JPH02279651A - Ferroelectric chiral smectic liquid crystal composition and liquid crystal elements using the same - Google Patents

Abstract

PURPOSE:To obtain a ferroelectric chiral smectic liquid crystal composition which is useful as a liquid crystal display element, because of its excellent response to electric fields by using at least one of acetophenone derivatives. CONSTITUTION:The subject composition is obtained by using at least one of formula I [R1, R2 are 1 to 16C alkyl; X, Y are single bond, O; A is A1, A1-A2; B is B1, B1-B2 (A1, A2, B1, B2 are 1,4-phenylene)] and at least one of other liquid crystal compounds. The amount of the compound of formula I is 1 to 500 pts.wt. per 100 pts.wt. of the liquid crystal composition. The compound of formula I is, for example, 2-(4-octyloxyphenyl-4'-nonylacetophenone. The compound of formula I is obtained by treating a compound of formula II with thionyl chloride and subjected to the Friedel-Crafts reaction with a compound of the formula: B-Y-R2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel liquid crystal compound, a liquid crystal composition containing the same, and a display element using the same. The present invention relates to a novel liquid crystal composition, and a liquid crystal element using the same for use in liquid crystal display elements, liquid crystal-optical shutters, and the like.

[Conventional 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 based on, for example, "Applied Physics Letters" by M. Chadt and W. Helfrich.
Physics Letters”) Vo, 18.
No. 4 (1971゜2.15) P. 127~
128 Voltage Dependent Opti
cal Activity of a Twist
d NematicLiquid Crystal"
This uses a TN (Twisted Nematic) type liquid crystal shown in .

These are based on the dielectric alignment effect of liquid crystals, and due to the dielectric anisotropy of liquid crystal molecules, the average molecular axis direction is oriented in a specific direction by an applied electric field. It is said that the limit of the optical response speed of an element is milliseconds, which is too slow for large-scale flat display applications.On the other hand, when considering cost and productivity, simple matrix In the simple matrix method, an electrode configuration in which scanning electrode groups and signal electrode groups are arranged in a matrix is adopted, and for driving, the scanning electrode groups are sequentially and periodically addressed. A time division driving method is employed in which signals are selectively applied and predetermined information signals are selectively applied in parallel to the signal electrode group in synchronization with address signals.

However, if the above-mentioned TN type liquid crystal is adopted 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 (so-called A finite electric field is also generated at the “half-selected point”.

If the difference between the voltage applied to the selected point and the voltage applied to the half-selected point is sufficiently large (and the voltage threshold required to align the liquid crystal molecules perpendicular to the electric field is set to a voltage value in between,
Although the display element operates normally, the number of scanning lines (N
), the time during which an effective electric field is applied to one selected point (duty ratio) while scanning the entire screen (one frame) decreases at a rate of 17N.

For this reason, when repeated scanning is performed, the effective voltage difference between selected points and non-selected points becomes smaller as the number of scanning lines increases, resulting in a decrease in image contrast and crosstalk. This is a drawback that is difficult to avoid.

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). )
This is an essentially unavoidable problem that arises when driving (that is, repeatedly scanning) using the tin accumulation effect.

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.

Clark (C1
ark) and Lagerwall (Japanese Unexamined Patent Publication No. 107216/1983,
(U.S. Pat. No. 4,367.924, etc.).

As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral smectic C phase (S m C* phase) or H phase (SmH* phase) is generally used.

This ferroelectric liquid crystal has a bistable state consisting of a first optically stable state and a second optically stable state 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 adopting 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,
Significant substantial improvements are obtained over many of the problems of conventional TN type devices mentioned above. 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, but the ferroelectric liquid crystal materials developed to date have sufficient properties for use in liquid crystal devices, including low-temperature operating characteristics and high-speed response. It is hard to say that it has these characteristics.

The following relationship exists between the response time τ, the magnitude of spontaneous polarization Ps, and the viscosity η as shown in the following equation [R1 (where E is the applied electric field). Therefore, to increase the response speed, (
There is a method of (a) increasing the magnitude of spontaneous polarization Ps, (b) decreasing the viscosity η, and (ii) increasing the applied electric field E. The applied electric field has an upper limit because it is driven by an IC or the like, and it is desirable that it be as low as possible.

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

- In ferroelectric chiral smectic liquid crystal compounds that have a large spontaneous polarization, the internal electric field of the cell caused by the spontaneous polarization is also large, and there are many restrictions on device configurations that can achieve a bistable state.

Furthermore, even if the spontaneous polarization is increased unnecessarily, the viscosity tends to increase accordingly, and as a result, it is conceivable that the response speed will not become very fast.

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

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 to be solved by the invention]

An object of the present invention is to provide a liquid crystal composition, particularly a ferroelectric chiral smectic liquid crystal composition, which has a high response speed and reduced temperature dependence of the response speed, in order to make a ferroelectric liquid crystal element practical. , and to provide a liquid crystal element using the liquid crystal composition.

[Means and effects for solving the problem] That is, the first invention of the present invention is based on the following general formula [I]R, -X-A-CH
2C-B-Y-R2[I]I (R1 and R2 each represent an alkyl group having 1 to 16 carbon atoms which may have a substituent, and X and Y each represent a single bond or 10- .A is -A, - or -A,
-A2-, and B represents -B1- or -B1-B2-. AI + A2 + Bl + B2 each represents 1.4-)unisine which may have a substituent. )
The present invention relates to a ferroelectric chiral smectic liquid crystal composition containing at least one type of compound represented by

Further, a second invention is a liquid crystal element characterized in that the liquid crystal composition is used; This relates to a liquid crystal element.

In the compound represented by the general formula [I], R1°R2 are preferably selected from (i) to (iv).

(i) C+=C+a n-alkyl group, more preferably C3-C14 n-alkyl group H3 (ii) (-CH2)mCHCn H2n+1(
However, m is an integer of 1 to 6, and n is an integer of 2 to 8. Moreover, it may be optically active. ) CH.

(fjD +CHz′)-rCH-(-CH2)sO
ctH2t++ (where r is an integer from O to 6, S
is O or 1. Further, t is an integer of 1 to 12.

It may also be optically active. )(iv) −
CH2 CHC It was discovered that the display characteristics were improved and good display characteristics could be obtained.

[Detailed description of the invention]

A general synthesis example of the compound represented by the general formula [I] is shown below.

○ (However, R1+ R2r X+ Y+ A+ B
is as defined above. ) Examples of specific structural formulas of the compound represented by the general formula [I] are shown below.

The ferroelectric chiral smectic liquid crystal composition of the present invention comprises at least one compound represented by the general formula [I],
It can be obtained by mixing with one or more other liquid crystal compounds in an appropriate ratio.

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

Compound No.

H3 H3 ○ H3 H3 * H3 H3 H3! Engineering engineering engineering ＾ ω Ll') O qko engineering Q's r) )〉→o
+CH2) 2 CHC4H9* N N C, H,, 40 crushed C6HI3 ○ C, oH2,O-@-CH2o-@-oc, H,.

C1 □ H1 Toka CH2Osha QC6H13 The compound of the present invention and one or more other liquid crystal compounds, or a liquid crystal composition containing the same (these may be ferroelectric liquid crystal compounds and ferroelectric liquid crystal compositions) (Hereinafter, these are abbreviated as liquid crystal materials.) The compound according to the present invention is preferably mixed in an amount of 1 to 500 parts by weight per 100 parts by weight of the liquid crystal material.

Furthermore, even when two or more compounds of the present invention are used, the blending ratio with the liquid crystal material is preferably 1 to 500 parts by weight of the mixture of two or more compounds of the present invention per 100 parts by weight of the liquid crystal material.

