JPH06145158A - Optically active compound, liquid crystal composition containing the same, liquid crystal element containing the same, display method and display device using the same - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as a liquid crystal display element, having excellent switching characteristics and improved low-temperature operation characteristics. CONSTITUTION:A compound of formula I (R1 is 1-18C alkyl, etc.; A1 and A4 are 1,4-phenylene, 2,5-pyrimidylene, etc.; A2 and A3 are single bond and as shown for A1 and A3; B1 is benzoxazole or benzothiazole ring; X1 and X2 are single bond, O-CO, OCH2, etc.; m and n are 0 or l; * is optically active) such as optically active 2-[4-(tetrahydrofuran-2-carbonyloxy)phenyl]-5-octylbenzoxazole. The compound of formula I is obtained by using a compound of formula II as a starting substance, nitrating, reducing, subjecting to ring opening reaction, etc. The compound has a high response speed, effectively alleviates temperature dependence of the response speed and a liquid crystal composition especially showing a ferroelectric chiral smectic phase, containing the compound can be obtained.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a novel liquid crystalline compound,
TECHNICAL FIELD The present invention relates to a liquid crystal composition containing the same, a liquid crystal element using the same, and a display device, and more specifically, a novel liquid crystal composition having improved response characteristics to an electric field, a liquid crystal display element using the same, a liquid crystal-optical shutter, and the like. And a display device using the liquid crystal element for display.

[0002]

2. Description of the Related Art Conventionally, liquid crystals have been applied as electro-optical elements in various fields. Most of the liquid crystal elements currently in practical use are, for example, M. Sch.
adt) and W. Helfri
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
TN (Twisted Nem)
atic) type liquid crystal is used.

These are based on the dielectric alignment effect of liquid crystals, and utilize the effect that the average molecular axis direction is directed in a specific direction by an applied electric field due to the dielectric anisotropy of liquid crystal molecules. The optical response speed limit of these devices is said to be milliseconds, which is too slow for many applications.
On the other hand, in the application to a large flat panel display, the driving by the simple matrix method is the most effective in consideration of price and productivity. The simple matrix method employs an electrode configuration in which a scan electrode group and a signal electrode group are arranged in a matrix, and in order to drive the scan electrode group, an address signal is sequentially and selectively selected and applied to the scan electrode group. Employs a time-division drive system in which a predetermined information signal is synchronized with an address signal and selectively applied in parallel.

However, when the above-mentioned TN type liquid crystal is adopted for the element of such a driving system, the scan electrode is selected and the signal electrode is not selected, or the scan electrode is not selected and the signal electrode is selected. An electric field is applied to a finite amount (so-called "half selection point").

If the difference between the voltage applied to the selection point and the voltage applied to the half selection point is sufficiently large and the voltage threshold value required to align the liquid crystal molecules perpendicularly 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 whole screen (1
The time (duty ratio) in which an effective electric field is applied to one selection point during scanning of a frame decreases at a rate of 1 / N.

For this reason, the voltage difference as an effective value applied to the selected point and the non-selected point in the case of repeating scanning is
As the number of scanning lines increases, the number becomes smaller, and as a result, deterioration of image contrast and crosstalk are inevitable drawbacks.

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

In order to improve this point, the voltage averaging method, 2
The frequency drive method and the multi-matrix method have already been proposed, but none of them is sufficient, and the increase in the screen size and the density of the display element are stopped because the number of scanning lines cannot be increased sufficiently. This is the current situation.

In order to improve the drawbacks of the conventional liquid crystal device, the use of a liquid crystal device having bistability is explained by Clark and Lagerwell.
11) (Japanese Patent Laid-Open No. 56-10721).
6 gazette, US Pat. No. 4,367,924, etc.). Ferroelectric liquid crystals having a chiral smectic C phase (SmC ^* phase) or H phase (SmH ^* phase) are generally used as the bistable liquid crystal.

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

In addition to the above-mentioned characteristic of having bistability, 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 the transition of the alignment state.
It is 3 to 4 orders faster than the response speed due to the effect of the dielectric anisotropy and the 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 above-mentioned conventional TN type element can be solved. A fairly substantial improvement is obtained. In particular, it is expected to be applied to high-speed optical optical shutters, high-density, large-screen displays. For this reason, research has been conducted extensively on liquid crystal materials with ferroelectricity, but the ferroelectric liquid crystal materials developed to date have sufficient characteristics for use in liquid crystal elements, including low-temperature operating characteristics and high-speed response characteristics. It is hard to say that it has.

Between the response time r, the spontaneous polarization magnitude Ps and the viscosity η, the following equation [II]

[0014]

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

Therefore, in order to increase the response speed, there are methods of (a) increasing the magnitude Ps of spontaneous polarization (b) decreasing the viscosity η (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 spontaneous polarization magnitude Ps.

Generally, in a ferroelectric chiral smectic liquid crystal compound having a large spontaneous polarization, the internal electric field of the cell caused by the spontaneous polarization is also large, and there is a tendency that there are many restrictions on the device structure capable of assuming a bistable state. Further, even if the spontaneous polarization is unnecessarily increased, the viscosity tends to increase accordingly, and as a result, the response speed may not be so fast.

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

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

[0019]

SUMMARY OF THE INVENTION The object of the present invention is to have a high response speed and to reduce the temperature dependence of the response speed so that the above-mentioned ferroelectric liquid crystal device can be put to practical use. PROBLEM TO BE SOLVED: To provide a liquid crystal compound, a liquid crystal composition containing the same, particularly a liquid crystal composition exhibiting a ferroelectric chiral smectic phase, a liquid crystal device using the liquid crystal composition, and a display method and a display device using the same. It is in.

[0020]

That is, the present invention is an optically active compound represented by the following general formula (I).

