Liquid crystal composition and liquid crystal display device thereof

Abstract

The present application provides a liquid crystal display device, the liquid crystal display device comprises at least one display panel, the display panel comprises from top to bottom, first substrate, first conductive layer, first alignment layer, cholesteric liquid crystal composition layer, second alignment layer, second conductive layer and second substrate, wherein, the first alignment layer and the second alignment layer are perpendicular alignment, and the rubbing direction is up-down anti-parallel rubbing.The liquid crystal display device has narrower half-peak width under the condition of equivalent λmax, so that the reflected color is more bright and pure.

Description

TECHNICAL FIELD

[0001] The present application relates to a liquid crystal composition, in particular to a cholesteric liquid crystal composition and a liquid crystal display device comprising the same. BACKGROUND

[0002] With the development of display technology, display devices with light weight, thin volume, energy saving and environmental protection have become mainstream, and bistable liquid crystal display devices have attracted much attention. Among them, cholesteric liquid crystal display devices (ChLCD) have high brightness, high contrast, power saving, high memory, wide viewing angle, no flicker and other advantages, and can maintain two different states of bright state and dark state under the condition of removing electric field, so it has become the development focus of current bistable display devices, and is widely used in electronic books, electronic tags, display panels, anti-peep screens and other electronic devices with low energy consumption requirements.

[0003] Cholesteric liquid crystal is a kind of liquid crystal molecule with Bragg reflection and bistable characteristics, which can reflect incident light with wavelength and optical rotation equivalent to its pitch. Under the drive of electric field, it can be switched to planar state (P state) or focal conic state (Fc state). P state and Fc state can also be maintained in the state of voltage off, so the bistable stability is also called memory. In cholesteric liquid crystal display, cholesteric liquid crystal reflects 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 it is in planar state, so the corresponding screen displays bright state; cholesteric liquid crystal scatters light and is absorbed by the backboard of the display when it is in focal conic state, so the corresponding screen displays dark state.

[0004] A cholesteric liquid crystal display device exhibits a specific selective reflection wavelength depending on a chiral pitch in a state where a cholesteric phase is perpendicular to a 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), and thus, in the case where the refractive index of the liquid crystal composition is fixed, a desired selective reflection wavelength is obtained by adjusting the concentration of a chiral compound and adjusting the chiral pitch. The half-peak width (Δλ) of the selectively reflected light and the product of the anisotropy of the refractive index (Δn = ne-no) of the liquid crystal and the chiral pitch are proportional to each other at this time, but a certain degree of wide half-peak width is required in order to achieve bright display, and thus a liquid crystal composition having a large Δn must be used. In the above case, the average refractive index of the liquid crystal composition also becomes large, and thus further addition of a chiral agent is required in order to shorten P for adjustment to a desired λ, but if the amount of the chiral compound is excessively increased, problems such as deterioration of the liquid crystal temperature range of the host liquid crystal and increase in viscosity occur. That is, for the design of a cholesteric liquid crystal, a chiral compound having a high liquid crystal twisting force for inducing a chiral pitch and a small influence on the host liquid crystal is required, and a host liquid crystal composition having excellent compatibility with such a compound and a high Δn is required. Furthermore, a sufficiently large dielectric anisotropy (Δε) for enabling low-voltage driving as a liquid crystal display element, and good storage properties in which precipitation does not occur even in a low-temperature environment are required.

[0005] The length of the chiral pitch of a cholesteric liquid crystal depends on the type or the added concentration of a chiral compound, and can be represented 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 by which the chiral compound twists the liquid crystal composition, and is referred to as helical twisting power (HTP).

[0006] In the conventional cholesteric liquid crystal, the planar state reflection spectrum Δλ is large, and the planar state reflectance is high, but the planar state reflection color saturation and the vividness are poor, and the reflected color is not sufficiently vivid or even achromatic in the visual sense, which greatly limits the application of the cholesteric liquid crystal to color display.

[0007] How to solve the above problems is a problem to be solved by those skilled in the art. SUMMARY

[0008] The purpose of the present application is to provide a liquid crystal display device having a narrower half-peak width in the case of a comparable λmax, thereby making the reflected color more vivid and pure.

[0009] Technical solution: In order to achieve the above-mentioned objectives, the present invention provides a liquid crystal display device, which includes at least one (e.g., two, three, four, etc.) display panel. 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. The first alignment layer and the second alignment layer are vertically aligned, and the friction direction is vertically antiparallel friction.

[0010] In some embodiments of the present invention, the liquid crystal display device of the present invention includes a first display panel and a second display panel, the first display panel and the second display panel sharing a second substrate. The first display panel, from top to bottom, sequentially includes 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. The second display panel, from top to bottom, sequentially includes 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. The first alignment layer and the second alignment layer are vertically aligned, and the friction direction is vertically antiparallel friction. The third alignment layer and the fourth alignment layer are vertically aligned, and the friction direction is vertically parallel friction or vertically antiparallel friction.

[0011] In some embodiments of the present invention, the third alignment layer and the fourth alignment layer are vertically aligned, and the friction direction is vertical antiparallel friction.

[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 a polyimide, a polymeric derivative having a light-degradable or ectopic polyamic acid, 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 made of glass or polymer. Preferably, the first substrate, the second substrate, and the third substrate are each independently made of 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 provided on the underside of the second or 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 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 this invention, the inventors selected the alignment direction and friction direction of the alignment layers arranged in parallel in the liquid crystal display device, so that the liquid crystal display device of this invention has a narrower half-width, thereby making the reflected colors more vivid and purer.

[0017] In this invention, the term "cholesterol phase liquid crystal composite layer" without the addition of "first" or "second" applies independently to "first cholesterol phase liquid crystal composite layer" or "second cholesterol phase liquid crystal composite 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 formulas R / S-811, R / S-1011, R / S-2011, R / S-5011, and R / S-6N:

[0019]

[0020] as well as

[0021]

[0022] In this context, * indicates a chiral site.

[0023] In some embodiments of the invention, the chiral agent constitutes 0.1% to 50% (inclusive of any value or subrange within this range) of the weight percentage of the cholesteric liquid crystal composition, 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%, or 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 these values.

[0024] In some embodiments of the invention, when the chiral agent is R / S-5011, it accounts for 1% to 10% (inclusive of any value or subrange within this range) of the weight of the cholesteric liquid crystal composition, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these values.

[0025] In some embodiments of the invention, when the chiral agent is R / S-811, it comprises 20%-30% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this range), for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or a range between any two of these values.

[0026] In some embodiments of the invention, when the chiral agent is R / S-2011, it comprises 20%-30% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this range), for example, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, or a range between any two of these values.

[0027] In some embodiments of the invention, when the chiral agent is R / S-6N, it accounts for 1% to 10% (inclusive of any value or subrange within this range) of the weight of the cholesteric liquid crystal composition, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these 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 general formula I:

[0030]

[0031] in,

[0032] R T1 and R T2 Each of the following can independently represent -H, a straight-chain alkyl group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) carbon atoms, or a branched alkyl group containing 3-12 (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 alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0033] ring and ring Each represents independently in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced 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 -CH= in one or more rings can be replaced by -N=.

[0034] Z T1 It 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 can independently represent -H, halogen, or haloalkyl or haloalkoxy containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms;

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

[0037] n T1 Represents 0, 1, or 2, when n T1 When = 2, ring They can be the same or different, Z T1 They can be the same or different.

[0038] In some embodiments of the present invention, the compounds of general formula I are selected from the group consisting of the following compounds:

[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 can independently represent -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; more 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 compounds of general formula I are selected from the group consisting of the following compounds:

[0049]

[0050]

[0051]

[0052] as well as

[0053]

[0054] in,

[0055] L T1 'and L T2 Each can be independently represented as -F, -Cl, -CF3, or -OCF3; and

[0056] L T4 '、L T5 'and L T6 Each can be represented independently as -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 compounds of general formula I are 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, and 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 1-6 carbon atoms; and

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

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

[0067] In some embodiments of the invention, the compound of general formula I constitutes 0.1%-70% (inclusive of any value or subrange within this range) of the cholesteric liquid crystal composition by weight, 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%, etc. 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 a range between any two of these values; preferably, the compound of general formula I accounts for 30%-60% of the weight percentage of the cholesteric phase liquid crystal composition.

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

[0069]

[0070] in,

[0071] R C1 The term "-H" indicates a straight-chain alkyl group containing 1-12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12) or a branched alkyl group containing 3-12 carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12). One or more -CH2- groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched 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 groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0072] ring express in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced 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 -CH= in one or more rings can be replaced by -N=.

[0073] Z C1 It 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 can independently represent -H, halogen, or haloalkyl or haloalkoxy containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms;

[0075] L C3 It represents -H, an alkyl or alkoxy group 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 When = 2 or 3, the ring They can be the same or different, Z C1 They 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 compounds of general formula II are selected from the group consisting of the following compounds:

[0079]

[0080]

[0081] as well as

[0082]

[0083] in,

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

[0085] L C1 and L C2 Each can be independently represented as -H, -F, -Cl, -CF3, or -OCF3;

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

[0087] ring express in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H atoms can be independently replaced by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1-3 carbon atoms, and -CH= in one or more rings can be replaced by -N=.

[0088] In some embodiments of the present invention, the compounds of general formula II are selected from the group consisting of the following compounds:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] as well as

[0098]

[0099] in,

[0100] L C1 'and L C2 Each can be independently represented as -F, -Cl, -CF3, or -OCF3; and

[0101] L C4 and L C5 Each can be independently represented as -H, -F, -Cl, -CF3, or -OCF3.

[0102] In some embodiments of the present invention, in order to obtain a narrower half-peak 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-peak width, the compound of general formula II is selected from the group consisting of compounds of general formula II-1-1, general formula II-2-14-1, general formula II-2-14-2, general formula II-2-14-3, general formula II-2-15-1, general formula II-2-15-2, general formula II-2-15-3, general formula II-2-15-4, general formula II-2-15-5, general formula II-3-2-1, and general formula II-3-3-1.

[0104]

[0105]

[0106] as well as

[0107]

[0108] in,

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

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

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

[0112] In some embodiments of the invention, the compound of general formula II constitutes 0.1%-80% (inclusive of any value or subrange within this range) of the cholesteric liquid crystal composition by weight, 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%, etc. 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 compound of general formula II accounts for 20%-70% of the weight percentage of the cholesteric phase liquid crystal composition.

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

[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 general formula III:

[0116]

[0117] in,

[0118] R S1This refers to straight-chain alkyl groups containing 1-12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12), and branched alkyl groups containing 3-12 carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12). One or more -CH2- groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched 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 groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0119] ring express in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced 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 -CH= in one or more rings can be replaced by -N=.

[0120] Z S1 It 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 can independently represent -H, halogen, or haloalkyl or haloalkoxy containing 1 to 3 (e.g., 1, 2, or 3) carbon atoms;

[0122] L S3 It represents -H, an alkyl or alkoxy group 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 When = 2 or 3, the ring They can be the same or different, Z S1 They 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 compounds of general formula III are selected from the group consisting of the following compounds:

[0126]

[0127] as well as

[0128]

[0129] in,

[0130] L S1 and L S2 Each can be independently represented as -H, -F, -Cl, -CF3, or -OCF3;

[0131] Z S2 and Z S1 Each can be independently represented as -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- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H atoms can be independently replaced 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 -CH= in one or more rings can be replaced by -N=.

[0133] In some embodiments of the present invention, the compounds of general formula III are selected from the group consisting of the following compounds:

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] as well as

[0140]

[0141] in,

[0142] L S1 'and L S2 Each can be independently represented as -F, -Cl, -CF3, or -OCF3; and

[0143] L S4 and L S5 Each can be independently represented as -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 general formula III-1-6.

[0145] In some embodiments of the invention, the compound of general formula III accounts for 0.1% to 20% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this 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 of these values.

[0146] In some embodiments of the present invention, halogens are each independently represented as -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 general formula M:

[0148]

[0149] in,

[0150] R M1 and R M2 Each of these terms independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12), or a branched alkyl group containing 3 to 12 carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12). One or more non-adjacent -CH2- in a straight-chain alkyl group containing 1-12 carbon atoms or a branched alkyl group containing 3-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-;

[0151] ring ring and ring Each represents independently in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds, wherein At most one -H in the halogen can be replaced by a halogen;

[0152] Z M1 and Z M2 Each can independently represent 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 when n M When = 2, ring They can be the same or different, Z M2 They can be the same or different.

[0154] In some embodiments of the present invention, the compounds of general formula M are selected from the group consisting of the following compounds:

[0155]

[0156]

[0157]

[0158]

[0159]

[0160] as well as

[0161]

[0162] Among them, R M1 and R M2 Each can independently represent a straight-chain alkyl group containing 1-12 carbon atoms, a branched alkyl group containing 3-12 carbon atoms, or one or more non-adjacent -CH2- groups. -CH2- 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 general formula M-1 is selected from the group consisting of the following compounds:

[0164]

[0165] in,

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

[0167] In some embodiments of the present invention, the compounds of general formula M-5 are selected from the group consisting of the following compounds:

[0168]

[0169] in,

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

[0171] In some embodiments of the invention, the compound of general formula M accounts for 0.1% to 30% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this 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 a range between any two of these 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; more 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 One of them is a straight-chain alkenyl group containing 2-5 carbon atoms, while the other is a straight-chain alkyl group containing 1-5 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 general formula A-1 and / or general formula A-2:

[0175]

[0176] in,

[0177] R A1 and R A2 Each of these terms independently represents a straight-chain alkyl group containing 1 to 12 carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12), or a branched alkyl group containing 3 to 12 carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12). One or more -CH2- groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched 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 groups of a straight-chain alkyl group containing 1-12 carbon atoms or a branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl;

[0178] ring ring ring and ring Each represents independently in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced by -F, -Cl or -CN, and -CH= in one or more rings can be replaced by -N=;

[0179] Z A11 Z A21 and Z A22 Each can independently represent 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 can independently represent -H, an alkyl group containing 1-3 carbon atoms, or a halogen;

[0181] X A1 and X A2 Each can independently represent a halogen, a haloalkyl or haloalkoxy group containing 1-5 carbon atoms, or a haloalkenyl or haloalkenoxy group containing 2-5 carbon atoms.

[0182] n A11 Represents 0, 1, 2, or 3, when n A11 When = 2 or 3, the ring They can be the same or different, Z A11 They can be the same or different;

[0183] n A12 Represents 1 or 2, where when n A12 When = 2, ring They can be the same or different; and

[0184] n A2 Represents 0, 1, 2, or 3, where when n A2 When = 2 or 3, the ring They can be the same or different, Z A21 They can be the same or different.

[0185] In some embodiments of the invention, at least one compound of general formula A-1 and / or general formula A-2 constitutes 0.1% to 60% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this 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%, or a range between any two of these values.

[0186] In some embodiments of the present invention, the compounds of general formula A-1 are selected from the group consisting of the following compounds:

[0187]

[0188]

[0189]

[0190] as well as

[0191]

[0192] in,

[0193] R v and R w Each can be represented independently as -CH2- or -O-;

[0194] L A11 L A12 LA11 '、L A12 '、L A14 L A15 and L A16 Each can be represented independently as -H or -F;

[0195] L A13 and L A13 Each can be represented independently as -H or -CH3;

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

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

[0198] In some embodiments of the invention, the compound of general formula A-1 accounts for 0.1% to 30% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this 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 these values.

