JP2881079B2 - Liquid crystal composition, liquid crystal element using the same, display method and display device thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystal composition, a liquid crystal device using the same, a display method therefor, and a display device using the liquid crystal device for display.

[0002]

2. Description of the Related Art Conventionally, liquid crystals have been applied in various fields as electro-optical elements. Most liquid crystal elements currently in practical use are, for example, M. Sch (M. Sch.
adt) and W. Helfrich
ch), “Applied Physics Letters”
("Applied Physics Letter
s ") Vo.18, No.4 (1971.2.15)
P. 127-128 "Voltage Depend
ent Optical Activity of a
Twisted Nematic Liquid Cr
ystal ”, the TN (Twisted Nem
(atic) type liquid crystal.

[0003] These are based on the dielectric alignment effect of liquid crystal, and use the effect that the average molecular axis direction is directed to a specific direction by an applied electric field due to the dielectric anisotropy of liquid crystal molecules. The limit on the optical response speed of these devices is said to be milliseconds, which is too slow for many applications.

On the other hand, in application to a large flat display, driving by a simple matrix system is the most influential in consideration of price, productivity and the like. In the simple matrix system, an electrode configuration in which a scanning electrode group and a signal electrode group are configured in a matrix is employed. To drive the scanning electrode group, an address signal is sequentially and selectively applied to the scanning electrode group, and the signal electrode group is applied. Adopts a time-division driving method in which a predetermined information signal is selectively applied in parallel in synchronization with an address signal.

However, when the above-mentioned TN type liquid crystal is adopted as the element of such a driving system, the scanning electrode is selected and the signal electrode is not selected, or the scanning electrode is not selected and the signal electrode is selected. A finite electric field is also applied to the so-called “half-selected point”.

If the difference between the voltage applied to the selected point and the voltage applied to the half-selected point is sufficiently large and the voltage threshold required for aligning the liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage value, The display element works normally,
When the number of scanning lines (N) is increased, the entire screen (1
The time (duty ratio) during which an effective electric field is applied to one selected point while scanning a frame (frame) is reduced at a rate of 1 / N.

For this reason, the voltage difference as an effective value between the selected point and the non-selected point when the repetitive scanning is performed is as follows.
As the number of scanning lines increases, the number of scanning lines decreases, and as a result, the image contrast is reduced and crosstalk is inevitable.

Such a phenomenon is caused by a liquid crystal having no bistability (a stable state in which liquid crystal molecules are horizontally aligned with respect to an electrode surface, and a vertical state only while an electric field is effectively applied. This is essentially an unavoidable problem that occurs when driving (ie, repeating scanning) using the time accumulation effect.

In order to improve this point, a voltage averaging method,
The frequency driving method and the multi-matrix method have already been proposed, but none of these methods are sufficient, and the increase in the screen size and the density of the display element has ceased because the number of scanning lines cannot be sufficiently increased. That is the current situation.

[0010] As an improvement over the disadvantages of the conventional liquid crystal device, the use of a liquid crystal device having bistability has been improved by Clark and Lagerwell.
11) (JP-A-56-10721).
No. 6, US Pat. No. 4,367,924, etc.). As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral smectic C phase (SmC ^* phase) or an H phase (SmH ^* phase) is generally used.

This ferroelectric liquid crystal has a bistable state consisting of a first optically stable state and a second optically stable state with respect to an electric field. Therefore, the optical modulation used in the above-mentioned TN-type liquid crystal. Unlike the element, for example, the liquid crystal is oriented in a first optically stable state with respect to one electric field vector, and the liquid crystal is oriented in a second optically stable state with respect to the other electric field vector. In addition, this type of liquid crystal has a property (bistability) that takes one of the above two stable states in response to an applied electric field and maintains the state when no electric field is applied.

In addition to the characteristic having bistability as described above, the ferroelectric liquid crystal has an excellent characteristic of high-speed response. This is because the spontaneous polarization of the ferroelectric liquid crystal and the applied electric field act directly to induce a transition of the alignment state.
It is 3 to 4 orders of magnitude faster than the response speed due to the effects of dielectric anisotropy and electric field.

As described above, the ferroelectric liquid crystal potentially has extremely excellent characteristics, and by utilizing such characteristics, many of the problems of the conventional TN-type device described above can be solved. A fairly substantial improvement is obtained. In particular, application to high-speed optical shutters and high-density, large-screen displays is expected. For this reason, liquid crystal materials with ferroelectricity have been widely studied, but the ferroelectric liquid crystal materials developed to date have sufficient characteristics to be used in liquid crystal devices, including low-temperature operation characteristics and high-speed response. It is hard to say that it has.

The following equation [1] is provided between the response time τ and the magnitude Ps of the spontaneous polarization and the viscosity η.

[0015]

Τ = η / (Ps · E) [1] (where E is an applied electric field).

Therefore, to increase the response speed, there are (a) increasing the magnitude Ps of spontaneous polarization, (a) decreasing the viscosity η, and (c) increasing the applied electric field E. However, the applied electric field has an upper limit because it is driven by an IC or the like, and it is desirable that the applied electric field be as low as possible. Therefore, it is actually necessary to reduce the viscosity η or increase the value of the magnitude Ps of the spontaneous polarization.

In general, in a ferroelectric chiral smectic liquid crystal compound having a large spontaneous polarization, the internal electric field of a cell caused by the spontaneous polarization is large, and there is a tendency that restrictions on a device configuration capable of taking a bistable state are increased. Further, even if the spontaneous polarization is increased unnecessarily, the viscosity tends to increase with the spontaneous polarization, and as a result, the response speed may not be so high.

When the operating temperature range of the actual display is, for example, about 5 to 40 ° C., the change of the response speed is generally about 20 times, which exceeds the limit of adjustment by the drive voltage and the frequency. It is the current situation.