[0021]

[Chemical 40]

(In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are

[0023]

[Chemical 41]

May be replaced by However, Y represents -O- or -S-, W is halogen, C
F ₃ and CN are shown. R ₂ represents H or an alkyl group having 1 to 5 carbon atoms. A ₁ and A ₄ are

[0025]

[Chemical 42]

A ₂ and A ₃ are single bonds and A ₁
, A ₄ is the same. P ₁ and P ₂ are H, F, Cl, Br, CH ₃ , CN or CF, respectively.
₃ is shown. B ₁ is

[0027]

[Chemical 43] Indicates. Z represents -O- or -S-. X ₁ , X
₂ is a single bond,

[0028]

[Chemical 44] Indicates. m and n are 0 or 1. * Indicates that it is optically active. )

The present invention also provides a liquid crystal composition containing at least one kind of the optically active compound, and a liquid crystal element and a display device in which the liquid crystal composition is arranged between a pair of electrode substrates. Is.

Among the optically active compounds represented by the above general formula (I), preferred compounds include (Ia) to (If).

[0031]

[Chemical formula 45]

Among the optically active compounds represented by the formulas (Ia) to (If), the following (I
aa) to (Ifa).

[0033]

[Chemical formula 46]

[0034]

[Chemical 47]

Further, preferred R ₁ is the following (i) to (ii)
selected from i). _{(I) -X 3 -C q H} 2q + 1 -n ( except q is an integer of 3~12.) (Ii)

[0036]

[Chemical 48] (However, m is an integer of 0 to 6, and n is an integer of 1 to 8. Also, it may be optically active.) (Iii)

[0037]

[Chemical 49] (However, r is an integer of 0 to 6, s is 0 or 1, and t is 1
Indicates an integer of -12. It may also be optically active. ) (Iv)

[0038]

[Chemical 50] (However, y is 0 or 1, and x is an integer of 1 to 14.) In the above formula, common X ₃ is

[0039]

[Chemical 51] Indicates.

Next, a general method for synthesizing the optically active compound represented by the general formula (I) will be shown. (1) When Z = O

[0041]

[Chemical 52]

[0042]

[Chemical 53]

The nitration of phenols is described by L. Gattermann in Die P.
raxis des Organischer Che
Mikers (P214), Earl Adams et al. (R. Adams, et al.), J. Am. Am. Che
m. Soc. , 63 , 196 (1941).

The ring-closing reaction is also described by D. W. Hein et al., J. Am. Am.
Chem. Soc. , 79 , 427 (1957) and Wai Kanaoka et al. (Y. Kanaoka et a.
l. ), Chem. Pharm. Bull. , 18 , 5
There is a method described on page 87 (1970).

(2) When Z = S

[0046]

[Chemical 54]

[0047]

[Chemical 55]

[0048]

[Chemical 56]

Further, in the synthesis methods (1) and (2), X ₁ and X ₂ are

[0050]

[Chemical 57]

In the case of ₁ , the hydroxyl group or carboxyl group existing in A ₂ or A ₃ is protected by a protecting group, the ring is closed and then the protecting group is eliminated, and then R ₁ -A ₁ -X.
₁ -A ₂ - or _-A 3 _-X 2 _-A 4 -O
It can be E.

For protection of hydroxyl groups,

[0053]

[Chemical 58] In addition, as protection of carboxyl group

[0054]

[Chemical 59] Is appropriate.

The specific structural formula of the optically active compound represented by the above general formula (I) is shown below.

[0056]

[Chemical 60]

[0057]

[Chemical formula 61]

[0058]

[Chemical formula 62]

[0059]

[Chemical formula 63]

[0060]

[Chemical 64]

[0061]

[Chemical 65]

[0062]

[Chemical formula 66]

[0063]

[Chemical formula 67]

[0064]

[Chemical 68]

[0065]

[Chemical 69]

[0066]

[Chemical 70]

[0067]

[Chemical 71]

[0068]

[Chemical 72]

[0069]

[Chemical formula 73]

[0070]

[Chemical 74]

[0071]

[Chemical 75]

[0072]

[Chemical 76]

[0073]

[Chemical 77]

[0074]

[Chemical 78]

[0075]

[Chemical 79]

[0076]

[Chemical 80]

[0077]

[Chemical 81]

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

Other liquid crystal compounds used in the present invention are represented by the following general formulas (III) to (XIV).

[0080]

[Chemical formula 82]

Preferred compounds of formula (III) are (I
IIa) to (IIId).

[0082]

[Chemical 83]

[0083]

[Chemical 84]

Preferred compounds of the formula (IV) are (IV
a) to (IVc).

[0085]

[Chemical 85]

[0086]

[Chemical 86]

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

[0088]

[Chemical 87]

[0089]

[Chemical 88]

Preferred compounds of the formula (VI) are (VI
a) to (VIf).

[0091]

[Chemical 89]

Here, R ₁ 'and R ₂ ' have 1 to 1 carbon atoms.
8 straight-chain or branched alkyl groups, 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

[0093]

[Chemical 90]

It may be replaced with.

However, R ₁ 'or R ₂ ' represents one CH ₂ group.

[0096]

[Chemical Formula 91]

[0097] or -CH halogen - if it is a replacement alkyl halides, R ₁ 'or R _2' is not bound by a single bond to the ring.

R ₁ 'and R ₂ ' are preferably i) a straight-chain alkyl group having 1 to 15 carbon atoms

[0099]

[Chemical Formula 92] p: 0-5 q: 2-11 integer may be optically active.

[0100]

[Chemical formula 93] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0101]

[Chemical 94] u: 0, 1 v: 1-16 integer

[0102]

[Chemical 95] w: 1 to 15 integer Optically active

[0103]

[Chemical 96] x: 0 to 2 y: 1 to 15 integer

[0104]

[Chemical 97] z: 1 to 15 integer

[0105]

[Chemical 98] A: 0 to 2 B: 1 to 15 integer Optically active

[0106]

[Chemical 99] C: 0 to 2 D: 1 to 15 integer Optically active

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

[0108]

[Chemical 100]

[0109]

[Chemical 101]

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

[0111]

[Chemical 102]

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

[0113]

[Chemical 103]

[0114]

[Chemical 104]

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

[0116]

[Chemical 105]

[0117]

[Chemical formula 106]

[0118]

[Chemical formula 107]

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

[0120]

[Chemical 108]

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

[0122]

[Chemical 109]

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

[0124]

[Chemical 110]

Here, R ₃ 'and R ₄ ' have 1 to 1 carbon atoms.
8 is a straight-chain 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

[0126]

[Chemical 111]

It may be replaced with.

