Liquid-crystalline medium

Abstract

The present application relates to a liquid-crystalline (LC) medium as defined in claim 1 comprising a compound of formula I and one or more compounds selected from the group consisting of compounds of formulae IIA, IIB, IIC and IID, and to its use for optical, electro-optical and electronic purposes, in particular in LC displays, especially in IPS, FFS, VA or PS-VA displays.

Description

TECHNICAL FIELD

[0001] The present application relates to liquid-crystalline (LC) media and to the use thereof for optical, electro-optical and electronic purposes, in particular for LC displays, especially for use in IPS, FFS, VA or PS-VA displays. BACKGROUND

[0002] One mode of liquid-crystal displays (LCD) currently in use is the TN ("twisted nematic") mode. However, TN LCDs have the disadvantage that the contrast has a strong dependence on the viewing angle.

[0003] In addition, so-called VA (vertically aligned) displays with a wider viewing angle are known. The LC cell of a VA display contains a layer of LC medium between two transparent electrodes, where the LC medium usually has a negative dielectric anisotropy. In the unenergized 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 re-alignment of the LC molecules parallel to the electrode surfaces takes place.

[0004] In addition, OCB ("optically compensated birefringence") displays are known, which are based on the birefringence effect and have an LC layer with a so-called "bend" alignment and usually a positive dielectric anisotropy. Upon application of a voltage, a re-alignment of the LC molecules perpendicular to the electrode surfaces takes place. In addition, OCB displays usually contain one or more birefringent optical retardation films to prevent an undesired light transmission of the bend cell in the dark state. OCB displays have a wider viewing angle and a shorter response time than TN displays.

[0005] Also known are so-called IPS ("in-plane switching") displays, which contain an LC layer between two substrates, where both electrodes are only arranged on one of the two substrates and have a comb structure which engages with one another. Upon application of a voltage to the electrodes, an electric field is thus generated between them which has a significant component parallel to the LC layer. This leads to a re-alignment of the LC molecules in the layer plane.

[0006] In addition, so-called FFS (fringe field switching) displays have been reported (see, inter alia, S. H. Jung et al., Jpn. J. Appl. Phys., Vol. 43, No. 3, 2004, 1028) which contain two electrodes on the same substrate, one of which is structured in a comb-like fashion and the other is unstructured. Thereby a strong so-called "fringe field" is generated, i.e. a strong electric field close to the edges of the electrodes, and such electric fields in the whole cell which have both a strong vertical component as well as a strong horizontal component. FFS displays have a small contrast viewing angle dependence. FFS displays usually contain an LC medium having a positive dielectric anisotropy, and an alignment layer, usually a polyimide alignment layer, which provides a planar alignment of the molecules of the LC medium.

[0007] FFS displays can be operated as active matrix or passive matrix displays. In the case of active matrix displays, the individual pixels are usually addressed by means of integrated non-linear active elements such as transistors (e.g. thin film transistors or "TFTs"), whereas in the case of passive matrix displays, the individual pixels are usually addressed according to multiplexing methods as known in the art.

[0008] Furthermore, FFS displays have been disclosed (cf. S. H. Lee et al., Appl. Phys. Lett. 73 (20), 1998, 2882-2883 and S. H. Lee et al., Liquid Crystals 39 (9), 2012, 1141-1148) which have a similar electrode design and layer thickness as FFS displays, but comprise 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 favourable director orientation compared to LC media having a positive dielectric anisotropy with less tilt and more twisted orientation, which results in these displays having a higher transmission. The displays further comprise an alignment layer, preferably a polyimide provided on at least one of the substrates, which is in contact with 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 LC media having a high reliability.

[0009] The term "reliability" as used in the following means the quality of the performance of the display over time and under different stress loads, such as light load, temperature, humidity, voltage, and includes display effects such as image sticking (both area and line image sticking), mura, yogore, etc., which are known to the person skilled in the art of LC displays. As a standard parameter for classifying the 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 the LC medium.

[0010] In the newer type of VA displays, the uniform alignment of the LC molecules is limited to a plurality of relatively small domains within the LC cell. Between these domains disclinations, also called tilt domains, can exist. VA displays with tilt domains have a greater viewing angle independence of contrast and grey shade than conventional VA displays. In addition, this type of display is easier to produce, since the additional electrode surface treatment (e.g. by rubbing) for aligning the molecules uniformly in the on state is no longer required. Instead, the preferential direction of the tilt or pretilt angle is controlled by a special design of the electrodes.

[0011] In so-called MVA (multi-domain vertical alignment) displays, this is usually achieved by electrodes with protrusions which lead to a local pretilt. Thereby, the LC molecules are aligned parallel to the electrode surface in different, defined cell regions in different directions upon application of a voltage. A "controlled" switching is thereby achieved and the formation of disturbing disclination lines is prevented. Although this arrangement improves the viewing angle of the display, it leads to a reduction in its light transmission. A further improvement of MVA uses protrusions on only one electrode side, while the opposite electrode has slits, which improve the light transmission. The slit electrode generates a non-uniform electric field in the LC cell upon application of a voltage, meaning that a controlled switching is still achieved. To further improve the light transmission, the spacing between the slits and the protrusions can be enlarged, but this in turn leads to a prolongation of the response time. In so-called PVA ("patterned VA"), the protrusions are made completely superfluous, since both electrodes are structured by slits on the opposite side, which leads to an increased contrast and an 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 as well as to improve the contrast and the brightness (transmission) of the display.

[0012] Another development is the so-called PS ("polymer stabilized") or PSA ("polymer stabilized alignment") display, to which occasionally also the term "polymer stabilization" is applied. In these, a small amount (e.g. 0.3 wt.-%, typically < 1 wt.-%) of one or more polymerizable compounds, preferably polymerizable monomeric compounds, is added to the LC medium and polymerized or cross-linked in situ (usually by UV photopolymerization) after the LC medium has been filled into the display, while optionally applying a voltage to the electrodes of the display. The polymerization is carried out at temperatures at which the LC medium shows a liquid-crystalline phase, typically at room temperature. It has proven particularly suitable to add polymerizable mesogenic or liquid-crystalline compounds (also referred to as reactive mesogens or "RMs") to the LC mixture.

[0013] Unless indicated otherwise, the term "PSA" is used hereinafter when referring to displays of the general polymer stabilized alignment type, and "PS" when referring to specific display modes (such as PS-VA, PS-TN etc.).

[0014] Furthermore, unless indicated otherwise, the term "RM" is used hereinafter when referring to polymerizable mesogenic or liquid-crystalline compounds.

[0015] At the same time, the PS(A) principle is being used for 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, in the case of PS-VA and PS-OCB displays, preferably takes place under an applied voltage, in the case of PS-IPS displays with or without, preferably without, an applied voltage. The PS(A) process leads to a pre-tilt in the cell, as can be verified in test cells. In the case of PS-OCB displays, for example, it can be that the bend structure is stabilized, so that the disclination voltage is not required or can be reduced. In the case of PS-VA displays, the pre-tilt has a positive effect on the response time. For PS-VA displays, standard MVA or PVA pixels and electrode layouts can be used. However, it is also possible, for example, to manage with only one structured electrode side without protrusions, which significantly simplifies production and at the same time leads to very good contrast and very good light transmission.

[0016] Furthermore, so-called positive-VA displays ("positive VA") have proven to be a particularly advantageous mode. Similar to conventional VA displays, in a positive-VA display the initial alignment of the LC molecules in the initial state when no voltage is applied is homeotropic, i.e. substantially perpendicular to the substrates. However, in contrast to conventional VA displays, in a positive-VA display an LC medium having a positive dielectric anisotropy is used. Similar to in the commonly used IPS displays, in a positive-VA display the two electrodes are arranged only on one of the two substrates and exhibit a structure which preferably intermeshes and is comb-like (interdigital). By applying a voltage to the interdigital electrodes which generates an electric field which is substantially parallel to the LC medium layer, the LC molecules are converted into an alignment which is substantially parallel to the substrates. In a positive-VA display, polymer stabilisation (by adding a RM which polymerises in the display to the liquid-crystalline medium) has also proven to be advantageous, whereby a significant shortening of the response times can be achieved.

[0017] 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 S. H. 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.

[0018] Under the layer formed by the phase separation and the polymerisation of the RM which induces the above-mentioned pretilt angle, PSA displays typically contain an alignment layer, for example an alignment layer of polyimide, which provides the initial alignment of the LC molecules before the polymer stabilisation step.

[0019] Frictioned polyimide layers have long been used as alignment layers. The friction method causes a number of problems, such as colour shading, contamination, electrostatic discharge problems, residues, etc. Therefore, instead of frictioned polyimide layers, the use of polyimide layers prepared by photoalignment, using the photoinduced directional order of the alignment surface, is proposed. This can be achieved by means of polarised light, via photodecomposition, photodimerisation or photoisomerisation.

[0020] However, there is still a need for suitably derivatized polyimide layers comprising photoreactive groups. Generally, the effort and costs for producing such polyimide layers, treating the polyimide and modifying the bump or polymer layer are relatively large.

[0021] In addition, it was observed that an adverse interaction of the polyimide alignment layer with certain compounds of the LC medium generally leads to a reduction of the electrical resistance of the display. The number of suitable and usable LC compounds is thus significantly reduced at the expense of display parameters (such as viewing angle dependence, contrast and response time) which are intended to be improved by using such LC compounds. There is thus a need to omit the polyimide alignment layer.

[0022] For some display modes, this is achieved by adding a self-alignment agent or additive to the LC medium which induces the desired alignment, e.g. homeotropic or planar alignment, in situ by a self-assembly mechanism. Thus, an alignment layer on one or both substrates can be omitted. These display modes are also referred to as "self-alignment" or "self-aligned" (SA) modes.

[0023] In SA displays, a small amount (typically 0.1 to 2.5%) of a self-alignment additive is added to the LC medium. Suitable self-alignment 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 aligns and also induces the desired alignment in the LC molecules. Preferred self-alignment additives comprise, for example, a mesogenic group and straight-chain or branched alkyl side chains terminated by one or more polar anchoring groups, for example selected from hydroxyl, carboxyl, amino or thiol groups. The self-alignment additive can also contain one or more polymerizable groups which can be polymerized under similar conditions as the RMs used for PSA methods.

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

[0025] SA modes can also be used in combination with PSA modes. The LC medium of a display for such a combined mode thus contains both one or more RMs and one or more self-alignment additives.

[0026] Similar to the above-described conventional LC displays, the PSA displays can be operated as active matrix or passive matrix displays. In the case of active matrix displays, the individual pixels are usually addressed by means of integrated non-linear active elements such as transistors (e.g. thin-film transistors "TFTs"), whereas in the case of passive matrix displays, the addressing is usually carried out by means of multiplexing methods as known in the art.

[0027] The PSA displays 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, a polyimide, which can also be rubbed, or can be prepared by a photo-alignment method.

[0028] Especially for monitor as well as especially TV applications, there is a continuous demand for optimization of the response time as well as of the contrast and brightness (and thus also of the transmittance) of liquid crystal displays. The PSA approach can provide a key advantage here. Especially in the case of PS-VA, PS-IPS, PS-FFS and PS-Positive-VA-displays, a shortening of the response time in relation to the pretilt angle which is measurable in test cells can be achieved without significant detrimental effects on other parameters. SUMMARY

[0029] The present application is based on the object of providing novel suitable materials, optionally comprising reactive mesogens (RM), in LC media for use in displays which do not have or have to a reduced extent the above indicated disadvantages. Especially, there is still a need in the art for liquid crystal media with high reliability.

[0030] Further, it was an object of the present application to provide alternative media to the existing media known to the skilled person in order to enlarge the range of available materials which allow for a more specific optimization of a particular display.

[0031] A particular problem arises when displays with a particularly high contrast are required, because a high contrast requires a high elastic constant for a reduced scattering, but this leads to a slower response time. It was an object of the present application to provide a liquid crystal medium with a fast response time.

[0032] These objects have been achieved according to the present application by the materials and methods as described herein. In particular, it has been surprisingly found that the use of a liquid crystal host as described below allows to achieve the advantageous effects as mentioned above.

[0033] The present application relates to a liquid crystal medium comprising one or more compounds of formula I

[0034]

[0035] wherein

[0036] R 1 represents H, linear or branched alkyl or alkoxy having 1 to 15 carbon atoms, wherein in these radicals one or more CH2groups can each be replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms can be replaced by halogen, preferably alkyl or alkenyl having up to 7 C atoms,

[0037]

[0038] represents preferably

[0039] Y 1 represents H or CH3, preferably H,

[0040] n is 0 or 1, preferably 1

[0041] v is 1, 2, 3, 4, 5, or 6, and

[0042] The medium further comprises one or more compounds selected from the group of compounds of formulae IIA, IIB, IIC and IID,

[0043]

[0044]

[0045] wherein

[0046] R 2A , R 2B , R 2C

[0047] and R 2D each, independently of one another, represent H, alkyl or alkenyl having up to 15 C atoms which is unsubstituted, mono- or di-substituted by CN or CF3 or at least mono-substituted by halogen, wherein, in addition, one or more CH2groups in these radicals can be replaced by -O-, -S-, -C≡C-, -CF2O-, -OCF2-, -OC-O- or -O-CO- in such a way that O atoms are not directly connected to one another,

[0048] L 1 to L 4each, independently of one another, denotes F, Cl, CF3or CHF2,

[0049] Y denotes H, F, Cl, CF3, CHF2or CH3, preferably H or CH3, particularly preferably H,

[0050] Z 2 , Z 2B and Z 2D each, independently of one another, denotes a single bond, -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CH=CHCH2O-,

[0051] p denotes 0, 1 or 2,

[0052] q denotes 0 or 1, and

[0053] v denotes an integer from 1 to 6.

[0054] Surprisingly, by using a combination of a compound of the formula I with one or more compounds of the formulae IIA, MB, IIC and / or IID in a medium, a significantly smaller response time parameter γ1 / K1 can be achieved, which leads to a faster switching of a display comprising the medium, without the contrast of the display being negatively affected, or even being improved.

[0055] Preferred compounds of the formula I are selected from the following subformulae:

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] Very preferred compounds of the formula I are the compounds I-1 to I-14.

[0062] In a preferred embodiment, the medium comprises one or more compounds of the formula IA

[0063]

[0064] wherein the radicals and parameters occurring have the meanings given above in the formula I, and

[0065] R 2 denotes wherein r is 0, 1, 2, 3, 4, 5 or 6 and s is 1, 2 or 3.

