Liquid-crystalline medium and high-frequency components comprising same

Patent metadata

Field	Value
Publication number	US-10323188-B2
Application number	US-201515536690-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Dec 19, 2014
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

The present invention relates to liquid-crystalline media comprising
one or more pleochroic dyes and one or more compounds selected from the group of compounds of formulae I, II and III,

in which the parameters have the meaning indicated in Claim 1 , and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

First claim

The invention claimed is:

1. A liquid-crystal medium comprising:
one or more pleochroic compounds
one or more compounds selected from the group of compounds of formulae I, II and III

in which

L 11 denotes R 11 or X 11 ,
L 12 denotes R 12 or X 12 ,
R 11 and R 12 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 15 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms,
X 11 and X 12 , independently of one another, denote H, F, Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated or fluorinated alkoxyalkyl having 2 to 7 C atoms, and

independently of one another, denote

in which
L 21 denotes R 21 and, in the case where Z 21 and/or Z 22 denote trans-CH═CH— or trans-CF═CF—, alternatively denotes X 21 ,
L 22 denotes R 22 and, in the case where Z 21 and/or Z 22 denote trans-CH═CH— or trans-CF═CF—, alternatively denotes X 22 ,
R 21 and R 22 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17, C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15,
X 21 and X 22 , independently of one another, denote F or Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms,
one of
Z 21 and Z 22 denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and

independently of one another, denote

in which

L 31 denotes R 31 or X 31 ,
L 32 denotes R 32 or X 32 ,
R 31 and R 32 , independently of one another, denote 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,
X 31 and X 32 , independently of one another, denote H, F, Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, unfluorinated or fluorinated alkenyloxy or unfluorinated or fluorinated alkoxyalkyl having 2 to 7 C atoms,
Z 31 to Z 33 , independently of one another, denote trans-CH═CH—, trans —CF═CF—, —C≡C— or a single bond, and

independently of one another, denote

optionally one or more chiral compounds,
and
optionally one or more polymerisable compounds of formula P
P a —(Sp a ) s1 -(A 1 -Z 1 ) n1 -A 2 -Q-A 3 -(Z 4 -A 4 ) n2 -(Sp b ) s2 -P b   P

wherein the individual radicals have the following meanings:
P a , P b each, independently of one another, are a polymerisable group,
Sp a , Sp b each, independently of one another, denote a spacer group,
s1, s2 each, independently of one another, denote 0 or 1,
n1, n2 each, independently of one another, denote 0 or 1,
Q denotes a single bond, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —(CO)O—, —O(CO)—, —(CH 2 ) 4 —, —CH 2 —CH 2 —, —CF 2 —CF 2 —, —CF 2 —CH 2 —, —CH 2 —CF 2 —, —CH═CH—, —CF═CF—, —CF═CH—, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, —CH═CF—, —C≡C—, —O—, —CH 2 —, —(CH 2 ) 3 —, or —CF 2 —,
Z 1 , Z 4 denote a single bond, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —(CO)O—, —O(CO)—, —(CH 2 ) 4 —, —CH 2 —CH 2 —, —CF 2 —CF 2 —, —CF 2 —CH 2 —, —CH 2 —CF 2 —, —CH═CH—, —CF═CF—, —CF═CH—, —(CH 2 ) 3 O—, —O(CH 2 ) 3 —, —CH═CF—, —C≡C—, —O—, —CH 2 —, —(CH 2 ) 3 —, —CF 2 —, where Z 1 and Q or Z 4 and Q do not simultaneously denote a group selected from —CF 2 O— and —OCF 2 —,
A 1 , A 2 , A 3 , A 4
each, independently of one another, denote a diradical group selected from the following groups:
a) the group consisting of trans-1,4-cyclohexylene, 1,4-cyclohexenylene and 1,4′-bicyclohexylene, in which, in addition, one or more non-adjacent CH 2 groups may be replaced by —O— and/or —S— and in which, in addition, one or more H atoms may be replaced by F,
b) the group consisting of 1,4-phenylene and 1,3-phenylene, in which, in addition, one or two CH groups may be replaced by N and in which, in addition, one or more H atoms may be replaced by L,
c) the group consisting of tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, tetrahydrofuran-2,5-diyl, cyclobutane-1,3-diyl, piperidine-1,4-diyl, thiophene-2,5-diyl and selenophene-2,5-diyl, each of which may also be mono- or polysubstituted by L,
d) the group consisting of saturated, partially unsaturated or fully unsaturated, and optionally substituted, polycyclic radicals having 5 to 20 cyclic C atoms, one or more of which may, in addition, be replaced by heteroatoms,
where, in addition, one or more H atoms in these polycyclic radicals may be replaced by L,

and A 3 , alternatively may be a single bond,

L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF 5 or straight-chain or branched, in each case optionally fluorinated, alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C atoms.

2. A liquid-crystal medium according to claim 1 , wherein the one or more pleochroic compounds is an azo dye or a thiadiazol dye.

3. A liquid-crystal medium according to claim 2 , wherein said one or more optional chiral compounds has an absolute value of the helical twisting power (HTP) of 10 μm or more.

4. A liquid-crystal medium according to claim 1 , comprising one or more compounds of the formula I.

5. A liquid-crystal medium according to claim 1 , comprising one or more compounds of the formula II.

6. A liquid-crystal medium according to claim 1 , comprising one or more compounds of the formula III.

7. A liquid-crystal medium according to claim 1 , comprising a polymerizable compound of formula P and a polymerization initiator.

8. A composite system comprising a liquid crystal medium of claim 1 , wherein a polymer is obtained from the polymerisation of one or more compounds of formula P and one or more pleochroic compound and one or more compounds of formulae I to III.

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

10. A component according to claim 9 , wherein said component is operable in the microwave frequency range.

11. A component according to claim 9 , wherein said component is a phase shifter or a LC based antenna element operable in the microwave frequency region.

12. A method comprising including a liquid-crystal medium according to claim 1 in a component for high-frequency technology.

Assignees

• Merck Patent Gmbh

Inventors

• Wittek Michael
• Klass Dagmar
• Kirsch Peer

Classifications

• C08F222/1025

  of aromatic dialcohols · CPC title

• C09K19/16

  the chain containing carbon-to-carbon double bonds, e.g. stilbenes · CPC title

• C09K19/10

  containing at least two benzene rings · CPC title

• C09K19/3003

  Compounds containing at least two rings in which the different rings are directly linked (covalent bond) · CPC title

• C09K2019/163

  Ph-Ph-CH=CH-Ph · CPC title