Liquid-crystalline medium, compounds, and high-frequency components

Abstract

Liquid-crystalline media containing one or more compounds of formulae I-1, I-2 and/or I-3 ##STR00001##
and one or more compounds of formulae II and/or III ##STR00002##
and components containing 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 of formulae I-1 and I-2 and I-3, wherein the total concentration of the one or more compounds of formulae I-1 and I-2 and I-3 in the medium is 73% to 100% by weight and wherein the concentration of the one or more compounds of formula I-2 in the medium is 25% to 40% by weight, and the concentration of the one or more compounds of formula I-3 in the medium is 45% or more by weight or wherein the concentration of the one or more compounds of formula I-3 in the medium is more than 50% by weight ##STR00236## in which R.sup.1 denotes alkyl having 1 to 7 C atoms or alkenyl having 2 to 7 C atoms, L.sup.1 denotes H or F, ##STR00237## independently of one another, denote ##STR00238## and one or more compounds of formulae II and/or III, wherein the concentration of the one or more compounds of formulae II and/or III is 0% to 27% by weight ##STR00239## in which R.sup.2 denotes H, alkyl or alkoxy having 1 to 17 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15 C atoms, z.sup.21 denotes trans-CHCH, trans-CFCF or CC ##STR00240## denotes ##STR00241## ##STR00242## denotes ##STR00243## R.sup.3 denotes H, alkyl or alkoxy having 1 to 17 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15 C atoms, one of Z.sup.31 and Z.sup.32 denotes trans-CHCH-, trans-CF=CF or and the other one of Z.sup.31 and Z.sup.32 denotes trans-CHCH, trans-CFCF or a single bond, ##STR00244## independently of one another, denote ##STR00245## alternatively independently denotes ##STR00246##

2. A medium according to claim 1, which comprises one or more compounds of formulae I-3a to I-3d: ##STR00247##

3. A medium according to claim 2, which comprises one or more compounds of formula I-3c in a total concentration of 30% to 70% by weight.

4. A medium according to claim 1, which comprises a compound of formula I-1 in a total concentration of 20% or more.

5. A medium according to claim 1, wherein the one or more compounds of formula I-1 are of formula I-1b ##STR00248##

6. A medium according to claim 1, which additionally comprises one or more chiral compounds.

7. A liquid-crystal medium, comprising one or more compounds of formula I ##STR00249## in which R.sup.1 denotes H, alkyl or alkoxy having 1 to 17 C atoms or alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15 C atoms, n=2, one of ##STR00250## denotes ##STR00251## and the other denotes ##STR00252## independently of one another, denote ##STR00253## wherein the total concentration of the one or more compounds of formula I in the medium is 73% or more by weight.

8. A component for high-frequency technology, which comprises a liquid crystal medium according to claim 1.

9. A component according to claim 8, which is suitable for operation in the microwave range.

10. A component according to claim 8, which is a phase shifter or an LC based antenna element operable in the microwave region.

11. A process for the preparation of a liquid-crystal medium according to claim 1, comprising mixing together one or more compounds of formulae I-1 and I-2 and I-3, and optionally one or more compounds of formulae II and/or III, and optionally a chiral compound.

12. A microwave antenna array, which comprises one or more components according to claim 8.

13. A medium according to claim 1, where the total concentration of the one or more compounds of formulae I-1 and I-2 and I-3 in the medium is 80-90% by weight.

14. A medium according to claim 1, wherein the concentration of the one or more compounds of formula I-2 in the medium is 25% to 40% by weight, and the concentration of the one or more compounds of formula I-3 in the medium is 45% or more by weight.

15. A medium according to claim 1, wherein the concentration of the one or more compounds of formula I-3 in the medium is more than 50% by weight.

16. A medium according to claim 7, where the total concentration of the one or more compounds of formula I in the medium is 80-90% by weight.

17. A component for high-frequency technology, which comprises a liquid crystal medium according to claim 7.

18. A medium according to claim 1, which comprises one or more compounds of formulae II and/or III, wherein the concentration of the one or more compounds of formulae II and/or III is 2% to 20% by weight.

19. A liquid-crystal medium according to claim 1, wherein the total concentration of the one or more compounds of formulae I-1 and I-2 and I-3 in the medium is 80% to 100% by weight and wherein the concentration of the one or more compounds of formulae II and/or III is 0% to 20% by weight.

20. A component for high-frequency technology, which comprises a liquid crystal medium according to claim 19.

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.

Synthesis Example 1

Step 1: 2,6-Difluoro-4-[2-fluoro-4-[4-(4-propylphenyl)phenyl]phenyl]aniline

(3) ##STR00234##

(4) 11.8 g (26.7 mmol) [2-fluoro-4-[4-(4-propylphenyl)phenyl]phenyl]trifluoromethane sulfonate and 10.4 g (40.1 mmol) 2,6-difluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline are dissolved in 30 ml tetrahydrofuran. Then, 15 ml water, 40 l hydrazinium hydrate, 375 mg bis(triphenylphosphine palladium(II)choride and sodium metaborate octahydrate are added and the reaction is heated under reflux for 3 h. The reaction is filtered, evaporated and the crude product is purified by chromatography and recrystallised from toluene. 2,6-Difluoro-4-[2-fluoro-4-[4-(4-propylphenyl)phenyl]phenyl]aniline is obtained as colourless crystals.

Step 2: 1,3-Difluoro-5-[2-fluoro-4-[4-(4-propylphenyl)phenyl]phenyl]-2-isothiocyanato-benzene

(5) ##STR00235##

(6) 8.9 (20.9 mmol) 2,6-difluoro-4-[2-fluoro-4-[4-(4-propylphenyl)-phenyl]phenyl]aniline and 5.97 g (33 mmol) thiocarbonyl diimidazole are dissolved in 100 ml dichloromethane and heated under reflux for 3 d. The reaction is filtered, the filtrate evaporated and the crude product is purified by chromatography to give 1,3-difluoro-5-[2-fluoro-4-[4-(4-propyl-phenyl)phenyl]phenyl]-2-isothiocyanato-benzene as colourless crystals.

(7) Phase Sequence: K 127 SmC 132 N 354 I.

(8) n=0.4604.sup.[1]

(9) =23.5.sup.[1].sup.[1] Extrapolated from a 10% solution in ZLI-4292

Comparative Example 1 (Example 4 from EP2982730)

(10) 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 applications.

(11) TABLE-US-00007 Composition Compound Abbre- Conc./ No viation mass-% Physical Properties 1 GGP-3-S 8.0 T(N, I)/ C.= 98 2 PGG-3-S 12.0 .sub. (20 C., 1 kHz)= 26.7 3 PGU-3-S 12.0 (20 C., 1 kHz)= 5.1 4 PVG-3-S 6.0 k.sub.11 (20 C.)/pN 17.7 5 PVG-4-S 18.0 k.sub.33 (20 C.)/pN 15.7 6 PTG-3-S 10.0 V.sub.0 (20 C.)/V 0.96 7 PTG-5-S 18.0 .sub.1(20 C.)/mPa .Math. s= 698 8 PTU-3-S 10.0 tan.sub.r, max 0.0189 (20 C., 19 GHz)= 9 PPTU-4-S 6.0 (20 C., 19 GHz)= 0.336 100.0 (20 C., 19 GHz)= 17.9

(12) This mixture comprises 68% of stilbene and tolane derivatives and 32% of compounds of formula I.

Comparative Example 2 (Example 14 from EP2982730)

(13) A liquid-crystal mixture C-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

(14) TABLE-US-00008 Composition Compound Abbre- Conc./ No viation mass-% Physical Properties 1 PU-3-S 8.0 T(N, I)/ C.= 124 2 PVG-4-S 8.0 .sub.(20 C., 1 kHz)= 26.2 3 PVG-5-S 8.0 (20 C., 1 kHz)= 4.6 4 PTU-3-S 8.0 .sub.1 (20 C.)/mPa .Math. s= 311 5 PTU-5-S 8.0 k.sub.1 (20 C.)/pN= 16.2 6 CGU-4-S 15.0 k.sub.3/k.sub.1 (20 C.)= 1.28 7 CGU-5-S 15.0 V.sub.0 (20 C.)/V= 0.91 8 PGU-3-S 16.0 9 PPTU-4-S 7.0 .sub.r, (20 C., 2.37 19 GHz)= 10 PPTU-5-S 7.0 .sub.r, (20 C., 3.48 19 GHz)= 100.0 tan .sub.r, 0.0120 (20 C., 19 GHz)= tan .sub.r, 0.0066 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.318 (20 C., 19 GHz)= 26.5

(15) This mixture comprises 46% of stilbene and tolane derivatives and 54% of compounds of formula I.

Mixture Examples

(16) Liquid-crystal mixtures M-1 to M-5 having the composition and properties as indicated in the following tables are prepared and characterized with respect to their general physical properties and their applicability in microwave components at 19 GHz.

Mixture Example M-1

(17) TABLE-US-00009 Composition Compound Abbre- Conc./ No viation [mass-%] Physical Properties 1 PU-3-S 20.0 T(N, I) [ C.]= 134 2 PGU-3-S 15.0 .sub.(20 C., 1 kHz)= 27.3 3 PGU-4-S 15.0 (20 C., 1 kHz)= 22.6 4 CPU-2-S 15.0 .sub.1 (20 C.)/ 324 mPa .Math. s= 5 CPU-3-S 10.0 k.sub.1= 14.2 6 CPU-4-S 15.0 k.sub.3= 21.8 7 CPU-5-S 10.0 V.sub.0 [V]= 0.84 100.0 tan .sub.r, 0.0128 (20 C., 19 GHz)= tan .sub.r, 0.0069 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.291 .sub.r, (20 C., 3.3697 19 GHz)= .sub.r, (20 C., 2.3886 19 GHz)= (20 C., 19 GHz)= 22.7

(18) The mixture M-1 comprises 100% of compounds of formula I. This mixture is very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region.

Mixture Example M-2

(19) TABLE-US-00010 Composition Compound Abbre- Conc./ No viation [mass-%] Physical Properties 1 PU-3-S 20.0 T(N, I) [ C.]= 128 2 PGU-3-S 20.0 .sub.(20 C., 1 kHz)= 28.6 3 PGU-4-S 20.0 (20 C., 1 kHz)= 23.6 4 CPU-2-S 20.0 .sub.1 (20 C.)/ 318 mPa .Math. s= 5 CPU-3-S 20.0 k.sub.1= 13.7 100.0 k.sub.3= 18.6 V.sub.0 [V]= 0.80 tan .sub.r, 0.0133 (20 C., 19 GHz)= tan .sub.r, 0.0070 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.301 .sub.r, (20 C., 3.4113 19 GHz)= .sub.r, (20 C., 2.3842 19 GHz)= (20 C., 19 GHz)= 22.6

(20) The mixture M-2 comprises 100% of compounds of formula I. This mixture is very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region.

Mixture Example M-3

(21) TABLE-US-00011 Composition Compound Abbre- Conc. No viation [mass-%] Physical Properties 1 PU-3-S 20.0 T(N, I) [ C.]= 133 2 PGU-3-S 12.0 .sub.(20 C., 1 kHz)= 27.1 3 PGU-4-S 9.0 (20 C., 1 kHz)= 22.4 4 PGU-5-S 9.0 .sub.1 (20 C.)/ 331 mPa .Math. s= 5 CPU-2-S 15.0 k.sub.1= 14.5 6 CPU-3-S 10.0 k.sub.3= 22.2 7 CPU-4-S 15.0 V.sub.0 [V]= 0.85 8 CPU-5-S 10.0 100.0 tan .sub.r, 0.0135 (20 C, 19 GHz)= tan .sub.r, 0.0070 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.267 .sub.r, (20 C., 3.4771 19 GHz)= .sub.r, (20 C., 2.5471 19 GHz)= (20 C., 19 GHz)= 19.8

(22) The mixture M-3 comprises 100% of compounds of formula I. This mixture is very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region.

Mixture Example 4

(23) TABLE-US-00012 Composition Compound Abbre- Conc./ No viation [mass-%] Physical Properties 1 PU-3-S 24.0 T(N, I) [ C.]= 125 2 PGU-3-S 10.0 .sub.(20 C., 1 kHz)= 26.7 3 PGU-4-S 8.0 (20 C., 1 kHz)= 22.0 4 PGU-5-S 8.0 .sub.1 (20 C.)/ 296 mPa .Math. s= 5 CPU-2-S 15.0 k.sub.1= 13.8 6 CPU-3-S 10.0 k.sub.3= 20.8 7 CPU-4-S 15.0 V.sub.0 [V]= 0.83 8 CPU-5-S 10.0 100.0 tan .sub.r, 0.0134 (20 C., 19 GHz)= tan .sub.r, 0.0072 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.286 .sub.r, (20 C., 3.4169 19 GHz)= .sub.r, (20 C., 2.4380 19 GHz)= (20 C., 19 GHz)= 21.3

(24) The mixture M-4 comprises 100% of compounds of formula I. This mixture is very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region.

Mixture Example 5

(25) TABLE-US-00013 Composition Compound Abbre- Conv./ No viation [mass-%] Physical Properties 1 PU-3-S 24.0 T(N, I) [ C.]= 123 2 PGU-3-S 12.0 .sub.(20 C., 1 kHz)= 27.3 3 PGU-4-S 9.0 (20 C., 1 kHz)= 22.5 4 PGU-5-S 9.0 .sub.1 (20 C.)/ 303 mPa .Math. s= 5 CPU-2-S 15.0 k.sub.1= 13.8 6 CPU-3-S 9.0 k.sub.3= 20.6 7 CPU-4-S 13.0 V.sub.0 [V]= 0.83 8 CPU-5-S 9.0 100.0 tan .sub.r, 0.0135 (20 C., 19 GHz)= tan .sub.r, 0.0073 (20 C., 19 GHz)= (20 C., 19 GHz)= 0.288 .sub.r, (20 C., 3.4259 19 GHz)= .sub.r, (20 C., 2.4403 19 GHz)= (20 C., 19 GHz)= 21.3

(26) The mixture M-5 comprises 100% of compounds of formula I. This mixture is very well suitable for applications in the microwave range, in particular for phase shifters or LC based antenna elements in the micro wave (MW) region.

(27) In the following tables the physical properties of the Comparative Examples C-1 and C-2 and the Examples M-1 to M-5 are summarised. All values are determined at 20 C. and 19 GHz.

(28) TABLE-US-00014 Mixture C-1 C-2 tan .sub.r, 0.0189 0.0120 tan .sub.r, 0.0091 0.0066 0.336 0.318 .sub.r, N/A 3.48 .sub.r, N/A 2.37 5.1 1.11 17.9 26.5

(29) TABLE-US-00015 Mixture M-1 M-2 M-3 M-4 M-5 tan .sub.r, 0.0128 0.0133 0.0135 0.0134 0.0135 tan .sub.r, 0.0069 0.0070 0.0070 0.0072 0.0073 0.291 0.301 0.267 0.286 0.288 .sub.r, 3.3697 3.4113 3.4771 3.4169 3.4259 .sub.r, 2.3886 2.3842 2.5471 2.4380 2.4403 0.9811 1.0271 0.9300 0.9789 0.9856 22.7 22.6 19.8 21.3 21.3

(30) Surprisingly, mixtures according to the present invention, which do not comprise stilbene or tolane derivatives can be achieved having improved or comparably good properties as mixtures known from the state of the art that are based on compounds of formula I in combination with stilbene or tolane derivatives. It can be seen that the mixtures according to the invention even show an improved material quality () compared to the mixture C-1 known from the state of the art because of a much lower dielectric loss.

(31) Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.

(32) The entire disclosure[s] of all applications, patents and publications, cited herein and of corresponding application No. EP 16194405.3, filed Oct. 18, 2016 are incorporated by reference herein.