[0066] Preferred compounds of formula IA are compounds IA-1 to IA-14.

[0067]

[0068]

[0069]

[0070] In the compounds of formulae IIA, IIB and IID, Z 2 may have the same or different meanings. In the compounds of formula IIB, Z 2 and Z 2B may have the same or different meanings. In the compounds of formula IID, Z 2 and Z 2D may have the same or different meanings.

[0071] In the compounds of formulae IIA, IIB, IIC and IID, R 2A , R 2B , R 2C and R 2D each preferably denote alkyl having 1 to 6 C atoms, in particular CH3, C2H5, n-C3H7, n-C4H9, n-C5H 11 .

[0072] In the compounds of formulae IIA, IIB and IID, L 1 , L 2 , L 3 and L 4 preferably denote L 1 = L 2 = F and L 3 = L 4 = F, furthermore L 1 = F and L 2 = Cl, L 1 = Cl and L 2 = F, L 3 = F and L 4 = Cl, L 3 = Cl and L 4 = F. In formulae IIA and IIB, Z 2 and Z 2B preferably each, independently of one another, denote a single bond, furthermore a -C2H4- bridge.

[0073] If in formula IIB, if Z 2 = -C2H4- or -CH2O-, Z 2Bpreferably a single bond, or if Z 2B = -C2H4- or -CH2O-, Z 2 preferably a single bond.

[0074] In formula IID, Z 2D preferably a single bond.

[0075] In the compounds of formulae IIA, IIB and IID, (O)C v H 2v+1 preferably denotes OC v H 2v+1 In the compounds of formula IIC, (O)C v H 2v+1 preferably denotes C v H 2v+1 .

[0076] In the compounds of formula IIC, L 3 and L 4 preferably each denote F.

[0077] Preferred compounds of formulae IIA, IIB, IIC and IID are shown below:

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] wherein the parameter a denotes 1 or 2, alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 -6 C atoms, and alkenyl denotes a straight-chain alkenyl radical having 2-6 carbon atoms, and (O) denotes an oxygen atom or a single bond. Alkenyl preferably denotes CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH- or CH3-CH=CH-(CH2)2-.

[0089] Particularly preferred mixtures according to the application comprise one or more compounds of the formulae IIA-2, IIA-8, IIA-10, IIA-16, II-18, IIA-40, IIA-41, IIA-42, IIA-43, IIB-2, IIB-10, IIB-16, IIC-1 and IID-4.

[0090] The proportion of compounds of the formulae IIA and / or IIB in the mixture as a whole is preferably at least 20% by weight.

[0091] Particularly preferred media according to the application comprise at least one compound of the formula IIC-1.

[0092]

[0093] wherein alkyl and alkyl* have the meanings indicated above, preferably in an amount of > 3% by weight, in particular > 5% by weight and particularly preferably 5 to 25% by weight.

[0094] In a preferred embodiment, the media according to the application comprise one or more compounds of the formula III

[0095]

[0096] wherein

[0097] R 11 and R 12 each, independently of one another, denote H, alkyl or alkoxy having 1 -15 C atoms, where one or more CH2groups in these radicals can each, independently of one another, be replaced by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, by -O-, -CO-O- or -O-CO- in such a way that the O atoms are not directly connected to one another, and in which, in addition, one or more H atoms can be replaced by halogen,

[0098] A 1 denote, independently of one another in each occurrence,

[0099] a) 1,4-cyclohexenylene or 1,4-cyclohexylene, wherein one or two non-adjacent CH2groups can be replaced by -O- or -S-,

[0100] b) 1,4-phenylene, wherein one or two CH groups can be replaced by N, or

[0101] c) a group selected from spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl,

[0102] wherein the groups a), b) and c) can be mono- or poly-substituted by halogen atoms,

[0103] n denotes 0, 1 or 2, preferably 0 or 1,

[0104] Z 1 independently of one another in each occurrence denote -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond, and

[0105] L 11 and L 12 each, independently of one another, denote F, CI, CF3or CHF2, preferably F, and

[0106] W denotes O or S, preferably S.

[0107] In a preferred embodiment of the application, the medium comprises one or more compounds of the formula III-1 and / or III-2

[0108]

[0109] where the groups occurring have the same meaning and preferences as given above in formula III

[0110] R 11 and R 12 each, independently of one another, is alkyl, alkenyl or alkoxy having up to 15 C atoms, more preferably one or two of them denote alkoxy and

[0111] L 11 and L 12 each denote F.

[0112] In preferred embodiments, the medium comprises one or more compounds of formula III-1 selected from the group of compounds of formulae III-1-1 to III-1-10, preferably of formula III-1-6,

[0113]

[0114]

[0115] wherein

[0116] each of alkyl and alkyl*independently of one another denotes a linear alkyl group having 1 -6 C atoms, each of alkenyl and alkenyl*independently of one another denotes a linear alkenyl group having 2-6 carbon atoms, each of alkoxy and alkoxy*independently of one another denotes a linear alkoxy group having 1 -6 C atoms, and L 11 and L 12 each independently of one another denotes F or CI, preferably both are F.

[0117] In preferred embodiments, the medium comprises one or more compounds of formula III-2 selected from the group of compounds of formulae III-2-1 to III-2-10, preferably of formula III-2-6,

[0118]

[0119]

[0120] wherein

[0121] each of alkyl and alkyl*independently of one another denotes a linear alkyl group having 1 -6 C atoms, each of alkenyl and alkenyl*independently of one another denotes a linear alkenyl group having 2-6 carbon atoms, each of alkoxy and alkoxy*independently of one another denotes a linear alkoxy group having 1 -6 C atoms, and L 1 and L 2 each independently of one another denotes F or CI, preferably both are F.

[0122] In preferred embodiments of the present application, the medium comprises one or more compounds of formula IIIA-1 and / or IIIA-2

[0123]

[0124] wherein L 11 and L 12 have the same meaning as given under formula III,

[0125] m and n, identically or differently, are 0, 1, 2, 3, 4, 5 or 6, preferably 1, 2 or 3, very preferably 1, (O) denotes O or a single bond,

[0126] Cy denotes an alicyclic radical having 3, 4 or 5 ring atoms, which is optionally substituted by alkyl or alkenyl having up to 3 C atoms, or halogen or CN, and preferably denotes cyclopropyl, cyclobutyl or cyclopentyl.

[0127] The compounds of the formulae IIIA-1 and / or IIIA-2 are contained in the medium, alternatively or in addition to the compounds of the formula III, preferably in addition to the compounds of the formula III.

[0128] Very preferred compounds of the formulae IIIA-1 and IIIA-2 are as follows:

[0129]

[0130]

[0131] wherein alkoxy denotes a straight-chain alkoxy group having 1 -6 C atoms.

[0132] In a preferred embodiment of the application, the medium comprises one or more compounds of the formula III-3

[0133]

[0134] wherein

[0135] R 11 , R 12 identically or differently, denote H, alkyl or alkoxy having 1 -15 C atoms, wherein one or more CH2groups in these radicals are optionally replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not directly connected to one another, and wherein, in addition, one or more H atoms can be replaced by halogen.

[0136] The compounds of the formula III-3 are preferably selected from the group of the compounds of the formulae III-3-1 to III-3-11 :

[0137]

[0138]

[0139] wherein R 12 denotes alkyl having 1 to 7 C atoms, preferably ethyl, n-propyl or n-butyl, or, alternatively, cyclopropylmethyl, cyclobutylmethyl or cyclopentylmethyl.

[0140] In a preferred embodiment of the application, the medium comprises one or more compounds of the formulae III-4 to III-6, preferably of the formula III-5,

[0141]

[0142] where the parameters have the meanings given above, R 11 preferably denotes linear alkyl and R 12 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0143] In a preferred embodiment, the medium comprises one or more compounds of the formula I, which are selected from the group of the compounds of the formulae III-7 to III-9, preferably of the formula III-8,

[0144]

[0145] where the parameters have the meanings given above, R 11 preferably denotes linear alkyl and R 12 preferably denotes alkoxy, each having 1 to 7 C atoms.

[0146] In a preferred embodiment, the medium comprises one or more compounds of the formula IV,

[0147]

[0148] where

[0149] R 41 denotes unsubstituted alkyl having 1 to 7 C atoms or unsubstituted alkenyl having 2 to 7 C atoms, preferably n-alkyl, particularly preferably having 2, 3, 4 or 5 C atoms, and

[0150] R 42 denotes unsubstituted alkyl having 1 to 7 C atoms or unsubstituted alkoxy having 1 to 6 C atoms (both preferably having 2 to 5 C atoms), unsubstituted alkenyl having 2 to 7 C atoms, preferably having 2, 3 or 4 C atoms, more preferably vinyl or 1-propenyl, in particular vinyl.

[0151] The compounds of the formula IV are preferably selected from the group of the compounds of the formulae IV-1 to IV-4,

[0152]

[0153] where

[0154] alkyl and alkyl’, independently of one another, denote alkyl having 1 to 7 carbon atoms, preferably having 2 to 5 C atoms,

[0155] alkenyl denotes an alkenyl radical having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably 2 C atoms,

[0156] alkenyl' denotes an alkenyl radical having 2 to 5 C atoms, preferably having 2 to 4 C atoms, particularly preferably having 2 to 3 C atoms, and

[0157] alkoxy denotes an alkoxy radical having 1 to 5 C atoms, preferably having 2 to 4 C atoms.

[0158] Preferably, the medium comprises one or more compounds selected from the group of compounds of the formulae IV-1-1 to IV-1-4

[0159]

[0160] Very preferably, the medium according to the application comprises one or more compounds of the formulae IV-2-1 and / or IV-2-2

[0161]

[0162] Very preferably, the medium according to the application comprises a compound of the formula IV-3, in particular a compound selected from the group of compounds of the formulae IV-3-1 to IV-3-5

[0163]

[0164]

[0165] Very preferably, the medium according to the application comprises a compound of the formula IV-4, in particular a compound selected from the group of compounds of the formulae IV-4-1 and IV-4-2

[0166]

[0167] The liquid-crystalline medium preferably additionally comprises one or more compounds of the formula IVa,

[0168]

[0169] wherein

[0170] R 41 and R 42 each, independently of the others, denote a linear alkyl, alkoxy, alkenyl, alkoxyalkyl or alkoxy radical having up to 12 C atoms, and denotes

[0171] Z 4The following represent single bonds: -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -C4H8-, -CF=CF-.

[0172] The preferred compounds of formula IVa are shown below:

[0173]

[0174] in

[0175] alkyl and

[0176] Alkyl* each independently represents a straight-chain alkyl group having 1 to 6 carbon atoms.

[0177] The medium according to the invention preferably comprises at least one compound of formula IVa-1 and / or formula IVa-2.

[0178] The proportion of the compound of formula IVa in the whole mixture is preferably at least 5% by weight.

[0179] Preferably, the medium comprises one or more compounds of formula IVb-1 to IVb-3.

[0180]

[0181] in

[0182] alkyl and alkyl* each independently represent straight-chain alkyl groups having 1 to 6 carbon atoms, and

[0183] alkenyl and alkenyl* each independently represent straight-chain alkenyl groups having 2 to 6 carbon atoms.

[0184] The proportion of biphenyls of formulas IV-1 to IV-3 in the entire mixture is preferably at least 3% by weight, and particularly ≥5% by weight.

[0185] Of the compounds of formulas IVb-1 to IVb-3, the compound of formula IVb-2 is particularly preferred.

[0186] The preferred biphenyl is

[0187]

[0188] Wherein alkyl* represents an alkyl group having 1 to 6 carbon atoms and preferably represents n-propyl. The media according to the invention particularly preferably comprise one or more compounds of formula IVb-1-1 and / or IVb-2-3.

[0189] In a preferred embodiment, the medium comprises one or more compounds of formula V.

[0190]

[0191] wherein

[0192] R 51 and R 52 each, independently of one another, have one of the meanings indicated above for R 41 and R 42 preferably denote alkyl, preferably n-alkyl, particularly preferably n-alkyl having 1 to 5 C atoms, alkoxy having 1 to 7 C atoms, preferably n-alkoxy, particularly preferably n-alkoxy having 2 to 5 C atoms, alkoxyalkyl having 2 to 7 C atoms, preferably having 2 to 4 C atoms, alkenyl or alkenyloxy, preferably alkenyloxy,

[0193] identically or differently, denote

[0194]

[0195] wherein

[0196] preferably denote

[0197] Z 51 , Z 52 each, independently of one another, denote -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO- or a single bond, preferably -CH2-CH2-, -CH2-O- or a single bond and particularly preferably a single bond, and

[0198] n is 1 or 2.

[0199] The compounds of the formula V are preferably selected from the group of the compounds of the formulae V-1 to V-17:

[0200]

[0201]

[0202] wherein R 1 and R 2 have the meanings indicated above for R 2A R 1 and R 2 preferably each, independently of one another, denote linear alkyl or alkenyl.

[0203] Preferred media comprise one or more compounds of the formulae V-1, V-3, V-4, V-6, V-7, V-10, V-11, V-12, V-14, V-15, and / or V-16

[0204] The mixtures according to the application very particularly preferably comprise compounds of the formulae V-10, V-12, V-16 and / or IV-1, in particular in a content of from 5 to 30%.

[0205] Preferred compounds of the formula V-10 are shown below:

[0206]

[0207]

[0208] The media according to the application particularly preferably comprise a combination of tricyclic compounds of the formula V-10a and / or V-10b with one or more bicyclic compounds of the formula IV-1. The total proportion of the combination of compounds of the formula V-10a and / or V-10b with bicyclic hexyl compounds selected from the formula IV-1 is from 5 to 40%, very particularly preferably from 15 to 35%.

[0209] Very particularly preferred mixtures comprise the compounds V-10a and CC-2-3

[0210]

[0211] The compounds V-10a and IV-1-1 are preferably present in the mixture in a concentration of from 15 to 35%, particularly preferably from 15 to 25%, especially preferably from 18 to 22%, based on the entire mixture.

[0212] Very particularly preferred mixtures comprise the compounds V-10b and IV-1-1 :

[0213]

[0214] The compounds V-10b and IV-1-1 are preferably present in the mixture in a concentration of from 15 to 35%, particularly preferably from 15 to 25%, especially preferably from 18 to 22%, based on the entire mixture.

