Liquid crystal media comprising polymerizable compounds and their use in liquid crystal displays

Abstract

The present invention relates to liquid crystal (LC) media comprising one or more polymerizable compounds and to the use of said LC media for optical, electrooptical and electronic purposes, in particular in LC displays, in particular in LC displays of the polymer stabilized alignment (PS, PSA) or self-aligned (SA) type.

Description

[0001] The present invention relates to liquid-crystalline (LC) media comprising one or more polymerizable compounds and to the use of such liquid-crystalline media for optical, electrooptical and electronic purposes, in particular in LC displays, in particular in LC displays of the polymer-stabilized alignment (PS, PSA) or self-aligned (SA) type. Background of the Invention

[0003] One liquid crystal display (LCD) mode currently in use is the TN ("twisted nematic") mode. However, a disadvantage of TN LCDs is that the contrast has a strong dependence on the viewing angle.

[0004] In addition, so-called VA (vertically aligned) displays with wider viewing angles are known. The LC cell of a VA display contains a layer of an LC medium between two transparent electrodes, wherein the LC medium generally has a negative dielectric anisotropy. In the off state, the molecules of the LC layer are aligned perpendicularly to the electrode surfaces (homeotropically) or have a tilted homeotropic alignment. When a voltage is applied to the two electrodes, a realignment of the LC molecules parallel to the electrode surfaces occurs.

[0005] In addition, OCB ("Optically Compensated Bend") displays are known which are based on the birefringence effect and have an LC layer with a so-called "bend" alignment and a generally positive dielectric anisotropy. When a voltage is applied, a realignment of the LC molecules perpendicular to the electrode surfaces occurs. In addition, OCB displays usually contain one or more birefringent optical retardation films to prevent undesired light transmittance of the bend cell in the dark state. OCB displays have wider viewing angles and shorter response times relative to TN displays.

[0006] Also known are so-called IPS ("in-plane switching") displays, which comprise an LC layer between two substrates, wherein two electrodes are arranged on only one of the two substrates and preferably have a mutually meshing comb-like structure. When a voltage is applied to the electrodes, an electric field with a significant component parallel to the LC layer is thus generated between them. This leads to a realignment of the LC molecules in the plane of the layer.

[0007] In addition, so-called FFS (fringe field switching) displays have been reported (see in particular SH Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, 1028), which comprise two electrodes on the same substrate, one of which is structured in a comb-like manner and the other is unstructured. This results in a strong so-called "fringe field", i.e. a strong electric field close to the electrode edges, and an electric field with a strong vertical component and a strong horizontal component throughout the liquid crystal cell. FFS displays have a small viewing angle dependence of the contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy and an alignment layer, usually an alignment layer of polyimide, which provides a planar alignment of the molecules of the LC medium.

[0008] FFS displays can be operated as active matrix or passive matrix displays. In the case of active matrix displays, the individual pixels are typically addressed by integrated non-linear active elements such as transistors (e.g., thin film transistors or "TFTs"), while in the case of passive matrix displays, the individual pixels are typically addressed according to multiplexing methods as known in the art.

[0009] In addition, FFS displays have been disclosed (see SH Lee et al., Appl. Phys. Lett. 73 (20), 1998, 2882-2883 and SH Lee et al., Liquid Crystals 39 (9), 2012, 1141-1148) which have an electrode design and layer thickness similar to those of FFS displays, but include a layer of an LC medium having a negative dielectric anisotropy instead of a layer of an LC medium having a positive dielectric anisotropy. LC media having a negative dielectric anisotropy show a more favorable director orientation, with a less tilted and more twisted orientation, than LC media having a positive dielectric anisotropy, with the result that these displays have a higher transmittance. The display further includes an alignment layer, preferably a polyimide provided on at least one substrate, which contacts the LC medium and induces a planar alignment of the LC molecules of the LC medium. These displays are also referred to as "ultra-brightness FFS (UB-FFS)" mode displays. These displays require an LC medium having high reliability.

[0010] The term "reliability" as used hereinafter means the quality of the performance of a display over time and under different stress loads, such as light load, temperature, humidity, voltage, and includes display effects such as image sticking (area and line image sticking), color differences (mura), yogore, etc., which are known to the person skilled in the art in the field of LC displays. As a standard parameter for classifying reliability, the voltage holding ratio (VHR) value is usually used, which is a measure for maintaining a constant voltage in a test display. Among other factors, a high VHR is a prerequisite for a high reliability of LC media.

[0011] In the newer types of VA displays, the uniform alignment of the LC molecules is limited to a number of relatively small domains within the LC cell. There can be disclinations between these domains, also called tilted domains. VA displays with tilted domains have greater contrast and viewing angle independence of grey shades relative to conventional VA displays. In addition, this type of display is easier to produce, since additional surface treatment of the electrodes (e.g. by rubbing) is no longer necessary for uniformly aligning the molecules in the switched-on state. Instead, the preferential orientation of the tilt angle or pretilt angle is controlled by a special design of the electrodes.

[0012] In so-called MVA (multi-domain vertical alignment) displays, this is usually achieved by electrodes having protrusions that cause local pre-tilt. As a result, when a voltage is applied, the LC molecules are aligned parallel to the electrode surface in different directions in different, defined cell areas. This achieves "controlled" switching and prevents the formation of interfering disclination lines. Although this arrangement improves the viewing angle of the display, it leads to a reduction in its light transmittance. A further improvement of the MVA uses protrusions only on one electrode side, while the opposite electrode has a slit, which improves the light transmittance. The slit electrode generates an inhomogeneous electric field in the LC cell when a voltage is applied, which means that controlled switching is still achieved. To further improve the light transmittance, the spacing between the slit and the protrusion can be enlarged, but this in turn leads to a longer response time. In so-called PVA ("patterned VA"), the protrusions become completely superfluous, since the two electrodes are structured on opposite sides by slits, which leads to increased contrast and improved light transmission, but this is technically difficult and makes the display more sensitive to mechanical influences ("tapping" etc.). However, for many applications, such as monitors and especially TV screens, it is required to shorten the response time of the display and to improve the contrast and brightness (transmittance) of the display.

[0013] Another development is the so-called PS ("polymer stabilized") or PSA ("polymer stabilized alignment") displays, for which the term "polymer stabilized" is occasionally also used. In these, small amounts (e.g. 0.3% by weight, typically <1% by weight) of one or more polymerizable compounds, preferably polymerizable monomeric compounds, are added to the LC medium and, after the LC medium has been filled into the display, are polymerized or crosslinked in situ (generally by UV photopolymerization), while optionally applying a voltage to the electrodes of the display. The polymerization takes place at a temperature at which the LC medium exhibits a liquid-crystalline phase, generally at room temperature. The addition of polymerizable mesogens or liquid-crystalline compounds (also called reactive mesogens or "RMs") to the LC mixture has proven to be particularly suitable.

[0014] Unless otherwise stated, the term "PSA" is used hereinafter when referring generally to displays of the polymer stabilized alignment type, and "PS" is used when referring to specific display modes (such as PS-VA, PS-TN, etc.).

[0015] Furthermore, unless otherwise stated, the term "RM" is used hereinafter when referring to polymerisable mesogenic or liquid crystal compounds.

[0016] At the same time, the PS(A) principle is being used in various conventional LC display modes. Thus, for example, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS and PS-TN displays are known. The polymerization of the RMs preferably takes place under an applied voltage in the case of PS-VA and PS-OCB displays, with or without, preferably without, an applied voltage in the case of PS-IPS displays. As can be verified in a test cell, the PS(A) method leads to a pretilt in the cell. In the case of a PS-OCB display, for example, the curved structure can be stabilized so that the offset voltage is not required or can be reduced. In the case of a PS-VA display, this pretilt has a positive effect on the response time. For PS-VA displays, standard MVA or PVA pixel and electrode layouts can be used. However, in addition, for example, only one structured electrode side without protrusions can also be managed, which significantly simplifies production and at the same time produces very good contrast and very good light transmittance.

[0017] Furthermore, so-called positive VA displays ("positive VA") have proven to be a particularly advantageous mode. Similar to conventional VA displays, in positive VA displays the initial orientation of the LC molecules in the initial state when no voltage is applied is homeotropic, i.e. substantially perpendicular to the substrate. However, in contrast to conventional VA displays, an LC medium with positive dielectric anisotropy is used in positive VA displays. Similar to the commonly used IPS displays, the two electrodes in a positive VA display are arranged on only one of the two substrates and preferably exhibit a mutually meshing and comb-like (cross-finger-shaped) structure. By applying a voltage to the cross-finger-shaped electrodes, which generates an electric field substantially parallel to the LC medium layer, the LC molecules are converted into an orientation substantially parallel to the substrate. In positive VA displays, polymer stabilization (by adding RMs (which are polymerized in the display) to the liquid crystal medium) has also proven to be advantageous, whereby a significant reduction in the response time can be achieved.

[0018] PS-VA displays are described, for example, in EP 1 170 626 A2, US 6,861,107, US 7,169,449, US 2004 / 0191428 A1, US 2006 / 0066793 A1 and US 2006 / 0103804 A1. PS-OCB displays are described, for example, in T.-J-Chen et al., Jpn. J. Appl. Phys. 45, 2006, 2702-2704 and SH Kim, L.-C-Chien, Jpn. J. Appl. Phys. 43, 2004, 7643-7647. PS-IPS displays are described, for example, in US 6,177,972 and Appl. Phys. Lett. 1999, 75 (21), 3264. PS-TN displays are described, for example, in Optics Express 2004, 12(7), 1221.

[0019] Below the layer formed of phase-separated and polymerized RMs inducing the above-mentioned pretilt angle, PSA displays typically comprise an alignment layer, for example of polyimide, which provides an initial alignment of the LC molecules prior to the polymer stabilization step.

[0020] Rubbed polyimide layers have long been used as alignment layers. However, the rubbing process causes a variety of problems, such as color differences, contamination, electrostatic discharge problems, residues, etc. Usually, the effort and cost of producing such polyimide layers are relatively large. Therefore, instead of rubbing the polyimide layer, it is proposed to use a method of orderly preparing a polyimide layer by photoalignment, using the light-induced orientation of the alignment surface. This can be achieved by photolysis, photodimerization or photoisomerization with the help of polarized light.

[0021] In addition, it has been observed that unfavorable interactions of the polyimide alignment layer with certain compounds of the LC medium generally lead to a reduction in the resistance of the display. The number of suitable and usable LC compounds is thus significantly reduced, at the expense of the display parameters (such as viewing angle dependence, contrast and response time) that are intended to be improved by using such LC compounds. It is therefore desirable to omit the polyimide alignment layer.

[0022] For some display modes, this is achieved by adding self-aligning agents or additives to the LC medium, which induce the desired alignment, such as homeotropic or planar alignment, in situ by a self-assembly mechanism. Thus, the alignment layer on one or both of the substrates can be omitted. These display modes are also called "self-aligning", "self-aligning" or "self-aligning" (SA) modes.

[0023] In SA displays, small amounts (typically 0.1% to 2.5%) of self-aligning additives are added to the LC medium. Suitable self-aligning additives are, for example, compounds having an organic core group and one or more polar anchoring groups attached thereto, which can interact with the substrate surface so that the additive on the substrate surface is aligned and also induces the desired alignment in the LC molecules. Preferred self-aligning additives comprise, for example, mesogenic groups and linear or branched alkyl side chains terminated with one or more polar anchoring groups, which are, for example, selected from hydroxyl, carboxyl, amino or thiol groups. The self-aligning additive may also contain one or more polymerizable groups that can be polymerized under similar conditions to the RMs used for the PSA process.

[0024] SA-VA displays have been disclosed so far. Suitable self-aligning additives for inducing homeotropic alignment, in particular for use in VA mode displays, are disclosed in, for example, US 2013 / 0182202 A1, US 2014 / 0138581 A1, US 2015 / 0166890 A1 and US 2015 / 0252265 A1.

[0025] The SA mode can also be used in combination with the PSA mode. LC media for displays in this combined mode therefore contain one or more RMs and one or more self-aligning additives.

[0026] Hereinafter, a display combining both SA and PSA modes is also referred to as a "PS-SA" display. In addition, unless otherwise specified, the term "PSA mode" or "PSA display" used hereinafter should be understood to include SA and PS-SA modes and displays.

[0027] LC displays, including those of the PSA and SA modes, can be operated as active matrix or passive matrix displays. In the case of active matrix displays, the individual pixels are typically addressed by integrated non-linear active elements such as transistors (e.g. thin film transistors "TFTs"), while in the case of passive matrix displays, they are typically addressed by multiplexing methods as known in the art.

[0028] If the display is not one of the SA modes, it may also comprise an alignment layer on one or both substrates forming the display cell. The alignment layer is usually applied to the electrodes (where such electrodes are present) so that it is in contact with the LC medium and induces an initial alignment of the LC molecules. The alignment layer also comprises or consists of, for example, polyimide, which may also be rubbed, or may be prepared by a photoalignment method.

[0029] Particularly for monitors and especially TV applications, there is a continuing demand for optimization of the response time of liquid crystal displays as well as of the contrast and brightness (and therefore also the transmittance). The PSA method can offer key advantages here. In particular in the case of PS-VA, PS-IPS or PS-FFS displays, a reduction in the response time associated with the pretilt measurable in the test cell can be achieved without significant detrimental effects on other parameters.

[0030] The prior art has already proposed the use of optionally fluorinated biphenyl diacrylate or dimethacrylate as RM in PSA displays.

[0031] However, the problem arises that not all combinations of LC mixtures and one or more RMs are suitable for PSA displays, because, for example, insufficient tilt or no tilt at all is established, or because, for example, the VHR is insufficient for TFT display applications. Furthermore, it has been found that the LC mixtures and RMs known from the prior art still have some disadvantages when used in PSA displays. Therefore, not every known RM that is soluble in an LC mixture is suitable for PSA displays. Furthermore, apart from the direct measurement of the pretilt in PSA displays, it is often difficult to find suitable selection criteria for the RMs. If it is desired to carry out the polymerization with the aid of UV light without the addition of photoinitiators, which may be advantageous for certain applications, the choice of suitable RMs becomes even smaller.

[0032] In addition, the selected LC host mixture / RM combination should have the lowest possible rotational viscosity and the best possible electrical properties. In particular, it should have the highest possible VHR. In PSA displays, a high VHR after irradiation with UV light is particularly desirable, since UV exposure is an essential part of the display production process and also occurs as normal exposure during operation of the manufactured display.

[0033] In particular, it is desirable to make available novel materials for PSA displays which produce particularly small tilt angles. Preferred materials are those which, during polymerization, produce lower tilt angles for the same exposure time than previously known materials and / or by using them (higher) tilt angles which were already achievable with known materials can be achieved even after shorter exposure times. As a result, the production time ("takt time") of the displays can be shortened and the costs of the production process can be reduced.

[0034] Another problem in producing PSA displays is the presence or removal of residual amounts of unpolymerized RMs, particularly after the polymerization step used to create the tilt angle in the display. For example, such unreacted RMs may adversely affect the properties of the display by polymerizing in an uncontrolled manner, for example, after the display is made, during operation.

[0035] Therefore, PSA displays known from the prior art often show the undesirable effect of so-called "image sticking" or "image burning", i.e. the image produced by brief addressing of individual pixels in an LC display remains visible even after the electric field in these pixels has been switched off or after other pixels have been addressed.

[0036] This "image sticking" can occur on the one hand if LC host mixtures with a low VHR are used. The UV components of sunlight or backlighting can trigger undesirable decomposition reactions of the LC molecules and thus the production of ionic or free-radical impurities. These can accumulate, in particular at the electrodes or alignment layers, where they can reduce the effectively applied voltage. This effect can also be observed in conventional LC displays without polymer components.

[0037] In addition, additional "image sticking" effects due to the presence of unpolymerized RMs are often observed in PSA displays. Uncontrolled polymerization of residual RMs is initiated here by UV light from the environment or from the backlight. In the switched display area, this changes the tilt angle after a number of addressing cycles. As a result, a change in the transmittance can occur in the switched area, while it remains unchanged in the unswitched area.

[0038] It is therefore desirable that the polymerization of RMs during the production of PSA displays proceeds as completely as possible and that the presence of unpolymerized RMs in the display is excluded as much as possible or reduced to a minimum. Therefore, RM and LC mixtures are needed which enable or support highly efficient and complete polymerization of RMs. Furthermore, a controlled reaction of the residual RM amount is desirable. This would be simpler if the RMs could polymerize faster and more efficiently than the hitherto known materials.

[0039] Another problem observed in the operation of PSA displays is the stability of the tilt angle. Thus, it is observed that the tilt angle (which is generated during the manufacturing process of the display by polymerizing the RM as described above) does not remain constant, but deteriorates after the display is subjected to voltage stress during its operation. This can have a negative impact on the display performance, for example by increasing the black state transmittance and thus reducing the contrast.

[0040] Another problem to be solved is that the RMs of the prior art do often have high melting points and do show only limited solubility in many currently common LC mixtures and therefore often tend to crystallize out spontaneously from the mixture. Furthermore, the risk of spontaneous polymerization prevents the LC host mixture from being warmed in order to dissolve the polymerizable components, which means that the best possible solubility even at room temperature is necessary. Furthermore, there is a risk of separation, for example when the LC medium is introduced into an LC display (chromatographic effect), which can greatly impair the homogeneity of the display. This is further increased by the fact that the LC medium is usually introduced at low temperature to reduce the risk of spontaneous polymerization (see above), which in turn has an adverse effect on the solubility.

[0041] Another problem observed in the prior art is that PSA-SA displays that do not include a polyimide (PI) alignment layer (hereinafter also referred to as "PI-free" displays) may show an undesirable reflectivity depending on the layer stack. This is because the PI layer is replaced by a polymerized RM layer, which is formed in a subsequent polymerization step after assembling the display box and has a thickness and refractive index that is generally lower than that of the PI layer. This may cause undesirable reflectivity at the interface with the substrate because the polymerized RM layer may no longer satisfy the refractive index matching between the previously used PI layer and the substrate. As a result, a degradation in contrast can be observed. This is a serious disadvantage, especially for displays in high-end applications that require high contrast even in daylight.

[0042] Another problem observed in the prior art is that the use of conventional LC media in LC displays (including but not limited to SA and PSA type displays) often results in color aberrations in the display, especially when the LC media is filled in a display cell manufactured using an over-drop fill (ODF) method. This phenomenon is also referred to as "ODF color aberration". It is therefore desirable to provide LC media that result in reduced ODF color aberrations.

[0043] Another problem observed in the prior art is that LC media used in LC displays, including but not limited to PSA type displays, often exhibit high viscosities and, therefore, high switching times. In order to reduce the viscosity and switching times of the LC media, it has been proposed in the prior art to add LC compounds having alkenyl groups. However, it has been observed that LC media containing alkenyl compounds often show reduced reliability and stability, as well as a reduction in the VHR, especially after exposure to UV radiation. Especially for use in PSA displays, this is a considerable disadvantage, since in PSA displays the photopolymerization of the RMs is usually carried out by exposure to UV radiation, which can lead to a reduction in the VHR in the LC media.

[0044] There therefore still remains a great need for LC displays, in particular those of the SA and PSA mode, and for LC media and polymerizable compounds for use in such displays which do not exhibit the disadvantages mentioned above or exhibit these disadvantages only to a small extent and have improved properties.

[0045] In particular, there is a great need for SA and / or PSA displays and LC media and polymerizable compounds for such displays which enable high specific resistances over a large operating temperature range, short response times even at low temperatures and low threshold voltages, low tilt angles, a large number of grayscales, high contrast and wide viewing angles, good reflectivity and high contrast in daylight. In addition, the compounds and LC media should show high reliability and high values ​​of (VHR) after UV exposure and, in the case of polymerizable compounds, low melting points and high solubility in LC host mixtures. In displays for mobile applications, it is particularly desirable to have available LC media which exhibit low threshold voltages and high birefringence.

[0046] In the prior art, several types of RMs have been reported for use in SA and PSA displays, such as RMs having a biphenyl or terphenyl mesogenic core and two or three polymerizable acrylate or methacrylate groups attached thereto. Biphenyl RMs have been shown to exhibit limited polymerization speed but good reliability parameters, such as high VHR or tilt stability, while terphenyl RMs have been shown to exhibit fast polymerization speed but limited reliability parameters. It is therefore desirable to have available RMs that exhibit both fast polymerization speed and good reliability parameters.

[0047] It is an object of the present invention to provide new suitable materials, in particular RMs for LC displays, especially for SA and PSA displays, and LC media comprising the same, which do not have the disadvantages indicated above or have the disadvantages indicated above to a lesser extent.

[0048] In particular, the object of the present invention is to provide RMs for SA and PSA displays and LC media comprising the same, which achieve very high specific resistance values, high VHR values, high reliability, low threshold voltage, short response time, high birefringence, high contrast, show good UV absorption in particular at longer wavelengths, enable rapid and complete polymerization of the RM, enable low tilt angles to be produced preferably as quickly as possible, achieve high stability of the tilt angle even after longer times and / or UV exposure, reduce or prevent the occurrence of "image sticking" and "ODF color differences" in displays, and in the case of RMs polymerize as quickly and completely as possible, and show high solubility in LC media typically used as host mixtures in PSA displays.

[0049] Another object of the present invention is to provide RMs for PSA displays which exhibit both a fast polymerization speed and good reliability parameters, like high VHR or tilt stability.

[0050] Another object of the present invention is to provide new RMs, in particular for use in optical, electro-optical and electronic applications; and suitable processes and intermediates for their preparation.

