Liquid-crystal medium

Patent metadata

Field	Value
Publication number	US-12187944-B2
Application number	US-202318200834-A
Country	US
Kind code	B2
Filing date	May 23, 2023
Priority date	May 31, 2022
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

A liquid-crystal (LC) medium which is based on a mixture of polar compounds and is substantially dielectrically neutral, its use for optical, electro-optical and electronic purposes, in particular as optical retarder or optical compensator in LC displays, an optical retarder or optical compensator containing the LC medium, an optical, electrooptical or electronic device containing the optical retarder or optical compensator, and a process of manufacturing the optical retarder or optical compensator.

First claim

The invention claimed is:

1. An LC medium which comprises a first component A which has a dielectric anisotropy Δε of ≥+0.5, and a second component B which has a dielectric anisotropy Δε of ≤−0.5, wherein the proportions of the components A and B are selected such that the resulting dielectric anisotropy Δε of the LC medium is −0.3 to +0.3, and wherein the LC medium shows uniform alignment, wherein the dielectric anisotropies are all determined at 20° C. and 1 KHz.

2. An LC medium which comprises a first component A which has a dielectric anisotropy Δε of ≥+0.5, a second component B which has a dielectric anisotropy Δε of ≤−0.5, and a third component C which has a dielectric anisotropy Δε from −0.5 to +0.5, wherein the proportions of the components A, B and C are selected such that the resulting dielectric anisotropy Δε of the LC medium is −0.3 to +0.3, wherein the dielectric anisotropies are all determined at 20° C. and 1 KHz.

3. The LC medium according to claim 1 , wherein the first component A comprises one or more compounds selected from the group consisting of compounds of formulae IA, IB, IC, ID and IE and wherein the second component B comprises one or more compounds selected from the group consisting of compounds of formulae IIA, IIB, IIC and IID

in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning:
R 0 , R 21 , R 22 are H, or an alkyl or alkoxy radical having 1 to 15 C atoms or an alkenyl radical having 2 to 15 C atoms, which are un-substituted or monosubstituted by F, Cl, CN or CF 3 and in which one or more CH 2 groups may be replaced by —O—, —S—, —C≡C—, —CF 2 O—, —OCF 2 -, —OC—O—, —O—CO—

 in such a way that O- and/or S-atoms are not linked directly to one another,
Z 0 , Z 1 , Z 2 are —CO—O—, —O—CO—, —CF 2 O, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 —, —CH 2 CH 2 —, —(CH 2 ) 4 —, —CH═CH—CH 2 O—, —C 2 F 4 —, —CH 2 CF 2 —, —CF 2 CH 2 —, —CF═CF—, —CH═CF—, —CF═CH—, —CH═CH—, —C≡C— or a single bond,
X 0 is F, Cl, CN, SF 5 , SCN, NCS, or a halogenated alkyl radical or a halogenated alkoxy radical having 1 to 6 C atoms, or a halogenated alkenyl radical or a halogenated alkenyloxy radical having 2 to 6 C atoms,
Y 1-4 are H or F,
L 1 to L 4 are F, Cl, CF 3 or CHF 2 ,
Y, Y 0 are H, F, Cl, CF 3 , CHF 2 , CH 3 or OCH 3 ,
p is 0, 1 or 2,
q is 0 or 1,
r is 0 or 1, and
S is 0 or 1.

4. The LC medium according to claim 2 , wherein the third component C comprises one or more compounds selected from the group consisting of compounds of formulae IV, IVa, IVb and V

in which the individual radicals, on each occurrence identically or differently, and each, independently of one another, have the following meaning
R 41 is an unsubstituted alkyl radical having 1 to 7 C atoms, in which one or more CH 2 groups may be replaced by

 or an unsubstituted alkenyl radical having 2 to 7 C atoms,
R 42 is an unsubstituted alkyl radical having 1 to 7 C atoms or an unsubstituted alkoxy radical having 1 to 6 C atoms, or an unsubstituted alkenyl radical having 2 to 7 C atoms,

 denotes

Z 4 is a single bond, —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —COO—, —OCO—, —C 2 F 4 —, —C 4 H 8 — or —CF═CF—,
R 51 , R 52 are H, an alkyl or alkoxy radical having 1 to 15 C atoms or an alkenyl radical having 2 to 15 C atoms, which are unsubstituted, monosubstituted by F, Cl, CN or CF 3 or at least monosubstituted by halogen, in which one or more CH 2 groups may be replaced by —O—, —S—, —C≡C—, —CF 2 O—, —OCF 2 —, —OC—O—, —O—CO—

 in such a way that O atoms are not linked directly to one another,

 identically or differently, denote

Z 51 , Z 52 are —CH 2 —CH 2 —, —CH 2 —O—, —CH≡CH—, —C≡C—, —COO— or a single bond, and
n 1 or 2.

5. The LC medium according to claim 1 , wherein the first component A comprises one or more compounds selected from compounds of the following formulae:

in which
R 0 is H, or an alkyl or alkoxy radical having 1 to 15 C atoms or an alkenyl radical having 2 to 15 C atoms, which are unsubstituted or monosubstituted by F, Cl, CN or CF 3 and in which one or more CH 2 groups may be replaced by —O—, —S—, —C≡C—, —CF 2 O—, —OCF 2 —, —OC—O—, —O—CO—

 in such a way that O- and/or S-atoms are not linked directly to one another, and
X 0 is F, Cl, CN, SF 5 , SCN, NCS, or a halogenated alkyl radical or a halogenated alkoxy radical having 1 to 6 C atoms, or a halogenated alkenyl radical or a halogenated alkenyloxy radical having 2 to 6 C atoms.

6. The LC medium according to claim 1 , wherein the first component A comprises one or more compounds selected from compounds of the following formulae:

in which
R 0 , R 1 are H, or an alkyl or alkoxy radical having 1 to 15 C atoms or an alkenyl radical having 2 to 15 C atoms, which are unsubstituted or monosubstituted by F, Cl, CN or CF 3 and in which one or more CH 2 groups may be replaced by —O—, —S—, —C≡C—, —CF 2 O—, —OCF 2 —, —OC—O—, —O—CO—

 in such a way that O- and/or S-atoms are not linked directly to one another.

7. The LC medium according to claim 1 , wherein the second component B comprises one or more compounds selected from compounds of the following formulae:

Assignees

• Merck Patent Gmbh

Inventors

• Laut Sven Christian
• Tseng Tzu-Huan
• Chou Kuang-Ting
• Huang Chi-Shun

Classifications

• C09K19/54

  Additives having no specific mesophase {characterised by their chemical composition} · CPC title

• C09K2019/3016

  Cy-Ph-Ph · CPC title

• C09K2019/122

  Ph-Ph · CPC title

• C09K2019/3054

  Cy-Cy-CH=CH-Ph · CPC title

• C09K2019/3053

  Cy-CH=CH-Ph · CPC title