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    • 专利摘要:
    The present invention provides a cyclohexanone derivative, a nematic liquid crystal composition including the same, and a liquid crystal display device using the same. The cyclohexanone derivative has excellent chemical and thermal stability, high voltage holding ratio and high resistivity, and low threshold voltage and low threshold voltage constant. And the liquid crystal composition containing such liquid crystal compounds has a nematic phase in a wide temperature range. Using such a composition, a liquid crystal display device having positive dielectric anisotropy and good optical anisotropy and driving voltage characteristics can be produced.
    公开号:KR20000054974A
    申请号:KR1019990003371
    申请日:1999-02-02
    公开日:2000-09-05
    发明作者:김성한；어기한；이유진
    申请人:김순택；삼성에스디아이 주식회사；
    IPC主号:
    专利说明:

    Cyclohexanone derivative, nematic liquid crystal composition comprising the same, and liquid crystal display using the nematic liquid crystal composition
    The present invention relates to a cyclohexanone derivative, a nematic liquid crystal composition comprising the same, and a liquid crystal display device using the nematic liquid crystal composition, and more particularly, cyclohexanone, thereby including optical anisotropy (Δn) and driving voltage characteristics. The improvement relates to a nematic liquid crystal composition exhibiting a nematic liquid crystal phase in a wide temperature range and a liquid crystal display device using the nematic liquid crystal composition.
    The liquid crystal display device is small in size, light in weight and low in power consumption, and has the advantage that no harmful electromagnetic waves are emitted. Therefore, the liquid crystal display device is widely used from the small display part of the electronic calculator to the notebook computer.
    The performance of the liquid crystal display device generally depends very much on the physical and electro-optical properties of the liquid crystal mixture. Therefore, the composition of the liquid crystal mixture should be optimized using liquid crystal compounds having certain physical properties so as to obtain the desired electro-optic behavior.
    Liquid crystal compounds generally require chemical and thermal stability and stability to electric fields. In addition, the liquid crystal compound should have low viscosity, short addressing time, low threshold voltage and high contrast. It should also have a suitable mesophase, eg nematic mesophase or cholesteric mesophase at operating temperature. As a practical liquid crystal material, it is common to use a mixture containing a plurality of liquid crystal components. Therefore, the liquid crystal components should be easily mixed with each other, and characteristics such as electrical conductivity, dielectric anisotropy, and optical anisotropy may also be used for cell types and applications. It must meet certain conditions. For example, the liquid crystal for twisted nematic cells should have a positive value of dielectric anisotropy (Δε) and a small value of electrical conductivity.
    On the other hand, nematic liquid crystal display devices are widely used because they have a wide range of uses and various display parameters and addressing schemes. Due to this, there is a growing demand for nematic liquid crystal compositions having a wide range of physical properties, and specific examples of liquid crystal compounds constituting such nematic liquid crystal compositions are disclosed in US Pat. Nos. 5,560,863, WO 96/06073 and WO 96/06061. It is disclosed in the call. Among them, US Pat. No. 5,560,863 discloses 2-fluorocyclohexene derivatives.
    By the way, in the nematic liquid crystal display device, the allowable range of the display variable is usually narrow. Therefore, in order to optimize these variables, it is urgent to develop a nematic liquid crystal composition which can be mixed in any ratio without impairing the mesophase characteristics. To this end, research on a liquid crystal compound having a nematic liquid crystal phase in the widest temperature range possible, in particular, a temperature range of -30 ° C to + 65 ° C, as well as a small driving voltage, and having various optical anisotropy characteristics should be preceded.
    Therefore, the technical problem to be achieved by the present invention is not only to have a nematic liquid crystal phase in a wide temperature range and to have positive dielectric anisotropy (Δε), but also good optical anisotropy (Δn) and driving voltage characteristics. It is to provide a liquid crystal composition and a novel cyclohexanone derivative constituting the same.
    Another object of the present invention is to provide a liquid crystal display device having improved performance by providing a liquid crystal layer made of the nematic liquid crystal composition.
    In order to achieve the above technical problem, the present invention provides a cyclohexanone derivative represented by Chemical Formula 1.
    <Formula 1>
    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other.
    R 1 is selected from the group consisting of CN, F, Cl, OCF 3 , OCHF 2 , CF 3 , OCHFCF 3 and OCH 2 CF 3 , R 2 is ethyl (C 2 H 5 ), propyl (C 3 H 7 ), Butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ).
    Another technical problem of the present invention is achieved by a nematic liquid crystal composition comprising a cyclohexanone derivative of the formula (1).
    <Formula 1>
    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other.
    Preferably, the nematic liquid crystal composition further includes at least one selected from the compounds represented by Formula 2 and Formula 3.

    In the above formula,
    ego,
    R 4 and R 6 are alkyl groups having 1 to 12 carbon atoms, and R 5 is selected from the group consisting of a cyano group and a halogen atom.
    Preferably, R 4 and R 6 are independently of each other ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ), and R 5 is cyano group, F, CF 3 , OCF 3 .
    Another technical problem of the present invention is a liquid crystal display device having a liquid crystal layer interposed between a pair of electrode substrates,
    The liquid crystal layer is made of a liquid crystal display device comprising a nematic liquid crystal composition containing a liquid crystal compound of formula (1).
    <Formula 1>
    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other.
    The cyclohexanone derivative of the general formula (1) according to the present invention contains a cyclohexanone ring and an ethylene group, as can be seen from the structural formula. The field of application of this compound is not particularly limited. In particular, this material is a nematic liquid crystal having a nematic phase over a wide temperature range, and can form a super-twist nematic liquid crystal composition having low viscosity and fast response speed. Specific examples of such a compound include R 1 is F, R 2 is C 3 H 7 , R 3 and R 3 ′ are H and R 1 is F, and R 2 is C 5 There is a compound (B) wherein H 11 and R 3 and R 3 ′ are both H.
    These liquid crystal compounds have excellent chemical and thermal stability, high voltage retention and specific resistance, and low threshold voltage and threshold voltage constants. In addition, in the liquid crystal composition including the liquid crystal compounds, the change in the threshold voltage according to the temperature is minimized to maintain the driving voltage at a predetermined value at the operating temperature of the liquid crystal display device.
    On the other hand, the nematic liquid crystal composition of the present invention includes a cyclohexanone derivative of the formula (1) described above as a liquid crystal compound. In addition, the nematic liquid crystal composition may properly adjust physical properties and various optical parameters of the liquid crystal composition by mixing appropriate basic liquid crystal compounds in addition to the liquid crystal compound of Chemical Formula 1. Herein, the content of the liquid crystal compound of Chemical Formula 1 in the nematic liquid crystal composition may be variously changed according to the purpose of use.
    The basic liquid crystal compounds may be used as long as they are normally used in the nematic liquid crystal composition, and the content thereof is also at a conventional level used in the nematic liquid crystal composition. Preferably, at least one selected from the compounds represented by Formulas 2 and 3 is used as the basic liquid crystal compounds.
    <Formula 2>
    <Formula 3>
    In the above formula,
    ego,
    R 4 and R 6 are alkyl groups having 1 to 12 carbon atoms, and R 5 is selected from the group consisting of a cyano group and a halogen atom.
    In Formulas 2 and 3, specific examples of R 4 and R 6 may be ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl ( C 6 H 13 ), and specific examples of R 5 include CN, F, CF 3 , OCF 3 .
    The nematic liquid crystal composition as described above exhibits a nematic liquid crystal phase in a wide temperature range, and is excellent in optical anisotropy (Δn), driving voltage and viscosity characteristics. Therefore, when the liquid crystal layer is formed using the nematic liquid crystal composition, a liquid crystal display device having improved performance can be obtained.
    Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited only to the following Examples.
    <Synthesis example>
    From here. R is R = C 3 H 7 or C 5 H 11
    1. Preparation of Mannich salt
    300-400 ml of ethanol was added to a mixture of 1.0 mol of 4-fluoroacetophenone, 1.3 mol of paraformaldehyde, 1.3 mol of dimethylamine hydrochloride, and 1 ml of concentrated hydrochloric acid, and the mixture was refluxed for 3 to 5 hours.
    The reaction mixture was distilled off to remove most of the solvent. The resulting transparent solution was diluted with 1.0 L of acetone, which was then left in the refrigerator overnight.
    The resulting product was filtered and then washed with cold acetone and dried to give the Mannich salt (yield: 68%).
    2.3- (4-fluorophenyl) -6- [2- (trans-4-alkylcyclohexyl) ethyl] cyclohex-2-en-1-one {3- (4-fluorophenyl) -6- [2- Preparation of (trans-4-alkylcyclohexyl) ethyl] cyclohex-2-en-one}
    To 0.1 mole of the Mannich salt, 0.1 mole of 2- [2- (trans-4-alkylcyclohexyl) ethyl] acetoacetic ester and 0.3 mole of a 150 ml solution of potassium dioxane were added and mixed.
    The mixture was refluxed for 5 hours, then cooled and 10% sulfuric acid solution was added thereto. When sulfuric acid solution is added, carbon dioxide is released. Therefore, sulfuric acid solution should be added carefully.
    The reaction product was extracted using benzene, and then the organic layer was collected. The solvent was removed from the collected organic layer, and then recrystallized with ethanol to obtain a ketone compound.
    R = C 3 H 7 : Yield 65%,
    R = C 5 H 11 : Yield 63%
    3. trans-5- (4-fluorophenyl) -2- [2-trans-4-alkylcyclohexyl) ethyl] cyclohexanone {trans-5- (4-fluorophenyl) -2- [2- (trans Preparation of -4-alkylcyclohexyl) ethyl] cyclohexanone}
    To 50 ml of ethanol-THF (1: 1 v: v) containing 0.5 g of potassium hydroxide, 3- (4-fluorophenyl) -6- [2- (trans-4-alkylcyclohexyl) ethyl] cyclohex 12 g of 2-en-1-one was added to dissolve, and then it was atmospheric pressure in the presence of 10 wt% Pd / C. The hydrogenation reaction was performed at 30-40 degreeC. The hydrogenation reaction continued at this point until no more hydrogen was absorbed by the reaction mixture.
    When the reaction was completed, the catalyst was removed by filtration, and then the solvent was removed by evaporation under reduced pressure. The resulting product was dissolved in benzene and then washed with water and dried over anhydrous magnesium sulfate. The solvent was evaporated and then recrystallized with ethanol to give trans-5- (4-fluorophenyl) -2- [2- (trans-4-alkylcyclohexyl) ethyl] cyclohexanone.
    R = C 3 H 7 , yield 82%; Cr 73 N 119 l;
    R = C 5 H 11 , yield 63%; Cr 83 N 124 l;
    Comparative example
    A nematic liquid crystal composition was prepared by mixing 22 wt% of the liquid crystal compound (C), 20 wt% of the liquid crystal compound (D), 30 wt% of the liquid crystal compound (E), and 28 wt% of the liquid crystal compound (F). At this time, the nematic liquid crystal composition was heated and stirred above a temperature exhibiting an isotropic phase, and then cooled to room temperature to obtain a liquid crystal composition in which the composition was uniformly mixed.
