JPH10330754A - Nematic liquid crystal composition and liquid crystal display prepared by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nematic liq. crystal compsn. which has a wide drivable temp. range and an excellent responsivity for a desired value of birefringence, and a liq. crystal display prepd. by using the same. SOLUTION: This compsn. contains a liq. crystal component A comprising at least one compd. of the formula (wherein R<11> and R<12> are each H or a 1-10C linear alkyl or alkoxy group) and a liq. crystal component B comprising a compd. having a permittivity anisotropy of +2 or higher and has a permittivity anisotropy (Δε) of 3 or higher, a nematic phase-isotropic liq. phase transition point (TN-I) of 60 deg.C or higher, and a crystalline or smectic phase-nematic phase transition point (T→I) of 0 deg.C or lower.

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 using the same.

[0002]

2. Description of the Related Art A typical liquid crystal display element is TN-L.
There is a CD (twisted nematic liquid crystal display element), clock, calculator, electronic organizer, pocket computer,
Used in word processors and personal computers. On the other hand, with the increase in the processing information of OA equipment, Scheffer et al. [SID 85 Digest, p.120
1985] and Kinukawa et al. [SID 86 Digest, p.122 1986] by STN (Super Twisted Nematic).
-LCD was developed, mobile terminal, word processor,
It has begun to spread widely to displays for high information processing such as personal computers.

Recently, an active addressing drive system [Proc. 12th IDRC p.5
03 1992] and multi-line addressing drive system [S
ID'92 Digest, p.232 1992] has been proposed. As such a liquid crystal material, the elastic constant ratio K ₃₃ / K ₁₁ is around 1.5, and the dielectric constant anisotropy and viscosity are relatively small.
In particular, those having a large birefringence are required. In addition, in order to achieve a brighter display and a higher contrast ratio, a new reflective color liquid crystal display system using the birefringence of a liquid crystal and a retardation plate instead of a color filter layer [Technical Report Vol. No.10 p.51 1990]
And a liquid crystal display device having a reflective surface with a small parabolic surface on the substrate electrode side has been proposed. As a liquid crystal material suitable for this, a birefringence index characteristic that causes a larger phase difference due to a difference in light wavelength and an optical characteristic of a birefringence index that maintains a high contrast even at a wide viewing angle are required. Further, a liquid crystal display device having a wider operating temperature is required for display applications such as miniaturization, portability, and increase in the number of pixels. As a liquid crystal material suitable for this, an elastic constant K11
Is 10. ~ 25. There is a demand for a material that is chemically stable, can efficiently reduce the response speed, and has a wider nematic temperature. Thus, there is a need for a liquid crystal material in which individual physical properties are comprehensively optimized, and a proposal for a new liquid crystal compound or liquid crystal composition is still required.

Further, due to its excellent display quality, active matrix type liquid crystal display devices have been put on the market for portable terminals, liquid crystal televisions, projectors, computers and the like. The active matrix display method uses a TFT (thin film transistor) or MI
M (metal insulator metal) or the like is used, and it is important for this method to have a high voltage holding ratio. In addition, in order to obtain a wider viewing angle characteristic, a super TFT [Asia Display95 Di
gest, p. 707 1995] by Kondo et al. (hereinafter, these active matrix display type liquid crystal display elements are collectively referred to as TFT-LCD). In order to cope with such a display element, a new liquid crystal compound or liquid crystal composition, for example, Japanese Patent Laid-Open Publication No.
No. 9, Japanese Patent Publication No. 5-501735, and the like have been proposed.

A liquid crystal display device in which liquid crystal droplets are dispersed in a polymer is known as a bright and high-contrast liquid crystal device that does not require a polarizing plate or a light distribution process. Tokushou Sho 58
No. 501631, U.S. Pat. No. 4,435,047.
In the specification, gelatin, gum arabic, polyvinyl alcohol and the like are proposed as encapsulating substances. Other than these, for example, Japanese Patent Application Laid-Open No. 61-502128, Japanese Patent Application Laid-Open No. 62-2231, and the like disclose. Have been. These have a problem that the matching between the refractive index of the liquid crystal material and the refractive index of the polymer is optimized and a voltage as high as 25 V or more is required to obtain sufficient transparency.

US Pat. No. 5,304,323, and Japanese Patent Application Laid-Open No. 1-19872 disclose techniques for enabling low-voltage driving, high contrast, and time-sharing driving required for a liquid crystal display.
Japanese Patent Application Laid-Open No. 5 (1999) -2005 discloses a liquid crystal display device having a structure in which a liquid crystal material forms a continuous layer, and a polymer substance is distributed in a three-dimensional stitch shape in the continuous layer.

As a liquid crystal material related to this purpose, for example, EP-A-359,146 discloses a method for optimizing the birefringence and dielectric anisotropy of a liquid crystal material.
No. 222320 discloses a technique for specifying the elastic constant of a liquid crystal material. Further, Japanese Patent Application Laid-Open No. 5-339573
And JP-A-6-123866 disclose a compound having a contrast of about 40 in a projection display by using a fluoro compound. However, required characteristics, high resistance value, excellent voltage holding ratio, low driving voltage, strong light scattering, high contrast ratio, fast response speed, good temperature characteristics, etc. There are problems in satisfying everything, and new proposals are still being made.

[0008]

In order to improve the liquid crystal display characteristics as described above, a liquid crystal material having a desired birefringence is required. There is also a need for higher chemical stability of the liquid crystal material, lower viscosity, high-speed response of the liquid crystal display, and a wider driving temperature range. The technology relating to the compound of the general formula (I) and the analogous compound thereof according to the present invention includes:
For example, as mentioned in JP-A-54-87688, the knowledge of a mixture containing the compound of the general formula (I) is as follows.
There have not been enough reports yet. Also, TN as described above
Liquid crystal material properties and mixtures having desired birefringence, dielectric anisotropy, elastic constant, etc. useful for -LCD, STN-LCD and light scattering type liquid crystal display have not yet been reported.

More specifically, when a liquid crystal material having a large birefringence is required, a liquid crystal material having higher chemical stability, lower viscosity, and wider nematic temperature characteristics, for example, of the following general formula: (A-1) to (a-4)

[0010]

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(Wherein R and R 'represent an alkyl group or an alkoxy group). However, problems still remain. Specifically, the compound of the general formula (a-4) has specificity in compatibility with a compound having a particularly strong polarity, and has a tendency that a smectic phase or a crystal phase easily appears. (A-
It has poor solubility with the compound of 1).

The problem to be solved by the present invention is to solve or further improve the above-mentioned problem. The driving temperature range is wide for a desired birefringence,
An object of the present invention is to provide a nematic liquid crystal composition having excellent responsiveness, and using this liquid crystal composition as a constituent material, a liquid crystal display device such as a TN-LCD, an STN-LCD, and a TFT-LCD having improved electro-optical characteristics. Is to provide.

Also, in the above-mentioned light scattering type liquid crystal display, required display characteristics such as faster response, lower voltage drivability, higher resistance of the light control layer, and higher contrast ratio are maintained and improved. Another object of the present invention is to provide a light-scattering type liquid crystal display device in which a memory phenomenon is reduced, and more uniform display of white turbidity, improved display characteristics with respect to temperature change, and response characteristics are achieved.

