TWI882651B - High reliability cholesteric liquid crystal composition, liquid crystal display element and liquid crystal display - Google Patents

Abstract

The present invention discloses a cholesteric phase liquid crystal composition, which comprises one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III and one or more compounds represented by formula IV. The liquid crystal composition has a large optical anisotropy (Δn), a high charge retention rate (VHR), a low viscosity and a large dielectric anisotropy, and can be used in optical devices such as electronic books. Ⅰ Ⅱ III IV

Description

Highly reliable cholesteric liquid crystal composition, liquid crystal display element and liquid crystal display

The invention of this application relates to a cholesteric liquid crystal composition used as a display element material and a display element using the same, which is mainly applicable to technical fields such as liquid crystal e-books, electronic signs, and dual-stable liquid crystal displays.

Cholesteric liquid crystal e-books have the advantages of high contrast and zero power consumption for displaying content, and can replace paper in daily life. They are mainly used in e-books, electronic labels, display panels, etc. At present, cholesteric liquid crystal compositions are obtained by adding optically active chiral agents to nematic liquid crystals. The planar state and focal conical state of cholesteric liquid crystals are stable and can remain stable for a long time, thus having dual stability.

The liquid crystal of the cholesteric phase liquid crystal has Bragg reflection in the planar state. The reflection wavelength (λ) is determined by the average refractive index (n) of the liquid crystal composition and the chiral pitch (P), λ = n _average × P. When the refractive index of the liquid crystal composition is fixed, the chiral pitch P can be adjusted by increasing or decreasing the amount of chiral compounds, thereby obtaining different colors of reflection wavelengths. Under the same pitch, the wavelength of the reflected light (Δλ) is proportional to the refractive index anisotropy of the liquid crystal (Δn = ne-no). In order to achieve high brightness of reflection, a liquid crystal composition with a large Δn is required.

The calculation formula of the threshold voltage of cholesteric liquid crystal is: Where h is the thickness of the liquid crystal cell, △ε is the dielectric of the liquid crystal, P is the pitch value of the liquid crystal, and _K22 is the twist elastic coefficient of the liquid crystal. The general cholesteric phase liquid crystal driving voltage is >35V. In order to reduce the driving voltage, the dielectric anisotropy Generally, it can reach >20, or even >30. A large number of polar liquid crystal monomers with large dielectric constants and cyano groups are used in liquid crystal compositions. When making e-books, the charge retention rate (VHR) of the liquid crystal composition is relatively poor, and the reliability test results under high temperature and high humidity are very poor. The driving power consumption current is getting larger and larger, which can seriously lead to poor driving at the edge of the screen and serious screen flickering problems under low-frequency driving. These existing problems seriously affect the application of cholesteric phase liquid crystals in e-books and need to be solved urgently.

The present invention provides a technical solution that can solve the above technical problems.

The cholesteric phase liquid crystal composition provided by the present invention has a large optical anisotropy (Δn), a high charge retention rate (VHR), a low viscosity, a large dielectric anisotropy (Δε) and excellent reliability performance. It can be used in the field of optical devices such as liquid crystal e-books and can effectively improve the problem of poor edge driving and screen flickering caused by low-frequency driving.

Specifically, the present invention includes the following contents:

The present invention provides a liquid crystal composition, comprising one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III and one or more compounds represented by formula IV. Ⅰ Ⅱ III IV wherein R ₁ , R ₂ , R ₃ , R ₅ , and R ₆ each independently represent H, F, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with fluorine, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms substituted with fluorine, an alkenyl group having 2 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms substituted with fluorine, an alkenyloxy group having 3 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms substituted with fluorine, and any one or more -CH ₂ - groups represented by R ₁ , R ₂ , R ₃ , R ₅ , and R ₆ are optionally replaced by cyclopentylene, cyclobutylene, or cyclopropylene; X ₁ , X ₂ , X ₃ , X ₄ , X _{5 , X 6 ,} and X ₇ , X ₈ , X ₁₁ , and X ₁₂ each independently represent H or F, and X ₁ and X ₂ do not simultaneously represent F; m and n each independently represent 0, 1 or 2, and m+n≥1; k represents 1, 2 or 3; m´ represents 1 or 2; , , , Each independently expresses , , , , , or ; express , , , , , or .

The present invention also provides a cholesteric liquid crystal display element, which comprises the liquid crystal composition disclosed in the present invention. The cholesteric liquid crystal display element is an active matrix addressing display element or a passive matrix addressing display element.

The present invention also provides a cholesteric liquid crystal display, which comprises the liquid crystal composition disclosed in the present invention. The cholesteric liquid crystal display is an active matrix addressing display or a passive matrix addressing display.

Invention Effect

The liquid crystal composition provided by the present invention has a large optical anisotropy (Δn), a high charge retention rate (VHR), a low viscosity, a large dielectric anisotropy (Δε) and excellent reliability performance. It can be used in optical device technology fields such as liquid crystal e-books and can effectively improve the problem of poor edge driving and screen flickering caused by low-frequency driving.

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.

The present invention provides a liquid crystal composition, comprising one or more compounds represented by formula I, one or more compounds represented by formula II, one or more compounds represented by formula III and one or more compounds represented by formula IV. Ⅰ Ⅱ III IV wherein R ₁ , R ₂ , R ₃ , R ₅ , and R ₆ each independently represent H, F, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with fluorine, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms substituted with fluorine, an alkenyl group having 2 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms substituted with fluorine, an alkenyloxy group having 3 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms substituted with fluorine, and any one or more -CH ₂ - groups represented by R ₁ , R ₂ , R ₃ , R ₅ , and R ₆ are optionally replaced by cyclopentylene, cyclobutylene, or cyclopropylene; X ₁ , X ₂ , X ₃ , X ₄ , X 5 , X _{6 ,} and X ₇ , X ₈ , X ₁₁ , and X ₁₂ each independently represent H or F, and X ₁ and X ₂ do not simultaneously represent F; m and n each independently represent 0, 1 or 2, and m+n≥1; k represents 1, 2 or 3; m´ represents 1 or 2; , , , Each independently expresses , , , , , or ; express , , , , , 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-13, Ⅰ-1 Ⅰ-2 Ⅰ-3 Ⅰ-4 Ⅰ-5 Ⅰ-6 Ⅰ-7 Ⅰ-8 Ⅰ-9 Ⅰ-10 Ⅰ-11 Ⅰ-12 Ⅰ-13 wherein _R1 represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine, and any one or more _-CH2- groups in the group represented by _R1 are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

In the liquid crystal composition of the present invention, it is further preferred that the compound represented by the aforementioned formula I is selected from the group consisting of compounds represented by formulas I-1 to I-3; and it is further preferred that the compound represented by the aforementioned formula I is selected from the compound represented by formula I-1.

The liquid crystal composition of the present invention is further preferably, the mass content of the compound represented by the aforementioned formula I in the liquid crystal composition is 6-20%, and further preferably 9-12%.

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula II is selected from the group consisting of compounds represented by the following formulae II-1 to II-13, Ⅱ-1 Ⅱ-2 Ⅱ-3 Ⅱ-4 Ⅱ-5 Ⅱ-6 Ⅱ-7 Ⅱ-8 Ⅱ-9 Ⅱ-10 Ⅱ-11 Ⅱ-12 II-13 wherein R ₂ represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine, and any one or more -CH ₂ - groups in the group represented by R ₂ are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

The liquid crystal composition of the present invention is further preferably a compound represented by the aforementioned formula II selected from the group consisting of compounds represented by formulas II-3, II-7, II-10 and II-12; and further preferably, it comprises compounds represented by formulas II-3 and II-10.

The liquid crystal composition of the present invention is further preferably such that the mass content of the compound represented by the aforementioned formula II in the liquid crystal composition is 5-26%, and further preferably 14-18%.

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-9, III-1 III-2 III-3 III-4 III-5 III-6 III-7 III-8 III-9 wherein R ₃ represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine, and any one or more -CH ₂ - groups in the group represented by R ₃ are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

The liquid crystal composition of the present invention is further preferably a compound represented by the aforementioned formula III selected from the group consisting of compounds represented by formulas III-1, III-2, III-3, III-4 and III-5; and further preferably, comprises compounds represented by III-1 and III-2.

The liquid crystal composition of the present invention is further preferably, the mass content of the compound represented by the aforementioned formula III in the liquid crystal composition is 2-20%, and further preferably 3-9%.

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-12, IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 IV-7 IV-8 IV-9 IV-10 IV-11 IV-12 wherein R ₅ and R ₆ each independently represent H, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine, and any one or more -CH ₂ - groups in the groups represented by R ₅ and R ₆ are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

The liquid crystal composition of the present invention preferably comprises the compound represented by the aforementioned formula IV selected from the group consisting of compounds represented by formulas IV-1, IV-9 and IV-11; more preferably, comprises the compound represented by IV-1.

The liquid crystal composition of the present invention is further preferably, the mass content of the compound represented by the aforementioned formula IV in the liquid crystal composition is 10-45%, and further preferably 26-40%.

The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula V, Ⅴ wherein, _R4 represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more _-CH2- in the group represented by _R4 is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene; _Z1 represents a single bond or -COO-; _X9 and _X10 each independently represent H or F; p represents 1 or 2; express , , , , , or .

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V is selected from the group consisting of compounds represented by the following formulas V-1 to V-21, Ⅴ-1 Ⅴ-2 Ⅴ-3 Ⅴ-4 Ⅴ-5 Ⅴ-6 Ⅴ-7 Ⅴ-8 Ⅴ-9 Ⅴ-10 Ⅴ-11 Ⅴ-12 Ⅴ-13 Ⅴ-14 Ⅴ-15 Ⅴ-16 Ⅴ-17 Ⅴ-18 Ⅴ-19 Ⅴ-20 Ⅴ-21 R ₄ represents H, F, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with fluorine, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms substituted with fluorine, an alkenyl group having 2 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms substituted with fluorine, an alkenyloxy group having 3 to 8 carbon atoms, or an alkenyloxy group having 3 to 8 carbon atoms substituted with fluorine; and any one or more -CH ₂ - in the group represented by R ₄ is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene

The liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula V is selected from the group consisting of compounds represented by formulas V-1, V-2, V-3, V-4, V-13, V-14, V-15 and V-17; more preferably, it includes compounds represented by V-1, V-3, V-6, V-8, V-15 and V-19.

The liquid crystal composition of the present invention is further preferably such that the mass content of the compound represented by the aforementioned formula V in the liquid crystal composition is 2-50%, and further preferably 15-35%.

The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula VI, VI wherein, _R7 independently represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more _-CH2- in the group represented by _R7 is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene; _X13 and _X14 independently represent H or F; nˊ represents 1 or 2; express , or .

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VI is selected from the group consisting of compounds represented by the following formulae VI-1 to VI-16, VI-1 VI-2 VI-3 VI-4 VI-5 VI-6 VI-7 VI-8 VI-9 VI-10 VI-11 VI-12 VI-13 VI-14 VI-15 VI-16 wherein _R7 independently represents H, F, alkyl having 1-6 carbon atoms, alkyl having 1-6 carbon atoms substituted with fluorine, alkoxy having 1-6 carbon atoms, alkoxy having 1-6 carbon atoms substituted with fluorine, alkenyl having 2-6 carbon atoms, alkenyl having 2-6 carbon atoms substituted with fluorine, alkenyloxy having 3-8 carbon atoms or alkenyloxy having 3-8 carbon atoms substituted with fluorine; and any one or more _-CH2- in the group represented by _R7 is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

The liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VI is selected from the group consisting of compounds represented by formulae VI-1, VI-3, VI-5, VI-7, VI-9 and VI-12; more preferably, it comprises compounds represented by VI-1, VI-3 and VI-12.

The liquid crystal composition of the present invention is further preferably such that the mass content of the compound represented by the aforementioned formula VI in the liquid crystal composition is 0-20%, and further preferably 3-10%.

The liquid crystal composition of the present invention preferably further comprises one or more chiral active substances selected from the following formulae VII, VIII and IX, VII VIII IX R ₈ , R ₉ , R ₁₀ , and R ₁₁ each independently represent H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more -CH ₂ - in the groups represented by R ₈ , R ₉ , R ₁₀ , and R ₁₁ is optionally replaced by cyclopentylene, cyclobutylene, or cyclopropylene; X ₁₅ and X ₁₆ each independently represent H or F; at least one of them is F; q represents 1 or 2; express , , or .

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

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula VIII comprises at least one compound represented by formula VIII-1, Ⅷ-1

In the liquid crystal composition of the present invention, preferably, the compound represented by the aforementioned formula IX is selected from the group consisting of compounds represented by the following formulas IX-1 to IX-6, Ⅸ-1 Ⅸ-2 Ⅸ-3 Ⅸ-4 Ⅸ-5 IX-6 R ₁₁ represents H, F, alkyl having 1-6 carbon atoms, alkyl having 1-6 carbon atoms substituted with fluorine, alkoxy having 1-6 carbon atoms, alkoxy having 1-6 carbon atoms substituted with fluorine, alkenyl having 2-6 carbon atoms, alkenyl having 2-6 carbon atoms substituted with fluorine, alkenyloxy having 3-8 carbon atoms or alkenyloxy having 3-8 carbon atoms substituted with fluorine; and any one or more -CH ₂ - in the group represented by R ₁₁ is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene.

The liquid crystal composition of the present invention is further preferably selected from the following formula VII in the optical chiral substance shown above, and the compound shown in the above formula VII is added on the basis of 100% by mass percentage of the liquid crystal composition, wherein the mass content of the compound shown in formula VII is 0.5-10%, and further preferably 1.9-4.2%.

Various functional dopants may be added to the cholesteric liquid crystal compound disclosed in the present invention, and the dopant content is preferably between 0.01% and 1%. These dopants include, for example, antioxidants and light stabilizers. Antioxidants include, Where t represents an integer from 1 to 10, and the light stabilizers can be listed as follows: .

Liquid crystal display element or liquid crystal display

The present invention also relates to a liquid crystal display element or a liquid crystal display comprising any one of the above-mentioned cholesteric phase liquid crystal compositions; the display element or the display is an active matrix display element or the display or a passive matrix display element or the display.

The cholesteric liquid crystal display element or cholesteric liquid crystal display of the present invention is preferably an active matrix addressed liquid crystal display element or liquid crystal display.

The liquid crystal display element or liquid crystal display comprising the cholesteric phase liquid crystal composition of the present invention has the characteristics of high charge retention rate (VHR) and excellent reliability performance, and can effectively improve the edge drive failure of the liquid crystal display element or liquid crystal display and the screen flickering problem caused by low-frequency drive.

In order to explain the present invention more clearly, the present invention is further described below in conjunction with the 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, the preparation methods are conventional methods. The raw materials used can be obtained from public commercial channels unless otherwise specified. The percentages are all mass percentages. The temperature is in degrees Celsius (℃). The specific meanings of other symbols and the test conditions are as follows: Cp represents the clearing point of the liquid crystal (℃), tested by DSC quantitative method; SN represents the melting point of the liquid crystal from the crystalline state to the nematic phase (℃); Δn represents optical anisotropy, n _o is the refractive index of ordinary light, _ne is the refractive index of extraordinary light, and the test conditions are 25±2℃, 589nm, and Abbe refractometer test; Δε represents dielectric anisotropy, Δε=ε _∥ -ε _⊥ , where ε _∥ is the dielectric constant parallel to the molecular axis, ε _⊥ is the dielectric constant perpendicular to the molecular axis, and the test conditions are 25±0.5 ℃, 20 micron vertical box, INSTEC: ALCT-IR1 test; γ ₁ is the rotational viscosity (mPa·s), and the test conditions are 25±0.5 ℃, 20 micron vertical box, INSTEC: ALCT-IR1 test; K ₁₁ is the splay elastic constant, K ₃₃ is the bending elastic constant, and the test conditions are: 25 ℃, INSTEC: ALCT-IR1, 20 micron vertical box; VHR is the voltage holding rate (%), and the test conditions are 60±1 ℃, voltage is ±5V, pulse width is 10ms, and voltage holding time is 1.667ms. The testing equipment is TOYO Model 6254 liquid crystal performance comprehensive tester; the preparation method of the cholesteric phase liquid crystal composition is as follows: each liquid crystal monomer and chiral agent are 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 cholesteric phase liquid crystal monomer structure of the disclosed embodiment 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 P Py M G Gi U K A D

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- _{-OCnH2n +1} -On _-CF2O- -Q- _-CH2O- -O- -O- -B- -F -F -CN -CN -CH=CH- -V- -C≡C- -W- -COO- -Z- -CH=CH-C _n H _2n+1 —Vn Cp- Cpr- Cpr1-

For example: Its code is CZP-3-CN; , its code is CC-3-V; , its code is CP-3-O2; , its code is PP-5-CN; Its code is PyG-5-CN; , whose code is CCP-V-1; , its code is CCU-2-F; , whose code is CPWP-3-2; Its code is UWPP-2-3 , its code is CCPU-3-F; , its code is PPGU-Cp-F; , its code is DUQU-Cp-F; , its code is PGUQU-3-F.

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 corresponding properties Category Liquid crystal unit code Content (%) Ⅰ PWPU-3-F 6 Ⅰ PWPU-5-F 4 Ⅱ PUQU-3-F 6 Ⅱ PUQU-Cp-F 7 Ⅱ PGUQU-3-F 3 III CC-3-V 5 III CCP-V-1 2 IV UWPP-2-3 6 IV UWPP-3-2 8 IV UWPP-3-4 8 IV UWPP-4-3 8 Ⅴ PyU-3-CN 5 Ⅴ CP-3-CN 5 Ⅴ CP-5-CN 5 Ⅴ PZG-2-CN 5 Ⅴ PZG-3-CN 4 Ⅴ PGP-V2-CN 5 Ⅴ PGP-3-CN 8 VII VII-2 3.6 Δε[1KHz, 25 ℃]：22.09 Δn[589nm, 25 ℃]：0.233 K ₁₁ ：12.4 K ₃₃ ：13.9 Cp：92 ℃ γ ₁ ：80.4 mPa.s γ _1/ K ₁₁ ：6.73 VHR：99.0 % 25 ℃：no crystal precipitation Placed at -20 ℃ for 480h：no crystal precipitation Reflection wavelength 450nm The sample was placed at high temperature 60 ℃ and 60 ℃&90 %RH for 30 days respectively and the drive was normal

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 corresponding properties Category Liquid crystal unit code Content (%) Category Liquid crystal unit code Content (%) Ⅰ PWPU-3-F 4 Ⅰ PWPU-5-F 5 Ⅱ PUQU-3-F 4 Ⅱ PUQU-Cp-F 8 Ⅱ PUQU-Cp-F 6 III CC-3-V 5 III CCP-V-1 4 IV UWPP-2-3 4 IV UWPP-3-2 8 IV UWPP-3-4 6 IV UWPP-4-3 8 Ⅴ PyU-3-CN 3 Ⅴ CP-3-CN 3 Ⅴ CP-5-CN 3 Ⅴ PZG-2-CN 5 Ⅴ PZG-3-CN 5 Ⅴ PGP-V2-CN 7 Ⅴ PGP-3-CN 8 VI CP-3-F 4 VIII Ⅷ-1 4.2 Δε[1KHz, 25 ℃]：21.3 Δn[589nm, 25 ℃]：0.232 K ₁₁ ：11.7 K ₃₃ ：12.4 Cp：87 ℃ γ ₁ ：81.1mPa.s γ _1/ K ₁₁ ：6.91 VHR：98.6 % 25 ℃：no crystal precipitation Placed at -20 ℃ for 480 hours：no crystal precipitation Reflection wavelength 525nm The sample was placed at high temperature 60 ℃ and 60 ℃&90 %RH for 30 days respectively and the drive was normal

Embodiment 3

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

Table 5 Formulation of the liquid crystal composition of Example 3 and corresponding properties Category Liquid crystal unit code Content (%) Ⅰ PWPU-3-F 6 Ⅰ PWPU-5-F 6 Ⅱ PUQU-3-F 6 Ⅱ PUQU-Cp-F 4 Ⅱ PGUQU-4-F 4 III CC-3-V 3 IV PWP-3-O2 6 IV UWPP-2-3 9 IV UWPP-3-2 8 IV UWPP-3-4 8 IV UWPP-4-3 8 Ⅴ CP-3-CN 5 Ⅴ CP-5-CN 5 Ⅴ PZG-2-CN 3 Ⅴ PZG-3-CN 3 Ⅴ PZU-3-CN 4 Ⅴ PZU-5-CN 4 Ⅴ CPZG-2-CN 3 VI PGU-2-F 2 VI CP-O2-F 3 VII VII-2 2.3 Δε[1KHz, 25 ℃]：21.0 Δn[589nm, 25 ℃]：0.236 K ₁₁ ：12.4 K ₃₃ ：12.4 Cp：87 ℃ γ ₁ ：83.6 mPa.s γ _1/ K ₁₁ ：6.75 VHR：97.5 % 25 ℃：no crystal precipitation Placed at -20 ℃ for 480 hours：no crystal precipitation Reflection wavelength 600nm The sample was placed at high temperature 60 ℃ and 60 ℃&90 %RH for 30 days respectively and the drive was normal

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 PWPU-3-F 6 Ⅰ PWPU-5-F 5 Ⅱ PUQU-3-F 6 Ⅱ PUQU-3Cpr-F 6 Ⅱ PGUQU-3-F 2 Ⅱ PGUQU-4-F 1 III CCP-V-1 3 III CC-3-V 5 IV UWPP-2-3 8 IV UWPP-3-2 8 IV UWPP-3-4 8 IV UWPP-4-3 8 Ⅴ CP-3-CN 3 Ⅴ CP-5-CN 3 Ⅴ PZG-2-CN 5 Ⅴ PZG-3-CN 5 Ⅴ PGP-V2-CN 7 Ⅴ PGP-5-CN 8 VI CP-O2-F 3 VII VII-2 1.9 Δε[1KHz, 25 ℃]：21.0 Δn[589nm, 25 ℃]：0.234 K ₁₁ ：12.4 K ₃₃ ：12.4 Cp：87 ℃ γ ₁ ：82.6 mPa.s γ _1/ K ₁₁ ：6.75 VHR：98.9 % 25 ℃：no crystal precipitation Placed at -20 ℃ for 480 hours：no crystal precipitation Reflection wavelength 620nm The sample was placed at high temperature 60 ℃ and 60 ℃&90 %RH for 30 days respectively and the drive was normal

Comparative Example 1

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

Table 7 Formula and corresponding properties of the liquid crystal composition of Comparative Example 1 Category Liquid crystal unit code Content (%) Ⅴ PP-5-CN 10 Ⅴ CP-3-CN 8 Ⅴ CP-5-CN 6 Ⅴ PP-4-CN 10 Ⅴ PP-O2-CN 10 Ⅴ PP-O5-CN 5 Ⅴ PP-O8-CN 10 Ⅴ PZP-2-CN 10 Ⅴ PZPP-N-CN 5 Ⅴ CZPP-2-CN 9 Ⅴ CZPP-3-CN 7 Ⅴ CZPP-5-CN 10 VII VII-2 3.5 Δε[1KHz, 25 ℃]：23.2 Δn[589nm, 25 ℃]：0.200 K ₁₁ ：8.7 K ₃₃ ：116.9 Cp：80 ℃ γ ₁ ：97.4 mPa.s γ _1/ K ₁₁ ：11.2 VHR：67.6 % 25 ℃：No crystal precipitation Placed at -20 ℃ for 480h: Crystal precipitation with reflection wavelength of 450nm The sample was placed at high temperature of 60 ℃ and at 60 ℃&90 %RH for 30 days respectively. The driving was abnormal, and a frame appeared and it could not be driven.

Comparative Example 2

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 2 Category Liquid crystal unit code Content (%) Ⅴ PZG-2-CN 7 Ⅴ PZG-4-CN 12 Ⅴ PZG-3-CN 8 Ⅴ PZG-5-CN 12 Ⅴ CPZG-4-CN 5 Ⅴ CPZG-5-CN 5 Ⅴ CCP-5-F 2 CCZPC-3-3 3 CCZPC-3-4 2 IV UWPP-2-3 20 IV UWPP-3-4 twenty four VIII 4.2 Δε[1KHz, 25 ℃]：22.9 Δn[589nm, 25 ℃]：0.245 K ₁₁ ：15.4 K ₃₃ ：14.2 Cp：110 ℃ γ ₁ ：140.1mPa.s γ _1/ K ₁₁ ：9.10 VHR：66.3 % 25 ℃：No crystal precipitation Placed at -40 ℃ for 480h: Crystal precipitation with reflection wavelength of 520nm The sample was placed at high temperature of 60 ℃ and at 60 ℃&90 %RH for 30 days respectively. The driving was abnormal, and a frame appeared and it could not be driven.

60℃&90%RH means: environment with high temperature of 60℃ and humidity of 90%.

Comparative Examples 1 and 2 are both comparative examples of the present embodiment. Compared with the embodiment, although the technical solutions of Comparative Examples 1 and 2 can also be adjusted to parameters such as refractive index and dielectric constant equivalent to those of the present invention, the VHR and reliability of Comparative Examples 1 and 2 are poor; both cannot pass the high temperature and high humidity reliability test, and a serious display problem of the frame being unable to be driven occurs, which cannot be repaired.

Obviously, the above embodiments disclosed in the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. 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 solution of the present invention are still within the scope of protection of the present invention.

Claims (8)

A liquid crystal composition comprising one or more compounds of formula I, one or more compounds of formula II, one or more compounds of formula III and one or more compounds of formula IV-1, Ⅰ Ⅱ III IV-1 wherein _R1 , _R2 , _R3 , _R5 and _R6 each independently represent H, F, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 6 carbon atoms substituted with fluorine, an alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms substituted with fluorine, an alkenyl group having 2 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms substituted with fluorine, an alkenyloxy group having 3 to 8 carbon atoms or an alkenyloxy group having 3 to 8 carbon atoms substituted with fluorine, and any one or more _-CH2- groups in the groups represented by _R1 , _R2 , _R3 , _R5 and _R6 are optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene; _X1 , _X2 , _X3 , _X4 , _X5 , _X6 , X7 are _X7 , _X8 , _X11 , and _X12 each independently represent H or F, and _X1 and _X2 do not simultaneously represent F; m and n each independently represent 0, 1, or 2, and m+n≥1; k represents 1, 2, or 3; m´ represents 1 or 2; , , , Each independently expresses , , , , , or ; express , , , , , or ; The mass content of the compound represented by formula I in the liquid crystal composition is 6-20%; the mass content of the compound represented by formula II in the liquid crystal composition is 5-26%; the mass content of the compound represented by formula III in the liquid crystal composition is 2-20%; the mass content of the compound represented by formula IV-1 in the liquid crystal composition is 10-45%. The liquid crystal composition according to claim 1 further comprises one or more compounds represented by formula V, Ⅴ wherein, _R4 represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more _-CH2- in the group represented by _R4 is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene; _Z1 represents a single bond or -COO-; _X9 and _X10 each independently represent H or F; p represents 1 or 2; express , , , , , or . The liquid crystal composition according to claim 1 further comprises one or more compounds represented by formula VI, VI wherein, _R7 independently represents H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more _-CH2- in the group represented by _R7 is optionally replaced by cyclopentylene, cyclobutylene or cyclopropylene; _X13 and _X14 independently represent H or F; nˊ represents 1 or 2; express , or . The liquid crystal composition according to claim 1 further comprises one or more chiral active substances selected from the group consisting of compounds represented by formula VII, formula VIII and formula IX, VII VIII IX R ₈ , R ₉ , R ₁₀ , and R ₁₁ each independently represent H, F, an alkyl group having 1-6 carbon atoms, an alkyl group having 1-6 carbon atoms substituted with fluorine, an alkoxy group having 1-6 carbon atoms, an alkoxy group having 1-6 carbon atoms substituted with fluorine, an alkenyl group having 2-6 carbon atoms, an alkenyl group having 2-6 carbon atoms substituted with fluorine, an alkenyloxy group having 3-8 carbon atoms, or an alkenyloxy group having 3-8 carbon atoms substituted with fluorine; and any one or more -CH ₂ - in the groups represented by R ₈ , R ₉ , R ₁₀ , and R ₁₁ is optionally replaced by cyclopentylene, cyclobutylene, or cyclopropylene; X ₁₅ and X ₁₆ each independently represent H or F; at least one of them is F; q represents 1 or 2; express , , or . A cholesteric liquid crystal display element comprises the liquid crystal composition described in any one of claims 1 to 4, wherein the cholesteric liquid crystal display element is an active matrix addressing display element or a passive matrix addressing display element. According to the cholesteric liquid crystal display element described in claim 5, the active matrix addressing display element includes three stacked glass substrates of blue, green and red. A liquid crystal composition according to any one of claims 1 to 4, wherein the liquid crystal composition is used in a cholesteric liquid crystal display, and the cholesteric liquid crystal display is an active matrix addressed display or a passive matrix addressed display. The liquid crystal composition according to claim 7, wherein the active matrix addressing display comprises three stacked glass substrates of blue, green and red.