Ferroelectric nematic liquid crystal medium

Abstract

A ferroelectric nematic liquid crystal medium is provided. The novel LC media exhibit a ferroelectric nematic phase at ambient temperature. They contain at least one compound of the group of formula IA, formula IB, and formula IC-1 / IC-2 / IC-3, respectively, where the variables have the meanings indicated in the description and claims. The mixtures are useful in electro-optics, electronics, electromechanics, and other applications for materials with very high dielectric constants and other energy-saving applications. TIFF2023553865000104.tif185166

Description

[Technical Field]

[0001] An embodiment of the present invention relates to liquid-crystalline media which exhibit a ferroelectric nematic liquid-crystalline phase over a substantial temperature range, preferably at ambient temperature. These media preferably comprise one or more compounds of each of the formulae IA, IB and IC-1 to IC-3 as defined below. Additionally, the present invention relates to liquid-crystalline displays, electric and electronic devices which comprise the liquid-crystalline media according to the invention. [Background technology]

[0002] In recent years, the application fields of liquid crystal compounds have expanded significantly to various types of display devices, electro-optical devices, electronic components, sensors, etc. For this reason, particularly in the field of nematic liquid crystals, a large number of different structures have been proposed. Nematic liquid crystals have found the most widespread use to date in flat panel display devices. They have been employed in particular in passive TN or STN matrix displays or systems with TFT active matrices (including the well-known TN, IPS, FFS, and VA systems).

[0003] Most of these devices, including all common LCD television sets, LCD desktop monitors, and mobile LCD devices, employ a nematic liquid crystal phase. Several alternative liquid crystal phases are known, such as the ferroelectric smectic phase or blue phase. However, the ferroelectric nematic phase (N f The ferroelectric nematic phase (-LC phase) has been postulated theoretically for decades, without the discovery of suitable liquid crystal materials with such properties. Only recently have a few chemical structures been reported that exhibit a ferroelectric nematic phase.

[0004] First, Hiroya Nishikawa, Kazuya Shiroshita, Hiroki Higuchi, Yasushi Okumura, Yasuhiro Haseba, Shin-ichi Yamamoto, Koki Sago and Hirotsugu Kikuchi, Adv. Mater. (2017), Vol. 29, p. 1702354 (Non-Patent Document 1), describes a compound of formula A that exhibits ferroelectric nematic behavior at temperatures between about 45°C and 68°C.

[0005] [ka]

[0006] Furthermore, Nerea Sebastian, Luka Cmok, Richard J. Mandle, Maria Rosario de la Fuente, Irena Drevensek Olenik, Martin Copic and Alenka Mertelj, Physical Review Letters (2020), Vol. 124, p. 037801 (Non-Patent Document 2), describe a compound of formula B that has similar behavior at temperatures between about 120 ° C. and 133 ° C.

[0007] [ka]

[0008] Furthermore, N f A comparison of the only two materials available for LC phases is presented in Xi Chen et al., PNAS (June 23, 2020), Vol. 117 (No. 25), pp. 14021-14031 (Non-Patent Document 3). O.D. Lavrentovich, Proc Nat Acad Sci USA (2020), Vol. 117 (No. 26), pp. 14629-14631 (Non-Patent Document 4), presents a new N f The high significance of the -LC phase is emphasized.

[0009] Extremely high values ​​of the dielectric constant of these substances and some of their structural modifications have been reported in Li et al., Sci. Adv. 2021, Vol. 7 (Non-Patent Document 5).

[0010] A new ferroelectric nematic material of formula C was published in Atsutaka Manabe, Matthias Bremer, and Martin Kraska (2021): Ferroelectric phase at and below room temperature, Liquid Crystals, Vol. 48, pp. 1079-1086 (DOI 10.1080 / 02678292.2021.1921867) (Non-Patent Document 6), which shows a ferroelectric nematic liquid crystal phase (N f Ambient temperature, which may also be referred to as room temperature, is herein strictly defined as a temperature of 20°C.

[0011] [ka]

[0012] N for technical applications f Developing a -LC phase has obvious advantages due to its applicability to ambient temperatures: technical devices and electronic applications are usually designed to have a wide operating range above and below ambient temperature, e.g., 15°C to 25°C, preferably 0°C to 50°C, and more preferably even below ambient temperature.

[0013] A ferroelectric nematic display has been proposed in DE 19629551 A1, but no specific materials capable of fulfilling the required ferroelectric nematic properties are disclosed.

[0014] The use of fluorinated liquid crystal materials is known to those skilled in the art. Various compounds containing two 2,6-difluorinated 1,4-phenylene rings have already been described as liquid crystal or mesogenic materials, for example, in WO 2015 / 101405 (Patent Document 2) and elsewhere. The compounds proposed therein usually do not contain three 2,6-difluorinated phenylene rings in the same structural pattern and bridging groups such as (CO)O or CFO, and they have not been reported to have ferroelectric properties. Compounds containing two 2,6-difluorinated phenylene rings and a pyrimidine ring are disclosed in German Patent Application Publication No. 4409431 (Patent Document 3). Further pyrimidine ring and fluorinated phenylene-containing compounds are disclosed in European Patent Application Publication No. 2935513 (Patent Document 4) and International Patent Application Publication No. WO 2017 / 162707 (Patent Document 5). [Prior art documents] [Patent documents]

[0015] [Patent Document 1] German Patent Application Publication No. 19629551 [Patent Document 2] International Publication No. 2015 / 101405 [Patent Document 3] German Patent Application Publication No. 4409431 [Patent Document 4] European Patent Application Publication No. 2935513 [Patent Document 5] International Publication No. 2017 / 162707 [Non-patent literature]

[0016] [Non-Patent Document 1] Hiroya Nishikawa, Kazuya Shiroshita, Hiroki Higuchi, Yasushi Okumura, Yasuhiro Haseba, Shin-ichi Yamamoto, Koki Sago and Hirotsugu Kikuchi, Adv. Mater. (2017), Vol. 29, pp. 1702354 [Non-patent document 2] Nerea Sebastian, Luka Cmok, Richard J. Mandle, Maria Rosario de la Fuente, Irena Drevensek Olenik, Martin Copic and Alenka Mertelj, Physical Review Letters (2020), Volume 124, Page 037801 [Non-patent document 3] Xi Chen et al., PNAS (June 23, 2020), Volume 117 (No. 25), Pages 14021-14031 [Non-patent document 4] ODLavrentovich, Proc Nat Acad Sci USA (2020), Volume 117 (No. 26), Pages 14629-14631 [Non-patent document 5] Li et al., Sci.Adv. 2021, Vol. 7 [Non-patent document 6] Atsutaka Manabe, Matthias Bremer, Martin Kraska (2021): Ferroelectric phase at and below room temperature, Liquid Crystals, Volume 48, Pages 1079-1086 (DOI 10.1080 / 02678292.2021.1921867) DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0017] The object of the present invention is to provide a ferroelectric nematic liquid crystal phase medium (N fThe objective is to find novel and stable compounds suitable as components (one or more) of N-LC phase media. f -LC phase, N f -LC media, they must maintain such a phase. They must also have moderate to high optical anisotropy to achieve electro-optical switching effects similar to conventional nematic LC media.

[0018] In view of the very diverse fields of application of compounds of this type having high dielectric anisotropy (Δε), it was desirable to have further available compounds which exhibit a wide suitable temperature range of the ferroelectric nematic phase, while preferably having a high clearing point and a low melting point.

