.00 % Polymerizable mixture P33 is prepared by adding 4.95% of compound IB5, 0.05% of compound IC5 and 0.5% of the SA additive SA32 to the nematic LC 25 host mixture N33. Example 34 The nematic LC host mixture N34 is formulated as follows 30 B(S)-2O-O5 2.00 % cl.p. 74.3°C BCH-32 9.50 % ^n 0.1080 CC-3-V1 6.50 % ne1.5962 CCH-301 8.50 % no1.4882 35 CCH-34 3.00 % ^ ^ ^ -3.3 CCP-3-1 9.50 % ^^ ^3.7 P23167 De - 312 - CCY-3-O1 6.50 % ^^7.0 CCY-5-O2 9.50 % ^^121 mPa.s K112.9 K315.9 5 K3 / K11.23 PCH-301 5.00 % V02.31 V PCH-302 6.50 % PY-2-O2 11.50 % 10 Polymerizable mixture P34 is prepared by adding 4.97% of compound IB1, 0.03% of compound IA1 and 150ppm of the stabilizer ST-3b-1 to the nematic LC host mixture N34. 15 The nematic LC host mixture N35 is formulated as follows B(S)-2O-O4 3.00 % cl.p. 74.9°C B(S)-2O-O5 5.00 % ^n 0.1154 20 BCH-32 7.00 % ^ ^ -2.7 CC-3-V 29.50 % ^^77 mPa.s CC-3-V1 9.00 % K1^ 14.3 CCP-3-1 11.00 % K314.9 CCP-3-3 2.00 % ^^ / K35.17 25 CLY-3-O2 2.00 % CPY-2-O2 6.50 % CPY-3-O2 5.50 % PY-1-O2 10.50 % PY-2-O2 9.00 % 30 Polymerizable mixture P35 is prepared by adding 4.97% of compound IB5 and 0.03% of compound IC35 to the nematic LC host mixture N35. 35 P23167 De - 313 - IC35 Example 36 10 The nematic LC host mixture N36 is formulated as follows BCH-32 2.00 % cl.p. 74.7 °C 22.50 % ^n 0.1039 15 ^ ^ -3.0 20 CPY-3-O2 12.50 % CY-3-O2 15.50 % CY-3-O4 4.00 % PCH-301 7.00 % PP-1-2V1 1.50 % 25 PYP-2-3 3.00 % Polymerizable mixture P36 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC41 to the nematic LC host mixture N36. The nematic LC host mixture N37 is formulated as follows CY-3-O4 12.00 % cl.p. 77°C 35 PY-3-O2 9.00 % ^n 0.088 CPY-3-O2 12.00 % ^ ^ -3.1 P23167 De - 314 - CCOY-2-O2 8.00 % CCY-5-O2 10.00 % ^ CC-3-V 20.00 % CCH-32 30.00 % 5 Polymerizable mixture P37 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC35 and 0.6% of the SA additive SA23 to the nematic LC host mixture N37. 10 Example 38 The nematic LC host mixture N38 is formulated as follows CY-3-O4 12.00 % cl.p. 77°C 15 PY-3-O2 9.00 % ^n 0.088 CPY-3-O2 12.00 % ^ ^ -3.1 CCOY-2-O2 8.00 % CCY-5-O2 10.00 % ^ CC-3-V 20.00 % 20 CCH-32 30.00 % Polymerizable mixture P38 is prepared by adding 4.975% of compound IB6 and 0.025% of compound IC41 to the nematic LC host mixture N38. The nematic LC host mixture N39 is formulated as follows CCH-32 10.00 % cl.p. 86°C 30 COY-3-O2 10.00 % ^n 0.105 COY-3-O1 10.00 % ^ ^ -5.9 CCOY-2-O2 9.00 % CCY-3-O1 7.00 % ^ CCY-3-O2 6.00 % 35 CCY-4-O2 6.00 % CPY-5-O2 8.00 % P23167 De - 315 - CPY-3-O1(c3) 10.00 % CPY-2-O2 10.00 % CY-3-O2 7.00 % CY-3-O4 7.00 % 5 Polymerizable mixture P39 is prepared by adding 4.975% of compound IB5, 0.025% of compound IA1 and 150ppm of the stabilizer ST-3d to the nematic LC host mixture N39. 