JPS5995242A - Ester derivative containing trifluoromethyl group - Google Patents

Abstract

NEW MATERIAL:A trans-4-alkyl-trans-4''-( 3-trifluoromethylbenzoyloxy )-octadecahydro-trans-p-terphenyl of formula I (R is H or 1-10C alkyl). EXAMPLE:trans-4- Propyl-trans-4'' -( 3-trifluoromethylbenzoyloxy )-octadecahydro- trans-p-terphenyl. USE:A liquid crystal substance exhibiting the liquid crystal phase within a wide temperature range, having a low viscosity and about +0.5 dielectric anisotropy though a high clear point while changing the threshold voltage and saturation voltage of a composition not so much, and stable to moisture, heat, light, etc. PROCESS:A trans-4-alkyl-trans-4''-hydroxy-trans-octadecahydro-p-terphenyl of formula II is reacted with a compound of formula III in the presence of pyridine to give the aimed compound of formula I .

Description

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

Display elements using liquid crystals have become widely used in watches, calculators, etc. This liquid crystal display element utilizes the properties of optical anisotropy and = The one used is the one most widely put into practical use. That is, there are TN (twisted nematic type) type, DS (dynamic scattering type) type, guest-host type, DAP type, etc., and the properties required of the liquid crystal materials used for each type are different.

However, in any case, it is desirable that the liquid crystal materials used in these display devices exhibit a liquid crystal phase over as wide a range as possible in nature, but at present there is no single material that satisfies such conditions. Instead, the current situation is to mix several types of liquid crystal substances or non-liquid crystal substances to obtain something that can be put to practical use. In addition, these substances must of course be stable against moisture, light, heat, air, etc. Furthermore, the threshold voltage and saturation voltage necessary to drive the display system must be as low as possible, and In order to increase the response speed, it is desirable that the viscosity be as low as possible. By the way, in order to widen the liquid crystal temperature range toward high temperatures, it is necessary to use a liquid crystal substance with a high melting point as a component, but liquid crystal substances with a high melting point generally have a high viscosity, so the liquid crystal composition containing it also has a high viscosity. As a result, the response speed of liquid crystal display confectionery that can be used at high temperatures, for example, up to about 80° C., particularly at low temperatures, tends to be significantly slow. However, the present inventors have discovered a liquid crystal material that exhibits a liquid crystal phase over a wide temperature range, has a cylindrical clearing point, and has a low viscosity, and has thus arrived at the present invention.

That is, the present invention provides a trans-4-alkyl-tran represented by the general formula (in the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms): y, -
4″-(3-) 1) Fluoromethylbenzoyluoquine)-octadecahydro-trans-p-terphenyl and a liquid crystal composition containing the same.

The compounds of the invention have high clearing points, for example trans-4-propyl-trans-
4"-(3-)!J fluoromethylbenzoyloxy)
-C of octadecahydro-trans-p-terphenyl
-8 point u112℃, S-N point 225℃, N-I point 2
It exhibits a liquid crystal phase in a wide temperature range of 30° C., and by adding it as a component to a composition, the clearing point can be raised without increasing the viscosity of the liquid crystal composition.

Further, although the dielectric anisotropy value of the compound of the present invention is about +0.5, it does not change the threshold voltage and saturation voltage of the composition so much. It also has good stability against moisture, heat, light, etc.

Next, the method for producing the compound of the present invention will be described.
-Alkyl-trans-4″-hydroxy-trans-
Octadecahydro-p-terphenyl is reacted with 3-trifluoromethylbenzoic acid chloride in the presence of pyridine to obtain the desired trans-4-alkyl-trans-4''-(3
-)rifluorometherbenzoyluoquine)-octadecahydro-trans-p-terphenyl was prepared. The above is represented by a chemical formula: (R is the same as above) Hereinafter, the manufacturing method and usage examples of the compound of the present invention will be explained in more detail with reference to Examples.

Example 1 [Production of trans-4-propyl-trans-4"-(3-trifluoroσmetherbenzoyluoquine)-octadecahydro-trans-p-terphenyl] trans-4-propyl-trans-4"- Hydroquine-octadecahydro-trans-p-terphenyl 1
, 5t2 3-Trifluoromethylbenzoic acid chloride 12 is added to the solution dissolved in pyridine 50- and allowed to stand overnight. Add 200ml of toluene, and remove the toluene layer in a separatory funnel, first with 6N hydrochloric acid, then with 2N caustic soda solution.
Finally, wash with water until neutral. After drying it over anhydrous sodium sulfate, the toluene layer was distilled off under reduced pressure. When the precipitated crystals are recrystallized with acetone, the desired trans-4 is obtained.
-Propyl-trans-4"-(3-todifluoromethylpenzoyloxy)-octadecahydro-trans-
p-terphenyl was obtained. Yield: 0.7F, yield: 29.

The C-S point of this product is 112℃, the S-N point is 225℃,
The N-I point was 230°C.

Example 2.3 Trans-4-propyl-trans- in Example 1
4″-Hydroquine-octadecahydro-trans-p-
Table 1 is carried out exactly as in Example 1 using trans-4-alkyl-trans-4"-hydroxy-octadecahydro-trans-p-terphenyl with another argyl group instead of terphenyl. The compounds shown in Example 2.3 were prepared. Their physical properties are shown in Table 1 together with the results of Example 1.

Table 1 Example 4 (Usage example) trans-4-propyl-(4'-anophenyl)-chlorohexane 28% trans-4-pentyl-(4'-anophenyl)
The N-I point of a liquid crystal composition having a composition of 42-thitrans-4-heptyl-(4'-anophenyl)-enclohexane 30 units is 52°C. When this liquid crystal composition was sealed in a TN cell (twisted nematic cell) K with a cell thickness of 10 μm, the operating threshold voltage was 1.53
V, the sum voltage was 2.12 V. Further, the viscosity was 23 Cp at 20°C.

To 97 parts of this liquid crystal composition was added the trans-transformer produced in Example 1.
The N-I point of the liquid crystal composition to which 3 parts of 4-propyl-trans-4''-(3-trifluoromethylbenzoyluoquine)-octadecahydro-trans-p-terphenyl was added rose to 56°C; When used as a TN cell similar to the above, the threshold voltage is 1.60 V and the saturation voltage is 2.30 V.
■It was. Further, the viscosity was 28 Cp at 20°C.

253

Claims (1)

[Scope of Claims] (Trans-4-alkyl-trans-4" represented by the general formula 11 (in the above formula, 11 represents hydrogen or an alkyl group having 1 to 10 carbon atoms)
-(3-)Lifluoromethylbenzoyloxy)-octadecahydro-trans-p-terphenyl. (2) trans-4-alkyl-trans-4'' represented by the general formula [in the above formula, R represents hydrogen or an argyl group having 1 to 10 carbon atoms]
A liquid crystal composition containing at least one type of -(3-trifluoromethylbenzoyluoquine)-octadecahydro-trans-p-terphenyl.