Ferroelectric nematic liquid crystal medium

Abstract

A new LC medium exhibits a ferroelectric-nematic phase at ambient temperature. It comprises at least one or more compounds selected from each of the groups of formula IA, IB and IC-1 / IC-2 / IC-3, wherein the variable groups have the meanings indicated in the text and claims. The mixture can be used in electro-optics, electronics, electromechanics and other applications for materials with very high dielectric permittivity and other energy saving applications.

Description

[0001] One aspect of the present invention relates to liquid crystal media exhibiting a ferroelectric nematic liquid crystal phase over a considerable temperature range, preferably at ambient temperature. Preferably, these media comprise one or more compounds having each of the formulas IA, IB, and IC-1 to IC-3 as defined below. Furthermore, the present invention relates to liquid crystal displays, electrical components, and electronic components containing liquid crystal media according to the present invention.

[0002] Over the past few years, the application areas of liquid crystal compounds have expanded significantly to various types of display devices, electro-optical devices, electronic components, sensors, and more. For this reason, many different structures have been proposed, especially in the field of nematic liquid crystals. Currently, nematic liquid crystal compounds are found to be most widely used in flat panel display devices. In particular, they have been used in passive TN or STN matrix displays or systems with TFT active matrices, including well-known TN, IPS, FFS, and VA systems.

[0003] Most of these devices utilize nematic liquid crystal phases, including all common LCD televisions, LCD desktop monitors, and mobile LCD devices. Some alternative liquid crystal phases are known, such as ferroelectric smectic phases or blue phases. However, for decades, ferroelectric nematic phases (N...) have been the preferred choice. f The LC phase is merely a theoretical assumption, and no suitable liquid crystal material with this property has been found. Until recently, only a few chemical structures exhibiting ferroelectric nematic behavior have been reported.

[0004] Hiroya Nishikawa, Kazuya Shiroshita, Hiroki Higuchi, Yasushi Okumura, Yasuhiro Haseba, Shin-ichi Yamamoto, Koki Sago and Hirotsugu Kikuchi, Adv. Mater. (2017), 29, 1702354. The compound of formula A was first described to exhibit ferroelectric nematic behavior at temperatures between about 45 °C and 68 °C.

[0005]

[0006] In addition, Nerea Sebastián, Luka Cmok, Richard J. Mandle, María Rosario de la Fuente, Irena Olenik, Martin Alenka Mertelj, Physical Review Letters (2020), 124, 037801, also describes compounds of formula B that exhibit similar behavior between about 120 °C and 133 °C.

[0007]

[0008] Xi Chen et al., PNAS (June 23, 2020), 117(25)14021-14031. This relates to the two only available N... f Further comparisons were made of materials in the -LC phase. ODLavrentovich, ProcNatAcadSciUSA (2020), 117(26), 14629-14631. Emphasis was placed on the new N. f -The significance of the appearance of the LC phase.

[0009] The extremely high dielectric polarizability values ​​of these materials and some of their structural variations are reported in the publication Li et al., Sci. Adv. 2021, 7.

[0010] Atsutaka Manabe, Matthias Bremer, Martin Kraska (2021): Ferroelectric phase at and below room temperature, Liquid Crystals, 48, 1079-1086 (DOI 10.1080 / 02678292.2021.1921867) discloses a novel ferroelectric nematic material of formula C, which is described as having a ferroelectric nematic liquid crystal phase (N) close to ambient temperature. f -LC phase). Ambient temperature, sometimes also called room temperature, here in a narrow sense refers to a temperature of 20°C.

[0011]

[0012] N for technical applications f The development of -LC phases will clearly benefit from adaptability to ambient temperatures. Technical devices and electronic applications are typically designed to have operating ranges above and below ambient temperatures, or room temperature, for example from 15°C to 25°C, preferably from 0°C to 50°C, and more preferably even wider.

[0013] DE19629551 A1 proposes a ferroelectric nematic display; however, it does not disclose any specific material that can satisfy the required ferroelectric nematic properties.

[0014] The uses of fluorinated liquid crystal materials are known to those skilled in the art. Various compounds containing two 2,6-difluorinated 1,4-phenylene rings have been described as liquid crystal or mesocrystalline materials, such as those disclosed in WO 2015 / 101405 A1 and various other disclosures. The compounds presented therein generally do not contain three 2,6-difluorinated phenylene rings and a bridging group, such as (CO)O or CF2O, in the same structural mode, and have not been reported to possess any ferroelectric properties. DE4409431 A1 discloses compounds containing two 2,6-difluorinated phenylene rings and a pyrimidine ring. EP 2935513A1 and WO 2017162707 A1 disclose other compounds containing a pyrimidine ring and fluorinated phenylene.

[0015] The objective of this invention is to discover a suitable medium for ferroelectric nematic liquid crystals (N... f A novel, stable compound comprising components of an LC phase medium. In particular, the compound should simultaneously possess N... f -LC phase or N f The phase is provided in an LC medium. It should also have moderate to high optical anisotropy to achieve the same electro-optic switching effect as conventional nematic LC media.

[0016] Given the wide range of applications for this type of compound with high dielectric anisotropy (Δε), there is a need for other available compounds, preferably with high-resolution bright spots and low melting points, while exhibiting a wide and suitable temperature range for ferroelectric nematic phases.

[0017] Therefore, another objective of this invention is to discover novel stable compounds suitable as components for ferroelectric nematic liquid crystal media, particularly for displays similar to conventional nematic TN, STN, IPS, FFS and TN-TFT displays.

[0018] Furthermore, the goal is to ensure the compound is thermally and photochemically stable under the primary conditions required for its application. As a mesocrystalline material, it should promote a broad mesocrystalline phase, preferably a nematic phase, especially at low temperatures below room temperature.

[0019] Surprisingly, it has been found that media containing several selected compounds described below can achieve ferroelectric phases within highly favorable temperature ranges, and that combinations of certain new compounds with conventional compounds are extremely suitable as N... f- LC dielectric components. It can be used to obtain LC dielectrics with unprecedented properties, including but not limited to those for displays requiring particularly high or even extremely high dielectric anisotropy, especially for IPS or FFS type displays, and for TN or STN displays, for electronic applications utilizing materials with high dielectric permittivity, capacitors, and liquid crystal media for electromechanical devices. The dielectrics and compounds used according to the invention are sufficiently stable and colorless. In particular, they are characterized by extremely high dielectric constants, and especially extremely high dielectric anisotropy (Δε), by which a much lower threshold voltage is required when used in optical switching components. The compound has reasonably good solubility for compounds with comparable properties and can be blended with similar compounds almost without restriction. Furthermore, the compounds used according to the invention have high-definition bright spots. These compounds also have relatively low melting points, or can be stably maintained below their melting points in supercooled melt form. The invention is capable of forming the desired N at room temperature and below room temperature. f -LC phase.

[0020] High dielectric permittivity enables excellent physical performance. High (relative) dielectric permittivity is particularly advantageous for the dielectric in capacitors because it generates high capacitance in specific electrode regions. Furthermore, this dielectric exhibits extremely low conductivity and, due to its fluid properties, is superior to conventional high-ε dielectrics. r Materials (e.g., barium titanate).

[0021] Liquid crystal media can be used in displays based on principles such as twisted cell, guest-subject effect, oriented phase deformation (DAP) or electrically controlled birefringence (ECB) effect, coplanar switching (IPS) effect or dynamic scattering effect. Attached Figure Description

[0022] Figure 1 A graph showing the dielectric properties of the mixture of Example 1 over a temperature range of -40 to 110°C is presented. T / ε was measured at 10 Hz and approximately 50 mV. r The graph shows the relative dielectric permittivity ε during cooling. r The value of ε. Between approximately 5 and 55°C, ε r The value has a maximum value (plateau shape) and decreases sharply with increasing temperature. At approximately 52°C, ε r The maximum permittivity is 42400.

[0023] Therefore, in one main aspect, the present invention relates to a liquid crystal medium comprising 15% by weight or more of one or more compounds of formula IA.

