Liquid crystal compound and liquid crystal composition

Abstract

Provided is a liquid crystal compound represented by formula I, ##STR00001##
the compound having a positive dielectric anisotropy, a great elastic constant and a good solubility. Further provided is a liquid crystal composition comprising the liquid crystal compound represented by formula I, the liquid crystal composition having a good stability against light and heat, a lower viscosity, a wider refractive index that may be achieved by the adjustment of the monomer ratio, and a higher clearing point (a very wide service temperature range), and in particular, the liquid crystal composition has a higher light transmittance, thus allowing a display device to have a higher brightness or an energy saving effect.

Claims

1. A liquid crystal compound represented by formula I, ##STR00044## wherein R.sub.1 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, and any one or more non-connected CH.sub.2 in the groups represented by R.sub.1 may be substituted with cyclopentyl, cyclobutyl, cyclopropyl or O; each ##STR00045## independently represents ##STR00046## or fluorobenzene; where n represents 2 or 3, not every ##STR00047## represents ##STR00048## Z.sub.0 represents CF.sub.2O, CH.sub.2O, COO or a single bond; and, the dielectric anisotropy of the liquid crystal compound is positive.

2. The liquid crystal compound according to claim 1, wherein the liquid crystal compound represented by formula I is a compound represented by formulas I1 to I24; ##STR00049## ##STR00050## ##STR00051## wherein each R.sub.11 independently represents an alkyl group having a carbon atom number of 1-6, cyclopentyl or cyclopropylmethyl; and each (F) independently represents F or H.

3. A liquid crystal composition, wherein said liquid crystal composition comprises one or more compounds represented by formula I of claim 1 and one or more compounds represented by formula II ##STR00052## wherein R.sub.2 and R.sub.3 each independently represent an alkyl group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, an alkoxy group having a carbon atom number of 1-10, and any one or more non-connected CH.sub.2 in groups R.sub.2 and R.sub.3 may be substituted with cyclopentyl, cyclobutyl, cyclopropyl, or O; ##STR00053## each independently represent ##STR00054## and m represents 1 or 2.

4. The liquid crystal composition according to claim 3, wherein said compound represented by formula II is a compound represented by formulas II1 to II17 ##STR00055## ##STR00056## wherein R.sub.2 and R.sub.3 each independently represents an alkyl group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, an alkoxy group having a carbon atom number of 1-10, and any one or more non-connected CH.sub.2 in groups R.sub.2 and R.sub.3 may be substituted with cyclopentyl, cyclobutyl, cyclopropyl, or O.

5. The liquid crystal composition according to claim 3, wherein in said liquid crystal composition, the total content in mass percentage of the compounds represented by formula I is 1-40%, and the total content in mass percentage of the compounds represented by formula II is 5-65%.

6. The liquid crystal composition according to claim 3, wherein said liquid crystal composition further comprises one or more compounds represented by formula III ##STR00057## wherein 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 an fluoro-substituted alkenoxy group having a carbon atom number of 3-8; and any one or more CH.sub.2 in group R.sub.4 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; ##STR00058## each independently represents: ##STR00059## p represents 1, 2 or 3; Z.sub.1 and Z.sub.2 each independently represent a single bond, CF.sub.2O, CH.sub.2CH.sub.2, or CH.sub.2O; and Y.sub.2 represents F, a fluoro-substituted alkyl group having a carbon atom number of 1-5, a fluoro-substituted alkoxy group having a carbon atom number of 1-5, or an alkenyl group having a carbon atom number of 2-5.

7. The liquid crystal composition according to claim 6, wherein said one or more compounds represented by formula III are compounds of formulas III1 to III22 ##STR00060## ##STR00061## ##STR00062## wherein X.sub.1 and X.sub.2 each independently represent H or F; wherein each R.sub.4 independently 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, and any CH.sub.2 in group of R.sub.4 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; (F) represents H or F; and Y.sub.2 represents F, a fluoro-substituted alkyl group having a carbon atom number of 1-5, a fluoro-substituted alkoxy group having a carbon atom number of 1-5, or an alkenyl group having a carbon atom number of 2-5.

8. The liquid crystal composition according to claim 3, wherein said liquid crystal composition further comprises one or more compounds represented by formula IV ##STR00063## wherein R.sub.5 and R.sub.6 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, and any CH.sub.2 in groups R.sub.5 and R.sub.6 may be 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; ##STR00064## each independently represent ##STR00065## h represents 1, 2 or 3; and i represents 0 or 1.

9. The liquid crystal composition according to claim 8, wherein the compound represented by formula IV is a compound represented by formulas IV1 to IV11 ##STR00066## ##STR00067## wherein R.sub.5 and R.sub.6 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, and any CH.sub.2 in groups R.sub.5 and R.sub.6 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl.

