JPH08113780A - Nematic liquid crystal composition and liquid crystal display unit using the composition - Google Patents

Abstract

PURPOSE: To obtain a nematic liquid crystal composition containing compounds selected from respective two groups at least one of which is substituted by deuterium(D), having a low threshold voltage, a high voltage retention, etc., and useful for an electrooptical displaying material, etc. CONSTITUTION: This nematic liquid crystal composition comprises containing a compound selected from the first group consisting of (A) the compounds of formula I to III (R<1> is independently a 2-5C linear alkenyl; R<2> is a 2-5C linear alkyl; at least one of H in two 1,4-cyclohexylene groups of the respective compounds is replaced by D) and a compound selected from the second group consisting of (B) the compounds of formula IV to VI (R<3> is independently a 2-7C linear alkyl; at least one of H in two 1,4-cyclohexylene groups of the respective compounds is replaced by D), and at least one kind of the selected compounds is the compound substituted by D as mentioned previously.

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 useful as an electro-optical display material and a liquid crystal display device using the nematic liquid crystal composition.

[0002]

2. Description of the Related Art TN-LCD is a typical liquid crystal display device.
(Twisted nematic liquid crystal display element)
Used in clocks, calculators, electronic organizers, pocket computers, word processors, personal computers, etc. On the other hand, the amount of information displayed on one screen is increasing with the increase in processing information of OA devices.
ffer) et al. [SID '85 Digest, p. 120 (1985)] or Kinugawa et al. [SID '86 Digest, p. 122 (1986)]
STN-LCD (Super Twisted Nematic Liquid Crystal Display Device) has been developed and is beginning to be widely used in displays for high information processing such as word processors and personal computers.

Further, because of its excellent display quality, an active matrix type liquid crystal display device has been put on the market as an effective one for application fields of displays such as liquid crystal televisions, projector displays and computers. The active matrix display method uses a TFT for each pixel
A switching element such as (thin film transistor) or MIM (metal insulator metal) is used, and it is important in this method that leakage current is small, that is, high voltage holding ratio. (Hereinafter, these active matrix liquid crystal display elements are generically referred to as TFT-LCD.) Therefore, in order to deal with such display elements, new liquid crystal compounds or liquid crystal compositions are still being proposed. ing.

[0004]

The TN-LCD and STN-LCD have problems such as chemical stability of liquid crystal materials, low voltage drivability and response characteristics of liquid crystal display devices.

For example, in a STN-LCD having a large amount of information such as a word processor and a personal computer which are required to have good driving characteristics with a high time division number, it is necessary to reduce the driving voltage. Liquid crystal material of large size is used. However, such a liquid crystal material makes it difficult to obtain a good response characteristic due to an increase in viscosity, or narrows a display frequency range that can be displayed due to an increase in a capacitance component of each pixel and causes a crosstalk phenomenon. Have problems such as.

Further, in the case of a conventional liquid crystal material which can be driven at a low voltage, the prepared resistance value after the initial or accelerated test is often low, and the flicker of the display and the deterioration of the contrast with the increase of the number of time divisions are caused. STN- that uses a backlight for the purpose of compensating for dark image quality
When used in LCDs, chemical stability such as heat resistance and light resistance is newly required.

In addition to these required characteristics, particularly in the active matrix system, it is important to have a small leakage current and a high voltage holding ratio in order to obtain a uniform and high contrast. In order to obtain such characteristics,
For example, the compound of the following general formula (a) has been used.

[0008]

[Chemical 10]

(In the formula, R ⁹ represents a linear alkyl group,

[0010]

[Chemical 11]

Represents a 1,4-cyclohexylene group containing a deuterium atom (D) with a probability corresponding to the abundance ratio with respect to a naturally existing hydrogen atom having a mass number of 1. The same applies below. ) Further, general formulas (a-1) and (a-2)

[0012]

[Chemical 12]

(In the formula, R ⁹ has the same meaning as described above.) However, even if these compounds are used, they are required to maintain the nematic liquid crystallinity in a wide temperature range, particularly at low temperature, and to be required for the active matrix system. There is a problem in satisfying both the reduction of the threshold voltage and the reduction of the threshold voltage. Therefore, the present situation is that the following compounds are further used in combination as the third means.

[0014]

[Chemical 13]

(Wherein R ⁹ has the same meaning as described above,
Z ¹ represents a fluorine atom, OCF ₃ , OCHF ₂ or CF ₃ , Z ² and Z ⁴ each independently represent a hydrogen atom or a fluorine atom, and Z ³ represents a chlorine atom, OCF ₃ , OCHF ₂ or CF ₃ . Represent. In addition, in order to obtain uniform and high-contrast liquid crystal display characteristics, the product Δn · d of the thickness d of the liquid crystal layer of the liquid crystal panel and the birefringence Δn of the liquid crystal material is 0.35 to 0.55. (Hereinafter, this is referred to as the first minimum) is said to be preferable. Since the thickness d currently used in the manufacturing process of liquid crystal panels is about 4.5 μm or more, it is required to set the birefringence Δn of the liquid crystal material to 0.07 to 0.10. However, the characteristics of smaller birefringence and lower threshold voltage tend to conflict with each other, making it difficult to satisfy both. In addition, the phase of such a liquid crystal material at a low temperature tends to be a smectic phase or a glass state, and maintaining a nematic liquid crystal property becomes a new problem.

The problem to be solved by the present invention is to meet the above-mentioned problems, and in particular, a liquid crystal composition which exhibits liquid crystallinity in a wide temperature range, has a low threshold voltage and has a sufficiently high voltage holding ratio. And using this liquid crystal composition,
An object of the present invention is to provide a liquid crystal display device which does not generate flicker and has excellent contrast.

[0017]

In order to solve the above-mentioned problems, the present invention provides the following nematic liquid crystal compositions.

First, as the first liquid crystal composition of the present invention,
(1) General formulas (I) to (III)

[0019]

Embedded image

(In the formula, each R ¹ independently represents a linear alkenyl group having 2 to 5 carbon atoms, and R ² represents a linear alkyl group having 2 to 5 carbon atoms. At least one of the two 1,4-cyclohexylene groups
Each hydrogen atom (H) may be replaced with a deuterium atom (D). And a compound selected from the first group consisting of the compounds represented by the formula (2) and the general formulas (IV) to (VI)

[0021]

[Chemical 15]

(In the formula, R ^3's each independently represent a linear alkyl group having 2 to 7 carbon atoms, and at least one hydrogen atom (H) in the two 1,4-cyclohexylene groups in each compound. ) Contains a compound selected from the second group consisting of compounds represented by the deuterium atom (D), and at least one of the compounds selected from the two groups is There is provided a nematic liquid crystal composition, which is a compound in which at least one hydrogen atom (H) of two 1,4-cyclohexylene groups is substituted with a deuterium atom (D).

In the compounds represented by the above general formulas (I) to (VI), at least one hydrogen atom (H) of the two 1,4-cyclohexylene groups in the compound is replaced with a deuterium atom (D). As the compound obtained, for example, the following compounds can be used.