[0051] These objects have been achieved according to the invention by the materials and methods as described in the present application. In particular, it has been surprisingly found that the use of LC media as described hereinafter makes it possible to achieve the advantageous effects as mentioned above. These LC media compounds comprise an RM having an aromatic mesogenic core substituted by at least one alkenyl group and further comprising one or more polymerizable reactive groups.

[0052] It has been surprisingly found that the use of these LC media in PSA displays, in particular at longer UV wavelengths in the range of 300-380 nm and especially greater than 320 nm, even without added photoinitiators, promotes fast and complete UV photopolymerization; leads to the rapid generation of low and stable tilt angles; reduces image sticking and ODF color differences in the display; leads to high reliability and high VHR values ​​after UV photopolymerization, in particular in the case of LC host mixtures containing LC compounds with alkenyl groups; and enables fast response times, low threshold voltages and high birefringence to be achieved.

[0053] It has also been surprisingly found that the use of an LC medium as disclosed and claimed hereinafter in a SA-PSA display leads to a higher refractive index of the polymerized layer and thus helps to avoid problems with undesired reflectivity variations and low contrast in the display.

[0054] In addition, the RM used in the LC media of the present invention has a low melting point, good solubility in a wide range of LC media, especially in commercially available LC host mixtures for PSA applications, and a low tendency to crystallize. In addition, it exhibits good absorption at longer UV wavelengths, in particular in the range of 300-380 nm, and enables rapid and complete polymerization, with little residual, unreacted RM in the cell.

[0055] US 8355110 B2 discloses a liquid crystal display comprising a liquid crystal compound and at least two reactive mesogens, one of which comprises a phenyl group substituted by a vinyl group, and further discloses the compound 2-vinyl-biphenyl-4,4'-dimethacrylate, but does not disclose or suggest the LC medium disclosed and claimed below. SUMMARY OF THE INVENTION

[0057] The present invention relates to an LC medium comprising:

[0058] a polymerizable component A) comprising, preferably consisting of, one or more polymerizable compounds, at least one of which is a compound of formula I,

[0059] a liquid crystal component B), hereinafter also referred to as "LC host mixture", which comprises, preferably consists of, one or more mesogenic or liquid crystal compounds, and

[0060] - optionally one or more additives selected from self-aligning additives of formula II and stabilizers,

[0061] P-Sp-A 1 -(Z 1 -A 2 ) z -R b I

[0062] MES-R a II

[0063] where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings:

[0064] R b Indicates P-Sp or R,

[0065] R represents F, Cl, -CN or a straight-chain, branched or cyclic alkyl radical having 1 to 25 C atoms, wherein one or more non-adjacent CH 2- group is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O atoms and / or the S atoms are not directly connected to each other, and wherein one or more H atoms are each optionally replaced by F or Cl,

[0066] P represents a polymerizable group,

[0067] Sp represents a spacer group or a single bond optionally substituted by P,

[0068] A 1 , A 2 represents a monocyclic or polycyclic aromatic or heteroaromatic group having 4 to 20 ring atoms, which is optionally substituted by one or more groups L, A or P-Sp-,

[0069] Wherein the compound of formula I comprises at least one group A substituted by at least one group A 1 or A 2 ,

[0070] Z 1 Represents -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH 2 -、-CH 2 O-、-SCH 2 -、-CH 2 S-、-CF 2 O-、-OCF 2 -、-CF 2 S-, -SCF 2 -、-(CH 2 ) n1 -、-CF 2 CH 2 -、-CH 2 CF 2 -、-(CF 2 ) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH 2 -CH 2 -CO-O-, -O-CO-CH 2 -CH 2 -、-CR 0 R 00 - or single key,

[0071] R 0 , R 00 represents H or an alkyl group having 1 to 12 C atoms,

[0072] A represents an alkenyl group having 2 to 7, preferably 3 to 7, C atoms, preferably -CH=CH 2 、-CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 ,

[0073] L represents F, Cl, -CN, P-Sp- or a linear, branched or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 - group is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and wherein one or more H atoms are optionally replaced by P-Sp-, F or Cl,

[0074] z represents 0, 1, 2 or 3,

[0075] n1 means 1, 2, 3 or 4,

[0076] MES denotes a rod-shaped mesogenic group comprising two or more rings which are directly or indirectly connected to one another or fused to one another, wherein the rings are optionally substituted, and wherein the mesogenic group is optionally additionally substituted by one or more polymerizable groups which are directly connected to the MES or via a spacer, and

[0077] R a denotes a polar anchoring group which is located in the terminal position of the rod-shaped mesogenic group MES, which comprises at least one carbon atom and at least one group selected from -OH, -SH, -COOH, -CHO or a primary or secondary amine functional group, preferably one or two OH groups, and which optionally comprises one or two polymerizable groups P.

[0078] The liquid-crystalline component B) of the LC media according to the invention is also referred to hereinafter as "LC host mixture" and preferably comprises one or more, preferably at least two, mesogenic or LC compounds selected from non-polymerizable, low molecular weight compounds.

[0079] The present invention furthermore relates to an LC medium as described above and below, wherein the LC host mixture or component B) comprises at least one mesogen or LC compound comprising alkenyl groups.

[0080] The invention furthermore relates to an LC medium or an LC display as described above, in which the compound of the formula I or the polymerisable compound of component A) is polymerised.

[0081] The present invention furthermore relates to a process for preparing an LC medium as described above and below, comprising the step of mixing one or more mesogens or LC compounds, or an LC host mixture or LC component B), as described above and below, with one or more compounds of formula I and optionally with further LC compounds and / or additives, such as those of formula II.

[0082] The invention furthermore relates to the use of the LC media according to the invention in SA or PSA displays.

[0083] The invention furthermore relates to LC displays, in particular PSA displays, particularly preferably PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-positive-VA or PS-TN displays, comprising one or more compounds of the formula I or an LC medium according to the invention.

[0084] The invention furthermore relates to the use of compounds of the formula I and LC media according to the invention in polymer-stabilized SA-VA and SA-FFS displays and to polymer-stabilized SA-VA or SA-FFS displays comprising one or more compounds of the formula I or LC media according to the invention.

[0085] The invention furthermore relates to LC displays comprising a polymer obtainable by polymerization of one or more compounds of the formula I or of a polymerizable component A) as described above, or comprising an LC medium according to the invention, preferably a PSA display, very preferably a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-positive-VA, PS-TN or a polymer-stabilized SA-VA or SA-FFS display.

[0086] The invention furthermore relates to an LC display of the PSA type comprising two substrates, at least one of which is transparent to light, electrodes provided on each substrate or two electrodes provided on only one of the substrates and a layer of an LC medium located between the substrates, the layer of LC medium comprising one or more polymerizable compounds and LC components as described above and below, wherein the polymerizable compound between the substrates of the display is polymerized.

[0087] The invention furthermore relates to a method of manufacturing an LC display as described above and below, comprising the steps of filling or otherwise providing an LC medium between substrates of the display, the LC medium comprising one or more polymerisable compounds as described above and below, and polymerising the polymerisable compounds.

[0088] The PSA display according to the invention has two electrodes, preferably in the form of transparent layers, which are applied to one or both of the substrates. In some displays, for example in PS-VA, PS-OCB, PS-TN or polymer-stabilized SA-VA displays, one electrode is applied to each of the two substrates. In other displays, for example in PS-positive-VA, PS-IPS, PS-FFS, PS-UB-FFS or polymer-stabilized SA-FFS displays, the two electrodes are applied to only one of the two substrates.

[0089] In a preferred embodiment, the polymerisable components are polymerised in the LC display while a voltage is applied to the electrodes of the display.

[0090] The polymerizable compounds of the polymerizable component are preferably polymerized by photopolymerization, very preferably by UV photopolymerization.

[0091] The alkenyl groups A in the compounds of formula I disclosed and claimed in the present application are not considered to be within the meaning of the term "polymerizable group" as used herein. Preferably, the LC media disclosed and claimed in the present application do not comprise additives which initiate or enhance the participation of the alkenyl groups A in polymerisation reactions. DETAILED DESCRIPTION OF THE INVENTION

[0093] When used in PSA and PS-SA displays, the LC media according to the invention exhibit the following advantageous properties:

[0094] - Low refractive index and low reflectivity,

[0095] - suitable tilt generation within a certain process window,

[0096] - fast polymerization resulting in minimal residues of RM after UV treatment,

[0097] -High voltage holding rate after UV treatment,

[0098] - Good tilt stability,

[0099] -Fully heat-resistant and stable,

[0100] - Sufficient solubility of the polymerizable compound in organic solvents typically used in display manufacturing.

[0101] In particular, the LC media according to the invention surprisingly indeed exhibit a higher refractive index and a lower reflectivity when used in PI-free PS-SA displays compared to the LC media known from the prior art.

[0102] It has also been surprisingly found that in compounds of formula I, pendant alkenyl substituents on the benzene or naphthalene rings do not appear to negatively affect properties such as polymerization rate and conversion, tilt generation or reliability.

[0103] Unless otherwise indicated, compounds of the formula I are preferably selected from achiral compounds.

[0104] As used herein, the terms "active layer" and "switchable layer" mean in an electro-optical display, for example in an LC display, a layer comprising one or more molecules with structural and optical anisotropy (for example LC molecules), which molecules change their orientation when subjected to an external stimulus such as an electric or magnetic field, which results in a change in the transmittance of the layer for polarized or unpolarized light.

[0105] As used herein, the terms "tilt" and "tilt angle" are to be understood as meaning the tilted alignment of the LC molecules of the LC medium relative to the cell surface in an LC display (preferably a PSA display here) and are to be understood as including "pretilt" and "pretilt angle". The tilt angle here denotes the average angle (<90°) between the longitudinal molecular axis of the LC molecules (LC director) and the plane-parallel outer plates forming the LC cell. Low absolute values ​​of the tilt angle here (i.e. large deviations from an angle of 90°) correspond to large tilts. A suitable method for measuring the tilt angle is given in the Examples. Unless otherwise stated, the tilt angle values ​​disclosed above and below relate to this measurement method.

[0106] As used herein, the terms "reactive mesogen" and "RM" are understood to mean a compound comprising a mesogenic or liquid crystal backbone and attached thereto one or more functional groups suitable for polymerization, also referred to as "polymerizable groups" or "P".

[0107] Unless otherwise indicated, the term "polymerizable compound" as used herein is to be understood as a polymerizable monomeric compound.

[0108] A SA-VA or SA-FFS display according to the present invention will have a polymer-stabilized mode due to the fact that it comprises or is manufactured by using an LC medium comprising an RM of formula I. Therefore, as used herein, when referring to a display according to the present invention, the terms "SA-VA display" and "SA-FFS display" are to be understood as referring to a polymer-stabilized SA-VA or SA-FFS display, even if not explicitly mentioned.

[0109] As used herein, the term "low molecular weight compound" is understood to mean a compound that is monomeric and / or not prepared by polymerization, as opposed to a "polymeric compound" or "polymer."

[0110] As used herein, the term "non-polymerizable compound" is understood to mean a compound that does not contain functional groups suitable for polymerization under the conditions normally applied to RM polymerization.

[0111] As used herein, the term "mesogenic group" is known to those skilled in the art and is described in the literature and refers to a group that substantially contributes to the generation of a liquid crystal (LC) phase in a low molecular weight or polymeric substance due to its anisotropy of attractive and repulsive interactions. A compound comprising a mesogenic group (mesogenic compound) does not necessarily have an LC phase per se. A mesogenic compound may also exhibit LC phase behavior only after mixing with other compounds and / or after polymerization. Typical mesogenic groups are, for example, rigid rod-shaped or disc-shaped units. Terms and definitions used in connection with mesogenic or LC compounds are given in Pure Appl. Chem. 2001, 73 (5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368.

[0112] As used herein, the term "spacer" (hereinafter also referred to as "Sp") is known to those skilled in the art in the art and is described in the literature, see for example Pure Appl. Chem. 2001, 73 (5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. As used herein, the term "spacer" or "spacer" refers to a flexible group, for example an alkylene group, which is connected to the mesogenic group or polymerizable group (s) in the polymerizable mesogenic compound.

[0113] In context,

[0114]

[0115] represents a trans-1,4-cyclohexylene ring, and

[0116]

[0117] It represents a 1,4-phenylene ring.

[0118] In the group In , the single bond shown between two ring atoms can be attached to any free position of the benzene ring.

[0119] "Organic group" in this context means a carbon or hydrocarbon group.

[0120] "Carbon group" means a mono- or polyvalent organic group containing at least one carbon atom, wherein the group contains no other atoms (e.g. -C≡C-) or optionally contains one or more other atoms, such as N, O, S, B, P, Si, Se, As, Te or Ge (e.g. carbonyl, etc.). The term "hydrocarbyl group" means a carbon group which additionally contains one or more H atoms and optionally one or more heteroatoms, such as N, O, S, B, P, Si, Se, As, Te or Ge.

[0121] "Halogen" means F, Cl, Br or I, preferably F or Cl.

[0122] -CO-, -C(=O)- and -C(O)- represent carbonyl groups, i.e.

[0123] The carbon or hydrocarbon group can be a saturated or unsaturated group. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Carbon or hydrocarbon groups with more than 3 C atoms can be straight chain, branched and / or cyclic and can also contain spiro connections or condensed rings.

[0124] The terms "alkyl", "aryl", "heteroaryl" and the like also include polyvalent groups such as alkylene, arylene, heteroarylene and the like.

[0125] The term "aryl" refers to an aromatic carbon group or a group derived therefrom. The term "heteroaryl" refers to an "aryl" as defined above containing one or more heteroatoms (preferably selected from N, O, S, Se, Te, Si and Ge).

[0126] Preferred carbon and hydrocarbon radicals are optionally substituted, linear, branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy radicals having 1 to 40, preferably 1 to 20, very preferably 1 to 12 C atoms, optionally substituted aryl or aryloxy radicals having 5 to 30, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, aralkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy radicals having 5 to 30, preferably 6 to 25 C atoms, where one or more C atoms may also be replaced by heteroatoms, preferably selected from N, O, S, Se, Te, Si and Ge.

[0127] Further preferred carbon and hydrocarbyl groups are C 1 -C 20 Alkyl, C 2 -C 20 Alkenyl, C 2 -C 20 Alkynyl, C 3 -C 20 Allyl, C 4 -C20 Alkyldiene, C 4 -C 20 Polyene, C 6 -C 20 Cycloalkyl, C 4 -C 15 Cycloalkenyl, C 6 -C 30 Aryl, C 6 -C 30 Alkyl aryl, C 6 -C 30 Aralkyl, C 6 -C 30 Alkyl aryloxy, C 6 -C 30 Arylalkoxy, C 2 -C 30 Heteroaryl, C 2 -C 30 Heteroaryloxy.

[0128] Particularly preferred is C 1 -C 12 Alkyl, C 2 -C 12 Alkenyl, C 2 -C 12 Alkynyl, C 6 -C 25 Aryl and C 2 -C 25 Heteroaryl.

[0129] Further preferred carbyl and hydrocarbyl groups are straight-chain, branched or cyclic alkyl groups having 1 to 20, preferably 1 to 12 C atoms, which are unsubstituted or mono- or polysubstituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH 2 The groups may each be independently replaced by -C(R x )=C(R x )-、-C≡C-、-N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other.

[0130] R xPreferably it represents H, F, Cl, CN, a straight-chain, branched or cyclic alkyl chain having 1 to 25 C atoms, wherein in addition one or more non-adjacent C atoms may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and wherein one or more H atoms may be replaced by F or Cl, or an optionally substituted aryl or aryloxy group having 6 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 30 C atoms.

[0131] Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, dodecyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, and the like.

[0132] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl and the like.

[0133] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl and the like.

[0134] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, 2-methylbutoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, and the like.

[0135] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

[0136] Aryl and heteroaryl groups may be monocyclic or polycyclic, i.e. they may contain one ring (e.g. phenyl) or two or more rings, which may also be fused (e.g. naphthyl) or covalently bonded (e.g. biphenyl), or a combination of fused and linked rings. Heteroaryl contains one or more heteroatoms, preferably selected from O, N, S and Se.

[0137] Particularly preferred are mono-, bi- or tricyclic aryl radicals having 6 to 25 C atoms and mono-, bi- or tricyclic heteroaryl radicals having 5 to 25 ring atoms, which optionally contain fused rings and are optionally substituted. Further preferred are 5-, 6- or 7-membered aryl and heteroaryl radicals, in which in addition one or more CH groups may be replaced by N, S or O in such a way that the O atoms and / or S atoms are not directly connected to one another.

[0138] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1':3',1"]-terphenyl-2'-yl, naphthyl, anthracenyl, binaphthyl, phenanthrenyl, 9,10-dihydro-phenanthrenyl, pyrene, dihydropyrene, Perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, and the like.

[0139] Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 6-membered rings such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine or fused groups such as indole, isoindole, indole, azine, indazole, benzimidazole, benzotriazole, purine, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazimidazole, quinoxalineimidazole, benzoxazole, naphthimidazole, anthraxazole, phenanthimidazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo- 7,8-quinoline, benzisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiophene, benzothiadiazolethiophene, or a combination of these groups.

[0140] The aryl and heteroaryl groups mentioned above and below may also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or other aryl or heteroaryl groups.

[0141] (Non-aromatic) alicyclic and heterocyclic groups include both saturated rings, i.e. rings containing only single bonds, and partially unsaturated rings, i.e. those which may also contain multiple bonds. The heterocyclic ring contains one or more heteroatoms, preferably selected from Si, O, N, S and Se.

[0142] (Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e. contain only one ring (e.g. cyclohexane), or polycyclic, i.e. contain multiple rings (e.g. decalin or bicyclooctane). Saturated groups are particularly preferred. In addition, mono-, bi- or tricyclic groups with 5 to 25 ring atoms are preferred, which optionally contain fused rings and are optionally substituted. Further preferred are 5-, 6-, 7- or 8-membered carbocyclic groups, in which, in addition, one or more C atoms may be replaced by Si and / or one or more CH groups may be replaced by N and / or one or more non-adjacent CH 2 The group may be substituted by -O- and / or -S-.

[0143] Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups, such as cyclopentane, tetrahydrofuran, tetrahydrothiophene, pyrrolidine; 6-membered groups, such as cyclohexane, silinane, cyclohexene, tetrahydropyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine; 7-membered groups, such as cycloheptane; and condensed groups, such as tetralin, decalin, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindan-2,5-diyl.

[0144] Preferred substituents are, for example, solubility promoting groups, such as alkyl or alkoxy groups; electron withdrawing groups, such as fluorine, nitro or nitrile; or substituents used to increase the glass transition temperature (Tg) of the polymer, especially bulky groups, such as tert-butyl or optionally substituted aryl groups.

[0145] Preferred substituents, hereinafter also referred to as "L S ", such as F, Cl, Br, I, -CN, -NO 2 , -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x ) 2 、-C(=O)Y 1 、-C(=O)R x 、-N(R x ) 2 , linear or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, in which one or more H atoms may be optionally replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, or optionally substituted aryl having 6 to 25, preferably 6 to 15 C atoms.

[0146] Where R xrepresents H, F, Cl, CN, or a linear, branched or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -group is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O- and / or S-atoms are not directly attached to one another, and wherein one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-, and

[0147] Y 1 Represents halogen.

[0148] "Substituted silyl or aryl" preferably means that it is replaced by halogen, -CN, R 0 、-OR 0 、-CO-R 0 、-CO-OR 0 、-O-CO-R 0 OR-O-CO-OR 0 Substitution, where R 0 represents H or an alkyl group having 1 to 20 C atoms.

[0149] Particularly preferred substituents L S For example, F, Cl, CN, NO 2 , CH 3 , C 2 H 5 、OCH 3 , OC 2 H 5 、COCH 3 、COC 2 H 5 、COOCH 3 、COOC 2 H 5 CF 3 、OCF 3 , OCHF 2 , OC 2 F 5 , in addition there is phenyl.

[0150] Preferably

[0151] wherein L has one of the meanings indicated above.

[0152] The polymerizable group P is a group suitable for polymerization reactions (e.g. free radical or ionic chain polymerization, addition polymerization or condensation polymerization), or a group suitable for polymer-analogous reactions (e.g. addition or condensation on the polymer backbone). Particularly preferred are groups for chain polymerization, in particular those containing a C=C double bond or a -C≡C- triple bond, and groups suitable for ring-opening polymerization, such as oxetane or epoxy groups.

[0153] Preferred groups P are selected from the group consisting of: CH 2 =CW 1 -CO-O-, CH 2 =CW 1 -CO-, CH 2 =CW 2 -(O) k3 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH 2 =CW 1 -CO-NH-, CH 3 -CH=CH-O-, (CH 2 =CH) 2 CH-OCO-, (CH 2 =CH-CH 2 ) 2 CH-OCO-, (CH 2 =CH) 2 CH-O-, (CH 2 =CH-CH 2 ) 2 N-, (CH 2 =CH-CH 2 ) 2 N-CO-、HO-CW 2 W 3 -、HS-CW 2 W 3 -、HW 2 N-、HO-CW 2 W 3 -NH-, CH 2 =CW 1 -CO-NH-, CH 2 =CH-(COO) k1 -Phe-(O) k2 -、CH 2 =CH-(CO) k1 -Phe-(O) k2-, Phe-CH=CH-, HOOC-, OCN- and W 4 W 5 W 6 Si-, where W 1 Indicates H, F, Cl, CN, CF 3 , phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH 3 , W 2 and W 3 each independently of one another represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each independently of one another represents H, Cl or an alkyl radical having 1 to 5 C atoms, Phe represents 1,4-phenylene, which is optionally substituted by one or more radicals L as defined above which are different from P-SP-, k 1 , k 2 and k 3 Each independently represents 0 or 1, k 3 Preferably, 1 is represented, and k 4 It represents an integer from 1 to 10.

