JPS61134364A - 6-substituted naphthalene-2-carboxylic acid 3-halogeno-4-cyanophenyl ester - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is 1-10C alkyl, alkoxy; X is halogen). EXAMPLE:3-Fluoro-4-cyanophenyl 6-pentylnaphthalene-2-carboxylate. USE:A constituent of liquid crystal compositions: it has large dielectric and optical anisotropy and shows good compatibility with other constituents in combination. PREPARATION:The reaction of naphthalenecarboxylic acid chloride of formula II with 3-halogeno-4-cyanophenol of formula III is carried out in the presence of pyridine to give the compound of formula I. The use of a composition containing the same gives a liquid crystal display elements of low drive voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel liquid crystal compound and a liquid crystal composition containing the compound.

[Prior Art] □ Display elements using liquid crystals are widely used in watches, calculators, etc. These liquid crystal display elements utilize optical anisotropy and dielectric anisotropy of liquid crystal materials. Liquid crystal phases include a nematic liquid crystal phase, a smectic liquid crystal phase, and a cholesteric liquid crystal phase, among which those using nematic liquid crystal are most widely put into practical use. These K correspond to the electro-optic effect applied to liquid crystal displays, and there are display elements such as TN (twisted nematic) type, DS (dynamic scattering) type, guest-host type, and DAP type, and each type is used. It is desirable that the liquid crystal material used exhibits a liquid crystal phase over as wide a natural temperature range as possible. At present, there is no single liquid crystal substance that satisfies these conditions, and several types of liquid crystal substances or even non-liquid crystal substances are mixed and put into practical use. These substances are required to be stable against moisture, light, heat, air, and the like.

Recently, there has been an increasing demand for liquid crystal display elements that can be driven at particularly low voltages, and in order to meet such demands, a liquid crystal composition with a large dielectric constant anisotropy value (hereinafter abbreviated as lε) has become necessary. ing.

In general, for K to obtain a liquid crystal composition with a large Δε value, it is sufficient to use a component with a Δe value as large as possible. It is necessary to widen it or at least not squeeze it. In addition, a liquid crystal composition with large optical anisotropy (hereinafter abbreviated as "nor") can suppress the occurrence of color unevenness due to local unevenness in the distance between the substrates of a liquid crystal display element, and can reduce the distance between the substrates. It has the advantage of being able to increase the electric field strength even with applied voltage. Therefore, there is a demand for the emergence of liquid crystalline compounds with a large Δ path.

[Problem that the invention seeks to solve]

The purpose of the present invention is to solve the above-mentioned problems, and the first purpose is to provide a novel compound that can be used as a component of a liquid crystal composition. Good compatibility when used with other ingredients,
It is an object of the present invention to provide a liquid crystal compound that does not at least reduce the liquid crystal temperature range.

The second object is to provide a liquid crystal composition containing a novel liquid crystal compound and having large values of ε and Δ.

[Structure of the invention].

The first invention of the present invention, 6-substituted naphthalene-2-carboxylic acid-3-halogeno-4-cyanophenyl ester (hereinafter referred to as the compound of the present invention), has the general formula (wherein R is the number of carbon atoms It is characterized by being represented by 1 to 10 alkyl groups or alkoxy groups (X represents a halogen group).

The liquid crystal composition of the second aspect of the present invention has the general formula (wherein R
is an alkyl group or alkoxy group having 1 to 10 carbon atoms;
-substituted naphthalene-2-carboxylic acid-3-halogeno-4
- Contains cyanophenyl ester.

The compound of the present invention is a 6-substituted naphthalene-2-carboxylic acid-3-halogeno-4-cyanophenyl ester represented by the formula (1)K. Specifically, 6-alkylnaphthalene-2-carboxylic acid-3-halogeno-4-cyanophenyl ester or 6-alkoxynaphthalene-2-carboxylic acid-3-halogeno-4-cyanophenyl ester.

To explain the compound of the present invention in more detail, R of formula (1)
is an alkyl group or an alkoxy group, and specific alkyl groups include methyl, ethyl, and straight chain alkyl groups.
Loop tetrabiru, looptyl, leupentyl, 3-hemoyl, octyl, octyl, lunonyl, and decyl, and branched alkyl groups include b-propyl, 1-methylpropyl, 2-methylglobil, 1-methylbutyl. , 2-methylbutyl, 3-methylbutyl, 1-
Methylpentyl, 1-ethylpentyl, 2-methylpentyl, 1-methylhexyl, 2-ethylhexyl, 1-
Examples include methylheptyl. Examples of the alkoxy group include alkoxy groups corresponding to the aforementioned straight-chain or branched alkyl groups. Furthermore, examples of X in the norogen group include F, C1, and Br.

The method for producing the compound of the present invention can be shown by the following reaction formula.

(1) (III) (R and X in the formula are the same as above), that is,
The corresponding 7-talenecarboxylic acid chloride [formula (■)] and 3-nologno-4-cyanphenol [formula @)] were reacted in the presence of pyridine to form a 6-substituted tytalene-2-carboxylic acid-3-710geno. 4-cyano 7-ester [formula (I)] can be obtained.

The liquid crystal composition of the present invention is characterized in that it contains the compound of the present invention represented by the general formula (I). Other components other than the compound of the present invention include, for example, ester-based, thick base-based,
Examples include liquid crystal compounds of biphenyl type, phenylcyclohexane type, and heterocyclic type. For example, examples of ester liquid crystal compounds include trans-4-furkylcyclohexanecarboxylic acid-4-alkylphenyl ester, trans-4-alkylcyclohexanecarboxylic acid-4-
Alkoxyphenyl ester, 4-alkoxybenzoic acid-4-alkylphenyl ester, 4-alkyl ben, fragrance! -4-cyanophenyl ester, 4-(trans-4-alkylfuclohexyl)benzoic acid-4-cyanophenyl ester, etc. Schick salt a-based liquid crystal compounds include 4-alkoxybenzylidene-4-al, canoyloxyanili/ , 4-alkoxybenzylidene-4-alkylaniline, 4-alkoxybenzylidene-4-cyanoaniline, etc., as biphenyl-based liquid crystal compounds,
4'-Alkyl-4-cyanobi-1enyl 4/ ++
Examples of phenylcyclohexane-based liquid crystal compounds include trans-4-furkyl-(4
Examples of heterocyclic liquid crystal compounds include 5-alkyl-2-(
4-cyanophenyl)-1,3-dioxane, 5-alkyl-2-(4-cyanophenyl)hyrimidine, 5-
Examples include cyano-2-(4-alkylphenyl)virimi and gin.

The content of the compound of the present invention in the composition of the present invention varies depending on the types of other components to be mixed, and is usually 1 to 30% by weight, preferably 5 to 15% by weight, based on the other components. A specific example is a composition containing 85 to 95% by weight of a mixture of one to several types of trans-4-alkyl-(4-cyanophenyl)cyclohexane and 5 to 15% by weight of the compound of the present invention.

Furthermore, specific examples of the mixture of one to several types of trans-4-alkyl-(4-cyanophenyl)cyclohexane in the above composition include ``20 to 35% by weight of trans-4-propyl-(4-cyano7yl)cyclohexane; 30-45% by weight of trans-4-benzene(4-cyanophenyl)cyclohexane, trans-4-heptyl-(4
-cyanophenyl)cyclohexane 20 to 35% by weight.

〔Effect of the invention〕

The effects of the invention of the compound of the present invention are as follows: 6-alkylnaphthalene-2-carboxylic acid-3 is a novel compound that has good compatibility as a constituent component of a liquid crystal composition and has not previously existed.
-Halogeno-4-cyanophenyl ester or 6-alkoxynaphthalene-h2-carvone@-3-halogeno-4-cyanophenyl ester could be provided. Second, the Δε of the compound of the present invention is about +30, so by adding a small amount to other components, it is possible to increase lε of the liquid crystal composition obtained, and the liquid crystal composition can be used. This is useful as a component that can lower the driving voltage of liquid crystal display elements.

Thirdly, the isotropic liquid phase transition point (hereinafter N-I
(abbreviated as point) are all around 100° C., so by adding a small amount as a component of the liquid crystal composition, the NI point of the liquid crystal composition can be raised.

Fourthly, since the fullness of the compound of the present invention is about 0.21, the Δ path of the liquid crystal composition can be increased by adding a small amount.

The first advantage of the composition of the present invention is that it provides a liquid crystal composition containing a novel compound that has not been seen heretofore. Second, Δ6. ΔL is large. Thirdly, N-I is high. Fourthly, by using the composition of the present invention, a liquid crystal display element with low driving voltage can be obtained.

〔Example〕

The present invention will be explained in further detail by the following examples.

Example 1 6-venturna 7talene-2-carboxylic acid-3-fluoro-4-cyanphenyl ester 1.21 (o, oos 7 moz) of 3-fluoro-4-cyanphenol was dissolved in 5Alil of pyridine and while stirring, 6- Pentylnaphthalene-2-carboxylic acid chloride 2.2.9 (0,
0083ya6j) was added.

Thereafter, the mixture was left in the apparatus overnight, and toluene 501117 was added thereto, and the mixture was poured into water. The toluene layer separated into layers was treated with 6N-hydrochloric acid and 2N-hydrochloric acid.
After washing with an aqueous solution of IJ cum (hydroxide), it was dried using anhydrous sodium sulfate. The white solid obtained by distilling toluene off under reduced pressure was recrystallized using ethanol to obtain the target product 6-benturna7talene-2-carboxylic acid-3-fluoreI-4-cyanophenyl ester 2.
, o y (0,0055 m6j) was obtained (yield: 63 h).

The crystal-nematic phase transition point (hereinafter abbreviated as C-N point) of this product was 64.4°C, and the N-I point was 104.4°C. In addition, the single element analysis value is C near 6, s 5
%, H: 5.70%, calculation/value C near 6.44ch,
H: 5.58%). In addition, this material was mixed with a trans-4-furkyl-(4-cyanophenyl)cyclohexene liquid crystal composition and calculated by extrapolation.
The values of and were +35.2.0.212, respectively.

Examples 2 to 4 The same procedure as Example IK was carried out except that the corresponding acid chloride was used in place of 6-venturna7talene-2-carboxylic acid chloride in Example 1, and 6-hegtylnaphthalene-2-carboxylic acid chloride was used. Acid-3-fluoro-4-cyanophenyl ester, 6-pentyloxynaphthalene-2
-Carboxylic acid-3-fluoro-4-cyanophenyl ester and 6-octyloxynaphthalene-2-carboxylic acid-3-fluoro-4-cyanophenyl ester were produced. The phase transition points and elemental analysis results of these compounds are shown in Table 1 together with the results of Example 1.

Example 5 (Application example) The N-I point of the liquid crystal mixture (4) having the following composition is 52.1°C,
The value of Δε is +11.2, and the value of Δpath is 0.119.

As a liquid crystal cell, substrates coated with silicon oxide and having transparent electrodes of rubbed tin oxide were placed facing each other (assembled, the distance between the electrodes was 10 μm), and the above liquid crystal mixture (4) was sealed, and 20 When its characteristics were measured at ℃, the threshold voltage (hereinafter abbreviated as vth) was 1.
54 V% saturation voltage (hereinafter abbreviated as Vs) is 2.13
It was V.

This liquid crystal mixture (A) 85 weight SK 6-pentylnaphthalene-2-carboxylic acid-3 prepared in Example 1 of the present invention
- The N-1 point of the composition in which 15% by weight of fluoro-4-cyanophenyl ester was dissolved increased to 57.7°C, and Δ6
The value of was +14.8, and the value of ΔL was 0.133, both of which increased significantly.

Regarding the characteristics of the composition sealed in the same liquid crystal cell as described above, vth is 1.38V, Vsat
significantly decreased to 1.87 V.

that's all

Claims (1)

[Claims] 1) Represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms, and X represents a halogen group) 6-substituted naphthalene-2-carboxylic acid-3-halogeno-4-cyanophenyl ester. (2) 6-substituted naphthalene represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. A liquid crystal composition comprising -2-carboxylic acid-3-halogeno-4-cyanophenyl ester.