[0024]

Embedded image

(In the formula, R ¹ independently represents a linear alkenyl group having 2 to 5 carbon atoms, R ² represents a linear alkyl group having 2 to 5 carbon atoms, and R ³ represents Each independently represents a linear alkyl group having 2 to 7 carbon atoms, X ^{1 to} X ⁴ each independently represent a hydrogen atom (H) or a deuterium atom (D), and X ^{5 to} X ⁷ represent Each independently represents a hydrogen atom (H) or a deuterium atom (D), but at least one of X ^{1 to} X ⁴ or X ^{5 to} X ⁷ in each compound represents a deuterium atom.) Among the above compounds, the liquid crystal composition of the present invention preferably contains a compound selected from the group consisting of compounds represented by formulas (I-1) to (V-1).

Among these first liquid crystal compositions, the general formula (III-1), the general formula (III-2) and the general formula (IV-
1)

[0027]

[Chemical 17]

(In the formula, R ² represents a linear alkyl group having 2 to 5 carbon atoms, and X ^{1 to} X ⁴ each independently represent a hydrogen atom (H) or a deuterium atom (D). , At least one represents a deuterium atom (D), X ^{5 to} X ⁷ each independently represents a hydrogen atom (H) or a deuterium atom (D), but at least one is a deuterium atom (D). Represents.)
A nematic liquid crystal composition containing a compound represented by as an essential component.

The feature of this composition is that the compounds represented by the general formula (III-1), the general formula (III-2) and the general formula (IV-1) are used in combination as an essential component. The liquid crystal composition thus obtained has a property of inducing and expanding a nematic phase at a low temperature without deteriorating the excellent characteristics of each compound, and the nematic liquid crystal can be stored even at a low temperature. It has been found that a nematic liquid crystal composition can be prepared which can retain its properties for a longer period and can be used in a wide temperature range.

To describe this in detail, the following liquid crystal composition (1-1) and comparative liquid crystal composition (1-2)
Was prepared.

[0031]

Embedded image

The liquid crystal composition (1-1) consisting of the nematic liquid crystal composition of the present invention has a nematic phase of 95.
It was 6--40 degreeC. Outside the invention

[0033]

[Chemical 19]

The liquid crystal composition (1-2) consisting of
The hydrogen atom (H) of the two 1,4-cyclohexylene groups in the compounds of formula (III-1), general formula (III-2) and general formula (IV-1) is substituted with a deuterium atom (D). The nematic phase is 96.2--1.
It was 1 ° C.

From the above, the liquid crystal composition (1-
1) has a nematic phase at a wider temperature than that of the liquid crystal composition (1-2), and it is clear that the expansion of the nematic phase is large especially on the low temperature side.

The characteristics of this liquid crystal composition are characterized by the general formula (III-
1), the compound represented by the general formula (III-2) and the general formula (IV-1), one or more hydrogen atoms (H) of two 1,4-cyclohexylene groups in each compound are heavy. It is at the point of being replaced by a hydrogen atom (D). Such a liquid crystal composition,
It has the property of stabilizing the nematic phase at low temperatures, and can retain the nematic liquid crystallinity for a longer period of time even when stored at low temperatures. The present inventors have demonstrated the effects of a compound having a 1,4-cyclohexylene group substituted on the deuterium atom (D) in Japanese Patent Application Nos. 5-104144 and 5-1.
As disclosed in the specification of No. 82734 and the like, the present invention further enhances this effect.

Further, the compounds represented by the general formula (III-1), the general formula (III-2) and the general formula (IV-1) having the above deuterium atom (D) include the deuterium atom (D) Compared with a compound having a 1,4-cyclohexylene group that is not substituted with, the elastic constants and ratios thereof have significant values, and the electro-optical characteristics can be adjusted according to the application.

In this composition, if the compounds of the general formulas (III-1) and (III-2) are too much, crystallization or precipitation tends to occur, and if too small, the effect of the present invention is difficult to obtain. Therefore, it is preferable to use each in the range of 5 to 40% by weight. When the amount of the compound of the general formula (IV-1) is too large, the smectic phase is increased or precipitated easily, and when it is too small, the effect of the present invention is obtained. Since it becomes difficult, it is preferable to use in the range of 5 to 40% by weight.

This composition has the general formula (III-1) and the general formula (II
In addition to the compound of I-2) and the general formula (IV-1), in order to improve other properties of the liquid crystal composition, a normal nematic liquid crystal recognized as a liquid crystal compound, a smectic liquid crystal, a cholesteric liquid crystal, etc. are contained. You may have.

The liquid crystal composition of the present invention thus obtained has a crystalline phase at a nematic phase-isotropic liquid phase transition temperature (T _NI ) of 90 ° C. or higher, as shown in Examples described later. Alternatively, the smectic phase-nematic phase transition temperature (T → _N ) has a nematic phase at a wide temperature of −30 ° C. or less,
The characteristics of the birefringence Δn of about 75 and the threshold voltage V _th of about 1.5 V could be obtained.

Further, this composition was subjected to a heating acceleration test and an ultraviolet irradiation acceleration test shown in Examples described later, and as a result, it had a high voltage holding ratio of 98% or more after each acceleration test and was chemically It was confirmed that it was very stable and had a high resistance value.

As described above, the nematic liquid crystal composition of the present invention is a liquid crystal composition which exhibits liquid crystallinity in a wide temperature range and has a sufficiently high voltage holding ratio, which does not cause flicker and is excellent in contrast. It has become possible to provide a liquid crystal display device. Further, when an active matrix liquid crystal display device was manufactured, flicker did not occur, and a liquid crystal display device excellent in contrast could be manufactured. Furthermore, when TN-LCD and STN-LCD liquid crystal display panels were manufactured, it was confirmed that display was possible with a wide range of drive frequencies.

The present invention provides a second liquid crystal composition, which comprises a compound of the general formula (VII) as a component to be added to the first liquid crystal composition,
(VIII)

[0044]

Embedded image

(In the formula, R ^4's each independently represent a linear alkyl group having 2 to 5 carbon atoms, Y ^1's each independently represent a hydrogen atom or a fluorine atom, and two 1's in each compound are represented. , 4-cyclohexylene group containing at least one hydrogen atom (H) which may be substituted with a deuterium atom (D)). A characteristic nematic liquid crystal composition is provided.

Of the compounds of this third group, two 1,4
-As a compound in which at least one hydrogen atom (H) of a cyclohexylene group is replaced by a deuterium atom (D),
General formula (VIII-1)

[0047]

[Chemical 21]

(In the formula, R ⁴ represents a linear alkyl group having 2 to 5 carbon atoms, Y ¹ represents a hydrogen atom or a fluorine atom, and X ^{1 to} X ⁴ are each independently a hydrogen atom (H ) Or a deuterium atom (D), at least one of which represents a deuterium atom (D).

As the third liquid crystal composition of the present invention,
General formulas (IX) and (X) as components added to the first liquid crystal composition or the second liquid crystal composition

[0050]

[Chemical formula 22]

(In the formula, R ⁵ independently represents an alkyl group having 3 to 7 carbon atoms, Y ¹ and Y ² each independently represents a hydrogen atom or a fluorine atom, and 1, 4 in each compound -At least one hydrogen atom (H) in the cyclohexylene group may be substituted with a deuterium atom (D)), and a compound selected from the fourth group consisting of compounds represented by the formula: A nematic liquid crystal composition is provided.

