JP2856175B2 - Liquid crystal additive, liquid crystal composition and liquid crystal display device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal additive, a liquid crystal composition used for an electro-optical liquid crystal display, and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art Liquid crystal displays have been put to practical use as display devices not only for conventional watches and calculators but also for portable terminals, notebook PCs and workstations, and their applications are expanding. As performance requirements for these applications, a high-speed responsive liquid crystal display capable of reproducing and displaying high-definition moving images is required.

In order to realize a display capable of supporting a high-definition moving image, the speed of a liquid crystal display element constituting the display must be increased,
That is, a liquid crystal composition capable of high-speed response is required. At present, as an effective means for obtaining a liquid crystal composition capable of high-speed response, a fluorine-substituted compound in which a fluorine atom is introduced into a side chain and a terminal of a cyclic compound (phenyl group, cyclohexyl group, etc.) as a compounding component of the liquid crystal composition is used. Is being developed. As an example, the Proceeding of SPIE Conference of E. Merck (V.M.
Reiffenrath et. al. Proc.
of SPIEConference (1990) p8
From 4), fluorine-substituted tolan compounds have been reported.

On the other hand, as another means for obtaining a liquid crystal composition capable of high-speed response, an organic silicon compound having a silicon atom has been developed. An example of the development is silacyclohexane described in Japanese Patent Application Laid-Open No. 7-70148 of Shin-Etsu Chemical, "Silacyclohexane Compound, Production Method and Liquid Crystal Composition Containing It". Although this compound is said to be effective as a compounding component of a liquid crystal composition capable of high-speed response, no specific numerical value of the response time has been reported.

[0005]

The liquid crystal display is currently used as a portable terminal, including conventional clocks and computer display devices, and has applications to various products, and its use is expanding. As the demand for liquid crystal materials increases, it is becoming more stringent. In order to realize a liquid crystal display capable of displaying high-definition moving images, it is necessary to increase the speed of the liquid crystal composition. However, the above-mentioned conventional compounds have not been able to achieve a sufficiently high speed.

An object of the present invention is to provide a liquid crystal additive and a liquid crystal composition for obtaining a liquid crystal display device capable of high-speed response.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a liquid crystal additive comprising an organosilicon compound having a silicon atom having two cyclic substituents; The inventors have found that a liquid crystal composition composed of a nematic composition or a smectic liquid crystal composition is excellent in high-speed response, and have reached the present invention.

That is, in the present invention, the organic silicon compound comprising a silicon atom having two cyclic substituents is a silicon compound represented by the general formula (1) (provided that
In the formula, A and B are each independently preferably a cyclic substituent having 3 to 10 carbon atoms, and X and Y are each an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxyl group, Halogenated alkoxyl group, or halogen atom, hydrogen atom, hydroxyl group, cyano group).

[0009]

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Examples of such a compound include, but are not particularly limited to, a silicon compound represented by the following formula.

[0011]

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From the viewpoint of compatibility, the cyclic substituent A,
At least A is -C _n H _{2n +1,} -OC of B
_{n H 2n + 1, -F,} -Cl, -Br, -I, -OH, -C
It preferably has a substituent selected from F ₃ and —CN (where n is an integer of 0 to 10), and examples thereof include the following. In consideration of further compatibility, it is preferable that both A and B have the above substituents.

[0013]

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Further, from the viewpoint of high-speed response, both the cyclic substituents A and B are 1,4-phenyl groups or 1,4-cyclohexyl groups, and it is preferable that these have substituents. These include, for example, silicon compounds represented by the following formula.

[0015]

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In addition, from the viewpoints of chemical stability and high-speed response, it is more preferable that X and Y are methyl groups. The following equation is an example of this.

[0017]

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The liquid crystal composition of the present invention preferably contains 1 to 50% by weight of any one of the above-mentioned silicon compounds with respect to the base liquid crystal composition. When the amount of the silicon compound exceeds 50% by weight, the compatibility with the parent liquid crystal composition is significantly reduced. Further, in a liquid crystal composition containing 1% by weight or less of the silicon compound,
There is almost no improvement in response speed. For this reason, it is preferable that the composition ratio contains 1 to 50% by weight of any of the above silicon compounds with respect to the base liquid crystal composition.

The liquid crystal composition of the present invention has excellent high-speed response and can be used as a liquid crystal display device.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to each embodiment, but the present invention is not limited to the following embodiments unless departing from the scope.

