Liquid-crystalline medium, method for the stabilization thereof, and liquid-crystal display

Patent metadata

Field	Value
Publication number	US-10465117-B2
Application number	US-201314056120-A
Country	US
Kind code	B2
Filing date	Oct 17, 2013
Priority date	Oct 18, 2012
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

Compounds of the formula I, and a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises
a) one or more compounds of the formula I

and
b) one or more compounds of the formula II

in which the parameters have the respective meanings indicated in Claim 1 . The use thereof in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect. Displays of this type which contain a liquid-crystalline medium of this type. Use of the compounds of the formula I for the stabilization of a liquid-crystalline medium which comprises one or more compounds of the formula II.

First claim

The invention claimed is:

1. Liquid-crystalline medium comprising
a) one or more compounds of the formulae I-1a-2, I-1a-3 or I-1a-5:

and
b) one or more compounds of the formula II

in which
R 21 denotes an unsubstituted alkenyl radical having 2 to 7 C atoms,
R 22 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms,

p and q each, independently of one another, denote 0, 1 or 2, and
p+q denotes 1, 2 or 3.

2. A liquid-crystalline medium according to claim 1 , which comprises one or more compounds of the formula II selected from the group of the compounds of the formulae II-1 to II-4

in which the parameters have the respective meanings given in claim 1 .

3. A liquid-crystalline medium according to claim 1 , which additionally comprises
c) one or more compounds selected from the group of the compounds of the formulae III-1 to III-4

in which
R 31 denotes an unsubstituted alkyl radical having 1 to 7 C atoms,
R 32 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, and
m, n and o each, independently of one another, denote 0 or 1.

4. A liquid-crystalline medium according to claim 1 , wherein the total concentration of the compounds of the formulae I-1a-2, I-1a-3 and I-1a-5 in the medium as a whole is 1 ppm or more to 1000 ppm or less.

5. A liquid-crystalline medium according to claim 1 , which additionally comprises
d) one or more compounds of the formula IV,

in which
R 41 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkenyl radical having 2 to 7 C atoms, and
R 42 denotes an unsubstituted alkyl radical having 1 to 7 C atoms, an unsubstituted alkoxy radical having 1 to 6 C atoms, or an unsubstituted alkenyl radical having 2 to 7 C atoms.

6. A liquid-crystalline medium according to claim 1 , wherein the total concentration of the compounds of the formula II in the medium as a whole is 25% or more to 45% or less.

7. A liquid-crystalline medium according to claim 2 , which comprises one or more compounds of the formula II-3.

8. A liquid-crystalline medium according to claim 1 , which additionally comprises one or more chiral compounds.

9. An electro-optical display or electro-optical component, which comprises a liquid-crystalline medium according to claim 1 .

10. An electro-optical display according to claim 9 , which is based on the VA or ECB effect.

11. An electro-optical display according to claim 9 , which contains an active-matrix addressing device.

12. Process for the preparation of a liquid-crystalline medium according to claim 1 , comprising mixing one or more compounds of the formulae I-1a-2, I-1a-3 and/or I-1a-5 with one or more compounds of the formula II.

13. A liquid-crystalline medium, according to claim 1 , further comprising one or more compounds selected from the group of the compounds of the formulae OH-1 to OH-6

14. Process for the preparation of a liquid-crystalline medium according to claim 3 , comprising mixing one or more compounds of the formulae I-1a-2, I-1a-3 and/or I-1a-5 with one or more compounds of the formula II and one or more compounds selected from the group of the compounds of the formulae III-1 to III-4.

15. Process for the preparation of a liquid-crystalline medium according to claim 5 , comprising mixing one or more compounds of the formulae I-1a-2, I-1a-3 and I-1a-5 with one or more compounds of the formula II and one or more compounds of the formula IV.

16. A liquid-crystalline medium according to claim 1 , which comprises one or more compounds selected from the group of the compounds of the formula I-1a-2.

17. A liquid-crystalline medium according to claim 1 , which comprises one or more compounds selected from the group of the compounds of the formula I-1a-3.

18. A liquid-crystalline medium according to claim 1 , which comprises one or more compounds selected from the group of the compounds of the formula I-1a-5.

19. An electro-optical display, wherein the display is based on the VA or ECB effect, and wherein the display comprises a liquid-crystalline medium which medium comprises:
a) one or more compounds of the formulae I-1a-1, I-1a-2, I-1a-3 or I-1a-5:

and
b) one or more compounds of the formula II

in which
R 21 denotes an unsubstituted alkenyl radical having 2 to 7 C atoms,
R 22 denotes an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms,

p and q each, independently of one another, denote 0, 1 or 2, and
p+q denotes 1, 2 or 3.

20. An electro-optical display according to claim 19 , wherein the liquid-crystalline medium comprises one or more compounds selected from the group of the compounds of the formula I-1a-1.

Assignees

• Merck Patent Gmbh

Inventors

• Goebel Mark
• Baron Eveline
• Fortte Rocco
• Pauluth Detlef

Classifications

• C09K19/42

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

• C09K19/3003

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

• C09K19/12

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

• C09K2019/3016

  Cy-Ph-Ph · CPC title

• C09K2019/301

  Cy-Cy-Ph · CPC title