JP2006037054A - Nematic liquid crystal composition and liquid crystal display element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal composition having negative dielectric anisotropy large in its absolute value and having low viscosity, and to provide a liquid crystal display element using the composition, such as a VA type. <P>SOLUTION: The liquid crystal composition comprises 35-70% compound represented by general formula (I) and 30-65% compound represented by general formula (II). (Wherein R<SP>1</SP>to R<SP>4</SP>are each an alkyl or the like; B<SP>1</SP>and B<SP>2</SP>are e.g. cyclohexylene; Y<SP>1</SP>and Y<SP>2</SP>are each a linking group; and m and p are each an integer of 0-2). By combination of the liquid crystal compounds, the liquid crystal composition having low viscosity and negative dielectric anisotropy is obtained while physical properties such as refractive index anisotropy are almost kept. By using the composition, the liquid crystal display element capable of keeping voltage retention high up to a high-temperature region and excellent in reliability is provided, and the display is much practical as a liquid crystal display for VA type, ECB type, IPS type and the like and especially effective for obtaining fast response without thinning the cell gaps. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a nematic liquid crystal composition having a negative dielectric anisotropy Δε useful as an electro-optical liquid crystal display material, and a liquid crystal display device using the same.

  The liquid crystal display element is used in various electric appliances for home use, measuring instruments, automobile panels, word processors, electronic notebooks, printers, computers, televisions, etc., including clocks and calculators. Typical liquid crystal display methods include TN (twisted nematic), STN (super twisted nematic), DS (dynamic light scattering), GH (guest / host), and IPS (in-plane switching). Type, OCB (optical compensation birefringence) type, ECB (voltage controlled birefringence) type, VA (vertical alignment) type, CSH (color super homeotropic) type, FLC (ferroelectric liquid crystal), etc. . As a driving method, multiplex driving is generally used instead of conventional static driving, and the active matrix (AM) method driven by a TFT (thin film transistor), TFD (thin film diode) or the like has become mainstream recently. ing.

  In these display systems, the IPS type, ECB type, VA type, CSH type and the like have a feature that a liquid crystal material having a negative dielectric anisotropy (Δε) is used, unlike currently-used TN type and STN type. . Among these, VA type display by AM driving is currently most expected in application to a display element that requires a high speed and a wide viewing angle, such as a television.

  A liquid crystal material used in a display method such as a VA type is required to have low voltage driving, high speed response, and a wide operating temperature range. That is, the dielectric anisotropy is negative, the absolute value is large, the viscosity is low, and a high nematic phase-isotropic liquid phase transition temperature (Tni) is required. In addition, it is necessary to adjust the refractive index anisotropy of the liquid crystal material to an appropriate range according to the cell gap from the setting of Δn × d, which is the product of the refractive index anisotropy (Δn) and the cell gap (d). is there. In the case of applying a liquid crystal display element to a television or the like, since high-speed response is important, a liquid crystal material having a low viscosity is required.

  As a liquid crystal material having a negative dielectric anisotropy, a liquid crystal compound having the following 2,3-difluorophenylene skeleton (see Patent Document 1) is disclosed.

（式中、R及びR'は炭素数１から１０のアルキル基又はアルコキシ基を表す。）
しかし、これらの化合物を用いた誘電率異方性が負の液晶組成物は、液晶テレビ等の高速応答が要求される液晶組成物においては十分に低い粘性を実現するに至っていない。

(In the formula, R and R ′ represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group.)
However, a liquid crystal composition having a negative dielectric anisotropy using these compounds has not yet achieved a sufficiently low viscosity in a liquid crystal composition that requires a high-speed response such as a liquid crystal television.

  On the other hand, although the compound represented by the general formula (I) of the present invention has already been disclosed (see Patent Document 2 and Patent Document 3), a liquid crystal composition can be obtained by using any of these compounds and other compounds. There is no specific disclosure as to whether the viscosity of can be reduced.

Further, a liquid crystal composition using the compound represented by the general formula (I) of the present invention has already been disclosed (see Patent Document 4 and Patent Document 5). There is no specific disclosure as to whether viscosity can be reduced by combining with a compound.
Accordingly, development of a liquid crystal composition having a negative dielectric anisotropy and a low viscosity has been desired.

