JP2000191657A - Thiophene compound, liquid crystal composition containing the same, liquid crystal device having the composition, and display device and method of display using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound capable of giving a liquid crystal composition good in switching characteristics and having excellent properties including quick responsiveness, diminished temperature dependency of optical speed of response and high contrast. SOLUTION: This new thiophene compound is a compound of the formula R1-A1-A2-B1-A3-B2-A4-R2 [R1 and R2 are each a 1-20C alkyl; A1 and, A2 are each a (substituted) 1,4-phenylene, pyridine-2,5-diyl, or the like; A3 and A4 are each a (substituted) 1,4-phenylene, pyrimidine-2,5-diyl, or the like; B1 and B2 are each a single bond, COO, OOC, or the like], e.g. 6-[4-(5-octylthiophen-2-yl) benzenecarbonyloxy]-1,2,3,4-tetrahydro-2-naphthalenecarboxylic acid (R)-1,1,1- trifluoro-2-hexyl ester of formula I. The aimed compound is obtained, in the case of the compound of formula I, by reducing and then esterifying a compound of formula II to form a compound of formula III which is then reacted with benzyl bromide, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thiophene compound, a liquid crystal composition containing the same, a liquid crystal element and a liquid crystal device using the same, and a liquid crystal element used for a liquid crystal display element or a liquid crystal-optical shutter. And a display device using the liquid crystal element for display.

[0002]

2. Description of the Related Art Conventionally, liquid crystals have been applied in various fields as electro-optical elements. Most liquid crystal elements currently in practical use are, for example, M. Sch (M. Sch.
adt) and W. Helfrich
ch), “Applied Physics Letters”
("Applied Physics Letter
s ") Vol. 18, No. 4 (1971.2.15)
P. 127-128 "Voltage Depend
ent Optical Activity of a
Twisted Nematic Liquid Cr
ystal ”, the TN (Twisted Nem
(atic) type liquid crystal.

[0003] These are based on the dielectric alignment effect of liquid crystal, and use the effect that the average molecular axis direction is directed to a specific direction by an applied electric field due to the dielectric anisotropy of liquid crystal molecules. The limit on the optical response speed of these devices is said to be milliseconds, which is too slow for many applications.

On the other hand, in application to a large flat display, driving by a simple matrix system is the most influential in consideration of price, productivity and the like. In the simple matrix system, an electrode configuration in which a scanning electrode group and a signal electrode group are configured in a matrix is employed. To drive the scanning electrode group, an address signal is sequentially and selectively applied to the scanning electrode group, and the signal electrode group is applied. Adopts a time-division driving method in which a predetermined information signal is selectively applied in parallel in synchronization with an address signal.

However, when the above-mentioned TN type liquid crystal is adopted as the element of such a driving system, the scanning electrode is selected and the signal electrode is not selected, or the scanning 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 threshold required for aligning the liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage value, The display element works normally,
When the number of scanning lines (N) is increased, the entire screen (1
The time (duty ratio) during which an effective electric field is applied to one selected point while scanning a frame (frame) is reduced at a rate of 1 / N.

For this reason, the voltage difference as an effective value between the selected point and the non-selected point when the repetitive scanning is performed is as follows.
As the number of scanning lines increases, the number of scanning lines decreases, and as a result, the image contrast is reduced and crosstalk is inevitable.

Such a phenomenon is caused by a liquid crystal having no bistability (a stable state in which liquid crystal molecules are horizontally aligned with respect to an electrode surface, and a vertical state only while an electric field is effectively applied. This is essentially an unavoidable problem that occurs when driving (ie, repeating scanning) using the time accumulation effect.

In order to improve this point, a voltage averaging method,
The frequency driving method and the multiplex matrix method have already been proposed, but none of these methods is sufficient, and the increase in the screen size and the density of the display element has ceased because the number of scanning lines cannot be sufficiently increased. That is the current situation.

[0010] As an improvement over the disadvantages of the conventional liquid crystal device, the use of a liquid crystal device having bistability has been improved by Clark and Lagerwell.
11) (JP-A-56-10721).
No. 6, US Pat. No. 4,367,924, etc.). As the bistable liquid crystal, a ferroelectric liquid crystal having a chiral smectic C phase (SmC ^* phase) or an 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 with respect to an electric field. Therefore, the optical modulation used in the above-mentioned TN-type liquid crystal. Unlike the element, 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. In addition, this type of liquid crystal has a property (bistability) that takes one of the above two stable states in response to an applied electric field and maintains the state when no electric field is applied.

In addition to the characteristic having bistability as described above, the ferroelectric liquid crystal has an excellent characteristic of high-speed response. This is because the spontaneous polarization of the ferroelectric liquid crystal and the applied electric field act directly to induce a transition of the alignment state.
It is 3 to 4 orders of magnitude faster than the response speed due to the effects of dielectric anisotropy and electric field.

As described above, the ferroelectric liquid crystal potentially has extremely excellent characteristics, and by utilizing such characteristics, many of the problems of the conventional TN-type device described above can be solved. A fairly substantial improvement is obtained. In particular, application to high-speed optical shutters and high-density, large-screen displays is expected. For this reason, liquid crystal materials with ferroelectricity have been widely studied, but the ferroelectric liquid crystal materials developed up to now have sufficient characteristics for use in liquid crystal devices, including low-temperature operation characteristics, high-speed response, and contrast. It is hard to say that it has such characteristics.

The following equation [1] is provided between the response time τ and the magnitude Ps of the spontaneous polarization and the viscosity η.

[0015]

(Equation 1) (Where E is the applied electric field).

Therefore, to increase the response speed, there are (a) increasing the magnitude Ps of spontaneous polarization, (a) decreasing the viscosity η, and (c) increasing the applied electric field E.

However, the applied electric field has an upper limit since it is driven by an IC or the like. Therefore, it is actually necessary to reduce the viscosity η or increase the value of the magnitude Ps of the spontaneous polarization.

In general, in a ferroelectric chiral smectic liquid crystal compound having a large spontaneous polarization, the internal electric field of the cell caused by the spontaneous polarization tends to be large, and there is a tendency that restrictions on a device configuration which can take a bistable state tend to increase. Further, even if the spontaneous polarization is increased unnecessarily, the viscosity tends to increase with the spontaneous polarization, and as a result, the response speed may not be so high.

If the operating temperature range of an actual display is, for example, about 5 to 40 ° C., the change in response speed is generally about 20 times, which exceeds the limit of adjustment by drive voltage and frequency. It is the current situation.

In general, in the case of a liquid crystal element utilizing birefringence of liquid crystal, the transmittance under crossed Nicols is expressed by the following equation [2].

[0021]

(Equation 2)

In the equation (2), I ₀ is the incident light intensity, I is the transmitted light intensity, θ _a is the apparent tilt angle defined below, Δ
n is the refractive index anisotropy, d is the thickness of the liquid crystal layer, and λ is the wavelength of the incident light.

The tilt angle θ _a in the aforementioned non-helical structure
Appears as an angle in the average molecular axis direction of the twisted liquid crystal molecules in the first and second alignment states.
According to [2] wherein the tilt angle theta _a the apparent 22.5 °
, The transmittance becomes maximum, and the tilt angle θ _a in the non-helical structure for achieving bistability needs to be as close to 22.5 ° as possible.

Recently, a chiral smectic antiferroelectric liquid crystal device having three stable states has been proposed by Chandani, Takezoe et al. (Japanese Journal of Applied Physics (Japanese)).
se Journal of Applied Physi
cs) Volume 27, 1988, L729). Recently, among these antiferroelectric liquid crystal materials, a V-shaped response characteristic having small hysteresis and advantageous for gradation display has been discovered (for example, Japanese Journal of Applied Physics (Japanese Jones)).
urna1 of Applied Physics)
36, 1997, p. 3586). It has been proposed to use this as an active matrix type liquid crystal element to realize a high-speed display (Japanese Patent Laid-Open No. 9-5 / 1997).
No. 0049).

However, in such a chiral smectic liquid crystal element, for example, “Structure and Physical Properties of Ferroelectric Liquid Crystal” (Corona, Atsuo Fukuda, Hideo Takezoe, 199)
0)), there is a problem that zigzag or streak-like alignment defects are generated and the contrast is remarkably reduced, and some liquid crystal elements are considerably improved. The improvement technique is not almighty, and improvement of the orientation of the chiral smectic liquid crystal is strongly demanded.

