LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY COMPONENT

Abstract

Disclosed are a liquid crystal composition and a liquid crystal display component. The liquid crystal composition comprises one or more compounds as represented by structural formula I-1 and/or one or more compounds as represented by structural formula I-2, one or more compounds as represented by structural formula II, and one or more compounds as represented by structural formula III:

##STR00001##

The liquid crystal display component includes the liquid crystal composition. The liquid crystal composition has a lower viscosity, can achieve a fast response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and a high stability to heat and light. The liquid crystal display component including the liquid crystal composition has the characteristics of a broader nematic phase temperature range, a suitable birefringence anisotropy, a very high electrical resistivity, a good anti-ultraviolet property, a high charge retention ratio, and a fast response.

Claims

1. A liquid crystal composition, characterized in that said liquid crystal composition comprises one or more compounds as represented by structural formula I-1 and/or one or more compounds as represented by structural formula I-2, one or more compounds as represented by structural formula II, and one or more compounds as represented by structural formula III: ##STR00048## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.5 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more non-connected CH.sub.2 in the groups represented by R.sub.1, R.sub.2, R.sub.3 and R.sub.5 may be each independently substituted with cyclopentyl, cyclobutyl, cyclopropyl or oxygen; R.sub.4 represents an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more non-connected CH.sub.2 in the groups represented by R.sub.4 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; Z.sub.1 represents a single bond, CH.sub.2CH.sub.2, CH.sub.2O, or CF.sub.2O; ##STR00049## each independently represent ##STR00050## X.sub.1 represents F, fluoroalkyl, fluoroalkoxy, fluoroalkenyl or fluoroalkenyloxy; X.sub.2, X.sub.3 and X.sub.4 each independently represent H, F, fluoroalkyl, fluoroalkoxy, fluoroalkenyl, fluoroalkenyloxy, or methyl; r represents 0, 1 or 2; and where r represents 1, Z.sub.1 represents a single bond, X.sub.2, X.sub.3 and X.sub.4 all represent H, ##STR00051## X.sub.1 cannot be OCF.sub.3 or CF.sub.3.

2. The liquid crystal composition according to claim 1, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula IV, ##STR00052## wherein R.sub.7 and R.sub.8 represent an alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10 or an alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.7 and R.sub.8 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; ##STR00053## each independently represent ##STR00054## and P represents 1 or 2.

3. The liquid crystal composition according to claim 1, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula V: ##STR00055## wherein R.sub.9 and R.sub.10 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.9 and R.sub.10 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; Z.sub.3 and Z.sub.4 each independently represent a single bond, CH.sub.2CH.sub.2 or CH.sub.2O; ##STR00056## each independently represent ##STR00057## m represents 1 or 2; and n represents 0, 1 or 2.

4. The liquid crystal composition according to claim 1, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula VI: ##STR00058## wherein R.sub.11 and R.sub.12 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.11 and R.sub.12 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; and Lx represents CH.sub.2, CH.sub.2CH.sub.2, O, S, CH.sub.2O, OCH.sub.2, CH.sub.2S, SCH.sub.2 or CF.sub.2.

5. The liquid crystal composition according to claim 1, characterized in that the structural formula of the compounds as represented by structural formula II is specifically one or more selected from formulas II-1 to II-13 below: ##STR00059## wherein R.sub.3 represents an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more non-connected CH.sub.2 in the groups represented by R.sub.3 may be substituted with cyclopentyl, cyclobutyl, cyclopropyl or oxygen; and R.sub.4 represents an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more non-connected CH.sub.2 in the groups represented by R.sub.4 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl.

6. The liquid crystal composition according to claim 1, characterized in that the structural formula of the compounds as represented by structural formula III is specifically one or more selected from formulas III-1 to III-47 below: ##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065## wherein R.sub.5 and R.sub.6 each independently represent an alkyl group having a carbon atom number of 1-5, a fluoro-substituted alkyl group having a carbon atom number of 1-5, an alkoxy group having a carbon atom number of 1-5, a fluoro-substituted alkoxy group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-5, a fluoro-substituted alkenyl group having a carbon atom number of 2-5, an alkenoxy group having a carbon atom number of 3-5 or an fluoro-substituted alkenoxy group having a carbon atom number of 3-5; and (F) represents F or H.

7. The liquid crystal composition according to claim 2, characterized in that the structural formula of the compound as represented by structural formula IV is specifically one selected from formulas IV-1 to IV-6 below: ##STR00066## wherein R.sub.7 and R.sub.8 represent an alkyl group having a carbon atom number of 1-5, an alkoxy group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-5, or an alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.7 and R.sub.8 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl.

8. The liquid crystal composition according to claim 3, characterized in that the structural formula of the compound as represented by structural formula V is specifically one selected from formulas V-1 to V-11 below: ##STR00067## ##STR00068## wherein R.sub.9 and R.sub.10 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.9 and R.sub.10 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl.

9. A liquid crystal display component, characterized in that said liquid crystal display component comprising the liquid crystal composition according to claim 1.

10. The liquid crystal composition according to claim 2, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula V: ##STR00069## wherein R.sub.9 and R.sub.10 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.9 and R.sub.10 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; Z.sub.3 and Z.sub.4 each independently represent a single bond, CH.sub.2CH.sub.2 or CH.sub.2O; ##STR00070## each independently represent ##STR00071## m represents 1 or 2; and n represents 0, 1 or 2.

11. The liquid crystal composition according to claim 2, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula VI: ##STR00072## wherein R.sub.11 and R.sub.12 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.11 and R.sub.12 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; and Lx represents CH.sub.2, CH.sub.2CH.sub.2, O, S, CH.sub.2O, OCH.sub.2, CH.sub.2S, SCH.sub.2 or CF.sub.2.

12. The liquid crystal composition according to claim 3, characterized in that said liquid crystal composition further comprises one or more compounds represented by formula VI: ##STR00073## wherein R.sub.11 and R.sub.12 each independently represent an alkyl group having a carbon atom number of 1-10, a fluoro-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluoro-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluoro-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or a fluoro-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in the groups represented by R.sub.11 and R.sub.12 may be each independently substituted with cyclopentyl, cyclobutyl or cyclopropyl; and Lx represents CH.sub.2, CH.sub.2CH.sub.2, O, S, CH.sub.2O, OCH.sub.2, CH.sub.2S, SCH.sub.2 or CF.sub.2.

Description

DETAILED DESCRIPTION

[0062] In order to more clearly illustrate the present invention, the present invention will be further described below in conjunction with preferred embodiments. A person skilled in the art should understand that the following contents described in detail are illustrative rather than limiting, and should not limit the scope of protection of the present invention.

[0063] In the present invention, preparation methods are all conventional methods unless otherwise specified. The raw materials used are all available from open commercial approaches or prepared according to the prior art, unless otherwise specified, said percentages are all by mass unless otherwise specified, the temperatures are in degrees Celsius ( C.), and the specific meanings of the other symbols and the test conditions are as follows:

[0064] Cp represents the clearing point ( C.) of the liquid crystal measured by a DSC quantitative method;

[0065] SN represents the melting point ( C.) of the liquid crystal from a crystal state to a nematic phase;

[0066] n represents the optical anisotropy, with n=n.sub.en.sub.o, in which n.sub.o is the refractive index of an ordinary light, n.sub.e is the refractive index of an extraordinary light, with the test conditions being: 252 C., 589 nm, and using an abbe refractometer for testing;

[0067] represents the dielectric anisotropy, =e.sub.//.sub., wherein the .sub.// is a dielectric constant parallel to a molecular axis, and .sub. is a dielectric constant perpendicular to the molecular axis, with the test conditions being: 250.5 C., 20-micron parallel cells, and INSTEC: ALCT-IR1 for testing;

[0068] 1 represents a rotary viscosity (mPa.Math.s), with the test conditions being: 250.5 C., 20-micron parallel cells, and INSTEC: ALCT-IR1 for testing; and

[0069] represents an electrical resistivity (.Math.cm), with the test conditions being: 252 C., and the test instruments being a TOYO SR6517 high resistance instrument and an LE-21 liquid electrode.

[0070] VHR represents a voltage holding ratio (%), with the test conditions being: 202 C., a voltage of 5 V, a pulse width of 10 ms, and a voltage holding time of 16.7 ms. The test equipment is a TOYO Model 6254 liquid crystal performance comprehensive tester.

[0071] represents a response time (ms), with the test instrument being DMS-501 and the test conditions being: 250.5 C., a test cell that is a 3.3-micron IPS test cell, an electrode spacing and an electrode width, both of which are 10 microns, and an included angle between the frictional direction and the electrode of 10.

[0072] In the present invention, the equipment and instruments used for preparing the liquid crystal composition are:

[0073] (1) an electronic precision balance (with an accuracy of 0.1 mg)

[0074] (2) stainless steel beaker for weighing a liquid crystal monomer;

[0075] (3) a spoon for adding a liquid crystal monomer;

[0076] (4) a magnetic rotor for stirring; and

[0077] (5) a temperature-controlled electromagnetic stirrer.

[0078] A method for preparing a liquid crystal composition comprises the following steps:

[0079] (1) monomers to be used are placed in order neatly;

[0080] (2) a stainless steel beaker is placed on the balance, and the liquid crystal monomers are placed into the stainless steel beaker with small spoons;

[0081] (3) the monomer liquid crystals are added in order by weights as required;

[0082] (4) the stainless steel beaker, to which the materials have been added, is placed on a magnetic stirring instrument for heating and melting; and

[0083] (5) after the mixture in the stainless steel beaker is mostly melted, a magnetic rotor is added to the stainless steel beaker for uniformly stirring the liquid crystal mixture, and after cooling to room temperature, the liquid crystal composition is obtained.

[0084] In the embodiments of the present invention, liquid crystal monomer structures are represented by codes, wherein the codes of ring structures, end groups and linking groups of liquid crystals are represented, as shown in tables 1 and 2 below.

TABLE-US-00001 TABLE 1 Corresponding code for ring structure Ring structure Corresponding code [00025] C [00026] P [00027] L [00028] G [00029] Gi [00030] Y [00031] K [00032] U [00033] A [00034] D [00035] Di [00036] Ida [00037] Sa [00038] Sb [00039] Sc [00040] Sd

TABLE-US-00002 TABLE 2 Corresponding code for end group and linking group End group and linking group Corresponding code C.sub.nH.sub.2n+1 n- C.sub.nH.sub.2n+1O nO OCF.sub.3 OT CF.sub.3 T CF.sub.2O Q CH.sub.2O O F F CN CN CH.sub.2CH.sub.2 E CHCH V COO Z CHCHC.sub.nH.sub.2n+1 Vn [00041] Cp [00042] Cb [00043] Cpr [00044] Cpr1

EXAMPLES

[0085] ##STR00045##

the code of which is CC-Cp-V1; and

##STR00046##

the code of which is PGP-Cpr1-2.

[0086] The following specific embodiments are used to illustrate the present invention:

Example 1

[0087] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 3 below.

TABLE-US-00003 TABLE 3 Formula of the liquid crystal composition of Example 1 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 30 II CC-3-V 20 I-2 PGP-3-T 2 I-1 PGP-3-OT 3 III PPGi-5-F 13 III PUQU-Cp-F 17 III PGUQU-Cp-F 6 III PPGU-Cp-F 1 III CPGU-Cp-F 3 III CPUP-3-OT 5 Performance [1 KHz, 20 C.]: 7.7; parameter .sub. [1 KHz, 20 C.]: 3.4 n [589 nm; 20 C.]: 0.12; Cp: 62 C.; .sub.1: 52 mPa .Math. s.

[0088] Conclusion: the liquid crystal composition of Example 1 has a lower viscosity, can achieve a fast response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and high stability to heat and light.

Example 2

[0089] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 4 below.

TABLE-US-00004 TABLE 4 Formula of the liquid crystal composition of Example 2 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 25 II CC-3-V 20 I-1 PGP-3-OT 2 I-1 PGP-Cpr1-OT 3 III PPGi-5-F 13 III PUQU-Cp-F 17 III PGUQU-Cp-F 11 III PPGU-Cp-F 1 III CPGU-Cp-F 3 III CPUP-3-OT 5 Performance [1 KHz, 20 C.]: 9.2; parameter .sub. [1 KHz, 20 C.]: 3.5 n [589 nm, 20 C.]: 0.12; Cp: 65 C.; .sub.1: 61 mPa .Math. s.

[0090] Conclusion: the liquid crystal composition of Example 2 has a lower viscosity, can achieve a fast response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and high stability to heat and light.

Example 3

[0091] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 5 below.

TABLE-US-00005 TABLE 5 Formula of the liquid crystal composition of Example 3 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 25 II CC-3-V 20 I-2 PGP-3-T 8 I-2 PGP-Cpr1-T 12 III PPGi-5-F 10 III PUQU-Cp-F 10 III PGUQU-Cp-F 6 III PPGU-Cp-F 1 III CPGU-Cp-F 3 III CPUP-3-OT 5 Performance [1 KHz, 20 C.]: 8.4; parameter .sub. [1 KHz, 20 C.]: 3.4 n [589 nm, 20 C.]: 0.13; Cp: 65 C.; .sub.1: 55 mPa .Math. s.

[0092] Conclusion: the liquid crystal composition of Example 3 has a lower viscosity, can achieve a fast response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and high stability to heat and light.

Example 4

[0093] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 6 below.

TABLE-US-00006 TABLE 6 Formula of the liquid crystal composition of Example 4 and the corresponding properties thereof Content Classification Liquid crystal monomer code (%) II CC-3-V 10 I-1 PGP-3-OT 6 I-2 PGP-2-T 6 II PP-1-5 6 II CP-3-O2 4 IV CCP-3-2 11 III CCU-2-F 12 III CCP-2-OT 8 III PUQU-Cp-F 17 III APUQU-Cp-F 6 III CCPG-3-F 5 IV CPP-2-3 9 Performance [1 KHz, 20 C.]: 9.2; parameter .sub. [1 KHz, 20 C.]: 3.6 n [589 nm, 20 C.]: 0.13; Cp: 83 C.; .sub.1: 84 mPa .Math. s.

Comparative Example 1

[0094] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 7 below.

TABLE-US-00007 TABLE 7 Formula of the liquid crystal composition of Comparative Example 1 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-V 10 IV PGP-3-5 6 IV PGP-2-3 6 II PP-1-5 6 II CP-3-O2 4 IV CCP-3-2 11 III CCU-2-F 12 III CCP-2-OT 8 III PUQU-Cp-F 17 III APUQU-Cp-F 6 III CCPG-3-F 5 IV CPP-2-3 9 Performance [1 KHz, 20 C.]: 7.8; parameter .sub. [1 KHz, 20 C.]: 3.5 n [589 nm, 20 C.]: 0.13; Cp: 80 C.; .sub.1: 95 MPa .Math. s.

[0095] Conclusion: in contrast to Example 4, Comparative Example 1 relates to compounds of formulas IV with the structural formulas PGP-3-5 and PGP-2-3 instead of the compounds of structural formulas I-1 and I-2. Example 4 has a lower rotary viscosity .sub.1, a higher clearing point Cp, and a higher dielectric anisotropy , indicating that although the compounds of structural formulas PGP-3-5 and PGP-2-3 have a similar structure to the compounds of formulas I-1 and I-2, the compounds of formulas I-1 and I-2 have a lower rotary viscosity, a higher clearing point, and a higher dielectric anisotropy, such that Example 4 involving the compounds of formulas I-1 and I-2 has a lower drive voltage, a wider service temperature range, and a faster response speed.

Example 5

[0096] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 8 below.

TABLE-US-00008 TABLE 8 Formula of the liquid crystal composition of Example 5 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 23 II CC-3-V1 12 I-1 PGP-Cp-OT 8 I-2 PGP-4-T 7 III CCU-2-F 9 III CPU-3-F 8 IV CCP-V2-1 10 III PGUQU-Cpr1-F 17 III PGUQU-4-F 6 Performance [1 KHz, 20 C.]: 9.9; parameter .sub. [1 KHz, 20 C.]: 3.4 n [589 nm, 20 C.]: 0.12; Cp: 77 C.; .sub.1: 88 mPa .Math. s.

Comparative Example 2

[0097] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 9 below.

TABLE-US-00009 TABLE 9 Formula of the liquid crystal composition of Comparative Example 2 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 23 II CC-3-V1 12 III PGP-5-F 8 III PGP-4-F 7 III CCU-2-F 9 III CPU-3-F 8 IV CCP-V2-1 10 III PGUQU-Cpr1-F 17 III PGUQU-4-F 6 Performance [1 KHz, 20 C.]: 8.9; parameter .sub. [1 KHz, 20 C.]: 3.4 n [589 nm, 20 C.]: 0.12; Cp: 82 C.; .sub.1: 94 mPa .Math. s.

[0098] Conclusion: in contrast to Example 5, Comparative Example 2 relates to compounds of formulas III with the structural formulas PGP-4-F and PGP-5-F instead of the compounds of structural formulas I and I-2. Example 5 has a lower rotary viscosity .sub.1 and a higher dielectric anisotropy ; in addition, Comparative Example 2 shows crystallization after storage for 100 hours in an environment of 0 C., whereas Example 5 does not show crystallization under the same conditions. This indicates that although the compounds of structural formulas PGP-4-F and PGP-5-F have a similar structure to the compounds of formulas I-1 and I-2, the compounds of formulas I-1 and I-2 have a lower rotary viscosity and a higher dielectric anisotropy; furthermore, cyclopentyl-substituted compounds of formula I-1 have a better intersolubility. Therefore, Example 5 comprising the compounds of formulas I-1 and I-2 have a lower drive voltage, a faster response speed, and a better low-temperature intersolubility.

