JPH03220147A - Bicyclic alkylene glycol derivative - Google Patents

Abstract

NEW MATERIAL:A bicyclic alkylene glycol derivative of formula I (R<1>, R<2> are 1-7C linear chain alkyl; (m) is 0, 1; (n) is 1-7; group of formula II is trans- cyclohexane ring). USE:Useful as an electrooptical display material. The compound of formula I exhibits a vertically orienting property, has good compatibility with a compound of formula III (R<1>, R<2> are linear chain alkyl) having an effect on increasing the pre-tilt angle of STN-LCD. The mixed liquid crystal has a vertically orienting property, and further can raise the pre-tilt angle, thereby useful for preparing STN-LCD(super.twisted.nematic liquid crystal display device) (the STN-LCDs are widely employed for the displays of highly precise information processors such as word processors). PREPARATION:As shown in the reaction equations, a compound of formula IV is subjected to a reaction with a compound of formula V to provide the compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to bicyclic alkylene glycol derivatives useful as electro-optical display materials, and liquid crystal compositions and liquid crystal display devices containing these compounds.

[Conventional technology]

A typical liquid crystal display cell is a TN-LCD (twisted nematic liquid crystal display), which is used in watches, calculators, electronic notebooks, pocket computers, word processors, personal computers, and the like. In recent years, the amount of information displayed on a single screen has increased with the increase in information processed by OA equipment. Conventional TN-LCDs are particularly suited for high-end applications such as word processors and personal computers in terms of display quality such as contrast and viewing angle. It is no longer possible to meet the demands of time-division driving.

In this situation, Scheffer
etc. (510' 85 Digest, P120 (1
985)) or Kinugawa et al. (SID' 86 Dig
est, P122 (1986)) by STN
(Super twisted nematic) LCDs have been developed and are beginning to be widely used as displays for high information processing applications such as word processors and personal computers.

In a 5TN-LCD, control of the angle between the alignment plane and the liquid crystal molecules, that is, the pretilt angle, is an important factor that greatly affects the yield and the like in manufacturing the liquid crystal display cell.

For orientation, a method is known in which the pretilt angle is controlled to a high tilt angle of about 20' by oblique vapor deposition of SiOx, but more practically, for example, "Sunever 150" manufactured by Nissan Chemical Co., Ltd. A method of controlling the pretilt angle to about 5@ by rubbing an organic film is known. In addition, various organic films have been developed and are used by controlling the pretilt angle to 5 to 10" using a rubbing method. The higher the pretilt angle, the less likely stripe domains will occur, and Although it is known that the yield rate when manufacturing display cells is improved, it is currently extremely difficult to use the rubbing method to create a stable alignment film with a constant pretilt angle of 5° to 10''. It is.

[Problem to be solved by the invention]

Under these circumstances, the inventors proposed a separate invention in which a liquid crystal compound represented by the formula (R1 and R2 each independently represents a linear alkyl group) exhibits vertical alignment, and 5TN-
It has been found that this method has the effect of increasing the pretilt angle of an LCD.

However, due to the constraints of producing a practical liquid crystal that exhibits a nematic phase at room temperature, the compound of formula (1) can only be contained in a maximum of about 30% in the mixed liquid crystal.
As a result, the mixed liquid crystal did not exhibit vertical alignment.

The problem to be solved by the present invention is to provide a novel liquid crystal compound that has good compatibility with the compound of formula (1) and maintains the vertical alignment of the compound of formula (1), and to provide a novel liquid crystal compound containing these compounds. Approximately 5", which allows a practically stable alignment film to be created by rubbing a nematic liquid crystal composition in terms of quality.
A pretilt angle higher than 5° can be formed by encapsulating the liquid crystal display cell in a liquid crystal display cell with a pretilt angle of 5°.
The objective is to produce a TN-LCD.

[Means to solve the problem]

In order to solve the above problems, the present invention provides the general formula (wherein,
R' and R2 each independently represent a linear alkyl group having 1 to 7 carbon atoms, m represents O or 1, and n represents 1 to 7.
represents an integer of 7 and can be produced according to the law.

Each represents the same thing as that of formula (II). )formula(
A compound of formula (n) is prepared by reacting a compound of formula (III) with a compound of formula (IV) in an ethereal solvent such as tetrahydrofuran in the presence of a strong base such as sodium hydride.

Table 1 lists the phase transition temperatures of representative compounds of formula (II) according to the present invention thus produced.

Provides a compound represented by

The compound of formula (II) according to the present invention can be prepared by the following method. ■ table (In the table, C represents a crystalline phase, and ■ represents an isotropic liquid phase.

) Preferred representative examples of liquid crystal compounds that can be used in combination with the compound of formula (II) include 4-substituted benzoic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted phenyl ester, etc. , 4-substituted cyclohexanecarboxylic acid 4'-substituted biphenyl ester, 4-(4-substituted cyclohexanecarbonyloxy)benzoic acid 4'-substituted phenyl ester, 4 (4
K-substituted cyclohexyl)benzoic acid 4'-substituted phenyl ester, 4-(4-substituted cyclohexyl)benzoic acid 4''-substituted cyclohexyl ester, 4-substituted 4'-substituted tA biphenyl, 4-substituted phenyl-4'-substituted cyclohexane, 4 Examples include -substituted 4"-substituted terphenyl, 4-substituted biphenyl, 4'-substituted cyclohexane, and 2-(4-substituted phenyl)-S-substituted pyrimidine.