However, when R ₃ 'or R ₄ ' is a halogenated alkyl in which one CH ₂ group is replaced by -CH halogen-, R ₃ 'or R ₄ ' is bonded to the ring by a single bond. do not do.

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

[0130]

[Chemical 112] p: 0-5 q: 2-11 integer may be optically active.

[0131]

[Chemical 113] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0132]

[Chemical 114] u: 0, 1 v: 1-16 integer

[0133]

[Chemical 115] w: 1 to 15 integer Optically active

[0134]

[Chemical formula 116] A: 0 to 2 B: 1 to 15 integer Optically active

[0135]

[Chemical 117] C: 0 to 2 D: 1 to 15 integer Optically active

[0136]

[Chemical 118]

[0137]

[Chemical formula 119]

[0138]

[Chemical 120]

[0139]

[Chemical 121]

Preferred compounds of the formula (IX) are (IX
a) to (IXc).

[0141]

[Chemical formula 122]

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

[0143]

[Chemical 123]

Preferred compounds of the formula (XII) are (X
IIa) to (XIId).

[0145]

[Chemical formula 124]

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

[0147]

[Chemical 125]

More preferable compounds of (Xa) and (Xb) are (Xaa) to (Xbb).

[0149]

[Chemical formula 126]

More preferred compounds of (XI) are (X
Ia) to (XIg).

[0151]

[Chemical 127]

More preferable compounds of (XIIa) to (XIId) include (XIIaa) to (XIIdb).

[0153]

[Chemical 128]

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

[0155]

[Chemical formula 129] May be replaced with.

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

[0157]

[Chemical 130] p: 0-5 q: 2-11 integer may be optically active.

[0158]

[Chemical 131] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0159]

[Chemical 132] w: 1 to 15 integer Optically active

[0160]

[Chemical 133] A: 0 to 2 B: 1 to 15 integer Optically active

[0161]

[Chemical 134] C: 0 to 2 D: 1 to 15 integer Optically active

[0162]

[Chemical 135] Preferred compounds of formula (XIII) are (XIIIa)
To (XIIIc).

[0163]

[Chemical 136] More preferable compounds of (XIIIa) to (XIIIc) include (XIIIaa) to (XIIIch).

[0164]

[Chemical 137]

[0165]

[Chemical 138] Preferred compounds of (XIV) are (XIVa) to (XIVa
IVb).

[0166]

[Chemical 139]

Here, R ₇ ′ and R ₈ ′ are linear or branched alkyl groups having 1 to 18 carbon atoms, and one or two or more non-adjacent —CH in the alkyl group. _Two
The -group may be replaced by -CH halogen.
Further, one or two or more -CH ₂ -groups except the -CH ₂ -group which is directly bonded to X ₁ 'and X ₂ ' are

[0168]

[Chemical 140] May be replaced with.

However, R ₇ 'or R ₈ ' is one CH ₂
The group -CH halogen - if it is a replacement alkyl halides, R ₇ 'or R _8' is not bound by a single bond to the ring.

Further, R ₇ ′ and R ₈ ′ are preferably i) a straight chain alkyl group having 1 to 15 carbon atoms.

[0171]

[Chemical 141] p: 0-5 q: 2-11 integer may be optically active.

[0172]

[Chemical 142] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0173]

[Chemical 143] u: 0, 1 v: 1-16 integer

[0174]

[Chemical 144] w: 1 to 15 integer Optically active

In the present invention, the proportion of the optically active compound of the present invention in the liquid crystal composition is 1% by weight to 80% by weight,
Preferably 1% to 60% by weight, more preferably 1%
It is desirable to set the content to 40% by weight.

When two or more optically active compounds of the present invention are used, the proportion of the mixture of two or more optically active compounds of the present invention in the liquid crystal composition obtained by mixing is 1% by weight to 80%. % By weight, preferably 1% to 60% by weight,
More preferably, it is desirable to set it to 1% by weight to 40% by weight.

Next, the liquid crystal element of the present invention comprises the above-mentioned liquid crystal composition disposed between a pair of electrode substrates. Particularly, the ferroelectric liquid crystal layer in the ferroelectric liquid crystal element is shown above. The liquid crystal composition showing a chiral smectic phase thus prepared is heated in vacuum to an isotropic liquid temperature, enclosed in an element cell, and gradually cooled to form a liquid crystal layer, which can be returned to normal pressure. preferable.

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

Referring to FIG. 1, in the liquid crystal element, 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 orientation control layer 4, respectively, and the layer is formed. The thickness is set by a spacer 5, and a voltage is applied 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
Are sandwiched between a pair of crossed Nicol polarizing plates 8, and a light source 9 is arranged outside one of them.

That is, In ₂ O ₃ , SnO _{2 and} ITO (Indium Tin Oxide; Indium Tin Ox) are respectively provided on the two glass substrates 2.
The transparent electrode 3 made of a thin film such as ide) is covered. An insulating alignment control layer 4 for arranging the liquid crystal in the rubbing direction is formed by rubbing a polymer thin film such as polyimide with gauze or acetate flocking cloth or the like.

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, boron nitride containing hydrogen. Substance, cerium oxide, aluminum oxide, zirconium oxide, inorganic oxide such as titanium oxide and magnesium fluoride is formed, polyvinyl alcohol, polyimide, polyamide imide, polyester imide, polyparaxylene, polyester , Polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate,
It may have a two-layer structure in which a layer of an organic insulating material such as polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin or photoresist resin is formed, or an inorganic material insulating orientation control layer or an organic material insulating property. The orientation control layer may be a single layer.

