JPH0881680A - Nematic liquid crystal composition and liquid crystal display device using the same - Google Patents

Abstract

(57) [Summary] [Structure] (1) General formulas (I-1) and (I-2) A compound selected from the first group of (2) and the general formula (II-1)
~ (II-3) [Chemical 2] A nematic liquid crystal composition containing a compound selected from the second group, and at least one of them is a compound having a deuterium atom (D). [Effect] The temperature range of the nematic phase is wide, and the nematic liquid crystallinity can be maintained for a long time even at low temperature storage. Moreover, the threshold voltage is low and the chemical stability is high. Therefore, it is useful as a constituent material of TN-LCDs, STN-LCDs, and portable LCDs that have a large amount of information.

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 provided. (Hereinafter, these active matrix display type liquid crystal display elements are collectively referred to as TFT-LCD.) In order to deal with such display elements, new liquid crystal compounds or liquid crystal compositions have been proposed. .

[0004]

With the spread of applied products of TN-LCD and STN-LCD, there is a need for a liquid crystal material which can operate at a low drive voltage of 1.4 V or less. For example, a display of a portable device, a personal computer, or the like is required to have good driving characteristics with a high time division number. However, such a liquid crystal material deteriorates response characteristics due to increase in viscosity, flickering of display and crosstalk phenomenon due to increase in capacitance component of each pixel, and decrease in resistance value of liquid crystal material prepared at low voltage. However, there are problems such as heat resistance and light resistance. In order to obtain such characteristics, for example, the compound of the following general formula (a-1) has been frequently used.

[0005]

[Chemical 6]

(In the formula, R represents a straight-chain alkyl group.) Further, the present inventors have proposed a fluorotolan compound such as the general formula (I-1) according to the present invention. -40
Only the physical properties and the like are disclosed in Japanese Patent Publication No. 97, and the properties and the like of compositions using the same are not yet known.

The problem to be solved by the present invention is to meet the above-mentioned problems, and particularly, the threshold voltage is 1.4V.
A low liquid crystal composition and a liquid crystal display device using the same are provided below.

[0008]

In order to solve the above-mentioned problems, the present invention provides (1) as a first liquid crystal composition of the present invention.
General formulas (I-1) and (I-2)

[0009]

[Chemical 7]

(In the formula, R ¹¹ represents a linear alkyl group having 2 to 7 carbon atoms, an alkenyl group or C _p H _{2 p + 1} OC _q H _2q , and R ¹² has 2 to 7 carbon atoms. Represents a straight chain alkyl group or alkenyl group, and p and q are each independently 1
To X 5, X ¹¹ and X ¹² each independently represent a hydrogen atom or a fluorine atom, Y ¹¹ represents a fluorine atom,
Represents a chlorine atom or a trifluoromethyl group, at least one of Z ¹¹ and Z ¹² represents a single bond, the other represents a single bond, —C ₂ H ₄ — or —C ₄ H ₈ —, and f is 0 or Represents 1. And a compound selected from the first group consisting of the compounds represented by the formula (2) and the general formulas (II-1) to (II-3)

[0011]

Embedded image

(In the formula, R ²¹ and R ²³ each independently represent a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, and R ²² is a linear alkyl group having 2 to 7 carbon atoms. , Alkenyl group or C _r H _{2r + 1} OC _s H _2s , r
And s each independently represent an integer of 1 to 5, and X ²¹
To X ²³ each independently represent a hydrogen atom or a fluorine atom, and g represents 0 or 1. ) Containing a compound selected from the second group consisting of compounds represented by the formula (1), and at least one of the compounds selected from the two groups is
Provided is a nematic liquid crystal composition, which is a compound in which at least one hydrogen atom (H) of a 1,4-cyclohexylene group is substituted with a deuterium atom (D).

In the compounds represented by the above general formulas (I-1) to (II-3) and the general formulas (III-4) and (IV-2) to (IV-4) described later, a hydrogen atom (H Representative compounds of compounds having a 1,4-cyclohexylene group in which) is substituted with a deuterium atom (D) are shown below. Incidentally, among these compounds,
Formula (b-1)

[0014]

[Chemical 9]

The cyclohexane ring represented by the formula (b) has a deuterium atom (D) with a probability corresponding to the abundance ratio to the naturally existing hydrogen atom having a mass number of 1, and is represented by the formula (b)
-2)

[0016]

[Chemical 10]

The cyclohexane ring represented by means that it has a deuterium atom (D) at the position indicated by D with a probability significantly different from the ratio existing in nature. Hereinafter, in the present invention, these two cyclohexane rings are used with the same definition.