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, 1 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゜Sn○
2 or ITO (Indium-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 An inorganic material insulating layer such as magnesium is formed, and then polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyvaraxylene, polyester, polycarbonate, polyvinyl acecool, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose is formed. An organic insulating material such as resin, melamine resin, Yulia resin, acrylic resin or photoresist resin is used 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 by a solution in which an organic insulating substance is dissolved, or its precursor solution (0.1 to 20% by weight in a solvent, preferably 0% by weight). .2-10%
) using a spinner coating method, dip coating method, screen printing method, spray coating method, roll coating method, etc.
It can be 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 substrate is held between two sheets and the periphery 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 exhibits an S m C aqueous phase (chiral smectic phase) in a wide temperature range including room temperature (especially on the low temperature side).
It is desirable to have high-speed response. Furthermore, it is desired that the temperature dependence of the response speed be small and that the driving voltage margin be wide.

In addition, especially when used as an element, in order to exhibit good uniform alignment and obtain a monodomain state, the ferroelectric liquid crystal should be changed from the Tokichi phase to the ch phase (cholesteric phase) - 8 mA phase (smectic phase) = SmC wood. 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 transmission type, so it 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.
Liquid crystal of phase or SmH* phase is sealed. A thick line 23 represents a liquid crystal molecule, and this liquid crystal molecule 23
is the dipole moment (P) in the direction perpendicular to the molecule
It has 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 short axis direction. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the polarity of the applied voltage will change depending on the voltage applied polarity. It is easily understood that this results in a liquid crystal optical modulation element whose optical properties change.

The liquid crystal cell preferably used in the optical modulation element of the present invention has a sufficiently thin thickness (for example, IOμ or less).
can do. As the liquid crystal layer becomes thinner in this way, the helical structure of the liquid crystal molecules unwinds 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 (34).
Either state b) is taken. In such a cell, the third
As shown in the figure, when an electric field Ea or Eb of different polarity above a certain threshold value is applied by the voltage applying means 31a and 31b,
The dipole moment changes direction upward 34a or downward 34b in response 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. Moreover, when an electric field Eb in the opposite direction is applied, the liquid crystal molecules enter the second stable state 3.
3b and changes the orientation of the molecule, but it remains in this state even after the electric field is turned off. Further, as long as the applied electric field Ea or Eb does not exceed a certain threshold value, the previous orientation state is 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.

Synthesis Example 1 Synthesis of 2-(4-octyloxyphenyl)-4'-nonylacetophenone (Exemplary Compound No. 1-5) (
1) Synthesis of octyl 4-octyloxyphenylacetate 10.0 g (65,7
m mol ), 9.95 g of 85% potassium hydroxide
(150.7 mmol), n-butanol 100 m
f and 10 m of octyl iodide while stirring at room temperature. ! was added. Then, while heating and refluxing, 15 ml of octyl iodide was added dropwise, and the mixture was heated and refluxed for 2 hours. Thereafter, the mixture was stirred at room temperature overnight and insoluble materials were filtered off. Insoluble matter was washed with ethanol, and this washing liquid was added to the filtrate and evaporated under reduced pressure. Then, water was added and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. After solvent distillation, toluene/n
- Purified by silica gel column chromatography using hexane (1/2) as a developing solvent. 15.84 g (yield 64.0%) of octyl 4-octyloxyphenylacetate was obtained.

(2) Synthesis of 4-octyloxyphenylacetic acid Octyl 4-octyloxyphenylacetate 6.38g (16,9
mmol), ethanol 75 m Il, water 25 mj
? , 6.02 g of 85% potassium hydroxide was stirred at room temperature, and then heated under reflux for 2 hours. After the reaction, part of the solvent was distilled off, water was added, and about 8 ml of concentrated hydrochloric acid was added to make the solution acidic with hydrochloric acid (pH ~ 2).
). The precipitated crystals were extracted with ethyl acetate, washed with water, and then dried over anhydrous sodium sulfate. After filtration, the solvent was distilled off and recrystallized from hexane to obtain 3.02 g (yield: 67.4%) of 4-year-old ctyloxyphenylacetic acid.

(3) Synthesis of 4-octyloxyphenylacetic acid chloride 1.2 g of 4-octyloxyphenylacetic acid and 10 ml of thionyl chloride were added, and the mixture was heated and stirred at 80°C for 4 hours.

After the reaction was completed, excess thionyl chloride was distilled off under reduced pressure. Furthermore, benzene was added and distilled off under reduced pressure. Do this operation several times. Then, heptane was added and evaporated under reduced pressure to give 4-
Octyloxyphenylacetic acid chloride was obtained.

(4) 2-(4-octyloxyphenyl)\-4'-
Synthesis of nonylacetophenone/nonylbenzene 1.11
20 mj7 of carbon disulfide is added to g (5,46 mmol), and 0.85 g (6,37 mmol) of ground aluminum chloride is added while stirring at -8°C (in an ice salt bath). While stirring at this temperature, 1.28 g (4.55 mmol) of 4-octyloxyphenylacetic acid chloride is added dropwise. After the addition, the mixture was stirred at -8°C for 3 hours. Then ice 5
0 g and 12 ml of concentrated hydrochloric acid. It was then extracted with ethyl acetate, washed with water, and dried over anhydrous sodium sulfate. After filtration, the solvent was distilled off under reduced pressure and purified by silica gel column chromatography using benzene as a developing solvent to obtain 0.64 g of 2-(4-octyloxyphenyl)-4'-nonylacetophenone (yield 31.2%). ) was obtained.

Phase transition temperature (0C) 00.5 Synthesis Examples 2 to 9 Synthesis Examples 2 to 9 shown below using the same synthesis method as Synthesis Example 1
The compound was obtained.

Growth example Exemplary compound Example 1 Mix the following exemplified compounds in the following parts by weight and make a liquid. Composition A was created.

Exemplary compound no.

Structural Formula Phase Transition Temperature (° C.) Further, the following exemplary compounds were mixed with the liquid crystal composition A in the weight parts shown below to prepare a liquid crystal composition B.

Exemplified Compound No. Structural Formula Parts by Weight Next, two glass plates with a thickness of 0 and 7 mm were prepared, an ITO film was formed on each glass plate, a voltage application electrode was created, and 5i02 was deposited on top of this to form an insulating layer. A 0.2% isopropyl alcohol solution of a silane coupling agent [KBM-602, manufactured by Shin-Etsu Chemical Co., Ltd.] was applied onto a glass plate for 15 seconds using a spinner with a rotation speed of 200 Or, p, m, to perform surface treatment.

After that, a heat drying treatment was performed at 120° C. for 20 minutes.

Polyimide resin precursor [Toshi @) SP-510] 1.5
% dimethylacetamide solution at a rotational speed of 200°r, p,
It was applied for 15 seconds using a 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 approximately 250.

This fired coating was rubbed with acetate flocked cloth, then washed with isopropyl alcohol solution, and alumina beads with an average particle size of 2 μm were sprinkled on one glass plate, so that the rubbing axes of each plate were aligned with each other. The glass plates were glued together using an adhesive sealant [Rixon Bond (Chisso)] so that they were parallel to each other, and dried by heating at 100°C for 60 minutes to create a cell.The cell thickness of this cell was determined by Approximately 2 as measured by phase plate
It was μm.

By injecting liquid crystal composition B in an isotropic liquid state into this cell and slowly cooling it from the Tokichi phase to 25°C at a rate of 20°C/h,
A ferroelectric liquid crystal device was created.

Using this ferroelectric liquid crystal element, the optical response (transmitted light amount change 0 to 90%) under crossed Nicols is detected by applying a voltage of peak-to-peak voltage Vpp = 20V, and the response speed (hereinafter referred to as optical response) is detected. speed) was measured.

The results are shown below.

15℃ 25℃ 35℃ Response speed 124 μsec 84 μ
sec 70 μsec Comparative Example 1 A ferroelectric liquid crystal element was prepared in the same manner as in Example 1 except that the liquid crystal composition A mixed in Example 1 was injected into the cell, and the optical response speed was measured.

The results are shown below.

15°C25°C 35°C response speed
155 μsec 100 μsec
80 μsec Example 2 In place of Exemplified Compound 1-2.1-5 used in Example 1, the following Exemplified Compounds were mixed in the weight parts shown below to prepare Liquid Crystal Composition C.

Exemplary Compound No. Structural Formula Part by Weight All except for using this liquid crystal composition (A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, and the optical response speed was measured in the same manner as in Example 1. did.

The measurement results are shown below.

15'C 25°C 35°C Response speed 123 μ5ec 82 μ5ec 71 μsec Example 3 In place of Exemplified Compound 1-2.1-5 used in Example 1, the following exemplary compounds were mixed in the weight parts shown below, A liquid crystal composition was created.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. did.

The measurement results are shown below.

15°C 25°C 35°C Response speed 144 p 5 ec 90 μ5 ec 80 μsec Example 4 In place of Exemplified Compound 1-2.1-5 used in Example 1, the following exemplary compounds were mixed in the weight parts shown below, A liquid crystal composition E was prepared.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. did.

The measurement results are shown below.

15°C 25°C 35°C Response speed 133 μsec 85 μ5ec 74 μsec Example 5 Exemplary compound 1-2 used in Example 1. Liquid crystal composition F was prepared by mixing the following exemplified compounds in the weight parts shown below in place of 1-5.

Exemplary Compound No. Structural Formula Part by Weight All except for using this liquid crystal composition (A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, and the optical response speed was measured in the same manner as in Example 1. did.

The measurement results are shown below.

15°C 25°C35°C Response speed 134 μsec 86 μs
ec 74 μsecυ Example 6 In place of Exemplified Compound 1-2.1-5 used in Example 1, the following exemplary compounds were mixed in the weight parts shown below to prepare a liquid crystal composition G.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. did.

The measurement results are shown below.

15°C 25°C 35°C response speed
133 μsec 85 μsec
73 μsec Example 7 The following exemplified compounds were mixed in the following parts by weight to form a liquid crystal composition H.
It was created.

Exemplified Compound No. Structural Formula Parts by weight Furthermore, the following exemplary compounds were mixed with this liquid crystal composition H in the weight parts shown below to prepare a liquid crystal composition I.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. and observed the switching state.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15°C25°C35°C Response speed 430 μsec 257 p
sec 190 μsec Comparative Example A ferroelectric liquid crystal element was prepared in the same manner as in Example 1 except that the liquid crystal composition H mixed in Example 7 was injected into the cell, and the optical response speed was measured.

The results are shown below.

15°C 25°C 35°C response speed
450 μsec 270 psec
1951t sec Example 8 In place of Exemplified Compound 1-3.1-17 used in Example 7, the following exemplary compounds were mixed in the weight parts shown below to prepare Liquid Crystal Composition J.

Exemplary Compound No. Structural Formula Part by Weight All except for using this liquid crystal composition (A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, and the optical response speed was measured in the same manner as in Example 1. 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.

15°C 25°0 35°C response speed
360 μsec 221 μsec
172 μsec Also, clear switching behavior was observed during driving, and good bistability was observed when voltage application was stopped.

Example 9 In place of Exemplified Compound 1-3.1-17 used in Example 7, the following Exemplary Compounds were mixed in the weight parts shown below to prepare Liquid Crystal Composition K.

Exemplary compound No. Structural formula Weight part! -10 All except that a liquid crystal composition was used (a ferroelectric liquid crystal element was created in the same manner as in Example 1, the optical response speed was measured in the same manner as in Example 1, and the switching state was observed. did.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15℃ 25℃ 35℃ Response speed 355 p sec 215
p sec 169 μsec Further, a clear switching operation was observed during driving, and good bistability was observed when voltage application was stopped.

Example 10 In place of Exemplified Compound 1-3.1-17 used in Example 7, the following exemplary compounds were mixed in the weight parts shown below to prepare a liquid crystal composition.

Exemplary Compound No. Structural Formula Parts by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. and observed the switching state.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15°C 25°C 35°C response speed
390μsec 228μsec
170 μsec Also, clear switching behavior was observed during driving, and good bistability was observed when voltage application was stopped.

Example 11 In place of Exemplified Compound 1-3.1-7 used in Example 7, the following exemplary compounds were mixed in the weight parts shown below to prepare a liquid crystal composition M.

A ferroelectric liquid crystal element was prepared in the same manner as in Example 1, and the optical response speed was determined in the same manner as in Example 1. The switching state was observed.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15°C 25°C 35°C response speed
396 μsec 249 μsec
180 p sec Furthermore, a clear switching operation was observed during '' driving, and good bistability was observed when the voltage application was stopped.

Example 12 In place of Exemplified Compound 1-3.1-17 used in Example 7, the following exemplary compounds were mixed in the weight parts shown below to prepare a liquid crystal composition N.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. and observed the switching state.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15°C 25°C 35°C response speed
360 μsec 242 psec
170 μsec Also, clear switching behavior was observed during driving, and good bistability was observed when voltage application was stopped.

Example 13 In place of Exemplified Compound 1-3.1-17 used in Example 7, the following Exemplified Compounds were mixed in the weight parts shown below to prepare Liquid Crystal Composition 0.

Exemplary Compound No. Structural Formula Part by Weight A ferroelectric liquid crystal device was prepared in the same manner as in Example 1, except that this liquid crystal composition was used, and the optical response speed was measured in the same manner as in Example 1. and observed the switching state.

The uniform alignment within this liquid crystal element was good, and a monodomain state was obtained.

The measurement results are shown below.

15°C25°C35°C Response speed 3461t sec 235
p sec 165 μsec Also, clear switching behavior was observed during driving, and good bistability was observed when voltage application was stopped.

Example 14 In place of the 1.5% dimethylacetamide solution of the polyimide resin precursor used in Example 1, a 2% aqueous solution of polyvinyl alcohol resin [PUA-117 manufactured by Kuraray ■] was used. A dielectric liquid crystal element was prepared, and the optical response speed was measured in the same manner as in Example 1.

The results are shown below.

15°C25°0 35°C 117 μsec 83 μsec ##p
sec Example 15 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 SiO2 used in Example 1. The optical response speed was measured in the same manner.

The results are shown below.

15°C25°C35°C 115μsec 82μsec 70
μsec Example 14. As is clear from Example 15, even when the device configuration is changed, the device containing the ferroelectric liquid crystal composition according to the present invention has significantly improved low voltage actuation characteristics and response speed, as in Example 1. Temperature dependence is reduced.

〔Effect of the invention〕

A device containing the liquid crystal compound of the present invention can be a liquid crystal device with good switching characteristics, improved low-temperature operation characteristics, and a liquid crystal device with reduced temperature dependence of response speed.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an example of a liquid crystal element using ferroelectric liquid crystal. 2 and 3 are perspective views schematically showing an example of an element cell for explaining the operation of a ferroelectric liquid crystal element. In FIG. 1, 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 I0 ・・・・・・・・・
・・・・・・・・・Incoming light!・・・・・・・・・・・・
......Transmitted light in Figure 2, 2ja...Curved...Concave...Curved, Substrate 1b 24...In Fig. 3, 1a 1b 3a 3b 34 a... 34b... a b Substrate Ferroelectric liquid crystal layer Liquid crystal molecule dipole moment (P) Voltage application means Voltage application means First stable state Second Steady state Upward dipole moment Downward dipole moment Upward electric field Downward electric field

Claims (2)

[Claims] (1) The following general formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [I] (R_1 and R_2 each represent an alkyl group with 1 to 16 carbon atoms that may have a substituent, X, Y each represents a single bond or -O-.A represents -A_1- or -A_1
-A_2-, B is -B_1- or -B_1-B
_2- is shown. A_1, A_2, B_1, and B_2 each represent 1,4-phenylene which may have a substituent. ) A ferroelectric chiral smectic liquid crystal composition containing at least one compound represented by: (2) A liquid crystal device comprising the ferroelectric chiral smectic liquid crystal composition according to claim 1 disposed between a pair of electrode substrates.