10. A liquid crystal display element or liquid crystal display comprising the liquid crystal compound of claim 1, wherein said liquid crystal display element or liquid crystal display is an active matrix display element or display or a passive matrix display element or display.

Description

DETAILED DESCRIPTION OF THE DRAWINGS

(1) The present invention is further described as below in combination with particular embodiments, but the present invention is not limited to the following embodiments. Said methods are all conventional methods, unless otherwise specified. Said raw materials, unless otherwise specified, are commercially available.

(2) The reaction process is generally monitored through TLC, and the post-treatments after the reaction is completed are generally water washing, extracting, combining organic phases and then drying, evaporating and removing the solvent under a reduced pressure, recrystallization and column chromatographic separation; and a person skilled in the art would be able to achieve the present invention according to the following description.

(3) In the present specification, the percentages are mass percentages, the temperatures are in degree Celsius ( C.), and the specific meanings of other symbols and the test conditions are as follows:

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

(5) n represents the optical anisotropy, n.sub.o is the refractive index of an ordinary light, n.sub.e is the refractive index of an extraordinary light, the test condition is 252 C. and 589 nm, and an abbe refractometer is used for the test;

(6) represents the dielectric anisotropy, =.sub.//.sub., wherein .sub.// is a dielectric constant parallel to a molecular axis, and .sub. is a dielectric constant perpendicular to the molecular axis, the test condition is 250.5 C., a 20 micron parallel cell is used, and INSTEC: ALCT-IR1 is used for the test;

(7) 1 represents a rotary viscosity (mPa.Math.s), the test condition is 250.5 C., a 20 micron parallel cell is used, and INSTEC: ALCT-IR1 is used for the test; and

(8) T (%) represents a transmittance, T (%)=100%*bright state (Vop) luminance/light source luminance, the test device is DMS501, the test condition is 250.5 C., the test cell is a 3.3 micron IPS test cell, both the electrode spacing and the electrode width are 10 microns, and the included angle between the frictional direction and the electrode is 10; therefore, there is a positive correlation between a .sub. and T, so in the evaluation of the transmittance, .sub. can be used as an evaluation index for indication.

(9) In the examples of the present invention application, liquid crystal monomer structures are represented by codes, wherein the code representation of cyclic structures, end groups and linking groups of the liquid crystals are shown in tables (I) and (II) below

(10) TABLE-US-00001 TABLE (I) Corresponding code for ring structure Corresponding Cyclic structure code C P G 0 U Gi Y A D

(11) TABLE-US-00002 TABLE (II) Corresponding code for end group and linking group End groups and linking groups Corresponding code C.sub.nH.sub.2n+1 n C.sub.nH.sub.2n+1O nO OCF.sub.3 OT CF.sub.2O Q F F CH.sub.2CH.sub.2 E CHCH V CH.sub.2O O CHCHC.sub.nH.sub.2n+1 Vn C(5) C(3)1 O5FA
For example:

(12) ##STR00038##

Example 1

(13) ##STR00039##

(14) To a 250 ml three-necked flask, 4.26 g of (1-A), 30 ml of DMF and 0.6 g of sodium hydroxide are added, and reacted with stirring at room temperature for 20 minutes, a solution of 2.82 g of 1,1,2,3,3-pentafluoro-3-iodopropene in 10 ml of DMF is dropwise added at room temperature, and a reaction is carried out for 12 hours.

(15) 100 ml of water is added, the aqueous phase is extracted with petroleum ether, the organic phase is washed with water and passes through a silica gel column, and the chromatographic solution is concentrated to 10 ml and crystallises at a low temperature to obtain 3.33 g of a white crystal (1-B) with a yield of 60% and a GC of 99.92%.

(16) [1 KHz, 20 C.]: 11

(17) .sub.: 8.7

(18) n [589 nm, 20 C.]: 0.144

(19) Cp: 55 C.

(20) ##STR00040##

(21) [1 KHz, 20 C.]: 13

(22) .sub.: 8.0

(23) n [589 nm, 20 C.]: 0.200

(24) Cp: 114 C.

(25) Comparative parameters

(26) ##STR00041##

(27) [1 KHz, 20 C.]: 22

(28) .sub.: 5.0

(29) n [589 nm, 20 C.]: 0.198

(30) Cp: 114 C.

(31) The .sub. of the comparative compound is significantly reduced

(32) ##STR00042##

(33) [1 KHz, 20 C.]: 4.0

(34) .sub.: 5.5

(35) n [589 nm, 20 C.]: 0.220

(36) Cp: 135 C.

(37) Comparative parameters:

(38) ##STR00043##

(39) [1 KHz, 20 C.]: 4.4

(40) .sub.: 5.5

(41) n [589 nm, 20 C.]: 0.220

(42) Cp: 105 C.

(43) The CP of the comparative compound is significantly reduced

Example 2

(44) TABLE-US-00003 Classification Liquid crystal monomer code Content (%) II CC-3-V 50 II CCP-V-1 10 II CCP-V2-1 8 I PUQY-3-O5FA 9 I PGUQY-3-O5FA 6 I CCQY-5-O5FA 7 I CPY-5-O5FA 2 I AGUQY-3-O5FA 8 [1 KHz, 20 C.]: 4.3 .sub.: 4.2 n [589 nm, 20 C.]: 0.098 Cp: 95 C. .sub.1: 56 mPa .Math. s.

Comparative Example 1

(45) TABLE-US-00004 Classification Liquid crystal monomer code Content (%) II CC-3-V 50 II CCP-V-1 10 II CCP-V2-1 8 PUQU-3-O5FA 9 PGUQU-3-O5FA 6 CCQU-5-O5FA 7 CPU-5-O5FA 2 AGUQU-3-O5FA 8 [1 KHz, 20 C.]: 5.8 : 3.2 n [589 nm, 20 C.]: 0.090 Cp: 85 C. .sub.1: 55 mPa .Math. s.

(46) The of the comparative example is remarkably reduced, and the transmittance thereof is reduced by 4%.

Example 3

(47) TABLE-US-00005 Classification Liquid crystal monomer code Content (%) II CC-3-V 33 II BCH-3-2 4 I PUQY-3-O5FA 3 I PGUQY-3-O5FA 6 I APUQY-3-O5FA 6 III CCP-3-OT 14 III PUQU-C(5)-F 6 III PGUQU-C(3)-F 7 III PGP-C(3)1-2 10 III CPUP-3-OT 5 III PPGU-C(5)-F 1 IV CPY-3-O2 5 [1 KHz, 20 C.]: 5.2 : 3.9 n [589 nm, 20 C.]: 0.108 Cp: 76 C. .sub.1: 89 mPa .Math. s.

Example 4

(48) TABLE-US-00006 Classification Liquid crystal monomer code Content (%) II CC-3-V 33 II CCP-V-1 7 I PUQY-3-O5FA 3 I PGUQY-3-O5FA 6 I CPUQY-3-O5FA 6 III CCP-3-OT 14 III PUQU-C(5)-F 6 III PGUQU-C(5)-F 7 III PGP-C(3)1-2 5 III PPGi-3-F 5 III CPUP-3-OT 4 III PPGU-C(5)-F 1 IV CCY-3-O2 3 [1 KHz, 20 C.]: 5.2 : 3.7 n [589 nm, 20 C.]: 0.109 Cp: 79 C. .sub.1: 81 mPa .Math. s.

Example 5

(49) TABLE-US-00007 Classification Liquid crystal monomer code Content (%) II CC-3-V 40 II CC-3-V1 5 I PUQY-3-O5FA 11 I PGUQY-3-O5FA 6 I APUQY-3-O5FA 6 III CCU-3-F 11 III PUQU-C(5)-F 6 III APUQU-C(5)-F 4 III CPUQU-C(5)-F 1 III CCPU-3-F 4 III DUQU-C(5)-F 1 IV CPY-3-O2 5 [1 KHz, 20 C.]: 7.5 : 4.2 n [589 nm, 20 C.]: 0.100 Cp: 77 C. .sub.1: 91 mPa .Math. s.

Example 6

(50) TABLE-US-00008 Classification Liquid crystal monomer code Content (%) II CC-3-V 30 II CP-3O2 2 I PUQY-3-O5FA 3 I PGUQY-3-O5FA 6 I DGUQY-3-O5FA 6 III CPP-3-F 14 III PUQU-C(5)-F 6 III PGUQU-C(3)-F 7 III PGP-3-F 10 III CCGU-3-F 5 III PPGU-C(5)-F 1 IV CPY-3-O2 5 [1 KHz, 20 C.]: 8.8 : 3.9 n [589 nm, 20 C.]: 0.108 Cp: 76 C. .sub.1: 85 mPa .Math. s.

(51) The present invention is very suitable for displays of positive IPS and FFS modes. The liquid crystal composition of the present invention has a good stability against light and heat, a lower viscosity, a wider refractive index that may be achieved by adjustment, and a higher clearing point (a very wide service temperature range), and in particular, the liquid crystal composition has a higher light transmittance, thus allowing a display device to have a higher brightness or an energy saving effect.