Liquid crystal compound and liquid crystal composition

Abstract

A compound represented by formula I, a negative liquid crystal composition comprising such a compound, and a liquid crystal display element or liquid crystal display comprising the compound or liquid crystal composition are provided. The compound represented by formula I contains two hydroxy groups. In an ODF process for a panel, due to an intermolecular force between the hydroxyl groups and the surface of the panel (a glass surface or an ITO electrode surface), the compound is spontaneously aligned, in a standing manner, on the panel glass or transparent ITO electrode substrate, causing liquid crystal molecules similar to the compound represented by formula ITO be vertically aligned, and UV light irradiation, a polymer layer with a rough surface is formed on the substrate by means of polymerization, and achieves the effects of PI insulation and vertical alignment of the liquid crystal molecules.

Claims

1. A liquid crystal composition, comprising one or more compounds represented by formula I-1 to I-34; one or more compounds represented by formula II-1 to II-14; and one or more compounds represented by formula III-1 to III-11: ##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067## ##STR00068## ##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## wherein R.sub.3 and R.sub.4 each independently represent an alkyl group having a carbon atom number of 1-10, a fluorine-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluorine-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluorine-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or an fluorine-substituted alkenoxy group having a carbon atom number of 3-8, wherein any one or more CH.sub.2 in R.sub.3 and R.sub.4 may be substituted with cyclopentyl, cyclobutyl or cyclopropyl.

2. The liquid crystal composition according to claim 1, wherein said liquid crystal composition is a negative liquid crystal composition, and further comprises one or more compounds represented by formula IV: ##STR00078## wherein R.sub.5 and R.sub.6 each independently represent an alkyl group having a carbon atom number of 1-10, a fluorine-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluorine-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluorine-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or an fluorine-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.5 and R.sub.6 may be replaced by cyclopentyl, cyclobutyl or cyclopropyl; and W represents O, S or —CH2O—.

3. The liquid crystal composition according to claim 1, wherein said liquid crystal composition further comprises one or more compounds represented by formula V: ##STR00079## wherein R.sub.7 and R.sub.8 each independently represent an alkyl group having a carbon atom number of 1-10, a fluorine-substituted alkyl group having a carbon atom number of 1-10, an alkoxy group having a carbon atom number of 1-10, a fluorine-substituted alkoxy group having a carbon atom number of 1-10, an alkenyl group having a carbon atom number of 2-10, a fluorine-substituted alkenyl group having a carbon atom number of 2-10, an alkenoxy group having a carbon atom number of 3-8 or an fluorine-substituted alkenoxy group having a carbon atom number of 3-8: ##STR00080## each independently represent 1,4-phenylene, 1,4-cyclohexylene, or 1,4-cyclohexenylene.

4. The liquid crystal composition according to claim 1, wherein said liquid crystal composition further comprises one or more polymerizable compounds represented by formula VI: ##STR00081## wherein ##STR00082## each independently represent phenylene, fluorinated phenylene, or indanyl; and P.sub.1, P.sub.2, and P.sub.3 each independently represent a methacrylate group or an acrylate group.

5. A liquid crystal display element or liquid crystal display comprising the liquid crystal compound or liquid crystal composition of claim 1, said display element or display being an active matrix display element or display or a passive matrix display element or display.

6. The liquid crystal display element or liquid crystal display according to claim 5, wherein said active matrix display element or display is a PSVA-TFT liquid crystal display element or display without a PI alignment layer.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

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

(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 a liquid crystal as measured by means of a DSC quantitative method;

(5) S—N represents the melting point (° C.) for the transformation of a liquid crystal from a crystal state to a nematic phase;

(6) Δn represents optical anisotropy, with Δn.sub.e−n.sub.0, wherein n.sub.0 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: 25±2° C., 589 nm and using an abbe refractometer for testing;

(7) Δε represents dielectric anisotropy, with Δε=ε//−ε⊥, in which ε// is a dielectric constant parallel to a molecular axis, and ε⊥ is a dielectric constant perpendicular to the molecular axis, with the test conditions being 25±0.5° C., a 20 micron parallel cell, and INSTEC: ALCT-IR1 for testing;

(8) γ1 represents a rotary viscosity (mPa.Math.s), with the test conditions being 25±0.5° C., a 20 micron parallel cell, and INSTEC: ALCT-IR1 for testing; and

(9) ρ represents electrical resistivity (Ω.Math.cm), with the test conditions being: 25±2° C., and the test instruments being a TOYO SR6517 high resistance instrument and an LE-21 liquid electrode.