[0024]

[0025] 15% by weight or more of one or more compounds of formula IB,

[0026]

[0027] and 15% by weight, preferably 20% by weight or more of one or more compounds selected from formulas IC-1 to IC-3.

[0028]

[0029] in

[0030] X 1B It can be represented as -CN or -NCS, preferably -CN.

[0031] X 1C This indicates -CN, F, CF3, -OCF3, -NCS, SF5, or O-CF=CF2, preferably -CN or F, and most preferably CN.

[0032] Z 1A and Z 1B Each can be represented independently as -(CO)-O- or -CF2-O- or a single bond, preferably -(CO)-O- or -CF2-O-.

[0033] Z 2A and Z 2B Each can be represented independently as a single bond, -(CO)-O-, or -CF2-O-, preferably a single bond.

[0034] Z 1C and Z 2C One of the two groups represents -(CO)-O- or -CF2-O- and the other represents a single bond, preferably Z 1C It is -(CO)-O- or -CF2-O- and Z 2C It is a single key.

[0035] L 1A L 1B and L 1C They can be represented independently of each other, either H or CH3, preferably H.

[0036] L 2A It is F or H, preferably F.

[0037] L 2C It is F or H, preferably F.

[0038] A 1A express

[0039]

[0040]

[0041] Preferred

[0042]

[0043] Optimal Selection

[0044]

[0045] A 1B express

[0046]

[0047] Preferred

[0048]

[0049] Where L 8B The designation indicates an alkyl, alkoxy, or alkoxyalkyl group, each having 1 to 7 carbon atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3, or CH2CH2CH2OCH3.

[0050] A 1C Independently represent

[0051]

[0052]

[0053] Preferred

[0054]

[0055] Optimal Selection

[0056]

[0057] A 2C express

[0058]

[0059] Preferred

[0060]

[0061] m and n are 0, 1, or 2, where (m+n) is 2.

[0062] R 1A R 1B and R 1CEach of these groups independently represents an alkyl group having 1 to 12 C atoms, preferably 1 to 8, more preferably 1 to 6, and most preferably 1 to 5 C atoms, wherein, in addition, one or more CH2 groups among these groups may, in each case, be independently converted to -C≡C-, -CF2-O-, -OCF2-, -CH=CH-, -O-, -S-, -(CO)-O-, or -O-(CO)- substitution, wherein the O / S atoms are not directly connected to each other, and one or more H atoms may be substituted with halogens; or representing H,

[0063] Preferably R 1A R 1B and R 1C Independently, it is a halogenated or unsubstituted alkyl group having 1 to 10 C atoms, wherein one or more CH2 groups in these groups may be substituted with -O- or -CH=CH- in such a way that the O atom is not directly attached.

[0064] The percentage is provided on the basis of 100% by weight of the entire medium.

[0065] The various formulas IA, IB, and IC-1 to IC-3, as well as the group R in each of their sub-formulas. 1A R 1B and R 1C Preferably, it represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. These alkyl chains are preferably straight-chain, or in the form of R... 1C In this case, it is preferably branched at the 2 or 3 position by a single methyl or ethyl substituent. 1A R 1B and R 1C Particularly preferred are straight-chain alkyl groups having 1 to 7 carbon atoms or unbranched alkenyl groups having 2 to 8 carbon atoms, especially unbranched alkyl groups having 1 to 5 carbon atoms.

[0066] Alternative preferred group R 1A R 1B and R 1C It is selected from cyclopentyl, 2-fluoroethyl, cyclopropylmethyl, cyclopentylmethyl, cyclopentylmethoxy, cyclobutylmethyl, 2-methylcyclopropyl, 2-methylcyclobutyl, 2-methylbutyl, 2-ethylpentyl and 2-alkoxyethoxy.

[0067] Each contains a branched or substituted end group R 1A R 1B and R 1CCompounds of formulas IA, IB, and IC-1 to IC-3 are sometimes significant due to their good solubility in liquid crystal substrate materials. (The R group is also mentioned.) 1A R 1B and R 1C The preferred materials are straight chains.

[0068] Group R 1A R 1B and R 1C Each of the following portions is particularly preferred:

[0069] CH3

[0070] C2H5

[0071] n-C3H7

[0072] n-C4H9

[0073] n-C5H 11

[0074] C2H5CH(CH3)CH2

[0075] n-C6H 13

[0076] n-C7H 15

[0077] n-C3H7CH(C2H5)CH2

[0078] n-C8H 17

[0079] c-C3H5

[0080] c-C3H5CH2

[0081] c-C4H7

[0082] c-C5H7

[0083] c-C5H9

[0084] c-C5H9CH2

[0085] CH2=CH

[0086] CH3CH=CH

[0087] CH2=CH(CH2)2

[0088] CH3O

[0089] C2H5O

[0090] n-C3H7O

[0091] n-C4H9O

[0092] n-C5H 11 O

[0093] CH3OCH2

[0094] C2H5OCH2

[0095] CH3OCH2CH2

[0096] C2H5OCH2CH2

[0097] The following end-base abbreviations are used:

[0098] c-C3H5

[0099] c-C3H5CH2

[0100] c-C4H7

[0101] c-C5H7

[0102] c-C5H9

[0103] and

[0104] c-C5H9CH2

[0105] Another embodiment of the present invention relates to a ferroelectric nematic liquid crystal medium comprising one or more compounds selected from formulas IA, IB, IC-1, IC-2 and IC-3 as defined above.

[0106] Another embodiment of the present invention relates to a ferroelectric nematic liquid crystal medium comprising one or more compounds of formula IC-3 as defined above, preferably in the percentages and preferred formulas provided throughout the present invention.

[0107] In a preferred embodiment, the medium according to the invention preferably comprises one, two, three or more compounds of formula IA-1.

[0108]

[0109] Preferably, the compounds are selected from the group consisting of formulas IA-1 to IA-3, and preferably compounds of formula IA-1:

[0110]

[0111] Each parameter has the meaning given above, and the preferred values ​​are...

[0112] Z1A It represents -CF2-O-.

[0113] In a preferred embodiment, the medium according to the invention preferably comprises one, two, three or more compounds of formula IB-1 and / or IB-2, preferably of formula IB-1.

[0114]

[0115] R 1B This indicates an alkyl group having 1 to 12 carbon atoms, preferably 1 to 7, more preferably 1 to 6, and most preferably 1 to 5 carbon atoms, wherein, in addition, one or more CH2 groups among these groups may, in each case, be independently converted to -C≡C-, -CF2-O-, -OCF2-, -CH=CH-, The substitutions are -O-, -S-, -CO-O-, or -O-CO-, where the O / S atoms are not directly connected to each other, and one or more H atoms may be substituted with halogens; or it represents H,

[0116] Preferably, R 1B These are halogenated or unsubstituted alkyl groups having 1 to 12 carbon atoms, wherein, in addition, one or more CH2 groups in these groups may, in each case, be independently substituted with -C≡C- or -CH=CH-.

[0117] A 1B express

[0118]

[0119] Preferred

[0120]

[0121] And Z 1B Z 2B Independently represented as -(CO)-O- or -CF2-O-,

[0122] Preferably, compounds are selected from the group consisting of formulas IB-1-1 to IB-2-3:

[0123]

[0124] Each parameter has the meaning given above, and in particular, in equations IB-1-1 to IB-1-3,

[0125] Z 1B Preferably represented as -CF2-O-

[0126] And specifically, in formulas IB-2-1 and IB-2-2,

[0127] Z 2B Preferably, it represents -CF2-O-;

[0128] And specifically, in equation IB-2-3,

[0129] Z 2B Preferably, it represents -C(O)O-.

[0130] In a preferred embodiment, the medium according to the invention preferably comprises one, two, three or more compounds selected from formulas IC-1-1 to IC-3-5:

[0131]

[0132]

[0133] Where A 1C As defined above,

[0134] Preferably, compounds are selected from the group consisting of formulas IC-1-1-1 to IC-3-5-2, and more preferably from the group consisting of formulas 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.

