Lateral trifluoromethyl-containing liquid crystal compound, liquid crystal mixture and display device

Abstract

Provide are a liquid crystal compound represented by formula I, and a liquid crystal mixture comprising the compound ##STR00001## A lateral trifluoromethyl-containing liquid crystal compound having the structural characteristics of Formula I not only has a negative dielectric anisotropy (Δε), an appropriate optical anisotropy (Δn), a higher clearing point (CP), a prominent low-temperature miscibility with other liquid crystals, and a low rotary viscosity (γ1), but also has a good stability to UV and high temperatures, particularly, a negative dielectric anisotropy. Same can be applied to the formulation of liquid crystal compositions of positive and negative types, and it is particularly prominent that same has the advantages of a good solubility at low temperatures and a high transmittance.

Claims

1. A liquid crystal compound, represented by formula 2-a, 1-b to 1-e, 3-a or 4-a: ##STR00063##

2. A liquid crystal mixture, comprising one or more compounds represented by formula 2-a, 1-b to 1-e, 3-a and 4-a of claim 1, and one or more compounds represented by formula II ##STR00064## wherein R.sub.3 and R.sub.4 each independently represent H, an alkyl group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-6, or an alkoxy group having a carbon atom number of 1-5, wherein any CH.sub.2 therein may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; m represents 1 or 2; and ##STR00065## each independently represent one or more of phenylene, cyclohexylene and/or cyclohexenylene.

3. The liquid crystal mixture according to claim 2, wherein concentrations in mass percentage of said compound represented by formula 2-a, 1-b to 1-e, 3-a and 4-a and said compound represented by formula II are respectively 1-40% and 1-65%.

4. The liquid crystal mixture according to claim 2, wherein said one or more compounds represented by formula II are one or more of compounds represented by formulas II1 to II22 below: ##STR00066## ##STR00067##

5. The liquid crystal mixture according to claim 2, wherein said liquid crystal mixture further comprises one or more of compounds represented by formulas III1 to III14 below: ##STR00068## ##STR00069## wherein each R.sub.5 independently represents H, an alkyl group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-6, or an alkoxy group having a carbon atom number of 1-5, wherein any CH.sub.2 therein may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; (F) represents F or H; and (O) represents O or a single bond.

6. The liquid crystal mixture according to claim 2, wherein said liquid crystal mixture further comprises one or more compounds represented by formula IV: ##STR00070## wherein R.sub.6 represents H, an alkyl group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-6, or an alkoxy group having a carbon atom number of 1-5, wherein any CH.sub.2 therein may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; o represents 0 or 1; each (F) independently represents H or F; and ##STR00071## represents phenylene, cyclohexylene, cyclohexenylene, or a group formed by substituting one or two non-connected CH.sub.2 in cyclohexylene with O.

7. The liquid crystal mixture according to claim 2, wherein the liquid crystal mixture may further comprise one or more negative compounds of formula V, ##STR00072## wherein R.sub.7 and R.sub.8 each independently represent H, an alkyl group having a carbon atom number of 1-5, an alkenyl group having a carbon atom number of 2-6, or an alkoxy group having a carbon atom number of 1-5, wherein any CH.sub.2 therein may be substituted with cyclopentyl, cyclobutyl or cyclopropyl; p and q each independently represent 0, 1 or 2, with 1≤p+q≤3; Z.sub.3 and Z.sub.4 each independently represent a single bond, —CH.sub.2CH.sub.2—, —CH.sub.2O—, —OCH.sub.2— or —CF.sub.2O—; and ##STR00073## each independently represent one or more of ##STR00074##

8. The liquid crystal mixture according to claim 2, wherein said liquid crystal mixture further comprises one or more compounds represented by formula VI: ##STR00075## wherein each P independently represents a polymerizable functional group; each Sp independently represents a spacer group; M represents H, -Sp-P, F, an alkyl group having a carbon atom number of 1-5, an alkoxy group having a carbon atom number of 1-5, or an alkenyl group having a carbon atom number of 2-5; r represents 0, 1 or 2; Z.sub.5 represents a single bond, —COO—, —C≡C—, —C═C— or —CH.sub.2O—; and ##STR00076## each independently represent one or more of a benzene ring, cyclohexane, indane or a naphthalene ring.

