JPH0517403A - Liquid crystalline compound and ferroelectric liquid crystalline composition - Google Patents

Abstract

PURPOSE:To provide new liquid crystalline compounds containing an N phase capable of giving excellent orientation properties by itself in a state of a relatively low viscosity and spontaneous polarization, responsible at a high speed and most suitable for a ferroelectric liquid crystalline composition. CONSTITUTION:Liquid crystalline compounds of formula I (A<1> and A<2> are cyclohexane ring or benzene ring, provided that one or both of A<1> and A<2> are cyclohexane ring; A<3>-A<5> are benzene ring, naphthalene ring, heterocycle or alicycle; R<1> is H, alkyl or alkoxy; R<2> is H, alkyl, alkoxy, F, Cl, Br or cyano; (m) and (h) are 0 or 1), e.g. 2-[4-(trans-4-pentylcyclohexyl)phenyloxy]acetic acid-4-(5- octylpyrimidin-2-yl) phenyl ester. The compounds of formula I can be obtained) e.g. by reacting a compound of formula II with a halogenoacetic acid ester of formula III (R<7> is alkyl), hydrolyzing the resultant compounds of formula IV, then halogenating the resultant compound of formula V and subsequently reacting a compound of formula VI therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystal compound, and more particularly to a ferroelectric liquid crystal composition containing the liquid crystal compound suitable for large area, high density and high speed display.

[0002]

2. Description of the Related Art As a display system of a liquid crystal display device, a DAP
(Arranged phase deformation) type, guest / host type, TN (twisted nematic) type, STN (super twisted nematic)
Type, SBE (super-birefringence effect) type, cholesteric-nematic phase transition type and the like, some of which are currently in practical use. However, it includes some problems, and improvement of a particularly slow response speed is desired. For example, a twisted nematic (TN) type can be mentioned as a typical one which is widely put into practical use at present. The TN type uses a nematic liquid crystal phase and has problems such as a slow response speed and poor viewing angle characteristics when used for a display, as compared with a display system such as a CRT (Cathode Ray Tube). Therefore, the display has been limited to a limited number of uses.

Recently, surface-stabilized ferroelectric liquid crystal devices have been developed by Clark and Lagerwall (Japanese Patent Laid-Open No. 56-56).
107216, US Pat. No. 4,367,924, etc.). In this device, a ferroelectric liquid crystal sandwiched between substrates with a gap of about 2 μm combined with a polarizing plate controls the amount of transmitted light by changing the orientation of the molecular long axis according to the polarity of the applied electric field. It is characterized by high-speed response and bistability.
Moreover, because of its excellent viewing angle characteristics, this device is expected to be widely used as a large-capacity, high-density display device, and the development of a device with faster response and high bistability becomes an urgent task. ing.

The ferroelectric liquid crystal has a chiral smectic C (hereinafter abbreviated as Sc ^* ) phase as one of the liquid crystal phases. To use ferroelectric liquid crystal as a display element, a wide Sc ^* phase (expandable temperature range)
It is required to have many characteristics, such as having a high speed, having a high speed response, and having a good alignment property (the liquid crystal having an N phase is involved). However, no single compound satisfies these requirements, and a liquid crystal composition in which several compounds are mixed is used for a display device. As a method for preparing such a composition, for example, a liquid crystal compound or a liquid crystal mixture (hereinafter, referred to as a base liquid crystal) that exhibits a smectic C (hereinafter, abbreviated as Sc) phase that does not exhibit ferroelectricity and an optically active compound is added. The method of addition is known (Mol. Cryst. Li
Q. Cryst., 89, 327 (1982)). Here, as the component of the base liquid crystal exhibiting the Sc phase, a liquid crystal compound such as phenylbenzoate type, Schiff base type, biphenyl type, phenylpyrimidine type, phenylpyridine type liquid crystal is used. Further, for example, 5-alkyl-2- (4-alkoxyphenyl) pyrimidine which is a non-chiral phenylpyrimidine liquid crystal (Japanese Patent Laid-Open No. 61-291679).
Or 5-alkoxy-2- (4-alkylphenyl) pyrimidine (JP-A-62-137883, JP-A-2).
No. 173089) has been proposed as a liquid crystal display device. Further, generally, regarding the oxyacetic acid ester having a tricyclic structure which easily gives the N phase, JP-A-61-5052, JP-A-61-40271, JP-A-63-135346, and International Application WO-
87/05012 describes the use as a liquid crystalline compound.

