JPH0224389A - Liquid crystal composition and liquid crystal element containing the same composition - Google Patents

Abstract

PURPOSE:To obtain a liq. crystal element exhibiting a high response speed and having a decreased dependence of the response speed on the temp. by employing a ferromagnetic liq. crystal compsn. contg. two particular compds. CONSTITUTION:A liq. crystal element is formed by employing a ferromagnetic chiral smectic liq. crystal compsn. contg. the following components A and B. Component A is at least one compd. of formula I, wherein each of R1 and R2 is a straight-chain or branched alkyl group which may have a 1-18C substituent; each of X1 and X2 is a single bond, -O-, a group of the formula II, etc.; Y1 is -CH2O- or -OCH2-; and each of m and n is 1 or 2. Component B is at least one compd. of formula III, wherein R3 is a straight-chain or branched alkyl group which may have a 1-18C substituent; X3 is any one of a single bond, -O- and a group of formula II; Z is a single bond or a group of formula II; formula IV is formula V or formula VI; and p is 1-12.

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 include, for example, M, Schadt and W, He.
“Applied Physics L” by 1frich
etters Vo, 18, No. 4 (1971,
2, 15), P, 127-128 “Voltage-
3pendent 0ptical Activi
Ty of a Twisted Nematic
TN shown in Liquid Crystabi
(twisted nematic) 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 oriented in a specific direction due to the dielectric anisotropy of liquid crystal molecules due to an applied electric field. It is said that the limit of the optical response speed of these elements is milliseconds, which is too slow for large-scale applications.On the other hand, when considering the cost and productivity, it is difficult to apply them to large flat displays. The most promising method is driving by the matrix method. In the simple matrix method, an electrode configuration in which a scanning electrode group and a signal electrode group are arranged in a matrix is adopted.
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 one frame. For this reason, the effective voltage difference between selected points and non-selected points when repeated scanning is
The more the number of scanning lines increases, the smaller the size becomes, 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 while 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 Agerwall (Japanese Unexamined Patent Application Publication No. 1983-1999)
107216, US Pat. No. 4,367,924, etc.). As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral smectic 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. For this reason, extensive research has been conducted on liquid crystal materials with ferroelectric properties, and the ferroelectric liquid crystal materials developed to date are suitable for use in liquid crystal devices, including their low-temperature operating characteristics and high-speed response. It is hard to say that it has sufficient characteristics.

There exists a relationship between the response time τ, the magnitude of spontaneous polarization Ps, and the viscosity η. Therefore, in order to increase the response speed, (a) increase the magnitude of the spontaneous polarization Ps (b) increase the viscosity η
There is a method of reducing the voltage and increasing the applied voltage E.However, since the applied voltage is driven by an IC or the like, there is an upper limit to the applied voltage, and it is desirable that the applied voltage be as low as possible.

Therefore, in reality, it is necessary to reduce the viscosity η or increase the value of the spontaneous polarization magnitude Ps.

- For boat fishing In ferroelectric chiral smectic liquid crystal compounds with large spontaneous polarization, the internal electric field of the cell caused by the spontaneous polarization is also large, and there tends to be more restrictions on device configurations that can take a bistable state. Furthermore, even if the spontaneous polarization is unnecessarily increased, the viscosity tends to increase as well, and as a result, the response speed may not become very fast (□).

Furthermore, when the actual operating temperature range for a display is, for example, 5 to 40 degrees Celsius, the response speed generally changes by about 20 times, which is currently beyond the limits of adjustment by drive voltage and frequency. .

As mentioned above, in order to put ferroelectric liquid crystal devices into practical use, a ferroelectric chiral smectic liquid crystal composition that has low viscosity, high-speed response, and small temperature dependence of response speed is required. .

[Problem that the invention seeks to solve]

An object of the present invention is to provide a chiral smectic liquid crystal composition that has a high response speed and reduced temperature dependence of the response speed, and a liquid crystal element using the liquid crystal composition, so that a ferroelectric liquid crystal element can be put to practical use. It is about providing.

