JPH0959635A - Liquid crystal composition and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liq. crystal compsn. which has characteristics meeting the requirements for TN-LCD and STN-LCD display methods and has an esp. wide range of nematic liq. crystal phase. SOLUTION: This compsn. contains at least one compd. represented by formula I as the first component and at least one compd. represented by formula II as the second component. In those formulas R<0> and R<1> are each independently a 1-10C alkyl or 2-10C alkenyl provided any one methylene group or nonadiacent two or more methylene groups may be substd. with an oxygen atom or atoms; and A<0> is a phenylene group optionally having one H atom at the side position on replaced with F.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a nematic liquid crystal composition containing at least one kind of chiral additive and a liquid crystal composition provided in a closed cell formed of two substrates having transparent electrodes. The present invention relates to a liquid crystal display element used. More specifically, it relates to a liquid crystal composition suitable for a twist nematic (TN) system or a super twist birefringence (STN) system and a liquid crystal display device using the liquid crystal composition.

[0002]

2. Description of the Related Art Twisted nematic (TN), supertwisted birefringence (STN), and active matrix (AM) are known as liquid crystal display devices (LCD).
-LCD) method and the like have been proposed and have been put into practical use one after another. Among them, the following characteristics are commonly required for the liquid crystal compositions used for the TN and STN mode liquid crystal display elements. (1) exhibit a nematic liquid crystal phase in a wide temperature range including room temperature. Especially the nematic-isotropic phase transition temperature (clearing point)
Is high. (2) The threshold voltage must be low in order to reduce power consumption. (3) To minimize the response time (τ),
Low viscosity (η). (4) An appropriate refractive index anisotropy (Δ
n). (5) Be chemically stable. In recent years, there has been a strong demand for the LCD to support moving images. In order to support moving images, the response speed when driving the LCD must be low. Since the response speed is proportional to the viscosity of the liquid crystal composition, development of a liquid crystal composition having a small viscosity is required. Further, since the LCD can be driven by a battery, the development of LCDs for outdoor use has been promoted. For more reliable outdoor use, the nematic liquid crystal phase range needs to be further expanded. However, although such a liquid crystal composition has been intensively studied, at present, it is always required to be improved. Carboxyl group (-COOH) at the end
The compound having is dimerization
n) and develops liquid crystallinity (DD
emus, Flussige Kristale i
n Tabellen, 57 (1974)). As an application of such a compound having a carboxyl group, JP-A-54-151951 discloses a liquid crystal composition using an alkylcyclohexylcarboxylic acid. However, although the use of alkylcyclohexylcarboxylic acid can reduce the viscosity of the liquid crystal composition, it has a drawback that the compatibility is poor especially at low temperatures and the nematic liquid crystal phase range is small. In addition, Japanese Unexamined Patent Publication No.
Japanese Patent No. 57252 discloses a liquid crystal composition using an alkylbenzoic acid or an alkoxybenzoic acid. Although these benzoic acids can lower the viscosity of the liquid crystal composition and increase Δn, they also have the drawback that they have poor compatibility at low temperatures and the nematic liquid crystal phase range cannot be increased.

[0003]

The present inventors have found that a liquid crystal composition satisfying these characteristics can be prepared by combining various different compounds having a carboxyl group. That is, probably because the dimerization of different kinds occurs due to the combination of these compounds having different carboxyl groups, intermediate physical properties (for example, refractive index anisotropy) can be expressed as compared with the case of the combination of the same kind of simple substance. It has been discovered that the physical properties can be adjusted by changing the mixing ratio of compounds having different carboxyl groups. Further, the inventors have found that the compatibility at low temperature is improved probably because the number of kinds of dimers increases due to the combination of different carboxylic acid compounds, and the present invention has been completed. As is clear from the above description, an object of the present invention is to provide a liquid crystal composition having a wide nematic liquid crystal phase range while satisfying various characteristics required for the TN-LCD and STN-LCD display systems. .

[0004]

The present invention has the following first to tenth configurations. A first invention of the present invention is characterized by containing at least one compound of the general formula (Ia) as a first component and at least one compound of (Ib) as a second component. And a liquid crystal composition.

