JP2858340B2

JP2858340B2 - Liquid crystal composition

Info

Publication number: JP2858340B2
Application number: JP2025034A
Authority: JP
Inventors: 静一木崎
Original assignee: KASHIO KEISANKI KK
Current assignee: KASHIO KEISANKI KK
Priority date: 1990-02-06
Filing date: 1990-02-06
Publication date: 1999-02-17
Anticipated expiration: 2014-02-17
Also published as: JPH03229789A

Description

【発明の詳細な説明】（産業上の利用分野）本発明は液晶表示素子に用いられる誘電異方性が正の
液晶組成物に関する。Description: TECHNICAL FIELD The present invention relates to a liquid crystal composition having a positive dielectric anisotropy used for a liquid crystal display device.

（従来の技術と課題）電卓、時計等の表示装置として、液晶表示素子が広く
使用されている。この液晶表示素子に用いる液晶は、低
い電圧の印加によって高速度で応答する様に、誘電異方
性Δεの値が大きく（４〜12）、低粘度で（40cp以
下）、且つ、広い温度範囲で動作する様に、Ｃ−Ｎ点
（結晶相−ネマチック相の転移点）が低く（０℃以
下）、Ｎ−１点（ネマチック相−等方相の転移点）が高
い（60℃以上）ことが望まれている。これらの特性を満
足させるために、従来の結晶は、２つの環構造を持つ２
環の誘電異方性Δεが正に大きい液晶材料と、２つの環
構造を持つ２環の誘電異方性Δεが負、又はほとんど
「０」に近い低粘度の液晶材料と、３つの環構造を持つ
３環のＮ−Ｉ点が高い高温液晶材料とを、それぞれ配合
した液晶組成物が用いられている。(Prior Art and Problems) Liquid crystal display elements are widely used as display devices such as calculators and watches. The liquid crystal used in this liquid crystal display element has a large value of dielectric anisotropy Δε (4 to 12), a low viscosity (40 cp or less), and a wide temperature range so as to respond at a high speed when a low voltage is applied. The C-N point (transition point of crystal phase-nematic phase) is low (0 ° C. or less) and the N-1 point (transition point of nematic phase-isotropic phase) is high (60 ° C. or more) so as to operate at It is desired. In order to satisfy these properties, conventional crystals have two ring structures.
A liquid crystal material having a large positive ring dielectric anisotropy Δε, a low-viscosity liquid crystal material having a two-ring dielectric anisotropy Δε having a negative or almost zero value, and a three-ring structure And a high-temperature liquid crystal material having a high N-I point of three rings each having the following formula:

即ち、この液晶組成物は、２環の誘電異方性Δεが負
の液晶材料として、液晶組成物の粘度を低下させるため
に、低粘度であるが屈折率異方性Δｎの値が小さい、一
般式で表わされる液晶化合物が用いられ、そして、液晶素子
の印加電圧に対する透過光強度の変化の急峻性を良くす
るために屈折率異方性Δｎの値が大きいことが要求され
ているので、２環の誘電率異方性Δｎの値が正の液晶材
料として、屈折率異方正Δｎの大きな、一般式で表わされる液晶化合物が多量に配合され、誘電率異方
性Δεの値が正で特に大きな値をもつ、一般式で表わされる液晶化合物が小量配合され、さらに、３環
の高温液晶材料として、液晶組成物全体の屈折率異方性
の値を適性化するために屈折率異方性Δｎの値が0.13〜
0.15と大きく、誘電異方性Δεの値が正の、一般式で表わされる液晶化合物が配合されており、これらの液
晶材料の配合によって液晶組成物としての所望の特性を
得ようとしていた。That is, the liquid crystal composition has a low viscosity but a small value of the refractive index anisotropy Δn in order to reduce the viscosity of the liquid crystal composition as a liquid crystal material having a negative bicyclic dielectric anisotropy Δε. General formula And a large value of the refractive index anisotropy Δn is required in order to improve the steepness of the change in transmitted light intensity with respect to the applied voltage of the liquid crystal element. As a liquid crystal material having a positive value of the dielectric anisotropy Δn of the general formula A large amount of a liquid crystal compound represented by the formula, the value of dielectric anisotropy Δε is positive and has a particularly large value. Is mixed in a small amount, and as a three-ring high-temperature liquid crystal material, the value of the refractive index anisotropy Δn is 0.13 or more in order to optimize the value of the refractive index anisotropy of the entire liquid crystal composition.
The general formula is as large as 0.15 and the value of dielectric anisotropy Δε is positive. A liquid crystal compound represented by the formula (1) is blended, and the desired properties as a liquid crystal composition are to be obtained by blending these liquid crystal materials.

