Liquid crystalline medium and liquid crystal device

Patent metadata

Field	Value
Publication number	US-9650573-B2
Application number	US-201414890733-A
Country	US
Kind code	B2
Filing date	Apr 22, 2014
Priority date	May 14, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

The present invention relates a liquid crystalline medium comprising one or more liquid crystalline compounds, one or more dichroic dyes, and one or more compounds capable of promoting or inducing homeotropic alignment to the adjacent liquid crystal medium at a given temperature selected from the group of compounds (A), having a three-dimensional structure, a molecular weight of greater than 450 Da, and one or more anchor groups, or the group of organic compounds (B) having one or more ring groups, and one or more anchor groups.
The invention furthermore relates to a temperature-reactive device for the regulation of light transmission, containing such liquid crystalline medium, and a process for the temperature-dependent control of light transmission through the layer of such liquid-crystalline medium.

First claim

The invention claimed is:

1. A medium comprising:
one or more liquid-crystalline compounds,
one or more dichroic dyes, and
one or more silsequioxane compounds (A) having a molecular weight of greater than 450 Da, wherein each compound (A) is a silsequioxane compound bonded to one or more anchor groups of the formula A-1, or
one or more organic compounds (B),

wherein said one or more anchor groups bonded to (A) are each of the formula A-1,
*-E-[X A1 —Z A1 ] a —X A2   A-1,

in which, in each case independently,
E represents a single bond or a spacer group;
X A1 is selected from —NH—, —NR A1 —, —O—and a single bond;
X A2 is selected from —NH 2 , —NHR A1 , NR A1 2 , —OR A1 and —OH;
Z A1 is selected from an alkylene group having 1-15 C atoms, a carbocyclic ring group having 5 or 6C atoms, or combinations of such groups, where the groups may in each case be substituted by OH, OR A1 , —NH 2 , —NHR A1 , —NR A1 2 or halogen;
R A1 is selected on each occurrence, identically or differently, from H, D, or an aliphatic, aromatic and/or heteroaromatic organic group having 1 to 30 C atoms, in which, in addition, one or more H atoms may be replaced by D or F;
a is equal to 0, 1, 2 or 3, and
* marks the bonding site of the anchor group to the silsequioxane; and
wherein organic compounds compound (B) are each of the formula B-I,
R B1 -A B1 -(Z B1 -A B2 ) m -R B2   B-I,

wherein,
A B1 and A B2 each, independently of one another, denote an aromatic, heteroaromatic, alicyclic or heterocyclic group, which may also contain fused rings, and which may also be mono- or polysubstituted by a group L,
L in each case, independently of one another, denotes OH, (CH 2 ) n —OH, F, Cl, Br, I, CN, —NO 2 , —NCO, —NCS, OCN, SCN, —C(═O)N(R 0 ) 2 , C(═O)R 0 , —N(R 0 ) 2 , —(CH 2 ) n —N(R 0 ) 2 , optionally substituted silyl, optionally substituted aryl or cycloalkyl having 6 to 20 C atoms, or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having up to 25 C atoms, in which, in addition, one or more H atoms are each optionally replaced by F or Cl,
Z B1 in each case, independently of one another, denotes —O—, S, —CO—, CO—O—, OCO—, —O—CO—O—, OCH 2 —, CH 2 O—, SCH 2 , —CH 2 S—, CF 2 O—, OCF 2 —, CF 2 S—, —SCF 2 —, (CH 2 ) n —, CF 2 CH 2 —, CH 2 CF 2 —, (CF 2 ) n —, CH═CH—, CF═CF—, C≡C—, CH═CH—COO—, OCO—CH═CH—, CR 0 R 00 or a single bond,
R 0 and R 00 each, independently of one another, denote H or alkyl having 1to 12 C atoms,
R B1 denotes H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which, in addition, one or more non-adjacent CH 2 groups are each optionally replaced by —NR 0 —,—O—, —S—,—CO—, CO—O—, —O—CO—, or —O—CO—O— in such a way that N, O and/or S atoms are not linked directly to one another, and in which, in addition, one or more tertiary CH groups are each optionally replaced by N, and in which, in addition, one or more H atoms are each optionally replaced by F or Cl,
R B2 denotes, a straight-chain, branched or cyclic alkyl group or aryl group having 1 to25 C atoms, in which, in addition, one or more non-adjacent CH 2 groups are each optionally replaced by —NR 0 —, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O—in such a way that N, O and/or S atoms are not linked directly to one another, and in which, in addition, one or more tertiary CH groups are each optionally replaced by N, and in which, in addition, one or more H atoms are each optionally replaced by F or Cl, with the proviso that the radical R B2 contains one or more heteroatoms selected from N, S and/or O,
m denotes 0, 1, 2, 3, 4 or 5, and
n denotes 1, 2, 3 or 4.

2. The medium according to claim 1 , wherein compound (A) has a diameter of 1 nm to 100 nm.

3. The medium according to claim 1 , wherein group R B2 is of the formula CG,
-Sp-[X B1 —Z B2 —] k X B2   CG

wherein,
Sp denotes a spacer group or a single bond,
X B1 in each case independently denotes —NH—, —NR 0 —, —O—or a single bond, X B2 denotes a group —NH 2 , —NHR 0 , —NR 0 2 , —OR 0 , —OH, —(CO)OH or a group of the formula

Z B2 in each case independently denotes an alkylene group having 1-15 C atoms, a carbocyclic ring having 5 or 6 C atoms, or combinations of one or more rings and one or more alkylene groups, in each of which one or more H atoms are each optionally replaced by —OH, —OR 0 , —(CO)OH, —NH 2 , —NHR 0 , —NR 0 2 or halogen,
R 0 has in each occurrence, each and independently one of meanings as indicated under formula B-I, and
k denotes 0, 1, 2 or 3.

4. The medium according to claim 1 , wherein the dichroic dye is selected from perylene dyes, anthrachinone dyes, and azo dyes.

5. The medium according to claim 1 , wherein the dichroic dye is selected from the compounds of formula I,

wherein,

 to

are at each occurrence , identically or differently , selected from

and, in case i is 2 or more, the terminal one of group

may also be

and in case j is 2 or more, the terminal one of group

may also be

Z 11 and Z 12 are, independently of each other, —N═N—, —OCO— or —COO—,
R 11 and R 12 are, independently of each other, alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl, alkylaminyl, dialkylaminyl, alkylcarbonyl, alkyloxycarbonyl, alkylcarbonyloxy, alkyloxycarbonyloxy or alkylcyclohexylalkyl, and
i and j are independently of each other 1, 2, 3 or 4.

6. The medium according to claim 1 , wherein said one or more compounds (A) or said one or more compounds (B) are in a concentration between 0.5 and 10% by weight, with regards to the medium as a whole.

7. A process for the production of a medium according to claim 1 , comprising mixing at least one liquid-crystalline compound, with at least one dichroic dye, and with at least one compound (A) or (B).

8. An electro-optical or temperature-reactive device comprising a layer of liquid crystalline medium according to claim 1 , wherein said medium has a boundary state A and the liquid crystalline compounds in the layer of liquid crystalline medium in boundary state A are homeotropically aligned.

9. An electro-optical or temperature-reactive device, comprising a medium of claim 1 .

10. A temperature-reactive device for regulation of light transmission comprising a layer of a medium according to claim 1 .

11. The device according to claim 10 , wherein the layer of the medium is arranged directly adjacent between two substrate layers.

12. The device according to claim 10 , wherein

Assignees

• Merck Patent Gmbh

Inventors

• Archetti Graziano
• Junge Michael
• Wu Ming-Chou

Classifications

• C09K19/601 Primary

  Azoic · CPC title

• C09K2019/3422

  the heterocyclic ring being a six-membered ring · CPC title

• C09K19/42

  Mixtures of liquid crystal compounds covered by two or more of the preceding groups C09K19/06 - C09K19/40 · CPC title

• C09K2019/3004

  Cy-Cy · CPC title

• G02F1/132

  Thermal activation of liquid crystals exhibiting a thermo-optic effect · CPC title