As the fourth liquid crystal composition of the present invention,
The first liquid crystal composition, the second liquid crystal composition or the third liquid crystal composition
As a component added to the liquid crystal composition of the general formula (XI) ~ (XV)

[0053]

[Chemical formula 23]

(In the formula, each R ⁶ independently represents a linear alkyl group or an alkenyl group having 2 to 5 carbon atoms, and each R ⁷ independently represents a linear alkyl group having 1 to 5 carbon atoms. Group, an alkoxy group or a linear alkenyl group having 2 to 5 carbon atoms, R ⁸ represents a linear alkyl group having 2 to 5 carbon atoms, and r each independently represents 0 or 1. Y ¹ and Y ² each independently represent a hydrogen atom or a fluorine atom, and at least 1 in each compound.
At least one hydrogen atom (H) of each 1,4-cyclohexylene group may be substituted with a deuterium atom (D). And a nematic liquid crystal composition containing a compound selected from the fifth group consisting of the compounds represented by

The present invention further provides an active matrix liquid crystal display device, a twisted nematic liquid crystal display device, or a super twisted nematic liquid crystal display device using the nematic liquid crystal composition according to any one of the first to fourth embodiments.

In describing the present invention in detail, all the 1,4-cyclohexylene groups of each compound among the compounds of the general formulas (I) to (X), (XIV) and (XV) are as described above. Examples of the compound which is the 1,4-cyclohexylene group defined by the formula (b) are represented by the following general formulas (I-0) to (X-0),
Represented as (XIV-0) and (XV-0).

[0057]

[Chemical formula 24]

(Where R⁰¹~ R⁰⁶, R⁰⁸, Y⁰¹, Y
⁰²Are each independently the aforementioned R¹~ R⁶, R ⁸, Y¹, Y²
Is the same meaning as. ) Compounds represented by the general formulas (I) to (XI) according to the present invention
No. (1-1) to (1
-9) and the phase transition temperatures thereof are shown in Tables 1 and 2 below.
Shown in the table. In Tables 1 and 2 below, is mp a crystalline phase?
Represents the temperature at which the liquid crystal phase or isotropic liquid phase transitions,
cp is the temperature at which the liquid crystal phase changes to the isotropic liquid phase.
Represent each. In addition, each liquid crystal compound is distilled and
Purify thoroughly by removing impurities using manufacturing, recrystallization, etc.
I used what I did.

[0059]

[Table 1]

[0060]

[Table 2]

The characteristics of the liquid crystal composition of the present invention are selected from the first compound group represented by the general formulas (I) to (III) and the second compound group represented by the general formulas (IV) to (VI). The compound is used in combination as an essential component. The liquid crystal composition thus obtained has a property of inducing and expanding a nematic phase particularly at low temperature, and can retain the nematic liquid crystallinity for a longer period even when stored at low temperature.

The compound represented by the general formula (I) in the first compound group includes a linear alkenyl group and 3,4,5-
It has a trifluorophenyl group. When this compound is combined with other compounds according to the present invention, there is a problem that crystal precipitation is observed during long-term low temperature storage, but it exhibits compatibility that induces and expands a nematic phase on the low temperature side, and has a voltage holding ratio. This has the effect of maintaining or reducing the drive voltage without lowering it. In particular, as for compatibility, the general formula (a) having a similar structure to the general formula (I) is apparent from the examples described later.

[0063]

[Chemical 25]

From the result of comparison with the compound of (1), it was clarified that a particular effect was exhibited by a slight difference in whether the side chain group was an alkenyl group or an alkyl group. General formula (II), (II
The compound represented by I) has a 3,4-difluorophenyl group and is characterized by the above-mentioned compatibility. In addition, since the compound of the general formula (II) has a larger birefringence Δn than the compounds of the general formulas (I), (III) to (VI), a nematic liquid crystal composition having a birefringence according to the application is adjusted. However, the compound represented by the general formula (III) has a relatively low threshold voltage and is useful for this adjustment.

The compounds represented by the general formulas (I) and (II) have an elastic constant ratio (K ₃₃ /
K ₁₁ ) is larger or smaller than the general formulas (III) to (VI). Therefore, it is possible to prepare a nematic liquid crystal composition having an elastic constant ratio according to the application.
Furthermore, the compounds of the general formulas (I) and (II) can also reduce the viscosity of the nematic liquid crystal composition, and therefore, by combining with the compounds of the general formulas (III) to (XI), a fast response in a wide temperature range A liquid crystal material having a property can be easily obtained. The compounds represented by the general formulas (I) and (II) are particularly excellent.

[0066]

[Chemical formula 26]

General formulas (IV) to (V in the second compound group
Compounds represented by I) _{are, -C 2 H 4 -, -} C 4 H 8 - have a linking group, 3,4-difluorophenyl group, 3,
It has a 4,5-trifluorophenyl group. These compounds have a birefringence Δn of the general formula (I) to
Since it is smaller than the compound of (III), it is possible to adjust a nematic liquid crystal composition having a birefringence index according to the application, and it has the effect of maintaining or reducing the driving voltage without lowering the voltage holding ratio. I found out that

However, the compounds represented by the general formulas (IV) to (VI) tend to exhibit a smectic phase. For example, in a composition containing only these compounds, the nematic phase is very narrow due to the presence of the smectic phase. In particular, it was difficult to prepare a nematic liquid crystal composition that can be driven at room temperature to low temperature.

The present inventors have found that the above general formulas (I) to (V
As a result of examining various combinations of the compounds represented by I), the compounds selected from the compounds represented by the general formulas (I) to (III) and the compounds represented by the general formulas (IV) to (VI) were selected. By using the compound
It was found that a nematic liquid crystal composition that can be used in a wide temperature range can be prepared without impairing the excellent properties of each compound.

To explain this in detail, the following liquid crystal composition (2-1) and comparative liquid crystal composition (2-2) to
(2-4) was produced.

[0071]

[Chemical 27]

The liquid crystal composition (2-1) consisting of is the nematic liquid crystal composition of the present invention and has a nematic phase of 10 or less.
It was 5.4 to -12 ° C. Outside the invention

[0073]

[Chemical 28]

The liquid crystal composition (2-2) consisting of the compounds of the general formulas (I-0) to (III-0) has a nematic phase of 107.1 to + 20 ° C. . Outside the invention

[0075]

[Chemical 29]

The liquid crystal composition (2-3) consisting of the compounds of the general formulas (IV-0) to (VI-0) has a nematic phase of 85.4 to + 40 ° C. . From the above, the liquid crystal composition (2-1) of the present invention has a nematic phase at a wider temperature than the liquid crystal compositions (2-2) and (2-3), and particularly on the low temperature side. It is clear that the expansion of the nematic phase is large. This is an effect obtained by combining the first compound group and the second compound group, and shows that it is possible to prepare a nematic liquid crystal composition that can be driven at a wide temperature.

In addition, outside the scope of the present invention

[0078]

Embedded image

A liquid crystal composition (2-4) consisting of the compound of the general formula (I) according to the present invention in the liquid crystal composition (2-2) is a compound having a similar structure in which R ¹ is an alkyl group. It was prepared by substituting the compound of formula (a), and the nematic phase thereof was 97.4 to + 31 ° C. As is clear from the comparison between the above-mentioned liquid crystal compositions (2-2) and (2-4), the temperature range of the nematic phase is further narrowed at both the high temperature and the low temperature. This has an unexpected effect of greatly changing despite a slight difference between the alkenyl group of the side chain group R ¹ of the general formula (I) and the alkyl group of the side chain group R ⁹ of the general formula (a). It is shown.

