KR100544105B1 - Nematic liquid crystal composition and liquid crystal display device using the same - Google Patents

Abstract

The present invention discloses a liquid crystal composition exhibiting a nematic phase in a wide temperature range including room temperature, and exhibiting optical anisotropy and dielectric anisotropy of various sizes and capable of multiple driving, and a liquid crystal display device using the same. The liquid crystal composition according to the present invention is characterized by mixing an appropriate amount of a phenyl alkyl dioxaborinane derivative, an isothiocyanate derivative, a tolan derivative, a pyrimidine-phenyl derivative and the like.

Description

Nematic liquid crystal composition and liquid crystal display device using the same

The present invention relates to a liquid crystal composition and a liquid crystal display device using the same, and more particularly, a liquid crystal composition that exhibits a nematic phase in a wide temperature range including room temperature, exhibits optical anisotropy and dielectric anisotropy of various sizes, and is multi-driving. It relates to a liquid crystal display element used.

The compound represented by the following Chemical Formula 1 is a low viscosity nonpolar liquid crystal compound, and its properties are described in detail in DE 2,638,634 and DDR 171,971.

Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a cyano group, a halogen group, a hydrogen group, and A and B are simultaneously or independently phenyl, biphenyl, cyclo Hexyl or a biphenyl group containing a methyl group, R3 represents a methyl group, a halogen group, or a hydrogen group, and Z represents a single bond or an ester bond (-COO-), respectively.

A phenyl alkyl dioxaborinane derivative represented by the following Chemical Formula 2 is a dielectric anisotropy This is a high polarity liquid crystal compound. Synthesis and properties of dioxaborinane derivatives represented by Formula 2 are described in detail in US Pat. No. 4,853,150.

Wherein R 1 represents an alkyl group having 1 to 12 carbon atoms, Y represents a cyano group, a halogen group, OR,

, or Each represents

X, V and W simultaneously or independently represent a hydrogen group, a halogen group, a cyano group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, and R represents an alkyl group having 1 to 12 carbon atoms.

The isothiocyanate derivative represented by Formula 3 is a liquid crystal compound having a low viscosity and high dielectric anisotropy. The properties of isothiocyanate compounds represented by Formula 3 are described in detail in PL 241,286 and US Pat. No. 4,528,116.

R1 represents an alkyl group having 1 to 12 carbon atoms, C and D simultaneously or independently represent a phenyl, biphenyl, cyclohexyl, or cyclohexylphenyl, and W represents a single bond or an ethylene group (-CH ₂ CH _2- ), respectively. .

Tolan derivative represented by the following formula (4) is optical anisotropy As this highly nonpolar liquid crystal compound, its properties are described in detail in US Pat. No. 3,529,482.

In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

The pyrimidine-phenyl derivative represented by the following formula (5) is a liquid crystal having a low modulus of elasticity. Crys. Liq. Cryst, 68, 57 (1981) and DDR 95892.

In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

The compound represented by the following formula (6) is a nonpolar material whose properties are described in detail in Liquid Crystal, 5, 159 (1989).

Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, Z is a hydrogen group, a cyano group, or a halogen group, E is phenyl, biphenyl, cyclohexyl, or Cyclohexylphenyl is shown, respectively.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a liquid crystal composition that exhibits a nematic phase in a wide temperature range including room temperature, exhibits optical anisotropy and dielectric anisotropy of various sizes, and is capable of multi-driving.

Another object of the present invention is to provide a twisted nematic liquid crystal display device using the liquid crystal composition.

In order to achieve the above technical problem, the present invention provides a nematic liquid crystal composition comprising a compound represented by the following Chemical Formula 1 and a compound represented by the following Chemical Formula 2.

<Formula 1>

Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a cyano group, a halogen group, a hydrogen group, and A and B are simultaneously or independently phenyl, biphenyl, cyclo Hexyl or a biphenyl group containing a methyl group, R 3 represents a methyl group, a halogen group, or a hydrogen group, Z represents a single bond or an ester bond (-COO-), respectively.

