Liquid Crystal Composition and Its Applications

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 the priority of Taiwan Patent Application No. 112132200 filed on August 25, 2023. The disclosure content of this related application is incorporated herein by reference in its entirety.

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

Background Art

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

[0004] Liquid crystal displays are classified into types such as TN (twist nematic), STN (super twisted nematic), IPS (in-plane switching), and VA (vertical alignment) according to the type of display mode.

[0005] With the rapid development of science and technology, liquid crystals have been applied in the display field and are being applied more and more widely, mainly used in display terminals such as mobile phones, computers, televisions, in-vehicle displays, outdoor displays, and medical devices. Since 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 more and more. There is a demand not only for liquid crystal displays with smoother, clearer, more vivid images, and higher saturation, but also consumers may be sensitive to the smearing (or called ghosting) phenomenon of liquid crystal displays. This is because obvious smearing phenomena occur in some mobile phones during winter. In fact, "smearing" is an inherent attribute of the display. The biggest cause of smearing is that the response time of the LCD is too long. The core of the image display in an LCD display is "the change in the alignment direction of liquid crystal molecules", that is, the behavior of liquid crystal molecules. Therefore, the quality of the image display of an LCD display can be changed as long as there are factors in its environment that affect the behavior of liquid crystal molecules. Liquid crystal materials are very sensitive to the temperature of the environment. The lower the temperature, the slower the speed at which liquid crystal molecules reverse, which means that the response time of the display becomes longer. In a low-temperature environment, the brightness decreases and the response time deteriorates significantly. In addition to the smearing phenomenon of small and medium-sized displays such as mobile phones and tablets, it is also pointed out that the response time of large-sized liquid crystal displays used on desktops is long.

[0006] When consumers purchase a liquid crystal TV, the most concerning issue is the smearing problem. Liquid crystal TVs are large and have a slow response. When watching ball sports, there is a smearing phenomenon. Therefore, VA soft screens have been recommended since early on. By constantly using VA soft screens in liquid crystal TVs, obvious effects can be obtained, which are clear and have high saturation. However, when watching dynamic screens, the streaking phenomenon sometimes appears. On the contrary, IPS hard screen liquid crystals can solve the streaking problem. IPS hard screens have significant advantages in terms of dynamic resolution, color reproduction accuracy, viewing angle, etc. This is because compared with conventional soft screen liquid crystals, IPS hard screens have a stable arrangement structure of liquid crystal molecules, a faster response speed, and thus have very high expressiveness in dynamic resolution. They completely eliminate the blurring and water ripple diffusion phenomena that occur when soft screen liquid crystal displays are subjected to external pressure and shaking, and eliminate the afterimage and streaking when playing very fast screens. For this reason, IPS hard screens are adopted in industries such as spacecraft, automobiles, and subways that are always in a moving state, and thus high-quality images without any loss can be obtained. IPS hard screen panels overcome the smearing problem of VA soft screens, are clear and smooth even when watching dynamic screens, have a high heat dissipation function, and a high surface pressure resistance ability.

[0007] Simply put, the response time is the time required for a liquid crystal cell to change from emitting light to not emitting light and then return to the light-emitting state again, that is, the time required for one pixel to change from black to white and then back to black again (the principle is to apply a voltage within the liquid crystal molecules to twist and then restore the liquid crystal molecules). The response time is calculated in milliseconds (ms, milliseconds). The longer the response time, the slower the response of the liquid crystal display screen. When analyzed theoretically, for video playback of a DVD movie at 25 - 30 frames per second, a good display effect can be obtained on a liquid crystal display with a response time between 30 - 40 milliseconds. However, for 3D games with a higher number of frames per second, the requirements for the response time are even higher, at 16 milliseconds or even faster, 12 milliseconds. In this case, IPS hard screen liquid crystals can demonstrate their advantages. The shorter the response time, the less the feeling of trailing and dragging when viewing dynamic screens.

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

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

[0010] 2. The gap size of 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. The dielectric constant is determined by the characteristics of the material itself.