As will be described in more detail below, in the present invention, the idea of the following reference that the difference in the side chain group and the skeletal structure of the liquid crystal compound is slight is thoroughly studied, and a liquid crystal of a new combination is evaluated by this criticism. They came to find a composition.

The present inventors tried to investigate various mixtures using the compound of the general formula (a) in which the side chain group R ¹ of the general formula (I) was replaced with an alkyl group, but it was stable at low temperature. It is difficult to maintain the nematic phase, and when used in combination with the compounds (I) to (VI) according to the present invention, 10% by weight or less, more preferably 8% by weight or less,
It has been found that the lack of compatibility is ameliorated by the most preferable amount being around 5% by weight. Therefore, this similar compound can be used as a third means, for example, by the following general formula (2
It was essential to use in combination with the compounds of -5) to (2-7).

[0082]

[Chemical 31]

(Wherein R ⁹ has the same meaning as described above, and Z ¹
Represents a fluorine atom, OCF ₃ , OCHF ₂ , CF ₃ ;
Z ² and Z ⁴ represent a hydrogen atom or a fluorine atom, and Z ³ represents a chlorine atom, OCF ₃ , OCHF ₂ or CF ₃ . However, even if such a means is used, there is still a problem.
For example, Japanese Patent Publication No. 5-500681 and Japanese Patent Publication 5-5
According to the technique disclosed in Japanese Patent No. 00682, the mixing ratio of the compound of the general formula (2-5) and the compound of the general formulas (III-0) to (V-0) is 1: 4 to 1: 1. Is preferred, and it is more preferred that the compound of the general formula (2-5) is contained in an amount of 40% by weight or more. For this reason, the nematic phase-isotropic liquid phase transition temperature T _NI is as low as 80 ° C. or less, or the threshold voltage V _th when the TN-LCD is constructed.
Is not as high as 1.5 V or higher, and the characteristics currently required have not been obtained. Furthermore, since the compound of the general formula (2-5) is frequently used, the vapor pressure temperature characteristic is deteriorated, and the liquid crystal injection condition in the manufacturing process of the liquid crystal display panel becomes strict.
Alternatively, there is a new problem such as uneven injection. Further, for example, according to the technique disclosed in Japanese Patent Publication No. 5-500830, the mixing ratio of the compound of the general formula (2-7) and the compound of the general formulas (III-0) to (V-0) is 1: 4
~ 1: 1 is considered good, and the compound of general formula (2-7) is 4
It is peculiar that it is more preferable to contain 0% by weight or more. This technique also uses a large amount of the compound of the general formula (2-5) in order to improve the nematic phase at a low temperature, and does not satisfy the required characteristics for T _NI or V _th as described above. Of. Further, in the case where the birefringence Δn is as large as 0.13 or more, the cell thickness d suitable for the first minimum (Δn · d = 0.5).
Is about 4 μm or less, and there are new problems such as strict conditions for uniform cell production in the process of producing a liquid crystal display panel or occurrence of display unevenness.

The present invention does not have the problems caused by relying on the third means as described above in order to obtain a nematic phase at a low temperature, and the general formulas (I) to (III)
And a compound represented by any one of the general formulas (IV) to (VI) in combination, the composition has little or no loss in the characteristics of the individual compounds.

Further advantages of the present invention will be described in detail below. For example, a liquid crystal composition (2
-8)

[0086]

Embedded image

In, the nematic phase is 70.7 to 44 ° C. Alternatively, a liquid crystal composition (2-9) obtained by mixing with a compound of the general formula (III)

[0088]

[Chemical 33]

In the case of the nematic phase, the temperature is 85 to 33 ° C., which is not improved even if the number of components is increased. However, the compounds of general formula (I) and general formula (V), which are the essential components of the present invention, were combined.

[0090]

Embedded image

In the liquid crystal composition (2-10) consisting of the nematic phase of 79.6 to + 10 ° C.,
And a compound of general formula (V)

[0092]

Embedded image

In the liquid crystal composition (2-11) made of, the nematic phase is 89.1 to + 1 ° C., and the nematic phase at a low temperature can be greatly expanded. The following can be further mentioned as such an example. A combination of compounds of general formulas (II) and (III) and general formula (V)

[0094]

Embedded image

In the liquid crystal composition (2-12) made of, the nematic phase is 83 to 15 ° C. General formula (I), (II)
And a compound of general formula (VI)

[0096]

Embedded image

In the liquid crystal composition (2-13) made of, the nematic phase is 90 to -30 ° C. Combined compounds of general formula (II) and general formula (VI)

[0098]

[Chemical 38]

In the liquid crystal composition (2-14) made of, the nematic phase is 96 to -20 ° C. Combined compounds of general formula (I) and general formulas (V) and (VI)

[0100]

[Chemical Formula 39]

In the liquid crystal composition (2-15) made of, the nematic phase is 79.0 to -7 ° C. As described above, a nematic liquid crystal composition that can be driven at low temperature with a very narrow nematic phase only by the compounds of the general formulas (I) to (III) or only the compounds of the general formulas (IV) to (VI). Was difficult to prepare, but at least one compound selected from the first group consisting of the compounds represented by the general formulas (I) to (III) and the general formulas (IV) to (VI) The liquid crystal composition of the present invention, which contains at least one compound selected from the second group consisting of the following compounds as an essential component, is an excellent nematic liquid crystal composition that can be used in a wider temperature range. Is confirmed.

The superiority of the present invention as described above will be made clearer in comparison with the prior art disclosed in, for example, Japanese Patent Publication No. 5-501735. According to this prior art, a compound having a 3,4,5-trifluorophenyl group represented by the general formula (a) and, for example, the general formulas (III-0) and (IV-0)
It is said that a good mixing ratio with the compound having a 3,4-difluorophenyl group represented by is 1: 4 to 1: 1 and the compound has a 3,4,5-trifluorophenyl group represented by the general formula (a). It is said that it is preferable that the content of the compound is 50% by weight or less. This has not yet been sufficiently reduced although the lower threshold voltage is a problem, and the cause is that the compatibility at low temperature or the narrowness of the nematic phase is a problem, and a large amount is contained. It seems that this is because it cannot be done.

The compounds having the 3,4,5-trifluorophenyl group in the present invention are represented by the general formulas (I) and (IV)
The compound represented by (VI) can be mixed with the compound of the general formulas (II), (III) and (IV) having a 3,4-difluorophenyl group in a mixing ratio of 1: 1 or more, or in the total content. Even if it is contained in an amount of 50% by weight or more, a nematic liquid crystal composition that can be used in a wide temperature range can be prepared without requiring any special third means.

The second characteristic of the liquid crystal composition of the present invention is that one or more compounds selected from the first group and the second group represented by the general formulas (I) to (VI). Is one of the two 1,4-cyclohexylene groups in each compound.
The point is to contain a compound in which one or more hydrogen atoms (H) are replaced by deuterium atoms (D). Such a liquid crystal composition has a property of stabilizing a nematic phase at a low temperature, and in particular, can retain the nematic liquid crystallinity for a longer period even when stored at a low temperature. The present inventors have confirmed the effects of a compound having a cyclohexane ring substituted with a deuterium atom, in Japanese Patent Application Nos. 5-104144 and 5-182734.
As described in the specification, etc., the present invention further enhances this effect. That is, according to the second feature of the present invention, for example, the liquid crystal composition of the present invention has a nematic property for a long time even when stored at -25 ° C or -40 ° C, which will be described in detail in Examples below. Is something that can be done.