If this insulating orientation control layer is an inorganic type, it can be formed by a vapor deposition method or the like, and if it is an organic type, a solution in which an organic insulating substance is dissolved, or a precursor solution thereof (0.1 to 20 in a solvent)
% By weight, preferably 0.2 to 10% by weight) and applied by a spinner coating method, a dip coating method, a screen printing method, a spray coating method, a roll coating method, etc. under predetermined curing conditions (for example, under heating). ) And can be formed by curing.

The layer thickness of the insulating orientation control layer 4 is usually 30Å or more.
1 μm, preferably 30Å to 3000Å, more preferably 50Å to 1000Å.

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 with a sealing material, for example, an epoxy adhesive material. Other,
A polymer film or glass fiber may be used as the spacer. A liquid crystal exhibiting a chiral smectic phase is enclosed between the two glass substrates. Liquid crystal layer 1
Is generally 0.5 to 20 μm, preferably 1 to 5 μm
Is set to the thickness of.

Further, this chiral smectic liquid crystal
It is desirable to have a SmC ^* phase (chiral smectic C phase) at a wide temperature including room temperature (particularly on the low temperature side) and to have a high-speed response. Furthermore, it is desired that the temperature dependence of the response speed be small and that the drive voltage margin be wide.

Further, in particular, when it is used as an element, in order to exhibit a good uniform alignment property and obtain a monodomain state, the ferroelectric liquid crystal has an isotropic phase to a Ch phase (cholesteric phase) -S.
It is desirable to have a phase transition series of mA phase (smectic phase) -SmC (chiral smectic C phase).

The transparent electrode 3 is connected to an external power source 7 by a lead wire. Further, on the outer side of the glass substrate 2, a pair of polarizing plates 8 whose polarization axes are, for example, orthogonal crossed Nicols state are attached. The example of FIG. 1 is a transmissive type, and includes a light source 9.

FIG. 2 is a schematic drawing of 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 composed of a thin film such as ndium tin oxide (Sn), in which the liquid crystal molecular layer 22 is oriented so as to be perpendicular to the glass surface.
Liquid crystal of mC ^* phase or SmH ^* phase is enclosed.
A thick line 23 represents a liquid crystal molecule, and this liquid crystal molecule 23 has a dipole moment (P⊥) 24 in a direction orthogonal to the molecule. When a voltage above a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and the dipole moment (P⊥)
The liquid crystal molecules 23 can change the orientation direction so that all 24 are oriented in the electric field direction. The liquid crystal molecule 23 has an elongated shape and exhibits refractive index anisotropy in the major axis direction and the minor axis direction thereof. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the voltage application polarity is increased. It can be easily understood that the liquid crystal optical modulation element changes its optical characteristics depending on the situation.

The liquid crystal cell preferably used in the optical modulator of the present invention has a sufficiently thin thickness (for example, 1
0 μ or less). As the liquid crystal layer becomes thinner in this way, as shown in FIG. 3, the helical structure of the liquid crystal molecules is unwound even when no electric field is applied, and the dipole moment Pa or Pb thereof is directed upward (34a) or downward (34b). Take either state. When an electric field Ea or Eb having a polarity equal to or greater than a certain threshold is applied to such a cell by the voltage applying means 31a and 31b, 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 stable state 34a or the downward stable direction 34b, and accordingly, the liquid crystal molecules move to 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 alignment of the liquid crystal molecules has bistability. The second point will be further explained with reference to FIG. 3, for example.
When a is applied, the liquid crystal molecules are aligned in the first stable state 33a, but this state is stable even when the electric field is cut off. When a reverse electric field Eb is applied, the liquid crystal molecules are oriented in the second stable state 33b to change the orientation of the molecules, but they remain in this state even when the electric field is cut off. Further, as long as the applied electric field Ea or Eb does not exceed a certain threshold value, the previous alignment state is still maintained.

By using the liquid crystal element of the present invention in the display panel section and taking the communication information synchronizing means by the data format as the image information having the scanning line address information and the SYNC signal shown in FIGS. 4 and 5, a liquid crystal display device is obtained. To realize.

In the figure, the symbols are as follows. 101 ferroelectric liquid crystal display device 102 graphics controller 103 display panel 104 scanning line driving circuit 105 information line driving circuit 106 decoder 107 scanning signal generating circuit 108 shift register 109 line memory 110 information signal generating circuit 111 driving control circuit 112 GCPU 113 host CPU 114 VRAM

By using the liquid crystal device of the present invention in the display panel section and taking the communication information synchronizing means by the data format as the image information having the scanning line address information and the SYNC signal shown in FIGS. 4 and 5, the liquid crystal display device is obtained. To realize.

The image information is generated by the graphics controller 102 on the main body side and transferred to the display panel 103 in accordance with the signal transfer means shown in FIGS. The graphics controller 102 is a CP
U (central processing unit, hereinafter abbreviated as GCPU 112) and VRAM (memory for storing image information) 114 are used as cores for managing image information and communication between the host CPU 113 and the liquid crystal display device 101, and controlling the present invention. The method is mainly implemented on the graphics controller 102. A light source is arranged on the back surface of the display panel.

[0195]

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.

Example 1 Production of Optically Active 2- [4- (Tetrahydrofuran-2-carbonyloxy) phenyl] -5-octylbenzoxazole (Exemplified Compound 19) It was produced according to the following steps.