[0026]

However, when applied to a ferroelectric liquid crystal having a non-helical structure and exhibiting bistability disclosed by Clark and Ragawall, the following problems are encountered. This causes a decrease in contrast.

First, the apparent tilt angle θ _{a of} the non-helical ferroelectric liquid crystal obtained by orienting with a conventional rubbed polyimide film (the angle between the two axes of the two stable state molecular axes). / 2) is smaller than the tilt angle of the ferroelectric liquid crystal (the angle θ of １ ／ the apex angle of the triangular pyramid shown in FIG. 4 described later), so that the transmittance is low.

Second, even though the contrast is high in the static state where no electric field is applied, when driving display is performed by applying a voltage, the liquid crystal molecules fluctuate due to a small electric field in a non-selection period in matrix driving, so that black appears. It becomes pale.

As described above, in order to put a ferroelectric liquid crystal device into practical use, a liquid crystal composition having a high-speed response, a small temperature dependence of a response speed, and a chiral smectic phase having a high contrast is required. Required. In addition, spontaneous polarization of liquid crystal composition, chiral smectic C pitch, cholesteric pitch, temperature range for taking liquid crystal phase, optics for uniform switching of display, good viewing angle characteristics, low temperature storage property, reduction of load on drive IC, etc. It is necessary to optimize anisotropy, tilt angle, dielectric anisotropy, and the like.

An object of the present invention is to provide a ferroelectric liquid crystal device with practical use in order to provide a large spontaneous polarization, a high-speed response, a reduction in the temperature dependency of a response speed, and an optical effect effective for high contrast. An object of the present invention is to provide an active compound, a liquid crystal composition containing the same, particularly a ferroelectric chiral smectic liquid crystal composition, and a liquid crystal element and a display device using the liquid crystal composition.

Another object of the present invention is to provide a liquid crystal composition having excellent uniform alignment in an antiferroelectric liquid crystal element, a liquid crystal element using the liquid crystal composition, and a display device.

[0032]

That is, the first invention of the present invention is a thiophene compound comprising a compound represented by the following general formula (I).

[0033]

Embedded image

Wherein R ₁ and R _{2 each} have 1 to 2 carbon atoms.
And 0 represents a linear or branched alkyl group. Provided that one or two or more —CH ₂
-Is -O-, -S-,-under the condition that no hetero atom is adjacent.
CO—, —CH ＝ CH—, —C≡C—, —C * HF—,
—C * H (CF ₃ ) —. *
Is an asymmetric carbon.

A ₁ and A ₂ are each independently unsubstituted or 1,4-phenylene and pyridine-2,5 each having one or two substituents selected from F, Cl, Br, CH ₃ and CF _3. -Diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene, 1,3,2-dioxaborinane-2,5-diyl, 1, 3-dioxane-2,
5-diyl, 1,3-dithiane-2,5-diyl, benzoxazole-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6- Diyl, benzofuran-2,5-diyl, benzofuran-2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6-naphthylene, indan-2,5-diyl,
2-alkylindan-2,5-diyl (the alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), coumaran-2,5-diyl, 2-alkylcoumaran-2 , 5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl, thiazole-
It is selected from 2,5-diyl and thiadiazole-2,5-diyl.

A ₃ and A ₄ are each independently a single bond or unsubstituted or one or two F, Cl, Br,
1,4- having a substituent selected from CH ₃ and CF ₃
Phenylene, pyridine-2,5-diyl, pyrimidine-
2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene, 1,
3,2-dioxaborinane-2,5-diyl, 1,3-
Dioxane-2,5-diyl, 1,3-dithiane-2,
5-diyl, benzoxazol-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6-diyl, benzofuran-2,5-diyl, benzofuran
2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6-naphthylene, indane-2,5- Diyl, 2-alkylindane-2,5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), and coumaran-2,5-
Diyl, 2-alkylcoumaran-2,5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl,
Thiazole-2,5-diyl, thiadiazole-2,5
-Selected from diyls. However, at least one of A ₁ and A ₂ is thiophene-2,5-diyl, and at least one of A ₃ and A ₄ is 1,2,3,4-tetrahydro-
2,6-naphthylene.

B ₁ and B ₂ are a single bond, -COO-, -OOC
_{-, - CH 2 O -,} - OCH 2 -, - CH 2 CH 2 -, - C
H = CH- or -C≡C-. ]

In formula (I), one of A ₃ and A ₄ is preferably a single bond. In the general formula (I), one of A ₃ and A ₄ is a single bond, and _one of A ₁ , A ₂ , A ₃ and A ₄ is unsubstituted or one or two F , Cl, Br, CH ₃ and CF _3, preferably a 1,4-phenylene having a substituent. It is preferable that the compound represented by the general formula (I) is an optically active compound or a non-optically active compound.

The second invention of the present invention is a liquid crystal composition comprising at least one of the above thiophene compounds.

The content of the thiophene compound is 1 to 8
It is preferably 0% by weight. It is preferable that the content of the thiophene compound is 1 to 60% by weight. It is preferable that the content of the thiophene compound is 1 to 40% by weight. It is preferable that the liquid crystal composition does not have a chiral smectic C phase.

A third invention according to the present invention is a liquid crystal device comprising the above liquid crystal composition disposed between a pair of electrode substrates.

It is preferable that an alignment control layer is further provided on the electrode substrate on the side in contact with the liquid crystal composition. It is preferable that the orientation control layer is a rubbed layer. It is preferable that the film is disposed between the pair of electrode substrates at a film thickness in which a helical structure formed by the alignment of liquid crystal molecules is released. It is preferable that a thin film transistor or a non-linear active element is provided on the electrode substrate.

According to a fourth aspect of the present invention, there is provided a display device having the above-mentioned liquid crystal element as a display element.

Further, a display device provided with a liquid crystal element driving circuit is preferable. Further, a display device having a light source is preferable.

A fifth invention of the present invention is a display method characterized in that a display image is obtained by controlling the liquid crystal composition according to image information.

[0046]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a thiophene compound comprising a compound represented by the following general formula (I), a liquid crystal composition containing the thiophene compound, and a liquid crystal composition disposed between a pair of electrode substrates. And a display device and a display method using the same.

[0047]

Embedded image

In the general formula (I), R ₁ and R _{2 each} represent a linear or branched alkyl group having 1 to 20, preferably 4 to 15 carbon atoms. However, one or two or more -CH ₂ in the alkyl group - -O Under the conditions heteroatoms are not adjacent -, - S -, - CO- ,
-CH = CH-, -C≡C-, -C * HF-, -C * H
It may be replaced by (CF ₃ )-. * Is an asymmetric carbon.

A ₁ and A ₂ are each independently unsubstituted or 1,4-phenylene, pyridine-2,5 having one or two substituents selected from F, Cl, Br, CH ₃ and CF _3. -Diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene, 1,3,2-dioxaborinane-2,5-diyl, 1, 3-dioxane-2,
5-diyl, 1,3-dithiane-2,5-diyl, benzoxazole-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6- Diyl, benzofuran-2,5-diyl, benzofuran-2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6-naphthylene, indan-2,5-diyl,
2-alkylindan-2,5-diyl (the alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), coumaran-2,5-diyl, 2-alkylcoumaran-2 , 5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl, thiazole-
It is selected from 2,5-diyl and thiadiazole-2,5-diyl.

A ₃ and A ₄ are each independently a single bond or unsubstituted or one or two F, Cl, Br,
1,4- having a substituent selected from CH ₃ and CF ₃
Phenylene, pyridine-2,5-diyl, pyrimidine-
2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene, 1,
3,2-dioxaborinane-2,5-diyl, 1,3-
Dioxane-2,5-diyl, 1,3-dithiane-2,
5-diyl, benzoxazol-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6-diyl, benzofuran-2,5-diyl, benzofuran
2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6-naphthylene, indane-2,5- Diyl, 2-alkylindane-2,5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), and coumaran-2,5-
Diyl, 2-alkylcoumaran-2,5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl,
Thiazole-2,5-diyl, thiadiazole-2,5
-Selected from diyls. However, at least one of A ₁ and A ₂ is thiophene-2,5-diyl, and at least one of A ₃ and A ₄ is 1,2,3,4-tetrahydro-
2,6-naphthylene.

