Polarizer, polarizing plate, and method for producing polarizer

Patent metadata

Field	Value
Publication number	US-10107947-B2
Application number	US-201615545766-A
Country	US
Kind code	B2
Filing date	Mar 10, 2016
Priority date	Apr 17, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

There is provided a polarizer excellent in durability. A polarizer according to one embodiment of the present invention includes a resin film containing boric acid, wherein the resin film has a low-concentration portion, which contains a lower concentration of the boric acid than that in any other site, formed in an end portion thereof.

First claim

The invention claimed is:

1. A polarizer, comprising a resin film containing boric acid, wherein the resin film has a low-concentration portion, Which contains a lower concentration of the boric acid than that in any other site, formed in an end portion thereof.

2. The polarizer according to claim 1 , wherein the low-concentration portion has such a concentration gradient that the concentration of the boric acid contained therein reduces outward in a plane direction.

3. The polarizer according to claim 1 , wherein the low-concentration portion is formed in a region ranging from an end surface of the resin film to a position distant therefrom by 50 μm or more inward in a plane direction.

4. The polarizer according to claim 1 , wherein the low-concentration portion is formed in the end portion in an absorption axis direction.

5. The polarizer according to claim 1 , wherein the polarizer has formed therein a through-hole and the low-concentration portion is formed in a peripheral edge portion of the through-hole.

6. The polarizer according to claim 1 , wherein the low-concentration portion is formed in an outer edge portion.

7. The polarizer according to claim 6 , wherein the outer edge portion includes a site that forms a substantially V-shape that is convex inward in a plane direction.

8. A polarizing plate, comprising:
the polarizer of claim 1 ; and
a protective film arranged on at least one surface of the polarizer.

9. A production method for a polarizer, comprising a step of bringing a treatment liquid into contact with, a resin film containing boric acid, to thereby form a low-concentration portion, which contains a lower concentration of the boric acid than that in any other site, in an end portion of the resin film.

10. The production method according to claim 9 , wherein the treatment liquid contains water.

11. The production method according to claim 9 , wherein the treatment liquid comprises a solution obtained by dissolving, in a solvent, a compound containing a substance capable of forming a counterion for iodine.

12. The production method according to claim 11 , wherein the compound contains potassium iodide and/or sodium chloride.

13. The production method according to claim 9 , wherein the treatment liquid has a liquid temperature of 50° C. or more.

14. The production method according to claim 9 , further comprising a step of forming the resin film containing boric acid into a desired shape through cutting or punching.

15. The production method according to claim 14 , wherein the cutting and/or the punching is performed by laser light irradiation.

16. The production method according to claim 15 , wherein the laser light comprises CO 2 laser light.

Assignees

• Nitto Denko Corp

Inventors

• Takada Katsunori
• Nakai Kota
• Higuchi Naotaka
• Kimura Keisuke
• Kitamura Yoshitsugu
• Kuramoto Hiroki

Classifications

• G02B5/3033

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

• C08J2329/04

  Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• G02B1/08

  made of polarising materials · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title