    A liquid crystal display device was completed by injecting a liquid crystal composition obtained according to the above process into a 90 ° twist cell (cell thickness: 7 μm) to form a liquid crystal layer.
    Example 1
    19.8 wt% of the liquid crystal compound (C), 18.0 wt% of the liquid crystal compound (D), 27.0 wt% of the liquid crystal compound (E), 25.2 wt% of the liquid crystal compound (F), and 10 wt% of the liquid crystal compound (A) were mixed to prepare a liquid crystal composition. A liquid crystal display device was completed in the same manner as in Comparative Example, except that manufactured.
    Example 2
    A liquid crystal display device was completed in the same manner as in Example 1 except that the liquid crystal compound (B) was used instead of the liquid crystal compound (A).
    The state of phase change of the liquid crystal compounds (A)-(B) used in Example 1-2 was investigated using a polarization microscope equipped with a hot stage, and the results are shown in Table 1 below. It was.
    divisionPhase transition temperature (℃) Liquid Crystal Compound (A)C 73 N 119 I Liquid Crystal Compound (B)C 83 N 124 I
    In Table 1, C is a solid phase, N is a nematic phase, I means an isotropic phase, respectively.
    From Table 1, it can be seen that the liquid crystal compound (A) is a nematic liquid crystal transitioned from the solid phase to the nematic phase at 73 ° C, and the liquid crystal compound (B) is transitioned from the solid phase to the nematic phase at 83 ° C.
    On the other hand, in the liquid crystal display device manufactured according to Example 1-2 and Comparative Example, the electro-optical properties of the liquid crystal compositions were investigated, and the results are shown in Table 2 below.
    divisionT NI a (℃)△ nΔεV 10 bComparative example58.20.1126.071.57 Example 164.00.1055.271.70 Example 264.80.1065.601.60
    a: temperature at which the liquid crystal composition is transferred from the nematic phase to the isotropic phase
    b: Threshold voltage when 10% of the light irradiated to the cell passes
    From Table 2, it can be seen that the liquid crystal composition according to Example 1-2 has a wider temperature range in which the T NI exhibits a nematic phase and a dielectric anisotropy than the comparative example. And it can be seen that the liquid crystal compositions of Examples 1 to 2 are excellent in threshold voltage (V 10 ) characteristics and Δn characteristics.
    Cyclohexanone derivatives of the general formula (1) according to the present invention is a material excellent in chemical and thermal stability, the scope of application is wide. In particular, this material has nematic liquid crystal properties, which have high voltage retention and specific resistance, and low threshold and constant threshold voltages. And the liquid crystal composition containing such liquid crystal compounds has a nematic phase in a wide temperature range. By using such a liquid crystal composition, a liquid crystal display device having positive dielectric anisotropy and good optical anisotropy and driving voltage characteristics can be manufactured.
    权利要求:
    Claims (19)
    [1" claim-type="Currently amended] Cyclohexanone derivatives represented by Formula 1:
    <Formula 1>

    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other,
    n is an integer of 1-2.
    [2" claim-type="Currently amended] The cyclohexanone derivative of claim 1, wherein R 1 is selected from the group consisting of CN, F, Cl, OCF 3 , OCHF 2 , CF 3 , OCHFCF 3 and OCH 2 CF 3 .
    [3" claim-type="Currently amended] The method of claim 1, wherein R 2 is ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ) Cyclohexanone derivative of the formula (1), characterized in that.
    [4" claim-type="Currently amended] The cyclohexanone derivative of claim 1, wherein R 1 is F, R 2 is C 3 H 7 , R 3 and R 3 ′ are both H and n is 1. 7.
    [5" claim-type="Currently amended] The cyclohexanone derivative of claim 1, wherein R 1 is F, R 2 is C 5 H 11 , R 3 and R 3 ′ are both H and n is 1. 4.
    [6" claim-type="Currently amended] A nematic liquid crystal composition comprising a cyclohexanone derivative of the formula (1).
    <Formula 1>

    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other,
    n is an integer of 1-2.
    [7" claim-type="Currently amended] The nematic liquid crystal composition according to claim 6, wherein the nematic liquid crystal composition further comprises at least one selected from compounds represented by Formulas 2 and 3.
    <Formula 2>

    <Formula 3>

    In the above formula,

    ego,
    R 4 and R 6 are alkyl groups having 1 to 12 carbon atoms, and R 5 is selected from the group consisting of a cyano group and a halogen atom.
    [8" claim-type="Currently amended] 8. The compound of claim 7, wherein R 4 and R 6 are independently of each other ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ), R 5 is a cyano group, F, CF 3 , OCF 3 , characterized in that the nematic liquid crystal composition.
    [9" claim-type="Currently amended] The nematic liquid crystal composition of claim 6, wherein R 1 is selected from the group consisting of CN, F, Cl, OCF 3 , OCHF 2 , CF 3 , OCHFCF 3, and OCH 2 CF 3 .
    [10" claim-type="Currently amended] The method of claim 6, wherein R 2 is ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ) Nematic liquid crystal composition, characterized in that
    [11" claim-type="Currently amended] The nematic liquid crystal composition of claim 6, wherein R 1 is F, R 2 is C 3 H 7 , R 3 and R 3 ′ are both H and n is 1. 8.
    [12" claim-type="Currently amended] The nematic liquid crystal composition of claim 6, wherein R 1 is F, R 2 is C 5 H 11 , R 3 and R 3 ′ are both H and n is 1. 7.
    [13" claim-type="Currently amended] A liquid crystal display device comprising a liquid crystal layer interposed between a pair of electrode substrates,
    The liquid crystal display device, characterized in that the liquid crystal layer is made of a nematic liquid crystal composition containing a liquid crystal compound of formula (1).
    <Formula 1>

    Wherein R 1 represents a C 1 -C 12 alkyl group, a C 1 -C 12 alkoxy group, F, CN, Cl, a halogenated C 1 -C 5 alkyl group, a halogenated C 1 -C 5 alkoxy group,
    R 2 represents a C 1 -C 12 alkyl group or a C 1 -C 12 alkoxy group,
    R 3 and R 3 ′ are H or F irrespective of each other,
    n is an integer of 1-2.
    [14" claim-type="Currently amended] The liquid crystal display device according to claim 13, wherein the nematic liquid crystal composition further comprises at least one selected from compounds represented by Formulas 2 and 3.
    <Formula 2>

    <Formula 3>

    In the above formula,

    ego,
    R 4 and R 6 are alkyl groups having 1 to 12 carbon atoms, and R 5 is selected from the group consisting of a cyano group and a halogen atom.
    [15" claim-type="Currently amended] The method of claim 13, wherein R 4 and R 6 are independently of each other ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ), and R 5 is a cyano group, F, CF 3 , OCF 3 .
    [16" claim-type="Currently amended] The liquid crystal display device of claim 13, wherein R 1 is selected from the group consisting of CN, F, Cl, OCF 3 , OCHF 2 , CF 3 , OCHFCF 3, and OCH 2 CF 3 .
    [17" claim-type="Currently amended] The method of claim 13, wherein R 2 is ethyl (C 2 H 5 ), propyl (C 3 H 7 ), butyl (C 4 H 9 ), pentyl (C 5 H 11 ) or hexyl (C 6 H 13 ) Liquid crystal display device characterized in that.
    [18" claim-type="Currently amended] The liquid crystal display device of claim 13, wherein R 1 is F, R 2 is C 3 H 7 , both R 3 and R 3 ′ are H, and n is 1. 15.
    [19" claim-type="Currently amended] The liquid crystal display device of claim 13, wherein R 1 is F, R 2 is C 5 H 11 , R 3 and R 3 ′ are both H and n is 1. 15.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-02-02|Application filed by 김순택, 삼성에스디아이 주식회사
    1999-02-02|Priority to KR1019990003371A
    1999-10-18|Priority claimed from JP11295941A
    2000-09-05|Publication of KR20000054974A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019990003371A|KR20000054974A|1999-02-02|1999-02-02|Cyclohexanone derivative, nematic liquid crystal composition comprising the same, and liquid crystal display using the nematic liquid crystal composition|
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