TW202307181A - Positive dielectric anisotropy liquid crystal compound, liquid crystal composition and liquid crystal display device - Google Patents

Abstract

The invention relates to a positive dielectric anisotropy liquid crystal compound, a liquid crystal composition and a liquid crystal display device. The liquid crystal compound disclosed by the invention is a liquid crystal compound shown in a following formula I in the specification. A reduced G1/K11 value can be obtained on the basis of maintaining proper optical anisotropy value, dielectric anisotropy and K33/K11 value, so that the response time can be reduced, and quick response can be realized.

Description

Positive dielectric anisotropy liquid crystal compound, liquid crystal composition and liquid crystal display device

The invention relates to the technical field of liquid crystal display materials. More specifically, it relates to a liquid crystal composition with positive dielectric anisotropy and a liquid crystal display device.

At present, the application range of liquid crystal compounds is expanding more and more widely, and it can be applied to various types of displays, electro-optical devices, sensors, etc., such as televisions, mobile phones, industrial control displays, and vehicle displays. There are various types of liquid crystal compounds used in the above-mentioned display fields, among which nematic liquid crystals are most widely used. Nematic liquid crystals have been used in passive TN, STN matrix displays and systems with TFT active matrix.

For the application field of thin film transistor technology (TFT-LCD), although the market has been huge in recent years and the technology has gradually matured, people's requirements for display technology are also constantly improving, especially in achieving fast response and reducing driving voltage to reduce power consumption etc. As one of the important optoelectronic materials of liquid crystal display, liquid crystal material plays an important role in improving the performance of liquid crystal display.

For liquid crystal compositions, how to obtain a reduced response time on the basis of maintaining appropriate optical anisotropy values, dielectric anisotropy, and K ₃₃ /K ₁₁ values is an urgent problem to be solved in this field.

One aspect of the present invention provides a novel liquid crystal compound with positive dielectric anisotropy. By using the liquid crystal compound of the present invention in a liquid crystal composition, it can maintain a suitable optical anisotropy value, dielectric anisotropy, K ₃₃ A reduced G ₁ /K ₁₁ value is obtained on the basis of the /K ₁₁ value, so that a fast response can be obtained on the basis of maintaining a suitable optical anisotropy value, dielectric anisotropy, and K ₃₃ /K ₁₁ value.

In another aspect, the present invention provides a liquid crystal composition, which can maintain a suitable optical anisotropy value, dielectric anisotropy, and K ₃₃ /K ₁₁ value by containing the aforementioned liquid crystal compound of the present invention. Get a quick response. Furthermore, the liquid crystal composition also has an increased VHR value, so that defects such as afterimages in the final display can be overcome or reduced.

Another aspect of the present invention provides a liquid crystal display device, which has a fast response time by containing the liquid crystal compound of the present invention. Furthermore, since the liquid crystal display device of the present invention adopts a liquid crystal composition with a high VHR value, defects such as afterimages are reduced, and thus the display advantages of reduced power consumption and improved stability can be obtained.

The present invention includes the following technical solutions.

I On the one hand, the present invention provides a novel positive dielectric anisotropy liquid crystal compound, which is a liquid crystal compound represented by the following formula I:

I

Wherein, _R represents H, an alkyl group with 1 to 8 carbon atoms, or an alkenyl group with 2 to 8 carbon atoms, wherein optionally 4 or less Hs are substituted by F;

R ₂ represents H, F, an alkyl group with 1 to 8 carbon atoms or an alkenyl group with 2 to 8 carbon atoms, in which one or two non-adjacent -CH ₂ - are optionally substituted by -O- , optional up to 4 H are replaced by F;

m is 1 or 2;

n is selected from 1, 2, 3 or 4;

o is 1 or 2;

Z ₁ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O- or -COO-, wherein in -C ₂ H ₄ - optionally 0~4 H are replaced by F;

Z ₂ represents a single bond, -CF ₂ O- or -COO-;

Ring A, ring B, and ring C each independently represent a group consisting of groups selected from the group consisting of 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl-1 ,4-cyclohexylene, 2-oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl , 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1,4 -phenylene, 2,3-bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3-bis (Trifluoromethoxy)-1,4-phenylene, 2,6-difluoro-substituted-1,4-phenylene, 2,5-difluoro-substituted-1,4-phenylene, 2- Fluoro-6-trifluoromethyl-1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1, 4-phenylene, 2-fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5- Bis(trifluoromethyl)-1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy)- 1,4-phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene, 2-trifluoromethyl-5-trifluoromethoxy-1,4- phenylene.

In another aspect, the present invention provides a liquid crystal composition comprising the aforementioned liquid crystal compound of the present invention.

In another aspect, the present invention provides a liquid crystal display device, which contains the aforementioned liquid crystal compound of the present invention, or the aforementioned liquid crystal composition of the present invention; the liquid crystal display device is an active matrix display device, or a passive matrix display device .

Invention effect

The beneficial effect of the present invention is that, compared with the prior art, by using the positive dielectric anisotropy liquid crystal compound of the present invention in the liquid crystal composition, it is possible to maintain a suitable optical anisotropy value, dielectric anisotropy, K33 A reduced G1/K11 value is obtained on the basis of the /K11 value, thereby obtaining a fast response. In addition, by including the aforementioned liquid crystal compound of the present invention in the liquid crystal composition of the present invention, it has a high VHR after being irradiated with UV light, thereby being able to overcome/reduce defects such as afterimages in the final display device.

[Liquid crystal compound]

I The novel positive dielectric anisotropy liquid crystal compound of the present invention is a liquid crystal compound shown in the following formula I:

I

Wherein, _R represents H, an alkyl group with 1 to 8 carbon atoms, or an alkenyl group with 2 to 8 carbon atoms, wherein optionally 4 or less Hs are substituted by F;

R ₂ represents H, F, an alkyl group with 1 to 8 carbon atoms or an alkenyl group with 2 to 8 carbon atoms, in which one or two non-adjacent -CH ₂ - are optionally substituted by -O- , optional up to 4 H are replaced by F;

m is 1 or 2;

n is selected from 1, 2, 3 or 4;

o is 1 or 2;

Z ₁ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O- or -COO-, wherein in -C ₂ H ₄ - optionally 0~4 H are replaced by F;

Z ₂ represents a single bond, -CF ₂ O- or -COO-;

Ring A, ring B, and ring C each independently represent a group consisting of groups selected from the group consisting of 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl-1 ,4-cyclohexylene, 2-oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl , 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1,4 -phenylene, 2,3-bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3-bis (Trifluoromethoxy)-1,4-phenylene, 2,6-difluoro-substituted-1,4-phenylene, 2,5-difluoro-substituted-1,4-phenylene, 2- Fluoro-6-trifluoromethyl-1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1, 4-phenylene, 2-fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5- Bis(trifluoromethyl)-1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy)- 1,4-phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene, 2-trifluoromethyl-5-trifluoromethoxy-1,4- phenylene.

、

The aforementioned 2-fluoro-1,4-phenylene represents the following two divalent groups, in which the fluorine substituent may be on the left side or on the right side.

,

、

2-methyl-1,4-cyclohexylene represents the following two divalent groups:

,

This rule also applies to other similar groups.

The "alkyl group having 1 to 8 carbon atoms" represented by the aforementioned _R1 may be a straight-chain alkyl group, a branched-chain alkyl group or a cyclic alkyl group, such as methyl, ethyl, n-propyl , isopropyl, cyclopropyl, cyclopentyl, n-butyl, isobutyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, cyclopentyl, hexyl, heptyl, octyl, etc.

The "alkenyl group having 2 to 8 carbon atoms" represented by the aforementioned _R1 may be a straight-chain alkenyl group, a branched-chain alkenyl group, or an alkenyl group with a cyclic alkyl chain, and is not particularly limited. Examples include vinyl, propenyl, butenyl, 2-methylpropenyl, 1-pentenyl, 2-pentenyl, 2-methyl-1-butenyl, 3-methyl-1 -butenyl, 2-methyl-2-butenyl, pentenyl, hexenyl, heptenyl and the like.

Among the aforementioned "alkyl groups with 1 to 8 carbon atoms" and "alkenyl groups with 2 to 8 carbon atoms", optional 4 or less Hs are substituted by F, for example, optional 0, 1, 2, 3 or 4 H are replaced by F. For example, when the methyl group represented by R ₁ is substituted by F, it may be -CH ₂ F, -CHF ₂ , or -CF ₃ , for example. The groups obtained by substituting other groups with F are also similar to the above, and detailed descriptions are omitted here.

The "alkyl group having 1 to 8 carbon atoms" represented by the aforementioned _R2 may be a straight-chain alkyl group, a branched-chain alkyl group or a cyclic alkyl group, such as methyl, ethyl, n-propyl , isopropyl, cyclopropyl, cyclopentyl, n-butyl, isobutyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, cyclopentyl, hexyl, heptyl, octyl, etc.

The "alkenyl group having 2 to 8 carbon atoms" represented by the aforementioned _R2 may be a straight-chain alkenyl group, a branched-chain alkenyl group, or an alkenyl group with a cyclic alkyl chain, and is not particularly limited. Examples include vinyl, propenyl, butenyl, 2-methylpropenyl, 1-pentenyl, 2-pentenyl, 2-methyl-1-butenyl, 3-methyl-1 -butenyl, 2-methyl-2-butenyl, pentenyl, hexenyl, heptenyl and the like.

Among the "alkyl groups with 1 to 8 carbon atoms" and "alkenyl groups with 2 to 8 carbon atoms" represented by the aforementioned R ₂ , one or two non-adjacent -CH ₂ -any Election is replaced by -O-. For example, when R ₂ represents -CH ₂ CH ₃ , the group obtained by substituting -CH ₂ - with O is -OCH ₃ , and when R ₂ represents -CH ₂ CH ₂ CH ₃ , one of The group obtained after -CH ₂ - is replaced by O is -OCH ₂ CH ₃ , and so on, which will not be listed here.

The "alkyl with 1 to 8 carbon atoms" and "alkenyl with 2 to 8 carbon atoms" represented by the aforementioned R ₂ and one or two non-adjacent -CH ₂ -optionally- The group obtained by O-substitution, further optional up to 4 Hs are substituted by F. For example, when R ₂ represents -CH ₃ , the groups obtained after 1 to 3 Hs are replaced by F are -CH ₂ F, -CHF ₂ , -CF ₃ , and R ₂ represents the case of -OCH ₃ Below, the groups obtained after 1~3 H are replaced by F are -OCH ₂ F, -OCHF ₂ , -OCF ₃ .

Preferably, R ₂ represents H, F, -CH ₂ F, -CHF ₂ , -CF ₃ , -OCH ₂ F, -OCHF ₂ , or -OCF ₃ . More preferably, it represents F, -OCH ₂ F, or -OCF ₃ .

The positive dielectric anisotropy liquid crystal compound of the present invention has the structure shown in the aforementioned formula I, so that it can maintain a suitable optical anisotropy value, dielectric anisotropy, and K ₃₃ /K ₁₁ value on the basis of A reduced G ₁ /K ₁₁ value is obtained to obtain a fast response, thereby reducing the response time when used in a liquid crystal composition, which is beneficial to realize a fast response.

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

I-14

I-15

I-16

I-17

I-18

I-19

I-20

I-21

I-22

I-23

I-24

I-25

I-26

I-27

I-28

I-29

I-30

I-31

I-32

I-33

I-34

I-35

I-36 Preferably, the liquid crystal compound represented by the aforementioned formula I is selected from the group consisting of compounds represented by the following formulas I-1 to I-36:

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

I-14

I-15

I-16

I-17

I-18

I-19

I-20

I-21

I-22

I-23

I-24

I-25

I-26

I-27

I-28

I-29

I-30

I-31

I-32

I-33

I-34

I-35

I-36

Wherein, the definitions of R ₁ and R ₂ are the same as above.

[Synthesis of liquid crystal compounds with positive dielectric anisotropy]

The synthesis method of the positive dielectric anisotropy liquid crystal compound of the present invention will be described below.

The compound represented by formula I can be synthesized by combining organic synthetic chemistry methods. For example, in the case of a compound having a -CH=CH-CH ₂ -CH ₂ - structure, the -CH=CH-CH ₂ -CH ₂ - structure can be synthesized as follows:

The organic bromide (a1) with at least one ring structure is reacted with p-bromophenylpropionaldehyde ethylene acetal to obtain the compound (a2) in which the aforementioned ring structure is connected with propionaldehyde acetal. The compound (a2) is hydrolyzed with formic acid, and the propionaldehyde acetal of the compound (a2) is hydrolyzed to generate the compound (a3) with propionaldehyde attached to the ring structure. The aforementioned compound (a3) is further reacted with methyl iodide phosphonium salt (such as 4-vinylcyclohexyl methyl iodide phosphonium salt) in a system containing potassium tert-butoxide and THF to obtain a compound with -CH=CH-CH ₂ -CH ₂ - Structure of compound (a4). The aforementioned reaction scheme is shown in the following reaction scheme 1.

反應流程圖1 According to needs, the 4-vinylcyclohexyl iodomethane phosphonium salt can be replaced by other iodomethane phosphonium salts to obtain -CH=CH-CH ₂ -CH ₂ -compounds linked with different structures.

Reaction Flow Chart 1

(2) Synthesis Example 1

The synthetic route of the compound represented by the aforementioned formula A-6 is shown in the above synthetic route diagram. Specifically, trifluorophenylboronic acid reacts with 2-fluoro-4-bromoiodobenzene in a reaction system containing tetrahydrofuran, sodium carbonate and tetrakis(triphenylphosphine)palladium under stirring and heating under reflux conditions to generate formula A- Compounds shown in 1. Next, the compound represented by formula A-1 was reacted with triisopropyl borate in the presence of butyllithium n-hexane and THF in anhydrous tetrahydrofuran to produce the compound represented by formula A-2. Then, the compound shown in formula A-2 reacts with p-bromophenylpropionaldehyde ethylene acetal under the effect of catalyst bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride to generate the compound shown in formula A-3 compound of. The compound represented by formula A-3 is hydrolyzed in a system containing formic acid to obtain the compound represented by formula A-4. The compound represented by formula A-4 is further reacted with 4-vinylcyclohexyl iodomethanephosphonium salt in a system containing potassium tert-butoxide and THF to obtain the compound represented by A-5. Then, the compound represented by the aforementioned formula A-5 was heated in a system containing toluene, sodium benzenesulfinate, and concentrated hydrochloric acid to cause configuration inversion to obtain the compound represented by A-6.

(2) Synthesis Example 2

Preparation of CVEPUQU-V-F

The synthetic route of the compound represented by the aforementioned formula B-6 is shown in the above synthetic route diagram.

Specifically, the compound shown in formula B-1 reacts with triisopropyl borate in the presence of anhydrous tetrahydrofuran and butyl lithium n-hexane to obtain the compound shown in formula B-2, and then, the compound shown in formula B-2 The compound reacts with p-bromophenylpropionaldehyde ethylene acetal in the presence of catalyst bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride to generate the compound shown in formula B-3. The compound represented by formula B-3 is hydrolyzed in the presence of formic acid to obtain the compound represented by formula B-4. The compound represented by formula B-4 is reacted with 4-vinylcyclohexyl iodide methanephosphonium salt in the presence of potassium tert-butoxide and THF to obtain the compound represented by formula B-5 including E and Z configurations. Then, the compound represented by the aforementioned formula B-5 was heated in a system containing toluene, sodium benzenesulfinate, and concentrated hydrochloric acid to cause configuration inversion to obtain the compound represented by B-6.

For the synthesis of other structures of the liquid crystal compound of the present invention, those skilled in the art can select appropriate synthesis routes and conditions for preparation as required.

[Liquid Crystal Composition]

The liquid crystal composition of the present invention contains the liquid crystal compound represented by the aforementioned formula I.

The liquid crystal composition of the present invention may contain one or two or more liquid crystal compounds represented by formula I. In the liquid crystal composition of the present invention, only the liquid crystal compound represented by formula I may be contained as the liquid crystal compound component. In the composition of the present invention, the compound represented by formula I can be contained in the range of, for example, 1 to 99% by mass.

The liquid crystal composition of the present invention is a liquid crystal composition with positive dielectric anisotropy.

By using the liquid crystal compound represented by the formula I of the present invention in the liquid _crystal composition of the present invention, a _reduced G ₁ /K ₁₁ value, so as to obtain a fast response. Furthermore, the liquid crystal composition of the present invention also has an improved VHR value, thereby reducing/eliminating defects such as afterimages of liquid crystal display devices.

In addition to the liquid crystal compound represented by the aforementioned formula I, the liquid crystal composition of the present invention may contain other liquid crystal compounds. As other liquid crystal compounds that may be contained, they may have positive dielectric anisotropy or negative dielectric anisotropy.

In some embodiments of the liquid crystal composition of the present invention, preferably, it also includes:

At least one compound represented by formula II;

At least one compound represented by formula III: and,

Ⅱ

III

IV At least one compound shown in formula IV:

II

III

IV

in,

R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ each independently represent an alkyl group with 1 to 5 carbon atoms, an alkoxy group with 1 to 5 carbon atoms, and an alkoxy group with 2 to 5 carbon atoms. 5 alkenyl groups, or alkenyloxy groups with 3 to 5 carbon atoms; H on any carbon atom in R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ is independently optionally substituted by F , one or two non-adjacent -CH ₂ - are optionally replaced by -O-;

Z ₃ represents a single bond or -CH ₂ O-;

Z ₄ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O- or -COO-, wherein in -C ₂ H ₄ - optionally 0~4 H are replaced by F;

s is selected from 1, 2, 3 or 4;

p represents 0, 1, 2 or 3;

q, r, v each independently represent 0, 1 or 2;

Ring A1, Ring A2, Ring A3, Ring A4, Ring A5, and Ring A6 each independently represent a group consisting of groups selected from the group consisting of: 1,4-cyclohexylene, 1-methyl-1,4- Cyclohexyl, 2-methyl-1,4-cyclohexylene, 2-oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclo Hexene-1,4-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3 -Trifluoromethyl-1,4-phenylene, 2,3-bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4- Phenylene, 2,3-bis(trifluoromethoxy)-1,4-phenylene, 2,6-difluoro-1,4-phenylene, 2,5-difluoro-1 ,4-phenylene, 2-fluoro-6-trifluoromethyl-1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6 -Trifluoromethoxy-1,4-phenylene, 2-fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4 -phenylene, 2,5-bis(trifluoromethyl)-1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5- Bis(trifluoromethoxy)-1,4-phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene, 2-trifluoromethyl-5-tri Fluoromethoxy-1,4-phenylene.

R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ each independently represent an alkyl group with 1 to 5 carbon atoms, an alkoxy group with 1 to 5 carbon atoms, and an alkoxy group with 2 to 5 carbon atoms. 5 alkenyl groups, or alkenyloxy groups with 3 to 5 carbon atoms; H on any carbon atom in R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ is independently optionally substituted by F , one or two non-adjacent -CH ₂ - are optionally replaced by -O-.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ₃ , R ₄ , R ₅ , R ₆ , R ₇ or R ₈ include, for example, methyl, ethyl, n-propyl, isopropyl straight-chain or branched-chain alkyl groups such as n-butyl, isobutyl, tert-butyl, n-pentyl, and isopentyl, or cycloalkyls such as cyclopropyl, cyclobutyl, and cyclopentyl.

Examples of the "alkoxy group having 1 to 5 carbon atoms" represented by R ₃ , R ₄ , R ₅ , R ₆ , R ₇ or R ₈ include methoxy, ethoxy, n- Propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, isopentyloxy, or cyclopropoxy, cyclopentyloxy, cyclobutoxy, etc. Cycloalkoxy.

Examples of the "alkenyl group having 2 to 5 carbon atoms" represented by R ₃ , R ₄ , R ₅ , R ₆ , R ₇ or R ₈ include vinyl, propenyl, butenyl, 2 -Methacryl, 1-pentenyl, 2-pentenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 2-methyl-2-butenyl wait.

Examples of the "alkenyloxy group having 3 to 5 carbon atoms" represented by R ₃ , R ₄ , R ₅ , R ₆ , R ₇ or R ₈ include ethyleneoxy, propyleneoxy, butene Oxygen, 2-methacryloxy, 1-pentenyloxy, 2-pentenyloxy, 2-methyl-1-butenyloxy, 3-methyl-1-butenyloxy, 2 -Methyl-2-butenyloxy and the like.

R ₃ , R ₄ , R ₅ , R ₆ , R ₇ or R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkoxy group having 2 carbon atoms In an alkenyl group with ∼5 carbon atoms or an alkenyloxy group with 3 to 5 carbon atoms, H on any carbon atom in these groups is independently optionally substituted by F, and in addition, one or both of these groups Non-adjacent -CH ₂ -s are optionally substituted by -O-.

Z ₃ represents a single bond or -CH ₂ O-.

Z ₄ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O- or -COO-, wherein, in -C ₂ H ₄ -, optionally 0 to 4 Hs are replaced by F. A group obtained by substituting -C ₂ H ₄ - with F includes, for example, -CH ₂ CHF-, -CH ₂ CF ₂ -, -CHFCF ₂ -, or -CF ₂ CF ₂ -.

Ⅱ-1

Ⅱ-2

Ⅱ-3

Ⅱ-4

Ⅱ-5

Ⅱ-6

Ⅱ-7

Ⅱ-8

Ⅱ-9

Ⅱ-10 In the aforementioned positive dielectric anisotropy liquid crystal composition, preferably, the compound represented by the aforementioned formula II is selected from the group consisting of compounds represented by the following formulas II-1 to II-10.

Ⅱ-1

Ⅱ-2

Ⅱ-3

Ⅱ-4

Ⅱ-5

Ⅱ-6

II-7

Ⅱ-8

Ⅱ-9

Ⅱ-10

F或H。 The definitions of R ₃ and R ₄ are the same as above, and (F) means

F or H.

Preferably, _R3 is a linear alkyl group with 1 to 5 carbon atoms or an alkenyl group with 2 to 5 carbon atoms. Examples of straight-chain alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl and the like. Examples of the alkenyl group having 2 to 5 carbon atoms include vinyl, propenyl, butenyl, pentenyl and the like.

R ₄ is preferably a linear alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms. Examples of straight-chain alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl and the like. Examples of the alkenyl group having 2 to 5 carbon atoms include vinyl, propenyl, butenyl, pentenyl and the like.

Ⅲ-1

Ⅲ-2

Ⅲ-3

Ⅲ-4

Ⅲ-5

Ⅲ-6

Ⅲ-7

Ⅲ-8

Ⅲ-9

Ⅲ-10

Ⅲ-11

Ⅲ-12

Ⅲ-13

Ⅲ-14

Ⅲ-15

Ⅲ-16

Ⅲ-17

Ⅲ-18

Ⅲ-19

Ⅲ-20

Ⅲ-21 In the aforementioned positive dielectric anisotropy liquid crystal composition, preferably, the compound represented by the aforementioned formula III is selected from the group consisting of the compounds represented by the following formulas III-1 to III-21.

Ⅲ-1

Ⅲ-2

III-3

III-4

III-5

III-6

III-7

III-8

III-9

III-10

III-11

III-12

III-13

III-14

III-15

III-16

III-17

III-18

III-19

III-20

III-21

The definitions of R ₅ and R ₆ are the same as above.

IV-1

IV-2

IV-3

IV-4

IV-5

IV-6

IV-7

IV-8

IV-9

IV-10

IV-11

IV-12

IV-13

IV-14

IV-15

IV-16

IV-17

IV-18

IV-19

IV-20

IV-21

IV-22

IV-23

IV-24

IV-25

IV-26

IV-27

IV-28

IV-29

IV-30

IV-31

IV-32

IV-33

IV-34

IV-35

IV-36

IV-37

IV-38

IV-39

IV-40

IV-41

IV-42

IV-43

IV-44 In the aforementioned positive dielectric anisotropy liquid crystal composition, preferably, the compound represented by the aforementioned formula IV is selected from the group consisting of the compounds represented by the following formulas IV-1 to IV-44.

IV-1

IV-2

IV-3

IV-4

IV-5

IV-6

IV-7

IV-8

IV-9

IV-10

IV-11

IV-12

IV-13

IV-14

IV-15

IV-16

IV-17

IV-18

IV-19

IV-20

IV-21

IV-22

IV-23

IV-24

IV-25

IV-26

IV-27

IV-28

IV-29

IV-30

IV-31

IV-32

IV-33

IV-34

IV-35

IV-36

IV-37

IV-38

IV-39

IV-40

IV-41

IV-42

IV-43

IV-44

The definitions of R ₇ and R ₈ are the same as above.

Preferably, R ₇ represents an alkyl group with 1 to 5 carbon atoms or an alkoxy group with 1 to 5 carbon atoms.

Preferably, R ₈ represents an alkyl group with 1 to 5 carbon atoms or an alkoxy group with 1 to 5 carbon atoms.

In the aforementioned liquid crystal composition, relative to the total amount of the liquid crystal composition, the weight percentage of the liquid crystal compound represented by the aforementioned formula I is preferably, for example, 1-40%.

In the aforementioned liquid crystal composition, relative to the total amount of the liquid crystal composition, the weight percentage of the liquid crystal compound represented by the aforementioned formula II is, for example, 1-90%.

In the aforementioned liquid crystal composition, relative to the total amount of the liquid crystal composition, the weight percent content of the liquid crystal compound represented by the aforementioned formula III is 1 to 30%, and from obtaining suitable Δn, Δε, viscosity, VHR, rotational viscosity From the viewpoint of /elasticity constant etc., it is preferable that it is 1-25 %, and it is more preferable that it is 1-20 %.

In the above-mentioned positive dielectric anisotropy liquid crystal composition, relative to the total amount of the liquid crystal composition, the weight percentage of the liquid crystal compound represented by the above-mentioned formula IV is 1 to 30%, from which suitable Δn, Δε, From the viewpoint of viscosity, VHR, rotational viscosity/elastic constant, etc., it is preferably 1 to 25%, more preferably 1 to 20%.

In some embodiments of the foregoing positive dielectric anisotropy liquid crystal composition, each component may be contained in the following proportion. For example, the weight percentage of the compound shown in the aforementioned formula I is 1 to 40%, the weight percentage of the compound shown in the aforementioned formula II is 1 to 70%, and the weight percentage of the compound shown in the aforementioned formula III is 1-30%, and the weight percentage of the compound represented by the aforementioned formula IV is 1-30%.

V In some embodiments of the aforementioned positive dielectric anisotropy liquid crystal composition, a compound represented by the following formula V may also be included.

V

Wherein, _R represents an alkyl group with 1 to 5 carbon atoms, an alkoxy group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkenyloxy group with 3 to 5 carbon atoms. group; H on any carbon atom in R ₉ is independently optionally substituted by F, and one or two non-adjacent -CH ₂ - are optionally substituted by -O-.

R ₁₀ represents H, F, an alkyl group with 1~8 carbon atoms or an alkenyl group with 2~8 carbon atoms, in which one or two non-adjacent -CH ₂ - are optionally substituted by -O- , and optionally 4 or less of H are replaced by F.

Ring A7 and Ring A8 each independently represent a group consisting of groups selected from the group consisting of 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl-1,4- Cyclohexylene, 2-oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl, 1, 4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1,4-phenylene 2,3-bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3-bis(trifluoromethyl) Methoxy)-1,4-phenylene, 2,6-difluoro-substituted-1,4-phenylene, 2,5-difluoro-substituted-1,4-phenylene, 2-fluoro-6 -Trifluoromethyl-1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1,4-phenylene Phenyl, 2-fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5-bis(trifluoromethyl) Fluoromethyl)-1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy)-1,4 -phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene, 2-trifluoromethyl-5-trifluoromethoxy-1,4-phenylene ;

Z ₅ represents a single bond, -CF ₂ O- or -COO-;

t means 1, 2, 3 or 4;

u means 1 or 2.

V-1

V-2

V-3

V-4

V-5

V-6

V-7

V-8

V-9

V-11

V-12

V-13

V-14

V-15

V-16

V-17

V-18

V-19

V-20

V-21

V-22

V-23

V-24

V-25

V-26

V-27

V-28

V-29

V-30

V-31

V-32

V-33

V-34

V-35

V-36

V-37 Preferably, the compound represented by the aforementioned formula V is selected from the group consisting of the compounds represented by the following formulas V-1 to IV-37.

V-1

V-2

V-3

V-4

V-5

V-6

V-7

V-8

V-9

V-11

V-12

V-13

V-14

V-15

V-16

V-17

V-18

V-19

V-20

V-21

V-22

V-23

V-24

V-25

V-26

V-27

V-28

V-29

V-30

V-31

V-32

V-33

V-34

V-35

V-36

V-37

Wherein, the definitions of R ₉ and R ₁₀ are the same as above.

_Preferably , R represents H, an alkyl group with 1 to 5 carbon atoms, or an alkenyl group with 2 to 8 carbon atoms, more preferably H, an alkyl group with 1 to 3 carbon atoms, or a carbon atom Number 2~4 alkenyl.

Preferably, R ₁₀ is F, -CF ₃ , -CHF ₂ , -CH ₂ F, -OCF ₃ , -OCHF ₂ , or -OCH ₂ F. More preferably, it is F, -CF ₃ , -OCF ₃ , or -OCF ₃ .

In the aforementioned positive dielectric anisotropy liquid crystal composition, in the case of containing the compound represented by the aforementioned formula V, relative to the total amount of the liquid crystal composition, the weight percentage of the liquid crystal compound represented by the aforementioned formula V It may be, for example, 1 to 30%. From the viewpoint of obtaining suitable Δn, Δε, viscosity, VHR, rotational viscosity/elastic constant, etc., it is preferably 1 to 25%, more preferably 1 to 20%.

In some embodiments of the aforementioned liquid crystal composition, for example, each component may be contained in the following ratio: the weight percentage of the compound represented by the aforementioned formula I is 1 to 40%, and the weight percentage of the compound represented by the aforementioned formula II The weight percentage is 1-70%, the weight percentage of the compound shown in the aforementioned formula III is 1-30%, the weight percentage of the compound shown in the aforementioned formula IV is 1-30%, and the weight percentage of the compound shown in the aforementioned formula V is 1-30%. The weight percent content of the compounds shown is 1-30%.

VI In some embodiments of the above-mentioned positive dielectric anisotropy liquid crystal composition, from the aspects of obtaining viscosity reduction to increase response speed, reducing defects such as image sticking, preferably, it also contains one or more of the following formula VI compound of:

VI

In formula VI, R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or a carbon atom Alkenyloxy with a number of 2 to 7; and, H on any carbon atom in R ₁₁ and R ₁₂ is independently optionally substituted by F, wherein one or two non-adjacent -CH ₂ - is optionally replaced by - O-replaced;

Ring D means 1,4-cyclohexylene, cyclohexene-1,4-diyl, 2-oxane-1,4-diyl, 2,6-dioxane-1 ,4-diyl, 1,4-phenylene, 2-fluoro-1,4-diphenylene, 2-methyl-1,4-diphenylene, or, 2,3-difluoro- 1,4-phenylene, wherein any H atom is optionally substituted by -F or _-CH3 ;

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

、

或者

； Ring E represents the group consisting of groups selected from the following:

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

or

;

Z ₆ represents a single bond, -CH ₂ O-, -CF ₂ O-, -COO-, or -CH ₂ CH ₂ -;

w, x, y, and z represent 0, 1, 2, or 3 each independently.

Examples of the alkyl group having 1 to 8 carbon atoms represented by the aforementioned R ₁₁ and R ₁₂ include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl , N-octyl, etc.

Examples of the "alkoxy group having 1 to 8 carbon atoms" represented by R ₁₁ and R ₁₂ include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, base, heptyloxy, octyloxy, etc.

Examples of the "alkenyl group having 2 to 7 carbon atoms" represented by R ₁₁ and R ₁₂ include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-but Alkenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl , 4-heptenyl, 5-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 4-heptenyl, 5-heptenyl, 6-heptenyl, etc.

Examples of the "alkenyloxy group having 2 to 7 carbon atoms" represented by R ₁₁ and R ₁₂ include vinyloxy, allyloxy, 3-butenyloxy, 3- Pentenyloxy, 4-pentenyloxy, 3-hexenyloxy, 4-hexenyloxy, 5-hexenyloxy, 3-heptenyloxy, 4-heptene yloxy, 5-heptenyloxy, 6-heptenyloxy and the like.

The aforementioned R ₁₁ and R ₁₂ represent an alkyl group with 1 to 8 carbon atoms, an alkoxy group with 1 to 8 carbon atoms, an alkenyl group with 2 to 7 carbon atoms, or an alkyl group with 2 carbon atoms In the alkenyloxy group of ~7, H in these groups is independently optionally substituted by F, and one or two non-adjacent -CH ₂ - are optionally substituted by -O-.

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

VI-

17

VI-

18

VI-

19

VI-

20

VI-

21

VI-

22

VI-

23

VI-

24

VI-

25

VI-

26

VI-

27

VI-

28

VI-

29

VI-

30

VI-

31

VI-

32

VI-

33

VI-

34

VI-

35

VI-

36

VI-

37

VI-

38

VI-

39

VI-

40

VI-

41

VI-

42

VI-

43

VI-

44

VI-

45

VI-

46

VI-

47

VI-

48

VI-

49

VI-

50

VI-

51

VI-

52

VI-

53

VI-

54

VI-

55

VI-

56

VI-

57

VI-

58

VI-

59

VI-

60

VI-

61

VI-

62

VI-

63

VI-

64

VI-

65

VI-

66

VI-

67

VI-

68

VI-

69

VI-

70

VI-

71

VI-

72

VI-

73

VI-

74

VI-

75

VI-

76

VI-

77

VI-

78 The compound represented by the aforementioned formula VI is preferably selected from the group consisting of compounds represented by the following formula VI-1 to formula VI-78.

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

VI-

17

VI-

18

VI-

19

VI-

20

VI-

twenty one

VI-

twenty two

VI-

twenty three

VI-

twenty four

VI-

25

VI-

26

VI-

27

VI-

28

VI-

29

VI-

30

VI-

31

VI-

32

VI-

33

VI-

34

VI-

35

VI-

36

VI-

37

VI-

38

VI-

39

VI-

40

VI-

41

VI-

42

VI-

43

VI-

44

VI-

45

VI-

46

VI-

47

VI-

48

VI-

49

VI-

50

VI-

51

VI-

52

VI-

53

VI-

54

VI-

55

VI-

56

VI-

57

VI-

58

VI-

59

VI-

60

VI-

61

VI-

62

VI-

63

VI-

64

VI-

65

VI-

66

VI-

67

VI-

68

VI-

69

VI-

70

VI-

71

VI-

72

VI-

73

VI-

74

VI-

75

VI-

76

VI-

77

VI-

78

When the liquid crystal composition of the present invention contains the compound represented by the aforementioned formula VI, the weight percentage of the compound represented by the aforementioned formula VI in the liquid crystal composition can be, for example, 1-20%, preferably 1-10%.

In the liquid crystal composition of the present invention, in addition to the liquid crystal compounds listed above, those skilled in the art can also add other liquid crystal compounds and non-liquid crystal compounds on the basis of not destroying the desired properties of the liquid crystal composition.

In the positive dielectric anisotropy liquid crystal composition of the present invention, optionally, various functional additives can also be added, and these additives can be listed such as UV stabilizers, antioxidants, chiral dopants, polymerization initiators, One or more of them may be included.

、

、

、

The aforementioned antioxidants can be listed, for example:

,

,

,

m represents an integer from 1 to 10;

，其中，R ₀表示碳原子數為1~10的烷基； Examples of chiral dopants include,

, wherein, R ₀ represents an alkyl group with 1 to 10 carbon atoms;

，其中，Z ₀表示碳數為1～20的亞烷基，所述亞烷基中任意的一個或多個氫任選被鹵素取代，任意的一個或多個-CH ₂-任選被-O-取代。 As light stabilizers, for example,

, wherein, Z ₀ represents an alkylene group with a carbon number of 1 to 20, any one or more hydrogens in the alkylene group are optionally replaced by halogen, and any one or more -CH ₂ - are optionally replaced by - O-substitution.

，或者

，其中，R ₀₁表示碳原子數為1~10的烷基。 Examples of ultraviolet absorbers include, for example,

,or

, wherein, R ₀₁ represents an alkyl group with 1 to 10 carbon atoms.

The addition amount of the aforementioned additives may be, for example, 0.01% to 1.5% of the total mass of the liquid crystal composition.

[Liquid crystal display device]

The second aspect of the present invention provides a liquid crystal display device using the aforementioned liquid crystal composition of the present invention. The liquid crystal display device of the present invention is not particularly limited as long as it contains the aforementioned liquid crystal composition. Those skilled in the art can select suitable other compositions and structures of the liquid crystal display device according to the required performance.

The driving mode of the liquid crystal display device of the present invention is preferably, for example, IPS mode or FFS mode.

Example

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

In the present invention, the preparation method is a conventional method unless otherwise specified, and the raw materials used can be obtained from open commercial channels unless otherwise specified, and the percentages refer to mass percentages, the temperature is Celsius (°C), and the liquid crystal compound is also liquid crystal monomer.

C

P

G

U

GI

Y

A

D

(C1)

(C2)

(C3)

(C4)

B

B[F,OT]

B[OT,F]

B[OT,OT]

B(S)

B(S)[F,OT]

B(S)[OT,F]

B(S)[OT,OT] 表（二）：端基與鏈接基團的對應代碼 端基與鏈接基團 對應代碼 C _nH _2n+1- n -OC _nH _2n+1 On -OCF ₃ OT -CF ₃ T -CF ₂O- Q -CH ₂O- O -F F -CN N -CH ₂CH ₂- E -CH=CH- V -C≡C- T -COO- Z -CH=CH-C _nH _2n+1 Vn

C(5)

C(4)

C(3)1 The structures of the liquid crystal monomers used in the examples of the present application are represented by the following codes, and the code representation methods of the liquid crystal ring structure, end groups, and linking groups are shown in Table (1) and Table (2) below. Table (1): Corresponding codes of the ring structure ring structure corresponding code

C

P

G

u

GI

Y

A

D.

(C1)

(C2)

(C3)

(C4)

B

B[F,OT]

B[OT,F]

B[OT,OT]

B(S)

B(S)[F,OT]

B(S)[OT,F]

B(S)[OT,OT] Table (2): Corresponding codes of terminal groups and linking groups End group and linking group corresponding code C _n H _2n+1 - no -OC _n H _2n+1 On -OCF ₃ OT -CF ₃ T -CF ₂ O- Q -CH ₂ O- o -F f -CN N -CH ₂ CH ₂ - E. -CH=CH- V -C≡C- T -COO- Z -CH=CH-C _n H _2n+1 vn

C(5)

C(4)

C(3)1

CVEPGUV-F

CPP-1V-2 Example:

CVEPGUV-F

CPP-1V-2

[Liquid crystal compound]

反應路線圖2：CVEPGU-V-F的製備線路圖 Embodiment 1: Preparation of CVEPGU-VF

Reaction scheme 2: The preparation scheme of CVEPGU-VF

CVEPGU-V-F was prepared according to the preparation route shown in Figure 2 of the above reaction scheme.

The specific instructions are as follows:

所示化合物的製備 A-1 structure:

Preparation of the indicated compounds

Under nitrogen protection, 387g of 3,4,5-trifluorophenylboronic acid, 2500ml of tetrahydrofuran, 450g of sodium carbonate, 950ml of deionized water and 12g of tetrakis(triphenylphosphine)palladium were added to the three-necked flask. Under stirring, heat to weak reflux, add dropwise the solution prepared by 600g 2-fluoro-4-bromoiodobenzene and 1100ml tetrahydrofuran, add dropwise for about 3 hours, and continue to reflux for 16 hours after the dropwise addition.

Cool down to 40°C, add toluene and water to the reaction solution, and separate the water layer after stirring. After extraction with toluene, the mixed solution of toluene and ethanol crystallizes to obtain 366 g of the compound represented by formula A-1 in the form of white powder.

所示化合物的製備 A-2 structure:

Preparation of the indicated compounds

Into a clean three-neck bottle, first replace the inner air with nitrogen for 10 minutes. Subsequently, 306 g of the compound represented by formula A-1 and 1200 ml of anhydrous tetrahydrofuran were sequentially added. Turn on the stirring, pass liquid nitrogen to lower the temperature, when the temperature drops to -78°C, start to add 430ml 2.5M butyllithium n-hexane solution dropwise, and control the temperature at -70～-80°C during the whole process. After dripping, keep warm for 1 hour. After the heat preservation is completed, add the pre-prepared THF solution of triisopropyl borate (280g triisopropyl borate dissolved in 300ml tetrahydrofuran) dropwise. During the dropwise addition, the internal temperature is controlled at -70～-80°C, about 1 hour. After finishing, continue to keep warm for 30 minutes, then naturally heat up for about 2 to 3 hours.

When the temperature rises to about -20°C, add the reaction solution to dilute hydrochloric acid for hydrolysis, stir the hydrolyzate for 0.5 hours, separate layers, extract the lower aqueous phase with ethyl acetate twice, combine the organic phases, and neutralize with sodium bicarbonate To PH value 6~7. Rotary evaporation and solvent removal gave 256g of white powder, namely the compound shown in formula A-2, which was directly used in the next step without purification.

所示化合物的製備 Formula A-3 structure:

Preparation of the indicated compounds

Under nitrogen protection, add 700g of deionized water into the reaction bottle, start stirring, add 190g of anhydrous sodium carbonate into the three-necked bottle, stir for about 10 minutes to dissolve. Then add 1000ml of toluene, 450ml of ethanol, 232g of p-bromophenylpropionaldehyde ethylene acetal, and 243g of the intermediate I-2 prepared in the previous step. After the addition was completed, the air in the kettle was replaced with nitrogen for 1 hour, and 0.5 g of catalyst bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride was added. After adding the catalyst, stir and raise the temperature to 75°C to 80°C, and keep the temperature for 2.5 hours until the reaction ends.

The temperature of the reaction solution was lowered to 20-30°C, then the stirring was stopped, and the layers were separated, and the organic layer was set aside. The aqueous phase was extracted twice with toluene, the organic phases were combined, washed with water until neutral, vacuum rotary evaporated to dryness, and recrystallized from ethanol to obtain 325 g of intermediate A-3.

所示化合物的製備 A-4 structure:

Preparation of the indicated compounds

Under the protection of nitrogen, add 440ml of toluene, 320g of the intermediate A-3 prepared in the previous step, and 1200ml of formic acid into the three-necked flask. After stirring at room temperature to completely dissolve, heat up to 60-65°C and keep stirring for 5 hours until the intermediate A-3 remains. Amount ≤ 0.02%.

Stop stirring, let stand to separate layers, separate the lower formic acid phase, extract once with 100ml toluene, wash the combined toluene phase once with water, once with saturated sodium bicarbonate, and finally wash with saturated brine until neutral, add anhydrous sodium sulfate to the organic phase, stir and dry, Suction filtration, vacuum rotary evaporation of the filtrate, to obtain 250g of intermediate A-4, directly proceed to the next step reaction without purification.

所示化合物的製備 A-5 structure:

Preparation of the indicated compounds

Under the protection of nitrogen, add 700ml of toluene and 96g of 4-vinylcyclohexyl iodide methane phosphine salt into the reaction flask, stir at 20-30°C for about 30 minutes, and cool down to -5-0°C, mix 25g of potassium tert-butoxide with 150ml The solution prepared by THF was added dropwise into the reaction bottle, and the temperature was controlled at -5~0°C during the dropwise addition. After dripping, continue to keep warm for 2 hours. Prepare a solution of 150ml of toluene and 55g of intermediate I-4, add it dropwise into the reaction flask at a controlled temperature of -5~0°C, and keep it warm for 3 hours after the addition is completed.

Quenching with tap water, static layering, combined organic phases and washing with water until neutral, stirring and drying with anhydrous sodium sulfate for 0.5-1 hour, suction filtration with anhydrous sodium sulfate, and desolvation of the filtrate under reduced pressure. The precipitated solid was boiled with petroleum ether, filtered with suction, and the filtrate was kept for later use. The resulting solid was suction filtered, and the above operation was repeated twice with petroleum ether. The filtrates were combined and passed through a silica gel column. After passing through the column solution for desolvation under reduced pressure, 68 g of crude product containing cis- and trans-form A-5 were obtained, which was directly used for the next step configuration conversion.

所示化合物的製備 Single crystal A-6 (CVEPGU-VF) structure:

Preparation of the indicated compounds

Under the protection of nitrogen, add 150ml of toluene, 50g of the intermediate I-5 obtained in the previous step, 12g of sodium benzenesulfinate, 7ml of 36% concentrated hydrochloric acid (wt%) into the reaction bottle, stir at room temperature and completely dissolve, then heat up to 60°C , 60 ~ 65 ℃ insulation and stirring for 8 hours.

After the reaction, add 20ml of deionized water into the reaction bottle, stir for 30 minutes, stop stirring, let stand to separate layers, separate the lower layer of water phase, and extract the water phase with toluene twice. The combined organic phases were washed three times with water until neutral. The organic phase was desolvated under reduced pressure to obtain 48 g of crude product. The crude product was crystallized three times from ethanol and n-hexane to obtain a white solid. The recrystallized material was dried, passed through a silica gel (70-200 mesh) column, and washed with n-heptane to obtain 30 g of trans-CVEPGU-V-F, the mass spectrum of which is shown in Figure 1.

MS(EI, m/z): 149, 315, 464

反應路線圖3：CVEPUQU-V-F的製備路線圖 Embodiment 2: Preparation of CVEPUQU-VF

Reaction scheme 3: Preparation scheme of CVEPUQU-VF

CVEPUQU-V-F was prepared following the reaction scheme 3 shown above.

所示化合物的製備 B-2 structure:

Preparation of the indicated compounds

Into the three-neck flask, replace the inner air with nitrogen for 10 minutes. Subsequently, 195 g of raw material B-1, 1000 ml of anhydrous tetrahydrofuran and 140 g of triisopropyl borate were successively added. Turn on the stirring, pass liquid nitrogen to cool down, when the temperature drops to -100°C, start to add 210ml 2.5 M butyllithium n-hexane solution dropwise, and control the temperature at -90～-100°C throughout the process. After dripping, keep warm for 1 hour. After continuing to keep warm for 30 minutes, heat up naturally for about 2 to 3 hours.

When the temperature rose to about -30°C, the reaction solution was added into dilute hydrochloric acid for hydrolysis, and the hydrolyzate was stirred for 1 hour and then allowed to stand for stratification. The lower aqueous phase was extracted twice with ethyl acetate, the organic phases were combined, and neutralized with sodium bicarbonate to a pH value of 6-7. Rotary evaporation and solvent removal gave 159g of white powder, i.e. Intermediate B-2, which was directly used in the next step without purification.

所示化合物的製備 B-3 structure:

Preparation of the indicated compounds

Under nitrogen protection, add 300g of deionized water into the reaction bottle, start stirring, add 76g of anhydrous sodium carbonate into the three-necked bottle, and stir for about 10 minutes to dissolve the sodium carbonate. Then add 460ml toluene, 150ml ethanol, 93g p-bromophenylpropionaldehyde ethylene acetal, 135g intermediate B-2 prepared in the previous step. After the addition, the air in the bottle was replaced with nitrogen for 30 minutes, and 0.15 g of catalyst bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride was added. After adding the catalyst, stir and raise the temperature to 75°C to 80°C, and keep the temperature for 3 hours until the reaction ends.

After the reaction solution was cooled to 20-30°C, 300ml of water was added, stirred for 15 minutes and allowed to stand for stratification, and the organic layer was set aside. The aqueous phase was extracted twice with toluene, the organic phases were combined, washed with water until neutral, vacuum rotary evaporated to dryness, and recrystallized from ethanol to obtain 140 g of intermediate B-3, which was directly used in the next step.

所示化合物的製備 B-4 structure:

Preparation of the indicated compounds

Under the protection of nitrogen, add 150ml of toluene, 120g of the intermediate B-3 prepared in the previous step, and 360ml of formic acid into the three-necked flask. After stirring at room temperature to completely dissolve, heat up to 60-65°C and keep stirring for 3 hours until the remaining amount of raw material B-3 ≤0.02%.

Stirring was stopped, the layers were allowed to stand, the organic layer was replaced, and the formic acid phase in the lower layer was extracted once with 200ml of toluene. The combined toluene phases were washed once with water, once with saturated sodium bicarbonate, and finally washed with saturated brine until neutral, the organic phase was added with anhydrous sodium sulfate, stirred and dried, filtered with suction, and the filtrate was decompressed and precipitated to obtain 105 g of intermediate B-4 without purification. Proceed directly to the next reaction.

所示化合物的製備 B-5 structure:

Preparation of the indicated compounds

Under the protection of nitrogen, add 400ml tetrahydrofuran and 73g 4-vinylcyclohexyl iodomethanephosphonium salt into the reaction flask, stir at 20~30℃ for about 30 minutes, and cool down to -15~-10℃, and mix 20g potassium tert-butoxide with The solution prepared by 125ml THF was added dropwise into the reaction bottle, and the temperature was controlled at -15～-10°C during the dropwise addition. After dropping, raise the temperature to -5～0°C and keep it warm for 2 hours. Prepare a solution of 150ml of toluene and 55g of intermediate B-4, drop it into the reaction bottle at a temperature of -15~-10°C, and keep it warm for 3 hours after the dropwise addition is completed.

Quenched with deionized water, static and separated, the organic layer was set aside, the aqueous layer was extracted with toluene, the combined organic phase was washed to neutrality, stirred and dried with anhydrous sodium sulfate for 0.5 to 1 hour, anhydrous sodium sulfate was suction filtered, and the filtrate was decompressed. dissolve. The precipitated solid was boiled with petroleum ether, filtered with suction, and the filtrate was kept for later use. The resulting solid was suction filtered, and the above operation was repeated twice with petroleum ether. The three hot filtrates were combined and passed through a silica gel column. After passing through the column solution for desolvation under reduced pressure, 62 g of the crude product containing the cis-form and trans-form compounds shown in B-5 were obtained, which was directly used for configuration conversion in the next step.

的製備 Single crystal B-6 (CVEPUQU-VF) structure:

preparation of

Under the protection of nitrogen, add toluene, 120ml and 52.5g of the intermediate B-5 obtained in the previous step, 12.5g of sodium benzenesulfinate, 7.5ml of 36% concentrated hydrochloric acid (wt%) into the reaction bottle, stir at room temperature and dissolve completely, Raise the temperature to 60°C, and keep stirring at 60-65°C for 12 hours.

After the reaction, add 40ml of deionized water into the reaction flask, stir for 30 minutes, stop stirring, let stand to separate layers, separate the lower layer of water phase, and extract the water phase with toluene twice. The combined organic phases were washed three times with water until neutral. The organic phase was desolvated under reduced pressure to obtain 47.5 g of crude product. The crude product was crystallized four times from a mixed solvent of ethanol and toluene to obtain a white solid. The recrystallized material was dried, passed through a silica gel (70-200 mesh) column, and washed with n-heptane to obtain 26.5 g of trans-CVEPUQU-V-F, whose mass spectrum is shown in Figure 2.

MS (EI, m/z): 149, 252, 401, 548.

n、

，然後採用外插法計算得到單體的T _ni、

n、

。 According to the method similar to the synthesis method of CVEPGU-VF and CVEPUQU-VF mentioned above, prepare the liquid crystal compounds recorded in the table below, and measure T _ni ,

n.

, and then use the extrapolation method to calculate T _ni ,

n.

.

The components and their mass percentages in the matrix liquid crystal are as follows: CCG-2-F 10% CCP-V-1 20% CCP-V2-1 20% CPU-3-F 20% CP-3-O2 15% CP-3-O1 15%

T _ni represents the temperature at which the liquid crystal monomer changes from a nematic phase to a clear phase, and its temperature is measured by MP-90 equipment.

表示介電各向異性，

＝

_∥-

_⊥，其中，

_∥為平行于分子軸的介電常數，ε _⊥為垂直于分子軸的介電常數，，測試條件：25℃、INSTEC:ALCT-IR1、18微米垂直盒。

represents the dielectric anisotropy,

=

_∥ -

_⊥ , where,

_∥ is the dielectric constant parallel to the molecular axis, ε _⊥ is the dielectric constant perpendicular to the molecular axis, test conditions: 25°C, INSTEC: ALCT-IR1, 18 micron vertical cell.

n=n _e-n _o，其中，n _o為尋常光的折射率，n _e為非尋常光的折射率，測試條件：589 nm、25±0.2℃。 序號 液晶化合物結構 T _ni(℃)

n

1 CVEDGUQU-V-F 205.9 0.1760 33.8 2 CVEPGU-V-T 158.5 0.2250 20.6 3 CVEPGU-3-F 173.5 0.2300 13.3 4 CVEPGU-3-OT 180.5 0.2215 17.5 5 CVEPGU-V-F 168.0 0.2285 12.9 6 CVEPGU-V-OT 174.5 0.2190 17.0 7 CVEPGUQU-3-F 232.5 0.2585 24.5 8 CVEPUQU-V-OT 110.5 0.1590 22.5 9 CVEPUQU-V-F 102.3 0.1678 18.2 10 CVEPPGU-3-F 335.2 0.3470 14.0 11 CVEPPGU-V-F 330.5 0.3450 13.5 Δn denotes the optical anisotropy,

n=n _e -n _o , where, n _o is the refractive index of ordinary light, ne is the refractive index of extraordinary light, test conditions: 589 nm, 25±0.2°C _. serial number liquid crystal compound structure T _ni (°C)

no

1 CVEDGUQU-VF 205.9 0.1760 33.8 2 CVEPGU-VT 158.5 0.2250 20.6 3 CVEPGU-3-F 173.5 0.2300 13.3 4 CVEPGU-3-OT 180.5 0.2215 17.5 5 CVEPGU-VF 168.0 0.2285 12.9 6 CVEPGU-V-OT 174.5 0.2190 17.0 7 CVEPGUQU-3-F 232.5 0.2585 24.5 8 CVEPUQU-V-OT 110.5 0.1590 22.5 9 CVEPUQU-VF 102.3 0.1678 18.2 10 CVEPPGU-3-F 335.2 0.3470 14.0 11 CVEPPGU-VF 330.5 0.3450 13.5

[Preparation of Liquid Crystal Composition]

Liquid crystal compositions of different compositions have been prepared in the following examples and comparative examples, wherein, the monomer structure, dosage (weight percentage) of the specific compound used in each example, the performance parameter test results of the liquid crystal medium obtained are shown in the table below respectively.

The unit of temperature involved in each embodiment is °C, and the specific meanings and test conditions of other symbols are as follows:

Gamma1 (mPa.s) represents the rotational viscosity coefficient of liquid crystal compounds, measuring method: instrument and equipment INSTEC: ALCT-IR1, test box thickness 18 microns vertical box, temperature 25 ° C, abbreviated as "G1";

K ₁₁ is the torsional elastic constant, K ₃₃ is the splay elastic constant, and the test conditions are: 25°C, INSTEC: ALCT-IR1, 18 micron vertical box;

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, test conditions: 25°C, INSTEC: ALCT-IR1, 18 micron vertical cell;

Δn represents optical anisotropy, Δn=n _e -n _o , where n _o is the refractive index of ordinary light, and ne _is the refractive index of extraordinary light. Test conditions: 589 nm, 25±0.2°C.

VHR represents the voltage retention rate (%) after ultraviolet light irradiation, the test conditions are 20±2°C, the voltage is ±5V, the pulse width is 1ms, and the voltage retention time is 16.7ms. The test equipment is ALCT-IV1 liquid crystal performance comprehensive tester. In the ultraviolet light polymerization of the polymerizable compound for the VHR test, ultraviolet light with a wavelength of 365 nm and an irradiation light intensity of 2.5 Mw/cm ² was used for light irradiation, and the irradiation time was 34 minutes.

In the present invention, the preparation method of the liquid crystal composition is as follows: put each liquid crystal monomer into a stainless steel beaker after weighing according to a certain proportion, place the stainless steel beaker with each liquid crystal monomer on a magnetic stirring apparatus to heat and melt, and wait for 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 obtained liquid crystal composition is filled between the two substrates of the liquid crystal display for performance testing.

The liquid crystal composition of the embodiment showing positive dielectric anisotropy is obtained by using the liquid crystal compound represented by the aforementioned formula I to formula VI in combination with other components, and the composition and content of each component in the liquid crystal composition of the embodiment are as follows shown in the table. In addition, the compound represented by the general formula I in Example 1 and Example 5 was replaced by a general-purpose positive liquid crystal compound to obtain Comparative Examples 1 and 2. Table 1 The component distribution ratio and performance parameters of the liquid crystal composition of Example 1 Compound formula liquid crystal structure parts by mass performance parameters V APUQU-3-F 5.0 Δn 0.0978 Δε +2.6 K ₁₁ (pN) 13.5 K ₃₃ (pN) 15.0 G1(mPa.s) 39.5 K ₃₃ /K ₁₁ 1.11 VHR(16.7ms) 99.98% II CC-3-V 48.0 II CC-3-V1 5.5 II CCP-V-1 15.0 II CCP-V2-1 7.0 II PGP-2-3 3.0 I CVEPGUQU-3-F 6.0 II PP-1-2V1 9.0 I CVEPPGU-3-F 1.5 Table 2 The component distribution ratio and performance parameters of the liquid crystal composition of Example 2 Compound formula liquid crystal structure parts by mass performance parameters II CC-3-V 55.0 Δn 0.1217 Δε +4.4 K ₁₁ (pN) 12.4 K ₃₃ (pN) 13.1 G1(mPa.s) 44.5 K ₃₃ /K ₁₁ 1.05 VHR(16.7ms) 99.97% II CPP-1V-2 9.5 I CVEPGU-VF 2.5 I CVEPPGU-3-F 0.5 I CVEPUQU-VF 3.5 II PGP-2-2V 12.0 V PGU-3-F 10.0 V PGUQU-4-F 7.0 Table 3 The component distribution ratio and performance parameters of the liquid crystal composition of Example 3 Compound formula liquid crystal structure parts by mass performance parameter II CC-3-V 54.0 Δn 0.1230 Δε +5.2 K ₁₁ (pN) 16.6 K ₃₃ (pN) 19.2 G1(mPa.s) 59.9 K ₃₃ /K ₁₁ 1.16 VHR(16.7ms) 99.96% II CPP-1V-2 8.0 I PP-1-2V1 10.0 I CVEDGUQU-VF 6.0 I CVEPGU-3-F 15.0 I CVEPGUQU-3-F 6.0 I CVEPPGU-3-F 1.0 Table 4 The component distribution ratio and performance parameters of the liquid crystal composition of Example 4 Compound formula liquid crystal structure parts by mass performance parameter II CC-3-V 48.0 Δn 0.1270 Δε +5.5 K ₁₁ (pN) 17.6 K ₃₃ (pN) 20.5 G1(mPa.s) 65.9 K ₃₃ /K ₁₁ 1.16 VHR(16.7ms) 99.98% II CPP-1V-1 8.5 II CPP-1V-2 11.5 I CVEPGU-VT 10.0 I CVEPGU-3-OT 10.0 I CVEPPGU-VF 2.0 I CVEPUQU-V-OT 10.0 Table 5 Component ratio and performance parameters of the liquid crystal composition of Example 5 Compound formula liquid crystal structure parts by mass performance parameters V APUQU-3-F 5.0 Δn 0.0973 Δε +2.6 K ₁₁ (pN) 13.9 K ₃₃ (pN) 15.3 G1(mPa.s) 42.0 K ₃₃ /K ₁₁ 1.10 VHR(16.7ms) 99.97% VI B(S)-2O-O5 6.5 II CC-3-V 52.0 II CC-3-V1 4.5 II CCP-V-1 13.0 II CCP-V2-1 3.0 II PGP-2-3 1.5 I CVEPGUQU-3-F 10.0 II PP-1-2V1 3.0 I CVEPPGU-3-F 1.5 Table 6 Component ratio and performance parameters of the liquid crystal composition of Example 6 Compound formula liquid crystal structure parts by mass performance parameters V APUQU-3-F 5.0 Δn 0.0970 Δε +2.7 K ₁₁ (pN) 14.1 K ₃₃ (pN) 15.5 G1(mPa.s) 41.0 K ₃₃ /K ₁₁ 1.10 VHR(16.7ms) 99.96% VI B(S)[OT,OT]-2O-O5 5.5 II CC-3-V 51.5 II CC-3-V1 5.5 II CCP-V-1 13.0 II CCP-V2-1 3.0 II PGP-2-3 2.5 I CVEPGUQU-3-F 9.5 II PP-1-2V1 3.0 I CVEPPGU-3-F 1.5 Table 7 The component distribution ratio and performance parameters of the liquid crystal composition of Example 7 Compound formula liquid crystal structure parts by mass performance parameters II CC-3-V 55.0 Δn 0.1015 Δε +2.7 K ₁₁ (pN) 12.8 K ₃₃ (pN) 15.7 G1(mPa.s) 73.4 K ₃₃ /K ₁₁ 1.23 VHR(16.7ms) 99.96% V CCP-3-OT 8.0 III CY-3-O2 6.0 VI COB(S)IC-VV 5.0 II CPP-1V-1 4.0 V PGU-3-F 7.0 I CVEPGU-VF 15.0 Table 8 The component distribution ratio and performance parameters of the liquid crystal composition of Example 8 Compound formula liquid crystal structure parts by mass performance parameter II CC-3-V 58.0 Δn 0.1018 Δε +2.7 K ₁₁ (pN) 12.5 K ₃₃ (pN) 16.0 G1(mPa.s) 70.5 K ₃₃ /K ₁₁ 1.28 VHR(16.7ms) 99.98% V CCP-3-OT 7.0 III CY-3-O2 3.0 VI COB(S)IC-VV 5.0 II CPP-1V-1 2.0 IV CV2PY-V-O2 3.0 I CVEPGU-VF 15.0 V PGU-3-F 7.0

The formulation of Comparative Example 1 is shown in Table 9 below, and its components do not contain the compound represented by formula I of the present invention. The component distribution ratio and performance parameters of the liquid crystal medium of Table 9 Comparative Example 1 Compound formula liquid crystal structure parts by mass performance parameters V APUQU-3-F 5.0 Δn 0.0978 Δε +2.6 K ₁₁ (pN) 13.6 K ₃₃ (pN) 14.9 G1(mPa.s) 41.5 K ₃₃ /K ₁₁ 1.10 VHR(16.7ms) 99.78% II CC-3-V 47.0 II CC-3-V1 5.0 II CCP-V-1 15.0 II CCP-V2-1 9.0 II PGP-2-3 3.0 V PGUQU-3-F 5.0 II PP-1-2V1 10.0 V PPGU-3-F 1.0

The formulation of Comparative Example 2 is shown in Table 10 below, and its components do not contain the compound represented by formula I of the present invention. The component distribution ratio and performance parameters of the liquid crystal medium of Table 10 Comparative Example 2 Compound formula liquid crystal structure parts by mass performance parameter V APUQU-3-F 5.0 Δn 0.0972 Δε +2.6 K ₁₁ (pN) 13.5 K ₃₃ (pN) 14.8 G1(mPa.s) 44.2 K ₃₃ /K ₁₁ 1.09 VHR(16.7ms) 99.68% VI B(S)-2O-O5 6.5 II CC-3-V 50.5 II CC-3-V1 4.5 II CCP-V-1 13.0 II CCP-V2-1 5.0 II PGP-2-3 1.5 V PGUQU-3-F 8.5 II PP-1-2V1 4.5 V PPGU-3-F 1.0

Although the present invention does not exhaust all the liquid crystal mixtures claimed for protection, those skilled in the art can foresee that, on the basis of the above-mentioned disclosed embodiments, other liquid crystal materials of the same type can be obtained in a similar way only in combination with their own professional attempts. No creative labor is required. Due to limited space, only representative implementations are listed here.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Figure 1 is the mass spectrum of trans-CVEPGU-V-F. Figure 2 is the mass spectrum of trans CVEPUQU-V-F

Claims (15)

A positive dielectric anisotropy liquid crystal compound, which is a liquid crystal compound shown in the following formula I:

I wherein, R ₁ represents H, an alkyl group with 1 to 8 carbon atoms or an alkenyl group with 2 to 8 carbon atoms, wherein optionally 4 or less Hs are replaced by F; R ₂ represents H, F, carbon An alkyl group with 1~8 atoms or an alkenyl group with 2~8 carbon atoms, in which one or two non-adjacent -CH ₂ -s are optionally substituted by -O-, and any less than 4 Hs are optionally replaced by F is substituted; m is 1 or 2; n is selected from 1, 2, 3 or 4; o is 1 or 2; Z ₁ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O -or -COO-, wherein -C ₂ H ₄ - optionally has 0~4 Hs replaced by F; Z ₂ represents a single bond, -CF ₂ O- or -COO-; ring A, ring B, and ring C are each independently represents a group consisting of groups selected from the following groups: 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl-1,4-cyclohexylene, 2 -Oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl, 1,4-phenylene , 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1,4-phenylene, 2,3 -Bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3-bis(trifluoromethoxy)- 1,4-phenylene, 2,6-difluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2-fluoro-6-trifluoromethyl -1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1,4-phenylene, 2- Fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5-bis(trifluoromethyl)- 1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy)-1,4-phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene and 2-trifluoromethyl-5-trifluoromethoxy-1,4-phenylene. The liquid crystal compound with positive dielectric anisotropy as described in Claim 1, which is selected from the group consisting of compounds represented by the following formulas I-1 to I-36:

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

I-14

I-15

I-16

I-17

I-18

I-19

I-20

I-21

I-22

I-23

I-24

I-25

I-26

I-27

I-28

I-29

I-30

I-31

I-32

I-33

I-34

I-35

I-36 Among them, R ₁ represents H, an alkyl group with 1 to 8 carbon atoms, or an alkenyl group with 2 to 8 carbon atoms, wherein at least 4 Hs are optionally substituted by F; R ₂ represents H, F , an alkyl group with 1 to 8 carbon atoms or an alkenyl group with 2 to 8 carbon atoms, in which one or two non-adjacent -CH ₂ -s are optionally substituted by -O-, and up to 4 are optional H is replaced by F. A liquid crystal composition comprising the positive dielectric anisotropy liquid crystal compound described in any one of claims 1 and 2. The liquid crystal composition according to claim 3, further comprising: at least one compound represented by formula II; at least one compound represented by formula III: and at least one compound represented by formula IV:

II

III

IV wherein, R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, Alkenyl of 2 to 5, or alkenyloxy of 3 to 5 carbon atoms; H on any carbon atom in R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ is independently optional Replaced by F, one or two non-adjacent -CH ₂ - optionally replaced by -O-; Z ₄ represents -C ₂ H ₄ -, -CH ₂ O-, -S-, -CF ₂ O- Or -COO-, wherein in -C ₂ H ₄ -, optional 0~4 Hs are replaced by F; Z ₃ represents a single bond or -CH ₂ O-; p represents 0, 1, 2 or 3; q, r, v each independently represents 0, 1 or 2; s is selected from 1, 2, 3 or 4; ring A1, ring A2, ring A3, ring A4, ring A5, ring A6 each independently represent a group selected from the following The group consisting of: 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl-1,4-cyclohexylene, 2-oxane-1,4- Diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1,4-phenylene, 2,3-bis(trifluoromethyl)-1, 4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3-bis(trifluoromethoxy)-1,4-phenylene, 2,6 -Difluoro-substituted-1,4-phenylene, 2,5-difluoro-substituted-1,4-phenylene, 2-fluoro-6-trifluoromethyl-1,4-phenylene, 2- Fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1,4-phenylene, 2-fluoro-5-trifluoromethoxy-1 ,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5-bis(trifluoromethyl)-1,4-phenylene, 2,6 -Bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy)-1,4-phenylene, 2-trifluoromethyl-6-trifluoro Methoxy-1,4-phenylene and 2-trifluoromethyl-5-trifluoromethoxy-1,4-phenylene. The liquid crystal composition as claimed in item 4, wherein the compound represented by the formula II is selected from the group consisting of the compounds represented by the following formulas II-1 to II-10:

Ⅱ-1

Ⅱ-2

Ⅱ-3

Ⅱ-4

Ⅱ-5

Ⅱ-6

II-7

Ⅱ-8

Ⅱ-9

Ⅱ-10 The definitions of R ₃ and R ₄ are the same as those in request item 4, (F) means

F or H. The liquid crystal composition as claimed in item 4 or 5, wherein the compound represented by the formula III is selected from the group consisting of the compounds represented by the following formulas III-1 to III-21:

Ⅲ-1

Ⅲ-2

III-3

III-4

III-5

III-6

III-7

III-8

III-9

III-10

III-11

III-12

III-13

III-14

III-15

III-16

III-17

III-18

III-19

III-20

III-21 The definitions of R ₅ and R ₆ are the same as those in Claim 4. The liquid crystal composition as described in any one of claims 4 to 6, wherein the compound shown in the formula IV is selected from the group consisting of the compounds shown in the following formulas IV-1 to IV-44:

IV-1

IV-2

IV-3

IV-4

IV-5

IV-6

IV-7

IV-8

IV-9

IV-10

IV-11

IV-12

IV-13

IV-14

IV-15

IV-16

IV-17

IV-18

IV-19

IV-20

IV-21

IV-22

IV-23

IV-24

IV-25

IV-26

IV-27

IV-28

IV-29

IV-30

IV-31

IV-32

IV-33

IV-34

IV-35

IV-36

IV-37

IV-38

IV-39

IV-40

IV-41

IV-42

IV-43

IV-44 R ₇ represents an alkenyl group with 2 to 5 carbon atoms, and the H on any carbon atom in R ₇ is independently optionally substituted by F, one or two non-adjacent -CH ₂ -optional Substituted by -O-; R ₈ represents an alkyl group with 1 to 5 carbon atoms, an alkoxy group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or 3 carbon atoms ~5 alkenyloxy groups; H on any carbon atom in R ₈ is independently optionally substituted by F, and one or two non-adjacent -CH ₂ - are optionally substituted by -O-. The liquid crystal composition as described in any one of claim items 4 to 7, which also contains a compound represented by the following formula V:

V _wherein , R represents an alkyl group with 1 to 5 carbon atoms, an alkoxy group with 1 to 5 carbon atoms, an alkenyl group with 2 to 5 carbon atoms, or an alkenyl group with 3 to 5 carbon atoms. Oxygen; H on any carbon atom in R ₉ is independently optionally substituted by F, and one or two non-adjacent -CH ₂ - are optionally substituted by -O-; R ₁₀ represents H, F, carbon An alkyl group with 1~8 atoms or an alkenyl group with 2~8 carbon atoms, in which one or two non-adjacent -CH ₂ -s are optionally substituted by -O-, and optionally 4 or less H Substituted by F; Ring A7 and Ring A8 each independently represent a group consisting of the following groups: 1,4-cyclohexylene, 1-methyl-1,4-cyclohexylene, 2-methyl- 1,4-cyclohexylene, 2-oxane-1,4-diyl, 2,6-dioxane-1,4-diyl, cyclohexene-1,4-diyl Base, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2-fluoro-3-trifluoromethyl-1, 4-phenylene, 2,3-bis(trifluoromethyl)-1,4-phenylene, 2-fluoro-3-trifluoromethoxy-1,4-phenylene, 2,3- Bis(trifluoromethoxy)-1,4-phenylene, 2,6-difluoro-substituted-1,4-phenylene, 2,5-difluoro-substituted-1,4-phenylene, 2 -Fluoro-6-trifluoromethyl-1,4-phenylene, 2-fluoro-5-trifluoromethyl-1,4-phenylene, 2-fluoro-6-trifluoromethoxy-1 ,4-phenylene, 2-fluoro-5-trifluoromethoxy-1,4-phenylene, 2,6-bis(trifluoromethyl)-1,4-phenylene, 2,5 -Bis(trifluoromethyl)-1,4-phenylene, 2,6-bis(trifluoromethoxy)-1,4-phenylene, 2,5-bis(trifluoromethoxy) -1,4-phenylene, 2-trifluoromethyl-6-trifluoromethoxy-1,4-phenylene and 2-trifluoromethyl-5-trifluoromethoxy-1,4 -phenylene; Z ₅ represents a single bond, -CF ₂ O- or -COO-; t represents 1, 2, 3 or 4; u represents 1 or 2. The liquid crystal composition as described in claim item 8, wherein, the compound shown in the formula V is selected from the group consisting of the compounds shown in the following formulas V-1 to V-37:

V-1

V-2

V-3

V-4

V-5

V-6

V-7

V-8

V-9

V-11

V-12

V-13

V-14

V-15

V-16

V-17

V-18

V-19

V-20

V-21

V-22

V-23

V-24

V-25

V-26

V-27

V-28

V-29

V-30

V-31

V-32

V-33

V-34

V-35

V-36

V-37 Wherein, the definitions of R ₉ and R ₁₀ are the same as those in Claim 8. The liquid crystal composition as described in any one of claim items 4 to 9, which also contains one or more compounds shown in the following formula VI:

VI In the above formula VI, R ₁₁ and R ₁₂ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, or an alkenyloxy group with 2 to 7 carbon atoms; and, each of the H on any carbon atom in R ₁₁ and R ₁₂ is independently optionally substituted by F, wherein one or two non-adjacent -CH ₂ -any Optionally replaced by -O-; Ring D represents 1,4-cyclohexylene, cyclohexene-1,4-diyl, 2-oxane-1,4-diyl, 2,6-di Oxane-1,4-diyl, 1,4-phenylene, 2-fluoro-1,4-diphenylene, 2-methyl-1,4-diphenylene, or, 2,3-Difluoro-1,4-phenylene, wherein any H atom is optionally substituted by -F or _-CH3 ; Ring E represents a group consisting of the following groups:

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

as well as

Z ₆ represents a single bond, -CH ₂ O-, -CF ₂ O-, -COO-, or -CH ₂ CH ₂ -; w, x, y, z each independently represent 0, 1, 2 or 3; The liquid crystal composition as claimed in item 10, wherein the compound represented by the formula VI is selected from the group consisting of the compounds represented by the following formula VI-1 to formula VI-78:

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

VI-

17

VI-

18

VI-

19

VI-

20

VI-

twenty one

VI-

twenty two

VI-

twenty three

VI-

twenty four

VI-

25

VI-

26

VI-

27

VI-

28

VI-

29

VI-

30

VI-

31

VI-

32

VI-

33

VI-

34

VI-

35

VI-

36

VI-

37

VI-

38

VI-

39

VI-

40

VI-

41

VI-

42

VI-

43

VI-

44

VI-

45

VI-

46

VI-

47

VI-

48

VI-

49

VI-

50

VI-

51

VI-

52

VI-

53

VI-

54

VI-

55

VI-

56

VI-

57

VI-

58

VI-

59

VI-

60

VI-

61

VI-

62

VI-

63

VI-

64

VI-

65

VI-

66

VI-

67

VI-

68

VI-

69

VI-

70

VI-

71

VI-

72

VI-

73

VI-

74

VI-

75

VI-

76

VI-

77

VI-

78. The liquid crystal composition according to any one of claims 4 to 7, wherein, in the liquid crystal composition, the weight percentage of the compound represented by formula I is 1-40%, and the compound represented by formula II The weight percentage of the compound shown is 1-70%, the weight percentage of the compound shown in the formula III is 1-30%, and the weight percentage of the compound shown in the formula IV is 1-70%. 30%. The liquid crystal composition according to claim 8 or 9, wherein, in the liquid crystal composition, the weight percentage of the compound represented by the formula I is 1-40%, and the weight percentage of the compound represented by the formula II is The weight percentage is 1-70%, the weight percentage of the compound represented by the formula III is 1-30%, the weight percentage of the compound represented by the formula IV is 1-30%, and the weight percentage of the compound represented by the formula IV is 1-30%. The weight percent content of the compound represented by formula V is 1-30%. The liquid crystal composition according to claim 10 or 11, wherein, in the liquid crystal composition, the weight percentage of the compound represented by formula I is 1-40%, and the compound represented by formula II is The weight percentage is 1-70%, the weight percentage of the compound represented by the formula III is 1-30%, the weight percentage of the compound represented by the formula IV is 1-30%, the The weight percentage of the compound represented by formula V is 1-30%, and the weight percentage of the compound represented by formula VI is 1-20%. A liquid crystal display device, comprising the liquid crystal compound described in any one of claims 1 and 2, or the liquid crystal composition described in any one of claims 3 to 14; the liquid crystal display device is an active matrix display devices, or passive matrix display devices.

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