[0018]

[Chemical 11]

[0019]

[Chemical 12]

(Wherein R ¹¹ , R ¹² , R ²² , R ³⁴ , R ⁴² ,
R ⁴³ , R ⁴⁴ , X ¹¹ , X ¹² , X ²² , X ⁴² , X ⁴³ , X ⁴⁴ , Y
¹¹ and Y ³⁴ have the same meanings as described above. ) The present invention provides the second liquid crystal composition, which includes (3) the general formulas (III-1) to (III-5) as the third component which can be added to the first liquid crystal composition.

[0021]

[Chemical 13]

(In the formula, R ^{31 to} R ³⁵ each independently represent a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, X ³¹ represents a hydrogen atom, a fluorine atom or CH ₃ ; ^{3 1} to Y ³³ are each independently a linear alkyl group having 2 to 7 carbon atoms, an alkoxy group, an alkenyl group or an alkenyloxy group, Y ³⁴ and Y ³⁵ are each independently 2 carbon atoms 7 linear alkyl group, alkoxy group, alkenyl group, alkenyloxy group or C _t H
_{2t + 1} OC ₂ H ₄ O, t represents an integer of 1 to 5,
h, i and j each independently represent 0 or 1. )
A nematic liquid crystal composition containing a compound selected from the third group consisting of the compounds represented by:

As the third liquid crystal composition of the present invention,
As the fourth component which can be added to the above-mentioned first or second liquid crystal composition, (4) general formulas (IV-1) to (IV-5)

[0024]

Embedded image

(In the formula, R ^{41 to} R ⁴⁴ each independently represent a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, and R ⁴⁵ is a linear alkyl group having 2 to 7 carbon atoms. ,
Represents an alkenyl group or C _u H _{2u + 1} OC _v H _2v , u and v each independently represent an integer of 1 to 5, and X ^{41 to} X
⁴⁴ each independently represents a hydrogen atom or a fluorine atom, k represents 0, 1 or 2, and l and m each independently represent 0 or 1. And a nematic liquid crystal composition containing a compound selected from the fourth group consisting of the compounds represented by

Further, the present invention provides the above-mentioned first, second or third.
There is provided a twisted nematic or super twisted nematic liquid crystal display device using the nematic liquid crystal composition.

General formulas (I-1) to (II-3) according to the present invention
Representative compounds represented by are shown in Table 1 below. In the table below, mp represents the temperature at which the crystal phase transitions to the liquid crystal phase or the isotropic liquid phase, and cp represents the temperature at which the liquid crystal phase transitions to the isotropic liquid phase. In addition, each liquid crystal compound was used after being sufficiently purified by removing impurities by methods such as distillation, column purification, and recrystallization.

[0028]

[Table 1]

The liquid crystal composition of the present invention is characterized by the general formula (I-
1) and a compound selected from the first group consisting of the compounds represented by (I-2) and a compound selected from the second group consisting of the compounds represented by the general formulas (II-1) to (II-3). It is used in combination as an essential component. The liquid crystal composition thus obtained can exhibit the characteristics that the threshold voltage is 1.4 V or less.

In order to show this, the following liquid crystal composition (2-1) and mixed liquid crystals (2-2) to (2-4) for comparison were prepared, and the results of measurement of the characteristics were shown. Show. still,
The meaning of each symbol of the measured characteristics is as follows.

T _NI : Nematic phase-isotropic liquid phase transition temperature (° C.) V _th : TN-LCD threshold voltage (V) when the thickness of the liquid crystal layer is 8 μm Δε: Dielectric anisotropy Δn : Birefringence τr = τd: Rise time τr from when no voltage is applied until light passes through when voltage is applied, and fall time when light is no longer transmitted except when voltage is applied. Response time (msec) when τd becomes equal

[0032]

[Chemical 15]

T _NI : 65.9 ° C. V _th : 1.05 V Δε: 15.1 Δn: 0.111 τr = τd: 58.9 msec

[0034]

