Mesogenic media and liquid crystal display

Patent metadata

Field	Value
Publication number	US-10087370-B2
Application number	US-201314403417-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	May 25, 2012
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

The invention relates to mesogenic media comprising
a first component, component A, consisting of bimesogenic compounds selected from the group of compounds of formulae A-I to A-III

a second component, component B, consisting of nematogenic compounds, preferably selected from the group of compounds of formulae B-I to B-III

and
a third component, component C, consisting of one or more chiral molecules,
wherein the parameters have the meaning given in claim 1 , to the use of mesogenic media in flexoelectric liquid crystal devices and to those devices comprising a liquid crystal medium according to the present invention.

First claim

The invention claimed is:

1. A mesogenic medium comprising
a first component, component A, consisting of bimesogenic compounds selected from the group consisting of compounds of formulae A-I, A-II and A-III, wherein at least one compound of formula A-II and at least one compound of formula A-III are present in component A,

wherein
R 11 and R 12 ,
R 21 and R 22 and
R 31 and R 32 are each independently H, F, Cl, CN, NCS or a straight-chain or branched alkyl group with 1 to 25 C atoms which is unsubstituted, or mono- or polysubstituted by halogen or CN, in which optionally one or more non-adjacent CH 2 groups are replaced, in each occurrence independently from one another, by —O—, —S—, —NH—, —N(CH 3 )—, —CO—, —COO—, —OCO—, —O—CO—O—, —S—CO—, —CO—S—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C— in such a manner that oxygen atoms are not linked directly to one another,
MG 11 and MG 12 ,
MG 21 and MG 22 and
MG 31 and MG 32 are each independently a mesogenic group,
Sp 1 , Sp 2 and Sp 3 are each independently a spacer group comprising 5 to 40 C atoms, wherein one or more non-adjacent CH 2 groups, with the exception of the CH 2 groups of Sp 1 linked to O-MG 11 and/or O-MG 12 , of Sp 2 linked to MG 21 and/or MG 22 and of Sp 3 linked to X 31 and X 32 , are optionally replaced by —O—, —S—, —NH—, —N(CH 3 ) —, —CO—, —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O—, —CH(halogen)-, —CH(CN) —, —CH═CH— or —C≡C—, in such a way that no two O-atoms are adjacent to one another, no two —CH═CH— groups are adjacent to each other, and no two groups selected from the group consisting of —O—CO—, —S—CO—, —O—COO—, —CO—S—, —CO—O— and —CH═CH— are adjacent to each other, and
X 31 and X 32 are independently from one another a linking group selected from the group consisting of —CO—O—, —O—CO—, —CH═CH—, —C≡C— and —S—, and wherein alternatively one of X 31 and X 32 is —O— or a single bond, or one of X 31 and X 32 is —O— and the other one is a single bond,

wherein the medium comprises component A in a concentration of 60 to 90% by weight of the medium,
a second component, component B, consisting of one or more nematogenic compounds, which are of formulae B-I to B-III

wherein
L B11 , L B12 , L B31
and L B32 are independently H or F,
B B1 , R B21 , R B22 ,
R B31 and R B32 are each independently H, F, Cl, CN, NCS or a straight-chain or branched alkyl group with 1 to 25 C atoms which is optionally unsubstituted, mono- or polysubstituted by halogen or CN, in which optionally one or more non-adjacent CH 2 groups are replaced, in each occurrence independently from one another, by —O—, —S—, —NH—, —N(CH 3 )—, —CO—, —COO—, —OCO—, —O—CO—O—, —S—CO—, —CO—S—, —CH═CH—, —CH═CF—, —CF═CF— or —C≡C— in such a manner that oxygen atoms are not linked directly to one another,
X B1 is F, Cl, CN or NCS,
Z B1 ,Z B2 and Z B3 are in each occurrence independently —CH 2 —CH 2 —, —CO—O—, —O—CO—, —CF 2 —O—, —O—CF 2 —, —CH═CH— or a single bond,

 and

 are in each occurrence independently

 or

or alternatively one or more of
 are

 and
n is 1, 2 or 3,
and a third component, component C, consisting of one or more chiral molecules, which are of formulae C-I to C-III,

including the respective (S,S) enantiomers,
wherein
E and F are each independently 1,4-phenylene or trans- 1,4-cyclohexylene,
v is 0 or 1,
Z 0 is —COO—, —OCO—, —CH 2 CH 2 — or a single bond, and
R is alkyl, alkoxy or alkanoyl with 1 to 12 C atoms.

2. The mesogenic medium according to claim 1 , comprising one or more compounds of formulae A-I to A-III, wherein MG 11 and MG 12 , MG 21 and MG 22 and MG 31 and MG 32 are independently of each other of formula II
-A 1 -(Z 1 -A 2 ) m -  II

wherein
Z 1 is —COO—, —OCO—,—O—CO—O—, —OCH 2 —, —CH 2 O—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —CF 2 CF 2 —, —CH═CH—, —CF═CF—, —CH═CH—COO—, —OCO—CH═CH—, —C≡C— or a single bond,
A 1 and A 2 are each independently in each occurrence 1,4-phenylene, in which one or more CH groups are optionally replaced by N, trans- 1,4-cyclohexylene, in which one or two non-adjacent CH 2 groups are optionally replaced by O and/or S, 1,4—cyclohexenylene, 1,4-bicyclo-(2,2,2)-octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydro-naphthalene-2,6-diyl, 1,2,3,4-tetrahydro-naphthalene-2,6-diyl, cyclobutane-1,3-diyl, spiro[3.3]heptane-2,6-diyl or dispiro[3.1.3.1] decane-2,8-diyl, wherein the preceding groups are each unsubstituted, or mono-, di-, tri- or tetrasubstituted with F, Cl, CN or alkyl, alkoxy, alkylcarbonyl or alkoxycarbonyl groups with 1 to 7 C atoms, wherein one or more H atoms may be substituted by F or Cl, and
m is 0, 1, 2or 3.

3. The mesogenic medium according to claim 1 , comprising one or more compounds selected from formulae A-I to A-III, wherein MG 11 and MG 12 , MG 21 and MG 22 and MG 31 and MG 32 are each independently one of the following formulae or their mirror images

wherein
L is in each occurrence independently of each other F, Cl, CN, OH, NO 2 or an optionally fluorinated alkyl, alkoxy or alkanoyl group with 1 to 7 C atoms, and
r is in each occurrence independently of each other 0, 1, 2, 3 or 4.

4. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula A-I.

5. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula A-II, which are of formulae A-II-1 to A-II-4

wherein n is 1 to 15.

6. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula A-Ill, which are of formulae A-III-1 to A-III-11

wherein n is 1 to 15.

7. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula B-I.

8. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula B-II.

9. The mesogenic medium according to claim 1 , which comprises one or more compounds of formula B-III.

10. The mesogenic medium according to claim 1 , which comprises component B, consisting of compounds selected from the group consisting of compound of formulae B-I, B-II and B-III, which are present in a concentration 40% or less by weight based on the medium as a whole.

11. The mesogenic medium according to claim 1 , which exhibits first and second nematic phases.

12. A liquid crystal device comprising a mesogenic medium according to claim 1 .

Assignees

• Merck Patent Gmbh

Inventors

• Tuffin Rachel
• Snow Benjamin
• Parri Owain Llyr
• Siemianowski Simon
• Proctor Rebecca
• Adlem Kevin

Classifications

• C09K2019/183

  Ph-Ph-C≡C-Ph · CPC title

• G02F1/134309

  characterised by their geometrical arrangement · CPC title

• C09K2019/3016

  Cy-Ph-Ph · 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

• C09K19/12

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