[0135]

[0136]

[0137]

[0138] Each parameter has the meaning given above, and preferably...

[0139] L 1C H represents

[0140] Z 1C It represents -CF2-O- or -(CO)-O-, and

[0141] X 1C It can be represented as -CN or F, preferably -CN.

[0142] The most preferred compounds used in the medium are those of formulas IC-1-1 to IC-1-4, which are compounds of the following formulas:

[0143]

[0144]

[0145] The parameters are defined above, and preferably L 1C For H.

[0146] In a preferred embodiment of the invention, the medium comprises up to 100% of one or more compounds, preferably three, four, five, six or more compounds selected from Group 1, i.e., compounds of the group consisting of formulas IA, IB and IC-1 / IC-2 / IC-3. In this embodiment, the medium is preferably composed primarily of these compounds, more preferably substantially of these compounds, and most preferably almost entirely of these compounds.

[0147] For the purposes of this invention, unless otherwise specified in each case, the following definitions apply to the description of the components of the composition:

[0148] - "Contains": The concentration of the component discussed in the composition is preferably 5% or higher, particularly preferably 10% or higher, and very particularly preferably 20% or higher.

[0149] - "Mainly composed of": The concentration of the component discussed in the composition is preferably 50% or higher, particularly preferably 55% or higher, and very particularly preferably 60% or higher.

[0150] - "consisting essentially of": The concentration of the component discussed in the composition is preferably 80% or higher, particularly preferably 90% or higher, and very particularly preferably 95% or higher, and

[0151] - "consisting of almost entirely": The concentration of the component discussed in the composition is preferably 98% or higher, particularly preferably 99% or higher, and very particularly preferably 100.0%.

[0152] Preferably, the medium according to this application satisfies one or more of the following conditions. These preferably include:

[0153] -20% by weight or more of a compound of formula IA, more preferably 25% by weight, more preferably 27% by weight or more, and most preferably 32% by weight or more of a compound of formula IA,

[0154] -17% by weight or more of a compound of formula IB, more preferably 20% by weight or more, more preferably 22% by weight or more, and most preferably 25% by weight or more of a compound of formula IB,

[0155] -40% by weight or more of compounds selected from formulas IA and IB, more preferably 45% by weight, more preferably 50% by weight or more, and most preferably 55% by weight or more of compounds selected from formulas IA and IB, that is, the sum of compounds of formulas IA and IB is preferably at least one of the above values.

[0156] -20% by weight or more, preferably 25% by weight or more, more preferably 28% by weight, more preferably 32% by weight or more, and most preferably 34% by weight or more of compounds selected from formula IC-1, IC-2, and IC-3,

[0157] -Optional 2% by weight or more of a compound of formula ID (ID-1, ID-2, ID-3, ID-4), more preferably 5% by weight, more preferably 10% by weight or more, and most preferably 15% by weight or more of a compound of formula ID.

[0158] - One, two, three or more, preferably three or more compounds of formula IA-1-1, preferably compounds of formula DUUQU-nF, most preferably compounds selected from the group consisting of compounds DUUQU-2-F, DUUQU-3-F, DUUQU-4-F, DUUQU-5-F, and DUUQU-6-F.

[0159] - One, two, three or more, preferably three or more compounds of formula IB-1, preferably compounds of formula GUUQU-nN and / or DUUQU-nN, most preferably compounds selected from the group consisting of 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.

[0160] - One, two, three or more compounds of formula IA-1-3, preferably compounds of formula GUUQU-nF, more preferably compounds selected from the group consisting of compounds GUUQU-3-F, GUUQU-4-F and GUUQU-5-F.

[0161] - One, two, three or more compounds of the formula IB-1-3, preferably compounds of the formula DUUQU-nN, more preferably compounds selected from the group consisting of compounds DUUQU-3-N, DUUQU-4-N and DUUQU-5-N.

[0162] - One, two, three or more compounds of formula IC-1-1, preferably compounds of formula MUZU-nN or MUQU-nN, more preferably compounds selected from the group consisting of compounds MUZU-2-N, MUZU-3-N, MUZU-4-N and MUZU-5-N.

[0163] - One, two, three or more compounds of formula IC-3, preferably compounds selected from formula MUU-nN or UMU-nN, more preferably compounds selected from the group consisting of compounds MUU-3-N, MUU-4-N, MUU-5-F, UMU-3-N, UMU-4-N and UMU-5-N,

[0164] - One, two, three or more compounds of formula IC-1-1, preferably compounds selected from the formula GUZU-nN or GUQU-nN, more preferably compounds selected from the group consisting of compounds GUZU-3-N, GUZU-4-N, GUZU-5-F, GUQU-3-N, GUQU-4-N and GUQU-5-N.

[0165] and / or

[0166] - One, two, three or more compounds of the formula IC-1-1-3 and IC-1-1-4, preferably compounds of the formula UUZU-nN and / or UUQU-nN, most preferably compounds selected from the group consisting of compounds UUZU-2-N, UUZU-3-N, UUZU-4-N, UUZU-5-N, UUQU-2-N, UUQU-3-N and UUQU-4-N.

[0167] Where n is 1, 2, 3, 4, 5, 6 or 7.

[0168] In another preferred embodiment of the invention, the compounds of formulas IA, IB, and IC-1 / IC-2 / IC-3 are the first group of compounds, i.e., the compounds of group 1. In this embodiment, the concentration of these first group of compounds is preferably in the range of 70% or higher, preferably 80% or higher, more preferably 90% or higher to 100% or lower.

[0169] In addition to compounds of formulas IA, IB, and IC-1 / IC-2 / IC-3, the medium according to the invention optionally, preferably necessarily, contains one, two, three, or more compounds selected from formulas ID-1 to ID-4.

[0170]

[0171]

[0172] X D This indicates CN, F, CF3, -OCF3, NCS, SF5, or O-CF=CF2, preferably -CN, F, -CF3, -OCF3, -Cl, or -NCS, and most preferably F or CN.

[0173] L 1D L2D L 3D L 4D L 5D L 6D and L 7D Independently representing F, H, alkyl, alkoxy, or alkoxyalkyl, each having 1 to 7 C atoms, preferably H, F, CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3, or CH2CH2CH2OCH3.

[0174] Z 1D and Z 2D They can be independently represented as -(CO)-O-, -CF2-O-, or single bonds, and preferably both are -(CO)-O-.

[0175] R 1D This indicates an alkyl group having 1 to 12 carbon atoms, preferably 1 to 7, more preferably 1 to 6, and most preferably 1 to 5 carbon atoms, wherein, in addition, one or more CH2 groups among these groups may, in each case, be independently converted to -C≡C-, -CF2-O-, -OCF2-, -CH=CH-, -O-, -S-, -(CO)-O-, or -O-(CO)- substitution, wherein the O / S atoms are not directly connected to each other, and one or more H atoms may be substituted with halogens; or representing H,

[0176] Preferably, R 1D These are halogenated or unsubstituted alkyl groups having 1 to 12 carbon atoms, wherein, in addition, one or more CH2 groups in these groups may, in each case, be independently substituted with -C≡C- or -CH=CH-.

[0177] R 2D The designation indicates an alkyl, alkoxy, or alkoxyalkyl group, each having 1 to 7 carbon atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3, or CH2CH2CH2OCH3.

[0178] A 1D Indicates a single key,

[0179]

[0180]

[0181] Preferred single bond,

[0182]

[0183] in

[0184] L 8D The designation indicates an alkyl, alkoxy, or alkoxyalkyl group, each having 1 to 7 carbon atoms, preferably CH3, OCH3, OCH2CH3, CH2OCH3, CH2OCH2CH3, CH2CH2OCH3, CH2CH2OCH2CH3, or CH2CH2CH2OCH3.

[0185] Preferably, it includes one or more of the following:

[0186]

[0187] Among them, the variable group R 1D and L 8D As defined above.