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

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The sole FIGURE is a mass spectrum of compound (1-a).

DETAILED DESCRIPTION OF EMBODIMENTS

(2) The present invention is further described in conjunction with particular examples below, but is not limited to these examples below Said methods are all conventional methods, unless otherwise specified. Said raw materials are commercially available, unless otherwise specified.

(3) The specific meanings of symbols in the examples and the test conditions are as follows:

(4) Cp: represents a clearing point of a liquid crystal, with a unit of ° C.

(5) S-N: represents a melting point of a liquid crystal from a crystal state to a nematic phase, with a unit of ° c.

(6) Δn: represents an optical anisotropy, with Δn=n.sub.o−n.sub.e, in which n.sub.o is the refractive index of an ordinary light, and n.sub.e is the refractive index of an extraordinary light, with the test conditions being: 589 nm, 25±0.5° C.

(7) Δε: is a dielectric anisotropy, with Δε=ε//−ε⊥, in which ε// is a dielectric constant parallel to the molecular axis, and ε⊥ is a dielectric constant perpendicular to the molecular axis, with the test conditions being 25±0.50° C., 1 KHz, HP4284A, and 5.2 □m TN left-handed cell.

(8) γ1: is a rotary viscosity, with a unit of mPa.Math.s, with the test conditions being 25±0.5° C.

(9) VHR: is a voltage holding ratio (%), with the test conditions being 20±2° 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.

(10) In the reaction process, the reaction progress is generally monitored by means of TLC, and treatments after the completion of the reaction are generally water washing, extraction, organic phase combination and drying, solvent evaporation under reduced pressure, as well as recrystallization and column chromatography; and a person skilled in the art would be able to implement the present invention according to the following description.

(11) Route 1: Z.sub.2 is —OCF.sub.2—; reference can be made to “Chemical Reagents”, 2015, 37(1), 40-43; 48, “Progress on Synthesis of Liquid Crystalline Compounds Containing Difluoromethyleneoxy-bridged Groups”

(12) ##STR00034##
c: DMF anhydrous potassium carbonate

(13) Route 2: Z.sub.2 is —CF.sub.2O—; reference can be made to “Chemical Reagents”, 2015, 37(1), 40-43; 48, “Progress on Synthesis of Liquid Crystalline Compounds Containing Difluoromethyleneoxy-bridged Groups”

(14) ##STR00035##
d: DMF anhydrous potassium carbonate

(15) Route 3: Z.sub.2 is —CH.sub.2O—;

(16) ##STR00036##

(17) a: DMF K.sub.2CO.sub.3

(18) Route 4: Z.sub.2 is —OCH.sub.2—;

(19) ##STR00037##

(20) b: DMF K.sub.2CO.sub.3

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

(22) TABLE-US-00001 TABLE (I) Corresponding code for ring structure Ring structure Corresponding code C L 0 U P G Gi Y K Ki K(2CH.sub.3) K(2F) Sa 0 Sb Sc

(23) 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— —OCF.sub.2— —Qi— —CH.sub.2O— —O— —OCH.sub.2— —Oi— —F —F —CN —CN —CH.sub.2CH.sub.2— —E— —CH═CH— —V— —C≡C— —W— —COO— —COO— —CH═CH—C.sub.nH.sub.2n+1 Vn— C(5)- C(3)1-

(24) ##STR00054##

Example 1

(25) ##STR00055##

(26) 23.4 g (0.1 mole) of (1-a-1), 35.6.0 g (0.11 mole) of (1-a-2), 200 ml of DMF and 18 g of anhydrous potassium carbonate are charged into a 500 ml three-necked flask, are reacted at 100° C. for 3 hours under stirring, and poured into 1000 nl of water, extraction is carried out using toluene, and the organic phase is washed with water, subjected to evaporation to remove toluene, dissolved in petroleum ether, passes through a silica gel column, and is recrystallized twice by means of toluene+petroleum ether to obtain 19.4 g of product (1-a), with Gc: 99.89%

(27) Δε: −2.1

(28) Δn: 0.081

(29) Δ.sub.⊥: 8.9

(30) γ.sub.1: 43

(31) The sole FIGURE is a mass spectrum of compound (1-a).

