JPS61228420A - Liquid crystal element - Google Patents

Abstract

PURPOSE:To enable to form a smectic phase which does not generate an orientation defect, especially to form the ferroelectricity liquid crystal phase which has a nonspiral structure, and does not generate the orientation defect by using a specific liquid crystal to the titled element. CONSTITUTION:The titled element is formed by forming a cell structure which encloses a liquid crystal shown by formula I or a composition contg. the liquid crystal between a pair of substrates, and the smectic phase is formed from the phase lying in the high temp. side by phase-transformation. The titled element has an effect of dominantly orientating the direction of a molecular axis of the liquid crystal in which the surface of at least one of the substrate of a pair of the substrates contacts at an interface, to one direction. The liquid crystal has the ferroelectricity and concretely the chiral smectic C phase SmC* may be used. The compounding amount of the compd. shown by formula I is preferably 1-99wt%, further preferably 5-95wt%.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid crystal element applied to a liquid crystal display element, a liquid crystal-light shutter array, etc., and more specifically, the present invention relates to a liquid crystal element applied to a liquid crystal display element, a liquid crystal-light shutter array, etc. This invention relates to a liquid crystal element with improved driving characteristics.

[Prior Art] As a conventional liquid crystal element, for example, M-Shut (M,
5chadt) and W. Helfrich (W,
He1fricb) “Applied” 74 Physics Letters (Applied Physics Letters)
Vol. 18, No. 4 (February 15, 1971), pp. 127-128, “Voltage Dependent Optical Activity of a Twisted Nematic Liquid Crystal”
(Voltage Dependent 0ptic
alActivit7 of a Twist
d Mega eyes c Liquid Crystal”
) shown in the twisted nematic
d nematic ) using liquid crystals are known. The number of pixels in this 7N liquid crystal was limited because of the problem of crosstalk occurring during time-divided driving using a matrix electrode structure with high pixel density.

Further, a display element is known in which a switching element using a thin film transistor is connected to each pixel and each pixel is switched, but the process of forming the thin film transistor on the substrate is extremely complicated.

There is a problem in that it is difficult to create a display element with a large area.

Clark (Gl.
ark) and Lagerwall ()
(Japanese Unexamined Patent Publication No. 58-1072113, U.S. Patent No. 4,387,924, etc.), liquid crystals having bistability are generally composed of chiral smectic C phase (Sac or H phase (SmH)). A ferroelectric liquid crystal is used which has a bistable state including a first optically stable state and a second optically stable state with respect to an electric field.

Therefore, unlike the optical modulation element used in the above-mentioned TN type liquid crystal, the liquid crystal is oriented in a first optically stable state for one electric field vector, and a second optically stable state for the other electric field vector. The liquid crystal is aligned in an optically stable state. Furthermore, this type of liquid crystal has the property of very quickly 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.

By utilizing such properties, considerable improvements can be obtained in many of the problems of the conventional TN type elements mentioned above. This point is related to the present invention as follows:
This will be explained in more detail. However, in order for this ferroelectric liquid crystal with bistability to exhibit predetermined driving characteristics, the liquid crystal placed between a pair of parallel substrates must be in the above two stable states, regardless of the applied state of the electric field. It is necessary that the molecules be arranged in such a state that conversion between them can occur effectively. For example, Sac book, 5ai1”, SmJ”, SmK
For ferroelectric liquid crystals having Sm (i', Sd" or SmH" phases), the liquid crystal molecular layer having the 5taC, etc. is perpendicular to the substrate surface, and therefore the liquid crystal molecular axis is aligned with the substrate surface. Regions arranged almost parallel to each other (monodomains)
needs to be formed.

However, in conventional bistable and constant ferroelectric liquid crystal elements, the alignment state of the liquid crystal having such a domain structure was not necessarily formed satisfactorily.
The reality is that sufficient characteristics were not obtained.

For example, according to Glark et.
Several methods have been proposed for arranging the . however,
None of these methods necessarily produced satisfactory results. For example, the method of applying a magnetic field requires large-scale equipment and is incompatible with thin-layer cells with good operating characteristics. This method has the disadvantage that it is incompatible with the method of injecting liquid crystal. Further, the method of arranging parallel edges within a cell cannot provide a stable alignment effect by itself.

