Liquid crystal composition and application thereof

Abstract

The invention relates to the technical field of liquid crystal display, in particular to a liquid crystal composition and application thereof. The liquid crystal composition provided by the invention contains the dialkynyl compound, has excellent performances of low rotary viscosity, large elastic constant, good low-temperature intersolubility, high response speed and the like while having small optical dispersion and high transmittance, and can be used for fast-response liquid crystal display of various display modes; when the liquid crystal composition is applied to a VA, IPS or FFS mode display, the display effect of a liquid crystal display can be obviously improved, and the liquid crystal composition is particularly suitable for IPS and FFS mode liquid crystal displays.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition and its applications. Background Art

[0002] With the progress of the information age, as an information display technology, liquid crystal display technology is also constantly developing. People's requirements for the performance of liquid crystal displays are getting higher and higher, which has stimulated people's interest in liquid crystal materials, making liquid crystal technology a research hotspot and continuing to develop.

[0003] From the perspective of formulating liquid crystal composition materials applied to liquid crystal displays, the various performance aspects of the materials affect each other. Improving some aspects of performance often comes with changes in other aspects. Therefore, studying the ways of combining various compounds has become the focus of current mixed liquid crystal materials, especially now when negative dielectric anisotropy materials are more widely used. However, in addition to examining the miscibility conditions of the liquid crystal composition, high clearing points, large dielectric anisotropy, low rotational viscosity and flow viscosity, fast response speed, etc. are all important properties for the liquid crystal composition to meet display requirements.

[0004] Currently, the main problems of liquid crystal displays are the relatively low contrast ratio of the displays and the relatively slow response time of the displays. How to improve these two aspects has become an important topic for liquid crystal displays. Through research, it is found that increasing the transmittance of the liquid crystal can greatly improve the contrast ratio of the liquid crystal display. Specifically, the transmittance of a liquid crystal display can be described by the following expression:

[0005]

[0006] In the formula, χ is the angle between the optical axis of the polarizer and the plane where the liquid crystal lies down, and λ is the light wavelength.

[0007] Generally speaking, the way to increase the transmittance is to increase the refractive index of the liquid crystal, thereby increasing the retardation amount and increasing the transmittance. However, since the transmittance of light with different wavelengths passing through the liquid crystal material is different, the smaller the refractive index dispersion of the liquid crystal material, the higher the comprehensive light transmittance. Therefore, developing a liquid crystal material with a smaller dispersion is one of the effective ways to improve the transmittance of the liquid crystal panel. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a liquid crystal composition and its applications. The liquid crystal composition provided by the present invention has excellent properties such as small light dispersion, high transmittance, low rotational viscosity, large elastic constant, good low-temperature miscibility, and fast response speed. It can be used for fast-response liquid crystal displays in various display modes, and can significantly improve the display effect of liquid crystal displays when applied to VA, IPS, or FFS mode displays, and is particularly suitable for IPS and FFS mode liquid crystal displays.

[0009] In a first aspect, the present invention provides a liquid crystal composition, which comprises one or more compounds represented by general formula I, one or more compounds represented by general formula II, one or more compounds represented by general formula III, one or more compounds represented by general formula IV, and one or more compounds represented by general formula V;

[0010] Wherein,

[0011]

[0012] wherein each of R1 and R2 is independently selected from any one of an alkyl group or an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group having 2 to 7 carbon atoms;

[0013]

[0014] wherein each of R3 and R4 is independently selected from any one of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms;

[0015]

[0016] wherein each of R5 and R6 is independently selected from any one of an alkyl group or an alkoxy group having 1 to 7 carbon atoms, and an alkenyl group having 2 to 7 carbon atoms, selected from any one of, - * represents a connecting bond of the group;

[0017]

[0018]

[0019] wherein R7 is selected from any one of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms, and R8 is selected from any one of an alkoxy group having 1 to 7 carbon atoms or an alkenyloxy group having 2 to 7 carbon atoms;

[0020]

[0021] wherein R9 is selected from any one of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms, and R 10 is selected from any one of an alkyl group or an alkoxy group having 1 to 7 carbon atoms, and an alkoxyalkenyl group having 2 to 7 carbon atoms, selected from any one of, - * represents a connecting bond of the group.

[0022] The liquid crystal composition provided by the present invention has excellent properties such as low rotational viscosity, large elastic constant, good low-temperature miscibility, and fast response speed while having small light dispersion and high transmittance. It can be used for fast-response liquid crystal displays in various display modes. When applied to VA, IPS, or FFS mode displays, it can significantly improve the display effect of liquid crystal displays, and is particularly suitable for IPS and FFS mode liquid crystal displays. Specifically:

[0023] In the liquid crystal composition provided by the present invention, the compound represented by General Formula I is a compound containing a diynyl group and has a relatively large n o and a relatively small n e , and its refractive index (Δn = n e -n o ) is negative, which can significantly reduce the dispersion of the liquid crystal composition and thus improve the transmittance of the liquid crystal display. The compound represented by General Formula II is a dicyclohexane compound and has good low-temperature solubility and low rotational viscosity. The compound represented by General Formula III is a tricyclic neutral compound and has a high clearing point and good low-temperature solubility. The compound represented by General Formula IV is a tricyclic negative compound with a methoxy bridge bond and has a large elastic constant and a large negative dielectric anisotropy, which can further improve the contrast of the liquid crystal display and reduce the driving voltage of the liquid crystal display. The compound represented by General Formula V is a tricyclic negative compound and has a relatively high clearing point and negative dielectric anisotropy. The synergistic effect of these compounds makes the liquid crystal composition provided by the present invention have excellent comprehensive performance, having small light dispersion and high transmittance while having excellent properties such as low rotational viscosity, large elastic constant, good low-temperature miscibility, and fast response speed, effectively solving the problem of low transmittance existing in current liquid crystal displays. When applied to VA, IPS, or FFS mode displays, it can significantly improve the display effect of liquid crystal displays, and is particularly suitable for IPS and FFS mode liquid crystal displays.

[0024] As a preferred technical solution of the present invention, the compound represented by General Formula I is selected from any one or more of the following compounds. Unless otherwise specified, the alkyl groups and alkoxy groups in the following structural formulas are all straight-chain structures:

[0025]

[0026]

[0027]

[0028] As a preferred technical solution of the present invention, the compound represented by General Formula II is selected from any one or more of the following compounds. Unless otherwise specified, the alkyl groups in the following structural formulas are all straight-chain structures:

[0029]

[0030]

[0031] As a preferred technical solution of the present invention, the compound represented by the general formula III is selected from any one or more of the following compounds. Unless otherwise specified, the alkyl groups and alkoxy groups in the following structural formulas are all straight-chain structures:

[0032]

[0033]

[0034]

[0035]

[0036] As a preferred technical solution of the present invention, the compound represented by the general formula IV is selected from any one or more of the following compounds. Unless otherwise specified, the alkyl groups and alkoxy groups in the following structural formulas are all straight-chain structures:

[0037]

[0038]

[0039] As a preferred technical solution of the present invention, the compound represented by the general formula V is selected from any one or more of the following compounds. Unless otherwise specified, the alkyl groups and alkoxy groups in the following structural formulas are all straight-chain structures:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047] As a preferred technical solution of the present invention, based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by the general formula I is 1-30%, the content of the compound represented by the general formula II is 1-50%, the content of the compound represented by the general formula III is 1-30%, the content of the compound represented by the general formula IV is 1-40%, and the content of the compound represented by the general formula V is 1-50%.

[0048] When the contents of the components in the liquid crystal composition provided by the present invention are within the above ranges, more significant synergistic effects can be achieved among the components, and the comprehensive performance of the liquid crystal composition can be more effectively improved.

[0049] As a preferred technical solution of the present invention, based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 5-30%, the content of the compound represented by General Formula II is 5-40%, the content of the compound represented by General Formula III is 1-20%, the content of the compound represented by General Formula IV is 5-40%, and the content of the compound represented by General Formula V is 10-40%.

[0050] As a preferred technical solution of the present invention, based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 10-30%, the content of the compound represented by General Formula II is 10-35%, the content of the compound represented by General Formula III is 5-20%, the content of the compound represented by General Formula IV is 10-35%, and the content of the compound represented by General Formula V is 20-40%.

[0051] As a preferred technical solution of the present invention, based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 15-25%, the content of the compound represented by General Formula II is 15-30%, the content of the compound represented by General Formula III is 10-20%, the content of the compound represented by General Formula IV is 15-30%, and the content of the compound represented by General Formula V is 20-30%.

[0052] There are no special restrictions on the preparation method of the liquid crystal composition of the present invention. Conventional methods can be used to mix two or more compounds for production, such as preparing by mixing different components at high temperature and dissolving them in each other. Among them, the liquid crystal composition is dissolved in a solvent for the compound and mixed, and then the solvent is distilled off under reduced pressure; or the liquid crystal composition of the present invention can be prepared according to conventional methods, such as dissolving the component with a smaller content in the main component with a larger content at a higher temperature, or dissolving each component in an organic solvent such as acetone, chloroform or methanol, etc., and then mixing the solutions and removing the solvent to obtain it.

[0053] In the second aspect, the present invention provides the application of the liquid crystal composition described in the first aspect in the field of liquid crystal display, preferably in VA, IPS or FFS mode displays.

[0054] The technical solutions provided by the embodiments of the present invention have the following advantages compared with the prior art:

[0055] The liquid crystal composition provided by the present invention has excellent properties such as low rotational viscosity, large elastic constant, good low-temperature miscibility, and fast response speed while having small optical dispersion and high transmittance. It can be used for fast-response liquid crystal displays in various display modes, and can significantly improve the display effect of liquid crystal displays when applied to VA, IPS, or FFS mode displays, and is particularly suitable for IPS and FFS mode liquid crystal displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments in accordance with the present invention, and are used together with the specification to explain the principles of the present invention.

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0058] Figure 1 It is the VT curve of the liquid crystal compositions of Example 1, Example 10, and Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0059] In order to more clearly understand the above objects, features, and advantages of the present invention, the following will further describe the solutions of the present invention. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0060] Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0061] Examples 1 - 2

[0062] This example provides a liquid crystal composition and a preparation method thereof. The components and their contents in the liquid crystal composition are shown in Table 1:

[0063] Table 1

[0064]

[0065]

[0066] The preparation method includes: weighing liquid crystal compounds by weight percentage using a balance, where there is no specific requirement for the weighing and adding order, and usually weighing and mixing them in the order of decreasing melting point of the liquid crystal compounds, heating and stirring at 60 - 100 °C to make each component dissolve evenly, then filtering, rotary evaporation, and finally encapsulating to obtain the product.

[0067] Examples 3 - 4

[0068] This example provides a liquid crystal composition and its preparation method. The preparation method is the same as that of Example 1. The components and their contents in the liquid crystal composition are shown in Table 2:

[0069] Table 2

[0070]

[0071] Examples 5 - 6

[0072] This example provides a liquid crystal composition and its preparation method. The preparation method is the same as that of Example 1. The components and their contents in the liquid crystal composition are shown in Table 3:

[0073] Table 3

[0074]

[0075] Examples 7 - 8

[0076] This example provides a liquid crystal composition and its preparation method. The preparation method is the same as that of Example 1. The components and their contents in the liquid crystal composition are shown in Table 4:

[0077] Table 4

[0078]

[0079]

[0080] Examples 9 - 10

[0081] This example provides a liquid crystal composition and its preparation method. The preparation method is the same as that of Example 1. The components and their contents in the liquid crystal composition are shown in Table 5:

[0082] Table 5

[0083]

[0084]

[0085] Comparative Example 1

[0086] This comparative example provides a liquid crystal composition and a preparation method thereof. The preparation method is the same as that of Example 1. The components and their contents in the liquid crystal composition are shown in Table 6:

[0087] Table 6

[0088] Compound Content / % ⅤA14 8 ⅤA10 9 IIA1 20.0 IIA2 6.0 IIB11 10.0 ⅢA2 10.0 ⅣA2 6.0 ⅤB10 5.0 ⅤB14 6.0 ⅢA3 10.0 ⅢC26 6.0 ⅣA6 2.0 ⅣA7 2.0

[0089] Performance test

[0090] The liquid crystal compositions obtained in the examples and comparative examples were tested:

[0091] (1) Δn represents the optical anisotropy (25 °C); Δε represents the dielectric anisotropy (25 °C, 1000 Hz); γ1 represents the rotational viscosity (mPa·s, 25 °C); K11 and K33 respectively represent the splay and bend elastic constants (pN, 25 °C). The results are shown in Table 7:

[0092] Table 7

[0093]

[0094] It can be found from Table 7 that compared with Comparative Example 1, for Examples 1 and 10, under the condition of the same Δn (589), the refractive index at short wavelengths is significantly smaller, while the refractive index at long wavelengths is significantly larger. Therefore, the light dispersion of the liquid crystal composition obtained in the examples of the present invention is smaller, and the transmittance of the liquid crystal display can be effectively improved.

[0095] (2) The performance parameter values of the liquid crystal compositions obtained in Example 1, Example 10 and Comparative Example 1 were compared by optical simulation, and the VT curves of the liquid crystal compositions of Example 1, Example 10 and Comparative Example 1 were obtained. The results are as Figure 1 and shown in Table 8.

[0096] Table 8

[0097] Item Comparative Example Example 1 Example 10 Tmax 0.2983 0.3145 0.3142 T％ 100％ 105.43％ 105.33％

[0098] It can be found that compared with Comparative Example 1, for Examples 1 and 10, the transmittance is increased by more than 5%. This indicates that when manufacturing a liquid crystal display under the same technical conditions, the liquid crystal composition provided by the present invention has a higher transmittance, can significantly reduce the brightness of the backlight, and thus achieve the effect of energy saving. In addition, compared with Comparative Example 1, the compound represented by General Formula I is reduced in the liquid crystal composition obtained in the examples of the present invention, and the liquid crystal composition has a higher penetration degree, indicating that there is a synergistic effect among the components in the liquid crystal composition, and the compound represented by General Formula I is an essential component in the liquid crystal composition provided by the present invention.

[0099] In summary, the liquid crystal composition provided by the present invention has a large elastic constant, high resistivity, suitable optical anisotropy, good low-temperature miscibility, low rotational viscosity, and excellent light and thermal stability. It can reduce the response time of liquid crystal displays, thus solving the problem of slow response speed of liquid crystal displays. Moreover, the liquid crystal composition provided by the present invention is applicable to fast-response VA, IPS, and FFS type TFT liquid crystal display devices, especially applicable to IPS and FFS liquid crystal display devices.

[0100] It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0101] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments described herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A liquid crystal composition, characterized in that, The liquid crystal composition comprises one or more compounds represented by General Formula I, one or more compounds represented by General Formula II, one or more compounds represented by General Formula III, one or more compounds represented by General Formula IV, and one or more compounds represented by General Formula V; wherein, R1 and R2 are each independently selected from any one of an alkyl group or an alkoxy group having 1 to 7 carbon atoms and an alkenyl group having 2 to 7 carbon atoms; wherein, R3 and R4 are each independently selected from any one of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms; wherein R5 and R6 are each independently selected from any one of alkyl or alkoxy groups having 1 to 7 carbon atoms and alkenyl groups having 2 to 7 carbon atoms, selected from any one of; wherein, R7 is selected from any one of an alkyl group having 1 to 7 carbon atoms or an alkenyl group having 2 to 7 carbon atoms, and R8 is selected from any one of an alkoxy group having 1 to 7 carbon atoms or an alkenyloxy group having 2 to 7 carbon atoms; Among them, R9 is selected from any one of alkyl groups having 1 to 7 carbon atoms or alkenyl groups having 2 to 7 carbon atoms, and R 10 is selected from any one of alkyl groups or alkoxy groups having 1 to 7 carbon atoms, or alkoxyalkenyl groups having 2 to 7 carbon atoms, is selected from any one of them, and -* represents the connecting bond of the group.

2. The liquid crystal composition according to claim 1, characterized in that, The compound represented by General Formula I is selected from any one or more of the following compounds:

3. The liquid crystal composition according to claim 1 or 2, characterized in that, The compound represented by General Formula II is selected from any one or more of the following compounds:

4. The liquid crystal composition according to any one of claims 1 to 3, characterized in that The compound represented by General Formula III is selected from any one or more of the following compounds:

5. The liquid crystal composition according to any one of claims 1-4, characterized in that The compound represented by General Formula IV is selected from any one or more of the following compounds:

6. The liquid crystal composition according to any one of claims 1-5, characterized in that, The compound represented by General Formula V is selected from any one or more of the following compounds:

7. The liquid crystal composition according to any one of claims 1-6, characterized in that, Based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 1 - 30%, the content of the compound represented by General Formula II is 1 - 50%, the content of the compound represented by General Formula III is 1 - 30%, the content of the compound represented by General Formula IV is 1 - 40%, and the content of the compound represented by General Formula V is 1 - 50%.

8. The liquid crystal composition according to claim 7, characterized in that, Based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 5 - 30%, the content of the compound represented by General Formula II is 5 - 40%, the content of the compound represented by General Formula III is 1 - 20%, the content of the compound represented by General Formula IV is 5 - 40%, and the content of the compound represented by General Formula V is 10 - 40%.

9. The liquid crystal composition according to claim 8, wherein, Based on the total mass of the liquid crystal composition being 100%, the content of the compound represented by General Formula I is 10 - 30%, the content of the compound represented by General Formula II is 10 - 35%, the content of the compound represented by General Formula III is 5 - 20%, the content of the compound represented by General Formula IV is 10 - 35%, and the content of the compound represented by General Formula V is 20 - 40%.

10. Use of the liquid crystal composition according to any one of claims 1 - 9 in the field of liquid crystal display.

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