LIQUID CRYSTAL COMPOSITION CONTAINING DIBENZO DERIVATIVES AND LIQUID CRYSTAL DISPLAY DEVICE

Abstract

The present application provides a liquid crystal composition containing dibenzo derivatives and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I and at least one compound of general formula II.

##STR00001##

Claims

1. A liquid crystal composition containing a dibenzo derivative, including at least one compound of general formula I and at least one compound of general formula II: ##STR00090## in which, R represents —H, halogen, —CN, C.sub.1-12 linear or branched alkyl, ##STR00091##  one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl, ##STR00092##  may be respectively and independently replaced by —CH═CH—, —C≡C—, —O—, —S—, —CO—, —CO—O— or —O—CO—, one or at least two —H in the aforesaid groups may be respectively and independently substituted by —F or —Cl; R.sub.x represents —H, C.sub.1-12 linear or branched alkyl, one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —CH═CH—, —C≡C—, —O—, —S—, —CO—, —CO—O— or —O—CO—, one or at least two —H in the C.sub.1-12 linear or branched alkyl may be respectively and independently substituted by —F or —Cl, R.sub.x is attached to an arbitrary carbon atom in ring ##STR00093## R.sub.1 and R.sub.2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00094##  one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—; ring ##STR00095##  represents ##STR00096##  one or at least two single bond within the ring of the aforesaid groups may be replaced by double bond; ring ##STR00097##  represents ##STR00098##  one or at least two —CH.sub.2— in ##STR00099##  may be replaced by —O—, one or at most two single bond within the ring may be replaced by double bond; one or at least two —H in ##STR00100##  may be substituted by —F or —Cl, one or at least two —CH═ within the ring may be replaced by —N═; ring ##STR00101##  represents ##STR00102##  one or at least two —CH.sub.2— in ##STR00103##  may be replaced by —O—, one or at most two single bond within the ring may be replaced by double bond; one or at least two —H in ##STR00104##  may be substituted by —F or —Cl, one or at least two —CH═ within the ring may be replaced by —N═; Z.sub.1 represents —(CH.sub.2).sub.aO— or —(CH.sub.2).sub.aS—, wherein a represents an integer of 0 to 7; Z.sub.2 represents —O—, —S—, —CO—O—, —O—CO—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2O—, —CH.sub.2S—, —OCH.sub.2—, —SCH.sub.2—, —CH.sub.2—, —CH.sub.2CH.sub.2—, —(CH.sub.2).sub.4—, —CH═CH—CH.sub.2O—, —C.sub.2F.sub.4—, —CH.sub.2CF.sub.2—, —CF.sub.2CH.sub.2—, —CF═CF—, —CH═CF—, —CF═CH—, —CH═CH—, —C≡C— or single bond; Z.sub.3 represents single bond, —CO—O—, —O—CO—, —CH.sub.2O—, —OCH.sub.2—, —CH═CH—, —C≡C—, —CH.sub.2CH.sub.2—, —(CH.sub.2).sub.4—, —CF.sub.2O—, —OCF.sub.2— or —CF.sub.2CF.sub.2—; L.sub.1 and L.sub.2 each independently represents —F, —Cl, —CF.sub.3 or —CHF.sub.2; X represents —CO—, —S— or —O—; n represents 0, 1 or 2, wherein when n represents 2, ring ##STR00105##  is same or different, Z.sub.2 is same or different; m represents 0, 1 or 2, wherein when m represents 2, ring ##STR00106##  is same or different, Z.sub.3 is same or different; and at least one group of the following three groups: R.sub.1, ring ##STR00107##  and Z.sub.3, contains at least one of —CH═CH— or —C≡C—.

2. The liquid crystal composition according to claim 1, wherein n represents 0.

3. The liquid crystal composition according to claim 1, wherein both L.sub.1 and L.sub.2 represent —F.

4. The liquid crystal composition according to claim 1, wherein X represents —O— or —S—; optionally, a represents an integer of 0-3; optionally, R represents C.sub.1-12 linear or branched alkyl, or one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —O— or —S—; optionally, R.sub.x represents —H, C.sub.1-12 linear or branched alkyl; optionally, the liquid crystal composition contains at least one compound of general formula I in which X represents —O—; optionally, the liquid crystal composition contains at least one compound of general formula I in which X represents —O— and at least one compound of general formula I in which X represents —S—.

5. The liquid crystal composition according to claim 1, wherein the compound of general formula I comprises 0.1-40% of the total weigh of the liquid crystal composition; optionally, the compound of general formula I comprises 1-30% of the total weight of the liquid crystal composition.