[0021]

【Example】

Example 1 Synthesis of dimethyl (cyclohexyl) phenylsilane

[0022]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and bromobenzene (5 g, 0.032 mol) and anhydrous diethyl ether (50 ml) were added thereto.
0.0ml, 0.032mol) was slowly added dropwise.
After stirring for hours, phenyllithium was produced by a Br-Li exchange reaction. Chlorocyclohexyldimethylsilane (5.6 g, 0.032 mol) is slowly dropped into the obtained reaction solution, and the mixture is heated at -78 ° C for 2 hours, heated to room temperature, and stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound (dimethyl (cyclohexyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. The structural analysis of the compound was performed by 1H, 13C-NMR spectrum analysis and elemental analysis. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 2 Dimethyl (cyclopentyl)
Synthesis of phenylsilane

[0025]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and cyclopentyl bromide (5 g, 0.034 mol
l), anhydrous diethyl ether (50 ml) was added, and -7 was added.
While stirring at 8 ° C., a n-butyllithium / n-hexane solution (21.0 ml, 0.034 mol) was slowly dropped, and the mixture was stirred for 3 hours to produce a cyclopentyllithium by a Br—Li exchange reaction. Chlorophenyldimethylsilane (5.8 g, 0.034 g) was added to the obtained reaction solution.
mol) was slowly added dropwise, and the mixture was heated at -78 ° C for 2 hours, heated to room temperature, and stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound (dimethyl (cyclopentyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. 1H, 13C-NMR for structural analysis of the compound
The analysis was performed by spectral analysis and elemental analysis. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 3 Dimethyl (4-chlorophenyl) phenylsilane

[0028]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 4-bromochlorobenzene (5 g, 0.026 mol
l), anhydrous diethyl ether (50 ml) was added, and -7 was added.
While stirring at 8 ° C., an n-butyllithium / n-hexane solution (16.5 ml, 0.026 mol) was slowly dropped, and the mixture was stirred for 3 hours to produce a chlorophenyllithium by a Br-Li exchange reaction. Chlorophenyldimethylsilane (4.4 g, 0.026 g) was added to the obtained reaction solution.
mol) was slowly added dropwise, and the mixture was heated at -78 ° C for 2 hours, heated to room temperature, and stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound (dimethyl (4-chlorophenyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. The structural analysis of the compound was performed by 1H, 13C-N
It was performed by MR spectrum analysis and elemental analysis. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 4 Dimethyl (4-cyanophenyl) phenylsilane

[0031]

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This compound was synthesized according to the above reaction route. The dry 200 ml three-necked flask was purged with argon, and 4-bromobenzonitrile (5 g, 0.027 mol
l), anhydrous diethyl ether (50 ml) was added, and -7 was added.
While stirring at 8 ° C., an n-butyllithium / n-hexane solution (17.0 ml, 0.027 mol) was slowly dropped, and the mixture was stirred for 3 hours to produce lithium benzonitrile by a Br-Li exchange reaction. Chlorophenyldimethylsilane (4.5 g, 0.027 g) was added to the obtained reaction solution.
mol) was slowly added dropwise, and the mixture was heated at -78 ° C for 2 hours, heated to room temperature, and stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound (dimethyl (4-chlorophenyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. The structural analysis of the compound was performed by 1H, 13C-N
It was performed by MR spectrum analysis and elemental analysis. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 5 Synthesis of dimethyl (4-butylphenyl) phenylsilane

[0034]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 1-bromo-4-butylbenzene (5 g, 0.02
3 mol) and anhydrous diethyl ether (40 ml), and stirred at −78 ° C. while n-butyllithium / n
A hexane solution (14.6 ml, 0.023 mol) was slowly added dropwise, and the mixture was stirred for 3 hours to produce p-butylphenyl lithium by a Br-Li exchange reaction. Chlorophenyldimethylsilane (3.91) was added to the obtained reaction solution.
g, 0.023 mol) was slowly added dropwise, and the mixture was heated at -78 ° C for 2 hours, room temperature and stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, and then hexane was added.
The mixture was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound (dimethyl (4-butylphenyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. The structural analysis of the compound
This was performed by 1H, 13C-NMR spectrum analysis and elemental analysis. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 6 Synthesis of dibutyl (4-butylphenyl) phenylsilane