[0154] Very preferred groups P are selected from the group consisting of: CH 2 =CW 1 -CO-O-, CH 2 =CW 1 -CO-, CH 2 =CW 2 -O-、CH 2 =CW 2 -、CW 1 =CH-CO-(O) k3 -、CW 1 =CH-CO-NH-, CH 2 =CW 1 -CO-NH-, (CH 2 =CH) 2 CH-OCO-, (CH 2 =CH-CH 2 ) 2 CH-OCO-, (CH 2 =CH) 2 CH-O-, (CH 2 =CH-CH 2 )2 N-, (CH 2 =CH-CH 2 ) 2 N-CO-、CH 2 =CW 1 -CO-NH-, CH 2 =CH-(COO) k1 -Phe-(O) k2 -、CH 2 =CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si-, where W 1 Indicates H, F, Cl, CN, CF 3 , phenyl or alkyl having 1 to 5 C atoms, in particular H, F, Cl or CH 3 , W 2 and W 3 each independently of one another represents H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each independently represents H, Cl or an alkyl group having 1 to 5 C atoms, Phe represents 1,4-phenylene, k 1 , k 2 and k 3 Each independently represents 0 or 1, k 3 Preferably, it means 1, and k 4 It represents an integer from 1 to 10.

[0155] Very preferably the group P is selected from the group consisting of: CH 2 =CW 1 -CO-O-, especially CH 2 =CH-CO-O-, CH 2 =C(CH 3 )-CO-O- and CH 2 =CF-CO-O-, and CH 2 =CH-O-, (CH 2 =CH) 2 CH-O-CO-, (CH 2 =CH) 2 CH-O-,

[0156] Other particularly preferred polymerizable groups P are selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy groups, most preferably from acrylate and methacrylate groups.

[0157] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X", so that each group P-Sp- corresponds to the formula P-Sp"-X"-, where

[0158] Sp" denotes a straight-chain or branched alkylene radical 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 CH 2 The groups are each independently -O-, -S-, -NH-, -N(R 0 )-、-Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00 )-CO-O-、-O-CO-N(R 0 )-、-N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C- in such a way that the O and / or S atoms are not directly connected to each other,

[0159] X" means -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-、-N(R 0 )-CO-、-N(R 0 )-CO-N(R 00 )-、-OCH 2 -、-CH 2 O-、-SCH 2 -、-CH 2 S-、-CF 2 O-、-OCF 2 -、-CF 2 S-, -SCF 2 -、-CF 2 CH 2 -、-CH 2 CF 2 -、-CF 2 CF 2 -, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -、-CY 2=CY 3 -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond,

[0160] R 0 and R 00 each independently of one another represents H or an alkyl group having 1 to 20 C atoms, and

[0161] Y 2 and Y 3 Each independently of one another represents H, F, Cl or CN.

[0162] X" is preferably -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -、-NR 0 -CO-、-NR 0 -CO-NR 00 - or single key.

[0163] Typical spacer groups Sp and -Sp"-X"- are, for example, -(CH 2 ) p1 -、-(CH 2 ) p1 -O-、-(CH 2 ) p1 -O-CO-, -(CH 2 ) p1 -CO-O-, -(CH 2 ) p1 -O-CO-O-, -(CH 2 CH 2 O) q1 -CH 2 CH 2 -、-CH 2 CH 2 -S-CH 2 CH 2 -、-CH 2 CH 2 -NH-CH 2 CH 2 -or-(SiR 0 R 00 -O) p1 -, wherein p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 has the meaning indicated above.

[0164] Particularly preferred groups Sp and -Sp"-X"- are -(CH 2 ) p1 -、-(CH2 ) p1 -O-、-(CH 2 ) p1 -O-CO-, -(CH 2 ) p1 -CO-O-, -(CH 2 ) p1 -O-CO-O-, wherein p1 and q1 have the meanings indicated above.

[0165] Particularly preferred radicals Sp" are in each case linear ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, methyleneoxybutylene, ethylenethioethylene, ethylene-N-methylimino-ethylene, 1-methylalkylene, vinylene, propenylene and butenylene.

[0166] In a preferred embodiment of the invention, the compounds of formula I and its subformulae contain a spacer group Sp substituted by one or more polymerizable groups P, such that the group Sp-P corresponds to Sp(P) s , s is ≥2 (branched polymerizable group).

[0167] Preferred compounds of formula I according to this preferred embodiment are those in which s is 2, i.e. containing the group Sp(P) 2 Very preferred compounds of formula I according to this preferred embodiment contain a group selected from the following formulae:

[0168] -X-alkyl-CHPP Sp1

[0169] -X-alkyl-CH((CH 2 ) aa P)((CH 2 ) bb P) Sp2

[0170] -XN((CH 2 ) aa P)((CH 2 ) bb P) Sp3

[0171] -X-alkyl-CHP-CH 2 -CH 2 P Sp4

[0172] -X-alkyl-C(CH 2 P)(CH 2 P)-C aa H 2aa+1 Sp5

[0173] -X-alkyl-CHP-CH 2 P Sp6

[0174] -X-alkyl-CPP-C aa H 2aa+1 Sp7

[0175] -X-alkyl-CHPCHP-C aa H 2aa+1 Sp8

[0176] Wherein P is as defined in Formula I,

[0177] Alkyl represents a single bond or a straight-chain or branched alkylene radical 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 CH 2 The groups may each independently of one another be linked to one another via -C(R 0 )=C(R 0 )-、-C≡C-、-N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- substitution, where R 0 have the meanings indicated above, aa and bb each independently represent 0, 1, 2, 3, 4, 5 or 6,

[0178] X has one of the meanings indicated for X", and is preferably O, CO, SO 2 , O-CO-, CO-O or a single bond.

[0179] Preferred spacer groups Sp(P) 2 Selected from the formulas Sp1, Sp2 and Sp3.

[0180] Very preferred spacer groups Sp(P) 2 Select from the following sub-formulas:

[0181] -CHPP Sp1a

[0182] -O-CHPP Sp1b

[0183] -CH 2 -CHPP Sp1c

[0184] -OCH 2 -CHPP Sp1d

[0185] -CH(CH 2 -P)(CH 2 -P) Sp2a

[0186] -OCH(CH 2 -P)(CH 2 -P) Sp2b

[0187] -CH 2 -CH(CH 2 -P)(CH 2 -P) Sp2c

[0188] -OCH 2 -CH(CH 2 -P)(CH 2 -P) Sp2d

[0189] -CO-NH((CH 2 ) 2 P)((CH 2 ) 2 P) Sp3a

[0190] In the compounds of formula I and subformulae thereof as described above and below, P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, most preferably from acrylate and methacrylate.

[0191] More preferred are compounds of the formula I and its subformulae as described above and below, wherein all polymerizable groups P present in the compounds have the same meaning and very preferably represent acrylate or methacrylate groups, most preferably methacrylate groups.

[0192] More preferred are compounds of formula I and its subformulae as described above and below, wherein R b It is P-Sp-.

[0193] More preferred are compounds of formula I and its subformulae as described above and below, wherein Sp represents a single bond or -(CH 2 ) p1 -、-O-(CH 2 ) p1 -、-O-CO-(CH 2 ) p1 or -CO-O-(CH 2 ) p1 , wherein p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH 2 ) p1 -、-O-CO-(CH 2 ) p1 or -CO-O-(CH 2 ) p1 , then the O-atom or CO-group, respectively, is attached to the benzene ring.

[0194] More preferred are compounds of the formula I and its subformulae as described above and below, wherein at least one group Sp is a single bond.

[0195] More preferred are compounds of the formula I and its subformulae as described above and below, wherein at least one group Sp is different from a single bond and is preferably selected from -(CH 2 ) p1 -、-O-(CH 2 ) p1 -、-O-CO-(CH 2 ) p1 or -CO-O-(CH 2 ) p1 , wherein p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH 2 ) p1 -、-O-CO-(CH 2 ) p1 or -CO-O-(CH 2 ) p1 , then the O-atom or CO-group, respectively, is attached to the benzene ring.

[0196] Preferably, A in Formula I 1 and A 2 represents benzene, naphthalene, phenanthrene, anthracene, dibenzofuran or dibenzothiophene, all of which are optionally substituted by one or more groups A, L or P-Sp-, and wherein at least one group A 1 or A 2 is substituted with at least one group A.

[0197] Preferably, -A in Formula I 1 -(Z 1 -A 2 ) z - denotes benzene, biphenylene, p-terphenylene (1,4-diphenylbenzene), m-terphenylene (1,3-diphenylbenzene), naphthylene, 2-phenyl-naphthylene, phenanthrene or anthracene, dibenzofuran or dibenzothiophene, all of which are optionally substituted by one or more radicals A, L or P-Sp- and are at least monosubstituted by A.

[0198] More preferred are compounds of formula I and subformulae thereof as described above and below, wherein -A 1 -(ZA 2 ) z -Selected from the following formula

[0199]

[0200]

[0201] wherein the benzene ring is optionally further substituted by one or more groups A, L or P-Sp- as defined in formula I, and at least one benzene ring is substituted by at least one group A.

[0202] Preferred compounds of formula I are selected from the following sub-formulas

[0203]

[0204]

[0205] where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings:

[0206] A, P, Sp, R b has one of the meanings given in formula I or one of the preferred meanings given above and below,

[0207] L 11 , L 12 , L 13 represents L or A, preferably F, Cl or A,

[0208] r1, r2, r3 represent 0, 1, 2, 3 or 4, preferably 0, 1 or 2, very preferably 0 or 1, wherein r1+r2+r3≥1,

[0209] r4, r5 represent 0, 1, 2 or 3, preferably 0, 1 or 2, very preferably 0 or 1, wherein, in formula I3, r4+r5≥1, and in formulas I4a and I4b, r1+r4+r5≥1,

[0210] The compound contains at least one group L which is A 11 , L 12 or L 13 .

[0211] Preferred are compounds of formula I and I1-I5, wherein R b It's P-Sp.

[0212] More preferred are compounds of formula I and I1-I5, wherein R b Different from P-Sp.

[0213] Very particular preference is given to compounds of the formulae I1, I2 and I5.

[0214] Preferred compounds of formula I and I1 to I5 are selected from the following sub-formulae:

[0215]

[0216]

[0217]

[0218]

[0219]

[0220] Among them, P, Sp, L 11-13 and r1-r5 have the meanings given in formula I or one of the preferred meanings given above and below, c is 1 or 2, Sp(P) 2 represents a spacer group Sp substituted by two polymerizable groups P at the same or different positions, wherein r1+r2+r3≥1, in formula I3, r4+r5≥1, and in formulas I4A to I4E, r1+r4+r5≥1, and wherein the compound comprises at least one group L which is A 11 , L 12 or L 13 .

[0221] More preferred compounds of formula I, I1-I6 are selected from the following sub-formulae:

[0222]

[0223] Among them, P, Sp, Sp(P) 2 , L 11-13 and r1-r3 have the meanings given in formula I2D or one of the preferred meanings given above and below, c is 0 or 1, and the compound contains x representing C m -Alkenyl group L 11 , L 12 or L 13 , wherein x is 1, 2, 3 or 4, and m is an integer from 2 to 7,

[0224] And wherein in formula I * In A, preferably in formula I * A, I * B, I * C and I * In D, c+x+m≥4, preferably 4, 5, 6, 7 or 8, and very preferably 4, 5 or 6.

[0225] More preferred are formula I, I1 to I6, I * A to I * The compounds of D and I1A-I6C are selected from the following sub-formulas:

[0226]

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247]

[0248]

[0249]

[0250]

[0251]

[0252]

[0253]

[0254]

[0255]

[0256]

[0257]

[0258]

[0259]

[0260]

[0261]

[0262]

[0263]

[0264]

[0265]

[0266]

[0267]

[0268]

[0269]

[0270]

[0271]

[0272]

[0273]

[0274]

[0275]

[0276] Among them, P, Sp, Sp(P) 2 , A and L have the meanings given in formula I or one of the preferred meanings given above and below, L is preferably F, Cl or CN, and A is preferably -CH=CH 2 、-CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH2 or -C(CH 3 )=CH 2 .

[0277] More preferred formulas I, I1 to I6, I * A to I * D, compounds of I1A to I6C and I1A-1 to I6C-3 are selected from the following sub-formulas:

[0278]

[0279]

[0280]

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291]

[0292]

[0293]

[0294]

[0295]

[0296]

[0297]

[0298]

[0299]

[0300]

[0301]

[0302]

[0303]

[0304]

[0305]

[0306]

[0307]

[0308]

[0309]

[0310]

[0311]

[0312]

[0313]

[0314]

[0315]

[0316]

[0317]

[0318]

[0319]

[0320]

[0321]

[0322]

[0323]

[0324]

[0325]

[0326]

[0327]

[0328]

[0329]

[0330]

[0331]

[0332]

[0333]

[0334]

[0335]

[0336]

[0337]

[0338]

[0339]

[0340]

[0341]

[0342]

[0343]

[0344]

[0345]

[0346]

[0347]

[0348]

[0349]

[0350]

[0351]

[0352]

[0353]

[0354]

[0355]

[0356]

[0357]

[0358]

[0359]

[0360]

[0361]

[0362]

[0363]

[0364]

[0365]

[0366]

[0367]

[0368]

[0369]

[0370]

[0371]

[0372]

[0373]

[0374]

[0375]

[0376]

[0377]

[0378]

[0379]

[0380]

[0381]

[0382]

[0383]

[0384]

[0385]

[0386]

[0387] (including four reactants)

[0388] Among them, A, P, Sp and Sp(P) 2 has the meaning given in formula I or one of the preferred meanings given above and below, and A is preferably -CH=CH 2 、-CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 .

[0389] Preferred compounds of formulae I1A-1-1 to I6C-2-3 are those in which all groups Sp are single bonds. More preferred compounds of formulae I1A-1-1 to I6C-2-3 are those in which one of the groups Sp is a single bond and the other groups Sp are different from single bonds.

[0390] More preferred compounds of formulae I1A-1-1 to I6C-2-3 are those in which A represents -CH=CH 2 、-CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 Those.

[0391] More preferred compounds of formulae I1A-1-1 to I6C-2-3 are those in which A represents C 3-7 Alkenyl, preferably -CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 Those.

[0392] More preferred compounds of formulae I1A-1-1 to I6C-2-3 are those in which L represents F, Cl, CN or OCH 3 , very preferably those of F.

[0393] More preferred compounds of the formulae I1A-1-1 to I6C-2-3 are those in which P represents an acrylate or methacrylate group, very preferably a methacrylate group.

[0394] More preferred compounds of the formulae I1A-1-1 to I6C-2-3 are those in which Sp, when it is different from a single bond, represents an alkylene radical having 2 to 6 C atoms.

[0395] Preferred compounds of formula I and II and subformulae thereof are selected from the following preferred embodiments, including any combination thereof:

[0396] - the compound comprises two or more groups A,

[0397] - said compound comprises one or more groups A and one or more groups L,

[0398] - the compound comprises three or more, preferably three or four, unfused or fused benzene rings,

[0399] The compound comprises at least one group A which is an alkenyl group having 3 to 7, preferably 3, 4 or 5 C atoms, preferably -CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 ,

[0400] -A is alkenyl having 3 to 7, preferably 3, 4 or 5 C atoms, preferably -CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3)=CH 2 ,

[0401] -A is an alkenyl group having 2 to 4 C atoms, preferably -CH=CH 2 、-CH 2 -CH=CH 2 、-CH=CH-CH 3 、-CH=CH-CH=CH 2 or -C(CH 3 )=CH 2 ,

[0402] - the compound contains exactly two polymerizable groups (represented by the group P),

[0403] - the compound comprises at least three, preferably exactly three, polymerizable groups (represented by the group P),

[0404] - P is selected from acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate,

[0405] -P is a methacrylate group,

[0406] -Pg is a hydroxyl group,

[0407] - all groups Sp are single bonds,

[0408] - at least one group Sp is a single bond, and at least one group Sp is different from a single bond,

[0409] -When different from a single bond, Sp is -(CH 2 ) p2 -、-(CH 2 ) p2 -O-、-(CH 2 ) p2 -CO-O-, -(CH 2 ) p2 -O-CO-, wherein p2 is 2, 3, 4, 5 or 6, and the O-atom or CO-group is respectively attached to the benzene ring,

[0410] -Sp is a single bond or represents -(CH 2 ) p2 -、-(CH 2 ) p2 -O-、-(CH 2 ) p2 -CO-O-, -(CH 2 ) p2 -O-CO-, wherein p2 is 2, 3, 4, 5 or 6, and the O-atom or CO-group is respectively attached to the benzene ring,

[0411] -Sp(P) 2 Selected from subformulae Sp1a-Sp3a,

[0412] -R b Indicates P-Sp-,

[0413] -R b does not represent or contain a polymerizable group,

[0414] -R b does not represent or contain a polymerizable group and represents a straight-chain, branched or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 -group is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O- and / or S-atoms are not directly attached to one another, and wherein one or more H atoms are each optionally replaced by F or Cl,

[0415] -L and L 14-16 is selected from F, Cl, CN, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, each having 1 to 6 C atoms, wherein one or more H atoms may optionally be replaced by F or Cl, preferably F, Cl, CN or OCH 3 , F is highly preferred.

[0416] Very preferred compounds of formula I and its subformulae are selected from the following subformulae:

[0417]

[0418]

[0419]

[0420]

[0421]

[0422]

[0423] (including four reactants)

[0424] Preferably, the LC media according to the invention comprise one or more self-aligning additives of the formula II.

[0425] Suitable SA additives for inducing homeotropic alignment, in particular for SA-VA mode displays, are disclosed, for example, in US 2013 / 0182202 A1, US 2014 / 0838581 A1, US 2015 / 0166890 A1, and US 2015 / 0252265 A1.

[0426] Self-aligning additives containing polymerisable groups can be polymerised in the LC medium under similar conditions as applied to the RMs in the PSA process.

[0427] Preferably, in the self-aligning additive of formula II, the MES group comprises two or more rings selected from aromatic, alicyclic and heterocyclic groups as defined above, including their preferred meanings. The most preferred ring is 1,4-phenylene, which may be replaced by L as defined below: 12 and P-Sp-substituted, or 1,4-cyclohexylene.

[0428] In formula II, the MES group is preferably a group selected from the following structures, which may be substituted by any substituent L 12 and P-Sp-mono- or polysubstituted:

[0429]

[0430]

[0431]

[0432] in

[0433] L 12 represents, in each case independently of one another, F, Cl, Br, I, -CN, -NO 2 ,-NCO,-NCS,-OCN,-SCN,-C(=O)N(R 0 ) 2 , -C(=O)R 0 , optionally substituted silyl, optionally substituted aryl or cycloalkyl having 3 to 20 C atoms or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having up to 25 C atoms, where in addition one or more H atoms may each be replaced by F or Cl,

[0434] P represents a polymerizable group, and

[0435] Sp represents a spacer group or a single bond,

[0436] And the dotted line represents the polar anchoring group R a attachment point.

[0437] Preferably, the self-aligning additive for vertical alignment is selected from Formula IIa

[0438] R 21 -[A 22 -Z 22 ] m2 -A 22 -Ra IIa

[0439] in

[0440] A 21 , A 22 each independently of one another represents an aromatic, heteroaromatic, alicyclic or heterocyclic radical which may also contain fused rings and which may also be replaced by a radical L 12 or -Sp-P is singly or polysubstituted,

[0441] L 12 represents, in each case independently of one another, F, Cl, Br, I, -CN, -NO 2 ,-NCO,-NCS,-OCN,-SCN,-C(=O)N(R 0 ) 2 , -C(=O)R 0 , optionally substituted silyl, optionally substituted aryl or cycloalkyl having 3 to 20 C atoms or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having up to 25 C atoms, where in addition one or more H atoms may each be replaced by F or Cl,

[0442] P represents a polymerizable group,

[0443] Sp represents a spacer group or a single bond,

[0444] Z 22 represents, in each case independently of one another, a single bond, -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH 2 -,-CH 2 O-, -SCH 2 -,-CH 2 S-, -CF 2 O-, -OCF 2 -, -CF 2 S-, -SCF 2 -,-(CH 2 ) n1 -, -CF 2 CH 2 -,-CH 2 CF 2 -,-(CF 2 ) n1 -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, -(CR 0 R 00 ) n1 -,-CH(-Sp-P)-,-CH2 CH-(-Sp-P)-, or -CH(-Sp-P)CH(-Sp-P)-,

[0445] n1 means 1, 2, 3 or 4,

[0446] m2 means 1, 2, 3, 4, 5 or 6,

[0447] R 0 represents in each case independently of one another an alkyl radical having 1 to 12 C atoms,

[0448] R 00 in each case independently of one another represents H or alkyl having 1 to 12 C atoms,

[0449] R 21 independently of one another represent H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein in addition, one or more non-adjacent CH 2 groups may each be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O- in such a way that the O and / or S atoms are not directly connected to one another, and wherein in addition one or more H atoms may each be replaced by F or Cl, or a P-Sp- group, and

[0450] R a As defined above, preferably refers to a polar anchoring group, which is further defined as having at least one selected from -OH, -NH 2 , -NHR 22 , C(O)OH and -CHO groups, where R 22 represents an alkyl group having 1 to 12 C atoms.

[0451] In a further preferred embodiment, the LC medium or polymer-stabilized SA-VA display according to the invention comprises one or more self-aligning additives selected from Table E below.

