Liquid crystal medium and high frequency components comprising same

Abstract

The present invention relates to liquid crystal media and to high frequency components comprising same, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves.

Claims

1. A liquid crystal medium, comprising 10% to 85% by weight, based on the medium, of a first component, component A, consisting of one, two, three or more compounds of formula I ##STR00131## wherein L.sup.1 is R.sup.12 or X.sup.1, R.sup.11 is C.sub.nH.sub.2n+1, OC.sub.nH.sub.2n+1 or CH.sub.2CH(CH.sub.2).sub.Z, R.sup.12 is C.sub.mH.sub.2m+1 or OC.sub.mH.sub.2m+1 or (CH.sub.2).sub.ZCHCH.sub.2, X.sup.1 is F or Cl, Y.sup.11 and Y.sup.12 are independently of one another H or F, n and m independently of one another, denote an integer in the range from 1 to 9 and z denotes 0, 1, 2, 3 or 4, and a second component, component B, consisting of one, two, three or more compounds of formulae III, IV, V or VI ##STR00132## wherein L.sup.31 denotes R.sup.31, L.sup.32 denotes R.sup.32, R.sup.31 and R.sup.32, independently of one another, denote H, non-fluorinated alkyl or alkoxy having 1 to 15 or non-fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15 C atoms, Z.sup.31 to Z.sup.33, independently of one another, denote trans-CHCH, trans-CHCF, trans-CFCH, trans-CFCF or a single bond, ##STR00133## denotes ##STR00134## ##STR00135## denote independently of one another ##STR00136## with one of ##STR00137## being ##STR00138## ##STR00139## alternatively may denote ##STR00140## and R.sup.33 to R.sup.35, independently of one another, denote non-fluorinated alkyl or alkoxy having 1 to 15 or non-fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 15 C atoms, ##STR00141## wherein R.sup.41 to R.sup.43, independently of one another, denote non-fluorinated alkyl or non-fluorinated alkoxy, each having 1 to 15 C atoms, non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms and L.sup.4 denotes F, or non-fluorinated alkyl or non-fluorinated alkoxy, each having 1 to 15 C atoms, non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl, each having 2 to 15 C atoms, ##STR00142## wherein R.sup.51 and R.sup.52, independently of one another, denote halogen, non-fluorinated alkyl or fluorinated alkyl or non-fluorinated alkoxy or fluorinated alkoxy, each having 1 to 15 C atoms, or non-fluorinated alkenyl or fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl or fluorinated alkoxyalkyl, each having 2 to 15 C atoms, in which, in addition, one or more CH.sub.2 groups may be replaced, independently of one another, by cycloalkyl having 3 to 6 C atoms, and alternatively, in addition, one of R.sup.51 and R.sup.52 or both R.sup.51 and R.sup.52 denote H, L.sup.51 to L.sup.54 on each appearance, in each case independently of one another, denote H, alkyl having 1 to 15 C atoms, F or Cl, and i denotes an integer in the range from 5 to 15, and ##STR00143## wherein R.sup.61 and R.sup.62, independently of one another, denote halogen, non-fluorinated alkyl or fluorinated alkyl or non-fluorinated alkoxy or fluorinated alkoxy, each having 1 to 15 C atoms, or non-fluorinated alkenyl or fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl or fluorinated alkoxyalkyl, each having 2 to 15 C atoms, in which, in addition, one or more CH.sub.2 groups may be replaced, independently of one another, by cycloalkyl having 3 to 6 C atoms, R.sup.63 and R.sup.64, independently of one another, denote alkyl having 1 to 15 C atoms, and, alternatively, one of them also denotes H, Z.sup.6 denotes CC or a single bond.

2. The liquid crystal medium according to claim 1, comprising the compounds of formula I in a total concentration in the range of 40% or more to 85% or less.