<Formula 2>

Wherein R 1 represents an alkyl group having 1 to 12 carbon atoms, Y represents a cyano group, a halogen group, OR,

, or Each represents

X, V, W represent a hydrogen group, a halogen group, a cyano group, a C1-C12 alkyl group, or a C1-C12 alkoxy group simultaneously or independently, and R represents a C1-C12 alkyl group.

In the present invention, the compound represented by Formula 1 is 5.0 to 60.0 parts by weight, and the content of the compound represented by Formula 2 is preferably 5.0 to 20.0 parts by weight.

In the present invention, the liquid crystal composition may further include a compound represented by the following formula (3).

<Formula 3>

Wherein R1 is an alkyl group having 1 to 12 carbon atoms, C and D are phenyl, biphenyl, cyclohexyl, or cyclohexylphenyl simultaneously or independently, and W is a single bond or an ethylene group (-CH ₂ CH _2- ) Respectively.

In the present invention, the content of the compound represented by Formula 3 is preferably 5.0 to 20.0 parts by weight.

In the present invention, the liquid crystal composition may further include a compound represented by the following formula (4).

<Formula 4>

In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

In the present invention, the content of the compound represented by Formula 4 is preferably 5.0 to 20.0 parts by weight.

In the present invention, the liquid crystal composition may further include a compound represented by the following formula (5).

<Formula 5>

In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.

In the present invention, the content of the compound represented by Formula 5 is preferably 5.0 to 60.0 parts by weight.

In the present invention, the liquid crystal composition may further include a compound represented by the following formula (6).

<Formula 6>

Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, Z is a hydrogen group, a cyano group or a halogen group, n is 4, and E is each simultaneously or independently Phenyl, biphenyl, cyclohexyl or cyclohexylphenyl are respectively shown.

In the present invention, the content of the compound represented by the formula (6) is preferably 2.0 to 20.0 parts by weight.

In order to achieve the above another technical problem, the present invention also provides a liquid crystal display device, characterized in that the liquid crystal composition according to the present invention is inserted between the pair of electrode substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

Example 1

As shown in Table 1 14.4% by weight of the compound represented by Formula 1a, 2.5% by weight of the compound represented by Formula 1b, 16.2% by weight of the compound represented by Formula 1c, 2.7% by weight of the compound represented by Formula 1d, represented by Formula 1e 4.4 wt% of the compound, 8.9 wt% of the compound represented by Formula 5a, 9.9 wt% of the compound represented by Formula 5b, 12.0 wt% of the compound represented by Formula 5c, 9.1 wt% of the compound represented by Formula 5d, represented by Formula 5f To prepare a liquid crystal composition consisting of 6.2% by weight of the compound, 4.7% by weight of the compound represented by the formula (6a), and 1.5% by weight of the compound represented by the formula (6b). After the liquid crystal composition was heated and stirred above a temperature at which the liquid crystal composition exhibits an isotropic phase, the liquid crystal composition was again cooled to room temperature to obtain a uniformly mixed liquid crystal composition.

The liquid crystal composition thus obtained was injected into a 90 µm twisted nematic (TN) cell, and the electrooptical properties were measured at room temperature. The electro-optical properties thus obtained are shown in Table 2. Referring to Table 2, T _{NI, which} is a temperature at which the liquid crystal composition is transferred from the nematic phase to the isotropic phase, was 66.5 ° C. Therefore, it turned out that this liquid crystal composition shows a nematic phase to 66.5 degreeC including room temperature. On the other hand, the optical anisotropy Δn is 0.133, the dielectric anisotropy Δε is 15.0, the threshold voltage V _{10, which} is a voltage when 10% of the light is administered to the cell, is 1.36V, and 90% of the light is administered to the cell. The saturation voltage V _{90, which} is the voltage at the time of passage, was 1.95 V, and the number of duties N _90, defined as below, was 8.37.

