Liquid crystal composition with low viscosity, wide working temperature and low threshold voltage and application

Abstract

The invention discloses a liquid crystal composition with low viscosity, wide working temperature and low threshold voltage and application thereof. The liquid crystal composition comprises one or more compounds as shown in a structural general formula I and one or more compounds as shown in a structural general formula II. The liquid crystal composition disclosed by the invention not only can obtain relatively large dielectric tuning rate, relatively low dielectric loss, extremely low rotary viscosity and relatively low threshold voltage under high frequency, but also has the excellent characteristics of relatively wide nematic phase working temperature range, relatively large low-frequency dielectric constant and the like. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid crystal materials, and particularly relates to a liquid crystal composition and a high-frequency component containing the same, which are mainly applicable to fields such as filters, tunable frequency selective surfaces, microwave phase shifters, microwave phased array antennas, etc. Background Art

[0002] Liquid crystal materials have been widely used in optoelectronic display devices, such as various liquid crystal TVs, desktop liquid crystal displays, mobile display terminals, etc.

[0003] By utilizing the property that the effective dielectric constant of liquid crystal materials changes under the action of an externally applied electric field or magnetic field, new high-frequency (1 GHz - 100 GHz) components based on liquid crystal materials have been developed, such as microwave phase shifters based on liquid crystal materials.

[0004] In a microwave phase shifter, the dielectric tuning rate (also called dielectric tunability) of the liquid crystal material determines the tuning ability of the microwave device. For a liquid crystal material, its dielectric tuning rate (τ) is determined by the dielectric anisotropy (Δε) of the liquid crystal material at high frequencies and the dielectric constant (ε ∥ ) in the molecular parallel direction:

[0005] τ = Δε / ε ∥

[0006] The dielectric loss of the liquid crystal material is an important factor affecting the insertion loss of its microwave device. In order to obtain a high-performance liquid crystal microwave device, it is necessary to reduce the dielectric loss of the liquid crystal material. For a liquid crystal material, the tangent of the loss angle varies with the direction of the liquid crystal molecule's orientation with respect to the electric field direction, that is, the losses in the long-axis and short-axis directions of the liquid crystal molecule are different. When calculating the loss of the liquid crystal material, generally its maximum loss, that is, max(tanδ ∥ , tanδ ⊥ ) is used as the loss of the liquid crystal material.

[0007] In order to comprehensively evaluate the performance parameters of the liquid crystal material under microwaves, a quality factor (η) parameter is introduced:

[0008] η = τ / max(tanδ ∥ , tanδ ⊥ )

[0009] The liquid crystal material used for high-frequency components is required to have a large dielectric tuning rate (τ), low loss (tanδ ∥ , tanδ ⊥ ), and high quality factor (η).

[0010] With the rapid development of high, medium, and low Earth orbit satellite communication technologies, for mobile communication antennas that track low Earth orbit satellites, fast microwave beam switching speeds are required. Therefore, high-frequency components based on liquid crystals must also possess the ability to respond quickly. The response speed of liquid crystals mainly depends on the cell thickness (d) of the liquid crystal device, the rotational viscosity (γ1) of the liquid crystal material, and the elastic constant (K 11 ), as follows:

[0011]

[0012]

[0013] where: t on is the on-state (power-on) response time, and t off is the off-state (power-off) response time; V th is the threshold voltage of the liquid crystal, and V is the applied driving voltage; when the cell thickness d is fixed, to improve the response speed of the liquid crystal device, the liquid crystal material must have a low rotational viscosity (γ1) and a large elastic constant (K 11 ), that is, a low viscosity-elastic constant ratio (γ1 / K 11 ).

[0014] To enable the high-frequency component to operate under electric field driving, especially at a relatively low voltage driving, and reduce power consumption, the liquid crystal material is also required to have a large dielectric anisotropy at low frequencies, such as 1 kHz, and a small threshold voltage V th . Additionally, a smaller threshold voltage is also beneficial for shortening the on-state response time t on .

[0015] To meet practical applications, the liquid crystal material used for high-frequency components also needs to have a wide operating temperature range, for example, maintaining the nematic phase within a temperature range of -20 to +120 °C.

[0016] Patents CN107955630A and CN105368465A disclose liquid crystal compositions with NCS groups at the molecular ends and fluorine-substituted benzene rings in the molecular backbone. Although they have a large dielectric constant and tuning rate at high frequencies, their dielectric loss values are large; in the disclosed embodiments, the dielectric loss tanδ ⊥ (19 GHz) is all above 0.01; at the same time, the rotational viscosity is large.

[0017] CN110499163A and US2019292458A1 disclose liquid crystal compositions with NCS groups at the molecular ends and fluorine-substituted benzene rings in the molecular backbone. In the disclosed embodiments, the rotational viscosity is large.

[0018] CN113528154A discloses a liquid crystal composition with an NCS group at the molecular end and a molecular skeleton of a methyl- or chlorine-substituted benzene ring. Although it has the advantage of extremely low dielectric loss, its rotational viscosity is relatively high, making it difficult to meet the requirements of fast response. Moreover, the dielectric anisotropy value at low frequencies is relatively low, resulting in a high threshold voltage and driving voltage, and an increased power consumption.

[0019] From the existing published literature, it can be seen that there are contradictions among the performance parameters of liquid crystal materials for microwaves. For some liquid crystals with low dielectric loss, their rotational viscosity and the ratio of rotational viscosity to elastic constant (γ1 / K 11 ) are often very large, unable to meet the requirements of fast response speed; there is also a relatively low dielectric anisotropy value at a low frequency of 1 KHz, resulting in a high threshold voltage. On the other hand, an increase in dielectric tunability often leads to an increase in rotational viscosity. In addition, the working temperature range of liquid crystals, especially the tendency to crystallize in a low-temperature environment, is also a technical problem that needs to be solved. SUMMARY OF THE INVENTION

[0020] Aiming at the defects or deficiencies of the prior art, the present invention provides a liquid crystal composition having the characteristics of low viscosity, wide working temperature range, low dielectric loss, and relatively low threshold voltage.

[0021] To this end, the liquid crystal composition provided by the present invention comprises one or more compounds selected from the compounds represented by structural formula I and one or more compounds selected from the compounds represented by structural formula II;

[0022]

[0023] In formula I:

[0024] R is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyloxy group having 2 to 10 carbon atoms, or an alkenyloxy group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom;

[0025] Z1 is a single bond, -C≡C-, -CH=CH-, -CF=CF-, or -CH2CH2, Z2 is a single bond, -C≡C-, -CH=CH-, -CF=CF-, or -CH2CH2, and at least one of Z1 and Z2 is -C≡C-;

[0026] Ring A is a benzene ring, a cyclohexane, a cyclohexene, or a benzene ring in which hydrogen is substituted by fluorine, chlorine, methyl, or / and ethyl;

[0027] Ring B is a benzene ring or a benzene ring in which hydrogen is substituted by fluorine, chlorine, methyl, or / and ethyl;

[0028] n = 0 or 1;

[0029]

[0030] In Formula II: R1 and R2 are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms.

[0031] Optionally, the liquid crystal composition comprises one or more compounds selected from the compounds represented by Structural Formulas I-1 to I-5 or the compound represented by Formula I is selected from the compounds represented by Structural Formulas I-1 to I-5:

[0032]

[0033] Optionally, the liquid crystal composition further comprises one or more compounds selected from Structural Formulas II-1 to II-2:

[0034]

[0035] In II-1 to II-2, each group of R3 is independently n-propyl, n-butyl or n-pentyl.

[0036] Further optionally, the mass percentage of the compound represented by Formula I is 70% to 95%; the mass percentage of the compound represented by Formula II is 5% to 30%.

[0037] In some other embodiments, the liquid crystal composition further comprises one or more compounds selected from Structural Formulas III-1 to III-2:

[0038]

[0039] In III-1 to III-2, each R4 is independently an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyloxy group having 2 to 10 carbon atoms or an alkenyloxy group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom. Further optionally, the mass percentage of the compound represented by Structural Formulas III-1 to III-2 is 0 to 30%.

[0040] In a preferred embodiment, the high-frequency 19 GHz vertical dielectric loss value tanδ of the liquid crystal composition ⊥≤0.015, the quality factor η ≥ 20; the rotational viscosity of the liquid crystal composition ≤ 350 mPa·s; the dielectric anisotropy Δη at low frequency of 1 KHz > 12, the threshold voltage < 1.3 v; the nematic phase temperature range is -20 to 100 °C or above. Further, the tuning rate τ of the liquid crystal composition ≥ 0.26. The splay elastic constant K of the liquid crystal composition 11 ≥ 15 pN, and γ1 / K of the liquid crystal composition 11 ≤ 20.

[0041] The liquid crystal composition of the present invention not only achieves a large dielectric tuning rate and low dielectric loss at high frequencies, but also has a low rotational viscosity, a wide nematic phase operating temperature range, a large low-frequency dielectric anisotropy, and a low threshold voltage, realizing the optimization and balance of comprehensive performance. The liquid crystal composition of the present invention can be used to prepare optoelectronic display devices and high-frequency components. Detailed Embodiments

[0042] Unless otherwise specified, the scientific and technical terms in this article are understood according to the knowledge of those of ordinary skill in the relevant fields.

[0043] In a preferred embodiment of the present invention, the liquid crystal composition comprises one or more compounds of structural formula I and one or more compounds of structural formula II.

[0044] According to the disclosure of the present invention, those skilled in the art can select appropriate components and ratios to achieve the effects of the present invention. In a preferred embodiment, the liquid crystal composition of the present invention, based on the total mass of the mixture, comprises 70% to 95% by mass, preferably 75% to 90% of the compound of formula I; and 5% to 30% by mass, preferably 10% to 25% of the compound of structural formula II. In a specific embodiment, those skilled in the art can make optimized selections based on the disclosure of the present invention.

[0045] The dielectric loss tangent tanδ in the vertical direction at high frequency of 19 GHz of the liquid crystal material of the present invention ⊥ ≤ 0.015, preferably tanδ ⊥ ≤ 0.012; the material quality factor η ≥ 20, preferably η ≥ 30; the nematic phase temperature range is -20 to 100 °C or above; the rotational viscosity γ1 ≤ 350 mPa·s, preferably ≤ 320 mPa·s; the dielectric constant Δη at low frequency of 1 KHz ≥ 12.0, more preferably ≥ 14.0. Further, the elastic constant K of the material of the present invention 11 ≥ 15 pN, more preferably K 11 ≥ 16 pN; preferably, γ1 / K of the liquid crystal composition 11 ≤ 20, more preferably γ1 / K of the liquid crystal composition 11≤18. Preferably, the tuning rate τ of the liquid crystal composition in the present invention is ≥0.26, more preferably ≥0.28.

[0046] The liquid crystal composition according to the present invention is composed of a plurality of compounds, preferably 3 to 20 compounds, more preferably 5 to 18 and even more preferably 7 to 15 compounds. These compounds can be mixed in a conventional manner: weigh various compounds according to a predetermined mass ratio, then heat up, and at the same time use magnetic stirring or ultrasonic stirring and other stirring methods for homogeneous mixing until all components are completely dissolved; then obtain it after filtration. The liquid crystal composition can also be prepared by other conventional methods, such as using a so-called premix, or using a so-called "multi-bottle" system, and the components in this system are ready-to-use mixtures themselves.

[0047] The compound of general formula I in the present invention not only has a low dielectric loss and a large dielectric anisotropy at high frequencies, but also has a very large dielectric anisotropy at low frequencies.

[0048] The molecular structure of general formula II in the present invention is composed of 2 rings, has the characteristics of low viscosity, low melting point and low dielectric loss, can improve the low-temperature performance of the liquid crystal composition, greatly reduce the viscosity of the liquid crystal composition, and at the same time reduce the dielectric loss.

[0049] In a further embodiment, the liquid crystal composition according to the present invention may further contain 0.001 to 1% of an additive, and the additive is selected from hindered phenol antioxidants or / and hindered amine light stabilizers, etc. Among them, the hindered phenol antioxidant is preferably selected from the following structures:

[0050]

[0051] In the above two structures, each of R' is independently an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms.

[0052] The hindered amine light stabilizer is preferably selected from the following structures:

[0053]

[0054] The mass percentage addition amount of the preferred hindered phenol antioxidant and hindered amine light stabilizer in the liquid crystal composition is 0.01% to 0.5%, more preferably 0.02% to 0.2%.

[0055] In some further embodiments, the liquid crystal composition of the present invention may further contain one or more chiral additives, and the content is 0.01% to 1%; preferably 0.1% to 0.5%. The chiral additive is preferably selected from the following structures:

[0056]

[0057] Each R″ in the above formula is independently an alkyl group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms.

[0058] The liquid crystal composition according to the present invention is suitable for preparing high-frequency components, such as microwave components, more specifically, a phase shifter that can be tuned by applying an external magnetic field or electric field. These phase shifters can operate in the UHF-band (0.3 - 1 GHz), L-band (1 - 2 GHz), S-band (2 - 4 GHz), C-band (4 - 8 GHz), X-band (8 - 12 GHz), Ku-band (12 - 18 GHz), K-band (18 - 27 GHz), Ka-band (27 - 40 GHz), V-band (50 - 75 GHz), W-band (75 - 110 GHz) and up to 1 THz. The construction of the phase shifter according to the present application is known to those skilled in the art. Typically, loaded line phase shifters, inverted microstrip lines, finline phase shifters, preferably antipodal finline phase shifters, slotted phase shifters, microstrip line phase shifters or coplanar waveguide (CPW) phase shifters are used. These components can realize a reconfigurable antenna array.

[0059] The performance (dielectric constant, dielectric loss) of the liquid crystal composition herein at high frequencies is measured using the test method reported in the literature (Penirschke, A. (2004). Cavity perturbation method for characterization of liquid crystals up to 35 GHz. Microwave Conference,2004.34th European .): The liquid crystal is introduced into a polytetrafluoroethylene (PTFE) or fused silica capillary, and the filled capillary is introduced into the middle of a chamber having a resonance frequency of 19 GHz. Then, an input signal source is applied, and the results of the output signal are recorded using a vector network analyzer. The changes in the resonance frequency and Q factor between the capillary filled with the liquid crystal and the blank capillary are measured, and the dielectric constant and loss tangent value are calculated. The dielectric constant components perpendicular and parallel to the liquid crystal director are obtained by the alignment of the liquid crystal in a magnetic field. The direction of the magnetic field is set accordingly, and then rotated by 90° accordingly.

[0060] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0061] In the following embodiments, the physical and optoelectronic properties of the mixed liquid crystal are tested. The detailed test methods for the physical and optoelectronic properties related to the present invention are as follows:

[0062] (1) Clearing point (Tni):

[0063] Polarized light hot stage method: Coat the liquid crystal sample on a glass slide and place it in an orthogonal polarized light microscope hot stage. Set the heating rate to 2 °C / min. Observe the temperature at which the liquid crystal sample starts to turn black from the bright state in the polarized light microscope, which is the clearing point.

[0064] Or use differential scanning calorimetry: Under a nitrogen atmosphere, set the heating rate to 2 °C / min.

[0065] (2) Low-temperature storage temperature (LTS): Fill about 1 mL of the mixed liquid crystal into a transparent glass bottle and place it in a low-temperature refrigerator. Set the temperatures to -20 °C, -30 °C, and -40 °C, and store for 120 h, 500 h, and 1000 h respectively. Observe whether there is crystal precipitation or smectic phase. If there is no crystal precipitation at -30 °C, LTS ≤ -30 °C.

[0066] (3) Birefringence (Δn): Using an Abbe refractometer, under the constant temperature condition of 25 °C and a light source of 589 nm, measure the refractive indices of the ordinary light (n o ) and the extraordinary light (n e ) respectively. The birefringence Δn = n e - n o .

[0067] (4) Dielectric constant (Δε): Under the constant temperature condition of 25 °C, measure using an LCR meter. Δε = ε ∥ - ε ⊥ , that is, the difference between the dielectric constant in the direction of the long axis of the molecule (ε ∥ ) and the dielectric constant in the direction of the short axis of the molecule (ε ⊥ ).

[0068] (5) Elastic constants (K 11 , K 33 ) and threshold voltage (V th ): Under the constant temperature condition of 25 °C, by testing the liquid crystal capacitance-voltage (C-V) curve and fitting, obtain K 11 and K 33 and V th .

[0069] (6) Rotational viscosity (γ1): Under the constant temperature condition of 25 °C, apply a voltage to the liquid crystal test cell, measure the transient current value Ip of the deflection of the liquid crystal molecules moving with the electric field, and calculate the rotational viscosity γ1.

[0070] For the relevant explanations of the codes involved in this article, see Tables 1-3 below:

[0071] Table 1 Physical parameters

[0072] Code Description Unit <![CDATA[T ni > Clearing point ℃ LTS Low temperature storage temperature ℃ <![CDATA[ε ⊥ > Dielectric constant perpendicular to the director <![CDATA[ε ∥ > Dielectric constant parallel to the director Δε Dielectric anisotropy <![CDATA[tanδ ⊥ > Dielectric loss tangent perpendicular to the director <![CDATA[tanδ ∥ > Dielectric loss tangent parallel to the director Δn Birefringence <![CDATA[γ1]]> Rotational viscosity mPa·s <![CDATA[K 11 > Splay elastic constant pN <![CDATA[K 33 > Bend elastic constant pN τ Dielectric tuning rate η Quality factor <![CDATA[V th > Threshold voltage v

[0073] Table 2 Abbreviations of the structural units in this article

[0074]

[0075]

[0076] Table 3 Examples of structural abbreviations

[0077]

[0078] Example 1:

[0079] Table 4 Composition and properties of Example 1

[0080]

[0081]

[0082] The liquid crystal composition of Example 1 has a large dielectric tuning rate, low dielectric loss, low rotational viscosity, large elastic constant, and low threshold voltage. The liquid crystal composition of Example 1 has a low rotational viscosity / elastic constant ratio (γ1 / K 11 ), and has a favorable response speed.

[0083] Example 2:

[0084] Table 5 Composition and properties of Example 2

[0085]

[0086]

[0087] Testing the performance of Example 2 found that it has a wide liquid crystal phase temperature range, and at the same time has a large dielectric tuning rate, low dielectric loss, extremely low rotational viscosity, large elastic constant, and low threshold voltage. The liquid crystal composition of Example 2 has an extremely low rotational viscosity / elastic constant ratio (γ1 / K 11 ), and has a very favorable response speed.

[0088] Example 3:

[0089] Table 6 Composition and properties of Example 3

[0090]

[0091] In Example 3, the test performance shows that it not only has a relatively wide liquid crystal phase temperature range, but also has a large dielectric tuning rate, low dielectric loss, low rotational viscosity, large elastic constant, and low threshold voltage. The liquid crystal composition of Example 3 has an extremely low rotational viscosity / elastic constant ratio (γ1 / K 11 ), and has a favorable response speed.

[0092] Example 4

[0093] Table 7 Composition and properties of Example 4

[0094]

[0095] In Example 4, the test performance shows that it not only has a relatively wide liquid crystal phase temperature range, but also has a large dielectric tuning rate, low dielectric loss, low rotational viscosity, large elastic constant, and low threshold voltage. The liquid crystal composition of Example 3 has a low rotational viscosity / elastic constant ratio (γ1 / K 11 ), and has a favorable response speed.

[0096] Comparative Example 1:

[0097] US2019292458A1 discloses a liquid crystal composition for high-frequency components, and its components are selected from 2,6-difluoro-substituted isothiocyanato liquid crystal compounds. In its Example N4, the following composition and performance parameters in Table 8 are disclosed:

[0098] Table 8

[0099]

[0100]

[0101] The liquid crystal components in Comparative Example 1 completely adopt 2,6-difluoro-substituted isothiocyanato liquid crystal compounds. Compared with Comparative Example 1, the dielectric loss in Example 2 of the present invention is comparable, but the rotational viscosity is greatly reduced; the elastic constant K 11 increases, and the rotational viscosity / elastic constant (γ1 / K 11 ) is also greatly reduced.

Claims

1. A liquid crystal composition having low viscosity, a wide operating temperature range, and a low threshold voltage, characterized in that, The liquid crystal composition contains one or more compounds selected from those represented by Structural General Formula I and one or more compounds selected from those represented by Structural General Formula II; In Formula I: R is an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyloxy group having 2 to 10 carbon atoms or an alkenyloxy group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom; Z1 is a single bond, -C≡C-, -CH=CH-, -CF=CF- or -CH2CH2, Z2 is a single bond, -C≡C-, -CH=CH-, -CF=CF- or -CH2CH2, and at least one of Z1 and Z2 is -C≡C-; Ring A is a benzene ring, cyclohexane, cyclohexene or a benzene ring in which hydrogen is substituted by fluorine, chlorine, methyl or / and ethyl; Ring B is a benzene ring or a benzene ring in which hydrogen is substituted by fluorine, chlorine, methyl or / and ethyl; n = 0 or 1; In Formula II: R1 and R2 are each independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms.

2. The liquid crystal composition according to claim 1, wherein Contains one or more compounds selected from those represented by Structural General Formulas I-1 to I-5:

3. The liquid crystal composition according to claim 1, wherein Contains one or more compounds selected from those represented by Structural General Formulas II-1 to II-2: R3 in II-1 to II-2 are each independently n-propyl, n-butyl or n-pentyl.

4. The liquid crystal composition according to claim 1, wherein The mass percentage of the compound represented by the general formula I is 70% to 95%; the mass percentage of the compound represented by the general formula II is 5% to 30%.

5. The liquid crystal composition according to claim 1, wherein Contains one or more compounds selected from those represented by Structural General Formulas III-1 to III-2: R4 in III-1 to III-2 are each independently an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkoxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyl group having 2 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom, an alkenyloxy group having 2 to 10 carbon atoms or an alkenyloxy group having 2 to 10 carbon atoms in which a hydrogen atom is substituted by a fluorine atom.

6. The liquid crystal composition according to claim 5, characterized in that, The mass percentage of the compound represented by the general formulas III-1 to III-2 is 0 to 30%.

7. The liquid crystal composition according to any one of claims 1 to 6, characterized in that, The high-frequency 19 GHz perpendicular dielectric loss value tanδ of the liquid crystal composition ⊥ ≤0.015, the quality factor η ≥ 20; the rotational viscosity of the liquid crystal composition ≤ 350 mPa·s; the dielectric anisotropy Δε at low frequency 1 KHz > 12, the threshold voltage < 1.3 V; the nematic phase temperature range is -20 to 100 °C or higher.

8. The liquid crystal composition according to any one of claims 1 to 6, characterized in that, The tuning rate τ of the liquid crystal composition is ≥ 0.

26.

9. The liquid crystal composition according to any one of claims 1 to 6, characterized in that, The splay elastic constant K of the liquid crystal composition 11 ≥ 15 pN, and γ1 / K of the liquid crystal composition 11 ≤ 20.

10. An optoelectronic display device, characterized in that, The optoelectronic display device is prepared using the liquid crystal composition according to any one of claims 1-6.

11. A high-frequency component, characterized in that, The high-frequency component is prepared using the liquid crystal composition according to any one of claims 1-6.

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