[0019] It was therefore a further object of the present invention to find novel stable compounds as component(s) of ferroelectric nematic liquid crystal media, in particular for displays similar to conventional nematic TN, STN, IPS, FFS and TN-TFT displays.

[0020] In addition, it was an aim that the compounds be thermally and photochemically stable under the conditions prevailing in the field of application: as mesogens, they must promote a broad mesogenic phase, preferably a nematic phase, especially at low temperatures, at least below room temperature. [Means for solving the problem]

[0021] Surprisingly, media containing several compounds selected as described below can achieve a ferroelectric phase in a highly favorable temperature range, and certain new and conventional compounds in combination exhibit N fIt has been found that these compounds are exceptionally well suited as components of LCD media. They can be used to obtain liquid crystal media with unprecedented properties, including, but not limited to, those for displays requiring particularly high or even extremely high dielectric anisotropy, in particular for IPS or FFS displays, but also for TN or STN displays, and for electronic applications, such as capacitors and electromechanical devices using high dielectric constants of materials. The media and compounds used according to the invention are sufficiently stable and colorless. In particular, they are distinguished by very high dielectric constants, in particular very high dielectric anisotropies (Δε), which, when used in optical switching elements, require much lower threshold voltages. The compounds have reasonably good solubility compared to compounds with comparable properties and are almost unlimitedly miscible with similar compounds. In addition, the compounds used according to the invention have high clearing points. These compounds also have relatively low melting points or can be stably maintained below their melting point as supercooled melts. The present invention allows the production of desirable N-type compounds already at room temperature or below. f -Allows for the formation of LC phases.

[0022] High dielectric constants enable outstanding physical performance. They are also particularly advantageous as dielectrics in capacitors, as they result in high capacitance over a specific electrode area. In addition, the media have very low electrical conductivity and, due to their fluidity, are superior to conventional high ε r It is more unique than materials (e.g., barium titanate).

[0023] The liquid-crystalline media can be used in displays based on the twist cell principle, the guest-host effect, the deformation effect of the alignment phases DAP or ECB (electrically controlled birefringence), the IPS (in-plane switching) effect or the dynamic scattering effect. [Brief explanation of the drawings]

[0024] [Figure 1]1 shows a graph depicting the dielectric properties of Example Mixture 1 over a temperature range of -40 to 110°C. The T / εr graph, measured at 10 Hz and a voltage of about 50 mV, shows the value of the relative permittivity εr upon cooling. Between about 5 and 55°C, the value of εr has a maximum value (plateau shape) and decreases rapidly towards higher temperatures. The maximum permittivity value of εr is 42400 at about 52°C. DETAILED DESCRIPTION OF THE INVENTION

[0025] In one main aspect, the present invention therefore relates to a liquid-crystalline medium comprising at least 15% by weight of one or more compounds of the formula IA, at least 15% by weight of one or more compounds of the formula IB and at least 15% by weight, preferably at least 20% by weight, of one or more compounds selected from the formulae IC-1 to IC-3.

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] During the ceremony X 1B represents -CN or -NCS, preferably -CN, X 1C represents -CN, F, CF3, -OCF3, -NCS, SF5 or O-CF=CF2, preferably -CN or F, most preferably CN, Z 1A and Z 1B represent, independently of one another, -(CO)-O- or -CF-O- or a single bond, preferably -(CO)-O- or -CF-O-, Z 2A and Z 2Brepresent, independently of one another, a single bond, —(CO)—O— or —CF—O—, preferably a single bond, Z 1C and Z 2C One of the two groups represents -(CO)-O- or -CF2-O-, and the other represents a single bond, and preferably Z 1C is -(CO)-O- or -CF2-O-, and Z 2C is a single bond, L 1A , L 1B and L 1C each independently represents H or CH3, preferably H, L 2A is F or H, preferably F, L 2C is F or H, preferably F, [ka] represents [ka] represents In the formula, L 8B represents alkyl, alkoxy or alkoxyalkyl having 1 to 7 C atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3 or CH2CH2CH2OCH3, [ka] represents [ka] represents m and n are 0, 1, or 2, with the proviso that (m+n) is 1; R 1A , R 1B and R 1Care each independently an alkyl group having 1 to 12, preferably 1 to 8, more preferably 1 to 6, most preferably 1 to 5 C atoms (provided that in addition, one or more CH groups in these groups may in each case be independently -C≡C-, -CF-O-, -OCF-, -CH=CH-, -C≡C-, -CF≡C-, -CF≡O-, -OCF≡-, -CH=CH-, -C≡C-, -CF≡O-, -OCF≡-, -CH=CH-, -C≡C-, -CF≡O-, -OCF≡-, -C≡C ... [ka] -O-, -S-, -(CO)-O- or -O-(CO)-, provided that in addition one or more H atoms may be replaced by halogen; Preferably R 1A , R 1B and R 1C are independently halogenated or unsubstituted alkyl groups having 1 to 10 C atoms, provided that in addition, one or more CH groups in these groups may be replaced by -O- or -CH=CH- in such a way that no O atom is directly connected.

[0030] Percentages are provided in the context that the entire vehicle constitutes 100% by weight of the vehicle.

[0031] The group R in each of the formulae IA, IB and IC-1 to IC-3 and their respective sub-formulae 1A , R 1B and R 1C preferably represents alkyl having 1 to 8 carbon atoms, alkoxy having 1 to 8 carbon atoms or alkenyl having 2 to 8 carbon atoms. These alkyl chains are preferably linear or they are preferably 1C In the case of R, it is preferably branched with a single methyl or ethyl substituent at the 2- or 3-position. 1A , R 1B and R 1C particularly preferably denotes a linear alkyl group having 1 to 7 C atoms or an unbranched alkenyl group having 2 to 8 C atoms, in particular an unbranched alkyl group having 1 to 5 C atoms.

[0032] Alternatively preferred groups R 1A , R 1B and R 1C is selected from cyclopentyl, 2-fluoroethyl, cyclopropylmethyl, cyclopentylmethyl, cyclopentylmethoxy, cyclobutylmethyl, 2-methylcyclopropyl, 2-methylcyclobutyl, 2-methylbutyl, 2-ethylpentyl and 2-alkyloxyethoxy.

[0033] Branched or substituted end groups R 1A , R 1B and R 1C Compounds of formulae IA, IB and IC1 to IC-3 containing, respectively, the group R 1A , R 1B and R 1C are each preferably linear.

[0034] base R 1A , R 1B and R 1C are each particularly preferably selected from the lower moiety.

[0035] [ka]

[0036] However, the following abbreviations are used for the end groups:

[0037] [ka]

[0038] A further embodiment of the present invention is directed to a ferroelectric nematic liquid crystal medium comprising one or more compounds selected from formulae IA, IB, IC-1, IC-2 and IC-3 as defined above.

[0039] A further embodiment of the present invention is directed to a ferroelectric nematic liquid crystal medium comprising one or more compounds of formula IC-3 as defined above, preferably of the preferred formulae in percentages as provided throughout the present disclosure.

[0040] In a preferred embodiment, the medium according to the invention preferably comprises one, two or more compounds of formula IA-1, preferably selected from the group of formulae IA-1 to IA-3, preferably of formula IA-1.

[0041] [ka]

[0042] [ka]

[0043] where the parameters have the respective meanings given above, preferably Z 1A represents -CF2-O-.

[0044] In a preferred embodiment, the medium according to the invention preferably comprises one, two or more compounds of formula IB-1 and / or IB-2, preferably of formula IB-1, preferably selected from the group of the following formulae, formulae IB-1-1 to IB-2-3:

[0045] [ka]

[0046] R 1B represents an alkyl group having 1 to 12, preferably 1 to 7, more preferably 1 to 6, most preferably 1 to 5 C atoms (provided that in addition, one or more CH groups in these groups may in each case independently be -C≡C-, -CF-O-, -OCF-, -CH=CH-, -C≡C-, -CF≡ ... [ka] -O-, -S-, -CO-O- or -O-CO-, provided that in addition one or more H atoms may be replaced by halogen; Preferably R 1B is a halogenated or unsubstituted alkyl radical having 1 to 12 C atoms, with the proviso that in addition, one or more CH groups in these radicals may in each case be replaced independently by -C≡C- or -CH=CH-, [ka] represents, and Z 1B , Z 2B independently represent -(CO)-O- or -CF2-O-.

[0047] [ka]

[0048] where the parameters have the respective meanings given above, and in particular in formulae IB-1-1 to IB-1-3, Z 1B preferably represents —CF—O—, and in particular in formulae IB-2-1 and IB-2-2, Z 2B preferably represents —CF—O—, and in particular in formula IB-2-3, Z 2B preferably represents —C(O)O—.

[0049] In a preferred embodiment, the medium according to the invention preferably comprises one, two or more compounds selected from the group of formulae IC-1-1-1 to IC-3-5-2, preferably selected from the group of formulae IC-1-1-1, IC-1-1-2, IC-1-1-3, IC-1-1-4, IC-3-1-1 and IC-3-2-1.

[0050] [ka]

[0051] In the formula, A 1C is defined as above.

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] where the parameters have the respective meanings given above, preferably L 1C represents H, Z 1C represents -CF2-O- or -(CO)-O-, and X 1C represents —CN or F, preferably —CN.

[0056] Particularly preferred compounds of the formulae IC-1-1 to IC-1-4 to be used in the medium are compounds of the following formulae:

[0057] [ka]

[0058] where the parameters are defined above, preferably L 1C is H.

[0059] In a preferred embodiment of the invention, the medium comprises up to 100% of one or more compounds, preferably 3, 4, 5 or 6 or more compounds selected from compound group 1, the group of compounds of formulae IA, IB and IC-1 / -2 / -3. In this embodiment, the medium preferably consists mainly of, more preferably consists essentially of and most preferably consists substantially completely of these compounds.

[0060] For purposes of the present invention, unless otherwise indicated in particular cases, the following definitions apply in connection with the identification of the components of the compositions.

[0061] "Contains": The concentration of the component in question in the composition is preferably 5% or more, particularly preferably 10% or more, very particularly preferably 20% or more.

[0062] "Consists mainly of": The concentration of the component of interest in the composition is preferably 50% or more, particularly preferably 55% or more, very particularly preferably 60% or more.

[0063] "Consists essentially of": The concentration of the component in question in the composition is preferably 80% or more, particularly preferably 90% or more, very particularly preferably 95% or more.

[0064] "Consists essentially completely of": The concentration of the component of interest in the composition is preferably 98% or more, particularly preferably 99% or more, very particularly preferably 100.0%.

[0065] Preferably, the medium according to the present application satisfies one or more of the following conditions:

[0066] 20% by weight or more of compounds of formula IA, more preferably 25% by weight or more, more preferably 27% by weight or more, most preferably 32% by weight or more of compounds of formula IA,

[0067] 17% by weight or more of compounds of formula IB, more preferably 20% by weight or more, more preferably 22% by weight or more, most preferably 25% by weight or more of compounds of formula IB,

[0068] 40% by weight or more of compounds selected from the formulae IA and IB, more preferably 45% by weight or more, more preferably 50% by weight or more, most preferably 55% by weight or more of compounds selected from the formulae IA and IB, i.e. the sum of the compounds of the formulae IA and IB is preferably at least

[0069] 20% by weight or more, preferably 25% by weight or more, of compounds selected from the formulae IC-1, IC-2 and IC-3, more preferably 28% by weight or more, more preferably 32% by weight or more, most preferably 34% by weight or more,

[0070] optionally 2% by weight or more of compounds of formula ID (ID-1, ID-2, ID-3, ID-4), more preferably 5% by weight or more, more preferably 10% by weight or more, most preferably 15% by weight or more of compounds of formula ID,

[0071] one, two or more, preferably three or more, compounds of formula IA-1-1, preferably of formula DUUQU-nF, most preferably selected from the group of compounds DUUQU-2-F, DUUQU-3-F, DUUQU-4-F and DUUQU-5-F and DUUQU-6-F,

[0072] one, two or more, preferably three or more, compounds of formula IB-1, preferably of formula GUUQU-nN and / or DUUQU-nN, most preferably selected from the group of the compounds GUUQU-2-N, GUUQU-3-N, GUUQU-4-N, GUUQU-5-N, GUUQU-6-N, GUUQU-7-N, DUUQU-2-N, DUUQU-3-N, DUUQU-4-N, DUUQU-5-N and DUUQU-6-N,

[0073] one, two or more compounds of formula IA-1-3, preferably of formula GUUQU-nF, more preferably selected from the group of compounds GUUQU-3-F, GUUQU-4-F and GUUQU-5-F,

[0074] one, two or more compounds of formula IB-1-3, preferably of formula DUUQU-nN, more preferably selected from the group of compounds DUUQU-3-N, DUUQU-4-N and DUUQU-5-N,

[0075] one, two or more compounds of formula IC-1-1, preferably of formula MUZU-nN or MUQU-nN, more preferably selected from the group of compounds MUZU-2-N, MUZU-3-N, MUZU-4-N and MUZU-5-N,

[0076] one, two or more compounds of formula IC-3, preferably selected from the group of formulae MUU-nN or UMU-nN, more preferably selected from the group of compounds MUU-3-N, MUU-4-N, MUU-5-F, UMU-3-N, UMU-4-N and UMU-5-N,

[0077] one, two or more compounds of formula IC-1-1, preferably selected from the group of formula GUZU-nN or GUQU-nN, more preferably selected from the group of compounds GUZU-3-N, GUZU-4-N, GUZU-5-F, GUQU-3-N, GUQU-4-N and GUQU-5-N,

[0078] and / or containing one, two or more compounds selected from the group of formulae IC-1-1-3 and IC-1-1-4, preferably compounds of formulae UUZU-nN and / or UUQU-nN, most preferably compounds UUZU-2-N, UUZU-3-N, UUZU-4-N, UUZU-5-N, UUQU-2-N, UUQU-3-N and UUQU-4-N,

[0079] wherein n is 1, 2, 3, 4, 5, 6, or 7.

[0080] In another preferred embodiment of the present invention, the compounds of formulae IA, IB and IC-1 / -2 / -3 are a first group of compounds, compound group 1. In this embodiment, the concentration of the compounds of compound group 1 is preferably 70% or more, preferably 80% or more, more preferably in the range of 90% or more to 100% or less.

[0081] In addition to the compounds of formulae IA, IB and IC-1 / -2 / -3, the media according to the invention optionally, preferably essentially, comprise one, two or more compounds selected from the formulae ID-1 to ID-4.

