LIQUID CRYSTAL MEDIUM

Abstract

The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterised in that it comprises one or more compounds of the formula I in a total concentration of 40%,

##STR00001##

in which the parameters have the meanings indicated in claim 1, and to the use of the liquid-crystalline medium for electro-optical purposes, in particular in liquid-crystal light valves for lighting devices for motor vehicles, and to liquid-crystal light valves which comprise this medium and lighting devices for motor vehicles which contain such liquid-crystal light valves.

Claims

1. Liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterised in that it comprises one or more compounds of the formula I in a total concentration of 40%, ##STR00133## in which R.sup.1 denotes an alkyl or alkoxy radical having 1 to 15 C atoms, where one or more H atoms in these radicals may be replaced by F and, in addition, one or more CH.sub.2 groups may each be replaced, independently of one another, by ##STR00134## CC, CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another, ##STR00135## on each occurrence, identically or differently, denote ##STR00136## L.sup.11 and L.sup.12, independently of one another, denote H or F, X.sup.1 denotes F, Cl, CN, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms.

2. Medium according to claim 1, characterised in that it comprises one or more compounds selected from the group of the compounds of the formulae I-1 to I-5, ##STR00137## in which the parameters have the meanings indicated in claim 1 and L.sup.13 and L.sup.14, independently of one another, denote H or F.

3. Medium according to claim 1, characterised in that it comprises one or more compounds of the formula II ##STR00138## in which R.sup.2 denotes an alkyl or alkoxy radical having 1 to 15 C atoms, where one or more H atoms in these radicals may be replaced by F and, in addition, one or more CH.sub.2 groups may each be replaced, independently of one another, by ##STR00139## CC, CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another, ##STR00140## on each occurrence, identically or differently, denote ##STR00141## L.sup.21 and L.sup.22, independently of one another, denote H or F, X.sup.2 denotes F, Cl, CN, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms, Z.sup.2 denotes CH.sub.2CH.sub.2, CF.sub.2CF.sub.2, COO, trans CHCH, trans CFCF, CH.sub.2O or a single bond.

4. Medium according to claim 3, characterised in that the compounds of the formula II are selected from the group of the compounds of the formulae II-1 to II-14, ##STR00142## ##STR00143## in which R.sup.2 denotes n-alkyl having up to 7 C atoms, L.sup.21 and L.sup.22, independently of one another, denote H or F and X.sup.2 denotes F, Cl, halogenated alkyl or halogenated alkoxy having up to 6 C atoms.

5. Medium according to claim 3, characterised in that the total concentration of the compounds of the formula II is 18% to 50%.

6. Medium according to claim 1, characterised in that it additionally comprises one or more compounds selected from the group of the compounds of the formulae IA and IB, ##STR00144## in which R.sup.1, A.sup.11, A.sup.12, L.sup.11, L.sup.12 and X.sup.1 have the meanings indicated in claim 1 and L.sup.13 and L.sup.14 have the meaning indicated for L.sup.11.

7. Medium according to claim 1, characterised in that it additionally comprises one or more compounds of the formula III, ##STR00145## in which R.sup.3 denotes an alkyl or alkoxy radical having 1 to 15 C atoms, where one or more H atoms in these radicals may be replaced by F and, in addition, one or more CH.sub.2 groups may each be replaced, independently of one another, by ##STR00146## CHCH, O, COO or OCO in such a way that O atoms are not linked directly to one another, ##STR00147## on each occurrence, independently of one another, denote ##STR00148## and Z.sup.3 on each occurrence, independently of one another, denotes CH.sub.2CH.sub.2, COO, trans CHCH, trans CFCF, CH.sub.2O, CC or a single bond, L.sup.31, L.sup.32 denote H or F, X.sup.3 denotes F, Cl, CN, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 C atoms.

8. The medium according to claim 7, characterised in that the one or more compounds of the formula III are selected from the compounds of the formulae III-1 to III-9, ##STR00149## in which R.sup.3, L.sup.31 and L.sup.32 have the meanings indicated in claim 7 and X.sup.3 denotes F, Cl, halogenated alkyl or halogenated alkoxy having to 6 C atoms.

9. A method which comprises including a liquid-crystalline medium according to claim 1 in an electro-optical component.

10. A method according to claim 9 wherein the electro-optical component is a liquid-crystal light valve for lighting devices for motor vehicles or a liquid-crystal display.

11. Electro-optical component comprising a liquid-crystalline medium according to claim 1.

12. Electro-optical component according to claim 11, where the component is a liquid-crystal light valve.

13. Lighting device for motor vehicles containing a liquid-crystal light valve according to claim 12.

14. Liquid-crystal display containing a liquid-crystal light valve according to claim 12.

Description

EXAMPLE M1

[0142]

TABLE-US-00006 BCH-3F.F 7.00% Clearing point [ C.]: 122 BCH-5F.F 10.00% n [589 nm, 20 C.]: 0.0960 CCP-31 10.00% CCP-33 6.00% CCP-3F.F.F 10.00% CCP-5F.F.F 6.00% CBC-53F 6.00% CCQU-2-F 15.00% CCQU-3-F 15.00% CCQU-5-F 15.00%

EXAMPLE M2

[0143]

TABLE-US-00007 CCQU-2-F 15.00% Clearing point [ C.]: 140 CCQU-3-F 15.00% n [589 nm, 20 C.]: 0.0946 CCQU-5-F 15.00% [1 kHz, 20 C.]: 13.8 CCP-3F.F.F 12.00% .sub.1 [mPa .Math. s, 20 C.]: 332 CCP-5F.F.F 6.00% CCGU-3-F 10.00% CCP-3-1 10.00% CBC-53F 6.00% CBC-33F 3.00% CDUQU-3-F 8.00%

EXAMPLE M3

[0144]

TABLE-US-00008 PGP-2-4 2.00% Clearing point [ C.]: 123 PGP-2-5 2.00% n [589 nm, 20 C.]: 0.0955 BCH-5F.F 7.00% CCP-3F.F.F 14.00% CCP-5F.F.F 5.00% CCQU-2-F 14.00% CCQU-3-F 16.00% CCQU-5-F 12.00% CCP-3-1 10.00% ECCP-5F.F 10.00% CBC-33F 4.00% CBC-53F 4.00%

EXAMPLE M4

[0145]

TABLE-US-00009 BCH-5F.F 12.00% Clearing point [ C.]: 140 BCH-3F.F.F 5.00% n [589 nm, 20 C.]: 0.0946 CCP-31 5.00% CCP-33 5.00% CCP-3F.F.F 15.00% CCP-5F.F.F 7.00% CBC-33F 4.00% CBC-53F 4.00% CCQU-2-F 8.00% CCQU-3-F 20.00% CCQU-5-F 15.00%

EXAMPLE M5

[0146]

TABLE-US-00010 BCH-5F.F 10.00% Clearing point [ C.]: 140 CCP-3F.F.F 14.00% n [589 nm, 20 C.]: 0.0946 CCP-5F.F.F 6.00% CCQU-2-F 14.00% CCQU-3-F 16.00% CCQU-5-F 12.00% CCGU-3-F 7.00% CCP-3-1 8.00% ECCP-5F.F 8.00% CBC-33F 2.00% CBC-53F 3.00%

EXAMPLE M6

[0147]

TABLE-US-00011 CCQU-2-F 8.00% Clearing point [ C.]: 140 CCQU-3-F 20.00% n [589 nm, 20 C.]: 0.0946 CCQU-5-F 18.00% CCP-3F.F.F 8.00% CCP-5F.F.F 4.00% CCGU-3-F 10.00% CCP-3-1 5.00% CCP-3-3 3.00% CCOC-3-3 3.00% CCOC-4-3 3.00% BCH-3F.F 8.00% BCH-5F.F 10.00%

EXAMPLE M7

[0148]

TABLE-US-00012 PGP-2-5 2.00% Clearing point [ C.]: 140 CCGU-3-F 8.00% n [589 nm, 20 C.]: 0.0946 BCH-3F.F 2.00% BCH-5F.F 6.00% CCP-3F.F.F 14.00% CCP-5F.F.F 6.00% CCQU-2-F 15.00% CCQU-3-F 18.00% CCQU-5-F 12.00% CCP-3-1 3.00% CCP-3-3 2.00% ECCP-5F.F 6.00% CBC-33F 3.00% CBC-53F 3.00%

EXAMPLE M8

[0149]

TABLE-US-00013 CCQU-2-F 15.00% Clearing point [ C.]: 131 CCQU-3-F 16.00% n [589 nm, 20 C.]: 0.0898 CCQU-5-F 14.00% [1 kHz, 20 C.]: 12.7 CCP-1F.F.F 4.00% .sub.1 [mPa .Math. s, 20 C.]: 294 CCP-2F.F.F 7.00% CCP-3F.F.F 8.00% CCP-5F.F.F 5.00% CCGU-3-F 6.00% CCP-3-1 8.00% CBC-53F 7.00% CBC-33F 4.00% CDUQU-3-F 6.00%

EXAMPLE M9

[0150]

TABLE-US-00014 CCQU-2-F 14.00% Clearing point [ C.]: 130 CCQU-3-F 16.00% n [589 nm, 20 C.]: 0.0814 CCQU-5-F 15.00% [1 kHz, 20 C.]: 11.0 CCP-2F.F.F 7.00% .sub.1 [mPa .Math. s, 20 C.]: 274 CCP-3F.F.F 14.00% CCP-5F.F.F 5.00% CCGU-3-F 8.00% CCP-3-1 8.00% CCOC-3-3 3.00% CCOC-4-3 4.00% CCCG-3-F 6.00%

EXAMPLE M10

[0151]

TABLE-US-00015 CCQU-2-F 14.00% Clearing point [ C.]: 127.9 CCQU-3-F 16.00% n [589 nm, 20 C.]: 0.0810 CCQU-5-F 15.00% [1 kHz, 20 C.]: 11.5 CCP-2F.F.F 7.00% .sub.1 [mPa .Math. s, 20 C.]: 275 CCP-3F.F.F 14.00% CCP-5F.F.F 5.00% CCGU-3-F 8.00% CCP-3-1 8.00% CCOC-3-3 3.00% CCOC-4-3 4.00% CCCQU-3-F 6.00%

EXAMPLE M11

[0152]

TABLE-US-00016 CCQU-2-F 14.00% Clearing point [ C.]: 127.9 CCQU-3-F 16.00% n [589 nm, 20 C.]: 0.0810 CCQU-5-F 15.00% [1 kHz, 20 C.]: 11.6 CCP-2F.F.F 7.00% .sub.1 [mPa .Math. s, 20 C.]: 285 CCP-3F.F.F 14.00% CCP-5F.F.F 5.00% CCGU-3-F 8.00% CCP-3-1 8.00% CCOC-3-3 3.00% CCOC-4-3 4.00% CCCQU-3-OT 6.00%

EXAMPLE M12

[0153]

TABLE-US-00017 CCQU-2-F 14.00% Clearing point [ C.]: 128.8 CCQU-3-F 16.00% n [589 nm, 20 C.]: 0.0796 CCQU-5-F 15.00% CCP-2F.F.F 7.00% CCP-3F.F.F 14.00% CCP-5F.F.F 5.00% CCGU-3-F 6.00% CCP-3-1 8.00% CCOC-3-3 3.00% CCOC-4-3 4.00% CCCQU-3-OT 4.00% CCCQU-3-F 4.00%