JPH0517408A - Optically active compound and display device - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Difficult to do with conventional ferroelectric smectic liquid crystals,
Disclosed is an antiferroelectric liquid crystal material that can obtain stable molecular orientation in a large area and is excellent in high-speed response, and a liquid crystal display device using the same. [Structure] An optically active compound represented by the following general formula. [R ¹ represents an alkyl group having 4 to 16 carbon atoms, R ^1
2 represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ] Specifically, for example, (R) -4'-decyloxybiphenyl-4-carboxylic acid-4- [2- (1-
An optically active compound comprising trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester and analogs thereof, and a liquid crystal display device using the same.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optically active compound and a display device using the same. More specifically, the compound of the present invention is expected to be used as a liquid crystal compound, and relates to an antiferroelectric liquid crystal material exhibiting a chiral smectic C _A phase having a tristable state, and a liquid crystal display device using the same. Is.

[0002]

2. Description of the Related Art At present, liquid crystal display elements are widely used as various display elements from the viewpoints of low voltage drivability, low power consumption, small size and thinness. Recently, as a fast response liquid crystal device, a device using a ferroelectric smectic liquid crystal has been vigorously studied. Ferroelectric smectic liquid crystals are known to have a large driving force in interaction with an electric field and exhibit a high-speed response to a change in the electric field because they have spontaneous polarization. Utilizing this high-speed response, research on display elements such as liquid crystal televisions and elements for optoelectronics such as optical printers and light valves is under way.

At present, most of the ferroelectric liquid crystal phases that are about to be used in these devices are chiral smectic C phases, and display is performed in the surface stable ferroelectric liquid crystal mode. It uses two stable states. However, in this surface-stabilized ferroelectric liquid crystal mode, it is difficult to obtain an ideal molecular orientation state of a monodomain state in a large area, and defects or disorder of molecular orientation called twist occur. There is a problem of doing.

On the other hand, an antiferroelectric liquid crystal compound having a tristable state because it exhibits a chiral smectic C _A phase is displayed by a surface stable mode, but it is known that a stable molecular orientation can be obtained in a large area. ing. For example, Japanese Patent Laid-Open No. 2-
In Japanese Patent No. 160748, 4'is used as an antiferroelectric liquid crystal compound.
-Octyloxybiphenyl-4-carboxylic acid-4-
[1- (Trifluoromethyl) heptyloxycarbonyl] phenyl ester is disclosed.

[0005]

DISCLOSURE OF THE INVENTION The present invention is an antiferroelectric liquid crystal compound having a tristable state capable of obtaining a stable molecular orientation in a large area, which is difficult with a conventional ferroelectric smectic liquid crystal. Thus, the present invention provides a liquid crystal compound having a chemical structure different from that of a conventionally known antiferroelectric liquid crystal compound and a liquid crystal display device using the same.

[0006]

The present inventors have completed the present invention as a result of intensive studies to achieve the above object. That is, the present invention, the following general formula (1)

[0007]

[Chemical 3]

[However, in the above general formula (1), R ¹ has 4 carbon atoms.
To 16 alkyl groups, R ² represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ] The optically active compound shown by these, and the display element characterized by using it.

The optically active compound of the present invention is a compound useful as an antiferroelectric liquid crystal material showing a chiral smectic C _A phase having a tristable state.

In the above general formula (1), R ¹ has 4 to 4 carbon atoms.
Examples of the alkyl group of 16 include linear groups such as butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group and hexadecyl group. Alternatively, a branched alkyl group can be exemplified.

On the other hand, the alkyl group having 4 to 12 carbon atoms represented by R ² is a linear group such as butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group. Alternatively, a branched alkyl group can be exemplified.

