Liquid-crystalline medium and liquid-crystal display comprising the same

Patent metadata

Field	Value
Publication number	US-10364392-B2
Application number	US-201615161769-A
Country	US
Kind code	B2
Filing date	May 23, 2016
Priority date	May 21, 2015
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A liquid-crystalline medium having a nematic phase, a dielectric anisotropy of 0.5 or more and a ratio of the dielectric constant perpendicular to the director (ε ⊥ ) to the dielectric anisotropy (Δε), i.e. (ε ⊥ /Δε), of 2.0 or less and comprises one or more compounds of formula I:

wherein the parameters have the meaning given in the text. An electro-optical display containing such a medium, particularly in an active-matrix display based on the IPS or FFS effect. Methods for using of the compounds of formula I for improvement of the transmission and/or response times of a liquid-crystalline medium which comprises one or more additional mesogenic compounds.

First claim

The invention claimed is:

1. Liquid-crystalline medium having a nematic phase and a dielectric anisotropy (Δε, at a temperature of 20° C. and a frequency of 1 kHz) of 0.5 or more which comprises:
one or more compounds of formula I

in which

n denotes 0 or 1,
R 11 denotes R 1 ,
R 12 denotes X 1 ,
R 1 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, and
X l denotes F, Cl, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyoxy;

and
one or more compounds selected from the group of compounds of formulae II, III, IV and V:

in which
R 2 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl. alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,

on each appearance, independently of one another,

L 21 and L 22 denote H or F,
X 2 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms,
m denotes 0, 1, 2 or 3,
R 3 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms and

on each appearance, independently of one another, are

L 31 and L 32 , independently of one another, denote H or F,
X 3 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, F, Cl, —OCF 3 , —OCHF 3 , —O—CH 2 CF 3 , —O—CH═CF 2 ,—O—CH═CH 2 or —CF 3 ,
Z 3 denotes —CH 2 CH 2 —, —CF 2 CF 2 —, —COO—, trans-CH═CH—, trans-CF═CF—, —CH 2 O— or a single bond, and
n denotes 0, 1, 2 or 3,

in which
R 41 and R 42 , independently of one another, denote alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,

independently of one another and, if

 occurs twice,
also these independently of one another, denote

Z 41 and Z 42 , independently of one another and, if Z 41 occurs twice, also these independently of one another, denote —CH 2 CH 2 —, —COO—, trans -CH═CH—, trans-CF═CF—, -CH 2 O—, —CF 2 O—, —C≡C— a single bond,
P denotes 0, 1 or 2, and
R 51 and R 52 , independently of one another, have one of the meanings given for R 41 and R 42 ,

if present, each, independently of one another, denote

z 51 to Z 53 each, independently of one another, denote —CH 2 —CH 2 —, —CH 2 —O—, —CH═CH—, —C≡C—, —COO— a single bond, and
i and j each, independently of one another, denote 0 or 1;

with the condition that the ratio of the dielectric constant perpendicular to the director (ε ⊥ ) to the dielectric anisotropy (Δε), i.e. (ε ⊥ /Δε) of the medium, is 2.0 or less.

2. Liquid-crystalline medium having a nematic phase and a dielectric anisotropy (Δε, at a temperature of 20° C. and a frequency of 1 kHz) of 0.5 or more which comprises one or more compounds of formula I

in which

 denotes

 denotes

n denotes 1,
R 11 denotes R 1 ,
R 12 denotes X 1 ,
R 1 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, and
X 1 denotes F, Cl, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyoxy,
with the condition that the ratio of the dielectric constant perpendicular to the director (ε ⊥ ) to the dielectric anisotropy (Δε), i.e. (ε ⊥ /Δε) of the medium, is 2.0 or less.

3. Liquid-crystalline medium according to claim 1 , which has a ratio of the dielectric constant perpendicular to the director (ε ⊥ ) to the dielectric anisotropy (Δε), i.e. (ε ⊥ /Δε), of 1.5 or less.

4. Liquid-crystalline medium according to claim 1 , which has a ratio of the dielectric constant perpendicular to the director (ε ⊥ ) to the dielectric anisotropy (Δε), i.e. (ε ⊥ /Δε), of 1.0 or less.

5. Liquid-crystalline medium according to claim 1 , wherein the total concentration of the compounds of formula I in the medium as a whole is 1% or more to 60% or less by weight.

6. Liquid-crystalline medium according to claim 1 , which comprises one or more compounds selected from the group of compounds of formulae I-1

in which
R 11 and R 12 independently of each other denote alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms.

7. Liquid-crystalline medium according to claim 1 , which additionally comprises one or more chiral compounds.

8. Electro-optical display or electro-optical component which comprises a liquid-crystalline medium according to claim 1 .

9. Electro-optical display according to claim 8 , which is based on the IPS- or FFS mode.

10. Electro-optical display according to claim 8 , which contains an active-matrix addressing device.

11. Electro-optical display according to claim 8 , which is a mobile display.

12. Process for the preparation of a liquid-crystalline medium according to claim 1 , comprising mixing one or more compounds of formula I with one or more compounds selected from the group of compounds of formulae II, III, IV and V and with one or more additional mesogenic compounds.

Assignees

• Merck Patent Gmbh

Inventors

• Manabe Atsutaka
• Reiffenrath Volker
• Schuler Brigitte

Classifications

• G02F1/134363

  for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS] · CPC title

• C09K2019/3422

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

• C09K2019/3408

  Five-membered ring with oxygen(s) in fused, bridged or spiro ring systems · CPC title

• C09K2019/3025

  Cy-Ph-Ph-Ph · CPC title

• C09K2019/301

  Cy-Cy-Ph · CPC title