JPH10218801A - Liquid crystalline compound, liquid crystal composition and liquid crystal displaying element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject new compound useful as a liquid crystal compound having a low viscosity and a good solubility under low temperatures. SOLUTION: This liquid crystalline compound is a compound of formula I [ring A is a (substituted) trans-1, 4-cyclohexylene, etc.; Q<1> , Q<2> are each a 1-15C alkylene or a single bond; X<1> to X<4> are each H or a halogen; Y<1> , Y<2> are each H, a halogen or a 1-15C alkyl; (n) is 0, 1], e.g. a compound of formula II. The compound of formula I is obtained by performing a Wittig reaction of a triphenylphosphonium halide derivative of formula III with an aldehyde derivative of formula IV in an ethereal solvent in the presence of a base, effecting diisobwtlylaluminum hydride with the obtained compound to obtain another aldehyde derivative, performing the Wittig reaction similarly as above, converting the obtained compound to an epoxy derivative, then effecting dibromotriphenylphosphorane thereto, and effecting an organic acid, etc., to the obtained compound of formula V by using zinc as a catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystal compound having an alkenyl group in a monocyclic molecule, a liquid crystal composition using the same, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art A large number of display devices utilizing the anisotropy of the refractive index and the anisotropy of the dielectric constant, which are characteristics of liquid crystal compounds, have been produced. Display devices using liquid crystal compounds for watches, calculators, word processors, televisions, and the like are widely used, and demands are increasing year by year.

The liquid crystal phase is located between the solid phase and the liquid phase,
The phases are roughly classified into a nematic phase, a smectic phase, and a cholesteric phase. Of these, display elements utilizing a nematic phase are currently most widely used. Further, as a display system applied to a liquid crystal display, a TN (twisted nematic) type, a DS (dynamic scattering) for an electro-optic effect are used.
Type, guest-host type, DAP type and the like.

Many liquid crystal compounds including those in the research stage have been known so far, but there is no liquid crystal substance which can be conventionally used alone by being sealed in a display element. The liquid crystal compound expected as a display element material exhibits a liquid crystal phase in a temperature range as wide as possible in the natural world, particularly at room temperature, which is most frequently used as a display element, and also has an effect on environmental factors used. And is stable enough
Further, it has physical properties sufficient to drive the display element. However, a single liquid crystal compound satisfying all of these conditions has not been found. Therefore, at present, a composition having characteristics meeting the above conditions is prepared by mixing several kinds of liquid crystal compounds or non-liquid crystal compounds, and is used as a liquid crystal material for a display element.

[0005] These liquid crystal compositions are required to be stable to moisture, light, heat, air and the like which are usually present in a use environment. In addition, it is required that the liquid crystal compounds to be mixed be chemically stable in the use environment with each other, in addition to the stability against electric field and electromagnetic radiation.

The liquid crystal composition has a refractive index anisotropy value (△
n), dielectric anisotropy value (△ ε), viscosity (η), conductivity,
And the elastic constant ratio K ₃₃ / K ₁₁ (K ₃₃ : bend elastic constant,
It is also required that various physical properties such as K ₁₁ : spray elastic constant) have optimum values depending on the display method and the shape of the element. Further, each liquid crystal component in the liquid crystal composition is required to have good mutual solubility.

On the other hand, in terms of applications, in recent years, colorization of display devices using liquid crystal has been rapidly progressing. In a display method using a TN type, a thin film transistor (TF
T) system and super twist nematic (STN)
The methods have become mainstream, and display elements based on these methods have been mass-produced. And C which is the mainstream of the current TV screen
RT is expected to eventually replace liquid crystal displays.

However, in order to achieve this, the liquid crystal display is required to have display characteristics comparable to a CRT. Conventionally, it is possible to display a moving image even in the STN method, but the difficulty of generating an afterimage when displaying the moving image has hitherto stood in the development of a television using a liquid crystal display.

In order to prevent the occurrence of afterimages, it is essential to increase the response speed of liquid crystal molecules to an applied voltage. To solve this problem, 1) a method of reducing the cell thickness, 2).
A method using a low-viscosity liquid crystal compound is generally known. In the method of reducing the cell thickness, the display contrast and the viewing angle are greatly affected by the product (Δn · d) of Δn and the cell thickness (d). A drop occurs, which is not preferable. On the other hand, the method of lowering the viscosity of the liquid crystal material to be used is a good method that can realize smooth high-speed response.

In general, compounds having an alkenyl group in the molecule are well known as low viscosity compounds. It is also known that the smaller the number of rings constituting the compound, that is, three rings from the compound having four rings and two rings from the three rings, the lower the viscosity of the compound becomes.

Regarding a compound having a six-membered monocyclic ring and an alkenyl group, Indian J. Chem., Sect.
5 (8), 753, (1977) and Synth.Commun. 13 (2), 17
7, (1983) report the following several compounds.

[0012]

Embedded image However, these compounds have not been developed for use in liquid crystal displays. That is,
Since any of the above compounds has an introduced alkenyl group conjugated with a benzene ring, it is apparent that the stability under ultraviolet irradiation is extremely low and it is difficult to use the compound as a liquid crystal material.

Referring to rings, three-membered rings, four-membered rings,
Various rings such as a five-membered ring have been found so far.However, since liquid crystal compounds have been developed mainly with a six-membered ring that easily exhibits a liquid crystal phase, liquid crystal properties and other liquid crystal properties have been developed. Considering the compatibility with the compound, a six-membered ring compound is extremely useful.