[General Method for Producing Compound of the Present Invention] The compound represented by the general formula (1) of the present invention can be produced by the following method. As illustrated in the reaction formula below, R ¹ and R ² in the formula are the same as those defined in the general formula (1), and the number in the formula () represents the upper compound. Reaction formula :

[0013]

[Chemical 4]

The reaction step I can be easily carried out by using sulfuric acid or boric acid as a catalyst, toluene as a solvent, and dehydration under reflux. The reaction step II can be easily carried out by using dicyclohexylcarbodiimide or the like as a dehydration condensing agent, an organic base such as N, N-dimethyl-4-aminopyridine or the like as a catalyst, and methylene chloride or chloroform or the like as a solvent. The compound of the general formula (1), which is the object compound of the present invention, can be easily derived.

[Exemplary Compounds of the Present Invention] The following compounds are exemplified as the optically active compounds used in the present invention.

No. 1: (S) -4'-hexyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylpentyloxycarbonyl) ethenyl] phenyl ester,

No. 2: (S) -4'-octyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylpentyloxycarbonyl) ethenyl] phenyl ester,

No. 3: (S) -4'-decyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylpentyloxycarbonyl) ethenyl] phenyl ester,

No. 4: (S) -4'-dodecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylpentyloxycarbonyl) ethenyl] phenyl ester,

No. 5: (S) -4'-tetradecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylpentyloxycarbonyl) ethenyl]
Phenyl ester,

No. 6: (R) -4'-hexyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester,

No. 7: (R) -4'-octyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester,

No. 8: (R) -4'-decyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester,

No. 9: (R) -4'-dodecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl)] ethenyl] phenyl ester,

No. 10: (R) -4'-tetradecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester,

No. 11: (S) -4'-hexyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylnonyloxycarbonyl) ethenyl] phenyl ester,

No. 12: (S) -4'-octyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylnonyloxycarbonyl) ethenyl] phenyl ester,

No. 13: (S) -4'-decyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylnonyloxycarbonyl) ethenyl] phenyl ester,

No. 14: (S) -4'-dodecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylnonyloxycarbonyl) ethenyl] phenyl ester,

No. 15: (S) -4'-tetradecyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylnonyloxycarbonyl) ethenyl]
Phenyl ester,

[Liquid Crystal Display Element] In the production of the liquid crystal display element of the present invention, a liquid crystal compound is placed in a cell obtained by laminating two glass substrates each having a transparent electrode and surface-aligned with a spacer interposed therebetween. It can be carried out by injection. For manufacturing the cell, a conventional liquid crystal element manufacturing technique using a liquid crystal compound having a chiral smectic C phase can be applied. For example, as the spacer, alumina beads,
Glass fiber, polyester film or the like can be used. Further, as the orientation treatment material, PVA, P
Examples thereof include I, SiO and SiO ₂ .

[0032]

Industrial Applicability The optically active compound according to the present invention has useful properties as an antiferroelectric liquid crystal material exhibiting a chiral smectic C _A phase having a tristable state. Therefore, a liquid crystal display device using this optically active compound as a liquid crystal material can obtain stable molecular alignment in a large area. In addition, halftone display is possible by utilizing the tristable state. Such characteristics give the liquid crystal display device of the present invention the possibility of being used more than conventional products.

[0033]

The present invention will be described in more detail with reference to the following examples. In addition, the measurement of the phase transition temperature and the identification of the phase in the examples were carried out by the DSC measurement and the observation with a polarizing microscope.

[Example 1] (R) -4'-decyloxybiphenyl-4-carboxylic acid-4- [2- (1-trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester

(1)(R) -4-hydroxycinnamic acid-
Production of 1-trifluoromethylheptyl ester   4-hydroxycinnamic acid 847 mg (5.16 mmol)
(R) -1,1,1-trifluoro-2-octanol 9
50 mg (5.16 mmol) were dissolved in 20 ml toluene.
After that, sulfuric acid 24 mg (0.25 mmol), boric acid 16 mg (0.2
5 mmol) was added and the mixture was reacted under reflux for 3 hours. End of reaction
After that, the reaction solution was extracted with ether, and the ether layer was washed with water,
It was dried over anhydrous magnesium sulfate. The desiccant was filtered off
After that, ether was distilled off to obtain a crude product. Siri this
Purified by Kagel chromatography, oily (R)
-3- (4-hydroxyphenyl) propionic acid-1-
Trifluoromethylheptyl ester 1177 mg (3.
52 mmol) was obtained.

