TW201923043A - Liquid crystal medium and liquid crystal device - Google Patents

Abstract

The invention relates to a compound of formula I, R11-A11-(Z11-A12)p-X11-Sp11-X12-(A13-Z13)q-A14-R12 I wherein R11, R12, A11 to A14, Z11, Z13, X11, X12, Sp11, p and q have one of the meanings as given herein below. The invention further relates to method of production of a compound of formula I, to the use of said compounds in LC media and to LC media comprising one or more compounds of formula I. Further, the invention relates to a method of production of such LC media, to the use of such media in LC devices, in particular, in flexoelectric LC devices and to a flexoelectric LC device comprising a LC medium according to the present invention.

Description

Liquid crystal medium and liquid crystal device

The invention relates to a compound of formula I,
R ¹¹ -A ^11- (Z ¹¹ -A ¹² ) _p -X ¹¹ -Sp ¹¹ -X ^12- (A ¹³ -Z ¹³ ) _q -A ¹⁴ -R ¹² I
Wherein R ¹¹ , R ¹² , A ¹¹ to A ¹⁴ , Z ¹¹ , Z ¹³ , X ¹¹ , X ¹² , Sp ¹¹ , p and q have one of the meanings given below. The invention further relates to a method for preparing compounds of formula I, their use in LC media and LC media comprising one or more compounds of formula I. In addition, the present invention relates to a method for preparing such an LC medium, the use of such a medium in an LC device, especially in a flex electric LC device, and a flex electric LC device including the LC medium according to the invention.

The flexure effect is described by, for example, Chandrasekhar, "Liquid Crystals", 2nd edition, Cambridge University Press (1992) and P.G. deGennes et al., "The Physics of Liquid Crystals", 2nd edition, Oxford Science Publications (1995).

Flexural electrical devices using flexural electrical effects such as ULH devices and liquid crystal media particularly suitable for flexural electrical devices are from EP 0 971 016, GB 2 356 629 and Coles, HJ, Musgrave, B., Coles, MJ and Willmott, J., J. Mater. Chem., 11, pp. 2709-2716 (2001).

Uniform Lying Helix (ULH) has the potential as a fast switching LCD display mode. It can achieve sub-millisecond switching at 35 ° C and has an inherently high aperture ratio, bringing an energy-efficient display mode.

The materials commonly used in media suitable for ULH mode are usually dual mesogens. Due to the size and polar groups of these materials, such as the presence of terminal cyano groups, they typically have high rotational viscosity (γ ₁ ) on the order of thousands of mPa.s at 35 ° C. At elevated temperatures, such as 35 ° C, a higher γ ₁ value will not cause problems because the switching speed is directly proportional to γ ₁ . On the other hand, the value of γ1 is also proportional to the square of the pitch. Because the pitch of the palm is usually about 300 nm, this means that the switching speed is still extremely fast, about 1 millisecond or several milliseconds.

However, at the lower temperatures at which ULH devices typically operate, such as room temperature, the value of γ ₁ increases exponentially and the switching speed increases beyond favorable levels even in the case of shorter pitch materials.

In order to maintain fast switching speeds at temperatures below 35 ° C, the γ ₁ value of the LC mixture needs to be reduced, and therefore it is necessary to identify mixture components with lower γ ₁ .

Accordingly, there is a great need for new dual mesogen compounds that exhibit a favorable low γ ₁ value while also exhibiting better:
· Favorable e / K (V ^-1 ) values,
· Favorable wide nematic phase range and · High clarification point.

In addition to these requirements, the corresponding LC medium should exhibit a favorable low γ ₁ value while also exhibiting better:
· Low melting point,
· High clarification points,
· Wide palmar nematic phase range,
· Short temperature independent pitch length,
· High deflection coefficient and · Favorable low temperature stability without cell and crystallization effects in the body.

Other objects of the present invention will be immediately apparent to those skilled in the art from the following detailed description.

Unexpectedly, the present inventors have found that one or more of the above-mentioned objects can be achieved by providing a compound such as the technical scheme 1.

The invention relates to a compound of formula I,
R ¹¹ -A ¹¹ (-Z ¹¹ -A ^12- ) _p -X ¹¹ -Sp ¹¹ -X ^12- (A ¹³ -Z ^12- ) _q A ¹⁴ -R ¹² I
among them
R ¹¹ means NO ₂ , NCO or NCS
R ¹² represents F, Cl, CN, NO ₂ , NCO, NCS or a linear or branched alkyl group, which may be unsubstituted, mono- or poly-substituted with halogen or CN and wherein one or more non-adjacent and non-terminal CH ₂ groups may independently be replaced by the following groups to each other in each occurrence: -O -, - S -, - NH -, - N (CH 3) -, - CO-, -COO-, -OCO-, -O-CO-O-, -S-CO-, -CO-S-, -CH = CH-, -CH = CF-, -CF = CF- or- C≡C-, the substitution method is such that the oxygen atoms are not directly connected to each other,
Preferred are F, Cl, CN, NO ₂ , NCO, NCS, straight or branched chain alkyl, alkenyl or alkoxy which may be unsubstituted, mono- or poly-substituted with halogen or CN,
More preferably NO ₂ , NCO, NCS,
A ¹¹ to A ¹⁴ each independently represent 1,4-phenylene, and one or more CH groups may be replaced by N; trans-1,4-cyclohexyl, and one or Two non-adjacent CH ₂ groups can be replaced by O and / or S; 1,4-cyclohexyl; naphthalene-2,6-diyl; decahydronaphthalene-2,6-diyl; 1,2, 3,4-tetrahydro-naphthalene-2,6-diyl, all such groups may be unsubstituted, mono-substituted with F, Cl, CN or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl , Di-, tri- or tetra-substituted, in which one or more H atoms may be substituted by F or Cl,
Preferably each occurrence is independently 1,4-phenylene, and one or more of the CH groups may be replaced by N; or trans-1,4-cyclohexyl, and one or two of them Non-adjacent CH ₂ groups can be replaced by O and / or S. Both ring groups may be unsubstituted, F, Cl, CN or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl mono Substituted, disubstituted, trisubstituted or tetrasubstituted, in which one or more H atoms may be substituted by F or Cl,
Z ¹¹ and Z ¹² are each independently a single bond, -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -OCF ₂ -,- CF ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO- CH = CH- or -C≡C-, these groups are optionally substituted by one or more F, S and / or Si,
-COO-, -OCO-, -OCF _2- , -CF ₂ O- or a single bond is preferred,
More preferably a single key,
p and q are each independently 0, 1, 2, 3, or 4, preferably 0, 1, 2, or 3, and most preferably 1 or 2.
Sp ¹¹ is a spacer group that contains 1, 3, or 5 to 40 C atoms. One or more non-adjacent and non-terminal CH ₂ groups can also be replaced by the following groups: -O-, -S- , -NH-, -N (CH ₃ )-, -CO-, -O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-, -CF ₂ -, -CF ₂ O-, -OCF _2- , -C (OH)-, -CH (alkyl)-, -CH (alkenyl)-, -CH (alkoxy)-, -CH (oxa Alkyl)-, -CH = CH- or -C≡C-, but the substitution is such that no two O atoms are adjacent to each other and no two are selected from -O-CO-, -S-CO-, -O -COO-, -CO-S-, -CO-O- and -CH = CH- are adjacent to each other,
Preferably-(CH ₂ ) _n- , where n is 1, 3 or an integer from 5 to 15, more preferably 3 to 11, most preferably an odd integer (ie 3, 5, 7, 9 or 11) ,
X ¹¹ and X ¹² are independently selected from a single bond, -CO-O-, -O-CO-, -O-COO-, -O-, -CH = CH-, -C≡C-, -CF ₂ -O-, -O-CF _2- , -CF ₂ -CF _2- , -CH ₂ -O-, -O-CH _2- , -CO-S-, -S-CO-, -CS-S- , -S-CS-, -S-CSS-, and -S-, in -X ¹¹ -Sp ¹ -X ^12- , two O atoms, two -CH = CH- groups, and two selected from The groups of -O-CO-, -S-CO-, -O-COO-, -CO-S-, and -CO-O- are not directly connected to each other,
-CO-O-, -O-CO-, -O-, -C≡C-, -CF ₂ -O-, -O-CF ₂ -or a single bond,
More preferably, it is -CO-O-, -O-CO-, or a single bond.

Terms and definitions

The terms "liquid crystal", "mesogenic compound" or "mesogen" (also referred to as "mesogen") mean that the mesogenic phase (nematic, smectic, etc.) can be used under suitable temperature, pressure and concentration conditions. ) Or compounds which exist especially in the LC phase. Non-amphiphilic mesogens include, for example, one or more rod-shaped, banana-shaped, or disc-shaped mesogens.

The term "mesogen" means a group having the ability to induce liquid crystal (LC) phase characteristics in this context. The compound containing the mesogen group itself need not exhibit an LC phase. It is also possible that it exhibits LC phase characteristics only in mixtures with other compounds. For the sake of brevity, the term "liquid crystal" is used hereinafter for both liquid crystal raw materials and LC materials.

Throughout this application, unless explicitly stated otherwise, the term "aryl and heteroaryl" encompasses groups, which may be monocyclic or polycyclic, that is, they may have one ring (such as phenyl) Or two or more rings, which may also be fused (such as naphthyl) or covalently linked (such as biphenyl) or contain fused and linked rings.

Heteroaryl contains one or more heteroatoms preferably selected from O, N, S and Se. Especially preferred are monocyclic, bicyclic or tricyclic aryl groups having 6 to 25 C atoms and monocyclic, bicyclic or tricyclic heteroaryl groups having 2 to 25 C atoms, which optionally contain a fused ring and Replaced as appropriate. In addition, a 5-membered, 6-membered or 7-membered aryl group and a heteroaryl group are preferred. In addition, one or more CH groups may pass through N, S or O substitution. Preferred aryl groups are, for example, phenyl, biphenyl, bitriphenyl, [1,1 ': 3', 1 ''] bitriphenyl-2'-yl, naphthyl, anthracene, binaphthyl, phenanthrene, fluorene , Dihydropyrene, pyrene, pyrene, tetracene, pentacene, benzofluorene, pyrene, indene, indenofluorene, spirobifluorene, more preferably 1,4-phenylene, 4,4'-phenylene Biphenyl, 1,4-triphenylene.

