Liquid crystal medium and liquid display

Patent metadata

Field	Value
Publication number	US-10450509-B2
Application number	US-201214122096-A
Country	US
Kind code	B2
Filing date	May 9, 2012
Priority date	Jun 1, 2011
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

Mesogenic media comprising one or more compounds of formulae I or II

preferably mesogenic media showing a blue phase, preferably stabilized by a polymer, and their use in electro-optical light modulation elements and their respective use in displays, as well as such devices.

First claim

The invention claimed is:

1. A mesogenic medium comprising (1) 40-80% by weight of four compounds of formula I, and 4 to 8% by weight of two compounds of formula II-3

wherein

L 1 is F,
R 1 and R 2 are, independently of each other, straight chain or branched alkyl having 1-20 C atoms 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—, —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, (2) one or more polymerizable compounds that is a reactive mesogen of the formula RM-C

a reactive mesogenic compound of the formula RM-1

or RM-2

(3) one or more compounds of formula III

wherein R 3 has the meaning given for R 1 , (4)
one or more compounds of formula IV

wherein R 4 is alkyl with 1-20 C atoms, which is straight chain or branched, is 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—, —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,

and
n is 1, and
(5) two compounds of formula V

wherein
R 5 is alkyl with 1-20 C atoms, which is straight chain or branched, is 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—, —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 F,
and m is 0
said medium containing a chiral dopant which produces, in the medium, a blue phase, of the formula

2. A method of stabilization of a mesogenic medium, comprising subjecting a medium according to claim 1 to polymerization of its polymerizable constituents.

3. A mesogenic medium stabilized by the polymerization of polymerizable constituents of a medium according to claim 1 .

4. A light modulation element, comprising a medium according to claim 1 .

5. An electro-optical display, comprising a medium according to claim 1 .

6. The medium according to claim 1 , wherein R 1 and R 2 are each independently alkyl substituted by F.

7. The medium according to claim 1 , wherein R 4 and R 5 are each independently alkyl substituted by F.

Assignees

• Wittek Michael
• Tanaka Norihiko
• Rillich Malgorzata
• Reiffenrath Volker
• Jansen Axel
• Merck Patent Gmbh

Inventors

• Wittek Michael
• Tanaka Norihiko
• Rillich Malgorzata
• Reiffenrath Volker
• Jansen Axel

Classifications

• C09K19/20 Primary

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

• C09K2019/0448

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

• C09K19/12

  at least two benzene rings directly linked, e.g. biphenyls · CPC title

• C09K19/44

  containing compounds with benzene rings directly linked · CPC title

• C09K2019/0466

  the linking chain being a -CF2O- chain · CPC title