Optical stack, and manufacturing method for same, and smart window including same, and automobile or windows for building using same

Patent metadata

Field	Value
Publication number	US-12282220-B2
Application number	US-202418416438-A
Country	US
Kind code	B2
Filing date	Jan 18, 2024
Priority date	Feb 28, 2023
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

Abstract

A variable transmittance optical stack, a manufacturing method therefor, a smart window including the same, and windows for an automobile or a building using the same are proposed.

First claim

What is claimed is:

1. A variable transmittance optical stack comprising:
a first polarizing plate;
a first transparent conductive layer disposed on one surface of the first polarizing plate;
a first alignment film disposed on the first transparent conductive layer;
a second polarizing plate disposed opposite to the first polarizing plate;
a second transparent conductive layer disposed on one surface of the second polarizing plate, and opposite to the first transparent conductive layer;
a second alignment film disposed on the second transparent conductive layer; and
a liquid crystal layer disposed between the first alignment film and the second alignment film,
wherein the liquid crystal layer comprises a polymer network and a liquid crystal compound, wherein the liquid crystal layer does not comprise any of a sealant or a spacer,
wherein the liquid crystal compound is arranged with uniform initial alignment,
wherein at least one transparent conductive layer of the first transparent conductive layer and the second transparent conductive layer is disposed directly contacting the first polarizing plate or the second polarizing plate without an additional substrate between the at least one transparent conductive layer and the first polarizing plate or the second polarizing plate, and
wherein the liquid crystal layer comprises a cured product of a composition for forming the liquid crystal layer, which comprises a polymerizable monomer and a liquid crystal compound,
wherein the liquid crystal compound comprises a chiral nematic liquid crystal compound, and
wherein a pitch of the chiral nematic liquid crystal compound is ranged from 5 to 20 μm.

2. The variable transmittance optical stack of claim 1 , wherein a liquid crystal operating method of the liquid crystal layer is selected from the group consisting of a twisted nematic mode, a super twisted nematic mode, an in-plane switching mode, a fringe-field mode, and a vertical alignment mode.

3. The variable transmittance optical stack of claim 2 , wherein the liquid crystal operating method of the liquid crystal layer is the twisted nematic mode.

4. The variable transmittance optical stack of claim 1 , wherein the composition for forming the liquid crystal layer comprises 10 to 30% by weight of the polymerizable monomer with respect to the total weight of the composition.

5. The variable transmittance optical stack of claim 1 , wherein the first alignment film and the second alignment film are aligned by a rubbing manner.

6. The variable transmittance optical stack of claim 1 , wherein each of the first transparent conductive layer and the second transparent conductive layer comprises one or more types selected from the group consisting of transparent conductive oxide, metal, carbonaceous material, conductive polymers, conductive ink, and nanowires.

7. The variable transmittance optical stack of claim 1 , wherein the at least one transparent conductive layer of the first transparent conductive layer and the second transparent conductive layer is formed by directly contacting with the first polarizing plate or the second polarizing plate with a highly adhesive layer between the first polarizing plate or the second polarizing plate and the at least one transparent conductive layer.

8. The variable transmittance optical stack of claim 1 , wherein at least one polarizing plate of the first polarizing plate and the second polarizing plate comprises one or more types of functional layers selected from the group consisting of a protective layer, a retardation matching layer, and a refractive index-matching layer.

9. The variable transmittance optical stack of claim 1 , wherein each of the first polarizing plate and the second polarizing plate has a thickness ranged from 30 μm to 200 μm.

10. The variable transmittance optical stack of claim 1 , further comprising:
one or more types selected from the group consisting of a pressure sensitive adhesive/adhesive layer, an ultraviolet ray absorption layer, and a hard coating layer.

11. A manufacturing method for the variable transmittance optical stack of claim 1 .

12. A smart window comprising the variable transmittance optical stack of claim 1 .

Assignees

• Dongwoo Fine Chem Co Ltd

Inventors

• Kim Hyun-Seong
• Kim Jin-Ho
• Ryu Hyun-Sun
• Choi Ju-Seob

Classifications

• G02F1/1396

  the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell (G02F1/141 takes precedence) · CPC title

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title

• G02F1/133784

  by rubbing · CPC title

• E06B2009/2417

  Light path control; means to control reflection · CPC title

• E06B9/24

  Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; {Slat blinds}(operating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00) · CPC title