JP2004115808A - Method for designing liquid crystal medium dispersion, liquid crystal medium and electrooptic display comprising the medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal medium having no defect of mediums of conventional technologies or having the defect of at most much decreased level. <P>SOLUTION: The method for designing liquid crystal dispersion comprises selecting each compound so as to have ≥0.50 relative birefringence dispersion (δ<SB>Δn</SB>/Δn<SB>mix</SB>) of each applied compound (Δn<SB>j</SB>) and a nematic liquid crystal medium is obtained by the method. And, especially, a nematic liquid crystal medium comprising (a) an ingredient A comprising a compound having low birefringence (Δn) of ≤0.080, voluntarily, (b) an ingredient B having medium birefringence of 0.081-0.149 and (c) an ingredient C having a high birefringence of ≥0.150 is provided. And use of the medium in a liquid crystal display, a liquid crystal display comprising the medium and, especially, a display addressed by a matrix of an active switching element are provided. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to liquid crystal displays, especially active matrix addressed liquid crystal displays (AMD or AMLCD), especially those using an active matrix including thin film transistors (TFTs) or varistors. Furthermore, the present application relates to a liquid crystal medium for use in this type of display.

Ａ This type of AMD can use various active electronic switching elements. The most extensive are displays using three-pole switching elements. These are also preferred in the present invention. Examples of a triode switching element of this type are MOS (metal oxide silicon) transistors or the aforementioned TFTs or varistors. In the TFT, various semiconductor materials, mainly silicon, or cadmium selenide are used. In particular, polycrystalline silicon or amorphous silicon is used. For a three-pole electronic switching element, a matrix of a two-pole switching element, for example a MIM (metal insulator metal) diode, a ring diode or a "back to back" diode is also used in AMD. Can be. However, as also described in more detail below, they are generally not preferred due to the worse electro-optical properties achieved by AMD.

液晶 The liquid crystal used as a dielectric in this type of liquid crystal display changes its optical characteristics reversibly when a voltage is applied. Electro-optical displays using liquid crystals as the medium are known to those skilled in the art. These liquid crystal displays use various electro-optical effects.

The most widespread conventional displays use the TN effect (twisted nematic, having a nematic structure twisted about 90 °), the STN effect (super twisted nematic) or the SBE effect (super twisted birefringent effect). In these and similar electro-optical effects, a liquid crystal medium of positive dielectric anisotropy (Δε) is used.

In general, the operating voltage in displays, including displays that make use of these effects, must be as low as possible, and are therefore generally composed mainly of dielectrically positive liquid crystal compounds and at most relatively small / A liquid crystal medium having a relatively large dielectric anisotropy, comprising a low proportion of a dielectrically neutral compound is used.

Other electro-optics using a liquid crystal medium with a negative dielectric anisotropy, in contrast to the above-mentioned conventional displays using the aforementioned electro-optical effect, which require a liquid crystal medium with a positive dielectric anisotropy There are kinetic effects such as the ECB effect (electrically controlled birefringence) and its subordinate forms DAP (alignment phase deformation), VAN (vertical alignment nematic) and CSH (color hyperhomeotropic). These are likewise the subject of the present application.

The IPS (In-Plane Switching) effect, which has recently been used to an increased extent, is to use dyes in either dielectrically positive or dielectrically negative media, depending on the display mode used. Possible, dielectrically positive and dielectrically negative liquid crystal media, similar to a “guest / host” display, can be used together. Even in the case of the liquid crystal display described in this paragraph, the use of a dielectrically negative liquid crystal medium is also the subject of the present application.

Another highly promising liquid crystal display type is the so-called "axisymmetric microdomain" (abbreviated as ASM) display, which is preferably a plasma array (plasma addressed liquid crystal display or PA @ LCD). Is addressed by This display is also the subject of the present application.

The liquid-crystal media used in the above-mentioned liquid-crystal displays and in all liquid-crystal displays using similar effects are generally mainly, and in most cases even more very substantially, liquid-crystal compounds having a corresponding dielectric anisotropy. That is, it comprises a compound having a positive dielectric anisotropy in the case of a dielectrically positive medium and a compound having a negative dielectric anisotropy in the case of a dielectrically negative medium.

In order to achieve sufficiently good contrast, the optical delay, the product of the birefringence of the liquid crystal material (Δn) and the thickness of the liquid crystal layer (d), matches the particular electro-optical mode used. Must have a value.
The birefringence of a liquid crystal material is relatively highly dependent on the wavelength of the light used. This effect is also known as birefringence dispersion. Because of this effect, only certain individual birefringence values that are preferred for electro-optic display modes can be set at a single wavelength.

式中：λは、波長であり、
Δｎ（λ）は、波長λにおける複屈折であり、
Δｎ（∞）は、無限大波長における複屈折であり、
ＡおよびＣは、定数である、
である。 A typical dispersion of a liquid crystal mixture is described in, for example, Non-Patent Document 1. At relatively short wavelengths, the birefringence increases significantly, while at relatively long wavelengths it approaches a certain limit. A broad form of the description of the wavelength dependence of birefringence is the expansion of the polynomial according to the wavenumber, ie the square of the inverse wavelength, Cauchy equation, equation (1):

Where: λ is the wavelength;
Δn (λ) is the birefringence at wavelength λ,
Δn (∞) is the birefringence at infinite wavelength,
A and C are constants,
It is.

用途 Some applications require some birefringence dispersion of the liquid crystal material. This is the case, for example, in IPS displays. In these displays, the undesirable color effects that occur at various specific viewing angles generally depend on the birefringence chromatic dispersion of the liquid crystal material used. Even when the display uses a compensating layer, as for example in many monitor or TV applications, the dispersion of the liquid crystal material is very essential for viewing angle dependence.

The known liquid-crystal mixtures do not fulfill the requirements or only to an insufficient extent.
Accordingly, there has been a great demand for liquid crystal media that does not have the drawbacks of the media from the prior art or at least to a significantly reduced extent. And there is a request.

Wu, T.S. et al., SPIE 684, "Liquid Crystal and Spatial Light Modulator Materials", 1986, 69-76.

