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, at least one chiral agent and at least one dye, and the liquid crystal composition A comprises at least one compound as shown in a general formula I and at least one compound as shown in a general formula II. The cholesteric liquid crystal composition disclosed by the invention has a relatively high clearing point, a relatively good contrast ratio and a smaller lambda max under the condition of maintaining a relatively small P-state voltage, that is, the reflection wavelength change of a side view angle (45 degrees) of the cholesteric liquid crystal composition disclosed by the invention is smaller. # 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] Existing cholesteric liquid crystals have an obvious viewing angle effect in the plane state reflection wavelength, that is, the side viewing angle reflection wavelength is significantly smaller than the front viewing angle reflection wavelength, which is manifested as a significant difference in the side viewing angle reflection color and the front viewing angle, resulting in a significant visual color bias in the reflective device made of cholesteric liquid crystal.

[0007] At the same time, the existing cholesteric liquid crystal display has a low contrast ratio (CR = R 平面态 / R 焦锥态 ), in the focal conic state, due to the large refractive index of the liquid crystal, the focal conic state liquid crystal display is obviously foggy, resulting in a relatively high focal conic state reflectivity, which greatly reduces the contrast of the cholesteric liquid crystal display.

[0008] How to solve the above problems is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0009] Purpose of the invention: The purpose of the present invention is to provide a cholesteric liquid crystal composition. The cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage, that is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°).

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

[0011] as well as

[0012]

[0013] in,

[0014] 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 a straight-chain alkyl group containing 1 to 12 carbon atoms or a branched-chain alkyl group containing 3 to 12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0015] 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 a straight-chain alkyl group containing 1-12 carbon atoms or a 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 a straight-chain alkyl group containing 1-12 carbon atoms or a branched-chain alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0016] 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=;

[0017] 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-;

[0018] 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;

[0019] 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;

[0020] n T1 Represents 0, 1, or 2. When n T1 =2, ring Can be the same or different, Z T1 may be the same or different; and

[0021] n C1 Represents 0, 1, 2, or 3. When n C1 =2 or 3, the ring Can be the same or different, Z C1 Can be the same or different.

[0022] In some embodiments of the present invention, the ring and ring Each independently expresses

[0023] In some embodiments of the present invention, R T1 and R T2Preferably, 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.

[0024] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0025]

[0026] as well as

[0027]

[0028] in,

[0029] Z T1 ' represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-;

[0030] L T1 and L T2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3; and

[0031] L T3 It represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3.

[0032] In some embodiments of the present invention, Z T1 ' represents -CO-O-, -CH=CH- or -C≡C-.

[0033] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0034]

[0035]

[0036]

[0037] as well as

[0038]

[0039] in,

[0040] L T1 ' and LT2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0041] L T4 ',L T5 ' and L T6 'Each independently represents -F, -Cl, -CH3, or -OCH3.

[0042] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and a smaller Δλmax, the compound of general formula I 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.

[0043] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and smaller Δλmax, the compound of general formula I preferably comprises 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:

[0044]

[0045]

[0046] as well as

[0047]

[0048] in,

[0049] R T1 ' and R T2 'Each independently represents -H or a straight-chain alkyl group containing 1 to 6 carbon atoms; and

[0050] R T2 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0051] 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 higher clearing point, better contrast and smaller Δλmax.

[0052] 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%.

[0053] 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.

[0054] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0055]

[0056] as well as

[0057]

[0058] in,

[0059] Z C1 ' and Z C2 Each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-;

[0060] L C1 and L C2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3; L C3 represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3; and

[0061] 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=.

[0062] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] as well as

[0072]

[0073] in,

[0074] L C1 ' and L C2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0075] L C4 and L C5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

[0076] In some embodiments of the present invention, Z C1 ' represents -CO-O- or -O-CO-.

[0077] In some embodiments of the present invention, Z C2 It means -CO-O- or -O-CO-.

[0078] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and a smaller △λmax, the compound of general formula II contains at least one (for example, two, three, four, five, or six, 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.

[0079] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and smaller Δλmax, 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- A compound of the group consisting of a compound of formula II-14-3, a compound of formula II-2-15-1, a compound of formula II-2-15-2, a compound of formula II-2-15-3, a compound of formula II-2-15-4, a compound of formula II-2-15-5, a compound of formula II-2-15-6, a compound of formula II-3-2-1, a compound of formula II-3-3-1, a compound of formula II-5-1-1, and a compound of formula II-5-2-1:

[0080]

[0081]

[0082]

[0083] as well as

[0084]

[0085] in,

[0086] R C1 ' represents -H, or a straight-chain alkyl group containing 1 to 6 carbon atoms; and

[0087] R C1 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0088] 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 higher clearing point, a better contrast ratio and a smaller Δλmax.

[0089] 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%.

[0090] In some embodiments of the present invention, the chiral agent of the present invention can be any one or a combination of at least two of the following compounds:

[0091]

[0092]

[0093] as well as

[0094]

[0095] Wherein, * indicates chiral site.

[0096] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and smaller Δλmax, the chiral agent of the present invention comprises at least one chiral agent selected from the group consisting of R / S-5011, CB 15, R / S-811, R / S-2011 and R / S-6N.

[0097] In some embodiments of the present invention, the weight percentage of the chiral agent in the cholesteric liquid crystal composition is 0.1%-50% (including any value or sub-range between the ranges), 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%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, or a range between any two of the values.

[0098] In some embodiments of the present invention, when the chiral agent is R / S-5011, its weight percentage of the cholesteric liquid crystal composition is 1%-10% (including any value or sub-range between the range), for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two values.

[0099] In some embodiments of the present invention, when the chiral agent is CB 15, its weight percentage of the cholesteric liquid crystal composition is 30%-40% (including any numerical value or sub-range between the range), for example, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, or the range between any two values.

[0100] In some embodiments of the present invention, when the chiral agent is R / S-811, its weight percentage of the cholesteric liquid crystal composition is 20%-30% (including any numerical value or sub-range between the range), for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or a range between any two of the numerical values.

[0101] In some embodiments of the present invention, when the chiral agent is R / S-2011, its weight percentage of the cholesteric liquid crystal composition is 20%-30% (including any numerical value or sub-range between the range), for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or a range between any two of the numerical values.

[0102] In some embodiments of the present invention, when the chiral agent is R / S-6N, its weight percentage of the cholesteric liquid crystal composition is 1%-10% (including any value or sub-range between the range), for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two values.

[0103] In the present invention, by adding dyes into the cholesteric liquid crystal composition, the problem of color deviation of the side-viewing color in the reflective device in the prior art is creatively solved, and a better contrast ratio is achieved, thereby realizing a better display effect.

[0104] In some embodiments of the present invention, the dye is one or more dyes selected from the group consisting of azo, anthraquinone, phthalocyanine, cyanine, indigoid, arylmethane, nitro, and nitroso.

[0105] In some embodiments of the present invention, the dye is selected from the group consisting of azo and anthraquinone.

[0106] In some embodiments of the present invention, the dye is selected from one or a combination of at least two (e.g., three, four, or five) of the following compounds:

[0107]

[0108]

[0109]

[0110]

[0111] In some embodiments of the present invention, in order to obtain a higher clearing point, better contrast and smaller Δλmax, the dye is preferably selected from the group consisting of dyes corresponding to dye numbers 1, 5, 12, 13, 14, 21, and 34.

[0112] In some embodiments of the present invention, the weight percentage of the dye added to the cholesteric liquid crystal composition is 0.01%-10% (including any value or sub-range between the range), for example, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, 3.2%, 3.5%, 3.8%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93% 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, 6%, 6.2%, 6.5%, 6.8%, 7%, 7.2%, 7.5%, 7.8%, 8%, 8.2%, 8.5%, 8.8%, 9%, 9.2%, 9.5%, 9.8%, 10%, or a range between any two values; preferably 0.2%-6%, more preferably 0.2%-4%.

[0113] 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:

[0114]

[0115] in,

[0116] 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;

[0117] 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=;

[0118] Z S1represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0119] 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;

[0120] L S3 represents -H, alkyl or alkoxy containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms; and

[0121] 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.

[0122] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0123]

[0124] as well as

[0125]

[0126] in,

[0127] L S1 and L S2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3;

[0128] 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

[0129] 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=.

[0130] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0131]

[0132]

[0133]

[0134]

[0135]

[0136] as well as

[0137]

[0138] in,

[0139] L S1 ' and L S2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0140] L S4 and L S5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

[0141] 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.

[0142] 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%.

[0143] In some embodiments of the invention, halogen each independently represents -F, -Cl or -Br.

[0144] 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:

[0145]

[0146] in,

[0147] 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-;

[0148] 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;

[0149] Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2- or -(CH2)4-; and

[0150] 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.

[0151] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of:

[0152]

[0153]

[0154]

[0155]

[0156] as well as

[0157]

[0158] 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-.

[0159] 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.

[0160] 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.

[0161] In some embodiments of the present invention, R M1 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.

[0162] 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:

[0163]

[0164] in,

[0165] R A1 and R A2Each 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;

[0166] 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=;

[0167] 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-;

[0168] 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;

[0169] 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;

[0170] n A11 Represents 0, 1, 2, or 3. When n A11 =2 or 3, the ring Can be the same or different, Z A11Can be the same or different;

[0171] n A12 represents 1 or 2, where n A12 =2, ring may be the same or different; and

[0172] 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.

[0173] 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.

[0174] In some embodiments of the present invention, the compound of formula A-1 is selected from the group consisting of the following compounds:

[0175]

[0176]

[0177]

[0178] as well as

[0179] in,

[0180] R v and R w Each independently represents -CH2- or -O-;

[0181] L A11 , L A12 , L A11 ',L A12 ',L A14 , L A15 and L A16 Each independently represents -H or -F;

[0182] LA13 and L A13 'Each independently represents -H or -CH3;

[0183] X A1 represents -F, -CF3 or -OCF3; and

[0184] v and w each independently represent 0 or 1.

[0185] 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.

[0186] In some embodiments of the present invention, the compound of formula A-2 is selected from the group consisting of:

[0187]

[0188]

[0189]

[0190] as well as

[0191]

[0192] in,

[0193] L A21 , L A22 , L A23 , L A24 and L A25 each independently represents -H or -F; and

[0194] X A2 It represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] In addition, the antioxidants, light stabilizers and other additives used in the liquid crystal composition of the present invention are preferably the following:

[0199]

[0200]

[0201]

[0202] Here, n represents a positive integer from 1 to 12.

[0203] Preferably, the antioxidant is selected from the light stabilizers shown below:

[0204]

[0205] 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.

[0206] In some embodiments of the present invention, the weight percentage of liquid crystal composition A in the cholesteric liquid crystal composition is 60%-99% (including any numerical value or sub-range between the range), for example, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 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.

[0207] The present invention also provides a liquid crystal display device comprising the cholesteric liquid crystal composition.

[0208] In some embodiments of the present invention, the liquid crystal composition is particularly suitable for VA, IPS or FFS type display elements.

[0209] The present invention also provides the use of the cholesteric liquid crystal composition in a liquid crystal display panel, especially in an electronic book, an electronic label, a display panel, an anti-peep screen, etc.

[0210] Beneficial effect: Compared with the prior art, the cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage, that is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°). DETAILED DESCRIPTION

[0211] 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.

[0212] Unless otherwise specified, the performance parameters of the embodiments and comparative examples of the present invention are measured at room temperature.

[0213] For ease of expression, in the following examples, the group structure of each compound is represented by the code listed in Table 1:

[0214] Table 1. Group structure codes of compounds

[0215]

[0216] Take the following compound as an example:

[0217]

[0218] 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.

[0219] The abbreviated codes for the test items in the following embodiments are as follows:

[0220] Cp 1 Clearing point of liquid crystal composition A (nematic phase-isotropic phase transition temperature, °C)

[0221] Cp 2 Clearing point of cholesteric liquid crystal composition (nematic-isotropic phase transition temperature, °C)

[0222] Δn optical anisotropy (589nm, 25℃)

[0223] n o Refractive index of ordinary light (589nm, 25℃)

[0224] n e Refractive index of extraordinary light (589nm, 25℃)

[0225] Δε Dielectric anisotropy (1KHz, 25℃)

[0226] λmax The wavelength corresponding to the highest reflectivity in the reflection spectrum (25℃)

[0227] λmax(45°) P state 45° viewing angle test reflection spectrum, the wavelength corresponding to the highest reflectivity in the reflection spectrum (25℃)

[0228] △λmax wavelength change (25℃)

[0229] The minimum voltage required to drive the P-state voltage to the P-state (V, 25°C)

[0230] R 平面态 Reflectivity at normal viewing angle driven to planar state

[0231] R 焦锥态 Reflectivity at normal viewing angle driven to focal conic state

[0232] CR contrast ratio (R 平面态 / R 焦锥态 )

[0233] in,

[0234] Cp 1 : Obtained by melting point test.

[0235] Cp 2 : Obtained by melting point test.

[0236] Δn: Δn=n e -n o , measured using an Abbe refractometer under a sodium lamp (589nm) at 25°C.

[0237] 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.

[0238] λmax: Cholesteric liquid crystal is poured into a test box (box thickness: 4um; no PI alignment layer), and the DMS 505 photoelectric comprehensive tester is used to test the P-state positive viewing angle test reflection spectrum, which is the wavelength corresponding to the highest reflectivity in the reflection spectrum.

[0239] λmax(45°): Cholesteric liquid crystal is poured into a test box (box thickness: 4um; no PI alignment layer), and the reflection spectrum is tested using a DMS 505 photoelectric integrated tester at a 45° viewing angle in the P state. The wavelength corresponding to the highest reflectivity in the reflection spectrum.

[0240] △λmax: λmax-λmax (45°).

[0241] P-state voltage: Cholesteric liquid crystal is poured into a test box (box thickness: 4 um; no PI alignment layer) and driven to the minimum voltage required for the P-state.

[0242] R 平面态 : Cholesteric liquid crystal was poured into a test box (box thickness: 4um; no PI alignment layer), and the DMS 505 photoelectric comprehensive tester was used to test the positive viewing angle reflectivity when driven to the planar state.

[0243] R 焦锥态 : Cholesteric liquid crystal was poured into a test box (box thickness: 4um; no PI alignment layer), and the DMS 505 photoelectric comprehensive tester was used to test the normal viewing angle reflectivity driven to the focal cone state.

[0244] 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.

[0245] 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.

[0246] LC1

[0247] 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.

[0248] Table 2 Formulation and performance parameter test results of liquid crystal composition LC1

[0249]

[0250] LC2

[0251] 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.

[0252] Table 3 Formulation and performance parameter test results of liquid crystal composition LC2

[0253]

[0254]

[0255] LC3

[0256] 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.

[0257] Table 4 Formulation and performance parameter test results of liquid crystal composition LC3

[0258]

[0259] LC4

[0260] 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.

[0261] Table 5 Formulation and performance parameter test results of liquid crystal composition LC4

[0262]

[0263] LC5

[0264] 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.

[0265] Table 6 Formulation and performance parameter test results of liquid crystal composition LC5

[0266]

[0267]

[0268] LC6

[0269] 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.

[0270] Table 7 Formulation and performance parameter test results of liquid crystal composition LC6

[0271]

[0272] DLC1

[0273] The liquid crystal composition DLC1 was prepared according to the compounds listed in Table 8 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0274] Table 8 Formulation and performance parameter test results of liquid crystal composition DLC1

[0275]

[0276]

[0277] DLC2

[0278] The liquid crystal composition DLC2 was prepared according to the compounds listed in Table 9 and their weight percentages, and filled between two substrates of a liquid crystal display for performance testing.

[0279] Table 9 Formulation and performance parameter test results of liquid crystal composition DLC2

[0280]

[0281]

[0282] Comparative Examples 1-3 and Examples 1-3

[0283] 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).

[0284] Table 10 Formulation and performance parameter test results of cholesteric liquid crystal composition

[0285]

[0286] Among them, dye 14 in Table 10 refers to the dye corresponding to dye number 14.

[0287] From the comparison between Comparative Examples 1-2 and Examples 1-3, it can be seen that compared with other liquid crystal compositions, the cholesteric liquid crystal composition using the liquid crystal composition A of the present invention as the main liquid crystal has a higher clearing point, better contrast, a smaller P-state voltage and a smaller △λmax, that is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°), which can effectively improve the problem of color deviation at the side viewing angle, and can be switched to the P state under a smaller voltage drive, which is more energy-efficient.

[0288] From the comparison between Comparative Example 3 and Examples 1-3, it can be seen that the cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage through the synergistic coordination of the various components. That is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°).

[0289] Comparative Examples 4-8 and Examples 4-8

[0290] 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).

[0291] Table 11 Formulation and performance parameter test results of cholesteric liquid crystal composition

[0292]

[0293] Among them, Dye 1, Dye 9, Dye 12, Dye 21, Dye 13, Dye 5, and Dye 34 in Table 11 refer to dyes corresponding to dye numbers 1, 9, 12, 21, 13, 5, and 34, respectively.

[0294] From the comparison of the data of the embodiments and the comparative examples in Table 11, it can be seen that the cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage through the synergistic coordination of the various components. That is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°).

[0295] Examples 9-13

[0296] 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).

[0297] Table 12 Formulation and performance parameter test results of cholesteric liquid crystal composition

[0298]

[0299]

[0300] Among them, dye 14 in Table 12 refers to the dye corresponding to dye number 14.

[0301] From the data comparison of Table 12, it can be seen that the cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage through the synergistic coordination of the various components, that is, the cholesteric liquid crystal composition of the present invention has a smaller change in the side viewing angle (45°) reflection wavelength. When the chiral agent is R / S-2011, R / S-5011 or R / S-6N, the cholesteric liquid crystal composition containing it has a higher clearing point, better contrast and smaller Δλmax.

[0302] In summary, the cholesteric liquid crystal composition of the present invention has a higher clearing point, better contrast and smaller Δλmax while maintaining a smaller P-state voltage through the synergistic coordination of various components. That is, the cholesteric liquid crystal composition of the present invention has a smaller change in the reflection wavelength at the side viewing angle (45°).

[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, at least one chiral agent and at least one dye, wherein the liquid crystal composition A comprises at least one compound of general formula I and at least one compound of general formula II: as well as 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 may be the same or different; and n C1 Represents 0, 1, 2, or 3. When n C1 =2 or 3, the ring Can be the same or different, Z C1 Can be the same or different.

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 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%, and the weight percentage of the added amount of the dye to the added amount of the cholesteric liquid crystal composition is 0.01%-10%.

5. The cholesteric liquid crystal composition according to claim 1, characterized in that: The chiral agent can be any one or a combination of at least two of the following compounds: as well as Wherein, * indicates chiral site.

6. The cholesteric liquid crystal composition according to claim 1, characterized in that: The dye is selected from one or a combination of at least two of the following compounds:

7. 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.

8. The cholesteric liquid crystal composition according to claim 7, 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.

9. The cholesteric liquid crystal composition according to claim 8, 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.

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

11. Use of the cholesteric liquid crystal composition according to any one of claims 1 to 9 in a liquid crystal display panel.

Images