LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY DEVICE COMPRISING THE SAME

Abstract

A liquid crystal composition includes at least one compound of general formula F and at least one compound of general formula N. A liquid crystal display device includes the liquid crystal composition. The liquid crystal composition has a larger K value, a smaller rotational viscosity, a higher VHR value, a longer low temperature storage time and a shorter response time while maintaining an appropriate clearing point, an appropriate optical anisotropy, and an appropriate absolute value of dielectric anisotropy, such that the liquid crystal display device including the liquid crystal composition has a better contrast, a wider temperature range for application, a faster response speed, a better contrast and a higher reliability.

##STR00001##

Claims

1. A liquid crystal composition comprising: at least one compound of general formula F ##STR00128## and at least one compound of general formula N in an amount of 10%-45% by weight of the total weight of the liquid crystal composition ##STR00129## wherein, R.sub.F1 represents —H, halogen, C.sub.1-12 linear or branched alkyl, ##STR00130## one or more nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl can each be independently replaced by —C≡C—, —O—, —CO—, —CO—O— or —O—CO—, and one or more —H in the C.sub.1-12 linear or branched alkyl can each be independently substituted by —F or —Cl; R.sub.F2 represents ##STR00131## of which at least one single bond in the ring is replaced by double bond or ##STR00132## R.sub.N1 and R.sub.N2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00133## one or more nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—; ring ##STR00134## and ring ##STR00135## each independently represents ##STR00136## wherein one or more —CH.sub.2 in ##STR00137## can be replaced by —O—, one or more single bond in the rings can be replaced by double bond, wherein one or more —H on ##STR00138## and can each be independently substituted by —CN, —F or —Cl, and one or more —CH═ in the rings can be replaced by —N═; ring ##STR00139## and ring ##STR00140## each independently represents ##STR00141## wherein one or more —CH.sub.2— in ##STR00142## can be replaced by —O—, one or more single bond in the rings can be replaced by double bond, wherein one or more —H on ##STR00143## can be substituted by —F, —Cl or —CN, and one or more —CH═ in the rings can be replaced by —N═; X.sub.F represents —O—, —S— or —CO—; L.sub.F1 and L.sub.F2 each independently represents —H, —F, —Cl, —CF.sub.3 or —OCF.sub.3; L.sub.N1 and L.sub.N2 each independently represents —H, C.sub.1-3 alkyl or halogen; Z.sub.F1, Z.sub.F2, Z.sub.F4, Z.sub.N1 and Z.sub.N2 each independently represents single bond, —O—, —CO—O—, —O—CO—, —CH.sub.2O—, —OCH.sub.2—, —CH═CH—, —C≡C—, —CH.sub.2CH.sub.2—, —CF.sub.2CF.sub.2—, —(CH.sub.2).sub.4—, —CF.sub.2O— or —OCF.sub.2—; n.sub.F1 and n.sub.F2 each independently represents 0, 1 or 2, wherein, when n.sub.F1 represents 2, ring ##STR00144## can be same or different, when n.sub.F2 represents 2, ring ##STR00145## can be same or different, and Z.sub.F2 can be same or different; n.sub.F3 represents an integer of 0-4; and 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, when n.sub.N1=2 or 3, ring ##STR00146## can be same or different, and Z.sub.N1 can be same or different.

2. The liquid crystal composition according to claim 1, wherein the compound of general formula F is selected from a group consisting of the following compounds: ##STR00147## ##STR00148## ##STR00149## wherein, X.sub.F1 and X.sub.F2 each independently represents —CH.sub.2— or —O—.

3. The liquid crystal composition according to claim 1, wherein the compound of general formula N is selected from a group consisting of the following compounds: ##STR00150## ##STR00151## ##STR00152## ##STR00153##

4. The liquid crystal composition according to claim 1, wherein the liquid crystal composition comprises at least one compound of general formula M ##STR00154## wherein, R.sub.M1 and R.sub.M2 each independently represents C.sub.1-12 linear or branched alkyl, ##STR00155## one or more nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl can each be independently replaced by —CH═CH—, —C≡C—, —O—, —CO—, —CO—O— or —O—CO—; ring ##STR00156## ring ##STR00157## and ring ##STR00158## each independently represents ##STR00159## wherein one or more —CH.sub.2— in ##STR00160## can be replaced by —O— one or more single bond in the rings can be replaced by double bond, at most one —H on ##STR00161## can 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—, —C≡C—, —CH═CH—, —CH.sub.2CH.sub.2— or —(CH.sub.2).sub.4—; and n.sub.M represents 0, 1 or 2, wherein when n.sub.M=2, ring ##STR00162## can be same or different, and Z.sub.M2 can be same or different.