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, an object of the present invention is to solve the problem as a display element having high-speed response, high-density pixels, and a large area, or an optical shutter having a high shutter speed. The purpose of the present invention is to provide a ferroelectric liquid crystal element that can fully exhibit its characteristics by improving monodomain formation or initial orientation, which has been a problem in the past. .

[Function] As a result of research in line with the above-mentioned purpose, the present inventors sandwiched a specific liquid crystal or a composition containing the liquid crystal between substrates to which a uniaxial alignment treatment effect was applied, and the liquid crystal was placed on a higher temperature side than the smectic phase. Phases of, for example, Coleste.

When a phase transition is caused by slow cooling from a lick phase (chiral nematic phase), a nematic phase, or a tokiyoshi phase, for example, when forming S-A or chiral smectic phase, a monodomain in which liquid crystal molecules are aligned in one direction is formed. We have discovered that as a result, we can obtain a liquid crystal element with a structure that allows both the operation of the element based on the bistability of the ferroelectric liquid crystal and the monodomain nature of the liquid crystal layer.

[Means for solving the problems] The liquid crystal element of the present invention is based on the above-mentioned findings,
More specifically, a cell structure is formed in which a liquid crystal compound represented by the following general formula (I) or a liquid crystal composition containing a compound represented by the following general formula (I) is sealed between a pair of substrates, and the liquid crystal A smectic phase of the compound or composition is formed by phase transition from a phase on the higher temperature side than the smectic phase, and the smectic phase is formed in one direction with priority given to the molecular axis direction where the surfaces of at least one of the pair of substrates touch at the interface. It is characterized in that it has the effect of arranging it.

General formula (I) (In the above general formula, R is an alkyl group or an alkoxy group having 1 to 18 carbon atoms, - is O or 1, -=
When 0, R' is an alkyl group having 1 to 18 carbon atoms, and when -=1, R' is an alkyl group or an alkoxy group having 1 to 18 carbon atoms. Refer to the drawings below as necessary. The present invention will now be described in more detail.

The liquid crystal used in the present invention has ferroelectricity, and specifically has a chiral smectic C phase (S-C phase).
H phase (S layer, I phase (1 s layer, J phase (SmJ layer, K phase)
A liquid crystal having a phase (S), a G phase (SmG), or an F phase (SmF) can be used.

Specific examples and synthesis methods of the compound represented by the general formula (1) are as follows.

The compound of the present invention represented by the general formula (I) is, for example, a 2,3-dicyano compound represented by the general formula (■): (wherein R is an alkyl group or an alkoxy group having 1 to 18 carbon atoms) After hydrolyzing the pyrazine derivative, it is decarboxylated to obtain a 2-carboxypyrazine derivative represented by the general formula (■): This is halogenated to form an acid halide, and this is converted into an acid halide by the general formula (■): (in the formula The intestine is O or l, and when ■ = 0, R' is an alkyl group having 1 to 18 carbon atoms, and when 1 = 1, R' is an alkyl group or an alkoxy group having 1 to 18 carbon atoms. It can be produced by reacting and esterifying the compound shown below.

The 2,3-dicyanopyrazine derivative represented by the general formula (II) can be produced by a known production method [Tadataka Tsuda et al.
Journal of the Japanese Society of Agricultural Chemistry, Vol. 52, p. 213 (1978)]
This can be obtained by using .

A ferroelectric liquid crystal can be easily obtained by introducing an optically active group into the structure represented by the general formula (I). The ferroelectric chiral smectic liquid crystal represented by the general formula (I) has excellent threshold characteristics for electric field response when used as a display element as shown by N., A., and Glark et al. When a smectic liquid crystal is used in a display driven by simple matrix electrodes, crosstalk can be prevented and good contrast can be provided. These characteristics also apply to liquid crystal compositions containing liquid crystal compounds represented by the general formula (I), and when using ferroelectric smectic liquid crystals as high-definition, large-screen display elements, the general formula ( The liquid crystal compound represented by I) is particularly excellent.

On the other hand, for compounds of general formula (I) that do not contain optically active groups in their structure and have a Sac phase (for example, p-octyloxyphenyl 5-(P-octyloxyphenyl) pyrazine-2-carboxylate), A liquid crystal composition obtained by mixing liquid crystal compounds having a chiral smectic phase as shown in Table 3 can be used as a ferroelectric chiral smectic liquid crystal. Instead of mixing a liquid crystal compound having a chiral smectic phase, a liquid crystal composition containing a liquid crystal compound containing an optically active group but not exhibiting a chiral smectic phase as shown in Table 4 or simply containing a liquid crystal compound containing an optically active group. Materials can also be used as ferroelectric chiral smectic liquid crystals.

The ferroelectric smectic liquid crystal compositions thus prepared exhibited excellent dark value properties conferred by the basic framework presented in the present invention.

The content of the compound represented by general formula (I) in the liquid crystal composition used in the present invention is preferably 1% to 88% by weight, more preferably 5% to 85% by weight.

Next, a synthesis example of the compound represented by the general formula (I) will be shown.

Synthesis Example 1 5-(p-octyloxyphenyl)pyrazine-2-carboxylic acid p-octyloxyphenyl ester dioxide-
1! L/711.4g (0.1 amount oN), dioxane ioo 9 and water 2119 were mixed, 70~75
After stirring for 2 hours at <0>C, a solution of 24.8 g (0.1 weight oN) p-octyloxyacetophenone-dioxane (80 weight) was added. After refluxing for 2 hours, the mixture was cooled and precipitated metallic selenium was filtered. Add 1 diaminomaleonitrile to the filtrate.
0.8g (0.1 amount oN), acetic acid 3. Add hN, 9
It was refluxed at 0-93°C for 2 hours. After the reaction was cooled and filtered, the filtrate was concentrated to obtain a crude product. After recrystallization from hexane, 27.2 g (82% yield) of product was obtained. Melting point: 78°C.

IRpcta-': 2245 (C=N).

Elemental analysis C2o H22N4 Calculated value as Q: C
71,83H8,83N 18.75 Actual value: C72
,02H6,75N 16.555-(p-octyloxyphenyl)pyrazine-2,3-dicarbonitrile (
8.7g, 0.028mol12) of sodium hydroxide (15g, 0.375mof water (800mJ2)
After the reaction was stirred at 95° C. for 3 hours, the reaction solution was made acidic by adding concentrated hydrochloric acid, and the precipitate was filtered.

After washing 5 times with 80ml of water and vacuum drying, 8.1g (
A product with a yield of 84% was obtained. After recrystallization from ethanol-water, melting point 183°C, IRy cm-1: 3400
~2550 (OH), 1730.1895 (C-0)
.

Elemental analysis Calculated value as GzoH2nN205: C8
4,50Hf3.50N 7.52 Actual value: C84
,52H6,70N 7.385-(p-octyloxyphenyl)pyrazine-2,3-γ゛carboxylic acid 8.
1 g, 0.0218 m0J2) in dichlorobenzene (100 mN), set the oil bath to 160°C, and heated.
．． Stirred for 5 hours. - After standing overnight, the precipitate was filtered and washed 2 times with 80 mfi of hexane to obtain 4.1 g of product. After recrystallization from ethanol-water, melting point is 185°C, decomposition point is 1! i0℃, IRy cm-l: 3400-25
00 (OH), 1680 (C=0).

Elemental analysis Calculated value as C1qH2aN203: C
H,49H7,37N 8.53 Actual value: C89,E
t5 H7,35N 8.38 (IT) Esterification 5-(p-octyloxyphenyl)pyrazine-2-carvone @ (4,10 g, 0.0125 moN) was placed in 80 IILl of thionyl chloride and refluxed for 2 hours. Thereafter, excess thionyl chloride was distilled off under reduced pressure, and the residue was dissolved in 250 ml of toluene. Add toluene solution to 70 ml of water
The solution was washed four times with 2 and dried over magnesium sulfate, and then the solvent was distilled off. The residue was washed with hexane and acetone (10
P-octyloxyphenol 1.77g (7,913m
moR), sodium hydroxide 0.38g (9 layers oR)
, a mixed solution of 10 ml of water and 20 mjl of acetone.
It was added dropwise over 5 minutes. Then, after stirring at 5°C for 2 hours, the reaction solution was filtered. The precipitate was dissolved in toluene (400 m
N ) and 0.5N aqueous sodium hydroxide solution 1
The toluene solution was washed with 50 mN and further washed three times with 200 mjl of water, and then dried over magnesium sulfate, and then the solvent was distilled off. The residue was washed with hexane and toluene-
After recrystallization from hexane, 1.98 g (29% yield) of product was obtained.

IRy cm-1: 1730 (C-0).

Elemental analysis Calculated value as 033 Ha 4 N20s: C74,40H8°33N5.213 Actual value: C
74,55H8,51N S-09MMRδ ppm (
CDCIx): 9.4G (d, IH, J-1, 5H
z), 9.15 (d, LH, J=1.5Hz),
8.11(d, 2H).

7.08 (d, 2) 1), 7.18 (d, 2H),
8.90 (d, 2H), 4.04 (t, 2H), 3
．． H(t.

2H), 1.130-0.70 (mouth, 30H).

Synthesis examples 2 to 18 In the same manner as in Example 1, the compounds shown in Table 1 were obtained.

Table 2 shows the results of elemental analysis of the compound obtained in Synthesis Example 1-19, and Table 3 shows the phase transition temperature.

Table 3 48″G 58°0 94°G crystal = #S■
Cψ=SIIA==Isotropic phase-COOCH2CHC2H5 ;11; 171.0@CI74.2@C ←-1-Cholesteric phase←-= IsoA phase 88.8@0
80.2°C183,56C crystal==SmC6=Cholesteric phase;=Co-isotropic phase76°C88,1ll”C
155,46C crystal; = SIC umbrella = cholesteric phase □
Isotropic phase 112°C131°C □Cholesteric phase === Isotropic phase table 4 (A) Cholesteryl propionate CB) Cholesteryl nonanate (C) Cholesteryl palmitate? ? "C83@C Crystal; = Nicolesteric phase = = Isotropic phase (D) Cholesteryl nonanate 4-(2'-methylbutyl)-4'-cyanobiphenyl-cyanobiphenyl-(2-methylbutyl)aniline-hexyloxy Azobenzene When an element is constructed using these materials, the liquid crystal compound is Sac'', S+sl'', SsJ'', SmK skewer, S
+sGe, SmF" or SmH" phase.

If necessary, the element can be supported by a copper block or the like in which a heater is embedded.

FIG. 1 schematically depicts an example of a cell for explaining the operation of a ferroelectric liquid crystal. 21a and.

21b is l11203, 5n02 or ITO (
A substrate (glass plate) coated with a transparent electrode made of a thin film such as Indium-TinOxide (Indium-TinOxide), etc., between which a 5raC" phase or 5s)I" phase liquid crystal is oriented such that a liquid crystal molecular layer 22 is perpendicular to the glass surface. is included. 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 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 all the dipole moments (P) 24 are 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, 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 is a liquid crystal optical modulation element whose optical characteristics change.

The liquid crystal cell preferably used in the liquid crystal element of the present invention can be made sufficiently thin (for example, 10 g or less).As the liquid crystal layer becomes thinner, the electric field can be reduced as shown in FIG. Even when no voltage is applied, the helical structure of the liquid crystal molecules unwinds and assumes a non-helical structure, and its dipole moment (Pa or pb) is either upward (34a) or downward (34b). When an electric field Ea or Eb of different polarity above a certain threshold value is applied to such a cell by the voltage applying means 31a and 31b as shown in FIG. 2, the dipole moment corresponds to the electric field vector of the electric field Ea or Eb. Then, the liquid crystal molecules are oriented in either the first stable state 33a or the second stable state 33b. As mentioned earlier, 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. 2, for example, when the electric field Ea is applied, the liquid crystal molecules are oriented in the first stable state 33a, and this state remains stable even when the electric field is turned off. When an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to a second stable state 33b and change their orientation, but they remain in this state even after the electric field is turned off. Further, as long as the applied electric field Ea does not exceed a certain darkness value, each orientation state is maintained. In order to effectively realize such fast response speed and bistability, it is preferable that the cell be as thin as possible.

As mentioned earlier, the biggest problem in forming devices using liquid crystals with such ferroelectricity is Sq
C., SsI”, SmJ”%SmK”, SmG”, S
It is difficult to form a highly monodomain cell in which the layer having the mF" or SmH phase is aligned perpendicular to the substrate surface and the liquid crystal molecules are aligned approximately parallel to the substrate surface. It is the main objective of the present invention to provide a solution to this point.

FIGS. 3(A) and 3(B) show an embodiment of the liquid crystal element of the present invention. FIG. 3(A) is a plan view of the liquid crystal element of the present invention, and FIG. 3(B) is a cross-sectional view taken along the line AA'.

