JPH08231960A - Liquid crystal composition and liquid crystal display element - Google Patents

Abstract

PURPOSE: To obtain a liquid crystal composition having high nematic isotropic phase transition point and high refractive index anisotropy and, accordingly, satisfying the characteristics required in a TN display system and an STN display system and coping with high-speed response, etc., by compounding three specific kinds of components. CONSTITUTION: This composition contains (A) a compound of formula I (R<1> and R<2> are each a 1-10C alkyl), (B) a compound selected from formula II, formula III, etc. [R<3> is a 2-10C alkenyl; R<6> is a 1-10C alkyl; (C) is trans-1,4- cyclohexylene, 1,4-phenylene, etc.] and (C) a compound selected from formula IV, formula V, etc. [R<8> and R<9> are each a 1-10C alkyl or a 2-8C alkenyl; (E) is 1,4-phenylene or pyrimidine-2,5-diyl; Z is C≡C or single bond]. The amounts of the components A, B and C are preferably 5-20wt.%, 20-70wt.% and 15-55wt.% based on the total composition, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nematic liquid crystal composition used in a closed cell formed of two substrates having a transparent electrode of an electro-optical display element and a liquid crystal display element using the liquid crystal composition. Regarding More specifically, it relates to a liquid crystal composition used in a TN (twisted nematic) display system and an STN (super twisted nematic) display system.

[0002]

2. Description of the Related Art A liquid crystal display element (LCD) utilizes the optical anisotropy and dielectric anisotropy of a liquid crystal substance, and among the liquid crystal phases, those utilizing a nematic liquid crystal phase are most practically used. ing. LCD is CRT (CRT)
Compared with other products, it can be used in handheld calculators, digital watches, etc. because of its lower power consumption, smaller size, and lighter weight, and its widespread application in word processors, TVs, in-vehicle panels, car navigation systems, etc. ing. Furthermore,
With the progress of advanced information technology in recent years, portable use of these information devices has progressed, and as a theme in the development of LCDs used for them, it is particularly desired to deal with outdoor use. In order to enable outdoor use, a liquid crystal material that responds to the drastic change in environmental temperature, that is, a liquid crystal material that exhibits a nematic liquid crystal phase in a wide temperature range centered on room temperature (especially a nematic-isotropic phase transition point (NI point) High) is strongly demanded. Further, there is also a strong demand for high-speed response to support moving images, and various studies have been made on each LCD display system.

However, at present, there is no liquid crystal material used for any of the display elements, and there are no liquid crystal compounds satisfying the properties required for a single liquid crystal compound, that is, the liquid crystal temperature range, operating voltage, responsiveness, etc. Under the present circumstances, the liquid crystal compound (1) or a non-liquid crystal compound is further mixed as necessary to satisfy various properties required and is used as a liquid crystal composition for LCD.

For example, the characteristics of the liquid crystal composition required for the TN display system are: 1) The nematic-isotropic phase transition point (NI point) is high. 2) A suitable refractive index anisotropy can be taken according to the cell thickness of the LCD. In addition to the above characteristics, 3) the voltage-transmittance curve is steep in the STN display system. Is required.

In order to obtain a liquid crystal composition having a wide nematic range that can sufficiently withstand changes in ambient temperature during outdoor use, the introduction of a liquid crystal compound having a high NI point and good compatibility with other liquid crystal compounds. Is essential. Generally, in order to increase the NI point, a compound having a large number of rings in terms of chemical structure may be used, but on the other hand, there arises a problem that the viscosity of the liquid crystal composition becomes high. That is, since the response time (τ) is proportional to the viscosity (η) of the liquid crystal material and to the square of the cell thickness d, the composition having a high viscosity lowers the response. Therefore, the use of high ring number compounds is limited.

