Liquid crystal cell

Patent metadata

Field	Value
Publication number	US-2016115389-A1
Application number	US-201414889760-A
Country	US
Kind code	A1
Filing date	Jul 11, 2014
Priority date	Jul 12, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

Provided are a liquid crystal cell and a use thereof. An exemplary liquid crystal cell can be implemented in a bistable mode switching between a haze mode and a non-haze mode even with low driving voltage. Such a liquid crystal cell can be applied to various optical modulation apparatus, such as a smart window, a window protection film, a flexible display element, an active retarder for a 3D visual display, and a viewing angle-controlling film.

First claim

1 . A bistable liquid crystal cell comprising two opposite substrates; and a liquid crystal layer provided between the two substrates and including a smectic liquid crystal compound, and an ionic compound having an anion represented by the following Chemical Formula 1:
I n −   [Chemical Formula 1]
where, in Chemical Formula 1, n represents a number of 2 or more.

2 . The bistable liquid crystal cell of claim 1 , wherein the liquid crystal compound is a smectic A liquid crystal compound.

3 . The bistable liquid crystal cell of claim 1 , wherein the smectic liquid crystal compound is a compound represented by the following Chemical Formula 2:

where, in Chemical Formula 2, A represents a single bond, —COO—, or —OCO—, and R 1 to R 10 each independently represent a hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, a nitro group, or a substituent represented by the following Chemical Formula 3, wherein, in Chemical Formulas 2 and 3, any one of R 1 to R 15 is an alkyl group, an alkoxy group, or an alkoxycarbonyl group having 5 or more carbon atoms,

where, in Chemical Formula 3, B represents a single bond, —COO—, or —OCO—, and R 11 to R 15 each independently represent a hydrogen, a halogen, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group, or a nitro group.

4 . The bistable liquid crystal cell of claim 1 , wherein, in Chemical Formula 1, n represents a number within the range of 3 to 10.

5 . The bistable liquid crystal cell of claim 1 , wherein the ionic compounds are a nitrogen-containing onium salt, a sulfur-containing onium salt, or a phosphorus-containing onium salt.

6 . The bistable liquid crystal cell of claim 1 , wherein the ionic compound includes a cation represented by any one of the following Chemical Formulas 4 to 7:

where, in Chemical Formula 4, R a represents a hydrocarbon group having 4 to 20 carbon atoms, and includes a heteroatom, and R b and R c each represent hydrogen, or a hydrocarbon group having 1 to 16 carbon atoms, and include a heteroatom, wherein R c is not included when the nitrogen atom has a double bond,

where, in Chemical Formula 5, R d represents a hydrocarbon group having 2 to 20 carbon atoms, and includes a heteroatom, and R e , R f , and R g each represent hydrogen, and a hydrocarbon group having 1 to 16 carbon atoms, and include a heteroatom,

where, in Chemical Formula 6, R h represents a hydrocarbon group having 2 to 20 carbon atoms, and includes a heteroatom, and R i , R j , and R k each represent hydrogen, and a hydrocarbon group having 1 to 16 carbon atoms, and include a heteroatom,

where, in Chemical Formula 7, Z represents a nitrogen, sulfur, or phosphorus atom, R 1 , R m , R n , and R o each represent a hydrocarbon group having 1 to 20 carbon atoms and include a heteroatom, wherein R o is not included when Z is a sulfur atom.

7 . The bistable liquid crystal cell of claim 1 , wherein a ratio of the ionic compounds in the liquid crystal layer is within the range of 0.005 wt % to 5.0 wt %.

8 . The bistable liquid crystal cell of claim 1 , wherein the bistable liquid crystal cell is formed so that the bistable liquid crystal cell switches between a haze mode having a haze of 80% or more and a non-haze mode having a haze of 10% or less.

9 . The bistable liquid crystal cell of claim 8 , wherein voltage required for switching between the haze mode and the non-haze mode is 120 V or less.

10 . The bistable liquid crystal cell of claim 1 , wherein the bistable liquid crystal cell is formed so that the bistable liquid crystal cell switches between a transmission mode having a transmittance of 85% or more and a white mode having a transmittance of 83% or less.

11 . The bistable liquid crystal cell of claim 1 , wherein the liquid crystal layer further includes an anisotropic dye.

12 . The bistable liquid crystal cell of claim 11 , wherein the anisotropic dye is included in the liquid crystal layer in the ratio within the range of 0.01 wt % to 2 wt %.

13 . The bistable liquid crystal cell of claim 11 , wherein the bistable liquid crystal cell is formed so that the bistable liquid crystal cell switches between a transmission mode having a transmittance of 50% or more and a black mode having a transmittance of 40% or less.

14 . The bistable liquid crystal cell of claim 1 , wherein the liquid crystal layer further includes a polymer network.

15 . The bistable liquid crystal cell of claim 14 , wherein the polymer network is included in the liquid crystal layer in a ratio of 40 wt % or less.

16 . The bistable liquid crystal cell of claim 1 , further comprising an alignment layer provided on the side of the liquid crystal layer of the substrates.

17 . The bistable liquid crystal cell of claim 1 , further comprising an electrode layer provided on the side of the liquid crystal layer of the substrate.

18 . An optical modulation apparatus comprising the liquid crystal cell of claim 1 .

19 . A smart window comprising the liquid crystal cell of claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Lim Eun Jung
• Kim Jung Woon
• Oh Dong Hyun

Classifications

• C09K2019/122

  Ph-Ph · CPC title

• C09K2019/2035

  Ph-COO-Ph · CPC title

• C09K19/2007

  the chain containing -COO- or -OCO- groups · CPC title

• C09K19/54 Primary

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

• G02F1/1391

  Bistable or multi-stable liquid crystal cells (G02F1/141 takes precedence) · CPC title