10 15 Example 40 The nematic LC host mixture N40 is formulated as follows CCH-32 11.00 % cl.p. 79°C 20 CC-3-V 10.00 % ^n 0.112 PP-5-O2 5.00 % ^ ^ -4.3 COY-3-O2 8.00 % COY-3-O1 7.00 % ^ CCOY-2-O2 13.00 % 25 CPY-(c5)-O2 7.00 % CPY-3-O2 10.00 % CPY-2-O2 10.00 % PY-3-O2 10.00 % CCP-3-1 2.00 % 30 CCP-V-1 4.00 % CCP-V2-1 4.00 % Polymerizable mixture P40 is prepared by adding 4.97% of compound IB5 and 0.03% of compound IC41 to the nematic LC host mixture N40. 35 P23167 De - 316 - The nematic LC host mixture N41 is formulated as follows CY-5-O2 11.00 % cl.p. 60°C 5 PY-3-O2 9.00 % ^n 0.097 COY-3-O2 17.00 % ^ ^ -2.8 B(S)-(c5)1O-O4 4.00 % PP-1-5 10.00 % ^ CC-3-V1 26.00 % 10 CCH-32 5.00 % CCP-3-1 12.00 % BCH-32 6.00 % Polymerizable mixture P41 is prepared by adding 4.975% of compound IB5, 15 0.025% of compound IC35 and 250ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N41. 20 The nematic LC host mixture N42 is formulated as follows CCH-23 16.50 % cl.p. 75°C CCH-34 3.00 % ^n 0.112 PCH-301 15.00 % ^ ^ -3.0 25 PP-1-3 9.00 % BCH-32 8.00 % ^ COY-3-O1 8.50 % CCOY-3-O2 17.00 % CPY-2-O2 6.50 % 30 CPY-3-O2 8.00 % CPY-3-O4 8.50 % Polymerizable mixture P42 is prepared by adding 4.97% of compound IB5 and 0.03% of compound IC29 to the nematic LC host mixture N42. 35 P23167 De - 317 - The nematic LC host mixture N43 is formulated as follows CCH-23 12.00 % cl.p. 111°C 5 CCH-34 8.00 % ^n 0.097 CCH-35 7.00 % ^ ^ -3.1 PCH-301 8.00 % CCP-3-1 7.00 % ^ CCP-3-3 4.00 % 10 BCH-32 5.00 % CCOY-2-O2 15.00 % CCOY-3-O2 15.00 % CPY-2-O2 5.00 % CPY-3-O2 5.00 % 15 CPY-3-O3 5.00 % CPY-3-O4 4.00 % Polymerizable mixture P43 is prepared by adding 4.975% of compound IB1 and 0.025% of compound IC41 to the nematic LC host mixture N43. 20 The nematic LC host mixture N44 is formulated as follows 25 CC-3-V 32.00 % cl.p. 74°C PP-1-3 11.00 % ^n 0.104 CCP-3-1 8.00 % ^ ^ -2.9 CY-5-O2 2.00 % COY-3-O1 11.50 % ^ 30 CCY-3-O2 11.50 % CPY-2-O2 7.00 % CPY-3-O2 8.00 % CPY-3-O4 9.00 % 35 Polymerizable mixture P44 is prepared by 4.975% of compound IB6 and 0.025% of compound IA1 to the nematic LC host mixture N44. P23167 De - 318 - Example 45 The nematic LC host mixture N45 is formulated as follows 5 CCH-23 21.50 % cl.p. 75°C CCH-34 9.50 % ^n 0.103 PP-1-3 13.50 % ^ ^ -2.8 CCP-3-1 6.00 % 10 COY-3-O1 11.50 % ^ CCOY-3-O2 14.00 % CPY-2-O2 7.00 % CPY-3-O2 8.00 % CPY-3-O4 9.00 % 15 Polymerizable mixture P45 is prepared by adding 4.95% of compound IB5, 0.05% of compound IC5 and 200ppm of the stabilizer ST-3e to the nematic LC host mixture N45. 25 Example 46 The nematic LC host mixture N46 is formulated as follows CEY-3-O2 7.00 % cl.p. 89°C 30 CCY-3-O2 8.00 % ^n 0.115 CCOY-3-O2 5.00 % ^ ^ -1.9 CLY-2-O2 8.00 % CAIY-3-O2 3.00 % ^ CAIY-5-O2 4.00 % 35 PYP-2-3 7.00 % PYP-2-4 7.00 % P23167 De - 319 - CC-4-V 15.00 % CC-3-V1 6.00 % CC-1-2V1 6.00 % CC-3-2V1 4.00 % 5 5.00 % PP-1-2V1 5.00 % CCP-3-1 6.00 % CBC-33F 4.00 % 10 Polymerizable mixture P46 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC22 and 200ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N46. Example 47 15 The nematic LC host mixture N47 is formulated as follows B(S)-2O-O5 2.00 % cl.p. 74°C BCH-32 9.50 % ^n 0.108 20 CCP-3-1 9.50 % ^ ^ -3.6 CCY-3-O1 6.50 % CCY-5-O2 9.50 % ^ CLY-3-O2 1.00 % CPY-3-O2 5.50 % 25 CC-3-V1 6.50 % CCH-301 8.50 % CCH-34 3.00 % COY-3-O2 15.50 % PCH-301 5.00 % 30 PCH-302 6.50 % PY-2-O2 11.50 % Polymerizable mixture P47 is prepared by adding 4.975% of compound IB5, 0.025% of compound IC41 and 200ppm of the stabilizer ST-3d to the nematic 35 LC host mixture N47. P23167 De - 320 - Example 48 The nematic LC host mixture N48 is formulated as follows 5 B(S)-2O-O4 4.0 % cl.p. 75°C B(S)-2O-O4 4.0 % ^n 0.114 BCH-32 7.5 % ne1.606 CC-3-V 25.75 % no1.492 CC-3-V1 10.0 % ^ ^ ^ -2.6 10 CCP-3-1 13.0 % ^^ ^3.6 CCP-3-3 3.25 % ^^6.1 CLY-3-O2 2.0 % K113.7 CPY-2-O2 9.5 % K314.2 PY-2-O2 11.0 % 15 PY-2-O1 10.0 % Polymerizable mixture P48 is prepared by adding 4.975% of compound IB5, 0.025% of compound IA1 and 250ppm of the stabilizer ST-3e to the nematic LC host mixture N48. 20 Example 49 The nematic LC host mixture N49 is formulated as follows 25 BCH-32 7.50 % ^n 0.1105 CCH-34 8.00 % ne1.5970 CCH-35 8.00 % no1.4865 CCY-3-O2 12.00 % ^ ^ ^ -3.3 30 ^^ ^3.5 CPY-3-O2 11.00 % ^^6.8 CY-3-O2 12.00 % ^^130 mPa.s CY-5-O2 13.00 % K114.2 PCH-301 4.00 % K315.4 35 PP-1-4 8.50 % K3 / K11.08 V02.28 V P23167 De - 321 - Polymerizable mixture P49 is prepared by adding 4.97% of compound IB6, 0.03% of compound IC1 and 250ppm of the stabilizer ST-3b-1 to the nematic LC host mixture N49. 5 The nematic LC host mixture N50 is formulated as follows 10 B(S)-2O-O4 4.50 % cl.p. 75.5°C B(S)-2O-O5 5.00 % ^n 0.1120 BCH-32 6.00 % ne1.6001 CC-3-V 30.00 % no1.4881 CC-3-V1 8.00 % ^ ^ ^ -4.1 15 CCY-3-O1 7.50 % ^^ ^3.8 CCY-3-O2 11.00 % ^^8.0 CLY-3-O2 8.00 % ^^92 mPa.s PY-1-O2 10.50 % K114.8 PY-2-O2 9.50 % K315.7 20 K3 / K11.06 V02.06 V Polymerizable mixture P50 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IC41 to the nematic LC host mixture N50. 25 The nematic LC host mixture N51 is formulated as follows 30 B(S)-(c5)1O-O4 4.50 % cl.p. 74.7°C B(S)-2O-O5 5.00 % ^n 0.1120 B(S)-2O-O6 2.00 % ^ ^ -3.6 CC-3-V 30.00 % ^^ ^3.7 CC-4-V1 17.50 % ^^^ 7.3 35 CLY-3-O2 8.00 % ^^88 mPa.s CPY-2-O2 10.00 % K114.2 P23167 De - 322 - CPY-3-O2 10.00 % K314.0 PY-1-O2 3.00 % V02.09 V PY-2-O2 10.00 % 5 Polymerizable mixture P51 is prepared by adding 4.97% of compound IB5, 0.03% of compound IC40 and 250ppm of the stabilizer ST-3a-1 to the nematic LC host mixture N51. 10 Example 52 The nematic LC host mixture N52 is formulated as follows 15 B(S)-(c3)1O-O4 4.50 % cl.p. 75.4°C B(S)-2O-O5 3.00 % ^n 0.1046 CC-3-V 51.00 % CCP-3-1 1.00 % CLY-3-O2 9.00 % 20 CPY-2-O2 10.00 % CPY-3-O2 12.00 % PY-1-O2 9.50 % 25 Polymerizable mixture P52 is prepared by adding 4.975% of compound IB5 and 0.025% of compound IA1 to the nematic LC host mixture N52. 30 35