In the cell structure 100 shown in FIG. 3, a pair of substrates 101a and 101b made of glass plates or plastic plates are held at a predetermined distance by spacers 104, and are bonded with an adhesive 108 to seal the pair of substrates. Further, on the substrate 101, an electrode group (for example, an electrode group for applying a scanning voltage in a matrix electrode structure) consisting of a plurality of transparent electrodes 102 is arranged in a predetermined pattern such as a strip pattern. It is formed. Substrate 101
An electrode group (for example, a signal voltage application electrode group in a matrix electrode structure) is formed on the transparent electrode 102a and the plurality of transparent electrodes 102b intersecting with the transparent electrode 102a.

The substrate 101b provided with such a transparent electrode 102b has
For example - silicon oxide, silicon dioxide, aluminum oxide,
Inorganic insulating materials such as zirconia, magnesium fluoride, cellulum oxide, cerium fluoride, silicon nitride, silicon carbide, boron nitride, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylylene, polyester, polycarbonate, polyvinyl The alignment control film 105 may be formed using an organic insulating material such as acecool, polyvinyl chloride, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, or acrylic resin.

The orientation control film 105 is obtained by forming a film of an inorganic insulating material or an organic insulating material as described above, and then rubbing the surface of the film in one direction with velvet, cloth, or paper.

In another preferred embodiment of the present invention, the alignment control film 105 can be obtained by forming a film of an inorganic insulating material such as SiO or 5i02 on the substrate 101b by oblique vapor deposition.

In the apparatus shown in FIG. 5, a Pel jar 501 is placed on an insulating substrate 503 having a suction port 505, and a vacuum pump (not shown) extending from the suction port 505 evacuates the Pel jar 501. . A crucible 507 made of tungsten or molybdenum is placed inside and at the bottom of the Pel jar 501, and several grams of crystal 508 of SiO, 5i02, MgF2, etc. is placed in the crucible 507. The crucible 507 has two lower arms 5G7a,
50? b, and the arms have conductive wires 509 and 51, respectively.
Connected to 0. A power supply 50B and a switch 504 are connected in series between external conductors 509, 510 of Pelger 501. Substrate 502 is positioned inside Pelger 501 directly above crucible 507 at an angle θ with respect to the vertical axis of Pelger 501 .

When the switch 504 is opened, the Pelger 501 is first brought into a vacuum state of about 101 m Hg pressure, and then the switch 504 is closed and the power supply 506 is turned on until the crucible 507 becomes incandescent at a suitable temperature and the crystal 508 is evaporated. Power is supplied in a regulated manner. The required current for a suitable temperature range (700-1000°C) is about 100 aps. The crystal 508 is then evaporated to form an upward molecular stream indicated by S in the figure.
The fluid S is directed toward the substrate 502 at an angle θ with respect to the substrate 502.
02, and as a result, the substrate 5G2 is covered.

The angle θ is the above-mentioned "incident angle", the direction of the fluid S is the above-mentioned "oblique deposition direction", and the film thickness of this film is the same as that of the substrate 50.
2 into the Pelger 501 by a time-based thickness calibration of the device. When a film of appropriate thickness is formed, the power from the power source 50B is reduced, the switch 504 is opened to cool the Pel jar 501 and its interior, and the pressure is increased to atmospheric pressure to remove the substrate 502 from the Pel jar 501.

In another specific example, after forming a film of the above-mentioned inorganic insulating material or organic insulating material on the surface of the substrate 101b made of glass or plastic or on the substrate 101b, the surface of the film is etched by an oblique etching method. Accordingly, an orientation control effect can be imparted to the surface.

It is preferable that the above-mentioned orientation control gIII 105 also function as an insulating film at the same time, and for this purpose, the film thickness of this orientation control film 105 is generally 100A-1, preferably 5.
It can be set in the range of 00A to 5000A.

This insulating film also has the advantage of being able to prevent the generation of current caused by trace amounts of impurities contained in the liquid crystal layer 103, and therefore does not deteriorate the liquid crystal compound even if the operation is repeated.

Further, in the liquid crystal element of the present invention, a film similar to the above-described alignment control film 105 can be provided on the other substrate 101.