[0188] The medium may optionally further comprise one or more compounds selected from the group consisting of:

[0189] The medium optionally, preferably necessarily, or additionally comprises compounds other than those of formulas IA, IB, and IC-1 / IC-2 / IC-3 (i.e., compounds of Group 1), namely one or more compounds selected from the group consisting of formulas II and III (Group 2), at a concentration preferably greater than 0% to 50% or less.

[0190]

[0191] in

[0192] R 2 This refers to an alkyl, alkoxy, fluorinated alkyl, or fluorinated alkoxy group having 1 to 7 carbon atoms; or an alkenyl, alkenyloxy, alkoxyalkyl, or fluorinated alkenyl group having 2 to 7 carbon atoms, preferably an alkyl or alkenyl group.

[0193]

[0194] Each time it appears, it represents independently of each other.

[0195]

[0196] Preferred

[0197]

[0198] L 21 and L 22 Representing H or F, preferably L 21 F represents

[0199] L 32 and L 33 It can be H, F, or CH3, preferably H.

[0200] X 2 The term represents a halogen, a halogenated alkyl or alkoxy group having 1 to 3 carbon atoms, or a halogenated alkenyl or alkenyloxy group having 2 or 3 carbon atoms, preferably F, Cl, -OCF3, -O-CH2CF3, -O-CH=CH2, -O-CH=CF2 or -CF3, and most preferably F, Cl, -O-CH=CF2 or -OCF3.

[0201] m represents 0, 1, 2, or 3, preferably 1 or 2, and especially preferably 2.

[0202] R 3 This refers to an alkyl, alkoxy, fluorinated alkyl, or fluorinated alkoxy group having 1 to 7 carbon atoms; or an alkenyl, alkenyloxy, alkoxyalkyl, or fluorinated alkenyl group having 2 to 7 carbon atoms, preferably an n-alkyl, cyclopropyl, cyclopentyl, or alkenyl group.

[0203]

[0204] Each time it appears, it is independent of each other.

[0205]

[0206]

[0207] Preferred

[0208]

[0209] L 31 and L 32 H or F can be represented independently of each other, preferably L. 31 F represents

[0210] X 3 The term represents halogen, alkyl or alkoxy halide having 1 to 3 carbon atoms, alkenyl or alkenyloxy halide having 2 or 3 carbon atoms, F, Cl, -OCF3, -OCHF2, -O-CH2CF3, -O-CH=CF2, -O-CH=CH2 or -CF3, most preferably F, Cl, -O-CH=CF2, -OCHF2 or -OCF3.

[0211] Z 3This indicates -CH2CH2-, -CF2CF2-, -COO-, trans-CH=CH-, trans-CF=CF-, -CH2O-, or a single bond, preferably -CH2CH2-, -COO-, trans-CH=CH-, or a single bond, and very preferably -(CO)-O-, trans-CH=CH-, or a single bond.

[0212] n represents 0, 1, 2, or 3, preferably 1, 2, or 3, and especially preferably 1.

[0213] Each ring, and preferably the phenylene ring, may optionally be substituted with one or two alkyl groups, preferably with methyl and / or ethyl groups, preferably with one methyl group, and wherein compounds of formulas IA, IB, IC-1 / IC-2 / IC-3 and ID are not included in compounds of formula II.

[0214] Optionally, alternatively, or additionally, it may comprise one or more compounds selected from the group consisting of formulas IV and V (Group 3), preferably at a concentration greater than 0% to 15%.

[0215]

[0216] in

[0217] R 41 and R 42 They independently possess the R mentioned above in Equation II. 2 The meaning indicated, preferably R 41 Indicates alkyl and R 42 Indicates alkyl or alkoxy, or R 41 Indicates alkenyl and R 42 Indicates alkyl group,

[0218]

[0219] Independently, and if

[0220] Appeared twice.

[0221] These groups are also represented independently of each other.

[0222]

[0223]

[0224] Preferred

[0225] One or more of them

[0226] express

[0227]

[0228] Z 41 and Z 42 The following groups can be represented independently of each other, and if Z 41 If these groups appear twice, they also independently represent the following groups: -CH2CH2-, -COO-, trans-CH=CH-, trans-CF=CF-, -CH2O-, -CF2-O-, -C≡C-, or a single bond, preferably one or more of which represent a single bond, and

[0229] p represents 0, 1, or 2, preferably 0 or 1, and

[0230] R 51 and R 52 They are independent of each other regarding R 41 and R 42 The meaning given is one of the following, and preferably refers to an alkyl group having 1 to 7 carbon atoms, preferably a n-alkyl group, and particularly preferably a n-alkyl group having 1 to 5 carbon atoms; an alkoxy group having 1 to 7 carbon atoms, preferably a n-alkoxy group, and particularly preferably a n-alkoxy group having 2 to 5 carbon atoms; an alkoxyalkyl group, alkenyl group, or alkenyloxy group having 2 to 7 carbon atoms, preferably 2 to 4 carbon atoms, preferably an alkenyloxy group.

[0231] to

[0232] If they exist, then each is represented independently of the others.

[0233]

[0234] Preferred

[0235]

[0236] Preferred

[0237] express

[0238] And if it exists, then

[0239] Preferred representation

[0240] Z 51 To Z 53 Each of these terms independently represents -CH2-CH2-, -CH2-O-, -CH=CH-, -C≡C-, -COO-, or a single bond, preferably -CH2-CH2-, -CH2-O-, or a single bond, and particularly preferably a single bond.

[0241] i and j each represent 0 or 1 independently.

[0242] (i+j) preferably represents 0, 1, or 2, more preferably 0 or 1, and most preferably 1.

[0243] Each of the rings, and preferably the phenylene ring, may optionally be substituted with one or two alkyl groups, preferably with methyl and / or ethyl groups, and preferably with one methyl group.

[0244] Optionally, and preferably necessarily alternatively or additionally, it comprises one or more compounds selected from Group 4, i.e., the group consisting of compounds of formulas I and VI to IX, preferably two, three or more compounds, at a concentration preferably greater than 0% to 20%.

[0245]

[0246]

[0247] in

[0248] express

[0249]

[0250]

[0251] express

[0252]

[0253] Preferred

[0254]

[0255] n represents 0 or 1,

[0256] R 11 and R 12 The terms "alkyl", "alkoxy", "fluorinated alkyl", or "fluorinated alkoxy" are independently represented, preferably having 1 to 7 carbon atoms, wherein one of the CH2 groups may be replaced by 1,2-cyclopropyl, 1,3-cyclopentyl, or 1,3-cyclopentenyl; and "alkenyl", "alkenyloxy", "alkoxyalkyl", or "fluorinated alkenyl" having 2 to 7 carbon atoms, preferably alkyl, alkoxy, alkenyl, or alkenyloxy, most preferably alkyl, alkoxy, or alkenyloxy.

[0257] R 61This refers to an unsubstituted alkyl group having 1 to 7 carbon atoms, preferably a straight-chain alkyl group, more preferably a n-alkyl group, and most preferably propyl or pentyl; an unsubstituted alkenyl group having 2 to 7 carbon atoms, preferably a straight-chain alkenyl group, and particularly preferably having 2 to 5 carbon atoms; an unsubstituted alkoxy group having 1 to 6 carbon atoms; or an unsubstituted alkenyloxy group having 2 to 6 carbon atoms.

[0258] R 62 This indicates an unsubstituted alkyl group having 1 to 7 carbon atoms, an unsubstituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted alkenyloxy group having 2 to 6 carbon atoms.

[0259] l represents 0 or 1.

[0260] R 71 This refers to an unsubstituted alkyl group having 1 to 7 carbon atoms, preferably a straight-chain alkyl group, more preferably a n-alkyl group, and most preferably propyl or pentyl; or an unsubstituted alkenyl group having 2 to 7 carbon atoms, preferably a straight-chain alkenyl group, and particularly preferably having 2 to 5 carbon atoms.

[0261] R 72 This refers to an unsubstituted alkyl group having 1 to 7 carbon atoms, preferably 2 to 5 carbon atoms; an unsubstituted alkoxy group having 1 to 6 carbon atoms, preferably 1, 2, 3, or 4 carbon atoms; or an unsubstituted alkenyloxy group having 2 to 6 carbon atoms, preferably 2, 3, or 4 carbon atoms.