[0037]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 1-bromo-4-butylbenzene (5 g, 0.02
3 mol) and anhydrous diethyl ether (40 ml), and stirred at −78 ° C. while n-butyllithium / n
A hexane solution (14.6 ml, 0.023 mol) was slowly added dropwise, and the mixture was stirred for 3 hours to produce p-butylphenyl lithium by a Br-Li exchange reaction. Dichlorodibutylsilane (2.51 g,
0.0012 mol) was slowly added dropwise at -78 ° C.
Heat to room temperature and stir for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product.
Then, the reaction solution was concentrated, and the target silicon compound (dibutyl (4-butylphenyl) phenylsilane) was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. The structural analysis of the compound
H, 13C-NMR spectrum analysis and elemental analysis were performed. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 7 Synthesis of dimethyl [di (4-butylphenyl)] silane

[0040]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 1-bromo-4-butylbenzene (5 g, 0.02
3 mol) and anhydrous diethyl ether (40 ml), and stirred at −78 ° C. while n-butyllithium / n
A hexane solution (14.6 ml, 0.023 mol) was slowly added dropwise, and the mixture was stirred for 3 hours to produce p-butylphenyl lithium by a Br-Li exchange reaction. Dichlorodimethylsilane (1.52 g,
0.0118 mol) was slowly added dropwise at -78 ° C.
Heat to room temperature and stir for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product.
Then, the reaction solution is concentrated, and the desired silicon compound, dimethyl [di (4-butylphenyl)] is distilled off under reduced pressure.
The silane was isolated. The compound was purified by repeating vacuum distillation several times. Structural analysis of the compound was performed using 1H, 1
This was performed by 3C-NMR spectrum analysis and elemental analysis.
The 1H-NMR spectrum of this compound is shown in FIG.
The NMR spectrum is shown in FIG. From the 1H-NMR spectrum, a proton peak derived from a methyl group on a Si atom specific to the target compound was observed at 0 ppm, a proton peak derived from a benzene ring was observed at around 7.1 ppm, and the product was found to be dimethyl [di (4- Butylphenyl)] silane. On the other hand, from the 13C spectrum, a carbon peak derived from a methyl group on a Si atom peculiar to dimethyl [di (4-butylphenyl)] silane is observed at around 6 ppm, and a carbon peak derived from a benzene ring is observed at around 120 ppm. Is bis (butylphenyl) dimethylsilane. The compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 8 Synthesis of dimethyl [di (4-cyclohexyl)] silane

[0043]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 1-chloro-4-butylcyclohexane (5 g,
0.0356 mol), anhydrous diethyl ether (40 m
l) and stirring at −78 ° C., while stirring the n-butyllithium / n-hexane solution (22.3 ml, 0.0356).
mol) was slowly added dropwise and stirred for 3 hours to produce p-butylcyclohexyllithium. Dichlorodimethylsilane (2.3 g, 0.0178) was added to the obtained reaction solution.
mol) was slowly added dropwise at −78 ° C., the temperature was raised to −78 ° C. for 2 hours, and the mixture was stirred for 1 hour. The reaction solution was filtered through a glass filter, concentrated, hexane was added, the solution was filtered again through a glass filter, and this operation was repeated several times to remove lithium chloride as a by-product. Then, the reaction solution was concentrated, and the target silicon compound, dimethyl [di (4-cyclohexyl)] silane, was isolated by distillation under reduced pressure. The compound was purified by repeating vacuum distillation several times. 1H, 13C structural analysis of compounds
As a result of -NMR spectrum analysis, it was confirmed that the produced compound was dimethyl [di (4-cyclohexyl)] silane. This compound was a colorless and transparent liquid and did not exhibit liquid crystallinity. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

Example 9 Synthesis of dimethyl [di (4-butyl2,3,5,6-tetrafluorophenyl)] silane

[0046]

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This compound was synthesized according to the above reaction route. The dried 200 ml three-necked flask was purged with argon, and 1-butyl-2,3,5,6-tetrafluorobenzene (5 g, 0.0175 mol) and toluene (50 m
l), aluminum chloride (0.7 g, 0.0053 mol) was slowly added dropwise while stirring at 0 ° C.
Let stir for 12 hours. The obtained reaction solution is poured into ice water,
The organic layer was separated with a separating funnel, dried over magnesium sulfate, concentrated and distilled under reduced pressure to isolate the target silicon compound, dimethyl [di (4-tetrafluorophenyl)] silane. The compound was purified by repeating vacuum distillation several times. The structural analysis of the resulting compound was performed by 1H, 13C-
As a result of NMR spectrum analysis, it was confirmed that the produced compound was dimethyl [di (4-tetrafluorophenyl)] silane. This compound was a colorless and transparent liquid. When this compound was added to an existing liquid crystal composition, it showed extremely excellent compatibility.