(10) VHR represents 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.

(11) τ represents response time (ms), with the test instrument being DMS-501 and the test conditions being: 25±0.5° 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°.

(12) T (%) represents transmittance, with T (%)=100%* bright state (Vop) luminance/light source luminance, with the test instrument being DMS501, and the test conditions being: 25±0.5° 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°.

(13) The compound represented by formula I may be prepared by means of the following illustrative synthesis route:

(14) ##STR00035## ##STR00036##

(15) wherein R.sub.0 and L are as defined in claim 1.

(16) R.sub.0 is preferably n-propyl, n-pentyl, or cyclopropylmethyl, and L is preferably F, methyl, or ethyl.

(17) In the examples of the invention of the present application, liquid crystal monomer structures are represented by codes, and the codes for ring structures, end groups and linking groups of liquid crystals are represented as in Tables (I) and (II) below

(18) TABLE-US-00001 TABLE (I) Codes corresponding to ring structures Ring structure Corresponding code C P G 0 Gi Y Sa Sb Sc

(19) TABLE-US-00002 TABLE (II) Codes corresponding to end groups and linking groups End group and linking group Corresponding code C.sub.nH.sub.2n+1— n- C.sub.nH.sub.2n+1O— nO— —OCF.sub.3 —OCF.sub.3 —CF.sub.2O— —CF.sub.2O— —CH.sub.2O— —O— —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)-

EXAMPLES

(20) ##STR00046##

Example 1

(21) ##STR00047##

(22) Step 1

(23) ##STR00048##

(24) 29.2 g (0.1 mol) of compound (1-a) and 20.3 g (0.1 mol) of o-methoxy-p-bromophenol are put into a 500 ml three-necked flask, 25.4 g of anhydrous sodium carbonate, 100 ml of toluene, 100 ml of water and 80 ml of ethanol are added, 0.1 g of Pd-132 is added with heating and stirring, and a reaction is carried out for 4 hours under reflux.

(25) 200 ml of water is added, it is adjusted to acidic with diluted hydrochloric acid, liquid separation is carried out, the organic phase is washed with water, is subjected to reduced pressure distillation to remove the solvent, dissolved in petroleum ether+toluene, passes through a silica gel column, and is recrystallized to obtain 33.5 g of a white crystal (1-b), with GC: 99.2% and a yield of 90%.

(26) Step 2

(27) ##STR00049##

(28) 33.5 g of the white crystal (1-b) is dissolved in 150 ml of CC14, 0.2 g of Fe powder is added, 16 g of liquid bromine is dropwise added at room temperature in 1 hour, during which the color fades rapidly, an off-gas is absorbed in an alkali liquid, the bromide color is washed away with a sodium hydrogen sulfite solution after half an hour since the addition is complete, the organic phase is washed with water, the solvent is removed by means of reduced pressure distillation, and after recrystallization from toluene+ethanol, 33.1 g of a white crystal (1-c) is obtained, with GC: 98.7% and a yield of 82%.

(29) Step 3

(30) ##STR00050##

(31) 33.1 g (0.074 mol) of the white crystal (1-c) is dissolved in 150 ml of DMF, 10.6 g of sodium carbonate is added, 15.3 g (0.1 mol) of 4-bromobutanol is dropwise added, and a reaction is carried out at 80° C. for 6 hours.

(32) The product is poured to 500 ml of water, toluene extraction is carried out, the organic phase is washed with water, and after recrystallization in toluene+ethanol, 33.1 g of a compound (1-d) is obtained, with GC: 98.4% and a yield of 86%.

(33) Step 4

(34) ##STR00051##

(35) 20.3 g (0.1 mol) of 3-bromo-2-metoxyphenol is dissolved in 100 ml of DMF, 13.8 g of sodium carbonate is added, 20.7 g (0.15 mol) of 3-bromopropanol is dropwise added at 80° C., and a reaction is carried out at 80° C. for 6 hours.

(36) The product is poured to 300 ml of water, toluene extraction is carried out, the organic phase is washed with water, and after recrystallization in ethanol, 19.8 g of a compound (1-e) is obtained, with GC: 98.4% and a yield of 76%.

