JPH0228290A - Liquid crystal composition and liquid crystal element containing the same composition - Google Patents

Abstract

PURPOSE:To provide a ferroelectric chiral smectic liquid crystal composition containing two specific kinds of compounds, having good switching characteristics and large driving voltage margin and capable of keeping the image in good stage even if the display area of the element has a temperature distribution. CONSTITUTION:The objective composition contains (A) at least one kind of the compound of formula I [R1 is 1-18C (substituted) alkyl; R2 is 1-14C (substituted) alkyl; X1 and X2 are single bond, -O-, -OC(O)- or -C(O)O-; m is 0-7; n is 0 or 1] (e.g., the compound of formula II) and (B) at least one kind of the compound of formula III [R3 and R4 are R1; X3 and X4 are single bond, -O-, -OC(O)-, -C(O)O- or -OC(O)O-; Y1 is -CH2O- or -OCH2-; p and q are 1 or 2] (e.g., the compound of formula IV).

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a liquid crystal composition used for liquid crystal elements used in liquid crystal display elements, liquid crystal light shutters, etc. This invention relates to a liquid crystal composition.

[Background technology]

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, those described in "Applied Physics Letters" by M, 5chadt and W, He1frich.
Vo, 18, No. 4 (1971, 2, 15), P
, 127-128 “Voltage-3 penden
t 0ptical Activity of
aTwisted Nematic Liqui
d T N (t w i
S T E D N E M A T I C )
It uses a type of liquid crystal.

These are based on the dielectric alignment effect of liquid crystals, and utilize the effect that the average molecular axis direction is oriented in a specific direction due to the dielectric anisotropy of liquid crystal molecules due to an applied electric field. The optical response speed limit of these devices is said to be milliseconds, which is too slow for many applications. On the other hand, for application to large flat displays, driving by a simple matrix method is the most promising in terms of cost, productivity, etc. In the simple matrix method, an electrode configuration is adopted in which a scanning electrode group and a signal electrode group are arranged in a matrix.
To drive this, a time-division drive method is adopted in which address signals are selectively and periodically applied to the scanning electrode group, and predetermined information signals are selectively applied in parallel to the signal electrode group in synchronization with the address signal. be done.

However, if the above-mentioned TN type liquid crystal is used as an element of such a driving method, there will be an area where the scanning electrode is selected and the signal electrode is not selected, or an area where the scanning electrode is not selected and the signal electrode is selected (the so-called "half area"). A finite electric field is also applied to the selected point ("). If the difference between the voltage applied to the selected point and the voltage applied to the half-selected point is sufficiently large, and the voltage threshold required to align the liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage value, the display element will It works normally, but if you increase the number of scanning lines (N), the entire screen (
The time during which an effective electric field is applied to one selected point (duty ratio) decreases at a rate of 1/N while scanning 1 frames). For this reason, (the voltage difference as an effective value applied to the selected point and non-selected point when repeated scanning is performed is
As the number of scanning lines increases, the size becomes smaller, resulting in unavoidable drawbacks such as a reduction in image contrast and crosstalk.

This phenomenon is caused by liquid crystals that do not have bistability (the stable state is when the liquid crystal molecules are aligned horizontally with respect to the electrode surface, and they are aligned vertically only when an electric field is effectively applied). ) is essentially an unavoidable problem that arises when driving using the temporal accumulation effect (that is, repeatedly scanning). In order to improve this point, voltage averaging method, dual-frequency driving method, multiple matrix method, etc. have already been proposed, but all of these methods are insufficient, and it is necessary to increase the screen size and density of display elements. Currently, the number of scanning lines has reached a plateau due to the inability to increase the number of scanning lines sufficiently.

In order to improve the drawbacks of conventional liquid crystal elements, the use of bistable liquid crystal elements has been proposed for C1ark and L
proposed by Hgerwall (Japanese Unexamined Patent Publication No. 1983-
107216, US Pat. No. 4,367,924, etc.). As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral metal C phase (SmC*) or H phase (SmH*) is generally used. This ferroelectric liquid crystal has a bistable state consisting of a first optically stable state and a second optically stable state in response to an electric field, and therefore is different from the optical modulation element used in the above-mentioned TN type liquid crystal. Differently, for example, the liquid crystal is oriented in a first optically stable state with respect to one electric field vector, and the liquid crystal is oriented in a second optically stable state with respect to the other electric field vector. Further, this type of liquid crystal has a property (bistability) of taking one of the above two stable states in response to an applied electric field and maintaining that state when no electric field is applied.

In addition to the above-mentioned feature of bistability, ferroelectric liquid crystals have the excellent feature of high-speed response. This is because the spontaneous polarization of the ferroelectric liquid crystal and the applied electric field directly act to induce a transition in the orientation state, which is 3 to 4 orders of magnitude faster than the response speed due to the effect of the dielectric anisotropy and the electric field.

In this way, ferroelectric liquid crystals potentially have extremely excellent properties, and by utilizing these properties, many of the problems of conventional TN-type devices mentioned above can be overcome, which is quite essential. Improvement can be obtained.

In particular, it is expected to be applied to high-speed optical shutters and high-density, large-screen displays.

In the case of a simple matrix display device as described above using an element in which this ferroelectric liquid crystal layer is sandwiched between a pair of substrates, for example, Japanese Patent Laid-Open Nos. 59-193426 and 59-193 disclose
No. 427, No. 60-156046 and No. 60-
The driving method disclosed in Japanese Patent No. 156047 and the like can be applied.

FIG. 4 is a waveform diagram of the driving method used in the embodiment of the present invention. Further, FIG. 5 is a plan view of a ferroelectric liquid crystal panel 51 on which matrix electrodes used in the present invention are arranged. Fifth
In the panel 51 shown in the figure, a scanning line 52 and a data line 53 are wired to cross each other, and a ferroelectric liquid crystal is disposed between the scanning line 52 and the data line 53 at the intersection.

In FIG. 4(A), Ss is the selection scanning waveform applied to the selected scanning line, SN is the unselected scanning waveform, and 18 is the selection information waveform (black) applied to the selected data line. ), IN represents a non-selection information signal (white) applied to an unselected data line. Also, in the figure (rs
ss) and (IN ss) are the voltage waveforms applied to the pixels on the selected scanning line, the pixels to which the voltage (Is ss) is applied take a black display state, and the voltage (IN ss) is applied to the pixels on the selected scanning line.
The pixel to which s) is applied assumes a white display state.

