JPH02295943A - Liquid crystal compound, liquid crystal composition containing same compound and liquid crystal element using same composition - Google Patents

Abstract

NEW MATERIAL:A liquid crystal compound shown by formula I [R<1> is 1-18C alkyl (which may be replaced); R<2> is 1-12C alkyl; X is single bond, O, OC(=O)C =O or C(=O)O or OC(=O); Y is single bond, C(=O), OC(=O), CH2O or OCH2; A and B are each phenylene, bifunctional pyridazine or cyclohexylene; l and m are 0-2; n is 1 or 2 and l+m+n is 2 or 3; C* is asymmetric carbon]. EXAMPLE:4-Deoxybenzoic acid-4'-[4''-(3-trifluoromethylnonanoyl)biphenyl]. USE:A liquid crystal compound having improved responding characteristics to electric field. A liquid crystal element usable for liquid crystal display element, liquid crystal-optical shutter, etc. PREPARATION:For example, a compound shown by formula II is reacted with a compound shown by formula III in the presence of AlCl3 to give a compound shown by formula I wherein Y is single bond or OCH3.

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 liquid crystal element using the same, and more specifically relates to a novel liquid crystal compound containing the same, and a liquid crystal 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 light shutters, and the like.

[Prior Art] Liquid crystals have conventionally been applied as electro-optical elements in various fields. Most of the liquid crystal elements currently in practical use are, for example, M-Shut (Supplementary).

5chad L) and W Helfrich (LHel)
“Applied Physics Letters” by Frich)
”) Vo, 18. No, 4 (197L, 2.15)
P, 127~+28 “VolLage Depen
dentOptical Activity of
a Twisted Nematic 1i
TN (Twist) shown in “quidCrystal”
ed Ne5atic) type 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 in which a scanning electrode group and a signal electrode group are arranged in a matrix is adopted, and in order to drive the electrode group, an address signal is selectively and periodically applied to the scanning electrode group, and the signal electrode group is A time division driving method is adopted in which a predetermined information signal is selectively applied in parallel in synchronization with an address signal.

However, if the above-mentioned TN type liquid crystal is adopted as an element with such a driving method, there will be areas where the scan electrode is selected and the trust electrode is not selected, or an area where the scan electrode is not selected and the signal electrode is selected ( A finite electric field is also applied to the so-called "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 value required to align the liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage value, then 5.
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 (1 frame) decreases at a rate of 1/H.

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 low 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 (liquid crystal molecules are in a stable state when they are aligned horizontally with respect to the electrode surface, and they are aligned vertically only when an electric field is effectively applied). )
This is essentially an unavoidable problem that arises when driving using the temporal accumulation effect (that is, scanning repeatedly).

In order to improve this point, voltage averaging method, dual frequency driving method, multiple matrix method, etc. have already been proposed, or all of them are insufficient and it is difficult to increase the screen size and density of display elements. Currently, the number of scanning lines has reached a plateau because the number of scanning lines cannot be increased sufficiently.

Clark ((:
1ark) and Lagerwall (Japanese Unexamined Patent Publication No. Sho! dt-107216, US Pat. No. 4:167924, etc.).

Chiral smectic C is generally used as a bistable liquid crystal.
A ferroelectric liquid crystal having a phase (Sac' phase) or an H phase (Salt'' phase) is 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. 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. Additionally, this type of liquid crystal has the 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 due to the direct interaction between the spontaneous polarization of ferroelectric liquid crystals and the applied electric field. This is to induce the transition of , which is 3 to 4 orders of magnitude faster than the response speed due to the effect of dielectric anisotropy and electric field.

In this way, ferroelectric liquid crystals have extremely excellent properties and are potentially very good, and by utilizing these properties, many of the problems of conventional TN-type devices mentioned above can be overcome, and it can be used to This results in significant improvements. # It is expected that it will 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,5 but the ferroelectric liquid crystal materials developed to date have excellent chemical properties for use in liquid crystal elements, including low-temperature operating characteristics and high-speed response. It is hard to say that it has these characteristics.

There exists a relationship between the response time, the magnitude of spontaneous polarization Ps, and the viscosity η as shown in the following formula [11] % formula % [] (where E is the applied electric field). Therefore, in order to increase the response speed, (a) increase the magnitude of spontaneous polarization Ps (b) viscosity η
There is a method of increasing the applied electric field E. However, the applied electric field has an upper limit because it is driven by (2) c, etc., and it is desirable that it be as low as possible.

Therefore, it is actually necessary to reduce the viscosity η or to 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 tends to be more restrictions on the device configuration that can take the bistable state y6.

Moreover, 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 1, for example, 5 to 40 degrees Celsius, the response speed will generally vary by a factor of 20, and the current situation may indicate that the limit of adjustment by drive voltage and frequency is exceeded. be.

As mentioned above, in order to put ferroelectric liquid crystal elements 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. Ru.

[Problem to be solved by the invention] The purpose of the present invention is to improve the temperature dependence of the response speed of the strongly electrostatic liquid crystal element f. liquid crystal compositions, particularly ferroelectric chiral smectic liquid crystal compositions, and the liquid crystal compositions J&
The purpose of the present invention is to provide a liquid crystal element that uses a liquid crystal device.

[Means for Solving the Problem] and [Operation] That is, the first invention of the present invention is a liquid crystal compound represented by the following general formula (I).

(I) (wherein 11 is a linear or branched alkyl group having 1 to 18 carbon atoms which may have a substituent, R2 is an alkyl group having 1 to 12 carbon atoms, and X is a single Combine.

(E) Shows those independently selected from the widths of -.

2 represents O, l or 2, m represents o, l or 2, n represents 1 or 2, and 12 + m + n represents 2 or 3. CII represents an asymmetric carbon atom. ) Moreover, the second invention is a strong chiral smectic liquid crystal composition, which is characterized by containing at least one kind of liquid crystalline compound represented by the general formula (I).

Furthermore, a third invention is characterized in that a ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the general formula (I) is disposed between a pair of electrode substrates. It is a liquid crystal element that

The present inventors have discovered that by using the above-mentioned liquid crystal assembly and liquid crystal element using the same, various properties such as high-speed response and reduced temperature dependence of response speed can be improved, resulting in good display characteristics. It was discovered that this can be obtained.

The present invention will be explained in detail below.

In the liquid crystalline compound represented by the general formula (I),
is preferably a single bond, -O--0C--CO-, -
C-, and R2 is an alkyl group having 1 to 12 carbon atoms, or preferably a linear alkyl group.

Further, R' is a linear or branched alkyl group which may have a substituent having 1 to 18 carbon atoms, but even more preferably, R1 is selected from the following (1) to (in). To be elected.

i) n-alkyl group having 1-18 carbon atoms ii) ? 113 +C11□h-Cold-(: bit a□1 (However, a is an integer from 1 to 7, and b is an integer from 2 to 9. Also,
It may be optically active. )+ii) (However, r is an integer from 0 to 7, S is 0 or l, and t is 1
~14 integer. Further, it may be optically active. ) The liquid crystalline compound represented by the above general formula (1) is preferably used in the application filed by the present applicant et al.
485 and Japanese Patent Application No. 63-37624), it is synthesized from an optically active intermediate of a carboxylic acid having a trifluoromethyl group as an optically active group of the following general formula (II).

(In the formula, R is an alkyl group having 1 to 12 carbon atoms, 2υ Next, one example of a method for synthesizing the liquid crystalline compound represented by the general formula (I) is shown below.

In general formula (I), i) Y is a single bond, -0C112- i) Y is 100 CI [20-, R' o, 1) -CO2-.

C-) iii) In the case of Y or 10C- four 〇 C.F.

■-2) ■-3) However, in the above formula, R', R2, X, Y, A, B.

