Cholesteric liquid crystal composition, liquid crystal display device containing cholesteric liquid crystal composition and application of cholesteric liquid crystal composition

Abstract

The invention provides a cholesteric liquid crystal composition, a liquid crystal display device containing the cholesteric liquid crystal composition and application of the cholesteric liquid crystal composition. The cholesteric liquid crystal composition comprises at least one liquid crystal composition A and at least three chiral agents, the liquid crystal composition A comprises at least one compound with a general formula I and at least one compound with a general formula II, and at least one chiral agent is R / S-2011. The cholesteric liquid crystal composition has a proper clearing point and small wavelength variation along with temperature, that is, the cholesteric liquid crystal composition has small wavelength drift, and a liquid crystal display device comprising the cholesteric liquid crystal composition can have a good display effect and a wide temperature use range. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a liquid crystal composition, in particular to a cholesteric liquid crystal composition and a liquid crystal display device comprising the liquid crystal composition. Background Art

[0002] With the development of display technology, thin, light, energy-saving and environmentally friendly display devices have become the mainstream, and bistable liquid crystal display devices have attracted much attention. Among them, cholesteric liquid crystal display devices (ChLCD) have the advantages of high brightness, high contrast, power saving, high memory, wide viewing angle, no flicker, and the ability to continuously maintain two different states of bright and dark when the electric field is removed. Therefore, they have become the focus of the development of bistable displays and are widely used in e-books, electronic tags, display panels, anti-peep screens, etc. with low energy consumption requirements.

[0003] Cholesteric liquid crystal is a liquid crystal molecule with Bragg reflection and bistable properties. It can reflect incident light with a wavelength equivalent to its pitch and the same optical rotation. It can switch to a planar state (P state) or a focal conic state (Fc state) under the drive of an electric field. The P state and the Fc state can also be maintained when the voltage is disconnected, so the bistable stability is also called memory. In a cholesteric liquid crystal display, the cholesteric liquid crystal will reflect light of a specific wavelength (the specific wavelength is generally the wavelength corresponding to the highest reflectivity in the reflection spectrum, i.e., λmax) when in the planar state, so the corresponding screen displays a bright state; the cholesteric liquid crystal will scatter light in the focal conic state and be absorbed by the backplane of the display, so the corresponding screen displays a dark state.

[0004] The cholesteric liquid crystal display device shows a specific selective reflection wavelength that depends on the chiral pitch when the cholesteric phase is perpendicular to the substrate. The reflection wavelength (λ) is determined by the product of the average refractive index (n) of the liquid crystal composition and the chiral pitch (P). Therefore, when the refractive index of the liquid crystal composition is fixed, the desired selective reflection wavelength is obtained by adjusting the concentration of the chiral compound and adjusting the chiral pitch. The half-width (Δλ) of the selectively reflected light at this time is proportional to the product of the refractive index anisotropy (Δn=ne-no) of the liquid crystal and the chiral pitch, but a certain degree of wide half-width is required to achieve a bright display, so a liquid crystal composition with a large Δn must be used. In the above case, the average refractive index of the liquid crystal composition also increases, so in order to adjust to the desired λ, it is necessary to further add a chiral agent to shorten P, but if the amount of chiral compound added is excessively increased, the liquid crystal temperature range of the host liquid crystal will deteriorate and the viscosity will increase. That is, for the design of cholesteric liquid crystal, a chiral compound is required that has a high liquid crystal twisting force that induces a chiral pitch and has little effect on the host liquid crystal, and a host liquid crystal composition that has excellent compatibility with such a compound and has a high Δn is required. Furthermore, a sufficiently large dielectric anisotropy (Δε) is required to enable a liquid crystal display element to be driven at a low voltage, and good storage properties such as no precipitation in a low temperature environment are required.

[0005] The chiral pitch length of cholesteric liquid crystal depends on the type or concentration of the chiral compound added, and can be expressed by P = 1 / (HTP·c). Here, c is the concentration of the chiral compound in the cholesteric liquid crystal composition, and HTP is the force of the chiral compound to twist the liquid crystal composition, which is called helical twisting power (HTP).

[0006] The existing cholesteric liquid crystal will change its reflection wavelength with temperature changes, that is, the so-called reflection wavelength drifts with temperature changes, resulting in obvious changes in the reflection color of the cholesteric liquid crystal display device at different temperatures, which greatly affects the display quality of the cholesteric liquid crystal display device with specific requirements for the display color, and limits the operating temperature range of such display devices. In particular, for cholesteric liquid crystal display devices with two or more layers stacked, the drift of the reflection wavelength with temperature changes will cause the superimposed color of such display devices to change, greatly affecting the accuracy of the color, resulting in a decrease in the display quality of the display device and a greatly reduced operating temperature range.

