LIQUID CRYSTAL COMPOSITION AND PHOTOELECTRIC DISPLAY DEVICE THEREOF

Abstract

A liquid crystal composition includes at least one compound of general Formula I in an amount of 1%-30% by weight of the total weight of the liquid crystal composition, at least one compound of general Formula II in an amount of 5%-35% by weight of the total weight of the liquid crystal composition, and at least one compound of general Formula III in an amount of 10%-50% by weight of the total weight of the liquid crystal composition. The liquid crystal composition has an appropriate clearing point, an appropriate optical anisotropy, an appropriate dielectric anisotropy, as well as a higher voltage holding ratio, a higher transmittance, a good high-temperature resistant performance and a faster response speed, thus being suitable for display modes, such as VA, IPS and FFS. A photoelectric display device includes the liquid crystal composition.

##STR00001##

Claims

1. A liquid crystal composition comprising: one or more compounds of general Formula I in an amount of 1%-30% by weight of the total weight of the liquid crystal composition ##STR00020## one or more compounds of general Formula II in an amount of 5%-35% by weight of the total weight of the liquid crystal composition ##STR00021## and one or more compounds of general Formula III in an amount of 10%-50% by weight of the total weight of the liquid crystal composition ##STR00022## wherein, R.sub.1, R.sub.3 and R.sub.5 each independently represents C.sub.1-7 alkyl or alkoxy; R.sub.2 and R.sub.4 each independently represents C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl or alkenoxy; wherein one or more —H in R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 can each be independently substituted by halogen, and one or more —CH.sub.2— in R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 can each be independently substituted by cyclopentyl, cyclopropyl or cyclobutyl; L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5 and L.sub.6 each independently represents —F, —Cl, —CF.sub.3, —OCF.sub.3 or —CH.sub.2F; ring A1 and ring A2 each independently represents 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene; wherein one or more —H on 1,4-phenylene may be substituted by halogen, and wherein one or more —CH.sub.2- in 1,4-cyclohexylene may be replaced by —O—; and n represents 0 or 1.

2. The liquid crystal composition according to claim 1, wherein the compound of general Formula I is selected from a group consisting of the following compounds: ##STR00023## the compound of general Formula II is selected from a group consisting of the following compounds: ##STR00024## wherein, R.sub.2 represents C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl, R.sub.3′ represents C.sub.1-7 alkyl, and m represents 0, 1 or 2; and the compound of general Formula III is selected from a group consisting of the following compounds: ##STR00025##

3. The liquid crystal composition according to claim 1, wherein the one or more compounds of general Formula I provides 5%-25% by weight of the total weight of the liquid crystal composition, the one or more compounds of general Formula II provides 5%-30% by weight of the total weight of the liquid crystal composition, and the one or more compounds of general Formula III provides 10%-50% by weight of the total weight of the liquid crystal composition.

4. The liquid crystal composition according to claim 1, further comprising: one or more compounds of general Formula IV in an amount of 10%-45% by weight of the total weight of the liquid crystal composition ##STR00026## wherein, R.sub.6 and R.sub.7 each independently represents C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl; Z.sub.1 represents single bond, —CH.sub.2CH.sub.2—, —CH═CH— or —CH.sub.2O—; and ring A3 represents 1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene.

5. The liquid crystal composition according to claim 4, wherein the one or more compounds of general Formula IV provides 20%-45% by weight of the total weight of the liquid crystal composition.

6. The liquid crystal composition according to claim 5, wherein the compound of general Formula IV is selected from a group consisting of the following compounds: ##STR00027##

7. The liquid crystal composition according to claim 1, further comprising: one or more compounds of general Formula V in an amount of 0%-20% by weight of the total weight of the liquid crystal composition ##STR00028## wherein, R.sub.8 and R.sub.9 each independently represents C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl.

