Liquid crystal composition and element thereof

Abstract

According to the liquid crystal composition, all components (general formulas I-IV) contain F atoms, and the limitation that only part of components of a traditional liquid crystal material contain F atoms is broken through. The problems of high transparent haze and slow low-temperature response of a negative dielectric liquid crystal material are effectively solved. A traditional fluorinated compound is easy to separate from a polycyclic structure due to non-uniform F distribution, so that the optical uniformity is poor, and low-temperature viscosity drastic increase and high-temperature molecule out-of-order are difficult to improve at the same time. Through all-component F-containing design, the dielectric anisotropy is reduced, and the negative dielectric property is endowed; meanwhile, a special space structure and uniform distribution of F atoms synergistically enhance the stability of an intermolecular interaction network, maintain a low-viscosity characteristic in a wide temperature range, inhibit abnormal rise of low-temperature viscosity so as to accelerate response and reduce delay, inhibit out-of-order arrangement of high-temperature molecules, remarkably reduce the decreasing amplitude of fog-state light transmittance and improve the fog-state light transmittance. And collaborative optimization of optical uniformity, response speed and high-temperature stability is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid crystal compositions, and particularly relates to a liquid crystal material and its use in an electro-controlled dimming device. Background Art

[0002] According to the similarities and differences in control means and principles, dimming devices can achieve switching between transparent and opaque states or between high light transmittance (transmissive state) and low light transmittance (dark state) through various methods such as electro-control, temperature-control, light-control, pressure-control, etc. Electro-controlled liquid crystal is the most widely used method for achieving dimming in current market dimming devices. There are two dimming forms for electro-controlled liquid crystal dimming devices. One is to use a liquid crystal material with positive dielectric anisotropy. After applying voltage, it is transparent to light, and after power-off, it is opaque to light. The other is to use a liquid crystal material with negative dielectric anisotropy. After applying voltage, it is opaque to light, and after power-off, it is transparent to light. These two dimming forms each have their suitable application scenarios.

[0003] For the dimming mode using a liquid crystal material with negative dielectric anisotropy, high transmittive haze, high driving voltage in the haze state, and low haze value in the haze state have always restricted the popularization and application of this dimming mode. Liquid crystal material is one of the key parts of a dimming device, and improving the performance of the dimming device through liquid crystal material is one of the most direct ways.

[0004] Existing negative dielectric liquid crystal materials have defects such as high transmittive haze and slow low-temperature response. Although traditional fluorinated compounds can improve temperature stability, they are prone to phase separation with polycyclic structures, resulting in a decrease in optical uniformity. In addition, existing materials are prone to a sharp increase in viscosity at low temperatures, leading to response delay, and the molecular arrangement becomes disordered at high temperatures, resulting in a significant decrease in haze transmittance. Summary of the Invention

[0005] The purpose of the present invention is to provide a liquid crystal composition, which is suitable for an electro-controlled dimming device that switches between a transmissive state and a haze state, and has the characteristics of low transmittive haze, low driving voltage in the haze state, and high haze value in the haze state.

[0006] To achieve the above purpose, in a first aspect, the present invention provides a liquid crystal composition, comprising: Component One, selected from at least one of the compounds represented by General Formula I, wherein in the structural formula, R1 and R2 are each independently selected from C1-C6 alkyl groups, and Z1 is selected from a carbon-carbon single bond or a carbon-carbon triple bond; Component Two, selected from at least one of the compounds represented by General Formula II, wherein in the structural formula, R3 and R4 are each independently selected from C1-C6 alkyl groups, and Z2 is selected from a carbon-carbon single bond or a carbon-carbon triple bond; Component Three, selected from at least one of the compounds represented by General Formula III, wherein in the structural formula, R5 is selected from C1-C6 alkyl groups; Component Four, selected from at least one of the compounds represented by General Formula Ⅳ, wherein m and n in the structural formula are each independently selected from the integers 1, 2, 3, 4, 5; wherein, based on the total weight of the liquid crystal composition, the content of Component One is 5% - 35%, the content of Component Two is 5% - 30%, the content of Component Three is 1% - 25%, and the content of Component Four is 1% - 20%; and each general formula compound can be used alone or in combination; The general formulas are as follows: I Ⅱ Ⅲ Ⅳ.

[0007] In some preferred embodiments of the present invention, the liquid crystal composition contains a benzene ring, and each of two carbon atoms of the benzene ring is substituted with an F atom, and the benzene ring is connected to an alicyclic group or an aromatic ring group through a linking group selected from a carbon-carbon single bond or a carbon-carbon triple bond.

[0008] In some preferred embodiments of the present invention, the ratio of the number of F atoms to the number of aromatic ring groups and alicyclic groups is 1:1 - 5.

[0009] In some preferred embodiments of the present invention, Component One includes the compounds represented by Formula I-5, Formula I-6, Formula I-7, and Formula I-8, and at least one selected from the group consisting of the compounds represented by Formula I-1, Formula I-2, Formula I-3, and Formula I-4; Component Two includes the compounds represented by Formula II-5, Formula II-6, Formula II-7, and Formula II-8, and at least one selected from the group consisting of the compounds represented by Formula II-1, Formula II-2, Formula II-3, and Formula II-4; Component Three includes the compounds represented by Formula III-1 and Formula III-2, and at least one selected from the group consisting of the compounds represented by Formula III-3 and Formula III-4; In Component Four, the sum of m and n satisfies the relationship 3 ≤ m + n ≤ 6; Wherein, the general formulas are as follows: I-1 I-2 I-3 I-4 I-5 I-6 I-7 I-8 Ⅱ-1 Ⅱ-2 Ⅱ-3 Ⅱ-4 Ⅱ-5 Ⅱ-6 Ⅱ-7 Ⅱ-8 Ⅲ-1 Ⅲ-2 Ⅲ-3 Ⅲ-4。

[0010] In some preferred embodiments of the present invention, the liquid crystal composition further comprises Component Five, which is at least one selected from the group consisting of compounds represented by General Formulas V-1, V-2, and V-3; wherein, in General Formulas V-1, V-2, and V-3: Ra, Rc, and Re are each independently selected from C2-C6 alkyl groups; Rb, Rd, and Rf are each independently selected from C1-C5 alkyl groups or C1-C5 alkoxy groups; P is selected from 0 or 1; The general formulas are as follows: V-1 V-2 V-3。

[0011] In some preferred embodiments of the present invention, the liquid crystal composition further comprises Component Six, which is at least one selected from the group consisting of compounds represented by General Formulas VI-1, General Formula VI-2, and General Formula VI-3 wherein, in General Formulas VI-1, VI-2, and VI-3: Rg, Rh, and Rj are each independently selected from C2-C5 alkyl groups; Rk is selected from at least one of methyl, ethyl, methoxy, or ethoxy; The general formulas are as follows: VI-1 VI-2 VI-3。

[0012] In some preferred embodiments of the present invention, based on the total weight of the liquid crystal composition, the total content of the compound represented by the general formula I is 10% - 30%; the total content of the compound represented by the general formula II is 10% - 28%; the total content of the compound represented by the general formula III is 3% - 15%; the total content of the compound represented by the general formula IV in the liquid crystal material is 5% - 15%; the total content of the compounds represented by the general formulas V-1, V-2, and V-3 is 0% - 15%; the total content of the compounds represented by the general formulas VI-1, VI-2, and VI-3 is 0% - 15%.

[0013] In some preferred embodiments of the present invention, the transition temperature from the liquid crystal phase to the isotropic phase of the liquid crystal composition is ≥ 90 °C.

[0014] In a second aspect, the present invention also provides a component, which comprises the liquid crystal composition described in the first aspect.

[0015] In some preferred embodiments of the present invention, the component is an electro - controlled dimming device.

[0016] The dimming device is particularly suitable for applications in electronic curtains and automotive dimming windows.

[0017] Beneficial effects: Through research, it is found in the present invention that fluorine atoms, as the elements with the strongest electronegativity, their strong electron - binding effect makes the C - F bond present a unique electron - cloud distribution characteristic - this covalent bond has a relatively high degree of electron - cloud localization and exhibits excellent stability against external environmental perturbations. Based on this molecular characteristic, the intermolecular interactions in the polyfluorinated compound system are significantly weaker than those in conventional organic compounds. Particularly importantly, under extreme temperature conditions, this weak intermolecular force characteristic can effectively inhibit the fluctuations of intermolecular forces caused by temperature fluctuations, so that material properties (such as key parameters like dielectric constant and viscosity coefficient) can maintain excellent stability within a wide temperature range. This characteristic has important value for the development of materials adaptable to extreme environments.

[0018] Polyfluorinated compounds, with their unique "fluorocarbon phase" micro - region structure and intermolecular dynamic voids of 0.5 - 1.2 nm, provide a new idea for regulating the wide - temperature - range stability of the liquid crystal system. However, the content of polyfluorinated compounds and their high - and low - temperature stability do not show a linear relationship. Therefore, it is necessary to further study the types of polyfluorinated compounds, the types of components of the liquid crystal composition, and their feasible ratios. Based on this, the present invention is further proposed.

[0019] The present invention innovatively combines four groups of polyfluorinated compounds containing fluorine atoms in a specific ratio to achieve multi-dimensional synergistic effects. The fluorinated flexible chain of component four and the rigid conjugated core of component one form a superposition of polar gradients, reducing the fog-state driving voltage; the multi-aromatic ring structure of component two and the fluorine chain of component four are regulated by steric hindrance, and fluorinated spacers with specific chain lengths are inserted into the gaps between polybenzene rings to inhibit excessive thermal motion of molecules at high temperatures and avoid rigid overload at low temperatures, achieving haze stability in a wide temperature range; the oxygen-bridged structure of component three and the fluorine chain of component four enhance the low-temperature fluidity through an intramolecular hydrogen bond network; the medium fluorine chain length of component four and the polycyclic rigid skeletons of components one and two construct a three-dimensional supramolecular network, improving the optical stability of the liquid crystal material. At the same time, the branched alkyl group of component three and the steric hindrance effect of component four reduce the haze in the light-transmitting state, thus comprehensively breaking through the technical bottlenecks of low-voltage driving, wide-temperature-range stability, and high environmental tolerance. Different from traditional liquid crystal materials in which only some components contain fluorine atoms, all components (general formulas I-IV) of the present invention contain fluorine atoms. The uniformly distributed fluorine atoms reduce the dielectric anisotropy of the liquid crystal material, endowing it with excellent negative dielectric properties. Moreover, the strong electronegativity and special spatial structure of fluorine atoms act synergistically to greatly improve the stability of the material in a wide temperature range, effectively inhibiting the abnormal increase in viscosity at low temperatures, accelerating the response speed, reducing the response delay phenomenon, maintaining a good molecular arrangement order even in a high-temperature environment, and significantly reducing the reduction amplitude of the fog-state light transmittance, successfully solving a series of defects such as high fog in the light-transmitting state and slow low-temperature response of existing negative dielectric liquid crystal materials.

[0020] Furthermore, the ratio of the F atoms to the aromatic ring groups and the alicyclic groups is 1:(1-5). By precisely controlling the ratio of the F atoms to the aromatic ring groups and the alicyclic groups, a precise balance between the polarity and rigidity of the liquid crystal molecules is achieved. This ratio ensures that a suitable density of fluorine atoms is distributed around each aromatic ring and alicyclic group, which not only significantly reduces the intermolecular forces by utilizing the strong electronegativity of fluorine atoms, effectively reduces the dielectric anisotropy, and gives the material negative dielectric properties, but also avoids excessive aggregation of F atoms resulting in too weak intermolecular forces, thereby maintaining the orderly arrangement of molecules in a high temperature environment and preventing dielectric performance failure and optical uniformity from decreasing. At the same time, this ratio makes the fluorine atoms evenly distributed on the surface of the polycyclic skeleton rather than locally aggregated, thus constructing a reasonable polarity. The gradient superposition effect not only enhances the intermolecular interaction to reduce the mist driving voltage, but also fundamentally avoids the phase separation risk caused by the local enrichment of F atoms in traditional fluorinated compounds, ensuring stable optical performance over a wide temperature range. In addition, this ratio range gives the molecules moderate polarity (derived from the reasonably distributed F atoms) and rigidity (derived from the aromatic rings and alicyclic skeletons that are not over-substituted), effectively suppressing the abnormal increase in viscosity under low temperature conditions (keeping the molecular motion resistance moderate) and accelerating the response speed, while maintaining the order of molecular arrangement under high temperature conditions (limiting excessive thermal motion through appropriate fluorine atom distribution density), reducing the decrease in transmittance, and ultimately achieving the coordinated optimization of reduced driving voltage, improved response speed and stable optical performance over a wide temperature range. DETAILED DESCRIPTION

[0021] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, the endpoint values of each range and the individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article. Among them, the terms "optional" and "optional" all mean that they may be included or not included (or may be present or not).

[0022] The general formulae mentioned in the specific embodiments of the present invention are the same as the corresponding general formulae in the aforementioned summary of the invention.

[0023] The present invention provides a liquid crystal composition, comprising: component 1, component 2, component 3 and component 4. Wherein, based on the total weight of the liquid crystal composition, the content of component 1 is 5%-35%, the content of component 2 is 5%-30%, the content of component 3 is 1%-25%, and the content of component 4 is 1%-20%.

[0024] In some preferred embodiments of the present invention, the ratio of the number of F atoms to the number of aromatic ring groups and alicyclic ring groups is 1:1 - 5, preferably 1:1.5 - 3.5. By precisely controlling the ratio of the number of F atoms to the number of aromatic ring groups and alicyclic ring groups, an accurate balance between the polarity and rigidity of liquid crystal molecules is achieved. This ratio ensures an appropriate density of fluorine atoms around each aromatic ring and alicyclic ring group, which not only significantly reduces the intermolecular force by the strong electronegativity of fluorine atoms, effectively reduces the dielectric anisotropy, and endows the material with negative dielectric properties, but also avoids the excessive aggregation of F atoms leading to too weak intermolecular force, thus maintaining the ordered arrangement of molecules in a high-temperature environment and preventing the failure of dielectric properties and the decline of optical uniformity. At the same time, this ratio makes the fluorine atoms evenly distributed on the surface of the polycyclic skeleton rather than in a locally aggregated state, constructing a reasonable superposition effect of polarity gradient, which not only enhances the intermolecular interaction to reduce the driving voltage in the fog state, but also fundamentally avoids the phase separation risk caused by the local enrichment of F atoms in traditional fluorinated compounds, ensuring stable optical properties within a wide temperature range. In addition, this ratio range endows the molecule with moderate polarity (derived from the reasonably distributed F atoms) and rigidity (derived from the non-over-substituted aromatic ring and alicyclic ring skeletons), effectively suppressing the abnormal increase in viscosity (maintaining moderate molecular motion resistance) and accelerating the response speed at low temperatures, while maintaining the ordered arrangement of molecules (limiting excessive thermal motion through the appropriate distribution density of fluorine atoms) and reducing the decrease in light transmittance at high temperatures, ultimately achieving the synergistic optimization of reduced driving voltage, improved response speed, and stable optical properties within a wide temperature range.

[0025] In some preferred embodiments of the present invention, the transition temperature from the liquid crystal phase to the isotropic phase of the liquid crystal material is ≥90 °C, preferably ≥95 °C, and further preferably ≥100 °C, which is more conducive to the stability of the liquid crystal material in a high-temperature environment.

[0026] Component 1 of the present invention is selected from the compounds represented by General Formula I, including the compounds represented by Formula I-5, Formula I-6, Formula I-7, and Formula I-8, and at least one selected from the group consisting of the compounds represented by Formula I-1, Formula I-2, Formula I-3, and Formula I-4. Wherein R1 and R2 are each independently selected from C1-C6 alkyl groups, and Z1 is selected from a carbon-carbon single bond or a carbon-carbon triple bond. The number of carbon atoms in R1 and R2 is 1-6, and the alkyl group can be straight-chain or branched-chain. For example, when the number of carbon atoms is 4, R1 and R2 can represent n-butyl, isobutyl, sec-butyl, or tert-butyl.

[0027] I.

[0028] In the present invention, the abbreviation codes corresponding to some structural formulas are shown in Table 1 below.

[0029] Table 1

[0030] Exemplarily, Component 1 can be selected from at least one of C2H5-Ph-Ph(2F3F)-OC2H5, C3H7-Ph-Ph(2F3F)-OC2H5, C4H9-Ph-Ph(2F3F)-OC2H5, C5H 11 -Ph-Ph(2F3F)-OC2H5, C2H5-Ph-CC-Ph(2F3F)-OC2H5, C3H7-Ph-CC-Ph(2F3F)-OC2H5, C4H9-Ph-CC-Ph(2F3F)-OC2H5, C5H 11 -Ph-CC-Ph(2F3F)-OC2H5.

[0031] In some preferred embodiments of the present invention, Component 1 includes the compounds shown in Formula I-5, Formula I-6, Formula I-7, and Formula I-8, and at least one selected from the group consisting of the compounds shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4. Among them, the general formulas are as follows: I-1 I-2 I-3 I-4 I-5 I-6 I-7 I-8.

[0032] Preferably, based on the total weight of the liquid crystal composition, the sum of the contents of the compounds shown in Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7, and Formula I-8 is 10% - 30%. Under this preferred scheme, the ratio is appropriate. Through the dynamic ratio balance of the rigid conjugate skeleton and the flexible structure, the molecular orientation order and the electric field response sensitivity are significantly improved. This ratio enables the liquid crystal material to exhibit a higher refractive index difference and dielectric anisotropy between the light-transmitting state and the fog state, thereby reducing the driving energy consumption and ensuring the stability of the molecular arrangement in a wide temperature range.

[0033] More preferably, based on the total weight of the liquid crystal composition, the content of the compound shown in Formula I-1 is 0 - 5%, the content of the compound shown in Formula I-2 is 0 - 5%, the content of the compound shown in Formula I-3 is 0 - 5%, the content of the compound shown in Formula I-4 is 0 - 5%, the content of the compound shown in Formula I-5 is 0 - 10%, the content of the compound shown in Formula I-6 is 0 - 10%, the content of the compound shown in Formula I-7 is 0 - 10%, and the content of the compound shown in Formula I-8 is 0 - 10%.

[0034] Further preferably, based on the total weight of the liquid crystal composition, the content of the compound represented by Formula I-1 is 1-3%, the content of the compound represented by Formula I-2 is 1-3%, the content of the compound represented by Formula I-3 is 2-3%, the content of the compound represented by Formula I-4 is 2-3%, the content of the compound represented by Formula I-5 is 2-6%, the content of the compound represented by Formula I-6 is 2-6%, the content of the compound represented by Formula I-7 is 2-6%, and the content of the compound represented by Formula I-8 is 2-6%. Under this preferred scheme, the proportions of the compounds are appropriate, which is more conducive to the rigid-flexible balance of the liquid crystal system and improves the electric field driving efficiency and the stability of the transmission / fog state switching.

[0035] Component two of the present invention is selected from the compounds represented by General Formula II, including the compounds represented by Formula II-5, Formula II-6, Formula II-7 and Formula II-8, and at least one selected from the group consisting of the compounds represented by Formula II-1, Formula II-2, Formula II-3 and Formula II-4. Wherein R3 and R4 are each independently selected from C1-C6 alkyl groups, and Z2 is selected from a carbon-carbon single bond or a carbon-carbon triple bond. The number of carbon atoms in R3 and R4 is 1-6, and the alkyl group can be straight-chain or branched-chain. For example, when the number of carbon atoms is 4, R3 and R4 can represent n-butyl, isobutyl, sec-butyl or tert-butyl. Among them, the general formula is as follows: Ⅱ Exemplarily, component two can be selected from at least one of C2H5-Ch-Ph-Ph(2F3F)-OC2H5, C3H7-Ch-Ph-Ph(2F3F)-OC2H5, C4H9-Ch-Ph-Ph(2F3F)-OC2H5, C5H 11 -Ch-Ph-Ph(2F3F)-OC2H5, C2H5-Ch-Ph-CC-Ph(2F3F)-OC2H5, C3H7-Ch-Ph-CC-Ph(2F3F)-OC2H5, C4H9-Ch-Ph-CC-Ph(2F3F)-OC2H5, C5H 11 -Ch-Ph-CC-Ph(2F3F)-OC2H.

[0036] In some preferred embodiments of the present invention, component two includes the compounds represented by Formula II-5, Formula II-6, Formula II-7 and Formula II-8, and at least one selected from the group consisting of the compounds represented by Formula II-1, Formula II-2, Formula II-3 and Formula II-4. Among them, the general formula is as follows: Ⅱ-1 Ⅱ-2 Ⅱ-3 Ⅱ-4 Ⅱ-5 Ⅱ-6 Ⅱ-7 Ⅱ-8 Preferably, based on the total weight of the liquid crystal composition, the sum of the contents of the compounds represented by Formula Ⅱ-1, Formula Ⅱ-2, Formula Ⅱ-3, Formula Ⅱ-4, Formula Ⅱ-5, Formula Ⅱ-6, Formula Ⅱ-7 and Formula Ⅱ-8 is 10%-28%. Under this preferred scheme, the ratio is appropriate, which is beneficial to balancing the liquid crystal system and improving the stability.

[0037] More preferably, based on the total weight of the liquid crystal composition, the content of the compound represented by Formula Ⅱ-1 is 0-5%, the content of the compound represented by Formula Ⅱ-2 is 0-5%, the content of the compound represented by Formula Ⅱ-3 is 0-5%, the content of the compound represented by Formula Ⅱ-4 is 0-5%, the content of the compound represented by Formula Ⅱ-5 is 0-10%, the content of the compound represented by Formula Ⅱ-6 is 0-10%, the content of the compound represented by Formula Ⅱ-7 is 0-10%, and the content of the compound represented by Formula Ⅱ-8 is 0-10%.

[0038] Further preferably, based on the total weight of the liquid crystal composition, the content of the compound represented by Formula Ⅱ-1 is 1-2%, the content of the compound represented by Formula Ⅱ-2 is 1-2%, the content of the compound represented by Formula Ⅱ-3 is 1-2%, the content of the compound represented by Formula I-4 is Ⅱ-2%, the content of the compound represented by Formula Ⅱ-5 is 4-7%, the content of the compound represented by Formula Ⅱ-6 is 4-7%, the content of the compound represented by Formula Ⅱ-7 is 4-7%, and the content of the compound represented by Formula Ⅱ-8 is 4-7%. Under this preferred scheme, the proportions of the compounds are appropriate. By extending the flexible chain, it is more conducive to the multi-scale synergistic effect of the liquid crystal system and the optimization of the wide-temperature stability.

[0039] Component three of the present invention is selected from the compounds represented by General Formula Ⅲ, including the compounds represented by Formula Ⅲ-1 and Formula Ⅲ-2, and at least one selected from the group consisting of Formula Ⅲ-3 and Formula Ⅲ-4, wherein R5 is selected from C1-C6 alkyl. The number of carbon atoms in R5 is 1-6, and the alkyl can be straight-chain or branched-chain. For example, when the number of carbon atoms is 4, R5 can represent n-butyl, isobutyl, sec-butyl or tert-butyl. Among them, the general formula is as follows: Ⅲ Exemplarily, Component three can be selected from C2H5-Ch-Ch-CH2O-Ph(2F3F)-OC2H5, C3H7-Ch-Ch-CH2O-Ph(2F3F)-OC2H5, C4H9-Ch-Ch-CH2O-Ph(2F3F)-OC2H5, C5H 11At least one of -Ch-Ch-CH2O-Ph(2F3F)-OC2H5, etc.

[0040] In some preferred embodiments of the present invention, the component three includes the compounds shown in Formula III-1 and Formula III-2, and at least one selected from the group consisting of Formula III-3 and Formula III-4. Among them, the general formulas are as follows: Ⅲ-1 Ⅲ-2 Ⅲ-3 Ⅲ-4 Preferably, based on the total weight of the liquid crystal composition, the sum of the contents of the compounds shown in Formula III-1, Formula III-2, Formula III-3, and Formula III-4 is 3% - 15%. Under this preferred scheme, the ratio is appropriate, which is beneficial to balancing the liquid crystal system and improving stability.

[0041] More preferably, based on the total weight of the liquid crystal composition, the content of the compound shown in Formula III-1 is 0 - 5%, the content of the compound shown in Formula III-2 is 0 - 5%, the content of the compound shown in Formula III-3 is 0 - 5%, and the content of the compound shown in Formula III-4 is 0 - 5%.

[0042] In some specific embodiments, based on the total weight of the liquid crystal composition, the content of the compound shown in III-1 is 1 - 3%, the content of the compound shown in Formula III-2 is 1 - 3%, the content of the compound shown in Formula III-3 is 2 - 3%, and the content of the compound shown in Formula III-4 is 2 - 3%. Under this preferred scheme, by introducing oxygen-containing groups, it is more conducive to improving the wide-temperature operation ability and fast-switching stability of the liquid crystal material.

[0043] The component four of the present invention is selected from at least one of the compounds shown in the general formula IV, where m and n in the structural formula are each independently selected from the integers 1, 2, 3, 4, 5. Among them, the general formula is as follows: Ⅳ.

[0044] Exemplarily, the component four can be selected from at least one of CF3CH2-Ph(2F3F)-CF2CF2-Ph(2F3F)-C2H4CF3, CF3CH2-Ph(2F3F)-CF2CF2-Ph(2F3F)-C3H6CF3, CF3CH2-Ph(2F3F)-CF2CF2-Ph(2F3F)-C4H8CF3, CF3C2H4-Ph(2F3F)-CF2CF2-Ph(2F3F)-C4H8CF3, etc.

[0045] More preferably, the component four comprises at least one of the compounds represented by the general formula Ⅳ, and the total content of the compounds represented by the general formula Ⅳ is 1%-15% based on the total weight of the liquid crystal composition. In this preferred embodiment, the liquid crystal composition contains a suitable proportion of the compounds represented by the general formula Ⅳ, which is more conducive to achieving fast response and wide-temperature stability through the polar gradient distribution and dynamic molecular conformation regulation of the perfluorocarbon chain.

[0046] Preferably in the present invention, the liquid crystal composition further comprises a component five, and the component five is selected from at least one of the compounds represented by the formula V-1, formula V-2, and formula V-3, wherein Ra, Rc, and Re are each independently selected from C2-C6 alkyl groups, Rb, Rd, and Rf are each independently selected from C1-C5 alkyl groups or C1-C5 alkoxy groups, and P in the formula is selected from 0 or 1. Among them, the number of alkyl carbon atoms of Ra, Rc, and Re can be the same or different, and can be a straight-chain alkyl group or a branched-chain alkyl group. When Rb, Rd, and Rf are alkyl groups, they can be straight-chain alkyl (oxyalkyl) groups or branched-chain alkyl (oxyalkyl) groups, and the number of their carbon atoms can also be the same or different. Among them, the general formulas are as follows: V-1 V-2 V-3.

[0047] Exemplarily, the component five can be selected from at least one of C3H7-Ph-Ph(2F3F)-Ph-C2H5, C4H9-Ph-Ph(2F3F)-Ph-C2H5, C3H7-Ph-Ph-Ph(2F3F)-C2H5, C4H9-Ph-Ph-Ph(2F3F)-C3H7, C3H7-Ch-Ph(2F3F)-OC2H5, C5H 11 -Ch-Ph(2F3F)-OC4H9, etc.

[0048] In the preferred embodiment of the present invention containing the component five, the component five cooperates with other components, and can synergistically optimize the dielectric anisotropy and the molecular orientation restoring force through the polar regulation of the alkoxy group, the dynamic spatial matching of the long-chain alkyl group, and the rigid-flexible balance effect of the multi-aromatic ring, thereby being more conducive to improving the response speed, light transmittance, and service life.

[0049] Preferably, the content of the component five in the liquid crystal composition is 0%-15%.

[0050] Preferably, the liquid crystal composition of the present invention further comprises Component VI. Component V is selected from at least one of the compounds represented by Formula VI-1, Formula VI-2, and Formula VI-3, wherein Rg, Rh, and Rj are each independently selected from C2-C5 alkyl groups, and Rk is optionally selected from methyl, ethyl, methoxy, or ethoxy. Among them, the number of alkyl carbon atoms of Rg, Rh, and Rj can be the same or different, and can be a straight-chain alkyl group or a branched-chain alkyl group. Among them, the respective general formulas are as follows: VI-1 VI-2 VI-3.

[0051] Exemplarily, Component VI can be selected from at least one of C2H5-Ph(3F5F)-CC-Ph-Ph-C3H7, C4H9-Ph(3F5F)-CC-Ph-Ph-C3H7, C3H7-Ph-CC-Ph-CH 35 , C4H9-Ph-CC-Ph-OCH3, C3H7-Ch-Ph-Ph-Ch-C3H7, etc.

[0052] In the preferred embodiment of the present invention containing Component VI, Component VI cooperates with other components, and can synergistically optimize the dielectric anisotropy and the molecular orientation restoring force through the dynamic conformational adaptation of the alkyl group and the polar synergistic effect of the methoxy / ethoxy group, thereby being more conducive to improving the molecular orientation uniformity of the liquid crystal material and the optical stability at extreme temperatures.

[0053] Preferably, the content of Component VI in the liquid crystal composition is 0%-15%.

[0054] The liquid crystal composition of the present invention can simultaneously achieve the comprehensive effects of fast response speed and good high and low temperature tolerance.

[0055] The present invention also provides a device, which comprises the above-mentioned liquid crystal composition.

[0056] In some preferred embodiments of the present invention, the device is a dimming device, and further an electro-controlled dimming device. The liquid crystal composition of the present invention can be used in any electro-controlled dimming device in the prior art.

[0057] The dimming device can include, for example, at least one of an in-vehicle dynamic sunshade system (sunroof, side window, and rear windshield dimming modules), a building intelligent window (electronic curtain, curtain wall dimming unit), a high-resolution display device, etc. The dimming device can be applied to extreme environments, and is particularly suitable for automotive dimming windows that are often used in extremely cold and extremely hot scenarios.

[0058] Examples of the present invention will be described in detail below. These examples are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0059] The compositions and their contents of the liquid crystal compositions of Examples 1 - 6 are shown in Table 2. Among them, unless otherwise specified or stated to the contrary, the alkyl group refers to a straight-chain alkyl group.

[0060] Table 2 (where the content is the percentage by weight of the total weight of the liquid crystal composition)

[0061] The liquid crystal compositions of the above examples were respectively subjected to various performance tests, and the test results are shown in Table 3. The test methods are as follows: The transition temperature from the liquid crystal phase state to the isotropic phase state of the liquid crystal composition is represented by TnI, and the test instrument is a melting point instrument.

[0062] The refractive index anisotropy of the liquid crystal composition is represented by Δn, and the test instrument is an Abbe refractometer, and the test wavelength is the corresponding light source wavelength. The transition temperature from the liquid crystal phase to the solid state of the liquid crystal composition is represented by Tcn, and the test method: place the liquid crystal in a refrigerator at a certain temperature. After 24 hours, if it is still in the liquid crystal phase state, it means that Tcn is less than this temperature.

[0063] Measurement of the haze value of the liquid crystal composition from the liquid crystal phase to the solid state: Mix the liquid crystal composition, RM82 (trade name), and photoinitiator 184 (trade name) evenly at a ratio of 94.7:5:0.3. Then fill the mixed liquid crystal mixture between two ITO and PET films containing a vertically aligned PI film (for the preparation reference of the vertically aligned PI film, refer to Chinese Patent ZL201410477879.9). Control the thickness of the liquid crystal mixture to be 8 um through spacers. Under the condition of 25 °C, irradiate with UV light with an intensity of 5 W / cm², and then measure the haze value (denoted as H 15 ) at 15 V voltage and the haze value (denoted as H0) in the non-powered state. The haze value measurement instrument model is RhopoInt TX.

[0064] Table 3 Performance test results of the liquid crystal composition (Examples 1 - 6)

[0065] Example 7 It is carried out with reference to Example 1, except that the compound shown in Formula I-5 is not contained in Component 1. Meanwhile, the mass ratios of the compounds shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula I-5. The total content of Component 1 is kept at 30%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0066] Example 8 It is carried out with reference to Example 1, except that the compound shown in Formula I-6 is not contained in Component 1. Meanwhile, the mass ratios of the compounds shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula I-6. The total content of Component 1 is kept at 30%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0067] Example 9 It is carried out with reference to Example 1, except that the compound shown in Formula I-7 is not contained in Component 1. Meanwhile, the mass ratios of the compounds shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula I-7. The total content of Component 1 is kept at 30%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0068] Example 10 It is carried out with reference to Example 1, except that the compounds shown in Formula I-5, I-6, I-7, and I-8 are not contained in Component 1. Meanwhile, the mass ratios of the compounds shown in Formula I-1, Formula I-2, Formula I-3, and Formula I-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the contents of the compounds shown in Formula I-5, I-6, I-7, and I-8. The total content of Component 1 is kept at 30%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0069] Example 11 It is carried out with reference to Example 1, except that in Component 1, -C3H7, -C4H9, -C5H 11 in the compounds shown in Formula I-6, Formula I-7, and Formula I-8 are non-branched alkyl groups, specifically isopropyl, isobutyl, and isopentyl respectively.

[0070] Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0071] Example 12 It is carried out with reference to Example 1, except that the compound shown in Formula II-5 is not contained in Component II. Meanwhile, the mass ratios of the compounds shown in Formula II-1, Formula II-2, Formula II-3, and Formula II-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula II-5. The total content of Component II is kept at 28%.

[0072] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0073] Example 13 It is carried out with reference to Example 1, except that the compound shown in Formula II-6 is not contained in Component II. Meanwhile, the mass ratios of the compounds shown in Formula II-1, Formula II-2, Formula II-3, and Formula II-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula II-6. The total content of Component II is kept at 28%. And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0074] Example 14 It is carried out with reference to Example 1, except that the compound shown in Formula II-7 is not contained in Component II. Meanwhile, the mass ratios of the compounds shown in Formula II-1, Formula II-2, Formula II-3, and Formula II-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the content of the compound shown in Formula II-7. The total content of Component II is kept at 28%. And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0075] Example 15 It is carried out with reference to Example 1, except that the compounds shown in Formula II-5, II-6, II-7, and II-8 are not contained in Component II. Meanwhile, the mass ratios of the compounds shown in Formula II-1, Formula II-2, Formula II-3, and Formula II-4 are kept the same as those in Example 1, and the contents of the four compounds are adjusted proportionally to make up for the contents of the compounds shown in Formula II-5, II-6, II-7, and II-8. The total content of Component II is kept at 28%. And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0076] Example 16 It is carried out with reference to Example 1, except that the compound shown in III-1 is not contained in Component III. Meanwhile, the mass ratios of the compounds shown in Formula III-3 and Formula III-4 are kept the same as those in Example 1, and the contents of the two compounds are adjusted proportionally to make up for the content of the compound shown in III-1. The total content of Component III is kept at 8%. And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0077] Example 17 It is carried out with reference to Example 1, except that the compound shown in Ⅲ-2 is not contained in Component 3. At the same time, the mass ratio of the compounds shown in Formula Ⅲ-3 and Formula Ⅲ-4 is kept the same as that in Example 1, and the contents of the two compounds are adjusted proportionally to make up for the content of the compound shown in Ⅲ-2. The total content of Component 3 is kept at 8%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0078] Example 18 It is carried out with reference to Example 1, except that the compounds shown in Ⅲ-1 and Ⅲ-2 are not contained in Component 3. At the same time, the mass ratio of the compounds shown in Formula Ⅲ-3 and Formula Ⅲ-4 is kept the same as that in Example 1, and the contents of the two compounds are adjusted proportionally to make up for the contents of the compounds shown in Ⅲ-1 and Ⅲ-2. The total content of Component 3 is kept at 8%. Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0079] Example 19 It is carried out with reference to Example 1, except that in Component 4, -C3H6 and -C4H8 in the compound shown in the general formula Ⅳ are non-branched alkyl groups, specifically isopropyl group and isobutyl group respectively.

[0080] Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0081] Example 20 It is carried out with reference to Example 1, except that in Component 5, the substituents of the compound shown in Formula V-1 are different, specifically C3H7-Ph-Ph(2F3F)-Ph-OC2H5, and the content remains unchanged.

[0082] Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0083] Example 21 It is carried out with reference to Example 1, except that in Component 5, the positions of the F atoms in the compound shown in Formula V-1 are different, specifically C3H7-Ph(2F3F)-Ph-Ph-C2H5, and the content remains unchanged.

[0084] Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0085] Example 22 It is carried out with reference to Example 1, except that in Component 6, -C3H7 in the compound shown in Formula Ⅳ-1 is a branched alkyl group, specifically isopropyl group.

[0086] Corresponding performance tests are carried out, and the test results are shown in Table 4.

[0087] Example 23 It is carried out with reference to Example 1, except that in Component Six, the F atom positions of the compounds represented by Formula IV-1 are different, specifically C2H5-Ph-CC-Ph(3F5F)-Ph-C3H7, and the content remains unchanged.

[0088] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0089] Example 24 It is carried out with reference to Example 1, except that Component Five (i.e., the compounds represented by Formula V-1, Formula V-2, and Formula V-3) is not contained, and Component Six (i.e., the compounds represented by Formula VI-1, Formula VI-1, and Formula VI-1) is not contained. At the same time, the mass ratios of the compounds represented by Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7, and Formula I-8 in Component One are kept the same as those in Example 1, and the content of Component One is adjusted proportionally to make up for the contents of Component Five and Component Six, and the total content sum of the composition remains 100%.

[0090] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0091] Comparative Example 1 It is carried out with reference to Example 1, except that Component Two (i.e., the compounds represented by Formula II-1, Formula II-2, Formula II-3, Formula II-4, Formula II-5, Formula II-6, Formula II-7, and Formula II-8) is not contained. At the same time, the mass ratios of the compounds represented by Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7, and Formula I-8 in Component One are kept the same as those in Example 1, and the content of Component One is adjusted proportionally to make up for the content of Component Two, and the total content sum of the composition remains 100%.

[0092] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0093] Comparative Example 2 It is carried out with reference to Example 1, except that Component Two (i.e., the compounds represented by Formula II-1, Formula II-2, Formula II-3, Formula II-4, Formula II-5, Formula II-6, Formula II-7, and Formula II-8) is not contained, and Component Five and Component Six are not contained. At the same time, the mass ratios of the compounds represented by Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7, and Formula I-8 in Component One are kept the same as those in Example 1, and the content of Component One is adjusted proportionally to make up for the contents of Component Two, Component Five, and Component Six, and the total content sum of the composition remains 100%.

[0094] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0095] Comparative Example 3 It was carried out with reference to Example 1, except that Component III (i.e., the compounds represented by Formula III-1, Formula III-2, Formula III-3 and Formula III-4) was not included. Meanwhile, the mass ratios of the compounds represented by Component I of Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7 and Formula I-8 were kept the same as those in Example 1, and the content of Component I was adjusted proportionally to make up for the content of Component III, with the total content of the composition remaining 100%.

[0096] And corresponding performance tests were carried out, and the test results are shown in Table 4.

[0097] Comparative Example 4 It was carried out with reference to Example 1, except that Component III (i.e., the compounds represented by Formula III-1, Formula III-2, Formula III-3 and Formula III-4) was not included, and Component V and Component VI were not included. Meanwhile, the mass ratios of the compounds represented by Component I of Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7 and Formula I-8 were kept the same as those in Example 1, and the content of Component I was adjusted proportionally to make up for the content of Component III, Component V and Component VI, with the total content of the composition remaining 100%.

[0098] And corresponding performance tests were carried out, and the test results are shown in Table 4.

[0099] Comparative Example 5 It was carried out with reference to Example 1, except that Component IV was not included. Meanwhile, the mass ratios of the compounds represented by Component I of Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7 and Formula I-8 were kept the same as those in Example 1, and the content of Component I was adjusted proportionally to make up for the content of Component IV, with the total content of the composition remaining 100%.

[0100] And corresponding performance tests were carried out, and the test results are shown in Table 4.

[0101] Comparative Example 5 It was carried out with reference to Example 1, except that Component IV was not included, and Component V and Component VI were not included. Meanwhile, the mass ratios of the compounds represented by Component I of Formula I-1, Formula I-2, Formula I-3, Formula I-4, Formula I-5, Formula I-6, Formula I-7 and Formula I-8 were kept the same as those in Example 1, and the content of Component I was adjusted proportionally to make up for the content of Component IV, Component V and Component VI, with the total content of the composition remaining 100%.

[0102] And corresponding performance tests were carried out, and the test results are shown in Table 4.

[0103] Comparative Example 6 It is carried out with reference to Example 1, except that in Component II, the positions of the F atoms in the compound shown in Formula II-5 are different, specifically C2H5-Ch-Ph(2F3F)-CC-Ph-OC2H5, and the content remains unchanged.

[0104] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0105] Comparative Example 7 It is carried out with reference to Example 1, except that in Component III, the positions of the F atoms in the compound shown in Formula III-1 are different, specifically C2H5-Ch(2F3F)-Ch-CH2O-Ph-OC2H5, and the content remains unchanged.

[0106] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0107] Comparative Example 8 It is carried out with reference to Example 1, except that in Component III, the benzene ring of the compound shown in General Formula IV does not contain F fluorine atoms, specifically CF3CH2-Ph-CF2CF2-Ph-C2H4CF3, and the content remains unchanged.

[0108] And corresponding performance tests are carried out, and the test results are shown in Table 4.

[0109] Table 4 Performance test results of liquid crystal compositions (Examples 7-24 and Comparative Examples 1-8)

[0110] From the test data of the above examples and comparative examples, it can be seen that compared with the comparative examples, the example solutions of the present invention are superior to the comparative examples in terms of phase transition temperature, refractive index anisotropy, solid state transition temperature, haze transition value, response speed, etc. This shows that the solution of the present invention has high long-term stability in both extremely hot and extremely cold environments, excellent high and low temperature resistance, and is very suitable for outdoor dimming devices.

[0111] While the comparative example solutions are difficult to achieve both fast response and good high and low temperature tolerance at the same time.

[0112] Compared with Example 1, Tcn in Examples 7-10 increased by 10-17 °C, proving the key role of long-chain alkyls in low-temperature stability and scattering efficiency.

[0113] Compared with Example 1, Tcn in Examples 11, 19, and 22 increased by 5-8 °C, showing the importance of branched-chain structures in suppressing crystallization.

[0114] The preferred embodiments of the present invention have been elaborated in detail above, but the scope of the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions, including combining each technical feature in other suitable ways. These modifications and combinations also belong to the content disclosed by the present invention and are all included in the protection scope of the present invention.

Claims

1. A liquid crystal composition, characterized in that, Comprising: Component 1, selected from at least one of the compounds represented by General Formula I, wherein in the structural formula, R1 and R2 are each independently selected from C1-C6 alkyl groups, and Z1 is selected from a carbon-carbon single bond or a carbon-carbon triple bond; Component 2, selected from at least one of the compounds represented by General Formula II, wherein in the structural formula, R3 and R4 are each independently selected from C1-C6 alkyl groups, and Z2 is selected from a carbon-carbon single bond or a carbon-carbon triple bond; Component 3, selected from at least one of the compounds represented by General Formula III, wherein in the structural formula, R5 is selected from C1-C6 alkyl groups; Component 4, selected from at least one of the compounds represented by General Formula IV, wherein in the structural formula, m and n are each independently selected from the integers 1, 2, 3, 4, 5; wherein, based on the total weight of the liquid crystal composition, the content of Component 1 is 5%-35%, the content of Component 2 is 5%-30%, the content of Component 3 is 1%-25%, and the content of Component 4 is 1%-20%; and the compounds of each general formula can be used alone or in combination; Each general formula is as follows: I Ⅱ Ⅲ Ⅳ。 2. The liquid crystal composition according to claim 1, characterized in that, The liquid crystal composition contains a benzene ring, and each of the two carbon atoms of the benzene ring is substituted with one F atom, and the benzene ring is connected to an alicyclic group or an aromatic ring group through a linking group selected from a carbon-carbon single bond or a carbon-carbon triple bond.

3. The liquid crystal composition according to claim 2, characterized in that, The ratio of the number of the F atoms to the alicyclic group and the aromatic ring group is 1:1-5.

4. The liquid crystal composition according to claim 1, characterized in that: Component 1 includes the compounds represented by Formula I-5, Formula I-6, Formula I-7 and Formula I-8, and at least one selected from the group consisting of the compounds represented by Formula I-1, Formula I-2, Formula I-3, Formula I-4 Component 2 includes the compounds represented by Formula II-5, Formula II-6, Formula II-7 and Formula II-8, and at least one selected from the group consisting of the compounds represented by Formula II-1, Formula II-2, Formula II-3, Formula II-4; Component 3 includes the compounds represented by Formula III-1 and Formula III-2, and at least one selected from the group consisting of the compounds represented by Formula III-3, Formula III-4; The sum of m and n in Component 4 satisfies the relationship 3≤m + n≤6; Wherein, each general formula is as follows: I-1 I-2 I-3 I-4 I-5 I-6 I-7 I-8 Ⅱ-1 Ⅱ-2 Ⅱ-3 Ⅱ-4 Ⅱ-5 Ⅱ-6 Ⅱ-7 Ⅱ-8 Ⅲ-1 Ⅲ-2 Ⅲ-3 Ⅲ-4。 5. The liquid crystal composition according to claim 1, characterized in that, The liquid crystal composition further includes Component 5, selected from at least one of the group consisting of the compounds represented by General Formula V-1, V-2, V-3; Wherein, in General Formula V-1, V-2, V-3: Ra, Rc, Re are each independently selected from C2-C6 alkyl groups; Rb, Rd, Rf are each independently selected from C1-C5 alkyl groups or C1-C5 alkoxy groups; P is selected from 0 or 1; Each general formula is as follows: V-1 V-2 V-3。 6. The liquid crystal composition according to claim 5, characterized in that, The liquid crystal composition further includes Component 6, selected from at least one of the group consisting of the compounds represented by General Formula VI-1, General Formula VI-2 and General Formula VI-3; Wherein, in General Formula VI-1, VI-2, VI-3: Rg, Rh, Rj are each independently selected from C2-C5 alkyl groups; Rk is selected from at least one of methyl, ethyl, methoxy or ethoxy; Each general formula is as follows: VI-1 VI-2 VI-3.

7. The liquid crystal composition according to claim 6, wherein: Based on the total weight of the liquid crystal composition, the total content of the compound represented by the general formula I is 10% - 30%; the total content of the compound represented by the general formula II is 10% - 28%; the total content of the compound represented by the general formula III is 3% - 15%; the total content of the compound represented by the general formula IV in the liquid crystal material is 5% - 15%; the total content of the compounds represented by the general formulas V-1, V-2, and V-3 is 0% - 15%; the total content of the compounds represented by the general formulas VI-1, VI-2, and VI-3 is 0% - 15%.

8. The liquid crystal composition according to claim 1, characterized in that, The transition temperature from the liquid crystal phase state to the isotropic phase state of the liquid crystal composition is ≥90 °C.

9. A device, which comprises the liquid crystal composition according to any one of claims 1 - 8.

10. The element according to claim 9, characterized in that, The device is an electro - controlled dimming device.

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