JPS6118541B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel liquid crystal compound useful as a material for liquid crystal display elements and a liquid crystal composition containing the same. Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, and depending on the driving method, there are TN type (twisted matic type), DS type (dynamic scattering type), and guest/host type. There are various types such as type and DAP type. Liquid crystal compositions with negative dielectric anisotropy are mainly used in DS type compositions, but by adding a liquid crystal material with positive dielectric anisotropy to a liquid crystal material with negative dielectric anisotropy, dielectric It is possible to change the anisotropy to a positive value, which allows it to be used in TN type display elements, which are currently the most widely used. The compound of the present invention is a novel nematic liquid crystal compound having negative dielectric anisotropy that can be used for such purposes. That is, the present invention is based on the general formula (In the above formula, R and R represent an alkyl group or an alkoxy group having 2 to 10 carbon atoms.) The present invention is an enyl ester and a liquid crystal composition containing at least one thereof. The present compound is stable against light, water, heat, air, etc., and also has good compatibility with other liquid crystal compounds, making it very suitable for use as a component of a liquid crystal composition. The compound of the present invention can be produced as follows. First, by reducing 6-substituted-naphthalene-2-carboxylic acid with metallic sodium in isoamyl alcohol, 6-substituted-1,
2,3,4-tetrahydronaphthalene-2-carboxylic acid is produced. Then 6-substitution-1,2,
3,4-tetrahydronaphthalene-2-carboxylic acid is reacted with thionyl chloride to form an acid chloride. When this is reacted with a solution of 4-substituted phenol in pyridine, 6-substituted-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4-substituted phenyl ester is produced. Expressing the above in a formula, Table 1 shows the physical properties of the compound of the present invention obtained as described above.

【table】

[Production of 6-substituted-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-substituted phenyl ester]

Add 10 ml of thionyl chloride to 0.01 mo of 6-substituted-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid, heat it to 60℃ on a hot water bath, and allow the reaction to become completely homogeneous in about 1 hour. . After heating for an additional hour, excess thionyl chloride was distilled off under reduced pressure, and the remaining oil was 6-substituted-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid chloride. Add this to 0.01 ml of p-substituted phenol dissolved in 5 ml of pyridine, stir well and leave overnight. Pour this reaction solution into water and extract the oil with 50 ml of toluene. The toluene layer was washed with 6N hydrochloric acid, then with 2N aqueous sodium hydroxide solution, then washed with water until neutral, and the toluene was distilled off using hydraulic pressure. The remaining oil was recrystallized with ethanol to obtain the target product, 6-substitution. -1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-substituted phenyl ester is obtained. The physical properties of the obtained product are shown in Table 1 above, and the amount of raw materials used, yield, yield, etc. are shown in Table 2.

[Table] Example 2 6-pentyl-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid, 4'-ethoxyphenyl ester (No. 1 in Table 1) 30 parts 6-heptyl- 1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-ethoxyphenyl ester (No. 4 in Table 1) 20 parts 6-pentyloxy-1,2,3,4-tetrahydro Naphthalene-2-carboxylic acid-4'-pentylphenyl ester (No. 10 in Table 1) 10 parts 6-pentyloxy-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4' -Ethoxyphenyl ester (No. 6 in Table 1) 10 parts 6-pentyl-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-pentylphenyl ester (No. 6 in Table 1) No. 2) 30 parts of triethyl-octylammonium bromide
The C-N point of the liquid crystal composition dissolved at 200 ppm is 18
℃, and the N-I point was 55℃. Thickness of this composition
A DS type liquid crystal display element was made by sealing it in a 10 μm vertically aligned cell and the threshold voltage was measured.
The voltage was 7.0V, and the saturation voltage was 22V. Also, 25V at 25℃,
The response rise time when applying a 50Hz rectangular wave is
The time was 350msec, and the fall time was 500msec. Example 3 (Application example 2) 6-pentyl-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-ethoxyphenyl ester (No. 1 in Table 1) 30 parts 6- Pentyloxy-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid-4'-pentylphenyl ester (No. 10 in Table 1) 10 parts 6-pentyloxy-1,2,3, 4-tetrahydronaphthalene-2-carboxylic acid-4'-ethoxyphenyl ester (No. 6 in Table 1) 10 parts 6-pentyl-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid A liquid crystal composition with a composition of 20 parts of 4'-pentyl phenyl ester (No. 2 in Table 1) and 30 parts of trans-4'-propyl (4-cyanophenyl) cyclohexane has positive dielectric anisotropy;
The C-N point was 10°C and the N-I point was 53°C. This composition was deposited with SiOx and rubbed to a thickness of 10 μm.
When a TN-type liquid crystal cell was constructed by encapsulating it in a TN-oriented cell of 2.0 m, and its characteristics were measured, the threshold voltage was 2.2V.
The saturation voltage was 3.2V. Also, 32Hz, 4.5V at 25℃
The response rise time when a voltage of is applied is
The time was 200msec, and the fall time was 300msec.

Claims (1)

[Claims] 1. General formula (In the above formula, R and R' represent an alkyl group or an alkoxy group having 2 to 10 carbon atoms.) enyl ester. 2 General formula (In the above formula, R and R' represent an alkyl group or an alkoxy group having 2 to 10 carbon atoms.) A liquid crystal composition containing at least one enyl ester.