Positive and negative mixed liquid crystal composition and application thereof

Abstract

The invention relates to a positive and negative mixed liquid crystal composition 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: (1) one or more structural compounds as shown in a general formula A, (2) one or more structural compounds as shown in a general formula B, (3) one or more compounds as shown in a general formula C, (4) one or more compounds as shown in a general formula D, and (5) one or more compounds as shown in a general formula E, the positive and negative mixed liquid crystal composition has low rotational viscosity and high elastic constant, can effectively improve the liquid crystal contrast ratio and response speed, has good low-temperature storage performance, is excellent in performance, can be used for preparing a liquid crystal display device, and can be widely applied to the field of liquid crystal display devices, such as liquid crystal display devices, liquid crystal display devices, liquid crystal display devices, liquid crystal display devices, liquid crystal display devices, liquid crystal display devices, liquid crystal display devices, liquid crystal display devices and liquid crystal display devices. The display panel can be well applied to IPS and FFS display modes.

Description

Technical Field

[0001] This invention relates to a positive and negative mixed liquid crystal composition and its application, belonging to the field of liquid crystal material technology. Background Technology

[0002] In recent years, with the widespread use of TFT LCDs, the performance requirements for them have been continuously increasing. High display image quality requires faster response times, lower power consumption, and higher low-temperature reliability. In addition, higher contrast ratios and higher transmittance are also required, especially for IPS and FFS display modes. This means that liquid crystal materials need to have higher transmittance, higher elastic constants, faster response times, and lower low-temperature reliability.

[0003] The planar arrangement of IPS and FFS liquid crystals makes them prone to light leakage in the dark, resulting in lower contrast compared to VA-type (MVA, PVA, UV2A, PSVA) displays. Research has found that increasing the elastic constant of liquid crystals helps improve the alignment of liquid crystal molecules, thereby improving the contrast of IPS and FFS mode displays.

[0004] Specifically, for IPS and FFS mode displays, increasing the ε⊥ / |Δε| (the ratio of the absolute value of the vertical dielectric to the absolute value of the dielectric constant) of the liquid crystal composition can effectively improve the transmittance of the liquid crystal display, while low rotational viscosity and high elastic constant can effectively improve the contrast and response speed of the liquid crystal display.

[0005] In practical applications, it is impossible to achieve the above conditions with a single compound. Usually, multiple compounds are combined to achieve this. The selection and ratio of different liquid crystal compounds have a direct impact on the performance of liquid crystal materials. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a positive and negative mixed liquid crystal composition containing a naphthalene ring and its applications. In the liquid crystal composition provided by this invention, the compounds represented by general formulas A, C, D, and F are positive liquid crystal compounds, possessing large dielectric anisotropy and a large K value; the compound represented by general formula E is a negative liquid crystal compound, possessing a large perpendicular dielectric and negative dielectric anisotropy. Combining positive and negative liquid crystal compounds to form a high-performance liquid crystal composition allows it to possess the advantages of fast response of positive liquid crystals while simultaneously achieving an effective increase in transmittance, thereby significantly reducing the overall power consumption of liquid crystal display devices.

[0007] The liquid crystal composition provided by this invention has a large ε⊥, and ε⊥ is positively correlated with transmittance. A large ε⊥ is beneficial to improving light transmittance. High light transmittance can reduce the backlight intensity of the liquid crystal display, thereby saving energy and extending the service life of the device. At the same time, it has a low rotational viscosity and a high elastic constant, which enables the display device to have a faster response speed and a higher contrast.

[0008] The naphthalene ring-containing positive and negative mixed liquid crystal composition provided by the present invention has a large vertical dielectric, which can effectively improve the transmittance of liquid crystal. It has low rotational viscosity and high elastic constant, which can effectively improve the response time and contrast of liquid crystal. It also has good low-temperature storage performance. Its excellent performance makes it well applicable to display modes such as IPS and FFS.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A positive and negative mixed liquid crystal composition, comprising the following components by weight percentage:

[0011] (1) Contains at least one or more compounds with the structure shown in general formula A, with a mass fraction of 1%-20%, wherein the specific structure of general formula A is:

[0012]

[0013] In the above formula, R1 represents a straight-chain alkyl or alkoxy group with 1-5 carbon atoms, or an alkenyl group with 2-5 carbon atoms; n1 represents 0 or 1; X1, X2, and X3 each independently represent -H or -F.

[0014] ring Each independent expression

[0015] (2) Contains at least one or more compounds with the structure shown in general formula B, with a mass fraction of 30%-78%, wherein the specific structure of general formula B is:

[0016]

[0017] In the above formula, R2 and R3 each independently represent a straight-chain alkyl, straight-chain alkoxy or a chain alkenyl with carbon atoms 1-5, and n2 represents 0 or 1;

[0018] ring and Each independent expression

[0019] (3) A compound comprising at least one or more structures of general formula C, with a mass fraction of 0%-20%, wherein the general formula of general formula C is:

[0020]

[0021] In the above formula, R4 represents a straight-chain alkyl group with 1-5 carbon atoms, and n3 represents 0 or 1;

[0022] ring and The same or different, each represented independently:

[0023] (4) A compound comprising at least one or more structures of general formula D, in a mass percentage of 2%-40%, wherein the specific structure of general formula D is:

[0024]

[0025] In the above formula, R5 represents a straight-chain alkyl group with 1-5 carbon atoms;

[0026] ring The same or different, each represented independently:

[0027] (5) A compound comprising at least one or more structures of general formula E, in a mass percentage of 2%-28%, wherein the compound of general formula E is selected from compounds of general formula EⅠ and / or EⅡ, and the specific structures of the compounds of general formula EⅠ and EⅡ are as follows:

[0028]

[0029] In the above formula, R6 and R7 represent straight-chain alkyl groups with 1-5 carbon atoms; n4 represents 0 or 1.

[0030] ring The same or different, each represented independently:

[0031] Furthermore, the compound represented by general formula A is selected from one or more of the following compounds A-1 to A-96:

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula A is 1% to 20%, preferably 2% to 15%, and more preferably 3% to 10%.

[0038] Furthermore, the compound represented by general formula B is selected from one or more of the following compounds B-1 to B-56:

[0039]

[0040]

[0041] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula B is 30% to 78%, preferably 35% to 76%, and more preferably 40% to 74%.

[0042] Furthermore, the compound represented by general formula C is selected from one or more of the following compounds C-1 to C-25:

[0043]

[0044]

[0045]

[0046] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula C is 0% to 20%, preferably 0% to 15%, and more preferably 0% to 12%. When the mass percentage of the compound of general formula C is not 0, the minimum mass percentage of the compound of general formula C is ≥0.1%, preferably ≥0.5%, and more preferably ≥1%.

[0047] Furthermore, the compound represented by general formula D is selected from one or more of the following compounds D-1 to D-24:

[0048]

[0049]

[0050] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula D is 2% to 40%, preferably 3% to 35%, and more preferably 4% to 30%.

[0051] Furthermore, the compound represented by general formula E is selected from one or more of the following compounds: EⅠ-1 to EⅠ-16 and EⅡ-1 to EⅡ-4:

[0052]

[0053] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula E is 2% to 28%, preferably 5% to 23%, and more preferably 8% to 18%.

[0054] The liquid crystal composition of the present invention further comprises one or more compounds with the structure shown in general formula F, in a mass percentage of 0%-15%. The compounds with the structure shown in general formula F are selected from compounds with the structure shown in general formula FⅠ and / or FⅡ. The specific structures of the compounds shown in general formula FⅠ and FⅡ are as follows:

[0055]

[0056] In the above formula, R8 and R9 each independently represent straight-chain alkyl groups with 1-5 carbon atoms.

[0057] Furthermore, the compound represented by general formula F is selected from one or more of the following compounds: FⅠ-1 to FⅠ-5 and FⅡ-1 to FⅡ-4:

[0058]

[0059] In the liquid crystal composition of the present invention, the mass percentage of the compound of general formula F is 0% to 15%, preferably 0% to 13%, more preferably 0% to 10%; when the mass percentage of the compound of general formula F is not 0, the minimum mass percentage of the compound of general formula F is ≥0.1%, preferably ≥0.5%, more preferably ≥1%.

[0060] In the liquid crystal composition of the present invention, the sum of the masses of the compounds with structures shown in general formulas A, B, C, D, E and F is 100%.

[0061] A liquid crystal composition comprising the following components in weight percentage:

[0062] (1) 1-20% of the compounds represented by general formula A;

[0063] (2) 30-78% of the compounds represented by general formula B;

[0064] (3) Compounds represented by general formula C at 0-20%;

[0065] (4) 2-40% of compounds represented by general formula D;

[0066] (5) 2-28% of compounds represented by general formula E;

[0067] (6) Compounds represented by general formula F, ranging from 0% to 15%.

[0068] Preferably, a liquid crystal composition comprises the following components in weight percentage:

[0069] (1) 2-15% of the compounds represented by general formula A;

[0070] (2) 35-76% of the compounds represented by general formula B;

[0071] (3) Compounds represented by general formula C at 0-15%;

[0072] (4) 3-35% of compounds represented by general formula D;

[0073] (5) 5% to 23% of compounds represented by general formula E;

[0074] (6) Compounds represented by general formula F, accounting for 0-13%.

[0075] More preferably, a liquid crystal composition comprises the following components in weight percentage:

[0076] (1) 3-10% of the compounds represented by general formula A;

[0077] (2) 40-74% of the compounds represented by general formula B;

[0078] (3) Compounds represented by general formula C at 0-12%;

[0079] (4) 4% to 30% of the compounds represented by general formula D;

[0080] (5) 8-18% of compounds represented by general formula E;

[0081] (6) Compounds represented by general formula F at 0-10%.

[0082] The application of the liquid crystal composition of the present invention in the preparation of liquid crystal display devices can be used to prepare liquid crystal display devices comprising the liquid crystal composition of the present invention, wherein the liquid crystal display devices include liquid crystal display devices with display modes such as IPS and FFS.

[0083] The liquid crystal composition of the present invention has a large ε⊥, and ε⊥ is positively correlated with transmittance. A large ε⊥ is beneficial to improving light transmittance. High light transmittance can reduce the backlight intensity of the liquid crystal display, thereby saving energy and extending the service life of the device. At the same time, it has low rotational viscosity and high elastic constant, which enables the display device to have a faster response speed and higher contrast.

[0084] Advantages of this invention:

[0085] The positive and negative mixed liquid crystal composition with naphthalene ring of the present invention has a large vertical dielectric, and the transmittance T is proportional to ε⊥ / |Δε| (the ratio of the vertical dielectric to the absolute value of the dielectric constant). It can effectively improve the transmittance of liquid crystal and thus reduce energy consumption. It has low rotational viscosity and high elastic constant, which can enable display devices to have faster response speed and higher contrast. It also has good low temperature storage performance. Its excellent performance makes it well applicable to IPS and FFS display modes.

[0086] This invention relates to a naphthalene ring-containing positive and negative mixed liquid crystal composition, which exhibits a large vertical dielectric constant. The transmittance T is proportional to ε⊥ / |Δε| (the ratio of the absolute value of the vertical dielectric constant to the absolute value of the dielectric constant), effectively improving the transmittance of the liquid crystal and thus reducing energy consumption. It also possesses low rotational viscosity and a high elastic constant, and exhibits good low-temperature storage performance. The transmittance T is proportional to ε⊥ / |Δε|; the large vertical dielectric constant effectively improves the transmittance of the liquid crystal, thereby reducing energy consumption; and the low rotational viscosity and high elastic constant effectively improve the contrast ratio and response speed of the liquid crystal. Detailed Implementation

[0087] The abbreviated codes for the test items in the following examples are as follows:

[0088] Tni: Clear the bright spots;

[0089] no: Refractive index of ordinary light (589nm, 25℃);

[0090] ne: Refractive index of unusual light (589 nm, 25 °C);

[0091] Δn: Refractive index anisotropy (589 nm, 25 °C);

[0092] Δε: Dielectric anisotropy (1kHz, 25℃);

[0093] K11: Warp elastic constant;

[0094] K33: Bending elastic constant;

[0095] γ1: Rotational viscosity (mPa·s) at 25 degrees Celsius (°C);

[0096] Wherein, 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. Test conditions: 25℃, 1KHz.

[0097] For ease of explanation, in the following embodiments, the group structures of the liquid crystal compositions are represented by the codes listed in Table 1.

[0098] Table 1 Functional group codes of liquid crystal compounds

[0099]

[0100] Take the following compound structure as an example:

[0101]

[0102] Functional group code representation: 2CPUnF.

[0103]

[0104] Functional group code representation: V2CCP1.

[0105]

[0106] Functional group code representation: 3CC1OWO2.

[0107] According to the mass percentages in the examples, weigh the compounds of the corresponding general formula structures. Place the weighed monomers in a hard borosilicate glass bottle. Under nitrogen protection, heat the bottle and stir electromagnetically or mechanically until a clear, uniform, and transparent molten solution is formed. Continue stirring for another 30 minutes to ensure thorough and uniform mixing before stopping heating. Degas under reduced pressure while stirring; as the temperature decreases, the vacuum level increases until the temperature cools to room temperature. Stop stirring and continue evacuating until no more bubbles appear. The solution is then ready to be poured into a test kit for testing.

[0108] The following are some representative embodiments, but the present invention is not limited to these liquid crystal compositions.

[0109] Example 1: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 2.

[0110] Table 2 Composition and properties of the liquid crystal composition in Example 1

[0111]

[0112]

[0113] Example 2: A liquid crystal composition was prepared according to the method described above, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 3.

[0114] Table 3 Composition and properties of the liquid crystal composition in Example 2

[0115]

[0116]

[0117] Example 3: A liquid crystal composition was prepared according to the method described above, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 4.

[0118] Table 4. Composition and properties of the liquid crystal composition in Example 3

[0119]

[0120]

[0121] Example 4: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 5.

[0122] Table 5. Composition and properties of the liquid crystal composition in Example 4

[0123]

[0124]

[0125] Example 5: A liquid crystal composition was prepared according to the method described above, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 6.

[0126] Table 6. Composition and properties of the liquid crystal composition in Example 5

[0127]

[0128]

[0129] Example 6: A liquid crystal composition was prepared according to the method described above, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 7.

[0130] Table 7 Composition and properties of the liquid crystal composition in Example 6

[0131]

[0132]

[0133] Example 7: A liquid crystal composition was prepared according to the method described above, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 8.

[0134] Table 8 Composition and properties of the liquid crystal composition in Example 7

[0135]

[0136]

[0137] Example 8: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 9.

[0138] Table 9 Composition and properties of the liquid crystal composition in Example 8

[0139]

[0140]

[0141] Example 9: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 10.

[0142] Table 10 Composition and properties of the liquid crystal composition in Example 9

[0143]

[0144] Comparative Example 1: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 11.

[0145] Table 11 Composition and properties of the liquid crystal composition in Comparative Example 1

[0146]

[0147] Comparative Example 2: A liquid crystal composition was prepared according to the method described above in this invention, and it was filled with liquid crystal for testing and performance testing. The measured physical property parameters are shown in Table 12.

[0148] Table 12 Composition and properties of the liquid crystal compositions in Comparative Example 2

[0149]

[0150]

[0151] Compared with Comparative Example 1, Examples 1 and 2 have larger ε⊥ / |Δε| and larger elastic constants. According to the experimental data of Comparative Example 2 and Example 7, when the parameters such as clearing point, birefringence and dielectric are basically the same, by adding compound of general formula A to the liquid crystal mixture, the ratio of vertical dielectric to absolute dielectric value ε⊥ / |Δε|, elastic constants K11 and K33 of the liquid crystal composition are improved, which is more conducive to improving the transmittance of the liquid crystal display and more conducive to realizing a high contrast liquid crystal display.

[0152] The present invention relates to a naphthalene ring-containing positive and negative mixed liquid crystal composition, which has a large vertical dielectric, and the transmittance T is proportional to ε⊥ / |Δε| (the ratio of the vertical dielectric to the absolute value of the dielectric constant). This effectively improves the transmittance of the liquid crystal, thereby reducing energy consumption. It also has low rotational viscosity and high elastic constant, which can effectively improve the contrast and response speed of the liquid crystal. Furthermore, it has good low-temperature storage performance. Its excellent performance makes it well-suited for use in IPS and FFS display modes.

Claims

1. A positive and negative mixed liquid crystal composition, characterized in that: It contains the following components by weight percentage: (1) One or more compounds with the structure shown in general formula A, in a mass fraction of 1%-20%: In the formula, R1 represents a straight-chain alkyl or alkoxy group with 1-5 carbon atoms, or an alkenyl group with 2-5 carbon atoms; n1 represents 0 or 1; X1, X2, and X3 each independently represent -H or -F. ring Each independent expression (2) One or more compounds with the structure shown in general formula B, with a mass fraction of 30%-78%: In the formula, R2 and R3 each independently represent a straight-chain alkyl, straight-chain alkoxy or a chain alkenyl with carbon atoms 1-5, and n2 represents 0 or 1; ring Each independent expression (3) One or more compounds with the structure shown in general formula C, with a mass fraction of 0%-20%: In the formula, R4 represents a straight-chain alkyl group with 1-5 carbon atoms, and n3 represents 0 or 1; ring and Each independent expression (4) One or more compounds with the structure shown in general formula D, in a mass percentage of 2%-40%: In the formula, R5 represents a straight-chain alkyl group with 1-5 carbon atoms; ring Each independent expression (5) One or more compounds with the structure shown in general formula E, comprising 2%-28% by mass, wherein the compounds with the structure shown in general formula E are selected from compounds with the structure shown in general formula EⅠ and / or EⅡ: In the formula, R6 and R7 represent straight-chain alkyl groups with 1-5 carbon atoms; n4 represents 0 or 1; ring Each independent expression 2. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The compound represented by general formula A is selected from one or more compounds A-1 to A-96:

3. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The compound represented by general formula B is selected from one or more compounds B-1 to B-56:

4. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The compound represented by general formula C is selected from one or more compounds C-1 to C-25:

5. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The compound represented by general formula D is selected from one or more compounds D-1 to D-24:

6. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The compound represented by general formula E is selected from one or more of compounds EⅠ-1 to EⅠ-16 and EⅡ-1 to EⅡ-4:

7. The positive and negative mixed liquid crystal composition according to claim 1, characterized in that: The liquid crystal composition further comprises one or more compounds with the structure shown in general formula F, in a mass percentage of 0%-15%, wherein the compounds with the structure shown in general formula F are selected from compounds with the structure shown in general formula FⅠ and / or FⅡ: In the formula, R8 and R9 each independently represent a straight-chain alkyl group with 1-5 carbon atoms.

8. The positive and negative mixed liquid crystal composition according to claim 7, characterized in that: The compound represented by general formula F is selected from one or more of compounds FI-1 to FI-5 and FI-1 to FI-4:

9. The positive and negative mixed liquid crystal composition according to claim 8, characterized in that: The liquid crystal composition comprises the following components in weight percentage: (1) 2-15% of the compounds represented by general formula A; (2) 35-76% of the compounds represented by general formula B; (3) Compounds represented by general formula C at 0-15%; (4) 3-35% of compounds represented by general formula D; (5) 5% to 23% of compounds represented by general formula E; (6) Compounds represented by general formula F, accounting for 0-13%.

10. The use of the positive and negative mixed liquid crystal composition according to any one of claims 1-9 in the manufacture of a liquid crystal display device, wherein the liquid crystal display device includes liquid crystal display devices with IPS and FFS display modes.

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