3. The liquid crystal medium according to claim 1, comprising one or more compounds of formula II ##STR00144## wherein L.sup.21 denotes R.sup.21 or X.sup.21, L.sup.22 denotes R.sup.22 or X.sup.22, R.sup.21 and R.sup.22, independently of one another, denote H, non-fluorinated alkyl or non-fluorinated alkoxy having 1 to 17 C atoms or non-fluorinated alkenyl, non-fluorinated alkenyloxy or non-fluorinated alkoxyalkyl having 2 to 15 C atoms, X.sup.21 and X.sup.22, independently of one another, denote H, F, Cl, CN, NCS, SF.sub.5, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, non-fluorinated or fluorinated alkenyloxy or non-fluorinated or fluorinated alkoxyalkyl having 2 to 7 C atoms, ##STR00145## independently of one another, denote ##STR00146##

4. The liquid crystal medium according to claim 3, consisting of compounds of formula I and compounds of formulae II to VI.

5. The liquid crystal medium according to claim 3, additionally comprising one or more compounds of formulae II-1a-1 to II-1a-4 ##STR00147## wherein R.sup.21 has the meaning given for R.sup.11.

6. The liquid crystal medium according to claim 1, additionally comprising one or more compounds of formula III.

7. The liquid crystal medium according to claim 1, comprising one or more compounds of the formula IV.

8. The liquid crystal medium according to claim 1, comprising one or more compounds of formula V.

9. The liquid crystal medium according to claim 1, comprising one or more compounds of formula VI.

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

11. The component according to claim 10, that is suitable for operation in the microwave range.

12. The component according to claim 10, that is a phase shifter.

13. A microwave device, comprising one or more components according to claim 10.

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 range of properties is achievable and over which ranges they may be modified. In particular, the combination of the various properties that is achievable preferably is thus well defined for the person skilled in the art.

Comparative Example 1

(3) A liquid crystal mixture C-1 having the composition and properties as indicated in the following table is prepared and investigated.

(4) TABLE-US-00005 Composition Compound No. Abbreviation 1 PPTUI-3-4 25.1 2 PPTUI-4-4 48.5 3 PPTUI-3-2 26.4 100.0 Physical properties T(N, I) = 163.5 C. n.sub.e (20 C., 589.3 nm) = 1.8729 n (20 C., 589.3 nm) = 0.3984 .sub.|| (20 C., 1 kHz) = 3.8 (20 C., 1 kHz) = 1.0 .sub.1 (20 C.) = 310 mPa .Math. s k.sub.1 (20 C.) = 17.3 pN k.sub.1/k.sub.3 (20 C.) = 2.20 V.sub.0 (20 C., 1 kHz) = 4.04 V

(5) TABLE-US-00006 TABLE 1 Properties of mixture C-1 at 30 GHz T/ C. .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub., r, 20 3.2 2.4 0.0070 0.0150

(6) This mixture is only moderately well suited for applications in the microwave range.

Example 1

(7) A liquid crystal mixture M-1 having the composition and properties as indicated in the following table is prepared and investigated.

(8) TABLE-US-00007 Composition Compound # Abbreviation 1 PPTUI-3-2 25.0 2 PPTUI-3-4 25.0 3 PPTUI-4-4 25.0 4 PTP(2)TP-6-3 25.0 100.0 Physical properties T(N, I) = 154 C. n.sub.e (20 C., 589.3 nm) = t.b.d. n (20 C., 589.3 nm) = t.b.d. .sub.|| (20 C., 1 kHz) = 3.7 (20 C., 1 kHz) = 0.8 .sub.1 (20 C.) = 718 mPa .Math. s k.sub.1 (20 C.) = 17.4 pN k.sub.1/k.sub.3 (20 C.) = 1.54 V.sub.0 (20 C., 1 kHz) = 2.05 V Remarks: t.b.d.: to be determined.

(9) TABLE-US-00008 TABLE 2 Properties of mixture M-1 at 30 GHz T/ C. .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub., r, 20 3.2 2.4 0.0057 0.0128

(10) This mixture is highly suitable for applications in the microwave range due to its lower value for tan .sub.,r,, in particular for phase shifters.

Comparative Example 2

(11) A liquid crystal mixture C-2 having the composition and properties as indicated in the following table is prepared and investigated.

(12) TABLE-US-00009 Composition Compound No. Abbreviation 1 PPTUI-3-2 20.0 2 PPTUI-3-4 20.0 3 PTP-2-O1 10.0 4 PTP-3-O1 10.0 5 GGP-3-Cl 10.0 6 GGP-5-Cl 20.0 7 PGP-2-3 10.0 100.0 Physical properties T(N, I) = 120 C. n.sub.e (20 C., 589.3 nm) = t.b.d. n (20 C., 589.3 nm) = t.b.d. .sub.|| (20 C., 1 kHz) = 7.6 (20 C., 1 kHz) = 3.9 .sub.1 (20 C.) = t.b.d. mPa .Math. s k.sub.1 (20 C.) = 13.8 pN k.sub.1/k.sub.3 (20 C.) = 1.7 V.sub.0 (20 C., 1 kHz) = 1.99 V Remarks: t.b.d.: to be determined.

(13) TABLE-US-00010 TABLE 3 Properties of mixture C-2 at 30 GHz T/ C. .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub., r, 20 3.2 2.5 0.0060 0.0190

(14) This mixture is moderately well suited for applications in the microwave range, in particular for phase shifters.

Example 2

(15) A liquid crystal mixture M-2 having the composition and properties as indicated in the following table is prepared and investigated.

(16) TABLE-US-00011 Composition Compound # Abbreviation 1 GGP-4-Cl 8.0 2 GGP-5-Cl 22.0 3 PPTUI-3-2 23.0 4 PPTUI-3-5 22.0 5 PPTUI-4-4 16.0 6 PTP(2)ITP(2)P-4-4 19.0 100.0 Physical properties T(N, I) = 152 C. n.sub.e (20 C., 589.3 nm) = t.b.d. n (20 C., 589.3 nm) = t.b.d. .sub.|| (20 C., 1 kHz) = 7.7 (20 C., 1 kHz) = 4.3 .sub.1 (20 C.) = t.b.d. mPa .Math. s k.sub.1 (20 C.) = 16.4 pN k.sub.1/k.sub.3 (20 C.) = 2.06 V.sub.0 (20 C., 1 kHz) = 2.05 V Remarks: t.b.d.: to be determined.

(17) TABLE-US-00012 TABLE 4 Properties of mixture M-2 at 30 GHz T/ C. .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub., r, 20 3.1 2.4 0.0031 0.0140

(18) This mixture is stable in the bulk for storage at a temperature of 20 C. for more than 120 h. It is highly suitable for applications in the microwave range, e.g. at a frequency of 30 GHz, due to its improved respective properties, in particular for phase shifters.

Example 3

(19) A liquid crystal mixture M-3 having the composition and properties as indicated in the following table is prepared and investigated.

(20) TABLE-US-00013 Composition Compound # Abbreviation 1 GGP-3-CL 12.0 2 GGP-5-CL 20.0 3 PPTUI-3-2 20.0 4 PPTUI-3-4 20.0 5 PPTUI-4-4 20.0 6 PPP(2)P-4-4 8.0 100.0 Physical properties T(N, I) = 147.5 C. n.sub.e (20 C., 589.3 nm) = t.b.d. n (20 C., 589.3 nm) = t.b.d. .sub.|| (20 C., 1 kHz) = 8.1 (20 C., 1 kHz) = 4.7 .sub.1 (20 C.) = 718 mPa .Math. s k.sub.1 (20 C.) = 17.4 pN K.sub.1/k.sub.3 (20 C.) = 1.54 V.sub.0 (20 C., 1 kHz) = 2.05 V Remarks: t.b.d.: to be determined.

(21) TABLE-US-00014 TABLE 5 Properties of mixture M-3 at 30 GHz T/ C. .sub.r,|| .sub.r, tan .sub.,r,|| tan .sub., r, 20 3.1 2.4 0.0034 0.0133

(22) This mixture is very highly suitable for applications in the microwave range, in particular for phase shifters. It shows a favourably good stability against storage at low temperatures and a low values of the loss in the microwave range e.g. at frequencies of 30 GHz.