JPH04312552A - Optically active compound and display element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optically active compound and a display element 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 CA phase having a tristable state, and a liquid crystal display element using the same. be.

0002

2. Description of the Related Art Currently, liquid crystal display elements are widely used as various display elements due to their low voltage drive performance, low power consumption, small size, and thinness. Recently, high-speed response liquid crystal devices using ferroelectric smectic liquid crystals have been actively researched. Since ferroelectric smectic liquid crystals have spontaneous polarization, it is known that they have a large driving force when interacting with an electric field and exhibit high-speed response to changes in the electric field. Utilizing this high-speed response, research is progressing into display elements such as liquid crystal televisions, and optoelectronic elements such as optical printers and light valves.

[0003] Currently, most of the ferroelectric liquid crystal phases that are being used in these devices are chiral smectic C phases, which attempt to perform display in a surface-stabilized ferroelectric liquid crystal mode, in which molecules are This method uses two stable states. However, in this surface-stabilized ferroelectric liquid crystal mode, it is difficult to obtain the monodomain state, an ideal molecular orientation state, over a large area, resulting in defects and disturbances in molecular orientation called twist. There is a problem with that.

On the other hand, as an antiferroelectric liquid crystal material exhibiting a chiral smectic CA phase having a tristable state and capable of obtaining stable molecular orientation over a large area, for example, 4'-octyloxybiphenyl-4-carboxylic acid-4 -[1-(trifluoromethyl)heptyloxycarbonyl]phenyl ester (Japanese Unexamined Patent Publication No. 2-160748) is known, and an element using a composition composed of a tricyclic ester compound as a liquid crystal display element ( JP 1-213390
Publication No.) is known.

[0005]

SUMMARY OF THE INVENTION The present invention provides an antiferroelectric liquid crystal compound having three stable states, which is capable of obtaining stable molecular alignment over a large area, which is difficult to achieve with conventional ferroelectric smectic liquid crystals. The object of the present invention is to provide an optically active compound having a chemical structure different from conventionally known antiferroelectric liquid crystal compounds, and a liquid crystal display device using the same.

[0006]

[Means for Solving the Problems] The present inventors have conducted intensive studies to achieve the above object, and as a result, have completed the present invention. That is, the present invention provides the following general formula (1)

0
007]

[Chemical formula 3]

[However, in the above general formula (1), R1 represents an alkyl group having 4 to 16 carbon atoms, and R2 represents an alkyl group having 4 to 1 carbon atoms.
2 represents an alkyl group, and * represents optical activity. ] and a display element using the optically active compound.

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

In the above general formula (1), the alkyl group having 4 to 16 carbon atoms for R1 includes butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, Examples include linear or branched alkyl groups such as a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, and a hexadecyl group.

On the other hand, the alkyl group having 4 to 12 carbon atoms for R2 is a linear or , a branched alkyl group can be exemplified.

[General method for producing the compound of the present invention] The compound represented by the general formula (1) of the present invention can be produced by the method shown below. The reaction formula is illustrated below, in which R1 and R2 are the same as defined in general formula (1), and the number in parentheses in the formula represents the compound in the upper row. Reaction formula:

[0013]

[C4]

Reaction step I can be easily carried out by using copper and β-cyclodextrin as a catalyst and reacting carbon tetrachloride in the presence of sodium hydroxide. Reaction step II can be easily carried out by using sulfuric acid or boric acid as a catalyst, toluene as a solvent, and dehydration under reflux. Reaction step III can be easily carried out by using dicyclohexylcarbodiimide etc. as a dehydration condensation agent, using an organic base such as N,N-dimethyl-4-aminopyridine as a catalyst, and using methylene chloride, chloroform, etc. as a solvent. This can easily lead to the compound of general formula (1), which is the target compound of the present invention.

[Examples of Compounds of the Present Invention] Examples of the optically active compounds used in the present invention include the following compounds.

[0016]No. 1: (S)-4'-hexylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl)-2-fluorophenyl ester,

[0017]No. 2: (S)-4'-octylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl)-2-fluorophenyl ester,

[0018]No. 3: (S)-4'-decylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl)-2-fluorophenyl ester,

[0019]No. 4: (S)-4'-dodecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl)-2-fluorophenyl ester,

[0020]No. 5: (S)-4'-tetradecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylpentyloxycarbonyl)-2-fluorophenyl ester,

[0021]No. 6: (R)-4'-hexylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester,

[0022]No. 7: (R)-4'-octylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester,

[0023]No. 8: (R)-4'-decylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester,

[0024]No. 9: (R)-4'-dodecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester,

[0025]No. 10: (R)-4'-tetradecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester,

[0026]No. 11: (S)-4'-hexylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylnonyloxycarbonyl)-2-fluorophenyl ester,

[0027]No. 12: (S)-4'-octylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylnonyloxycarbonyl)-2-fluorophenyl ester,

[0028]No. 13: (S)-4'-decylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylnonyloxycarbonyl)-2-fluorophenyl ester,

[0029]No. 14: (S)-4'-dodecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylnonyloxycarbonyl)-2-fluorophenyl ester,

[0030]No. 15: (S)-4'-tetradecylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylnonyloxycarbonyl)-2-fluorophenyl ester,

[Liquid Crystal Display Element] The liquid crystal display element of the present invention is manufactured by applying a liquid crystal compound to a cell obtained by laminating two glass substrates with transparent electrodes and alignment-treated surfaces with a spacer in between. This can be done by injection. For the production of the cell, a conventional technique for producing a liquid crystal element using a liquid crystal compound having a chiral smectic C phase can be applied. For example, as a spacer, alumina beads,
Glass fiber, polyester film, etc. can be used. In addition, as alignment treatment materials, PVA, P
Examples include I, SiO, and SiO2.