Embedded image

T _NI : 65.0 ° C. V _th : 1.43 V Δε: 15.4 Δn: 0.142 τr = τd: 57.2 msec

[0036]

[Chemical 17]

T _NI : 62.9 ° C. V _th : 1.95 V Δε: 4.2 Δn: 0.095 τr = τd: 55.5 msec

[0038]

[Chemical 18]

T _NI : 44.0 ° C. V _th : 1.00 V Δε: 18.1 Δn: 0.110 τr = τd: 91.4 msec The liquid crystal composition (2-1) is the nematic liquid crystal of the present invention. It is a composition. The liquid crystal composition (2-2) outside the present invention is the same as the liquid crystal composition "ZLI-1132" (manufactured by Merck & Co., Inc.) which is composed of the compound represented by the general formula (II-2) according to the present invention. The compound represented by the formula (II-1) was added in an amount equal to that of the liquid crystal composition (2-1). Liquid crystal composition (2-
3) and (2-4) are the addition amount of the compound of the general formula (II-1) according to the present invention to the liquid crystal material “DON-103” (manufactured by RODIC Co., Ltd.) which is composed of an ester compound other than the present invention It was added by changing. The liquid crystal compositions (2-2) to (2-4) are typical liquid crystal materials that are currently widely used.

The liquid crystal compositions (2-1) to (2-3) have almost the same nematic phase-isotropic liquid phase transition temperature. However, it is clear that the liquid crystal composition (2-1) of the present invention has the lowest threshold voltage and is excellent. Regarding the response speed, the liquid crystal composition (2-1) of the present invention is the same as the liquid crystal composition (2-2).
It was almost the same as (2-3). Therefore, it is clear that the liquid crystal composition of the present invention is the most excellent.

The liquid crystal composition (2-4) is the liquid crystal composition (2-1)
Although the threshold voltage is almost the same as, the dielectric anisotropy is large. Therefore, it is clear that the liquid crystal composition of the present invention can further reduce the capacitance component of each pixel and improve the durability.

The reason why such excellent characteristics can be obtained is the effect of the combination of the compounds selected from the first group and the second group, and the nematic liquid crystal composition which can be driven at a low voltage according to the present invention. It indicates that the product can be prepared.

Further characteristics of the liquid crystal composition of the present invention are as follows:
A liquid crystal composition containing a compound selected from the group and a compound selected from the second group as an essential component has a property of inducing and expanding a nematic phase particularly at a low temperature, and has a nematic liquid crystal property for a longer period even when stored at a low temperature. There is a point that can be retained.

The compound represented by the general formula (I-1) has a dielectric anisotropy Δε in the range of 15 to 25 and has a fluorotolan structure. This compound has a unique property in compatibility with liquid crystal materials. For example, when it is combined with the following general formulas (2-5) to (2-7), an induced crystal phase or a partially crystallized smectic phase Is expressed,
On the contrary, there was a problem that the liquid crystal phase was narrowed, which was unsuitable as a combination.

[0045]

[Chemical 19]

(In the formula, R represents an alkyl group, and R'represents an alkyl group or an alkoxy group.) However, when combined with other compounds according to the present invention, the compatibility that induces and expands a nematic phase at a low temperature side. And has the effect of maintaining or reducing the drive voltage. Particularly, regarding the compatibility, it is effective and more preferable to use the compound of the general formula (I-2) together.

The compound represented by the general formula (I-2) is
Having a 3,4,5-trifluorophenyl group
It In this compound, R¹²Is an alkyl group, and
Tsu Z¹¹And Z¹²A compound with a single bond is suitable for long-term low temperature storage.
However, there was a problem that crystal precipitation was observed. We have
As a method to solve this problem, R¹²Is an alkenyl group
Yes, and Z¹¹And Z¹²Is a single bond compound, R¹²Is
Rukiru group and Z ¹¹And Z¹²One side is -C₂H_Fouror
Is -C_FourH₈-And the other is a compound with a single bond
And induce and expand the nematic phase at low temperature
It has already been clarified that it has a special effect. General formula
Represented by the compound represented by (I-2) and the second compound group
The liquid crystal composition of the present invention in combination with the compound
It has been found that the solubility becomes more significant.

