JP2001042793A - Nematic liquid crystal composition and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the voltage retention rate, to decrease or prevent electrochemical contamination of a liquid crystal material, and to improve display characteristics and production yield of a liquid crystal display device by using a nematic liquid crystal composition containing a specified compound. SOLUTION: The liquid crystal composition contains a liquid crystal component (A) consisting of one or more kinds of compounds expressed by formulae I, II, and the total proportion of the liquid crystal component (A) is 0.01 to 100 wt.%. In formulae, each of R1 to is a 1-10C alkyl group or a 2-10C alkenyl group, Q1 is F, Cl, CF3 or the like, each of X1 and X2 is H, F, Cl, CF3 or the like, each of K1 to K2 and P3 to P3 is a single bond, -COO-, -OCO- or the like, each of A1 to A4 and B1 to B4 is a 1,4-phenylene, a 2 or 3-fluoro-1,4-phenylene or the like, and each of k1, k2, p1, p2 is 0 or 1. However, at least one of hydrogen atoms present in the side chain groups, polar groups, connecting groups and rings is substituted with a deuterium atom.

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 a TN-LCD.
(Twisted nematic liquid crystal display element)
It is used in watches, calculators, electronic organizers, pocket computers, word processors, personal computers and the like. On the other hand, with the increase in processing information of OA equipment, Scheffer et al. [SID '85 Digest, p.120 1985
Year], Kinukawa et al. [SID '86 Digest, p.122 1986], STN (Super Twisted Nematic) -L
CDs have been developed and have begun to spread widely to displays for high information processing such as portable terminals, electronic organizers, pocket computers, word processors, personal computers, and monitor displays.

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]. In addition, in order to achieve a brighter display and higher contrast ratio, instead of the color filter layer, a new reflective color liquid crystal display system using the birefringence of liquid crystal and a retardation plate [Television Society Technical Report vol. 14 No10.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.

In particular, in applications where the display area is to be increased, uniformity of display and high contrast with respect to the temperature distribution of the backlight are required, and a liquid crystal material having more stable alignment and less temperature dependency is required. A birefringence index corresponding to a predetermined value is required in order to suppress variations in cell thickness. Further, since high duty driving is performed due to an increase in the number of pixels, responsiveness, gradation, and the like corresponding to this are also emphasized. On the other hand, for small and medium-sized portable displays,
The stability of the display with respect to the use environment temperature is an important point, and a liquid crystal material having a lower driving voltage capable of reducing responsiveness and power consumption, or a temperature of -30 to 0 ° C. or 40 to 80 ° C.
It is required that the temperature dependence of the drive voltage in the temperature range of ° C. be small, high steepness be required, and that the frequency dependence corresponding to the desired duty drive be small in this temperature range. Further, the electrical resistance (specific resistance) of the liquid crystal must be set to a predetermined value so as not to become too high in order to eliminate burn-in, although it is necessary to avoid that the electric resistance (resistivity) is too low in order to reduce power consumption. Have been. As described above, there is still a demand for a liquid crystal material which is differentiated in more detail and which is slightly improved.

[0005] Suitable liquid crystal materials include birefringence,
Physical properties such as elastic constant, dielectric anisotropy, lower viscosity, wider nematic temperature, chemical stability, electrical stability (desired specific resistance, voltage holding ratio), etc. It is necessary to comprehensively optimize individual characteristics such as a pretilt angle and a wider d / p margin.
At present, proposals for new liquid crystal compounds or liquid crystal compositions are 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. In the active matrix display method, a TFT (thin film transistor) or a metal insulator metal (MIM) is used for each pixel, and a high voltage holding ratio is emphasized in this method. In addition, in order to obtain a wider viewing angle characteristic, a super TFT [Asia Display '95 Diges
t, p. 707 1995] by Kondo et al.
(Hereinafter, these active matrix display type liquid crystal display elements are collectively referred to as TFT-LCD.) To cope with such a display element, a new liquid crystal compound or liquid crystal composition such as the one disclosed in 233626,
A proposal such as Japanese Patent Publication No. 4-501575 has been made.

[0007] As a liquid crystal material to be used for a TFT-LCD using a polysilicon technology, which has recently attracted attention, a liquid crystal material that is resistant to contamination, including higher characteristics in terms of voltage holding ratio, and has a lower driving voltage. A liquid crystal material exhibiting faster response and a liquid crystal material having a birefringence of 0.08 to 0.15 are required. Further, for the purpose of improving the yield, a demand for a liquid crystal material which causes less display defects and a liquid crystal material which can stably exhibit a higher pretilt angle and the like has been further differentiated.