A third feature is that the compounds represented by the general formulas (I) to (VI) having a deuterium atom described above have the general formula (I-) having a cyclohexane ring not substituted by a deuterium atom. 0) to (VI-0), they show significant elastic constants and ratios thereof, or an advantageous threshold voltage as compared with the compounds represented by the formulas (0) to (VI-0), and can be adjusted to have electro-optical characteristics according to the application. It is a thing.

The compounds represented by the general formulas (VII) to (XV) used in the nematic liquid crystal composition of the present invention maintain and improve the above-mentioned properties and the properties required for TN-LCD, STN-LCD, TFT-LCD and the like. Have the effect of

Specifically, the compounds represented by the general formulas (VII) and (X) have a liquid crystal composition having a birefringence (Δn) of 0.0.
It is possible to improve the viewing angle characteristic of the liquid crystal display device, increase the contrast ratio, etc. by optimizing it to 8 to 0.10. Further, it has an effect of expanding the nematic phase temperature range of the composition to the high temperature side and the low temperature side, and can expand the drivable temperature range of the liquid crystal display device.

In the compounds represented by the general formulas (IX) and (X), each compound having a-(CH ₂ ) ₂ --or-(CH ₂ ) ₄ --linking group is represented by the general formulas (I) to (VI). It also has excellent compatibility with the above compounds. In addition, these compounds are
Compared with the compound represented by the general formula (2-5), it is also excellent in vapor pressure temperature characteristics, and relaxes the liquid crystal injection conditions in the manufacturing process of a liquid crystal display panel, even if it is frequently used in the liquid crystal composition of the present invention. It is also possible to reduce injection unevenness in the manufacturing process of a large-sized liquid crystal panel. The compound of the general formula (X) is useful for reducing the threshold voltage,
It is possible to provide a liquid crystal composition suitable for portable applications that require a low driving voltage.

The compounds of the general formulas (XI) and (XII) can be used by adding them to a liquid crystal composition containing the compounds of the general formulas (I) to (VI) to reduce the birefringence (Δn). Alternatively, it is useful for reducing viscosity.

The nematic liquid crystal composition of the present invention may contain a compound selected from the group consisting of compounds represented by formulas (XIII) to (XV). The compounds represented by the general formulas (XIII) to (XV) can extend the temperature range of the nematic phase of the liquid crystal composition to a high temperature region and / or a low temperature region. Since the compound of the general formula (XIII) can reduce the viscosity of the nematic liquid crystal composition, it is possible to obtain a liquid crystal material having a fast response in a wide temperature range. The compounds represented by the general formulas (XIV) and (XV) have a birefringence (Δn) of the liquid crystal composition of 0.07 to
By optimizing to 0.09, it is possible to improve the viewing angle characteristics of the liquid crystal display device and increase the contrast ratio. The general formula (XV) is useful for reducing the threshold voltage and the saturation voltage, and can provide a liquid crystal composition suitable for portable applications requiring a low driving voltage and labor saving of a driving circuit.

In addition to the compounds of the general formulas (I) to (XV), the liquid crystal composition of the present invention is a conventional nematic compound recognized as a liquid crystal compound in order to improve other characteristics of the liquid crystal composition. Liquid crystals, smectic liquid crystals, cholesteric liquid crystals and the like may be contained.

The content of each compound in the liquid crystal composition of the present invention is 0 to 25% by weight of the compound represented by the general formula (I), 0 to 25% by weight of the compound represented by the general formula (II), and It is preferable to contain the compound represented by the formula (III) in the range of 0 to 20% by weight. The compound represented by the general formula (IV) is 0 to 20% by weight, the compound represented by the general formula (V) is 0 to 30% by weight, and the compound represented by the general formula (VI) is 0 to 30% by weight. It is preferable to contain.

The total content of each compound in the liquid crystal composition is 0 to 50% by weight for the compound group of general formula (I), 0 to 50% by weight for the compound group of general formula (II), and II
The compound group I) is preferably contained in the range of 0 to 40% by weight, the compound group of the general formula (IV) is 0 to 35% by weight, the compound group of the general formula (V) is 0 to 40% by weight, It is preferable to contain the compound group of the general formula (VI) in the range of 0 to 40% by weight.

Further, the total content of each compound group is preferably such that the first group of the general formulas (I) to (III) is contained in the range of 10 to 80% by weight, and the general formulas (IV) to (VI) are contained. It is preferable to contain the second group of 5 to 50% by weight.

The compounds represented by the general formulas (VII) to (X) are preferably contained in the range of 0 to 25% by weight, and the compounds represented by the general formulas (XI) to (XIII) are each contained in the range of 0 to 20%. The content of the compound represented by the general formula (XIV) is preferably 0 to 30% by weight, and the content of the compound represented by the general formula (XV) is 0 to 10%. It is preferably contained in the range of wt%.

The compounds according to the present invention can be combined as follows according to the purpose required for the liquid crystal composition or liquid crystal display characteristics. For the purpose of lowering the crystal phase or the smectic phase-nematic phase transition temperature T → _N of the liquid crystal composition, a combination of (I) + (II) + (V) + (VI) is preferable, and further (VII) to (VII) It is preferred to combine VIII) or particularly preferred to combine (XIV). For the purpose of increasing the nematic phase-isotropic liquid phase transition temperature T _NI of the liquid crystal composition and lowering the crystal phase or smectic phase-nematic phase transition temperature T → _N ,
A combination of (I) + (II) + (V) + (VI) is preferable, and further combinations of (VII) to (X) or (XIII) are preferable. For the purpose of lowering the threshold voltage V _th of liquid crystal display, a combination of (I) + (V) + (VI) is preferable, and (VII) to (X), (XIV), (XV) are further combined. It is preferable. For the purpose of accelerating the response characteristics of liquid crystal display, a combination of (I) + (II) + (VI) is preferable, and further combinations of (V) and (X) to (XIII) are preferable. The birefringence Δn of the liquid crystal composition is 0.07 to 0.
For the purpose of setting 08, (I) + (III) + (IV) to (VI)
Is preferable, and (I) + (II) + for the purpose of setting the birefringence Δn of the liquid crystal composition to 0.08 to 0.10.
A combination of (IV) is preferable, and further (VII) and (VII
It is preferable to combine I) and (XIV).

The liquid crystal composition of the present invention thus obtained has a nematic phase-isotropic liquid phase transition temperature (T _NI ) of 85 to 100 ° C., as shown in Examples below. 1.3 to 1.6 threshold voltage (V _th ), 100 to 13
Nematic phase-isotropic liquid phase transition temperature (T _NI ) at 0 ° C
Of which the threshold voltage (V _th ) is 1.6 to 2.0, the crystal phase or smectic phase-nematic phase transition temperature (T → _N ) at -40 ° C or lower, 0.07 to 0. The characteristics of birefringence Δn of 10 and dielectric anisotropy (Δε) of 6 to 9 could be obtained.

