Liquid-crystalline medium and high-frequency components comprising same

Abstract

The present invention relates to liquid-crystalline media comprising one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00001##
in which the parameters R.sup.1-R.sup.3, Z.sup.21, Z.sup.31, Z.sup.32 and rings A.sup.11, A.sup.12, A.sup.13, A.sup.21, A.sup.22, A.sup.31, and A.sup.32 are as defined herein, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

Claims

1. A liquid-crystal medium comprising: one or more compounds selected from formulae I-3a to I-3d: ##STR00224## in which R.sup.1 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms; one or more compounds selected from formula II: ##STR00225## in which R.sup.2 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, Z.sup.21 denotes trans-CHCH, trans-CFCF or CC, and ##STR00226## independently of one another, denote ##STR00227## and one or more compounds selected from formula III-1b: ##STR00228## in which R.sup.3 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, wherein the amount of compounds of formula III-1b in said medium is in the range from 5 to 45 wt. %, wherein the liquid-crystal medium has a clearing point of 90 C. or more, wherein the medium has a material quality, , of 20 or more at 20 C. and 19 GHz, and wherein the total concentration of compounds of formulae I-3a to I-3d, II, and III-1b is 90% to 100%.

2. A liquid-crystal medium according to claim 1, wherein said medium further contains one or more compounds of formulae I-1 and I-2, and wherein said one or more compounds of formula II are selected from compounds of formulae II-1 to II-3 ##STR00229## in which R.sup.1, R.sup.2, A.sup.21, and A.sup.22 have the respective meanings given in claim 1, and ##STR00230## independently of one another, denote ##STR00231## alternatively denotes ##STR00232##

3. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds of formula I-2, and one or more compounds of formula II-1.

4. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from formulae I-1a to I-1c: ##STR00233##

5. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from formulae II-1a to II-1e: ##STR00234##

6. A liquid-crystal medium according to claim 5, wherein R.sup.2 denotes C.sub.nH.sub.2n+1 or CH.sub.2CH(CH.sub.2).sub.z, n denotes an integer in the range from 0 to 15, and z denotes 0, 1, 2, 3 or 4.

7. A liquid-crystal medium according to claim 1, wherein, in addition to said one or more compounds selected from formulae I-3a to I-3d, said medium contains one of more compounds of formula I that are not of formulae I-3a to I-3d: formula I: ##STR00235## in which R.sup.1 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, n denotes 0 or 1, and ##STR00236## independently of one another, denote ##STR00237## alternatively denotes ##STR00238##

8. A liquid-crystal medium according to claim 7, where R.sup.1 denotes unfluorinated alkyl having 1 to 17 C atoms or unfluorinated alkenyl having 2 to 15 C atom.

9. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from formulae I-2a to I-2d: ##STR00239##

10. A liquid-crystal medium according to claim 9, where R.sup.1 denotes unfluorinated alkyl having 1 to 17 C atoms or unfluorinated alkenyl having 2 to 15 C atom.

11. A liquid-crystal medium according to claim 1, wherein said medium further comprises one or more compounds selected from formulae III-1a, III-1c, and III-1d: ##STR00240##

12. A liquid-crystal medium according to claim 11, wherein R.sup.3 denotes C.sub.nH.sub.2n+1 or CH.sub.2CH(CH.sub.2).sub.z, n denotes an integer in the range from 0 to 15, and z denotes 0, 1, 2, 3 or 4.

13. A liquid-crystal medium according to claim 5, wherein said medium contains one or more compounds selected from II-1b.

14. A liquid-crystal medium according to claim 7, wherein said medium contains one or more compounds selected from I-3c.

15. A liquid-crystal medium according to claim 9, wherein said medium contains one or more compounds selected from I-2d.

16. A component for high-frequency technology, comprising a liquid crystal medium according to claim 1.

17. A component according to claim 16, wherein said component is suitable for operation in the microwave range.

18. A component according to claim 16, wherein said component is a phase shifter or a LC based antenna element operable in the microwave region.

19. A process for the preparation of a liquid-crystal medium according to claim 1, said process comprising mixing one or more compounds selected from formulae I-3a to I-3d, one or more compounds selected from formula II, and one or more compounds selected from formula III-1b, and optionally with one or more further compounds and/or with one or more additives.

