Liquid crystal composition and liquid crystal display device

Abstract

A liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, and at least one compound of general formula III. By means of mutual compounding of the specific structures and contents of the compounds, the liquid crystal composition has an appropriate vertical dielectric constant, appropriate dielectric anisotropy, relatively high optical anisotropy, relatively low rotational viscosity, relatively short gray-to-gray, relatively good low-temperature storage stability, and a relatively good flicker value, and also has a relatively large phase width to meet display requirements at relatively low temperatures, so that the liquid crystal display device including the liquid crystal composition has a relatively small threshold voltage, a relatively high response speed, a relatively high contrast ratio, and a relatively wide operating temperature range.

Description

Liquid crystal composition and liquid crystal display device Technical Field

[0001] The present invention belongs to the technical field of liquid crystal materials, and in particular relates to a liquid crystal composition and a liquid crystal display device thereof. Background Art

[0002] 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 display devices operate by utilizing the optical anisotropy and dielectric anisotropy of the liquid crystal material itself.

[0003] Liquid crystal display devices are classified into the following modes based on their display method: twisted nematic (TN), super twisted nematic (STN), in-plane switching (IPS), fringe field switching (FFS), and vertical alignment (VA). The IPS display mode is ideal for TFT-LCDs (thin-film transistor liquid crystal displays) due to its excellent viewing angle characteristics, dynamic clarity, and color reproduction. IPS is also an ideal choice for aerospace, medical, and automotive applications.

[0004] Thin-film transistor liquid crystal displays (TFT-LCDs) play a pivotal role in the display industry. With the widespread adoption of TFT-LCDs, performance requirements are constantly increasing. Not only must the physical parameters of the liquid crystal material (such as dielectric anisotropy, optical anisotropy, and elastic constants) match device requirements, but the material must also exhibit high stability, including high-temperature and chemical stability. Currently, the storage temperature range for general liquid crystal materials is -40°C to 100°C. However, for displays with specialized application requirements (such as automotive), the operating temperature range is currently required to be -40°C to 90°C, extending this range to -50°C to 110°C. Furthermore, high-definition display image quality requires faster response speeds (the lower the rotational viscosity γ1, the better; lower the rotational viscosity, the faster the response speed) and reduced flicker. During the use of LCD panels, the polarity switching of the common electrode signal (Vcom) causes horizontal stripes to flicker, a phenomenon commonly referred to in the industry as the flicker phenomenon. The flicker value directly reflects the quality and reliability of the LCD panel. Generally, a higher flicker value indicates a higher likelihood of image sticking (IS) on the LCD panel, while a lower flicker value reduces or prevents image sticking. Severe flickering can lead to increased image sticking on the LCD panel, reducing display quality and causing physiological discomfort to viewers (such as eye fatigue, decreased vision, and dizziness). Therefore, during the TFT-LCD production process, flicker values ​​must be measured and controlled within a predetermined range.

[0005] Compared to LCDs used in televisions, computers, mobile phones, and other fields, automotive LCDs, in addition to the aforementioned performance, also require a wider operating temperature range and superior reliability to adapt to temperature fluctuations in different regions and seasons, and to maintain normal display under long-term outdoor sunlight and high-temperature environments. This requires that the liquid crystal compositions used in automotive displays not only have appropriate delay and threshold voltage, but also have shorter grayscale response time (GTG) at low temperatures, good flicker value, a wide operating temperature range, and excellent reliability.

[0006] Adjusting the formulation of a liquid crystal composition involves simultaneously adjusting many of the composition's performance parameters. It's impossible to adjust one performance parameter without affecting another. Sometimes, adjusting one performance parameter of a liquid crystal composition by adding a certain monomeric liquid crystal may benefit one or more other properties, but may also negatively impact the improvement of yet other properties. Therefore, obtaining liquid crystal compositions that fully or partially address these issues remains an urgent challenge in the field.

[0007] Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention aims to provide a liquid crystal composition and a liquid crystal display device. The liquid crystal composition has appropriate vertical dielectric constant, appropriate dielectric anisotropy, large optical anisotropy, small rotational viscosity, shorter grayscale response time, good low-temperature storage stability, and good Flicker value. In addition, the liquid crystal composition has a wider phase width to meet display requirements at lower temperatures, so that the liquid crystal display device containing the liquid crystal composition has a smaller threshold voltage, a faster response speed, a larger contrast, and a wider temperature operating range.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a liquid crystal composition comprising:

[0011] At least one compound of the general formula I:

[0012] At least one compound of formula II:

[0013] as well as

[0014] At least one compound of formula III:

[0015] wherein R1 and R2 each independently represent a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and wherein the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl;

[0016] R3 and R4 each independently represent a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a straight-chain alkenyl group containing 2 to 12 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a straight-chain alkoxy group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, and at least one of R3 and R4 is a straight chain alkenyl group containing 2 to 12 carbon atoms;

[0017] ring ring and Ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, one or at most two single bonds in the ring may be replaced by double bonds, and wherein One or more -H in may be substituted by halogen;

[0018] ring express

[0019] Z 11 , Z 12 , Z 21 , Z 22 , Z 31 and Z 32 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -C≡C-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-;

[0020] L 11 、L 12 、L 21 and L 22 Each independently represents -H, halogen, or an alkyl group containing 1 to 3 carbon atoms; and

[0021] X1 and X2 each independently represent a halogen, a haloalkyl group containing 1 to 5 carbon atoms, a haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl group containing 2 to 5 carbon atoms, or a haloalkenyloxy group containing 2 to 5 carbon atoms.

[0022] In some embodiments of the present invention, preferably, the ring ring and Ring Each independently expresses in One or more -H in the ring may be substituted by halogen; further preferably, ring and Ring Each independently expresses

[0023] In the liquid crystal composition provided by the present invention, the compound of general formula I, the compound of general formula II, and the compound of general formula III are compounded with each other through specific structures and contents, so that the liquid crystal composition has appropriate vertical dielectric, appropriate dielectric anisotropy, large optical anisotropy, small rotational viscosity, shorter grayscale response time, good low-temperature storage stability, and good Flicker value, while also having a wider phase width to meet display requirements at lower temperatures.

[0024] In the present invention, “may be replaced by…” means that it may (can) be replaced or not replaced, that is, being replaced or not being replaced falls within the scope of protection of the present invention; the same applies to “may be replaced by…”; moreover, the positions of “replace” and “replace” are arbitrary.

[0025] In the present invention, the short straight lines on one or both sides of the group represent access bonds and do not represent methyl groups (e.g. The short straight line on the left and short straight lines on either side).

[0026] In the present invention, the halogen includes halogen elements such as fluorine, chlorine, bromine or iodine; when the same description is mentioned below, they have the same meaning.

[0027] In the present invention, the halogenated group means that at least one hydrogen atom in the group is replaced by a halogen atom (fluorine, chlorine, bromine or iodine, etc.).

[0028] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of: as well as

[0029] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet display requirements at lower temperatures, the compound of general formula I contains at least one compound of general formula I-1.

[0030] In some embodiments of the present invention, the content of the compound of general formula I is preferably adjusted so that the liquid crystal composition of the present invention has appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet display requirements at lower temperatures.

[0031] In some embodiments of the present invention, the weight percentage of the compound of general formula I in the liquid crystal composition is 0.1%-20% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 3.5%, 4%, 5%, 5.5%, 6%, 6.5%, 7%, 8%, 8.5%, 10%, 11.5%, 12%, 14%, 16%, 18%, 20%, or a range between any two values ​​therein. Preferably, the weight percentage of the compound of general formula I in the liquid crystal composition is 1%-10%.

[0032] In some embodiments of the present invention, the weight percentage of the compound of formula I-1 in the liquid crystal composition is 4% to 9%.

[0033] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of: as well as

[0034] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet display requirements at lower temperatures, the compound of general formula II includes any one or a combination of at least two of the compounds of general formula II-1 and the compounds of general formula II-5.

[0035] In some embodiments of the present invention, the content of the compound of general formula II is preferably adjusted so that the liquid crystal composition of the present invention has appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet display requirements at lower temperatures.

[0036] In some embodiments of the present invention, the weight percentage of the compound of general formula II in the liquid crystal composition is 0.1%-20% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 3%, 4%, 5%, 5.5%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, or a range between any two values ​​therein. Preferably, the weight percentage of the compound of general formula II in the liquid crystal composition is 1%-10%.

[0037] In some embodiments of the present invention, the weight percentage of any one or a combination of at least two of the compound of formula II-1 and the compound of formula II-5 in the liquid crystal composition is 1% to 5%.

[0038] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of: as well as

[0039] wherein R3 and R4 each independently represent a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, or a straight-chain alkoxy group containing 1 to 9 carbon atoms;

[0040] R 31 and R 41 Each independently represents a straight-chain alkenyl group containing 2 to 8 carbon atoms;

[0041] Z 31 and Z 32 Each independently represents a single bond, -CH2CH2- or -CH=CH-.

[0042] In some embodiments of the present invention, it is further preferred that R 31 and R 41 Each independently represents a straight-chain alkenyl group containing 2 to 5 carbon atoms.

[0043] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures, the compound of general formula III includes any one or a combination of at least two of the compounds of general formula III-5, the compounds of general formula III-6, the compounds of general formula III-7, the compounds of general formula III-8, the compounds of general formula III-13 and the compounds of general formula III-14.

[0044] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of: as well as

[0045] In some embodiments of the present invention, the content of the compound of general formula III is preferably adjusted so that the liquid crystal composition of the present invention has appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures.

[0046] In some embodiments of the present invention, the weight percentage of the compound of general formula III in the liquid crystal composition is 0.1%-30% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, or a range between any two values ​​therein. Preferably, the weight percentage of the compound of general formula III in the liquid crystal composition is 1%-20%.

[0047] In some embodiments of the present invention, the weight percentage of any one or a combination of at least two of the compounds of formula III-5, formula III-6, formula III-7, formula III-8, formula III-13 and formula III-14 in the liquid crystal composition is 5%-12% (including any value or sub-range between this range), for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, or a range between any two of the values ​​therein.

[0048] In some embodiments of the present invention, the weight percentage of any one or a combination of at least two of the compounds of general formula III-5-1, the compounds of general formula III-6-1, the compounds of general formula III-7-1, the compounds of general formula III-8-1, the compounds of general formula III-13-3 and the compounds of general formula III-14-1 in the liquid crystal composition is 5%-12% (including any value or sub-range between this range), for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, or a range between any two of the values ​​therein.

[0049] In some embodiments of the present invention, the liquid crystal composition of the present invention further comprises at least one compound of the general formula M:

[0050] Among them, R M1and R M2 each independently represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a straight-chain alkenyl group containing 2 to 12 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a straight-chain alkoxy group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms,

[0051] ring ring and Ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, one or at most two single bonds in the ring may be replaced by double bonds, and wherein At most one -H in may be replaced by halogen;

[0052] Z M1 and Z M2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -O-CO-O-, -C≡C-, -CH=CH- or -(CH2)4-;

[0053] n M represents 0, 1 or 2, where n M When it means 2, the ring Can be the same or different, Z M2 Can be the same or different; when n M Indicates 1, ring At least one And ring for When R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms,

[0054] In some embodiments of the present invention, preferably, R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 10 carbon atoms, a straight-chain alkoxy group containing 1 to 9 carbon atoms, or a straight-chain alkenyl group containing 2 to 10 carbon atoms; further preferably, R M1 and R M2Each independently represents a straight-chain alkyl group containing 1 to 8 carbon atoms, a straight-chain alkoxy group containing 1 to 7 carbon atoms, or a straight-chain alkenyl group containing 2 to 8 carbon atoms.

[0055] In some embodiments of the present invention, preferably R M1 and R M2 Each independently represents a straight chain alkenyl group containing 2 to 8 carbon atoms; further preferably R M1 and R M2 Each independently represents a straight-chain alkenyl group containing 2 to 5 carbon atoms.

[0056] In some embodiments of the present invention, preferably, R M1 and R M2 One of them is a straight-chain alkenyl group containing 2 to 5 carbon atoms, and the other is a straight-chain alkyl group containing 1 to 5 carbon atoms.

[0057] In some embodiments of the present invention, when reliability is important, R M1 and R M2 are all alkyl groups; when it is important to reduce the volatility of the compound, R M1 and R M2 are all alkoxy groups; when the viscosity reduction is important, R M1 and R M2 At least one of them is an alkenyl group.

[0058] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of: as well as

[0059] Among them, R M1 ' and R M21 'Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms,

[0060] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures, the compound of general formula M includes any one or a combination of at least two of the compounds of general formula M-1, the compounds of general formula M-3, the compounds of general formula M-5, the compounds of general formula M-9, the compounds of general formula M-12, the compounds of general formula M-13, the compounds of general formula M-15, the compounds of general formula M-17 and the compounds of general formula M-25.

[0061] In some embodiments of the present invention, the compound of formula M-1 is selected from the group consisting of:

[0062] as well as

[0063] where R M1 represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, or a straight-chain alkoxy group containing 1 to 9 carbon atoms;

[0064] R M11 and R M21 Each independently represents a straight-chain alkenyl group containing 2 to 8 carbon atoms.

[0065] In some embodiments of the present invention, the compound of formula M-1 is selected from the group consisting of: as well as

[0066] In some embodiments of the present invention, the compound of formula M-12 is selected from the group consisting of: as well as

[0067] where R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, or a straight-chain alkoxy group containing 1 to 9 carbon atoms;

[0068] R M11 and R M21 Each independently represents a straight-chain alkenyl group containing 2 to 8 carbon atoms.

[0069] In some embodiments of the present invention, the compound of formula M-12 is selected from the group consisting of: as well as

[0070] In some embodiments of the present invention, the compound of formula M-17 is selected from the group consisting of: as well as

[0071] where R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, or a straight-chain alkoxy group containing 1 to 9 carbon atoms;

[0072] R M11 and R M21 Each independently represents a straight-chain alkenyl group containing 2 to 8 carbon atoms.

[0073] In some embodiments of the present invention, the compound of formula M-17 is selected from the group consisting of: as well as

[0074] In some embodiments of the present invention, it is preferred to adjust the content of the compound of the general formula M so that the liquid crystal composition of the present invention has appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures.

[0075] In some embodiments of the present invention, the weight percentage of the compound of general formula M in the liquid crystal composition is 0.1%-90%, for example, it can be 0.1%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 79%, 80%, 81%, 82%, 84%, 86%, 88%, 90%, or a range between any two values. Preferably, the weight percentage of the compound of general formula M in the liquid crystal composition is 30%-90%.

[0076] In some embodiments of the present invention, the weight percentage of any one of the compounds of general formula M-1, the compounds of general formula M-3, the compounds of general formula M-5, the compounds of general formula M-9, the compounds of general formula M-12, the compounds of general formula M-13, the compounds of general formula M-15, the compounds of general formula M-17 and the compounds of general formula M-25, or a combination of at least two of them in the liquid crystal composition is 56%-82% (including any numerical value or sub-range between this range), for example, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, or a range between any two of the numerical values.

[0077] In some embodiments of the present invention, the compound of the general formula M-1-1-2, the compound of the general formula M-1-1-3, the compound of the general formula M-1-1-4, the compound of the general formula M-1-2-3, the compound of the general formula M-3, the compound of the general formula M-5, the compound of the general formula M-9, the compound of the general formula M-12-1-1, the compound of the general formula M-12-5-1, the compound of the general formula M-12-11-2, the compound of the general formula M-13, the compound of the general formula M-15, the compound of the general formula M-17-11-1, the compound of the general formula M-17-11-2, the compound of the general formula M-17-11-3, the compound of the general formula M-17-11-4, the compound of the general formula M-17-11-5, the compound of the general formula M-17-11-2 ...1, the compound of the general formula M-17-11-2, the compound of the general formula M-17-11-3, the compound of the general formula M-17-11-4, the compound of the general formula M-17-11-1, the compound of the general formula M-17-11 -17-11-3 and the compound of formula M-25, or a combination of any one or at least two of them, accounts for 56% to 82% by weight of the liquid crystal composition (including any numerical value or sub-range between the range), for example, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, or a range between any two of the numerical values.

[0078] In some embodiments of the present invention, the liquid crystal composition of the present invention further comprises at least one compound selected from the group consisting of compounds of formula N-1 and compounds of formula N-2:

[0079] Among them, R N1 and R N2 Each independently represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, wherein one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight-chain alkyl group containing 1-12 carbon atoms, the branched-chain alkyl group containing 3-12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl;

[0080] ring ring ring and Ring Each independently expresses wherein One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=;

[0081] Z N11 , Z N21 and Z N22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-;

[0082] L N11 、L N12 、L N21 and L N22 Each independently represents -H, halogen, a haloalkyl group containing 1 to 3 carbon atoms, or a haloalkoxy group containing 1 to 3 carbon atoms;

[0083] L N13 represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms;

[0084] X N1 and X N2 each independently represents halogen, a haloalkyl group having 1 to 5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, a haloalkoxy group having 1 to 5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, a haloalkenyl group having 2 to 5 (e.g., 2, 3, 4, or 5) carbon atoms, or a haloalkenyloxy group having 2 to 5 (e.g., 2, 3, 4, or 5) carbon atoms;

[0085] n N11Represents 0, 1, 2, or 3, where n N11 When it means 2 or 3, the ring Can be the same or different, Z N11 Can be the same or different;

[0086] Among them, when n N11 It means 2 o'clock. Not for

[0087] n N12 represents 1 or 2, where n N12 When it means 2, the ring may be the same or different; and,

[0088] n N2 represents 0, 1, 2, or 3, where n N2 When it means 2 or 3, the ring Can be the same or different, Z N21 Can be the same or different.

[0089] In some embodiments of the present invention, the compound of formula N-1 is selected from the group consisting of: as well as

[0090] Among them, R N1 represents a straight chain alkyl group containing 1 to 8 carbon atoms, wherein one or more non-adjacent -CH2- in a linear alkyl group containing 1 to 8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H groups present in these groups may be independently replaced by -F or -Cl;

[0091] L N11 、L N12 、L N14 、L N15 and L N16 Each independently represents -H or -F;

[0092] L N13 represents -H or -CH3; and

[0093] X N1 Indicates -F, -CF3 or -OCF3.

[0094] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures, the compound of general formula N-1 includes any one or a combination of at least two of the compounds of general formula N-1-1, the compound of general formula N-1-6 and the compound of general formula N-1-12.

[0095] In some embodiments of the present invention, the compound of formula N-2 is selected from the group consisting of: as well as

[0096] Among them, R N2 represents a straight-chain alkyl group containing 1 to 8 carbon atoms, wherein one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H groups present in these groups may be independently replaced by -F or -Cl;

[0097] L N21 、L N22 、L N23 、L N24 and L N25 each independently represents -H or -F; and

[0098] X N2 Indicates -F, -CF3 or -OCF3.

[0099] In some embodiments of the present invention, in order to obtain a liquid crystal composition having appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures, the compound of general formula N-2 includes any one or a combination of at least two of the compounds of general formula N-2-5, the compounds of general formula N-2-14 and the compounds of general formula N-2-20.

[0100] In some embodiments of the present invention, it is preferred to adjust the content of the compound of general formula N-1 and / or the compound of general formula N-2 so that the liquid crystal composition of the present invention has appropriate vertical dielectric, appropriate dielectric anisotropy, larger optical anisotropy, smaller rotational viscosity, shorter grayscale response time, better low-temperature storage stability, better Flicker flicker value, and wider phase width to meet the display requirements at lower temperatures.

[0101] In some embodiments of the present invention, the weight percentage of the compound selected from the group consisting of the compound of general formula N-1 and the compound of general formula N-2 in the liquid crystal composition is 0.1%-50% (including any value or sub-range between this range), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 9%, 10%, 11%, 12%, 14%, 16%, 18%, 20%, 21%, 23%, 25%, 26%, 27%, 29%, 30%, 32%, 33%, 35%, 37%, 39%, 40%, 42%, 44%, 46%, 48%, 50%, or a range between any two values.

[0102] In some embodiments of the present invention, the weight percentage of the compound of general formula N-1 in the liquid crystal composition is 0.1%-30% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 9%, 10%, 11%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, or a range between any two of the numerical values. Preferably, the weight percentage of the compound of general formula N-1 in the liquid crystal composition is 1%-20%.

[0103] In some embodiments of the present invention, the weight percentage of any one or a combination of at least two of the compounds of general formula N-1-1, the compounds of general formula N-1-6 and the compounds of general formula N-1-12 in the liquid crystal composition is 0.1%-18% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, or a range between any two of the numerical values.

[0104] In some embodiments of the present invention, the weight percentage of the compound of general formula N-2 in the liquid crystal composition is 0.1%-30% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 9%, 10%, 11%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, or a range between any two of the numerical values. Preferably, the weight percentage of the compound of general formula N-2 in the liquid crystal composition is 1%-20%.

[0105] In some embodiments of the present invention, the weight percentage of any one or a combination of at least two of the compound of formula N-2-5, the compound of formula N-2-14, and the compound of formula N-2-20 in the liquid crystal composition is 0.1%-10% (including any values ​​or sub-ranges therebetween), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these values.

[0106] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of the general formula P:

[0107] Among them, R P1 and R P2 Each independently represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, wherein one or more non-adjacent -CH2- in a straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0108] ring and Ring Each independently expresses wherein One or more -CH2- in the ring may be replaced by -O-, and one or more single bonds in the ring may be replaced by double bonds, wherein the One or more -H in the ring may be replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=;

[0109] Z P1 and Z P2Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0110] L P1 and L P2 each independently represents -H, halogen, or an alkyl group containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms; and,

[0111] n P1 Indicates 0, 1, 2, or 3, n P2 Represents 0 or 1, and 0≤n P1 +n P2 ≤3; when n P1 When it means 2 or 3, the ring Same or different, Z P1 Same or different.

[0112] In some embodiments of the present invention, L P1 and L P2 All represent -H.

[0113] In some embodiments of the present invention, the compound of formula P is selected from the group consisting of: as well as

[0114] In some embodiments of the present invention, preferably, R P1 and R P2 Each independently represents a straight-chain alkyl group containing 1 to 10 carbon atoms, a branched-chain alkyl group containing 3 to 10 carbon atoms, a straight-chain alkoxy group containing 1 to 9 carbon atoms, a branched-chain alkoxy group containing 3 to 9 carbon atoms, a straight-chain alkenyl group containing 2 to 10 carbon atoms, or a branched-chain alkenyl group containing 3 to 10 carbon atoms; further preferably, R P1 and R P2 Each independently represents a straight-chain alkyl group containing 1 to 8 carbon atoms, a straight-chain alkoxy group containing 1 to 7 carbon atoms, or a straight-chain alkenyl group containing 2 to 8 carbon atoms.

[0115] In some embodiments of the present invention, the compound of formula P-20 is selected from the following compounds:

[0116] In some embodiments of the present invention, the weight percentage of the compound of general formula P in the liquid crystal composition is 0.1%-20% (including any numerical value or sub-range between this range), for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range between any two values ​​therein. Preferably, the weight percentage of the compound of general formula P in the liquid crystal composition is 1%-10%.

[0117] In some embodiments of the present invention, the weight percentage of the compound of formula N-1 in the liquid crystal composition is 1% to 3%.

[0118] Another aspect of the present invention provides use of the aforementioned liquid crystal composition in a liquid crystal display device, particularly in a vehicle-mounted liquid crystal display device.

[0119] In some embodiments of the present invention, the liquid crystal composition further comprises at least one additive.

[0120] In addition to the above compounds, the liquid crystal composition of the present invention may also contain conventional nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, dopants, antioxidants, ultraviolet absorbers, infrared absorbers, polymerizable monomers or light stabilizers.

[0121] Possible dopants that are preferably added to the liquid crystal composition of the present invention are shown below: as well as

[0122] Wherein, * represents the chiral site.

[0123] In some embodiments of the present invention, the weight percentage of the dopant in the liquid crystal composition is 0%-5%; preferably, the weight percentage of the dopant in the liquid crystal composition is 0.01%-1%.

[0124] In addition, the additives such as antioxidants, light stabilizers, and ultraviolet absorbers used in the liquid crystal composition of the present invention are preferably the following:

[0125] Here, n represents a positive integer from 1 to 12.

[0126] Preferably, the antioxidant is selected from the compounds shown below:

[0127] In some embodiments of the present invention, the additive accounts for 0%-5% of the total weight of the liquid crystal composition; preferably, the additive accounts for 0.01%-1% of the total weight of the liquid crystal composition.

[0128] In a second aspect, the present invention provides a liquid crystal display device, comprising the liquid crystal composition according to the first aspect.

[0129] In some embodiments of the present invention, the liquid crystal display device is a vehicle-mounted liquid crystal display.

[0130] Compared with the prior art, the present invention has the following beneficial effects:

[0131] The liquid crystal composition provided by the present invention has, through the combination of specific structures and contents of the compounds, an appropriate vertical dielectric constant, an appropriate dielectric anisotropy, a large optical anisotropy, a small rotational viscosity, a shorter grayscale response time, good low-temperature storage stability, and a good flicker value. In addition, the composition also has a wider phase width to meet display requirements at lower temperatures, so that a liquid crystal display device containing the composition has a lower threshold voltage, a faster response speed, a larger contrast ratio, and a wider temperature operating range. DETAILED DESCRIPTION

[0132] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0133] For ease of expression, in the following examples and comparative examples, the group structures of the components in the liquid crystal composition are represented by the codes listed in Table 1:

[0134] Table 1

[0135] Take the following compound as an example:

[0136] If the structural formula is represented by the codes listed in Table 1, it can be expressed as: nCCGF, where n in the code represents the number of carbon atoms in the left-end alkyl group. For example, if n is "3", it means that the alkyl group is -C3H7; C in the code represents 1,4-cyclohexylene, G represents 2-fluoro-1,4-phenylene, and F represents a fluorine substituent.

[0137] The abbreviated codes for the test items in the following examples and comparative examples are as follows:

[0138] Cp clearing point (nematic-isotropic phase transition temperature, °C)

[0139] Δn optical anisotropy (589nm, 25℃)

[0140] ε⊥ Dielectric constant perpendicular to the molecular axis

[0141] Δε dielectric anisotropy (1kHz, 25℃)

[0142] γ1 Rotational viscosity (mPa·s, 25°C)

[0143] GTG: The time required to switch from one grayscale to another (-30℃, ms)

[0144] LTS(-42℃) Low temperature storage stability (-42℃, days)

[0145] Flicker value (dB)

[0146] in,

[0147] Cp: ​​obtained by melting point test;

[0148] Δn: measured using an Abbe refractometer under a sodium lamp (589 nm) at 25°C.

[0149] Δε: Δε=ε ∥ -ε ⊥ , where ε ∥ is the dielectric constant parallel to the molecular axis, ε ⊥ is the dielectric constant perpendicular to the molecular axis, tested at 25°C, 1 kHz, using a TN test cell with a thickness of 7 μm.

[0150] γ1: measured using the LCM-2 liquid crystal property evaluation system; test conditions: 25°C, 160-260V, test cell thickness 20μm;

[0151] GTG: measured using a DMS505 tester at -30°C, using a 3.5μm thick FFS test cell.

[0152] LTS (-42°C): The time when crystals are observed to precipitate after the nematic liquid crystal medium is placed in a glass bottle and stored at -42°C. For example, ">10" means that no crystals are precipitated after storage at -42°C for more than 10 days.

[0153] Flicker value: measured using a DMS505 tester. Test conditions: 25°C, 60 Hz, L127 voltage drive, and an ECB (3.0 μm FFS cell) test cell with a cell thickness of 4 μm.

[0154] The compounds used in the following examples can be synthesized by known methods or obtained through commercial channels. These synthesis techniques are conventional, and the resulting liquid crystal compositions have been tested to meet the standards of electronic compounds.

[0155] Liquid crystal compositions were prepared according to the ratios of the liquid crystal compositions in the following examples. The preparation of the liquid crystal compositions was carried out according to conventional methods in the art, such as mixing in a prescribed ratio by heating, ultrasonication, suspension, etc.

[0156] Example 1

[0157] The liquid crystal composition of Example 1 was prepared according to the compounds listed in Table 2 and their weight percentages in the liquid crystal composition, and then filled between two substrates of a liquid crystal display for performance testing.

[0158] Table 2 Formulation of liquid crystal composition and test results of performance parameters

[0159] Comparative Example 1

[0160] The liquid crystal composition of Comparative Example 1 was prepared according to the compounds listed in Table 3 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0161] Table 3 Formulation of liquid crystal composition and test results of performance parameters

[0162] From the comparison between Example 1 and Comparative Example 1, it can be seen that the present invention optimizes the structures and contents of the compound of Formula I, the compound of Formula II, and the compound of Formula III, so that the liquid crystal composition of the present invention has appropriate vertical dielectric constant, appropriate dielectric anisotropy, larger optical anisotropy, higher clearing point, smaller rotational viscosity, shorter grayscale response time, better Flicker value and longer low-temperature storage time.

[0163] Example 2

[0164] The liquid crystal composition of Example 2 was prepared according to the compounds listed in Table 4 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0165] Table 4 Formulation and performance parameter test results of liquid crystal composition

[0166] Example 3

[0167] The liquid crystal composition of Example 3 was prepared according to the compounds listed in Table 5 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0168] Table 5 Formulation and performance parameter test results of liquid crystal composition

[0169] Example 4

[0170] The liquid crystal composition of Example 4 was prepared according to the compounds listed in Table 6 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0171] Table 6 Formulation and performance parameter test results of liquid crystal composition

[0172] Example 5

[0173] The liquid crystal composition of Example 5 was prepared according to the compounds listed in Table 7 and their weight percentages in the liquid crystal composition, and then filled between two substrates of a liquid crystal display for performance testing.

[0174] Table 7 Formulation and performance parameter test results of liquid crystal composition

[0175] Example 6

[0176] The liquid crystal composition of Example 6 was prepared according to the compounds listed in Table 8 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0177] Table 8 Formulation and performance parameter test results of liquid crystal composition

[0178] Example 7

[0179] The liquid crystal composition of Example 7 was prepared according to the compounds listed in Table 9 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0180] Table 9 Formulation and performance parameter test results of liquid crystal composition

[0181] Example 8

[0182] The liquid crystal composition of Example 8 was prepared according to the compounds listed in Table 10 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0183] Table 10 Formulation and performance parameter test results of liquid crystal composition

[0184] Example 9

[0185] The liquid crystal composition of Example 9 was prepared according to the compounds listed in Table 11 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0186] Table 11 Formulation and performance parameter test results of liquid crystal composition

[0187] Example 10

[0188] The liquid crystal composition of Example 10 was prepared according to the compounds listed in Table 12 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0189] Table 12 Formulation and performance parameter test results of liquid crystal composition

[0190] Example 11

[0191] The liquid crystal composition of Example 11 was prepared according to the compounds listed in Table 13 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0192] Table 13 Formulation and performance parameter test results of liquid crystal composition

[0193] Comparative Example 2

[0194] The liquid crystal composition of Comparative Example 2 was prepared according to the compounds listed in Table 14 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0195] Table 14 Formulation and performance parameter test results of liquid crystal composition

[0196] Comparative Example 3

[0197] The liquid crystal composition of Comparative Example 3 was prepared according to the compounds listed in Table 15 and their weight percentages in the liquid crystal composition, and was filled between two substrates of a liquid crystal display for performance testing.

[0198] Table 15 Formulation and performance parameter test results of liquid crystal composition

[0199] From the comparison of Examples 1-11 of the present application and Comparative Examples 2-3, it can be seen that the present invention, by optimizing the structures and contents of the compounds of Formula I, Formula II and Formula III, enables the liquid crystal composition of the present invention to have appropriate vertical dielectric constant (2.7-3), appropriate dielectric anisotropy (3.4-5.5), larger optical anisotropy (0.101-0.112), higher clearing point (100.7-106), smaller rotational viscosity (62-72), shorter grayscale response time (240-275), better Flicker value (-65.45--62.89) and longer low-temperature storage time (>10).

[0200] In summary, the present invention, through the mutual compounding of the specific structure and content of the compounds, enables the liquid crystal composition to have a lower rotational viscosity and a faster low-temperature response speed (a smaller GTG value) while maintaining a higher clearing point, and can be stably stored at -42°C for more than 10 days, with a better Flicker value and a wider phase width to meet the display requirements at lower temperatures, so that the liquid crystal display device containing it has a lower threshold voltage, a higher contrast, a faster response speed, and a wider temperature range of use.

[0201] The applicant declares that the present invention uses the above-described embodiments to illustrate a liquid crystal composition and liquid crystal display device of the present invention. However, the present invention is not limited to the above-described embodiments, which does not necessarily mean that the present invention must rely on the above-described embodiments in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for various raw materials in the present invention, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention. Industrial Applicability

[0202] The liquid crystal composition and liquid crystal display device of the present invention can be applied to the field of liquid crystal material technology.

Claims

1. A liquid crystal composition, characterized in that: The liquid crystal composition comprises: At least one compound of the general formula I: At least one compound of formula II: as well as At least one compound of the general formula III: in, R1 and R2 each independently represent a straight chain alkyl group containing 1 to 12 carbon atoms, a branched chain alkyl group containing 3 to 12 carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight-chain alkyl group containing 1 to 12 carbon atoms, the branched-chain alkyl group containing 3 to 12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl; R3 and R4 each independently represent a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkenyl group containing 2 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms, wherein at least one of R3 and R4 is a straight chain alkenyl group containing 2 to 12 carbon atoms; ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, one or at most two single bonds in the ring may be replaced by double bonds, and wherein One or more -H in may be substituted with halogen; ring express Z 11 , Z 12 , Z 21 , Z 22 , Z 31 and Z 32 Each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -C≡C-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-; L 11 , L 12 , L 21 and L 22 Each independently represents -H, halogen or an alkyl group containing 1 to 3 carbon atoms; and X1 and X2 each independently represent a halogen, a haloalkyl group having 1 to 5 carbon atoms, a haloalkoxy group having 1 to 5 carbon atoms, a haloalkenyl group having 2 to 5 carbon atoms or a haloalkenyloxy group having 2 to 5 carbon atoms.

2. The liquid crystal composition according to claim 1, characterized in that: The compound of formula I is selected from the group consisting of the following compounds: The compound of formula II is selected from the group consisting of the following compounds: as well as The compound of formula III is selected from the group consisting of the following compounds: as well as wherein R3 and R4 each independently represent a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, or a straight-chain alkoxy group containing 1 to 9 carbon atoms; R 31 and R 41 Each independently represents a straight chain alkenyl group containing 2 to 8 carbon atoms; Z 31 and Z 32 Each independently represents a single bond, -CH2CH2- or -CH=CH-.

3. The liquid crystal composition according to claim 1, characterized in that: The weight percentage of the compound of general formula I in the liquid crystal composition is 0.1%-20%; the weight percentage of the compound of general formula II in the liquid crystal composition is 0.1%-20%; The weight percentage of the compound of formula III in the liquid crystal composition is 0.1%-30%.

4. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises at least one compound of the general formula M: Among them, R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkenyl group containing 2 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms, ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, one or at most two single bonds in the ring may be replaced by double bonds, and wherein At most one -H in may be replaced by halogen; Z M1 and Z M2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -O-CO-O-, -C≡C-, -CH=CH- or -(CH2)4-; n M represents 0, 1, or 2, where n M When it indicates 2, the ring Can be the same or different, Z M2 can be the same or different; when n M Indicates 1, ring At least one And ring for When R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms, 5. The liquid crystal composition according to claim 4, characterized in that: The compound of formula M is selected from the group consisting of the following compounds: as well as Among them, R M1 ' and R M21 'Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a straight-chain alkoxy group containing 1 to 12 carbon atoms, Wherein, the weight percentage of the compound of the general formula M in the liquid crystal composition is 0.1%-90%.

6. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises at least one compound selected from the group consisting of compounds of general formula N-1 and compounds of general formula N-2: Among them, R N1 and R N2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, wherein one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight-chain alkyl group containing 1 to 12 carbon atoms, the branched-chain alkyl group containing 3 to 12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl; ring ring ring and ring Each independently expresses It is stated One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bond replacement, and where One or more -H in the ring may be replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=; Z N11 , Z N21 and Z N22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-; L N11 , L N12 , L N21 and L N22 Each independently represents -H, halogen, a haloalkyl group containing 1 to 3 carbon atoms, or a haloalkoxy group containing 1 to 3 carbon atoms; L N13 represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms; X N1 and X N2 Each independently represents halogen, a haloalkyl group containing 1 to 5 carbon atoms, a haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl group containing 2 to 5 carbon atoms, or a haloalkenyloxy group containing 2 to 5 carbon atoms; n N11 represents 0, 1, 2, or 3, where n N11 When it means 2 or 3, the ring Can be the same or different, Z N11 can be the same or different; where n N11 It means 2 o'clock. Not for n N12 represents 1 or 2, where n N12 When it indicates 2, the ring may be the same or different; and, n N2 represents 0, 1, 2, or 3, where n N2 When it means 2 or 3, the ring Can be the same or different, Z N21 Can be the same or different.

7. The liquid crystal composition according to claim 6, characterized in that: The compound of formula N-1 is selected from the group consisting of the following compounds: as well as Among them, R N1 represents a straight chain alkyl group containing 1 to 8 carbon atoms, wherein one or more non-adjacent -CH2- in a straight-chain alkyl group containing 1 to 8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H present in these groups may be independently replaced by -F or -Cl; L N11 , L N12 , L N14 , L N15 and L N16 Each independently represents -H or -F; L N13 represents -H or -CH3; and X N1 represents -F, -CF3 or -OCF3; The compound of formula N-2 is selected from the group consisting of the following compounds: as well as Among them, R N2 It represents a straight-chain alkyl group containing 1 to 8 carbon atoms, wherein one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 8 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H present in these groups may be independently substituted by -F or -Cl; L N21 , L N22 , L N23 , L N24 and L N25 each independently represents -H or -F; and X N2 represents -F, -CF3 or -OCF3; The weight percentage of the compound selected from the group consisting of the compound of the general formula N-1 and the compound of the general formula N-2 in the liquid crystal composition is 0.1%-50%.

8. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises at least one compound of the general formula P: Among them, R P1 and R P2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, wherein one or more non-adjacent -CH2- in a straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; ring and ring Each independently expresses It is stated One or -CH2- may be replaced by -O-, and one or more single bonds in the ring may be replaced by double bonds, wherein the One or more -H in the ring may be replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=; Z P1 and Z P2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; L P1 and L P2 Each independently represents -H, halogen or an alkyl group containing 1 to 3 carbon atoms; and, n P1 Represents 0, 1, 2, or 3, n P2 Represents 0 or 1, and 0≤n P1 +n P2 ≤3; when n P1 When it means 2 or 3, the ring Same or different, Z P1 Same or different; Wherein, the compound of the general formula P is selected from the group consisting of the following compounds: as well as Wherein, the weight percentage of the compound of the general formula P in the liquid crystal composition is 0.1%-20%.

9. A liquid crystal display device, characterized in that: The liquid crystal display device comprises the liquid crystal composition according to any one of claims 1 to 8.

10. Use of the liquid crystal composition according to any one of claims 1 to 8 in a liquid crystal display device, especially in a vehicle-mounted liquid crystal display device.

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