Liquid crystal medium

Patent metadata

Field	Value
Publication number	US-9487702-B2
Application number	US-201414483222-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Sep 12, 2013
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The present invention relates to a liquid crystal (LC) medium comprising a polymerizable compound, to a process for its preparation, to its use for optical, electro-optical and electronic purposes, in particular in an LC display, especially in an LC display of the PSA (“polymer sustained alignment”) type, and to an LC display comprising the LC medium.

First claim

The invention claimed is:

1. A liquid crystal (LC) medium comprising one or more polymerizable compounds of formula I

in which the individual radicals have the following meanings
m is 0 or 1,
P 1 , P 2 , P 3 independently of each other denote a polymerizable group,
Sp 1 , Sp 2 , Sp 3 independently of each other denote a spacer group or a single bond, wherein at least one of Sp 1 , Sp 2 and Sp 3 is different from a single bond,
L denotes P-Sp-, F, Cl, Br, I, —CN, —NO 2 , —NCO, —NCS, —OCN,—SCN, —C(═O)N(R x ) 2 , —C(═O)Y 1 , —C(═O)R x , —N(R x ) 2 , optionally substituted silyl, optionally substituted aryl or heteroaryl having 5 to 20 ring atoms, or straight-chain or branched alkyl having 1 to 25, particularly preferably 1 to 10, C atoms, in which, in addition, one or more non-adjacent CH 2 groups are each optionally replaced, independently of one another, by —C(R 00 )═C(R 000 )—, —C≡C—,—N(R 00 )—, —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, in addition, one or more H atoms are each optionally replaced by F, Cl, CN or P-Sp-,
Y 1 is halogen,
R 00 and R 000 each, independently of one another, denote H or alkyl having 1 to 12 C atoms,
r is 0, 1, 2 or 3,
R x denotes P-Sp-, H, halogen, straight chain, branched or cyclic alkyl having 1 to 25 C atoms, wherein one or more non-adjacent CH 2 —groups are each optionally replaced by —O—, —S—, —CO—, —CO—O—, —O—CO—, or —O—CO—O— in such a manner that O—and/or S-atoms are not directly connected with each other, and wherein one or more H atoms are each optionally replaced by F, Cl or P-Sp-, optionally substituted aryl, aryloxy, heteroaryl or heteroaryloxy having 5 to 20 ring atoms,
P has one of the meanings given for P 1 ,
Sp has one of the meanings given for Sp 1 or Sp 2 ; and
further comprising one or more mesogenic or liquid crystalline compounds comprising an alkenyl group.

2. The LC medium of claim 1 , wherein P, P 1 , P 2 and P 3 in formula I are each selected from acrylate, methacrylate and oxetane.

3. The LC medium of claim 1 , wherein in the compounds of formula I
those groups Sp 1 , Sp 2 and Sp 3 that are not a single bond are selected from *—(CH 2 ) p1 —, *—CH 2 ) p2 —O—(CH 2 ) p3 —, *—(CH 2 ) p2 —S—(CH 2 ) p3 —, *—(CH 2 ) p2 —NH—(CH 2 ) p3 —,*—(CH 2 ) p1 —O—,*—(CH 2 ) p1 —CO—, *—(CH 2 ) p1 —CO—O—,*—(CH 2 ) p1 —O—CO— and

wherein the asterisk (*) denotes the link to the respective polymerizable group(s),
p1 is an integer from 1 to 12, and
p2 and p3 are, independently of each other, an integer from 1 to 6.

4. The LC medium of claim 1 , wherein in the compounds of formula I at least one of the benzene rings is substituted by one or two fluorine atoms.

5. The LC medium of claim 1 , wherein the compounds of formula I are selected from the following subformulae:

wherein P 1 , P 2 , P 3 , Sp 1 , Sp 2 , Sp 3 , L and r have the meanings given in claim 1 .

6. The LC medium of claim 1 , wherein the compounds of formula I are selected from the following subformulae:

wherein
P 1 , P 2 and P 3 have the meanings given in claim 1 ,
X is on each occurrence identically or differently —O—, —CO—O—,—O—CO— or a single bond, and
m and n are independently of each other 0, 1, 2, 3, 4, 5 or 6, and one of m and n is different from 0.

7. The LC medium of claim 1 , wherein in said mesogenic or liquid crystalline compounds comprising an alkenyl group, said alkenyl group is a straight-chain alkenyl having 2 to 7 C atoms and cyclohexenyl.

8. The LC medium of claim 7 , wherein the concentration of said mesogenic or liquid crystalline compounds comprising an alkenyl group is from 5% to 100%.

9. The LC medium of claim 1 , wherein the mesogenic or liquid crystalline compounds containing an alkenyl group are selected from the following formulae:

in which the individual radicals, on each occurrence identically or differently, each, independently of one another, have the following meanings:

R 11 is alkenyl having 2 to 9 C atoms or, if at least one of the rings X, Y and Z denotes cyclohexenyl, is alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH 2 groups are each optionally replaced by —O—, —CH═CH—, —CO—,—OCO— or —COO— in such a way that O atoms are not linked directly to one another,
R 12 alkyl having 1 to 12 C atoms, in which, in addition, one or two non-adjacent CH 2 groups are each optionally replaced by —O—, —CH═CH—, —CO—, —OCO or —COO— in such a way that O atoms are not linked directly to one another,
Z x —CH 2 CH 2 —,—CH═CH—,—CF 2 O—,—OCF 2 , —CH 2 O—, —OCH 2 —,—CO—O—, —O—CO—,—C 2 F 4 , —CF═CF—,—CH═CH—CH 2 O—, or a single bond,
L 1-4 each, independently of one another, H, F, Cl, OCF 3 , CF 3 , CH 3 , CH 2 F or CHF 2 H,
x 1 or 2,
z 0 or 1.

10. The LC medium of claim 1 , wherein the mesogenic or liquid crystalline compounds containing an alkenyl group are selected from the following formulae:

in which
alkyl and alkyl* each, independently of one another, denote a straight-chain alkyl radical having 1-6 C atoms, and
alkenyl and alkenyl* each, independently of one another, denote a straight-chain alkenyl radical having 2-7 C atoms.

11. The LC medium of claim 1 , wherein the mesogenic or liquid crystalline compounds containing an alkenyl group are selected from the following formulae:

in which
alkyl and alkyl* each, independently, denote a straight-chain alkyl radical having 1-6 C atoms, and
alkenyl denotes a straight-chain alkenyl radical having 2-7 C atoms.

12. The LC medium of claim 1 , wherein the mesogenic or liquid crystalline compounds containing an alkenyl group are selected from the following formulae:

in which
m denotes 1, 2, 3, 4, 5 or 6,
i denotes 0, 1, 2 or 3, and
R b1 denotes H, CH 3 or C 2 H 5 .

13. The LC medium of claim 1 , wherein the mesogenic or liquid crystalline compounds containing an alkenyl group are selected from the following formulae:

Assignees

• Merck Patent Gmbh

Inventors

• Baron Eveline
• Vogt Julian
• Tong qiong
• Derow Stephan

Classifications

• G02F1/1337

  Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers · CPC title

• C09K2019/3016

  Cy-Ph-Ph · CPC title

• C09K2019/0466

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

• C09K19/3066 Primary

  in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers · CPC title

• C09K19/3098

  Unsaturated non-aromatic rings, e.g. cyclohexene rings · CPC title