Further, as a phenomenon that has recently become a problem in STN-type display elements, there is threshold unevenness (hereinafter abbreviated as burn-in). Various reports have been made on this phenomenon very recently, and although the decisive factors are still unknown, it is presumed that the phenomenon is caused by the bias of impurity ions in the display surface. In order to solve these phenomena, it has recently been known that a liquid crystal material formed using a compound having an unsaturated bond group such as an alkenyl group is effective. However, the effect is still insufficient.

As described above, the characteristics required for a liquid crystal material used in a high-quality STN type liquid crystal display device are complicated, and the development of a new liquid crystal material, that is, a liquid crystal compound that satisfies those requirements, has been developed. There is a strong demand.

[0016]

The inventors of the present invention have made various studies to solve the above problems, and found that an alkenyl compound having a specific structure has low viscosity and excellent compatibility at low temperatures. Further, the inventors have found that the performance of suppressing the occurrence of burn-in in the STN display system is significantly superior to the conventionally known alkenyl compounds, and have completed the present invention. .

Accordingly, an object of the present invention is to have a significantly lower viscosity than that of a conventional liquid crystalline compound, a remarkably good solubility at a low temperature, and an STN.
It is an object of the present invention to provide a liquid crystal compound having a remarkably excellent performance of suppressing the occurrence of a burn-in phenomenon in a display system, a liquid crystal composition containing the same, and a liquid crystal display device formed using the liquid crystal composition.

[0018]

In order to achieve the above object, the present invention provides [1] a general formula (1)

[0019]

Embedded image (Wherein ring A is trans-1,4 in which one or more carbon atoms in the cyclohexane ring may be substituted with a silicon atom.
A cyclohexylene group, a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, a pyrimidine-2,5-diyl group, a pyridine-2,5
-Diyl group, 1,3-dioxane-2,5-diyl group,
It represents a tetrahydropyran-2,5-diyl group, a 1,3-dithiane-2,5-diyl group, or a tetrahydrothiopyran-2,5-diyl group.

Q ¹ and Q ² each independently have 1 to 1 carbon atoms.
It represents 15 alkylene groups or single bonds. Any methylene group not adjacent to each other in the alkylene group (-CH
_2- ) may be substituted by an oxygen atom (-O-) or -CH = CH-.

X ¹ , X ² , X ³ and X ⁴ each independently represent a hydrogen atom or a halogen atom.

Y ¹ and Y ² each independently represent a hydrogen atom,
It represents a halogen atom or an alkyl group having 1 to 15 carbon atoms. Any non-adjacent methylene groups in the alkyl group may be replaced by an oxygen atom or -CH = CH-.

N is 0 or 1. Each element constituting the compound includes its isotope. )), Wherein [2] ring A is
A trans-1,4-cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, and Q ¹ and Q ² are single bonds [3] ring A is a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, and Q ¹ is any methylene groups not adjacent to each other in an alkylene group and the alkylene group having 1 to 15 carbon atoms (-CH ₂ -) is an oxygen atom (-O-) or -CH = C
H ² may be substituted by H—, Q ² is a single bond, [4] ring A is trans-1,4
A cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, wherein Q ¹ and Q ² are any methylene groups which are not adjacent to each other (-CH _2- ) is an oxygen atom (-O-) or -C
H = C1-C1 which may be substituted by CH-
5 alkylene group.

Further, the present invention provides a liquid crystal composition comprising at least one compound represented by the general formula (1) and comprising at least two components.

Also, the present invention provides [6] a first component containing at least one liquid crystal compound according to any of the above [1] to [4], and a second component represented by the general formula (2): (3) and (4),

[0026]

Embedded image (Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms. Any non-adjacent methylene groups in the alkyl group are
It may be substituted by an oxygen atom or -CH = CH-. Also, any hydrogen atom in the alkyl group may be replaced by a fluorine atom.

Y ³ is a fluorine atom, a chlorine atom, OCF ₃ , O
CF ₂ H, CF ₃ , CF ₂ H, CFH _{2 ,} OCF ₂ CF ₂ H or OCF ₂ CFHCF ₃ is shown.

L ¹ and L ² each independently represent a hydrogen atom or a fluorine atom.

Z ¹ and Z ² each independently represent 1,2-ethylene, vinylene, 1,4-butylene, —COO
—, —CF ₂ O—, —OCF ₂ — or a single bond.

Ring B represents a trans-1,4-cyclohexylene group, a 1,3-dioxane-2,5-diyl group, or a 1,4-phenylene group in which a hydrogen atom may be substituted by a fluorine atom. .

Ring C represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which a hydrogen atom may be substituted by a fluorine atom. Further, each atom in each formula includes isotopes. A liquid crystal composition comprising at least one compound selected from the group consisting of:

The present invention also provides [7] at least one liquid crystal compound according to any one of the above [1] to [4] as a first component, and a general formula (5) as a second component.
And (6)

[0033]

Embedded image (Wherein, R ² and R ³ independently of one another have 1 to 10 carbon atoms)
Represents an alkyl group. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or a vinylene group. Further, any hydrogen atom in the alkylene group may be substituted with a fluorine atom.

Y ⁴ represents a CN group or a C≡C-CN group.

Ring D is a trans-1,4-cyclohexylene group, 1,4-phenylene group, pyrimidine-2,5-
It represents a diyl group or a 1,3-dioxane-2,5-diyl group.

Ring E is a trans-1,4-cyclohexylene group, in which a hydrogen atom may be substituted by a fluorine atom.
-A phenylene group or a pyrimidine-2,5-diyl group.