B ₁ and B ₂ are a single bond, —COO—, —OOC
_{-, - CH 2 O -,} - OCH 2 -, - CH 2 CH 2 -, - C
H = CH- or -C≡C-. ]

Among the thiophene compounds, A ₁ , A ₂ , and A ₁ are preferred from the viewpoint of the temperature range, miscibility, viscosity, and orientation of the liquid crystal phase.
_3, Compound any one is a single bond A ₄ are preferred. Further, any one of A ₁ , A ₂ , A ₃ , and A ₄ is a single bond, and any one of A ₁ , A ₂ , A ₃ , and A ₄ is unsubstituted or one or two Substituents (F, Cl, B
A thiophene compound which is 1,4-phenylene having (r, CH ₃ , CF ₃ ) is more preferable.

The present inventors have studied the thiophene compound represented by the general formula (I). As a result, a ferroelectric chiral smectic liquid crystal composition containing the thiophene compound of the present invention,
Further, they have found that a liquid crystal element using them can be improved in various characteristics such as good alignment, high-speed response, reduction of the temperature dependence of the response speed, and high contrast, and good display characteristics can be obtained.

It has also been found that a liquid crystal device using the antiferroelectric liquid crystal composition containing the thiophene compound of the present invention has excellent uniform alignment.

Next, Tables 1 to 4 show specific structural formulas of the thiophene compound of the present invention. Hereinafter, the abbreviations used in the present invention indicate the following groups.

[0056]

Embedded image

[0057]

Embedded image

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

[Table 4]

[0062]

[Table 5]

[0063]

[Table 6]

The liquid crystal composition of the present invention has the general formula (I)
Can be obtained by mixing at least one of the thiophene compounds represented by the formula (1) and one or more other liquid crystal compounds at an appropriate ratio. The number of other liquid crystal compounds to be used in combination is 1 to 50, preferably 1 to 30, and more preferably 3 to 3.
It is in the range of 0.

As another liquid crystal compound used in the present invention,
Are described in JP-A-2-67253 and JP-A-2-1607.
No. 48, JP-A-3-167159 and JP-A-3-3159
-221588, JP-A-4-89454,
JP-A-4-235950, JP-A-5-18640
No. 1, JP-A-5-201983, JP-A-5-2018
JP 230032, JP-A-5-230033,
JP-A-5-230035, JP-A-5-32012
No. 5, JP-A-5-331107, JP-A-6-331107
65154, JP-A-6-128236,
JP-A-8-337555, JP-A-9-48970
JP, JP-A-9-59624, JP-A-9-409
No. 60, JP-A-9-59636, JP-A-9-59
Compound described in JP-A-59640 and JP-A-4-27
Compounds described in JP-A-2989 (23) to (39)
(III) to (XII), preferred compound (IIIa)
~ (XIId), more preferred compound (IIIaa) ~
(XIIdb). Compound (III)
To (VI), preferred compounds (IIIa) to (VI)
f), more preferred compounds (IIIaa) to (VIf)
R 'in a)₁, R '_TwoAt least one of
Compounds (VII) and (VIII), preferred compounds (V
IIa) to (VIIIb), more preferred compound (VI
IIba), R ′ in (VIIIbb)_Three, R '_Four
And compounds (IX) to (XI)
I), preferred compounds (IXa) to (XIId), further
Preferred compounds (IXba) and (XIIdb)
R '_Five, R '₆At least one of-(CH _Two)_EC_G
F_{2G + 1}(E: 0 to 10, G: 1 to 15 integer)
Compounds can be used as well. In addition, the following general formula
Liquid crystal compounds represented by (XIII) to (XVIII)
Can also be used.

[0066]

Embedded image

Here, R ′ ₇ and R ′ ₈ are a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, and are directly bonded to X ^′ ₆ and X ^′ ₉ in the alkyl group. -CH ₂ -
One or two or more non-adjacent —CH ₂ except groups
-Groups are -O-, -CO-, -OCO-, -COO-,-
CH (CN) -, - C (CN) (CH 3) -, may be replaced by.

Further, R ′ ₇ and R ′ ₈ are preferably the following i)
-Viii).

I) a linear alkyl group having 1 to 15 carbon atoms

[0070]

Embedded image p: 0 to 5, q: 2 to 11 Integer Optically active

[0071]

Embedded image r: 0 to 6, s: 0 or 1, t: 1 to 14 integer Optically active

[0072]

Embedded image w: 1 to 15 integers may be optically active

[0073]

Embedded image A: 0 to 2, B: 1 to 15 Integer Optically active

[0074]

Embedded image C: 0 to 2, D: 1 to 15 Integer Optically active

[0075] _{vii) - (CH 2) E} C G F 2G + 1 E: 0~10, G: 1~15 integer

[0076] viii) -H N, Q, R , T: 0 or _{1 Y '7, Y' 8} , Y '9: H or _{F A' 4: Ph, Np} X '6, X' 9: a single bond , -COO -, - O CO - , - O- X '7, X' 8: single bond, -COO -, - OCO -, - CH 2 O -, - OCH 2 -

As a preferred compound of (XIII), (XIII)
IIIa).

[0078]

Embedded image R ′ ₇ -X ^′ _6- [Py2]-[Ph] -OC
_{O- [Tn] -R '8 (} XIIIa)

As a preferred compound of (XVI), (XV
Ia) and (XVIb).

[0080]

Embedded image _{R '7 - [Tz1] -} [Ph] -X' 9 -R '8 (XVI a) R' 7 - [PhY '7] - [Tz1] - [PhY' 8] -X '9 -R _'8 (XVIb)

As a preferred compound of (XVII), (X
VIIa) and (XVIIb).

[0082]

Embedded image _{R '7 - [Boa2] -} [Ph] -O-R' 8 (XVIIa) R '7 - [Boa2] - [Np] -O-R' 8 (XVIIb)

Preferred compounds of (XVIII) include (XVIIIa) to (XVIIIc).

[0084]

Embedded image _{R '7 - [Btb2] -} [Ph] -R' 8 (XVIIIa) R '7 - [Btb2] - [Ph] -O-R' 8 (XVIIIb) R '7 - [Btb2] - _{[Np] -O-R '8} (XVIIIc)

Preferred compounds of (XVIa) and (XVIb) include (XVIaa) to (XVIbc).

[0086]

Embedded image _{R '7 - [Tz1] -} [Ph] -O-R' 8 (XVIaa) R '7 - [Ph] - [Tz1] - [Ph] -R' 8 (XVIba) R '7 - [Ph] - [Tz1] - [Ph] -O-R '8 (XVIbb) R' 7 - [Ph] - [Tz1] - [Ph] -OCO-R '8 (XVIbc)

Ph, Py2, Tn, Tz1, Cy, Bo
The abbreviations of a2 and Btb2 conform to the above definitions, and the other abbreviations indicate the following groups.

[0088]

Embedded image

When the thiophene compound of the present invention is mixed with one or more of the above-mentioned liquid crystalline compounds or liquid crystal compositions, the ratio of the thiophene compound of the present invention in the liquid crystal composition obtained by mixing is as follows. 1% to 80% by weight, preferably 1% to 60% by weight, more preferably 1% by weight
It is desirable that the content be in the range of 40 to 40% by weight. When two or more thiophene compounds of the present invention are used, the proportion of the mixture of two or more thiophene compounds of the present invention in the liquid crystal composition obtained by mixing is 1% by weight to 80% by weight, preferably It is desirable to be in the range of 1% to 60% by weight, more preferably 1% to 40% by weight.

Further, the liquid crystal layer in the liquid crystal device according to the present invention is obtained by heating the liquid crystal composition prepared as described above to an isotropic liquid temperature in a vacuum and enclosing in a device cell.
It is preferable to gradually cool to form a liquid crystal layer and return to normal pressure.

FIG. 1 is a schematic sectional view showing an example of a liquid crystal device having a liquid crystal layer according to the present invention for explaining the configuration of a simple matrix liquid crystal device.

Referring to FIG. 1, in the liquid crystal element, a liquid crystal layer 1 is disposed between a pair of glass substrates 2 provided with a transparent electrode 3 and an insulating alignment control layer 4, respectively. The power supply 7 is connected between the pair of transparent electrodes 3 via a lead wire 6 so that a voltage can be applied from the power supply 7. The pair of substrates 2 is sandwiched between a pair of crossed Nicol polarizing plates 8, and a light source 9 is disposed outside one of them.

Each of the two glass substrates 2 has In ₂
A transparent electrode 3 made of a thin film such as O ₃ , SnO _2, or ITO (Indium Tin Oxide) is covered. A thin film of a polymer such as polyimide is rubbed thereon with a gauze, an acetate flocking cloth or the like, and an insulating alignment control layer 4 for arranging liquid crystals in the rubbing direction is formed.

Examples of the insulating material include silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen, silicon oxide, and the like.
Form an inorganic insulating layer of boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide, magnesium fluoride, etc., on which polyvinyl alcohol, polyimide, polyamide Orienting organic insulating materials such as imide, polyester imide, polyparaxylene, polyester, polycarbonate, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin and photoresist resin As the control layer, the insulating orientation control layer 4 may be formed as two layers, or may be a single layer of an inorganic insulating orientation control layer or an organic insulating insulating control layer.

If the insulating orientation control layer is inorganic, it can be formed by vapor deposition or the like, and if it is organic, a solution in which an organic insulating material is dissolved or a precursor solution thereof (0.1 to 20 in a solvent).
% By weight, preferably 0.2 to 10% by weight) by a spinner coating method, a dip coating method, a screen printing method, a spray coating method, a roll coating method or the like, and under predetermined curing conditions (for example, under heating). ) Can be formed by curing.

The thickness of the insulating orientation control layer 4 is usually from 10 to
1 μm, preferably 10 ° to 3000 °, more preferably 10 ° to 1000 ° is suitable.

The two glass substrates 2 are kept at an arbitrary interval by a spacer 5. For example, there is a method in which silica beads and alumina beads having a predetermined diameter are sandwiched between two glass substrates as spacers, and the periphery is sealed using a sealing material, for example, an epoxy-based adhesive. Others
A polymer film or glass fiber may be used as the spacer. The ferroelectric liquid crystal, that is, the liquid crystal composition of the present invention as described above is sealed between the two glass substrates.

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

The transparent electrode 3 is connected to an external power supply 7 by a lead wire. A polarizing plate 8 is attached to the outside of the glass substrate 2. The example of FIG. 1 is of a transmission type and includes a light source 9.

FIG. 2 schematically shows an example of a cell for explaining the operation of a ferroelectric liquid crystal element. 21a and 2
1b is In ₂ O ₃ , SnO ₂ or ITO, respectively.
(Indium tin oxide; Indium Ti
a substrate (glass plate) covered with a transparent electrode made of a thin film such as n Oxide), and an SmC ^* phase or Sm between which the liquid crystal molecule layer 22 is oriented so as to be perpendicular to the glass surface.
H ^* phase liquid crystal is enclosed. A bold line 23 represents a liquid crystal molecule, and the liquid crystal molecule 23 has a dipole moment (P⊥) 24 in a direction perpendicular to the molecule. When a voltage equal to or higher than a certain threshold value is applied between the electrodes on the substrates 21a and 21b, the helical structure of the liquid crystal molecules 23 is released, and the dipole moment (P２３) 24 is oriented in the direction of the electric field so that the liquid crystal molecules 23 are oriented 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 major axis direction and the minor axis direction. Therefore, for example, if crossed Nicol polarizers are placed above and below the glass surface, the voltage application polarity It can be easily understood that the liquid crystal optical modulation element whose optical characteristics change depending on the liquid crystal.

The liquid crystal cell preferably used in the optical modulation element of the present invention has a sufficiently small thickness (for example, 1 μm).
0 μm or less). As shown in FIG. 3, as the liquid crystal layer becomes thinner, the helical structure of the liquid crystal molecules is released even when no electric field is applied, and the dipole moment Pa or Pb thereof is directed upward (34a) or downward (34b). Take either of the states. When an electric field Ea or Eb having a different polarity or more than a certain threshold value is applied to such a cell by the voltage applying means 31a and 31b as shown in FIG. 3, the dipole moment corresponds to the electric field vector of the electric field Ea or Eb. The liquid crystal molecules are turned to the upward direction 34a or the downward direction 34b, and accordingly, the liquid crystal molecules are in the first stable state 3
3a or the second stable state 33b.

As described above, there are two advantages of using such a ferroelectric liquid crystal element as an optical modulation element. The first is that the response speed is extremely fast, and the second is that the orientation of the liquid crystal molecules has bistability. The second point will be further described with reference to, for example, FIG.
When a is applied, the liquid crystal molecules are oriented to the first stable state 33a, which is stable even when the electric field is turned off. Further, when an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to the second stable state 33b and change the direction of the molecules, but remain in this state even after the electric field is cut off. As long as the applied electric field Ea or Eb does not exceed a certain threshold value, the respective alignment states are also maintained in the previous state.

FIG. 5 shows an example of the driving waveform used in the present invention. In FIG. 5A, S _S is a selected scanning waveform applied to a selected scanning line, S _N is an unselected scanning waveform not selected, and I _S is selection information applied to a selected data line. waveform (black), I _N represents the non-selection information signal applied to the data line which is not selected (white). In the drawing, (I _S -S _S ) and (I _N -S _S ) are voltage waveforms applied to the pixels on the selected scanning line, and the pixels to which the voltage (I _S -S _S ) is applied are black. take the display state, the pixel voltage (I _N -S _S) is applied takes the display state of white.

FIG. 5B is a driving waveform shown in FIG.
7 is a time-series waveform when the display shown in FIG. 6 is performed. FIG.
In the driving example shown in (1), the minimum application time Δt of the single polarity voltage applied to the pixels on the selected scanning line is the writing phase t ₂
And the time of one line clear t ₁ phase is 2Δ
is set to t.

The values of the parameters V _S , V _I and Δt of the drive waveform shown in FIG. 5 are determined by the switching characteristics of the liquid crystal material used. Here, the bias ratio V _I
/ (V _I + V _S ) = 1/3 is fixed.

It is possible to increase the width of the proper driving voltage by increasing the bias ratio. However, increasing the bias ratio means increasing the amplitude of the information signal, and increasing the flicker in image quality. This leads to a decrease in contrast, which is not preferable. According to our study, the bias ratio is 1/3 ~
About 1/4 was practical.

The driving waveform shown in FIG. 9 can also be used.

As a second example of the liquid crystal element of the present invention, there is an active matrix element shown in FIG. FIG. 11 is a plan view showing the configuration of the lower substrate of the liquid crystal element shown in FIG. A transparent pixel electrode 43 and an active element 44 connected to the pixel electrode 43 are formed in a matrix on the lower substrate 41 of the pair of transparent substrates (eg, glass substrates) 41 and 42. The active element 44 is composed of, for example, a thin film transistor called a TFT. In this example, the active element 44 is TF
Represents T. The active element 44 includes a gate electrode formed on the transparent substrate 41, a gate insulating film covering the gate electrode, a semiconductor layer formed on the gate insulating film, and a source electrode and a drain electrode formed on the semiconductor layer. Be composed.

Further, on the lower substrate 41, a gate line (scanning line) 45 is arranged between the rows of the pixel electrodes 43 as shown in FIG. 11, and an information signal line 46 is arranged between the columns of the pixel electrodes 43. . The gate electrode of each TFT 44 is connected to a corresponding gate line 45, and the drain electrode is connected to a corresponding information signal line 46. The gate line 45 is connected to a row driver via an end 45a, and the information signal line 46 is connected to a column driver via an end 46a. The row driver scans the gate line 45 by applying a gate signal. The column driver applies a signal corresponding to the display data. The gate line 45 is covered with the gate insulating film of the TFT 44 except for the end 45a, and the information signal line 46 is formed on the gate insulating film. The pixel electrode 43 is formed on the gate insulating film, and has one end connected to the source electrode of the TFT 44. Also, the upper substrate 42 of FIG.
Is formed with a transparent electrode 47 facing each pixel electrode 43 of the lower substrate 41. The counter electrode 47 is composed of one electrode having an area covering the entire display area, and a reference voltage is applied thereto. The configuration between the upper and lower substrates is the same as in the simple matrix case. It is also possible to use MIM or the like as a non-linear active element.

The liquid crystal element according to the present invention constitutes a liquid crystal device having various functions. In this example, the liquid crystal element is used for a display panel, and image information having scanning line address information shown in FIGS. The liquid crystal display device is realized by using a data format consisting of SYN signals and communication synchronization means. The reference numerals in the figure are as follows.

101 Liquid crystal display device 102 Graphic controller 103 Display panel 104 Scan line drive circuit 105 Information line drive circuit 106 Decoder 107 Scan line signal generation circuit 108 Shift register 109 Line memory 110 Information signal generation circuit 111 Drive control circuit 112 GCPU 113 Host CPU 11 VRAM

The generation of image information is performed by the graphic controller 102 of the main unit, and is transferred to the display panel 103 according to the signal transmission means shown in FIGS. The graphic controller 102 includes a CPU (central processing unit, abbreviated as GCPU 112) and a VRAM.
(Memory for storing image information) 114
It manages and communicates image information between 13 and the liquid crystal display device 101. Note that a light source is disposed on the back surface of the display panel.

The display device of the present invention, because the liquid crystal element as a display medium has good switching characteristics as described above, exhibits excellent driving characteristics and reliability, and has high definition, high speed,
A large area display image can be obtained.

[0114]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Note that the present invention is not limited to these examples.

Example 1 6- [4- (5-octylthiophen-2-yl) benzenecarbonyloxy] -1,2,3,4-tetrahydro-2-naphthalenecarboxylic acid (R) -1,1,1 -Trifluoro-2-hexyl ester (Exemplary Compound No.
8) Synthesis

[0116]

Embedded image

[0117]

Embedded image

(1) → (2) Price, etc. (Price, CC eta, etc.)
l,) "J. Am. Chem. Soc.", 69, 22.
61 (1947), 6-hydroxynaphthalene-2-carboxylic acid was reduced by the method shown below,
1,2,3,4-tetrahydro-6-hydroxy-2-
Naphthalene carboxylic acid was obtained.

15.2 g (80.8 mmole) of 6-hydroxy-2-naphthalenecarboxylic acid was dissolved in 405 ml of 1-pentanol, heated to 128 to 135 ° C., and heated under a nitrogen stream at the same temperature for 2 hours. 39g
(1.7 mole) was added. After that, 130-135
The mixture was heated and stirred at 3.5 ° C for 3.5 hours. After cooling, methanol (25 ml) was added dropwise at 65 to 70 ° C., and water (800 ml) was further added dropwise, followed by stirring at room temperature for 30 minutes. The reaction mixture was separated to remove the pentanol phase, and the aqueous phase was washed three times with 250 ml of methyl-tert-butyl ether. The aqueous phase is 6N-
The pH was adjusted to 1 with hydrochloric acid, and the precipitated crystals were treated with methyl-ter.
Extraction was performed three times with 300 ml of t-butyl ether. Toluene was added to the organic phase, and the solvent was distilled off to obtain 15 g of pale yellow crystals.

The crystals were dissolved in 500 ml of 1-pentanol and heated to 128 to 136 ° C., and 39 g (1.7 mol) of metallic sodium was heated at the same temperature for 2 hours under a nitrogen stream.
e) was added. Then, it heat-stirred at 130-135 degreeC for 1 hour. Cool to 65-70 ° C and methanol 25ml
Was added dropwise, and 800 ml of water was further added dropwise, followed by stirring at room temperature for 30 minutes. The reaction mixture was separated to remove the pentanol phase, and the aqueous phase was washed with methyl-tert-butyl ether 250
Washed 3 times with ml. The aqueous phase was adjusted to pH = 1 with 6N hydrochloric acid, and the precipitated crystals were collected using methyl-tert-butyl ether 3
The mixture was extracted three times with 00 ml, the organic phase was washed with water, and toluene was added to distill off the solvent to obtain 15 g of pale yellow crystals.

The crystals were purified by silica gel column chromatography (eluent: chloroform / ethanol = 2/1).
Recrystallized with toluene to give 1,2,3,4-tetrahydro-
1-hydroxy-2-naphthalenecarboxylic acid crystals
3.3 g (85.6% yield) was obtained.

(2) → (3) 1,2,3,4-tetrahydro-6-hydroxy-2-
12.3 g of naphthalenecarboxylic acid (60.5 mmol
e) was dissolved in 246 g of ethanol, and 1 lg of concentrated sulfuric acid was added dropwise with stirring at room temperature. After dropping, 79-82 ° C
For 8 hours under reflux. The reaction product was poured into about 1000 ml of ice water, and the precipitated crystals were extracted with toluene. The toluene phase was washed successively with water, a 5% aqueous NaHCO ₃ solution and water, and the solvent was distilled off to obtain 13.3 g of 1,2,3,4-tetrahydro-6-hydroxy-2-naphthalenecarboxylic acid ethyl ester crystals. (95.2% yield).

(3) → (4) → (5) 1,2,3,4-tetrahydro-6-hydroxy-2-
13.2 g of naphthalenecarboxylic acid ethyl ester (6
0.5 mmole) was dissolved in 82 ml of DMF, and 18.7 g of potassium carbonate was added. Under cooling and stirring at 15 to 18 ° C, 11.0 g (64.3 mmole) of benzyl bromide was added dropwise over 15 minutes, followed by stirring at 25 to 30 ° C for 3 hours. The reaction product was poured into about 600 ml of ice water, extracted with toluene, and the organic phase was washed with water. The solvent was distilled off,
An oil of 3,4-tetrahydro-6-benzyloxy-2-naphthalenecarboxylic acid ethyl ester was obtained.

8 g of 85% potassium hydroxide was added to this oil.
Add 103 ml of water and 5 ml of ethanol, and add
The mixture was heated and stirred at ℃ for 2 hours. After adding cold water to the reaction, 6
The precipitated crystals were adjusted to pH = 1 with N-hydrochloric acid and methyl-te
After extraction with rt-butyl ether, the organic phase was washed with water, and toluene was added thereto to distill off the solvent.
I got The crystals were purified by silica gel column chromatography (eluent: chloroform / ethanol = 2/1), recrystallized from toluene to give 1,2,3,4-tetrahydro-6.
13.8 g (yield: 80.8%) of crystals of -benzyloxy-2-naphthalenecarboxylic acid were obtained.

(5) → (6) → (7) 1,2,3,4-tetrahydro-6-benzyloxy-
4.52 g of 2-naphthalenecarboxylic acid (16.0 mmol
le), 2.50 g (16.0 mmole) of (R) -1,1,1-trifluoro-2-hexanol and 55 ml of chloroform were placed in an eggplant-shaped flask, and N, N'-dicyclohexylcarbodiimide was added with stirring at room temperature. 46
g (16.8 mmole) and 0.32 g of 4-dimethylaminopyridine were sequentially added, followed by stirring at room temperature for 20 hours. The precipitated N, N'-dicyclohexylurea was removed by filtration, and the filtrate was dried under reduced pressure. The residue was purified by silica gel column chromatography (eluent: toluene), and 1,2,3,4-tetrahydro-6-benzyloxy-2-naphthalenecarboxylic acid (R) -1,1,1-trifluoro-2-hexyl was used. An ester oil was obtained.

This oily substance was dissolved in 40 ml of ethanol, and 0.93 g of Pd-C (5% Pd) was added, followed by catalytic reduction at room temperature. Pd-C (5% Pd) was removed by filtration, and the filtrate was dried under reduced pressure to give 1,2,3,4-tetrahydro-6-hydroxy-2-naphthalenecarboxylic acid (R) -1,1,1.
3. Oil of 1-trifluoro-2-hexyl ester
73 g (yield 89.% 4) were obtained.