The present invention was based on the object of providing a liquid crystal material having a certain birefringence dispersion and providing a method for obtaining such a material.

Virtually all liquid crystal materials used in liquid crystal displays are not individual compounds, but instead are mixtures of a plurality of individual compounds. The inventors of the present invention have found that the birefringence dispersion of the liquid crystal mixture can be influenced by a corresponding choice of the compound used, and thus can be selected in a targeted manner.

The present application also relates to a method for setting the dispersion of a liquid crystal medium, wherein the individual compounds have a relative birefringence dispersion (δ _Δn / Δn _mix ) of the individual compounds (Δn _i ) used of 0.50 or The method is characterized in that it is selected to be more than this.
The birefringence of the liquid crystal mixture is determined by the birefringence value of the compound used. For a rough approximation, the birefringence of the mixture is obtained as the arithmetic mean of the birefringence values of all the individual compounds used, weighted at the respective molar fractions.

If, in order to obtain a liquid crystal mixture having a given birefringence, individual compounds, all having a birefringence value relatively close to the value of the mixture, are mixed with one another, the birefringence dispersion of the mixture will be relatively high. Low. However, in contrast, when using compounds whose birefringence values differ greatly from those of the mixture, the resulting mixture has a relatively high dispersion. Mixtures having a variance between these two extremes are obtained by using compounds having birefringence values that differ to a greater extent from the values of the mixture at corresponding proportions of the concentration of the compound having average birefringence. ,can get.

式中：Δｎ_ｉは、化合物ｉの複屈折であり、
Δｎ_ｍｉｘは、混合物の複屈折である。 A criterion that can be used to characterize the degree of deviation of the birefringence values of the individual compounds from the birefringence values of the mixture is the variance (σ _Δn ) according to equation (2).

Wherein: [Delta] n _i is the birefringence of the compounds i,
Δn _mix is the birefringence of the mixture.

Here, _too , the relative values σ _Δn / Δn _mix are generally suitable for comparing different mixtures. This is especially true if the mixtures to be compared have significantly different birefringence values.
The liquid crystal mixture according to the invention preferably comprises a component A consisting of a compound having a low birefringence. The birefringence value Δn of the compound of this component is in the range of 0.080 or less, preferably 0.070 or less, and particularly preferably 0.06 or less.

The liquid crystal mixture according to the invention preferably comprises a component B consisting of a compound having a moderate birefringence, having a value in the range from 0.081 to 0.149, preferably from 0.090 to 0.140.
The liquid-crystal mixtures according to the invention preferably comprise components C having a high birefringence having a value of 0.150 or higher, preferably 0.160 or higher and particularly preferably 0.170 or higher. including.

The liquid crystal mixtures according to the invention preferably have a birefringence in the range from 0.070 to 0.110, particularly preferably from 0.075 to 0.100 and very particularly preferably from 0.080 to 0.095.

Component A has the following -cyclohexane ring and phenyl ring;
-Having two cyclohexane rings,
Having three cyclohexane rings,
Wherein one or two or more of the compounds, preferably one or two or more non-adjacent in one cyclohexane ring, preferably two CH ₂ groups is replaced by O Preferably comprise, in particular consist essentially of, particularly preferably consist essentially completely of, and very particularly consist essentially of, these compounds.

Component B has the following -2 cyclohexane rings and one phenyl ring, where these compounds can be either dielectrically neutral or dielectrically positive,
It has one cyclohexane ring and two phenyl rings, which preferably comprise, in particular predominantly, and especially preferably substantially, compounds selected from the group consisting of dielectrically positive compounds. They consist entirely of these, very particularly virtually exclusively of them.

Component C preferably has two phenyl rings directly bonded to each other, preferably has the following -2 phenyl rings,
-Has two phenyl rings and one cyclohexane ring, which is dielectrically neutral,
A compound selected from the group consisting of -2 compounds having two phenyl rings and two cyclohexane rings, preferably consisting essentially of these, particularly preferably consisting essentially completely of these, very particularly factually. It consists exclusively of these.

式中、
Ｒ^１１およびＲ^１２は、各々、互いに独立して、１〜１５個、好ましくは１〜７個の炭素原子を有するアルキルであり、これは、随意に、少なくともハロゲン、好ましくはＦにより一置換されており、ここで、１つまたは２つ以上のＣＨ_２基は、各々の場合において、互いに独立して、−Ｏ−、−Ｓ−、−ＣＨ＝ＣＨ−、

−ＣＯ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−または−Ｏ−ＣＯ−Ｏ−により、Ｏ原子が互いに直接結合しないように置換されていることができ、Ｒ^１１およびＲ^１２の一方は、あるいはまた、ＨまたはＦであり、好ましくは、Ｒ^１１は、アルキルであり、Ｒ^１２は、アルキル、アルコキシ、アルケニルまたはＣＦ_３であり、 Component A has the formula I and II

Where:
R ¹¹ and R ¹² are each, independently of one another, alkyl having 1 to 15, preferably 1 to 7 carbon atoms, which is optionally monosubstituted by at least halogen, preferably by F. Wherein one or more CH ₂ groups are in each case independently of one another —O—, —S—, —CH ＝ CH—,

-CO -, - CO-O - , - O-CO- or by -O-CO-O-, it can the O atom is substituted so as not linked directly to one ^another, one of ^{R 11} and ^{R 12} Or alternatively H or F, preferably R ¹¹ is alkyl and R ¹² is alkyl, alkoxy, alkenyl or CF ₃ ;

Z ¹¹ and ^{Z 12} are each, independently of one _{another, -CH 2 -CH 2 -, -} CF 2 -CF 2 -, - CF 2 -CH 2 -, - CH 2 -CF 2 -, - CH = CH —, —CF ＝ CF—, —CF ＝ CH—, —CH ＝ CF—, —C≡C—, —COO—, —OCO—, —CH ₂ O—, —OCH ₂ —, —CF ₂ O— _{, -OCF 2 -, - (CH} 2) 4 - or a single bond,
n is 0, 1 or 2;
and,

R ²¹ , R ²² and Z ² are each as defined for the corresponding parameters R ¹¹ , R ¹² and Z ¹¹ in formula I, wherein R ²² is alternatively F, Cl, —CF ₃ , —OCF ₂ H or —OCF ₃ ,
One or two non-adjacent, preferably two, CH ₂ groups in the cyclohexane ring in formulas I and II may be substituted by an O atom, and the phenyl ring in formula II may be one or two. F may be substituted, preferably in the ortho position relative to the group R ²² ,
And preferably consists essentially of these, particularly preferably consists essentially completely of these, very particularly virtually exclusively of these.

