Liquid crystal composition and application thereof

Abstract

Disclosed is a liquid crystal composition and use thereof. The liquid crystal composition comprises components a, b and c; wherein component a is selected from one of the compounds represented by formula I; component b is a liquid crystal composition having a dielectric anisotropy of greater than 3; and component c is a liquid crystal composition having a dielectric anisotropy of 3 to 3. The liquid crystal composition has a high contrast ratio property, and has a low change rate at a low temperature, that is, the decrease of contrast ratio at a low temperature (such as 20 C.) is smaller as compared to a normal temperature. The composition has suitable properties with regard to practical applications, including a broader nematic phase range, an appropriate dielectric anisotropy, optical anisotropy and operating voltage, an excellent response time, a high electrical resistivity and voltage holding ratio, a low rotary viscosity, etc. ##STR00001##

Claims

1. A liquid crystal composition, comprising components A, B, and C; wherein said component A is selected from at least one of compounds of formula I; said component B is a liquid crystal compound having a dielectric anisotropy of greater than 3; and said component C is a liquid crystal compound having a dielectric anisotropy of 3 to 3; ##STR00372## wherein in said formula I, R.sub.0 is selected from any one of an H atom, C1-C10 alkyls, fluoro-substituted C1-C10 alkyls, C1-C10 alkoxys, fluoro-substituted C1-C10 alkoxys, C2-C10 alkenyls, fluoro-substituted C2-C10 alkenyls, C3-C8 alkenoxys, and fluoro-substituted C3-C8 alkenoxys; wherein R.sub.1 is selected from H, Cl, F, CN, OCN, OCF.sub.3, CF.sub.3, CHF.sub.2, CH.sub.2F, OCHF.sub.2, SCN, NCS, SF.sub.5, C1-C15 alkyls, C1-C15 alkoxys, C2-C15 alkenyls, or C2-C15 alkenoxys; wherein X.sub.1 and X.sub.2, which are identical or different, are each selected from either of atoms H and fluorine; wherein Z.sub.1 and Z.sub.2, which are identical or different, are each selected from at least one of single bonds, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCH, CC, COO, OOC, CF.sub.2O, OCH.sub.2, CH.sub.2O, OCF.sub.2, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C.sub.2F.sub.4, and CFCF; ##STR00373## is each selected from at least one of single bonds, and the following groups: ##STR00374## wherein both a and b are an integer selected from 0-3; and wherein c is 1 or 2, and a +b+c5.

2. The composition according to claim 1, wherein said liquid crystal composition is composed of components A, B, and C.

3. The composition according to claim 1, wherein a mass ratio of said components A, B, to C is 10-70:10-70:5-70.

4. The composition according to claim 1, wherein the compound as represented by formula I is any one of compounds as represented by I1-I10 and I17 as below: ##STR00375## ##STR00376## wherein in said formulas I1-I10 and I17, the definition of R.sub.1 is the same as that of the R.sub.1 in the formula I in claim 1; wherein in said formulas I1-I10 and I17, each (F) represents F or H; wherein said component B is selected from at least one of compounds as represented by formula II: ##STR00377## wherein in said formula II, the definition of R.sub.4 is the same as that of the R.sub.0 in formula I; wherein the definitions of ##STR00378## are the same as that of ##STR00379## wherein the definitions of X.sub.3 and X.sub.5 are the same as that of the X.sub.1 in said formula I; wherein the definition of X.sub.4 is the same as that of the R.sub.1 in said formula I; wherein e is an integer of 0-3; wherein the compound as represented by the formula II is any one of compounds as represented by formulas II-1 to II-13 as below: ##STR00380## ##STR00381## wherein in said formulas II-1 to II-13, the definitions of R.sub.4 and X.sub.4 are respectively the same as those of the R.sub.4 and X.sub.4 in said formula II; wherein (F) represents F or H; wherein said component C is selected from at least one of compounds as represented by formula III: ##STR00382## wherein in said formula III, the definitions of R.sub.2 and R.sub.3 are the same as that of the R.sub.0 in the formula I in claim 1; wherein the definition of ##STR00383## is the same as that of the ##STR00384## in the formula I in claim 1; wherein d is an integer of 0-3; wherein said compound as represented by the formula III is any one of compounds as represented by formulas III-1 to III-10 as below: ##STR00385## wherein in said formulas III-1 to III-10, the definitions of R.sub.2 and R.sub.3 are both the same as that of the R.sub.0 in the formula I in claim 1; wherein (F) represents F or H.