[0262] express

[0263]

[0264] R 81 This refers to an unsubstituted alkyl group having 1 to 7 carbon atoms, preferably a straight-chain alkyl group, more preferably a n-alkyl group, and most preferably propyl or pentyl; or an unsubstituted alkenyl group having 2 to 7 carbon atoms, preferably a straight-chain alkenyl group, and particularly preferably having 2 to 5 carbon atoms.

[0265] R 82 This refers to an unsubstituted alkyl group having 1 to 7 carbon atoms, preferably 2 to 5 carbon atoms; an unsubstituted alkoxy group having 1 to 6 carbon atoms, preferably 1, 2, 3, or 4 carbon atoms; or an unsubstituted alkenyloxy group having 2 to 6 carbon atoms, preferably 2, 3, or 4 carbon atoms.

[0266] express

[0267]

[0268] Preferred

[0269]

[0270] More

[0271]

[0272] Z 8 It represents -(CO)-O-, -CH2-O-, -CF2-O-, or -CH2-CH2-, preferably -(CO)-O- or -CH2-O-, and

[0273] o represents 0 or 1.

[0274] R 91 and R 92 They are independent of each other and possess the characteristics mentioned above regarding R. 72 The meaning given,

[0275] R 91 Preferably, it represents an alkyl group having 2 to 5 carbon atoms, more preferably having 3 to 5 carbon atoms.

[0276] R 92 Preferably, it represents an alkyl or alkoxy group having 2 to 5 carbon atoms, more preferably an alkoxy group having 2 to 4 carbon atoms; or an alkenyloxy group having 2 to 4 carbon atoms.

[0277] express

[0278] p and q represent 0 or 1 independently, and

[0279] (p+q) preferably represents 0 or 1, if

[0280] express

[0281] Alternatively, preferably p = q = 1,

[0282] Each of the rings, and preferably the phenylene ring, may optionally be substituted with one or two alkyl groups, preferably with methyl and / or ethyl groups, and preferably with one methyl group.

[0283] And especially the ring

[0284] Alternative land economy Replacement

[0285] Furthermore, compounds of formula VII are not included in compounds of formula IX, and compounds of formula I are not included in compounds of formulas VI to IX or compounds of formula IX.

[0286] Optionally, and preferably necessarily alternatively or additionally, it comprises one or more compounds selected from Group 5, i.e., the group of compounds of formula B, preferably two, three or more compounds, the concentration of which is preferably greater than 0% to 20%.

[0287]

[0288] in

[0289] express

[0290]

[0291]

[0292] This indicates that they occur independently of each other each time they appear.

[0293]

[0294] Preferred

[0295] Optimal Selection

[0296] n represents 0, 1, or 2, preferably 1.

[0297] R 1 This indicates an alkyl group having 1 to 7 carbon atoms, wherein one or more CH2 groups in this group, preferably one CH2 group, may be independently substituted with -C≡C-, -CF2-O-, -OCF2-, -O-, -(CO)-O-, -O-(C=O)-, cyclopropylene, 1,3-cyclobutylene, 1,3-cyclopentylene, or 1,3-cyclopentenylene, preferably substituted with cyclopropylene or 1,3-cyclopentylene. Preferably, one CH2 group may be substituted with 1,2-cyclopropylene. The -CH2- group may be replaced by cyclopropyl, 1,3-cyclopentyl, or 1,3-cyclopentenyl; it may be an alkenyl, alkenyloxy, alkoxyalkyl, or fluorinated alkenyl group having 2 to 7 C atoms, preferably an alkyl or alkenyl group, wherein one of the -CH2- groups may be replaced by cyclopropyl, 1,3-cyclobutyl, 1,3-cyclopentyl, or 1,3-cyclopentenyl, preferably by cyclopropyl or 1,3-cyclopentenyl, wherein the O atoms are not directly connected to each other, and one or more of the H atoms may be replaced by a halogen.

[0298] X 1 The group represents F, Cl, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy, or fluorination, wherein the latter four groups preferably have 1 to 4 carbon atoms; more preferably, the group represents F, Cl, CF3, or OCF3, and

[0299] Each of the rings, and preferably the phenylene ring, may optionally be substituted with one or two alkyl groups, preferably with methyl and / or ethyl groups, and preferably with one methyl group.

[0300] Preferably, the medium contains one or more compounds from Group 1 and Group 2.

[0301] The corresponding starting materials can generally be readily prepared by those skilled in the art using synthetic methods known from the literature or are commercially available. The reaction methods and reagents used are, in principle, known from the literature. Other reaction conditions are exemplified through working examples. Other preferred method variations not mentioned above are disclosed through examples or claims.

[0302] In this invention, the 2,5-disubstituted dioxane ring of the following formula...

[0303]

[0304] Preferably, the dioxane ring represents the 2,5-trans configuration, i.e., the substituents R are preferably all located at the equatorial position in the preferred chair conformation. The following formula represents a 2,5-disubstituted tetrahydropyran.

[0305]

[0306] Also preferably, it represents a tetrahydropyran ring in the 2,5-trans configuration, i.e., the substituents are preferably all located at the equatorial position in the preferred chair conformation.

[0307] The liquid crystal medium according to the invention has a wide ferroelectric nematic phase temperature range. It exhibits a ferroelectric nematic phase range at 20°C and above and below 20°C (ambient temperature). It covers the range of greatest technical interest from at least 10 to 50°C and significantly extends to lower and / or higher temperatures. Therefore, it is well-suited for all kinds of domestic or industrial applications, even with some limitations outdoors. The medium exhibits a ferroelectric nematic phase at least in the temperature range of 20 Kelvin or higher, more preferably in the range of 30 K or higher, and most preferably in the range of 40 K or higher. The achievable combinations of temperature range, clearing point, low-temperature stability (LTS), (relative) dielectric permittivity, dielectric anisotropy, and optical anisotropy of the ferroelectric nematic phase of compounds containing formulas IA, IB, and IC-1 / IC-2 / IC-3 are far superior to those of prior art materials of this type. Previously, only a single compound material was available with limited choices, having a limited range of ferroelectric nematic phases.

[0308] In addition, the mixtures according to the invention generally exhibit an extremely wide range of nematic phases with a clearing point of 65°C or higher.

[0309] The liquid crystal medium according to the invention preferably exhibits a ferroelectric nematic phase temperature range of 20 degrees or higher, which preferably extends beyond a range of 40 degrees or higher, and more preferably a range of 60 degrees or higher.

[0310] Preferably, the liquid crystal medium according to the invention preferably exhibits a ferroelectric nematic phase at temperatures ranging from 10°C to 30°C, more preferably from 10°C to 40°C, even more preferably from 10°C to 50°C, even more preferably from 0°C to 50°C, and most preferably from -10°C to 50°C.

[0311] In another preferred embodiment, the liquid crystal medium according to the invention preferably exhibits a ferroelectric nematic phase from 10°C to 40°C, more preferably from 10°C to 50°C, even more preferably from 10°C to 60°C, and most preferably from 10°C to 70°C.

[0312] The liquid crystal medium according to the present invention exhibits excellent dielectric properties.

[0313] Due to its outstanding properties, this medium can play a role in many new technological fields and can be used for electro-optical purposes, such as supercapacitors, nonlinear optical components, electric field sensors, storage devices, and electromechanical devices including generators (i.e., energy harvesting devices) and actuators. The material can, for example, enable unconventional modes of energy harvesting from vibrational motion.

[0314] Preferably, the ε of the medium according to the present invention r The value (at 20°C and 10Hz) is 700 or greater, more preferably 800 or greater, more preferably 15000, even more preferably 30000 or greater and more preferably 35000 or greater.

[0315] These dielectric properties are achieved at temperatures that allow the dielectric to be in a ferroelectric nematic phase. The dielectric characteristics can exhibit hysteresis behavior, especially at varying temperatures, and in this case, the value obtained at a given temperature can depend on the material's history, i.e., whether the material has undergone heating or cooling.