In the compounds of the general formulas (I-1) and (I-2) in which R ¹¹ and R ¹² are alkenyl groups, the elastic constant ratios (K ₃₃ / K ₁₁ ) which play an important role in display characteristics are compared. A liquid crystal composition having a relatively large or small characteristic and exhibiting an elastic constant ratio according to the application can be prepared. Furthermore, since the viscosity of the liquid crystal composition can be lowered, a liquid crystal material having a high-speed response can be easily obtained. The following compounds are particularly excellent as such compounds.

[0049]

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The superiority of the present invention as described above will be made clearer in comparison with the technique disclosed in, for example, Japanese Patent Publication No. 5-501735. According to this, the content of the compound having a 3,4,5-trifluorophenyl group is 50% by weight.
The following is preferable. Therefore, although the lower threshold voltage is a problem, it has not yet been sufficiently reduced, 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 compound of the first group having a 3,4,5-trifluorophenyl group in the present invention has a total content of 50.
%, It is possible to prepare a nematic liquid crystal composition that can be used in a wide temperature range.

The second characteristic of the liquid crystal composition of the present invention is the first
At least one compound selected from the group and the second group uses a compound in which at least one hydrogen atom (H) of a 1,4-cyclohexylene group is replaced with a deuterium atom (D). It is in. 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 inventors of the present invention have disclosed such effects of a compound having such a deuterium atom (D) in Japanese Patent Application No. 5-10.
Although it was clarified in Japanese Patent No. 4144, Japanese Patent Application No. 5-182734, 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 will retain the nematic liquid crystallinity for a long time even if it is stored at -25 ° C or -40 ° C, which will be described in detail in Examples below. Is what you can do.

Further, the compounds represented by the general formulas (I-1) to (II-3) having a deuterium atom (D) are more significant than compounds not substituted by a deuterium atom. It shows certain elastic constants and their ratio, or an advantageous threshold voltage, and can be adjusted to have electro-optical characteristics according to the application.

The compounds represented by the general formulas (III-1) to (IV-5) 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 and the like. Have the effect of

More specifically, the compounds represented by the general formulas (III-1) to (III-4) are prepared by optimizing the birefringence (Δn) of the liquid crystal composition to 0.08 to 0.13 and It is possible to improve the viewing angle characteristics of the display device and increase the contrast ratio. 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. Furthermore, the response characteristics on the low temperature side can be improved.

The compound of the general formula (III-5) can reduce the color unevenness of the liquid crystal display device by optimizing the birefringence (Δn) of the liquid crystal composition to 0.10 to 0.24. .
Further, the liquid crystal composition thus obtained is used for a liquid crystal display device for color display by adjusting the birefringence of the retardation film and LCD proposed in Nikkei Microdevice January 1994 page 99. Is also useful.

The compounds of the general formulas (IV-1) to (IV-5) have a nematic phase temperature range of the liquid crystal composition above
Or it can be expanded to low temperature range and the birefringence (△ n)
Is useful for adjusting smaller or larger.

Further, the liquid crystal composition of the present invention has the general formula (I-
In addition to the compounds 1) to (IV-5), in order to improve other properties of the liquid crystal composition, a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal or the like recognized as a liquid crystal compound may be contained. .

The content of each compound in the liquid crystal composition of the present invention is 0 to 20 for the compound represented by the general formula (I-1).
% By weight of the compound represented by the general formula (I-2)
It is preferably contained in the range of wt%. General formula (II-
1 to 15% by weight of the compound represented by the general formula (II-
0 to 35% by weight of the compound represented by the formula (2), the general formula (II-
It is preferable to contain the compound represented by 3) in the range of 0 to 35% by weight.

The total content of each compound in the liquid crystal composition is 0 to 40% by weight of the compound group of the general formula (I-1),
It is preferable that the compound group of the general formula (I-2) is contained in the range of 0 to 80% by weight, and the compound group of the general formula (II-1) is 0%.
It is preferable that the content of the compound group of the general formula (II-2) is 0 to 70% by weight, and the compound group of the general formula (II-3) is 0 to 70% by weight.

More preferably, the compound group of the general formula (I-1) is 10 to 30% by weight, and the compound group of the general formula (I-2) is 2% by weight.
It is preferable that the content of the compound of the general formula (II-1) is 10 to 20% by weight,
The compound group of -2) is in the range of 5 to 20% by weight, and the compound group of general formula (II-3) is in the range of 5 to 30% by weight.