Preferred heteroaryl groups are, for example, 5-membered rings such as pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, furan, thiophene, selenophene, oxazole, Isoxazole, 1,2-thiazole, 1,3-thiazole, 1, 2,3-oxadiazole, 1, 2, 4-oxadiazole, 1, 2, 5-oxadiazole, 1, 3, 4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole; 6-membered ring, Such as pyridine, pyridazine, pyrimidine, pyrazine, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, 1,2,4,5-tetrazine, 1 , 2,3,4-tetrazine, 1,2,3,5-tetrazine; or fused groups such as indole, isoindole, indazine, indazole, benzimidazole, benzotriazole , Purine, naphthalimidazole, fimidazole, pyrimidazole, pyrazine imidazole, quinazoline imidazole, benzoxazole, naphthoxazole, anthraxazole, phenanthrazole, isoxazole, benzothiazole, benzene Benzofuran, isobenzofuran, dibenzofuran, quinoline, isoquinoline, pyridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8- Quinoline, benzoisoquinoline, acridine, phenothiazine, phenoxazine, benzopyrazine, benzopyrimidine, quinoxaline, phenazine, naphthyridine, azacarbazole , Benzocarboline, phenanthroline, morpholine, thieno [2,3b] thiophene, thieno [3,2b] thiophene, dithienothiophene, isobenzothiophene, dibenzothiophene, benzothiadiazole Thiophene or a combination of these groups. Heteroaryl groups can also be substituted with alkyl, alkoxy, sulfanyl, fluoro, fluoroalkyl, or other aryl or heteroaryl groups.

In the context of this application, the term "(non-aromatic) cycloaliphatic group" encompasses saturated rings and "heterocyclyl" encompasses saturated rings, that is, those that exclusively contain single bonds, and partially unsaturated rings, That is, they can also contain multiple bonds. The heterocyclic ring contains one or more heteroatoms preferably selected from Si, O, N, S and Se. (Non-aromatic) cycloaliphatic and heterocyclic groups can be monocyclic, that is, contain only one ring (such as cyclohexane) or polycyclic, that is, contain multiple rings (such as decalin or bicyclooctyl alkyl). In addition, monocyclic, bicyclic or tricyclic groups having 3 to 25 C atoms are preferred, which optionally contain fused rings and are optionally substituted. In addition, it is preferably a 5-membered, 6-membered, 7-membered, or 8-membered carbocyclic group. In addition, one or more C atoms may be substituted by Si and / or one or more CH groups may be substituted by N and / Or one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-. Preferred cycloaliphatic and heterocyclic groups are, for example, 5-membered groups such as cyclopentane, tetrahydrofuran, tetrahydrothiofuran, and pyrrolidine; 6-membered groups such as cyclohexane, cyclohexylsilane, tetrahydropiperidine Pyran, tetrahydrothiopiperan, 1,3-dioxane, 1,3-dithia, piperidine; 7-membered groups such as cycloheptane; and fused groups such as tetralin, decahydro Naphthalene, Indan, Bicyclo [1.1.1] pentane-1,3-diyl, Bicyclo [2.2.2] octane-1,4-diyl, Spiro [3.3] heptane-2,6-diyl Octahydro-4,7-methyl bridge indane-2,5-diyl, more preferably 1,4-cyclohexyl 4,4'-dicyclohexyl, 3,17-hexadecane-cyclopentyl [a] phenanthrene, optionally substituted with one or more of the same or different groups L. Particularly preferred aryl, heteroaryl, cycloaliphatic and heterocyclic groups are 1,4-phenylene, 4,4'-biphenyl, 1,4-triphenyl, 1,4 -Cyclohexyl, 4,4'-dicyclohexyl, and 3,17-hexadecyl-cyclopenta [a] -phenanthrene, which are optionally substituted with one or more same or different groups L.

Preferred substituents (L) of the aryl, heteroaryl, cycloaliphatic and heterocyclic groups mentioned above are, for example, a solubility-promoting group (such as an alkyl group or an alkoxy group) and an electron-withdrawing group (Such as fluorine, nitro or nitrile).

Particularly preferred substituents are, for example, halogen, CN, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF _3. OCHF ₂ or OC ₂ F ₅ .

Above and below, "halogen" means F, Cl, Br or I.

In the above and below, the terms "alkyl", "aryl", "heteroaryl" and the like also encompass polyvalent groups such as alkylene, aryl, heteroaryl and the like.

The term "aryl" refers to an aromatic carbon group or a group derived therefrom.

The term "heteroaryl" refers to an "aryl" containing one or more heteroatoms as defined above.

Preferred alkyl groups are, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, third butyl, 2-methylbutyl, n-pentyl, Dipentyl, cyclopentyl, n-hexyl, cyclohexyl, 2-ethylhexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, n-decyl, n-undecyl, N-dodecyl, dodecyl, trifluoromethyl, perfluoro-n-butyl, 2,2,2-trifluoroethyl, perfluorooctyl, perfluorohexyl and the like.

Preferred alkoxy groups are, for example, methoxy, ethoxy, 2-methoxy-ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, second butoxy , Third butoxy, 2-methylbutoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonoxy, n-decoxy, n-undecyloxy N-dodecyloxy.

Preferred alkenyl groups are, for example, vinyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl and octenyl.

Preferred alkynyl is, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl.

An oxaalkyl group, that is, one of the CH ₂ groups is replaced by -O-, and is preferably, for example, a linear 2-oxopropyl group (= methoxymethyl); a 2-oxobutyl group (= ethoxy group) Methyl) or 3-oxobutyl (= 2-methoxyethyl); 2-oxopentyl, 3-oxopentyl or 4-oxopentyl; 2-oxexyl, 3 -Oxahexyl, 4-oxahexyl or 5-oxahexyl; 2-oxaheptyl, 3-oxaheptyl, 4-oxaheptyl, 5-oxaheptyl or 6-oxaheptyl Base; 2-oxaoctyl, 3-oxaoctyl, 4-oxaoctyl, 5-oxaoctyl, 6-oxaoctyl or 7-oxaoctyl; 2-oxanonyl , 3-oxanonyl, 4-oxanonyl, 5-oxanonyl, 6-oxanonyl, 7-oxanonyl or 8-oxanonyl or 2-oxadecyl, 3-oxadecyl, 4-oxadecyl, 5-oxadecyl, 6-oxadecyl, 7-oxadecyl, 8-oxadecyl or 9-oxadecyl.

Preferred amine groups are, for example, dimethylamino, methylamino, methylaniline, and aniline.

The term "palace" is generally used to describe an object that cannot overlap its mirror image.

An "achiral / non-chiral" object is the same as its mirror image.

Unless explicitly stated otherwise, in this application, the term "palate nematic" is used synonymously with "cholesterol."

The term "dual mesogen" refers to a compound that contains two mesogen groups in the molecule. Just like the normal mesogen, depending on its structure, it can form many mesophases. In particular, when added to a nematic liquid crystal medium, a dual mesogen compound can induce a second nematic phase. Dual mesogen compounds are also called "dimeric liquid crystals".

The term "director" is known in the prior art and means a preferred orientation direction of the long molecular axis (in the case of rod-like compounds) or the short molecular axis (in the case of disc-shaped compounds) of liquid crystal molecules. In the case of uniaxial ordering of these anisotropic molecules, the director is the anisotropic axis.

The term "alignment" or "orientation" refers to the alignment (orientation ordering) of anisotropic units of a material, such as small molecules or macromolecular fragments in a common direction called "alignment direction". In the alignment layer of the liquid crystal material, the liquid crystal director is aligned with the alignment direction so that the alignment direction corresponds to the direction of the anisotropic axis of the material.

The term "planar orientation / alignment" means, for example, in a layer of liquid crystal material, a long molecular axis (in the case of a rod-like compound) or a short molecular axis (in the case of a discotic compound) of a certain proportion of liquid crystal molecules and the layer The planes are oriented substantially parallel (about 180 °).

The term "vertical orientation / alignment" means, for example, in the layer of a liquid crystal material, a long molecular axis (in the case of a rod-like compound) or a short molecular axis (in the case of a discotic compound) of a certain proportion of liquid crystal molecules relative to The plane of the layers is oriented at an angle θ ("tilt angle") between about 80 ° and 90 °.

The term "uniform orientation" or "uniform alignment" of liquid crystal materials, for example, means that the long molecular axis (in the case of rod-like compounds) or the short molecular axis (in the case of discoid compounds) of liquid crystal molecules in the layer of the material are basically Up in the same direction. In other words, the lines of the liquid crystal director are parallel.

Unless specifically stated otherwise, the wavelength of light generally referred to in this application is 550 nm.

The birefringence Δn is defined by the following equation
Dn = n _e -n _o
Where n _e is the abnormal refractive index and n _o is the ordinary refractive index, and the effective average refractive index n _{av. Is} given by the following equation:
n _av. = [(2 n _o ² + n _e ² ) / 3] ^1/2

Refractile metering extraordinary refractive index n _e measured ordinary refractive index n _o and an Abbe (Abbe).

In this application, the term "dielectric positive" is used for compounds or components with Δε> 3.0, "dielectric neutral" is used for compounds or components with -1.5 ≤ Δε ≤ 3.0 and "dielectric negative" "For compounds or components with Δε <-1.5. Δε was measured at a frequency of 1 kHz and at 20 ° C. The dielectric anisotropy of each compound is determined from the result of a 10% solution of each single compound in a nematic host mixture. If the solubility of each compound in the host medium is less than 10%, reduce its concentration by a factor of two until the resulting medium is sufficiently stable to allow at least its properties to be determined. However, in order to keep the significance of the results as high as possible, it is preferable to keep the concentration at least 5%. The capacitance of the test mixture is measured in cells with vertical and creeping orientations. The cell gap for both types of cells is approximately 20 µm. The applied voltage is a rectangular wave with a frequency of 1 kHz and a root mean square value of usually 0.5 V to 1.0 V; however, it is always chosen to be below the capacitance threshold of the respective test mixture.

Δε is defined as (e _½½ -e _^ ), and ε _av. Is (e _½½ + 2 e _^ ) / 3. The dielectric permittivity of a compound is determined by changes in the respective values of the host medium after the relevant compound is added. Extrapolate these values to 100% related compound concentrations. Typical host media are ZLI-4792 or BL-087, both available from Merck, Darmstadt.

For the present invention,

For trans-1,4-cyclohexyl,

Represents 1,4-phenylene.

For the present invention, the group -COO- -C (= O) O- or -CO ₂ -represents having the formula An ester group, and the groups -OCO-, -OC (= O)-, -O ₂ C-, or -OOC- represent a formula Of an ester group.

