JPH06128276A - Liquid crystal compound, liquid crystal composition containing the same, liquid crystal element having the same, display method and display device using the same - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] A liquid crystal compound having a high response speed and effective in reducing the temperature dependence of the response speed, a liquid crystal composition containing the same, and a liquid crystal composition A liquid crystal element to be used, and a display method and a display device using the same are provided. [Configuration] (For example, And a liquid crystal composition containing at least one liquid crystal compound, a liquid crystal device having the liquid crystal composition arranged between a pair of electrode substrates, and a display method using the same. Display device.

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 τ, the magnitude Ps of spontaneous polarization and the viscosity η, the following equation [II]

[0014]

[Equation 1] (However, E is the 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 provides the following general formula (I):

[0021]

[Chemical formula 26]

(In the formula, R ₁ and R ₂ are each a carbon number of 1 to
18 linear or branched alkyl groups, wherein one or two non-adjacent methylene groups in the alkyl group are -O-, -S-, -CO-, -COO-, -OCO.
It may be substituted with-, or a hydrogen atom may be substituted with a fluorine atom. However, either one of R ₁ and R ₂

[0023]

[Chemical 27]

And the other is hydrogen atom, halogen, C
It may be N. X represents O or S, and A ₁ , A
₂ , A ₃ is

[0025]

[Chemical 28]

And Y ₁ and Y ₂ are hydrogen atoms, F,
Cl, Br, is _CH 3, CN or CF _3. Z
₁ , Z ₂ is a single bond, -COO-, -OCO-, -C.
H ₂ O-or -OCH ₂ - indicates, _{Z 3} is -O
-, -CO-, -COO- or -OCO- is shown. R
₃ , R ₄ and R ₅ are linear or branched alkyl groups having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is -O- or -COO.
-, -OCO- may be exchanged. p and q are 0 or 1. n represents an integer of 1 to 12. )

A liquid crystal compound represented by the following formula, a liquid crystal composition containing at least one kind of the liquid crystal compound, and a liquid crystal element and a display device in which the liquid crystal composition is arranged between a pair of electrode substrates. It is a thing.

Among the liquid crystal compounds represented by the formula (I), preferable compounds include [Ia] to [Ic].

[0029]

[Chemical 29]

Among the liquid crystal compounds represented by the formulas [Ia] to [Ic], more preferable compounds include the following [Iaa] to [Ich].

[0031]

[Chemical 30]

[0032]

[Chemical 31]

Y ₁ and Y ₂ are preferably a hydrogen atom, a halogen atom or a trifluoromethyl group, more preferably a hydrogen atom or a fluorine atom. R ₁ and R ₂ are preferably selected from the following.

[0034]

[Chemical 32]

R_Three , R_Four , R₅ Is preferably carbon
It is an alkyl group having 1 to 12 atoms, and more preferably charcoal.
A linear alkyl group having 1 to 8 elementary atoms is particularly preferable.
Is R _Three , R_Four , R₅ At least two are methyl groups
Is.

The present inventors have found that the ferroelectric chiral smectic liquid crystal containing at least one compound having a benzoxazole ring or a benzothiazole ring in the skeleton of the present invention and having a trialkylsilylalkyl group in the side chain. It has been found that the composition and the liquid crystal element using the composition have improved various characteristics such as good orientation, high-speed response, and reduction of temperature dependence of response speed, thereby obtaining good display characteristics.

Next, an example of a method for synthesizing the liquid crystalline compound represented by the above general formula (I) is shown below.

[0038]

[Chemical 33]

[0039]

[Chemical 34]

R ₁ is A ₁ or a benzene ring, and R ₂
Is A ₃ or A ₂ and -O-, -S-, -CO-,
When bonded with -COO- or -OCO-, the functional group bonded to A ₁ or a benzene ring, A ₂ or A ₃ is protected, and after the ring is closed, the protective group is removed, and then

[0041]

[Chemical 35] It is also possible to

The specific structural formula of the liquid crystalline compound represented by the general formula (I) is shown below.

[0043]

[Chemical 36]

[0044]

[Chemical 37]

[0045]

[Chemical 38]

[0046]

[Chemical Formula 39]

[0047]

[Chemical 40]

[0048]

[Chemical 41]

[0049]

[Chemical 42]

[0050]

[Chemical 43]

[0051]

[Chemical 44]

[0052]

[Chemical formula 45]

[0053]

[Chemical formula 46]

[0054]

[Chemical 47]

[0055]

[Chemical 48]

[0056]

[Chemical 49]

[0057]

[Chemical 50]

[0058]

[Chemical 51]

[0059]

[Chemical 52]

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).

