JPS60224666A - Ether derivative of 3-fluoro-4-cyanophenol - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R<1> is 1-10C alkyl; R<2> is group of formula II, formula III, formula IV, etc.). EXAMPLE:Trans-4-hexylcyclohexylmethyl-3-fluoro-4-cyanophenyl ether. USE:A liquid crystal composition. It is a monotropic liquid crystal having positive dielectric anisotropy, and exhibiting a liquid crystal phase when cooled from isotropic liquid. It has broad liquid crystal temperature range, high clear point and excellent stability. PREPARATION:The compound of formula I can be prepared by reacting the halide of formula R<1>-R<2>-CH2Y (Y is halogen such as Cl and Br) with the phenol derivative of formula V in a solvent such as ethyl alcohol, 2-methoxyethanol, etc. in the presence of an alkali such as NaOH, at a temperature between the room temperature and the refluxing point of the reaction mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel organic compound, and more particularly to a novel compound that can be used as a component added to a liquid crystal material having positive dielectric constant anisotropy.

As is well known, liquid crystal compounds are used in various display devices by utilizing the anisotropy of dielectric constant and anisotropy of refractive index in the liquid crystal phase.

It can be used for liquid crystal display elements that apply the electro-optic effect of these Display Company liquid crystals, and display elements that use nematic liquid crystal that applies the thermo-optic effect of liquid crystals and has a twisted arrangement of liquid crystal molecules, as well as other suitable devices. It is also used in liquid crystal display devices that apply the guest-host effect using liquid crystal compounds containing dye substances and liquid crystal mixtures.

Each component of these liquid crystal materials alone has its own characteristics, namely:
There is no one that can withstand practical use in terms of liquid crystal temperature range, operating voltage, response performance, etc., and in practice, a product that can withstand some use is obtained by mixing several types of liquid crystal compounds or non-liquid crystal compounds.

OBJECTIVE OF THE INVENTION #'i It is to provide a compound useful as a component of a stable liquid crystal composition with excellent practical performance.

The present invention is based on the general formula (wherein R1 represents an alkyl group having 1 to 10 carbon atoms,
, R"d-0-, -Q-, -00-.

A liquid crystal composition comprising an ether derivative of 8-fluoro-4-cyanophenol represented by ( ) (n, -GO- and () (representing a group selected from Y) and the compound. It is.

Among the compounds provided by the present invention, for example, the compound in which R2 is 0 has a strong positive dielectric constant anisotropy (Δε≠17), and is a monotropic liquid crystal in which a liquid crystal phase appears upon cooling from an isotropic liquid. It is. Also, R2 is K)(), -40-o-
Compounds with the structure also have strong positive dielectric anisotropy,
It is a novel liquid crystal compound that has a wide liquid crystal temperature range and has a high clearing point and excellent stability.

The compound according to the present invention cannot be used alone for ordinary display elements. However, it has excellent compatibility with other P-type or N-type liquid crystals, such as Schiff base type, azoxy type, benzoic acid phenyl ester type, cyclohexane carboxylic acid phenyl ester type, cyclohexane carboxylic acid cyclohexyl ester type, biphenyl type, phenyl type. Cyclohexane type, phenylmetadioxane type.

The dynamic voltage of a liquid crystal composition obtained by mixing one type of liquid crystal system such as phenylpyrimidine type or several types of liquid crystal systems can be lowered.

Next, an example of a method for producing the compound of the present invention will be shown using a reaction formula.

aOH R1-r('-CHtY +HO<nCN(1) ■ r゛(1) (In the formula, R1 and R1 are the same as above. Also, Y#'iC
1, represents a halogen atom of Br. ) That is, the above halide 1) and the phenol derivative (1) are reacted in a suitable organic solvent such as ethyl alcohol or 2-methoxyethanol in the presence of an alkali such as sodium hydroxide. The reaction can be carried out at normal pressure and at a temperature ranging from room temperature to the reflux temperature of the reaction mixture. The target compound of formula (1) can be isolated by subjecting the system containing the reaction product to a series of purification treatments such as solvent extraction, water washing, drying, and recrystallization. Further, the halide used in the present invention can be synthesized according to the method described in JP-A-54-157541.

The uses and properties of the compounds of the present invention will be explained in detail by way of examples and application examples.

Example 1 Trans-4-hexylcyclohexylmethy-8-7
Production of kyF rho-4-cyanophenyl ether ((I)
Compounds in which R1 is C5H1s and R'' is K) 8-Fluoro-4-cyanophenol 2.0f (14,
6 mmol) was dissolved in 10 cc of 2-methoxyethanol, 8 oc of 4N sodium hydroxide aqueous solution was added thereto, and the mixture was heated to reflux. ，
6 mmol) was added. After this, the reaction mixture was heated and reacted for 4 hours. After the reaction was completed, the reaction mixture was allowed to cool to room temperature, and 100 ccK of water was added to the reaction product. The separated oil was dissolved in toluene 20
Extracted with cc. After washing the toluene extract with a 10% sodium hydroxide solution and then with water, the anhydrous sulfur was dried using sodium, and the toluene was distilled off. 1 of the remaining oil
Recrystallize from 0 cc of ethyl alcohol to obtain target product 2.
．． I got 81.

This substance is a nematic liquid crystal substance, and its melting point (CI Bunkansho = threat point) is 55.6°C, nematic - transparent A (N-1 point).
The temperature reached 15.3°C'''c.

Experiments li2-11 The physical properties of compounds with other structures manufactured by a method similar to Example 1 are listed in Table 1 together with the results of Example 1. In the table, the crystal phase is abbreviated as C, the nematic phase as N, and the transparent phase as I. The numbers between the dots below the abbreviations indicating each phase indicate the transition point, and those with - indicate no phase. ()
indicates monochrome pink.

Table 1 Application Example 1 The temperature range of nematic liquid crystal is -5 to 52 degrees.
It is C. This liquid crystal composition (A) is
The operating threshold voltage of the N cell sealed is 1.54V,
The saturation voltage ti was 2.18Vf. Also, the viscosity is 28 cp at 20°C and the dielectric anisotropy is one of the properties of trans-4-hexylcyclohexylmethyl-3- shown in Example 1.
Fluoro Celsius is sealed in the TN cell described above, and the operating threshold voltage is 1.88V and the saturation voltage is 1.80V.
It decreased to V. The viscosity at 20°C is 81. Ocp, the dielectric anisotropy was 12.4.

Application Example 2 90 parts by weight of the same liquid crystal composition (A) as in Application Example 1 contained trans-4-( shown in Example 8, which is one of the compounds of the present invention).
The nematic liquid crystal temperature range of the liquid crystal composition to which 10 m [fi part t'' of trans-4-propylcyclohexyl)cyclohexylmethyl-8-fluoro-4-cyanophenyl ether was added was -7 to 69.2°C. As mentioned above, although it was sealed in a TN cell with a cell thickness of 10 μm, the operating voltage was 1.85 V, the saturation voltage was 1.82 V, the viscosity was 84 cp at 20°C, and the dielectric anisotropy was 12.
It was 8.

From this, it was found that the use of the compound of the present invention has the effect of widening the liquid crystal temperature range of the obtained liquid crystal composition and lowering the driving voltage without increasing the viscosity.

that's all

Claims (2)

[Claims] (1) General formula (wherein R1 represents an alkyl group having 1 to 10 carbon atoms,
m2u-0-, -Q-, -0-0-1X)(n, -Q(
Ether derivatives of 3-fluoro-4-cyanophenol represented by >- and () (indicating a group selected from needles). (2) General formula (wherein 81 represents an alkyl group having 1 to 10 carbon atoms,
8-fluoro-4-cyano represented by ()+ -G-, -40-0-. A liquid crystal composition containing an ether derivative of phenol.