[0014]

The present invention has been made in order to solve the above problems. General formula (I)

[0015]

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(In the formula, R ¹¹ and R ¹² each independently represent a hydrogen atom or a linear alkyl group or alkoxy group having 1 to 10 carbon atoms.) A liquid crystal composition comprising a liquid crystal component A comprising a compound and a liquid crystal component B comprising a compound having a dielectric anisotropy of +2 or more, wherein the liquid crystal composition has a dielectric anisotropy of 3 or more. (Δε), having a nematic phase-isotropic liquid phase transition temperature (TN-I) of 60 ° C. or more, and a crystal phase or smectic phase-nematic phase transition temperature (T → I) of 0 ° C. or less.
A nematic liquid crystal composition comprising: 2. Said liquid crystal component A nematic liquid crystal composition of the 1, wherein R ¹² is characterized in that it contains 30 to 100 wt% of the compound represented by methyl, ethyl or propyl groups in the compounds of the general formula (I) Stuff. 3. 3. The nematic liquid crystal composition according to the above 1 or 2, wherein the liquid crystal composition contains the liquid crystal component A in an amount of 1 to 50% by weight. 4. The liquid crystal component B has a general formula (II-1) to (II-4)

[0017]

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(Wherein, R ^{21 to} R ²⁴ each independently represent a straight-chain alkyl group, alkenyl group having 2 to 10 carbon atoms,
represents _{s H 2s + 1 -O-C} t H 2t, s and t are each independently 1
And X ^{21 to} X ²⁴ each independently represent a fluorine atom, a chlorine atom, —OCF ₃ , —OCHF ₂ , —CF ₃ or —CN
Y ^{21 to} Y ²⁸ each independently represent a hydrogen atom or a fluorine atom, W ^{21 to} W ²⁴ each independently represent a hydrogen atom or a fluorine atom, and Z ^{21 to} Z ²³ each independently represent a single atom. Join,-
_{COO -, - C 2 H 4} -, - C 4 H 8 - represents, Z ²¹ also -C≡
C- or -CH = CH-, wherein Z ²⁴ and Z ²⁵ are each independently a single bond, -COO-, -C≡C- or -CF =
M ^{1 to} m ⁴ each independently represents an integer of 0 or 1, m ³ + m ⁴ represents an integer of 0 or 1, and the hydrogen atom (H) of the cyclohexane ring in each compound is deuterium. It may be substituted with an atom (D). 4. The nematic liquid crystal composition according to the above 1, 2 or 3, comprising a compound selected from the group consisting of compounds represented by the formula (1): 5. The liquid crystal component B is represented by the general formulas (II-1) to (II-4)
Wherein R ^{21 to} R ²⁴ are each independently an alkyl group or alkenyl group having 2 to 5 carbon atoms, and / or X ^{21 to} X ²⁴ are a fluorine atom, a chlorine atom, —OCF ₃ , or —C
5. The nematic liquid crystal composition according to the above item 4, wherein the compound is N in an amount of 10 to 100% by weight. 6. The liquid crystal component B is such that Z ²¹ and Z ²² in the compound of the general formula (II-1) are each independently a single bond, —COO—,
-C ₂ H ₄ - or -C ₄ H ₈ - a compound represented by 10 to 100
6. The nematic liquid crystal composition according to the above item 4 or 5, characterized in that the composition contains 1% by weight. 7. The liquid crystal component B contains 10 to 100% by weight of a compound represented by the general formula (II-2) wherein Z ²⁴ is a single bond, —COO— or —C≡C—. 7. The nematic liquid crystal composition according to the above 4, 5, or 6. 8. 4. The liquid crystal display device according to 4, wherein the liquid crystal component B contains at least 10% by weight of a compound represented by the formula (II-3) wherein Z ²⁵ is a single bond or a compound represented by —C≡C—.
8. The nematic liquid crystal composition according to 5, 6 or 7. 9. The liquid crystal composition described above, wherein the liquid crystal composition contains 10 to 99% by weight of the liquid crystal component B.
9. The nematic liquid crystal composition according to 5, 6, 7 or 8. 10. The liquid crystal composition has a dielectric anisotropy of -2 to 2 (Δ
a liquid crystal component C comprising a compound having ε), wherein the liquid crystal component C has a general formula (III-1) to (III-4)

[0019]

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(Wherein, R ^{31 to} R ³⁴ each independently represent a straight-chain alkyl group or alkenyl group having 2 to 7 carbon atoms, and R ^{35 to} R ³⁸ each independently represent 1 to 3 carbon atoms. 7 represents a linear alkyl group, an alkoxy group, an alkenyl group, an alkenyloxy group, or C _u H _{2u + 1} —O—C _v H _2v , and u and v
Each independently represents an integer of 1 to 5, Y ³¹ is a hydrogen atom,
Represents a fluorine atom or —CH ₃ , Y ³² and Y ³³ each independently represent a hydrogen atom or a fluorine atom, and Z ^{31 to} Z ³⁴ each independently represent a single bond, —COO—, —C ₂ H ₄ — or -C ₄ H ₈ - represents, Z ³¹ may be a -C≡C- or -CH = CH-,
Z ³⁵ represents a single bond, —C≡C—, —COO— or —CF ＝ CF—; ring A ³¹ and ring A ³² each independently represent a cyclohexane ring or a cyclohexene ring; ring A ³³ and ring A ³⁴ independently represent a cyclohexane ring or a benzene ring;
^{1 to} n ⁵ each independently represent an integer of 0 or 1, and n ⁴ + n ⁵
Is an integer of 0 or 1, and the hydrogen atom (H) of the cyclohexane ring in each compound may be substituted with a deuterium atom (D). 9. The nematic liquid crystal composition as described in 1, 2, 3, 4, 5, 6, 7, 8, or 9 above, which comprises one or more compounds selected from the group of compounds represented by (1). 11. In the liquid crystal component C, R ³¹ in the compound of the general formula (III-1) represents a linear alkyl group or alkenyl group having 2 to 5 carbon atoms, and R ³⁵ represents a linear alkyl group or alkenyl group having 1 to 5 carbon atoms. A ring-shaped alkyl group, an alkoxy group, an alkenyl group, an alkenyloxy group, a ring A ³¹ represents a cyclohexane ring, and when n ¹ is 0, a compound wherein Z ³² is a single bond or —COO—, and / or , N ¹ is 1, Z ³¹ and Z
³² to 10 to 100% by weight of the compound represented by a single bond
11. The nematic liquid crystal composition according to the above item 10, which is contained. 12. In the compound of the general formula (III-2), R ³² represents a linear alkyl group or alkenyl group having 2 to 5 carbon atoms, and R ³⁶ represents a linear chain having 1 to 5 carbon atoms. When n ² is 0, ring A ³² represents a cyclohexane ring or a cyclohexene ring, Z ³³ is a single bond, —COO— or —C ₂ H ₄ And / or when n ² is 1, ring A ³² represents a cyclohexane ring, and Z ³³ represents a single bond or a compound represented by —C ₂ H ₄ —.
12. The nematic liquid crystal composition according to the above item 10 or 11, which is contained in an amount of from 100 to 100% by weight. 13. The liquid crystal component C is a compound of the formula (III-3) wherein Z ³⁵ is represented by —C≡C—
13. The nematic liquid crystal composition according to the above item 10, 11, or 12, wherein the composition is contained in an amount of 00% by weight. 14． The liquid crystal composition contains the liquid crystal component C at most 7
The above-mentioned 10, 11, 1 characterized by containing 0% by weight.
14. The nematic liquid crystal composition according to 2 or 13. 15. The liquid crystal composition is a compound having a core structure having four six-membered rings, and one or two or more compounds having a liquid crystal phase-isotropic liquid phase transition temperature of 100 ° C. or higher. 15. The nematic liquid crystal composition as described in any one of 1 to 14 above, which comprises: 16. The liquid crystal composition has a dielectric anisotropy of 4 to 30 (Δ
ε) and the birefringence of 0.08 to 0.33 is (Δn)
A nematic phase-isotropic liquid phase transition temperature (TN-I) of 70 ° C. or more, and a crystal phase or a smectic phase-nematic phase transition temperature (T → I) of −10 ° C. or less. 16. The nematic liquid crystal composition according to any one of the above 1 to 15, wherein 17． The liquid crystal composition has an induced helical pitch of 0.5 to 1
17. The nematic liquid crystal composition according to any one of the above 1 to 16, further comprising a compound having an optically active group having a thickness of 000 μm. 18. 18. An active matrix, twisted nematic or super twisted nematic liquid crystal display device using the nematic liquid crystal composition according to the above item 17. 19. 19. The liquid crystal display device according to the above item 18, wherein the liquid crystal layer has a thickness of 1 to 30 μm. 20. 20. A light-scattering type liquid crystal display device having a dimming layer containing the liquid crystal composition according to any one of 1 to 19 and a transparent solid substance. 21. 21. The light-scattering liquid crystal according to the above 20, wherein the liquid crystal composition forms a continuous layer in the light modulating layer, and the transparent solid substance forms a uniform three-dimensional network structure in the continuous layer. Display device. 22. 22. The light scattering type liquid crystal display device according to the above item 20 or 21, wherein the transparent solid substance is formed from a polymerizable composition containing a polymer-forming bifunctional monomer and a monofunctional monomer. Was found as a means for solving the above-mentioned problem.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal composition of the present invention contains a liquid crystal component A composed of a compound represented by the general formula (I) as an essential component. The liquid crystal component A has a lower viscosity, a higher birefringence, and a higher elastic constant. For this reason, the liquid crystal composition of the present invention can adjust the birefringence and the elastic constant in a wide range, and has a feature that it can be driven, for example, at a high speed. The liquid crystal composition of the present invention contains 1 to 50% by weight of a liquid crystal component A composed of a compound of the general formula (I), and 10 to 99% by weight of a liquid crystal component B composed of a compound having a dielectric anisotropy of +2 or more. %, It was found to have faster response characteristics. In addition, the liquid crystal component A improves the nematic phase-isotropic liquid phase transition temperature to a relatively high temperature when mixed with other liquid crystal materials in addition to the above, and has excellent compatibility. The temperature range can be made wider. Furthermore, the dielectric anisotropy is in the range of -2 to +2, and has higher chemical stability.