[0452] Anchoring group R of self-aligning additive a More preferably, the anchoring group is defined as

[0453]

[0454] or

[0455]

[0456] in

[0457] p means 1 or 2,

[0458] q means 2 or 3,

[0459] B represents a substituted or unsubstituted ring system or a condensed ring system, preferably a ring system selected from benzene, pyridine, cyclohexane, dioxane or tetrahydropyran,

[0460] Y represents, identically or differently on each occurrence, -O-, -S-, -C(O)-, -C(O)O-, -OC(O)-, -NR 11 - or single key,

[0461] o means 0 or 1,

[0462] X 1 represents, identically or differently on each occurrence, H, alkyl, fluorinated alkyl, OH, NH 2 , NHR 22 , NR 22 2 , OR 22 , C(O)OH, or -CHO,

[0463] At least one group X 1 It represents a group consisting of -OH, -NH 2 , -NHR 22 , C(O)OH, and -CHO groups,

[0464] R 22 denotes an alkyl group having 1 to 12 C atoms,

[0465] Sp a , Sp c , Sp d each independently of one another represents a spacer group or a single bond, and

[0466] Sp b represents a tri- or tetravalent group, preferably CH, N or C.

[0467] Formulae II and IIa optionally include polymerizable compounds. In the present application, "a medium comprising a compound of formula II / IIa" refers to both a medium comprising a compound of formula II / IIa and a medium which alternatively comprises a polymerized form of said compound.

[0468] In case one or more compounds of formula II are substituted by one or more polymerisable groups (-Sp-P), the LC media according to the invention comprise

[0469] a polymerizable component A) comprising, preferably consisting of, polymerizable compounds, at least one of which is a compound of formula I and at least one of which is a compound of formula II,

[0470] - Liquid-crystalline component B), hereinafter also referred to as "LC host mixture", comprises, preferably consists of, one or more mesogenic or liquid-crystalline compounds.

[0471] In the compounds of formula IIa and its subformulae, Z 22 Preferably represents a single bond, -C 2 H 4 -, -CF 2 O- or -CH 2 In a particularly preferred embodiment, Z 22 Represents a single bond.

[0472] In the compounds of formula IIa, the group L 12 Preferably, independently in each case, it represents F or alkyl, preferably CH 3 , C 2 H 5 or C 3 H 7 .

[0473] Preferred compounds of formula IIa are illustrated by the following sub-formulae II-A to II-D

[0474]

[0475] Where R 21 , R a , A 22 , Z 22 , Sp, P and L 12 has the meaning defined above for Formula IIa,

[0476] m2 is independently 1, 2 or 3, and

[0477] r1 is independently 0, 1, 2, 3, or 4, preferably 0, 1 or 2.

[0478] In the compounds of formula II-A to II-D, L 12 Preferably represents F or alkyl, preferably CH 3 , C 2 H 5 or C 3 H 7 .

[0479] In a preferred embodiment, r1 represents 0.

[0480] The polymerizable group P of formula II, IIa, II-A to II-D is preferably a methacrylate group, an acrylate group or other substituted acrylate groups, most preferably a methacrylate group.

[0481] In the above and below, in formula IIa or II-A to II-D and their subformulae, Z 22 Preferably, each independently represents a single bond or -CH 2 CH 2-, and very specifically represents a single bond.

[0482] R a Preferred representation

[0483]

[0484] in

[0485] p is 1, 2, 3, 4, 5 or 6,

[0486] x is 1 or 0, preferably 1, and

[0487] R 23 is H, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl or -CH 2 CH 2 - tert-butyl,

[0488] R a Preferably represents -O(CH 2 ) 2 -OH, -O(CH 2 ) 3 -OH,

[0489]

[0490]

[0491] In Formula IIa and subformulas of Formula IIa, R 21 Preferably, it represents a straight-chain alkyl group or a branched alkyl group having 1 to 8 C atoms, preferably a straight-chain alkyl group. 1 More preferably, CH 3 , C 2 H 5 , nC 3 H 7 , nC 4 H 9 , nC 5 H 11 , nC 6 H 13 or CH 2 CH(C 2 H 5 )C 4 H 9 . R 21 It may also represent alkenyloxy, in particular OCH 2 CH=CH 2 , OCH 2 CH=CHCH 3 , OCH 2 CH=CHC2 H 5 or alkoxy, especially OC 2 H 5 , O.C. 3 H 7 , O.C. 4 H 9 , O.C. 5 H 11 and OC 6 H 13 R is particularly preferred 21 represents a straight chain alkyl group, preferably C 5 H 11 .

[0492] In a preferred embodiment of the present invention, the LC medium comprises a polymerisable compound of the formula II.

[0493] Combinations of the following polymerizable additives of formulae I and II are preferred:

[0494] - the LC medium comprises one or more compounds selected from the group consisting of formulae I1 to I6, preferably from the group consisting of formulae I1A to I6C, more preferably from the group consisting of formulae I1A-1 to I6C-3, very preferably from the group consisting of formulae I1A-1-1 to I6C-2-3, most preferably from the group consisting of formulae I-1 to I-30, and one or more compounds of formula II;

[0495] - the LC medium comprises one or more compounds selected from the group consisting of formulae I1 to I6, preferably from the group consisting of formulae I1A to I6C, more preferably from the group consisting of formulae I1A-1 to I6C-3, very preferably from the group consisting of formulae I1A-1-1 to I6C-2-3, most preferably from the group consisting of formulae I-1 to I-30, and one or more compounds of formula II-A or II-B;

[0496] -LC medium comprises one or more compounds selected from formulae I1 to I6, preferably from formulae I1A to I6C, more preferably from formulae I1A-1 to I6C-3, very preferably from formulae I1A-1-1 to I6C-2-3, most preferably from formulae I-1 to I-30, and one or more compounds of formula II-B.

[0497] The compounds of the formula I and its subformulae and their intermediates can be prepared analogously to the methods known to the person skilled in the art and described in standard texts of organic chemistry (eg in Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Thieme-Verlag, Stuttgart).

[0498] For example, compounds of the formula I can be synthesized by esterification or etherification of intermediates using corresponding acids, acid derivatives or halogenated compounds containing a polymerizable group P, wherein the group Sp-P represents OH.

[0499] For example, acrylic acid esters or methacrylic acid esters can be prepared by esterification of the corresponding alcohol with an acid derivative, for example (meth)acryloyl chloride or (meth)acrylic anhydride, in the presence of a base, such as pyridine or triethylamine and 4-(N,N-dimethylamino)pyridine (DMAP). Alternatively, the esters can be prepared by esterification of the alcohol with (meth)acrylic acid in the presence of a dehydrating agent, for example according to Steglich with dicyclohexylcarbodiimide (DCC), N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) or N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and DMAP.

[0500] Further suitable methods are shown in the Examples.

[0501] To produce PSA displays, the polymerisable compounds contained in the LC medium are polymerised or crosslinked (if one compound comprises two or more polymerisable groups) by polymerisation in situ in the LC medium (between the substrates of the LC display), optionally while applying a voltage to the electrodes.

[0502] The structure of the PSA display according to the invention corresponds to the usual geometry of PSA displays, as described in the prior art cited at the outset. Geometries without protrusions are preferred, wherein in addition, in particular those in which the electrode on the color filter side is unstructured and only the electrode on the TFT side has slots. A particularly suitable and preferred electrode structure for PS-VA displays is described, for example, in US 2006 / 0066793 A1.

[0503] A preferred PSA-type LC display according to the invention comprises:

[0504] - a first substrate comprising a pixel electrode defining a pixel area (the pixel electrode being connected to a switching element arranged in each pixel area and optionally comprising a micro slit pattern), and optionally a first alignment layer arranged on the pixel electrode,

[0505] a second substrate comprising a common electrode layer (which may be arranged on the entire portion of the second substrate facing the first substrate), and optionally a second alignment layer,

[0506] - an LC layer arranged between the first and the second substrate and comprising an LC medium comprising a polymerisable component A and a liquid crystal component B as described above and below, wherein the polymerisable component A may also be polymeric.

[0507] The first and / or second alignment layer controls the alignment direction of the LC molecules of the LC layer. For example, in a PS-VA display, the alignment layer is selected so as to impart a homeotropic (or vertical) alignment (i.e. perpendicular to the surface) or a tilted alignment to the LC molecules. Such an alignment layer may, for example, comprise polyimide, which may also be rubbed, or may be prepared by a photoalignment method.

[0508] The LC layer with the LC medium can be deposited between the substrates of the display by methods conventionally used by display manufacturers, such as the so-called one drop fill (ODF) method. The polymerizable components of the LC medium are then polymerized, for example by UV photopolymerization. The polymerization can be carried out in one step or in two or more steps.

[0509] A PSA display may include further elements such as colour filters, a black matrix, a passivation layer, an optical retardation layer, transistor elements for addressing the individual pixels etc., all of which are well known to those skilled in the art and may be used without inventive skill.

[0510] Those skilled in the art can design the electrode structure depending on the individual display type. For example, for a PS-VA display, multi-domain orientation of the LC molecules can be induced by providing electrodes with slits and / or bumps or protrusions to produce two, four or more differently tilted alignment directions.

[0511] After polymerization, the polymerizable compound forms a cross-linked polymer which results in a certain tilt of the LC molecules in the LC medium. Without wishing to be bound by a particular theory, it is believed that at least a portion of the cross-linked polymer formed by the polymerizable compound will phase separate or precipitate out of the LC medium and form a polymer layer on the substrate or electrode, or on an alignment layer provided thereon. Microscopic measurement data (such as SEM and AFM) have confirmed that at least a portion of the formed polymer accumulates at the LC / substrate interface.

[0512] The polymerization can be carried out in one step. It is also possible to first carry out the polymerization in a first step (optionally with simultaneous application of a voltage) in order to produce the tilt angle and then polymerize or crosslink the compounds that did not react in the first step in a second polymerization step without application of a voltage ("final curing").

[0513] Suitable and preferred polymerisation methods are, for example, thermal or photopolymerisation, preferably photopolymerisation, in particular UV-induced photopolymerisation, which can be achieved by exposing the polymerisable compound to UV radiation.

[0514] Optionally, one or more polymerization initiators are added to the LC medium. Suitable conditions for the polymerization and suitable types and amounts of initiators are known to the person skilled in the art and are described in the literature. Suitable for free-radical polymerization are, for example, commercially available photoinitiators or (Ciba AG). If a polymerization initiator is used, its proportion is preferably from 0.001 to 5% by weight, particularly preferably from 0.001 to 1% by weight.

[0515] The polymerizable compounds according to the invention are also suitable for polymerization without initiators, which is accompanied by considerable advantages, such as low material costs and in particular less contamination of the LC medium by possible residual amounts of initiators or their degradation products. The polymerization can therefore also be carried out without adding initiators. In a preferred embodiment, the LC medium therefore contains no polymerization initiator.

[0516] The LC medium may also contain one or more stabilizers in order to prevent undesired spontaneous polymerization of the RMs, for example during storage or transportation. Suitable types and amounts of stabilizers are known to the person skilled in the art and are described in the literature. Particularly suitable are, for example, the commercially available series (Ciba AG), such as 1076. If stabilizers are used, their proportion is preferably 10 to 50,000 ppm, particularly preferably 50 to 5,000 ppm, based on the total amount of RM or polymerizable component (component A).

[0517] In a preferred embodiment, the liquid crystal medium comprises one or more chiral dopants, preferably in a concentration of 0.01 to 1% by weight, very preferably 0.05 to 0.5% by weight. The chiral dopant is preferably selected from the compounds of Table B below, very preferably selected from R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011 and R- or S-5011.

[0518] In a further preferred embodiment, the liquid-crystalline medium comprises the racemate of one or more chiral dopants, which are preferably selected from the chiral dopants mentioned in the previous paragraph.

[0519] In another preferred embodiment of the present invention, the liquid-crystalline medium comprises one or more further stabilizers, preferably selected from the group consisting of

[0520]

[0521] where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings:

[0522] R a-d is a straight-chain or branched alkyl radical having 1 to 10, preferably 1 to 6, very preferably 1 to 4 C atoms, most preferably methyl,

[0523] X S H, CH 3, OH or O ● ,

[0524] A S is a linear, branched or cyclic alkylene radical having 1 to 20 C atoms, which is optionally substituted,

[0525] n is an integer of 1 to 6, preferably 3.

[0526] Preferred stabilizers of formula S3 are selected from formula S3A

[0527]

[0528] wherein n2 is an integer from 1 to 12, and wherein the group (CH 2 ) n2 One or more H atoms in are optionally replaced by methyl, ethyl, propyl, butyl, pentyl or hexyl.

[0529] Very preferred stabilizers are selected from the following formula

[0530]

[0531]

[0532]

[0533] In a preferred embodiment, the liquid crystal medium comprises one or more stabilizers selected from the group consisting of formulae S1-1, S2-1, S3-1, S3-1 and S3-3.

[0534] In a preferred embodiment, the liquid crystal medium comprises one or more stabilizers selected from Table D.

[0535] Preferably, the proportion of stabilizers analogous to the formulae S1 to S3 in the liquid-crystalline medium is from 10 to 500 ppm, very preferably from 20 to 100 ppm.

[0536] In another preferred embodiment, the LC medium according to the invention comprises one or more SA additives selected from formula II or its subformulae. The concentration of the SA additive in the LC medium is preferably 0.1% to 5%, very preferably 0.2% to 3%, most preferably 0.2% to 1.5%.

[0537] In a preferred embodiment, the LC medium or display according to the invention comprises one or more SA additives selected from Table F below.

[0538] In another preferred embodiment, the SA-VA or SA-FFS display according to the invention comprises no polyimide alignment layer.

[0539] The polymerizable compounds of the formula I do in particular show good UV absorption and are therefore particularly suitable for use in a process for the production of PSA displays comprising one or more of the following features:

[0540] - in the display the polymerizable medium is exposed to UV light in a 2-step process comprising a first UV exposure step ("UV-1 step") to produce the tilt angle, and a second UV exposure step ("UV-2 step") to complete the polymerization,

[0541] - The polymerizable medium is exposed in the display to UV light generated by energy-saving UV lamps (also called "green UV lamps"). These lamps are characterized by relatively low intensities (1 / 100-1 / 10 of conventional UV1 lamps) in their absorption spectrum of 300-380 nm and are preferably used in the UV2 step, but are also optionally used in the UV1 step when avoiding high intensities is essential for the process.

[0542] - In the display the polymerizable medium is exposed to UV light generated by a UV lamp having a radiation spectrum shifted to longer wavelengths, preferably 340 nm or longer, in order to avoid the short UV light exposure in the PS-VA process.

[0543] Both low intensity and UV shifted to longer wavelengths are used to protect the organic layers from damage that could be caused by UV light.

[0544] A preferred embodiment of the present invention relates to a method for producing a PSA display as described above and below, comprising one or more of the following features:

[0545] - the polymerisable LC medium is exposed to UV light in a 2-step process comprising a first UV exposure step ("UV-1 step") to produce the tilt angle, and a second UV exposure step ("UV-2 step") to complete the polymerisation,

[0546] The polymerizable LC medium is exposed to a UV lamp with a power of 0.5 mW / cm 2 Up to 10mW / cm 2 UV light in the wavelength range of 300-380 nm with an intensity of 1000 nm, preferably for the UV2 step, and optionally also for the UV1 step,

[0547] - The polymerisable LC medium is exposed to UV light having a wavelength of 340 nm or longer, and preferably 400 nm or shorter.

[0548] This preferred method is performed, for example, by using a desired UV lamp, or by using a bandpass filter and / or a cutoff filter, which is substantially transmissive for UV light having a corresponding desired wavelength and substantially blocks UV light having a corresponding undesirable wavelength. For example, when radiation with a UV light having a wavelength λ of 300-400 nm is desired, the UV exposure can be performed using a broad bandpass filter that is substantially transmissive for a wavelength of 300 nm <λ <400 nm. When radiation with a UV light having a wavelength λ greater than 340 nm is desired, the UV exposure can be performed using a cutoff filter that is substantially transmissive for a wavelength of λ>340 nm.

[0549] "Substantially transmit" means that the filter transmits a majority, preferably at least 50%, of the intensity of incident light of a desired wavelength. "Substantially block" means that the filter does not transmit a majority, preferably at least 50%, of the intensity of incident light of an undesired wavelength. "Desired (undesired) wavelengths" means, for example, wavelengths within (outside) a given λ range in the case of a bandpass filter and wavelengths above (below) a given λ value in the case of a cutoff filter.

[0550] This preferred method makes it possible to manufacture displays by using longer UV wavelengths, thereby reducing or even avoiding the harmful and damaging effects of the short UV light component.

[0551] The UV radiation energy is usually 6 to 100 J, depending on the production process conditions.

[0552] The LC medium according to the invention preferably does consist essentially of a polymerisable component A), or one or more polymerisable compounds of formula I as described above and below, and a LC component B), or a LC host mixture. However, the LC medium may additionally comprise one or more other components or additives, preferably selected from the list including, but not limited to, comonomers, chiral dopants, polymerisation initiators, inhibitors, stabilisers, surfactants, wetting agents, lubricants, dispersants, hydrophobic agents, binders, flow improvers, defoamers, deaerators, diluents, reactive diluents, auxiliaries, colourants, dyes, pigments and nanoparticles.

[0553] Particular preference is given to LC media which comprise one, two or three polymerisable compounds of the formula I.

[0554] Preference is furthermore given to LC media in which the polymerizable component A) comprises only polymerizable compounds selected from the formula I, ie which do not comprise any further polymerizable compounds different from the formula I.

[0555] Preference is furthermore given to LC media in which the liquid-crystalline component B) or the LC host mixture has a nematic LC phase and preferably no chiral liquid-crystalline phase.

[0556] The LC component B) or the LC host mixture is preferably a nematic LC mixture.

[0557] Preference is furthermore given to achiral compounds of the formula I, and LC media in which the compounds of components A and / or B are selected exclusively from the group consisting of achiral compounds.

[0558] Preferably, in particular when used in SA-VA displays, the proportion of polymerizable component A) in the LC medium is from >0 to <5%, very preferably from >0 to <3%, more preferably from 0.01 to 2.0. In a further preferred embodiment, in particular when used in PSA displays, the proportion of polymerizable component A) in the LC medium is from 0.01 to 1.0%, most preferably from 0.01 to 0.5%.

[0559] Preferably, in particular when used in SA-VA displays, the proportion of compounds of the formula I in the LC medium is >0 to <5%, very preferably >0 to <3%, more preferably 0.01 to 2.0. In a further preferred embodiment, in particular when used in PSA displays, the proportion of compounds of the formula I in the LC medium is 0.01 to 1.0%, most preferably 0.01 to 0.5%.

[0560] Preferably, the proportion of compounds of the formula II in the LC medium is from >0.1 to <5%, very preferably from >0.2 to <3%, most preferably from 0.2 to 1.5%.

[0561] Preferably, the proportion of LC component B) in the LC medium is 95 to <100%, very preferably 96.5 to <100%, most preferably 98 to <100%. In another preferred embodiment, the proportion of LC component B) in the LC medium is 99 to <100%.

[0562] In a preferred embodiment, the polymerizable compounds of the polymerizable component B) are selected from the group consisting of formula I only.

[0563] In another preferred embodiment, the polymerizable component B) comprises, in addition to the compound of the formula I, one or more further polymerizable compounds ("comonomers"), preferably selected from RMs.

[0564] Suitable and preferred mesogenic comonomers are selected from the following formula:

[0565]

[0566]

[0567]

[0568]

[0569]

[0570]

[0571] Wherein, each group has the following meaning:

[0572] P 1 , P 2 and P 3 each independently of one another represents an acrylate group or a methacrylate group,

[0573] Sp 1 、Sp 2 and Sp 3 each independently of one another represents a single bond or a spacer group (having one of the meanings as given above and below for Sp), and particularly preferably represents -(CH 2 ) p1 -、-(CH 2 ) p1 -O-、-(CH 2 ) p1 -CO-O-, -(CH 2 ) p1 -O-CO- or -(CH 2 ) p1 -O-CO-O-, wherein p1 is an integer from 1 to 12, and wherein the group P 1 -Sp 1 -、P 1 -Sp 2 - and P 3 -Sp 3 -One or more of them can represent R aa , provided that the group P 1 -Sp 1 -、P 2 -Sp 2 - and P 3 -Sp 3 - at least one of them is different from R aa ,

[0574] R aa represents H, F, Cl, CN or a straight-chain or branched alkyl radical having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 The groups may also be independently C(R 0 )=C(R 00 )-、-C≡C-、-N(R 0)-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to each other, and wherein one or more additional H atoms may be replaced by F, Cl, CN or P 1 -Sp 1 - is replaced by, particularly preferably, a straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy radical having 1 to 12 C atoms, where alkenyl and alkynyl have at least two C atoms and branched radicals have at least three C atoms,

[0575] R 0 , R 00 each independently of one another and identically or differently on each occurrence represents H or alkyl having 1 to 12 C atoms,

[0576] R y and R z Each independently represents H, F, CH 3 or CF 3 ,

[0577] X 1 , X 2 and X 3 each independently represents -CO-O-, -O-CO- or a single bond,

[0578] Z 1 Indicates -O-, -CO-, -C(R y R z )-or-CF 2 CF 2 -,

[0579] Z 2 and Z 3 Each independently represents -CO-O-, -O-CO-, -CH 2 O-、-OCH 2 -、-CF 2 O-、-OCF 2 -or-(CH 2 ) n -, where n is 2, 3 or 4,

[0580] L, on each occurrence, identically or differently, represents F, Cl, CN or linear or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, preferably F,

[0581] L' and L" each independently represent H, F or Cl,

[0582] k represents 0 or 1,

[0583] r represents 0, 1, 2, 3 or 4,

[0584] s represents 0, 1, 2 or 3,

[0585] t represents 0, 1 or 2,

[0586] x represents 0 or 1.