A liquid crystal composition satisfying the characteristics required for the display device, that is, having good orientation, Sc ^* phase in a wide temperature range, and high-speed response, satisfies the above-mentioned composition. However, these necessarily have a complicated composition. That is, it is generally necessary to mix various types of liquid crystals having an N phase while balancing other physical properties in order to impart good orientation.
Generally, the composition is complicated. Nevertheless, a ferroelectric liquid crystal composition showing a satisfactory orientation has not been obtained.

[0006]

The inventors of the present invention have made further studies to solve the above-mentioned problems, and found that the N-phase which can impart good orientation alone with relatively small viscosity and spontaneous polarization. A liquid crystal compound having By using this while using a non-chiral compound having no N phase while suppressing the viscosity of the liquid crystal composition to a low level, a ferroelectric liquid crystal composition that is capable of high-speed response and exhibits good orientation is obtained. I found that.

Accordingly, the present invention exhibits good orientation,
In particular, it is an object to provide a liquid crystal compound which is useful as a liquid crystal composition for liquid crystal display devices. Another object of the present invention is to provide a ferroelectric liquid crystal composition that exhibits good orientation and is excellent in high-speed response, and is particularly useful as a liquid crystal composition for liquid crystal display devices. Another object of the present invention is to provide a ferroelectric liquid crystal composition which exhibits good orientation, is excellent in high-speed response, and is useful as a liquid crystal composition for a liquid crystal display device having a relatively simple composition. To do.

[0008]

The above object is achieved by the following general formula (I):

[0009]

[Chemical 4]

[Wherein A ¹ and A ² represent a cyclohexane ring or a benzene ring, and A ¹ and A ²
At least one of them is a cyclohexane ring, and A ³ , A
⁴ and A ⁵ represent a benzene ring, a naphthalene ring, a hetero ring or an aliphatic ring, which may be the same or different from each other, R ¹ represents a hydrogen atom, an alkyl group or an alkoxy group, and R ² represents hydrogen. Represents an atom, an alkyl group, an alkoxy group, a fluorine atom, a chlorine atom, a bromine atom or a cyano group, and m and n represent 0 or 1. ] A liquid crystal compound represented by

The present invention can also be achieved by a ferroelectric liquid crystal composition containing a liquid crystal compound represented by the above general formula (I) and a chiral compound.

Preferred embodiments of the present invention are as follows. 1) The ferroelectric liquid crystal composition is a non-chiral compound,
Furthermore, the following general formula (II):

[0013]

[Chemical 5]

[Wherein B ¹ and B ² represent a benzene ring or a heterocycle and are different from each other, and R ³ and R ⁴ represent an alkyl group or an alkoxy group. ] The above-mentioned ferroelectric liquid crystal composition containing a liquid crystal compound represented by the following.

2) a liquid crystalline compound represented by the above general formula (I), a liquid crystalline compound represented by the above general formula (II),
And the composition ratio of the composition comprising the chiral compound,
5 to 80:10 to 90: 2 to 40 (liquid crystal compound of general formula (I): liquid crystal compound of general formula (II): chiral compound), the ferroelectric liquid crystal composition of 1) above.

3) The ratio of the liquid crystal compound represented by the general formula (I) to the liquid crystal compound represented by the general formula (II) is 20:80 to 80:20 (general formula (I): general). The ferroelectric liquid crystal composition according to 1) above, which is in the range of formula (II)).

4) B ¹ and B in the general formula (II)
² represents a benzene ring or a hetero ring (a pyridine ring or a pyrimidine ring), which are different from each other, and the ferroelectric liquid crystal composition according to 1) above.

5) In the general formula (II), R ³ and R ^3
4 represents an alkyl group, which is the ferroelectric liquid crystal composition according to 1) above.

6) 40 non-chiral compounds in the composition
The ferroelectric liquid crystal composition as described above, characterized by containing at least wt%.

7) R ¹ and R ² of the non-chiral compound represented by the above general formula (I) each have 1 carbon atom.
The above ferroelectric liquid crystal composition, which is an alkyl group having 5 or less.

8) R ³ and R ⁴ of the non-chiral compound represented by the above general formula (II) each have 3 carbon atoms.
18. The ferroelectric liquid crystal composition as described above, wherein the ferroelectric liquid crystal composition is an alkyl group or an alkoxy group.

[Detailed Description of the Invention] The liquid crystal composition of the present invention contains the liquid crystal compound of the above-mentioned general formula (I) which is excellent in orientation imparting property. Further, the ferroelectric liquid crystal composition of the present invention,
When the above compound is contained as a non-chiral compound and an element is formed using this composition, excellent orientation and high-speed response can be imparted to the element.