[Means for solving the problem] The present invention is based on the following general formula (1) (wherein R1 and R2 are linear or branched alkyl groups which may have a substituent of CI'=CIII, Yl is -CH2〇- or -〇〇H2-1m, n is l or 2)
At least one compound represented by the following general formula (I
I) (However, R3 is a linear or branched alkyl group that may have a substituent of c + ""' 01B,
X3 shows. The present invention provides a ferroelectric chiral smectic liquid crystal composition characterized by containing a small amount (at least one kind) of the compound shown in be.

Among the compounds represented by the above general formula (I), preferred examples include compounds represented by the following formulas (I-a) to (If).

R, -X, -◎-CH20-◎-X2-R2(I-a
)R, -X, -◎-0CH2-◎-X2 R2(I
b) R, -X, -◎-CH20-◎-◎-X2R2
(1-c) R, -X, -◎-0CH20-◎-◎-X2
-R2(I d)R, -X, -◎-◎-CH2
0-◎-X2 R2 (I e) R, -X, -pe)←
0-OCH2-◎-X2-R2(t-r) Furthermore, preferable examples of Xl and X2 in the above formulas (I-a) to (I-f) include the following (1-i) to (1- viii)
can be mentioned.

XI is a single bond, x2 is a single bond X, is a single bond, x2 is -〇-X, is a single bond, x
2 is -COX, is a single bond, X2 is -O
CX, is -0-1X2 is single bond x1 is 10-
1x2 is X, is -0-1X2 is -CO ) (1-vii) (Iviii) Furthermore, R in the above formulas (I-a) to (If)
,, Preferred examples of R2 include (1-ix) to (1
-xiii) (p is 0 to 7, R5 is a linear or branched alkyl group) CH3 R2 is RmoCH21CHRs.

* (p, q are θ~7, R,, R6 are linear or branched alkyl groups) (1-xi) R1 is an n-alkyl group.

door R2 is CH2-CH-CrH2r+1-n * (1-xii) R is an n-alkyl group.

Day 0 3 R2 is (-CH2-containing CSmoCH2to-R7ne (S is 0 to 7, t is O or 1.R7 is a linear or branched alkyl group) In addition, the above general formula ( Among the compounds represented by formula (II), preferred examples include the following formula (II-a):
~, (II-b) Compounds represented by the formula are mentioned.

(IT-a) (II-b) (r is 1 to 12) The above general formula The specific structure of the compound shown in An example of the construction formula is shown below.

n C7HIS# 0CH2+OC6H,7nn C@
H17+ CH20+OCa HI3Ca Hl? +
CH2o ■) (Tear 0-C8H, 7n Cs Hrym
CH2o+o-c a H13n C? Hlsm
CM 2 o (Oki oc 6 H, 1n-C @ H17
-0-◎-OCH2+OCa H11(I (] n-C, H,, +cH2o(■@-co-c s H1
7-n-eup C? H+s o-@)CH204■-05HC6H1
3-n(+-67) The compound represented by the general formula (I) is disclosed in JP-A-60-14
9547 (1985), JP-A-61-63633
(1986). Typical synthesis examples are shown below.

Synthesis Example 1 (Synthesis of Compound No. 1-54) 1.0 g of the following alcohol derivative (4.81 m
mol) was added thereto, 3 ml of thionyl chloride was added under cooling, and the temperature was raised to room temperature while stirring.Furthermore, a cooling tube was attached, and heating and reflux was performed 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 15 ml of toluene.

Next, 0.33 g of 60% oily sodium hydride was placed in a 200 ml three-necked flask, washed several times with dry n-hexane, and 1.52 g of the following phenol derivative (4.81 m
mol) of THF solution was added dropwise at room temperature, and further 20 ml of DMSO was 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 mixture was poured into about 200 ml of ice water, the organic layer was separated, and the aqueous layer was extracted twice with 50 ml of benzene. After washing with the previously separated organic layer twice with 5% aqueous hydrochloric acid, the ions were extracted. 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%) CHN Calculated value 78.33 8.57 0.00
Measured value 78.96 8.69 0.02
Phase Rearrangement Synthesis Example 2 (Synthesis of Compound No. 1-68) 1.25 g of the following alcohol derivative was added to a 30 ml eggplant flask.
0-◎(Tears) Add CH20H (4,01 mmol) and add thionyl chloride 3 under cooling.
ml was added, the temperature was raised to room temperature while stirring, a cooling tube was attached, and heating and reflux was performed 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 15 ml of toluene.

Next, 0.31 g of 60% oily sodium hydride was placed in a 200 ml three-necked flask, washed several times with dry n-hexane, and then 0.79 g of the following phenol derivative (4, Olm
mol) of THF solution was added dropwise at room temperature, and further 20 ml of DMSO was 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 mixture was poured into approximately 200 ml of ice water, the organic layer was separated, and the aqueous layer was extracted twice with 50 ml of benzene, and the organic layer was washed twice with 5% aqueous hydrochloric acid solution together with the previously separated organic layer. The organic layer was washed once with ion-exchanged water and once with 5% NaOH aqueous solution, and then 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, 3/10.

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.

yield The general formula (n) The specific compound shown in was 26.0%.

An example of a structural formula is shown below.

CHN analysis value (wt%) Calculated value 78.33 8.63 0, Oo Theoretical value 78.62 8.86 0.02 Phase transition S 2 + is unidentified IR spectrum 2975° 2925° 2850° 1610° 1510° 1470゜1380゜1295゜1280゜1240゜1220゜1130゜1020, 1000. 810 cm-'+8) The compound represented by the general formula (IT) can be obtained by synthetic routes A, B, and C as shown below.

Synthetic route A Synthetic route B Synthetic route C (X3:0) (R3, X3.P are as described above) Representative synthetic examples of the compound represented by general formula (1) are shown below.

Synthesis Example 1 (Synthesis of Compound No. 2-17) p-2-fluorooctyloxyphenol 1. OOg (4, 16m
M) was dissolved in 10 ml of pyridine and 5 ml of toluene, and 1,30 g of trans-4-n-pentylcyclohexanecarboxylic acid chloride (6,00 m M
) dissolved in 5 ml of toluene was added dropwise at 5° C. or lower over 20 to 40 minutes. After the dropwise addition, the mixture was stirred at room temperature overnight to obtain a white precipitate.

After the reaction was completed, the reaction product was extracted with benzene, and the benzene layer was further washed with distilled water, and then the benzene layer was dried over magnesium sulfate, and the benzene was distilled off. It was further purified using silica gel column chromatography and recrystallized from ethanol/methanol.
n-pentylcyclohexanecarboxylic acid-p-2-fluorooctyloxyphenyl ester 1.20g (2
, 85mM) was obtained. (Yield 68.6%) NMR data (ppm) 0.83-2.83ppm (34H, m)4, OO
~4.50ppm (2H,q)7,llppm
(4H,5) IR data (cm-') 3456, 29.2B, 2852. 1742.
1508°1470, 1248. 1200.
1166, 1132° 854° Phase transition temperature (°C) (Here, s3.s4.s5.s6 indicates a phase with a higher degree of order than SmC*.) Synthesis Example 2 (Synthesis of Compound No. 2-29) ) In a container that is sufficiently purged with nitrogen, add (-)-2-fluoroheptatorol 0.
, 40 g (3.0 m m o I) and 1.00 g (13 mmol) of dry pyridine were added and heated under water cooling for 30 g.
Dry for a minute. To the solution was added 0.69 g (3.6 mm o + ) of p-)luenesulfonic acid chloride, and stirring was continued for 5 hours. After the reaction is complete, lNH
After extracting twice with 10 ml of methylene chloride, the extract was washed once with 10 ml of distilled water. After appropriately adding anhydrous sodium sulfate to the obtained methylene chloride solution and drying, the solvent was distilled off.
9 g (2.0 mmo+) were obtained.

Yield is 66%. The specific rotation and IR data of the product are as follows.

Specific optical rotation [α] Ao’+2.59° (cm1.CHCl　3　).

Specific optical rotation [α + 9.58° (c=IS　0MCl　　　,,).

IR (cm-'): 2900, 2850, 1600, 1450
．． 1350, 1170, 1090, 980
．． 810, 660, 550° 0.43 g (1.5 mmol) of (+)-2-fluoroheptyl p-)luenesulfonic acid ester obtained as above and 5-octyl-2-(4-hydro-xyphenyl ) 0.2 ml of 1-butanol was added to 0.28 g (1.0 mmol) of pyrimidine and stirred well. Into the solution in advance! -Butanol1. Om this sodium hydroxide 0
An alkaline solution prepared by dissolving . After the reaction was completed, 10 ml of distilled water was added, and extraction was performed once each with 10 ml and 5 ml of benzene, and the extract was dried by appropriately adding anhydrous sodium sulfate. After drying, the solvent was distilled off and the desired product (+) was collected using a silica gel column (chloroform).
-5-octyl-2-[4(2-fluorohebutyloxy)phenyl]pyrimidine 0.17 g (0.43 mm
ol) was obtained.

The yield was 43%, and the specific rotation and IR were as follows:
The data was obtained.

Specific optical rotation [α]; 1.5J + 0.44° (C-1,
CHCl3).

Specific optical rotation [α] +4.19° (cml, CHCl 3).

IR (cm-'): 2900, 2850, 1600, 1580°1420
, 1250, 1260, 800°720, 650
, 5500 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 one or more other liquid crystal compounds. It can be obtained by mixing 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.

C5HITO+COS + 0CH2CHC2H5ne υ υ 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 other liquid crystalline compounds mentioned above, or containing them Ferroelectric liquid crystal composition (hereinafter abbreviated as ferroelectric liquid crystal material)
The orientation ratio is per 100 parts by weight of the ferroelectric liquid crystal material,
It is preferable that each of the liquid crystalline compounds represented by the general formula (1) and the general formula (II) of the present invention be contained in an amount of 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 (1) of the present invention per 100 parts by weight
It is preferable that the mixture of two or more of one or both of the liquid crystalline compound represented by the general formula (II) be 1 to 500 parts by weight, more preferably 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 In2O3゜5n0
2 or ITO (In4ium-Tin Oxid
A transparent electrode made of a thin film such as e) 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. , an organic insulating material such as melamine resin, Yulia resin, acrylic resin or photoresist resin as an orientation control layer.
The insulating alignment control layer may be formed of two layers, or may be a single layer of an insulating alignment control layer of an inorganic substance or an insulating alignment control layer of an organic substance. 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). 2-10% by weight)
It can be applied by a spinner coating method, dip coating method, screen printing method, spray coating method, roll coating method, etc., and cured and formed under predetermined curing conditions (for example, under heating).

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 a 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 low viscosity and high-speed response. It is desirable that the temperature dependence of the response speed be small.

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)-3mA phase (smectic A phase)-SmC* Phase (chiral smectic C phase)
It is desirable to have the following phase transition series.

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 In2O3, 5n02 or ITO (Indiu
A substrate (glass plate) coated with a transparent electrode made of a thin film such as m-Tin oxide), between which a liquid crystal molecular layer 22 is oriented perpendicular to the glass surface.
A liquid crystal of phase or SmH” phase is enclosed.The thick line 23 represents the liquid crystal molecule, and the liquid crystal molecule 2
3 is the dipole moment (P±
)24. When a voltage equal to or higher than a certain threshold is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is unraveled, and the liquid crystal molecules 23 are aligned in the direction such that the dipole moment (P) 24 is all directed in the direction of the electric field. can be changed. 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, it is easily understood that, for example, if crossed Nicol polarizers are placed above and below a glass surface, a liquid crystal optical modulation element whose optical characteristics change depending on the polarity of applied voltage can be obtained.

The liquid crystal cell preferably used in the optical modulation element of the present invention can have a sufficiently thin thickness (for example, 10 μm or less). As the liquid crystal layer becomes thinner, the helical structure of the liquid crystal molecules unravels even when no electric field is applied, as shown in Figure 3, and the dipole moment Pa or pb is directed upward (34a) or downward (34b). ). In such a cell, an electric field Ea or Eb of different polarity above a certain threshold value is applied as shown in FIG.
is applied by the voltage applying means 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, and accordingly, the liquid crystal molecules are in the first stable state 33a or Orientation to one of the second stable states 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.

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 A liquid crystal composition 1-A was prepared by mixing the following parts by weight.

01 (5 Structural Formula Weight Part Hardware No.

Exemplary compound 1-1.2- for this liquid crystal composition 1-A
3 were mixed in the following weight parts, respectively, to prepare liquid crystal composition 1-B.
I got it.

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

Prepare two 1.1 mm thick glass plates, form an ITO film on each glass plate, create a voltage application electrode,
Furthermore, SiO2 was deposited on top of this 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 (
Glass plates were glued together using a Chisso (scoop) 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, the optical response under crossed Nicols (transmitted light amount change 0 to 90%) is detected by applying a voltage of peak-to-peak voltage V pp = 25 V, and the response speed ( (hereinafter referred to as optical response speed) was measured. The results are shown below.

lOoC25°0 40°C Response speed 960 μsec 265 μsec
c 8s μsec Further, the contrast during this driving at 25° C. was 12, and a clear switching operation was observed.

Comparative Example 1 Liquid crystal composition 1 in which only exemplary compound No. 2-3 was mixed with 1-A without mixing exemplary compound No. 1-1 of liquid crystal composition 1-B mixed in Example 1. A liquid crystal composition L-2 was prepared by mixing only exemplary compound No. 1-1 with 1-A without mixing -C with exemplary compound No. 2-3.

Instead of using liquid crystal composition 1-B, liquid crystal composition 1-A,
Except for injecting 1-C and 1-D into the cell, all <
A ferroelectric liquid crystal device was produced in the same manner as in Example 1, and its optical response speed was measured. The results are shown below.

Response speed 10℃ 25℃ 40℃1-A
l600 μsec 430 pse
c 120 p 5ee1-C1150p se
c 290 μsec 90 μsec1-D
1380 μsec 380 psec
c 110 p see 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 better operating characteristics at low temperatures,
Example 2 The following exemplified compounds were mixed in the following parts by weight with respect to the liquid crystal composition 1-A mixed in Example 1. A liquid crystal composition 2-B was obtained.

-A A ferroelectric liquid crystal element was produced in the same manner as in Example 1 except that this was used, and the optical response speed 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.

Response speed 10℃ 25℃ 40℃940p
sec 260 p sec 85 p se
c Also, the contrast during this drive at 25°C is 1
3, a clear switching action was observed, and the bistability was also good when the voltage application was stopped.

Comparative Example 2 Among the liquid crystal compositions 2-H mixed in Example 2, 1-A was prepared without mixing exemplified compounds No. 1-5, 1-24, and 1-37.
Exemplary compound No. 2-C and exemplified compound No. 2-26. Exemplified compound No. 2-C and exemplified compound No. 1-A without mixing 2-54. ,
A liquid crystal composition 2-D was prepared by mixing only 1-5, 1-24, and 1-37.

A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, except that liquid crystal compositions 2-C and 2-D were injected into the cell instead of using liquid crystal composition 1-B, and the optical response was The speed was measured. The results are shown below.

Response speed 10℃ 25℃ 40℃2-C
I50 μsec 275 μsec 95
p 5ec2-D 1300 μsec 33
0 μsec 110 μsec Example 2 and Comparative Example 2
As is clearer, the ferroelectric liquid crystal element containing the liquid crystal composition 2-B according to the present invention has improved operating characteristics and high-speed response at low temperatures, and has reduced temperature dependence of response speed. ing.

Example 3 A liquid crystal composition 3-A was prepared by mixing the following parts by weight.

Exemplification Structure Formula % Formula % For this liquid crystal composition 3-A, exemplified compound 1-1.2-
3 in the following parts by weight, respectively, to prepare liquid crystal composition 3-B.
I got it.

exemplification Compound No.

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 liquid crystal composition 3-Bζ, and the optical response speed was determined in the same manner as in Example 1. was measured and the switching state etc. was observed. The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

lOoo 25℃ 40℃Response speed 1280μsec 3307zsec 115
The contrast during this driving at 25° C. was 14 μsec, and a clear switching operation was observed.

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

Instead of using liquid crystal composition 1-B, liquid crystal composition 3-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 optical response speed was measured. The results are shown below.

10℃ 25℃ 40℃ Response speed μsec μsec μ5ec3
-A 2000 530 1583-C1
500380125 3-D 1750 470 145 As is clear from Example 3 and Comparative Example 3, the ferroelectric liquid crystal element containing the liquid crystal composite oxide 3-B according to the present invention has better operating characteristics at low temperatures and faster response. The temperature dependence of the response speed is reduced.

Example 4 Liquid crystal compositions 3-A mixed in Example 3 were mixed with the following exemplified compounds in the weight parts shown below to obtain liquid crystal composition 4-B.

Exemplary Compound Nα Structure Formula Structure Formula Weight Part A ferroelectric liquid crystal device was prepared in the same manner as in Example 1 except that this was used, and the optical response speed was measured in the same manner as in Example 1. The condition 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℃Response speed
1210 μsec 300 μsec 110
Further, the contrast during this driving at 25° C. was 13, a clear switching operation was observed, and the bistability was also good when the voltage application was stopped.

Comparative Example 4 Among the liquid crystal compositions 4-H mixed in Example 4, 3-A was prepared without mixing exemplified compounds No. 1-5, 1-24, and 1-37.
Exemplary compound No. 4-C and exemplified compound No. 2-26. Exemplified compound No. 3-A without mixing 2-54 with exemplified compound No. 4-C and exemplified compound No. ,
1-5. 1-24. A liquid crystal composition 4-D was prepared by mixing only 1-37.

A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, except that liquid crystal compositions 4-C and 4-D were injected into the cell instead of using liquid crystal composition 1-B, and the optical response speed was improved. It was measured. The results are shown below.

lOoC25℃ 40℃ Response speed μ5ectLsec μ5ec4-C
1440360120 4-D 1600 420 135 Example 4
As is clear from Comparative Example 4, the ferroelectric liquid crystal element containing the liquid crystal composition 4-B according to the present invention has improved operating characteristics and high-speed response at low temperatures, and has a lower temperature dependence of response speed. It has been reduced.

Example 5 A liquid crystal composition 5-A was prepared by mixing the following parts by weight.

Exemplified Compound No. Structural formula: For this liquid crystal composition 5-A, Exemplified Compound 1-1.2-
3 in the following weight parts, respectively, to prepare liquid crystal composition 5-B.
I got it.

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 liquid crystal composition 5-B.
The optical response speed 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℃ Response speed 3
65 μsec 90 μsec 35 μsec
Also, the contrast during this drive at 25°C is 14
A clear switching behavior was observed.

Comparative Example 5 Liquid crystal composition 5 in which only exemplary compound No. 2-3 was mixed with 5-A without mixing exemplary compound No. 1-1 of liquid crystal composition 5-B mixed in Example 5. A liquid crystal composition 5-2 was prepared by mixing only exemplary compound No. 1-1 with 5-A without mixing -C with exemplary compound No. 2-3.

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 optical response speed was measured. The results are shown below.

10℃ 25℃ 40℃ Response speed μSeCμsec μ5eC5-A
620 170 525-C440115
40 5-D 510 140 45 As is clear from Example 5 and Comparative Example 5, liquid crystal composition 5 according to the present invention
The ferroelectric liquid crystal element containing -B has improved operating characteristics and high-speed response at low temperatures, and has reduced temperature dependence of the response speed.

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

-A A ferroelectric liquid crystal element was produced in the same manner as in Example 1 except that this was used, and the optical response speed 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℃ Response speed 370 μsec 95 μsec
35 p sec Furthermore, the contrast during this drive at 25° C. was 13, a clear switching operation was observed, and the bistability was also good when the voltage application was stopped.

Comparative Example 6 Among the liquid crystal compositions 6-H mixed in Example 6, exemplified compounds No. 1-5. 1-24. 5 without mixing 1-37
Liquid crystal composition 6-C in which only exemplary compound No. 2-26.2-54 was mixed with -A and exemplary compound No. 2-2
Exemplary compound N for 5-A without mixing 6゜2-54
o, 1-5. 1-24. A liquid crystal composition 6-D was prepared by mixing only 1-37.

A ferroelectric liquid crystal element was prepared in the same manner as in Example 1 except that liquid crystal compositions 6-C and 6-D were injected into the cell instead of using liquid crystal composition 1-B, and the optical response speed was was measured. The results are shown below.

10℃ 25℃ 40℃ Response speed μsec μSeCμ5eC6-C4
9013045 6-D 530 140 45 As is clear from Example 6 and Comparative Example 6, the liquid crystal composition 6-D according to the present invention
A ferroelectric liquid crystal element containing B has improved operating characteristics and high-speed response at low temperatures, and has reduced temperature dependence of response speed.

Example 7 The liquid crystal composition used in Example 1 and Comparative Example 1 was 5i0
A ferroelectric liquid crystal element was created in the same manner as in Example 1, except that the alignment control layer was created only with polyimide resin without using 2. The optical response speed was measured in the same manner as in Example 1. did. The results are shown below.

Response speed 10℃ 25℃ 40℃1
-B 900 μsec 240 μsec
80 μsec1-C1080psec 27
5 B sec 90 μsec1-D 13
00 μsec 370 μsec 105
μsec1-A 1520 μsec 420
μsec 120 μsec As is clear from Example 7, even when the device configuration is changed, the device containing the ferroelectric liquid crystal composition according to the present invention is similar to Example I compared to the device containing other liquid crystal compositions. The low-temperature operating characteristics have been greatly improved, and the temperature dependence of response speed has been reduced.

Examples 8 to 15 8-B-15-H was prepared using each part by weight of the exemplified compounds and liquid crystal compositions shown in Table 1 in place of the exemplified compounds and liquid crystal compositions used in Example 1.3.5. A liquid crystalline composition was obtained. A ferroelectric liquid crystal element was prepared in the same manner as in Example 1 except for using these, and the optical response speed 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 was good, and a monodomain state was obtained. The measurement results are shown in Table 1.

As is clear from Examples 8 to 15, the ferroelectric liquid crystal elements containing liquid crystal compositions 8-B to 15-B according to the present invention have improved operating characteristics and high response speed at low temperatures, and have improved response speed. Temperature dependence is reduced.

〔Effect of the invention〕

A device containing the ferroelectric liquid crystal composition of the present invention is a liquid crystal device having good switching characteristics and improved operating characteristics.
In addition, a liquid crystal element with reduced temperature dependence of response speed 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 are schematic diagrams of an example of an element cell to explain the operation of a ferroelectric liquid crystal element. In the perspective view shown in FIG. 1, 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 I・・・・・・・・・・・・・・・・・・Transmitted light 2nd
In the figure, 1a 1b In Figure 3, 1a 1b 3a 3b 4a Voltage application means... Voltage application means First stable state Second stable state Upward dipole moment Substrate Substrate Ferroelectric liquid crystal layer Liquid crystal molecule dipole moment (on P) 5° correction target specification 6° correction contents specification page 59 is deleted.

Claims (2)

[Claims] (1) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 and R_2 are linear or branched alkyl which may have substituents of C_1 to C_1_8. basis,
X_1 and X_2 are single bonds, -O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, Y_1 is -CH_
At least one compound represented by 2O- or -OCH_2-, m, n is 1 or 2) and the following general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, R_3 is C_1~ A linear or branched alkyl group that may have a substituent of C_1_8, and
＿3 indicates either a single bond, -O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Z is a single bond or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and ▲Mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼. Also, P
indicates 1 to 12. ) A ferroelectric chiral smectic liquid crystal composition, characterized in that it contains at least one of the following compounds. (2) The following general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 and R_2 are linear or branched alkyl which may have substituents of C_1 to C_1_8. basis,
X_1 and X_2 are single bonds, -O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, Y_1 is -CH_
At least one compound represented by 2O- or -OCH_2-, m, n is 1 or 2) and the following general formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) (However, R_3 is C_1~ A linear or branched alkyl group that may have a substituent of C_1_8, and
＿3 indicates either a single bond, -O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Z is a single bond or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and ▲Mathematical formulas, chemical formulas, tables, etc. ▼ is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼. Also, P
indicates 1 to 12. 1.) A liquid crystal element comprising a ferroelectric chiral smectic liquid crystal composition containing at least one of the compounds represented by the following formula, disposed between a pair of electrode substrates.