FIG. 4(B) is a time series waveform when the display shown in FIG. 6 is performed using the drive waveform shown in FIG. 4(A).

In the driving example shown in FIG. 4, the minimum application time Δt of the unipolar voltage applied to the pixels on the selected scanning line corresponds to the time of the write phase t2, and the time of the 6th phase on the 1st line clear corresponds to 2. It is set to Δt.

Now, each parameter v51 of the drive waveform shown in FIG.
The value of vI +Δt is determined by the switching characteristics of the liquid crystal material used.

FIG. 7 shows the change in transmittance T, that is, the V-T characteristic, when the drive voltage (Vs+V+) is changed while keeping the bias ratio constant, which will be described later.

Cocoteha, △t=50μs, bias ratio Vx/(Vz+
V, )=1/3. The positive side of Figure 7 is the 4th
The waveform shown in the figure (IN ss) and the negative side (IsSS) are applied. Here, vl.

v3 are called an actual drive threshold voltage and a crosstalk voltage, respectively. However, V2<V, <V3) and △V”(v3
vI) is called a voltage margin and is a voltage width that allows matrix drive. It can be said that v3 generally exists in FLC matrix drive.

Specifically, it is the voltage value that causes switching due to VB in the waveform of FIG. 4(A) (IN SS).

Of course, it is possible to increase the value of v3 by increasing the bias ratio, but increasing the bias ratio means thickening the amplitude of the information signal, which may lead to an increase in flickering and an increase in image quality. This is undesirable because it causes a decrease in contrast. In our study, a bias ratio of about 1/3 to 1/4 was practical. By the way, if the bias ratio is fixed, the voltage margin △V is strong against the switching characteristics of the liquid crystal material. (It goes without saying that a liquid crystal material with a large ΔV is very advantageous for matrix driving.

At a certain temperature like this, it is possible to write two states, "black" and "white", into the selected pixel by changing the two directions of the information signal, and unselected pixels can write the "black" or "white" state into the selected pixel. The upper and lower limits of the applied voltage that can maintain this state and their widths (driving voltage margin ΔV) differ between liquid crystal materials and are unique. In addition, the drive margin also changes due to changes in the environmental temperature, so in the case of actual display devices, it is necessary to set the drive voltage to the optimum value for the liquid crystal material and the environmental temperature.

However, in practice, when expanding the display area of such a matrix display device, the difference in the environment in which the liquid crystal exists in each pixel (specifically, the temperature and the cell gap difference between electrodes) naturally increases, and the driving With liquid crystals that have a small voltage margin, it is not possible to obtain a good image over the entire display area.

[Problem that the invention seeks to solve]

In order to put ferroelectric liquid crystal elements into practical use, the present invention has a large drive voltage margin and a drive temperature margin that allows all pixels to be satisfactorily matrix driven even if there is some degree of temperature variation in the display area of the liquid crystal element. An object of the present invention is to provide a chiral smectic liquid crystal composition with a wide range of properties and a liquid crystal element using the liquid crystal composition.

[Means for solving the problem] The present invention is based on the following general formula (1) (wherein R1 is a linear or branched alkyl group which may have a C1 to C+S substituent, and R2 is a C1 ~C
A linear or branched alkyl group which may have a substituent as I4, R4 is a straight-chain or branched alkyl group that may have a substituent of CI "" CI8, Yl
is -CH2〇- or -〇〇R2-1p.

Provided is a ferroelectric chiral smectic liquid crystal composition, characterized in that q contains l or at least one of the compounds represented by 2), and a liquid crystal element in which the liquid crystal composition is disposed between a pair of electrode substrates. It is something to do.

Among the compounds represented by the above-mentioned general formula (I), as a preferable compound example, X I + I2 is the following (1-i)
-(I-iv) can be mentioned.

(I-i)X, is a single bond, I2 is -〇-
(1-4i) Xr is a single bond, I2 is -0
C-(1-4ii)X, is a single bond, I2 is -CaI2 (1-iv)X, is -0-1x2 is 10-, and RI +
A more preferable example of R2 is a linear alkyl group having 1 to 14 carbon atoms.

Among the compounds represented by the above-mentioned general formula (II), preferred compound examples include the following (na) to (II).
-f) Compounds represented by the formula are mentioned.

R3-X3-◎-CH20-◎-X4-R4R3-X3
-◎-〇CH2-◎-X4-R4R3-X3-◎-CH
20-◎-◎-X4-R4R3-X3-◎-〇CH2O
→◎−◎−X4−R4R3−X3←[Yes]−◎−CH2
0-◎-X4-R4R3-X3-◎←u-OCH2-◎
-X4-R4(ra) (I-b) (1-c) (1-d) (1-e) (1-f) Furthermore, the above (II-a) to (n-f) X3 in the formula. A preferable example of X4 is (II -i
) to (II-viii).

x3 is a single bond, X4 is a single bond, x3 is a single bond, x4 is -〇-X3 is a single bond, X4
is -CO-(1-i) (I-ii) (I-iii) is a single bond, X4 is 10C- (I-iv) is 10-1 10-1 X4 is a single bond 10- -ix
) to (II-xiii).

H3 (II-ix) RB is n-alkyl group, R4 is -GCH2), CHR.

* (p is 0 to 7, R5 is a linear or branched alkyl group) (p.

q is θ~7, R5+ 6 is linear or branched alkyl group) (If-xi) R is an n-alkyl group.

(r is 1 to 12) (II-xii) R.B. is an n-alkyl group.

(S is 0 to 7, t is O or 11, and R7 is a linear or branched alkyl group) Examples of specific structural formulas of the liquid crystal compound represented by the general formula (1) are shown below.

A typical synthesis example of the compound represented by the general formula (I) is shown below.

Synthesis Example 1 (Synthesis of compound No. 1-20) 1.06 5-methoxyhexanol dissolved in 5 ml of pyridine
g (8.0 mmol) of 1.83 g of p-)luenesulfonic acid chloride dissolved in 5 mj2 of pyridine (
9.6 mmol) was added dropwise at 5° C. or lower in ice water. After stirring for 6 hours at room temperature, the reaction mixture was poured into 100 mj' of cold water. After making the mixture acidic with 6N hydrochloric acid, the mixture was extracted with isopropyl ether. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and then the solvent was distilled off to obtain 5-methoxyhexyl-p-toluenesulfonate.