しかしながら、上述した様な従来の液晶組成物は、屈
折率異方性Δｎの値が大きい一般式（ｂ），（ｃ），
（ｅ），（ｆ）で表わされる液晶化合物の配合割合が多
く、これらの液晶化合物は誘電異方性Δεの値も大き
く、且つ粘度が高いためイオン性の不純物を取り込み易
く、液晶組成物の信頼性を低下させると共に粘度を十分
低くすることができなかった。また、一般式（ｅ）、
（ｆ）で表わされる屈折率異方性Δｎの値が大きく、誘
電異方性Δεの値が正である３環の液晶は、弾性定数Ｋ
の値が大きく、で表わされる液晶表示素子のしきい値電圧Vthを低下さ
せることができなかった。However, the conventional liquid crystal composition as described above has a large value of the refractive index anisotropy Δn in the general formulas (b), (c), and (c).
The compounding ratio of the liquid crystal compounds represented by (e) and (f) is large, and these liquid crystal compounds have a large value of dielectric anisotropy Δε, and have a high viscosity, so that ionic impurities are easily taken in. The reliability could not be reduced and the viscosity could not be sufficiently reduced. Also, the general formula (e),
The three-ring liquid crystal having a large value of the refractive index anisotropy Δn represented by (f) and a positive value of the dielectric anisotropy Δε has an elastic constant K
Is large, The threshold voltage Vth of the liquid crystal display element represented by the following expression could not be reduced.

その結果、従来の液晶組成物は、誘電異方性Δεの値
が大きい割には、弾性定数Ｋの値が大きいため、液晶表
示素子のしきい値電圧Vthを低下させることができず、
初期電流値が高く、消費電流が多いという欠点があり、
また誘電異方性Δεが負の液晶材料として低粘度の液晶
化合物を用いていても、屈折率異方性Δｎの値が大き
く、且つ粘度が高い液晶化合物を多量に配合しているた
め、粘度が十分低下せず応答速度が遅いという欠点があ
った。As a result, the conventional liquid crystal composition cannot reduce the threshold voltage Vth of the liquid crystal display element because the value of the elastic constant K is large in spite of the large value of the dielectric anisotropy Δε,
There is a drawback that the initial current value is high and the current consumption is large,
Even when a low-viscosity liquid crystal compound is used as the liquid crystal material having a negative dielectric anisotropy Δε, the value of the refractive index anisotropy Δn is large and a large amount of a high-viscosity liquid crystal compound is used. However, there was a disadvantage that the response speed was slow without being sufficiently reduced.

本発明は、上述した事情に鑑みてなされたもので、そ
の目的は、屈折率異方性Δｎの値が大きく、低粘度で、
低電圧の印加により高速応答させる液晶表示素子に適し
た液晶組成物を提供することである。The present invention has been made in view of the above-described circumstances, and has as its object a large value of refractive index anisotropy Δn, low viscosity,
It is an object of the present invention to provide a liquid crystal composition suitable for a liquid crystal display device that makes a high-speed response by applying a low voltage.

（課題を解決するための手段）本発明は、上記目的を達成するため、誘電異方性Δε
の値が正の液晶材料中、特に誘電異方性Δεの値が大き
く、且つ低粘度の液晶化合物と、誘電異方性Δεの値が
ほぼ０又は負の液晶材料中及び高温液晶材料中、屈折率
異方性Δｎの値が大きく、且つ低粘度の液晶化合物とを
配合したものであり、特に、屈折率異方性Δｎの値が大
きく、且つ低粘度の液晶化合物の配合割合を多くしたこ
とを特徴とする液晶組成物である。(Means for Solving the Problems) In order to achieve the above object, the present invention provides a dielectric anisotropy Δε.
In the positive liquid crystal material, especially the value of the dielectric anisotropy Δε is large, and a low viscosity liquid crystal compound, the value of the dielectric anisotropy Δε is almost 0 or in the negative liquid crystal material and in the high temperature liquid crystal material, A compound having a large value of the refractive index anisotropy Δn and a low-viscosity liquid crystal compound, and particularly having a large value of the refractive index anisotropy Δn and a large mixing ratio of the low-viscosity liquid crystal compound. A liquid crystal composition characterized by the following.