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

[0200] In some embodiments of the present invention, the compounds of general formula A-2 are selected from the group consisting of the following compounds:

[0201]

[0202]

[0203]

[0204]

[0205] as well as

[0206]

[0207] in,

[0208] L A21 L A22 L A23 L A24 and L A25 Each can be independently represented as -H or -F; and

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

[0210] In some embodiments of the invention, the compound of general formula A-2 constitutes 0.1% to 50% by weight of the cholesteric liquid crystal composition (inclusive of any value or subrange within this 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 a range between any two of these values.

[0211] In addition to the compounds mentioned above, the cholesteric liquid crystal compositions of the present invention may also contain conventional antioxidants, ultraviolet absorbers, infrared absorbers, photoinitiators, polymerizable monomers, or light stabilizers.

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

[0213]

[0214]

[0215]

[0216] Where 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 additive accounts for 0%-5% of the weight percentage of the cholesteric liquid crystal composition; preferably, the additive accounts for 0.01%-1% of the weight percentage of the cholesteric liquid crystal composition.

[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 (inclusive of any value or subrange within this 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 the application of the above-described 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-width at a comparable λmax, thereby making the reflected colors more vivid and purer. Attached Figure Description

[0223] To more fully understand the nature and advantages of the invention, reference should be made to the following detailed description in relation to the accompanying drawings, wherein:

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

[0225] Figure 2 A bilayer cholesteric liquid crystal display device according to an embodiment is shown.

[0226] Figure 3 A schematic diagram of the vertically aligned antiparallel alignment according to the implementation scheme is shown.

[0227] Figure 4 A schematic diagram of the vertically aligned parallel orientation according to the implementation scheme is shown.

[0228] Figure 5 A schematic diagram of parallel orthogonal alignment according to the implementation scheme is shown.

[0229] Figure 6 A cholesteric liquid crystal display device without an alignment layer is shown according to an embodiment. Detailed Implementation

[0230] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0231] For ease of explanation, the group structures of each compound in the following embodiments are represented by the codes listed in Table 1:

[0232] Table 1. Group structure codes of compounds

[0233]

[0234]

[0235] Take the following compound with the following structural formula 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 alkyl group at the left end. For example, if n is "3", it means that the alkyl group is -C3H7. In the code, C represents 1,4-cyclohexylene, G represents 2-fluoro-1,4-phenyleneene, and F represents fluorine substituent.

[0238] The abbreviated codes for the test items in the following examples 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 (589 nm, 25 °C)

[0242] n e Refractive index of unusual light (589 nm, 25 °C)

[0243] Δε dielectric anisotropy (1kHz, 25℃)

[0244] λmax is the wavelength (nm, 25℃) corresponding to the highest reflectance in the reflection spectrum.

[0245] Δλ (half-width at half maximum, nm, 25℃)

[0246] PTA pretilt angle (°, 25℃)

[0247] in,

[0248] Cp 1 : Obtained by testing with a melting point apparatus.

[0249] Δn: Δn = n e -n0 was obtained by testing with an Abbe refractometer under a sodium lamp (589nm) light source at 25°C.

[0250] Δε: Δε=ε || -ε ⊥ , where ε || ε is the dielectric constant parallel to the molecular axis. ⊥ The dielectric constant is perpendicular to the molecular axis; test conditions: 25℃, 1KHz, VA type test box with a thickness of 6μm.

[0251] λmax: Cholesteric liquid crystal is filled into a test cell (cell thickness: 4μm), and the reflection spectrum of the P-state at the positive viewing angle is measured using a DMS 505 photoelectric comprehensive tester. The wavelength corresponding to the highest reflectance in the reflection spectrum is λmax.

