Liquid-crystal displays and liquid-crystalline media having homeotropic alignment

Patent metadata

Field	Value
Publication number	US-9726933-B2
Application number	US-201314652568-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Dec 17, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The present invention relates to liquid-crystalline media (LC media) having negative or positive dielectric anisotropy comprising self-alignment additives (SAMs) with an at least one bifunctional or polyfunctional anchor group, which effects the homeotropic (vertical) alignment of the LC media at a surface or the cell walls of a liquid-crystal display (LC display). The invention therefore also encompasses LC displays having homeotropic alignment of the liquid-crystalline medium (LC medium) without conventional imide alignment layers. The LC media may be supplemented by a polymerizable or polymerized component, which serves for stabilization of the alignment, for adjustment of the tilt angle and/or as passivation layer.

First claim

The invention claimed is:

1. A LC medium comprising a low-molecular-weight liquid-crystalline mixture and one or more self-aligning additives of formula I:
R 1 -A 1 -(Z 2 -A 2 ) m1 -R 2   (I)

R 2 denotes a group

Sp 1 , Sp 3 , Sp 5 independently of each other, denotes a spacer group or a single bond,
Sp 2 denotes a trivalent, acyclic spacer group,
Sp 4 denotes a tetravalent, acyclic spacer group,
Y is independently of each other O, S, (CO), NR 0 or a single bond,
X 1 and X 2 independently of each other a group —OH, —NH 2 , —NHR 11 , —SH, —SR 11 , —NR 11 2 , —OR 11 or —(CO)OH,

R 11 in each case independently denotes a halogenated or unsubstituted alkyl chain having 1 to 15 C atoms, in which one or more CH 2 groups are each optionally replaced, independently of one another, by —C≡C—, —CH═CH—, —(CO)O—, —O(CO)—, —(CO)— or —O— in such a way that O or N atoms are not linked directly to one another, and where two radicals R 11 are optionally linked to one another to form a ring,
B a ring or condensed ring, optionally substituted by one, two or three R L ,
p is 2, 3, 4 or 5,
A 1 and A 2 each, independently of one another, denote an aromatic, heteroaromatic, alicyclic or heterocyclic group, which optionally contains fused rings, and which is optionally mono- or polysubstituted by R L ,
R L in each case, independently of one another, denotes OH, SH, SR 0 , —(CH 2 ) n1 —OH, F, Cl, Br, I, —CN, —NO 2 , —NCO, —NCS, —OCN, —SCN, —C(═O)N(R 0 ) 2 , —C(═O)R 0 , —N(R 0 ) 2 , —(CH 2 ) n1 —N(R 0 ) 2 , optionally substituted silyl, optionally substituted aryl or cycloalkyl having 6 to 20 C atoms, or straight-chain or branched alkyl, alkoxy, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy having 1 to 25 C atoms, in which one or more H atoms are optionally replaced by F or Cl, and two vicinal R L together are optionally ═O,
n1 denotes 1, 2, 3, 4 or 5,
Z 2 in each case, independently of one another, denotes a single bond, —O—, —S—, —CO—, —CO—O—, —OCO—, —O—CO—O—, —OCH 2 —, —CH 2 O—, —SCH 2 —, —CH 2 S—, —CF 2 O—, —OCF 2 —, —CF 2 S—, —SCF 2 —, —(CH 2 ) n1 —, —CF 2 CH 2 —, —CH 2 CF 2 —, —(CF 2 ) n1 —, —CH═CH—, —CF═CF—, —C≡C—, —CH═CH—COO—, —OCO—CH═CH— or CR 0 R 00 ,
R 0 and R 00 each, independently of one another, denote H or alkyl having 1 to 12 C atoms,
R 1 denotes H, halogen, straight-chain, branched or cyclic alkyl having 1 to 25 C atoms, in which one or more non-adjacent CH 2 groups are optionally replaced by —C≡C, —CH═CH, —NR 0 —, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a way that N, O and/or S atoms are not linked directly to one another, and in which one or more tertiary carbon atoms (CH groups) are optionally replaced by N, and in which one or more H atoms are optionally replaced by F or Cl, and
m1 denotes 0, 1, 2, 3, 4 or 5.