(32) With reference to the synthesis method of Example 1, only except that some of the raw materials are replaced, the following compounds can be synthesized

(33) ##STR00056##

Example 2

(34) ##STR00057##

(35) 34.6 g (0.1 mole) of (2-a-1), 23.32.0 g (0.11 mole) of (2-a-2), 200 ml of DMF and 18 g of anhydrous potassium carbonate are charged into a 500 ml three-necked flask, are reacted at 100° C. for 3 hours under stirring, and poured into 1000 nl of water, extraction is carried out using toluene, and the organic phase is washed with water, subjected to evaporation to remove toluene, dissolved in petroleum ether, passes through a silica gel column, and is recrystallized twice by means of toluene+petroleum ether to obtain 20.4 g of product (2-a), with Gc: 99.90%

(36) ##STR00058##

Comparative Compound

(37) ##STR00059##

(38) Δε: −0.9

(39) the dielectric anisotropy is positive.

Example 3

(40) ##STR00060##

(41) 32.8 g (0.1 mole) of (3-a-1), 23.32.0 g (0.11 mole) of (3-a-2), 200 ml of DMF and 18 g of anhydrous potassium carbonate are charged into a 500 ml three-necked flask, are reacted at 80° C. for 5 hours under stirring, and poured into 1000 nl of water, extraction is carried out using petroleum ether, and the organic phase is washed with water, passes through a silica gel column, and is recrystallized 4 times by means of petroleum ether to obtain 27.4 g of product (3-a), with Gc: 99.85%

(42) Δε: −3.3

(43) Δn: 0.08

(44) Δ.sub.⊥: 9.2

(45) γ.sub.1: 80

Example 4

(46) ##STR00061##

(47) 28.2 g (0.1 mole) of (4-a-1), 31.68 g (0.11 mole) of (4-a-2), 200 ml of DMF and 18 g of anhydrous potassium carbonate are charged into a 500 ml three-necked flask, are reacted at 50° C. for 5 hours under stirring, and poured into 1000 nl of water, extraction is carried out using petroleum ether, and the organic phase is washed with water, passes through a silica gel column, and is recrystallized 4 times by means of petroleum ether to obtain 29.4 g of product (4-a), with Gc: 99.88%

(48) Δε: −2.3

(49) Δn: 0.09

(50) Δ.sub.⊥: 8.9

(51) γ.sub.1: 80

Example 5

(52) Liquid Crystal Composition

(53) TABLE-US-00003 Liquid crystal Category monomer code Content (%) I PYQK(2F)-3 10 I PYQiK(2F)-3-O2 10 I PGYQK(2F)-3 10 I APYQK(2F)-2 10 II CC-3-2 30 II CC-3-V 5 II CC-3-V1 5 II CCP-3-1 7 II CPP-3-2 8 II CPP-3-2V1 5 Δε: −1.1 Δn: 0.08 Cp: 50° C. γ.sub.1: 35 mPa .Math. s.

(54) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

Example 6

(55) Liquid Crystal Composition

(56) TABLE-US-00004 Liquid crystal Category monomer code Content (%) I CCQK(2F)-3 10 I PYQiK(2F)-5-O2 10 I PYQKi(3F)-5 8 I CPK(2F)-3 2 II CC-3-2 25 II CC-3-V 5 II CPP-1V-2 5 II CPP-3-2V1 5 V PY-3-O2 5 V CPY-3-O2 5 V CCY-3-O2 5 V CY-3-O4 5 V CCOY-3-O2 5 V COY-3-O2 2 V PYP-C(3)1-2 2 Sb-C(5)O-O4 1 Δε: −2.4 Δn: 0.09 Cp: 75° C. γ.sub.1: 80 mPa .Math. s.

(57) This liquid crystal composition has a moderate Δε, a moderate Δn, a lower γ.sub.1, and a high Cp, and is suitable for use in liquid crystal materials for rapid response TN, IPS, and FFS-TFT displays.

