JPH01265060A - Liquid crystal material - Google Patents

Abstract

NEW MATERIAL:A compound having 1,2 diarylethane skeleton expressed by formula I (R is 5-15C alkyl; * is asymmetric carbon). EXAMPLE:1-[4'-(p-2-Octyloxyphenyl)oxycarbonylphenyl]-2-(4''-alkox-yphe nyl) ethane. USE:A liquid crystal material exhibiting a chiral smectic carbon phase and having ferroelectric and excellent responsibility of image display, being extremely stable to moisture and light and having wide temperature range of liquid crystal phase. PREPARATION:A compound expressed by formula II is reacted with ethyl acetate in the presence of a palladium-carbon catalyst under ambient temperature to provide the compound expressed by formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a ferroelectric liquid crystal compound useful as a display element with excellent responsiveness for displaying a single image, and a chiral smectic liquid crystal composition containing the same.

Currently, display elements using liquid crystal materials are light-receiving display systems, and have the advantage of low power consumption and the ability to easily produce thin display devices, and are in widespread practical use. On the other hand, the development of light-emitting display systems such as EL (electroluminescence) and plasma displays, which have a faster response time, is also active.

[Conventional technology]

Most of the liquid crystals that have been used for display devices so far have been nematic liquid crystals, the mainstream being TN (twisted nematic).
'11w1sted Nematic) ] type. Although this TN type display system has advantages such as small size and low power consumption, it also has the disadvantage that the response speed for displaying one image is slow. Various attempts have been made to improve this point, but Molecular Crystals & Liquid
Based on the results of verifying the theoretical limits shown in Volume 94, pages 155-165 of Liquid Crystals, Vol. 94, it appears that the development of materials for TN type displays has almost reached its limit.

Therefore, in order to overcome the above-mentioned drawbacks, a lot of attention has been paid to the development of chiral liquid crystals in place of nematic liquid crystals, and in particular, some progress has been made in the field of ferroelectric liquid crystals.

What was the first ferroelectric liquid crystal developed?

C)i3-C)12Cen2)15* (in the formula, * indicates an asymmetric carbon atom)
(hereinafter abbreviated as DOBAMBC), its liquid crystal phase series and phase transition temperature (° C.) are as follows.

(In the formula, C is the crystal phase, SA is the Smekchi-Tsuku A phase, S
C* indicates chiral smectic Cq, Su indicates chiral smectic) i phase, and I indicates isotropic liquid, respectively)
.

Ferroelectricity is expressed in chiral smectic C phase (hereinafter abbreviated as SC) or chiral smectic H phase (hereinafter abbreviated as SH), which are classified and named based on molecular arrangement.9 The response based on ferroelectricity is expressed by the following formula [A]τ =η/PS,E
(A) (where τ is the response time, η is the viscosity of the liquid crystal material, Ps is the spontaneous polarization, and E is the electric field), so it is theoretically possible to obtain a display element that can respond up to 1 μs.・Journal Op Physics France (R, B, Meyer) et al.
Our world of Physics France
) Vol. 36, p. 69 (1975).

[Problem that the invention seeks to solve]

There are compounds shown in Table 1 as typical ferroelectric liquid crystals. However, these compounds undergo isomerization within a short period of time when exposed to light, are unstable to moisture, and lose their liquid crystallinity due to hydrolysis reactions, making them undesirable as materials for display elements.

Recently, ferroelectric liquid crystal compounds shown in Table 2 have been disclosed.

Table 2 In Table 2, R and R' represent an alkyl group, and * represents an asymmetric carbon atom.

These compounds solve the above problems.

Although the value of spontaneous polarization (Ps) is relatively large, the temperature range of the chiral smectic phase exhibiting ferroelectricity is narrow and is not practical.

[Means for solving problems]

The present inventors have conducted intensive research from the above viewpoint.

Discovered a ferroelectric liquid crystal compound with excellent stability and a wide temperature range belonging to the Sc phase or SH phase (and a large Ps value) and a liquid crystal composition containing the same.

We have arrived at the present invention.

That is, 1 the present invention has a 1,2-diarenyl ethane skeleton represented by the general formula [■] (wherein R represents an alkyl group having 5 to 15 carbon atoms, and * represents an asymmetric carbon atom). It is a liquid crystal compound characterized by the following.

The present invention also provides a liquid crystal composition containing at least one compound represented by the general formula CI).

In the general formula CI), the diarynylethane skeleton is named as follows.

Therefore, the compound represented by the above general 2〇) is 1
-C4'-(P-CR or/l'1S)-2-yFrif-
)VyJ-xyphenyl)oxycarponylphenyl//
)-2-(4〃-alkoxypheny#)ethane.

The method for producing the compound represented by the general formula CI) is detailed in Section F, in which a phenol compound having an optically active group is used as one of the raw materials for production.

It can be synthesized by the method described in Open and Close Publication No. 61-22051, and can also be obtained from Teikoku Kagaku Sangyo Co., Ltd.

An outline of the method for producing the compound of the present invention is shown by the following formula.

H3 k-I3 [C] [D] (In the above formula, R is an alkyl group having 5 to 15 carbon atoms, one asymmetric carbon atom, TEA is triethyleneamine, THF
represent tetrahydrofuran, respectively. ) [Function] The compound of the present invention exhibits the following actions and features.

First, in an atmosphere containing moisture, a group that does not have an azomethine group (-N=eh-) that can be easily decomposed and is isomerized by light can exhibit ferroelectricity within a temperature range. Broadly, by mixing the compounds of the present invention with each other, or by mixing the compound of the present invention with existing ferroelectric liquid crystal compounds such as esters, piphenyls, pyrimidines, etc.

Lowering the lower limit of the temperature range that exhibits ferroelectricity to below room temperature I
It is also possible.
1 Furthermore, the Ps (spontaneous polarization) value of the compound of the present invention is 3°nC.
/ctI or more, so when used as a blend material in a mixed system, it is difficult to lower the melting point. As we reach
It is possible to improve the ps value of the mixed system.

[Example of large application]

Examples below? The present invention will be explained by way of example.

In the examples, % indicates weight t%.

Production Example 1 Synthesis of 4-Alkoxyphenylacetylene CB] 4-Alkoxybrombenzene (0.234 mol, 3-methy/L) was placed in a 500 cc three-meter flask equipped with a stirrer, a thermometer, and a reflux condenser in a nitrogen stream. /-1
-Butyn-3-ol 29.57 f (0,352 m
ol ), ) diphenylphosphine 1. OOP, dichlorobis(triphenylphosphine)palladium contact!
0.52 f (0.73 mmol) and triethylamine 200- were charged, stirred and dissolved, and the iodized steel 160
Added 1r9. 3 hours at room temperature... After stirring, gradually heat the
It took 30 minutes to bring the internal temperature to 9°C. 20 at this temperature
Allowed time to react. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, and 300 m/! of ether was added to the residue. In addition, it was washed with water and dried over anhydrous sodium sulfate. After p,
The ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel tV400t+
Developing bath medium: benzene) to obtain a compound of the 9th formula as an intermediate compound.

5114 m of the above intermediate compound was added to a 300-capacity Mitsuro flask equipped with a stirrer, thermometer, and distillation equipment in a nitrogen stream.
120 mol of anhydrous toluene and 310 mol of sodium hydride (60% Nudur dispersant) were charged, and the mixture was stirred at room temperature for 30 minutes. Heat gradually.

Does it take 30 minutes to reach the internal temperature? ! The temperature was 1-70°C. Acetone (a by-product) began to reflux and distill out together with toluene, but the reaction continued with further heating until the distillation temperature reached the boiling point of toluene. During this time, 2 hours were required, and the distilled medium was 60%. After the reaction is complete, return to room temperature and add benzene
oa m/, washed with water, and dried over anhydrous sodium sulfate. After washing, the organic solvent was distilled off.

All silica gel column chromatography (200
The structure of 4-alkoxyphenylacetylene in Table 3 was confirmed using Ik and N1vlRsubek)/V.

The results are shown in Figure 3.

ff Preparation Example 2 P (2-octyloxy)phenyl p-((S)-2-octyloxyphenol (manufactured by Teikoku Kagaku Sangyo Co., Ltd.) was placed in a 100 CC three-way flask equipped with a stirrer, a thermometer, and a reflux condenser. 3.009 (13
, 5 mmol) and anhydrous pyridine 20 were completely dissolved under stirring. To this pyridine solution, 3.26 f (14.9 mmol) of 4-promopenzoyl chloride was added.
20 glasses of tetrahydrofuran solution were added to the water-cooled solution. After the reaction temperature was returned to room temperature, it was brought to reflux temperature and stirred for 8 hours. After the reaction was completed, ether)v was added, followed by washing with water, alkaline washing with 10% caustic soda, and washing with water in this order.

It was dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (20
0 mesh silicage/100F, developing solvent: gradient of hexane to benzene) for isolation and purification, melting point 71.
P-(2-offfyVoxy)pheny/L/-4-bromobenzoate [C] with 4-72,3°C
Obtained with a yield of 8%.

The spectral data of this compound were as follows.

I K: 2932.1728.1 to v K””8
506.1250°1204, 1082.748 (7)
=1DC1s N 1vlK : δ 7.8(Q, 4H
), 6.9 ((1,4)1).

M.S. 4.3 (m, 1) 1).

1.8 to 0.7 (m, 16) 1) P-(2-octyloxy) obtained in Production Example 2 in a nitrogen stream to a three-part flask equipped with a ppm stirrer, thermometer and reflux condenser.
Phenyl/L/-4-glomobenzoe) 5 m mo
l, 5.5 mmol of 4-alkoxyphenylacetylene obtained in Production Example 1, ) liphenylphosphine l QQ mmol, dichlorobis(triphenylphosphine)palladium catalyst 60 and triethylamine 60 - all charged, stirred and dissolved, Copper iodide 6my'
fr: Added. After stirring at room temperature for 2 hours, the mixture was gradually heated.