As a bright and high-contrast liquid crystal device which does not require a polarizing plate or an alignment treatment, a liquid crystal display device in which liquid crystal droplets are dispersed in a polymer is disclosed in Japanese Patent Publication No. 58-501631.
Gazette, US Pat. No. 4,350,047, Japanese Patent Publication No. Sho 6
These are known from JP-A-1-502128, JP-A-62-2231 and the like. (Hereinafter, these liquid crystal display elements are collectively referred to as PDLC.) These are used to optimize the individual refractive index of the liquid crystal material and the refractive index of the polymer and to apply a high voltage to obtain sufficient transparency. Had the necessary problems. On the other hand, U.S. Pat. No. 5,30 is disclosed as a technology that enables low voltage driving, high contrast, and time division driving.
4,323, JP-A-1-198725,
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 network in the continuous layer is disclosed. (Hereafter, this liquid crystal display element is called PN-LCD
Called)

As a liquid crystal material for this purpose, EP-A-359,146 discloses a method for optimizing the birefringence and dielectric anisotropy of a liquid crystal material.
Japanese Patent Application Laid-Open No. 5-339573 discloses a technique for specifying the elastic constant of a liquid crystal material, and JP-A-5-339573 discloses the use of a fluoro compound. However, there are problems such as high resistance value, excellent voltage holding ratio, low driving voltage, strong light scattering, high contrast ratio, fast response speed, and good temperature characteristics. New proposals are still being made.

As described in detail above, demands for liquid crystal display elements include finer and higher-density display capacity, faster response speed to driving voltage and environmental temperature, and higher chemical and electrical stability. Lower driving voltage, higher gradation, higher contrast with respect to the use environment temperature and the viewing angle, and the like. For this reason, it has nematic properties over a wide temperature range, maintains a nematic phase for a long time at low temperature storage,
The desired drive voltage, with lower viscosity, which can improve the responsiveness,
In particular, research and development of liquid crystal materials that can achieve lower driving voltages are still being conducted. The design of the birefringence, dielectric anisotropy and elastic constant and their temperature dependence, the wavelength dependence of the birefringence and the frequency dependence of the dielectric anisotropy corresponding to the duty number are also improved. It is attracting attention.

The present invention is characterized in that a compound having a deuterium atom is selectively contained. Such a nematic liquid crystal composition is hardly known.

[0012]

The present invention relates to a compound represented by the general formula (I-
The nematic liquid crystal composition containing at least one of the compounds represented by 1) and (I-2) is intended to solve or at least slightly improve the demand for the liquid crystal material as described above. And to improve the characteristics of the liquid crystal display element. Specifically, it is to improve the voltage holding ratio and to reduce or prevent the electrochemical contamination of the liquid crystal material.
Various display characteristics of CD and STN-LCD or IPS, MVA, OCB,
An object of the present invention is to improve the display characteristics of an active matrix in an ECB mode or to improve the yield of these liquid crystal display elements.

[0013]

According to the present invention, in order to solve the above-mentioned problems, a liquid crystal composition has a general formula (I-1) or (I-2)

Embedded image (Wherein, R ^{1 to} R ³ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, wherein the alkyl group or the alkenyl group is unsubstituted or substituted. It can have one or more F, Cl, CN, CH ₃ or CF ₃ , and one or more CH ₂ groups present in the alkyl group or the alkenyl group are
O atoms may be substituted with O, CO or COO as those not directly bonded to each other, and Q ¹ is each independently F, Cl, CF ₃ , OCF ₃ , OCF ₂ H, OCFH ₂ , N
Represents CS or CN, and X ¹ and X ² are each independently H,
Represents F, Cl, CF ₃ , OCF ₃ or CN, K ^{1 to} K ³ ,
P ^{1 to} P ³ each independently represent a single bond, —COO—, —OCO—,
_{-CH 2 O -, - OCH 2} -, - CH = CH -, - CF = CF-,
_{-C≡C -, - (CH 2)} 2 -, - (CH 2) 4 -, - CH = CH- (C
H ₂ ) ₂ -,-(CH ₂ ) ₂ -CH = CH-, -CH = N-, -CH =
NN = CH- or -N (O) = N-, wherein rings A ^{1 to} A ⁴ , B
^{1 to} B ⁴ are each independently 1,4-phenylene, 2 or 3-
Fluoro-1,4-phenylene, 2,3-difluoro-
1,4-phenylene, 3,5-difluoro-1,4-phenylene, 2 or 3-chloro-1,4-phenylene,
2,3-dichloro-1,4-phenylene, 3,5-dichloro-1,4-phenylene, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene, trans-
1,4-cyclohexenylene, trans-1,3-dioxane-2,5-diyl, trans-1-sila-1,4
-Cyclohexylene, trans-4-sila-1,4-cyclohexylene, naphthalene-2,6-diyl, 1,
2,3,4-tetrahydronaphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydrophenanthrene-2,7-diyl, 1, 2,3,4,5
6,7,8, -octahydrophenanthrene-2,7
-Diyl, tetradecahydrophenanthrene-2,7
-Diyl or fluorene-2,7-diyl, wherein one or two or more CH groups present in a naphthalene-2,6-diyl ring may be substituted with an N group; -Diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-
Diyl, 9,10-dihydrophenanthrene-2,7
-Diyl, 1,2,3,4,5,6,7,8, -octahydrophenanthrene-2,7-diyl, tetradecahydrophenanthrene-2,7-diyl or fluorene-2,7-diyl are non- It may have one or more F, Cl, CF ₃ , OCF ₃ or CH ₃ as a substituent or a substituent, and k ^{1 to} k ² , p ^{1 to} p ² each independently represent 0 or 1. And the atoms constituting the compound of the above general formula may be substituted by its isotope atoms. However, the side chain group R ¹
To R ³ , polar groups Q ¹ , X ¹ , X ² , linking groups K ^{1 to} K ³ , P ¹ to
At least one or more of the hydrogen atoms present in P ³ and rings A ^{1 to} A ⁴ and B ^{1 to} B ⁴ are substituted with deuterium atoms. A) a liquid crystal component A comprising one or more compounds selected from the compounds represented by the formula (1), wherein the total of the liquid crystal component A is 0.01 to 100% by weight. A composition is provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The liquid crystal composition of the present invention comprises a liquid crystal component A comprising a compound represented by formulas (I-1) and (I-2).
As an essential component. As will be described in more detail in Examples, a nematic liquid crystal composition having a higher voltage holding ratio has been obtained.