[0082] [ka]

[0083] X D represents CN, F, CF, -OCF, NCS, SF or O-CF=CF, preferably -CN, F, -CF, -OCF, -Cl or -NCS, most preferably F or CN, L 1D , L 2D , L 3D , L 4D , L 5D , L 6D and L 7Dindependently represent F, H, alkyl, alkoxy or alkoxyalkyl, each having 1 to 7 C atoms, preferably H, F, CH3, OCH3, OCH2CH3, CHOCH3, CHOCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3 or CH2CH2CH2OCH3, Z 1D and Z 2D are each independently -(CO)-O-, -CF2-O-, a single bond, and preferably both are -(CO)-O-, R 1D represents an alkyl group having 1 to 12 C atoms, preferably 1 to 7, more preferably 1 to 6, most preferably 1 to 5 C atoms (provided that in addition, one or more CH groups in these groups may in each case independently be -C≡C-, -CF-O-, -OCF-, -CH=CH-, -C≡C-, -CF≡ ... [ka] -O-, -S-, -(CO)-O- or -O-(CO)-, provided that in addition one or more H atoms may be replaced by halogen; Preferably R 1D is a halogenated or unsubstituted alkyl radical having 1 to 12 C atoms, with the proviso that in addition, one or more CH groups in these radicals may in each case be replaced independently by -C≡C- or -CH=CH-, R 2D represents alkyl, alkoxy or alkoxyalkyl, each having 1 to 7 C atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3 or CH2CH2CH2OCH3, [ka] represents L 8Drepresents alkyl, alkoxy or alkoxyalkyl, each having 1 to 7 C atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3 or CH2CH2CH2OCH3.

[0084] Preferably, it comprises one or more of formulae ID-1-1 to ID-3-1.

[0085] [ka]

[0086] where the variable group R 1D and L 8D is defined as above.

[0087] The medium may additionally contain one or more compounds selected from the following group of compounds:

[0088] The medium comprises, besides those of formulae IA, IB and IC-1 / IC-2 / IC-3, i.e., group 1 of compounds, one or more compounds selected from group 2 of compounds of formulae II and III, either alternatively or additionally, preferably in a concentration of more than 0% to 50% or less.

[0089] [ka]

[0090] During the ceremony, R 2 represents alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, preferably alkyl or alkenyl, [ka] represents L 21and L 22 represents H or F, preferably L 21 represents F, L 32 and L 33 represents H, F or CH3, preferably H, X 2 represents halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, preferably F, Cl, -OCF3, -O-CH2CF3, -O-CH=CH2, -O-CH=CF2 or -CF3, very preferably F, Cl, -O-CH=CF2 or -OCF3, m represents 0, 1, 2 or 3, preferably 1 or 2, particularly preferably 2, R 3 represents alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl, fluorinated alkenyl having 2 to 7 C atoms, preferably n-alkyl, cyclopropyl, cyclopentyl or alkenyl, [ka] and L 31 and L 32 are each independently H or F, preferably L 31 represents F, X 3 represents halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, F, Cl, -OCF3, -OCHF2, -O-CH2CF3, -O-CH=CF2, -O-CH=CH2 or -CF3, very preferably F, Cl, -O-CH=CF2, -OCHF2 or -OCF3, Z 3represents -CH2CH2-, -CF2CF2-, -COO-, trans-CH=CH-, trans-CF=CF-, -CHO- or a single bond, preferably -CH2CH2-, -COO-, trans-CH=CH- or a single bond, very preferably -(CO)O-, trans-CH=CH- or a single bond, n is 0, 1, 2 or 3, preferably 1, 2 or 3, particularly preferably 1, provided that each ring, preferably the phenylene ring, may be optionally substituted with one or two alkyl groups, preferably methyl and / or ethyl groups, preferably one methyl group, and However, the compounds of formulae IA, IB, IC-1 / -2 / -3 and ID are excluded from the compounds of formula II.

[0091] Again optionally either alternatively or additionally, one or more compounds selected from the group of compounds of formula IV and V (Group 3) are included, preferably at a concentration of greater than 0% to 15%.

[0092] [ka]

[0093] During the ceremony, R 41 and R 42 are independently R in formula II. 2 has the meaning given above for R 41 represents alkyl, and R 42 represents alkyl or alkoxy, or R 41 represents alkenyl, and R 42 represents alkyl, [ka] represents Preferably [ka] represents Z 41 and Z42 are independent of each other, and Z 41 when they occur twice, they also independently represent -CH2CH2-, -COO-, trans-CH=CH-, trans-CF=CF-, -CHO-, -CF2O-, -C≡C- or a 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 are, independently of each other, R 41 and R 42 has one of the meanings given for, preferably denotes alkyl having 1 to 7 C atoms, preferably n-alkyl, particularly preferably n-alkyl having 1 to 5 C atoms, alkoxy having 1 to 7 C atoms, preferably n-alkoxy, particularly preferably n-alkoxy having 2 to 5 C atoms, alkoxyalkyl having 2 to 7 C atoms, preferably having 2 to 4 C atoms, alkenyl or alkenyloxy, preferably alkenyloxy, [ka] Preferably [ka] represents Preferably [ka] represents and if present, preferably [ka] represents Z 51 ~Z 53 are each, independently of one another, -CH-CH-, -CH-O-, -CH=CH-, -C≡C-, -COO- or a single bond, preferably -CH-CH-, -CH-O- or a single bond, particularly preferably a single bond, i and j each independently represent 0 or 1; (i+j) preferably represents 0, 1 or 2, more preferably 0 or 1, most preferably 1; However, each ring, preferably the phenylene ring, may be optionally substituted with one or two alkyl groups, preferably methyl and / or ethyl groups, preferably one methyl group.

[0094] Again optionally and preferably essentially, either alternatively or additionally, one or more compounds, preferably two or more compounds, selected from the group of compounds of formulae I and VI to IX, group 4, preferably at a concentration of greater than 0% to 20%.

[0095] [ka]

[0096] During the ceremony, TIFF0007799690000040.tif248151, [ka] Preferably [ka] represents n represents 0 or 1, R 11 and R 12 each independently preferably represents an alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms (wherein one CH group may be replaced by a 1,2-cyclopropyl, 1,3-cyclopentyl or 1,3-cyclopentenylene group), an alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, preferably an alkyl, alkoxy, alkenyl or alkenyloxy, most preferably an alkyl, alkoxy or alkenyloxy, R 61 represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably a linear alkyl group, more preferably an n-alkyl group, most preferably propyl or pentyl, an unsubstituted alkenyl group having 2 to 7 C atoms, preferably a linear alkenyl group, particularly preferably an unsubstituted alkoxy group having 1 to 6 C atoms or an unsubstituted alkenyloxy group having 2 to 6 C atoms, R 62 represents an unsubstituted alkyl group having 1 to 7 C atoms, an unsubstituted alkoxy group having 1 to 6 C atoms, or an unsubstituted alkenyloxy group having 2 to 6 C atoms, l represents 0 or 1; R 71 represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably a linear alkyl group, more preferably an n-alkyl group, most preferably propyl or pentyl, an unsubstituted alkenyl group having 2 to 7 C atoms, preferably a linear alkenyl group, particularly preferably having 2 to 5 C atoms, R 72 represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms, an unsubstituted alkoxy group having 1 to 6 C atoms, preferably 1, 2, 3 or 4 C atoms, or an unsubstituted alkenyloxy group having 2 to 6 C atoms, preferably 2, 3 or 4 C atoms, [ka] represents R 81 represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably a linear alkyl group, more preferably an n-alkyl group, most preferably propyl or pentyl, or an alkenyl group having 2 to 7 C atoms, preferably a linear alkenyl group, particularly preferably having 2 to 5 C atoms, R 82represents an unsubstituted alkyl group having 1 to 7 C atoms, preferably 2 to 5 C atoms, an unsubstituted alkoxy group having 1 to 6 C atoms, preferably 1, 2, 3 or 4 C atoms, or an unsubstituted alkenyloxy group having 2 to 6 C atoms, preferably 2, 3 or 4 C atoms, [ka] Z 8 represents -(CO)-O-, -CH2-O-, -CF2-O- or -CH2-CH2-, preferably -(CO)-O- or -CH2-O-, o represents 0 or 1, R 91 and R 92 are, independently of each other, 72 has the meaning given to R 91 preferably denotes an alkyl group having 2 to 5 C atoms, preferably having 3 to 5 C atoms, R 92 preferably represents an alkyl or alkoxy group having 2 to 5 C atoms, more preferably an alkoxy group having 2 to 4 C atoms, or an alkenyloxy group having 2 to 4 C atoms, [ka] p and q each independently represent 0 or 1; (p+q) preferably represents 0 or 1, [ka] Alternatively, preferably, p=q=1, provided that each ring, preferably the phenylene ring, may be optionally substituted with one or two alkyl groups, preferably methyl and / or ethyl groups, preferably one methyl group; and, but especially [ka] is replaced by and with the proviso that compounds of formula VII are excluded from compounds of formula IX, and compounds of formula I are excluded from compounds of formula IX, respectively.