[0197]

[Chemical 145]

4-acetoxybenzoic acid 2.90 g (1
6.1mole), thionyl chloride 3.7ml 20m
The mixture was placed in a 1 eggplant flask, and 2 drops of N, N-dimethylformamide were added with stirring at room temperature. Then, the mixture was stirred under reflux for 20 minutes. After completion of the reaction, dry benzene was added to the reaction product, and excess thionyl chloride was distilled off together with benzene by vacuum distillation. This operation was repeated twice. The resulting 4-acetoxybenzoic acid chloride, 2.10 g (15.1 mmole) of 2-amino-4-octylphenol and dioxane 4
Put 0 ml in a 100 ml eggplant flask and set the internal temperature to 80-8.
While maintaining the temperature at 4 ° C., 5.5 ml of pyridine was added dropwise while stirring with heating.

After completion of dropping, the mixture was heated and stirred at an internal temperature of 85 to 88.5 ° C. for 20 minutes. After the reaction was completed, the reaction product was cooled with ice, and ice water was added to about 2
It was opened to 00 ml. The precipitated crystals were collected by filtration, washed with water, and recrystallized from methanol to give 4- (4-acetoxybenzoylamino) -4-octylphenol (4.10 g, yield 7).
0.8%) was obtained.

[0200]

[Chemical 146]

2- (4-acetoxybenzoylamino)
-4-Octylphenol 4.00 g (10.4 mmo
le), 0.40 g of p-toluenesulfonic acid monohydrate,
40 ml of o-dichlorobenzene was placed in a 200 ml eggplant-shaped flask and heated and stirred at 188 to 192 ° C. for 1 hour. After completion of the reaction, o-dichlorobenzene was distilled off under reduced pressure, 1.98 g (30.0 mmole) of potassium hydroxide and 60 ml of ethanol were added to the residue, and 1 was added on a water bath kept at about 75 ° C.
The mixture was heated and stirred for an hour.

After completion of the reaction, ethanol was distilled off under reduced pressure, and water was added to the residue. Ice-cooled stirred concentrated hydrochloric acid 6.0 ml (34.0
mmole) was added and the precipitated crystals were collected by filtration, washed with water and recrystallized from ethanol to give 2- (4-hydroxyphenyl)-.
2.70 g of 5-octylbenzoxazole (yield 8
0.0%) was obtained.

[0203]

[Chemical 147]

0.22 g (0.68 mmo) 2- (4-hydroxyphenyl) -5-octylbenzoxazole
le), 0.08 g (0.68 mmol) of S-(-)-tetrahydrofuran-2-carboxylic acid, and 5 ml of dichloromethane were placed in a 30 ml eggplant flask and dissolved, and 0.14 g of N, N'-dicyclohexylcarbodiimide while stirring at room temperature. (0.68 mmole) and 0.02 g of 4-pyrrolidinopyridine were sequentially added, and the mixture was stirred at room temperature for 6 hours.

The precipitated N, N'-dicyclohexylurea was filtered off, and the filtrate was dried under reduced pressure. The residue was purified by silica gel column chromatography (eluent: toluene), recrystallized from ethanol and optically active 2- [4- (tetrahydrofuran-2-carbonyloxy) phenyl] -5-octylbenzoxazole 0.15 g (yield 52%).
The phase transition temperature of this compound is shown below.

[0206]

[Equation 2]

Example 2 Production of Optically Active 2- [4- (Tetrahydrofuran-2-carbonyloxy) phenyl] -6-octylbenzothiazole (Exemplified Compound 85)

[0208]

[Chemical 148]

57 g (0.28 m) of 4-octylaniline
ol), potassium thiocyanate 54.8 g (0.56 m
ol) and 400 ml of acetic acid were cooled to 10 ° C or lower and stirred. A mixed solution of 45.0 g of bromine and 135 ml of acetic acid was added dropwise thereto, and stirring was continued for 90 minutes. After the reaction is complete, water 500
After adding ml, and performing hot filtration, aqueous ammonia was added and ice-cooled. The precipitated crystals were filtered, and hexane / benzene (1 /
It was recrystallized in 1) to obtain 34.0 g of 2-amino-6-octylbenzothiazole. Yield 46%

[0210]

[Chemical 149]

2-Amino-6-octylbenzothiazole 33.6 g (0.128 mmol), water 136 ml,
136.4 g of KOH was refluxed for 6 hours. After cooling, ethanol was added, and 5N acetic acid aqueous solution was added dropwise to adjust the pH to 9. The precipitate was filtered off and the filtrate was filtered with ZnCl ₂ .
After adding a solution of 9 g dissolved in a 15% acetic acid aqueous solution,
Heated at 70 ° C. for 30 minutes. The crystals were filtered and washed with ethanol and water to obtain 30.0 g of 5-octyl-2-aminobenzenethiol zinc salt. Yield 74%

[0212]

[Chemical 150]

1.72 g of 4-acetoxybenzoic acid (9.
(55 mmol) was added with thionyl chloride (5.0 ml) and the mixture was refluxed for 1 hour. After refluxing, excess thionyl chloride was distilled off under reduced pressure. Benzene was added and further distilled off. To this acid chloride, 2.50 g (4.65 mmol) of 5-octyl-2-aminobenzenethiol zinc salt was added, and the mixture was heated at 200 ° C. for 30 minutes.
Stir for minutes. The reaction solution was allowed to cool, water was added, and the mixture was extracted with ethyl acetate.

The extract was concentrated and potassium hydroxide 1.50 was added.
g (22.7 mmol) and 50 ml of ethanol were added,
It was hydrolyzed by stirring in a water bath for 1 hour. After the completion, 2.5 ml of water-concentrated hydrochloric acid was added to make the solution acidic, and the precipitated crystals were separated by filtration. After washing with water, recrystallization (acetone / methanol) was performed to obtain 1.64 g of 2- (4-hydroxyphenyl) -6-octylbenzothiazole. 52% yield

[0215]

[Chemical 151]

2- (4-hydroxyphenyl) -6-octylbenzothiazole 0.50 g (1.47 mmo)
l), S-(-)-tetrahydrofuran-2-carboxylic acid 0.18 g (1.55 mmol), dichloromethane 1
0 ml was stirred at room temperature, to which 0.32 g (1.55 mmol) of N, N'-dicyclohexylcarbodiimide,
4-Pyrrolidinopyridine 0.03g was added and it stirred at room temperature for 6 hours. The precipitated crystals were filtered off, the filtrate was concentrated and then recrystallized (once with toluene / ethanol and once with acetone) to give optically active 2- [4- (tetrahydrofuran-
0.15 g of 2-carbonyloxy) phenyl] -6-octylbenzothiazole was obtained. Yield 64% The phase transition temperature of this compound is shown below.

