Liquid crystal composition and liquid crystal display device containing the same

Abstract

The present invention provides a liquid crystal composition and a liquid crystal display device comprising the same, wherein the liquid crystal composition comprises at least one compound of formula I and at least one compound of formula II. Through the selection and compounding of components, the liquid crystal composition has a higher clearing point, appropriate optical anisotropy, appropriate dielectric anisotropy, lower rotational viscosity, a larger elastic constant K value, a shorter response time and a faster response speed, a smaller dark state transmittance, a larger bright state transmittance and a higher contrast, so that the liquid crystal display device comprising the same has a better contrast, a higher transmittance, a faster response speed, a shorter refresh time and a wider operating temperature range, which helps to significantly improve the display effect of the liquid crystal display and is suitable for display modes such as VA, PSVA, IPS, and NFFS.

Description

Technical Field

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

[0002] Liquid Crystal Display (LCD) has the characteristics of small size, light weight, low power consumption and excellent display quality. It has been developed rapidly in recent years, especially in portable electronic information products. As the screen size for portable computers, office applications and video applications continues to increase, LCD can be used for large-screen display and eventually replace cathode ray tube (CRT) display.

[0003] Compared with traditional display devices and display materials, liquid crystal display materials have obvious advantages: low driving voltage, low power consumption, high reliability, large amount of displayed information, color display, no flicker, no harm 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 display and imaging field, 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] Liquid crystal materials are mixtures of organic rod-shaped small molecular compounds that have both the fluidity of liquid and the anisotropy of crystal at a certain temperature. Liquid crystal display devices work by utilizing the optical anisotropy and dielectric anisotropy of liquid crystal materials themselves, and have been widely used. Liquid crystal display elements are divided into the following types based on the operation mode of liquid crystal molecules: PC (phase change), TN (twist nematic), STN (super twisted nematic), DS (dynamic scattering), FLC (ferroelectric liquid crystal, FLC), GH (guest-host), ECB (electrically controlled birefringence), OCB (optically compensated bend), IPS (in-plane switching), VA (vertical alignment), FFS (fringe field switching), FPA (field-induced photo-reactive alignment), etc. In addition, new display modes include, for example, UV2A (Ultra Violet Vertical Alignment), PSVA (Polymer Stabilized Vertical Alignment), NFFS (Negativityfringe field switching), etc. According to the driving method of the element, liquid crystal display elements can be divided into PM (passive matrix) type and AM (active matrix) type. PM is divided into static and multiplex types. AM is divided into TFT (thin film transistor), MIM (metal insulator metal), etc. TFT types include amorphous silicon and polycrystalline silicon. The latter is divided into high temperature type and low temperature type according to the manufacturing process. According to the type of light source, liquid crystal display elements can be divided into reflective type using natural light, transmissive type using backlight, and semi-transmissive type using both natural light and backlight.

[0005] The liquid crystal display device contains a nematic liquid crystal composition having appropriate characteristics. By improving the characteristics of the liquid crystal composition, an AM element having good characteristics can be obtained. The correlation between the characteristics of the liquid crystal composition and the characteristics of the AM element is summarized in Table 1.

[0006] Table 1 Characteristics of liquid crystal composition and characteristics of AM element

[0007] serial number Characteristics of Liquid Crystal Compositions Characteristics of AM components 1 Nematic phase has a wide temperature range Wide temperature range 2 Low viscosity Short response time 3 Optical anisotropy is appropriate High contrast 4 The absolute value of positive or negative dielectric anisotropy is large Low threshold voltage, low power consumption, high contrast 5 Larger specific resistance High voltage holding rate and contrast ratio 6 UV and heat stable Long life 7 Large elastic constant High contrast and short response time

[0008] In liquid crystal display devices, the contrast (CR) has a critical impact on visual effects. Generally speaking, the greater the contrast, the clearer and more eye-catching the image, and the brighter the color; if the contrast is small, the entire picture will be blurred. High contrast is of great help to the clarity, detail, and grayscale performance of the image; high-contrast products have outstanding advantages in black and white contrast, clarity, and integrity. At the same time, contrast also has a great impact on the display effect of dynamic videos. Since the light and dark conversion in dynamic images is relatively fast, the higher the contrast, the easier it is for the human eye to distinguish such a conversion process.

[0009] The relationship between contrast (CR) and brightness (L) is as follows: CR = L 255 / L0×100%; where L 255 L0 is the brightness of the on state, and L0 is the brightness of the off state. It can be seen that the change of L0 should significantly affect CR. In the off state, L0 has nothing to do with the dielectric properties of the liquid crystal molecules, but is related to the LC Scattering (light scattering) of the liquid crystal material itself; the smaller the LC Scattering, the smaller the L0, and the CR will be significantly improved.

[0010] Where, d represents the spacing of the liquid crystal cell, n e is the extraordinary refractive index, n o represents the ordinary refractive index, K ave represents the average elastic constant. From this relationship, we can see that LCScattering and K ave Inversely proportional to the K ave In this case, the light leakage of the liquid crystal material can be reduced, thereby significantly reducing the L0 brightness and improving the contrast.

[0011] In addition, the response speed of liquid crystal materials is also affected by the elastic constant K value. Generally speaking, the larger the K value, the faster the response rate of the liquid crystal will be, thereby increasing the refresh rate of the display, preventing display problems such as afterimages and smears, and improving the display effect. Therefore, increasing the elastic constant of liquid crystal materials and improving the contrast and response speed of liquid crystal materials are issues that need to be urgently addressed in this field.

[0012] The modulation of the liquid crystal composition formula should adjust many performance parameters of the liquid crystal composition at the same time. It is impossible to adjust a certain performance parameter without affecting the value of another parameter. Sometimes, adding a certain monomer liquid crystal to adjust a certain performance parameter of the liquid crystal composition may be beneficial to one or more other performance parameters, but may also be detrimental to the improvement of other performance parameters. Therefore, how to obtain a liquid crystal composition that can fully or partially solve the above problems is still a problem to be solved in the art. Summary of the invention

[0013] In view of the deficiencies in 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, wherein the liquid crystal composition has a higher clearing point, appropriate optical anisotropy, appropriate dielectric anisotropy, a larger elastic constant, a shorter response time, a smaller dark state transmittance, a larger bright state transmittance and a higher contrast, and can significantly improve the display effect of the liquid crystal display.

[0014] To achieve this object, the present invention adopts the following technical solutions:

[0015] In a first aspect, the present invention provides a liquid crystal composition with negative dielectric anisotropy, the liquid crystal composition comprising:

[0016] At least one compound of formula I:

[0017] as well as

[0018] At least one compound of formula II:

[0019]

[0020] wherein R0 represents a straight or branched chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the aforementioned groups can be independently replaced by -F or -Cl;

[0021] R Xrepresents a haloalkyl group containing 1-5 (e.g., 1, 2, 3, 4, or 5) carbon atoms, a haloalkoxy group containing 1-4 (e.g., 1, 2, 3, or 4) carbon atoms, or 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, wherein one or at least two non-adjacent -CH2- in the straight-chain or branched-chain alkyl group containing 1-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-;

[0022] ring and ring Each independently expresses or one or at least two rings with single bonds replaced by double bonds And at most one ring or ring express

[0023] R1 and R2 each independently represent a straight or branched chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0024] ring and ring Each independently expresses It is stated One or at least two -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by double bonds, wherein In one or at least two rings, -CH= may be replaced by -N=, and in the aforementioned groups, one or at least two -H may be replaced by -F, -Cl or -CN;

[0025] n1 represents 1 or 2, n2 represents 0 or 1, and when n1 represents 2, the ring Same or different.

[0026] The liquid crystal composition provided by the present invention is a liquid crystal composition with negative dielectric anisotropy. The compound of formula I containing a cyclohexene structural unit and the compound of formula II cooperate with each other, so that the liquid crystal composition has a higher clearing point, appropriate optical anisotropy and appropriate absolute value of dielectric anisotropy, and at the same time has a larger elastic constant K value, a shorter response time, a smaller dark state transmittance, a larger bright state transmittance and a higher contrast, which helps to significantly improve the display effect of a liquid crystal display and is suitable for display modes such as VA, PSVA, IPS, and NFFS.

[0027] In the present invention, “may be independently replaced by…” means that it may (can) be replaced or not be replaced, that is, replacement or not being replaced falls within the protection scope of the present invention; the same applies to “may be independently replaced by…”; moreover, the positions of “replacement” and “replacement” are arbitrary.

[0028] In the present invention, the short straight lines on one or both sides of a group represent access bonds, not methyl groups; for example The short straight line on the left, Short straight lines on both sides.

[0029] In the present invention, the halogen includes fluorine, chlorine, bromine or iodine, etc.; when the same description is mentioned below, they have the same meaning.

[0030] In the present invention, the term "halogenated" or "substituted by halogen" means that at least one hydrogen in the group is replaced by halogen (fluorine, chlorine, bromine or iodine).

[0031] In a preferred technical solution, the ring and ring Each independently expresses And at most one ring or ring express

[0032] In a preferred technical solution, the compound of formula I is selected from the group consisting of the following compounds:

[0033]

[0034] as well as

[0035]

[0036] Among them, R X ' represents a straight or branched alkyl group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms.

[0037] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time, the compound of formula I contains at least one compound selected from the group consisting of compounds of formula I-1 and compounds of formula I-2.

[0038] In a preferred technical embodiment, R0 represents a straight-chain alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms or a straight-chain alkenyl group containing 2-8 (e.g., 2, 3, 4, 5, 6, 7 or 8) carbon atoms.

[0039] In a preferred technical solution, the compound of formula II is selected from the group consisting of the following compounds:

[0040]

[0041]

[0042] as well as

[0043]

[0044] In a preferred technical scheme, the compound of formula II contains at least one compound selected from the group consisting of compounds of formula II-1, compounds of formula II-2, compounds of formula II-4, compounds of formula II-5, compounds of formula II-8, compounds of formula II-10, compounds of formula II-11, compounds of formula II-14, compounds of formula II-15, and compounds of formula II-19.

[0045] In a preferred technical embodiment, R1 and R2 each independently represent a straight-chain alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, a straight-chain alkoxy group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, or a straight-chain alkenyl group containing 2-8 (e.g., 2, 3, 4, 5, 6, 7 or 8) carbon atoms.

[0046] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time. In the compounds of the group consisting of compounds of formula II-4, compounds of formula II-5 and compounds of formula II-6, R1 and R2 each independently represent a straight-chain alkoxy group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms.

[0047] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time, the compound of formula II contains at least one compound selected from the group consisting of compounds of formula II-4, compounds of formula II-5, compounds of formula II-6, compounds of formula II-8, compounds of formula II-9 and compounds of formula II-14.

[0048] In a preferred technical solution, the content of the compound of formula I is adjusted so that the liquid crystal composition containing it has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0049] In a preferred technical solution, the mass percentage of the compound of formula I in the liquid crystal composition is 1%-20%, for example, it can be 2%, 3%, 5%, 7%, 9%, 10%, 11%, 13%, 15%, 17% or 19%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0050] In a preferred technical solution, the content of the compound of formula II is adjusted so that the liquid crystal composition has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0051] In a preferred technical solution, the mass percentage of the compound of formula II in the liquid crystal composition is 5%-60%, for example, it can be 6%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55%, 56%, 57% or 58%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0052] In a preferred technical scheme, the compound of formula II contains at least one compound selected from the group consisting of compounds of formula II-2, compounds of formula II-3, compounds of formula II-15, compounds of formula II-16, compounds of formula II-17, and compounds of formula II-18; preferably, the mass percentage of the compound selected from the group consisting of said compounds is 0.1%-30%, for example, it can be 0.5%, 1%, 3%, 5%, 6%, 8%, 10%, 12%, 15%, 16%, 18%, 20%, 22%, 24%, 25%, 26%, 27%, 28%, 29% or 30%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0053] In a preferred technical solution, the liquid crystal composition further comprises at least one compound of formula N:

[0054]

[0055] Among them, R N1 and R N2 Each independently represents a straight or branched chain alkyl group containing 1 to 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 or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0056] ring and ring Each independently expresses Said One or at least two -CH2- in the In one or at least two rings, -CH= may be replaced by -N=, and in the aforementioned groups, one or at least two -H may be replaced by -F, -Cl or -CN;

[0057] 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-;

[0058] L N1 and L N2 Each independently represents -H, halogen, unsubstituted or halogenated straight-chain alkyl containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0059] n N1 Represents 0, 1, 2, or 3, n N2 Represents 0 or 1, and 0≤n N1 +n N2 ≤3, where n N1 When it means 2 or 3, the ring Same or different, Z N1 the same or different; and

[0060] When 0<n N1 +n N2 When ≤3, Z N1 and Z N2 At least one of is not a single bond.

[0061] In a preferred technical solution, the compound of formula N is selected from the group consisting of the following compounds:

[0062]

[0063]

[0064] as well as

[0065]

[0066] In a preferred technical solution, the R N1 and R N2 Each independently represents a straight-chain alkyl group containing 1-8 (e.g. 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, a straight-chain alkoxy group containing 1-8 (e.g. 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, or a straight-chain alkenyl group containing 2-8 (e.g. 2, 3, 4, 5, 6, 7 or 8) carbon atoms.

[0067] In a preferred technical solution, the content of the compound of formula N is adjusted so that the liquid crystal composition has a higher clearing point, a proper optical anisotropy, a proper absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0068] In a preferred technical solution, the mass percentage of the compound of formula N in the liquid crystal composition is 0.1%-60%, for example, it can be 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50%, 52%, 55% or 58%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0069] In a preferred technical solution, the liquid crystal composition further comprises at least one compound of formula M:

[0070]

[0071] Among them, R M1 and R M2 Each independently represents a straight or branched chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0072] ring ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- in the In one or at least two rings, -CH= may be replaced by -N=, and at most one -H may be replaced by halogen;

[0073] Z M1 and Z M2each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -C≡C-, -CH=CH-, -CH2CH2- or -(CH2)4-; and

[0074] n M represents 0, 1, or 2, where n M When it indicates 2, the ring Same or different, Z M2 Same or different.

[0075] In a preferred technical solution, the compound of formula M is selected from the group consisting of the following compounds:

[0076]

[0077]

[0078]

[0079] as well as

[0080]

[0081] In a preferred technical solution, the compound of formula M is selected from any one or a combination of at least two of the compounds of formula M-1, M-2, M-4, M-10, M-12, M-23 and M-25.

[0082] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time, the liquid crystal composition comprises a compound of the group consisting of a compound of formula M-1, a compound of formula M-2 or a compound of formula M-12.

[0083] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time, the liquid crystal composition contains at least one compound of formula M-1.

[0084] In a preferred technical solution, the R M1 and R M2Each independently represents a straight-chain alkyl group containing 1-8 (e.g. 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, a straight-chain alkoxy group containing 1-8 (e.g. 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, or a straight-chain alkenyl group containing 2-8 (e.g. 2, 3, 4, 5, 6, 7 or 8) carbon atoms.

[0085] In a preferred technical solution, the content of the compound of formula M is adjusted so that the liquid crystal composition containing it has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0086] In a preferred technical solution, the mass percentage of the compound of formula M in the liquid crystal composition is 0.1%-50%, for example, it can be 0.5%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48% or 50%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0087] In a preferred technical solution, the liquid crystal composition further comprises at least one compound of formula B:

[0088]

[0089] Among them, R B1 and R B2 Each independently represents -H, halogen, a straight or branched chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, m B represents an integer from 0 to 6, for example, 0, 1, 2, 3, 4, 5 or 6; one or at least two non-adjacent -CH2- in the aforementioned groups may be independently replaced by -CH=CH-, -C≡C-, -S-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the aforementioned groups may be independently replaced by -F or -Cl;

[0090] ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by double bonds, wherein the In one or at least two rings, -CH= may be replaced by -N=, and in the aforementioned groups, one or at least two -H may be replaced by -F, -Cl, -CN, -CH3 or -OCH3;

[0091] Z B1 and Z B2 Each independently represents a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0092] Y B1 and Y B2 Each independently represents -H, halogen, unsubstituted or halogenated straight-chain alkyl containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms, or unsubstituted or halogenated straight-chain alkoxy containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0093] X B represents -O-, -S- or -CO-; and

[0094] n B1 and n B2 Each independently represents 0, 1 or 2, where n B1 When it indicates 2, the ring Same or different, Z B1 Same or different, where n B2 When it indicates 2, the ring Same or different, Z B2 Same or different.

[0095] In a preferred technical solution, the compound of formula B is selected from the group consisting of the following compounds:

[0096]

[0097]

[0098] as well as

[0099]

[0100] Among them, R B1 ' and R B2' each independently represents a straight or branched chain alkyl group containing 1-11 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11) carbon atoms.

[0101] In a preferred technical solution, in order to obtain a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger bright state transmittance, higher contrast and shorter response time, the liquid crystal composition of the present invention comprises at least one compound of formula B-1.

[0102] In a preferred technical solution, the content of the compound of formula B is preferably adjusted so that the liquid crystal composition of the present invention has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0103] In a preferred technical solution, the mass percentage of the compound of formula B in the liquid crystal composition is 0.1%-30%, for example, it can be 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25% or 28%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0104] In a preferred technical solution, the liquid crystal composition further comprises at least one compound selected from the group consisting of compounds of formula A-1 and compounds of formula A-2:

[0105]

[0106] Among them, R A1 and R A2 Each independently represents a straight or branched chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H in the aforementioned groups can be independently replaced by -F or -Cl;

[0107] ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by double bonds, wherein the In one or at least two rings, -CH= may be replaced by -N=, and in one or at least two -H groups of the aforementioned groups may be replaced by -F or -Cl;

[0108] ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by double bonds, wherein the One or at least two non-adjacent -CH2- in the In one or at least two rings, -CH= may be replaced by -N=, and in one or at least two -H groups of the aforementioned groups may be replaced by -F or -Cl;

[0109] Z A11 , Z A21 and Z A22 Each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -C≡C-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-;

[0110] L A11 , L A12 , L A13 , L A21 and L A22 Each independently represents -H, halogen, unsubstituted or halogenated straight-chain alkyl containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0111] X A1 and X A2 each independently represents halogen, haloalkyl containing 1-5 (e.g. 1, 2, 3, 4 or 5) carbon atoms, haloalkoxy containing 1-5 (e.g. 1, 2, 3, 4 or 5) carbon atoms, haloalkenyl containing 2-5 (e.g. 2, 3, 4 or 5) carbon atoms or haloalkenyloxy containing 2-5 (e.g. 2, 3, 4 or 5) carbon atoms;

[0112] n A11 and nA2 Each independently represents 0, 1, 2 or 3, wherein when n A11 When it means 2 or 3, the ring Same or different, Z A11 Same or different, where n A2 When it means 2 or 3, the ring Same or different, Z A21 the same or different; and

[0113] n A12 represents 1 or 2, where n A12 When it indicates 2, the ring Same or different.

[0114] In a preferred technical solution, the compound of formula A-1 is selected from the group consisting of the following compounds:

[0115]

[0116]

[0117]

[0118] as well as

[0119]

[0120] Among them, R A1 represents a straight-chain or branched alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, wherein one or at least two non-adjacent -CH2- groups in the straight-chain or branched alkyl group containing 1-8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H groups in the aforementioned groups may be independently replaced by -F or -Cl;

[0121] R v and R w Each independently represents -CH2- or -O-;

[0122] L A11 , L A12 , L A11 ', L A12 ', L A14 , L A15 and L A16 Each independently represents -H or -F;

[0123] L A13 and L A13 'Each independently represents -H or -CH3;

[0124] X A1 represents -F, -CF3 or -OCF3; and

[0125] v and w each independently represent 0 or 1.

[0126] In a preferred technical solution, the mass percentage of the compound of formula A-1 in the liquid crystal composition is 0.1%-50%, for example, it can be 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45% or 48%, etc.

[0127] In a preferred technical solution, the compound of formula A-2 is selected from the group consisting of the following compounds:

[0128]

[0129]

[0130]

[0131] as well as

[0132]

[0133] Among them, R A2 represents a straight or branched alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms; one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1-8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; one or at least two -H in the aforementioned group may be independently replaced by -F or -Cl;

[0134] L A21 , L A22 , L A23 , L A24 and L A25 each independently represents -H or -F; and

[0135] X A2 It represents -F, -CF3, -OCF3 or -(CH2)2-CH=CF2.

[0136] In a preferred technical solution, the mass percentage of the compound of formula A-2 in the liquid crystal composition is 0.1%-50%, for example, it can be 0.3%, 0.5%, 0.8%, 1%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45% or 48%, etc.

[0137] In addition to the above compounds, the liquid crystal composition of the present invention may also contain common nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, polymerizable monomers or additives.

[0138] In a preferred technical solution, the additive includes any one of a dopant, an antioxidant, an ultraviolet absorber, an infrared absorber or a light stabilizer, or a combination of at least two thereof.

[0139] Possible dopants which are preferably added to the liquid crystal composition of the present invention are shown below:

[0140]

[0141]

[0142] as well as

[0143]

[0144] In some embodiments of the present invention, the weight percentage of the dopant in the liquid crystal composition is 0%-5%; preferably, the weight percentage of the dopant in the liquid crystal composition is 0.01%-1%.

[0145] In addition, the antioxidant, light stabilizer, ultraviolet absorber and other additives used in the liquid crystal composition of the present invention are preferably the following:

[0146]

[0147]

[0148]

[0149] Here, n represents a positive integer from 1 to 12.

[0150] Preferably, the antioxidant is selected from the compounds shown below:

[0151]

[0152] In some embodiments of the present invention, the additive accounts for 0%-5% of the total weight of the liquid crystal composition; preferably, the additive accounts for 0.01%-1% of the total weight of the liquid crystal composition.

[0153] In a second aspect, the present invention provides a liquid crystal display device, comprising the liquid crystal composition as described in the first aspect.

[0154] Compared with the prior art, the present invention has the following beneficial effects:

[0155] In the liquid crystal composition provided by the present invention, by selecting components and compounding them with each other, the liquid crystal composition has a higher clearing point, appropriate optical anisotropy, appropriate absolute value of dielectric anisotropy, lower rotational viscosity, larger elastic constant K value, shorter response time and faster response speed, smaller dark state transmittance, larger bright state transmittance and higher contrast, so that the liquid crystal display device containing the liquid crystal composition has better contrast, higher transmittance, faster response speed, shorter refresh time and wider operating temperature range, which helps to significantly improve the display effect of the liquid crystal display and is suitable for display modes such as VA, PSVA, IPS, and NFFS. DETAILED DESCRIPTION

[0156] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0157] For ease of expression, in the following embodiments and comparative examples, the group structures of the components in the liquid crystal composition are represented by the codes listed in Table 2:

[0158] Table 2

[0159]

[0160]

[0161] Take the following compound as an example:

[0162] The structure is represented by the codes listed in Table 1: nCLWO2; wherein C represents 1,4-cyclohexylene, L represents 1,4-cyclohexenylene, W represents 2,3-difluoro-1,4-phenylene, O2 represents ethoxy, and n represents the number of carbon atoms of the left-end alkyl group. For example, if n is "3", it means that the alkyl group is n-propyl.

[0163] The abbreviations of the test items in the following embodiments and comparative examples are as follows:

[0164] Cp clearing point (nematic-isotropic phase transition temperature, °C)

[0165] Δn optical anisotropy (589nm, 20℃)

[0166] Δε Dielectric anisotropy (1kHz, 20℃)

[0167] K 11 Splay elastic constant (20℃)

[0168] K 33 Bending elastic constant (20℃)

[0169] γ1 Rotational viscosity (mPa·s, 20℃)

[0170] T off Response time (ms)

[0171] Tr(0V) Dark state transmittance (%)

[0172] Tr(Max) Bright state transmittance (%)

[0173] CR contrast, Tr(Max) / Tr(0V)

[0174] Wherein, Cp: measured by MP70 melting point instrument;

[0175] Δn: measured using an Abbe refractometer under a sodium lamp (589nm) at 20°C;

[0176] Δε:Δε=ε ∥ -ε ⊥ , where ε ∥ is the dielectric constant parallel to the molecular axis, ε ⊥ is the dielectric constant perpendicular to the molecular axis, test conditions: 20°C, 1kHz, VA type test box, box thickness 6μm;

[0177] K 11 and K 33 :The capacitance-voltage characteristic curve (CV curve) of the liquid crystal material was tested and calculated using an LCR meter and a VA-type test box. Test conditions: VA-type test box, box thickness 6 μm, V = 0.1-20 V;

[0178] γ1: obtained by testing using the LCM-2 liquid crystal property evaluation system; test conditions: 20°C, 160-260V, test box thickness 20μm;

[0179] Tr(0V): Use DMS505 photoelectric comprehensive tester to test the VT curve of the test box, and take the transmittance corresponding to 0V. The test box is IPS type, and the box thickness is 3.5μm;

[0180] Tr(Max): Use DMS 505 photoelectric comprehensive tester to test the VT curve of the test box, and take the maximum transmittance of the VT curve. The test box is IPS type and the box thickness is 3.5μm;

[0181] CR: Tr(Max) / Tr(0V);

[0182] T off : Tested using DMS 505 tester at 25℃, test conditions: 25℃, V90 drive, IPS type test box with a box thickness of 3.5μm.

[0183] The compounds used in the following examples can be synthesized by known methods or obtained through commercial channels. These synthesis techniques are conventional, and the obtained liquid crystal compositions meet the standards of electronic compounds after testing.

[0184] Liquid crystal compositions are prepared according to the proportions of the liquid crystal compositions in the following examples. The preparation of the liquid crystal compositions is carried out according to conventional methods in the art, such as mixing in a prescribed proportion by heating, ultrasonic waves, suspension, etc.

[0185] Comparative Example 1

[0186] The liquid crystal composition of Comparative Example 1 was prepared according to the compounds and their mass percentages listed in Table 3, and filled between two substrates of a liquid crystal display for performance testing.

[0187] Table 3 Formulation and performance parameter test results of liquid crystal composition

[0188]

[0189] Example 1

[0190] The liquid crystal composition of Example 1 was prepared according to the compounds and their mass percentages listed in Table 4, and filled between two substrates of a liquid crystal display for performance testing.

[0191] Table 4 Formulation and performance parameter test results of liquid crystal composition

[0192]

[0193]

[0194] Example 2

[0195] The liquid crystal composition of Example 2 was prepared according to the compounds and their mass percentages listed in Table 5, and filled between two substrates of a liquid crystal display for performance testing.

[0196] Table 5 Formulation and performance parameter test results of liquid crystal composition

[0197]

[0198] From the comparison between Examples 1-2 and Comparative Example 1, it can be seen that the liquid crystal composition comprising the compound of Formula I and the compound of Formula II of the present invention has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0199] Example 3

[0200] The liquid crystal composition of Comparative Example 1 was prepared according to the compounds and their mass percentages listed in Table 6, and filled between two substrates of a liquid crystal display for performance testing.

[0201] Table 6 Formulation and performance parameter test results of liquid crystal composition

[0202]

[0203]

[0204] Example 4

[0205] The liquid crystal composition of Example 4 was prepared according to the compounds and their mass percentages listed in Table 7, and filled between two substrates of a liquid crystal display for performance testing.

[0206] Table 7 Formulation and performance parameter test results of liquid crystal composition

[0207]

[0208] Example 5

[0209] The liquid crystal composition of Example 5 was prepared according to the compounds and their mass percentages listed in Table 8, and filled between two substrates of a liquid crystal display for performance testing.

[0210] Table 8 Formulation and performance parameter test results of liquid crystal composition

[0211]

[0212]

[0213] Comparative Example 2

[0214] The liquid crystal composition of Comparative Example 2 was prepared according to the compounds and their mass percentages listed in Table 9, and filled between two substrates of a liquid crystal display for performance testing.

[0215] Table 9 Formulation and performance parameter test results of liquid crystal composition

[0216]

[0217] Example 6

[0218] The liquid crystal composition of Example 6 was prepared according to the compounds and their mass percentages listed in Table 10, and filled between two substrates of a liquid crystal display for performance testing.

[0219] Table 10 Formulation and performance parameter test results of liquid crystal composition

[0220]

[0221] From the comparison between Example 6 and Comparative Example 2, it can be seen that the liquid crystal composition comprising the compound of Formula I and the compound of Formula II of the present invention has a higher clearing point, a suitable optical anisotropy, a suitable absolute value of dielectric anisotropy, a larger K value (K 11 , K 33 ), smaller rotational viscosity, smaller dark state transmittance, larger light state transmittance, higher contrast and shorter response time.

[0222] Example 7

[0223] The liquid crystal composition of Example 7 was prepared according to the compounds listed in Table 11 and their mass percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0224] Table 11 Formulation and performance parameter test results of liquid crystal composition

[0225]

[0226] Example 8

[0227] The liquid crystal composition of Example 8 was prepared according to the compounds listed in Table 12 and their mass percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0228] Table 12 Formulation and performance parameter test results of liquid crystal composition

[0229]

[0230]

[0231] Example 9

[0232] The liquid crystal composition of Example 9 was prepared according to the compounds listed in Table 13 and their mass percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0233] Table 13 Formulation and performance parameter test results of liquid crystal composition

[0234]

[0235] In summary, the present invention, through the design and mutual cooperation of liquid crystal components, makes the liquid crystal composition have a higher clearing point, suitable optical anisotropy, appropriate dielectric anisotropy, lower rotational viscosity (γ1≤93), and a larger elastic constant K value (K 11 and K 33 ), shorter response time (T off 19.9-22.1ms) and faster response speed, lower dark state transmittance (Tr(0V) is 0.025-0.031%) and higher bright state transmittance, higher contrast, CR reaches 510-629, which helps to significantly improve the display effect of the liquid crystal display, so that the liquid crystal display device containing it has better contrast, higher transmittance, faster response speed, shorter refresh time and wider operating temperature range, and is suitable for display modes such as VA, PSVA, IPS, and NFFS.

[0236] The applicant declares that the present invention illustrates the liquid crystal composition of the present invention and the liquid crystal display device containing the same through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and 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: At least one compound of formula II: as well as At least one compound of formula M: Wherein, R0 represents a straight chain or branched chain alkyl group containing 1 to 12 carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH- or -O-; one or at least two -H in the aforementioned group can be independently replaced by -F or -Cl; R X represents a haloalkyl group containing 1 to 5 carbon atoms or a haloalkoxy group containing 1 to 4 carbon atoms; R M1 and R M2 Each independently represents a straight or branched alkyl group containing 1 to 12 carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH- or -O-; ring and ring Each independently expresses or one or at least two rings with single bonds replaced by double bonds And at most one ring or ring express R1 and R2 each independently represent a straight or branched alkyl group containing 1 to 12 carbon atoms, wherein one or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH- or -O-; ring and ring Each independently expresses It is stated One or at least two -CH2- in the ring may be replaced by -O-, one or at least two single bonds in the ring may be replaced by double bonds, and one or at least two -H in the aforementioned group may be replaced by -F, -Cl or -CN; ring ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- can be replaced by -O-; wherein At most one -H in may be replaced by halogen; Z M1 and Z M2 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -C≡C-, -CH=CH-, -CH2CH2- or -(CH2)4-; n1 represents 1 or 2, n2 represents 0 or 1, and when n1 represents 2, the ring Same or different; n M represents 0, 1, or 2; when n M When it indicates 2, the ring Same or different, Z M2 Same or different; The mass percentage of the compound of formula I in the liquid crystal composition is 1%-20%, the mass percentage of the compound of formula II is 50%-60%, and the mass percentage of the compound of formula M is 15%-50%; The compound of formula II comprises at least one compound selected from the group consisting of compounds of formula II-2, compounds of formula II-3, compounds of formula II-15, compounds of formula II-16, and compounds of formula II-17; the mass percentage of the compounds in the group consisting of the compounds is 1%-30%; 2. The liquid crystal composition according to claim 1, characterized in that: The compound of formula I is selected from the group consisting of: as well as 3. The liquid crystal composition according to claim 1, characterized in that: The compound of formula II is selected from the group consisting of: as well as The compound of formula II contains at least one compound selected from the group consisting of compounds of formula II-2, compounds of formula II-3, compounds of formula II-15, compounds of formula II-16, and compounds of formula II-17; the mass percentage of the compounds in the group consisting of the compounds is 1%-30%.

4. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises at least one compound of formula N: Among them, R N1 and R N2 Each independently represents a straight or branched alkyl group containing 1 to 12 carbon atoms, One or at least two non-adjacent -CH2- in the straight or branched alkyl group containing 1 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; ring and ring Each independently expresses Said One or at least two -CH2- in the above-mentioned may be replaced by -O-; In one or at least two rings, -CH= may be replaced by -N=, and in the aforementioned groups, one or at least two -H may be replaced by -F, -Cl or -CN; 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-; L N1 and L N2 Each independently represents -H, halogen, unsubstituted or halogenated straight-chain alkyl containing 1 to 3 carbon atoms; n N1 Represents 0, 1, 2, or 3, n N2 Represents 0 or 1, and 0≤n N1 +n N2 ≤3; when n N1 When it means 2 or 3, the ring Same or different, Z N1 the same or different; and When 0<n N1 +n N2 When ≤3, Z N1 and Z N2 At least one of is not a single bond.

5. The liquid crystal composition according to claim 4, characterized in that: The compound of formula N is selected from the group consisting of the following compounds: as well as 6. The liquid crystal composition according to claim 4, characterized in that: The mass percentage of the compound of formula N in the liquid crystal composition is 0.1%-60%.

7. The liquid crystal composition according to claim 1, characterized in that: The compound of formula M is selected from the group consisting of the following compounds: as well as 8. The liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises at least one compound of formula B: Among them, R B1 and R B2 Each independently represents -H, halogen, a straight or branched alkyl group containing 1 to 12 carbon atoms, m B represents an integer of 0-6; one or at least two non-adjacent -CH2- in the aforementioned group may be independently replaced by -CH=CH-, -C≡C-, -S-, -O-, -CO-, -CO-O- or -O-CO-; one or at least two -H in the aforementioned group may be independently replaced by -F or -Cl; ring and ring Each independently expresses It is stated One or at least two non-adjacent -CH2- in the ring may be replaced by -O-, and one or at least two single bonds in the ring may be replaced by double bonds; wherein -CH= in one or at least two rings may be replaced by -N=; one or at least two -H in the aforementioned groups may be replaced by -F, -Cl, -CN, -CH3 or -OCH3; Z B1 and Z B2 Each independently represents a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; Y B1 and Y B2 Each independently represents -H, halogen, unsubstituted or halogenated straight-chain alkyl containing 1 to 3 carbon atoms, or unsubstituted or halogenated straight-chain alkoxy containing 1 to 3 carbon atoms; X B represents -O-, -S- or -CO-; and n B1 and n B2 Each independently represents 0, 1 or 2; when n B1 When it indicates 2, the ring Same or different, Z B1 Same or different, where n B2 When it indicates 2, the ring Same or different, Z B2 Same or different.

9. The liquid crystal composition according to claim 8, characterized in that: The compound of formula B is selected from the group consisting of the following compounds: as well as Among them, R B1 ' and R B2 ' Each independently represents a straight or branched chain alkyl group containing 1 to 11 carbon atoms.

10. The liquid crystal composition according to claim 8, characterized in that: The mass percentage of the compound of formula B in the liquid crystal composition is 0.1%-30%.

11. 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 10.

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