From such a viewpoint, a more preferred form of the compound represented by the general formula (I) is a compound wherein R ¹² is a methyl group, an ethyl group or a propyl group,
More specifically, general formulas (I-1) to (I-5)

[0023]

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Compounds represented by the following formulas are preferred.
Has at least one of the above compounds in an amount of 30 to 10
A nematic liquid crystal composition containing 0% by weight is preferred.
In addition, each of the above compounds was used after removing impurities by a method such as distillation, column purification, recrystallization, etc. and sufficiently purified.

One or more compounds of the general formula (I) can be contained as the liquid crystal component A, but the effect described above can be obtained even with one compound. The liquid crystal composition of the present invention containing the liquid crystal component A containing at least one kind of the compound represented by the general formula (I) has a TN
-To make liquid crystal display devices such as LCD, STN-LCD, TFT-LCD and the like more improved electro-optical characteristics, and particularly to make the response at low temperature and the temperature dependence of steep drive voltage more preferable.

The liquid crystal composition of the present invention comprises, in addition to the liquid crystal component A, one or more compounds having a dielectric anisotropy of +2 or more.
It contains a liquid crystal component B containing more than one kind. The liquid crystal compound having a dielectric anisotropy larger than 2 described in the present invention has the following significance. The chemical structure of the liquid crystal compound is rod-shaped, and has a core structure in which the central portion has one to four six-membered rings. A terminal group substituted at a position corresponding to the direction, and at least one of the terminal groups present at both ends is a polar group, that is, for example, -CN, -OCN, -NC
S ,, - F, -Cl, -NO 2, -CF 3, -OCF 3, -OCHF
₂ is a compound. As a result, the optical anisotropy of the liquid crystal layer can be set to a predetermined value, can be electrically driven, and the operating temperature range can be widened.

As the liquid crystal component B, at least one compound having a dielectric anisotropy of +2 or more is required.
Five ranges are preferred. Further, the dielectric anisotropy is +8 to +
It is preferable to appropriately select from among the compounds of 13, the compounds of +14 to +18, and the compounds of +18 or more, so that a predetermined driving voltage and response characteristics can be obtained. in this case,
It is preferable to mix at most 10 or less compounds having a dielectric anisotropy of +8 to +13, and +14 to +18.
The compounds having a dielectric anisotropy of at least 8 are preferably mixed in a range of at most 8 or less, and the compounds having a dielectric anisotropy of +18 or more are preferably mixed within a range of at most 10 or less. Use of the liquid crystal component B as described above gives a more favorable effect to the temperature characteristics of the display characteristics. More specifically, it is preferable that the temperature dependency such as the driving voltage, the contrast relating to the steepness, and the response is more preferable.

The liquid crystal component B of the present invention has the general formula (II-
It is preferable to contain 10 to 100% by weight of a compound selected from the compounds represented by 1) to (II-4). A more preferred form of the compounds represented by the general formulas (II-1) to (II-4) is a compound wherein R ^{21 to} R ²⁴ are represented by an alkyl group or an alkenyl group having 2 to 7 carbon atoms and / or X ^{21 to} X
²⁴ F, Cl, -OCF _3, or by selecting the compound represented by -CN, preferably contains at least one kind. Further, in the general formula (II-2), Z ²⁴ is a single bond, a compound represented by —COO— or —C≡C—, and in the general formula (II-3), Z ²⁵ is represented by —C≡C—. It is preferable to contain a compound. Particularly preferred and more specific compounds represented by formulas (II-1) to (II-4) include compounds represented by formulas (II-1a) to (II-
4d)

[0029]

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[0030]

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[0031]

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[0032]

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(Wherein, R ^{21 to} R ²⁴ , X ^{21 to} X ²⁴ , Y ²¹ to
Y ²⁸ , Z ^{21 to} Z ²⁵ and W ^{21 to} W ²³ represent the same meaning as described above. ). In addition, each compound was used after removing impurities by a method such as distillation, column purification, recrystallization, etc. and sufficiently purified. The liquid crystal component B containing these compounds has a feature of being well mixed with the liquid crystal component A, which is an essential component, and is particularly useful for adjusting the drive voltage according to the purpose and improving its temperature dependence or response. is there. In particular, the general formulas (II-1a) to (II-1h) and the general formulas (II-2a) to (II-4)
The compound d) is excellent in this effect, and this effect can be obtained even with a small content of 1 to 25%.

Further preferred embodiments will be described in detail. In the following description, -F represents a fluorine atom, -Cl
Represents a chlorine atom, and -H represents a hydrogen atom.

[0035] R ²¹ is compounds alkenyl group of the alkyl group or CH ₂ = CH- 2-5 carbon atoms _{(CH 2) p (p =} 0,2) are preferred, the general formula (II-1a) , (II-1d) preferably have this group, and when the liquid crystal component B contains at least one compound having an alkenyl group, the viscosity and viscoelasticity can be reduced. Similarly, R ^{22 is} also preferably a compound having an alkyl group having 2 to 5 carbon atoms or an alkenyl group described above,
-2a), (II-2d), (II-2f) and (II-2g) preferably have this group. X ^{21 to} X ²⁴ are F, Cl,
It is preferable to frequently use a compound of —OCF ₃ and —CN. When high-speed response is important, X ^{21 to} X ²⁴ are F and —OCF _3.
The general formulas (II-1a), (II-1d), (II-2a), (II-
It is preferable that the compounds of 2c), (II-2d), (II-2g), and (II-3a) are frequently used in the liquid crystal component B. When a larger birefringence is required, X ^{22 to} X ²⁴ are preferably used. Cl, -OCF _3, -C
It is preferable to frequently use the compounds of the general formulas (II-2a) to (II-4d) which are N for the liquid crystal component B. When a lower driving voltage is required, X ²¹ is -CN and Y ²¹ is H or F A compound of the general formulas (II-1a) to (II-1g), wherein X ²² is F, Cl,-
General formulas (II-2a) to (II-2) in which Y ²³ is H or F in CN
Compounds of f), X ²³ is F, Cl, compounds of general formula Y ²⁵ is F at -CN (II-3a) ~ ( II-3c), X 24 is F, C
l, -CN and general formulas (II-4a) to (II-4) wherein Y ²⁷ is F
It is preferred that the compound of d) is frequently used in the liquid crystal component B.
In particular, active matrix display, TFT-LCD, MIM
-Light scattering type liquid crystal display devices having a super TFT or active matrix technology combined with LCD and IPS mode (for example, display devices having a light control layer containing a liquid crystal material and a transparent solid substance) are X ²¹ It is preferable to frequently use a compound in which -X ²⁴ is -F.