即ち、誘電異方性Δεの値が正に大きい液晶材料とし
ては、一般式（ここで、R¹は炭素数が２乃至３のアルキル基を示し、
R²は炭素数が２乃至５のアルキル基を示し、R³は炭素数
が２乃至４のアルキル基を示す。）で表わされる液晶化
合物が用いられる。特に、一般式（II）の液晶化合物
は、信頼性が高く、誘電異方性Δεの値が大きく、且つ
低粘度であるため多量に配合させることができる。これ
らの一般式（Ｉ），（II），（III）で表わされる液晶
化合物のうち、少なくとも２種（好ましくは異なる一般
式に属する少なくとも２種）を配合して第１の液晶材料
とする。That is, as a liquid crystal material having a positive value of the dielectric anisotropy Δε, a general formula (Where R ¹ represents an alkyl group having 2 to 3 carbon atoms,
R ² represents an alkyl group having 2 to 5 carbon atoms, and R ³ represents an alkyl group having 2 to 4 carbon atoms. ) Is used. In particular, the liquid crystal compound of the general formula (II) has a high reliability, a large value of dielectric anisotropy Δε, and a low viscosity, so that it can be incorporated in a large amount. Of the liquid crystal compounds represented by the general formulas (I), (II) and (III), at least two (preferably at least two types belonging to different general formulas) are blended to form a first liquid crystal material.

誘電異方性Δεの値が負の液晶材料としては、一般式、（ここで、R⁴は炭素数が３乃至５のアルキル基を示し、
R⁵は炭素数が１乃至６のアルキル基又はアルコキシ基を
示す。）で表わされる液晶化合物が用いられる。この一般式（I
V）の液晶化合物は、低粘度であるが屈折率異方性のΔ
ｎの値が小さい。この一般式（IV）で表わされる液晶化
合物のうち、少なくとも１種を用いて第２の液晶材料と
する。As a liquid crystal material having a negative value of dielectric anisotropy Δε, a general formula: (Where R ⁴ represents an alkyl group having 3 to 5 carbon atoms,
R ⁵ represents an alkyl group or an alkoxy group having 1 to 6 carbon atoms. ) Is used. This general formula (I
The liquid crystal compound of V) has a low viscosity but a refractive index anisotropy Δ
The value of n is small. At least one of the liquid crystal compounds represented by the general formula (IV) is used as a second liquid crystal material.