The nematic liquid crystal composition of the present invention is
When the heating acceleration test and the ultraviolet irradiation acceleration test shown in the examples described later were carried out, it had a high voltage holding ratio of 98% or more even after each acceleration test and had a chemically very stable and high resistance value. It was confirmed.

As described above, the nematic liquid crystal composition of the present invention is a liquid crystal composition which exhibits liquid crystallinity in a wide temperature range, has a low threshold voltage, and has a sufficiently high voltage holding ratio, and flicker occurs. Instead, it is possible to provide a liquid crystal display device having excellent contrast. Further, when an active matrix liquid crystal display device was produced, a liquid crystal display device having excellent contrast without producing flicker could be produced. Furthermore, when TN-LCD and STN-LCD liquid crystal display panels were manufactured, it was confirmed that display was possible in a wide range of drive frequencies.

[0120]

The present invention will be described in detail below with reference to examples.
The present invention is not limited to these examples. In the examples, the meanings of the symbols of the measured characteristics are as follows.

T _NI : Nematic phase-isotropic liquid phase transition temperature (° C.) T → _N : Crystal phase or smectic phase-nematic phase transition temperature (° C.) V _th : First minimum Δ when the thickness of the panel liquid crystal layer is d Threshold voltage (V) when configuring a TN-LCD with n · d = 0.5 Δε: Dielectric anisotropy Δn: Birefringence τr = τd: Apply voltage from no voltage applied Response time (msec) at which rise time τr until light becomes transparent and fall time τd at which voltage is removed from the voltage applied state until light no longer penetrates are equal to Pr _-25 : Stored at -25 ° C. The time when the liquid crystal composition has nematic properties (days) Pr _-40 : The time when the liquid crystal composition has nematic properties by storing at -40 ° C (days) Further, the accelerated test of the composition is as follows. After degassing, treat with nitrogen and seal. Turn on,
The test was conducted at 180 ° C. for 1 hour for heating promotion test and for 10 hours for ultraviolet irradiation promotion test “SUNTEST” (manufactured by Original Hanau). The specific resistance and voltage holding ratio of the liquid crystal composition were measured before and after the accelerated test. (Example 1)

[0122]

[Chemical 40]

A nematic liquid crystal composition (3-1) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 103.9 ° C. T → _N : −47 ° C. V _th : 1.80 V Δε: 6.4 Δn: 0.095 Pr _-25 : 30 days Pr _-40 : 30 days Specific resistance before test : 6.9 × 10 ¹³ Ω cm Specific resistance after heating accelerated test: 5.5 × 10 ¹³ Ω cm Specific resistance after ultraviolet irradiation accelerated test: 2.9 × 10 ¹³ Ω cm Voltage holding ratio before test: 99.4 % (Measurement temperature 80 ° C.) Voltage holding ratio after heating acceleration test: 98.5% (measurement temperature 80 ° C.) Voltage holding ratio after ultraviolet irradiation acceleration test: 98.1% (measurement temperature 80 ° C.) This nematic liquid crystal composition ( When an active matrix liquid crystal display device using 3-1) as a constituent material was produced, it was confirmed that the device had an excellent leakage current and no flicker.

The nematic liquid crystal composition (3-1)
A liquid crystal composition was prepared by adding a chiral substance "S-811" (manufactured by Merck & Co., Inc.) to. On the other hand, an organic film of "SAN EVER 150" (manufactured by Nissan Kagaku Co., Ltd.) is rubbed on the opposing flat transparent electrodes to form an alignment film, and STN-LCD with a twist angle of 220 degrees is formed.
A display cell was produced. The liquid crystal composition was injected into this cell to form a liquid crystal display device, and the display characteristics were measured.
As a result, the threshold voltage is low, high time division characteristics are excellent,
ST with improved display screen flickering and crosstalk
A liquid crystal display device having N-LCD display characteristics was obtained. (Example 2)

[0125]

Embedded image

A nematic liquid crystal composition (3-2) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 128.4 ° C. T → _N : <−70 ° C. V _th : 1.93 V Δε: 7.4 Δn: 0.108 Pr _-25 : 30 days Pr _-40 : 30 days

A liquid crystal composition was prepared by adding a chiral substance "S-811" (manufactured by Merck Ltd.) to the nematic liquid crystal composition (3-2). On the other hand, an organic film of "SAN EVER 150" (manufactured by Nissan Kagaku Co., Ltd.) was rubbed on the opposing flat transparent electrodes to form an alignment film, and a STN-LCD display cell with a twist angle of 220 degrees was produced. The liquid crystal composition was injected into this cell to form a liquid crystal display device, and the display characteristics were measured. As a result, STN-LC has a low threshold voltage, excellent high time division characteristics, and improved display screen flicker and crosstalk phenomenon.
A liquid crystal display device having D display characteristics was obtained.

(Example 3)

[0129]

Embedded image

A nematic liquid crystal composition (3-3) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 113.1 ° C. T → _N : −65 ° C. V _th : 1.65 V Δε: 7.3 Δn: 0.088 Pr _-25 : 30 days Pr _-40 : 30 days

(Comparative Example 1)

[0132]

[Chemical 43]

A liquid crystal composition (3-a) consisting of
Various properties of this composition were measured. The results were as follows. T _NI : 113.6 ° C. T → _N : −30 ° C. V _th : 1.7 V Δε: 7.2 Δn: 0.089 Pr _-25 : 10 days Pr _-40 : 7 days This liquid crystal composition ( As is clear from comparison of 3-a) with various characteristics of the nematic liquid crystal composition (3-3) of the present invention, the nematic liquid crystal composition (3-3) further expands the nematic layer on the low temperature side. It is an excellent material that retains a nematic phase for a longer period of time at low temperature storage.

(Example 4)

[0135]

[Chemical 44]

A nematic liquid crystal composition consisting of (3-4)
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 96.4 ° C. T → _N : −41 ° C. V _th : 1.60 V Δε: 6.9 Δn: 0.083 Pr _-25 : 30 days Pr _-40 : 30 days

(Example 5)

[0138]

Embedded image

A nematic liquid crystal composition consisting of (3-5)
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 89.3 ° C. T → _N : <−70 ° C. V _th : 1.43 V Δε: 8.0 Δn: 0.088 Pr _-25 : 30 days Pr _-40 : 30 days

(Example 6)

[0141]

Embedded image

A nematic liquid crystal composition (3-6) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 100.2 ° C. T → _N : <−70 ° C. V _th : 2.03 V Δε: 5.5 Δn: 0.089 Pr _-25 : 30 days Pr _-40 : 30 days

A liquid crystal composition was prepared by adding a chiral substance "S-811" (manufactured by Merck & Co.) to the nematic liquid crystal composition (3-6). On the other hand, an organic film of "SAN EVER 150" (manufactured by Nissan Kagaku Co., Ltd.) was rubbed on the opposing flat transparent electrodes to form an alignment film, and a STN-LCD display cell with a twist angle of 220 degrees was produced. The liquid crystal composition was injected into this cell to form a liquid crystal display device, and the display characteristics were measured. As a result, STN-LC has a low threshold voltage, excellent high time division characteristics, and improved display screen flicker and crosstalk phenomenon.
A liquid crystal display device having D display characteristics was obtained.

(Embodiment 7)

[0145]

[Chemical 47]

A nematic liquid crystal composition consisting of (3-7)
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 91.3 ° C. T → _N : <−70 ° C. V _th : 1.40 V Δε: 8.9 Δn: 0.119 Pr _-25 : 30 days Pr _-40 : 30 days Ratio before test Resistance: 7.1 × 10 ¹³ Ω cm Specific resistance after heating accelerated test: 5.6 × 10 ¹³ Ω cm Specific resistance after ultraviolet irradiation accelerated test: 2.6 × 10 ¹³ Ω cm Voltage holding ratio before test: 99. 3% Voltage holding ratio after heating accelerated test: 98.6% Voltage holding ratio after ultraviolet irradiation accelerated test: 98.3% Fabrication of active matrix liquid crystal display device using this nematic liquid crystal composition (3-7) as a constituent material. As a result, it was confirmed that the leakage current was small and the flicker did not occur.

(Embodiment 8)

[0148]

Embedded image

A nematic liquid crystal composition (3-8) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 85.4 ° C. T → _N : <−70 ° C. V _th : 1.39 V Δε: 8.9 Δn: 0.087 Pr _-25 : 30 days Pr _-40 : 30 days

(Example 9)

[0151]

[Chemical 49]

A nematic liquid crystal composition consisting of (3-9)
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 86.9 ° C. T → _N : <−70 ° C. V _th : 1.37 V Δε: 9.6 Δn: 0.089 Pr ₋₂₅ : 30 days Specific resistance before test: 7.6 × 10 ¹³ Ω cm Specific resistance after accelerated heating test: 5.8 × 10 ¹³ Ω cm Specific resistance after ultraviolet irradiation accelerated test: 2.9 × 10 ¹³ Ω cm Voltage holding ratio before test: 99.5% After accelerated heating test Voltage holding ratio: 98.8% Voltage holding ratio after ultraviolet irradiation accelerated test: 98.4% When an active matrix liquid crystal display device using the nematic liquid crystal composition (3-9) as a constituent material was produced, the leakage current was It was confirmed that it was small and excellent without flicker.

(Example 10)

[0154]

Embedded image

A nematic liquid crystal composition (3-1
0) was prepared and various properties of this composition were measured. The results were as follows. T _NI : 94.6 ° C. T → _N : −70 ° C. V _th : 1.69 V Δε: 6.5 Δn: 0.082 Pr ₋₂₅ : 30 days

(Example 11)

[0157]

[Chemical 51]

A nematic liquid crystal composition (3-1
1) was prepared and various properties of this composition were measured. The results were as follows. T _NI : 85.7 ° C. T → _N : −40 ° C. V _th : 1.46 V Δε: 7.4 Δn: 0.077 Pr _-25 : 30 days

(Example 12)

[0160]

Embedded image

A nematic liquid crystal composition (3-1
2) was prepared and various properties of this composition were measured. The results were as follows. T _NI : 95.6 ° C. T → _N : −40 ° C. V _th : 1.63 V Δε: 7.3 Δn: 0.075 Pr _-25 : 14 days Specific resistance before test: 7.2 × 10 ¹³ Ω cm Specific resistance after accelerated heating test: 4.8 × 10 ¹³ Ω cm Specific resistance after accelerated ultraviolet irradiation test: 5.1 × 10 ¹³ Ω cm Voltage holding ratio before test: 99.0% Voltage after accelerated heating test Retention rate: 98.2% Voltage retention rate after ultraviolet irradiation accelerated test: 98.3% When an active matrix liquid crystal display device using the nematic liquid crystal composition (3-12) as a constituent material was produced, the leakage current was small. It was confirmed to be excellent without flicker.

Further, this nematic liquid crystal composition (3-1
A liquid crystal composition was prepared by adding the chiral substance “S-811” (manufactured by Merck Ltd.) to 2). On the other hand, an organic film of "SAN EVER 150" (manufactured by Nissan Kagaku Co., Ltd.) was rubbed on the opposing flat transparent electrodes to form an alignment film, and an STN-LCD display cell with a twist angle of 220 degrees was produced. The liquid crystal composition was injected into this cell to form a liquid crystal display device, and the display characteristics were measured. As a result, a liquid crystal display device having a low threshold voltage, excellent high time division characteristics, and STN-LCD display characteristics with improved display screen flicker and crosstalk phenomenon was obtained. (Example 13)

[0163]

Embedded image

A nematic liquid crystal composition (3-1
3) was prepared and various properties of this composition were measured. The results were as follows. T _NI : 96.2 ° C. T → _N : −11 ° C. V _th : 1.71 V Δε: 7.0 Δn: 0.076 Pr ₋₂₅ : 3 days (Example 14)

[0165]

[Chemical 54]

A nematic liquid crystal composition (3-1)
4) was prepared and various properties of this composition were measured. The results were as follows. T _NI : 91.3 ° C. T → _N : −30 ° C. V _th : 1.40 V Δε: 8.6 Δn: 0.074 Pr _-25 : 3 days

[0167]

INDUSTRIAL APPLICABILITY The nematic liquid crystal composition of the present invention exhibits a nematic phase in a wide temperature range, has an improving effect of further maintaining the nematic liquid crystal property during long-term low temperature storage, and has a low threshold voltage and a high threshold voltage. It has a voltage holding ratio and high chemical stability. Therefore, the liquid crystal display device of the present invention using this can improve the flicker of the display screen and the crosstalk phenomenon, and has good driving characteristics in the TN-LCD, STN-LCD or the active matrix system with a large amount of information. And display characteristics are obtained.

Claims (35)

