TW201739903A - Liquid crystal composition - Google Patents

Abstract

The invention discloses a liquid crystal composition. The liquid crystal composition comprises one or more types of compounds shown as formula I and one or more types of compounds shown as formula II; the liquid crystal composition comprises a compound shown as formula II-B in one or two types of compounds shown as the formula II of the description, wherein each substituent group is defined. The composition provided by the invention has low viscosity [gamma]1, moderate dielectric anisotropy [Delta][epsilon] and moderate optical anisotropy [Delta]n, and can realize rapid response of liquid crystal display.

Description

Liquid crystal composition and liquid crystal display element

The present invention relates to the field of liquid crystal display, and more particularly to a liquid crystal composition and a liquid crystal display element or liquid crystal display comprising the liquid crystal composition.

At present, the application range of liquid crystal compounds is expanding wider and wider, and it can be applied to various types of displays, electro-optical devices, sensors, and the like. There are many kinds of liquid crystal compounds used in the above display field, and the nematic liquid crystal is most widely used. Nematic liquid crystals have been used in passive TN, STN matrix displays and systems with TFT active matrices.

For the application of thin film transistor technology (TFT-LCD), although the market has been very large in recent years, and the technology has gradually matured, people's requirements for display technology are also constantly improving, especially in achieving fast response and lowering the driving voltage. Reduce power consumption and other aspects. As one of the important optoelectronic materials for liquid crystal displays, liquid crystal materials play an important role in improving the performance of liquid crystal displays.

As a liquid crystal material, it is required to have good chemical and thermal stability as well as stability against electric fields and electromagnetic radiation. As a liquid crystal material for thin film transistor technology (TFT-LCD), it is not only required to have the above stability, but also has a wide nematic phase temperature range, a suitable birefringence anisotropy, a very high resistivity, Good UV resistance, high charge retention and low vapor pressure.

For the dynamic picture display application, eliminating the image sticking and smearing of the display, the liquid crystal is required to have a fast response speed, so the liquid crystal is required to have a low rotational viscosity γ ₁ ; in addition, for the portable device, in order to reduce the energy consumption of the device, it is desirable for the liquid crystal The driving voltage is as low as possible; for a display such as a television, the driving voltage requirement for the liquid crystal is not so low.

The viscosity of the liquid crystal compound, especially the rotational viscosity γ ₁ directly affects the response time after the liquid crystal is powered on, whether it is the rise time (t _on ) or the fall time (t _off ), which is proportional to the rotational viscosity γ ₁ of the liquid crystal, and rises. The time (t _on ) is related to the liquid crystal cell and the driving voltage, and can be adjusted by increasing the driving voltage and reducing the thickness of the liquid crystal cell; and the falling time (t _off ) is independent of the driving voltage, mainly the elasticity of the liquid crystal. The constant is related to the thickness of the liquid crystal cell, and the drop in the thickness of the cell reduces the fall time (t _off ). In different display modes, the liquid crystal molecules move in different ways. The fall times (t _off ) of the three modes of TN, IPS, and VA are respectively It is inversely proportional to the average elastic constant K, the torsional elastic constant, and the bending elastic constant.

According to the theory of liquid crystal continuum, after different kinds of liquid crystals are deformed by external force (electric field, magnetic field), they will "rebound" back to the original shape by interaction between molecules; similarly, liquid crystals are also due to intermolecular The interaction forces form a "viscosity." Small changes in liquid crystal molecules can cause significant changes in the performance of liquid crystals. Some of these changes are regular, and some seem to be difficult to find. They also have a significant impact on the interaction between liquid crystal molecules. These effects are very Subtle, so far has not formed a perfect theoretical explanation.

The viscosity of liquid crystals is related to the molecular structure of liquid crystals. It is one of the important tasks of liquid crystal formulators to study the relationship between the viscosity of liquid crystal systems formed by different liquid crystal molecules and the molecular structure of liquid crystals.

An object of the present invention is to provide a liquid crystal composition and a liquid crystal display element or liquid crystal display comprising the liquid crystal composition, which has a low viscosity, can achieve a fast response, and has a moderate dielectric anisotropy Δ ε, Moderate optical anisotropy Δn, high stability to heat and light. A liquid crystal display element or liquid crystal display comprising the liquid crystal composition has a wide nematic phase temperature range, suitable birefringence anisotropy, very high resistivity, good ultraviolet resistance, high charge retention, and low steam Pressure and other properties.