JP-A-8-104869 JP-A-60-199840 JP 2000-96055 A European Patent Application No. 04744062 Special table 2-503568

  The problem to be solved by the present invention is to provide a liquid crystal composition having a negative dielectric anisotropy having a large absolute value, and having a low viscosity without reducing or increasing the refractive index anisotropy. Another object is to provide a VA type liquid crystal display element using the above.

The present invention, as a result of intensive studies to solve the above problems,
As the first component, the general formula (I)

(In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and one CH ₂ group present in these groups or two or more non-adjacent CHs. _Two groups may be substituted with O and / or S, and one or more hydrogen atoms present in these groups may be substituted with F or Cl, and R ² has 1 to Represents an alkyl group having 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 3 to 10 carbon atoms,
m represents 0, 1 or 2. )
1 type or 2 types or more of the compound represented by this, The content rate is 35 to 70 mass%,
As the second component, the general formula (II)

(式中、R³及びR⁴はそれぞれ独立的に一般式(I)におけるR²と同じ意味を表し、
B¹及びB²はそれぞれ独立的に
(a) トランス-1,4-シクロへキシレン基(この基中に存在する1個のCH₂基又は隣接していない2個のCH₂基は酸素原子又は硫黄原子に置換されてもよい)
(b) 1,4-フェニレン基(この基中に存在する1個又は2個以上のCH基は窒素原子に置換されてもよい)
(c) 1,4-シクロヘキセニレン基、1,4-ビシクロ[2.2.2]オクチレン基、ピペリジン-1,4-ジイル基、ナフタレン-2,6-ジイル基、デカヒドロナフタレン-2,6-ジイル基及び1,2,3,4-テトラヒドロナフタレン-2,6-ジイル基
からなる群より選ばれる基を表し、上記の基(a)、基(b)又は基(c)はCN又はハロゲンで置換されていてもよく、

(Wherein R ³ and R ⁴ each independently represent the same meaning as R ² in formula (I),
B ¹ and B ² are each independently
(a) trans-1,4-cyclohexylene group (two CH ₂ groups not one CH ₂ group or adjacent present in this group may be substituted with an oxygen atom or a sulfur atom)
(b) 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom)
(c) 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the group (a), the group (b) or the group (c) is CN or May be substituted with halogen,

Y ¹ and Y ² are independently
-CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH ₃ ) CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF-, -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,-(CH ₂ ) ₄ -,-(CH ₂ ) _{3 O -, - O (CH} 2) 3 -, - C≡C -, - CF 2 O -, - OCF 2 -, - COO -, - OCO -, - COS -, - SCO- or a single bond ,
When there are a plurality of Y ² and B ² , they may be the same or different,
p represents 0, 1 or 2. )
1 type or 2 types or more of the compound represented by these, The content rate is 30 to 65 mass%,
And content of 1 type or 2 or more types of compounds chosen from general formula (I) and 1 type or 2 or more types of compounds chosen from general formula (II) is 70 mass% or more,
A liquid crystal composition having a negative dielectric anisotropy is provided, and further, a liquid crystal display element using the liquid crystal composition is provided.

  By the combination of the liquid crystal compounds of the present invention, a liquid crystal composition having a low viscosity and a negative dielectric anisotropy was obtained while substantially maintaining the refractive index anisotropy. By using this composition, a highly reliable liquid crystal display element capable of maintaining a high voltage holding ratio up to a high temperature range is provided, and this display is very practical as a liquid crystal display of VA mode, ECB mode, IPS mode, etc. In particular, it is effective for high-speed response without reducing the cell gap.

  In the liquid crystal composition of the present invention, the first component contains one or more compounds represented by the general formula (I), preferably 1 to 20 types, more preferably 1 to 15 types. 1 to 10 types are more preferable, and 1 to 8 types are particularly preferable.

  The content of the compound represented by the general formula (I) is more preferably in the range of 35 to 65% by mass. These compounds have a negative dielectric anisotropy with a large absolute value, but if the content is large, there is a tendency to increase the viscosity, or the smectic-nematic phase transition temperature may be increased. When importance is attached to low viscosity, or when importance is attached to low smectic-nematic phase transition temperature, these contents are preferably small. When importance is attached to negative dielectric anisotropy having a large absolute value, these contents are preferred. It is preferable that there are many.

In general formula (I), R ¹ is an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkyl group having 1 to 7 carbon atoms substituted by an alkoxyl group having 1 to 5 carbon atoms. It preferably represents an alkenyl group having 2 to 7 carbon atoms substituted by an alkoxyl group having 1 to 5 carbon atoms, and more preferably represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. More preferably, it represents an alkyl group having 1 to 10 carbon atoms, and R ² represents an alkyl group having 1 to 10 carbon atoms, an alkoxyl group, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 3 to 10 carbon atoms. It is more preferable that it represents an alkyl group or alkoxyl group having 1 to 10 carbon atoms, more preferably an alkoxyl group having 1 to 10 carbon atoms, and m preferably represents 0 or 1.

  More specifically, the general formula (I) is preferably a compound represented by the following general formula (I-A) or general formula (I-B) as a specific structure.

(In the formula, R ⁵ , R ⁶ , R ⁷ and R ⁸ represent the same meaning as R ¹ in the general formula (I).)
As the second component, one or more compounds represented by the general formula (II) are contained, preferably 1 to 12 types, more preferably 1 to 8 types, and more preferably 1 to 6 types. Further preferred.

  The content of general formula (II) is more preferably in the range of 35 to 65% by mass. These compounds have little effect of increasing the absolute value of the dielectric anisotropy, but have the effect of lowering the viscosity. When importance is attached to increasing the absolute value of the property, it is preferable that these contents are small.

In general formula (II), R ³ and R ⁴ are each independently an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or 3 to 10 carbon atoms. R ³ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, R ⁴ represents an alkyl group having 1 to 10 carbon atoms, and 1 to carbon atoms. More preferably, it represents 10 alkoxyl groups or alkenyl groups having 2 to 10 carbon atoms,
Specifically, R ³ is -CH ₃ , -CH ₂ CH ₃ ,-(CH ₂ ) ₂ CH ₃ ,-(CH ₂ ) ₃ CH ₃ ,-(CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-( CH ₂ ) ₂ CH = CHCH ₃ (E form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form) or-(CH ₂ ) ₆ CH = CH ₂ Represent,
R ⁴ _{is, -CH 3, -CH 2 CH 3} , - (CH 2) 2 CH 3, - (CH 2) 3 CH 3, - (CH 2) 4 CH 3, - (CH 2) 5 CH 3, -(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) ₃ CH ₃ , -O (CH ₂ ) ₄ CH ₃ , -O (CH ₂ ) ₅ CH ₃ , -O (CH ₂ ) ₆ CH ₃ , -O (CH ₂ ) ₇ CH _3, -CH = CH ₂ , -CH = CHCH ₃ ( E-form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E-form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH More preferably, it represents ₃ (E form) or — (CH ₂ ) ₆ CH═CH ₂ .

B ¹ and B ² are each independently a trans-1,4-cyclohexylene group (one CH ₂ group present in this group or _two non-adjacent CH ₂ groups are substituted with oxygen atoms). 1,4-phenylene group (including one or more CH groups substituted by nitrogen atoms), 1,4-cyclohexenylene group 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6-diyl group, or 1,2,3,4 -It preferably represents a tetrahydronaphthalene-2,6-diyl group or a substituent in which these hydrogen atoms are substituted with fluorine atoms, trans-1,4-cyclohexylene group, 1,4-phenylene group, fluorine-substituted A 1,4-phenylene group or a 1,4-bicyclo [2.2.2] octylene group is more preferable.

Y ¹ and Y ² are each independently -CH ₂ CH _2- , -CH = CH- (E form), -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH ₃ ) CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF- (E form), -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH ( CH ₃ ) O-,-(CH ₂ ) ₄ -,-(CH ₂ ) ₃ O-, -O (CH ₂ ) _3- , -C≡C-, -CF ₂ O-, -OCF ₂ -,- COO-, -OCO-, -COS-, -SCO- or a single bond is preferred, but -CH ₂ CH _2- , -CH = CH- (E form), -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF- (E form), -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH ( CH ₃ ) O—, —C≡C—, —CF ₂ O—, —OCF ₂ — or a single bond is more preferable, and —CH ₂ CH ₂ —, —CH═CH— (E form) or a single bond is further preferable.

