Liquid crystal composition and liquid crystal high-frequency phase modulation device thereof

Abstract

This invention provides a liquid crystal composition and a liquid crystal display device comprising the same. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, and at least one compound of general formula M. The liquid crystal composition provided by this invention enables the liquid crystal composition comprising the same to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy.

Description

Technical Field

[0001] This invention belongs to the field of liquid crystal material technology, specifically relating to a liquid crystal composition and a liquid crystal high-frequency phase modulation device containing the same. Background Technology

[0002] With the rapid development of modern communication technology, frequency congestion has become increasingly prominent. Solving this problem requires communication devices to have higher frequency tunability, wider bandwidth, and greater versatility. Existing ferroelectric microwave devices made of metals are no longer sufficient to meet the needs of modern communication development due to their large size, small capacity, slow tuning speed, complex manufacturing process, and high cost. In the past two decades, research has focused on low-voltage, fast-tuning, wide-bandwidth, miniaturized, and portable microwave communication devices to overcome these shortcomings and promote the upgrading of communication technology; this is also a common pursuit of communication terminal platforms in military, vehicle-mounted, shipborne, airborne, and aviation applications.

[0003] Those skilled in the art will know that liquid crystals with tunable phase in the K-band (4–40 GHz) under microwave conditions must meet the performance requirement of microwave phase tunability. Under the action of an external electric field E, the molecular alignment direction continuously rotates. The effective unusual refractive index neff(y) and dielectric constant (εr) of each liquid crystal molecule are changed with the applied voltage, where the dielectric constant is proportional to the square of the refractive index. The wave frequency signal propagates along the direction of the applied bias electric field, thereby achieving continuous tunability of the microwave phase.

[0004] Research by Merck in Germany shows that various liquid crystal materials with optical anisotropy (i.e., birefringence) greater than 0.3 have been developed to date. However, existing technologies using K15 or E7 have Δn values ​​below 0.2, very small Δεr values ​​at high frequencies, high dielectric loss, and problems such as excessively thick LC cells (d = 254 μm) and response times exceeding 350 ms. Merck's GT3-23001 liquid crystal has a Δn value of around 0.3, a Δεr reaching 0.8 at high frequencies, significantly reduced dielectric loss, and increased phase shift. In recent years, Merck has reported high Δn value mixed liquid crystal materials based on isothiocyanate-polycyclic aromatic acetylene groups, with Δn values ​​reaching around 0.35–0.38, which improves the dielectric properties of microwave devices, but dielectric loss remains relatively high. In 2018, Kowerdziej R. et al. reported the temperature-dependent optical tunability of fluorinated diphenylacetylene isothiocyanate-based liquid crystal assemblies in the 6 GHz band. They found that the microwave phase tunability (τ) and dielectric properties of these liquid crystals did not change significantly with temperature, indicating that the isothiocyanate and acetylene-based structural units are relatively stable to microwaves. Recently, Lapanik V. et al., building on Kowerdziej R.'s work, used isothiocyanate-polyaromatic ring mixed liquid crystal materials, which reduced dielectric loss and increased microwave phase shift, but the melting point of their liquid crystal materials was still above 0°C. To date, liquid crystals that can withstand extreme low temperatures, have a wide operating temperature range, low dielectric loss at the microwave end, high tunability, and excellent performance in all aspects remain extremely rare. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a liquid crystal composition that, while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, can effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies. The present invention also aims to provide a liquid crystal display device comprising the above-described liquid crystal composition.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a liquid crystal composition comprising at least one (e.g., two, three, or four) compounds of general formula I, at least one (e.g., two, three, or four) compounds of general formula II, and at least one (e.g., two, three, or four) compounds of general formula M:

[0008]

[0009] as well as

[0010]

[0011] Wherein, R1, R2, and R3 independently represent straight-chain or branched alkyl groups containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms, straight-chain or branched alkoxy groups containing 1-12 carbon atoms, and straight-chain or branched alkenyl groups containing 2-12 carbon atoms. One or more non-adjacent -CH2- in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -O-, -CO-, -CO-O- or -O-CO-;