On the other hand, in the TN display system in which the orientation of liquid crystal molecules in the upper and lower substrates is twisted at 90 °, G.Ba
Reported by uer (Crist.Liq., 63,45 (198
1)), the refractive index anisotropy (Δn) of the liquid crystal material filled in the cell in order to prevent the generation of interference fringes on the cell surface.
And the cell thickness (d) μm, Δn · d must be set to a certain value (for example, Δn · d = 0.5 or Δn · d = 1.0). Under this condition, T which has a fast response speed
In order to realize the N cell, it is necessary to use a liquid crystal material having a large Δn. The value of d can be reduced by using a liquid crystal material having a large Δn. Since the response time (τ) of the cell is proportional to η and to the square of d as described above, τ can be remarkably shortened by reducing the value of d. Therefore, a liquid crystal composition used for such a liquid crystal display device is required to have an appropriately high Δn.

Also, proposed by TJ Scheffer et al. (Appl.Phy.Lett., 45 (10), 1021 (1984)), STN display method in which the orientation of liquid crystal molecules in the upper and lower substrates is twisted at 180 to 270 °. In Fig. 2, the voltage-transmittance curve is steep, and the nematic-isotropic liquid phase transition temperature (NI
It is required to have characteristics such as high point). This STN
In the display method, since the interference color due to the birefringence effect is used as a display, the optical path length Δn · d of the birefringence is adjusted to a certain value (eg Δn · d = 0.85). . Therefore, in order to realize a cell with a high response speed in the STN system, it is necessary to reduce d by using a liquid crystal material having a large Δn, as in the case of the TN system. Therefore, as a liquid crystal composition used in the STN display system, one having an appropriately high Δn is required.

Therefore, in order to realize a cell having a wide nematic range and a high response speed, a compound having a large number of rings is used, but a liquid crystal material having a large Δn, which is sufficient to compensate for the drawback of the high viscosity, is used. Is effective. However, at present, no such liquid crystal composition is known.

A liquid crystal composition having a wide nematic range is described in, for example, Japanese Unexamined Patent Publication (Kokai) No. 58-219137, which has the general formula

Embedded image (In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 10 carbon atoms.) A liquid crystal composition containing a compound represented by the formula is disclosed. The liquid crystal composition is a nematic range. However, nothing is mentioned about having a relatively high Δn.

Although many liquid crystal compounds having various characteristics are known as compounds to be mixed with a liquid crystal composition for the purpose of exhibiting other various characteristics, the required characteristics are simultaneously well balanced. The selection of compounds to satisfy and the design of the composition ratio are not easily known to those skilled in the art in the present day when the requirements are subdivided and sophisticated according to the purpose. As described above, although liquid crystal compositions have been earnestly studied according to various purposes, under the present circumstances, new improvements are always required.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to satisfy various characteristics required for the above-mentioned TN display system and STN display system, and particularly to cope with outdoor use and high-speed response. NI point)
And to provide a liquid crystal composition having a relatively high Δn. The inventors of the present invention have intensively studied compositions using various liquid crystal compounds in order to solve these problems, and as a result, the liquid crystal composition of the present invention satisfies the above characteristics and is used for TN display elements and STN display elements. It has been found that this can be achieved if this is the case.

[0012]

The present invention will be described in detail below. The first aspect of the present invention is, as a first component, the following general formula I

[Chemical 9] (In the formula, each of R ¹ and R ² independently represents an alkyl group having 1 to 10 carbon atoms.) The compound contains at least one compound selected from the group consisting of compounds represented by the following formula: formula
II-a to e

[Chemical 10] (In the formula, R ³ represents an alkenyl group having 2 to 10 carbon atoms,
R ⁴ and R ⁵ represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and R ⁶ and R ⁷ represent an alkyl group having 1 to 10 carbon atoms. Of which any methylene group in either (-CH ₂ -) is an oxygen atom (-
It may be substituted by O-), but two or more methylene groups are not continuously substituted by oxygen atoms. Z ¹
-CH ₂ CH ₂ is -, - COO- or a single bond, Q
¹ represents H or F, (A) and (B) represent trans-1,4-cyclohexylene or 1,4-phenylene, and (C) represents trans-1,4-cyclohexylene, 1,4-. Phenylene or 1,3-dioxane-trans-2,5-diyl is shown, (D) is trans-
1,4-cyclohexylene or 1,4-phenylene is shown, and l is 0 or 1. ) Containing one or more compounds selected from the group of compounds represented by the following formulas:

[Chemical 11] (In the formula, R ⁸ and R ⁹ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.
In any case, any methylene group (-CH
_2- ) may be replaced by an oxygen atom, but two or more methylene groups are not continuously replaced by an oxygen atom. (E) is 1,4-phenylene or pyrimidine-
2,5-diyl is shown, and Z ² is -C≡C- or a single bond. )

[Chemical 12] (In the formula, R ¹⁰ represents an alkyl group having 1 to ¹⁰ carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In any of them, any methylene group (—CH ₂ —) is an oxygen atom (—O—). , But two or more methylene groups are not continuously replaced by oxygen atoms.
R ¹¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, (G) is trans-1,
4-cyclohexylene or pyrimidine-2,5-diyl is shown, and (J) is trans-1,4-cyclohexylene, 1,4-phenylene or one H at the side position may be substituted with F 1, 4-phenylene, (K) represents trans-1,4-cyclohexylene or 1,4-phenylene, Z ³ represents —CH ₂ CH ₂ —, —COO— or a single bond, and Z ⁴ represents —. C≡C-, -COO- or a single bond is shown. 1 selected from the group of compounds represented by
It relates to a liquid crystal composition, which further comprises one or more compounds.

In the second aspect of the present invention, the first component is 3 to 30% by weight and the second component is 15 to 80% by weight based on the total weight of the liquid crystal composition.
%, And the third component is 10 to 60% by weight, and relates to the liquid crystal composition described in the first invention.

The third aspect of the present invention is, in addition to the first to third components of the liquid crystal composition of the first or second aspect, as the fourth component, the general formulas V and VI.

[Chemical 13] (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and m represents 0 or 1. )

Embedded image (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms,
(L) represents trans-1,4-cyclohexylene or 1,4-phenylene, Q ³ and Q ⁴ each independently represent H or F, n represents 1 or 2, p represents 0 or 1 And Z ⁵ and Z ⁶ are each independently -COO-
Or a single bond is shown. However, when p is 0, Z ⁶ represents a single bond. And a liquid crystal composition further comprising one or more compounds selected from the group of compounds represented by

A fourth aspect of the present invention relates to the liquid crystal composition according to the third aspect, wherein the fourth component is 50% by weight or less based on the total weight of the liquid crystal composition.

In a fifth aspect of the present invention, in addition to each component of the liquid crystal composition described in any one of the first to fourth aspects of the invention, as a fifth component, a compound represented by the general formula VII or VIII is used.

[Chemical 15] (In the formula, R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. In any of them, any methylene group (( —CH ₂ —) may be replaced by an oxygen atom (—O—), but two or more methylene groups are not continuously replaced by an oxygen atom. (M) and (N) are each A liquid crystal composition further comprising one or more compounds selected from the group of compounds represented by trans-1,4-cyclohexylene and 1,4-phenylene. Regarding

A sixth aspect of the present invention relates to the liquid crystal composition according to the fifth aspect, wherein the fifth component is 50% by weight or less based on the total weight of the liquid crystal composition.

A seventh aspect of the present invention is that, in the general formulas III-a and b, R ⁸ and R ⁹ each independently represent an alkyl group, an alkoxy group or an alkoxymethyl group having 1 to 10 carbon atoms, and Z ² is A liquid crystal composition according to any one of the first to sixth inventions, which is characterized by -C≡C- or a single bond.

The eighth aspect of the present invention is that, in the general formula IV, R ¹⁰
Represents an alkyl group having 1 to 10 carbon atoms, and R ¹¹ represents 1 carbon atom.
10 relates to a liquid crystal composition according to any one of the first to seventh inventions, which represents an alkyl group or an alkoxy group.