In the present invention, the lower formulas of the general formulas (I-101) to (I-210) are shown as more preferred compounds of the general formulas (I-1) and (I-2).

[0016]

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[0017]

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[0018]

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When the liquid crystal component A contains a compound represented by the general formula (I-1), one or two compounds selected from the compounds represented by the general formulas (I-101) to (I-127) are used. When the liquid crystal component A contains a compound represented by the general formula (I-2), or a combination of the compounds represented by the general formulas (I-101) to (I-127). Containing one or more compounds selected from compounds represented by formulas (I-201) to (I-210), or represented by formulas (I-201) to (I-210) When a compound having a positive dielectric anisotropy is desired to be used as a main component, and a compound having a negative dielectric anisotropy is desired. Preferably uses the general formula (I-2) as a main component.

From such a viewpoint, the general formulas (I-1) and (I-
The more preferable form of the basic structure in the compound represented by 2) is a compound represented by the following general formulas (I-1a) to (I-2aw).

[0021]

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[0022]

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[0023]

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More preferred forms of the formula (I-6) in the side chain groups R ^{1 to} R ³ are the following general formulas (I-6a) to (I-6j)
It is a compound represented by these.

[0025]

Embedded image (In the formula, n, m, x, and y each independently represent a natural number.)

The polar groups Q ¹ are —OCF ₂ D, —OCFD ₂ , and —OCFHD couplers K ^{1 to} K ³ , and P ^{1 to} P ³ are —CD ₂ O—, —CHDO—, and —OC
D _2- , -OCDH-, -CD = CD-, -CH = CD-, -CD = CH
-, - (CD2) 2 - , - (CDH) 2 -, - (CD 2) 4 -, - (CDH)
_{4 -, - CD = CD- (} CD 2) 2 - ring ^{A 1 ~A 4, B 1 ~B} 4 the general formula shown below (I-7a) ~
(I-7jn)

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

Embedded image Is a more preferred form.

The compound according to the present invention comprises a hydrogen source
Is a compound in which a hydrogen atom is consciously replaced by a deuterium atom.
Good solubility, elastic constant, pretilt angle, voltage holding ratio, etc.
Shows good effect. Preferred forms are the side chains described above.
A hydrogen atom present in a group, linking group or ring is a deuterium atom
Is a compound substituted with More preferably, in the side chain group
If present, a substituted or unsubstituted alkyl group, alkenyl group, ring
If substituted or unsubstituted 1,4-phenylene, pirimi
Gin-2,5-diyl, trans-1,4-cyclohexyl
Silene, trans-1,4-cyclohexenylene or to
Lance-1,4-dioxane-2,5-diyl, naphtha
Len-2,6-diyl, 1,2,3,4-tetrahide
Lonaphthalene-2,6-diyl, decahydronaphthale
-2,6-diyl, phenanthrene-2,7-diyl
9,10-dihydrophenanthrene-2,7-di
Il, 1,2,3,4,5,6,7,8, -octahigh
Drophenanthrene-2,7-diyl, tetradecahai
Drophenanthrene-2,7-diyl or fluorene-
For a 2,7-diyl linking group, -CH_TwoO-, -OCH_Two-,
-(CH_Two)_Two-,-(CH_Two)_Four-, -CH = CH- (CH_Two)_Two-,-
(CH_Two)_Two-CH = CH-, -CH = N-, -CH = NN-C
H-. Particularly preferably, an alkyl group, an alkenyl
To the group 1,4-phenylene, trans-1,4-cyclo
Xylene,-(CH _Two)_Two-,-(CH_Two)_Four-

At present, a polyimide-based alignment film used for TN-LCD, STN-LCD or TFT-LCD is often 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 as needed 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 by substitution of deuterium, and by applying this, desired liquid crystal display characteristics and uniform liquid crystal display characteristics can be obtained. It has been found that the alignment can be achieved from a liquid crystal material. This technique can be applied to the present invention.

