Polarizer, polarizing plate, and method of producing polarizer

Patent metadata

Field	Value
Publication number	US-10215901-B2
Application number	US-201615338975-A
Country	US
Kind code	B2
Filing date	Oct 31, 2016
Priority date	Nov 4, 2015
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

There is provided a polarizer excellent in heat resistance. A polarizer according to an embodiment of the present invention includes a resin film containing iodine, wherein an end portion of the resin film has formed therein a high-concentration portion having a concentration of a substance that forms a counter ion of iodine higher than that of another portion.

First claim

The invention claimed is:

1. A polarizer, comprising a resin film containing iodine, wherein at least one end portion of the resin film has formed therein a high-concentration portion having a concentration of a substance that forms a counter ion of iodine higher than that of another portion, wherein the at least one end portion comprises an outer peripheral edge of the polarizer including a site forming a substantially V-shape that is convexly curved in a plane direction and/or an internal peripheral edge of a through hole, and wherein the polarizer has a polarization degree of 99.8% or more.

2. The polarizer according to claim 1 , wherein the concentration of the substance that forms a counter ion of iodide in the other portion is from 0.3 wt % to 5 wt %.

3. The polarizer according to claim 1 , wherein the high-concentration portion has a concentration gradient that the concentration of the substance that forms the counter ion of iodine increases toward the outer edge and/or toward the internal edge in a plane direction.

4. The polarizer according to claim 1 , wherein the high-concentration portion is formed from the outer edge and/or internal edge to a position distant therefrom by 100 μm or more in a plane direction.

5. The polarizer according to claim 1 , wherein the substance that forms a counter ion of iodine contains at least one of potassium or sodium.

6. The polarizer according to claim 1 , wherein the resin film contains boric acid, and the at least one end portion of the resin film has formed therein a low-concentration portion having a concentration of the boric acid lower than that of another portion.

7. The polarizer according to claim 6 , wherein a region of the high-concentration portion includes a region of the low-concentration portion of the boric acid.

8. The polarizer according to claim 7 , wherein the high-concentration portion is formed in a region including an entirety of the region of the low-concentration portion of the boric acid.

9. The polarizer according to claim 6 , wherein the low-concentration portion has a concentration gradient that a boric acid concentration reduces toward the outer edge and/or toward the internal edge in a plane direction.

10. The polarizer according to claim 6 , wherein the low-concentration portion is formed from the outer edge and/or internal edge to a position distant therefrom by 50 μm or more in a plane direction.

11. The polarizer according to claim 6 , wherein the low-concentration portion is formed in the at least one end portion in an absorption axis direction.

12. The polarizer according to claim 6 , wherein the polarizer has formed therein the through-hole and the low-concentration portion is formed in the internal peripheral edge of the through-hole.

13. The polarizer according to claim 6 , wherein the low-concentration portion is formed in the outer peripheral edge including the site that forms a substantially V-shape that is convexly curved in a plane direction.

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

15. A method of producing a polarizer, comprising bringing a treatment liquid containing a substance that forms a counter ion of iodine into contact with a resin film containing iodine to form, in at least one end portion of the resin film, a high-concentration portion having a concentration of the substrate that forms a counter ion of iodine higher than that of another portion; and
forming the at least one end portion of the resin film, wherein the at least one end portion comprises an outer peripheral edge of the polarizer including a site forming a substantially V-shape that is convexly curved in a plane direction and/or an internal peripheral edge of a through hole, and wherein the polarizer has a polarization degree of 99.8% or more.

16. The production method according to claim 15 , wherein the treatment liquid comprises a solution obtained by dissolving, in a solvent, a compound containing the substance that forms a counter ion of iodine.

17. The production method according to claim 16 , wherein the compound contains at least one of potassium iodide or sodium chloride.

18. The production method according to claim 15 , wherein the treatment liquid has a liquid temperature of 50° C. or more.

19. The production method according to claim 15 , wherein forming the at least one end portion of the resin film comprises at least one of cutting or punching processing.

20. The production method according to claim 19 , wherein the at least one of the cutting or the punching processing is performed by irradiating the resin film with laser light.

21. The production method according to claim 20 , wherein the laser light comprises CO 2 laser light.

Assignees

• Nitto Denko Corp

Inventors

• Takada Katsunori
• Ogomi Daisuke
• Nagano Shinobu
• Suefusa Eiko
• Kitamura Yoshitsugu
• Kuramoto Hiroki
• Sugino Youichirou
• Kimura Keisuke

Classifications

• B32B27/306

  comprising vinyl acetate or vinyl alcohol (co)polymers · CPC title

• B29K2105/256

  Sheets, plates, blanks or films · CPC title

• B29D11/00432

  Auxiliary operations, e.g. machines for filling the moulds (B29D11/00125 takes precedence) · CPC title

• B32B5/142

  Variation across the area of the layer · CPC title

• G02B1/08

  made of polarising materials · CPC title