(37) Step 5

(38) ##STR00052##

(39) The 19.8 g (0.076 mol) of compound (1-e), 25.3 g of a diboron ester, 8.2 g of anhydrous sodium carbonate, 100 ml of toluene, 100 ml of ethanol, 80 ml of water, and 0.4 g of tetrakistriphenylphosphine palladium are added together into a 500 ml three-necked flask, and heated to reflux with stirring for 4 hours.

(40) The reaction liquid is washed with water, the organic phase is subjected to reduced pressure distillation to remove the solvent, and after recrystallization from ethanol, 19.5 g of a light yellow crystal (1-f) is obtained, with GC: 97.4% and a yield of 83%.

(41) Step 6

(42) ##STR00053##

(43) The 19.5 g of light yellow crystal (1-f), the 33.1 g of compound (1-d), 10.6 g of anhydrous sodium carbonate, 400 ml of toluene, 200 ml of ethanol, 150 ml of water, and 0.5 g of tetrakistriphenylphosphine palladium are added together into a 500 ml three-necked flask, and heated to reflux with stirring for 4 hours.

(44) The reaction liquid is washed with water, the organic phase is subjected to reduced pressure distillation to remove the solvent, and after recrystallization from toluene, 29.1 g of a white crystal (1-g) is obtained, with GC: 98.4% and a yield of 75%.

(45) Step 7

(46) ##STR00054##

(47) The 29.1 g (0.047 mol) of white crystal (1-g) is dissolved in 500 ml of dichloromethane, 35.8 g (0.143 mol) of BBr3 is dropwise added at −30° C., and the mixture is stirred at a maintained temperature for 3 hours.

(48) 200 ml of water is added, an organic phase is separated, washed with water until neutral, and subjected to recrystallization from toluene+ethanol to obtain 22.1 g of an off-white solid (1-h), with HPLC: 97.4% and a yield of 81%.

(49) Step 8

(50) ##STR00055##

(51) The 22.1 g (0.037 mol) of an off-white solid (1-h) and 2.8 g (0.041 mol) of imidazole are added to 200 ml of tetrahydrofuran, and cooled to 0° C. under the protection of nitrogen gas, 5.9 g (0.039 mol) of tert-butyldimethylsilyl chloride is dropwise added within 40 minutes, and the mixture is stirred at a maintained temperature for 1.5 hours.

(52) 500 ml of an ammonium chloride aqueous solution is added, methyl tert-butyl ether is added for extraction, an organic phase is separated, washed with water until neutral, dried over anhydrous sodium sulfate and then subjected to spin drying to remove the solvent, and after recrystallization from toluene+ethanol, 19.2 g of an off-white solid (1-i) is obtained, with HPLC: 96.8% and a yield of 63%.

(53) Step 9

(54) ##STR00056##

(55) 19.2 g (0.023 mol) of (1-h) is put into a 500 ml three-necked flask, 150 ml of dichloromethane and 7.1 g (0.070 mol) of triethylamine are added, methacryloyl chloride is dropwise added at room temperature, and after the addition is complete, a stirred reaction is carried out for 5 hours.

(56) 200 ml of water is added, an organic phase is separated, washed with water until neutral, dried over anhydrous sodium sulfate and then subjected to spin drying to remove the solvent, and after recrystallization from toluene+ethanol, 15.3 g of an off-white solid (1-j) is obtained, with HPLC: 98.1% and a yield of 69%.

(57) Step 10

(58) ##STR00057##

(59) 15.3 g (0.016 mol) of (1-j) is put into a 500 ml three-necked flask, 150 ml of tetrahydrofuran is added and cooled to 0° C., 9.5 ml (0.019 mol) of 2 N diluted hydrochloric acid is dropwise added slowly, and after the addition is complete, a stirred reaction is carried out for 3 hours.

(60) 200 ml of a saturated sodium bicarbonate aqueous solution is added under cooling condition, methyl tert-butyl ether is added for extraction, an organic phase is separated, washed with water until neutral, dried over anhydrous sodium sulfate and then subjected to spin drying to remove the solvent, and after recrystallization from toluene+ethanol, 8.2 g of a white solid (I-1) is obtained, with HPLC: 97.1% and a yield of 70%.

Example 2

(61) ##STR00058##

(62) Step 1

(63) ##STR00059##

(64) 22.1 g (0.037 mol) of an off-white solid (1-h) as a raw material is dissolved in 200 ml of DMF, 15.3 g of potassium carbonate and 21.4 g (0.111 mol) of 2-bromoethyl methacrylate are added, and a reaction is carried out at 70° C. for 6 hours.

(65) The product is poured to 300 ml of water, toluene extraction is carried out, the organic phase is washed with water, dried over anhydrous sodium sulfate and then subjected to spin drying to remove the solvent, and after recrystallization from ethanol, 15.4 g of a compound is obtained, with GC: 98.7% and a yield of 51%.

Example 3

(66) TABLE-US-00003 Category Liquid crystal monomer code Content (%) III CY-3-O4 11 III PY-3-O2 9 III CPY-3-O2 12 III CCOY-2-O2 8 III CCY-5-O2 10 II CC-3-V 20 II CC-3-2 28.8 I I-1 1.2 Δε [1 KHz, 20° C.]: −3.1 Δn [589 nm, 20° C.]: 0.0887 Cp: 78° C. γ.sub.1: 81 mPa .Math. s.

Example 4

(67) TABLE-US-00004 Category Liquid crystal monomer code Content (%) III CY-3-O2 11 III PY-C(5)-O2 9 III COY-3-O2 12 III CCOY-2-O2 8 II PP-1-5 10 II CC-3-V1 15 II CC-3-2 5 V CCP-3-1 12 V CPP-3-2 11 VI VI-1 0.3 I I-13 1.7 Δε [1 KHz, 20° C.]: −2.9 Δn [589 nm, 20° C.]: 0.106 Cp: 65° C. γ.sub.1: 82 mPa .Math. s.

Example 5

(68) TABLE-US-00005 Category Liquid crystal monomer code Content (%) III CY-5-O2 11 III PY-3-O2 9 III COY-3-O2 16 IV Sc-C(5) O-O4 4 II PP-1-5 10 II CC-3-V1 25 II CC-3-2 5 V CCP-3-1 12 V CPP-3-2 6 I I-13 1.6 VI VI-3 0.4 Δε [1 KHz, 20° C.]: −2.8 Δn [589 nm, 20° C.]: 0.097 Cp: 60° C. γ.sub.1: 56 mPa .Math. s.

Example 6

(69) TABLE-US-00006 Category Liquid crystal monomer code Content (%) III CY-C(5)-O2 11 III PY-3O-O2 10 III CCOY-3-O2 12 III CCOY-5-O2 13 IV Sb-C(5) O-O4 4 II PP-1-5 10 II CC-3-V 20 II CC-3-V1 10 V CCP-3-O1 7.5 VI VI-1 0.3 I I-1 2.2 Δε [1 KHz, 20° C.]: −3.88 Δn [589 nm, 20° C.]: 0.102 Cp: 85° C. γ.sub.1: 110.s. After storage at −20° C. for 120 hours at low temperatures, no polymerizable monomer is precipitated out

Example 7

(70) The liquid crystal composition of Example 6 is poured into a test cell (there is no polyimide alignment layer, the thickness of the cell is 4 μm, there is an ITO electrode on the surface of the substrate, and there is no passivation layer), the liquid crystal is spontaneously aligned vertically, and the vertical alignment is stable at 0-80° C.

(71) A voltage of 15 V is applied to both sides of the test cell, UV irradiation (a main wavelength of 313 nm) is carried out for 200 s, with 0.55 mw/cm.sup.2, the voltage is then removed, and the irradiation is carried out at a light intensity of 0.20 mw/cm.sup.2 for 100 min, such that the polymer is completely polymerized, pre-tilt is established and stably present, and the liquid crystal cell can be reversibly switched by applying a voltage.

(72) In an environment of a temperature of 78° C.-80° C., the liquid crystal cell is continuously applied with a voltage and switched between dark state and bright state for 500 hours, and the pre-tilt is stably present.

(73) After the compound of formula I is polymerized, the insulation effect of PI can be achieved, and vertical alignment can be realized; polymerization takes place under voltage application conditions, and after the voltage is removed, the polymer layer can provide a sustained and stable pre-tilt, and the pre-tilt of liquid crystal molecules is very favorable for improving the response speed of the liquid crystal in an electric field.

(74) The disclosed self-alignment polymerizable compound has a linear main structure, and the compound of formula I of the present patent has a curved main structure; in addition, the distribution of the two hydroxy groups on the two ring structures can achieve a good anchoring effect; furthermore, it has a good solubility, does not easily precipitate from the liquid crystal at low temperatures, and has better low-temperature storage properties.