(Comparative Example 1) A polyimide was applied as a liquid crystal composition as an alignment film, and the surface was rubbed and vacuum sealed in a liquid crystal cell having a cell interval of 5 μm and provided with a transparent electrode subjected to a 90 ° twist alignment treatment. The rate-voltage curve and response time were measured. The transmittance-voltage curve was obtained by setting the liquid crystal cell between two orthogonal polarizers and applying 1 KHz, 0 to 5 V to the liquid crystal cell.
And a measurement was made in a normally white mode. In this transmittance-voltage curve, the maximum value of the transmittance is 1
The applied voltage at which the transmittance is 90% is V90, and the applied voltage at which the transmittance is 10% is V10.
(FIG. 6). As for the response speed, a voltage of 1 KHz and 5 V was applied at intervals of 1 s, and the time required for the transmittance to change from 100% to 10% was defined as τ (FIG. 7). In addition, a liquid crystal composition is coated with polyimide as an alignment film, the surface is rubbed, and vacuum sealed in a liquid crystal cell having a cell interval of 25 μm with a transparent electrode subjected to 180 ° alignment treatment. The dielectric anisotropy Δε was measured.

In the liquid crystal composition 1 composed of only a compound having a fluorine atom at the terminal, V90 = 1.78V, V1
0 = 2.90 V, τ = 15.2 ms, and Δε = 4.4.

(Comparative Example 2) The transmittance-voltage curve, response time and dielectric anisotropy of a liquid crystal composition 2 composed only of a compound having a fluorine atom at the terminal were measured in the same manner as in Comparative Example 1. Then, V90 = 2.02V, V10 =
2.96 V, τ = 17.6 ms, Δε = 5.1.

Example 10 A composition obtained by adding 16.7% by weight of the compound dimethyl (cyclohexyl) phenylsilane described in Example 1 to the liquid crystal composition 1 in Comparative Example 1 was transmitted in the same manner as in Comparative Example 1. When the rate-voltage curve, the response time, and the dielectric anisotropy were measured, V90 = 1.8.
4V, V10 = 3.12V, τ = 11.2ms, Δε =
3.8.

Example 11 A composition obtained by adding 16.7% by weight of the compound dimethyl (cyclopentyl) phenylsilane described in Example 2 to the liquid crystal composition 1 in Comparative Example 1 was transmitted in the same manner as in Comparative Example 1. When the rate-voltage curve, response time and dielectric anisotropy were measured, V90 = 1.6.
4V, V10 = 2.94V, τ = 11.2ms, Δε =
3.7.

(Example 12) A composition obtained by adding 16.7% by weight of the compound dimethyl (4-chlorophenyl) phenylsilane described in Example 3 to the liquid crystal composition 1 in Comparative Example 1 was produced in the same manner as in Comparative Example 1. , Transmittance-voltage curve, response time and dielectric anisotropy were measured.
70V, V10 = 2.84V, τ = 13.9ms, Δε
= 4.6.

(Example 13) A method similar to that of Comparative Example 1 was obtained by adding 16.7% by weight of the compound dimethyl (4-cyanophenyl) phenylsilane described in Example 4 to the liquid crystal composition 1 of Comparative Example 1. Measured the transmittance-voltage curve, the response time, and the dielectric anisotropy, V90 = 1.
68V, V10 = 2.81V, τ = 14.1ms, Δε
= 4.7.

(Example 14) A method similar to that of Comparative Example 1 was obtained by adding 16.7% by weight of the compound dimethyl (4-butylphenyl) phenylsilane described in Example 5 to the liquid crystal composition 1 of Comparative Example 1. Measured the transmittance-voltage curve, the response time, and the dielectric anisotropy, V90 = 1.
84V, V10 = 3.11V, τ = 11.4ms, Δε
= 3.9.

(Example 15) The same as Comparative Example 1 except that the liquid crystal composition 1 of Comparative Example 1 was added with the compound dibutyl [di (4-butylphenyl)] silane described in Example 6 at 16.7% by weight. When the transmittance-voltage curve, response time, and dielectric anisotropy were measured by a simple method, V90 = 1.8.
9V, V10 = 3.17V, τ = 13.6ms, Δε =
3.5.