The liquid crystalline compound (non-chiral compound) of the present invention has the following general formula (I):

[0024]

[Chemical 6]

[Wherein A ¹ and A ² represent a cyclohexane ring or a benzene ring, and A ¹ and A ²
At least one of them is a cyclohexane ring, and A ³ , A
⁴ and A ⁵ represent a benzene ring, a naphthalene ring, a hetero ring or an aliphatic ring, which may be the same or different from each other, R ¹ represents a hydrogen atom, an alkyl group or an alkoxy group, and R ² represents hydrogen. Represents an atom, an alkyl group, an alkoxy group, a fluorine atom, a chlorine atom, a bromine atom or a cyano group, and m and n represent 0 or 1, and at least one of m and n is 1. ]] Is represented.

The rings represented by A ¹ , A ² , A ³ , A ⁴ and A ⁵ may have any substituent. Preferred specific examples of the substituent include an alkyl group and an alkoxy group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a hydroxyl group, an oxy group and an alkenyl group having 2 to 6 carbon atoms. Further, a fluorine atom and a cyano group are preferable.

Preferred examples of the heterocycle represented by A ³ , A ⁴ and A ⁵ include pyridine, pyrimidine, pyridazine, pyrrole, oxazolidine, piperidine, dioxane, furan, thiophene, thiazole, thiadiazole, pyran, pyrazine, triazine, Examples thereof include tetrazine, benzoxazole, benzothiazole, diazaazulenin, coumarin, quinoline, benzoxazine, tetrahydroquinazoline and quinoxaline. Furthermore, pyridine and pyrimidine are preferred. A
Preferred examples of the aliphatic ring represented by ³ , A ⁴ and A ⁵ include cycloalkane and cycloalkene having 5 to 12 carbon atoms, and cyclohexane is more preferable. Further, it may be a compound in which a benzene ring and an aliphatic ring are condensed, such as fluorene or phenanthrene. In particular, when the above compound is used as a component of a non-chiral compound of a ferroelectric liquid crystal composition, A ³ is a benzene ring, A ⁴ is a pyrimidine ring, n is 0 and A ⁵ is A ^5.
Is preferably absent.

As for m and n, at least one of m and n is preferably 1. That is, the liquid crystalline compound of the present invention preferably has 4 rings.

The alkyl group or alkoxy group represented by R ¹ and R ² is preferably a linear or branched alkyl group or alkoxy group having 1 to 20 carbon atoms, which may be unsubstituted or substituted. One or more fluorine atoms may be substituted. The CH ₂ group of this group is
It may be substituted with O or S.

R ¹ is preferably a linear or branched alkyl group having 5 to 12 carbon atoms, and R ² is
Further, it is preferably a linear or branched alkyl group or alkoxy group having 1 to 12 carbon atoms, a fluorine atom or a cyano group. When used in a ferroelectric liquid crystal composition, the number of carbon atoms in R ¹ and R ² is preferably 15 or less, more preferably 10 or less.

The compound of the present invention can be synthesized, for example, by the following method.

[0032]

[Chemical 7]

First, compound (1) is reacted with a halogenated acetic acid ester (R ⁷ represents an alkyl group) to give compound (2), which is then hydrolyzed to obtain compound (3). Then, the compound (3) is halogenated and reacted with the compound (4) to obtain the compound (5) of the present invention.

Examples of the liquid crystalline compound represented by the general formula (I) of the present invention include the compounds shown below.

2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4
-(5-octylpyrimidin-2-yl) phenyl ester 2- {4- (trans-4-octylcyclohexyl)
Phenyloxy} acetic acid-4- (5-octylpyrimidin-2-yl) phenyl ester 2- {4- (trans-4-hexylcyclohexyl)
Phenyloxy} acetic acid-4- (5-hexylpyrimidin-2-yl) phenyl ester

2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-2
-(4-heptylphenyl) pyrimidin-5-yl ester 2- {4- (trans-4-octylcyclohexylhexyl) phenyloxy} acetic acid-2-
(4-heptylphenyl) pyrimidin-5-yl ester 2- {4- (trans-4-pentylcyclohexyl)
Phenyloxy} acetic acid-2- (4-octylphenyl) pyrimidin-5-yl ester

2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4
-{5- (7-Methyl) octylpyrimidin-2-yl} phenyl ester 2- {4- (trans-4-octylcyclohexyl)
Phenyloxy} acetic acid-4- {5- (7
-Methyl) octylpyrimidin-2-yl} phenyl ester

2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic azide-4
-{2- (4-heptylphenyl) pyridin-5-yl} phenyl ester 2- {trans-4- (trans-4-pentylcyclohexyl) cyclohexyloxy} acetic acid-4- (5-octylpyrimidine-2- Yl) phenyl ester 2- {trans-4- (4-pentylphenyl) cyclohexyloxy} acetic acid-4- (5-octylpyrimidin-2-yl) phenyl ester