Embedded image

Embedded image (In the formula, R ⁰ and R ¹ each independently have 1 to 10 carbon atoms.
Or an alkenyl group having 2 to 10 carbon atoms. Any one or non-adjacent two or more methylene groups also in groups in either (-CH ₂ -) may be replaced by oxygen atom (-O-). A ⁰ is the side 1
One H represents a phenylene group which may be substituted with F. ) A second aspect of the present invention provides a compound of the general formula (II) as the third component.
The liquid crystal composition according to the first invention, characterized in that it contains at least one or more nitrile compounds having a terminal group structure.

Embedded image (L ¹ and L ² each independently represent H or F.) In the third invention of the present invention, the compound of the general formula (II) is represented by the general formula (II-a), (II-b). , (II-c), (II-d)
Or (II-e)

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Embedded image

[Chemical 21]

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Embedded image (In the formula, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In either case, any one of the groups or two or more non-adjacent methylene groups (-CH ₂ -) -COO is good .Z ³ be replaced by oxygen atom _{(-O-) -, - C 2} H 4 - or a single bond, Z ⁴ and Z ⁵ -C ₂ H ₄ - or Represents a single bond, Z ⁶ represents —COO—, —C ₂ H ₄ — or a single bond, and B ¹ represents a trans 1,4-cyclohexylene group, a phenylene group or a 1,3-dioxa-2,5 len group. And B ² , B ³ , B ⁴ , B ⁶ and B ⁷ each independently represent a trans 1,4-cyclohexylene group or a phenylene group, and B ⁵ represents a trans 1,4-cyclohexylene group or a lateral position. H of 1 represents a phenylene group which may be substituted with F, and q and m relates to a liquid crystal composition according to each independently represents 0 or 1.) the first or second invention, characterized in that a compound represented by. A fourth invention of the present invention is characterized in that the first component is 3 to 40%, the second component is 3 to 40%, and the third component is 5 to 80% with respect to the total weight of the liquid crystal composition. And a liquid crystal composition according to the second or third invention. A fifth aspect of the present invention provides a compound represented by the general formula (III) or (IV) as the fourth component.
And (V)

Embedded image (In the formula, R ⁶ and R ⁷ each independently have 1 to 10 carbon atoms.
Or an alkenyl group having 2 to 10 carbon atoms. In any case, any one of the groups or two or more non-adjacent methylene groups (—CH ₂ —) may be replaced by an oxygen atom. C represents a trans 1,4-cyclohexylene group, 2,4-pyrimidinylene group or phenylene group, D represents a trans 1,4-cyclohexylene group or phenylene group, Z ⁷ represents —C≡C—, —C
_{OO -, - C 2 H 4} -, or an -CH = CH- or a single bond. )

Embedded image (In the formula, R ⁸ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In either case, any one of the groups or two or more non-adjacent methylene groups (-CH _2- ) may be substituted by an oxygen atom (—O—), R ⁹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, and E is a trans 1,4-cyclohexylene group or Represents a 2,4-pyrimidinylene group, G represents a trans 1,4-cyclohexylene group or a phenylene group in which one H at the side position may be substituted with F, and J represents a trans 1,4-cyclohexylene group or indicates a phenylene group, Z ⁸ is -C ₂ H ₄ -,
Represents --COO-- or a single bond, and Z ⁹ represents --C≡C--,-
COO-, -CH = CH- or a single bond is shown. )

[Chemical formula 26] (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 either case, any one of the groups or two or more non-adjacent methylene groups (-CH _2- ) may be substituted by an oxygen atom (—O—), R ¹¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, and Q ¹ represents H or F). The liquid crystal composition according to any one of the first to fourth inventions, further comprising at least one compound selected from the group of represented compounds. The sixth invention of the present invention is, as the fourth component,
General formulas (VI) and (VII)

Embedded image (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and k represents 0 or 1. )