In addition, the definitions given in C. Tschierske, G. Pelzl and S. Diele, Angew. Chem. 2004, 116, 6340-6368 will apply to the undefined terms regarding liquid crystal materials in this application.

In the case of a compound having a non-polar group, R ^{12 is} preferably an alkyl group, an alkoxy group, an alkenyl group or an alkynyl group, preferably an alkyl group or an alkoxy group, which has at most 15 C atoms, preferably 2 Up to 10 C atoms, more preferably 2 to 5 C atoms.

Furthermore, compounds of formula I containing a non-palladium branched group R ¹² may occasionally be of importance, for example due to a reduced tendency towards crystallization. This type of branched chain group usually does not contain more than one chain branch. Preferred non-palladium branched groups are isopropyl, isobutyl (= methylpropyl), isoamyl (= 3-methylbutyl), isopropyloxy, 2-methyl-propyl And 3-methylbutoxy.

In the case of a compound having a terminal polar group, R ¹² is selected from CN, NO ₂ , NCS, NCO, halogen, OCH ₃ , OCN, SCN, COR ^x , COOR ^x or a single having 1 to 4 C atoms Fluorinated, oligofluorinated or polyfluorinated alkyl or alkoxy. R ^x is an optionally fluorinated alkyl group having 1 to 4, preferably 1 to 3 C atoms. The halogen is preferably F or Cl.

Particularly preferred R ¹² in formula I is selected as NO ₂ , NCS or NCO.

More preferably R ¹¹ is the same as R ¹² and represents NO ₂ , NCS or NCO.

Especially preferred is a sub-formula, in which Z independently has one of the meanings of Z ¹¹ given in Formula I in each case, and if there are two, one of Z is preferably -COO-,- OCO-, -CF ₂ -O- or -O-CF _2- .

Preferred groups containing only a 6-membered ring -A ¹¹ (-Z ¹¹ -A ^12- ) _p -or-(A ¹³ -Z ^12- ) _q A ¹⁴ -are listed below. For simplicity, Phe in these groups is 1,4-phenylene, and PheL is 1,4-phenylene substituted with 1 to 4 groups L, where L is preferably F, Cl, CN , OH, NO ₂ or optionally fluorinated alkyl, alkoxy or alkanoyl groups having 1 to 7 C atoms, preferably F, Cl, CN, OH, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , especially F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ and OCF ₃ , most preferably F, Cl, CH ₃ , OCH ₃ and COCH ₃ , and CHex is 1,4-cyclohexyl. This list contains the subforms shown below,
among them
CHex is 1,4-cyclohexyl, preferably trans-1,4-cyclohexyl,
Phe is 1,4-phenylene,
PheL is 1,4-phenylene, which is substituted by one, two or three fluorine atoms, by one or two Cl atoms, or by a Cl atom and an F atom, and
Z has one of the meanings of Z ¹¹ as given under Partial Formula II, and if two are present, preferably at least one is selected from -COO-, -OCO-, -OCH _2- , -CH ₂ O- , -OCF ₂ -or -CF ₂ O-.

Especially preferred is the sub-formula, in which Z independently has one of the meanings of Z ¹¹ given in Formula I in each case, and if there are two, it is preferred that one of Z is -COO- or- OCO-.

In the preferred formulae given above, PheL preferably represents a group .

Among them, L is preferably F, Cl, CH ₃ , OCH ₃ and COCH ₃ .

Particularly preferred are compounds of formula I, wherein the respective pairs of mesogen groups -A ¹¹ (-Z ¹¹ -A ^12- ) _p -or-(A ¹³ -Z ^12- ) _q A ¹⁴ -each contain two Or three six-atom rings, more preferably -A ¹¹ (-Z ¹¹ -A ^12- ) _p -or-(A ¹³ -Z ^12- ) _q A ¹⁴ -each containing two six-atom rings or -A ¹¹ ( -Z ¹¹ -A ^12- ) _p -contains two six-atom rings and-(A ¹³ -Z ^12- ) _q A ¹⁴ contains three six-atom rings or -A ¹¹ (-Z ¹¹ -A ^12- ) _p- Contains three six-atom rings and / or-(A ¹³ -Z ^12- ) _q A ¹⁴ -includes two six-atom rings.

In a preferred embodiment, -A ¹¹ (-Z ¹¹ -A ^12- ) _p -or-(A ¹³ -Z ^12- ) _q A ¹⁴ -are selected as mirror images of each other according to the original mesogen groups, for example, if -A ¹¹ (-Z ¹¹ -A ^12- ) _p -represents -Phe-PheL-then-(A ¹³ -Z ^12- ) _q A ¹⁴ represents -PheL-Phe-.

More preferred are compounds of formula I, wherein
Sp ¹¹ represents-(CH ₂ ) _n- , where
n is an integer from 1 to 15, wherein one or more -CH ₂ -groups may be replaced by -CO-, preferably a non-even integer, more preferably 3, 5, 7, 9, 11, or 13,

More preferred compounds of formula I are their compounds, wherein
-X ¹¹ -Sp ¹¹ -X ¹² - is ^{-Sp 11 -, - Sp 11 -O} -, - Sp 11 -CO-O -, - Sp 11 -O-CO -, - Sp 11 -CF 2 O-, -CO-O-Sp ¹¹ , -O-CO-Sp ¹¹ , -O-Sp ^11- , -OCF ₂ -Sp ^11- , -O-Sp ¹¹ -O-, -OCF ₂ -Sp ¹¹ -CF ₂ O -, -O-Sp ¹¹ -CO-O-, -O-Sp ¹¹ -O-CO-, -O-CO-Sp ¹¹ -O-, -O-CO-Sp ¹¹ -O-CO-, -CO -O-Sp ¹¹ -O- or -CO-O-Sp ¹¹ -CO-O-, however the restriction is that no two O atoms are adjacent to each other and no two in -X ¹¹ -Sp ¹¹ -X ^12- -CH = CH- groups are adjacent to each other and no two are selected from -O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-, and -CH = CH -Groups are adjacent to each other.

More preferred compounds of formula I are their compounds, wherein -X ¹¹ -Sp ¹¹ -X ¹² -represents -Sp ^11- , -O-Sp ¹¹ -O-, -OCF ₂ -Sp ¹¹ -CF ₂ O- or- O-CO-Sp ¹¹ -O-CO-,

More preferably the compound of formula I is selected from the following substructures,




among them
Each occurrence of L represents F, Cl, CH ₃ , OCH ₃ and COCH _{3 respectively} , preferably F,
r represents an integer between 0 and 4, preferably 0, 1, or 2,
n represents 3, 5, 7, 9, 11, or 13.

More preferably the compound of formula I is selected from the following substructures,




among them
Each occurrence of L represents F, Cl, CH ₃ , OCH ₃ and COCH _{3 respectively} , preferably F,
n represents 3, 5, 7, 9, 11, or 13, preferably 7, 9, or 11.

Particularly preferred compounds of formula I are selected from the substructures I-1-1 to I-1-3, I-3-1 to I-3-3, I-5-1 to I-5-3 and I- 7-1 to I-7-3, preferably selected from I-1-1, I-1-3, I-3-1, I-3-3, I-5-1, I-5-3, I-7-1 and I-7-3, more preferably selected from I-1-3, I-3-3, I-5-3, and I-7-3, where L represents F and n represents 7, 9 Or 11.

Compounds of formula I can be synthesized according to or in a manner similar to standard works known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart).

For example, one of the main advantages of using compounds of Formula I in LC dielectrics for flexure applications is to increase the switching speed of the ULH (Uniform Transverse Helix) geometry, especially at temperatures below 35 ° C. Advantages have also been observed in phase range, in terms of increased isotropic to nematic clarification points, and in reduced nematic to nematic torsional bending transition temperatures below room temperature.

The invention therefore also relates to the use of compounds of formula I in LC media and thus to LC media comprising one or more compounds of formula I.

In a preferred embodiment, the LC medium according to the present invention comprises one or more compounds of formula II,
R ²¹ -A ²¹ -A ^22- (CH ₂ ) _a -A ²³ -A ²⁴ -R ²² II
among them
R ²¹ and R ²² independently represent H, F, Cl, CN or a linear or branched alkyl group, and the linear or branched alkyl group may be unsubstituted, mono- or poly-substituted with halogen or CN, a Or, multiple non-adjacent CH ₂ groups may also be replaced independently of each other by the following groups at each occurrence: -O-, -S-, -NH-, -N (CH ₃ )-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-CO-, -CO-S-, -CH = CH-, -CH = CF-, -CF = CF- or -C≡C -, The substitution method is such that the oxygen atoms are not directly connected to each other,
Preferred are F, Cl, CN, straight or branched chain alkyl or alkoxy which may be unsubstituted, mono- or poly-substituted with halogen or CN,
More preferably F, CN or OCF ₃ ,
A ²¹ to A ²⁴ each independently represent an aryl group, a heteroaryl group, an alicyclic group, and a heterocyclic group,
1,4-phenylene is preferred, and one or more CH groups may be replaced by N; 1,4-bicyclo- (2,2,2) -octyl; naphthalene-2,6- Diyl; decalin-2,6-diyl; 1,2,3,4-tetrahydro-naphthalene-2,6-diyl; cyclobutane-1,3-diyl; spiro [3.3] heptane Alkan-2,6-diyl or bisspiro [3.1.3.1] decane-2,8-diyl, all such groups may be unsubstituted, via F, Cl, CN or alkyl, alkoxy , Alkylcarbonyl or alkoxycarbonyl mono-, di-, tri- or tetra-substituted in which one or more H atoms may be substituted by F or Cl,
More preferably, each occurrence is independently 1,4-phenylene, and one or more of the CH groups may be replaced by N; or trans-1,4-cyclohexyl, and one or two of them Non-adjacent CH ₂ groups can be replaced by O and / or S, both ring groups may be unsubstituted, F, Cl, CN or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl Mono-, di-, tri- or tetra-substituted, in which one or more H atoms may be substituted by F or Cl,
a represents an integer from 1 to 15, preferably an odd (ie, non-even) integer, and more preferably 3, 5, 7, 9, or 11.

Preferred compounds of formula II are selected from compounds wherein the groups (-A ²¹ -A ^22- ) and (-A ²³ -A ^24- ) are each and independently selected from the following groups
-Phe-Phe- MG1
-PheL-PheL- MG2
-Phe-PheL- MG3
-PheL-Phe- MG4
among them,
Phe is 1,4-phenylene in these groups,
PheL is 1,4-phenylene substituted by 1 to 4 groups L, where L is preferably F, Cl, CN, OH, NO ₂ or optionally fluorinated alkane having 1 to 7 C atoms Group, alkoxy or alkylfluorenyl, preferably F, Cl, CN, OH, NO ₂ , CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , especially F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ and OCF ₃ , most preferably F, Cl, CH ₃ , OCH ₃ and COCH ₃ and
Cyc is 1,4-cyclohexyl.