[0062]

[Chemical 53]

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

[0064]

[Chemical 54]

[0065]

[Chemical 55]

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

[0067]

[Chemical 56]

[0068]

[Chemical 57]

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

[0070]

[Chemical 58]

[0071]

[Chemical 59]

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

[0073]

[Chemical 60]

Here, R ₁ 'and R ₂ ' are carbon numbers 1 to 1
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

[0075]

[Chemical formula 61]

It may be replaced with

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

[0078]

[Chemical formula 62]

Or when it is an alkyl halide substituted with -CH halogen-, R ₁ 'or R ₂ ' is not attached 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

[0081]

[Chemical formula 63] p: 0-5 q: 2-11 integer may be optically active.

[0082]

[Chemical 64] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0083]

[Chemical 65] u: 0, 1 v: 1-16 integer

[0084]

[Chemical formula 66] w: 1 to 15 integer Optically active

[0085]

[Chemical formula 67] x: 0 to 2 y: 1 to 15 integer

[0086]

[Chemical 68] z: 1 to 15 integer

[0087]

[Chemical 69] A: 0 to 2 B: 1 to 15 integer Optically active

[0088]

[Chemical 70] C: 0 to 2 D: 1 to 15 integer Optically active

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

[0090]

[Chemical 71]

[0091]

[Chemical 72]

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

[0093]

[Chemical formula 73]

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

[0095]

[Chemical 74]

[0096]

[Chemical 75]

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

[0098]

[Chemical 76]

[0099]

[Chemical 77]

[0100]

[Chemical 78]

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

[0102]

[Chemical 79]

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

[0104]

[Chemical 80]

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

[0106]

[Chemical 81]

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

[0108]

[Chemical formula 82]

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.

[0112]

[Chemical 83] p: 0-5 q: 2-11 integer may be optically active.

[0113]

[Chemical 84] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0114]

[Chemical 85] u: 0, 1 v: 1-16 integer

[0115]

[Chemical 86] w: 1 to 15 integer Optically active

[0116]

[Chemical 87] A: 0 to 2 B: 1 to 15 integer Optically active

[0117]

[Chemical 88] C: 0 to 2 D: 1 to 15 integer Optically active

[0118]

[Chemical 89]

[0119]

[Chemical 90]

[0120]

[Chemical Formula 91]

[0121]

[Chemical Formula 92]

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

[0123]

[Chemical formula 93]

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

[0125]

[Chemical 94]

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

[0127]

[Chemical 95]

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

[0129]

[Chemical 96]

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

[0131]

[Chemical 97]

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

[0133]

[Chemical 98]

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

[0135]

[Chemical 99]

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

[0137]

[Chemical 100] May be replaced with.

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

[0139]

[Chemical 101] p: 0-5 q: 2-11 integer may be optically active.

[0140]

[Chemical 102] r: 0 to 6 s: 0,1 t: 1 to 14 integer may be optically active.

[0141]

[Chemical 103] w: 1 to 15 integer Optically active

[0142]

[Chemical 104] A: 0 to 2 B: 1 to 15 integer Optically active

[0143]

[Chemical 105] C: 0 to 2 D: 1 to 15 integer Optically active

[0144]

[Chemical formula 106] Preferred compounds of formula (XIII) are (XIIIa)
To (XIIIc).

[0145]

[Chemical formula 107] More preferable compounds of (XIIIa) to (XIIIc) include (XIIIaa) to (XIIIch).

[0146]

[Chemical 108]

[0147]

[Chemical 109] Preferred compounds of (XIV) are (XIVa) to (XIVa
IVb).

[0148]

[Chemical 110]

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

[0150]

[Chemical 111] 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.

[0153]

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

[0154]

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

[0155]

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

[0156]

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

In the present invention, the proportion of the liquid crystal compound of the present invention in the liquid crystal composition is 1% by weight to 80% by weight, preferably 1% by weight to 60% by weight, more preferably 1% by weight to 40% by weight. Is desirable.

When two or more liquid crystal compounds of the present invention are used, the proportion of the mixture of two or more liquid crystal compounds of the present invention in the liquid crystal composition obtained by mixing is 1% by weight.
It is desirable that the amount is -80% by weight, preferably 1% by weight-60% by weight, and more preferably 1% by weight-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 liquid crystal layer exhibiting the ferroelectricity 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, the liquid crystal element has a liquid crystal layer 1 having a chiral smectic phase disposed between a pair of glass substrates 2 provided with a transparent electrode 3 and an insulating alignment control layer 4, respectively, and 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 or ITO (Indium Tin Oxide; Indium Tin O ₂₎ is provided on each of the two glass substrates 2.
The transparent electrode 3 made of a thin film such as xide) 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 or magnesium fluoride, and insulating layer is formed on it, 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 its precursor solution (0.1 to 20 in a solvent) is used.
% 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 5Å to 1
μm, preferably 10Å to 3000Å, more preferably 10Å 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.