The ninth aspect of the present invention relates to a liquid crystal display device using the liquid crystal composition described in any of the first to eighth aspects of the invention.

Each liquid crystal compound constituting the liquid crystal composition of the present invention will be described below. The compound of the general formula I constituting the first component of the present invention is a liquid crystal compound having an extremely high NI point (nematic-isotropic phase transition point) of 280 ° C. or higher and excellent stability. In addition, since it has excellent compatibility with other liquid crystal compounds, it plays an important role in increasing the NI point of the liquid crystal composition and expanding the nematic range.

The general formula II-a constituting the second component of the present invention
The following compounds can be preferably mentioned as the compounds of to e.

Embedded image

[Chemical 17] (R represents an alkyl group or an alkenyl group, R ′ represents an alkyl group, R ″ represents an alkenyl group, and [R] represents alkylene or alkenylene.)

The compounds of the general formulas II-a to e are represented by the formulas (II-a), (II-b-1), (II-c-1),
(II-c-4), (II-c-5), (II-c-6),
(II-c-7), (II-c-11), (II-d-1),
(II-d-2), (II-d-3), (II-d-4),
(II-d-5), (II-d-6), (II-e-2),
The compound represented by (II-e-3) is preferably used.

The compounds of the general formulas II-a to e have a positive dielectric anisotropy, and in particular have a large value, and are used for the purpose of lowering the threshold voltage. It is also used for the purpose of improving steepness.

The general formula III- which constitutes the third component of the present invention
As the compounds represented by a, b and IV, the following compounds can be preferably mentioned.

Embedded image

[Chemical 19]

Embedded image (R and R'each independently represent an alkyl group or an alkenyl group.)

Among these third component compounds, the compound of formula III
Examples of the compound represented by -a and b include those represented by the formula (III-a-
1), (III-a-2), (III-a-4), (III-a
Compounds represented by -5), (III-b-1) and (III-b-3) are preferably used. Examples of the compound represented by the formula (IV) include formulas (IV-1), (IV-2), (IV-5),
The compound represented by (IV-6), (IV-11) or (IV-12) is preferably used.

The compounds of the general formulas III-a, b and IV are
It is a compound whose dielectric anisotropy is negative or weak. The compound of the general formula V is mainly used for the purpose of decreasing viscosity and / or adjusting Δn. Further, the compound of the general formula VI is used for the purpose of extending the nematic range and / or adjusting Δn.

As the compounds of the general formulas V and VI constituting the fourth component of the present invention, the following compounds can be preferably mentioned.

[Chemical 21]

[Chemical formula 22] (R represents an alkyl group or an alkenyl group.)

As the compounds represented by the general formulas V and VI, the compounds represented by (V-1), (V-2) or (V-3) are preferably used. Examples of the compound represented by the formula (VI) include (VI-1), (VI-5), (VI-6),
(VI-9), (VI-10), (VI-11), (VI-1
2), (VI-13), (VI-14), (VI-15),
The compounds represented by (VI-16) and (VI-17) are preferably used.

The compounds of the general formulas V and VI have a positive dielectric anisotropy and a large value, and are used for the purpose of reducing the threshold voltage. In addition, it is also used for the purpose of adjusting Δn and expanding the nematic range.

As the compounds of the general formulas VII and VIII constituting the fifth component of the present invention, the following compounds can be preferably mentioned.

[Chemical formula 23]

[Chemical formula 24] (R and R'each independently represent an alkyl group or an alkenyl group.)

Of these compounds, the compound represented by the formula VII is preferably the compound represented by the formula (VII-2), and the compound represented by the formula VIII is represented by the formula (VIII-
1), (VIII-2) and (VIII-4) are more preferably used.

The compounds of the general formulas VII and VIII are compounds having negative or weak dielectric anisotropy. General formula VI
The compounds of I and VIII mainly reduce the viscosity and / or Δ
n Used for the purpose of adjustment.