[0587] Particularly preferred are compounds of the formulae M2, M13, M17, M22, M23, M24, M30, M31 and M32.

[0588] More preferred are the trireactive compounds M15 to M30, in particular M17, M18, M19, M22, M23, M24, M25, M26, M30, M31 and M32.

[0589] In another preferred embodiment, the polymerizable component B) comprises, in addition to the compound of formula I, one or more comonomers selected from Table D below.

[0590] In the compounds of formulae M1 to M32, the group

[0591] Best

[0592]

[0593] wherein L has, at each occurrence, identically or differently, one of the meanings given above and below and is preferably F, Cl, CN, NO 2 , CH 3 , C 2 H 5 , C(CH 3 ) 3 、CH(CH 3 ) 2 , CH 2 CH(CH 3 )C 2 H 5 、OCH 3 , OC 2 H 5 、COCH 3 、COC 2 H 5 、COOCH 3 、COOC 2 H 5 CF 3 、OCF 3 , OCHF 2 , OC2 F 5 or P-Sp-, very preferably F, Cl, CN, CH 3 , C 2 H 5 、OCH 3 、COCH 3 、OCF 3 or P-Sp-, more preferably F, Cl, CH 3 、OCH 3 、COCH 3 or OCF 3 , especially F or CH 3 .

[0594] In addition to the polymerisable compounds described above, the LC medium for the LC display according to the invention comprises an LC mixture ("host mixture") comprising one or more, preferably two or more, LC compounds selected from non-polymerisable, low molecular weight compounds. These LC compounds are selected such that they are stable and / or unreactive towards polymerisation reactions under the conditions applied to the polymerisation of the polymerisable compounds.

[0595] In principle, any LC mixture suitable for conventional displays is suitable as host mixture. Suitable LC mixtures are known to the person skilled in the art and are described in the literature, for example in EP 1 378 557 A1 for mixtures in VA displays and in EP 1 306 418 A1 and DE 102 24 046 A1 for mixtures in OCB displays.

[0596] The polymerizable compounds of formula I are particularly suitable for LC host mixtures comprising one or more mesogens or LC compounds containing alkenyl groups (hereinafter also referred to as "alkenyl compounds"), wherein the alkenyl groups are stable to polymerization reactions under the conditions used for polymerizing the compounds of formula I and for polymerizing the other polymerizable compounds contained in the LC medium. Compared to the RMs known from the prior art, the compounds of formula I exhibit improved properties in such LC host mixtures, such as solubility, reactivity or the ability to generate a tilt angle.

[0597] Thus, the LC media according to the invention comprise, in addition to the polymerisable compounds of formula I, one or more mesogenic or liquid-crystalline compounds containing an alkenyl group ("alkenyl compounds"), wherein this alkenyl group is preferably stable to polymerization under the conditions used for polymerising the polymerisable compounds of formula I or for polymerising other polymerisable compounds comprised in the LC medium.

[0598] The alkenyl group in the alkenyl compound is preferably selected from linear, branched or cyclic alkenyl groups, in particular having 2 to 25 C atoms, particularly preferably having 2 to 12 C atoms, in which one or more non-adjacent CH2 The group may be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O atoms and / or the S atoms are not directly attached to each other, and in addition, one or more H atoms may be replaced by F and / or Cl.

[0599] Preferred alkenyl groups are straight-chain alkenyl groups having 2 to 7 C atoms and cyclohexenyl groups, in particular ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, 1,4-cyclohex-1-yl and 1,4-cyclohex-3-yl.

[0600] The concentration of the alkenyl-containing compound in the LC host mixture (ie without any polymerisable compound) is preferably from 5% to 100%, very preferably from 20% to 60%.

[0601] Particularly preferred are LC mixtures containing 1 to 5, preferably 1, 2 or 3, compounds having alkenyl groups.

[0602] Mesogenic and LC compounds containing alkenyl groups are preferably selected from the group consisting of formulae AN and AY as defined below.

[0603] In addition to the polymerizable component A) as described above, the LC media according to the invention comprise an LC component B) or an LC host mixture comprising one or more, preferably two or more, LC compounds selected from non-polymerizable low molecular weight compounds. These LC compounds are selected such that they are stable and / or unreactive towards polymerization reactions under the conditions applied to the polymerization of the polymerizable compounds.

[0604] In a first preferred embodiment, the LC medium contains an LC component B) or an LC host mixture based on compounds with negative dielectric anisotropy. This LC medium is particularly suitable for PS-VA and PS-UB-FFS displays. Particularly preferred embodiments of this LC medium are those of the following sections a) to z3):

[0605] a) LC media wherein component B) or the LC host mixture comprises one or more compounds selected from the group consisting of the formulae CY and PY:

[0606]

[0607] in

[0608] a means 1 or 2,

[0609] b represents 0 or 1,

[0610] express

[0611] R 1 and R 2each independently of one another represents an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2 The radical may also be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to one another, preferably an alkyl or alkoxy radical having 1 to 6 carbon atoms,

[0612] Z x and Z y Each independently represents -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -, -CF=CF-, -CH=CH-CH 2 O- or a single bond, preferably a single bond,

[0613] L 1-4 Each independently represents F, Cl, OCF 3 CF 3 , CH 3 , CH 2 F. CHF 2 .

[0614] Preferably, L 1 and L 2 Both represent F, or L 1 and L 2 One of them represents F and the other represents Cl, or L 3 and L 4 Both represent F, or L 3 and L 4 One of them represents F and the other represents Cl.

[0615] The compound of formula CY is preferably selected from the group consisting of the following subformulae:

[0616]

[0617]

[0618]

[0619]

[0620]

[0621] Where a represents 1 or 2, alkyl and alkyl * each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond. alkenyl preferably represents CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0622] The compound of formula PY is preferably selected from the group consisting of the following subformulae:

[0623]

[0624]

[0625]

[0626] Among them, alkyl and alkyl * each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 C atoms, and (O) represents an oxygen atom or a single bond. alkenyl preferably represents CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0627] b) LC medium, wherein the component B) or the LC host mixture comprises one or more mesogens or LC compounds containing alkenyl groups (hereinafter also referred to as "alkenyl compounds"), wherein the alkenyl groups are stable to polymerization under the polymerization conditions used for the polymerizable compounds contained in the LC medium.

[0628] Preferably, component B) or the LC host mixture comprises one or more alkenyl compounds selected from the group consisting of formula AN and AY

[0629]

[0630] The individual radicals have the following meanings on each occurrence, identically or differently and independently of one another:

[0631] express

[0632]

[0633] express

[0634]

[0635] express

[0636]

[0637] R A1 is alkenyl having 2 to 9 C atoms, or, if at least one of the rings X, Y and Z represents cyclohexenyl, then R A1 Also has R A2 One of the meanings,

[0638] R A2 is an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2 The group may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to each other,

[0639] Z x -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F4 -, -CF=CF-, -CH=CH-CH 2 O-, or a single bond, preferably a single bond,

[0640] L 1,2 H, F, Cl, OCF 3 CF 3 , CH 3 , CH 2 F or CHF 2 H, preferably H, F or Cl,

[0641] x is 1 or 2,

[0642] z is 0 or 1.

[0643] Preferred compounds of formula AN and AY are those wherein R A2 Those selected from ethenyl, propenyl, butenyl, pentenyl, hexenyl and heptenyl.

[0644] In a preferred embodiment, component B) or the LC host mixture comprises one or more compounds of formula AN selected from the following subformulae:

[0645]

[0646]

[0647] Among them, alkyl and alkyl * each independently of one another represents a straight-chain alkyl group having 1 to 6 C atoms, and alkenyl and alkenyl * each independently of one another represents a straight-chain alkenyl radical having 2 to 7 C atoms. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0648] Preferably, component B) or the LC host mixture comprises one or more compounds selected from the group consisting of formulae AN1, AN2, AN3 and AN6, very preferably one or more compounds of formula AN1.

[0649] In another preferred embodiment, component B) or the LC host mixture comprises one or more compounds of formula AN selected from the following subformulae:

[0650]

[0651]

[0652] Where m represents 1, 2, 3, 4, 5 or 6, i represents 0, 1, 2 or 3, and R b1 Represents H, CH 3 or C 2 H 5 .

[0653] In another preferred embodiment, component B) or the LC host mixture comprises one or more compounds selected from the following sub-formulae:

[0654]

[0655] Most preferred are compounds of formula AN1a2 and AN1a5.

[0656] In another preferred embodiment, component B) or the LC host mixture comprises one or more compounds of formula AY selected from the following subformulae:

[0657]

[0658]

[0659]

[0660]

[0661]

[0662] Among them, alkyl and alkyl * Each independently represents a straight-chain alkyl group having 1 to 6 C atoms, "(O)" represents an O-atom or a single bond, and alkenyl and alkenyl * each independently of one another represents a straight-chain alkenyl radical having 2 to 7 C atoms. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0663] In another preferred embodiment, component B) or the LC host mixture comprises one or more compounds of formula AY selected from the following subformulae:

[0664]

[0665]

[0666] wherein m and n each independently represent 1, 2, 3, 4, 5 or 6, and alkenyl represents CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0667] Preferably, the proportion of compounds of the formulae AN and AY in the LC medium is 2 to 70 wt %, very preferably 5 to 60 wt %, most preferably 10 to 50 wt %.

[0668] Preferably, the LC medium or LC host mixture contains 1 to 5, preferably 1, 2 or 3 compounds selected from the group consisting of formulae AN and AY.

[0669] In another preferred embodiment of the invention, the LC medium comprises one or more compounds of the formula AY14, very preferably AY14a. The proportion of compounds of the formula AY14 or AY14a in the LC medium is preferably from 3 to 20% by weight.

[0670] The addition of alkenyl compounds of the formula AN and / or AY enables the viscosity and the response time of the LC medium to be reduced.

[0671] c) LC media wherein component B) or the LC host mixture comprises one or more compounds of the formula:

[0672]

[0673] The various groups have the following meanings:

[0674] express

[0675]

[0676] express

[0677] R 3 and R 4 each independently of one another represents an alkyl radical having 1 to 12 C atoms, in addition to which one or two non-adjacent CH 2 The group may be replaced by -O-, -CH=CH-, -CO-, -O-CO- or -CO-O- in such a way that the O atoms are not directly attached to each other,

[0678] Z y Indicates -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -, -CF=CF-, -CH=CH-CH 2 O- or a single bond, preferably a single bond.

[0679] The compound of formula ZK is preferably selected from the group consisting of the following subformulae:

[0680]

[0681]

[0682] Among them, alkyl and alkyl* each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 C atoms. 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0683] Especially preferred are compounds of formula ZK1.

[0684] Particularly preferred compounds of formula ZK are selected from the following sub-formulae:

[0685]

[0686] Among them, propyl, butyl and pentyl are straight chain groups.

[0687] Most preferred are compounds of formula ZK1a.

[0688] d) LC media wherein component B) or the LC host mixture additionally comprises one or more compounds of the formula:

[0689]

[0690] where the individual radicals have the following meanings on each occurrence, identically or differently:

[0691] R 5 and R 6 each independently of one another represents an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2 The radical may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to one another, preferably by alkyl or alkoxy having 1 to 6 C atoms,

[0692] express

[0693] express and e means 1 or 2.

[0694] The compound of formula DK is preferably selected from the group consisting of the following subformulae:

[0695]

[0696]

[0697] Among them, alkyl and alkyl * each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2 to 6 C atoms. 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0698] e) LC media wherein component B) or the LC host mixture additionally comprises one or more compounds of the formula:

[0699]

[0700] The various groups have the following meanings:

[0701] d means en means ot

[0702]

[0703] wherein at least one ring F is different from cyclohexylene,

[0704] f means 1 or 2,

[0705] R 1 and R 2 each independently of one another represents an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2The group may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to each other,

[0706] Z x Indicates -CH 2 CH 2 -、-CH=CH-、-CF 2 O-、-OCF 2 -、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -, -CF=CF-, -CH=CH-CH 2 O- or a single bond, preferably a single bond,

[0707] L 1 and L 2 Each independently represents F, Cl, OCF 3 CF 3 , CH 3 , CH 2 F. CHF 2 .

[0708] Preferably, the group L 1 and L 2 All represent F, or group L 1 and L 2 One of them represents F and the other represents Cl.

[0709] The compound of formula LY is preferably selected from the group consisting of the following subformulae:

[0710]

[0711]

[0712]

[0713]

[0714] Where R 1 has the meaning given above, alkyl represents a straight-chain alkyl group having 1-6 C atoms, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6. 1 Preferably represents straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms, in particular CH 3 , C 2 H 5 、nC 3 H 7 、nC4 H 9 、nC 5 H 11 , CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0715] f) LC media, wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of:

[0716]

[0717] Where alkyl represents C 1-6 Alkyl, L x represents H or F, and X represents F, Cl, OCF 3 , OCHF 2 Or OCH=CF 2 Particular preference is given to compounds of the formula G1 in which X represents F.

[0718] g) LC media, wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of:

[0719]

[0720]

[0721]

[0722] Where R 5 With the above for R 1 One of the meanings given, alkyl means C 1-6 -alkyl, d represents 0 or 1, and z and m each independently represent an integer of 1 to 6. 5 Particularly preferred is C 1-6 -alkyl or -alkoxy or C 2-6-alkenyl, d is preferably 1. The LC media according to the invention preferably comprise one or more compounds of the formulae indicated above in an amount of ≥ 5% by weight.

[0723] h) LC medium, wherein component B) or the LC host mixture additionally comprises one or more biphenyl compounds selected from the group consisting of:

[0724]

[0725] Among them, alkyl and alkyl * each independently represents a straight-chain alkyl group having 1 to 6 C atoms, and alkenyl and alkenyl * each independently of one another represents a straight-chain alkenyl radical having 2 to 6 C atoms. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0726] The proportion of the biphenyls of the formulae B1 to B3 in the LC host mixture is preferably at least 3% by weight, in particular ≥5% by weight.

[0727] Compounds of the formula B2 are particularly preferred.

[0728] The compounds of the formulae B1 to B3 are preferably selected from the group consisting of the following subformulae:

[0729]

[0730] Among them, alkyl * denotes an alkyl group having 1 to 6 C atoms. The medium according to the invention particularly preferably comprises one or more compounds of the formula B1a and / or B2c.

[0731] i) LC media wherein component B) or the LC host mixture additionally comprises one or more terphenyl compounds of the formula:

[0732]

[0733] Where R 5 and R 6 Each independently has one of the meanings indicated above and

[0734] Each independently represents:

[0735]

[0736] Where L 5 represents F or Cl, preferably F, and L 6 Indicates F, Cl, OCF 3 CF 3 , CH 3 , CH 2 F or CHF 2 , preferably F.

[0737] The compound of formula T is preferably selected from the group consisting of the following subformulae:

[0738]

[0739]

[0740]

[0741] wherein R represents a straight chain alkyl or alkoxy group having 1 to 7 C atoms, R * R represents a straight-chain alkenyl group having 2 to 7 C atoms, (O) represents an oxygen atom or a single bond, and m represents an integer of 1 to 6. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0742] R preferably represents methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy or pentoxy.

[0743] The LC host mixture according to the invention preferably comprises the terphenyl of the formula T and preferred subformulae thereof, preferably in an amount of 0.5 to 30% by weight, in particular 1 to 20% by weight.

[0744] Compounds of the formulae T1, T2, T3 and T21 are particularly preferred. In these compounds, R preferably represents alkyl, and also alkoxy, each having 1 to 5 C atoms.

[0745] Terphenyls are preferably used in the LC media according to the invention if the Δn value of the mixture is ≥ 0.1. Preferred LC media comprise 2 to 20% by weight of one or more terphenyl compounds of the formula T, preferably selected from compounds T1 to T22.

[0746] k) LC medium, wherein component B) or the LC host mixture additionally comprises one or more quaternary compounds selected from the group consisting of:

[0747]

[0748] in

[0749] R Q is 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,

[0750] X Q is F, Cl, a haloalkyl or alkoxy group having 1 to 6 C atoms, or a haloalkenyl or alkenyloxy group having 2 to 6 C atoms,

[0751] L Q1 To L Q6 are independently H or F, where L Q1 To L Q6 At least one of them is F.

[0752] Preferred compounds of formula Q are those wherein R Q These represent straight-chain alkyl radicals having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

[0753] Preferred compounds of formula Q are those wherein L Q3 and L Q4 Those where L is F. Further preferred compounds of formula Q are those where L Q3 , L Q4 and L Q1 and L Q2 One or two of them are F.

[0754] Preferred compounds of formula Q are those wherein X Q Indicates F or OCF3 (Those of F are very preferred).

[0755] The compound of formula Q is preferably selected from the following sub-formula

[0756]

[0757] Where R Q has one of the meanings of the formula Q or one of its preferred meanings given above or below, and is preferably ethyl, n-propyl or n-butyl.

[0758] Particularly preferred are compounds of formula Q1, especially wherein R Q Those which are n-propyl.

[0759] Preferably, the proportion of the compound of formula Q in the LC host mixture is from >0 to ≤5% by weight, very preferably from 0.1 to 2% by weight, most preferably from 0.2 to 1.5% by weight.

[0760] Preferably, the LC host mixture contains 1 to 5 compounds of formula Q, preferably 1 or 2.

[0761] Adding quaterphenyl compounds of formula Q to LC host mixtures can reduce ODF color differences while maintaining high UV absorption, enable fast and complete polymerization, enable strong and fast tilt angle generation, and increase the UV stability of the LC medium.

[0762] Furthermore, the addition of compounds of formula Q having positive dielectric anisotropy to LC media having negative dielectric anisotropy allows for better control of the dielectric constant ε || and ε ⊥ values, especially enabling high dielectric constants ε || value while keeping the dielectric anisotropy Δε constant, thereby reducing the kickback voltage and reducing image sticking.

[0763] 1) LC media wherein component B) or the LC host mixture additionally comprises one or more compounds of the formula CC:

[0764]

[0765] in

[0766] R C represents 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,

[0767] X C represents F, Cl, a haloalkyl or alkoxy group having 1 to 6 C atoms, or a haloalkenyl or alkenyloxy group having 2 to 6 C atoms,

[0768] L C1 , L C2 represents H or F independently of each other, where L C1 and L C2 At least one of them is F.

[0769] Preferred compounds of formula CC are those wherein R C These represent straight-chain alkyl radicals having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

[0770] Preferred compounds of formula CC are those wherein L C1 and L C2 Those are F.

[0771] Preferred compounds of formula CC are those wherein X C Indicates F or OCF 3 (Those of F are very preferred).

[0772] Preferred compounds of formula CC are selected from the following

[0773]

[0774] Where R C has one of the meanings of the formula CC or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl, very preferably n-propyl.

[0775] Preferably, the proportion of the compound of the formula CC in the LC host mixture is >0 to ≤10% by weight, very preferably 0.1 to 8% by weight, most preferably 0.2 to 5% by weight.

[0776] Preferably, the LC host mixture contains 1 to 5, preferably 1, 2 or 3 compounds of formula CC.

[0777] Adding compounds of formula CC with positive dielectric anisotropy to LC media with negative dielectric anisotropy allows better control of the dielectric constant ε || and ε ⊥ values, especially enabling high dielectric constants ε || The value of CC is kept constant while keeping the dielectric anisotropy Δε constant, thus reducing the kickback voltage and reducing image sticking. In addition, the addition of compounds of formula CC can reduce the viscosity and response time of the LC medium.

[0778] m) LC medium, wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of:

[0779]

[0780]

[0781] Where R 1 and R 2 have the meanings indicated above and preferably each independently of one another represent straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms.

[0782] Preferred media comprise one or more compounds selected from the group consisting of formulae O1, O3 and O4.

[0783] n) LC media, wherein component B) or the LC host mixture additionally comprises one or more compounds of the formula:

[0784]

[0785] in express

[0786]

[0787] R 9 Indicates H, CH 3 , C 2 H 5 or nC 3 H 7 , (F) represents an optional fluorine substituent, and q represents 1, 2 or 3, and R 7 With respect to R 1 Within the meanings indicated, preferably the amount is >3% by weight, in particular ≥5% by weight, very particularly preferably 5 to 30% by weight.

[0788] Particularly preferred compounds of formula FI are selected from the group consisting of the following subformulae:

[0789]

[0790]

[0791]

[0792] Where R 7 Preferably represents a straight chain alkyl group, and R 9 Indicates CH 3 , C 2 H 5 or nC 3 H 7 Particularly preferred are compounds of the formulae FI1, FI2 and FI3.

[0793] o) LC medium, wherein component B) or the LC host mixture additionally comprises one or more compounds selected from the group consisting of:

[0794]

[0795] Where R 8 With respect to R 1 The meanings indicated, and alkyl denotes a straight-chain alkyl radical having 1 to 6 C atoms.

[0796] p) LC media, wherein component B) or the LC host mixture additionally comprises one or more compounds containing tetrahydronaphthyl or naphthyl units, for example compounds selected from the group consisting of:

[0797]

[0798]

[0799]

[0800] in

[0801] R 10 and R 11 each independently of one another represents an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2 The radical may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to one another, preferably by alkyl or alkoxy having 1 to 6 C atoms,

[0802] And R 10 and R 11 preferably represents a straight-chain alkyl or alkoxy radical having 1 to 6 C atoms, or a straight-chain alkenyl radical having 2 to 6 C atoms, and

[0803] Z 1 and Z 2 Each independently represents -C 2 H 4 -, -CH=CH-, -(CH 2 ) 4 -、-(CH 2 ) 3 O-、-O(CH 2 ) 3 -、-CH=CH-CH 2 CH 2 -、-CH 2 CH 2 CH=CH-、-CH 2 O-、-OCH 2 -、-CO-O-、-O-CO-、-C 2 F 4 -, -CF=CF-, -CF=CH-, -CH=CF-, -CH2 - or a single key.