In general formulas (II-1) to (II-4),
When responsiveness is important Y^{twenty one}~ Y²⁸Is H and / or W^{twenty one}
~ W^{twenty four}Can be used in many cases,
Y to improve temperature dependence of pressure^{twenty one}~ Y²⁸Is F, W^{twenty one}
~ W^{twenty four}Is F, particularly preferably Y^{twenty one}, Y^{twenty three}, Y
^{twenty five}, Y²⁷, W^{twenty one}~ W^{twenty four}Frequently use compounds in which is F
Is preferable, in which W^{twenty one}And W^{twenty two}If F is Y^{twenty four}
Can be further improved by selecting a compound in which
W for general formula (II-3)^{twenty three}And / or W^{twenty four}Is F
The compatibility can be further improved by selecting a compound. General formula
In (II-1), Z^{twenty one}And Z^{twenty two}One is a single bond compound
Is preferable, in order to improve the responsiveness and compatibility at low temperatures,
Single bond compound and -COO-, -C_TwoH_Four-, -C_FourH₈-Compound
It is preferable to use a liquid crystal component B in which a substance is used in combination. Bifold
If a higher folding ratio is required, the general formula (II
-2), Z in (II-3)^{twenty four}, Z^{twenty five}Is a compound of -C≡C-
And / or X in general formula (II-4)^{twenty four}Becomes CN
It is preferable that the compound is frequently used for the liquid crystal component B. General formula
M in (II-1), (II-2) and (II-4)¹~ M^FourIs 0
Compound and m in general formulas (II-1) and (II-2)¹, M^Two
Is a compound of the formula (II-4)^Three+ M^FourIs 1
Liquid crystal component with compound and / or compound of general formula (II-3)
The mixing ratio of B is in the range of 0 to 100 to 100 to 0.
When can choose, higher nematic phase-isotropic liquid
When a phase transition temperature is required, the general formulas (II-1) and (II-
M in 2)¹, M^TwoIs a compound of the formula (II-3)
M in the compound and / or general formula (II-4)^Three+ M^FourIs 1
It is preferable to frequently use the compound of formula (1). General formula (II-1),
The hydrogen atom in the cyclohexane ring of (II-2) is a deuterium atom
Can be used, but this compound
The material is adjusted according to the elastic constant of the liquid crystal composition, and the size of the alignment film is adjusted.
It is useful for adjusting the retilt angle.
To contain at least one or more substituted compounds
Is preferred. The effect of the liquid crystal component B described above will be described later.
Even when the content of the liquid crystal component C is very small.
Can be For the purpose of lowering the drive voltage
In addition, the content of the liquid crystal component C is set to 10% by weight or less.
it can. In this case, the viscosity of the liquid crystal component C is made as low as possible.
Preferably, there is almost no increase in drive voltage
Only within a small range, and the response speed is improved efficiently.
It is. For example, when the liquid crystal component C is small, this effect is
As a method for achieving this by using the crystal component B, general formulas (II-1) to
In (II-4), X^{twenty one}~ X^{twenty four}Is F, Cl, -OCF_Threeso
A compound or Y ^{twenty one}~ Y^{twenty four}Wherein Z is F or Z^{twenty four},
Z^{twenty five}Is -COO-, -C≡C-, or m¹Is 1
Any compound of a certain compound is contained in the liquid crystal component B.
Is preferred. In particular, the general formulas (II-1) to (II-4)
And X^{twenty one}~ X^{twenty four}Is F, Cl, -OCF_Three, -CN, and / or
Or Y^{twenty one}~ Y^{twenty three}Is preferably F.

The liquid crystal composition of the present invention comprises, in addition to the liquid crystal component A and the liquid crystal component B which are essential components, a liquid crystal component C comprising a compound having a dielectric anisotropy of -2 to 2 at most 70%.
It is preferred that the content be contained by weight. -2 described in the present invention
Preferred examples of the liquid crystal compound having a dielectric anisotropy of 1 to 2 are shown below. That is, the chemical structure of the liquid crystal compound is rod-shaped, the central portion has a core structure having one to four six-membered rings, and the six-membered rings located at both ends in the long axis direction of the central portion are formed of liquid crystal molecules. It has a terminal group substituted at a position corresponding to the major axis direction, and both terminal groups present at both ends are non-polar groups, that is, for example, an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkenyl group, an alkenyloxy group. And alkanoyloxy groups. The liquid crystal component C is preferably composed of at least one type and at most 20 types, and more preferably at least two types and at most 12 types.

The liquid crystal component C of the present invention has the general formula (III-
It is preferable to contain 10 to 100% by weight of a compound selected from the compounds represented by 1) to (III-4). Particularly preferred compounds represented by formulas (III-1) to (III-4) include compounds represented by formulas (III-1a) to (III-4e)

[0039]

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[0040]

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[0041]

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(Wherein, R ^{31 to} R ³⁸ and Y ^{31 to} Y ³³ have the same meanings as described above). The liquid crystal component C containing these compounds has a characteristic of being mixed well with the liquid crystal component A containing the compound of the general formula (I), and is useful for improving a low temperature nematic phase.

As the liquid crystal component C, general formulas (III-1) to (I
Reduces viscosity and viscoelasticity by containing compound of II-4)
If the specific resistance and voltage holding ratio are relatively high,
It has the feature of. The viscosity of the liquid crystal component C is as low as possible.
It is preferable that the viscosity is 45 cp in the present invention.
Or less, more preferably 30 cp or less, and 20 c
p or less is more preferable, and 15 cp or less is particularly preferable.
The liquid crystal component C is represented by the general formulas (III-1) to (III-4)
Preferred compounds have the general formulas (III-1a) to (III-3a):
(III-3c)-(III-3g), (III-4a), (III-4d)-
(III-4e). Also, R³¹~ R³⁴Has 2 to 2 carbon atoms
5 linear alkyl group or CH_Two= CH- (CH _Two)_q(q =
0 or 2) at least one compound which is an alkenyl group
The liquid crystal component C contained above has a more favorable effect.
You. More particularly, general formulas (III-1a), (III-1d), (III-
Compound of 2a), Y³¹Is a hydrogen atom, a general formula (III-3c)
To (III-3f) and / or R³⁸Is an alkyl group
The compound of general formula (III-4a) contains a small amount of 3 to 30%
This effect can be obtained even if
It is useful, for example, for STN-LCD.

Due to the above-mentioned effects, the liquid crystal component C is contained.
More preferred compounds to be used are compounds of the general formula (III-1)
In a product, R³¹Is a linear alkyl having 2 to 5 carbon atoms
R or alkenyl group;³⁵Has 1 to 4 carbon atoms
Linear alkyl group, alkoxy group, alkenyl group,
A alkenyloxy group, a ring A³¹Has a cyclohexane ring
Represents n¹Is 0, Z³²Is a single bond or -COO-
, N¹If is 1, Z ³¹, Z³²Is represented by a single bond
In the compound of the general formula (III-2), R³²
Is a linear alkyl group or alkenyl having 2 to 5 carbon atoms
R represents a group³⁶Is a linear alkyl having 1 to 4 carbon atoms
Group, alkoxy group, alkenyl group, alkenyloxy group
And n^TwoIs 0, ring A³²Is cyclohexane ring
Is a cyclohexene ring; Z³³Is a single bond, -COO- or
Is -C_TwoH_Four-N^TwoIs 1, the ring A³²Is cyclohex
Is a sun ring, Z³³Is a single bond or -C_TwoH_Four-Represented by
It is a compound.

The liquid crystal component C of the present invention has the general formula (III-
1), general formula (III-2), general formula (III-3), general formula (III
-4), the compound represented by the general formula (III-1) and / or (III-2) and the compound represented by the general formula (III-3) and / or By using a compound represented by the general formula (III-4), in particular, a compound in which Z ³⁵ is represented by —C≡C—, the birefringence of the liquid crystal composition can be easily optimized according to the intended use. Can be. General formula (III-
1) a compound of the general formula (III-2), for example, a compound of the general formula (III-1)
a) The birefringence can be reduced by frequently using the compounds of (III-2f), and it is possible to easily achieve a reduction in color unevenness, an improvement in viewing angle characteristics, and an increase in contrast ratio of a liquid crystal display device. Can be. Also, a compound of the general formula (III-3), for example, a compound of the general formulas (III-3a) to (III-3h), or a compound of the general formula (III-4), for example, the general formula (III-4)
By frequently using the compounds a) to (III-4e), the birefringence can be increased, and a thin liquid crystal display element having a liquid crystal layer of 1 to 5 μm can be manufactured.

When the liquid crystal composition of the present invention is intended to have a quicker response to the magnitude of the driving voltage, the following can be achieved. When a medium drive voltage is intended, the liquid crystal composition of the present invention has a dielectric anisotropy in the range of 3 to 15 and a viscosity at 20 ° C. of 8 to 20 c. p. Is preferably within the range. In this case, the viscosity of only the liquid crystal component C is 25c. p. The following is preferred, and 15c. p. The following is more preferable, and 10c. p. The following are particularly preferred.
When a particularly low driving voltage is intended, the dielectric anisotropy of the liquid crystal composition of the present invention is preferably in the range of 15 to 30, and particularly preferably in the range of 18 to 28.