20. A microwave antenna array comprising one or more components according to claim 16.

21. A liquid-crystal medium according to claim 2, wherein said medium further contains one or more compounds selected from formulae III-2 to III-6 ##STR00241## in which R.sup.3 has the meaning given in claim 1, ##STR00242## independently of one another, denote ##STR00243## alternatively independently denotes ##STR00244## and Z.sup.31 and Z.sup.32 independently of one another denote trans-CHCH or trans-CFCF, and in formula 111-6 alternatively one of Z.sup.31 and Z.sup.32 may denote CC.

22. A liquid-crystal medium according to claim 1, wherein said medium contains one or more compounds selected from I-3c.

23. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from I-3c.

24. A liquid-crystal medium according to claim 21, wherein said medium contains one or more compounds selected from formula I-3c.

25. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from formula II-2.

26. A liquid-crystal medium according to claim 2, wherein said medium contains one or more compounds selected from formula II-3.

27. A liquid-crystal medium according to claim 2, wherein said medium has a clearing point of 100 C. or more.

28. A liquid-crystal medium according to claim 1, wherein the amount of compounds of formula III-1b in said medium is in the range from 10 to 40 wt. %.

29. A liquid-crystal medium according to claim 1, wherein the amount of compounds of formula III-1b in said medium is in the range from 14 to 45 wt. %.

30. A liquid-crystal medium according to claim 1, wherein the liquid-crystal medium has a clearing point of 120 C. or more.

Description

EXAMPLES

(1) The following examples illustrate the present invention without limiting it in any way.

(2) However, it is clear to the person skilled in the art from the physical properties what properties can be achieved and in what ranges they can be modified. In particular, the combination of the various properties which can preferably be achieved is thus well defined for the person skilled in the art.

Examples 1 to 12 and Comparative Example

COMPARATIVE EXAMPLE

(3) A liquid-crystal mixture C-1 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave

(4) TABLE-US-00007 Composition Compound Conc./ No. Abbreviation mass-% Physical Properties 1 PPTUI-3-2 20.0 T(N, I)/ C. = 173 2 PPTUI-3-4 36.0 n (20 C., 589.3 nm) = 0.335 3 GGP-3-CL 10.0 (20 C., 1 kHz) = 4.6 4 GGP-5-CL 20.0 .sub.1 (20 C.)/mPa .Math. s = 746 5 CPGP-5-2 7.0 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0143 6 CPGP-5-3 7.0 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0038 100.0 (20 C., 19 GHz) = 0.252 (20 C., 19 GHz) = 17.6

(5) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region, however its response times are only moderate and not sufficient for more demanding applications.

Example 1

(6) A liquid-crystal mixture M-1 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(7) TABLE-US-00008 Composition Compound Conc./ No. Abbreviation mass-% Physical Properties 1 PVG-3-S 6.0 T(N, I)/ C. = 112 2 PVG-4-S 16.0 n.sub.o (20 C., 589.3 nm) = 1.5454 3 PVG-5-S 6.0 n (20 C., 589.3 nm) = t.b.d. 4 PTG-3-S 10.0 .sub.|| (20 C., 1 kHz) = 25.7 5 PTG-5-S 14.0 (20 C., 1 kHz) = 4.4 6 PTU-3-S 8.0 .sub.1 (20 C.)/mPa .Math. s = 270 7 PGU-3-S 8.0 tan .sub. .sub.r, 0.0143 (20 C., 19 GHz) = 8 PPTU-4-S 16.0 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0038 9 PPTU-5-S 16.0 (20 C., 19 GHz) = 0.252 100.0 (20 C., 19 GHz) = 17.6

(8) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 2

(9) A liquid-crystal mixture M-2 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(10) TABLE-US-00009 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 16.0 T(N, I)/ C. = 100 2 PVG-4-S 13.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PVG-5-S 13.0 n (20 C.,589.3 nm) = t.b.d. 4 PTU-3-S 7.0 .sub.|| (20 C., 1 kHz) = 28.2 5 PTU-5-S 7.0 (20 C., 1 kHz) = 5.0 6 PGU-3-S 24.0 .sub.1 (20 C.)/mPa .Math. s = 245 7 PPTU-4-S 10.0 tan .sub. .sub.r, (20 C., 19 GHz) = t.b.d. 8 PPTU-5-S 10.0 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = t.b.d. 100.0 (20 C., 19 GHz) = t.b.d. (20 C., 19 GHz) = t.b.d. Remark: t.b.d.: to be determined. k.sub.11 = 15.8 pN; k.sub.33 = 15.1 V; V.sub.10 = 0.87 V

(11) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the Comparison Example 1 this mixture clearly exhibits superior response times.

Example 3

(12) A liquid-crystal mixture M-3 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(13) TABLE-US-00010 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 18.0 T(N, I)/ C. = 93 2 PVG-4-S 13.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PVG-5-S 13.0 n (20 C., 589.3 nm) = t.b.d. 4 PTU-3-S 8.0 .sub.|| (20 C., 1 kHz) = 27.7 5 PTU-5-S 8.0 (20 C., 1 kHz) = 5.0 6 PGU-3-S 20.0 .sub.1 (20 C.)/mPa .Math. s = 225 7 PPTU-4-S 10.0 tan .sub. .sub.r, (20 C., 19 GHz) = t.b.d. 8 PPTU-5-S 10.0 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = t.b.d. 100.0 (20 C., 19 GHz) = t.b.d. (20 C., 19 GHz) = t.b.d. Remark: t.b.d.: to be determined. k.sub.11 = 15.0 pN; k.sub.33 = 15.4 V; V.sub.10 = 0.86 V

(14) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

(15) TABLE-US-00011 TABLE 5 Comparison of the properties at 19 GHz and 20 C. Example Liquid crystal .sub.r .sub. .sub.r, 1 M-1 0.56 0.013 14.5 Comparison 5CB 0.026 4.3

Example 4

(16) A liquid-crystal mixture M-4 having the composition and properties as indicated in the following table is prepared.

(17) TABLE-US-00012 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 GGP-3-S 8.0 T(N, I)/ C. = 98 2 PGG-3-S 12.0 n.sub.e (20 C., 589.3 nm) = t.b.d. 3 PGU-3-S 12.0 n (20 C., 589.3 nm) = t.b.d. 4 PVG-3-S 6.0 .sub.|| (20 C., 1 kHz) = 26.7 5 PVG-4-S 18.0 (20 C., 1 kHz) = 5.1 6 PTG-3-S 10.0 k.sub.11 (20 C.)/pN 17.7 7 PTG-5-S 18.0 k.sub.33 (20 C.)/pN 15.7 8 PTU-3-S 10.0 V.sub.0 (20 C.)/V 0.96 9 PPTU-4-S 6.0 .sub.1 (20 C.)/mPa .Math. s = 698 100.0 tan .sub.r,max (20 C., 19 GHz) = 0.0189 (20 C., 19 GHz) = 0.336 (20 C., 19 GHz) = 17.9 Remark: t.b.d.: to be determined.

(18) This mixture is very highly suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the MW region.

Examples 5 to 9

(19) To the liquid crystalline medium M-4 of Example 4 alternatively a certain concentration of a further single compound one each is added and the resultant mixtures (M-5 to M-9) are investigated for their general physical properties and for their performance in the microwave regime.

(20) TABLE-US-00013 Composition Example Mixture Compound c(Comp.) c(M-4) No. No. Abbreviation / % 4 M-4 None 0.0 100.0 5 M-5 PTPI(c3)TU-4-F 5.0 95.0 6 M-6 PTPI(2)WU-6-F 10.0 90.0 7 M.7 PTPI(2)GU-4-F 10.0 90.0 8 M-8 PTG(c3)TU-4-F 5.0 95.0 9 M-9 PTN(1,4)TP-3-F 5.0 95.0

(21) TABLE-US-00014 Physical Properties I, General I (20 C. except T(N.I) ) Example Mixture T(N, I)/ No. No. C. n .sub.|| 4 M-4 98 t.b.d. 26.7 21.5 5 M-5 98 t.b.d. 26.1 20.9 6 M-6 90 t.b.d. 26.0 21.0 7 M.7 102 t.b.d. 27.0 21.9 8 M-8 93.9 t.b.d. 27.0 21.8 9 M-9 99.5 t.b.d. 25.9 20.9 Remark: t.b.d.: to be determined.

(22) TABLE-US-00015 Physical Properties II, General II (20 C.) Example Mixture No. No. .sub.1 k.sub.11/pN k.sub.33/pN V.sub.0/V 4 M-4 241 17.7 15.7 0.96 5 M-5 254 15.1 14.6 0.90 6 M-6 272 15.8 15.8 0.91 7 M.7 319 16.0 16.9 0.90 8 M-8 257 15.8 15.0 0.90 9 M-9 273 18.2 15.9 0.99

(23) TABLE-US-00016 Physical Properties III, Microwave I (20 C., 19 GHz) Example Mixture No. No. .sub.r, .sub.r,|| tan .sub. .sub.r,|| tan .sub. .sub.r, 4 M-4 3.74 2.49 0.0189 0.0091 5 M-5 3.68 2.48 0.0177 0.0088 6 M-6 3.67 2.49 0.0174 0.0084 7 M.7 3.68 2.48 0.0170 0.0082 8 M-8 3.70 2.49 0.0180 0.0088 9 M-9 3.73 2.49 0.0175 0.0085

(24) TABLE-US-00017 Physical Properties IV, Microwave II (20 C., 19 GHz) Example Mixture No. No. tan .sub. .sub.r, .sub. .sub.r 4 M-4 0.0189 0.336 17.8 5 M-5 0.0177 0.326 18.4 6 M-6 0.0174 0.323 18.6 7 M.7 0.0170 0.327 19.3 8 M-8 0.0180 0.327 18.1 9 M-9 0.0175 0.332 19.0

(25) These mixtures are very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the MW region.

(26) The mixtures of examples 4 to 9 are treated and investigated as described under example 1. The resultant mixtures comprising the chiral compound in the respective concentrations show similarly improved properties. They are especially characterized in particular by improved response times.

Example 10

(27) A liquid-crystal mixture M-10 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(28) TABLE-US-00018 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 10.0 T(N, I)/ C. = 126.5 2 PTU-3-S 10.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PTU-5-S 10.0 n (20 C., 589.3 nm) = t.b.d. 4 CGU-2-S 10.0 .sub.|| (20 C., 1 kHz) = 27.1 5 CGU-3-S 10.0 (20 C., 1 kHz) = 4.5 6 CGU-4-S 10.0 .sub.1 (20 C.)/mPa .Math. s = 299 7 CGU-5-S 10.0 k.sub.1 (20 C.)/pN = 14.8 8 PGU-3-S 16.0 k.sub.3/k.sub.1 (20 C.) = 1.43 9 PPTU-4-S 7.0 V.sub.0 (20 C.)/V = 0.86 10 PPTU-5-S 7.0 .sub.r, (20 C., 19 kHz) = 2.36 100.0 .sub.r,| .sub.| (20 C., 19 kHz) = 3.44 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0116 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0064 (20 C., 19 GHz) = 0.315 (20 C., 19 GHz) = 27.2 Remark: t.b.d.: to be determined.

(29) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 11

(30) A liquid-crystal mixture M-11 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(31) TABLE-US-00019 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 10.0 T(N, I)/ C. = 123 2 PTU-3-S 10.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PTU-5-S 10.0 n (20 C., 589.3 nm) = t.b.d. 4 CGU-2-S 20.0 .sub.|| (20 C., 1 kHz) = 26.9 5 CGU-4-S 20.0 (20 C., 1 kHz) = 4.7 6 PGU-3-S 16.0 .sub.1 (20 C.)/mPa .Math. s = 287 7 PPTU-4-S 7.0 k.sub.1 (20 C.)/pN = 14.0 8 PPTU-5-S 7.0 k.sub.3/k.sub.1 (20 C.) = 1.39 100.0 V.sub.0 (20 C.)/V = 0.84 .sub.r, (20 C., 19 kHz) = 2.36 .sub.r,| .sub.| (20 C., 19 kHz) = 3.42 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0116 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0066 (20 C., 19 GHz) = 0.310 (20 C., 19 GHz) = 26.7 Remark: t.b.d.: to be determined.

(32) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 12

(33) A liquid-crystal mixture M-12 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(34) TABLE-US-00020 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 14.0 T(N, I)/ C. = t.b.d. 2 PTU-3-S 14.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 CGU-2-S 20.0 n (20 C., 589.3 nm) = t.b.d. 4 CGU-4-S 20.0 .sub.|| (20 C., 1 kHz) = t.b.d. 5 PGU-3-S 18.0 (20 C., 1 kHz) = t.b.d. 6 PPTU-4-S 7.0 .sub.1 (20 C.)/mPa .Math. s = t.b.d. 7 PPTU-5-S 10.0 k.sub.1 (20 C.)/pN = t.b.d. 100.0 k.sub.3/k.sub.1 (20 C.) = t.b.d. V.sub.0 (20 C.)/V = t.b.d. .sub.r, (20 C., 19 kHz) = t.b.d. .sub.r,| .sub.| (20 C., 19 kHz) = t.b.d. tan .sub. .sub.r, (20 C., 19 GHz) = t.b.d. tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = t.b.d. (20 C., 19 GHz) = t.b.d. (20 C., 19 GHz) = t.b.d. Remark: t.b.d.: to be determined.

(35) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 13

(36) A liquid-crystal mixture M-13 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(37) TABLE-US-00021 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 8.0 T(N, I)/ C. = 121.5 2 PVG-4-S 8.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PVG-5-S 8.0 n (20 C., 589.3 nm) = t.b.d. 4 PTU-3-S 8.0 .sub.|| (20 C., 1 kHz) = 26.2 5 PTU-5-S 8.0 (20 C., 1 kHz) = 4.6 6 CGU-3-S 10.0 .sub.1 (20 C.)/mPa .Math. s = 298 7 CGU-4-S 10.0 k.sub.1 (20 C.)/pN = 16.0 8 CGU-5-S 10.0 k.sub.3/k.sub.1 (20 C.) = 1.31 9 PGU-3-S 16.0 V.sub.0 (20 C.)/V = 0.91 9 PPTU-4-S 7.0 .sub.r, (20 C., 19 kHz) = 2.36 11 PPTU-5-S 7.0 .sub.r,| .sub.| (20 C., 19 kHz) = 3.48 100.0 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0121 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0067 (20 C., 19 GHz) = 0.321 (20 C., 19 GHz) = 26.5 Remark: t.b.d.: to be determined.

(38) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 14

(39) A liquid-crystal mixture M-14 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(40) TABLE-US-00022 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 8.0 T(N, I)/ C. = 124 2 PVG-4-S 8.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PVG-5-S 8.0 n (20 C., 589.3 nm) = t.b.d. 4 PTU-3-S 8.0 .sub.|| (20 C., 1 kHz) = 26.2 5 PTU-5-S 8.0 (20 C., 1 kHz) = 4.6 6 CGU-4-S 15.0 .sub.1 (20 C.)/mPa .Math. s = 311 7 CGU-5-S 15.0 k.sub.1 (20 C.)/pN = 16.2 8 PGU-3-S 16.0 k.sub.3/k.sub.1 (20 C.) = 1.28 9 PPTU-4-S 7.0 V.sub.0 (20 C.)/V = 0.91 10 PPTU-5-S 7.0 .sub.r, (20 C., 19 kHz) = 2.37 100.0 .sub.r,| .sub.| (20 C., 19 kHz) = 3.48 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0120 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0066 (20 C., 19 GHz) = 0.318 (20 C., 19 GHz) = 26.2 Remark: t.b.d.: to be determined.

(41) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

Example 15

(42) A liquid-crystal mixture M-15 having the composition and properties as indicated in the following table is prepared and characterized with respect to its general physical properties and its applicability in microwave components at 19 GHz.

(43) TABLE-US-00023 Composition Compound Conc./ No Abbreviation mass-% Physical Properties 1 PU-3-S 10.0 T(N, I)/ C. = 126.5 2 PTU-3-S 10.0 n.sub.o (20 C., 589.3 nm) = t.b.d. 3 PTU-5-S 10.0 n (20 C., 589.3 nm) = t.b.d. 4 CGU-2-S 14.0 .sub.|| (20 C., 1 kHz) = 27.4 5 CGU-3-S 13.0 (20 C., 1 kHz) = 4.6 6 CGU-4-S 13.0 .sub.1 (20 C.)/mPa .Math. s = 297 7 PGU-3-S 16.0 k.sub.1 (20 C.)/ = 14.5 8 PPTU-4-S 7.0 k.sub.3/k.sub.1 (20 C.) = 1.45 9 PPTU-5-S 7.0 V.sub.0 (20 C.)/V = 0.84 100.0 .sub.r, (20 C., 19 kHz) = 2.36 .sub.r,| .sub.| (20 C., 19 kHz) = 3.44 tan .sub. .sub.r, (20 C., 19 GHz) = 0.0115 tan .sub. .sub.r,| .sub.| (20 C., 19 GHz) = 0.0065 (20 C., 19 GHz) = 0.313 (20 C., 19 GHz) = 27.2 Remark: t.b.d.: to be determined.

(44) This mixture is suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region. In comparison to the comparative example this mixture clearly exhibits superior response times.

(45) The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

(46) From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.