JPS60237048A - Ester compound - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R represents 1-10C alkyl or alkoxyl; X represents H or methyl; Y represents F or Cl). EXAMPLE:4-Fluorophenyl 4-[3-(4-butoxyphenyl)propanoyloxy]benzoate. USE:A liquid crystal display element, capable of increasing optical anisotropic values, decreasing driving voltage, and having good compatibility with other liquid crystal substances (ester type, Schiff's base type, biphenyl type, phenylcyclohexane type, heterocyclic type, etc.). PREPARATION:4-Hydroxybenzoic acid of formula II and a 4-halogenophenol of formula III are reacted in xylene using boric acid and sulfuric acid as a catalyst to obtain a 4-halogenophenyl 4-hydroxybenzoate of formula IV, which is then reacted with the corresponding carboxylic acid chloride of formula V in the presence of pyridine to obtain the compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel ester compound and a liquid crystal composition containing the compound.

Display elements using liquid crystals are widely used in watches, calculators, etc. These liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal materials, and the liquid crystal phases include nematic liquid crystal phase, smectic liquid crystal phase, and cholesteric liquid crystal phase. Most widely put into practical use. These include TN (twisted nematic) type, DB (dynamic scattering) type, guest-host type, D
There are display elements such as AP type, and the properties required of the liquid crystal materials used for each type are different. It is desirable that the liquid crystal materials used in these display elements exhibit a liquid crystal phase over as wide a natural temperature range as possible. At present, there is no single material that satisfies such conditions, and several liquid crystal materials or non-liquid crystal materials are mixed and put into practical use. These substances are required to be stable against moisture, light, heat, air, etc., and the threshold voltage required to drive the display element,
The car is heavier if the saturation voltage is as low as possible.

A liquid crystal composition with a large optical anisotropy value (hereinafter abbreviated as Δn) can suppress the occurrence of color unevenness due to local unevenness in the distance between the substrates of a liquid crystal display element, and can reduce the distance between the substrates. A compound with a large Δn is desirable since it has the advantage of increasing the electric field strength even with a voltage. An object of the present invention is to provide a novel liquid crystal compound useful as a component of a liquid crystal composition suitable for such uses.

That is, the present invention is based on the general formula (in the above formula, R is an alkyl group having 1 to 10 carbon atoms or a flufoxy group, X is H'' or a methyl group, and Y is F or (J
This is a liquid crystal composition characterized by containing an ester compound and the compound represented by

The compound of the present invention has good compatibility with many other liquid crystal compounds, such as ester, Schiff base, biphenyl, phenylcyclohexane, and heterocyclic compounds, and the compound of the present invention can be used in liquid crystal compositions. By adding a small amount of the compound, Δn can be increased, and the driving voltage of a liquid crystal display device using the liquid crystal composition can be lowered.

An example of the method for producing the compound of the present invention is shown below (in the above formula, R, X and Y are the same as above), first, W, w
, Lovrance, Jr.: Tetrahed
Ron Letters, 3453 (1971), 4-hydroxybenzoic acid (compound (■)) and 4-halogenophenol (compound (Ill)) were reacted in xylene with boric acid and sulfuric acid as catalysts to form 4- Hydroxybenzoic acid-4-halogenophenyl ester (compound 叡)) is produced. This is then reacted with the corresponding carboxylic acid chloride (compound (■)) in the presence of pyridine to produce the desired ester compound (1).

The compounds of the present invention will be explained in more detail below using Examples.

Example 1 Preparation of 4-(3-(4-butoxyphenyl)propanoyloxy)benzoic acid-4-fluorophenyl ester (1)' 4-hydroxybenzoic acid-fluorophenyl ester (compound QV)) Benzoic acid (compound (II)) 138
t and 4-fluorophenol (compound (Ill))
Put the lso y into a No. 21 Mitsuro flask, attach a stirrer and a moisture meter, then add 1.2 tons of xylene, 12.4 tons of boric acid, and 16.6 tons of sulfuric acid, and heat to reflux while stirring. did. Refluxing was continued until no water distilled into the water meter (20 hours). After the reaction was completed, xylene was removed with O and BIM under reduced pressure, and the precipitated crystals were cooled to 5-room temperature. Shian,
IL fragrant-4-fluorophenyl ester (compound (M
) was obtained.

(2) Esterification The above-mentioned 4-hydroxybenzoic acid-4-fluorophenyl ester (compound (IV) > 2.3 fc0010
mol) in pyridine 10-, and while stirring, β-(
2.3 t (0,095 mol) of 4-butoxyphenyl)propionic acid chloride (compound (V)) was added. After the reaction was left in the apparatus overnight, 50ml of toluene was added and the mixture was poured into water. The toluene layer separated into layers was mixed with 6N hydrochloric acid and 2N
It was washed with a sodium hydroxide solution and then with water, and finally dried using anhydrous sodium sulfate. Next, toluene was distilled off under reduced pressure to obtain an oil, which was recrystallized using ethanol to obtain the target product, 4-[β-(4-butoxyphenyl)propanoyloxy]benzoic acid-4- 3.9 y (0,0089 mol) of fluorophenyl ester was obtained. The melting point Fi of this product was 120.5°C, and the nematic-isotropic liquid phase transition point (hereinafter abbreviated as NI point) was 107.0°C.

Examples 2 to 5 The desired ester compound ( 1) was manufactured. The physical properties of these compounds are shown in Table 1 together with the results of Example 1.

In the table, C, S, N, and I respectively indicate a crystalline phase, a smectic phase, a nematic phase, and an isotropic liquid phase. Represents the tropic transition point.

Example 6 (Application example) The N-I point of the liquid crystal composition (A) having the following composition is 52.1°C,
The dielectric anisotropy value (hereinafter abbreviated as Δε) is 11.2, Δn
is 0.119. As a liquid crystal cell, substrates having silicon oxide coated and rubbed tin oxide transparent electrodes were assembled to face each other, and the distance between the electrodes was 10 μm.
Prepare a liquid crystal composition, fill it with the liquid crystal composition (A) described above, and
When we measured its characteristics at 0°C, we found that the threshold voltage (hereinafter v
th) is 1.54V, and the saturation voltage (hereinafter referred to as Vsa) is 1.54V.
(abbreviated as t) was 2.13V.

A liquid in which 5% by weight of 4-[β-(4-butoxyphenyl)propanoyloxy)benzoic acid 8-4-fluorophenyl ester prepared in Example 1 of the present invention was dissolved in 955% by weight of this liquid crystal mixture (A) was added. N- of product (B)
Point I was 53.0°C, 6g was 114, and Δn was 0.120. Regarding the characteristics of the same liquid crystal cell as described above using the liquid crystal composition (B), vth is 1.43 V, V
sat is 2. OIV and OIV decreased significantly.

that's all Patent applicant Chisso Corporation Agent: Patent Attorney Yatabe Sasai Same as above Katsuhiko Nonaka 9-

Claims (2)

[Claims] (1) An ester compound represented by the general formula (in the above formula, R is an alkyl group or an alkoxy group having 1 to 10 carbon atoms, X is an H-box or a methyl group, and Y is F or UCt). (2) General formula (in the above formula, RFi is an alkyl group having 1 to 10 carbon atoms or #'
1. A liquid crystal composition comprising an ester compound represented by the following formula: i alkoxy group, XFiH or methyl group, Y represents F or C1.