Liquid crystal composition and liquid crystal display device thereof

Abstract

The invention provides a liquid crystal display device, the liquid crystal display device comprises at least one layer of display panel, the display panel sequentially comprises a first substrate, a first conducting layer, a first alignment layer, a cholesteric liquid crystal composition layer, a second alignment layer, a second conducting layer and a second substrate from top to bottom, the first alignment layer and the second alignment layer are in vertical alignment, and the friction direction is up-down anti-parallel friction. The liquid crystal display device provided by the invention has narrower half-peak width under the condition of equivalent lambda max, so that the reflected color is brighter and the purity is higher.

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 when in the planar state (the specific wavelength is generally the wavelength corresponding to the highest reflectivity in the reflection spectrum, i.e., λmax), 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-peak width (△λ) of the selective reflection 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-peak 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] In existing cholesteric liquid crystals, the planar reflection spectrum △λ is large and the planar reflectivity is high, but the planar reflection color saturation and brightness are poor. Visually, the reflection color is not bright enough or even colorless, which greatly limits the application of cholesteric liquid crystals in color displays.

[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 liquid crystal display device, which has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color is brighter and has higher purity.

[0009] Technical solution: In order to achieve the above invention objectives, the present invention provides a liquid crystal display device, which includes at least one layer (for example, it can be two layers, three layers, four layers, etc.) of display panel, and the display panel includes, from top to bottom, a first substrate, a first conductive layer, a first alignment layer, a cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer and a second substrate; wherein the first alignment layer and the second alignment layer are vertically aligned, and the rubbing direction is up and down anti-parallel rubbing.

[0010] In some embodiments of the present invention, the liquid crystal display device of the present invention comprises a first display panel and a second display panel, the first display panel and the second display panel share a second substrate, the first display panel comprises, from top to bottom, a first substrate, a first conductive layer, a first alignment layer, a first cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer, and a second substrate, and the second display panel comprises, from top to bottom, a second substrate, a third conductive layer, a third alignment layer, a second cholesteric liquid crystal composition layer, a fourth alignment layer, a fourth conductive layer, and a third substrate; wherein the first alignment layer and the second alignment layer are vertically aligned, and the rubbing direction is up-and-down antiparallel rubbing, and the third alignment layer and the fourth alignment layer are vertically aligned, and the rubbing direction is up-and-down parallel rubbing or up-and-down antiparallel rubbing.

[0011] In some embodiments of the present invention, the third alignment layer and the fourth alignment layer are vertically aligned, and the rubbing direction is up and down anti-parallel rubbing.

[0012] In some embodiments of the present invention, the first alignment layer, the second alignment layer, the third alignment layer, and the fourth alignment layer each independently comprise polyimide, a polymeric derivative of polyamic acid that is photodegradable or exsitu, or a polyorganosiloxane compound.

[0013] In some embodiments of the present invention, the first substrate, the second substrate and the third substrate are each independently glass or a polymer. Preferably, the first substrate, the second substrate and the third substrate are each independently glass, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polycarbonate (PC), or polyimide (PI).

[0014] In some embodiments of the present invention, a light absorbing layer, preferably a black light absorbing layer, may be further provided on the lower side of the second substrate or the third substrate.

[0015] In some embodiments of the present invention, the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer are each independently a transparent conductive oxide (TCO). Preferably, the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer are each independently ITO or SnO2:F.

[0016] In the present invention, the inventors make the liquid crystal display device of the present invention have a narrower half-peak width by selecting the alignment direction and rubbing direction of the alignment layers arranged in parallel in the liquid crystal display device, thereby making the reflected color brighter and purer.

[0017] In the present invention, the term "cholesteric liquid crystal composition layer", when not limited to "first" or "second", independently applies to the "first cholesteric liquid crystal composition layer" or the "second cholesteric liquid crystal composition layer".

[0018] In some embodiments of the present invention, the cholesteric liquid crystal composition layer of the present invention comprises at least one chiral agent selected from the group consisting of formula R / S-811, formula R / S-1011, formula R / S-2011, formula R / S-5011 and formula R / S-6N:

[0019]

[0020] as well as

[0021]

[0022] Wherein, * indicates chiral site.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] In some embodiments of the present invention, the cholesteric liquid crystal composition layer of the present invention comprises at least one chiral agent selected from the group consisting of formula R / S-811, formula R / S-2011, formula R / S-5011 and formula R / S-6N, preferably formula R / S-2011 or formula R / S-5011.

[0029] In some embodiments of the present invention, the cholesteric liquid crystal composition further comprises at least one compound of formula I:

[0030]

[0031] in,

[0032] 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-;

[0033] 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=;

[0034] Z T1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0035] L T1 and L T2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 (e.g., 1, 2 or 3) carbon atoms;

[0036] L T3 represents -H, alkyl or alkoxy containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms; and

[0037] 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.

[0038] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0039]

[0040] as well as

[0041]

[0042] in,

[0043] Z T1 ' represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-;

[0044] L T1 and L T2Each independently represents -H, -F, -Cl, -CF3, or -OCF3; and

[0045] L T3 It represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3.

[0046] In some embodiments of the present invention, Z T1 ' represents -CO-O-, -CH=CH- or -C≡C-.

[0047] 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.

[0048] In some embodiments of the present invention, the compound of formula I is selected from the group consisting of:

[0049]

[0050]

[0051]

[0052] as well as

[0053]

[0054] in,

[0055] L T1 ' and L T2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0056] L T4 ',L T5 ' and L T6 'Each independently represents -F, -Cl, -CH3, or -OCH3.

[0057] In some embodiments of the present invention, in order to obtain a narrower half-peak width, the compound of general formula I is selected from the group consisting of compounds of general formula I-1-1, compounds of general formula I-2-1, compounds of general formula I-2-6, and compounds of general formula I-3-3.

[0058] In some embodiments of the present invention, in order to obtain a narrower half-peak width, the compound of general formula I is 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-2-6-1, compounds of general formula I-3-3-1, compounds of general formula I-3-3-2:

[0059]

[0060]

[0061] as well as

[0062]

[0063] in,

[0064] R T1 ' and R T2 'Each independently represents -H or a straight-chain alkyl group containing 1 to 6 carbon atoms; and

[0065] R T2 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0066] In the present invention, it is preferred to adjust the content of the compound of formula I so that the liquid crystal display device containing the compound has a narrower half-peak width.

[0067] In some embodiments of the present invention, the weight percentage of the compound of formula I in the cholesteric liquid crystal composition is 0.1%-70% (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%, 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%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 100%, 100%, 100%, 100%, 100%, 32%, 34%, 35%, 36%, 38%, 40%, 42%, 43%, 44%, 46%, 48%, 49%, 50%, 52%, 54%, 56%, 57%, 58%, 59%, 60%, 62%, 64%, 66%, 68%, 70%, or any range between two values; preferably, the weight percentage of the compound of formula I in the cholesteric liquid crystal composition is 30%-60%.

[0068] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention further comprises at least one compound of formula II:

[0069]

[0070] in,

[0071] 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;

[0072] 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=;

[0073] Z C1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0074] 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;

[0075] L C3 represents -H, alkyl or alkoxy containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms; and

[0076] 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.

[0077] 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.

[0078] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0079]

[0080]

[0081] as well as

[0082]

[0083] in,

[0084] Z C1 ' and Z C2 Each independently represents -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, or -(CH2)4-;

[0085] L C1 and L C2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3;

[0086] L C3 represents -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3; and

[0087] 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=.

[0088] In some embodiments of the present invention, the compound of formula II is selected from the group consisting of:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] as well as

[0098]

[0099] in,

[0100] L C1 ' and L C2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0101] L C4 and L C5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

[0102] In some embodiments of the present invention, in order to obtain a narrower half-width, the compound of general formula II is 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, and compounds of general formula II-3-3.

[0103] In some embodiments of the present invention, in order to obtain a narrower half-width, the compound of general formula II is selected from the group consisting of compounds of general formula II-1-1, compounds of general formula II-2-14-1, compounds of general formula II-2-14-2, compounds of general formula II-2-14-3, compounds of general formula II-2-15-1, compounds of general formula II-2-15-2, compounds of general formula II-2-15-3, compounds of general formula II-2-15-4, compounds of general formula II-2-15-5, compounds of general formula II-3-2-1, compounds of general formula II-3-3-1:

[0104]

[0105]

[0106] as well as

[0107]

[0108] in,

[0109] R C1 ' represents -H, or a straight-chain alkyl group containing 1 to 6 carbon atoms; and

[0110] R C1 " represents a straight chain alkyl group containing 1 to 6 carbon atoms.

[0111] In the present invention, it is preferred to adjust the content of the compound of formula II so that the liquid crystal display device containing the compound has a narrower half-peak width.

[0112] In some embodiments of the present invention, the weight percentage of the compound of formula II in the cholesteric liquid crystal composition 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%, 27%, 28%, 30%, 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%, 94%, 95%, 96%, 97%, 98%, 99%, 10 ... 34%, 35%, 36%, 38%, 40%, 42%, 43%, 44%, 46%, 47%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, 68%, 70%, 72%, 74%, 76%, 78%, 80%, or a range between any two of these values; preferably, the weight percentage of the compound of formula II in the cholesteric liquid crystal composition is 20%-70%.

[0113] In some embodiments of the present invention, the ring and ring Each independently expresses

[0114]

[0115] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention further comprises at least one compound of formula III:

[0116]

[0117] in,

[0118] R S1represents 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 1-12 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;

[0119] 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=;

[0120] Z S1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-;

[0121] 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;

[0122] L S3 represents -H, alkyl or alkoxy containing 1 to 3 (e.g. 1, 2 or 3) carbon atoms; and

[0123] 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.

[0124] In some embodiments of the present invention, R S1Preferably, 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.

[0125] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0126]

[0127] as well as

[0128]

[0129] in,

[0130] L S1 and L S2 Each independently represents -H, -F, -Cl, -CF3, or -OCF3;

[0131] 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

[0132] 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=.

[0133] In some embodiments of the present invention, the compound of formula III is selected from the group consisting of:

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] as well as

[0140]

[0141] in,

[0142] L S1 ' and L S2 'Each independently represents -F, -Cl, -CF3, or -OCF3; and

[0143] L S4 and L S5 Each independently represents -H, -F, -Cl, -CF3, or -OCF3.

[0144] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention comprises at least one compound of the general formula III-1-6.

[0145] In some embodiments of the present invention, the weight percentage of the compound of formula III in the cholesteric liquid crystal composition 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.

[0146] In some embodiments of the invention, each halogen independently represents -F, -Cl or -Br.

[0147] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention further comprises at least one compound of the general formula M:

[0148]

[0149] in,

[0150] 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 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-;

[0151] 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 At most one -H in may be replaced by halogen;

[0152] Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2- or -(CH2)4-; and

[0153] 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.

[0154] In some embodiments of the present invention, the compound of formula M is selected from the group consisting of:

[0155]

[0156]

[0157]

[0158]

[0159]

[0160] as well as

[0161]

[0162] 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. One or two or more non-adjacent -CH2- in the straight-chain alkyl group containing 1-12 carbon atoms or a 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-.

[0163] In some embodiments of the present invention, the compound of formula M-1 is selected from the group consisting of:

[0164]

[0165] in,

[0166] R M1 ' and R M2 ' each independently represents a straight-chain alkyl group containing 1 to 5 (eg, 1, 2, 3, 4 or 5) carbon atoms.

[0167] In some embodiments of the present invention, the compound of formula M-5 is selected from the group consisting of:

[0168]

[0169] in,

[0170] R M1 ' and R M2 ' each independently represents a straight-chain alkyl group containing 1 to 5 (eg, 1, 2, 3, 4 or 5) carbon atoms.

[0171] In some embodiments of the present invention, the weight percentage of the compound of general formula M in the cholesteric liquid crystal composition is 0.1%-30% (including any value or sub-range between the range), for example, 0.1%, 1%, 2%, 4%, 5%, 6%, 8%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or the range between any two values.

[0172] 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.

[0173] 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.

[0174] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention further comprises at least one compound of the general formula A-1 and / or the general formula A-2:

[0175]

[0176] in,

[0177] 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 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;

[0178] 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=;

[0179] 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-;

[0180] 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;

[0181] 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;

[0182] 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;

[0183] n A12 represents 1 or 2, where n A12 =2, ring may be the same or different; and

[0184] 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.

[0185] In some embodiments of the present invention, the weight percentage of at least one compound of general formula A-1 and / or general formula A-2 in the cholesteric liquid crystal composition is 0.1%-60% (including any numerical 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%, or a range between any two of the numerical values.

[0186] In some embodiments of the present invention, the compound of formula A-1 is selected from the group consisting of:

[0187]

[0188]

[0189]

[0190] as well as

[0191]

[0192] in,

[0193] R v and R w Each independently represents -CH2- or -O-;

[0194] L A11 , L A12 , LA11 ',L A12 ',L A14 , L A15 and L A16 Each independently represents -H or -F;

[0195] L A13 and L A13 'Each independently represents -H or -CH3;

[0196] X A1 represents -F, -CF3 or -OCF3; and

[0197] v and w each independently represent 0 or 1.

[0198] In some embodiments of the present invention, the weight percentage of the compound of general formula A-1 in the cholesteric liquid crystal composition is 0.1%-30% (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%, 22%, 24%, 25%, 26%, 28%, 30%, or a range between any two values.

[0199] In some embodiments of the present invention, the cholesteric liquid crystal composition of the present invention comprises at least one compound of the general formula A-1-12 and / or at least one compound of the general formula A-1-23.

[0200] In some embodiments of the present invention, the compound of formula A-2 is selected from the group consisting of:

[0201]

[0202]

[0203]

[0204]

[0205] as well as

[0206]

[0207] in,

[0208] L A21 , L A22 , L A23 , L A24 and L A25 each independently represents -H or -F; and

[0209] X A2 It represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

[0210] In some embodiments of the present invention, the weight percentage of the compound of general formula A-2 in the cholesteric liquid crystal composition 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.

[0211] In addition to the above-mentioned compounds, the cholesteric 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.

[0212] In addition, the antioxidants, light stabilizers and other additives used in the cholesteric liquid crystal composition of the present invention are preferably the following:

[0213]

[0214]

[0215]

[0216] Here, n represents a positive integer from 1 to 12.

[0217] Preferably, the antioxidant is selected from the light stabilizers shown below:

[0218]

[0219] In some embodiments of the present invention, the weight percentage of the additive in the cholesteric liquid crystal composition is 0%-5%; preferably, the weight percentage of the additive in the cholesteric liquid crystal composition is 0.01%-1%.

[0220] 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 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.

[0221] In another aspect, the present invention provides application of the above liquid crystal display device in color display.

[0222] Beneficial effects: Compared with the prior art, the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color is brighter and has higher purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0223] For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0224] Figure 1 A single-layer cholesteric liquid crystal display device according to the embodiment is shown.

[0225] Figure 2 A double-layer cholesteric liquid crystal display device according to the embodiment is shown.

[0226] Figure 3 A schematic diagram of a vertically aligned antiparallel alignment according to an embodiment is shown.

[0227] Figure 4 A schematic diagram of a vertically aligned parallel alignment according to an embodiment is shown.

[0228] Figure 5 A schematic diagram of a parallel arrangement and orthogonal alignment according to an embodiment is shown.

[0229] Figure 6 A cholesteric liquid crystal display device having no alignment layer according to the embodiment is shown. DETAILED DESCRIPTION

[0230] 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.

[0231] For ease of expression, in the following examples, the group structure of each compound is represented by the code listed in Table 1:

[0232] Table 1 Group structure codes of compounds

[0233]

[0234]

[0235] Take the following compound as an example:

[0236]

[0237] 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 a fluorine substituent.

[0238] The abbreviated codes for the test items in the following embodiments are as follows:

[0239] Cp 1 Clearing point of liquid crystal composition A (nematic-isotropic phase transition temperature, °C)

[0240] Δn optical anisotropy (589nm, 25℃)

[0241] n o Refractive index of ordinary light (589nm, 25℃)

[0242] n e Refractive index of extraordinary light (589nm, 25℃)

[0243] Δε Dielectric anisotropy (1KHz, 25℃)

[0244] λmax The wavelength corresponding to the highest reflectivity in the reflection spectrum (nm, 25℃)

[0245] Δλ Half peak width (nm, 25℃)

[0246] PTA pretilt angle (°, 25°C)

[0247] in,

[0248] Cp 1 : Obtained by melting point test.

[0249] Δn: Δn=n e -n0, measured using an Abbe refractometer under a sodium lamp (589nm) at 25°C.

[0250] 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.

[0251] λmax: Cholesteric liquid crystal is poured into a test box (box thickness: 4μm), and the reflection spectrum of the P state at the normal viewing angle is tested using a DMS 505 photoelectric comprehensive tester. The wavelength corresponding to the highest reflectivity in the reflection spectrum is λmax.

[0252] △λ: Cholesteric liquid crystal is poured into a test box (box thickness: 4μm), and the reflection spectrum of the P state at the positive viewing angle is tested using a DMS 505 photoelectric comprehensive tester. The peak width corresponding to half the peak height of the reflection spectrum is △λ.

[0253] PTA: The cholesteric liquid crystal composition was poured into a test cell (cell thickness: 4 μm), and the pretilt angle value generated by the cholesteric liquid crystal composition was measured using Shintech Optipro-micro.

[0254] 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.

[0255] 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.

[0256] LC1

[0257] 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.

[0258] Table 2 Formulation and performance parameter test results of liquid crystal composition LC1

[0259]

[0260] LC2

[0261] 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.

[0262] Table 3 Formulation and performance parameter test results of liquid crystal composition LC2

[0263]

[0264]

[0265] LC3

[0266] 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.

[0267] Table 4 Formulation and performance parameter test results of liquid crystal composition LC3

[0268]

[0269] LC4

[0270] 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.

[0271] Table 5 Formulation and performance parameter test results of liquid crystal composition LC4

[0272]

[0273] M1

[0274] A liquid crystal display device, the structural schematic diagram of which is as follows Figure 1 The liquid crystal display device comprises a first substrate, a first conductive layer, a first alignment layer, a first cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer and a second substrate, wherein the alignment directions of the first alignment layer and the second alignment layer are as follows: Figure 3 The homeotropic antiparallel alignment is shown.

[0275] M2

[0276] A liquid crystal display device, the structural schematic diagram of which is as follows Figure 1 The liquid crystal display device comprises a first substrate, a first conductive layer, a first alignment layer, a first cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer and a second substrate, wherein the alignment directions of the first alignment layer and the second alignment layer are as follows: Figure 4 Homeotropic parallel alignment shown.

[0277] M3

[0278] A liquid crystal display device, the structural schematic diagram of which is as follows Figure 1 The liquid crystal display device comprises a first substrate, a first conductive layer, a first alignment layer, a first cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer and a second substrate, wherein the alignment directions of the first alignment layer and the second alignment layer are as follows: Figure 5 The parallel arrangement shown is orthogonally aligned.

[0279] M4

[0280] A liquid crystal display device, the structural schematic diagram of which is as follows Figure 6 The liquid crystal display device includes a first substrate, a first conductive layer, a first cholesteric liquid crystal composition layer, a second conductive layer and a second substrate.

[0281] M5

[0282] A liquid crystal display device, the structural schematic diagram of which is as follows Figure 2The liquid crystal display device comprises a first substrate, a first conductive layer, a first alignment layer, a first cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer, a second substrate, a third conductive layer, a third alignment layer, a second cholesteric liquid crystal composition layer, a fourth alignment layer, a fourth conductive layer and a third substrate, wherein the alignment directions of the first alignment layer and the second alignment layer and the alignment directions of the third alignment layer and the fourth alignment layer are as follows Figure 3 The homeotropic antiparallel alignment is shown.

[0283] Comparative Examples 1-3 and Example 1

[0284] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 6, and filled between two substrates of a corresponding liquid crystal display device for performance testing.

[0285] Table 6

[0286]

[0287] From the comparison between Comparative Examples 1-3 and Example 1, it can be seen that the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color of the liquid crystal display device is brighter and has higher purity when displayed.

[0288] Comparative Examples 4-6 and Example 2

[0289] A cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 7, and filled between two substrates of a corresponding liquid crystal display device for performance testing.

[0290] Table 7

[0291]

[0292]

[0293] From the comparison between Comparative Examples 4-6 and Example 2, it can be seen that the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color of the liquid crystal display device is brighter and has higher purity when displayed.

[0294] Comparative Examples 7-9 and Example 3

[0295] 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 corresponding liquid crystal display device for performance testing.

[0296] Table 8

[0297]

[0298] From the comparison between Comparative Examples 7-9 and Example 3, it can be seen that the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color of the liquid crystal display device is brighter and has higher purity when displayed.

[0299] Comparative Examples 10-12 and Example 4

[0300] 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 corresponding liquid crystal display device for performance testing.

[0301] Table 9

[0302]

[0303] From the comparison between Comparative Examples 10-12 and Example 4, it can be seen that the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color of the liquid crystal display device is brighter and has higher purity when displayed.

[0304] Comparative Examples 13-15 and Example 5

[0305] 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 corresponding liquid crystal display device for performance testing.

[0306] Table 10

[0307]

[0308] From the comparison between Comparative Examples 13-15 and Example 5, it can be seen that the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, so that the reflected color of the liquid crystal display device is brighter and has higher purity when displayed.

[0309] Embodiment 6-9

[0310] 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 corresponding liquid crystal display device for performance testing.

[0311] Table 11

[0312]

[0313] When the chiral agent is preferably of formula R / S-2011 or formula R / S-5011, the liquid crystal display device of the present invention has a narrower half-peak width at a comparable λmax, so that the reflected color of the liquid crystal display device is brighter and has a higher purity.

[0314] In summary, the liquid crystal display device of the present invention has a narrower half-peak width under the condition of equivalent λmax, and the reflected color is brighter and has higher purity.

[0315] 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 liquid crystal display device, characterized in that: The liquid crystal display device comprises at least one display panel, which comprises, from top to bottom, a first substrate, a first conductive layer, a first alignment layer, a cholesteric liquid crystal composition layer, a second alignment layer, a second conductive layer, and a second substrate; wherein the first alignment layer and the second alignment layer are vertically aligned, and the rubbing direction is up and down anti-parallel rubbing.

2. The liquid crystal display device according to claim 1, characterized in that: The cholesteric liquid crystal composition layer includes a cholesteric liquid crystal composition, wherein the cholesteric liquid crystal composition includes at least one chiral agent selected from the group consisting of formula R / S-811, formula R / S-1011, formula R / S-2011, formula R / S-5011 and formula R / S-6N: as well as Wherein, * indicates chiral site.

3. The liquid crystal display device according to claim 2, characterized in that: The cholesteric liquid crystal composition further comprises at least one compound of formula I: 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-; 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 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; L T1 and L T2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 carbon atoms; L T3 represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms; and 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.

4. The liquid crystal display device according to claim 3, characterized in that: The cholesteric liquid crystal composition further comprises at least one compound of formula II: in, 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 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=; Z C1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; L C1 and L C2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 carbon atoms; L C3 represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms; 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.

5. The liquid crystal composition according to claim 4, 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=.

6. The liquid crystal display device according to claim 5, 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.

7. The liquid crystal display device according to claim 3, characterized in that: The cholesteric liquid crystal composition further comprises at least one compound of formula III: in, R S1 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 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=; Z S1 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O- or -OCF2-; L S1 and L S2 Each independently represents -H, halogen, a haloalkyl group or a haloalkoxy group containing 1 to 3 carbon atoms; L S3 represents -H, an alkyl group or an alkoxy group containing 1 to 3 carbon atoms; and 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.

8. The liquid crystal composition according to claim 3, characterized in that: The cholesteric liquid crystal composition 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, wherein At most one -H in may be replaced by halogen; Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -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.

9. The liquid crystal display device according to claim 3, characterized in that: The cholesteric liquid crystal composition 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.

10. Use of the liquid crystal display device according to any one of claims 1 to 9 in color display.

Images