[0804] q) LC media wherein component B) or the LC host mixture additionally comprises one or more difluorodibenzochromans and / or chromans of the following formula:

[0805]

[0806]

[0807] in

[0808] R 11 and R 12 Each independently has the above for R 11 One of the meanings pointed out is

[0809] Ring M is trans-1,4-cyclohexylene or 1,4-phenylene,

[0810] Z m Yes-C 2 H 4 -、-CH 2 O-、-OCH 2 -, -CO-O- or -O-CO-,

[0811] c is 0, 1, or 2,

[0812] Preferably the amount is 3-20 wt%, particularly 3-15 wt%.

[0813] Particularly preferred compounds of formula BC, CR and RC are selected from the group consisting of the following subformulae:

[0814]

[0815]

[0816]

[0817]

[0818] Among them, alkyl and alkyl * each independently of one another represents a straight-chain alkyl group having 1 to 6 C atoms, (O) represents an oxygen atom or a single bond, c is 1 or 2, and alkenyl and alkenyl * Each independently of one another represents a straight-chain alkenyl radical having 2 to 6 C atoms. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0819] Very particular preference is given to LC host mixtures which comprise one, two or three compounds of the formula BC-2.

[0820] r) LC medium wherein component B) or the LC host mixture additionally comprises one or more fluorinated phenanthrenes and / or dibenzofurans of the following formulae:

[0821]

[0822] Where R 11 and R 12 Each independently has the above for R 11 b represents 0 or 1, L represents F, and r represents 1, 2 or 3.

[0823] Particularly preferred compounds of formula PH and BF are selected from the group consisting of the following subformulae:

[0824]

[0825]

[0826] wherein R and R' each independently of one another represent a straight-chain alkyl or alkoxy group having 1 to 7 C atoms.

[0827] s) LC medium, wherein component B) or the LC host mixture additionally comprises one or more monocyclic compounds of the formula

[0828]

[0829] in

[0830] R 1 and R 2 each independently of one another represents an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2The radicals may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to one another, preferably alkyl or alkoxy radicals having 1 to 6 C atoms,

[0831] L 1 and L 2 Each independently represents F, Cl, OCF 3 CF 3 , CH 3 , CH 2 F. CHF 2 .

[0832] Preferably, L 1 and L 2 Both mean F or L 1 and L 2 One of them represents F and the other represents Cl,

[0833] The compound of formula Y is preferably selected from the group consisting of the following subformulae:

[0834]

[0835]

[0836] Among them, Alkyl and Alkyl * Each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, Alkoxy represents a straight-chain alkoxy radical having 1 to 6 C atoms, Alkenyl and Alkenyl * Each independently of one another represents a straight-chain alkenyl group having 2 to 6 C atoms, and O represents an oxygen atom or a single bond. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH 3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0837] Particularly preferred compounds of formula Y are selected from the group consisting of the following subformulae:

[0838]

[0839] Alkoxy preferably denotes a straight-chain alkoxy radical having 3, 4 or 5 C atoms.

[0840] t) LC medium which, apart from the polymerisable compounds as described above and below, does not contain any 2 ) compounds.

[0841] u) LC medium, wherein component B) or the LC host mixture comprises 1 to 8, preferably 1 to 5, compounds of the formula CY1, CY2, PY1 and / or PY2. The proportion of these compounds in the entire LC host mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%.

[0842] v) LC medium, wherein component B) or the LC host mixture comprises 1 to 8, preferably 1 to 5, compounds of the formula CY9, CY10, PY9 and / or PY10. The proportion of these compounds in the entire LC host mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably in each case 2 to 20%.

[0843] w) LC medium, wherein component B) or the LC host mixture comprises 1 to 10, preferably 1 to 8, compounds of the formula ZK, in particular compounds of the formula ZK1, ZK2 and / or ZK6. The proportion of these compounds in the overall LC host mixture is preferably 3 to 25%, particularly preferably 5 to 45%. The content of these individual compounds is preferably in each case 2 to 20%.

[0844] x) LC media in which the proportion of compounds of the formulae CY, PY and ZK in the overall LC host mixture is greater than 70%, preferably greater than 80%.

[0845] y) LC medium, wherein the LC host mixture contains one or more alkenyl-containing compounds, preferably selected from the formulae AN and AY, very preferably selected from the formulae AN1, AN3, AN6 and AY14, most preferably selected from the formulae AN1a, AN3a, AN6a and AY14. The concentration of these compounds in the LC host mixture is preferably 2-70%, very preferably 3-55%.

[0846] z) LC media in which component B) or the LC host mixture contains one or more, preferably 1 to 5, compounds selected from the group consisting of the formulae PY1 to PY8, very preferably the formula PY2. The proportion of these compounds in the overall LC host mixture is preferably 1 to 30%, particularly preferably 2 to 20%. The content of these individual compounds is preferably in each case 1 to 20%.

[0847] z1) LC media in which component B) or the LC host mixture contains one or more, preferably 1, 2 or 3, compounds selected from the formulae T1, T2 and T5, very preferably from the formula T2. The proportion of these compounds in the overall LC host mixture is preferably 1-20%.

[0848] z2) LC medium, wherein the LC host mixture contains one or more compounds selected from the group consisting of formulae CY and PY, one or more compounds selected from the group consisting of formulae AN and AY, and one or more compounds selected from the group consisting of formulae T and Q.

[0849] z3) LC medium, wherein the LC host mixture contains one or more, preferably 1, 2 or 3, compounds of the formula BF1, and one or more, preferably 1, 2 or 3, compounds selected from the group consisting of the formulae AY14, AY15 and AY16, very preferably the compound of the formula AY14. The proportion of the compounds of the formulae AY14-AY16 in the LC host mixture is preferably 2-35%, very preferably 3-30%. The proportion of the compounds of the formula BF1 in the LC host mixture is preferably 0.5-20%, very preferably 1-15%. Further preferably, the LC host mixture according to this preferred embodiment contains one or more, preferably 1, 2 or 3, compounds of the formula T, preferably selected from the group consisting of the formulae T1, T2 and T5, very preferably selected from the formulae T2 or T5. The proportion of the compound of the formula T in the LC host mixture is preferably 0.5-15%, very preferably 1-10%.

[0850] In a second preferred embodiment, the LC medium contains an LC host mixture based on compounds with positive dielectric anisotropy. Such LC media are particularly suitable for PS-OCB-, PS-TN-, PS-positive-VA-, PS-IPS- or PS-FFS-displays.

[0851]

[0852] where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings:

[0853] Each independently of the other and the same or different on each occurrence is

[0854]

[0855] R 21 , R 31 each independently of one another is 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,

[0856] X 0 is F, Cl, a haloalkyl or alkoxy radical having 1 to 6 C atoms, or a haloalkenyl or alkenyloxy radical having 2 to 6 C atoms,

[0857] Z 31 -CH 2 CH 2 -、-CF 2 CF 2 -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH 2 O- or single bond, preferably -CH 2 CH 2 -, -COO-, trans-CH=CH- or a single bond, particularly preferably -COO-, trans-CH=CH- or a single bond,

[0858] L 21 , L 22 , L 31 , L 32 Each independently represents H or F,

[0859] g is 0, 1, 2 or 3.

[0860] In the compounds of formula A and B, X 0 Preferably F, Cl, CF 3 , CHF 2 、OCF 3 , OCHF 2 ,OCFHCF 3 、OCFHCHF 2 、OCFHCHF 2 、OCF 2 CH 3 、OCF 2 CHF 2 、OCF 2 CHF 2 、OCF 2 CF 2 CHF 2 、OCF 2 CF 2 CHF 2 ,OCFHCF 2 CF 3 ,OCFHCF 2 CHF 2、OCF 2 CF 2 CF 3 、OCF 2 CF 2 CClF 2 ,OCClFCF 2 CF 3 or CH=CF 2 , F or OCF is very preferred 3 , F is most preferred.

[0861] In the compounds of formula A and B, R 21 and R 31 It is preferably selected from straight-chain alkyl or alkoxy radicals having 1, 2, 3, 4, 5 or 6 C atoms, and straight-chain alkenyl radicals having 2, 3, 4, 5, 6 or 7 C atoms.

[0862] In the compounds of formula A and B, g is preferably 1 or 2.

[0863] In the compound of formula B, Z 31 Preference is given to COO, trans-CH=CH or a single bond, and very preference is given to COO or a single bond.

[0864] Preferably, component B) of the LC medium comprises one or more compounds of formula A selected from the group consisting of:

[0865]

[0866]

[0867] Among them A 21 , A 22 , R 21 , X 0 , L 21 and L 22 has the meaning given in formula A, L 23 and L 24 are each independently H or F, and X 0 Preferred is F. Particularly preferred are compounds of the formulae A1 and A2.

[0868] Particularly preferred compounds of formula A1 are selected from the group consisting of the following subformulae:

[0869]

[0870]

[0871] Where R 21 , X 0 , L 21 and L 22has the meaning given in formula A1, L 23 , L 24 , L 25 and L 26 are each independently H or F, and X 0 F is preferred.

[0872] Very particularly preferred compounds of the formula A1 are selected from the group consisting of the following subformulae:

[0873]

[0874]

[0875] Where R 21 As defined in Formula A1.

[0876] Particularly preferred compounds of formula A2 are selected from the group consisting of the following subformulae:

[0877]

[0878]

[0879]

[0880] Where R 21 , X 0 , L 21 and L 22 has the meaning given in formula A2, L 23 , L 24 , L 25 and L 26 are each independently H or F, and X 0 Preferred is F.

[0881] Very particularly preferred compounds of the formula A2 are selected from the group consisting of the following subformulae:

[0882]

[0883]

[0884] Where R 21 and X 0 As defined in Formula A2.

[0885] Particularly preferred compounds of formula A3 are selected from the group consisting of the following subformulae:

[0886]

[0887] Where R 21 , X 0 , L 21and L 22 has the meaning given in formula A3, and X 0 Preferred is F.

[0888] Particularly preferred compounds of formula A4 are selected from the group consisting of the following subformulae:

[0889]

[0890] Where R 21 As defined in Formula A4.

[0891] Preferably, component B) of the LC medium comprises one or more compounds of formula B selected from the group consisting of:

[0892]

[0893]

[0894] Among them, g, A 31 , A 32 , R 31 , X 0 , L 31 and L 32 has the meaning given in formula B, and X 0 Preferred is F. Particularly preferred are compounds of the formulae B1 and B2.

[0895] Particularly preferred compounds of formula B1 are selected from the group consisting of the following subformulae:

[0896]

[0897] Where R 31 , X 0 , L 31 and L 32 has the meaning given in formula B1, and X 0 F is preferred.

[0898] Very particularly preferred compounds of the formula B1a are selected from the group consisting of the following subformulae:

[0899]

[0900]

[0901] Where R 31 As defined in Formula B1.

[0902] Very particularly preferred compounds of the formula B1b are selected from the group consisting of the following subformulae:

[0903]

[0904] Where R 31 As defined in Formula B1.

[0905] Particularly preferred compounds of formula B2 are selected from the group consisting of the following subformulae:

[0906]

[0907]

[0908] Where R 31 , X 0 , L 31 and L 32 has the meaning given in formula B2, L 33 , L 34 , L 35 and L 36 are each independently H or F, and X 0 Preferred is F.

[0909] Very particularly preferred compounds of the formula B2 are selected from the group consisting of the following subformulae:

[0910]

[0911]

[0912] Where R 31 As defined in Formula B2.

[0913] Very particularly preferred compounds of the formula B2b are selected from the group consisting of the following subformulae:

[0914]

[0915] Where R 31 As defined in Formula B2.

[0916] Very particularly preferred compounds of the formula B2c are selected from the group consisting of the following subformulae:

[0917]

[0918] Where R 31 As defined in Formula B2.

[0919] Very particularly preferred compounds of the formulae B2d and B2e are selected from the group consisting of the following subformulae:

[0920]

[0921] Where R 31 As defined in Formula B2.

[0922] Very particularly preferred compounds of the formula B2f are selected from the group consisting of the following subformulae:

[0923]

[0924] Where R 31 As defined in Formula B2.

[0925] Very particularly preferred compounds of the formula B2g are selected from the group consisting of the following subformulae:

[0926]

[0927]

[0928] Where R 31 As defined in Formula B2.

[0929] Very particularly preferred compounds of the formula B2h are selected from the group consisting of the following subformulae:

[0930]

[0931] Where R 31 As defined in Formula B2.

[0932] Very particularly preferred compounds of the formula B2i are selected from the group consisting of the following subformulae:

[0933]

[0934] Where R 31 As defined in Formula B2.

[0935] Very particularly preferred compounds of the formula B2k are selected from the group consisting of the following subformulae:

[0936]

[0937] Where R 31 As defined in Formula B2.

[0938] Very particularly preferred compounds of the formula B21 are selected from the group consisting of the following subformulae:

[0939]

[0940] Where R 31 As defined in Formula B2.

[0941] Alternatively or in addition to the compounds of the formulae B1 and / or B2, component B) of the LC medium may also comprise one or more compounds of the formula B3 as defined above.

[0942] Particularly preferred compounds of formula B3 are selected from the group consisting of the following subformulae:

[0943]

[0944] Where R 31 As defined in Formula B3.

[0945] Preferably, component B) of the LC medium comprises, in addition to compounds of the formula A and / or B, one or more compounds of the formula C:

[0946]

[0947] The various groups have the following meanings:

[0948] independently of each other, and

[0949] Each time it appears, it is the same or different

[0950]

[0951] R 41 , R 42 each independently of one another is 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,

[0952] Z 41 , Z 42 Each independently is -CH 2 CH 2 -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH 2 O-、-CF 2 O-, -C≡C- or a single bond, preferably a single bond,

[0953] h is 0, 1, 2 or 3.

[0954] In the compound of formula C, R 41 and R 42 It is preferably selected from straight-chain alkyl or alkoxy radicals having 1, 2, 3, 4, 5 or 6 C atoms, and straight-chain alkenyl radicals having 2, 3, 4, 5, 6 or 7 C atoms.

[0955] In the compounds of formula C, h is preferably 0, 1 or 2.

[0956] In the compound of formula C, Z 41 and Z 42 It is preferably selected from the group consisting of COO, trans-CH═CH and a single bond, very preferably selected from the group consisting of COO and a single bond.

[0957] Preferred compounds of formula C are selected from the group consisting of the following subformulae:

[0958]

[0959]

[0960] Where R 41 and R 42 has the meanings given in formula C and preferably each independently of one another represents alkyl, alkoxy, fluoroalkyl or fluoroalkoxy having 1 to 7 C atoms or alkenyl, alkenyloxy, alkoxyalkyl or fluoroalkenyl having 2 to 7 C atoms.

[0961] Preferably, component B) of the LC medium comprises, in addition to compounds of the formula A and / or B, one or more compounds of the formula D

[0962]

[0963] Among them A 41 , A 42 , Z 41 , Z 42 , R 41 , R 42 and h have the meanings given in formula C or one of the preferred meanings given above.

[0964] Preferred compounds of formula D are selected from the group consisting of the following subformulae:

[0965]

[0966] Where R 41 and R 42 has the meaning given in formula D and R 41 Preferably represents an alkyl group, and in formula D1 R 42 Preferably, it represents alkenyl, and particularly preferably, it represents -(CH 2 ) 2 -CH=CH-CH 3 , and in formula D2, R 42 Preferably, it represents an alkyl group, -(CH 2 ) 2 -CH=CH 2 or -(CH 2 ) 2 -CH=CH-CH 3 .

[0967] It is further preferred that component B) of the LC medium comprises, in addition to compounds of the formula A and / or B, one or more compounds of the formula E containing an alkenyl group

[0968]

[0969] where the individual radicals, identical or different on each occurrence, each independently of one another, have the following meanings:

[0970] express

[0971]

[0972] express

[0973]

[0974] R A1 is alkenyl having 2 to 9 C atoms, or, if at least one of the rings X, Y and Z represents cyclohexenyl, then R A1 Also has R A2 One of the meanings,

[0975] R A2 is an alkyl radical having 1 to 12 C atoms, wherein in addition one or two non-adjacent CH 2 The group may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to each other,

[0976] x is 1 or 2.

[0977] R A2 Preference is given to straight-chain alkyl or alkoxy radicals having 1 to 8 C atoms or straight-chain alkenyl radicals having 2 to 7 C atoms.

[0978] Preferred compounds of formula E are selected from the following sub-formulae:

[0979]

[0980]

[0981] Among them, alkyl and alkyl * each independently of one another represents a straight-chain alkyl radical having 1 to 6 C atoms, and alkenyl and alkenyl * each independently of one another represents a straight-chain alkenyl radical having 2 to 7 C atoms. * Preferably CH 2 =CH-, CH 2 =CHCH 2 CH 2 -、CH 3 -CH=CH-, CH3 -CH 2 -CH=CH-, CH 3 -(CH 2 ) 2 -CH=CH-, CH 3 -(CH 2 ) 3 -CH=CH- or CH 3 -CH=CH-(CH 2 ) 2 -.

[0982] Very preferred compounds of formula E are selected from the following sub-formulae:

[0983]

[0984] Where m represents 1, 2, 3, 4, 5 or 6, i represents 0, 1, 2 or 3, and R b1 Indicates H, CH 3 or C 2 H 5 .

[0985] Very particularly preferred compounds of the formula E are selected from the following sub-formulae:

[0986]

[0987] Most preferred are compounds of formula E1a2, E1a5, E3a1 and E6a1.

[0988] It is further preferred that component B) of the LC medium comprises, in addition to compounds of the formula A and / or B, one or more compounds of the formula F

[0989]

[0990] where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings:

[0991] express

[0992]

[0993] R 21 , R 31 each independently of one another is 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,

[0994] X 0 is F, Cl, a haloalkyl or alkoxy radical having 1 to 6 C atoms, or a haloalkenyl or alkenyloxy radical having 2 to 6 C atoms,

[0995] Z 21 -CH 2 CH 2 -、-CF 2 CF 2 -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH 2 O- or single bond, preferably -CH 2 CH 2 -, -COO-, trans-CH=CH- or a single bond, particularly preferably -COO-, trans-CH=CH- or a single bond,

[0996] L 21 , L 22 , L 23 , L 24 Each independently represents H or F,

[0997] g is 0, 1, 2 or 3.

[0998] Particularly preferred compounds of formula F are selected from the group consisting of:

[0999]

[1000]

[1001] Where R 21 , X 0 , L 21 and L 22 has the meaning given in formula F, L 25 and L 26 Each independently represents H or F, and X 0 Preferred is F.

[1002] Very particularly preferred compounds of the formulae F1 to F3 are selected from the group consisting of the following subformulae:

[1003]

[1004]

[1005] Where R 21 As defined in Formula F1.

[1006] The concentration of the compounds of formula A and B in the LC host mixture is preferably 2-60%, very preferably 3-45%, most preferably 4-35%.

[1007] The concentration of the compounds of formula C and D in the LC host mixture is preferably 2-70%, very preferably 5-65%, most preferably 10-60%.

[1008] The concentration of the compound of formula E in the LC host mixture is preferably 5-50%, very preferably 5-35%.

[1009] The concentration of the compound of formula F in the LC host mixture is preferably 2-30%, very preferably 5-20%.

[1010] Further preferred embodiments of this second preferred embodiment of the present invention are listed below, including any combination thereof.

[1011] 2a) The LC host mixture comprises one or more compounds of formula A and / or B having a positive dielectric anisotropy, preferably Δε>15.

[1012] 2b) The LC host mixture comprises one or more compounds selected from the group consisting of formulae A1a2, A1b1, A1d1, A1f1, A2a1, A2h1, A2l2, A2k1, B2h3, B2l1, F1a. The proportion of these compounds in the LC host mixture is preferably 4-40%, very preferably 5-35%.

[1013] 2c) The LC host mixture comprises one or more compounds selected from the group consisting of the formulae B2c1, B2c4, B2f4, C14. The proportion of these compounds in the LC host mixture is preferably 4-40%, very preferably 5-35%.

[1014] 2d) The LC host mixture comprises one or more compounds of the group consisting of the formulae C3, C4, C5, C9 and D2. The proportion of these compounds in the LC host mixture is preferably 8-70%, very preferably 10-60%.

[1015] 2e) The LC host mixture comprises one or more compounds selected from the group consisting of formulae E1, E3 and E6 (preferably E1a, E3a and E6a, very preferably E1a2, E1a5, E3a1 and E6a1). The proportion of these compounds in the LC host mixture is preferably 5-60%, very preferably 10-50%.

[1016] The combination of the compounds of the above-described preferred embodiments with the above-described polymerized compounds leads in the LC media according to the invention to low threshold voltages, low rotational viscosities and very good low-temperature stability, together with high clearing points and high HR values, and allows particularly low tilt angles (i.e. large tilts) to be established quickly in PSA displays. In particular, the LC media show significantly shortened response times, in particular also gray-to-gray response times, in PSA displays relative to the media of the prior art.

[1017] The LC media and LC host mixtures according to the invention preferably have a nematic phase range of at least 80 K, particularly preferably at least 100 K, and a rotational viscosity at 20° C. of ≤250 mPa·s, preferably ≤200 mPa·s.

