KR102609821B1 - Liquid crystal medium - Google Patents

Abstract

The present invention relates to a liquid crystal (LC) medium comprising a polymerisable compound, a process for its preparation, in particular its use for optical, electro-optic and electronic purposes in LC displays, especially of the polymer maintained orientation (PSA) type, and It relates to LC displays, including PSA displays in particular.

Description

Liquid crystal medium {LIQUID CRYSTAL MEDIUM}

The present invention relates to a liquid crystal (LC) medium comprising a polymerisable compound, a process for its preparation, in particular its use for optical, electro-optic and electronic purposes in LC displays, especially of the polymer maintained orientation (PSA) type, and It relates to LC displays, including PSA displays in particular.

Liquid crystal displays (LC displays) currently used are typically of the TN (“twisted nematic”) type. However, they have the disadvantage of a strong viewing angle dependence of contrast.

Also known are so-called VA (“vertically oriented”) displays with wider viewing angles. The LC cell of a VA display contains a layer of LC medium between two transparent electrodes, where the LC medium typically has negative dielectric anisotropy. In the switched-off state, the molecules of the LC layer are either oriented perpendicularly (homeotropic) to the electrode surface, or have an inclined homeotropic orientation. Upon application of an electrical voltage to the two electrodes, reorientation of the LC molecules parallel to the electrode surfaces occurs.

Also known are OCB (“optically compensated bend”) displays, which are based on the birefringence effect and have an LC layer with a so-called “bend” orientation and typically positive dielectric anisotropy. Upon application of electrical voltage, reorientation of the LC molecules perpendicular to the electrode surface occurs. Additionally, OCB displays typically contain one or more birefringent optical retardation films to prevent undesirable light transmission of the bending cells in the dark state. OCB displays have wider viewing angles and shorter response times compared to TN displays.

The so-called IPS (“in-plane switching”), comprising an LC layer between two substrates, where the two electrodes are arranged only on one of the two substrates, preferably with a meshed comb-like structure. ") displays are also known. Upon application of voltage to the electrodes, an electric field develops between them with the main component parallel to the LC layer. This causes reorientation of LC molecules within the layer plane.

Additionally, so-called FFS (“fringe-field switching”) displays have been reported (in particular, SH Jung et al., Jpn. J. Appl. Phys., Volume 43 , No. 3, 2004 , 1028], which contains two electrodes on the same substrate, one of which is structured in a comb-like manner and the other electrode is unstructured. This results in a strong so-called “fringe field”, i.e. a strong electric field close to the edge of the electrode, and an electric field with both a strong vertical component and also a strong horizontal component throughout the cell. FFS displays have a low viewing angle dependence of contrast. FFS displays typically contain an LC medium with positive dielectric anisotropy, and an orientation layer, usually polyimide, which provides planar orientation for the molecules of the LC medium.

FFS displays can operate as active matrix or passive matrix displays. In the case of active matrix displays, individual pixels are typically addressed by integrated, non-linear active elements, such as transistors (e.g., thin film transistors (“TFTs”)), whereas passive matrix displays In the case of displays, individual pixels are typically addressed in a multiplex manner known from the prior art.

Additionally, an FFS display has been disclosed that has a similar electrode design and layer thickness as the FFS display, but includes a layer of LC medium with negative dielectric anisotropy instead of LC medium with positive dielectric anisotropy (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]. LC media with negative dielectric anisotropy exhibit more favorable director orientations with less tilt and stronger twist orientation compared to LC media with positive dielectric anisotropy, resulting in these displays having higher transmittance. The display further comprises an orientation layer, preferably of polyimide, provided on at least one of the substrates in contact with the LC medium, which induces a planar orientation of the LC molecules of the LC medium. These displays are also known as “ultra-brightness FFS (UB-FFS)” mode displays. These displays require highly reliable LC media.

The term "reliability" used below means the excellence of display performance over a period of time under different stress loads, such as light load, temperature, humidity, voltage, and display effects known to those skilled in the art of LC displays, such as Includes afterimages (plane and line afterimages), mura, yogore, etc. A standard parameter for classifying reliability is typically the voltage retention ratio (VHR) value, which is a measure of maintaining a constant electrical voltage in a test display. The higher the VHR value, the better the reliability of the LC medium.

In more recent types of VA displays, the uniform orientation of LC molecules is limited to a number of relatively small domains within the LC cell. Rotation may exist between these domains, also known as tilt domains. VA displays with tilt domains have greater viewing angle independence of contrast and grayscale compared to conventional VA displays. Additionally, this type of display is simpler to manufacture because no further treatment of the electrode surface for uniform orientation of the molecules in the switched-on state, for example by rubbing, is required. do. Instead, the preferred direction of tilt or pretilt angle is controlled by the specific design of the electrode.

In so-called MVA (“multidomain vertical orientation”) displays, this is typically achieved by electrodes having protrusions that cause local pretilt. As a result, LC molecules are oriented parallel to the electrode surface in different directions in different defined regions of the cell upon application of voltage. This achieves “controlled” switching and prevents the formation of interfering lines of rotation. This arrangement improves the viewing angle of the display, but also results in reduced light transmission. Further development of MVA uses protrusions only on one electrode side, while the opposite electrode has a slit, thereby improving light transmission. Electrodes with slits generate a non-homogeneous electric field in the LC cell upon application of voltage, meaning that controlled switching is still achieved. For further improvement of light transmission, the gap between the slit and the protrusion can be increased, but this ultimately results in a prolongation of the response time. In the so-called PVA (“patterned VA”) displays, the protrusions become completely unnecessary in that both electrodes are structured by opposing slits, which results in increased contrast and improved light transmission, but is technically difficult and the display is mechanically unstable. Becomes more sensitive to influences ("tapping", etc.). However, for many applications, such as monitors and especially TV screens, there is a need for shorter response times and improved contrast and brightness (transmittance) of displays.

A further development is the so-called PS (“polymer-retained”) or PSA (“polymer-retained orientation”) type of display, for which the term “polymer-stabilized” is also sometimes used. Here, small amounts (e.g. 0.3% by weight, typically <1% by weight) of one or more polymerisable compound(s), preferably polymerisable monomer compound(s), are added to the LC medium and the display of the LC medium After charging the furnace, they are polymerized or crosslinked in-situ, typically by UV photopolymerization, optionally while a voltage is applied to the electrodes of the display. Polymerization is carried out at the temperature at which the LC medium exhibits a liquid crystalline phase, typically room temperature. The addition of polymerisable mesogens or liquid crystalline compounds, also called reactive mesogens or “RMs”, to LC mixtures has proven particularly suitable.

Unless otherwise indicated, the term "PSA" is used hereinafter to refer to displays of the polymer maintained orientation type in general, and the term "PS" is used to refer to specific display modes such as PS-VA, PS-TN, etc.

Additionally, unless otherwise indicated, the term “RM” is used below to refer to polymerizable mesogens or liquid crystal compounds.

Meanwhile, the PS(A) principle is used in various common 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 RM occurs preferably in the presence of an applied voltage in the case of PS-VA and PS-OCB displays and with or without an applied voltage, preferably in the absence of an applied voltage in the case of PS-IPS displays. do. As can be demonstrated in the test cell, the PS(A) method results in a pretilt in the cell. For example, in the case of PS-OCB displays, it is possible to stabilize the bending structure so that the offset voltage is unnecessary or can be reduced. In the case of PS-VA displays, preslope has a positive effect on response time. For PS-VA displays, standard MVA or PVA pixel and electrode layouts can be used. However, it is also possible to use, for example, only one structured electrode without protrusions, which significantly simplifies the manufacture and at the same time results in very good contrast together with very good light transmission.

Additionally, the so-called posi-VA display (“positive VA”) has proven to be a particularly suitable mode. As with traditional VA displays, the initial orientation of the LC molecules in a posi-VA display is homeotropic, i.e., substantially perpendicular to the substrate in the initial state when no voltage is applied. However, unlike traditional VA displays, LC media with positive dielectric anisotropy are used in Posey-VA displays. As with commonly used IPS displays, the two electrodes in the Posey-VA display are arranged only on one of the two substrates, preferably exhibiting a meshed comb-like (alternating) structure. By application of a voltage to the alternating electrodes, which creates an electric field substantially parallel to the layer of LC medium, the LC molecules are transferred to an orientation substantially parallel to the substrate. Even in Posey-VA displays, polymer stabilization by addition of the RM polymerized in the display to the LC medium has proven to be advantageous, since a significant reduction in the switching time can be realized.

PS-VA displays are disclosed, 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 disclosed, for example, in Optics Express 2004, 12(7), 1221.

Like the conventional LC displays described above, PSA displays can operate as active matrix or passive matrix displays. In the case of active matrix displays, individual pixels are typically addressed by integrated, non-linear active elements, such as transistors (e.g., thin film transistors (“TFTs”)), whereas in the case of passive matrix displays, In , individual pixels are typically addressed in a multiplex manner known from the prior art.

PSA displays may also include an orientation layer that forms the display cells on either or both substrates. The orientation layer is typically in contact with the LC medium and applied to an electrode (if such an electrode exists) to induce the initial orientation of the LC molecules. The orientation layer may, for example, comprise or consist of polyimide, which may also be rubbed or produced by photo-alignment methods.

For monitor and especially TV applications in particular, optimization of the response time of LC displays, as well as contrast and luminance (and therefore also transmission) continues to be required. PSA methods can offer significant advantages here. In particular for the PS-VA, PS-IPS, PS-FFS and PS-Forge-VA displays, a reduction in the response time correlated with the measurable pretilt in the test cell can be achieved without significant adverse effects on other parameters.

According to the prior art, biphenyl diacrylate or dimethacrylate, optionally fluorinated, has been proposed as RM for use in PSA displays.

However, any combination of LC mixtures and one or more RMs, for example because an inadequate slope is set or not set at all, or because, for example, the so-called "voltage holding ratio" (VHR or HR) is inappropriate for TFT display applications. The problem is that it is not suitable for use with PSA displays. Additionally, it has been found that when used in PSA displays, the LC mixtures and RMs known from the prior art still have some disadvantages. Therefore, not all known RMs that are soluble in LC mixtures are suitable for use in PSA displays. Additionally, it is often difficult to find suitable selection criteria for RM other than direct measurement of pretilt in a PSA display. If it is desired to polymerize by UV light without the addition of photoinitiators, which may be advantageous for certain applications, the choice of suitable RMs becomes even narrower.

Additionally, the selected combination of LC host mixture/RM should have the lowest possible rotational viscosity and the best possible electrical properties. In particular, it should have the highest possible VHR. In PSA displays, a high VHR is especially necessary after UV light irradiation because UV exposure is not only an essential part of the display manufacturing process, but also occurs as a normal exposure during operation of the finished display.

In particular, it would be desirable to have new materials available for PSA displays that produce particularly small pretilt angles. Preferred materials herein are those which produce during polymerization for the same exposure time a pretilt angle that is smaller than hitherto known materials, and/or through their use, the (larger) pretilt angles achievable with the known materials can be achieved in a shorter period of time. These are already achievable after exposure time. Accordingly, the manufacturing time (“tact time”) of the display can be shortened and the manufacturing process cost can be reduced.

A further problem in PSA display manufacturing is the presence or removal of residual amounts of unpolymerized RM, especially after the polymerization step for creating the pretilt angle in the display. For example, unreacted RMs of this type may adversely affect the properties of the display, for example by polymerizing in an uncontrolled manner during operation after completion of the display.

Accordingly, PSA displays known from the prior art often exhibit the undesirable effect of so-called "afterimages" or "image burn", i.e. the image produced on an LC display by temporary addressing of individual pixels does not even appear on these pixels. remains visible after the electric field at is switched off or after other pixels are addressed.

Said “afterimages” may, on the one hand, occur if LC host mixtures with low VHR are used. The UV component of sunlight or backlighting can cause undesirable decomposition reactions of LC molecules, initiating the production of ionic or free-radical impurities. These may accumulate, particularly in the electrode or orientation layer, where they may reduce the effective applied voltage. This effect can also be observed in conventional LC displays without polymer components.

Additionally, an additional “afterimage” effect caused by the presence of non-polymerized RMs is often observed in PSA displays. Here, uncontrolled polymerization of the residual RM is initiated by UV light from the environment or backlighting. In a switched display area, this changes the tilt angle after several addressing cycles. As a result, a change in transmittance may occur in the switching region, while the transmittance remains unchanged in the non-switching region.

Accordingly, it is desirable to allow the polymerization of RMs to proceed as completely as possible during the manufacture of PSA displays, and to eliminate or reduce to a minimum the presence of unpolymerized RMs in the displays as much as possible. Therefore, there is a need for RM and LC mixtures that enable or assist a highly effective and complete polymerization of RM. Additionally, a controlled response of RM residual amount would be desirable. This would be simpler if RM polymerized faster and more efficiently than hitherto known compounds.

An additional issue observed during operation of PSA displays is the stability of the pretilt angle. Accordingly, it has been observed that the pretilt angle created during display manufacturing by polymerization of RM as described above does not remain constant and the display may deteriorate after being subjected to voltage stress during its operation. This may adversely affect display performance, for example by increasing black state transmittance and thereby reducing contrast.

Another problem to be solved is that prior art RMs often have high melting points and only limited solubility in many currently common LC mixtures, frequently showing a tendency to spontaneously crystallize from the mixture. Additionally, the risk of spontaneous polymerization precludes warming the LC host mixture to allow the polymerizable components to dissolve, meaning that the highest possible solubility, even at room temperature, is required. Additionally, there is a risk of separation (chromatographic effect), for example upon introduction of the LC medium into the LC display, which can significantly impair the homogeneity of the display. This is further increased by the fact that the LC medium is usually introduced at low temperatures to reduce the risk of spontaneous polymerization (see above), which in turn has a detrimental effect on solubility.