In order to achieve the above advantageous technical effects, the present invention provides a liquid crystal composition comprising one or more compounds of the formula I and one or more compounds of the formula II, and the liquid crystal composition comprises one or Two of the compounds of formula II-B from the compounds of formula II: I II II-B,

Wherein R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 10 carbon atoms;

R ₂ and R ₃ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted carbon. An alkoxy group having an atomic number of 1 to 10, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms substituted by fluorine, an alkenyloxy group having 3 to 8 carbon atoms Or a fluorine-substituted alkenyloxy group having 3-8 carbon atoms, and any one or more of the discontinuous CH _{2 of} R ₂ and R ₃ may be cyclopentyl, cyclobutyl, cyclopropyl or O substitution;

Y represents an ethyl group or a vinyl group;

, Each independently represents 1,4-phenyl, 1,4-cyclohexyl or 1,4-cyclohexenyl.

The liquid crystal composition provided by the present invention necessarily comprises one or more compounds represented by formula I and one or two compounds represented by formula II-B, and may further comprise one or more compounds of formula II. a compound other than -B.

The liquid crystal composition of the present invention preferably does not contain a liquid crystal compound containing -CN, and does not contain a compound containing a pyridine or a pyrimidine ring.

The present invention is further preferably a liquid crystal compound which does not contain a fused ring structure.

The liquid crystal composition provided by the present invention has a Δn [589 nm, 25 ° C] > 0.08, Δ ε [1 KHz, 25 ° C] > 2 or Δ ε [1 KHz, 25 ° C] <-2, clearing point Cp > 55.0 ° C, rotational viscosity γ ₁ [25 ° C] is between 40 and 120 mPa·s.

The total mass content of the one or more compounds of the formula I in the liquid crystal composition provided by the present invention is preferably from 2 to 25%, and the total mass content of the one or more compounds represented by the formula II is preferably 5-85%, the total mass content of the one or two compounds represented by the formula II-B is preferably from 5 to 55%.

The liquid crystal composition of the present invention does not contain a liquid crystal component containing a -CN structure and a pyridine or pyrimidine ring compound. -CN has a large permanent dipole moment, and the electron cloud is rich. It is easy to adsorb cations and cause ion solvation, which reduces the electrical properties of the liquid crystal, such as charge retention rate VHR, resistivity ρ, power consumption, etc.; pyridine, pyrimidine ring compound Since electrons are easily excited under UV, the quality is degraded.

Depending on the various substituents, one or more compounds of formula I are preferably one or more of the compounds of formulas I1 to I5: I1 I2 I3 I4 I5.

The compounds of formula I generally have good mutual solubility with other liquid crystals; the optical anisotropy Δn of the compound of formula I is generally moderate, generally greater than or close to Δn of the mixed liquid crystal; the compound of formula I has a negative dielectric anisotropy Δε, suitable for In order to reduce the Δ ε of the mixed liquid crystal.

The liquid crystal composition of the present invention preferably contains one or both of the compounds represented by the formula II-B-1 or the compound represented by the formula II-B-2: II-B-1 II-B-2.

The liquid crystal composition provided by the present invention may further comprise one or more compounds represented by the formulae II-1 to II-10: II-1 II-2 II-3 II-4 II-5 II-6 II-7 II-8 II-9 II-10.

The liquid crystal composition of the present invention may be a positive liquid crystal composition, and the liquid crystal composition may further comprise one or more compounds represented by formula III: III,

Wherein R ₄ represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a fluorine-substituted carbon atom of 1 Alkoxy group of -10, alkenyl group having 2 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms substituted by fluorine, alkenyloxy group having 3 to 8 carbon atoms or fluorine substituted An alkenyloxy group having 3 to 8 carbon atoms; and any CH _{2 of} R ₄ may be replaced by a cyclopentyl group, a cyclobutyl group or a cyclopropyl group.

, , Each independently represents:

, , , , , , , One or two of them;

m represents 1, 2;

Z ₁ and Z ₂ each independently represent a single bond, -CF ₂ O-, -CH ₂ CH ₂ -, -CH ₂ O-;

Y ₁ represents F, a fluorine-substituted alkyl group having 1 to 5 carbon atoms, a fluorine-substituted alkoxy group having 1 to 5 carbon atoms, a fluorine-substituted alkenyl group having 2 to 5 carbon atoms, and fluorine. The substituted alkenyloxy group having 3-8 carbon atoms.

