Liquid crystal composition and liquid crystal display element or liquid crystal display comprising same

Abstract

The present invention provides a liquid crystal composition comprising one or more compounds of general formula I and one or more compounds of general formula II; the liquid crystal composition of the present invention can work at very high and very low temperatures, has a very short response time and a better reliability to light and heat, and particularly exhibits no image retention or a significantly reduced image retention after a long time operation.

Claims

1. A liquid crystal composition, comprising one or more compounds represented by formulas I16-I27 and one or more compounds represented by formula II ##STR00023## ##STR00024## wherein alkyl represents a linear alkyl having a carbon atom number of 1-5; alkoxy represents a linear alkoxy having a carbon atom number of 1-5; alkenyl represents an alkenyl having a carbon atom number of 2-5; R.sub.3 and R.sub.4 each independently represent a linear alkyl having a carbon atom number of 1-5, a linear alkoxy having a carbon atom number of 1-5, an alkenyl having a carbon atom number of 2-5, F, Cl, CF.sub.3, OCF.sub.3, or any methylene that may be replaced with ##STR00025## ##STR00026## represents ##STR00027## and n represents 0 or 1.

2. The liquid crystal composition according to claim 1, wherein the total content by mass of said one or more compounds represented by formulas I16-I27 is 1-20%, and the total content by mass of said one or more compounds represented by formula II is 1-35%.

3. The liquid crystal composition according to claim 1, wherein said one or more compounds represented by formula II are one or more of compounds represented by formulas II1-II4, ##STR00028## R.sub.3 and R.sub.4 each independently represent a linear alkyl having a carbon atom number of 1-5, a linear alkoxy having a carbon atom number of 1-5 or an alkenyl having a carbon atom number of 2-5, or F, Cl, CF.sub.3, OCF.sub.3, ##STR00029##

4. The liquid crystal composition according to claim 1, comprising one or more selected from compounds represented by formulas I16-I27 and two or more selected from compounds represented by formulas II1-II4, and said liquid crystal composition necessarily comprises two or more compounds represented by formulas II3.

5. The liquid crystal composition according to claim 1, further comprising one or more compounds represented by formula III ##STR00030## wherein R.sub.5 and R.sub.6 each independently represent a linear alkyl having a carbon atom number of 1-5 or a linear alkoxy having a carbon atom number of 1-5; Z.sub.1 represents a single bond, CH.sub.2O or OCH.sub.2; and m represents 1 or 2.

6. The liquid crystal composition according to claim 5, further comprising one or more compounds represented by general formula IV ##STR00031## wherein R.sub.7 and R.sub.8 each independently represent a linear alkyl having a carbon atom number of 1-5 or a linear alkoxy having a carbon atom number of 1-5; and X.sub.1 represents H or F.

7. The liquid crystal composition according to claim 6, further comprising one or more compounds represented by formula V ##STR00032## wherein R.sub.9 and R.sub.10 each independently represent a linear alkyl having a carbon atom number of 1-5 or a linear alkoxy having a carbon atom number of 1-5; and X.sub.2, X.sub.3, X.sub.4, X.sub.5, X.sub.6 and X.sub.7 each independently represent H or F, with at least two representing F.

8. The liquid crystal composition according to claim 7, wherein in said liquid crystal composition, the total content in percentage by mass of said one or more compounds represented by formulas I16-I27 is 1-10%, the total content in percentage by mass of said one or more compounds represented by formula III is 1-50%, the total content in percentage by mass of said one or more compounds represented by formula IV is 1-15%, and the total content in percentage by mass of said one or more compounds represented by formula V is 1-20%.

9. The liquid crystal composition according to claim 1, further comprising one or more polymerizable compounds.

10. The liquid crystal composition according to claim 9, wherein said polymerizable compound is a compound represented by general formula RM-1 ##STR00033## wherein X.sub.8 represents H or F.

11. A liquid crystal display element or liquid crystal display comprising the liquid crystal composition 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.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

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

(2) In the following specific examples,

(3) CP represents a clear point, and is measured directly using a WRX-1S microthermal analyzer, with the temperature rise rate being set to 3 C./min.