Another problem observed in the prior art is that the use of conventional LC media in LC displays, including but not limited to PSA type displays, is particularly problematic for display cells where the LC media is manufactured using the liquid crystal drop injection (ODF) method. When charging, it often induces the generation of mura in the display. This phenomenon is also known as “ODF mura”. Therefore, it is desirable to provide an LC medium that induces a reduction in ODF mura.

Another problem observed in the prior art is that LC media for use in PSA displays, including but not limited to PSA type displays, often exhibit high viscosity and, as a result, extended switching times. In order to reduce the viscosity and switching time of the LC medium, it has been proposed in the prior art to add LC compounds with alkenyl groups. However, LC media containing alkenyl compounds are often observed to exhibit a decrease in reliability and stability, and a decrease in VHR, especially after exposure to UV radiation. This is a significant disadvantage, especially when used in PSA displays, since photopolymerization of RMs in PSA displays is typically carried out by exposure to UV radiation, which can lead to a drop in VHR in the LC medium.

Accordingly, there still exists a significant need for PSA displays and LC media and polymerizable compounds for use in such displays that do not exhibit the disadvantages described above, or only to a small extent, and have improved properties.

In particular, it enables high resistivity and at the same time wide use-temperature range, short response time even at low temperatures, and low threshold voltage, small pretilt angle, multiple gray shades, high contrast and wide viewing angle, high reliability after UV exposure and high " There is a significant need for PSA displays and LC media and polymerizable compounds for use in such PSA displays that have voltage retention "(VHR) values and, in the case of polymerizable compounds, low melting points and high solubility in LC host mixtures. exists. In PSA displays for mobile applications, it is particularly desirable to have available LC media exhibiting low threshold voltage and high birefringence.

The present invention is based on the object of providing new suitable materials for use in PSA displays, especially RMs and LC media comprising them, which do not have the disadvantages indicated above or only to a reduced extent.

In particular, the present invention enables very high resistivity values, high VHR values, high reliability, low threshold voltage, short response time, high birefringence, shows good UV absorption especially at long wavelengths, and provides fast and complete absorption of RM contained therein. Allows polymerization, allows the creation of small pretilt angles as quickly as possible, allows high stability of the pretilt after long periods of time and/or after UV exposure, reduces or prevents the occurrence of "afterimages" in the display, and also It is based on the objective of providing an LC medium for use in PSA displays that reduces or prevents the occurrence of "ODF mura" in the display.

The above object is achieved according to the invention by means of the materials and methods described in the present application. Particularly surprisingly, as described below, RM of formula (I) is added to a host mixture containing an alkenyl compound of formula (AN) or AY, together with a quaterphenyl compound of formula (Q), and optionally a bicyclohexyl-phenyl compound of formula (C). When used, the above-mentioned beneficial effects have been found to be feasible.

It has also been observed that when using the polymerisable compound of formula (I) in the polymerizable component, it is possible to replace the terphenyl compound in the LC host mixture with only a small amount of the quarterphenyl compound of formula (Q). As a result, it is possible to reduce ODF mura while maintaining high UV absorption and enabling rapid and complete polymerization and strong tilt angle generation.

Additionally, for use in PSA displays with negative mode dielectrics, such as PS-VA, PS-IPS or PS-FFS, small amounts of compounds of formula Q and optionally formula C, which have positive dielectric anisotropy, can be added to form a negative dielectric anisotropy. By adding to the LC host mixture with dielectric constant ε _|| and ε _⊥ (dielectric constants in parallel and perpendicular directions to the long molecular axis of the LC molecule, respectively) values were observed to be possible. This allows, for example, a high dielectric constant ε _|| At the same time as achieving this value, the dielectric anisotropy Δε can be kept constant. This can reduce afterimages by reducing the kick-back voltage.

Therefore, the use of the LC medium according to the invention promotes a rapid and complete UV photopolymerization reaction, especially with UV of long wavelengths in the range 300-380 nm and especially above 340 nm, and leads to the rapid development of a large and stable pretilt angle, It reduces afterimages and ODF mura in displays, leads to high VHR values after UV photopolymerization, and also makes it possible to achieve fast response time, low threshold voltage and high birefringence.

The present invention relates to a liquid crystal (LC) medium comprising at least one compound of formula (I), at least one compound of formula (Q) and at least one compound selected from formulas AN and AY.

In the formula, the individual radicals have, identically or differently, on each occurrence, each independently of the other, the following meanings:

Sp ¹ , Sp ² spacer group or single bond,

P ¹ , P ² polymerizable group,

L P-Sp-, F, Cl, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C(=O)N(R ^x ) ₂ , -C(=O)Y ¹ , -C(=O)R ^x , -N(R ^x ) ₂ , optionally substituted silyl, optionally substituted aryl or heteroaryl with 5 to 20 ring atoms, or 1 to 25, particularly preferably 1 straight-chain or branched alkyl having to 10 C atoms (wherein also one or more non-adjacent CH ₂ groups are each independently of one another in such a way that the O and/or S atoms are not directly connected to each other -C(R ⁰ )=C(R ⁰⁰ )-, -C≡C-, -N(R ⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- may be replaced by, and one or more H atoms may also be replaced by F, Cl, CN, P- or P-Sp-),

^R _{_} is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms are each replaced by F, optionally replaced by Cl, P- or P-Sp-), and

R ⁰ , R ⁰⁰ H or alkyl with 1 to 20 C atoms,

Y ¹ halogen,

r 0, 1, 2, 3 or 4;

R ^Q Alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms, or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated,

X ^Q

L ^Q1 to L ^Q6 H or F (wherein at least one of L ^Q1 to L ^Q6 is F),

If R ^A1 represents alkenyl with 2 to 9 C atoms, or at least one of rings X, Y and Z represents cyclohexenyl, it is also one of the meanings of R ^A2 ,

R ^A2 Alkyl with 1 to 12 C atoms (wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH-, -CO-, -OCO- in such a way that the O atoms are not directly connected to each other or -COO-),

^Z _{_ _ _ _ _ _} C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O-, or a single bond, preferably a single bond,

L ^1-4 H, F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ H, preferably H, F or Cl,

x 1 or 2,

z 0 or 1.

The present invention further

- a polymerisable component A) comprising and preferably consisting of one or more polymerisable compounds, at least one of which is a compound of formula (I), and

- a liquid crystal component B comprising, preferably consisting of, one or more mesogenic or liquid crystal compounds, comprising at least one compound of the formula Q and at least one compound selected from the formulas AN and AY (hereinafter “LC host mixture”) Sam Browne)

It relates to an LC medium containing.

The liquid crystalline component B) of the LC medium according to the invention, hereinafter also referred to as “LC host mixture”, preferably contains only LC compounds selected from non-polymerizable low molecular weight compounds, such as compounds of the formulas Q, AN or AY, and is polymerized Optionally contains additives such as initiators, inhibitors, etc.

The invention further relates to LC media or LC displays as described above and below, in which the compounds of formula I, or the polymerisable compounds of component A) are polymerized.

The invention further relates to at least one compound of formula AN and/or AY and at least one compound of formula Q as described above and below, or LC host mixture or LC component B), at least one compound of formula I, and optionally further It relates to a process for preparing LC media described above and below, comprising mixing with LC compounds and/or additives.

The invention further relates to the use of LC media in LC displays, especially PSA displays.

The invention further relates to the present invention in a PSA display, preferably in a PSA display containing an LC medium, for the generation of a tilt angle in an LC medium by in situ polymerization of the compound(s) of formula (I) in an electric or magnetic field. It relates to the use of the LC medium according to the invention.

The invention further relates to an LC display comprising at least one compound of formula I according to the invention or an LC medium, in particular a PSA display, particularly preferably PS-VA, PS-OCB, PS-IPS, PS-FFS, PS- It concerns UB-FFS, PS-Forge-VA or PS-TN displays.

The invention further provides a PSA display, very preferably a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-Forge-VA or PS-TN display. It relates to an LC display comprising at least one compound of the formula I described or a polymer obtainable by polymerization of the polymerisable component A), or comprising an LC medium according to the invention.

The present invention further provides a method of forming a substrate between the substrates, comprising two substrates, at least one of which is transparent, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and one or more polymerizable compounds and an LC component described above and below. It relates to an LC display of the PSA type, comprising a layer of LC media located at , wherein the polymerisable compound polymerizes between the substrates of the display.

The present invention further comprises the steps of filling or providing an LC medium comprising one or more polymerizable compounds as described above and below between the substrates of the display, and polymerizing the polymerizable compounds. It relates to a manufacturing method of an LC display.

The PSA display according to the invention has two electrodes, preferably in the form of transparent layers, applied to one or both of the substrates. In some displays, such as PS-VA, PS-OCB or PS-TN displays, one electrode is applied to each of two substrates. In other displays, for example PS-Forge-VA, PS-IPS or PS-FFS or PS-UB-FFS displays, both electrodes are applied to only one of the two substrates.

In a preferred embodiment, the polymerizable component polymerizes in the LC display while a voltage is applied to the electrodes of the display.

The polymerizable compound of the polymerizable component is preferably polymerized by photopolymerization, very preferably by UV photopolymerization.

Unless stated otherwise, the compounds of formula I are preferably selected from achiral compounds.

As used herein, the terms “active layer” and “switchable layer” refer to a structural and optical layer whose orientation changes upon external stimulation, such as an electric or magnetic field, resulting in a change in the transmittance of the layer for polarized or unpolarized light. refers to a layer of an electro-optical display, for example an LC display, comprising one or more molecules having anisotropy, for example LC molecules.

As used herein, the terms “tilt” and “tilt angle” will be understood to mean the tilt orientation of the LC molecules of the LC medium relative to the surface of the cell in an LC display (here, preferably a PSA display). Here, the tilt angle represents the average angle (<90°) between the longitudinal molecular axis of the LC molecule (LC director) and the surface of the plane-parallel outer plate forming the LC cell. Small values of the inclination angle (i.e. large deviations from the 90° angle) correspond to large inclinations. A suitable method for measuring the tilt angle is provided in the examples. Unless otherwise indicated, the tilt angle values described above and below are according to this measurement method.

As used herein, the terms "reactive mesogen" and "RM" refer to a compound containing a mesogen or liquid crystalline structure and one or more functional groups attached thereto, which are suitable for polymerization and are also called "polymerizable groups" or "P". It will be understood as meaning.

Unless otherwise stated, the term “polymerizable compound” as used herein will be understood to mean a polymerisable monomeric compound.

As used herein, the term “low molecular weight compound” will be understood to mean a compound that is monomeric and/or has not been prepared by polymerization, as opposed to “polymeric compound” or “polymer”.

As used herein, the term “non-polymerizable compound” will be understood to mean a compound that does not contain functional groups suitable for polymerization under conditions normally applied for the polymerization of RMs.

As used herein, the term "mesogenic group" is known to the person skilled in the art and is disclosed in the literature, and due to the anisotropy of attractive and repulsive interactions, especially in liquid crystal (LC) phases of low molecular weight or polymeric materials. It refers to a group that contributes to the formation. Compounds containing mesogenic groups (mesogenic compounds) themselves do not necessarily have to have an LC phase. It is also possible for mesogenic compounds to exhibit LC phase behavior only after mixing with other compounds and/or after polymerization. Typical mesogenic groups are, for example, rigid rod-shaped or disc-shaped units. For an overview of terms and definitions used in connection with mesogenic or LC compounds, see Pure Appl. Chem. 2001, 73(5), 888] and [C. Tschierske, G. Pelzl, S. Diele, and Angew. Chem. 2004 , 116, 6340-6368].

The term "spacer group" as used herein, also referred to hereinafter as "Sp", is known to the person skilled in the art and has been disclosed in the literature, for example in Pure Appl. Chem. 2001, 73(5), 888] and [C. Tschierske, G. Pelzl, S. Diele, and Angew. Chem. 2004 , 116, 6340-6368]. As used herein, the term “spacer group” or “spacer” refers to a flexible group, such as an alkylene group, connecting the mesogenic group and the polymerizable group(s) in a polymerizable mesogenic compound.

은 트랜스-1,4-시클로헥실렌 고리를 나타내고, Above and below,

represents a trans-1,4-cyclohexylene ring,

은 1,4-페닐렌 고리를 나타낸다.

represents a 1,4-phenylene ring.

Above and below, “organic group” refers to a carbon or hydrocarbon group.

“Carbon group” refers to a monovalent or multivalent organic group containing one or more carbon atoms, wherein such group contains no additional atoms (e.g. -C≡C-) or optionally one or more additional atoms such as N, O, Contains S, B, P, Si, Se, As, Te or Ge (e.g. carbonyl, etc.). The term “hydrocarbon group” refers to a carbon group that further contains one or more H atoms and optionally one or more heteroatoms such as N, O, S, B, P, Si, Se, As, Te or Ge.

“Halogen” refers to F, Cl, Br or I.

을 나타낸다.-CO-, -C(=O)- and -C(O)- are carbonyl groups, i.e.

represents.

The carbon or hydrocarbon group may be saturated or unsaturated. Unsaturated groups are, for example, aryl, alkenyl or alkynyl groups. Carbon or hydrocarbon radicals with more than 3 C atoms may be straight-chain, branched and/or cyclic, and may also contain spiro-linked or condensed rings.

The terms “alkyl,” “aryl,” “heteroaryl,” and the like also include multivalent groups such as alkylene, arylene, heteroarylene, and the like.

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

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

Further preferred carbon and hydrocarbon groups are C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkynyl, C ₃ -C ₂₀ allyl, C ₄ -C ₂₀ alkyldienyl, C ₄ -C ₂₀ polyenyl, C ₆ -C ₂₀ cycloalkyl, C ₄ -C ₁₅ cycloalkenyl, C ₆ -C ₃₀ aryl, C 6 -C ₃₀ alkylaryl, C _{6 -C 30} arylalkyl, C ₆ -C ₃₀ Alkylaryloxy, C ₆ -C ₃₀ arylalkyloxy, C ₂ -C ₃₀ heteroaryl, C ₂ -C ₃₀ heteroaryloxy.