(1 and m are as defined above.

Next, the specific structure of the liquid crystal compound represented by the general formula (I) is shown below.

■-6) Ni■ Ni9) ■ l -17) ■ I -19) l -2O) υ υ υ ■ 11l) I -12) Ni I -14) Ni I -2l) I -22) l - 25) I -24) ■ υ υ υ I -26) l -27) l -23) ■ l -50) Ni I -57) I -58) ■ ■ 14O) υ υ I -52) I -53 ) I -54) I -55) 14l) dI -45) I -44) l -43) υ υ υ ■ ■ ni■ ■ ■ ■ r -5a) I -39) ■ 16O) υ υ υ υ I -31) ■ I -33) ■ I -35) I -6l) ■ l -65) I -64) l -63) υ ■ ■ l -63) I -69) l -7O) I -76 ) l -77) l -73) I -79) Niυ ■ -7l) I -72) l -75) I -74) l -73) ■ ■ υ υ υ υ υ The liquid crystal composition of the present invention At least t +i of the liquid crystalline compound represented by general formula (I) and another liquid crystalline compound Q1
By mixing seeds or more in an appropriate ratio, 1! I can do a lot of things. Further, the liquid crystal composition according to the present invention is preferably a ferroelectric liquid crystal composition, particularly a ferroelectric chiral smectic liquid crystal set Jjl.

Next, specific examples of other liquid crystal compounds used in the present invention are shown below.

(l) (ios) υ υ υ (1:13) (1:16) (14g) (isi) F (l)6) υ υ N υ (ZOS) (ZOa) (2:10) (2: 12) (2 pieces 3) (2:16) (2:17) Ct *H* s 0-o-CH20+OCa HI3
The liquid crystal 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 will be referred to as liquid crystal compounds. (abbreviated as “material”) is the liquid crystal material! (It is preferable that the amount of the liquid crystalline compound according to the present invention is 1 to 500 parts by weight per 10 parts by weight.

Furthermore, when two or more types of liquid crystal compounds of the present invention are used, the blending ratio with the liquid crystal material is 1 to 500 beads of a mixture of two or more types of liquid crystal compounds according to the present invention per 100 parts by weight of the liquid crystal material described above. It is preferable to set it as part.

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal element having a ferroelectric liquid crystal layer of 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 have In and 0 U, respectively.

SnO or ITO (Indium Tin Oxide) "J's 6"
．． A transparent electrode 3 made of H&I is coated. On top of that, a thin film of polymer such as polyimide is rubbed with gauze or acetate flocked cloth to form an insulating orientation control M4 that arranges the liquid crystals in the upholstery direction. In addition, as an insulating material, for example, silicon nitride, hydrogen-containing silicon carbide, silicon oxide, I11 element oxide, hydrogen-containing boron nitride, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide. An insulating layer made of aluminum or magnesium fluoride is formed, and then polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylene, polyester,
Insulating orientation control with two layers using organic insulating materials such as polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene 5 cellulose resin, melamine resin, Yurya resin, acrylic resin, and photoresist resin as the orientation control layer. A layer 4 may be formed, and an insulating orientation control layer made of an inorganic material or an insulating orientation control layer made of an organic material may be formed as an intermediate layer.If this insulating orientation control layer is inorganic, it can be formed by a vapor deposition method or the like. , if it is an organic type, a solution in which an organic insulating material is dissolved or its precursor solution (0.1 to 20% by weight in a solvent, preferably 0.2
~+f7% by weight) by a spinner coating method, dip coating method, screen printing method, spray coating method, roll coating method, etc., and then cured and formed under predetermined curing conditions (e.g., heating at F). I can do it.

The thickness of the insulating orientation control layer 4 is usually 30 to 1JL, preferably 30 to 1JL, more preferably 50
~1000 people are suitable.

These two glass substrates 2 are kept at an arbitrary distance by a spacer 5. For example, there is a method in which spacers such as silica beads or alumina beads having a predetermined diameter are sandwiched between two glass substrates, 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 1 in which the ferroelectric liquid crystal is sealed generally has a thickness of 0.5 to 20 Jim, preferably 1 to 5 Jim.

Further, it is desirable that this ferroelectric liquid crystal has an S■C8 phase (chiral smectic phase) in a wide temperature range including room temperature (particularly on the low temperature side) and has high-speed response. Furthermore, it is desired that the temperature dependence of the response speed be small and that the drive voltage margin be wide.

In addition, especially when used as an element, in order to exhibit good uniform alignment and obtain a monodomain state, the ferroelectric liquid crystal must be changed from the tomoyoshi phase to the ch phase (cholesteric phase) - 3 A phase (smectic phase) - It is desirable to have a phase transition series called 3s(:' phase (chiral smectic phase).

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

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

The first W is a transmission 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 Into, SnO, 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 an S+ layer 22 of liquid crystal molecules is oriented perpendicular to the glass surface.
A liquid crystal of sC" phase or 5all" phase is sealed. 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. When a voltage higher than a certain dark value is applied between the electrodes on the substrates 21a and 21b, the liquid crystal molecules 2
The helical structure of 3 unravels, and the dipole moment (P□)2
The alignment direction of the liquid crystal molecules 23 can be changed so that all of the liquid crystal molecules 23 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 polarity of the applied voltage changes. 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, +01L or less).
can do. As the liquid crystal layer becomes thinner, 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 (34a). 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 dark value is applied by the voltage applying means 31a and 31b, the dipole moments 1~ are directed upward 34a or downward depending on the electric field vector of the electric field Ea or Eb. 34b, and accordingly the liquid crystal molecules are in the first stable state ff,
33a or the second stable state: l:lb.

There are two advantages of using such a ferroelectric liquid crystal element as an optical modulation element as mentioned above.

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, for example with reference to FIG. 3, the electric field Ea
When the voltage is applied, the liquid crystal molecules are oriented in the first stable state if+33a, or this state y ball is stable even when the electric field is turned off. Moreover, when an electric field εb in the opposite direction is applied, the liquid crystal molecules are oriented to the second stable state 33b and the orientation of the molecules is changed.
It remains in this state even if the electric field is turned off. Also, as long as the electric field Ea or Eb does not exceed certain values,
Each is still maintained in its previous orientation.

[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 Production of 4-decyloxybenzoic acid 4'-(4''-(3-trifluoromethylnonanoyl)biphenyl) (1-1) 4-decyloxybenzoic acid 4'-(4''-(3-trifluoromethylnonanoyl)biphenyl) (l-1)
4″-(3-trifluoromethylnonanoyl)biphenyl) was produced.

C.F.

Step 1) Production of 4-acetoxy-4'-(3-)-lifluoromethylnonanoyl)biphenyl (+)-3-Trifluoromethylnonanoic acid 0.55g and thionyl chloride 2x2 were mixed and stirred. After reacting at 80°C for 1.5 hours, excess thionyl chloride was distilled off to obtain 0.59 g of 3-trifluoromethylnonanoic acid chloride.

Next, 5ml of disulfide jRA! While stirring the mixture of 0.5 Ig of 4-acetoxybiphenyl, 0.59 g of 3-trifluoromethylnonanoic acid chloride was added, and 0.57 g of anhydrous aluminum chloride was added. After the reaction was completed, the mixture was extracted into ice water. The mixture was made acidic by adding hydrochloric acid, and then extracted using diethyl ether. This ether solution was washed with an aqueous sodium bicarbonate solution, dried over anhydrous sodium sulfate, and purified by column chromatography. (Mobile phase: hexane/ethyl acetate = 8/I) Yield 0. 0.3 g of 4-acetoxy-4'-(3-trifluoromethylnonanoyl)biphenyl obtained in step 2) 4-(3-trifluoromethylnonanoyl)-4'-biphenol production process l) was dissolved in diethyl ether 5■P, n-butylamine 0.1
After the completion of the reaction, the mixture was extracted with water, acidified with hydrochloric acid, and extracted with diethyl ether. The product was purified by thin layer chromatography (developing solvent: hexane/ethyl acetate = 4/1), 0.25 g.
Obtained the objective.

m, p, 85-87°C Step C) Production of 4-decyloxybenzoic acid 4'-(4''=(3-trifluoromethylnonanoyl)biphenyl) Mixing 0.24 g of 4-decyloxybenzoic acid and thionyl chloride LLR After reacting at 80°C for 1.5 hours,
Excess thionyl chloride was distilled off to obtain 0.19 g of 4-decyloxybenzoic acid chloride.

Next, 0.25 g of 4-(3-trifluoromethylnonanoyl)-4'-biphenol obtained in step 2) and triethylenediamine o, tsg were dissolved in dry tetrahydrofuran, followed by 0.25 g of 4-decyloxybenzoic acid chloride. 19g
was added, stirred at 50°C for 2 hours, and then added with sodium hydride 5
01 g was added, and the mixture was heated under reflux for 2.5 hours. After the solvent was distilled off, the residue was extracted with water, extracted with diethyl ether, and purified by thin layer chromatography. (@Opening solvent: hexane/ethyl acetate = 4/1) The obtained target product was recrystallized with 2 mR of hexane.

Yield: 0.17g.

[α]2'-18,8 (solvent, methylene chloride) Phase transition temperature (°C) CF.

Example 2 4′-decyloxy-4-biphenylcarboxylic acid 4″-
Preparation of (3-trifluoromethylnonanoyl)phenyl ester (I-51) 4'-decyloxy-4-biphenylcarbonylli@4''-(3-
Trifluoromethylnonanoyl) phenyl ester was produced.

Step 1) Production of 4-(3-trifluoromethylnonanoyl)anisole (-)-3-)-lifluoromethylnonanoic acid 0.52 g
3 ml of thionyl chloride was reacted at 80°C for 1.5 hours,
0.52 g of 3-trifluoromethylnonanoic acid chloride was obtained.

Next, carbon disulfide 5Ili), anisole 0.23 g and 3-trifluoromethylnonanoic acid chloride 0.52
Add 0.51 g of anhydrous aluminum chloride to the mixture of
The mixture was heated under reflux for 1 hour. After the reaction was completed, the mixture was cooled with water, and cold water and concentrated hydrochloric acid were added thereto to decompose the aluminum chloride complex.

Next, it was extracted with diethyl ether, washed with an aqueous sodium bicarbonate solution, and then dried over anhydrous sodium sulfate.

The solvent was distilled off under reduced pressure and distilled under reduced pressure (200°C, 0:1 m
m11g), yield 0.45g, yield 6
4-(3-trifluoromethylnonanoyl) at 7.5%
I got anisole.

Step 1 2) Production of 4-(3-trifluoromethylnonanoyl)phenol 0.24g of 4-(3-)-lifluoromethylnonanoyl)anisole was dissolved in 10 mβ of acetic acid, then 47%
Hydrogen bromide (fi2mj) was added thereto and the reaction was carried out at 130°C for 13 hours. After the reaction was completed, cold water was added and extraction was performed with diethyl ether. The obtained ether layer was washed with an aqueous sodium bicarbonate solution, dried over sodium sulfate, and the solvent was distilled off under reduced pressure to obtain 4-(3-trifluoromethylnonanoyl)phenol in a yield of 0.23 g and a yield of 98. .9
Obtained in %.

■Step 3) 4-decyloxy-4'-biphenylcarboxylic acid 4"
-Preparation of (3-trifluoromethylnonanoyl)phenyl ester 4-decyloxy-4'-biphenylcarboxylic acid 0.3
To 19g, add 1.5w of thionyl chloride and 1.5w of R at 80°C.
After reacting for an hour, excess thionyl chloride was distilled off.