Further, when a compound in which a hydrogen atom is replaced with a deuterium atom is frequently used, there is a special effect of maintaining a higher voltage holding ratio with respect to contamination of impurities, and the
It is suitable for the display characteristics of TFT-LCD, PDLC, PN-LCD, etc. and the production yield. Such effects can be considered that the properties of heavy water, that is, differences in the equilibrium constant and rate constant of the reaction, low ionic mobility, and low solubility of inorganic substances and oxygen are also expressed in the liquid crystal compound. . In order to maintain a higher voltage holding ratio, the compound of the liquid crystal component A can be contained in an amount of 0.01 to 100% by weight based on the total amount of the liquid crystal composition, but is preferably 30 to 100% by weight. 50 to 100% by weight is more preferable, and 70 to 100% by weight.
% By weight is more preferred.

The ratio of the compound of the general formula (I-1) to the compound of the general formula (I-2) in the liquid crystal component A can be selected from the range of 0: 100 to 100: 0. When a positive dielectric anisotropy is desired, the content of the general formula (I-1) is 100 to 100%.
A range of 20% by weight is preferred, a range of 100 to 30% by weight is more preferred, and a range of 95 to 40% by weight is still more preferred. When a negative dielectric anisotropy is desired, the general formula (I-
The content of 2) is preferably in the range of 100 to 0% by weight.

High reliability STN-LCD and active STN-L
It is preferable that the CD, TFT-LCD, PDLC, PN-LCD and the like are formed of a compound containing no nitrogen atom or oxygen atom. From this viewpoint, in the general formula (I-1), Q ¹ is F, Cl, CF
₃ , OCF ₃ and OCF ₂ H, and X ¹ and X ² are H, F and C
1, CF ₃ and OCF ₃ , K ^{1 to} K ⁵ are a single bond, —CH
= CH -, - C≡C -, - (CH 2) 2 -, - (CH 2) 4 -, - CH =
_{CH- (CH 2) 2 -,} - (CH 2) a ₂ -CH = CH-, compound preferably contains 50 to 100 wt%.

A liquid crystal composition having a positive dielectric anisotropy is desired.
In the case where the compound of the general formula (I-1) is used,
Another preferred embodiment of the crystal component A includes the compounds shown below.
Have. (I): using compounds of the general formulas (I-101) to (I-127)
If Q¹Is F, Cl, CF_Three, OCF_Three, OCF_TwoH
, X¹Is H, Cl, CF_Three, OCF_Three, OCF_TwoH
, X^TwoIs H, Cl, CF_Three, OCF_Three, OCF_TwoH
Compound. (Ii): using compounds of the general formulas (I-101) to (I-127)
If Q¹Is F, Cl, CF_Three, OCF_Three, OCF_TwoH
, X¹Is F and X^TwoIs Cl, CF_Three, OCF _Three, OC
F_TwoA compound which is H.

When a liquid crystal composition having a negative dielectric anisotropy is desired, when a compound of the general formula (I-2) is used, another preferred embodiment of the liquid crystal component A contains a compound shown below. I do. (Iii): When compounds of the general formulas (I-201) to (I-210) are used, compounds in which W ¹ , W ³ , Z ¹ , Z ³ are substituted by F, Cl, etc., naphthalene-2,7 -A compound having a partial structural formula in which diyl, phenanthrene-2,7-diyl, and fluorene-2,7-diyl are substituted with two or more polar groups. (Iv): From this viewpoint, it is preferable to contain 10 to 100% by weight of the compounds of the general formulas (I-2y) to (I-2aw),
More preferably, the content is 20 to 95% by weight. (V): In order to improve the temperature range and responsiveness of the nematic phase, compounds that are preferably combined with the compounds of (iii) and (iv) are represented by formulas (I-2a) to (I-2c), I-
2e), (I-2h), (I-2i), (I-2m), (I-2t), (I-
2u).

The active STN-LCD is intended to obtain higher contrast at a wide viewing angle and to improve the response time especially at the fall.
Is actively driven using, for example, TFT or MIM technology.