The amount of the first component (the compound represented by the general formula I) used in the present invention is such that a wide nematic range, which is the subject of the present invention, is obtained with respect to the total weight of the liquid crystal composition. Is preferably 3% by weight or more, and is preferably 30% by weight or less from the viewpoint of suppressing the viscosity within an appropriate range. It is more preferably in the range of 5 to 20% by weight.

The amount of the second component (compounds represented by the general formulas II-a to e) used is 15 from the viewpoint of suppressing the threshold voltage of the liquid crystal composition to be low with respect to the total weight of the liquid crystal composition.
High NI by weight is preferable, and high NI expressed by other components
Point, from the viewpoint of sufficiently achieving the effect of high Δn, 80
It is preferably not more than wt%. It is more preferably in the range of 20 to 70% by weight.

The amount of the third component (compounds represented by the general formulas III-a, b and IV) is such that the effect of the high NI point and the high Δn is sufficient with respect to the total weight of the liquid crystal composition. From the viewpoint, 10% by weight or more is preferable, and from the viewpoint of suppressing the viscosity within an appropriate range, 60% by weight or less is preferable. It is more preferably in the range of 15 to 55% by weight.

When the fourth component (compounds represented by the general formulas V and VI) is used, the amount used is such that it has a high NI point and a high Δn expressed by the other components with respect to the total weight of the liquid crystal composition. From the viewpoint of achieving sufficient effect, it is preferably 50% by weight or less. More preferably, it is in the range of 45% by weight or less.

The amount of the fifth component (compounds represented by the general formulas VII and VIII) used is such that the high NI point expressed by the other components,
From the viewpoint of sufficiently achieving the effect of high Δn, 50% by weight or less is preferable. More preferably, it is in the range of 45% by weight or less.

The liquid crystal composition of the present invention has a threshold voltage, a nematic range, Δn, other than the compounds represented by the above formulas I to VIII, depending on the purpose of the liquid crystal display device to be used.
For the purpose of adjusting the dielectric anisotropy, viscosity, etc., other compounds may be contained in appropriate amounts within the range not impairing the purpose of the present invention. The following compounds can be mentioned as an example of such a compound.

[Chemical 25] (R and R'represent an alkyl group.)

The liquid crystal compositions used according to the invention are prepared in a manner which is conventional per se. Generally, a method of dissolving various components with each other at a high temperature is adopted. Further, the liquid crystal material of the present invention is improved and optimized according to the intended use by appropriate additives. Such additives are well known to those skilled in the art, and are described in detail in the literature and the like. Usually, a chiral dopant or the like is added in order to induce a helical structure of liquid crystal to adjust a necessary twist angle and prevent reverse twist.

Further, the liquid crystal composition used according to the present invention is a guest obtained by adding a dichroic dye such as merocyanine type, styryl type, azo type, azomethine type, azoxy type, quinophthalone type, anthraquinone type and tetrazine type. It can also be used as a liquid crystal composition for the host (GH) mode.
Alternatively, NCAP manufactured by encapsulating nematic liquid crystal or polymer network liquid crystal display device (PNLCD) in which three-dimensional network polymer is manufactured in liquid crystal
Polymer dispersed liquid crystal display device (PNLC
It can also be used as a liquid crystal composition for D). In addition, it can be used as a liquid crystal composition for a birefringence control (ECB) mode or a dynamic scattering (DS) mode.

[0042]

EXAMPLES The present invention is described in detail below with reference to examples, but the present invention is not limited to these examples. Further, the composition ratios of Comparative Examples and Examples are all shown by weight%.

Comparative Example

[Chemical formula 26] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 60.4 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 22.8 (mP).
a · s), Δε = 11.5, V _th = 1.54 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.120.

Example 1

[Chemical 27]

[Chemical 28] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 99.3 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 20.3 (mP).
a · s), Δε = 7.8, V _th = 2.07 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.142. This liquid crystal composition had a higher NI point and a higher Δn than the comparative example.

Example 2

[Chemical 29] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 91.0 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 18.3 (mP).
a · s), Δε = 7.3, V _th = 1.97 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.160. This liquid crystal composition had a higher NI point and a higher Δn than the comparative example.

Example 3

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 92.4 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 28.2 (mP).
a · s), Δε = 11.1, V _th = 1.65 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.142. This liquid crystal composition had a higher NI point and a higher Δn than the comparative example.

Example 4

[Chemical 31]

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 112.0 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 21.2 (m
Pa · s), Δε = 6.4, V _th = 2.33 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.165.

Example 5

[Chemical 33]

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 126.3 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 32.1 (m).
Pa · s), Δε = 8.9, V _th = 1.95 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.151.

Example 6

Embedded image

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 104.0 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 40.0 (m
Pa · s), Δε = 6.2, V _th = 2.43 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.198.

Example 7

Embedded image

[Chemical 38] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 82.4 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 23.1 (mP).
a · s), Δε = 11.2, V _th = 1.46 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.128.

Example 8

[Chemical Formula 39]

[Chemical 40] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 125.6 (° C.), the viscosity at 20 ° C., the dielectric anisotropy and the threshold voltage are respectively η ₂₀ = 24.4 (m).
Pa · s), Δε = 7.1, V _th = 2.42 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.146.

Example 9

Embedded image

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 102.5 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 20.5 (m).
Pa · s), Δε = 7.7, V _th = 2.08 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.123.

Example 10

[Chemical 43] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 101.8 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 21.8 (m).
Pa · s), Δε = 7.0, V _th = 2.10 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.142.

Example 11

[Chemical 44]

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 123.0 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 34.3 (m).
Pa · s), Δε = 9.7, V _th = 2.02 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.142.

Example 12

Embedded image

[Chemical 47] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 105.8 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 21.3 (m
Pa · s), Δε = 6.1, V _th = 2.30 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.148.

Example 13

Embedded image

[Chemical 49] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 112.4 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 40.3 (m
Pa · s), Δε = 19.0, V _th = 1.39 (V), and the refractive index anisotropy at 25 ° C. is Δn = 0.150.
Met.

Example 14

Embedded image

[Chemical 51] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 112.7 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 24.0 (m).
Pa · s), Δε = 5.8, V _th = 2.40 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.123.

Example 15

Embedded image

Embedded image A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 113.0 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 34.5 (m).
Pa · s), Δε = 5.0, V _th = 2.43 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.138.

Example 16

[Chemical 54]

[Chemical 55] A liquid crystal composition was prepared. The clearing point of this liquid crystal composition is T _NI = 101.4 (° C.), the viscosity at 20 ° C., the dielectric anisotropy, and the threshold voltage are respectively η ₂₀ = 17.6 (m).
Pa · s), Δε = 3.9, V _th = 2.68 (V), and the refractive index anisotropy at 25 ° C. was Δn = 0.124.

[0060]

INDUSTRIAL APPLICABILITY As shown in Examples and Comparative Examples, the present invention makes it possible to prepare liquid crystal compositions having a high NI point and a relatively high Δn. Therefore, it is possible to provide a liquid crystal composition which is particularly suitable for outdoor use and high-speed response while satisfying various characteristics required for the liquid crystal composition of the TN display system and the SBE display system.

