Liquid crystal composition with positive dielectric anisotropy and application thereof

Abstract

The invention relates to a liquid crystal composition with positive dielectric anisotropy and application thereof, and belongs to the technical field of liquid crystal materials. The liquid crystal composition comprises the following components in percentage by mass: 20-70% of at least one or more than two compounds as shown in a general formula I, 5-30% of # imgabs0 #, 2-35% of at least one or more than two compounds as shown in a general formula II, 0-25% of at least one or more than two compounds as shown in a general formula III, 0-25% of # imgabs2 # and at least one or more than two compounds as shown in a general formula IV, 0%-25% of at least one or more compounds as shown in a general formula V: 0%-18% of at least one or more compounds as shown in a general formula VI: # imgabs5. The liquid crystal composition provided by the invention is used for a liquid crystal display device, so that low-voltage driving can be realized, more energy consumption is saved, and the transmittance of the liquid crystal display device is improved.

Description

Technical Field

[0001] The present invention relates to a liquid crystal material and its application, and particularly to a liquid crystal composition with positive dielectric anisotropy and its application. This liquid crystal material has a high clearing point, a large birefringence, and a large dielectric anisotropy, and it can be well applied to devices such as LCOS, dimming glass, filters, and vehicle-mounted systems. It belongs to the technical field of liquid crystal materials. Background Art

[0002] With the progress of display technology and the improvement of people's living standards, people have higher requirements for display quality and display experience. At the same time, in order to meet the requirements of modern society for environmental protection, it is very necessary to reduce power consumption and save electricity.

[0003] If a liquid crystal display is to reduce power consumption, the liquid crystal material used should have a lower threshold voltage to achieve the purpose of low-voltage driving and reducing power consumption. This requires the liquid crystal material to have a larger dielectric anisotropy and an appropriate optical anisotropy; at the same time, there is a positive correlation between ε⊥ and transmittance, and a large ε⊥ is beneficial to improving the light transmittance. High light transmittance can reduce the backlight intensity of the liquid crystal display, thereby achieving the purpose of saving energy consumption and extending the service life of the device.

[0004] In practical applications, it is impossible to meet the above conditions through a single compound. Therefore, it is usually achieved by combining several compounds, and the selection and ratio of different liquid crystal compounds directly affect the performance of the liquid crystal material.

[0005] The liquid crystal composition provided by this application is applicable to fields such as LCOS, filters, and vehicle-mounted systems. It has a large dielectric anisotropy, can achieve low-voltage driving, making the device more energy-saving. At the same time, this composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device. Summary of the Invention

[0006] In order to meet the requirements of modern society for environmental protection, reduce power consumption, and save electricity, the present invention provides a positive liquid crystal composition, which can enable the liquid crystal display device to achieve low-voltage driving and be more energy-saving.

[0007] The liquid crystal composition of the present invention has a high clearing point, a large birefringence, and a large dielectric anisotropy. In particular, the large dielectric anisotropy is beneficial to reducing the driving voltage, thereby making the liquid crystal device more energy-efficient; at the same time, this composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A liquid crystal composition with positive dielectric anisotropy, by mass percentage, comprises the following components:

[0010] (1) It contains at least one or two or more compounds with the structure shown in General Formula I, with a mass fraction of 20% - 70%. The specific structure of General Formula I is:

[0011]

[0012] In the above formula, R 1 and R 2 are the same or different and each independently represents an alkyl group of C 1 -C 10 , an alkoxy group of C 1 -C 10 or is substituted with -F;

[0013] X 1 , X 2 , X 3 each independently represents -H, -F, -CF 3 or -OCF 3 ;

[0014] Ring represents:

[0015] Ring represents:

[0016] (2) It contains at least one or two or more compounds with the structure shown in General Formula II, with a mass fraction of 5% - 30%. The structural formula of General Formula II is:

[0017]

[0018] In the above formula, R 3 and R 4 are the same or different and each independently represents an alkyl group of C 1 -C 10 or is substituted with -F;

[0019] Ring and Ring are the same or different and each independently represents: One or more H on the benzene ring can be substituted with F;

[0020] (3) It contains at least one or two or more compounds with the structure shown in General Formula III, with a mass percentage of 2% - 35%. The specific structure of General Formula III is:

[0021]

[0022] In the above formula, R 5 , R 6 each independently represents C 1 -C10 linear alkyl group, C 1 ~C 10 linear alkoxy group or C 2 ~C 10 linear alkenyl group;

[0023] ring and ring each independently represents trans-1,4-cyclohexylene or 1,4-phenylene;

[0024] (4) contains at least one or two or more compounds having the structure shown in general formula Ⅳ, with a mass percentage of 0%-25%. The specific structure of general formula Ⅳ is:

[0025]

[0026] In the above formula, R 7 represents C 1 ~C 10 linear alkyl group or C 1 ~C 10 linear alkoxy group; X 4 represents -H or -F; n 1 represents 0 or 1;

[0027] ring represents:

[0028] (5) contains at least one or two or more compounds having the structure shown in general formula Ⅴ, with a mass percentage of 0%-25%. The specific structure of general formula Ⅴ is:

[0029]

[0030] In the above formula, R 8 、R 9 each independently represents C 1 ~C 10 linear alkyl group, C 1 ~C 10 linear alkoxy group, -F or -CN; X 5 、X 6 represents -H or -F; n 2 represents 0 or 1;

[0031] ring represents:

[0032] (6) contains at least one or two or more compounds having the structure shown in general formula Ⅵ, with a mass percentage of 0%-18%. The specific structure of general formula Ⅵ is:

[0033]

[0034] In the above formula, R 10 and R 11 each independently represent a straight-chain alkyl group of C 1 to C 10 ;

[0035] The sum of the masses of the compounds represented by General Formula I, General Formula II, General Formula III, General Formula IV, General Formula V, and General Formula VI is 100%.

[0036] Preferably, in the liquid crystal composition, it contains at least one compound represented by General Formula IV, General Formula V, and / or General Formula VI, that is, the mass percentages of the compounds represented by General Formula IV, General Formula V, and General Formula VI cannot be 0 at the same time. Among them, the mass percentage of the compound represented by General Formula IV is 0.5% - 25%; the mass percentage of the compound represented by General Formula V is 0.5% - 25%; the mass percentage of the compound represented by General Formula VI is 0.5% - 18%.

[0037] Preferably, in the liquid crystal composition, it contains at least one compound represented by General Formula IV and at least one compound represented by General Formula V, or at least one compound represented by General Formula IV and at least one compound represented by General Formula VI, at least one compound represented by General Formula V and at least one compound represented by General Formula VI; among them, the mass percentage of the compound represented by General Formula IV is 0.5% - 25%; the mass percentage of the compound represented by General Formula V is 0.5% - 25%; the mass percentage of the compound represented by General Formula VI is 0.5% - 18%.

[0038] Preferably, in the liquid crystal composition, the lower limit of the mass percentages of the compounds of General Formula IV, General Formula V, and VI is 0.5%, preferably 1%, more preferably 3% or 5%.

[0039] Preferably, the compound represented by General Formula I is selected from one or more of the following Compounds I-1 to I-38:

[0040]

[0041]

[0042]

[0043]

[0044] More preferably, the compound represented by General Formula I is selected from one or more of Compounds I-1, I-3, I-10, I-14, I-18, I-22, I-26, I-27, I-28, I-30, and I-34.

[0045] In the described liquid crystal composition, the mass percentage of the compound of general formula I is 20% to 70%, preferably 25% to 67%; more preferably 30% to 65%, 32% to 64%.

[0046] Preferably, the compound represented by general formula II is selected from one or more of the following compounds II-1 to II-17:

[0047]

[0048]

[0049] More preferably, the compound represented by general formula II is selected from one or more of compounds II-6, II-8 and II-17.

[0050] In the described liquid crystal composition, the mass percentage of the compound of general formula II is 5% to 30%, preferably 8% to 28%; more preferably 10% to 25%, 11% to 24%.

[0051] Preferably, the compound represented by general formula III is selected from one or more of the following compounds III-1 to III-19:

[0052]

[0053]

[0054] More preferably, the compound represented by general formula III is selected from one or two of compounds III-5 and III-19.

[0055] In the described liquid crystal composition, the mass percentage of the compound of general formula III is 2% to 35%, preferably 4% to 32%; more preferably 6% to 30%, 6% to 29%.

[0056] Preferably, the compound represented by general formula IV is selected from one or more of the following compounds IV-1 to IV-23:

[0057]

[0058]

[0059]

[0060] More preferably, the compound represented by general formula IV is selected from one or more of compounds IV-1, IV-2, IV-9 and IV-17.

[0061] In the described liquid crystal composition, the lower limit of the mass percentage of the compound of general formula IV can be 0%, 0.5%, 1%, 3% or 5%, and the upper limit of the mass percentage can be 25%, 23%, 21% or 20%.

[0062] In the described liquid crystal composition, the mass percentage of the compound of general formula IV is 0% - 25%, preferably 0% - 23%; more preferably 0% - 21%, 0% - 20%.

[0063] Preferably, the compound represented by general formula V is selected from one or more of the following compounds V-1 to V-41:

[0064]

[0065]

[0066]

[0067]

[0068] More preferably, the compound represented by general formula V is selected from one or more of compounds V-1, V-10, V-11 and V-23.

[0069] In the described liquid crystal composition, the lower limit of the mass percentage of the compound of general formula V can be 0%, 0.5%, 1%, 3% or 5%, and the upper limit of the mass percentage can be 25%, 23%, 21% or 20%.

[0070] In the described liquid crystal composition, the mass percentage of the compound of general formula V is 0% - 25%, preferably 0% - 23%, more preferably 0% - 21%, 0% - 20%.

[0071] Preferably, the compound represented by general formula VI is selected from one or more of the following compounds VI-1 to VI-4:

[0072]

[0073] More preferably, the compound represented by general formula VI is selected from one or two of compounds VI-2 and VI-4.

[0074] In the described liquid crystal composition, the lower limit of the mass percentage of the compound of general formula VI can be 0%, 0.5%, 1%, 3% or 5%, and the upper limit of the mass percentage can be 18%, 16%, 15% or 14%.

[0075] In the described liquid crystal composition, the mass percentage of the compound of general formula VI is 0% - 18%, preferably 0% - 16%, more preferably 0% - 15%, 0% - 14%.

[0076] Preferably, the liquid crystal composition comprises the following components in mass percentages:

[0077] (1) 25-67% of the compound represented by the general formula I;

[0078] (2) 8-28% of the compound represented by the general formula II;

[0079] (3) 4-32% of the compound represented by the general formula III;

[0080] (4) 0-23% of the compound represented by the general formula IV;

[0081] (5) 0-23% of the compound represented by the general formula V;

[0082] (6) 0-16% of the compound represented by the general formula VI.

[0083] More preferably, the liquid crystal composition comprises the following components in mass percentages:

[0084] (1) 30-65% of the compound represented by the general formula I;

[0085] (2) 10-25% of the compound represented by the general formula II;

[0086] (3) 6-30% of the compound represented by the general formula III;

[0087] (4) 0-21% of the compound represented by the general formula IV;

[0088] (5) 0-21% of the compound represented by the general formula V;

[0089] (6) 0-15% of the compound represented by the general formula VI.

[0090] Still more preferably, the liquid crystal composition comprises the following components in mass percentages:

[0091] (1) 32-64% of the compound represented by the general formula I;

[0092] (2) 11-24% of the compound represented by the general formula II;

[0093] (3) 6-29% of the compound represented by the general formula III;

[0094] (4) 0-20% of the compound represented by the general formula IV;

[0095] (5) 0-20% of the compound represented by the general formula V;

[0096] (6) 0-14% of the compound represented by the general formula VI.

[0097] The liquid crystal composition of the present invention has the characteristics of large birefringence, high clearing point, and large dielectric anisotropy, and can be applied to fields such as LCOS, filters, dimming glass, and vehicle-mounted systems. The liquid crystal composition provided by the present invention enables the liquid crystal display device to achieve low-voltage driving, which is more energy-saving. At the same time, the composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device.

[0098] Advantages of the present invention:

[0099] The liquid crystal composition provided by the present invention enables the liquid crystal display device to achieve low-voltage driving, which is more energy-saving. At the same time, the composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device.

[0100] The liquid crystal composition provided by the present invention has a high clearing point, large birefringence, and large dielectric anisotropy. In particular, the large dielectric anisotropy is beneficial to reducing the driving voltage, thereby making the liquid crystal device more energy-saving; at the same time, the composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device.

[0101] The liquid crystal composition provided by the present invention has a high clearing point, large birefringence, and large dielectric anisotropy, and can be applied to devices such as LCOS, dimming glass, filters, and vehicle-mounted systems. The large dielectric anisotropy is beneficial to reducing the driving voltage, thereby making the liquid crystal device more energy-saving; the large ε⊥ can improve the transmittance of the liquid crystal display device. Detailed implementation manners

[0102] The abbreviated codes for the test items in the following examples are as follows:

[0103] Tni: Clearing point;

[0104] no: Refractive index of ordinary light (589 nm, 25 °C);

[0105] ne: Refractive index of extraordinary light (589 nm, 25 °C);

[0106] Δn: Refractive index anisotropy (589 nm, 25 °C);

[0107] Δε: Dielectric anisotropy (1 kHz, 25 °C);

[0108] Among them, Δε = ε∥ - ε⊥, where ε∥ is the dielectric constant parallel to the molecular axis, and ε⊥ is the dielectric constant perpendicular to the molecular axis. The test conditions are: 25 °C, 1 kHz.

[0109] In the following examples, the group structures in the liquid crystal compounds are represented by the codes shown in Table 1.

[0110] Table 1 Codes for functional groups of liquid crystal compounds

[0111]

[0112] Taking the following compound structure as an example:

[0113]

[0114] Functional group code representation: 3UTPP2

[0115]

[0116] Functional group code representation: 5CPEGN

[0117]

[0118] Functional group code representation: 3APUQUF

[0119] Weigh the compounds with the corresponding general formula structures according to the mass percentages in the examples. Place the weighed monomers in a hard high-borosilicate glass bottle. Under nitrogen protection, heat up and stir magnetically or mechanically until a molten, clear, homogeneous, and transparent solution is formed. Then continue stirring for 30 minutes to thoroughly and evenly mix the materials, and then stop heating. Carry out degassing under reduced pressure while stirring; as the temperature decreases, the vacuum degree is increased until the temperature cools to room temperature, then stop stirring and continue evacuating until no bubbles are seen. Then it can be poured into the test box for testing.

[0120] Taking Example 6 as an example below, the preparation method of the liquid crystal compound in the embodiment of the present invention is described. The preparation steps of other examples are the same as this.

[0121] Weigh 9% of the compound of general formula I-1, 8% of the compound of general formula I-10, 6% of the compound of general formula I-14, 15.5% of the compound of general formula I-22, 5% of the compound of general formula I-26, 5% of the compound of general formula I-27, 5% of the compound of general formula I-28, 2% of the compound of general formula I-30, 2.5% of the compound of general formula I-34, 11% of the compound of general formula II-6, 6% of the compound of general formula II-8, 3% of the compound of general formula II-17, 9% of the compound of general formula III-5, and 13% of the compound of general formula IV-1 according to the mass percentages in Example 6. Place the above-mentioned weighed monomers in a hard high-borosilicate glass bottle. Under nitrogen protection, heat up and stir magnetically or mechanically until a molten, clear, homogeneous, and transparent solution is formed. Then continue stirring for 30 minutes to thoroughly and evenly mix the materials, and then stop heating. Carry out degassing under reduced pressure while stirring; as the temperature decreases, the vacuum degree is increased until the temperature cools to room temperature, then stop stirring and continue evacuating until no bubbles are seen. Then it can be poured into the test box for testing.

[0122] Table 2 Composition and test data of the liquid crystal composition in Example 1

[0123]

[0124]

[0125] Table 3 Composition and Test Data of the Liquid Crystal Composition in Example 2

[0126]

[0127] Table 4 Composition and Test Data of the Liquid Crystal Composition in Example 3

[0128]

[0129]

[0130] Table 5 Composition and Test Data of the Liquid Crystal Composition in Example 4

[0131]

[0132] Table 6 Composition and Test Data of the Liquid Crystal Composition in Example 5

[0133]

[0134] Table 7 Composition and Test Data of the Liquid Crystal Composition in Example 6

[0135]

[0136]

[0137] Table 8 Composition and Test Data of the Liquid Crystal Composition in Example 7

[0138]

[0139]

[0140] Table 9 Composition and Test Data of the Liquid Crystal Composition in Example 8

[0141]

[0142] As can be seen from the above examples, the liquid crystal composition provided by the present invention has a high clearing point, a large birefringence, and a large dielectric anisotropy, and can be applied to devices such as LCOS, dimming glass, filters, and vehicle-mounted systems. In particular, the large dielectric anisotropy is beneficial to reducing the driving voltage, thereby making the liquid crystal device more energy-efficient; at the same time, the composition has a large ε⊥, which can improve the transmittance of the liquid crystal display device.

Claims

1. A liquid crystal composition with positive dielectric anisotropy, characterized in that: According to mass percentage, it includes the following components: (1) A compound containing at least one or two or more compounds of the structure represented by general formula I, with a mass fraction of 20% to 70%, wherein general formula I is: In the formula, R1 and R2 each independently represent C1~C 10 Alkyl, C1~C 10 Alkoxy or -F; X1, X2, X3 each independently represent -H, -F, -CF3 or -OCF3; ring express: ring express: (2) A compound containing at least one or two or more compounds of the structure represented by general formula II, with a mass fraction of 5% to 30%, wherein general formula II is: In the formula, R3 and R4 each independently represent C1~C 10 Alkyl or -F; ring and ring Independent Representatives: wherein one or more H on the benzene ring may be replaced by F; (3) A compound containing at least one or two or more structures represented by general formula III, with a mass percentage of 2% to 35%, wherein general formula III is: In the formula, R5 and R6 each independently represent C1~C 10 Straight chain alkyl, C1~C 10 Straight chain alkoxy or C2~C 10 Straight chain alkenyl; ring and ring Each independently represents a trans-1,4-cyclohexylene or a 1,4-phenylene; (4) A compound containing at least one or two or more compounds of the structure represented by general formula IV, with a mass percentage of 0% to 25%, wherein general formula IV is: In the formula, R7 represents C1~C 10 Straight chain alkyl or C1~C 10 A straight-chain alkoxy group; X4 represents -H or -F; n1 represents 0 or 1; a ring express: (5) A compound comprising at least one or two or more compounds of the structure represented by general formula V, with a mass percentage of 0% to 25%, wherein general formula V is: In the formula, R8 and R9 each independently represent C1 to C 10 Straight chain alkyl, C1~C 10 straight chain alkoxy, -F or -CN; X5, X6 represent -H or -F; n2 represents 0 or 1; express: (6) A compound containing at least one or two or more compounds of the structure represented by the general formula VI, with a mass percentage of 0% to 18%, wherein the general formula VI is: In the formula, R 10 , R 11 Each independently represents C1~C 10 of a straight chain alkyl group.

2. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The liquid crystal composition comprises at least one compound having a structure represented by general formula IV, general formula V and / or general formula VI, wherein the mass percentage of the compound having a structure represented by general formula IV is 0.5%-25%; the mass percentage of the compound having a structure represented by general formula V is 0.5%-25%; and the mass percentage of the compound having a structure represented by general formula VI is 0.5%-18%.

3. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The liquid crystal composition comprises at least one compound having a structure represented by general formula IV and at least one compound having a structure represented by general formula V, or at least one compound having a structure represented by general formula IV and at least one compound having a structure represented by general formula VI, or at least one compound having a structure represented by general formula V and at least one compound having a structure represented by general formula VI; the mass percentage of the compound having a structure represented by general formula IV is 0.5%-25%; the mass percentage of the compound having a structure represented by general formula V is 0.5%-25%; and the mass percentage of the compound having a structure represented by general formula VI is 0.5%-18%.

4. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula I is selected from one or more of compounds I-1 to I-38:

5. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula II is selected from one or more of compounds II-1 to II-17:

6. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula III is selected from one or more of compounds III-1 to III-19:

7. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula IV is selected from one or more of compounds IV-1 to IV-23:

8. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula V is selected from one or more of compounds V-1 to V-41:

9. The liquid crystal composition with positive dielectric anisotropy according to claim 1, characterized in that: The compound represented by general formula VI is selected from one or more of compounds VI-1 to VI-4:

10. Use of the liquid crystal composition with positive dielectric anisotropy according to any one of claims 1 to 9 in LCOS, filters, dimming glass and vehicle-mounted systems.

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