Preferred is a compound of formula II, wherein the group (R ²¹ -A ²¹ -A ^22- ) in formula II is the same as (-A ²³ -A ²⁴ -R ²² ) or is a mirror image.

Also preferred are compounds of formula II, wherein (R ²¹ -A ²¹ -A ^22- ) in formula II is different from (-A ²³ -A ²⁴ -R ²² ).

Preferred compounds of formula II are shown below:

among them
n represents an integer from 1 to 15, preferably an odd (ie, non-even) integer, and more preferably 3, 5, 7, 9, or 11.

Compounds of formula II can be synthesized according to or in a manner similar to standard writings known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart). A preferred method of preparation is available from WO 2013/004333 A1.

In order to further increase the switching speed while maintaining an excellent phase range and favorable e / K values, it is particularly useful to employ a compound of formula II in addition to the compound of formula I in the mixture according to the invention.

In a preferred embodiment, the LC medium according to the present invention comprises one or more compounds of formula III,
R ³¹ -A ³¹ -A ^32- (A ³³ ) _b -Z ^31- (CH ₂ ) _c -Z ³² -A ³⁴ -A ³⁵ -A ³⁶ -R ³² III
among them
R ³¹ and R ³² each have, independently of one another, one of the meanings given for R ²¹ and R ²² under Formula II,
A ³¹ to A ³⁶ each and independently of one another have the meaning given for A ²¹ to A ²⁴ under Formula II,
Z ³¹ and Z ³² are each independently -COO-, -OCO-, -O-CO-O-, -CF ₂ -O-, -O-CF _2- , -OCH ₂ -,- CH ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO- CH = CH- or -C≡C-, these groups are optionally substituted by one or more F,
Preferably -COO-, -OCO- or -O-CO-O-,
More preferably -COO- or -OCO-,
c represents an integer from 1 to 15, preferably an odd (i.e. non-even) integer, and more preferably 3, 5, 7, or 9, and
b represents 0 or 1, preferably 0.

Preferred compounds of formula III are selected from compounds in which c represents 0 and the group (-A ³¹ -A ^32- ) is selected from the groups MG1 to MG4 as given above.

More preferred compounds of formula III are selected from the group in which c represents 1 and the groups (-A ²⁴ -A ²⁵ -A ^26- ) and (-A ²¹ -A ²² -A ^23- ) are each independently selected from the following groups: Compound
-Phe-Phe-Phe- MG5
-Phe-Phe-PheL- MG6
-Phe-PheL-Phe- MG7
-PheL-Phe-Phe- MG8
-PheL-Phe-PheL- MG9
-PheL-PheL-Phe- MG10
-PheL-PheL-PheL- MG11
among them
Phe, PheL and L have one of the meanings given above for the groups MG-1 to MG-4.

More preferred compounds of formula III are selected from the group wherein c represents 0 and the group (-A ²¹ -A ^22- ) is selected from the groups MG1 to MG4 as given above and wherein the group (-A ²⁴ -A ^25- A ^26- ) A compound selected from the groups MG5 to MG11.

Particularly preferred compounds of formula III are selected from the group of compounds of the formula:

Compounds of formula III can be synthesized according to or in a manner similar to standard writings known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart).

In order to achieve a higher stability, a favorable higher clarification point and a wider phase range, and a lower presentation of the nematic twist-bent phase, the compounds according to the invention are also used in addition to the compounds of the formula III in the mixtures according to the invention. Compounds are particularly useful.

In a more preferred embodiment, the LC medium according to the invention comprises one or more compounds of formula IV,
R ⁴¹ -A ⁴¹ -A ⁴² -Z ^41- (CH ₂ ) _d -Z ⁴² -A ⁴³ -A ⁴⁴ -R ⁴² IV
among them
R ⁴¹ and R ⁴² each have independently one of the meanings given above for R ²¹ under Formula II,
A ⁴¹ to A ⁴⁴ each have, independently of one another, one of the meanings given above for A ²¹ under Formula II,
Z ⁴¹ and Z ⁴² are each independently -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -CH ₂ CH ₂ -,-( CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO- CH = CH- or -C≡C-, these groups are optionally substituted by one or more F,
Preferably -COO-, -OCO- or -O-CO-O-,
More preferably, it is -COO- or -OCO-.
d represents an integer from 1 to 15, preferably an odd (ie, non-even) integer, and more preferably 3, 5, 7, or 9.

Preferred compound is selected from formula IV wherein the groups of (-A ⁴¹ -A ⁴² -) and (-A ⁴³ -A ⁴⁴ -) group are each independently selected as described above and set forth in the MG1 through MG4 Compound.

Particularly preferred compounds of formula IV are selected from the group of compounds of the formula:
-Symmetric compounds (IVa and IVb):




-Asymmetric compounds (IVc):

Compounds of formula IV are known or can be synthesized according to or in a manner similar to standard works known per se and described in organic chemistry (eg Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart).

In order to reduce the nematic twist and bend while maintaining a favorable e / K value, it is particularly useful to use a compound of formula IV in addition to the compound of formula I in the mixture according to the invention.

In a more preferred embodiment, the LC medium according to the invention further comprises one or more compounds of formula V,
R ⁵¹ -A ⁵¹ -Z ^51- (CH ₂ ) _e -Z ⁵² -A ^52- (A ⁵³ ) _f -R ⁵² V
among them
R ⁵¹ and R ⁵² each have, independently, one of the meanings given above for R ²¹ under Formula II,
A ⁵¹ to A ⁵³ each have, independently of one another, one of the meanings given above for A ²¹ under Formula II,
Z ⁵¹ and Z ⁵² are each independently -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -CH ₂ CH ₂ -,-( CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO- CH = CH- or -C≡C-, these groups are optionally substituted by one or more F,
Preferably -COO-, -OCO- or -O-CO-O-,
More preferably -COO- or -OCO-,
e represents an integer from 1 to 15, preferably an odd (i.e. non-even) integer, and more preferably 3, 5, 7, or 9, and
f represents 0 or 1.

Particularly preferred are compounds of formula V in which A ⁵¹ is selected from the group of formulae Va 'to Vf' and mirror images of formulas Vd 'and Ve'.

Preferably, R ⁵¹ and R ⁵² in formula V are selected as H, F, Cl, CN, NO ₂ , OCH ₃ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , C ₂ F ₅ , OCF ₃ , OCHF ₂ and OC ₂ F ₅ , especially H, F, Cl, CN, OCH ₃ and OCF ₃ , especially H, F, CN and OCF ₃ .

Preferred compounds of formula V are selected from the group of compounds of formulas VA to VD, preferably of formula VA and / or VC, and of formula VC,

among them
LG ⁵¹ is Z ^51- (CH ₂ ) _z -Z ⁵² ,
(F) ₀ represents H, and
(F) ₁ means F.
And other parameters have their respective meanings given above, including better meanings.

Preferably, Z ^51- (CH ₂ ) _z -Z ⁵² represents -O-CO- (CH ₂ ) _n -CO-O-, -O- (CH ₂ ) _n -O- or-(CH ₂ ) _n- , More preferably -O-CO- (CH ₂ ) _n -CO-O-, wherein n represents 3, 5, 7, or 9.

Particularly preferred compounds of formula VA are selected from the group of compounds of formulas VA-1 to VA-3:

The parameters have the respective meanings given above, including preferred meanings.

Particularly preferred compounds of formula VB are selected from the group of compounds of formulas VB-1 to VB-3:


The parameters have the respective meanings given above, including preferred meanings.

Compounds of formula VC are excellent. And particularly preferred compounds among them are selected from the group of compounds of the formulae VC-1 to VC-3:

The parameters have the respective meanings given above, including preferred meanings.

Compounds of formula V can be synthesized according to or in a manner similar to standard writings known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart). A preferred method of preparation is disclosed, for example, in WO2015 / 036079 A1.

In a more preferred embodiment, the LC medium according to the present invention further comprises one or more compounds of formula VI,
R ⁶¹ -A ⁶¹ -A ^62- (CH ₂ ) _g -Z ⁶¹ -A ⁶³ -A ^64- (A ⁶⁵ ) _h -R ⁶² VI
among them
R ⁶¹ and R ⁶² each have independently one of the meanings given above for R ²¹ under Formula II,
A ⁶¹ to A ⁶⁴ each have independently one of the meanings given above for A ²¹ under Formula II,
Z ⁶¹ represents -O-, -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH- or -C≡ C-, these groups are optionally substituted with one or more F, S and / or Si,
Preferably -O-, -COO-, -OCO-, or -O-CO-O-,
More preferably -O-, -COO- or -OCO-, most preferably -COO- or -OCO-,
h is 0 or 1, and
g represents an integer from 1 to 15, preferably an odd (ie, non-even) integer, and more preferably 3, 5, 7, or 9.

Preferred compounds of formula VI are selected from the group wherein the groups (-A ⁶¹ -A ^62- ) and (-A ⁶³ -A ^64- ) are each and independently selected from the groups MG1 to MG4 given above. Compound.

More preferred are those in which h represents 0 and the groups (-A ⁶¹ -A ^62- ) and (-A ⁶³ -A ^64- (A ⁶⁵ ) _h ) in Formula VI are different or not mirror images or where h represents 1 Compound of Formula VI.

Particularly preferred compounds of formula VI are selected from the group of compounds of the formula:

Compounds of formula VI can be synthesized according to or in a manner similar to standard writings known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart). Preferably, the compound of formula VI is synthesized according to or in a manner similar to that disclosed in WO 2014/005672 A1.

In order to obtain higher clearing points and advantageous e / K values, it is particularly useful to use compounds of formula VI in addition to compounds of formula I in the mixtures according to the invention.

