Polarizer, polarizing plate, and image display apparatus

Patent metadata

Field	Value
Publication number	US-11061176-B2
Application number	US-202016801670-A
Country	US
Kind code	B2
Filing date	Feb 26, 2020
Priority date	Apr 25, 2014
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A polarizer that can realize the multi-functionalization and high-functionalization of an electronic device, such as an image display apparatus. A polarizer including a resin film containing a dichroic substance, wherein the polarizer has a low dichroic substance concentration portion whose content of the dichroic substance is relatively low in the resin film. In the polarizer, the low dichroic substance concentration portion has a content of an alkali metal and/or an alkaline earth metal of 3.6 wt % or less.

First claim

The invention claimed is:

1. A method of producing a polarizer, comprising:
bringing a basic solution into contact with a resin film containing a dichroic substance; and
reducing, in a contact portion, a content of an alkali metal and/or an alkaline earth metal in the resin film,
wherein the reducing a content of an alkali metal salt and/or an alkaline earth metal salt is performed by bringing a treatment liquid into contact with the contact portion,
the treatment liquid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, water having a temperature of 50° C. or more, and a combination of water having a temperature of 40° C. or more with hydrochloric acid, sulfuric acid or nitric acid.

2. The production method according to claim 1 , wherein the reducing a content of an alkali metal and/or an alkaline earth metal in the contact portion is performed so that the content may be 3.6 wt % or less.

3. The production method according to claim 1 , wherein the treatment liquid contains water.

4. The production method according to claim 1 , wherein the treatment liquid contain water and has a temperature of 55° C. or more and 95° C. or less.

5. The production method according to claim 1 , wherein the treatment liquid is hydrochloric acid, sulfuric acid or nitric acid.

6. The production method according to claim 5 , wherein the resin film contains boric acid.

7. The production method according to claim 1 , wherein the reducing the content of the alkali metal salt and/or the alkaline earth metal salt is performed by bringing a first treatment liquid into contact with the contact portion, and a second treatment liquid into contact with the contact portion, wherein the first treatment liquid is different to the second treatment liquid.

8. The production method according to claim 7 , wherein the first treatment liquid into contact with the contact portion and the second treatment liquid into contact with the contact portion are independently selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, water having a temperature of 50° C. or more, and a combination of water having a temperature of 40° C. or more with hydrochloric acid, sulfuric acid or nitric acid.

Assignees

• Nitto Denko Corp

Inventors

• Ogomi Daisuke
• Saiki Yuji
• Yaegashi Masahiro
• Nakai Kota
• Nakano Yuki

Classifications

• G02B5/3025 Primary

  Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence) · CPC title

• H10K59/8791

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title

• G02B5/3033 Primary

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

• G02F1/133528

  Polarisers · CPC title

• H01L51/5281

  Electricity · mapped topic