[0217]

[Equation 3]

Example 3 Preparation of Optically Active 2- [2-Fluoro-4- (tetrahydrofuran-2-carbonyloxy) phenyl] -6-octylbenzothiazole (Exemplified Compound) 19 4- 4-acetoxybenzoic acid instead of 4- Acetoxy-2
-Prepared by the same method as in Example 2 except that fluorobenzoic acid was used, and the route was as follows.

[0219]

[Chemical 152] The phase transition temperature of this compound is shown.

[0220]

[Equation 4]

Example 4 The following compounds including the exemplified compound 19 produced in Example 1 were mixed in the following parts by weight to prepare a liquid crystal composition A.

[0222]

[Chemical 153]

The liquid crystal composition A exhibits the following phase transition temperatures.

[0224]

[Equation 5]

Example 5 Two 0.7 mm thick glass plates were prepared, an ITO film was formed on each glass plate, and voltage application electrodes were prepared.
Further, SiO ₂ was vapor-deposited on this to form an insulating layer. Silane coupling agent on glass plate [KB manufactured by Shin-Etsu Chemical Co., Ltd.
M-602] 0.2% isopropyl alcohol solution was rotated at a rotation speed of 2000 r. p. m spinner applied for 15 seconds and surface-treated. After that, heat drying treatment was performed at 120 ° C. for 20 minutes.

[0226] A polyimide resin precursor [Toray Industries, Inc. SP-
510] Rotate the 1.5% dimethylacetamide solution at a rotation speed of 2
000r. p. m spinner for 15 seconds. After the film formation, the film was heat-condensed and baked at 300 ° C. for 60 minutes.
At this time, the film thickness of the coating film was about 250Å.

[0227] The baked coating was rubbed with an acetate flocked cloth, washed with an isopropyl alcohol solution, sprayed with alumina beads having an average particle size of 2 µm on one glass plate, and then rubbed. The axes were made parallel to each other, the glass plates were laminated using an adhesive sealant [Rixon Bond (Chisso Corporation)], and heated and dried at 100 ° C. for 60 minutes to prepare a cell.

The liquid crystal composition A mixed in Example 4 was injected into this cell in an isotropic liquid state and gradually cooled from the isotropic phase to 20 ° C./h to 25 ° C. to obtain a ferroelectric liquid crystal device. Created. When the cell thickness of this cell was measured with a Berek phase plate, it was about 2 μm.

Using this ferroelectric liquid crystal device, the magnitude Ps of spontaneous polarization and the peak-to-peak voltage Vpp = 20V
The voltage was applied to detect the optical response under the crossed Nicols (change in transmitted light amount 0 to 90%), and the response speed (hereinafter referred to as the optical response speed) was measured. The measurement results are shown below.

[0230]

[Table 1] 10 ° C. 30 ° C. 40 ° C. Response speed 400 μsec 163 μsec 113 μsec Ps 11.0 nC / cm ² 6.8 nC / cm ² 4.6 nC / cm ²

Example 6 The following compounds including the exemplified compound 91 produced in Example 3 were mixed in the following parts by weight to prepare a liquid crystal composition B.

[0232]

[Chemical 154] The liquid crystal composition B has the following phase transition temperatures.

[0233]

[Equation 6]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition B was used, and the magnitude of spontaneous polarization Ps and the optical response speed were determined in the same manner as in Example 5. It was measured. The measurement results are shown below.

[0235]

[Table 2] 10 ° C 30 ° C 40 ° C Response speed 328 μsec 138 μsec 90 μsec Ps 12.3 nC / cm ² 7.9 nC / cm ² 5.4 nC / cm ²

Example 7 Liquid Crystal Composition C was prepared by mixing the following compounds in the following parts by weight.

[0237]

[Chemical 155]

[0238]

[Chemical 156]

Further, with respect to this liquid crystal composition C, the following exemplary compounds were mixed in the respective parts by weight shown below to prepare a liquid crystal composition D.

[0240]

[Chemical 157]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that the liquid crystal composition D was injected into the cell.
The optical response speed was measured. The measurement results are shown below.

[0242]

[Table 3] 10 ° C 25 ° C 40 ° C Response speed 439 μsec 213 μsec 114 μsec

Comparative Example 1 A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that the liquid crystal composition C mixed in Example 7 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0244]

[Table 4] 10 ° C 25 ° C 40 ° C Response speed 784 μsec 373 μsec 197 μsec

Example 8 Liquid crystal composition E was prepared by mixing the following exemplified compounds in place of the exemplified compounds 2 and 13 used in Example 7 in the following parts by weight.

[0246]

[Chemical 158]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition was used.
The optical response speed was measured by the same method. The measurement results are shown below.

[0248]

[Table 5] 10 ° C 25 ° C 40 ° C Response speed 451 μsec 220 μsec 118 μsec

Example 9 Liquid Crystal Composition F was prepared by mixing the following compounds in the following parts by weight.

[0250]

[Chemical 159]

[0251]

[Chemical 160]

Further, with respect to this liquid crystal composition F, the following exemplified compounds were mixed in the respective parts by weight shown below to prepare a liquid crystal composition G.

[0253]

[Chemical 161]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that the liquid crystal composition F was injected into the cell.
The optical response speed was measured and the switching state was observed.
The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0255]

[Table 6] 10 ° C 25 ° C 40 ° C Response speed 359 μsec 176 μsec 89 μsec

Further, a clear switching operation was observed during driving, and the bistability when the voltage application was stopped was good.

Comparative Example 2 A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that the liquid crystal composition H mixed in Example 9 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0258]

[Table 7] 10 ° C 25 ° C 40 ° C Response speed 653 μsec 317 μsec 159 μsec

Example 10 A liquid crystal composition H was prepared by mixing the exemplified compounds shown below instead of the exemplified compounds 30 and 105 used in Example 9 in the weight parts shown below.

[0260]

[Chemical 162]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state was observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0262]

[Table 8] 10 ° C 25 ° C 40 ° C Response speed 355 μsec 177 μsec 90 μsec

Example 11 A liquid crystal composition I was prepared by mixing the exemplified compounds shown below instead of the exemplified compounds 30 and 105 used in Example 9 in the respective parts by weight shown below.

[0264]

[Chemical formula 163]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state was observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0266]

[Table 9] 10 ° C 25 ° C 40 ° C Response speed 349 μsec 173 μsec 88 μsec

Example 12 A liquid crystal composition J was prepared by mixing the following compounds in the following parts by weight.

[0268]

[Chemical 164]

[0269]

[Chemical 165]

Further, with respect to this liquid crystal composition J, the following exemplary compounds were mixed in the respective parts by weight shown below to prepare a liquid crystal composition K.

[0271]

[Chemical 166]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state was observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0273]

[Table 10] 10 ° C 25 ° C 40 ° C Response speed 307 μsec 158 μsec 86 μsec

Comparative Example 3 A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that the liquid crystal composition J mixed in Example 12 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0275]

[Table 11] 10 ° C 25 ° C 40 ° C Response speed 668 μsec 340 μsec 182 μsec

Example 13 A liquid crystal composition L was prepared by mixing the exemplified compounds shown below in place of the exemplified compounds 12, 63 and 142 used in Example 12 in the respective parts by weight shown below.

[0277]

[Chemical 167]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 5 except that this liquid crystal composition was used.
The optical response speed was measured by the same method. The measurement results are shown below.

[0279]

[Table 12] 10 ° C 25 ° C 40 ° C Response speed 327 μsec 169 μsec 91 μsec

As is clear from Examples 7 to 13, the ferroelectric liquid crystal devices containing the liquid crystal compositions D, E, G, H, I, K and L according to the present invention have operating characteristics at low temperatures and high-speed response. The characteristics are improved, and the temperature dependence of the response speed is also reduced.

Example 14 Except that the polyimide resin precursor 1.5% dimethylacetamide solution used in Example 7 was replaced with a 2% aqueous solution of polyvinyl alcohol resin [PUA-117 manufactured by Kuraray Co., Ltd.]. Create a ferroelectric liquid crystal element by the method of
The optical response speed was measured in the same manner as in Example 7. The measurement results are shown below.

[0282]

[Table 13] 10 ° C 25 ° C 40 ° C Response speed 429 μsec 208 μsec 111 μsec

Example 15 A ferroelectric liquid crystal device was prepared and carried out in the same manner as in Example 5 except that the alignment control layer was prepared only with a polyimide resin without using SiO ₂ used in Example 7. The optical response speed was measured in the same manner as in Example 7. The measurement results are shown below.

[0284]

[Table 14] 10 ° C. 25 ° C. 40 ° C. Response speed 411 μsec 200 μsec 107 μsec

As is apparent from Examples 14 and 15, even when the element structure was changed, the element containing the ferroelectric liquid crystal composition according to the present invention had much improved low-temperature operating characteristics as in Example 7. In addition, the temperature dependence of the response speed is reduced.

[0286]

If the compound of the present invention exhibits a chiral smectic phase by itself, it becomes a material that can be effectively applied to a device utilizing ferroelectricity. Further, when the liquid crystal composition having the compound of the present invention exhibits a chiral smectic phase,
An element containing the liquid crystal composition can be operated by utilizing the ferroelectricity of the liquid crystal composition. Ferroelectric liquid crystal elements that can be used in this manner can be liquid crystal elements having good switching characteristics and improved low-temperature operating characteristics, and liquid crystal elements having reduced temperature dependence of response speed.

A display device in which the liquid crystal device of the present invention is used as a display device in combination with a light source, a drive circuit, etc. is a good device.

[Brief description of 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 the liquid crystal display device and the graphics controller.

[Explanation of symbols]

1 Liquid Crystal Layer Having 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 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 scanning line driving circuit 105 information line driving circuit 106 decoder 107 scanning signal generating circuit 108 shift register 109 line memory 110 information signal generating circuit 111 Drive control circuit 112 GCPU 113 Host CPU 114 VRAM

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location G02F 1/13 500 (72) Inventor Goji Kadono 3-30-2 Shimomaruko, Ota-ku, Tokyo Kya Non-Incorporated (72) Inventor Yoko Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (28)

[Claims] 1. An optically active compound represented by the following general formula (I). [Chemical 1] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. R ₂ represents H or an alkyl group having 1 to 5 carbon atoms. A ₁ and A ₄ are as follows: , A ₂ and A ₃ are the same as single bond and A ₁ and A ₄ . P ₁ and P ₂ are H and
Indicates F, Cl, Br, CH ₃ , CN or CF ₃ . B ₁ is Indicates. Z represents -O- or -S-. X ₁ , X
₂ is a single bond, Indicates. m and n are 0 or 1. * Indicates that it is optically active. ) 2. The optically active compound according to claim 1, wherein the optically active compound represented by the general formula (I) is any of the following (Ia) to (If). [Chemical 6] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. A ₁ and A ₄ are as follows , A ₂ and A ₃ are the same as single bond and A ₁ and A ₄ . P ₁ and P ₂ are H and
Indicates F, Cl, Br, CH ₃ , CN or CF ₃ . X ₁ and X ₂ are single bonds, and Indicates. * Indicates that it is optically active. ) 3. The optically active compound according to claim 1, wherein the optically active compound represented by the general formula (I) is any one of the following (Iaa) to (Ifa). [Chemical 10] [Chemical 11] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. A ₁ and A ₄ are as follows Indicates. Further, P ₁ and P ₂ are H, F, Cl, and
It represents Br, CH ₃ , CN or CF ₃ . * Indicates that it is optically active. ) 4. The optically active compound according to claim 1, wherein R _{1 in the} general formula (I) is any of the following (i) to (iv). _{(I) -X 3 -C q H} 2q + 1 -n ( although, q is an integer of 3~12.) (Ii) [of 14] (However, m is an integer of 0 to 6 and n is an integer of 1 to 8. Also, it may be optically active.) (Iii) (However, r is an integer of 0 to 6, s is 0 or 1, and t is 1
Indicates an integer of -12. It may also be optically active. ) (Iv) (However, y is 0 or 1, and x is an integer of 1 to 14.) In the above formula, the common X ₃ is Indicates. 5. A liquid crystal composition comprising at least one kind of the optically active compound according to claim 1. 6. The liquid crystal composition according to claim 5, 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. 7. The liquid crystal composition according to claim 5, which contains the optically active compound represented by the general formula (I) in an amount of 1 to 60% by weight based on the liquid crystal composition. 8. The liquid crystal composition according to claim 5, wherein the optically active compound represented by formula (I) is contained in an amount of 1 to 40% by weight based on the liquid crystal composition. 9. The liquid crystal composition according to claim 5, wherein the liquid crystal composition has a chiral smectic phase. 10. A liquid crystal device comprising the liquid crystal composition according to claim 5 disposed between a pair of electrode substrates. 11. The liquid crystal device according to claim 10, further comprising an alignment control layer provided on the electrode substrate. 12. The liquid crystal device according to claim 11, wherein the alignment control layer is a layer subjected to a rubbing treatment. 13. The liquid crystal device according to claim 10, wherein the pair of electrode substrates are arranged with a film thickness in which a spiral formed by an arrangement of liquid crystal molecules is released. 14. A display device comprising the liquid crystal element according to claim 10. 15. The display is performed by switching the liquid crystal molecules by utilizing the ferroelectricity of the liquid crystal composition.
Display device described. 16. The display device according to claim 14, further comprising a light source. 17. A display method using a liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I) for display. [Chemical 18] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. R ₂ represents H or an alkyl group having 1 to 5 carbon atoms. A ₁ and A ₄ are as follows , A ₂ and A ₃ are the same as single bond and A ₁ and A ₄ . P ₁ and P ₂ are H and
Indicates F, Cl, Br, CH ₃ , CN or CF ₃ . B ₁ is Indicates. Z represents -O- or -S-. X ₁ , X
₂ is a single bond, Indicates. m and n are 0 or 1. * Indicates that it is optically active. ) 18. The display method according to claim 17, wherein the optically active compound represented by the general formula (I) is any one of the following (Ia) to (If). [Chemical formula 23] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. A ₁ and A ₄ are as follows , A ₂ and A ₃ are the same as single bond and A ₁ and A ₄ . P ₁ and P ₂ are H and
Indicates F, Cl, Br, CH ₃ , CN or CF ₃ . X ₁ and X ₂ are single bonds, Indicates. * Indicates that it is optically active. ) 19. The display method according to claim 17, wherein the optically active compound represented by the general formula (I) is any of the following (Iaa) to (Ifa). [Chemical 27] [Chemical 28] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. A ₁ and A ₄ are as follows Indicates. Further, P ₁ and P ₂ are H, F, Cl, and
It represents Br, CH ₃ , CN or CF ₃ . * Indicates that it is optically active. ) 20. The display method according to claim 17, wherein R _{1 in the} general formula (I) is any of the following (i) to (iv). _{(I) -X 3 -C q H} 2q + 1 -n ( although, q is an integer of 3~12.) (Ii) [of 31] (However, m is an integer of 0 to 6, and n is an integer of 1 to 8. It may be optically active.) (Iii) (However, r is an integer of 0 to 6, s is 0 or 1, and t is 1
Indicates an integer of -12. It may also be optically active. ) (Iv) (However, y is 0 or 1, and x is an integer of 1 to 14.) In the above formula, the common X ₃ is Indicates. 21. The display method according to claim 17, 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. 22. The display method according to claim 17, wherein the optically active compound represented by formula (I) is contained in an amount of 1 to 60% by weight based on the liquid crystal composition. 23. The display method according to claim 17, wherein the optically active compound represented by formula (I) is contained in an amount of 1 to 40% by weight based on the liquid crystal composition. 24. The display method according to claim 17, wherein the liquid crystal composition has a chiral smectic phase. 25. A display method in which a liquid crystal element comprising a liquid crystal composition containing at least one optically active compound represented by the following general formula (I) is disposed between a pair of electrode substrates for display. [Chemical 35] (In the formula, R ₁ is a linear or branched alkyl group having 1 to 18 carbon atoms, and one or two or more non-adjacent methylene groups in the alkyl group are represented by: May be replaced by However, Y is -O-
Or indicates -S-, W is _halogen, CF 3, CN
Indicates. R ₂ represents H or an alkyl group having 1 to 5 carbon atoms. A ₁ and A ₄ are as follows , A ₂ and A ₃ are the same as single bond and A ₁ and A ₄ . P ₁ and P ₂ are H and
Indicates F, Cl, Br, CH ₃ , CN or CF ₃ . B is Indicates. Z represents -O- or -S-. X ₁ , X
₂ is a single bond, Indicates. m and n are 0 or 1. * Indicates that it is optically active. ) 26. The display method according to claim 25, further comprising an alignment control layer provided on the electrode substrate. 27. The display method according to claim 26, wherein the orientation control layer is a layer subjected to a rubbing treatment. 28. The display method according to claim 25, wherein the pair of electrode substrates are arranged with a film thickness in which the spiral formed by the alignment of liquid crystal molecules is released.