The liquid crystal layer 103 in the cell structure 100 shown in FIG.
Sac umbrella, SmH", SmH fist, SmJ",
It can be SmK-1SmGψ, SmF fist. The liquid crystal layer 103 of the chiral smectic phase is formed by a temperature decreasing process by slow cooling (1° C. to 10° C./hour) from a phase on the higher temperature side than the smectic phase, such as a cholesteric phase (chiral nematic phase), a nematic phase, and an etcetera phase. DeSm
It is formed by phase transition to A (smectic A phase) and then phase transition to chiral smectic phase in the temperature decreasing process by slow cooling, or it is formed by phase transition from cholesteric phase etc. to chiral smectic phase without going through S A. It can be formed by transfer.

An important point in the present invention is that a monodomain smectic phase can be formed when the above-mentioned liquid crystal is used in the temperature decreasing process by slow cooling.

The liquid crystal composition used in the present invention is a composition that undergoes a phase transition between an isotropic phase, a cholesteric phase, SmA, and a chiral smectic phase during a temperature cooling process. It can be done in minutes.

FIG. 4 shows another specific example of the liquid crystal element of the present invention. The liquid crystal element shown in FIG. 4 consists of a pair of substrates 101a and 1
A plurality of spacer members 203 are arranged between 01b. This spacer member 203 is, for example, the alignment control film 10
SiO, 5i0 on the substrate 101a where 5 is provided
2. AUz03. Inorganic compounds such as TiO2, polyvinyl alcohol, polyimide, polyamideimide, polyesterimide, polyparaxylylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, Yulia resin, After forming a film of resin such as acrylic resin or photoresist resin by an appropriate method, spacer member 2 is placed in a predetermined position.
It can be obtained by etching so that 03 is arranged.

Such a cell structure 100 includes substrates 101a and 101b.
Polarizers 107 and 108 in a crossed nicol state or a parallel nicol state are arranged on both sides of the electrodes 102a and 102b, respectively, and optical modulation occurs when a voltage is applied between the electrodes 102a and 102b.

[Example] Hereinafter, the present invention will be explained according to examples.

Example 1 A square glass substrate was prepared on which a striped ITO film with a pitch of 100 gra and a width Ei of 2.5 gm was provided as an electrode, and the side on which the ITO film serving as the electrode was placed faced downward. Set it in the oblique evaporation device shown in Figure 5,
Next, 5i02 crystals were set in a molybdenum crucible. After that, the inside of the vapor deposition apparatus is made into a vacuum state of about 1O-5 Torr, and 5i is deposited on the glass substrate using a predetermined method.
02 was obliquely deposited to form an obliquely deposited film of 800 A (electrode plate A).

On the other hand, a polyimide forming solution (r
PrQJ (non-volatile content concentration 14.5 wt%) was applied using a spinner coater, heated at 120°C for 30 minutes, and then
80 minutes at 350 degrees Celsius, then heated for 30 minutes at 350 degrees Celsius.
A coating of 00A was formed (B electrode plate).

Next, a thermosetting epoxy adhesive is applied to the periphery of the A electrode plate except for the area that will become the injection port using a screen printing method, and then the striped pattern electrodes of the A electrode plate and the B electrode plate are overlapped so that they are perpendicular to each other. The distance between the two electrode plates was maintained at 2JL using a polyimide spacer.

The above-mentioned 2 which is in Tokichi phase in the cell created in this way
-Methylbutylo,xyphenyl-5-(octyloxyphenyl)pyrazine-2-carbonate was injected through the injection port, and the injection port was sealed. When this cell was cooled slowly and maintained at 125°C, a pair of polarizers were installed in a crossed nicol state, and microscopic observation revealed that it had a non-helical structure and was a monodomain with no orientation defects. 5taC'' was found to be formed.

or.

When the electric field response was measured at 125°C, a response of 1 W116C or less was obtained at 50V. It was also found that it had excellent threshold characteristics since it did not reverse even when a 40 V DC electric field was applied for 10 m5 ec or more.

Example 2 Two square glass substrates were prepared with striped 1-0 electrodes with a pitch of too IL■ and a width of 62.5 mm, and a polyimide forming solution (same as in Example 1) was prepared on each substrate. ) with a spinner coater, 120
After heating at ℃ for 30 minutes, heat at 200℃ for 60 minutes for 3 more minutes.
Heating was performed at 50°C for 30 minutes to form a polyimide film of 800A.

on the polyimide film formed on these two substrates.