[1018] In a VA-type display according to the invention, the molecules in the layer of the LC medium are aligned perpendicularly to the electrode surface (homeotropically) or have a tilted homeotropic alignment in the off state. When a voltage is applied to the electrodes, the LC molecules realign with their longitudinal molecular axes parallel to the electrode surface.

[1019] The LC media according to the invention, which are used in particular in PS-VA, PS-UB-FFS and SA-VA type displays and which, according to a first preferred embodiment, are based on compounds having a negative dielectric anisotropy, preferably have a negative dielectric anisotropy Δε at 20° C. and 1 kHz of from −0.5 to −10, in particular from −2.5 to −7.5.

[1020] The birefringence Δn of LC media according to the invention for use in displays of the PS-VA, PS-UB-FFS and SA-VA type is preferably below 0.16, particularly preferably from 0.06 to 0.14, very particularly preferably from 0.07 to 0.12.

[1021] In an OCB-type display according to the invention, the molecules in the layer of the LC medium have a "bend" alignment. Upon application of a voltage, a realignment of the LC molecules occurs with the longitudinal molecular axis perpendicular to the electrode surface.

[1022] The LC media according to the invention which are suitable for use in PS-TN, PS-positive-VA, PS-IPS or PS-FFS and SA-FFS type displays, which according to the second preferred embodiment are based on compounds with positive dielectric anisotropy, preferably have a positive dielectric anisotropy Δε of +2 to +30, particularly preferably +3 to +20 at 20° C. and 1 kHz.

[1023] The birefringence Δn of the LC media according to the invention for use in displays of the PS-OCB type is preferably from 0.14 to 0.22, particularly preferably from 0.16 to 0.22.

[1024] The birefringence Δn of the LC media according to the invention for use in displays of the PS-TN, PS-positive-VA, PS-IPS or PS-FFS and SA-FFS type is preferably from 0.07 to 0.15, particularly preferably from 0.08 to 0.13.

[1025] The LC media according to the invention may also contain further additives known to the person skilled in the art and described in the literature, such as polymerization initiators, inhibitors, stabilizers, surface-active substances or chiral dopants. These substances may be polymerizable or non-polymerizable. Polymerizable additives are therefore classified as polymerizable components or component A). Non-polymerizable additives are therefore classified as non-polymerizable components or component B).

[1026] Furthermore, it is possible to add, for example, 0 to 15% by weight of pleochroic dyes to the LC medium, in addition to nanoparticles, conductive salts, preferably ethyldimethyldodecyl 4-hexyloxyammonium benzoate, tetrabutylammonium tetraphenylborate or complex salts of crown ethers (see, for example, Haller et al., Mol. Cryst. Liq. Cryst. 24 , 249-258 (1973)) for improving the conductivity, or adding substances for changing the orientation, viscosity and / or dielectric anisotropy of the nematic phase. Such substances are described, for example, in DE-A 22 09127, 2240 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53728.

[1027] The individual components of the preferred embodiments a) to z) of the LC media according to the invention are known or the processes for preparing them can be derived from the prior art by the person skilled in the relevant art, since they are based on standard processes described in the literature. The corresponding compounds of the formula CY are described, for example, in EP-A-0 364 538. The corresponding compounds of the formula ZK are described, for example, in DE-A-26 36 684 and DE-A-33 21373.

[1028] The LC media which can be used according to 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. Usually, the desired amount of the component used in smaller amounts is dissolved in the component making up the main constituents, this being advantageously done at elevated temperature. It is also possible to mix the solutions of the components in an organic solvent, for example acetone, chloroform or methanol, and to remove the solvent again after thorough mixing, for example by distillation. The invention also relates to a process for the preparation of the LC media according to the invention.

[1029] It goes without saying to the person skilled in the art that the LC media according to the invention can also comprise compounds in which H, N, O, Cl, F are replaced by corresponding isotopes, for example deuterium.

[1030] The following examples explain the present invention without limiting it. However, they show preferred mixture concepts and preferably used compounds and their corresponding concentrations and their combinations with each other to those skilled in the art. In addition, the examples illustrate obtainable properties and property combinations.

[1031] Preferred mixture components are shown in Tables A1 and A2 below. The compounds shown in Table A1 are particularly suitable for use in LC mixtures with positive dielectric anisotropy. The compounds shown in Table A2 are particularly suitable for use in LC mixtures with negative dielectric anisotropy.

[1032] Table A1

[1033] In Table A1, m and n are independently an integer from 1 to 12, preferably 1, 2, 3, 4, 5 or 6, k is 0, 1, 2, 3, 4, 5 or 6, and (O)C m H 2m+1 Meaning C m H 2m+1 or OC m H 2m+1 .

[1034]

[1035]

[1036]

[1037]

[1038]

[1039]

[1040]

[1041]

[1042] Table A2

[1043] In Table A2, m and n are each independently an integer from 1 to 12, preferably 1, 2, 3, 4, 5 or 6, k is 0, 1, 2, 3, 4, 5 or 6, and (O)C m H 2m+1 Meaning C m H 2m+1 or OC m H 2m+1 .

[1044]

[1045] AIK-n-F

[1046]

[1047] AIY-n-Om

[1048]

[1049] AY-n-Om

[1050]

[1051] B-nO-Om

[1052]

[1053] B-n-Om

[1054]

[1055] B-nO-O5i

[1056]

[1057] B(S)-nO-Om

[1058]

[1059] CB-n-m

[1060]

[1061] CB-n-Om

[1062]

[1063] PB-n-m

[1064]

[1065] PB-n-Om

[1066]

[1067] BCH-nm,CPP-n-m

[1068]

[1069] BCH-nmF

[1070]

[1071] BCN-nm

[1072]

[1073] C-1V-V1

[1074]

[1075] CY-n-Om

[1076]

[1077] CY(F,Cl)-n-Om

[1078]

[1079] CY(Cl,F)-n-Om

[1080]

[1081] CCY-n-Om

[1082]

[1083] CCY(F,Cl)-n-Om

[1084]

[1085] CCY(Cl,F)-n-Om

[1086]

[1087] CCY-n-m

[1088]

[1089] CCY-V-m

[1090]

[1091] CCY-Vn-m

[1092]

[1093] CCY-n-OmV

[1094]

[1095] CBC-nmF

[1096]

[1097] CBC-nm

[1098]

[1099] CCP-V-m

[1100]

[1101] CCP-Vn-m

[1102]

[1103] CCP-nV-m

[1104]

[1105] CCP-n-m

[1106]

[1107] CPYP-n-(O)m

[1108]

[1109] CYYC-n-m

[1110]

[1111] CCYY-n-(O)m

[1112]

[1113] CCY-n-O2V

[1114]

[1115] CCH-nOm,CC-n-Om

[1116]

[1117] CCC-n-m

[1118]

[1119] CCC-n-V

[1120]

[1121] CY-n-m

[1122]

[1123] CCH-nm,CC-n-m

[1124]

[1125] CC-n-V

[1126]

[1127] CC-n-V1

[1128]

[1129] CC-n-Vm

[1130]

[1131] CC-V-V

[1132]

[1133] CC-V-V1

[1134]

[1135] CC-2V-V2

[1136]

[1137] CVC-n-m

[1138]

[1139] CC-n-mV

[1140]

[1141] CCOC-n-m

[1142]

[1143] CP-nOmFF

[1144]

[1145] CH-nm

[1146]

[1147] CEY-n-Om

[1148]

[1149] CEY-V-n

[1150]

[1151] CVY-V-n

[1152]

[1153] CY-V-On

[1154] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1155] <h2 style=";text-align:left;direction:ltr"> CY-n-O1V<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1156] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1157] <h2 style=";text-align:left;direction:ltr"> CY-n-OC(CH<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> )=CH<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1158] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1159] <h2 style=";text-align:left;direction:ltr"> CCN-nm<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1160] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1161] <h2 style=";text-align:left;direction:ltr"> CY-n-OV<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1162] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1163] <h2 style=";text-align:left;direction:ltr"> CCPC-nm<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1164] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1165] <h2 style=";text-align:left;direction:ltr"> CCY-n-kOm<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1166] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1167] <h2 style=";text-align:left;direction:ltr"> CPY-n-Om<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1168] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1169] <h2 style=";text-align:left;direction:ltr"> CPY-nm<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1170] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1171] <h2 style=";text-align:left;direction:ltr"> CPY-V-Om<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1172] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1173] <h2 style=";text-align:left;direction:ltr"> CQY-n-(O)m<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1174] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1175] <h2 style=";text-align:left;direction:ltr"> CQIY-n-(O)m<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1176] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1177] <h2 style=";text-align:left;direction:ltr"> CCQY-n-(O)m<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1178] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1179] <h2 style=";text-align:left;direction:ltr"> CCQIY-n-(O)m<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1180] <h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[1181] CPQY-n-(O)m

[1182]

[1183] CPQIY-n-(O)m

[1184]

[1185] CPYG-n-(O)m

[1186]

[1187] CCY-V-Om

[1188]

[1189] CCY-V2-(O)m

[1190]

[1191] CCY-1V2-(O)m

[1192]

[1193] CCY-3V-(O)m

[1194]

[1195] CCVC-n-V

[1196]

[1197] CCVC-V-V

[1198]

[1199] CPYG-n-(O)m

[1200]

[1201] CPGP-n-m

[1202]

[1203] CY-nV-(O)m

[1204]

[1205] CENaph-n-Om

[1206]

[1207] COChrom-n-Om

[1208]

[1209] COChrom-nm

[1210]

[1211] CCOchrome-n-Om

[1212]

[1213] CCOChrom-nm

[1214]

[1215] CONaph-n-Om

[1216]

[1217] CCONaph-n-Om

[1218]

[1219] CCNaph-n-Om

[1220]

[1221] CNaph-N-Om

[1222]

[1223] CETNaph-n-Om

[1224]

[1225] CTNaph-n-Om

[1226]

[1227] CK-nF

[1228]

[1229] CLY-n-Om

[1230]

[1231] CLY-nm

[1232]

[1233] LYLI-nm

[1234]

[1235] CYLI-n-m

[1236]

[1237] LY-n-(O)m

[1238]

[1239] COYOICC-n-m

[1240]

[1241] COYOIC-n-V

[1242]

[1243] CCOY-V-O2V

[1244]

[1245] CCOY-V-O3V

[1246]

[1247] COY-n-Om

[1248]

[1249] CCOY-n-Om

[1250]

[1251] D-nOmFF

[1252]

[1253] PCH-nm,CP-n-m

[1254]

[1255] PCH-nOm,CP-n-Om

[1256]

[1257] PGIGI-n-F

[1258]

[1259] PGP-n-m

[1260]

[1261] PP-nm

[1262]

[1263] PP-n-2V1

[1264]

[1265] PYP-n-mV

[1266]

[1267] PYP-nm

[1268]

[1269] PGIY-n-Om

[1270]

[1271] PYP-n-Om

[1272]

[1273] PPYY-nm

[1274]

[1275] PPGU-nF

[1276]

[1277] YPY-nm

[1278]

[1279] YPY-mV

[1280]

[1281] PY-n-Om

[1282]

[1283] PY-nm

[1284]

[1285] PY-V2-Om

[1286]

[1287] DFDBC-n(O)-(O)m

[1288]

[1289] Y-nO-Om

[1290]

[1291] Y-nO-OmV

[1292]

[1293] Y-nO-OkVm

[1294]

[1295] YG-n-Om

[1296]

[1297] YG-nO-Om

[1298]

[1299] YGI-n-Om

[1300]

[1301] YGI-nO-Om

[1302]

[1303] YY-n-Om

[1304]

[1305] YY-nO-Om

[1306] In a first preferred embodiment of the invention, the LC media according to the invention, especially those having positive dielectric anisotropy, comprise one or more compounds selected from the group consisting of the compounds from Table A1.

[1307] In a second preferred embodiment of the invention, the LC media according to the invention, especially those having a negative dielectric anisotropy, comprise one or more compounds selected from the group consisting of the compounds from Table A2.

[1308] Table B

[1309] Table B shows possible chiral dopants that can be added to the LC media according to the invention.

[1310]

[1311]

[1312] The LC medium preferably comprises 0 to 10% by weight, in particular 0.01 to 5% by weight, particularly preferably 0.1 to 3% by weight, of dopant. The LC medium preferably comprises one or more dopants selected from the group consisting of the compounds from Table B.

[1313] Table C

[1314] Table C shows possible stabilizers which can be added to the LC media according to the invention. wherein n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and no terminal methyl groups are shown.

[1315]

[1316]

[1317]

[1318]

[1319]

[1320]

[1321] The LC medium preferably comprises 0 to 10% by weight, in particular 1 ppm to 5% by weight, particularly preferably 1 ppm to 1% by weight, of stabilizers. The LC medium preferably comprises one or more stabilizers selected from the group consisting of compounds from Table C.

[1322] Table D

[1323] Table D shows illustrative reactive mesogenic compounds that can be used in the LC media according to the invention.

[1324]

[1325]

[1326]

[1327]

[1328]

[1329]

[1330]

[1331]

[1332]

[1333]

[1334]

[1335]

[1336]

[1337]

[1338]

[1339]

[1340]

[1341]

[1342]

[1343]

[1344]

[1345] In a preferred embodiment, the mixture according to the invention comprises one or more polymerizable compounds, which are preferably selected from the polymerizable compounds of formulae RM-1 to RM-144. Among these compounds, compounds RM-1, RM-4, RM-8, RM-17, RM-19, RM-35, RM-37, RM-39, RM-40, RM-41, RM-48, RM-52, RM-54, RM-57, RM-64, RM-74, RM-76, RM-88, RM-102, RM-103, RM-109, RM-117, RM-120, RM-121 and RM-122 are particularly preferred.

[1346] Table E

[1347] Table E shows self-aligning additives for homeotropic alignment which can be used together with the polymerisable compounds of formula I in the LC media according to the invention:

[1348]

[1349]

[1350]

[1351]

[1352]

[1353]

[1354]

[1355]

[1356]

[1357]

[1358]

[1359]

[1360] In a preferred embodiment, the LC media and displays according to the invention comprise one or more SA additives selected from the group consisting of formulae SA-1 to SA-48, preferably formulae SA-14 to SA-48, very preferably formulae SA-20 to SA-34 and SA-48, in combination with one or more RMs of formula I. Very preferred is the combination of polymerisable compounds 1, 2 or 3 of Example 1 hereinafter, very preferred is the polymerisable compound 3 of Example 1, in combination with an SA additive selected from the group consisting of formulae SA-20 to SA-34 and SA-44. Example

[1361] The following examples explain the present invention without limiting it. However, they show preferred mixture concepts and preferably used compounds and their corresponding concentrations and their combinations with each other to those skilled in the art. In addition, the examples illustrate obtainable properties and property combinations.

[1362] In addition, the following abbreviations and symbols are used:

[1363] V 0 represents the capacitive threshold voltage [V] at 20°C,

[1364] n e represents the extraordinary refractive index at 20°C and 589nm,

[1365] n o represents the ordinary refractive index at 20°C and 589nm,

[1366] Δn represents the optical anisotropy at 20°C and 589 nm,

[1367] ε ⊥ represents the dielectric constant perpendicular to the director at 20°C and 1kHz,

[1368] ε || represents the dielectric constant parallel to the director at 20°C and 1kHz,

[1369] Δε represents the dielectric anisotropy at 20°C and 1kHz,

[1370] cl.p., T(N,I) represents the clearing point [℃],

[1371] γ 1 represents the rotational viscosity at 20°C [mPa·s],

[1372] K 1 The elastic constant [pN] representing the "stretching" deformation at 20°C,

[1373] K 2 The elastic constant [pN] representing the "twist" deformation at 20°C,

[1374] K 3 This is the elastic constant [pN] that represents the "bending" deformation at 20°C.

[1375] Unless expressly stated otherwise, all concentrations in the present application are given as percentages by weight and relate to the respective entire mixture, which comprises all solid or liquid-crystalline components (without solvent).

[1376] Unless otherwise stated, all temperature values ​​indicated in this application, such as melting point T(C,N), transition from smectic phase (S) to nematic phase (N) T(S,N) and clearing point T(N,I) are expressed in degrees Celsius (°C). Mp stands for melting point, cl.p. = clearing point. In addition, C = liquid crystal phase, N = nematic phase, S = smectic phase and I = isotropic phase. The data between these symbols represent transition temperatures.

[1377] All physical properties are and have been determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals" Status November 1997, Merck KGaA, Germany, and are valid for a temperature of 20°C, with Δn measured at 589 nm and Δε measured at 1 kHz, unless expressly stated otherwise in each case.

[1378] The term "threshold voltage" as used in the present invention relates to the capacitive threshold (V 0 ), which is also referred to as the Freedericks threshold unless otherwise stated. In the embodiments, the optical threshold is also generally for a relative contrast ratio of 10% (V 10 ) given.

[1379] Unless otherwise stated, the process for polymerising the polymerisable compounds in a PSA display as described above and below is carried out at a temperature at which the LC medium exhibits a liquid crystal phase, preferably a nematic phase, and most preferably at room temperature.

[1380] Unless otherwise stated, the methods for preparing the test cells and measuring their electro-optical and other properties were performed by the methods described below or methods analogous thereto.

[1381] The display used to measure the capacitive threshold voltage consisted of two plane-parallel glass outer plates separated by 25 μm, each with an electrode layer on the inside and an unrubbed polyimide alignment layer on top, which resulted in homeotropic edge alignment of the liquid crystal molecules.

[1382] Unless otherwise stated, the PSVA display or PSVA test cell used to measure the tilt angle consists of two plane-parallel glass outer plates separated by 4 μm, each with an electrode layer on the inside and a polyimide alignment layer on the top, where the two polyimide layers are rubbed antiparallel to each other and cause homeotropic edge alignment of the liquid crystal molecules. The SAVA display or test cell has the same structure, but one or both of the polyimide layers are omitted.

[1383] The polymerizable compound is polymerized in the display or test box by irradiation with UV light of defined intensity for a predetermined time while applying voltage to the display (usually 10V to 30V AC, 1kHz). In the examples, unless otherwise stated, a metal halide lamp and 100mW / cm 2 The intensity of is used for polymerization. This intensity is measured using a standard meter (high-end Hoenle UV-meter with UV sensor).

[1384] The tilt angle is determined using a Mueller Matrix Polarimeter "AxoScan" from Axometrics. Low values ​​here (ie large deviations from an angle of 90°) correspond to large tilts.

[1385] Unless otherwise stated, the term "tilt angle" means the angle between the LC director and the substrate, and "LC director" means the preferred orientation direction of the optical principal axis of the LC molecules (corresponding to the molecular long axis thereof in the case of rod-shaped, uniaxial positively birefringent LC molecules) in a LC molecule layer having a uniform orientation.

[1386] Example

[1387] Mixture Example

[1388] H1: Nematic host mixture (Δε<0)

[1389]

[1390]

[1391] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H1.

[1392]

[1393] H2: Nematic host mixture (Δε<0)

[1394]

[1395]

[1396] A polymerizable mixture was prepared by adding 0.4% of reactive mesogen 1 to the nematic LC host mixture H2.

[1397] H3: Nematic host mixture (Δε<0)

[1398]

[1399] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H3.

[1400] H4: Nematic host mixture (Δε<0)

[1401]

[1402] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 2 and 100 ppm of stabilizer S1-1 to the nematic LC host mixture H4.

[1403]

[1404] H5: Nematic host mixture (Δε<0)

[1405]

[1406] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 3 to the nematic LC host mixture H5.

[1407]

[1408] H6: Nematic host mixture (Δε<0)

[1409]

[1410] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 4 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H6.

[1411]

[1412] H7: Nematic host mixture (Δε<0)

[1413]

[1414] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 1, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S2-1 to the nematic LC host mixture H7.

[1415]

[1416] H8: Nematic host mixture (Δε<0)

[1417]

[1418]

[1419] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 5 to the nematic LC host mixture H8.

[1420] H9: Nematic host mixture (Δε<0)

[1421]

[1422] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 5 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H9.

[1423]

[1424] H10: Nematic host mixture (Δε<0)

[1425]

[1426] A polymerizable mixture was prepared by adding 0.4% of reactive mesogen 5 and 100 ppm of stabilizer S3-1 to the nematic LC host mixture H10.

[1427]

[1428] H11: Nematic host mixture (Δε<0)

[1429]

[1430] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H11.

[1431] H12: Nematic host mixture (Δε<0)

[1432]

[1433] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 1 to the nematic LC host mixture H12.

[1434] H13: Nematic host mixture (Δε<0)

[1435]

[1436] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 3 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H13.

[1437] H14: Nematic host mixture (Δε<0)

[1438]

[1439] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H14.

[1440] H15: Nematic host mixture (Δε<0)

[1441]

[1442]

[1443] A polymerizable mixture was prepared by adding 0.4% of reactive mesogen 1 and 100 ppm of stabilizer S3-2 to the nematic LC host mixture H15.

[1444]

[1445] H16: Nematic host mixture (Δε<0)

[1446]

[1447] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H16.

[1448] H17: Nematic host mixture (Δε<0)

[1449]

[1450]

[1451] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 3 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H17.

[1452] A polymerizable mixture was prepared by adding 0.3% of prior art reactive mesogen C1 and 0.015% of stabilizer S1-1 to nematic LC host mixture H17. To this polymerizable mixture were added 0.9% of SA-additive SA-23, 0.4% of reactive mesogen 2 and 0.5% of reactive mesogen 6 to form a mixture according to the present invention.

[1453]

[1454] H18: Nematic host mixture (Δε<0)

[1455]

[1456] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 1 and 50 ppm of stabilizer S1-1 to the nematic LC host mixture H18.