Ring F represents a trans-1,4-cyclohexylene group or 1,4-phenylene group, and Z ³ represents 1,2
-Represents an ethylene group, -COO-, or a single bond.

L ³ , L ⁴ and L ⁵ independently represent a hydrogen atom or a fluorine atom.

A, b, and c each independently represent 0 or 1. Also, each atom in each formula includes isotopes. A liquid crystal composition comprising at least one compound selected from the group consisting of:

Also, the present invention provides [8] a liquid crystal compound according to any one of the above [1] to [4] as a first component, and a compound represented by the general formula (7):
(8) and (9)

[0041]

Embedded image (Wherein, R ⁴ and R ⁵ independently of one another have 1 to 10 carbon atoms)
Represents an alkyl group. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or a vinylene group. Further, any hydrogen atom in the alkylene group may be substituted with a fluorine atom.

Ring G, ring I and ring J are each independently a trans-1,4-cyclohexylene group, a pyrimidine-2,5-diyl group or one or more hydrogen atoms substituted by fluorine atoms. 1 shows a 1,4-phenylene group which may be substituted.

Z ⁴ and Z ⁵ independently of one another,
-Ethylene group, vinylene group, -COO-, -C−C-,
Or a single bond. Further, each atom in each formula includes isotopes. A liquid crystal composition comprising at least one compound selected from the group consisting of:

The present invention also provides

[9] As the first component,
It contains at least one liquid crystal compound according to any one of the above [1] to [4], and as a second component, at least one compound selected from the group consisting of the general formulas (5) and (6). A liquid crystal composition characterized by containing at least one compound selected from the group consisting of the general formulas (7), (8) and (9) as a third component.

The present invention also provides [10] a first component containing at least one liquid crystal compound according to any one of the above [1] to [4], and a second component represented by the general formula (2) ), (3) and (4) containing at least one compound selected from the group consisting of
It contains at least one compound selected from the group consisting of the general formulas (5) and (6), and is selected from the group consisting of the general formulas (7), (8) and (9) as a fourth component. A liquid crystal composition comprising at least one compound represented by the formula:

Further, the present invention relates to [11] the above [1] to
A liquid crystal composition characterized by further comprising one or more optically active compounds in addition to the liquid crystal composition according to any one of [10].

Further, the present invention provides the above-mentioned [12]
A liquid crystal display device comprising the liquid crystal composition according to any one of [11] to [11].

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The liquid crystal compound represented by the general formula (1) of the present invention is a monocyclic alkenyl derivative having an alkenyl group at one or both of the 1- and 4-positions of the 6-membered ring. These compounds are not only physically and chemically very stable under the conditions in which the display device manufactured using these compounds is used, but also have a solubility in the liquid crystal composition even at a low temperature. It is characterized by high and low viscosity. As shown in the prior art,
Compounds having an alkenyl group at the 1,4-position of the monocyclic benzene ring have already been disclosed in papers and the like, but most of the uses are mainly used for raw materials for polymer synthesis.
It is considered impossible to easily recognize the use as a liquid crystal composition.

The liquid crystal compound of the present invention not only imparts stability to the compound but also arbitrarily adjusts desired physical property values by optimally designing a ring structure or a side chain structure among molecular constituent elements. is there.

Further, when the liquid crystal compound of the present invention is used as a component of a liquid crystal composition, it has the following good characteristics. 1) Since the clearing point can be freely changed by changing the length of the side chain of the compound, a liquid crystal composition having a nematic phase in a desired temperature range can be prepared. 2) Even at very low temperatures, a stable nematic liquid crystal composition free of crystal precipitation and no smectic phase can be prepared. 3) Response speed is improved due to low viscosity. 4) The effect of preventing burn-in in STN display is large.

Therefore, it is stable against the external environment,
It is possible to provide a novel liquid crystal composition and a liquid crystal display element capable of realizing an extended use temperature range, low voltage driving, high-speed response, and high contrast.

As described above, the liquid crystalline compound of the present invention comprises
Each of them has suitable physical properties, but more specifically, the ring A, Q ¹ , Q ² ,
By appropriately selecting X ¹ , X ² , X ³ , X ⁴ , Y ¹ and Y ² and using the compound, a liquid crystal composition can be prepared according to the purpose.

That is, if an extremely low-viscosity liquid crystal composition is required, the liquid crystalline compound may be, for example, a trans-1,4-cyclohexylene group or X ³ , X ⁴ , Y ^{1 in} the ring A of the formula (1). And those in which Y ² is independently a fluorine atom may be appropriately selected. If a large refractive index anisotropy value is required, a 1,4-phenylene group in ring A may be appropriately selected.

Furthermore, if a clearing point on the high temperature side is required, the sum of the carbon numbers of Q ¹ and Y ¹ and Q ² and Y ² may be independently selected so as to be 8 or more.

If a clearing point on the low temperature side is required, it may be appropriately selected such that the sum of the carbon numbers of the same combination as described above becomes 7 or less.

Further, those obtained by substituting fluorine on 1,4-phenylene group show particularly excellent low-temperature solubility.

In consideration of the liquid crystallinity, n is preferably 1 rather than 0, and it is preferable that Y ¹ and Y ² also have an alkenyl group as appropriate for preventing image sticking.

Next, the liquid crystalline compound of the present invention will be described.

It should be noted that 1 in 1,4-cyclohexylene
A compound in which the carbon atom at the 4- or 4-position is substituted with a silicon atom has a feature of being superior in compatibility with other liquid crystal compounds and liquid crystal compositions at a low temperature as compared with an unsubstituted one.

The following are particularly preferred examples of Q ¹ , Q ² , Y ¹ and Y ² in the formula (1).