It took 30 minutes to bring the internal sound to 70°C. The reaction was allowed to proceed at this temperature for 8 hours. After the reaction, the temperature was returned to room temperature, triethylamine was distilled off under reduced pressure, and 100 ml of ether was added to the residue, which was washed with water and dried over anhydrous sodium sulfate.

After evaporation, the ether was distilled off, and the residue was subjected to silica gel column chromatography (200 mesh silica gel/l/l).
100y, khJ solvent benzene:hexane=1
:1) and isolated and purified. Tan crystallization from hexane L
-(4-(p-2-octyloxypheny/L/)oxycarbony/L/4/-alkoxytran [1)
) t-obtained in a yield of 81 to 94%. The sensitivity of each compound was confirmed using fR and N1vtR spectrum data.

Example, [NQ, 5) Yield 88% KBr dIIIk I R: v 2920.2216.173
6.124a762crn DC4s NyiR: a 8.2~6.8 (m; 1
2H), 4.3 (m, IH) + MS 4.0 (L, 2)i).

2.0-0.6 (m, 38-40H) ppm The results are shown in Table 4 along with the phase transition temperature of each compound obtained.

Example 1 1-(4'-(p-2-octyloxyphene) In a flask equipped with a stirrer, a thermometer, a reflux condenser, and a rubber gas can containing hydrogen gas, m&4 in Example 3 was added. -(P
-2-octyloxypheny)V)oxycarbo=
) v -4'-7) v-1 oxytrough 4.4 mmo
l, 5 qb palladium-carbon catalyst soo mq
and ethyl acetate/L/10tnI! I prepared it in. After replacing with hydrogen gas, the reaction was carried out at room temperature.

The extent of reaction progress was examined using a purple thin layer chromatography chip.

The reaction was almost completed in about 6 hours, but stirring was continued for 14 hours in a hydrogen atmosphere. After the reaction, the glass filter catalyst covered with dicalide was removed, and the ethyl acetate was removed under reduced pressure [
Distilled away. The reaction crude product was subjected to silica gel column chromatography (200 mesh silica gel/l'5 (11
Developing solvent: benzene/hexane = 1/1) for purification. Yield was 84-93%. The structure of each compound was confirmed using IR and NIViR Nuvector.

Example, [Compound Nagi 5] Yield 84% KBr disk IR: ν 2920.1,732.1510.
1196°814crn-'1'JMR2 II 0D0L3 8.1~6.
7(m, 12H), 4.3(m, 11().

M.S. 3.9 (t, 2) 1), 2°9 (s, 4H).

2.0 to 0.6 (m, 38 to 40 H) pPm is shown in Table 5 along with the phase transition temperature of each compound.

Example 2 Compound No. 3 in Table 5. All the liquid crystal compositions shown in Table 6 below were prepared using the liquid crystal compounds of the present invention No. 4 and No. 5, and all the phase transition temperatures were measured. Rarely.

Table 6 When this liquid crystal composition was applied with a polyimide film and subjected to parallel alignment treatment by lahinking the 9 surface, and injected into a cell having a transparent electrode with a cell thickness controlled to 2 μm, a cell with uniform alignment at Sc was obtained. was gotten. Also, at a temperature of 70℃±I
When the full OV square wave voltage is applied, the response time is 0.39m!
+, a display element with a contrast of 10 was obtained.

Example 3 A liquid crystal composition consisting of 80% of the liquid crystal composition of Example 2 and 20% of a compound represented by the following structural formula was prepared, and its phase transition temperature ff' was measured. It was ri.

When this liquid crystal composition was injected into a cell similar to the cell used in Example 2, a cell with uniform orientation could be obtained at Sc. Response time of this cell at 30°C: 1.1 ms
, the contrast was 13. In addition to ester materials, it was also possible to lower the melting point and expand the temperature range of Sc by mixing with biphenyl-based or pyrimidine-based liquid crystal compounds.

〔Effect of the invention〕

As shown in Example 1 above, one compound of the present invention is Sc
It is a compound that exhibits a phase and has two ferroelectric properties, and from the results of Examples 2 and 3, it is an effective component in obtaining a chiral smeknac liquid crystal composition over a wide temperature range including room temperature. it is obvious. Such effects are achieved for the first time by the present invention.

Claims (2)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] 1 represented by (in the formula, R represents an alkyl group having 5 to 15 carbon atoms, and * represents an asymmetric carbon atom) , 2-diarenylethane skeleton. (2) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, R represents an alkyl group having 5 to 15 carbon atoms, and * represents an asymmetric carbon atom) 1 , a liquid crystal composition comprising at least one liquid crystal compound having a 2-diarenyl ethane skeleton.