TW202400757A - Liquid crystalline medium - Google Patents

Abstract

The invention relates to a liquid-crystalline medium having a nematic phase comprising one or more compounds of formula I wherein the parameters have the meaning given in the text, to novel compounds under formula I, the use thereof in an electro-optical display, particularly in an active-matrix display based on the IPS or FFS effect which is fast and energy-saving, to displays of this type which contain a liquid-crystalline medium of this type.

Description

liquid crystal medium

The present invention relates to a liquid crystal medium with a nematic phase, which contains one or more furan derivative compounds of formula I. wherein the parameters have the meanings given herein below with respect to the novel compounds according to formula I and their use in electro-optical displays, in particular based on IPS or fringe field switching (FFS) using dielectrically positive liquid crystals. ) effect in active matrix displays, and related to this type of display containing this type of liquid crystal medium.

For this purpose, dielectrically positive liquid crystals are used, which contain one or more compounds that have a high dielectric constant both parallel to the molecular director and perpendicular to the molecular director, resulting in a large average dielectric constant and high dielectric ratio, and preferably simultaneously produce relatively small dielectric anisotropy. The liquid crystal medium optionally additionally contains dielectrically negative compounds, dielectrically neutral compounds or both. Liquid crystal media are used for uniform (i.e. planar) initial alignment. The liquid crystal medium according to the present invention has positive dielectric anisotropy and contains compounds having a large dielectric constant both parallel and perpendicular to the molecular director.

The medium is characterized by particularly high transmission rates and reduced response times in the respective display, due to a unique combination of its physical properties, in particular by its high elastic constant value, in particular by its high k ₁₁ and its excellent Low rotational viscosity (γ ₁ ) to elastic constant (k ₁₁ ) ratio (γ ₁ /k ₁₁ ) is achieved. This also results in excellent performance in displays according to the invention.

IPS and FFS displays using dielectric positive liquid crystals are well known in the art and have been widely used in various types of displays (such as desktop monitors and televisions) as well as gaming, mobile and automotive applications.

However, recently, IPS, and specifically FFS displays using dielectric negative liquid crystals have been widely adopted. The latter is sometimes also called UB-FFS (Ultra Bright FFS). Such a display is disclosed for example in US 20130207038 A1. These displays are characterized by significantly improved transmission rates compared to previously used IPS displays and FFS displays using dielectric positive liquid crystals. However, such displays using conventional dielectric negative liquid crystals have the serious disadvantage of requiring higher operating voltages than respective displays using dielectric positive liquid crystals. The liquid crystal medium used in UB-FFS has a dielectric anisotropy of -0.5 or lower and preferably -1.5 or lower.

The liquid crystal medium used for high brightness FFS (HB-FFS) has a dielectric anisotropy of 0.5 or higher and preferably 1.5 or higher. Liquid crystal media for HB-FFS containing both dielectric negative and dielectric positive liquid crystal compounds (respectively mesogen compounds) are disclosed in, for example, US 20130207038 A1. These media provide considerable ε _⊥ and ε _av values. However, its ratio (ε _⊥ / Δε) is already relatively small.

However, according to the present application, the IPS or FFS effect is better with a dielectric positive liquid crystal medium with uniform alignment.

Industrial applications of this effect in electro-optical display components require LC phases that must meet various requirements. Of particular importance here is the chemical resistance against moisture, air and physical influences such as heat, radiation in the infrared, visible and ultraviolet regions and direct current (DC) and alternating current (AC) electric fields.

In addition, an industrially usable LC phase requires a liquid crystalline mesophase within a suitable temperature range and low viscosity.

The series of compounds with liquid crystalline mesophases disclosed so far do not include a single compound that meets all of these requirements. Therefore, mixtures of two to 25, preferably three to 18 compounds are generally prepared to obtain materials that can be used as LC phases.

Matrix liquid crystal displays (MLC displays) are known. Nonlinear elements that can be used for individual switching of individual pixels are, for example, active elements (ie transistors). The term "active matrix" is subsequently used, in which thin film transistors (TFTs) are generally used, usually arranged on a glass plate as a substrate.

The difference between the two technologies is: TFTs containing compound semiconductors such as CdSe or metal oxides such as ZnO, or TFTs based on polycrystalline and especially amorphous silicon. The latter technology currently has the greatest commercial importance worldwide.

A TFT matrix is applied inside one of the display's glass panes, while the other glass pane carries transparent counter electrodes inside it. Compared with the size of pixel electrodes, TFTs are extremely small and have almost no adverse effects on images. This technology can also be extended to full-color displays, where a mosaic of red, green and blue filters is arranged in such a way that the filter elements are opposite each switchable pixel.

The TFT displays that have been mainly used so far usually operate with crossed polarizers in transmission and are backlit. For TV applications, ECB (or VAN) units or FFS units are used, while monitors usually use IPS units or TN (twisted nematic) units, and notebooks, laptops and mobile applications usually use TN, VA or FFS unit.

The term MLC display herein covers any matrix display with integrated nonlinear elements, that is, in addition to the active matrix, the display also has passive elements, such as varistors or diodes (MIM = Metal-Insulator-Metal).

This type of MLC display is particularly suitable for TV applications, monitors and notebook computers or for displays with high information density, such as those used in automobile manufacturing or aircraft construction. In addition to issues regarding the angle dependence of contrast and response time, difficulties arise in MLC displays because the specific resistance of the liquid crystal mixture is not high enough [TOGASHI, S., SEKIGUCHI, K., TANABE, H., YAMAMOTO, E. , SORIMACHI, K., TAJIMA, E., WATANABE, H., SHIMIZU, H., Proc. Eurodisplay 84, September 1984: A 210-288 Matrix LCD Controlled by Double Stage Diode Rings, pp. 141 et seq., Paris; STROMER, M., Proc. Eurodisplay 84, September 1984: Design of Thin Film Transistors for Matrix Addressing of Television Liquid Crystal Displays, pp. 145 et seq., Paris]. As the resistance decreases, the contrast ratio of the MLC display deteriorates. Since the specific resistance of the liquid crystal mixture typically decreases over the lifetime of an MLC display due to interaction with the inner surface of the display, high (initial) resistance is extremely important for displays that must have acceptable resistance values over long periods of operation.

In addition to IPS displays (for example: Yeo, S.D., Document 15.3: "An LC Display for the TV Application", SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume II, Pages 758 and 759) and early In addition to the well-known TN displays, displays using the ECB effect have been established as so-called vertically aligned nematic (VAN) displays, which are currently one of the most important three latest types of liquid crystal displays, especially for television applications.

The most important design that can be mentioned here is: multi-domain vertical alignment (MVA) (for example: Yoshide, H. et al., Document 3.1: "MVA LCD for Notebook or Mobile PCs..." , SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume I, pages 6 to 9, and Liu, C.T. et al., Document 15.1: "A 46-inch TFT-LCD HDTV Technology...", SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume II, pages 750 to 753), patterned vertical alignment (PVA) (for example: Kim, Sang Soo, Document 15.4: "Super PVA Sets New State-of-the-Art for LCD-TV", SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume II, pages 760 to 763) and advanced super view (ASV) ) (For example: Shigeta, Mitzuhiro and Fukuoka, Hirofumi, Document 15.2: "Development of High Quality LCDTV", SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume II, pages 754 to 757). More modern versions of the VA effect are so-called photo-alignment VA (PAVA) and polymer-stabilized VA (PSVA).

For example, Souk, Jun, SID Seminar 2004, Seminar M-6: “Recent Advances in LCD Technology”, Seminar Lecture Notes, M-6/1 to M-6/26, and Miller, Ian, SID Seminar 2004, Seminar M -7: General form of comparative technology in "LCD-Television", Seminar Lecture Notes, M-7/1 to M-7/32. Although the response time of modern ECB displays has been significantly improved by using overdrive addressing methods, for example: Kim, Hyeon Kyeong et al., Paper 9.1: "A 57-in. Wide UXGA TFT-LCD for HDTV Application", SID 2004 International Symposium, Digest of Technical Papers, XXXV, Volume I, pages 106 to 109. However, the response time to achieve video compatibility, especially in grayscale switching, is still a problem that has not yet been satisfactorily solved.

ECB displays, such as ASV displays, use a liquid crystal medium with negative dielectric anisotropy (Δε), while TN and all conventional IPS displays to date use a liquid crystal medium with positive dielectric anisotropy. However, there is currently an increasing demand for IPS and FFS displays utilizing dielectric negative liquid crystal media.

In this type of LCD, liquid crystal is used as a dielectric whose optical properties change reversibly upon application of a voltage.

Since in normal displays (i.e. also in displays according to the effects mentioned) the operating voltage should be as low as possible, a liquid crystal medium is used which usually consists mainly of liquid crystal compounds, all of which have the same dielectric Electrical anisotropy sign and has the highest possible dielectric anisotropy value. In general, at most a relatively small proportion of neutral compounds are used and, if possible, compounds with the opposite sign of the dielectric anisotropy of the medium are not used. Therefore, in the case of liquid crystal media with negative dielectric anisotropy, for example for ECB or UB-FFS displays, compounds with negative dielectric anisotropy are mainly used. The respective liquid crystal media used usually consist mainly of liquid crystal compounds with negative dielectric anisotropy.

In the media used in accordance with the present application, large amounts of dielectrically positive liquid crystal compounds are typically used and typically only very small amounts or even no dielectrically negative compounds are used since liquid crystal displays are generally expected to have the lowest possible addressing voltage. The low addressing voltage enables the display to be energy efficient and have fast switching times. At the same time it may be advantageous to use small amounts of dielectrically neutral compounds.

Liquid crystal media with positive dielectric anisotropy have been disclosed for IPS and FFS displays.

Compounds of the following formula and similar 2-alkyl-furan compounds are disclosed in EP 1013649 A1 as suitable for liquid crystal materials.

2-Phenyl-5-trifluoromethylfuran and its derivatives are disclosed as coupling reaction products in the publication Y. Wang et al., Angew. Chem. Int. Ed. 2017, 56, 1810-1814.

The phase range of the liquid crystal mixture must be broad enough for the intended application of the display. The response time of the liquid crystal medium in the display should be as short as possible, especially for video, animation simulation and game applications. This is especially important for displays used in television or multimedia applications. In order to improve the response time, it has been repeatedly proposed in the past to optimize the rotational viscosity (γ ₁ ) of the liquid crystal medium, that is, to achieve the medium with the lowest possible rotational viscosity. However, the results achieved here are not sufficient for many applications and other optimization methods need to be found.

Adequate stability of the media against extreme loads, especially UV exposure and heating, is extremely important. In particular, this may be crucial in the case of displays applied in mobile devices such as mobile phones.

In addition to relatively poor transmission rates and relatively long response times, the MLC displays disclosed so far also have other shortcomings. Such disadvantages are, for example, their relatively low contrast ratio; their relatively high viewing angle dependence; and the difficulty in reproducing grayscale in such displays, especially when viewed from oblique viewing angles; and their insufficient VHR and their insufficient service life. Desired improvements are needed in the display's transmission rate and its response time in order to improve its energy efficiency and accordingly enable it to display animations quickly.

Therefore, there is still a great demand for MLC displays with extremely high specific resistance, as well as a large operating temperature range, a short response time and a relatively low critical voltage, with the help of which various grayscales can be produced and which are particularly Good and stable VHR.

The object of the present invention is to provide MLC displays not only for monitor and TV applications, but also for mobile applications such as phones and navigation systems, which displays are based on ECB, IPS or FFS effects and do not have the above indicated disadvantages, or only have these disadvantages to a lesser extent, and at the same time have extremely high specific resistance values. Specifically, for mobile phones and navigation systems, it is necessary to ensure that they can operate in extremely high and extremely low temperatures.

Surprisingly, it has been found that it is possible to achieve a liquid crystal display that has a low threshold voltage and a short response time, especially in IPS and FFS displays, a sufficiently wide nematic phase, a favorable birefringence (Δn), and at the same time, if When used in these display elements, nematic liquid crystal media have high transmission rate, high contrast ratio, good stability against decomposition caused by heating and UV exposure, and stable high VHR. These nematic liquid crystal media contain at least One compound of formula I, preferably two or more compounds of formula I, preferably one or more further compounds, preferably two or more compounds selected from the group of compounds of formula T, formula II and formula III, and /or one or more compounds, preferably two or more compounds, selected from the group of formula IV and/or formula V.

This type of media is particularly useful in electro-optical displays with active matrix addressing for IPS or FFS displays.

