Liquid crystal composition and application thereof

Abstract

A liquid crystal composition and use thereof in the liquid crystal display field. The liquid crystal composition includes, in percentages by weight, 5-40% of one or more compounds represented by general formula I, 2-30% of one or more compounds represented by general formula II, and 20-70% of one or more compounds represented by general formula III, and may further include 4-30% of one or more compounds represented by general formula IV and/or 5-25% of one or more compounds represented by general formulas V to IX. The combined use of the above-mentioned compounds can effectively reduce the rotational viscosity of the liquid crystal composition, improve related properties of the mixed liquid crystal, and thus reduce the response time thereof. The liquid crystal composition can be used for a fast-response liquid display in a variety of display modes.

Claims

1. A liquid crystal composition, comprising, in percentages by weight, 5-40% of one or more compounds represented by general formula I, 2-30% of one or more compounds represented by general formula II, and 20-70% of one or more compounds represented by general formula III, ##STR00057## wherein R.sub.1 independently represents a C.sub.1-C.sub.12 linear alkyl group or a C.sub.2-C.sub.12 linear alkenyl group; and R.sub.2 independently represents a C.sub.1-C.sub.12 linear alkyl group, a C.sub.1-C.sub.12 linear alkoxy group or a C.sub.2-C.sub.12 linear alkenyl group; R.sub.4 and R.sub.5 each independently represent an unsubstituted C.sub.1-C.sub.12 linear alkyl group or a C.sub.1-C.sub.12 linear alkyl group having one or more non-adjacent CH.sub.2 substituted with O, S or CHCH; X.sub.1 independently represents F, CI, CN, a C.sub.1-C.sub.12 linear alkyl group, a C.sub.1-C.sub.12 linear alkoxy group or a C.sub.2-C.sub.12 linear alkenyl group; Z.sub.1 and Z.sub.2 each independently represent a single bond or an acetylenic bond, with at least one of Z.sub.1and Z.sub.2 being an acetylenic bond; L.sub.1 independently represents H or F; A.sub.1, A.sub.2 and A.sub.3 each independently represent: ##STR00058## A.sub.4 independently represents: ##STR00059## A.sub.5 and A.sub.6 each independently represent a trans-1,4-cyclohexylene group or a 1,4-phenylene group; and m and n each independently represent 0 or 1.

2. The liquid crystal composition according to claim 1, further comprising 4-24% by weight of a compound represented by general formula IV, ##STR00060## wherein R.sub.6 and R.sub.7 each independently represent a C.sub.1-C.sub.12 linear alkyl group or a C.sub.1-C.sub.12 linear alkyl group having one or more non-adjacent CH.sub.2 substituted with O, S or CHCH; and A.sub.7 is selected from one of the following structures: ##STR00061##

3. The liquid crystal composition according to claim 2, further comprising 9-25% by weight of compounds represented by general formulas V to IX, ##STR00062## wherein R.sub.10 independently represents a C.sub.1-C.sub.12 linear alkyl group or a C.sub.2-C.sub.12 linear alkenyl group; R.sub.8, R.sub.9 and R.sub.11-R.sub.13 each independently represent a C.sub.1-C.sub.12 linear alkyl group; X.sub.2-X.sub.5 each independently represent F, CF.sub.3, OCF.sub.3 or OCF.sub.2H; L.sub.2-L.sub.9 each independently represent H or F; and A.sub.8 and A.sub.9 each independently represent: ##STR00063##

4. The liquid crystal composition according to claim 3, comprising, in percentages by weight, 9-12% of one or more compounds represented by general formula I, 5-26% of one or more compounds represented by general formula II, 60-67% of one or more compounds represented by general formula III, and 5-24% of one or more compounds represented by general formula IV.

5. The liquid crystal composition according to claim 3, comprising, in percentages by weight, 14-30% of one or more compounds represented by general formula I, 3-9% of one or more compounds represented by general formula II, 30-50% of one or more compounds represented by general formula III, 4-18% of one or more compounds represented by general formula IV, and 9-23% of one or more compounds represented by general formulas V to IX.

6. 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: ##STR00064## ##STR00065## ##STR00066## wherein R.sub.1 independently represents a C.sub.1-C.sub.7 linear alkyl group; and the compound represented by general formula II is selected from one or more of formulas II-A to II-D: ##STR00067## wherein R.sub.2 independently represents a C.sub.1-C.sub.7 linear alkyl group or a C.sub.2-C.sub.7 linear alkenyl group; and R.sub.3 independently represents a C.sub.1-C.sub.7 linear alkyl group, a C.sub.1-C.sub.7 linear alkoxy group or a C.sub.2-C.sub.7 linear alkenyl group; and the compound represented by general formula Ill is selected from one or more of the following compounds: ##STR00068## wherein R.sub.4 independently represents a C.sub.1-C.sub.7 linear alkyl group; and R.sub.5 independently represents a C.sub.1-C.sub.7 linear alkyl group or linear alkoxy group or a C.sub.2-C.sub.7 linear alkenyl group.

7. 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: ##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## the compound represented by general formula II is selected from one or more of formulas II-A-1 to II-D-16: ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## and the compound represented by general formula Ill is selected from one or more of the compounds represented by formulas III-A-1 to III-C-24: ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093##

8. The liquid crystal composition according to claim 2, wherein the compound represented by general formula IV is selected from one or more of the structures of formulas IV-A-1 to IV-C-30: ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100##

9. The liquid crystal composition according claim 3, wherein the compounds of general formulas V to IX are selected from one or more of the formulas V-A to IX-N: ##STR00101## ##STR00102## ##STR00103## ##STR00104## wherein R.sub.10 independently represents a C.sub.2-C.sub.7 linear alkyl group or linear alkenyl group; and R.sub.8, R.sub.9 and R.sub.11-R.sub.13 each independently represent a C.sub.2-C.sub.7 linear alkyl group.

10. The liquid crystal composition of claim 1, comprising, in percentages by weight, 9-30% of the one or more compounds represented by the general formula I, 3-26% of the one or more compounds represented by the general formula II, and 36-67% of the one or more compounds represented by the general formula III.

Description

SPECIFIC EMBODIMENTS

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

(2) Unless otherwise indicated, the percentage in the present invention is weight percentage; the temperature unit is degrees Celsius; n represents optical anisotropy (at 25 C.); represents dielectric anisotropy (at 25 C., 1000 Hz); V.sub.10 represents voltage threshold, and is the characteristic voltage (V, at 25 C.) when the relative transmittance is changed by 10%; 1 represents rotational viscosity (mPa.Math.S, at 25 C.); Cp represents the clearing point ( C.) of the liquid crystal composition; and K.sub.11, K.sub.22 and K.sub.33 represent splay, twist and bend elastic constants (pN, at 25 C.), respectively.

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

(4) TABLE-US-00001 TABLE 1 Group structure codes of the liquid crystal compound Groups Codes Group names C 1,4-cyclohexylene P 1,4-phenylene 0 G 2-fluoro-1,4-phenylene U 2,6-difluoro-1,4-phenylene O O Oxygen substituent F F Fluorine substituent CF.sub.3 CF.sub.3 Trifluoromethyl C.sub.nH.sub.2n+1 or C.sub.mH.sub.2m+1 n or m Alkyl group CF.sub.2O Q Difluoromethoxy bridge bond OCHF.sub.2 OCHF.sub.2 Difluoromethoxy A 2,5-tetrahydropyran D 2,6-dioxo-1,4-dioxane K 2-methyl-3,5-difluoro-1,4- phenylene OCF.sub.2CFCF.sub.2 X Pentafluoropropenyl ether CC T Acetylenic bond HCCH V Alkenyl
Taking the following compound structures as an example:

(5) ##STR00055##

(6) is represented as 4CDUQKF, and

(7) ##STR00056##

(8) is represented as 5CCPUF

(9) 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.