5. The composition according to claim 1, wherein said liquid crystal composition further comprises at least one of compounds as represented by formulas IV and V; ##STR00386## wherein in said formulas IV and V, the definitions of R.sub.5 and R.sub.6 are the same as that of the R.sub.0 in the formula I in claim 1; wherein the definition of R.sub.7 is the same as that of the R.sub.1 in the formula I in claim 1; wherein the definitions of ##STR00387## are the same as that of the ##STR00388## in the formula I in claim 1; wherein Z.sub.3 is selected from any least one of CH.sub.2CH.sub.2, CHCH, CC, COO, OOC, OCH.sub.2, CH.sub.2O, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C.sub.2F.sub.4, and CFCF; wherein the definition of X.sub.6 is the same as that of the X.sub.1 in the formula I in claim 1; wherein the definition of X.sub.7 is the same as that of the X.sub.4 in the formula I in claim 4; and wherein f, g, h, and i are all integers of 0-3.

6. The composition according to claim 5, wherein a mass ratio of said compound as represented by the formula IV to said compound as represented by the formula V is 0-30:0-40; wherein a mass ratio of said compound as represented by the formula IV to said compound as represented by the formula III is 0-30:5-70; and wherein neither a mass of the compound as represented by formula IV nor that of the compound as represented by formula V is 0.

7. The composition according to claim 5, wherein said compound as represented by the formula IV is any one of compounds as represented by formulas IV-1 to IV-5 as below: ##STR00389## wherein in said formulas IV-1 to IV-5, the definitions of R.sub.5 and R.sub.6 are both the same as that of the R.sub.0 in the formula I in claim 1; wherein (F) represents F or H; wherein said compound as represented by the formula V is any one of compounds as represented by formulas V-1 to V-17 as below: ##STR00390## ##STR00391## wherein in said formulas V-1 to V-17, the definition of R.sub.7 is the same as that of the R.sub.1 in the formula I in claim 1; and wherein (F) represents F or H.

8. A liquid crystal display element or liquid crystal display comprising a liquid crystal composition, comprising components A, B, and C; wherein said component A is selected from at least one of compounds of formula I; said component B is a liquid crystal compound having a dielectric anisotropy of greater than 3; and said component C is a liquid crystal compound having a dielectric anisotropy of 3 to 3; ##STR00392## wherein in said formula I, R.sub.0 is selected from any one of an H atom, C1-C10 alkyls, fluoro-substituted C1-C10 alkyls, C1-C10 alkoxys, fluoro-substituted C1-C10 alkoxys, C2-C10 alkenyls, fluoro-substituted C2-C10 alkenyls, C3-C8 alkenoxys, and fluoro-substituted C3-C8 alkenoxys; wherein R.sub.1 is selected from H, Cl, F, CN, OCN, OCF.sub.3, CF.sub.3, CHF.sub.2, CH.sub.2F, OCHF.sub.2, SCN, NCS, SF.sub.5, C1-C15 alkyls, C1-C15 alkoxys, C2-C15 alkenyls, or C2-C15 alkenoxys; wherein X.sub.1 and X.sub.2, which are identical or different, are each selected from either of atoms H and fluorine; wherein Z.sub.1 and Z.sub.2, which are identical or different, are each selected from at least one of single bonds, CH.sub.2CH.sub.2, (CH.sub.2).sub.4, CHCH, CC, COO, OOC, CF.sub.2O, OCH.sub.2, CH.sub.2O, OCF.sub.2, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C.sub.2F.sub.4, and CFCF; ##STR00393## is each selected from at least one of single bonds, and the following groups: ##STR00394## wherein both a and b are an integer selected from 0-3; and c is 1 or 2, and a+b+c5, wherein the liquid crystal display element or liquid crystal display is an active matrix display element or display or a passive matrix display element or display.

9. The liquid crystal display element or liquid crystal display according to claim 8, wherein the liquid crystal display element or liquid crystal display is an active matrix liquid crystal display element or display.

10. The liquid crystal display element or liquid crystal display according to claim 8, wherein the active matrix display element or display is a TN-TFT or IPS-TFT liquid crystal display element or display.

11. The composition according to claim 4, wherein said liquid crystal composition further comprises at least one of compounds as represented by formulas IV and V; ##STR00395## wherein in said formulas IV and V, the definitions of R.sub.5 and R.sub.6 are the same as that of the R.sub.0 in the formula I in claim 1; wherein the definition of R.sub.7 is the same as that of the R.sub.1 in the formula I in claim 1; wherein the definitions of ##STR00396## are the same as that of the ##STR00397## in the formula I in claim 1; wherein Z.sub.3 is selected from any least one of CH.sub.2CH.sub.2, CHCH, CC, COO, OOC, OCH.sub.2, CH.sub.2O, CF.sub.2CH.sub.2, CH.sub.2CF.sub.2, C.sub.2F.sub.4, and CFCF; wherein the definition of X.sub.6 is the same as that of the X.sub.1 in the formula I in claim 1; wherein the definition of X.sub.7 is the same as that of the X.sub.4 in the formula I in claim 4; and wherein f, g, h, and i are all integers of 0-3.

12. The composition according to claim 11, wherein said liquid crystal composition is composed of compounds as represented by formulas I to V, and wherein the compounds represented by formulas I to V are in a mass ratio of 10-70:10-70:5-70:0-30:0-40, wherein neither a mass of the compound as represented by formula IV nor that of the compound as represented by formula V is 0.

13. The composition of claim 1, wherein when R.sub.1 is C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, CH.sub.2F, or C2-C15 alkenoxy, at least one CH.sub.2 is CHCH, CC, COO, OOC, cyclobutyl, cyclopentyl, O, or S; and wherein when at least one CH.sub.2 is CHCH, CC, COO, OOC, cyclobutyl, cyclopentyl, O, or S, oxygen atoms are not directly connected.

14. The composition of claim 1, wherein when R.sub.1 is CHF.sub.2, CH.sub.2F, OCHF.sub.2, C1-C15 alkyls, C1-C15 alkoxys, C2-C15 alkenyls, or C2-C15 alkenoxys, at least one hydrogen of R.sub.1 is substituted with fluorine or chlorine.

15. The liquid crystal display element or liquid crystal display comprising a liquid crystal composition of claim 8, wherein when R.sub.1 is C1-C15 alkyl, C1-C15 alkoxy, C2-C15 alkenyl, CH.sub.2F, or C2-C15 alkenoxy, at least one CH.sub.2 is CHCH, CC, COO, OOC, cyclobutyl, cyclopentyl, O, or S; and wherein when at least one CH.sub.2 is CHCH, CC, COO, OOC, cyclobutyl, cyclopentyl, O, or S, oxygen atoms are not directly connected.

16. The liquid crystal display element or liquid crystal display comprising a liquid crystal composition of claim 8, wherein when R.sub.1 is CHF.sub.2, CH.sub.2F, OCHF.sub.2, C1-C15 alkyls, C1-C15 alkoxys, C2-C15 alkenyls, or C2-C15 alkenoxys, at least one hydrogen of R.sub.1 is substituted with fluorine or chlorine.

Description

PARTICULAR EMBODIMENTS

(1) The present invention is further illustrated in combination with particular embodiments below, but the following embodiments are examples of the present invention, the present invention being not limited to the following embodiments. Without departing from the subject matter or scope of the present invention, liquid crystal compositions with different threshold values, clearing points and birefringence properties may be obtained by adjustment, modification or improvement of the contents of various components within the liquid crystal composition of the present invention, which would be obvious to a person skilled in the art. If not particularly specified, said methods are all conventional methods.

(2) The various components used in the following embodiments can all be synthesized by commonly known methods or obtained by commercial approaches. The synthesis techniques are conventional, and the obtained various liquid crystal compounds are tested to be complied with standards of electronic compounds.

(3) Liquid crystal compositions are prepared at the ratios, as specified in the following embodiments, of the various liquid crystal compositions. The preparation of said liquid crystal compositions is performed according to conventional methods in the art, e.g., by means of heating, ultrasound, suspension, etc., at the specified ratios.

(4) The liquid crystal compositions provided in the following embodiments are prepared and studied. In addition, they are filled between two substrates of a liquid crystal display for a performance test, and the composition of each liquid crystal composition and test results of performance parameters thereof are shown as below.

(5) The percentages in the present invention are weight percentages, and the temperature is degree Celsius ( C.). Unless otherwise specified, the particular meanings of other symbols and test conditions are as follows:

(6) Cp ( C.) represents the clearing point of a liquid crystal.

(7) n represents the optical anisotropy, no is the refractive index of ordinary light, ne is the refractive index of extraordinary light, and the test conditions are 589 nm and 25 C.

(8) is the dielectric anisotropy, =/, wherein / is a dielectric constant parallel to the molecular axis, is a dielectric constant perpendicular to the molecular axis; and the test conditions are 25 C., 1 KHz, HP4284A, and a 4.0 micronmeter TN left-handed cell.

(9) V.sub.10 is an optical threshold voltage of a liquid crystal [v], V.sub.90 is a saturation voltage value of a liquid crystal [v], and the test conditions are a 4.0 micronmeter TN left-handed box, and 25 C.

(10) The computational method for the change rate of contrast ratio Cr % is: (contrast ratio at normal temperature 25 C.contrast ratio at a low temperature20 C.)/contrast ratio at normal temperature 25 C.*100%.