Component A preferably comprises, in particular predominantly consists of, particularly preferably consists essentially completely of these, compounds selected from the group consisting of the compounds of the formulas I and II, very particularly virtually exclusively Consisting of these, where
R ¹¹ is n-alkoxy having 1 to 7 carbon atoms,
R ¹² is n-alkoxy having 1 to 7 carbon atoms, alkenyloxy having 2 to 7 carbon atoms or CF ₃ ,
Z ¹¹ and Z ¹² are each independently of the other —CH ₂ —CH ₂ —, —CH ₂ O—, —OCH ₂ —, —CF ₂ O—, —OCF ₂ —, —COO—, — ( CH ₂ ) ₄ — or a single bond, preferably —CH ₂ —CH ₂ —, —CF ₂ O—, —COO— or a single bond;

n is 0, 1 or 2, preferably 0 or 1,
R ²¹ is n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ²² is, n- alkoxy having 1 to 7 carbon atoms, alkenyloxy of 2-7 carbon atoms, n- alkyl or F having 1-7 carbon atoms, Cl, _-CF 3, —OCF ₂ H or —OCF ₃ ,
Z ² is as defined for Z ¹¹ , and is preferably a single bond.

で表される化合物からなる群から選択された化合物を好ましくは含み、特に主にこれらからなり、特に好ましくは実質的に完全にこれらからなり、極めて特に事実上専らこれらからなり、ここで、
Ｒ^３１およびＲ^３２は、各々、互いに独立して、式ＩＩ中の対応するパラメーターＲ^２１およびＲ^２２について前に定義した通りであり、
Ｒ^３１は、好ましくは１〜７個の炭素原子を有するｎ−アルキル、１〜７個の炭素原子を有するｎ−アルコキシまたは２〜７個の炭素原子を有するアルケニルオキシであり、
Ｒ^３２は、好ましくは、１〜７個の炭素原子を有するｎ−アルキルもしくはｎ−アルコキシ、２〜７個の炭素原子を有するアルコキシアルキルもしくはアルケニルオキシ、ハロゲンまたは１〜３個の炭素原子を有するフッ素化アルキルもしくはアルコキシ、または２もしくは３個の炭素原子を有するアルケニルもしくはアルケニルオキシ、好ましくはＦ、Ｃｌまたは−ＯＣＦ_３、特に好ましくはＦまたは−ＯＣＦ_３、極めて特に好ましくはＦであり、 Component B has the formula III and IV

Preferably comprises, in particular mainly consists of, particularly preferably consists essentially completely of these, very particularly virtually exclusively of these, in which the compounds selected from the group consisting of the compounds represented by
R ³¹ and R ³² are each, independently of one another, as defined above for the corresponding parameters R ²¹ and R ²² in formula II;
R ³¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ³² is preferably n-alkyl or n-alkoxy having 1 to 7 carbon atoms, alkoxyalkyl or alkenyloxy having 2 to 7 carbon atoms, halogen or having 1 to 3 carbon atoms fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, are very particularly preferably F,

Z ³¹ and Z ³² are each, independently of one another, as defined for Z ^{11 in} formula II;
L ³¹ and L ³² are each, independently of one another, H or F;
R ⁴¹ and R ⁴² are each, independently of one another, as defined above for the corresponding parameters R ²¹ and R ²² in formula II;
R ⁴¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ⁴² is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms, alkenyloxy having 2 to 7 carbon atoms, halogen or 1 to 3 carbon atoms. having carbon atoms, fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, very Particularly preferred is F,

L ⁴¹ and L ⁴² are each, independently of one another, H or F;
Z ⁴¹ and Z ⁴² are each independently of the other as defined for Z ^{11 in} formula II, and the central phenyl ring of formula IV is mono-, di- or polysubstituted by an F atom, preferably Can be mono- or disubstituted.

式中、
Ｒ^５１およびＲ^５２は、各々、互いに独立して、式ＩＩにおける対応するパラメーターＲ^２１およびＲ^２２について前に定義した通りであり、
Ｒ^５１は、好ましくは、１〜７個の炭素原子を有するｎ−アルキル、１〜７個の炭素原子を有するｎ−アルコキシまたは２〜７個の炭素原子を有するアルケニルオキシであり、
Ｒ^５２は、好ましくは、１〜７個の炭素原子を有するｎ−アルキルまたはｎ−アルコキシ、２〜７個の炭素原子を有するアルコキシアルキルまたはアルケニルオキシ、ハロゲンまたは１〜３個の炭素原子を有するフッ素化されたアルキルもしくはアルコキシ、または２もしくは３個の炭素原子を有するアルケニルもしくはアルケニルオキシ、好ましくはＦ、Ｃｌまたは−ＯＣＦ_３、特に好ましくはＦまたは−ＯＣＦ_３、極めて特に好ましくはＦであり、 Component C has the formulas V-VIII

Where:
R ⁵¹ and R ⁵² are each independently of the other as previously defined for the corresponding parameters R ²¹ and R ²² in Formula II;
R ⁵¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ⁵² is preferably n-alkyl or n-alkoxy having 1 to 7 carbon atoms, alkoxyalkyl or alkenyloxy having 2 to 7 carbon atoms, halogen or having 1 to 3 carbon atoms fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, are very particularly preferably F,

Z ⁵¹ and Z ⁵² are each, independently of one another, as defined for Z ^{11 in} formula II;
m is 0 or 1, preferably 1,
R ⁶¹ and R ⁶² are each, independently of one another, as defined above for the corresponding parameters R ²¹ and R ²² in formula II;
R ⁶¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ⁶² is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms, alkenyloxy having 2 to 7 carbon atoms, halogen or 1 to 3 having carbon atoms, fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, very Particularly preferred is F,
Z ⁶¹ , Z ⁶² and Z ⁶³ are each independently of the other as defined for Z ^{11 in} formula II, preferably each is independently of each other —CH ₂ —CH ₂ —, —CF _{2 -O -, - O-CF} 2 -, - a CO-O- or a single bond,
and

o is 0 or 1;
R ⁷¹ and R ⁷² are each, independently of one another, as defined above for the corresponding parameters R ²¹ and R ²² in formula II;
R ⁷¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ⁷² is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms, alkenyloxy having 2 to 7 carbon atoms, halogen or 1 to 3 having carbon atoms, fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, very Particularly preferred is F,
Z ⁷¹ , Z ⁷² and Z ⁷³ are each, independently of one another, as defined for Z ^{11 in} formula II, preferably each independently of one another, —CF ₂ O—, —O—CF _2- , -CO-O- or a single bond, particularly preferably a single bond,

R ⁸¹ and R ⁸² are each, independently of one another, as defined above for the corresponding parameters R ²¹ and R ²² in formula II;
R ⁸¹ is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms or alkenyloxy having 2 to 7 carbon atoms,
R ⁸² is preferably n-alkyl having 1 to 7 carbon atoms, n-alkoxy having 1 to 7 carbon atoms, alkenyloxy having 2 to 7 carbon atoms, halogen or 1 to 3 having carbon atoms, fluorinated alkyl or alkoxy or alkenyl or alkenyloxy having 2 or 3 carbon atoms, preferably F, Cl or -OCF _3, particularly preferably F or -OCF _3, very Particularly preferred is F,
Z ⁸¹ , Z ⁸² and Z ⁸³ are each independently of the other as defined for Z ^{11 in} formula II, preferably, each independently of the other are —CF ₂ O—, —O—CF _2- , -CO-O- or a single bond, particularly preferably a single bond, and the phenyl rings in formulas V to VIII are each, independently of one another, mono-, di- or polysubstituted by an F atom, Preferably it is mono- or disubstituted, wherein the compounds of the formula IV are excluded in the formula VI
And preferably comprises one or more compounds selected from the group consisting of the compounds represented by the following, particularly preferably consists essentially of these, particularly preferably substantially completely, and very particularly virtually exclusively these Consists of

式中、
Ｒ^１１およびＲ^１２は、各々、互いに独立して、式Ｉ中に前に定義した通りであり、好ましくは、アルキル、アルケニル、アルコキシまたは−ＣＦ_３である、
で表される化合物からなる群から選択された１種または２種以上の化合物を好ましくは含み、特に主にこれらからなり、特に好ましくは実質的に完全にこれらからなり、極めて特に好ましくは事実上完全にこれらからなる。 Examples of compounds which are preferred components of components A, B and C are shown below.
Component A has the formulas I-1 to I-6 and II-1, preferably I-1 to I-4, I-6 and II-1, particularly preferably I-1, I-2 and II-1.

Where:
R ¹¹ and R ¹² are each, independently of one another, as previously defined in formula I, and are preferably alkyl, alkenyl, alkoxy or —CF ₃ ;
Preferably comprises one or more compounds selected from the group consisting of the compounds represented by the following, in particular mainly consisting of, particularly preferably substantially completely, very particularly preferably virtually Consists entirely of these.

Component B has the formula III-1 to III-9 and IV-1 to IV-12

式中、
Ｒ^３１、Ｒ^３２およびＬ^３１は、各々、互いに独立して、式ＩＩＩについて前に定義した通りであり、Ｒ^３１は、好ましくは、アルキルまたはアルケニルであり、Ｒ^３２は、好ましくはＦ、Ｃｌまたは−ＯＣＦ_３、特に好ましくはＦまたは−ＯＣＦ_３であり、式ＩＩＩ−１において、あるいはまた、アルキルまたはアルケニルであり、Ｒ^３２がＦである場合には、Ｌ^３１は、好ましくはＦであり、Ｒ^３２が−ＯＣＦ_３である場合には、Ｌ^３１は、好ましくはＨであり、

Where:
R ³¹ , R ³² and L ³¹ are each, independently of one another, as defined above for formula III, R ³¹ is preferably alkyl or alkenyl, and R ³² is preferably F, Cl Or —OCF ₃ , particularly preferably F or —OCF ₃ , in formula III-1, or alternatively, when it is alkyl or alkenyl and R ³² is F, L ³¹ is preferably F , R ³² is —OCF ₃ , L ³¹ is preferably H;

式中、
Ｒ^４１、Ｒ^４２およびＬ^４１は、各々、互いに独立して、式ＩＶについて前に定義した通りであり、Ｒ^４１は、好ましくはアルキルまたはアルケニルであり、Ｒ^４２は、好ましくはＦ、Ｃｌまたは−ＯＣＦ_３、特に好ましくはＦまたは−ＯＣＦ_３であり、Ｒ^３２がＦである場合には、Ｌ^３１は、好ましくはＦであり、Ｒ^３２が−ＯＣＦ_３である場合には、Ｌ^３１は、好ましくはＨである、
で表される化合物からなる群から選択された１種または２種以上の化合物を好ましくは含み、特に主にこれらからなり、特に好ましくは実質的に完全にこれらからなり、極めて特に好ましくは事実上完全にこれらからなる。

Where:
R ⁴¹ , R ⁴² and L ⁴¹ are each, independently of one another, as defined above for formula IV, R ⁴¹ is preferably alkyl or alkenyl, and R ⁴² is preferably F, Cl or —OCF ₃ , particularly preferably F or —OCF ₃ , when R ³² is F, L ³¹ is preferably F, and when R ³² is —OCF ₃ , L ³¹ is , Preferably H,
Preferably comprises one or more compounds selected from the group consisting of the compounds represented by the following, in particular mainly consisting of, particularly preferably substantially completely, very particularly preferably virtually Consists entirely of these.

式中、パラメーターは、式Ｖの下に前に定義した通りであり、式中のフェニル環は、各々、互いに独立して、Ｆ原子により一置換、二置換または多置換、好ましくは一置換または二置換されていることができ、 Component C has the formulas V-1 to V-3, VI-1 to VI-3, VII-1 and VIII-1 to VIII-3.

Wherein the parameters are as previously defined under formula V, wherein the phenyl rings are each, independently of one another, mono-, di- or polysubstituted, preferably mono- or disubstituted by an F atom. Can be disubstituted,

式中、パラメーターは、式ＶＩの下に前に定義した通りであり、式中のフェニル環は、各々、互いに独立して、Ｆ原子により一置換、二置換または多置換、好ましくは一置換または二置換されていることができ、

Wherein the parameters are as defined above under formula VI, wherein the phenyl rings are each independently of one another mono-, di- or polysubstituted, preferably mono- or disubstituted by an F atom. Can be disubstituted,

式中、パラメーターは、式ＶＩＩの下に前に定義した通りであり、式中のフェニル環は、各々、互いに独立して、Ｆ原子により一置換、二置換または多置換、好ましくは一置換または二置換されていることができ、

Wherein the parameters are as defined above under formula VII, wherein the phenyl rings are each independently of one another mono-, di- or polysubstituted, preferably mono- or polysubstituted by F atoms. Can be disubstituted,

式中、パラメーターは、式ＶＩＩＩの下に前に定義した通りであり、式中のフェニル環は、各々、互いに独立して、Ｆ原子により一置換、二置換または多置換、好ましくは一置換または二置換されていることができる、
で表される化合物からなる群から選択された１種または２種以上の化合物を好ましくは含み、特に主にこれらからなり、特に好ましくは実質的に完全にこれらからなり、極めて特に好ましくは事実上完全にこれらからなる。

Wherein the parameters are as defined above under formula VIII, wherein the phenyl rings are each independently of one another mono-, di- or polysubstituted, preferably mono- or disubstituted by an F atom. Can be disubstituted,
Preferably comprises one or more compounds selected from the group consisting of the compounds represented by the following, in particular mainly consisting of, particularly preferably substantially completely, very particularly preferably virtually Consists entirely of these.

式中、ｎおよびｍは、各々、互いに独立して、アルキル基である場合には１〜９、好ましくは１〜５および特に好ましくは１〜３であり、アルケニル基である場合には２〜９、好ましくは２〜５および特に好ましくは２〜３である、
で表される化合物からなる群から選択される。 The compounds of the formula I-1 are preferably those of the formulas I-1a to I-1e

In the formula, n and m are each independently 1 to 9, preferably 1 to 5 and particularly preferably 1 to 3 when an alkyl group, and 2 to 3 when an alkenyl group. 9, preferably 2 to 5 and particularly preferably 2 to 3,
Selected from the group consisting of compounds represented by

式中、ｎおよびｍは、各々、互いに独立して、１〜９、好ましくは１〜５および特に好ましくは１〜３である、
で表される化合物からなる群から選択される。 The compound represented by the formula II-1 is preferably a compound represented by the formulas II-1a to II-1d:

Wherein n and m are each independently of the other 1-9, preferably 1-5 and particularly preferably 1-3
Selected from the group consisting of compounds represented by

式中、
Ｒ^３１は、式ＩＩＩの下に、好ましくは式ＩＩＩ−１について前に定義した通りであり、
Ｒ^３２は、アルキル、アルコキシまたはアルケニル、特に好ましくは、１〜３個の炭素原子を有するアルキル、ビニルまたは１Ｅ−アルケニルである、
で表される化合物からなる群から選択される。 The compound represented by the formula III-1 is preferably a compound represented by the formulas III-1a to III-1c:

Where:
R ³¹ is as defined above under formula III, preferably for formula III-1,
R ³² is alkyl, alkoxy or alkenyl, particularly preferably alkyl, vinyl or 1E-alkenyl having 1 to 3 carbon atoms,
Selected from the group consisting of compounds represented by

式中、
Ｒ^３１は、式ＩＩＩについて、好ましくは式ＩＩＩ−２について前に定義した通りであり、好ましくはアルキルまたはアルケニルである、
で表される化合物からなる群から選択される。 The compounds of the formula III-2 are preferably those of the formulas III-2a to III-2e

Where:
R ³¹ is as defined above for formula III, preferably for formula III-2, preferably alkyl or alkenyl;
Selected from the group consisting of compounds represented by

式中、
Ｒ^３１は、式ＩＩＩについて、好ましくは式ＩＩＩ−８について前に定義した通りであり、好ましくはアルキルまたはアルケニルである、
で表される化合物からなる群から選択される。 Compounds of formula III-9 are preferably of formulas III-9a to III-9c

Where:
R ³¹ is as defined above for Formula III, preferably for Formula III-8, and is preferably alkyl or alkenyl;
Selected from the group consisting of compounds represented by

式中、パラメーターは、式Ｖの下に、好ましくは式Ｖ−２の下に前に定義した通りである、
で表される化合物からなる群から選択される。 The compound represented by the formula V-2 is preferably a compound represented by the formulas V-2a to V-2c:

Wherein the parameters are as defined above under Formula V, preferably below Formula V-2,
Selected from the group consisting of compounds represented by

式中、パラメーターは、式Ｖの下に、好ましくは式Ｖ−３の下に前に定義した通りである、
で表される化合物からなる群から選択される。 The compounds of the formula V-3 are preferably of the formulas V-3a to V-3e, preferably V-3d and V-3e

Wherein the parameters are as defined above under formula V, preferably under formula V-3,
Selected from the group consisting of compounds represented by

式中、パラメーターは、式ＶＩの下に、好ましくは式ＶＩ−１の下に前に定義した通りである、
で表される化合物からなる群から選択される。 The compounds of the formula VI-1 are preferably those of the formulas VI-1a to VI-1c

Wherein the parameters are as defined above under formula VI, preferably under formula VI-1.
Selected from the group consisting of compounds represented by

式中、パラメーターは、式ＶＩの下に、好ましくは式ＶＩ−２の下に前に定義した通りであり、Ｒ^６１は、アルキルまたはアルケニルであり、Ｒ^６２は、アルキル、アルケニル、Ｆまたは−ＯＣＦ_３である、
で表される化合物からなる群から選択される。 The compounds of the formula VI-2 are preferably those of the formulas VI-2a and VI-2b

Wherein the parameters are as defined above under formula VI, preferably under formula VI-2, R ⁶¹ is alkyl or alkenyl and R ⁶² is alkyl, alkenyl, F or- OCF ₃ ,
Selected from the group consisting of compounds represented by

式中、パラメーターは、式ＶＩＩの下に、好ましくは式ＶＩＩ−１の下に前に定義した通りであり、Ｒ^７１は、アルキルまたはアルケニルであり、Ｒ^７２は、アルキル、アルケニル、Ｆまたは−ＯＣＦ_３である、
で表される化合物からなる群から選択されており、特に好ましくは、式ＶＩＩ−１ｄおよびＶＩＩ−１ｅからなる群から選択されており、特に好ましくはここで、Ｒ^７２は、Ｆである。 The compounds of the formula VII-1 are preferably those of the formulas VII-1a to VII-1e

Wherein the parameters are as defined above under formula VII, preferably under formula VII-1, wherein R ⁷¹ is alkyl or alkenyl and R ⁷² is alkyl, alkenyl, F or- OCF ₃ ,
And particularly preferably selected from the group consisting of the formulas VII-1d and VII-1e, particularly preferably wherein R ⁷² is F.

In this application, the following definitions apply with respect to the specification of the components of the composition:
-"Comprising": the concentration of the relevant constituents in the composition is preferably 5% or more, particularly preferably 10% or more and very particularly preferably 20% or more,
“Consisting essentially of”: the concentration of the relevant constituents in the composition is preferably 50% or more, particularly preferably 55% or more and very particularly preferably 60% or more,

-"Consisting essentially of": the concentration of the relevant component in the composition is preferably 80% or more, particularly preferably 90% or more and very particularly preferably 95% or more And-"consisting essentially of": the concentration of the relevant constituents in the composition is preferably 98% or more, particularly preferably 99% or more and very particularly preferably 100.0 %.

This applies both to the medium as a composition with these components, which can be components and compounds, and to the components with these components, compounds.

Component B preferably consists mainly of one or more compounds selected from the group consisting of the compounds of the formulas III and IV, preferably of the formulas III-1 and III-2 and IV, in particular It preferably consists essentially entirely of these, very particularly preferably consists essentially of these. In the compounds of the formula III-1a, R ³² is preferably alkyl, alkenyl or alkoxy. Further, the clockwise phenyl ring in the compounds of formulas III and IV is preferably substituted as follows:

Component C is preferably one selected from the group consisting mainly of compounds of the formulas V-2 and V-3, preferably of the formulas V-2a, V-2b, V-2c and V-3. Alternatively, it consists of two or more compounds, particularly preferably consists essentially of them, very particularly preferably consists essentially of them. In the compounds of the formula V-2a and ^{V-2c, R 52} is preferably F, in the compound represented by the formula ^{V-2b, R 52} is preferably -OCF _3. The clockwise phenyl ring in the compound of formula V is preferably substituted as follows:

In a preferred embodiment, the liquid crystal media of the present invention, in total, based on the mixture as a whole,
5% to 85%, preferably 10% to 70% and particularly preferably 20% to 60% of component A, preferably a compound selected from the compounds of the formulas I and II, particularly preferably of the formula I,

0% to 20%, preferably 0% to 12%, particularly preferably 0% to 10% and very particularly preferably 0% to 5% of component B, preferably of formulas III and IV, particularly preferably of formula III A compound selected from the compounds to be
0% to 50%, preferably 0% to 40%, particularly preferably 10% to 40% and very particularly preferably 5% to 25% of component C, preferably of formulas V to VII, particularly preferably of formula V Including compounds selected from the compounds described above.

The medium according to the invention preferably consists mainly of components A, B and C, particularly preferably substantially completely.

The individual compounds are each used here in a concentration of 1% to 25%, preferably 2% to 20% and particularly preferably 4% to 16%. The exception here is formed by compounds having three phenyl rings and compounds having four six-membered rings. Each of these compounds is used at a concentration of 0.5% to 15%, preferably 1% to 10% and particularly preferably 1% to 8% per individual compound. Particularly in the case of compounds of the formula I and II, especially of the component A of the formula I, preferred limits on the concentration for the proportion of the individual compounds in the medium are 1% to 20%, preferably 1% to 15%. And particularly preferably from 3% to 11% and very particularly preferably up to 8%.

In a preferred embodiment, the liquid crystal medium is particularly preferably
40% to 70% of a compound of formula I,
0% to 20% of a compound of the formula III, preferably of the formula III-2, particularly preferably of the formula III-2b, and 10% to 35% of a compound of the formula V to VIII, preferably of the formula V and VII Compounds.

In this embodiment, the liquid crystal medium is very particularly preferably, in total,
40% to 80% of a compound of formulas I-1 and I-2,
It comprises from 0% to 5% of a compound of the formula III, preferably of the formula III-2, particularly preferably of the formula III-2b.

The liquid-crystalline media according to the invention preferably have a nematic phase in each case of at least −20 ° C. to 70 ° C., particularly preferably −30 ° C. to 80 ° C., very particularly preferably −40 ° C. to 90 ° C.

The term "having a nematic phase" means here that firstly no smectic phase and crystallization are observed at lower temperatures at the corresponding temperature and secondly that no clarification occurs by heating from the nematic phase Means that. Inspection at low temperature is carried out in a rheometer at the corresponding temperature and checked by storage for at least 100 hours in a test cell having a layer thickness corresponding to the electro-optical application. At elevated temperature, the clearing point is measured in a capillary tube by conventional methods.

Furthermore, the liquid crystal medium of the present invention is characterized by the following relatively high optical anisotropy values. The birefringence value is preferably in the range from 0.065 to 0.115, particularly preferably in the range from 0.075 to 0.105 and very particularly preferably in the range from 0.080 to 0.105.
In particular, the liquid crystal medium of the present invention has a relatively high optical anisotropic dispersion.

The relative birefringence dispersion (σ _Δn / Δn _mix ) of the individual compounds used is preferably 0.50 or more, preferably 0.50 to 0.90, particularly preferably 0.60 or more, It is preferably 0.60 to 0.90 and very particularly preferably 0.70 or higher, preferably 0.70 to 0.90.
Furthermore, the liquid-crystalline media according to the invention have a low value for the threshold voltage (V ₁₀ ), preferably lower than or equal to 2.00 V, preferably lower than or equal to 1.80 V. .

These preferred values for the individual physical properties are also observed in each case in combination with one another. Particularly preferred are liquid crystal media having a combination of relatively low rotational viscosities (γ ₁ ) and simultaneously high clearing points (T (N, I)) as shown in the table below.

は、トランス−１，４−シクロヘキシレンを示す。 In the present application, “≦” means small or equal, preferably small, and “≧” means large or equal, preferably large.
In this application,

Represents trans-1,4-cyclohexylene.

In the present application, the term dielectrically positive compound means a compound having a Δε of> 1.5, and a dielectrically neutral compound refers to a compound in which −1.5 ≦ Δε ≦ 1.5. By dielectrically negative compound is meant a compound having Δε <−1.5. The dielectric anisotropy of the compound is determined by dissolving 10% of the compound in a liquid crystal host, and measuring the capacitance of this mixture at 1 kHz by using at least one test cell having a homeotropic surface orientation, a thickness of 20 μm, Is determined by determining in at least one test cell having a thickness of 20 μm with a good surface orientation. The measured voltage is typically between 0.5 V and 1.0 V, but is always lower than the capacitive threshold of the respective liquid crystal mixture.

The host mixture used for dielectrically positive and dielectrically neutral compounds is ZLI-4792, the host mixture used for dielectrically negative compounds is ZLI-2857, Both are from Merck KGaA, Germany. The change in the dielectric constant of the host mixture after addition of the compound to be tested and extrapolation to 100% of the compound used gives a value for each compound to be tested.

ホ ス ト The host mixture used for the determination of the birefringence of the individual compounds is ZLI-4792 from Merck KGaA, Germany. The value for each compound to be tested is obtained from the change in the birefringence of the host mixture after addition of the compound to be tested and extrapolation to 100% of the compound used. Birefringence is determined on an oriented sample in a fitted Abbe refractometer. The aligning agent used is a solution of lecithin obtained from Merck KGaA. Birefringence was calculated from ordinary and extraordinary refractive index values, both of which were determined for identically oriented samples.

The term "threshold voltage" in the usual way, unless explicitly stated otherwise, relates to the optical threshold for 10% relative contrast (V _10).

濃度 All concentrations in the present application are expressed in weight percent and relate to the corresponding mixture or mixture components, unless explicitly stated otherwise. All physical properties are determined and determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", Status November 1997, Merck KGaA, Germany, and unless otherwise stated, a temperature of 20 ° C. Applied to Δn is determined at a wavelength of 589 nm and Δε is determined at a frequency of 1 kHz.

液晶 The liquid crystal medium of the present invention may contain, if necessary, other additives such as stabilizers in conventional amounts. The amounts of these additives used are in total from 0% to 10%, preferably from 0.1% to 6%, based on the amount of the mixture as a whole. The concentrations of the individual compounds used are preferably between 0.1 and 3% each. The concentrations of these and similar additives are not taken into account when indicating the concentration and concentration range of the liquid crystal compound in the liquid crystal medium.

The composition comprises a plurality of compounds, preferably 3 to 30, particularly preferably 6 to 20 and very particularly preferably 10 to 16 compounds, which are mixed in a customary manner. In general, the desired amount of the compound used in the smaller amount is dissolved in the components making up the main component, advantageously at an elevated temperature. If the selected temperature is higher than the clearing point of the main component, the completion of the dissolution process is particularly easy to observe. However, it is also possible to prepare the liquid-crystal mixtures in other customary ways, for example using premixes or from so-called “multibottle systems”.

With suitable additives, the liquid crystal phases of the invention can be modified such that they can be used in all types of previously disclosed ECB, VAN, IPS, GH or ASM-PA LCD displays. .
The following examples have the effect of exemplifying the invention without limiting it. In the example, the melting point T (C, N), the temperature T (S, N) of the transition from the smectic (S) phase to the nematic (N) phase, and the clearing point T (N, I) of the liquid crystal material are expressed in degrees Celsius. Show.

Unless explicitly stated otherwise, percentages herein are weight percentages and physical properties are at 20 ° C., unless explicitly stated otherwise.
Unless otherwise specified, all percentages herein are percent by weight and all physical properties are at 20 ° C., unless explicitly stated otherwise.
All values given for temperatures in this application are in ° C., and all temperature differences are correspondingly degrees of difference, unless explicitly stated otherwise.

In the present application and in the following examples, the structures of the liquid crystal compounds are indicated by abbreviations (initials), and the conversion to the chemical formula is performed according to Tables A and B below. All groups C _n H _{2n + 1} and C _m H _{2m + 1} are straight-chain alkyl groups having n and m carbon atoms, respectively. The codes in Table B are self-evident. In Table A, only the initials for the basic structure are shown. In individual cases, the initials of the basic structure are followed by a code for the substituents R ¹ , R ² , L ¹ , L ² and L ³ , separated by a hyphen:

Table A

Table B:

The liquid-crystalline media according to the invention are preferably selected from the formulas from Tables A and B, of 5 or 6 or more, particularly preferably 6 or 7 and very particularly preferably 7 or 8 or more. Including compounds.
The liquid-crystalline media according to the invention preferably comprise two or more, particularly preferably three or more, and very particularly preferably four or more compounds selected from the formulas from Table A. Including.

