Liquid crystal compound, liquid crystal composition and liquid crystal display element or display thereof

Abstract

The invention discloses a liquid crystal compound, the structural formula of the liquid crystal compound is as shown in the following formula I, # imgabs0. The liquid crystal compound has high elastic constant K, high dielectric anisotropy delta epsilon, high clearing point Cp, good low-temperature intersolubility, small optical anisotropy delta n and small scattering coefficient; the liquid crystal composition containing the liquid crystal composition has a high elastic constant K, high dielectric anisotropy delta epsilon, a high clearing point Cp, good low-temperature intersolubility, small optical anisotropy delta n and a small scattering coefficient. The liquid crystal composition can be used for developing liquid crystal display elements or liquid crystal displays which have the advantages of high response speed, high contrast ratio, wide display temperature range, good low-temperature intersolubility and good reliability and can effectively improve residual images.

Description

Technical Field

[0001] The present invention relates to the field of liquid crystal display technology, and specifically comprises a liquid crystal compound, a liquid crystal composition comprising the liquid crystal compound, and a liquid crystal display element or display thereof. Background Art

[0002] With the development of display technology, flat-panel display devices such as liquid crystal display (LCD) have been widely used in various consumer electronic products such as mobile phones, televisions, personal digital assistants, digital cameras, laptops, desktop computers, etc. due to their advantages such as high image quality, power saving, thin body and wide application range. They have become the mainstream in display devices and eventually replaced cathode ray tube displays.

[0003] Liquid crystal displays are classified into TN (twist nematic), STN (supertwisted nematic), IPS (in-plane switching), VA (vertical alignment) and other types according to the type of display mode.

[0004] Liquid crystal display devices contain liquid crystal materials, wherein the liquid crystal material is a mixture of organic rod-shaped small molecular compounds that have both liquid fluidity and crystal anisotropy at a certain temperature. Liquid crystal materials are widely used in display devices such as electronic calculators, notebooks, automobile instruments, and televisions because of their optical anisotropy and dielectric anisotropy. Liquid crystal media with good chemical and thermal stability, good stability to electric fields and electromagnetic radiation, appropriate optical anisotropy, small rotational viscosity, and good low-temperature miscibility are currently in urgent need, especially since liquid crystals are usually mixed with multiple components, and the direct miscibility of the components is particularly important. At the same time, since liquid crystal compounds are generally sensitive to ultraviolet rays, conventional liquid crystal materials are usually combined with additives with anti-UV functions in order to avoid damage caused by ultraviolet rays. Among them, the most widely used are fluorinated quaternary compounds. Although the addition of fluorinated quaterphenyl compounds to liquid crystal compositions improves the UV resistance of liquid crystals, there is no obvious effect on improving image quality. The addition of some compounds also affects low-temperature stability. This is not as we conventionally believe that the less rigid structure and the more substituents, the better the solubility. This may be related to various forces within or between molecules. A lot of research work still needs to be done to address this defect.

[0005] With the advancement of technology, people have higher and higher requirements for monitors, requiring the images on monitors to be clearer and better in quality, and no tailing during screen switching. The contrast ratio (CR, which refers to the ratio of the brightness of a point on the screen when it is brightest to the brightness when it is darkest) is highly related to the image quality display. The higher the contrast ratio, the clearer the image quality, the brighter the colors displayed by the monitor, and the richer the layering. The contrast ratio of common LCD monitors is generally greater than 1000:1. The specific definition of contrast ratio is as follows:

[0006] CR=Tr 亮 / Tr 暗

[0007] T 暗 ∝1 / S LC ; S LC ={(n e +n o ) 2 *△n 2} / K ave ; K ave =(K 11 +K 22 +K 33 ) / 3

[0008] Among them, Tr 亮 Indicates the brightness of the bright state, Tr 暗 Indicates the brightness in the dark state, S LC represents the scattering coefficient of the liquid crystal layer.

[0009] From the definition of contrast, we can see that there are two main ways to improve contrast: on the one hand, it is to increase the brightness of the display in the bright state, and on the other hand, it is to reduce the brightness in the dark state, that is, to make the bright state brighter and the dark state darker. However, in the conventional research and development process, most of them will not improve the contrast by improving the brightness of the bright state, because the main factor affecting the brightness of the bright state is the transmittance, and the main factor affecting the transmittance is the phase delay of the liquid crystal box △nd. The larger the △nd, the greater the transmittance. However, due to the need to consider other factors such as color deviation and viewing angle, the variable range of △nd is small, and the contribution to improving the contrast is limited. Therefore, reducing the brightness of the dark state is the main direction for improving the contrast. Affected by the arrangement state of the liquid crystal, the liquid crystal display will have a certain degree of light leakage in the dark state, that is, the brightness of the dark state cannot reach absolute black, and a slight change in the brightness of the dark state will have a greater impact on the contrast. Therefore, at present, the contrast is mainly improved by reducing the brightness in the dark state. To reduce the contrast in the dark state, it is necessary to start with the elastic constant of the liquid crystal composition. The increase in the elastic constant is conducive to reducing the brightness of the dark state. The color film and liquid crystal material scatter light. It can be seen from the optical principle that during the scattering process, the polarization state of the incident light will change. Therefore, in the dark state, the polarized light passing through the lower polarizer is perpendicular to the transmission axis of the upper polarizer and cannot be transmitted. However, when the polarized light is scattered in the liquid crystal and color film material, part of the polarization state changes. The changed polarized light has a component in the transmission axis direction of the upper polarizer, so it is projected out of the upper polarizer, forming light leakage, thereby reducing the contrast. The stronger the scattering, the greater the contrast reduction. Therefore, the panel manufacturers in the industry are currently actively exploring ways to reduce the brightness of the dark state, that is, how to increase the polarization degree of the polarizer, improve the orientation characteristics of the liquid crystal, develop high-contrast color resistance materials, and develop high-contrast liquid crystals. The development of high-contrast liquid crystals is the direction of common efforts of liquid crystal manufacturers. For example, to develop highly contrasting liquid crystals, liquid crystal compounds or liquid crystal compositions with a larger elastic constant K and a liquid crystal composition with a smaller scattering coefficient are required.

[0010] Most of the car display screens use TFT LCD screens. Due to the special use environment of car display screens, compared with ordinary LCD screens, car display screens are generally required to be moisture-proof, dust-proof, anti-glare, visible in the sun, and resistant to high and low temperatures. Therefore, LCD car display screens usually use LCD technologies such as wide temperature, anti-glare, high brightness, and capacitive touch.

[0011] Therefore, developing a liquid crystal medium with a high elastic constant K, good low-temperature miscibility and good UV resistance is a technical problem that needs to be solved urgently. Summary of the invention

[0012] In view of this, the present invention provides a liquid crystal compound, a liquid crystal composition and a liquid crystal display element or display thereof. The liquid crystal compound has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature miscibility, a small optical anisotropy Δn, and a small scattering coefficient. The liquid crystal composition of the present invention has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature miscibility, a small optical anisotropy Δn, and a small scattering coefficient, and can be used to develop a liquid crystal display element or liquid crystal display with a faster response speed, high contrast, a wider display temperature range, good low-temperature miscibility and good reliability, and can effectively improve the afterimage.

[0013] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0014] The first aspect of the present invention provides a liquid crystal compound, the general structural formula of the compound is as shown in Formula I,

[0015]

[0016] Wherein, R represents an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and one or more H atoms in the alkyl group or alkenyl group may be optionally substituted by halogen; and / or any one or more -CH2- in the alkyl group may be independently optionally substituted by -C≡C-, -CH=CH-, -O-, -S-, -CO-O- or -O-CO-substituted, and the O and S atoms in the substituent are not directly connected to each other;

[0017] L1 and L2 are independently selected from H or F;

[0018] X is selected from any one of F, Cl, CN, an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, a fluorinated alkyl group, a fluorinated alkenyl group, a fluorinated alkoxy group, and a fluorinated alkenyloxy group.

[0019] A second aspect of the present invention provides a liquid crystal composition, which includes the above-mentioned liquid crystal compound.

[0020] A third aspect of the present invention provides a liquid crystal display element or a liquid crystal display, wherein the liquid crystal display element or the liquid crystal display comprises the aforementioned liquid crystal compound and the liquid crystal composition.

[0021] The beneficial effects of the present invention are as follows:

[0022] The liquid crystal compound of the present invention has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature mutual solubility, a small optical anisotropy Δn, and a small scattering coefficient. The liquid crystal composition containing the liquid crystal compound of the present invention has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature mutual solubility, a small optical anisotropy Δn, and a small scattering coefficient. It can be used to develop a liquid crystal display element or liquid crystal display with a faster response speed, high contrast, a wider display temperature range, good low-temperature mutual solubility and good reliability, and can effectively improve the residual image. The liquid crystal compound of the present invention and the liquid crystal composition containing the liquid crystal compound of the present invention are particularly suitable for vehicle-mounted liquid crystal displays, and have performance advantages such as good contrast and a wider temperature display range. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The MS spectrum of the compound represented by I-10-2 is shown. DETAILED DESCRIPTION

[0024] The present invention provides a liquid crystal compound, the general structural formula of the compound is as shown in Formula I,

[0025]

[0026] Wherein, R represents an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and one or more H atoms in the alkyl group or alkenyl group may be optionally substituted by halogen; and / or any one or more -CH2- in the alkyl group may be independently optionally substituted by -C≡C-, -CH=CH-, -O-, -S-, -CO-O-, or -O-CO- are substituted in such a way that the O and S atoms are not directly attached to each other;

[0027] L1 and L2 are independently selected from H or F;

[0028] X is selected from any one of F, Cl, CN, an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, a fluorinated alkyl group, a fluorinated alkenyl group, a fluorinated alkoxy group, and a fluorinated alkenyloxy group.

[0029] In the liquid crystal compound of the present invention, preferably, the aforementioned R is selected from one of a chain alkyl group having 1 to 10 carbon atoms, a chain alkyl group having 1 to 10 carbon atoms substituted with fluorine, an alkenyl group having 2 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms substituted with fluorine; and the aforementioned X is selected from any one of F, CF3 or OCF3.

[0030] The liquid crystal compound of the present invention is preferably a compound represented by the aforementioned formula I selected from any one or any combination of the compounds represented by the following formulas I-1 to I-12,

[0031]

[0032] Here, R is selected from one of an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with fluorine, an alkenyl group having 2 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms substituted with fluorine.

[0033] The liquid crystal compound of the present invention is further preferably selected from the compound represented by formula I-10. Further preferably, the mass content of the liquid crystal compound in the liquid crystal composition is 2-13%, and further preferably, the mass content of the liquid crystal compound is 5-9%.

[0034] The liquid crystal compound of the present invention is preferably selected from any one or any combination of the compounds represented by the aforementioned formulas Ⅰ-1 to Ⅰ-12,

[0035]

[0036]

[0037] The liquid crystal compound of the present invention preferably comprises the compound represented by formula I-10-2. Further preferably, the mass content of the compound represented by formula I-10-2 is 3-9%.

[0038] The present invention provides a liquid crystal composition, which comprises one or more liquid crystal compounds of the present invention.

[0039] The liquid crystal composition of the present invention, preferably, further comprises one or more compounds represented by formula II,

[0040]

[0041] wherein R1 and R2 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms;

[0042] Each independently expresses

[0043] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II is selected from the group consisting of the compounds represented by the following formulas II-1 to II-3,

[0044]

[0045] Here, R1 and R2 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms.

[0046] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-1 is selected from the group consisting of compounds represented by the following formulae II-1-1 to II-1-12,

[0047]

[0048]

[0049] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-1 contains at least the compound represented by the formula II-1-6; further preferably, the mass content of the compound represented by the formula II-1-6 is ≥31%; further preferably, the mass content of the compound represented by the formula II-1-6 is ≥35%. In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-1 contains at least two compounds selected from the group consisting of compounds represented by formula II-1-6, II-1-7 or II-1-8, and further preferably, the mass content of the compound represented by the formula II-1 is 35-45%.

[0050] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-2 is selected from the group consisting of the compounds represented by the following formulae II-2-1 to II-2-6,

[0051]

[0052] The liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-2 contains at least the compound represented by formula II-2-2, and the mass content of the compound represented by formula II-2 is 0.1-5%, and more preferably, the mass content is 1-3%.

[0053] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-3 is selected from the group consisting of the compounds represented by the following formulae II-3-1 to II-3-6,

[0054]

[0055] The liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II-3 contains at least the compound represented by formula II-3-4; further preferably, the mass content of the compound represented by formula II-3-4 is 0-10%; further preferably, the mass content of the compound represented by formula II-3-4 is 3-7%.

[0056] The liquid crystal composition of the present invention, preferably, further comprises one or more compounds represented by formula III or formula IV,

[0057]

[0058] wherein R3 and R4 each independently represent an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms; one or more non-adjacent -CH2- in R3 may be optionally substituted by a cyclopentylene group or a cyclopropylene group;

[0059] X1 and X3 each independently represent -H or -F;

[0060] X2 represents -F, -CF3 or -OCF3;

[0061] Each independently expresses

[0062] m and n each independently represent 1, 2 or 3, and when m and n are 2 or 3, two or three Can be the same or different;

[0063] b represents 0 or 1.

[0064] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III is selected from the group consisting of compounds represented by the following formulae III-1 to III-8,

[0065]

[0066] Wherein, R3 represents an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms; one or more non-adjacent -CH2- in R3 may be substituted by a cyclopentylene group or a cyclopropylene group.

[0067] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III contains at least two compounds selected from the group consisting of compounds represented by formula III-1, III-2, III-4, III-5, and III-8. In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by formula III-1 is 0-11%, and more preferably, the mass content is 3-7%. In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by formula III-2 is 1-10%, and more preferably, the mass content is 3-7%. In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by formula III-4 is 0-10%, and more preferably, the mass content is 2-6%. In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by formula III-5 is 1-7%, and more preferably, the mass content is 2-5%. In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by formula III-8 is 0-7%, and more preferably, the mass content is 3-5.5%.

[0068] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-1 is selected from the group consisting of compounds represented by the following formulae III-1-1 to III-1-4,

[0069]

[0070] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-2 is selected from the group consisting of compounds represented by the following formulae III-2-1 to III-2-5,

[0071]

[0072] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-3 is selected from the group consisting of compounds represented by the following formulae III-3-1 to III-3-6,

[0073]

[0074] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-4 is selected from the group consisting of the compounds represented by the following formulae III-4-1 to III-4-3,

[0075]

[0076] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-5 is selected from the group consisting of compounds represented by the following formulae III-5-1 to III-5-6,

[0077]

[0078] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-5 contains at least the compound represented by formula III-5-2, and the mass content of the compound represented by formula III-5 is 2-5%.

[0079] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-6 is selected from the group consisting of compounds represented by the following formulae III-6-1 to III-6-5,

[0080]

[0081] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-7 is selected from the group consisting of the compounds represented by the following formulae III-7-1 to III-7-4,

[0082]

[0083] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-8 is selected from the group consisting of the compounds represented by the following formulae III-8-1 to III-8-4,

[0084]

[0085]

[0086] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula IV is selected from the group consisting of compounds represented by the following formulae IV-1 to IV-25,

[0087]

[0088] Here, R4 represents an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms.

[0089] The liquid crystal composition of the present invention, preferably, further comprises one or more compounds represented by formula V,

[0090]

[0091] wherein R5 and R6 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms;

[0092] express

[0093] r means 2 or 3; and two or three Can be the same or different.

[0094] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V is selected from the group consisting of compounds represented by the following formulas V-1 to V-7,

[0095]

[0096] Here, R5 and R6 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms.

[0097] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-1 is selected from the group consisting of the compounds represented by the following formulas V-1-1 to V-1-7,

[0098]

[0099] The liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-1 contains compounds represented by formula V-1-6 and / or formula V-1-7, and the mass content of the compound represented by formula V-1 is 13-22%; further preferably, the mass content of the compound represented by formula V-1-6 is 5-15%, and the mass content of the compound represented by formula V-1-7 is 4-11%.

[0100] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-2 is selected from the group consisting of the compounds represented by the following formulas V-2-1 to V-2-10,

[0101]

[0102] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-2 includes the compound represented by formula V-2-9.

[0103] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V is selected from the group consisting of compounds represented by the following formulas V-3-1 to V-3-19,

[0104]

[0105]

[0106] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-4 is selected from the group consisting of compounds represented by the following formulas V-4-1 to V-4-5,

[0107]

[0108] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-5 is selected from the group consisting of compounds represented by the following formulas V-5-1 to V-5-4,

[0109]

[0110] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-6 is selected from the group consisting of the compounds represented by the following formulas V-6-1 to V-6-3,

[0111]

[0112] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-7 is selected from the group consisting of the compounds represented by the following formulas V-7-1 to V-7-3,

[0113]

[0114]

[0115] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V-8 is selected from the group consisting of the compounds represented by the following formulas V-8-1 to V-8-11,

[0116]

[0117] The liquid crystal composition of the present invention, preferably, further comprises a compound represented by formula VI,

[0118]

[0119] wherein R7 and R8 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms;

[0120] Z represents -C=C-, -CH2-CH2- or -CH2O-.

[0121] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VI is selected from the group consisting of compounds represented by the following formulae VI-1 to VI-6,

[0122]

[0123] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VI includes the compound represented by formula VI-5, and the mass content of the compound represented by formula VI-5 is 0-10%, and further preferably, the mass content of the compound represented by formula VI-5 is 3-7%.

[0124] The liquid crystal composition of the present invention, preferably, further comprises a compound represented by formula VII,

[0125]

[0126] Among them, R9, R 10 Each independently represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; and a represents 0 or 1.

[0127] The liquid crystal composition of the present invention, preferably, further comprises one or more compounds represented by formula VIII,

[0128]

[0129] Among them, R 11 , R 12 Each independently represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms;

[0130] express

[0131] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VII is selected from the group consisting of compounds represented by the following formulae VII-1 to VII-3,

[0132]

[0133] In the liquid crystal composition of the present invention, it is further preferred that the compound represented by the aforementioned formula VIII contains at least one or more compounds represented by formula VIII-2. Even more preferably, the mass content of the compound represented by the aforementioned formula VIII-2 is 2-7%.

[0134] In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VIII-2 is selected from the group consisting of compounds represented by the following formulas VIII-2-1 to VIII-2-22,

[0135]

[0136]

[0137] Other additives may also be added to the liquid crystal composition of the present invention, such as UV stabilizers, antioxidants, free radical scavengers, etc. The additives that can be listed are as follows:

[0138]

[0139] Here, u represents an alkylene group having 1 to 20 carbon atoms.

[0140] [Liquid crystal display element or liquid crystal display]

[0141] The present invention also provides a liquid crystal display element or a liquid crystal display comprising the liquid crystal compound or liquid crystal composition.

[0142] Preferably, the aforementioned liquid crystal display element may be an active matrix addressed liquid crystal display element or a liquid crystal display.

[0143] Preferably, the active matrix addressed liquid crystal display element is a VA-TFT, FFS-TFT or IPS-TFT liquid crystal display element.

[0144] The liquid crystal display element or liquid crystal display of the present invention comprises the liquid crystal compound and liquid crystal composition of the present invention, and can be used to develop a liquid crystal display element or liquid crystal display having good reliability, a wide operating temperature range and a high contrast ratio.

[0145] Example

[0146] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the content specifically described below is illustrative and not restrictive, and the protection scope of the present invention should not be limited to this. The embodiments and comparative examples of this specification are provided to more completely explain this specification to those skilled in the art, and can be deformed into various different forms according to the embodiments and comparative examples of this specification, and the protection scope of the present invention should not be limited only to the embodiments and comparative examples described in detail below.

[0147] Synthesis Examples of Compounds

[0148]

[0149] The present invention is further described below in conjunction with specific examples, but the present invention is not limited to the following examples. The methods described are conventional methods unless otherwise specified. The raw materials described can be obtained from public commercial channels unless otherwise specified.

[0150] The progress of the reaction is generally monitored by TLC. The post-treatment after the reaction is generally washing with water, extraction, drying after combining the organic phases, removing the solvent under reduced pressure, and recrystallization and column chromatography. Those skilled in the art can implement the present invention according to the following description.

[0151] Example 1

[0152] This embodiment provides a liquid crystal compound I-1-2, whose structural formula is as follows:

[0153]

[0154] The synthetic route of the compound is as follows:

[0155]

[0156] Step (1)

[0157] Dissolve 4-fluorobromobenzene (20 g, 0.0948 mol) in tetrahydrofuran (60 ml) to obtain 4-fluorobromobenzene tetrahydrofuran solution. Dissolve monoethylene glycol 4,4'-bicyclodione (20 g, 0.0853 mol) in tetrahydrofuran (40 ml) to obtain monoethylene glycol 4,4'-bicyclodione tetrahydrofuran solution. Add magnesium (2.5 g, 0.1043 mol) into a 250 mL three-necked flask, add the above 4-fluorobromobenzene and tetrahydrofuran dropwise to initiate the reaction, and continue Add dropwise until the addition of p-fluorobromobenzene and tetrahydrofuran is complete, reflux for 1 hour, add the above monoethylene glycol condensate tetrahydrofuran solution, reflux for 1 hour, cool to room temperature, pour the reaction solution into 50 ml of water, adjust the pH to 3-4 with 1 mol / L hydrochloric acid, extract with ethyl acetate, combine the organic phases, rinse with 100 ml of brine, dry with anhydrous sodium sulfate, and evaporate to dryness to obtain a yellow solid intermediate 1 (27.3 g, yield 86%);

[0158] Step (2)

[0159] Into a 250mL three-necked flask, intermediate 3 (27.3g, 0.08795mol), toluene (100ml) and p-toluenesulfonic acid (2.7g) were added, refluxed, water was separated with a water separator, reacted for 3h, cooled to room temperature, water was added to the reaction solution, separated, washed with water, passed through a column, and rotary evaporated to obtain a crude product, which was recrystallized from isopropanol, frozen at -20°C for crystallization for 4h, and suction filtered to obtain a white solid intermediate 2 (20.8g, yield 84%);

[0160] Step (3)

[0161] In a 250 mL three-necked flask, intermediate 4 (21.8 g, 0.06186 mol), toluene (100 ml) and formic acid (42.7 g, 0.9279 mol) were added, and the mixture was refluxed for 5 h. The temperature was cooled to room temperature, and the reaction solution was poured into water, separated, washed with water, passed through a column, and rotary evaporated to obtain intermediate 3 (17.1 g, yield 90%) as a yellow oil.

[0162] Step (4)

[0163] Chloromethyl ether phosphonium salt (28.5 g, 0.08318 mol) and tetrahydrofuran (100 ml) were added to a 500 mL three-necked flask, potassium tert-butoxide (9.3 g, 0.08318 mol) was added at 0° C., the reaction was carried out at 0° C. for 0.5 hours, intermediate 5 (17.1 g, 0.05545 mol) was added dropwise at 0° C., the reaction was completed at 0° C. for 1 hour, water was added to the reaction solution, the mixture was stirred and separated, ethyl acetate was extracted, the mixture was washed with water, the solvent was spin-dried, petroleum ether was pulped, the filter cake was discarded, and the filtrate was spin-dried to obtain a white solid intermediate 4 (13.2 g, yield 70%);

[0164] Step (5)

[0165] Add intermediate 6 (13.2 g, 0.04102 mol), hydrochloric acid (3.6 g, 0.09845 mol) and tetrahydrofuran (100 ml) into a 250 mL three-necked flask, react at 60 ° C for 4 hours, and the reaction is completed. Cool to room temperature, separate the liquid, extract with ethyl acetate, wash with water, and spin dry the solvent to obtain yellow oily intermediate 5 (13.2 g, yield 100%);

[0166] Step (6)

[0167] Add intermediate 7 (13.2 g, 0.04126 mol), triethylamine (0.8 g, 0.00825 mol), sodium hydroxide (0.2 g, 0.004126 mol) and methanol (100 ml) into a 250 mL three-necked flask, cool to 0°C to -10°C, react for 4 h, freeze the reaction solution at -50°C for 4 h, filter and dry to obtain white solid intermediate 6 (11.8 g, yield 89.4%);

[0168] Step (7)

[0169] Into a 250mL three-necked flask, intermediate 8 (4.8g, 0.0149mol), propyl propanediol (2.1g, 0.01787mol), toluene (100ml) and p-toluenesulfonic acid (0.3g, 0.00149mol) were placed, the temperature was raised to 110°C, water was separated with a water separator, the reaction was continued for 3h, the temperature was cooled to room temperature, water was added to the reaction solution, the solution was separated, the solution was washed with water, the solution was passed through a column, and the crude product was obtained by rotary evaporation. The crude product was recrystallized from toluene petroleum ether, and suction filtered to obtain white solid compound Ⅰ-1-2 (5.7g, yield 90%), MS (m / z) (M+): 386.55.

[0170] Example 2

[0171] This embodiment provides a liquid crystal compound I-2-1, whose structural formula is as follows:

[0172]

[0173] The synthetic route of the compound is as follows:

[0174]

[0175] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by p-trifluoromethylbromobenzene, and the final product Ⅰ-2-1 (4.5 g, yield 80%) is obtained, MS (m / z) (M+): 436.56.

[0176] Example 3

[0177] This embodiment provides a liquid crystal compound I-3-2, whose structural formula is as follows:

[0178]

[0179] The synthetic route of the compound is as follows:

[0180]

[0181] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by p-trifluoromethoxybromobenzene, and the final product Ⅰ-3-2 (5.0 g, yield 76%) is obtained, MS (m / z) (M+): 452.56.

[0182] Example 4

[0183] This embodiment provides a liquid crystal compound I-4-1, whose structural formula is as follows:

[0184]

[0185] The synthetic route of the compound is as follows:

[0186]

[0187] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by p-bromotoluene, and the final product Ⅰ-4-1 (6.0 g, yield 70%) is obtained, MS (m / z) (M+): 382.59.

[0188] Example 5

[0189] This embodiment provides a liquid crystal compound I-5-1, whose structural formula is as follows:

[0190]

[0191] The synthetic route of the compound is as follows:

[0192]

[0193] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by p-methoxybromobenzene, and the final product Ⅰ-5-1 (9 g, yield 90%) is obtained, MS (m / z) (M+): 398.59.

[0194] Example 6

[0195] This embodiment provides a liquid crystal compound I-6-1, whose structural formula is as follows:

[0196]

[0197] The synthetic route of the compound is as follows:

[0198]

[0199] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by p-bromophenylbutene, and methylpropanediol is replaced by pentenylpropanediol, and finally the product Ⅰ-6-1 (6.5 g, yield 70%) is obtained, MS (m / z) (M+): 422.65.

[0200] Example 7

[0201] This embodiment provides a liquid crystal compound I-7-1, whose structural formula is as follows:

[0202]

[0203] The synthetic route of the compound is as follows:

[0204]

[0205] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by 3,4-difluorobromobenzene, and methylpropylene glycol is replaced by ethylpropylene glycol, and finally the product Ⅰ-7-1 (7.2 g, yield 89%) is obtained, MS (m / z) (M+): 404.54.

[0206] Example 8

[0207] This embodiment provides a liquid crystal compound I-10-2, whose structural formula is as follows:

[0208]

[0209] The synthetic route of the compound is as follows:

[0210]

[0211] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by 3,4,5-trifluorobromobenzene, and the final product Ⅰ-10-2 (4.3 g, yield 71%) is obtained, MS (m / z) (M+): 422.53. The MS mass spectrum of liquid crystal compound Ⅰ-10-2 is shown as follows Figure 1 Shown

[0212] Example 9

[0213] This embodiment provides a liquid crystal compound I-11-1, whose structural formula is as follows:

[0214]

[0215] The synthetic route of the compound is as follows:

[0216]

[0217] The specific synthesis method is the same as that of compound Example 1, except that p-fluorobromobenzene is replaced by 3,5-difluoro-4-trifluoromethylbromobenzene, and the final product Ⅰ-11-1 (8.5 g, yield 87%) is obtained, MS (m / z) (M+): 472.54.

[0218] Comparative Example 1

[0219] This comparative example provides a liquid crystal compound D-1.

[0220]

[0221] Comparative Example 2

[0222] This comparative example provides a liquid crystal compound D-2.

[0223]

[0224] The monomer performance parameters are shown in Table 1:

[0225] Table 1 Monomer performance parameters

[0226]

[0227] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred composition examples. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0228] In the present invention, the preparation methods are conventional methods unless otherwise specified, the raw materials used can be obtained from public commercial channels unless otherwise specified, the percentages are all mass percentages, the temperature is degrees Celsius (°C), the liquid crystal compound is also called liquid crystal monomer, and the specific meanings of other symbols and test conditions are as follows:

[0229] Cp represents the clearing point of liquid crystal (℃), measured by DSC quantitative method;

[0230] SN represents the melting point of the liquid crystal from the crystalline state to the nematic phase (°C);

[0231] Δn represents optical anisotropy, Δn = n e -n o , where n o is the refractive index of ordinary light, n e It is the refractive index of extraordinary light, tested at 25±2℃, 589nm, and Abbe refractometer.

[0232] Δε represents dielectric anisotropy, Δε=ε ∥ -ε ⊥ , where ε ∥ is the dielectric constant parallel to the molecular axis, ε ⊥ is the dielectric constant perpendicular to the molecular axis, the test conditions are 25±0.5℃, 20 micron parallel box, INSTEC:ALCT-IR1 test;

[0233] VHR stands for voltage holding ratio (%), and the test conditions are 60±1℃, voltage ±5V, pulse width 10ms, and voltage holding time 1.667s. The test equipment is TOYO Model6254 LCD performance comprehensive tester;

[0234] K 11 is the splay elastic constant, K 33 is the bending elastic constant, K 22 is the torsional elastic constant, the test conditions are: 25±2℃, INSTEC:ALCT-IR1, 20μm vertical box; Kave=(K 11 +K 22+K 33 ) / 3

[0235] The preparation method of the liquid crystal composition is as follows: each liquid crystal monomer is weighed according to a certain ratio and put into a stainless steel beaker, and the stainless steel beaker containing each liquid crystal monomer is placed on a magnetic stirring instrument to heat and melt. After most of the liquid crystal monomers in the stainless steel beaker are melted, a magnetic rotor is added to the stainless steel beaker, and the mixture is stirred evenly. After cooling to room temperature, the liquid crystal composition is obtained.

[0236] The liquid crystal monomer structure of the embodiment of the present invention is represented by a code, and the code representation method of the liquid crystal ring structure, end group, and connecting group is shown in Table 2 and Table 3 below.

[0237] Table 2 Corresponding codes of ring structure

[0238]

[0239]

[0240] Table 3 Corresponding codes of terminal groups and linking groups

[0241]

[0242]

[0243] Example:

[0244] Its code is CC-Cp-V1; Its code is PGP-Cpr1-2;

[0245] Its code is CPY-2-O2; Its code is CCY-3-O2;

[0246] Its code is CLY-3-O2; Its code is PY-2O-O2;

[0247] Its code is CCEY-2-O2; Its code is CPP-3-2V1;

[0248] Its code is COY-3-O2; Its code is CCOY-3-O2;

[0249] Its code is Sb-CpO-O4; Its code is Sc-CpO-O4;

[0250] Its code is Sa-2O-O5; Its code is CPU-3-F;

[0251] Its code is CCP-V-OT; Its code is CPUQU-3-F;

[0252] Its code is APUQU-3-F; Its code is DPU-3-F;

[0253] Its code is DCLP-V2-F;

[0254] Its code is DCLG-2-T;

[0255] Its code is DCLU-3-F.

[0256] Composition 1

[0257] Table 4 Formulation of liquid crystal composition 1 and corresponding properties

[0258] category Liquid crystal monomer code content(%) Ⅲ APUQU-2-F 3 Ⅱ CC-3-2V1 3 Ⅱ CC-3-V 34 Ⅱ CC-3-V1 6 Ⅴ CCP-V-1 6 Ⅴ CCP-V2-1 9 Ⅵ CCVC-3-V 4 Ⅲ CDUQU-3-F 6 Ⅴ CLP-V-1 6 Ⅷ CLY-3-O2 4 Ⅱ CP-3-O2 1 Ⅴ CPP-1V-2 2 Ⅴ CPPC-3-3 2.5 Ⅲ PGUQU-3-F 2 Ⅱ PP-1-2V1 3.5 Ⅳ PPGU-Cp-F 0.5 Ⅲ PUQU-3-F 3.5 Ⅰ DCLU-3-F 4

[0259] Composition 2

[0260] Table 5 Formulation of liquid crystal composition 2 and corresponding properties

[0261]

[0262]

[0263] Composition 3

[0264] Table 6 Formulation of liquid crystal composition 3 and corresponding properties

[0265] category Liquid crystal monomer code content(%) Ⅱ CC-3-V 32 Ⅱ CC-3-V1 4 Ⅳ CCGU-3-F 3 Ⅴ CCP-V-1 14 Ⅴ CCP-V2-1 6 Ⅲ CCQU-3-F 5 Ⅳ CCU-3-F 4 Ⅲ CDUQU-3-F 2 Ⅴ CGPC-3-3 2 Ⅴ CLP-V-1 5 Ⅴ PGP-2-2V 2 Ⅴ PGPC-2-5 2 Ⅲ PGUQU-4-F 3 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 5.5 Ⅰ DCLU-3-F 6 Ⅰ DCLU-2-F 4

[0266] Composition 4

[0267] Table 7 Formulation of liquid crystal composition 4 and corresponding properties

[0268]

[0269]

[0270] Composition 5

[0271] Table 8 Formulation of liquid crystal composition 5 and corresponding properties

[0272] category Liquid crystal monomer code content(%) Ⅲ APUQU-3-F 4 Ⅱ CC-3-2V1 5 Ⅱ CC-3-V 30.5 Ⅱ CC-3-V1 4.5 Ⅳ CCGU-3-F 5 Ⅴ CCP-V-1 12 Ⅴ CCP-V2-1 5 Ⅵ CCVC-3-V 5 Ⅲ CDUQU-3-F 3 Ⅴ CLP-V-1 6 Ⅷ CLY-3-O2 3.5 Ⅲ PGUQU-3-F 3 Ⅱ PP-1-2V1 3.5 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 3 Ⅰ DCLU-3-F 6.5

[0273] Composition 6

[0274] Table 9 Formulation of liquid crystal composition 6 and corresponding properties

[0275]

[0276]

[0277] Composition 7

[0278] Table 10 Formulation of liquid crystal composition 7 and corresponding properties

[0279] category Liquid crystal monomer code content(%) Ⅱ CC-3-V 32 Ⅱ CC-3-V1 4 Ⅳ CCGU-3-F 3 Ⅴ CCP-V-1 14 Ⅴ CCP-V2-1 6 Ⅳ CCQU-3-F 5 Ⅳ CCU-3-F 4 Ⅲ CDUQU-3-F 2 Ⅴ CGPC-3-3 2 Ⅴ CLP-V-1 5 Ⅴ PGP-2-2V 2 Ⅴ PGPC-2-5 2 Ⅲ PGUQU-4-F 3 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 5.5 Ⅰ DCLU-3-T 6 Ⅰ DCLU-2-T 4

[0280] Composition 8

[0281] Table 11 Formulation of liquid crystal composition 8 and corresponding properties

[0282]

[0283]

[0284] Composition 9

[0285] Table 12 Formulation of liquid crystal composition 9 and corresponding properties

[0286] category Liquid crystal monomer code content(%) Ⅱ CC-3-V 37 Ⅱ CC-3-V1 5 Ⅲ APUQU-Cp-F 2.5 Ⅲ PGUQU-3-F 3.5 Ⅲ PUQU-Cpr1-F 4.5 Ⅲ CDUQU-3-F 5 Ⅳ CLP-3-T 5 Ⅳ CLP-3-OT 3.5 Ⅳ CCP-3-OT 7 Ⅴ CCP-V-1 10 Ⅴ CCP-V2-1 5.5 Ⅴ CPPC-3-3 4 Ⅷ CLY-3-O2 3 Ⅰ DCLU-3-F 4.5

[0287] Composition 10

[0288] Table 13 Formulation of liquid crystal composition 10 and corresponding properties

[0289]

[0290]

[0291] Composition 11

[0292] Table 14 Formulation of liquid crystal composition 11 and corresponding properties

[0293] category Liquid crystal monomer code content(%) Ⅱ CC-3-V 35.5 Ⅱ CC-3-V1 3 Ⅲ APUQU-Cp-F 3.5 Ⅲ PGUQU-3-F 3.5 Ⅲ PUQU-3-F 4.5 Ⅲ CDUQU-3-F 3 Ⅳ CLP-3-T 5 Ⅱ CP-3-O2 2 Ⅳ CCP-3-OT 3 Ⅴ CCP-V-1 9.5 Ⅴ CCP-V2-1 5.5 Ⅴ CPPC-3-3 1 Ⅷ CLY-3-O2 3 Ⅵ CCVC-3-V 3 Ⅴ CPP-1V-2 2 Ⅰ DCLU-3-F 6.5 Ⅰ DCLU-2-F 6.5

[0294] Composition 12

[0295] Table 15 Formulation of liquid crystal composition 12 and corresponding properties

[0296]

[0297]

[0298] Composition D1

[0299] Table 16 Formulation of liquid crystal composition D1 and corresponding properties

[0300] category Liquid crystal monomer code content(%) Ⅲ APUQU-3-F 3 Ⅱ CC-3-2V1 4 Ⅱ CC-3-V 28.5 Ⅱ CC-3-V1 5 Ⅳ CCGU-3-F 4 Ⅴ CCP-V-1 14 Ⅴ CCP-V2-1 5 Ⅵ CCVC-3-V 4 Ⅲ CDUQU-3-F 5 Ⅴ CLP-V-1 6 Ⅷ CLY-3-O2 4 Ⅲ PGUQU-3-F 2 Ⅱ PP-1-2V1 7 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 3 DLU-3-F 5

[0301] Composition D2

[0302] Table 17 Formulation of liquid crystal composition D2 and corresponding properties

[0303] category Liquid crystal monomer code content(%) Ⅲ APUQU-3-F 3 Ⅱ CC-3-2V1 4 Ⅱ CC-3-V 28.5 Ⅱ CC-3-V1 5 Ⅳ CCGU-3-F 4 Ⅴ CCP-V-1 14 Ⅴ CCP-V2-1 5 Ⅵ CCVC-3-V 4 Ⅲ CDUQU-3-F 5 Ⅴ CLP-V-1 6 Ⅷ CLY-3-O2 4 Ⅲ PGUQU-3-F 2 Ⅱ PP-1-2V1 7 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 3 DLU-1V-F 5

[0304] Composition D3

[0305] Table 18 Formulation of liquid crystal composition D3 and corresponding properties

[0306] category Liquid crystal monomer code content(%) Ⅲ APUQU-3-F 3 Ⅱ CC-3-2V1 4 Ⅱ CC-3-V 29.5 Ⅱ CC-3-V1 5 Ⅳ CCGU-3-F 4 Ⅴ CCP-V-1 15 Ⅴ CCP-V2-1 6 Ⅵ CCVC-3-V 4 Ⅲ CDUQU-3-F 5 Ⅴ CLP-V-1 6 Ⅷ CLY-3-O2 4 Ⅲ PGUQU-3-F 4 Ⅱ PP-1-2V1 7 Ⅳ PPGU-3-F 0.5 Ⅲ PUQU-3-F 3

[0307] Liquid crystal composition reliability

[0308] The reliability of the liquid crystal composition is tested by UV and high temperature aging tests and VHR tests. The smaller the change in VHR data of the liquid crystal composition before and after the UV and high temperature tests, the stronger the UV and high temperature resistance. Therefore, the UV and high temperature resistance are judged by comparing the difference in VHR data before and after the tests of each embodiment and comparative example.

[0309] The example liquid crystal and the comparative example liquid crystal were poured into the test piece for testing. VHR represents the voltage holding ratio (%). The test conditions are 60±1°C, voltage ±5V, pulse width 10ms, and voltage holding time 1.667s. The test equipment is TOYO Model 6254 liquid crystal performance comprehensive tester.

[0310] The initial value of VHR is the data obtained by testing the test piece filled with liquid crystal without any treatment;

[0311] VHR UV is the VHR value obtained by irradiating the film filled with liquid crystal under 5000mJ of UV light at room temperature;

[0312] VHR high temperature aging is the VHR value obtained by testing the liquid crystal filled film in a high temperature oven at 100°C for 24 hours.

[0313] Investigation of low temperature solubility of liquid crystal compositions

[0314] Compositions 1-12 and comparative compositions D1-D3 were placed in stainless steel beakers, respectively, and the stainless steel beakers were placed on a magnetic stirring instrument to heat and melt. After the liquid crystal monomers in the stainless steel beakers were melted, a magnetic rotor was added to the stainless steel beaker, and the mixture was stirred evenly. After cooling to room temperature, it was filtered with a 0.45um PTFE filter head, and then the prepared liquid crystal composition was transferred to a penicillin bottle (bulk), each bottle of liquid crystal was about 2 ml, and placed in a constant temperature glove box at -10°C, -20°C, and -30°C. The liquid crystal in the bulk bottle was observed every day for precipitation or smectic crystals, and the observation was continued for 30 days (30d). The later the crystallization time, the better the low-temperature solubility of the liquid crystal composition.

[0315] Scattering coefficient of liquid crystal composition

[0316] S LC ={(n e +n o ) 2 *△n 2} / K ave

[0317] Among them, S LC is the scattering coefficient of the liquid crystal layer, which characterizes the scattering intensity; the rest are parameters of the liquid crystal material.

[0318] The scattering coefficient is calculated based on compositions D2 and D3, and compositions D1 and compositions 1 to 12. The smaller the scattering coefficient, the higher the contrast. Generally, a 5% increase in the scattering coefficient has greatly improved the contrast. Currently, the scattering coefficients of compositions 1 to 12 have increased by more than 5%, so the contrast has improved significantly.

[0319] Table 19

[0320]

[0321]

[0322]

[0323] It can be seen from the background technology and the calculation formula that the smaller the scattering coefficient of the liquid crystal composition is, the better the contrast of the liquid crystal composition is. Moreover, the comparison of the scattering coefficient (contrast) should adopt the parallel comparison principle. Different liquid crystal compositions are used in different display modes and different technical fields, and the measured scattering coefficients are also different. The liquid crystal composition of the composition of the present invention is particularly suitable for vehicle-mounted liquid crystal displays or liquid crystal display elements.

[0324] From the above experimental data, it can be seen that the liquid crystal compound of the present invention has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature miscibility, a small optical anisotropy Δn, and a small scattering coefficient. The liquid crystal composition containing the liquid crystal compound of the present invention has a high elastic constant K, a high dielectric anisotropy Δε, a high clearing point Cp, good low-temperature miscibility, a small optical anisotropy Δn, and a small scattering coefficient. It can be used to develop a liquid crystal display element or liquid crystal display with faster response speed, high contrast, wider display temperature range, good low-temperature miscibility and good reliability, while effectively improving afterimages.

[0325] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A liquid crystal compound, characterized in that: The general structural formula of the compound is shown in Formula I. in, R represents an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and one or more H atoms in the alkyl group or alkenyl group are optionally substituted by halogen; and / or any one or more -CH2- in the alkyl group are each independently optionally substituted by -C≡C-, -CH=CH-, -S-, -CO-O- or -O-CO-substituted, and the O and S atoms in the substituent are not directly connected to each other; L1 and L2 are independently selected from H or F; X is selected from any one of F, Cl, CN, an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, a fluorinated alkyl group, a fluorinated alkenyl group, a fluorinated alkoxy group, and a fluorinated alkenyloxy group.

2. The liquid crystal compound according to claim 1, characterized in that The R is selected from one of a chain alkyl group having 1 to 10 carbon atoms, a chain alkyl group having 1 to 10 carbon atoms substituted with fluorine, an alkenyl group having 2 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms substituted with fluorine; and the X is selected from any one of F, CF3, or OCF3.

3. The liquid crystal compound according to claim 1 or 2, characterized in that The compound represented by formula I is selected from any one or any combination of the compounds represented by formulas I-1 to I-12 below, Here, R is selected from one of an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with fluorine, an alkenyl group having 2 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms substituted with fluorine.

4. The liquid crystal compound according to claim 3, characterized in that The compounds represented by formula I-1 to I-12 are selected from any one or any combination of the compounds represented by formula I-1-1 to I-12-1 below, 5. A liquid crystal composition, characterized in that: The liquid crystal composition comprises one or more liquid crystal compounds according to any one of claims 1 to 4.

6. The liquid crystal composition according to claim 5, characterized in that The liquid crystal composition further comprises one or more compounds represented by formula II, in, R1 and R2 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; Each independently expresses 7. The liquid crystal composition according to claim 5, characterized in that: The liquid crystal composition further comprises one or more compounds represented by formula III and formula IV, in, R3 and R4 each independently represent an alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms; and one or more non-adjacent -CH2- in R3 are optionally substituted by cyclopentylene or cyclopropylene; X1 and X3 each independently represent -H or -F; X2 represents -F, -CF3 or -OCF3; Each independently expresses m and n each independently represent 1, 2 or 3, and when m and n are 2 or 3, two or three Optional: same or different; b represents 0 or 1.

8. The liquid crystal composition according to claim 5, characterized in that The liquid crystal composition further comprises one or more compounds represented by formula V, in, R5 and R6 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; express r means 2 or 3; and two or three Optional same or different.

9. The liquid crystal composition according to claim 5, characterized in that: The liquid crystal composition further comprises one or more compounds represented by formula VI, in, R7 and R8 each independently represent an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; Z represents -C=C-, -CH2-CH2- or -CH2O-.

10. The liquid crystal composition according to claim 5, characterized in that: The liquid crystal composition further comprises one or more compounds represented by formula VII, in, R9, R 10 Each independently represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; a represents 0 or 1.

11. The liquid crystal composition according to claim 5, wherein The liquid crystal composition further comprises one or more compounds represented by formula VIII, in, R 11 , R 12 Each independently represents an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, or an alkoxy group having 1 to 15 carbon atoms; express 12. A liquid crystal display element or a liquid crystal display, characterized in that: The liquid crystal display device or liquid crystal display comprises the liquid crystal compound according to any one of claims 1 to 4 or the liquid crystal composition according to any one of claims 5 to 11, wherein the liquid crystal display device or liquid crystal display is an active matrix display device or display.

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