(Example 16) A composition obtained by adding 16.7% by weight of the compound dimethyl [di (4-butylphenyl)] silane described in Example 7 to the liquid crystal composition 1 of Comparative Example 1 was the same as Comparative Example 1. The transmittance-voltage curve, response time and dielectric anisotropy were measured by a simple method, and V90 = 1.7.
9V, V10 = 3.09V, τ == 11.5ms, Δε
= 4.0.

(Example 18) A composition obtained by adding 16.7% by weight of the compound dimethyl [di (4-butylphenyl)] silane described in Example 7 to the liquid crystal composition 2 in Comparative Example 2 was the same as Comparative Example 1. The transmittance-voltage curve, the response time and the dielectric anisotropy were measured by a simple method.
4V, V10 = 2.97V, τ == 10.9ms, Δε
= 4.9.

(Example 19) A composition obtained by adding 16.7% by weight of the compound dimethyl [di (4-butylcyclohexyl)] silane described in Example 8 to the liquid crystal composition 1 of Comparative Example 1 was the same as Comparative Example 1. The transmittance-voltage curve, the response time and the dielectric anisotropy were measured by the following methods.
1.62 V, V10 = 2.94 V, τ = 11.3 ms,
Δε = 3.7.

(Example 20) A composition obtained by adding 16.7% by weight of the compound dimethyl [di (4-butylcyclohexyl)] silane described in Example 8 to the liquid crystal composition 2 in Comparative Example 2 was the same as Comparative Example 1. The transmittance-voltage curve, the response time and the dielectric anisotropy were measured by the following methods.
2.00 V, V10 = 2.91 V, τ = 10.6 ms,
Δε = 4.5.

(Example 21) The compound dimethyl [di (4-butyl2,3,5,6-tetrafluorophenyl)] silane described in Example 9 was added to the liquid crystal composition 1 of Comparative Example 1 at 16.7% by weight. When the transmittance-voltage curve, the response time, and the dielectric anisotropy of the added composition were measured in the same manner as in Comparative Example 1, V90 = 1.47 V and V10 = 2.7.
3V, τ == 11.6 ms, Δε = 3.2.

(Example 22) The compound dimethyl [di (4-butyl2,3,5,6-tetrafluorophenyl)] silane described in Example 9 was added to the liquid crystal composition 2 of Comparative Example 2 at 16.7% by weight. The transmittance-voltage curve, response time, and dielectric anisotropy of the added composition were measured in the same manner as in Comparative Example 1. V90 = 1.85V, V10 = 2.8.
2V, τ = 11.1 ms, Δε = 3.8.

[0063]

The organosilicon compound obtained according to the present invention has good compatibility with various liquid crystal compositions and very excellent chemical stability. Speed improvement was observed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a 1H-NMR spectrum of an organosilicon compound according to Example 7 of the present invention.

FIG. 2 is a diagram showing a 13 C-NMR spectrum of an organosilicon compound according to Example 7 of the present invention.

FIG. 3 is a graph showing a method for measuring a transmittance-voltage curve.

FIG. 4 is a diagram showing a method for measuring a response time.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tomohisa Goto 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Daisaku Nakata 5-7-1 Shiba, Minato-ku, Tokyo NEC Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) C09K 19/54

Claims (6)

(57) [Claims] 1. A liquid crystal additive comprising an organosilicon compound represented by the following general formula (1). Embedded image (Where A and B are mutually independent cyclic substituents, and X and Y are an alkyl group, an alkoxy group, a halogenated alkyl group, a halogenated alkoxyl group, a halogen atom,
It represents any one substituent selected from a hydrogen atom, a hydroxyl group, and a cyano group. ) Wherein said cyclic substituents A, -C _n H _2n + 1 is at least the cyclic substituent A among _{B, -OC n H 2n + 1} , -
F, -Cl, -Br, -I, -OH, -CF 3, -CN
2. The liquid crystal additive according to claim 1, wherein the additive has a substituent selected from the following: wherein n is an integer of 0 to 10. 3. The cyclic substituents A and B are each a 1,4-phenyl group,
3. The liquid crystal additive according to claim 1, wherein the additive is a 1,4-cyclohexyl group. 4. The liquid crystal additive according to claim 1, wherein X and Y are methyl groups. 5. The amount of the organosilicon compound according to any one of claims 1 to 4 is 1 to 1 with respect to the base liquid crystal composition.
50% by weight, wherein the parent liquid crystal composition is a nematic liquid crystal composition or a smectic composition. 6. A liquid crystal display device using the liquid crystal composition according to claim 5.