The medium according to the invention preferably additionally contains one or more compounds selected from the group of compounds of formula T, formula II and formula III, preferably one or more compounds of formula II, more preferably another one or more compounds of formula III, and most preferably Another one or more compounds selected from the group of compounds of formula IV and formula V, and more preferably one or more compounds selected from the group of compounds of formula VI to formula IX (all chemical formulas are defined below).

The mixture according to the invention exhibits a very wide nematic range with a clearing point ≥70°C, a very favorable capacitance critical value, a relatively high retention value and at the same time exhibits good low temperature stability at -20°C and -30°C, and Very low rotational viscosity. Furthermore, the mixtures according to the invention are characterized by a good clearing point to rotational viscosity ratio and a relatively high positive dielectric anisotropy.

It has been surprisingly found that FFS-type LCs using liquid crystals with positive dielectric anisotropy can be realized using specially selected liquid crystal media. These media are characterized by specific combinations of physical properties. The most decisive one is its high elastic constant value, especially its excellent low rotational viscosity (γ ₁ ) to elastic constant (k ₁₁ ) ratio (γ ₁ /k ₁₁ ). In addition to this, it exhibits high ε _⊥ resulting in good transmission rates.

The liquid crystal medium of the present invention contains a) one or more compounds of formula I, the concentration of which is preferably in the range of 1% to 40%, more preferably in the range of 2% to 30%, especially preferably in the range of 3% to 20% , wherein R ¹ is an alkyl group having 1 to 15 C atoms, wherein one or more CH ₂ groups including terminal C atoms in this group may each be independently passed through - C≡C-、-CH=CH-、 , -O-, -S-, -(CO)-O-, -O-(CO)-, and wherein in addition, one or more H atoms may be replaced by F or Cl, A ¹ express Preferably L ¹ , L ² Each independently represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , OCH ₃ , CH ₂ F, CHF ₂ , preferably F, Y CH ₃ , CH ₂ CH ₃ , A ⁰ , on each occurrence independently of one another, represents phenylene-1,4-diyl, wherein in addition one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH ₃ , CHF ₂ , CH ₂ F, OCH ₃ , OCHF ₂ or OCF ₃ substitution; cyclohexane-1,4-diyl, wherein in addition, one or two non-adjacent CH ₂ groups may be substituted independently of each other O and/or S are substituted and one or more H atoms may be substituted by F; cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2 ] Octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioctane-2,5-diyl group, Z ⁰ independently of each other, the same or different, represents a single bond, -CH ₂ O-, -(CO)O-, -CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -CF ₂ CF ₂ - , -CH ₂ CF ₂ -, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -CH=CH-, -CH=CF-, -CF=CF- or -C≡C-, where asymmetry The bridge bond can be inserted in any orientation, X ¹ F, Cl, -CF ₃ or -OCF ₃ , preferably -CF ₃ , and n represents 0, 1 or 2, preferably 0. and preferably one or more additional compounds selected from the group of compounds according to the following conditions b) to f): b) one or more preferably dielectrically neutral compounds of formula T The individual groups have the following meanings: R ¹ and R ² represent H, F, Cl, Br, -CN or a straight-chain or branched alkyl group with 1 to 12 C atoms, which additionally includes one of the terminal C atoms. or multiple CH ₂ groups may each independently pass through -CH=CH-, -C≡C-, in such a way that the O or S atoms are not directly connected to each other , -O-, -S-, -CO-, -CO-O-, -O-CO-, and wherein in addition, one or more H atoms may be replaced by F or Cl, L ¹ H or CH ₃ , Preferably H, A ⁰ means wherein the (fluoro)phenylene ring may optionally be substituted by one or two methyl and/or ethyl groups, A ¹ , independently of each other, represent phenylene-1,4-diyl, wherein in addition, one or two CH groups can be replaced by N and one or more H atoms can be replaced by halogen, CN, CH ₃ , CHF ₂ , CH ₂ F, OCH ₃ , OCHF ₂ or OCF ₃ substitution; cyclohexane-1,4-diyl, wherein in addition, one or two non-adjacent CH ₂ groups can be independently substituted by O and/or S Replacement and one or more H atoms can be replaced by F; cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1 ,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dihexane-2,5-diyl, m in each represent 0, 1 or 2 independently of each other, preferably 1, c) one or more preferably dielectrically positive compounds, which are selected from the group of compounds of formula II and formula III, preferably each having Compounds with a dielectric anisotropy greater than 3 are preferably one or more compounds of formula II: wherein R ² is an alkyl group having 1 to 15 C atoms, wherein one or more CH ₂ groups including terminal C atoms in this group may each be independently passed through - C≡C-、-CH=CH-、 , -O-, -S-, -(CO)-O-, -O-(CO)-replacement, and wherein in addition, one or more H atoms can be replaced by F or Cl; or H, preferably represents having Alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy with 1 to 7 C atoms; alkenyl, alkenyloxy, alkoxyalkyl, fluorinated alkenyl with 2 to 7 C atoms ; Cycloalkyl with 3 to 5 C atoms; cycloalkylalkyl; cycloalkylalkoxy and preferably alkyl, cyclopropylcyclopentyl or alkenyl, and represent independently of each other on each occurrence , wherein the (fluoro)phenylene ring may optionally be substituted by one or two methyl and/or ethyl groups, Preferably , L ²¹ and L ²² represent H or F, L ^2a H or CH ₃ , preferably H, X ² represents halogen, halogenated alkyl or alkoxy group with 1 to 3 C atoms or 2 or 3 C atoms. The halogenated alkenyl or alkenyloxy group is preferably F, Cl, -OCF ₃ , -O-CH ₂ CF ₃ , -O-CH=CF ₂ or -CF ₃ , and most preferably F, Cl, -O- CH=CF ₂ or -OCF ₃ , m represents 0, 1, 2 or 3, preferably 1 or 2 and especially preferably 2, R ³ has an alkyl group of 1 to 15 C atoms, wherein this group One or more CH ₂ groups including terminal C atoms can be independently connected to each other through -C≡C-, -CH=CH-, , -O-, -S-, -(CO)-O-, -O-(CO)-replacement, and wherein in addition, one or more H atoms can be replaced by F or Cl; or H, preferably represents having Alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy with 1 to 7 C atoms; alkenyl, alkenyloxy, alkoxyalkyl, fluorinated alkenyl with 2 to 7 C atoms ; Cycloalkyl having 3 to 5 C atoms; cycloalkylalkyl; cycloalkylalkoxy and preferably alkyl, cyclopropyl, cyclopentyl or alkenyl, and on each occurrence independently of each other as , Wherein the (fluoro)phenylene ring may be substituted by one or two methyl and/or ethyl groups, preferably , or L ³¹ and L ³² independently represent H or F, preferably L ³¹ represents F, L ^3a H or CH ₃ , preferably H, X ³ represents halogen, a halogenated alkyl group with 1 to 3 C atoms Or alkoxy or halogenated alkenyl or alkenyloxy with 2 or 3 C atoms, preferably F, Cl, -OCF ₃ , -OCHF ₂ , -O-CH ₂ CF ₃ , -O-CH=CF ₂ or -CF ₃ , and preferably F, Cl, -O-CH=CF ₂ , -OCHF ₂ or -OCF ₃ , Z ³ represents -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -COO- , trans -CH=CH-, trans -CF=CF-, -CH ₂ O- or single bond, preferably -CH ₂ CH ₂ -, -COO-, trans -CH=CH- or single bond And preferably -COO-, trans -CH=CH- or a single bond, and n represents 0, 1, 2 or 3, preferably 1, 2 or 3 and especially preferably 1, d) one or more Dielectric neutral compounds selected from the group of formula IV and formula V: wherein R ⁴¹ and R ⁴² independently have the meanings indicated above according to R ³ of Formula III, preferably R ⁴¹ represents an alkyl group and R ⁴² represents an alkyl group, cyclopropyl group, cyclopentyl group or alkoxy group , or R ⁴¹ represents an alkenyl group and R ⁴² represents an alkyl group, and independent of each other and if Appears twice, then these groups also represent independently of each other , wherein the (fluoro)phenylene ring may optionally be substituted by one or two methyl and/or ethyl groups, Better and one or more of express, Z ⁴¹ and Z ⁴² are independent of each other and if Z ⁴¹ appears twice, these groups also independently represent -CH ₂ CH ₂ -, -COO-, trans- CH=CH-, trans -CF= CF-, -CH ₂ O-, -CF ₂ O-, -C≡C- or single bond, preferably one or more of them represents a single bond, p represents 0, 1 or 2, preferably 0 or 1 , and R ⁵¹ and R ⁵² , independently of each other, have one of the meanings given for R ⁴¹ and R ⁴² , and preferably represent an alkyl group having 1 to 7 C atoms, preferably n-alkyl, Particularly preferred is an n-alkyl group having 1 to 5 C atoms; an alkoxy group having 1 to 7 C atoms is particularly preferred, and particularly preferred is an n-alkyl group having 2 to 5 C atoms. Oxygen; alkoxyalkyl, alkenyl or alkenoxy having 2 to 7 C atoms, preferably 2 to 4 C atoms, preferably alkenyloxy, to , If present, each represents independently of the other , wherein the (fluoro)phenylene ring may optionally be substituted by one or two methyl and/or ethyl groups, Preferably , Z ⁵¹ to Z ⁵³ each independently represent -CH ₂ -CH ₂ -, -CH ₂ -O-, -CH=CH-, -C≡C-, -COO- or a single bond, preferably -CH ₂ -CH ₂ -, -CH ₂ -O- or a single bond and particularly preferably a single bond, i and j each independently represent 0 or 1, (i + j) preferably represents 0, 1 or 2, more preferably is 0 or 1, and e) one or more dielectric negative compounds selected from the group of formula VI to formula IX: Wherein R ⁶¹ represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably a straight chain alkyl group, more preferably a n-alkyl group, most preferably a propyl or pentyl group; having 2 to 7 C atoms The unsubstituted alkenyl group is preferably a linear alkenyl group, especially preferably an unsubstituted alkoxy group having 2 to 5 C atoms; an unsubstituted alkoxy group having 1 to 6 C atoms; and an unsubstituted alkoxy group having 2 to 6 C atoms. unsubstituted alkenyloxy; or C _{3 - 5} -cycloalkyl-(CH ₂ ) _{0 - 1} , R ⁶² represents an unsubstituted alkyl group with 1 to 7 C atoms, with 1 to 6 Unsubstituted alkoxy group of C atoms, C _{3 - 5} cycloalkyloxy group or unsubstituted alkenyloxy group with 2 to 6 C atoms, and L ⁶¹ and L ⁶² are independently H or methyl , preferably H, l represents 0 or 1, R ⁷¹ represents an unsubstituted alkyl group with 1 to 7 C atoms, preferably a straight-chain alkyl group, more preferably a n-alkyl group, most preferably a propyl group Or pentyl; unsubstituted alkenyl with 2 to 7 C atoms, preferably straight chain alkenyl, especially preferably with 2 to 5 C atoms; or C _{3 - 5} cycloalkyl - (CH ₂ ) _{0 - 1} , R ⁷² represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms; having 1 to 6 C atoms, preferably 1, 2, 3 or Unsubstituted alkoxy group with 4 C atoms; or unsubstituted alkenoxy group with 2 to 6 C atoms, preferably 2, 3 or 4 C atoms, and L ⁷¹ , L ⁷² independently is H or methyl, preferably H, and represent independently , R ⁸¹ represents an unsubstituted alkyl group with 1 to 7 C atoms, preferably a straight chain alkyl group, more preferably a n-alkyl group, most preferably a propyl or pentyl group; Unsubstituted alkenyl, preferably linear alkenyl, especially preferably having 2 to 5 C atoms; or C _{3 - 5} cycloalkyl - (CH ₂ ) _{0 - 1} , R ⁸² represents having 1 to 7 Unsubstituted alkyl group having 1 to 6 C atoms, preferably 1, 2, 3 or 4 C atoms; unsubstituted alkoxy group having 1 to 6 C atoms, preferably 1, 2, 3 or 4 C atoms ; Unsubstituted alkenyloxy group with 2 to 6 C atoms, preferably 2, 3 or 4 C atoms; or C _{3 - 5} cycloalkoxy group, L ⁸¹ and L ⁸² are independently H or methane Base, preferably H, express , Preferably , Better for , Z ⁸ represents -(C=O)-O-, -CH ₂ -O-, -CF ₂ -O- or -CH ₂ -CH ₂ -, preferably -(C=O)-O- or -CH ₂ -O-, and o represent 0 or 1, R ⁹¹ and R ⁹² independently have the meanings given above for R ⁷² , R ⁹¹ preferably represents 2 to 5 C atoms, preferably 3 to An alkyl group with 5 C atoms, R ⁹² preferably represents an alkyl group or alkoxy group with 2 to 5 C atoms, more preferably an alkoxy group with 2 to 4 C atoms; or an alkoxy group with 2 to 4 C atoms. Alkenyloxy group of atoms. express , p and q independently represent 0 or 1, and (p + q) preferably represents 0 or 1, if express , Then preferably, p = q = 1, f) one or more compounds of formula to 10% range, in express , L independently represents H or CH ₃ or CH ₂ CH ₃ , preferably H, represent independently of each other on each occurrence , Preferably , n represents 1 or 2, preferably 1, R ¹ represents an alkyl group, alkoxy group, fluorinated alkyl group or fluorinated alkoxy group preferably having 1 to 7 C atoms; Alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl; C _{3 - 5} -cycloalkyl; C _{3 - 5} -cycloalkyl-alkyl; C _{3 - 5} -cycloalkyl-alkoxy Group, preferably alkyl, alkoxy, alkenyl or alkenyloxy, more preferably alkyl, alkenyl, alkoxy or alkenyloxy and most preferably alkyl, and X ¹ represents F, Cl, Fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyloxy, the latter four groups preferably have 1 to 4 C atoms, preferably F, Cl, CF ₃ or OCF ₃ , wherein each ring and preferably the phenylene ring may each be substituted optionally with one or two alkyl groups, preferably with methyl and/or ethyl groups, preferably with one methyl group, and g) likewise optionally, preferably Essentially, alternatively or in addition, one or more compounds of formula XI: in express , L independently represents H or CH ₃ or CH ₂ CH ₃ , preferably H, express , Preferably , n represents 0 or 1, R ¹¹ and R ¹² independently represent an alkyl group, an alkoxy group, a fluorinated alkyl group or a fluorinated alkoxy group preferably having 1 to 7 C atoms, in which one CH ₂ group can Replaced by 1,2-cyclopropyl, 1,3-cyclopentyl or 1,3-cyclopentenyl; alkenyl, alkenyloxy, alkoxyalkyl with 2 to 7 C atoms Or fluorinated alkenyl, and preferably alkyl, alkoxy, alkenyl or alkenyloxy, most preferably alkyl, alkoxy or alkenyloxy, wherein each ring and the preferred phenylene ring can be Each is substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group, and compounds of formula X are not included.