Examples 2 to 13

A liquid crystal composition was prepared in the same manner as in Example 1, except that each component of the liquid crystal composition was changed as shown in Table 1. The liquid crystal composition thus obtained was injected into a 90 µm twisted nematic (TN) cell as in Example 1, and the electrooptical properties were measured at room temperature. The electro-optical properties thus obtained are shown in Table 2.

Referring to Table 2, it can be seen that the T _NI of the liquid crystal composition according to the present invention maintains a nematic phase in a wide temperature range including 63.2 to 80.0 ° C. In addition, as can be seen in Tables 1 and 2, the liquid crystal composition of the present invention can adjust optical anisotropy and dielectric anisotropy in various ways by adjusting the ratio of each component, and the N ₉₀ value range is 8.37 to 10.85, which enables multi-driving. Able to know. On the other hand, the alkyl group portion of the alkyl group or the alkoxy group in the above Table 1 all represent a normal (normal) group.

TABLE 1-1

TABLE 1-2

TABLE 2

T _NI (℃) V ₁₀ (V) V ₉₀ (V) N ₉₀ Example 1    66.5   0.133    15.0    1.36    1.95    8.37 Example 2    70.7   0.132    18.4    1.23    1.76    8.46 Example 3    64.3   0.121    13.4    1.46    2.00   10.76 Example 4    63.6   0.135    11.4    1.52    2.09   10.53 Example 5    80.0   0.131    12.7    1.67    2.31   10.17 Example 6    77.8   0.134    10.9    1.76    2.42   10.53 Example 7    73.0   0.133    11.6    1.63    2.23   10.85 Example 8    80.0   0.134    16.8    1.49    2.13    8.50 Example 9    69.8   0.128    11.2    1.59    2.18   10.71 Example 10    67.0   0.132     9.8    1.65    2.27   10.50 Example 11    66.3   0.130    11.6    1.55    2.14   10.28 Example 12    72.0   0.131    11.1    1.67    2.30   10.43 Example 13    65.5   0.131    10.6    1.60    2.21   10.25

As described above, the liquid crystal composition according to the present invention exhibits a nematic phase in a wide temperature range including room temperature, and has optical anisotropy and dielectric anisotropy of various sizes. In addition, the TN liquid crystal display device manufactured using the liquid crystal composition of the present invention is capable of multiple driving.

Claims (18)