[0316] This effect, in particular, enables the device to operate, for example, in a bistable mode, which can be advantageously used in electro-optic devices, such as those known from ferroelectric smectic devices.

[0317] The liquid crystal medium according to the invention preferably contains 2 to 40, particularly preferably 4 to 20, compounds as other components besides one or more compounds according to the invention. Specifically, these media may contain 1 to 25 components besides one or more compounds according to the invention. These other components are preferably selected from ferroelectric nematic or nematic (univariant or isotropic) materials.

[0318] The prior art ferroelectric materials and similar compounds having high dielectric capacitance supplied for combination with the materials of the present invention are selected from, for example, the following structures:

[0319]

[0320] The medium according to the invention preferably contains 1% to 100%, more preferably 10% to 100%, and especially preferably 50% to 100% of compounds of formula IA and / or IB and / or IC-1 / IC-2 / IC-3 preferred for use according to the invention.

[0321] The present invention also relates to a method for preparing a liquid crystal medium as described herein, wherein at least 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 of formula IC-1 / IC-2 / IC-3 are combined and mixed with each other and with any other optional components or additives. The resulting mixture is equal to 100% by weight.

[0322] The liquid crystal mixtures according to the invention are prepared in a conventional manner. Generally, the required amount of the component used in a small quantity is dissolved in the component constituting the main component, preferably dissolved at a high temperature. The component can also be mixed in an organic solvent, such as a solution in acetone, chloroform, or methanol, and after thorough mixing, the solvent is removed, for example, by distillation. In addition, the mixtures can be prepared by other conventional methods, such as by using premixes, such as homologue mixtures, or using a so-called "multi-bottle" system.

[0323] The liquid crystal mixture may also contain other additives known to those skilled in the art and described in the literature. For example, 0 to 15%, preferably 0 to 10%, of multicolor dyes, chiral dopants, stabilizers, or nanoparticles may be added. The individual compounds added are used at a concentration of 0.01 to 6%, preferably 0.1 to 3%. However, the concentration data for other components of the liquid crystal mixture (i.e., liquid crystals or mesocrystalline compounds) are given here without considering the concentrations of these additives.

[0324] The liquid crystal mixtures according to the present invention can significantly broaden the range of available parameters.

[0325] The present invention also relates to electro-optic displays containing such media (especially TFT displays having two plane-parallel outer plates forming a cell together with a frame, an integrated nonlinear component on the outer plates for switching individual pixels, and a ferroelectric nematic liquid crystal material having positive dielectric anisotropy and high resistivity located in the cell), and the use of such media for electro-optic purposes.

[0326] The term "alkyl" encompasses unbranched and branched alkyl groups having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, particularly and preferably unbranched groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, and n-heptyl, and alternatively, groups substituted with one methyl, ethyl, or propyl group such as n-butyl, n-pentyl, n-hexyl, and n-heptyl. Groups having 1 to 5 carbon atoms are generally preferred.

[0327] The term "alkenyl" encompasses both unbranched and branched alkenyl groups having up to 12 carbon atoms, with unbranched groups being particularly preferred. Especially preferred alkenyl groups are C2-C7-1E-alkenyl, C4-C7-3E-alkenyl, C5-C7-4-alkenyl, C6-C7-5-alkenyl, and C7-6-alkenyl, particularly 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, and similar groups. Groups having 2 to 5 carbon atoms are generally preferred.

[0328] The term "halogenated alkyl" preferably encompasses mono- or polyfluorinated and / or chlorinated groups. Perhalogenated groups are included. Fluorinated alkyl groups are particularly preferred, especially CF3, CH2CF3, CH2CHF2, CHF2, CH2F, CHFCF3, and CF2CHFCF3. The term "halogenated alkenyl" and related expressions are explained accordingly.

[0329] The matrix display constructed according to the invention, consisting of a polarizer, an electrode substrate, and surface-treated electrodes, corresponds to a common design for such displays. The term "common design" is used broadly herein and also encompasses all derivatives and variations of matrix displays, particularly matrix display assemblies based on polycrystalline silicon TFTs.

[0330] However, the fundamental difference between the display according to the present invention and conventional twisted nematic cell-based displays to date lies in the selection of liquid crystal parameters of the liquid crystal layer.

[0331] The following embodiments illustrate the invention but are not intended to limit it. Those skilled in the art will be able to discover working details not given in detail in the general description from the embodiments, and summarize them based on general expert knowledge and apply them to specific problems.

[0332] In the foregoing and hereinafter, percentage data are expressed as weight percentages. Unless otherwise expressly indicated, all temperature values ​​indicated in this application, such as melting point T(C,N), phase transition from smectic (Sm) to nematic (N) T(S,N), and clearing point T(N,I) or T(N), are not expressed as weight percentages. f All values ​​(C, I) are indicated in degrees Celsius (°C), and all temperature differences are indicated accordingly in different degrees (° or degrees). Furthermore, C = crystalline state, N = nematic phase, Nf = ferroelectric nematic phase, Sm = smectic phase (especially SmA, SmB, etc.), Tg = glass transition temperature, and I = isotropic phase. The data between these symbols represent the transition temperature. Δn represents optical anisotropy (589 nm, 20 °C), and Δε represents dielectric anisotropy (1 kHz, 20 °C).

[0333] Physical, physicochemical, and electro-optical parameters are determined by generally known methods, such as the handbook "MerckLiquid Crystals- -Physical Properties of Liquid Crystals -Description of the Measurement Methods", 1998, Merck KGaA, Darmstadt.

[0334] The presence of the ferroelectric nematic phase in a material is identified using differential scanning calorimetry (DSC) by observing the texture under a polarizing microscope equipped with a hot stage for controlled cooling or heating, and further confirmed by measuring the temperature dependence of the dielectric properties. The transition temperature is primarily determined by probing the optical behavior under a polarizing microscope.

[0335] The dielectric anisotropy Δε of each substance was measured at 20 °C and 1 kHz. For this purpose, 5 to 10 wt% of the substance under study dissolved in the dielectric positive mixture ZLI-4792 (Merck KGaA) was measured, and the measurements were extrapolated to 100% concentration. The optical anisotropy Δn was determined by linear extrapolation at 20 °C and a wavelength of 589.3 nm.

[0336] The relative dielectric permittivity (ε) of materials, especially those exhibiting ferroelectric nematic phases. rThe capacitance was directly determined by measuring the capacitance of at least one test cell containing the compound, having a cell thickness of 250 μm, and being vertically aligned and aligned along the surface. Temperature was controlled by a Novocontrol Novocool system set to apply temperature gradients of + / -1 K / min; + / -2 K / min; + / -5 K / min; + / -10 K / min to the sample cell. Capacitance was measured using a Novocontrol alpha-N analyzer at a frequency of 1 kHz or 10 Hz, with typical voltages <50 mV and as low as 0.1 mV to ensure they were below the threshold of the compound under study. Measurements were performed during sample heating and cooling.

[0337] In this application, unless otherwise expressly indicated, the plural form of a term refers to both the singular and plural forms, and vice versa. According to this specification, other combinations of embodiments and variations of the invention also arise from the appended claims or from combinations of several of these claims. Example

[0338] The present invention is described in detail through the following non-limiting embodiments.

[0339] compound

[0340] Example

[0341] Compound Example 1: Synthesis of UUQU-4-N

[0342]

[0343] Step 1.1

[0344]

[0345] 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(pinacol)boron were added. The mixture was heated under reflux overnight. After conventional treatment, 12.4 g (80%) of 2 was obtained as pale yellow crystals.

[0346] Step 1.2

[0347]

[0348] Dissolve 5.4 g (23 mmol) of potassium phosphate in 10 ml of water. Add 80 ml of toluene, 2.8 g (11.4 mmol) of 1-bromo-2,6-difluoro-4-butylbenzene, 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), and heat the mixture under reflux overnight. After conventional treatment, 3.42 g (62%) of 3(UUQU-4-N) as colorless crystals is obtained.