[0007] How to solve the above problems is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0008] Purpose of the invention: The purpose of the present invention is to provide a cholesteric liquid crystal composition, which has an appropriate clearing point and a smaller wavelength change with temperature, that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature use range.

[0009] Technical solution: In order to achieve the above invention objectives, the present invention provides a cholesteric liquid crystal composition, comprising at least one liquid crystal composition A, and at least three (e.g., four, five, etc.) chiral agents,

[0010] Wherein, the liquid crystal composition A comprises at least one compound of the general formula I and at least one compound of the general formula II:

[0011] as well as

[0012]

[0013] At least one chiral agent is R / S-2011:

[0014]

[0015] in,

[0016] R T1 and R T2 Each independently represents -H, a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0017] R C1 represents -H, a straight-chain alkyl group having 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a branched-chain alkyl group having 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0018] ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms, and one or more -CH= in the ring may be replaced by -N=;

[0019] Z T1 and Z C1 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0020] L T1 , L T2 , L C1 and L C2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0021] L T3 and L C3 Each independently represents -H, an alkyl group or an alkoxy group containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0022] n T1 Represents 0, 1, or 2. When n T1 =2, ring Can be the same or different, Z T1 Can be the same or different;

[0023] n C1 Represents 0, 1, 2, or 3. When n C1 =2 or 3, the ring Can be the same or different, Z C1may be the same or different; and

[0024] * indicates chiral site.

[0025] In some embodiments of the present invention, the ring and ring Each independently expresses

[0026] In some embodiments of the present invention, R T1 and R T2 Preferably, each is independently a straight-chain alkyl group containing 1-8 carbon atoms, a straight-chain alkoxy group containing 1-8 carbon atoms, or a straight-chain alkenyl group containing 2-8 carbon atoms; further preferably, each is independently a straight-chain alkyl group containing 1-5 carbon atoms, a straight-chain alkoxy group containing 1-5 carbon atoms, or a straight-chain alkenyl group containing 2-5 carbon atoms.

[0027] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0028]

[0029] as well as

[0030]

[0031] in,

[0032] Z T1 ' represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-,

[0033] or -(CH2)4-;

[0034] L T1 and L T2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3; and

[0035] L T3 It represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3.

[0036] In some embodiments of the present invention, Z T1 ' represents -CO-O-, -CH=CH- or -C≡C-.

[0037] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0038]

[0039]

[0040]

[0041] as well as

[0042]

[0043] in,

[0044] L T1 ' and L T2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0045] L T4 ', L T5 ' and L T6 'Each independently represents -F, -Cl, -CH3, or -OCH3.

[0046] In some embodiments of the present invention, in order to obtain a smaller wavelength drift, the compound of general formula I preferably contains at least one (for example, two, three, four, five, or six, etc.) compound selected from the group consisting of compounds of general formula I-1-1, compounds of general formula I-2-1, and compounds of general formula I-3-1.

[0047] In some embodiments of the present invention, in order to obtain a smaller wavelength drift, the compound of general formula I preferably contains at least one (e.g., two, three, four, five, or six, etc.) compound selected from the group consisting of compounds of general formula I-1-1-1, compounds of general formula I-1-1-2, compounds of general formula I-1-1-3, compounds of general formula I-1-1-4, compounds of general formula I-1-1-5, compounds of general formula I-2-1-1, compounds of general formula I-2-1-2, compounds of general formula I-3-3-1, compounds of general formula I-3-3-2, and compounds of general formula I-3-5:

[0048]

[0049] as well as

[0050]

[0051] in,

[0052] R T1 ' and R T2 'Each independently represents -H or a straight-chain alkyl group containing 1 to 6 carbon atoms; and

[0053] R T2 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0054] In the present invention, it is preferred to adjust the content of the compound of formula I so that the liquid crystal composition containing the compound has a smaller wavelength drift.

[0055] In some embodiments of the present invention, the weight percentage of the compound of general formula I in the liquid crystal composition A is 0.1%-70% (including any numerical value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 35%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, or the range between any two values ​​therein; preferably, the weight percentage of the compound of general formula I in the liquid crystal composition A is 30%-60%.

[0056] In some embodiments of the present invention, R C1 Preferably, it is a straight-chain alkyl group containing 1-8 carbon atoms, a straight-chain alkoxy group containing 1-8 carbon atoms, or a straight-chain alkenyl group containing 2-8 carbon atoms; more preferably, it is a straight-chain alkyl group containing 1-5 carbon atoms, a straight-chain alkoxy group containing 1-5 carbon atoms, or a straight-chain alkenyl group containing 2-5 carbon atoms.

[0057] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0058]

[0059] as well as

[0060]

[0061] in,

[0062] Z C1 ' and Z C2 Each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-;

[0063] L C1 and L C2Each independently represents -H, -F, -Cl, -CF3, or -OCF3;

[0064] L C3 represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3; and

[0065] ring express in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1 to 3 carbon atoms, and -CH= in one or more rings may be replaced by -N=.

[0066] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] in,

[0075] L C1 ' and L C2 ' each independently represents -F, -Cl, -CF3, or -OCF3; and L C4 and L C5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3. In some embodiments of the present invention, Z C1 ' represents -CO-O- or -O-CO-. In some embodiments of the present invention, Z C2 It means -CO-O- or -O-CO-.

[0076] In some embodiments of the present invention, in order to obtain a small wavelength drift, the compound of general formula II preferably contains at least one (for example, two, three, or four, etc.) compound selected from the group consisting of compounds of general formula II-1-1, compounds of general formula II-2-14, compounds of general formula II-2-15, compounds of general formula II-3-2, compounds of general formula II-3-3, compounds of general formula II-5-1, and compounds of general formula II-5-2.

[0077] In some embodiments of the present invention, in order to obtain a small wavelength drift, the compound of general formula II preferably comprises at least one (e.g., two, three, or four, etc.) compound selected from the group consisting of compounds of general formula II-1-1, compounds of general formula II-1-5-1, compounds of general formula II-1-5-2, compounds of general formula II-1-5-3, compounds of general formula II-2-14-1, compounds of general formula II-2-14-2, compounds of general formula II-2-14-3, A compound of the group consisting of a compound of the general formula II-2-15-1, a compound of the general formula II-2-15-2, a compound of the general formula II-2-15-3, a compound of the general formula II-2-15-4, a compound of the general formula II-2-15-5, a compound of the general formula II-2-15-6, a compound of the general formula II-3-2-1, a compound of the general formula II-3-3-1, a compound of the general formula II-5-1-1, and a compound of the general formula II-5-2-1:

[0078]

[0079]

[0080] as well as

[0081]

[0082] in,

[0083] R C1 ' represents -H, or a straight chain alkyl group containing 1 to 6 carbon atoms; and

[0084] R C1 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0085] In the present invention, it is preferred to adjust the content of the compound of formula II so that the liquid crystal composition containing the compound has a smaller wavelength drift.

[0086] In some embodiments of the present invention, the weight percentage of the compound of formula II in the liquid crystal composition A is 0.1%-80% (including any value or sub-range between the ranges), for example 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, 32 %, 34%, 35%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, or ranges between any two of these values; preferably, the weight percentage of the compound of formula II in the liquid crystal composition A is 20%-70%.

[0087] In some embodiments of the present invention, the chiral agent of the present invention may also include at least two (e.g., three, or four, etc.) chiral agents selected from the group consisting of R / S-811, R / S-1011, R / S-5011, and R / S-6N:

[0088]

[0089] as well as

[0090]

[0091] Wherein, * indicates chiral site.

[0092] In some embodiments of the present invention, at least one chiral agent is R / S-6N.

[0093] In some embodiments of the present invention, at least one chiral agent is R / S-1011.

[0094] In some embodiments of the present invention, the at least three chiral agents are R / S-2011, R / S-1011 and R / S-6N.

[0095] In some embodiments of the present invention, in order to obtain a smaller wavelength shift, the chiral agent is preferably an iso-rotatory chiral agent.

[0096] In some embodiments of the present invention, the weight percentage of the chiral agent in the cholesteric liquid crystal composition is 0.1%-20% (including any numerical value or sub-range between the range), for example, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or the range between any two values.

[0097] In some embodiments of the present invention, the weight percentage of R / S-2011 in the cholesteric liquid crystal composition is 0.1%-10% (including any value or sub-range between the range), for example, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two values.

[0098] In some embodiments of the present invention, the weight percentage of R / S-6N in the cholesteric liquid crystal composition is 0.1%-5% (including any value or sub-range between this range), for example, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, or a range between any two values.

[0099] In some embodiments of the present invention, the weight percentage of R / S-1011 in the cholesteric liquid crystal composition is 0.1%-5% (including any value or sub-range between this range), for example, 0.1%, 0.2%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, or a range between any two values.

[0100] In the present invention, by using a cholesteric liquid crystal composition containing at least three chiral agents, the problem of reflection wavelength drift with temperature in the prior art cholesteric liquid crystal display device is creatively solved, and the temperature operating range of the cholesteric liquid crystal display is effectively broadened.

[0101] In some embodiments of the present invention, the liquid crystal composition A of the present invention further comprises at least one compound of the general formula III:

[0102]

[0103] in,

[0104] R S1 represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0105] ring express in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms, and one or more -CH= in the ring may be replaced by -N=;

[0106] Z S1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0107] L S1 and L S2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0108] L S3 represents -H, alkyl or alkoxy containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms; and

[0109] n S1 Represents 0, 1, 2, or 3. When n S1 =2 or 3, the ring Can be the same or different, Z S1 Can be the same or different.

[0110] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0111]

[0112]

[0113] as well as

[0114]

[0115] in,

[0116] L S1 and L S2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3;

[0117] Z S2 and Z S1 'Each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; and

[0118] ring express in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1-3 (e.g., 1, 2, or 3) carbon atoms, and -CH= in one or more rings may be replaced by -N=.

[0119] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] as well as

[0126]

[0127] in,

[0128] L S1 ' and L S2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0129] L S4 and L S5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

[0130] In some embodiments of the present invention, the liquid crystal composition A of the present invention comprises at least one compound of the general formula III-1-6 and at least one compound of the general formula III-1-7.

[0131] In some embodiments of the present invention, the weight percentage of the compound of general formula III in the liquid crystal composition A is 0.1%-20% (including any numerical value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, or a range between any two values ​​therein; preferably, the weight percentage of the compound of general formula III in the liquid crystal composition A is 1%-10%.

[0132] In some embodiments of the present invention, the liquid crystal composition A of the present invention further comprises at least one compound of the general formula M:

[0133]

[0134] in,

[0135] R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0136] ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, At most one -H in may be replaced by halogen;

[0137] Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2- or -(CH2)4-; and

[0138] n M represents 0, 1, or 2, where n M =2, ring Can be the same or different, Z M2 Can be the same or different.

[0139] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of:

[0140]

[0141]

[0142]

[0143]

[0144] as well as

[0145]

[0146] Among them, R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1-12 carbon atoms or a branched-chain alkyl group containing 3-12 carbon atoms, and one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-.

[0147] In some embodiments of the present invention, the weight percentage of the compound of general formula M in the liquid crystal composition A is 0.1%-20% (including any value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, or a range between any two values.

[0148] In some embodiments of the present invention, R M1 and R M2 Preferably, each is independently a straight-chain alkyl group containing 1-8 carbon atoms, a straight-chain alkoxy group containing 1-8 carbon atoms, or a straight-chain alkenyl group containing 2-8 carbon atoms; further preferably, each is independently a straight-chain alkyl group containing 1-5 carbon atoms, a straight-chain alkoxy group containing 1-5 carbon atoms, or a straight-chain alkenyl group containing 2-5 carbon atoms.

[0149] In some embodiments of the present invention, RM1 and R M2 Either one is a straight-chain alkenyl group having 2 to 5 carbon atoms, and the other is a straight-chain alkyl group having 1 to 5 carbon atoms.

[0150] In some embodiments of the present invention, the liquid crystal composition A of the present invention further comprises at least one compound of the general formula A-1 and / or the general formula A-2:

[0151]

[0152] in,

[0153] R A1 and R A2 Each independently represents a straight-chain alkyl group containing 1 to 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, a branched-chain alkyl group containing 3 to 12 (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12) carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0154] ring ring ring and ring Each independently expresses in and One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=;

[0155] Z A11 , Z A21 and Z A22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-;

[0156] L A11 , L A12 , L A13 , LA21 and L A22 Each independently represents -H, an alkyl group containing 1 to 3 carbon atoms or a halogen;

[0157] X A1 and X A2 Each independently represents halogen, a haloalkyl or haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl or haloalkenyloxy group containing 2 to 5 carbon atoms;

[0158] n A11 Represents 0, 1, 2, or 3. When n A11 =2 or 3, the ring Can be the same or different, Z A11 Can be the same or different;

[0159] n A12 represents 1 or 2, where n A12 =2, ring may be the same or different; and

[0160] n A2 represents 0, 1, 2, or 3, where n A2 =2 or 3, the ring Can be the same or different, Z A21 Can be the same or different.

[0161] In some embodiments of the present invention, at least one compound of formula A-1 and / or formula A-2 accounts for 0.1%-60% by weight of the liquid crystal composition A (including any values ​​or sub-ranges between the ranges), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 35%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, or a range between any two of the values.

[0162] In some embodiments of the present invention, the compound of formula A-1 is selected from the group consisting of the following compounds:

[0163]

[0164]

[0165]

[0166] as well as

[0167] in,

[0168] R v and R w Each independently represents -CH2- or -O-;

[0169] L A11 , L A12 , L A11 ', L A12 ', L A14 , L A15 and L A16 Each independently represents -H or -F;

[0170] L A13 and L A13 'Each independently represents -H or -CH3;

[0171] X A1 represents -F, -CF3 or -OCF3; and

[0172] v and w each independently represent 0 or 1.

[0173] In some embodiments of the present invention, the weight percentage of the compound of general formula A-1 in the liquid crystal composition A is 0.1%-30% (including any numerical value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, or a range between any two of the numerical values.

[0174] In some embodiments of the present invention, the compound of formula A-2 is selected from the group consisting of:

[0175]

[0176]

[0177]

[0178] as well as

[0179] in,

[0180] L A21 , L A22 , L A23 , L A24 and L A25 each independently represents -H or -F; and

[0181] XA2 It represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

[0182] In some embodiments of the present invention, the weight percentage of the compound of general formula A-2 in the liquid crystal composition A is 0.1%-50% (including any numerical value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 35%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, or the range between any two values.

[0183] In some embodiments of the present invention, at least one compound of formula A-1 and / or formula A-2 accounts for 0.1%-30% (including any value or sub-range between the range) of the liquid crystal composition, for example, 0.1%, 1%, 2%, 4%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 20%, 22%, 24%, 25%, 26%, 28%, 30%, or a range between any two of the values.

[0184] In addition to the above-mentioned compounds, the liquid crystal composition of the present invention may contain a common antioxidant, an ultraviolet absorber, an infrared absorber, a photoinitiator, a polymerizable monomer, a light stabilizer, and the like.

[0185] In addition, the antioxidants, light stabilizers and other additives used in the liquid crystal composition of the present invention are preferably the following:

[0186]

[0187]

[0188]

[0189] Here, n represents a positive integer from 1 to 12.

[0190] Preferably, the antioxidant is selected from the light stabilizers shown below:

[0191]

[0192] 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.

[0193] In some embodiments of the present invention, the weight percentage of liquid crystal composition A in the cholesteric liquid crystal composition is 80%-99% (including any numerical value or sub-range between the range), for example, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or the range between any two values.

[0194] In some embodiments of the present invention, at a temperature range of 0°C to 60°C, the wavelength shift (Δλmax) of the cholesteric liquid crystal composition of the present invention is in the range of 1-10nm (including any numerical value or sub-range between the range), for example, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, or 10nm, or a range between any two of the numerical values.

[0195] In some embodiments of the present invention, the pitch P of the cholesteric liquid crystal composition of the present invention is in the range of 0.1-1 μm (including any numerical value or sub-range between the range), for example, 0.1 μm, 0.2 μm, 0.22 μm, 0.24 μm, 0.25 μm, 0.26 μm, 0.28 μm, 0.29 μm, 0.3 μm, 0.32 μm, 0.35 μm, 0.36 μm, 0.38 μm, 0.39 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm, or a range between any two values ​​therein.

[0196] The present invention also provides a liquid crystal display device comprising the cholesteric liquid crystal composition.

[0197] In some embodiments of the present invention, the liquid crystal display device of the present invention may be a single-layer or multi-layer (eg, two-layer, three-layer, or four-layer, etc.) stacked liquid crystal display device.

[0198] In some embodiments of the present invention, the liquid crystal display device of the present invention may be a single-layer or multi-layer (eg, two-layer, three-layer, or four-layer, etc.) stacked cholesteric liquid crystal display device, which can achieve multi-color or color display.

[0199] In the present invention, the specific device structure of the liquid crystal display device does not limit the use of the cholesteric liquid crystal composition of the present invention, which can achieve a smaller wavelength drift, achieve better display quality in different temperature ranges, and have a wider operating temperature range.

[0200] In some embodiments of the present invention, the liquid crystal composition is particularly suitable for VA, IPS or FFS type display elements.

[0201] The present invention also provides an application of the cholesteric liquid crystal composition in a liquid crystal display panel, especially in an electronic book, an electronic label, a display panel, and an anti-peep screen.

[0202] Beneficial effects: Compared with the prior art, the cholesteric liquid crystal composition of the present invention has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature use range, which can make the liquid crystal display device containing it have a better display effect and a wider temperature use range. DETAILED DESCRIPTION

[0203] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0204] Unless otherwise specified, the performance parameters of the embodiments and comparative examples of the present invention are measured at room temperature.

[0205] For ease of expression, in the following examples, the group structure of each compound is represented by the code listed in Table 1:

[0206] Table 1. Group structure codes of compounds

[0207]

[0208] Take the following compound as an example:

[0209]

[0210] If the structural formula is represented by the codes listed in Table 1, it can be expressed as: nCCGF, where n in the code represents the number of C atoms in the left-end alkyl group, for example, n is "3", which means that the alkyl group is -C3H7; C in the code represents 1,4-cyclohexylene, G represents 2-fluoro-1,4-phenylene, and F represents fluorine.

[0211] The abbreviated codes for the test items in the following embodiments are as follows:

[0212] Cp 1 Clearing point of liquid crystal composition A (nematic-isotropic phase transition temperature, °C)

[0213] Cp 2 Clearing point of cholesteric liquid crystal composition (nematic-isotropic phase transition temperature, °C)

[0214] Δn optical anisotropy (589nm, 25℃)

[0215] n o Refractive index of ordinary light (589nm, 25℃)

[0216] n e Refractive index of extraordinary light (589nm, 25℃)

[0217] Δε Dielectric anisotropy (1KHz, 25℃)

[0218] P pitch (μm, 25℃)

[0219] λmax (0℃) The wavelength corresponding to the highest reflectivity in the reflectance spectrum detected at 0°C (nm)

[0220] λmax (10℃) The wavelength corresponding to the highest reflectivity in the reflectance spectrum detected at 10°C (nm)

[0221] λmax (20℃) The wavelength corresponding to the highest reflectivity in the reflectance spectrum detected at 20°C (nm)

[0222] λmax (30℃) The wavelength corresponding to the highest reflectivity in the reflectance spectrum detected at 30°C (nm)

[0223] λmax (40℃) The wavelength corresponding to the highest reflectivity in the reflection spectrum detected at 40°C (nm)

[0224] λmax (50℃) The wavelength corresponding to the highest reflectivity in the reflection spectrum detected at 50°C (nm)

[0225] λmax (60℃) The wavelength corresponding to the highest reflectivity in the reflection spectrum detected at 60°C (nm)

[0226] △λmax The wavelength variation range corresponding to the maximum reflectivity in the temperature range of 0℃~60℃ (nm)

[0227] △λmax (0℃) λmax (0℃) Relative to λmax (20℃) Ratio

[0228] △λmax (10℃) λmax (10℃) Relative to λmax (20℃) Ratio

[0229] △λmax (20℃) λmax (20℃) Relative to λmax (20℃) Ratio

[0230] △λmax (30℃) λmax (30℃) Relative to λmax (20℃) Ratio

[0231] △λmax (40℃) λmax (40℃) Relative to λmax (20℃) Ratio

[0232] △λmax (50℃) λmax (50℃) Relative to λmax (20℃) Ratio

[0233] △λmax (60℃) λmax (60℃) Relative to λmax (20℃) Ratio

[0234] in,

[0235] Cp 1 : Obtained by melting point test.

[0236] Cp 2 : Obtained by melting point test.

[0237] Δn: Δn=n e -n o , measured using an Abbe refractometer under a sodium lamp (589nm) at 25°C.

[0238] 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: 25°C, 1KHz, VA type test box with a box thickness of 6μm.

[0239] λmax: Pour cholesteric liquid crystal into the test box (box thickness: 4um; no PI alignment layer), use DMS 505 photoelectric comprehensive tester to test the P-state positive viewing angle test reflection spectrum, the wavelength corresponding to the highest reflectivity in the reflection spectrum, the detection temperature is 0℃, then it is recorded as λmax (0℃) , the detection temperature is 10℃, then it is recorded as λmax (10℃) , the detection temperature is 20℃, then it is recorded as λmax (20℃) , the detection temperature is 30℃, then it is recorded as λmax (30℃) , the detection temperature is 40℃, then it is recorded as λmax (40℃) , the detection temperature is 50℃, then it is recorded as λmax (50℃), the detection temperature is 60℃, then it is recorded as λmax (60℃) .

[0240] P=1 / (HTP·c), where c is the concentration of the chiral compound in the cholesteric liquid crystal composition, and HTP is the force with which the chiral compound twists the liquid crystal composition.

[0241] Each component used in the following examples can be synthesized by a known method or obtained through commercial channels. These synthesis techniques are conventional, and each liquid crystal compound obtained meets the standards of electronic compounds after testing.

[0242] The liquid crystal composition is prepared according to the ratio of each liquid crystal compound specified in the following examples. The preparation of the liquid crystal composition is carried out according to the conventional method in the art, such as mixing according to the ratio by heating, ultrasonic wave, suspension, etc.

[0243] LC1

[0244] Liquid crystal composition LC1 was prepared according to the compounds listed in Table 2 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0245] Table 2 Formulation and performance parameter test results of liquid crystal composition LC1

[0246]

[0247] LC2

[0248] The liquid crystal composition LC2 was prepared according to the compounds and their weight percentages listed in Table 3, and filled between two substrates of a liquid crystal display for performance testing.

[0249] Table 3 Formulation and performance parameter test results of liquid crystal composition LC2

[0250]

[0251]

[0252] LC3

[0253] Liquid crystal composition LC3 was prepared according to the compounds listed in Table 4 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0254] Table 4 Formulation and performance parameter test results of liquid crystal composition LC3

[0255]

[0256] LC4

[0257] Liquid crystal composition LC4 was prepared according to the compounds and their weight percentages listed in Table 5, and filled between two substrates of a liquid crystal display for performance testing.

[0258] Table 5 Formulation and performance parameter test results of liquid crystal composition LC4

[0259]

[0260]

[0261] LC5

[0262] Liquid crystal composition LC5 was prepared according to the compounds listed in Table 6 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0263] Table 6 Formulation and performance parameter test results of liquid crystal composition LC5

[0264]

[0265]

[0266] LC6

[0267] Liquid crystal composition LC6 was prepared according to the compounds listed in Table 7 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0268] Table 7 Formulation and performance parameter test results of liquid crystal composition LC6

[0269]

[0270] Comparative Example 1 and Example 1

[0271] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 8, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0272] Table 8 Test results of formulation and performance parameters of comparative example 1 and embodiment 1

[0273]

[0274]

[0275] From the comparison between Comparative Example 1 and Example 1, it can be seen that, relative to the cholesteric liquid crystal composition using only one chiral agent, the cholesteric liquid crystal composition of the present invention using three iso-rotatory chiral agents simultaneously has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0276] Comparative Example 2 and Example 2

[0277] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 9, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0278] Table 9 Test results of formulation and performance parameters of Comparative Example 2 and Example 2

[0279]

[0280] From the comparison between Comparative Example 2 and Example 2, it can be seen that, relative to the cholesteric liquid crystal composition using only one chiral agent, the cholesteric liquid crystal composition of the present invention using three iso-rotatory chiral agents simultaneously has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0281] Comparative Example 3 and Example 3

[0282] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 10, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0283] Table 10 Test results of formulation and performance parameters of comparative example 3 and embodiment 3

[0284]

[0285]

[0286] From the comparison between Comparative Example 3 and Example 3, it can be seen that, relative to the cholesteric liquid crystal composition using only one chiral agent, the cholesteric liquid crystal composition of the present invention using three isorotatory chiral agents simultaneously has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0287] Comparative Example 4 and Example 4

[0288] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 11, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0289] Table 11 Test results of formulation and performance parameters of comparative example 4 and embodiment 4

[0290]

[0291] From the comparison between Comparative Example 4 and Example 4, it can be seen that, relative to the cholesteric liquid crystal composition using only two chiral agents, the cholesteric liquid crystal composition of the present invention using three isorotatory chiral agents simultaneously has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0292] Comparative Example 5 and Example 5

[0293] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 12, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0294] Table 12 Formulation and performance parameter test results of Comparative Example 5 and Example 5

[0295]

[0296] From the comparison between Comparative Example 5 and Example 5, it can be seen that, relative to the cholesteric liquid crystal composition using only two chiral agents, the cholesteric liquid crystal composition of the present invention using three isorotatory chiral agents simultaneously has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0297] Comparative Example 6 and Example 6

[0298] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 13, and filled between two substrates of a liquid crystal display for performance testing (without a PI alignment layer).

[0299] Table 13 Formulation and performance parameter test results of Comparative Example 6 and Example 6

[0300]

[0301] From the comparison between Comparative Example 6 and Example 6, it can be seen that, relative to the cholesteric liquid crystal composition using only two chiral agents, the cholesteric liquid crystal composition of the present invention using three isorotatory chiral agents at the same time has an appropriate clearing point and a smaller wavelength change with temperature (the closer △λmax is to 1, the smaller the wavelength drift), that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift and a wider temperature usage range.

[0302] In summary, the cholesteric liquid crystal composition of the present invention has an appropriate clearing point and a smaller wavelength variation with temperature, that is, the cholesteric liquid crystal composition of the present application has a smaller wavelength drift, which enables the liquid crystal display device containing it to have a better display effect and a wider temperature operating range.

[0303] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A cholesteric liquid crystal composition, characterized in that: The cholesteric liquid crystal composition comprises at least one liquid crystal composition A and at least three chiral agents. Wherein, the liquid crystal composition A comprises at least one compound of the general formula I and at least one compound of the general formula II: as well as At least one chiral agent is R / S-2011: in, R T1 and R T2 Each independently represents -H, a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; R C1 represents -H, a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl; ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1 to 3 carbon atoms, and -CH= in one or more rings may be replaced by -N=; Z T1 and Z C1 Each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; L T1 , L T2 , L C1 and L C2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 carbon atoms; L T3 and L C3 Each independently represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms; n T1 Represents 0, 1, or 2. When n T1 =2, ring Can be the same or different, Z T1 Can be the same or different; n C1 Represents 0, 1, 2, or 3. When n C1 =2 or 3, the ring Can be the same or different, Z C1 may be the same or different; and * indicates chiral site.

2. The cholesteric 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: as well as The compound of formula II is selected from the group consisting of the following compounds: as well as in, Z T1 ', Z C1 ' and Z C2 Each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-; L T1 , L T2 , L C1 and L C2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3; L T3 and L C3 each independently represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3; and ring express in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently substituted by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1 to 3 carbon atoms, and -CH= in one or more rings may be replaced by -N=.

3. The cholesteric liquid crystal composition according to claim 2, characterized in that: The compound of formula I is selected from the group consisting of the following compounds: as well as The compound of formula II is selected from the group consisting of the following compounds: as well as in, L T1 ', L T2 ', L C1 ' and L C2 'Each independently represents -F, -Cl, -CF3, or -OCF3; L T4 ', L T5 ' and L T6 'Each independently represents -F, -Cl, -CH3, or -OCH3; and L C4 and L C5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

4. The cholesteric liquid crystal composition according to claim 1, characterized in that: The weight percentage of the compound of general formula I in liquid crystal composition A is 0.1%-70%, the weight percentage of the compound of general formula II in liquid crystal composition A is 0.1%-80%; the weight percentage of the chiral agent in cholesteric liquid crystal composition is 0.1%-20%.

5. The cholesteric liquid crystal composition according to claim 1, characterized in that: The chiral agent may also include at least two chiral agents selected from the group consisting of R / S-811, R / S-1011, R / S-5011, and R / S-6N: as well as Wherein, * indicates chiral site.

6. The cholesteric liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition A further comprises at least one compound of the general formula M: in, R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or the branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, 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-, -CH=CH-, -CH2CH2- or -(CH2)4-; and n M represents 0, 1, or 2, where n M =2, ring Can be the same or different, Z M2 Can be the same or different.

7. The cholesteric liquid crystal composition according to claim 6, characterized in that: The liquid crystal composition A further comprises at least one compound of the general formula A-1 and / or the general formula A-2: in, R A1 and R A2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms, a branched-chain alkyl group containing 3 to 12 carbon atoms, One or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or more -H in the straight-chain alkyl group containing 1-12 carbon atoms or the branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl; ring ring ring and ring Each independently expresses in One or more -CH2- in the ring may be replaced by -O-, and one or at most two single bonds in the ring may be replaced by double bonds, wherein One or more -H in the ring may be independently replaced by -F, -Cl or -CN, and one or more -CH= in the ring may be replaced by -N=; Z A11 , Z A21 and Z A22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-; L A11 , L A12 , L A13 , L A21 and L A22 Each independently represents -H, an alkyl group containing 1 to 3 carbon atoms or a halogen; X A1 and X A2 Each independently represents halogen, a haloalkyl or haloalkoxy group containing 1 to 5 carbon atoms, a haloalkenyl or haloalkenyloxy group containing 2 to 5 carbon atoms; n A11 Represents 0, 1, 2, or 3. When n A11 =2 or 3, the ring Can be the same or different, Z A11 Can be the same or different; n A12 represents 1 or 2, where n A12 =2, ring may be the same or different; and n A2 represents 0, 1, 2, or 3, where n A2 =2 or 3, the ring Can be the same or different, Z A21 Can be the same or different.

8. The cholesteric liquid crystal composition according to claim 7, characterized in that: The compound of formula M is selected from the group consisting of the following compounds: as well as The compound of formula A-1 is selected from the group consisting of the following compounds: as well as The compound of formula A-2 is selected from the group consisting of the following compounds: as well as in, R M1 and R M2 Each independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms, and one or more non-adjacent -CH2- in the straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-; R v and R w Each independently represents -CH2- or -O-; L A11 , L A12 , L A11 ', L A12 ', L A14 , L A15 , L A16 , L A21 , L A22 , L A23 , L A24 and L A25 Each independently represents -H or -F; L A13 and L A13 'Each independently represents -H or -CH3; X A1 represents -F, -CF3 or -OCF3; v and w each independently represent 0 or 1; and X A2 It represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

9. A liquid crystal display device comprising the cholesteric liquid crystal composition according to any one of claims 1 to 8.

10. The liquid crystal display device according to claim 9, characterized in that: The liquid crystal display device may be a single-layer or multi-layer stacked liquid crystal display device.

11. Use of the cholesteric liquid crystal composition according to any one of claims 1 to 8 in a liquid crystal display panel.

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