The rubbing process with velvet was performed so that when stacked, the rubbing directions were parallel and the striped ITO electrodes were perpendicular to each other.

Next, the two substrates were stacked so that the rubbing directions were parallel to each other, and a thermosetting epoxy adhesive was applied to the periphery of one substrate by screen printing except for the area that would become the injection port. The two substrates were stacked on top of each other, and the distance between the two substrates was maintained at a 2p layer using a polyimide spacer.

The liquid crystal composition A shown below (which exhibited Sac'' at 20°C to 78°C) was injected into the thus prepared cell through the injection port, and the cell was sealed by slow cooling. After lowering the temperature and maintaining the temperature at 40°C, a pair of polarizers was placed in a crossed nicol state, and microscopic observation revealed that it had a non-helical structure with no orientation defects, and a monodomain S-G association. It was found that it was formed.

Liquid AJLIL Disaster A 24, Owt$ 80.8wt1 Also, when I checked the electric field response, it was 1 rasec at 20V.
Good contrast was obtained.

Example 3 When the pyrazine compound of the present invention, which does not have an optically active group in its structure but exhibits a 5llC phase, and a liquid crystal compound which exhibits only a cholesteric phase were mixed in the composition shown below (liquid crystal composition B), the composition was 112 to 171'. He showed good luck with 5IIC in O.

A ferroelectric liquid crystal element was produced in the same manner as in Example 2, except that this liquid crystal composition B was replaced with composition A used in Example 2.

Liquid crystal composition B 8.2wtX 91.8wt$ When this ferroelectric liquid crystal element was observed with a polarizing microscope,
A non-helical monodomain with no orientation defects was confirmed.

Also, when I checked the response at 184℃, IOV
The response speed was fast at less than ec, and good contrast was obtained.

Example 4 The same procedure as Example 2 was used, except that in place of the liquid crystal composition A used when creating the liquid crystal element of Example 2, the following liquid crystal composition C, which becomes Sac'' at 10°C to 55°C, was used. A ferroelectric liquid crystal device was created using a similar method.

10, Owt$ 72, Owt$ 18, Owt$ When this ferroelectric liquid crystal element was observed with a polarizing microscope,
A non-helical monodomain with no orientation defects was confirmed.

Further, when the electric field response of this ferroelectric liquid crystal element was examined, it was found that the response was as fast as 1 sec or less at 20 V, and the contrast was also good.

[Effects of the Invention] As described above, according to the present invention, by using the above-mentioned specific liquid crystal, it is possible to form a smectic phase with no alignment defects, and in particular, it is possible to form a smectic phase with no alignment defects. A dielectric liquid crystal phase can be formed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing a liquid crystal element using chiral smectic liquid crystal. FIG. 2 is a perspective view schematically showing the bistability of the liquid crystal element. Figure 3 (A)
is a plan view showing the liquid crystal element of the present invention, and FIG. 3(B)
is a sectional view taken along line A-A'. FIG. 4 is a sectional view showing another specific example of the liquid crystal element of the present invention. Figure 5 shows
FIG. 1 is a cross-sectional view schematically showing an oblique evaporation apparatus used when producing a liquid crystal element of the present invention.

Claims (3)

[Claims] (1) A cell structure is formed in which a liquid crystal compound represented by the following general formula (I) or a liquid crystal composition containing a compound represented by the following general formula (I) is sealed between a pair of substrates, and the liquid crystal compound or composition is sealed between a pair of substrates. A smectic phase of the substance is formed by phase transition from a phase on a higher temperature side than the smectic phase, and the molecular axes of the surfaces of at least one of the pair of substrates are arranged in one direction with priority given to the direction of the molecular axis in contact with the interface. A liquid crystal element characterized by having an effect. General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the above general formula, R is an alkyl group or alkoxy group having 1 to 18 carbon atoms, m is 0 or 1, and m=
When 0, R' is an alkyl group having 1 to 18 carbon atoms, and when m=1, R' is an alkyl group or an alkoxy group having 1 to 18 carbon atoms.) (2) The liquid crystal element according to claim 1, wherein R' in general formula (I) is an optically active 2-methylbutyl group. (3) The liquid crystal element according to claim 1, wherein R' in general formula (I) is an optically active 2-methylptoxy group.