[0097] Again optionally and preferably essentially, either alternatively or additionally, one or more compounds, preferably two or more compounds selected from the group of compounds of formula B, group 5, preferably at a concentration of greater than 0% to 20%.

[0098] [ka]

[0099] During the ceremony [ka] [ka] represents n represents 1 or 2, preferably 1; R 1represents an alkyl group having 1 to 7 C atoms (wherein one or more CH groups, preferably one CH group, may each independently be replaced by -C≡C-, -CF2-O-, -OCF2-, -O-, -(CO)-O-, -O-(C=O)-, cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclopentenylene, preferably by cyclopropylene or 1,3-cyclopentylene, and preferably one CH group is replaced by a 1,2-cyclopropylene group, a 1,3-cyclopentylene group or a 1,3-cyclopentenylene group); alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, preferably alkyl or alkenyl (with the proviso that one -CH2- group may be replaced by cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,3-cyclopentenylene, preferably cyclopropylene or 1,3-cyclopentenylene, in such a way that the O atoms are not directly linked to one another, and in which one or more H atoms may be replaced by halogen), 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), more preferably F, Cl, CF3 or OCF3, However, each ring, preferably the phenylene ring, may be optionally substituted with one or two alkyl groups, preferably methyl and / or ethyl groups, preferably one methyl group.

[0100] A medium containing one or more compounds of groups 1 and 2 is preferred.

[0101] The corresponding starting materials can generally be easily prepared by those skilled in the art by synthetic methods known from the literature or are commercially available. The reaction methods and reagents used are in principle known from the literature. Further reaction conditions are exemplified by the examples. Further preferred process modifications not mentioned above are revealed by the examples or claims.

[0102] In the present disclosure, the 2,5-disubstituted dioxane ring of the formula: [ka] Preferably, the dioxane ring is in the 2,5-trans configuration, i.e., the substituents R are both equatorial in the preferred chair conformation. 2,5-disubstituted tetrahydropyrans of the formula: [ka] Likewise, it preferably represents a tetrahydropyran ring in the 2,5-trans configuration, ie, the substituents are preferably both equatorial in the preferred chair conformation.

[0103] The liquid-crystalline media according to the present invention have a wide temperature range of the ferroelectric nematic phase. They exhibit a ferroelectric nematic phase range above and below 20°C (ambient temperature). They span the range of most technical interest, from at least 10 to 50°C and significantly beyond, even lower and / or higher temperatures. This makes them suitable for all types of domestic or industrial use, even outdoors with certain limitations. The media exhibit a ferroelectric nematic phase over a temperature range of at least 20 Kelvin or more, more preferably over 30 Kelvin or more, and most preferably over 40 Kelvin or more. The achievable combinations of ferroelectric nematic phase temperature range, clearing point, low-temperature stability (LTS), (specific) dielectric constant, dielectric anisotropy, and optical anisotropy, including compounds of formulae IA, IB, and IC-1 / -2 / -3, are far superior to previous materials of this type from the prior art. Previously, only a limited selection of single-compound materials with limited ferroelectric nematic phase ranges were available.

[0104] In addition, the mixtures according to the invention generally exhibit a very wide nematic phase range with clearing points above 65°C.

[0105] The liquid-crystalline media according to the invention preferably exhibit a temperature range of the ferroelectric nematic phase that is at least 20 degrees wide, which preferably extends over a range of at least 40 degrees, more preferably at least 60 degrees.

[0106] The liquid crystal medium according to the present invention preferably exhibits a ferroelectric nematic phase at temperatures of 10°C to 30°C, more preferably 10°C to 40°C, more preferably 10°C to 50°C, more preferably 0°C to 50°C, and most preferably -10°C to 50°C.

[0107] In another preferred embodiment, the liquid crystal medium according to the present invention exhibits a ferroelectric nematic phase preferably at 10°C to 40°C, more preferably at 10°C to 50°C, more preferably at 10°C to 60°C, most preferably at 10°C to 70°C.

[0108] The liquid-crystalline media according to the invention exhibit outstanding dielectric properties.

[0109] Due to its outstanding properties, the medium can function in many new technological fields and may be used for electro-optical purposes, for electromechanical devices including supercapacitors, nonlinear optical elements, sensors for electric fields, memory devices, and generators (i.e., energy harvesting devices) and actuators. The material may, for example, enable unconventional modes of energy harvesting from vibrational motion.

[0110] The medium according to the present invention preferably has an ε of 700 or more, more preferably 800 or more, more preferably 15,000, even more preferably 30,000 or more, more preferably 35,000 or more. r (at 20°C and 10 Hz).

[0111] These dielectric properties are achieved at a temperature where the medium is in the ferroelectric nematic phase. Dielectric properties may exhibit hysteretic behavior, particularly with respect to temperature, in which case the value obtained at a given temperature may depend on the history of the material, i.e., whether it has been heated or cooled.

[0112] This effect allows operation of the device in, for example, a bistable mode, which can be used beneficially in electro-optical devices, as known from, for example, ferroelectric smectic devices, among others.

[0113] The liquid-crystalline media according to the invention preferably contain from 2 to 40, particularly preferably from 4 to 20, compounds as further components in addition to one or more compounds according to the invention. In particular, these media may contain from 1 to 25 components in addition to one or more compounds according to the invention. These further components are preferably selected from ferroelectric nematic or nematogenic (monotropic or isotropic) substances.

[0114] Prior art ferroelectric materials and similar compounds with high dielectric constants for combination with the present material are selected, for example, from the following structures:

[0115] [ka]

[0116] The medium according to the invention preferably comprises from 1% to 100%, more preferably from 10% to 100%, particularly preferably from 50% to 100% of compounds of the formulae IA and / or IB and / or IC-1 / IC-2 / IC-3 which are preferably used according to the invention.

[0117] The present invention also relates to a process for the preparation of the liquid-crystalline media described herein, in which at least 15% by weight of one or more compounds of formula IA, 15% by weight of one or more compounds of formula IB and 15% by weight of one or more compounds of formula IC-1 / 2 / -3 are mixed, respectively, with each other and with any other components or additives, such that the resulting mixture amounts to 100% by weight.

[0118] The liquid crystal mixtures according to the present invention can be prepared by conventional methods. Generally, the desired amount of the component to be used in a smaller amount is dissolved in the component constituting the main component, preferably at elevated temperatures. It is also possible to mix solutions of the components in organic solvents, such as acetone, chloroform or methanol, and then, after thorough mixing, remove the solvent again, for example by distillation. It is also possible to prepare the mixtures by other conventional methods, such as using premixes, for example, homologous mixtures, or using the so-called "multi-bottle" system.