5. The liquid crystal composition according to claim 4, wherein the compound of general formula M is selected from a group consisting of the following compounds: ##STR00163## ##STR00164## ##STR00165##

6. The liquid crystal composition according to claim 4, wherein the liquid crystal composition comprises at least one compound of general formula B ##STR00166## wherein, R.sub.B1 and R.sub.B2 each independently represents halogen, —CF.sub.3, —OCF.sub.3, C.sub.1-12 linear or branched alkyl, ##STR00167## one or more nonadjacent —CH.sub.2— in the C.sub.1-12 linear or branched alkyl, ##STR00168## can each be independently replaced by —C≡C—, —O—, —CO—, —CO—O— or —O—CO—; ring ##STR00169## and ring ##STR00170## each independently represents ##STR00171## wherein one or more —CH.sub.2— in ##STR00172## can be replaced by —O—, one or more single bond in the rings can be replaced by double bond, wherein one or more —H on ##STR00173## can each be independently substituted by —CN, —F or —C.sub.1, and one or more —CH═ in the rings can be replaced by —N═; X.sub.B represents —O—, —S— or —CO—; L.sub.B1 and L.sub.B2 each independently represents —H, —F, —Cl, —CF.sub.3 or —OCF.sub.3; Z.sub.B1 and Z.sub.B2 each independently represents single bond, —O—, —CO—O—, —O—CO—, —CH.sub.2O—, —OCH.sub.2—, —CH═CH—, —C≡C—, —CH.sub.2CH.sub.2—, —CF.sub.2CF.sub.2—, —(CH.sub.2).sub.4—, —CF.sub.2O— or —OCF.sub.2—; and n.sub.B1 and n.sub.B2 each independently represents 0, 1 or 2, wherein, when n.sub.B1 represents 2, ring ##STR00174## can be same or different, when n.sub.B2 represents 2, ring ##STR00175## can be same or different, and Z.sub.B2 can be same or different.

7. The liquid crystal composition according to claim 6, wherein the compound of general formula B is selected from a group consisting of the following compounds: ##STR00176## ##STR00177## wherein, R.sub.B1′ and R.sub.B2′ each independently represents C.sub.1-11 linear or branched alkyl.

8. The liquid crystal composition according to claim 6, wherein the compound of general formula F provides 0.1-30 wt. % of the total weight of the liquid crystal composition; the compound of general formula M provides 0.1-70 wt. % of the total weight of the liquid crystal composition; and the compound of general formula B provides 0.1-30 wt. % of the total weight of the liquid crystal composition.

9. The liquid crystal composition according to claim 1, wherein the liquid crystal composition comprises at least one additive.

10. A liquid crystal display device comprising the liquid crystal composition of claim 1.

Description

DETAILED EMBODIMENTS

[0142] The present invention will be illustrated by combining the detailed embodiments below. It should be noted that, the following examples are exemplary embodiments of the present invention, which are only used to illustrate the present invention, not to limit it. Other combinations and various modifications within the conception of the present invention are possible without departing from the subject matter and scope of the present invention.

[0143] For the convenience of the expression, the group structures of the liquid crystal compounds in the following Examples are represented by the codes listed in Table 2:

TABLE-US-00002 TABLE 2 Codes of the group structures of the compounds Unit structure of group Code Name of group [00105] C 1,4-cyclohexylidene [00106] P 1,4-phenylene [00107] L 1,4-cyclohexene [00108] C(5,V) cyclopentenyl [00109] G 2-fluoro-1,4-phenylene [00110] G′ 3-fluoro-1,4-phenylene [00111] W 2,3-difluoro-1,4-phenylene [00112] B(O) 4,6-difluoro-dibenzo[b,d]furan-3,7-diyl [00113] B(S) 4,6-difluoro-dibenzo[b,d]thiophene-3,7-diyl [00114] V(2F) difluoroalkenyl —F F fluorine substituent —O— O oxygen bridge bond —CH═CH— or —CH═CH.sub.2 V ethenylene or ethenyl —CH.sub.2O— 1O methyleneoxy —CH.sub.2CH.sub.2— 2 ethyl bridge bond —C.sub.nH.sub.2n+1— or —C.sub.nH.sub.2n— n (n represents alkyl or alkylene an integer of 1-12)

[0144] Take the compound with following structural formula as an example:

##STR00115##

[0145] represented by the codes listed in Table 2, this structural formula can be expressed as nCCGF, in which, n in the code represents the number of the carbon atoms of the alkyl 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, and F represents fluoro.

