Liquid crystal composition and liquid crystal display component

Abstract

The invention relates to the technical field of liquid crystal materials, and particularly discloses a liquid crystal composition and a liquid crystal display component. The liquid crystal composition provided by the invention comprises a negative compound as shown in the formula I and a positive compound with dielectric anisotropy greater than 2, has proper refractive index anisotropy and dielectric anisotropy and higher transmittance, particularly has excellent low-temperature (-45 DEG C) storage performance and high and low-temperature change rate, can be used in a wider temperature range, and can be applied to the field of liquid crystal display devices. Compared with the prior art, the liquid crystal composition has the advantages that the liquid crystal composition can quickly respond even at a low temperature, meanwhile, the high-low temperature change rate of the liquid crystal composition is better improved through the synergistic effect of the compounds, the operating voltage change amplitude at a low temperature and the rotary viscosity change amplitude at a low temperature are reduced, and excellent reliability can be kept at a high temperature or under long-time illumination. The liquid crystal composition disclosed by the invention can be used for developing a wide-temperature liquid crystal display with high reliability and high transmittance, and is particularly suitable for displays in IPS, FFS, TN and ECB modes. I

Description

TECHNICAL FIELD

[0001] The present application relates to a novel liquid crystal composition, and a liquid crystal display using the same, especially suitable for IPS (in-plane switching), FFS (fringe field switching), TN (twisted nematic) and ECB (electrically controlled birefringence mode) mode displays. BACKGROUND

[0002] Liquid crystal displays (LCDs) are widely used in different aspects such as smart phones, computer displays, portable tablets, vehicle-mounted devices, televisions, etc. These applications require liquid crystal displays to have high contrast, wide viewing angle, fast response and high transmittance, etc. The LCD itself does not emit light and needs a backlight module to provide a light source, and the liquid crystal unit acts as a "light valve" to control the transmittance of the backlight by applying a voltage to change the arrangement of liquid crystal molecules. Low transmittance means loss of light energy, and in order to compensate for this loss to maintain the target performance, power consumption must be increased. Therefore, in the design of the optical system, improving the transmittance of the system is one of the most direct and effective ways to reduce power consumption.

[0003] Positive liquid crystals can achieve fast response when used for display and have good reliability, but the transmittance is relatively low; while negative liquid crystals can achieve higher transmittance when used for display, but the response time is slow due to the large viscosity of negative liquid crystals. The positive-negative hybrid liquid crystal, which is a positive liquid crystal mixture added with a negative component, has both the fast response advantage of positive liquid crystals and can effectively improve the transmittance, thereby greatly reducing the overall power consumption of the liquid crystal display device.

[0004] With the continuous expansion of the application of liquid crystal display in different display fields, the operating temperature of the liquid crystal display needs to meet the temperature range of -40°C to 95°C or even wider, so the liquid crystal composition composed of various monomers needs to have a wider temperature range of liquid crystal phase state, excellent mutual solubility at low temperature, and high clearing point, so as to maintain the liquid crystal phase in the widest possible temperature range and expand the working temperature range of the liquid crystal material. That is, the liquid crystal material can be used at extremely high or extremely low temperatures, which not only ensures that the liquid crystal composition can be stably placed at low temperature, but also ensures that the liquid crystal display can be effectively driven at low temperature, even at extremely low working temperature, the response time (especially the falling time) must be faster than the critical value (usually less than 300-500 ms, depending on the application) that can be perceived by the human eye, to ensure basic dynamic display capability.

[0005] In liquid crystal compositions, the rotation speed of liquid crystal molecules (i.e. response time) is inversely proportional to the rotational viscosity. The higher the rotational viscosity, the slower the molecules rotate, and the slower the response time; conversely, the lower the rotational viscosity, the faster the molecules rotate, and the faster the response time. Therefore, in order to obtain fast response (especially in scenarios such as games, dynamic videos, etc.), the rotational viscosity of the liquid crystal material itself should be as low as possible. Some liquid crystal displays require suitable for extreme conditions, such as vehicle-mounted displays, outdoor displays, etc., and require liquid crystal compositions to have good performance, especially in low-temperature environments. However, the rotational viscosity of most existing liquid crystal compounds or liquid crystal compositions increases sharply when the temperature decreases, and the increase in rotational viscosity directly affects the response time of the liquid crystal display. A screen with a response time of 20 ms at room temperature may be extended to tens or even hundreds of milliseconds at 0°C or -20°C, resulting in serious ghosting, residual image, and blurred picture; under extremely low temperature conditions, the liquid crystal may exhibit a smectic phase or crystallization, and the screen may not display normally (almost impossible to watch dynamic content normally) even if a driving voltage is applied, and it needs a long time to preheat to work. Therefore, for high-performance liquid crystal compounds or compositions, especially in wide-temperature application scenarios such as vehicle-mounted displays, outdoor industrial displays, mobile devices used in cold regions, etc., there are higher requirements for low-temperature storage and low-temperature fast response, and liquid crystal materials need to have a wider range of display temperatures, faster response time at low use temperature, and normal display at high temperature environment. This requires the liquid crystal composition to exhibit excellent display performance at high temperature environment and to maintain stable performance under long-term light exposure and other environments, and to have good reliability to heat and ultraviolet light.

[0006] Therefore, how to develop a liquid crystal composition that balances good low-temperature performance and good reliability is a problem to be solved at present. SUMMARY

[0007] To solve the above problems, the present application provides a liquid crystal composition and a liquid crystal display component, which has good low-temperature (-45°C) storage performance and high low-temperature change rate, can be used in a wider temperature range, can respond quickly even at a lower temperature, and can maintain excellent reliability at a higher temperature or under long-term light exposure. The liquid crystal composition of the present application can be used to develop a wide-temperature liquid crystal display with high reliability and high transmittance, and can be used in displays such as vehicle-mounted displays and outdoor displays.

[0008] In one aspect, the present application provides a liquid crystal composition comprising a negative compound having a structural formula as shown in Formula I and a positive compound having a dielectric anisotropy greater than 2, I wherein, R1 represents an alkyl group with 1-10 carbon atoms, an alkoxy group with 1-10 carbon atoms, an alkenyl group with 2-10 carbon atoms, or an alkenyloxy group with 2-10 carbon atoms, wherein one or more non-adjacent -CH2- groups can be independently separated by -C≡C-, -CH=CH-, -CF2O-, -OCF2-, -O-, -CO-O-, -O-CO-, , , , , or The O atoms can be replaced in such a way that they are not connected to each other, and / or one or more of the hydrogen atoms can also be replaced by halogens; Z represents a single bond, -CH2O-, or -CH2CH2-; R2 indicates an alkyl chain with 1-10 carbon atoms; R3 represents H or an alkyl chain with 1-10 carbon atoms; m and c each independently represent 0 or 1; n represents an integer from 0 to 10; X represents -O- or -S-.

[0009] In another aspect, the present invention provides a liquid crystal display element comprising the liquid crystal composition described above, wherein the liquid crystal display element comprises an active matrix display element or a passive matrix display element.

[0010] In another aspect, the present invention provides a liquid crystal display comprising the liquid crystal composition described above, wherein the liquid crystal display includes an active matrix display or a passive matrix display.

[0011] The beneficial effects of this invention are as follows: The liquid crystal composition provided by this invention possesses suitable refractive index anisotropy, dielectric anisotropy, and high transmittance. Furthermore, the liquid crystal composition of this invention exhibits particularly good low-temperature miscibility, good low-temperature response speed, and good high and low temperature change rate and reliability. The liquid crystal composition of this invention comprises a negative compound represented by Formula I. The structure of this compound itself gives it better high and low temperature change rate (reduced rate of change of operating voltage and reduced rate of change of rotational viscosity). Simultaneously, its advantage in low-temperature storage allows for the addition of more other compounds with good high and low temperature change rates to the overall formulation (i.e., the liquid crystal composition). Through the synergistic effect of these compounds, the high and low temperature change rate of the liquid crystal composition is further improved, reducing the amplitude of operating voltage changes and rotational viscosity changes at low temperatures, thereby improving the low-temperature response time. The liquid crystal composition of this invention can be used to develop wide-temperature liquid crystal displays with high reliability and high transmittance, especially for automotive and outdoor displays. Detailed Implementation

[0012] The liquid crystal composition of the present invention preferably comprises a liquid crystal compound selected from compounds of formula I and one or more compounds with a dielectric anisotropy greater than 2. Ⅰ in, R1 represents an alkyl group with 1-10 carbon atoms, an alkoxy group with 1-10 carbon atoms, an alkenyl group with 2-10 carbon atoms, or an alkenyloxy group with 2-10 carbon atoms, wherein one or more non-adjacent -CH2- groups can be independently separated by -C≡C-, -CH=CH-, -CF2O-, -OCF2-, -O-, -CO-O-, -O-CO-, , , , , or The O atoms can be replaced in such a way that they are not connected to each other, and / or one or more of the hydrogen atoms can also be replaced by halogens; Z represents a single bond, -CH2O-, or -CH2CH2-; R2 indicates an alkyl chain with 1-10 carbon atoms; R3 represents H or an alkyl chain with 1-10 carbon atoms; m and c each independently represent 0 or 1; n represents an integer from 0 to 10; X represents -O- or -S-.

[0013] Preferably, in the liquid crystal composition of the present invention, the compound represented by Formula I is selected from the group consisting of compounds of Formulas I-1 to I-3 below. Ⅰ-1 Ⅰ-2 Ⅰ-3.

[0014] In the liquid crystal composition of the present invention, preferably, in the negative compound shown in Formula I above, R1 represents an alkyl group having 1-10 carbon atoms, an alkoxy group having 1-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkenyloxy group having 2-10 carbon atoms; X represents -S-.

[0015] Preferably, the liquid crystal compound of the present invention comprises a negative compound represented by Formula I-1 selected from Formulas I-1-1 to I-1-4. Ⅰ-1-1 Ⅰ-1-2 Ⅰ-1-3 Ⅰ-1-4.

[0016] Preferably, the liquid crystal compound of the present invention comprises a negative compound represented by Formula I-2 selected from Formulas I-2-1 to I-2-100. Ⅰ-2-1 Ⅰ-2-2 Ⅰ-2-3 Ⅰ-2-4 Ⅰ-2-5 Ⅰ-2-6 Ⅰ-2-7 Ⅰ-2-8 Ⅰ-2-9 Ⅰ-2-10 Ⅰ-2-11 Ⅰ-2-12 Ⅰ-2-13 Ⅰ-2-14 Ⅰ-2-15 Ⅰ-2-16 Ⅰ-2-17 Ⅰ-2-18 Ⅰ-2-19 Ⅰ-2-20 Ⅰ-2-21 Ⅰ-2-22 Ⅰ-2-23 Ⅰ-2-24 Ⅰ-2-25 Ⅰ-2-26 Ⅰ-2-27 Ⅰ-2-28 Ⅰ-2-29 Ⅰ-2-30 Ⅰ-2-31 Ⅰ-2-32 Ⅰ-2-33 Ⅰ-2-34 Ⅰ-2-35 Ⅰ-2-36 Ⅰ-2-37 Ⅰ-2-38 Ⅰ-2-39 Ⅰ-2-40 Ⅰ-2-41 Ⅰ-2-42 Ⅰ-2-43 Ⅰ-2-44 Ⅰ-2-45 Ⅰ-2-46 Ⅰ-2-47 Ⅰ-2-48 Ⅰ-2-49 Ⅰ-2-50 Ⅰ-2-51 Ⅰ-2-52 Ⅰ-2-53 Ⅰ-2-54 Ⅰ-2-55 Ⅰ-2-56 Ⅰ-2-57 Ⅰ-2-58 Ⅰ-2-59 Ⅰ-2-60 Ⅰ-2-61 Ⅰ-2-62 Ⅰ-2-63 Ⅰ-2-64 Ⅰ-2-65 Ⅰ-2-66 Ⅰ-2-67 Ⅰ-2-68 Ⅰ-2-69 Ⅰ-2-70 Ⅰ-2-71 Ⅰ-2-72 Ⅰ-2-73 Ⅰ-2-74 Ⅰ-2-75 Ⅰ-2-76 Ⅰ-2-77 Ⅰ-2-78 Ⅰ-2-79 Ⅰ-2-80 Ⅰ-2-81 Ⅰ-2-82 Ⅰ-2-83 Ⅰ-2-84 Ⅰ-2-85 Ⅰ-2-86 Ⅰ-2-87 Ⅰ-2-88 Ⅰ-2-89 Ⅰ-2-90 Ⅰ-2-91 Ⅰ-2-92 Ⅰ-2-93 Ⅰ-2-94 Ⅰ-2-95 Ⅰ-2-96 Ⅰ-2-97 Ⅰ-2-98 Ⅰ-2-99 Ⅰ-2-100.

[0017] Preferably, the liquid crystal compound of the present invention comprises a negative compound represented by Formula I-3 selected from Formulas I-3-1 to I-3-7. Ⅰ-3-1 Ⅰ-3-2 Ⅰ-3-3 Ⅰ-3-4 Ⅰ-3-5 Ⅰ-3-6 Ⅰ-3-7.

[0018] In the liquid crystal composition of the present invention, preferably, the aforementioned positive compound with a dielectric anisotropy greater than 2 is selected from the group consisting of compounds shown in Formula II and / or Formula III below. II III in, R4 and R5 each independently represent an alkyl group, an alkenyl group, or an alkoxy group with up to 15 carbon atoms, wherein one or more non-adjacent -CH2- groups can be independently converted to -C≡C-, -CH=CH-, -CF2O-, -OCF2-, -O-, -CO-O-, -O-CO-, or -C≡C-. , , , , or Replace them by ensuring that the O atoms are not connected to each other; a1 represents 1, 2, or 3; b1 represents 2, 3, or 4; X1 represents -F, -CF3, or -OCF3; X2 represents -H or -CH3; , , Each represents independently , , , , , , or When a1 represents 2 or 3, They are independently the same or different; when b1 represents 2, 3 or 4, They are either the same or different independently.

[0019] Preferably, in the liquid crystal composition of the present invention, the compound represented by Formula II is selected from the group consisting of compounds represented by Formulas II-1 to II-25 below. II-1 II-2 II-3 II-4 II-5 II-6 II-7 II-8 II-9 II-10 II-11 II-12 II-13 II-14 II-15 II-16 II-17 II-18 II-19 II-20 II-21 II-22 II-23 II-24 II-25.

[0020] Preferably, in the liquid crystal composition of the present invention, the positive compound shown in II is selected from at least one of the compounds shown in formulas II-2, II-16, II-20, II-19, and II-24.

[0021] Preferably, in the liquid crystal composition of the present invention, the compound represented by Formula III is selected from the group consisting of compounds represented by Formulas III-1 to III-18 below. Ⅲ-1 Ⅲ-2 Ⅲ-3 Ⅲ-4 Ⅲ-5 Ⅲ-6 Ⅲ-7 Ⅲ-8 Ⅲ-9 Ⅲ-10 Ⅲ-11 Ⅲ-12 Ⅲ-13 Ⅲ-14 Ⅲ-15 Ⅲ-16 Ⅲ-17 Ⅲ-18.

[0022] Preferably, in the liquid crystal composition of the present invention, the compound shown in III is selected from the group consisting of compounds shown in formulas III-1, III-2, III-3, III-5, III-7, and III-10.

[0023] Preferably, the liquid crystal composition of the present invention comprises one or more compounds of formula IV. IV in, R6 and R7 each independently represent an alkyl group, an alkenyl group, or an alkoxy group with a maximum of 15 carbon atoms; c1 and c2 each represent 1 or 2 independently; Z1 represents a single bond, -CH2-CH2-, -CH=CH-, -CF2O-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, or -CF=CF-; , Each represents independently , , , , When d or e represents 2, , They are either the same or different independently.

[0024] Preferably, in the liquid crystal composition of the present invention, the compound represented by Formula IV is selected from the group consisting of compounds represented by Formulas IV-1 to IV-14 below. IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 IV-7 IV-8 IV-9 IV-10 IV-11 IV-12 IV-13 IV-14.

[0025] Preferably, in the liquid crystal composition of the present invention, the compound shown in N is selected from the group consisting of compounds shown in formulas IV-1, IV-2, IV-4, IV-5, IV-7, and IV-10.

[0026] Preferably, the liquid crystal composition of the present invention comprises one or more compounds of formula V. V And / or, one or more compounds of formula VI, VI in, R8 and R9 each independently represent an alkyl group having 1-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms, wherein one or more unconnected -CH2- groups are optionally substituted with cyclopropyl, cyclopentyl, or cyclobutyl groups. , , and Each represents independently , , , , or ; X3 and X5 each independently represent -H, -F, alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms; X4 and X6 each independently represent -H, -F, alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms, wherein one or more hydrogen atoms may be replaced by fluorine atoms; W1 and W2 each independently represent -O- or -S-.

[0027] In the liquid crystal composition of the present invention, preferably, R8 and R9 in the compounds shown in the aforementioned formulas V and VI independently represent an alkyl group, an alkenyl group, or an alkoxy group having 2-5 carbon atoms.

[0028] In the liquid crystal composition of the present invention, preferably, in the compounds shown in formulas V and VI above, X3, X4, X5, and X6 each independently represent -H, -F, an alkyl group having 1-4 carbon atoms, an alkoxy group having 1-4 carbon atoms, or an alkenyl group having 1-4 carbon atoms.

[0029] Preferably, in the liquid crystal composition of the present invention, the compound represented by formula V is selected from the group consisting of compounds represented by formulas V-1 to V-12 below. V-1 V-2 V-3 V-4 V-5 V-6 V-7 V-8 V-9 V-10 V-11 V-12.

[0030] Preferably, in the liquid crystal composition of the present invention, the compound represented by formula VI is selected from the group consisting of compounds represented by formulas VI-1 to VI-4. VI-1 VI-2 VI-3 VI-4.

[0031] Preferably, in the liquid crystal composition of the present invention, the compound shown in Formula V includes the compound shown in Formula V-2; and the compound shown in Formula VI includes the compound shown in Formula VI-1.

[0032] Preferably, the liquid crystal composition of the present invention comprises one or more compounds of formula VII. VII in, R 10 R 11 Each of the following can independently represent an alkyl group having 1-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms, wherein one or more unconnected -CH2- groups are optionally substituted with cyclopropyl, cyclopentyl, or cyclobutyl groups. Z2 represents a single bond, -CH2-CH2-, -CH=CH-, -CF2O-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, or -CF=CF-; express , , , or ; d1 represents 0, 1, 2, or 3; when d1 represents 2 or 3, They are either the same or different independently; d2 represents 0 or 1.

[0033] Preferably, in the liquid crystal composition of the present invention, the compound represented by formula VII is selected from the group consisting of compounds of formulas VII-1 to VII-16. VII-1 VII-2 VII-3 VII-4 VII-5 VII-6 VII-7 VII-8 VII-9 VII-10 VII-11 VII-12 VII-13 VII-14 VII-15 VII-16.

[0034] Preferably, in the liquid crystal composition of the present invention, the compound represented by Formula VII is selected from at least one of the compounds represented by Formulas VII-2, VII-3, VII-7, VII-8, VII-9, and VII-10.

[0035] In the liquid crystal composition of the present invention, preferably, the negative compound represented by Formula I has a mass percentage content of 0.1%-30%, more preferably 0.1%-25%, and even more preferably 2%-10%.

[0036] The liquid crystal composition of the present invention preferably has a mass percentage content of 0-30% for the compound represented by Formula II, more preferably 1%-30%, and even more preferably 1%-20%.

[0037] The liquid crystal composition of the present invention preferably has a mass percentage content of 0-30% for the compound represented by Formula III, more preferably 1%-30%, and even more preferably 7%-25%.

[0038] The liquid crystal composition of the present invention preferably has a mass percentage content of 15%-80% of the compound shown in Formula IV, more preferably 20%-80%, and even more preferably 45%-80%.

[0039] The liquid crystal composition of the present invention preferably has a mass percentage content of 0-20% for the compound represented by Formula V, more preferably 0-7%, and even more preferably 1%-6%.

[0040] The liquid crystal composition of the present invention preferably has a mass percentage content of 0-20% for the compound represented by Formula VI, more preferably 0-7%, and even more preferably 2%-7%.

[0041] The liquid crystal composition of the present invention preferably has a mass percentage content of 0-20% for the compound represented by Formula VII, more preferably 1%-8%, and even more preferably 2%-7%.

[0042] Preferably, the liquid crystal composition of the present invention further comprises one or more additives.

[0043] In the liquid crystal composition of the present invention, preferably, the additive has a mass percentage content of 0.0001%-2%, more preferably 0.01%-1.5%, and even more preferably 0.012%-1%.

[0044] In the liquid crystal composition of the present invention, preferably, the aforementioned additives include at least one of antioxidants or light stabilizers.

[0045] In the liquid crystal composition of the present invention, preferably, the aforementioned additives are selected from the group consisting of compounds of formulas T-1 to T-16.

[0046]

[0047] .

[0048] In this invention, "alkyl" or "alkyl" refers to a straight-chain or branched alkyl group, preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, etc.

[0049] In this invention, "alkenyl" or "alkenyl" refers to a straight-chain or branched alkenyl group, preferably vinyl, propenyl, propenyl, butenyl, butenyl, butenyl, pent-1-alkenyl, pent-2-alkenyl, pent-3-alkenyl, pent-4-alkenyl, hex-1-alkenyl, hex-2-alkenyl, hex-3-alkenyl, hex-4-alkenyl, hex-5-alkenyl, or hept-1-alkenyl, hept-2-alkenyl, hept-3-alkenyl, hept-4-alkenyl, hept-5-alkenyl, hept-6-alkenyl, etc.

[0050] In this invention, "alkoxy" or "alkoxy" refers to straight-chain or branched-chain alkoxy groups, preferably methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, etc.

[0051] In this invention, "alkenyloxy" or "alkenyloxy" refers to straight-chain or branched alkenyloxy, preferably 2-propenyloxy, 2-butenyloxy, 2-pentenyloxy, etc.

[0052] It should be noted that the present invention does not impose any special limitations on the synthesis methods of the compounds shown in Formulas I to VII, and conventional preparation methods in the art can be used.

[0053] The preparation method of the liquid crystal composition includes the following steps: weigh each liquid crystal monomer (i.e. each compound) according to a certain ratio and put them into a stainless steel beaker. Place the stainless steel beaker containing each liquid crystal monomer on a magnetic stirrer and heat it to melt. After most of the liquid crystal monomer in the stainless steel beaker has melted, add a magnetic rotor to the stainless steel beaker and stir the mixture evenly. After cooling to room temperature, the liquid crystal composition is obtained.

[0054] According to another specific embodiment of the present invention, a liquid crystal display element is provided, the liquid crystal display element comprising the liquid crystal composition or liquid crystal compound as described above. The liquid crystal display element includes an active matrix display element or a passive matrix display element.

[0055] Preferably, the liquid crystal display element is an active matrix addressing liquid crystal display element.

[0056] The active matrix display element includes, but is not limited to, TN-TFT, IPS-TFT, or FFS-TFT liquid crystal display elements, especially FFS-TFT mode liquid crystal display elements for applications such as automotive, NB / TV, and MNT.

[0057] According to another specific embodiment of the present invention, a liquid crystal display is provided, the liquid crystal display comprising the liquid crystal composition or liquid crystal compound as described above. The liquid crystal display includes an active matrix display or a passive matrix display.

[0058] Preferably, the liquid crystal display is an active matrix addressing liquid crystal display.

[0059] The active matrix display includes, but is not limited to, TN-TFT, IPS-TFT, or FFS-TFT liquid crystal displays or other TFT displays, especially suitable for FFS-TFT mode liquid crystal displays for applications such as automotive, NB / TV, and MNT.

[0060] The liquid crystal composition provided by this invention can be used to develop wide-temperature liquid crystal displays with high reliability and high transmittance. It can be used for automotive displays, outdoor displays, etc., and is especially suitable for displays in IPS (coplanar switching), FFS (edge ​​field switching), TN (twisted nematic) and ECB (electronically controlled birefringence) modes.

[0061] Example To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0062] In this invention, the preparation methods are all conventional unless otherwise specified, and the raw materials used can be obtained from publicly available commercial sources unless otherwise specified. The reaction process is generally monitored by TLC. The post-reaction treatment generally includes water washing, extraction, drying after combining organic phases, solvent removal under reduced pressure, recrystallization, and column chromatography. Those skilled in the art can implement this invention according to the following description.

[0063] All percentages in this instruction manual refer to mass percentages, and temperatures are in degrees Celsius (°C). The specific meanings of other symbols and test conditions are as follows: Tni represents the liquid crystal clearing point (°C), measured by DSC quantitative method; Δn represents optical anisotropy, Δn = n e -n o , where n o Let n be the refractive index of ordinary light. e The refractive index of unusual light was measured at 25±2℃, 589nm, using an Abbe refractometer. Δε represents dielectric anisotropy, Δε = ε ∥ -ε ⊥ , where ε ∥ ε is the dielectric constant parallel to the molecular axis. ⊥ The dielectric constant is perpendicular to the molecular axis. The test conditions are 25±0.5℃, 20-micron vertical / parallel cell, and INSTEC:ALCT-IR1 test. d (μm) represents the thickness of the liquid crystal cell; Low temperature experiment: Liquid crystal was filled into the corresponding mode cell and placed in constant temperature chambers at -45℃ and -25℃ respectively. The cells were observed every 24 hours to see if there was any smectic phase or crystal precipitation. No smectic phase or crystal precipitation was marked as OK, and smectic phase or crystal precipitation was marked as NG. The low temperature storage time was recorded based on this. RT represents the response time (ms). The testing instrument is DMS-505, and the testing conditions are 25±0.5℃, 5±0.5℃, 0±0.5℃, and -30±0.5℃. The test box is a micron FFS test box with a diameter of 2.6~3.6.

[0064] ΔRT represents the absolute value of the difference between 5℃RT and 25℃RT, or the absolute value of the difference between 25℃RT and -30℃RT.

[0065] In the embodiments and comparative examples of this invention, the liquid crystal monomer structure is represented by code, and the code representation methods for liquid crystal ring structure, end groups, and linking groups are shown in Tables 1 and 2.

[0066] Table 1. Corresponding codes for ring structures

[0067] Table 2. Correspondence codes between terminal groups and linking groups

[0068] For example: Its code is CC-Cp-V1; Its code is PGP-Cpr1-2; Its code is CPY-2-O2; Its code is CCY-3-O2; Its code is COY-3-O2; Its code is CCOY-3-O2; Its code is Sb-CpO-O4; Its code is Sc-CpO-O4 Its code is PP-5-3; Its code is CY-3-O2; Its code is PGU-3-F; Its code is PGUQU-3-F; Its code is CPUQU-3-F.

[0069] Comparative compounds D1 D2 D3 D4 D5 D6 The negative compound with the structural formula shown in Formula I in this invention can be synthesized via the following synthetic route: Route 1:

[0070] Route 2:

[0071] Intermediates SM-1 and SM-2 were prepared according to existing technology, and then etherified. Through the above-mentioned route one, negative compounds of formula I-1 and I-2 can be obtained; through the above-mentioned route two, negative compounds of formula I-3 can be obtained.

[0072] Synthesis example 1 The preparation route of the compound shown in Formula I-2-14 is as follows:

[0073] 28.3 g of 7-ethoxy-4,6-difluorobenzothiophene-3-ol, 10.3 g of 3-methyl-3-buten-1-ol, 31.4 g of triphenylphosphine, and 180 mL of tetrahydrofuran were added to a three-necked flask. Under nitrogen protection, the mixture was cooled to -10 °C in an ice-salt bath. 24.2 g of diisopropyl azodicarbonate was dissolved in 50 mL of tetrahydrofuran and slowly added dropwise to the three-necked flask. After the addition was complete, the mixture was allowed to warm to room temperature and stirred at room temperature for 2 h. After the reaction was complete, 200 mL of water was added and stirred. The mixture was separated, extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness. It was recrystallized twice with 1 part toluene and 2 parts ethanol, and once with 2 parts petroleum ether and 1 part ethanol to obtain 25.4 g of the compound shown in Formula I-2-14, a white solid with GC: 99.78%.

[0074] By referring to the preparation method of the compound shown in Formula I-2-14 and making simple substitutions of raw materials, the following compounds can be prepared: I-2-1, I-2-2, I-2-3, I-2-4, I-2-11, I-2-13, I-2-14, I-2-15, I-2-17, I-2-29, I-2-31, I-2-32, I-2-33, I-2-35, I-2-40, I-2-41, I-2-42, I-2-44.

[0075] Synthesis example 2 The preparation route of the compound shown in Formula I-3-1 is as follows:

[0076] Step 1: 23.6 g of SM-2, 17.1 g of trans-4-ethyl-cyclohexylmethanol, 31.4 g of triphenylphosphine, and 150 mL of tetrahydrofuran were added to a three-necked flask. Under nitrogen protection, the mixture was cooled to -10 °C in an ice-salt bath. 24.2 g of diisopropyl azodicarbonate was dissolved in 50 mL of tetrahydrofuran and slowly added dropwise to the three-necked flask. After the addition was complete, the mixture was allowed to warm to room temperature and stirred at room temperature for 2 h. After the reaction was complete, 200 mL of water was added and stirred. The mixture was separated, extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness. The mixture was recrystallized twice with 2 parts ethanol and 1 part petroleum ether to obtain 24.9 g of compound SM-3, a white solid with GC: 99.82%.

[0077] Step Two: 24.9 g of SM-3 was added to a three-necked flask, followed by 100 mL of tetrahydrofuran for dissolution. The mixture was then cooled to -78 °C under nitrogen protection, and 33 mL of n-BuLi (2.5 M cyclohexane solution) was added dropwise at -78 °C. The resulting mixture was stirred at -78 °C for 1 h, and then 8.6 g of trimethyl borate in tetrahydrofuran solution was added at the same temperature. The mixture was kept at -78 °C for 1 h, and then the reaction mixture was warmed to room temperature. A mixture of 10.6 mL of acetic acid and 13.3 mL of water was added, followed by slow dropwise addition of 15.7 mL of 30% hydrogen peroxide. The mixture was stirred at room temperature for 4 h. After the reaction was complete, water and ethyl acetate were added, and the mixture was stirred and separated. The aqueous phase was extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and the solvent was evaporated. The mixture was recrystallized twice with 3 parts petroleum ether and 0.5 parts ethanol to give 15.9 g of compound SM-4, a white solid with GC: 98.3%.

[0078] Step 3: 15.9 g of SM-4, 4.3 g of 3-methyl-3-buten-1-ol, 13.1 g of triphenylphosphine, and 100 mL of tetrahydrofuran were added to a three-necked flask. Under nitrogen protection, the mixture was cooled to -10 °C in an ice-salt bath. 10.1 g of diisopropyl azodicarbonate was dissolved in 20 mL of tetrahydrofuran and slowly added dropwise to the three-necked flask. After the addition was complete, the mixture was allowed to warm to room temperature and stirred at room temperature for 2 h. After the reaction was complete, 100 mL of water was added and stirred. The mixture was separated, extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness. The mixture was recrystallized twice with 2 parts toluene and 1 part ethanol to obtain 11.1 g of the compound shown in Formula I-3-1, a white solid with GC: 99.56%.

[0079] By referring to the preparation method of the compound shown in Formula I-3-1 and making simple substitutions of raw materials, the following compounds can be prepared: I-3-2, I-3-4, I-3-6, I-2-50, I-2-59, I-2-68, I-2-77, and I-2-95.

[0080] Synthesis example 3 The preparation route of the compound shown in Formula I-1-1 is as follows:

[0081] 13.2 g of 7-ethoxy-4,6-difluorobenzofuran-3-ol, 5.7 g of 3-methyl-3-buten-1-ol, 15.7 g of triphenylphosphine, and 100 mL of tetrahydrofuran were added to a three-necked flask. Under nitrogen protection, the mixture was cooled to -10 °C in an ice-salt bath. 12.1 g of diisopropyl azodicarbonate was dissolved in 20 mL of tetrahydrofuran and slowly added dropwise to the three-necked flask. After the addition was complete, the mixture was allowed to warm to room temperature and stirred at room temperature for 2 h. After the reaction was complete, 150 mL of water was added and stirred. The mixture was separated, extracted with ethyl acetate, washed with water, dried over anhydrous sodium sulfate, and evaporated to dryness. It was recrystallized twice with 1 part petroleum ether and 2 parts ethanol, and once with 2 parts petroleum ether and 1 part ethanol to give 12.2 g of the compound shown in Formula I-1-1, a white solid with GC: 99.91%.

[0082] By referring to the preparation method of the compound shown in Formula I-1-1, and by making simple substitutions of raw materials, the following compounds can be prepared: I-1-2, I-1-3, and I-1-4.

[0083] Example 1 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 3.

[0084] Table 3. Formulation composition and performance parameters of Example 1

[0085] Example 2 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 4.

[0086] Comparative Example 1 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 4.

[0087] Table 4. Formulation composition and performance parameters of Example 2 and Comparative Example 1

[0088] Example 3 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 5.

[0089] Table 5. Formulation composition and performance parameters of Example 3

[0090] Example 4 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 6.

[0091] Comparative Example 2 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 6.

[0092] Table 6. Formulation composition and performance parameters of Example 4 and Comparative Example 2

[0093] Example 5 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 7.

[0094] Table 7. Formulation composition and performance parameters of Example 5

[0095] Example 6 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 8.

[0096] Table 8. Formulation composition and performance parameters of Example 6

[0097] Example 7 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 9.

[0098] Comparative Example 3 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 9.

[0099] Table 9. Formulation composition and performance parameters of Example 7 and Comparative Example 3

[0100] Example 8 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 10.

[0101] Table 10 Formulation composition and performance parameters of Example 8

[0102] Example 9 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 11.

[0103] Comparative Example 4 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 11.

[0104] Table 11 Formulation composition and performance parameters of Example 9 and Comparative Example 4

[0105] Example 10 This embodiment provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 12.

[0106] Comparative Example 5 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 12.

[0107] Table 12 Formulation composition and performance parameters of Example 10 and Comparative Example 5

[0108] Example 11 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 13.

[0109] Comparative Example 6 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 13.

[0110] Table 13 Formulation composition and performance parameters of Example 11 and Comparative Example 6

[0111] Example 12 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 14.

[0112] Comparative Example 7 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 14.

[0113] Table 14 Formulation composition and performance parameters of Example 12 and Comparative Example 7

[0114] Example 13 This embodiment provides a liquid crystal composition, the composition, ratio and corresponding performance parameters of which are shown in Table 15.

[0115] Comparative Example 8 This comparative example provides a liquid crystal composition, the composition, proportions and corresponding performance parameters of which are shown in Table 15.

[0116] Table 15 Formulation composition and performance parameters of Example 13 and Comparative Example 8

[0117] The liquid crystal composition provided by this invention possesses suitable refractive index anisotropy, dielectric anisotropy, and high transmittance. Furthermore, the liquid crystal composition of this invention exhibits particularly good low-temperature miscibility, good low-temperature response speed, and good high and low temperature viscosity variation rate and reliability. The liquid crystal composition of this invention comprises a negative compound represented by Formula I. The structure of this compound itself gives it better high and low temperature viscosity variation rate (reduced rate of change of operating voltage and reduced rate of change of rotational viscosity). Simultaneously, its advantage in low-temperature storage allows for the addition of more compounds with good high and low temperature viscosity variation rates to the overall formulation, which work together to further improve the high and low temperature viscosity variation rate of the liquid crystal composition, reduce the amplitude of operating voltage changes at low temperatures, and also reduce the amplitude of rotational viscosity changes at low temperatures, thereby improving the low-temperature response time. The liquid crystal composition of this invention can be used to develop wide-temperature liquid crystal displays with high reliability and high transmittance, especially for automotive and outdoor displays.

[0118] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A liquid crystal composition, characterized in that, The liquid crystal composition comprises a negative compound with the structural formula shown in Formula I and a positive compound with a dielectric anisotropy greater than 2. Ⅰ in, R1 represents an alkyl group with 1-10 carbon atoms, an alkoxy group with 1-10 carbon atoms, an alkenyl group with 2-10 carbon atoms, or an alkenyloxy group with 2-10 carbon atoms, wherein one or more non-adjacent -CH2- groups can be independently separated by -C≡C-, -CH=CH-, -CF2O-, -OCF2-, -O-, -CO-O-, -O-CO-, , , , , or The O atoms are replaced in such a way that they are not connected to each other, and / or one or more of the hydrogen atoms can be replaced by halogens; Z represents a single bond, -CH2O-, or -CH2CH2-; R2 indicates an alkyl chain with 1-10 carbon atoms; R3 represents H or an alkyl chain with 1-10 carbon atoms; m and c each independently represent 0 or 1; n represents an integer from 0 to 10; X represents -O- or -S-.

2. The liquid crystal composition according to claim 1, characterized in that, The negative compounds with the structural formula shown in Formula I are selected from the group consisting of compounds shown in Formulas I-1 to I-3. Ⅰ-1 Ⅰ-2 Ⅰ-3。 3. The liquid crystal composition according to claim 1, characterized in that, The positive compound with a dielectric anisotropy greater than 2 is selected from the group consisting of compounds shown in Formula II and / or Formula III below. Ⅱ Ⅲ in, R4 and R5 each independently represent an alkyl group, an alkenyl group, or an alkoxy group with up to 15 carbon atoms, wherein one or more non-adjacent -CH2- groups can be independently converted to -C≡C-, -CH=CH-, -CF2O-, -OCF2-, -O-, -CO-O-, -O-CO-, or -C≡C-. , , , , or Replace them by ensuring that the O atoms are not connected to each other; a1 represents 1, 2, or 3; b1 represents 2, 3, or 4; X1 represents -F, -CF3, or -OCF3; X2 represents -H or -CH3; , , Each represents independently , , , , , , or When a1 represents 2 or 3, They are independently the same or different; when b1 represents 2, 3 or 4, They are either the same or different independently.

4. The liquid crystal composition according to claim 1, characterized in that, In the compound represented by Formula I, R1 represents an alkyl group with 1-10 carbon atoms, an alkoxy group with 1-10 carbon atoms, an alkenyl group with 2-10 carbon atoms, or an alkenyloxy group with 2-10 carbon atoms; X represents -S-.

5. The liquid crystal composition according to claim 3, characterized in that, The liquid crystal composition comprises one or more compounds of formula IV. Ⅳ in, R6 and R7 each independently represent an alkyl group, an alkenyl group, or an alkoxy group with a maximum of 15 carbon atoms; c1 and c2 each represent 1 or 2 independently; Z1 represents a single bond, -CH2-CH2-, -CH=CH-, -CF2O-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, or -CF=CF-; , Each represents independently , , , , When d or e represents 2, , They are either the same or different independently.

6. The liquid crystal composition according to claim 5, characterized in that, The liquid crystal composition comprises one or more compounds represented by formula V. Ⅴ And / or, one or more compounds of formula VI, Ⅵ in, R8 and R9 each independently represent an alkyl group having 1-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms, wherein one or more unconnected -CH2- groups are optionally substituted with cyclopropyl, cyclopentyl, or cyclobutyl groups. , , and Each represents independently , , , , or ; X3 and X5 each independently represent -H, -F, alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms; X4 and X6 each independently represent -H, -F, alkyl with 1-10 carbon atoms, alkoxy with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms, wherein any one or more hydrogen atoms may be optionally substituted with fluorine atoms; W1 and W2 each independently represent -O- or -S-.

7. The liquid crystal composition according to claim 5, characterized in that, The liquid crystal composition comprises one or more compounds represented by formula VII. Ⅶ in, R 10 R 11 Each of the following can independently represent an alkyl group having 1-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms, wherein one or more unconnected -CH2- groups are optionally substituted with cyclopropyl, cyclopentyl, or cyclobutyl groups. Z2 represents a single bond, -CH2-CH2-, -CH=CH-, -CF2O-, -CH2O-, -OCH2-, -COO-, -OCO-, -C2F4-, or -CF=CF-; express , , , or ; d1 represents 0, 1, 2, or 3; when d1 represents 2 or 3, They are either the same or different independently; d2 represents 0 or 1.

8. The liquid crystal composition according to claim 6 or 7, characterized in that, The liquid crystal composition contains 0.1%-25% by mass of the compound represented by Formula I, and / or The compound represented by Formula II has a mass percentage content of 1%-20%, and / or The compound represented by Formula III has a mass percentage content of 1%-30%, and / or The compound represented by Formula IV has a mass percentage content of 20%-80%, and / or The compound represented by formula V has a mass percentage content of 0-20%, and / or The compound represented by Formula VI has a mass percentage content of 0-20%, and / or The mass percentage of the compound represented by Formula VII is 0-20%.

9. The liquid crystal composition according to any one of claims 1-7, characterized in that, The liquid crystal composition contains one or more additives.

10. The liquid crystal composition according to claim 9, characterized in that, The additives include at least one of antioxidants or light stabilizers; The additive accounts for 0.0001%-2% of the total mass.

11. A liquid crystal display element, characterized in that, It comprises the liquid crystal composition according to any one of claims 1-10.

12. A liquid crystal display, characterized in that, It comprises the liquid crystal composition according to any one of claims 1-10.

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