Optionally, the medium according to the present application contains one or more compounds of formula L, the concentration of which is preferably in the range of 1% to 40%, more preferably in the range of 2% to 30%, especially preferably in the range of 3% to 20% within the range, where R ^L1 and R ^L2 independently represent an alkyl group with 1 to 15 C atoms, wherein one or more CH ₂ groups in these groups, preferably a CH ₂ group, can make O atoms mutually exclusive The ways that are not directly connected each independently pass through -C≡C-, -CF ₂ O-, -OCF ₂ -, -O-, -(CO)-O-, -O-(C=O)-, ring - Propylene glycol, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclopentylene, preferably replaced by cyclopropylene or 1,3-cyclopentylene , an alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl group with 2 to 7 C atoms, and one or more of the H atoms may be replaced by halogen, and Y ^L1 and Y ^L2 , the same or different represents H, F or Cl, preferably at least one of Y ^L1 and Y ^L2 is H, preferably Y ^L2 is H, and most preferably Y ^L1 and Y ^L2 are H.

The liquid crystal medium according to the present application preferably has a nematic phase.

Throughout this application and in particular with respect to the definitions of R ¹ , R ² , R ³ , R ⁴¹ , R ⁵¹ , R ^{L1 ,} etc. and R ^L2 , alkyl means an alkyl group which may be straight or branched. Each of these groups is preferably straight chain, and preferably has 1, 2, 3, 4, 5, 6, 7 or 8 C atoms, and is accordingly preferably methyl, ethyl, n- Propyl, n-butyl, n-pentyl, n-hexyl or n-heptyl.

In the case where alkyl means branched chain alkyl, it preferably means 2-alkyl, 2-methylalkyl or 2-(2-ethyl)-alkyl, preferably 2-butyl ( =1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, especially 2-methylbutyl base, 2-methylbutoxy 4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl, 2-decyl and 2-dodecyl. Preferably these groups are 2-hexyl and 2-octyl.

The respective branched chain groups that give rise to chiral compounds are also referred to in this application as chiral groups. Particularly preferred chiral groups are 2-alkyl, 2-alkoxy, 2-methylalkyl, 2-methylalkoxy, 2-fluoroalkyl, 2-fluoroalkoxy, 2- (2-ethynyl)-alkyl, 2-(2-ethynyl)-alkoxy, 1,1,1-trifluoro-2-alkyl and 1,1,1-trifluoro-2-alkoxy.

For example, particularly preferred chiral groups are 2-butyl (=1-methylpropyl), 2-methylbutyl, 2-methylpentyl, 3-methylpentyl, 2- Ethylhexyl, 2-propylpentyl, especially 2-methylbutyl, 2-methylbutoxy, 2-methylpentyloxy, 3-methylpentyloxy, 2-ethylhexyloxy base, 1-methylhexyloxy, 2-octyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methylpentyl, 4-methylhexyl, 2-hexyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methoxyoctyloxy, 6-methyloctyloxy, 6-methyloctyloxy, 5- Methylheptyloxycarbonyl, 2-methylbutyloxy, 3-methylpentyloxy, 4-methylhexyloxy, 2-chloropropyloxy, 2-chloro-3-methyl Butyloxy, 2-chloro-4-methylpentyloxy, 2-chloro-3-methylpentyloxy, 2-methyl-3-oxopentyl, 2-methyl-3- Oxahexyl, 1-methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy, 1-butoxypropyl -2-oxy, 2-fluorooctyloxy, 2-fluorodecanyloxy, 1,1,1-trifluoro-2-octyloxy, 1,1,1-trifluoro-2-octyl, 2 -Fluoromethyloctyloxy. Excellent ones are 2-hexyl, 2-octyl, 2-octyloxy, 1,1,1-trifluoro-2-hexyl, 1,1,1-trifluoro-2-octyl and 1,1,1 -Trifluoro-2-octyloxy.

Throughout this application, alkenyl means an alkenyl group which may be linear or branched and is preferably linear and preferably has 2, 3, 4, 5, 6 or 7 or 8 C atoms. It is preferably vinyl, 1- E -alkenyl or 3- E -alkenyl, and the most preferred is vinyl, 1- E -propenyl, 1- E -butenyl, 1- E -pentenyl , 3-butenyl or 3- E -pentenyl.

The compounds of the general formulas I, L, T and II to Prepared by methods known per se, specifically under reaction conditions known and suitable for such reactions. Variants known per se but not mentioned in more detail here may be used.

Compounds of formula I can be synthesized as disclosed in Angew. Chem. Int. Ed. 2017, 56, 1810-1814 and as in the Synthesis Examples.

Preferably, the compound of general formula T is synthesized as disclosed in WO 2012/013281 A1.

The invention further relates to a liquid crystal display containing a liquid crystal medium according to the invention, in particular an IPS or FFS display, particularly preferably an FFS or SG-FFS display. The present invention further relates to an IPS or FFS type liquid crystal display including a liquid crystal cell, which liquid crystal cell is composed of: two substrates, at least one of which is light-transmissive and at least one of which has an electrode layer; and between the substrates A liquid crystal medium layer, the liquid crystal medium comprising a polymeric component and a low molecular weight component, wherein the polymeric component can be polymerized by polymerizing one or more polymerizable compounds in the liquid crystal medium between the substrates of the liquid crystal cell, preferably applied simultaneously voltage, and wherein the low molecular weight component is the liquid crystal mixture according to the present invention as described above and below.

The display according to the present invention is preferably addressed by an active matrix LCD (AMD), preferably by a thin film transistor (TFT) matrix. However, the liquid crystals according to the invention can also be used in an advantageous manner in displays with other known addressing methods.

The invention further relates to a process for preparing a liquid-crystalline medium according to the invention by combining one or more compounds of the formula I or subformulas thereof with one or more low molecular weight liquid-crystalline compounds or liquid-crystalline mixtures, and optionally with Other liquid crystal compounds and/or additives are mixed.

The following meanings apply to the above and below: Unless otherwise indicated, the term "FFS" is used to refer to both FFS and SG-FFS displays. The term "mesogen group" is known to those skilled in the art and described in the literature, and means a liquid crystal that contributes substantially to low molecular weight or polymeric materials due to the anisotropy of its attractive and repulsive interactions. (LC) phase generated group. The compound containing a mesogen group (mesogen compound) itself does not necessarily have a liquid crystal phase. It is also possible that mesogen compounds exhibit liquid crystalline phase behavior only after mixing with other compounds and/or after polymerization. Typical mesogen groups are, for example, rigid rod-shaped or disk-shaped units. An overview of terms and definitions used in connection with mesogens or liquid crystal compounds is provided in Pure Appl. Chem. 73(5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. 2004, 116, 6340-6368. The term "spacer" or simply "spacer", also referred to as "Sp", above and below, is known to those skilled in the art and is described in the literature, see for example Pure Appl. Chem. 73(5), 888 (2001) and C. Tschierske, G. Pelzl, S. Diele, Angew. Chem. (2004), 116, 6340-6368. Unless otherwise indicated, the term "spacer group" or "spacer" above and below means a flexible group linking the mesogen group and the polymerizable group to each other in the polymerizable mesogen compound. . For the purposes of the present invention, the term "liquid-crystalline medium" is intended to mean a medium comprising a mixture of liquid crystals and one or more polymerizable compounds, such as reactive mesogens. The term "liquid crystal mixture" (or "host mixture") is intended to mean consisting exclusively of non-polymerizable low molecular weight compounds, preferably two or more liquid crystal compounds and optionally other additives such as chiral dopants or stabilizer) composed of liquid crystal mixture.

Particularly preferred are liquid crystal mixtures and liquid crystal media having a nematic phase, especially a nematic phase at room temperature.

In a preferred embodiment of the invention, the liquid crystal medium contains one or more compounds selected from the group of compounds of formula IA and more preferably selected from the group of compounds of formula Ia to formula Ic: or where the variables are as defined in Formula I above and below.

Particularly preferred here are compounds of formula I or formula IA or formula Ia/b/c, wherein n is 0 or 1, preferably 0. The group A ¹ here preferably represents a 1,4-phenylene group, which is optionally fluorinated, particularly preferably .

The group A ⁰ here is preferably represented by .

Compounds of formula I and the related more specific formulas above and below are preferred, wherein independently: n is 0 or 1, X ¹ is CF ₃ or F, preferably CF ₃ , R ¹ is having 1 Alkyl groups with up to 7 C atoms, wherein one or more CH ₂ groups including the terminal C atoms in the group can each be independently passed through -C≡C-, -CH in such a way that the O atoms are not directly connected to each other. =CH-、 or -O- substitution, and wherein in addition, one or more H atoms may be substituted by F; preferably an alkyl group having 2 to 7 C atoms.

In a preferred embodiment of the present invention, the liquid crystal medium contains one or more compounds selected from the group of compounds of formula I-1 to formula I-42: Wherein R ¹ and X ¹ are as defined above and below for formula I, including preferred definitions.

Preferable compounds of formula T are selected from compounds of the following formulas The group is as defined above, and L ¹ is preferably H.

In the formula T and in the formulas more defined above and below, the group R ¹ is preferably a linear or branched alkyl group having from 1 to 12 C atoms, which additionally includes one of the terminal C atoms or Multiple CH ₂ groups can be independently connected to each other via -CH=CH-, -C≡C-, , -O-, -S-, -CO-, -CO-O-, -O-CO-, and wherein in addition, one or more H atoms can be replaced by F or Cl, preferably with 1 to 7 Alkyl group with C atoms or alkenyl group with 2 to 7 C atoms; cyclopentylmethyl or cyclopentyl group.

In the formula T and the more defined formulas above and below, the group R ² is preferably a linear or branched alkyl group having from 1 to 12 C atoms, which additionally includes one of the terminal C atoms or Multiple CH ₂ groups can be independently connected to each other via -CH=CH-, -C≡C-, , -O-, -S-, -CO-, -CO-O-, -O-CO- substitution; group -CF ₃ , -OCF ₃ or F, preferably methyl, ethyl, n-propyl , n-butyl, CF ₃ or F, preferably methyl, ethyl or propyl.

In a preferred embodiment of the present invention, the liquid crystal medium contains one or more compounds selected from the group of compounds of formula T-1 to formula T-4: Wherein R ² is CH ₃ , CH ₂ CH ₃ , CF ₃ or F, preferably CH ₃ or CF ₃ .

In a preferred embodiment of the present invention, the liquid crystal medium includes one or more preferably dielectrically positive compounds having a dielectric anisotropy greater than 3, which are selected from the group consisting of Formula II-1 and Formula II Group of compounds of -2: wherein the parameters have their respective meanings as indicated above according to formula II, and L ²³ and L ²⁴ independently represent H or F, preferably L ²³ represents F, and having one of the meanings given with respect to And in the case of formula II-1 and formula II-2, X ² preferably represents F or OCF ₃ , particularly preferably F, and in the case of formula II-2, and , it is better to express independently of each other , And/or selected from the group of compounds of formula III-1 and formula III-2: wherein the parameters have the meanings given according to formula III, and as an alternative to or in addition to compounds of formula III-1 and/or formula III-2, the medium according to the invention may comprise one or more compounds of formula III-1 and/or III-2. III-3 compounds wherein the parameters have their respective meanings as indicated above, and parameters L ³¹ and L ³² represent H or F independently of each other and independently of the other parameters.

The liquid crystal medium preferably contains a compound selected from the group of compounds of formula II-1 and formula II-2, wherein L ²¹ and L ²² and/or L ²⁴ and L ²⁵ both represent F.

In a preferred embodiment, the liquid crystal medium includes a compound selected from the group of compounds of formula II-2, wherein L ²¹ , L ²² , L ²⁴ and L ²⁵ all represent F.

The liquid crystal medium preferably contains one or more compounds of formula II-1. The compound of formula II-1 is preferably selected from the group of compounds of formula II-1a to formula II-1e, preferably formula II-1a and/or formula II-1b and/or formula II-1d, preferably formula II -1a and/or formula II-1d or formula II-1b and/or formula II-1d, preferably one or more compounds of formula II-1d: wherein the parameters have the respective meanings indicated above, and the parameters L ²⁵ and L ²⁶ represent H or F independently of each other and independently of other parameters, and preferably in formula II-1a and formula II-1b, L ²¹ and L ²² both represent F, in formula II-1c and formula II-1d, L ²¹ and L ²² both represent F and/or L ²³ and L ²⁴ both represent F, and in formula II-1e, L ²¹ , L ²² and L ²³ represent F and each of the rings, preferably the phenylene ring, may optionally be substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group.

The liquid crystal medium preferably contains one or more compounds of formula II-2, which are preferably selected from the group of compounds of formula II-2a to formula II-2k, preferably formula II-2a and/or formula II-2h and/or One or more compounds of formula II-2j and/or formula II-2k: The parameters have the respective meanings indicated above, and L ²⁵ to L ²⁸ independently represent H or F, preferably L ²⁷ and L ²⁸ both represent H, especially preferably L ²⁶ represents H, and each of them represents The rings and preferably the phenylene rings may each be optionally substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group.

The liquid crystal medium preferably contains a compound selected from the group of compounds of formula II-2a to formula II-2k, wherein both L ²¹ and L ²² represent F and/or both L ²³ and L ²⁴ represent F.

In a preferred embodiment, the liquid crystal medium includes a compound selected from the group of compounds of Formula II-2a to Formula II-2k, wherein L ²¹ , L ²² , L ²³ and L ²⁴ all represent F.

Particularly preferred compounds of formula II-2 are compounds of the following formula, particularly preferred compounds of formula II-2a-1 and/or formula II-2h-1 and/or formula II-2k-2: wherein R ² and X ² have the meanings indicated above, and X ² preferably represents F.

The liquid crystal medium preferably contains one or more compounds of formula III-1. The compound of formula III-1 is preferably selected from the group of compounds of formula III-1a to formula III-1j, preferably selected from the group of compounds of formula III-1d, formula III-1e, formula III-1g, formula III-1h, formula III- 1j, Formula III-1k and Formula III-1m: wherein the ^parameters have the meanings given above, and preferably wherein Alkenyloxy group preferably represents F, Cl, -OCF ₃ , -OCHF ₂ , -O-CH ₂ CF ₃ , -O-CH=CF ₂ or -CF ₃ , and more preferably represents F, -OCF ₃ or - CF ₃ , L ³³ and L ³⁴ independently represent H or F, L ³⁵ and L ³⁶ independently represent H or F, preferably H.

The liquid crystal medium preferably contains one or more compounds of formula III-1c, which are preferably selected from the group of compounds of formula III-1c-1 to formula III-1c-5, preferably formula III-1c-1 and/or formula III-1c-2 compounds, preferably compounds of formula III-1c-1: wherein R ³ has the meaning indicated above and each of the rings, preferably the phenylene ring, may optionally be each substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group. .

The liquid crystal medium preferably contains one or more compounds of formula III-1d, which are preferably selected from the group of compounds of formula III-1d-1 to formula III-1d-2, preferably compounds of formula III-1d-1: Wherein R ³ is as defined above, and X ³ is CF ₃ , F or OCF ₃ , preferably CF ₃ .

The liquid crystal medium preferably contains one or more compounds of formula III-1g, which are preferably selected from the group of compounds of formula III-1g-1 to formula III-1g-6, preferably formula III-1g-1 and/or formula III-1g-2 and/or compounds of formula III-1g-3 and/or formula III-1g-6, more preferably compounds of formula III-1g-3 and/or formula III-1g-6, more preferably compounds of formula III -1g-6 compound: wherein R ³ has the meaning indicated above and each of the rings, preferably the phenylene ring, may optionally be each substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group. .

The liquid crystal medium preferably contains one or more compounds of formula III-1h, which are preferably selected from the group of compounds of formula III-1h-1 to formula III-1h-5, and are preferably compounds of formula III-1h-3: wherein R ³ has the meaning indicated above and each of the rings, preferably the phenylene ring, may optionally be each substituted by one or two alkyl groups, preferably by methyl and/or ethyl groups, preferably by one methyl group. .

The liquid crystal medium preferably contains one or more compounds selected from formula III-1j, formula III-1k and formula III-1m, which is preferably selected from formula III-1j-1, formula III-1k-1 and formula III-1m. The group of compounds of -1 is preferably a compound of formula III-1j-1: wherein the parameters have the meanings given above, and X ³ preferably represents F or -OCF ₃ .

The liquid crystal medium preferably contains one or more compounds of formula III-1m, which are preferably selected from the group of compounds of formula III-1m-1 and formula III-1m-2, preferably compounds of formula III-1m-1: wherein the parameters have the meanings given above and wherein each ring and preferably the phenylene ring may each be optionally passed through one or two alkyl groups, preferably through methyl and/or ethyl groups, preferably through one methyl group replace.

The liquid crystal medium according to the present invention preferably contains one or more dielectric neutral compounds having a dielectric anisotropy in the range of -1.5 to 3, which are preferably selected from the group consisting of formula VI, formula VII, formula VIII and formula IX. Group of compounds.

In this application, all elements include their respective isotopes. In particular, one or more H's in the compound may be replaced by D, and in some embodiments, this is also particularly preferred. The increased degree of deuteration of the corresponding compound enables, for example, the detection and identification of the compound.

In this application, alkyl particularly preferably means a linear alkyl group, especially CH ₃ -, C ₂ H ₅ -, n -C ₃ H ₇ -, n -C ₄ H ₉ - or n -C ₅ H ₁₁ -, and alkenyl particularly preferably represent CH ₂ =CH-, E -CH ₃ -CH=CH-, CH ₂ =CH-CH ₂ -CH ₂ -, E -CH ₃ -CH=CH-CH. ₂ -CH ₂ - or E -( n -C ₃ H ₇ )-CH=CH-.

In another preferred embodiment, the medium contains one or more compounds of formula IV, preferably compounds of formula IVa Wherein R ⁴¹ represents an unsubstituted alkyl group with 1 to 7 C atoms or an unsubstituted alkenyl group with 2 to 7 C atoms, preferably n-alkyl group, especially preferably with 2, 3, or 4 or 5 C atoms, and R ⁴² represents an unsubstituted alkyl group having 1 to 7 C atoms, an unsubstituted alkenyl group having 2 to 7 C atoms, or an unsubstituted alkenyl group having 1 to 6 C atoms. Substituted alkoxy groups preferably have 2 to 5 C atoms, preferably unsubstituted alkenyl groups with 2, 3 or 4 C atoms, more preferably vinyl or 1-propenyl, and especially for vinyl.

In a particularly preferred embodiment, the medium contains one or more compounds of formula IV, which are selected from the group of compounds of formula IV-1 to formula IV-5, preferably compounds of formula IV-1, Where alkyl and alkyl', independently represent an alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms, alkenyl and alkenyl', independently represent an alkyl group having 2 to 5 C atoms, preferably Alkenyl with 2 to 4 C atoms, preferably with 2 C atoms, alkenyl' preferably means with 2 to 5 C atoms, preferably with 2 to 4 C atoms, especially preferably with 2 to 3 alkenyl group having 1 to 5 C atoms, and alkoxy represents an alkoxy group having 1 to 5 C atoms, preferably 2 to 4 C atoms.

In a particularly preferred embodiment, the medium according to the invention contains one or more compounds of formula IV-1 and/or one or more compounds of formula IV-2.

In another preferred embodiment, the medium contains one or more compounds of formula IV selected from the group of compounds of formula IV-2 and formula IV-3, Where alkyl and alkyl' independently represent an alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms, and alkoxy represents an alkyl group having 1 to 5 C atoms, preferably 2 to 4 C atoms. The alkoxy group.

In another preferred embodiment, the medium contains one or more compounds of formula V. In this further preferred embodiment, the medium contains one or more compounds of formula V, which are selected from the group of compounds of formula V-1 to formula V-5, preferably formula V-1, formula V-3, formula V One or more of -4 and formula V-5, The parameters have the meanings given above according to formula V, and preferably R ⁵¹ represents an alkyl group having 1 to 7 C atoms or an alkenyl group having 2 to 7 C atoms, and R ⁵² represents a group having 1 to 7 C atoms. An alkyl group with 7 C atoms, an alkenyl group with 2 to 7 C atoms or an alkoxy group with 1 to 6 C atoms is preferably an alkyl group or an alkenyl group.

In another preferred embodiment, the medium contains one or more compounds of formula V-1, wherein at least one of the R ⁵¹ and R ⁵² groups is an alkenyl group having 2 to 6 carbon atoms, preferably selected from The group of the following formula: Where alkenyl preferably represents an alkenyl group having 2 to 5 C atoms, preferably 2 to 4 C atoms, particularly preferably vinyl or 3-but-1-yl, and R ⁵² is as defined above, And preferably it is methyl or ethyl.

In another preferred embodiment, the medium contains one or more compounds of formula V-3, wherein at least one of the R ⁵¹ and R ⁵² groups is an alkenyl group having 2 to 6 carbon atoms, preferably selected from The group of the following formula: Wherein "Alkyl" has the definition given above, and is preferably methyl or ethyl. Particularly preferred are compounds of formula V-3d.

In another preferred embodiment, the medium contains one or more compounds of formula V-4, which are selected from the group of compounds of formula V-4a to formula V-4c, Where alkyl and alkyl* are each independently a straight-chain alkyl group having 1 to 6 carbon atoms, especially methyl, ethyl, n-propyl and pentyl.

The liquid crystal medium preferably contains two, three or more compounds selected from the group of compounds of formula V-4a, formula V-4b and formula V-4c.

In another preferred embodiment, the medium contains one or more compounds of formula V-5, which are selected from the group of compounds of formula V-5a to formula V-5c, preferably V-5a: Wherein alkyl and alkyl* are each independently a straight-chain alkyl group with 1 to 6 carbon atoms, especially methyl, ethyl or n-propyl, and alkenyl preferably represents 2 to 5 C atoms, preferably with The alkenyl group having 2 to 4 C atoms is particularly preferably vinyl group.

The medium according to the invention preferably contains the following compounds in the total concentrations indicated: 1-30% by weight of one or more compounds selected from the group of compounds of formula I, and 2-60% by weight Preferably one or more compounds of formula II selected from the group of compounds of formula II-1 and formula II-2, and/or 1-60% by weight one or more compounds of formula III, and/or 20-80% by weight one or more compounds of formula IV, and/or 0-20% by weight one or more compounds of formula T, and/or 0-50% by weight one or more compounds of formula V, and/or 0-20% by weight one or more compounds of formula VI, and/or 0-20% by weight one or more compounds of formula VII, and/or 0-20% by weight Preferably one or more compounds of formula VIII selected from the group of compounds of formula VIII-1 and formula VIII-2, and/or 0-20% by weight one or more compounds of formula IX, and/or 0-30% by weight One or more compounds selected from the group of compounds of formula X wherein the total content of all compounds of formula I, formula T, formula II to formula IX and formula X present in the medium is preferably 95% or higher, more preferably 97% or higher and most preferably 100%, But never more than 100%.