As described above, in order to put a ferroelectric liquid crystal device to practical use, a liquid crystal composition having a low viscosity, a high-speed response, and a chiral smectic phase with a small temperature dependence of the response speed is required. Required.

Further, in order to realize a display device having excellent image quality, the alignment characteristics of the liquid crystal material used are also important issues. For example, a liquid crystal material exhibiting an SmC ^* phase has a zigzag defect or a gap holding material in a liquid crystal cell (for example,
There is a feature that alignment defects easily occur around the spacer beads).

Furthermore, alignment defects easily occur due to the difference in the rubbing state of the alignment film caused by the unevenness of the alignment film surface derived from the liquid crystal element components.

In many cases, the SmC ^* phase state is a phase state passing through several phase transitions from the isotropic phase state, and is in a state closer to the crystalline phase as compared with the nematic phase. The present inventors speculate that this is also caused.

A serious problem is that these alignment defects reduce the bistability, which is a characteristic of the SmC ^* liquid crystal material, and further reduce the image quality, the contrast, and the crosstalk. It is a factor that causes.

[0024]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the liquid crystal element and provides a ferroelectric liquid crystal element which is expected to be applied to high-speed optical shutters and high-density, large-screen displays. In order to achieve this, a simple rubbing process easily aligns, shows uniform monodomain alignment without defects, and has a large spontaneous polarization and a high response speed, especially a ferroelectric chiral smectic phase. It is an object of the present invention to provide a liquid crystal composition, a liquid crystal element using the liquid crystal composition, and a display method and a display device using the liquid crystal composition.

[0025]

That is, the present invention provides a compound represented by the following general formula (I):

[0026]

Embedded image

(Wherein R ₁ and R _{2 each} have 1 to 1 carbon atoms)
It represents 18 linear or branched alkyl groups. X ₁
Is a single bond, -O-, -CO-, -COO-, -OOC
- indicates, _{X 2} is -OCH ₂ -, - OOC- shows a. A ₁ , A ₂ , A ₃ are

[0028]

Embedded image Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. )

At least one of the optically active compounds represented by
Provided are a liquid crystal composition comprising a seed, a liquid crystal element comprising the liquid crystal composition disposed between a pair of electrode substrates, a display method thereof, and a display device. .

Among the optically active compounds represented by formula (I), a particularly preferred compound is (Ia)
To (Ih).

[0031]

Embedded image

(Wherein R ₁ and R ₂ have 1 to 1 carbon atoms)
It represents 18 linear or branched alkyl groups. X ₁
Is a single bond, -O-, -CO-, -COO-, -OOC
Indicates-. Y ₁ and Y ₂ represent H or halogen.
* Indicates optical activity. Further, more preferred compounds among the optically active compounds represented by the general formula (I) are (Ica) to (If)
b).

[0033]

Embedded image

(Wherein R ₁ and R ₂ have 1 to 1 carbon atoms)
It represents 18 linear or branched alkyl groups. * Indicates optical activity. )

Further, R ₁ and R _{2 in the} general formula (I)
Is preferably a linear alkyl group having 3 to 12 carbon atoms.

A preferred composition is an optically active compound represented by the following general formula (I):

[0037]

Embedded image

(Wherein R ₁ and R _{2 each} have 1 to 1 carbon atoms)
It represents 18 linear or branched alkyl groups. X ₁
Is a single bond, -O-, -CO-, -COO-, -OOC
- indicates, _{X 2} is -OCH ₂ -, - OOC- shows a. A ₁ , A ₂ , A ₃ are

[0039]

Embedded image

Is shown. Y ₁ and Y ₂ represent H or halogen. m and n are 0 or 1. * Indicates optical activity. ) And a liquid crystal compound represented by the following general formula (II)

[0041]

Embedded image

(Wherein R ₃ and R _{4 each} have 1 to 1 carbon atoms)
8 represents a linear or branched alkyl group. X ₃
Represents a single bond, -O-, -OOC-. p is 0 or 1. A ₄ is

[0043]

Embedded image Is shown. ) Is a liquid crystal composition containing at least one of the above.

More preferably, an optically active compound represented by the following general formula (I)

[0045]

Embedded image

(Wherein R ₁ and R _{2 each} have 1 to 1 carbon atoms)
It represents 18 linear or branched alkyl groups. X ₁
Is a single bond, -O-, -CO-, -COO-, -OOC
- indicates, _{X 2} is -OCH ₂ -, - OOC- shows a. A ₁ , A ₂ , A ₃ are

[0047]

Embedded image Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. ) And a liquid crystal compound represented by the following general formula (II)

[0048]

Embedded image

(Wherein R ₃ and R _{4 each} have 1 to 1 carbon atoms)
8 represents a linear or branched alkyl group. X ₃
Represents a single bond, -O-, -OOC-. p is 0 or 1. A ₄ is

[0050]

Embedded image Is shown. ) And at least one of the following general formula (III)
Optically active compound represented by a)

[0051]

Embedded image

(Wherein, R ₅ represents a linear or branched alkyl group having 1 to 18 carbon atoms. R ₆ represents a linear alkyl group having 1 to 16 carbon atoms. X ₄ Is
Shows a single bond and -COO-. A ₅ is

[0053]

Embedded image Is shown. * Indicates optical activity. ) Is a liquid crystal composition containing at least one of the above.

Further, a liquid crystal composition containing a compound in which X ₂ is —OCH ₂ — among the optically active compounds represented by the general formula (I) is more preferable.

Next, a general method for synthesizing the optically active compound represented by the general formula (I) will be described.

[0056]

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Further, the optically active compound represented by the general formula (I) is preferably applied to an application (Japanese Patent Application No. Hei.
No. 57260), and is prepared from an optically active alkyl 4,4,4-trifluoro-3- (4-hydroxyphenyl) butanoate represented by the following general formula (3).

