Iodine-based polarizer, polarizing plate, optical film, and image display device

Patent metadata

Field	Value
Publication number	US-10620353-B2
Application number	US-201815986240-A
Country	US
Kind code	B2
Filing date	May 22, 2018
Priority date	Jan 5, 2012
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

An iodine-based polarizer includes a polyvinyl alcohol-based film; and iodine adsorbed and oriented in the polyvinyl alcohol-based film, the iodine-based polarizer having be undergone a treatment with a treatment bath containing at least one reducing agent, the iodine-based polarizer containing an oxidized form of the reducing agent, wherein the total content of the reducing agent and the oxidized form is from 0.06×10−6 mol/g to 1.6×10−6 mol/g. The iodine-based polarizer has a sufficiently high level of transmittance, degree of polarization, and other optical properties and can suppress light leakage in short-wavelength.

First claim

What is claimed is:

1. An iodine-based polarizer, comprising:
a polyvinyl alcohol-based film; and
iodine adsorbed and oriented in the polyvinyl alcohol-based film,
the iodine-based polarizer containing a reducing agent and an oxidized form of the reducing agent,
wherein the total content of the reducing agent and the oxidized form is from 0.06×10 −6 mol/g to 1.6×10 −6 mol/g, and
wherein the reducing agent comprises at least one of ascorbic acid, erythorbic acid, thiosulfuric acid, sulfurous acid, chlorogenic acid, citric acid, rosmarinic acid, and salts thereof.

2. The iodine-based polarizer according to claim 1 , the iodine-based polarizer having be undergone a treatment with a treatment bath containing at least one reducing agent,
wherein a concentration of the reducing agent in the treatment bath is 0.001 to 0.015% by weight.

3. The iodine-based polarizer according to claim 2 , the concentration of the reducing agent in the treatment bath is 0.008 to 0.015% by weight.

4. The iodine-based polarizer according to claim 1 , the total content of the reducing agent and the oxidized form is from 0.11×10 −6 mol/g to 1.4×10 −6 mol/g.

5. The iodine-based polarizer according to claim 1 , the total content of the reducing agent and the oxidized form is from 0.16×10 −6 mol/g to 1.2×10 −6 mol/g.

6. A polarizing plate, comprising:
the iodine-based polarizer according to claim 1 ; and
a transparent protective film provided on at least one side of the iodine-based polarizer.

7. An optical film, comprising the polarizing plate according to claim 6 .

8. An image display device, comprising the polarizing plate according to claim 6 .

9. An optical film, comprising the iodine-based polarizer according to claim 1 .

10. An image display device, comprising the iodine-based polarizer according to claim 1 .

11. An image display device, comprising the optical film according to claim 9 .

Assignees

• Nitto Denko Corp

Inventors

• Yasen Muniridin
• Ogomi Daisuke
• Saiki Yuuji

Classifications

• G02B5/3033

  in the form of a thin sheet or foil, e.g. Polaroid · CPC title

• G02B1/08

  made of polarising materials · CPC title

• G02B5/305 Primary

  including organic materials, e.g. polymeric layers · CPC title