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 liquid crystal molecules 2
Untwist the spiral structure of 3 and dipole moment (P⊥) 2
The liquid crystal molecules 23 can change the alignment direction so that all 4 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 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.

The image information is generated by the graphics controller 102 on the main body side, and transferred to the display panel 103 according to 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.

[0175]

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 6-octyl-2- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzothiazole (Exemplary Compound I-2) was produced according to the following steps.

[0177]

[Chemical formula 116]

(1) Synthesis of p-toluenesulfonic acid 3- (butyldimethylsilyl) propyl ester Butyldimethyl-3-hydroxypropylsilane 5.0
0 g (28.7 mmol) was dissolved in 15 ml of methylene chloride and stirred under ice cooling, and a solution of 6.56 g (34.4 mmol) of p-toluenesulfonyl chloride in 10 ml of pyridine was added dropwise over 15 minutes. After the dropping, the mixture was stirred at this temperature for 40 minutes and then at room temperature for 1 hour and 15 minutes. Ice water 100
It is poured into 10 ml of concentrated hydrochloric acid, and 10 ml of concentrated hydrochloric acid is added to make it acidic (pH ~
4), sodium chloride was added, and the mixture was extracted with methylene chloride. The methylene chloride layer was washed with saturated saline and then dried over anhydrous sodium sulfate. After filtering magnesium sulfate, the filtrate was concentrated to obtain 9.4 g of p-toluenesulfonic acid 3- (butyldimethylsilyl) propyl ester.

(2) Synthesis of 4-[(3-butyldimethylsilyl) propoxy] benzoic acid 4-hydroxybenzoic acid ethyl ester 2.60 g (1
5.6 mmol), potassium carbonate 4.36 g (31.5
mmol) and DMF (20 ml) were added, and p-toluenesulfonic acid 3- (butyldimethylsilyl) propyl ester 8.00 g (17.9 mmol) was stirred at an internal temperature of 100 ° C.
Was dripped in 8 minutes.

After the dropping, the mixture was stirred at 99 to 105 ° C. for 30 minutes. It was poured into about 100 ml of ice water, added with sodium chloride, and then extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate. After distilling off sodium sulfate, the filtrate was concentrated to dryness. A solution of 50 ml of ethanol and 2.10 g (31.8 mmol) of 85% potassium hydroxide in 15 ml of water was added thereto, refluxed for 30 minutes, and concentrated. Then water 150
ml was added, concentrated hydrochloric acid 3 ml was added, and the mixture was stirred at room temperature. After adding sodium chloride and stirring, the precipitated crystals were collected by filtration, washed with water and recrystallized from methanol to obtain 4.89 g of 4-[(3-butyldimethylsilyl) propoxy] benzoic acid. Yield 8
4.4%

(3) 6-octyl-2- [4- {3-
Synthesis of (butyldimethylsilyl) propoxy} phenyl] benzothiazole 4-[(3-Butyldimethylsilyl) propoxy] benzoic acid 2.00 g (6.79 mmol), thionyl chloride 2.3 ml, DMF 2 drops and reflux for 30 minutes. did. After refluxing, excess thionyl chloride was distilled off. Dry benzene was added, and the mixture was further distilled off to give 4-[(3-butyldimethylsilyl)
2.11 g of propoxy] benzoic acid chloride were obtained.

0.80 g (2.56 mmol) of the above acid chloride was added to 0.69 g (1.28 mmol) of zinc salt of 5-octyl-2-aminobenzenethiol to give 200-2.
The mixture was stirred at 05 ° C for 20 minutes. Add ethyl acetate and stir,
Brine was added, the organic layer was separated, and the aqueous layer was extracted with ethyl acetate and combined with the organic layer. The extract was washed with saturated saline and dried over anhydrous sodium sulfate. After filtering off sodium sulfate, the filtrate is concentrated and purified by silica gel column (developing solvent toluene).
did. Then, it was treated with activated carbon and recrystallized from acetone / methanol to obtain 0.81 g of 6-octyl-2- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzothiazole. Yield 63.7%

[0183]

[Equation 2]

Example 2 5-Undecanoyl-2- [4- {3-
(Butyldimethylsilyl) propoxy} phenyl] benzoxazole (Exemplary Compound I-4) was produced.

[0185]

[Chemical 117]

(1) 4-Undecanoyl-2- [4-
Synthesis of {3- (butyldimethylsilyl) propoxy} benzoylamino] phenol 2-amino-4-undecanoylphenol 0.50 g
(1.90 mmol), 4- [3- (butyldimethylsilyl) propoxy] benzoic acid chloride 0.64 g (2.1
mmol) and 8 ml of dioxane were added, and the internal temperature was 77-80.
0.64 ml of pyridine was added dropwise while maintaining the temperature at 0 ° C. and stirring with heating. After completion of dropping, the mixture was heated and stirred at an inner temperature of 82.5 to 83.5 ° C for 30 minutes. After the reaction was completed, the reaction product was cooled with ice and ice water was added to about 10
Opened in 0 ml. The precipitated crystals were collected by filtration, washed with water and then recrystallized from ethanol to give 4-undecanoyl-2-
0.92 g of [4- {3- (butyldimethylsilyl) propoxy} benzoylamino] phenol was obtained. Yield 8
7.5%.

(2) 5-Undecanoyl-2- [4-
Synthesis of {3- (butyldimethylsilyl) propoxy} phenyl] benzoxazole 4-undecanoyl-2- [4- {3- (butyldimethylsilyl) propoxy} benzoylamino] phenol 0.85 g (1.53 mmol), p- Toluenesulfonic acid monohydrate 0.06 g, o-dichlorobenzene 6 ml
Was added and the mixture was stirred at 200 to 204 ° C. for 38 minutes. After completion of the reaction, o-dichlorobenzene was distilled off under reduced pressure, the residue was purified by a silica gel column (developing solvent toluene), recrystallized with acetone, further treated with activated carbon, and then recrystallized from acetone.
0.55 g of -undecanoyl-2- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoxazole was obtained. Yield 66.9%.

[0188]

[Equation 3]

Example 3 5- (4-decylphenyl) -2- [4
-{3- (Butyldimethylsilyl) propoxy} phenyl] benzoxazole (Exemplary Compound I-38) was produced.

[0190]

[Chemical 118]

5- (4-decyl) was prepared in the same manner as in Example 2 except that 2-amino-4- (4-decylphenyl) phenol was used instead of 2-amino-4-undecanoylphenol. Phenyl) -2- [4- {3
-(Butyldimethylsilyl) propoxy} phenyl] benzoxazole was synthesized.

[0192]

[Equation 4]

Example 4 5- (5-dodecylpyrimidin-2-yl) -2- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoxazole (Exemplified Compound I
-47) was produced.

[0194]

[Chemical formula 119]

The procedure of Example 2 was repeated except that 2-amino-4- (5-dodecylpyrimidin-2-yl) phenol was used instead of 2-amino-4-undecanoylphenol. (5-Dodecylpyrimidin-2-yl) -2- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoxazole was synthesized.

[0196]

[Equation 5]

Example 5 5-Butyl-2- [4- [4- {3-
(Butyldimethylsilyl) propoxy} phenyl] phenyl] benzoxazole (Exemplary Compound I-90) was produced.

[0198]

[Chemical 120]

(1) Synthesis of 4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoic acid 4- (4-hydroxyphenyl) benzoic acid 2.00 g
(9.34 mmol), ethanol (50 ml) and concentrated sulfuric acid (1.5 ml) were added, the mixture was refluxed for 4 hours, and left overnight at room temperature. Under ice-water cooling, about 40 ml of water was added and stirred. The precipitated crystals were collected by filtration, washed with brine as an ethyl acetate solution, the aqueous layer was extracted with ethyl acetate, combined with the organic layer, and dried over anhydrous sodium sulfate. Sodium sulfate was filtered off and the filtrate was concentrated to dryness. Hexane was added to obtain 1.48 g of ethyl 4- (4-hydroxyphenyl) benzoate. Yield 65.4%.

4- (4-hydroxyphenyl) benzoic acid ethyl ester 1.45 g (5.99 mmol), potassium carbonate 1.67 g (12.1 mmol), DMF 9 m.
l, 3.07 g (6.89 mmol) of p-toluenesulfonic acid 3- (butyldimethylsilyl) propyl ester was added dropwise with stirring at an internal temperature of 95 to 100 ° C., and DMF was added.
Washed with 1 ml. After the dropping, the mixture was stirred for 40 minutes while keeping the internal temperature at 95 to 103 ° C. After completion of the reaction, the mixture was poured into ice water, sodium chloride was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated saline and then dried over anhydrous sodium sulfate. Sodium sulfate was filtered off and the filtrate was concentrated. The residue was recrystallized from acetone / methanol to give 4- [4- {3-
1.35 g of (butyldimethylsilyl) propoxy} phenyl] benzoic acid ethyl ester was obtained. Yield 56.6
%.

Next, 1.32 g (3.31 mmol) of 4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoic acid ethyl ester and ethanol 20 were added.
ml and 0.45 g of 85% potassium hydroxide (6.8 g)
5 mmol aqueous solution (2 mmol) was added, and the mixture was refluxed for 30 minutes and concentrated. Then, water was added, concentrated hydrochloric acid was added, and the mixture was stirred at room temperature. After adding sodium chloride and stirring, the precipitated crystals were collected by filtration, washed with water, and recrystallized from acetone to obtain 1.05 g of 4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoic acid. Yield 85.6%.

(2) 4-Butyl-2- [4- [4- {3
Synthesis of-(butyldimethylsilyl) propoxy} phenyl] benzoylamino] phenol 4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoic acid 1.00 g (2.70 mmo)
l), 1.5 ml of thionyl chloride and 2 drops of DMF were added, and 3
Reflux for 0 minutes. After refluxing, excess thionyl chloride was distilled off. Dry benzene was added, and the residue was distilled off to give 4- [4- {3
1.04 g of-(butyldimethylsilyl) propoxy} phenyl] benzoic acid chloride was obtained.

2-Amino-4-butylphenol 0.1
9 g (1.15 mmol), 4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoic acid chloride 0.50 g (1.20 mmol), dioxane 5 ml
, While maintaining the internal temperature at 78 to 80 ° C. while heating and stirring,
0.38 ml of pyridine was added dropwise. After the dropping, the internal temperature is 8
The mixture was heated and stirred at 2-83 ° C for 30 minutes. After completion of the reaction, the reaction product was ice-cooled and poured into about 80 ml of ice water. The precipitated crystals were collected by filtration to give an ethyl acetate solution and dried over anhydrous sodium sulfate. Sodium sulfate was filtered off and the filtrate was concentrated to dryness. Hexane was added, the crystals were collected by filtration, and 4-butyl-2-
[4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoylamino] phenol 0.50
g was obtained. Yield 84.0%.

(3) 5-Butyl-2- [4- [4- {3
Synthesis of-(butyldimethylsilyl) propoxy} phenyl] phenyl] benzoxazole 4-butyl-2- [4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] benzoylamino] phenol 0.66 g (1. 27 mmol), 0.05 g of p-toluenesulfonic acid monohydrate and 5 ml of o-dichlorobenzene were added, and the mixture was stirred at 200 to 204 ° C. for 30 minutes. After completion of the reaction, o-dichlorobenzene was distilled off under reduced pressure,
The residue is purified by silica gel column (developing solvent toluene / hexane = 1/1) and recrystallized from acetone to give 5-butyl-2- [4- [4- {3- (butyldimethylsilyl) propoxy} phenyl] phenyl]. 0.48 g of benzoxazole was obtained. Yield 75.3%.

[0205]

[Equation 6]

Example 6 A liquid crystal composition A was prepared by mixing the following compounds including the exemplified compound I-2 produced in Example 1 in the following parts by weight.

[0207]

[Chemical 121]

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

[0209]

[Equation 7]

Example 7 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.

[0211] 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.

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

The liquid crystal composition A mixed in Example 6 was injected into this cell in an isotropic liquid state and gradually cooled from the isotropic phase to 25 ° C. at 20 ° C./h to obtain a ferroelectric liquid crystal element. 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.

[0215]

[Table 1] 10 ° C. 30 ° C. 40 ° C. Response speed 201 μsec 91 μsec 59 μsec Ps 9.4 nC / cm ² 7.7 nC / cm ² 5.9 nC / cm ²

Example 8 The following compounds were mixed in the following parts by weight to prepare a liquid crystal composition B.

[0217]

[Chemical formula 122]

[0218]

[Chemical 123]

Further, the liquid crystal composition C was prepared by mixing the liquid crystal composition B with the following exemplary compounds in the respective weight parts shown below.

[0220]

[Chemical formula 124]

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

[0222]

[Table 2] 10 ° C 25 ° C 40 ° C Response speed 606 μsec 300 μsec 168 μsec

Comparative Example 1 A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that the liquid crystal composition B mixed in Example 8 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0224]

[Table 3] 10 ° C 25 ° C 40 ° C Response speed 784 μsec 373 μsec 197 μsec

Example 9 Exemplified compounds I-1, I-5, I-3 used in Example 8
Liquid crystal composition D was prepared by mixing the following exemplary compounds in place of 3 with the respective weight parts shown below.

[0226]

[Chemical 125]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0228]

[Table 4] 10 ° C 25 ° C 40 ° C Response speed 638 μsec 312 μsec 173 μsec

Example 10 Exemplified Compounds I-1, I-5 and I-3 used in Example 8
Instead of 3, the following exemplary compounds were mixed in the respective weight parts shown below to prepare a liquid crystal composition E.

[0230]

[Chemical formula 126]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0232]

[Table 5] 10 ° C 25 ° C 40 ° C Response speed 691 μsec 316 μsec 181 μsec

Example 11 A liquid crystal composition F was prepared by mixing the following compounds in the following parts by weight.

[0234]

[Chemical 127]

[0235]

[Chemical 128]

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

[0237]

[Chemical formula 129]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that the liquid crystal composition G was injected into the cell.
The optical response speed was measured to observe the switching state and the like. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0239]

[Table 6] 10 ° C. 25 ° C. 40 ° C. Response speed 577 μsec 282 μsec 145 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 7 except that the liquid crystal composition F mixed in Example 11 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0242]

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

Example 12 Exemplified compounds I-59, I-76 used in Example 11,
A liquid crystal composition H was prepared by mixing the following exemplary compounds in place of I-79 in the respective weight parts shown below.

[0244]

[Chemical 130]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

[0247]

[Table 8] 10 ° C 25 ° C 40 ° C Response speed 515 μsec 256 μsec 136 μsec

Example 13 Exemplified compounds I-59, I-76 used in Example 11
Liquid crystal composition I was prepared by mixing the following exemplary compounds in place of I-79 in the respective weight parts shown below.

[0249]

[Chemical 131]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

[0252]

[Table 9] 10 ° C 25 ° C 40 ° C Response speed 543 μsec 271 μsec 139 μsec

Example 14 Liquid Crystal Composition J was prepared by mixing the following compounds in the following parts by weight.

[0254]

[Chemical 132]

[0255]

[Chemical 133]

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

[0257]

[Chemical 134]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

[0260]

[Table 10] 10 ° C 25 ° C 40 ° C Response speed 532 μsec 280 μsec 158 μsec

Comparative Example 3 A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that the liquid crystal composition J mixed in Example 14 was injected into the cell, and the optical response speed was measured. The measurement results are shown below.

[0262]

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

Example 15 Exemplified compounds I-27, I-36 used in Example 14
Instead of I-45, the following exemplary compounds were mixed in the respective weight parts shown below to prepare a liquid crystal composition L.

[0264]

[Chemical 135]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

[0267]

[Table 12] 10 ° C 25 ° C 40 ° C Response speed 599 μsec 308 μsec 170 μsec

Example 16 Exemplified compounds I-27, I-36 used in Example 14
Liquid crystal composition M was prepared by mixing the following exemplary compounds in place of I-45 in the respective weight parts shown below.

[0269]

[Chemical 136]

A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that this liquid crystal composition was used, the optical response speed was measured, and the switching state and the like were observed. The uniform alignment in this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

[0272]

[Table 13] 10 ° C 25 ° C 40 ° C Response speed 563 μsec 295 μsec 164 μsec

As is clear from Examples 8 to 16, the ferroelectric liquid crystal device containing the liquid crystal compositions C, D, E, G, H, I, K, L and M according to the present invention operates at a low temperature. The characteristics and high-speed response are improved, and the temperature dependence of response speed is also reduced.

Example 17 Except that the polyimide resin precursor 1.5% dimethylacetamide solution used in Example 8 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.

[0275]

[Table 14] 10 ° C 25 ° C 40 ° C Response speed 587 μsec 291 μsec 164 μsec

Example 18 A ferroelectric liquid crystal device was prepared in the same manner as in Example 7 except that the alignment control layer was prepared only by using a polyimide resin without using the SiO ₂ used in Example 8, and then implemented. The optical response speed was measured in the same manner as in Example 7. The measurement results are shown below.

[0277]

[Table 15] 10 ° C 25 ° C 40 ° C Response speed 576 μsec 287 μsec 162 μsec

As is clear from Examples 17 and 18, the device containing the ferroelectric liquid crystal composition according to the present invention, even when the device structure was changed, was much improved in low temperature operation characteristics as in Example 8. In addition, the temperature dependence of the response speed is reduced.

[0279]

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 element of the present invention is used as a display element in combination with a light source, a driving 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 front page (72) Inventor Yoko Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shinichi Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (31)

[Claims] 1. A liquid crystal compound represented by the following general formula (I). [Chemical 1] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S, and A ₁ , A ₂ , A ₃
Is And Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br,
CH ₃ , CN or CF ₃ . Z ₁ and Z ₂
Is a single bond, -COO -, - OCO -, - CH 2 O- or -OCH ₂ - indicates, _{Z 3} is -O -, - CO-,
-COO- or -OCO- is shown. R ₃ , R ₄ ,
R ₅ is a linear or branched alkyl group having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is replaced with —O—, —COO—, —OCO—. May be. p and q are 0 or 1. n
Represents an integer of 1 to 12. ) 2. The liquid crystal compound according to claim 1, wherein the liquid crystal compound represented by the general formula (I) is any of the following [Ia] to [Ic]. [Chemical 4] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S, and A ₁ , A ₂ , A ₃
Is And Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br,
CH ₃ , CN or CF ₃ . Z ₁ and Z ₂
Is a single bond, -COO -, - OCO -, - CH 2 O- or -OCH ₂ - indicates, _{Z 3} is -O -, - CO-,
-COO- or -OCO- is shown. R ₃ , R ₄ ,
R ₅ is a linear or branched alkyl group having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is replaced with —O—, —COO—, —OCO—. May be. n represents an integer of 1 to 12. ) 3. The liquid crystal compound according to claim 1, wherein the liquid crystal compound represented by the general formula (I) is any of the following [Iaa] to [Ich]. [Chemical 7] [Chemical 8] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, and the hydrogen atom may be substituted with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S. Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br, CH ₃ , CN or CF ₃ . Z ₃ is -O-, -CO-, -COO- or-
Indicates OCO-. R ₃ , R ₄ , and R ₅ are linear or branched alkyl groups having 1 to 18 carbon atoms, and the methylene group not adjacent to the hetero atom in the alkyl group is -O-, -COO-, It may be replaced by -OCO-. n represents an integer of 1 to 12. ) 4. In the general formula (I), R ₁ , R
₂ is any of the following (i) to (v):
The liquid crystal compound described. [Chemical 10] (In the formula, L is an integer of 3 to 17, m, r, and y are integers of 0 to 7, n, t, and x are integers of 1 to 8, s is 0 or 1, and a is an integer of 1 to 15. In addition, Z ₄ is a single bond, Indicates. R ₃ , R ₄ , and R ₅ have 1 to 18 carbon atoms
Is a linear or branched alkyl group, and the methylene group which is not adjacent to the hetero atom in the alkyl group is -O-,
It may be replaced with -COO- or -OCO-. Z ₃
Represents -O-, -CO-, -COO- or -OCO-. n1 represents an integer of 1 to 12. ) 5. In the general formula (I), R ₃ , R ₄ ,
The liquid crystal compound according to claim 1, wherein at least two of R ₅ are methyl groups. 6. The liquid crystal compound according to claim 1, wherein the liquid crystal compound of the general formula (I) is an optically active compound. 7. The liquid crystal compound according to claim 1, wherein the liquid crystal compound of the general formula (I) is a non-optically active compound. 8. A liquid crystal composition comprising at least one liquid crystal compound according to claim 1. 9. The liquid crystal composition according to claim 8, wherein the liquid crystal compound represented by the general formula (I) is contained in an amount of 1 to 80% by weight based on the liquid crystal composition. 10. The liquid crystal composition according to claim 8, wherein the liquid crystal compound represented by formula (I) is contained in an amount of 1 to 60% by weight based on the liquid crystal composition. 11. The liquid crystal composition according to claim 8, wherein the liquid crystal compound represented by the general formula (I) is contained in an amount of 1 to 40% by weight based on the liquid crystal composition. 12. The liquid crystal composition according to claim 8, wherein the liquid crystal composition has a chiral smectic phase. 13. A liquid crystal device comprising the liquid crystal composition according to claim 8 disposed between a pair of electrode substrates. 14. The liquid crystal element according to claim 13, wherein an alignment control layer is provided on the electrode substrate. 15. The liquid crystal device according to claim 14, wherein the alignment control layer is a layer subjected to a rubbing treatment. 16. The liquid crystal device according to claim 13, 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. 17. A display device comprising the liquid crystal element according to claim 13. 18. The display device according to claim 17, further comprising a drive circuit for the liquid crystal element. 19. The display device according to claim 17, further comprising a light source. 20. A display method using a liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I). [Chemical 12] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S, and A ₁ , A ₂ , A ₃
Is And Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br,
CH ₃ , CN or CF ₃ . Z ₁ and Z ₂
Is a single bond, -COO -, - OCO -, - CH 2 O- or -OCH ₂ - indicates, _{Z 3} is -O -, - CO-,
-COO- or -OCO- is shown. R ₃ , R ₄ ,
R ₅ is a linear or branched alkyl group having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is replaced with —O—, —COO—, —OCO—. May be. p and q are 0 or 1. n
Represents an integer of 1 to 12. ) 21. The display method according to claim 20, wherein the liquid crystal compound represented by the general formula (I) is any one of the following [Ia] to [Ic]. [Chemical 15] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S, and A ₁ , A ₂ , A ₃
Is And Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br,
CH ₃ , CN or CF ₃ . Z ₁ and Z ₂
Is a single bond, -COO -, - OCO -, - CH 2 O- or -OCH ₂ - indicates, _{Z 3} is -O -, - CO-,
-COO- or -OCO- is shown. R ₃ , R ₄ ,
R ₅ is a linear or branched alkyl group having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is replaced with —O—, —COO—, —OCO—. May be. n represents an integer of 1 to 12. ) 22. The display method according to claim 20, wherein the liquid crystal compound represented by the general formula (I) is any of the following [Iaa] to [Ich]. [Chemical 18] [Chemical 19] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S. Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br, CH ₃ , CN or CF ₃ . Z ₃ is -O-, -CO-, -COO- or-
Indicates OCO-. R ₃ , R ₄ , and R ₅ are linear or branched alkyl groups having 1 to 18 carbon atoms, and the methylene group not adjacent to the hetero atom in the alkyl group is -O-, -COO-, It may be replaced by -OCO-. n represents an integer of 1 to 12. ) 23. In the general formula (I), R ₁ ,
The display method according to claim 20, wherein R ₂ is any of the following (i) to (v). [Chemical 21] (In the formula, L is an integer of 3 to 17, m, r, and y are integers of 0 to 7, n, t, and x are integers of 1 to 8, s is 0 or 1, and a is an integer of 1 to 15. In addition, Z ₄ is a single bond, Indicates. R ₃ , R ₄ , and R ₅ have 1 to 18 carbon atoms
Is a linear or branched alkyl group, and the methylene group which is not adjacent to the hetero atom in the alkyl group is -O-,
It may be replaced with -COO- or -OCO-. Z ₃
Represents -O-, -CO-, -COO- or -OCO-. n1 represents an integer of 1 to 12. ) 24. The display method according to claim 20, wherein in the liquid crystal compound represented by the general formula (I), at least two of R ₃ , R ₄ and R ₅ are methyl groups. 25. The display method according to claim 20, wherein the liquid crystal compound of the general formula (I) is an optically active compound. 26. The display method according to claim 20, wherein the liquid crystal compound of the general formula (I) is a non-optically active compound. 27. The display method according to claim 20, wherein the liquid crystal compound represented by formula (I) is contained in an amount of 1 to 80% by weight based on the liquid crystal composition. 28. The display method according to claim 20, wherein the liquid crystal compound represented by formula (I) is contained in an amount of 1 to 60% by weight based on the liquid crystal composition. 29. The display method according to claim 20, wherein the liquid crystal compound represented by the general formula (I) is contained in an amount of 1 to 40% by weight based on the liquid crystal composition. 30. The display method according to claim 20, wherein the liquid crystal composition has a chiral smectic phase. 31. A display method using a liquid crystal element in which a liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I) is arranged between a pair of electrode substrates. [Chemical formula 23] (In the formula, R ₁ and R ₂ are a linear or branched alkyl group having 1 to 18 carbon atoms, and
Two methylene groups that are not adjacent to each other are -O-,
It may be substituted with -S-, -CO-, -COO-, -OCO-, or the hydrogen atom may be replaced with a fluorine atom. However, _one of R ₁ and R ₂ is And the other may be a hydrogen atom, halogen, or CN. X represents O or S, and A ₁ , A ₂ , A ₃
Is And Y ₁ and Y ₂ are hydrogen atoms, F, Cl, Br,
CH ₃ , CN or CF ₃ . Z ₁ and Z ₂
Is a single bond, -COO -, - OCO -, - CH 2 O- or -OCH ₂ - indicates, _{Z 3} is -O -, - CO-,
-COO- or -OCO- is shown. R ₃ , R ₄ ,
R ₅ is a linear or branched alkyl group having 1 to 18 carbon atoms, and the methylene group which is not adjacent to the hetero atom in the alkyl group is replaced with —O—, —COO—, —OCO—. May be. p and q are 0 or 1. n
Represents an integer of 1 to 12. )