[0058]

Embedded image (In the formula, R represents a linear or branched alkyl group having 1 to 18 carbon atoms.)

Representative examples of the synthesis of the optically active compound represented by formula (I) are shown below. Synthesis Example 1 Optically active 3- (4-hexyloxyphenyl) -4,
Preparation of 4- (5-decylpyrimidin-2-yl) phenyl 4,4-trifluorobutanoate (Exemplified Compound 106) Optically active 3- (4-hexyloxyphenyl) -4,4,4- Trifluorobutanoic acid 4- (5
-Decylpyrimidin-2-yl) phenyl was prepared.

[0060]

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Step 1) Production of optically active hexyl 3- (4-hexyloxyphenyl) -4,4,4-trifluorobutanoate 97 mg of sodium hydride (2.4 mm
ol) and 3 ml of dry dimethylformamide (DMF), into which optically active 3- (4-hydroxyphenyl)
190 mg of -4,4,4-trifluorobutanoic acid (0.
A mixture of 81 mmol) and 4 ml of dry DMF was added.
Further, a mixed solution of 516 mg (2.4 mmol) of hexyl iodide and 2 ml of dry DMF was added, and the mixture was heated and stirred at 80 ° C. for 75 minutes.

After completion of the reaction, DMF was distilled off under reduced pressure, diluted hydrochloric acid was added, and the mixture was extracted with ether. The extract was washed with a saturated aqueous solution of sodium hydrogencarbonate and water, and dried over anhydrous sodium sulfate. After evaporating the solvent, the residue was purified by thin-layer chromatography, and 275 mg of the desired product (0.684 mm
ol).

[Α] _D ²³ -31.6 °, [α] ₄₃₅ ²³ -6
7.0 ° (c1.668, EtOH)

Step 2) Production of optically active 3- (4-hexyloxyphenyl) -4,4,4-trifluorobutanoic acid -Hexyl trifluorobutanoate 2
75 mg (0.684 mmol) and 99% ethanol 2
ml, 90 mg of potassium hydroxide and 1 ml of water were added and refluxed for 4 hours. After completion of the reaction, ether and water were added, and the mixture was extracted with an aqueous sodium hydroxide solution. Hydrochloric acid to extract 1
And the released carboxylic acid was extracted with ether. After the obtained extract was washed with water, anhydrous sodium sulfate was added thereto and dried. After distilling off the solvent, distillation under reduced pressure
9 mg (0.594 mmol) were obtained.

Yield 87%, b. p. 185 ° C / 0.3t
orr, [α] _D ²¹ −35.9 °, [α] ₄₃₅
^{21 -77.2 ° (c 0.912, CHCl} 3)

Step 3) Optically active 3- (4-hexyloxyphenyl) -4,4,4-trifluorobutanoic acid 4-
Production of (5-decylpyrimidin-2-yl) phenyl 99 mg of optically active 3- (4-hexyloxyphenyl) -4,4,4-trifluorobutanoic acid was placed in an eggplant flask.
(0.31 mmol) and 4- (5-decylpyrimidine-
2-yl) phenol 98 mg (0.31 mmol),
19 mg of dimethylaminopyridine (0.16 mmol
1) 2 ml of dry dichloromethane was added, and the mixture was stirred at room temperature for 30 minutes. 192 mg (0.932 mmol) of dicyclohexylcarbodiimide (DCC) and 1 ml of dry dichloromethane were added thereto, and the mixture was further stirred at room temperature for 3 hours. After the reaction, the crystals were removed by filtration. The filtrate was concentrated and purified by thin-layer column chromatography to obtain 162 mg (0.265 mmol) of the desired product.

Yield 85%, mp. ^{_{46 ℃ [α] D 24 -78.7}} °, [α] 435 24 -1
84 ° (c 0.715, CHCl ₃ )

Synthesis Example 2 Optically active 1,1,1-trifluoro-2- (4-hexyloxyphenyl) -4- {4- (5-decylpyrimidin-2-yl) phenoxy} butane (Exemplified Compound 5)
Production of 3) Optically active 1,1,1-trifluoro-
2- (4-hexyloxyphenyl) -4- {4- (5
-Decylpyrimidin-2-yl) phenoxydibutane was prepared.

[0069]

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Step 1) Production of optically active 3- (4-hexyloxyphenyl) -4,4,4-trifluorobutanol
mg (2.15 mmol) and dry ether. In addition, optically active 3- (4-hexyloxyphenyl)-
Hexyl 4,4,4-trifluorobutanoate 288mg
A mixture of (0.716 mmol) and 4 ml of dry ether was added dropwise. After heating under reflux for 4 hours, dilute hydrochloric acid was added, and the mixture was extracted with ether. After adding anhydrous sodium sulfate and drying, the solvent was distilled off and distillation under reduced pressure was performed to obtain 208 mg of the target product.
(0.684 mmol) was obtained.

Yield 96%, bp 135 ° C./0.15
torr [α] _D ²⁷ + 45.3 °, [α] ₄₃₅ ²⁶ +9
2.4 ° (c 0.900, CHCl ₃ )

Step 2) Production of optically active 4- (4-hexyloxyphenyl) -4,4,4-trifluorobutyl 4-toluenesulfonate
mg and 1 ml of dry dichloromethane.
208 mg of (4-hexyloxyphenyl) -4,4,4-trifluorobutanol and 2 m of dry dichloromethane
1 of the mixed solution, and further triethylenediamine 80 mg
(0.714 mmol) and 1 ml of dry dichloromethane were added. Stirred in an ice bath for 24 hours. After completion of the reaction, diluted hydrochloric acid was added, and the mixture was extracted with ether. After drying by adding anhydrous sodium sulfate, the solvent was distilled off, and the residue was purified by thin-layer chromatography to obtain 247 mg (0.53 mg) of the desired product.
9 mmol).