[0215] Very particularly preferred mixtures comprise the following three compounds:

[0216]

[0217] The compounds V-10a, V-10b and IV-1-1 are preferably present in the mixture in a concentration of from 15 to 35%, particularly preferably from 15 to 25%, especially preferably from 18 to 22%, based on the entire mixture.

[0218] Preferred mixtures comprise at least one compound selected from the following compounds

[0219]

[0220] in which R41 and R 42 , and R 51 and R 52 have the meanings indicated above. Preferably in compounds V-6, V-7 and IV-1, R 41 and R 51 denote alkyl or alkenyl having 1 to 6 or 2 to 6 C atoms, respectively, and R 42 and R 52 denote alkenyl having 2 to 6 C atoms.

[0221] Preferred mixtures comprise at least one compound of the formulae V-6a, V-6b, V-7a, V-7b, IV-4-1, IV-4-2, IV-3a and IV-3b:

[0222]

[0223]

[0224] wherein alkyl denotes alkyl having 1 to 6 C atoms and alkenyl denotes alkenyl having 2 to 6 C atoms.

[0225] The compounds of the formulae V-6a, V-6b, V-7a, V-7b, IV-4-1, IV-4-2, IV-3a and IV-3b are preferably present in the mixtures according to the application in amounts of 1 to 40 % by weight, preferably 5 to 35 % by weight, very particularly preferably 10 to 30 % by weight.

[0226] In a preferred embodiment, the medium comprises one or more compounds of the formula Va

[0227]

[0228] wherein

[0229] R L denote H, straight-chain or branched alkyl or alkoxy having 1 to 15 carbon atoms, where one or more CH2groups in these radicals can each be replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, or -O-CO- in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms can be replaced by halogen,

[0230] X L denote F, CI, CN, CHF2, CF3, OCF3, or, identically or differently, one of the meanings of R L ,

[0231] Y Ldenotes H, F, CI or CH3,

[0232] The compounds of the formula Va are preferably selected from the group of compounds of the formulae Va-1 and Va-2

[0233]

[0234] wherein

[0235] R L1 have the meanings given above for the formula I and preferably denote alkyl or alkenyl having 1 to 7 carbon atoms, where a CH2group can be replaced by a cyclopropane-1,2-diyl group.

[0236] In a preferred embodiment, the medium comprises one or more compounds of the formula Vb selected from the following subformulae

[0237]

[0238] wherein R L1 have the meanings given above for the formula Va.

[0239] Very preferably, the medium comprises the compound Vb-2, wherein R L1 denote alkyl or alkenyl having up to 7 carbon atoms, in particular vinyl.

[0240] In a preferred embodiment of the present application, the medium additionally comprises one or more compounds of the formulae VI-1 to VI-9

[0241]

[0242]

[0243] wherein

[0244] R 7 each independently of one another have the meaning of R 2A indicated, and

[0245] w and x each independently of one another denote 1 to 6.

[0246] Particularly preferred is a mixture comprising at least one compound of the formula V-9.

[0247] In a preferred embodiment of the present application, the medium additionally comprises one or more compounds of the formulae VII-1 to VII-21,

[0248]

[0249]

[0250]

[0251] wherein

[0252] R denotes a linear alkyl or alkoxy group of 1 to 6 C atoms, (O) denotes -O- or a single bond, and m is 0, 1, 2, 3, 4, 5 or 6 and n is 0, 1, 2, 3 or 4.

[0253] R preferably denotes methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy.

[0254] The medium according to the application preferably comprises terphenyls of the formulae VII-1 to VII-21 in an amount of 2 to 30 % by weight, in particular 5 to 20 % by weight.

[0255] Particularly preferred are compounds of the formulae VII-1, VII-2, VII-4, VII-20 and VII-21. In these compounds, R preferably denotes alkyl, furthermore alkoxy, each having 1 to 5 C atoms. In the compounds of the formula VII-20, R preferably denotes alkyl or alkenyl, in particular alkyl. In the compounds of the formula VII-21, R preferably denotes alkyl.

[0256] If the mixture is to have a value of Δn > 0.1, it is preferred to use terphenyls in the mixture according to the application. Preferred mixtures comprise 2 to 20 % by weight of one or more terphenyl compounds selected from the group of the compounds VII-1 to VII-21.

[0257] Further preferred embodiments are listed below.

[0258] a) a liquid-crystalline medium comprising at least one compound of the formulae Z-1 to Z-7,

[0259]

[0260]

[0261] wherein R and alkyl have the meanings indicated above for formula III.

[0262] b) Preferred liquid-crystalline media according to the application comprise one or more substances comprising a tetrahydronaphthyl or naphthyl unit, for example compounds of the formulae N-1 to N-5,

[0263]

[0264] wherein R 1N and R 2N each independently of the other have the meanings indicated for R 2A preferably denote linear alkyl, linear alkoxy or linear alkenyl, and

[0265] Z 1 and Z 2 each, independently of one another, denotes -C2H4-, -CH=CH-, -(CH2)4-, -(CH2)3O-, -O(CH2)3-, -CH=CHCH2CH2-, -CH2CH2CH=CH-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, -CF=CH-, -CH=CF-, -CF2O-, -OCF2-, -CH2- or a single bond.

[0266] c) Preferred mixtures comprise one or more compounds selected from the group consisting of difluorodibenzochrysene of formula BC, chrysene of formula CR, fluoro-phenanthrene compounds of formulae PH-1 and PH-2, fluoro-dibenzofuran compounds of formulae BF-1 and BF-2,

[0267]

[0268] wherein

[0269] R B1 , R B2 , R CR1 , R CR2 , R 1 , R 2 each, independently of one another, have the meaning of R 2A c is 0, 1 or 2 and d denotes 1 or 2. R 1 and R 2 Preferably, each, independently of one another, denotes alkyl or alkoxy having 1 to 6 C atoms. The compounds of formulae BF-1 and BF-2 should not be identical to one or more compounds of formula I.

[0270] The mixtures according to the application preferably comprise the compounds of formulae BC, CR, PH-1, PH-2 and / or BF in an amount of 3 to 20 % by weight, in particular in an amount of 3 to 15 % by weight.

[0271] Particularly preferred compounds of formulae BC and CR are the compounds BC-1 to BC-7 and CR-1 to CR-5,

[0272]

[0273]

[0274] wherein

[0275] alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1 to 6 C atoms, and

[0276] alkenyl and

[0277] each R1independently of one another denotes linear or branched alkyl having 1 - 6 C atoms, alkenyl having 2 - 6 C atoms, or cycloalkyl having 3 - 6 C atoms.

[0278] Very particularly preferred are mixtures comprising one, two or three compounds of formula BC-2.

[0279] d) Preferred mixtures comprise one or more indane compounds of formula In,

[0280]

[0281] wherein

[0282] R 11 ,R 12 ,

[0283] R 13 each, independently of one another, denotes linear alkyl, alkoxy, alkoxyalkyl or alkenyl having 1 - 6 C atoms.

[0284] R 12 and R 13 denotes additionally halogen, preferably F,

[0285] denotes

[0286]

[0287] i denotes 0, 1 or 2.

[0288] Preferred compounds of formula In are the compounds of formulae In-1 to In-16 described below:

[0289]

[0290]

[0291]

[0292] Particularly preferred are compounds of formulae In-1, In-2, In-3 and In-4.

[0293] The compounds of formula In and of subformulae In-1 to In-16 are preferably used in the mixtures according to the application in concentrations of > 5 wt%, in particular 5 - 30 wt% and very particularly preferably 5 - 25 wt%.

[0294] e) Preferred mixtures additionally comprise one or more compounds of formulae L-1 to L-11,

[0295]

[0296] wherein

[0297] R and R1 Each of them independently possesses the above-mentioned characteristics for R in Equation IIA. 2A The meanings are as follows: alkyl indicates an alkyl group having 1-6 carbon atoms. The parameter s indicates 1 or 2.

[0298] Compounds of formulas L-1 to L-5 are preferably used at a concentration of 5-50 wt%, particularly 5-40 wt%, and very particularly preferably 10-40 wt%.

[0299] f) Preferred mixtures additionally contain one or more compounds of formula IIA-Y.

[0300]

[0301] Where R 11 and R 12 Having one of the meanings given in Equation I above, and L 1 and L 2 The same or different can represent F or Cl.

[0302] Preferred compounds of formula IIA-Y are selected from the following sub-formulas.

[0303]

[0304]

[0305] Wherein, Alkyl and Alkyl* each independently represent a straight-chain alkyl group having 1-6 carbon atoms, Alkoxy represents a straight-chain alkoxy group having 1-6 carbon atoms, Alkenyl and Alkenyl* each independently represent a straight-chain alkenyl group having 2-6 carbon atoms, and O represents an oxygen atom or a single bond. Alkenyl and Alkenyl* preferably represent CH2=CH-, CH2=CHCH2CH2-, CH3-CH=CH-, CH3-CH2-CH=CH-, CH3-(CH2)2-CH=CH-, CH3-(CH2)3-CH=CH-, or CH3-CH=CH-(CH2)2-.

[0306] The particularly preferred compounds of formula IIA-Y are selected from the following sub-formulas:

[0307]

[0308] Alkoxy and Alkoxy* have the meanings defined above and preferably represent methoxy, ethoxy, n-propyloxy, n-butyloxy or n-pentoxy.

[0309] The liquid-crystalline medium according to the application (herein also referred to as liquid-crystalline host mixture) is suitable for use in polymer stabilised displays. To this end, the medium according to the application optionally comprises one or more polymerisable P compounds:

[0310] P-Sp-A 1 -(Z 1 -A 2 ) z -R P

[0311] wherein each radical, independently of one another and on each occurrence identically or differently, has the following meanings:

[0312] P is a polymerisable group,

[0313] Sp is a spacer group or a single bond,

[0314] A 1 , A 2 is an aromatic, heteroaromatic, alicyclic or heterocyclic radical, preferably having 4 to 25 ring atoms, which can also contain fused rings, and which is unsubstituted, mono- or poly-substituted by L,

[0315] Z 1 is -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH2-CH2-CO-O-, -O-CO-CH2-CH2-, -CR 0 R 00 - or a single bond,

[0316] R 0 , R 00 is H or alkyl having 1 to 12 C atoms,

[0317] R is H, L or P-Sp-,

[0318] L is F, CI, -CN, P-Sp- or straight-chain, branched or cyclic alkyl with 1 to 25 C atoms, wherein one or more non-adjacent Chb groups are optionally replaced by -0-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another, and wherein one or more H atoms are each optionally replaced by P-Sp-, F or CI,

[0319] z is 0, 1, 2 or 3,

[0320] n1 is 1, 2, 3 or 4.

[0321] As used herein, the terms "active layer" and "switchable layer" mean a layer comprising one or more molecules having structural and optical anisotropy, for example LC molecules, in electro-optical displays, for example in LC displays, which change their orientation when subjected to an external stimulus, for example an electric or magnetic field, which leads to a change in the transmission of polarized or non-polarized light by the layer.

[0322] As used herein, the terms "tilt" and "tilt angle" are to be understood as meaning a tilted alignment of the LC molecules of an LC medium relative to the surface of the cell in an LC display, here preferably a PSA display. The tilt angle here denotes the average angle (< 90°) between the longitudinal molecular axis of the LC molecules (LC director) and the plane parallel to the outer plates forming the LC cell. A low numerical value of the tilt angle here, i.e. a large deviation from the 90° angle, corresponds to a large tilt. A suitable method for measuring the tilt angle is given in the Examples. Unless stated otherwise, the numerical values of the tilt angles disclosed in the context are related to this measurement method.

[0323] As used herein, the terms "reactive mesogen" and "RM" are to be understood as meaning a compound comprising a mesogenic or liquid-crystalline backbone, and one or more functional groups attached thereto which are suitable for polymerization, and which are also referred to as "polymerizable groups" or "P".

[0324] The term "polymerizable compound" as used herein, unless otherwise indicated, is to be understood as meaning a monomeric compound which is polymerizable.

[0325] As used herein, the term "low-molecular-weight compound" is to be understood as meaning a monomeric and / or not prepared by a polymerization reaction compound, which is opposite to a "polymerizable compound" or "polymer".

[0326] As used herein, the term "non-polymerizable compound" is to be understood as meaning a compound which does not comprise functional groups suitable for polymerization under the conditions usually applied for the polymerization of RMs.

[0327] As used herein, the term "mesogenic group" is known to the person skilled in the art and described in the literature and it denotes a group which contributes essentially to the generation of a liquid crystalline (LC) phase in low-molecular weight or polymeric substances due to its anisotropy of attraction and repulsion interactions. A compound comprising a mesogenic group (mesogenic compound) does not necessarily have an LC phase itself. A mesogenic compound can also exhibit LC phase behaviour only after mixing with other compounds and / or after polymerisation. Typical mesogenic groups are for example rigid rod-like or disc-like units. The 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.

[0328] As used herein, the terms "optically active" and "chiral" are synonymous for materials which can induce a helical pitch in a nematic host material, also referred to as "chiral dopant".

[0329] As used herein, the term "spacer group" (hereinafter also referred to as "Sp") is known to the person skilled in the art and described in the literature, see for example Pure Appl. Chem. 2001, 73(5), 888 and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. As used herein, the term "spacer group" or "spacer" denotes a flexible group, for example it is an alkylene group, which is attached to a mesogenic group or to a polymerisable group (one or more) in a polymerisable mesogenic compound.

[0330] In the context of,

[0331]

[0332] denotes a trans-1,4-cyclohexylene ring.

[0333] In the group , the single bond shown between two ring atoms can be attached to any free position of the phenyl ring.

[0334] In the context of,

[0335] "Carbogroup" denotes a mono- or polyvalent organic group comprising at least one carbon atom, wherein the group does not contain additional atoms (such as -C≡C-) or optionally contains one or more additional atoms, such as N, O, S, B, P, Si, Se, As, Te or Ge (such as carbonyl groups etc.). The term "hydrocarbyl group" denotes a carbogroup, which additionally comprises one or more H atoms and optionally one or more heteroatoms, such as N, O, S, B, P, Si, Se, As, Te or Ge.

[0336] "Halogen" denotes F, Cl, Br or I, preferably F or Cl.

[0337] -CO-, -C(=O)- and -C(O)- denote a carbonyl group, i.e.