Example 6

[0099] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 10 below.

TABLE-US-00010 TABLE 10 Formula of the liquid crystal composition of Example 6 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 20 II CC-3-V 18 II CP-3-O2 2 I-1 PGP-V2-OT 5 I-1 PGP-Cpr1-OT 5 III CCG-2-F 12 III CCP-2-OT 8 III PUQU-Cpr1-F 17 III PGUQU-3-F 8 IV CPPC-3-3 5 Performance [1 KHz, 20 C.]: 7.9 parameter .sub. [1 KHz, 20 C.]: 3.6 n [589 nm, 20 C.]: 0.099; Cp: 64 C.; .sub.1: 54 mPa .Math. s.

Comparative Example 3

[0100] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 11 below.

TABLE-US-00011 TABLE 11 Formula of the liquid crystal composition of Comparative Example 3 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 20 II CC-3-V 18 II CP-3-O2 2 III PGU-V2-F 5 III PGU-4-F 5 III CCG-2-F 12 III CCP-2-OT 8 III PUQU-Cpr1-F 17 III PGUQU-3-F 8 IV CPPC-3-3 5 Performance [1 KHz, 20 C.]: 8.0; parameter .sub. [1 KHz, 20 C.]: 3.7 n [589 nm, 20 C.]: 0.098; Cp: 60 C.; .sub.1: 58 mPa .Math. s.

[0101] Conclusion: in contrast to Example 6, Comparative Example 3 relates to compounds of formulas III with the structural formulas PGU-V2-F and PGU-4-F instead of the compound of structural formula I-1. Example 6 is comparable to Comparative Example 3 in terms of dielectric anisotropy, but has a higher optical anisotropy n, a higher clearing point Cp, and a lower rotary viscosity .sub.1. The response speed of the liquid crystal display device is related to the thickness of the cell, and the smaller the thickness of the cell, the faster the response speed. Therefore, reducing the cell thickness of a liquid crystal display device is one of the methods for improving response speed. On the basis of the same delay amount design, for reducing the cell thickness of the liquid crystal display device, it is necessarily required to increase the optical anisotropy of the liquid crystal composition, so that Example 6 which has a higher optical anisotropy n is more suitable for the low cell thickness requirements of current fast response liquid crystal display devices.

Example 7

[0102] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 12 below.

TABLE-US-00012 TABLE 12 Formula of the liquid crystal composition of Example 7 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 5 II CC-3-V 45 I-1 PGPCpOT 5 I-2 PGPCprT 5 III PPGi-5-F 8 III PUQUCpF 10 III PGUQU-5-F 6 III PPGUCpF 1 V CPY-3-O2 10 III CPUP-3-T 5 Additive [00047] 0.03 Performance [1 KHz, 20 C.]: 6.0 parameter .sub. [1 KHz, 20 C.]: 3.9 n [589 nm, 20 C.]: 0.12 Cp: 70 C. .sub.1: 59 mPas

[0103] Conclusion: The content of the additive in Example 7 is obtained by means of calculation based on the total content of the compounds as represented by formulas V, II, and V in the liquid crystal composition of Example 7 being 100%. Since the compound as represented by formula V has a larger vertical dielectric constant with respect to formula III, by adding a compound of formula V to the liquid crystal composition, the vertical dielectric constant of the liquid crystal composition can be increased, thereby improving the transmittance of the liquid crystal composition. Furthermore, by means of an antioxidant additive, the stability of the liquid crystal composition is improved.

Example 8

[0104] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 13 below.

TABLE-US-00013 TABLE 13 Formula of the liquid crystal composition of Example 8 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 20 II CC-3-V 18 II CP-3-O2 2 I-1 PGP-Cp-OT 5 I-1 PGP-3-OT 5 III CCU-3-F 8 III CGU-2-F 12 III PGU-2-F 10 III PUQU-Cpr1-F 10 III PGUQU-Cpr1-F 3 VI Sb-Cp1O-O5 2 VI Sc-Cpr1O-O5 3 VI Sb-Cpr1O-O5 2 Performance [1 KHz, 20 C.]: 7.5; parameter .sub. [1 KHz, 20 C.]: 4.8 n [589 nm, 20 C.]: 0.11; Cp: 42 C.; .sub.1: 46 mPa .Math. s.