[Α] _D ²³ -40.5 °, [α] ₄₃₅ ²³ +8
1.7 ° (c 0.878, CHCl ₃ )

Step 3) Optically active 1,1,1-trifluoro-2- (4-hexyloxyphenyl) -4- {4-
Preparation of (5-decylpyrimidin-2-yl) phenoxydibutane 60% -Sodium hydride 13 mg in an eggplant flask
(0.33 mmol) and 1 ml of dry DMF were added, and a mixed solution of 82 mg (0.263 mmol) of 4- (5-decylpyrimidin-2-yl) phenol and 2 ml of dry DMF was added thereto, followed by stirring at room temperature for 10 minutes. In addition, 120 mg of optically active 4- (4-hexyloxyphenyl) -4,4,4-trifluorobutyl 4-toluenesulfonate
(0.262 mmol) and 2 ml of dry DMF were added, and the mixture was stirred at room temperature for 6 hours and at 50 ° C. for 1 hour.

After completion of the reaction, DMF was distilled off under reduced pressure, diluted hydrochloric acid was added, and the mixture was extracted with ether. The extract was washed with a saturated aqueous solution of sodium hydrogencarbonate and water, and dried over anhydrous sodium sulfate. After distilling off the solvent, the residue was purified by thin-layer chromatography to obtain 141 mg of the desired product (0.235 mmol).
1) was obtained.

Yield 90%, mp. 56 ° C. [α] _D ²⁹ + 112 °, [α] ₄₃₅ ²⁸ +26
5 ° (c 0.702, CHCl ₃ )

Next, specific examples of the optically active compound represented by the general formula (I) are shown below.

[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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[0094]

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[0095]

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The liquid crystal composition of the present invention can be obtained by mixing at least one of the optically active compounds represented by the general formula (I) and one or more other liquid crystal compounds at an appropriate ratio. Further, the liquid crystal composition according to the present invention is preferably a ferroelectric liquid crystal composition, particularly a ferroelectric chiral smectic liquid crystal composition.

Other liquid crystal compounds used in the present invention are shown by the following formulas (III) to (XIII).

[0098]

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As a preferred compound of the formula (III), (I
IIa) to (IIIe).

[0100]

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[0101]

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As a preferred compound of the formula (IV), (IV)
a) to (IVc).

[0103]

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[0104]

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As a preferred compound of the formula (V), (V
a) and (Vb).

[0106]

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[0107]

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As a preferred compound of the formula (VI), (VI)
a) to (VIf).

[0109]

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Here, R ₁ ′ and R ₂ ′ are those having 1 to 1 carbon atoms.
8 is a linear or branched alkyl group, wherein one or two or more non-adjacent —CH ₂ — groups in the alkyl group may be replaced by —CH halogen—. Further X _1, X ₂ directly bonded to -CH ₂ - one except group or not adjacent two or more -CH ₂ - groups

[0111]

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It may be replaced by

Provided that R ₁ ′ or R ₂ ′ is one CH ₂ group

[0114]

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In the case of alkyl halide substituted with -CH halogen-, R ₁ 'or R ₂ ' is not bonded to the ring by a single bond.

R ₁ ′ and R ₂ ′ are preferably: i) a linear alkyl group having 1 to 15 carbon atoms

[0117]

Embedded image p: 0 to 5 q: 2 to 11 Integer Optically active

[0118]

Embedded image r: 0 to 6 s: 0, 1 t: 1 to 14 Integer Optically active

[0119]

Embedded image u: 0, 1 v: 1 to 16 integer

[0120]

Embedded image w: 1 to 15 integers may be optically active

[0121]

Embedded image x: 0 to 2 y: 1 to 15 Integer

[0122]

Embedded image z: 1 to 15 integer

[0123]

Embedded image A: 0 to 2 B: 1 to 15 Integer Optically active

[0124]

Embedded image C: 0-2 D: 1-15 Integer Optically active X) H XI) F

More preferred compounds of (IIIa) to (IIId) include (IIIaa) to (IIIdc).

[0126]

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[0127]

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More preferable compounds of (IVa) to (IVc) include (IVaa) to (IVcb).

[0129]

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More preferable compounds of (Va) to (Vd) include (Vaa) to (Vdf).

[0131]

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[0132]

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More preferable compounds of (VIa) to (VIf) include (VIaa) to (VIfa).

[0134]

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[0135]

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[0136]

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More preferred compounds of (VII) include (VIIa) and (VIIb).

[0138]

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Preferred compounds of the formula (VIII) include (VIIIa) and (VIIIb).

[0140]

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More preferred compounds of (VIIIb) include (VIIIba) and (VIIIbb).

[0142]

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Here, R ₃ ′ and R ₄ ′ are those having 1 to 1 carbon atoms.
8 linear or branched alkyl groups, wherein one or two or more non-adjacent —CH ₂ groups
May be replaced by -CH halogen-. Further X _1, X ₂ directly bonded to -CH ₂ - one except group or not adjacent two or more -CH ₂ - groups

[0144]

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It may be replaced by

However, when R ₃ ′ or R ₄ ′ is an alkyl halide in which one CH ₂ group is replaced by —CH halogen —, R ₃ ′ or R ₄ ′ is a single bond to the ring. do not do.

Further, R ₃ ′ and R ₄ ′ are preferably: i) a linear alkyl group having 1 to 15 carbon atoms

[0148]

Embedded image p: 0 to 5 q: 2 to 11 Integer Optically active

[0149]

Embedded image r: 0 to 6 s: 0, 1 t: 1 to 14 Integer Optically active

[0150]

Embedded image u: 0, 1 v: 1 to 16 integer

[0151]

Embedded image w: 1 to 15 integers may be optically active

[0152]

Embedded image A: 0 to 2 B: 1 to 15 Integer Optically active

[0153]

Embedded image C: 0 to 2 D: 1 to 15 Integer Optically active

[0154]

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[0155]

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[0156]

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[0157]

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[0158]

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As a preferred compound of the formula (IX), (IX)
a) to (IXc).