[0012] 4. The 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 characteristics of the liquid crystal material itself. By increasing the driving voltage of the liquid crystal cell, the response speed can be improved, but it also shortens the lifespan of the liquid crystal. By improving the manufacturing process, the gap of the liquid crystal cell can be reduced, thereby enabling the liquid crystal molecules to be twisted to a predetermined position faster. Naturally, all of these characteristics are relative characteristics at normal temperature. The liquid crystal material in actual use is composed of multiple different types of polymer organic materials and has characteristics common to liquids and solids 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, the viscosity coefficient is small, and the liquid crystal can be freely and rapidly twisted and aligned in the electric field direction under the drive of the electric field, accelerating the response speed of the display. Similarly, in a low-temperature situation, the kinetic energy of the liquid crystal molecules decreases, the viscosity coefficient increases, and when an electric field is applied to the liquid crystal molecules, the viscous resistance received by the liquid crystal molecules is large. The liquid crystal is twisted and aligned in the electric field direction under the drive of the electric field, but the response speed of the display becomes slow, and if the speed is too slow, a smearing phenomenon occurs.

[0014] The liquid crystal composition not only has appropriate dielectric anisotropy, optical anisotropy, elastic constants, an appropriate nematic phase upper limit temperature, an appropriate nematic phase lower limit temperature, and low rotational viscosity, but also meets the requirements of high-temperature resistance, so that the liquid crystal composition can maintain stability even when used or installed for a long time at a relatively high temperature, and the liquid crystal components will not decompose to cause display defects.

[0015] Therefore, developing a liquid crystal composition with a fast low-temperature response speed and good high-temperature resistance performance is a technical problem that needs to be solved urgently. Summary of the Invention

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

[0017] To achieve the above object of the present 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, the liquid crystal composition contains a compound represented by one or more of Formula I.

Chemical formula

Chemical formula

[0019] According to a second aspect of the present invention, there is provided a liquid crystal display element or a liquid crystal display including 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 that retains appropriate dielectric anisotropy and optical anisotropy, has low rotational viscosity, large elastic constants, good low-temperature compatibility, particularly a fast low-temperature response speed and good high-temperature and UV resistance, has a fast response speed, a wide display temperature range, and can effectively improve afterimages, for developing a liquid crystal display element or a liquid crystal display.

Embodiments for Carrying Out the Invention

[0022] According to a first aspect of the present invention, a liquid crystal composition is provided. Preferably, the liquid crystal composition contains a compound represented by one or more of Formula I.

Chemical formula

Chemical formula

[0023] The liquid crystal composition of the present invention, preferably, the compound represented by Formula I is selected from the group consisting of the compounds represented by the following Formulae I-1 to I-15.

Chemical formula

Chemical formula

[0024] The liquid crystal composition of the present invention, preferably, the compound represented by the formula I is selected from the group consisting of the compounds represented by the following formula I-5 and / or I-6.

Chemical formula

Chemical formula

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

[0026] In the molecular arrangement of the compound represented by Formula I of the present invention, since the position of the double bond of cyclopentenyl is perpendicular to the molecular long axis, the liquid crystal molecular arrangement is in an advantageous state as a whole. If the compound represented by Formula I and the compound represented by Formula II of the present invention are used in combination with each other, the flexo-electric effect of the liquid crystal molecules can be effectively improved, and the flicker can be effectively reduced. The compound represented by I-5 and / or I-6 has good low-temperature compatibility and can have good fluidity at a relatively low temperature. It is particularly suitable for a low-temperature environment of -20°C and -30°C. The liquid crystal composition containing the compound represented by Formula I-5 and / or I-6 has a fast low-temperature response speed and good UV stability, can maintain the stability of each component after UV irradiation, and can maintain the stability of the physical property parameters of the liquid crystal composition.

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

Chemical formula

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

Chemical formula

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

[0030] The liquid crystal composition provided by the present invention, preferably, the liquid crystal composition further comprises one or more compounds represented by the formula II and one or more compounds represented by the formula III.

Chemical formula

Chemical formula

[0031] The liquid crystal composition of the present invention, preferably, 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-23.

Chemical formula

Chemical formula

[0032] The liquid crystal composition of the present invention, preferably, the liquid crystal composition contains a compound represented by the formula II with a mass content of at least 7%.

[0033] The liquid crystal composition of the present invention, preferably, 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.

Chemical formula

[0034] The liquid crystal composition of the present invention, preferably, the liquid crystal composition further contains one or more compounds represented by the formula IV.

Chemical formula

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

Chemical formula

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

[0037] The liquid crystal composition of the present invention, preferably, the liquid crystal composition further contains one or more compounds represented by the formula V.

Chemical formula

Chemical formula

[0038] The liquid crystal composition of the present invention, preferably, the compound represented by the formula V is selected from the group consisting of the compounds represented by the following formulas V-1 to V-2.

Chemical formula

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

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

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

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

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

[0044] The liquid crystal composition of the present invention, preferably, the mass content of each of the compounds represented by Formulas V-2-1 to V-2-22 in the liquid crystal composition is 1 to 10%, and more preferably, the mass content of each of the compounds represented by Formulas 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, the liquid crystal composition further contains one or more compounds represented by Formula VI. [Chemical formula] Here, R10 , R 11 Each independently represents a linear alkyl group having 1 to 15 carbon atoms or a linear alkenyl group having 2 to 15 carbon atoms.

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

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

[0048] The liquid crystal composition of the present invention, preferably, the liquid crystal composition further contains one or more compounds represented by the formula VII. [Chemical formula] Here, R 12 , R 13 Each independently represents a linear alkyl group having 1 to 15 carbon atoms or a linear alkenyl group having 2 to 15 carbon atoms, [Chemical formula]

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

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

Chemical formula

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

Chemical formula

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

Chemical formula

[0053] The liquid crystal composition of the present invention, preferably, the liquid crystal composition further contains one or more compounds represented by the formula VIII.

Chemical formula

[0054] The liquid crystal composition of the present invention, preferably, the compound represented by the formula VIII is selected from the group consisting of the compounds represented by the following formulas VIII-1 to VIII-2.

Chemical formula

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

Chemical formula

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

Chemical formula

[0057] The liquid crystal composition of the present invention, preferably, the liquid crystal composition further contains one or more compounds represented by the formula IX.

Chemical formula

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

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

[0060] Other additives such as a UV stabilizer, an antioxidant, and a radical scavenger may be added to the liquid crystal composition of the present invention. The additives that can be mentioned are as follows. [Chemical formula] 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 including the above liquid crystal composition.

[0062] Preferably, the liquid crystal display element may be an active matrix addressing liquid crystal display element or a liquid crystal display.

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

[0064] The liquid crystal display element or the liquid crystal display of the present invention includes the liquid crystal composition of the present invention, has excellent reliability, and can be used for developing a liquid crystal display element or a liquid crystal display having a wide operating temperature range. [Examples]

[0065] To explain the present invention more clearly, the present invention will be further described below with reference to preferred embodiments. As will be understood by those skilled in the art, the content specifically described below is illustrative rather than limiting, and does not limit the protection scope of the present invention. The examples and comparative examples in this specification are provided to more comprehensively explain this specification to those skilled in the art. Based on the examples and comparative examples in this specification, various modifications can be made, and the protection scope of the present invention is not limited to the examples and comparative examples detailed below.

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

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

[0068] S-N represents the melting point (°C) from the crystalline state to the nematic phase of the liquid crystal.

[0069] Δn represents the optical anisotropy, and 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. The measurement conditions are 25 ± 2 °C and 589 nm, and it is measured with an Abbe refractometer.

[0070] Δε represents the dielectric anisotropy,

Number

Number

Number

[0071] γ1 represents the rotational viscosity (mPa·s). The measurement conditions are 25 ± 0.5 °C and a 20 - micrometer perpendicular cell, and it is measured using INSTEC: ALCT - IR1.

[0072] K 11 is the splay elastic constant, and K 33 is the bend elastic constant, and K 22 is the twist elastic constant. The measurement conditions are 25 ± 2 °C, INSTEC: ALCT - IR1, and a 20 - micrometer perpendicular cell.

[0073] VHR represents the voltage holding ratio (%). The measurement conditions are 60 ± 1 °C, voltage ±5 V, pulse width 10 ms, and voltage holding time 1.667 s. The measuring instrument is TOYO Model6254 liquid crystal performance comprehensive tester.

[0074] τ(-20 °C) low - temperature response time (ms) is obtained by measuring at - 20 °C using a DMS505 measuring device. The measurement conditions are an IPS test cell with a cell thickness of 3.5 μm and a driving voltage of 5.5 V.

[0075] The manufacturing method of the liquid crystal composition is as follows. After weighing each liquid crystal monomer at a certain mixing ratio and putting it into a stainless - steel beaker, the stainless - steel beaker containing each liquid crystal monomer is placed on a magnetic stirring device and heated to melt. After most of the liquid crystal monomers in the stainless - steel beaker have melted, a magnetic rotor is added to the stainless - steel beaker, the mixture is stirred uniformly, and the liquid crystal composition is obtained by cooling to room temperature.

[0076] The structure of the liquid crystal monomer in the examples of the present invention is indicated by codes. The display methods of the ring structure, end groups, and linkers of the liquid crystal by codes are as shown in Table 1 and Table 2.

[0077]

Table 1

[0078]

Table 2

[0079] For example.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chem.

Chem.

Chem.

Chem.

[0080] The comparative compounds are as follows.

Chem.

[0081] Reliability of the liquid crystal composition The reliability of the liquid crystal composition is evaluated by ultraviolet ray and high-temperature degradation tests and VHR measurement. The smaller the change in VHR data of the liquid crystal composition before and after the ultraviolet ray and high-temperature tests, the higher the ultraviolet ray resistance and high-temperature resistance. Therefore, the ultraviolet ray resistance and high-temperature resistance are determined by comparing the difference in VHR data before and after the tests of each example and comparative example.

[0082] The liquid crystals of the examples and comparative examples are respectively injected into test sheets for measurement. VHR indicates the voltage holding ratio (%), and the measurement conditions are 60 ± 1 °C, voltage ± 5 V, pulse width 10 ms, and voltage holding time 1.667 s. The measuring instrument is a TOYO Model6254 liquid crystal performance comprehensive tester.

[0083] The initial VHR value is the data obtained by measuring a test sheet into which liquid crystal is injected and no treatment is performed.

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

[0085] The VHR value of high-temperature deterioration is the value obtained by measuring after placing a sheet injected with liquid crystal in a high-temperature oven at 100 °C for 24 hours.

[0086] Low-temperature test Perform a low-temperature storage experiment on Examples 1-8 and Comparative Examples 1-5. Inject the liquid crystal composition into a liquid crystal test cell with a thickness of 4.0 μm respectively, put the test cell into a glove box at -40 °C, and observe whether crystals precipitate after placing it for 960 hours.

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

[0103]

Table 18

[0104] As can be seen from the above experimental data, the present invention retains appropriate dielectric anisotropy and optical anisotropy, and has low rotational viscosity, a large elastic constant, and good low-temperature compatibility. In particular, it has a particularly fast low-temperature response speed and good high-temperature resistance and UV resistance performance, has a fast response speed and a wide display temperature range, and can effectively improve afterimages. The present invention provides a liquid crystal composition for developing a liquid crystal display element or a liquid crystal display.

[0105] Obviously, the above embodiments of the present invention are only examples implemented for clearly explaining the present invention, and do not limit the embodiments of the present invention. For those skilled in the art, based on the above description, changes or modifications to other different forms can be made, but it is impossible to cover all embodiments here, and obvious changes or modifications belonging to the technical solution means of the present invention still belong to the protection scope of the present invention.

Claims

1. Comprising one or more compounds represented by formula I, one or more compounds represented by formula II, at least three compounds represented by formula IV, and one or more compounds represented by formula V-1 or formula V-2, The liquid crystal composition is characterized in that the mass content of the compound represented by the formula I is 2 to 10%. 【Chemical 1】 Here, R １ represents a linear alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the linear alkyl group may be substituted with a halogen, and / or any one or more of -CH ２ - each independently represents, in a manner such that O or S atoms are not directly bonded to each other, optionally -C≡C-, -CH=CH-, 【Chemical 2】 Substituted by -O-, -S-, -CO-O- or -O-CO-, X １ represents -S- or -CH ２ O-, and Z represents a single bond, R ２ 、R ３ each independently represents a linear alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the linear alkyl group may be substituted with a halogen, and / or any one or more of -CH ２ - each independently, in a manner such that O and S atoms are not directly bonded to each other, is selectively -C≡C-, -CH=CH-, 【Chemical 3】 Substituted by -O-, -S-, -CO-O- or -O-CO-, R ６ , R ７ each independently represents a linear alkyl group having 1 to 15 carbon atoms, a linear alkenyl group having 2 to 15 carbon atoms, or a linear alkoxy group having 1 to 15 carbon atoms, R ８ and R ９ each independently represents a linear alkyl group having 1 to 15 carbon atoms, a linear alkenyl group having 2 to 15 carbon atoms, or a linear alkoxy group having 1 to 15 carbon atoms.

2. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula III. 【Chemical Formula 4】 Here, R ４ 、R ５ each independently represents a linear alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the linear alkyl group may be substituted with a halogen, and / or any one or more of -CH ２ - each independently, in a manner where O and S atoms are not directly bonded to each other, is selectively -C≡C-, -CH=CH-, 【Chemical Formula 5】 Substituted by -O-, -S-, -CO-O- or -O-CO-.

3. The liquid crystal composition according to claim 1, wherein the compound represented by the formula I is selected from the group consisting of the compounds represented by the following formulae I-2 and I-3. 【Chemical Formula 6】 Here, R １ represents a linear alkyl group having 1 to 15 carbon atoms, and one or more H atoms in the linear alkyl group may be substituted with a halogen, and / or any one or more of -CH ２ - are each independently, in a manner where O or S atoms do not directly bond to each other, selectively -C≡C-, -CH=CH-, [Chemical Formula 7] Substituted by -O-, -S-, -CO-O- or -O-CO-.

4. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula VI. 【Chemical 8】 Here, R １０ and R １１ each independently represents a linear alkyl group having 1 to 15 carbon atoms or a linear alkenyl group having 2 to 15 carbon atoms.

5. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula VII. 【Chemical Formula 9】 Here, R １２ and R １３ each independently represents a linear alkyl group having 1 to 15 carbon atoms or a linear alkenyl group having 2 to 15 carbon atoms, 【Chemical Formula 10】 Indicates.

6. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula VIII. 【Chemical 11】 Here, R １４ , R １５ each independently represents a linear alkyl group having 1 to 15 carbon atoms, a linear alkenyl group having 2 to 15 carbon atoms, or a linear alkoxy group having 1 to 15 carbon atoms, Z represents a single bond, -CH ２ O- or -CH ２ -CH ２ -.

7. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula IX. 【Chemical Formula 12】 Here, R １６ , R １７ each independently represents a linear alkyl group having 1 to 15 carbon atoms, a linear alkenyl group having 2 to 15 carbon atoms, or a linear alkoxy group having 1 to 15 carbon atoms.

8. A liquid crystal display element, comprising the liquid crystal composition according to any one of claims 1 to 7 and being an active matrix display element.

9. A liquid crystal display, comprising the liquid crystal composition according to any one of claims 1 to 7 and being an active matrix display.

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