Further, the total content of each compound group is preferably such that the compounds of the first group of the general formulas (I-1) and (I-2) are contained in the range of 10 to 90% by weight. (II-1) ~
It is preferable to contain the compound of the second group (II-3) in the range of 5 to 70% by weight.

More preferably, the first group of compounds is 30 to
The content of the second group compound is preferably in the range of 5 to 40% by weight.

The compounds represented by the general formulas (III-1) to (III-5) are preferably contained in the range of 0 to 25% by weight. It is preferable that each of the compounds represented is contained in the range of 0 to 20% by weight.

Each compound according to the present invention is a liquid crystal composition.
Depending on the purpose required for liquid crystal display characteristics,
Can be combined. LCD threshold voltage
Pressure V _th[(I-1), (I-2)] + for the purpose of lowering
Combination of [(II-1) to (II-3)] + [(IV-1) to (IV-5)]
Alignment is preferable, and the threshold voltage V_thLower
For the purpose, combine the general formula (I-1) + (II-1)
And are particularly preferred. Purpose of speeding up response characteristics of liquid crystal display
Is [(I-1), (I-2)] + [(II-2) to (II-3)]
A combination of + [(III-1) to (III-4)] is preferable,
Further, it is preferable to combine the compound of general formula (VI-2).
Good The birefringence Δn of the liquid crystal composition is 0.08 to 0.13.
(I-2) + [(II-2) ~ (II-3)] +
A combination of [(III-1) to (III-4)] is preferable, and
Eyes having a birefringence index Δn of the crystal composition of 0.15 to 0.24
Specifically, (I-1) + [(II-1), (II-2)] + (III-5)
A combination of + (IV-5) is preferable.

The liquid crystal composition of the present invention thus obtained has a nematic phase-isotropic liquid phase transition temperature (T _NI ) of 60 to 100 ° C., as shown in Examples below. 1.1 to 1.4 V threshold voltage (V _th ), crystalline phase or smectic phase-nematic phase transition temperature (T → _N ) of −40 ° C. or lower, birefringence Δn of 0.08 to 0.20 The characteristics of can 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 performed, it was confirmed that after each acceleration test, it was chemically stable and had a high resistance value.

As described above, the nematic liquid crystal composition of the present invention exhibits liquid crystallinity in a wide temperature range and has a low threshold voltage, and further, by using this composition, a TN-LCD or STN-LCD liquid crystal display panel. It was confirmed that excellent display was possible when the above was manufactured.

[0069]

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 : TN-LCD when liquid crystal layer thickness is 8 μm Threshold voltage (V) Δε: Dielectric anisotropy Δn: Birefringence Pr _-25 : Time for having nematic property by storage at -25 ° C (days) Pr _-40 : Storage at -40 ° C Then, for the accelerated test of the composition, 2 g of the liquid crystal composition was put into an ampoule tube, deaerated in vacuum, and then subjected to a nitrogen substitution treatment and sealed.
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)

[0072]

[Chemical 21]

A nematic liquid crystal composition (3-1) comprising
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 60.7 ° C. T → _N : <−60 ° C. V _th : 1.07 V Δε: 16.2 Δn: 0.119 Pr _-25 : 30 days Pr _-40 : 30 days After heating accelerated test Specific resistance: 2.5 × 10 ¹¹ Ω c
m Specific resistance after UV irradiation acceleration test: 6.9 × 10 ¹⁰ Ω c
m A chiral substance "S-811" (manufactured by Merck) was added to this nematic liquid crystal composition (3-1) to prepare a mixed liquid crystal. On the other hand, on the opposite flat transparent electrode,
An organic film of "150" (manufactured by Nissan Chemical Co., Ltd.) was rubbed to form an alignment film, and a STN-LCD display cell with a twist angle of 220 degrees was produced. The above-mentioned mixed liquid crystal was injected into this cell to construct a liquid crystal display device, and 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 2)

[0075]

[Chemical formula 22]

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 : 94.6 ° C. T → _N : <−70 ° C. V _th : 1.10 V Δε: 18.2 Δn: 0.121 Pr _-25 : 30 days Pr- ₄₀ : 30 days

A chiral substance "S-811" (manufactured by Merck) was added to the nematic liquid crystal composition (3-2) to prepare a mixed liquid crystal. 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 above-mentioned mixed liquid crystal was injected into this cell to construct a liquid crystal display device, and display characteristics were measured. As a result, the STN-LCD has a low threshold voltage, excellent high time division characteristics, and improved display screen flicker and crosstalk.
A liquid crystal display device having display characteristics was obtained.