誘電異方性Δεの値がほぼ０である液晶材料として
は、一般式、（ここで、R⁶は炭素数が１乃至５のアルキル基を示し、
R⁷は、炭素数が１乃至６のアルキル基又はアルコキシ基
を示し、R⁸は炭素数が２乃至７のアルキル基を示し、R⁹
は炭素数が２乃至７のアルキル基又はアルコキシ基を示
す。）で表わされる液晶化合物が用いられる。これらの液晶化
合物は、屈折率異方性Δｎの値が大きく、特に一般式
（Ｖ）の液晶化合物は低粘度であり、比較的多量に配合
される。また、一般式（VI）の液晶化合物は弾性定数Ｋ
の値が小さい。これらの一般式（Ｖ），（VI）で表わさ
れる液晶化合物のうち、少なくとも１種を用いて第３の
液晶材料とする。Ｎ−Ｉ点が高い高温液晶材料として
は、一般式（ここで、R¹⁰は炭素数が３乃至５のアルキル基を示
し、R¹¹は炭素数が２のアルキル基を示し、R¹²及びR¹⁴
は炭素数が３のアルキル基を示し、R¹³は炭素数が４乃
至５のアルキル基を示し、R¹⁵は炭素数が２乃至４のア
ルキル基を示す。）で表わされる液晶化合物が用いられ
る。一般式（VII）の液晶化合物は、屈折率異方性Δｎ
の値が大きく、且つ、低粘度であり、一般式（IX）の液
晶化合物は、屈折率異方性Δｎの値が大きく、且つ弾性
定数Ｋの値が小さい。As a liquid crystal material having a value of dielectric anisotropy Δε of almost 0, a general formula: (Where R ⁶ represents an alkyl group having 1 to 5 carbon atoms,
R ⁷ has a carbon number of an alkyl group or an alkoxy group of 1 to 6, R ⁸ represents an alkyl group having 2 to 7 carbon atoms, R ⁹
Represents an alkyl group or an alkoxy group having 2 to 7 carbon atoms. ) Is used. These liquid crystal compounds have a large value of the refractive index anisotropy Δn, and particularly the liquid crystal compound of the general formula (V) has a low viscosity and is blended in a relatively large amount. The liquid crystal compound of the general formula (VI) has an elastic constant K
Is small. At least one of the liquid crystal compounds represented by the general formulas (V) and (VI) is used as a third liquid crystal material. As a high temperature liquid crystal material having a high NI point, a general formula (Where R ¹⁰ represents an alkyl group having 3 to 5 carbon atoms, R ¹¹ represents an alkyl group having 2 carbon atoms, and R ¹² and R ¹⁴
Represents an alkyl group having 3 carbon atoms, R ¹³ represents an alkyl group having 4 to 5 carbon atoms, and R ¹⁵ represents an alkyl group having 2 to 4 carbon atoms. ) Is used. The liquid crystal compound of the general formula (VII) has a refractive index anisotropy Δn
And the liquid crystal compound of the general formula (IX) has a large value of the refractive index anisotropy Δn and a small value of the elastic constant K.

これらの一般式（VII），（VIII）で表わされる液晶
化合物のうち、少なくとも１種を用いて第４の液晶材料
とする。A fourth liquid crystal material is formed using at least one of the liquid crystal compounds represented by the general formulas (VII) and (VIII).

本発明の液晶組成物は、上述した第１乃至第４の液晶
材料を、それぞれ、５乃至75重量％、10乃至50重量％、
５乃至40重量％、10乃至45重量％の割合で配合される。
望ましくは、第１乃至第４の液晶材料の配合割合が、そ
れぞれ、19乃至60重量％、10乃至25重量％、５乃至31重
量％、20乃至30重量％である。The liquid crystal composition of the present invention comprises the above-described first to fourth liquid crystal materials in an amount of 5 to 75% by weight, 10 to 50% by weight,
It is blended at a ratio of 5 to 40% by weight and 10 to 45% by weight.
Desirably, the compounding ratio of the first to fourth liquid crystal materials is 19 to 60% by weight, 10 to 25% by weight, 5 to 31% by weight, and 20 to 30% by weight, respectively.

また、本発明の液晶組成物は、第１の液晶材料として
一般式（II），及び（III）の液晶化合物と、第２の液
晶材料として一般式（IV）の液晶化合物と、第３の液晶
材料として一般式（Ｖ）の液晶化合物と、及び第４の液
晶材料として、一般式（VIII）又は一般式（VII），（V
III）に液晶化合物とを配合することによって達成され
る。この場合の配合割合は、一般式（II），（III），
（IV），（Ｖ），（VII），及び（VIII）の液晶化合物
がそれぞれ、30重量％、15重量％、15乃至20重量％、10
乃至15重量％、10重量％未満、20重量％である。Further, the liquid crystal composition of the present invention comprises a liquid crystal compound of the general formulas (II) and (III) as the first liquid crystal material, a liquid crystal compound of the general formula (IV) as the second liquid crystal material, and a third liquid crystal material. A liquid crystal compound of the general formula (V) as a liquid crystal material, and a general formula (VIII) or a general formula (VII), (V
This is achieved by blending a liquid crystal compound with III). In this case, the mixing ratio is determined by the general formulas (II), (III),
The liquid crystal compounds of (IV), (V), (VII) and (VIII) are 30% by weight, 15% by weight, 15 to 20% by weight,
15 wt%, less than 10 wt%, 20 wt%.