[0062]

Embedded image

[0063]

Embedded image Hereinafter, the liquid crystal composition of the present invention will be described. The liquid crystal composition according to the present invention comprises at least one compound represented by the general formula (1) in an amount of 0.1 to 0.1% based on the total weight of the liquid crystal composition.
It is preferably contained at a ratio of 99.9% by weight in order to exhibit excellent characteristics as a liquid crystal, more preferably 3 to 90% by weight, and particularly preferably 5 to 60% by weight.

More specifically, the liquid crystal composition provided by the present invention comprises, in addition to a first component containing at least one compound represented by the general formula (1), a compound represented by the general formula: It is completed by mixing the compounds arbitrarily selected from the compound group represented by (2) to (9) at a predetermined ratio.

The general formulas (2) to (4) used in the present invention
Preferred examples of the compound include the following compounds.

In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or -CH = CH-. Also, any hydrogen atom in the alkyl group may be replaced by a fluorine atom.

Y ³ is a fluorine atom, a chlorine atom, OCF ₃ , O
CF ₂ H, CF ₃ , CF ₂ H, CFH _{2 ,} OCF ₂ CF ₂ H or OCF ₂ CFHCF ₃ is shown.

[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

Embedded image The compounds represented by the general formulas (2) to (4) are compounds having a positive dielectric anisotropy value, and have extremely excellent thermal stability and chemical stability. In particular, TFTs (A) that require high reliability such as high voltage holding ratio or high specific resistance value
It is an indispensable compound when preparing a liquid crystal composition for (M-LCD) mode.

The amount of the compounds represented by the general formulas (2) to (4) is from 0.1 to 99.9% by weight based on the total weight of the liquid crystal composition when preparing a liquid crystal composition for TFT. % Can be used arbitrarily, but is preferably 10 to 97% by weight.
More preferably, it is 40 to 95% by weight. Further, the compounds represented by the general formulas (7) to (9) may be further contained for the purpose of adjusting the viscosity. When preparing a liquid crystal composition for the STN display mode or the TN display mode, general formulas (2) to
The compound represented by (4) can be used. In this case, since the effect of lowering the threshold voltage of the liquid crystal composition is less than that of the compounds represented by the general formulas (5) and (6), the amount used is preferably 50% by weight or less. The compounds represented by formulas (5) and (6) used in the present invention preferably include the following compounds.

In the formula, R ² and R ³ independently represent an alkyl group having 1 to 10 carbon atoms. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or a vinylene group. Further, any hydrogen atom in the alkylene group may be substituted with a fluorine atom. Y ⁴
Represents a CN group or a C≡C-CN group.

[0079]

Embedded image

[0080]

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[0081]

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[0082]

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[0083]

Embedded image The compounds represented by the general formulas (5) and (6) have a positive and large dielectric anisotropy value, and are used particularly for the purpose of reducing the threshold voltage of the liquid crystal composition. It is also used for the purpose of adjusting the value of the refractive index anisotropy and expanding the nematic range such as increasing the clearing point. Further, it is also used for the purpose of improving the steepness of a liquid crystal composition for STN display mode or TN display mode.

The compounds represented by the general formulas (5) and (6) are indispensable especially when preparing a liquid crystal composition for STN display mode or TN display mode.

When the amount of the compounds represented by the general formulas (5) and (6) is increased, the threshold voltage of the liquid crystal composition decreases, and the viscosity increases. Therefore, as long as the viscosity of the liquid crystal composition satisfies the required characteristics, it is advantageous to use a large amount of the liquid crystal composition because it can be driven at a low voltage. The amount of the compounds represented by the general formulas (5) and (6) is in the range of 0.1 to 99.9% by weight when a liquid crystal composition for STN display mode or TN display mode is prepared. It can be used arbitrarily, but preferably 10 to 97% by weight, more preferably 40 to 97% by weight.
~ 95% by weight is preferred.

The general formulas (7) to (9) used in the present invention
Preferred examples of the compound represented by the following include the following compounds. In the formula, R ⁴ and R ⁵ have 1 to 1 carbon atoms.
Represents 10 alkyl groups. Any non-adjacent methylene groups in the alkyl group may be an oxygen atom or -CH = C
It may be substituted with H-. Also, any hydrogen atom in the alkyl group may be replaced by a fluorine atom.

[0087]

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[0088]

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[0089]

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[0090]

Embedded image The compounds represented by the general formulas (7) to (9) are compounds having a small or close to zero absolute value of dielectric anisotropy. The compound represented by the general formula (7) is mainly used for the purpose of adjusting the viscosity of the liquid crystal composition or the refractive index anisotropy value. Further, the compounds represented by the general formulas (8) and (9) are used for the purpose of widening the nematic range such as increasing the clearing point of the liquid crystal composition or adjusting the refractive index anisotropy value.

When the amount of the compounds represented by the general formulas (7) to (9) is increased, the threshold voltage of the liquid crystal composition increases and the viscosity decreases. Therefore, it is desirable to use a large amount as long as the threshold voltage of the liquid crystal composition is satisfied. The amount of the compounds represented by the general formulas (7) to (9) is preferably 40% by weight or less, more preferably 35% by weight or less when a liquid crystal composition for a TFT is prepared. In the case of preparing a liquid crystal composition for an STN display mode or a TN display mode, the content is 70% by weight or less, more preferably 60% by weight or less.
Except for special cases such as liquid crystal composition for liquid crystal composition for liquid crystal composition, normally, the helical structure of the liquid crystal composition is induced to adjust the required twist angle, and the reverse twist (rever
For the purpose of preventing se twist), an optically active compound is added.
As the optically active compound, any known optically active compound may be used as long as it is used for such a purpose, but the following optically active compounds are preferred.