Particular preference is given to C ₁ -C ₁₂ alkyl, C ₂ -C ₁₂ alkenyl, C ₂ -C ₁₂ alkynyl, C ₆ -C ₂₅ aryl and C ₂ -C ₂₅ heteroaryl.

Further preferred carbon and hydrocarbon groups are straight-chain, branched or unsubstituted or mono-substituted by F, Cl, Br, I or CN, having 1 to 20, preferably 1 to 12 C atoms. click alkyl, wherein one or more non-adjacent CH ₂ groups are each independently of one another in such a way that the O and/or S atoms are not directly connected to each other -C(R ^x )=C(R ^x )-, -C≡C-, - It can be replaced by N(R ^x )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-.

^R , -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms may be replaced by F or Cl, or 6 to 30 represents an optionally substituted aryl or aryloxy group having 2 to 30 C atoms, or an optionally substituted heteroaryl or heteroaryloxy group having 2 to 30 C atoms.

Preferred alkyl groups are for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, 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-decyl, n-undecyl, n-dodecyl, dodecanyl, trifluoromethyl. , perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl, etc.

Preferred alkenyl groups are, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, etc.

Preferred alkynyl groups are, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, etc.

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-hexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n-undecoxy, n-dodecoxy, etc.

Preferred amino groups are, for example, dimethylamino, methylamino, methylphenylamino, phenylamino, etc.

Aryl and heteroaryl groups may be monocyclic or polycyclic, that is, they may contain one ring (e.g. phenyl) or fused (e.g. naphthyl) or covalently bonded (e.g. biphenyl), or may contain two or more rings which may contain combinations of fused and connected rings. Heteroaryl groups contain one or more heteroatoms, preferably selected from O, N, S and Se.

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, optionally containing fused rings and optionally substituted, are particularly preferred. desirable. Preference is also given to 5-, 6- or 7-membered aryl and heteroaryl groups, where also one or more CH groups may be replaced by N, S or O in such a way that the O atoms and/or S atoms are not directly connected to each other.

Preferred aryl groups are for example phenyl, biphenyl, terphenyl, [1,1':3',1"]terphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, 9,10 -Dihydro-phenanthrene, pyrene, dihydropyrene, chrysene, perylene, tetracene, pentacene, benzopyrene, fluorene, indene, indenofluorene, spirobifluorene, etc.

Preferred heteroaryl groups are, for example, five-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophen, 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 condensed groups such as indole, isoindole, indolizine, indazole, benzimidazole, benzotriazole, Purine, naphthymidazole, phenanthroimidazole, pyridimidazole, pyrazinimidazole, quinoxaline imidazole, 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, acri Dean, phenothiazine, phenoxazine, benzopyridazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthridine, phenanthroline, thieno[2,3b]thi ophene, thieno[3,2b]thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazothiophene, or a combination of these groups.

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

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

(Non-aromatic) alicyclic and heterocyclic groups may be monocyclic, i.e. containing only one ring (e.g. cyclohexane), or polycyclic, i.e. containing multiple rings (e.g. decahydronaphthalene or bicyclooctane). Saturated groups are particularly preferred. Further preference is given to mono-, bi- or tricyclic groups having 5 to 25 ring atoms, optionally containing fused rings and optionally substituted. Further preference is given to 5-, 6-, 7- or 8-membered carbocyclic groups, where also 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 CH ₂ groups may be replaced by -O- and/or -S-.

Preferred alicyclic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, pyrrolidine, 6-membered groups such as cyclohexane, silinane, cyclohexene, tetrahydro. Pyran, tetrahydrothiopyran, 1,3-dioxane, 1,3-dithiane, piperidine, 7-membered groups such as cycloheptane, and fused groups such as tetrahydronaphthalene, decahydronaphthalene, indane, bi. Cyclo[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-methanoine Dan-2,5-diyl.

Preferred substituents are, for example, dissolution-promoting groups such as alkyl or alkoxy, electron-withdrawing groups such as fluorine, nitro or nitrile, or substituents for increasing the glass transition temperature (Tg) of the polymer, especially bulky groups such as t-butyl or an optionally substituted aryl group.

Preferred substituents, also referred to as “L” below, are for example F, Cl, Br, I, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C(=O)N( ^R _{_} ^{_ _ _} _{_} Bornyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, where one or more H atoms may be optionally replaced by F or Cl, optionally substituted silyl having 1 to 20 Si atoms, or 6 is an optionally substituted aryl having from 25 to 25 C atoms, preferably from 6 to 15 C atoms,

_wherein ^R is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, and one or more H atoms are each optionally replaced by F, Cl, P- or P-Sp-,

Y ¹ represents halogen.

“Substituted silyl or aryl” is preferably halogen, -CN, R ⁰ , -OR ⁰ , -CO-R ⁰ , -CO-OR ⁰ , -O-CO-R ⁰ or -O-CO-OR ⁰ means substituted by , where R ⁰ represents H or alkyl having 1 to 20 C atoms.

Particularly preferred substituents L are for example F, Cl, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , and additionally phenyl.

은 바람직하게는

이고, 여기서 L은 상기 지시된 의미 중 하나를 갖는다.

is preferably

, where L has one of the meanings indicated above.

The polymerisable group P is a group suitable for polymerization reactions, such as free-radical or ionic chain polymerization, polyaddition or polycondensation, or for polymer-like reactions, such as addition or condensation to the main polymer chain. Particular preference is given to groups for chain polymerization, especially those containing C=C double bonds or -C≡C- triple bonds, and groups suitable for polymerization involving ring opening, such as oxetane or epoxide groups.

The preferred group P is

,

, CH₂=CW²-(O)_k3-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-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-CW²W³-, HS-CW²W³-, HW²N-, HO-CW²W³-NH-, CH₂=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH-, HOOC-, OCN- 및 W⁴W⁵W⁶Si-로 이루어진 군으로부터 선택되고, 여기서 W¹은 H, F, Cl, CN, CF₃, 페닐 또는 1 내지 5개의 C 원자를 갖는 알킬, 특히 H, F, Cl 또는 CH₃를 나타내고, W² 및 W³은 각각 서로 독립적으로 H 또는 1 내지 5개의 C 원자를 갖는 알킬, 특히 H, 메틸, 에틸 또는 n-프로필을 나타내고, W⁴, W⁵ 및 W⁶은 각각 서로 독립적으로 Cl, 1 내지 5개의 C 원자를 갖는 옥사알킬 또는 옥사카르보닐알킬을 나타내고, W⁷ 및 W⁸은 각각 서로 독립적으로 H, Cl 또는 1 내지 5개의 C 원자를 갖는 알킬을 나타내고, Phe는 P-Sp- 이외의 상기 정의된 하나 이상의 라디칼 L에 의해 임의로 치환된 1,4-페닐렌을 나타내고, k₁, k₂ 및 k₃은 각각 서로 독립적으로 0 또는 1을 나타내고, k₃은 바람직하게는 1을 나타내고, k₄는 1 내지 10의 정수를 나타낸다.CH ₂ =CW ¹ -CO-O-, CH ₂ =CW ¹ -CO-,

,

, CH ₂ =CW ² -(O) _k3 -, CW ¹ =CH-CO-(O) _k3 -, CW ¹ =CH-CO-NH-, CH ₂ =CW ¹ -CO-NH-, CH ₃ - CH=CH-O-, (CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-, (CH ₂ = CH-CH ₂ ) ₂ N-, (CH ₂ =CH-CH ₂ ) ₂ N-CO-, HO-CW ² W ³ -, HS-CW ² W ³ -, HW ² N-, HO-CW ² W ³ -NH-, CH ₂ =CW ¹ -CO-NH-, CH ₂ =CH-(COO) _k1 -Phe-(O) _k2 -, CH ₂ =CH-(CO) _k1 -Phe-(O) _k2 -, Phe-CH=CH-, HOOC-, OCN- and W ⁴ W ⁵ W ⁶ Si-, where W ¹ is H, F, Cl, CN, CF ₃ , phenyl or 1 to 5 represents alkyl having 1 to 5 C atoms, especially H, F, Cl or CH ₃ , W ² and W ³ are each independently of one another H or alkyl having 1 to 5 C atoms, especially H, methyl, ethyl or n- represents the profile, W ⁴ , W ⁵ and W ⁶ each independently represents Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, and W ⁷ and W ⁸ each independently represent H, Cl or alkyl having 1 to 5 C atoms. , Phe represents 1,4-phenylene optionally substituted by one or more radicals L defined above other than P-Sp-, and k ₁ , k ₂ and k ₃ each independently of each other represent 0 or 1, , k ₃ preferably represents 1, and k ₄ represents an integer from 1 to 10.

A very preferred group P is

,

, CH₂=CW²-O-, CH₂=CW²-, CW¹=CH-CO-(O)_k3-, CW¹=CH-CO-NH-, CH₂=CW¹-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=CW¹-CO-NH-, CH₂=CH-(COO)_k1-Phe-(O)_k2-, CH₂=CH-(CO)_k1-Phe-(O)_k2-, Phe-CH=CH- 및 W⁴W⁵W⁶Si-로 이루어진 군으로부터 선택되고, 여기서 W¹은 H, F, Cl, CN, CF₃, 페닐 또는 1 내지 5개의 C 원자를 갖는 알킬, 특히 H, F, Cl 또는 CH₃를 나타내고, W² 및 W³은 각각 서로 독립적으로 H 또는 1 내지 5개의 C 원자를 갖는 알킬, 특히 H, 메틸, 에틸 또는 n-프로필을 나타내고, W⁴, W⁵ 및 W⁶은 각각 서로 독립적으로 Cl, 1 내지 5개의 C 원자를 갖는 옥사알킬 또는 옥사카르보닐알킬을 나타내고, W⁷ 및 W⁸은 각각 서로 독립적으로 H, Cl 또는 1 내지 5개의 C 원자를 갖는 알킬을 나타내고, Phe는 1,4-페닐렌을 나타내고, k₁, k₂ 및 k₃은 각각 서로 독립적으로 0 또는 1을 나타내고, k₃은 바람직하게는 1을 나타내고, k₄는 1 내지 10의 정수를 나타낸다.CH ₂ =CW ¹ -CO-O-, CH ₂ =CW ¹ -CO-,

,

, CH ₂ =CW ² -O-, CH ₂ =CW ² -, CW ¹ =CH-CO-(O) _k3 -, CW ¹ =CH-CO-NH-, CH ₂ =CW ¹ -CO-NH- , (CH ₂ =CH) ₂ CH-OCO-, (CH ₂ =CH-CH ₂ ) ₂ CH-OCO-, (CH ₂ =CH) ₂ CH-O-, (CH ₂ =CH-CH ₂ ) ₂ N-, (CH ₂ =CH-CH ₂ ) ₂ N-CO-, CH ₂ =CW ¹ -CO-NH-, CH ₂ =CH-(COO) _k1 -Phe-(O) _k2 -, CH ₂ = CH-(CO) _k1 -Phe-(O) _k2 -, Phe-CH=CH- and W ⁴ W ⁵ W ⁶ Si-, where W ¹ is H, F, Cl, CN, CF ₃ , represents phenyl or alkyl having 1 to 5 C atoms, especially H, F, Cl or CH ₃ , W ² and W ³ are each independently of one another H or alkyl having 1 to 5 C atoms, especially H , methyl, ethyl or n-propyl, W ⁴ , W ⁵ and W ⁶ each independently represent Cl, oxaalkyl or oxacarbonylalkyl having 1 to 5 C atoms, and W ⁷ and W ⁸ are Each independently of one another represents H, Cl or an alkyl having 1 to 5 C atoms, Phe represents 1,4-phenylene, k ₁ , k ₂ and k ₃ each independently represent 0 or 1, k ₃ preferably represents 1, and k ₄ represents an integer from 1 to 10.

으로 이루어진 군으로부터 선택된다.Very particularly preferred groups P are CH ₂ =CW ¹ -CO-O-, especially CH ₂ =CH-CO-O-, CH ₂ =C(CH ₃ )-CO-O- and CH ₂ =CF-CO-O. -, further CH ₂ =CH-O-, (CH ₂ =CH) ₂ CH-O-CO-, (CH ₂ =CH) ₂ CH-O-,

is selected from the group consisting of

Further preferred polymerisable groups P are selected from the group consisting of vinyloxy, acrylates, methacrylates, fluoroacrylates, chloroacrylates, oxetanes and epoxides, most preferably from acrylates and methacrylates.

If Sp differs from a single bond, the formula Sp"-X" is preferred, so that each radical P-Sp- conforms to the formula P-Sp"-X"-, where

Sp" represents an alkylene having 1 to 20, preferably 1 to 12 C atoms, optionally mono- or polysubstituted by F, Cl, Br, I or CN, wherein also one or more non-adjacent CH _{The two} groups are each independently of one another -O-, -S-, -NH-, -N(R ⁰ )-, -Si(R ⁰ R ⁰⁰ )-, - in such a way that the O and/or S atoms are not directly connected to each other. 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 ^{0 0} )-, -CH=CH- or -C≡C-,

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

R ⁰ and R ⁰⁰ each independently represent H or alkyl having 1 to 20 C atoms,

Y ² and Y ³ each independently represent H, F, Cl or CN.

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

Typical spacer groups Sp and -Sp"-X"- are, for example, -(CH ₂ ) _p1 -, -(CH ₂ CH ₂ O) _q1 -CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ -NH-CH ₂ CH ₂ - or -(SiR ⁰ R ⁰⁰ -O) _p1 -, where p1 is an integer from 1 to 12, and q1 is an integer from 1 to 3. , R ⁰ and R ⁰⁰ have the meanings indicated above.

