JPS60184051A - Liquid crystal compound, liquid crystal composition and liquid crystal display element - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I or II (R is alkyl; R' is alkyl or alkoxymethyl; X, X', Y and Y' are group expressed by formula IIIor IV). EXAMPLE:4-n-Butylphenyl 4'-(trans-4''-n-pentylcyclohexyl)biphenyl-4-carboxylate. USE:A liquid composition and liquid crystal display element substance, having improved compatibility, and capable of improving the upper limit values of viscosity and liquid crystal temperature range without increasing the lower limit values thereof. PREPARATION:A compound expressed by the formula R-X-X'-Y-CN is reacted with phosphoric acid or sulfuric acid, etc. to give a carboxylic acid, which is then reacted with thionyl chloride to afford an acid chloride. The resultant acid chloride is then reacted with an alcohol to give the aimed compound expressed by formula I or II.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid crystal compound, a liquid crystal composition containing the liquid crystal compound, and a liquid crystal display element having the liquid crystal composition as a liquid crystal layer.

[Background of the invention]

Display devices using nematic liquid crystals have been put into practical use in various fields such as wristwatches and calculators. One such display device is now being realized, for example, for use as a display on an automobile instrument panel.

Therefore, as is widely known, automobile instrument panels must operate under all conditions, from cold regions to tropical regions, especially under a wide range of temperature conditions. Getting things is essential.

Incidentally, the liquid crystal composition that is mounted generally contains several types of liquid crystal compounds. Liquid crystal compositions are made by taking advantage of the characteristics of individual liquid crystal compounds, and meet the required performance. Among them, examples of liquid crystal compounds include C3H11HOQ HO3H.

Sm Me is known. This is used for the purpose of increasing the upper limit of the liquid crystal temperature range (the temperature at which the phase changes from a nematic phase to an isotropic liquid) in order to expand the liquid crystal temperature range of the liquid crystal composition.

However, when such a polycyclic liquid crystal compound is mixed with other liquid crystal compounds in an amount of 10% by weight or more, precipitation occurs and the liquid crystal composition no longer fulfills its function. Furthermore, as the mixing amount increases, the lower limit of the liquid crystal temperature range (temperature at which the phase changes from crystal to nematic phase) tends to increase significantly due to the viscosity, which is undesirable.

[Purpose of the invention]

The object of the present invention is to provide a liquid crystal compound that improves the lower limit of the liquid crystal temperature range and the upper limit of the liquid crystal temperature range without increasing the viscosity and has good compatibility with other liquid crystal compounds, and a liquid crystal composition using the same and a liquid crystal. An object of the present invention is to provide a display element.

[Summary of the invention]

To summarize the present invention, the first invention of the present invention relates to a liquid crystal compound, which has the following general formula I or 2: R-X-X'-Y-coo-y'-m .・α〕R-
x-coo-y-y-y'-* -(1) (in the formula, R represents an alkyl group, W represents an alkyl group or an alkoxymethyl group, and x, x', y and Y' are the same - or different,
It is characterized by being expressed as (indicates a group or aquifer).

Further, a second invention of the present invention relates to a liquid crystal composition, which contains the Ni oxide and at least one liquid crystal compound selected from the liquid crystal compounds represented by the above general formulas 1 and 1. It is characterized by

Furthermore, a third invention of the present invention relates to a liquid crystal display element, in which a liquid crystal layer is sandwiched between two opposing electrode substrates, and a voltage is applied between the electrode substrates to optically control the liquid crystal layer. In the liquid crystal display element that modulates the liquid crystal layer, the liquid crystal composition forming the liquid crystal layer is the liquid crystal composition according to the second aspect of the present invention.

The present inventors considered the molecular structure for compatibility and expansion of phase transition temperature. As a result, by introducing an ester group with a large polarization effect into the center of the conventional liquid crystal compound mentioned above, intermolecular interactions are more likely to occur in liquid crystals, and from the viewpoint of compatibility, the structure is made by sandwiching ester groups. A liquid crystal compound with an asymmetric number of rings (for example, the following formula: '5H1
The inventors have discovered that 1 (Gin() (a compound represented by shiOOO+Cj 3Hy) has improved properties overall, leading to the present invention.