The one or more compounds represented by formula III are preferably one or more of the compounds represented by III1 to III21: III1 III2 III3 III4 III5 III6 III7 III8 III9 III10 III11 III12 III13 III14 III15 III16 III17 III18 III19 III20 III21 III22,

Wherein X ₁ represents H, X ₂ represents F or X ₁ represents F, and X ₂ represents H;

R ₄ each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a fluorine-substituted carbon atom. An alkoxy group of 1 to 10, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms substituted by fluorine, an alkenyloxy group having 3 to 8 carbon atoms or fluorine carbon atoms is substituted with 3-8 alkenyloxy group, and said R _{4 is} CH ₂ can be any one of cyclopentyl, cyclobutyl, cyclopropyl substitution;

(F) each independently representing H or F;

Y ₁ represents F, a fluorine-substituted alkyl group having 1 to 5 carbon atoms, a fluorine-substituted alkoxy group having 1 to 5 carbon atoms, a fluorine-substituted alkenyl group having 2 to 5 carbon atoms, and fluorine. The substituted alkenyloxy group having 3-8 carbon atoms.

As another preferred embodiment, the liquid crystal composition provided by the present invention may also be a negative liquid crystal composition, and the liquid crystal composition may further comprise one or more compounds represented by Formula IV: IV,

Wherein R ₅ and R ₆ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine substitution. An alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms substituted by fluorine, and an alkene having 3 to 8 carbon atoms An oxy or fluoro substituted alkenyloxy group having 3-8 carbon atoms, and any one of the R ₂ and R ₆ CH ₂ may be replaced by a cyclopentyl group, a cyclobutyl group or a cyclopropyl group;

Z ₃ and Z ₄ each independently represent a single bond, -CH ₂ CH ₂ - or -CH ₂ O-;

, Respectively , , , , , , One or two of them;

m represents 1 or 2;

n represents 0, 1, or 2.

The one or more compounds represented by Formula IV are preferably compounds represented by Formulas IV1 to IV11: IV1 IV2 IV3 IV4 IV5 IV6 IV7 IV8 IV9 IV10 IV11,

Wherein R ₅ and R ₆ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine substitution. An alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms substituted by fluorine, and an alkene having 3 to 8 carbon atoms The oxy or fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms, and any of the R ₂ and R ₆ CH ₂ may be replaced by a cyclopentyl group, a cyclobutyl group or a cyclopropyl group.

The liquid crystal composition provided by the present invention is preferably a negative liquid crystal composition, and may further comprise one or more compounds represented by formula V: V,

Wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine substitution. An alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms substituted by fluorine, and an alkene having 3 to 8 carbon atoms The oxy or fluoro substituted alkenyloxy group having 3-8 carbon atoms, and any one of the R ₇ and R ₈ CH ₂ may be replaced by a cyclopentyl group, a cyclobutyl group or a cyclopropyl group.

The compound represented by the formula V is preferably: ,

R ₈₁ represents an alkoxy group having 1 to 10 carbon atoms.

The different ratios of the components of the liquid crystal composition may exhibit slightly different properties, such as dielectric anisotropy Δε, optical anisotropy Δn, transition temperature point CP of liquid crystal into liquid, and stability at low temperature. It will vary and can be applied to different types of display devices, but the same feature is that its rotational viscosity γ _{1 is} lower. It can be applied to liquid crystal display devices to achieve fast response.

The liquid crystal compound provided by the invention may also be added with dopants of various functions, and the dopant content is preferably between 0.01 and 1%. These dopants are mainly antioxidants, ultraviolet absorbers, and palmitic agents.

The antioxidant and the ultraviolet absorber are preferably: , , , , , ,

S represents an integer of 1-10.

Preferably, the palmitic agent is (left-handed or right-handed): , , , ,

The invention further relates to a liquid crystal display element or liquid crystal display comprising any of the above liquid crystal compositions; the display element or display being an active matrix display element or display or passive matrix display element or display.

The liquid crystal display element or liquid crystal display is preferably an active matrix addressed liquid crystal display element or a liquid crystal display.

The active matrix display element or display is specifically a TN-TFT or IPS-TFT or VA-TFT liquid crystal display element or display.