[0105] Conclusion: the compound represented by formula VI, with respect to the compound represented by formula V, has a larger vertical dielectric constant, and can further improve the transmittance of the liquid crystal composition; however, the rotary viscosity thereof is also larger than that of the compound of formula V; if same is used too much, the response speed of the liquid crystal composition may be reduced.

Example 9

[0106] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 14 below.

TABLE-US-00014 TABLE 14 Formula of the liquid crystal composition of Example 9 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 10 I-1 PGP-1V2-OT 6 I-2 PGP-V2-T 6 II PP-1-5 8 II CP-3-O2 6 IV CCG-3-2 11 III CPU-3-F 8 III CPU-2-F 12 III DCU-3-F 10 V CY-3-O2 10 V CCY-4-O2 5 III PUQU-Cpr1-F 5 III PGUQU-Cpr1-F 3 Performance [1 KHz, 20 C.]: 8.0; parameter .sub. [1 KHz, 20 C.]: 5.0 n [589 nm, 20 C.]: 0.13; Cp: 58 C.; .sub.1: 87 mPa .Math. s.

Example 10

[0107] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 15 below.

TABLE-US-00015 TABLE 15 Formula of the liquid crystal composition of Example 10 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 23 II CC-3-V1 12 I-2 PGP-3Cp-T 7 I-2 PGP-Cpr1-T 8 IV CPP-2-2 9 IV CPP-3-2 5 III PUQK-5-F 9 III PGUQK-3-F- 5 III PUQU-Cpr1-F 10 III PGUQU-Cpr1-F 7 VI Sb-Cp1O-O5 3 VI Sc-Cpr1O-O5 2 Performance [1 KHz, 20 C.]: 9.0; parameter .sub. [1 KHz, 20 C.]: 4.5 n [589 nm, 20 C.]: 0.13; Cp: 63 C.; .sub.1: 72 mPa .Math. s.

Example 11

[0108] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 16 below.

TABLE-US-00016 TABLE 16 Formula of the liquid crystal composition of Example 11 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 20 II CC-3-V 20 I-1 PGP-3-OT 2 I-1 PGP-5-OT 3 III IdaUQU-3-F 8 III IdaGUQU-5-F 10 III PGP-3-F 8 III PGP-5-F 7 V CY-3-O2 5 V PY-3-O2 5 V COY-3-O1 5 V CCOY-3-O2 5 VI Sb-Cp1O-O5 2 Performance [1 KHz, 20 C.]: 4.5; parameter .sub. [1 KHz, 20 C.]: 5.6 n [589 nm, 20 C.]: 0.12; Cp: 61 C.; .sub.1: 64 mPa .Math. s.

Example 12

[0109] The formula of the liquid crystal composition and the corresponding properties thereof are as shown in table 17 below.

TABLE-US-00017 TABLE 17 Formula of the liquid crystal composition of Example 12 and the corresponding properties thereof Classification Liquid crystal monomer code Content (%) II CC-3-2 20 II CC-3-V 20 I-1 PGP-Cpr1-OT 3 I-2 PGP-Cpr1-T 2 III PUQK-5-F 4 III PGUQK-3-F 4 III DUQK-5-F 4 III CPUQK-3-F 4 III APUQK-3-F 4 III PUQU-Cp-F 4 III PUQU-Cpr1-F 4 III PGUQU-Cp-F 4 III PGUQU-Cpr1-F 4 III PPGU-3-F 2 IV CCP-V2-1 6 IV CCP-V-1 4 V CPY-3-O2 3 V PY-3-02 2 VI Sb-Cp1O-O5 Performance [1 KHz, 20 C.]: 9.6; parameter .sub. [1 KHz, 20 C.]: 4.5 n [589 nm, 20 C.]: 0.11; Cp: 64 C.; .sub.1: 67 mPa .Math. s.

[0110] Conclusion: As can be seen from the above examples, the liquid crystal compositions provided by the examples of the present invention have a lower rotary viscosity .sub.1, is used for liquid crystal display, can achieve a fast response, and further has a moderate dielectric anisotropy , a moderate optical anisotropy n, and a high stability to heat. They are especially suitable for liquid crystal materials for TN, IPS, and VA modes.

[0111] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the embodiments of the present invention; for a person of ordinary skill in the art, on the basis of the above description, other variations or changes in different forms may also be made, all the embodiments cannot be provided exhaustively herein, and any obvious variation or change derived from the technical solution of the present invention is still within the scope of protection of the present invention.