At present, a polyimide-based alignment film used for TN-LCD, STN-LCD or TFT-LCD is frequently used. For example, LX1400, SE150, SE610, AL1051, AL34
08 etc. are used. The liquid crystal display characteristics, display quality, reliability, and productivity are closely related to the specification of the alignment film. For example, the pretilt angle characteristics are important for the liquid crystal material. The magnitude of the pretilt angle needs to be adjusted appropriately in order to obtain desired liquid crystal display characteristics and uniform orientation. For example, when the pretilt angle is large, an unstable alignment state is likely to occur, and when the angle is small, sufficient display characteristics are not satisfied.

The present inventors have found that a liquid crystal material having a larger pretilt angle and a liquid crystal material having a smaller pretilt angle are selected, and by applying this, desired liquid crystal display characteristics and uniform orientation can be obtained. We have found what we can achieve from the materials. This technique can be applied to the present invention. For example, when the liquid crystal component B contains the general formulas (II-1) to (II-4), the result is as follows. The larger pretilt angle is such that R ²¹ is an alkenyl group, X ²¹ is F, Cl, —CN, Y
²¹ , a compound in which Y ²² is F and / or R ²¹ is an alkyl group;
²¹ F, Cl, -CN, Z ²² is _{-C 2 H 4 -, - C} 4 H 8 - obtained by causing a large amount of content of the compound, a smaller pretilt angle, R ²¹ is an alkenyl group, _{C s H 2s +1 -O-C} t H
_2t , can be obtained by increasing the content of a compound in which X ²¹ is F, Y ²¹ is F, and Y ²² is H and / or a compound in which Z ²² is —COO—. In the case of a compound in which the hydrogen atom of the cyclohexane ring in the general formulas (II-1) and (II-2) is replaced with a deuterium atom,
Depending on the replacement position, it allows a wide adjustment of the pretilt angle. Such an effect can be almost obtained, for example, when a larger pretilt angle is obtained, by including the above compound in an amount of 10 to 40% by weight or more based on the total amount of the liquid crystal composition.

The technology relating to the compound of the general formula (I) according to the present invention is described in, for example, JP-A-54-87688. For example, a mixture containing the compound of the general formula (a-3) is disclosed. Have been. In addition, the general formulas (a-1) and (a
The compound of -2) is further mixed to make it useful for compatibility and response characteristics. However, when the compound represented by the general formula (a-3) was excluded from the composition disclosed in JP-A-54-87688, the composition was poorly soluble, and an improvement was required. Regarding the response characteristics, for example, the response characteristic of a TN-LCD is 60%.
msec or less, preferably 50 msec or less, more preferably 4 msec or less.
0 msec or less, particularly preferably 30 msec or less is currently required and needs improvement. In particular, the general formula (a-
The compound of 3) tends to deteriorate the response characteristics, and thus requires a new means for improvement.

The present invention has solved the above-mentioned problems, and more specifically, has been achieved, for example, by finding the following measures. (1) The content of the liquid crystal component A is not excessively used, and is 50% by weight or less. (2) When the content of the liquid crystal component A is particularly large, the number of compounds constituting the liquid crystal component B is four or more. (3) The liquid crystal component B contains at least one compound having a cyclohexane ring. In this case, the compound of the general formula (II-1) showed more preferable results. (4) When the compounds of the general formulas (II-2) and (II-3) were used, it was particularly preferable to use the compound of the general formula (II-1) in combination. (5) When the compound constituting the liquid crystal component C is particularly high in the content of the liquid crystal component A,
To contain. (6) The liquid crystal component B is represented by the general formula (II-2),
When the compound of (II-3) was contained, it was found that it was preferable to use the liquid crystal component C in combination even in a trace amount. In this case, the compounds of the general formulas (III-1) to (III-3) showed more preferable results.

The content of each liquid crystal component in the nematic liquid crystal composition of the present invention can be as follows. Liquid crystal component A
Is in the range of 1 to 50% by weight, preferably in the range of 3 to 40% by weight, and more preferably in the range of 3 to 30% by weight. The liquid crystal component B is in the range of 10 to 99% by weight,
A range of 25 to 90% by weight is preferred, and 25 to 80% by weight.
Is more preferable. The content of the liquid crystal component C is at most 70% by weight, preferably 3 to 65% by weight, more preferably 5 to 60% by weight, and more preferably 10 to 55% by weight.
The range of weight% is more preferred. The content of the compound represented by the general formula (I) is preferably 20% by weight or less alone,
It is preferable to use two or more of them, and the content of the compounds represented by formulas (I-1) to (I-5) with respect to the liquid crystal component A is in the range of 50 to 100% by weight. , 70
The range is preferably from 100 to 100% by weight. General formula (II-1)
Compound represented by (II-4) or general formula (II-1a):
The content of the compound represented by (II-4d) is preferably 30% by weight or less, more preferably 25% by weight or less, as a single substance.
More than that, it is preferable to constitute two or more kinds. The content of the liquid crystal component B is in the range of 10 to 100% by weight, preferably 50 to 100% by weight, and 75 to 1% by weight.
A range of 00% by weight is more preferred. General formula (III-1)
The compound represented by (III-4) or the general formula (III-1a)
The content of the compound represented by the formula (III-4e) is 30
% By weight or less, more preferably 25% by weight or less, and more preferably 2 or more kinds. The content of the liquid crystal component C is in the range of 10 to 100% by weight, but 50 to 100% by weight. %, Preferably 75%
The range of -100% by weight is more preferable.

The crystalline phase or the smectic phase-nematic phase transition temperature is preferably -10 ° C or lower, more preferably -20 ° C or lower, and particularly preferably -30 ° C or lower. The nematic phase-isotropic liquid phase transition temperature is 60 ° C. or higher, preferably 70 ° C. or higher, and more preferably 80 ° C. to 130 ° C.
Range. The liquid crystal composition of the present invention requires a dielectric anisotropy of 3 or more, preferably in the range of 4 to 40, and in the case of emphasizing high-speed response, the range of 4 to 16 requires a lower driving voltage. If so, the range of 17 to 30 is preferable.
The smaller or medium birefringence is between 0.09 and 0.1
8 is preferred and the larger birefringence is 0.18.
The range of -0.33 is preferable. Such properties of the nematic liquid crystal composition are useful for use in an active matrix type, twisted nematic or super twisted nematic liquid crystal display device.

The nematic liquid crystal composition is useful for TN-LCDs and STN-LCDs having a high response speed, and can provide a color display by the birefringence between the liquid crystal layer and the retardation plate without using a color filter layer. The present invention is useful for a liquid crystal display device which can be used, and a transmissive or reflective liquid crystal display device can be used. This liquid crystal display element has a substrate having a transparent electrode layer and at least one of which is transparent, and the molecules of the nematic liquid crystal composition are twisted between the substrates. °, preferably from 90 ° to 270 °, preferably from 45 ° to 135 ° or from 180 ° to 26 °.
It is particularly preferred to select in the range of 0 °. For this,
The liquid crystal composition of the present invention has an induced helical pitch of 0.5 to 10
A compound having an optically active group having a thickness of 00 μm can be contained. The pretilt angle obtained by the alignment film provided on the transparent electrode substrate is preferably selected in the range of 1 ° to 20 °, and the twist angle is preferably 30 ° to 100 °, and the pretilt angle of 1 ° to 4 ° is preferable. 100 ° -1
At 80 °, a pretilt angle of 2 ° to 6 ° is preferable.
For 0 ° to 260 °, a pretilt angle of 3 ° to 12 ° is preferable, and for 260 ° to 360 °, a pretilt angle of 6 ° to 20 ° is preferable.

The liquid crystal composition of the present invention has the general formula (I-
1) In addition to the compounds represented by (III-4), in order to improve the characteristics of the liquid crystal composition, the liquid crystal composition contains a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, and the like which are recognized as a liquid crystal compound. Is also good. However, if these compounds are used in a large amount, the properties of the nematic liquid crystal composition will be reduced. Therefore, the amount added is limited according to the required properties of the obtained nematic liquid crystal composition.