(11) Change rates of contrast ratio measured in the following embodiments are all calculated based on the contrast ratios at temperatures of normal temperature 25 C. and a low temperature 20 C., but not limited to these temperatures, temperatures within a range of from 60 C. to 40 C. all falling within the encompassed scope of the present patent. The test instrument is DMS 501 in all the cases.

(12) The chiral agent used in each of the following examples is

(13) ##STR00096##

Example 1

(14) The liquid crystal composition a provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(15) ##STR00097## subordinate to formula I8

(16) ##STR00098## subordinate to formula I8

(17) ##STR00099## subordinate to formula II-1

(18) ##STR00100## subordinate to formula II-4

(19) ##STR00101## subordinate to formula III-3

(20) ##STR00102## subordinate to formula III-1

(21) ##STR00103## subordinate to formula II-3

(22) ##STR00104## subordinate to formula V-6

(23) ##STR00105## subordinate to formula II-6

(24) ##STR00106## and a chiral agent 0.18

(25) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 95 C.; : 10.5; V.sub.10[v]: 1.43; and Cr %: 8%.

(26) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 1

(27) ##STR00107##

(28) In example 1, is replaced by the same percent

(29) by weight of is

(30) ##STR00108##
replaced by the same percent by weight of

(31) ##STR00109##
and the other components are not changed to obtain a liquid crystal composition; and the properties of the composition are as shown below: n: 0.111; cp [ C.]: 95 C.; : 10.3; V.sub.10[v]: 1.46; and Cr %: 40%.

(32) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of the liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 2

(33) The liquid crystal composition b provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I11

(34) ##STR00110## subordinate to formula I36

(35) ##STR00111## subordinate to formula II-1

(36) ##STR00112## subordinate to formula II-1

(37) ##STR00113## subordinate to formula II-1

(38) ##STR00114## subordinate to formula II-1

(39) ##STR00115## subordinate to formula II-1

(40) ##STR00116## subordinate to formula II-4

(41) ##STR00117## subordinate to formula III-1

(42) ##STR00118## subordinate to formula V6

(43) ##STR00119## a chiral agent 0.13 The properties of the composition are as shown below: n: 0.100; cp [ C.]: 97 C.; : 10.5; V.sub.10[v]: 1.43; and Cr %: 12%.

(44) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 2

(45) In example 2,

(46) ##STR00120##
is replaced by the same percent by weight of

(47) ##STR00121##
is replaced by the same percent by weight of

(48) ##STR00122##
and the other components are not changed to obtain a liquid crystal composition; and

(49) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 97 C.; : 10.5; V.sub.10[v]: 1.42; and Cr %: 42%.

(50) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 3

(51) The liquid crystal composition c provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(52) ##STR00123## subordinate to formula I8

(53) ##STR00124## subordinate to formula I8

(54) ##STR00125## subordinate to formula II-1

(55) ##STR00126## subordinate to formula II-1

(56) ##STR00127## subordinate to formula II-4

(57) ##STR00128## subordinate to formula II-4

(58) ##STR00129## subordinate to formula II-3

(59) ##STR00130## subordinate to formula III-3

(60) ##STR00131## subordinate to formula III-1

(61) ##STR00132## subordinate to formula V-6

(62) ##STR00133## subordinate to formula V-6

(63) ##STR00134##
a chiral agent 0.25

(64) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 95 C.; : 11.2; V.sub.10[v]: 1.40; and Cr %: 15%.

(65) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 4

(66) The liquid crystal composition d provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I11

(67) ##STR00135## subordinate to formula I14

(68) ##STR00136## subordinate to formula II-1

(69) ##STR00137## subordinate to formula II-1

(70) ##STR00138## subordinate to formula II-1

(71) ##STR00139## subordinate to formula II-1

(72) ##STR00140## subordinate to formula II-3

(73) ##STR00141## subordinate to formula II-4

(74) ##STR00142## subordinate to formula III-1

(75) ##STR00143## subordinate to formula V-6

(76) ##STR00144##

(77) a chiral agent 0.18

(78) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 91 C.; : 11.2; V.sub.10[v]: 1.39; and Cr %: 14%.

(79) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 5

(80) The liquid crystal composition e provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(81) ##STR00145## subordinate to formula I8

(82) ##STR00146## subordinate to formula II-1

(83) ##STR00147## subordinate to formula II-1

(84) ##STR00148## subordinate to formula II-1

(85) ##STR00149## subordinate to formula II-4

(86) ##STR00150## subordinate to formula II-3

(87) ##STR00151## subordinate to formula III-3

(88) ##STR00152## subordinate to formula III-4

(89) ##STR00153## subordinate to formula III-1

(90) ##STR00154##

(91) a chiral agent 0.31

(92) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 90 C.; : 10.4; V.sub.10[v]: 1.50; and Cr %: 17%.