(Example 3)

[0079]

[Chemical formula 23]

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 : 97.2 ° C. T → _N : <−70 ° C. V _th : 1.35 V Δε: 14.0 Δn: 0.130 Pr _-25 : 30 days Pr- ₄₀ : 30 days

(Example 4)

[0082]

[Chemical formula 24]

A nematic liquid crystal composition (3-4) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 90.9 ° C. T → _N : <−70 ° C. V _th : 1.40 V Δε: 11.4 Δn: 0.123 Pr _-25 : 30 days Pr _-40 : 30 days

(Example 5)

[0085]

[Chemical 25]

A nematic liquid crystal composition (3-5) consisting of
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 83.3 ° C. T → _N : <−70 ° C. V _th : 1.39 V Δε: 9.7 Δn: 0.127 Pr _-25 : 30 days Pr- ₄₀ : 30 days

(Example 6)

[0088]

[Chemical formula 26]

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 : 76.4 ° C. T → _N : <−70 ° C. V _th : 1.19 V Δε: 15.9 Δn: 0.109 Pr _-25 : 30 days Pr- ₄₀ : 30 days

(Example 7)

[0091]

[Chemical 27]

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 : 80.0 ° C. T → _N : <−70 ° C. V _th : 1.12 V Δε: 15.7 Δn: 0.127 Pr _-25 : 30 days Pr- ₄₀ : 30 days

(Example 8)

[0094]

[Chemical 28]

A nematic liquid crystal composition consisting of (3-8)
Was prepared and various properties of this composition were measured. The results were as follows. T _NI : 77.9 ° C. T → _N : <−70 ° C. V _th : 0.98 V Δε: 22.3 Δn: 0.141 Pr _-25 : 30 days Pr- ₄₀ : 30 days

[0096]

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, has a low threshold voltage, and High chemical stability. Therefore, the liquid crystal display device of the present invention using this can obtain good display characteristics as a TN-LCD, STN-LCD or a portable LCD with a large amount of information.

Claims (19)