Regarding the oxyacetic acid ester as described above, JP-A-61-5052 and JP-A-61-402.
No. 71, JP-A-63-135346, and International Application WO-87 / 05012 describe use as a liquid crystalline compound. The liquid crystalline compound represented by the general formula (I) of the oxyacetic acid ester of the present invention is not described in the above three domestic publications, but is represented by the general formula shown in International Application WO-87 / 05012. Is included. However, the oxyacetic acid ester compound of the present invention is not specifically described. The above general formula (I)
Since the liquid crystal compound represented by has an N phase and exhibits a Sc phase at a high temperature (about 60 ° C. or higher), when used in a ferroelectric liquid crystal composition, the liquid crystal compound has good orientation and is used as a liquid crystal element. The effect that the operating temperature range is widened is also obtained. When the liquid crystalline compound represented by the above general formula (I) (having an N phase) is used as the non-chiral compound of the ferroelectric liquid crystal composition, it is used together with the following general formula (II):

[0040]

[Chemical 8]

[Wherein B ¹ and B ² represent a benzene ring or a heterocycle and are different from each other, and R ³ and R ⁴ represent an alkyl group or an alkoxy group. ] It is preferable to use the liquid crystalline compound represented by the formula as a non-chiral compound. The liquid crystal compound,
It has no N phase and has a viscosity decreasing effect. Then, a chiral compound is further used to obtain a ferroelectric liquid crystal composition.

In the general formula (II), B ¹ and B ²
Represents a benzene ring or a hetero ring (a pyridine ring or a pyrimidine ring), and preferably different from each other.

In the general formula (II), R ³ and R
It is preferable that ⁴ is an alkyl group because the effect of lowering the viscosity can be easily obtained. That is, since the compound of the general formula (I) of the present invention can impart the orientation of the composition by itself unlike the conventional compound, a good orientation can be obtained even when mixed with the compound of the general formula (II). It is possible to impart sex. Therefore, there is an advantage that the design of the ferroelectric liquid crystal composition becomes easy. Further, R ³ and R ⁴ in the general formula (II) are preferably an alkyl group having 3 to 18 carbon atoms, and particularly 5 to 13
Is preferred. The compounds of general formula (II), I _SO ← →
Those that undergo S _A ← → S _C transition are preferable.

The composition ratio of the liquid crystal (non-chiral) compound represented by the general formula (I), the liquid crystal (non-chiral) compound represented by the general formula (II), and the chiral compound is 5 to 80:10. 90: 2-40 (liquid crystal compound of general formula (I): liquid crystal compound of general formula (II):
It is preferably a chiral compound). Furthermore, 10
The range of -80: 10 to 70: 2-40 is preferable.

Further, it is preferable that the ferroelectric liquid crystal composition contains a non-chiral compound in an amount of 40% by weight or more.

Specific examples of the above general formula (II) include the following compounds. 5- (6-methylheptyl) -2- (heptylphenyl) pyrimidine 5- (7-methyloctyl) -2- (heptylphenyl) pyrimidine 5- (8-methylnonyl) -2- (heptylphenyl)
Pyrimidine 5- (7-methyloctyl) -2- (octylphenyl) pyrimidine 5- (8-methylnonyl) -2- (octylphenyl)
Pyrimidine 5- (9-methyldecyl) -2- (octylphenyl)
Pyrimidine 5- (8-methylnonyl) -2- (nonylphenyl) pyrimidine 5- (9-methyldecyl) -2- (nonylphenyl) pyrimidine 5- (10-methylundecyl) -2- (nonylphenyl) pyrimidine 5- (9-Methyldecyl) -2- (decylphenyl) pyrimidine 5- (10-methylundecyl) -2- (decylphenyl) pyrimidine 5- (11-methyldodecyl) -2- (decylphenyl) pyrimidine

5-octyl-2- (4- (6-methylheptyl) phenyl) pyrimidine 5-nonyl-2- (4- (7-methyloctyl) phenyl) pyrimidine 5-decyl-2- (4- (7 -Methyloctyl) phenyl) pyrimidine 5-nonyl-2- (4- (8-methylnonyl) phenyl) pyrimidine 5-decyl-2- (4- (8-methylnonyl) phenyl) pyrimidine 5-undecyl-2- (4- (8-Methylnonyl) phenyl) pyrimidine 5-decyl-2- (4- (9-methyldecyl) phenyl) pyrimidine 5-undecyl-2- (4- (9-methyldecyl) phenyl) pyrimidine 5-dodecyl-2- (4 -(9-Methyldecyl) phenyl) pyrimidine