Particularly preferred groups Sp and -Sp"-X"- are -(CH ₂ ) _p1 -, -(CH ₂ ) _p1 -O-, -(CH ₂ ) _p1 -O-CO-, -(CH ₂ ) _p1 - CO-O-, -(CH ₂ ) _p1 -O-CO-O-, where p1 and q1 have the meanings indicated above.

Particularly preferred groups Sp" are in each case straight-chain ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, octadecylene, ethyleneoxyethylene, They are methyleneoxybutylene, ethylenethioethylene, ethylene-N-methylimino-ethylene, 1-methylalkylene, ethenylene, propenylene and butenylene.

It has been observed that when using the polymerisable compounds of formula I in the LC medium according to the invention, rapid and complete polymerization can be achieved. In particular, the combination of polymerisable compounds of formula I with alkenyl compounds of formula AN and/or AY and quaterphenyl compounds of formula Q led to advantageous behavior of the LC medium, including rapid and complete polymerization, and a small pretilt angle that was stable even after UV exposure. Fast generation, at the same time high reliability and high VHR values after UV exposure can be achieved with high birefringence. In addition, since the LC medium exhibits a high absorption rate in long-wavelength UV, such long-wavelength UV can be used for polymerization, which is advantageous in the display manufacturing process.

Preferred compounds of formula I are those wherein one of Sp ¹ and Sp ² is a single bond and the other is different from the single bond.

Further preferred compounds of formula I are those wherein one of Sp ¹ and Sp ² is a single bond and the other is -(CH ₂ ) _s1 -X"-, where s1 is an integer from 1 to 6, preferably 2, 3 , 4 or 5, and X" is a linking group with the benzene ring and is -O-, -O-CO-, -CO-O, -O-CO-O- or a single bond.

Further preferred compounds of formula I are selected from the following sub-formulas:

wherein P ¹ , P ² , L, and r have the meaning of Formula I or one of the preferred meanings described above and below, and s1 is an integer from 1 to 6, preferably 2, 3, 4 or 5. .

Very preferred compounds are those of formula (I1) and (I2).

Very preferred compounds of formula I are selected from the following sub-formulas:

where P ¹ , P ² and s1 are as defined in Formula I1, s2 is 0 or 1, and L' has one of the meanings given for L above and below. Preferably in these compounds P ¹ and P ² represent acrylate or methacrylate, s1 is 2, 3 or 4 and L' is F.

Further preferred compounds of formula I and its sub-formulas I1-I4 and Ia-If are selected from the following preferred embodiments comprising any combinations thereof:

- P ¹ and P ² are selected from the group consisting of acrylates, methacrylates and oxetane,

- the compound contains exactly two polymerisable groups (denoted as P ¹ and P ³ groups),

- L does not represent or contain a polymerisable group,

- L does not represent or contain a P-Sp- group,

- in at least one of the benzene rings in formula (I) and its sub-formulas, r is not 0 and L is P-Sp-,

- in at least one of the benzene rings in formula (I) and its sub-formulas r is not 0 and L is different from P-Sp- and is not polymerizable, preferably F, Cl, -CN and 1 to 25, especially preferred preferably selected from straight-chain or branched alkyls having 1 to 10 C atoms, wherein one or more non-adjacent CH ₂ groups are each, independently of one another, -C(R ⁰⁰ )=C(R ⁰⁰⁰ )-, -C≡C-, -N(R ⁰⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O- may be replaced by CO-O-, and one or more H atoms may also be replaced by F, Cl, Br, I or CN,

- in at least one of the benzene rings in formula I and its sub-formulas r is 1 or 2 and L is F, CN, and alkyl or alkoxy with 1 to 6 C atoms, optionally fluorinated, preferably F, Cl , CN, CH ₃ , OCH ₃ , OCF ₃ , OCF ₂ H or OCFH ₂ , very preferably F.

Very preferred compounds of formula (I) are those of the formula:

The polymerisable compounds of formula (I) are particularly suitable for use in LC host mixtures comprising one or more mesogens or LC compounds containing alkenyl groups (hereinafter also referred to as “alkenyl compounds”), such as compounds of formulas (AN) and (AY). Suitable wherein the alkenyl group is stable to polymerization under the conditions used for the polymerization of the compounds of formula I and other polymerisable compounds contained in the LC medium. Compared to the RMs known from the prior art, the compounds of formula I exhibit improved properties in these LC host mixtures, such as solubility, reactivity or tilt angle generating ability.

Therefore, in addition to the polymerisable compounds of formula (I), the LC media according to the invention comprise at least one mesogenic or liquid crystalline compound selected from formulas AN and AY comprising alkenyl groups (“alkenyl compounds”), wherein these alkenyl groups The groups are preferably stable to polymerization reactions under the conditions used for the polymerization of the polymerisable compounds of formula (I) or other polymerisable compounds contained in the LC medium.

The LC medium is preferably a compound containing a terminal vinyloxy group (-O-CH=CH ₂ ), especially a compound of the formula where R ^A1 or R ^A2 represents or contains a terminal vinyloxy group (-O-CH=CH ₂ ). It does not include compounds of AN or AY.

Preferred compounds of formula AN and AY are those where R ^A2 is selected from ethenyl, propenyl, butenyl, pentenyl, hexenyl and heptenyl.

In a preferred embodiment, the LC medium comprises at least one compound of formula AN selected from the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl ^* each independently represent a straight-chain alkenyl radical having 2-7 C atoms. indicates. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Preferably, the LC medium comprises at least one compound of the formula AN1 or AN2, very preferably at least one compound of the formula AN1.

In another embodiment, the LC medium comprises one or more compounds of formula AN selected from the following sub-formulas:

In the formula, m represents 1, 2, 3, 4, 5 or 6, i represents 0, 1, 2 or 3, and R ^b1 represents H, CH ₃ or C ₂ H ₅ .

In another embodiment, the LC medium comprises one or more compounds selected from the following subformulas:

Compounds of formula AN1a2 and AN1a5 are most preferred.

In a preferred embodiment, the LC medium comprises one or more compounds of formula AY selected from the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl ^* each independently represent a straight-chain alkenyl radical having 2-7 C atoms. indicates. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

In another preferred embodiment, the LC medium comprises one or more compounds of formula AY selected from the following sub-formulas:

In the formula, m and n each independently represent 1, 2, 3, 4, 5 or 6, and alkenyl is CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH- , CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ - represents.

Preferably, the proportion of compounds of formula AN and AY in the LC medium is 2 to 60%, very preferably 5 to 45% and most preferably 10 to 40%.

Preferably, the LC medium contains 1 to 5, preferably 1, 2 or 3 compounds of the formulas AN and AY.

To achieve rapid response times, low rotational viscosity γ ₁ and narrow cell spacing of the LC medium are required. Prior art LC media often use alkenyl and terphenyl compounds to satisfy these requirements. However, LC media have reduced reliability and control issues due to the drop in VHR after UV stress. Surprisingly, it has been found that this problem can be reduced when using quarterphenyl compounds of formula Q in the LC medium.

Therefore, in addition to the polymerisable compounds of formula I and the compounds of formula AN and AY, the LC medium according to the invention comprises at least one quarterphenyl compound of formula Q.

Preferred compounds of formula Q are those in which R ^Q represents straight-chain alkyl having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

Preferred compounds of formula Q are those where L ^Q3 and L ^Q4 are F. Further preferred compounds of formula Q are L ^Q3 , L ^Q4 , and compounds in which one or two of L ^Q1 and L ^Q2 are F.

Preferred compounds of formula Q are those in which X ^Q represents F or OCF ₃ , very preferably F.

Compounds of formula Q are preferably selected from the following sub-formulas:

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

Particular preference is given to compounds of formula Q1, especially those in which R ^Q is n-propyl.

Preferably, the proportion of compounds of formula Q in the LC medium is >0 to ≤5%, very preferably 0.1 to 2%, most preferably 0.2 to 1.5%.

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

By using quarterphenyl compounds of formula Q and its subformulas, it is possible to replace terphenyl compounds in the LC host mixture. This can reduce ODF mura while maintaining high UV absorption and enabling rapid and complete polymerization and strong tilt angle generation.

Therefore, in a preferred embodiment of the invention, the LC component B) of the LC medium contains no more than 15% terphenyl compounds, and very preferably no terphenyl compounds.

The addition of quarterphenyl compounds of formula Q can enhance and accelerate tilt angle generation and increase the UV stability of the LC medium. However, it has been observed that the addition of quarterphenyl compounds, such as compounds of formula Q, can sometimes result in an increase in viscosity of the LC host mixture. It has been found that by adding small amounts of compounds of formula C, as defined below, it is possible to maintain low viscosity while retaining the advantages achieved by adding quarterphenyl compounds of formula Q.

Therefore, in another preferred embodiment of the invention, the LC component B) of the LC medium contains at least one selected compound of formula C:

In the formula, the individual radicals have, identically or differently, in each occurrence, each independently of the other, the following meanings:

R ^C alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms, or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated,

X ^C

L ^C1 , L ^C2 H or F, where at least one of L ^C1 and L ^C2 is F.

Preferred compounds of formula C are those in which R ^C represents straight-chain alkyl having 2 to 6 C atoms, very preferably ethyl, n-propyl or n-butyl.

Preferred compounds of formula C are those where L ^C1 and L ^C2 are F.

Preferred compounds of formula C are those in which X ^C represents F or OCF ₃ , very preferably F.

Preferred compounds of formula C are selected from the formula:

where R ^C has one of the meanings of formula C or one of its preferred meanings given above and below, and is preferably ethyl, n-propyl or n-butyl, very preferably n-propyl.

Preferably, the proportion of compounds of formula C in the LC medium is >0 to ≤10%, very preferably 0.1 to 8% and most preferably 0.2 to 5%.

Preferably, the LC medium contains 1 to 5, preferably 1, 2 or 3 compounds of formula C.

Additionally, by adding small amounts of compounds of formula Q and optionally formula C, with positive dielectric anisotropy, to the LC medium or LC host mixture with negative dielectric anisotropy, the dielectric constant ε _|| and ε _⊥ values become possible, especially for high dielectric constants ε _|| It was observed that the kickback voltage can be reduced and the afterimage can be reduced by maintaining the dielectric anisotropy Δε constant while achieving this value.

In the production of PSA displays, the polymerizable compounds contained in the LC medium are polymerized or crosslinked by in situ polymerization in the LC medium between the substrates of the LC display, optionally while a voltage is applied to the electrodes (one compound (if it contains more than one polymerizable group).

The structure of the PSA display according to the invention corresponds to the conventional geometry of the PSA display, disclosed in the prior art cited at the beginning. A geometry without protrusions is preferred, especially a geometry where the electrodes on the color filter side are unstructured and only the electrodes on the TFT side have slots. Particularly suitable and preferred electrode structures for PS-VA displays are disclosed, for example, in US 2006/0066793 A1.

A preferred PSA type LC display of the present invention is

- a first substrate defining a pixel area, connected to a switching element disposed in each pixel area, and comprising a pixel electrode, optionally comprising a micro-slit pattern, and optionally a first orientation layer disposed on the pixel electrode,

- a second substrate comprising a common electrode layer that can be disposed on the entire part of the second substrate opposite the first substrate, and optionally a second orientation layer,

- an LC layer disposed between a first substrate and a second substrate, comprising an LC medium comprising a polymerisable component A and a liquid crystalline component B described above and below, wherein the polymerisable component A is also polymerizable.

Includes.

The first and/or second alignment layer controls the orientation direction of the LC molecules in the LC layer. For example, in PS-VA displays, the orientation layer is selected to provide the LC molecules with a homeotropic (or perpendicular) orientation (i.e., perpendicular to the surface) or an inclined orientation. This orientation layer may comprise, for example, polyimide, which may also be rubbed or produced by photo-alignment methods.

The LC layer with LC medium can be disposed between the substrates of the display by methods commonly used by display manufacturers, for example the so-called liquid crystal drop injection (ODF) method. Afterwards, the polymerisable component of the LC medium is polymerized, for example by UV photopolymerization. Polymerization may be carried out in one step or in two or more steps.

PSA displays may include additional elements such as color filters, black matrices, passivation layers, optical phase retardation layers, transistor elements for addressing individual pixels, etc., all of which will be well known to those skilled in the art. It is known and can be used without the technology of the present invention.

The electrode structure can be designed by a person skilled in the art, depending on the individual display type. For example, in the case of PS-VA displays, multidomain orientation of LC molecules can be induced by providing electrodes with slits and/or convexities or protrusions to result in two, four or more different tilt orientation directions. .

Upon polymerization, the polymerizable compounds form cross-linked polymers, which result in a specific pretilt of the LC molecules in the LC medium. Without wishing to be bound by a particular theory, it is believed that at least a portion of the cross-linked polymer formed by the polymerizable compound will phase-separate or precipitate from the LC medium, forming a polymer layer on the substrate or electrode, or orientation layer provided thereon. Microscopic measurement data (e.g., SEM and AFM) confirmed that at least a portion of the formed polymer accumulated at the LC/substrate interface.

Polymerization can be carried out in one step. In order to create a pretilt angle in the first step, polymerization is first performed while optionally applying a voltage, and then polymerized or crosslinked in the second polymerization step without applying voltage (“final Hardening") is also possible.

Suitable and preferred polymerization methods are, for example, thermal or photopolymerization, preferably photopolymerization, especially UV-induced photopolymerization, which can be achieved by exposing the polymerisable compound to UV radiation.

Optionally one or more polymerization initiators are added to the LC medium. Suitable polymerization conditions and suitable types and amounts of initiators are known to those skilled in the art and are disclosed in the literature. For example, the commercially available photoinitiators Irgacure651®, Irgacure184®, Irgacure907®, Irgacure369® or Darocure1173® (Ciba AG). Suitable for free radical polymerization. If a polymerization initiator is used, its proportion is preferably 0.001 to 5% by weight, particularly preferably 0.001 to 1% by weight.

