Compound, liquid crystal composition containing the compound, and liquid crystal display element using the liquid crystal composition

Abstract

The present invention provides a compound with a low rotational viscosity having a more negative dielectric constant anisotropy than conventional liquid crystal compounds, and a liquid crystal composition and a liquid crystal display element using the compound. The compound is a compound having a dielectric constant anisotropy more negative than -4, comprising two sites separated by a methylene spacer having a carbon number of 2 or more in one molecule, each of the sites having at least two or more fluorine groups, and the vector sum of the dipole moment of each of the sites is oriented perpendicular to the molecular axis, and the compound is represented by the following general formula (1), wherein the two sites are connected from an atom bound to one end of the methylene spacer contained in the linking group X to an atom bound to R 1 A series of sites as the terminal, and from the atom bonded to the other end of the methylene spacer contained in the linking group X to the atom with R 2 The terminal part is composed of a series of sites. The linker X containing a methylene spacer represents ‑(CH2)n‑, and n represents 2 to 10. #imgabs0#

Description

Technical Field

[0001] The present invention relates to a compound having negative dielectric anisotropy, a liquid crystal composition containing the compound, and a liquid crystal display element using the liquid crystal composition. Background Art

[0002] Liquid crystal display elements are used for automobile panels, word processors, electronic notepads, printers, computers, mobile phones, televisions, advertising display boards, etc. As liquid crystal display modes, representative modes include TN (twisted nematic) type, STN (super twisted nematic) type, MVA (multi-domain vertical alignment) type using TFT (thin film transistor), PSA (polymer stable alignment, polymer sustained alignment) type, IPS (in-plane switching) type, FFS (fringe field switching) type, etc. The liquid crystal composition used for these liquid crystal display elements is required to be stable to external factors such as moisture, air, heat, and light, and to display liquid crystal phases in a temperature range as wide as possible centered on room temperature, and low viscosity. Furthermore, from the viewpoints of the values ​​of dielectric constant anisotropy (Δε) or refractive index anisotropy (Δn) required by each display element, as shown in the following patent document 1, the liquid crystal composition is composed of a variety of to about twenty compounds.

[0003] Especially in recent years, liquid crystal compositions with high-speed responsiveness are required. In order to achieve the target physical properties, various methods can be considered, but as an effective means, the low viscosity of the liquid crystal composition can be listed. In order to reduce the viscosity of the liquid crystal composition, it is extremely effective to add a compound with low viscosity (η). In particular, it is effective to add a compound with low rotational viscosity (γ1). However, the previous compounds with very low viscosity are almost all non-polar compounds with dielectric constant anisotropy near 0, and when the compound is used in large quantities, the dielectric constant anisotropy is reduced. Therefore, in order to achieve the desired dielectric constant anisotropy, so many low viscosity compounds cannot be used. This becomes a problem when making a low-viscosity, negative dielectric constant anisotropy liquid crystal composition.

[0004] Therefore, in order to further improve the liquid crystal properties, it is necessary to develop a compound having a stronger negative dielectric anisotropy than the existing compounds. By using a small amount of a compound having a strong negative dielectric anisotropy and a large amount of a low-viscosity non-polar compound, a low-viscosity liquid crystal composition having a desired negative dielectric anisotropy can be prepared. For example, the following patent document 2 discloses a compound comprising two parts separated by a linking group comprising an alkynyl group and having a negative dielectric anisotropy. However, the technology disclosed in the above patent document does not achieve the required characteristics.

[0005] Prior art

[0006] Patent Literature

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2006-99038

[0008] [Patent Document 2] Japanese Patent Publication No. 2006-520098 Summary of the invention

[0009] Problems to be solved by the invention

[0010] The present invention has been made in view of the above-mentioned current situation, and an object of the present invention is to provide a compound having a lower rotational viscosity and a more negative dielectric anisotropy than conventional compounds, a liquid crystal composition using the compound, and a liquid crystal display element using the liquid crystal composition.

[0011] Means of solving problems

[0012] In order to solve the above-mentioned problems, the present invention provides a compound comprising two sites separated by a predetermined spacer having at least carbon atoms, the molecular axes starting from the bonding portion between the spacer and each site and along the direction toward the end of each site are respectively defined, and have a predetermined negative dielectric constant anisotropy, the spacer is a methylene spacer having 2 or more carbon atoms in one molecule, each site is constructed to have at least 2 or more fluorine groups, and the vector sum of the dipole moment of each site is oriented in a perpendicular direction relative to each molecular axis, and the negative dielectric constant anisotropy is more negative than -4.

[0013] The present invention is characterized in that the compound is represented by the following general formula (1), wherein the two sites are from the atom bonded to one end of the methylene spacer contained in the linker X to the atom connected to the R 1 A series of sites as the terminal, and from the atom bonded to the other end of the methylene spacer contained in the linking group X to the atom ending with R 2As a series of terminal site compositions, the linking group X containing the methylene spacer in the following general formula (1) represents -(CH2)n-, and n represents 2 to 10.

[0014]

[0015] In the formula, R 1 and R 2 represents an alkyl group having 1 to 9 carbon atoms, an alkoxy group, an alkenyl group having 2 to 9 carbon atoms, or an alkenyloxy group, a and d represent 0, 1 or 2, b and c represent 0 or 1, and ring A and ring B represent any one of the following structural formulas (a-1) to (a-4),

[0016]

[0017] Z 1 and Z 2 Each independently represents -CH2O-, -OCH2-, -COO-, -OCO-, -CH2CH2-, -CF2CF2-, -CH=CH-, -CF=CF-, -C≡C- or a single bond,

[0018] In addition, the compound of the present invention is preferably: as the connecting group X containing the methylene spacer in the general formula (1), -(CH2)n- is replaced by -O-(CH2)nO-, and n in -O-(CH2)nO- is 2.

[0019] In addition, the compound of the present invention is preferably: as the connecting group X containing the methylene spacer in the general formula (1), -(CH2)n- is replaced by -O-(CH2)nO-, and n in -O-(CH2)nO- represents 3 to 10.

[0020] In addition, the compound of the present invention is preferably: as the connecting group X containing the methylene spacer in the general formula (1), -(CH2)n- is replaced by -O-(CH2)n-, and n in -O-(CH2)n- represents 2 to 10.

[0021] In addition, the compound of the present invention is preferably: as the linking group X containing the methylene spacer in the general formula (1), -(CH2)n- is replaced by -(CH2)nO-, and n in -(CH2)nO- represents 2 to 10.

[0022] In addition, in the compound of the present invention, it is preferred that: in the general formula (1), the b and the c are 1 or 0 respectively, or the b and the c are both 0.

[0023] In addition, the present invention provides a liquid crystal composition comprising one or more of the above compounds. The liquid crystal composition of the present invention preferably further comprises an ultraviolet curable monomer having multiple functional groups at a ratio of 0.2% to 0.5%.

[0024] Furthermore, the present invention provides a liquid crystal display element using the aforementioned liquid crystal composition. The liquid crystal display element of the present invention is preferably a multi-domain vertical alignment (MVA), polymer sustained alignment (PSA), in-plane switching (IPS) or fringe field switching (FFS) type.

[0025] Effects of the Invention

[0026] The compound of the present invention comprises 2 parts separated by the methylene spacer with more than 2 carbon atoms in 1 molecule, and each part has more than 2 fluorine groups, and the vector sum of the dipole moment in each part is toward the direction perpendicular to the molecular axis. Since the methylene spacer can rotate freely, each part responds independently to a certain extent relative to the applied electric field. Therefore, the compound of the present invention shows more negative dielectric constant anisotropy and low rotational viscosity. In this way, when designing the composition of the dielectric constant anisotropy of the required liquid crystal composition, the compound of low rotational viscosity with low viscosity of about 0 can be used in a larger amount, and low viscosity, liquid crystal composition with high speed responsiveness of low rotational viscosity can be made. And the liquid crystal display element using the liquid crystal composition of the present invention is particularly suitable for providing the liquid crystal display element for liquid crystal television and liquid crystal display requiring high speed response. DETAILED DESCRIPTION

[0027] The present invention will be described in detail below, but the present invention is not limited to these descriptions. As examples of more preferred compounds of the present invention, the following structural formulas (1-1) to (1-30) corresponding to the general formula (1) can be cited.

[0028]

[0029] (Where R 1 and R 2 and R in the general formula (1) 1 and R 2 Meanings the same.)

[0030] The R 1 It is preferably an alkyl or alkenyl group having 1 to 5 carbon atoms, more preferably an ethyl, propyl, vinyl or propenyl group, wherein R2 Preferred is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a 3-butenyl group, a 3-pentenyl group, a 2-propenyloxy group or a 2-butenyloxy group, and more preferred is a methyl group, an ethyl group, a propyl group, a methoxy group or an ethoxy group.

[0031] The liquid crystal composition of the present invention contains one or more of the aforementioned compounds of the present invention, and preferably contains, in addition to the aforementioned compounds, a previously known liquid crystal compound having a dielectric anisotropy (hereinafter also referred to as "Δε") of about 0 (approximately -2 to +2) and a previously known liquid crystal compound having a Δε more negative than -3 (i.e., a smaller Δε).

[0032] Preferred examples of conventionally known liquid crystal compounds having Δε of about 0 (approximately -2 to +2) contained in the liquid crystal composition of the present invention include the following structural formulas (2-1) to (2-6). It is preferred to contain one or more of them.

[0033]

[0034] (Where R 3 represents an alkyl group having 1 to 9 carbon atoms or an alkenyl group having 2 to 9 carbon atoms, R 4 represents an alkyl group or alkoxy group having 1 to 9 carbon atoms, or an alkenyl group having 3 to 9 carbon atoms, and preferably R 3 represents ethyl, propyl, vinyl or propenyl, R 4 represents an alkyl group or an alkoxy group having 1 to 5 carbon atoms. )

[0035] Preferred examples of conventionally known liquid crystal compounds having Δε more negative than -3 contained in the liquid crystal composition of the present invention include the following structural formulas (3-1) to (3-6), and it is preferred to contain one or more of them.

[0036]

[0037] (Where R 5 represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R 6 represents an alkyl group having 1 to 5 carbon atoms, and more preferably R 5 represents ethyl, propyl, vinyl or propenyl, R 6 represents a methyl or ethyl group. )

[0038] The liquid crystal display element using the liquid crystal composition of the present invention is preferably an MVA type, a PSA type, an IPS type or an FFS type. In particular, the vertically oriented MVA type and the PSA type are used as an optical element or a display element by sandwiching a liquid crystal material between two substrates, aligning the liquid crystal approximately perpendicular to the substrates, and applying an electric field approximately perpendicular to the substrates. The IPS type and the FFS type are also preferred, in which the liquid crystal is oriented approximately parallel to the substrates and approximately perpendicular to the electrodes.

[0039] When the liquid crystal composition of the present invention is used in a PSA type liquid crystal display element, it is preferred that the liquid crystal composition of the present invention contain a UV curable monomer at a ratio of 0.2% to 0.5%. The "ratio of 0.2% to 0.5%" is the ratio of the weight of the UV curable monomer contained in the liquid crystal composition relative to the total weight of the liquid crystal composition containing a plurality of compounds. When a liquid crystal display element is produced, the liquid crystal composition containing the UV curable monomer is irradiated with UV rays while applying an electric field, thereby separating the polymerized phase and stabilizing the slightly tilted orientation.

[0040] The ultraviolet curable monomer is also called a reactive liquid crystal original (mesogen), and is preferably a multifunctional monomer having a plurality of (more than 2) functional groups. In particular, it is more preferred that the ultraviolet curable monomer has 2 or 3 functional groups, and the 2 or 3 functional groups contain at least one of a methacryloyl group, an acryloyl group, and a cinnamoyl group.

[0041] Preferred examples of conventionally known ultraviolet curable monomers include the following structural formulas (5-1) to (5-5), and one or more of them are preferably contained.

[0042]

[0043] In addition, a liquid crystal display element using the present liquid crystal composition is suitable for use in liquid crystal televisions and liquid crystal monitors requiring high-speed response, and in-vehicle displays and PIDs (Public Information Display) requiring high-speed response at low temperatures.

[0044] [Example]

[0045] (Example 1)

[0046] In formula (1-1), R 1 =C3H7-, R 2 Synthesis of compounds containing =-OC2H5

[0047]

[0048] (In the above formula, DIAD represents diisopropyl azodicarboxylate, and TPP represents triphenylphosphine.)