The liquid crystal compound of the present invention is colorless and chemically stable.

The liquid crystal compound of the present invention can be synthesized by known methods using commercially available reagents. An example of a synthetic route using an esterification reaction is as follows. That is, R-X-X'-Y-ON-+R-X-X'-Y-(j
00H4R-X-X'-Y-Co(7/ +HO-'I
-Ff-+R-X-X'-Y-Co2-Y'-R'+
HO1 According to the liquid crystal compound of the present invention, it is possible to improve the upper limit of the liquid crystal temperature range without increasing the viscosity and the lower limit of the liquid crystal temperature range of a liquid crystal composition containing the compound. Moreover, the response characteristics of a liquid crystal display element using the composition are also improved.

[Embodiments of the invention]

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

The attached drawing is an infrared absorption spectrum diagram of an example of the liquid crystal compound of the present invention.

Example 1 4'-() lance-4'-n-pentylcyclohexyl)-4-cyanobiphenyl 20? ,85%
200 f of phosphoric acid and Sat sulfuric acid were charged and reacted at around 170°C for 30 hours.

After the reaction was completed, the reaction solution was poured into water and the precipitate was collected. After drying this and recrystallizing it from tetrahydrofuran, a
1-()Lance-41-n-pentylcyclohexyl)biphenyl-4-carboxylic acid is obtained. Yield 18f
(Yield: 85 cm) Next, add the above 4'-() lance- to the flask.
4'-n-hentylcyclohexyl)biphenyl-4-
Carboxylic acid 56f1 benzene 50- and several drops of pyridine were charged, and 5.7 t of thionyl chloride was dissolved in benzene 50- and added dropwise. After the dropwise addition was completed, the temperature was gradually raised and the mixture was aged at reflux temperature for 5 hours. After the reaction is completed, excess thionyl chloride and benzene are distilled off under reduced pressure to obtain a residue. When this is recrystallized from n-hexane, 41. ,-() Lance-41-n-
Pentylcyclohexyl)biphenyl-4-carboxylic acid chloride is obtained. Yield S, 3t (yield 90%
) The phase transition temperature of this compound was 105 to 171°C.

Next, add 2.3 f of p-n-propylphenol to 7 oz.
, 1.11F of pyridine, and 50% of benzene were charged, and 5.2f of the above 4'-(trans-4'-n-pentylcyclohexyl)biphenyl-4-carboxylic acid chloride dissolved in 100% of benzene was added dropwise. After the dropwise addition was completed, the temperature was gradually raised and the mixture was aged at reflux temperature for 5 hours. Then, he poured the reaction solution into water, separated the benzene layer, washed it with saturated brine, added about 200ml of ammonia water, separated the precipitated crystals in a furnace, and washed the filtrate with saturated brine until the liquid became neutral. Wash with water until dry, dry over anhydrous sodium sulfate, and distill off the benzene to obtain a residue. The desired product can be obtained by recrystallizing this into A7. Yield x3y (yield 5ochi) The infrared absorption spectrum of the compound obtained here is
As shown in the figure. In Figure 1, the absorption of 1740 crn-'' ester appears.In addition, it was confirmed that a molecular ion peak appears at m/e 468 in the mass spectrum.From these two facts and the relationship with the raw material compound, the The compound was confirmed to be 4-n-propylphenyl 4'-()2-,-,-,4-thylcyclohexyl]biphenyl-4-carboxylate, represented by the following formula.

In addition, the phase transition temperature of the compound with is 171-273-52
It was 0°C.

The compounds shown below can also be synthesized in a similar manner.

4-n-butylphenyl al-(trans-4'-n
-pentylcyclohexyl)biphenyl-4-carboxylate, 4-n-pentylphenyl 4'-(trans-4'-n-pentylcyclohexyl)biphenyl-
4-carboxylate, 4-n-hebutylphenyl a
l,, -() lance-4'-n-pentylcyclohexyl)biphenyl-4-carboxyle), 4-n-octylphenyl 4'-()2n-4'-n-pentylcyclohexyl)biphenyl-4-carboxy rate, 4-n-propylphenyl 4'-(trans-4'
-n-propylcyclohexyl)biphenyl-4-carboxylate, 4-n-pentylphenyl al, -(
) lance-4'-n-propylcyclohexyl)biphenyl-4-carboxylate, 4-! ll-octylphenyl 4'-()lans-4ζn-propylcyclohexyl)biphenyl-4-carboxylate, 4-n
-propylphenyl 4'-(trans-4'-n-hexylcyclohexyl)biphenyl-4-carboxylate), 4-n-hebutylphenyl 4'-(trans-
4'-n-hexylcyclohexyl)biphenyl-4-
Carboxylate, 4-n-octylphenyl 41.
, - () lance-4'-n-hexylcyclohexyl)bi722-4-carboxylate Other compounds represented by the above general formula can also be synthesized in the same manner.

Example 2 A flask is charged with 2.5 t of trans-4-n-7"ropylcyclohexanol, 1.2 f of pyridine, and 50-benzene. To this, 4'-()trans-
4'-n-pentylcyclohexyl)biphenyl-4-
5.2 f of carboxylic acid chloride was dissolved in 100 d of benzene and added dropwise.

After the dropwise addition was completed, the temperature was gradually raised and the mixture was aged under reflux for 6 hours.

After cooling, the reaction solution was poured into water, the benzene layer was separated, washed with saturated brine, about 2 ml of ammonia water was added, the precipitated crystals were separated, and the P solution was washed with saturated brine until the liquid was neutral. Wash with water until dry, dry over anhydrous sodium sulfate, and distill off the benzene to obtain a residue. This is recrystallized with acetone to obtain the desired product.

Yield: 2.0 SF (yield: 3 od) The infrared absorption spectrum of the compound thus obtained is shown in FIG. In FIG. 2, ester absorption appears at 1710 c7n-'. In addition, it was confirmed that a molecular ion peak appeared at m/e 474 in the mass spectrum.

Based on these two facts and the relationship with the starting materials, the compound synthesized here is trans-4-n-propylcyclohexyl 4J-(trans-4'-n-pentyl/chlorohexyl)biphenyl-4-carboxylate as shown in the following formula. It was confirmed that

8m The phase transition temperature of this compound is 113-218 Hg
The temperature was 27 q℃.

The compounds shown below can also be synthesized in a similar manner.

trans-4-n-butylcyclohexyl 4'-()lance-41-n-pentyl/chlorohexyl)biphenyl-4-carboxylate, trans-4-n-pentylcyclohexyl 4'-()lance-4'-n- pentylcyclohexyl)biphenyl-4-carboxylate, trans-4-n-heptyl 4'-()trans-4
1-n-pentylcyclohexyl)biphenyl-4-carboxylate, trans-4-n-octylcyclohexyl 4'L()trans-4'-n-pentylcyclohexyl)biphenyl-4-carboxylate, trans-4- n-propyl 4'-()lance-4'-n-
propylcyclohexyl) biphenyl-4-carboxylate, trans-4-n-pentylcyclohexyl
41-(trans-4'-n-propylcyclohexyl)biphenyl-4-carboxylate, trans-4-
n-octylcyclohexyl 4'-() lance-4'-
n-furobylcyclohexyl)biphenyl-4-carboxylate, trans-4-n-propylcyclohexyl 4'-()trans-4'-n-hexylcyclohexyl)biphenyl-4-carboxylate, trans-
4-n-hebutylcyclohexyl 4'-(trans-
4'-n-hexylcyclohexyl)biphenyl-4-
Carboxylate, trans-4-n-octylcyclohexyl 4'-(trans-4'-n-hexylcyclohexyl)biphenyl-4-carboxylate.

Other compounds represented by the above general formula can also be synthesized in the same manner.

Example 3 p-hydroxybenzyl alcohol 151F in flask
was prepared, and 50 ml of methanol was added to dissolve it. Add 0.0% hydrochloric acid to this. '5mg was added and aged at room temperature for 2 hours. After adding 250 mm of benzene to the reaction solution, the solution was washed with saturated brine until the washing solution became neutral, dried over anhydrous sodium sulfate, and several drops of relidine were added, followed by distilling off the benzene to obtain a residue.

When this is distilled under reduced pressure, p-methoxymethyl heptanoyl is obtained. Yield: 112 (yield: 66 cm) The boiling point of this product was 101-105°C, 10.6 tamHg, and the melting point was 81-84°C.

Next, add the above p-methoxymethylphenol 2.
4 f and 1.12 g of pyridine were charged, and 5 g of 4'-()lance-4'-n-pentylcyclohexyl)biphenyl-4-carboxylic acid chloride synthesized in Example 1 was dissolved in 5 g of benzene and added dropwise. After the addition was completed, the mixture was aged at room temperature for 12 hours. After that, the reaction solution was mixed with water; the benzene layer was separated, washed with saturated brine, added about 20% ammonia water, separated the precipitated crystals in a furnace, and washed the filtrate with saturated brine until the liquid became neutral. Wash with water until dry, dry over anhydrous sodium sulfate, and distill off the benzene to obtain a residue. This is recrystallized with acetone to obtain the desired product. Yield 14f (yield 23t) The infrared absorption spectrum of the compound thus obtained is shown in FIG. In Figure 3, absorption of ester appears at 1720 I:rn-''.In addition, it was confirmed that the molecular ion peak appears at m/θ470 in the mass spectrum.From these two facts and the relationship with the raw material compound, here The compound synthesized in is 4-methoxymethylphenyl represented by the following formula 4
It was confirmed to be '-()7-4ζn-pentylcyclohexyl)biphenyl-4-carboxylate.

In addition, the phase transition temperature of this compound is 170-269-31
The temperature was 8°C.

The compounds shown below can also be synthesized in a similar manner.

4-ethoxymethylphenyl 4'-() lance-4'
-n-pentylcyclohexyl)biphenyl-4-carboxylate), 4-n-propoxymethylphenyl
41. - () lance-4'-n-pentylcyclohexyl) and phenyl-4-carboxylate [The phase transition temperature of this compound was 164-269-289°C]
, 4-n-hebutyloxymethylphenyl 4'-(trans-41-n-pentylcyclohexyl)biphenyl-4-carboxylate, 4-methoxymethylphenyl 4'-(trans-4'-n-furobylcyclohexyl) Biphenyl-4-carboxylate, 4-ethoxymethylphenyl 4'-() lance-41-n-propylcyclohexyl) biphenyl-4-carboxylate, 4-n-butoxymethylphenyl 4'-() lance-4'- n-propylcyclohexyl)biphenyl-4-carboxylate, 4-methoxymethylphenyl 4'-() lance-4'-n-hexylcyclohexyl)biphenyl-4-carboxylate, 4-ethoxymethylphenyl 4'-( ) trans-4'-n-hexylcyclohexyl)biphenyl-4-carboxylate, 4-n-butoxymethylphenyl 4'-(trans-4'-n-hexylcyclohexyl)biphenyl-4
- Carboquine rate.

Other compounds represented by the above general formula can also be synthesized in the same manner.

Example 4 Put 1:), 2 t of magnesium chips into a flask, dissolve 4-bromobiphenyl 1172 in 100 ml of tetrahydrofuran, and raise the reaction temperature to 5 ml under a stream of dry nitrogen.
Keep it at around 0℃ and drop it for 30 minutes after the dripping is finished.
A solution of 4-biphenylmagnesium bromide in tetrahydrofuran was obtained by aging for a minute. To this ゛4
-n-pentylcyclohexanone 7'6f was dissolved in 200d of tetrahydrone run, and added dropwise while maintaining the reaction temperature at around 35°C. After the dropwise addition was completed, the reaction solution was poured into dilute hydrochloric acid, and the product was extracted with benzene. The benzene layer was washed with saturated brine until the washings became neutral, dried over anhydrous sodium sulfate, and the benzene was distilled off to obtain a residue. This is 4-(1'-hydroxy-4'-n-pentylcyclohexyl)biphenyl. Add 400 me of toluene and 102 lium of hydrogen sulfate to this, and make 1
A dehydration reaction was carried out at 10°C for 4 hours. For cooling costs, add 400% of toluene to the reaction solution, remove potassium hydrogen sulfate, wash the filtrate with saturated saline until the washings become neutral, dry with anhydrous sodium sulfate, and distill off the toluene. Get a residue. This was recrystallized from a mixed solvent of benzene and acetone and 4-(4'-n-pentylcyclohexene-1
-yl)biphenyl is obtained. Fit 89 f(
(Yield: 65%) Next, 15.2 f of the above 4-(4'-n-bentylcyclohexyl-1-cen-1-yl)biphenyl was mixed with 500 ml of ethanol together with 2.5 t of Raney nickel catalyst, and the hydrogen pressure was 40 ml. kg/'crn", reaction temperature 100-1
Catalytic reduction was performed at 40°C for 4 hours. During this time, hydrogen is 1.
15 was absorbed. The reaction solution and the silane nickel sample were separated in a furnace, and the ethanol was distilled off from the F solution to obtain a residue. Since the product obtained here was a mixture of the cis and trans forms of 4-(4'-pentylcyclohexyl)biphenyl, the trans form was isolated by repeated recrystallization from acetone. Yield: 3.7 f (yield: 24%) The melting point of this product was 96 to 97°C.

Charge 1Z42 of anhydrous aluminum chloride and 50ml of methylene chloride into a flask, and add 1Z42 of acetyl chloride at 5°C or less under water cooling.
0.2 F was added dropwise, and the mixture was aged for 1 hour after the addition was completed. To this, 30,6f of the above 4-(trans-4'-n-hentylcyclohexyl)biphenyl was added to 50 rn of methylene chloride.
and added dropwise at around 0°C. After completion of the dropwise addition, the mixture was aged for 2 hours, and the reaction solution was poured into dilute hydrochloric acid. Separate the methylene chloride layer, wash with saturated brine until the washings become neutral, dry over anhydrous sodium sulfate, and distill off the methylene chloride to obtain a residue. This is recrystallized from acetone to obtain sult-4'-()lans-4'-n-pentylcyclohexyl)-4-acetylbiphenyl. Yield 26.3 t (yield 7
5 H) The phase transition temperature of this product was 129-140e-212°C.

Add the above 14'-() lance-4'-n-pentylcyclohexyl)-4-a7tylbiphenyl 249 to the flask.
Prepare 200 ml of 8B thiformic acid, 100 ml of acetic anhydride,
1 mg of sulfuric acid! +50ml of hydrogen peroxide solution was added dropwise in this order. After completion of the dropwise addition, the mixture was aged at 50 to 60°C for 30 hours, and the reaction solution was poured into water.

The product was extracted with ether, washed with saturated brine, dried over anhydrous sodium sulfate, and the ether was distilled off to obtain a residue.

This is 4'-() lance-4'-n-pentylcyclohexyl)-4-7cetoxybiphenyl.

To this was added 50 mg of an aqueous solution of 300-140% isopropyl alcohol with a hydroxylating power of 1 Novum, and the mixture was reacted at reflux temperature for 4 hours. The reaction solution was poured into water and then acidified with hydrochloric acid to remove the precipitate. When this is recrystallized from chloroform, 4
'-() lance-41-n-pentylcyclohexyl)
-4-Hydroxybiphenyl I) E is obtained. Yield,
a t (Yield: 61 cm) Furthermore, the melting point of this product is 20
The temperature was 5-207°C.

2.7 f of 4-n-propylbenzoic acid in flask.

Add 5.7f thionyl chloride and 100 me benzene 5
Stir under reflux for an hour. Thereafter, excess thionyl chloride and benzene were distilled off under reduced pressure, and the residue was distilled under reduced pressure to obtain 4-n-propylbenzoic acid chloride.

Furthermore, in another flask, the above 4'-() lance-41-n
-pentylcyclohexy/l-) -4-human.

5.5 f of roxypiphenyl, 11 F of pyridine, and 50 of benzene were added, and 2.6 f of 4-n-propylbenzoic acid chloride obtained above was dissolved in 100 of benzene and added dropwise. After the dropwise addition was completed, the temperature was raised until the stopper was removed, and the mixture was aged at reflux temperature for 5 hours. Pour the reaction solution into water, separate the benzene layer, wash with saturated brine, add about 2 d of ammonia water, separate the precipitated crystals,
The furnace solution was washed with saturated brine until the washings became neutral, and then diluted with anhydrous sulfuric acid. Dry benzene was distilled off using IJum, and the residue was recrystallized from acetone to obtain the desired product.