The latter applies to all media under this application.

In another preferred embodiment, in addition to the compound of formula I or its preferred subformulas, the medium according to the invention preferably contains one or more dielectrically neutral compounds selected from the group of compounds of formula IV and formula V, the total of which The concentration is preferably 5 wt% or higher to 90 wt% or lower, preferably 10 wt% or higher to 80 wt% or lower, especially preferably 20 wt% or higher to 70 wt% or lower. within a lower range.

In a particularly preferred embodiment, the medium according to the invention independently contains One or more compounds of formula I, the total concentration of which is in the range of 3% or more and 30% or less, preferably in the range of 5% or more and 25% or less, and/or One or more compounds of formula T, the total concentration of which is in the range of 1% or higher and 40% or lower, preferably in the range of 5% or higher and 25% or lower, and/or One or more compounds of formula II, the total concentration of which is in the range of 5% or more and 50% or less, preferably in the range of 10% or more and 40% or less, and/or One or more compounds of formula III, the total concentration of which is in the range of 5% or more and 50% or less, preferably in the range of 10% or more and 40% or less, and/or One or more compounds of formula IV-1 and formula IV-2, the total concentration of which is in the range of 5% or higher and 55% or lower, preferably in the range of 25% or higher and 50% or lower within, and/or The total concentration of one or more compounds of formula V is in the range of 3% or higher and 30% or lower, preferably in the range of 20% or higher and 30% or lower.

All percentages (%) of mixture components within the present invention are to be understood as being in weight %.

Preferably, the concentration of the compound of formula I in the medium according to the present invention is 1% or higher to 20% or lower, more preferably 1.5% or higher to 20% or lower, most preferably 2% or lower. Higher to within the range of 12% or lower.

In a preferred embodiment of the present invention, the concentration of the compound of formula II in the medium is 3% or higher to 60% or lower, more preferably 5% or higher to 55% or lower, more preferably 10% or higher to 50% or lower and preferably in the range of 15% or higher to 45% or lower.

In a preferred embodiment of the present invention, the total concentration of the compounds of formula I, formula T and formula V in the medium is 30% or higher to 55% or lower, more preferably 35% or higher to 45% or within a lower range.

In a preferred embodiment of the present invention, the total concentration of the compounds of formula IV-1, formula IV-2 and formula V-1 in the medium is 45% or higher to 75% or lower, more preferably 55% or higher to within the range of 70% or lower.

In a preferred embodiment of the present invention, the total concentration of the compounds of formula III-1d and formula V-5 in the medium is 4% or higher to 25% or lower, more preferably 8% or higher to 20%. % or lower.

In a preferred embodiment of the present invention, the total concentration of compounds of formula V-1a and formula V-5 (preferred formula V-5a) in the medium is 12% or higher to 30% or lower, preferably In the range of 18% or higher to 28% or lower.

The invention also relates to electro-optical displays or electro-optical components containing a liquid crystal medium according to the invention. Preferred are electro-optical displays based on FFS, IPS, VA or ECB effects, preferably based on IPS or FFS effects, and especially electro-optical displays addressed by means of active matrix addressing devices.

The invention therefore also relates to the use of a liquid-crystalline medium according to the invention in electro-optical displays or electro-optical components, and to a method for preparing a liquid-crystalline medium according to the invention, characterized in that one or more compounds of the formula I are combined with a Or a variety of additional liquid crystal original base compounds and one or more additives are selected as appropriate.

In addition to the compounds of formula I, formula T, formula II to formula X and formula L, other ingredients may also be present, for example in an amount of up to 45%, but preferably up to 35%, especially up to 10% of the total mixture.

The medium according to the present invention may also optionally contain a dielectric negative compound, the total concentration of which is preferably 20% or less, more preferably 10% or less, based on the entire medium.

In a preferred embodiment, based on the entire mixture, the liquid crystal medium according to the present invention contains in total, 1% or more to 30% or less, preferably 1.5% or more to 20% or less, especially preferably 2% or more to 10% or less of the compound of formula I, and/or 1% or more to 35% or less, preferably 2% or more to 30% or less, especially preferably 5% or more to 25% or less of the compound of formula T, and/or 3% or more to 50% or less, preferably 4% or more to 45% or less, especially preferably 5% or more to 40% or less of compounds of formula II and/or formula III, and/or 40% or more to 70% or less, preferably 50% or more to 65% or less, especially preferably 55% or more to 65% or less, compounds of formula IV and/or formula V, and/or 0% or more to 30% or less, 0% or more to 20% or less, preferably 0% or more to 15% or less of Formula VI and/or Formula VII and/or Formula VIII and/or compounds of formula IX.

Liquid-crystalline media according to the invention may contain one or more chiral compounds.

Particularly preferred embodiments of the present invention satisfy one or more of the following conditions: The abbreviations (abbreviations) are explained in Tables A to C and illustrated by the examples in Table D.

Preferably, the medium according to the present invention satisfies one or more of the following conditions. i. The liquid crystal medium has a birefringence of 0.060 or greater, particularly preferably 0.070 or greater. ii. The liquid crystal medium has a birefringence of 0.200 or less, especially preferably 0.180 or less. iii. The liquid crystal medium has a birefringence in the range of 0.090 or greater to 0.180 or less. iv. The liquid crystal medium contains one or more particularly preferred compounds of formula I, which are preferably selected from (sub)formulas I-A or Ia to Ic. v. The liquid crystal medium contains one or more particularly preferred compounds of formula T, which are preferably selected from (sub)formula T-1 to T-53, and the best is (sub)formula T-6. vi. The total concentration of the compound of formula II in the entire mixture is 0.5% or higher, preferably 1% or higher, and preferably 14% or lower, especially preferably 9% or lower, and extremely Preferably in the range of 1% or higher to 6% or lower. vii. The liquid crystal medium contains one or more compounds of formula IV selected from the group of compounds of the formula: CC-n-V and/or CC-n-Vm and/or CC-n-nVm and/or CC-V-V and/or CC- V-Vn and/or CC-nV-Vn, especially preferably CC-3-V, the concentration is preferably at most 60% or lower, especially preferably at most 50% or lower, and optionally except for CC- In addition to 3-V, compound CC-3-V1, the concentration is preferably at most 15% or less, and/or CC-3-2V1, the concentration is preferably at most 15% or less, and/or CC-4- V, the concentration is preferably at most 40% or lower, particularly preferably at most 30% or lower, and/or CC-5-V, the concentration is preferably at most 20% or lower. viii. The medium contains a compound of formula CC-n-V, preferably CC-3-V, preferably at a concentration of 1% or higher and 60% or lower, and preferably at a concentration of 20% or higher and 55% or lower. lower. ix. The liquid crystal medium contains one or more compounds of formula IV, preferably formula IV-1 and/or formula IV-2, the total concentration of which is preferably 20% or higher, especially 30% or higher and preferably 40% or higher, and preferably in the range of 46% to 55% of the compound of formula IV-1. x. The total concentration of the compound of formula V in the entire mixture is 15% or higher, preferably 20% or higher, and preferably in the range of 15% or higher to 40% or lower, especially preferably In the range of 20% or higher to 30% or lower. xi. The total concentration of the compound of formula V-3 in the entire mixture is preferably 5% or higher and 25% or lower, preferably 5% or higher and 15% or lower. xii. The total concentration of compounds of formula V-4 and preferably formulas V-4a to V-4c in the entire mixture is preferably 3% or higher and 30% or lower, preferably 10% or higher and 25% % or lower. xiii. The total concentration of compounds selected from formula V-5, preferred formulas V-5-a and III-1d, and preferred formula III-1d-1 in the entire mixture is preferably 2% or higher to 20% or Lower, preferably 4% or higher to 15% or lower.

The invention further relates to an electro-optical display with active matrix addressing based on the IPS, FFS or UB-FFS effect, characterized in that it contains a liquid crystal medium according to the invention as a dielectric.

The nematic phase range of the liquid crystal mixture preferably has a width of at least 70 degrees.

The rotational viscosity γ ₁ is preferably 350 mPa∙s or less, preferably 250 mPa∙s or less, and especially 150 mPa∙s or less.

The mixture according to the invention is suitable for all IPS and FFS-TFT applications using dielectrically positive liquid crystal media, such as XB-FFS.

The liquid-crystalline medium according to the invention preferably consists almost entirely of 4 to 15 compounds, in particular 5 to 12 compounds and particularly preferably 10 compounds or less. The compounds are preferably selected from the group of compounds of formulas I, T, II, III, IV, V, VI, VII, VIII and IX.

Liquid crystal media according to the invention may optionally contain more than 18 compounds. In this case, it preferably contains 18 to 25 compounds.

In a preferred embodiment, the liquid-crystalline medium according to the invention mainly contains, preferably essentially consists of and most preferably almost entirely consists of cyano-free compounds.

In a preferred embodiment, the liquid crystal medium according to the present invention includes a group of compounds selected from formulas I, T, II, III, IV and V, preferably selected from formulas Ia, T-1/-2, II- 1. Compounds of the group of compounds II-2, III-1, III-2, IV and V; preferably mainly, especially preferably essentially and very preferably almost entirely composed of compounds of the formula.

The liquid crystal medium according to the invention preferably has in each case a temperature of at least -10°C or lower to 70°C or higher, particularly preferably -20°C or lower to 80°C or higher, very especially preferably -30°C. or lower to 85°C or higher and optimally -40°C or lower to 90°C or higher nematic phase.

The expression "having a nematic phase" means here that, on the one hand, no smectic phase and crystallization are observed at low temperatures corresponding to the corresponding temperatures, and, on the other hand, that no clarification occurs outside the nematic phase on heating. Studies at low temperatures were performed in flow viscometers at corresponding temperatures and checked by storage in test cells with cell thickness corresponding to the electro-optical application for at least 100 hours. A medium is considered stable at a temperature of -20°C if the storage stability in the corresponding test unit is 1,000 hours or more. At temperatures of -30°C and -40°C, the corresponding times are 500 hours and 250 hours respectively. At elevated temperatures, the clearing point is measured in a capillary tube by conventional methods.

In a preferred embodiment, the liquid crystal medium according to the invention is characterized by optical anisotropy values in the medium to low range. The birefringence value is preferably in the range of 0.075 or more to 0.130 or less, particularly preferably in the range of 0.085 or more to 0.120 or less and very particularly preferably in the range of 0.090 or more to 0.115 or more within a small range.

On the one hand, preferably the liquid crystal medium according to the invention has a dielectric anisotropy value of 1.5 or greater, preferably 2.5 or greater. On the other hand, it preferably has a dielectric anisotropy of 26 or less, preferably 15 or less, and most preferably 10 or less.

In this embodiment, the liquid crystal medium according to the present invention has a positive dielectric anisotropy Δε, which is preferably 2.0 or more to 20 or less (more preferably 15 or less), more preferably 2.0 or more. As large as 10 or less, especially preferably in the range of 2.0 or more to 9.0 less and very particularly preferably in the range of 2.5 or more to 8.0 or less.

The liquid crystal medium according to the present invention preferably has a relatively low threshold voltage (V ₀ ) value, which is 1.0 V or higher to 5.0 V or lower (preferably 2.5 V or lower), preferably 1.2 V or higher to 2.2 V or lower, particularly preferably in the range of 1.3 V or higher to 2.0 V or lower.

In addition, the liquid crystal medium according to the present invention has a high VHR value in the liquid crystal cell.

Generally speaking, liquid crystal media with low addressing voltages or threshold voltages will have a lower VHR here than those with higher addressing voltages or threshold voltages, and vice versa.

These preferred values of the individual physical properties are in each case preferably maintained also by combining the media with one another according to the invention.

In this application, unless otherwise expressly indicated, the term "compounds", also written as "compound(s)" means one and a plurality of compounds.

For the present invention, unless otherwise indicated in the individual case, the following definitions apply with respect to the description of the ingredients of the composition: - "Contains": the concentration of the ingredient in question in the composition is preferably 5% or higher, more preferably 10% or higher, most preferably 20% or higher, - "Consisting essentially of": the concentration of the ingredient in question in the composition is preferably 50% or higher, particularly preferably 55% or higher and most preferably 60% or higher, - "Consisting essentially of": the concentration of the ingredient in question in the composition is preferably 80% or more, particularly preferably 90% or more and very particularly preferably 95% or more, and - “Consisting almost entirely of”: The concentration of the ingredient in question in the composition is preferably 98% or higher, more preferably 99% or more and most preferably 100.0%.