[0049] 2,3-Difluoro-4-(trans-4-propylcyclohexyl)phenol (5.04g), 2-(4-ethoxy-2,3-difluorophenoxy)ethanol (2.16g) and triphenylphosphine (6.0g) were dissolved in THF (25mL) and cooled to -10°C. DIAD (4.4g) was added at a rate that did not cause the internal temperature to reach 15°C or above, and the mixture was stirred at room temperature for 2 hours. Water (1mL) was added and stirred for 10 minutes, and the reaction solution was concentrated under reduced pressure. Hexane (60mL), toluene (20mL) and 70% aqueous tert-butyl hydroperoxide solution (0.8g) were added and stirred at room temperature for 1 hour. The precipitate was removed and the solvent was removed by distillation under reduced pressure. It was then purified by gel permeation chromatography and recrystallized from ethanol to obtain 5.1g of the compound represented by formula (1-1-1) as a white solid.

[0050] The compound represented by formula (1-1-1) presents any one of the phases of crystalline phase, isotropic liquid phase, and nematic liquid crystal phase according to the temperature. The temperature at which the phase transition occurs is the phase transition temperature. The phase transition temperatures of the compound represented by formula (1-1-1) are measured, and the results are as follows. Wherein, C represents the crystalline phase, I represents the isotropic liquid phase, and N represents the nematic liquid crystal phase.

[0051]

[0052] (Example 2)

[0053] In formula (1-2), R 1 =C3H7-, R 2 Synthesis of compounds containing =-OC2H5

[0054] In the same manner as in Example 1, 4.9 g of the compound represented by the formula (1-2-1) was obtained.

[0055]

[0056] The compound represented by formula (1-2-1) also presents a crystalline phase, an isotropic liquid phase, and a nematic liquid crystal phase depending on the temperature. The phase transition temperatures of the compound represented by formula (1-2-1) were measured, and the results are as follows.

[0057]

[0058] (Example 3)

[0059] In formula (1-26), R 1 =C2H5O-, R 2 Synthesis of compounds containing =-OC2H5

[0060] In the same manner as in Example 1, 5.3 g of the compound represented by the formula (1-26-1) was obtained.

[0061]

[0062] The compound represented by formula (1-26-1) also presents any one of a crystalline phase, an isotropic liquid phase, and a nematic liquid crystal phase according to different temperatures. The phase transition temperatures of the compound represented by formula (1-26-1) were measured, and the results are as follows.

[0063]

[0064] (Example 4)

[0065] Liquid crystal composition (1) (hereinafter also referred to as "composition (1)") shown in Table 1 was prepared using the compounds of the present invention represented by formula (1-1-1) and formula (1-2-1). Table 1 shows the composition ratios of the compounds contained in the liquid crystal composition.

[0066] The physical properties of the liquid crystal composition (1) are as follows. The dielectric anisotropy (Δε) and the refractive index anisotropy (Δn) were measured at 25°C, and the viscosity (η 20 ) and rotational viscosity (γ1).

[0067] The upper limit temperature of the nematic phase (T n-i ): 80.2℃

[0068] Dielectric anisotropy (Δε): -3.3

[0069] Refractive index anisotropy (Δn): 0.11

[0070] Viscosity (η 20 ): 20.1mPa·s

[0071] Rotational viscosity (γ1): 122 mPa·s

[0072] (Example 5)

[0073] In the same manner as in Example 4, the liquid crystal composition (2) shown in Table 1 (hereinafter, also simply referred to as “composition (2)”) was prepared using the compounds of the present invention represented by formula (1-2-1) and formula (1-26-1).

[0074] The physical properties of the liquid crystal composition (2) are as follows.

[0075] The upper limit temperature of the nematic phase (T n-i ): 80.1℃

[0076] Dielectric anisotropy (Δε): -3.3

[0077] Refractive index anisotropy (Δn): 0.11

[0078] Viscosity (η 20 ): 17.3mPa·s

[0079] Rotational viscosity (γ1): 105mPa·s

[0080] (Example 6)

[0081] In the same manner as in Example 5, the liquid crystal composition (3) shown in Table 1 (hereinafter also referred to as “composition (3)”) was prepared using the compounds of the present invention represented by formula (1-2-1) and formula (1-26-1).

[0082] The physical properties of the liquid crystal composition (3) are as follows.

[0083] The upper limit temperature of the nematic phase (T n-i ): 80.3℃

[0084] Dielectric anisotropy (Δε): -3.3

[0085] Refractive index anisotropy (Δn): 0.11

[0086] Viscosity (η 20 ): 18.0mPa·s

[0087] Rotational viscosity (γ1): 103mPa·s

[0088] (Comparative Example 1)

[0089] As a comparative example of Example 4, a liquid crystal composition (4) shown in Table 1 (hereinafter, also simply referred to as “composition (4)”) composed of a conventional liquid crystal compound was prepared.

[0090] The physical properties of the liquid crystal composition (4) are as follows.

[0091] The upper limit temperature of the nematic phase (T n-i ): 80.1℃

[0092] Dielectric anisotropy (Δε): -3.3

[0093] Refractive index anisotropy (Δn): 0.11

[0094] Viscosity (η 20 ): 23.2mPa·s

[0095] Rotational viscosity (γ1): 145 mPa·s

[0096] (Comparative Example 2)

[0097] As a comparative example of Example 5, a liquid crystal composition (5) shown in Table 1 (hereinafter also referred to as “composition (5)”) composed of a conventional liquid crystal compound was prepared.

[0098] The physical properties of the liquid crystal composition (5) are as follows.

[0099] The upper limit temperature of the nematic phase (T n-i ): 80.3℃

[0100] Dielectric anisotropy (Δε): -3.3

[0101] Refractive index anisotropy (Δn): 0.11

[0102] Viscosity (η 20 ): 20.8mPa·s

[0103] Rotational viscosity (γ1): 140 mPa·s

[0104] (Comparative Example 3)

[0105] As a comparative example of Example 6, a liquid crystal composition (6) shown in Table 1 (hereinafter also referred to as “composition (6)”) composed of a conventional liquid crystal compound was prepared.

[0106] The physical properties of the liquid crystal composition (6) are as follows.

[0107] The upper limit temperature of the nematic phase (T n-i ): 80.0℃

[0108] Dielectric anisotropy (Δε): -3.3

[0109] Refractive index anisotropy (Δn): 0.11

[0110] Viscosity (η 20 ): 19.8mPa·s

[0111] Rotational viscosity (γ1): 114 mPa·s

[0112] Regarding the typical properties required of liquid crystal compositions used in PSA-type or MVA-type liquid crystal display devices for liquid crystal televisions, liquid crystal compositions (1) to (6) are all consistent in that the upper limit temperature of the nematic phase (T n-i)=80℃, dielectric constant anisotropy (Δε)=-3.3, refractive index anisotropy (Δn)=0.11. Furthermore, the composition (1) of Example (4) and the composition (4) of Comparative Example (1) are composed of the same liquid crystal compound except the compound of the present invention. Similarly, the composition (2) of Example (5) and the composition (5) of Comparative Example (2), and the composition (3) of Example (6) and the composition (6) of Comparative Example (3) are all composed of the same liquid crystal compound except the compound of the present invention.

[0113] Table 1

[0114] Compound Embodiment (4) Comparative Example (1) Embodiment (5) Comparative Example (2) Embodiment (6) Comparative Example (3) Composition (1) Composition (4) Composition (2) Composition (5) Composition (3) Composition (6) Formula (2-1-1) 20 20 Formula (2-1-2) 8 8 Formula (2-1-3) 7 5 Formula (2-1-4) 30 25 28 28 Formula (2-1-5) 4 4 8 3 Formula (2-6-1) 8 5 5 5 6 6 Formula (2-3-1) 4 4 7 7 3 5 Formula (3-1-1) 8 12 9 12 Formula (3-1-2) 4 5 4 6 Formula (3-5-1) 3 5 Formula (3-5-2) 6 12 Formula (3-3-1) 7 12 9 12 Formula (3-3-2) 4 7 5 7 Formula (3-4-1) 6 7 7 7 4 7 Formula (3-4-2) 8 8 3 8 8 8 Formula (3-4-3) 6 7 Formula (3-6-1) 3 3 Formula (3-6-2) 10 14 Formula (4-1-1) 5 5 7 6 Formula (4-1-2) 2 2 4 3 Formula (1-1-1) 4 Formula (1-2-1) 6 4 4 Formula (1-26-1) 6 6

[0115] The compounds of formula (2-1-1), formula (2-1-2), formula (2-1-3), formula (2-1-4), formula (2-1-5), formula (2-6-1), and formula (2-3-1) in Table 1 represent the following compounds.

[0116]

[0117] The compounds of formula (3-1-1), formula (3-1-2), formula (3-5-1), formula (3-5-2), formula (3-3-1), formula (3-3-2), formula (3-4-1), formula (3-4-2), formula (3-4-3), formula (3-6-1), and formula (3-6-2) in Table 1 represent the following compounds.