(58) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

(59) Where 10% of the compound of formula I, i.e., PYQiK(2F)-5-O2, is replaced by comparative compound (AA), crystals of compound (AA) are precipitated after the mixture is stored at −20° C. for 100 hours.

(60) A composition formed by adding RM-2 at a concentration in mass percentage of 0.3% of the liquid crystal composition of Example 6 can be applied to PSVA display mode.

Example 7

(61) Liquid Crystal Composition

(62) TABLE-US-00005 Liquid crystal Category monomer code Content (%) I PYQiK(2F)-2-O2 5 I CCOK(2F)-3-O2 5 I PGYQKi(3F)-5 5 I APYQK(2F)-5 5 II CC-3-2 25 II CC-3-V 5 II PP-1-5 5 II CPP-1V-2 5 V CY-3-O2 5 V CPY-3-O2 10 V CCY-3-O2 10 V CPY-C(3)1-O2 5 V CCOY-3-O2 5 Sa-C(5)O-O4 5 Δε: −3.2 Δn: 0.090 Cp: 78° C. γ.sub.1: 55 mPa .Math. s.

(63) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

Example 8

(64) Liquid Crystal Composition

(65) TABLE-US-00006 Liquid crystal Category monomer code Content (%) I PGYQiK(2F)-2 3 I APYQK(2F)-3 3 I PYQK(2F)-5 3 II CC-3-5 10 II PP-1-2V 5 II CPP-3-2 4 II CCP-3-O1 2 V CY-3-O2 10 V CPY-3-O2 15 V CCY-3-O2 10 V CPY-C(5)-O2 10 V CCOY-3-O2 10 V COY-C(5)-O2 10 Sc-C(5)O-O4 5 Δε: −4.4 Δn: 0.10 Cp: 80° C. γ.sub.1: 120 mPa .Math. s.

(66) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

Example 9

(67) Dielectrically Positive Liquid Crystal Composition

(68) TABLE-US-00007 Liquid crystal Category monomer code Content (%) I PYQK(2F)-3 3 I CCOK(2F)-2 2 I PYPQK-3 5 II CC-3-V 30 II CC-2-3 5 II CC-3-V1 5 II PP-2V-1 3 II CCP-3-1 2 II CPP-3-2V1 5 III CCG-3-F 5 III CPU-3-F 5 III CCP-3-OT 5 III PPGI-3-F 5 IV PUQU-C(5)-F 1 IV PUQU-C(3)1-F 1 IV PGUQU-3-F 1 IV PGUQU-C(3)1-F 2 IV PGUQU-C(5)-F 2 IV APUQU-C(5)-F 3 Δε: 6.0 Δn: 0.10 Cp: 60° C. γ.sub.1: 40 mPa .Math. s.

(69) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

Example 10

(70) Dielectrically Positive Liquid Crystal Composition

(71) TABLE-US-00008 Liquid crystal Category monomer code Content (%) I PYQiK(2F)-3 5 I CCOK(2F)-5-O2 5 I PYQK(2F)-3-O2 5 II CC-3-V 30 II CC-5-3 5 II CC-3-V1 5 II CCP-V2-1 5 II CCP-V-1 5 II CPP-1V-2 3 III PGP-C(3)-2 5 III PPGU-C(5)-F 1 III CPUP-3-OT 5 III PGP-3-F 5 IV PUQU-C(5)-F 8 IV PUQU-C(3)1-F 2 IV PGUQU-3-F 1 IV PGUQU-C(3)1-F 2 IV PGUQU-C(5)-F 1 IV CPUQU-C(5)-F 1 IV DUQU-C(5)-F 1 Δε: 4.8 Δn: 0.101 Cp: 75° C. γ.sub.1: 65 mPa .Math. s.

(72) After the mixture is stored at −20° C. for 200 hours, no crystal of the compound of formula I is precipitated.

(73) The liquid crystal compound of formula I has a negative dielectric anisotropy, a good low temperature performance, and a good stability to UV and high temperatures, and has varying Δn, Δε, Cp and γ1 properties depending on R,

(74) ##STR00062##
Z, X, m, n and p, and therefore it has a wider range of applications, and can be used for formulating various positive and negative liquid crystal mixtures with different parameters.