In a more preferred embodiment, the LC medium according to the present invention further comprises one, two, three or more compounds of formula VII,
^{R 71 -A 71 -Z 71 -A 72} - (Z 72 -A 73) i - (CH 2) j - (A 74 -Z 73 -) k -A 75 -Z 74 -A 76 -R 72 VII
among them
R ⁷¹ and R ⁷² each and independently have one of the meanings given above for R ²¹ under Formula II,
A ⁷¹ to A ⁷⁶ each and independently have one of the meanings given above for A ²¹ under Formula II,
Z ⁷¹ to Z ⁷⁴ each independently represent -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -OCF _2- , -CF ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH- or -C ≡C-, these groups are optionally substituted by one or more F, S and / or Si, or represent a single bond,
-COO-, -OCO-, -O-CO-O-, -OCF _2- , -CF ₂ O- or a single bond is more preferred -COO-, -OCO-, -OCF _2- , -CF ₂ O- or single bond,
The restriction is that at least one of Z ⁷¹ to Z ⁷⁴ is not a single bond,
j represents an integer from 1 to 15, preferably an odd (i.e., non-even) integer, and more preferably 3, 5, 7, or 9, and
i and k each represent 0 or 1 independently.

Preferred compounds of formula VII selected lines wherein the group ^{-A 71 -Z 71 -A 72 - (} Z 72 -A 73) i -, - (A 74 -Z 73 -) k -A 75 -Z 74 - A ⁷⁶ -at least one compound selected from the group consisting of MGa to MGn and its mirror image


Among them, preferably L is independently F, Cl, CN or optionally fluorinated alkyl, alkoxy or alkylfluorenyl having 1 to 7 C atoms, and most preferably F, Cl in each occurrence. , CN, CH ₃ , C ₂ H ₅ , OCH ₃ , OC ₂ H ₅ , COCH ₃ , COC ₂ H ₅ , COOCH ₃ , COOC ₂ H ₅ , CF ₃ , OCF ₃ , OCHF ₂ , OC ₂ F ₅ , especially F, Cl, CN, CH ₃ , C ₂ H ₅ , OCH ₃ , COCH ₃ and OCF ₃ , most preferably F, Cl, CH ₃ , OCH ₃ and COCH ₃ , and r are independent of each other at each occurrence It is 0, 1, 2, 3, or 4, preferably 0, 1, or 2.

Among them, L is preferably F, Cl, CH ₃ , OCH ₃ and COCH ₃ .

Better system of formula VII wherein the group ^{-A 71 -Z 71 -A 72 - (} Z 72 -A 73) i - and ^{- (A 74 -Z 73 -)} k -A 75 -Z 74 -A 76 A compound of formula VII that is the same or mirror image, with the proviso that at least one of Z ⁷¹ to Z ⁷⁴ is not a single bond.

A more preferred compound of formula VII, wherein i and k each represent a 1, more preferably one of i and k represents 0 and the other represents 1, and most preferably i and k each represent 0.

Particularly preferred compounds of formula VII are selected from the group of compounds of the formula:



Here, R ⁷¹ and R ⁷² each independently represent F or CN.

Compounds of formula VII can be synthesized according to or in a manner similar to standard works known per se and described in organic chemistry (for example, Houben-Weyl, Methoden der organischen Chemie, Thieme-Verlag, Stuttgart). Preferably, the compound of formula VII is synthesized according to or in a manner similar to that disclosed in, for example, WO 2013/174478 A1.

In a more preferred embodiment, the medium according to the invention optionally contains one or more pairs of palmar dopants, especially when used in flexure electrical devices.

The palmar compound induces a palmar nematic structure with a pitch (P ₀ ), which is inversely proportional to the concentration of the palmitic material (c) used under a first order approximation. The constant of the ratio of this relationship is called the helical twisting power (HTP) of the palm material and is defined by the following equation
HTP ≡ 1 / (c · P ₀ ) (1)
among them
c is the concentration of palmar compounds.

For example, a uniform lateral spiral structure is achieved using a palmitic nematic liquid crystal having a short pitch, typically in the range of 0.2 μm to 1 μm, preferably 1.0 μm or less, especially 0.5 μm or less. In-line liquid crystals are unidirectionally aligned in such a manner that the spiral axis thereof is parallel to the substrate (such as a glass plate) of the liquid crystal cell. In this configuration, the spiral axis of a palmitic nematic liquid crystal is equivalent to the optical axis of a birefringent plate.

The preferred are dopant dopants having high helical twisting force (HTP), especially the dopant dopants disclosed in WO 98/00428.

Commonly used dopants are, for example, commercially available R / S-5011, CD-1, R / S-811, and CB-15 (from Merck KGaA, Darmstadt, Germany).

In another preferred embodiment, the palm dopant is preferably selected from Formula VIII,

And / or formula IX,

Including the individual (S, S) enantiomers,
Where E and F are each independently 1,4-phenylene or trans-1,4-cyclohexyl, v is 0 or 1, and Z ⁰ is -COO-, -OCO-, -CH ₂ CH ₂ -or Single bond, and R is an alkyl, alkoxy or alkylfluorenyl group having 1 to 12 C atoms.

Compounds of formula VIII and their synthesis are described in WO 98/00428. Compounds of formula IX and their synthesis are described in GB 2,328,207.

The aforementioned palmitic dopants R / S-5011 and the compounds of the formulae VIII and IX exhibit extremely high helical twisting forces (HTP) and are therefore particularly suitable for the purposes of the present invention.

The liquid crystal medium preferably contains 1 to 5, especially 1 to 3, and 1 or 2 palmitic dopants, which are preferably selected from the above formula VIII and / or formula IX and / or R-5011 or S -5011, which is an excellent palm compound R-5011, or S-5011.

The amount of the palmitic compound in the liquid crystal medium is preferably 0.1% to 15% by weight, especially 0.5% to 10% by weight, and very preferably 1% to 5% by weight of the total mixture.

Preferably, the LC medium comprises one or more nematic LC compounds selected from the compounds shown below:


among them
R ^2A represents H, an alkyl group or an alkoxy group having 1 to 15 C atoms, and in addition, one or more of the CH ₂ groups in these groups may be independently replaced with each other by the following groups: -C≡ C-, -CF ₂ O-, -CH = CH-, , , -O-, -CO-O- or -O-CO-, the substitution method is such that O atoms are not directly connected to each other, and one or more H atoms can be replaced by halogen,
L ¹ and L ² each independently represent F, Cl, CF ₃ or CHF ₂ , preferably each represents F,
Z ² and Z ^{2 '} each independently represent a single bond, -CH ₂ CH _2- , -CH = CH-, -C≡C-, -CF ₂ O-, -OCF _2- , -CH ₂ O-, -OCH _2- , -COO-, -OCO-, -C ₂ F _4- , -CF = CF- or -CH = CHCH ₂ O-,
p is 0, 1, or 2,
q means 0 or 1,
(O) C _v H _{2v + 1} means OC _v H _{2v + 1} or C _v H _{2v + 1} , and
v represents 1 to 6.

The liquid crystal medium may contain other additives in common concentrations, such as, for example, stabilizers, inhibitors, surface-active compounds, lubricants, wetting agents, dispersants, hydrophobic agents, adhesives, flow improvers, defoamers, deaerators, Diluents, reactive diluents, auxiliaries, colorants, dyes, pigments or nano particles. The total concentration of these other components is in the range of 0.1% to 10%, preferably 0.1% to 6%, based on the total mixture. The concentrations of the individual compounds used are each preferably in the range of 0.1% to 3%.

For the values and ranges of the concentration of the liquid crystal components and compounds of the liquid crystal medium in this application, the concentrations of these and similar additives are not considered. This also applies to the concentration of dichroic dyes used in the mixture. When the concentrations of the compounds and components of the host medium are separately specified, the concentration of dichroic dyes is not calculated. The concentrations of the individual additives are always given relative to the final doping mixture.

In general, the total concentration of all compounds in the medium according to the application is 100%.

The liquid crystal medium according to the present invention is composed of several compounds, preferably 2 to 40, more preferably 3 to 30, and most preferably 4 to 25 compounds.

The medium according to the invention exhibits a higher value of the elastic constant k ₁₁ and a higher deflection coefficient e. The liquid crystal medium preferably exhibits k ₁₁ ≦ 100 pN, and preferably ≦ 20 pN.

The liquid crystal medium preferably exhibits k ₃₃ ≤ 100 pN, and preferably ≤ 15 pN.

The liquid crystal medium preferably exhibits a flexural coefficient │e ₁₁ ≧ 0.2 pC / m, and preferably ≧ 1 pC / m.

The liquid crystal medium preferably exhibits a flexural coefficient │e ₃₃ │ ≧ 0.2 pC / m, and preferably ≧ 2 pC / m.

The liquid crystal medium preferably exhibits a flexibility-elasticity ratio (ē / K) in the range of 1 to 10 V ^-1 , preferably in the range of 1 to 7 V ^-1 , and more preferably in the range of 1 to 5 V ^-1 .

The medium according to the invention exhibits a high clearing point of at most 60 ° C and higher, preferably at most 65 ° C and higher and more preferably at most 70 ° C and higher.

The medium according to the invention exhibits a wide nematic phase of 30 ° C and higher, preferably 35 ° C and higher or even 40 ° C or higher.

The medium according to the invention exhibits an N _TB phase below 20 ° C or less, preferably below 15 ° C or less and more preferably below 0 ° C or less.

The medium according to the invention exhibits a high resistance to crystallization at room temperature for more than 100 hours, preferably more than 250 hours or more than 1000 hours.

The medium according to the invention exhibits a high resistance to crystallisation (LTS) even at low temperatures. Accordingly, the medium does not crystallize even at temperatures as low as 0 ° C, preferably as low as -10 ° C, and more preferably as low as -20 ° C.

In a preferred embodiment, the LC medium includes:
1 to 10, preferably 1 to 5, more preferably 1 or 3, most preferably 1 or 2 compounds of formula I. The amount of the compound of formula I in the liquid crystal medium as a whole is preferably in the range of 5 to 50% by weight of the total mixture, especially in the range of 6 to 30% by weight, especially in the range of 7 to 20% by weight
And · as the case may be 1 to 10, preferably 1 to 5, more preferably 1 or 3, and most preferably 1 or 2 compounds of formula II, the compounds of formula II are preferably selected from among (-A ²¹ -A ^22- ) and (-A ²³ -A ^24- ) are the same or mirror-image compounds of formula II, more preferably compounds of formula II'a-5 and / or II'a-6. If present, the amount of the compound of formula II in the liquid crystal medium is preferably in the range of 0 to 30% by weight, more preferably 1 to 20% by weight, even more preferably 2 to 10% by weight,
And / or, as the case may be, 1 to 10, preferably 1 to 5, more preferably 1 or 3, and most preferably 1 or 2 compounds of formula III, and the compounds of formula III are preferably selected from the above formula IIIc-2 and / Or IIIc-3 symmetrical compounds. If present, the amount of the compound of formula III in the liquid crystal medium is preferably in the range of 1 to 50% by weight, more preferably 5 to 30% by weight, even more preferably 10 to 20% by weight,
And / or, as the case may be, 1 to 10, preferably 1 to 5, more preferably 1 or 3, and most preferably 1 or 2 compounds of formula IV, which compounds of formula IV are preferably selected from symmetric compounds IVb and / or non- The symmetric compound IVc is more preferably selected from Formula IVb-5, IVc-2, IVc-3, IVc-12 and / or IVc-15. If present, the amount of the compound of formula IV in the liquid crystal medium is preferably in the range of 1 to 98% by weight, more preferably 20 to 80% by weight, even more preferably 30 to 60% by weight,
And / or, as the case may be 1 to 6, especially 2 to 5, excellent 3 or 4 compounds of formula V, the compounds of formula V are preferably selected from the above formulas VA-1, VC-2 and / or VC- 3. If present, the amount of the compound of formula V in the liquid crystal medium is preferably within a range from 1 to 70% by weight, more preferably from 10 to 60% by weight, even more preferably from 20 to 50% by weight,
And / or, as appropriate, 1 to 10, preferably 1 to 5, more preferably 1 or 3, and most preferably 1 or 2 compounds from the above formula VI, preferably in the formulae VI-4, VI-5, VI- 7 and / or VI-8 compounds. If present, the amount of the compound of formula VI in the liquid crystal medium is preferably 1 to 40% by weight, especially 5 to 25% by weight, very preferably 10 to 15% by weight,
And / or, as appropriate, 1 to 10, preferably 1 to 5, more preferably 1 or 3, and most preferably 1 or 2 compounds from the above formula VII, preferably in the form of formulas VII-4, VII-5, and / or Compound of VII-8. If present, the amount of the compound of formula VII in the liquid crystal medium is preferably from 1 to 35% by weight, especially from 5 to 25% by weight, very preferably from 10 to 15% by weight,
And / or, as the case may be, 1 to 5, especially 1 to 3, excellent 1 or 2 types of palmar dopants, preferably selected from the above formula VIII and / or formula IX and / or R-5011 or S- 5011, an excellent palmar compound is R-5011 or S-5011. If present, the amount of the palmitic compound in the liquid crystal medium is preferably 1 to 15% by weight, especially 0.5 to 10% by weight, and very preferably 0.1 to 5% by weight,
And / or up to 25, especially up to 20, and preferably up to 15 different compounds selected from the compounds of formula X, as the case may be. If present, the amount of the compound of formula X in the liquid crystal medium as a whole is preferably from 1 to 50% by weight, especially from 5 to 30% by weight, very preferably from 10 to 25% by weight,
And / or · other additives, such as stabilizers, antioxidants, etc., at commonly used concentrations, as appropriate. If present, the total concentration of these other components is in the range of 0.1% to 10%, preferably 0.1% to 6%, based on the total mixture. The concentrations of the individual compounds used are each preferably in the range of 0.1% to 3%.

In another preferred embodiment, the LC medium of the present invention consists only of a compound selected from the formulae I to X, and most preferably the LC medium consists of a compound selected from the formulae I to IX.

In another preferred embodiment, the LC medium of the present invention consists only of compounds selected from Formulae I to X, wherein each of these compounds does not contain a CN group. It is well known that cyano-containing materials have problems when considering active driving. This is due to the decrease in VHR (Voltage Holding Rate) and other reliability related parameters, such as image sticking. Another advantage of cyano-free materials is that they are generally less toxic and more environmentally friendly. This makes the synthesis and subsequent shipment of cyano-free materials more attractive than cyano-containing materials.

The compounds are mixed in a conventional manner to form the LC medium according to the invention. Generally, a smaller amount of the required compound is dissolved in a larger amount of the compound. If the temperature is above the clearing point of the compound used at a higher concentration, it is particularly easy to observe the completion of the dissolution process. However, it is also possible to prepare the medium by other known methods, for example, using a so-called premix, which can be, for example, a homologous or eutectic medium of a compound, or a so-called multi-bottle system, whose components are ready-to-use medium. The invention therefore also relates to a method for preparing LC media as described above and below.

In particular, the present invention relates to a method for preparing an LC medium, the method comprising the step of mixing one or more compounds of the formula I, wherein at least one compound is selected from the compounds of the formulae II to X.

The liquid crystal medium according to the present invention can be used in an electro-optical device, such as a liquid crystal device, such as STN, TN, AMD-TN, temperature compensation, guest-host, phase shift or surface-stabilized or polymer-stabilized cholesterol-type structures (SSCT, PSCT ) Display; used in active and passive optical elements, such as polarizers, compensators, reflectors, alignment layers, color filters or holographic elements; used in adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, Diagnostic equipment, liquid crystal pigments; used in decorative and safety applications; used in non-linear optics, optical information storage or as a dopant for the palm. Therefore, another aspect of the present invention is the use of an LC medium containing at least one compound of Formula I in an electro-optical device.

This is because the medium according to the present invention is particularly advantageous for use in flex electric liquid crystal display applications, such as devices in ULH or USH mode.

Therefore, another object of the present invention is a liquid crystal device, preferably a flexural electrical device, comprising a medium, the medium comprising one or more compounds of formula I.

A flex electric display according to a preferred embodiment of the present invention includes two plane-parallel substrates, preferably the inner surface of which is covered with a transparent conductive layer, such as a glass plate of indium tin oxide (ITO); an alignment layer as appropriate; and A medium comprising one or more compounds of formula I and a palmitic dopant as described above and below.

If an electric field is applied to this configuration perpendicular to the helix axis, the optical axis rotates in the plane of the cell, similar to a director of a strongly-inductive liquid crystal rotating in a surface-stabilized, strongly-inductive liquid crystal display.

The field induces a tilt-bend structure in the director, which is adjusted by the tilt of the optical axis. The rotation angle of the shaft is approximately directly and linearly proportional to the strength of the electric field. When the liquid crystal cell is placed between the orthogonal polarizers and the optical axis of the polarizer and the absorption axis of one of the polarizers are at an angle of 22.5 °, the optical effect is best. This 22.5 ° angle is also the ideal rotation angle of the electric field. Therefore, the optical axis is rotated by 45 ° by reversing the electric field, and the relative direction of the preferred axis of the spiral axis, the absorption axis of the polarizer, and the direction of the electric field are appropriately selected. Orientation allows the optical axis to switch from parallel to one polarizer to the center angle between the two polarizers. Optimal contrast is then achieved when the total angle of the optical axis transition is 45 °. In this case, the configuration can be used as a switchable quarter-wave plate, provided that the optical retardation, that is, the product of effective birefringence of the liquid crystal and the cell gap, is selected to be a quarter of the wavelength. Unless explicitly stated otherwise, the wavelength mentioned in this context is 550 nm, and the human eye has the highest sensitivity to this wavelength.

The rotation angle (Φ) of the optical axis is well approximated by the following formula:
tan Φ = e P ₀ E / (2 π K )
among them
P ₀ is the undisturbed pitch of the cholesteric liquid crystal,
ē is the average of the inclination deflection coefficient (e ₁₁ ) and the bending deflection coefficient (e ₃₃ ) [ē = ½ (e ₁₁ + e ₃₃ )],
E is the electric field strength, and
K is the average of the inclination elastic constant (k ₁₁ ) and the bending elastic constant (k ₃₃ ) [ K = ½ (k ₁₁ + k ₃₃ )]
And where
e / K is called the flexibility-elasticity ratio.

This rotation angle is half of the switching angle in the flex electric switching element.

The response time (τ) of this electro-optic effect is well approximated by the following formula
τ = [P ₀ / (2 π)] ² · γ / K
Where γ is the effective viscosity coefficient associated with the distortion of the spiral.

The flexure effect is characterized by a fast response time (T _{on +} T _off at 35 ° C.) usually in the range of 1 ms to 10 ms, preferably <5 ms and even better <3 ms. It is further characterized by excellent gray scale capabilities.

There is a critical field (Ec) to unlock the spiral, which can be obtained from
E _c = (π ² / P ₀ ) · [k ₂₂ / (e _{0 ·} De)] ^1/2
among them
k ₂₂ is the torsional elastic constant,
e ₀ is the permittivity of the vacuum, and
De is the dielectric anisotropy of the liquid crystal.

The medium according to the present invention according to the present invention can be oriented in different states with its cholesterol-type phase by methods known to experts, such as surface treatment or electric field. For example, it can be aligned into a planar (Grandjean) state, a focal conic state, or a vertical state.

The term "plane alignment" or orientation of the liquid crystal or liquid crystal raw material in the display unit or on the substrate means that the original liquid crystal groups in the liquid crystal or liquid crystal raw material are oriented substantially parallel to the plane of the unit or substrate, respectively.

The term "vertical alignment" or orientation of a liquid crystal or liquid crystal raw material in a display cell or on a substrate means that the original mesogen groups in the liquid crystal or liquid crystal raw material are substantially oriented perpendicular to the plane of the cell or substrate, respectively.

In the following, the switching between different states of the orientation according to a preferred embodiment of the present invention is exemplarily described in detail.

According to this preferred embodiment, a sample is placed into a unit containing two planar parallel glass plates coated with an electrode layer (such as an ITO layer), and aligned with its cholesterol-type phase into a planar state, where cholesterol The axis of the profile spiral is oriented perpendicular to the cell wall. This state is also called the Grande Jean state, and the structure of the sample that can be observed, for example, in a polarizing microscope, is called the Grande Jean structure. Planar alignment can be achieved, for example, by surface-treating unit walls, for example by rubbing and / or coating with an alignment layer such as polyimide.

The Grande state with high-quality alignment and few defects can be further achieved by heating the sample to an isotropic phase and then cooling it to a temperature close to the opposite nematic-isotropic phase transition to Opposite palm nematics, and the alignment is flowed by slightly pressing the unit.

In a planar state, the sample shows selective reflection of incident light, where the center wavelength of the reflection depends on the spiral spacing and average refractive index of the material.

When an electric field with a frequency of, for example, 10 Hz to 1 kHz and an amplitude of at most 12 V _rms / µm is applied to the electrode, the sample switches to a vertical state in which the helix is untied and the molecules are oriented parallel to the field, that is, perpendicular to The electric field plane. In the vertical state, the sample is transmissive when viewed in normal daylight, and the sample appears black when placed between the orthogonal polarizers.

When the electric field is reduced or removed in the vertical state, the sample adopts a focal quadratic curve structure, in which the molecules exhibit a spiral twist structure, and the spiral axis is oriented perpendicular to the field, that is, parallel to the electrode plane. The focal quadratic curve state can also be achieved by applying only a weak electric field to the sample in its planar state. In the state of the focal quadratic curve, the sample is scattered when viewed in normal daylight and appears bright between the orthogonal polarizers.

The samples of the medium according to the invention exhibit different light transmittances in different states of orientation. Therefore, depending on the intensity of the applied electric field, the individual orientation state and its alignment quality can be controlled by measuring the light transmittance of the sample. It is also possible to determine the electric field strength required to achieve a specific orientation state and the transition between these different states.

In the sample of the medium according to the present invention, the above-mentioned state of the focal quadratic curve is composed of a plurality of disordered birefringent small regions. A uniform alignment structure is achieved by applying an electric field (preferably accompanied by an additional shear unit) that is higher than the field used for the nucleation of the focal quadratic curve structure, where the spiral axis is parallel in the larger, better aligned area On the electrode plane. According to the literature on state-of-the-art palindromic nematic materials, such as P. Rudquist et al., Liq. Cryst. 23 (4), 503 (1997), this structure is also known as the Uniform Lateral Helix (ULH) structure. This structure is needed to characterize the flexural electrical properties of the inventive compounds.

Starting from the ULH structure, the dielectric of the present invention can be flexibly switched by applying an electric field. This rotates the optical axis of the material in the plane of the unit substrate, which results in a change in transmittance when the material is placed between the orthogonal polarizers. The flexure electrical switching of the materials of the present invention is described in further detail above and in the examples.

Starting from the focal quadratic curve structure, it is also possible to obtain a ULH structure by applying an electric field having a high frequency of, for example, 10 kHz to the sample, while slowly cooling from an isotropic phase to a cholesterol-type phase and shearing the unit. The field frequency can be different for different compounds.

In addition to its use in flexural electrical devices, the medium according to the present invention is also suitable for other types of displays and other optical and electro-optical applications, such as optical compensation or polarizing films, color filters, reflective cholesterol, optical rotation ability, and optical Information storage.

Without further description, those skilled in the art can use the above description to make full use of the present invention. Therefore, the following examples should be understood as illustrative only and in no way limit the rest of the invention.

Unless the context clearly indicates otherwise, as used herein, the plural form of a term shall be considered herein to include the singular form, and vice versa.

Throughout this description and the scope of the patent application, the words "comprise" and "contain" and variations of these words, such as "comprising" and "comprises" mean Are referred to as "including but not limited to" and are not intended to (and do not) exclude other components.

Throughout this application, it is understood that the bond angle at the C atom bonded to three adjacent atoms (for example in a C = C or C = O double bond or for example in a benzene ring) is 120 °, and the bond The bond angle to the C atom of two adjacent atoms (e.g., in C≡C or in the C≡N triple bond or in the allyl position C = C = C) is 180 °, unless such angles start with Other ways are limited (for example, as a small ring, such as a part of a 3-atom ring, a 4-atom ring, or a 5-atom ring), although in some cases these angles are not accurately represented in some structural formulas.

It should be understood that variations may be made to the foregoing embodiments of the invention, but they are still within the scope of the invention. Each feature disclosed in this specification, unless stated otherwise, may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

All features disclosed in this specification may be combined in any combination other than the mutually exclusive combination of at least some such features and / or steps. In particular, the preferred features of the invention are applicable to all aspects of the invention and can be used in any combination. Also, features described in non-essential combinations may be used separately (not in combination).

The parameter ranges indicated in this application all include limit values, which include the maximum allowable errors known by experts. The combination of each other indicates that different upper and lower limits of various characteristic ranges yield other preferred ranges.

The total concentration of all compounds in the medium according to this application is 100%. Unless otherwise specified, all concentrations are given in% w / w.

In the above and following examples, unless otherwise indicated, all temperatures are stated in degrees Celsius without correction, and all parts and percentages are by weight.

It is self-evident to those skilled in the art that the LC medium may also include compounds in which, for example, H, N, O, Cl, and F have been replaced by corresponding isotopes.

The following abbreviations are used to describe the liquid crystal phase behavior of the compound: T _{N, I} = clearing point; K = crystalline; N = nematic; N _TB = second nematic or twisted-bent nematic; S or Sm = near Crystal form; Ch = cholesterol type; I = isotropic; Tg = glass transition. The number between the symbols indicates the phase transition temperature in ° C.

In the present application and especially in the following examples, the structure of the liquid crystal compound is represented by an abbreviation (which is also referred to as a "word prefix"). According to the three tables A to C below, the abbreviations can be directly converted into corresponding structures.

All groups C _n H _{2n + 1} , C _m H _{2m + 1} and C _l H _{2l + l are} preferably straight-chain alkyl groups having n, m and l C atoms, respectively, and all groups C _n H _2n , C _m H _2m and C _l H _{2l are} preferably (CH ₂ ) _n , (CH ₂ ) _m and (CH ₂ ) _l , respectively, and -CH = CH- is preferably trans E vinyl group, respectively. Preferably, n, m and l represent integers between 1 and 12.

Table A lists the symbols used for the ring elements, Table B lists the symbols used for the linking groups, and Table C lists the symbols used for the left and right end groups of the molecule.

Table A : Ring Elements


Table B : Linking groups
Table C : End groups

Where n and m are each an integer, and the three dots "..." indicate space for other symbols used in this table.

Examples
Test cells and methods <br/> Usually, a 3 μm-thick cell is filled on a hot plate at a temperature where the flexure electrical mixture is at an isotropic phase. The cell has an anti-parallel friction PI alignment layer on its substrate opposite to each other. .

Prior to filling the cell, phase transitions including clarification point and crystallization behavior are usually measured using differential scanning calorimetry (DSC). In addition, for optical phase variable measurement, a Mettler FP90 hot stage controller connected to the FP82 hot stage is used to control the temperature of the unit. The temperature was raised from ambient temperature at a rate of 5 ° C / minute until the beginning of the isotropic phase was observed. Structural changes were observed via an Olympus BX51 microscope through a cross polarizer, and individual temperatures were recorded.

The wire was then attached to the cell's ITO electrode using indium metal. Fix the unit in a Linkam THMS600 hot stage connected to a Linkam TMS93 hot stage controller. The hot stage was fixed to a rotating stage in an Olympus BX51 microscope.

The cell is heated until the liquid crystal is completely isotropic. The cell is then cooled under the applied electric field until the sample is completely nematic. The drive waveform was supplied by a Tektronix AFG3021B arbitrary function generator, which was sent through a Newtons4th LPA400 power amplifier and then applied to the unit. Response with Thorlabs PDA55 photodiode monitoring unit. The input waveform and optical response were measured using a Tektronix TDS 2024B digital oscilloscope.

In order to measure the flexural electrical response of a material, unless explicitly stated otherwise, changes in the magnitude of the inclination of the optical axis are measured as a function of the increased voltage at 35 ° C. This is achieved by using the following equation:
tan φ = (P ₀ / 2π) (e / K) E
Where φ is the tilt of the optical axis from the original position (that is, when E = 0), E is the applied field, K is the elastic constant (average of K ₁ and K ₃ ), and e is the flexural coefficient (where e = e ₁ + e ₃ ). The applied field was monitored using an HP 34401A multimeter. Use the aforementioned microscope and oscilloscope to measure the tilt angle. An Ocean Optics USB4000 spectrometer attached to a computer was used to measure the undisturbed cholesterol pitch P ₀ . A selective reflection band is obtained and the pitch is determined from the spectral data.

The media shown in the following examples are very suitable for ULH displays. For this purpose, a suitable concentration of a palmitic dopant or dopant must be applied in order to achieve a typical cholesterol pitch of 350 to 275 nm.

Mixture example
Host mixture H-1
The following mixture H1 was prepared. Phase transitions including clearing point and crystallization behavior were determined using DSC.

Mixture example M-1
15% w / w of compound BM-1:

Added to 85% w / w of the host mixture H-1.

The resulting mixture M-1 was homogenized and filled into a test cell as described above.

Measurements were performed on switching performance, T _NI (clarification point), e / K (flexible elastic constant), and N _TB (transition temperature to the second nematic phase or nematic twisted and bent phase) and the results are summarized in the table below. in.

Mixture example M-2
15% w / w of compound BM-2

Added to 85% w / w of the host mixture H-1.

The resulting mixture M-2 was homogenized and filled into a test cell as described above.

Measurements regarding switching efficiency, clarification point, flexible elastic constant, and N _TB transition temperature were performed and the results are summarized in the table below.

Mixture example M-3
15% w / w of compound BM-3

Added to 85% w / w of the host mixture H-1.

The resulting mixture M-3 was homogenized and filled into a test cell as described above.

Measurements regarding switching efficiency, clarification point, flexible elastic constant, and N _TB transition temperature were performed and the results are summarized in the table below.

Mixture example M-4
15% w / w of compound BM-4

Added to 85% w / w of the host mixture H-1.

The resulting mixture M-4 was homogenized and filled into a test cell as described above.

Measurements regarding switching efficiency, clarification point, flexible elastic constant, and N _TB transition temperature were performed and the results are summarized in the table below.

Claims (18)

A compound of formula I, R ¹¹ -A ¹¹ (-Z ¹¹ -A ^12- ) _p -X ¹¹ -Sp ¹¹ -X ^12- (A ¹³ -Z ^12- ) _q A ¹⁴ -R ¹² I wherein R ¹¹ represents NO ₂ , NCO or NCS R ¹² represents F, Cl, CN, NO ₂ , NCO, NCS or a straight or branched chain alkyl group, which may be unsubstituted, mono-substituted with halogen or CN Or more substituted and in which one or more non-adjacent and non-terminal CH ₂ groups can be replaced independently of each other by the following groups: -O-, -S-, -NH-, -N ( CH ₃ )-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-CO-, -CO-S-, -CH = CH-, -CH = CF-,- CF = CF- or -C≡C-, the substitution method is such that the oxygen atoms are not directly connected to each other, and A ¹¹ to A ¹⁴ each independently represent 1,4-phenylene, and one or more of them CH groups can be replaced by N; trans-1,4-cyclohexyl, and one or two non-adjacent CH ₂ groups can be replaced by O and / or S; 1,4-cyclohexyl; naphthalene- 2,6-diyl; decalin-2,6-diyl; 1,2,3,4-tetrahydro-naphthalene-2,6-diyl, all of which may be unsubstituted, F, Cl, CN or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl single , Disubstituted, trisubstituted or tetra-substituted, wherein one or more H atoms may be substituted with F or Cl, Z ¹¹ and Z ¹² at each occurrence are each independently a single bond, -COO -, - OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -OCF _2- , -CF ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ CF ₂ -, -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH-, or -C≡C-, these groups pass one or more F, S as appropriate And / or Si substitution, p and q are each and independently 0, 1, 2, 3, or 4, and Sp ¹¹ is a spacer group that contains 1, 3, or 5 to 40 C atoms, one or more of which are not Adjacent and non-terminal CH ₂ groups can also be replaced by the following groups: -O-, -S-, -NH-, -N (CH ₃ )-, -CO-, -O-CO-, -S- CO-, -O-COO-, -CO-S-, -CO-O-, -CF _2- , -CF ₂ O-, -OCF _2- , -C (OH)-, -CH (alkyl) -, -CH (alkenyl)-, -CH (alkoxy)-, -CH (oxealkyl)-, -CH = CH- or -C≡C-, however the substitution method is such that there are no two O's Atoms are adjacent to each other and no two groups selected from -O-CO-, -S-CO-, -O-COO-, -CO-S-, -CO-O-, and -CH = CH- are in phase with each other Ortho, X ¹¹ and X ¹² are independently selected from a single bond, -CO-O-, -O-CO-, -O -COO -, - O -, - CH = CH -, - C≡C -, - CF 2 -O -, - O-CF 2 -, - CF 2 -CF 2 -, - CH 2 -O -, - O-CH _2- , -CO-S-, -S-CO-, -CS-S-, -S-CS-, -S-CSS-, and -S-, where -X ¹¹ -Sp ¹ -X ^{In 12-} , two O atoms, two -CH = CH- groups, and two selected from -O-CO-, -S-CO-, -O-COO-, -CO-S-, and -CO- The O- groups are not directly connected to each other. The compound as claimed in claim 1, wherein the group -A ¹¹ (-Z ¹¹ -A ^12- ) _p -or-(A ¹³ -Z ^12- ) _q A ¹⁴ -is selected from the following formula: Where CHex is 1,4-cyclohexyl, Phe is 1,4-phenyl, and PheL is 1,4-phenyl, which has one, two or three fluorine atoms, and one or two Cl atoms Or substituted by a Cl atom and an F atom, and Z has one of the meanings of Z ¹¹ as given under Partial Formula II, and if two are present, at least one is selected from -C≡C-, -C = C-, -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O-, -OCF _2- , or -CF ₂ O-. For example, the compound of claim 1 or 2, wherein Sp ¹¹ represents-(CH ₂ ) _n- , where n is an integer from 1 to 15, and one or more -CH ₂ -groups may be replaced by -CO-. The requested item according to any one of compound 1-3, wherein -X ¹¹ -Sp ¹¹ -X ¹² - represents ^{-Sp 11 -, - Sp 11 -O} -, - Sp 11 -CO-O -, - Sp 11 - O-CO -, - CO- O-Sp 11, -O-CO-Sp 11, -O-Sp 11 -, - O-Sp 11 -CO-O -, - O-Sp 11 -O-CO-, -O-CO-Sp ¹¹ -O-, -O-CO-Sp ¹¹ -O-CO-, -CO-O-Sp ¹¹ -O- or -CO-O-Sp ¹¹ -CO-O-, however restricted Provided that in -X ¹¹ -Sp ¹¹ -X ^12- , no two O atoms are adjacent to each other, no two -CH = CH- groups are adjacent to each other and no two are selected from -O-CO-,- The groups of S-CO-, -O-COO-, -CO-S-, -CO-O-, and -CH = CH- are adjacent to each other. Use of a compound of formula I as claimed in claim 1 in a liquid crystal medium. An LC medium comprising one or more compounds of formula I as claimed in any one of claims 1 to 4. If the LC medium of claim 6 comprises one or more compounds of formula II, R ²¹ -A ²¹ -A ^22- (CH ₂ ) _a -A ²³ -A ²⁴ -R ²² II wherein R ²¹ and R ²² are each and Independently represent H, F, Cl, CN or a linear or branched alkyl group, which may be unsubstituted, mono- or poly-substituted with halogen or CN, one or more different The ortho CH ₂ groups may also be replaced independently of each other by the following groups at each occurrence: -O-, -S-, -NH-, -N (CH ₃ )-, -CO-, -COO-,- OCO-, -O-CO-O-, -S-CO-, -CO-S-, -CH = CH-, -CH = CF-, -CF = CF-, or -C≡C-, the replacement method is So that the oxygen atoms are not directly connected to each other, A ²¹ to A ²⁴ each and each independently represent an aryl group, a heteroaryl group, an alicyclic group, and a heterocyclic group, and a represents an integer of 1 to 15. If the LC medium of claim 6 or 7 comprises one or more compounds of formula III, R ³¹ -A ³¹ -A ^32- (A ³³ ) _b -Z ^31- (CH ₂ ) _c -Z ³² -A ^34- A ³⁵ -A ³⁶ -R ³² III wherein R ³¹ and R ³² each and independently of one another have the meaning given for R ²¹ under formula II, and A ³¹ to A ³⁶ each and independently of each other have One of the meanings given for A ²¹ under Formula II, Z ³¹ and Z ³² each and each independently represent -COO-, -OCO-, -O-CO-O-, -OCH ₂ -, -CH ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH- or -C≡C-, these groups are optionally substituted with one or more F, S and / or Si, c represents Integer from 1 to 15 and b represents 0 or 1. The LC medium of any one of claims 6 to 8, comprising one or more compounds of formula IV, R ⁴¹ -A ⁴¹ -A ⁴² -Z ^41- (CH ₂ ) _d -Z ⁴² -A ⁴³ -A ⁴⁴ -R ⁴² IV wherein R ⁴¹ and R ⁴² each and independently of one another have the meaning given for R ²¹ under Formula II, and A ⁴¹ to A ⁴⁴ each and independently of one another have the same formula as under Formula II One of the meanings given by A ²¹ , Z ⁴¹ and Z ⁴² are each independently -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O -, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH-, or -C≡C-, these groups are optionally substituted with one or more F, S, and / or Si, and d represents an integer from 1 to 15. The LC medium of any one of claims 6 to 9, comprising one or more compounds of formula V, R ⁵¹ -A ⁵¹ -Z ^51- (CH ₂ ) _e -Z ⁵² -A ^52- (A ⁵³ ) _f -R ⁵² V wherein R ⁵¹ and R ⁵² each and independently of one another have the meaning given for R ²¹ under Formula II, and A ⁵¹ to A ⁵³ each and independently of each other have a formula such as One of the meanings given by A ²¹ , Z ⁵¹ and Z ⁵² are each independently -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O -, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH- or -C≡C-, these groups are optionally substituted with one or more F, S and / or Si, f represents 0 or 1, e represents An integer from 1 to 15. The LC medium of any one of claims 6 to 10, which comprises one or more compounds of formula VI, R ⁶¹ -A ⁶¹ -A ^62- (CH ₂ ) _g -Z ⁶¹ -A ⁶³ -A ^64- (A ⁶⁵ ) _h- R ⁶² VI wherein R ⁶¹ and R ⁶² each have one of the meanings given for R ²¹ and R ²² under formula II, and A ⁶¹ to A ^{64 have} each independently One of the meanings given for A ²¹ under the formula II, Z ⁶¹ represents -O-, -COO-, -OCO-, -O-CO-O-, -OCH _2- , -CH ₂ O, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ -O-, -O-CF _2- , -CF ₂ CF _2- , -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH- or -C≡C-, these groups are optionally substituted with one or more F, S and / or Si, h represents 0 or 1, and g represents 1 Integer to 15. The LC medium of any one of claims 6 to 11, comprising one or more compounds of formula VII, R ⁷¹ -A ⁷¹ -Z ⁷¹ -A ^72- (Z ⁷² -A ⁷³ ) _j- (CH ₂ ) _k ^{- (A 74 -Z 73 -)} l -A 75 -Z 74 -A 76 -R 72 VII wherein R ⁷¹ and R ⁷² are each and independently have one of the following formula II above in the meaning given for R ²¹ in Wherein, A ⁷¹ to A ⁷⁶ each and independently have one of the meanings given above for A ²¹ under Formula II, and Z ⁷¹ to Z ⁷⁴ each independently represent -COO-, -OCO-, -O -CO-O-, -OCH _2- , -CH ₂ O-, -OCF _2- , -CF ₂ O-, -CH ₂ CH ₂ -,-(CH ₂ ) _4- , -CF ₂ CF _2- ,, -CH = CH-, -CF = CF-, -CH = CH-COO-, -OCO-CH = CH-, or -C≡C-, these groups are optionally subject to one or more F, S, and / It is substituted with Si, or represents a single bond, with the restriction that at least one of Z ⁷¹ to Z ⁷⁴ is not a single bond, j represents an integer from 1 to 15, and i and k represent 0 or 1. The LC medium of any one of claims 6 to 12, which comprises one or more palmar dopants. If the LC medium of any one of claims 6 to 13, comprising one or more nematic LC compounds, the nematic LC compounds are selected from the compounds of formulas X-1 to X-4, Wherein R ^2A represents H, an alkyl group, alkenyl group or alkoxy group having 1 to 15 C atoms, and in addition, one or more CH ₂ groups in these groups can be independently replaced with each other by the following groups : -C≡C-, -CF ₂ O-, -CH = CH-, , , -O-, -CO-O-, or -O-CO-, the substitution method is such that O atoms are not directly connected to each other, and one or more H atoms can be replaced by halogen, and L ¹ and L ² are independent of each other Ground represents F, Cl, CF ₃ or CHF ₂ , and Z ² and Z ^{2 '} each independently represent a single bond, -CH ₂ CH _2- , -CH = CH-, -C≡C-, -CF ₂ O- , -OCF _2- , -CH ₂ O-, -OCH _2- , -COO-, -OCO-, -C ₂ F _4- , -CF = CF- or -CH = CHCH ₂ O-, p represents 0, 1 or 2, q represents 0 or 1, (O) C _v H _{2v + 1} represents OC _v H _{2v + 1} or C _v H _{2v + 1} , and v represents 1 to 6. A method for preparing an LC medium according to any one of claims 6 to 14, comprising the step of mixing one or more compounds of formula I, wherein at least one compound is selected from the compounds of formulas II to X. A use of an LC medium according to any one of claims 6 to 14 in an electro-optical device. An electro-optical device comprising a medium according to any one of claims 6 to 14. The electro-optical device according to claim 17, wherein the electro-optical device is a flexure electrical device.