The crystal phase or the smectic phase-nematic phase transition temperature is preferably 0 ° C. or lower, preferably -10 ° C. or lower, more preferably -20 ° C. or lower, and particularly preferably -3 ° C. or lower.
0 ° C. or less. The nematic phase-isotropic liquid phase transition temperature is 50 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and further preferably 80 ° C. to 180 ° C. The liquid crystal composition of the present invention may have a dielectric anisotropy of 1 or more, but is preferably in the range of 2 to 40. If so, the range of 7 to 30 is preferable. The smaller or medium birefringence is preferably in the range of 0.02 to 0.18, and the larger birefringence is preferably 0.18 to 0.40.
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 thickness d between the substrates in the TN-LCD, STN-LCD and TFT-LCD is preferably 1 to 12 μm, more preferably 1 to 10 μm, and still more preferably 1.5 to 7 μm. Also,
The product of the thickness d and the birefringence Δn is preferably 0.2 to 5 μm, more preferably 0.3 to 1.6 μm, and more preferably around 0.5 μm, 0.7 to 1.0 μm, and around 1.2 μm. preferable. In the case of PDLC and PN-LCD, 1 to 100 μm is preferable,
3 to 50 μm is more preferable, and 4 to 14 μm is still more preferable.

When the liquid crystal composition of the present invention is intended to have a quick response to the magnitude of the driving voltage, the following can be performed. 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. When a particularly low driving voltage is intended, the liquid crystal composition of the present invention has a dielectric anisotropy of 1%.
It is preferably in the range of 5 to 30, and particularly preferably in the range of 18 to 28.

The above nematic liquid crystal composition is useful for TN-LCDs, STN-LCDs, and TFT-LCDs having a high response speed, and the birefringence between the liquid crystal layer and the retardation plate can be obtained without using a color filter layer. Thus, the present invention is useful for a liquid crystal display device capable of performing color display by using a liquid crystal display device of a transmission type or a reflection type. This liquid crystal display element has a substrate having a transparent electrode layer and at least one of which is transparent, in which molecules of the nematic liquid crystal composition are twisted between the substrates. The twist angle is 3 depending on the purpose.
It can be selected in the range of 0 ° to 360 °, 90 ° to
It is preferable to select in the range of 270 °, and 45 ° to 1
It is particularly preferred to select in the range of 35 ° or in the range of 180 ° to 260 °. For this reason, the liquid crystal composition of the present invention can contain a compound having an optically active group having an induced helical pitch p of 0.5 to 1000 μm. Such compounds include cholesteric derivatives, chiral nematics, and ferroelectric liquid crystals.

As typical examples, it is preferable to use, for example, cholesteryl nonanate, C-15, CB-15, S-811 and the like. More specifically, for example, compounds represented by the following general formulas (IV-3a) to (IV-3ab).

[0046]

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[0047]

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A more specific usage will be described. It is known that the induced helical pitch becomes longer and shorter as the temperature rises, but one of these may be used alone or in combination of two or more. good. The mixing amount is 0.001% by weight to 1%.
0% by weight is preferred, and 0.05% to 3% by weight.
Is more preferable, and 0.1 to 3% by weight is further preferable. However, these quantities are equal to the torsion angle θ described above.
It is a matter of course that a predetermined induced helical pitch is set depending on the thickness d between the substrate and the substrate. For example, TN-LCD, STN-LC
D, In the TFT-LCD, the quotient d / p of the thickness d between the substrates and the induced helical pitch p can be selected from the range of 0.001 to 24, but is preferably in the range of 0.01 to 12; .
The range of 1-2 is more preferred, the range of 0.1-1.5 is still more preferred, the range of 0.1-1 is even more preferred,
A range of 0.1 to 0.8 is particularly preferred.

The pretilt angle obtained by the alignment film provided on the transparent electrode substrate is preferably selected in the range of 1 ° to 20 °. When the twist angle is 30 ° to 100 °, the pretilt angle is 1 ° to 4 °. Is preferably 100 ° to 18 °.
At 0 °, a pretilt angle of 2 ° to 6 ° is preferable.
A pretilt angle of 3 ° to 12 ° is preferable for ° to 260 °, and a pretilt angle of 6 ° to 20 ° is preferable for 260 ° to 360 °. As a specific application, 1 ° for TN-LCD
A pretilt angle of ~ 6 ° is preferable, and 2 ° for STN-LCD
A pretilt angle of ~ 12 ° is preferred, and 2 for TFT-LCD.
A pretilt angle of ° to 12 ° is preferable, and TFTs in IPS mode
For a -LCD, a pretilt angle of 0 ° to 3 ° is preferable.

The liquid crystal composition of the present invention may be added with dichroic dyes such as anthraquinone type, azo type, azoxy type, azomethine type, merocyanine type, quinophthalene type and tetrazine type as a use other than the polymer dispersed liquid crystal. Thus, it can be used as a liquid crystal composition for a guest host (GH). Further, by adding the above-mentioned compound having an optically active group, it can be used as a liquid crystal composition of a phase transition type display (PC) and a white tailor type display. Furthermore, it can also be used as a liquid crystal composition for birefringence control type display (ECB) or dynamic scattering type display (DS). Further, as another usage, the liquid crystal composition of the present invention can be added for the purpose of adjusting the phase sequence of the ferroelectric liquid crystal. It can also be used as a polymer stabilized liquid crystal composition for liquid crystal display. In this case, the compound or composition having the photocurable side chain group can be used.

Further, as another application method, the above-mentioned compound having a photocurable side chain group or the composition of the present invention
It can be used as a curable liquid crystal and used for optical members such as retardation films, optical lenses and various optical filters. Further, it can be used by applying to liquid crystal display-related members such as a micro color filter, a polarizing plate and an alignment film.

At present, liquid crystal display devices are in a state of intense price competition. From this standpoint, it has been an issue how to optimize the display characteristics for various uses in a liquid crystal material, and two bottles composed of two types of liquid crystal materials and four types of liquid crystal materials composed of four types of liquid crystal materials have become issues. There is a demand for a systemized liquid crystal material such as a bottle. Typical characteristics include a threshold voltage, a birefringence, and a nematic phase-isotropic liquid phase transition temperature. For example, if a two-bottle system composed of a liquid crystal material having a higher threshold voltage and a lower liquid crystal material having the same other characteristics is used, two types of liquid crystal can be used without being restricted by the driving electronic components used. Timely compounding of materials allows for faster and cheaper handling. The present invention is also useful to meet this viewpoint, nematic liquid crystal compositions (1-01) ~ (1-11) and the composition obtained by partially replacing it may be used by mixing timely. it can. Naturally, these methods of use can be performed including the nematic liquid crystal compositions (3-01) to (3-10) of Examples described later.

The liquid crystal composition of the present invention can be obtained by containing the liquid crystal component A described in detail above.
In this manner, nematic liquid crystal compositions (1-01) to (1-11) are shown below as preferred examples, but the present invention is not limited to these examples.

Preferred Composition Example: Nematic Liquid Crystal Composition (1-01)

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Preferred composition example: Nematic liquid crystal composition (1-02)

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Preferred composition example: Nematic liquid crystal composition (1-03)

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Preferred Composition Example: Nematic Liquid Crystal Composition (1-04)

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Preferred composition example: Nematic liquid crystal composition (1-05)

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Preferred composition example: Nematic liquid crystal composition (1-06)

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Preferred composition example: Nematic liquid crystal composition (1-07)

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Preferred composition example: Nematic liquid crystal composition (1-08)

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Preferred composition example: Nematic liquid crystal composition (1-09)

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Preferred composition example: Nematic liquid crystal composition (1-10)

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Preferred Composition Example: Nematic Liquid Crystal Composition (1-11)

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[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”, and — (CH ₂ ) ₂ — and —C ₂ H ₄ — or — (CH
₂ ) ₄ -and -C ₄ H ₈ -are the same.

In the examples, physical properties of the liquid crystal composition and TN-L
The display characteristics of the liquid crystal display device constituting the CD are as follows. T _NI : Nematic phase-isotropic liquid phase transition temperature (° C.) T _{→ N} : Solid phase or smectic phase-nematic phase transition temperature (° C.) Δε: dielectric anisotropy at 20 ° C. Δn: at 20 ° C. Birefringence Vth: threshold voltage (V) at 20 ° C when TN-LCD is constructed

A liquid crystal display device exhibiting STN-LCD display characteristics can be manufactured as follows. A mixed liquid crystal is prepared by adding a chiral substance “S-811” (manufactured by Merck) to the liquid crystal composition. An alignment film is formed by rubbing an organic film of "Sunever 610" (manufactured by Nissan Chemical Industries, Ltd.) on the opposing flat transparent electrode to form an STN-LCD display cell having a twist angle of 240 degrees. The mixed liquid crystal is injected into this cell to constitute a liquid crystal display. The chiral substance is such that the specific helical pitch P of the mixed liquid crystal and the cell thickness d of the display cell due to the addition of the chiral substance are Δn · d = 0.85 and d / P = 0.50.
Was added so that

A liquid crystal display device exhibiting IPS mode display characteristics can be manufactured as follows by providing an alignment film on a substrate on which parallel chromium electrodes are formed at intervals of 10 μm. An alignment film is provided on a substrate having no electrode. A cell is prepared by bonding both substrates so that the cell thickness is 4 μm and the orientation of the liquid crystal is anti-parallel. A liquid crystal display is constructed by injecting the mixed liquid crystal into this cell.

The chemical stability of the composition was as follows: liquid crystal composition 2 g
Was placed in an ampoule tube, vacuum-degassed, and then subjected to a process of purging with nitrogen and sealed, and a heating promotion test at 150 ° C. for 1 hour was performed.
The specific resistance of the liquid crystal composition before the test, the specific resistance after the heating acceleration test, the voltage holding ratio before the test, and the voltage holding ratio after the heating acceleration test were measured.

(Example 1)

Embedded image A nematic liquid crystal composition (3-01) was prepared, and various characteristics of the composition were measured. The results were as follows. Physical Properties of Liquid Crystal Composition T _NI : 88.8 ° C. T _{→ N} : −70. ° C: ε: 7.3 Δn: 0.094 Reliability characteristics of liquid crystal composition Specific resistance before test: 1.3 × 10 ¹³ Ω · cm Specific resistance after heating acceleration test: 7.0 × 10 ¹² Ω -Cm Voltage holding ratio before test: 99.5% Voltage holding ratio after heating acceleration test: 98.8% TN-LCD display characteristics with a twist angle of 90 degrees (cell thickness 6 μm) Vth: 1.54 V

This nematic liquid crystal composition can be operated in a wider temperature range since T _NI is high and T _{→ N} is low. In addition, 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. An active matrix liquid crystal display device using this composition as a basic constituent material is excellent in that the leakage current is small and flicker does not occur.

(Example 2)

Embedded image A liquid crystal composition (3-02) was prepared.

(Embodiment 3)

Embedded image , A nematic liquid crystal composition (3-03) was prepared.

(Comparative Example 1)

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In order to show the superiority of the present invention, a mixed liquid crystal (b-01) containing no deuterium atom was prepared and its reliability was measured. The results were as follows. Reliability characteristics of liquid crystal composition Specific resistance before test: 1.2 × 10 ¹³ Ω · cm Specific resistance after heating acceleration test: 5.6 × 10 ¹² Ω · cm Voltage holding ratio before test: 99.1% Voltage holding ratio after heating acceleration test: 98.2%

(Example 4) and (Comparative Example 2) In order to further show the superiority of the present invention, the liquid crystal composition (3-0
Stearic acid was added in an amount of 0.2% by weight to liquid crystals (b-01) mixed with (1) to (3-03) and reliability characteristics were measured. The results were as follows. Reliability characteristics of liquid crystal composition Liquid crystal composition (3-01) Voltage holding ratio before test: 99.5% Voltage holding ratio after heating acceleration test: 98.6% Liquid crystal composition (3-02) Voltage before test Retention: 96.1% Voltage retention after heating promotion test: 94.5% Liquid crystal composition (3-03) Voltage retention before testing: 96.3% Voltage retention after heating promotion test: 94.9% Liquid crystal composition (b-01) Voltage holding ratio before test: 88.7% Voltage holding ratio after heating acceleration test: 86.9%

The liquid crystal composition (3-01) of the present invention contains 75% by weight, and the liquid crystal compositions (3-02) and (3-03) contain 30% by weight of a compound substituted with a deuterium atom. . The mixed liquid crystal (b-01) of the comparative example did not contain a compound substituted with a deuterium atom. Comparing the voltage holding ratio of this liquid crystal, (1)
(3-01) to (3-03) show a small but small change in the voltage holding ratio after the heating acceleration test as compared to (b-01). (2)
(3-01) to (3-03) showed the characteristic that the decrease in the voltage holding ratio when stearic acid was added was smaller than that in (b-01). This indicates that the liquid crystal composition of the present invention has excellent anti-staining properties.

(Embodiment 5)

Embedded image A liquid crystal composition (3-05) was prepared.

(Embodiment 6)

Embedded image A nematic liquid crystal composition (3-06) was prepared.

(Embodiment 7)

Embedded image A nematic liquid crystal composition (3-07) was prepared.

(Embodiment 8)

Embedded image A nematic liquid crystal composition (3-08) was prepared.

(Embodiment 9)

Embedded image A nematic liquid crystal composition (3-09) was prepared.

(Embodiment 10)

Embedded image A nematic liquid crystal composition (3-10) was prepared.

[0084]

The nematic liquid crystal composition of the present invention comprises a liquid crystal component A comprising a compound represented by any one of formulas (I-1) to (I-2).
As an essential component, when mixed with the liquid crystal composition, the operating temperature range of the liquid crystal display characteristics is expanded by improving compatibility, improving low-temperature storage, etc., and a side chain group substituted by a deuterium atom, a linking group,
By having a polar group or a ring, more deuterium atoms can be introduced than conventional compounds, and a more improved voltage holding ratio can be obtained. 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.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02F 1/13 500 G02F 1/13 500 G09F 9/30 338 G09F 9/30 338 F Term (Reference) 4H027 BA01 BA06 BB01 BB02 BB03 BB04 BB06 BB11 BB13 BC04 BC06 BD01 BD02 BD24 BE01 CB01 CB02 CB04 CC04 CE04 CK04 CM04 CN01 CN05 CQ04 CR01 CR04 CT02 CT03 CT04 CU04 CW02 DE04 DK04 DK05 DM01 DM04 DP01 BA03A03 A03 BA03 A03

Claims (7)