The present inventors have found that since the liquid crystal composition has a large birefringence, at least one of the transparent electrode layers has a dimming layer sandwiched between two transparent substrates, It has been found that the light modulating layer is also useful for providing a light contrast type liquid crystal display containing a liquid crystal material and a transparent solid substance to provide high contrast due to advantageous light scattering characteristics.

A liquid crystal material having a large birefringence is usually
Often, an induced crystalline phase or a partially crystallized smectic phase develops, conversely, the liquid crystal phase becomes narrower, or exhibits a liquid crystal phase with a large birefringence and a wide temperature. It has not been possible to achieve a particularly high voltage holding ratio, which is essential for the method. Furthermore, when a light-scattering type liquid crystal display was produced, the light transmittance T0 when no voltage was applied was switched from the voltage applied state to the non-applied state compared to the value immediately after fabrication or the value left for a long time after voltage application. A memory phenomenon in which the value immediately after becomes larger appears, and as a result, the contrast of the liquid crystal display is deteriorated, and the use of a fluorotoluene-based compound does not always lead to a favorable result. . The liquid crystal composition of the present invention avoids or reduces such a problem.

Further, it has been found that the liquid crystal composition of the present invention is a liquid crystal material exhibiting high compatibility with a polymer-forming compound for forming a transparent solid substance. The transparent solid substance is preferably formed by polymerizing a polymer-forming compound, for example, a light control layer obtained by mixing a UV-curable resin composition containing a compound having a UV-curable vinyl group with a liquid crystal material. After sandwiching the forming material between two substrates, the ultraviolet-curable resin composition is cured to produce the resin composition. When the compatibility between the polymer-forming compound and the liquid crystal material is higher, it is possible to obtain a more uniform solution in a wider temperature range. When the polymer-forming compound is cured in such a state, a light-modulating layer having a light scattering property can be produced with no or little deviation, and display characteristics without unevenness in driving voltage and contrast ratio. And a light-scattering type liquid crystal display achieving more uniform display of white turbidity can be provided. Therefore, a liquid crystal material suitable for producing a liquid crystal display exhibiting more uniform light scattering characteristics or a relatively large liquid crystal display by using a vacuum injection method or the like has been found.

As the liquid crystal material, a liquid crystal compound having no cyano group is preferably used in order to obtain a high voltage holding ratio or a large birefringence of 0.200 or more required in the active matrix system. As the liquid crystal compound to be used, an azine compound represented by the general formula (I) is preferable, and it is preferable to combine with a fluorotolan compound represented by the general formulas (II-2) and (II-3). 3
More preferably, a fluorotolan compound having two rings is used as an essential component. By containing the azine-based compound represented by the general formula (I), it is possible to provide a light-scattering liquid crystal display device which has an effect of improving responsiveness and is useful for displaying moving images. Also, to prepare a liquid crystal display having a higher voltage holding ratio, it is preferable to use a higher specific resistance liquid crystal material, the specific resistance 10 ¹¹
It is preferably Ω · cm or more, more preferably 10 ¹² Ω · cm or more, and most preferably 10 ¹³ Ω · cm or more.

The present inventors have disclosed in Japanese Patent Application Laid-Open No. 6-222320 that the relationship between the physical properties of a liquid crystal material and the display characteristics of a liquid crystal display is represented by the following equation (IV).

[0060]

(Equation 1)

Vth represents a threshold voltage, ¹ Kii,
² Kii represents an elastic constant, ii represents 11, 22, or 33, and △ ε
Represents the dielectric anisotropy, <r> represents the average gap distance at the interface of the transparent solid substance, A represents the anchoring energy of the transparent solid substance with respect to the liquid crystal molecules, and d represents the distance between the substrates having the transparent electrodes. Represents the distance of

This equation means that the regulating force exerted on the liquid crystal molecules by the transparent solid interface changes depending on the ratio between the elastic constant ¹ Kii and the anchoring energy A. In particular, the effect is smaller than the actual average gap distance <r>, which substantially increases the driving voltage by ¹ Kii / A, thereby effectively reducing the driving voltage. This relationship can be applied to the present invention, and by selecting the dielectric anisotropy and the elastic constant of the liquid crystal material depending on the liquid crystal compound constituting the liquid crystal material, a more preferable liquid crystal display driven at a low voltage is obtained. Is what you can do. More specifically,
The following is preferred. By forming the transparent solid substance from a polymerizable composition containing a bifunctional monomer and a monofunctional monomer as a polymer-forming compound, better display characteristics of a liquid crystal display can be obtained. By using a composition in which a bifunctional monomer and a monofunctional monomer are combined as the polymer-forming compound, the shape of the transparent solid material becomes more uniform in the process of forming the transparent solid material from the polymer-forming compound. It is thought that the structure of the liquid crystal material can be controlled and the properties of the interface with the liquid crystal material can be manipulated. More specifically, the average air gap <r> and the anchoring energy A in Equation (IV) can be made superior. In this way, the driving voltage can be reduced while maintaining the cloudiness and transparency. Furthermore, for example,
The liquid crystal material containing the compound represented by the above general formula (I) eliminates the memory phenomenon by using a polymerizable composition in which a bifunctional monomer and a monofunctional monomer are used in combination as a polymer-forming compound. Alternatively, it can be reduced.

The liquid crystal material used in the present invention is also useful for display in which liquid crystal droplets obtained by microencapsulating a liquid crystal material between two substrates having a transparent electrode layer are dispersed in a transparent solid substance. Is expected. The transparent solid substance formed between the substrates may be in the form of fibers or particles, or may be in the form of a film in which liquid crystal materials are dispersed in the form of droplets, but those having a three-dimensional network structure may be used. More preferred. Further, the liquid crystal material preferably forms a continuous layer, but is important for forming an optical boundary surface by forming a disordered state of the liquid crystal material and for exhibiting light scattering. The average diameter of the shape of the three-dimensional network structure formed from such a transparent solid material is too large or too small compared to the wavelength of light. The range is preferably from 2 to 2 μm. Further, the thickness of the light control layer is preferably in the range of 2 to 30 μm, and particularly preferably in the range of 5 to 20 μm, depending on the purpose of use.

In the liquid crystal display of the present invention thus manufactured, the present inventors have conducted intensive studies on the liquid crystal material and the transparent solid substance constituting the liquid crystal display utilizing the light scattering opaque state and the transparent state. The liquid crystal compound constituting the material, compatibility with the polymer-forming compound and finding a preferable configuration of the polymerizable composition, faster response, lower voltage drivability, higher light control layer resistance, Alternatively, while maintaining and improving display characteristics such as a higher contrast ratio, the memory phenomenon is reduced, and a more uniform display of white turbidity is achieved, thereby having characteristics required for an active matrix system. The liquid crystal display of the present invention can be used, for example, as a projection display device or a direct-view portable terminal display (Personal Digital Assistance).

[0065]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Further, “%” in the compositions of the following examples means “% by weight”.

The chemical stability of the composition was as follows: liquid crystal composition 2 g
Was placed in an ampoule tube, vacuum-degassed, sealed with nitrogen replacement, and subjected to a heating promotion test at 150 ° C. for 1 hour to measure the specific resistance or voltage holding ratio of this liquid crystal composition.
The characteristics measured in the examples are as follows.

TN-I: Nematic phase-isotropic liquid phase transition temperature (° C.) T → N: Solid phase or smectic phase-nematic phase transition temperature (° C.) Vth: When a TN-LCD having a cell thickness of 6 μm is formed. Γ: ratio of saturation voltage (Vsat) to Vth Δε: dielectric anisotropy Δn: birefringence η: viscosity at 20 ° C. (cp) (Example 1) Nematic liquid crystal composition (2-1)

[0068]

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Was prepared, and various properties of the composition were measured. The results were as follows. TN-I: 93.6 ° C. T → N: −1. C Vth: 2.59 Vγ: 1.15 Δε: 4.9 Δn: 0.281 Using this nematic liquid crystal composition, the cell thickness d was 1.8.
When a TN-LCD of μm was constructed and its display characteristics were measured, the threshold voltage was 2.28 V and the response speed was 1.1 ms.
ec was obtained.

When the wavelength dispersion of the birefringence of this nematic liquid crystal composition was measured, the ratio at 400 nm to the light wavelength of 650 nm was 1.15 or more. Because this liquid crystal material shows a larger phase difference due to the difference in the wavelength of light, a new reflective color that uses the birefringence of the liquid crystal and the phase difference plate to perform color display without using a color filter layer This is useful for a liquid crystal display system.