This applies both to the medium that is a composition having its constituents, which can be a group of compounds as well as to individual compounds, and also to a group of compounds, that is to say compounds, having its individual constituents. The term includes, with reference only to the concentration of the individual compound relative to the medium as a whole, the concentration of the compound or compounds in question is preferably 1% or more, more preferably 2% or more, very especially more The best is 4% or higher.

For the present invention, "≤" means less than or equal to, preferably less than, and "≥" means greater than or equal to, preferably greater than.

For the present invention Represents trans -1,4-cyclohexylene, means a mixture of cis -1,4-cyclohexylene and trans -1,4-cyclohexylene, and Represents 1,4-phenylene group.

Throughout this application, 1,3-cyclopentenyl is selected from the group consisting of: , Preferably , Best for part of the group.

For the present invention, the expression "dielectrically positive compound" means a compound with Δε>1.5, the expression "dielectrically neutral compound" means a compound with -1.5≤Δε≤1.5, and the expression "dielectrically negative compound" means a compound with Compounds with Δε<-1.5. In this context, the dielectric anisotropy of a compound is determined by dissolving 10% by weight of the compound in a liquid crystal host and determining in each case the capacitance of the resulting mixture in at least one test cell having 20 µm cell thickness with vertical and uniform surface alignment at 1 kHz. The measured voltage is typically 0.5 V to 1.0 V, but is always below the capacitance critical value of the individual liquid crystal mixtures studied.

The host mixture for dielectrically positive and dielectrically neutral compounds is ZLI-4792, and the host mixture for dielectrically negative compounds is ZLI-2857, both from Merck KGaA in Germany. The values for the individual compounds studied are obtained from the change in the dielectric constant of the bulk mixture after addition of the compound studied and extrapolated to 100% of the compound used. The compounds under study were dissolved in the bulk mixture in an amount of 10% by weight. If the solubility of the substance is too low for this purpose, reduce the concentration by half during the procedure until the study can be performed at the required temperature.

If desired, the liquid crystal medium according to the invention may further comprise conventional amounts of additives, such as stabilizers and/or polychromatic (eg bichromatic) dyes and/or chiral dopants. The total amount of these additives used is preferably 0% by weight or higher and 10% by weight or lower based on the amount of the entire mixture, particularly preferably 0.1% by weight or higher and 6% by weight or lower. . The concentrations of individual compounds used are preferably 0.1% or higher and 3% or lower. The concentration of these and similar additives is generally not considered when specifying the concentration and concentration range of liquid crystal compounds in a liquid crystal medium.

In a preferred embodiment, the liquid crystal medium according to the present invention includes a polymer precursor, which includes one or more reactive compounds, preferably reactive mesogens, and if necessary, the liquid crystal medium further includes Usual amounts of additives such as polymerization initiators and/or polymerization moderators. The additives used are used in a total amount of 0% by weight or more and 10% by weight or less, based on the total mixture, particularly preferably 0.1% by weight or more and 2% by weight or less. The concentrations of these and similar additives are not taken into account when specifying concentrations and concentration ranges of liquid crystal compounds in liquid crystal media.

The composition is composed of a plurality of compounds mixed in a conventional manner, preferably 3 or more to 30 or less, particularly preferably 6 or more to 20 or less, and very particularly preferably 10. or more to 16 or less compounds. Generally, the required amount of compound, which is used in smaller amounts, is dissolved in the compound constituting the main component of the mixture. This should be done at high temperature. Completion of the dissolution operation is particularly easy to observe if the selected temperature is above the clearing point of the main component. However, it is also possible to prepare the liquid crystal mixture in other conventional ways, such as using a premix or a so-called "multi-bottle system".

Mixtures according to the invention exhibit a very broad nematic range with a clearing point of 65°C or higher, a very favorable capacitance critical value, a relatively high retention value and are excellent at -30°C and -40°C at the same time The low temperature stability. Furthermore, the mixtures according to the invention are distinguished by a low rotational viscosity γ ₁ .

It is self-evident to those skilled in the art that the media according to the invention for use in VA, IPS, FFS or PALC displays can also contain compounds in which, for example, H, N, O, Cl, F have been correspondingly isotopically substituted.

The structure of the FFS liquid crystal display according to the invention corresponds to common geometries as described, for example, in US 2002/0041354 A1.

The liquid crystal phases according to the present invention can be modified by means of suitable additives in such a way that they can be used, for example, in any type of IPS and FFS LCD displays disclosed so far.

Table E below indicates possible dopants that can be added to the mixture according to the invention. If the mixture contains one or more dopants, their amount is 0.01% to 4% by weight, preferably 0.1% to 1.0% by weight.

Stabilizers that can be added to, for example, the mixtures according to the invention, preferably in an amount of 0.01% to 6% by weight, in particular 0.1% to 3% by weight, are shown in Table F below.

For the purposes of this invention, all concentrations are indicated in weight percent and, unless expressly indicated otherwise, refer to the corresponding total mixture or total mixture component. In this context, the term "mixture" describes a liquid crystalline medium.

Unless otherwise expressly indicated, all temperature values indicated in this application, such as melting point T(C,N), phase transition T(S,N) between smectic (S) and nematic (N) phases, and clarification Points T(N,I), are indicated in degrees Celsius (°C), and all temperature differences are accordingly indicated in degrees of difference (° or degrees).

For the purposes of this invention, unless otherwise explicitly indicated, the term "threshold voltage" refers to the capacitance threshold (V ₀ ), also known as the Freedericks threshold.

Unless otherwise expressly indicated in each case, all physical properties are and have been determined in accordance with "Merck Liquid Crystals, Physical Properties of Liquid Crystals", status November 1997, Merck KGaA, Germany, and apply at a temperature of 20°C , and Δn is measured at 436 nm, 589 nm and 633 nm and Δε is measured at 1 kHz.

Electro-optical properties, such as critical voltage (V ₀ ) (capacitance measurement), and switching behavior were measured in test cells manufactured by Merck Japan. The measurement unit has a soda-lime glass substrate and is constructed in an ECB or VA configuration using a polyimide alignment layer (SE-1211 and diluent **26 (mixing ratio 1:1), both from Nissan Chemicals, Japan). have been rubbed perpendicular to each other and achieved vertical alignment of the liquid crystal. The surface area of the transparent, virtually square ITO electrode is 1 cm ² .

Unless otherwise indicated, chiral dopants are not added to the liquid crystal mixtures used, but the latter are also particularly suitable for applications requiring such doping.

Rotational viscosity was measured in a modified Ubbelohde viscometer using the rotating permanent magnet method and flow viscosity. For the liquid crystal mixtures ZLI-2293, ZLI-4792 and MLC-6608 (all products are from Merck KGaA, Darmstadt, Germany), the rotational viscosity values measured at 20°C are 161 mPa·s, 133 mPa·s and 186 mPa respectively. ·s, and the flow viscosity values (ν) are 21 mm ² ·s ^-1 , 14 mm ² ·s ^-1 and 27 mm ² ·s ^-1 respectively.

Unless otherwise expressly stated, for practical purposes the dispersion of a material may conveniently be characterized in the following manner as used throughout this application. Birefringence values were measured at a temperature of 20°C at several fixed wavelengths using a modified Abbé refractometer with a vertically oriented surface on the side of the material in contact with the material. At specific wavelength values 436 nm (spectral line of individually selected low-pressure mercury lamps), 589 nm (sodium "D" line) and 633 nm (HE-Ne laser (used in combination with attenuator/diffuser to prevent damage The birefringence value is measured at the wavelength of the observer's eye). In the table below, Δn is given at 589 nm and Δ(Δn) is given as Δ(Δn) = Δn(436 nm) - Δn(633 nm).

Unless otherwise explicitly indicated, the following symbols are used: V ₀ Critical voltage at 20°C, Capacitance [V], n _e Unusual refractive index at 20°C and 589 nm, n _o Measured at 20°C and 589 nm Ordinary refractive index measured, Δn Optical anisotropy measured at 20℃ and 589 nm, λ Wavelength λ [nm], Δn(λ) Optical anisotropy measured at 20℃ and wavelength λ, Δ( Δn) The change of optical anisotropy defined as follows: Δn(20℃, 436 nm) - Δn(20℃, 633 nm), Δ(Δn*) The "relative change of optical anisotropy" defined as follows: Δ (Δn)/Δn(20℃, 589 nm), ε _⊥ at 20℃ and 1 kHz, the dielectric susceptibility perpendicular to the director, ε _|| at 20℃ and 1 kHz, parallel to the director Electromagnetic susceptibility, Δε Dielectric anisotropy at 20°C and 1 kHz, T(N,I) or clp. Clarification point [°C], ν Flow viscosity measured at 20°C [mm ² ·s ^{- 1} ], γ ₁ Rotational viscosity measured at 20°C [mPa·s], K ₁₁ elastic constant, "tilt" deformation at 20°C [pN], K ₂₂ elastic constant, "torsion" at 20°C "Deformation [pN] (K ₂₂ ≈ ½ K ₁₁ ), K ₃₃ elastic constant, "bending" deformation at 20°C [pN], K _av. Average elastic constant at 20°C [pN] is defined here as K _av. ≡ ( ³ / ₂ K ₁₁ + K ₃₃ ) / 3 ≈ (K ₁₁ + K ₂₂ + K ₃₃ ) / 3, LTS low temperature stability of the phase measured in the test unit, VHR voltage retention rate, ΔVHR voltage Reduction in retention rate, and relative stability of S _rel VHR.

The following examples illustrate the invention without limiting it. However, it demonstrates to those skilled in the art preferred mixture concepts and preferred compounds to use and their individual concentrations as well as their combinations with each other. In addition, examples illustrate available properties and combinations of properties.

For the present invention and in the following examples, the structures of the liquid crystal compounds are indicated by means of abbreviations, the conversion of the chemical formulas being carried out according to Tables A to C below. All the groups C _n H _{2n + 1} , C _m H _{2m + 1} and C _l H _{2l + 1} or C _n H _2n , C _m H _2m and C _l H _2l are linear alkyl or alkylene groups, in In each case there are n, m and l C atoms respectively. Preferably, n, m and l are 1, 2, 3, 4, 5, 6 or 7 independently of each other. Table A shows the coding of the ring elements of the nucleus of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols for the left and right end groups of the molecule. The abbreviation consists of the code of the ring element with the optional linking group, followed by the code of the first hyphen and the left-hand end group, and the second hyphen and the code of the right-hand end group. Table D shows the illustrative structures of the compounds and their respective abbreviations. Table A : Ring Elements Table B : Bridge Unit E -CH ₂ -CH ₂ - V -CH=CH- T -C≡C- W -CF ₂ -CF ₂ - B -CF=CF- Z -CO-O- ZI -O-CO- X -CF=CH- XI -CH=CF- O -CH ₂ -O- O.I. -O-CH ₂ - Q -CF ₂ -O- QI -O-CF ₂ - Table C : Terminal group individually or in combination on the left individually or in combination on the right -n- C _n H _2n+1 - -n -C _n H _2n+1 -nO- C _n H _2n+1 -O- -On -O- C _n H _2n+1 -V- CH ₂ =CH- -V -CH=CH ₂ -nV- C _n H _2n+1 -CH=CH- -nV -C _n H _2n -CH=CH ₂ -Vn- CH ₂ =CH- C _n H _2n - -Vn -CH=CH-C _n H _2n+1 -nVm- C _n H _2n+1 -CH=CH-C _m H _2m - -nVm -C _n H _2n -CH=CH-C _m H _2m+1 -N- N≡C- -N -C≡N -S- S=C=N- -S -N=C=S -F- F- -F -F -CL- Cl- -CL -Cl -M- CFH ₂ - -M -CFH ₂ -D- CF ₂ H- -D _-CF2H -T- CF ₃ - -T -CF ₃ -MO- CFH ₂ O - -OM -OCFH ₂ -DO- CF ₂ HO - -OD -OCF ₂ H -TO- CF ₃ O - -OT -OCF ₃ -A- HC≡C- -A -C≡CH -nA- C _n H _2n+1 -C≡C- -An -C≡CC _n H _2n+1 -NA- N≡CC≡C- -AN -C≡CC≡N -cp- cyclopentyl -cp cyclopentyl -cpr- cyclopropyl -cpr cyclopropyl only in combined form on the left On the right side only in combined form -…n…- -C _n H _2n - -…n… -C _n H _2n - -…M…- -CFH- -…M… -CFH- -…D…- -CF ₂ - -…D… -CF ₂ - -…V…- -CH=CH- -…V… -CH=CH- -…Z…- -CO-O- -…Z… -CO-O- -…ZI…- -O-CO- -…ZI… -O-CO- -…K…- -CO- -…K… -CO- -…W…- -CF=CF- -…W… -CF=CF- -…O…- -O- -…O…- -O- where n and m are each an integer, and the three dots " ... " are placeholders for other abbreviations from this table.