In order to examine the compatibility of the compound of formula (II) and the compound of formula (1), a mixed liquid crystal (A) consisting of 50% by weight of the compound of Nα1 and 50% by weight of the representative compound of 2(I) was prepared. did.

As shown in Table 1, the compound of Nα1 is liquid at room temperature, and compound (a) has a nematic phase at 169 to 196°C, but mixed liquid crystal (A) has a nematic phase at 57 to 77°C. It showed a nematic phase even at room temperature in a supercooled state. No. 1 because of the remarkable decrease in the lower limit temperature of the nematic phase.
It can be understood that the compounds of , l and compound (a) have extremely good compatibility.

Furthermore, 80% by weight of the mixed liquid crystal (A) and the mixed liquid crystal (B)
When a room temperature nematic phase crystal consisting of 20% by weight of 20% by weight was sealed in a liquid crystal display cell that had not been subjected to alignment treatment, uniform vertical alignment was confirmed.

In addition, the mixed liquid crystal (B) as well as Its physical properties are as follows.

N-1 transition degree 56.5°C viscosity (20
”C) 20.5 c, p.

Refractive index anisotropy (Δn) 0.094 Dielectric anisotropy (Δε) 5.8 Threshold voltage 1.65V Table 2 shows mixed liquid crystals (
It is said that a mixed liquid crystal consisting of 60% by weight of C), 20% by weight of compound (a) of formula (I), and 20% by weight of Nα1 compound of formula (n) forms a pretilt angle of about 5°. An alignment film made by rubbing an organic film of ``Sunever 150'' manufactured by Kagaku Kagaku was sealed in a liquid crystal display cell in which the upper and lower sides were antiparallel, and the pretilt angle measured by the magnetic field potential method was displayed and mixed for comparison. Similarly, a mixed liquid crystal consisting of the liquid crystal (C) itself, 60% by weight of the mixed liquid crystal (C), 20% by weight of the compound (a), and 20% by weight of the compound (b) having a similar structure to the compound of formula (n). It shows the pre-tilt angle of the enclosed image.

In addition, the mixed liquid crystal (C) Its physical properties are as follows.

54.5°C 21, Oc, p.

0.0917 6.5 1.60ν It consists of N-I transition temperature Viscosity (20°C) Anisotropy of refractive index (Δn) Dielectric anisotropy (Δε) threshold voltage Furthermore, compound (b) has the formula It is a compound represented by

(C) (c) + (a) + N(Ll (c + a) + (b 4.8m 6.7” 6.0@ From the data posted in Table 2, the mixture containing compound (a) All liquid crystals increase the pretilt angle by 1 degree or more, but the mixed liquid crystal containing compound No. 1 of the present invention can increase the pretilt angle to a greater degree than the mixed liquid crystal containing the structurally similar compound (b). it is obvious.

Example 1 Recrystallization and purification yielded 15.3 g (0.06 g) of the following compound.
mole) was obtained.

Melting point 3°C Example 2 23.2g (0.1 mol) was dissolved in tetrahydrofuran 18
4.8 g of sodium hydride (containing 60% by weight in oil) dissolved in 0 ml of water and cooled to 15-20°C.
0.12 mol) was added thereto, and the mixture was stirred at room temperature for 1 hour. To this reaction mixture was added 9.7 g of a compound of formula CI CHzOCHs (
0.12 mol) was added dropwise over 15 minutes, and the mixture was further reacted at room temperature for 5 hours. After the reaction was completed, 80 tan of 9% hydrochloric acid was added, and the reaction product was mixed with 70/! of ethyl acetate. Extracted three times. After washing the extract with water and drying, the solvent was distilled off under reduced pressure, and the resulting residue was used to prepare a mixed liquid crystal consisting of methanol.
The results of measuring the physical properties were as follows.

N-1 transition degree 62.8°C viscosity (20
°C) 22.5 c, p.

Anisotropy of refractive index (Δn) 0.090 Dielectric anisotropy (Δε) 4.3 Threshold voltage (V) 1.84 Antiparallel made by rubbing this mixed liquid crystal with "Sunever 150" The pretilt angle measured in the liquid crystal display cell was 6.8°.

〔Effect of the invention〕

The compound of formula (II) according to the present invention is extremely compatible with the compound of formula (I) according to another invention, and the liquid crystal mixture thereof has vertical alignment. Furthermore, formula (n)
When a nematic liquid crystal composition containing a compound of formula (r) and a compound of formula (r) is mixed with a normal nematic liquid crystal composition, it can be sealed in a liquid crystal display cell having an alignment film forming a pretilt angle of about 5°. By doing so, the pretilt angle can be increased to a greater extent than a nematic liquid crystal composition containing a structurally similar compound and the compound of formula (1).

Therefore, the compound of formula (n) according to the present invention is 5TN-L
It is extremely useful for producing CDs.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 and R^2 each independently represent 1 to 1 carbon atom.
7 represents a straight chain alkyl group, m represents 0 or 1, n represents an integer from 1 to 7, ▲ Numerical formulas, chemical formulas, tables, etc. are available. ▼ represents a cyclohexane ring in trans configuration. ) A compound represented by 2. A nematic liquid crystal composition containing the compound according to claim 1. 3. A super twisted nematic liquid crystal display device using the nematic liquid crystal composition according to claim 2.