  More specifically, the general formula (II) is preferably a compound represented by the following general formula (II-A) to general formula (II-G) as a specific structure.

(In the formula, R ¹³ , R ¹⁵ , R ¹⁷ , R ¹⁹ , R ²¹ , R ²³ and R ²⁵ are —CH ₃ , —CH ₂ CH ₃ , — (CH ₂ ) ₂ CH ₃ , — (CH ₂ ) ₃ CH ₃ ,-(CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -CH = CH ₂ , -CH = CHCH ₃ (E-form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E-form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form) or — (CH ₂ ) ₆ CH═CH ₂ represents R ¹⁴ , R ¹⁶ , R ¹⁸ , R ²⁰ , R ²² , R ²⁴ and R ²⁶ are —CH ₃ , —CH ₂ CH ₃ ,-(CH ₂ ) ₂ CH ₃ ,-(CH ₂ ) ₃ CH ₃ ,-(CH ₂ ) ₄ CH ₃ ,-(CH ₂ ) ₅ CH ₃ ,-(CH ₂ ) ₆ CH ₃ ,-(CH ₂ ) ₇ CH ₃ , -OCH ₃ , -OCH ₂ CH ₃ , -O (CH ₂ ) ₂ CH ₃ , -O (CH ₂ ) ₃ CH ₃ , -O (CH ₂ ) ₄ CH ₃ , -O (CH ₂ ) ₅ CH ₃ , -O (CH ₂ ) ₆ CH ₃ , -O (CH ₂ ) ₇ CH _3, -CH = CH ₂ , -CH = CHCH ₃ (E form),-(CH ₂ ) ₂ CH = CH ₂ ,-(CH ₂ ) ₂ CH = CHCH ₃ (E form),-(CH ₂ ) ₄ CH = CH ₂ ,-(CH ₂ ) ₄ CH = CHCH ₃ (E form) or-(CH ₂ ) ₆ CH = CH ₂ is represented.)
As an additional component, it is also preferable to contain one or more compounds selected from the compound group consisting of general formulas (III-A) to (III-H).

（式中、R⁹及びR¹⁰は一般式（I）におけるR¹と同じ意味を表す。）

(In the formula, R ⁹ and R ¹⁰ represent the same meaning as R ¹ in the general formula (I).)

  The nematic liquid crystal composition of the present invention contains 35 to 70% by mass of one or more compounds selected from the general formula (I), from the general formula (II-A) to the general formula (II-G). It is preferable to contain 30 to 65% by mass of one or more compounds selected from the group consisting of:

  Contains 35 to 70% by mass of one or more compounds selected from the group consisting of general formula (IA) and general formula (IB), from general formula (II-A) to general formula (II-G) It is more preferable to contain 30 to 65% by mass of one or more compounds selected from the group consisting of:

  Contains 35 to 70% by mass of one or more compounds selected from the compound group consisting of general formula (I) or general formula (IA) and general formula (IB), from general formula (II-A) 30 to 65% by mass of one or more compounds selected from the group consisting of formula (II-G) is contained, and the total content is preferably 70% by mass or more, and more preferably 75% by mass or more. It is more preferable.

  In the present invention, the nematic phase-isotropic liquid phase transition temperature (Tni) is more preferably 75 ° C. or higher, and further preferably 80 ° C. or higher. The dielectric anisotropy (Δε) at 25 ° C. is more preferably −2.5 or less, and further preferably −3.0 or less. The refractive index anisotropy (Δn) at 25 ° C. is more preferably 0.10 or more and even more preferably 0.12 or more when it corresponds to a thin cell gap. In the case of dealing with a thick cell gap, it is more preferably 0.095 or less, and further preferably 0.085 or less. The viscosity is more preferably 20 mPa · s or less.

  The nematic liquid crystal composition is useful for a liquid crystal display element, particularly useful for an active matrix driving liquid crystal display element, and can be used for a VA mode, IPS mode or ECB mode liquid crystal display element.

  The nematic liquid crystal composition of the present invention may contain a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal and the like in addition to the above compounds.

  EXAMPLES The present invention will be described in further detail with reference to examples below, but the present invention is not limited to these examples. Further, “%” in the compositions of the following Examples and Comparative Examples means “% by mass”.