The liquid-crystalline media according to the invention preferably comprise three or more or more, particularly preferably four or more and very particularly preferably five or more than six compounds selected from the formulas from Table B. Including.
These compounds are preferably compounds of different formulas from these tables.

The following examples are intended to illustrate the invention without limiting it. As used herein, percentages are weight percentages. All temperatures are given in degrees Celsius. Δn indicates optical anisotropy (589 nm, 20 ° C.), Δε indicates dielectric anisotropy (1 kHz, 20 ° C.). R. Indicates a voltage holding ratio (1 V after 5 minutes in an oven at 100 ° C.), and V ₀ and a threshold voltage (abbreviated as HR) were determined at 20 ° C.

Comparative Example 1
Tricyclic compounds in which one or two of the three rings are phenyl rings and the remaining rings are cyclohexyl rings, and one of the two rings is a phenyl ring and the other is a cyclohexyl ring A liquid crystal mixture consisting exclusively of the bicyclic compound was prepared. The composition and physical properties of this mixture are shown in the table below.

The liquid crystal medium was tested for this dispersion. The birefringence values at various wavelengths are shown in the table below.

Comparative Example 2
Tricyclic compounds in which one or two of the three rings are phenyl rings and the remaining rings are cyclohexyl rings, and one of the two rings is a phenyl ring as in Comparative Example 1. A liquid crystal mixture was prepared, consisting exclusively of bicyclic compounds, one being the cyclohexyl ring and the other being the cyclohexyl ring. The composition and physical properties of this mixture are shown in the table below.

The liquid crystal medium was tested for this dispersion. The birefringence values at various wavelengths are shown in the table below.

Example 1
A liquid crystal mixture according to the teachings of the present application was prepared. This liquid crystal mixture comprises a large proportion of tricyclic compounds in which all three rings are phenyl rings, tricyclic compounds in which all three rings are cyclohexyl rings, and two rings which are cyclohexyl rings. Including certain bicyclic compounds. This liquid crystal mixture does not include tricyclic compounds in which one or two of the three rings are phenyl rings and the remaining rings are cyclohexyl rings.

透明 The clearing point and birefringence of the mixture of this example were set to the corresponding values of the comparative example. The composition and physical properties of this mixture are shown in the table below.

The liquid crystal medium was tested for this dispersion. The birefringence values at various wavelengths are shown in the table below.

The liquid crystal mixture of this example has a significantly larger dispersion than the mixture of the two comparative examples 1 and 2. This is shown in the table below, where the relative birefringence dispersions (σ _Δn / Δn _mix ) of the individual compounds used were compared to each other.

Claims (10)

A method for setting the dispersion of a liquid crystal medium, wherein the individual compounds are used such that the relative birefringence dispersion (δ _Δn / Δn _mix ) of the individual compounds (Δn _i ) used is 0.50 or more. The method as described above. A nematic liquid crystal medium,
a) components A and b) consisting of compounds having a low birefringence (Δn) in the range of 0.080 or less, optionally compounds having a medium birefringence in the range of 0.081 to 0.149 And B) a component C comprising a compound having a high birefringence in the range of 0.150 or more
A nematic liquid crystal medium comprising: 3. The liquid crystal medium according to claim 1, having a birefringence in the range of 0.070 to 0.110. The liquid crystal medium according to claim 1, further comprising a component B. Component A mainly comprises compounds of the formulas I and II

Where:
R ¹¹ , R ¹² , R ²¹ and R ²² are each, independently of one another, alkyl having 1 to 15 carbon atoms, which is optionally monosubstituted by at least halogen, wherein , One or more CH ₂ groups are in each case independently of one another —O—, —S—, —CH ＝ CH—,

-CO -, - CO-O - , - by O-CO- or -O-CO-O-, it can the O atom is substituted so as not linked directly to one another, or ^{alternatively, R 11} and ^{R 12} Is H or F; R ²² is alternatively F or Cl;
Z ^{11, Z 12} and ^{Z 2} are each, independently of one _{another, -CH 2 -CH 2 -, -} CF 2 -CF 2 -, - CF 2 -CH 2 -, - CH 2 -CF 2 -, - CH = CH -, - CF = CF -, - CF = CH -, - CH = CF -, - C≡C -, - COO -, - OCO -, - CH 2 O -, - OCH 2 -, - CF ₂ O—, —OCF ₂ —, — (CH ₂ ) ₄ — or a single bond;
n is 0, 1 or 2;
and,
One or two non-adjacent CH ₂ groups in the cyclohexane ring in Formulas I and II may be replaced by an O atom, and the phenyl ring in Formula II may be replaced by one or two F atoms. Can be replaced,
5. The liquid crystal medium according to claim 1, comprising a compound selected from the group consisting of compounds represented by: Component B mainly comprises compounds of formulas III and IV

Where:
R ³¹ , R ³² , R ⁴¹ and R ⁴² are each, independently of one another, as defined for R ²¹ in claim 6,
Z ³¹ , Z ³² , Z ⁴¹ and Z ⁴² are each independently of one another as defined for Z ¹¹ in claim 6;
The liquid crystal medium according to any one of claims 1 to 5, comprising a compound selected from the group consisting of compounds represented by the formula: Component C mainly comprises compounds of formulas V to VII

Where:
R ⁵¹ , R ⁵² , R ⁶¹ , R ⁶² , R ⁷¹ and R ⁷² are each, independently of one another, as defined for R ²¹ in claim 6,
Z ⁵¹ , Z ⁵² , Z ⁶¹ , Z ⁶² , Z ⁶³ , Z ⁷¹ , Z ⁷² and Z ⁷³ are each independently of the other as defined for Z ¹¹ in claim 6,
m and o are each, independently of one another, 0 or 1;
The liquid crystal medium according to any one of claims 1 to 6, comprising a compound selected from the group consisting of compounds represented by: An electro-optical display comprising the liquid crystal medium according to claim 1. 9. The display according to claim 8, wherein the display is an active matrix display. Use of a liquid crystal medium according to any of claims 1 to 9 in an electro-optical display.