Embedded image (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms, and K
Represents a trans 1,4-cyclohexylene group or a phenylene group, and Q ³ and Q ⁴ are each independently H or F.
And Z ¹⁰ and Z ¹¹ are each independently -COO-,-
C ₂ H ₄ − or a single bond is shown, and h is 0, 1 or 2. X represents F or Cl. The present invention also relates to the liquid crystal composition according to any one of the first to fourth inventions, which further comprises at least one compound selected from the group consisting of: In a seventh aspect of the present invention, the content of the fourth component is 70% with respect to the total weight of the liquid crystal composition.
The present invention relates to the liquid crystal composition according to the fifth or sixth invention, characterized in that: An eighth aspect of the present invention is
Furthermore, as the fifth component, general formulas (VI) and (VII)

[Chemical 29] (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and k represents 0 or 1. )

Embedded image (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms, and K
Represents a trans 1,4-cyclohexylene group or a phenylene group, and Q ³ and Q ⁴ are each independently H or F.
And Z ¹⁰ and Z ¹¹ are each independently -COO-,-
C ₂ H ₄ − or a single bond is shown, and h is 0, 1 or 2. X represents F or Cl. The present invention relates to a liquid crystal composition according to any one of the first to sixth inventions, which contains at least one compound selected from the group consisting of: The ninth invention of the present invention is characterized in that the total content of the fourth component and the fifth component is 70% or less with respect to the total weight of the liquid crystal composition.
The invention relates to a liquid crystal composition according to any one of the inventions. A tenth invention of the present invention relates to a liquid crystal display device using the liquid crystal composition according to any one of the first to ninth inventions.

The liquid crystal compounds constituting the liquid crystal composition of the present invention will be described below. As the compound represented by the general formula (Ia), which is the first component of the present invention, the following compounds can be preferably exemplified.

[0006]

[Chemical 31]

(R represents an alkyl group or an alkenyl group.) Among these compounds, the compounds of the general formulas (Ia-1) to (I-) are low in viscosity and good in compatibility at low temperature. a
The compound (3) is particularly preferably used in the present invention.

The second component of the present invention, the general formula (I-
Preferred examples of the compound represented by b) include the following compounds.

[0009]

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(R represents an alkyl group or an alkenyl group.) Among these compounds, the compounds of the general formulas (Ib-1) to (I-I) have low viscosity and good compatibility at low temperature. b
The compound (3) is particularly preferably used in the present invention.

By dimerizing the compounds of the general formulas (Ia) and (Ib), the dielectric anisotropy Δε is | Δ.
The characteristic of the bicyclic liquid crystal compound with ε | <5 is exhibited. Therefore, it exhibits an excellent effect particularly in reducing the viscosity of the liquid crystal composition. Probably because of the combination of these different carboxylic acid compounds, dimerization of different kinds occurs, and as a result, intermediate physical properties such as refractive index anisotropy (Δn) can be expressed. Therefore, Δn can be adjusted by changing the mixing ratio of the compounds of the general formulas (Ia) and (Ib). Also, the compatibility at low temperature is improved, probably because the number of kinds of dimers increases due to the combination of different carboxylic acid compounds.

The third component of the present invention, the general formula (II-
a), (II-b), (II-c), (II-d) and (II
As the compound represented by -e), the following compounds can be preferably exemplified.

[0013]

[Chemical 33]

[0014]

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[0015]

Embedded image

(R is an alkyl group or an alkenyl group,
R'represents alkanediyl or alkenediyl. ) Among these compounds, among formulas (II-a-1) and (II-
a-2), (II-a-3), (II-a-4), (II-a
-5), (II-a-8), (II-b-1), (II-b-
2), (II-b-3), (II-c-1), (II-c-
4), (II-c-5), (II-c-6), (II-c-
9), (II-c-10), (II-c-11), (II-d
-1), (II-d-2), (II-e-1) or (II-
The compound represented by e-2) is particularly preferably used in the present invention.

The compound of the third component is a compound having a positive dielectric anisotropy and its value is particularly large, and is mainly used for the purpose of reducing the threshold voltage and improving the steepness which is important as STN characteristics. It These compounds having a large dielectric anisotropy are indispensable components for voltage driving.

The compounds represented by the general formulas (III), (IV) and (V) as the fourth component are preferably the following compounds.

[0019]

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[0020]

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[0021]

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[0022]

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(R and R'independently represent an alkyl group or an alkenyl group.) Of these, the compounds represented by the formula (III) include compounds represented by the formulas (III-1) and (III-2). ), (III-4), (III-
5), (III-6), (III-7), (III-8),
(III-10), (III-13), (III-14),
The compound represented by (III-18) or (III-19) is particularly preferably used in the present invention. Further, as the compound represented by the formula (IV), compounds represented by the formulas (IV-1) and (IV
-2), (IV-5), (IV-6), (IV-8), (IV-
The compounds represented by 9), (IV-11), (IV-12), (IV-14) or (IV-15) are particularly preferably used in the present invention. As the compound represented by the formula (V), the compound represented by (V-2) or (V-3) is particularly preferably used in the present invention. The compounds of the general formulas (III), (IV) and (V) of the fourth component are compounds having a negative or weak positive dielectric anisotropy. The compound of the general formula (III) is mainly used for the purpose of decreasing viscosity and / or adjusting Δn. In addition, the compound of the general formula (IV) is used for the purpose of broadening the nematic range such as increasing the clearing point and /
Alternatively, it is used for the purpose of adjusting Δn and adjusting viscosity.

The compounds represented by the general formulas (VI) and (VII) used as the fourth component or the fifth component of the present invention are preferably the following compounds.

[0025]

[Chemical 40]

[0026]

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[0027]

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[0028]

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[0029]

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(R represents an alkyl group.) The compound represented by the general formula (VI) is represented by the formula (VI-
The compound represented by 1), (VI-2) or (VI-3) is particularly preferably used in the present invention. Further, as the compound represented by the general formula (VII), a compound represented by the formula (VII-1),
(VII-5), (VII-6), (VII-7), (VII-
8), (VII-9), (VII-10), (VII-1)
1), (VII-12), (VII-13), (VII-1)
4), (VII-15), (VII-16), (VII-1)
7), (VII-18), (VII-19), (VII-2)
0), (VII-22), (VII-29), (VII-3)
4), (VII-35), (VII-37), (VII-4)
The compound represented by 1), (VII-47) or (VII-48) is particularly preferably used in the present invention. The compounds of the general formulas (VI) to (VII) are compounds having a positive dielectric anisotropy, and are used particularly for the purpose of reducing the threshold voltage and improving the temperature dependence thereof. Also, viscosity adjustment,
It is also used for the purpose of widening the nematic range by adjusting Δn and increasing the clearing point.

The amount of the first component used in the present invention is
It is preferably 3 to 40% with respect to the total weight of the liquid crystal composition. More preferably, it is 5 to 30%. If it is less than 3%, it is difficult to obtain the effect of the nematic liquid crystal phase range, which is the subject, and 40
%, The threshold voltage of the liquid crystal composition increases, which is not preferable. The amount of the second component used is preferably 3 to 40%. More preferably, it is 5 to 30%. If it is less than 3%, it is difficult to obtain the effect of the subject matter of the present invention that the nematic liquid crystal phase range of the liquid crystal composition is increased, and if it exceeds 40%, the threshold voltage of the liquid crystal composition becomes high, which is not preferable. The amount of the third component used is preferably 5 to 80%. More preferably, it is 10 to 75%. If it is less than 5%, the threshold voltage of the liquid crystal composition becomes large, which is not preferable. If it exceeds 80%, the viscosity of the liquid crystal composition increases, which is not preferable. The amount of the fourth component and the total amount of the fourth and fifth components used are 70
It is preferably not more than wt%. It is more preferably 65% by weight or less.

In addition to the compounds represented by the above general formulas (I) to (VII), the liquid crystal composition of the present invention has a threshold voltage, a nematic range, and Δn depending on the purpose of the liquid crystal display device 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 object of the present invention.