A chiral substance “S-811” (manufactured by Merck) was added to the nematic liquid crystal composition to prepare a mixed liquid crystal. On the other hand, "San Ever
An alignment film was formed by rubbing an organic film of "610" (manufactured by Nissan Chemical Industries, Ltd.) to produce an STN-LCD display cell having a twist angle of 220 degrees. The mixed liquid crystal was injected into this cell to construct a liquid crystal display, and the display characteristics were measured. As a result, a liquid crystal display device exhibiting STN-LCD display characteristics with excellent high time division characteristics and improved fast response was obtained. In addition, the chiral substance is the intrinsic helical pitch P of the mixed liquid crystal by adding the chiral substance.
And the cell thickness d of the display cell is Δn · d = 0.85, d /
It was added so that P = 0.53. (Example 2) Nematic liquid crystal composition (2-2)

[0072]

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Was prepared, and various properties of the composition were measured. The results were as follows. TN-I: 115.6 ° C. T → N: −8. ° C Vth: 2.70 Vγ: 1.13 Δε: 3.9 Δn: 0.143 η: 23.1 c. p. Specific resistance before test: 6.0 × 10 ¹¹ Ω · cm Specific resistance after heating promotion test: 6.3 × 10 ¹¹ Ω · cm Voltage holding ratio before test: 98.4% Voltage holding ratio after heating promotion test : 98.0% This nematic liquid crystal composition is described in the literature “High-speed liquid crystal technology”.
(P. 63, published by CMC Co., Ltd.), which shows a value close to the limit value of 1.12 which is the limit value of the optical steepness of the liquid crystal display. It can be understood that it is useful for driving.

Since the nematic liquid crystal composition has a high specific resistance and a high voltage holding ratio after the heating acceleration test, it can be understood that the composition is thermally stable. Further, a new nematic liquid crystal composition of the present invention using this composition as a basic constituent material was prepared, and an active matrix liquid crystal display device using the same was prepared. Was confirmed. Furthermore, in the same manner, another nematic liquid crystal composition of the present invention using this composition as a basic constituent material was prepared, and a twisted nematic and a super twisted nematic liquid crystal display device were prepared. It was confirmed that the product was excellent without flicker.

The above nematic liquid crystal composition (2-2) is composed of a base liquid crystal (b-1)

[0076]

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And a mixture of the formula (I). Various characteristics of the base liquid crystal (b-1) were measured. The results were as follows. TN-I: 116.7 ° C. T → N: +11. ° C Vth: 2.14 Vγ: 1.23 Δε: 4.8 Δn: 0.090 η: 19.8 c. p. Comparing the characteristics, the liquid crystal composition of the present invention had a more preferable result because the birefringence was larger, the temperature range of the nematic phase was wider, and the ratio between the saturation voltage and the threshold voltage was smaller. However, the compound of the general formula (I) has a higher viscosity and tends to increase the viscosity of the base liquid crystal (b-1).

Despite the viscous properties described above, surprisingly useful facts have been found. That is, when the response characteristics of the liquid crystal composition (2-2) of the present invention and the base liquid crystal (b-1) were measured and compared, it was 25.3 msec for the base liquid crystal (b-1).
In the liquid crystal composition (2-2) of the present invention, a more preferable result was 21.3 msec. From this, it has been found that the compound of the general formula (I) has the effect of reducing the response speed despite the higher viscosity. It is expected that such an effect has a peculiar tendency, for example, in the physical constant of the elastic constant or rotational viscosity of the compound of the general formula (I). (Example 3) Nematic liquid crystal composition (2-
3)

[0079]

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Was prepared, and various properties of the composition were measured. The results were as follows. TN-I: 100.1 ° C. T → N: −70. ° C Vth: 2.01 Vγ: 1.15 Δε: 8.6 Δn: 0.173 The chiral substance “S-81” was added to this nematic liquid crystal composition.
1 "(manufactured by Merck) was added to prepare a mixed liquid crystal. On the other hand, an alignment film is formed by rubbing an organic film of “Sun Ever 610” (manufactured by Nissan Chemical Industries, Ltd.) on the opposing flat transparent electrode,
An STN-LCD display cell with a twist angle of 220 degrees was fabricated. The mixed liquid crystal was injected into this cell to construct a liquid crystal display, and the display characteristics were measured. As a result, a liquid crystal display device exhibiting STN-LCD display characteristics with excellent high time division characteristics and improved fast response was obtained. The chiral substance has a specific helical pitch P of the mixed liquid crystal due to the addition of the chiral substance and a cell thickness d of the display cell, Δn · d = 0.85, d / P = 0.
53 was added. (Example 4) Nematic liquid crystal composition (2-4)

[0081]

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Was prepared. The characteristics of this liquid crystal composition were favorable, as the birefringence was larger, the temperature range of the nematic phase was wider, the ratio between the saturation voltage and the threshold voltage was smaller, and the response speed was faster.

Hereinafter, the light scattering type liquid crystal display using the liquid crystal composition will be described in more detail. However, the invention is not limited to these examples. 80% of a liquid crystal composition (2-4) as a liquid crystal material and "HX-220" (manufactured by Nippon Kayaku Co., Ltd.) as a polymer-forming compound.
3.86%, 5.94% of lauryl acrylate, and 0.2% of 2-hydroxy-2-methyl-1-phenylpropan-1-one as a polymerization initiator are mixed at a ratio of 0.2%, and a light control layer of a uniform solution is mixed. A forming material was prepared. This light modulating layer forming material was prepared by using two sheets of I with a spacer having an average particle diameter of 10 μm.
Size 50 × 50 manufactured using a TO electrode glass substrate
A vacuum was injected into an empty cell of 10 mm at a temperature 10 ° C. higher than the transition temperature of the homogeneous solution. This is passed at a speed of 3.5 m / min under a metal halide lamp (80 W / cm2) while maintaining the temperature at 3 ° C. higher than the transition temperature of the homogeneous solution, and irradiated with ultraviolet rays having an energy equivalent to 500 mJ / cm2. Then, the polymer-forming compound was cured to obtain a liquid crystal device having a light control layer composed of a liquid crystal material and a transparent solid substance. When the cross section of the cured product formed between the substrates of the obtained liquid crystal device was observed using a scanning electron microscope, a transparent solid substance having a three-dimensional network structure composed of a polymer was recognized.

The characteristics of the obtained light-scattering type liquid crystal display are wider than those of the conventional light-scattering type liquid crystal device. It has no display characteristics and is useful for a display device such as a decorative display plate such as an advertising board, a clock, or a projection display device.

[0085]

The nematic liquid crystal composition of the present invention has a large birefringence Δn, exhibits a nematic phase over a wide temperature range, has an excellent effect of improving response characteristics, has a high voltage holding ratio, and has a high chemical stability. Is clearly higher. Therefore,
The nematic liquid crystal composition of the present invention can be used for an active matrix type, twisted nematic or super twisted nematic liquid crystal display device.

Further, it is possible to provide a liquid crystal display device which performs color display by the birefringence of the liquid crystal layer and the retardation plate. In particular, a large birefringence can reduce the thickness d of the liquid crystal layer, improve response characteristics, and provide display characteristics with a large amount of information. Furthermore, a useful device can be provided for a light scattering type liquid crystal display having a light control layer containing a liquid crystal material and a transparent solid substance.