6. The liquid crystal composition according to claim 1, wherein the compound of general formula II meets at least one of following conditions a)˜c): a) R.sub.1 represents C.sub.2-10 alkenyl or alkenoxy; b) when m represents 1 or 2, at least one ring ##STR00108##  represents ##STR00109## c) when m represents 1 or 2, at least one Z.sub.3 represents —CH═CH— or —C≡C—; optionally, the compound of general formula II is selected from a group consisting of the following compounds: ##STR00110## ##STR00111## in which, R.sub.alkenyl represents C.sub.2-7 alkenyl; R.sub.1 and R.sub.2 each independently represents C.sub.1-10 linear alkyl or alkoxy, or C.sub.2-10 linear alkenyl or alkenoxy.

7. The liquid crystal composition according to claim 1, wherein the compound of general formula II comprises 0.1-50% of the total weight of the liquid crystal composition; optionally, the compound of general formula II comprises 1-45% of the total weight of the liquid crystal composition; further optionally, the compound of general formula II comprises 5-43% of the total weight of the liquid crystal composition.

8. The liquid crystal composition according to claim 1, wherein the liquid crystal composition further includes one or at least two compound of general formula M ##STR00112## in which, R.sub.M1 and R.sub.M2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00113##  one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—; ring ##STR00114##  ring ##STR00115##  and ring ##STR00116##  each independently represents ##STR00117##  one or at least two —CH.sub.2— in ##STR00118##  may be replaced by —O—, at most one —H in ##STR00119##  may be substituted by halogen; Z.sub.M1 and Z.sub.M2 each independently represents single bond, —CO—O—, —O—CO—, —CH.sub.2O—, —OCH.sub.2—, —CH═CH—, —C≡C—, —CH.sub.2CH.sub.2—, —(CH.sub.2).sub.4—, —CF.sub.2O—, —OCF.sub.2— or —CF.sub.2CF.sub.2—; n.sub.M1 represents 0, 1, 2 or 3, wherein when n.sub.M1=2 or 3, ring ##STR00120##  is same or different, Z.sub.M2 is same or different; optionally, the compound of general formula M is selected from a group consisting of the following compounds: ##STR00121## ##STR00122## ##STR00123## in which, R.sub.M1 and R.sub.M2 each independently represents C.sub.1-12 linear or branched alkyl, or one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —CH═CH— or —O—; optionally, R.sub.M1 and R.sub.M2 each independently represents C.sub.1-10 linear alkyl, C.sub.2-10 linear alkenyl or C.sub.1-9 linear alkoxy; optionally, the liquid crystal composition includes one or at least two compound of general formula M1 in which R.sub.M1 and/or R.sub.M2 is n-propyl; optionally, the compound of general formula M comprises 1-70% of the total weight of the liquid crystal composition.

9. The liquid crystal composition according to claim 1, wherein the liquid crystal composition further includes one or at least two compound of general formula N ##STR00124## in which, R.sub.N1 and R.sub.N2 each independently represents C.sub.1-12 linear or branched alkyl, or ##STR00125##  one or at least two nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl may be respectively and independently replaced by —O—, —CO—, —CO—O— or —O—CO—, one or at least two —H in the C.sub.1-12 linear or branched alkyl, ##STR00126##  may be respectively and independently substituted by —F or —Cl; ring ##STR00127##  or ring ##STR00128##  each independently represents ##STR00129##  one or at least two —CH.sub.2— in ##STR00130##  may be replaced by —O—; one or at least two —H in ##STR00131##  may be substituted by —F or —Cl, one or at least two —CH═ within the ring may be replaced by —N═; Z.sub.N1 and Z.sub.N2 each independently represents single bond, —CO—O—, —O—CO—, —CH.sub.2O—, —OCH.sub.2—, —CH.sub.2CH.sub.2—, —(CH.sub.2).sub.4—, —CF.sub.2O—, —OCF.sub.2— or —CF.sub.2CF.sub.2—; L.sub.N1 and L.sub.N2 each independently represents —H or methyl; n.sub.N1 represents 0, 1, 2 or 3, n.sub.N2 represents 0 or 1, and 0≤n.sub.N1+n.sub.N2≤3, wherein when n.sub.N1=2 or 3, ring ##STR00132##  is same or different, Z.sub.N1 is same or different; optionally, the compound of general formula N is selected from a group consisting of the following compounds: ##STR00133## ##STR00134## ##STR00135## in which, R.sub.N1 represents C.sub.1-5 linear or branched alkyl, R.sub.N2 represents C.sub.1-4 linear or branched alkoxy; optionally, the compound of general formula N comprises 1-75% of the total weight off the liquid crystal composition.

10. A liquid crystal display device including the liquid crystal composition of claim 1; optionally, the liquid crystal display device is an IPS mode liquid crystal display device, an FFS mode liquid crystal display device or a VA mode liquid crystal display device.

Description

DETAILED EMBODIMENTS

[0112] The technical solutions of the present application will be further described below in conjunction with specific embodiments. Those skilled in the art should understand that the following examples are exemplary embodiments of the present application, which are only used to illustrate and help understand the present application and should not be construed as limitations to the present application. Other combinations and various modifications within the conception of the present application are possible without departing from the subject matter or scope of the present application.

[0113] In the present application, unless otherwise specified, the proportions mentioned in the present application are weight ratios, and temperatures are Celsius temperatures.

[0114] For the convenience of the expression, the group structures of the liquid crystal compositions in the following Examples are represented by the codes listed in Table 1:

TABLE-US-00001 TABLE 1 Codes of the group structures of the liquid crystal compounds Unit structure of group Code Name of group [00074] C 1,4-cyclohexylidene [00075] L 1,4-cyclohexenylene [00076] P 1,4-phenylene [00077] G 2-fluoro-1,4-phenylene [00078] W 2,3-difluoro-1,4-phenylene [00079] B(O) 4,6-difluoro-dibenzo[b,d]furan- 3,7-diyl [00080] B(S) 4,6-difluoro-dibenzo[b,d]thio- phene-3,7-diyl [00081] THF(2,5) tetrahydrofuran-2,5-diyl [00082] THT(2,5) tetrahydrothiophene-2,5-diyl [00083] THF tetrahydrofuran-2-yl [00084] THF(3) tetrahydrofuran-3-yl [00085] DHF(1) 4,5-dihydrofuran-2-yl [00086] THT tetrahydrothiophene-2-yl [00087] THT(3) tetrahydrothiophene-3-yl [00088] DHT(1) 4,5-dihydrothiophene-2-yl —CH.sub.2CH.sub.2— 2 ethyl bridge bond —CH.sub.2CH.sub.2CH.sub.2— 3 propyl bridge group —CH.sub.2O— 1O methyleneoxy —F— F fluorine substituent —O— O oxygen bridge group —S— S sulfur bridge group —C.sub.nH.sub.2n+1 n (n represents a alkyl positive integer of 1-12) —C≡C— or —C≡CH T ethynyl —CH=CH— or —CH=CH.sub.2 V ethenyl

[0115] Take the compound with the following structural formula as an example:

##STR00089##

[0116] Represented by the codes listed in Table 1, this structural formula can be expressed as nCCGF, n in the code represents the number of the carbon atoms of the alkyl group on the left, for example, n is “3”, meaning that the alkyl is —C.sub.3H.sub.7; C in the code represents 1,4-cyclohexylidene, G represents 2-fluoro-1,4-phenylene, F represents fluorine substituent.

[0117] The abbreviated codes of the test items in the following Examples are as follows: [0118] Cp clearing point (nematic-isotropy phases transition temperature, ° C.) [0119] Δεdielectric anisotropy (1 KHz, 25° C.) [0120] ε.sub.⊥ dielectric constant perpendicular to the molecular axis (1 KHz, 25° C.) [0121] ε.sub.⊥/|Δε| ratio of perpendicular dielectric constant to the absolute value of dielectric constant [0122] Δn optical anisotropy (light wavelength 589 nm, 25° C.) [0123] K.sub.ave average elastic constant [0124] T (%) Transmittance (DMS 505, cell gap 3.5 m) in which, [0125] Cp: measured by using a melting point apparatus;

[0126] Δε: Δε=ε.sub.|-ε.sub.⊥, wherein ε.sub.| is a dielectric constant parallel to the molecular axis, ε.sub.⊥ is a dielectric constant perpendicular to the molecular axis, and the test conditions are: 25° C., 1 KHz, and a TN90 test cell with a cell gap of 7 μm;

[0127] Δn: measured by using Abbe refractometer under the light source of sodium lamp (589 nm) and at 25° C.;

[0128] K.sub.ave=⅓ (K.sub.11+K.sub.22+K.sub.33), and Ki, K.sub.22, and K.sub.33 were calculated by testing the C-V curve of liquid crystal using the LCR instrument and anti-parallel friction cells with the test conditions: a 7 m anti-parallel friction cell and V=0.1 ˜20V.

[0129] Test conditions of transmittance: the V-T curve of a dimming device, which was a negative IPS-type test cell with a cell gap of 3.5 μm, was tested by using DMS 505 photoelectric comprehensive tester, and the T.sub.max value in the V-T curve was the transmittance of the liquid crystal material.

[0130] Each component adopted in the following Examples can be synthesized by well-known methods or can be obtained commercially. These synthesis techniques are conventional, and the obtained liquid crystal compositions have been tested and proved to meet the standards of electronic compounds.

[0131] Liquid crystal compositions were prepared according to the proportions of liquid crystal compositions specified in the following Examples. The preparation of the liquid crystal compositions was carried out according to the conventional methods in the art, such as heating, ultrasonic wave, suspension, and the like, and by mixing components according to specified proportions.

Comparative Example 1

[0132] A liquid crystal composition, whose components and performance parameters are shown in Table 2.

TABLE-US-00002 TABLE 2 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 10.5 N2 Cp 94 3CLWO2 9 II-5 Δn 0.11 3LCWO2 9 II-6 Δ∈ −3.9 5CCWO2 9.5 N5 ∈.sub.⊥ 6.7 5CWO2 10 N2 K.sub.ave 12.7 3CWO4 9 N2 T 13.3% 2PWP3 3 N13 ∈.sub.⊥/|Δ∈| 1.72 2CPWO2 7 N11 3CPWO2 7 N11 THF2B(O)O6 5 3CCV 15 M1 VCCP1 3 M12 3CCP1 3 M12 Total 100

Comparative Example 2

[0133] A liquid crystal composition, whose components and performance parameters are shown in Table 3.

TABLE-US-00003 TABLE 3 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 10.5 N2 Cp 94 3CLWO2 9 II-5 Δn 0.109 3LCWO2 9 II-6 Δ∈ −3.9 5CCWO2 9.5 N5 ∈.sub.⊥ 6.6 5CWO2 10 N2 K.sub.ave 12.6 3CWO4 9 N2 T 13.2% 2PWP3 3 N13 ∈.sub.⊥/|Δ∈| 1.69 2CPWO2 7 N11 3CPWO2 7 N11 C(5)1OB(O)O6 5 3CCV 15 M1 VCCP1 3 M12 3CCP1 3 M12 Total 100

Example 1

[0134] A liquid crystal composition, whose components and performance parameters are shown in Table 4.

TABLE-US-00004 TABLE 4 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 10.5 N2 Cp 94 3CLWO2 9 II-5 Δn 0.111 3LCWO2 9 II-6 Δ∈ −4 5CCWO2 9.5 N5 ∈.sub.⊥ 7 5CWO2 10 N2 K.sub.ave 13.2 3CWO4 9 N2 T 14.2% 2PWP3 3 N13 ∈.sub.⊥/|Δ∈| 1.75 2CPWO2 7 N11 3CPWO2 7 N11 THF1OB(O)O6 5 I 3CCV 15 M1 VCCP1 3 M12 3CCP1 3 M12 Total 100

Example 2

[0135] A liquid crystal composition, whose components and performance parameters are shown in Table 5.

TABLE-US-00005 TABLE 5 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3LWO2 10 II-3 Cp 96 3CCWO2 5 N5 Δn 0.112 3LCWO2 9 II-6 Δ∈ −4 3CLWO2 9 II-5 ∈.sub.⊥ 7.3 5LWO2 10 II-3 K.sub.ave 13.6 3CWO4 9 N2 T 14.7% 2PWP3 3 N13 ∈.sub.⊥/|Δ∈| 1.83 2CPWO2 4 N11 3LPWO2 5 II-7 2THF(2,5)1OB(S)O4 6 I THF1OB(O)O6 5 I 3CCV 17 M1 VCCP1 4 M12 3CCP1 4 M12 Total 100

Example 3

[0136] A liquid crystal composition, whose components and performance parameters are shown in Table 6.

TABLE-US-00006 TABLE 6 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 10 N2 Cp 95 2CCWO2 9 N5 Δn 0.114 3CCWO2 9 N5 Δ∈ −4 5CCWO2 10 N5 ∈.sub.⊥ 7.2 5CWO2 7 N2 K.sub.ave 13.3 3CWO4 7 N2 T 14.3% VCPWO2 4 II-2 ∈.sub.⊥/|Δ∈| 1.8 1VCPWO2 5 II-2 3CPWO2 6 N11 THF2SB(S)O6 4 I THF1OB(O)S4 5 I DHT(1)1OB(O)O6 3 I 3CCV 15 M1 VCCP1 3 M12 3CCP1 3 M12 Total 100

Example 4

[0137] A liquid crystal composition, whose components and performance parameters are shown in Table 7.

TABLE-US-00007 TABLE 7 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 10 N2 Cp 95 2CCWO2 8 N5 Δn 0.116 3CCWO2 7 N5 Δ∈ −4.2 5CCWO2 7 N5 ∈.sub.⊥ 7.5 5CWO2 9 N2 K.sub.ave 13.5 3CWO4 8 N2 T 14.7% 3PTWO2 5 II-9 ∈.sub.⊥/|Δ∈| 1.79 3CPTWO2 4 II-10 THF2OB(O)S6 3 I THF3OB(S)O4 5 I DHF(1)1OB(O)O6 3 I THF1OB(O)O4 5 I THT1OB(O)O6 5 I 3CCV 15 M1 VCCP1 3 M12 3CCP1 3 M12 Total 100

Example 5

[0138] A liquid crystal composition, whose components and performance parameters are shown in Table 8.

TABLE-US-00008 TABLE 8 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 6 N2 Cp 94 3CCWO2 6 N5 Δn 0.113 3CCWO2 7 N5 Δ∈ −4.3 3LCWO2 5 II-6 ∈.sub.⊥ 7.5 3CWO2 6 N2 K.sub.ave 13.5 5CWO2 5 N2 T 14.7% 3CWO4 7 N2 ∈.sub.⊥/|Δ∈| 1.74 2CPWO2 7 N11 3CPWO2 7 N11 THF2OB(O)S6 5 I THF3OB(S)O4 5 I 2THT(2,5)1OB(O)O6 3 I THF(3)1OB(O)O4 3 I THT1OB(O)O6 5 I 3CCV 15 M1 VCCP1 2 M12 3CCP1 2 M12 3CPO2 4 M2 Total 100

Example 6

[0139] A liquid crystal composition, whose components and performance parameters are shown in Table 9.

TABLE-US-00009 TABLE 9 Components and performance parameters of the liquid crystal composition Weight General Performance Component code percentage formula code parameters 3CWO2 4 N2 Cp 97 3CWO4 5 N2 Δn 0.121 5CWO2 5 N2 Δ∈ −4.3 5CWO4 5 N2 ∈.sub.⊥ 7.8 VCPWO2 7 II-2 K.sub.ave 13.9 1VCPWO2 8 II-2 T 15.3% 1V2CPWO3 8 II-2 ∈.sub.⊥/|Δ∈| 1.81 V2CPWO2 7 II-2 THF2OB(O)S6 5 I THF3OB(S)O4 5 I 2THT(2,5)1OB(O)O6 3 I THF1SB(O)O4 5 I THT1OB(O)O6 5 I THT(3)OB(O)O5 3 I 3CCV 19 M1 VCCP1 3 M12 3CPO2 3 M2 Total 100

[0140] As can be seen from the comparison between Comparative Examples 1-2 and Example 1 as shown in above tables, through the structure optimization of the compound of general formula I and the synergistic interaction with the compound of general formula II containing a carbon-carbon unsaturated bond in the present application, the liquid crystal composition included in the present application has a larger dielectric constant perpendicular to the molecular axis ε.sub.⊥ a larger ratio of perpendicular dielectric to a absolute value of dielectric ε.sub.⊥/|Δε| and a larger average elastic constant K.sub.ave, while maintaining substantially equivalent clearing point, optical anisotropy and dielectric anisotropy, such that the liquid crystal display device including such liquid crystal composition has a higher transmittance and a higher contrast.

[0141] As can be seen from Examples 1-6 described above, the liquid crystal compositions of the present application all have high clearing point, large optical anisotropy, large dielectric anisotropy, larger dielectric constant perpendicular to the molecular axis ε.sub.⊥, larger ratio of perpendicular dielectric to a absolute value of dielectric ε.sub.⊥/|Δε| and larger average elastic constant K.sub.ave, and the liquid crystal display devices including these liquid crystal compositions all have the effects of good transmittance and high contrast. The liquid crystal compositions of the present application can meet the requirements of the liquid crystal display device on low power consumption and good display effect and have high application value in liquid crystal displays of IPS mode, FFS mode, and VA mode.

[0142] The applicant has stated that although the liquid crystal composition containing a dibenzo derivative and the liquid crystal display device of the present application are illustrated through the Examples described above in the present application, the present application is not limited to the processes and steps described above, which means that the implementation of the present application does not necessarily depend on the processes and steps described above.

[0143] The above embodiments are merely illustrative of the technical concepts and the features of the present application, and the purpose thereof is to enable those familiar with the art to understand the content of the present application and implement the present application, and should not be used to limit the protection scope of the present application.