The infrared absorption spectrum of the compound obtained here is shown in FIG. In FIG. 4, ester absorption appears at 1730 cm-'. In addition, it was confirmed that the molecular ion peak appeared at m/(346B) in the mass spectrum. Based on these two facts and the relationship with the raw material compounds, the compound synthesized here is 4'-() lance-41- shown by the following formula. n-bentylcyclohexyl)-4-biphenyl p-n-7
'Confirmed to be ropylbenzoate.

In addition, the phase transition temperature Fi187-193-3 of the compound with
The temperature was 31°C.

The compounds shown below can also be synthesized in a similar manner.

4'-() 5-4'-n-furobylcyclohexyl)-4-biphenyl p-n-7'' lobilbenzoate, 4'-()lan-41-n-butylcyclohexyl)-4-biphenyl p- n-propyl benzoate, 4'-()trans-41-n-butylcyclohexyl)-4-biphenyl p-n-propyl benzoate, 4'-(trans-4'-n-octylcyclohexyl)-4 -biphenyl p-n-propylbenzoate, 4'++ ()lance-4'-n-pentylcyclohexyl)-4-biphenyl p -' n
-butylbenzoate, 4'-(trans-4'-n
-pentylcyclohexyl)-4-biphenyl p-n
-pentyl benzoate, 41- (trans-4'-
n-pentyl 7-hexyl)-4-biphenyl p-
, rl-hebutylbenzoate, 4'-(trans-4
ζn-pentylcyclohexyl)-4-biphenyl p
-n-octylbenshade Other compounds represented by the above general formula can also be synthesized in the same manner.

Example 5 Flasconidlans-4-n-propylcyclohexanecarboxylic acid 2. sr, 5.7 t of thionyl chloride, and 100 tags of benzene were added, and the mixture was stirred under reflux for 5 hours. Thereafter, excess thionyl chloride and benzene were distilled off under reduced pressure, and the residue was subjected to vacuum MA to obtain trans-4-n-propylcyclohexanecarboxylic acid chloride.

Furthermore, in another flask, 4'-(trans-4'-n-pentylcyclohexyl)-4-hydroxybiphenyl 5.5F synthesized in Example 4 and pyridine 11y1 benzene 50- were added, trans-4- 2.71 g of n-propylcyclohexanecarboxylic acid chloride was dissolved in 100 g of benzene and added dropwise. After removing the cap, the temperature was raised to 500 ml, and the mixture was aged at a rapid flow temperature for 5 hours. Pour the reaction solution into water, separate the benzene layer, wash with ffl:10 brine, add about 2 ml of ammonia water, separate the precipitated crystals, and wash P solution with saturated brine until the liquid becomes neutral. Washed with water, dried over anhydrous (iI Un) sodium, distilled off benzene, and recrystallized the residue from acetone to obtain the desired product.

The infrared absorption spectrum of the compound obtained here is shown in FIG. In FIG. 5, ester absorption appears at 1750 crn-'. In addition, it was confirmed that a molecular ion peak appeared at m/e 474 in the mass spectrum. Based on these two facts and the relationship with the raw material compounds, the compound synthesized by Ren and Rel4'-() Lance-41-n-
It was confirmed to be pentylcyclohexyl)-4-biphenyl trans-4-n-propylcyclohexanecarboxylate.

In addition, the phase transition temperature of this compound is 218~e The temperature was 242-323°C.

The compounds shown below can also be synthesized in a similar manner.

4'-(trans-4'-n-furobylcyclohexyl)-4-biphenyl trans-4-n-propylcyclohexanecarboxylate, 4'-()y, X-4
'-n-butylcyclohexyl)-4-biphenyl trans-4-n-7'ropyrucyclohexanecarboxylate), 4'-()trans-4'-n-butylcyclohexyl)-4-biphenyl trans-4- n-probylcyclohegyzancarpoxylate), 4'-(),
lyn-4'-n-octylcyclohexyl)-4-
Biphenyl trans-4-n-7'ropyrcyclohexanecarboxylate, 4'-() trans-41-
n-pentylcyclohexyl)-4-biphenyl trans-4-n-butylcyclohexanecarboxylate, 4'-()trans-4'-n-pentylcyclohexyl)'-4-biphenyltrans-4-n-pentylcyclohexanecarboxylate ), 4'-() lance-4
'-n-pentylcyclohexyl)-4-biphenyl
trans-4-n-hebutyl cyclohexanecarboxylate), 4'-(t2ys-4'-n-pentylcyclohexyl)-4-piphenyl trans-4-n-octylcyclohexanecarboxylate.