[0146] The abbreviated codes of the test items in the following Examples are as follows: [0147] Cp clearing point (nematic-isotropy phases transition temperature, ° C.) [0148] Δn optical anisotropy (589 nm, 20° C.) [0149] Δε dielectric anisotropy (1 KHz, 20° C.) [0150] K.sub.11 splay elastic constant [0151] K.sub.33 bend elastic constant [0152] τ.sub.off the time required to reduce the transmittance from 90% to 10% when removing the electric field (ms, 20° C.) [0153] VHR (initial) initial voltage holding ratio (%) [0154] VHR (UV) voltage holding ratio after UV-irradiation (%) [0155] voltage holding ratio after maintained at a high temperature of 150° C. for 1 hour (%) [0156] t.sub.−20° C. low-temperature storage time (day, at −20° C.) [0157] γ.sub.1 rotational viscosity (mPa.Math.s, at 20° C.)

[0158] wherein,

[0159] Cp: tested by melting point apparatus.

[0160] Δn: tested using an Abbe Refractometer under a sodium lamp (589 nm) light source at 20° C.

[0161] Δε: Δε=ε.sub.|−ε.sub.⊥, in which, ε.sub.| is the dielectric constant parallel to the molecular axis, ε.sub.⊥ is the dielectric constant perpendicular to the molecular axis, test conditions: 20° C., 1 KHz, VA-type test cell with a cell gap of 6 μm.

[0162] VHR (initial): initial voltage holding ratio, tested using a TOY06254 liquid crystal physical property evaluation system; the test temperature is 60° C., the test voltage is 5 V, the test frequency is 6 Hz, TN-type test cell with a cell gap of 9 μm.

[0163] VHR (UV): tested using a TOY06254 liquid crystal physical property evaluation system; tested after using UV light with a wavelength of 365 nm and energy of 6000 μmJ/cm.sup.2 to irradiate the liquid crystal, the test temperature is 60° C., the test voltage is 5 V, the test frequency is 6 Hz, TN-type test cell with a cell gap of 9 μm.

[0164] VHR (Ra): tested using a TOY06254 liquid crystal physical property evaluation system; the liquid crystal composition is tested after maintaining at a high temperature of 150° C. for 1 h; the test temperature is 60° C., the test voltage is 5 V, the test frequency is 6 Hz, TN-type test cell with a cell gap of 9 μm.

[0165] t.sub.−20° C. the time recorded when precipitation of crystals was observed after the nematic liquid crystal medium being placed in a glass bottle and stored at −20° C.

[0166] γ.sub.1: tested using a LCM-2 type liquid crystal physical property evaluation system; test conditions: 20° C., 160-260 V, the cell gap is 20 μm.

[0167] K.sub.11 and K.sub.33: calculated by C—V curves of liquid crystal tested by LCR meter and VA-type test cell; test conditions: the cell gap is 6 μm, V=0.1˜20 V, 20° C.

[0168] τ.sub.off: tested using a DMS 505 liquid crystal display screen optical measurement system, test conditions: negative IPS-type test cell with a cell gap of 3.5 μm, 20° C.

[0169] The components used in the following Examples can either be synthesized by method known in the art or be obtained commercially. The synthetic techniques are conventional, and each of the obtained liquid crystal compounds is tested to meet the standards of electronic compound.

[0170] The liquid crystal compositions are prepared in accordance with the ratios specified in the following Examples. The preparation of the liquid crystal compositions is proceeded according to the conventional methods in the art, such as heating, ultrasonic processing, suspending processing and so forth.

[0171] Wherein, 5PGP(NA) represents ultraviolet absorber

##STR00116##

COMPARATIVE EXAMPLE 1

[0172] The liquid crystal composition of Comparative Example 1 is prepared according to each compound and weight percentage listed in Table 3 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00003 TABLE 3 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 4.5 N-21 Cp 75.34 3CPWO2 9 N-21 Δn 0.1143 3CLWO2 7 N-12 Aε −2.89 2OPWO2 3.5 N-19 K.sub.11 14.1 3PWO2 9 N-19 K.sub.33 15.2 1PWO2 11 N-19 γ.sub.1 69.7 3CPP2 4.5 M-13 VHR(initial) 95.36 3CCP1 8 M-11 VHR (UV) 85.84 3CCV 29 M-1 VHR (Ra) 95.94 3CCV1 8.5 M-1 t.sub.−20° C. 13 4OB(S)O2 4 B-1 τ.sub.off 16.9 5OB(S)O2 2 B-1 Total 100

EXAMPLE 1

[0173] The liquid crystal composition of Example 1 is prepared according to each compound and weight percentage listed in Table 4 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00004 TABLE 4 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 4.5 N-21 Cp 74.34 3CPWO2 9 N-21 Δn 0.1141 3CLWO2 7 N-12 Aε −2.91 2OPWO2 3.5 N-19 K.sub.11 14.4 3PWO2 9 N-19 K.sub.33 15.5 1PWO2 11 N-19 γ.sub.1 69.3 3CPP2 4.5 M-13 VHR (initial) 95.53 3CCP1 8 M-11 VHR (UV) 85.11 3CCV 29 M-1 VHR (Ra) 96.14 3CCV1 8.5 M-1 t.sub.−20° C. 14 4OB(S)OV(2F) 4 F-1 τ.sub.off 16.2 2OB(S)OV(2F) 2 F-1 Total 100

EXAMPLE 2

[0174] The liquid crystal composition of Example 2 is prepared according to each compound and weight percentage listed in Table 5 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00005 TABLE 5 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 4.5 N-21 Cp 74.34 3CPWO2 9 N-21 Δn 0.1141 3CLWO2 7 N-12 Aε −2.91 2OPWO2 3.5 N-19 K.sub.11 14.37 3PWO2 9 N-19 K.sub.33 15.46 1PWO2 11 N-19 γ.sub.1 69.24 3CPP2 4.5 M-13 VHR (initial) 95.51 3CCP1 8 M-11 VHR (UV) 85.17 3CCV 29 M-1 VHR (Ra) 96.13 3CCV1 8.5 M-1 t.sub.−20° C. 15 4OB(S)C(5, V) 2 F-20 τ.sub.off 16.3 4OB(S)OV(2F) 4 F-1 Total 100

[0175] It can be seen from the comparison between Examples 1-2 and Comparative Example 1 that the liquid crystal composition of the present invention has a larger K value (value of K.sub.11 and value of K.sub.33), a smaller rotational viscosity, a higher VHR value (VHR (initial), VHR (UV), VHR (Ra)), a longer low temperature storage time and a shorter response time while maintaining an appropriate clearing point, an appropriate optical anisotropy, and an appropriate absolute value of dielectric anisotropy.

EXAMPLE 3

[0176] The liquid crystal composition of Example 3 is prepared according to each compound and weight percentage listed in Table 6 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00006 TABLE 6 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 3.5 N-21 Cp 77.6 3CPWO2 6.3 N-21 Δn 0.1144 3CLWO2 7 N-12 Aε −2.95 2OPWO2 5.5 N-19 K.sub.11 14.98 3PWO2 6 N-19 K.sub.33 15.99 1PWO2 11 N-19 γ.sub.1 69 3CPP2 4.2 M-13 VHR (initial) 96.16 3CCP1 11 M-11 VHR (UV) 87.24 3CCV 29 M-1 VHR (Ra) 96.89 3CCV1 8.5 M-1 t.sub.−20° C. 19 2OB(O)OV(2F) 4 F-2 τ.sub.off 15.6 4OB(S)OV(2F) 4 F-1 Total 100

EXAMPLE 4

[0177] The liquid crystal composition of Example 4 is prepared according to each compound and weight percentage listed in Table 7 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00007 TABLE 7 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 3.5 N-21 Cp 77.6 3CPWO2 6.3 N-21 Δn 0.1145 3CLWO2 7 N-12 Aε −2.95 2OPWO2 5.5 N-19 K.sub.11 14.97 3PWO2 6 N-19 K.sub.33 15.98 1PWO2 11 N-19 γ.sub.1 69 3CPP2 4.2 M-13 VHR (initial) 96.18 3CCP1 11 M-11 VHR (UV) 87.27 3CCV 29 M-1 VHR (Ra) 96.87 3CCV1 8.5 M-1 t.sub.−20° C. 18 2OB(O)OV(2F) 4 F-2 τ.sub.off 15.7 4OB(O)OV(2F) 4 F-2 Total 100

EXAMPLE 5

[0178] The liquid crystal composition of Example 5 is prepared according to each compound and weight percentage listed in Table 8 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00008 TABLE 8 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 1.5 N-21 Cp 76.6 3CPWO2 3.3 N-21 Δn 0.1142 3CLWO2 5 N-12 Aε −2.95 2OPWO2 5.5 N-19 K.sub.11 15.25 3PWO2 6 N-19 K.sub.33 16.23 1PWO2 11 N-19 γ.sub.1 68.8 3CPP2 7.2 M-13 VHR (initial) 96.89 3CCP1 13 M-11 VHR (UV) 88.13 3CCV 29 M-1 VHR (Ra) 97.54 3CCV1 8.5 M-1 t.sub.−20° C. 19 2OB(S)C(5, V) 5 F-20 τ.sub.off 14.9 4OB(S)OV(2F) 5 F-1 Total 100

EXAMPLE 6

[0179] The liquid crystal composition of Example 6 is prepared according to each compound and weight percentage listed in Table 9 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00009 TABLE 9 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 1.5 N-21 Cp 76.6 3CPWO2 3.3 N-21 Δn 0.1143 3CLWO2 5 N-12 Aε −2.95 2OPWO2 5.5 N-19 K.sub.11 15.25 3PWO2 6 N-19 K.sub.33 16.24 1PWO2 11 N-19 γ.sub.1 68.8 3CPP2 7.2 M-13 VHR (initial) 96.87 3CCP1 13 M-11 VHR (UV) 88.11 3CCV 29 M-1 VHR (Ra) 97.55 3CCV1 8.5 M-1 t.sub.−20° C. 20 4OB(S)O2 5 B-1 τ.sub.off 15 40B(S)C(5, V) 5 F-20 Total 100

COMPARATIVE EXAMPLE 2

[0180] The liquid crystal composition of Comparative Example 2 is prepared according to each compound and weight percentage listed in Table 10 with 0.3 wt. %

##STR00117##

added into the liquid crystal composition of Table 10, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00010 TABLE 10 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 6 N-21 Cp 75.4 3CPWO2 9 N-21 Δn 0.1088 3C1OWO2 12 N-7 Δε −3.76 2CC1OWO2 2.5 N-15 K.sub.11 15.04 3CC1OWO2 14 N-15 K.sub.33 14.56 2C1OWO2 0.5 N-7 γ.sub.1 111.1 3CPP2 6 M-13 VHR (initial) 95.76 3CPP1 3 M-13 VHR (UV) 84.24 3CC2 22 M-1 VHR (Ra) 96.14 4CC3 5.5 M-1 t.sub.−20° .sub.C. 13 5PP1 11.5 M-4 τ.sub.off 22.3 4OB(S)O2 4 B-1 5OB(S)O2 4 B-1 Total 100

EXAMPLE 7

[0181] The liquid crystal composition of Example 7 is prepared according to each compound and weight percentage listed in Table 11 with 0.3 wt. %

##STR00118##

added into the liquid crystal composition of Table 11, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00011 TABLE 11 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 6 N-21 Cp 75.4 3CPWO2 9 N-21 Δn 0.1085 3C1OWO2 12 N-7 Δε −3.73 2CC1OWO2 2.5 N-15 K.sub.11 15.59 3CC1OWO2 14 N-15 K.sub.33 15.04 2C1OWO2 0.5 N-7 γ.sub.1 110.8 3CPP2 6 M-13 VHR (initial) 95.65 3CPP1 3 M-13 VHR (UV) 85.05 3CC2 22 M-1 VHR (Ra) 96.33 4CC3 5.5 M-1 t.sub.−20° C. 16 5PP1 11.5 M-4 τ.sub.off 21.3 4OB(S)OV(2F) 4 F-1 4OB(S)O2 4 B-1 Total 100

EXAMPLE 8

[0182] The liquid crystal composition of Example 8 is prepared according to each compound and weight percentage listed in Table 12 with 0.3 wt. %

##STR00119##

added into the liquid crystal composition of Table 12, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00012 TABLE 12 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 6 N-21 Cp 75.4 3CPW02 9 N-21 Δn 0.1084 3C1OWO2 12 N-7 Δε −3.72 2CC1OWO2 2.5 N-15 K.sub.11 15.58 3CC1OWO2 14 N-15 K.sub.33 15.05 2C1OWO2 0.5 N-7 γ.sub.1 110.7 3CPP2 6 M-13 VHR (initial) 95.67 3CPP1 3 M-13 VHR (UV) 84.98 3CC2 22 M-1 VHR (Ra) 96.36 4CC3 5.5 M-1 t.sub.−20°C 15 5PP1 11.5 M-4 τ.sub.off 21 4OB(O)OV(2F) 4 F-2 4OB(S)C(5,V) 4 F-20 Total 100

[0183] It can be seen from the comparison between Examples 7-8 and Comparative Example 2 that the liquid crystal composition of the present invention has a larger K value (value of K.sub.11 and value of K.sub.33), a smaller rotational viscosity, a higher VHR value (VHR (UV) and VHR (Ra)), a longer low temperature storage time and a shorter response time while maintaining an appropriate clearing point, an appropriate optical anisotropy, an appropriate absolute value of dielectric anisotropy and an appropriate VHR (initial).

EXAMPLE 9

[0184] The liquid crystal composition of Example 9 is prepared according to each compound and weight percentage listed in Table 13 with 0.3 wt. %

##STR00120##

added into the liquid crystal composition of Table 13, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00013 TABLE 13 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 7 N-21 Cp 75.8 3CPWO2 6 N-21 Δn 0.1085 3C1OWO2 8.5 N-7 Δε −3.75 2CC1OWO2 2.5 N-15 K.sub.11 15.63 3CC1OWO2 11 N-15 K.sub.33 15.11 2C1OWO2 1 N-7 γ.sub.1 109.7 3CPP2 6 M-13 VHR (initial) 96.24 3CPP1 6 M-13 VHR (UV) 87.03 3CC2 26 M-1 VHR (Ra) 96.98 4CC3 5.5 M-1 t.sub.−20°C 18 5PP1 11.5 M-4 τ.sub.off 20.6 4OB(S)OV(2F) 3 F-1 2OB(S)OV(2F) 3 F-1 4OB(S)O2 3 B-1 Total 100

EXAMPLE 10

[0185] The liquid crystal composition of Example 10 is prepared according to each compound and weight percentage listed in Table 14 with 0.3 wt. %

##STR00121##

added into the liquid crystal composition of Table 14, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00014 TABLE 14 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 7 N-21 Cp 75.5 3CPWO2 6 N-21 Δn 0.1083 3C1OWO2 8.5 N-7 Δε −3.74 2CC1OWO2 2.5 N-15 K.sub.11 15.63 3CC1OWO2 11 N-15 K.sub.33 15.11 2C1OWO2 1 N-7 γ.sub.1 109.8 3CPP2 6 M-13 VHR (initial) 96.31 3CPP1 6 M-13 VHR (UV) 86.98 3CC2 26 M-1 VHR (Ra) 97.02 4CC3 5.5 M-1 t.sub.−20°C 19 5PP1 11.5 M-4 τ.sub.off 20.2 4OB(S)OV(2F) 3 F-1 4OB(S)O2 3 B-1 4OB(S)C(5,V) 3 F-20 Total 100

EXAMPLE 11

[0186] The liquid crystal composition of Example 11 is prepared according to each compound and weight percentage listed in Table 15 with 0.3 wt. %

##STR00122##

added into the liquid crystal composition of Table 15, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00015 TABLE 15 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 1 N-21 Cp 75.5 3CPWO2 7 N-21 Δn 0.108 3C1OWO2 6.5 N-7 Δε −3.72 2CC1OWO2 2.5 N-15 K.sub.11 15.93 3CC1OWO2 8.5 N-15 K.sub.33 15.31 2C1OWO2 2.5 N-7 γ.sub.1 108.9 3CPP2 9 M-13 VHR (initial) 97.12 3CPP1 7 M-13 VHR (UV) 88.76 3CC2 26 M-1 VHR (Ra) 97.68 4CC3 7.5 M-1 t.sub.−20°C 20 5PP1 11.5 M-4 τ.sub.off 19.4 4OB(O)OV(2F) 4 F-2 2OB(S)C(5,V) 3 F-20 2OB(O)OV(2F) 4 F-2 Total 100

EXAMPLE 12

[0187] The liquid crystal composition of Example 12 is prepared according to each compound and weight percentage listed in Table 16 with 0.3 wt. %

##STR00123##

added into the liquid crystal composition of Table 16, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00016 TABLE 16 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 2CPWO2 1 N-21 Cp 75.5 3CPWO2 7 N-21 Δn 0.1087 3C1OWO2 6.5 N-7 Δε −3.73 2CC1OWO2 2.5 N-15 K.sub.11 15.94 3CC1OWO2 11 N-15 K.sub.33 15.32 3CPP2 6 M-13 γ.sub.1 108.7 3CPP1 3 M-13 VHR (initial) 96.98 3CC2 26 M-1 VHR (UV) 88.75 4CC3 7.5 M-1 VHR (Ra) 97.65 5PP1 11.5 M-4 t.sub.−20°C 20 5OB(S)O2 6 B-1 τ.sub.off 19.5 2OB(O)C(5,V) 6 F-21 4OB(S)C(5,V) 6 F-20 Total 100

COMPARATIVE EXAMPLE 3

[0188] The liquid crystal composition of Comparative Example 3 is prepared according to each compound and weight percentage listed in Table 17 with 0.3 wt. %

##STR00124##

added into the liquid crystal composition of Table 17, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00017 TABLE 17 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CWO2 6 N-2 Cp 75.6 5CWO2 8 N-2 Δn 0.093 2CPWO2 7 N-21 Δε −2.2 3CWO4 4.5 N-2 K.sub.11 12.5 3CCWO2 10 N-9 K.sub.33 14.1 4CCWO2 6 N-9 γ.sub.1 89 3CPO2 10.5 M-2 VHR (initial) 95.56 3CPP2 13 M-13 VHR (UV) 84.44 3CC2 20 M-1 VHR (Ra) 95.84 4CC3 9 M-1 t.sub.−20°C 13 4OB(S)O2 2 B-1 τ.sub.off 20.3 5OB(S)O2 2 B-1 3OB(S)O3 2 B-1 Total 100

EXAMPLE 13

[0189] The liquid crystal composition of Example 13 is prepared according to each compound and weight percentage listed in Table 18 with 0.3 wt. %

##STR00125##

added into the liquid crystal composition of Table 18, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00018 TABLE 18 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CWO2 4.5 N-2 Cp 75.75 5CWO2 8 N-2 Δn 0.0928 2CPWO2 5 N-21 Δε −2.16 3CW04 4.5 N-2 K.sub.11 12.8 3CCWO2 10 N-9 K.sub.33 14.5 4CCWO2 5 N-9 γ.sub.1 88.2 3CPO2 11.5 M-2 VHR (initial) 95.65 3CPP2 12.5 M-13 VHR (UV) 85.12 3CC2 20 M-1 VHR (Ra) 96.15 4CC3 9 M-1 t.sub.−20°C 16 2OB(S)C(5,V) 3 F-20 τ.sub.off 19.3 4OB(S)C(5,V) 4 F-20 4OB(O)C(5,V) 3 F-21 Total 100

[0190] It can be seen from the comparison between Example 13 and Comparative Example 3 that the liquid crystal composition of the present invention has a larger K value (value of K.sub.11 and value of K.sub.33), a smaller rotational viscosity, a higher VHR value (VHR (initial), VHR (UV), VHR (Ra)), a longer low temperature storage time and a shorter response time while maintaining an appropriate clearing point, an appropriate optical anisotropy, and an appropriate absolute value of dielectric anisotropy.

EXAMPLE 14

[0191] The liquid crystal composition of Example 14 is prepared according to each compound and weight percentage listed in Table 19 with 0.3 wt. %

##STR00126##

added into the liquid crystal composition of Table 19, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00019 TABLE 19 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CWO2 4.5 N-2 Cp 75.95 5CWO2 3 N-2 Δn 0.0932 2CPWO2 6 N-21 Δε −2.19 3CWO4 2.5 N-2 K.sub.11 13.2 3CCWO2 10 N-9 K.sub.33 14.9 4CCWO2 1.5 N-9 γ.sub.1 87.3 3CPO2 15 M-2 VHR (initial) 96.16 3CPP2 11.5 M-13 VHR (UV) 87.24 3CC2 20 M-1 VHR (Ra) 96.89 4CC3 14 M-1 t.sub.−20°C 15 2OB(O)C(5,V) 4 F-21 τ.sub.off 18.4 40B(O)C(5,V) 4 F-21 4OB(O)OV(2F) 4 F-2 Total 100

EXAMPLE 15

[0192] The liquid crystal composition of Example 15 is prepared according to each compound and weight percentage listed in Table 20 with 0.3 wt. %

##STR00127##

added into the liquid crystal composition of Table 20, and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00020 TABLE 20 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CWO2 5 N-2 Cp 75.15 2CPWO2 4 N-21 Δn 0.093 3CWO4 4.5 N-2 Δε −2.17 3CCWO2 8 N-9 K.sub.11 13.6 4CCWO2 2.5 N-9 K.sub.33 15.3 3CPO2 12 M-2 γ.sub.1 86.8 3CPP2 11.5 M-13 VHR (initial) 96.06 3CC2 20 M-1 VHR (UV) 87.14 4CC3 16.5 M-1 VHR (Ra) 96.79 4OB(S)OV(2F) 5 F-1 t.sub.−20°C 19 4OB(O)C(5,V) 5 F-21 τ.sub.off 18 4OB(S)O2 6 B-1 Total 100

EXAMPLE 16

[0193] The liquid crystal composition of Example 16 is prepared according to each compound and weight percentage listed in Table 21 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00021 TABLE 21 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CCV 40.5 M-1 Cp 76.15 1PW02 5.5 N-19 Δn 0.1082 2PWO2 6 N-19 Δε −4.31 3CW02 3.5 N-2 K.sub.11 14.85 3CLWO2 9 N-12 K.sub.33 14.28 2OB(S)OV(2F) 6 F-1 γ.sub.1 85.89 4OB(S)OV(2F) 4 F-1 VHR (initial) 95.95 3CPWO2 5 N-21 VHR (UV) 85.87 4CLWO2 7.5 N-12 VHR (Ra) 96.87 3CLWO3 8.5 N-12 t.sub.−20°C 17 3CPP2 4.5 M-13 τ.sub.off 15.5 Total 100

EXAMPLE 17

[0194] The liquid crystal composition of Example 17 is prepared according to each compound and weight percentage listed in Table 22 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00022 TABLE 22 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CCV 40.5 M-1 Cp 76.77 1PWO2 5.5 N-19 Δn 0.1082 2PWO2 6 N-19 Δε −4.32 3CWO2 3.5 N-2 K.sub.11 14.83 3CLWO2 9 N-12 K.sub.33 14.26 2OB(O)OV(2F) 6 F-2 γ.sub.1 85.9 4OB(O)OV(2F) 4 F-2 VHR (initial) 95.98 3CPWO2 5 N-21 VHR (UV) 85.86 4CLWO2 7.5 N-12 VHR (Ra) 96.85 3CLWO3 8.5 N-12 t.sub.−20°C 18 3CPP2 4.5 M-13 τ.sub.off 15.3 Total 100

EXAMPLE 18

[0195] The liquid crystal composition of Example 18 is prepared according to each compound and weight percentage listed in Table 23 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00023 TABLE 23 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CCV 41.5 M-1 Cp 76.27 1PWO2 5.5 N-19 Δn 0.1085 2PWO2 6 N-19 Δε −4.32 3CWO2 2 N-2 K.sub.11 14.96 3CLWO2 8 N-12 K.sub.33 14.38 2OB(S)OV(2F) 6 F-1 γ.sub.1 85.85 4OB(S)OV(2F) 6 F-1 VHR (initial) 96.79 3CPWO2 0.5 N-21 VHR (UV) 87.34 4CLWO2 7.5 N-12 VHR (Ra) 97.32 3CLWO3 8 N-12 t.sub.−20°C 19 3CPP2 9 M-13 τ.sub.off 14.7 Total 100

EXAMPLE 19

[0196] The liquid crystal composition of Example 19 is prepared according to each compound and weight percentage listed in Table 24 and is tested by filling the same between two substrates of a liquid crystal display device.

TABLE-US-00024 TABLE 24 Formulation and test performances of liquid crystal composition Code of Weight Code of Test results for the component percent structure performance parameters 3CCV 41.5 M-1 Cp 76.27 1PWO2 5.5 N-19 Δn 0.1085 2PWO2 6 N-19 Δε −4.33 3CWO2 2 N-2 K.sub.11 14.94 3CLWO2 8 N-12 K.sub.33 14.37 2OB(S)C(5,V) 6 F-20 γ.sub.1 85.86 4OB(S)C(5,V) 6 F-20 VHR (initial) 96.81 3CPWO2 0.5 N-21 VHR (UV) 87.23 4CLWO2 7.5 N-12 VHR (Ra) 97.35 3CLWO3 8 N-12 t.sub.−20°C 20 3CPP2 9 M-13 τ.sub.off 14.8 Total 100

[0197] In conclusion, the liquid crystal composition of the present invention has a larger K value, a smaller rotational viscosity, a higher VHR value, a longer low temperature storage time and a shorter response time while maintaining an appropriate clearing point, an appropriate optical anisotropy, and an appropriate absolute value of dielectric anisotropy, such that the liquid crystal display device comprising the liquid crystal composition has a better contrast, a wider temperature range for application, a faster response speed, a better contrast and a higher reliability.

[0198] The above embodiments are merely illustrative of the technical concepts and features of the present invention, and provided for facilitating the understanding and practice of the present invention by those skilled in the art. However, the protection scope of the invention is not limited thereto. Equivalent variations or modifications made without departing from the spirit and essence of the present invention are intended to be contemplated within the protection scope of the present invention.