The obtained acid chloride was mixed with 0.23 g of 4-(3-trifluoromethylnonanoyl)phenol, 0.17 g of triethylenediamine, and 7 L of dry tetrahydrochloride (1 mβ
After reacting at 50°C for 2 hours, 0.05g of lithium hydride (60%) was added, and the mixture was further heated at 70°C for 26 hours.
The reaction was allowed to proceed for 5 hours. After the reaction was completed, tetrahydrofuran was distilled off under reduced pressure, and the solution was acidified with 3N hydrochloric acid and extracted with dichloromethane. After drying the obtained organic layer with sodium sulfate,
The solvent was distilled off, and the residue was purified by thin layer chromatography. Further, recrystallization was performed with ethanol to obtain 4-decyloxy-4'-biphenylcarboxylic acid 4''-(3-trifluoromethylnonanoyl)phenyl ester:
log, yield of 63.3%.

[α]:' +l:1.9 (to 1.06.C
llCl, ) Phase transition temperature (°C) Exemplary compound no.

Structural formula Sn2'': Smectic phase (unidentified) Example 3 The following liquid crystal compound No. 248 was mixed with the compound (1-31) produced in Example 2 to prepare a liquid crystal composition A.

Phase transition temperature (°C) Liquid crystal composition A Exemplary compound No. 248 Two glass plates with a thickness of 0.7 txm were prepared, an ITO film was formed on each glass plate, a voltage application electrode was created, and On top of this, Sio2 was applied with JR to form an insulating layer. Spread 0.2% isopropyl alcohol solution of silane coupling agent [KBM-602, Shin-Etsu Chemical Co., Ltd.] onto a glass plate using a spinner with a rotation speed of 2000 r, p, i.
5 Shouma nuri! τj and surface treatment was performed. After this 120°
A heating drying process was performed at C for 20 minutes.

Furthermore, a polyimide resin precursor (Toshi Hoso, 5p-510) was placed on a glass plate with a surface-treated ITO film.
1.5% dimethylacetamide solution at 2000 rotations.
The coating was applied for 15 seconds using a r, 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 approximately 250.

After firing, the film was rubbed with acetate flocked cloth, then washed with isopropyl alcohol solution, and alumina beads with an average particle size of 2 pm were sprinkled on one glass plate. Glue the glass plates together using an adhesive sealant (Chisso Hosei, Rixon Bond) so that they are in line with each other, and hold for 60 minutes.
A cell was prepared by heating and smoking at 100°C. When the cell thickness of this cell was measured using a Berek phase plate, it was approximately 2 m thick.

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

Using this ferroelectric liquid crystal element, the spontaneous polarization magnitude Ps and the peak-to-peak voltage V, by applying a voltage of = 20V, the optical response under crossed Nicols (m light passing amount change 0 to 90%) was detected and the response speed (hereinafter referred to as optical response speed) was measured. The results are shown below.

The optical response speed of liquid crystal composition A Exemplified Compound 248 is 89 μsec (6
0°C), the response characteristics were improved by adding the liquid crystalline compound according to the present invention, and the liquid crystallinity in the low temperature range was also improved.

Example 4 The following exemplified compounds were mixed in the following parts by weight to prepare liquid crystal composition B.
It was created.

Exemplary compound no.

Structural Formula Further, the compound el (l-1) produced in Example 1 was mixed with this liquid crystal composition B in the weight parts shown below to prepare a liquid crystal composition C.

Structural formula Weight part LCD set r & object B The phase transition temperature ("C) is shown below.

Liquid crystal composition B Cryst, Sac'-on SmA 1 Ch -> Is o.

Liquid crystal jil I & thing C CrysL, -) Sac"-> SmA -> Ch
-n 1so.