5- (7-methyloctyl) -2- (4-
(6-Methylheptyl) phenyl) pyrimidine 5- (8-methylnonyl) -2- (4- (7-methyloctyl) phenyl) pyrimidine 5- (9-methyldecyl) -2- (4- (7-methyloctyl) Phenyl) pyrimidine 5- (9-methyldecyl) -2- (4- (8-methylnonyl) phenyl) pyrimidine 5- (10-methylundecyl) -2- (4- (8-methylnonyl) phenyl) pyrimidine 5- ( 9-Methyldecyl) -2- (4- (9-methyldecyl) phenyl) pyrimidine 5- (10-methylundecyl) -2- (4- (9-methyldecyl) phenyl) pyrimidine 5- (11-methyldodecyl)- 2- (4- (9-methyldecyl) phenyl) pyrimidine

5-nonyl-2- (4-octylphenyl) pyrimidine 5-nonyl-2- (4-nonylphenyl) pyrimidine 5-decyl-2- (4-octylphenyl) pyrimidine 5-octyl-2- ( 4-octylphenyl) pyrimidine 5-undecyl-2- (4-octylphenyl) pyrimidine 5-dodecyl-2- (4-octylphenyl) pyrimidine 5-tridecyl-2- (4-octylphenyl) pyrimidine 5-decyl-2 -(4-nonylphenyl) pyrimidine 5-undecyl-2- (4-nonylphenyl) pyrimidine 5-dodecyl-2- (4-nonylphenyl) pyrimidine 5-tridecyl-2- (4-nonylphenyl) pyrimidine 5-tetradecyl -2- (4-nonylphenyl) pyrimidine 5-octyl-2- (4-decylphenyi ) Pyrimidine 5-decyl-2- (4-decylphenyl) pyrimidine 5-undecyl-2- (4-decylphenyl) pyrimidine 5-dodecyl-2- (4-decylphenyl) pyrimidine 5-tridecyl-2- (4- Decylphenyl) pyrimidine 5-octyl-2- (4-undecylphenyl) pyrimidine 5-decyl-2- (4-undecylphenyl) pyrimidine 5-undecyl-2- (4-undecylphenyl) pyrimidine 5-dodecyl- 2- (4-undecylphenyl) pyrimidine 5-pentadecyl-2- (4-undecylphenyl) pyrimidine 5-nonyl-2- (4-dodecylphenyl) pyrimidine 5-decyl-2- (4-dodecylphenyl) pyrimidine 5-Undecyl-2- (4-dodecylphenyl) pyrimidine 5-tridecyl-2- ( -Dodecylphenyl) pyrimidine 5-nonyl-2- (4-tridecylphenyl) pyrimidine 5-dodecyl-2- (4-tridecylphenyl) pyrimidine 5-tridecyl-2- (4-tridecylphenyl) pyrimidine 5-pentadecyl 2- (4-Tridecylphenyl) pyrimidine 5-nonyl-2- (4-tetradecylphenyl) pyrimidine 5-undecyl-2- (4-tetradecylphenyl) pyrimidine 5-dodecyl-2- (4-tetradecyl Phenyl) pyrimidine 5-pentadecyl-2- (4-tetradecylphenyl)
Pyrimidine 5-decyl-2- (4-pentadecylphenyl) pyrimidine 5-undecyl-2- (4-pentadecylphenyl) pyrimidine 5-dodecyl-2- (4-pentadecylphenyl) pyrimidine 5-tridecyl-2- ( 4-pentadecylphenyl) pyrimidine

5-nonyloxy-2- (4-heptylphenyl) pyrimidine 5-octyl-2- (4-octyloxyphenyl) pyrimidine 5-nonyl-2- (4-octyloxyphenyl) pyrimidine 5-heptyl-2- (4-nonyloxyphenyl) pyrimidine 5-heptyl-2- (4-heptyloxyphenyl) pyridine 5-heptyl-2- (4-octyloxyphenyl) pyridine 5-heptyl-2- (4-nonyloxyphenyl) pyridine 5-heptyl-2- (3-fluoro-4-octyloxyphenyl) pyridine 5-decyl-2-(-4-decanoyloxyphenyl)
Pyrimidine

In addition to the compounds of the above general formula (I) and general formula (II), other non-chiral compounds may be used, for example, the following compounds can be mentioned. 5-hexyl-2- (4-pentylbiphenylyl-4 '
-) Pyrimidine 5-heptyl-2- (4-pentylbiphenylyl-4 '
-) Pyrimidine 5-octyl-2- (4-heptylbiphenylyl-4 '
-) Pyrimidine 5- (4-heptyloxyphenylyl) -2- (4-heptylphenyl) pyridine 4-octyloxyphenyl-4'-decyloxybenzoate 4-octyloxyphenyl-4'-decylbenzoate 4-hexyloxy Phenyl-4'-decylbenzoate

As the chiral compound of the present invention, a conventional optically active compound can be used, and it is not particularly limited, but examples thereof include the following compounds. 5-octyl-2- [4-((2S) -2-fluorooctyloxy) phenyl] pyrimidine 5-[(2S) -2-((2S) -2-propyloxy-propanoyloxy) -propyloxy] -2- (4
-Octyloxyphenyl] pyrimidine 5-[(2S) -2-((2S) -2-propyloxy-propanoyloxy) -propyloxy] -2- (4
-Heptylbiphenyl] pyrimidine 5-((2S) -2-methylbutyl) -2- (4-heptylbiphenyl) pyrimidine

The ferroelectric liquid crystal composition of the present invention can be prepared by a method similar to the method used for producing a conventional ferroelectric liquid crystal composition except that the above components are used.

Further, the liquid crystal compound and the ferroelectric liquid crystal composition of the present invention are used as a liquid crystal material for liquid crystal display devices of various modes in a wide range in the same manner as the conventional liquid crystal compound and the ferroelectric liquid crystal composition. It is possible to manufacture a liquid crystal display device having excellent orientation and high-speed response.

[0055]

EXAMPLES The present invention will be described below with reference to examples. However, the invention is not limited by the following examples.

[Example 1] 2- {4- (trans-4-
Pentylcyclohexyl) phenyloxy} acetic acid-4- (5-octylpyrimidin-2-yl)
Phenyl ester

1) Synthesis of 2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid 12 g of 4- (trans-4-pentylcyclohexyl) phenol, 60 ml of N, N-dimethylformamide,
While stirring 13.8 g of potassium carbonate at 80 ° C, 11 g of ethyl prom acetate was added dropwise over 30 minutes. After stirring at 80 ° C. for 30 minutes, 100 ml of ethyl acetate and 100 ml of water were added to extract the ethyl acetate layer. After concentrating the ethyl acetate layer, 300 ml of methanol and 50 ml of 20% sodium hydroxide were added, and the mixture was stirred at 50 ° C. for 1 hour. After cooling 10
% To pH 3 with hydrochloric acid, the precipitated precipitate was filtered, washed with water, and dried at 50 ° C. to obtain the desired 2- {4- (trans-4.
12 g of -pentylsilkylhexyl) phenyloxy} acetic acid was obtained.

2) 2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4- (5-octylpyrimidine-
Synthesis of 2-yl) phenyl ester 2- {4- (trans-4-pentylcyclohexyl)
Phenyloxy} acetic acid 2.5 g, thionyl chloride 10 g and N, N-dimethylformamide 0.1
ml was stirred at 50 ° C. for 30 minutes. After the thionyl chloride was distilled off under reduced pressure and concentrated, 2.1 g of 4- (5-octylpyrimidin-2-yl) phenol and 15 g of acetonyl were obtained.
ml and 0.8 ml of pyridine at 10-15 ° C. After stirring for 30 minutes, the deposited precipitate was filtered and washed with water and acetonitrile. The obtained crystals were purified by column chromatography on silica gel using ethyl acetate and n-hexane as a developing solvent, and then recrystallized from ethanol to give 2- {4
1.5 g of-(trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4- (5-octylpyrimidin-2-yl) phenyl ester was obtained.

This compound had a liquid crystal phase, and its phase transition temperature (° C.) was as follows.

[Example 2] The phase transition temperature (° C) of the compound synthesized according to Example 1 is described below. 2- {4- (trans-4-pentylcyclohexyl)
Phenyloxy} acetic acid-2- (4-heptylphenyl) pyrimidin-5-yl ester 2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4- (trans-4-pentylcyclohexyl) phenyl ester 2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4-octylphenyl ester 2- (4-trans-cyclohexylphenyloxy) acetic acid-4-trans-cyclohexylphenyl ester

Example 3 (1) 2- {4- (trans-4-pentylcyclohexyl) phenyloxy} acetic acid-4-of Example 1 which is a compound of the present invention.
16% by weight of (5-octylpyrimidin-2-yl) phenyl ester, 32% by weight of (2) 5-nonyl-2- (4-octyloxyphenyl) pyrimidine, and (7) 5-
32% by weight of nonyloxy-2- (4-heptylphenyl) pyrimidine and (4) 5-octyl-2- [4- (2
20% by weight of S) -2-fluorooctyloxy) phenyl] pyrimyhin was prepared by mixing the respective components with each other to form a ferroelectric liquid crystal composition shown in Table 1 below.

[0062]

[Table 1]

The above ferroelectric liquid crystal composition was sandwiched between two glass plates and the phase texture pattern was observed by a polarization microscope. As a result, the phase transition temperature was confirmed as follows. S _C ^* ← → S _A : 62.8 ℃ S _A ← → N ^* : 73.8 ℃ N ^* ← → Iso: 77.7 ℃

Next, this liquid crystal composition was subjected to parallel alignment treatment by applying polyimide as an alignment film and rubbing the surface thereof, and a thickness of 2 μm provided with a transparent glass electrode.
The liquid crystal element was injected into a m-cell and slowly cooled to be oriented to form a liquid crystal element, which was sandwiched between two orthogonal polarizing plates, and ± 5 V, 50 Hz.
When the rectangular wave of is transmitted, the transmitted light intensity is from 0% to 9%.
The time required to change to 0% (response time τ) was measured. As a result, τ at 25 ° C is 112.6 µsec.
Met.

The rotational viscosity coefficient (η) of this liquid crystal at 25 ° C., obtained from the half width of the polarization reversal current when a rectangular wave was applied, was 318 mPas. Also, the spontaneous polarization Ps obtained from the area of the peak of the polarization reversal current when a triangular wave is applied
Was 35.3 nCcm ^-2 .

Furthermore, the tilt angle θ obtained by examining the movement angle (2θ) of the extinction position when a direct current of 100 V was applied and its polarity was inverted was 26.8 ° at 25 ° C.

The ferroelectric liquid crystal composition of the present invention comprises (1) 2- {4- (trans-4-benzylcyclohexyl) phenyloxy} acetic acid-4- (5) as the non-chiral compound having an N phase. -Octylpyrimidine-2
-Yl) only phenyl ester was used,
It can be seen that since the composition has the N phase, the orientation is excellent and the response speed is at a practically sufficient level.

Example 4 In place of the liquid crystal composition used in Example 3, one more chiral component was added, and two kinds of non-chiral components were changed to other non-chiral components. A ferroelectric liquid crystal composition was prepared.

[0069]

[Table 2]

The phase transition, response time at 25 ° C., rotational viscosity coefficient, spontaneous polarization and tilt angle were measured in the same manner as in Example 3 except that the above composition was used. Got the value. S _C ^* ← → S _A : 61.9 to 63.2 ° C. S _A ← → N ^* : 77.2 ° C. N ^* ← → Iso: 85.2 ° C. τ = 244 μs, η = 245 mPas, Ps = 9.0 nCcm ⁻² , θ = 22.9. °

The ferroelectric liquid crystal composition of the present invention has an N phase as a composition, although (3) which does not have an N phase is used in a large amount of about 50% by weight. Therefore, it can be seen that the orientation is excellent and the response speed is at a practically sufficient level. Further, (3) has a low viscosity, and by combining it with the compound of the present invention, the composition can have a low viscosity and can obtain good characteristics such as the above-mentioned fast response speed.

Example 5 A table in which the liquid crystal composition used in Example 3 was replaced with the non-chiral compound (6) having the non-chiral compound (2) having no N phase, and the compounding amount was changed. A ferroelectric liquid crystal composition having the composition shown in 3 was prepared.

[0073]

[Table 3]

The phase transition, response time at 25 ° C., rotational viscosity coefficient, spontaneous polarization and tilt angle were measured in the same manner as in Example 3 except that the above composition was used. Got the value. S _C ^* ← → S _A : 56.7 ℃ S _A ← → N ^* : 72.1 ℃ N ^* ← → Iso: 74.0 ℃ τ = 82 μs, η = 260 mPas, Ps = 32.0 nCcm ⁻² , θ = 24.5 °

To provide the N phase, it is general to use a compound having a tricyclic structure in an amount of about 20% by weight or more. In the ferroelectric liquid crystal composition of the present invention, the non-chiral compound is N.
As a compound having a tricyclic structure, only (1) has only 11
Only used in weight percent. Nevertheless, since the composition has an N phase, the orientation is excellent and the response speed is at a practically sufficient level.

[Comparative Example 1] A ferroelectric liquid crystal composition having the composition shown in Table 4 was prepared without using the non-chiral compound (1) in place of the liquid crystal composition used in Example 5.

[0077]

[Table 4]

Then, the phase transition, response time at 25 ° C., rotational viscosity coefficient, spontaneous polarization and tilt angle were measured in the same manner as in Example 3 except that the above composition was used. Got the value. S _C ^* ← → S _A : 55.7 ℃ S _A ← → Iso: 74.0 ℃ τ = 51 μs, η = 247 mPas, Ps = 34.0 nCcm ⁻² , θ = 20.7 °

Since the above-mentioned non-chiral compound (1) is not used as the non-chiral compound having the N phase in the above ferroelectric liquid crystal composition, the composition has no N phase and the orientation is inferior.

Comparative Example 2 In place of the liquid crystal composition used in Example 5, the compound of (1) was used as the non-chiral compound having an N phase, and the compound of (8) below was used.
A ferroelectric liquid crystal composition having the composition shown in was prepared.

[0081]

[Table 5]

The phase transition, response time at 25 ° C., rotational viscosity coefficient, spontaneous polarization and tilt angle were measured in the same manner as in Example 3 except that the above composition was used. Got the value. S _C ^* ← → S _A : 58.0 ° C. S _A ← → Iso: 78.2 to 83.5 ° C. τ = 57 μs, η = 236 mPas, Ps = 25.1 nCcm ⁻² , θ = 20.0 °

The above-mentioned ferroelectric liquid crystal composition uses a conventional non-chiral compound having a tricyclic structure having an N phase, but the composition has no N phase and the orientation is inferior. It can be seen that the effect cannot be obtained when used in a small amount like the compound of the present invention.

Comparative Example 3 In place of the liquid crystal composition used in Example 5, the compound of (1) was used as the non-chiral compound having an N phase, and the compound of (3) below was used. A ferroelectric liquid crystal composition having a composition was prepared.

[0085]

[Table 6]

Then, the phase transition, the response time at 25 ° C., the rotational viscosity coefficient, the spontaneous polarization and the tilt angle were measured in the same manner as in Example 3 except that the above composition was used. Got the value. S _C ^* ← → S _A : 58.4 ° C. S _A ← → Iso: 67.0 to 69.5 ° C. τ = 87 μs, η = 277 mPas, Ps = 31.9 nCcm ⁻² , θ = 24.0 °

The above-mentioned ferroelectric liquid crystal composition uses a conventional non-chiral compound having a tricyclic structure having an N phase (an oxyacetic acid ester compound, but a tricyclic compound as in the present invention). There is no N phase and the orientation is inferior. It can be seen that the effect cannot be obtained when used in a small amount like the compound of the present invention.

[0088]

The liquid crystal composition using the specific oxyacetic acid ester compound of the present invention as a liquid crystal material exhibits good orientation and high-speed response when used as a device. In particular, when the oxyacetic acid ester compound of the present invention is used as the non-chiral compound having the N phase having a function of imparting good orientation, N is added to the ferroelectric liquid crystal composition even when used in a small amount. A phase can be provided and good orientation can be provided. Therefore, it is possible to obtain a ferroelectric liquid crystal composition having a relatively simple composition and excellent orientation. Moreover, since the oxyacetic acid ester compound of the present invention has the S _c phase at a high temperature, the operating temperature range of the ferroelectric liquid crystal composition can be expanded. Furthermore, since the effect can be obtained with a small amount of use, the viscosity of the composition does not increase, so that the response speed can be maintained at a high level.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G02F 1/13 500 P 8806-2K

Claims (3)

[Claims] 1. The following general formula (I): [Wherein A ¹ and A ² represent a cyclohexane ring or a benzene ring, and at least one of A ¹ and A ² is a cyclohexane ring, and A ³ , A ⁴ and A ⁵ are a benzene ring, a naphthalene ring,
R ¹ represents a hetero ring or an aliphatic ring, which may be the same or different, R ¹ represents a hydrogen atom, an alkyl group or an alkoxy group, and R ² represents a hydrogen atom, an alkyl group, an alkoxy group, a fluorine atom or chlorine. Represents an atom, a bromine atom or a cyano group, and m and n represent 0 or 1. ] The liquid crystal compound represented by these. 2. The following general formula (I): [Wherein A ¹ and A ² represent a cyclohexane ring or a benzene ring, and at least one of A ¹ and A ² is a cyclohexane ring, and A ³ , A ⁴ and A ⁵ are a benzene ring, a naphthalene ring,
R ¹ represents a hetero ring or an aliphatic ring, which may be the same or different, R ¹ represents a hydrogen atom, an alkyl group or an alkoxy group, and R ² represents a hydrogen atom, an alkyl group, an alkoxy group, a fluorine atom or chlorine. Represents an atom, a bromine atom or a cyano group, and m and n represent 0 or 1. ] A ferroelectric liquid crystal composition comprising a liquid crystal compound and a chiral compound represented by: 3. The liquid crystal composition further comprises a compound represented by the following general formula (II) as a non-chiral compound: embedded image [Wherein B ¹ and B ² represent a benzene ring or a heterocycle, are different from each other, and R ³ and R 2
⁴ represents an alkyl group or an alkoxy group. ] The ferroelectric liquid crystal composition according to claim 2, which contains a liquid crystal compound represented by the following formula.