LIQUID CRYSTAL COMPOSITION CONTAINING 2-METHYL-3,4,5-TRIFLUOROBENZENE LIQUID CRYSTAL COMPOUND AND APPLICATION THEREOF

Abstract
The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound and use thereof, wherein the liquid crystal composition of the present invention comprises, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II, and may further comprise 0-30% of compounds represented by general formula III and/or 6-45% of one or more compounds represented by general formulas IV to XIII The liquid crystal composition provided by the present invention has a low rotational viscosity and a large elastic constant, is presented as having a shorter response time, and can significantly improve the display effect of a liquid crystal display when applied to TN, IPS and FFS mode displays.
Description
FIELD OF THE INVENTION

The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound and use thereof. In particular, the present invention provides a liquid crystal composition containing a liquid crystal compound in which 2-methyl-3,4,5-trifluorobenzene is linked to a difluoromethoxy bridge bond. The liquid crystal composition provided by the present invention has a fast response time, and is particularly suitable for TN/IPS/FFS-type liquid crystal display devices.


BACKGROUND OF THE INVENTION

Currently, liquid crystal has been widely applied in the information display field, and has also made some progress in optical communication applications (S. T. Wu, D. K. Yang. Reflective Liquid Crystal Displays. Wiley, 2001). In recent years, the application field of liquid crystal compounds has been significantly broadened to various types of display devices, electro-optical devices, electronic components, sensorsand the like. Nematic liquid crystal compounds have been most widely used in flat panel displays, particularly in TFT active matrix systems.


Liquid crystal display has gone through a long path of development since the discovery of liquid crystals. In 1888, Friedrich Reinitzer, an Austrian botanist, discovered the first liquid crystal material, i.e., cholesteryl benzoate. Manguin invented a rubbing orientation method for producing a single domain liquid crystal and studying optical anisotropy in 1917. E. Bose established Swarm doctrine in 1909, which was supported by experiments of L. S. Ormstein and F. Zernike et al. (1918), and was later explained as statistical fluctuations by De Gennes. In 1933, G W. Oseen and H. Zocher founded continuum theory which was modified by F. C. Frank (1958). M. Born (1916) and K. Lichtennecker (1926) found and studied liquid crystal dielectric anisotropy. In 1932, W. Kast accordingly divided the nematic phase into two categories: positive and negative. In 1927, V. Freedericksz and V. Zolinao discovered that nematic liquid crystal would be deformed and present a voltage threshold (Freederichsz change) in an electric field or magnetic field. This discovery provides a basis for the fabrication of liquid crystal displays.


In 1968, R. Williams in Radio Corporation of America (RCA) found that nematic phase liquid crystals formed stripe domains and had a light scattering phenomenon in an electric field. G H. Heilmeir then developed this into a dynamic scattering display mode, and made the first liquid crystal display (LCD) in the world. In the early 1970s, Helfrich and Schadt invented twisted-nematic (TN) principle. The combination of the TN photoelectric effect and integrated circuit made a display device (TN-LCD), which has opened up a broad application prospect for liquid crystals. Particularly since the seventies, due to the development of large-scale integrated circuits and liquid crystal materials, the application of liquid crystals has made a breakthrough development in terms of display. Super Twisted Nematic (STN) mode proposed successively by T. Scheffer et al. in 1983-1985 and an Active Matrix (AM) mode proposed by P. Brody in 1972 were re-adopted. Conventional TN-LCD technology has been developed into STN-LCD and TFT-LCD technologies. Although the number of STN scanning lines can reach 768 or greater, there are still problems, such as response speed, viewing angle and gray scale, when the temperature rises. Therefore, for a large area, high information content, color display, an active matrix display mode becomes the first choice. TFT-LCD has been widely used in direct-view televisions, large-screen projection televisions, computer terminal displays and certain military instrument displays. It is believed that TFT-LCD technology will have broader application prospects.


There are two types of “active matrix” including: 1. a metal oxide semiconductor (MOS) on a silicon wafer as a substrate; and 2. a thin film transistor (TFT) on a glass plate as a substrate.


Monocrystalline silicon as a substrate material limits the display size due to the fact that there were many problems occurring at junctions of each part of a display device or even a module assembly. Accordingly, the second type of thin film transistor is a promising active matrix type. The photoelectric effect utilized is generally the TN effect. A TFT includes a compound semiconductor, such as CdSe, or a TFT based on polycrystalline silicon or amorphous silicon.


Currently, the LCD product technologies have been well established and successfully solved technical problems regarding viewing angle, resolution, color saturation, brightness, etc., and the display performance thereof has been close to or superior to that of CRT displays. Large-size and small-to-medium-size LCDs have gradually dominated the flat panel displays in respective fields. However, due to the limitation of (the high viscosity of) the liquid crystal material itself, the response time becomes a principal factor affecting high-performance displays.


In particular, the response time of a liquid crystal is limited by the rotational viscosity y1 and the elastic constant of the liquid crystal. Therefore, reducing the rotational viscosity of a liquid crystal composition and increasing the elastic constant have a significant effect on reducing the response time of the liquid crystal display and accelerating the response speed of the liquid crystal display.


SUMMARY OF THE INVENTION

An object of the present invention is to provide a liquid crystal composition and use thereof.


In order to achieve the above object, the following technical solution is specifically adopted:


a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound, comprising, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II,




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wherein R1, R2 and R3 each independently represent a C1-C12 linear alkyl group or a C1-C12 linear alkyl group having one or more non-adjacent CH2 substituted with O, S or CH═CH;


n each independently represents 0 or 1;


A1, A2 and A3 each independently represent the following structures:




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and


A4 and A5 each independently represent a trans-1,4-cyclohexylene group or a 1,4-phenylene group.


The liquid crystal composition provided by the present invention has a low rotational viscosity and a large elastic constant, and is presented as having a shorter response time, so that the problem of the slow response of the liquid crystal display is effectively solved.


In order to achieve a fast response time, the liquid crystal composition of the present invention comprises, in percentages by weight, 3-20% of one or more compounds represented by general formula I, and 17-63% of one or more compounds represented by general formula II; or comprises 21-45% of one or more compounds represented by general formula I, and 20-45% of one or more compounds represented by general formula II.


The liquid crystal composition of the present invention further comprises 0-30% by weight of one or more compounds represented by general formula III, and preferably further comprises 2-30% by weight of one or more compounds represented by general formula III,




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wherein R4 and R5 each independently represent a C1-C12 linear alkyl group or a C1-C12 linear alkyl group having one or more non-adjacent CH2 substituted with O, S or CH═CH; and


A6 each independently represents the following structures:




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As a preferred technical solution of the present invention, the amount of one or more compounds represented by general formula III is 2-26% by weight.


The liquid crystal composition of the present invention further comprises 6-45% by weight of one or more compounds represented by general formulas IV to IX,




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wherein R6 and R9 each independently represent a C1-C12 linear alkyl group or a C1-C12 linear alkyl group having one or more non-adjacent CH2 substituted with CH═CH; R7, R8 and R10-R12 each independently represent a C1-C12 linear alkyl group; L1-L8 each independently represent H or F; and X1—X3 and X5 each independently represent F, CF3, OCF2H or OCF3; X4 each independently represents F, CF3, OCF3, and a C1-C5 linear alkyl group or a C2-C5 linear alkenyl group; and A7 and A8 are each independently selected from the following structures:




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As a preferred technical solution of the present invention, the amount of one or more compounds represented by general formulas IV to IX is 28-37% by weight.


As an embodiment of the technical solution of the present invention, the liquid crystal composition of the present invention comprises, in percentages by weight, 6-39% of one or more compounds represented by general formula I,


22-62% of one or more compounds represented by general formula II,


2-26% of one or more compounds represented by general formula III, and


6-44% of one or more compounds represented by general formulas IV to IX.


Particularly, the compound represented by general formula I is selected from one or more of the compounds represented by formulas I-A to I-U:




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The compound represented by general formula II is selected from one or more of the following compounds:




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wherein R1 each independently represents a C1-C7 linear alkyl group; R2 each independently represents a C1-C7 linear alkyl group or linear alkoxy group or a C2-C7 linear alkenyl group; and R3 each independently represents a C1-C7 linear alkyl group.


More particularly, the compound represented by general formula I is selected from one or more of the compounds represented by formulas I-A-1 to I-U-4:




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The compound represented by general formula II is selected from one or more of the compounds represented by formulas II-A-1 to II-C-24:




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Particularly, the compound represented by general formula III is selected from one or more of the following compounds of formulas III-A to III-C:




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wherein R4 each independently represents a C2-C10 linear alkyl group or linear alkenyl group; and R5 each independently represents a C1-C8 linear alkyl group.


More preferably, the compound represented by general formula III is selected from one or more of the structures of formulas III-A-1 to III-C-30:




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In particular, the compounds of general formulas IV to IX are selected from one or more of the following structures:




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wherein R6 each independently represents a C2-C7 linear alkyl group or linear alkenyl group; R7, R8 and R10-R12 each independently represent a C2-C7 linear alkyl group; R9 and Rx each independently represent a C1-C7 linear alkyl group or a C2-C7 linear alkenyl group.


More preferably, R6 each independently represents a C2-C5 linear alkyl group or linear alkenyl group; R7, R8 and R10-R12 each independently represent a C2-C5 linear alkyl group; and R9 and Rx each independently represent a C1-C5 linear alkyl group or a C2-C5 linear alkenyl group.


The compound represented by general formula I in the liquid crystal composition provided by the present invention is a compound containing 2-methyl-3,4,5-trifluorobenzene linked to a difluoromethoxy bridge bond, wherein such compounds have a strong polarity and good mutual solubility characteristics, and the mutual solubility characteristics of such compounds can be effectively improved after the introduction of methyl in the second position, and surprisingly, as compared with methyl-free compounds, the compounds of type I provided by the present invention have a mutual solubility with an improvement of 30% or greater, and are more advantageous for improving the low temperature mutual solubility characteristics of the mixed liquid crystal; the compound represented by general formula II has a bicyclic structure and a low rotational viscosity and excellent mutual solubility characteristics, and is an essential component for a fast-response liquid crystal display; the compound represented by general formula III is a non-polar compound which has a high clearing point and a large elastic constant, and contributes to improving the elastic constant of the liquid crystal composition; and the compounds represented by general formulas IV to IX are mainly used for adjusting the clearing point and parameters, such as the optical anisotropy, of the liquid crystal composition.


The method for producing the liquid crystal composition of the present invention is not particularly limited, and the liquid crystal composition may be produced by mixing two or more compounds using a conventional method, e.g., being prepared by a method of mixing and dissolving various components at a high temperature, wherein the liquid crystal composition is dissolved in a solvent used for the compounds and mixed, and then the solvent is distilled off under a reduced pressure; or the liquid crystal composition of the present invention may be prepared according to a conventional method, e.g., being obtained by dissolving components with lower contents therein into main components with higher contents at a higher temperature, or dissolving the various components in an organic solvent, such as acetone, chloroform or methanol, and then mixing the solution, followed by the removal of the solvent.


The liquid crystal composition of the present invention has a low rotational viscosity, a large elastic constant, a good low temperature mutual solubility and a fast response speed, and can be used for fast-response liquid crystal display in a variety of display modes, and the use thereof in TN, IPS or FFS mode displays can significantly improve the display effect of liquid crystal displays.


Specific Embodiments

The following examples are intended to illustrate the invention, but not to limit the scope of the invention.


Unless otherwise indicated, the percentage in the present invention is weight percentage; the temperature unit is degrees Celsius; An represents optical anisotropy (at 25° C.); Ac represents dielectric anisotropy (at 25° C., 1000 Hz); V10 represents voltage threshold, and is the characteristic voltage (V, at 25° C.) when the relative transmittance is changed by 10%; yl represents rotational viscosity (mPa·S, at 25° C.); Cp represents the clearing point (° C.) of the liquid crystal composition; and K11, K22 and K33 represent splay, twist and bend elastic constants (pN, at 25° C.), respectively.


In each of the following examples, the group structures in the liquid crystal compound are represented by the codes shown in Table 1.









TABLE 1







Group structure codes of the liquid crystal compound









Groups
Codes
Group names







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C
1,4-cyclohexylene







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P
1,4-phenylene







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G
2-fluoro-1,4-phenylene







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U
2,6-difluoro-1,4-phenylene







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K
2-methyl-3,5-difluoro-1,4-phenylene





—O—
O
Oxygen substituent


—F
F
Fluorine substituent


—CF3
CF3
Trifluoromethyl


CnH2n+1 or CmH2m+1
n or m
Alkyl group


—CF2O—
Q
Difluoromethoxy bridge bond


—OCF2H
OCF2H
Difluoromethoxy







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A
2,5-tetrahydropyran







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D
2,6-dioxo-1,4-dioxane





—(CH2)n
n
Alkylene


—C≡C—
T
Acetylenic bond


—HC═CH—
V
Alkenyl









Taking the following compound structures as an example:




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is represented as 4CDUQKF




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is represented as 5CCPUF


In each of the following examples, the liquid crystal compositions are all prepared by a thermal dissolution method, comprising the following steps of: weighing liquid crystal compounds in percentage by weight using a balance, wherein the order of weighing and addition is not particularly specified, and usually, the weighing and mixing are carried out successively in order of the melting points of the liquid crystal compounds from high to low; heating and stirring same at 60-100° C. so that each component is melted uniformly; then subjecting same to filtration and rotary evaporation; and finally performing encapsulation to obtain a target sample.


In each of the following examples, the weight percentage of each component in the liquid crystal composition and the performance parameters of the liquid crystal composition are shown in the following tables.







EXAMPLE 1









TABLE 2







Percentages by weight of each component and


performance parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
2APUQKF
5
Δn
0.098


I
3PGUQKF
6
Δε
+2.6


II
3CCV1
12
Cp
81


II
1PP2V1
7
γ1
50


II
3CCV
43
K11
13.9


III
VCCP1
11
K22
7.0


III
V2CCP1
9.5
K33
15.6


VII
2PGP3
6


IX
3PPGUF
0.5









EXAMPLE 2









TABLE 3







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CPPQKF
3
Δn
0.122


II
3CCV
51
Δε
+2.3


II
3CCV1
7
Cp
75


VI
3PGUF
11
γ1
46


VII
1PGP2V
7
K11
12.2


VII
2PGP2V
8
K22
6.1


VII
V2PGP1
13
K33
14.0









EXAMPLE 3









TABLE 4







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
2APUQKF
5
Δn
0.098


I
3PGUQKF
5
Δε
+2.6


II
3CCV
43
Cp
81


II
3CCV1
12
γ1
49


II
1PP2V1
7
K11
13.8


III
VCCP1
11
K22
6.9


III
V2CCP1
9
K33
16.2


VII
2PGPF
6


IX
3PPGUF
2









EXAMPLE 4









TABLE 5







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CPPQKF
6
Δn
0.117


II
3CCV
40
Δε
+5.2


II
5PP1
7
Cp
81


III
VCCP1
6
γ1
48


III
3CCP1
5
K11
12.8


IV
3CCPOCF3
5
K22
6.3


V
2CGUF
4
K33
13.6


V
3CPGF
6


VI
2PGUF
10


VII
2PGPF
7


IX
3CCPUF
4









EXAMPLE 5









TABLE 6







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
4DGUQKF
2
Δn
0.101


I
3CPPQKF
9
Δε
+5.8


I
3CPUQKF
5
Cp
91


I
3PUQKF
11
γ1
62


II
3CC2V1
4
K11
13.8


II
3CCV1
5
K22
6.9


II
3CCV
35
K33
17.1


III
VCPP3
8


III
V2CCP1
10


III
VCCP1
11









EXAMPLE 6









TABLE 7







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CCQKF
19
Δn
0.098


II
5CCV
13
Δε
+9.4


II
3CCV1
4
Cp
101


IV
2CCUF
8
γ1
111


IV
3CCUF
8
K11
11.0


IV
2CCGF
3
K22
5.5


IV
3CCGF
3
K33
15.7


IV
5CCGF
3


V
3CPUF
23


IX
2CCPUF
4


IX
3CCPUF
4


IX
4CCPUF
4


IX
5CCPUF
4









EXAMPLE 7









TABLE 8







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CUQKF
7
Δn
0.116


I
3PUQKF
17
Δε
+9.0


II
3CCV
22
Cp
90


III
VCCP1
10
γ1
95


III
V2CCP1
7
K11
12.8


IV
3CCPOCF3
5
K22
6.4


V
3CPUF
10
K33
16.5


VII
2PGP3
6


IX
2CCPUF
4


IX
3CCPUF
5


IX
4CCPUF
4


IX
3CCGUF
3









EXAMPLE 8









TABLE 9







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PUQKF
16
Δn
0.116


II
3CCV1
8
Δε
+9.0


II
5CCV
14
Cp
94


IV
VCCGF
5
γ1
105


IV
3CCUOCF2H
10
K11
13.0


IV
3CCPOCF3
5
K22
6.5


IV
5CCPOCF3
5
K33
16.6


V
3CPUF
15


VII
2PGPF
5


VII
2PGP3
3


VIII
3CPPC3
4


IX
3CCGUF
5


IX
3CCPUF
5









EXAMPLE 9









TABLE 10







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
2
Δn
0.111


I
4PGUQKF
8
Δε
+7.5


I
3PUQKF
12
Cp
75


II
3CCV
45
γ1
45


IV
3CCUF
10
K11
10.5


VII
2PGP3
10
K22
5.3


VII
2PGP4
4
K33
13.0


IX
2CCPUF
3


IX
3CCPUF
3


IX
4CCPUF
3









EXAMPLE 10









TABLE 11







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3APUQKF
14
Δn
0.096


I
3CCQKF
13
Δε
+12.5


I
3PUQKF
12
Cp
90


II
3CCV
24
γ1
76


III
VCCP1
9
K11
11.0


IV
2CCUF
5
K22
5.5


IV
3CCUF
10
K33
13.6


IV
3CCPOCF3
5


IX
3CCGUF
4


IX
2CCPUF
4









EXAMPLE 11









TABLE 12







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CDUQKF
13
Δn
0.097


I
2APUQKF
10
Δε
12.8


I
3APUQKF
5
Cp
89


I
3PUQKF
10
γ1
67


II
3CCV
42
K11
12.9


III
VCCP1
6
K22
6.5


IX
3CCGUF
5
K33
15.0


IX
2CCPUF
5


IX
3CCPUF
4









EXAMPLE 12









TABLE 13







Percentages by weight of each component and


performance parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CCQKF
15
Δn
0.100


I
3GUQKF
5
Δε
+8.7


I
3APUQKF
9
Cp
100


I
3PGUQKF
5
γ1
80


II
3CCV
34
K11
13.6


II
3CCV1
2
K22
6.9


III
VCCP1
2
K33
17.0


IV
3CCUF
9


IV
3CCPOCF3
5


VIII
3CPPC3
3


IX
3CCGUF
5


IX
3CPGUOCF3
6









EXAMPLE 13









TABLE 14







Percentages by weight of each component and


performance parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3CPPQKF
3
Δn
0.122


II
3CCV
50
Δε
+2.4


II
3CCV1
9
Cp
75


VI
2PGUF
11
γ1
46


VII
1PGP2V
6
K11
12.2


VII
2PGP2V
8
K22
6.1


VII
V2PGP1
13
K33
12.8









EXAMPLE 14









TABLE 15







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PUQKF
9
Δn
0.116


II
3CCV
38
Δε
+5.2


II
3CCV1
10
Cp
75


III
VCCP1
3
γ1
46


III
V2CCP1
9
K11
12.5


VI
2PGUF
8
K22
6.3


VI
3PGUF
9
K33
12.8


VII
2PGP3
5


VII
2PGP4
5


VIII
3CPPC3
4









EXAMPLE 15









TABLE 16







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
2APUQKF
10
Δn
0.101


I
3PUQKF
15
Δε
+9.3


I
3APUQKF
2
Cp
80


II
3CCV
42
γ1
54


III
VCCP1
9
K11
10.9


IV
3CCPOCF3
10
K22
5.5


IX
3PPGUF
2
K33
15.0


IX
3CPGUOCF3
10









EXAMPLE 16









TABLE 17







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PUQKF
8
Δn
0.100


II
3CCV
27
Δε
+6.3


II
3CCV1
5
Cp
90


III
VCCP1
13
γ1
68


III
V2CCP1
11
K11
12.2


IV
VCCGF
6
K22
6.1


IV
3CCUF
4
K33
16.0


V
3CPUF
9


V
3CGUF
7


VI
2PGUF
3


IX
3CCGUF
7









EXAMPLE 17









TABLE 18







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PUQKF
15
Δn
0.100


II
3CCV
32
Δε
+6.3


III
3CCP1
7
Cp
90


III
3CCP2
6
γ1
71


III
3CCP3
3
K11
13.5


III
3CPP2
3
K22
6.8


IV
2CCGF
6
K33
16.0


IV
3CCGF
10


V
3CPGF
6


IX
2CCPUF
4


IX
3CCPUF
4


IX
4CCPUF
4









EXAMPLE 18









TABLE 19







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PUQKF
15
Δn
0.100


II
3CCV
32
Δε
+6.2


III
VCCP1
10
Cp
90


III
V2CCP1
6
γ1
68


III
VCPP3
3
K11
13.2


IV
VCCGF
6
K22
6.6


IV
3CCPOCF3
10
K33
15.8


V
3CPGF
6


IX
2CCPUF
4


IX
3CCPUF
4


IX
4CCPUF
4









EXAMPLE 19









TABLE 20







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
2APUQKF
5.5
Δn
0.098


I
3PGUQKF
6
Δε
+2.6


II
3CCV1
12
Cp
81


II
5PP1
6
γ1
51


II
3CCV
43
K11
13.8


III
VCCP1
11
K22
6.9


III
V2CCP1
7
K33
15.4


III
VCPP3
3.5


VII
2PGPF
6









EXAMPLE 20









TABLE 21







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
4
Δn
0.099


I
3PUQKF
16
Δε
+7.8


II
3CCV
33
Cp
91


II
3CCV1
3
γ1
70


II
5PP1
5
K11
12.5


III
3CCP1
6
K22
6.3


IV
2CCGF
6
K33
17.5


IV
3CCGF
9


IV
3CCPOCF3
6


IX
2CCPUF
4


IX
3CCPUF
4


IX
4CCPUF
4









EXAMPLE 21









TABLE 22







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
12
Δn
0.101


I
3PGUQKF
4
Δε
+5.8


II
3CCV
34
Cp
91


II
3CCV1
5
γ1
62


II
5PP1
7
K11
13.7


III
3CPP2
6
K22
6.9


III
VCCP1
3
K33
16.8


III
3CCP1
6


IV
3CCPOCF3
7


IV
3CCGF
8


IX
3CCPGF
4


IX
3CCPGOCF3
4









EXAMPLE 22









TABLE 23







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
2APUQKF
6
Δn
0.098


I
3PGUQKF
6
Δε
+2.6


II
3CCV1
12
Cp
80


II
5PP1
8
γ1
51


II
3CCV
43
K11
13.8


III
VCCP1
9
K22
6.9


III
V2CCP1
7
K33
15.4


III
VCPP3
3


III
3CPP2
6









EXAMPLE 23









TABLE 24







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
7.5
Δn
0.098


II
3CCV
42
Δε
+2.6


II
3CCV1
10
Cp
80


II
5PP1
7
γ1
51


III
VCCP1
13
K11
13.6


III
V2CCP1
12
K22
6.8


VII
2PGPF
7
K33
16.0


VII
3PGPF
1.5









EXAMPLE 24









TABLE 25







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
7.5
Δn
0.098


II
3CCV
40
Δε
+2.6


II
3CCV1
11
Cp
81


II
5PP1
8
γ1
50


III
VCCP1
14
K11
14.2


III
V2CCP1
7
K22
7.1


III
3CCP1
5
K33
15.7


VII
2PGPF
7.5









EXAMPLE 25









TABLE 26







Percentages by weight of each component and performance


parameters of the liquid crystal composition













Percentages by
Performance
Parameter


Types
Compound codes
weight
parameters
values














I
3PGUQKF
4
Δn
0.102


I
3PUQKF
10
Δε
+5.8


I
2APUQKF
5
Cp
90


II
3CCV
40
γ1
64


II
3CCV1
5
K11
13.5


III
VCCP1
12
K22
6.8


III
3CPP2
5
K33
16.7


III
3CCP1
4


IV
3CCPOCF3
4


VII
2PGPF
5


IX
3CCPGF
3


IX
5CCPGF
3









COMPARATIVE EXAMPLE 1

As compared with methyl-free compounds, the compounds of type I provided by the present invention have a mutual solubility with an improvement of 30% or greater. The experimental method is a conventional method for low temperature observation and implementation: adding same in percentage by mass into a host LC, and pouring into a liquid crystal cell at −40° C., and the specific results thereof can be found in the following table:









TABLE 27







Low temperature mutual solubility comparison












Addi-







tion


propor-
Host


tions
LC
3APUQUF
3APUQKF
3PGUQUF
3PGUQKF






OK






10

OK
OK
NG
OK


15

NG
OK

OK


20


OK

NG









As compared with methyl-free single crystals, the single crystal provided by the invention still maintains a good low temperature mutual solubility when the added mass is 5% more, and it can be seen therefrom that the single crystal of type I provided by the present invention has an excellent low temperature mutual solubility and can effectively improve the low temperature stability of the liquid crystal composition.


COMPARATIVE EXAMPLE 2









TABLE 28







Percentages by weight of each component and performance


parameters of the liquid crystal composition











Percentages by
Performance
Parameter


Compound codes
weight (%)
parameters
values













2PGP3
4
Δn
0.097


3CCV
43
Δε
+2.5


3CCV1
12
Cp
78


5PP1
4
γ1
53


2PGUF
6
K11
13.8


3PGUF
5
K22
6.9


VCCP1
11
K33
14.6


V2CCP1
10


3CPGUOCF3
5









The values of the performance parameters of the liquid crystal compositions obtained in example 1 and comparative example 1 are summarized and compared, and reference can be made to table 29.









TABLE 29







Comparison of performance parameters of liquid crystal compositions















Δn
Δε
Cp
γ1
K11
K22
K33


















Example 1
0.098
+2.6
81
50
13.9
7.0
15.6


Comparative
0.097
+2.5
78
53
13.8
6.9
14.6


example 1









Upon comparison, it can be seen that, as compared with comparative example 1, the liquid crystal composition provided in example 1 has a low rotational viscosity, i.e. having a faster response time.


COMPARATIVE EXAMPLE 3









TABLE 30







Percentages by weight of each component and performance


parameters of the liquid crystal composition











Percentages by
Performance
Parameter


Compound codes
weight (%)
parameters
values













3PUQUF
7
Δn
0.100


3CUQUF
7
Δε
+5.6


2PGUF
7
Cp
90


3CCV
35
γ1
90


3CCV1
8
K11
12.8


VCCP1
10
K22
6.5


V2CCP1
6
K33
16.2


2PGP3
4


2CCPUF
5


3CCPUF
5


3CPPC3
4


3CGPC3
2









The values of the performance parameters of the liquid crystal compositions obtained in example 5 and comparative example 2 are summarized and compared, and reference can be made to table 31.









TABLE 31







Comparison of performance parameters of liquid crystal compositions















Δn
Δε
Cp
γ1
K11
K22
K33


















Example 5
0.101
+5.8
91
62
13.8
6.9
17.1


Comparative
0.100
+5.6
90
90
12.8
6.5
16.2


example 2









Upon comparison, it can be seen that, as compared with comparative example 2, the liquid crystal composition provided in example 5 has a large elastic constant and a low rotational viscosity, and therefore has a shorter response time and a faster response speed.


It can be seen from the above examples that the liquid crystal composition provided by the present invention simultaneously contains a compound containing 2-methyl-3,4,5-trifluorobenzene linked to a difluoromethoxy bridge bond and a non-polar bicyclic compound, has a low viscosity, high resistivity, suitable optical anisotropy, large elastic constant and excellent light stability and thermal stability, and can reduce the response time of the liquid crystal display, thereby solving the problem of a slow response speed of the liquid crystal display. Therefore, the liquid crystal composition provided by the present invention is suitable for fast-response TN, IPS and FFS-type TFT liquid crystal display devices, is particularly suitable for IPS and FFS liquid crystal display devices, and is especially suitable for quick-response liquid crystal display devices.


Although the present invention has been described in detail with general explanations and specific embodiments, it is obvious to a person skilled in the art that some modifications or improvements can be made thereto based on the present invention. Therefore, all these modifications and improvements which can be made without departing from the scope of the present invention belong to the scope claimed in the invention.


INDUSTRIAL APPLICABILITY

The present invention provides a liquid crystal composition, which liquid crystal composition simultaneously contains a compound containing 2-methyl-3,4,5-trifluorobenzene linked to a difluoromethoxy bridge bond and a non-polar bicyclic compound, has a low viscosity, high resistivity, suitable optical anisotropy, large elastic constant and excellent light stability and thermal stability, and can reduce the response time of the liquid crystal display, thereby solving the problem of a slow response speed of the liquid crystal display. Therefore, the liquid crystal composition provided by the present invention is suitable for fast-response TN, IPS and FFS-type TFT liquid crystal display devices, is particularly suitable for IPS and FFS liquid crystal display devices, and is especially suitable for quick-response liquid crystal display devices, and has broad application prospects and a good industrial applicability in the liquid crystal display field.

Claims
  • 1. A liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound, comprising, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II,
  • 2. The liquid crystal composition according to claim 1, comprising, in percentages by weight, 3-20% of one or more compounds represented by general formula I, and 17-63% of one or more compounds represented by general formula II; or comprising 21-45% of one or more compounds represented by general formula I, and 20-45% of one or more compounds represented by general formula II.
  • 3. The liquid crystal composition according to claim 1, further comprising 0-30% by weight of one or more compounds represented by general formula III,
  • 4. The liquid crystal composition according to claim 3, wherein the amount of the one or more compounds represented by general formula III is 10-26% by weight.
  • 5. The liquid crystal composition according to claim 1, further comprising 6-45% by weight of one or more compounds represented by general formulas IV to IX,
  • 6. The liquid crystal composition according to claim 5, wherein the amount of the one or more compounds represented by general formulas IV to IX is 28-37%.
  • 7. The liquid crystal composition according to claim 5, comprising, in percentages by weight, 6-39% of one or more compounds represented by general formula I,22-62% of one or more compounds represented by general formula II,2-26% of one or more compounds represented by general formula III, and6-44% of one or more compounds represented by general formulas IV to IX.
  • 8. The liquid crystal composition according to claim 1, wherein the compound represented by general formula I is selected from one or more of the compounds represented by formulas I-A to I-U:
  • 9. The liquid crystal composition according to claim 1, wherein the compound represented by general formula I is selected from one or more of the compounds represented by formulas I-A-1 to I-U-4:
  • 10. The use of the liquid crystal composition of claim 1 in TN, IPS and FFS mode liquid crystal displays
Priority Claims (1)
Number Date Country Kind
201510030582.2 Jan 2015 CN national
PCT Information
Filing Document Filing Date Country Kind
PCT/CN2015/092665 10/23/2015 WO 00