The liquid crystal composition provided by the present invention has a low viscosity, can achieve a fast response, and has moderate dielectric anisotropy Δ ε, moderate optical anisotropy Δn, and high stability against heat and light.

The liquid crystal material comprising the liquid crystal composition provided by the present invention not only has good chemical and thermal stability and stability against electric fields and electromagnetic radiation. Moreover, as a liquid crystal material for thin film transistor technology (TFT-LCD), it also has a wide nematic phase temperature range, suitable birefringence anisotropy, very high resistivity, good ultraviolet resistance, and high charge. Maintainability and low vapor pressure.

The invention is further illustrated by the following specific examples, but the invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The raw materials can be obtained from an open commercial route unless otherwise specified. The percentages are all percentages by mass unless otherwise stated.

In the following embodiments,

CP indicates the clearing point and was directly measured using a WRX-1S micro-thermal analyzer, and the heating rate was set to 3 ° C / min.

Δn represents optical anisotropy (589 nm, 20oC),

Δε represents dielectric anisotropy (25 ° C, 1 KHz, HP 4284 A, 5.2 μm TN left-handed box),

γ ₁ represents rotational viscosity (mpas) at 20 ^o C, VHR (%) represents charge retention (5V, 60Hz, 20°C), and ρ (×1013Ω·cm) represents resistivity (20°C)

The tester with voltage holding ratio VHR(%) and resistivity ρ(×10 ¹³ Ω·cm) are both TOYO06254 and TOYO6517 liquid crystal physical property evaluation systems (test temperature 20 ° C, time 16 ms, test box 7.0 μm)

The liquid crystal monomer structure of the embodiment of the present invention is represented by a code, and the code representation methods of the liquid crystal ring structure, the terminal group and the linking group are shown in the following table (1) and Table (2).

Table (1): Corresponding code of the ring structure

Table (2): Corresponding code of end group and linking group

Example: C(5)CCV1 3B B(3F) B(3F,5F)QB(3F,5F)F

Example 1

Comparative example 1

The 2OBB(2F,3F)O2 of the formula I of Example 1 was changed to the common 2BB(2F,3F)O2 to obtain a comparative liquid crystal composition, which can be seen by parameter comparison: Δε of the comparative example decreases, Cp, Δn Decline, γ ₁ rises. It is apparent that the liquid crystal composition of the present invention has an advantage of a wider nematic phase temperature range and a faster response speed than the prior art.

Example 2

Example 3

Example 4

Example 5

Example 6

It can be seen from the above examples that the liquid crystal composition of the present invention has a low rotational viscosity γ1 for liquid crystal display and can achieve a fast response. It is especially suitable for liquid crystal materials for TN and IPS modes.

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Claims (10)

A liquid crystal composition comprising one or more compounds of formula I and one or more compounds of formula II, and the liquid crystal composition comprising one or two compounds of formula II -B compound: I II II-B, wherein R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 5 carbon atoms; and R ₂ and R ₃ each independently represent an alkyl group having 1 to 10 carbon atoms and a fluorine substitution. An alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or an alkenyloxy group having 3 to 8 carbon atoms substituted by fluorine, and optionally, Any one or more of the discontinuous CH _{2 of} R ₂ , R ₃ may be replaced by a cyclopentyl group, a cyclobutyl group, a cyclopropyl group, or O; the Y system represents an ethyl group or a vinyl group; , Each independently represents 1,4-phenyl, 1,4-cyclohexyl or 1,4-cyclohexenyl. The liquid crystal composition according to claim 1, wherein one or more compounds represented by the formula I are one or more compounds of the compounds represented by the formulas I1 to I5; one or more of the formula II The compound comprises one or more compounds from the compounds of the formulae II1 to II10; one or two compounds represented by the formula II-B are compounds represented by the formula II-B-1, II-B-2 One or two compounds, I1 I2 I3 I4 I5 II-B-1 II-B-2 II-1 II-2 II-3 II-4 II-5 II-6 II-7 II-8 II-9 II-10. The liquid crystal composition according to claim 1 or 2, wherein one or more of the liquid crystal compositions have a total mass content of the compound of the formula I of 2 to 25%, one or more of The total mass content of the compound represented by II is 5 to 85%, and the total mass content of one or two compounds represented by the formula II-B is 5 to 55%. The liquid crystal composition according to claim 1, wherein the liquid crystal composition is a positive liquid crystal composition, the liquid crystal composition further comprising one or more compounds represented by the formula III: III, wherein R ₄ represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorine-substituted carbon atom. Alkoxy groups of 1 to 10, alkenyl groups having 2 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms substituted by fluorine, alkenyloxy groups having 3 to 8 carbon atoms or Fluorine substituted alkenyloxy group having 3-8 carbon atoms, and optionally, any CH _{2 of} the R ₄ may be replaced by cyclopentyl, cyclobutyl or cyclopropyl; , , The departments independently represent: , , , , , , One or two; m represents 1 or 2; Z ₁ and Z ₂ each independently represent a single bond, -CF ₂ O-, -CH ₂ CH ₂ - or -CH ₂ O-; Y ₁ represents F a fluorine-substituted alkyl group having 1 to 5 carbon atoms, a fluorine-substituted alkoxy group having 1 to 5 carbon atoms, a fluorine-substituted alkenyl group having 2 to 5 carbon atoms, or a fluorine-substituted carbon atom; The number 3-8 is an alkenyloxy group. The liquid crystal composition according to claim 4, wherein one or more compounds represented by the formula III are one or more of the compounds represented by the formulae III1 to III22: III1 III2 III3 III4 III5 III6 III7 III8 III9 III10 III11 III12 III13 III14 III15 III16 III17 III18 III19 III20 III21 III22, wherein X ₁ represents H, X ₂ represents F or X ₁ represents F, and X ₂ represents H; R ₄ each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted carbon. An alkyl group having 1 to 10 atoms, an alkoxy group having 1 to 10 carbon atoms, a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or fluorine a substituted alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 3 to 8 carbon atoms or an alkenyloxy group having 3 to 8 carbon atoms substituted by fluorine, and optionally, R Any one of ₄ CH ₂ may be replaced by a cyclopentyl group, a cyclobutyl group, or a cyclopropyl group; (F) each independently represents H or F; Y ₁ means that F, a fluorine-substituted carbon atom is 1-5 The alkyl group or the fluorine-substituted alkoxy group having 1 to 5 carbon atoms, the fluorine-substituted alkenyl group having 2 to 5 carbon atoms, and the fluorine-substituted alkenyloxy group having 3 to 8 carbon atoms. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition is a negative liquid crystal composition, the liquid crystal composition further comprising one or more compounds represented by formula IV: IV, wherein R ₅ and R ₆ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms; a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, and 3 to 8 carbon atoms; carbon atoms an alkenyloxy group or fluorine-substituted 3-8 alkenyloxy group, and optionally, the R _5, R ₆ CH ₂ may be any one of cyclopentyl, cyclobutyl, or cyclic a propyl substitution; Z ₃ , Z ₄ each independently represents a single bond, -CH ₂ CH ₂ - or -CH ₂ O-; , Respectively , , , , , , One or two; m means 1 or 2; n means 0, 1 or 2. The liquid crystal composition according to claim 6, wherein the one or more compounds represented by the formula IV are one or more of the compounds represented by the formulae IV1 to IV11: IV1 IV2 IV3 IV4 IV5 IV6 IV7 IV8 IV9 IV10 IV11, wherein R ₅ and R ₆ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, and 3 to 8 carbon atoms; An alkenyloxy group or a fluorine-substituted alkenyloxy group having 3-8 carbon atoms, and optionally, any one of the R ₂ and R ₆ CH ₂ groups may be a cyclopentyl group, a cyclobutyl group, or a ring. Propyl substitution. The liquid crystal composition according to claim 1 or 2, wherein the liquid crystal composition is a negative liquid crystal composition, the liquid crystal composition further comprising one or more compounds represented by formula V: V, wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorine-substituted alkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms; a fluorine-substituted alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a fluorine-substituted alkenyl group having 2 to 10 carbon atoms, and 3 to 8 carbon atoms; carbon atoms an alkenyloxy group or fluorine-substituted 3-8 alkenyloxy group, and optionally, the R _7, R ₈ CH ₂ any one may be cyclopentyl, cyclobutyl, or cyclic Propyl substitution. A liquid crystal display element comprising the liquid crystal composition according to any one of claims 1 to 8, wherein the liquid crystal display element is an active matrix display element or a passive matrix display element. The liquid crystal display device of claim 9, wherein the active matrix display element is a TN-TFT, IPS-TFT or VA-TFT liquid crystal display element.