Liquid crystal composition and applications therefor

Abstract

To provide a liquid crystal composition for developing a liquid crystal display element or a liquid crystal display that retains suitable dielectric anisotropy and optical anisotropy while having a low rotational viscosity coefficient, a large elastic constant, and good low-temperature compatibility, particularly having a fast low-temperature response speed, excellent high-temperature resistance and UV resistance, having a fast response speed and a wide display temperature range, and being able to effectively improve afterimage effects.SOLUTION: A liquid crystal composition comprises one or more compounds represented by a formula I. (R1 is a substituted / unsubstituted C1-15 alkyl group; X1 is -O-, -S-, or -CH2O-; Z is a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, -C≡C-, -CH=CH-, or -CH2CH2-).SELECTED DRAWING: None

Description

[Technical field]

[0001] This application claims priority to Taiwan Patent Application No. 112132200, filed on August 25, 2023, the disclosure of which is incorporated herein in its entirety.

[0002] The present invention relates to the field of liquid crystal display technology, specifically including liquid crystal compositions and their liquid crystal display elements or displays. [Background technology]

[0003] Liquid crystal materials are a mixture of organic rod-shaped small molecule compounds that have both the fluidity of a liquid and the anisotropy of a crystal under a certain temperature. Due to the characteristics of optical anisotropy and dielectric anisotropy, liquid crystal materials are widely used in displays such as calculators, notebook computers, automobile instruments, and televisions. With the development of display technology, flat panel display devices such as liquid crystal displays (LCDs) have become the mainstream in display devices due to their advantages such as high image quality, low power consumption, thinness, and wide range of applications, and will eventually replace cathode ray tube displays.

[0004] Depending on the display mode, LCDs are classified into types such as TN (twist nematic), STN (super twisted nematic), IPS (in-plane switching), and VA (vertical alignment).

[0005] With the rapid development of science and technology, liquid crystal is applied in the display field and is being applied more and more widely, mainly used in display terminals such as mobile phones, computers, televisions, car-mounted, outdoor displays, medical equipment and so on. As the requirements for display technology are constantly increasing, the display industry is also constantly progressing, and the application and demand for liquid crystal display elements are also increasing. Not only is there a demand for liquid crystal displays with smoother, clearer, more vivid images and higher saturation display screens, but consumers may also be sensitive to the smear (or ghost) phenomenon of liquid crystal displays, because some mobile phones have obvious smear phenomenon in winter, but in fact "smear" is an inherent attribute of displays. The biggest cause of smear is the LCD response time being too long, and the key to the image display of LCD displays is "the change in the alignment direction of liquid crystal molecules", that is, the behavior of liquid crystal molecules. Therefore, the image display quality of LCD displays can be changed as long as there are factors in the environment that affect the behavior of liquid crystal molecules. Liquid crystal materials are very sensitive to the temperature of the environment, and the lower the temperature, the slower the liquid crystal molecules flip, which means that the response time of the display is longer, and in low temperature environments the brightness decreases and the response time is significantly worse. In addition to the smear phenomenon of small and medium-sized displays such as mobile phones and tablets, the long response time of large-sized LCD displays used on desktops is also a drawback that has been pointed out.

[0006] When consumers buy LCD TVs, the biggest concern is the problem of smearing. LCD TVs are large, have a slow response, and have a smear phenomenon when watching ball sports, so VA soft screens have been recommended for a long time. The regular use of VA soft screens on LCD TVs has a clear effect, clear and high color saturation, but the stringing phenomenon sometimes appears when watching dynamic images. On the other hand, IPS hard screen LCD can solve the stringing phenomenon, and IPS hard screens have significant advantages in dynamic resolution, color reproduction accuracy, viewing angle, etc. This is because, compared with traditional soft screen LCDs, IPS hard screens have a stable arrangement structure of liquid crystal molecules and a faster response speed, so that they have a very high expressiveness in dynamic resolution, completely eliminating the blurring and water ripple diffusion phenomenon that occurs when soft screen LCD displays are subjected to external pressure and shaking, and eliminating the afterimage and stringing when playing very fast images. For this reason, IPS hard screens are adopted in industries such as spacecraft, automobiles, and subways, which are constantly in motion, and can achieve image quality without any loss. The IPS hard screen panel overcomes the smearing problem of the VA soft screen, and is clear and smooth even when viewing dynamic images. It also has excellent heat dissipation function and high surface pressure resistance.

[0007] Simply put, response time is the time it takes for a liquid crystal cell to go from emitting light to non-emitting light and back to emitting light again, that is, the time it takes for one pixel to go from black to white to black again (the principle is to apply a voltage in the liquid crystal molecules to twist and return the liquid crystal molecules). Response time is calculated in milliseconds (ms, milliseconds), and the longer the response time, the slower the response of the screen of the LCD display. Theoretically, the video playback of DVD movies with 25-30 frames per second can get a good display effect on LCD displays with a response time of 30-40 milliseconds, but 3D games with more frames per second have higher requirements for response time, 16 milliseconds, or even faster 12 milliseconds, in which case IPS hard screen LCD can embody its advantages. The shorter the response time, the less stringy and dragging feeling there is when watching a dynamic screen.

[0008] Regarding the problem of the display response speed of liquid crystal at low temperatures, from an analysis of the fundamental characteristics of liquid crystal displays, there are currently several factors that greatly affect the response speed of liquid crystal displays, as follows:

[0009] 1. The viscosity coefficient of the liquid crystal material, which is determined by the properties of the material itself.

[0010] 2. The size of the gap between the liquid crystal cell, that is, the gap between the upper and lower conductive glass substrates, which is also the thickness of the liquid crystal layer.

[0011] 3. The dielectric constant of the liquid crystal material, which is determined by the properties of the material itself.

[0012] 4. Driving voltage: the higher the driving voltage, the faster the response speed.

[0013] The viscosity coefficient of the liquid crystal material and the dielectric constant of the liquid crystal material are both directly related to the properties of the liquid crystal material itself. Increasing the driving voltage of the liquid crystal cell can improve the response speed, but it will also shorten the life of the liquid crystal. By improving the manufacturing process, the gap of the liquid crystal cell can be made smaller, so that the liquid crystal molecules can be twisted into place faster. Of course, these properties are all relative properties at room temperature, and in actual use, the liquid crystal material is composed of multiple different types of polymer organic materials, and has the common properties of liquid and solid within a certain temperature range. When the temperature changes, the kinetic energy of the liquid crystal molecules changes, and the corresponding viscosity coefficient of the liquid crystal material changes. When the temperature is high, the kinetic energy of the liquid crystal molecules is high and the viscosity coefficient is small, so that the liquid crystal can be twisted and aligned freely and quickly in the direction of the electric field under the driving of the electric field, accelerating the response speed of the display. Similarly, at low temperatures, the kinetic energy of the liquid crystal molecules decreases and the viscosity coefficient increases. When an electric field is applied to the liquid crystal molecules, the liquid crystal molecules experience a large viscous resistance, and the liquid crystal is twisted and aligned in the direction of the electric field when driven by the electric field. However, the response speed of the display slows down, and if the response speed is too slow, smearing occurs.

[0014] The liquid crystal composition not only needs to have suitable dielectric anisotropy, optical anisotropy, elastic constant, suitable nematic phase upper limit temperature, suitable nematic phase lower limit temperature, and low rotational viscosity, but also needs to satisfy the requirement of high temperature resistance so that the liquid crystal composition maintains stability even when used or placed at a relatively high temperature for a long period of time, and the liquid crystal components do not decompose to cause display defects.

[0015] Therefore, the development of a liquid crystal composition having a fast low-temperature response speed and good high-temperature resistance is a technical problem that must be solved as soon as possible. Summary of the Invention

[0016] In view of this, the present invention provides a liquid crystal composition for developing a liquid crystal display element or liquid crystal display that retains appropriate dielectric anisotropy and optical anisotropy while having low rotational viscosity, large elastic constant, good low-temperature compatibility, and in particular has a fast low-temperature response speed, good high-temperature resistance and UV resistance, a fast response speed, a wide display temperature range, and can effectively improve image retention.

[0017] In order to achieve the above object of the invention, the present invention uses the following technical solutions:

[0018] According to a first aspect of the present invention there is provided a liquid crystal composition, preferably said liquid crystal composition comprising one or more compounds of formula I: [ka] Where: R1 represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH2- in the chain alkyl group may be independently selected from -C≡C-, -CH=CH ... [ka] substituted with -O-, -S-, -CO-O- or -O-CO-; X1 represents -O-, -S- or -CH2O-; Z represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, C≡C-, -CH=CH- or -CH2CH2-.

[0019] According to a second aspect of the present invention, there is provided a liquid crystal display element or a liquid crystal display comprising the liquid crystal compound and the liquid crystal composition.

[0020] The beneficial effects of the present invention are as follows:

[0021] The present invention provides a liquid crystal composition for developing a liquid crystal display element or liquid crystal display that has suitable dielectric anisotropy and optical anisotropy while having low rotational viscosity, large elastic constant, good low-temperature compatibility, and in particular has a fast low-temperature response speed, good high-temperature resistance and UV resistance, a fast response speed, a wide display temperature range, and can effectively improve image retention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] According to a first aspect of the present invention there is provided a liquid crystal composition, preferably said liquid crystal composition comprising one or more compounds of formula I: [ka] Where: R1 represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH2- in the chain alkyl group may be independently selected from -C≡C-, -CH=CH ... [ka] substituted with -O-, -S-, -CO-O- or -O-CO-; X1 represents -O-, -S- or -CH2O-; Z represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CF2O-, C≡C-, -CH=CH- or -CH2CH2-.

[0023] In the liquid crystal composition of the present invention, the compound represented by formula I is preferably selected from the group consisting of compounds represented by the following formulae I-1 to I-15. [ka] Where: R1 represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH2- in the chain alkyl group may be independently selected from -C≡C-, -CH=CH ... [ka] It is substituted by -O-, -S-, -CO-O- or -O-CO-.

[0024] In the liquid crystal composition of the present invention, the compound represented by formula I is preferably selected from the group consisting of compounds represented by formulas I-5 and / or I-6 below. [ka] Where: R1 represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH2- in the chain alkyl group may be independently selected from -C≡C-, -CH=CH ... [ka] It is substituted by -O-, -S-, -CO-O- or -O-CO-.

[0025] In the liquid crystal composition of the present invention, the mass content of the compound represented by formula I is preferably 2 to 10%, and more preferably 3 to 8%.

[0026] In the molecular configuration of the compound represented by formula I of the present invention, the position of the double bond of cyclopentenyl is perpendicular to the molecular long axis, so that the liquid crystal molecular configuration is in an advantageous state as a whole, and the use of the compound represented by formula I in combination with the compound represented by formula II of the present invention can effectively improve the flexoelectric effect of the liquid crystal molecule and effectively reduce flicker. The compounds represented by I-5 and / or I-6 have good low-temperature compatibility and can have good fluidity at relatively low temperatures, particularly suitable for low-temperature environments of -20°C and -30°C. The liquid crystal composition containing the compounds represented by formula I-5 and / or I-6 has a fast low-temperature response speed and good UV stability, and can maintain the stability of each component after UV irradiation and the stability of the physical property parameters of the liquid crystal composition.

[0027] In the liquid crystal composition of the present invention, the compound represented by formula I-5 is preferably selected from the group consisting of compounds represented by the following formulae I-5-1 to I-5-8. [ka]

[0028] In the liquid crystal composition of the present invention, the compound represented by formula I-6 is preferably selected from the group consisting of compounds represented by the following formulae I-6-1 to I-6-8. [ka]

[0029] In the liquid crystal composition of the present invention, the mass content of the compound represented by formula I-6 is preferably 3 to 8%, and more preferably 4 to 6.5%.

[0030] The present invention provides a liquid crystal composition, which preferably further comprises one or more compounds represented by formula II and one or more compounds represented by formula III. [ka] Where: R2, R3, R4, and R5 each independently represent a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH2- in the chain alkyl group may each independently be selected from -C≡C-, -CH=CH ... [ka] It is substituted by -O-, -S-, -CO-O- or -O-CO-.

[0031] In the liquid crystal composition of the present invention, the compound represented by formula II is preferably selected from the group consisting of compounds represented by the following formulae II-1 to II-23. [ka] [ka]

[0032] In the liquid crystal composition of the present invention, preferably, the liquid crystal composition comprises at least 7% by mass of the compound represented by formula II.

[0033] In the liquid crystal composition of the present invention, the compound represented by the formula III is preferably selected from the group consisting of the compounds represented by the following formulae III-1 to III-21. [ka]

[0034] In the liquid crystal composition of the present invention, preferably, the liquid crystal composition further comprises one or more compounds represented by formula IV. [ka] Where: R6 and R7 each independently represent a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

[0035] In the liquid crystal composition of the present invention, the compound represented by the formula IV is preferably selected from the group consisting of the compounds represented by the following formulas IV-1 to IV-16. [ka]

[0036] The liquid crystal composition of the present invention preferably comprises at least three compounds represented by formula IV, and more preferably, the mass content of each of the compounds represented by formulas IV-1 to IV-16 in the liquid crystal composition is ≦3%.

[0037] The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula V. [ka] Where: R8 and R9 each independently represent a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms; [ka]

[0038] In the liquid crystal composition of the present invention, the compound represented by formula V is preferably selected from the group consisting of compounds represented by formulas V-1 and V-2 below. [ka] Where: R8 and R9 each independently represent a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

[0039] The liquid crystal composition of the present invention preferably contains at least two compounds represented by formula V-1.

[0040] The liquid crystal composition of the present invention preferably contains at least two compounds represented by formula V-2.

[0041] In the liquid crystal composition of the present invention, the compound represented by the formula V-1 is preferably selected from the group consisting of compounds represented by the following formulas V-1-1 to V-1-18. [ka]

[0042] In the liquid crystal composition of the present invention, the mass content of the compound represented by formula V-1 is preferably at least 15%, and more preferably at least 20%.

[0043] In the liquid crystal composition of the present invention, the compound represented by the formula V-2 is preferably selected from the group consisting of compounds represented by the following formulas V-2-1 to V-2-22. [ka]

[0044] In the liquid crystal composition of the present invention, the mass content of each of the compounds represented by the formulae V-2-1 to V-2-22 in the liquid crystal composition is preferably 1 to 10%, and more preferably, the mass content of each of the compounds represented by the formulae V-2-1 to V-2-22 in the liquid crystal composition is 5 to 8%.

[0045] The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula VI. [ka] Where: R10 , R 11 each independently represents a chain alkyl group having 1 to 15 carbon atoms or a chain alkenyl group having 2 to 15 carbon atoms.

[0046] In the liquid crystal composition of the present invention, the compound represented by formula VI is preferably selected from the group consisting of compounds represented by the following formulae VI-1 to VI-6. [ka]

[0047] The liquid crystal composition of the present invention preferably contains at least one compound represented by formulae VI-1 to VI-4, more preferably the mass content of the at least one compound represented by formulae VI-1 to VI-4 is 5 to 12%, and more preferably the mass content of the at least one compound represented by formulae VI-1 to VI-4 is 7 to 11%.

[0048] The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula VII. [ka] Where: R 12 , R 13 each independently represents a chain alkyl group having 1 to 15 carbon atoms or a chain alkenyl group having 2 to 15 carbon atoms, [ka]

[0049] In the liquid crystal composition of the present invention, the compound represented by formula VII is preferably selected from the group consisting of compounds represented by the following formulas VII-1 to VII-3. [ka] Where: R 12 , R 13each independently represents a chain alkyl group having 1 to 15 carbon atoms or a chain alkenyl group having 2 to 15 carbon atoms.

[0050] In the liquid crystal composition of the present invention, the compound represented by formula VII-1 is preferably selected from the group consisting of compounds represented by the following formulas VII-1-1 to VII-1-7. [ka]

[0051] In the liquid crystal composition of the present invention, the compound represented by formula VII-2 is preferably selected from the group consisting of compounds represented by the following formulas VII-2-1 to VII-2-11. [ka]

[0052] In the liquid crystal composition of the present invention, the compound represented by formula VII-3 is preferably selected from the group consisting of compounds represented by the following formulas VII-3-1 to VII-3-7. [ka]

[0053] In the liquid crystal composition of the present invention, preferably, the liquid crystal composition further comprises one or more compounds represented by formula VIII. [ka] Where: R 14 , R 15 each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms, Z represents a single bond, -CH2O- or -CH2CH2-.

[0054] In the liquid crystal composition of the present invention, the compound represented by formula VIII is preferably selected from the group consisting of compounds represented by the following formulae VIII-1 and VIII-2. [ka] Where: R 14 , R 15 each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

[0055] In the liquid crystal composition of the present invention, the compound represented by the formula VIII-1 is preferably selected from the group consisting of compounds represented by the following formulae VIII-1-1 to VIII-1-9. [ka]

[0056] In the liquid crystal composition of the present invention, the compound represented by the formula VIII-2 is preferably selected from the group consisting of the compounds represented by the following formulae VIII-2-1 to VIII-2-11. [ka]

[0057] The liquid crystal composition of the present invention preferably further comprises one or more compounds represented by formula IX. [ka] Where: R 16 , R 17 each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

[0058] In the liquid crystal composition of the present invention, the compound represented by formula IX is preferably selected from the group consisting of compounds represented by the following formulas IX-1 to IX-8. [ka]

[0059] In the liquid crystal composition of the present invention, the mass content of the compound represented by formula IX is preferably 2 to 7%, and more preferably 3 to 5%.

[0060] The liquid crystal composition of the present invention may contain other additives such as a UV stabilizer, an antioxidant, a radical scavenger, etc. Examples of the additives that can be mentioned are as follows. [ka] Here, u represents an alkylene group having 1 to 20 carbon atoms.

[0061] [Liquid crystal display element or liquid crystal display] The present invention further provides a liquid crystal display element or a liquid crystal display comprising the above liquid crystal composition.

[0062] Preferably, the liquid crystal display element is an active matrix addressed liquid crystal display element or liquid crystal display.

[0063] Preferably, the active matrix addressed liquid crystal display element is a VA-TFT, FFS-TFT or IPS-TFT liquid crystal display element.

[0064] The liquid crystal display element or liquid crystal display of the present invention comprises the liquid crystal composition of the present invention and can be used to develop a liquid crystal display element or liquid crystal display having excellent reliability and a wide operating temperature range. EXAMPLES

[0065] In order to more clearly explain the present invention, the present invention will be further described below with reference to preferred examples. As will be understood by those skilled in the art, the contents specifically described below are illustrative rather than limiting, and do not limit the scope of protection of the present invention. The examples and comparative examples in this specification are provided to more fully explain the present specification to those skilled in the art, and may be modified in various forms based on the examples and comparative examples in this specification, and the scope of protection of the present invention is not limited to the examples and comparative examples described below in detail.

[0066] In the present invention, the manufacturing methods are all ordinary methods unless otherwise specified, the raw materials used can be obtained from general distribution routes unless otherwise specified, the percentages are all mass percentages, the temperatures are in degrees Celsius (°C), the liquid crystal compounds are also called liquid crystal monomers, and the specific meanings of other symbols and the measurement conditions are as follows:

[0067] Cp indicates the clearing point (°C) of the liquid crystal, and is measured by the DSC quantitative method.

[0068] SN indicates the melting point (°C) at which the liquid crystal changes from the crystalline state to the nematic phase.

[0069] Δn indicates the optical anisotropy, Δn=n e -n o where n o is the refractive index of ordinary light, and n e is the refractive index of extraordinary light, and the measurement conditions are 25±2°C and 589 nm, and the measurement is performed using an Abbe refractometer.

[0070] Δε denotes the dielectric anisotropy,

number

number

number

[0071] γ1 indicates the rotational viscosity (mPa·s), and the measurement conditions are 25±0.5°C, a 20 micrometer vertical cell, and the measurement is performed using an INSTEC:ALCT-IR1.

[0072] K 11 is the splay elastic constant, K 33 is the bending elastic constant, K 22 is the torsional elastic constant, and the measurement conditions are 25±2°C, INSTEC:ALCT-IR1, 20 micrometer vertical cell.

[0073] VHR indicates the voltage holding ratio (%), and the measurement conditions are 60±1°C, voltage ±5V, pulse width 10ms, and voltage holding time 1.667s. The measurement equipment is a TOYO Model 6254 liquid crystal performance comprehensive tester.

[0074] τ(−20° C.) low temperature response time (ms) was measured at −20° C. using a DMS505 measuring device, and the measurement conditions were: IPS test cell with a cell thickness of 3.5 μm, and a driving voltage of 5.5 V.

[0075] The method for producing the liquid crystal composition is as follows: Each liquid crystal monomer is weighed out at a certain mixing ratio and then placed in a stainless steel beaker, and the stainless steel beaker containing each liquid crystal monomer is placed on a magnetic stirring device to heat and melt it, and after most of the liquid crystal monomer in the stainless steel beaker is melted, a magnetic rotor is added to the stainless steel beaker, the mixture is stirred uniformly, and cooled to room temperature to obtain the liquid crystal composition.

[0076] The structures of the liquid crystal monomers in the examples of the present invention are represented by codes, and the methods of expressing the ring structures, terminal groups, and linkers of the liquid crystals by codes are as shown in Tables 1 and 2.

[0077] [Table 1]

[0078] [Table 2]

[0079] Here's an example. [ka] This code is CC-Cp-V1. [ka] This code is PGP-Cpr1-2. [ka] The code is CPP-3-2V1. [ka] The code is Sb-CpeO-O2. [ka] The code is Sc-CpeO-O2. [ka] The code for this is CPY-3-O2. [ka] The code is Sc-CpO-O2. [ka] This code is CC-3-V. [ka] The code is CC-3-2V1. [ka] The code is PPY-3-O2. [ka] The code is CCY-3-O2. [ka] The code is CLY-2-O2. [ka] The code is PP-1-2V1. [ka] The code is COY-2-O2.

[0080] The comparative compounds are as follows: [ka]

[0081] Reliability of liquid crystal composition The reliability of the liquid crystal composition is evaluated by ultraviolet and high-temperature deterioration tests and VHR measurements, and the smaller the change in VHR data of the liquid crystal composition before and after the ultraviolet and high-temperature tests, the higher the ultraviolet and high-temperature resistance. Therefore, the ultraviolet and high-temperature resistance is judged by comparing the difference in VHR data before and after the tests for each Example and Comparative Example.

[0082] The liquid crystal of the example and the liquid crystal of the comparative example were each injected into a test sheet and measurements were taken. VHR indicates the voltage holding rate (%). The measurement conditions were 60±1°C, voltage ±5V, pulse width 10ms, and voltage holding time 1.667s. The measurement equipment was a TOYO Model 6254 liquid crystal performance tester.

[0083] The initial VHR value is the data obtained by measuring a test sheet that has been filled with liquid crystal and has not been subjected to any treatment.

[0084] The UV VHR is the VHR value obtained by measuring after irradiating a sheet filled with liquid crystal with 5000 mJ of UV light at room temperature.

[0085] The VHR high temperature degradation is the VHR value obtained by measuring a sheet into which liquid crystal has been injected after placing it in a high temperature oven at 100° C. for 24 hours.

[0086] Low temperature test A low-temperature storage experiment was carried out for Examples 1-8 and Comparative Examples 1-5, and the liquid crystal compositions were injected into 4.0 μm liquid crystal test cells, and the test cells were placed in a glove box at −40° C. for 960 hours to observe whether crystals precipitated.

[0087] Example 1 [Table 3]

[0088] Example 2 [Table 4]

[0089] Example 3 [Table 5]

[0090] Example 4 [Table 6]

[0091] Example 5 [Table 7]

[0092] Example 6 [Table 8]

[0093] [Table 9]

[0094] Example 7 [Table 10]

[0095] Comparative Example 1 [Table 11]

[0096] Comparative Example 2 [Table 12]

[0097] Comparative Example 3 [Table 13]

[0098] Comparative Example 4 [Table 14]

[0099] Comparative Example 5 [Table 15]

[0100] Example 8 [Table 16]

[0101] [Table 17]

[0102] A mixed crystal reliability experiment was carried out for Examples 1 to 8 and Comparative Examples 1 to 5. The liquid crystal compositions were each injected into a 20 μm liquid crystal test cell, sealed, and the initial physical parameter K value was measured. The test cell was then irradiated with UV 50 J, and the physical parameter K value was measured again. The greater the change in K value, the poorer the UV stability of the liquid crystal composition. Table 18 shows the experimental data for the elastic constant K before and after UV.

[0103] [Table 18]

[0104] As can be seen from the above experimental data, the present invention provides a liquid crystal composition for developing a liquid crystal display element or liquid crystal display that maintains suitable dielectric anisotropy and optical anisotropy while having low rotational viscosity, large elastic constant, good low temperature compatibility, and in particular has a fast low temperature response speed, good high temperature resistance and UV resistance, has a fast response speed, a wide display temperature range, and can effectively improve image retention.

[0105] Obviously, the above-mentioned embodiments of the present invention are merely examples implemented to clearly explain the present invention, and do not limit the embodiments of the present invention. Those skilled in the art may make changes or modifications to other different forms based on the above description, but it is impossible to cover all the embodiments here, and obvious changes or modifications belonging to the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A liquid crystal composition comprising one or more compounds represented by formula I. 【Chemistry 1】 Where: R １ represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH ２ Each - is independently selected from -C≡C-, -CH=CH-, in a manner in which O or S atoms are not directly bonded to each other, 【Chemistry 2】 substituted by —O—, —S—, —CO—O— or —O—CO—; X １ is -O-, -S- or -CH ２ Shows O-, Z is a single bond, -CO-O-, -O-CO-, -CH ２ O-, -OCH ２ -, -CF ２ O-, -C≡C-, -CH=CH- or -CH ２ CH ２ Indicates -.

2. 2. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula II and one or more compounds represented by formula III. 【Chemistry 3】 Where: R ２ , R ３ , R ４ , R ５ each independently represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH ２ Each - is independently selected from -C≡C-, -CH=CH-, in a manner in which O or S atoms are not directly bonded to each other, 【Chemistry 4】 It is substituted by —O—, —S—, —CO—O— or —O—CO—.

3. 2. The liquid crystal composition according to claim 1, wherein the compound represented by formula I is selected from the group consisting of compounds represented by the following formulae I-1 to I-15. 【Chemistry 5】 Where: R １ represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH ２ Each - is independently selected from -C≡C-, -CH=CH-, in a manner in which O or S atoms are not directly bonded to each other, 【Chemistry 6】 It is substituted by —O—, —S—, —CO—O— or —O—CO—.

4. The liquid crystal composition according to claim 3, wherein the compound represented by formula I is selected from the group consisting of compounds represented by the following formulas I-5 and / or I-6. 【Chemistry 7】 Where: R １ represents a chain alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the chain alkyl group may be substituted with halogen, and / or any one or more -CH ２ Each - is independently selected from -C≡C-, -CH=CH-, in a manner in which O or S atoms are not directly bonded to each other, 【Chemistry 8】 It is substituted by —O—, —S—, —CO—O— or —O—CO—.

5. 5. The liquid crystal composition according to claim 4, wherein the mass content of the compound represented by formula I is 2 to 10%.

6. 2. The liquid crystal composition of claim 1, further comprising one or more compounds represented by formula IV: 【Chemistry 9】 Where: R ６ , R ７ each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

7. 7. The liquid crystal composition according to claim 6, comprising at least three compounds represented by formula IV.

8. The liquid crystal composition according to claim 1 , further comprising one or more compounds represented by formula V: 【Chemistry 10】 Where: R ８ , R ９ each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms, 【Chemistry 11】 Shows.

9. 9. The liquid crystal composition according to claim 8, wherein the compound represented by formula V is selected from the group consisting of compounds represented by the following formulas V-1 to V-2. 【Chemistry 12】 Where: R ８ , R ９ each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

10. 10. The liquid crystal composition according to claim 9, comprising at least two compounds represented by formula V-2.

11. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula VI. 【Chemistry 13】 Where: R １０ , R １１ each independently represents a chain alkyl group having 1 to 15 carbon atoms or a chain alkenyl group having 2 to 15 carbon atoms.

12. 2. The liquid crystal composition of claim 1, further comprising one or more compounds of formula VII: 【Chemistry 14】 Where: R １２ , R １３ each independently represents a chain alkyl group having 1 to 15 carbon atoms or a chain alkenyl group having 2 to 15 carbon atoms, 【Chemistry 15】 Shows.

13. 2. The liquid crystal composition of claim 1, further comprising one or more compounds represented by formula VIII: 【Chemistry 16】 Where: R １４ , R １５ each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms, Z is a single bond, -CH ２ O- or -CH ２ -CH ２ Indicates -.

14. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula IX. 【Chemistry 17】 Where: R １６ , R １７ each independently represents a chain alkyl group having 1 to 15 carbon atoms, a chain alkenyl group having 2 to 15 carbon atoms, or a chain alkoxy group having 1 to 15 carbon atoms.

15. A liquid crystal display device comprising the liquid crystal composition according to any one of claims 1 to 14, which is an active matrix display device.

16. A liquid crystal display comprising the liquid crystal composition according to any one of claims 1 to 14, which is an active matrix display.

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