[0012] R M1 and R M2 Each of these terms independently represents a straight-chain or branched alkyl group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms, a straight-chain or branched alkoxy group containing 1-12 carbon atoms, or a straight-chain or branched alkenyl group containing 2-12 carbon atoms. One or more non-adjacent -CH2- groups of straight-chain or branched alkyl groups containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms may be independently replaced by -CH=CH-, -O-, -CO-, -CO-O-, or -O-CO-.

[0013] ring ring ring ring and ring Whether they are the same or different, they are expressed independently. in One or more -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds;

[0014] ring and ring Whether they are the same or different, they are expressed independently. in One or more -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds. One or more -H can be replaced by -F or -Cl;

[0015] X1~X 10 The same or different, each independently representing -H, halogen, alkyl containing 1-3 (e.g. 1, 2, 3) carbon atoms, alkoxy containing 1-3 (e.g. 1, 2, 3) carbon atoms;

[0016] Z1 and Z2 independently represent single bonds, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-;

[0017] Z M1 It represents a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-;

[0018] n represents 0, 1, 2, and m represents 1, 2. When n = 2, the compound of general formula I contains two rings. These two rings They can have the same structure or different structures. For example, one can be... And the other is Where X1 or X2 are the same or different;

[0019] When m = 2, compounds of general formula I contain two rings. These two rings They can have the same structure or different structures. For example, one can be... And the other is Where X1 or X2 are the same or different, when m = 2, there are two Z1 in the compound of general formula I. Z1 can have the same structure or different structures. For example, one can be -C≡C- and the other can be -CH2CH2-.

[0020] p represents 0 or 1, q represents 0 or 1;

[0021] n M Represents 0, 1, 2, or 3, when n M When = 2, compounds of general formula M contain two rings. These two rings They can have the same structure or different structures. For example, one can be... And the other is When n M When the ratio is 3, compounds of general formula M contain three rings. These three rings They can have the same structure or different structures. For example, one can be... The other two are

[0022] When n M When = 2, there are two Z in compounds of general formula M. M1 Two Zs M1 They can be the same or different; for example, one can be -CO-O- and the other can be -CH2CH2-; when n M When the number of Z atoms is 3, there are three Z atoms in compounds of general formula M. M1 Three Zs M1 They can be the same or different; for example, one can be -CO-O- while the other two are -CH2CH2-; when the same description is used below, they have the same meaning.

[0023] In this invention, Z in compounds of general formula M M1 Not -C≡C-.

[0024] In this invention, the group containing 1-12 carbon atoms can be a group containing 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms.

[0025] In this invention, short straight lines on one or both sides of a group structure represent an access bond, not a methyl group, for example... The short straight line on the left, The short straight lines on both sides represent the connecting bonds that connect to the main structure of the compound.

[0026] In this invention, the halogens include halogen elements such as fluorine, chlorine, bromine, or iodine; the same descriptions used below have the same meaning.

[0027] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0028] In some embodiments of the present invention, the compound of general formula I is selected from the group consisting of the following compounds:

[0029]

[0030]

[0031] Wherein, R1 has the same defined range as the compounds of general formula I described above;

[0032] X1 to X4 may be the same or different, and each independently represents -H, halogen, alkyl group containing 1-3 carbon atoms, or alkoxy group containing 1-3 carbon atoms.

[0033] In some embodiments of the invention, R1 represents an alkyl or alkoxy group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms. R1 is further preferably an alkyl or alkoxy group containing 2-7 (e.g., 2, 3, 4, 5, 6, 7) carbon atoms. R1 is further preferably an alkyl group containing 2 carbon atoms, an alkyl group containing 3 carbon atoms, an alkyl group containing 5 carbon atoms, an alkyl group containing 7 carbon atoms, an alkoxy group containing 5 carbon atoms, or an alkoxy group containing 7 carbon atoms.

[0034] In some embodiments of the present invention, X1 to X4 may be the same or different, and each independently represents -H, -F, an alkyl group containing 1-3 carbon atoms, or an alkoxy group containing 1-3 carbon atoms. Preferably, X1 to X4 further independently represent -H or -F.

[0035] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I comprises at least one (e.g., one, two, three, four, or five) compound selected from the group consisting of compounds of general formula I-1, general formula I-2, general formula I-3, general formula I-5, and general formula I-6. In some embodiments of the present invention, the compound of general formula I is selected from the group consisting of the following compounds:

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042] as well as

[0043]

[0044] R1 has the same defined range as the compounds of general formula I described above.

[0045] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I comprises at least one (e.g., one, two, three, four, or five) compound selected from the group consisting of compounds of general formula I-1-2, general formula I-1-3, general formula I-2-3, general formula I-3-3, general formula I-3-6, general formula I-5-2, general formula I-5-3, general formula I-6-3, general formula I-6-6, and general formula I-6-9.

[0046] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula I so that the liquid crystal composition containing it can effectively improve low-temperature miscibility, reduce the dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy and absolute values ​​of dielectric anisotropy.

[0047] In some embodiments of the present invention, the compound of general formula I accounts for 0.1% to 95% (inclusive of any value or subrange within this range) of the weight percentage of the liquid crystal composition, for example, 0.1%, 0.5%, 1%, 2%, 3%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 13%, 14%, 16%, 17%, 19%, 20%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 30%, 31%, 33%, 35%, 37%, 38%, 40%, 42%, 44%, 45%, 4 The percentages are 6%, 47%, 49%, 50%, 52%, 54%, 56%, 58%, 60%, 65%, 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%, or any two of these values. Preferably, the compound of general formula I accounts for 50%-95% of the weight percentage of the liquid crystal composition.

[0048] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound selected from the group consisting of compounds of general formula I-1, general formula I-2, general formula I-3, general formula I-5, and general formula I-6 accounts for 50%-95% (inclusive of any value or subrange within this range) of the weight percentage of the liquid crystal composition, for example, 50%, 52%, 54%, 56%, 58%, 60%, 65%, 68%, 69%, 70 ... The percentage by weight of the compound is 1%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, or any two of these values; preferably, the compound selected from the group consisting of compounds of general formula I-1, general formula I-2, general formula I-3, general formula I-4, general formula I-5, and general formula I-6 accounts for 69%-91% of the liquid crystal composition.

[0049] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I-1 accounts for 20%-50% of the weight percentage of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 20%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 30%, 31%, 33%, 35%, 37%, 38%, 40%, 42%, 44%, 45%, 46%, 47%, 49%, 50%, or a range between any two of these values; preferably, the compound of general formula I-1 accounts for 22%-40% of the weight percentage of the liquid crystal composition.

[0050] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I-2 accounts for 1%-10% of the weight percentage of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these values. Preferably, the compound of general formula I-2 accounts for 2%-5% of the weight percentage of the liquid crystal composition.

[0051] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I-3 accounts for 1%-15% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or a range between any two of these values. Preferably, the compound of general formula I-3 accounts for 5%-10% of the weight of the liquid crystal composition.

[0052] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I-5 accounts for 1%-10% of the weight percentage of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these values. Preferably, the compound of general formula I-5 accounts for 2%-5% of the weight percentage of the liquid crystal composition.

[0053] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula I-6 accounts for 10%-40% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 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%, or a range between any two of these values. Preferably, the compound of general formula I-6 accounts for 30%-33% of the weight of the liquid crystal composition.

[0054] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase tunability of the liquid crystal at high frequencies, compounds of general formula I-1-2, general formula I-1-3, general formula I-2-3, general formula I-3-3, general formula I-3-6, general formula I-5-2, general formula I-5-3, general formula I-6-3, and general formula I-6-6 are selected. The compounds of the group consisting of compounds of general formulas I-6-9 constitute 69%-91% by weight of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, or a range between any two of these values.

[0055] In some embodiments of the present invention, the compound of general formula II is selected from the group consisting of the following compounds:

[0056]

[0057]

[0058] as well as

[0059]

[0060] R2 and R3 have the same limiting range as those in the compounds of general formula II described above.

[0061] In some embodiments of the invention, R2 represents a straight-chain alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, more preferably a straight-chain alkyl group containing 3 or 4 carbon atoms.

[0062] In some embodiments of the invention, R3 represents a straight-chain alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms, more preferably a straight-chain alkyl group containing 2-5 (e.g., 2, 3, 4 or 5) carbon atoms.

[0063] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of liquid crystal at high frequencies, and increase tunability of liquid crystal at high frequencies, the compound of general formula II preferably contains at least one (e.g., one, two, three, four or five) compound selected from the group consisting of compounds of general formula II-6, II-7 and II-9.

[0064] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula II so that the liquid crystal composition containing it can effectively improve low-temperature miscibility, reduce the dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy and absolute values ​​of dielectric anisotropy.

[0065] In some embodiments of the invention, the compound of general formula II constitutes 0.1% to 50% by weight of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%. The percentages are 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 any two of these values. Preferably, the compound of formula II accounts for 1% to 30% of the weight percentage of the liquid crystal composition.

[0066] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compounds selected from the group consisting of compounds of general formula II-6, general formula II-7, and general formula II-9 account for 1%-25% (inclusive of any value or sub-range within this range) of the liquid crystal composition, for example, 1%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or a range between any two of these values. Preferably, the compounds selected from the group consisting of compounds of general formula II-6, general formula II-7, and general formula II-9 account for 2%-25% of the weight of the liquid crystal composition.

[0067] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula II-6 accounts for 2%-20% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range between any two of these values. Preferably, the compound of general formula II-6 accounts for 5%-16% of the weight of the liquid crystal composition.

[0068] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula II-7 accounts for 2%-20% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range between any two of these values. Preferably, the compound of general formula II-7 accounts for 5%-17% of the weight of the liquid crystal composition.

[0069] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula II-9 accounts for 2%-25% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or a range between any two of these values. Preferably, the compound of general formula II-9 accounts for 2%-20% of the weight percentage of the liquid crystal composition.

[0070] In some embodiments of the present invention, the compound of general formula M is selected from the group consisting of the following compounds:

[0071]

[0072]

[0073] as well as

[0074]

[0075] Among them, R M1 and R M2 It has the same limiting range as compounds of the above general formula M.

[0076] In some embodiments of the present invention, R M1 This indicates a straight-chain alkyl group containing 1-8 (e.g., 1, 2, 3, 4, 5, 6, 7, or 8) carbon atoms; more preferably, a straight-chain alkyl group containing 2-5 (e.g., 2, 3, 4, or 5) carbon atoms; R M2 It refers to a straight-chain alkyl, straight-chain alkoxy or a straight-chain alkenyl containing 1-8 (e.g. 1, 2, 3, 4, 5, 6, 7 or 8) carbon atoms; more preferably a straight-chain alkyl, straight-chain alkoxy or an alkenyl containing 2 or 5 carbon atoms.

[0077] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to significantly improve low-temperature miscibility and reduce dielectric loss at high frequencies, the compound of general formula M contains at least one (e.g., one, two, three, four or five) compound selected from the group consisting of compounds of general formula M-1, compounds of general formula M-3, compounds of general formula M-10, compounds of general formula M-21 and compounds of general formula M-24.

[0078] In some embodiments of the present invention, in order to significantly improve the low-temperature miscibility and reduce the dielectric loss at high frequencies, the compound of general formula M accounts for 0.1%-50% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%. The percentages are 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 any two of these values. Preferably, the compound of general formula M accounts for 1%-5% of the weight percentage of the liquid crystal composition.

[0079] In some embodiments of the present invention, in order to significantly improve low-temperature miscibility and reduce dielectric loss at high frequencies, compounds selected from the group consisting of compounds of general formula M-1, general formula M-3, general formula M-10, general formula M-21, and general formula M-24 account for 1% to 5% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 1%, 2%, 3%, 4%, 5%, or any two of these values. Preferably, compounds selected from the group consisting of compounds of general formula M-1, general formula M-3, general formula M-10, general formula M-21, and general formula M-24 account for 2% to 4% of the weight of the liquid crystal composition.

[0080] In some embodiments of the present invention, the liquid crystal composition further comprises at least one compound of general formula III:

[0081]

[0082] Wherein, R4 represents a straight-chain or branched alkyl group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms. One or at least two non-adjacent -CH2- groups of the straight-chain or branched alkyl group containing 1-12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-;

[0083] ring and ring Each represents independently The above One or two -CH2- can be replaced by -O-, and a single bond in one or at most two rings can be replaced by a double bond;

[0084] Z3 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-;

[0085] X 11 ~X 14 Whether the two are the same or different, each can independently represent H, halogen, alkyl group containing 1-3 carbon atoms, or alkoxy group containing 1-3 carbon atoms;

[0086] n3 represents 0, 1, 2, and m3 represents 1, 2. When n3 = 2, Same or different, X 11 or X 12 Same or different;

[0087] When m3 = 2 Same or different, X 13 or X 14 Same or different, Z3 is the same or different.

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

[0089]

[0090] as well as

[0091]

[0092] Wherein, R4 has the same defined range as the compounds of general formula III described above; X 11 ~X 14 The same or different, each independently represents -H, halogen, alkyl containing 1-3 carbon atoms, alkoxy containing 1-3 carbon atoms.

[0093] In some embodiments of the invention, R4 represents an alkyl group containing 1-10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms. R4 is further preferably an alkyl or alkoxy group containing 2-7 (e.g., 2, 3, 4, 5, 6, 7) carbon atoms. R4 is further preferably an alkyl group containing 3 carbon atoms, an alkyl group containing 4 carbon atoms, or an alkyl group containing 5 carbon atoms.

[0094] In some embodiments of the present invention, the X 11 ~X 14 The same or different, each independently representing -H, -F, alkyl groups containing 1-3 carbon atoms, or alkoxy groups containing 1-3 carbon atoms. The X 11 ~X 14 Further preferred is that -H or -F are represented independently.

[0095] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy and absolute values ​​of dielectric anisotropy, the compound of general formula III comprises at least one (e.g., one, two, three, four or five) compound selected from the group consisting of compounds of general formula III-1, general formula III-2, general formula III-3, general formula III-5, general formula III-6 and general formula III-7.

[0096] In some embodiments of the present invention, the compound of general formula III is selected from the group consisting of the following compounds:

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] as well as

[0105]

[0106] Wherein, R4 has the same defined range as R4 in compounds of general formula III.

[0107] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula III comprises at least one (e.g., one, two, three, four, or five) compound selected from the group consisting of compounds of general formula III-1-1, compounds of general formula III-2-1, compounds of general formula III-3-4, compounds of general formula III-5-1, compounds of general formula III-6-4, and compounds of general formula III-7-1.

[0108] In some embodiments of the present invention, it is preferable to adjust the content of the compound of general formula III so that the liquid crystal composition containing it can effectively improve low-temperature miscibility, reduce the dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy and absolute values ​​of dielectric anisotropy.

[0109] In some embodiments of the invention, the compound of general formula III constitutes 0.1% to 50% by weight of the liquid crystal composition (inclusive of any value or subrange within this range), for example, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%. The percentages are 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 any two of these values. Preferably, the compound of formula III accounts for 1% to 15% of the weight of the liquid crystal composition.