(8) Maleic anhydride 1 was placed in a 2 L reaction vessel.
96 g (2.00 mole), bromobenzene 800 m
1 and 533.4 g of anhydrous aluminum chloride (4.
00 mole) at room temperature in small portions. (Temperature is 40
Thereafter, the temperature was raised to 100 ° C., and the mixture was stirred for 21 hours. After cooling, the reaction solution was poured into a mixed solution of 400 ml of concentrated hydrochloric acid and 1.4 L of ice water. Extract with ethyl acetate,
After washing with water and drying, the solvent was distilled off. The residue was washed with n-hexane, filtered and dried. The crude crystals were dissolved in an aqueous solution of sodium carbonate, and insolubles were removed by filtration. The mother liquor was made acidic by adding concentrated hydrochloric acid, and the precipitated crystals were collected by filtration. This was recrystallized from ethanol to obtain 170 g of compound (8). (Yield 3
3.3%)

(8) → (9) 89 g of compound (8) (3.47 × 10 4) was placed in a 1 L reaction vessel.
^-1 mole), sodium carbonate 38. lg (3.47 ×
10 ^-1 mole) and 500 ml of ethanol, and the mixture was stirred at room temperature for 50 minutes. Thereafter, 44.5 g (3.47 × 10 ⁻¹ mole) of n-octyl aldehyde, 8.9 g of 3-benzyl-5- (2-hydroxyethyl) -4-methylthiazolium chloride, and triethylamine 20
g was added and the mixture was heated under reflux for 7 hours. The reaction solution was concentrated, and the residue was extracted by adding 500 ml of water and 1000 ml of chloroform. The organic layer was washed with 10% sulfuric acid, sat. NaHCO ₃ solution, washed with water, dehydrated with anhydrous magnesium sulfate,
The solvent was distilled off. The residue was recrystallized from ethanol to give 77.8.
g of compound (9) was obtained. (Yield 66.0%)

(9) → (10) 77.8 g (2.2 l ×) of compound (9) was placed in a 1 L reaction vessel.
10 ^-1 mole), Lawesson's Reage
nt 89.4 g (2.2 l × 10 ⁻¹ mole), dry
600 ml of toluene was charged and heated under reflux for 15 minutes. The solvent was distilled off from the reaction solution, and the residue was purified on a silica gel column with n-hexane / ethyl acetate = 10/1.
0 g of compound (10) was obtained. (89.9% yield)

(10) → (11) 60.0 g of the compound (10) was placed in a 500 ml reaction vessel.
(1.68 × 10 ⁻¹ mole), 22.5 g of CuCN
(2.52 × 10 ⁻¹ mole) and 300 ml of DMF were charged and heated to reflux for 21 hours. After cooling, the reaction solution was poured into 1.5 L of water, 50 ml of ethylenediamine was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dehydrated with anhydrous magnesium sulfate, and the solvent was distilled off. The residue was purified on a silica gel column with n-hexane / ethyl acetate = 7/1 to obtain 40.7 g of compound (11). (Yield 81.
2%)

(11) → (12) 30.9 g (1.04 g) of compound (11) was placed in a 1 L reaction vessel.
× 10 ^-1 mole), 30.0 g of potassium hydroxide (5.
37 × 10 ⁻¹ mole), 150 ml of water, 450 ml of ethylene glycol, and 30 g of ethanol were charged and heated under reflux for 21 hours. The reaction solution was poured into 1 L of water, acidified with 6N hydrochloric acid, and the precipitated crystals were filtered, washed with water and dried.
When the crystals were analyzed, they were found to be K salts.
The mixture was stirred at 80 ° C. for 24 hours. After cooling, the crystals were filtered, washed with water and dried. The obtained crude crystals were ethanol-
After recrystallization from chloroform, 21.5 g of 4- (5-octylthiophen-2-yl) benzoic acid [compound (1
2)] was obtained. (Yield 65.4%)

(12) → (Exemplified Compound No. 8) 0.29 g (0.92 mmol) of 4- (5-octylthiophen-2-yl) benzoic acid [compound (12)]
e), 0.30 g (0.9 l) of 1,2,3,4-tetrahydro-6-hydroxy-2-naphthalenecarboxylic acid (R) -1,1,1-trifluoro-2-hexyl ester
mmole) and 3 ml of chloroform in an eggplant-shaped flask, and while stirring at room temperature, 0.19 g (0.92 mmole) of N, N'-dicyclohexylcarbodiimide,
0.2 g of dimethylaminopyridine was added successively, and
Stirred for hours. The precipitated N, N'-dicyclohexylurea was removed by filtration, and the filtrate was dried under reduced pressure. The residue was purified by silica gel column chromatography (eluent: toluene) to give a liquid crystal form of 6- [4- (5-octylthiophen-2-yl) benzenecarbonyloxy] -1,2,3,4-tetrahydro-2-. Naphthalenecarboxylic acid (R) -1,1,1-
Trifluoro-2-hexyl ester (Exemplary Compound N
o. 0.45 g (yield 78.8%) of 8) was obtained.

The phase transition of this compound is shown below.

[0134]

(Equation 3)

Example 2 A liquid crystal composition A was prepared by mixing the following compounds in the following parts by weight.

[0136]

Embedded image

Further, to the liquid crystal composition A, the following exemplified compounds were mixed in the following parts by weight to prepare a liquid crystal composition B.

[0138]

Embedded image

[0139] Two 0.7 mm thick glass plates were prepared.
The ITO film is formed on each of the glass plate, to create a voltage application electrode, and an insulating layer is further deposited SiO ₂ thereon. A silane coupling agent [KBM-602 manufactured by Shin-Etsu Chemical Co., Ltd.] 0.2% isopropyl alcohol solution was rotated on a glass plate at 2000 rpm. p. 1 with m spinner
The coating was performed for 5 seconds to perform a surface treatment. Thereafter, a heat drying treatment was performed at 120 ° C. for 20 minutes.

Further, a polyimide resin precursor [Toray Co., Ltd. SP-
510] 1.5% dimethylacetamide solution at 2 rpm
000r. p. m for 15 seconds. After the film formation, a heating condensation baking treatment at 300 ° C. was performed for 60 minutes.
At this time, the thickness of the coating film was about 250 °.

The baked film is subjected to a rubbing treatment with an acetate flocking cloth, then washed with an isopropyl alcohol solution, and silica beads having an average particle size of 2 μm are sprayed on one of the glass plates. The glass plates were bonded together using an adhesive sealant [Rixson Bond (Chisso Corporation)] so that the axes were parallel to each other, and heated and dried at 100 ° C. for 60 minutes to form a cell.

A liquid crystal composition B was injected into this cell in an isotropic liquid state, and the cell was gradually cooled from the isotropic phase to 25 ° C. at a rate of 20 ° C./h, whereby a ferroelectric liquid crystal element was prepared. When the cell thickness of this cell was measured with a Berek phase plate, it was about 2 μm.
m.

Using this ferroelectric liquid crystal element, an optical response (a change in transmitted light amount of 0 to 90%) under crossed Nicols is detected by applying a peak-to-peak voltage Vpp = 20 V, and the response speed ( Hereinafter, the optical response speed) was measured. The measurement results are shown below.

[0144]

Table 7 10 ° C 25 ° C 40 ° C Response speed 515 μsec 280 μsec 156 μsec

Comparative Example 1 A ferroelectric liquid crystal device was prepared in the same manner as in Example 2 except that the liquid crystal composition A mixed in Example 2 was injected into the cell. The optical response speed was measured. The measurement results are shown below.

[0146]

[Table 8] 10 ° C 25 ° C 40 ° C Response speed 668 μsec 340 μsec 182 μsec

Example 3 A liquid crystal composition C was prepared by mixing the following exemplary compounds in place of the exemplary compounds used in Example 2 in the following parts by weight, respectively.

[0148]

Embedded image

A ferroelectric liquid crystal device was prepared in the same manner as in Example 2 except that the liquid crystal composition C was injected into the cell.
The optical response speed was measured in the same manner as in Example 2, and the switching state was observed. The uniform alignment in the liquid crystal element was good, and a monodomain state was obtained. The measurement results are shown below.

[0150]

Table 9 10 ° C 25 ° C 40 ° C Response speed 505 μsec 272 μsec 151 μsec

Example 4 A liquid crystal composition D was prepared by mixing the following compounds in the following parts by weight.