Claims

P23167 De - 323 - Claims 1. An LC display of the PSA mode, characterized in that it comprises an LC medium comprising from 2.5 to 7%, preferably from 3 to 6%, very 5 preferably from 3.5 to 5.5%, of one or more RMs, wherein at least one of these RMs has an absorption edge in the wavelength range from 300 to 340 nm, preferably from 320 to 340 nm.

2. The LC display according to Claim 1, characterized in that the LC 10 medium comprises a first RM and a second RM, wherein the first RM has an absorption edge in the wavelength range from 320 to 400 nm, preferably from 320 to 380 nm, and the second RM has an absorption edge at a longer wavelength than the first RM, and preferably the concentration of the second RM is lower than the concentration of the 15 first RM.

3. The LC display according to Claim 2, characterized in that the first RM has an absorption edge in the wavelength range from 300 to 340 nm, preferably from 320 to 340 nm, and the second RM has an absorption 20 edge in the wavelength range from 330 to 400 nm, very preferably from 330 to 380 nm, most preferably from 340 to 370 nm.

4. The LC display according to Claim 2 or 3, characterized in that the concentration of the first RM is from 2.4 to 6.5%, very preferably from 25 3.5 to 5.5% by weight, and the concentration of the second RM in the LC medium is from 0.01 to 0.5%, very preferably from 0.02 to 0.1% by weight.

5. The LC display according to one or more of Claims 1 to 4, characterized 30 in that the RMs are selected from the group consisting of the following formulae:P23167 De - 324 -10 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings Aa, Abphenylene-1,4,-diyl or naphthalene,2-6-diyl which is optionally 15 substituted by one or more groups L, Za, Zb-CH=CH-, -CF=CF-, -C ^C- or a single bond, preferably a single bond, 20 P a polymerizable group, Sp a spacer group that is optionally substituted by one or more groups P, or a single bond, 25 L F, Cl, -CN or straight chain, branched or cyclic alkyl having 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- ,in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H atoms 35 are each optionally replaced by P, F or Cl,P23167 De - 325 - R0, R00H or alkyl having 1 to 12 C atoms, a, b 0, 1 or 2, preferably 0 or 1, 5 k 0 or 1, r1, r2 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 0 or 1, r3 0, 1, 2 or 3, preferably 0 or 1. 10 6. The LC display according to Claim 5, characterized in that the compounds of formula IA are selected from the formula IAA:wherein P, Sp, L and r1 have independently of each other one of the meanings given in Claim 5. 20 7. The LC display according to Claim 5 or 6, characterized in that the compounds of formula IC are selected from the following subformulae:P23167 De - 326 - 51015wherein P, Sp, L, r1, r2 and r3 have independently of each other one of 25 the meanings given in Claim 5.

8. The LC display according to one or more of Claims 5 to 7, characterized in that the compounds of formula IB are selected from the following subformulae:P23167 De - 327 -1015P23167 De - 328 -10IB-12P23167 De - 329 -P23167 De - 330 -10152025 wherein P, Sp and L have the meanings given in claim 5 or 6, and Sp’ has one of the meanings given for Sp that is different from a single bond.

9. The LC display according to one or more of Claims 1 to 6, characterized 30 in that the LC medium comprises one or more compounds of formula II: IIP23167 De - 331 - wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings 5 R21, R22H, straight chain, 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-in such a manner that O- and / or S-atoms are not directly connected with each other, and wherein one or more H 15 atoms are each optionally replaced by F, Cl, CN or CF3, R0, R00H or alkyl having 1 to 12 C atoms, A1, A2a group selected from the following formulae 20253035P23167 De - 332 - 5Z1and Z2-CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO- O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O- or a single 10 bond, L1, L2, L3, L4F, Cl, OCF3, CF3, CH3, CH2F or CHF2, Y H, F, Cl, CF3, CHF2or CH3, 15 LCCH3or OCH3, a1 0, 1 or 2, 20 a2 0 or 1.