[0338] Carbogroups or hydrocarbyl groups can be saturated or unsaturated groups. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Carbogroups or hydrocarbyl groups having more than 3 C atoms can be linear, branched and / or cyclic and can also comprise spiro connections or fused rings.

[0339] The terms "alkyl", "aryl", "heteroaryl" and the like also include polyvalent groups, such as alkylene, arylene, heteroarylene and the like.

[0340] The term "aryl" denotes an aromatic carbon group or a group derived therefrom. The term "heteroaryl" denotes an "aryl" group as defined above comprising one or more heteroatoms, preferably selected from N, O, S, Se, Te, Si and Ge.

[0341] Preferred carbogroups and hydrocarbyl groups are optionally substituted, linear, branched or cyclic alkyl, alkenyl, alkynyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy and alkoxycarbonyloxy having 1 to 40, preferably 1 to 20, very preferably 1 to 12 C atoms, optionally substituted aryl or aryloxy having 5 to 30, preferably 6 to 25 C atoms, or optionally substituted alkylaryl, arylalkyl, alkylaryloxy, arylalkyloxy, arylcarbonyl, aryloxycarbonyl, arylcarbonyloxy and aryloxycarbonyloxy having 5 to 30, preferably 6 to 25 C atoms, wherein one or more C atoms can also be replaced by a heteroatom, preferably selected from N, O, S, Se, Te, Si and Ge.

[0342] Further preferred carbogroups and hydrocarbyl groups are C1-C 20 alkyl, C2-C 20 alkenyl, C2-C 20 alkynyl, C3-C 20 allyl, C4-C 20 alkyldienyl, C4-C 20 polyenyl, C6-C 20cycloalkyl, C4-C 15 cycloalkenyl, C6-C 30 aryl, C6-C 30 alkylaryl, C6-C 30 aralkyl, C6-C 30 alkylaryloxy, C6-C 30 arylalkoxy, C2-C 30 heteroaryl, C2-C 30 heteroaryloxy.

[0343] Particularly preferred are C1-C 12 alkyl, C2-C 12 alkenyl, C2-C 12 alkynyl, C6-C 25 aryl and C2-C 25 heteroaryl.

[0344] Further preferred carbon-based and hydrocarbon-based radicals are straight-chain, branched or cyclic alkyl radicals having 1 to 20, preferably 1 to 12, C atoms which are unsubstituted or mono- or poly-substituted by F, Cl, Br, I or CN, and in which one or more non-adjacent CH2groups can each be replaced, independently of one another, by -C(R x )=C(R x )-, -C≡-, -N(R x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O and / or S atoms are not linked directly to one another.

[0345] R x preferably 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 can be replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- and in which one or more H atoms can be replaced by F or Cl, or an optionally substituted aryl or aryloxy radical having 6 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy radical having 2 to 30 C atoms.

[0346] Preferred alkyl radicals are, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decanyl, n-undecyl, n-dodecanyl, dodecanyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl and the like.

[0347] Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl and the like.

[0348] Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl and the like.

[0349] Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxyethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 2-methylbutoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decanyloxy, n-undecyloxy, n-dodecyloxy and the like.

[0350] Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino and the like.

[0351] Aryl and heteroaryl groups can be monocyclic or polycyclic, i.e. they can contain one ring (e.g. phenyl) or two or more rings, which can also be fused (e.g. naphthyl) or covalently bound (e.g. biphenyl), or comprise a combination of fused and linked rings. Heteroaryl contains one or more heteroatoms, preferably selected from O, N, S and Se.

[0352] Particularly preferred are mono-, bi- or tricyclic aryl groups having 6 to 25 C atoms and mono-, bi- or tricyclic heteroaryl groups 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 groups, wherein, in addition, one or more CH groups can be replaced by N, S or O in such a way that the O and / or S atoms are not directly linked to one another.

[0353] Preferred aryl groups are, for example, phenyl, biphenyl, terphenyl, [1,1 ':3',1 "] -terphen-2'-yl, naphthyl, anthryl, binaphthyl, phenanthryl, 9,10-dihydro-phenanthryl, pyrenyl, dihydropyrenyl, pyromethene, naphthacene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene and the like.

[0354] 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 ring groups, such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, purine, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pyrazimoimidazole, quinoxaloimidazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, benzothiazole, benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pteridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthylidine, azacarbazole, benzocarbolin, phenanthridine, phenanthroline, thieno[2,3b]thiophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiophene, benzothiadiazolothiophene, or combinations of these groups.

[0355] The aryl and heteroaryl groups mentioned above and below can also be substituted by alkyl, alkoxy, thioalkyl, fluorine, fluoroalkyl or other aryl or heteroaryl groups.

[0356] The (non-aromatic) alicyclic and heterocyclic groups both comprise saturated rings, i.e. rings which contain only single bonds, and also partially unsaturated rings, i.e. those which can also contain multiple bonds. The heterocyclic rings contain one or more heteroatoms, preferably selected from Si, O, N, S and Se.

[0357] The (non-aromatic) alicyclic and heterocyclic groups can be monocyclic, i.e. contain only one ring (for example cyclohexane), or polycyclic, i.e. contain multiple rings (for example decalin or bicyclooctane). Saturated groups are particularly preferred. Furthermore, preference is given to mono-, bi- or tricyclic groups having 5 to 25 ring atoms, 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 can be replaced by Si and / or one or more CH groups can be replaced by N and / or one or more non-adjacent CH2 groups can be replaced by -O- and / or -S-.

[0358] 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 fused groups, such as tetrahydronaphthalene, decahydronaphthalene, indane, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, octahydro-4,7-methanoindane-2,5-diyl.

[0359] 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 for increasing the glass transition temperature (Tg) of the polymer, in particular bulky groups, such as tert-butyl or optionally substituted aryl groups.

[0360] Preferred substituents, also referred to below as "L S ", are, for example, F, CI, Br, I, -CN, -NO2, -NCO, -NCS, -OCN, -SCN, -C(=O)N(R x )2, -C(=O)Y 1 , -C(=O)R x , -N(R x )2, straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy with 1 to 25 C atoms, in which one or more H atoms can optionally be replaced by F or CI, optionally substituted silyl with 1 to 20 Si atoms, or optionally substituted aryl with 6 to 25, preferably 6 to 15 C atoms.

[0361] in which R x denotes H, F, CI, CN, or straight-chain, branched or cyclic alkyl with 1 to 25 C atoms, in which one or more non-adjacent CH2-groups are optionally replaced, by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O- and / or S-atoms are not directly adjacent to one another, and in which one or more H atoms are each optionally replaced by F, CI, P- or P-Sp- and

[0362] Y 1 denotes halogen.

[0363] "Substituted silyl or aryl" preferably denotes that it is substituted by halogen, -CN, R 0 , -OR 0 , -CO-R 0 , -CO-O-R 0-O-CO-R 0 or -O-CO-O-R 0 substituted, where R 0 denotes H or alkyl having 1 to 20 C atoms.

[0364] Particularly preferred substituents L are, for example, F, CI, CN, NO2, CH3, C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5, furthermore phenyl.

[0365] A 1 and A 2 very preferably denotes where L has one of the meanings indicated above and r denotes 0, 1, 2, 3 or 4, particularly preferably

[0366] preferably

[0367] The polymerisable groups P are groups which are suitable for a polymerisation reaction (for example radical or ionic chain polymerisation, addition polymerisation or condensation polymerisation) or for a polymer-analogous reaction (for example addition or condensation on a polymer backbone). Particularly preferred are groups which are suitable for chain polymerisation, in particular those which contain a C=C double bond or a -C≡C- triple bond, and groups which are suitable for ring-opening polymerisation, for example oxetane or epoxy groups.

[0368] Preferred groups P are selected from the group consisting of CH2=CW 1 -CO-O-, CH2=CW 1 -CO-, CH2=CW 2 -(O) k3 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, CH3-CH=CH-O-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, HO-CW 2 W 3 -, HS-CW 2 W 3 -, HW 2 N-, HO-CW 2W 3 -NH-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O) k2 -, Phe-CH=CH-, HOOC-, OCN-, and W 4 W 5 W 6 Si-, wherein W 1 denotes H, F, CI, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, CI or CH3, W 2 and W 3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each, independently of one another, denote CI, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each, independently of one another, denote H, CI or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, which is optionally substituted by one or more groups L as defined above, different from P-SP-, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.

[0369] Very preferred groups P are selected from the group consisting of CH2=CW 1 -CO-O-, CH2=CW 1 - CH2=CW 2 -O-, CH2=CW 2 -, CW 1 =CH-CO-(O) k3 -, CW 1 =CH-CO-NH-, CH2=CW 1 -CO-NH-, (CH2=CH)2CH-OCO-, (CH2=CH-CH2)2CH-OCO-, (CH2=CH)2CH-O-, (CH2=CH-CH2)2N-, (CH2=CH-CH2)2N-CO-, CH2=CW 1 -CO-NH-, CH2=CH-(COO) k1 -Phe-(O) k2 -, CH2=CH-(CO) k1 -Phe-(O)k2 -, Phe-CH=CH- and W 4 W 5 W 6 Si-, wherein W 1 denotes H, F, CI, CN, CF3, phenyl or alkyl having 1 to 5 C atoms, in particular H, F, CI or CH3, W 2 and W 3 each, independently of one another, denote H or alkyl having 1 to 5 C atoms, in particular H, methyl, ethyl or n-propyl, W 4 , W 5 and W 6 each, independently of one another, denote CI, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, W 7 and W 8 each, independently of one another, denote H, CI or alkyl having 1 to 5 C atoms, Phe denotes 1,4-phenylene, k1, k2 and k3 each, independently of one another, denote 0 or 1, k3 preferably denotes 1, and k4 denotes an integer from 1 to 10.

[0370] Very preferred groups P are selected from the group consisting of CH2=CW 1 -CO-O-, in particular CH2=CH-CO-O-, CH2=C(CH3)-CO-O- and CH2=CF-CO-O-, furthermore CH2=CH-O-, (CH2=CH)2CH-O-CO-, (CH2=CH)2CH-O-, and

[0371] Other particularly preferred polymerisable groups P are selected from the group consisting of vinyloxy, acrylate, methacrylate, fluorinated acrylate, chlorinated acrylate, oxetane and epoxy, most preferably from acrylate and methacrylate.

[0372] If the spacer group Sp is different from a single bond, it is preferably of the formula Sp"-X", such that each group P-Sp- corresponds to the formula R-Sp"-X"-, wherein

[0373] Sp" denotes a straight-chain or branched alkylene group having 1 to 20, preferably 1 to 12 C atoms, which is optionally mono- or poly-substituted by F, CI, Br, I or CN, and wherein, in addition, one or more non-adjacent CH2 groups are each, independently of one another, replaced by -O-, -S-, -NH-, -N(R 0 )-, -Si(R 0 R 00 )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R 00)-CO-O-, -O-CO-N(R 0 )-, -N(R 0 )-CO-N(R 00 )-, -CH=CH- or -C≡C- instead of O and / or S atoms not being directly linked to each other,

[0374] X"represents -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R 0 )-, -N(R 0 )-CO-, -N(R 0 )-CO-N(R 00 )-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CR 0 -, -CY 2 =Y 3 -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or a single bond,

[0375] R 0 and R 00 each, independently of the others, denote H or alkyl having 1 -20 C atoms, and

[0376] Y 2 and Y 3 each, independently of the others, denote H, F, Cl or CN.

[0377] X"preferably is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR 0 -, -NR 0 -CO-, -NR 0 -CO-NR 00 - or a single bond.

[0378] Typical spacer groups Sp and -Sp"-X"are, for example, -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -O-CO-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-O-, -(CH2CH2O) q1 -CH2CH2-, -CH2CH2-S-CH2CH2-, -CH2CH2-NH-CH2CH2- or -(SiR0 R 00 -O) p1 - where p1 is an integer from 1 to 12, q1 is an integer from 1 to 3, and R 0 and R 00 It has the meaning mentioned above.

[0379] The particularly preferred groups Sp and -Sp"-X"- are -(CH2). p1 -、-(CH2) p1 -O-、-(CH2) p1 -O-CO-、-(CH2) p1 -CO-O-、-(CH2) p1 -O-CO-O-, where p1 and q1 have the meanings stated above.

[0380] The particularly preferred group Sp" in each case is a straight-chain 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.

[0381] In a preferred embodiment of the invention, compounds of formula P and its subforms contain spacer groups Sp substituted with one or more polymerizable groups P, such that the group Sp-P corresponds to Sp(P). s s is ≥2 (branched polymerizable groups).

[0382] The preferred P compound according to this preferred embodiment is one in which s is 2, i.e., a compound containing the group Sp(P)2. The most preferred P compound according to this preferred embodiment contains a group selected from the following formulas:

[0383] -X-alkyl-CHPP S1

[0384] -X-alkyl-CH((CH2) aa P)((CH2) bb P) S2

[0385] -XN((CH2) aa P)((CH2) bb P) S3

[0386] -X-alkyl-CHP-CH2-CH2P S4

[0387] -X-alkyl-C(CH2P)(CH2P)-C aa H 2aa+1S5

[0388] - X-alkyl-CHP-CH2P S6

[0389] - X-alkyl-CPP-C aa H 2aa+1 S7

[0390] - X-alkyl-CHPCHP-C aa H 2aa+1 S8

[0391] wherein P is as defined in formula P,

[0392] alkyl denotes a single bond or a straight-chain or branched alkylene group having 1 to 12 C atoms which is unsubstituted or mono- or poly-substituted by F, Cl or CN, and wherein one or more non-adjacent CH2groups can each be replaced, independently of one another, by -C(R 0 ) = C(R 0 )-, -CºC-, -N(R 0 )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- such that O and / or S atoms are not linked directly to one another, where R 0 have the meanings indicated above,

[0393] aa and bb each, independently of one another, denote 0, 1, 2, 3, 4, 5 or 6,

[0394] X has one of the meanings indicated for X", and is preferably O, CO, SO2, O-CO-, CO-O or a single bond.

[0395] Preferred spacer groups Sp(P)2are selected from formulae S1, S2 and S3.

[0396] Very preferred spacer groups Sp(P)2are selected from the following subformulae:

[0397] -CHPP S1a

[0398] - O-CHPP S1b

[0399] - CH2-CHPP S1c

[0400] - OCH2-CHPP S1d

[0401] - CH(CH2-P)(CH2-P) S2a

[0402] - OCH(CH2-P)(CH2-P) S2b

[0403] -CH2-CH(CH2-P)(CH2-P) S2c

[0404] -OCH2-CH(CH2-P)(CH2-P) S2d

[0405] -CO-NH((CH2)2P)((CH2)2P) S3a

[0406] In the compounds of the formula P and the subformulae thereof as described above and below, P is preferably selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoropropenoate, chloropropenoate, oxetane and epoxide, most preferably from acrylate and methacrylate.

[0407] More preferred are the compounds of the formula P and the subformulae thereof as described above and below, wherein all polymerizable groups P present in the compounds have the same meaning and very preferably denote acrylate or methacrylate, most preferably methacrylate.

[0408] In the compounds of the formula P and the subformulae thereof as described above and below, R preferably denotes P-Sp-.

[0409] More preferred are the compounds of the formula P and the subformulae thereof as described above and below, wherein Sp denotes a single bond or -(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 the CO-group, respectively, is attached to the phenyl ring.

[0410] More preferred are the compounds of the formula P and the subformulae thereof as described above and below, wherein at least one group Sp is a single bond.

[0411] More preferred are the compounds of the formula P and the subformulae thereof as described above and below, wherein at least one group Sp is different from a single bond and is preferably 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 , the O-atom or the CO-group is respectively attached to the phenyl ring.

[0412] very preferred radicals -A in formula P 1 -(Z-A 2 ) z - is selected from the following formulae

[0413]

[0414] wherein at least one phenyl ring is substituted by at least one radical L and the phenyl ring is optionally further substituted by one or more radicals L or P-Sp-.

[0415] Preferred compounds of formula P and its subformulae are selected from the following preferred embodiments, including any combination thereof:

[0416] - all radicals P in the compound have the same meaning,

[0417] - A 1 -(Z-A 2 ) z - is selected from formulae A1, A2 and A5,

[0418] - the compound exactly contains two polymerizable groups (represented by radicals P),

[0419] - the compound exactly contains three polymerizable groups (represented by radicals P),

[0420] - P is selected from the group consisting of acrylate, methacrylate and oxetane, very preferably acrylate or methacrylate,

[0421] - P is methacrylate,

[0422] - all radicals Sp are a single bond,

[0423] - at least one of the radicals Sp is a single bond and at least one of the radicals Sp is different from a single bond,

[0424] - when different from a single bond, Sp is -(CH2) p2 -, -(CH2) p2 - O-, -(CH2) p2 - CO-O-, -(CH2) p2 - O-CO-, wherein p2 is 2, 3, 4, 5 or 6 and the O-atom or the CO-group is respectively attached to the phenyl ring,

[0425] - Sp is a single bond or represents -(CH2) p2 -, -(CH2) p2 - O-, -(CH2) p2-CO-O-, -(CH2) p2 -O-CO-, wherein p2 is 2, 3, 4, 5 or 6, and the O-atom or the CO-group is respectively attached to the phenyl ring,

[0426] -R represents P-Sp-,

[0427] -R does not represent or contain a polymerizable group,

[0428] -R does not represent or contain a polymerizable group and represents a linear, branched or cyclic alkyl group with 1 to 25 C atoms, wherein one or more non-adjacent CH2-groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- in such a way that O-atoms and / or S-atoms are not attached to each other directly, and wherein one or more H atoms are each optionally replaced by F, Cl or L a , and

[0429] -L or L' represents F, Cl or CN,

[0430] -L is F.

[0431] Suitable and preferred compounds of formula P are selected from the following formulae:

[0432]

[0433]

[0434]

[0435]

[0436] wherein each group has the following meaning:

[0437] P 1 , P 2 and P 3 each, independently of one another, represent an acrylate group or a methacrylate group,

[0438] Sp 1 , Sp 2 and Sp 3 each, independently of one another, represent a single bond or a spacer group (with one of the meanings described above and below for Sp), and especially preferably represent -(CH2) p1 -, -(CH2) p1 -O-, -(CH2) p1 -CO-O-, -(CH2) p1 -O-CO-, or -(CH2) p1 -O-CO-O-, wherein p1 is an integer from 1 to 12, and further wherein the group P1 -Sp 1 -、P 2 -Sp 2 -and P 3 -Sp 3 One or more of - can represent R aa The condition is the presence of 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 ,

[0439] R aa Represents H, F, Cl, CN, or a straight-chain or branched alkyl group having 1 to 25 C atoms, wherein one or more other non-adjacent CH2 groups may also be independently separated by C(R) 0 )=C(R 00 )-、-C≡C-、-N(R 0 -, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O- can be substituted in such a way that the O and / or S atoms are not directly connected to each other, and one or more of the other H atoms can be replaced by F, Cl, CN or P. 1 -Sp 1 - Alternatively preferred are straight-chain or branched groups having 1 to 12 carbon atoms, optionally mono- or polyfluoroalkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy, or alkoxycarbonyloxy (wherein the alkenyl and alkynyl groups have at least two carbon atoms and the branched groups have at least three carbon atoms).

[0440] R 0 R 00 Each of these terms independently, and each instance may be identical or different, representing H or an alkyl group having 1 to 12 carbon atoms.

[0441] R y and R z Each can be independently represented as H, F, CH3, or CF3.

[0442] X 1 X 2 and X 3 Each can independently represent -CO-O-, -O-CO-, or a single bond.

[0443] Z 1 Represents -O-, -CO-, -C(R) y R z - or -CF2CF2-,

[0444] Z 2 and Z 3 each, independently of one another, denotes -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -OCF2- or -(CH2) n - wherein n is 2, 3 or 4,

[0445] L denotes, on each occurrence identically or differently, F, CI, CN or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms, preferably F,

[0446] L' and L" each, independently of one another, denote H, F or CI,

[0447] k denotes 0 or 1,

[0448] r denotes 0, 1, 2, 3 or 4,

[0449] s denotes 0, 1, 2 or 3,

[0450] t denotes 0, 1 or 2,

[0451] x denotes 0 or 1.

[0452] Especially preferred are compounds of the formulae P2, P13, P17, P22, P23, P24, P30, P31 and P32.

[0453] More preferred are tri -reactive compounds P15 to P30, in particular P17, P18, P19, P22, P23, P24, P25, P26, P30, P31 and P32.

[0454] In the compounds P1 to P32, the group

[0455] Preferably

[0456] wherein L has on each occurrence identically or differently one of the meanings given above or below, and is preferably F, CI, CN, NO2, CH3, C2H5, C(CH3)3, CH(CH3)2, CH2CH(CH3)C2H5, OCH3, OC2H5, COCH3, COC2H5, COOCH3, COOC2H5, CF3, OCF3, OCHF2, OC2F5 or P-Sp-, very preferably F, CI, CN, CH3, C2H5, OCH3, COCH3, OCF3 or P-Sp-, more preferably F, CI, CH3, OCH3, COCH3 or OCF3, especially F or CH3.

[0457] The medium according to the application comprises one or more chiral dopants. Preferably the absolute value of the helical twisting power (HTP) of these chiral dopants is in the range of 1 pm -1 to 150 pm -1 preferably in the range of 10 pm -1 to 100 pm -1 In case the medium comprises two or more chiral dopants, these can have opposite signs of their HTP values. For some specific embodiments this condition is preferred as it allows to compensate the chirality of the respective compounds to some extent and thus can be used to compensate various temperature dependent properties of the resulting medium in a device. Generally, however, it is preferred that the majority of the chiral compounds, preferably all of the chiral compounds present in the medium according to the application have the same sign of their HTP values.

[0458] Preferably the chiral dopants present in the medium according to the present application are mesogenic compounds and most preferably they exhibit a mesophase on their own.

[0459] In a preferred embodiment of the application the medium comprises two or more chiral compounds having the same algebraic sign of the HTP.

[0460] The temperature dependence of the HTP of the individual compounds can be high or low. The temperature dependence of the pitch of the medium can be compensated by mixing compounds having different temperature dependence of the HTP in the respective ratio.

[0461] For optically active components a variety of chiral dopants are available to the skilled person, some of which are commercially available, e.g. cholesteryl nonanoate, R- and S-811, R- and S-1011, R- and S-2011, R- and S-3011, R- and S-4011 or CB15 (all from Merck KGaA, Darmstadt).

[0462] Particularly suitable dopants are compounds containing one or more chiral groups and one or more mesogenic groups, or one or more aromatic or alicyclic groups forming mesogenic groups with the chiral groups.

[0463] Suitable chiral groups are for example chiral branched hydrocarbon groups, chiral glycols, binaphthols or dioxolanes, furthermore mono- or polyvalent chiral groups selected from the group consisting of sugar derivatives, sugar alcohols, sugar acids, lactic acid, chiral substituted glycols, steroid derivatives, terpene derivatives, amino acids or sequences of several, preferably 1 to 5, amino acids.

[0464] Preferred chiral groups are sugar derivatives, such as glucose, mannose, galactose, fructose, arabinose and dextrose; sugar alcohols, such as sorbitol, mannitol, iditol, galactitol or a dehydrated derivative thereof, in particular a dianhydrohexitol, such as dianhydrosorbitol (1,4:3,6-dianhydro-D-sorbitol, isosorbide), dianhydromannitol (isosorbitol) or dianhydroiditol (isoiditol), sugar acids, such as gluconic acid, gulonic acid and ketogulonic acid, chiral substituted diol groups, such as mono- or oligo-ethylene glycol or propylene glycol, in which one or more CH2groups are substituted by alkyl or alkoxy, amino acids, such as alanine, valine, phenylglycine or phenylalanine or a sequence of 1 to 5 of these amino acids, steroid derivatives, such as a cholesteryl or cholic acid group, terpene derivatives, such as menthyl, neomenthyl, campheyl, pineyl, terpineyl, isolongifolyl, fenchyl, carreyl, myrthenyl, nopyl, geraniyl, linaloyl, neryl, citronellyl or dihydrocitronellyl.

[0465] The medium according to the application preferably comprises a chiral dopant selected from the group of known chiral dopants. Suitable chiral groups and mesogenic chiral compounds are described, for example, in DE 34 25 503, DE 35 34 777, DE 35 34 778, DE 35 34 779 and DE 35 34 780, DE 43 42 280, EP 01 038 941 and DE 195 41 820. Examples are also the compounds listed in Table F below.

[0466] The chiral compounds preferably used according to the application are selected from the formulae shown below.

[0467] Particularly preferred are chiral dopants selected from the compounds of the following formulae A-I to A-III and A-Ch:

[0468]

[0469] wherein

[0470] R a11 , R a12 and R b12 independently of one another, denote an alkyl group having 1 -15 C atoms, wherein, in addition, one or more non-adjacent CH2groups can each be replaced, independently of one another, by -C(R z ) = C(R z-, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO-, or -O-CO-O- are substituted in such a way that the O and / or S atoms are not directly connected to each other, and wherein, in addition, one or more H atoms may be substituted by F, Cl, Br, I or CN, preferably alkyl, more preferably n-alkyl, provided that R a12 With R b12 different

[0471] R a21 and R a22 Each of the above can independently represent an alkyl group having 1-15 carbon atoms, wherein, in addition, one or more non-adjacent CH2 groups can each be independently represented by -C(R) z )=C(R z -, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO-, or -O-CO-O- are substituted in such a way that the O and / or S atoms are not directly connected to each other, and wherein, in addition, one or more H atoms can be replaced by F, Cl, Br, I or CN, preferably both being alkyl, more preferably n-alkyl.

[0472] R a31 R a32 and R b32 Each of the above independently represents an alkyl group having a straight chain and branches of 1-15 C atoms, wherein, in addition, one or more non-adjacent CH2 groups may each be independently represented by -C(R) z )=C(R z -, -C≡C-, -O-, -S-, -CO-, -CO-O-, -O-CO-, or -O-CO-O- are substituted in such a way that the O and / or S atoms are not directly connected to each other, and wherein, in addition, one or more H atoms can be substituted by F, Cl, Br, I, or CN.

[0473] Alkyl groups are preferred, and n-alkyl groups are more preferred, provided that R a32 With R b32 different,

[0474] R z It can be represented by H, CH3, F, Cl, or CN, with H or F being preferred.

[0475] R 8 With the R given above a11 One meaning is that alkyl is preferred, and more preferably a n-alkyl group having 1-15 carbon atoms.

[0476] Z 8 It represents -C(O)O-, -CH2O-, -CF2O- or a single bond, preferably -C(O)O-.

[0477] A 11A 12 are as defined below or alternatively denote

[0478]

[0479] A 12 denote

[0480]

[0481] preferably

[0482]

[0483]

[0484] wherein

[0485] L 12 independently of one another in each occurrence denote halogen, CN or alkyl, alkenyl, alkoxy or alkenyloxy having up to 12 C atoms, and wherein one or more H atoms are optionally replaced by halogen, preferably by methyl, ethyl, Cl or F, especially preferably by F.

[0486] A 21 denote

[0487]

[0488] A 22 having the meaning given for A 12

[0489] A 31 having the meaning given for A 11

[0490]

[0491] A 32 having the meaning given for A 12

[0492] n2 is, on each occurrence, identically or differently, 0, 1 or 2, and n3 is 1, 2 or 3, and

[0493] r is 0, 1, 2, 3 or 4.

[0494] especially preferably is a dopant selected from the group consisting of compounds of the following formulae:

[0495]

[0496]

[0497] wherein ​​​

[0498] m is, on each occurrence, identically or differently, an integer from 1 to 9 and

[0499] n is, on each occurrence, identically or differently, an integer from 2 to 9.

[0500] Particularly preferred compounds of formula A are compounds of formula A-III.

[0501] Further preferred dopants are derivatives of isosorbide, isomannide or isoidide of the following formula A-IV:

[0502]

[0503] wherein the radicals are

[0504] (di-sorbitol),

[0505] (di-mannitol), or

[0506] (di-iditol),

[0507] preferably di-sorbitol,

[0508] and chiral glycols, such as, for example, diphenyl glycol (hydrobenzoin), in particular mesogenic hydrobenzoin derivatives of the following formula A-V:

[0509]

[0510] including the not shown (S,S) enantiomer,

[0511] wherein

[0512]

[0513] and

[0514] are each, independently of one another, 1,4-phenylene (which can also be mono-, di- or tri-substituted by L) or 1,4-cyclohexylene,

[0515] L is H, F, CI, CN or alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy having 1 to 7 carbon atoms, optionally halogenated,

[0516] c is 0 or 1,

[0517] X is CH2or -C(O)-,

[0518] Z 0 -COO-, -OCO-, -CH2CH2- or a single bond, and

[0519] R 0 is alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkylcarbonyloxy having 1 to 12 carbon atoms.