8. The liquid crystal composition of any one according to claim 1, further comprising: one or more compounds of general Formula VI in an amount of 0%-5% by weight of the total weight of the liquid crystal composition ##STR00029## wherein, R.sub.10 and R.sub.11 each independently represents C.sub.1-7 alkyl or alkoxy, or C.sub.2-7 alkenyl or alkenoxy; L.sub.7 and L.sub.8 each independently represents —F, —Cl, —CF.sub.3, —OCF.sub.3 or —CH.sub.2F; Z.sub.2 and Z.sub.3 each independently represents single bond, —CH.sub.2CH.sub.2—, —COO—, —CH.sub.2O— or —CF.sub.2O—, and at least one of Z.sub.2 and Z.sub.3 is not single bond; ring A4 and ring A5 each independently represents1,4-cyclohexylene, 1,4-cyclohexenylene or 1,4-phenylene, wherein one or more —H on 1,4-phenylene may be substituted by halogen, and wherein one or more —CH.sub.2— in 1,4-cyclohexylene may be replaced by —O—; and m represents 0 or 1.

9. The liquid crystal composition according to claim 8, wherein the compound of general Formula VI is selected from a group consisting of the following compounds: ##STR00030## ##STR00031##

10. A photoelectric display device comprising the liquid crystal composition according to claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention will be illustrated by combining the detailed embodiments below. It should be noted that, the following examples are exemplary embodiments of the present invention, which are only used to illustrate the present invention, not to limit it. Other combinations and various modifications within the conception of the present invention are possible without departing from the subject matter and scope of the present invention.

[0055] For the convenience of the expression, the group structures of the liquid crystal compounds in the following Examples are represented by the codes listed in Table 1:

TABLE-US-00001 TABLE 1 Codes of the group structures of the liquid crystal compounds Unit structure of group Code Name of the group [00015] C 1,4-cyclohexylene [00016] P 1,4-phenylene [00017] L 1,4-cyclohexenylene [00018] W 2,3-difluoro-1,4-phenylene —CH.sub.2CH.sub.2— 2 ethyl bridge bond —CF.sub.3 CF3 trifluoromethyl —OCF.sub.3 OCF3 trifluoromethoxy —CH.sub.2F CH2F monofluoromethyl —F F fluoro substituent —O— O oxygen substituent —CF.sub.2O— Q difluoromethoxy —CH.sub.2O— 1O methyleneoxy —COO— E ester bridge bond —C.sub.nH.sub.2n+1 n (n represents a alkyl positive integer of 1-7) —CH═CH— or —CH═CH.sub.2 V ethenyl

[0056] Take the compound with the following structural formula as an example:

##STR00019##

Represented by the codes listed in Table 1, this structural formula can be expressed as 1VCPWO2, in which, “1” in the code represents that the group on the left is —CH.sub.3; “2” in the code represents the group on the right is —C.sub.2H.sub.5; “V” in the code represents —CH═CH—, “C” in the code represents 1,4-cyclohexylene; “P” in the code represents 1,4-phenylene; “W” in the code represents 2,3-difluoro-1,4-phenylene; and “O” in the code represents —O—.

[0057] The abbreviated codes of the test items in the following Examples are represented as follows: [0058] Δn optical anisotropy (589 nm, 25° C.) [0059] Δε dielectric anisotropy (1 KHz, 25° C.) [0060] Cp clearing point (nematic-isotropic phases transition temperature, ° C.) [0061] γ1 rotational viscosity (mPa*s, at 25° C.) [0062] V.sub.90 saturation voltage (characteristic voltage with 90% relative transmittance) [0063] τ.sub.off the time required to reduce the transmittance from 90% to 10% when removing the electric field (ms, 25° C.) [0064] T Transmittance (%, DMS 505 tester, cell gap 3.5 μm) [0065] VHR voltage holding ratio (%) [0066] I.sub.on (initial) initial ion concentration (pC/cm.sup.2, 60° C.) [0067] I.sub.on (high temperature) high-temperature ion concentration (pC/cm.sup.2, 150° C.) [0068] ΔI.sub.on difference in ion concentration (pC/cm.sup.2)

[0069] in which,

[0070] Cp is tested and obtained with melting point quantitative analysis;

[0071] Δn is tested and obtained with an Abbe refractometer under sodium lamp (589 nm) light source at 25° C.;

[0072] Δ.sub.ε=ε//−ε.sub.⊥, in which, ε.sub.// is the dielectric constant parallel to the molecular axis, ε.sub.⊥ is the dielectric constant perpendicular to the molecular axis, with the test conditions: 25±0.5° C., 1 kHz, VA type test cell with a cell gap of 6 μm;

[0073] γ1 is tested and obtained using INSTEC:ALCTIR1 at 25±0.5° C. with a parallel test cell having a cell gap of 20 μm;

[0074] V.sub.90 is tested and obtained with a DMS505 tester under the test conditions: 25° C., square wave/60 HZ, test voltage: 0-10 V;

[0075] τ.sub.off is the time required to reduce the transmittance from 90% to 10% when removing the electric field and is measured with a VA type test cell having a cell gap of 3.5 μm;

[0076] T of the optic-tunable device is measured at the temperature of 25° C. with a DMS505 tester under the test conditions: square wave/60 HZ, test voltage: 4V, VA type test cell having a cell gap of 3.5 μm;

[0077] VHR is tested and obtained using a TOYO 6254 liquid crystal physical property evaluation system; the test voltage: 5 V, 6 Hz, VA type test cell with a cell gap of 9 μm;

[0078] I.sub.on (initial) is tested and obtained using a TOYO 6254 liquid crystal physical property evaluation system under the test conditions: 10 V, 0.01 HZ, 60° C., VA type test cell with a cell gap of 9 μm; I.sub.on (initial) is tested and obtained by placing the VA type test cell at a constant temperature of 150° C. for 1 hour after the I.sub.on (initial) is tested and obtained; and ΔI.sub.on=I.sub.on (high temperature)−I.sub.on (initial).

[0079] The components used in the following Examples can either be synthesized by method known in the art or be obtained commercially. The synthetic techniques are conventional, and each of the obtained liquid crystal compounds is tested to meet the standards of electronic compound.

[0080] The liquid crystal compositions are prepared in accordance with the ratios specified in the following Examples through conventional methods in the art, such as heating, ultrasonic wave, or suspension.

[0081] The liquid crystal compositions of following Examples are prepared and then tested. The components and test results for the performances of the liquid crystal composition of each Example are shown below.

COMPARATIVE EXAMPLE 1

[0082] The liquid crystal composition of Comparative Example 1 is prepared according to each compound and weight percentage listed in Table 2 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00002 TABLE 2 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 79.3 5CCWO2 5 Δn 0.1092 4CCWO2 6 Δε −4 2CCWO2 8 VHR   80% 3PWO2 3.5 γ1 83 3CCV 33.5 V.sub.90 3.871 VCPWO2 11 τ.sub.off 5.16 1PWO2 11 T 26.09% 2PWO2 9 I.sub.on (initial) 4272 VCPWO3 3 I.sub.on (high temperature) 7068 Total 100 ΔI.sub.on 2796

COMPARATIVE EXAMPLE 2

[0083] The liquid crystal composition of Comparative Example 2 is prepared according to each compound and weight percentage listed in Table 3 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00003 TABLE 3 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 80.1 5CCWO2 6 Δn 0.1087 4CCWO2 6 Δε −3.8 2CCWO2 8 VHR   90% 3CWO2 8 γ1 96 3CCV 22 V.sub.90 3.912 1VCPWO2 11 τ.sub.off 5.25 5CWO2 5.5 T 25.89% 2CWO2 10 I.sub.on (initial) 3889 1VCPWO3 3 I.sub.on (high temperature) 5761 3CPP2 5 ΔI.sub.on 1872 5PP1 5.5 Total 100

EXAMPLE 1

[0084] The liquid crystal composition of Example 1 is prepared according to each compound and weight percentage listed in Table 4 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00004 TABLE 4 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 2 Cp 79.8 5CPWO2 6.5 Δn 0.1085 4CCWO2 4.5 Δε −4.1 2CCWO2 6 VHR   92% 3PWO2 7 γ1 104 3CCV 33.5 V.sub.90 4.015 1VCPWO2 6 τ.sub.off 5.34 3CWO2 16.5 T 25.68% 3CPWO2 8 I.sub.on (initial) 3810 4CPWO3 10 I.sub.on (high temperature) 5610 Total 100 ΔI.sub.on 1800

EXAMPLE 2

[0085] The liquid crystal composition of Example 2 is prepared according to each compound and weight percentage listed in Table 5 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00005 TABLE 5 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 79.7 5CCWO2 5 Δn 0.1074 4CCWO2 5 Δε −3.9 2CCWO2 10 VHR   92% 3CWO2 8.5 γ1 101 3CCV 20 V.sub.90 3.952 1VCPWO2 12 τ.sub.off 5.32 1PWO2 7 T 25.74% 3CC2 9 I.sub.on (initial) 3812 1VCCWO3 2 I.sub.on (high temperature) 5550 2PP2V1 4.5 ΔI.sub.on 1738 2VCWO1 6 3CECWO2 1 Total 100

EXAMPLE 3

[0086] The liquid crystal composition of Example 3 is prepared according to each compound and weight percentage listed in Table 6 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00006 TABLE 6 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 79.7 5CCWO2 5 Δn 0.1097 4CCWO2 5 Δε −4 2CCWO2 10 VHR   94% 3CWO2 8.5 γ1 95 3CCV 20 V.sub.90 3.905 1VCPWO2 12 τ.sub.off 5.29 1PWO2 12 T 25.95% 3CC2 9 I.sub.on (initial) 3769 1VCCWO3 2 I.sub.on (high temperature) 5371 2PP2V1 4.5 ΔI.sub.on 1602 2VCWO1 1 2CECWO2 1 Total 100

EXAMPLE 4

[0087] The liquid crystal composition of Example 4 is prepared according to each compound and weight percentage listed in Table 7 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00007 TABLE 7 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 79.7 5CCWO2 6 Δn 0.1097 4CCWO2 6 Δε −4 2CCWO2 8 VHR   94% 3PWO2 5 γ1 90 3CCV 26 V.sub.90 3.899 1VCPWO2 11 τ.sub.off 5.26 1PWO2 11 T 25.98% 2CWO2 6.5 I.sub.on (initial) 3756 1VCPWO3 3 I.sub.on (high temperature) 5271 1PP2V 2.5 ΔI.sub.on 1515 3C2CV1 5 Total 100

EXAMPLE 5

[0088] The liquid crystal composition of Example 5 is prepared according to each compound and weight percentage listed in Table 8 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00008 TABLE 8 Formulation of the liquid crystal composition and the its performances Code of Weight Test results for the performance component percentage parameters 3CWO2 4 Cp 79.8 3CCWO2 9 Δn 0.1092 5CCWO2 5.5 Δε −3.9 2CCWO2 9 VHR   95% 3PWO2 2.5 γ1 87 3CCV 33.5 V.sub.90 3.89 1VCPWO2 10 τ.sub.off 5.23 1VCPWO4 3 T 26.03% 1PWO2 8 I.sub.on (initial) 3706 2PWO2 8.5 I.sub.on (high temperature) 5116 1VCPWO3 4 ΔI.sub.on 1410 1V2PWO3 1 3CC2WO1 1 2C2CWO3 1 Total 100

EXAMPLE 6

[0089] The liquid crystal composition of Example 6 is prepared according to each compound and weight percentage listed in Table 9 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00009 TABLE 9 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 79.7 5CCWO2 5 Δn 0.1011 4CCWO2 6 Δε −4 2CCWO2 8 VHR   95% 3PWO2 3.5 γ1 85 3CCV 33.5 V.sub.90 3.867 1VCPWO2 11 τ.sub.off 5.12 1PWO2 11 T 26.09% 2PWO2 9 I.sub.on (initial) 3701 1VCPWO3 3 I.sub.on (high temperature) 5102 Total 100 ΔI.sub.on 1401

EXAMPLE 7

[0090] The liquid crystal composition of Example 7 is prepared according to each compound and weight percentage listed in Table 10 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00010 TABLE 10 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 10 Cp 80.2 5CCWO2 6 Δn 0.1026 2CCWO2 8 Δε −4 3PWO2 3.5 VHR   96% 3CCV 33.5 γ1 78 1VCPWO2 11 V.sub.90 3.861 1PWO2 11 τ.sub.off 5.01 2PWO2 9 T 26.14% 1VCPWO3 4 I.sub.on (initial) 3662 1VCPWO4 4 I.sub.on (high temperature) 4997 Total 100 ΔI.sub.on 1335

EXAMPLE 8

[0091] The liquid crystal composition of Example 8 is prepared according to each compound and weight percentage listed in Table 11 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00011 TABLE 11 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 9 Cp 82.1 5CCWO2 6.5 Δn 0.1143 2CCWO2 7 Δε −3.9 3PWO2 4.5 VHR   97% 3CCV 34 γ1 72 1VCPWO2 10 V.sub.90 3.858 1VCPWO4 5 τ.sub.off 4.93 1PWO2 9 T 26.18% 2PWO2 8 I.sub.on (initial) 3631 1VCPWO3 5 I.sub.on (high temperature) 4871 2V2PWO2 1 ΔI.sub.on 1240 2C2CWO2 1 Total 100

EXAMPLE 9

[0092] The liquid crystal composition of Example 9 is prepared according to each compound and weight percentage listed in Table 12 and then tested for performance by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00012 TABLE 12 Formulation of the liquid crystal composition and its test performances Code of Weight Test results for the performance component percentage parameters 3CCWO2 9 Cp 79 5CCWO2 4 Δn 0.116 2V1CCWO2 5 Δε −4.1 3PWO2 3.5 VHR   98% 3CCV 34 γ1 66 1VCPWO2 14 V.sub.90 3.856 1VCPWO4 5 τ.sub.off 4.88 1PWO2 9 T 26.23% 2PWO2 9 I.sub.on (initial) 3597 1VCPWO3 5 I.sub.on (high temperature) 4752 1V2PWO2 1.5 ΔI.sub.on 1155 2LWO2 1 Total 100

[0093] Based on the above Examples 1-9, it is indicated that the liquid crystal composition provided herein has an appropriate clearing point, an appropriate optical anisotropy, an appropriate dielectric anisotropy, as well as a higher voltage holding ratio, a higher transmittance, a lower initial ion concentration and a small difference in ion concentration (i.e., a good high-temperature resistant performance). In particular, when the contents of the compounds of general Formula I and general Formula II are increased, the above performance advantages are more obvious, and the rotational viscosity of the liquid crystal composition is also significantly reduced, thereby obtaining a faster response speed. Such liquid crystal compositions are suitable for display modes, such as VA, IPS and FFS.

[0094] Further, it can be seen from the above Comparative Example 1 and Example 6 that the liquid crystal composition of Comparative Example 1 (which comprises compound with similar structure as the compound of general Formula I of the present invention rather than the compound of general Formula I) is significantly inferior to the liquid crystal composition of Example 6 in voltage holding ratio, high-temperature resistant performance, and transmittance. This indicates that the compound of general Formula I of the present invention has an important contribution to the overall performance of the liquid crystal composition.

[0095] Furthermore, as can be seen from the comparison between the above Comparative Example 2 and Examples 1-9, the liquid crystal composition without the compound of general Formula II of the present invention is significantly inferior to the liquid crystal compositions of Examples 1-9 of the present invention in voltage holding ratio, high-temperature resistant performance, and transmittance. This indicates that the compound of general Formula II of the present invention is also essential for maintaining voltage holding ratio, high-temperature resistant performance and transmittance of the liquid crystal composition of the present invention at high levels.

[0096] The above embodiments are merely illustrative of the technical concepts and the features of the present invention, are included merely for purposes of illustration and implement of the present invention, and are not intended to limit the scope of the present invention. Equivalent variations or modifications are intended to be included within the scope of the invention.