Claims (22)

[Claims] 1. A compound of the general formula (I) (In the formula, R ¹¹ and R ¹² each independently represent a hydrogen atom or a linear alkyl group or an alkoxy group having 1 to 10 carbon atoms.) A liquid crystal composition containing a liquid crystal component B comprising a compound having a liquid crystal component A and having a dielectric anisotropy of +2 or more, wherein the liquid crystal composition has a dielectric anisotropy (Δε) of 3 or more. Having a nematic phase-isotropic liquid phase transition temperature (TN-I) of 60 ° C. or more and a crystal phase or a smectic phase-nematic phase transition temperature (T → I) of 0 ° C. or less. Characteristic nematic liquid crystal composition. 2. The liquid crystal component A contains 30 to 100% by weight of a compound represented by formula (I) wherein R ¹² is a methyl group, an ethyl group or a propyl group. 2. The nematic liquid crystal composition according to 1. 3. The liquid crystal composition according to claim 1, wherein
3 to 50% by weight.
The nematic liquid crystal composition according to the above. 4. The method according to claim 1, wherein the liquid crystal component B has a general formula (II-1)
(II-4) (Wherein, R ^{21 to} R ²⁴ each independently represent 2 to 10 carbon atoms.
Linear alkyl group, alkenyl group or C _s H _{2s + 1} -O-
Represents C _t H _2t, s and t are each independently an integer of 1 to 5, X ²¹ to X ²⁴ are each independently a fluorine atom, a chlorine _{atom, -OCF 3, -OCHF 2, -CF} 3 Or -CN, Y
^{21 to} Y ²⁸ each independently represent a hydrogen atom or a fluorine atom, W ^{21 to} W ²⁴ each independently represent a hydrogen atom or a fluorine atom, Z ^{21 to} Z ²³ each independently represent a single bond, -COO -,
_{-C 2 H 4 -, - C} 4 H 8 - represents, Z ²¹ is also -C≡C- or -
CH = CH-, Z ²⁴ and Z ²⁵ each independently represent a single bond, -COO-, -C≡C- or -CF = CF-, and m ^{1 to} m ⁴ each independently represent Represents an integer of 0 or 1, and m
³ + m ⁴ is an integer of 0 or 1, and the hydrogen atom (H) of the cyclohexane ring in each compound may be substituted with a deuterium atom (D). 4. The nematic liquid crystal composition according to claim 1, wherein the composition comprises a compound selected from the group consisting of: 5. The liquid crystal component B according to the general formula (II-1)
Compounds in which R ^{21 to} R ²⁴ in the formulas (II) to (II-4) are each independently an alkyl group or an alkenyl group having 2 to 5 carbon atoms;
And / or X ^{21 to} X ²⁴ are a fluorine atom, a chlorine atom, —OC
F _3, or claim 4 nematic liquid crystal composition according to the -CN, compound, characterized in that it contains 10 to 100 wt%. 6. The liquid crystal component B according to the general formula (II-1)
Z in the compound of ^{twenty one}And Z^{twenty two}Are each independently a single bond,
-COO-, -C_TwoH_Four-Or-C_FourH₈Compound represented by-
5. The composition according to claim 4, wherein the content is 0 to 100% by weight.
Is a nematic liquid crystal composition according to 5. 7. The liquid crystal component B represented by the general formula (II-2)
Z in the compound of ^{twenty four}Is a single bond, -COO- or -C≡C-
Containing 10 to 100% by weight of the compound represented by
7. The nematic liquid crystal set according to claim 4, 5 or 6, wherein
Adult. 8. The liquid crystal component B represented by the general formula (II-3)
Z in the compound of ^{twenty five}Is represented by a single bond or -C≡C-
Characterized by containing at least 10% by weight of a compound.
8. The nematic liquid crystal composition according to claim 4, 5, 6, or 7.
Stuff. 9. The liquid crystal composition according to claim 1, wherein
The composition according to claim 1, which is contained in an amount of 0 to 99% by weight.
9. The nematic liquid crystal composition according to 2, 3, 4, 5, 6, 7, or 8. 10. The liquid crystal composition comprises a liquid crystal component C comprising a compound having a dielectric anisotropy (Δε) of −2 to 2, wherein the liquid crystal component C has a general formula (III-1) to (III-4) (Wherein, R ^{31 to} R ³⁴ each independently represent a linear alkyl group or alkenyl group having 2 to 7 carbon atoms, and R ^{35 to} R ³⁸
Are each independently a linear alkyl group having 1 to 7 carbon atoms,
Alkoxy group, an alkenyl group, an alkenyloxy group or _{C u H 2u + 1 -O-} C v H 2v, u and v are each independently an integer of 1 to 5, Y ³¹ is a hydrogen atom, a fluorine atom Or
Represents -CH _3, Y ³² and Y ³³ are each independently represent a hydrogen atom or a fluorine atom, Z ³¹ to Z ³⁴ each independently represents a single _{bond, -COO -, - C 2 H} 4 - or -C ₄ H ₈ - represents, Z ³¹ is -
C≡C— or —CH ＝ CH—, Z ³⁵ represents a single bond, —C≡C—, —COO— or —CF ＝ CF—, and a ring A
³¹ and ring A ³² are each independently represent a cyclohexane ring or a cyclohexene ring, ring A ³³ and ring A ³⁴ are each independently represent a cyclohexane ring or a benzene ring, n ¹ ~n ⁵ are each independently 0 or Represents an integer of 1 and n ⁴ + n ⁵ is 0 or 1
And the hydrogen atom (H) of the cyclohexane ring in each compound may be substituted with a deuterium atom (D). 3. The composition according to claim 1, wherein the compound comprises one or more compounds selected from the group consisting of:
10. The nematic liquid crystal composition according to 3, 4, 5, 6, 7, 8, or 9. 11. The liquid crystal component C according to the general formula (III-
In the compound of 1), R ³¹ represents a linear alkyl group or alkenyl group having 2 to 5 carbon atoms, and R ³⁵ represents a linear alkyl group, alkoxy group, alkenyl group, or alkenyloxy group having 1 to 5 carbon atoms. A ring A ³¹ represents a cyclohexane ring, and when n ¹ is 0, Z ³² is a single bond or —COO
And / or when n ¹ is 1, Z ³¹
And a compound in which Z ³² is both represented by a single bond,
The nematic liquid crystal composition according to claim 10, wherein the composition is contained by weight. 12. The liquid crystal component C represented by the general formula (III-
R in the compound of 2)³²Is a linear group having 2 to 5 carbon atoms
Represents an alkyl group or an alkenyl group,³⁶Is the number of carbon atoms
1-5 linear alkyl groups, alkoxy groups, alkenyl
A alkenyloxy group, n^TwoIs 0, ring A
³²Represents a cyclohexane ring or a cyclohexene ring;
³³Is a single bond, -COO- or -C_TwoH_FourA compound represented by-
And / or n^TwoIs 1, the ring A³²Is cyclohexane
Represents a ring, Z³³Is a single bond or -C _TwoH_FourCompound represented by-
Is contained in an amount of 10 to 100% by weight.
12. The nematic liquid crystal composition according to 10 or 11. 13. The liquid crystal component C represented by the general formula (III-
13. The nematic liquid crystal composition according to claim 10, wherein Z ³⁵ in the compound of 3) contains 10 to 100% by weight of a compound represented by -C≡C-. 14. The liquid crystal composition according to claim 1, wherein the liquid crystal component C contains at most 70% by weight.
14. The nematic liquid crystal composition according to 0, 11, 12 or 13. 15. The liquid crystal composition according to claim 1, wherein the liquid crystal composition is a compound having a core structure having four six-membered rings and having a liquid crystal phase-isotropic liquid phase transition temperature of 100 ° C. or higher. 2. The composition according to claim 1, wherein the composition contains one or more species.
5. The nematic liquid crystal composition according to 4. 16. The liquid crystal composition has a dielectric anisotropy (Δε) of 4 to 30, a birefringence of 0.08 to 0.33 (Δn), and a nematic phase at 70 ° C. or higher. -Isotropic liquid phase transition temperature (TN-I), a crystal phase or a smectic phase-nematic phase transition temperature of -10 ° C or less (T →
The nematic liquid crystal composition according to any one of claims 1 to 15, wherein the composition is I). 17. The nematic liquid crystal composition according to claim 1, wherein the liquid crystal composition contains a compound having an optically active group having an induced helical pitch of 0.5 to 1000 μm. 18. An active matrix and a twisted liquid crystal using the nematic liquid crystal composition according to claim 17.
Nematic or super twisted nematic liquid crystal display. 19. The liquid crystal display device according to claim 18, wherein the thickness of the liquid crystal layer is 1 to 30 μm. 20. A light-scattering type liquid crystal display device having a light control layer containing the liquid crystal composition according to claim 1 and a transparent solid substance. 21. The light modulating layer, wherein the liquid crystal composition forms a continuous layer, and the transparent solid substance forms a uniform three-dimensional network structure in the continuous layer. The light-scattering type liquid crystal display device as described in the above. 22. The light scattering as claimed in claim 20, wherein the transparent solid substance is formed from a polymerizable composition containing a polymer-forming bifunctional monomer and a monofunctional monomer. Liquid crystal display device.