(2)(R) -4′-decyloxybife
Nyl-4-carboxylic acid-4- [2- (1-trifluoro
Methylheptyloxycarbonyl) ethenyl] phenyl
Production of ester   (R) -4-hydroxycinnamic acid obtained in the above (1)
-1-Trifluoromethylheptyl ester 247 mg
(0.75 mmol), 4'-decyloxybiphenyl-4
-Carboxylic acid 399 mg (1.13 mmol) and N, N-di
73 mg (0.60 mmol) methyl-4-aminopyridine
After dissolving in 10 ml of methylene chloride at room temperature, dicyclohexane was added.
Add 310 mg (1.50 mmol) of xylcarbodiimide.
Then, the reaction was carried out at room temperature for 17 hours.

After completion of the reaction, the precipitated solid matter was separated by filtration, washed with water, washed with a 5% acetic acid aqueous solution, washed with water, and then dried over anhydrous magnesium sulfate. After filtering off the desiccant, methylene chloride was distilled off to obtain a crude product. This was purified by silica gel chromatography and recrystallized from hexane to give the desired (R) -4′-decyloxybiphenyl-4-carboxylic acid-4- [2- (1
407 mg (0.61 mmol) of -trifluoromethylheptyloxycarbonyl) ethenyl] phenyl ester were obtained.

¹ H-NMR spectrum (CDCl ₃ , pp
m) : 0.88 (t, 3H), 0.89 (t, 3H), 1.26-1.50 (m, 22H), 1.78-1.8
5 (m, 4H), 4.02 (t, 2H), 5.43 (m, 1H), 6.47 (d, 1H), 7.00
(d, 2H), 7.30 (d, 2H), 7.60 (d, 2H), 7.63 (d, 2H), 7.70
(d, 2H), 7.78 (d, 2H), 8.23 (d, 2H)

IR spectrum (KBr disk, c
m ^-1 ) : 2920, 2850, 1740, 1720, 1640, 1600, 1510, 1400, 13
00, 1270, 1180, 1070, 980, 860, 830, 770 Mass spectrum (FAB method, m / e (relative intensity)) : 667 (25, MH +), 666 (12, M +), 337 (100) phase transition temperature (DSC, polarizing microscopy, ° C.): Note that in the following formulas, Cry crystal phase, SmC _A * is a chiral smectic C _A phase, SmA a smectic A phase, lso
Represents an isotropic phase.

[0040]

[Chemical 5]

[Example 2] A glass substrate having two transparent electrodes was coated with polyimide and then assembled in a cell having a glass substrate spacing of 2 µm so that the rubbing directions were parallel to each other. A liquid crystal device was produced by injecting the compound obtained in 1 and sandwiching it between two polarizing plates which are orthogonal to each other. When the optical response speed of this product was measured by applying a voltage of ± 60 V at 90 ° C., a very fast response time of 40 μsec was obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsuyoshi Suzuki             8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture             Inside the Tsukuba Research Institute, Mitsubishi Petrochemical Co., Ltd. (72) Inventor Noriko Iimura             8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture             Inside the Tsukuba Research Institute, Mitsubishi Petrochemical Co., Ltd.

Claims (2)

[Claims] 1. An optically active compound represented by the following general formula (1). [Chemical 1] [Wherein, in the general formula (1), R ¹ represents an alkyl group having 4 to 16 carbon atoms, R ² represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ] 2. A display device comprising an optically active compound represented by the following general formula (1). [Chemical 2] [Wherein, in the general formula (1), R ¹ represents an alkyl group having 4 to 16 carbon atoms, R ² represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ]