Liquid crystal medium and liquid crystal display

Patent metadata

Field	Value
Publication number	US-9120969-B2
Application number	US-201314030593-A
Country	US
Kind code	B2
Filing date	Sep 18, 2013
Priority date	Sep 18, 2012
Publication date	Sep 1, 2015
Grant date	Sep 1, 2015

Abstract

The instant invention relates to mesogenic media exhibiting a blue phase, comprising one, two or more compounds of formula I-A

wherein the parameters are as specified in the text, preferably stabilised by a polymer, and their use in electro-optical light modulation elements and their respective use in displays, as well as to such displays.

First claim

The invention claimed is:

1. Mesogenic medium exhibiting a blue phase, comprising at least one compound of formula I-A

wherein
R 1 is alkyl with 1 to 9 C-atoms, which is straight chain or branched, unsubstituted, mono- or poly-substituted by F, Cl or CN, and in which one or more CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NR 01 —, —SiR 01 R 02 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —CY 01 ═CY 02 — or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
L 11 and L 12 are, independently of each other, H or F,
Y 01 and Y 02 are, independently of each other, F, Cl or CN, and alternatively one of them may be H, and
R 01 and R 02 are, independently of each other, H or alkyl with 1 to 12 C-atoms.

2. Mesogenic medium according to claim 1 , which additionally comprises at least one chiral dopant.

3. Mesogenic medium according to claim 1 , which additionally comprises at least one compound of formulae I-T, I-N or I-E. . .

wherein
R 0 has the meaning given for R 1 in claim 1 ,
R 1 has the meaning given in claim 1 ,
n in each occurrence independently is 0 or 1 and
L 01 to L 03 and L 1 in each occurrence are independently of one another H or F.

4. Mesogenic medium according to claim 1 , which additionally comprises at least one compound of formula II

wherein
L 21 to L 23 are, independently of each other, H or F,
R 2 is alkyl, which is straight chain or branched, is unsubstituted, mono- or poly-substituted by F, Cl or CN, preferably by F, and in which one or more CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —NR 01 —, —SiR 01 R 02 —, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S—, —CY 01 ═CY 02 — or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
Y 01 and Y 02 are, independently of each other, F, Cl or CN, and alternatively one of them may be H,
R 01 and R 02 are, independently of each other, H or alkyl with 1 to 12 C-atoms.

5. Medium according to claim 1 , which additionally comprises at least one compound of formula III

wherein R 3 has the meaning given for R 1 in claim 1 .

6. Medium according to claim 1 , which additionally comprises at least one compound selected from the group of compounds of formulae IV and V

wherein
R 4 and R 5 are, independently of each other, alkyl, which is straight chain or branched, preferably has 1 to 20 C-atoms, is unsubstituted, mono- or poly-substituted by F, Cl or CN, preferably by F, and in which one or more CH 2 groups are optionally replaced, in each case independently from one another, by —O—, —S—, —CO—, —COO—, —OCO—, —OCO—O—, —S—CO—, —CO—S— or —C≡C— in such a manner that O and/or S atoms are not linked directly to one another,
L 5 is H or F,

 is

n and m are, independently of one another, 0 or 1.

7. Medium according to claim 1 , which comprises a polymerizable component, which comprises at least one polymerizable compounds.

8. Medium according to claim 1 , which additionally comprises at least one compound of formula M1

wherein the parameters have the following meanings:
P 1 and P 2 are each, independently of one another, a polymerisable group,
Sp 1 and Sp 2 are each, independently of one another, a single bond or a spacer group,
and, wherein alternatively also one or more of P 1 -Sp 1 - and P 2 -Sp 2 - may be R aa , provided that at least one of P 1 -Sp 1 - and P 2 -Sp 2 -present in the compound is not R aa ,
R aa is H, F, Cl, CN or linear or branched alkyl having 1 to 25 C-atoms, wherein one or more non-adjacent —CH 2 — groups, independently of each another, may be replaced by —C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a way that neither O- nor S-atoms are directly linked to one another, and wherein also one or more H-atoms may be replaced by F, Cl, CN or P 1 -Sp 1 -,
R 0 , R 00 are each, at each occurrence independently of one another, H or alkyl having 1 to 12 C-atoms,
L is at each occurrence independently of one another, F, Cl, CN, SCN, SF 5 or linear or branched, optionally mono- or poly-fluorinated, alkyl, alkoxy, alkenyl, alkinyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C-atoms, and
r is 0, 1, 2, 3 or 4.

9. Medium according to claim 1 , which additionally comprises at least one compound of formula M2

wherein the parameters have the following meanings
P 1 and P 2 are each, independently of one another, a polymerisable group,
Sp 1 and Sp 2 are each, independently of one another, a single bond or a spacer group,
and, wherein alternatively also one or more of P 1 -Sp 1 - and P 2 -Sp 2 - may be R aa , provided that at least one of P 1 -Sp 1 - and P 2 -Sp 2 -present in the compound is not R aa ,
R aa is H, F, Cl, CN or linear or branched alkyl having 1 to 25 C-atoms, wherein one or more non-adjacent —CH 2 — groups, independently of each another, may be replaced by —C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—O—, —O—CO—, —O—CO—O— in such a way that neither O- nor S-atoms are directly linked to one another, and wherein also one or more H-atoms may be replaced by F, Cl, CN or P 1 -Sp 1 -,
R 0 , R 00 are each, at each occurrence independently of one another, H or alkyl having 1 to 12 C-atoms,
L is at each occurrence independently of one another, F, Cl, CN, SCN, SF 5 or linear or branched, optionally mono- or poly-fluorinated, alkyl, alkoxy, alkenyl, alkinyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 12 C-atoms, and
r is 0, 1, 2, 3 or 4.

10. Method of stabilisation of a mesogenic medium wherein a medium according to claim 7 is subjected to polymerisation of its polymerisable constituents.

11. Mesogenic medium stabilised by the polymerisation of the polymerisable constituents of a medium according to claim 7 .

12. Light modulation element, characterized in that it comprises a medium according claim 1 .

13. Electro-optical display, characterized in that it comprises a medium according to claim 1 .

14. A method of using a medium according to claim 1 , comprising incorporating said medium in a light modulation element.

Assignees

• Merck Patent Gmbh

Inventors

• Wittek Michael
• Tanaka Norihiko
• Fischer Mila
• Bremer Matthias
• Durmaz Erdal
• Rillich Malgorzata

Classifications

• C09K19/0275

  Blue phase · CPC title

• C09K19/3469 Primary

  Pyrimidine with a specific end-group other than alkyl, alkoxy or -C*- · CPC title

• C09K2019/0448

  the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate · CPC title

• G02F1/13

  based on liquid crystals, e.g. single liquid crystal display cells · CPC title

• C09K19/20

  linked by a chain containing carbon and oxygen atoms as chain links, e.g. esters {or ethers} · CPC title