[0092]

Embedded image The liquid crystal composition of the present invention usually adjusts the pitch length of the twist by adding these optically active compounds. The pitch length of the twist is preferably adjusted in the range of 10 to 200 μm for a liquid crystal composition for TFT and TN. If the liquid crystal composition for STN is 6 to 20 μm
It is preferable to adjust the range. Bistable (Bista
In the case of the ble TN) mode, it is preferable to adjust the thickness in the range of 1.5 to 4 μm. Two or more optically active compounds may be added for the purpose of adjusting the temperature dependence of the pitch length.

The liquid crystal composition of the present invention is prepared by a conventional method. Generally, a method of dissolving various components at a high temperature is adopted.

The liquid crystal composition of the present invention comprises a merocyanine compound,
A dichroic dye such as a styryl-based, azo-based, azomethine-based, azoxy-based, quinophthalone-based, anthraquinone-based, or tetrazine-based dye can be added to be used as a guest host (GH) mode liquid crystal composition. Alternatively, NCAP produced by microencapsulating nematic liquid crystal,
It can also be used as a liquid crystal composition for a polymer dispersed liquid crystal display (PDLCD) represented by a polymer network liquid crystal display (PNLCD) in which a three-dimensional network polymer is prepared in a liquid crystal.

In addition, a birefringence control (ECB) mode,
It can also be used as a liquid crystal composition for a dynamic scattering (DS) mode.

The liquid crystal compound represented by the formula (1) of the present invention is:
It can be easily manufactured by making full use of ordinary synthetic organic chemical techniques. For example, it can be easily synthesized by appropriately selecting and combining known reactions described in books such as Organic Synthesis, Organic Reactions, New Laboratory Chemistry Course, and magazines.

For example, it can be produced by the route of the following chemical reaction formula.

[0098]

Embedded image That is, tetrahydrofuran (hereinafter abbreviated as THF),
Sodium methylate, potassium t-butoxide (t-BuO) in an ether solvent such as diethyl ether
K) A Wittig reaction of the triphenylphosphonium halide derivative of ( 12 ) with the aldehyde derivative ( 11 ) in the presence of a base such as butyllithium gives ( 13 ). Then, aldehyde derivative ( 14 ) can be obtained by reacting diisobutylaluminum hydride (hereinafter abbreviated as DIBAL) with ( 13 ) in toluene. Further, ( 16 ) can be obtained by subjecting ( 14 ) and a triphenylphosphonium halide derivative ( 15 ) to a Wittig reaction in the same manner as in the method for obtaining ( 13 ) from ( 11 ).

In methylene chloride, ( 16 ) is reacted with 3-chloroperbenzoic acid (mCPBA) to obtain an epoxy derivative ( 17 ), and then dibromotriphenylphosphorane is reacted to obtain ( 18 ). The compound of the present invention ( 19 ) can be obtained by reacting ( 18 ) with an organic acid such as acetic acid, formic acid, p-toluenesulfonic acid, or a mineral acid such as hydrochloric acid or sulfuric acid using zinc as a catalyst.

Compounds of the formula (1) wherein ring A is a silacyclohexane ring are disclosed in JP-A-7-70148 and JP-A-7-70148.
It can be manufactured according to the method disclosed in US Pat.

The compound (1) of the present invention can be produced by appropriately selecting the above reaction.

The liquid crystalline compound (1) of the present invention thus obtained has a low viscosity, is easily mixed with other various liquid crystal materials even at low temperatures, has a remarkable anti-seizure effect, It is extremely excellent as a constituent component of a nematic liquid crystal composition suitable for a type display system.

[0103]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. The structure of the compound was confirmed by a nuclear magnetic resonance spectrum (hereinafter abbreviated as ¹ H-NMR), a mass spectrum (hereinafter abbreviated as MS), and the like. In the examples, NM
In R, m represents a multiplet. In MS, M ⁺ represents a molecular ion peak. Cr indicates a crystal phase, Iso indicates an isotropic liquid phase, and the units of the phase transition temperature are all ° C.

Example 1 trans-1,4-di-((E) -n-heptenyl) cyclohexane (in the formula (1), ring A is trans-
1,4-cyclohexylene group, Q ¹ and Q ² are a single bond,
Production of a compound in which X ¹ , X ² , X ³ and X ⁴ are hydrogen atoms, Y ¹ and Y ² are n-pentyl groups, and n is 1 (Compound No. 2).

First stage n-hexyltriphenylphosphonium bromide 127
A mixture of 0 grams (2970 mmol) and 6.5 liters of THF was cooled to -50 ° C under a stream of nitrogen. To this mixture was added 307 g (2740 mmol) of t-BuOK and stirred for 1 hour. A solution of 160 g (1140 mmol) of trans-1,4-diformylcyclohexane in 1.2 liter of THF was added dropwise to the mixture while maintaining the temperature at -50 ° C or lower. After the dropwise addition, the reaction temperature was gradually raised to room temperature, and the mixture was further stirred for 5 hours. Insolubles were removed by filtration through Celite, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent: heptane) to obtain crude trans-1,4-di- (n-heptenyl).
171 grams of cyclohexane were obtained.

Stage 2 427 grams (2480 mmol) of mCPBA and 860 grams (6200 mmol) of potassium carbonate were added to 6.5 liters of dichloromethane and cooled to 5 ° C. under a stream of nitrogen. The crude transformer-1,4-di- obtained in the first stage
171 grams of (n-heptenyl) cyclohexane (61
2.0 liters of a 9 mmol) dichloromethane solution was added dropwise, and the mixture was stirred at room temperature for 15 hours. 5 times with 3.0 liter of saturated aqueous sodium thiosulfate solution, 3 times with 3.0 liter of water
After washing twice, it was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent: a mixed solvent of ethyl acetate / heptane = 7/3 (by volume)) to obtain crude trans-1,4-
171 grams of bis- (1,2-epoxy-n-heptyl) cyclohexane were obtained.

Stage 3 Crude trans-1,4-bis- (1,2-epoxy-
171 grams (555 mmol) of n-heptyl) cyclohexane and 750 of dibromotriphenylphosphorane
Gram (1780 mmol) was added to 5.0 liters of toluene, and the mixture was refluxed for 5 hours under a nitrogen atmosphere. Silica gel was spread on the filter paper, filtered while hot, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent: heptane). Recrystallized from heptane,
51.3 grams of trans-1,4-bis-((E) -1,2-dibromo-n-heptyl) cyclohexane were obtained.

Stage 4 Trans-1,4-bis-((E) -1,2-dibromo-n-heptyl) cyclohexane 50.0 g (8
3.9 mmol), 32.9 g (503 mmol) of zinc and 500 ml of acetic acid in 500 parts of toluene.
The mixture was stirred at room temperature for 3 hours under a nitrogen stream. After removing the insoluble matter by filtration through Celite, 500 ml of water was added to carry out liquid separation. The obtained organic phase was washed twice with 500 ml of 2N-sodium hydroxide and three times with 500 ml of water, and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent: heptane) to obtain a crude product. This crude product was heptane / solmix = 3
Recrystallization from a mixed solvent of / 1 gave 6.30 g of the title compound. Phase transition temperature: Cr 6.16 Iso ¹ H-NMR: δ: (ppm): 0.60 to 2.35
(M, 32H), 5.25-5.50 (m, 4H). MS: m / e = 276 (M ^<+> ), 205, 177, 13
5,67,41.

Example 2 trans-1,4-di-((E) -n-tridecenyl)
Cyclohexane (in the formula (1), ring A is trans-
1,4-cyclohexylene group, Q ¹ and Q ² are a single bond,
Production of a compound in which X ¹ , X ² , X ³ and X ⁴ are hydrogen atoms, Y ¹ and Y ² are n-undecyl groups and n is 1 (Compound No. 4).

First stage n-dodecyltriphenylphosphonium bromide 170
A mixture of 0 grams (3330 mmol) and 7.0 liters of THF was cooled to -50 ° C under a stream of nitrogen. To this mixture was added 411 g (3660 mmol) of t-BuOK and stirred for 1 hour. To this mixture was added dropwise a solution of trans-1,4-diformylcyclohexane (180 g, 1280 mmol) in THF (1.8 L) while maintaining the temperature at -50 ° C or lower. After the dropwise addition, the reaction temperature was gradually raised to room temperature, and the mixture was further stirred for 5 hours. Insolubles were removed by filtration through Celite, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent: heptane),
240 g of crude trans-1,4-di- (n-tridecenyl) cyclohexane were obtained.

Stage 2 374 grams (2170 mmol) of mCPBA and 749 grams (5420 mmol) of potassium carbonate were added to 6.0 liters of dichloromethane and cooled to 5 ° C. under a stream of nitrogen. 240 grams of the crude trans-1,4-di-n-tridecenylcyclohexane obtained in the first stage (54
2.4 mmol) of a dichloromethane solution (2 mmol) was added dropwise, and the mixture was stirred at room temperature for 15 hours. The organic phase was washed 5 times with 3.0 liter of a saturated aqueous sodium thiosulfate solution and 3 times with 3.0 liter of water, and dried over anhydrous magnesium sulfate.
The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent: ethyl acetate / heptane = 7 /
3 (based on the volume) of the crude trans-
1,4-bis- (1,2-epoxy-n-tridecyl)
47.0 grams of cyclohexane were obtained.

Stage 3 Crude trans-1,4-bis- (1,2-epoxy-
47.0 grams of (n-tridecyl) cyclohexane (9
8.6 mmol) and 133 g (315 mmol) of dibromotriphenylphosphorane were added to 1.0 liter of toluene, and the mixture was refluxed for 5 hours under a nitrogen atmosphere. Silica gel was spread on the filter paper, filtered while hot, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography (developing solvent: heptane). The crystals were recrystallized from heptane to obtain 15.3 g of trans-1,4-bis-((E) -1,2-dibromo-n-tridecyl) cyclohexane.

Stage 4 Trans-1,4-bis-((E) -1,2-dibromo-n-tridecyl) cyclohexane 14.8 g (1
9.4 mmol), 7.61 g (116 mmol) of zinc and 150 mL of acetic acid were added to 150 mL of toluene, and the mixture was stirred at room temperature for 3 hours under a nitrogen stream.
The insolubles were removed by celite filtration, and 150 ml of water was added for liquid separation. The organic phase is 2N-sodium hydroxide 1
After washing twice with 50 ml and three times with 150 ml of water, it was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography (developing solvent: heptane) to obtain a crude product. The crude was recrystallized from heptane to give 2.19 grams of the title compound. Phase transition temperature: Cr 47.3 Iso ¹ H-NMR: δ: (ppm): 0.70 to 2.20
(M, 56H), 5.25-5.50 (m, 4H). MS: m / e = 444 (M ⁺ ), 415, 289, 13
5,67,44.