In the examples, the measured characteristics are as follows.
T _NI : Nematic-isotropic phase transition temperature (° C)
Δn: Birefringence at 25 ° C. Δε: Dielectric anisotropy at 25 ° C. η: Viscosity (mPa · s) (20 ° C.)
Example 1
A liquid crystal composition represented by the following structure was prepared and measured for physical properties.

実施例１の特性は、Tni：82.1℃、Δn：0.075、Δε：-3.4、η：18.5mPa・sであった。

The characteristics of Example 1 were Tni: 82.1 ° C., Δn: 0.075, Δε: −3.4, η: 18.5 mPa · s.

(Comparative Example 1)
As Comparative Example 1, a liquid crystal composition represented by the following structure not containing the compound represented by the general formula (I) was prepared, and the physical properties thereof were measured.

比較例１の特性は、Tni：49.5℃、Δn：0.076、Δε：-3.0、η：23.1mPa・sであった。
比較例１は、実施例１と比べて、小さいΔｎ、絶対値が大きな負のΔε、および低い粘度を有するがTniが低く実用的な液晶組成物では無いことがわかる。

The characteristics of Comparative Example 1 were Tni: 49.5 ° C., Δn: 0.076, Δε: -3.0, and η: 23.1 mPa · s.
It can be seen that Comparative Example 1 is not a practical liquid crystal composition having a small Δn, a large negative Δε having a large absolute value, and a low viscosity but a low Tni compared to Example 1.

(Example 2)
A liquid crystal composition represented by the following structure was prepared and measured for physical properties.

実施例２の特性は、Tni：90.9℃、Δn：0.096、Δε：-3.0、η：18.2mPa・sであった。

The characteristics of Example 2 were Tni: 90.9 ° C., Δn: 0.096, Δε: −3.0, and η: 18.2 mPa · s.

(Comparative Example 2)
As Comparative Example 2, a liquid crystal composition represented by the following structure, in which the content of the general formula (I) is outside the scope of the claims, was prepared, and the physical properties thereof were measured.

The characteristics of Comparative Example 2 were Tni: 91.2 ° C., Δn: 0.095, Δε: −2.6, η: 18.0 mPa · s.
Although Example 2 has negative Δε having a larger absolute value than Comparative Example 2, Δn, Tni, and viscosity are almost the same as Comparative Example 2 and have excellent characteristics. I understand that.
(Example 3)

実施例３の特性は、Tni：81.4℃、Δn：0.076、Δε：-3.7、η：18.8mPa・sであった。

The characteristics of Example 3 were Tni: 81.4 ° C., Δn: 0.076, Δε: −3.7, η: 18.8 mPa · s.

Example 4
A liquid crystal composition represented by the following structure was prepared and measured for physical properties.

実施例４の特性は、Tni：84.3℃、Δn：0.075、Δε：-4.8、η：20.0mPa・sであった。

The characteristics of Example 4 were Tni: 84.3 ° C., Δn: 0.075, Δε: −4.8, η: 20.0 mPa · s.

(Example 5)
A liquid crystal composition represented by the following structure was prepared and measured for physical properties.

実施例５の特性は、Tni：84.9℃、Δn：0.078、Δε：-6.0、η：24.2mPa・sであった。

The characteristics of Example 5 were Tni: 84.9 ° C., Δn: 0.078, Δε: −6.0, and η: 24.2 mPa · s.

(Example 6)
A liquid crystal composition represented by the following structure was prepared and measured for physical properties.

実施例６の特性は、Tni：84.5℃、Δn：0.074、Δε：-4.5、η：18.7mPa・sであった。

The characteristics of Example 6 were Tni: 84.5 ° C., Δn: 0.074, Δε: −4.5, and η: 18.7 mPa · s.

(Comparative Example 3)
As Comparative Example 3, a liquid crystal composition represented by the following structure, in which the contents of the general formula (I) and the general formula (II) are outside the scope of the claims, was prepared, and the physical properties thereof were measured.

The characteristics of Comparative Example 3 were Tni: 84.7 ° C., Δn: 0.086, Δε: -9.5, and η: 42.1 mPa · s.
Comparative Example 3 is superior in that it has Δε having a larger absolute value than the Example of the present invention, but it can be seen that the viscosity is very high.