[0152]

Embedded image

Further, to the liquid crystal composition D, the following exemplified compounds were mixed in the following parts by weight, respectively, to prepare a liquid crystal composition E.

[0154]

Embedded image

Next, the optical response was observed using cells prepared from these liquid crystal compositions according to the following procedure. Two glass plates having a thickness of 0.7 mm were prepared, an ITO film was formed on each of the glass plates, a voltage application electrode was formed, and SiO ₂ was deposited thereon to form an insulating layer. Silane coupling agent [KBM- manufactured by Shin-Etsu Chemical Co., Ltd.]
602] 0.2% isopropyl alcohol solution at 2000 rpm. p. m for 15 seconds to give a surface treatment. Thereafter, a heat drying treatment was performed at 120 ° C. for 20 minutes.

A polyimide resin precursor [Toray Co., Ltd. SP-
510] 1.0% dimethylacetamide solution at 3 rpm
000r. p. m for 15 seconds. After the film formation, a heating condensation baking treatment at 300 ° C. was performed for 60 minutes.
At this time, the thickness of the coating film was about 120 °.

The baked film was subjected to a rubbing treatment with an acetate flocking cloth, then washed with an isopropyl alcohol solution, and silica beads having an average particle size of 1.5 μm were sprayed on one glass plate. The rubbing axes were made parallel to each other, the glass plates were bonded together using an adhesive sealant [Rixson Bond (Chisso Corporation)], and heated and dried at 100 ° C. for 60 minutes to form a cell.

When the cell thickness of this cell was measured with a Berek phase plate, it was about 1.5 μm. The liquid crystal composition E was injected into this cell in an isotropic liquid state,
By slowly cooling to 25 ° C at a rate of ° C / h, a ferroelectric liquid crystal element was prepared.

Using this ferroelectric liquid crystal element, the contrast at the time of driving at 30 ° C. under the driving waveform (1/3 bias ratio) shown in FIG. 5 was 16.2.

Comparative Example 2 A ferroelectric liquid crystal device was prepared in the same manner as in Example 4 except that the liquid crystal composition D mixed in Example 4 was injected into the cell, and the same driving waveform was used at 30 ° C. At the time of driving was measured. As a result, the contrast is 7.
It was 8.

Example 5 A liquid crystal composition F was prepared by mixing the following exemplary compounds in place of the exemplary compounds used in Example 4 in the following parts by weight, respectively.

[0162]

Embedded image

A ferroelectric liquid crystal device was prepared in the same manner as in Example 4 except that this liquid crystal composition was used.
The contrast at the time of driving at 30 ° C. was measured using the same driving waveforms as in the above. As a result, the contrast is 18.
It was 4.

Example 6 A liquid crystal composition G was prepared by mixing the following exemplary compounds in place of the exemplary compounds used in Example 4 in the following parts by weight, respectively.

[0165]

Embedded image

A ferroelectric liquid crystal device was prepared in the same manner as in Example 4 except that this liquid crystal composition was used.
The contrast at the time of driving at 30 ° C. was measured using the same driving waveforms as in the above. As a result, the contrast is 19.
It was 2.

As is clear from Examples 4 to 6, the ferroelectric liquid crystal device containing the liquid crystal compositions E, F and G according to the present invention has a high contrast at the time of driving.

Example 7 CS-4000, a standard antiferroelectric liquid crystal composition
(Manufactured by Chisso Petrochemical Co., Ltd.) has the following exemplified compound No. 8 in the following parts by weight, and a liquid crystal composition H
I got Liquid crystal composition HCS-4000 / No. 2 = 80wt
% / 20 wt% The phase transition temperature of the obtained liquid crystal composition H is shown below.

[0169]

(Equation 4)

Cry: crystalline phase, ScAX *: higher-order antiferroelectric phase, ScA *: antiferroelectric phase, SA: smectic A phase, Iso: isotropic phase

Next, two 0.7 mm-thick glass plates were prepared, an ITO film was formed on each of the glass plates, and SiO ₂ was deposited thereon to form an insulating layer. A silane coupling agent [Shin-Etsu Chemical Co., Ltd.
KBM-602] A 0.2% isopropyl alcohol solution was rotated at 2000 rpm. p. m. For 15 seconds to give a surface treatment. Thereafter, a heat drying treatment was performed at 120 ° C. for 20 minutes. ITO with further surface treatment
A 1.5% dimethylacetamide solution of a polyimide resin precursor [manufactured by Toray Industries, Ltd., SP-710] was 2,000 rpm on a glass plate with a film. p. m. 15 in the spinner
Coated for seconds. After the film formation, a heat condensation baking treatment was performed at 300 ° C. for 60 minutes. At this time, the thickness of the coating film was about 250 °.

The baked film was subjected to a rubbing treatment with an acetate flocking cloth, then washed with an isopropyl alcohol solution, and silica beads having an average particle size of 1.5 μm were sprayed on one glass plate. The rubbing treatment axes were made parallel to each other, and a glass plate was bonded using an adhesive sealant [Mitsui Toatsu Co., Ltd., Stract Bond], and heated and dried at 170 ° C. for 60 minutes to form a cell.

A liquid crystal composition H was injected into the cell in an isotropic liquid state, and the cell was gradually cooled from the isotropic phase to 25 ° C. at a rate of 20 ° C./h to prepare a liquid crystal element. The cell thickness of this cell was about 1.5 μm when measured with a Berek phase plate. Using this device, the magnitude of spontaneous polarization at 30 ° C. and the optical response under crossed Nicols (0 to 90% change in transmitted light amount) are detected by applying a voltage of peak-to-peak voltage Vpp = 20 V / μm. The response speed was measured and the switching state was observed.
There were three streak-like defects in the visual field range of m ² .

Comparative Example 3 A liquid crystal device was prepared in the same manner as in Example 7, except that CS-4000 (manufactured by Chisso Petrochemical Co., Ltd.), which is an antiferroelectric liquid crystal composition, was injected into the cell. The spontaneous polarization and the response speed were measured in the same manner as in Example 7, and the switching state was observed.
^The number of streak-like defects in the field of view ² was 23.

Example 8 The following compound F was used as the ferrielectric compound AFLC-1.
o. 8 was mixed in the following parts by weight to obtain a liquid crystal composition I.

[0176]

Embedded image AFLC-1 C ₁₀ H ₂₁ -Ph-Ph-COO-Nh1-COOC ^* H
(CF ₃ ) C ₄ H ₉

[0177]

(Equation 5)

Liquid Crystal Composition I AFLC-1 / No8 = 80 wt% / 20 wt% The phase transition temperature of the obtained liquid crystal composition I is shown below.

[0179]

(Equation 6)

Cry: crystalline phase, ScA *: antiferroelectric phase, Scγ *: ferrielectric phase, SA: smectic A
Phase, Iso: isotropic phase

A liquid crystal device was prepared in the same manner as in Example 7 except that the liquid crystal composition I was injected into the cell. In the switching state, there were four streak-like defects in the viewing area of 0.3 mm ² in the liquid crystal element.

Examples 9 to 11 An antiferroelectric liquid crystal composition CS-4000 (manufactured by Chisso Petrochemical Co., Ltd.) was mixed with the exemplified compounds shown below in parts by weight shown in Table 10 below to obtain a liquid crystal composition. J to L were obtained.

[0183]

[Table 10]

Each of the obtained liquid crystal compositions J to L exhibited a stable antiferroelectric phase in a room temperature region.

[0185] creates a liquid crystal element in the same manner exactly Example 7 except that the injection of these liquid crystal compositions J~L into the cell, the streaky defect in the visual field range of 0.3 mm ² in the liquid crystal element The results of the counts are shown in Table 11 below.

[0186]

[Table 11]

As is apparent from Examples 7 to 11, it is recognized that the liquid crystal devices containing the liquid crystal compositions H to L according to the present invention have improved alignment.

[0188]

As described above, the liquid crystal composition containing the thiophene compound of the present invention can be operated using the ferroelectricity of the liquid crystal composition. The ferroelectric liquid crystal device of the present invention which can be used in this manner is a liquid crystal device having excellent characteristics such as good switching characteristics, high-speed response, reduced temperature dependence of optical response speed, and high contrast. be able to.

