Optical laminate and manufacturing method therefor, smart window comprising same, and vehicle and building windows and doors to which same are applied

Patent metadata

Field	Value
Publication number	US-12313942-B2
Application number	US-202218577923-A
Country	US
Kind code	B2
Filing date	Jul 4, 2022
Priority date	Jul 13, 2021
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

The present invention relates to a variable transmittance optical laminate and a manufacturing method therefor, a smart window comprising same, and vehicle and building windows and doors to which same is applied, the variable transmittance optical laminate comprising: a first polarizing plate; a first transparent conductive layer formed on the inner surface of the first polarizing plate; a second polarizing plate facing the first polarizing plate; a second transparent conductive layer which is formed on the inner surface of the second polarizing plate and which faces the first transparent conductive layer; a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and an alignment film formed on the inner surface of the transparent conductive layer.

First claim

The invention claimed is:

1. A variable transmittance optical stack comprising:
a first polarizing plate;
a first transparent conductive layer formed on an inner surface of the first polarizing plate;
a second polarizing plate opposing the first polarizing plate;
a second transparent conductive layer formed on an inner surface of the second polarizing plate, and opposing the first transparent conductive layer;
a liquid crystal layer provided between the first transparent conductive layer and the second transparent conductive layer; and
an alignment film formed on an inner surface of each of the first transparent conductive layer and the second transparent conductive layer,
wherein 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 without an additional substrate: between the first polarizing plate and the first transparent conductive layer; or between the second polarizing plate and the second transparent conductive layer,
wherein at least one polarizing plate of the first polarizing plate and the second polarizing plate comprises a polarizer and a coating layer provided between the polarizer and at least one of the first transparent conductive layer and the second transparent conductive layer, and
wherein the coating layer comprises nanoparticles.

2. The variable transmittance optical stack of claim 1 , wherein the nanoparticles comprise silica particles.

3. The variable transmittance optical stack of claim 1 , wherein the nanoparticles have particle diameters less than or equal to 50 nm.

4. The variable transmittance optical stack of claim 1 , wherein the coating layer has a thickness ranging from 3 to 10 μm.

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

6. The variable transmittance optical stack of claim 1 , wherein at least one 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 materials, conductive polymers, conductive ink, and nanowires.

7. The variable transmittance optical stack of claim 1 , wherein at least one of the first transparent conductive layer and the second transparent conductive layer has a transmittance of equal to or greater than 50% for visible light.

8. The variable transmittance optical stack of claim 1 , wherein at least one of the first polarizing plate and the second polarizing plate comprises at least one of a protective film and an optical functional film.

9. The variable transmittance optical stack of claim 8 , wherein the protective film comprises one or more types selected from the group consisting of polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, diacetyl cellulose, triacetyl cellulose, polycarbonate, polymethyl acrylate, polymethyl methacrylate, polyethyl acrylate, polyethyl methacrylate, and cyclic olefin polymer.

10. The variable transmittance optical stack of claim 1 , wherein at least one polarizing plate of the first polarizing plate and the second polarizing plate has a thickness ranging from 30 μm to 200 μm.

11. The variable transmittance optical stack of claim 1 , wherein the liquid crystal layer comprises one or more types selected from the group consisting of a ball spacer and a column spacer.

12. The variable transmittance optical stack of claim 11 , wherein the ball spacer has a diameter ranging from 1 μm to 10 μm.

13. The variable transmittance optical stack of claim 11 , wherein an occupancy area of the ball spacer in the liquid crystal layer ranges from 0.01% to 10% of the area of the liquid crystal layer.

14. The variable transmittance optical stack of claim 1 , further comprising:
a refractive index-matching layer having a refractive index ranging from 1.4 to 2.6.

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

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

17. A vehicle in which the smart window of claim 16 is applied to at least one of a front window, a rear window, a side window, a sunroof window, and an inner partition thereof.

18. Building windows and doors comprising the smart window of claim 16 .

Assignees

• Dongwoo Fine Chem Co Ltd

Inventors

• Kim Dong-Hwi
• Lim Geo-San

Classifications

• G02F1/1337

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

• G02F1/133528

  Polarisers · CPC title

• E06B2009/2464

  featuring transparency control by applying voltage, e.g. LCD, electrochromic panels · 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

• B60J3/04

  adjustable in transparency · CPC title