[0349] 1 ¹H NMR (400MHz, chloroform-d) δ 7.16 (d, J = 11.0 Hz, 2H), 7.07–6.99 (m, 2H), 6.91–6.81 (m, 2H), 2.69–2.61 (m, 2H), 1.69

[0350] -1.57(m,2H),1.39(h,J=7.4Hz,2H),0.96(t,J=7.3Hz,3H).

[0351] Melting point: 44℃

[0352] Single-variant ferroelectric nematic under cooling: 21°C and below

[0353] Data extrapolated from a 10% solution in ZLI-4792:

[0354] Δn(20°C)=0.120 and Δε(20°C)=54.6.

[0355] Compound Example 2: Synthesis of UUZU-4-N

[0356]

[0357] Step 2.1

[0358]

[0359] 57.2 g (150 mmol) disodium tetraborate decahydrate, 2.8 g (4 mmol) palladium chloride, 0.2 g (4 mmol) hydrazine hydroxide, 39.4 g (0.2 mol) 1-bromo-3,5-difluorobenzene, 42.8 g (0.2 mol) 5, and 200 ml of water were combined. The mixture was heated to reflux and maintained for 6 hours. After conventional treatment, 50 g (88%) of 6 was obtained.

[0360] Step 2.2

[0361]

[0362] 50 g (175 mmol) of 6 was dissolved in 300 ml of tetrahydrofuran and cooled to -75 °C. At -70 °C, 118 ml (193 mmol) of 15% n-butyllithium in hexane was added dropwise, and the mixture was stirred at this temperature for 1.5 hours. The mixture was poured over 500 g of solid carbon dioxide and allowed to warm to room temperature. After conventional treatment, 46.8 g (82%) of 7 was obtained as colorless crystals.

[0363] Step 2.3

[0364]

[0365] 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. A solution of 11.3 g (55 mmol) of N,N-dicyclohexylcarbodiimide in 50 mL of dichloromethane was added dropwise between 0 and 5 °C. The mixture was then heated to room temperature and stirred overnight. 1.4 g of oxalic acid was added, and all substances were stirred for another 1.5 hours. After standard treatment, 20.5 g (88%) of 8(UUZU-4-N) was obtained.

[0366] 1 ¹H NMR (500MHz, chloroform-d) δ 7.23–7.17 (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 = 7.4 Hz, 2H), 0.96 (t, J = 7.4 Hz, 3H).

[0367] Phase: C 69N f / N 93I.

[0368] Extrapolated from a 10% solution in ZLI-4792: Δn(20℃) = 0.159 and Δε(20℃) = 70.3.

[0369] The embodiments of the present invention and other combinations of the variations thereof are also disclosed in the claims.

[0370] Without further detailed description, it is believed that those skilled in the art can utilize the invention to its fullest extent using the foregoing description. Therefore, the foregoing preferred embodiments should be interpreted as illustrative only and in no way limit the remainder of the invention. The foregoing embodiments can be similarly and successfully replicated by replacing the reactants and / or operating conditions used in the foregoing embodiments with those generally or specifically described in the invention.

[0371] Based on the foregoing description, those skilled in the art can readily determine the basic features of the present invention, and various changes and modifications can be made to the present invention to adapt it to various uses and conditions without departing from the spirit and scope of the present invention.

[0372] This applies to a medium being a composition having its components, which may be a group of compounds and individual compounds, and it applies to a group of compounds having its individual components (i.e., compounds). The term includes, only with respect to the concentration of the individual compounds relative to the medium as a whole, the meaning that the concentration of one or more compounds under discussion is preferably 1% or higher, particularly preferably 2% or higher, and very particularly preferably 4% or higher.

[0373] In this invention, "≤" means less than or equal to, preferably less than, and "≥" means greater than or equal to, preferably greater than.

[0374] For the present invention,

[0375]

[0376] This indicates the trans-1,4-cyclohexyl group.

[0377]

[0378] This indicates a mixture of cis-1,4-cyclohexylene and trans-1,4-cyclohexylene, and

[0379]

[0380] It represents 1,4-phenylene.

[0381] For the purposes of this invention, the term "dielectrically positive compound" refers to a compound having Δε > 1.5, the term "dielectrically neutral compound" refers to a compound having -1.5 ≤ Δε ≤ 1.5, and the term "dielectrically negative compound" refers to a compound having Δε < -1.5. Here, the dielectric anisotropy of the compound is determined by dissolving 10% of the compound in a liquid crystal matrix and, in each case, measuring the capacitance of the resulting mixture in at least one test cell with a cell thickness of 20 μm and a vertical and uniform surface alignment at 1 kHz. The measurement voltage is typically 0.5 V to 1.0 V, but always below the capacitance threshold of the individual liquid crystal mixtures (materials) studied.

[0382] The host mixtures for the dielectric positive and dielectric neutral compounds were ZLI-4792, and the host mixture for the dielectric negative compounds was ZLI-2857, both sourced from Merck KGaA, Germany. The values ​​for each compound under study were obtained by extrapolating the change in dielectric constant of the host mixture after adding the compound under study to 100% of the total compound used. The compound under study was dissolved in the host mixture at 10%. If the solubility of a substance was too low for this purpose, the concentration was halved in the steps until the study could be carried out at the desired temperature.

[0383] If necessary, the liquid crystal medium according to the invention may also contain other additives, such as stabilizers in commonly used amounts. The amount of these additives used, based on the total amount of the mixture, is preferably 0% or more to 10% or less, particularly preferably 0.1% or more to 6% or less. The concentration of each compound used is preferably 0.1% or more to 3% or less. The concentrations of these and similar additives are generally not considered when specifying the concentrations and concentration ranges of the liquid crystal compounds in the liquid crystal medium.

[0384] For the purposes of this invention, unless otherwise expressly stated, all concentrations are indicated as a weight percentage, and unless otherwise expressly stated, all concentrations relate to the corresponding mixture or mixture components (again, as a whole). In this context, the term "mixture" describes the liquid crystal medium.

[0385] Unless otherwise explicitly instructed, use the following symbols:

[0386] T(N,I) or T(N) f (I) (or clp.) Clear the light [°C],

[0387] Dielectric properties at 1 kHz and preferably at 20 °C, or at various specified temperatures:

[0388] ε ┴ Dielectric polarizability perpendicular to the director.

[0389] ε || Dielectric polarizability parallel to the director,

[0390] Δε dielectric anisotropy, and screening data, especially for single compounds.

[0391] Furthermore, particularly regarding the data obtained from screening individual compounds in the nematic host mixture ZLI-4792:

[0392] n e Unusual refractive index measured at 20°C and 589 nm

[0393] n oOrdinary refractive index measured at 20℃ and 589nm and

[0394] Optical anisotropy of Δn measured at 20℃ and 589nm.

[0395] The following examples illustrate the invention, but are not intended to limit it. However, they demonstrate to those skilled in the art the concept of preferred mixtures utilizing preferably employed compounds, their respective concentrations, and combinations thereof. Furthermore, the examples illustrate the achievable properties and combinations thereof.

[0396] Structural elements are defined using abbreviations of the initial letters used for each compound:

[0397] Table A: Ring Elements

[0398]

[0399]

[0400]

[0401] Table B: Bridged Elements

[0402]

[0403] Table C: End bases

[0404]

[0405]

[0406] Where n and m are integers, and the three dots “…” are placeholders for other abbreviations in this table.

[0407] In addition to compounds of formulas IA, IB and IC-1 / IC-2 / IC-3, the mixtures according to the invention preferably contain one or more of the compounds mentioned below.

[0408] The following abbreviations are used: (n, m, k, and l are each independent integers, preferably 1 to 9, more preferably 1 to 7; k and l may also be 0 and are preferably 0 to 4, more preferably 0 or 2, and most preferably 2; n is preferably 1, 2, 3, 4, or 5, and 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, and in the combination "-Om", it is preferably 1, 2, 3, or 4, more preferably 2 or 4. The combination "-lVm" is preferably "2V1".)