[Claims] (1) General formulas (I-1) and (I-2): (In the formula, R ¹¹ is a linear alkyl group having 2 to 7 carbon atoms,
Represents an alkenyl group or _{C p H 2 p + 1 OC} q H 2q, R 12 represents a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, p and q are each independently 1 to 5 Represents an integer, X ¹¹ and X ¹² each independently represent a hydrogen atom or a fluorine atom, Y ¹¹ represents a fluorine atom, a chlorine atom or a trifluoromethyl group, and at least one of Z ¹¹ and Z ¹² is a single bond. And the other is a single bond, -C ₂
H ₄ − or −C ₄ H ₈ − is represented, and f is 0 or 1. And a compound selected from the first group consisting of the compounds represented by the formula (2) and (2) the general formulas (II-1) to (II-3): (In the formula, R ²¹ and R ²³ each independently have 2 carbon atoms.
7 represents a linear alkyl group or an alkenyl group represented by R
²² is a linear alkyl group having 2 to 7 carbon atoms, an alkenyl group or a _{C r H 2r + 1 OC s} H 2s, r and s are each independently an integer of 1 to 5, X ²¹ ~ X ²³ each independently represents a hydrogen atom or a fluorine atom, and g represents 0 or 1. ) A compound selected from the second group consisting of compounds represented by the formula (1), and at least one of the compounds selected from the two groups is at least one hydrogen atom of a 1,4-cyclohexylene group ( A nematic liquid crystal composition, wherein H) is a compound in which a deuterium atom (D) is substituted. 2. The compound according to claim 1, wherein the compound selected from the second group is a compound selected from the group consisting of compounds represented by general formulas (II-1) and (II-2). Nematic liquid crystal composition. (3) General formulas (III-1) to (III-5): (In the formula, R ^{31 to} R ³⁵ each independently have 2 to 2 carbon atoms.
7 represents a linear alkyl group or alkenyl group represented by X ³¹
Represents a hydrogen atom, a fluorine atom or CH ^_3, Y ₃ ¹ ~Y
³³ independently represents a linear alkyl group having 2 to 7 carbon atoms, an alkoxy group, an alkenyl group or an alkenyloxy group, and Y ³⁴ and Y ³⁵ each independently represent a linear alkyl group having 2 to 7 carbon atoms. Jo alkyl group, an alkoxy group, an alkenyl group, alkenyloxy group or a _{C t H 2t + 1 OC 2} H 4 O
, T represents an integer of 1 to 5, and h, i and j each independently represent 0 or 1. The nematic liquid crystal composition according to claim 1 or 2, containing a compound selected from the third group consisting of the compounds represented by the formula (1). (4) General formulas (IV-1) to (IV-5): (In the formula, each of R ^{41 to} R ⁴⁴ independently has 2 to 2 carbon atoms.
7 represents a linear alkyl group or alkenyl group represented by R ⁴⁵
Linear alkyl group having 2 to 7 carbon atoms is, an alkenyl group or _{C u H 2u + 1 OC v} H 2v, u and v each independently represents an integer of 1 to 5, X ⁴¹ to X ⁴⁴ independently represents a hydrogen atom or a fluorine atom, and k is 0, 1
Or 2 and l and m are each independently 0 or 1.
Represents ) A compound selected from the fourth group consisting of the compounds represented by the formula 1) is contained.
Or the nematic liquid crystal composition according to item 3. 5. A compound obtained by substituting at least one hydrogen atom (H) of a 1,4-cyclohexylene group with a deuterium atom (D) has the general formula (1-2a) to (2-2a): Chemical 5] (In the formula, R ^12a represents a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, and R ^12b and R ^12c each independently represent a linear alkyl group having 2 to 7 carbon atoms. R ^22a is a compound selected from the group consisting of compounds represented by the formula: and R ^22a represents a straight-chain alkyl group having 2 to 7 carbon atoms.
Or the nematic liquid crystal composition according to item 4. 6. The nematic liquid crystal composition according to claim 5, wherein the compound selected from the second group is a compound represented by formula (II-1). 7. The nematic liquid crystal composition according to claim 5, wherein the compound selected from the second group is a compound represented by the general formula (II-2). 8. The nematic liquid crystal composition according to claim 5, wherein the compound selected from the second group is a compound represented by the general formula (II-1) or (II-2). 9. The nematic liquid crystal composition according to claim 7, wherein the compound selected from the third group is a compound represented by formula (III-4). 10. The nematic liquid crystal composition according to claim 8, wherein the compound selected from the third group is a compound represented by the general formula (III-1) or (III-4). 11. The nematic liquid crystal composition according to claim 6, wherein the compound selected from the fourth group is a compound represented by the general formula (IV-3). 12. The nematic liquid crystal composition according to claim 6, wherein the compound selected from the fourth group is a compound represented by formulas (IV-1) and (IV-3). 13. In the general formula (I-1), R ¹¹ represents a linear alkyl group having 2 to 7 carbon atoms, f represents 1, X ¹¹ and X ¹² both represent a hydrogen atom, The nematic liquid crystal composition according to claim 6, wherein Y ¹¹ represents a fluorine atom. 14. The nematic liquid crystal composition according to claim 6, wherein in the general formula (I-2), Z ¹¹ represents a single bond. 15. The nematic according to claim 6, 11, 12, 13 or 14, wherein R ²¹ in the general formula (II-1) represents a linear alkyl group having 2 to 7 carbon atoms. Liquid crystal composition. 16. In the general formula (III-1), R ³¹ represents a linear alkyl group having 2 to 7 carbon atoms, Y ³¹ represents a linear alkyl group having 2 to 7 carbon atoms, The nematic liquid crystal composition according to claim 10, 13 or 14, wherein h represents 0. 17. The compound represented by formula (IV-1), wherein R ⁴¹ represents a straight-chain alkyl group having 2 to 7 carbon atoms, and X ⁴¹ represents a hydrogen atom. Nematic liquid crystal composition. 18. The nematic according to claim 11, wherein in the general formula (IV-3), R ⁴³ represents a straight-chain alkyl group having 2 to 7 carbon atoms, and l represents 0. Liquid crystal composition. 19. A twisted nematic or super twisted nematic liquid crystal display device using the nematic liquid crystal composition according to claim 1.