10. The LC display according to any one of Claims 1 to 9, characterized in that the LC medium further comprises one or more compounds selected from the group consisting of compounds of the formulae IIA, IIB, IIC, IID 25 and IIE:P23167 De - 333 -5 1015in which the individual radicals, on each occurrence identically or differ- ently, and each, independently of one another, have the following meaning: 20 R21, R22H, an alkyl, alkoxy or alkenyl radical having up to 15 C atoms which is unsubstituted or monosubstituted by F, Cl, CN or CF3 and where, in addition, one or more CH2 groups in these radicals may be replaced by -O-, -S-,-C ^C-, -CF2O-, -OCF2-,in such a way that O- and / or S-atoms are not linked directly to one another, 30 L1to L4F, Cl, CF3or CHF2, H, F, Cl, CF3, CHF2or CH3, 35 Z1, Z2a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O,P23167 De - 334 - p 0, 1 or 2, and q 0 or 1. 5 11. The LC display according to one or more of Claims 1 to 10, characterized in that the LC medium comprises one or more compounds of formula III: 10 III15 wherein the individual radicals, independently of each other and on each occurrence identically or differently, have the following meanings R31, R32H, an alkyl, alkoxy or alkenyl radical having up to 15 C atoms which is unsubstituted or monosubstituted by F, Cl, CN or 20 CF3and where, in addition, one or more CH2groups in these radicals may be replaced by -O-, -S-,-C ^C-, -CF2O-, -OCF2-,25 in such a way that O- and / or S-atoms are not linked directly to one another, A3a) a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups may be 30 replaced by -O- or -S-, b) a 1,4-phenylene radical, in which one or two CH groups may be replaced by N, or 35 c) a radical selected from the group consisting of spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octylene,P23167 De - 335 - 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, 5 wherein the radicals a), b) and c) may be mono- or polysubstituted by halogen atoms, n 0, 1 or 2,a single bond, 15 L11, L12F, Cl, CF3or CHF2, W O or S, Y1, Y2H, F, Cl, CF3, CHF2, CH3or OCH3. 20 12. The LC display according to to one or more of Claims 1 to 11, characterized in that the LC medium comprises one or more compounds of formula IV: 25in which 30 R41denotes an unsubstituted alkyl radical having 1 to 7 C atoms where, in addition, one or more CH2 may be replaced by, or an unsubstituted alkenyl radical having 2 to 7 C atoms, and 35P23167 De - 336 - R42denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms,.

13. The LC display according to one or more of Claims 1 to 12, 5 characterized in that the LC medium comprises one or more compounds of formula V: 10in which R51, R52independently of one another denote H, an alkyl, alkoxy or 15 alkenyl radical having up to 15 C atoms which is un- substituted, monosubstituted by F, Cl, CN or CF3or at least monosubstituted by halogen, where, in addition, one or more CH2groups in these radicals may be replaced by -O-, -S-,- C ^C-, -CF2O-, -OCF2-, -OC-O-, -O-CO- 20in such a way that O atoms are not linked directly to one another, 25, identically or differently, denote, 3035 Z51, Z52each, independently of one another, denote -CH2-CH2- , -CH2-O-,-CH=CH-, -C≡C-, -COO- or a single bond, andP23167 De - 337 - n is 1 or 2.

14. The LC display according to one or more of Claims 1 to 13, characterized 5 in that the LC medium additionally comprises one or more additives selected from the group consisting of chiral dopants, stabilisers, polymerization initiators and self alignment additives.

15. The LC display according to one or more of Claims 1 to 14, which is a 10 PS-VA, PS-IPS, PS-FFS or SA-VA display.

16. The LC display according to one or more of Claims 1 to 15, characterized in that it comprises two substrates, at least one of which is transparent to light, an electrode provided on each substrate or two electrodes provided 15 on only one of the substrates, and located between the substrates a layer of an LC medium as defined in one or more of Claims 1 to 14, wherein the polymerizable compounds are polymerized between the substrates of the display by UV photopolymerization. 20 17. A process for the production of an LC display according to one or more of Claims 1 to 16, comprising the steps of providing an LC medium as defined in one or more of Claims 1 to 14 between the substrates of the display, and polymerizing the polymerizable compounds by irradiation with UV light, 25 18. The process of Claim 17, wherein a voltage is applied to the electrodes of the display during polymerization of the polymerizable compounds.

19. An LC medium as defined in one or more of Claims 1 to 14. 30 20. A process of preparing an LC medium according to Claim 19, comprising the steps of mixing or more RMs as defined in one or more of Claims 1 to 8 with one or more compounds of formula II, III, IV and / or V as defined in one or more of Claims 9 to 13, and optionally with further liquid- 35 crystalline compounds and / or additives, and optionally polymerizing the polymerizable compounds.

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