(4) n represents optical anisotropy (589 nm, 20 C.),

(5) represents dielectric anisotropy (25 C., 1 KHz, HP4284A, 5.2 m TN left-hand rotate cell),

(6) 1 represents a rotational viscosity at 20 C. (MPa.Math.s), VHR (%) represents a charge holding ratio (5 V, 60 Hz, 20 C.), (1013 .Math.cm) represents an electrical resistivity (20 C.),

(7) ID: ion density at 70 C. (pC/cm.sup.2)

(8) represents a response time: t.sub.on+t.sub.off

(9) t.sub.on represents an on-time until reaching 90% of the maximum contrast

(10) t.sub.off represents an off-time until reaching 10% of the maximum contrast

(11) A tester for the voltage holding ratio VHR (%) and a tester for an electrical resistivity (1013 .Math.cm) are physical property evaluation systems of respectively TOY006254-type and TOY06517-type liquid crystals (a test temperature of 20 C., a time of 16 ms, and a test cell of 7.0 m).

(12) Image Persistence:

(13) an image persistence evaluation on a liquid crystal display element refers to a 4-level evaluation below on the ghosting level of a specified fixed pattern by visual inspection during uniformly displaying the full image after allowing the fixed pattern to display for 1,000 hours in a display area.

(14) no ghosting

(15) minor ghosting, in a permissible level

(16) ghosting, in an impermissible level

(17) x ghosting, in a quite poor level

(18) In addition, 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.

(19) TABLE-US-00001 TABLE (I) Codes corresponding to cyclic structures Cyclic structures Corresponding codes C B B(3F) B(3F, 5F) Y DFDB(S)F H(5) 0 H(4) H(3)

(20) TABLE-US-00002 TABLE (II) Codes corresponding to end groups and linking groups End groups and linking groups Corresponding codes C.sub.nH.sub.2n+1 n C.sub.nH.sub.2n+1O nO CF.sub.3 CF.sub.3 OCF.sub.3 OCF.sub.3 CF.sub.2O Q F F CH.sub.2CH.sub.2 V

(21) For example:

(22) ##STR00022##

(23) The following tables relate to the formulations and basic optical parameters of a comparative liquid crystal composition and 6 liquid crystal compositions:

(24) Comparative Liquid Crystal Composition:

(25) TABLE-US-00003 Classification Liquid crystal monomer codes Content (%) CCB-3-5 10 III C1OY-3-O2 30 III CY-3-O2 20 IV CGPC-3-3 5 V PYP-2-3 10 CC-3-V 15 CC-3-2 10 n[589 nm, 20 C.]: 0.1085 Cp[ C.]: 75 [1 KHz, 20 C.]: 3 .sub.1[mPa .Math. s, 20 C.]: 105

(26) Liquid Crystal Composition 1

(27) TABLE-US-00004 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-3O-O2 0.5 I DFDB(S)F-2-O5 0.5 I DFDB(S)F-2-V 0.5 II CB-3-5 2 II CBB-5-2 3 III C1OY-3-O2 20 III CY-3-O2 30 IV CGPC-3-3 5 V PYP-2-3 5 CC-3-V 23.5 CC-3-2 10 n[589 nm, 20 C.]: 0.1083 Cp[ C.]: 90 [1 KHz, 20 C.]: 3.5 .sub.1[mPa .Math. s, 20 C.]: 60

(28) Liquid Crystal Composition 2

(29) TABLE-US-00005 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-V-V 1 I DFDB(S)F-2O-O5 2 I DFDB(S)F-V-F 2 II CBB-3-2 3 II CBC-3-O2 7 III CY-3-O2 20 III CCY-3-O2 20 IV CPPC-3-3 3 V PPY-2-3 2 CC-3-V 20 CC-3-2 20 n[589 nm, 20 C.]: 0.1001 Cp[ C.]: 90.5 [1 KHz, 20 C.]: 3.4 .sub.1[mPa .Math. s, 20 C.]: 62

(30) Liquid Crystal Composition 3

(31) TABLE-US-00006 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-2O-F 5 I DFDB(S)F-V-CF3 2 I DFDB(S)F-2O-CF3 3 II CBB-3-2 7 II CBC-3-O2 8 II CCY-3-O4 15 III C1OY-2-O5 15 IV CGPC-2-5 10 V PGY-2-3 10 CC-3-V 15 CC-3-2 10 n[589 nm, 20 C.]: 0.0998 Cp[ C.]: 91 [1 KHz, 20 C.]: 3.8 .sub.1[mPa .Math. s, 20 C.]: 69

(32) Liquid Crystal Composition 4

(33) TABLE-US-00007 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-3-F 5 I DFDB(S)F-V-OCF3 5 I DFDB(S)F-2O-OCF3 5 II CB-3-O2 10 II CBG-3-O2 10 III CC1OY-3-2 13 III CC1OY-3-O2 7 IV CGPC-2-5 15 V PGY-2-3 15 CC-3-V 10 CC-3-2 5 n[589 nm, 20 C.]: 0.1083 Cp[ C.]: 96 [1 KHz, 20 C.]: 4.0 .sub.1[mPa .Math. s, 20 C.]: 65

(34) Liquid Crystal Composition 5

(35) TABLE-US-00008 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-3-CF3 10 I DFDB(S)F-3-OCF3 5 I DFDB(S)F-V-O2 5 II CB-V-1 20 II CBB-V-2 10 III C1OY-3-O2 5 III CC1OY-4-O3 5 IV CGPC-2-3 10 V PPY-2-3 20 CC-3-V 5 CC-3-2 5 n[589 nm, 20 C.]: 0.1088 Cp[ C.]: 89 [1 KHz, 20 C.]: 4.5 .sub.1[mPa .Math. s, 20 C.]: 66

(36) Liquid Crystal Composition 6

(37) TABLE-US-00009 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-H(3)1-2 1 I DFDB(S)F-H(3)1-O2 1 I DFDB(S)F-H(3)1-V 1 II CBG-3-2 5 II CB-3-F 5 III C1OY-3-O2 15 III CY-3-O2 20 IV CGPC-2-3 5 V PPY-2-3 10 CC-3-V 20 CC-3-2 17 n[589 nm, 20 C.]: 0.0986 Cp[ C.]: 88 [1 KHz, 20 C.]: 4.6 .sub.1[mPa .Math. s, 20 C.]: 67

(38) Liquid Crystal Composition 7

(39) TABLE-US-00010 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-H(3)1-F 4 I DFDB(S)F-H(3)1-CF3 4 I DFDB(S)F-H(3)1-OCF3 4 II CBC-3-2 7 II CB-3-2 8 III C1OY-3-O2 15 III CC1OY-3-O2 15 IV CGPC-2-3 8 V PGY-2-3 7 CC-3-V 10 CC-3-2 18 n[589 nm, 20 C.]: 0.0979 Cp[ C.]: 90 [1 KHz, 20 C.]: 4.8 .sub.1[mPa .Math. s, 20 C.]: 67

(40) Liquid Crystal Composition 8

(41) TABLE-US-00011 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-H(5)1-2 6 I DFDB(S)F-H(5)1-O2 6 I DFDB(S)F-H(5)1-V 6 II CBB-3-2 5 II CB-3-O2 5 III C1OY-3-O2 25 III CC1OY-3-O2 25 IV CGPC-2-3 2 V PGY-2-3 5 CC-3-V 7 CC-3-2 8 n[589 nm, 20 C.]: 0.1030 Cp[ C.]: 91 [1 KHz, 20 C.]: 4.8 .sub.1[mPa .Math. s, 20 C.]: 68

(42) Liquid Crystal Composition 9

(43) TABLE-US-00012 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-H(5)1-F 5 I DFDB(S)F-H(5)1-CF3 2 I DFDB(S)F-H(5)1-OCF3 3 II CBB-3-2 7 II CBB-5-2 8 III C1OY-5-O2 15 III CC1OY-3-O2 15 IV CGPC-2-3 10 V PGY-2-3 5 CC-3-V 15 CC-3-2 15 n[589 nm, 20 C.]: 0.1008 Cp[ C.]: 91 [1 KHz, 20 C.]: 3.2 .sub.1[mPa .Math. s, 20 C.]: 70

(44) Liquid Crystal Composition 10

(45) TABLE-US-00013 Classification Liquid crystal monomer codes Content (%) I DFDB(S)F-H(5)1O-O2 5 I DFDB(S)F-H(3)1O-O4 4 I DFDB(S)F-2O-O3 3 I DFDB(S)F-3O-O2 3 I DFDB(S)F-3O-O4 5 II CBB-3-2 7 II CBB-5-2 8 II CB-3-O2 20 II CB-V-O2 15 II CBB-V-2 15 II CBB-4-2 15 n[589 nm, 20 C.]: 0.112 Cp[ C.]: 90 [1 KHz, 20 C.]: 3.2 .sub.1[mPa .Math. s, 20 C.]: 180

(46) Horizontally aligned alignment films are formed on the respective opposite sides of a colour filter glass substrate and an array substrate, followed by a weak friction treatment, to manufacture an IPS (In-Plane Switching) unit, and the comparative liquid crystal composition and liquid crystal compositions 1-9 as shown below are sandwiched between the two substrates, characterized in that the liquid crystal molecules between the two substrates are in a horizontal switch molecular arrangement; and the VHRs, IDs and response times of the resulting liquid crystal display elements are measured. Moreover, an image persistence evaluation is carried out on the resulting liquid crystal display elements.

(47) The following table relates to the performance evaluation measurement data of an IPS liquid crystal display and 10 liquid crystals:

(48) TABLE-US-00014 Comparative Example Example 1 Example 2 Example 3 Example 4 Liquid Comparative Liquid Liquid Liquid Liquid crystal liquid crystal crystal crystal crystal crystal composition composition composition 1 composition 2 composition 3 composition 4 VHR 99.0 99.3 99.5 99.6 99.3 ID 77 51 25 36 42 (ms) 70 35 38 40 37 Image persistence Example Example 5 Example 6 Example 7 Example 8 Example 9 10 Liquid Liquid Liquid Liquid Liquid Liquid Liquid crystal crystal crystal crystal crystal crystal crystal composition composition 5 composition 6 composition 7 composition 8 composition 9 composition 10 VHR 99.3 99.5 99.6 99.3 99.7 99.8 ID 51 25 36 42 40 39 (ms) 35 38 40 37 41 70 Image persistence

(49) In addition, specific regions of the inner surfaces of a colour filter glass substrate and an array substrate are coated with a vertical alignment agent or a kind of material as an auxiliary alignment agent is added to a crystal to manufacture a VA (Vertical Alignment) unit, and liquid crystal molecules in the comparative liquid crystal composition and liquid crystal compositions 1-9 are vertically aligned on the surfaces of the substrates of the liquid crystal display device; and the VHRs, IDs and response times of the resulting liquid crystal display elements are measured. Moreover, an image persistence evaluation is carried out on the resulting liquid crystal display elements.

(50) The following table relates to the performance evaluation measurement data of a VA liquid crystal display and 10 liquid crystals:

(51) TABLE-US-00015 Comparative Example Example 1 Example 2 Example 3 Example 4 Liquid Comparative Liquid Liquid Liquid Liquid crystal liquid crystal crystal crystal crystal crystal composition composition composition 1 composition 2 composition 3 composition 4 VHR 99.1 99.3 99.5 99.6 99.3 ID 77 51 25 36 42 (ms) 55.5 35 38 40 37 Image persistence Example Example 5 Example 6 Example 7 Example 8 Example 9 10 Liquid Liquid Liquid Liquid Liquid Liquid Liquid crystal crystal crystal crystal crystal crystal crystal composition composition 5 composition 6 composition 7 composition 8 composition 9 composition 10 VHR 99.3 99.5 99.6 99.3 99.7 99.8 ID 51 25 36 42 40 39 (ms) 35 38 40 37 41 69 Image persistence

(52) As can be seen obviously from the test results above, the negative dielectric anisotropic liquid crystal compositions disclosed in the present invention have a lower rotational viscosity value, and the IPS (In-Plane Switching) displays and VA (Vertical Alignment) displays manufactured using the negative dielectric anisotropic liquid crystal compositions disclosed in the present invention have a higher VHR, better reliability, a shorter ID and a shorter T, are more excellent in performance in the image persistence evaluation, and particularly have no image retention after a long time operation, as compared with the comparative example.