[0520] Examples of compounds of the formula IV are:

[0521]

[0522]

[0523] Compounds of the formula A-IV are described in WO 98 / 00428. Compounds of the formula A-V are described in GB-A-2,328,207.

[0524] Very particularly preferred dopants are chiral binaphthyl derivatives as described in WO 02 / 94805, chiral binaphthol ketal derivatives as described in WO 02 / 34739, chiral TADDOL derivatives as described in WO 02 / 06265 and chiral dopants having at least one fluorinated bridging group and a terminal or central chiral group as described in WO 02 / 06196 and WO 02 / 06195.

[0525] Particularly preferred are chiral compounds of the formula A-VI

[0526]

[0527] wherein

[0528] X 1 , X 2 , Y 1 and Y 2 each, independently of one another, F, CI, Br, I, CN, SCN, SF5, straight-chain or branched alkyl having 1 to 25 C atoms which is unsubstituted, mono- or poly-substituted by F, CI, Br, I or CN and wherein, furthermore, one or more non-adjacent CH2groups can each be replaced, independently of one another, by -O-, -S-, -NH-, NR x -, -CO-, -COO-, -OCO-, -OCOO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C- in such a way that O and / or S atoms are not linked directly to one another, a polymerisable group or a cycloalkyl or aryl group having up to 20 C atoms which can optionally be mono- or poly-substituted by halogen, preferably F, or by a polymerisable group,

[0529] x 1 and x 2 each, independently of one another, 0, 1 or 2,

[0530] y1 and y 2 each, independently of one another, is 0, 1, 2, 3 or 4,

[0531] B 1 and B 2 each, independently of one another, is an aromatic or partially or completely saturated aliphatic six-membered ring, wherein one or more CH groups can each be replaced by N and one or more non-adjacent CH2 groups can each be replaced by O or S,

[0532] W 1 and W 2 each, independently of one another, is -Z 1 -A 1 -(Z 2 -A 2 ) m -R, and one of the two is alternatively R 1 or A 3 but not both are H, or

[0533] is

[0534]

[0535] U 1 and U 2 each, independently of one another, is CH2, O, S, CO or CS,

[0536] V 1 and V 2 each, independently of one another, is (CH2) n wherein one to four non-adjacent CH2 groups can each be replaced by O or S, and V 1 and V 2 one of the two is in

[0537] is

[0538] both are single bonds,

[0539] n is 1, 2 or 3

[0540] Z 1 and Z 2 each, independently of one another, is -O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR x -, -NR x-CO-, -O-CH2-, -CH2-O-, -S-CH2-, -CH2-S-, -CF2-O-, -O-CF2-, -CF2-S-, -S-CF2-, -CH2-CH2-, -CF2-CH2-, -CH2-CF2-, -CF2-CF2-, -CH=N-, -N=CH-, -N=N-, -CH=CH-, -CF=CH-, -CH=CF-, -CF=CF-, -C≡C-, a combination of two of these groups, wherein no two O and / or S and / or N atoms are bound directly to each other, preferably -CH=CH-COO- or -COO-CH=CH- or a single bond,

[0541] R x represents alkyl having 1 to 6 C atoms,

[0542] A 1 , A 2 and A 3 are each, independently of one another, 1,4-phenylene, wherein one or two non-adjacent CH groups can each be replaced by N; 1,4-cyclohexylene, wherein one or two non-adjacent CH2groups can each be replaced by O or S; 1,3-dioxolan-4,5-diyl, 1,4-cyclohexenylene, 1,4-bicyclo[2.2.2]octylene, piperidin-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein each of these groups can be mono- or poly-substituted by L, and additionally A 1 may be a single bond,

[0543] L is a halogen atom, preferably F, CN, NO2, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl or alkoxycarbonyloxy having 1 to 7 carbon atoms, wherein one or more H atoms can each be replaced by F or Cl,

[0544] m is in each case independently 0, 1, 2 or 3, and

[0545] R and R 1 are each, independently of one another, H, F, Cl, Br, I, CN, SCN, SF5, straight-chain or branched alkyl having 1 or 3 to 25 carbon atoms which can optionally be mono- or poly-substituted by F, Cl, Br, I or CN, and wherein one or more non-adjacent CH2groups can each be replaced by -O-, -S-, -NH-, -NR 0 -, -CO-, -COO-, -OCO-, -O-COO-, -S-CO-, -CO-S-, -CH=CH- or -C≡C-, wherein no two O and / or S atoms are bound directly to each other; or a polymerisable group.

[0546] Especially preferred are chiral binaphthyl derivatives of formula A-VI-1

[0547]

[0548] wherein ring B, R 0 and Z 0 as defined for formula A-IV and A-V, and b is 0, 1, or 2,

[0549] in particular those selected from the group consisting of the following formulae A-VI-1a to A-VI-1c:

[0550]

[0551]

[0552] wherein ring B, R 0 and Z 0 as defined for formula A-VI-1, and

[0553] R 0 as defined for formula A-IV, or H or alkyl having 1 to 4 carbon atoms, and

[0554] b is 0, 1 or 2,

[0555] and Z 0 in particular -OC(O)- or a single bond.

[0556] The concentration of the one or more chiral dopants in the LC medium is preferably in the range of 0.001 % to 20 %, preferably 0.05 % to 5 %, more preferably 0.1 % to 2 %, and most preferably 0.5 % to 1.5 %. These preferred concentration ranges are particularly suitable for the chiral dopants S-4011 or R-4011 (both from Merck KGaA) and chiral dopants having the same or similar HTP. For chiral dopants having a higher or lower absolute value of the HTP compared to S-4011, these preferred concentrations have to be decreased or increased proportionally to their HTP value relative to S-4011.

[0557] The pitch p of the LC medium or host mixture according to the present application is preferably in the range of 5 to 50 pm, more preferably 8 to 30 pm and particularly preferably 10 to 20 pm.

[0558] Preferably, the medium according to the present application comprises a stabilizer selected from the group consisting of compounds of formulae ST-1 to ST-19.

[0559]

[0560]

[0561]

[0562]

[0563] wherein

[0564] R ST represents H, alkyl or alkoxy having 1 to 15 C atoms, wherein in addition one or more CH2groups in these radicals can each be replaced, independently of one another, by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, -O-CO- in such a way that O atoms are not directly linked to one another, and in which, in addition, one or more H atoms can be replaced by halogen, -O-, -CO-O-, -O-CO- in such a way that O atoms are not directly linked to one another, and in which, in addition, one or more H atoms can be replaced by halogen,

[0565] represents

[0566]

[0567] Z ST each, independently of one another, represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond,

[0568] L 1 and L 2 each, independently of one another, represents F, Cl, CF3or CHF2,

[0569] p represents 1 or 2,

[0570] q represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0571] In the compounds of the formula ST, particular preference is given to compounds of the formula

[0572]

[0573]

[0574] wherein n = 1, 2, 3, 4, 5, 6 or 7, preferably n = 1 or 7

[0575]

[0576] wherein n = 1, 2, 3, 4, 5, 6 or 7, preferably n = 3

[0577]

[0578] wherein n = 1, 2, 3, 4, 5, 6 or 7, preferably n = 3

[0579]

[0580]

[0581] In the compounds of formula ST-3a and ST-3b, n preferably denotes 3. In the compounds of formula ST-2a, n preferably denotes 7.

[0582] Very particularly preferred mixtures according to the application comprise one or more stabilizers selected from the group of compounds of formulae ST-2a-1, ST-3a-1, ST-3b-1, ST-8-1, ST-9-1 and ST-12:

[0583]

[0584]

[0585] Based on the mixture, the compounds of formulae ST-1 to ST-19 are preferably each present in the liquid-crystalline mixture according to the application in an amount of 0.005 to 0.5%.

[0586] If the mixture according to the application comprises two or more compounds of formulae ST-1 to ST-18, the concentration increases correspondingly to 0.01 to 1% in the case of two compounds, based on the mixture.

[0587] However, the total proportion of compounds of formulae ST-1 to ST-18 should not exceed 2%, based on the mixture according to the application.

[0588] The mixture according to the application preferably comprises

[0589] one or more compounds of formula I, preferably selected from the group of compounds of formulae I-1 to I-14, very preferably I-1 to I-5, preferably in a total concentration in the range of > 0% to 20%, more preferably 2% to 15% or 3% to 14%, particularly preferably 8% to 12%,

[0590] and / or

[0591] one or more compounds of formula IIA, preferably in a total concentration in the range of 3% to 25%, more preferably 6% to 20%, particularly preferably 8% to 15%;

[0592] and / or

[0593] - one or more compounds of the formulae IIA and IIB, preferably in a total concentration in the range from 5 to 30 %, more preferably from 8 to 25 %, particularly preferably from 10 to 20 %;

[0594] and / or

[0595] - one or more compounds of the formulae I and IV, preferably in a total concentration in the range from 35 to 75 %, more preferably from 40 to 65 %, particularly preferably from 45 to 55 %;

[0596] and / or

[0597] - one or more compounds of the formulae I and IV and IVb, preferably in a total concentration in the range from 35 to 70 %, more preferably from 40 to 65 %, particularly preferably from 45 to 60 %;

[0598] and / or

[0599] - one or more compounds of the formulae IIA and / or IIB and III, preferably III-2 and / or III-3, preferably in a total concentration in the range from 10 to 40 %, more preferably from 12 to 35 %, particularly preferably from 15 to 30 %.

[0600] In particular, the medium comprises

[0601] - one or more compounds of the formula CY-n-Om, in particular CY-3-O4, CY-5-O4 and / or CY-3-O2, preferably in a total concentration in the range from 1 to 20 %, preferably from 2 to 15 %, very preferably from 3 to 10 % or from 3 to 8 %;

[0602] and / or

[0603] - CPY-n-Om, in particular CPY-2-O2, CPY-3-O2 and / or CPY-5-O2, preferably in a concentration of > 5 %, in particular from 7 to 20 %,

[0604] and / or

[0605] - one or more compounds of the formula CCY-n-Om, preferably CCY-4-O2, CCY-3-O2, CCY-3-O3, CCY-3-O1 and / or CCY-5-O2, preferably in a concentration of > 3 %, in particular from 5 to 15 %,

[0606] and / or

[0607] - CLY-n-Om, preferably CLY-2-O4, CLY-3-O2 and / or CLY-3-O3, preferably in a concentration of > 5 %, in particular from 15 to 30 %, very preferably from 20 to 25 %, based on the entire mixture;

[0608] and / or

[0609] - CLY-n-Om and CY-n-Om, preferably in a concentration of 10 to 80 %, based on the mixture as a whole,

[0610] and / or

[0611] - CLY-n-Om and PY-n-Om, preferably CLY-3-O2 and / or CLY-3-O3 and / or CLY-4-O2 and PY-3-O2 and / or PY-1-O2, preferably in a concentration of 5 to 35 %, more preferably 15 to 33 %, based on the mixture as a whole,

[0612] and / or

[0613] and / or

[0614] - CC-V-V, preferably in a concentration of 5 to 50 %, based on the mixture as a whole.

[0615] and / or

[0616] - compounds of formulae CC-3-V1 and / or CC-4-V1 in a total concentration in the range of 5 to 40 %, more preferably 15 to 35 %, particularly preferably 20 to 30 %,

[0617] and / or

[0618] - one or more compounds of formula B-nO-Om and / or B(S)-nO-Om, in particular compound B(S)-2O-O5, preferably in a concentration in the range of 2 to 10 %, and compounds CC-3-V1 and / or compounds CC-4-V1 in a total concentration in the range of 10 to 30 %, preferably 15 to 20 %.

[0619] and / or

[0620] - 0.1 % to 3 % of compound PPGU-3-F

[0621] and / or

[0622] -> 0 % to 10 % of compound PGIY-nO-Om.

[0623] Furthermore, the present application relates to an electro-optical display with active matrix addressing, characterized in that as dielectric it contains a liquid-crystalline medium as described above and in that the display is a VA, SA-VA, IPS, U-IPS, FFS, UB-FFS, SA-FFS, PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-positively-VA, PS-TN, polymer stabilised SA-VA or polymer stabilised SA-FFS display.

[0624] With regard to the liquid crystal medium according to the invention, it is advantageous to have a nematic phase with a temperature of ≤-20°C to ≥70°C, particularly preferably ≤-30°C to ≥80°C, and very particularly preferably ≤-40°C to ≥90°C.

[0625] The medium according to the invention has a clearing temperature of 70°C or higher, preferably 74°C or higher.

[0626] The phrase "possessing a nematic phase" here means, on the one hand, that no smectic phase or crystallization was observed at the corresponding temperature at low temperatures, and on the other hand, that the nematic phase did not become clear upon heating. Low-temperature studies were conducted in a flow viscometer at the corresponding temperature and verified by storage for at least 100 hours in a test chamber with a layer thickness corresponding to the electro-optic application. If the storage stability in the corresponding test chamber at -20°C is 1000 hours or more, the medium is said to be stable at that temperature. The response times were 500 hours and 250 hours at -30°C and -40°C, respectively. At high temperatures, the clearing point was measured in a capillary using conventional methods.

[0627] The liquid crystal mixture preferably has a nematic phase range of at least 60K and a maximum thickness of 30mm at 20°C. 2 ·s -1 Flow viscosity ν 20 .

[0628] The mixture is nematic at temperatures of -20°C or lower, preferably -30°C or lower, and very preferably -40°C or lower.

[0629] The birefringence value Δn in the liquid crystal mixture is typically between 0.07 and 0.16, preferably between 0.08 and 0.15, and very preferably between 0.09 and 0.14.

[0630] In a preferred embodiment of the invention, the medium has a birefringence in the range of 0.085 to 0.105, preferably 0.090 to 0.100, and particularly 0.092 to 0.094.

[0631] The liquid crystal mixture according to the invention has a dielectric anisotropy Δε of -1.5 to -8.0, preferably -3.0 to -5.0, and particularly -3.5 to -4.5.

[0632] The rotational viscosity γ1 at 20°C is preferably ≤160 mPa·s, especially ≤130 mPa·s.

[0633] The medium according to the invention has a mean elastic constant K of 15 or greater, preferably 15.3 or greater, very preferably 15.4 or greater, and particularly 15.5 or 15.6 or greater. avg .

[0634] The value γ1 / K1 of the medium according to the present application is 7.9 or 7.8 or 7.7 or 7.6 or less, preferably 7.0 or less, more preferably 6.9 or less, in particular 6.8 or less.

[0635] Furthermore, the liquid-crystalline medium according to the present application has a high value of the voltage holding ratio in a liquid-crystalline cell.

[0636] Generally, liquid-crystalline media with low addressing voltage or threshold voltage exhibit lower voltage holding ratios than those with higher addressing voltage or threshold voltage and vice versa.

[0637] For the present application, the term "dielectrically positive compounds" denotes compounds with Δε > 1.5, the term "dielectrically neutral compounds" denotes those with -1.5 < Δε < 1.5 and the term "dielectrically negative compounds" denotes those with Δε < -1.5. Here, the dielectric anisotropy of a compound is determined by dissolving 10% of the compound in a liquid-crystalline host and determining the capacitance of the resulting mixture in at least one test cell, in each case with a layer thickness of 20 μιη and with homeotropic and homogenous surface alignment at 1 kHz. The measurement voltage is generally 0.5 V to 1.0 V, but is always below the threshold of the capacitance of the respective liquid-crystalline mixture investigated.

[0638] All temperature values according to the present application are indicated in °C.

[0639] The mixtures according to the present application are suitable for all VA-TFT applications, such as, for example, VAN, MVA, (S)-PVA, ASV, PSA (polymer sustained VA) and PS-VA (polymer stabilized VA). They are furthermore suitable for IPS (in-plane switching) and FFS (fringe field switching) applications with negative Δε.

[0640] The nematic liquid-crystalline mixture in the display according to the present application generally comprises two components: A and B, which itself consists of one or more individual compounds.

[0641] Component A has a significantly negative dielectric anisotropy and imparts a dielectric anisotropy of the nematic phase of < -0.5. In addition to one or more compounds of the formula I, it preferably comprises compounds of the formulae IIA, MB and / or IIC, furthermore one or more compounds of the formula IV-1.

[0642] The proportion of component A is preferably 45 to 100%, in particular 60 to 85%.

[0643] For component A, one (or more) individual compound(s) with a value of Δε of < -0.8 is (are) preferably selected. The smaller the proportion of A in the overall mixture, the more negative this value must be.

[0644] Component B has a pronounced nematicity and a specific birefringence of not more than 30 mm-1 at 20°C.2 · s -1 preferably not more than 25 mm 2 · s -1 of flow viscosity.

[0645] A large number of suitable materials are known to the person skilled in the art from the literature. Particularly preferred are compounds of the formula O-17.

[0646] Particularly preferred individual compounds in component B are very low-viscosity nematic liquid crystals which have a flow viscosity of not more than 18 mm 2 · s -1 preferably not more than 12 mm 2 · s -1 of flow viscosity at 20°C.

[0647] Component B is a monotropic or a metastropic nematic phase which does not have a smectic phase and is able to prevent the occurrence of a smectic phase on cooling to very low temperatures in the liquid-crystalline mixture. If, for example, a number of highly nematic materials are added to a smectic liquid-crystalline mixture, the nematicity of these materials can be compared by the degree of inhibition of the smectic phase achieved.

[0648] The mixture can optionally also comprise a component C which comprises compounds having a dielectric anisotropy Δε > 1.5. These so-called positive compounds are usually present in mixtures of negative dielectric anisotropy in amounts of < 20% by weight of the mixture as a whole.

[0649] In addition to one or more compounds of the formula I, the medium preferably comprises 4 to 15, in particular 5 to 12 and especially preferably < 10 compounds of the formulae IIA, MB and / or IIC and optionally one or more compounds of the formula IV-1.

[0650] In addition to the compounds of the formula IB and the compounds of the formulae IIA, MB and / or IIC and optionally IV-1, the further constituents can be present, for example, in amounts of up to 45%, but preferably up to 35%, in particular up to 10%, of the mixture as a whole.

[0651] The further constituents are preferably selected from nematic or nematogenic substances, in particular from the following classes of known substances: azoxybenzene, benzanilide, biphenyl, terphenyl, benzoic acid phenyl ester or benzoic acid cyclohexyl ester, cyclohexanecarboxylic acid phenyl ester or cyclohexanecarboxylic acid cyclohexyl ester, phenylcyclohexane, cyclohexylbiphenyl, cyclohexylcyclohexane, cyclohexylnaphthalene, 1,4- bis(cyclohexyl)biphenyl or cyclohexylpyrimidine, phenyldioxane or cyclohexyldioxane, optionally halogenated benzylphenyl ether, diphenylacetylene and substituted cinnamate.

[0652] The most important compounds suitable as constituents of liquid-crystalline phases of this type can be characterized by the following formula IV

[0653] R 20 -L-G-E-R 21 IV

[0654] wherein L and E each denote a carbocyclic or heterocyclic ring system from the group formed by 1,4-disubstituted benzene and cyclohexane rings, 4,4'-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, dihydronaphthalene and tetrahydronaphthalene, quinazoline and tetrahydroquinazoline,

[0655] G represents -CH=CH- -N(O)=N-

[0656] -CH=CQ- -CH=N(O)-

[0657] -C≡C- -CH2-CH2-

[0658] -CO-O- -CH2-O-

[0659] -CO-S- -CH2-S-

[0660] -CH=N- -COO-Phe-COO-

[0661] -CF2O- -CF=CF-

[0662] -OCF2- -OCH2-

[0663] -(CH2)4- -(CH2)3O-

[0664] or a C-C single bond, Q denotes halogen, preferably chlorine or -CN, and R 20 and R 21 each denote alkyl, alkenyl, alkoxy, alkoxyalkyl or alkoxycarbonyloxy having up to 18, preferably up to 8 carbon atoms, or one of these groups denotes CN, NC, NO2, NCS, CF3, SF5, OCF3, F, Cl or Br.

[0665] In most of these compounds, R 20 and R 21 differ from one another, one of these groups is usually alkyl or alkoxy. Other variations of the proposed substituents are also common. Many such substances or mixtures thereof are also commercially available. All these substances can be prepared by methods known from the literature.

[0666] It is self-evident to the person skilled in the art that the VA, IPS or FFS mixtures according to the application can also comprise compounds in which, for example, H, N, O, Cl and F are replaced by the corresponding isotopes.

[0667] The compounds of the formula P are optionally added to the mixtures according to the application in a concentration of preferably 0.01 to 5 % by weight, particularly preferably 0.2 to 2 % by weight. These mixtures can also optionally comprise an initiator, as described for example in U.S. 6,781,665. An initiator (for example Irganox-1076 from BASF) is preferably added to the mixture comprising the polymerisable compounds in an amount of 0 % to 1 %. Mixtures of this type can be used in the so-called Polymer Stabilized VA mode (PS-VA) or PSA (Polymer Sustaining VA), in which after filling the display panel, polymerization of the reactive mesogen is intended to take place in the liquid crystal mixture. The prerequisite for this is that the liquid crystalline compounds of the LC host do not react under the polymerization conditions of the reactive mesogen (i.e. typically upon exposure to UV in the wavelength range of 320 to 360 nm). Liquid crystalline compounds containing alkenyl side chains (such as for example CC-3-V) do not exhibit a reaction (UV polymerization) under the polymerization conditions for RMs, therefore, in this context, such compounds should not be regarded as RMs.

[0668] The compounds according to the application can be synthesized by or analogously to known methods described in the literature (for example in the standard works of organic chemistry, such as Houben-Weyl, Methoden der Organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart), under reaction conditions which are known and suitable for said reactions. Hereinafter, variants which are known per se, but are not mentioned here, can also be used. In particular, they can be prepared as described in the following reaction schemes or analogously thereto. Further methods for the preparation of the compounds according to the application can be derived from the examples.

[0669] Other mesogenic compounds not explicitly mentioned above can optionally and advantageously also be used in the media according to the application. Such compounds are known to the person skilled in the art. DETAILED DESCRIPTION

[0670] The following examples illustrate the application but do not limit the application. They show, however, the person skilled in the art preferred mixture concepts, as well as the compounds preferably used and their respective concentrations, as well as their combinations with one another. Furthermore, the examples clarify which properties and combinations of properties are obtainable.

[0671] For the present application and in the following examples, the structure of the liquid crystalline compounds is indicated by the abbreviations, which are converted into chemical formulae according to Tables A to C below. All groups C n H 2n+1 , C m H 2m+1 and Cl H 2l+1 or C n H 2n , C m H 2m and C l H 2l are straight-chain alkyl or alkylene groups, each having n, m and I C atoms in each case. Preferably, n, m and I are independently of each other 1, 2, 3, 4, 5, 6 or 7. Table A shows the codes for the ring elements of the compound nucleus, Table B lists the bridging units, and Table C lists the symbolic meaning of the left-hand and right-hand end groups. The abbreviations consist of the code for the ring element with optional linking groups, followed by a first hyphen and the code for the left-hand end group, and a second hyphen and the code for the right-hand end group. Table D shows exemplary structures of the compounds and their respective abbreviations.

[0672] Table A: Ring elements

[0673]

[0674]

[0675]

[0676] Table B: Bridging units

[0677]

[0678]

[0679] Table C: End groups

[0680]

[0681]

[0682] wherein n and m are each an integer, and the three dots "..." are a placeholder for further abbreviations from the table.

[0683] In addition to the compounds of the formulae I, IIA, IIB, IIC and / or IID, the mixtures according to the application preferably comprise one or more compounds of the following mentioned compounds.

[0684] The following abbreviations are used:

[0685] (n, m, k and I are each independently of one another an integer, preferably 1 to 9, preferably 1 to 7, k and I can also be 0 and are preferably 0 to 4, more preferably 0 or 2 and most preferably 2, n is preferably 1, 2, 3, 4 or 5, in the combination "-nO-" it is preferably 1, 2, 3 or 4, preferably 2 or 4, m is preferably 1, 2, 3, 4 or 5, in the combination "-Om" it is preferably 1, 2, 3 or 4, more preferably 2 or 4. The combination "-IVm" is preferably "2V1 ").

[0686] Table D

[0687]

[0688]

[0689]

[0690]

[0691]

[0692]

[0693]

[0694]

[0695]

[0696]

[0697]

[0698]

[0699]

[0700]

[0701]

[0702]

[0703]

[0704]

[0705] Table E

[0706] Table E shows chiral dopants which can be added to the LC medium according to the application.

[0707]

[0708]

[0709]

[0710]

[0711] Table F

[0712] Table F shows illustrative reactive mesogenic compounds which can be used in LC media according to the application.

[0713]

[0714]

[0715]

[0716]

[0717]

[0718]

[0719]

[0720]

[0721]

[0722]

[0723]

[0724]

[0725]

[0726]

[0727]

[0728]

[0729]

[0730]

[0731]

[0732]

[0733] In a preferred embodiment, the mixture according to the present application comprises one or more polymerisable compounds which are preferably selected from the group of polymerisable compounds of formulae RM-1 to RM-144. Of 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, RM-122 and RM-145 to RM-152 are particularly preferred.

[0734] In another preferred embodiment, the mixture according to the present application comprises one or more polymerisable compounds selected from the group of formulae RM-145 to RM-152, very preferably of formulae RM-147 to RM-152.

[0735] Table G

[0736] Table G exhibits self-aligning additives for vertical alignment which can be used in LC media together with polymerisable compounds of formula P for SA-VA and SA-FFS displays according to the present application:

[0737]

[0738]

[0739]

[0740]

[0741]

[0742]

[0743]

[0744]

[0745]

[0746]

[0747]

[0748] In a preferred embodiment, the LC medium according to the present application, SA-VA and SA-FFS displays comprise one or more SA-additives selected from formulae SA-1 to SA-48, preferably from formulae SA-14 to SA-48, very preferably from formulae SA-20 to SA-34 and SA-44 in combination with one or more RMs of formula P.

[0749] Working examples:

[0750] The following examples are intended to explain the present application without limiting it. In the examples, m.p. means melting point and C means clearing point of the liquid crystalline substance in degrees Celsius; boiling point is indicated as m.p.. Further: C means crystalline solid state, S means smectic phase (index indicates the phase type), N means nematic phase, Ch means cholesteric phase, I means isotropic phase, T g The number between two symbols indicates the transition temperature in degrees Celsius.

[0751] The host mixture for determining the optical anisotropy Δn of a single compound is the commercial mixture ZLI-4792 (Merck KGaA). The dielectric anisotropy Δε is determined using the commercial mixture ZLI-2857. The physical data of the compound to be investigated are obtained from the change of the dielectric constant of the host mixture after addition of the compound to be investigated and extrapolated to 100% of the used compound. Usually, 10% of the compound to be investigated are dissolved in the host mixture depending on the solubility.

[0752] Unless otherwise indicated, parts or percentages data represent parts by weight or weight percentages. In the context:

[0753] V o represents the threshold voltage at 20°C, the capacitance [V],

[0754] n e represents the extraordinary refractive index at 20°C and 589 nm,

[0755] n o represents the ordinary refractive index at 20°C and 589 nm,

[0756] Δn represents the optical anisotropy at 20°C and 589 nm,

[0757] ε ⊥ represents the dielectric constant perpendicular to the director at 20°C and 1 kHz,

[0758] ε || represents the dielectric constant parallel to the director at 20°C and 1 kHz,

[0759] Δε represents the dielectric anisotropy at 20°C and 1 kHz,

[0760] cl.p., T(N, I) denotes clearing point [°C],

[0761] γ1 denotes the rotational viscosity [mPa-s] measured at 20°C,

[0762] K1 denotes the elastic constant, "splay" deformation [pN] at 20°C,

[0763] K2 denotes the elastic constant, "twist" deformation [pN] at 20°C,

[0764] K3 denotes the elastic constant, "bend" deformation [pN] at 20°C,

[0765] K avg. denotes the average elastic constant defined as

[0766] LTS denotes the low temperature stability (nematic phase) measured as specified in the test cell or in the bulk,

[0767] All temperature values indicated in this application, such as melting point T(C,N), the transition from smectic phase (S) to nematic phase (N) T(S,N) and clearing point T(N,I) or cl.p., are expressed in degrees Celsius (°C), unless otherwise specified. M.p. denotes melting point. Furthermore, Tg = glassy, C = liquid crystalline, N = nematic, S = smectic and I = isotropic. The numbers between these symbols indicate the transition temperatures.