The following compounds can be prepared according to the methods of Examples 1 and 2.

[0115]

Embedded image

[0116]

Embedded image

[0117]

Embedded image

[0118]

Embedded image As the nematic liquid crystal composition containing the liquid crystal compound of the present invention thus prepared, the following composition examples (use examples 1 to 10) can be shown. However, the compounds in the composition examples are abbreviated according to the rules shown in Table 1. Further, for example, in the following partial structural formula (Formula 36), when a hydrogen atom of a trans-1,4-cyclohexylene group is substituted by a deuterium atom at positions W ¹ , W ² and W ³ , H [1D, 2D, 3D] and W
^When substituted by deuterium atoms at the positions of ⁵ , W ⁶ , and W ⁷ , the symbol H [5D, 6D, 7D] indicates the deuterium substitution position by the number in [].

[0119]

Embedded image

[0120]

[Table 1] In the composition examples (use examples), “%” indicates “% by weight” and “parts” indicate the liquid crystal composition 100 unless otherwise specified.
"Parts by weight" of the optically active compound relative to parts by weight are shown.

The measurement temperature for viscosity (η) and dielectric anisotropy (Δε) is 20.0 ° C., and the measurement temperature and wavelength for refractive index anisotropy (Δn) are 25.0 ° C. and 589 n, respectively.
The measurement temperature of m, threshold voltage (V _th ) and pitch (P) was 25.0 ° C.

[Application Example 1]

[0123]

[Table 2] [Use Example 2]

[0124]

[Table 3] [Use Example 3]

[0125]

[Table 4] [Use Example 4]

[0126]

[Table 5] [Use Example 5]

[0127]

[Table 6] [Use Example 6]

[0128]

[Table 7] [Use Example 7]

[0129]

[Table 8] [Use Example 8]

[0130]

[Table 9] [Use Example 9]

[0131]

[Table 10] [Use Example 10]

[0132]

[Table 11] [Comparative Test Example] The following liquid crystal compositions were prepared to compare the effects of image sticking. The notation was in accordance with Table 1 as in the usage example.

Composition A (comparative product)

[0134]

[Table 12] Composition B (the present invention)

[0135]

[Table 13] Each of composition A and composition B was mixed with 2.25 parts and 2.17 parts of CN as a chiral material, injected into an 8-inch cell, and the following voltage was applied to a part (4 cm × 4 cm) of the cell. And the presence or absence of burn-in was checked. The measurement conditions were 240 μm, a cell thickness of 6 μm, which was coated with a polyimide alignment film.
を Using a twist cell, applied voltage is 28V, waveform is 1 /
240 duty-1/16 bias, 70 Hz, and one frame includes 478 polarity reversal components (FIG. 1).

In the case of the composition A, burning was confirmed 2 hours after the application of the voltage. However, in the composition B containing the compound of the present invention, burning was not confirmed even after 8 hours from the application of the voltage, and burning was not confirmed even when the voltage was applied for 2 days. Therefore, it is easily understood that the composition containing the compound of the present invention is extremely useful for preventing image sticking.

[0137]

The liquid crystalline compound of the present invention, that is, a monocyclic compound having an alkenyl group at both terminals or one terminal of the molecule is useful as a compound for a liquid crystal display. 1) Since the viscosity is low, the threshold voltage is reduced and the response speed is improved. 2) It is possible to prepare a stable nematic liquid crystal composition in which no crystals are precipitated and no smectic phase is exhibited even at an extremely low temperature. 3) The effect of preventing burn-in in STN display is large. It exhibits characteristics such as the above, is stable against an external environment, and can realize a display element having a wide operating temperature range, low-voltage driving, high-speed response, and high contrast.

Therefore, a liquid crystal display device manufactured using the present liquid crystalline compound is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a waveform diagram schematically showing an applied voltage waveform in a burn-in test of a liquid crystal display element.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 4, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction contents]

Further, the present invention relates to the above [11] to [ 5 ].
A liquid crystal composition characterized by further comprising one or more optically active compounds in addition to the liquid crystal composition according to any one of [10].

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction contents]

The present invention further relates to the aforementioned [12] [ 5 ].
A liquid crystal display device comprising the liquid crystal composition according to any one of [11] to [11].

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI C07D 239/26 C07D 239/26 C09K 19/06 C09K 19/06 19/40 19/40 19/42 19/42 G02F 1/13 500 G02F 1/13 500 (72) Fusayuki Takeshita 939-5 Nakatomi, Kimitsu City, Chiba Prefecture (72) Etsuo Nakagawa 8890 Goi, Ichihara City, Chiba Prefecture

Claims (12)