In addition to the compound of formula B, the mixture according to the invention preferably contains one or more of the compounds mentioned below.

The following abbreviations are used: (n, m, k and l are each independently an integer, preferably 1 to 9, preferably 1 to 7; k and l may also be 0, and preferably 0 to 4, More preferably, it is 0 or 2 and most preferably 2; n is preferably 1, 2, 3, 4 or 5, and in the combination "-nO-", it is preferably 1, 2, 3 or 4, preferably 2 or 4; m is preferably 1, 2, 3, 4 or 5. In the combination "-Om", it is preferably 1, 2, 3 or 4, and more preferably 2 or 4. The combination "-lVm" Preferably "2V1".) Table D Illustrative and preferred dielectric positive compounds Illustrative and preferred dielectrically neutral compounds Exemplary compounds with high _ε⊥ : Illustrative and preferred dielectric negative compounds

Table E shows preferred chiral dopants for use in mixtures according to the present invention. Table E

In a preferred embodiment of the invention, the medium according to the invention contains one or more compounds selected from the group of compounds in Table E.

Table F shows stabilizers which may furthermore preferably be used in the mixtures according to the invention. The parameter n here represents an integer in the range of 1 to 12. In particular, the phenol derivatives shown can be used as additional stabilizers by virtue of their role as antioxidants. Table F

In a preferred embodiment of the present invention, the medium according to the present invention contains one or more compounds selected from the group of compounds of Table F, especially one or more compounds selected from the group of compounds of the following two formulas

EXAMPLES The following examples illustrate the invention without limiting it in any way. However, the physical properties make it clear to those familiar with the technology what properties can be achieved and to what extent they can be modified. In particular, the combinations of properties that are therefore better achieved will be well-defined to those skilled in the art.

Synthesis Example Synthesis Example 1 ( PO - 3 - T ) 2-(4-propylphenyl)-5-(trifluoromethyl)furan Treated with bis(diphenylidene-acetone)palladium(0) (15 mg, 26 µmol) and gin-(o-tolyl)phosphine (40 mg, 131 µmol) at 50°C in an argon atmosphere1 -Bromo-4-propylbenzene ( 1 ) (CAS 588-93-2, 1.3 g, 7 mmol) and [5-(trifluoromethyl)-2-furyl]boronic acid in acetone (40 mL) (boronic acid) ( 2 ) (CAS 1308354-99-5, 1.3 g, 7 mmol) mixture. Aqueous sodium hydroxide solution (2 N , 6.5 mL, 13 mmol) was added slowly at reflux temperature, and the reaction mixture was heated at reflux temperature for 2 h. Next, it was allowed to cool to room temperature and quenched with distilled water/hydrochloric acid (2 N ) and diluted with MTB ether. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with distilled water and brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (solvent heptane) to obtain 2-(4-propylphenyl)-5-(trifluoromethyl)furan ( 3 ) as a colorless oil.

Compound ( 3 ) has the following phase characteristics: K 11℃ I Δε: 0.5 Δn: 0.038 γ ₁ : 5 mPa∙s

Synthesis Example 2 ( YO - 2O - T ) Synthesis of 2-(4-ethoxy-2,3-difluorophenyl)-5-(trifluoromethyl)furan Ginseng(diphenylidene-acetone)palladium(0) (35 mg, 38 µmol) and bis(1-adamantyl)-n-butylphosphine (25 mg, 70 µmol) 1-bromo-4-ethoxy-2,3-difluoro-benzene ( 4 ) (CAS 156573-09-0, 1.8 g, 8 mmol) was treated with THF (40 mL) and distilled water (8 mL ) in a mixture of potassium carbonate (1.6 g, 12 mmol). A solution of [5-(trifluoromethyl)-2-furyl]boronic acid ( 2 ) (CAS 1308354-99-5, 1.5 g, 8 mmol) in THF (10 mL) was slowly added at reflux temperature, and The reaction mixture was heated at reflux temperature for 5 hours. Next, it was allowed to cool to room temperature and quenched with distilled water/hydrochloric acid (2 N ) and diluted with MTB ether. The aqueous phase was separated and extracted with MTB ether. The combined organic phases were washed with distilled water and brine, dried (sodium sulfate) and concentrated in vacuo. The residue was purified by silica gel chromatography (solvent heptane) and crystallization (ethanol) to obtain white crystals of 2-(4-ethoxy-2,3-difluoro-phenyl)-5-(trifluoromethyl) Furans ( 5 ).

Compound ( 5 ) has the following phase characteristics: K 98°C I.

Other compound examples

Use the following abbreviations for end groups in the table below c -C ₃ H ₅ c -C ₃ H ₅ CH ₂ c -C ₄ H ₇ c -C ₅ H ₇ c -C ₅ H ₉

Other exemplary compounds: No. R ¹ L ¹ L ² L ³ X ¹ 1. CH ₃ H H H CF ₃ 2. C ₂ H ₅ H H H CF ₃ 3. n -C ₃ H ₇ H H H CF ₃ 4. n -C ₄ H ₉ H H H CF ₃ 5. n -C ₅ H ₁₁ H H H CF ₃ 6. n -C ₆ H ₁₃ H H H CF ₃ 7. n -C ₇ H ₁₅ H H H CF ₃ 8. n -C ₈ H ₁₇ H H H CF ₃ 9. c -C ₃ H ₅ H H H CF ₃ 10. c -C ₃ H ₅ -CH ₂ H H H CF ₃ 11. c -C ₄ H ₇ H H H CF ₃ 12. c -C ₅ H ₇ H H H CF ₃ 13. c -C ₅ H ₉ H H H CF ₃ 14. c -C ₅ H ₉ CH ₂ H H H CF ₃ 15. CH ₂ =CH H H H CF ₃ 16. CH ₃ CH=CH H H H CF ₃ 17. CH ₂ =CH(CH ₂ ) ₂ H H H CF ₃ 18. CH ₃ CH=CH(CH ₂ ) ₂ H H H CF ₃ 19. CH ₃ F H H CF ₃ 20. C ₂ H ₅ F H H CF ₃ twenty one. n -C ₃ H ₇ F H H CF ₃ twenty two. n -C ₄ H ₉ F H H CF ₃ twenty three. n -C ₅ H ₁₁ F H H CF ₃ twenty four. n -C ₆ H ₁₃ F H H CF ₃ 25. n -C ₇ H ₁₅ F H H CF ₃ 26. n -C ₈ H ₁₇ F H H CF ₃ 27. c -C ₃ H ₅ F H H CF ₃ 28. c -C ₃ H ₅ -CH ₂ F H H CF ₃ 29. c -C ₄ H ₇ F H H CF ₃ 30. c -C ₅ H ₇ F H H CF ₃ 31. c -C ₅ H ₉ F H H CF ₃ 32. c -C ₅ H ₉ CH ₂ F H H CF ₃ 33. CH ₂ =CH F H H CF ₃ 34. CH ₃ CH=CH F H H CF ₃ 35. CH ₂ =CH(CH ₂ ) ₂ F H H CF ₃ 36. CH ₃ CH=CH(CH ₂ ) ₂ F H H CF ₃ 37. CH ₃ F F H CF ₃ 38. C ₂ H ₅ F F H CF ₃ 39. n -C ₃ H ₇ F F H CF ₃ 40. n -C ₄ H ₉ F F H CF ₃ 41. n -C ₅ H ₁₁ F F H CF ₃ 42. n -C ₆ H ₁₃ F F H CF ₃ 43. n -C ₇ H ₁₅ F F H CF ₃ 44. n -C ₈ H ₁₇ F F H CF ₃ 45. c -C ₃ H ₅ F F H CF ₃ 46. c -C ₃ H ₅ -CH ₂ F F H CF ₃ 47. c -C ₄ H ₇ F F H CF ₃ 48. c -C ₅ H ₇ F F H CF ₃ 49. c -C ₅ H ₉ F F H CF ₃ 50. c -C ₅ H ₉ CH ₂ F F H CF ₃ 51. CH ₂ =CH F F H CF ₃ 52. CH ₃ CH=CH F F H CF ₃ 53. CH ₂ =CH(CH ₂ ) ₂ F F H CF ₃ 54. CH ₃ CH=CH(CH ₂ ) ₂ F F H CF ₃ 55. CH ₃ F H F CF ₃ 56. C ₂ H ₅ F H F CF ₃ 57. n -C ₃ H ₇ F H F CF ₃ 58. n -C ₄ H ₉ F H F CF ₃ 59. n -C ₅ H ₁₁ F H F CF ₃ 60. n -C ₆ H ₁₃ F H F CF ₃ 61. n -C ₇ H ₁₅ F H F CF ₃ 62. n -C ₈ H ₁₇ F H F CF ₃ 63. c -C ₃ H ₅ F H F CF ₃ 64. c -C ₃ H ₅ -CH ₂ F H F CF ₃ 65. c -C ₄ H ₇ F H F CF ₃ 66. c -C ₅ H ₇ F H F CF ₃ 67. c -C ₅ H ₉ F H F CF ₃ 68. c -C ₅ H ₉ CH ₂ F H F CF ₃ 69. CH ₂ =CH F H F CF ₃ 70. CH ₃ CH=CH F H F CF ₃ 71. CH ₂ =CH(CH ₂ ) ₂ F H F CF ₃ 72. CH ₃ CH=CH(CH ₂ ) ₂ F H F CF ₃

Mixture Examples Exemplary mixtures are disclosed below. All % values are weight %.

Mixture Example 1 The following mixture (M-1) was prepared and studied. compound % characteristic CC-3-V 32.0 T(N,I) [℃]: 79.5 CC-3-V1 7.0 Δn [589 nm, 20℃]: 0.1008 PO-3-T 8.0 n _e [589 nm, 20℃]: 1.5886 CCP-V-1 13.0 n _o [589 nm, 20℃]: 1.4878 CCP-V2-1 5.0 Δε [1 kHz, 20℃]: 4.8 CLP-V-1 7.0 ε _|| [1 kHz, 20℃]: 8.1 PGP-2-2V 5.0 ε _⊥ [1 kHz, 20℃]: 3.3 CDU-2-F 5.5 γ ₁ [mPa s, 20℃]: 54 CCVC-3-V 4.0 K ₁₁ [pN, 20℃]: 12.6 APUQU-2-F 3.0 K ₃₃ [pN, 20℃]: 13.9 APUQU-3-F 3.0 PGUQU-3-F 3.0 PGUQU-4-F 4.0 PPGU-3-F 0.5 Σ 100.0

This mixture has an advantageously low rotational viscosity γ ₁ of 54 mPa·s.

Mixture Examples 1.1 to 1.4 Alternatively , 0.05 % of a compound of one of the following formulas , Two O atoms bonded to N atoms indicate a group, and , respectively Add to mixture M-1. The obtained mixtures M-1.1, M-1.2, M-1.3 and M-1.4 are respectively characterized by improved stability against harsh conditions, especially exposure.

Comparative Mixture Example 1 The following mixture (C-1) was prepared and studied. It was prepared in a manner similar to Mixture Example 1, but without PO-3-T and with adjustments such that the parameters T(N,I), Δn and Δε were equilibrated to approximately the same target values in both mixtures. compound % characteristic CC-3-V 50.0 T(N,I) [℃]: 80.5 CC-3-V1 10.0 Δn [589 nm, 20℃]: 0.0985 CLP-V-1 1.0 n _e [589 nm, 20℃]: 1.5798 PGP-2-2V 5.0 n _o [589 nm, 20℃]: 1.4813 CDU-2-F 5.5 Δε [1 kHz, 20℃]: 4.9 CCVC-3-V 4.0 ε _|| [1 kHz, 20℃]: 8.3 APUQU-3-F 2.0 ε _⊥ [1 kHz, 20℃]: 3.4 PGUQU-3-F 8.0 γ ₁ [mPa s, 20℃]: 58 PGUQU-4-F 6.0 K ₁₁ [pN, 20℃]: 13.2 PPGU-3-F 0.5 K ₃₃ [pN, 20℃]: 15.2 CPY-3-O2 8.0 Σ 100.0 Table 1: Comparison of Mixtures C-1 and M-1 mixture Remarks Δε γ ₁ C-1 compare 5 58 mPa s M-1 invention 5 54 mPa s

The gamma 1 of the mixture M-1 according to the invention is improved by 9 _% over the mixture C-1.