A nematic liquid crystal composition comprising a compound represented by Formula 1, a compound represented by Formula 2, and a compound represented by Formula 6 below: <Formula 1> Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a cyano group, a halogen group, a hydrogen group, and A and B are simultaneously or independently phenyl, biphenyl, cyclo Hexyl or a biphenyl group containing a methyl group, R 3 represents a methyl group, a halogen group, or a hydrogen group, Z represents a single bond or an ester bond (-COO-), respectively. <Formula 2> Wherein R 1 represents an alkyl group having 1 to 12 carbon atoms, Y represents a cyano group, a halogen group, OR, , or Each represents X, V and W simultaneously or independently represent a hydrogen group, a halogen group, a cyano group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, R represents an alkyl group having 1 to 12 carbon atoms, <Formula 6> Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, Z is independently a hydrogen group, a cyano group or a halogen group, n is 4, and E is each simultaneously or Each independently represents phenyl, biphenyl, cyclohexyl or cyclohexylphenyl. According to claim 1, wherein the compound represented by the formula (1) is 5.0 to 60.0 parts by weight, the content of the compound represented by the formula (2) is 5.0 to 20.0 parts by weight, the content of the compound represented by the formula (6) Nematic liquid crystal composition, characterized in that 2.0 to 20.0 parts by weight. The method of claim 1, wherein the liquid crystal composition, Nematic liquid crystal composition further comprises a compound represented by the formula (3): <Formula 3> Wherein R1 is an alkyl group having 1 to 12 carbon atoms, C and D are phenyl, biphenyl, cyclohexyl, or cyclohexylphenyl simultaneously or independently, and W is a single bond or an ethylene group (-CH ₂ CH _2- ) Respectively. The nematic liquid crystal composition according to claim 3, wherein the compound represented by Chemical Formula 3 is 5.0 to 20.0 parts by weight. According to claim 1 or 3, wherein the liquid crystal composition, Nematic liquid crystal composition further comprises a compound represented by the following formula (4): <Formula 4> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The nematic liquid crystal composition according to claim 5, wherein the compound represented by Chemical Formula 4 is 5.0 to 20.0 parts by weight. According to claim 1 or 3, wherein the liquid crystal composition, Nematic liquid crystal composition further comprises a compound represented by the formula (5): <Formula 5> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The nematic liquid crystal composition according to claim 7, wherein the compound represented by Chemical Formula 5 is 5.0 to 60.0 parts by weight. A nematic liquid crystal composition comprising a compound represented by Formula 1, a compound represented by Formula 2, and a compound represented by Formula 6 is inserted between a pair of electrode substrates. : <Formula 1> Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a cyano group, a halogen group, a hydrogen group, and A and B are simultaneously or independently phenyl, biphenyl, cyclo Hexyl or a biphenyl group containing a methyl group, R 3 represents a methyl group, a halogen group, or a hydrogen group, Z represents a single bond or an ester bond (-COO-), respectively. <Formula 2> Wherein R 1 represents an alkyl group having 1 to 12 carbon atoms, Y represents a cyano group, a halogen group, OR, , or Each represents X, V and W simultaneously or independently represent a hydrogen group, a halogen group, a cyano group, an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, R represents an alkyl group having 1 to 12 carbon atoms, <Formula 6> Wherein R1 and R2 are simultaneously or independently an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms, Z is independently a hydrogen group, a cyano group or a halogen group, n is 4, and E is each simultaneously or Each independently represents phenyl, biphenyl, cyclohexyl or cyclohexylphenyl. The method of claim 9, wherein the compound represented by the formula (1) in the liquid crystal composition is 5.0 to 60.0 parts by weight, the content of the compound represented by the formula (2) is 5.0 to 20.0 parts by weight, and also to the formula (6) The content of the compound to be displayed is a liquid crystal display device, characterized in that 2.0 to 20.0 parts by weight. The liquid crystal display device of claim 9, wherein the liquid crystal composition of the liquid crystal display device further comprises a compound represented by Formula 3 below: <Formula 3> Wherein R1 is an alkyl group having 1 to 12 carbon atoms, C and D are phenyl, biphenyl, cyclohexyl, or cyclohexylphenyl simultaneously or independently, and W is a single bond or an ethylene group (-CH ₂ CH _2- ) Respectively. The liquid crystal display device according to claim 11, wherein the content of the compound represented by Chemical Formula 3 in the liquid crystal composition is 5.0 to 20.0 parts by weight. The liquid crystal display device of claim 9 or 11, further comprising a compound represented by the following Chemical Formula 4 in the liquid crystal composition of the liquid crystal display device: <Formula 4> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The liquid crystal display device according to claim 13, wherein the content of the compound represented by Chemical Formula 4 in the liquid crystal composition is 5.0 to 20.0 parts by weight. The liquid crystal display device of claim 9 or 11, further comprising a compound represented by the following Chemical Formula 5 in the liquid crystal composition of the liquid crystal display device: <Formula 5> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The liquid crystal display device according to claim 17, wherein the content of the compound represented by Chemical Formula 5 in the liquid crystal composition is 5.0 to 60.0 parts by weight. The method of claim 5, wherein the liquid crystal composition, Nematic liquid crystal composition further comprises a compound represented by the formula (5): <Formula 5> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. The liquid crystal display device of claim 13, wherein the liquid crystal composition of the liquid crystal display device further comprises a compound represented by Formula 5 below: <Formula 5> In the above formula, R1 and R2 simultaneously or independently represent an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms.