TW201825656A - Liquid crystal compound having negative dielectric anisotropy, and application therefor - Google Patents

Abstract

Provided in the present invention is a liquid crystal compound of formula(I) having negative dielectric anisotropy, the liquid crystal compound having a large absolute value of dielectric anisotropy, high optical anisotropy, high-definition bright spots, low viscosity, rapid response speed, high voltage retention, good miscibility, and good optical stability and low-temperature stability. The preparation process for the liquid crystal compound of formula (I) of the present invention has easily obtainable raw materials and a simple and easy to implement synthesis route, and is suitable for large-scale industrial production; also provided in the present invention is a liquid crystal composition containing the liquid crystal compound, the liquid crystal composition having good liquid crystal performance.

Description

   Liquid crystal compound with negative dielectric anisotropy and application thereof   

The present invention relates to a liquid crystal compound, in particular a liquid crystal compound having negative dielectric anisotropy and application thereof.

The liquid crystal display element can be used in various household appliances such as clocks and electronic calculators, measuring devices, automobile panels, word processors, computers, printers, and televisions. As the night scene display method, representative methods include PC (phase change, phase change), TN (twist nematic, twisted nematic), STN (super twisted nematic, super twisted nematic), and ECB (electrically controlled birefringence (electrically controlled birefringence), OCB (optically compensated bend), IPS (in-plane switching), VA (vertical alignment), CSH (color super homeotropic) ) And other patterns. According to the driving mode of the device, it is divided into a PM (passive matrix) type and an AM (active matrix) type. PM is divided into static and multiplex types. AM is divided into TFT (thin film transistor, thin film transistor), MIM (metal insulator metal, metal-insulating layer-metal) and other types. The types of TFTs are amorphous silicon and polycrystal silicon. The latter is divided into high temperature type and low temperature type according to the manufacturing process. Liquid crystal display elements are classified into a reflection type using natural light, a transmission type using backlight, and a semi-transmission type using two types of light sources, natural light and backlight, according to the type of light source.

Among these display modes, the IPS mode, ECB mode, VA mode, or CSH mode is different from the currently commonly used TN mode or STN mode in that the former uses a liquid crystal material having negative dielectric anisotropy. Among these display methods, especially the VA type display driven by AM, is applied to display elements that require high speed and wide viewing angle. Among them, the most anticipated is the application to liquid crystal elements such as televisions.

Regardless of the display mode, the liquid crystal materials used must have low driving voltage, high response speed, wide operating temperature range, large absolute value of negative dielectric anisotropy, high phase transition temperature, and good mutual solubility. . However, the conventional technology has a highly conjugated molecular structure and tends to have poor compatibility with other liquid crystal materials, making it difficult to use it as a constituent element of a liquid crystal composition having good electrical characteristics. Moreover, the liquid crystal compound used as a component of the liquid crystal composition which requires light stability, such as a liquid crystal display element of a thin film transistor system, requires high stability. A liquid crystal display element containing a liquid crystal composition having a large absolute value of dielectric anisotropy can reduce a base voltage value, a driving voltage, and further reduce power consumption.

For a long time, as a component of a liquid crystal composition having a negative dielectric anisotropy, which can be used for a liquid crystal display element, a large number of liquid crystal compounds in which hydrogen on a benzene ring is substituted have been studied.

Osman, MA in Molec. Crystals liq. Crystals, 82,295. Discloses negative dielectric anisotropic compounds of Ref. 1 structure:

Due to the two cyano groups on the side of the compound Ref.1, the molecule has a large negative dielectric anisotropy (literature value is -20). The document also points out that such negative dielectric anisotropic compounds with side cyano groups have the following disadvantages: 1) high viscosity; 2) poor mutual solubility with liquid crystal monomers; 3) poor light stability. Due to the above disadvantages, the application of this type of negative compounds is limited.

Reiffenrath et al., In liquid crystals, 1989, Vol. 5, No. 1,159-170, proposed the fluorine-containing negative compounds of Ref. 2 and Ref. 3 to avoid the disadvantages of dicyano negative compounds:

Although the fluorinated negative compounds such as Ref.2 and Ref.3 avoid the shortcomings of the dicyano negative compounds, they cause the negative dielectric anisotropy value to be too small (Ref.2 Dielectric Anisotropy Literature Value (-4.1, Ref.3 dielectric anisotropy literature value -6.0). Therefore, fluorine-containing compounds with large negative dielectric sides still need to be explored.

Researchers have found that the liquid crystal host composition and RM (reactive mesogen) materials disclosed in the prior art still have some drawbacks when used in PSA displays. Therefore, not every arbitrary soluble RM material is suitable for PSA displays, and it is often difficult to find a more suitable selection standard than a direct PSA test using pretilt measurement. When it is desired to polymerize by means of UV light without the addition of a photoinitiator, which may be advantageous for certain applications, the choice of liquid crystal host composition becomes smaller.

Prior art PSA displays often show an undesired "image sticking" effect where the image produced in the display by addressing a selected primitive remains visible, even when the voltage for that primitive has been turned off Or when other primitives have been addressed.

In PSA displays, image sticking effects may be observed. In such displays, ambient light or the UV component of the light emitted by the backlight causes spontaneous polymerization of unreacted RM material. In addressing primitives, this may change the tilt angle after several addressing cycles, thereby causing a change in transmittance, while in unaddressed primitives, the tilt angle and transmittance remain unaffected.

Therefore, it is hoped that when the PSA display is manufactured, the PSA display is expected to have as few image sticking effects as possible to achieve a better display effect.

Therefore, in order to meet the increasing demand for applications, the memory in the art is continuously improving the liquid crystal compounds with negative dielectric anisotropy.

Object of the invention: The object of the present invention is to provide a liquid crystal compound with negative dielectric anisotropy. The liquid crystal compound has a large absolute value of dielectric anisotropy, high optical anisotropy, high-definition bright point, low viscosity, Fast response speed, high voltage retention, good mutual solubility, and good light stability and low temperature stability make the polymerizable liquid crystal composition containing the liquid crystal compound have a large dielectric anisotropy, Low threshold voltage, fast response speed, high contrast, good mutual solubility, and good light stability and low temperature stability, and a liquid crystal device including the polymerizable liquid crystal composition exhibits very little or almost no image Residual effect.

Another object of the present invention is to provide a synthetic method for synthesizing the liquid crystal composition.

Another object of the present invention is to provide a liquid crystal composition including the liquid crystal compound and a display including the liquid crystal composition.

Technical solution: In order to accomplish the above-mentioned object of the present invention, the present invention provides a compound having negative dielectric anisotropy, the compound having a general formula I structure: Wherein, R ₁ independently represents a substituted or unsubstituted straight or branched alkyl group of 1 to 10 carbon atoms, and a substituted or unsubstituted straight or branched chain alkenyl group of 2 to 10 carbon atoms. ; R ₂ independently represents a substituted or unsubstituted straight or branched alkyl or alkoxy group of 1 to 10 carbon atoms, a substituted or unsubstituted straight or branched chain of 2 to 10 carbon atoms Alkenyl or alkenyloxy, wherein one or more -CH ₂ -may be substituted by -O-, provided that the oxygen atoms are not directly connected; the ring A represents 1,4-phenylene or 1,4 -Cyclohexylene; said m represents a positive integer of 1-12; said n represents 0 or 1; and p represents 0, 1 or 2.

In some embodiments of the present invention, R ₁ independently represents a substituted or unsubstituted linear or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted carbon group of 2 to 6 carbon atoms. Linear or branched alkenyl.

In some embodiments of the invention, m represents a positive integer from 1-6.

In some embodiments of the present invention, m represents a positive integer of 2-6.

In some embodiments of the present invention, m represents a positive integer of 3-6.

In some embodiments of the invention, when n is 1, p is 0, R ₂ independently represents a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, 2 to 6 carbons Atoms are substituted or unsubstituted straight or branched chain alkenyl groups in which one or more -CH ₂ -may be substituted by -O-, provided that the oxygen atoms are not directly connected.

In some embodiments of the present invention, the compound of the general formula I is selected from the group consisting of compounds of the following general formulae I-1 to I-4: ;as well as Wherein, R ₁ and R ₂ each independently represent a substituted or unsubstituted linear or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted linear or branched chain of 2 to 6 carbon atoms. Branched alkenyl.

In some embodiments of the present invention, the compound of the general formula I-1 is preferably selected from the group consisting of the following compounds: ;as well as Wherein, R ₁ represents a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted straight or branched chain alkenyl group of 2 to 6 carbon atoms.

In some embodiments of the present invention, the compound of the general formula I-2 is preferably selected from the group consisting of the following compounds: ;as well as Wherein, R ₁ represents a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted straight or branched chain alkenyl group of 2 to 6 carbon atoms.

In some embodiments of the present invention, the compound of the general formula I-3 is preferably selected from the group consisting of the following compounds: ;as well as Wherein, R ₁ represents a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted straight or branched chain alkenyl group of 2 to 6 carbon atoms.

In some embodiments of the present invention, the compound of the general formula I-4 is preferably selected from the group consisting of the following compounds: ;as well as Wherein, R ₁ represents a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted straight or branched chain alkenyl group of 2 to 6 carbon atoms.

Another aspect of the present invention provides a liquid crystal composition including the liquid crystal compound of the general formula I of the present invention.

In some embodiments of the present invention, the liquid crystal composition further includes one or more compounds of the general formula II and / or one or more compounds of the general formula III: Wherein, each of R ₃ , R ₄ , R ₅ and R ₆ independently represents -H, -F, a substituted or unsubstituted straight or branched chain alkyl or alkoxy group of 1 to 10 carbon atoms, Substituted or unsubstituted straight or branched chain alkenyl or alkenyloxy groups of 2 to 10 carbon atoms, in which one or more of -CH ₂ -may be substituted by -O- provided that the oxygen atoms are not directly connected ; The ring A, ring B, and ring C each independently represent 1,4-cyclohexyl, 1,4-phenylene, wherein one or more non-adjacent H of 1,4-phenylene may be Substituted by F, one or more non-adjacent -CH ₂ -in 1,4-cyclohexyl may be substituted by -O-; the Z ₁ represents a single bond, -CH ₂ O-, -OCH ₂ -,- COO-, -OCO- or -CH = CH-; said a represents 0, 1 or 2, wherein when a represents 0, ring A and ring B are not 1,4-cyclohexyl at the same time.

In some embodiments of the present invention, the liquid crystal composition further includes: one or more compounds of the general formula IV Wherein, each of R ₇ and R ₈ independently represents -H, -F, a substituted or unsubstituted linear or branched alkyl or alkoxy group of 1 to 10 carbon atoms, and 2 to 10 carbon atoms Substituted or unsubstituted straight-chain or branched alkenyl or alkenyloxy, wherein one or more -CH ₂ -may be substituted by -O- provided that the oxygen atoms are not directly connected; the ring D and Each ring E independently represents 1,4-cyclohexyl, 1,4-phenylene, wherein one or more H of 1,4-phenylene may be substituted by F, and one or more of 1,4-cyclohexyl Multiple non-adjacent -CH ₂ -may be substituted by -O-; the Z ₂ represents a single bond, -CH ₂ O-, -OCH _2- , -COO-, -OCO-, or -CH = CH-; The c represents 0 or 1.

In some embodiments of the present invention, the liquid crystal composition further includes: one or more compounds of the general formula V Wherein, R, R ₉ and R ₁₀ each independently represent -H, an alkyl or alkoxy group having 1 to 7 carbon atoms; and Y ₁ and Y ₂ each independently represent a single bond, an alkyne bond, 1- An alkylene group of 4 carbon atoms, -O-, -COO-, -OCO-, -OCOO-, -CH ₂ O-, or -OCH _2- ; each of X ₁ and X ₂ independently represents a single bond,- O-, -COO-, -OCO-, or -OCOO- ,; each of m ₁ and m ₂ independently represents an integer of 1-6; and d represents 0 or 1.

In some embodiments of the invention, R independently represents -H, -CH ₃ , -CH ₂ CH ₃ or -CH ₂ CH ₂ CH ₃ .

In some embodiments of the invention, each of R ₉ and R ₁₀ independently represents -H or -CH ₃ .

In some embodiments of the present invention, each of Y ₁ and Y ₂ independently represents a single bond, -O-, -COO-, -OCO-, -OCOO-, -CH ₂ O-, or -OCH _2- , preferably It is a single bond, -O-, -COO-, -OCO-, or -OCOO-.

In some embodiments of the present invention, each of X ₁ and X ₂ independently represents a single bond, -O-, -COO-, or -OCO-.

Another aspect of the present invention provides a display device including the liquid crystal composition of the present invention.

Another aspect of the present invention provides an application of the liquid crystal composition according to the present invention in a VA, FFS, IPS, PSVA display mode.

Beneficial effects: Compared with other negative liquid crystal compounds in the prior art, the liquid crystal compound provided by the present invention has a large absolute value of dielectric anisotropy, a higher optical anisotropy, a high-definition bright point, and a low Viscosity, fast response speed, high voltage retention, good mutual solubility, good light stability and low temperature stability, the polymerizable liquid crystal composition containing the liquid crystal compound has a large dielectric anisotropy , Low threshold voltage, fast response speed, high contrast, good mutual solubility, and good light stability and low temperature stability, while containing the polymerizable liquid crystal composition, there is little or no image retention effect In addition, in the preparation process of the liquid crystal compound of the general formula I of the present invention, raw materials are easily available, and the synthetic route is simple and feasible, which is suitable for large-scale industrial production.

The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention, and are only used to illustrate the present invention, but not to limit the present invention. Other combinations and various modifications within the concept of the present invention may be made without departing from the spirit or scope of the invention.

For ease of expression, the group structures of the liquid crystal compounds in the following examples are represented by the codes listed in Table 1:

The abbreviations of the test projects in the following examples are as follows:

Cp: clear point (nematic-isotropic phase transition temperature, ℃)

△ n: anisotropy of refractive index (589nm, 20 ° C)

△ ε: Dielectric anisotropy (1KHz, 25 ° C)

IS: The afterimage of the fixed image has reached an unacceptable level

Among them, the refractive index anisotropy was measured using an Abbe refractometer under a sodium light (589 nm) light source at 25 ° C; the dielectric test box was a TN90 type and the box thickness was 7 μm.

△ ε = ε∥-ε⊥, where ε∥ is the dielectric constant parallel to the molecular axis, and ε⊥ is the dielectric constant perpendicular to the molecular axis. Test conditions: 25 ° C, 1KHz, test box is TN90 type, box 7 μm thick.

Residual image level test: The display element is continuously driven with a voltage of 16V. At a fixed time point, observe whether the residual image of the fixed image reaches an unacceptable level. For example, at the observation time point, the residual image of the fixed image has reached an unacceptable level. The degree is recorded as IS <"the observation time point". If the residual image of the fixed image does not reach an unacceptable level at the observation time point, it is recorded as IS> "the observation time point".

The fixed observation time points are: 24 hours, 168 hours, 240 hours, 500 hours, 1000 hours.

The liquid crystal compounds of the general formula I prepared in the following examples were all tested for optical anisotropy and clearing point and the extrapolation parameters were determined according to the following methods:

The commercial liquid crystal number TS023 produced by Jiangsu Hecheng Display Technology Co., Ltd. was selected as the matrix, and the liquid crystal compound represented by the general formula I was dissolved in the host liquid crystal (host) at 10% by weight, and the optical anisotropy of the mixture was tested. , Clearing point and dielectric anisotropy, and the liquid crystal performance data of the liquid crystal compound represented by the general formula I are derived in accordance with the linear relationship according to the proportion added in the matrix.

The host liquid crystal (host) is obtained by mixing the following compounds at a ratio of 20%: 40%: 40%: ;as well as The performance test results of the parent liquid crystal are as follows:

Cp: 112 Δn: 0.08 Δε: 5.0 VHR: 98.1%.

Example 1

The synthetic route of compound I-1-10 is shown below:

1) Synthesis of compound A2

In a 1L three-necked flask, add 28.4g of compound A1, 15.8g of 2,3-phenylboronic acid, 42.4g of anhydrous sodium carbonate, 200ml of toluene, 200ml of water, 100ml of ethanol, and nitrogen, and add 0.5g of Pd (PPh ₃ ) ₄ and heat It was refluxed for 6 hours, worked up and purified by column chromatography to obtain white solid A2, 22.4 g, GC> 97%, yield: 83%.

2) Synthesis of compound A3

In a 500 ml three-necked flask, add 13.5 g of compound A2, 150 ml of anhydrous tetrahydrofuran, and reduce the temperature to -78 ° C under the protection of nitrogen. Add 21 ml of n-butyllithium (2.4 mol / L n-hexane solution) dropwise, and continue stirring at -78 ° C. After 1 h, a mixture of 12.6 g of triisobutyl borate and 100 ml of anhydrous tetrahydrofuran was added dropwise, stirring was continued for 1 h, and the temperature was naturally raised to -40 ° C. The reaction solution was poured into a mixture of hydrochloric acid and ice to hydrolyze, extracted, and concentrated to obtain 10.6 g light yellow solid A3, HPLC> 95%, yield: 68%.

3) Synthesis of compound A4

In a 500ml three-necked flask, 10.6g of compound A3, 100ml of dichloromethane, 50ml of dioxane, 11.5g of 30% hydrogen peroxide were added, and the mixture was stirred for 3h. After treatment, 9.5g of reddish solid A4 was obtained. GC> 97%. : 98%.

4) Synthesis of compound I-1-10

In a 500ml three-necked flask, add 2.9g of A4, 150ml of ethanol, 1.2g of sodium hydroxide, 1.3g of 4-chlorobutyl methyl ether, heat and reflux for 3h, post-treatment, and purification by column chromatography to obtain 2.4g of white solid I-1-10 , GC> 99%, yield: 81%.

According to the above synthesis method, the compounds shown in Table 2 below can be used to transform the compound C and the compound A to obtain the target compound:

The liquid crystal properties of the above target compounds are as follows:

Characterization data for Compound I-1-10:

MS: 372 (6%), 258 (47%), 87 (100%).

Characterization data for Compound I-1-6:

MS: 358 (93%), 258 (89%), 73 (100%).

Characterization data for Compound I-1-2-1:

MS: 344 (93%), 258 (100%), 59 (70%).

Characterization data for Compound I-1-2-2:

MS: 358 (94%), 258 (100%), 73 (50%).

Example 1 provides information on representative compounds among the compounds of the general formula I-1. According to the liquid crystal compounds I-1-10, I-1-6, I-1-2-1, and I in Example 1, The data of -1-2-2 shows that the liquid crystal compound of the general formula I-1 has a large absolute value of dielectric anisotropy and a relatively high optical anisotropy.

Example 2

The synthetic route of compound I-4-6 is shown below:

1) Synthesis of compound B1

In a 500ml three-necked flask, add 8.1g of compound A2, 150ml of dichloromethane, and reduce the temperature to 0 ° C under the protection of nitrogen. Dropwise add a mixture of 15g of boron tribromide and 30ml of dichloromethane. After the dropwise addition, naturally rise to room temperature Stirring was continued for 8 h, and after-treatment was performed to obtain a white solid, compound B1, 5.4 g, GC> 97%, yield: 74%.

2) Synthesis of compound B2

In a 500ml three-necked flask, 5.4g of compound B2, 150ml of ethanol, 2.7g of sodium hydroxide, 2.9g of 4-chloropropyl methyl ether were added, and the mixture was heated under reflux for 3h, after-treatment, and purified by column chromatography to obtain 5.4g of white solid B2. GC> 99%, yield: 77%.

3) Synthesis of compound B3

In a 250 ml three-necked flask, add 5.4 g of compound B2, 80 ml of anhydrous tetrahydrofuran, and reduce the temperature to -78 ° C under the protection of nitrogen. Stir for 1 h, add dropwise a mixture of 4.7 g of triisobutyl borate and 50 ml of anhydrous tetrahydrofuran, continue stirring for 1 h, and naturally raise the temperature to -40 ° C. Pour the reaction solution into a mixture of hydrochloric acid and ice to hydrolyze, extract, and concentrate to obtain 4.3 g of light yellow solid B3, HPLC> 95%, yield: 70%.

4) Synthesis of compound B4

In a 500ml three-necked flask, add 4.3g of compound B3, 100ml of dichloromethane, 50ml of dioxane, 4.1g of 30% hydrogen peroxide, stir for 3h, and post-process to obtain 3.9g of reddish solid B4, GC> 97%, yield : 98%.

5) Synthesis of compound I-4-6

In a 250ml three-necked flask, add 1.1g of B4, 80ml of ethanol, 0.4g of sodium hydroxide, 0.66g of 4-chloromethylethylcyclohexane, heat to reflux for 3h, post-process, and purify by column chromatography to obtain 1.0g of a white solid. I-4-6, GC> 99%, yield: 66%.

According to the above synthesis method, the compounds shown in Table 3 below can be used to transform the compound C and the compound A to obtain the target compound:

The liquid crystal properties of the above target compounds are as follows:

Characterization data for Compound I-4-6:

MS: 454 (37%), 330 (42%), 258 (33%), 73 (100%).

Characterization data for Compound I-4-7:

MS: MS: 468 (33%), 330 (42%), 258 (33%), 73 (100%).

Characterization data for Compound I-4-8:

MS: 482 (43%), 330 (51%), 258 (34%), 73 (100%).

Example 2 provides information on representative compounds among the compounds of the general formula I-4. The data of the liquid crystal compounds I-4-6, I-4-7, and I-4-8 in Example 2 can be seen. It is found that the liquid crystal compound of the general formula I-4 has a large absolute value of dielectric anisotropy, a high optical anisotropy, and a suitably high clearing point.

Comparative Example 1

The liquid crystal composition of Comparative Example 1 was formulated according to each compound and weight percentage listed in Table 4, which was filled between two substrates of a liquid crystal display for performance testing. The test data is shown in the following table:

99.7% of the composition of Table 4 was mixed with 0.3% of compound V-1 to form a polymerizable liquid crystal composition M1. M1 was injected into a test box and irradiated with UV light (UV lamp parameters, 365nm: 60mw / cm2, 313nm). : 0.4mw / cm2) for 3 minutes, the level of residual image was tested, and the result: IS <168 hours.

Example 3

The liquid crystal composition of Example 3 was prepared according to the compounds and weight percentages listed in Table 5. The liquid crystal composition was filled between two substrates of a liquid crystal display for performance testing. The test data is shown in the following table:

99.7% of the composition of Table 5 was mixed with 0.3% of compound V-1 to form a polymerizable liquid crystal composition M2. M2 was injected into a test box and irradiated with UV light for 3 minutes to test the level of residual image. Results: IS > 500 hours.

Example 4

The liquid crystal composition of Example 4 was formulated according to the compounds and weight percentages listed in Table 6, which was filled between the two substrates of the liquid crystal display for performance testing. The test data is shown in the following table:

99.7% of the composition of Table 6 was mixed with 0.3% of compound V-1 to form a polymerizable liquid crystal composition M3. M3 was injected into a test box and irradiated with UV light for 3 minutes to test the level of residual image. Results: IS > 500 hours.

Example 5

90% of the liquid crystal composition in Table 4 in Comparative Example 1, 9.7% of I-1-10, and 0.3% of V-1 were mixed to form a mixture M4. M4 was injected into a test box and irradiated with UV light for 3 minutes to test The level of afterimages was as a result: IS> 240 hours.

It can be seen from the data of Example 1 and Example 2 that the compound of the present invention has a large absolute value of dielectric anisotropy, a suitably high clearing point, and a suitably high optical anisotropy, and can be applied to a liquid crystal composition. .

From the data of Comparative Example 1, Example 3 and Example 4, it can be seen that when the polymerizable liquid crystal composition containing the compound of the general formula I of the present invention at a fixed time point of 500h, the afterimage of the fixed image does not reach the impossible The acceptable level of the polymerizable liquid crystal composition, which does not include the compound of the general formula I of the present invention, at a fixed time point of 168 h, that the afterimage of the fixed image has reached an unacceptable level.

It can be seen from the data of Comparative Example 1 and Example 5 that the compound of the general formula I described in the present invention is added to the polymerizable liquid crystal composition described in Comparative Example 1 to form the polymerizable liquid crystal combination of Example 5. The residual image of the fixed image has reached an unacceptable level from 168h, that is, the residual image of the fixed image has reached an unacceptable level, and the residual image of the fixed image has not reached an unacceptable level by 240h. The residual image of the fixed image is effectively improved, that is, the polymerizable liquid crystal composition containing the polymerized liquid crystal composition appears to have very few image residual effects.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as above with the preferred embodiments, they are not intended to limit the present invention. A technician, without departing from the scope of the technical solution of the present invention, can use the disclosed technical content to make a few changes or modify the equivalent embodiment for equivalent changes, but as long as it does not depart from the technical solution of the present invention, according to the technology of the present invention In essence, any simple modifications, equivalent changes, and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Industrial applicability

The liquid crystal compound according to the present invention can be applied to the field of liquid crystal.

Claims (8)

A liquid crystal compound with negative dielectric anisotropy. The compound has the general structure I: Wherein, R ₁ independently represents a substituted or unsubstituted straight or branched alkyl group of ₁ to 10 carbon atoms, and a substituted or unsubstituted straight or branched alkenyl group of 2 to 10 carbon atoms; The R ₂ independently represents a substituted or unsubstituted straight or branched alkyl or alkoxy group of 1 to 10 carbon atoms, and a substituted or unsubstituted straight or branched olefin of 2 to 10 carbon atoms Or alkenyloxy, in which one or more -CH ₂ -may be substituted by -O-, provided that the oxygen atoms are not directly connected; the ring A represents a 1,4-phenylene or a 1,4-ring Hexyl; m represents a positive integer from 1-12; n represents 0 or 1; p represents 0, 1 or 2. The negative dielectric anisotropic liquid crystal compound according to item 1 of the scope of the patent application, wherein the compound of the general formula I is selected from the group consisting of compounds of the following general formulas I-1 to I-4: ;as well as Wherein, R ₁ and R ₂ each independently represent a substituted or unsubstituted straight or branched alkyl group of 1 to 6 carbon atoms, and a substituted or unsubstituted straight or branched chain of 2 to 6 carbon atoms. Alkenyl.     A liquid crystal composition comprising a liquid crystal compound according to item 1 or 2 of the scope of patent application.     The liquid crystal composition according to item 3 of the scope of patent application, wherein the liquid crystal composition further comprises one or more compounds of the general formula II and / or one or more compounds of the general formula III: Wherein, R ₃ , R ₄ , R ₅ and R ₆ each independently represent -H, -F, a substituted or unsubstituted linear or branched alkyl or alkoxy group of 1 to 10 carbon atoms, 2 Substituted or unsubstituted straight or branched chain alkenyl or alkenyloxy groups of -10 carbon atoms, wherein one or more of -CH ₂ -may be substituted by -O-, provided that the oxygen atoms are not directly connected; The ring A, ring B, and ring C each independently represent 1,4-cyclohexyl, 1,4-phenylene, and one or more non-adjacent H of 1,4-phenylene may be F Substitution, one or more non-adjacent -CH ₂ -in 1,4-cyclohexyl may be substituted by -O-; the Z ₁ represents a single bond, -CH ₂ O-, -OCH _2- , -COO-, -OCO- or -CH = CH-; the a represents 0, 1 or 2, wherein when a represents 0, ring A and ring B are not 1,4-cyclohexyl at the same time. The liquid crystal composition according to item 3 of the scope of patent application, wherein the liquid crystal composition further comprises: Wherein, R ₇ and R ₈ each independently represent -H, -F, substituted or unsubstituted linear or branched alkyl or alkoxy group of 1-10 carbon atoms, and 2-10 carbon atoms. Substituted or unsubstituted linear or branched alkenyl or alkenyloxy, wherein one or more -CH ₂ -may be substituted by -O-, provided that the oxygen atoms are not directly connected; the ring D and ring E Each independently represents 1,4-cyclohexyl, 1,4-phenylene, wherein one or more H of 1,4-phenylene may be substituted by F, and one or more of 1,4-cyclohexyl Non-adjacent -CH ₂ -may be substituted by -O-; the Z ₂ represents a single bond, -CH ₂ O-, -OCH _2- , -COO-, -OCO-, or -CH = CH-; the c represents 0 or 1. The liquid crystal composition according to item 3 of the scope of patent application, wherein the liquid crystal composition further comprises: one or more compounds of the general formula V Wherein, R, R ₉ and R ₁₀ each independently represent -H, an alkyl or alkoxy group having 1 to 7 carbon atoms; and Y ₁ and Y ₂ each independently represent a single bond, an alkyne bond, and 1-4 Carbon atom alkylene, -O-, -COO-, -OCO-, -OCOO-, -CH ₂ O-, or -OCH _2- ; each of X ₁ and X ₂ independently represents a single bond, -O-, -COO-, -OCO-, or -OCOO- ,; m ₁ and m ₂ each independently represent an integer of 1-6; and d represents 0 or 1.     A display device comprising the liquid crystal composition according to item 3 of the scope of patent application.         A display device comprising the liquid crystal composition according to any one of claims 4 to 6 of the scope of patent application.