Liquid crystal composition with high transmittance and liquid crystal display device thereof

Abstract

The present invention discloses a liquid crystal composition with high transmittance and a liquid crystal display device thereof. The liquid crystal composition of the present invention 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. The present invention also discloses a liquid crystal display device comprising the liquid crystal composition. While maintaining appropriate rotational viscosity, optical anisotropy, and clearing point, the liquid crystal composition of the present invention also has a large average elastic constant. The liquid crystal molecules of the liquid crystal composition exhibit good order, a large perpendicular dielectric to dielectric ratio, and high transmittance. As a result, the liquid crystal display device comprising the composition has a faster response speed, higher contrast and transmittance, a lower threshold voltage, and reduced energy consumption of the liquid crystal display device. The composition is a liquid crystal material with better overall performance and is particularly suitable for liquid crystal display devices in display modes such as IPS. #imgabs0#

Description

Technical Field

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

[0002] Liquid Crystal Displays (LCDs) have experienced rapid development due to their small size, light weight, low power consumption, and excellent display quality, and have been widely used, particularly in portable electronic information products. However, several challenges remain in their application, such as improving viewing angle characteristics, increasing response speed, increasing contrast, and enhancing transmittance. The narrow viewing angle of LCDs means that contrast decreases significantly when viewed away from the normal to the liquid crystal cell. Wide viewing angles can also cause grayscale and color inversion, severely impacting LCD display quality. Therefore, viewing angle issues are a pressing issue in LCD applications that need to be addressed.

[0003] Currently, many methods have been proposed to address viewing angle issues, including optically compensated bend (OCB) mode, in-plane switching (IPS) mode, fringe field switching (FFS) mode, and multi-vertical alignment (MVA) mode. Each has its own advantages and disadvantages: the MVA mode offers high contrast and fast response, but requires a biaxial compensation film and two elliptically polarized filters, leading to high costs. The OCB mode is difficult to maintain stable control using AC voltage, and the transmittance of the three monochromatic colors (R, G, and B) varies. Furthermore, in the absence of a field, the molecules within the liquid crystal cell are aligned parallel to the substrates. To achieve the bend alignment, a voltage must be applied to the cell for several seconds to pre-set the alignment, which can then be maintained at a lower voltage, making it inconvenient. The IPS mode requires only linear polarizers and no compensation films, but its response speed is too slow to display fast-moving images. Since IPS mode and FFS mode are easy to manufacture and have a wide viewing angle, they have become the most attractive methods to improve viewing angle characteristics and realize large-area display.

[0004] In the early 1970s, experimental research on the basic electro-optical properties of uniformly and twistedly aligned nematic liquid crystals (IPS) mode was conducted. This mode is characterized by a pair of electrodes fabricated on the same substrate, while the other substrate is electrodeless. A transverse electric field applied between the pair of electrodes controls the alignment of the liquid crystal molecules, hence the name "transverse field mode." In IPS mode, the nematic liquid crystal molecules are uniformly aligned parallel to each other between the two substrates, with two polarizers positioned orthogonally. In the IPS mode, when no electric field is applied, incident light is blocked by the two orthogonal polarizers, resulting in a dark state. However, when an electric field is applied, the liquid crystal molecules rotate, causing a delay, allowing light to leak through the two orthogonal polarizers. The advantages of IPS mode LCD panels are wide viewing angles and accurate color reproduction, but the disadvantages are severe light leakage and slow response speeds.

[0005] IPS mode display devices can use either positive or negative liquid crystals. Since the driving voltage required to achieve 100% transmittance decreases as the absolute value of Δε increases, the driving voltage required to achieve 100% transmittance for positive liquid crystals is lower than that for negative liquid crystals, and the response speed is faster. However, negative liquid crystals have better transmittance than positive liquid crystals. This is mainly due to the different arrangement of liquid crystal molecules in the liquid crystal cell in positive and negative IPS modes, resulting in different arrangement and rotation of the liquid crystal molecules when power is applied. Due to the influence of the vertical electric field at the edge, the effective Δn*d of positive liquid crystal molecules decreases, so under power-on conditions, the transmittance of the positive IPS mode is lower than that of the negative IPS mode. Given that the response speed is very slow when using negative liquid crystals, there is an urgent need to maximize the transmittance in the positive IPS mode.

[0006] According to the transmittance formula of IPS mode, Tansmittance (transmittance, T) ∝ |Δε| / ε ⊥ (where “∝” represents the “inverse proportional” relationship, Δε represents dielectric anisotropy, and ε ⊥ Indicates the dielectric constant perpendicular to the molecular axis). To improve the transmittance of positive liquid crystals, one can try to reduce the Δε of the liquid crystal medium, but generally the adjustment range of the driving voltage of the same product is limited. In addition, the liquid crystal molecules will tilt toward the Z axis under the action of the vertical component of the fringe electric field, causing their optical anisotropy Δn to change. According to the formula (where χ is the angle between the optical axis of the liquid crystal layer and the optical axis of the polarizer, Δn is the optical anisotropy, d is the cell spacing, and λ is the wavelength.) It can be seen that the effective Δn*d will affect T. To increase the transmittance of positive liquid crystals, increasing Δn*d can also be considered, but the delay design for each product is fixed.

[0007] On the other hand, based on traditional IPS-LCD light leakage performance tests, technicians in this field have found that the main causes of light leakage problems in liquid crystal display devices are: light scattering (LC scattering), rubbing uniformity, color filter film leakage (CF / TFT scattering) and polarization ability. Among them, light scattering accounts for 63% of the factors affecting light leakage performance.

[0008] According to the following relationship:

[0009] Where d represents the spacing of the liquid crystal cell, n e represents the extraordinary refractive index, n o represents the ordinary refractive index.

[0010] To improve the light scattering of liquid crystal materials, it is necessary to increase the average elastic constant K ave (in, (K 11 +K 22 +K 33 )) to improve light scattering, while increasing K ave In this case, light leakage from the liquid crystal material can be reduced.

[0011] In addition, the relationship between contrast (CR) and brightness (L) is as follows:

[0012] CR=L 255 / L0×100%,

[0013] Among them, L 255 L0 represents the brightness in the on-state, and L0 represents the brightness in the off-state. It can be seen that the change in L0 significantly affects CR. In the off-state, L0 is not related to the dielectric properties of the liquid crystal molecules, but rather to the LC scattering of the liquid crystal material itself. The smaller the LC scattering, the smaller L0, and thus the significantly improved CR.

[0014] In view of the above situation, the common methods for improving the transmittance of liquid crystal materials in the positive IPS mode can be considered from the following two aspects: (1) keeping the dielectric anisotropy Δε of the liquid crystal composition unchanged by increasing ε ⊥ It can effectively improve the transmittance; (2) increase the value of the elastic constant K of the liquid crystal composition, so that the order of the liquid crystal molecules is better and the light leakage is less, thereby improving the transmittance.

[0015] CN106085460A discloses a technical solution for mixing positive and negative liquid crystals, but the solution does not mention the effect of doping a small amount of negative liquid crystal monomers in the positive liquid crystal mixture on the transmittance improvement of IPS mode liquid crystal display devices. In order to maintain a sufficiently high transmittance, the absolute values of the dielectric anisotropy of most liquid crystal compositions in the prior art are relatively low, which leads to a high threshold voltage of the liquid crystal display device containing such a liquid crystal composition, and the direct result is that the energy-saving and environmental protection performance of the liquid crystal display device is affected. However, since the liquid crystal molecules of the liquid crystal composition with a lower threshold voltage usually contain large dielectric polar groups, the order of the liquid crystal molecules will be reduced, and the value of the elastic constant K will also be reduced, thereby affecting the light leakage and contrast of the liquid crystal material, and the two are usually difficult to take into account. Among the liquid crystal materials with lower power consumption currently known, the value of the elastic constant K is not large enough, ε ⊥ The / △ε ratio is not high, resulting in insufficient penetration and slow response speed, making it unsuitable for use in some automotive products that require high contrast. Summary of the Invention

[0016] Purpose of the invention: In view of the defects of the prior art, the purpose of the present invention is to provide a liquid crystal composition and a liquid crystal display device containing the same. The liquid crystal composition of the present invention has a larger average elastic constant, a larger perpendicular dielectric to dielectric ratio and a higher transmittance while maintaining appropriate rotational viscosity, optical anisotropy and clearing point, so that the liquid crystal display device containing it has a faster response speed, higher contrast and transmittance, lower threshold voltage and lower energy consumption.

[0017] The technical solution of the present invention:

[0018] In order to achieve the above-mentioned object of the invention, the present invention provides a liquid crystal composition with high transmittance, the liquid crystal composition of the present invention comprising:

[0019] At least one compound of formula I

[0020]

[0021] At least one compound of formula II

[0022] as well as

[0023] At least one compound of formula III

[0024]

[0025] in,

[0026] R1 represents a straight or branched alkyl group containing 1 to 12 carbon atoms, The straight or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight or branched alkyl group containing 1 to 12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl;

[0027] R2, R3, R4 and R5 each independently represent a linear or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- groups in the linear or branched alkyl group containing 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0028] ring and Ring Each independently expresses in, 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. One or more -H in the ring may be replaced by -CN, -F or -Cl, and one or more -CH= in the ring may be replaced by -N=;

[0029] ring express n1 and n2 each independently represent 0 or 1;

[0030] L1, L2, L3, L4 and L5 are the same or different and each independently represents -H, -F or -CH3;

[0031] X1 represents a halogen, a haloalkyl group or a haloalkoxy group having 1 to 5 carbon atoms, or a haloalkenyl group or a haloalkenyloxy group having 2 to 5 carbon atoms.

[0032] In some embodiments of the present invention, the compound of formula I accounts for 0.1-40% by weight of the total weight of the liquid crystal composition.

[0033] Regarding the preferred content of the compound of formula I: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula I is: 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 22%, 24%, 24.5%, 25%, 25.5%, 26%, 27%, 28%, 30%, 33%, 35%, 37%, 40%. As well as specific values between the above points, due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the above ranges.

[0034] In some embodiments of the present invention, in the compound of general formula I, R1 is preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 8 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 8 carbon atoms; further preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 5 carbon atoms.

[0035] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0036]

[0037]

[0038] as well as

[0039]

[0040] in,

[0041] R1 represents a straight chain alkyl group containing 1 to 5 carbon atoms,

[0042] X1 represents -F, -Cl, a haloalkyl group or a haloalkoxy group having 1 to 3 carbon atoms, or a haloalkenyl group or a haloalkenyloxy group having 2 to 3 carbon atoms.

[0043] In some embodiments of the present invention, the compound of formula I is preferably a compound wherein X1 represents -F, -CF3, or -OCF3, and further preferably a compound wherein X1 represents -F.

[0044] In some embodiments of the present invention, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula I-5, and further preferably contains at least two compounds of the general formula I-5.

[0045] In some embodiments of the present invention, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula I-6, and further preferably contains at least two compounds of the general formula I-6.

[0046] In some embodiments of the present invention, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula I-5 and at least one compound of the general formula I-6.

[0047] In some embodiments of the present invention, the compound of formula II accounts for 0.1-20% by weight of the total weight of the liquid crystal composition.

[0048] Regarding the preferred content of the compound of formula II: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula II is: 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%. As well as specific values between the above points, due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the above ranges.

[0049] In some embodiments of the present invention, in the compound of general formula II, R2 and R3 are each independently preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 8 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 8 carbon atoms; further preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 5 carbon atoms.

[0050] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0051]

[0052] as well as

[0053]

[0054] In some embodiments of the present invention, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula II-1.

[0055] In some embodiments of the present invention, in order to obtain a relatively higher ε ⊥ and lower rotational viscosity, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula II-1 and at least one compound of the general formula II-2 or II-3.

[0056] In some embodiments of the present invention, the compound of formula III accounts for 0.1-40% by weight of the total weight of the liquid crystal composition.

[0057] Regarding the preferred content of the compound of formula III: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula III is: 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 22%, 24%, 24.5%, 25%, 25.5%, 26%, 27%, 28%, 30%, 33%, 35%, 37%, 40%. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the above ranges.

[0058] In some embodiments of the present invention, in the compound of formula III, R4 and R5 are each independently preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 8 carbon atoms, or a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 8 carbon atoms; further preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms, or a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 5 carbon atoms. Even more preferably, R4 preferably represents a straight-chain or branched alkyl group containing 1 to 5 carbon atoms, and R5 preferably represents a straight-chain or branched alkoxy group containing 1 to 5 carbon atoms.

[0059] In some embodiments of the present invention, in the compound of formula III, the ring Preferably expressed as

[0060] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0061]

[0062]

[0063] In some embodiments of the present invention, in order to obtain relatively higher △n, lower rotational viscosity and wider operating temperature range, the liquid crystal composition of the present invention preferably contains at least one compound of general formula III-3, and further preferably contains at least two compounds of general formula III-3.

[0064] In some embodiments of the present invention, the liquid crystal composition of the present invention preferably contains at least one compound of the general formula III-1 and at least one compound of the general formula III-3.

[0065] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of formula M:

[0066]

[0067] in,

[0068] R M1 and R M2 Each independently represents -H, a linear or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- groups in the linear or branched alkyl group containing 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0069] ring ring and Ring Each independently expresses in, One or more -CH2- in may be replaced by -O-, In one or at least two rings, -CH= may be replaced by -N=, and at most one -H may be replaced by halogen;

[0070] Z M1 and Z M2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2- or -(CH2)4-;

[0071] n M1 represents 0, 1, 2, or 3, and when n M1 =2 or 3, the ring Can be the same or different, Z M2 Can be the same or different.

[0072] In some embodiments of the present invention, the content of the compound of formula M must be appropriately adjusted depending on the required properties such as solubility at low temperatures, transition temperature, electrical reliability, birefringence, process adaptability, drop marks, screen burn-in, and dielectric anisotropy.

[0073] In some embodiments of the present invention, the compound of formula M accounts for 0.1% to 80% of the total weight of the liquid crystal composition.

[0074] Regarding the preferred content of the compound of formula M: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula M is: 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%, 68%, 70%, 72%, 75%, 78%, 80%. As well as specific values between the above points, due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the above ranges.

[0075] In some embodiments of the present invention, in the compound of formula M, R M1 and R M2 Each independently represents preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 8 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 8 carbon atoms; more preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 5 carbon atoms.

[0076] In some embodiments of the present invention, R M1 and R M2 One of them preferably represents a straight-chain alkyl group containing 1 to 5 carbon atoms, and the other preferably represents a straight-chain alkenyl group containing 2 to 5 carbon atoms.

[0077] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of:

[0078]

[0079]

[0080] as well as

[0081]

[0082] In some embodiments of the present invention, the compound of formula M is preferably selected from any one or a combination of at least two of the compounds of formula M-1, M-3, M-7 or M-11.

[0083] In the present invention, while maintaining appropriate optical anisotropy, appropriate clearing point, larger average elastic constant, smaller rotational viscosity, and higher transmittance, in order to simultaneously take into account a larger perpendicular dielectric to dielectric ratio and a larger dielectric anisotropy, the liquid crystal composition of the present invention preferably contains at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula M.

[0084] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of the general formula N:

[0085]

[0086] in,

[0087] R N1 and R N2 Each independently represents a linear or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- groups in the linear or branched alkyl group containing 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0088] ring and Ring Each independently expresses in, 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. One or more -H in the ring may be replaced by -CN, -F or -Cl, and one or more -CH= in the ring may be replaced by -N=;

[0089] Z N1 and Z N2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -(CH2)4-, -CF2O-, -OCF2- or -CF2CF2-;

[0090] n N1 Indicates 0, 1, 2, or 3, n N2 Represents 0 or 1, and 0≤n N1 +n N2 ≤3, and when n N1 =2 or 3, the ring Can be the same or different, Z N1 Can be the same or different;

[0091] The compound of the general formula N satisfies the following two conditions:

[0092] a: when n N1 =1, n N2 = 0, the ring Not for And the ring for When R N1 Not an alkoxy group;

[0093] b: When n N1 =2, n N2 = 0, does not contain rings One is The other is situation.

[0094] In some embodiments of the present invention, the compound of formula N accounts for 0.1% to 40% of the total weight of the liquid crystal composition.

[0095] Regarding the preferred content of the compound of formula N: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula N is: 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the aforementioned ranges.

[0096] In some embodiments of the present invention, in the compound of formula N, R N1 and R N2 Each is independently preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 8 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 8 carbon atoms; further preferably a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms, a straight-chain or branched alkenyl or alkenyloxy group containing 2 to 5 carbon atoms.

[0097] In some embodiments of the present invention, the compound of formula N is selected from the group consisting of:

[0098]

[0099]

[0100]

[0101] as well as

[0102]

[0103] In some embodiments of the present invention, the compound of formula N is preferably selected from any one or a combination of at least two of the compounds of formula N-1, N-4, N-9 or N-11.

[0104] In the present invention, in order to obtain a larger ratio of perpendicular dielectric to dielectric while maintaining appropriate optical anisotropy, an appropriate clearing point, a larger average elastic constant, a smaller rotational viscosity, and a higher transmittance, the liquid crystal composition of the present invention preferably contains at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, at least one compound of general formula M, and at least one compound of general formula N.

[0105] In some embodiments of the present invention, in order to better apply the liquid crystal composition to a high-transmittance liquid crystal display device, the liquid crystal composition of the present invention further comprises any one or a combination of at least two compounds selected from the group consisting of the compounds of formula A-1 or formula A-2, wherein the compound of formula A-1 and / or the compound of formula A-2 has positive dielectric anisotropy:

[0106]

[0107] in,

[0108] R A11 and R A21 Each independently represents a linear or branched alkyl group containing 1 to 12 carbon atoms, The straight or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight or branched alkyl group containing 1 to 12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl;

[0109] ring ring ring and Ring Each independently expresses in, One or more -CH2- in the ring may be replaced by -O-, and the single bonds in one or at least two rings may be replaced by double bonds; One or more -H in the ring may be replaced by -CN, -F or -Cl, and one or more -CH= in the ring may be replaced by -N=;

[0110] 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-, -CH2O- or -OCH2-;

[0111] L A11 , L A12 , L A13 , L A21 and L A22 Each independently represents -H, -F or -CH3;

[0112] X A1 and X A2 Each independently represents halogen, a haloalkyl or haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl or haloalkenyloxy group containing 2 to 5 carbon atoms;

[0113] n A1 and n A2 Each independently represents 0, 1, 2 or 3, and when n A1 =2 or 3, the ring Can be the same or different, Z A11 Can be the same or different, when n A2 =2 or 3, the ring Can be the same or different, Z A21 Can be the same or different;

[0114] The compound of the general formula A-1 satisfies the following conditions:

[0115] When n A1 =2 and has a ring for The compound of general formula A-1 does not contain a biphenyl structure.

[0116] In the present invention, the biphenyl structure includes a biphenyl structure with or without a substituent, for example etc., which are not listed here one by one.

[0117] In some embodiments of the present invention, the compound of formula A-1 is selected from the group consisting of:

[0118]

[0119]

[0120]

[0121]

[0122] as well as

[0123] In some embodiments of the present invention, the compound of formula A-2 is selected from the group consisting of:

[0124]

[0125]

[0126]

[0127]

[0128] as well as

[0129] in,

[0130] R A11 and R A21 Each independently represents a straight-chain or branched alkyl group containing 1 to 8 carbon atoms, and one or more non-adjacent -CH2- in the straight-chain or branched alkyl group containing 1 to 8 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-.

[0131] X A1 and X A2 Each independently represents -F, -CF3, -OCF3 or -(CH2)2-CH=CF2.

[0132] In some embodiments of the present invention, the compound of formula A-1 accounts for 0.1% to 50% of the total weight of the liquid crystal composition.

[0133] Regarding the preferred content of the compound of formula A-1: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula A-1 is: 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the aforementioned ranges.

[0134] In some embodiments of the present invention, the compound of formula A-2 accounts for 0.1% to 50% of the total weight of the liquid crystal composition.

[0135] Regarding the preferred content of the compound of formula A-2: relative to the total weight of the liquid crystal composition of the present invention, the preferred content of the compound of formula A-2 is: 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%. Due to space limitations and for the sake of brevity, the present invention does not exhaustively list the specific values included in the aforementioned ranges.

[0136] In some embodiments of the present invention, the compound selected from the group consisting of compounds of Formula A-1 and Formula A-2 accounts for 0.1% to 60% by weight of the liquid crystal composition.

[0137] Regarding the preferred content of the compound selected from the group consisting of compounds of formula A-1 and formula A-2: relative to the total weight of the liquid crystal composition of the present invention, its content is 0.1%, 1%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%. Due to space limitations and for the sake of brevity, the present invention does not exhaustively enumerate the specific values included in the above ranges.

[0138] In the present invention, in order to obtain a larger dielectric anisotropy while having a larger ratio of perpendicular dielectric to dielectric while maintaining appropriate optical anisotropy, appropriate clearing point, larger average elastic constant, smaller rotational viscosity, and higher transmittance, the liquid crystal composition of the present invention preferably contains at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, at least one compound of general formula M, at least one compound of general formula N, and at least one compound selected from any one or a combination of at least two of the compounds of general formula A-1 or general formula A-2.

[0139] The alkenyl group in the present invention is preferably selected from the group represented by any one of formulas (V1) to (V9), and is particularly preferably represented by formula (V1), formula (V2), formula (V8), or formula (V9). The groups represented by formulas (V1) to (V9) are as follows:

[0140]

[0141] Here, * represents the carbon atom in the ring structure to which it is bonded.

[0142] The alkenyloxy group in the present invention is preferably selected from a group represented by any one of Formula (OV1) to Formula (OV9), and is particularly preferably Formula (OV1), Formula (OV2), Formula (OV8), or Formula (OV9). The groups represented by Formula (OV1) to Formula (OV9) are as follows:

[0143]

[0144] Here, * represents the carbon atom in the ring structure to which it is bonded.

[0145] In addition to the above-mentioned compounds, the liquid crystal composition of the present invention may also contain common nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, antioxidants, ultraviolet absorbers, infrared absorbers, polymerizable monomers, or light stabilizers.

[0146] Possible dopants which are preferably added to the liquid-crystal composition according to the invention are shown below.

[0147]

[0148]

[0149] as well as

[0150]

[0151] In some embodiments of the present invention, preferably, the dopant accounts for 0-5% of the total weight of the liquid crystal composition; more preferably, the dopant accounts for 0-1% of the total weight of the liquid crystal composition.

[0152] In addition, the antioxidants, light stabilizers and other additives used in the liquid crystal composition of the present invention are preferably the following:

[0153]

[0154]

[0155]

[0156]

[0157] Here, n represents a positive integer from 1 to 12.

[0158] Preferably, the light stabilizer is selected from the light stabilizers shown below:

[0159]

[0160] In some embodiments of the present invention, preferably, the light stabilizer accounts for 0-5% of the total weight of the liquid crystal composition; more preferably, the light stabilizer accounts for 0-1% of the total weight of the liquid crystal composition; particularly preferably, the light stabilizer accounts for 0-0.1% of the total weight of the liquid crystal composition.

[0161] Another aspect of the present invention provides a liquid crystal display device comprising the liquid crystal composition.

[0162] Beneficial effects:

[0163] The liquid crystal composition provided by the present invention has a large average elastic constant, a large perpendicular dielectric to dielectric ratio, and a high transmittance while maintaining appropriate rotational viscosity, optical anisotropy, and clearing point through the mutual synergy of the compound of formula I, the compound of general formula II, and the compound of general formula III. As a result, a liquid crystal display device containing the liquid crystal composition has a faster response speed, higher contrast and transmittance, and a lower threshold voltage, thereby reducing the energy consumption of the liquid crystal display device. The liquid crystal composition is a liquid crystal material with better overall performance and is particularly suitable for liquid crystal display devices in display modes such as IPS. DETAILED DESCRIPTION

[0164] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0165] The liquid crystal displays used in the following embodiments are all TFT liquid crystal display devices, with a cell thickness d=7 μm (unless otherwise specified).

[0166] For ease of expression, in the following embodiments, the group structures of the liquid crystal compositions are represented by the codes listed in Table 1:

[0167] Table 1 Group structure codes of liquid crystal compounds

[0168]

[0169] Take the following compound as an example:

[0170]

[0171] 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.

[0172] The abbreviated codes for the test items in the following embodiments are as follows:

[0173] Cp clearing point (nematic-isotropic phase transition temperature, °C)

[0174] Δn optical anisotropy (589nm, 25℃)

[0175] Δε dielectric anisotropy (1KHz, 25℃)

[0176] ε ⊥ Dielectric constant perpendicular to the molecular axis

[0177] K ave Average elastic constant

[0178] T penetration rate (%)

[0179] γ1 Torsional viscosity (mPa*s, at 25°C)

[0180] in,

[0181] Cp: obtained by melting point test.

[0182] Δn: measured using an Abbe refractometer under a sodium lamp (589 nm) at 25°C.

[0183] Δε=ε ∥ -ε ⊥ , where ε ∥ is the dielectric constant parallel to the molecular axis, ε ⊥ is the dielectric constant perpendicular to the molecular axis. Test conditions: 25°C, 1 kHz, TN90 test box, 7 μm thickness.

[0184] where K 11 , K 22 , K 33 It is calculated by testing the CV curve of liquid crystal using an LCR meter and an anti-parallel friction cell. The test conditions are: 7μm anti-parallel friction cell, V = 0.1~20V.

[0185] T: The transmittance of the dimming device is tested using a DMS 505 tester. The cell thickness of the dimming device is 5.2μm.

[0186] γ1: Measured using the LCM-2 liquid crystal property evaluation system; test conditions: 25°C, 160V-260V, test box thickness 20μm.

[0187] The components used in the following examples can be synthesized by known methods or obtained through commercial channels. These synthesis techniques are conventional, and the obtained liquid crystal compounds meet the standards of electronic compounds after testing.

[0188] Liquid crystal compositions were prepared according to the ratios of the liquid crystal compositions specified in the following examples. The liquid crystal compositions were prepared according to conventional methods in the art, such as mixing in a specified ratio using heating, ultrasonic waves, suspension, etc.

[0189] The liquid crystal compositions given in the following examples were prepared and studied. The composition of each liquid crystal composition and the test results of its performance parameters are shown below.

[0190] Comparative Example 1

[0191] The liquid crystal composition of Comparative Example 1 was prepared according to the compounds and weight percentages listed in Table 2, and filled between two substrates of a liquid crystal display for performance testing.

[0192] Table 2 Liquid crystal composition formula and performance parameter test

[0193]

[0194]

[0195] Example 1

[0196] The liquid crystal composition of Example 1 was prepared according to the compounds and weight percentages listed in Table 3, and filled between two substrates of a liquid crystal display for performance testing.

[0197] Table 3 Liquid crystal composition formula and performance parameter test

[0198]

[0199] Example 2

[0200] The liquid crystal composition of Example 2 was prepared according to the compounds and weight percentages listed in Table 4, and filled between two substrates of a liquid crystal display for performance testing.

[0201] Table 4 Liquid crystal composition formula and performance parameter test

[0202]

[0203]

[0204] Comparative Example 2

[0205] The liquid crystal composition of Comparative Example 2 was prepared according to the compounds and weight percentages listed in Table 5, and filled between two substrates of a liquid crystal display for performance testing.

[0206] Table 5 Liquid crystal composition formula and performance parameter test

[0207]

[0208] Example 3

[0209] The liquid crystal composition of Example 3 was prepared according to the compounds and weight percentages listed in Table 6, and filled between two substrates of a liquid crystal display for performance testing.

[0210] Table 6 Liquid crystal composition formula and performance parameter test

[0211]

[0212] Example 4

[0213] The liquid crystal composition of Example 4 was prepared according to the compounds and weight percentages listed in Table 7, and filled between two substrates of a liquid crystal display for performance testing.

[0214] Table 7 Liquid crystal composition formula and performance parameter test

[0215]

[0216]

[0217] Example 5

[0218] The liquid crystal composition of Example 5 was prepared according to the compounds and weight percentages listed in Table 8, and filled between two substrates of a liquid crystal display for performance testing.

[0219] Table 8 Liquid crystal composition formula and performance parameter test

[0220]

[0221] Example 6

[0222] The liquid crystal composition of Example 6 was prepared according to the compounds and weight percentages listed in Table 9, and filled between two substrates of a liquid crystal display for performance testing.

[0223] Table 9 Liquid crystal composition formula and performance parameter test

[0224]

[0225]

[0226] Example 7

[0227] The liquid crystal composition of Example 7 was prepared according to the compounds and weight percentages listed in Table 10, and filled between two substrates of a liquid crystal display for performance testing.

[0228] Table 10 Liquid crystal composition formula and performance parameter test

[0229]

[0230] Example 8

[0231] The liquid crystal composition of Example 8 was prepared according to the compounds and weight percentages listed in Table 11, and filled between two substrates of a liquid crystal display for performance testing.

[0232] Table 11 Liquid crystal composition formula and performance parameter test

[0233]

[0234] Example 9

[0235] The liquid crystal composition of Example 9 was prepared according to the compounds and weight percentages listed in Table 12, and filled between two substrates of a liquid crystal display for performance testing.

[0236] Table 12 Liquid crystal composition formula and performance parameter test

[0237]

[0238]

[0239] Example 10

[0240] The liquid crystal composition of Example 10 was prepared according to the compounds and weight percentages listed in Table 13, and filled between two substrates of a liquid crystal display for performance testing.

[0241] Table 13 Liquid crystal composition formula and performance parameter test

[0242]

[0243] Example 11

[0244] The liquid crystal composition of Example 11 was prepared according to the compounds and weight percentages listed in Table 14, and filled between two substrates of a liquid crystal display for performance testing.

[0245] Table 14 Liquid crystal composition formula and performance parameter test

[0246]

[0247]

[0248] From the comparison between Comparative Example 1 and Example 1, it can be seen that the combination of the compound of Formula I and the compound of Formula II in the present invention has a synergistic effect. While maintaining appropriate rotational viscosity, optical anisotropy and clearing point, the average elastic constant of the composition can be significantly improved (Kave value increased from 10.7 to 11.2), a larger perpendicular dielectric to dielectric ratio (ε ⊥ / Δε value increased from 0.99 to 1.06) and transmittance value (T value increased from 15.5 to 15.9); Comparison between Comparative Example 2 and Example 3 shows that the combination of the compound of Formula II and the compound of Formula III in the present invention has a synergistic effect, which can significantly improve the average elastic constant (K ave value increased from 11.6 to 12.3), a larger ratio of vertical dielectric to dielectric (ε ⊥ / Δε value increased from 1.23 to 1.32) and transmittance value (T value increased from 15.6 to 16.2).

[0249] In summary, the liquid crystal composition provided by the present invention has a large average elastic constant (K ave value ≥11.2), the liquid crystal molecules of the liquid crystal composition have good order, and the ratio of vertical dielectric to dielectric (ε ⊥ / Δε value is between 1.06-3.67), and high transmittance (T value is between 15.7-17.8%), so that the liquid crystal display device containing it has a faster response speed, higher contrast and transmittance, lower threshold voltage, and reduces the energy consumption of the liquid crystal display device. It is a liquid crystal material with better comprehensive performance and is particularly suitable for liquid crystal display devices with display modes such as IPS.

[0250] The above embodiments are only for illustrating the technical concept and features of the present invention. Its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. It cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A liquid crystal composition with high transmittance, comprising: At least one compound of formula I At least one compound of formula II as well as At least one compound of formula III in, R1 represents a straight or branched alkyl group containing 1 to 12 carbon atoms, The straight or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight or branched alkyl group containing 1 to 12 carbon atoms, One or more -H in can be independently replaced by -F or -Cl; R2, R3, R4 and R5 each independently represent a linear or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- groups in the linear or branched alkyl group containing 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; ring and Ring Each independently expresses in, 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. One or more -H in the ring may be replaced by -CN, -F or -Cl, and one or more -CH= in the ring may be replaced by -N=; ring express n1 and n2 each independently represent 0 or 1; L1, L2, L3, L4 and L5 are the same or different and each independently represents -H, -F or -CH3; X1 represents a halogen, a haloalkyl group or a haloalkoxy group having 1 to 5 carbon atoms, or a haloalkenyl group or a haloalkenyloxy group having 2 to 5 carbon atoms.

2. The liquid crystal composition with high transmittance according to claim 1, characterized in that: The compound of formula I accounts for 0.1-40% of the total weight of the liquid crystal composition.

3. The liquid crystal composition with high transmittance according to claim 1, wherein: The compound of formula I is selected from the group consisting of the following compounds: as well as in, R1 represents a straight chain alkyl group containing 1 to 5 carbon atoms, X1 represents -F, -Cl, a haloalkyl group or a haloalkoxy group having 1 to 3 carbon atoms, or a haloalkenyl group or a haloalkenyloxy group having 2 to 3 carbon atoms.

4. The liquid crystal composition with high transmittance according to claim 3, wherein: The liquid crystal composition includes at least one compound of the general formula I-5 and at least one compound of the general formula I-6.

5. The liquid crystal composition with high transmittance according to claim 1, wherein The compound of formula II accounts for 0.1-20% of the total weight of the liquid crystal composition.

6. The liquid crystal composition with high transmittance according to claim 1, wherein The compound of formula II is selected from the group consisting of the following compounds: as well as 7. The liquid crystal composition with high transmittance according to claim 1, wherein The compound of formula III accounts for 0.1-40% of the total weight of the liquid crystal composition.

8. The liquid crystal composition with high transmittance according to claim 1, wherein The compound of formula III is selected from the group consisting of:

9. The liquid crystal composition with high transmittance according to claim 1, wherein The liquid crystal composition further comprises any one or a combination of at least two compounds selected from the group consisting of the compounds of formula A-1 or formula A-2, wherein the compound of formula A-1 and / or the compound of formula A-2 has positive dielectric anisotropy: in, R A11 and R A21 Each independently represents a linear or branched alkyl group containing 1 to 12 carbon atoms, The straight or branched alkyl group containing 1 to 12 carbon atoms, One or more non-adjacent -CH2- can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and the straight or branched alkyl group containing 1 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 in, One or more -CH2- in the ring may be replaced by -O-, and the single bonds in one or at least two rings may be replaced by double bonds; One or more -H in the ring may be replaced by -CN, -F or -Cl, and one or more -CH= in the ring may 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-, -CH2O- or -OCH2-; L A11 、L A12 、L A13 、L A21 and L A22 Each independently represents -H, -F or -CH3; X A1 and X A2 Each independently represents halogen, a haloalkyl or haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl or haloalkenyloxy group containing 2 to 5 carbon atoms; n A1 and n A2 Each independently represents 0, 1, 2 or 3, and when n A1 =2 or 3, the ring Can be the same or different, Z A11 Can be the same or different, when n A2 =2 or 3, the ring Can be the same or different, Z A21 Can be the same or different; The compound of the general formula A-1 satisfies the following conditions: When n A1 =2 and has a ring for The compound of general formula A-1 does not contain a biphenyl structure.

10. 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 9.

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