Liquid crystal composition and use thereof

Abstract

The embodiments of the present application provide a liquid crystal composition and the use thereof. The liquid crystal composition comprises an additive and three types of compounds having specific structures. The liquid crystal composition has high birefringence and proper clearing point, is not prone to crystallization at low temperature, and has good stability of high-temperature resistance and ultraviolet resistance, and thus is suitable for being applied in liquid crystal devices.

Description

Liquid crystal composition and its application

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on February 19, 2024, with application number 202410186069.1 and application name “Liquid Crystal Compositions and Their Applications”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of liquid crystal materials, and in particular to a liquid crystal composition and its application. Background Art

[0003] Liquid crystal materials have been widely used in display applications such as tablet computers and televisions. With the advancement of technology, liquid crystal materials can also be applied to fields such as optical communications and microwave antennas. However, these fields place higher demands on the performance of liquid crystal materials, requiring them to have high birefringence and a suitable clearing point. Furthermore, liquid crystal materials must exhibit good stability. For example, liquid crystal devices made with liquid crystal materials must not experience a significant decrease in voltage retention after exposure to ultraviolet light or after being placed in a high-temperature environment for a period of time. However, the liquid crystal compositions currently commonly used in the industry, either using a single liquid crystal compound or a combination of multiple liquid crystal compounds, cannot achieve both high birefringence and good stability. Summary of the Invention

[0004] In view of this, the embodiments of the present application provide a liquid crystal composition and its application, which can take into account both high birefringence and good stability, and can be used to prepare liquid crystal devices with relatively excellent performance.

[0005] In a first aspect, an embodiment of the present application provides a liquid crystal composition, comprising at least one first compound represented by formula (I), at least one second compound represented by formula (II), at least one third compound represented by formula (III), and an additive:

[0006] Among them, R a 、R b Each occurrence is independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkenyloxy, substituted or unsubstituted alkynyl, substituted or unsubstituted alkynyloxy, and substituted or unsubstituted cycloalkyl; R c One selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkenyloxy group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyloxy group, and a substituted or unsubstituted cycloalkyl group;

[0007] Z1 and Z2 are independently selected from -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -CH2-CH2-, -CF2-CF2-, -CF2-CH2-, -CH2-CF2-, -CH2-O-, -O-CH2-, -CF2O-, -OCF2-, -CO-O-, -O-CO-, -N=N-, -CH=N-, -N=CH-, -C≡C-, -C≡CC≡C-, or a direct bond, but are not both -C≡C- or a direct bond;

[0008] R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 Each occurrence is independently selected from one of hydrogen atom, deuterium atom, tritium atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, unsubstituted cycloalkyl group, and in the formula (I), the formula (II) and the formula (III), R 8 With R 9 At least one of them is a hydrogen atom; X is selected from a halogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted alkoxy group.

[0009] By simultaneously using the three types of liquid crystal compounds with specific structures shown by the above-mentioned formula (I), formula (II) and formula (III), and additives, it is possible to ensure that the birefringence Δn of the above-mentioned liquid crystal composition is at a high level of above 0.32, and at the same time, its viscosity and clearing point are appropriate, it is not easy to crystallize at low temperatures, and its high temperature stability and anti-ultraviolet stability are good.

[0010] In some embodiments of the present application, in formula (III), Z1 is -C≡C- and Z2 is a direct bond; alternatively, Z1 is a direct bond and Z2 is -C≡C-. In this case, the substance represented by formula (III) is relatively easy to synthesize, and its addition to the liquid crystal composition can ensure better overall performance of the liquid crystal composition.

[0011] In the embodiment of the present application, the substituents in the substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkenyloxy, substituted alkynyl, and substituted alkynyloxy include one or more of a deuterium atom, a tritium atom, and a halogen atom; the substituents in the substituted cycloalkyl include one or more of a halogen atom, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkenyloxy, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkynyloxy, and a substituted or unsubstituted cycloalkyl. The introduction of various substituents can enrich the types of the three types of compounds of formula (I), formula (II), and formula (III), obtain compound products with slightly different properties, and better realize applications.

[0012] In the embodiment of the present application, the substituted or unsubstituted alkyl group is a substituted or unsubstituted C1 to C 20 Alkyl; the substituted or unsubstituted alkoxy is a substituted or unsubstituted C1~C 20 Alkoxy; the substituted or unsubstituted alkenyl is a substituted or unsubstituted C2~C 20 Alkenyl; the substituted or unsubstituted alkenyloxy group is a substituted or unsubstituted C2~C 20 Alkenyloxy; the substituted or unsubstituted alkynyl is a substituted or unsubstituted C2~C 20 Alkynyl; the substituted or unsubstituted alkynyloxy group is a substituted or unsubstituted C2~C 20 Alkynyloxy; the substituted or unsubstituted cycloalkyl is a substituted or unsubstituted C3~C 20 Each group has an appropriate number of carbon atoms, which not only makes the raw materials for preparing the compounds of formula (I), formula (II) and formula (III) easily available, but also ensures that the composition formed by mixing them has good liquid crystal properties.

[0013] In some embodiments of the present application, the X, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 wherein the substituted or unsubstituted alkyl group is a fluorinated or unsubstituted C1 to C8 alkyl group; the substituted or unsubstituted alkoxy group is a fluorinated or unsubstituted C1 to C8 alkoxy group; the unsubstituted cycloalkyl group is an unsubstituted C3 to C 10 Cycloalkyl.

[0014] In some embodiments of the present application, in the formula (I), the formula (II) and the formula (III), the R 6 With the R 7At least one of them is an H atom; in the formula (II) and the formula (III), R 4 With R 5 This ensures that the substances represented by the above formula (I), formula (II) and formula (III) are easy to obtain, and the composition formed by mixing them has good liquid crystal properties.

[0015] In an embodiment of the present application, in the liquid crystal composition, the mass percentage of the first compound is 1%-70%, the mass percentage of the second compound is 1%-70%, and the mass percentage of the third compound is 1%-70%. In some embodiments of the present application, in the liquid crystal composition, the mass percentage of the first compound is 1-20%, the mass percentage of the second compound is 15%-50%, and the mass percentage of the third compound is 40%-65%. Controlling the appropriate mass percentages of the above three types of compounds in the liquid crystal composition is beneficial for adjusting the viscosity, birefringence, and good stability of the liquid crystal composition.

[0016] In some embodiments of the present application, in the formula (I), the R 1 、R 6 、R 7 、R 8 、R 9 In this case, the substance of formula (I) is easier to obtain and is combined with the aforementioned R a 、R b The low-temperature stability of the substance represented by formula (I) can be maintained well.

[0017] In some embodiments of the present application, in the formula (II), the R 4 、R 5 、R 6 、R 7 、R 8 、R 9 In this case, the substance represented by formula (II) is easier to obtain and is not easy to crystallize at low temperatures.

[0018] In some embodiments of the present application, the at least one third compound includes one or more of the following:

[0019] Among them, the R 1 、The R 3 Each occurrence is independently selected from one of hydrogen atom, fluorine atom, fluorinated or unsubstituted alkyl, fluorinated or unsubstituted alkoxy; said R 8 Each occurrence is independently selected from a hydrogen atom or a fluorine atom; said Rc One selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and unsubstituted cycloalkyl.

[0020] In some embodiments of the present application, the at least one third compound includes one or more of the substance represented by formula (III-B) and the substance represented by formula (III-C), as well as the substance represented by formula (III-A). In this case, in the above-mentioned liquid crystal composition, at least the substances represented by formula (III-B) and / or formula (III-C), as well as the substances represented by formula (I), formula (II), and formula (III-A) and additives are combined to achieve a higher birefringence, a suitable clearing point, and better low-temperature, high-temperature, and ultraviolet stability.

[0021] In some embodiments of the present application, the mass percentage of the substance represented by formula (III-A), the substance represented by formula (III-B), and the substance represented by formula (III-C) in the liquid crystal composition is independently less than or equal to 50%.

[0022] In some embodiments of the present application, in the liquid crystal composition, the mass percentage of the substance represented by formula (III-A) is in the range of 14%-30%, the mass percentage of the substance represented by formula (III-B) is in the range of 0%-32%, and the total mass percentage of the substance represented by formula (III-C) in the liquid crystal composition is in the range of 8%-46%. Appropriate amounts of the substances represented by formula (III-A), formula (III-B), and formula (III-C) are combined with the substances represented by the above-mentioned formula (I) and formula (II), which is beneficial to the liquid crystal composition having lower viscosity, higher birefringence, and better stability.

[0023] In some embodiments of the present application, the liquid crystal composition further comprises a substance represented by the following formula (IV):

[0024] Among them, R 9 、R 10 The compound is independently selected from the group consisting of a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted alkoxy group. The substance represented by formula (IV) is introduced into the liquid crystal composition to improve the low-temperature stability of the liquid crystal composition, adjust the viscosity and clearing point, etc.

[0025] In the embodiments of the present application, the additives include one or more of hindered phenol additives, hindered amine additives, and benzotriazole additives. The additives in the liquid crystal composition are selected from one or more of these three categories, which significantly improves the high temperature resistance and UV resistance of the liquid crystal mixture system composed of the substances represented by formula (I), formula (II), and formula (III).

[0026] In the embodiment of the present application, the mass percentage of the additive in the liquid crystal composition is less than or equal to 5%. The introduction of an appropriate amount of the additive can effectively improve the various stabilities of the liquid crystal composition while not significantly affecting its birefringence properties.

[0027] In the embodiment of the present application, the birefringence of the liquid crystal composition is in the range of 0.32-0.42, the clearing point of the liquid crystal composition is in the range of 100-140° C., and the liquid crystal composition has no abnormality after being stored at -20° C. for 500 hours.

[0028] The second aspect of the present invention provides a use of the liquid crystal composition described in the first aspect of the present invention in a liquid crystal device. The liquid crystal composition can be used in the liquid crystal layer of the liquid crystal device to improve the performance of the liquid crystal device.

[0029] A third aspect of the embodiments of the present application provides a liquid crystal device, which includes a liquid crystal layer. The liquid crystal layer includes the liquid crystal composition described in the first aspect of the embodiments of the present application.

[0030] In some embodiments of the present application, the liquid crystal device includes a cover substrate, a transparent electrode layer, a first alignment layer, the liquid crystal layer, a second alignment layer, a passivation layer, a backplane electrode layer, and a silicon substrate stacked in sequence. In this case, the liquid crystal device may be an LCoS device.

[0031] A fourth aspect of the embodiments of the present application provides a device, comprising the liquid crystal device described in the third aspect of the embodiments of the present application. The device comprises one or more of a wavelength selective switch, a microwave scanning antenna, a liquid crystal optical antenna, a liquid crystal optical waveguide, a variable focus lens device, a liquid crystal prism, a grating, a laser radar, a beam tracker, a projector, an optical projection system, a flat panel display, a holographic display, an image acquisition device, an optical communication device, and a wireless communication device.

[0032] Based on the good performance of the above-mentioned liquid crystal device, the performance of various devices including the liquid crystal device is also relatively good, and the market competitiveness is outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic structural diagram of a liquid crystal device provided in an embodiment of the present application.

[0034] FIG2 is a schematic structural diagram of a wavelength selective switch provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0036] Liquid crystal materials have adjustable electro-optical properties, and liquid crystal devices made of liquid crystal materials have been widely used in display, optical communication, wireless communication, laser detection and other fields, such as vehicle-mounted display, laser projection, laser radar, wavelength selective switch (WSS), etc. Among them, liquid crystal devices made based on liquid crystal on silicon (LCoS, also known as liquid crystal on silicon) technology are widely used. Figure 1 is a structural schematic diagram of a liquid crystal device provided in an embodiment of the present application. In some embodiments, the liquid crystal device shown in Figure 1 can specifically be an LCoS device, which can be used in WSS, etc., and can be used as an optical switching engine of WSS to achieve phase modulation.

[0037] Referring to Figure 1 , a liquid crystal device 100 includes a cover plate 10, a silicon-based backplane 20, and a liquid crystal layer 30 disposed therebetween. The liquid crystal layer 30 includes a plurality of liquid crystal molecules (represented by black elliptical rods in Figure 1 ). The liquid crystal molecules can deflect under certain voltage conditions, achieving phase modulation of a light beam. The cover plate 10 may include a cover plate substrate 11 and a transparent electrode layer 12 disposed on one surface thereof. A first alignment layer 13 is also provided on the side of the transparent electrode layer 12 facing away from the cover plate substrate 11. The silicon-based backplane 20 includes a silicon substrate 21 and a backplane electrode layer 22 and a passivation layer 23 stacked sequentially on one surface of the silicon substrate 21. A second alignment layer 24 is also provided on the silicon-based backplane 20, specifically on the side of the passivation layer 23 facing away from the silicon substrate 21. When the cover plate 10 and the silicon-based backplane 20 are assembled into the liquid crystal device 100, they are disposed opposite each other, with the liquid crystal layer 30 located between the first alignment layer 13 and the second alignment layer 24. In this case, the liquid crystal device 100 includes a cover substrate 11, a transparent electrode layer 12, a first alignment layer 13, a liquid crystal layer 30, a second alignment layer 24, a passivation layer 23, a backplane electrode layer 22, and a silicon substrate 21, which are stacked in sequence. It should be understood that the size and position of each layer in the liquid crystal device 100 of FIG1 are for illustration only and do not constitute a limitation to the present application.

[0038] The cover substrate 11 is typically made of glass, which protects the liquid crystal layer 30, allows light signals to pass through, and supports the transparent electrode layer 12. The transparent electrode layer 12 can be made of, for example, an indium tin oxide (ITO) layer or an indium zinc oxide (IZO) layer, which has excellent conductivity and transparency, allowing light signals to pass through and conduct electricity. In some embodiments, the cover substrate 10 is made of ITO conductive glass.

[0039] The backplane electrode layer 22 is used to electrically connect to the transparent electrode layer 12 to form an electric field that can control the rotation of the liquid crystal molecules under the action of an external circuit. The backplane electrode layer 22 is generally a metal element or an alloy. The passivation layer 23 is generally made of a low-refractive-index dielectric material such as silicon oxide or silicon nitride, which can protect and planarize the backplane electrode layer 22. In addition, the silicon substrate 21 can include a drive circuit, which can be a CMOS (complementary metal oxide semiconductor) integrated circuit chip.

[0040] The first alignment layer 13 on the cover plate 10 and the second alignment layer 24 on the silicon-based backplane 20 can fix the alignment direction of the liquid crystal molecules in the liquid crystal layer 30 under zero voltage conditions. In some embodiments, when no voltage is applied to the liquid crystal layer 30, the first alignment layer 13 and the second alignment layer 24 control the parallel alignment of the liquid crystal molecules.

[0041] When a certain voltage is applied between the backplane electrode layer 22 and the transparent electrode layer 12 via the driving circuit in the silicon-based backplane 20, the liquid crystal molecules in the liquid crystal layer 30 rotate in response to the voltage. Because liquid crystal molecules exhibit birefringence under the influence of an electric field, different electric field intensities can cause the liquid crystal molecules to rotate to varying degrees, thereby changing their refractive index and adjusting the phase of the light beam transmitted through the liquid crystal molecules.

[0042] The liquid crystal layer 30 is generally formed by pouring a liquid crystal composition into the space reserved between the oppositely arranged cover plate 10 and the silicon-based back plate 20. The liquid crystal composition is usually formed by mixing multiple liquid crystal compounds (also known as liquid crystal monomers). However, the liquid crystal composition currently used in the liquid crystal device 100 cannot take into account a high birefringence, a suitable clearing point, and good stability, so that the device performance of the liquid crystal device cannot effectively meet the requirements of practical applications. To this end, the embodiments of the present application provide a liquid crystal composition with excellent comprehensive performance that can be used in the above-mentioned liquid crystal device 100 and related applications.

[0043] Specifically, an embodiment of the present application provides a liquid crystal composition, which includes a liquid crystal monomer and an additive, wherein the liquid crystal monomer includes at least one first compound represented by formula (I), at least one second compound represented by formula (II), and at least one third compound represented by formula (III):

[0044] Among them, R a 、R bEach occurrence is independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkenyloxy, substituted or unsubstituted alkynyl, substituted or unsubstituted alkynyloxy, and substituted or unsubstituted cycloalkyl; R c One selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkenyloxy group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyloxy group, and a substituted or unsubstituted cycloalkyl group;

[0045] Z1 and Z2 are independently selected from -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -CH2-CH2-, -CF2-CF2-, -CF2-CH2-, -CH2-CF2-, -CH2-O-, -O-CH2-, -CF2O-, -OCF2-, -CO-O-, -O-CO, -N=N-, -CH=N-, -N=CH-, -C≡C-, -C≡CC≡C-, or a direct bond, but are not both -C≡C- or a direct bond;

[0046] R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 Each occurrence is independently selected from one of hydrogen atom, deuterium atom, tritium atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, and unsubstituted cycloalkyl group, and in the above formula (I), formula (II) and formula (III), R 8 With R 9 At least one of them is a hydrogen atom; X is selected from a halogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted alkoxy group.

[0047] In the above-mentioned liquid crystal composition, by compounding three types of liquid crystal compounds with specific structures and with the help of additives, the birefringence Δn of the obtained liquid crystal composition can be ensured to be at a high level of above 0.32, and at the same time, its viscosity and clearing point are suitable, it is not easy to crystallize at low temperatures, and its high temperature stability and anti-ultraviolet stability are good. Among them, the above-mentioned non-hydrogen group R in formula (I), formula (II) and formula (III) a 、R b 、R cThis is beneficial for ensuring good low-temperature stability of the liquid crystal composition. In particular, the substance represented by formula (II) can ensure high birefringence performance of the liquid crystal composition. In the structure of formula (II), in which three benzene rings are sequentially connected by acetylenic bonds, the above-mentioned selection of the X group on the middle benzene ring is beneficial for maintaining the stability of the substance of formula (II), thereby improving the low-temperature stability of the overall liquid crystal composition.

[0048] Among the various choices of Z1 and Z2 mentioned above in the present application, -CH=CH- can be called 1,2-vinylene; -CF=CF- can be called perfluorovinylene; -CH=CF- or -CF=CH- can be called monofluorovinylene; -CH2-CH2- can be called 1,2-ethylene; -CF2-CF2- can be called perfluoroethylene; -CF2-CH2- or -CH2-CF2- can be called difluoroethylene; -CH2-O- or -O-CH2- can be called methylene ether bridge bond; -CF2O- or -OCF2- can be called difluoromethylene ether bridge bond; -CO-O- or -O-CO- can be called ester bond; -C≡C- can be called acetylenic bond, and -C≡CC≡C- can be called 1,3-diacetylenic bond.

[0049] In this application, when Z1 or Z2 in formula (III) is a linear bond, it represents a direct connection between two benzene rings. Restricting Z1 and Z2 from being linear bonds simultaneously ensures that the birefringence of the substance of formula (III) is high. Furthermore, restricting Z1 and Z2 from being -C≡C- simultaneously ensures that, when the selection range of R2 in formula (III) is the same as that of X, formula (III) and formula (II) are not identical general formulas.

[0050] In some embodiments of the present application, in formula (III), Z1 is -C≡C- and Z2 is a direct bond; alternatively, Z1 is a direct bond and Z2 is -C≡C-. In this case, the substance represented by formula (III) is relatively easy to synthesize, and its addition to the liquid crystal composition can ensure that the overall performance of the liquid crystal composition is good, especially high birefringence.

[0051] In this application, the above-mentioned "hydrogen atom" is also referred to as "protium atom ( 1 H)". Deuterium atom is also called "heavy hydrogen" and its chemical symbol is 2 H or D. The chemical symbol for tritium is 3 H. The halogen atom may be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), and fluorine atom is more common.

[0052] In the embodiment of the present application, the substituents in the above-mentioned substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkenyloxy, substituted alkynyl, substituted alkynyloxy include one or more of deuterium atom, tritium atom, and halogen atom. The substituents in the above-mentioned substituted cycloalkyl include one or more of halogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkenyloxy, substituted or unsubstituted alkynyl, substituted or unsubstituted alkynyloxy, substituted or unsubstituted cycloalkyl (such as alkyl-substituted cycloalkyl). The introduction of various substituents can make the compound species richer, obtain compound products with slightly different properties, and better realize application. Wherein, taking substituted alkyl as an example, "substitution" specifically refers to that any one or more hydrogen atoms in the alkyl are replaced by the above-mentioned substituents.

[0053] In some embodiments, the substituent in the substituted cycloalkyl group is selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkenyloxy group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyloxy group, or an alkyl-substituted or unsubstituted cycloalkyl group. In this case, the above compounds containing the substituted cycloalkyl group are easier to synthesize.

[0054] In some embodiments, the substituents in the above-mentioned substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkenyloxy, substituted alkynyl, and substituted alkynyloxy are halogen atoms. In this case, the substituted alkyl may be referred to as a haloalkyl, the substituted alkoxy may be referred to as a haloalkoxy, the substituted alkenyl may be referred to as a haloalkenyl, the substituted alkenyloxy may be referred to as a haloalkenyloxy, the substituted alkynyl may be referred to as a haloalkynyl, and the substituted alkynyloxy may be referred to as a haloalkynyloxy. Wherein, the halo may be partially halogenated or fully halogenated. "Partially halogenated" means that some of the hydrogen atoms in the above-mentioned groups are replaced by halogen atoms. "Fully halogenated" means that all of the hydrogen atoms in the above-mentioned groups are replaced by halogen atoms. In some embodiments, the halogen atom is a fluorine atom. In this case, taking haloalkyl as an example, it is specifically a fluoroalkyl.

[0055] In the present application, the substituted or unsubstituted alkyl mentioned above is a chain alkyl, which can be a straight chain alkyl or a branched chain alkyl. The substituted or unsubstituted alkyl can be a substituted or unsubstituted C1~C 20 Alkyl. In the case of a substituted alkyl group, the number of carbon atoms 1 to 20 specifically refers to the number of carbon atoms in the unsubstituted alkyl group corresponding to the substituted alkyl group. In some embodiments, the substituted or unsubstituted alkyl group is a substituted or unsubstituted C1 to C 20In this case, the mixture formed by mixing the above compounds with the substituted or unsubstituted straight-chain alkyl group can exhibit good liquid crystal properties. In some embodiments, the substituted or unsubstituted alkyl group is a substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted C1-C6 alkyl, etc., for example, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted n-propyl, substituted or unsubstituted n-butyl, substituted or unsubstituted n-pentyl, substituted or unsubstituted n-hexyl, etc. For example, the substituted alkyl group can be deuterated methyl, tritiated methyl, trifluoromethyl, deuterated ethyl, tritiated ethyl, fluoroethyl, deuterated propyl, tritiated propyl, fluoropropyl, fluoro-n-butyl, fluoro-n-pentyl, etc.

[0056] In the embodiment of the present application, the substituted or unsubstituted alkoxy group mentioned above is a chain alkoxy group, which can be a straight chain alkoxy group or a branched chain alkoxy group. Among them, the substituted or unsubstituted alkoxy group can be regarded as a structure after a substituted or unsubstituted alkyl group is connected to an oxygen atom. Therefore, the number of carbon atoms of the substituted or unsubstituted alkoxy group can refer to the description of the substituted or unsubstituted alkyl group in the previous text of this application. In the embodiment of the present application, the substituted or unsubstituted alkoxy group can be a substituted or unsubstituted C1~C 20 Alkoxy, further may be substituted or unsubstituted C1~C 10 In some embodiments, the substituted or unsubstituted alkoxy group may be a substituted or unsubstituted C1-C8 alkoxy group or a C1-C6 alkoxy group. 20 Straight chain alkoxy, C1~C 10 Straight chain alkoxy, C1 to C8 straight chain alkoxy or C1 to C6 straight chain alkoxy, etc. As examples, the substituted or unsubstituted alkoxy may be an unsubstituted methoxy (-OCH3), a fluoromethoxy (-OCF3), a deuterated methoxy, a tritiated methoxy, a substituted or unsubstituted ethoxy (-OCH2CH3), a substituted or unsubstituted propoxy (-OCH2CH2CH3), a substituted or unsubstituted butoxy (-OCH2CH2CH2CH3), etc.

[0057] In the embodiment of the present application, the substituted or unsubstituted alkenyl mentioned above can be a substituted or unsubstituted C2 to C 20 Alkenyl; the alkenyl is a chain alkenyl, specifically a straight chain alkenyl or a branched chain alkenyl. In some embodiments, the substituted or unsubstituted alkenyl is a substituted or unsubstituted C2-C 20 Straight chain alkenyl. The mixture formed by mixing the above compounds with the substituted or unsubstituted straight chain alkenyl can exhibit good liquid crystal properties. In some embodiments, the substituted or unsubstituted alkenyl can be a substituted or unsubstituted C2~C 10Chain alkenyl groups, substituted or unsubstituted C2-C6 chain alkenyl groups, for example, may be substituted or unsubstituted vinyl (e.g., CH2=CH-), substituted or unsubstituted propenyl, substituted or unsubstituted butenyl, etc. For example, the substituted alkenyl group may be deuterated vinyl, tritiated vinyl, fluorovinyl (e.g., CF2=CH-), fluoropropenyl, etc.

[0058] In the embodiment of the present application, the substituted or unsubstituted alkenyloxy group mentioned above is a chain alkenyloxy group, which can be a straight chain alkenyloxy group or a branched chain alkenyloxy group, and the straight chain alkenyloxy group is preferred. Among them, the substituted or unsubstituted alkenyloxy group can be regarded as a structure in which a substituted or unsubstituted alkenyl group is connected to an oxygen atom. Therefore, the number of carbon atoms of the substituted or unsubstituted alkenyloxy group can refer to the description of the substituted or unsubstituted alkenyl group in this application. In the embodiment of the present application, the substituted or unsubstituted alkenyloxy group can be a substituted or unsubstituted C2~C 20 Alkenyloxy, further may be substituted or unsubstituted C2~C 10 Alkenyloxy, or C2-C6 alkenyloxy, etc. As an example, the substituted or unsubstituted alkenyloxy may be substituted or unsubstituted ethyleneoxy, propyleneoxy, butenyloxy, etc.

[0059] In the embodiment of the present application, the substituted or unsubstituted alkynyl group mentioned above can be a substituted or unsubstituted C2 to C 20 Alkynyl; specifically, it can be a straight chain alkynyl or a branched chain alkynyl. In some embodiments, the substituted or unsubstituted alkynyl is a substituted or unsubstituted C2-C 20 Straight chain alkynyl. The mixture formed by mixing the above compounds with the substituted or unsubstituted straight chain alkynyl can exhibit good liquid crystal properties. The substituted or unsubstituted alkynyl can be a substituted or unsubstituted C2~C 10 Chain alkynyl, substituted or unsubstituted C2-C6 chain alkynyl, for example, can be substituted or unsubstituted ethynyl, substituted or unsubstituted propynyl, substituted or unsubstituted butynyl, etc. For example, the substituted alkynyl can be deuterated ethynyl, tritiated ethynyl, fluoroethynyl, fluoropropynyl, fluorobutynyl, etc.

[0060] In the embodiment of the present application, the substituted or unsubstituted alkynyloxy group mentioned above is a chain alkynyloxy group, which can be a straight chain alkynyloxy group or a branched chain alkynyloxy group, and the straight chain alkynyloxy group is preferred. Among them, the substituted or unsubstituted alkynyloxy group can be regarded as a structure after the substituted or unsubstituted alkynyl group is connected to the oxygen atom. Therefore, the number of carbon atoms of the substituted or unsubstituted alkynyloxy group can refer to the description of the substituted or unsubstituted alkynyl group in this application. In the embodiment of the present application, the substituted or unsubstituted alkynyloxy group can be a substituted or unsubstituted C2~C 20 Alkynyloxy, further may be substituted or unsubstituted C2-C 10Alkynyloxy, or C2-C6 alkynyloxy, etc. As an example, the substituted or unsubstituted alkynyloxy group may be substituted or unsubstituted ethynyloxy, propynyloxy, butynyloxy, etc.

[0061] In the embodiment of the present application, the substituted or unsubstituted cycloalkyl mentioned above can be a substituted or unsubstituted C3~C 20 In some embodiments, the substituted or unsubstituted cycloalkyl group is a substituted or unsubstituted C3 to C 10 Cycloalkyl, substituted or unsubstituted C3-C6 cycloalkyl, etc., for example, specifically substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, etc. For example, the substituted cycloalkyl can be deuterated cyclopentyl, tritiated cyclopentyl, methyl-substituted cyclopentyl, deuterated cyclohexyl, tritiated cyclohexyl, fluorocyclohexyl, methyl-substituted cyclohexyl, trifluoromethyl-substituted cyclohexyl, difluorovinyl-substituted cyclohexyl, etc.

[0062] In some embodiments of the present application, the above X, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 When X, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 When R is a substituted or unsubstituted alkoxy group, specifically a fluorinated or unsubstituted C1 to C8 alkoxy group, 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 When it is an unsubstituted cycloalkyl group, specifically an unsubstituted C3 to C 10 Cycloalkyl.

[0063] In the various formulas (I), (II) and (III) of the present application, R 8 With R 9 At least one of them is a hydrogen atom. 8 、R 9The above mentioned non-hydrogen groups (such as halogen atoms, alkyl groups, alkoxy groups, cycloalkyl groups, etc.) are not simultaneously used. This ensures that the mixture formed by the above mentioned compounds can exhibit good liquid crystal properties. 8 and R 9 The restrictions are all for R in the same general formula 8 and R 9 Similar expressions in the following text of this application should be understood in the same way. In some embodiments of this application, in each formula (I), formula (II) and formula (III), R 6 With R 7 At least one of them is a hydrogen atom. For example, taking formula (II) as an example, when R 9 is a hydrogen atom, R 8 When it is a non-hydrogen group, R 6 is a hydrogen atom, R 7 It can be a non-hydrogen group or a hydrogen atom. 8 is a hydrogen atom, R 9 When it is a non-hydrogen group, R 7 is a hydrogen atom, R 6 It can be a non-hydrogen group or a hydrogen atom. In addition, in some other embodiments of the present application, when R 6 、R 7 When neither is a hydrogen atom, then R 8 、R 9 All are hydrogen atoms.

[0064] In some embodiments of the present application, in formula (II) and formula (III), R 4 With R 5 At least one of them is a hydrogen atom. This ensures that the composition formed by mixing the substance represented by formula (II), the substance represented by formula (III) and the substance represented by formula (I) exhibits good liquid crystal properties. Taking formula (III) as an example, when R 3 When it is not a hydrogen atom, it can be R 4 and R 5 are all hydrogen atoms; R 4 is a hydrogen atom, R 5 is a non-hydrogen group, which can also be R 5 is a hydrogen atom, R 4 is a non-hydrogen group. Similarly, when R 3 When it is a hydrogen atom, it can be R 4 and R 5 are all hydrogen atoms, or R 4 and R 5 One of them is a hydrogen atom. Similarly, R 6 With R 8 At least one of them is a hydrogen atom, R 7 With R 9 At least one of them is a hydrogen atom.

[0065] In some embodiments of the present application, in formula (II) and formula (III), R 1 With R 4 At least one of them is a hydrogen atom, R 3 With R 6 At least one of them is a hydrogen atom, R 5 With R 9 At least one of them is a hydrogen atom. By limiting the adjacent groups on two adjacent benzene rings in the same general formula to not be non-hydrogen groups at the same time, the difficulty of synthesizing the substances represented by formula (II) and formula (III) can be greatly reduced.

[0066] In some embodiments of the present application, in formula (I), R 1 、R 6 、R 7 、R 8 、R 9 In this case, the formula (I) is specifically:

[0067] In some embodiments of the present application, in formula (II), R 6 、R 9 is a hydrogen atom. In this case, formula (II) is specifically:

[0068] In the formula, the meaning of each code is as defined in the previous application. 4 、R 5 At least one of them is a hydrogen atom; when R 4 When it is not a hydrogen atom, R 1 is a hydrogen atom. Further, R 4 、R 5 are all hydrogen atoms. 7 、R 8 At least one of them is a non-hydrogen group (e.g., both are fluorine atoms, or one is a hydrogen atom and the other is a fluorine atom, etc.), or both are hydrogen atoms. In some embodiments, in formula (II), R 4 、R 5 、R 6 、R 7 、R 8 、R 9 In this case, the formula (II) is specifically:

[0069] In some cases, in formula (II-a), R 1 、R 2 Can be independently selected from hydrogen atoms or fluorine atoms. For example, R 1 、R 2 All are hydrogen atoms, or all are fluorine atoms, etc.

[0070] In some other embodiments of the present application, in formula (II), R 7 、R 8 are all hydrogen atoms; R 6 、R 9 At least one of them is the aforementioned non-hydrogen group. Further, R 4 、R 5 are all hydrogen atoms. Furthermore, R 1 、R 2 They may all be hydrogen atoms.

[0071] It should be noted that the above-mentioned liquid crystal composition may include a first compound as represented by formula (I), or a plurality of first compounds having different structures conforming to formula (I). Similarly, the above-mentioned liquid crystal composition may include one or more second compounds as represented by formula (II), and one or more third compounds as represented by formula (III). The substances represented by formula (I), formula (II), and formula (III) are all constituent components of the liquid crystal monomers in the liquid crystal composition.

[0072] In an embodiment of the present application, in the liquid crystal composition, the total mass percentage of the first compound, the total mass percentage of the second compound, and the total mass percentage of the third compound are independently in the range of 1% to 70%. For example, the total mass percentages are independently 3%, 5%, 10%, 15%, 20%, 30%, 35%, 40%, 42%, 45%, 50%, 55%, 60%, 65%, or 68%.

[0073] In some embodiments, in the above-mentioned liquid crystal composition, the total mass percentage of the substance represented by formula (I) is in the range of 1%-20%, for example, specifically 2%, 5%, 8%, 9%, 10%, 11%, 12%, 15%, 18%, etc.; in some embodiments, the total mass percentage of the substance represented by formula (I) is 5%-15%. In the above-mentioned liquid crystal composition, the total mass percentage of the substance represented by formula (II) is in the range of 15%-50%, for example, specifically 20%, 22%, 24%, 25%, 27%, 28%, 30%, 32%, 34%, 36%, 40%, 42%, 45% or 48%, etc.; in some embodiments, the total mass percentage of the substance represented by formula (II) is 20%-45%. In the above-mentioned liquid crystal composition, the total mass percentage of the substance represented by formula (III) is in the range of 40%-65%, for example, specifically 42%, 43%, 45%, 46%, 47%, 48%, 50%, 52%, 55%, 57%, 60%, 62%, or 64%. In some embodiments, the total mass percentage of the substance represented by formula (III) is 45%-65%. Controlling the liquid crystal composition to contain a certain amount of the substance represented by formula (I), the substance represented by formula (II), and the substance represented by formula (III) is beneficial for the liquid crystal composition to have low viscosity, high birefringence, good light / heat stability, etc.

[0074] In some embodiments of the present application, the liquid crystal composition includes at least one third compound as shown in the following formula (III-A), the following formula (III-B), or the following formula (III-C). In other words, the general formula shown in the above formula (III) includes one or more of the following formulas (III-A), (III-B), and (III-C).

[0075] Among them, in formula (III-A), formula (III-B) and formula (III-C), the selection range of each code is as defined above in this application.

[0076] Wherein, the structure shown in formula (III-A) corresponds to Z1 in the aforementioned formula (III) as a direct bond, Z2 as -C≡C-, and R 1 to R 5 、R 7 With R 8 are all hydrogen atoms, R 6 With R 9 The structure shown in formula (III-B) corresponds to the above formula (III) where Z1 is a direct bond, Z2 is -C≡C-, and R 2 、R 3 、R 4 、R 5 、R 6 and R 9 is a hydrogen atom, R 7 With Rc The structure shown in formula (III-C) corresponds to Z1 in the above formula (III) being -C≡C-, Z2 being a direct bond, and R 1 、R 2 、R 4 、R 5 、R 6 、R 9 are all hydrogen atoms, R 6 With R c All are fluorine atoms.

[0077] In some embodiments of the present application, in formula (III-A), R c is selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and unsubstituted cycloalkyl. In formula (III-B) and formula (III-C), R 8 Each occurrence is independently selected from a hydrogen atom (H) or a fluorine atom (F); R 1 、R 3 Each occurrence is independently selected from one of hydrogen atom (H), fluorine atom (F), fluorinated or unsubstituted alkyl, and fluorinated or unsubstituted alkoxy. In this case, the compounds represented by formula (III-A), formula (III-B), and formula (III-C) are easier to synthesize and have a suitable viscosity. Furthermore, R 1 、R 3 Independently selected from H, or F, or unsubstituted C1-C6 alkyl (such as methyl, ethyl, n-propyl, etc.).

[0078] In the present application, the total mass percentage of the substance represented by formula (III-A), the substance represented by formula (III-B), and the substance represented by formula (III-C) in the above-mentioned liquid crystal composition is independently less than or equal to 50%. For example, the total mass percentage of the substance represented by formula (III-A) in the liquid crystal composition is in the range of 1%-50%, and the total mass percentage of the substance represented by formula (III-B) and the substance represented by formula (III-C) in the liquid crystal composition is independently in the range of 0%-50%. In some embodiments, the total mass percentage of the substance represented by formula (III-A) in the liquid crystal composition is in the range of 14%-30%, for example, specifically 15%, 16%, 20%, 25%, 25%, or 29%. The total mass percentage content of the substance represented by formula (III-B) in the liquid crystal composition is in the range of 0% to 32%, and can further be in the range of 1% to 31%, for example, specifically 5%, 10%, 15%, 20%, 22%, 25%, 26%, 28% or 30%. The total mass percentage content of the substance represented by formula (III-C) in the liquid crystal composition is in the range of 8% to 46%, for example, specifically 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 42% or 45%.

[0079] In some embodiments of the present application, the general formula represented by the above formula (III) includes one or more of formula (III-B) and formula (III-C), and formula (III-A).

[0080] In some embodiments of the present application, the liquid crystal monomers in the liquid crystal composition include a substance represented by formula (I-a), a substance represented by formula (II-a), and a substance represented by formula (III-A), as well as one or more of a substance represented by formula (III-B) and a substance represented by formula (III-C). In other words, the liquid crystal composition includes substances represented by formula (I-a), formula (II-a), formula (III-A), formula (III-B), and formula (III-C) at the same time; or includes substances represented by formula (I-a), formula (II-a), formula (III-A), and formula (III-B); or includes substances represented by formula (I-a), formula (II-a), formula (III-A), and formula (III-C). In this case, the liquid crystal composition has a higher birefringence and a relatively lower clearing point, which facilitates the subsequent processing and utilization of the liquid crystal composition. At the same time, it has a lower viscosity and higher stability, and various properties can be better balanced, which has greater application prospects.

[0081] In some embodiments of the present application, the liquid crystal monomer in the above liquid crystal composition further comprises a substance represented by the following formula (IV):

[0082] Among them, R 9 、R 10 is independently selected from one of hydrogen atom, deuterium atom, tritium atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group. a 、R b The meaning of can be found in the description above. a 、R b wherein one of the above-mentioned groups is a substituted or unsubstituted cycloalkyl group. Introducing the substance represented by the above-mentioned formula (IV) as a liquid crystal monomer into the above-mentioned liquid crystal composition can improve the low-temperature stability of the liquid crystal composition, adjust the viscosity and clearing point, etc. In the embodiment of the present application, the total mass percentage of the substance represented by the above-mentioned formula (IV) in the liquid crystal composition is less than or equal to 5%, for example, specifically 0.1%, 0.5%, 1%, 2%, 3%, 4%, 4.5% or 5%.

[0083] The liquid crystal composition in the present application contains additives, and the presence of the additives can help improve the tolerance of the liquid crystal mixed system composed of the above-mentioned various liquid crystal monomers to ultraviolet light, high temperature, oxidation resistance, etc. In the embodiment of the present application, the additives in the above-mentioned liquid crystal composition may include one or more of hindered phenol additives, hindered amine additives, and benzotriazole additives, but are not limited thereto. The additives in the liquid crystal composition are selected from one or more of these three categories, which greatly helps to improve the stability of the liquid crystal mixed system composed of the substances represented by the above formula (I), formula (II), and formula (III). In some embodiments, the additives include hindered phenol additives, hindered amine additives, and benzotriazole additives at the same time. As a result, the above-mentioned liquid crystal composition can obtain higher light / heat stability.

[0084] In the embodiments of the present application, the weight percentage of the additive in the liquid crystal composition is less than or equal to 5%, that is, within the range of greater than 0 to less than or equal to 5%. The appropriate amount of additive introduced into the liquid crystal composition can effectively improve the light resistance, heat resistance, and oxidation resistance of the liquid crystal composition while not significantly affecting its birefringence.

[0085] In some embodiments of the present application, the hindered amine additive may include a general formula as shown in the following formula (V):

[0086] Wherein, each occurrence of R is independently selected from hydrogen, oxygen or C1-C4 alkyl; Y is selected from linear alkylene with 3-10 carbon atoms. Specifically, in R, C1-C4 alkyl can be methyl, ethyl, propyl, butyl, etc. Wherein, Y can be represented by -(CH2) n -, n is an integer between 3 and 10, for example, specifically 4, 5, 6, 7, 8 or 9.

[0087] For example, the hindered amine additive may be selected from one or more of the following substances:

[0088] Among them, O* can also be called "oxygen free radicals".

[0089] In some embodiments of the present application, the benzotriazole additive includes the general formula shown in the following formula (VI-A) and / or the general formula shown in the following formula (VI-B):

[0090] wherein Y1 is selected from a hydrogen atom or a halogen atom, and Y2 is independently selected from a hydrogen atom, a C1 to C2 substituted or unsubstituted halogen atom, 20 Alkyl, Y3, Y4, Y5 are independently selected from C1 to C1 substituted or unsubstituted by one or more halogen atoms or ester groups 20Alkyl. The substituted or unsubstituted alkyl group here can be a chain alkyl group, such as a straight chain alkyl group or a branched chain alkyl group. The ester group can be represented by -COOR', and R' can be an alkyl group.

[0091] In some embodiments, Y1 is a fluorine atom or a chlorine atom. Y2 is a branched alkyl group, such as an isopropyl group or a tert-butyl group (i.e., -C(CH3)3, abbreviated as t-Bu). Y3 is a substituted or unsubstituted straight-chain alkyl group or a branched alkyl group, such as a methyl group, an ethyl group, a tert-butyl group, -C(CH3)2-CH2-C(CH3)3, -CH2CH2-COOC7H 15 、-CH2CH2-COOC9H 19 Y4 and Y5 can independently be methyl, ethyl, tert-butyl, -C(CH3)2-CH2-C(CH3)3, etc.

[0092] For example, the benzotriazole additive may be selected from one or more of the following substances:

[0093] In the embodiment of the present application, the hindered phenol additive may have one or more of the following structures:

[0094] wherein each R" is independently selected from C1 to C2 substituted or unsubstituted by one or more halogen atoms or ester groups. 10 Alkyl. The substituted or unsubstituted alkyl group here may be a chain alkyl group, such as a straight chain alkyl group or a branched chain alkyl group.

[0095] In embodiments of the present application, the birefringence of the liquid crystal composition can be greater than 0.32, for example, within the range of 0.32-0.42. A higher birefringence is more advantageous for applications in optical communications, wireless communications, and the like. Δn can be determined using industry-recognized testing methods. For example, Δn can be 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, and the like.

[0096] In the embodiment of the present application, the clearing point of the above-mentioned liquid crystal composition is in the range of 100-140°C. The term "clearing point" (English: clearing point) refers to the critical temperature when the liquid crystal substance changes to the liquid state, that is, the highest temperature at which the liquid crystal state can exist. The clearing point of the liquid crystal composition is in a suitable range, which can not only ensure that the temperature of the subsequent heating process of the liquid crystal composition is not too high, but also ensure that the liquid crystal composition can stably maintain the liquid crystal state at a relatively high temperature and does not cause the liquid crystal device to fail. Specifically, the clearing point of the liquid crystal composition can be 105°C, 110°C, 115°C, 120°C, 122°C, 125°C, 130°C, 133°C, 135°C, or 138°C, etc. Among them, the clearing point of the liquid crystal composition can be obtained by using a curve measured by a differential scanning calorimetry (DSC) instrument.

[0097] In the embodiment of the present application, the above-mentioned liquid crystal composition has no abnormalities after being stored at -20°C for 500 hours. The "abnormality" here mainly refers to that after the liquid crystal composition is poured into the liquid crystal box and stored at -20°C for 500 hours, no abnormal phenomena such as color patterns, blackening, or darkening appear in the box. This reflects that the crystallization point or freezing point of the liquid crystal composition is low and the low-temperature stability is good. The liquid crystal device made of the liquid crystal composition can be used in a low-temperature environment. In some embodiments, the above-mentioned liquid crystal composition has no abnormalities after being stored at -30°C for 500 hours, and its low-temperature resistance is better.

[0098] The present application also provides an embodiment of the present invention for use of the aforementioned liquid crystal composition in a liquid crystal device. The liquid crystal composition is primarily used in the liquid crystal layer of the liquid crystal device. It is understood that a liquid crystal device includes a liquid crystal layer. Generally, the liquid crystal device includes a first substrate with a first electrode layer, a second substrate with a second electrode layer, and a liquid crystal layer disposed between the first and second substrates.

[0099] In the embodiments of the present application, the liquid crystal device can be applied to scenarios such as optical communication, wireless communication, microwave scanning antenna, variable focus lens, grating, laser radar, beam tracking, unmanned driving, projection, flat panel display, holographic display, etc. For example, the liquid crystal device can be used in optical communication equipment, wireless communication equipment, microwave scanning antenna, liquid crystal optical antenna, liquid crystal optical waveguide, wavelength selective switch, variable focus lens device (such as liquid crystal lens, liquid crystal glasses), liquid crystal prism, grating, laser radar, beam tracker, projector, optical projection system, flat panel display, holographic display, or image acquisition equipment, as one or more components thereof.

[0100] For example, the optical projection system can be an AR HUD (Augmented Reality-head up display) system, which can be used in vehicle displays. The flat panel display can be a TFT-LCD (Thin Film Transistor-Liquid Crystal Display), which can be used in smartphones, tablet computers, or televisions. For example, a TFT-LCD display generally includes a TFT array substrate, a color filter (CF) substrate, and a liquid crystal layer sandwiched between the two. Among them, the TFT substrate is mainly responsible for electrical signal transmission. The CF substrate mainly provides the color required for the display. In addition, the holographic display can be a display using holographic polymer dispersed liquid crystal (HPDLC); the grating can be a grating using HPDLC. Optical communication equipment and lidar can use wavelength selective switches.

[0101] In some embodiments of the present application, the liquid crystal device is specifically used in a wavelength selective switch (WSS). In this case, the liquid crystal device may be the LCoS device shown in Figure 1 , as described above. The WSS modulates the phase of an optical signal through the LCoS device, thereby changing the transmission direction of the optical signal.

[0102] Refer to Figure 2, which is a schematic diagram of the structure of a wavelength selective switch (WSS). In addition to the above-mentioned liquid crystal device 100, the wavelength selective switch 200 may also include at least one input port 201 and at least one output port 202. The optical signal can be input from at least one of the multiple input ports 201, modulated by the liquid crystal device 100, and output from at least one of the multiple output ports 202, thereby completing the change of the transmission direction of the optical signal, such as completing the exchange, upload or download of the optical signal. The number of input ports 201 and output ports 202 can be equal or different, and this application does not limit this. The input port 201 and the output port 202 can be composed of optical fibers, and the input / output ports can form an input / output optical fiber array.

[0103] It should be understood that the WSS structure diagram shown in Figure 2 is for illustrative purposes only. The WSS may also include optical path changing devices known in the art, such as gratings, lenses, reflectors, and collimators, which are not limited in this application. For example, in some embodiments, a grating may be provided between the input port 201 and the liquid crystal device 100. The grating can be used to spatially demultiplex optical signals of different wavelengths. The lens can be used to focus or collimate light. The reflector is used to reflect light.

[0104] The phase modulation amount Φ of the liquid crystal device, the birefringence Δn of the device, and the cell thickness d of the liquid crystal device satisfy the following relationship: Φ=2π×Δn×d / λ

[0105] It can be seen that, when the box thickness d is constant, the larger the Δn of the liquid crystal material, the greater the phase modulation amount of the device. In addition, when the phase modulation amount Φ is constant, the larger the Δn, the smaller the box thickness d can be. A smaller box thickness d can reduce the edge field effect of the liquid crystal device and shorten the response time. A higher Δn is also beneficial to improving the resolution of the device. Therefore, when the WSS includes a liquid crystal device 100 using the liquid crystal composition of the embodiment of the present application, the WSS can support a larger phase and dielectric modulation, with a faster switching speed and higher resolution. In addition, due to the good stability of the liquid crystal composition of this embodiment, the performance of the liquid crystal device using it is relatively stable, and its voltage retention rate does not decrease significantly after being irradiated with ultraviolet light or placed in a high temperature environment for a period of time.

[0106] Furthermore, due to the high birefringence of the liquid crystal compositions of the embodiments of the present application, liquid crystal devices using the liquid crystal compositions of the embodiments of the present application have better performance, which in turn facilitates their application in display, communications, and other fields. For example, a variable focus lens device using the liquid crystal compositions of the embodiments of the present application can achieve greater zoom capability; a grating (such as a holographic grating) using the liquid crystal compositions of the embodiments of the present application can have a wider field of view; a holographic display, projector, etc. using the liquid crystal compositions of the embodiments of the present application can have a greater depth of field; and a TFT-LCD display using the liquid crystal compositions of the embodiments of the present application can have higher resolution and shorter response time.

[0107] The present application also provides an apparatus comprising the aforementioned liquid crystal device according to the present application. The apparatus may be one or more of a wavelength selective switch, a microwave scanning antenna, a liquid crystal optical antenna, a liquid crystal optical waveguide, a variable focus lens device, a liquid crystal prism, a grating, a laser radar, a beam tracker, a projector, an optical projection system, a flat panel display, a holographic display, an image acquisition device, an optical communication device, or a wireless communication device. The apparatus utilizing the liquid crystal device according to the present application exhibits excellent performance and stable operation.

[0108] The embodiments of the present application are further described below with reference to a number of embodiments.

[0109] Before introducing the specific embodiments of the present application, the structures and abbreviations of some substances used in the following text of the present application are first introduced.

[0110] Example 1

[0111] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (0.5 parts by weight of additive 1 represented by formula (VI-A-1) and 0.5 parts by weight of additive 3 represented by formula (V-1)), wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0112] Compound of formula (I-1) (abbreviated as 3PTP1): 5 wt%;

[0113] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 3 wt%;

[0114] Compound of formula (II-1) (abbreviated as 3UTGTP5): 8 wt%;

[0115] Compound of formula (II-2) (abbreviated as 3PTGTP5): 8 wt%;

[0116] Compound of formula (II-3) (abbreviated as 4PTGTP3): 8 wt%;

[0117] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 10 wt%;

[0118] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 10 wt%;

[0119] Compound of formula (III-A-3) (abbreviated as 2PPTUI3): 10 wt%;

[0120] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 9 wt%;

[0121] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 8 wt%;

[0122] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 9 wt%;

[0123] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 9 wt%;

[0124] Compound of formula (IV-1) (abbreviated as 3CPO(2)): 3 wt%.

[0125] Example 2

[0126] A liquid crystal composition comprises 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1). The liquid crystal monomer comprises the following compounds in the following weight percentages:

[0127] Compound of formula (I-1) (abbreviated as 3PTP1): 6 wt%;

[0128] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 5 wt%;

[0129] Compound of formula (II-1) (abbreviated as 3UTGTP5): 12 wt%;

[0130] Compound of formula (II-2) (abbreviated as 3PTGTP5): 8 wt%;

[0131] Compound of formula (II-3) (abbreviated as 4PTGTP3): 8 wt%;

[0132] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 10 wt%;

[0133] Compound of formula (III-A-3) (abbreviated as 2PPTUI3): 10 wt%;

[0134] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 5 wt%;

[0135] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 10 wt%;

[0136] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 13 wt%;

[0137] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 8 wt%;

[0138] Compound of formula (IV-1) (abbreviated as 3CPO(2)): 5 wt%.

[0139] Example 3

[0140] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0141] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 11 wt%;

[0142] Compound of formula (II-2) (abbreviated as 3PTGTP5): 10 wt%;

[0143] Compound of formula (II-3) (abbreviated as 4PTGTP3): 10 wt%;

[0144] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 7 wt%;

[0145] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 16 wt%;

[0146] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 16 wt%;

[0147] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 15 wt%;

[0148] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 15 wt%.

[0149] Example 4

[0150] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0151] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 11 wt%;

[0152] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 7 wt%;

[0153] Compound of formula (II-5) (abbreviated as 4PTP(1)TP2): 10 wt%;

[0154] Compound of formula (II-6) (abbreviated as 5PTP(1)TP2): 10 wt%;

[0155] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 16 wt%;

[0156] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 15 wt%;

[0157] Compound of formula (III-C-2) (abbreviated as 3PTGGF): 15 wt%;

[0158] Compound of formula (III-C-3) (abbreviated as 3PTGUF): 16 wt%.

[0159] Example 5

[0160] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0161] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 10 wt%;

[0162] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 8 wt%;

[0163] Compound of formula (II-5) (abbreviated as 4PTP(1)TP2): 8 wt%;

[0164] Compound of formula (II-6) (abbreviated as 5PTP(1)TP2): 8 wt%;

[0165] Compound of formula (II-3) (abbreviated as 4PTGTP3): 5 wt%;

[0166] Compound of formula (II-7) (abbreviated as 4PTGTP5): 5 wt%;

[0167] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 10 wt%;

[0168] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 5 wt%;

[0169] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 6 wt%;

[0170] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 8 wt%;

[0171] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 12 wt%;

[0172] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 4 wt%;

[0173] Compound of formula (III-C-2) (abbreviated as 3PTGGF): 3 wt%;

[0174] Compound of formula (III-C-3) (abbreviated as 3PTGUF): 8 wt%.

[0175] Example 6

[0176] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0177] Compound of formula (I-1) (abbreviated as 3PTP1): 5 wt%;

[0178] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 3 wt%;

[0179] Compound of formula (II-1) (abbreviated as 3UTGTP5): 2 wt%;

[0180] Compound of formula (II-2) (abbreviated as 3PTGTP5): 8 wt%;

[0181] Compound of formula (II-3) (abbreviated as 4PTGTP3): 8 wt%;

[0182] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 3 wt%;

[0183] Compound of formula (II-5) (abbreviated as 4PTP(1)TP2): 4 wt%;

[0184] Compound of formula (II-6) (abbreviated as 5PTP(1)TP2): 4 wt%;

[0185] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 10 wt%;

[0186] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 5 wt%;

[0187] Compound of formula (III-A-3) (abbreviated as 2PPTUI3): 10 wt%;

[0188] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 9 wt%;

[0189] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 8 wt%;

[0190] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 9 wt%;

[0191] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 9 wt%;

[0192] Compound of formula (IV-1) (abbreviated as 3CPO(2)): 3 wt%.

[0193] Example 7

[0194] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (the composition is the same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0195] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 11 wt%;

[0196] Compound of formula (II-3) (abbreviated as 4PTGTP3): 10 wt%;

[0197] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 7 wt%;

[0198] Compound of formula (II-8) (abbreviated as 4PTGP5): 10 wt%;

[0199] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 16 wt%;

[0200] Compound of formula (III-B-4) (abbreviated as 3PPTUF): 16 wt%;

[0201] Compound of formula (III-B-5) (abbreviated as 3PPTGF): 15 wt%;

[0202] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 15 wt%.

[0203] After storage at -30°C for 500 hours (approximately 20.8 days), each liquid crystal composition showed no abnormalities, including color patterns, blackening, or darkening, and no crystallization. This indicates that the crystallization point of each liquid crystal composition was less than -30°C. Furthermore, even when the liquid crystal compositions did not contain any additives, their crystallization points remained below -30°C.

[0204] Differential scanning calorimetry (DSC) was used to measure the calorimetric performance of each liquid crystal composition to obtain a DSC curve from which the clearing point (Cp) in °C was read. The ordinary refractive index (n) of each liquid crystal composition at 25 °C and 589 nm light was measured using an ATAGO-DR-M4 Abbe refractometer. o ) and the extraordinary refractive index (n e The difference between the two is the birefringence Δn. The test results of the clearing point and birefringence Δn are summarized in Table 1 below.

[0205] Table 1

[0206] It can be seen from Table 1 that the birefringence Δn of the above-mentioned liquid crystal compositions provided in the embodiments of the present application is relatively high, Δn being above 0.33; the clearing points of the above-mentioned liquid crystal compositions are suitable, being within the range of 120-140°C, which is convenient for their subsequent applications.

[0207] Taking the liquid crystal composition of Example 1 as an example, its high temperature stability and ultraviolet (UV) resistance were tested and compared with a liquid crystal composition without additives under the same conditions (recorded as Comparative Example 1).

[0208] High-temperature stability test: Each liquid crystal composition was poured into a 7μm-thick TN-type liquid crystal cell, sealed with a sealing adhesive, and cured. The resulting liquid crystal cell samples were then tested for voltage holding ratio (VHR0). The liquid crystal cell samples were then placed in an adjustable temperature oven set at 100°C. The VHR of the liquid crystal cell samples was measured after being exposed to 100°C for various periods of time, and the change in voltage holding ratio (i.e., ΔVHR, which is equal to VHR0 - VHR) was calculated.

[0209] UV resistance test: Each liquid crystal composition was poured into a TN-type liquid crystal cell with a cell thickness of 7μm, sealed with a sealing adhesive, and cured. The resulting liquid crystal cell samples were placed in a UV test chamber. The voltage holding ratio change (ΔVHR) and the degree of color change of each liquid crystal cell sample after being irradiated with a certain cumulative dose of UV light were tested.

[0210] The VHRs were tested using the ALCT-IV1 LCD comprehensive parameter tester under the following conditions: 25°C, 5V, and 60Hz.

[0211] The degree of color change can be measured by the color coordinate offset value ΔE and the change in yellowness index (YI) ΔYI. 2 +(Δa) 2 +(Δb) 2 ] 1 / 2 ΔL, Δa, and Δb represent the changes in the L, a, and b values ​​of the liquid crystal cell test sample in the Lab chromaticity coordinates before and after UV light exposure, respectively. A larger ΔE value indicates a greater color difference, while a smaller ΔE value indicates a smaller color difference.

[0212] Table 2 High temperature stability test results

[0213] Table 3 UV resistance test results

[0214] As can be seen from Tables 2 and 3, the liquid crystal composition of Example 1 of the present application, containing the additive, exhibits excellent high-temperature resistance and strong UV resistance. A liquid crystal cell fabricated using this composition exhibits a ΔVHR of less than 2.2% after exposure to 100°C for 240 hours. Furthermore, the composition exhibits minimal color change after exposure to a cumulative dose of 40 J of UV light. This demonstrates that the addition of the additive improves the liquid crystal composition's high-temperature resistance and UV yellowing, ensuring excellent and stable performance in practical applications of liquid crystal devices.

[0215] Example 8

[0216] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive 3 represented by formula (V-1), wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0217] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 10 wt%;

[0218] Compound of formula (II-4) (abbreviated as 4PTGfTP3): 8 wt%;

[0219] Compound of formula (II-5) (abbreviated as 4PTP(1)TP2): 8 wt%;

[0220] Compound of formula (II-6) (abbreviated as 5PTP(1)TP2): 8 wt%;

[0221] Compound of formula (II-3) (abbreviated as 4PTGTP3): 5 wt%;

[0222] Compound of formula (II-7) (abbreviated as 4PTGTP5): 5 wt%;

[0223] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 10 wt%;

[0224] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 5 wt%;

[0225] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 6 wt%;

[0226] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 8 wt%;

[0227] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 12 wt%;

[0228] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 4 wt%;

[0229] Compound of formula (III-C-2) (abbreviated as 3PTGGF): 3 wt%;

[0230] Compound of formula (III-C-3) (abbreviated as 3PTGUF): 8 wt%.

[0231] Example 9

[0232] A liquid crystal composition comprises 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8) and 1 part by weight of an additive 1 represented by formula (VI-A-1).

[0233] Example 10

[0234] A liquid crystal composition comprises 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8) and 1 part by weight of additives 2 and 5 represented by formula (VI-A-2).

[0235] Example 11

[0236] A liquid crystal composition comprises 100 parts by weight of a liquid crystal monomer (the formulation is the same as in Example 8), 0.5 parts by weight of additives 2 and 5 represented by formula (VI-A-2), and 0.5 parts by weight of additive 3 represented by formula (V-1).

[0237] Comparative Example 2

[0238] A liquid crystal composition, which differs from Example 8 only in that it does not contain additives.

[0239] The high temperature stability of the liquid crystal cell samples prepared from the liquid crystal compositions of Examples 8-11 and Comparative Example 2 was tested, and the results are summarized in Table 4 below.

[0240] Table 4

[0241] As can be seen from Table 4, for liquid crystal compositions with the same liquid crystal monomer composition, the type and amount of additives can have different effects on the high-temperature stability of the liquid crystal compositions. Overall, the liquid crystal compositions of Examples 8-11 containing additives exhibited greater high-temperature stability than the comparative example 2, which did not contain additives.

[0242] In addition, the present application also provides the liquid crystal compositions of the following Examples 12-18.

[0243] Example 12

[0244] A liquid crystal composition, which differs from Example 11 only in that: in the liquid crystal composition, the weight portion of additive 2 is 1 part; and the weight portions of additives 3 and 5 remain unchanged.

[0245] Example 13

[0246] A liquid crystal composition, which differs from Example 11 only in that: in the liquid crystal composition, the weight portion of additive 5 is 1 part; and the weight portions of additives 2 and 3 remain unchanged.

[0247] Example 14

[0248] A liquid crystal composition, which differs from Example 11 only in that: in the liquid crystal composition, the weight portion of additive 3 is 1 part; and the weight portions of additives 2 and 5 remain unchanged.

[0249] Example 15

[0250] A liquid crystal composition includes 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8) and 1 part by weight of an additive 6.

[0251] Example 16

[0252] A liquid crystal composition includes 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8) and 1 part by weight of an additive 4.

[0253] Example 17

[0254] A liquid crystal composition includes 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8), 0.5 parts by weight of additive 2, 0.5 parts by weight of additive 6, and 0.5 parts by weight of additive 3.

[0255] Example 18

[0256] A liquid crystal composition includes 100 parts by weight of a liquid crystal monomer (the formulation is the same as that of Example 8), 0.5 parts by weight of additive 2, 0.5 parts by weight of additive 6, and 0.5 parts by weight of additive 4.

[0257] The test results show that the ΔVHR of the liquid crystal cell samples made with the liquid crystal compositions of Examples 12-18 after being stored at 100° C. for 96 hours is less than 1.5%. In addition, the birefringence Δn of the liquid crystal compositions of Examples 12-18 is in the range of 0.34-0.36.

[0258] In addition, to highlight the beneficial effects of the embodiments of the present application, the present application also provides the following comparative examples 3-4.

[0259] Comparative Example 3

[0260] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0261] Compound of formula (I-1) (abbreviated as 3PTP1): 12 wt%;

[0262] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 15 wt%;

[0263] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 10 wt%;

[0264] Compound of formula (III-A-2) (abbreviated as 3PPTUI4): 6 wt%;

[0265] Compound of formula (III-B-1) (abbreviated as 5GPTUF): 8 wt%;

[0266] Compound of formula (III-B-2) (abbreviated as 3GPTUF): 9 wt%;

[0267] Compound of formula (III-B-3) (abbreviated as 3GPTGF): 8 wt%;

[0268] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 12 wt%;

[0269] Compound of formula (III-C-2) (abbreviated as 3PTGGF): 10 wt%;

[0270] Compound of formula (III-C-3) (abbreviated as 3PTGUF): 10 wt%.

[0271] The main difference between the liquid crystal monomer composition of Comparative Example 3 and that of Example 5 is that the liquid crystal monomer does not contain the compound of formula (II) but contains the compound of formula (I-1).

[0272] Comparative Example 4

[0273] A liquid crystal composition comprising 100 parts by weight of a liquid crystal monomer and 1 part by weight of an additive (same as in Example 1); wherein the liquid crystal monomer comprises the following compounds in the following weight percentages:

[0274] Compound of formula (I-2) (abbreviated as 3PTPO(2)): 12 wt%;

[0275] Liquid crystal compound 3PTPTP2: 12 wt%;

[0276] Liquid crystal compound 5PTPTP2: 13 wt%;

[0277] Compound of formula (III-A-1) (abbreviated as 3PPTUI2): 16 wt%;

[0278] Compound of formula (III-C-1) (abbreviated as 2PTGGF): 16 wt%;

[0279] Compound of formula (III-C-2) (abbreviated as 3PTGGF): 15 wt%;

[0280] Compound of formula (III-C-3) (abbreviated as 3PTGUF): 16 wt%.

[0281] The main difference between the liquid crystal monomer composition of Comparative Example 4 and that of Example 4 is that the liquid crystal monomer composition does not contain the compound of formula (II) of the present application, but contains the compounds 3PTPTP2 and 5PTPTP2 that do not conform to formula (II) of the present application.

[0282] The results showed that the birefringence Δn of the liquid crystal composition of Comparative Example 3 was 0.313, which is lower than the high level of 0.32 or above achieved by the liquid crystal compositions of the examples of the present application. After the liquid crystal composition of Comparative Example 4 was poured into a liquid crystal cell and stored at a low temperature of -20°C for 500 hours, colorful patterns were observed in the cell. This indicates that the liquid crystal composition of Comparative Example 4 has poor low-temperature resistance. This also reflects that liquid crystal compositions containing the compound represented by formula (I), the compound represented by formula (II), and the compound represented by formula (III) of the present application can have a high birefringence and low-temperature resistance.

[0283] The foregoing merely represents exemplary embodiments of the present application, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0284] It should be noted that the words "first", "second", etc. used in this application are used to distinguish different objects, rather than to describe a specific order. The words "set", "connect", and "install" in this application should be understood in a broad sense. For example, they can be directly set, connected, or installed, or they can be indirectly set, connected, or installed through an intermediate medium. The directional terms mentioned in this application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "front", "back", "bottom", "top", etc., are only for better and clearer explanation and understanding of this application, and do not indicate or imply that the referred components must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on this application.

[0285] In the description of this application, unless otherwise specified, the meaning of "multiple (kinds)" refers to greater than or equal to two (kinds). "At least one (kind)" refers to one (kind) or more (kinds). "At least one of the following (kinds)" or similar expressions refers to any combination of these items, including any combination of single (individual) or plural (individual) items. For example, "at least one (individual) of a, b, or c", or "at least one (individual) of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple, respectively.

[0286] In addition, the numerical range indicated by "-" in this application refers to the range including the values ​​before and after the "-" as the minimum and maximum values, respectively. In this application, expressions about parameter ranges, such as "greater than or equal to (≥)", "less than or equal to (≤)", "above...", and "below...", all include the number itself.

Claims

1. A liquid crystal composition, characterized in that The liquid crystal composition includes at least one first compound represented by formula (I), at least one second compound represented by formula (II), at least one third compound represented by formula (III), and additives: Among them, R a 、R b Each occurrence is independently selected from one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkenyloxy, substituted or unsubstituted alkynyl, substituted or unsubstituted alkynyloxy, and substituted or unsubstituted cycloalkyl; R c One selected from the group consisting of a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkenyloxy group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyloxy group, and a substituted or unsubstituted cycloalkyl group; Z1 and Z2 are independently selected from -CH=CH-, -CF=CF-, -CH=CF-, -CF=CH-, -CH2-CH2-, -CF2-CF2-, -CF2-CH2-, -CH2-CF2-, -CH2-O-, -O-CH2-, -CF2O-, -OCF2-, -CO-O-, -O-CO-, -N=N-, -CH=N-, -N=CH-, -C≡C-, -C≡CC≡C-, or a direct bond, but are not both -C≡C- or a direct bond; R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 Each occurrence is independently selected from one of hydrogen atom, deuterium atom, tritium atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, unsubstituted cycloalkyl group, and in the formula (I), the formula (II) and the formula (III), R 8 With R 9 At least one of them is a hydrogen atom; X is selected from a halogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted alkoxy group.

2. The liquid crystal composition according to claim 1, wherein In formula (III), Z1 is -C≡C-, and Z2 is a direct bond; or, Z1 is a direct bond, and Z2 is -C≡C-.

3. The liquid crystal composition according to claim 1 or 2, wherein The substituents in the substituted alkyl, substituted alkoxy, substituted alkenyl, substituted alkenyloxy, substituted alkynyl, and substituted alkynyloxy include one or more of a deuterium atom, a tritium atom, and a halogen atom; the substituents in the substituted cycloalkyl include one or more of a halogen atom, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkenyloxy, a substituted or unsubstituted alkynyl, a substituted or unsubstituted alkynyloxy, and a substituted or unsubstituted cycloalkyl.

4. The liquid crystal composition according to any one of claims 1 to 3, wherein The substituted or unsubstituted alkyl group is a substituted or unsubstituted C1 to C 20 Alkyl; the substituted or unsubstituted alkoxy is a substituted or unsubstituted C1~C 20 Alkoxy; the substituted or unsubstituted alkenyl is a substituted or unsubstituted C2~C 20 Alkenyl; the substituted or unsubstituted alkenyloxy is a substituted or unsubstituted C2~C 20 Alkenyloxy; the substituted or unsubstituted alkynyl is a substituted or unsubstituted C2~C 20 Alkynyl; the substituted or unsubstituted alkynyloxy group is a substituted or unsubstituted C2~C 20 Alkynyloxy; the substituted or unsubstituted cycloalkyl is a substituted or unsubstituted C3~C 20 Cycloalkyl.

5. The liquid crystal composition according to any one of claims 1 to 4, wherein The X, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9 wherein the substituted or unsubstituted alkyl group is a fluorinated or unsubstituted C1 to C8 alkyl group; the substituted or unsubstituted alkoxy group is a fluorinated or unsubstituted C1 to C8 alkoxy group; the unsubstituted cycloalkyl group is an unsubstituted C3 to C 10 Cycloalkyl.

6. The liquid crystal composition according to any one of claims 1 to 5, wherein In the formula (I), the formula (II) and the formula (III), the R 6 With the R 7 At least one of them is an H atom; in the formula (II) and the formula (III), R 4 With R 5 At least one of them is a hydrogen atom.

7. The liquid crystal composition according to any one of claims 1 to 6, wherein In the liquid crystal composition, the mass percentage of the first compound is 1%-70%, the mass percentage of the second compound is 1%-70%, and the mass percentage of the third compound is 1%-70%.

8. The liquid crystal composition according to claim 7, wherein In the liquid crystal composition, the mass percentage of the first compound is 1-20%, the mass percentage of the second compound is 15%-50%, and the mass percentage of the third compound is 40%-65%.

9. The liquid crystal composition according to any one of claims 1 to 8, wherein In the formula (I), R 1 、R 6 、R 7 、R 8 、R 9 All are hydrogen atoms.

10. The liquid crystal composition according to any one of claims 1 to 9, wherein In the formula (II), R 4 、R 5 、R 6 、R 7 、R 8 、R 9 All are hydrogen atoms.

11. The liquid crystal composition according to any one of claims 1 to 10, wherein The at least one third compound includes one or more of the following: Among them, the R 1 、The R 3 Each occurrence is independently selected from one of hydrogen atom, fluorine atom, fluorinated or unsubstituted alkyl, fluorinated or unsubstituted alkoxy; said R 8 Each occurrence is independently selected from a hydrogen atom or a fluorine atom; said R c One selected from substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, and unsubstituted cycloalkyl.

12. The liquid crystal composition according to claim 11, wherein The at least one third compound includes one or more of the substance represented by formula (III-B) and the substance represented by formula (III-C), as well as the substance represented by formula (III-A).

13. The liquid crystal composition according to claim 11 or 12, wherein The mass percentages of the substance represented by formula (III-A), the substance represented by formula (III-B), and the substance represented by formula (III-C) in the liquid crystal composition are independently less than or equal to 50%.

14. The liquid crystal composition according to any one of claims 11 to 13, wherein: In the liquid crystal composition, the mass percentage of the substance represented by formula (III-A) is in the range of 14%-30%, the mass percentage of the substance represented by formula (III-B) is in the range of 0%-32%, and the mass percentage of the substance represented by formula (III-C) is in the range of 8%-46%.

15. The liquid crystal composition according to any one of claims 1 to 14, wherein The liquid crystal composition further comprises a substance represented by the following formula (IV): Among them, R 9 、R 10 They are independently selected from one of a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted alkoxy group.

16. The liquid crystal composition according to any one of claims 1 to 15, wherein The additives include one or more of hindered phenol additives, hindered amine additives, and benzotriazole additives.

17. The liquid crystal composition according to any one of claims 1 to 16, wherein: The mass percentage of the additive in the liquid crystal composition is less than or equal to 5%.

18. The liquid crystal composition according to claim 16, wherein The hindered amine additive includes the general formula shown in the following formula (V): Wherein, each occurrence of R is independently selected from hydrogen, oxygen or C1-C4 alkyl; Y is selected from a straight-chain alkylene group having 3-10 carbon atoms.

19. The liquid crystal composition according to claim 16, wherein The benzotriazole additive includes one or more of the following general formulas: wherein Y1 is selected from a hydrogen atom or a halogen atom, and Y2 is independently selected from a hydrogen atom, a C1 to C2 substituted or unsubstituted halogen atom, 20 Alkyl, Y3, Y4, Y5 are independently selected from C1 to C1 substituted or unsubstituted by one or more halogen atoms or ester groups 20 alkyl.

20. The liquid crystal composition according to any one of claims 1 to 19, wherein The birefringence of the liquid crystal composition is within the range of 0.32-0.42, the clearing point of the liquid crystal composition is within the range of 100-140° C., and the liquid crystal composition has no abnormality after being stored at −20° C. for 500 hours.

21. Use of the liquid crystal composition according to any one of claims 1 to 20 in a liquid crystal device.

22. A liquid crystal device, characterized in that: The liquid crystal device comprises a liquid crystal layer, and the liquid crystal layer comprises the liquid crystal composition according to any one of claims 1 to 20.

23. The liquid crystal device according to claim 22, wherein The liquid crystal device comprises a cover substrate, a transparent electrode layer, a first alignment layer, the liquid crystal layer, a second alignment layer, a passivation layer, a back plate electrode layer and a silicon substrate which are stacked in sequence.

24. A device, characterized in that The apparatus comprises the liquid crystal device according to claim 22.

25. The liquid crystal device according to claim 24, wherein The device includes one or more of a wavelength selective switch, a microwave scanning antenna, a liquid crystal optical antenna, a liquid crystal optical waveguide, a variable focus lens device, a liquid crystal prism, a grating, a lidar, a beam tracker, a projector, an optical projection system, a flat panel display, a holographic display, an image acquisition device, an optical communication device, and a wireless communication device.

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