[0118]

[0119] The compounds of formula (4-1-1) and (4-1-2) in Table 1 represent the following compounds.

[0120]

[0121] The rotational viscosity (γ1) of the composition (1) of Example (4) is 122 mPa·s, which is significantly lower than the rotational viscosity (γ1) of the composition (4) of Comparative Example (1) of 145 mPa·s. Similarly, the rotational viscosity of the composition (2) of Example (5) is 105 mPa·s, which is lower than the 140 mPa·s of Comparative Example (2), and the rotational viscosity of the composition (3) of Example (6) is 103 mPa·s, which is lower than the 114 mPa·s of Comparative Example (3). It can be seen from these values ​​that the liquid crystal compound of the present invention and its liquid crystal composition are effective in high-speed responsiveness.

Claims

1. A compound, characterized in that having a predetermined negative dielectric anisotropy, comprising two sites separated by a predetermined spacer having at least carbon atoms, wherein the molecular axes starting from the bonding portion between the spacer and each of the sites and along the direction toward the end of each of the sites are respectively predetermined, The spacer is a methylene spacer having 2 or more carbon atoms in one molecule, Each of the sites has at least two fluorine groups, and is configured so that the vector sum of the dipole moment of each of the sites is oriented in a direction perpendicular to each of the molecular axes. The negative dielectric anisotropy is more negative than -4, The compound is represented by the following general formula (1): In the formula, R 1 and R 2 represents an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, an alkenyl group having 2 to 9 carbon atoms, or an alkenyloxy group having 2 to 9 carbon atoms, a represents 0 or 1, b represents 0 or 1, c represents 0, d represents 0, and ring A and ring B represent any one of the following structural formulas (a-1) to (a-4), Z 1 Represents a single bond, Z 2 represents -CH2O-, -OCH2-, -COO-, -OCO-, -CH2CH2-, -CF2CF2-, -CH=CH-, -CF=CF-, -C≡C- or a single bond, The two sites are from the atom bonded to one end of the methylene spacer contained in the linker X to the atom connected to the R 1 A series of sites as the terminal, and from the atom bonded to the other end of the methylene spacer contained in the linker X to the atom ending with R 2 As a series of parts at the end, The linking group X containing the methylene spacer in the general formula (1) represents -(CH2)nO-, and n represents 2 to 10.

2. The compound according to claim 1, wherein the ring A in the general formula (1) is a cyclohexane ring of the structural formula (a-1) or a benzene ring of the structural formula (a-2).

3. A liquid crystal composition comprising at least one or two or more of the compounds according to claim 1 or 2.

4. The liquid crystal composition according to claim 3, further comprising one or more compounds represented by the following structural formulas (2-1) to (2-6), and one or more compounds represented by the following structural formulas (3-1) to (3-6), In the formula, R 3 represents an alkyl group having 1 to 9 carbon atoms or an alkenyl group having 2 to 9 carbon atoms, R 4 represents an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or an alkenyl group having 3 to 9 carbon atoms, In the formula, R 5 represents an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, R 6 It represents an alkyl group having 1 to 5 carbon atoms.

5. The liquid crystal composition according to claim 4, wherein the R 3 is ethyl, propyl, vinyl or propenyl, The R in the structural formula (2-1) to the structural formula (2-6) 4 is an alkyl group or an alkoxy group having 1 to 5 carbon atoms, The R in the structural formula (3-1) to the structural formula (3-6) 5 is ethyl, propyl, vinyl or propenyl, The R in the structural formula (3-1) to the structural formula (3-6) 6 It is methyl or ethyl.

6. The liquid crystal composition according to any one of claims 3 to 5, further comprising an ultraviolet curable monomer having a plurality of functional groups in a ratio of 0.2% to 0.5%. 7 . The liquid crystal composition according to claim 6 , wherein the ultraviolet curable monomer has two or three of the functional groups, and the two or three of the functional groups include at least one of a methacryloyl group, an acryloyl group, and a cinnamoyl group. 8 . The liquid crystal composition according to claim 7 , comprising, as the ultraviolet curable monomer, one or two or more compounds represented by the following structural formulas (5-1) to (5-5). 9 . A liquid crystal display element using the liquid crystal composition according to claim 3 .

10. The liquid crystal display element according to claim 9, which is of MVA type (multi-quadrant vertical alignment type), PSA type (polymer stabilized alignment type), IPS type (in-plane switching type), or FFS type (fringe field switching type).

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