In addition, except for injecting liquid crystal compositions B and C into the cell, all
A ferroelectric liquid crystal element was produced in the same manner as in Example 3, and it was found that the liquid crystal element using liquid crystal composition C was
Compared to liquid crystal devices using 2000 µm, the alignment has been improved and the contrast has also been improved.

Example 5 The following exemplified compounds were mixed in r parts by weight to prepare a liquid crystal composition.

Exemplary compound No. Structural formula % Formula % ::) Structural formula weight part Structural formula % Formula % 14) Furthermore, the following parts by weight of the compound RO 31) produced in Example 2 were mixed with this liquid crystal composition. death.

A liquid crystal composition E was prepared.

liquid crystal composition The phase transition temperature (°C) is shown below.

Liquid crystal composition D 4 10 576:178Crys
', →Sm3 →Sac →Ss^ →N→Iso
.

Liquid crystal layer J & object E Cryst, ->Sac”--→ch--→Iso.

In addition, when a ferroelectric liquid crystal element was prepared in exactly the same manner as in Example 3 except that the liquid crystal composition ￥＠E was injected into the cell, the uniform alignment within this liquid crystal element was good, and a monodomain state was observed. was gotten.

[Effects of the Invention] As explained above, an element using a ferroelectric liquid crystal composition containing a liquid crystal compound of the present invention has good switching characteristics, a liquid crystal element with an expanded operating temperature range, and a high-speed response. It is possible to provide a liquid crystal element with a low temperature dependence of response speed.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display device using the ferroelectric liquid crystal layer of the present invention, and FIGS. 2 and 3 show an element cell for explaining the operation of the ferroelectric liquid crystal device. FIG. 2 is a perspective view schematically showing an example of. l... Ferroelectric liquid crystal layer 2... Glass substrate 3...
Transparent electrode 4... Insulating alignment control layer 5... Spacer 6... Lead wire 7... Electron s
8...Polarizing plate 9...Light source ■.・・・
・Incoming light■...Transmitted light 21a...Substrate 21b...Substrate 22...
・Liquid crystal molecule layer 23...Liquid crystal molecule 24...Dipole moment (P) 31a, 31b...Voltage application means 3 cores a...First stable state 33b...Second stability State 34a... L-directed dipole moment 34b... Downward dipole moment Ea... Upward electric field Eb-... Downward 'world'

Claims (3)

[Claims] (1) A liquid crystal compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R^1 is a linear or branched alkyl group that may have a substituent having 1 to 18 carbon atoms, R^2 is an alkyl group having 1 to 12 carbon atoms, X is a single bond, -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. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, Y is a single bond, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -CH_2O-, -OCH_2
−, and A and B are selected from ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ respectively. Indicates what was independently selected. l is 0, 1 or 2
, m is 0, 1 or 2, n is 1 or 2, and 2
+m+n is 2 or 3. C^* indicates an asymmetric carbon atom. ) (2) A ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R^1 is a linear or branched alkyl group that may have a substituent having 1 to 18 carbon atoms, R^2 is an alkyl group having 1 to 12 carbon atoms, X is a single bond, -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. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, Y is a single bond, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -CH_2O-, -OCH_2
−, and A and B are selected from ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ respectively. Indicates what was independently selected. l is 0, 1 or 2
, m is 0, 1 or 2, n is 1 or 2, and l
+m+n is 2 or 3. C^* indicates an asymmetric carbon atom. ) (3) A liquid crystal element characterized in that a ferroelectric chiral smectic liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (I) is disposed between a pair of electrode substrates. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R^1 is a linear or branched alkyl group that may have a substituent having 1 to 18 carbon atoms, R^2 is an alkyl group having 1 to 12 carbon atoms, X is a single bond, -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. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, Y is a single bond, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -CH_2O-, -OCH_2
−, and A and B are selected from ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ respectively. Indicates what was independently selected. l is 0, 1 or 2
, m is 0, 1 or 2, n is 1 or 2, and 2
+m+n is 2 or 3. C^* indicates an asymmetric carbon atom. )