[0409] For the purposes of this invention and in the following embodiments, the structure of the liquid crystal compound is indicated by acronym and the chemical formulas are converted according to Tables A to C above. All 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 All are straight-chain alkyl or alkylene groups, each having n, m, and l C atoms. Preferably, n, m, and l are independently 1, 2, 3, 4, 5, 6, or 7. Table A shows the coding of the ring elements of the compound core, Table B lists the bridging units, and Table C lists the symbols of the left and right end groups of the molecule. Acronyms consist of the following: the coding of the ring element with an optional linking group, followed by a first hyphen and the coding of the left end group, and a second hyphen and the coding of the right end group. Table D shows the illustrative structure of the compound and its various abbreviations.

[0410] Table D

[0411] Exemplary preferred compounds of formula IA

[0412]

[0413]

[0414] Exemplary preferred compounds of formula IB

[0415]

[0416] Exemplary preferred compounds of formula IC-1

[0417]

[0418]

[0419] Exemplary preferred compounds of formula IC-3

[0420]

[0421]

[0422] Other compounds used optionally

[0423]

[0424]

[0425]

[0426]

[0427] Examples of mixtures are disclosed below.

[0428] Mixture Example 1

[0429] The following mixture (M-1) was prepared and studied.

[0430]

[0431]

[0432] c The value during cooling. Mixture Example 2

[0433] The following mixture (M-2) was prepared and studied.

[0434]

[0435]

[0436] c The value during cooling.

[0437] Mixture Example 3

[0438] The following mixture (M-3) was prepared and studied.

[0439]

[0440] c The value during cooling.

[0441] These are the relative dielectric permittivity ε of any physical substance known to the author to date. r The highest value.

[0442] Mixture Example 4

[0443] The following mixture (M-4) was prepared and studied.

[0444]

[0445] c The value during cooling. Mixture Example 5

[0446] The following mixture (M-5) was prepared and studied.

[0447]

[0448]

[0449] c The value during cooling. Mixture Example 6

[0450] The following mixture (M-6) was prepared and studied.

[0451]

[0452] c) Value during cooling Mixture Example 6

[0453] The following mixture (M-6) was prepared and studied.

[0454]

[0455] c The value during cooling. Mixture Example 7

[0456] The following mixture (M-7) was prepared and studied.

[0457]

[0458]

[0459] Note: tbd: to be determined.

[0460] c The value during cooling. Mixture Example 8

[0461] The following mixture (M-8) was prepared and studied.

[0462]

[0463]

[0464] Note: tbd: to be determined.

[0465] c The value during cooling. Mixture Example 9

[0466] The following mixture (M-9) was prepared and studied.

[0467]

[0468] Note: tbd: to be determined.

[0469] c The value during cooling. Mixture Example 10

[0470] The following mixture (M-10) was prepared and studied.

[0471]

[0472] Mixture Example 11

[0473] The following mixture (M-11) was prepared and studied.

[0474]

[0475]

[0476] c) Value during cooling Mixture Example 12

[0477] The following mixture (M-12) was prepared and studied.

[0478]

[0479] c) Value during cooling Mixture Example 13

[0480] The following mixture (M-13) was prepared and studied.

[0481]

[0482] c The value during cooling. Mixture Example 14

[0483] The following mixture (M-14) was prepared and studied.

[0484]

[0485]

[0486] c The value during cooling.

[0487] Device Example 1

[0488] A 110 μm dielectric layer composed of the dielectric of Mixture Example 1 was filled into a capacitor containing two glass substrates with ITO electrodes. The capacitance of 1.41 μF was measured using a 10 Hz AC voltage. The relative dielectric permittivity (ε) of the resulting dielectric was determined. r The value is 4.2 × 10 4 .

Claims

1. A liquid crystal medium comprising 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 formulas IC-1, IC-2, and IC-3-1 to IC-3-5, in X 1B Indicates -CN or -NCS, X 1C This indicates -CN, F, CF3, -OCF3, -NCS, SF5, or O-CF=CF2. Z 1A and Z 1B Each can be represented independently as -(CO)-O- or -CF2-O- or a single bond. Z 2A and Z 2B They can be used independently to represent single bonds, -(CO)-O-, or -CF2-O-. Z 1C and Z 2C One of the two groups represents -(CO)-O- or -CF2-O- and the other represents a single bond. L 1A L 1B and L 1C They can be represented independently as H or CH3. L 2A For F or H, L 2C For F or H, Where L 8B Indicates alkyl, alkoxy, or alkoxyalkyl, each having 1 to 7 carbon atoms. R 1A R 1B and R 1C Each group independently represents an alkyl group having 1 to 12 carbon atoms, wherein one or more CH2 groups among these groups may, in each case, be independently derived from -C≡C-, -CF2-O-, -OCF2-, -CH=CH-, , , , , The substitutions are -O-, -S-, -(CO)-O-, or -O-(CO)-, where the O / S atoms are not directly connected to each other, and one or more H atoms may be substituted with halogens; or it represents H, The concentrations of compounds of formulas IA, IB, IC-1, IC-2 and IC-3-1 to IC-3-5 are in the range of 80% by weight or higher to 100% by weight or lower.

2. The liquid crystal medium according to claim 1, wherein X 1C It indicates -CN or F.

3. The liquid crystal medium according to claim 1, which exhibits a ferroelectric nematic phase.

4. The liquid crystal medium according to any one of claims 1 to 3, exhibiting a relative dielectric permittivity ε of 700 or higher at 20°C and 1 kHz. r .

5. The liquid crystal medium according to any one of claims 1 to 3, comprising one, two, three or more compounds selected from formulas IC-1-3 to IC-2-1: .

6. The liquid crystal medium according to any one of claims 1 to 3, comprising one, two, three or more compounds selected from formulas ID-1 to ID-4, in X D This indicates CN, F, CF3, -OCF3, NCS, SF5, or O-CF=CF2. L 1D L 2D L 3D L 4D L 5D L 6D and L 7D Independently representing F, H, alkyl, alkoxy, or alkoxyalkyl, each having 1 to 7 carbon atoms. Z 1D and Z 2D They can be represented independently as -(CO)-O-, -CF2-O-, and single bonds. R 1D This indicates an alkyl group having 1 to 12 carbon atoms, wherein one or more CH2 groups among these groups may, in each case, be independently converted to -C≡C-, -CF2-O-, -OCF2-, -CH=CH-, ... , , , , The substitutions are -O-, -S-, -(CO)-O-, or -O-(CO)-, where the O / S atoms are not directly connected to each other, and one or more H atoms may be substituted with halogens; or it represents H, R 2D Indicates alkyl, alkoxy, or alkoxyalkyl, each having 1 to 7 carbon atoms. in L 8D It indicates alkyl, alkoxy, or alkoxyalkyl, each having 1 to 7 carbon atoms.

7. The medium according to any one of claims 1 to 3, which exhibits a ferroelectric nematic phase at a temperature of at least 10°C to 30°C.

8. The dielectric according to any one of claims 1 to 3, which exhibits hysteresis of its dielectric properties at varying temperatures.

9. The medium according to any one of claims 1 to 3, which exhibits a ferroelectric nematic phase in a temperature range of at least 20 Kelvin.

10. Use of the liquid crystal medium according to any one of claims 1 to 9, for electro-optical purposes, for supercapacitors, and for electromechanical devices including generators and actuators.

11. Use of the liquid crystal medium according to any one of claims 1 to 9, wherein it is used in a supercapacitor.

12. Use of the liquid crystal medium according to any one of claims 1 to 9, for use in nonlinear optical components, sensors, or storage devices.

13. An electro-optic liquid crystal display comprising a liquid crystal medium according to any one of claims 1 to 9.

14. A method for preparing a liquid crystal medium according to any one of claims 1 to 9, wherein at least one or more compounds of formula IA, one or more compounds of formula IB, and one or more compounds selected from formulas IC-1, IC-2, and IC-3-1 to IC-3-5 are combined and mixed with each other and with any other component or additive.

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