Other compounds represented by the above general formula can also be synthesized in the same manner.

Example 6 An existing liquid crystal compound was added to the liquid crystal compound synthesized in Example 1.17 The liquid crystal temperature range and viscosity were measured. The results are shown in Table 1 along with other examples.

The liquid crystal composition according to this example shown in Section 1 below can improve the upper limit of the liquid crystal temperature range without increasing the lower limit of the viscosity and liquid crystal temperature range.

Example 7 An existing liquid crystal compound was added to the liquid crystal compound synthesized in Example 3, and the liquid crystal temperature range and viscosity were measured. The results are shown in Table 1. As shown in Table 1, the liquid crystal composition according to this example can improve the upper limit of the liquid crystal temperature range without increasing the lower limit of the viscosity or liquid crystal temperature range.

Example 8 A TN type liquid crystal display element was prepared by adding 10% by weight of the liquid crystal compound shown in Example 1 to the base liquid crystal shown in Example 6 as a liquid crystal layer. This liquid crystal display element has transparent NESA electrodes formed inside each of the upper and lower glass substrates, and an alignment control film of polyimide-isoindoquinazolinedione for aligning liquid crystal molecules. The gap between the upper and lower substrates was controlled to 5 so that the thickness of the liquid crystal layer was approximately 10 μm. When a voltage of 6V was applied to this liquid crystal display element at an ambient temperature of -3aC, the response time was 1.7
It was seconds.

Note that the response time of the comparative liquid crystal display element was 2.5 seconds under the same conditions.

Example 9 A TN type liquid crystal display element was prepared by adding 10% by weight of the liquid crystal compound shown in Example 3 to the base liquid crystal shown in Example 7 and pressing it in the same manner as in Example 8. When a voltage of 6 V was applied to the liquid crystal display element at an ambient temperature of -5 aC, the response time was 1.5 seconds. Note that the response time of the comparative liquid crystal display element was 2.5 seconds under the same conditions.

〔Effect of the invention〕

As explained above, according to the liquid crystal compound of the present invention,
It becomes possible to improve the upper limit of the liquid crystal temperature range without increasing the viscosity of the liquid crystal composition and the lower limit of the liquid crystal temperature range too much. Moreover, a liquid crystal composition containing this compound improves the response characteristics of a liquid crystal display element.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 5 are infrared absorption spectrum diagrams of examples of the liquid crystal compound of the present invention. Patent applicant Hiroshi Nakamoto of Hato Hitachi, Ltd. and Kanto Kagaku Co., Ltd.

Claims (1)

[Claims] 1. The following general formula 1 or ■: R-z -x'-y -coo -Y'-R'...
[υR-x-coo-x'-y-y'-* =-(IQ
(In the formula, R represents an alkyl group, W represents an alkyl group or an alkoxymethyl group, and represents x, x', or () group). 2. The number of carbon atoms in each of the alkyl groups is 1 to 1.
8. The liquid crystal compound according to claim 1, wherein the number of liquid crystal compounds is 8. 3. The following general formulas I and ■: R-X-X'-Y-Coo-7-K...α]n-x
-coo-x'-y-y'-f...(6) (in the formula R
represents an alkyl group, W represents an alkyl group or an alkoxymethyl group, and % In a liquid crystal display element in which a liquid crystal layer is sandwiched between electrode substrates, and a voltage is applied between the electrode substrates to optically modulate the liquid crystal layer, the liquid crystal composition forming the liquid crystal layer has the following general formula 1. and ■: n-x-x'-y-coo-y'-* ... [υR-
X-Coo-X'-Y-Y'-R'...[phantom (in the formula, R represents an alkyl group, W represents an alkyl group or an alkoxymethyl group, and X, G, Y and Y' are A liquid crystal display element characterized in that it is a liquid crystal composition having the same or different liquid crystal compositions.