[0119] The dielectric may also contain further additives known to those skilled in the art and described in the literature. For example, pleochroic dyes, chiral dopants, stabilizers, or nanoparticles may be added in amounts of 0-15%, preferably 0-10%. The individual compounds added are used in concentrations of 0.01-6%, preferably 0.1-3%. However, in this specification, the concentration data for the other components of the liquid crystal mixture, i.e., the liquid crystals and mesogenic compounds, are given without taking into account the concentrations of these additives.

[0120] The liquid crystal mixtures according to the invention make it possible to significantly widen the range of available parameters.

[0121] The invention also relates to electro-optical displays containing media of this type (in particular TFT displays having two plane-parallel outer plates which together with a frame form a cell, an integrated nonlinear element for switching individual pixels on the outer plates, and a nematic liquid crystal mixture with positive dielectric anisotropy and high resistivity arranged within the cell), and to the use of these media for electro-optical purposes.

[0122] The term "alkyl" embraces unbranched and branched alkyl radicals having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, particularly preferably the unbranched radicals methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl and n-heptyl, and also the radicals n-butyl, n-pentyl, n-hexyl and n-heptyl, which are alternatively substituted by one methyl, ethyl or propyl. Radicals having 1 to 5 carbon atoms are generally preferred.

[0123] The term "alkenyl" embraces unbranched and branched alkenyl groups having up to 12 carbon atoms, in particular unbranched groups. Particularly preferred alkenyl groups are C2-C7-1E-alkenyl, C4-C7-3E-alkenyl, C5-C7-4-alkenyl, C6-C7-5-alkenyl and C7-6-alkenyl, in particular C2-C7-1E-alkenyl, C4-C7-3E-alkenyl and C5-C7-4-alkenyl. Examples of preferred alkenyl groups are vinyl, 1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl, 3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl, 4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl, etc. Groups having 2 to 5 carbon atoms are generally preferred.

[0124] The expression "halogenated alkyl group" preferably includes mono- or polyfluorinated and / or chlorinated groups. Perhalogenated groups are included. Fluorinated alkyl groups are particularly preferred, in particular CF3, CH2CF3, CH2CHF2, CHF2, CH2F, CHFCF3 and CF2CHFCF3. The expression "halogenated alkenyl group" and related expressions are explained accordingly.

[0125] The structure of the matrix display according to the invention from polarizers, electrode substrates and surface-treated electrodes corresponds to the conventional design for this type of display, the term conventional design being used broadly in this document and including all derivatives and modifications of matrix displays, in particular matrix display elements based on poly-Si TFTs.

[0126] However, the essential difference between a display according to the invention and a display based on a conventional twisted nematic cell lies in the choice of liquid crystal parameters of the liquid crystal layer.

[0127] The following examples are intended to illustrate the present invention without intending to limit it, and those skilled in the art will be able to obtain details from the examples that are not specifically given in the general description, and will be able to generalize them according to their general expertise and apply them to specific problems.

[0128] Above and below, percentage data are expressed as % by weight. Unless otherwise specified, for example, melting point T(C,N), smectic (Sm) to nematic (N) phase transition T(S,N) and clearing point T(N,I), respectively, T(N f All temperature values ​​given in this application, such as (°C), (°F), ...

[0129] The physical, physicochemical and electro-optical parameters are determined in a generally known manner, as described, inter alia, in the document "Merck Liquid Crystals - Licristal® - Physical Properties of Liquid Crystals - Description of Measurement Methods", 1998, Merck KGaA, Darmstadt.

[0130] The appearance of the ferroelectric nematic phase in the material is identified using differential scanning calorimetry (DSC) and by observing the texture under a polarized light microscope equipped with a hot stage for controlled cooling or heating, respectively, and also by the temperature dependence of the dielectric properties. The transition temperature is primarily determined by detecting the optical behavior under a polarized light microscope.

[0131] The dielectric anisotropy Δε of the individual substances is determined at 20 °C and 1 kHz. For this purpose, 5-10% by weight of the substance to be examined and measured is dissolved in the dielectrically positive mixture ZLI-4792 (Merck) and the measured value is extrapolated to a concentration of 100%. The optical anisotropy Δn is determined at 20 °C and a wavelength of 589.3 nm.

[0132] The relative permittivity (ε) of the material, especially in the ferroelectric nematic phase r ) is determined directly by measuring the capacitance of at least one test cell containing the compound, with a cell thickness of 250 μm and homeotropic and homogeneous orientation, respectively. The temperature is controlled by a Novocontrol Novocoool system set, with a temperature gradient of + / - 1 K / min; + / - 2 K / min; + / - 5 K / min; and + / - 10 K / min applied to the sample cell. The capacitance is measured with a Novocontrol α-N analyzer at a frequency of 1 kHz or 10 Hz, with a standard voltage stepping down from less than 50 mV to 0.1 mV, below the threshold of the measured compound. Measurements are performed both during heating and cooling of the sample (single or multiple samples).

[0133] In this application, unless expressly stated otherwise, the plural of a term refers to both the singular and the plural, and vice versa. Further combinations of the embodiments and variations of the invention according to the detailed description arise from the appended claims or from multiple combinations of these claims. [Example]

[0134] The invention will now be described in more detail in the following non-limiting examples.

[0135] Compound example <Compound Example 1>: Synthesis of UUQU-4-N

[0136] [ka]

[0137] Process 1.1

[0138] [ka]

[0139] 13.8 g (35 mmol) of 1 was dissolved in 150 ml of 1,4-dioxane, and 1.0 g (1.4 mmol) of palladium acetate, 10.4 g (0.1 mol) of potassium acetate, and 13.9 g (53 mmol) of bis(pinacolato)boron were added. The mixture was heated under reflux overnight. After the usual workup, 12.4 g (80%) of 2 was obtained as slightly yellow crystals.

[0140] Process 1.2

[0141] [ka]

[0142] 5.4 g (23 mmol) of potassium phosphate was dissolved in 10 ml of water. 80 ml of toluene, 2.8 g (11.4 mmol) of 1-bromo-2,6-difluoro-4-butylbenzene 3, 6.3 g (14.2 mmol) of 1, 42.2 mg (0.2 mmol) of palladium acetate, and 126.7 mg (0.3 mmol) of S-Phos (2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl) were added, and the mixture was heated under reflux overnight. After the usual workup, 3.42 g (62%) of 3 (UUQU-4-N) was obtained as colorless, transparent crystals.

[0143] 1H NMR (400MHz, chloroform-d) δ7.16 (d, J=11.0Hz, 2H), 7.07~6.99 (m, 2H), 6.91~6.81 (m, 2H) ), 2.69~2.61(m, 2H), 1.69~1.57(m, 2H), 1.39(h, J=7.4Hz, 2H), 0.96(t, J=7.3Hz, 3H).

[0144] Melting point: 44℃ Unitropic ferroelectric nematic when cooled: below 21°C Extrapolated data from a 10% solution in ZLI-4792: Δn(20° C.)=0.120 and Δε(20° C.)=54.6.

[0145] <Compound Example 2>: Synthesis of UUZU-4-N

[0146] [ka]

[0147] Process 2.1

[0148] [ka]

[0149] 57.2 g (150 mmol) of disodium tetraborate decahydrate, 2.8 g (4 mmol) of palladium chloride, 0.2 g (4 mmol) of hydrazinium hydroxide, 39.4 g (0.2 mol) of 1-bromo-3,5-difluorobenzene, 42.8 g (0.2 mol) of 5, and 200 ml of water were combined. The mixture was heated under reflux for 6 hours. After the usual workup, 50 g (88%) of 6 was obtained.

