TWI879391B - A high-reliability liquid crystal composition and its application - Google Patents

Abstract

The present invention discloses a liquid crystal display device, which includes a first substrate, a second substrate, and a liquid crystal combination arranged between the first substrate and the second substrate; the first substrate and the second substrate are arranged parallel to each other; an alignment layer is arranged on one side of the first substrate and the second substrate close to the liquid crystal combination; a vertical alignment film is arranged on the alignment layer to make the liquid crystal molecules in the liquid crystal combination be roughly arranged perpendicular to the first substrate and the second substrate; the liquid crystal combination includes a compound represented by formula I and a compound represented by formula II, and the liquid crystal combination has a high refractive index, a high-definition bright spot and excellent reliability, and is mainly used for display of a projector with a low box thickness and a relatively high working temperature. Ⅰ Ⅱ

Description

A high-reliability liquid crystal composition and its application

The present invention relates to the field of liquid crystal display technology and more specifically to a liquid crystal display device.

The application of LCD is becoming more and more extensive, mainly in display terminals such as mobile phones, computers, televisions, car-mounted, outdoor displays, medical equipment, etc. With the rapid development of science and technology, people's requirements for display technology are constantly increasing, the display industry is also constantly moving forward, and the application and demand for LCD components are also increasing.

In recent years, with the expansion of liquid crystal display applications in projectors, outdoor displays, and other directions, these special use scenarios are also putting forward higher requirements on the parameter specification range of liquid crystal materials. Taking the application of projectors as an example, first of all, because the operating temperature of the projector panel is maintained above 60 ℃ for a long time and sometimes even exceeds 80 ℃, the panel is required to have a high clear point to maintain normal display at high temperatures. Secondly, due to the low box thickness design of the projector, in order to ensure the appropriate delay required for normal display, the liquid crystal material is required to have an ultra-high refractive index while maintaining high-definition bright points. In order to achieve a better display effect, the liquid crystal material needs to have good resistance to ultraviolet rays, high temperatures, and backlight while having high-definition bright points and high refractive index.

In short, liquid crystal materials need to have high-definition bright spots, high refractive index, and excellent reliability in order to better meet the application scenarios of panels such as projectors, outdoor displays, and LCOS (Liquid Crystal on Silicon) reflective projection displays.

In order to solve at least one problem existing in the prior art, the present invention provides a liquid crystal composition on the one hand, which has a higher clearing point, a larger refractive index and particularly good reliability, and can be used to develop a high-transmittance liquid crystal display element or liquid crystal display.

To achieve the above purpose, the present invention adopts the following technical solutions:

The present invention provides a liquid crystal display device, which comprises a first substrate, a second substrate, and a liquid crystal combination arranged between the first substrate and the second substrate; the first substrate and the second substrate are arranged parallel to each other, and an alignment layer is arranged on the first substrate and the second substrate near the liquid crystal combination; the alignment layer is provided with a vertical alignment film for arranging liquid crystal molecules in the liquid crystal combination approximately perpendicular to the first substrate and the second substrate; the liquid crystal combination comprises one or more compounds represented by formula I, two or more compounds represented by formula II, and the mass content of the compound represented by formula I is ≤10%, and the mass content of the compound represented by formula II is ≥20%, Ⅰ Ⅱ wherein R ₁ , R ₂ , and R ₃ each independently represent a linear alkyl group having 1 to 5 carbon atoms or a linear alkenyl group having 2 to 5 carbon atoms; R ₄ represents an alkoxy group having 1 to 5 carbon atoms; n represents 0 or 1; , Each independently expresses or .

Invention Effect

The technical solution of the present invention is mainly used in the fields of projectors, vehicle-mounted, outdoor displays, etc. The liquid crystal composition of the present invention has high optical anisotropy, a high upper limit of operating temperature, a large dielectric anisotropy, and excellent reliability, and is particularly suitable for liquid crystal displays operating at high temperatures.

The present invention provides a liquid crystal display device, which comprises a first substrate, a second substrate, and a liquid crystal combination arranged between the first substrate and the second substrate; the first substrate and the second substrate are arranged parallel to each other, and an alignment layer is arranged on the first substrate and the second substrate near the liquid crystal combination; the alignment layer is provided with a vertical alignment film for arranging liquid crystal molecules in the liquid crystal combination approximately perpendicular to the first substrate and the second substrate; the liquid crystal combination comprises one or more compounds represented by formula I, two or more compounds represented by formula II, and the mass content of the compound represented by formula I is ≤10%, and the mass content of the compound represented by formula II is ≥20%, Ⅰ Ⅱ wherein R ₁ , R ₂ , and R ₃ each independently represent a linear alkyl group having 1 to 5 carbon atoms or a linear alkenyl group having 2 to 5 carbon atoms; R ₄ represents an alkoxy group having 1 to 5 carbon atoms; n represents 0 or 1; , Each independently expresses or .

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula I is selected from the group consisting of compounds represented by the following formulas I-1 to I-4, Ⅰ-1 Ⅰ-2 Ⅰ-3 I-4 wherein R ₁ and R ₂ each independently represent a linear alkyl group having 1 to 5 carbon atoms or a linear alkenyl group having 2 to 5 carbon atoms.

The liquid crystal composition of the present invention preferably comprises at least one compound represented by formula I-3 and/or I-4, wherein the total mass content of the compounds represented by formula I-3 and/or I-4 is ≤5%.

In the liquid crystal composition of the present invention, it is further preferred that the compound represented by the aforementioned formula I-4 comprises the compound represented by the formula I-4-1,

.

In the liquid crystal composition of the present invention, more preferably, the mass content of the compound represented by the aforementioned formula Ⅰ-4-1 is 1% to 3%.

The liquid crystal composition of the present invention is preferably such that the mass content of the compound represented by formula II in the aforementioned liquid crystal composition is ≥30%.

The liquid crystal composition of the present invention is further preferably such that the mass content of the compound represented by formula II in the liquid crystal composition is 30% to 35%.

The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula III. III wherein, R ₅ represents a linear alkyl group having 1 to 5 carbon atoms or a linear alkenyl group having 2 to 5 atoms, and any one or more unconnected -CH ₂ - in R ₅ may be substituted by cyclopropylene, cyclobutylene or cyclopentylene; R ₆ represents an alkoxy group having 1 to 5 carbon atoms; express , , or .

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III is selected from the group consisting of compounds represented by the following formulae III-1 to III-3, III-1 III-2 III-3 wherein R ₅ represents a straight-chain alkyl group having 1 to 5 carbon atoms or a straight-chain alkenyl group having 2 to 5 carbon atoms, and any one or more unconnected -CH ₂ - groups in R ₅ may be arbitrarily substituted by cyclopropylene, cyclobutylene or cyclopentylene; R ₆ represents an alkoxy group having 1 to 5 carbon atoms.

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-1 is selected from the group consisting of the compounds represented by the following III-1-1 to III-1-15, III-1-1 III-1-2 III-1-3 III-1-4 III-1-5 III-1-6 III-1-7 III-1-8 III-1-9 III-1-10 III-1-11 III-1-12 III-1-13 III-1-14 Ⅲ-1-15.

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-2 is selected from the group consisting of the compounds represented by the following III-2-1 to III-2-16, III-2-1 III-2-2 III-2-3 III-2-4 III-2-5 III-2-6 III-2-7 III-2-8 III-2-9 III-2-10 III-2-11 III-2-12 III-2-13 III-2-14 III-2-15 Ⅲ-2-16.

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula III-3 is selected from the group consisting of the compounds represented by the following III-3-1 to III-3-10, III-3-1 III-3-2 III-3-3 III-3-4 III-3-5 III-3-6 III-3-7 III-3-8 III-3-9 Ⅲ-3-10.

In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by the aforementioned formula III is 40-62%.

The liquid crystal composition of the present invention is further preferably such that the mass content of the compound represented by the aforementioned formula III is 50-62%.

The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula IV. IV wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyloxy group having 2 to 5 carbon atoms; X ₂ , X ₃ , X ₄ , and X ₅ each independently represent an H atom or an F atom, and at least one of X ₂ , X ₃ , X ₄ , and X ₅ represents an F atom.

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula IV is selected from the group consisting of compounds represented by the following formulae IV-1 to IV-6, IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyloxy group having 2 to 5 carbon atoms.

The liquid crystal composition of the present invention preferably comprises at least one compound represented by formula IV-2.

In the liquid crystal composition of the present invention, preferably, the mass content of the compound represented by the aforementioned formula IV-2 is 1-5%.

The liquid crystal composition of the present invention preferably does not contain the compound represented by formula V. Ⅴ

Here, R ₉ and R ₁₀ each independently represent an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms.

The liquid crystal composition of the present invention preferably does not contain the compound represented by formula VI. VI wherein R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms or an alkenyloxy group having 2 to 5 carbon atoms, and any one or more unconnected -CH ₂ - groups in R ₁₁ and R ₁₂ may be optionally substituted by cyclopropylene, cyclobutylene or cyclopentylene; X ₆ represents -O-, -S- or -CH ₂ O-.

The liquid crystal composition of the present invention may further include dopants with various functions.

In the liquid crystal composition of the present invention, preferably, the above-mentioned dopant is mainly an antioxidant, a light stabilizer, etc.

In the liquid crystal composition of the present invention , the amount of the dopant added is preferably between 0.01% and 1% of the mass of the liquid crystal composition.

In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

In this manual, unless otherwise specified, percentages refer to mass percentages, and temperatures are in degrees Celsius (℃). The specific meanings of other symbols and test conditions are as follows: Cp represents the clearing point of liquid crystal (℃), tested by DSC quantitative method; Δn represents optical anisotropy, n _o represents the refractive index of ordinary light, _ne represents the refractive index of extraordinary light, and the test conditions are 25±2 ℃, 589 nm, and Abbe refractometer test; Δε represents dielectric anisotropy, 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±0.5 ℃, 20 micron parallel box, and INSTEC:ALCT-IR1 test; γ ₁ represents rotational viscosity (mPa·s), and the test conditions are 25±0.5 ℃, 20 micron parallel box, INSTEC: ALCT-IR1 test; K ₁₁ is the splay elastic constant, K ₂₂ is the torsion elastic parameter, and K ₃₃ is the bending elastic constant. The test conditions are: 25 ℃, INSTEC: ALCT-IR1, 20 micron vertical box; VHR represents voltage holding rate (%), and the test conditions are 60±2 ℃, voltage is ±1V, pulse width is 10ms, and voltage holding time is 16.7ms. The test equipment is TOYO Model 6254 LCD performance comprehensive tester; Afterimage: Pour the liquid crystal composition into the IPS parallel box to make a liquid crystal display element, place the liquid crystal display element in a 25 ℃ environment, test the voltage-transmittance characteristics, and calculate the AC voltage (V23) with a relative transmittance of 23%. The brightness under V23 is tested and recorded as the initial brightness Lv ₁ . A 10V AC voltage is applied to the liquid crystal display element for 168h. After 168h, the brightness under V23 is immediately tested and recorded as the brightness after aging Lv ₂ . The percentage difference in brightness between the aging and initial values ΔTr (%) is calculated. ΔTr=｜Lv ₂ - Lv ₁ ｜/ Lv ₁ *100. The following 3 levels of evaluation are performed based on the value of ΔTr: ◎: ΔTr≤1.0%, the afterimage characteristic is good and acceptable; △: 1.0%＜ΔTr≤2.0%, the afterimage characteristic is qualified and acceptable; ×: ΔTr＞2.0%, the afterimage characteristic is poor and unacceptable.

The preparation method of the liquid crystal composition is as follows: each liquid crystal monomer is weighed according to a certain ratio and put into a stainless steel beaker, the stainless steel beaker containing each liquid crystal monomer is placed on a magnetic stirrer to heat and melt, and after most of the liquid crystal monomers in the stainless steel beaker are melted, a magnetic rotor is added to the stainless steel beaker, the mixture is stirred evenly, and the liquid crystal composition is obtained after cooling to room temperature.

The liquid crystal monomer structure of the embodiment of the present invention is represented by a code, and the code representation method of the liquid crystal ring structure, end group, and connecting group is shown in Table 1 and Table 2 below.

Table 1 Corresponding codes of ring structures Ring structure Corresponding code C L P G Gi Y B Sb Sc

Table 2 Corresponding codes of terminal groups and linking groups Terminal groups and linking groups Corresponding code C _n H _2n+1 - n- C _n H _2n+1 O- nO- _-CH2O- -O- -F -F -CH ₂ CH ₂ - -E- -CH=CH- -V- -COO- -COO- -CH=CH-C _n H _2n+1 -Vn Cp- CpO- Cpr- Cpr1-

For example: , its code is CC-Cp-V1; , its code is PPY-3-O2; , its code is CPY-2-O2; , its code is CCY-3-O2; , its code is COY-3-O2; , its code is CCOY-3-O2; , its code is CLY-3-O2; , its code is Sb-CpO-O4; , whose code is Sc-CpO-O4; , whose code is PGP-Cpr1-2; , whose code is B-2O-O4; , its code is B-CpO-O4; , its code is CY-3-O2; , its code is PP-1-2V; , whose code is PGP-5-2.

The present invention is described below using the following specific embodiments:

Embodiment

Embodiment 1

The formula of the liquid crystal composition and the corresponding properties are shown in Table 3 below.

Table 3 Formulation of the liquid crystal composition of Example 1 and its corresponding properties Category Liquid crystal unit code content(%) Ⅰ CC-4-3 4.5 Ⅰ CPP-3-2 1.5 Ⅱ CY-3-O2 10 Ⅱ CY-3-O4 14 Ⅱ CY-5-O2 10 III CCY-2-O2 8 III CCY-3-O1 8 III CCY-3-O2 5 III CCY-4-O2 7 III CPY-2-O2 9 III CPY-3-O2 7 III CPY-3-O4 7 III CLY-3-O3 3 III CLY-4-O2 3 IV PYP-2-3 3 Cp: 95.6 ℃ Δε [1KHz, 25 ℃]: -6.48 Δn [589 nm, 25 ℃]: 0.116 γ ₁ : 238.6 K ₁₁ : 15.1 K ₃₃ : 16.5

Embodiment 2

The formula of the liquid crystal composition and the corresponding properties are shown in Table 4 below.

Table 4 Formulation of the liquid crystal composition of Example 2 and its corresponding properties Category Liquid crystal unit code content(%) Ⅰ CC-4-3 4 Ⅰ CPP-3-2 2 Ⅱ CY-3-O2 10 Ⅱ CY-3-O4 14 Ⅱ CY-5-O2 10 III CCY-2-O2 9 III CCY-3-O1 8 III CCY-3-O2 9 III CCY-4-O2 8 III CPY-2-O2 9 III CPY-3-O2 7 III CPY-3-O4 7 IV PYP-2-3 3 Cp: 95.9 ℃ Δε [1KHz, 25 ℃]: -6.48 Δn [589 nm, 25 ℃]: 0.116 γ ₁ : 241.2 K ₁₁ : 15.1 K ₃₃ : 16.9

Embodiment 3

The formula of the liquid crystal composition and the corresponding properties are shown in Table 5 below.

Table 5 Formulation and corresponding properties of the liquid crystal composition of Example 3 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 3 Ⅱ CY-3-O2 11 Ⅱ CY-3-O4 14 Ⅱ CY-5-O2 10 III CCY-2-O2 8 III CCY-3-O1 8 III CCY-3-O2 9 III CCY-4-O2 7 III CPY-2-O2 9 III CPY-3-O2 9 III CPY-3-O4 9 III CLY-4-O2 3 Cp: 97.1 ℃ Δε [1KHz, 25 ℃]: -6.81 Δn [589 nm, 25 ℃]: 0.115 γ ₁ : 254.6 K ₁₁ : 15.2 K ₃₃ : 17.3

Embodiment 4

The formula of the liquid crystal composition and the corresponding properties are shown in Table 6 below.

Table 6 Formulation and corresponding properties of the liquid crystal composition of Example 4 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 5 Ⅰ CPP-3-2 5 Ⅱ CY-3-O2 10 Ⅱ CY-3-O4 14 Ⅱ CY-5-O2 10 III CCY-2-O2 7 III CCY-3-O1 8 III CCY-3-O2 5 III CCY-4-O2 6 III CPY-2-O2 9 III CPY-3-O2 8 III CPY-3-O4 7 III CLY-3-O3 3 III CLY-4-O2 3 Cp: 96.9 ℃ Δε [1KHz, 25 ℃]: -6.23 Δn [589 nm, 25 ℃]: 0.115 γ ₁ : 228.2 K ₁₁ : 15.3 K ₃₃ : 16.7

Embodiment 5

The formula of the liquid crystal composition and the corresponding properties are shown in Table 7 below.

Table 7 Formulation and corresponding properties of the liquid crystal composition of Example 5 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 3 Ⅰ CCP-3-1 2 Ⅰ CPP-3-2 3 Ⅱ CY-3-O2 14 Ⅱ CY-3-O4 14 Ⅱ CY-5-O2 10 III CCY-2-O2 7 III CCY-3-O1 8 III CCY-3-O2 8 III CCY-4-O2 7 III CPY-2-O2 9 III CPY-3-O2 8 III CPY-3-O4 7 Cp: 95.1 ℃ Δε [1KHz, 25 ℃]: -6.45 Δn [589 nm, 25 ℃]: 0.116 γ ₁ : 235.2 K ₁₁ : 14.6 K ₃₃ : 16.9

Comparative Example 1

The formula of the liquid crystal composition and the corresponding properties are shown in Table 8 below.

Table 8 Formula and corresponding properties of the liquid crystal composition of Comparative Example 1 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 6 Ⅰ CPP-3-2 5 Ⅱ CY-3-O2 12 Ⅱ CY-3-O4 6 III CCY-2-O2 8 III CCY-3-O1 8 III CCY-3-O2 8 III CCY-4-O2 8 III CPY-2-O2 6 III CPY-3-O2 9 III CPY-3-O4 5 III CLY-3-O3 5 III CLY-4-O2 4 Ⅴ PY-3-O2 10 Cp: 95.0 ℃ Δε [1KHz, 25 ℃]: -6.45 Δn [589 nm, 25 ℃]: 0.116 γ ₁ : 228.3 K ₁₁ : 15.3 K ₃₃ : 16.8

Comparative Example 2

The formula of the liquid crystal composition and the corresponding properties are shown in Table 9 below.

Table 9 Formula and corresponding properties of the liquid crystal composition of Comparative Example 2 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 10 Ⅰ CPP-3-2 3 Ⅱ CY-3-O2 7 Ⅱ CY-3-O4 7 Ⅱ CY-5-O2 4 III CCY-2-O2 10 III CCY-3-O1 9 III CCY-3-O2 8 III CCY-4-O2 8 III CPY-2-O2 9 III CPY-3-O2 9 III CPY-3-O4 9 VI Sc-CpO-O4 7 Cp: 97.3 ℃ Δε [1KHz, 25 ℃]: -6.54 Δn [589 nm, 25 ℃]: 0.116 γ ₁ : 243.2 K ₁₁ : 16.1 K ₃₃ : 16.8

Comparative Example 3

The formula of the liquid crystal composition and the corresponding properties are shown in Table 10 below.

Table 10 Formulation and corresponding properties of the liquid crystal composition of Comparative Example 3 Category Liquid crystal unit code content(%) Ⅰ CC-4-3 7 Ⅰ CCP-3-1 2 COY-3-O2 8 COY-3-O4 7 COY-3-O1 5 III CCY-2-O2 11 III CCY-3-O1 8 III CCY-3-O2 8 III CCY-4-O2 8 III CPY-2-O2 7 III CPY-3-O2 8 III CPY-3-O4 5 III CLY-3-O3 3 III CLY-4-O2 3 Ⅴ PY-3-O2 10 Cp: 95.2 ℃ Δε [1KHz, 25 ℃]: -6.55 Δn [589 nm, 25 ℃]: 0.116 K ₁₁ : 15.7 K ₃₃ : 16.8

Comparative Example 4

The formula of the liquid crystal composition and the corresponding properties are shown in Table 11 below.

Table 11 Formulation of liquid crystal composition of comparative example 4 and corresponding properties Category Liquid crystal unit code content(%) PP-5-1 5 PGP-3-2 2 COY-3-O2 10 COY-3-O4 12 COY-5-O2 4 III CCY-2-O2 7 III CCY-3-O1 8 III CPY-2-O2 10 III CPY-3-O2 9 III CPY-3-O4 8 IV PYP-2-3 3 CCOY-2-O2 12 CCOY-3-O2 10 Cp: 95.0 ℃ Δε [1KHz, 25 ℃]: -6.61 Δn [589 nm, 25 ℃]: 0.116 K ₁₁ : 15.4 K ₃₃ : 17.3

The liquid crystal compositions of the embodiments and comparative examples are poured into a liquid crystal test box, and the reliability of the liquid crystal compositions is tested by UV, high temperature, backlight aging tests and VHR tests. The smaller the change in VHR data of the liquid crystal composition before and after the UV, high temperature, backlight aging tests, the stronger the anti-ultraviolet, high temperature, and backlight capabilities. Therefore, the anti-ultraviolet, high temperature, and backlight capabilities are judged by comparing the difference in VHR data before and after the tests of each embodiment and comparative example.

First, before conducting the UV, high temperature, and backlight aging tests, the VHR data of the liquid crystal composition is measured as the initial VHR data. Then, the liquid crystal composition is subjected to the UV, high temperature, and backlight aging tests, and the VHR data of the liquid crystal composition is measured again after the tests.

UV aging test: The liquid crystal composition is placed under a UV lamp with a wavelength of 365 nm and irradiated with 5000mJ energy.

High temperature aging test: Place the liquid crystal composition in a 100 ℃ oven for one hour.

Backlight aging test: Place the liquid crystal composition on a backlight with a brightness of 25000 nits in a 60 ℃ oven for 500 h.

The smaller the change of the VHR data after the aging test relative to the initial VHR data, the stronger the ability of the liquid crystal composition to resist ultraviolet, high temperature and backlight, and thus it can be judged that the liquid crystal composition has a stronger ability to resist external environmental damage during operation, and therefore, the higher the reliability of the liquid crystal composition. In addition, the liquid crystal compositions of the embodiment and the comparative example were poured into a liquid crystal test box and subjected to an afterimage test, and the test results are shown in the following Table 12.

Table 12 Reliability test data for examples and comparative examples Serial number VHR (initial) VHR (ultraviolet) VHR (high temperature) VHR (Backlight) △Tr（%) Remains Embodiment 1 98.89 98.76 98.85 97.78 0.1 ◎ Embodiment 2 98.87 98.77 98.83 97.80 0.1 ◎ Embodiment 3 98.89 98.55 98.53 97.58 0.5 ◎ Embodiment 4 98.90 98.72 98.81 97.74 0.3 ◎ Embodiment 5 98.92 98.73 98.81 97.77 0.2 ◎ Comparative Example 1 98.25 98.23 98.13 94.10 2.1 × Comparative Example 2 98.37 98.12 98.20 94.70 2.2 × Comparative Example 3 98.12 97.83 98.01 93.56 2.1 × Comparative Example 4 98.15 97.87 98.02 93.78 2.3 ×

It can be seen from Table 10 above that, compared with Comparative Examples 1 to 2, the liquid crystal compositions of Examples 1 to 5 of the present invention have a high initial VHR, and a small decrease in VHR after ultraviolet light, high temperature, and backlight. The liquid crystal compositions of Examples 1 to 5 have good resistance to ultraviolet light, high temperature, and backlight, and the improvement in afterimage defects is more obvious.

Obviously, the above embodiments of the present disclosure are merely examples for clearly illustrating the present disclosure, and are not intended to limit the implementation methods of the present disclosure. For ordinary technical personnel in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solutions of the present disclosure are still within the scope of protection of the present disclosure.

Claims (8)

A liquid crystal display device comprises a first substrate, a second substrate, and a liquid crystal composition arranged between the first substrate and the second substrate; the first substrate and the second substrate are arranged parallel to each other and an alignment layer is arranged on one side of the first substrate and the second substrate close to the liquid crystal composition; the alignment layer is provided with a vertical alignment film that makes the liquid crystal molecules in the liquid crystal composition arranged roughly perpendicular to the first substrate and the second substrate; the liquid crystal composition comprises one or two compounds represented by formula I-3 and I-4, and two or more compounds represented by formula II, the total mass content of the compounds represented by formula I-3 and/or I-4 is ≤5%, and the mass content of the compounds represented by formula II is ≥20%, Ⅰ-3 Ⅰ-4 Ⅱ wherein R ₁ , R ₂ , and R ₃ each independently represent a straight-chain alkyl group having 1 to 5 carbon atoms or a straight-chain alkenyl group having 2 to 5 carbon atoms; R ₄ represents an alkoxy group having 1 to 5 carbon atoms; and n represents 0 or 1. The liquid crystal display device according to claim 1, wherein the liquid crystal composition further comprises one or more compounds represented by formula III, III wherein, R ₅ represents a linear alkyl group having 1 to 5 carbon atoms or a linear alkenyl group having 2 to 5 atoms, and any one or more unconnected -CH ₂ - in R ₅ may be substituted by cyclopropylene, cyclobutylene or cyclopentylene; R ₆ represents an alkoxy group having 1 to 5 carbon atoms; express , , or . The liquid crystal display device according to claim 1, wherein the liquid crystal composition further comprises one or more compounds represented by formula IV, IV wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyloxy group having 2 to 5 carbon atoms; X ₂ , X ₃ , X ₄ , and X ₅ each independently represent an H atom or an F atom, and at least one of X ₂ , X ₃ , X ₄ , and X ₅ represents an F atom. The liquid crystal display device according to claim 3, wherein the compound represented by formula IV is selected from the group consisting of compounds represented by formulas IV-1 to IV-6 below, IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 wherein R ₇ and R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkenyloxy group having 2 to 5 carbon atoms. According to the liquid crystal display device described in claim 4, the liquid crystal composition contains at least one compound represented by formula IV-2. The liquid crystal display device according to claim 1, wherein the liquid crystal composition does not contain the compound represented by formula V, V wherein R ₉ and R ₁₀ each independently represent an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. According to the liquid crystal display device described in claim 2, the mass content of the compound represented by formula III is 40-62%. According to the liquid crystal display device described in claim 5, the mass content of the compound represented by formula IV-2 is 1-5%.