(10) 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

(11) TABLE-US-00002 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 3PGUQKF 3 n 0.098 I 3PUQKF 5 +2.6 I 2APUQKF 3 Cp 80 II 3CPTP2 5 1 50 III 3CCV 43 K.sub.11 13.9 III 3CCV1 12 K.sub.22 7.0 III 5PP1 5 K.sub.33 16.1 IV VCCP1 10 IV V2CCP1 7 IV VCPP3 7

EXAMPLE 2

(12) TABLE-US-00003 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 3PGUQKF 5 n 0.098 I 3DUQKF 5 +2.8 II 3CPTP2 11 Cp 75 III 3CCV 44 1 48 III 3CCV1 13 K.sub.11 12.8 III 5PP1 10 K.sub.22 6.4 IV VCCP1 12 K.sub.33 14.8

EXAMPLE 3

(13) TABLE-US-00004 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 3PGUQKF 5 n 0.099 I 2APUQKF 4.5 +2.6 II 3CPTP2 7 Cp 81 III 3CCV 43 1 52 III 3CCV1 12 K.sub.11 13.8 III 5PP1 9 K.sub.22 6.9 IV VCCP1 10 K.sub.33 15.9 IV V2CCP1 4.5 IV VCPP3 5

EXAMPLE 4

(14) TABLE-US-00005 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 3PGUQKF 4 n 0.101 I 3PUQKF 10 +5.8 I 2APUQKF 5 Cp 90 II 3CPTP2 5 1 63 III 3CCV 40 K.sub.11 13.9 III 3CCV1 5 K.sub.22 7.0 IV 3CCP1 5 K.sub.33 16.7 IV 3CPP2 6 IV VCCP1 5 VII 3CCPOCF3 6 VII 5CCPOCF3 4 VII 2CCGF 5

EXAMPLE 5

(15) TABLE-US-00006 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 3PGUQKF 5 n 0.114 I 3PUQKF 9 +5.2 II 3CPTP2 9 Cp 75 III 3CCV 38 1 48 III 3CCV1 5 K.sub.11 12.8 III 5PP1 7 K.sub.22 6.6 IV VCPP3 4 K.sub.33 13.5 V 2CPGF 7 V 3CPGF 6 VII 2CCGF 4 VII 3CCPOCF.sub.3 6

EXAMPLE 6

(16) TABLE-US-00007 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 3PUQKF 12 n 0.105 I 5PUQKF 12 +7.8 I 4DUQKF 3 Cp 90 II 3CPTP2 4 1 75 III 3CCV 35 K.sub.11 12.4 III 3CCV1 5 K.sub.22 6.2 IV VCCP1 14 K.sub.33 17.0 V 3CPGF 8 VIII 3CGPC3 4 IX 3CCPUF 3

EXAMPLE 7

(17) TABLE-US-00008 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 3PUQKF 10 n 0.104 I 5PUQKF 10 +7.5 I 3PGUQKF 3 Cp 91 I 3DUQKF 3 1 74 I 3DPUQKF 3 K.sub.11 13.8 II 3CPTP2 4 K.sub.22 6.9 III 3CCV 30 K.sub.33 17.0 III 3CCV1 5 III 3CC2V1 5 IV VCCP1 12 IV V2CCP1 6 V 3CPGF 9

EXAMPLE 8

(18) TABLE-US-00009 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 10 n 0.105 I 5PUQKF 5 +11.5 I 3PGUQKF 2 Cp 94 I 3DUQKF 4 1 82 I 4DUQKF 5 K.sub.11 13.1 I 4DPUQKF 4 K.sub.22 6.6 II 4CPTP1 3 K.sub.33 16.9 III 3CCV 33 III 3CCV1 3 IV VCCP1 6 V 3CPGF 9 VII 3CCGF 7 IX 2CCPUF 3 IX 3CCPUF 3 IX 5CCPUF 3

EXAMPLE 9

(19) TABLE-US-00010 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 3PUQKF 12 n 0.100 I 3PGUQKF 3 +5.8 I 2APUQKF 4 Cp 91 I 3DPUQKF 3 1 65 II 3CPTP2 4 K.sub.11 13.9 III 3CCV 30 K.sub.22 7.0 III 3CCV1 5 K.sub.33 16.8 III 3CC2V1 5 III 5PP1 7 IV VCCP1 12 IV V2CCP1 6 VII 3CCGF 9

EXAMPLE 10

(20) TABLE-US-00011 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 3PGUQKF 5 n 0.122 I 3PUQKF 4 +2.4 II 3CPTP2 10 Cp 80 II 3PTP1 6 1 49 II 4PTP1 5 K.sub.11 13.5 II 2PTP1 5 K.sub.22 6.8 III 3CCV 44 K.sub.33 16.2 III 3CCV1 9 III 1V2PP1 7 IV VCCP1 5

EXAMPLE 11

(21) TABLE-US-00012 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 3PGUQKF 5 n 0.100 I 5PGUQKF 3 +3.4 I 4DPUQKF 2 Cp 75 I 3APUQKF 2 1 49 II 3CPTP2 9 K.sub.11 12.8 II V2PTP2V 5 K.sub.22 6.4 III 3CCV 44 K.sub.33 14.6 III 4CCV 5 III 3CCV1 12 III 5PP1 5 IV VCCP1 8

Comparative Example 1

(22) TABLE-US-00013 TABLE 13 Percentages by weight of each component and performance parameters of the liquid crystal composition Percentages by Performance Parameter Compound codes weight parameters values 3PGUQUF 7 n 0.098 3APUQUF 5 +2.6 2PGP3 6 Cp 81 3CCV 42 1 52 3CCV1 12 K.sub.11 13.8 1V2PP1 7 K.sub.22 6.9 VCCP1 11 K.sub.33 16.0 V2CCP1 10

(23) 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 14.

(24) TABLE-US-00014 TABLE 14 Comparison of performance parameters of liquid crystal compositions n Cp 1 K.sub.11 K.sub.22 K.sub.33 Example 1 0.098 +2.6 80 50 13.9 7.0 16.1 Comparative 0.098 +2.6 81 52 13.8 6.9 16.0 example 1

(25) 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 and a large elastic constant, and therefore has a shorter response time and a faster response speed.

Comparative Example 2

(26) TABLE-US-00015 TABLE 15 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 n 0.100 3CUQUF 7 +5.8 2PGUF 7 Cp 90 3CCV 35 1 90 3CCV1 8 K.sub.11 12.8 VCCP1 10 K.sub.22 6.5 V2CCP1 6 K.sub.33 16.2 2PGP3 4 2CCPUF 5 3CCPUF 5 3CPPC3 4 3CGPC3 2

(27) The values of the performance parameters of the liquid crystal compositions obtained in example 9 and comparative example 2 are summarized and compared, and reference can be made to table 16.

(28) TABLE-US-00016 TABLE 16 Comparison of performance parameters of liquid crystal compositions n Cp 1 K.sub.11 K.sub.22 K.sub.33 Example 9 0.100 +5.8 91 65 13.9 7.0 16.8 Comparative 0.100 +5.8 90 90 12.8 6.5 16.2 example 2

(29) Upon comparison, it can be seen that, as compared with comparative example 2, the liquid crystal composition provided in example 9 has a low rotational viscosity and a large elastic constant, and therefore has a shorter response time and a faster response speed.

(30) 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

(31) The liquid crystal composition provided by the present invention simultaneously contains a 2-methyl-3,4,5-trifluorophenyl compound, an acetylenic compound 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. In addition, the liquid crystal composition can effectively improve the contrast characteristics of IPS and FFS liquid crystal displays. 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, and has broad application prospects and a good industrial applicability in the liquid crystal display field.