[Claims] A liquid crystal composition represented by the following general formulas (I-1) and (I-2): (Wherein, R ^{1 to} R ³ each independently represent an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, wherein the alkyl group or the alkenyl group is unsubstituted or substituted. It can have one or more F, Cl, CN, CH ₃ or CF ₃ , and one or more CH ₂ groups present in the alkyl group or the alkenyl group has an O atom O 1, CO or COO may be substituted as not directly bonded to each other, and Q ¹ is each independently F, Cl, CF ₃ , OCF ₃ , OCF ₂
H, OCFH ₂ , NCS or CN; X ¹ and X ² each independently represent H, F, Cl, CF ₃ , OC
Represents F ₃ or CN, and K ^{1 to} K ³ and P ^{1 to} P ³ each independently represent a single bond, —COO—,
_{-OCO -, - CH 2 O -} , - OCH 2 -, - CH = CH -, - C
F = CF -, - C≡C - , - (CH 2) 2 -, - (CH 2) 4 -, - CH
= CH- (CH ₂ ) ₂ -,-(CH ₂ ) ₂ -CH = CH-, -CH = N
-, -CH = NN-CH- or -N (O) = N-, wherein the rings A ^{1 to} A ⁴ and B ^{1 to} B ⁴ are each independently 1,4-phenylene, 2 or 3- Fluoro-1,4-phenylene, 2,3
-Difluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, 2 or 3-chloro-1,4-
Phenylene, 2,3-dichloro-1,4-phenylene,
3,5-dichloro-1,4-phenylene, pyrimidine-
2,5-diyl, trans-1,4-cyclohexylene, trans-1,4-cyclohexenylene, trans-1,3-dioxane-2,5-diyl, trans-1
-Sila-1,4-cyclohexylene, trans-4-sila-1,4-cyclohexylene, naphthalene-2,6-
Diyl, 1,2,3,4-tetrahydronaphthalene-
2,6-diyl, decahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, 9,10-dihydrophenanthrene-2,7-diyl, 1,2,2
3,4,5,6,7,8, -octahydrophenanthrene-2,7-diyl, tetradecahydrophenanthrene-2,7-diyl or fluorene-2,7-diyl, and naphthalene-2,6- 1 present in the diyl ring
One or more CH groups may be substituted with an N group, and naphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7 -Diyl, 9,10-dihydrophenanthrene-2,7-diyl, 1,2,3,4,5,6
7,8-octahydrophenanthrene-2,7-diyl, tetradecahydrophenanthrene-2,7-diyl or fluorene-2,7-diyl is unsubstituted or has one or more F, Cl or , CF ₃ , OCF ₃
Or k ₃ , k ^{1 to} k ² , p ^{1 to} p ² each independently represent 0 or 1, and atoms constituting the compound of the above general formula are substituted with isotope atoms thereof. Is also good.
Provided that the side groups R ^{1 to} R ³ , the polar groups Q ¹ , X ¹ and X ² , the linking groups K ^{1 to} K ³ , P ^{1 to} P ³ and the rings A ^{1 to} A ⁴ and B ^{1 to} B ⁴ At least one hydrogen atom is replaced with a deuterium atom. A) a liquid crystal component A comprising one or more compounds selected from the compounds represented by the formula (1), wherein the total of the liquid crystal component A is 0.01 to 100% by weight. Composition. 2. The nematic liquid crystal composition according to claim 1, wherein the liquid crystal component A satisfies at least one of the following conditions. (i) The compounds of the above formulas (I-1) and (I-2), wherein at least two of the hydrogen atoms present in the side chain groups R ^{1 to} R ³ are substituted with deuterium atoms. (ii) the general formula (I-1), in the compound of (I-2), compounds in which at least one is substituted with deuterium atoms of hydrogen atoms present in the polar group Q ^1. (iii) In the compounds of the general formulas (I-1) and (I-2),
Compounds in which at least one of the hydrogen atoms present in the linking groups K ^{1 to} K ³ and P ^{1 to} P ³ has been replaced with a deuterium atom. (iv) In the compounds of the general formulas (I-1) and (I-2), at least one of the hydrogen atoms present in the rings A ^{1 to} A ⁴ and B ^{1 to} B ⁴ is replaced with a deuterium atom. Compound. (v) The liquid crystal component A contains one or more compounds selected from the compounds represented by the general formula (I-1), and is selected from the compounds represented by the general formula (I-2). Those containing one or more compounds. 3. The liquid crystal composition has a dielectric anisotropy of −15 to 40, a birefringence of 0.02 to 0.40, and a nematic phase at 50 ° C. to 180 ° C.-isotropic. The nematic liquid crystal composition according to claim 1, wherein the nematic liquid crystal composition has a liquid phase transition temperature of −200 ° C. to 0 ° C., a smectic phase, or a glass phase-nematic phase transition temperature. 4. 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. 5. An active matrix and a twisted liquid crystal using the nematic liquid crystal composition according to claim 1.
Nematic or super twisted nematic liquid crystal display. 6. 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. 7. 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 according to the above.