Claims (9)

[Claims] 1. As a first component, the following general formula I: (In the formula, each of R ¹ and R ² independently represents an alkyl group having 1 to 10 carbon atoms.) Contains at least one compound selected from the group consisting of compounds represented by the following formula: Formulas II-a to e: (In the formula, R ³ represents an alkenyl group having 2 to 10 carbon atoms,
R ⁴ and R ⁵ represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and R ⁶ and R ⁷ represent an alkyl group having 1 to 10 carbon atoms. Of which any methylene group in either (-CH ₂ -) is an oxygen atom (-
It may be substituted by O-), but two or more methylene groups are not continuously substituted by oxygen atoms. Z ¹
-CH ₂ CH ₂ is -, - COO- or a single bond, Q
¹ represents H or F, (A) and (B) represent trans-1,4-cyclohexylene or 1,4-phenylene, and (C) represents trans-1,4-cyclohexylene, 1,4-. Phenylene or 1,3-dioxane-trans-2,5-diyl is shown, (D) is trans-
1,4-cyclohexylene or 1,4-phenylene is shown, and l is 0 or 1. ) Containing one or more compounds selected from the group consisting of compounds represented by the following formulas: (In the formula, R ⁸ and R ⁹ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 8 carbon atoms.
In any case, any methylene group (-CH
_2- ) may be replaced by an oxygen atom, but two or more methylene groups are not continuously replaced by an oxygen atom. (E) is 1,4-phenylene or pyrimidine-
2,5-diyl is shown, and Z ² is -C≡C- or a single bond. ) [Chemical 4] (In the formula, R ¹⁰ represents an alkyl group having 1 to ¹⁰ carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In any of them, any methylene group (—CH ₂ —) is an oxygen atom (—O—). , But two or more methylene groups are not continuously replaced by oxygen atoms.
R ¹¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, (G) is trans-1,
4-cyclohexylene or pyrimidine-2,5-diyl is shown, and (J) is trans-1,4-cyclohexylene, 1,4-phenylene or one H at the side position may be substituted with F 1, 4-phenylene, (K) represents trans-1,4-cyclohexylene or 1,4-phenylene, Z ³ represents —CH ₂ CH ₂ —, —COO— or a single bond, and Z ⁴ represents —. C≡C-, -COO- or a single bond is shown. 1 selected from the group of compounds represented by
A liquid crystal composition, which further comprises one or more compounds. 2. The first component is 3 relative to the total weight of the liquid crystal composition.
The liquid crystal composition according to claim 1, wherein the second component is 15 to 80% by weight, and the third component is 10 to 60% by weight. 3. In addition to the first to third components of the liquid crystal composition according to claim 1 or 2, as a fourth component, a compound represented by the general formula V or VI: (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and m represents 0 or 1. ) [Chemical 6] (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms,
(L) represents trans-1,4-cyclohexylene or 1,4-phenylene, Q ³ and Q ⁴ each independently represent H or F, n represents 1 or 2, p represents 0 or 1 And Z ⁵ and Z ⁶ are each independently -COO-
Or a single bond is shown. However, when p is 0, Z ⁶ represents a single bond. ) A liquid crystal composition further comprising one or more compounds selected from the group of compounds represented by 4. The fourth component is 5 relative to the total weight of the liquid crystal composition.
The liquid crystal composition according to claim 3, which is 0% by weight or less. 5. In addition to each component of the liquid crystal composition according to any one of claims 1 to 4, as a fifth component, a compound represented by the general formula VII or VIII: (In the formula, R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. In any of them, any methylene group (( —CH ₂ —) may be replaced by an oxygen atom (—O—), but two or more methylene groups are not continuously replaced by an oxygen atom. (M) and (N) are each A liquid crystal composition further comprising one or more compounds selected from the group of compounds represented by trans-1,4-cyclohexylene and 1,4-phenylene. . 6. The liquid crystal composition according to claim 5, wherein the fifth component is 50% by weight or less based on the total weight of the liquid crystal composition. 7. R ⁸ and R in the general formulas III-a and b.
⁹ each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, and Z ² is -C≡.
7. A C- or a single bond is shown.
The liquid crystal composition according to any one of items 1. 8. In the general formula IV, R ¹⁰ has 1 to ¹⁰ carbon atoms.
The alkyl group of R 1 is represented by R ¹¹ , and R ¹¹ represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms.
8. The liquid crystal composition according to any one of items 7 to 7. 9. A liquid crystal display device using the liquid crystal composition according to claim 1.