[Claims] (1) General formulas (I) to (III): (In the formula, each R ¹ independently represents a linear alkenyl group having 2 to 5 carbon atoms, R ² represents a linear alkyl group having 2 to 5 carbon atoms, and two 1's in each compound are represented. , At least one hydrogen atom (H) of the 4-cyclohexylene group may be substituted with a deuterium atom (D), and a compound selected from the first group consisting of compounds represented by (2) and Formulas (IV) to (VI) embedded image (In the formula, each of R ^3's independently represents a linear alkyl group having 2 to 7 carbon atoms, and
At least one hydrogen atom (H) of the 4-cyclohexylene group may be substituted with a deuterium atom (D). )
A compound selected from the second group consisting of the compounds represented by, and at least one of the compounds selected from the two groups is at least one hydrogen atom of two 1,4-cyclohexylene groups. (H) is a deuterium atom (D)
A nematic liquid crystal composition, which is a compound substituted with. 2. General formulas (I-1) to (VI-1): (In the formula, R ¹ independently represents a linear alkenyl group having 2 to 5 carbon atoms, R ² represents a linear alkyl group having 2 to 5 carbon atoms, and R ³ independently represents each other. Represents a linear alkyl group having 2 to 7 carbon atoms, and X ^{1 to} X ⁴
Each independently represent a hydrogen atom (H) or a deuterium atom (D), but at least one is a deuterium atom (D).
And X ^{5 to} X ⁷ are each independently a hydrogen atom (H).
Or represents a deuterium atom (D), but at least one represents a deuterium atom. 2.) A compound selected from the group consisting of compounds represented by
The described nematic liquid crystal composition. 3. The nematic liquid crystal composition according to claim 2, containing a compound selected from the group consisting of compounds represented by formulas (I-1) to (V-1). (3) General formulas (VII) and (VIII): (In the formula, R ^4's each independently represent a linear alkyl group having 2 to 5 carbon atoms, Y ^1's each independently represent a hydrogen atom or a fluorine atom, and two 1,4- At least one hydrogen atom (H) of the cyclohexylene group may be substituted with a deuterium atom (D)), and a compound selected from the third group consisting of compounds represented by the formula: Claim 1, 2 or 3
The described nematic liquid crystal composition. 5. A compound represented by the general formula (VIII-1): (In the formula, R ⁴ represents a linear alkyl group having 2 to 5 carbon atoms, Y ¹ represents a hydrogen atom or a fluorine atom, and X ¹ to
X ^4's each independently represent a hydrogen atom (H) or a deuterium atom (D), but at least one is a deuterium atom (D).
Represents 5. The nematic liquid crystal composition according to claim 4, further comprising a compound represented by (4) General formulas (IX) and (X) (In the formula, R ⁵ each independently represents an alkyl group having 3 to 7 carbon atoms, Y ¹ and Y ² each independently represent a hydrogen atom or a fluorine atom, and each of 1,4
At least one hydrogen atom (H) in the -cyclohexylene group may be substituted with a deuterium atom (D). ) A compound selected from the fourth group consisting of the compounds represented by
The nematic liquid crystal composition according to 4 or 5. 7. A compound selected from the first group is represented by the general formula:
The nematic liquid crystal composition according to claim 3, which is a compound represented by (I). 8. A compound selected from the first group is represented by the general formula (I:
A compound represented by I), which is characterized in that
Or the nematic liquid crystal composition according to item 4. 9. A compound selected from the first group is represented by the general formula (I:
The nematic liquid crystal composition according to claim 3, which is a compound represented by II). 10. A compound selected from the first group is represented by the general formula:
The nematic liquid crystal composition according to claim 3, 4 or 6, which is a compound represented by (I) or (II). 11. A compound selected from the first group is represented by the general formula:
The nematic liquid crystal composition according to claim 3, 4 or 6, which is a compound represented by (I) or (III). 12. A compound selected from the second group is represented by the general formula:
The nematic liquid crystal composition according to claim 3, which is a compound represented by (VI). 13. A compound selected from the second group is represented by the general formula:
The nematic liquid crystal composition according to claim 3, 4, 5, 6, 10 or 11, which is a compound represented by (IV) or (V). 14. A compound selected from the second group is represented by the general formula:
9. The nematic liquid crystal composition according to claim 3, which is a compound represented by (V) or (VI). 15. A compound selected from the second group is represented by the general formula:
11. The nematic liquid crystal composition according to claim 3, which is a compound represented by (IV), (V) and (VI). 16. General formula (III-1), general formula (III-2) and general formula (IV-1) (In the formula, R ² represents a linear alkyl group having 2 to 5 carbon atoms, and X ^{1 to} X ⁴ each independently represent a hydrogen atom (H) or a deuterium atom (D), and at least 1 Represents a deuterium atom (D), X ^{5 to} X ⁷ each independently represent a hydrogen atom (H) or a deuterium atom (D), and at least one represents a deuterium atom (D). 16. The nematic liquid crystal composition according to claim 15, further comprising a compound represented by the formula: 17. The nematic liquid crystal composition according to claim 16, wherein the compound represented by the general formula (III-1) is contained in the range of 5 to 40% by weight. 18. The nematic liquid crystal composition according to claim 16, which contains the compound represented by the general formula (III-2) in the range of 5 to 40% by weight. 19. A compound represented by the general formula (IV-1)
The nematic liquid crystal composition according to claim 16, wherein the nematic liquid crystal composition is contained in an amount of -40% by weight. 20. A compound selected from the third group is represented by the general formula:
The nematic liquid crystal composition according to claim 4, 6, 12, 13 or 15, which is a compound represented by (VII). 21. A compound selected from the third group is represented by the general formula:
The nematic liquid crystal composition according to claim 12, which is a compound represented by (VII) or (VIII). 22. A compound selected from the fourth group is represented by the general formula:
21. The nematic liquid crystal composition according to claim 20, which is a compound represented by (IX). 23. A compound selected from the fourth group is represented by the general formula:
22. The nematic liquid crystal composition according to claim 20, which is a compound represented by formula (X). 24. A compound selected from the fourth group is represented by the general formula:
22. The nematic liquid crystal composition according to claim 21, which is a compound represented by (IX) or (X). 25. (5) General formulas (XI) to (XV) (In the formula, each R ⁶ independently represents a linear alkyl group or alkenyl group having 2 to 5 carbon atoms, and each R ⁷ independently represents a linear alkyl group having 1 to 5 carbon atoms or an alkoxy group. Group or a linear alkenyl group having 2 to 5 carbon atoms, R ⁸ represents a linear alkyl group having 2 to 5 carbon atoms, r independently represents 0 or 1, and Y
¹ and Y ² each independently represent a hydrogen atom or a fluorine atom, and at least one hydrogen atom (H) of at least one 1,4-cyclohexylene group in each compound is replaced by a deuterium atom (D). May be. 7. The nematic liquid crystal composition according to claim 1, which contains a compound selected from the fifth group consisting of the compounds represented by the formula (1). 26. The general formulas (XIII) to (XV) according to claim 25.
26. The nematic liquid crystal composition according to claim 25, containing a compound selected from the group consisting of compounds represented by: 27. General formulas (XIV-1) and (XV-1) (In the formula, R ⁶ represents a linear alkyl group or alkenyl group having 2 to 5 carbon atoms, R ⁸ represents a linear alkyl group having 2 to 5 carbon atoms, and Y ¹ and Y ² are respectively Each independently represents a hydrogen atom or a fluorine atom, and X ^{1 to} X ⁴ each independently represent a hydrogen atom (H) or a deuterium atom (D), but at least one represents a deuterium atom (D). )
27. The nematic liquid crystal composition according to claim 26, which contains at least one compound represented by: 28. The nematic liquid crystal composition according to claim 20, wherein in the compound represented by the general formula (VII), Y ¹ represents a hydrogen atom. 29. The nematic liquid crystal composition according to claim 21, wherein Y ¹ in the general formula (VIII) represents a fluorine atom. 30. The nematic liquid crystal composition according to claim 22, wherein in the compound represented by the general formula (IX), Y ¹ and Y ² both represent a hydrogen atom. 31. The nematic liquid crystal composition according to claim 23, wherein in the compound represented by the general formula (X), Y ¹ represents a fluorine atom. 32. In the compound represented by formula (XIII), R ⁶ represents a linear alkenyl group having 2 to 5 carbon atoms, and R ⁷ represents a linear alkyl group having 1 to 5 carbon atoms. 27. The nematic liquid crystal composition according to claim 26, wherein 33. The compound represented by the general formula (XIV), wherein R ⁶ represents a linear alkyl group having 2 to 5 carbon atoms, and Y ¹ and Y ² both represent a hydrogen atom. The nematic liquid crystal composition according to claim 26 or 27. 34. An active matrix liquid crystal display device using the nematic liquid crystal composition according to claim 1. 35. A twisted nematic or super twisted nematic liquid crystal display device using the nematic liquid crystal composition according to claim 1.