[0160]

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As a preferred compound of the formula (X), (X
a) and (Xb).

[0162]

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As a preferred compound of the formula (XII), (X
IIa) to (XIId).

[0164]

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Preferred compounds of the formula (XIII) include (XIIIa) to (XIIIe).

[0166]

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More preferred compounds of (IXa) to (IXc) include (IXaa) to (IXcc).

[0168]

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Further preferred compounds of (Xa) and (Xb) include (Xaa) to (Xbb).

[0170]

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As a more preferred compound (XI), (X
Ia) to (XIg).

[0172]

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More preferable compounds of (XIIa) to (XIIf) include (XIIaa) to (XIIfc).

[0174]

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[0175]

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Here, R ₅ ′ and R ₆ ′ are those having 1 to 1 carbon atoms.
8 is a linear or branched alkyl group, excluding -CH ₂ -groups directly bonded to X ₁ and X ₂ in the alkyl group.
Two or more non-adjacent —CH ₂ — groups

[0177]

Embedded image May be replaced by

Further, R ₅ ′ and R ₆ ′ are preferably: i) a linear alkyl group having 1 to 15 carbon atoms

[0179]

Embedded image p: 0 to 5 q: 2 to 11 Integer Optically active

[0180]

Embedded image r: 0 to 6 s: 0, 1 t: 1 to 14 Integer Optically active

[0181]

Embedded image w: 1 to 15 integers may be optically active

[0182]

Embedded image A: 0 to 2 B: 1 to 15 Integer Optically active

[0183]

Embedded image C: 0 to 2 D: 1 to 15 Integer Optically active

When the optically active compound represented by the general formula (I) in the present invention is mixed with one or more of the above-mentioned liquid crystal compounds or liquid crystal compositions, the liquid crystal composition obtained by mixing the compounds is mixed in the liquid crystal composition. The proportion of the optically active compound represented by the general formula (I) occupying is desirably 1% by weight to 80% by weight, preferably 1% by weight to 60% by weight, and more preferably 1% by weight to 40% by weight.

When two or more optically active compounds represented by the general formula (I) are used, two or more optically active compounds represented by the general formula (I) occupy in the liquid crystal composition obtained by mixing. Is preferably 1 to 80% by weight, and more preferably 1 to 60% by weight.

Next, the liquid crystal device of the present invention has the above-described liquid crystal composition disposed between a pair of electrode substrates. In particular, the ferroelectric liquid crystal layer in the ferroelectric liquid crystal device is as described above. It is preferable to heat the ferroelectric liquid crystal composition prepared as described above to a temperature of an isotropic liquid in a vacuum, enclose it in an element cell, gradually cool to form a liquid crystal layer, and return to normal pressure.

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal device having a chiral smectic liquid crystal layer for explaining the structure of a liquid crystal device utilizing ferroelectricity.

Referring to FIG. 1, in the liquid crystal device, a liquid crystal layer 1 exhibiting a chiral smectic phase is arranged between a pair of glass substrates 2 provided with a transparent electrode 3 and an insulating alignment control layer 4, respectively. The thickness is set by a spacer 5, and a connection is made between a pair of transparent electrodes 3 via a lead wire 6 so that a voltage can be applied from a power supply 7. Also, a pair of substrates 2
Is sandwiched between a pair of crossed Nicol polarizing plates 8, and a light source 9 is disposed outside one of the crossed Nicol polarizing plates.

That is, the two glass substrates 2 are respectively provided with In ₂ O ₃ , SnO ₂ or ITO (indium tin oxide; indium tin oxide).
xide) or the like, and is covered with a transparent electrode 3 made of a thin film. A thin film of a polymer such as polyimide is rubbed thereon with a gauze, an acetate flocking cloth or the like, and an insulating alignment control layer 4 for arranging liquid crystals in the rubbing direction is formed.

As the insulating orientation control layer 4, for example, silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen, silicon oxide, boron nitride, and boron nitride containing hydrogen are used. Product, cerium oxide, aluminum oxide, zirconium oxide, an inorganic insulating layer such as titanium oxide or magnesium fluoride, and polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylene, polyester , Polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate,
It may have a two-layer structure in which an organic insulating material such as polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin, and photoresist resin is formed. The orientation control layer may be a single layer.

If the insulating orientation control layer is inorganic, it can be formed by vapor deposition or the like. If organic, it can be formed by dissolving an organic insulating material or its precursor solution (0.1 to 20% in a solvent).
% By weight, preferably 0.2 to 10% by weight) by a spinner coating method, a dip coating method, a screen printing method, a spray coating method, a roll coating method or the like, and under predetermined curing conditions (for example, under heating). ) Can be formed by curing.

The thickness of the insulating orientation control layer 4 is usually from 10 to
1 μm, preferably 10 ° to 3000 °, more preferably 10 ° to 1000 ° is suitable.

The two glass substrates 2 are kept at an arbitrary interval by the spacer 5. For example, there is a method in which silica beads and alumina beads having a predetermined diameter are sandwiched between two glass substrates as spacers, and the periphery is sealed using a sealing material, for example, an epoxy-based adhesive. Others
A polymer film or glass fiber may be used as the spacer. Liquid crystal exhibiting a chiral smectic phase is sealed between the two glass substrates. Liquid crystal layer 1
Is generally 0.5 to 20 μm, preferably 1 to 5 μm
It is set to the thickness of.