10mj of dimethylformamide? 5-decyl-2-(
p-hydroxyphenyl)pyrimidine 2.0g (6,4
1 mmol), add 0.61 g of potassium hydroxide, and add io
.

Stirred at ℃ for 40 minutes. To this was added the previously obtained 5-methoxyhexyl-p-toluenesulfonate, and the mixture was heated at 100°C.
The mixture was heated and stirred at C for 4 hours. After the reaction was completed, the reaction mixture was poured into 100 mj' of cold water and extracted with benzene. After washing with water, it was dried over anhydrous magnesium sulfate and the solvent was distilled off to obtain a pale yellow oil. After purification by column chromatography (silica gel-ethyl acetate/benzene = 179), it was recrystallized from hexane to give 5-decyl-2-(4
1.35 g of -(5'-methoxyhexyloxy)phenyl)pyrimidine (exemplified compound No. 21) was obtained.

Phase transition temperature ('C) Synthesis Example 2 (Synthesis of compound No. 1-25) 2.04 g of 6-pentyloxyheptanol was added to 8 m of pyridine!
! After cooling with water, 2.26 g of tosyl chloride dissolved in 5 m4 of pyridine was gradually added dropwise (below 50C, 7 minutes). Thereafter, the mixture was stirred at room temperature for 5 hours.

The reaction mixture was poured into 150mj7 of ice water, adjusted to pH approximately 3 with 6N aqueous hydrochloric acid solution, and then extracted with ethyl acetate.

After washing this with water and drying it with anhydrous magnesium sulfate,
The solvent was distilled off to obtain 2.98 g of (6-pentyloxyheptyl)p-)luenesulfonate.

3.12 g of 5-n-decyl-2-(4-hydroxyphenyl)pyrimidine and 0.53 g of potassium hydroxide were dissolved in 14 mf of dimethylformamide, heated and stirred at 100°C for 3 hours, and then (6-pentyloxyheptyl)p −
2.98 g of toluene sulfonate was added, and the mixture was heated and stirred at 100° C. for 5 hours.

Pour the reaction mixture into 200mj of ice water! After adjusting the pH to about 3 with a 6N aqueous hydrochloric acid solution, the mixture was extracted with benzene. This was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain 4.71 g of a crude product. This was purified by silica gel column chromatography (n-hexane/ethyl acetate=1O/2
) After that, it was further recrystallized from hexane to obtain 1.56 g of 5-n-decyl-2-[4-(6-pentyloxyhebutyloxy)phenylcopyrimidine.

I R (cm-I) 2924.2852, 1610, 1586, 1472° 1436.1254, 1168, 1096. 798 Phase transition temperature (°C) Synthesis route A is also used for compounds other than those on the synthesis side.

It can be obtained by B.

Synthetic route A Synthetic route B (In the above R , R2,X , m, and n are as described above. ) The above general formula The specific structure of the compound shown in An example of the construction formula is shown below.

2-6B The compound represented by the above general formula (I) is, for example, disclosed in JP-A No. 6
0-149547 (1985), JP-A-6L-63
633 (1986).

Typical synthesis examples are shown below.

Synthesis Example 1 (Synthesis of Compound No. 2-54) 30 m j
! Place 1.0 g of the following alcohol derivative in an eggplant flask.
(4,81 m m o 1) was added under cooling, 3 mj7 of thionyl chloride was added, the temperature was raised to room temperature while stirring, and a cooling pipe was attached, and the external temperature was 700 C to 80 C.
Heat reflux was performed for a period of time. After the reaction, excess thionyl chloride was distilled off to obtain a chloride. This was dissolved in 15 ml of toluene.

Next 200m I! Put 0.33 g of 60% oily sodium hydride into a three-necked flask, wash it several times with dry n-hexane, and add 1.52 g of the following phenol derivative (4,
81 mmol) in THF solution 15 m j! was added dropwise at room temperature, and 20 m ji' of DMSO was further added and stirred for 1 hour. To this, the toluene solution of the chloride mentioned above was slowly added dropwise, and after the dropwise addition was completed, stirring was continued for 16 hours at room temperature.

After the reaction was completed, the organic layer was poured into ice water at about 200 mf, the organic layer was separated, and the aqueous layer was extracted twice with 50 mj2 of benzene. After washing with the previously separated organic layer twice with a 5% aqueous hydrochloric acid solution, the ions were removed. After washing once with exchanged water and once with 5% NaOH aqueous solution, the organic layer was washed with ion-exchanged water until the pH value of the aqueous layer became neutral.

The organic layer was taken out, dried using magnesium sulfate, and the solvent was distilled off to obtain a crude product. Add this to the developing solution n-hexane/
Purification was performed by silica gel column chromatography using dichloromethane, 3/1O.

The crystals obtained by distilling off the solvent were recrystallized using n-hexane to obtain the purified target product. Further, the product was dried under reduced pressure at room temperature to obtain 0.69 g of the final purified target product. The yield was 28.5%.

Elemental analysis value (wt%) Calculated value Measured value 78.33 78.96 8.57 8.69 0.00 0.02 Phase transition synthesis example 2 (synthesis of compound No. 2-68) 30 mI! Place 1.25g of the following alcohol derivative in an eggplant flask (4,
01 mmol) was added thereto, 4 ml of thionyl chloride was added under cooling, the temperature was raised to room temperature while stirring, a cooling tube was attached, and the mixture was heated under reflux at an external temperature of 70'C to 80'C for 4 hours. After the reaction, excess thionyl chloride was distilled off to obtain a chloride. This was dissolved in 15mf of toluene.

Next 200m! ! Put 60% oily sodium hydride O, ATG into a three-necked flask, wash it several times with dry n-hexane, and then add 0.79 g (4
, 01 mmol) was soaked at room temperature, 20 mj2 of DMSO was added, and the mixture was stirred for 1 hour. To this, the toluene solution of the chloride mentioned above was slowly added dropwise, and after the dropwise addition was completed, stirring was continued for 16 hours at room temperature.

After the reaction was completed, the mixture was poured into about 200 rrl of ice water, the organic layer was separated, and the aqueous layer was extracted twice with 50 ml of benzene.
The previously separated organic layer was washed twice with a 5% aqueous hydrochloric acid solution, then once with ion-exchanged water, and then once with a 5% aqueous NaOH solution, and then washed with ion-exchanged water until the pH value of the aqueous layer became neutral. The organic layer was washed with water.

