Liquid crystal composition and liquid crystal display device

Abstract

The present invention provides a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I and at least one compound selected from compounds of general formula II-1 and / or compounds of general formula II-2. The liquid crystal composition according to the present invention has suitable optical anisotropy, a suitable clearing point, low rotational viscosity, high K ave value and high ε ⊥ / Δε ratio, and has high transmittance and contrast, as well as excellent low-temperature storage properties.

Description

[Technical Field]

[0001] The present invention belongs to the technical field of liquid crystal materials, and specifically relates to a liquid crystal composition and a liquid crystal display device, and more particularly to a liquid crystal composition and a liquid crystal display device having positive dielectric anisotropy. [Background technology]

[0002] Liquid crystal materials are mixtures of organic rod-like small-molecular compounds that exhibit the fluidity of a liquid and the anisotropy of a crystal at a certain temperature. Liquid crystal display devices (LCDs) utilize the optical and dielectric anisotropy of the LC material itself and are widely used. Depending on the operating mode of the LC molecules, LCDs can be divided into various types, including phase change (PC), twisted nematic (TN), super twisted nematic (STN), dynamic scattering (DS), ferroelectric liquid crystal (FLC), guest-host (GH), electrically controlled birefringence (ECB), optically compensated bend (OCB), in-plane switching (IPS), vertical alignment (VA), fringe field switching (FFS), and field-induced photoreactive alignment (FPA).

[0003] In the early 1970s, experimental studies were conducted on the fundamental electro-optical properties of IPS mode nematic liquid crystals, with both uniform and twisted alignments. This research was characterized by a pair of electrodes fabricated on one substrate and no electrodes fabricated on the other. Because the orientation of the liquid crystal molecules is controlled by applying a transverse electric field between the pair of electrodes, this mode is also known as transverse field mode. In IPS mode, the nematic liquid crystal molecules are uniformly and parallelly aligned between the two substrates, and two polarizers are arranged perpendicular to each other. In IPS mode, when no electric field is applied, incident light is blocked by the two orthogonal polarizers, resulting in a dark state. When an electric field is applied, the liquid crystal molecules rotate, causing retardation and light leakage through the two orthogonal polarizers. The advantages of IPS mode panels are a wide viewing angle and accurate color reproduction, but the disadvantages are relatively large light leakage and slow response time.

[0004] As TFT-LCDs are increasingly used, their performance requirements are also increasing. To achieve high-quality images, faster response speeds, lower power consumption, and higher low-temperature reliability are required. Furthermore, higher contrast and transmittance are also required, especially in IPS LCD display modes. This means that liquid crystal materials are required to have higher contrast and transmittance, larger elastic constants, higher dielectric constants, and higher low-temperature reliability. To improve these performances, improvements in liquid crystal materials are necessary.

[0005] IPS mode transmittance formula T∝|Δε| / ε ⊥ (T represents the transmittance, "∝" represents the "inverse proportional" relationship, and ε ⊥ Based on the principle that Δε represents the dielectric constant in the direction perpendicular to the molecular axis, it is possible to try to reduce the Δε of the liquid crystal medium to improve the transmittance of the liquid crystal, but this generally limits the adjustable range of the driving voltage of the same product. In addition, the liquid crystal molecules tilt in the Z-axis direction under the action of the perpendicular component of the fringe field, which changes their optical anisotropy, resulting in the formula

number

[0006] Meanwhile, based on measurements of the light leakage performance of conventional IPS-LCDs, it was discovered that the main causes of light leakage problems in LCD displays are light scattering (LC scattering), rubbing uniformity, light leakage from color filter films (CF / TFT scattering), and polarize ability, with light scattering accounting for 63% of the factors affecting light leakage performance.

[0007] The following relational expression

number

[0008] The relationship between contrast (CR) and brightness (L) is: CR=L 255 / L0×100% where L 255is the on-state luminance, and L0 is the off-state luminance. It can be seen that the change in L0 has a significant effect on CR. In the off-state, L0 is not related to the dielectric properties of the liquid crystal molecules, but is related to the LC scattering of the liquid crystal material itself. The smaller the LC scattering, the smaller L0 becomes, which significantly improves CR.

[0009] In view of the above situation, a general method for improving the contrast and transmittance is to: (1) change the dielectric anisotropy Δε of the liquid crystal composition without changing the ε ⊥ (2) By increasing the average elastic constant K of the liquid crystal composition, the transmittance can be effectively improved. ave By increasing the value of ε, the degree of order of the liquid crystal molecules is increased, and light leakage is reduced, thereby improving the transmittance. However, the liquid crystal compositions provided by the prior art have a low ε ⊥ / △ε ratio is small, K ave Therefore, how to provide a liquid crystal composition that can solve the above problems remains a technical problem that needs to be solved urgently in this field. Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the drawbacks of the prior art, the present invention provides a liquid crystal composition and a liquid crystal display device. In the present invention, a high K ave value and high ε ⊥ A liquid crystal composition having a / Δε ratio is provided, and thereby a liquid crystal composition having high transmittance and contrast as well as excellent low-temperature storage performance can be obtained. [Means for solving the problem]

[0011] To achieve this goal, the present invention employs the following technical solutions.

[0012] In a first aspect, the present invention provides a liquid crystal composition, comprising at least one compound of general formula I and at least one compound selected from compounds of general formula II-1 and / or compounds of general formula II-2, [ka] During the ceremony, R1 is -H, a halogenated or non-halogenated 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 halogenated or non-halogenated branched chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, a 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) alkyl group ... a halogenated or non-halogenated alkoxy group containing 2 to 12 (for example, which may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms; a halogenated or non-halogenated alkenyl group containing 2 to 12 (for example, which may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms; a halogenated or non-halogenated alkenyloxy group containing 2 to 12 (for example, which may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms; [ka] represents R 21 and R 32 each independently represents an alkyl group containing 1 to 12 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, an alkoxy group containing 1 to 12 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, an alkenyl group containing 2 to 12 (for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, or an alkenyloxy group containing 2 to 12 (for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, R 22represents a halogen atom, a halogenated alkyl group containing 1 to 5 (for example, which may be 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkoxy group containing 1 to 5 (for example, which may be 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkenyl group containing 2 to 5 (for example, which may be 2, 3, 4, or 5) carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 (for example, which may be 2, 3, 4, or 5) carbon atoms, R 31 represents -H, an alkyl group containing 1 to 12 (e.g., may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, or an alkoxy group containing 1 to 12 (e.g., may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms; [ka] teeth, [ka] represents [ka] where: [ka] One or at least two -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by a double bond; [ka] one or at least two -H in the ring may each independently be replaced with -F, -Cl, -CN, -CH3, or -OCH3, and one or at least two -CH= in the ring may each independently be replaced with -N=; [ka] are each independently, [ka] represents the above [ka] One or at least two -CH2- in the ring may be replaced by -O-, one or at least two single bonds in the ring may be replaced by a double bond, and at least one of the [ka] At least one single bond in is replaced with a double bond, and at least one of [ka] at least one single bond in is replaced with a double bond, L1 and L2 each independently represent a halogen atom; X1 and X2 each independently represent -O- or -S-; Z1 represents a single bond, -CO-O-, -O-CO-, -CHO-, -OCH-, -CH=CH-, -C≡C-, -CHCH-, -CFCF-, -(CH)-, -CFO- or -OCF-; n1 represents 0, 1 or 2, and when n1 represents 2, [ka] are the same or different, Z1 are the same or different, n2 represents 0, 1, 2, 3 or 4.

[0013] In the present invention, by designing the specific composition and compound structure of the liquid crystal composition, and further by using at least one compound of general formula I in combination with at least one compound of general formula II, the obtained liquid crystal composition has a high K ave value and high ε ⊥ / Δε ratio, and has high transmittance and contrast, as well as excellent low-temperature storage properties.

[0014] In the present invention, halogen atoms include fluorine atoms, chlorine atoms, bromine atoms and iodine atoms (the same applies hereinafter).

[0015] The following are preferred technical solutions of the present invention, but they are not intended to limit the technical solutions of the present invention. The following preferred technical solutions can better achieve and realize the objectives and beneficial effects of the present invention.

[0016] In some embodiments of the present invention, the compound of general formula I is [ka] and a combination of at least two of the compounds having the structure: wherein [ka] X1, X2, L1, L2, Z1 and R1 have the same protection scope as above.

[0017] In some embodiments of the present invention, [ka] teeth, [ka] Represents.

[0018] In some embodiments of the present invention, the compound of general formula I is a compound having the general formula I-1.

[0019] 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% to 20%, and may be, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, and more preferably 1% to 10%.

[0020] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula I, so that the liquid crystal composition containing the compound has a high K ave value and high ε ⊥ / Δε ratio, high transmittance and contrast, and excellent low-temperature storage performance.

[0021] In some embodiments of the present invention, the compound of general formula II-1 is [ka] and a combination of at least two of the compounds having the structure: In the formula, R 21 , R 31 and n2 have the same protection scope as above.

[0022] In some embodiments of the present invention, the weight percentage of the compound of general formula II-1 in the liquid crystal composition is 0.1% to 20%, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, and more preferably 1% to 10%.

[0023] In some embodiments of the present invention, the compound of general formula II-2 is [ka] and a combination of at least two of the compounds having the structure: In the formula, R 22 and R 32 has the same scope of protection as above.

[0024] In some embodiments of the present invention, the weight percentage of the compound of general formula II-2 in the liquid crystal composition is 0.1% to 20%, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, and more preferably 1% to 10%.

[0025] In some embodiments of the present invention, the liquid crystal composition comprises at least one of a compound of general formula II-1 and a compound of general formula II-2.

[0026] In some embodiments of the present invention, in the liquid crystal composition, the total weight percentage of the compound of general formula II-1 and the compound of general formula II-2 is 0.1% to 30%, and may be, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, and more preferably 1% to 15%.

[0027] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula II-1 and / or the compound of general formula II-2, so that the liquid crystal composition containing the compound has a high K ave value and high ε ⊥ / Δε ratio, high transmittance and contrast, and excellent low-temperature storage performance.

[0028] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of general formula III, [ka] During the ceremony, R2 is a linear 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 alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, [ka] and represents a linear alkyl group containing 1 to 12 carbon atoms, a branched alkyl group containing 3 to 12 carbon atoms, [ka] one or at least two non-adjacent -CH2- groups may each independently be replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; one or at least two -H groups in the linear alkyl group containing 1 to 12 carbon atoms or the branched alkyl group containing 3 to 12 carbon atoms may each independently be replaced by -F or -Cl; Z2 represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-; X3 represents -O- or -CH2-; X4 represents -F or -H; X5 represents a halogen atom, a halogenated alkyl group containing 1 to 5 (for example, 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkoxy group containing 1 to 5 (for example, 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkenyl group containing 2 to 5 (for example, 2, 3, 4, or 5) carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 (for example, 2, 3, 4, or 5) carbon atoms.

[0029] In some embodiments of the present invention, the liquid crystal composition comprises at least one compound of general formula III, wherein Z2 represents a single bond (for example, it may be two, three, four, five or six).

[0030] In some embodiments of the present invention, the liquid crystal composition comprises at least one (eg, may be two or three) compound of general formula III in which Z2 represents -CH2CH2-.

[0031] In some embodiments of the present invention, the liquid crystal composition comprises at least one compound of general formula III in which Z2 represents a single bond (e.g., two, three, four, five, or six), and at least one compound of general formula III in which Z2 represents -CH2CH2- (e.g., two or three).

[0032] 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% to 20%, and may be, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, and more preferably 5% to 15%.

[0033] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula III, so that the liquid crystal composition containing the compound has a high K ave value and high ε ⊥ / Δε ratio, high transmittance and contrast, and excellent low-temperature storage performance.

[0034] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of general formula N, [ka] During the ceremony, R N1 and R N2are each independently a linear 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 alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, [ka] wherein one or at least two non-adjacent —CH— groups in the linear alkyl group containing 1 to 12 carbon atoms or the branched alkyl group containing 3 to 12 carbon atoms may each independently be replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O—, or —O—CO—; [ka] are each independently, [ka] represents [ka] one or at least two -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by a double bond; [ka] one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; Z N1 and Z N2 each independently represents a single bond, -CO-O-, -O-CO-, -CHO-, -OCH-, -CH=CH-, -C≡C-, -CHCH-, -CFCF-, -(CH)-, -CFO-, or -OCF-, L N1 and L N2each independently represents -H, an alkyl group containing 1 to 3 (for example, 1, 2, or 3) carbon atoms, or a halogen atom; n N1 represents 0, 1, 2 or 3, and n N2 represents 0 or 1, and 0≦n N1 +n N2 ≦3, and n N1 If represents 2 or 3, [ka] are the same or different, and Z N1 are the same or different.

[0035] In some embodiments of the present invention, the compound of general formula N is [ka] [ka] [ka] and a combination of at least two of the compounds having the structure: In the formula, R N1 and R N2 has the same scope of protection as above.

[0036] In some embodiments of the present invention, the compound of general formula N is selected from the group consisting of a compound of general formula N-12, a compound of general formula N-19, and a compound of general formula N-21.

[0037] In some embodiments of the present invention, the weight percentage of the compound of general formula N in the liquid crystal composition is 0.1% to 20%, and may be, for example, 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, and more preferably 2% to 15%.

[0038] In some embodiments of the present invention, the liquid crystal composition further comprises the group consisting of at least one compound of general formula A-1 and at least one compound of general formula A-2, [ka] During the ceremony, R A1 and R A2 are each independently a linear 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 alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, [ka] and the linear alkyl group containing 1 to 12 carbon atoms, the branched alkyl group containing 3 to 12 carbon atoms, [ka] one or at least two non-adjacent -CH2- groups may each independently be replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; one or at least two -H groups in the linear alkyl group containing 1 to 12 carbon atoms or the branched alkyl group containing 3 to 12 carbon atoms may each independently be replaced by -F or -Cl; [ka] teeth, [ka] represents [ka] one or at least two -CH2- groups may be replaced by -O-; [ka] wherein one or at least two single bonds may be replaced by a double bond; [ka] one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; [ka] teeth, [ka] represents [ka] one or at least two -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by a double bond; [ka] one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; [ka] are each independently, [ka] represents [ka] one or at least two -CH2- groups may be replaced by -O-; [ka] wherein one or at least two single bonds may be replaced by a double bond; [ka] one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; Z A11 , Z A21 and Z A22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CHO- or -OCH2-, L A11 , L A12 , L A13 , L A21 and L A22 each independently represents -H, an alkyl group containing 1 to 3 (for example, 1, 2, or 3) carbon atoms, or a halogen atom; X A1 and X A2 each independently represent a halogen atom, a halogenated alkyl group containing 1 to 5 (for example, 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkoxy group containing 1 to 5 (for example, 1, 2, 3, 4, or 5) carbon atoms, a halogenated alkenyl group containing 2 to 5 (for example, 2, 3, 4, or 5) carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 (for example, 2, 3, 4, or 5) carbon atoms, n A11 represents 0, 1, 2 or 3, and n A11 If represents 2 or 3, [ka] are the same or different, and Z A11 are the same or different, n A12 represents 1 or 2, and n A12 If represents 2, [ka] are the same or different, n A2 represents 0, 1, 2 or 3, and n A2 If represents 2 or 3, [ka] are the same or different, and Z A21 are the same or different.

[0039] In some embodiments of the present invention, the compound of general formula A-1 is [ka] [ka] and a combination of at least two of the compounds having the structure: During the ceremony, R A1 is a linear alkyl group containing 1 to 8 (for example, 1, 2, 3, 4, 5, 6, 7, or 8) carbon atoms; a branched alkyl group containing 3 to 8 (for example, 3, 4, 5, 6, 7, or 8) carbon atoms; [ka] wherein one or at least two non-adjacent —CH— groups in the linear alkyl group containing 1 to 8 carbon atoms or the branched alkyl group containing 3 to 8 carbon atoms may each independently be replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO-O— or —O-CO-; and one or at least two —H groups in the linear alkyl group containing 1 to 8 carbon atoms or the branched alkyl group containing 3 to 8 carbon atoms may each independently be replaced by —F or —Cl; R v and R w each independently represents -CH2- or -O-, v and w each independently represent 0 or 1; L A11 , L A12 , L A11', L A12 ′, L A14 , L A15 and L A16 each independently represents -H or -F, L A13 and L A13 ' each independently represent -H or -CH3, X A1 represents -F, -CF3 or -OCF3.

[0040] In some embodiments of the present invention, the weight percentage of the compound of general formula A-1 in the liquid crystal composition is 0.1% to 20%, and may be, for example, 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%, and more preferably 4% to 15%.

[0041] In some embodiments of the present invention, by controlling the content of the compound of general formula A-1 within a specific range, the resulting liquid crystal composition has a suitable optical anisotropy, a suitable clearing point, a suitable absolute value of dielectric anisotropy, a large K ave value, small rotational viscosity, short response time, high transmittance, high contrast and long low-temperature storage time.

[0042] In some embodiments of the present invention, the compound of general formula A-2 is [ka] [ka] and a combination of at least two of the compounds having the structure: During the ceremony, R A2represents a linear alkyl group containing 1 to 8 (for example, 1, 2, 3, 4, 5, 6, 7, or 8) carbon atoms or a branched alkyl group containing 3 to 8 (for example, 3, 4, 5, 6, 7, or 8) carbon atoms, wherein one or at least two non-adjacent —CH— groups in the linear alkyl group containing 1 to 8 carbon atoms or the branched alkyl group containing 3 to 8 carbon atoms are each independently optionally substituted with —CH═CH—, —C≡C—, —O—, —CO—, —CO-O—, or —O-CO-, and one or at least two —H groups in the linear alkyl group containing 1 to 8 carbon atoms or the branched alkyl group containing 3 to 8 carbon atoms are each independently optionally substituted with —F or —Cl, L A21 , L A22 , L A23 , L A24 and L A25 each independently represents -H or -F, X A2 represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

[0043] In some embodiments of the present invention, the weight percentage of the compound of general formula A-2 in the liquid crystal composition is 0.1% to 20%, and may be, for example, 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%, and more preferably 1% to 10%.

[0044] In some embodiments of the present invention, by controlling the content of the compound of general formula A-2 within a specific range, the resulting liquid crystal composition has a suitable optical anisotropy, a suitable clearing point, a suitable absolute value of dielectric anisotropy, a large K ave value, small rotational viscosity, short response time, high transmittance, high contrast and long low-temperature storage time.

[0045] In some embodiments of the present invention, in the liquid crystal composition, the total weight percentage of the compound of general formula A-1 and the compound of general formula A-2 is 0.1% to 30%, for example, 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.

[0046] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of general formula M, [ka] During the ceremony, R M1 and R M2 are each independently a linear 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 alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, [ka] wherein one or at least two non-adjacent —CH— groups in the linear alkyl group containing 1 to 12 carbon atoms or the branched alkyl group containing 3 to 12 carbon atoms may each independently be replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O—, or —O—CO—; [ka] are each independently, [ka] represents [ka] one or at least two -CH2- groups may be replaced by -O-; [ka] wherein at most one -H may be replaced by a halogen atom; Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CHO-, -OCH-, -C≡C-, -CH=CH-, -CHCH- or -(CH)-; n M represents 0, 1 or 2, n M If represents 2, [ka] are the same or different, and Z M2 are the same or different.

[0047] In some embodiments of the present invention, the compound of general formula M is [ka] [ka] and a combination of at least two of the compounds having the structure: In the formula, R M1 and R M2 has the same scope of protection as above.

[0048] In some embodiments of the invention, the compound of general formula M is selected from the group consisting of a compound of general formula M-1, a compound of general formula M-2, a compound of general formula M-3, a compound of general formula M-10, a compound of general formula M-11, and a compound of general formula M-13.

[0049] In some embodiments of the present invention, the weight percentage of the compound of general formula M in the liquid crystal composition is 20% to 80%, and may be, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, and more preferably 40% to 68%.

[0050] In some embodiments of the present invention, the liquid crystal composition further comprises at least one additive.

[0051] The additives include nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, dopants, antioxidants, ultraviolet absorbers, infrared absorbers, polymerizable monomers, and light stabilizers.

[0052] In some embodiments of the present invention, the dopant is [ka] [ka] The compound is any one or a combination of at least two selected from the compounds listed above.

[0053] In some embodiments of the present invention, the weight percentage of the dopant in the liquid crystal composition is 0% to 5%, and may be, for example, 0%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, and more preferably 0.01% to 1%.

[0054] In some embodiments of the present invention, the additives such as antioxidants, light stabilizers, UV absorbers, etc. are preferably [ka] [ka] [ka] is a compound of In the formula, n represents a positive integer of 1 to 12, and may be, for example, 1, 2, 4, 6, 8, 9, 10, 11, or 12.

[0055] In some embodiments of the present invention, the antioxidant is [ka] The compound is any one or a combination of at least two selected from the compounds listed above.

[0056] In some embodiments of the present invention, the weight percentage of the light stabilizer in the liquid crystal composition is 0% to 5%, and may be, for example, 0%, 0.01%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, and more preferably 0.01% to 1%.

[0057] For ease of calculation, in the present invention, the sum of the weight percentages of compounds having different general formulas in the liquid crystal composition is 100%, and the content of additives is not included in the total content of the liquid crystal composition. That is, when the additives are added, the total content of each component in the liquid crystal composition is greater than 100%.

[0058] In some embodiments of the present invention, the liquid crystal composition further comprises a polymerization initiator, and examples of the polymerization initiator include, but are not limited to, benzoin ethers, benzophenones, acetophenones, benzil ketals, acylphosphine oxides, and the like.

[0059] In a second aspect, the present invention provides a liquid crystal display device, the liquid crystal display device comprising the liquid crystal composition according to the first aspect. [Effects of the Invention]

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] In the present invention, by designing the specific composition of the liquid crystal composition and the structure of the compound, and further by using a combination of compounds having different general formulas, it is possible to obtain a liquid crystal composition having a suitable optical anisotropy, a suitable clearing point, and a suitable dielectric anisotropy (ε ⊥ , ε ll or Δε), high K ave value, high ε ⊥ / Δε ratio, high transmittance, small rotational viscosity and long low-temperature storage time. DETAILED DESCRIPTION OF THE INVENTION

[0062] In order to facilitate understanding of the present invention, examples of the present invention are listed below. Those skilled in the art should understand that the examples are only for understanding the present invention and should not be considered as specifically limiting the present invention.

[0063] For ease of explanation, in the following examples, the group structures of the liquid crystal compositions are represented by the codes shown in Table 1.

[0064] [Table 1(1)] [Table 1(2)] In Table 1, the dashed lines represent the attachment sites of the radicals.

[0065] Take the following structural formula as an example: [ka]

[0066] When the structural formula is represented by the code shown in Table 1, it can be represented as nCCGF, where n in the code represents the number of C atoms in the alkyl group at the left end. For example, when n is "3", this represents that the alkyl group is -C3H7, and C in the code represents a cyclohexanyl group, G represents a 2-fluoro-1,4-phenylene group, and F represents fluorine.

[0067] In the following Examples and Comparative Examples, the abbreviations for the performance measurement items are as shown in Table 2.

[0068] [Table 2] Cp (°C): Measured using a melting point measuring apparatus using a quantitative method. Δn: measured at 20°C using an Abbe refractometer under a sodium lamp (589 nm) light source, Δn=n e -n o and n o is the refractive index of ordinary light, and n e is the extraordinary refractive index. Δε:Δε=ε ∥ -ε ⊥ and ε ∥ is the dielectric constant parallel to the molecular axis, and ε ⊥ is the dielectric constant perpendicular to the molecular axis, the measurement conditions are 20°C, 1 kHz, the measurement cell is a TN cell, and the cell thickness is 7 μm. γ1: Obtained by measurement using an LCM-2 type liquid crystal property evaluation system. Measurement conditions: 20° C., 160 to 240 V, and a measurement cell thickness of 20 μm. K ave :K ave =(K 11 +K 22 +K 33 ) / 3, and K 11 is the Splay elastic constant, K 22 is the twist elastic constant, K 33 is the bend elastic constant, K 11 , K. 22 and K. 33 is obtained by measuring and calculating the capacitance-voltage characteristic curve (CV curve) of the liquid crystal material using an LCR meter and an anti-parallel rubbing cell, and the measurement conditions are: an anti-parallel rubbing cell with a thickness of 7 μm, and V = 0.1 to 20 V. T r The VT curve of the dimming device was measured using a DMS 505 photoelectric integrated measuring device, and the maximum transmittance value in the VT curve was taken as the transmittance of the liquid crystal. The measurement cell used was a positive IPS-type measuring cell with a thickness of 3.5 μm, and V = 0 to 20 V. LTS (-30°C): A nematic phase liquid crystal medium was placed in an antiparallel cell, which is an IPS-type measurement cell with a thickness of 3.5 μm, and stored at a constant temperature of -30°C. LTS is the time recorded when crystal precipitation was observed. 168h NG indicates that crystals precipitated after 168 hours of storage, 168h OK indicates that no crystals precipitated after 168 hours of storage, and 240h OK indicates that no crystals precipitated after 240 hours of storage.

[0069] Example 1 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0070] [Table 3]

[0071] The structural formula of 5PGP(NA) is: [ka] is.

[0072] Example 2 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0073] [Table 4]

[0074] Example 3 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0075] [Table 5]

[0076] Example 4 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0077] [Table 6]

[0078] Example 5 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0079] [Table 7]

[0080] Example 6 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0081] [Table 8]

[0082] Comparative Example 1 In this comparative example, a liquid crystal composition is provided, which contains components in the mass percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0083] [Table 9]

[0084] Comparative Example 2 In this comparative example, a liquid crystal composition is provided, which contains components in the mass percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0085] [Table 10]

[0086] As can be seen from the comparison between Comparative Examples 1 and 2 and Example 6, the liquid crystal composition of the present invention can exhibit appropriate optical anisotropy, appropriate clearing point, appropriate dielectric anisotropy (ε ⊥ , ε ∥ , ε ⊥ / Δε), high K ave It has high viscosity, high transmittance, low rotational viscosity and good low-temperature storage stability.

[0087] Example 7 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0088] [Table 11]

[0089] Example 8 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0090] [Table 12]

[0091] Example 9 In this example, a liquid crystal composition is provided, which contains components in the weight percentages shown in the table below, and is filled between two substrates of a liquid crystal display to measure its performance.

[0092] [Table 13]

[0093] As can be seen from the above, in the present invention, by designing the specific composition of the liquid crystal composition and the structure of the compound, and further by using a combination of compounds having different general formulas, it is possible to obtain a liquid crystal composition having a suitable optical anisotropy, a suitable clearing point, a low rotational viscosity, a high K ave value and high ε ⊥ A liquid crystal composition having a high .DELTA..epsilon. / .DELTA..epsilon. ratio, high transmittance and contrast, and excellent low-temperature storage performance can be obtained.

[0094] The applicant claims that although the present invention has described the liquid crystal composition and liquid crystal display device of the present invention through the above examples, the present invention is not limited to the above examples, i.e., it does not mean that the present invention cannot be implemented without relying on the above examples. Those skilled in the art should understand that any improvements to the present invention, equivalent replacement of each raw material of the product of the present invention, addition of auxiliary ingredients, selection of specific methods, etc., are all within the protection scope and disclosure scope of the present invention. [Industrial Applicability]

[0095] The liquid crystal composition according to the present invention can be applied to the field of liquid crystals.

Claims

1. at least one compound of general formula I and at least one compound selected from compounds of general formula II-1 and / or compounds of general formula II-2, 【Chemistry 1】 During the ceremony, R １ represents -H, a halogenated or non-halogenated straight-chain alkyl group containing 1 to 12 carbon atoms, a halogenated or non-halogenated branched-chain alkyl group containing 3 to 12 carbon atoms, a halogenated or non-halogenated alkoxy group containing 1 to 12 carbon atoms, a halogenated or non-halogenated alkenyl group containing 2 to 12 carbon atoms, a halogenated or non-halogenated alkenyloxy group containing 2 to 12 carbon atoms, 【Chemistry 2】 represents R ２１ and R ３２ each independently represents an alkyl group containing 1 to 12 carbon atoms, an alkoxy group containing 1 to 12 carbon atoms, an alkenyl group containing 2 to 12 carbon atoms, or an alkenyloxy group containing 2 to 12 carbon atoms; R ２２ represents a halogen atom, a halogenated alkyl group containing 1 to 5 carbon atoms, a halogenated alkoxy group containing 1 to 5 carbon atoms, a halogenated alkenyl group containing 2 to 5 carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 carbon atoms; R ３１ represents —H, an alkyl group containing 1 to 12 carbon atoms, or an alkoxy group containing 1 to 12 carbon atoms; 【Transformation 3】 teeth, 【Chemistry 4】 represents 【Transformation 5】 teeth, 【Transformation 6】 where: 【Transformation 7】 One or at least two -CH ２ - may be replaced by -O-, one or at least two single bonds in the ring may be replaced by a double bond, 【Transformation 8】 In the formula (I), one or at least two —H are each independently —F, —Cl, —CN, or —CH ３ , or -OCH ３ one or at least two -CH= in the ring may each independently be replaced by -N=; 【Chemistry 9】 are each independently, 【Chemistry 10】 represents the above 【Chemistry 11】 One or at least two -CH ２ - may be replaced by -O-, one or at least two single bonds in the ring may be replaced by a double bond, and at least one of the above 【Chemistry 12】 At least one single bond in is replaced with a double bond, and at least one of 【Chemistry 13】 at least one single bond in is replaced with a double bond; L １ and L ２ each independently represents a halogen atom, X １ and X ２ each independently represents —O— or —S—, Z １ represents a single bond, —CO—O—, —O—CO—, —CH ２ O-, -OCH ２ -, -CH=CH-, -C≡C-, -CH ２ CH ２ -, -CF ２ CF ２ -, -(CH ２ ) ４ -, -CF ２ O- or -OCF ２ represents -, n １ represents 0, 1 or 2, n １ If represents 2, 【Chemistry 14】 are the same or different, and Z １ are the same or different, n ２ represents 0, 1, 2, 3 or 4.

2. The compound of general formula I is 【Chemistry 15】 and any one or a combination of at least two compounds having the structure: During the ceremony, The aforementioned 【Chemistry 16】 X １ , X ２ , L １ , L ２ , Z １ and R １ has the same scope of protection as claim 1, Preferably, the 【Chemistry 17】 teeth, [Chemistry 18] represents Preferably, the compound of general formula I is a compound having the general formula I-1, The liquid crystal composition according to claim 1, wherein the weight percentage of the compound of general formula I in the liquid crystal composition is preferably 0.1% to 20%, more preferably 1% to 10%.

3. The compound of the general formula II-1 is 【Chemistry 19】 and any one or a combination of at least two compounds having the structure: During the ceremony, The R ２１ , R ３１ and n ２ has the same scope of protection as claim 1, Preferably, in the liquid crystal composition, the weight percentage of the compound of general formula II-1 is 0.1% to 20%, more preferably 1% to 10%; Preferably, the compound of general formula II-2 is 【Chemistry 20】 and any one or a combination of at least two compounds having the structure: During the ceremony, The R ２２ and R ３２ has the same scope of protection as claim 1, Preferably, in the liquid crystal composition, the weight percentage of the compound of general formula II-2 is 0.1% to 20%, more preferably 1% to 10%; Preferably, in the liquid crystal composition, the total weight percentage of the compound of general formula II-1 and the compound of general formula II-2 is 0.1% to 30%, more preferably 1% to 15%. The liquid crystal composition according to claim 1 or 2.

4. further comprising at least one compound of general formula III: 【Chemistry 21】 During the ceremony, R ２ represents a straight chain alkyl group containing 1 to 12 carbon atoms, a branched chain alkyl group containing 3 to 12 carbon atoms, 【Chemistry 22】 wherein the linear alkyl group containing 1 to 12 carbon atoms, the branched alkyl group containing 3 to 12 carbon atoms, 【Chemistry 23】 one or at least two non-adjacent —CH ２ - may each independently be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the linear alkyl group containing 1 to 12 carbon atoms or branched alkyl group containing 3 to 12 carbon atoms may each independently be substituted by -F or -Cl; Z ２ is a single bond, -CH ２ CH ２ -, -CF ２ CF ２ -, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH ２ O- or -OCH ２ represents -, X ３ is —O— or —CH ２ represents -, X ４ represents -F or -H, X ５ represents a halogen atom, a halogenated alkyl group containing 1 to 5 carbon atoms, a halogenated alkoxy group containing 1 to 5 carbon atoms, a halogenated alkenyl group containing 2 to 5 carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 carbon atoms; The liquid crystal composition according to any one of claims 1 to 3, characterized in that the weight percentage of the compound of general formula III in the liquid crystal composition is preferably 0.1% to 20%, more preferably 5% to 15%.

5. further comprising at least one compound of general formula N, 【Chemistry 24】 During the ceremony, R Ｎ１ and R Ｎ２ are each independently a straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms; 【Chemistry 25】 and one or at least two non-adjacent —CH ２ - may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; 【Chemistry 26】 are each independently, 【Chemistry 27】 represents 【Chemistry 28】 One or at least two -CH ２ - may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by a double bond; 【Chemistry 29】 one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; Z Ｎ１ and Z Ｎ２ each independently represents a single bond, —CO—O—, —O—CO—, or —CH ２ O-, -OCH ２ -, -CH=CH-, -C≡C-, -CH ２ CH ２ -, -CF ２ CF ２ -, -(CH ２ ) ４ -, -CF ２ O- or -OCF ２ represents -, L Ｎ１ and L Ｎ２ each independently represents —H, an alkyl group containing 1 to 3 carbon atoms, or a halogen atom; n Ｎ１ represents 0, 1, 2 or 3; n Ｎ２ represents 0 or 1, and 0≦n Ｎ１ +n Ｎ２ ≦3, and n Ｎ１ When represents 2 or 3, 【Transformation 30】 are the same or different, and Z Ｎ１ are the same or different, Preferably, the compound of general formula N is 【Chemistry 31(1)】 【Chemistry 31(2)】 【Chemistry 31(3)】 and any one or a combination of at least two compounds having the structure: In the formula, R Ｎ１ and R Ｎ２ has the same scope of protection as above, Preferably, the compound of general formula N is 【Chemistry 32】 and a combination of any one or two of the compounds having the structure: In the formula, R Ｎ１ and R Ｎ２ has the same scope of protection as above, The liquid crystal composition according to any one of claims 1 to 4, characterized in that the weight percentage of the compound of general formula N in the liquid crystal composition is preferably 0.1% to 20%, more preferably 2% to 15%.

6. Further comprising the group consisting of at least one compound of general formula A-1 and at least one compound of general formula A-2, 【Transformation 33】 During the ceremony, R Ａ１ and R Ａ２ are each independently a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, 【Transformation 34】 wherein the linear alkyl group containing 1 to 12 carbon atoms, the branched alkyl group containing 3 to 12 carbon atoms, 【Chemistry 35】 one or at least two non-adjacent —CH ２ - may each independently be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the linear alkyl group containing 1 to 12 carbon atoms or branched alkyl group containing 3 to 12 carbon atoms may each independently be substituted by -F or -Cl; 【Transformation 36】 teeth, 【Chemistry 37】 represents 【Transformation 38】 One or at least two -CH ２ - may be replaced by -O-, 【Chemistry 39】 wherein one or at least two single bonds may be replaced by a double bond; 【Chemistry 40】 one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; 【Chemistry 41】 teeth, 【Chemistry 42】 represents 【Chemistry 43】 One or at least two -CH ２ - may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by a double bond; 【Chemistry 44】 one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; 【Chemistry 45】 are each independently, 【Chemistry 46】 represents 【Chemistry 47】 One or at least two -CH ２ - may be replaced by -O-, 【Chemistry 48】 wherein one or at least two single bonds may be replaced by a double bond; 【Chemistry 49】 one or at least two -H in the ring may each independently be replaced by -F, -Cl, or -CN, and one or at least two -CH= in the ring may each independently be replaced by -N=; Z Ａ１１ , Z Ａ２１ and Z Ａ２２ are each independently a single bond, —CH ２ CH ２ -, -CF ２ CF ２ -, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH ２ O- or -OCH ２ represents -, L Ａ１１ , L Ａ１２ , L Ａ１３ , L Ａ２１ and L Ａ２２ each independently represents —H, an alkyl group containing 1 to 3 carbon atoms, or a halogen atom; X Ａ１ and X Ａ２ each independently represents a halogen atom, a halogenated alkyl group containing 1 to 5 carbon atoms, a halogenated alkoxy group containing 1 to 5 carbon atoms, a halogenated alkenyl group containing 2 to 5 carbon atoms, or a halogenated alkenyloxy group containing 2 to 5 carbon atoms; n Ａ１１ represents 0, 1, 2 or 3; n Ａ１１ When represents 2 or 3, [Transformation 50] are the same or different, and Z Ａ１１ are the same or different, n Ａ１２ represents 1 or 2, n Ａ１２ If represents 2, 【Chemistry 51】 are the same or different, n Ａ２ represents 0, 1, 2 or 3; n Ａ２ When represents 2 or 3, 【Chemistry 52】 are the same or different, and Z Ａ２１ 6. The liquid crystal composition according to claim 1, wherein are the same or different.

7. The compound of the general formula A-1 is 【Chemistry 53(1)】 【Chemistry 53(2)】 and any one or a combination of at least two compounds having the structure: During the ceremony, The R Ａ１ represents a straight chain alkyl group containing 1 to 8 carbon atoms, a branched chain alkyl group containing 3 to 8 carbon atoms, 【Chemistry 54】 and one or at least two non-adjacent —CH ２ - may each independently be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the linear alkyl group containing 1 to 8 carbon atoms or branched alkyl group containing 3 to 8 carbon atoms may each independently be substituted by -F or -Cl; R ｖ and R ｗ are each independently —CH ２ - or -O-, v and w each independently represent 0 or 1; L Ａ１１ , L Ａ１２ , L Ａ１１ ', L Ａ１２ ', L Ａ１４ , L Ａ１５ and L Ａ１６ each independently represents —H or —F, L Ａ１３ and L Ａ１３ ' are each independently -H or -CH ３ represents The X Ａ１ is -F, -CF ３ or -OCF ３ represents The liquid crystal composition according to claim 6, wherein the weight percentage of the compound of general formula A-1 in the liquid crystal composition is preferably 0.1% to 20%, more preferably 4% to 15%.

8. The compound of the general formula A-2 is 【Chemistry 55(1)】 【Chemistry 55(2)】 and any one or a combination of at least two compounds having the structure: During the ceremony, The R Ａ２ represents a linear alkyl group containing 1 to 8 carbon atoms or a branched alkyl group containing 3 to 8 carbon atoms, and one or at least two non-adjacent —CH ２ - may each independently be substituted by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the linear alkyl group containing 1 to 8 carbon atoms or branched alkyl group containing 3 to 8 carbon atoms may each independently be substituted by -F or -Cl; L Ａ２１ , L Ａ２２ , L Ａ２３ , L Ａ２４ and L Ａ２５ each independently represents —H or —F, The X Ａ２ is -F, -CF ３ , -OCF ３ or -CH ２ CH ２ CH=CF ２ represents Preferably, in the liquid crystal composition, the weight percentage of the compound of General Formula A-2 is 0.1% to 20%, more preferably 1% to 10%; Preferably, in the liquid crystal composition, the total weight percentage of the compound of general formula A-1 and the compound of general formula A-2 is 0.1% to 30%. The liquid crystal composition according to claim 6 or 7.

9. further comprising at least one compound of general formula M, 【Transformation 56】 During the ceremony, R Ｍ１ and R Ｍ２ are each independently a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, 【Chemistry 57】 and one or at least two non-adjacent —CH ２ - may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; 【Chemistry 58】 are each independently, 【Chemistry 59】 represents 【Transformation 60】 One or at least two -CH ２ - may be replaced by -O-, 【Chemistry 61】 wherein at most one —H may be replaced by a halogen atom; Z Ｍ１ and Z Ｍ２ each independently represents a single bond, —CO—O—, —O—CO—, or —CH ２ O-, -OCH ２ -, -C≡C-, -CH=CH-, -CH ２ CH ２ - or - (CH ２ ) ４ represents -, n Ｍ represents 0, 1 or 2, n Ｍ If represents 2, 【Transformation 62】 are the same or different, and Z Ｍ２ are the same or different, Preferably, the compound of general formula M is 【Chemistry 63(1)】 【Chemistry 63(2)】 and any one or a combination of at least two compounds having the structure: In the formula, R Ｍ１ and R Ｍ２ has the same scope of protection as above, Preferably, the compound of general formula M is 【Chemistry 64】 and any one or a combination of at least two compounds having the structure: The liquid crystal composition according to any one of claims 1 to 8, characterized in that the weight percentage of the compound of general formula M in the liquid crystal composition is preferably 20% to 80%, more preferably 40% to 68%.

10. A liquid crystal display device comprising the liquid crystal composition according to any one of claims 1 to 9.

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