The transparent electrode 3 is connected to an external power source 7 by a lead wire. Outside the glass substrate 2, a pair of polarizing plates 8 having their polarization axes in, for example, a crossed Nicols state are bonded together. The example of FIG. 1 is of a transmission type and includes a light source 9.

FIG. 2 schematically illustrates an example of a cell for explaining the operation of a liquid crystal element utilizing ferroelectricity.
21a and 21b are In ₂ O ₃ and SnO ₂ , respectively.
Alternatively, ITO (indium tin oxide; I
a substrate (glass plate) covered with a transparent electrode made of a thin film such as ndium tin oxide (Sn), in which the liquid crystal molecule layer 22 is oriented so as to be perpendicular to the glass surface.
Liquid crystal of mC ^* phase or SmH ^* phase is sealed.
A bold line 23 represents a liquid crystal molecule, and the liquid crystal molecule 23 has a dipole moment (P⊥) 24 in a direction perpendicular to the molecule. When a voltage equal to or higher than a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is released, and the dipole moment (P⊥)
The liquid crystal molecules 23 can change the alignment direction so that all of them 24 face the electric field direction. The liquid crystal molecules 23 have an elongated shape and exhibit refractive index anisotropy in the major axis direction and the minor axis direction. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the voltage application polarity It can be easily understood that the liquid crystal optical modulation element whose optical characteristics change depending on the liquid crystal.

The liquid crystal cell preferably used in the optical modulation element of the present invention has a sufficiently small thickness (for example, 1
0 μm or less). As shown in FIG. 3, as the liquid crystal layer becomes thinner, the helical structure of the liquid crystal molecules is released even when no electric field is applied, and the dipole moment Pa or Pb thereof is directed upward (34a) or downward (34b). Take either of the states. When an electric field Ea or Eb having a different polarity or more than a certain threshold value is applied to such a cell by the voltage applying means 31a and 31b as shown in FIG. 3, the dipole moment corresponds to the electric field vector of the electric field Ea or Eb. The liquid crystal molecules are turned to the upward direction 34a or the downward direction 34b, and accordingly, the liquid crystal molecules are in the first stable state 3
3a or the second stable state 33b.

As described above, there are two advantages of using such a ferroelectric liquid crystal element as an optical modulation element. The first is that the response speed is extremely fast, and the second is that the orientation of the liquid crystal molecules has bistability. The second point will be further described with reference to, for example, FIG.
When a is applied, the liquid crystal molecules are oriented to the first stable state 33a, which is stable even when the electric field is turned off. Further, when an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to the second stable state 33b and change the direction of the molecules, but remain in this state even after the electric field is cut off. As long as the applied electric field Ea or Eb does not exceed a certain threshold value, the respective alignment states are also maintained in the previous state.

By using the liquid crystal element of the present invention in a display panel section and employing a data synchronization format of image information having scanning line address information and a SYNC signal shown in FIGS. To achieve.

In the figure, reference numerals are as follows. DESCRIPTION OF SYMBOLS 101 Ferroelectric liquid crystal display device 102 Graphics controller 103 Display panel 104 Scan line drive circuit 105 Information line drive circuit 106 Decoder 107 Scan signal generation circuit 108 Shift register 109 Line memory 110 Information signal generation circuit 111 Drive control circuit 112 GCPU 113 Host CPU 114 VRAM

By using the liquid crystal element of the present invention in a display panel section and using a data synchronization format of image information having scanning line address information and a SYNC signal shown in FIGS. 4 and 5, a liquid crystal display device is provided. To achieve.

The generation of image information is performed by the graphics controller 102 of the main unit, and is transferred to the display panel 103 according to the signal transfer means shown in FIGS. The graphics controller 102 has a CP
U (central processing unit, hereinafter abbreviated as GCPU 112) and VRAM (memory for storing image information) 114 serve as a nucleus for managing and communicating image information between the host CPU 113 and the liquid crystal display device 101. The method is mainly realized on the graphics controller 102. Note that a light source is disposed on the back surface of the display panel.

[0202]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

Example 1 A liquid crystal composition A was prepared by mixing the following compounds in the following parts by weight.

[0204]

Embedded image 3 shows a phase transition temperature of a liquid crystal composition A.

[0205]

(Equation 2) Further, the liquid crystal composition A was mixed with Exemplified Compound 53 in the following parts by weight to prepare a liquid crystal composition B.

[0206]

Embedded image This indicates the following phase transition temperature:

[0207]

(Equation 3)

Examples 2 to 4 In place of Exemplified Compound 53 used in Example 1, the following compounds were added at 10 wt% to obtain respective liquid crystal compositions. The phase transition temperatures of these compositions are shown below.

[0209]

(Equation 4) Example 5 Two glass plates having a thickness of 0.7 mm were prepared, an ITO film was formed on each of the glass plates, and a voltage application electrode was formed.
Further, SiO ₂ was deposited thereon to form an insulating layer. Silane coupling agent [KB manufactured by Shin-Etsu Chemical Co., Ltd.]
M-602] A 0.2% isopropyl alcohol solution was rotated at 2000 rpm. p. m for 15 seconds,
Surface treatment was applied. Thereafter, a heat drying treatment was performed at 120 ° C. for 20 minutes.

[0210] A polyimide resin precursor [Toray Co., Ltd. SP-
510] 1.5% dimethylacetamide solution at 2000 rpm. p. m for 15 seconds.
After the film formation, a heat condensation baking treatment was performed at 300 ° C. for 60 minutes. At this time, the thickness of the coating film was about 250 °.

The baked film was subjected to a rubbing treatment with an acetate flocking cloth, then washed with an isopropyl alcohol solution, and sprayed with alumina beads having an average particle size of 2 μm on one of the glass plates. The glass plates were stuck together using an adhesive sealant [Rixson Bond (Chisso Corporation)] so that the axes were parallel to each other, and heated and dried at 100 ° C. for 60 minutes to form a cell.