[0032]

Effects of the Invention The optically active compound according to the present invention has useful performance as an antiferroelectric liquid crystal material exhibiting a chiral smectic CA phase having a tristable state. Therefore, a liquid crystal display element using this optically active compound as a liquid crystal material can obtain stable molecular alignment over a large area. Furthermore, halftone display is also possible using the three stable states. Such characteristics allow the liquid crystal display element of the present invention to be used in more ways than conventional products.

[0033]

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

[Example 1] (R)-4'-decylbiphenyl-4-carboxylic acid-4
-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester

(1) Production of 3-fluoro-4-hydroxybenzoic acid 2-fluorophenol 4.48 g (40 mmol)
was dissolved in 25 ml of 20% aqueous sodium hydroxide solution, 254 mg (4.0 mmol) of copper powder, 3.64 g (3.2 mmol) of β-cyclodextrin and 49.0 g (320 mmol) of carbon tetrachloride were added, and the mixture was heated at 80°C. 1
The reaction was allowed to proceed for 5 hours. After the reaction was completed, the reaction solution was made acidic with hydrochloric acid, extracted with methylene chloride, and the organic layer was washed with water and dried over anhydrous magnesium sulfate. After the desiccant was filtered off, methylene chloride was distilled off to obtain the crude target product. This product was purified by silica gel chromatography to obtain 2.87 g (18.4 mmol) of 3-fluoro-4-hydroxybenzoic acid.
l) was obtained.

(2) Production of (R)-3-fluoro-4-hydroxybenzoic acid-1-trifluoromethylheptyl ester 156 mg of 3-fluoro-4-hydroxybenzoic acid obtained in the above (1) (1. 00 mmol) and (R)-1,
1,1-trifluoro-2-octanol 184 mg (
After dissolving 1.00 mmol) in 10 ml of toluene,
5 mg (0.05 mmol) of sulfuric acid, 3 mg (0.05 mmol) of boric acid.
05 mmol) was added thereto, and the mixture was reacted under reflux for 4 hours. After the reaction was completed, the reaction solution was extracted with ether, and the ether layer was washed with water and dried over anhydrous magnesium sulfate. After the desiccant was filtered off, the ether was distilled off to obtain the crude target product. This product was purified by silica gel chromatography to obtain oily (R)-3-fluoro-4-hydroxybenzoic acid-1-
Trifluoromethylheptyl ester 255 mg (0.
79 mmol) was obtained.

(3) Production of (R)-4'-decylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2-fluorophenyl ester (obtained in (2) above) R)-3-fluoro-4-hydroxybenzoic acid-1-trifluoromethylheptyl ester 220 mg (0.70 mmol), 4'-decylbiphenyl-4-carboxylic acid 296 mg (0.90 mmol)
l) and N,N-dimethyl-4-aminopyridine 50m
g (0.41 mmol) in 10 ml of methylene chloride at room temperature, dicyclohexylcarbodiimide 22
0 mg (1.10 mmol) was added and reacted at room temperature for 1 hour.

After completion of the reaction, the precipitated solid was separated by filtration, washed with water, washed with a 5% aqueous acetic acid solution, washed with water, and then dried over anhydrous magnesium sulfate. After the desiccant was filtered off, methylene chloride was distilled off to obtain the crude target product. This product was purified by silica gel chromatography and further recrystallized from hexane to obtain the desired (R)-4'-decylbiphenyl-4-carboxylic acid-4-(1-trifluoromethylheptyloxycarbonyl)-2- 350 mg (0.54 mmol) of fluorophenyl ester was obtained.

1H-NMR spectrum (CDCl3,p
pm): 0.88 (t, 6H), 1.27-1.36 (m, 22
H), 1.64-1.66 (m, 2H), 1.87-
1.90 (m, 2H), 2.65-2.70 (m, 2H
), 5.54-5.55 (m, 1H), 7.30 (
d, 2H), 7.42 (t, 1H), 7.58 (d, 2H)
H), 7.74 (d, 2H), 7.92-7.97 (
m, 2H), 8.26 (d, 2H)

IR spectrum (KBr disk, cm-1): 2920, 2820, 1748, 1605, 1510,
1420, 1300, 1260, 1180, 1014,
1070, 890,756 mass spectrum (FAB method, m/e (relative intensity)): 643 (13, MH +), 322 (100) Phase transition temperature (DSC, polarizing microscope observation, ° C.): In the following formula, Cry represents a crystalline phase, SmCA* represents a chiral smectic CA phase, SmA represents a smectic A phase, and lso represents an isotropic phase.

[0041]

[C5]

[Example 2] After applying polyimide to two glass substrates on which transparent electrodes were formed, the Example A liquid crystal device was prepared by injecting the compound obtained in 1 and sandwiching it between two orthogonal polarizing plates. When the optical response speed of this material was measured by applying a voltage of ±60 V at 20° C., a very fast response time of 50 μsec was obtained.

Claims (2)

[Claims] [Claim 1] An optically active compound represented by the following general formula (1). embedded image [However, in the above general formula (1), R1 represents an alkyl group having 4 to 16 carbon atoms, R2 represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ] 2. A display element characterized by using an optically active compound represented by the following general formula (1). embedded image [However, in the above general formula (1), R1 represents an alkyl group having 4 to 16 carbon atoms, R2 represents an alkyl group having 4 to 12 carbon atoms, and * represents optical activity. ]