The liquid crystal compositions used according to the invention are prepared in a manner which is conventional in itself. Generally, a method of dissolving various components at a high temperature is used. 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. Normally, the spiral structure of the liquid crystal is induced to adjust the required twist angle, and the reverse twist
chiral dope material (chira)
l dotant) or the like is added. The liquid crystal composition used in accordance with the present invention may be added with a dichroic dye such as a merocyanine, styryl, azo, azomethine, azoxy, quinophthalone, anthraquinone or tetrazine dye to add a guest host (GH) ) It can also be used as a liquid crystal composition for a mode. Alternatively, a liquid crystal composition for a polymer dispersed liquid crystal display device (PNLCD) represented by NCAP produced by encapsulating nematic liquid crystal in a microcapsule or a polymer network liquid crystal display device (PNLCD) produced by producing a three-dimensional network polymer in the liquid crystal. It can also be used as a thing. In addition, it can be used as a liquid crystal composition for a birefringence control (ECB) mode or a dynamic scattering (DS) mode.

[0034]

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 compositional ratios of Comparative Examples and Examples are all expressed in% by weight or parts by weight. In the example, the voltage when the brightness reaches 10% is taken as the threshold voltage and is shown as V ₁₀ . Also,
Low temperature compatibility is 0 ° C, -5 ° C, -10 ° C, -20 ° C, -3
The liquid crystal composition was allowed to stand in each freezer at 0 ° C. for 7 days, and the liquid crystal phase was evaluated.

Comparative Example 1 The following composition disclosed in Example 2 of JP-A-6-57252 was prepared.

[0036]

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The clearing point of this composition is T _NI = 76.5
(° C), the viscosity at 20 ° C is η ₂₀ = 22.3 (mPa
.S), the refractive index anisotropy at 25 ° C. is Δn = 0.13.
The threshold voltage at 2, 25 ° C. is V ₁₀ = 1.65
(V), T _SN <0 ° C.

Comparative Example 2 The following composition disclosed in Mix 2 of JP-A-54-151951 was prepared.

[0039]

Embedded image

The clearing point of this composition is T _NI = 67.6.
(° C), the viscosity at 20 ° C is η ₂₀ = 55.7 (mPa
.S), the refractive index anisotropy at 25 ° C. is Δn = 0.16.
The threshold voltage at 9 and 25 ° C. is V ₁₀ = 1.56
(V), T _SN <0 ° C.

Example 1

[0042]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 74.4 (° C.), the viscosity at 20 ° C. is η ₂₀ = 22.0 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.121,25. threshold voltage at ° C. was _{V 10 = 1.64 (V),} T SN <-20 ℃. The nematic liquid crystal phase range was expanded by about 20 ° C. as compared with the liquid crystal composition of Comparative Example 1. Further, the viscosity and the threshold voltage did not change significantly, but Δn decreased.

Embodiment 2

[0045]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 71.1 (° C.), the viscosity at 20 ° C. is η ₂₀ = 22.4 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.111,25. threshold voltage at ° C. was _{V 10 = 1.63 (V),} T SN <-20 ℃. The nematic liquid crystal phase range was expanded by about 20 ° C. as compared with the liquid crystal composition of Comparative Example 1. Further, the viscosity and the threshold voltage did not change significantly, but Δn decreased. Further, as compared with the composition of Example 1, the nematic liquid crystal phase range, the viscosity,
Although the threshold voltage did not change significantly, Δn decreased. From this, it is understood that the combination of the first component and the second component increases the nematic liquid crystal phase range, and the physical properties such as Δn can be adjusted by changing the mixing ratio of the first component and the second component.

Example 3

[0048]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 71.0 (° C.), the viscosity at 20 ° C. is η ₂₀ = 51.3 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.183, 25. The threshold voltage at ° C was V ₁₀ = 1.57 (V) and T _SN <0 ° C.
Compared to the liquid crystal composition of Comparative Example 2, the nematic liquid crystal phase range was widened. Although the threshold voltage did not change significantly, the viscosity decreased and Δn increased.

Example 4

[0051]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 75.6 (° C.), the viscosity at 20 ° C. is η ₂₀ = 48.6 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.137, 25. threshold voltage at ° C. was _{V 10 = 1.36 (V),} T SN <-20 ℃. The nematic liquid crystal phase range was larger than that of the liquid crystal compositions of Comparative Examples 1 and 2.