The polymerisable compounds according to the invention are also suitable for polymerizations in which no initiator is used, which is accompanied by significant advantages, such as reduced material costs and, in particular, reduced contamination of the LC medium with possible residual amounts of the initiator or its decomposition products. Accordingly, polymerization can also be carried out without the addition of an initiator. Accordingly, in a preferred embodiment, the LC medium contains no polymerization initiator.

The LC medium may also contain one or more stabilizers to prevent undesirable spontaneous polymerization of RM, for example during storage or transport. Suitable types and amounts of stabilizers are known to those skilled in the art and are disclosed in the literature. For example, commercially available stabilizers from the Irganox® series (Ciba AG), such as Irganox® 1076, are particularly suitable. If a stabilizer is used, its proportion based on the total amount of RM or polymerisable component (component A) is preferably 10-500,000 ppm, particularly preferably 50-50,000 ppm.

The polymerisable compounds of formula (I) exhibit particularly good UV absorption and are therefore particularly suitable for the production of PSA displays comprising one or more of the following features:

- the polymerizable medium is displayed in a two-step method comprising a first UV exposure step to create a tilt angle ("UV-1 step"), and a second UV exposure step to finish polymerization ("UV-2 step") exposed to UV light.

- The polymerizable medium is exposed to UV light generated by energy-saving UV lamps (also called “green UV lamps”) in the display. These lamps are characterized by a relatively low intensity (1/100-1/10 of a conventional UV1 lamp) in the absorption spectrum at 300-380 nm and are preferably used in the UV2 phase, although, depending on the purpose, high intensities can be avoided. When necessary, it may be used arbitrarily in the UV1 stage.

- The polymerizable medium is exposed to UV light generated by a UV lamp with a radiation spectrum shifted to longer wavelengths, preferably above 340 nm, to avoid short UV light exposure in the PS-VA process in the display.

By using both low intensity and UV shifts to longer wavelengths, the organic layer is protected against damage that can be caused by UV light.

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

- a two-step process, wherein the polymerizable LC medium comprises a first UV exposure step to create a tilt angle ("UV-1 step"), and a second UV exposure step to finish polymerization ("UV-2 step") exposed to UV light.

- the polymerizable LC medium is generated by a UV lamp with an intensity of 0.5 mW/cm ² to 10 mW/cm ² in the wavelength range of 300-380 nm, preferably used in the UV2 stage and optionally also used in the UV1 stage. exposed to UV light.

- The polymerizable LC medium is exposed to UV light with a wavelength of at least 340 nm, and preferably at most 400 nm.

This preferred method can be achieved, for example, by using a preferred UV lamp or a bandpass filter that is substantially transmissive to UV light of each desired wavelength(s) and also substantially blocks light of each undesirable wavelength(s); /Or this can be done by using a blocking filter. For example, when irradiation of UV light with a wavelength λ of 300-400 nm is desired, the UV exposure can be performed using a broadband pass filter that is substantially transparent for wavelengths 300 nm < λ < 400 nm. When irradiation with UV light with a wavelength λ greater than 340 nm is desired, the UV exposure can be carried out using a cut-off filter that is substantially transparent for wavelengths λ > 340 nm.

“Substantially transparent” means that the filter transmits a significant portion of the incident light of the desired wavelength(s), preferably at least 50% of the intensity. “Substantially blocking” means that the filter does not transmit a significant portion of incident light of undesirable wavelengths, preferably more than 50% of the intensity. “Desirable (undesirable) wavelength” means, for example, a wavelength within (outside) a given range of λ in the case of a bandpass filter, or a wavelength above (below) a given range of λ in the case of a cutoff filter. do.

This preferred method uses long wavelength UV, thereby allowing the manufacture of displays while reducing or even avoiding the detrimental damaging effects of short UV light components.

The UV radiation energy is generally between 6 and 100 J, depending on the manufacturing process conditions.

Preferably, the LC medium according to the invention consists essentially of polymerisable component A) and LC component B) (or LC host mixture) described above and below. However, the LC medium may contain one or more additional components or additives, preferably comonomers, chiral dopants, polymerization initiators, inhibitors, stabilizers, surfactants, wetting agents, lubricants, dispersants, hydrophobizing agents, adhesives, flow improvers, anti-foaming agents. , air separation agents, diluents, reactive diluents, auxiliaries, colorants, dyes, pigments and nanoparticles, but may further include those selected from the list.

Preference is given to LC media in which the polymerisable component A) consists solely of the polymerisable compounds of formula (I).

In another preferred embodiment, the polymerisable component A), in addition to the compounds of formula (I), contains at least one further polymerisable compound (“comonomer”), preferably selected from RM.

Suitable and preferred mesogenic comonomers are selected from the formula:

In the formula, individual radicals have the following meanings:

P ¹ , P ² and P ³ each independently represent an acrylate or methacrylate group,

Sp ¹ , Sp ² and Sp ³ each, independently of one another, represent a single bond or a spacer group having one of the meanings indicated above and below for Sp ¹ , particularly preferably -(CH ₂ ) _p1 -, -(CH ₂ ) _p1 -O-, -(CH ₂ ) _p1 -CO-O-, -(CH ₂ ) _p1 -O-CO- or -(CH ₂ ) _p1 -O-CO-O-, where p1 is is an integer from 1 to 12, and also one or more of the P ¹ -Sp ¹ -, P ¹ -Sp ² - and P ³ -Sp ³ - radicals may represent R ^aa , provided that the P ¹ -Sp ¹ - present, P ² -Sp ² and P ³ -Sp ³ - at least one of the radicals is different from R ^aa ,

R ^aa represents H, F, Cl, CN or a straight-chain or branched alkyl having 1 to 25 C atoms, wherein also one or more non-adjacent CH ₂ groups are each independently of one another and the O and/or S atoms are not directly connected to each other. C(R ⁰ )=C(R ⁰⁰ )-, -C≡C-, -N(R ⁰ )-, -O-, -S-, -CO-, -CO-O-, -O can be replaced by -CO-, -O-CO-O-, and also at least one H atom can be replaced by F, Cl, CN or P ¹ -Sp ¹ -, especially preferably in a straight chain having 1 to 12 C atoms. or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy (wherein Kenyl and alkynyl radicals have 2 or more C atoms and branched radicals have 3 or more C atoms),

R ⁰ , R ⁰⁰ each independently of one another, identically or differently in each case, represents H or an alkyl having 1 to 12 C atoms,

R ^y and R ^z each independently represent H, F, CH ₃ or CF ₃ ,

X ¹ , X ² and X ³ each independently represent -CO-O-, -O-CO- or a single bond,

Z ¹ represents -O-, -CO-, -C(R ^y R ^z )- or -CF ₂ CF ₂ -,

Z ² and Z ³ are each independently -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -CF ₂ O-, -OCF ₂ - or -(CH ₂ ) _n -, where n is 2, 3 or 4,

L, identically or differently at each occurrence, is F, Cl, CN or a straight or branched alkyl having 1 to 12 C atoms, optionally mono- or polyfluorinated, alkoxy, alkenyl, alkynyl, alkyl represents carbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy, preferably F,

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

r represents 0, 1, 2, 3 or 4,

s represents 0, 1, 2 or 3,

t represents 0, 1 or 2,

x represents 0 or 1.

Particular preference is given to compounds of formula M2, M13, M17, M22, M23 and M29.

Further preference is given to the trireactive compounds M15 to M30, especially M17, M18, M19, M22, M23, M24, M25, M29 and M30.

은 바람직하게는In compounds of formula M1 to M30, the groups

is preferably

이고, 식 중 L은 각각의 경우에 동일하게 또는 상이하게 상기 또는 하기에 제공된 의미 중 하나를 갖고, 바람직하게는 F, Cl, CN, NO₂, CH₃, C₂H₅, C(CH₃)₃, CH(CH₃)₂, CH₂CH(CH₃)C₂H₅, OCH₃, OC₂H₅, COCH₃, COC₂H₅, COOCH₃, COOC₂H₅, CF₃, OCF₃, OCHF₂, OC₂F₅ 또는 P-Sp-, 매우 바람직하게는 F, Cl, CN, CH₃, C₂H₅, OCH₃, COCH₃, OCF₃ 또는 P-Sp-, 보다 바람직하게는 F, Cl, CH₃, OCH₃, COCH₃ 또는 OCF₃, 특히 F 또는 CH₃이다.

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

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

Particular preference is given to LC media comprising 1, 2 or 3 polymerisable compounds of formula (I).

Preferably, the proportion of compounds of formula I in the LC medium is 0.01 to 5%, very preferably 0.05 to 1% and most preferably 0.1 to 0.5%.

Preferably, the proportion of LC component B) in the LC medium is 95 to <100%, very preferably 99 to <100%.

In addition to the polymerisable component A) described above, the LC medium according to the invention comprises an LC component B) comprising at least one, preferably at least two LC compounds selected from non-polymerizable low molecular weight compounds, or an LC host mixture. These LC compounds are selected to be stable and/or unreactive toward polymerization under the conditions applicable to the polymerization of the polymerizable compound.

Examples of such compounds are the above-mentioned compounds of formulas Q, AN and AY.

It is preferred that the LC component B), or the LC host mixture, has a nematic LC phase, preferably an LC medium without a chiral liquid crystalline phase. The LC component B), or LC host mixture, is preferably a nematic LC mixture. Further preferably, the LC component B) or the LC host mixture and the LC medium have a negative dielectric anisotropy Δε.

Additional preference is given to LC media in which the achiral compounds of formula I and the compounds of components A and/or B are selected only from the group consisting of achiral compounds.

In a first preferred embodiment, the LC medium contains an LC component B), or an LC host mixture, based on compounds with negative dielectric anisotropy. These LC media are particularly suitable for use in PS-VA and PS-UB-FFS displays. Particularly preferred embodiments of these LC media are those in sections a)-z) below:

a) LC medium comprising at least one compound of formula CY and/or PY:

During the ceremony,

a represents 1 or 2,

b represents 0 or 1,

은

을 나타내고,

silver

represents,

R ¹ and R ² each independently represent an alkyl having 1 to 12 C atoms, wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH in such a way that the O atoms are not directly connected to each other. -, -CO-, -OCO- or -COO-, preferably by alkyl or alkoxy having 1 to 6 C atoms,

Z ^x and Z ^y are each independently -CH ₂ CH ₂ -, -CH=CH-, -CF ₂ O-, -OCF ₂ -, -CH ₂ O-, -OCH ₂ -, -CO-O- , -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O- or a single bond, preferably a single bond,

L ^1-4 each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, L ¹ and L ² both represent F, or one of L ¹ and L ² represents F and the other represents Cl, or L ³ and L ⁴ both represent F, or L One of ³ and L ⁴ represents F and the other represents Cl.

Compounds of formula CY are preferably selected from the group consisting of the following sub-formulas:

In the formula, a represents 1 or 2, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2-6 C atoms. and (O) represents an oxygen atom or a single bond. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Compounds of formula PY are preferably selected from the group consisting of the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, alkenyl represents a straight-chain alkenyl radical having 2-6 C atoms, and (O) is an oxygen atom. Or it represents a single bond. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

b) LC medium further comprising at least one compound of the formula:

In the formula, individual radicals have the following meanings:

은

을 나타내고,

silver

represents,

은

을 나타내고,

silver

represents,

R ³ and R ⁴ each, independently of one another, represent an alkyl having 1 to 12 C atoms, wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH in such a way that the O atoms are not directly connected to each other. may be replaced by -, -CO-, -O-CO- or -CO-O-,

Z ^y is -CH ₂ CH ₂ -, -CH=CH-, -CF ₂ O-, -OCF ₂ -, -CH ₂ O-, -OCH ₂ -, -CO-O-, -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O- or a single bond, preferably a single bond.

Compounds of formula ZK are preferably selected from the group consisting of the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Compounds of formula ZK1 are particularly preferred.

Particularly preferred compounds of formula ZK are selected from the following sub-formulas:

wherein the propyl, butyl and pentyl groups are straight chain groups.

Compounds of formula ZK1a are most preferred.

c) LC medium further comprising at least one compound of the formula:

In the formulas, the individual radicals have the following meanings, either identically or differently, at each occurrence:

R ⁵ and R ⁶ each independently represent an alkyl having 1 to 12 C atoms, wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH in such a way that the O atoms are not directly connected to each other. -, -CO-, -OCO- or -COO-, preferably by alkyl or alkoxy having 1 to 6 C atoms,

은

을 나타내고,

silver

represents,

은

을 나타내고,

silver

represents,

e represents 1 or 2.

Compounds of formula DK are preferably selected from the group consisting of the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl represents a straight-chain alkenyl radical having 2-6 C atoms. Alkenyl is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

d) LC medium further comprising at least one compound of the formula:

In the formula, individual radicals have the following meanings:

은

을 나타내고, 여기서 하나 이상의 고리 F는 시클로헥실렌과 상이하고,

silver

represents, where at least one ring F is different from cyclohexylene,

f represents 1 or 2,

R ¹ and R ² each, independently of one another, represent an alkyl having 1 to 12 C atoms, where also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH= in such a way that the O atoms are not directly connected to each other. may be replaced by CH-, -CO-, -OCO- or -COO-,

Z ^x is -CH ₂ CH ₂ -, -CH=CH-, -CF ₂ O-, -OCF ₂ -, -CH ₂ O-, -OCH ₂ -, -CO-O-, -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O- or a single bond, preferably a single bond,

L ¹ and L ² each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, the L ¹ and L ² radicals both represent F, or one of the L ¹ and L ² radicals represents F and the other represents Cl.

Compounds of formula LY are preferably selected from the group consisting of the following sub-formulas:

wherein R ¹ has the meaning indicated above, alkyl represents a straight-chain alkyl radical having 1-6 C atoms, (O) represents an oxygen atom or a single bond, and v represents an integer from 1 to 6. . R ¹ is preferably straight-chain alkyl with 1 to 6 C atoms or straight-chain alkenyl with 2 to 6 C atoms, especially CH ₃ , C ₂ H ₅ , nC ₃ H ₇ , nC ₄ H ₉ , nC ₅ H ₁₁ , CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH- , CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

e) LC medium further comprising at least one compound selected from the group consisting of:

wherein alkyl represents C _1-6 -alkyl, L ^x represents H or F, and X represents F, Cl, OCF ₃ , OCHF ₂ or OCH=CF ₂ . Particular preference is given to compounds of formula G1 where X represents F.

f) LC medium further comprising at least one compound selected from the group consisting of:

wherein R ⁵ has one of the meanings indicated above for R ¹ , alkyl represents C _1-6 -alkyl, d represents 0 or 1, and z and m each independently represent 1 to 6 Represents an integer. In these compounds R ⁵ is particularly preferably C _1-6 -alkyl or -alkoxy or C _2-6 -alkenyl, and d is preferably 1. The LC medium according to the invention preferably comprises at least one compound of the above-mentioned formula in an amount of ≧5% by weight.

g) LC medium further comprising at least one biphenyl compound selected from the group consisting of:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, and alkenyl and alkenyl ^* each independently represent a straight-chain alkenyl radical having 2-6 C atoms. indicates. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

The proportion of biphenyls of formulas B1 to B3 in the LC mixture is preferably at least 3% by weight, especially ≧5% by weight.

Compounds of formula B2 are particularly preferred.

Compounds of formulas B1 to B3 are preferably selected from the group consisting of the following sub-formulas:

In the formula, alkyl ^* represents an alkyl radical having 1-6 C atoms. The medium according to the invention particularly preferably comprises one or more compounds of formula B1a and/or B2c.

h) LC medium further comprising at least one terphenyl compound of the formula:

In the formula, R ⁵ and R ⁶ each independently have one of the meanings indicated above,

은 각각 서로 독립적으로

are each independently

을 나타내고, 여기서 L⁵는 F 또는 Cl, 바람직하게는 F를 나타내고, L⁶은 F, Cl, OCF₃, CF₃, CH₃, CH₂F 또는 CHF₂, 바람직하게는 F를 나타낸다.

where L ⁵ represents F or Cl, preferably F, and L ⁶ represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ , preferably F.

Compounds of formula T are preferably selected from the group consisting of the following sub-formulas:

wherein R represents a straight-chain alkyl or alkoxy radical having 1-7 C atoms, R ^* represents a straight-chain alkenyl radical having 2-7 C atoms, (O) represents an oxygen atom or a single bond, , m represents an integer from 1 to 6. R ^* is preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH =CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

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

Particular preference is given to compounds of formula T1, T2, T3 and T21. In these compounds, R preferably represents alkyl, each having 1-5 C atoms, and further alkoxy.

Preferably, the LC component B) of the LC medium contains up to 15% of a compound of formula T or any other compound having a terphenyl group. Very preferably, the LC component B) of the LC medium does not contain terphenyl compounds of formula T or any other compounds having terphenyl groups.

i) LC medium further comprising at least one compound selected from the group consisting of the formula:

In the formula, R ¹ and R ² have the meanings indicated above, and preferably each independently of one another represents straight-chain alkyl having 1 to 6 C atoms or straight-chain alkenyl having 2 to 6 C atoms.

Preferred media comprise one or more compounds selected from the formulas O1, O3 and O4.

k) LC medium further comprising at least one compound of the formula:

은During the ceremony,

silver

을 나타내고,

represents,

R ⁹ represents H, CH ₃ , C ₂ H ₅ or nC ₃ H ₇ , (F) represents an optional fluorine substituent, q represents 1, 2 or 3 and R ⁷ is indicated relative to R ¹ It has one meaning.

Particularly preferred compounds of formula FI are selected from the group consisting of the following sub-formulas:

In the formula, R ⁷ preferably represents straight-chain alkyl and R ⁹ represents CH ₃ , C ₂ H ₅ or nC ₃ H ₇ . Compounds of formula FI1, FI2 and FI3 are particularly preferred.

l) LC medium further comprising at least one compound selected from the group consisting of the formula:

wherein R ⁸ has the meaning indicated for R ¹ and alkyl represents a straight-chain alkyl radical having 1-6 C atoms.

m) LC medium further comprising at least one compound containing tetrahydronaphthyl or naphthyl units, such as a compound selected from the group consisting of:

In the formula, R ¹⁰ and R ¹¹ each independently represent an alkyl having 1 to 12 C atoms, where also 1 or 2 non-adjacent CH ₂ groups are -O-, - in such a way that the O atoms are not directly connected to each other. CH=CH-, -CO-, -OCO- or -COO-, preferably replaced by alkyl or alkoxy having 1 to 6 C atoms,

R ¹⁰ and R ¹¹ preferably represent straight-chain alkyl or alkoxy with 1 to 6 C atoms, or straight-chain alkenyl with 2 to 6 C atoms,

Z ¹ and Z ² are each independently -C ₂ H ₄ -, -CH=CH-, -(CH ₂ ) ₄ -, -(CH ₂ ) ₃ O-, -O(CH ₂ ) ₃ -, - CH=CH-, -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH=CH-, -CH ₂ O-, -OCH ₂ -, -CO-O-, -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CF=CH-, -CH=CF-, -CH ₂ - or represents a single bond.

n) LC medium further comprising at least one difluorodibenzo-chromane and/or chroman of the formula:

In the formula, R ¹¹ and R ¹² each independently have one of the meanings indicated above for R ¹¹ ,

Ring M is trans-1,4-cyclohexylene or 1,4-phenylene,

Z ^m is -C ₂ H ₄ -, -CH ₂ O-, -OCH ₂ -, -CO-O- or -O-CO-,

c is 0, 1 or 2.

Particularly preferred compounds of the formulas BC, CR and RC are selected from the group consisting of the following sub-formulas:

wherein alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, (O) represents an oxygen atom or a single bond, c is 1 or 2, alkenyl and alkenyl ^* represents a straight-chain alkenyl radical having 2-6 C atoms each independently of one another. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Very particular preference is given to mixtures comprising 1, 2 or 3 compounds of formula BC-2.

o) LC medium further comprising at least one fluorinated phenanthrene and/or dibenzofuran of the formula:

In the formula, R ¹¹ and R ¹² each independently have one of the meanings indicated above for R ¹¹ , b represents 0 or 1, L represents F, and r represents 1, 2 or 3.

Particularly preferred compounds of formula PH and BF are selected from the group consisting of the following sub-formulas:

In the formula, R and R' each independently represent a straight-chain alkyl or alkoxy radical having 1-7 C atoms.

p) LC medium further comprising at least one monocyclic compound of the formula:

In the formula, R ¹ and R ² each independently represent an alkyl having 1 to 12 C atoms, where also 1 or 2 non-adjacent CH ₂ groups are -O-, - in such a way that the O atoms are not directly connected to each other. CH=CH-, -CO-, -OCO- or -COO-, preferably replaced by alkyl or alkoxy having 1 to 6 C atoms,

L ¹ and L ² each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, and CHF ₂ .

Preferably, L ¹ and L ² both represent F, or at least one of L ¹ and L ² represents F and the other represents Cl.

Compounds of formula Y are preferably selected from the group consisting of the following sub-formulas:

In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, alkoxy represents a straight-chain alkoxy radical having 1-6 C atoms, and alkenyl and alkenyl ^* each represent a straight-chain alkyl radical having 1-6 C atoms. Independently of one another, it represents a straight-chain alkenyl radical having 2-6 C atoms, and O represents an oxygen atom or a single bond. Alkenyl and alkenyl ^* are preferably CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -.

Particularly preferred compounds of formula Y are selected from the group consisting of the following sub-formulas:

In the formula, alkoxy preferably represents straight-chain alkoxy having 3, 4, or 5 C atoms.

q) LC medium which, other than the polymerisable compounds and comonomers according to the invention, especially of formula (I) or sub-formulas thereof, does not contain compounds containing terminal vinyloxy groups (-O-CH=CH ₂ ).

r) LC medium comprising 1 to 5, preferably 1, 2 or 3 polymerisable compounds, preferably selected especially from polymerisable compounds according to the invention of formula (I) or sub-formulas thereof.

s) LC medium, wherein the proportion of polymerisable compounds of the general formula (I) or sub-formulas thereof in the mixture is 0.05 to 5% overall, preferably 0.1 to 1%.

t) LC medium comprising 1 to 8, preferably 1 to 5 compounds of the formula CY1, CY2, PY1 and/or PY2. The overall proportion of these compounds in the mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably 2 to 20% in each case.

u) LC medium comprising 1 to 8, preferably 1 to 5 compounds of formula CY9, CY10, PY9 and/or PY10. The overall proportion of these compounds in the mixture is preferably 5 to 60%, particularly preferably 10 to 35%. The content of these individual compounds is preferably 2 to 20% in each case.

v) LC medium comprising 1 to 10, preferably 1 to 8 compounds of formula ZK, especially formulas ZK1, ZK2 and/or ZK6. The overall proportion of these compounds in the mixture is preferably 3 to 25%, particularly preferably 5 to 45%. The content of these individual compounds is preferably 2 to 20% in each case.

w) LC medium in which the proportion of compounds of the formulas CY, PY and ZK in the mixture overall exceeds 70%, preferably exceeds 80%.

x) the LC host mixture preferably has one or both of the formulas CY, PY and LY, R ³ and R ⁴ , wherein either or both of R ¹ and R ² represent a straight chain alkenyl having 2-6 C atoms. , or either or both R ⁵ and R ⁶ represent a straight chain alkenyl having 2-6 C atoms, very preferably selected from the group consisting of formulas ZK and DK, and formulas B2 and B3, very preferably formulas CY15, CY16 LC containing at least one compound containing an alkenyl group selected from , CY24, CY32, PY15, PY16, ZK3, ZK4, DK3, DK6, B2 and B3, most preferably selected from the formulas ZK3, ZK4, B2 and B3 medium. The concentration of these compounds in the LC host mixture is preferably 2 to 70%, very preferably 3 to 55%.

y) LC medium containing at least one selected, preferably 1 to 5 compounds of the formula PY1-PY8, very preferably of the formula PY2. The overall proportion of these compounds in the mixture is preferably 1 to 30%, particularly preferably 2 to 20%. The content of these individual compounds is preferably 1 to 20% in each case.

z) LC medium containing at least one, preferably 1, 2 or 3 compounds of formula T2. The overall content of these compounds in the mixture is preferably 1 to 20%.

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

Contains one or more compounds selected from the group consisting of compounds of formula AA and BB,

In addition to compounds of formula AA and/or BB, optionally containing one or more compounds of formula CC,

Particular preference is given to the LC medium of the second preferred embodiment, wherein the individual radicals have the following meanings:

각각 서로 독립적으로, 각각의 경우에 동일하게 또는 상이하게

each independently of the other, identically or differently in each case

각각 서로 독립적으로, 각각의 경우에 동일하게 또는 상이하게

each independently of the other, identically or differently in each case

R ²¹ , R ³¹ , R ⁴¹ , R ⁴² each independently of one another is alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms, or alkenyl or alkenyloxy having 2 to 9 C atoms (which are all optionally fluorinated),

^X0

Z ³¹ -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH ₂ O- or a single bond, preferably -CH ₂ CH ₂ -, -COO-, trans-CH=CH- or a single bond, especially preferably -COO-, trans-CH=CH- or a single bond,

Z ⁴¹ , Z ⁴² -CH ₂ CH ₂ -, -COO-, trans-CH=CH-, trans-CF=CF-, -CH ₂ O-, -CF ₂ O-, -C≡C- or single bond , preferably a single bond,

L ²¹ , L ²² , L ³¹ , L ³² H or F,

g 0, 1, 2 or 3,

h 0, 1, 2 or 3.

X ⁰ preferably f, cl, CF ₃ , CHF ₂ , OCF ₃ , OCHF ₂ , OCFHCF ₃ , OCFHCHF ₂ , OCFHCHF ₂ , OCF ₂ CH ₃ , _{OCF 2 CHF 2} , OCF _{2 CF 2} CHF ₂ , OCF ₂ CF ₂ CHF ₂ , OCFHCF ₂ CF ₃ , OCFHCF ₂ CHF ₂ , OCF ₂ CF ₂ CF ₃ , OCF ₂ CF ₂ CClF ₂ , OCClFCF ₂ CF ₃ or CH=CF ₂ , very preferably F or It is OCF ₃ .

Compounds of formula AA are preferably selected from the group consisting of:

In ^{the formula , A 21 , R 21} , Compounds of formula AA1 and AA2 are particularly preferred.

Particularly preferred compounds of formula AA1 are selected from the group consisting of the following sub-formulas:

^{wherein R 21 , _ _ _ _ _} It's F.

Very particularly preferred compounds of formula AA1 are selected from the group consisting of the following sub-formulas:

wherein R ²¹ is as defined in formula AA1.

Very preferred compounds of formula AA2 are selected from the group consisting of the following sub-formulas:

^{wherein R 21 , _ _ _ _ _} It's F.

Very particularly preferred compounds of formula AA2 are selected from the group consisting of the following sub-formulas:

wherein R ²¹ and X ⁰ are as defined in Formula AA2.

Particularly preferred compounds of formula AA3 are selected from the group consisting of the following sub-formulas:

In the formula, R ²¹ , X ⁰ , L ²¹ and L ²² have the meanings given in formula AA3, and X ⁰ is preferably F.

Particularly preferred compounds of formula AA4 are selected from the group consisting of the following sub-formulas:

wherein R ²¹ is as defined in formula AA4.

Compounds of formula BB are preferably selected from the group consisting of:

In the formula, g, A ³¹ , A ³² , R ³¹ , X ⁰ , L ³¹ and L ³² have the meanings given in formula BB and X ⁰ is preferably F. Compounds of formula BB1 and BB2 are particularly preferred.

Particularly preferred compounds of formula BB1 are selected from the group consisting of the following sub-formulas:

In the formula, R ³¹ , X ⁰ , L ³¹ and L ³² have the meanings given in formula BB1 and X ⁰ is preferably F.

Very particularly preferred compounds of formula BB1a are selected from the group consisting of the following sub-formulas:

where R ³¹ is as defined in Formula BB1.

Very particularly preferred compounds of formula BB1b are selected from the group consisting of the following sub-formulas:

where R ³¹ is as defined in Formula BB1.

Particularly preferred compounds of formula BB2 are selected from the group consisting of the following sub-formulas:

^{wherein R 31 , _ _ _ _ _} It's F.

Very particularly preferred compounds of formula BB2 are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of formula BB2b are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of the formula BB2c are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of the formulas BB2d and BB2e are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of the formula BB2f are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of the formula BB2g are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB2.

Very particularly preferred compounds of the formula BB2h are selected from the group consisting of the following sub-formulas:

where R ³¹ and X ⁰ are as defined in Formula BB2.

Very particularly preferred compounds of the formula BB2i are selected from the group consisting of the following sub-formulas:

where R ³¹ and X ⁰ are as defined in Formula BB2.

Very particularly preferred compounds of the formula BB2k are selected from the group consisting of the following sub-formulas:

where R ³¹ and X ⁰ are as defined in Formula BB2.

Alternatively or additionally to the compounds of formula BB1 and/or BB2, the LC medium may also comprise one or more compounds of formula BB3 as defined above.

Particularly preferred compounds of formula BB3 are selected from the group consisting of the following sub-formulas:

wherein R ³¹ is as defined in formula BB3.

Preferably, the LC medium according to the second preferred embodiment has a dielectric anisotropy in the range of -1.5 to +3, in addition to the compounds of formula AA and/or BB, preferably selected from the group of compounds of formula CC as defined above. It contains one or more neutral dielectric compounds having

Particularly preferred compounds of formula CC are selected from the group consisting of the following sub-formulas:

wherein R ⁴¹ and R ⁴² have the meanings given in formula CC and are preferably each independently of the other alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, or 2 to 7 C atoms. represents alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl with C atoms, and L ⁴ is H or F.

Preferably, the LC medium according to the second preferred embodiment is one, additionally or alternatively, with respect to the neutral dielectric compound of formula CC, selected from the group of compounds of formula DD, having a dielectric anisotropy in the range of -1.5 to +3. It contains one or more neutral dielectric compounds.

wherein A ⁴¹ , A ⁴² , Z ⁴¹ , Z ⁴² , R ⁴¹ , R ⁴² and h have the meanings given in Formula CC.

Particularly preferred compounds of formula DD are selected from the group consisting of the following sub-formulas:

wherein R ⁴¹ and R ⁴² have the meanings given in formula DD, R ⁴¹ preferably represents alkyl, and in formula DD1 R ⁴² is preferably alkenyl, particularly preferably -(CH ₂ ) ₂ - CH=CH-CH ₃ , and R ⁴² in the formula DD2 preferably represents alkyl, -(CH ₂ ) ₂ -CH=CH ₂ or -(CH ₂ ) ₂ -CH=CH-CH ₃ .

The compounds of formula AA and BB are preferably added to the LC medium according to the invention in a concentration of 2% to 60%, more preferably 3% to 35% and very particularly preferably 4% to 30% of the mixture as a whole. It is used.

The compounds of formula CC and DD are preferably present in the LC medium according to the invention in an amount of from 2% to 70%, more preferably from 5% to 65%, even more preferably from 10% to 60%, very especially as a total of the mixture. It is preferably used at a concentration of 10%, preferably 15% to 55%.

The combination of the compounds of the above-mentioned preferred embodiments with the polymerized compounds described above results in a consistently high clearing point and high HR value in the LC media according to the invention and at the same time low threshold voltage, low rotational viscosity and very good low-temperature stability, It enables rapid setting of particularly low pretilt angles in PSA displays. In particular, the LC medium shows a significantly shortened response time in PSA displays, especially also the gray-scale response time, compared to media from the prior art.

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

In displays of the VA-type according to the invention, in the switched-off state the molecules in the layer of LC medium are either oriented perpendicularly (homeotropic) to the electrode surface or have an inclined homeotropic orientation. Upon application of an electrical voltage to the electrode, reorientation of the LC molecules occurs with the longitudinal molecular axis parallel to the electrode surface.

The LC medium according to the invention based on compounds with negative dielectric anisotropy according to a first preferred embodiment, especially for use in displays of the PS-VA and PS-UB-FFS types, has a temperature of 20° C. and 1 kHz. It preferably has a negative dielectric anisotropy Δε of -0.5 to -10, especially -2.5 to -7.5.

The birefringence Δn in the LC medium according to the invention for use in displays of the PS-VA and PS-UB-FFS types is preferably less than 0.16, particularly preferably 0.06 to 0.14, very particularly preferably 0.07 to 0.12. am.

In the OCB-type display according to the invention, the molecules in the layer of LC medium have a “bending” orientation. Upon application of electrical voltage, reorientation of the LC molecules occurs with the longitudinal molecular axis perpendicular to the electrode surface.

The LC media according to the invention for use in displays of the PS-OCB, PS-TN, PS-IPS, PS-Posey-VA and PS-FFS types preferably have positive dielectric anisotropy according to the second preferred embodiment. It is based on a compound having , and preferably has a positive dielectric anisotropy Δε of +4 to +17 at 20° C. and 1 kHz.

The birefringence Δn in the LC medium according to the invention for use in displays of the PS-OCB type is preferably between 0.14 and 0.22, particularly preferably between 0.16 and 0.22.

The birefringence Δn in the LC medium according to the invention for use in displays of the PS-TN-, PS-Posey-VA-, PS-IPS- or PS-FFS-type is preferably between 0.07 and 0.15, particularly preferably is 0.08 to 0.13.

The invention based on compounds with positive dielectric anisotropy according to a second preferred embodiment for use in displays of the PS-TN-, PS-Posey-VA-, PS-IPS- or PS-FFS-type. The LC medium according to has a positive dielectric anisotropy Δε at 20° C. and 1 kHz, preferably +2 to +30, particularly preferably +3 to +20.

The LC media according to the invention may also comprise further additives known to the person skilled in the art and described in the literature, such as polymerization initiators, inhibitors, stabilizers, surface-active substances or chiral dopants. They may be polymeric or non-polymeric. The polymerisable additive is therefore considered a polymerisable component or component A). Non-polymerizable additives are therefore considered non-polymerizable components or component B).

In a preferred embodiment, the LC medium contains at least one chiral dopant, preferably in a concentration of 0.01 to 1%, very preferably 0.05 to 0.5%. The chiral dopant is preferably from the group consisting of compounds of Table B below, very preferably R- or S-1011, R- or S-2011, R- or S-3011, R- or S-4011, and R - or S-5011.

In another preferred embodiment, the LC medium contains a racemate of at least one chiral dopant, preferably selected from the chiral dopants mentioned in the preceding paragraph.

Additionally, for example 0 to 15% by weight of pleochroic dyes, also nanoparticles for improving conductivity, conductive salts, preferably ethyldimethyldodecylammonium 4-hexoxybenzoate, tetrabutylammonium tetraphenylborate or crown ethers. complex salts (see, e.g., Haller et al., Mol. Cryst. Liq. Cryst. 24, 249-258 (1973)), or for modifying the dielectric anisotropy, viscosity and/or orientation of the nematic phase. It is possible to add substances to the LC medium. Materials of this type are disclosed, for example, in DE-A 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430 and 28 53 728.

The individual components of the preferred embodiments a)-z) of the LC medium according to the invention are known or can be readily understood from the prior art by a person skilled in the art, since the process for their preparation is based on standard methods disclosed in the literature. can be induced to do so. Corresponding compounds of formula CY are disclosed, for example, in EP-A-0 364 538. Corresponding compounds of formula ZK are disclosed, for example, in DE-A-26 36 684 and DE-A-33 21 373.

LC media that can be used according to the invention can be prepared in the usual way as such, for example by mixing one or more of the above-mentioned compounds with one or more polymerisable compounds as defined above and, optionally, further liquid crystalline compounds and/or additives. It is manufactured. In general, preferred amounts of components used in smaller amounts are dissolved in the components that make up the major constituents, advantageously at elevated temperatures. It is also possible to mix a solution of the components in an organic solvent, for example acetone, chloroform or methanol, and after thorough mixing, remove the solvent again, for example by distillation. The invention further relates to a process for preparing the LC medium according to the invention.

It is clear to a person skilled in the art that the LC medium according to the invention may also comprise compounds in which, for example, H, N, O, Cl, F are replaced by corresponding isotopes such as deuterium, etc. .

The following examples illustrate the invention without limiting it. These examples merely present to those skilled in the art the preferred mixture concept with the compounds preferably used and their respective concentrations and combinations thereof with each other. Additionally, the examples illustrate accessible features and combinations of features.

The following abbreviations are used:

(n, m, z: 1, 2, 3, 4, 5 or 6 in each case independently of each other)

<Table A>

In a preferred embodiment of the invention, the LC medium according to the invention comprises at least one compound selected from the group consisting of the compounds of Table A.

<Table B>

Table B shows chiral dopants that can be added to the LC medium according to the invention.

The LC medium preferably comprises 0 to 10% by weight, especially 0.01 to 5% by weight and particularly preferably 0.1 to 3% by weight of dopants. The LC medium preferably comprises at least one dopant selected from the group consisting of the compounds of Table B.

<Table C>

Table C shows stabilizers that can be added to the LC medium according to the invention.

(where n represents an integer from 1 to 12, preferably 1, 2, 3, 4, 5, 6, 7 or 8, and the terminal methyl group is not shown).

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

<Table D>

Table D shows exemplary compounds that can be used in the LC medium according to the invention, preferably as reactive mesogenic compounds.

In a preferred embodiment of the invention, the mesogenic medium comprises at least one compound selected from the group of compounds in Table D.

Additionally, the following abbreviations and symbols are used:

V ₀ Capacitive threshold voltage at 20°C [V],

n _e anomalous refractive index at 20°C and 589 nm,

n _o Normal refractive index at 20°C and 589 nm,

Δn optical anisotropy at 20°C and 589 nm,

ε _⊥ permittivity perpendicular to the director at 20°C and 1 kHz,

ε _∥ permittivity parallel to the director at 20°C and 1 kHz,

Δε dielectric anisotropy at 20°C and 1 kHz,

cl.p., T(N,I) clear point [℃],

γ ₁ Rotational viscosity at 20°C [mPa·s],

K ₁ “splay” strain modulus at 20°C [pN],

K ₂ “Twist” strain modulus at 20°C [pN],

K ₃ “Bending” strain modulus at 20°C [pN].

Unless explicitly stated otherwise, all concentrations in this application are quoted in weight percentage units and refer to the corresponding total mixture comprising all solid or liquid crystalline components without solvent.

Unless explicitly stated otherwise, all temperature values shown in this application, such as melting point T(C,N), transition from smectic (S) to nematic (N) phase T(S,N) and clearing point T (N,I) are quoted in degrees Celsius (°C). m.p. represents the melting point, and cl.p. is the clearing point. Additionally, C is a crystalline state, N is a nematic phase, S is a smectic phase, and I is an isotropic phase. The data between these symbols represents the transition temperature.

In each case, unless expressly indicated otherwise, all physical properties are described in “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status Nov. 1997, Merck KGaA, Germany] and applied for a temperature of 20° C., Δn is measured at 589 nm and Δε is measured at 1 kHz.

Unless explicitly indicated otherwise, the term “threshold voltage” in the present invention refers to the capacitive threshold (V ₀ ), also known as the Freedericks threshold. In examples, the optical threshold may be quoted for 10% relative contrast (V ₁₀ ), as is generally customary.

Unless otherwise stated, the processes for polymerizing polymerizable compounds in PSA displays described above and below are carried out at a temperature where the LC medium exhibits a liquid crystalline phase, preferably a nematic phase, and most preferably at room temperature.

Unless otherwise stated, methods of fabricating test cells and measuring their electro-optical and other properties are performed by or analogously to methods as described below.

The display used for the measurement of the capacitive threshold voltage consists of two plane-parallel glass outer plates spaced 25 μm apart, each of which has an inner electrode layer and an unrubbed polyimide orientation layer on top, which contains the liquid crystal molecules. Produces a homeotropic edge orientation of

The display or test cell used for the measurement of the tilt angle consists of two plane-parallel glass outer plates spaced 4 μm apart, each of which has an electrode layer on the inside and a polyimide orientation layer on top, wherein the two polyimide layers are rubbed antiparallel to each other, creating a homeotropic edge orientation of the liquid crystal molecules.

The polymerizable compound is polymerized by irradiating a display or test cell with UVA light of a defined intensity for a predetermined period of time and simultaneously by applying a voltage (typically 10 V to 30 V alternating current, 60 Hz to 1 kHz). In the examples, unless otherwise indicated, a metal halide lamp or a high pressure mercury lamp and an intensity of 50 mW/cm ² are used for polymerization. Intensity is measured using a standard UVA meter (Ushio UV-meter high end with UVA sensor).

The tilt angle is determined by a crystal rotation experiment (Autronic-Melchers TBA-105). Small values (i.e. large deviations from the 90° angle) here correspond to large inclinations.

The VHR value is determined as follows: 0.3% of the polymerizable monomer compound is added to the LC host mixture and the resulting mixture is introduced into a VA-VHR test cell containing an unrubbed VA-polyimide orientation layer. The LC-layer thickness d is approximately 6 μm, unless otherwise stated. VHR values are measured before and after UV exposure at 1 V, 60 Hz, 64 μs pulses (measuring instrument: Autronik-Melhus VHRM-105).

Comparative Example 1

Nematic LC host mixture C1 is formulated as follows.

Comparative Example 2

Nematic LC host mixture C2 is formulated as follows.

Example 1

Nematic LC Host Mixture 1 is formulated as follows.

Example 2

Nematic LC Host Mixture 2 is formulated as follows.

Example 3

Nematic LC Host Mixture 3 is formulated as follows.

Example 4

Nematic LC Host Mixture 4 is formulated as follows.

A polymerizable mixture is prepared by adding RM1 according to the present invention to each of the nematic LC host mixtures 1, 2, 3 and 4 at a concentration of 0.3% by weight.

Comparative polymerizable mixtures were prepared by adding prior art RMC1 to each of the nematic LC host mixtures 1, 2, 3 and 4 at a concentration of 0.3% by weight.

Additional comparative polymerizable mixtures are prepared by adding prior art RMC1 to each of the nematic LC host mixtures C1 and C2 at a concentration of 0.3% by weight.

Additional comparative polymerizable mixtures are prepared by adding the highly reactive RM1 according to the invention to each of the nematic LC host mixtures C1 and C2 at a concentration of 0.3% by weight.

Example of use

The polymerizable mixture according to the present invention and the polymerizable comparative mixture are each inserted into the VA e/o test cell. The test cell contains an antiparallel rubbed VA-polyimide orientation layer (JALS-2096-R1). The LC-layer thickness d is approximately 4 μm.

For polymerization of RM, UV light was applied using a broadband pass filter (300 nm < λ < 400 nm) at 10 J (50 mW/cm ² *200 s) while applying a voltage of 14 Vpp (alternating current) to each test cell. investigate.

After UV irradiation, the tilt angles produced in the various polymerizable mixtures are measured by crystal rotation experiments (Autronic-Melhus TBA-105). The inclination angles are presented in Table 1.

Table 1 - Inclination angle

In the comparative polymerizable LC media containing LC host mixture C1 or C2 without the quaterphenyl compound of formula Q, the tilt angle generation was observed in the polymerizable LC media containing LC host mixture 2 or 3 with compound PPGU-3-F of formula Q. It was not that strong compared to the LC medium.

The VHR values of various polymerizable mixtures before and after UV exposure at various UV light intensities (UV range of 300 nm < λ < 400 nm) are measured as described above. VHR values are presented in Table 2.

Table 2 - VHR values

The comparative polymerizable LC medium containing LC host mixture C1, without the quarterphenyl compound of formula Q, showed a significant drop in VHR values after exposure to a UV intensity of 30 J. In contrast, polymerizable LC media containing LC host mixture 1 or 2 with compound PPGU-3-F of formula Q showed a significantly reduced drop in VHR.

Additionally, the LC medium with host mixture 2, which does not contain terphenyl compounds, has a significantly reduced drop in VHR than the LC medium with host mixture 1, which contains terphenyl compounds PYP-2-3 and PYP-2-4. It could be confirmed that it represents . Accordingly, quarterphenyl compounds of formula Q can be used to replace terphenyl compounds in LC host mixtures.

Claims (24)

A liquid crystal (LC) medium comprising at least one compound of formula (I), at least one compound of formula (Q), and at least one compound selected from formulas AN and AY.

In the formula, the individual radicals have the following meanings, identically or differently, in each occurrence, each independently of the other:
Sp ¹ , Sp ² spacer group or single bond,
P ¹ , P ² polymerizable group,
L P-Sp-, F, Cl, -CN, -NO ₂ , -NCO, -NCS, -OCN, -SCN, -C(=O)N(R ^x ) ₂ , -C(=O)Y ¹ , -C(=O)R ^x , -N(R ^x ) ₂ , optionally substituted silyl, optionally substituted aryl or heteroaryl having 5 to 20 ring atoms, or 1 to 25, or 1 to 10 Straight-chain or branched alkyl with a C atom (wherein also one or more non-adjacent CH ₂ groups are each independently of one another in such a way that the O and/or S atoms are not directly connected to each other -C(R ⁰ )=C(R ^{0 0} )- , -C≡C-, -N(R ⁰ )-, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O- and one or more H atoms may be replaced by F, Cl, CN, P- or P-Sp-),
^R _{_} is optionally replaced by -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, wherein one or more H atoms are respectively F, optionally replaced by Cl, P- or P-Sp-),
P a polymerizable group selected from the group consisting of vinyloxy, acrylate, methacrylate, fluoroacrylate, chloroacrylate, oxetane and epoxide,
Sp A spacer group of the formula Sp"- represents len, wherein also one or more non-adjacent CH ₂ groups are each independently of one another -O-, -S-, -NH-, -N(R ⁰ )-, in such a way that the O and/or S atoms are not directly connected to each other. -Si(R ⁰ R ⁰⁰ )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R ⁰⁰ )-CO-O-, -O-CO-N(R ⁰ )-, -N(R ⁰ )-CO-N(R ⁰⁰ )-, -CH=CH- or -C≡C- can be, and X" is -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CO-N(R ⁰ )-, - N(R ⁰ )-CO-, -N(R ⁰ )-CO-N(R ^{0 0} )-, -OCH ₂ -, -CH ₂ O-, -SCH ₂ -, -CH ₂ S-, -CF ₂ O-, -OCF ₂ -, -CF ₂ S-, -SCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -CF ₂ CF ₂ -, -CH=N-, -N=CH -, -N=N-, -CH=CR ⁰ -, -CY ² =CY ³ -, -C≡C-, -CH=CH-CO-O-, -O-CO-CH=CH- or single represents a bond, R ⁰ and R ⁰⁰ each independently represent H or an alkyl having 1 to 20 C atoms, Y ² and Y ³ each independently represent H, F, Cl or CN) or a single Combination,
R ⁰ , R ⁰⁰ H or alkyl with 1 to 20 C atoms,
Y ¹ halogen,
r 0, 1, 2, 3 or 4;
R ^Q Alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms, or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated,
X ^Q
L ^Q1 to L ^Q6 H or F (wherein at least one of L ^Q1 to L ^Q6 is F),

If R ^A1 represents alkenyl with 2 to 9 C atoms, or at least one of rings X, Y and Z represents cyclohexenyl, it is also one of the meanings of R ^A2 ,
R ^A2 Alkyl with 1 to 12 C atoms (wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH-, -CO-, -OCO- in such a way that the O atoms are not directly connected to each other or -COO-),
^Z _{_ _ _ _ _ _} C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O-, or a single bond,
L ¹ -L ⁴ H, F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF ₂ H,
x 1 or 2,
z 0 or 1
However, the LC medium does not contain a terphenyl compound of the formula T below.

(wherein R ⁵ and R ⁶ each independently represent an alkyl having 1 to 12 C atoms, where also 1 or 2 non-adjacent CH ₂ groups are -O-, can be replaced by -CH=CH-, -CO-, -OCO- or -COO-,
are each independently
represents, where L ⁵ represents F or Cl, and L ⁶ represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F or CHF _2. ) 2. The LC medium according to claim 1, wherein in the compound of formula (I) one of Sp ¹ and Sp ² is a single bond and the other is different from a single bond. 3. The compound according to claim 1 or 2, wherein in the compound of formula I one of Sp ¹ and Sp ² is a single bond and the other is -(CH ₂ ) _s1 -X"-, where s1 is an integer from 1 to 6 and , 2. LC medium according to claim 1, comprising at least one compound of formula (I) selected from the following sub-formulas:

In the formula, P ¹ , P ² , L, and r have the meanings of clause 1, and s1 is an integer from 1 to 6. 5. LC medium according to claim 1, 2 or 4, characterized in that it comprises at least one compound of formula (I), selected from the following sub-formulas:

wherein P ¹ , P ² and s1 are as defined in clause 4, s2 is 0 or 1, and L' has one of the meanings provided for L in clause 1. 5. LC medium according to claim 1, 2 or 4, comprising at least one compound of formula AN, selected from the following sub-formulas:


In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl ^* each independently represent a straight-chain alkenyl radical having 2-7 C atoms, CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -. 5. LC medium according to claim 1, 2 or 4, comprising at least one compound of formula AN, selected from the following sub-formulas:

In the formula, m represents 1, 2, 3, 4, 5 or 6, i represents 0, 1, 2 or 3, and R ^b1 represents H, CH ₃ or C ₂ H ₅ . 5. LC medium according to claim 1, 2 or 4, comprising at least one compound of formula AN, selected from the following sub-formulas:
5. LC medium according to claim 1, 2 or 4, characterized in that it comprises at least one compound of formula AY, selected from the following sub-formulas:





In the formula, alkyl and alkyl ^* each independently represent a straight-chain alkyl radical having 1-6 C atoms, alkenyl and alkenyl ^* each independently represent a straight-chain alkenyl radical having 2-7 C atoms, CH ₂ =CH-, CH ₂ =CHCH ₂ CH ₂ -, CH ₃ -CH=CH-, CH ₃ -CH ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₂ -CH=CH-, CH ₃ -(CH ₂ ) ₃ -CH=CH- or CH ₃ -CH=CH-(CH ₂ ) ₂ -. 5. LC medium according to claim 1, 2 or 4, characterized in that it comprises at least one compound of formula Q, selected from the following sub-formulas:

In the formula, R ^Q has one of the meanings of clause 1. 5. LC medium according to claim 1, 2 or 4, comprising at least one compound of formula Q1:

where R ^Q is n-propyl. 2. The LC medium according to claim 1, comprising at least one compound of formula C:

In the formula, the individual radicals have the following meanings, identically or differently, in each occurrence, each independently of the other:
R ^C alkyl, alkoxy, oxaalkyl or alkoxyalkyl having 1 to 9 C atoms, or alkenyl or alkenyloxy having 2 to 9 C atoms, all of which are optionally fluorinated,
X ^C
L ^C1 , L ^C2 H or F, where at least one of L ^C1 and L ^C2 is F. 13. LC medium according to claim 1, 2, 4 or 12, comprising at least one compound of formula C1:

where R ^C is n-propyl. According to paragraph 1,
- a polymerisable component A) comprising at least one polymerisable compound of formula I as defined in claim 1, and
- LC component B) comprising at least one compound selected from the formulas AN and AY as defined in claim 1, at least one compound of the formula Q selected from the following sub-formulas, and optionally at least one further mesogenic or liquid crystalline compound
LC medium characterized in that it contains.

In the formula, R ^Q has one of the meanings of clause 1. 15. LC medium according to claim 14, characterized in that the LC component B) does not contain compounds with terphenyl groups. 16. The LC medium according to claim 1, 2, 4, 12, 14 or 15, comprising at least one compound selected from the formulas CY and PY.

During the ceremony,
a represents 1 or 2,
b represents 0 or 1,
silver represents,
R ¹ and R ² are each, independently of each other, alkyl having 1 to 12 C atoms (wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH-, may be replaced by -CO-, -OCO- or -COO-), or represents an alkyl or alkoxy having 1 to 6 C atoms,
Z ^x and Z ^y are each independently -CH ₂ CH ₂ -, -CH=CH-, -CF ₂ O-, -OCF ₂ -, -CH ₂ O-, -OCH ₂ -, -CO-O- , -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O- or a single bond,
L ¹ -L ⁴ each independently represent F, Cl, OCF ₃ , CF ₃ , CH ₃ , CH ₂ F, CHF ₂ ,
However, the compounds selected from formulas CY and PY are different from the compounds selected from formulas AY. 16. The LC medium according to claim 1, 2, 4, 12, 14 or 15, comprising at least one compound of the formula:

In the formula, individual radicals have the following meanings:
silver represents,
silver represents,
R ³ and R ⁴ each, independently of one another, represent an alkyl having 1 to 12 C atoms, wherein also 1 or 2 non-adjacent CH ₂ groups are -O-, -CH=CH in such a way that the O atoms are not directly connected to each other. may be replaced by -, -CO-, -O-CO- or -CO-O-,
Z ^y is -CH ₂ CH ₂ -, -CH=CH-, -CF ₂ O-, -OCF ₂ -, -CH ₂ O-, -OCH ₂ -, -CO-O-, -O-CO-, -C ₂ F ₄ -, -CF=CF-, -CH=CH-CH ₂ O- or represents a single bond,
However, the compound selected from the formula ZK is different from the compound selected from the formula AN. 16. LC medium according to claim 1, 2, 4, 12, 14 or 15, wherein the polymerisable compound of formula (I) is polymerized. LC display comprising the LC medium defined in any one of claims 1, 2, 4, 12, 14 and 15. 20. The LC display according to claim 19, which is a PSA type display. 21. The LC display of claim 20, which is a PS-VA, PS-OCB, PS-IPS, PS-FFS, PS-UB-FFS, PS-posi-VA or PS-TN display. 15. An LC display comprising the LC medium defined in any one of claims 1, 2, 4, 12, 14 and 15,
Two substrates, at least one of which is transparent, an electrode provided on each substrate or two electrodes provided on only one of the substrates, and claims 1, 2, 4, 12, and 14 located between the substrates. and an LC media layer as defined in claim 15, wherein the polymerisable compound polymerizes between the substrates of the display. A method of manufacturing an LC display according to claim 22, comprising providing the LC medium between the substrates of the display and polymerizing a polymerizable compound. One or more compounds of the formula AN and/or AY as defined in claim 1 and one or more compounds of the formula Q as defined in claim 1, and optionally one or more compounds of the formula C as defined in claim 12, or at least one compound of the formula C as defined in claim 14. Comprising the step of mixing the defined LC component B) with one or more compounds of formula I as defined in any one of claims 1, 2 and 4, and optionally further LC compounds and/or additives. , a process for producing an LC medium according to any one of claims 1, 2, 4, 12, 14 and 15.