The liquid crystal composition B mixed in Example 1 was injected into this cell in an isotropic liquid state, and was slowly cooled from the isotropic phase to 25 ° C. at a rate of 20 ° C./h to obtain a ferroelectric liquid crystal element. Created. The cell thickness of this cell was about 2 μm when measured with a Berek phase plate.

Using this ferroelectric liquid crystal element, the magnitude Ps of spontaneous polarization and the peak-to-peak voltage Vpp = 20
By applying a voltage of V, an optical response (a change in transmitted light amount of 10% to 90%) under crossed Nicols was detected, and a response speed (hereinafter referred to as an optical response speed) was measured. The results are shown below.

[0214]

Equation 5] Measurement temperature (℃) Ps (nC / cm 2) the optical response speed (μsec) 25 -7.5 92 35 -5.6 72 45 -2.5 58

Examples 6 to 8 The magnitude of spontaneous polarization and the optical response speed were measured in the same manner as in Example 5 except that the liquid crystal compositions prepared in Examples 2 to 4 were used. Table 1 shows the results.

[0216]

[Table 1]

Example 9 A liquid crystal composition F was prepared by mixing the following compounds in the following parts by weight.

[0218]

Embedded image 3 shows a phase transition temperature of a liquid crystal composition F.

[0219]

(Equation 6) Further, Exemplified Compound 54 was mixed with the liquid crystal composition F in the following parts by weight to prepare a liquid crystal composition G.

[0220]

Embedded image This indicates the following phase transition temperature:

[0221]

(Equation 7) Next, the optical response speed at 30 ° C. was measured in the same manner as in Example 5 except that the liquid crystal compositions F and G were used. The results are shown.

[0222]

## EQU8 ## Liquid crystal composition Optical response speed (μsec)

Examples 10 to 14 In place of the exemplified compound 54 used in the ninth embodiment, 3 parts by weight of the following exemplified compounds were added to obtain respective liquid crystal compositions. The optical response speed at 30 ° C. was measured in the same manner as in Example 5 except that this liquid crystal composition was used. The results are shown below.

[0224]

Embedded image

As apparent from the results of Examples 9 to 14, the compositions G, H, I, J, K and L containing the optically active compound represented by the general formula (I) of the present invention. It can be seen that the optical response speed is higher than that of the composition F containing no.

Example 15 The following compounds were mixed in the following parts by weight to prepare a liquid crystal composition M.

[0227]

Embedded image

[0228]

Embedded image

Further, each of the following compounds was mixed with the liquid crystal composition M in the following parts by weight to prepare a liquid crystal composition N.

[0230]

Embedded image Next, a ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that these liquid crystal compositions M and N were used, and the orientation was observed. The results are shown.

[0231]

９ 9 Liquid crystal composition Orientation M Much zigzag defects N Uniform monodomain alignment state

Example 16 A liquid crystal composition O was prepared by mixing the following compounds in place of the exemplified compounds used in Example 15 in the indicated parts by weight.

[0233]

Embedded image

Next, a ferroelectric liquid crystal device was prepared in exactly the same manner as in Example 5 except that the liquid crystal composition O was used, and the orientation was observed. As a result, a uniform monodomain alignment state with few zigzag defects was observed. Met.

Example 17 A liquid crystal composition P was prepared by mixing the following compounds in place of the exemplified compounds used in Example 15 in the indicated parts by weight.

[0236]

Embedded image

Next, a ferroelectric liquid crystal device was prepared in exactly the same manner as in Example 5 except that this liquid crystal composition P was used, and the alignment was observed. As a result, a uniform monodomain alignment state with few zigzag defects was obtained. Met.

As is apparent from the results of Examples 15 to 17, the liquid crystal compositions N, O, and P of the present invention containing the optically active compound represented by the general formula (I) were obtained from the composition M containing no such compound.
As compared with the above, the liquid crystal composition exhibited a uniform monodomain alignment with less zigzag defects and was found to have a good alignment.

[0239]

According to the liquid crystal composition of the present invention, a favorable effect can be obtained in which a simple rubbing treatment facilitates alignment and exhibits uniform monodomain alignment without defects.

Further, a ferroelectric liquid crystal device using the liquid crystal composition of the present invention can be a liquid crystal device having good switching characteristics and high response speed. Note that a display device in which the liquid crystal element of the present invention is combined with a light source, a driving circuit, and the like as a display element is a favorable device.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of a liquid crystal element using a liquid crystal exhibiting a chiral smectic phase.

FIG. 2 is a perspective view schematically showing an example of an element cell for explaining the operation of a liquid crystal element utilizing the ferroelectricity of liquid crystal.

FIG. 3 is a perspective view schematically showing an example of an element cell for explaining the operation of a liquid crystal element utilizing the ferroelectricity of liquid crystal.

FIG. 4 is a block diagram showing a liquid crystal display device having a liquid crystal element utilizing ferroelectricity and a graphics controller.

FIG. 5 is a timing chart of image information communication between a liquid crystal display device and a graphics controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal layer having a chiral smectic phase 2 Glass substrate 3 Transparent electrode 4 Insulating alignment control layer 5 Spacer 6 Lead wire 7 Power supply 8 Polarizing plate 9 Light source I ₀ Incident light I Transmitted light 21a Substrate 21b Substrate 22 Liquid crystal having a chiral smectic phase Layer 23 Liquid crystal molecule 24 Dipole moment (P⊥) 31a Voltage applying means 31b Voltage applying means 33a First stable state 33b Second stable state 34a Upward dipole moment 34b Downward dipole moment Ea Upward electric field Eb Downward Electric field 101 Ferroelectric liquid crystal display device 102 Graphics controller 103 Display panel 104 Scan line drive circuit 105 Information line drive circuit 106 Decoder 107 Scan signal generation circuit 108 Shift register 109 Line memory 110 Information signal generation circuit 11 Drive control circuit 112 GCPU 113 host CPU 114 VRAM

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // G02F 1/1337 510 G02F 1/1337 510 (58) Field surveyed (Int.Cl. ⁶ , DB name) C09K 19/20 C09K 19/30 C09K 19/34 C09K 19/42 G02F 1/13 G02F 1/337 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (28)

(57) [Claims] An optically active compound represented by the following general formula (I): (Wherein, R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₁ represents a single bond,
-O-, -CO-, -COO-, -OOC-;
₂ -OCH ₂ -, - OOC- shows a. A ₁ , A
₂ and A ₃ are Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. A) a liquid crystal composition comprising at least one of the following. 2. The liquid crystal composition according to claim 1, wherein X _{2 in the} optically active compound represented by the general formula (I) is —OCH ₂ —. 3. An optically active compound represented by the following general formula (I): (Wherein, R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₁ represents a single bond,
-O-, -CO-, -COO-, -OOC-;
₂ -OCH ₂ -, - OOC- shows a. A ₁ , A
₂ and A ₃ are Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. ) And a liquid crystalline compound represented by the following general formula (II): (Wherein, R ₃ and R ₄ represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₃ represents a single bond,-
O- and -OOC- are shown. p is 0 or 1. A ₄
Is Is shown. A) a liquid crystal composition comprising at least one of the following. 4. The liquid crystal composition according to claim 3, wherein X _{2 in the} optically active compound represented by the general formula (I) is —OCH ₂ —. 5. An optically active compound represented by the following general formula (I): (Wherein, R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₁ represents a single bond,
-O-, -CO-, -COO-, -OOC-;
₂ -OCH ₂ -, - OOC- shows a. A ₁ , A
₂ and A ₃ are Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. ) And a liquid crystal compound represented by the following general formula (II): (Wherein, R ₃ and R ₄ represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₃ represents a single bond,-
O- and -OOC- are shown. p is 0 or 1. A ₄
Is Is shown. ) And at least one of the following general formula (III)
Optically active compound represented by a) (In the formula, R ₅ represents a linear or branched alkyl group having 1 to 18 carbon atoms. R ₆ represents 1 to 16 carbon atoms.
Represents a linear alkyl group. X ₄ is a single bond, -C
OO-. A ₅ is Is shown. * Indicates optical activity. A) a liquid crystal composition comprising at least one of the following. 6. The liquid crystal composition according to claim 5, wherein in the optically active compound represented by the general formula (I), X ₂ is —OCH ₂ —. 7. The liquid crystal composition according to claim 1, comprising 1 to 80% by weight of the optically active compound represented by the general formula (I) based on the liquid crystal composition. 8. The liquid crystal composition according to claim 1, comprising 1 to 60% by weight of the optically active compound represented by the general formula (I) based on the liquid crystal composition. 9. The liquid crystal composition according to claim 1, comprising 1 to 40% by weight of the optically active compound represented by the general formula (I) based on the liquid crystal composition. 10. The liquid crystal composition according to claim 1, wherein the liquid crystal composition has a chiral smectic phase. 11. The liquid crystal composition according to claim 1, wherein the liquid crystal composition has a nematic phase. 12. A liquid crystal device comprising the liquid crystal composition according to claim 1 disposed between a pair of electrode substrates. 13. The liquid crystal device according to claim 12, wherein an alignment control layer is provided on the electrode substrate. 14. The liquid crystal device according to claim 13, wherein the alignment control layer is a rubbed layer. 15. The liquid crystal element according to claim 12, wherein the pair of electrode substrates are arranged at a film thickness in which a helix formed by the arrangement of liquid crystal molecules is released. 16. A display device having the liquid crystal element according to claim 12. 17. A display is performed by switching liquid crystal molecules utilizing ferroelectricity exhibited by a liquid crystal composition.
The display device according to the above. 18. The display device according to claim 16, further comprising a light source. 19. A display method using a liquid crystal composition containing an optically active compound represented by the following general formula (I). Embedded image (Wherein, R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₁ represents a single bond,
-O-, -CO-, -COO-, -OOC-;
₂ -OCH ₂ -, - OOC- shows a. A ₁ , A
₂ and A ₃ are Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. ) 20. The display method according to claim 19, wherein the optically active compound represented by the general formula (I) is contained in an amount of 1 to 80% by weight based on the liquid crystal composition. 21. The display method according to claim 19, wherein the optically active compound represented by the general formula (I) is contained in an amount of 1 to 60% by weight based on the liquid crystal composition. 22. The display method according to claim 19, wherein the optically active compound represented by the general formula (I) is contained in an amount of 1 to 40% by weight based on the liquid crystal composition. 23. The display method according to claim 19, wherein the liquid crystal composition has a chiral smectic phase. 24. The display method according to claim 19, wherein the liquid crystal composition has a nematic phase. 25. A display method using a liquid crystal element in which a liquid crystal composition containing an optically active compound represented by the following general formula (I) is disposed between a pair of electrode substrates. Embedded image (Wherein, R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 18 carbon atoms. X ₁ represents a single bond,
-O-, -CO-, -COO-, -OOC-;
₂ -OCH ₂ -, - OOC- shows a. A ₁ , A
₂ and A ₃ are Is shown. Y ₁ and Y ₂ represent H or halogen.
m and n are 0 or 1. * Indicates optical activity. ) 26. The display method according to claim 25, wherein an alignment control layer is provided on the electrode substrate. 27. The display method according to claim 26, wherein the alignment control layer is a rubbed layer. 28. The display method according to claim 25, wherein the pair of electrode substrates are arranged at a film thickness in which a helix formed by the arrangement of liquid crystal molecules is released.