Claims (9)

As the first component, the general formula (I)

(In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and one CH ₂ group present in these groups or two or more non-adjacent CHs. _Two groups may be substituted with O and / or S, and one or more hydrogen atoms present in these groups may be substituted with F or Cl, and R ² has 1 to Represents an alkyl group having 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkenyloxy group having 3 to 10 carbon atoms,
m represents 0, 1 or 2. )
1 type or 2 types or more of the compound represented by this, The content rate is 35 to 70 mass%,
As the second component, the general formula (II)

(Wherein R ³ and R ⁴ each independently represent the same meaning as R ² in formula (I),
B ¹ and B ² are each independently
(a) trans-1,4-cyclohexylene group (two CH ₂ groups not one CH ₂ group or adjacent present in this group may be substituted with an oxygen atom or a sulfur atom)
(b) 1,4-phenylene group (one or more CH groups present in this group may be substituted with a nitrogen atom)
(c) 1,4-cyclohexenylene group, 1,4-bicyclo [2.2.2] octylene group, piperidine-1,4-diyl group, naphthalene-2,6-diyl group, decahydronaphthalene-2,6 Represents a group selected from the group consisting of a -diyl group and a 1,2,3,4-tetrahydronaphthalene-2,6-diyl group, and the group (a), the group (b) or the group (c) is CN or May be substituted with halogen,
Y ¹ and Y ² are independently
-CH ₂ CH _2- , -CH = CH-, -CH (CH ₃ ) CH _2- , -CH ₂ CH (CH ₃ )-, -CH (CH ₃ ) CH (CH ₃ )-, -CF ₂ CF _2- , -CF = CF-, -CH ₂ O-, -OCH _2- , -OCH (CH ₃ )-, -CH (CH ₃ ) O-,-(CH ₂ ) ₄ -,-(CH ₂ ) _{3 O -, - O (CH} 2) 3 -, - C≡C -, - CF 2 O -, - OCF 2 -, - COO -, - OCO -, - COS -, - SCO- or a single bond ,
When there are a plurality of Y ² and B ² , they may be the same or different,
p represents 0, 1 or 2. )
1 type or 2 types or more of the compound represented by these, The content rate is 30 to 65 mass%,
And content of 1 type or 2 or more types of compounds chosen from general formula (I) and 1 type or 2 or more types of compounds chosen from general formula (II) is 70 mass% or more,
A nematic liquid crystal composition having a negative dielectric anisotropy. General formula (IA) and general formula (IB)

(In the formula, R ⁵ , R ⁶ , R ⁷ and R ⁸ represent the same meaning as R ¹ in the general formula (I).)
The nematic liquid crystal composition of Claim 1 containing the 1 type, or 2 or more types of compound chosen from the compound group represented by these. From general formula (II-A) to general formula (II-G)

(In the formula, R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ²⁶ are represented by the general formula (I ) in the same meaning as R ^2.) 1 kind selected from the group of compounds represented by or claim 1 or 2 nematic liquid crystal composition according to contain two or more compounds. Contains 35 to 70% by mass of one or more compounds selected from the group consisting of general formula (IA) and general formula (IB), from general formula (II-A) to general formula (II-G) 4. The nematic liquid crystal composition according to claim 3, comprising 30 to 65% by mass of one or more compounds selected from the group consisting of: From general formula (III-A) to general formula (III-H)

(In the formula, R ⁹ and R ¹⁰ represent the same meaning as R ¹ in the general formula (I).)
The nematic liquid crystal composition according to claim 4, further comprising one or more compounds selected from the group consisting of: Dielectric anisotropy Δε at 25 ° C. is in the range of −2.0 to −6.0, refractive index anisotropy Δn at 25 ° C. is in the range of 0.06 to 0.16, and viscosity at 20 ° C. is in the range of 10 to 25 mPa · s. 6. The nematic liquid crystal composition according to claim 1, wherein the nematic phase-isotropic liquid phase transition temperature Tni is in the range of 70 ° C. to 120 ° C. 6. A liquid crystal display device using the nematic liquid crystal composition according to claim 1. A liquid crystal display element for active matrix driving using the nematic liquid crystal composition according to claim 1. A liquid crystal display element for VA mode, IPS mode or ECB mode, using the nematic liquid crystal composition according to claim 1.