[0768] The term "threshold voltage" used in this application relates to the capacitive threshold (V0), which is also called Freedericksz threshold, unless otherwise specified. In the examples, the optical threshold can also be indicated for a relative contrast of 10% (V 10 ) as usual.

[0769] The display used for measuring the capacitive threshold voltage consists of two plane-parallel glass outer plates spaced by 20 μm, each having an electrode layer on the inner side and on top an un-rubbed polyimide alignment layer, which leads to a homeotropic edge alignment of the liquid crystal molecules.

[0770] The display or test cell used for measuring the tilt angle consists of two plane-parallel glass outer plates spaced by 4 μm, each having an electrode layer on the inner side and on top a polyimide alignment layer, wherein the two polyimide layers are rubbed antiparallel to each other and lead to a homeotropic edge alignment of the liquid crystal molecules.

[0771] ​The VHR is determined in a commercially available instrument model LCM-1 (O0004) from Japan TOYO Corporation at 20°C (VHR 20 ) and in an oven at 100°C (VHR 100 ) after 5 minutes, unless indicated otherwise. The voltage used has a frequency ranging from 1 Hz to 60 Hz, unless indicated more precisely.

[0772] The precision of the VHR measurement depends on the respective VHR value. The precision decreases with decreasing values. Deviations observed in the case of values in various amplitude ranges are summarized in the following table in their order of magnitude.

[0773]

[0774] The stability against UV irradiation is investigated in a commercially available instrument "Suntest CPS (Suntest CPS+)" from Heraeus, Germany, using a xenon lamp NXE1500B. Unless explicitly indicated, the sealed test boxes are irradiated for 2.0 hours without additional heating. The irradiation power in the wavelength range from 300 nm to 800 nm is 765 W / m 2 V. A UV "cut-off" filter with an edge wavelength of 310 nm is used in order to mimic a so-called window glass mode. In each series of experiments, at least four test boxes are investigated for each condition, and the individual results are indicated as average values corresponding to each measurement.

[0775] The reduction of the voltage holding ratio (AVHR) typically caused by exposure (e.g. by UV irradiation or by LCD backlighting) is determined according to the following equation (1):

[0776] AVHR(t) = VHR(t) - VHR(t=0) (1).

[0777] To investigate the low temperature stability, also called "LTS", i.e. the stability of the LC mixture against the occurrence of spontaneous crystallization or smectic phase of the individual components at low temperatures in the bulk, several sealed bottles each containing about 1 g of material are stored at one or more given temperatures, typically -10°C, -20°C, -30°C and / or -40°C, and visually inspected at regular intervals whether a phase change is observed. As soon as the first one of the samples shows a change at the given temperature, the time is noted. The time until the last inspection at which no change is observed is noted as the respective LTS.

[0778] The ion density was measured using a commercially available LC material characterization system model 6254 from Japan Toyo Corporation using a VHR test cell with a cell gap of 3.2 pm of AL16301 polyimide (Japan JSR Corp.) from which the resistivity was calculated. The measurements were performed after storage in an oven at 60 °C or 100 °C for 5 min.

[0779] By so-called “HTP” is meant the helical twisting power (in pm) of an optically active or chiral substance in an LC medium. Unless indicated otherwise, the HTP is measured in the commercially available nematic LC host mixture MLD-6260 (Merck KGaA) at a temperature of 20 °C.

[0780] Clearing point was measured using a Mettler Thermosystem FP900. Optical anisotropy (An) was measured using an Abbe-Refraktometer H005 (sodium spectral lamp Na 10 at 589 nm, 20 °C). Dielectric anisotropy (De) was measured using an LCR-Meter E4980A / Agilent (G005) at 20 °C (e-parallel cell with JALS2096-R1). Switching voltage (Vo) was measured using an LCR-Meter E4980A / Agilent (G005) at 20 °C (e-parallel cell with JALS2096-R1). Rotational viscosity (Y1) was measured using a TOYO LCM-2 (0002) at 20 °C (Y1 negative cell with JALS-2096-R1). Elastic constant (K1, splay) was measured using an LCR-Meter E4980A / Agilent (G005) at 20 °C (e-parallel cell with JALS2096-R1). K3: Elastic constant (K3, bend) was measured using an LCR-Meter E4980A / Agilent (G005) at 20 °C (e-parallel cell with JALS2096-R1).

[0781] All concentrations in this application are indicated as weight percent, and relate to the corresponding mixture as a whole (without solvents) comprising all solid or liquid crystal components, unless explicitly mentioned otherwise. All physical properties were determined according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status November 1997, Merck KGaA, Germany, and apply to a temperature of 20 °C, unless explicitly indicated otherwise.

[0782] The following mixture examples with negative dielectric anisotropy are especially suitable for liquid-crystalline displays having at least one planar alignment layer, such as for example IPS and FFS displays, especially UB-FFS (= Ultra Bright FFS), and for VA displays.

[0783] Mixture examples and comparative examples

[0784] The comparative mixtures C-1 and C-2, and the mixture examples N-1 to N-65 have the compositions and properties given in the following tables.

[0785] Comparative mixture C1

[0786]

[0787]

[0788] Comparative mixture C2

[0789]

[0790] Mixture N1

[0791]

[0792]

[0793] Table 1

[0794] Mixture [gamma]1 / K1 K avg ]]> C-1 7.5 15.7 C-2 7.2 15.6 N-1 6.8 15.8

[0795] The comparative examples C-1 and C-2 are very similar to mixture N-1 in terms of composition, clearing temperature, dielectric anisotropy and birefringence, but do not contain a compound of formula I. The comparison of mixture example N-1 with C-1 and C-2 surprisingly shows that the liquid-crystalline medium according to the application has a significantly improved (lower) value of γ1 / K1 due to the use of a compound of formula I, which leads to a faster switching of the display comprising the medium (Table 1). Furthermore, the value of K avg does not change practically, even increases, which corresponds to an unchanged high contrast.

[0796] Mixture N2

[0797]

[0798] Mixture N3

[0799]

[0800] Mixture N4

[0801]

[0802]

[0803] The following mixtures N-5 to N-40 also contain the above-mentioned stabilizer. The amounts of host mixture and of stabilizer given in the table add up to 100% by weight.

[0804] Table 1 : Mixtures containing a stabilizer.

[0805]

[0806]

[0807] The chiral nematic mixture N-41 consists of 99.20% of the mixture N-5 and 0.80% of the chiral dopant S-2011 :

[0808]

[0809] The mixture N-41 is characterized by a very high stability under UV load and shows an improved switching time.

[0810] Mixture N42

[0811]

[0812] Mixture N43

[0813]

[0814]

[0815] Mixture N44

[0816]

[0817] Mixture N45

[0818]

[0819]

[0820] Mixture N46

[0821]

[0822]

[0823] Mixture N47

[0824]

[0825] Mixture N48

[0826]

[0827]

[0828] Mixture N49

[0829]

[0830] Mixture N50

[0831]

[0832]

[0833] Mixture N51

[0834]

[0835] Mixture N52

[0836]

[0837]

[0838] Mixture N53

[0839]

[0840]

[0841] Mixture N54

[0842]

[0843] Mixture N55

[0844]

[0845]

[0846] Mixture N56

[0847]

[0848] Mixture N57

[0849]

[0850] Mixture N58

[0851]

[0852]

[0853] Mixture N59

[0854]

[0855]

[0856] Mixture N60

[0857]

[0858] Mixture N61

[0859]

[0860]

[0861] Mixture N62

[0862]

[0863]

[0864] Mixture N63

[0865]

[0866] Mixture N64

[0867]

[0868]

[0869] Mixture N65

[0870]

Claims

1. A liquid crystal medium comprising 2% to 15% of one or more compounds of formula I. in R 1 H represents a straight-chain or branched alkyl or alkoxy group having 1 to 15 carbon atoms, wherein one or more CH2 groups in these groups can be independently separated from each other. -C≡C-, -CF₂O-, -OCF₂-, -CH=CH-, -O-, -CO-O-, or -O-CO- are substituted in such a way that the O atoms are not directly connected to each other, and in addition, one or more H atoms may be substituted with halogens. express And n is 1, Y 1 Indicates H or CH3, v is 1, 2, 3, 4, 5, or 6; and One or more compounds selected from compounds of formulas IIA, IIB, IIC, and IID. in R 2A ,R 2B ,R 2C and R 2D Each group independently represents H, an alkyl or alkenyl group having up to 15 carbon atoms, which is unsubstituted, monosubstituted with CN or CF3, or at least monosubstituted with a halogen, wherein one or more CH2 groups in these groups may be -O-, -S-, -C≡C-, -CF₂O-, -OCF₂-, -OC-O-, or -O-CO- can be used to replace O atoms in a way that prevents them from being directly connected to each other. L 1 To L 4 Each can be represented independently as F, Cl, CF3, or CHF2. Y represents H, F, Cl, CF3, CHF2, or CH3. Z 2 Z 2B and Z 2D Each of these independently represents a single bond: -CH2CH2-, -CH=CH-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, -CF=CF-, or -CH=CHCH2O-. p represents 0, 1, or 2. q represents 0 or 1, and v represents an integer from 1 to 6. Compounds of formula I are excluded from formula IID. The medium contains one or more compounds of formula IV. in R 41 This indicates an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms, and R 42 This indicates an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms. The total concentration of compounds in formulas I and IV ranges from 35% to 75%. The dielectric anisotropy of this medium is -3.5 to -8.

0. The birefringence of this medium is 0.085 to 0.

105.

2. The medium of claim 1, wherein the medium comprises one or more compounds of formula III. in R 11 and R 12 Each of these groups independently represents H, and is an alkyl or alkoxy group having 1-15 carbon atoms, wherein one or more CH2 groups in these groups can be independently represented by H. -C≡C-, -CF₂O-, -OCF₂-, -CH=CH-, are replaced by -O-, -CO-O-, or -O-CO- in such a way that the O atoms are not directly connected to each other, and in addition, one or more H atoms may be replaced by halogens. A 1 Each occurrence is represented independently. a) 1,4-cyclohexeneyl or 1,4-cyclohexeneyl, wherein one or both non-adjacent CH2 groups may be replaced by -O- or -S-. b) 1,4-Phenylidene, wherein one or both CH groups may be replaced by N, or c) Selected from the following groups: spiro[3.3]heptane-2,6-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl. Groups a), b), and c) can be mono- or poly-substituted with halogen atoms. n is 0, 1, or 2. Z 1 Each occurrence independently represents -CO-O-, -O-CO-, -CF2O-, -OCF2-, -CH2O-, -OCH2-, -CH2-, -CH2CH2-, -(CH2)4-, -CH=CH-CH2O-, -C2F4-, -CH2CF2-, -CF2CH2-, -CF=CF-, -CH=CF-, -CF=CH-, -CH=CH-, -C≡C- or a single bond, and L 11 and L 12 Each of these independently represents F, Cl, CF3 or CHF2, and W represents O or S.

3. The medium according to claim 2, wherein W represents S in formula III.

4. The medium according to claim 1 or 2, wherein the medium comprises one or more compounds of formula III-3. in R 11 R 12 The same or different representations of H, alkyl or alkoxy groups having 1-15 C atoms, wherein one or more CH2 groups among these groups are optionally, independently of each other, represented by -C≡C-, -CF2O-, -OCF2-, -CH=CH-, -O-, -CO-O-, or -O-CO- are used to replace the O atoms in a manner that prevents them from being directly connected to each other, and one or more H atoms may be replaced by halogens.

5. The medium according to claim 1 or 2, wherein the medium comprises one or more compounds selected from the following formula:

6. The medium according to claim 1 or 2, wherein the medium comprises one or more compounds of formula V. in R 51 R 52 This indicates an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, or an alkoxyalkyl group having 2 to 7 carbon atoms, an alkenyl group, or an alkenyloxy group. Same or different Z 51 Z 52 Each of these can be independently represented as -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or a single bond, and n is 1 or 2.

7. The medium according to claim 1 or 2, wherein the medium comprises a chiral dopant.

8. The medium according to claim 1 or 2, wherein the medium comprises one or more polymerizable compounds of formula P. P-Sp-A 1 -(Z 1 -A 2 ) z -R P in P represents a polymerizable group. Sp represents a spacer group or a single bond. A 1 A 2 The same or different groups may represent aromatic, heteroaromatic, alicyclic, or heterocyclic groups, and may also contain fused rings, which may be unsubstituted or mono- or polysubstituted with L. L represents F, Cl, -CN, P-Sp- or a straight-chain, branched or cyclic alkyl group having 1-25 C atoms, wherein one or more non-adjacent CH2- groups are optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-, -O-CO-O- such that the O- and / or S- atoms are not directly connected to each other, and one or more H atoms are each optionally replaced by P-Sp-, F or Cl. Z 1 Represents -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -(CH2) n1 -, -CF2CH2-, -CH2CF2-, -(CF2) n1 -, -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH-, -CH2-CH2-CO-O-, -O-CO-CH2-CH2-, -CR 0 R 00 - or single key, R 0 R 00 The same or different representations of H or alkyl groups having 1-12 carbon atoms, R represents H, L, or P-Sp-, z is 0, 1, 2, or 3. n1 can be 1, 2, 3, or 4.

9. The medium according to claim 8, wherein A 1 A 2 The same or different refer to aromatic, heteroaromatic, alicyclic or heterocyclic groups having 4 to 25 ring atoms.

10. The medium according to claim 8, wherein the polymerizable compound of formula P is polymerized.

11. A method for preparing an LC medium according to any one of claims 1-10, comprising the following steps: The compound of one or more of the formula I according to claim 1 is mixed with one or more compounds selected from the formulas IIA, IIB, IIC and IID, and optionally with one or more mesocrystalline or liquid crystal compounds and / or with polymerizable compounds according to claim 8 or 9, and optionally with one or more additives.

12. An LC display comprising a medium according to any one of claims 1-10.

13. The display of claim 12, wherein the display is a PSA display.

14. The display of claim 13, wherein the display is a PS-VA, PS-IPS, PS-FFS, PS-UB-FFS, polymer-stabilized SA-VA, or polymer-stabilized SA-FFS display.

15. The display of claim 12, wherein the display is a VA, IPS, U-IPS, FFS, UB-FFS, SA-FFS, or SA-VA display.

16. Use of the liquid crystal medium according to any one of claims 1-10 in an electro-optical display.

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