[0252] △λ: The cholesteric liquid crystal is filled into the test cell (cell thickness: 4μm), and the reflection spectrum of the P-state at the positive viewing angle is measured 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: 4μm), and the pretilt angle value generated by the cholesteric liquid crystal composition was tested using a Shintech Optipro-micro.

[0254] All components used in the following embodiments can be synthesized using known methods or obtained commercially. These synthesis techniques are conventional, and the resulting liquid crystal compounds have been tested and found to meet electronic compound standards.

[0255] Liquid crystal compositions were prepared according to the proportions of the liquid crystal compounds specified in the following examples. The liquid crystal compositions were prepared according to conventional methods in the art, such as mixing in proportion by heating, ultrasound, suspension, etc.

[0256] LC1

[0257] Liquid crystal composition LC1 was prepared according to the compounds listed in Table 2 and their weight percentages, and was filled between the two substrates of the liquid crystal display for performance testing.

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

[0259]

[0260] LC2

[0261] Liquid crystal composition LC2 was prepared according to the compounds listed in Table 3 and their weight percentages, and was filled between the two substrates of the 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 was filled between the two substrates of the 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 listed in Table 5 and their weight percentages, and was filled between the two substrates of the 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 schematic diagram of a liquid crystal display device is shown below. Figure 1 The liquid crystal display device includes 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 vertically aligned antiparallel alignment is shown.

[0275] M2

[0276] A schematic diagram of a liquid crystal display device is shown below. Figure 1 The liquid crystal display device includes 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 The vertically aligned parallel orientation is shown.

[0277] M3

[0278] A schematic diagram of a liquid crystal display device is shown below. Figure 1 The liquid crystal display device includes 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 is orthogonally aligned as shown.

[0279] M4

[0280] A schematic diagram of a liquid crystal display device is shown below. 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 schematic diagram of a liquid crystal display device is shown below. Figure 2The liquid crystal display device includes 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 and second alignment layers and the alignment directions of the third and fourth alignment layers are as follows: Figure 3 The vertically aligned antiparallel alignment is shown.

[0283] Comparative Examples 1-3 and Example 1

[0284] Cholesteric liquid crystal compositions were prepared according to the components and their weight percentages listed in Table 6, and then filled between the two substrates of the corresponding liquid crystal display device for performance testing.

[0285] Table 6

[0286]

[0287] As can be seen from the comparison between Comparative Examples 1-3 and Example 1, the liquid crystal display device of the present invention has a narrower half-width at a relatively large λmax, which makes the reflected colors more vivid and purer when the liquid crystal display device is displayed.

[0288] Comparative Examples 4-6 and Example 2

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

[0290] Table 7

[0291]

[0292]

[0293] As can be seen from the comparison between Comparative Examples 4-6 and Example 2, the liquid crystal display device of the present invention has a narrower half-width at a relatively large λmax, which makes the reflected colors more vivid and purer when the liquid crystal display device is displayed.

[0294] Comparative Examples 7-9 and Example 3

[0295] The cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 8, and then filled between the two substrates of the corresponding liquid crystal display device for performance testing.

[0296] Table 8

[0297]

[0298] As can be seen from the comparison between Comparative Examples 7-9 and Example 3, the liquid crystal display device of the present invention has a narrower half-width at a comparable λmax, which makes the reflected colors more vivid and purer when the liquid crystal display device is displayed.

[0299] Comparative Examples 10-12 and Example 4

[0300] The cholesteric liquid crystal composition was prepared according to the components and their weight percentages listed in Table 9, and then filled between the two substrates of the corresponding liquid crystal display device for performance testing.

[0301] Table 9

[0302]

[0303] As can be seen from the comparison between Comparative Examples 10-12 and Example 4, the liquid crystal display device of the present invention has a narrower half-width at a relatively large λmax, which makes the reflected colors more vivid and purer when the liquid crystal display device is displayed.

[0304] Comparative Examples 13-15 and Example 5

[0305] Cholesteric liquid crystal compositions were prepared according to the components and their weight percentages listed in Table 10, and then filled between the two substrates of the corresponding liquid crystal display device for performance testing.

[0306] Table 10

[0307]

[0308] As can be seen from the comparison between Comparative Examples 13-15 and Example 5, the liquid crystal display device of the present invention has a narrower half-width at a relatively large λmax, which makes the reflected colors more vivid and purer when the liquid crystal display device is displayed.

[0309] Examples 6-9

[0310] Cholesteric liquid crystal compositions were prepared according to the components and their weight percentages listed in Table 11, and then filled between the two substrates of the 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-width at a given λmax, resulting in more vivid and purer reflected colors when the liquid crystal display device is displayed.

[0314] In summary, the liquid crystal display device of the present invention has a narrower half-width and more vivid and pure reflected colors under the same λmax.

[0315] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A liquid crystal display device, characterized in that, The liquid crystal display device includes at least one display panel, which, from top to bottom, comprises 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 friction direction is antiparallel friction; wherein the cholesteric liquid crystal composition layer comprises a cholesteric liquid crystal composition, and the cholesteric liquid crystal composition 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. Where * indicates a chiral site; The cholesteric liquid crystal composition further comprises at least one compound of general formula I: in, R T1 and R T2 Each can be independently represented as -H, a straight-chain alkyl group containing 1-12 carbon atoms, or a branched alkyl group containing 3-12 carbon atoms. , or One or more of the straight-chain alkyl group containing 1-12 carbon atoms or the branched alkyl group containing 3-12 carbon atoms, or two or more of the -CH2- groups, can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-. ring and ring Each represents independently or ,in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced by -F, -Cl, or a halo- or non-halogenated alkyl or alkoxy group containing 1-3 carbon atoms; one or more -CH= in the ring can be replaced by -N=. Z T1 It 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 can be independently represented by -H, halogen, or haloalkyl or haloalkoxy containing 1-3 carbon atoms; L T3 It represents -H, an alkyl or alkoxy group containing 1-3 carbon atoms; and n T1 Represents 0, 1, or 2, when n T1 When =2, the ring They can be the same or different, Z T1 They can be the same or different.

2. The liquid crystal display device according to claim 1, characterized in that, The cholesteric liquid crystal composition further comprises at least one compound of general formula II: in, R C1 Represents -H, straight-chain alkyl groups containing 1-12 carbon atoms, and branched alkyl groups containing 3-12 carbon atoms. , or One or more of the -CH2- groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched 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 of the -H groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl. ring express or ,in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced by -F, -Cl, or a halo- or non-halogenated alkyl or alkoxy group containing 1-3 carbon atoms; one or more -CH= in the ring can be replaced by -N=. Z C1 It 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 can be independently represented by -H, halogen, or haloalkyl or haloalkoxy containing 1-3 carbon atoms; L C3 It represents -H, an alkyl or alkoxy group containing 1-3 carbon atoms; and n C1 Represents 0, 1, 2, or 3, when n C1 When =2 or 3, the ring They can be the same or different, Z C1 They can be the same or different.

3. The liquid crystal display device according to claim 2, characterized in that, The compounds of general formula I are selected from the group consisting of the following compounds: The compounds of general formula II are selected from the group consisting of the following compounds: in, Z T1 '、Z C1 'and Z C2 Each can be independently represented as -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 can be independently represented as -H, -F, -Cl, -CF3, or -OCF3; L T3 and L C3 Each can independently represent -H, -CH3, -OCH3, -CH2CH3, or -OCH2CH3; and ring express or ,in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H atoms can be independently replaced by -F, -Cl, or a halogenated or unhalogenated alkyl or alkoxy group containing 1-3 carbon atoms, and -CH= in one or more rings can be replaced by -N=.

4. The liquid crystal display device according to claim 2, characterized in that, The compounds of general formula I are selected from the group consisting of the following compounds: The compounds of general formula II are selected from the group consisting of the following compounds: in, L T1 '、L T2 '、L C1 'and L C2 Each can be independently represented as -F, -Cl, -CF3, or -OCF3; L T4 '、L T5 'and L T6 Each can be independently represented as -F, -Cl, -CH3, or -OCH3; and L C4 and L C5 Each can be independently represented as -H, -F, -Cl, -CF3, or -OCF3.

5. The liquid crystal display device according to claim 1, characterized in that, The cholesteric liquid crystal composition further comprises at least one compound of general formula III: in, R S1 This refers to straight-chain alkyl groups containing 1-12 carbon atoms, and branched alkyl groups containing 3-12 carbon atoms. , or One or more of the -CH2- groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched 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 of the -H groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl. ring express or ,in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. One or more -H can be independently replaced by -F, -Cl, or a halo- or non-halogenated alkyl or alkoxy group containing 1-3 carbon atoms; one or more -CH= in the ring can be replaced by -N=. Z S1 It 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 can be independently represented by -H, halogen, or haloalkyl or haloalkoxy containing 1-3 carbon atoms; L S3 It represents -H, an alkyl or alkoxy group containing 1-3 carbon atoms; and n S1 Represents 0, 1, 2, or 3, when n S1 When =2 or 3, the ring They can be the same or different, Z S1 They can be the same or different.

6. The liquid crystal display device according to claim 1, characterized in that, The cholesteric liquid crystal composition further comprises at least one compound of general formula M: in, R M1 and R M2 Each can be independently represented as a straight-chain alkyl group containing 1-12 carbon atoms, or a branched alkyl group containing 3-12 carbon atoms. , or One or more of the straight-chain alkyl group containing 1-12 carbon atoms or the branched alkyl group containing 3-12 carbon atoms, or two or more of the -CH2- groups, can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-. ring ,ring and ring Each represents independently or ,in One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds, wherein At most one -H in the halogen can be replaced by a halogen; Z M1 and Z M2 Each can independently represent a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2-, or -(CH2)4-; and n M Represents 0, 1, or 2, where when n M When =2, the ring They can be the same or different, Z M2 They can be the same or different.

7. The liquid crystal display device according to claim 1, characterized in that, The cholesteric liquid crystal composition further comprises at least one compound of general formula A-1 and / or general formula A-2: in, R A1 and R A2 Each can be independently represented as a straight-chain alkyl group containing 1-12 carbon atoms, or a branched alkyl group containing 3-12 carbon atoms. , or One or more of the -CH2- groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched 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 of the -H groups in the straight-chain alkyl group containing 1-12 carbon atoms or the branched alkyl group containing 3-12 carbon atoms may be independently replaced by -F or -Cl. ring ,ring ,ring and ring Each represents independently , , or ,in , and One or more -CH2- bonds can be replaced by -O- bonds, and single bonds in one or at most two rings can be replaced by double bonds. and One or more -H can be independently replaced by -F, -Cl or -CN, and -CH= in one or more rings can be replaced by -N=; Z A11 Z A21 and Z A22 Each can independently represent 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 can independently represent -H, an alkyl group containing 1-3 carbon atoms, or a halogen; X A1 and X A2 Each can independently represent a halogen, a haloalkyl or haloalkoxy group containing 1-5 carbon atoms, or a haloalkenyl or haloalkenoxy group containing 2-5 carbon atoms. n A11 Represents 0, 1, 2, or 3, when n A11 When =2 or 3, the ring They can be the same or different, Z A11 They can be the same or different; n A12 Represents 1 or 2, where when n A12 When =2, the ring They can be the same or different; and n A2 Represents 0, 1, 2, or 3, where when n A2 When =2 or 3, the ring They can be the same or different, Z A21 They can be the same or different.

8. The application of the liquid crystal display device according to any one of claims 1-7 in color display.

Images