[0110] In some embodiments of the invention, the compounds selected from the group consisting of compounds of general formula III-1, general formula III-2, general formula III-3, general formula III-5, general formula III-6, and general formula III-7 constitute 1% to 15% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or a range between any two of these values. Preferably, the compounds selected from the group consisting of compounds of general formula III-1, general formula III-2, general formula III-3, general formula III-4, general formula III-5, general formula III-6, and general formula III-7 constitute 2% to 14% of the liquid crystal composition by weight.

[0111] In some embodiments of the present invention, in order to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, the compound of general formula III-1 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or any two of these values. Preferably, the compound of general formula III-1 accounts for 2%-5% of the liquid crystal composition by weight.

[0112] In some embodiments of the present invention, in order to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, the compound of general formula III-2 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 3%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, the compound of general formula III-2 accounts for 2%-10% of the weight percentage of the liquid crystal composition.

[0113] In some embodiments of the present invention, in order to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, the compound of general formula III-3 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, the compound of general formula III-3 accounts for 2%-4% of the weight percentage of the liquid crystal composition.

[0114] In some embodiments of the present invention, in order to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, the compound of general formula III-5 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, the compound of general formula III-5 accounts for 2%-4% of the weight percentage of the liquid crystal composition.

[0115] In some embodiments of the present invention, in order to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy, and appropriate absolute values ​​of dielectric anisotropy, the compound of general formula III-6 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, the compound of general formula III-6 accounts for 2%-4% of the liquid crystal composition by weight.

[0116] In some embodiments of the present invention, in order to enable the liquid crystal composition containing it to effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies, the compound of general formula III-7 accounts for 2%-14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, the compound of general formula III-7 accounts for 2%-4% of the weight of the liquid crystal composition.

[0117] In some embodiments of the invention, compounds selected from the group consisting of compounds of general formula III-1-1, general formula III-2-1, general formula III-3-4, general formula III-5-1, general formula III-6-4, and general formula III-7-1 constitute 2% to 14% (inclusive of any value or subrange within this range) of the liquid crystal composition, for example, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or a range between any two of these values. Preferably, compounds from the group consisting of compounds of general formula III-1-1, general formula III-2-1, general formula III-3-4, general formula III-5-1, general formula III-6-4, and general formula III-7-1 constitute 2% to 11% of the liquid crystal composition by weight.

[0118] In addition to the compounds described above, the liquid crystal compositions of the present invention may also contain any one or a combination of at least two of the following: conventional nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, polymerizable monomers, dyes, and additives.

[0119] In some embodiments of the present invention, in order to further reduce dielectric loss at high frequencies, the liquid crystal composition further includes at least one dye molecule.

[0120] In a preferred embodiment, the dye molecule comprises any one or a combination of at least two of anthraquinone, azo, arylmethane, phthalocyanine, or thiophene.

[0121] In some embodiments of the present invention, the liquid crystal composition further includes at least one additive.

[0122] In a preferred embodiment, the additive includes any one or a combination of at least two of nitrogen-oxygen additives, dopants, antioxidants, ultraviolet absorbers, infrared absorbers, and light stabilizers.

[0123] In some embodiments of the present invention, the nitrogen-oxygen additive is selected from any one or a combination of at least two of the following compounds:

[0124]

[0125] Where n2 represents a positive integer from 1 to 18; "+" represents a free radical.

[0126] In a second aspect, the present invention provides a liquid crystal display device, the liquid crystal display device comprising the liquid crystal composition as described in the first aspect.

[0127] Compared with the prior art, the present invention has the following beneficial effects:

[0128] The liquid crystal composition provided by the present invention, through the relevant compounding of specific structures and contents of compounds, can effectively improve low-temperature miscibility, reduce dielectric loss of liquid crystal at high frequencies, and increase the tunability of liquid crystal at high frequencies while maintaining appropriate clearing points, appropriate optical anisotropy and absolute values ​​of dielectric anisotropy. Detailed Implementation

[0129] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0130] For ease of explanation, in the following embodiments, the group structures of each component in the liquid crystal composition are represented by the codes listed in Table 1:

[0131] Table 1. Group structure codes of liquid crystal compounds

[0132]

[0133]

[0134] In Table 1, short bonds represent access sites for functional groups.

[0135] Take the following compound with the following structural formula as an example:

[0136]

[0137] 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 cyclohexyl, G represents 2-fluoro-1,4-phenylene, and F represents fluorine.

[0138] In the following examples and comparative examples, the abbreviated codes for the performance test items are shown in Table 2:

[0139] Table 2. Abbreviations for Performance Test Items

[0140]

[0141]

[0142] in:

[0143] Cp: ​​Obtained by testing with a melting point apparatus.

[0144] Δn: Δn = n e -n0 was obtained by testing with an Abbe refractometer under a sodium lamp (589nm) light source at 25°C.

[0145] 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.

[0146] Δεr: The dielectric constant is divided into a component parallel to the long axis of the liquid crystal, “εr∥”, and a component perpendicular to it, “εr⊥”. The dielectric constant value is Δεr=εr / / -εr⊥.

[0147] tanδεr⊥, tanδεr / / : In physics, the quantitative expression of microwave "dielectric loss" is: the tangent of dielectric loss (tanδεr⊥, tanδεr / / ), which is a key dielectric performance parameter reflecting the liquid crystal material in a microwave field. Generally, the maximum dielectric loss is tanδεr max=max(tanδεr⊥, tanδεr / / ).

[0148] τ:τ≡(Δεr / εr||).

[0149] t: The time when the nematic liquid crystal medium is placed in a glass bottle, stored at low temperature, and when crystal precipitation is observed.

[0150] η: η≡(τ / tanδεr, max.), where the maximum dielectric loss is tanδεr, max.≡max.{tanδεr⊥;tanδεr||}.

[0151] The dielectric constants εr / / and εr⊥ at high frequencies, as well as the tangent values ​​of dielectric loss (tanδεr⊥ and tanδεr∥), can be tested using a vector network analyzer combined with the resonant cavity perturbation method.

[0152] The compounds used in the following examples can be synthesized using well-known methods or obtained commercially. These synthesis techniques are conventional, and the resulting liquid crystal compositions have been tested and found to meet electronic compound standards.

[0153] Liquid crystal compositions were prepared according to the proportions of the liquid crystal compositions in the following examples. The liquid crystal compositions were prepared according to conventional methods in the art, such as mixing in a specified proportion by heating, ultrasound, suspension, etc.

[0154] Comparative Example 1

[0155] This comparative example provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0156]

[0157]

[0158] Example 1

[0159] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0160]

[0161]

[0162] Example 2

[0163] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0164]

[0165] Example 3

[0166] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0167]

[0168] Example 4

[0169] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0170]

[0171]

[0172] Example 5

[0173] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0174]

[0175] Example 6

[0176] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0177]

[0178] Example 7

[0179] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0180]

[0181]

[0182] Example 8

[0183] This embodiment provides a liquid crystal composition comprising the components shown in the table below by weight percentage, and the composition is filled between two substrates of a liquid crystal device for performance testing:

[0184]

[0185]

[0186] To highlight the beneficial effects of the liquid crystal composition of the present invention, the inventors selected Comparative Example 1, which is similar to the embodiment system of the present invention. As can be seen from Comparative Example 1 and Examples 1-8, the liquid crystal composition of the present invention can effectively improve low-temperature miscibility, reduce dielectric loss of the liquid crystal at high frequencies, and increase the tunability of the liquid crystal at high frequencies.

[0187] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A liquid crystal composition, characterized in that, The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, and at least one compound of general formula M: as well as Wherein, R1, R2, and R3 independently represent straight-chain or branched alkyl groups containing 1-12 carbon atoms, straight-chain or branched alkoxy groups containing 1-12 carbon atoms, and straight-chain or branched alkenyl groups containing 2-12 carbon atoms. One or more non-adjacent -CH2- in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -O-, -CO-, -CO-O- or -O-CO-; R M1 and R M2 Each of these can be independently represented as a straight-chain or branched alkyl group containing 1-12 carbon atoms, a straight-chain or branched alkoxy group containing 1-12 carbon atoms, or a straight-chain or branched alkenyl group containing 2-12 carbon atoms. One or more non-adjacent -CH2- in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -O-, -CO-, -CO-O- or -O-CO-; ring ring ring ring and ring Whether they are the same or different, they are expressed independently. in One or more -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds; ring and ring Whether they are the same or different, they are expressed independently. or in One or more -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds. One or more -H can be replaced by -F or -Cl; X1~X 10 Whether the same or different, each can independently represent -H, halogen, alkyl group containing 1-3 carbon atoms, or alkoxy group containing 1-3 carbon atoms; Z1 and Z2 independently represent single bonds, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-; Z M1 It represents a single bond, -O-, -S-, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-; n represents 0, 1, 2, and m represents 1, 2. When n = 2, the ring... Same or different, X1 or X2 are the same or different; when m=2, the ring Same or different, X3 or X4 same or different, Z1 same or different; p represents 0 or 1, q represents 0 or 1; n M Represents 0, 1, 2, or 3, when n M When = 2 or 3, the ring Same or different, Z M1 Same or different.

2. The liquid crystal composition according to claim 1, characterized in that, The compounds of general formula I are selected from the group consisting of the following compounds: as well as 3. The liquid crystal composition according to claim 1 or 2, characterized in that, The compounds of general formula I are selected from the group consisting of the following compounds: as well as Wherein, R1 has the same defined range as in the compound of general formula I according to claim 1.

4. The liquid crystal composition according to claim 1, characterized in that, The compounds of general formula II are selected from the group consisting of the following compounds: as well as 5. The liquid crystal composition according to claim 1, characterized in that, The compounds of general formula M are selected from the group consisting of the following compounds: as well as 6. The liquid crystal composition according to claim 1, characterized in that, The liquid crystal composition further comprises at least one compound of general formula III: Wherein, R4 represents a straight-chain or branched alkyl group containing 1-12 carbon atoms. One or at least two non-adjacent -CH2- groups of the straight-chain or branched alkyl group containing 1-12 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-. ring and ring Each represents independently The above One or more of the -CH2- can be replaced by -O-, and one or at most two single bonds in the ring can be replaced by double bonds; Z3 represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, -CF2CF2-, -(CH2)4-, -CF2O-, or -OCF2-; X 11 ~X 14 Whether the same or different, each can independently represent -H, halogen, alkyl group containing 1-3 carbon atoms, or alkoxy group containing 1-3 carbon atoms; n3 represents 0, 1, 2, and m3 represents 1, 2. When n3 = 2, Whether the yang is the same or different, X 11 or X 12 Same or different; when m3 = 2, Same or different, X 13 or X 14 Same or different, Z3 is the same or different.

7. The liquid crystal composition according to any one of the preceding claims, characterized in that, The compounds of general formula III are selected from the group consisting of the following compounds: as well as 8. The liquid crystal composition according to any one of the preceding claims, characterized in that, The compounds of general formula III are selected from the group consisting of the following compounds: as well as 9. The liquid crystal composition according to any one of the preceding claims, characterized in that, The compound of general formula I accounts for 0.1%-95% of the liquid crystal composition by weight; the compound of general formula II accounts for 0.1%-50% of the liquid crystal composition by weight; the compound of general formula M accounts for 0.1%-50% of the liquid crystal composition by weight; and the compound of general formula III accounts for 0.1%-50% of the liquid crystal composition by weight.

10. A liquid crystal high-frequency phase modulation device, characterized in that, The liquid crystal high-frequency phase modulation device comprises a liquid crystal composition according to any one of claims 1 to 9.

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