Further, the liquid crystal composition of the present invention can be operated utilizing the antiferroelectricity exhibited by the liquid crystal composition.
The liquid crystal element of the present invention which can be used in this way has good switching characteristics and excellent alignment.

Note that a liquid crystal device in which the liquid crystal element of the present invention is combined with a light source, a driving circuit, and the like as a display element is a good display device.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of a liquid crystal device using the liquid crystal composition of the present invention.

FIG. 2 is a perspective view schematically showing an example of an element cell for explaining the operation of a liquid crystal element utilizing the ferroelectricity of liquid crystal.

FIG. 3 is a perspective view schematically showing an example of an element cell for explaining the operation of a liquid crystal element utilizing the ferroelectricity of liquid crystal.

FIG. 4 is an explanatory diagram showing a tilt angle (θ).

FIG. 5 is a waveform chart of a driving method of a liquid crystal element used in the present invention.

FIG. 6 is a schematic diagram of a display pattern when actual driving is performed with the time-series driving waveform shown in FIG.

FIG. 7 is a block diagram showing a liquid crystal display device having a liquid crystal element utilizing ferroelectricity and a graphics controller.

FIG. 8 is a timing chart of image information communication between a liquid crystal display device and a graphics controller.

FIG. 9 is a diagram showing waveforms of a driving method used in the present invention.

FIG. 10 is a schematic view showing another example of the structure of the liquid crystal element of the present invention.

11 is a plan view showing a configuration of a lower substrate of the liquid crystal element shown in FIG.

[Explanation of symbols]

Reference Signs List 1 liquid crystal layer having chiral smectic phase 2 glass substrate 3 transparent electrode 4 insulating alignment control layer 5 spacer 6 lead wire 7 power supply 8 polarizing plate 9 light source I ₀ incident light I transmitted light 10 sealing material 11 antiferroelectric liquid crystal (AFLC) 12) gap material 13, 14 polarizing plate 21a substrate 21b substrate 22 liquid crystal layer having chiral smectic phase 23 liquid crystal molecule 24 dipole moment (P 双) 31a voltage applying means 31b voltage applying means 33a first stable state 33b second Stable state 34a Upward dipole moment 34b Downward dipole moment Ea Upward electric field Eb Downward electric field 41 Lower transparent substrate 42 Upper transparent substrate 43 Pixel electrode 44 Active element (TFT) 45 Gate line (scanning line) 46 Data line (Grayscale signal line) 47 Opposite Electrode 101 Liquid crystal display device 102 Graphics controller 103 Display panel 104 Scan line drive circuit 105 Information line drive circuit 106 Decoder 107 Scan signal generation circuit 108 Shift register 109 Line memory 110 Information signal generation circuit 111 Drive control circuit 112 GCPU 113 Host CPU 114 VRAM

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yukio Hanyu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Koichi Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Non Corporation (72) Inventor Yasushi Shimizu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Corporation (72) Inventor Koji Noguchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Corporation F-term (reference) 4C023 EA11 4C063 AA01 BB01 BB04 CC92 CC97 DD12 DD14 DD28 DD34 DD52 DD62 DD67 DD76 DD82 DD92 EE10 4H027 BA06 BB09 BC05 BD19 BD20 BD23 BE04 CB01 CB03 CE01 CE03 CF01 CL09 DB01 DB07 DC01 DE01 DF01 DE03

Claims (19)

[Claims] 1. A thiophene compound comprising a compound represented by the following general formula (I). Embedded image [Wherein, R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 20 carbon atoms. However, one or two or more -CH ₂ in the alkyl group - is -O under the condition that heteroatoms are not adjacent -, - S -, - CO -, - C
H = CH-, -C≡C-, -C * HF-, -C * H (C
F ₃ )-. * Is an asymmetric carbon. A ₁ and A ₂ are each independently unsubstituted or 1,4-phenylene, pyridine-2,5-diyl having one or two substituents selected from F, Cl, Br, CH ₃ and CF ₃ ; Pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl,
1,4-cyclohexylene, 1,3,2-dioxaborinane-2,5-diyl, 1,3-dioxane-2,5-
Diyl, 1,3-dithiane-2,5-diyl, benzoxazole-2,5-diyl, benzoxazole-
2,6-diyl, benzothiazole-2,5-diyl,
Benzothiazole-2,6-diyl, benzofuran-
2,5-diyl, benzofuran-2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6- Naphthylene, indan-2,5-diyl,
2-alkylindan-2,5-diyl (the alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), coumaran-2,5-diyl, 2-alkylcoumaran-2 , 5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl, thiazole-
It is selected from 2,5-diyl and thiadiazole-2,5-diyl. A ₃ and A ₄ are each independently a single bond or unsubstituted or one or two F, Cl, Br,
1,4 having a substituent selected from CH ₃ and CF ₃
-Phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, pyrazine-2,5-diyl, pyridazine-3,6-diyl, 1,4-cyclohexylene,
1,3,2-dioxaborinane-2,5-diyl, 1,
3-dioxane-2,5-diyl, 1,3-dithiane-
2,5-diyl, benzoxazole-2,5-diyl, benzoxazole-2,6-diyl, benzothiazole-2,5-diyl, benzothiazole-2,6-
Diyl, benzofuran-2,5-diyl, benzofuran-2,6-diyl, quinoxaline-2,6-diyl, quinolin-2,6-diyl, 1,2,3,4-tetrahydro-2,6-naphthylene, 2,6-naphthylene, indan-2,5-diyl, 2-alkylindan-2,5-
Diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), coumaran-2,5
-Diyl, 2-alkylcoumaran-2,5-diyl (an alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms), thiophen-2,5-diyl, thiazole-2 , 5-diyl, thiadiazole-
Selected from 2,5-diyl. Provided that at least one of A ₁ and A ₂ is thiophene-2,5-diyl;
_3, at least one of A ₄ is a 1,2,3,4-tetrahydro-2,6-naphthylene. B ₁ and B ₂ are a single bond, —COO—, —OOC—, —CH ₂ O—, —OC
H ₂ —, —CH ₂ CH ₂ —, —CH ＝ CH— or —C
≡C−. ] 2. The thiophene compound according to claim 1, wherein in formula (I), one of A ₃ and A ₄ is a single bond. 3. In the general formula (I), one of A ₃ and A ₄ is a single bond, and A ₁ , A ₂ , A ₃ ,
Any one is unsubstituted or one A ₄ or two F, Cl, Br, claim 1 thiophene compound according 1,4-phenylene having a substituent selected from CH ₃ and CF _3. 4. The thiophene compound according to claim 1, wherein the compound represented by the general formula (I) is an optically active compound. 5. The thiophene compound according to claim 1, wherein the compound represented by the general formula (I) is a non-optically active compound. 6. A liquid crystal composition comprising at least one thiophene compound according to claim 1. Description: 7. The content of the thiophene compound is 1 to 8
The liquid crystal composition according to claim 6, which is 0% by weight. 8. The content of the thiophene compound is 1 to 6.
The liquid crystal composition according to claim 6, which is 0% by weight. 9. The content of the thiophene compound is from 1 to 4.
The liquid crystal composition according to claim 6, which is 0% by weight. 10. The liquid crystal composition according to claim 6, wherein the liquid crystal composition does not have a chiral smectic C phase. 11. A liquid crystal device comprising the liquid crystal composition according to claim 6 disposed between a pair of electrode substrates. 12. The liquid crystal device according to claim 11, wherein an alignment control layer is further provided on the electrode substrate on a side in contact with the liquid crystal composition. 13. The liquid crystal device according to claim 12, wherein the alignment control layer is a rubbed layer. 14. The liquid crystal device according to claim 13, wherein the liquid crystal element is provided between the pair of electrode substrates at a film thickness in which a helical structure formed by the arrangement of liquid crystal molecules is released. 15. The liquid crystal device according to claim 11, wherein a thin film transistor or a non-linear active element is provided on the electrode substrate. 16. A display device comprising the liquid crystal element according to claim 11 as a display element. 17. The display device according to claim 16, further comprising a driving circuit for driving a liquid crystal element. 18. The display device according to claim 17, further comprising a light source. 19. A display method, wherein a display image is obtained by controlling the liquid crystal composition according to claim 6 according to image information.