JPS6056932A - Halogenoterphenyls - Google Patents

Abstract

NEW MATERIAL:The halogenoterphenyl compound comprising the 4''-substituted- 4-halogen-p-terphenyl of formula I (R is 1-10C alkyl or alkoxy; X is F or Cl). EXAMPLE:4''-Hexyl-4-fluoro-p-terphenyl. USE:A liquid crystal compound. It has low viscosity, high clear point and broad liquid crystal temperature range. PREPARATION:The compound of formula I is prepared by the chloroanyldehydrogenation reaction of 4-(4-alkyl-1-cyclohexen-1-yl)-4'-halogenobiphenyl of formula II or 4-[4-(4-substituted-phenyl)-cyclohexen-1-yl]halogenobenzene of formula III.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to halogenoterphenyls and compositions thereof, and more specifically to a novel liquid crystal material having positive dielectric anisotropy and a liquid crystal composition containing the same.

Liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, and can be classified into TN type (twisted nematic type), D8 type (dynamic scattering type), guest type, and D8 type (dynamic scattering type) depending on the display format.
There are various types such as host type and DAP type, and the properties of liquid crystal materials suitable for each type of use are different. It is common for all liquid crystal materials to be stable against moisture, air, heat, light, etc., and materials that exhibit a liquid crystal phase over as wide a temperature range as possible, centered around room temperature, are desired. . At present, there is no single compound substance that satisfies these conditions, and liquid crystal compositions obtained by mixing several types of liquid crystal compounds and non-liquid crystal compounds are used. In particular, recently there has been a demand for liquid crystal display elements that operate in a wide temperature range from low to high temperatures. In order to satisfy such requirements, lowering the viscosity is an effective means. However, in general, those with a high clearing point tend to have a high viscosity, and those with a low viscosity, such as alkylphenyl Schiff tetrahexane derivatives, tend to have a low clearing point.

An object of the present invention is to provide a novel liquid crystal compound that has a high clearing point and a wide liquid crystal temperature range despite its low viscosity, and a liquid crystal composition containing the same.

That is, the present invention provides a 4'-substituted compound represented by the general formula % (1) (in the above formula, 几 represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms, and X represents r or C4). -4-halogeno-P-terphenylnyolhalokenoterphenyls and liquid crystal compositions containing them.

For 4"-hexyl-4-fluoro-p-terphenyl, which is an example of the compound of formula (1) of the present invention, 20 tl
Although the viscosity is as low as AOCP, the liquid crystal temperature range of 7 is wide from about 80C to 210C and has a high clearing point, making it a liquid crystal composition used for liquid crystal display cells that operate in a wide temperature range from low to high temperatures. It is a very useful compound as a constituent component. In addition, although the dielectric anisotropy Δε is about 2, the threshold voltage and saturation voltage of the liquid crystal composition to which the compound of the present invention is added do not increase much compared to those of the composition to which no compound is added. It's about the same.

Furthermore, it is stable against light, heat, air, moisture, etc., and has a wide range of applications.

Next, the method for producing the compound of the present invention will be described.
4-( obtained according to the method described in Publication No. 40429
4-alkyl-1-cyclohexen-1-yl) -4
'-halogenobiphenyl (compound GD) or JP-A-57
-4 obtained according to the method described in Publication No. 167934
-(4-(4-substituted phenyl)cyclohexen-1-yl)halogenobenzene (compound GID) is subjected to a chloranyl dehydrogenation reaction to obtain the desired 4''-substituted-4-halogeno-p
- Terphenyl can be produced.

The above is expressed as a chemical formula as follows.

I) (In the above formula, R,

Example 14 Preparation of 4”-hexyl-4-fluoro-P-terphenyl 4-(4-(4-hexylphenyl)cyclohexene-
1-yl]fluorobenzene (compound (g)) 5y was dissolved in 200 ml of xylene, and then chloroanil 8.2
g was added thereto and the mixture was refluxed for 20 hours.

The reaction product was then extracted with 200% of t/l/ene, washed successively with a small amount of 6-N hydrochloric acid and 2-N thorium hydroxide, and further washed with water until the washings became neutral. The solvent was then distilled off under reduced pressure, and the residue was recrystallized from toluene to obtain the desired crystals of 4'-hexyl-4-fluoro-p--terphenyl. The crystalline smectic point of this product was approximately 80C1, and the smectic clearing point was 216C. Yield is 1.5
g (yield 30%).

According to Example 1, 4-(4-(4-hexylphenyl)
cyclohexen-1-yl]4-instead of fluoroben
Using (4-1f-substituted phenyl)cyclohexen-1-yl]halogenobenzene or 4-(,4-alkyl-1-cyclohexen-1-yl)-4'-halogenobiphenyl, 4''-substituted-4-halogen /-p-terphenyl can be produced.

Application example 1 The nematic clearing point of a liquid crystal composition having the following composition is 52C1
The dielectric anisotropy value Δε is +105. When this liquid crystal composition was sealed in a TN cell (twisted nematic cell) having a cell thickness of 10 μm and having opposing transparent electrodes, the operating threshold voltage was 1.53V and the saturation voltage was 2.12V. The viscosity was 230p at 20C.

The nematic clearing point of a liquid crystal composition obtained by adding 5 parts by weight of 4"-hexyl-4-fluoro-P-terphenyl, which is one of the compounds of the present invention, to 95 parts by weight of the above liquid crystal composition was 5.
The dielectric anisotropy value Δε decreased to +10.1. This is T with the same cell thickness of 10 μm as described above
The operating threshold voltage of the N cell inserted is 1.53V,
The saturation voltage was 2.14V. Also, the viscosity at 20C is 2
It was 4Cp.

that's all

Claims (2)

[Claims] (1) 4″-substituted-4-halogeno-p- represented by the general formula (in the above formula, R represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms, and X represents ■ or Ct) Halogenoterphenyls by terphenyls. (2) 4'-substituted-4-halogeno-P- represented by the general formula (in the above formula, 几 represents an argyl group or an alkoxy group having 1 to 10 carbon atoms, and X represents F minus Ct) A liquid crystal composition comprising a terphenylnylorhalokenoterphenyls.