Example 5

[0054]

[Chemical 51]

[0055]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 73.4 (° C.), the viscosity at 20 ° C. is η ₂₀ = 43.3 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.161,25. threshold voltage at ° C. was _{V 10 = 1.18 (V),} T SN <-10 ℃. The nematic liquid crystal phase range was larger than that of the liquid crystal compositions of Comparative Examples 1 and 2.

Example 6

[0058]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 80.8 (° C.), the viscosity at 20 ° C. is η ₂₀ = 31.6 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.141, 25. threshold voltage at ° C. was _{V 10 = 1.38 (V),} T SN <-30 ℃.

Example 7

[0061]

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[0062]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 76.8 (° C.), the viscosity at 20 ° C. is η ₂₀ = 29.9 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.120, 25. threshold voltage at ° C. was _{V 10 = 1.67 (V),} T SN <-30 ℃.

Example 8

[0065]

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[0066]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 79.6 (° C.), the viscosity at 20 ° C. is η ₂₀ = 31.5 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.124, 25. threshold voltage at ° C. was _{V 10 = 2.18 (V),} T SN <-30 ℃.

Example 9

[0069]

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[0070]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 98.0 (° C.), the viscosity at 20 ° C. is η ₂₀ = 20.9 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.093,25. threshold voltage at ° C. was _{V 10 = 2.67 (V),} T SN <-30 ℃.

Example 10

[0073]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 80.0 (° C.), the viscosity at 20 ° C. is η ₂₀ = 30.6 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.148, 25. threshold voltage at ° C. was _{V 10 = 1.53 (V),} T SN <-30 ℃.

Example 11

[0076]

[Chemical formula 61]

A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 108.1 (° C.), the viscosity at 20 ° C. is η ₂₀ = 25.2 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.137, 25. threshold voltage at ° C. was _{V 10 = 1.73 (V),} T SN <-30 ℃.

Example 12

[0079]

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A liquid crystal composition consisting of was prepared. The clearing point of this composition is T _NI = 102.8 (° C.), the viscosity at 20 ° C. is η ₂₀ = 19.8 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.121,25. threshold voltage at ° C. was _{V 10 = 2.42 (V),} T SN <-30 ℃.

Example 13

[0082]

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[0083]

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A liquid crystal composition of was prepared. The clearing point of this composition is T _NI = 103.5 (° C.), the viscosity at 20 ° C. is η ₂₀ = 58.7 (mPa · s), and the refractive index anisotropy at 25 ° C. is Δn = 0.144, 25. threshold voltage at ° C. was _{V 10 = 1.32 (V),} T SN <-10 ℃.

[0085]

INDUSTRIAL APPLICABILITY As shown in the examples, the present invention can provide a liquid crystal composition having a wide nematic liquid crystal phase range while satisfying various characteristics used in TN-LCD and STN-LCD display systems.

Claims (10)