(93) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 3

(94) In example 5,

(95) ##STR00155##
is replaced by the same percent by weight of

(96) ##STR00156##
is replaced by the same percent by weight of

(97) ##STR00157##
and the other components are not changed to obtain a liquid crystal composition; and

(98) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 90 C.; : 10.4; V.sub.10[v]: 1.50; and Cr %: 35%.

(99) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 6

(100) The liquid crystal composition f provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(101) ##STR00158## subordinate to formula I8

(102) ##STR00159## subordinate to formula I8

(103) ##STR00160## subordinate to formula II-7

(104) ##STR00161## subordinate to formula II-1

(105) ##STR00162## subordinate to formula II-3

(106) ##STR00163## subordinate to formula I5

(107) ##STR00164## subordinate to formula IV-1

(108) ##STR00165## subordinate to formula V-6

(109) ##STR00166## subordinate to formula V-6

(110) ##STR00167## subordinate to formula V-6

(111) ##STR00168## subordinate to formula II-11

(112) ##STR00169## subordinate to formula III-3

(113) ##STR00170## subordinate to formula III-1

(114) ##STR00171## a chiral agent 0.27

(115) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 95 C.; : 10.4; V.sub.10[v]: 1.49; and Cr %: 10%.

(116) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 7

(117) The liquid crystal composition g provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I11

(118) ##STR00172## subordinate to formula I36

(119) ##STR00173## subordinate to formula II-1

(120) ##STR00174## subordinate to formula II-1

(121) ##STR00175## subordinate to formula II-1

(122) ##STR00176## subordinate to formula II-1

(123) ##STR00177## subordinate to formula II-4

(124) ##STR00178## subordinate to formula II-4

(125) ##STR00179## subordinate to formula II-4

(126) ##STR00180## subordinate to formula II-3

(127) ##STR00181## subordinate to formula III-3

(128) ##STR00182## subordinate to formula III-1

(129) ##STR00183## subordinate to formula V-6

(130) ##STR00184## a chiral agent 0.28

(131) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 90 C.; : 10.5; V.sub.10[v]: 1.49; and Cr %: 11%.

(132) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 8

(133) The liquid crystal composition h provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(134) ##STR00185## subordinate to formula II-1

(135) ##STR00186## subordinate to formula II-1

(136) ##STR00187## subordinate to formula II-7

(137) ##STR00188## subordinate to formula II-6

(138) ##STR00189## subordinate to formula II-5

(139) ##STR00190## subordinate to formula II-5

(140) ##STR00191## subordinate to formula II-5

(141) ##STR00192## subordinate to formula III-4

(142) ##STR00193## subordinate to formula III-3

(143) ##STR00194## subordinate to formula III-2

(144) ##STR00195## subordinate to formula III-1

(145) ##STR00196## a chiral agent 0.16

(146) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 100 C.; : 7.7; V.sub.10[v]: 1.73; and Cr %: 22%.

(147) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 4

(148) 10 parts by weight of the

(149) ##STR00197##
in example 8 is replaced by 6 parts by weight of

(150) ##STR00198##
and the part by weight of

(151) ##STR00199##
is changed to 8 to obtain a liquid crystal composition;

(152) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 100 C.; : 7.7; V.sub.10[v]: 1.73; and Cr %: 50%.

(153) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 9

(154) The liquid crystal composition i provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I8

(155) ##STR00200## subordinate to formula II-1

(156) ##STR00201## subordinate to formula II-1

(157) ##STR00202## subordinate to formula II-4

(158) ##STR00203## subordinate to formula II-3

(159) ##STR00204## subordinate to formula II-1

(160) ##STR00205## subordinate to formula V-6

(161) ##STR00206## subordinate to formula V-6

(162) ##STR00207## subordinate to formula III-2

(163) ##STR00208## subordinate to formula III-1

(164) ##STR00209## subordinate to formula III-3

(165) ##STR00210## a chiral agent 0.19

(166) The properties of the composition are as shown below: n: 0.095; cp [ C.]: 110 C.; : 5.6; V.sub.10[v]: 2.05; and Cr %: 20%.

(167) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 5

(168) The

(169) ##STR00211##
in example 9 is replaced by the same part by weight of

(170) ##STR00212##
to obtain a liquid crystal composition;

(171) The properties of the composition are as shown below: n: 0.095; cp [ C.]: 110 C.; : 5.6; V.sub.10[v]: 2.05; and Cr %: 50%.

(172) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 10

(173) The liquid crystal composition j provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(174) ##STR00213## subordinate to formula II-1

(175) ##STR00214## subordinate to formula II-1

(176) ##STR00215## subordinate to formula II-1

(177) ##STR00216## subordinate to formula II-1

(178) ##STR00217## subordinate to formula II-1

(179) ##STR00218## subordinate to formula II-1

(180) ##STR00219## subordinate to formula II-1

(181) ##STR00220## subordinate to formula II-4

(182) ##STR00221## subordinate to formula II-4

(183) ##STR00222## subordinate to formula V-2

(184) ##STR00223## subordinate to formula III-10

(185) ##STR00224## subordinate to formula II-5

(186) ##STR00225## a chiral agent 0.34

(187) The properties of the composition are as shown below: n: 0.089; cp [ C.]: 89 C.; : 9.4; V.sub.10[v]: 1.51; and Cr %: 19%.

(188) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 6

(189) The

(190) ##STR00226##
in example 10 is replaced by the same part by weight of

(191) ##STR00227##
to obtain a liquid crystal composition;

(192) The properties of the composition are as shown below: n: 0.089; cp [ C.]: 89 C.; : 9.4; V.sub.10[v]: 1.51; and Cr %: 50%.

(193) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 11

(194) The liquid crystal composition k provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(195) ##STR00228## subordinate to formula II-4

(196) ##STR00229## subordinate to formula II-3

(197) ##STR00230## subordinate to formula II-3

(198) ##STR00231## subordinate to formula II-5

(199) ##STR00232## subordinate to formula II-5

(200) ##STR00233## subordinate to formula III-1

(201) ##STR00234## subordinate to formula III-1

(202) ##STR00235## a chiral agent 0.16

(203) The properties of the composition are as shown below: n: 0.115; cp [ C.]: 74 C.; : 6.8; V.sub.10[v]: 2.0; and Cr %: 20%.

(204) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 7

(205) 11.5 parts by weight of the

(206) ##STR00236##
in example 11 is replaced by 8.5 parts by weight of

(207) ##STR00237##
and the part by weight of

(208) ##STR00238##
is changed to 13 to obtain a liquid crystal composition;

(209) The properties of the composition are as shown below: n: 0.115; cp [ C.]: 74 C.; : 6.8; V.sub.10[v]: 2.0; and Cr %: 52%.

(210) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 12

(211) The liquid crystal composition 1 provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I8

(212) ##STR00239## subordinate to formula II-1

(213) ##STR00240## subordinate to formula II-1

(214) ##STR00241## subordinate to formula II-1

(215) ##STR00242## subordinate to formula II-4

(216) ##STR00243## subordinate to formula II-1

(217) ##STR00244## subordinate to formula II-5

(218) ##STR00245## subordinate to formula II-5

(219) ##STR00246## subordinate to formula II-5

(220) ##STR00247## subordinate to formula III-2

(221) ##STR00248## subordinate to formula III-1

(222) ##STR00249## subordinate to formula III-3

(223) ##STR00250## a chiral agent 0.45

(224) The properties of the composition are as shown below: n: 0.100; cp [ C.]: 100 C.; : 7.7; V.sub.10[v]: 1.73; and Cr %: 21%.

(225) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 13

(226) The liquid crystal composition m provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(227) ##STR00251## subordinate to formula II-4

(228) ##STR00252## subordinate to formula II-3

(229) ##STR00253## subordinate to formula II-3

(230) ##STR00254## subordinate to formula II-3

(231) ##STR00255## subordinate to formula II-4

(232) ##STR00256## subordinate to formula II-4

(233) ##STR00257## subordinate to formula II-4

(234) ##STR00258## subordinate to formula III-3

(235) ##STR00259## subordinate to formula III-1

(236) ##STR00260## subordinate to formula III-1

(237) ##STR00261## a chiral agent 0.17

(238) The properties of the composition are as shown below: n: 0.132; cp [ C.]: 75 C.; : 5.0; V.sub.10[v]: 2.3; and Cr %: 15%.

(239) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 8

(240) The

(241) ##STR00262##
in example 13 is replaced by the same part by weight of

(242) ##STR00263##
to obtain a liquid crystal composition;

(243) The properties of the composition are as shown below: n: 0.128; cp [ C.]: 75 C.; : 5.0; V.sub.10[v]: 2.3; and Cr %: 53%.

(244) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 14

(245) The liquid crystal composition n provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(246) ##STR00264## subordinate to formula I8

(247) ##STR00265## subordinate to formula I17

(248) ##STR00266## subordinate to formula II-9

(249) ##STR00267## subordinate to formula II-9

(250) ##STR00268## subordinate to formula II-1

(251) ##STR00269## subordinate to formula V-6

(252) ##STR00270## subordinate to formula II-5

(253) ##STR00271## subordinate to formula IV-2

(254) ##STR00272## subordinate to formula III-1

(255) ##STR00273## subordinate to formula III-1

(256) ##STR00274## a chiral agent 0.51

(257) The properties of the composition are as shown below: n: 0.088; cp [ C.]: 87 C.; : 8.7; Cr %: 6%.

(258) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in IPS mode displays.

Example 15

(259) The liquid crystal composition o provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I8

(260) ##STR00275## subordinate to formula I5

(261) ##STR00276## subordinate to formula I5

(262) ##STR00277## subordinate to formula I6

(263) ##STR00278## subordinate to formula II-1

(264) ##STR00279## subordinate to formula V-6

(265) ##STR00280## subordinate to formula II-5

(266) ##STR00281## subordinate to formula II-5

(267) ##STR00282## subordinate to formula III-1

(268) ##STR00283## subordinate to formula III-1

(269) ##STR00284## a chiral agent 0.52

(270) The properties of the composition are as shown below: n: 0.0910; cp [ C.]: 100 C.; : 7.7; Cr %: 8%.

(271) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in IPS mode displays.

Example 16

(272) The liquid crystal composition p provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I8

(273) ##STR00285## subordinate to formula I1

(274) ##STR00286## subordinate to formula I17

(275) ##STR00287## subordinate to formula I17

(276) ##STR00288## subordinate to formula I5

(277) ##STR00289## subordinate to formula II-11

(278) ##STR00290## subordinate to formula II-5

(279) ##STR00291## subordinate to formula II-1

(280) ##STR00292## subordinate to formula III-4

(281) ##STR00293## subordinate to formula III-3

(282) ##STR00294## subordinate to formula III-1

(283) ##STR00295## subordinate to formula III-1

(284) ##STR00296##

(285) The properties of the composition are as shown below: n: 0.930; cp [ C.]: 87 C.; : 9.9; Cr %: 0%.

(286) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in IPS mode displays.

Example 17

(287) The liquid crystal composition q provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I11

(288) ##STR00297## subordinate to formula I14

(289) ##STR00298## subordinate to formula II-3

(290) ##STR00299## subordinate to formula II-3

(291) ##STR00300## subordinate to formula III-4

(292) ##STR00301## subordinate to formula III-3

(293) ##STR00302## subordinate to formula III-2

(294) ##STR00303## subordinate to formula III-1

(295) ##STR00304## subordinate to formula III-1

(296) ##STR00305##

(297) The properties of the composition are as shown below: n: 0.101; cp [ C.]: 83 C.; : 3.0; Cr %: 12%.

(298) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in IPS mode displays.

Example 18

(299) The liquid crystal composition r provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I8

(300) ##STR00306## subordinate to formula I5

(301) ##STR00307## subordinate to formula I5

(302) ##STR00308## subordinate to formula I6

(303) ##STR00309## subordinate to formula I8

(304) ##STR00310## subordinate to formula I3

(305) ##STR00311## subordinate to formula II-13

(306) ##STR00312## subordinate to formula I14

(307) ##STR00313## subordinate to formula III-1

(308) ##STR00314## subordinate to formula I1

(309) ##STR00315##

(310) The properties of the composition are as shown below: n: 0.122; cp [ C.]: 72 C.; : 13.1; Cr %: 5%.

(311) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 19

(312) The liquid crystal composition s provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I-1

(313) ##STR00316## subordinate to formula I-1

(314) ##STR00317## subordinate to formula I8

(315) ##STR00318## subordinate to formula II-1

(316) ##STR00319## subordinate to formula II-1

(317) ##STR00320## subordinate to formula II-1

(318) ##STR00321## subordinate to formula II-4

(319) ##STR00322## subordinate to formula II-4

(320) ##STR00323## subordinate to formula II-4

(321) ##STR00324## subordinate to formula II-3

(322) ##STR00325## subordinate to formula III-3

(323) ##STR00326## subordinate to formula III-1

(324) ##STR00327## subordinate to formula V-6

(325) ##STR00328##

(326) The properties of the composition are as shown below: n: 0.110; cp [ C.]: 90 C.; : 11.5; V.sub.10[v]: 1.49; and Cr %: 9%.

(327) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 20

(328) The liquid crystal composition t provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I-1

(329) ##STR00329## subordinate to formula I-36

(330) ##STR00330## subordinate to formula I8

(331) ##STR00331## subordinate to formula II-1

(332) ##STR00332## subordinate to formula II-1

(333) ##STR00333## subordinate to formula II-1

(334) ##STR00334## subordinate to formula II-4

(335) ##STR00335## subordinate to formula II-4

(336) ##STR00336## subordinate to formula II-4

(337) ##STR00337## subordinate to formula I11

(338) ##STR00338## subordinate to formula III-1

(339) ##STR00339## subordinate to formula III-1

(340) ##STR00340## subordinate to formula I-14

(341) ##STR00341##

(342) The properties of the composition are as shown below: n: 0.140; cp [ C.]: 85 C.; : 12.5; V.sub.10[v]: 1.40; and Cr %: 9%.