Mixture Example 2 The following mixture (M-2) was prepared and studied. compound % characteristic CC-3-V 32.0 T(N,I) [℃]: 77.5 CC-3-V1 7.0 Δn [589 nm, 20℃]: 0.1017 PO-3-T 8.0 n _e [589 nm, 20℃]: 1.5897 CCP-V-1 13.0 n _o [589 nm, 20℃]: 1.4880 CCP-V2-1 5.0 Δε [1 kHz, 20℃]: 4.8 CLP-V-1 7.0 ε _|| [1 kHz, 20℃]: 8.1 PUS-3-2 5.0 ε _⊥ [1 kHz, 20℃]: 3.3 CDU-2-F 5.5 γ ₁ [mPa s, 20℃]: 53 CCVC-3-V 4.0 K ₁₁ [pN, 20℃]: 12.6 APUQU-2-F 3.0 K ₃₃ [pN, 20℃]: 13.7 APUQU-3-F 3.0 PGUQU-3-F 3.0 PGUQU-4-F 4.0 PPGU-3-F 0.5 Σ 100.0

Mixture Example 3 The following mixture (M-3) was prepared and studied. compound % characteristic CC-3-V 32.0 T(N,I) [℃]: 79.5 CC-3-V1 7.0 Δn [589 nm, 20℃]: 0.1008 PO-3-T 8.0 n _e [589 nm, 20℃]: 1.5886 CCP-V-1 13.0 n _o [589 nm, 20℃]: 1.4878 CCP-V2-1 5.0 Δε [1 kHz, 20℃]: 4.8 CLP-V-1 7.0 ε _|| [1 kHz, 20℃]: 8.1 PGS-3-2 5.0 ε _⊥ [1 kHz, 20℃]: 3.3 CDU-2-F 5.5 γ ₁ [mPa s, 20℃]: 54 CCVC-3-V 4.0 K ₁₁ [pN, 20℃]: 12.6 APUQU-2-F 3.0 K ₃₃ [pN, 20℃]: 13.9 APUQU-3-F 3.0 LTS volume [h, -20℃] 1000 PGUQU-3-F 3.0 PGUQU-4-F 4.0 PPGU-3-F 0.5 Σ 100.0

Claims (15)

A liquid crystal medium with a nematic phase, characterized in that it contains one or more compounds of formula I wherein R ¹ is an alkyl group having 1 to 15 C atoms, wherein one or more CH ₂ groups including terminal C atoms in this group may each be independently passed through - C≡C-、-CH=CH-、 , -O-, -S-, -(CO)-O-, -O-(CO)-, and wherein in addition, one or more H atoms may be replaced by F or Cl, A ¹ , L ¹ , L ² each independently of the other represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , OCH ₃ , CH ₂ F or CHF ₂ , Y CH ₃ , CH ₂ CH ₃ , A ⁰ , on each occurrence independently of one another, represents phenylene-1,4-diyl, wherein in addition one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH ₃ , CHF ₂ , CH ₂ F, OCH ₃ , OCHF ₂ or OCF ₃ substitution; cyclohexane-1,4-diyl, wherein in addition, one or two non-adjacent CH ₂ groups may be substituted independently of each other O and/or S are substituted and one or more H atoms may be substituted by F; cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2 ] Octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioctane-2,5-diyl group, Z ⁰ independently of each other, the same or different, represents a single bond, -CH ₂ O-, -(CO)O-, -CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -CF ₂ CF ₂ - , -CH ₂ CF ₂ -, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -CH=CH-, -CH=CF-, -CF=CF- or -C≡C-, where asymmetry The bridge may be inserted in any orientation, X ¹ F, Cl, -CF ₃ or -OCF ₃ , n represents 0, 1 or 2, preferably 0, and one or more additional compounds. The liquid crystal medium of claim 1, which contains one or more compounds of formula T The individual groups have the following meanings: R ¹ and R ² represent H, F, Cl, Br, -CN or a straight-chain or branched alkyl group with 1 to 12 C atoms, including one of the terminal C atoms. or multiple CH ₂ groups may each independently pass through -CH=CH-, -C≡C-, in such a way that the O or S atoms are not directly connected to each other , -O-, -S-, -CO-, -CO-O-, -O-CO-, and wherein in addition, one or more H atoms may be replaced by F or Cl, L ¹ H or CH ₃ , A ⁰ means wherein the (fluoro)phenylene ring may optionally be substituted by one or two methyl and/or ethyl groups, A ¹ , independently of each other, represent phenylene-1,4-diyl, wherein in addition, one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH ₃ , CHF ₂ , CH ₂ F, OCH ₃ , OCHF ₂ or OCF ₃ substitution; cyclohexane-1,4-diyl, wherein in addition, one or two non-adjacent CH ₂ groups can be independently substituted by O and/or S Replacement and one or more H atoms can be replaced by F; cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2]octane-1 ,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dihexane-2,5-diyl, m in each cases represent 0, 1 or 2 independently of each other. The liquid crystal medium of claim 1, wherein it contains one or more compounds selected from the group of compounds of formula II and formula III, wherein R ² is an alkyl group having 1 to 15 C atoms, wherein one or more CH ₂ groups including terminal C atoms in this group may each be independently passed through - C≡C-、-CH=CH-、 , -O-, -S-, -(CO)-O-, -O-(CO)-, and wherein in addition, one or more H atoms may be replaced by F or Cl; or H, and on each occurrence independently of each other as , wherein the (fluoro)phenylene rings are optionally substituted with one or two methyl and/or ethyl groups, L ²¹ and L ²² represent H or F, L ^2a H or CH ₃ , X ² represents halogen, halogenated alkyl or alkoxy group with 1 to 3 C atoms or halogenated alkenyl group with 2 or 3 C atoms or Alkenyloxy group, m represents 0, 1, 2 or 3, R ³ is an alkyl group with 1 to 15 C atoms, wherein this group includes one or more terminal C atoms and the CH ₂ group can make O or S The atoms are not directly connected to each other through -C≡C-, -CH=CH-, , -O-, -S-, -(CO)-O-, -O-(CO)-, and wherein in addition, one or more H atoms may be replaced by F or Cl, and on each occurrence independently of each other as , wherein the (fluoro)phenylene rings are optionally substituted with one or two methyl and/or ethyl groups, L ³¹ and L ³² independently represent H or F, L ^3a H or CH ₃ , X ³ represents halogen, halogenated alkyl or alkoxy group having 1 to 3 C atoms or 2 or 3 C atoms. Halogenated alkenyl or alkenyloxy group, Z ³ represents -CH ₂ CH ₂ -, -CF ₂ CF ₂ -, -COO-, trans -CH=CH-, trans -CF=CF-, -CH ₂ O- or a single bond, and n represents 0, 1, 2, or 3. The liquid crystal medium of claim 1, wherein it contains one or more dielectric neutral compounds selected from the group of formula IV and formula V: Wherein R ⁴¹ and R ⁴² are independently an alkyl group having 1 to 15 C atoms, wherein this group includes one or more CH ₂ groups at the terminal C atoms so that the O or S atoms are not directly connected to each other. The way each passes through -C≡C-, -CH=CH-, independently of each other , -O-, -S-, -(CO)-O-, -O-(CO)-, and wherein in addition, one or more H atoms may be replaced by F or Cl, independent of each other and if Appears twice, then these groups also represent independently of each other , wherein the (fluoro)phenylene rings are optionally substituted with one or two methyl and/or ethyl groups, Z ⁴¹ and Z ⁴² are independent of each other and if Z ⁴¹ appears twice, these groups also independently represent -CH ₂ CH ₂ -, -COO-, trans- CH=CH-, trans -CF= CF-, -CH ₂ O-, -CF ₂ O-, -C≡C- or single bond, p represents 0, 1 or 2, R ⁵¹ and R ⁵² , independently of each other, have the values given for R ⁴¹ and R ⁴² one of the meanings of "out" to , If present, each represents independently of the other , wherein the (fluoro)phenylene rings are optionally substituted with one or two methyl and/or ethyl groups, Z ⁵¹ to Z ⁵³ each independently represent -CH ₂ -CH ₂ -, -CH ₂ -O-, -CH=CH-, -C≡C-, -COO- or a single bond, and i and j each represent each other Independently represents 0 or 1. The liquid crystal medium of any one of claims 1 to 4, wherein it contains one or more compounds selected from the group consisting of the following formulas I-1 to I-42: wherein R ¹ and X ¹ have the meanings indicated in claim 1. The liquid crystal medium of any one of claims 1 to 4, wherein it additionally contains one or more compounds selected from formula III-1j, formula III-1k and formula III-1m: wherein R ³ represents an alkyl group, alkoxy group, fluorinated alkyl group or fluorinated alkoxy group with 1 to 7 C atoms; an alkenyl group, alkenyloxy group, alkoxyalkyl group with 2 to 7 C atoms Or fluorinated alkenyl, X ³ represents F, Cl, halogenated alkyl or alkoxy with 1 to 3 C atoms or halogenated alkenyl or alkenoxy with 2 or 3 C atoms, L ³³ and L ³⁴ , represent H or F independently of each other, and L ³⁵ and L ³⁶ , represent H or F independently of each other. The liquid crystal medium of any one of claims 1 to 4, which additionally contains one or more compounds selected from the group of compounds of formula IV-1 to formula IV-5, Where alkyl and alkyl', independently represent an alkyl group having 1 to 7 C atoms, alkenyl and alkenyl', independently represent an alkenyl group having 2 to 5 C atoms, and alkoxy represents an alkenyl group having 1 to 5 C atoms Alkoxy group of atoms. The liquid crystal medium of any one of claims 1 to 4, wherein the total concentration of the compound of Formula I in the entire medium is 1% or higher, but less than 30%. The liquid crystal medium of any one of claims 1 to 4, wherein it additionally contains one or more chiral compounds and/or stabilizers. An electro-optical display or electro-optical component, characterized in that it contains the liquid crystal medium according to any one of claims 1 to 9. The display of claim 10, wherein it is based on IPS mode or FFS mode. The display of claim 10 or 11, wherein it contains an active matrix addressing device. Use of a medium according to any one of claims 1 to 9 in electro-optical displays, electro-optical components or energy-saving applications. A method for preparing a liquid crystal medium according to any one of claims 1 to 9, characterized in that one or more compounds of the formula I are mixed with one or more additional mesogen compounds and optionally one or more additives. A compound of formula I Wherein R ¹ has an alkyl group with 1 to 15 C atoms, wherein one or more CH ₂ groups including the terminal C atom in this group can each independently undergo -C≡C-, -CH=CH-, replacement, A ¹ , L ¹ , L ² Each independently represents F, Cl, OCF ₃ , CF ₃ , CH ₃ , OCH ₃ , CH ₂ F, CHF ₂ , Y CH ₃ , CH ₂ CH ₃ , A ⁰ independently on each occurrence represents phenylene-1,4-diyl, wherein in addition one or two CH groups may be replaced by N and one or more H atoms may be replaced by halogen, CN, CH _3. CHF ₂ , CH ₂ F, OCH ₃ , OCHF ₂ or OCF ₃ substitution; cyclohexane-1,4-diyl, wherein in addition, one or two non-adjacent CH ₂ groups can be independently replaced by O and/or S replacement and one or more H atoms may be replaced by F; cyclohexene-1,4-diyl, bicyclo[1.1.1]pentane-1,3-diyl, bicyclo[2.2.2] Octane-1,4-diyl, spiro[3.3]heptane-2,6-diyl, tetrahydropyran-2,5-diyl or 1,3-dioctane-2,5-diyl , Z ⁰ independently represents a single bond, -CH ₂ O-, -(CO)O-, -CF ₂ O-, -CH ₂ CH ₂ CF ₂ O-, -CF ₂ CF ₂ -, -CH ₂ CF ₂ -, -CH ₂ CH ₂ -, -(CH ₂ ) ₄ -, -CH=CH-, -CH=CF-, -CF=CF- or -C≡C-, where asymmetric bridge The bond may be inserted in any orientation, X ¹ F, Cl, -CF ₃ or -OCF ₃ , and n represents 0, 1 or 2.