LIQUID CRYSTAL COMPOSITION AND DISPLAY DEVICE THEREOF

Abstract

The present invention discloses a liquid crystal composition and a display device containing the same. The liquid crystal composition comprises one or more compounds of general Formula I; one or more compounds of general Formula II; and one or more compounds of general Formula III. The liquid crystal composition provided in the present invention has the properties of large optical and dielectric anisotropies, high clearing point, fast response speed, high resistivity, and good high-temperature and UV stability, and is applicable to a liquid crystal display (LCD), and particularly an LCD display requiring fast response speed, such that a good display effect of images without ghosting can be achieved when the LCD display works in a harsh environment.

##STR00001##

Claims

1. A liquid crystal composition, comprising: one or more compounds of general Formula I: ##STR00052## one or more compounds of general Formula II: ##STR00053## and one or more compounds of general Formula III: ##STR00054## wherein: R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the same or different, and each independently denotes H, a linear alkyl or alkoxy group having 1 to 7 carbon atoms, or an alkenyl group having 2 to 7 carbon atoms; ##STR00055## are the same or different, and each independently denotes ##STR00056## wherein one or more H atoms on the ##STR00057## may be replaced by F; ##STR00058## denotes ##STR00059## X denotes F or —OCF.sub.2CF=CF.sub.2; in denotes 1, 2 or 3; and n denotes 0 or 1.

2. The liquid crystal composition according to claim 1, wherein the compound of general Formula I accounts for 5-30% of the total weight of the liquid crystal composition; the compound of general Formula II accounts for 30-70% of the total weight of the liquid crystal composition; and the compound of general Formula III accounts for 15-40% of the total weight of the liquid crystal composition.

3. The liquid crystal composition according to claim 1, wherein the liquid crystal composition further comprising: one or more compounds of general Formula IV that account for 1-30% of the liquid crystal composition: ##STR00060## wherein: R.sub.5 denotes a linear alkyl or alkoxy group having 1 to 7 carbon atoms; ##STR00061## denotes ##STR00062## wherein one or more H atoms on the ##STR00063## may be replaced by F; and L.sub.1 and L.sub.2 are the same or different, and each independently denotes H or F.

4. The liquid crystal composition according to claim 1, wherein the compound of general Formula I is one or more selected from the group consisting of: ##STR00064##

5. The liquid crystal composition according to claim 1, wherein the compound of general Formula II is one or more selected from the group consisting of: ##STR00065## ##STR00066## wherein: R.sub.2 and R.sub.3 are the same or different, and each independently denotes a linear alkyl group having 1 to 5 carbon atoms.

6. The liquid crystal composition according to claim 1, wherein the compound of general Formula III is one or more selected from the group consisting of: ##STR00067## ##STR00068## wherein: R.sub.4 denotes a linear alkyl group having 1 to 5 carbon atoms.

7. The liquid crystal composition according to claim 5, wherein the compound of general Formula II-1 is one or more selected from the group consisting of: ##STR00069## the compound of general Formula II-2 is one or more selected from the group consisting of: ##STR00070## the compound of general Formula II-3 is one or more selected from the group consisting of: ##STR00071## the compound of general Formula II-4 is one or more selected from the group consisting of: ##STR00072## the compound of general Formula II-5 is one or more selected from the group consisting of: ##STR00073## the compound of general Formula II-6 is one or more selected from the group consisting of: ##STR00074## the compound of general Formula II-7 is one or more selected from the group consisting of: ##STR00075## the compound of general Formula II-8 is one or more selected from the group consisting of: ##STR00076## the compound of general Formula II-9 is one or more selected from the group consisting of: ##STR00077## the compound of general Formula II-10 is one or more selected from the group consisting of: ##STR00078## the compound of general Formula II-11 is one or more selected from the group consisting of: ##STR00079## and the compound of general Formula II-12 is one or more selected from the group consisting of: ##STR00080##

8. The liquid crystal composition according to claim 6, wherein the compound of general Formula III-1 is one or more selected from the group consisting of: ##STR00081## the compound of general Formula III-2 is one or more selected from the group consisting of: ##STR00082## the compound of general Formula III-6 is one or more selected from the group consisting of: ##STR00083## the compound of general Formula III-7 is one or more selected from the group consisting of: ##STR00084## the compound of general Formula III-8 is one or more selected from the group consisting of: ##STR00085## the compound of general Formula III-9 is one or more selected from the group consisting of: ##STR00086## the compound of general Formula III-10 is one or more selected from the group consisting of: ##STR00087## the compound of general Formula III-11 is one or more selected from the group consisting of: ##STR00088## and the compound of general Formula III-12 is one or more selected from the group consisting of: ##STR00089##

9. The liquid crystal composition according to claim 3, wherein the compound of general Formula IV is one or more selected from the group consisting of: ##STR00090## ##STR00091##

10. The liquid crystal composition according to claim 3, wherein the compound of general Formula I accounts for 5-15% of the total weight of the liquid crystal composition; the compound of general Formula II accounts for 40-60% of the total weight of the liquid crystal composition; the compound of general Formula III accounts for 20-25% of the total weight of the liquid crystal composition; and the compound of general Formula IV accounts for 5-20% of the total weight of the liquid crystal composition.

11. (canceled)

12. A liquid crystal display (LCD), wherein it comprises the liquid crystal composition according to claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0059] Hereinafter, the present invention is described with reference to specific embodiments. It should be noted that the examples below are illustrative of the present invention, and are provided merely for explaining, instead of limiting the present invention. Other combinations and various improvements may be made within the concept and without departing from the spirit and scope of the present invention.

[0060] For ease of description, in the following examples, the group structures contained in the liquid crystal compound are denoted by the codes listed in Table 1:

TABLE-US-00001 TABLE 1 Codes for group structures contained in the liquid crystal compound Unit structure of the group Code Name of the group [00042] C(5) Cyclopentane [00043] D(5) 2-tetrahydrofuran [00044] C 1,4-cyclohexylene [00045] A Oxane [00046] D Dioxane [00047] P 1,4-phenylene [00048] G 2-fluoro-1,4-phenylene [00049] U 2,6-difluoro-1,4-phenylene [00050] I Indan-2,5-diyl —F F Fluoro substituent —O— O Oxy substituent —CF.sub.2O— Q Difluoromethoxy —CH.sub.2CH.sub.2— 2 Ethylene —CH═CH— V Vinyl —C.sub.nH.sub.2n+1 or —C.sub.mH.sub.2m+1 n or m Alkyl

[0061] Taking a compound having a structural formula below as an example:

##STR00051##

[0062] if the structural formula is designated by the codes in Table 1, it may be expressed as nCPUF, where n denotes the number of carbon atoms contained in the alkyl group at the left end, for example, when n is “3”, the alkyl group is —C.sub.3H.sub.7; and C denotes cyclohexylene.

[0063] The test items in the following examples are abbreviated as follows: [0064] Cp (° C.): Clearing point (nematic-isotropic phase transition temperature) [0065] Δn: Optical anisotropy (589 nm, 20° C.) [0066] Δ∈: Dielectric anisotropy (1 KHz, 25° C.) [0067] RT: Response time (ins) [0068] VHR (starting): Voltage holding ratio (%) [0069] VHR (UV): Voltage holding ratio after 20 min sunlight exposure (%) [0070] VHR (150° C.): Voltage holding ratio determined after 1 h degradation at 150° C. (%) [0071] ρ: Resistivity (25° C., *10.sup.13 Ω.Math.cm)

[0072] The optical anisotropy is measured using abbe refractometer under sodium lamp (589 nm) light source at 20° C. The dielectric test cell is the type TN90, and the cell gap is 7 μm.

[0073] Δ∈=∈∥−∈⊥, wherein ∈∥ is the dielectric constant parallel to the molecular axis, and ∈⊥ is the dielectric constant perpendicular to the molecular axis; the test conditions include 25° C. and 1 KHz; and the test cell is the type TN90, and the cell gap is 7 μm.