[Claims] 1. A compound of the general formula (1) (Wherein ring A is trans-1,4 in which one or more carbon atoms in the cyclohexane ring may be substituted with a silicon atom.
A cyclohexylene group, a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, a pyrimidine-2,5-diyl group, a pyridine-2,5
-Diyl group, 1,3-dioxane-2,5-diyl group,
It represents a tetrahydropyran-2,5-diyl group, a 1,3-dithiane-2,5-diyl group, or a tetrahydrothiopyran-2,5-diyl group. Q ¹ and Q ² each independently represent an alkylene group having 1 to 15 carbon atoms or a single bond. Any non-adjacent methylene group (—CH ₂ —) in the alkylene group is an oxygen atom (—O—) or —CH
= CH- may be substituted. X ¹ , X ² , X
³ and X ⁴ each independently represent a hydrogen atom or a halogen atom. Y ¹ and Y ² each independently represent a hydrogen atom,
It represents a halogen atom or an alkyl group having 1 to 15 carbon atoms. Any non-adjacent methylene groups in the alkyl group may be replaced by an oxygen atom or -CH = CH-. n is 0 or 1. Each element constituting the compound includes its isotope. ). 2. Ring A is a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, and Q ¹ And the liquid crystal compound according to claim 1, wherein Q ² is a single bond. 3. Ring A is a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom,
Q ¹ is an alkylene group having 1 to 15 carbon atoms, and any non-adjacent methylene group (-C
The liquid crystal compound according to claim 1, wherein H ₂ —) may be substituted by an oxygen atom (—O—) or —CH ＝ CH—, and Q ² is a single bond. 4. Ring A is a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which one or more hydrogen atoms on a six-membered ring may be substituted with a halogen atom, and Q ¹ any methylene groups Q ² are not adjacent to one another (-
CH ₂ —) is an oxygen atom (—O—) or —CH ＝ CH—
The liquid crystal compound according to claim 1, which is an alkylene group having 1 to 15 carbon atoms which may be substituted by. 5. A liquid crystal composition comprising at least one compound represented by the general formula (1) and comprising at least two components. 6. A compound comprising at least one liquid crystalline compound according to claim 1 as a first component, and a compound represented by general formulas (2), (3) and (4) as a second component: Formula 2 (Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms. Any non-adjacent methylene groups in the alkyl group are
It may be substituted by an oxygen atom or -CH = CH-. Also, any hydrogen atom in the alkyl group may be replaced by a fluorine atom. Y ³ is a fluorine atom, a chlorine atom, OCF ₃ ,
OCF ₂ H, CF ₃ , CF ₂ H, CFH _{2 ,} OCF ₂ CF ₂ H
Or OCF ₂ CFHCF ₃ . L ¹ and L ² independently represent a hydrogen atom or a fluorine atom. Z ¹ and Z ² are each independently a 1,2-ethylene group, a vinylene group, a 1,4-butylene group, —COO—, —CF ₂ O—,
—OCF ₂ — or a single bond. Ring B is trans-
1,4-cyclohexylene group, 1,3-dioxane-
It represents a 2,5-diyl group or a 1,4-phenylene group in which a hydrogen atom may be substituted by a fluorine atom. Ring C represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group in which a hydrogen atom may be substituted by a fluorine atom. Further, each atom in each formula includes isotopes. A) a liquid crystal composition comprising at least one compound selected from the group consisting of: 7. A composition comprising at least one liquid crystal compound according to claim 1 as a first component,
As the second component, general formulas (5) and (6) (Wherein, R ² and R ³ independently of one another have 1 to 10 carbon atoms)
Represents an alkyl group. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or a vinylene group. Further, any hydrogen atom in the alkylene group may be substituted with a fluorine atom. Y ⁴ represents a CN group or a C≡C-CN group. Ring D is trans-1,
A 4-cyclohexylene group, a 1,4-phenylene group, a pyrimidine-2,5-diyl group, or a 1,3-dioxane-2,5-diyl group is shown. Ring E is trans-1,4-
A cyclohexylene group, a 1,4-phenylene group in which a hydrogen atom may be substituted by a fluorine atom, or a pyrimidine-
Represents a 2,5-diyl group. Ring F represents a trans-1,4-cyclohexylene group or a 1,4-phenylene group,
Z ³ represents a 1,2-ethylene group, —COO—, or a single bond. L ³ , L ⁴ and L ⁵ independently represent a hydrogen atom or a fluorine atom. a, b, and c each independently represent 0 or 1. Also, each atom in each formula includes isotopes. A) a liquid crystal composition comprising at least one compound selected from the group consisting of: 8. A liquid crystal display device comprising at least one liquid crystal compound according to claim 1 as a first component,
General formulas (7), (8) and (9) as the second component (Wherein, R ⁴ and R ⁵ independently of one another have 1 to 10 carbon atoms)
Represents an alkyl group. Any non-adjacent methylene groups in the alkyl group may be substituted with an oxygen atom or a vinylene group. Further, any hydrogen atom in the alkylene group may be substituted with a fluorine atom. Ring G, ring I and ring J are each independently a trans-1,4-cyclohexylene group, a pyrimidine-2,5-diyl group, or a ring in which one or more hydrogen atoms are substituted with fluorine atoms. Shows a good 1,4-phenylene group. Z ⁴ and Z ⁵ are each independently a 1,2-ethylene group, a vinylene group, —COO
—, —C≡C—, or a single bond. Further, each atom in each formula includes isotopes. A) a liquid crystal composition comprising at least one compound selected from the group consisting of: 9. As a first component, at least one kind of the liquid crystalline compound according to claim 1 is contained,
As a second component, at least one compound selected from the group consisting of the general formulas (5) and (6) is contained, and as a third component, a compound selected from the general formulas (7), (8) and (9) is used. A liquid crystal composition comprising at least one compound selected from the group consisting of: 10. The liquid crystal composition according to claim 1, wherein the first component comprises at least one liquid crystal compound according to claim 1 and the second component comprises the general formulas (2), (3) and (4). At least one compound selected from the group consisting of
At least one compound selected from the group consisting of the general formulas (5) and (6) as the third component.
Contains, as the fourth component, the general formula (7),
A liquid crystal composition comprising at least one compound selected from the group consisting of (8) and (9). 11. A liquid crystal composition comprising, in addition to the liquid crystal composition according to claim 5, one or more optically active compounds. 12. A liquid crystal display device comprising the liquid crystal composition according to claim 5. Description: