JPS5995256A - Ester derivative of 4-hydroxy-3-methoxybenzonitrile - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R is H, 1-15C alkyl or alkoxyl; rings A and B are groups of formulas I and II). EXAMPLE:2-Methoxy-4-cyanophenyl 4-pentylbiphenylyl-4'-carboxylate. USE:A liquid crystal display element substance, exhibiting positive dielectric anisotropy, stable to moisture, heat, air and light, etc., and having a wide liquid crsytal temperature range. PROCESS:Carboxylic acid chlorides corresponding to the respective aimed ester derivatives are reacted with 4-hydroxy-3-methoxybenzonitrile in the presence of pyridine to give the respective corresponding aimed ester derivatives.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel liquid crystal material exhibiting 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 their display methods include TN type, DS type, guest-host type, dual frequency method type, DAP type,
There are various methods such as White Tiller type, and each method requires different properties of the liquid crystal material used. For example, depending on the type of display element, a liquid crystal material with a positive dielectric anisotropy Δε may be required, a material with a negative dielectric anisotropy may be required, or a material with an intermediate value may be suitable. However, in any case, the liquid crystal material used must exhibit a liquid crystal phase over as wide a temperature range as possible and be stable against moisture, heat, air, light, etc. At present, there is no single compound that satisfies all of these conditions, and the current state of affairs is to mix several types of liquid crystal compounds and non-liquid crystal compounds to obtain compounds that can withstand practical use.

Recently, there has been an increasing demand for liquid crystal display elements that operate over a wide temperature range, that is, from low to high temperatures. In order to meet these demands, compounds that exhibit a liquid crystal phase over a wider temperature range are desired.

The present invention satisfies these demands.

That is, the present invention provides 4-hydroxy-3-methquine benzonitrile represented by the general formula (in the above formula, R is a hydrogen atom or a carbon number of 1 to 15 carbon atoms (C and each represents -(δ← or 0)). and a liquid crystal composition containing at least one thereof.

The compound of the present invention has a wide liquid crystal temperature range, has a large optical anisotropy value, has a dielectric anisotropy of about +8, is stable against moisture, heat, air, elements, etc., and has a wide temperature range. This compound is suitable for obtaining a liquid crystal composition exhibiting a nematic liquid crystal phase.

First, a method for producing the compound of the present invention will be described. The ester derivatives are reacted with 4-hydroxy-3-methoxybenzonitrile in the presence of pyridine and carbonyl chloride corresponding to 6, respectively, to give the corresponding ester derivatives. In terms of a chemical formula, (in the above formula, R1 and R1 are the same as above) The compounds of the present invention will be explained in more detail with reference to Examples below.

Example 1 (Production of 4-pentylbipheny'J-4'-carboxylic acid-2-methoxy-4-cyanophenyl ester) 4-hydroxy-3-methquine benzonitrile 1.51
Dissolve 2.9 of 4-pentylbiphenyl-4'-carboxylic acid chloride in 10-pyridine and mix well.
? Add. This reaction solution was allowed to stand overnight, then poured into 100 m of water, and the oil was extracted with 100 m of toluene. Tor 1-
The 7th layer was washed with 6N-HO2 and then with 2N-NaOH, then filtered while washing with water until neutral, and toluene was distilled off under reduced pressure. When the remaining crystals are recrystallized with ethanol, the target product 4-penalbiphenylyl-4 is obtained.
/-carboxylic acid-2-methoxy-4-cyanonenyl ester was obtained. Acquisition fix 2.1? , yield 53 cm.

0-N point 141.0~142°4℃, N-1 point 156.
4℃.

Examples 2 to 7 Same as Example 1 except that 1 mol of the corresponding carboxylic acid chloride was used in place of 4-pentylbiphenyl-4'-carboxylic acid chloride in Example 1. A compound of formula (1) was obtained.The results are shown in Table 1.

Table 1 Example 8 (Usage example) Trans-4-propyl-(4'-cyanophenyl)cyclohexane 24% trans-4-pentyl-(4'-cyanophenyl)cyclohexane +j 7
36% trans-4-hebutyl-(4'-cyanophenyl)cyclohexane 25% trans-
The N-x point of liquid crystal composition A having a composition of 15% of 4-pentyl-(4″-noanobiphenyl)cyclohexane is 72°C, and the hexaelectron anisotropy value is +11., tI! at 20°C. The i degree was 29 cp.

In liquid crystal composition A, trans-4-benzene (4"
Nematic temperature range of a liquid crystal composition in which the same amount of trans-4=(trans-4-furobylcyclohexyl)cyclohexanecarboxylic acid-2-methoxy-4-cyanophenyl ester of the present invention is added in place of -cyanobiphenyl)cyclohexane. is 89℃, and the visiting anisotropy value is +1
The viscosity at 0.200 was 31 cp. The compounds of the present invention are thus ideal for widening the nematic temperature range without significantly increasing the viscosity.

that's all

Claims (1)

[Claims] (1) An ester derivative of 4-hydroxy-3-methoxybenzonitrile represented by the general formula (in the above formula, R is a hydrogen atom or has 1 to 15 carbon atoms). (In the above formula, R is a hydrogen atom or a carbon number of 1 to 15 -()
A liquid crystal composition containing at least one ester derivative of 4-hydroxy-3-methoxybenzonitrile represented by - or +.