[0074] The response time is tested by DMS505 at 25° C.; the test cell is the left-handed TN type, the cell gap is 7 μm, and the test voltage is 8 V.

[0075] VHR (starting) is tested by TOYO6254 liquid crystal physical property evaluation system, where the test temperature is 60° C., the test voltage is 5V, and the test time is 166.7 ms; VHR (150° C.) is tested by TOYO6254 liquid crystal physical property evaluation system after 1 h degradation of the liquid crystal at 150° C., where the test temperature is 60° C., the test voltage is 5 V, and the test time is 166.7 ms; and VHR (UV) is tested by TOYO6254 liquid crystal physical property evaluation system, where the test temperature is 60° C., the test voltage is 5 V, the test time is 166.7 ms, and the sunlight exposure time is 20 min.

[0076] Each of the components used in the following examples can be synthesized by a known method or is commercially available. These synthesis techniques are conventional and the resulting liquid crystal compounds are tested to conform to the standards for electronic compounds.

[0077] A liquid crystal composition is prepared according to a mixing ratio of the liquid crystal compounds defined in the following examples. The liquid crystal composition is prepared by a conventional method in the art, for example, mixing according to the defined ratio by heating, ultrasonicating, and suspending, etc.

Comparative Example 1

[0078] The liquid crystal composition of Comparative Example 1 was prepared with the compounds in percentages by weight shown in Table 2, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00002 TABLE 2 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CPPC3 II-10-2 4 Cp 74.6 2PGP3 5 Δn 0.106 5PGP2 5 Δε 5.6 2PGUF 7 RT 19.5 4PGP2 5 VHR (starting) 92.4 3PGUF 8 VHR (150° C.) 80.5 VCCP1 II-8-1 3 VHR (UV) 78.8 3CCV II-2-1 35 ρ 1.2 V2CCP1 10 3CCV1 II-3-1 8 3PUQUF III-1-2 10 In total 100

Example 1

[0079] The liquid crystal composition of Example 1 was prepared with the compounds in percentages by weight shown in Table 3, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00003 TABLE 3 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CPP2 II-9-2 10 Cp 101 3CPPC3 II-10-2 4 Δn 0.11 3CGPC2 II-11-2 4 Δε 8.2 3CCPF IV-1 4 RT 16 3CCUF IV-5 9 VHR (starting) 98.7 3CC2 II-1-1 9 VHR (150° C.) 93.1 2CCQUF III-6-1 5 VHR (UV) 90.2 3CCQUF III-6-2 5 ρ 6.8 3CCV II-2-1 25 3PUQUF III-1-2 5 2PUQUF III-1-1 5 3IGUQUF III-12-2 5 3PGPF I-2 4 4PGPF I-3 3 5PGPF I-4 3 In total 100

Example 2

[0080] The liquid crystal composition of Example 2 was prepared with the compounds in percentages by weight shown in Table 4, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00004 TABLE 4 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CCPO3 II-7-3 5 Cp 84.2 3CGPC2 II-11-2 5 Δn 0.12 3CPPF IV-3 5 Δε 8.9 5CC2 II-1-3 10 RT 15.1 3CCP1 II-6-1 5 VHR (starting) 97.6 3CCQUF III-6-2 5 VHR (150° C.) 92.1 3PGPC2 II-12-2 5 VHR (UV) 91.5 3CCV II-2-1 30 ρ 6.4 3PUQUF III-1-2 4 2IUQUF III-11-1 4 3IUQUF III-11-2 4 3PGUQUF III-2-1 4 5PGUQUF III-2-3 4 3PGPF I-2 5 4PGPF I-3 5 In total 100

Example 3

[0081] The liquid crystal composition of Example 3 was prepared with the compounds in percentages by weight shown in Table 5, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00005 TABLE 5 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CP2 II-4-2 8 Cp 72.6 3CGPC2 II-11-2 4 Δn 0.12 3CPGF IV-6 10 Δε 9.7 3CPUF IV-8 10 RT 15.6 3CC2 II-1-1 15 VHR (starting) 96.5 5CC2 II-1-3 10 VHR (150° C.) 91.3 VCCP1 II-8-1 5 VHR (UV) 90.4 C(5)PUQUF III-3 5 ρ 5.8 D(5)PUQUF III-4 5 3IUQUF III-11-2 5 3PGUQUF III-2-1 5 5PGUQUF III-2-3 5 3PGPF I-2 5 4PGPF I-3 4 5PGPF I-4 4 In total 100

Example 4

[0082] The liquid crystal composition of Example 4 was prepared with the compounds in percentages by weight shown in Table 6, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00006 TABLE 6 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CCV II-2-1 20 Cp 95 5CCV II-2-3 12 Δn 0.12 3CPUF IV-8 10 Δε 8.5 3CPP2 II-9-2 4 RT 14.9 3PGPC2 II-12-2 2 VHR (starting) 95.4 3CCUF IV-5 9 VHR (150° C.) 91.2 3CCPO1 II-7-1 9 VHR (UV) 89.6 2ACQUF III-7-1 4 ρ 6.1 3PUQUF III-1-2 4 3DUQUF III-10-2 4 3IUQUF III-11-2 5 3PGUQUF III-2-1 5 3PGPF I-2 4 4PGPF I-3 4 5PGPF I-4 4 In total 100

Example 5

[0083] The liquid crystal composition of Example 5 was prepared with the compounds in percentages by weight shown in Table 7, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00007 TABLE 7 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CCV II-2-1 20 Cp 92 3CCV1 II-3-1 10 Δn 0.12 3CPUF IV-8 10 Δε 9.7 5CPUF IV-9 5 RT 15.6 3CPP2 II-9-2 5 VHR (starting) 97.2 3PGPC2 II-12-2 2 VHR (150° C.) 93.9 3CC2 II-1-1 10 VHR (UV) 91.5 5CC2 II-1-3 8 ρ 6.8 3PUQUF III-1-2 4 3DUQUF III-10-2 4 3IUQUF III-11-2 5 3PGUQUF III-2-1 5 5PGUQUF III-2-3 5 3PGPF I-2 3 4PGPF I-3 4 In total 100

Example 6

[0084] The liquid crystal composition of Example 6 was prepared with the compounds in percentages by weight shown in Table 8, and then filled between two substrates of a liquid crystal display for performance test. The test data is shown in a table below.

TABLE-US-00008 TABLE 8 Formulation of liquid crystal composition and performances tested Code of Type of Test result of performance component compound Content, % parameters 3CPP2 II-9-2 10 Cp 95 3CPPC3 II-10-2 4 Δn 0.11 3CGPC2 II-11-2 4 Δε 8.6 3CCPF IV-1 4 RT 16 3CCUF IV-5 9 VHR (starting) 96.7 3CC2 II-1-1 9 VHR (150° C.) 93.1 C(5)CCQUF III-5 5 VHR (UV) 91.2 3DCQUF III-8-2 5 ρ 5.8 3CCV II-2-1 25 2AUQUF III-9-1 5 2ACQUF III-7-1 5 3IGUQUF III-12-2 5 3PGPF I-2 4 4PGPF I-3 3 5PGPF I-4 3 In total 100

[0085] As can be known from the data obtained in examples above, the liquid crystal composition provided in the present invention has the properties of large optical and dielectric anisotropies, fast response speed, high resistivity, good high-temperature stability, and UV stability, and is applicable to a liquid crystal display. Compared with Comparative Example 1, the liquid crystal composition provided in the present invention has larger optical and dielectric anisotropies, shorter response time, higher resistivity, and better high-temperature and UV stability, and can meet the requirement of high response speed for an LCD display, such that a good display effect of images without ghosting can be achieved when the liquid crystal display works in a harsh environment. Therefore, significant technical advancements are achieved.

[0086] The above embodiments are merely illustrative of the technical concepts and features of the present invention, and provided for facilitating the understanding and practice of the present invention by those skilled in the art. However, the protection scope of the invention is not limited thereto. Equivalent variations or modifications made without departing from the spirit and essence of the present invention are intended to be contemplated within the protection scope of the present invention.