[Claims] 1. A first component containing at least one compound of the formula (Ia), and a second component (I-).
A liquid crystal composition comprising at least one compound of b). Embedded image Embedded image (In the formula, R ⁰ and R ¹ each independently have 1 to 10 carbon atoms.
Or an alkenyl group having 2 to 10 carbon atoms. Any one or non-adjacent two or more methylene groups also in groups in either (-CH ₂ -) may be replaced by oxygen atom (-O-). A ⁰ is the side 1
One H represents a phenylene group which may be substituted with F. ) 2. The liquid crystal composition according to claim 1, which contains at least one or more nitrile compounds having a terminal group structure represented by the general formula (II) as a third component. Embedded image (L ¹ and L ² each independently represent H or F.) 3. A compound of the general formula (II) is a compound of the general formula (II-
a), (II-b), (II-c), (II-d) or (II
-E) Embedded image [Chemical 6] [Chemical 7] Embedded image (In the formula, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In either case, any one of the groups or two or more non-adjacent methylene groups (-CH ₂ -) -COO is good .Z ³ be replaced by oxygen atom _{(-O-) -, - C 2} H 4 - or a single bond, Z ⁴ and Z ⁵ -C ₂ H ₄ - or Represents a single bond, Z ⁶ represents —COO—, —C ₂ H ₄ — or a single bond, and B ¹ represents a trans 1,4-cyclohexylene group, a phenylene group or a 1,3-dioxa-2,5 len group. And B ² , B ³ , B ⁴ , B ⁶ and B ⁷ each independently represent a trans 1,4-cyclohexylene group or a phenylene group, and B ⁵ represents a trans 1,4-cyclohexylene group or a lateral position. H of 1 represents a phenylene group which may be substituted with F, and q and m are each independently 0 or 1 indicating the.), characterized in that a compound represented by Claim 1 or a liquid crystal composition according to 2. 4. The first component is 3 to 40%, the second component is 3 to 40%, and the third component is 5 to 5 with respect to the total weight of the liquid crystal composition.
It is 80%, The liquid crystal composition of Claim 2 or 3 characterized by the above-mentioned. 5. A compound represented by the general formula (III) or (IV) as the fourth component
And (V) (In the formula, R ⁶ and R ⁷ each independently have 1 to 10 carbon atoms.
Or an alkenyl group having 2 to 10 carbon atoms. In any case, any one of the groups or two or more non-adjacent methylene groups (—CH ₂ —) may be replaced by an oxygen atom. C represents a trans 1,4-cyclohexylene group, 2,4-pyrimidinylene group or phenylene group, D represents a trans 1,4-cyclohexylene group or phenylene group, Z ⁷ represents —C≡C—, —C
_{OO -, - C 2 H 4} -, or an -CH = CH- or a single bond. ) (In the formula, R ⁸ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. In either case, any one of the groups or two or more non-adjacent methylene groups (-CH _2- ) may be substituted by an oxygen atom (—O—), R ⁹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, and E is a trans 1,4-cyclohexylene group or 2,4-pyrimidinylene group, G represents a trans 1,4-cyclohexylene group or a phenylene group in which one H at the side position may be substituted with F, and J represents a trans 1,4-cyclohexylene group or indicates a phenylene group, Z ⁸ is -C ₂ H ₄ -,
Represents --COO-- or a single bond, and Z ⁹ represents --C≡C--,-
COO-, -CH = CH- or a single bond is shown. ) [Chemical 11] (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 case, any one of the groups or two or more non-adjacent methylene groups (-CH _2- ) may be substituted by an oxygen atom (—O—), R ¹¹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkoxymethyl group, and Q ¹ represents H or F). The liquid crystal composition according to claim 1, further comprising at least one compound selected from the group of represented compounds. 6. A compound represented by the general formula (VI) or (VII) as a fourth component: (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and k represents 0 or 1. ) [Chemical 13] (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms, and K
Represents a trans 1,4-cyclohexylene group or a phenylene group, and Q ³ and Q ⁴ are each independently H or F.
And Z ¹⁰ and Z ¹¹ are each independently -COO-,-
C ₂ H ₄ − or a single bond is shown, and h is 0, 1 or 2. X represents F or Cl. 5. The liquid crystal composition according to any one of claims 1 to 4, further comprising at least one compound selected from the group consisting of: 7. The content of the fourth component is 70% or less based on the total weight of the liquid crystal composition.
Or the liquid crystal composition according to item 6. 8. A compound represented by the general formula (VI) or (VII): (In the formula, R ¹² represents an alkyl group having 1 to 10 carbon atoms, and Q
² represents H or F, and k represents 0 or 1. ) [Chemical 15] (In the formula, R ¹³ represents an alkyl group having 1 to 10 carbon atoms, and K
Represents a trans 1,4-cyclohexylene group or a phenylene group, and Q ³ and Q ⁴ are each independently H or F.
And Z ¹⁰ and Z ¹¹ are each independently -COO-,-
C ₂ H ₄ − or a single bond is shown, and h is 0, 1 or 2. X represents F or Cl. 7. The liquid crystal composition according to claim 1, containing at least one compound selected from the group consisting of: 9. The liquid crystal composition according to claim 8, wherein the total content of the fourth component and the fifth component is 70% or less with respect to the total weight of the liquid crystal composition. 10. A liquid crystal display device using the liquid crystal composition according to claim 1.