Liquid-crystalline medium and liquid-crystal display

Patent metadata

Field	Value
Publication number	US-10738243-B2
Application number	US-201615202126-A
Country	US
Kind code	B2
Filing date	Jul 5, 2016
Priority date	Jul 3, 2015
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

The present invention relates to dielectrically positive liquid-crystalline media comprising one or more compounds of the formula I,

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

in which the parameters have the respective meanings indicated in the specification, and optionally one or more further dielectrically positive compounds and optionally one or more further dielectrically neutral compounds, and to liquid-crystal displays, especially active-matrix displays and in particular TN, IPS and FFS displays, containing these media.

First claim

The invention claimed is:

1. A liquid-crystal medium having positive dielectric anisotropy, which comprises
a) one or more compounds of the formula I,

in which
n denotes 1,
R 11 denotes H, F, Cl, a straight-chain or branched alkyl chain having 1-20 C atoms, in which one —CH 2 — group or a plurality of —CH 2 — groups may be replaced by —O—, —C(═O)— or

 but two adjacent —CH 2 — groups cannot be replaced by —O—, a hydrocarbon radical which contains a cycloalkanediyl unit or an alkylcycloalkanediyl unit, and in which one —CH 2 — group or a plurality of —CH 2 — groups may be replaced by —O— or —C(═O)—, but two adjacent —CH 2 — groups cannot be replaced by —O—,
R 12 denotes H, F, Cl, CN, CF 3 , OCF 3 or a straight-chain or branched alkyl chain having 1-20 C atoms, in which one —CH 2 — group or a plurality of —CH 2 — groups may be replaced by —O— or —C(═O)—, but two adjacent —CH 2 —groups cannot be replaced by —O—,
Y 1 denotes H, F, Cl, CN, CF 3 , OCF 3 or a straight-chain or branched alkyl chain having 1-20 C atoms, in which one —CH 2 — group or a plurality of —CH 2 — groups may be replaced by —O— or —C(═O)—, but two adjacent —CH 2 — groups cannot be replaced by —O—, and

 on each appearance, independently of one another, denotes

 where, in the case of cyclohexanediyl and in the case of the cyclohexenediyl units, one or more H atoms may also be replaced, independently of one another, by F, Cl or CN,

and
b) one or more compounds selected from the group of the compounds of the formulae II-2h, II-2k, III-2d, III-2e and III-2k

in which
R 2 and R 3 , 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,
L 21 , L 22 , L 23 , L 24 , L 25 , L 26 , L 31 , L 32 , L 33 , L 34 , L 35 and L 36 , independently of one another, denote H or F, and
X 2 and X 3 , independently of one another, denote halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms
and
one or more dielectrically neutral compounds of the formula V,

in which
R 51 and R 52 , independently of one another, have the meaning indicated for R 2 and R 3 ,

 on each occurrence, independently of one another, denotes

Z 51 and Z 52 , independently of one another and, if Z 51 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— or a single bond, and

r denotes 0, 1 or 2.

2. A medium according to claim 1 , which additionally comprises one or more compounds selected from the group of the compounds of the formulae II and III, other than a compound of formulae II-2h, II-2k, III-2d, III-2e and III-2k,

in which
R 2 and R 3 , 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,

on each appearance, independently of one another, denote

L 21 , L 22 , L 31 and L 32 , independently of one another, denote H or F,
X 2 and X 3 , independently of one another, denote halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms,
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
m and n, independently of one another, denote 0, 1, 2 or 3.

3. A medium according to claim 1 , which additionally comprises
one or more compounds of the formula IV

in which
R 41 and R 42 , independently of one another, have the meaning indicated for R 2 above claim 1 ,

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— or a single bond, and
p denotes 0, 1 or 2.

4. A medium according to claim 1 , wherein the total concentration of the compounds of the formula I in the medium is in the range from 1 ppm to 20,000 ppm.

5. A medium according to claim 1 , wherein the compounds of the formula I are compounds selected from the group of the compounds of the formula I-2,

in which the parameters have the meanings indicated in claim 1 under formula I.

6. A medium according to claim 2 , which comprises one or more compounds of the formula II.

7. A medium according claim 2 , which comprises one or more compounds of the formula III.

8. A liquid-crystal display, which contains a medium according to claim 1 .

9. A display according to claim 8 which is addressed by an active matrix.

10. A method which comprises including a medium according to claim 1 in a liquid-crystal display.

11. A process for the preparation of a medium according to claim 1 , wherein one or more compounds of the formula I, as given in claim 1 , are mixed with
one or more of the compounds of the formulae II-2h, II-2k, III-2d, III-2e and III-2k as given in claim 1 ,
one or more compounds of formula V as given in claim 1 and optionally
one or more further mesogenic compounds and/or
one or more additives.

12. A medium of claim 1 which comprises one or more compounds of the formula I, and one or more compounds selected from the group of the compounds of the formulae II-2h.

13. A medium of claim 1 which comprises one or more compounds of the formula I, and one or more

Assignees

• Merck Patent Gmbh

Inventors

• Junge Michael
• Reiffenrath Volker
• Montenegro Elvira
• Wittek Michael
• Czanta Markus

Classifications

• G02F1/137

  characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering · CPC title

• C09K19/30

  containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings · CPC title

• C09K19/3444

  the heterocyclic ring being a six-membered aromatic ring containing one nitrogen atom, e.g. pyridine · CPC title

• C09K19/345

  the heterocyclic ring being a six-membered aromatic ring containing two nitrogen atoms · CPC title

• C09K19/42 Primary

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