[0150] Process 2.2

[0151] [ka]

[0152] 50 g (175 mmol) of 6 was dissolved in 300 ml of tetrahydrofuran and cooled to -75 °C. 118 ml (193 mmol) of 15% n-butyl ether in hexane was added dropwise at -70 °C, and the mixture was stirred at that temperature for 1.5 hours. The mixture was poured onto 500 g of solid carbon dioxide and allowed to warm to room temperature. After the usual workup, 46.8 g (82%) of 7 was obtained as colorless crystals.

[0153] Process 2.3

[0154] [ka]

[0155] 16.3 g (50 mmol) of 7, 8.5 g (55 mmol) of 1-cyano-2,6-difluoro-4-hydroxybenzene, and 611 mg (5 mmol) of 4-dimethylaminopyridine were combined with 200 ml of dichloromethane and cooled to 0 °C. Between 0 °C and 5 °C, a solution of 11.3 g (55 mmol) of N,N-dicyclohexylcarbodiimide in 50 ml of dichloromethane was added dropwise. The mixture was then warmed to room temperature and stirred overnight. 1.4 g of oxalic acid was added, and the whole was stirred for an additional 1.5 hours. After the usual workup, 20.5 g (88%) of 8 (UUZU-4-N) was obtained.

[0156] 1 H NMR (500MHz, chloroform-d) δ7.23~7.17(m, 2H), 7.15~7.08(m, 2H), 6.91~6.83(m, 2H), 2.69~2.62(m, 2H), 1.69~1.59(m, 2H), 1.39(h, J=7.4Hz, 2H), 0.96(t, J=7.4Hz, 3H).

[0157] Phase: C69N f / N93I. Extrapolated data from a 10% solution in ZLI-4792: Δn(20° C.)=0.159 and Δε(20° C.)=70.3.

[0158] Further combinations of the embodiments of the invention and modifications of the invention are also disclosed by the claims.

[0159] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting in any way to the remainder of the disclosure. The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and / or operating conditions of the invention for those used in the preceding examples.

[0160] From the foregoing description, those skilled in the art can easily ascertain the essential features of the present invention, and can make various modifications and changes to adapt the present invention to various uses and conditions without departing from the spirit and scope thereof.

[0161] This applies both to the medium as a composition having components which may be groups of compounds and individual compounds of the composition, and also to groups of compounds having their respective components and compounds. As far as the concentration of individual compounds relative to the medium as a whole is concerned, the term "comprising" means that the concentration of the compound(s) or compounds in question is preferably 1% or more, particularly preferably 2% or more, very particularly preferably 4% or more.

[0162] In the present invention, "≦" means less than or equal to, preferably less than, and "≧" means greater than or equal to, preferably greater than.

[0163] In the present invention, [ka] represents trans-1,4-cyclohexylene, [ka] represents a mixture of both cis- and trans-1,4-cyclohexylene, [ka] represents 1,4-phenylene.

[0164] In 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 Δε < -1.5. The dielectric anisotropy of a compound is determined herein by dissolving 10% of the compound in a liquid crystal host and determining the capacitance of the resulting mixture at 1 kHz in at least one test cell with a cell thickness of 20 μm and in each case with homeotropic and homogeneous surface alignment. The measurement voltage is typically between 0.5 V and 1.0 V, but is always lower than the capacitance threshold of the respective liquid crystal mixture (material) under consideration.

[0165] The host mixture used for the dielectrically positive and dielectrically neutral compounds is ZLI-4792, and the host mixture used for the dielectrically negative compounds is ZLI-2857, both manufactured by Merck, Germany. The value for each compound studied is obtained from the change in the dielectric constant of the host mixture after adding the compound studied and is extrapolated to 100% for the compound used. The compound studied is dissolved in the host mixture in an amount of 10%. If the solubility of the substance is too low for this purpose, the concentration is reduced stepwise by half until the study can be carried out at the desired temperature.

[0166] The liquid-crystalline medium according to the present invention may also contain further additives, such as stabilizers, in the usual amounts, if necessary. The total amount of these additives used is preferably from 0% to 10%, particularly preferably from 0.1% to 6%, based on the total amount of the mixture. The concentration of each compound used is preferably from 0.1% to 3%. The concentrations of these and similar additives are generally not taken into account when specifying the concentration and concentration range of the liquid-crystalline compound in the liquid-crystalline medium.

[0167] For the purposes of the present invention, all concentrations are given in percent by weight unless expressly stated otherwise and relate to the corresponding mixture as a whole or to the entire mixture components unless expressly stated otherwise. In this context, the term "mixture" describes a liquid-crystalline medium.

[0168] Unless otherwise stated, the following symbols are used: T(N,I) respectively T(N f ,I) (or clp.) Clearing point (℃).

[0169] Dielectric properties at 1 kHz and preferably at 20°C or each specified temperature: ε ⊥ Permittivity perpendicular to the director, ε ∥ Dielectric constant parallel to the director, Δε for dielectric anisotropy and especially for single compound selection data.

[0170] and specifically for data from screening of the respective compounds in the nematic host mixture ZLI-4792: n e extraordinary refractive index measured at 20°C and 589 nm, n0Normal refractive index measured at 20°C and 589 nm, and Δn Optical anisotropy measured at 20°C and 589 nm.

[0171] The following examples are intended to illustrate the present invention without limiting it. However, the following examples will provide those skilled in the art with the preferred compounds to be used, their respective concentrations and their combinations with each other, as well as preferred mixing concepts. In addition, the following examples illustrate the feasible properties and property combinations.

[0172] Definitions of structural elements by abbreviation for use in acronyms for chemical compounds.

[0173] <Table A: Ring elements>

[0174] [Table 1]

[0175] [Table 2]

[0176] [Table 3]

[0177] <Table B: Crosslinking Units>

[0178] [Table 4]

[0179] <Table C: Terminal group>

[0180] [Table 5]

[0181] where n and m each represent an integer and the three dots "..." are spaces for other abbreviations from the table.

[0182] In addition to the compounds of the formulae IA, IB and IC-1 / -2 / -3, the mixtures according to the invention preferably comprise one or more of the compounds mentioned below.

[0183] The following abbreviations are used: (n, m, k and l are each independently an integer, preferably 1 to 9, more preferably 1 to 7; k and l can be 0, preferably 0 to 4, more preferably 0 or 2, and most preferably 2; n is preferably 1, 2, 3, 4 or 5; in the combination "-nO-", it is preferably 1, 2, 3 or 4, more preferably 2 or 4; m is preferably 1, 2, 3, 4 or 5; in the combination "-Om", it is preferably 1, 2, 3 or 4, more preferably 2 or 4. The combination "-lVm" is preferably "2V1".)

[0184] In the present invention and the following examples, the structures of liquid crystal compounds are represented by acronyms, and conversion to chemical formulas is performed according to Tables A to C above. 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 alkenyl groups having n, m and l C atoms, respectively. Preferably, n, m and l are each, independently of one another, 1, 2, 3, 4, 5, 6 or 7. Table A shows the codes for the ring elements of the core structure of the compounds, Table B lists the bridging groups, and Table C lists the meaning of the codes for the left and right terminal groups of the molecule. The initial letter consists of the code for the ring element with any linking groups, followed by a first hyphen and the code for the left terminal group, and a second hyphen and the code for the right terminal group. Table D shows exemplary structures of the compounds with their respective abbreviations.

