JPH06172266A - Benzene derivative and liquid crytal composition - Google Patents

Abstract

PURPOSE:To provide a new compound useful as a low-cost liquid crystal display element having excellent response. CONSTITUTION:The compound of formula I (R<1> and R<2> are H, alkyl, alkoxy, halogen, trifluoromethyl, cyano, nitro, etc.; (m) is 1 or 2; Rf is CnF2n+1 or CnF2nH; (n) is 1-18), e.g. 3-bromo-4-hexyloxybenzoic acid 2'-heptadecylfluorooctylethyl ester. The compound of formula I can be produced by reacting a benzoic acid derivative of formula II with an alcohol derivative of the formula HO-(CH2)m.Rf. A liquid crystal composition can be produced by mixing the compound with various liquid crystal substances such as biphenyl-type, phenylcyclohexane-type, phenyl cyclohexylcarboxylate-type and phenylpyrimidine-type liquid crystals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal substance and a liquid crystal composition used for display devices and the like.

[0002]

2. Description of the Related Art Conventionally, as liquid crystal substances used for liquid crystal displays and the like,
As seen in "Liquid Crystal Device Handbook", P107-192 (Nikkan Kogyo Shimbun) edited by Japan Society for the Promotion of Science, 142nd Committee, biphenyl, phenylcyclohexane,
In addition to the so-called bicyclic liquid crystal substance having a skeleton of cyclohexylcarboxylic acid phenyl ester, cyclohexylcyclohexane, phenylpyrimidine or phenyldioxane, the skeleton is a tricyclic liquid crystal substance having cyclohexylbiphenyl as a skeleton and cyclohexylbiphenylcyclohexane as a skeleton. Although a tetracyclic liquid crystal substance has been known, a monocyclic liquid crystal substance is extremely rare, and a highly practical monocyclic liquid crystal substance has not been known.

In the case of a liquid crystal composition, the above-mentioned 2 is usually used.
A method of mainly adjusting a liquid crystal temperature range or the like by mainly using a cyclic liquid crystal substance and adding a tricyclic or tetracyclic liquid crystal substance thereto has been generally performed. However, these bicyclic, tricyclic and tetracyclic liquid crystal materials generally increase the cost because the manufacturing process becomes complicated as the number of rings increases, and the number of rings increases in terms of characteristics. According to
Generally, since the viscosity increases, the response speed of the display element tends to be slow. It is an object of the present invention to provide a novel monocyclic liquid crystal substance having a high practicability, which is useful for solving these problems, and a liquid crystal composition using the same.

[0004]

The object of the present invention is achieved by a benzene derivative represented by the general formula [I] in claim 1 and a liquid crystal composition containing the same.
R ¹ and R ² of the present invention include a hydrogen atom, a C _{1 to} C ₁₈ alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and a decyl group, a methoxy group, an ethoxy group, C ₁ -C ₁₈ alkoxy groups such as butoxy group, octyloxy group, decyloxy group, alkoxyalkyl groups such as methoxymethyl group, ethoxyethyl group, butoxyethyl group, methoxymethoxy group, ethoxyethoxy group, butoxyethoxy group, etc. Fluoroalkyl-substituted alkoxy groups such as alkoxyalkoxy groups, perfluoroethylmethoxy groups, perfluorobutylethoxy groups, perfluorohexylethoxy groups, halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, trifluoromethyl groups, trifluoromethoxy Group, cyano group, nitro group. The compound of the above general formula [I] of the present invention has the following general formula [II]

[0005]

[Chemical 2]

A benzoic acid derivative represented by the formula (wherein R ¹ and R ² have the same meanings as in the general formula [I]) and the following general formula [III] HO- (CH ₂ ) _m · Rf [ III] (in the formula, m and Rf have the same meanings as in formula [I]), and can be produced by reacting the alcohol derivative by a known method.

The benzene derivative of the present invention is described in "Liquid Crystal Device Handbook" P1 edited by 142nd Committee of Japan Society for the Promotion of Science.
07-192 (Nikkan Kogyo Shimbun) and the like, by mixing with various liquid crystal substances such as biphenyl-based, phenylcyclohexane-based, cyclohexylcarboxylic acid phenyl ester-based, and phenylpyrimidine-based compounds,
The liquid crystal composition can be adjusted.

Various additives such as an optically active substance such as cholesteryl nonanoate, an ultraviolet absorber, an antioxidant and a dichroic dye can be added to the liquid crystal composition of the present invention. By using the liquid crystal composition of the present invention, "Liquid Crystal Device Handbook", P303, edited by 142nd Committee, Japan Society for the Promotion of Science
˜386 (Nikkan Kogyo Shimbun) and the like, various display elements can be configured.

[0009]

The novel monocyclic liquid crystal compounds of the present invention and the liquid crystal composition using them can realize a liquid crystal display excellent in performance such as responsiveness at low cost.

[0010]

EXAMPLES Next, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. Example 1 3-Bromo-4-hexyloxybenzoic acid (2.0 g) and phosphorus pentachloride (1.4 g) were heated at 70 ° C. for 30 minutes, and phosphorus oxychloride was removed under reduced pressure to give 3-bromo-4-hexyl. Oxybenzoic acid chloride was obtained. 30 ml of this
The solution obtained by dissolving 3.1 g of 2-heptadecylfluorooctylethanol in 30 ml of pyridine was added dropwise to the solution dissolved in, and the mixture was heated at 90 ° C. for 8 hours with stirring.
After the reaction, the solvent was distilled off under reduced pressure, the product was purified by column chromatography using silica gel, and in the general formula [I], R ¹ was a bromine atom, R ² was a hexyloxy group, and m was 2, An oily target compound in which Rf is C ₈ F ₁₇ ;
3-Bromo-4-hexyloxybenzoic acid-2'-heptadecyl fluorooctyl ethyl ester was obtained. This compound had a liquid crystal region (monotropic) as shown in Example 2-16 in Table 1 below.

Example 2 By the method according to Example 1, the compounds shown in Table-I were obtained. In the table, I is an isotropic phase, S _A is a smectic A phase, S is a smectic phase other than the smectic A phase, C is a crystal phase, and parentheses represent a monotropic liquid crystal region.

[0012]

[Table 1]

Example 3 3-Bromo-4-hexyloxybenzoic acid-2'-heptadecyl fluorooctyl ethyl ester (Table I-No. 2-16 above) obtained in Example 1 was added at a concentration of 5 wt%. , Commercially available E.I. Merck mixed liquid crystal ZLI-113
2 (cyanophenylcyclohexane type) and ZLI-
Liquid crystal composition-I and liquid crystal composition-II were prepared by mixing with 4792 (fluorine type), and T _NI point (nematic-isotropic transition point) and viscosity (rotational viscometer method ... Measurement temperature: 19 ° C.) ) Was measured. The results are shown below.

[0014]

TABLE 2 ZLI-1132 liquid crystal composition -I T _NI (℃) 71 69.4 Viscosity (CP) 28 26 ZLI-4792 liquid crystal composition -II T _NI (℃) 91 90.0 Viscosity (CP) 15 11

Example 4 4-Nonyloxybenzoic acid-2'-heptadecyl fluorooctyl ethyl ester was prepared by a method similar to that of Example 1 and was prepared at a concentration of 5 wt% with commercially available E. By mixing the Merck Co. liquid crystal mixture ZLI-1132 (cyanophenyl cyclohexane-based) and ZLI-4792 (fluorine-based), respectively prepare a liquid crystal composition -III and the liquid crystal composition -IV, T _NI point (nematic - Iso Tropic transition point) and viscosity (rotary viscometer method ... Measurement temperature: 19 ° C)
Was measured.

[0016]

TABLE 3 ZLI-1132 liquid crystal composition -III T _NI (℃) 71 69.5 Viscosity (CP) 28 28.8 ZLI-4792 liquid crystal composition -IV T _NI (℃) 91 89.7 Viscosity (CP) 15 11.4

Claims (2)

[Claims] 1. The following general formula [I]: (In the formula, R ¹ and R ² are each independently a hydrogen atom, an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxyalkoxy group, a perfluoroalkylalkoxy group, a halogen atom, a trifluoromethyl group, a trifluoromethoxy group, a cyano group. group, a nitro group, m represents 1 or 2, a benzene derivative Rf represents a -C _n F _{2n + 1} or -C _n F _2n H, _n is represented by showing a 1-18.). 2. A liquid crystal composition comprising the benzene derivative according to claim 1.