The organic layer was taken out, dried using magnesium sulfate, and the solvent was distilled off to obtain a crude product. Add this to the developing solution n-hexane/
Purification was performed by silica gel column chromatography using dichloromethane, 3/1O.

The crystals obtained by distilling off the solvent were recrystallized using n-hexane to obtain the purified target product. Further, the product was dried under reduced pressure at room temperature to obtain 0.51 g of the final purified target product.

was 26.0%.

CHN analysis value (wt%) CHN calculated value 7B, 33 8,63 0.00
Theoretical value 78.62 8,86 0.02 Phase transition yield IR spectrum 2975° 1510° 1280° 1020° S2 53 2925° 1470° 1240° 1000° is unidentified 2850, 1610° 1380, 1295° 122 0, 1130 810 cm-' The liquid crystal composition of the present invention comprises at least one compound represented by the general formula (1), at least one compound represented by the general formula (II), and another liquid crystal compound. It can be obtained by mixing one or more types in an appropriate ratio. Further, the liquid crystal composition according to the present invention is preferably a ferroelectric liquid crystal composition, particularly a ferroelectric chiral smectic liquid crystal composition.

Specific examples of other liquid crystal compounds used in the present invention are listed below.

(Less than 1 margin below) 1-. 1'+i-~ B'l'i'U Cl0H210+CO3+ OCH2CHOC,H7nep υ υ (blank below) ,', -, -? l+-,L Each of the liquid crystalline compounds represented by the general formula (1) and the liquid crystalline compound represented by the general formula (II) of the present invention, and one or more of the other liquid crystalline compounds mentioned above, or a ferroelectric compound containing the same. The orientation ratio of each of the liquid crystal compounds represented by the general formula (1) and general formula (II) of the present invention per 100 parts by weight of the ferroelectric liquid crystal material (hereinafter abbreviated as ferroelectric liquid crystal material) is It is preferable that the amount is 1 to 300 parts by weight, more preferably 5 to 100 parts by weight.

Furthermore, when using two or more of one or both of the liquid crystal compounds represented by the general formula (1) and general formula (II) of the present invention, the blending ratio with the ferroelectric liquid crystal material is as described above. General formula (I) of the present invention per 100 parts by weight
and 1 to 500 parts by weight of a mixture of two or more of one or both of the liquid crystalline compounds represented by general formula (II),
More preferably, the amount is 10 to 100 parts by weight.

FIG. 1 is a schematic cross-sectional view of an example of a liquid crystal element having a ferroelectric liquid crystal layer according to the present invention, for explaining the structure of the ferroelectric liquid crystal element.

In FIG. 1, the symbol l is a ferroelectric liquid crystal layer, 2 is a glass substrate, 3 is a transparent electrode, 4 is an insulating alignment control layer, 5 is a spacer, 6 is a lead wire, 7 is a power source, 8 is a polarizing plate, 9 indicates a light source.

The two glass substrates 2 each have an I n 203 r
Sn02 or ITO (Indium-Tin 0
A transparent electrode made of a thin film such as xide) is coated. On top of this, a thin film of a polymer such as polyimide is rubbed with gauze or acetate flocked cloth to form an insulating alignment control layer that aligns the liquid crystals in the rubbing direction. Insulating materials such as silicon nitride, hydrogen-containing silicon carbide, silicon oxide, boron nitride, hydrogen-containing boron nitride, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide, and fluoride Form an insulating layer of inorganic material such as magnesium, and then apply polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin. The insulating alignment control layer may be formed of two layers using an organic insulating material such as melamine resin, Yulia resin, acrylic resin, or photoresist resin as the alignment control layer (
Alternatively, it may be a single layer of an insulating orientation control layer of an inorganic material or an insulating orientation control layer of an organic material. If this insulating alignment control layer is inorganic, it can be formed by a vapor deposition method, or if it is organic, it can be formed using a solution in which an organic insulating substance is dissolved or its precursor solution (solvent 0.1 to 20% by weight, preferably 0.5% by weight). 2 to 10% by weight) by a spinner coating method, dip coating method, screen printing method, spray coating method, roll coating method, etc., and cure and form under predetermined curing conditions (for example, under heating). I can do it.

The thickness of the insulating orientation control layer is usually 30 to 1 μm, preferably 30 to 3000, more preferably 50 to 1 μm.
000 people is suitable.

These two glass substrates 2 are kept at an arbitrary distance by a spacer 5. For example, using silica beads or alumina beads with a predetermined diameter as spacers, the glass substrate 2
There is a method in which the material is held between two sheets and the surrounding area is sealed using a sealing material such as an epoxy adhesive. In addition, a polymer film or glass fiber may be used as a spacer.

A ferroelectric liquid crystal is sealed between these two glass substrates.

The ferroelectric liquid crystal layer in which the ferroelectric liquid crystal is sealed is generally 0.5 to 20 μm, preferably 1 to 5 μm.

In addition, this ferroelectric liquid crystal has an SmC phase (chiral smectic C phase) in a wide temperature range including room temperature (especially on the low temperature side), and when used as an element, it has a wide driving voltage margin and driving temperature margin. It is hoped that

In addition, in order to exhibit good homogeneous orientation and obtain a monodomain state especially when used as an element, the ferroelectric liquid crystal must be changed from the tomoyoshi phase to the ch phase (cholesteric phase) - S m A phase (smectic A phase) - It is desirable to have a phase transition series called SmC phase (chiral smectic C phase).

The transparent electrode 3 is connected to an external power source 7 by a lead wire.

Further, a polarizing plate 8 is bonded to the outside of the glass substrate 2.

The device shown in FIG. 1 is of a transparent type and is equipped with a light source 9.

FIG. 2 schematically depicts an example of a cell for explaining the operation of a ferroelectric liquid crystal element. 21a and 21b are In203, SnO2 or ITO (In
It is a substrate (glass plate) coated with a transparent electrode made of a thin film such as dium-Tin oxide), between which a liquid crystal molecular layer 22 is oriented perpendicularly to the glass surface.
Liquid crystal of mC* phase or SmH wood 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 perpendicular to the molecule. Substrates 21a and 21b
When a voltage higher than a certain threshold is applied between the upper electrodes, the helical structure of the liquid crystal molecules 23 is unraveled, and the dipole moment (P
Above) The alignment direction of the liquid crystal molecules 23 can be changed so that all of the liquid crystal molecules 24 are oriented in the direction of the electric field. The liquid crystal molecules 23 have an elongated shape and exhibit refractive index anisotropy in the long axis direction and the short axis direction. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the optical polarity changes depending on the voltage applied polarity. It is easily understood that this becomes a liquid crystal optical modulation element whose characteristics change.

The liquid crystal cell preferably used in the optical modulation element of the present invention can have a sufficiently thin thickness (for example, 1Oμ or less).As the liquid crystal layer becomes thinner, as shown in FIG. Even when no electric field is applied to the cell, the helical structure of the liquid crystal molecules is unraveled, and the dipole moment Pa or pb is either upward (34a) or downward (34b). As shown in the figure, an electric field Ea or Eb with a different polarity above a certain threshold value
is applied by the voltage applying means 31a and 31b, the dipole moment changes direction to upward direction 34a or downward direction 34b corresponding to the electric field vector of electric field Ea or Eb,
Accordingly, the liquid crystal molecules are aligned in either the first stable state 33a or the second stable state 33b.

As mentioned above, there are two advantages to using such ferroelectricity as an optical modulation element.

The first is that the response speed is extremely fast, and the second is that the alignment of liquid crystal molecules has bistability. To further explain the second point with reference to FIG. 3, for example, when the electric field Ea is applied, the liquid crystal molecules are oriented in a first stable state 33a, and this state remains stable even when the electric field is turned off. Furthermore, when an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to the second stable state 33b and change their orientation, but they remain in this state even after the electric field is turned off. Also, the electric field E
As long as a or Eb does not exceed a certain threshold, the respective previous orientations are maintained.

When a simple matrix display device is constructed using a device in which a ferroelectric liquid crystal material having such characteristics is sandwiched between a pair of substrates,
For example, Japanese Unexamined Patent Publication No. 59-193426, No. 59-19
No. 3427, No. 60-156046 and No. 60
The driving method disclosed in Japanese Patent No.-156047 and the like can be applied.

FIG. 4 is a waveform diagram of the driving method used in the embodiment of the present invention. Further, FIG. 5 is a plan view of a ferroelectric liquid crystal panel 51 on which matrix electrodes used in the present invention are arranged. In the panel 51 of FIG. 5, a scanning line 52 and a data line 53 are wired to cross each other, and a ferroelectric liquid crystal is arranged between the scanning line 52 and the data line 53 at the intersection. .

In FIG. 4(A), Ss is the selection scanning waveform applied to the selected scanning line, SN is the unselected scanning waveform, and Is is the selection information waveform (black) applied to the selected data line. ), ■, represents a non-selection information signal (white) applied to an unselected data line. Also, in the figure (I
s ss) and (rN-88) are the voltage waveforms applied to the pixels on the selected scanning line, the pixels to which the voltage (Is ss) is applied take a black display state, and the voltage (IN S
The pixel to which S) is applied assumes a white display state.

FIG. 4(B) is a time series waveform when the display shown in FIG. 6 is performed using the drive waveform shown in FIG. 4(A).

In the driving example shown in FIG. 4, the minimum application time Δt of the unipolar voltage applied to the pixels on the selected scanning line corresponds to the time of the write phase t2, and the time of one phase on the l line clear corresponds to 2. It is set to Δt.

Now, each parameter Vs* of the drive waveform shown in FIG.
The values of v and lΔt are determined by the switching characteristics of the liquid crystal material used. FIG. 7 shows the change in transmittance T, that is, the V-T characteristic, when the drive voltage (vs+V) is changed while keeping the bias ratio, which will be described later, constant. Here, △t=50 μs, bias ratio Vz
/ (Vx+Vs)=1/3i: Fixed. 7th
The waveform shown in FIG. 4 (IN 511) is applied to the positive side of the figure, and the waveform shown (ts ss) is applied to the negative side. Here V
, , V3 are called an actual drive threshold voltage and a crosstalk voltage, respectively. However, v2〈v, <v3) and △v=(V
3 V, ) is called the voltage margin, and is the voltage width that allows matrix drive. It can be said that v3 generally exists in FLC matrix drive. Specifically, it is the voltage value that causes switching due to vB' in the waveform of FIG. 4(A) (IN ss). Of course, it is possible to increase the value of v3 by increasing the bias ratio, but increasing the bias ratio means increasing the amplitude of the information signal, which may lead to an increase in flickering in terms of image quality. This is undesirable because it causes a decrease in contrast.In our study, a bias ratio of about 1/3 to 1/4 is practical.By the way, if the bias ratio is fixed, the voltage margin △V
It depends strongly on the switching characteristics of the liquid crystal material, and it goes without saying that a liquid crystal material with a large ΔV is very advantageous for matrix driving.

At a certain temperature like this, it is possible to write two states, "black" and "white", into a selected pixel depending on the two directions of the information signal, and non-selected pixels can write the "black" state into the selected pixel.
Or the upper and lower limits of the applied voltage that can maintain the "white" state and their widths (drive voltage margin △V)
is different and unique among liquid crystal materials. The drive margin also decreases due to changes in the environmental temperature (because
In the case of an actual display device, it is necessary to set the drive voltage to the optimum value for the liquid crystal material and environmental temperature.

However, in practice, when expanding the display area of such a matrix display device, the difference in the environment in which the liquid crystal exists in each pixel (specifically, the difference in temperature and cell gap between electrodes) naturally increases ( Therefore, with a liquid crystal with a small driving voltage margin, it is not possible to obtain a good image over the entire display area.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

Example 1 The following exemplified compounds were mixed in the following parts by weight to prepare liquid crystal composition 1-
I created A.

C, l(,0CH2CH,0@-C←→[phase]-C page,
H2゜ Exemplary compound l-5 for this liquid crystal composition 1-A
2-6 were mixed in the following parts by weight to obtain liquid crystal composition 1-B.

Exemplary compound no.

Structural Formula Next, optical responses were observed using cells prepared using these liquid crystal compositions according to the following procedure.

Two glass plates with a thickness of 1 mm and 1 mm were prepared, an ITO film was formed on each glass plate to create a voltage application electrode, and SiO2 was further vapor-deposited thereon to form an insulating layer.

On this substrate, a polyimide resin precursor [Toshi ■ 5P-51
0] 1.0% dimethylacetamide solution at 30 revolutions
Coating was performed for 15 seconds using a 0Or, p, m spinner. After the film was formed, a heating condensation firing process was performed at 300° C. for 60 minutes. The thickness of the coating film at this time was about 120 people.

This fired coating was rubbed with acetate flocked cloth, then washed with isopropyl alcohol solution, and silica beads with an average particle size of 1.5 μm were sprinkled on one glass plate. so that they are parallel to each other, and apply adhesive sealant [Rixon Bond (
The glass plates were glued together using a Chisso (Japanese Society) holder and dried by heating at 100° C. for 60 minutes to create a cell. The cell thickness of this cell was measured using a Bereck phase plate and was approximately 1.
It was 5 μm.

A ferroelectric liquid crystal element was prepared by injecting the liquid crystal composition 1-B described above in an isotropic liquid state into this cell and slowly cooling it from the isokyoshi phase to 25°C at a rate of 20°C/h.

Using this ferroelectric liquid crystal element, drive voltage margin △V(
V3 Vr) was measured. The results are shown below (in addition, △
Seed setting where t is v2#15v).

10℃ 25℃40℃ Drive voltage merge: / 12. OV12
．． 5V 9.5V (Measurement setting △t) (
735μ5ec) (225μ5ec) (901
t 5ec) Furthermore, if the voltage is set to the median value of the drive voltage margin at 25°C and the measurement temperature is changed, the temperature difference that can be driven (hereinafter referred to as the drive temperature margin) is
It was 4°C.

Also, the contrast during this drive at 25°C is lO
Met.

Comparative Example 1 Liquid crystal composition 1 in which only exemplary compound No. 2-6 was mixed with 1-A without mixing exemplary compound No. 1-5 of liquid crystal composition 1-B used in Example 1. Liquid crystal composition 1-D in which only exemplary compound No. 1-5 was mixed with 1-A without mixing -C and exemplary compound No. 2-6
It was created.

Instead of using liquid crystal composition 1-B, liquid crystal composition 1-A,
All (
A ferroelectric liquid crystal element was produced in the same manner as in Example 1, and the driving voltage margin ΔV was measured. The results are shown below.

Driving voltage margin (W when measured > 10℃ 2 sets 40℃ 1-A 9.OV 9.5V 8
．． 5V (1050μ5ec) (280μ5ec)
(78μ5ec) 1-CIo, 5V 10
．． 5V 9.0V (895p 5ec)
(255μ5ec) (76μ5ec) 1-D
lo, 5V 10.5V 9.0V
(900μ5ec) (260μ5ec) (
77μ5ec) Furthermore, the driving temperature margin at 25℃ is 2.2℃ above for 1-A, 2.6℃ above for 1-C, and 2.6℃ above for 1-D.
The temperature was 2.5°C.

As is clear from Example 1 and Comparative Example 1, the ferroelectric liquid crystal element containing the liquid crystal composition 1-B according to the present invention has a wider driving margin and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 2 The following exemplified compounds were mixed in the following parts by weight to prepare liquid crystal composition 2-
I created A.

c, H, OCH! co, o@coo@@cooc,
H.

C1゜)12. o@-coo@oc, H.

Exemplary compound 1-5゜2- for this liquid crystal composition 2-A
6 in the following parts by weight, respectively, to prepare liquid crystal composition 2-B.
I got it.

Exemplary compound no.

A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, except that structural formula liquid crystal composition 1-B was replaced with this liquid crystal composition 2-B.
The driving voltage margin ΔV was measured in the same manner as in Example 1, and the switching state and the like were observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

10℃ 25℃ 40℃ Drive voltage margin! 2.5V 13. OV 10.
OV (Measurement setting △t) (700μ5ec)
(210μ5ec) (90p 5ec) Furthermore, 2
The driving temperature margin at 5°C was 3° to 6°C. Further, the contrast during this driving at this temperature was 9.

Comparative Example 2 Liquid crystal composition 2 in which only exemplary compound No. 2-6 was mixed with 2-A without mixing exemplary compound No. 1-5 of liquid crystal composition 2-B mixed in Example 2. Liquid crystal composition 2-D in which only exemplary compound No. 1-5 was mixed with 2-A without mixing -C and exemplary compound No. 2-6
It was created.

Instead of using liquid crystal composition 1-B, liquid crystal composition 2-A,
A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that 2-C and 2-D were injected into the cell, and the driving voltage margin ΔV was measured. The results are shown below.

Drive voltage margin (setting △t during measurement) 10°C 25°C40°C 2-A Io, 5V 10.5V
8.5V (1200μ5ec) (330μ
5ec) (98μ5ec)2-C11,OV
11.5V 9.0V (1060
μ5ec) (320μ5ec) (96μ
5ec) 2-D Io, 5V 10.5
V 8.5V (1020μ5ec) (
300μ5ec) (95p 5ec) Furthermore,
Driving temperature margin at 25°C is ±2.5 at 2-A
°C, 2.8°C at 2-C, and 2.5°C above at 2-D.

As is clear from Example 2 and Comparative Example 2, the ferroelectric liquid crystal element containing the liquid crystal compound 2-B according to the present invention has a wider drive margin, and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 3 Liquid crystal composition 2-A used in Example 2 was mixed with the following exemplified compounds in the weight parts shown below to obtain liquid crystal composition 3-B.

Exemplary Compound No. Structural Formula A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that this compound was used, and the drive margin was measured in the same manner as in Example 1 and the switching state etc. were observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

10℃ 25℃ 40℃ Drive voltage margin 12. OV 13. OV 10.
5V (setting Δt during measurement) (720μ5ec)
(210μ5ec) (92μ5ec) further 25℃
The driving temperature margin was ±3.4°C. Further, the contrast during this driving at this temperature was 8.

Comparative Example 3 Liquid crystal composition 3 in which only exemplary compound No. 1-20 was mixed with 2-A without mixing exemplary compound No. 2-14 of liquid crystal composition 3-B used in Example 3. Liquid crystal composition 3-D in which only exemplary compound No. 2-14 was mixed with 2-A without mixing -C and exemplary compound No. 1-20
It was created.

Instead of using liquid crystal composition 1-B, liquid crystal composition 2-A,
A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that 3-C and 3-D were injected into the cell, and the driving voltage margin ΔV was measured. The results are shown below.

Drive voltage margin (measurement setting △t) 10℃ 25℃ 40℃2-A I
o, 5V lo, 5V 8.5V (
1200μ5ec) (330μ5ec) (
98μ5ec) 3-C11,5V lo, 5
V 8.5V (1050μ5ec) (3
30μ5ec) (98μ5ec)3-D 1
2. OV 11. OV 9.0V (
1000μ5ec) (310p 5ec)
(95 μ5 ec) Furthermore, the driving temperature margin at 25 °C is ±2.5 °C for 2-A, ±2.5 °C for 3-C, and ±2.5 °C for 3-C.
It was ±2.7°C at D.

As is clear from Example 3 and Comparative Example 3, the ferroelectric liquid crystal element containing the liquid crystal composition 3-B according to the present invention has a wider driving margin and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 4 Liquid crystal composition 2-A used in Example 2 was mixed with the following exemplified compounds in the weight parts shown below to obtain liquid crystal composition 4-B.

Exemplary Compound No. Structural Formula A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that this compound was used, and the drive margin was measured in the same manner as in Example 1 and the switching state etc. were observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

10°0 25°C 40°C Drive voltage merge: / 12.5V 13. O.V.
9.5V (setting at measurement △t) (760μ
5ec) (210p 5ec) (72μ5ec
) Furthermore, the driving temperature margin at 25℃ is ±3.6
It was ℃. Further, the contrast during this driving at this temperature was 11.

Comparative Example 4 Liquid crystal composition 4 of liquid crystal composition 4-H used in Example 4, in which only exemplary compound No. 1-10 was mixed with 2-A without mixing exemplary compound No. 2-18. Liquid crystal composition 4-D was prepared by mixing only exemplary compound No. 2-18 with 2-A without mixing -C and exemplary compound No. 1-10.

Instead of using liquid crystal composition 1-B, liquid crystal composition 2-A,
A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, except that 4-C and 4-D were injected into the cell, and the driving voltage margin ΔV was measured.The results are shown below. .

Drive voltage margin (setting △t during measurement) 10°C 25°C 40°C2-A
9. OV 9.5V 8.5V (10
00u 5ec) (265u 5ec) (7
5tt 5ec) 4-CIo, 5V lo, O
V 8.2V (880μ5ec) (24
0μ5ec) (75μ5ec) 4-D I
o, 5V 10. OV 8.5V (9
10u 5ee) (245μ5ec) (7
Furthermore, the driving temperature margin at 25°C was ±2.3°C for 2-A, ±2.7°C for 4-C, and ±2.5°C for 4-D.

As is clear from Example 4 and Comparative Example 4, the ferroelectric liquid crystal element containing the liquid crystal composition 4-B according to the present invention has a wider driving margin and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 5 The following exemplified compounds are mixed in the following parts by weight to form a liquid crystal. A sexual composition 5-A was prepared.

c. ++□, o@-coo@-oc, n, 7 Exemplary Compound No.

Structural formula % Formula % Exemplary compound 1-20°2 for this liquid crystal composition 5-A
-14 were mixed in the following parts by weight to obtain liquid crystal composite acid 5B.

Exemplary compound no.

Structural formula % Formula % A ferroelectric liquid crystal element was prepared in the same manner as in Example 1 except that liquid crystal composition 1-B was replaced with this liquid crystal composition 5-B.
The driving voltage margin ΔV was measured in the same manner as in Example 1, and the switching state and the like were observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

10℃ 25℃ 40℃ Drive voltage margin 10.7V 11. O.V.
7.2V (setting at measurement △t) (300μ5
ec) (90p 5ec) (35μ5ec)
Furthermore, the driving temperature margin at 25°C is ±2.9
It was ℃. Further, the contrast during this driving at this temperature was 9.

Comparative Example 5 Liquid crystal composition 5 in which only exemplary compound No. 1-20 was mixed with 5-A without mixing exemplary compound No. 2-14 of liquid crystal composition 5-B mixed in Example 5. Liquid crystal composition 5 in which only exemplary compound No. 2-14 was mixed with 5-A without mixing -C and exemplary compound No. 1-20.
-D was created.

Instead of using liquid crystal composition 1-B, liquid crystal composition 5-A,
A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that 5-C and 5-D were injected into the cell, and the driving voltage margin ΔV was measured. The results are shown below.

Drive voltage margin (measurement setting △t) 10℃ 25℃ 40℃5-A
8. OV 8. OV 6.0V (
400u 5ec) (110μ5ec)
(40μ5ec)5-C8, OV 8.5
V 6.2V (360μ5ec) (
100μ5ec) (35μ5ec)5-D
8. OV 8,7V 6.0V
(330p 5ee) (100μ5ec)
(35μ5ec) Furthermore, the driving temperature margin at 25°C is ±1.9°C at 5-A, and 2°1 above at 5-C.
'C, 5-D was ±2.2°C.

As is clear from Example 5 and Comparative Example 5, the ferroelectric liquid crystal element containing the liquid crystal composition 5-B according to the present invention has a wider driving margin and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 6 Liquid crystal composition 5-A used in Example 5 was mixed with the following exemplified compounds in the weight parts shown below to obtain liquid crystal composition 6-B.

Exemplary Compound No. Structural Formula A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that this compound was used, and the drive margin was measured in the same manner as in Example 1 and the switching state etc. were observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

10°C 25°C 40°C Drive voltage margin 10.2V 10.6V 7.
OV (Measurement setting △t) (310μ5ec)
(95p 5ec) (35μ5ec) 25 more
The driving temperature margin in °C was ±2.8 °C.

Also, the contrast during this drive at this temperature is 1
It was 0.

Comparative Example 6 Liquid crystal composition 6 in which only exemplary compound No. 1-10 was mixed with 5-A without mixing exemplary compound No. 2-18 of liquid crystal composition 6-B used in Example 6. -C
Liquid crystal composition 6-D was prepared by mixing only exemplified compound No. 2-18 with 5-A without mixing exemplified compound No. 1-10.

Instead of using liquid crystal composition 1-B, liquid crystal composition 5-A,
A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that 6-C and 6-D were injected into the cell, and the driving voltage margin ΔV was measured. The results are shown below.

Drive voltage margin (setting △t during measurement) 10°C 25°C 40°C2-A
8. OV 8. OV 6.0V (40
0μ5ec) (110,czsec) (4
0μ5ec) 6-C8, OV 8.5V
6. IV (360μ5ec) (100μ5e
c) (40μ5ec)6-D 8. O.V.
8.5V 6.0V (350μ5ec
) (too μ5ec) (40p 5ec
) Furthermore, the driving temperature margin at 25°C is 5-A
±1.9℃ at 6-C, ±2.1℃ at 6-D, ±2 at 6-D,
It was 1'C.

As is clear from Example 6 and Comparative Example 6, the ferroelectric liquid crystal element containing the liquid crystal composition 6-B according to the present invention has a wider driving margin and is less susceptible to changes in environmental temperature and variations in cell gap. It has an excellent ability to maintain good image quality.

Example 7 Liquid crystal compositions 5-B used in Example 5 and Comparative Example 5.

All of 5-C, 5-D, and 5-A were prepared in the same manner as in Example 1, except that the alignment control layer was made only with polyimide resin without using Sio2. Example I
The driving voltage margin was measured using the same method as above. The results are shown below.

Drive voltage margin (setting △t during measurement) 10℃ 25℃ 40℃ 5-B 10.9V 11.3V
7.7V (290μ5ec) (90μ5e
c) (40μ5ec)5-C8,OV
8.7V 6.4V (340μ5ec)
(100μ5ec) (40μ5ec)5-D
8.2V 8.7V 6.2V
(320μ5ec) (100μ5ec) (
40μ5ec) 5-A 8.2V 8
．． 3V 6.3V (370B 5ec)
(100μ5ec) (40p 5ec) 2 more
The driving temperature margin at 5°C is 5-B ±3.
[: 5-C 2°2°C 3-D ±2.3°C 5-A ±2.0°C.

As is clear from Example 7, even when the element configuration is changed, the element containing the ferroelectric liquid crystal composition 5-B according to the present invention has the same performance as in Example 5 compared to the element containing other liquid crystal compositions. The drive margin is wide, and the ability to maintain good images despite changes in environmental temperature and variations in cell gap is excellent.

Examples 8 to 13 In place of the exemplified compounds and liquid crystal compositions used in Example 1.2.5, the exemplified compounds and liquid crystal compositions shown in Table 1 were used in respective parts by weight to produce 8-B to 13-B. A liquid crystalline composition was obtained. A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except for using these, and the drive margin at 25° C. was measured in the same manner as in Example 1, and the switching state and the like were observed.

Uniform alignment within each liquid crystal element created was good;
A monodomain state was obtained. The measurement results are shown in Table 1.

As is clear from Examples 8 to 13, the ferroelectric liquid crystal element containing the liquid crystal composition 8-B-13-B according to the present invention has a wide driving margin and is resistant to changes in environmental temperature and variations in cell gap. On the other hand, it has an excellent ability to maintain good images.

〔Effect of the invention〕

The device containing the ferroelectric liquid crystal composition of the present invention has good switching characteristics, a large drive voltage margin, and a drive that allows all pixels to be satisfactorily driven in matrix even if there is a certain degree of temperature variation over the display area of the device. A liquid crystal element with a wide temperature margin can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of an example of a liquid crystal display element using ferroelectric liquid crystal, and Figures 2 and 3 schematically represent an example of an element cell to explain the operation of a ferroelectric liquid crystal element. A perspective view, FIG. 4 is a waveform diagram of the driving method used in the examples, FIG. 5 is a plan view of a ferroelectric liquid crystal panel with matrix electrodes arranged, and FIG. 6 is shown in FIG. 4 (B). Figure 7 is a schematic diagram of the display pattern when actual driving is performed using time-series driving waveforms.
In Figure 1, which shows the change in transmittance when the driving voltage is changed, that is, the V-T characteristic diagram, ferroelectric liquid crystal layer 2...
......Glass substrate 3...
・・・・・・・・・・・・Transparent electrode 4・・・・・・・
...Insulating orientation control layer 5 ......
・・・・・・Spacer 6・・・・・・・・・・・・・・・
・・・・・・Lead wire 7・・・・・・・・・・・・・・・
・・・・・・Power supply 8・・・・・・・・・・・・・・・・・・
・・Polarizing plate 9・・・・・・・・・・・・・・・・・・・
・Light source 1o・・・・・・・・・・・・・・・Incoming light ■・・・・・・・・・・・・・・・・・・Transmitted light In Fig. 2, 21a ・・・・・・・・・・・・・・・ Board 2
1b ・・・・・・・・・・・・・・・ ・Substrate 3rd
In the figure, 1a 1b 3a 3b 4a 4b a b Ferroelectric liquid crystal layer Liquid crystal molecule Dipole moment (P) Voltage application means Voltage application means First stable state Second stable state Upward dipole moment Downward dipole Moment Upward electric field Downward electric field

Claims (2)

[Claims] (1) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 is a linear or branched alkyl group that may have a substituent of C_1 to C_1_8. , R_2
is a linear or branched alkyl group that may have substituents C_1 to C_1_4, X_1 and X_2 are single bonds,
-O-, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas,
There are chemical formulas, tables, etc. ▼, m is 0 to 7, n is 0 or 1), and at least one compound represented by the following general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ( However, R_3 and R_4 are linear or branched alkyl groups that may have substituents of C_1 to C_1_8, X_3 and X_4 are single bonds, -O-, ▲ mathematical formula, chemical formula,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc. ▼, Y_1 is -CH
A ferroelectric chiral smectic liquid crystal composition containing at least one compound represented by _2O- or -OCH_2-, p and q are 1 or 2). (2) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 is a linear or branched alkyl group that may have a substituent of C_1 to C_1_8. , R_2
is a linear or branched alkyl group that may have substituents C_1 to C_1_4, X_1 and X_2 are single bonds,
-O-, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ Mathematical formulas,
There are chemical formulas, tables, etc. ▼, m is 0 to 7, n is 0 or 1), and at least one of the following general formulas (II) ▲There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) (However, , R_3, R_4 are linear or branched alkyl groups that may have substituents of C_1 to C_1_8, X_3, X_4 are single bonds, -O-, ▲ mathematical formula, chemical formula,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲There are mathematical formulas, chemical formulas, tables, etc. ▼, Y_1 is -CH
A ferroelectric chiral smectic liquid crystal composition containing at least one compound represented by _2O- or -OCH_2-, p and q are 1 or 2) is arranged between a pair of electrode substrates. liquid crystal element.