[0185] Examples of preferred compounds of formula IA

[0186] [Table 6]

[0187] Examples of preferred compounds of formula IB

[0188] [Table 7]

[0189] Examples of Preferred Compounds of Formula IC

[0190] [Table 8]

[0191] Examples of preferred compounds of formula IC-3

[0192] [Table 9]

[0193] Optionally used further compounds

[0194] [Table 10]

[0195] [Table 11]

[0196] [Table 12]

[0197] [Table 13]

[0198] [Table 14]

[0199] <Mixture example> Exemplary mixtures are disclosed below.

[0200] <Mixture example 1> The following mixture (M-1) is prepared and studied:

[0201] [Table 15]

[0202] <Mixture example 2> The following mixture (M-2) is prepared and studied:

[0203] [Table 16]

[0204] <Mixture example 3> The following mixture (M-3) is prepared and studied:

[0205] [Table 17]

[0206] These are the relative permittivity ε of all physical substances known to the authors so far. r It is the highest value among

[0207] <Mixture example 4> The following mixture (M-4) is prepared and studied:

[0208] [Table 18]

[0209] <Mixture example 5> The following mixture (M-5) is prepared and studied:

[0210] [Table 19]

[0211] <Mixture example 6> The following mixture (M-6) is prepared and studied:

[0212] [Table 20]

[0213] <Mixture example 6> The following mixture (M-6) is prepared and studied:

[0214] [Table 21]

[0215] <Mixture example 7> The following mixture (M-7) is prepared and studied:

[0216] [Table 22]

[0217] <Mixture example 8> The following mixture (M-8) is prepared and studied:

[0218] [Table 23]

[0219] <Mixture example 9> The following mixture (M-9) is prepared and studied:

[0220] [Table 24]

[0221] <Mixture example 10> The following mixture (M-10) is prepared and studied:

[0222] [Table 25]

[0223] <Mixture example 11> The following mixture (M-11) is prepared and studied:

[0224] [Table 26]

[0225] <Mixture example 12> The following mixture (M-12) is prepared and studied:

[0226] [Table 27]

[0227] <Mixture example 13> The following mixture (M-13) is prepared and studied:

[0228] [Table 28]

[0229] <Mixture example 14> The following mixture (M-14) is prepared and studied:

[0230] [Table 29]

[0231] <Device example 1> A capacitor containing two glass substrates with ITO electrodes is filled with a 110 μm layer of dielectric consisting of the medium of Mixing Example 1. Using a 10 Hz AC voltage, a capacitance of 1.41 μF is determined. The resulting relative permittivity (ε r) is 4.2 10 4 is.

Claims

1. 15% by weight or more of one or more compounds of formula IA, 15% by weight or more of one or more compounds of formula IB, and 15% by weight or more of one or more compounds selected from formulae IC-1 to IC-3; A liquid-crystalline medium, wherein the total concentration of the compounds of the formulae IA, IB and IC-1 to IC-3 is within the range of 80 to 100% by weight. 【Chemistry 1】 (In the formula, X １Ｂ represents -CN or -NCS, X １Ｃ is -CN, F, CF ３ , -OCF ３ , -NCS, SF ５ or O-CF=CF2, Z １Ａ and Z １Ｂ are each independently —(CO)—O— or —CF ２ represents —O— or a single bond, Z ２Ａ and Z ２Ｂ are each independently a single bond, —(CO)—O— or —CF ２ represents —O—, Z １Ｃ and Z ２Ｃ One of the two groups is —(CO)—O— or —CF ２ -O- and the other represents a single bond; L １Ａ , L １Ｂ and L １Ｃ are each independently H or CH ３ represents L ２Ａ is F or H, L ２Ｃ is F or H, 【Chemistry 2】 represents 【Transformation 3】 represents In the ceremony, L ８Ｂ represents alkyl, alkoxy or alkoxyalkyl having 1 to 7 C atoms, 【Chemistry 4】 represents 【Transformation 5】 represents m and n are 0, 1, or 2, provided that (m+n) is 2; R １Ａ , R １Ｂ and R １Ｃ are each independently an alkyl group having 1 to 12 carbon atoms (provided that in addition, one or more CH ２ The groups may be in each case independently of one another, such that the O / S atoms are not directly linked to one another, such as -C≡C-, -CF ２ -O-, -OCF ２ -, -CH=CH-, 【Transformation 6】 -O-, -S-, -(CO)-O- or -O-(CO)-, provided that in addition one or more H atoms may be replaced by halogen.

2. 2. A liquid-crystalline medium according to claim 1, which exhibits a ferroelectric nematic phase.

3. A relative dielectric constant ε of 700 or more at 20°C and 1 kHz ｒ 3. The liquid-crystalline medium according to claim 1, wherein

4. 4. The liquid-crystalline medium according to claim 1, which comprises one, two or more compounds selected from the formulae IC-1-3 to IC-3-5. 【Transformation 7】 5. The liquid-crystalline medium according to claim 1, comprising one or more compounds of the formula IC-1-1 as compounds of the formula IC-1. 【Transformation 8】 6. The liquid crystal medium according to claim 5, comprising, as the compound of formula IC-1-1, one or more compounds selected from the compounds of formulae IC-1-1-1 to IC-1-1-4. 【Chemistry 9】 7. The liquid crystal medium according to claim 1, comprising, as the compound of formula IC-3, one or more compounds selected from the group consisting of compounds of formula IC-3-1 and IC-3-2. 【Chemistry 10】 8. The liquid-crystalline medium according to claim 7, characterized in that the compound of formula IC-3-1 comprises one or more compounds of formula IC-3-1-1. 【Chemistry 11】 9. The liquid-crystalline medium according to claim 7, characterized in that it contains one or more compounds of the formula IC-3-2-1 as compounds of the formula IC-3-2. 【Chemistry 12】

10. A medium according to any one of claims 1 to 9, which exhibits a ferroelectric nematic phase at a temperature of at least 10°C to 30°C.

11. The compound of formula IC-1 comprises one or more compounds selected from formulas IC-1-1-1 to IC-1-1-4, The compound of formula IC-3 includes one or more compounds selected from the compounds of formula IC-3-1-1 or IC-3-2-1, 5. A liquid-crystalline medium according to claim 1, which exhibits a ferroelectric nematic phase at least at a temperature of from 10°C to 30°C. 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】

12. A medium according to any one of claims 1 to 11, which exhibits hysteresis of its dielectric properties with temperature change.

13. A medium according to any one of claims 1 to 12, which exhibits a ferroelectric nematic phase over a temperature range of at least 20 Kelvin.

14. Use of a liquid-crystalline medium according to any one of claims 1 to 13 for electro-optical purposes, for electromechanical devices, including supercapacitors and generators and actuators.

15. Use of a liquid-crystalline medium according to any one of claims 1 to 13 for a supercapacitor.

16. Use of a liquid-crystalline medium according to any one of claims 1 to 13 for non-linear optical elements, sensors or memory devices.

17. Use of a liquid-crystalline medium according to any one of claims 1 to 13 for energy-saving applications.

18. Electro-optical liquid crystal display comprising a liquid crystal medium according to any one of claims 1 to 13.

19. 14. A process for preparing a liquid-crystalline medium according to any one of claims 1 to 13, comprising combining and mixing at least one or more compounds of the formula IA, one or more compounds of the formula IB and one or more compounds selected from the formulae IC-1 to IC-3, respectively, with each other and with other components or additives.

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