(343) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Example 21

(344) The liquid crystal composition u provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(345) ##STR00342## subordinate to formula II-4

(346) ##STR00343## subordinate to formula II-4

(347) ##STR00344## subordinate to formula II-1

(348) ##STR00345## subordinate to formula II-1

(349) ##STR00346## subordinate to formula II-1

(350) ##STR00347## subordinate to formula II-5

(351) ##STR00348## subordinate to formula III-1

(352) ##STR00349##

(353) The properties of the composition are as shown below: n: 0.094; cp [ C.]: 83 C.; : 8.5; V.sub.10[v]: 1.51; and Cr %: 9%.

(354) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 9

(355) In example 21,

(356) ##STR00350##
is replaced by the same percent by weight of

(357) ##STR00351##
and the other components are not changed to obtain a liquid crystal composition; and

(358) The properties of the composition are as shown below: n: 0.103; cp [ C.]: 88 C.; : 8.0; V.sub.10[v]: 1.61; and Cr %: 35.

(359) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 22

(360) The liquid crystal composition v provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(361) ##STR00352## subordinate to formula I8

(362) ##STR00353## subordinate to formula I5

(363) ##STR00354## subordinate to formula II-4

(364) ##STR00355## subordinate to formula II-4

(365) ##STR00356## subordinate to formula II-1

(366) ##STR00357## subordinate to formula III-1

(367) ##STR00358##

(368) The properties of the composition are as shown below: n: 0.093; cp [ C.]: 54 C.; : 9.9; V.sub.10[v]: 1.1; and Cr %: 7%.

(369) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 10

(370) In example 22,

(371) ##STR00359##
is replaced by the same percent by weight of

(372) ##STR00360##
is replaced by the same percent by weight of

(373) ##STR00361##
is replaced by the same percent by weight of

(374) ##STR00362##
and the other components are not changed to obtain a liquid crystal composition; and

(375) The properties of the composition are as shown below: n: 0.115; cp [ C.]: 65 C.; : 7.9; V.sub.10[v]: 1.4; and Cr %: 31%.

(376) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

Example 23

(377) The liquid crystal composition w provided by the present invention is obtained by uniformly mixing various components in the following parts by weight: subordinate to formula I1

(378) ##STR00363## subordinate to formula I8

(379) ##STR00364## subordinate to formula II-4

(380) ##STR00365## subordinate to formula II-4

(381) ##STR00366## subordinate to formula II-1

(382) ##STR00367## subordinate to formula III-1

(383) ##STR00368##

(384) The properties of the composition are as shown below: n: 0.088; cp [ C.]: 59 C.; : 8.2; V.sub.10[v]: 1.4; and Cr %: 31%.

(385) It can be seen from the above that the liquid crystal composition has an advantageous refractive index, an appropriate dielectric constant, and a very good change rate of normal temperature-low temperature contrast ratio (namely, the change rate is smaller), and is very suitable for use in TN mode displays.

Comparative Example 11

(386) In example 23,

(387) ##STR00369##
is replaced by the same percent by weight of

(388) ##STR00370##
is replaced by the same percent by weight of

(389) ##STR00371##
and the other components are not changed to obtain a liquid crystal composition; and

(390) The properties of the composition are as shown below: n: 0.103; cp [ C.]: 65 C.; : 6.0; V.sub.10[v]: 1.6; and Cr %: 42%.

(391) It can be seen from the above that the change rate of normal temperature-low temperature contrast ratio of this liquid crystal composition is poorer (namely, the change rate is larger), and therefore there is no advantage with regard to a TN mode display requiring a higher change rate of contrast ratio.

INDUSTRIAL APPLICATIONS

(392) The liquid crystal composition provided by the present invention has a property of a high contrast ratio, and especially has a low change rate at a low temperature, that is, the decrease of contrast ratio at a low temperature (such as 20 C.) is smaller as compared to at normal temperature. Furthermore, the composition has suitable properties with regard to practical applications, such as a broader nematic phase range, an appropriate dielectric anisotropy (), optical anisotropy (n) and operating voltage, an excellent response time, a high electrical resistivity and voltage holding ratio, a low rotary viscosity. By adjustment of the contents of the various components, the nematic phase liquid crystal compositions provided by the present invention may have various threshold voltages and birefringence properties, and can be manufactured as various systems commonly used for clients, for the convenience of use at different liquid crystal cell thicknesses and different driving voltages.