一般式（Ｉ）乃至（VIII）の液晶化合物を配合する場
合、一般式（Ｉ），（II），（III），（IV），
（Ｖ），（VII），及び（VIII）の液晶化合物は、それ
ぞれ、０乃至17重量％、４乃至33重量％、10乃至15重量
％、10乃至25重量％、０乃至31重量％、０乃至５重量
％、10乃至22重量％、４乃至20重量％の割合で配合され
る。望ましくは、一般式（Ｉ），（II），（III），（I
V），（Ｖ），（VII），（VIII）の液晶化合物によって
配合され、この場合の配合割合は、それぞれ０乃至17重
量％、４乃至33重量％、10乃至15重量％、10乃至25重量
％、０乃至31重量％、10乃至22重量％、４乃至20重量％
である。さらに望ましくは、一般式（Ｉ），（II），
（III），（IV），（Ｖ），（VII），（VIII）の液晶化
合物の配合割合がそれぞれ、０乃至17重量％、４乃至33
重量％、10乃至15重量％、14乃至25重量％、０乃至28重
量％、22重量％、４乃至６重量％である。When compounding the liquid crystal compounds of the general formulas (I) to (VIII), the general formulas (I), (II), (III), (IV),
The liquid crystal compounds of (V), (VII) and (VIII) are respectively 0 to 17% by weight, 4 to 33% by weight, 10 to 15% by weight, 10 to 25% by weight, 0 to 31% by weight, 0 to 31% by weight. To 5% by weight, 10 to 22% by weight, and 4 to 20% by weight. Preferably, the compounds represented by the general formulas (I), (II), (III), (I
V), (V), (VII) and (VIII) are compounded, and the compounding ratio in this case is 0 to 17% by weight, 4 to 33% by weight, 10 to 15% by weight, 10 to 25% by weight, respectively. % By weight, 0 to 31% by weight, 10 to 22% by weight, 4 to 20% by weight
It is. More preferably, general formulas (I), (II),
The compounding ratio of the liquid crystal compounds of (III), (IV), (V), (VII) and (VIII) is 0 to 17% by weight, respectively, and 4 to 33% by weight.
%, 10 to 15%, 14 to 25%, 0 to 28%, 22%, 4 to 6% by weight.

上述した本発明の液晶組成物は、第１の液晶材料中、
低粘度の一般式（II）で表わされる液晶化合物の配合割
合を多くするか、又は、第２の液晶材料の一般式（IV）
の液晶化合物及び第３の液晶材料中、一般式（Ｖ）の液
晶化合物が多量に配合され、さらに第４の液晶材料中、
屈折折率異方性Δｎの値が大きい一般式（VII）で表わ
される液晶化合物が多量に配合されている。したがっ
て、液晶組成物全体として屈折率異方性Δｎの値が大き
く、且つ低粘度の液晶化合物の配合割合が多くなり、低
粘度で且つ屈折率異方性Δｎの値が大きい。The above-mentioned liquid crystal composition of the present invention comprises:
Increase the mixing ratio of the liquid crystal compound represented by the general formula (II) having a low viscosity, or use the general formula (IV) of the second liquid crystal material.
In the liquid crystal compound and the third liquid crystal material, a large amount of the liquid crystal compound of the general formula (V) is blended.
A large amount of the liquid crystal compound represented by the general formula (VII) having a large value of the refractive index anisotropy Δn is blended. Therefore, the value of the refractive index anisotropy Δn is large and the proportion of the low-viscosity liquid crystal compound is large in the entire liquid crystal composition, and the value of the low-viscosity and refractive index anisotropy Δn is large.

（実施例）本発明の液晶組成物について、その具体的な実施例を
以下に説明する。(Examples) Specific examples of the liquid crystal composition of the present invention will be described below.