[1457] H19: Nematic host mixture (Δε>0)

[1458]

[1459] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 1, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S3-3 to the nematic LC host mixture H19.

[1460]

[1461] H20: Nematic host mixture (Δε>0)

[1462]

[1463] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 2 and 100 ppm of stabilizer S1-1 to the nematic LC host mixture H20.

[1464] H21: Nematic host mixture (Δε>0)

[1465]

[1466] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S1-1 to the nematic LC host mixture H21.

[1467] H22: Nematic host mixture (Δε>0)

[1468]

[1469] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 3 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H22.

[1470] H23: Nematic host mixture (Δε>0)

[1471]

[1472]

[1473] A polymerizable mixture was prepared by adding 0.4% of reactive mesogen 2 to the nematic LC host mixture H23.

[1474] H24: Nematic host mixture (Δε>0)

[1475]

[1476] A polymerizable mixture was prepared by adding 0.6% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H24.

[1477] H25: Nematic host mixture (Δε<0)

[1478]

[1479]

[1480] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 1, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S2-1 to the nematic LC host mixture H25.

[1481] H26: Nematic host mixture (Δε<0)

[1482]

[1483] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H26.

[1484] H27: Nematic host mixture (Δε<0)

[1485]

[1486] H28: Nematic host mixture (Δε<0)

[1487]

[1488]

[1489] A polymerizable mixture was prepared by adding 0.4% of reactive mesogen 1 and 100 ppm of stabilizer S2-1 to the nematic LC host mixture H28.

[1490] H29: Nematic host mixture (Δε<0)

[1491]

[1492] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H29.

[1493] H30: Nematic host mixture (Δε<0)

[1494]

[1495] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 1 to the nematic LC host mixture H30.

[1496] H31: Nematic host mixture (Δε<0)

[1497]

[1498] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S2-1 to the nematic LC host mixture H31.

[1499] H32: Nematic host mixture (Δε<0)

[1500]

[1501] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H32.

[1502] H33: Nematic host mixture (Δε<0)

[1503]

[1504]

[1505] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H33.

[1506] H34: Nematic host mixture (Δε<0)

[1507]

[1508] A polymerizable mixture was prepared by adding 0.6% of reactive mesogen 3 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H34.

[1509] H35: Nematic host mixture (Δε<0)

[1510]

[1511]

[1512] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 3 and 100 ppm of stabilizer S1-1 to the nematic LC host mixture H35.

[1513] H36: Nematic host mixture (Δε<0)

[1514]

[1515] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 1 and 100 ppm of stabilizer S1-1 to the nematic LC host mixture H36.

[1516] H37: Nematic host mixture (Δε<0)

[1517]

[1518] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 2, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S3-1 to the nematic LC host mixture H37.

[1519] H38: Nematic host mixture (Δε<0)

[1520]

[1521] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H38.

[1522] H39: Nematic host mixture (Δε<0)

[1523]

[1524]

[1525] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H39.

[1526] H40: Nematic host mixture (Δε<0)

[1527]

[1528] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H40.

[1529] H41: Nematic host mixture (Δε<0)

[1530]

[1531] A polymerizable mixture was prepared by adding 0.3% of reactive mesogen 1 and 100 ppm of stabilizer S1-1 to the nematic LC host mixture H41.

[1532] H42: Nematic host mixture (Δε<0)

[1533]

[1534] A polymerizable mixture was prepared by adding 1.0% of reactive mesogen 3, 0.6% of SA-additive SA-23 and 50 ppm of stabilizer S3-2 to the nematic LC host mixture H42.

[1535] H43: Nematic host mixture (Δε<0)

[1536]

[1537] A polymerizable mixture was prepared by adding 0.6% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H43.

[1538] H44: Nematic host mixture (Δε<0)

[1539]

[1540]

[1541] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H44.

[1542] H45: Nematic host mixture (Δε<0)

[1543]

[1544] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H45.

[1545] H46: Nematic host mixture (Δε<0)

[1546]

[1547]

[1548] A polymerizable mixture was prepared by adding 0.6% of reactive mesogen 2 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H46.

[1549] H47: Nematic host mixture (Δε<0)

[1550]

[1551] A polymerizable mixture was prepared by adding 0.5% of reactive mesogen 1 and 0.6% of SA-additive SA-23 to the nematic LC host mixture H47.

[1552] Application Examples

[1553] Application Example A

[1554] A1) Main mixture

[1555] H48: Nematic host mixture (Δε<0)

[1556]

[1557]

[1558] A2) polymerizable mixture P11-P15, PC11

[1559] Polymerizable mixtures P11-P15 were prepared by adding one of the reactive mesogens 1-3 at different concentrations to the nematic LC host mixture H48 and further adding the SA-additive SA-23.

[1560] For comparative purposes, a polymerizable mixture PC11 was prepared by adding prior art reactive mesogen C1 and SA-additive SA-23 to the nematic LC host mixture H48.

[1561]

[1562]

[1563] Table 1 shows the composition of each polymerizable mixture.

[1564] Table 1 - Composition of polymerizable mixtures

[1565] Mixture No. PC11 P11 P12 P13 P14 P15 LC body H48 H48 H48 H48 H48 H48 RM C1 1 1 2 2 3 RM wt.% 0.3％ 0.5％ 1.0％ 0.5％ 1.0％ 0.5％ SA-23wt.% 0.6％ 0.6％ 0.6％ 0.6％ 0.6％ 0.6％

[1566] A3) Test Box

[1567] Each polymerizable mixture in Table 1 was filled into a SA-VA test cell, and the polymerizable compound was photopolymerized by UV exposure under application of a voltage of 0 V.

[1568] The test box used was a SA-VA resin BM box without PI. Afterwards, the test box was irradiated with UV light in two steps:

[1569] UV1: 100mW / cm 2 UV irradiation (using nm sensor measurement). Lamp Type: MH lamp UV-A Cube 2000. Cut-off filter 320nm. Applied voltage 0V. Temperature 40℃. Irradiation time 2 minutes.

[1570] UV2: C-type fluorescent UV lamp, room temperature, 120 minutes.

[1571] The total reflectance averaged over a wavelength range of 400 nm to 700 nm of each polymerized mixture after UV exposure was measured using a spectrophotometer CM-700d (Konica Minolta).

[1572] Table 2 – Reflectivity

[1573]

[1574]

[1575] It can be seen that the polymerizable LC media P11 to P15 according to the invention comprising reactive mesogens 1, 2 or 3 of formula I show a reduced reflectivity compared to the polymerizable LC medium PC11 comprising reactive mesogen C1 according to the prior art.

[1576] The polymerisable LC media P11 - P15 are therefore particularly suitable for use in polymer-stabilised SA-VA displays.

[1577] Application Example B

[1578] B1) Main mixture

[1579] H49: Nematic host mixture (Δε<0)

[1580]

[1581] B2) polymerizable mixtures P22, P23, PC21

[1582] Polymerizable mixtures P22 and P23 according to the invention were prepared by adding reactive mesogens 2 or 3, respectively, to the nematic LC host mixture H49.

[1583] For comparative purposes, a polymerizable mixture PC21 was prepared by adding the prior art reactive mesogen C1 to the nematic LC host mixture H49.

[1584] Table 3 shows the composition of each polymerizable mixture.

[1585] Table 3 - Composition of polymerizable mixtures

[1586] Mixture No. PC21 P22 P23 LC body H49 H49 H49 RM C1 2 3 RM wt.% 0.3％ 0.3％ 0.3％

[1587] B3) Test box

[1588] Each polymerizable mixture in Table 3 was filled into a test cell, RM was photopolymerized by UV exposure under applied voltage to cause generation of a tilt angle, and characteristics such as VHR before and after UV stress, generation of a tilt angle, and residual RM content were measured.

[1589] VHR

[1590] The VHR of the polymerizable LC medium was measured at 100°C by applying a voltage of 1 V / 60 Hz before and after UV illumination. The sunlight test was performed at 20°C using a light intensity of 765 W / m 2 The 2h lighting composition of the xenon lamp type Atlas Suntest CPS+.

[1591] Light stress usually leads to a decrease in VHR in LC blends, so the smaller the absolute decrease in VHR value after stress, the better the performance for display applications. The results are shown in Table 4.

[1592] Table 4 - VHR

[1593]

[1594] As can be seen in Table 4, the polymerisable LC media P22 and P23 according to the invention comprising reactive mesogens 2 or 3 of formula I have higher VHR values ​​than the polymerisable LC medium PC21 comprising reactive mesogen C1 according to the prior art.

[1595] Tilt Angle

[1596] UV photopolymerization was performed by using a 320 nm long pass filter and 100 mW / cm 2 The light intensity was measured under a metal halide lamp (UCcube 2000). The test boxes were allowed to relax for at least 12 hours before calculating the final tilt angle.

[1597] The results are shown in Table 5.

[1598] Table 5 - Tilt Angle

[1599]

[1600] It can be seen that the tilt angle produced in the mixture with reactive mesogens 2 and 3 is comparable to or smaller than the tilt angle in the mixture with reactive mesogen C1.

[1601] As can be seen in Table 5, the tilt angles produced in the polymerisable LC media P22 and P23 according to the invention comprising reactive mesogens 2 or 3 of formula I are comparable to or smaller (meaning stronger tilt) than the tilt angle produced in the polymerisable LC medium PC21 comprising reactive mesogen C1 according to the prior art.

[1602] Residual RM

[1603] After UV photopolymerization, the residual content of unpolymerized RM in the mixture is determined (in % by weight). After a given time interval, the smaller the residual RM content, the faster the polymerization reaction. For this purpose, the polymerizable mixture is filled into a test box and polymerized as described above. After photopolymerization, the test box is opened, the mixture is dissolved and rinsed out of the test box with 2 ml of ethyl methyl ketone and analyzed by high performance liquid chromatography (HPLC).

[1604] The results are shown in Table 6.

[1605] Table 6 - Residual RM

[1606]

[1607] As can be seen from Table 6, the polymerisation reaction in the polymerisable LC media P22 and P23 according to the invention comprising reactive mesogens 2 or 3 of formula I is faster and more complete with a lower residual monomer content than in the polymerisable LC medium PC21 comprising reactive mesogen C1 according to the prior art.

[1608] Therefore, the polymerizable LC media P22 and P23 are particularly suitable for use in PS-VA displays.

[1609] Application Example C

[1610] C1) Polymerizable mixture P16-P110

[1611] Polymerizable mixtures P16-P110 were prepared by adding various combinations of reactive mesogens 1-3 at different concentrations to the nematic LC host mixture H48 and further adding the SA-additive SA-23.

[1612] Table 7 - Composition of polymerizable mixture

[1613]

[1614]

[1615] C2) Test box

[1616] Each polymerizable mixture in Table 7 was filled into a PI-free SA-VA resin BM cell. The RM and additives were photopolymerized by UV exposure as described in Example 1. The reflectivity of the cell was measured after UV exposure and is shown in Table 8.

[1617] Table 8 – Reflectivity

[1618] Mixture No. PC11 P16 P17 P18 P19 P110 Reflectivity after UV 11.1 10.4 10.2 9.6 9.6 10.0

[1619] It can be seen that the polymerizable LC media P16 to P110 according to the invention comprising at least one reactive mesogen 1, 2 or 3 of formula I show a significantly lower reflectivity after UV exposure than the polymerizable LC medium PC11 comprising only reactive mesogen C1 according to the prior art.

[1620] The polymerisable LC media P16-P110 are therefore particularly suitable for use in polymer-stabilised SA-VA displays.

[1621] Application Example D

[1622] D1) polymerizable mixture P111, P112

[1623] Polymerizable mixtures P111 and P112 were prepared by adding various combinations of reactive mesogens C1, 2 and 4 at different concentrations to the nematic LC host mixture H48 and further adding the SA-additive SA-23.

[1624]

[1625] Table 9 - Composition of polymerizable mixture

[1626]

[1627] Each polymerizable mixture in Table 9 was filled into a SA-VA resin BM cell without PI. The RM and additives were photopolymerized by UV exposure as described in Example 1. The reflectivity of the cell was measured after UV exposure and is shown in Table 10.

[1628] Table 10 – Reflectivity

[1629] Mixture No. PC11 P111 P112 Reflectivity after UV 11.1 10.3 9.8

[1630] It can be seen that the polymerizable LC media P111-P112 according to the invention comprising various combinations of reactive mesogens 2, 4 of formula I show significantly lower reflectivity after UV exposure compared to the polymerizable LC medium PC11 comprising only reactive mesogen C1 according to the prior art.

Claims

1. LC medium comprising: - a polymerizable component A) comprising one or more polymerizable compounds, at least one of which is a compound of formula I, selected from the following formulae I2A-1 to I5D-5, - a liquid crystal component B), also called "LC host mixture", which comprises one or more mesogenic or liquid crystal compounds, - optionally one or more additives selected from self-aligning additives and stabilizers for vertical alignment of formula II, in P is selected from vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxy, Sp represents a spacer group or a single bond optionally substituted by P, Sp(P)2 represents a spacer group Sp substituted by two polymerizable groups P at the same or different positions, A represents an alkenyl group having 2 to 7 C atoms, L represents F, Cl, -CN, P-Sp- or a straight-chain, branched or cyclic alkyl group having 1 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that the O and / or S atoms are not directly connected to one another, and wherein one or more H atoms are optionally replaced by P-Sp-, F or Cl, MES-R a II MES denotes a rod-shaped mesogenic group comprising two or more rings which are directly or indirectly connected to one another or fused to one another, said rings being optionally substituted, and wherein the mesogenic group is optionally additionally substituted by one or more polymerizable groups which are directly connected to the MES or via a spacer, and R a denotes a polar anchoring group which is located in the terminal position of the rod-shaped mesogenic group MES, which comprises at least one carbon atom and at least one group selected from -OH, -SH, -COOH, -CHO or a primary or secondary amine functional group, and which optionally comprises one or two polymerizable groups P.

2. LC medium according to claim 1, characterized in that A in the compound of formula I is -CH=CH2, -CH2-CH=CH2, -CH=CH-CH3, -CH=CH-CH=CH2 or -C(CH3)=CH2.

3. LC medium according to claim 1 or 2, characterized in that When Sp in the compound of formula I is different from a single bond, it is selected from -(CH2) p1 -、-O-(CH2) p1 -、-O-CO-(CH2) p1 or -CO-O-(CH2) p1 , wherein p1 is 2, 3, 4, 5 or 6, and if Sp is -O-(CH2) p1 -、-O-CO-(CH2) p1 or -CO-O-(CH2) p1 , then the O-atom or CO-group, respectively, is attached to the benzene ring.

4. LC medium according to claim 1, characterized in that It comprises one or more self-aligning additives of formula II selected from formula IIa R 21 -[A 22 -Z 22 ] m2 -A 22 -R a IIa in A 22 each independently of one another represents an aromatic, heteroaromatic, alicyclic or heterocyclic radical which may also contain fused rings and which may also be replaced by a radical L 12 or -Sp-P is singly or polysubstituted, L 12 represents, in each case independently of one another, F, Cl, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R 0 )2, -C(=O)R 0 , optionally substituted silyl, optionally substituted aryl or cycloalkyl having 3 to 20 C atoms or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having up to 25 C atoms, where in addition one or more H atoms may each be replaced by F or Cl, P represents a polymerizable group, Sp represents a spacer group or a single bond, Z 22 represents, independently of one another, a single bond, -O-, -S-, -CO-, -CO-O-, -OCO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -C≡C-, -CH=CH-COO-, -OCO-CH=CH-, -(CR 0 R 00 ) n1 -, -CH(-Sp-P)-, -CH2CH-(-Sp-P)- or -CH(-Sp-P)CH(-Sp-P)-, n1 means 1, 2, 3 or 4, m2 means 1, 2, 3, 4, 5 or 6, R 0 represents in each case independently of one another an alkyl radical having 1 to 12 C atoms, R 00 in each case independently of one another represents H or alkyl having 1 to 12 C atoms, R 21 independently of one another denotes H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein in addition, one or more non-adjacent CH2 groups may each be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO- or -O-CO-O- in such a way that the O and / or S atoms are not directly connected to one another, and wherein in addition, one or more H atoms may each be replaced by F or Cl, or a P-Sp-group, and R a represents a polar anchoring group, further defined as having at least one selected from -OH, -NH2, -NHR 22 , C(O)OH and -CHO groups, where R 22 represents an alkyl group having 1 to 12 C atoms.

5. LC medium according to claim 4, characterized in that In the compounds of formula II and IIa, the polar anchoring group R a Select from the following formula in p means 1 or 2, q means 2 or 3, B represents a substituted or unsubstituted ring system or a condensed ring system, Y, identically or differently on each occurrence, represents -O-, -S-, -C(O)-, -C(O)O-, -OC(O-) or a single bond, o means 0 or 1, X 1 represents, identically or differently on each occurrence, H, alkyl, fluorinated alkyl, OH, NH2, NHR 22 , NR 22 2.OR 22 , C(O)OH, or -CHO, wherein at least one group X 1 represents a compound selected from -OH, -NH2, -NHR 22 , C(O)OH, and -CHO groups, R 22 represents an alkyl group having 1 to 12 C atoms, Sp a , Sp c , Sp d each independently of one another represents a spacer group or a single bond, and Sp b represents a tri- or tetravalent group.

6. LC medium according to claim 1 or 2, characterized in that The self-aligning additive for vertical alignment comprises one or more polymerizable groups P-Sp-.

7. LC medium according to claim 1, characterized in that The self-aligning additive for vertical alignment is selected from the following formula Where R 21 , R a , A 22 , Z 22 , Sp, P and L 12 has the meaning given to it in claim 4, m2 is independently 1, 2 or 3, and r1 is independently 0, 1, 2, 3, or 4.

8. LC medium according to claim 4 or 7, characterized in that In formula II, IIa and II-A to II-B, the polar anchoring group R a Select from the following formula in p is 1, 2, 3, 4, 5 or 6, x is 1 or 0, and R 23 is H, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl or -CH2CH2-tert-butyl.

9. LC medium according to claim 1 or 2, characterized in that It comprises one or more compounds of formula CY and / or PY: The various groups have the following meanings: a means 1 or 2, b represents 0 or 1, express R 1 and R 2 each independently of one another represents an alkyl group having 1 to 12 C atoms, wherein, in addition, one or two non-adjacent CH2 groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -CO-O- in such a way that the O atoms are not directly connected to one another, Z x represents -CH=CH-, -CH2O-, -OCH2-, -CF2O-, -OCF2-, -O-, -CH2-, -CH2CH2- or a single bond, L 1-4 Each independently represents F, Cl, OCF3, CF3, CH3, CH2F, CHF2.

10. LC medium according to claim 1 or 2, characterized in that It contains one or more compounds selected from the following formulae: where the individual radicals have the following meanings on each occurrence, identically or differently and independently of one another: express express express R A1 is alkenyl having 2 to 9 C atoms, or, if at least one of the rings X, Y and Z represents cyclohexenyl, then R A1 Also has R A2 One of the meanings of R A2 is an alkyl radical having 1 to 12 C atoms, wherein furthermore one or two non-adjacent CH2 groups may be replaced by -O-, -CH=CH-, -CO-, -OCO- or -COO- in such a way that the O atoms are not directly connected to one another, Z x is -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CO-O-, -O-CO-, -C2F4-, -CF=CF-, -CH=CH-CH2O- or a single bond, L 1-4 each independently of the other is H, F, Cl, OCF3, CF3, CH3, CH2F or CHF2H, x is 1 or 2, z is 0 or 1.

11. LC medium according to claim 1 or 2, characterized in that It contains one or more compounds of the following formula: The various groups have the following meanings: express express R 3 and R 4 each independently of one another represents an alkyl radical having 1 to 12 C atoms, furthermore one or two non-adjacent CH2 groups may be replaced by -O-, -CH=CH-, -CO-, -O-CO- or -CO-O- in such a way that the O atoms are not directly connected to one another, Z y It represents -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF or a single bond.

12. LC medium according to claim 1 or 2, characterized in that It contains one or more stabilizers selected from the following formula where the individual radicals, independently of one another and identically or differently on each occurrence, have the following meanings: R a-d is a straight-chain or branched alkyl radical having 1 to 10 C atoms, X S H, CH3, OH or O ● , A S is a linear, branched or cyclic alkylene radical having 1 to 20 C atoms, which is optionally substituted, n is an integer of 1 to 6.

13. LC medium according to claim 1 or 2, characterized in that The polymerizable compounds of formulae I and II are polymerized.

14. Process for preparing an LC medium according to any of claims 1 to 13, comprising the steps of mixing one or more mesogenic or liquid-crystalline compounds or liquid-crystalline component B) as defined in claim 1 with one or more compounds of formula I as defined in any of claims 1 to 8 and optionally one or more compounds of formula II, and optionally with further liquid-crystalline compounds and / or additives, and optionally polymerizing polymerizable compounds of formulae I and II.

15. LC display comprising an LC medium according to any one of claims 1 to 13.

16. LC display as claimed in claim 15 which is a PSA or a polymer-stabilised SA display.

17. LC display as claimed in claim 16 which is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-positive-VA, PS-TN, a polymer-stabilised SA-VA display or a polymer-stabilised SA-FFS display.

18. An LC display as claimed in claim 16 or 17, characterised in that It comprises two substrates, at least one of which is transparent to light, electrodes provided on each substrate or two electrodes provided on only one of the substrates, and a layer of an LC medium according to any of claims 1 to 13 located between the substrates, wherein the polymerizable compound between the substrates of the display is polymerized.

19. A method of manufacturing an LC display according to claim 18, comprising the steps of: An LC medium according to any one of claims 1 to 13 is provided between substrates of a display, and the polymerisable compound is polymerised.

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