2. The LC medium according to claim 1 , further comprising a polymerizable or polymerized component, where the polymerized component is obtainable by polymerization of a polymerizable component.

3. The LC medium according to claim 1 , wherein in the compound of formula I, m1 is 1, 2 or 3.

4. The LC medium according to claim 1 , wherein, in the compound of formula I, R 2 contains two or three hydroxy groups.

5. The LC medium according to claim 1 , wherein in the compound of formula I, R 2 comprises two groups X 1 or two groups X 2 .

6. The LC medium according to claim 1 , wherein, in the compound of formula I, A 1 and A 2 , if present, are independently 1,4-phenylene and/or cyclohexane-1,4-diyl, which are all optionally substituted by R L .

7. The LC medium according to claim 1 , wherein, in the compound of formula I,
Sp 2 is CH, CR 0 or N,
Sp 4 is C, and

denotes a benzene ring.

8. The LC medium according to claim 1 , wherein in the compound of formula I
R 2 denotes

in which Y, X 1 , X 2 , Sp 1 and Sp 3 are independently defined as for the compound of formula I, and
n independently denotes 1, 2, 3 or 4.

9. The LC medium according to claim 1 , comprising one or more compounds of the following formulae:

wherein R 1 , R L and p are independently defined as for the compound of formula I.

10. The LC medium according to claim 1 , comprising the one or more compounds of formula I in a concentration of less than 1% by weight.

11. The LC medium according to claim 1 , comprising one or more polymerizable compounds or a polymerized component, which comprises one or more compounds in polymerized form, wherein the one or more polymerizable compounds are of the following formulae:

wherein
P 1 and P 2 each, independently of one another, denote a polymerisable group,
Sp 1 and Sp 2 each, independently of one another, denote a single bond or a divalent spacer group, where, in addition, one or more of the radicals P 1 -Sp 1 - and P 2 —Sp 2 - optionally denote a radical R aa , with the proviso that at least one of the radicals P 1 -Sp 1 - and P 2 —Sp 2 - present does not denote R aa ,
R aa denotes H, F, Cl, CN or straight-chain or branched alkyl having 1 to 25 C atoms, in which one or more non-adjacent CH 2 groups are each optionally replaced, independently of one another, by C(R 0 )═C(R 00 )—, —C≡C—, —N(R 0 )—, —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a way that O and/or S atoms are not linked directly to one another, and in which one or more H atoms are optionally replaced by F, Cl, CN or P 1 —Sp 1 -,
R 0 , R 00 each, independently of one another, denote H or alkyl having 1 to 12 C atoms,
R y and R z each, independently of one another, denote H, F, CH 3 or CF 3 ,
Z 1 denotes —O—, —CO—, —C(R y R z )— or —CF 2 CF 2 —,
Z 2 and Z 3 each, independently of one another, denote —CO—O—, —O—CO—, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 — or —(CH 2 )—, where n is 2, 3 or 4,
L on each occurrence, identically or differently, denotes F, Cl, CN, SCN, SF 5 or straight-chain or branched, optionally mono- or polyfluorinated alkyl, alkoxy, alkenyl, alkynyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy or alkoxycarbonyloxy h

Assignees

• Merck Patent Gmbh

Inventors

• Archetti Graziano
• Taugerbeck Andreas
• Bender Renate
• Fortte Rocco
• Kirsch Peer
• Saito Izumi

Classifications

• C09K19/063 Primary

  containing one non-condensed saturated non-aromatic ring, e.g. cyclohexane ring · CPC title

• C09K2019/304

  Cy-C2H4-Ph-Ph · CPC title

• C09K2019/3016

  Cy-Ph-Ph · CPC title

• G02F1/134363

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

• C09K19/3003

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