表１に本発明の第１実施例乃至第11実施例を示した。
この表１は、各一般式で表わされた液晶化合物の各実施
例ごとの配合割合を重量％で現わしたものである。この
表１中で、実施例1,2は、一般式（II），（III），（I
V），（Ｖ），（VIII）又は一般式（II），（III），
（IV），（Ｖ），（VII），（VIII）で表わされる液晶
化合物のみからなる本発明の液晶組成物を示している。
実施例3,4,6は一般式（II）で表わされる液晶化合物の
配合割合を多くして、誘電異方性Δεの値を大きくした
液晶組成物であり、実施例5,7は、一般式（IV），
（Ｖ）の液晶化合物の配合割合を多くして、誘電異方性
Δεの値を小さくした液晶組成物である。Table 1 shows the first to eleventh embodiments of the present invention.
Table 1 shows the compounding ratio of the liquid crystal compound represented by each general formula in each example in% by weight. In Table 1, Examples 1 and 2 correspond to the general formulas (II), (III), (I
V), (V), (VIII) or general formulas (II), (III),
1 shows a liquid crystal composition of the present invention comprising only liquid crystal compounds represented by (IV), (V), (VII), and (VIII).
Examples 3, 4, and 6 are liquid crystal compositions in which the blending ratio of the liquid crystal compound represented by the general formula (II) is increased to increase the value of the dielectric anisotropy Δε. Equation (IV),
This is a liquid crystal composition in which the compounding ratio of the liquid crystal compound (V) is increased to reduce the value of the dielectric anisotropy Δε.

また、本発明の液晶組成物は、誘電異方性Δεの値が
大きい実施例６の液晶組成物と、誘電異方性Δεの値が
小さい実施例７の液晶組成物とを調製し、これらの２つ
の液晶組成物内をそれぞれ所定の比率で配合することに
よって、所望の誘電異方性Δεの値を有する液晶組成物
を調製することができる。実施例8,9,10,11は、実施例
６の液晶組成物と実施例７の液晶組成物との配合比率
が、それぞれ37/63,40/60,46/54,51/49の場合を示して
おり、その配合比率に応じて異なる誘電異方性をもった
液晶組成物が得られる。The liquid crystal composition of the present invention was prepared by preparing a liquid crystal composition of Example 6 having a large value of dielectric anisotropy Δε and a liquid crystal composition of Example 7 having a small value of dielectric anisotropy Δε. By blending each of the two liquid crystal compositions at a predetermined ratio, a liquid crystal composition having a desired value of dielectric anisotropy Δε can be prepared. In Examples 8, 9, 10, and 11, the compounding ratio of the liquid crystal composition of Example 6 and the liquid crystal composition of Example 7 was 37/63, 40/60, 46/54, and 51/49, respectively. And a liquid crystal composition having a different dielectric anisotropy is obtained according to the compounding ratio.

上述した実施例１乃至11は、表１に開示した特性から
明らかな如く、Ｎ−Ｉ点が64℃以上と高く、屈折率異方
性Δｎが0.133〜0.139と大きく、粘度が27cp以下（常温
において、以下同じ）と極めて低く、また、誘電率異方
性Δεの値は、2.9〜10までの任意の値が得られる。In Examples 1 to 11 described above, as is clear from the characteristics disclosed in Table 1, the NI point is as high as 64 ° C. or more, the refractive index anisotropy Δn is as large as 0.133 to 0.139, and the viscosity is 27 cp or less (at room temperature). And the same applies hereinafter), and the value of dielectric anisotropy Δε can be any value from 2.9 to 10.

本発明の液晶組成物について、さらに具体的な実施例
を表２に示す。表２中、実施例12,13,14は、第１の液晶
材料の配合割合を多くして誘電異方性Δεの値を大きく
した液晶組成物であり、実施例15,16は、第2,第３の液
晶材料の配合割合を多くして誘電異方性Δεの値を小さ
くした液晶組成物である。表２に開示した特性から明ら
かな如く、実施例12乃至16は、Ｎ−Ｉ点が64℃以上と高
く、屈折率異方性Δｎの値が0.137〜0.139と大きく、粘
度が27cp以下と極めて低い。また誘電異方性Δεの値は
3.0乃至9.5の範囲で得られ、これらの液晶組成物を用い
た液晶表示素子をスタティック駆動したときのしきい値
電圧Vthは、2.30V乃至1.40Vであり、本発明の液晶組成
物は誘電異方性Δεの値に比べて駆動電圧を低くするこ
とができる。Table 2 shows more specific examples of the liquid crystal composition of the present invention. In Table 2, Examples 12, 13, and 14 are liquid crystal compositions in which the blending ratio of the first liquid crystal material was increased to increase the value of the dielectric anisotropy Δε. And a liquid crystal composition in which the proportion of the third liquid crystal material is increased to reduce the value of the dielectric anisotropy Δε. As is clear from the properties disclosed in Table 2, Examples 12 to 16 have extremely high NI points of 64 ° C. or higher, high values of refractive index anisotropy Δn of 0.137 to 0.139, and viscosities of 27 cp or less. Low. The value of dielectric anisotropy Δε is
The threshold voltage Vth obtained when the liquid crystal display device using these liquid crystal compositions is statically driven is 2.30 V to 1.40 V, and the liquid crystal composition of the present invention has a dielectric difference of 3.0 to 9.5. The driving voltage can be made lower than the value of the isotropic Δε.

（発明の効果）上述した様に、本発明の液晶組成物は、誘電異方性Δ
εの値がほぼ０である第３の液晶材料及び第４の液晶材
料として、屈折率異方性Δｎの値が比較的大きく、且つ
低粘度の液晶化合物を多く配合したので、液晶化合物と
しての屈折率異方性Δｎの値が大きくなり、且つ、粘度
を低下させることができた。その結果、本発明の液晶組
成物を用いた液晶表示素子は、駆動するときのしきい値
電圧が低下して消費電力が減少し、且つ、低粘度である
ため応答速度も速い。(Effect of the Invention) As described above, the liquid crystal composition of the present invention has a dielectric anisotropy Δ
As the third liquid crystal material and the fourth liquid crystal material having a value of ε of almost 0, a large amount of a liquid crystal compound having a relatively large value of refractive index anisotropy Δn and a low viscosity was blended. The value of the refractive index anisotropy Δn was increased, and the viscosity was able to be reduced. As a result, the liquid crystal display device using the liquid crystal composition of the present invention has a reduced threshold voltage when driving, which reduces power consumption, and has a low response speed due to low viscosity.

Claims

(57) [Claims]

(1) a general formula: (Where R ¹ represents an alkyl group having 2 to 3 carbon atoms,
R ² represents an alkyl group having 2 to 5 carbon atoms, and R ³ represents an alkyl group having 2 to 4 carbon atoms. Of the liquid crystal compounds represented by the formula (5)
To 75% by weight, and the general formula: (Where R ⁴ represents an alkyl group having 3 to 5 carbon atoms,
R ⁵ represents an alkyl group or an alkoxy group having 1 to 6 carbon atoms. At least one of the liquid crystal compounds represented by
10 to 50% by weight of a second liquid crystal material comprising a seed; (Where R ⁶ represents an alkyl group having 1 to 5 carbon atoms,
R ⁷ represents an alkyl group or an alkoxy group having 1 to 6 carbon atoms, R ⁸ represents an alkyl group having 2 to 7 carbon atoms,
R ⁹ represents an alkyl group or an alkoxy group having 2 to 7 carbon atoms. At least one of the liquid crystal compounds represented by
5 to 40% by weight of a third liquid crystal material comprising a seed; (Where R ¹⁰ represents an alkyl group having 3 to 5 carbon atoms, R ¹¹ represents an alkyl group having 2 carbon atoms, R ¹² represents an alkyl group having 3 carbon atoms, and R ¹³ represents an alkyl group having 3 carbon atoms. Represents an alkyl group of 4 to 5).
A liquid crystal composition comprising 45% by weight.

2. A liquid crystal material comprising: a first liquid crystal material of 19 to 60% by weight; a second liquid crystal material of 10 to 25% by weight; a third liquid crystal material of 5 to 31% by weight; 2. The liquid crystal composition according to claim 1, comprising 20 to 30% by weight.

3. The method according to claim 1, wherein the liquid crystal compound represented by the general formula I is 0 to 17
% By weight, 4 to 33% by weight of the liquid crystal compound represented by the general formula II, 10 to 15% by weight of the liquid crystal compound represented by the general formula III, and 10 to 15% by weight of the liquid crystal compound represented by the general formula IV. 25% by weight, 5 to 31% by weight of the liquid crystal compound represented by the general formula V, 10 to 22% by weight of the liquid crystal compound represented by the general formula VII, and 4% by weight of the liquid crystal compound represented by the general formula VIII. The liquid crystal composition according to claim 1, wherein the liquid crystal composition comprises: