Liquid crystal composition and liquid crystal display device comprising same

Abstract

The invention provides a liquid crystal composition and a liquid crystal display device comprising the same. The liquid crystal composition comprises at least one compound shown in the formula I and at least one stabilizer. A stabilizer with a specific structure is compounded with a compound which has a dibenzo structure and is shown in a formula I, so that on the basis of maintaining a proper clearing point, optical anisotropy and dielectric anisotropy, the optical anisotropy and dielectric anisotropy of the liquid crystal composition are improved; the liquid crystal composition has the advantages of high elastic constants K11 and K33, low rotary viscosity gamma 1, short response time RT, fast response speed, high penetration rate Tr, high contrast ratio CR, good low-temperature storage stability, wide nematic phase temperature range, reduction of image viscous residue or acceleration of dissipation of image residue, high voltage holding ratio VHR, and good application prospects. The overall using effect of the liquid crystal material can be improved, and the liquid crystal material is suitable for fast-response VA, PSVA, IPS, NFFS and other display modes.

Description

Technical Field

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

[0002] Liquid Crystal Displays (LCDs) have developed rapidly due to their small size, light weight, low power consumption and excellent display quality, and have been widely used especially in portable electronic information products. With the increase in the size of liquid crystal screens for portable computers, office applications and video applications, liquid crystal displays can be used for large-screen displays and finally replace Cathode Ray Tube (CRT) displays.

[0003] Compared with traditional display devices and display materials, liquid crystal display materials have the following obvious advantages: low driving voltage, tiny power consumption, high reliability, large amount of display information, color display, no flicker, harmless to the human body, automated production process, low cost, can be made into various specifications and types of liquid crystal displays, easy to carry, etc. Due to these advantages, liquid crystal display technology has had a profound impact on the field of display and imaging, and promoted the development of microelectronics technology and optoelectronic information technology. Liquid crystal materials have been widely used in many display occasions due to their good optical properties and photoelectric effects.

[0004] Dibenzene compounds are a relatively novel type of liquid crystal monomer materials in recent years, where R and R' represent hydrogen atom, alkyl group, cycloalkyl group, alkoxy group, tetrahydrofuran group, tetrahydrothiophene group, etc.; M represents oxygen atom or sulfur atom. Due to their characteristic benzofuran or benzothiophene structures, dibenzene compounds have advantages such as large elastic constants, large dielectric constants and stable structures, and can provide very excellent performance in TFT liquid crystals of fast response, high transmittance, high contrast, etc.

[0005] Although dibenzene compounds bring advantages such as lower threshold voltage and faster response time to liquid crystal display devices due to their larger dielectric constants, they have strong electronegativity. When the liquid crystal mixture containing them is exposed to external stresses (especially one drop filling, abbreviated as ODF for one drop filling of liquid crystal droplets), sealant curing, UV / backlight irradiation and other conditions, it is easy to adsorb impurity ions in the device, free radicals in the polyimide alignment layer, etc., resulting in a decrease in the reliability of the liquid crystal mixture such as specific resistance and Voltage Holding Ratio (VHR), and situations such as image sticking, not easy to dissipate, and image residue occur after a long power-on operation time, reducing the stability of the liquid crystal mixture. Therefore, there is an urgent need for a type of liquid crystal material that can take into account the advantages of dibenzene compounds and at the same time make up for the image residue caused by the decrease in liquid crystal reliability due to the influence of external stresses. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the object of the present invention is to provide a liquid crystal composition and a liquid crystal display device comprising the same. On the basis of maintaining appropriate clearing points, optical anisotropy and dielectric anisotropy, the liquid crystal composition has low viscosity, large elastic constants, fast response speed, high transmittance, good low-temperature storage stability, a wider nematic phase temperature range and better contrast, and can eliminate image sticking residues or accelerate the dissipation of image residues.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a liquid crystal composition, which comprises:

[0009] at least one compound of formula I:

[0010] and

[0011] at least one stabilizer selected from the group consisting of the following compounds:

[0012]

[0013] wherein, R1 represents -H, halogen, a straight-chain or branched-chain alkyl group containing 1-12 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, the straight-chain or branched-chain alkyl group containing 1-12 carbon atoms, one or at least two non-adjacent -CH2- therein may be independently replaced by -CH=CH-, -C≡C-, -O-, -S-, -CO-, -CO-O- or -O-CO- respectively, and one or at least two -H in the foregoing groups may be independently replaced by -F or -Cl;

[0014] R2 represents a haloalkyl group containing 1-3 (for example, 1, 2, 3) carbon atoms, wherein one or at most two single bonds in one or more of the rings may be replaced by double bonds;

[0015] ring and ring each independently represents the one or at least two -CH2- therein may be replaced by -O-, one or at most two single bonds in one or more of the rings may be replaced by double bonds; the One or at least two of the -H therein may be replaced by -F, -Cl, -CN, -CH3 or -OCH3, and one or at least two of the -CH= in the rings may be replaced by -N=;

[0016] Z1 and Z2 each independently represent a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0017] Z3 represents a single bond, -O(CH2) a - or -S(CH2) a -; a represents an integer from 0 to 5, for example, it can be 0, 1, 2, 3, 4 or 5;

[0018] L1 and L2 each independently represent -H, halogen, a halogenated or unhalogenated alkyl group containing 1 - 3 (for example, 1, 2, 3) carbon atoms, or a halogenated or unhalogenated alkoxy group containing 1 - 3 (for example, 1, 2, 3) carbon atoms;

[0019] G represents -O-, -S-, -CO-, -CF2-, -NH- or -NF-;

[0020] X represents -H, -OH, -O*, a straight-chain or branched-chain alkyl group containing 1 - 5 (for example, 1, 2, 3, 4, 5) carbon atoms; one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group containing 1 - 5 carbon atoms may be independently replaced by -O- or -CO- respectively; -O* represents an oxygen radical;

[0021] n1 represents 0 or 1;

[0022] n2 represents 0, 1 or 2; when n2 = 2, the rings are the same or different, and Z2 are the same or different;

[0023] n represents an integer from 1 to 20, for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0024] It has been found in the research of the present invention that during the application of an oversaturated voltage, ions in the liquid crystal and the device continuously accumulate near the upper and lower electrode plates under the action of a DC bias voltage. After the power is removed, the internal electric field formed due to the difficulty of ion dissipation causes the liquid crystal to still deflect, and the brightness slowly decreases, forming image retention. The liquid crystal composition provided by the present invention contains at least one stabilizer, and the stabilizer is selected from the group consisting of compounds of formula II-1, compounds of formula II-2, compounds of formula II-3, and compounds of formula II-4. It is a hindered amine light stabilizer that can adsorb ions / free radicals, eliminate the internal electric field, and make the afterimage dissipate quickly. In the present invention, a stabilizer with a specific structure is compounded with a compound of formula I having a dibenzo structure, so that the liquid crystal composition has a higher elastic constant (K 11 and K 33 ), a smaller rotational viscosity γ1, a shorter response time RT, a faster response speed, a higher transmittance Tr, a higher contrast ratio CR, and better low-temperature storage stability on the basis of maintaining an appropriate clearing point, optical anisotropy, and dielectric anisotropy, making the nematic phase temperature range wider, and reducing image viscous residue or accelerating the dissipation of image residue, having a higher voltage holding ratio VHR, which helps to improve the overall use effect of the liquid crystal material and is applicable to fast-response display modes such as VA, PSVA, IPS, and NFFS.

[0025] The following are the preferred technical solutions of the present invention, but do not limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved.

[0026] In the present invention, the 1-12 carbon atoms can each be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 carbon atoms; the 1-3 carbon atoms can each be 1, 2, or 3 carbon atoms; the 1-5 carbon atoms can each be 2, 3, 4, or 5 carbon atoms; the halogen includes F, Cl, Br, or I; when the same description is involved hereinafter, it has the same meaning; the term "halogenated" means that at least 1 -H in the group is replaced by a halogen (-F, -Cl, -Br, or -I); when the same description is involved hereinafter, it has the same meaning; when n2 = 2 in the present invention, there are 2 rings in the compound These two can have the same structure or different structures. Exemplarily, one can be and the other can be When the present invention relates to the expression "same or different", it has the same meaning; in the present invention, "can be independently replaced by..." means that it can be replaced or not replaced, that is, whether it is replaced or not replaced, it belongs to the protection scope of the present invention. The same applies to "can be independently substituted by...", and the positions of "substitution" and "substitution" can be arbitrary; the short straight lines on one or both sides of the group structure represent the access bond and do not represent methyl, for example the short straight line on the left, the short straight lines on both sides.

[0027] In some embodiments of the present invention, G represents -O- or -S-.

[0028] In some embodiments of the present invention, L1 and L2 represent -F.

[0029] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of the following compounds:

[0030]

[0031] and

[0032]

[0033] wherein, R1, R2 and Z3 have the same defined ranges as in formula I;

[0034] Y1 and Y2 each independently represent -O- or -CH2-.

[0035] In some preferred embodiments of the present invention, the compound of formula I is selected from at least one (such as 1, 2, 3, 4, etc.) of the group consisting of the compound of formula I-1 and the compound of formula I-2:

[0036] and

[0037]

[0038] In some embodiments of the present invention, R1 represents a straight-chain alkyl group containing 1-8 (such as 1, 2, 3, 4, 5, 6, 7, 8) carbon atoms or a straight-chain alkoxy group containing 1-6 (such as 1, 2, 3, 4, 5, 6) carbon atoms, and further preferably a straight-chain alkoxy group containing 1-6 carbon atoms.

[0039] In some embodiments of the present invention, Z3 represents a single bond, -O-, -OCH2- or -OCH2CH2-.

[0040] In some embodiments of the present invention, R2 represents a fluoroalkyl group having 1 to 3 carbon atoms, preferably -CF3, more preferably -CF3, even more preferably

[0041] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of the following compounds:

[0042]

[0043]

[0044] and

[0045]

[0046] wherein, R2' represents a halogenated straight-chain alkyl group having 1 to 3 (e.g., 1, 2, 3) carbon atoms, preferably a fluoroalkyl straight-chain alkyl group having 1 to 3 (e.g., 1, 2, 3) carbon atoms, more preferably -CF3;

[0047] ring represents more preferably

[0048] In some embodiments of the present invention, the mass percentage content of the compound of formula I in the liquid crystal composition is 1% - 30%, for example, it can be 3%, 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25% or 28%, etc., preferably 2% - 20%, more preferably 8% - 16%.

[0049] In some embodiments of the present invention, the mass percentage content of at least one (e.g., 1, 2, 3 or 4, etc.) compound of formula I selected from the group consisting of the compound of formula I-1 and the compound of formula I-2 is 1% - 29%, for example, it can be 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 29%, etc., preferably 2% - 20%.

[0050] In some embodiments of the present invention, X represents -H, -OH, -O*, a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, a straight-chain or branched-chain alkoxy group having 1 to 5 carbon atoms, or a straight-chain or branched-chain acyl group having 1 to 5 carbon atoms.

[0051] In some embodiments of the present invention, X represents -H, -OH, -O*, -CH3, -OCH3 or -CO-CH3.

[0052] In some embodiments of the present invention, n represents an integer from 2 to 16, more preferably an integer from 2 to 14.

[0053] In some embodiments of the present invention, the stabilizer comprises at least one compound selected from the group consisting of compounds of formula II-3 and compounds of formula II-4.

[0054] In some embodiments of the present invention, the stabilizer comprises at least one compound selected from the group consisting of compounds of formula II-1 and compounds of formula II-3.

[0055] In some embodiments of the present invention, the stabilizer comprises at least one compound selected from the group consisting of compounds of formula II-1, compounds of formula II-2, compounds of formula II-3, and compounds of formula II-4, wherein X represents -OH, -O*, -CH3, -OCH3 or -CO-CH3.

[0056] In some embodiments of the present invention, the mass percentage content of the stabilizer in the liquid crystal composition is 0.001% - 0.1%, for example, it can be 0.002%, 0.003%, 0.005%, 0.008%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08% or 0.09%, etc., and preferably 0.002% - 0.05%.

[0057] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of formula N:

[0058]

[0059] wherein, R N1 and R N2 each independently represents a straight-chain or branched-chain alkyl group containing 1 to 12 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO- respectively;

[0060] ring and ring each independently represents wherein One or at least two of the -CH2- therein may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, where One or at least two of the -H therein may be independently replaced by -F, -Cl or -CN respectively, and one or at least two of the -CH= in the ring may be replaced by -N=;

[0061] L N1 and L N2 each independently represents -H, a halogen, a straight-chain or branched-chain alkyl group having 1 - 3 (e.g., 1, 2, 3) carbon atoms, or a straight-chain or branched-chain alkoxy group having 1 - 3 (e.g., 1, 2, 3) carbon atoms;

[0062] Z N1 and Z N2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0063] n N1 represents 0, 1, 2 or 3, n N2 represents 0 or 1, and 0 ≤ n N1 +n N2 ≤ 3;

[0064] When n N1 represents 2 or 3, the rings are the same or different, and Z N1 are the same or different.

[0065] In some embodiments of the present invention, the compound of formula N is selected from the group consisting of the following compounds:

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] and

[0072]

[0073] wherein, R N1 and R N2 have the same defined ranges as in formula N.

[0074] In some embodiments of the present invention, the R N1 and R N2 each independently represent a straight-chain alkyl group having 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, a straight-chain alkoxy group having 1 to 9 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9) carbon atoms, or a straight-chain alkenyl group having 2 to 9 (e.g., 2, 3, 4, 5, 6, 7, 8, 9) carbon atoms.

[0075] In some embodiments of the present invention, the R N2 represents a straight-chain alkoxy group having 1 to 9 carbon atoms.

[0076] In some preferred embodiments of the present invention, the compound of formula N comprises at least one (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, etc.) selected from the group consisting of the compounds of formula N-2, the compounds of formula N-3, the compounds of formula N-5, the compounds of formula N-6, the compounds of formula N-10, the compounds of formula N-11, the compounds of formula N-12, the compounds of formula N-25, the compounds of formula N-29.

[0077] In some preferred embodiments of the present invention, the compound of formula N comprises at least one (e.g., 1, 2, 3, etc.) compound of formula N-12.

[0078] In some preferred embodiments of the present invention, the compound of formula N comprises at least one (e.g., 1, 2, 3, 4, 5, etc.) selected from the group consisting of the compounds of formula N-3 and the compounds of formula N-6.

[0079] In some embodiments of the present invention, the mass percentage content of the compound of formula N in the liquid crystal composition is 1% - 75%, for example, it can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 35%, 38%, 38.5%, 40%, 45%, 47.5%, 48.5%, 49%, 49.5%, 50%, 51%, 51.5%, 55%, 58%, 60%, 65%, 68%, 70% or 73%, etc., and further preferably 20% - 65%.

[0080] In some embodiments of the present invention, the mass percentage content of at least one (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, etc.) compound of formula N selected from the group consisting of compounds of formula N-2, compounds of formula N-3, compounds of formula N-5, compounds of formula N-6, compounds of formula N-10, compounds of formula N-11, compounds of formula N-12, compounds of formula N-25, and compounds of formula N-29 is 1% - 73%, for example, it can be 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 35%, 38%, 38.5%, 40%, 45%, 47.5%, 48.5%, 49%, 49.5%, 50%, 51%, 51.5%, 55%, 58%, 60%, 65%, 70%, or 73%, etc., and further preferably 20% - 65%.

[0081] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of formula M:

[0082]

[0083] Wherein, R M1 and R M2 each independently represents a straight-chain or branched-chain alkyl group containing 1 - 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group containing 1 - 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO- respectively;

[0084] Ring Ring and Ring each independently represents The one or at least two -CH2- in can be replaced by -O-, and one or at most two single bonds in the ring can be replaced by double bonds; at most one -H in the can be replaced by a halogen;

[0085] Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2-, or -(CH2)4-;

[0086] n M1represents 0, 1, 2 or 3, where when n M1 = 2 or 3, the rings are the same or different, and Z M2 are the same or different.

[0087] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of the following compounds:

[0088]

[0089]

[0090]

[0091]

[0092]

[0093] and

[0094]

[0095] wherein, R M1 and R M2 each independently represent a straight-chain or branched-chain alkyl group containing 1-10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, and one or more than two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group containing 1-10 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-.

[0096] In some embodiments of the present invention, the R M1 and R M2 each independently represent a straight-chain alkyl group containing 1-10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, a straight-chain alkoxy group containing 1-9 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9) carbon atoms or a straight-chain alkenyl group containing 2-9 (e.g., 2, 3, 4, 5, 6, 7, 8, 9) carbon atoms, preferably a straight-chain alkyl group containing 1-10 carbon atoms and a straight-chain alkenyl group containing 2-9 carbon atoms.

[0097] In some embodiments of the present invention, the compound of formula M comprises at least one (e.g., 1, 2, 3, 4, 5, 6, etc.) selected from the group consisting of the compound of formula M-1, the compound of formula M-14, the compound of formula M-22, the compound of formula M-29, the compound of formula M-30, the compound of formula M-37, and the compound of formula M-45.

[0098] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of the following compounds:

[0099]

[0100] and

[0101]

[0102] wherein,

[0103] R M11 and R M21 each independently represents a straight-chain alkenyl group containing 2 - 8 (e.g., 2, 3, 4, 5, 6, 7, 8) carbon atoms;

[0104] R M1 and R M2 each independently represents a straight-chain alkyl group containing 1 - 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, or a straight-chain alkoxy group containing 1 - 9 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9) carbon atoms.

[0105] The alkenyl group in the present invention is preferably a group represented by any one of formula (V1) to formula (V9), and particularly preferably formula (V1), formula (V2), formula (V8), or (V9). The groups represented by formula (V1) to formula (V9) are shown as follows:

[0106] wherein, * represents a carbon atom in the ring structure to which it is bonded.

[0107] In some embodiments of the present invention, the mass percentage content of the compound of formula M in the liquid crystal composition is 1% - 80%, for example, it can be 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 25%, 28%, 30%, 35%, 38%, 38.5%, 39%, 40%, 41.5%, 42%, 43.5%, 45%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, or 75%, etc., and more preferably 15% - 50%.

[0108] In some embodiments of the present invention, the mass percentage content of at least one (e.g., 1, 2, 3, 4, 5, 6, etc.) compound of formula M selected from the group consisting of compounds of formula M-1, compounds of formula M-14, compounds of formula M-22, compounds of formula M-29, compounds of formula M-30, compounds of formula M-37, and compounds of formula M-45 is 1% - 75%, for example, it can be 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 25%, 28%, 30%, 35%, 38%, 38.5%, 39%, 40%, 41.5%, 42%, 43.5%, 45%, 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, or 75%, etc., and more preferably 15% - 50%.

[0109] In addition to the above compounds, the liquid crystal composition of the present invention may also contain any one or a combination of at least two of ordinary nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, polymerizable monomers, and additives.

[0110] In a preferred technical solution, the liquid crystal composition further includes at least one additive.

[0111] In a preferred technical solution, the additive includes any one or a combination of at least two of a dopant, an antioxidant, an ultraviolet absorber, an infrared absorber, and other light stabilizers.

[0112] It should be noted that the other light stabilizers refer to light stabilizers different from the compounds of formula II-1, the compounds of formula II-2, the compounds of formula II-3, and the compounds of formula II-4.

[0113] The following shows the possible dopants preferably added to the liquid crystal composition of the present invention:

[0114]

[0115]

[0116] and

[0117]

[0118] wherein, + represents a chiral site.

[0119] In some embodiments of the present invention, the mass percentage content of the dopant in the liquid crystal composition is 0% - 5%; preferably, the mass percentage content of the dopant in the liquid crystal composition is 0.01% - 1%.

[0120] In addition, additives such as antioxidants and other light stabilizers used in the liquid crystal composition of the present invention are preferably the following substances:

[0121]

[0122]

[0123]

[0124] Among them, x represents a positive integer from 1 to 12.

[0125] Exemplarily, other light stabilizers are selected from the light stabilizers shown below:

[0126]

[0127] In some embodiments of the present invention, the mass percentage content of other light stabilizers in the liquid crystal composition is 0% - 5%; preferably, the mass percentage content of other light stabilizers in the liquid crystal composition is 0.01% - 1%, and more preferably 0.01% - 0.1%.

[0128] In a second aspect, the present invention provides a liquid crystal display device, which comprises the liquid crystal composition as described in the first aspect.

[0129] In a preferred technical solution, the liquid crystal display device is any one of VA display mode, PSVA display mode, IPS display mode, and NFFS display mode.

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

[0131] In the liquid crystal composition provided by the present invention, by compounding a stabilizer with a specific structure with a compound of formula I having a dibenzo structure, on the basis of maintaining an appropriate clearing point, optical anisotropy, and dielectric anisotropy, it has a relatively high elastic constant K 11 and K 33 , a relatively small rotational viscosity γ1, a relatively short response time RT, a relatively fast response speed, a relatively high transmittance Tr, a relatively high contrast ratio CR, good low-temperature storage stability, a wider nematic phase temperature range, and reduces image sticking residue or accelerates the dissipation of image residue, has a relatively high voltage holding ratio VHR, helps to improve the overall use effect of liquid crystal materials, and is applicable to fast-response VA, PSVA, IPS, NFFS and other display modes. Detailed Embodiments

[0132] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

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

[0134] Table 1

[0135]

[0136] Taking the compound with the following structural formula as an example:

[0137] If this structure is represented by the codes listed in Table 1, it can be expressed as: nCLWO2; where C represents 1,4-cyclohexylene, L represents 1,4-cyclohexenylene, W represents 2,3-difluoro-1,4-phenylene, n represents the number of carbon atoms of the alkyl group at the left end. For example, when n is "3", it means that the alkyl group is n-propyl, and OC2H5 represents ethoxy.

[0138] The abbreviated codes for the test items in the following examples and comparative examples are as follows:

[0139] Cp Clearing point (nematic-isotropic phase transition temperature, °C)

[0140] Δn Optical anisotropy (589 nm, 25 °C)

[0141] Δε Dielectric anisotropy (1 kHz, 25 °C)

[0142] K 11 Splay elastic constant (25 °C)

[0143] K 33 Bend elastic constant (25 °C)

[0144] γ1 Rotational viscosity (mPa·s, 25 °C)

[0145] Tr Transmittance (%)

[0146] CR Contrast ratio (bright state transmittance / dark state transmittance, 25 °C)

[0147] RT Response time (ms)

[0148] LTS(-40 °C) Low temperature storage time (-40 °C, h)

[0149] IS Dissipation time of image retention (min)

[0150] Among them, Cp: measured by MP70 melting point instrument;

[0151] Δn: Δn = n e -n o , measured using an Abbe refractometer under a sodium lamp (589 nm) light source at 25 °C;

[0152] Δε: Δε = ε ∥ -ε ⊥ , where ε ∥ is the dielectric constant parallel to the molecular axis, and ε ⊥ is the dielectric constant perpendicular to the molecular axis. Test conditions: VA type test cell at 25 °C, 1 kHz, and cell thickness of 6 μm;

[0153] K 11 and K 33 : Calculated by measuring the C-V curve of the liquid crystal using an LCR meter and a VA test cell. Test conditions: VA type test cell with a thickness of 6 μm, V = 0.1 - 20 V;

[0154] γ1: Measured using an LCM-2 type liquid crystal physical property evaluation system. Test conditions: 25 °C, 160 - 240 V, and cell thickness of 20 μm;

[0155] Tr: Measure the V-T curve of the dimming device using a DMS 505 optoelectronic comprehensive tester, and take the maximum value of the transmittance on the V-T curve as the transmittance of the liquid crystal. The test cell is a negative FFS cell with a thickness of 3 μm;

[0156] RT: Measured using a DMS 505 tester at 25 °C. Test conditions: Negative FFS test cell at 25 °C, V90 drive, and cell thickness of 3 μm;

[0157] CR: Measure the transmittance of the liquid crystal cell at 255 gray-scale voltage and 0 gray-scale voltage respectively using a DMS 505 tester, i.e., T r255 and T r0 , and obtained from T r255 / T r0 . Test conditions: Negative FFS type test cell at 25 °C and cell thickness of 3 μm;

[0158] LTS(-40 °C): Place the nematic liquid crystal medium in a glass bottle, store it at a constant temperature of -40 °C, and record the time when crystals are observed to precipitate;

[0159] IS decay time: Use a DMS 505 optoelectronic comprehensive tester to apply a supersaturated voltage (13 V) to an FFS cell for 2 h, then apply an L 64 gray-scale voltage. At this time, start reading and recording the brightness value at regular intervals, and obtain the time-brightness curve L-t1. Apply a low voltage (0.1 V) to another FFS cell for 2 h, and then apply an L64 Gray-scale voltage, and then start to read and record the luminance value every certain time interval to obtain the time-luminance curve L-t2. Then, the difference between the two curves L-t1 and L-t2 is taken to obtain the relative afterimage dissipation curve △L-t. When △L is zero, it is regarded as the complete disappearance of the afterimage, and the time t at this time is recorded as the IS dissipation time, where the cell thickness of the FFS cell is 3 μm.

[0160] The compounds used in the following examples and comparative examples can all be synthesized by known methods or obtained through commercial channels. These synthesis techniques are conventional, and each of the obtained liquid crystal compositions meets the standards of electronic compounds after testing.

[0161] Prepare the liquid crystal composition according to the ratio of each liquid crystal composition in the following examples and comparative examples. The preparation of the liquid crystal composition is carried out according to the conventional methods in the art, such as by heating, ultrasonic waves, suspension, etc. to mix in accordance with the specified ratio.

[0162] Comparative Example 1

[0163] A liquid crystal composition contains the components with the mass percentage content shown in the following table, and its performance test results are listed in the following table:

[0164]

[0165]

[0166] Comparative Example 2

[0167] A liquid crystal composition contains the components with the mass percentage content shown in the following table, and its performance test results are listed in the following table:

[0168]

[0169] Comparative Example 3

[0170] A liquid crystal composition contains the components with the mass percentage content shown in the following table, and its performance test results are listed in the following table:

[0171]

[0172]

[0173] Among them, the dosage of the stabilizer is calculated based on the dosage of other liquid crystal components being 100%. Taking Comparative Example 3 as an example, the total amount of other liquid crystal components is 100%, and the addition amount of the stabilizer is 0.003%. The following examples / comparative examples involving the stabilizer have the same expression and will not be repeated.

[0174] Example 1

[0175] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0176]

[0177]

[0178] Example 2

[0179] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0180]

[0181] Example 3

[0182] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0183]

[0184]

[0185] Example 4

[0186] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0187]

[0188]

[0189] Example 5

[0190] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0191]

[0192] Example 6

[0193] A liquid crystal composition, comprising components with mass percentages as shown in the following table, and listing the performance test results in the following table:

[0194]

[0195]

[0196] Example 7

[0197] A liquid crystal composition comprising components in the mass percentages shown in the following table and listing the performance test results in the following table:

[0198]

[0199]

[0200] Example 8

[0201] A liquid crystal composition comprising components in the mass percentages shown in the following table and listing the performance test results in the following table:

[0202]

[0203] Example 9

[0204] A liquid crystal composition comprising components in the mass percentages shown in the following table and listing the performance test results in the following table:

[0205]

[0206]

[0207] Comparing Examples 1-9 of the present invention with Comparative Examples 1-3, it can be seen that in Comparative Example 1, the compound of formula I is not included, its elastic constant K is small, the dielectric anisotropy is small, the response speed is slow, and the contrast ratio is not high; in Comparative Example 2, the compound of formula I is included, but a stabilizer with a specific structure is not contained, the image disappearance rate is slow, and its image retention is more serious than that of Comparative Example 1; in Comparative Example 3, the end group of the dibenzo compound is different from R2 in formula I defined in the present invention, resulting in a small elastic constant K, a small contrast ratio, and poor low-temperature storage performance. In Examples 1-9, through the design and compounding of the compound of formula I and a specific stabilizer, the K value, transmittance, and contrast ratio are improved, the dielectric anisotropy is increased, the response speed is improved, the low-temperature storage is improved, and the ion dissipation rate in the device is further increased, the image retention is reduced, and the problem of poor afterimage caused by using a large dielectric compound of formula I is improved.

[0208] In summary, through the compounding of liquid crystal components with a specific structure, the present invention enables the liquid crystal composition to have a larger elastic constant K value while maintaining an appropriate clearing point, optical anisotropy, and absolute value of dielectric anisotropy. K 11 is 14.2 - 15.9, K 33It is 15.2 - 17.2, with a lower rotational viscosity, γ1 is 73 - 76 mPa·s, a short response time, RT is 21.24 - 23.35 ms, a faster response speed, a higher transmittance, Tr is 14.3% - 15.2%, a contrast ratio CR is 1298 - 1451, it can be stably stored at -40°C for more than 144 h, has better low-temperature storage stability, has a wider nematic phase temperature range and better contrast, and has a short IS decay time, reducing image viscous residue or accelerating the dissipation of image residue, thus improving the overall usage effect of the liquid crystal material.

[0209] The applicant declares that the present invention uses the above embodiments to illustrate the liquid crystal composition of the present invention and the liquid crystal display device containing the same, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A liquid crystal composition, characterized in that, The liquid crystal composition comprises: at least one compound of formula I: and at least one stabilizer selected from the group consisting of the following compounds: wherein, R1 represents -H, halogen, a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, the straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, one or at least two non-adjacent -CH2- in the above can be independently replaced by -CH=CH-, -C≡C-, -O-, -S-, -CO-, -CO-O- or -O-CO- respectively, and one or at least two -H in the foregoing groups can be independently replaced by -F or -Cl; R2 represents a haloalkyl group having 1 to 3 carbon atoms, wherein one or at most two single bonds in the ring may be replaced by double bonds; Ring and the ring each independently represents the one or at least two -CH2- in the said can be replaced by -O-, and one or at most two single bonds in the ring can be replaced by double bonds; the one or at least two -H in the said can be replaced by -F, -Cl, -CN, -CH3 or -OCH3, and one or at least two -CH= in the ring can be replaced by -N=; Z1 and Z2 each independently represent a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH═CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; Z3 represents a single bond, -O(CH2) a - or -S(CH2) a -; a represents an integer from 0 to 5; L1 and L2 each independently represent -H, a halogen, a halogenated or unhalogenated alkyl group having 1 to 3 carbon atoms, a halogenated or unhalogenated alkoxy group having 1 to 3 carbon atoms; G represents -O-, -S-, -CO-, -CF2-, -NH- or -NF-; X represents -H, -OH, -O*, a straight-chain or branched alkyl group having 1 to 5 carbon atoms; one or at least two non-adjacent -CH2- in the straight-chain or branched alkyl group having 1 to 5 carbon atoms may be independently replaced by -O- or -CO- respectively; -O* represents an oxygen radical; n1 represents 0 or 1; n2 represents 0, 1 or 2; when n2 = 2, the ring are the same or different, Z2 are the same or different; n represents an integer from 1 to 20.

2. The liquid crystal composition according to claim 1, characterized in that, The compound of formula I is selected from the group consisting of the following compounds: and wherein, R1, R2 and Z3 have the same defined ranges as in formula I; Y1 and Y2 each independently represent -O- or -CH2-.

3. The liquid crystal composition according to claim 1, characterized in that, The mass percentage content of the compound of formula I in the liquid crystal composition is 1% - 30%.

4. The liquid crystal composition according to claim 1, wherein The X represents -H, -OH, -O*, a straight-chain or branched alkyl group having 1 to 5 carbon atoms, a straight-chain or branched alkoxy group having 1 to 5 carbon atoms, a straight-chain or branched acyl group having 1 to 5 carbon atoms.

5. The liquid crystal composition according to claim 1, characterized in that, The mass percentage content of the stabilizer in the liquid crystal composition is 0.001% - 0.1%.

6. The liquid crystal composition according to claim 1, characterized in that, The liquid crystal composition further comprises at least one compound of formula N: Among them, R N1 and R N2 each independently represents a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO- respectively; Ring and the ring each independently represents wherein one or at least two of the -CH2- therein can be replaced by -O-, and one or at most two single bonds in the ring can be replaced by double bonds, wherein one or at least two of the -H therein can be independently replaced by -F, -Cl or -CN respectively, and one or at least two of the -CH= in the ring can be replaced by -N=; L N1 and L N2 each independently represents -H, a halogen, a straight-chain or branched alkyl group having 1 to 3 carbon atoms, or a straight-chain or branched alkoxy group having 1 to 3 carbon atoms; Z N1 and Z N2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH═CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; n N1 represents 0, 1, 2, or 3, where n N2 represents 0 or 1, and 0 ≤ n N1 + n N2 ≤ 3; When n N1 represents 2 or 3, the rings are the same or different, and Z N1 are the same or different.

7. The liquid crystal composition according to claim 6, characterized in that, The compound of formula N is selected from the group consisting of the following compounds: and wherein, R N1 and R N2 have the same defined ranges as in formula N.

8. The liquid crystal composition according to claim 1, wherein The liquid crystal composition further comprises at least one compound of formula M: Among them, R M1 and R M2 each independently represents a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO- respectively; Ring Ring and the ring each independently represents the one or at least two -CH2- in the above can be replaced by -O-, and one or at most two single bonds in the ring can be replaced by double bonds; the at most one -H in the above can be replaced by a halogen; Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2- or -(CH2)4-; n M1 represents 0, 1, 2 or 3, where when n M1 = 2 or 3, the rings are the same or different, and Z M2 are the same or different.

9. The liquid crystal composition according to claim 8, wherein, The compound of formula M is selected from the group consisting of the following compounds: and Wherein, R M1 and R M2 each independently represents a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms, and one or two or more non-adjacent -CH2- in the straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO- respectively.

10. A liquid crystal display device, which comprises the liquid crystal composition according to any one of claims 1 - 9.

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