Polarizing film, method of manufacturing polarizing film, and image display apparatus using the polarizing film

Patent metadata

Field	Value
Publication number	US-9690011-B2
Application number	US-201414464199-A
Country	US
Kind code	B2
Filing date	Aug 20, 2014
Priority date	Sep 6, 2013
Publication date	Jun 27, 2017
Grant date	Jun 27, 2017

Abstract

There is provided a polarizing film that is excellent in external appearance and can contribute to the improvement of the display characteristics of an image display apparatus. A polarizing film according to an embodiment of the present invention includes a polyvinyl alcohol-based resin film containing iodine. The polarizing film has a ratio I 2 /I 1 between an iodine concentration I 1 on one surface and an iodine concentration I 2 on another surface of 3.0 or more.

First claim

What is claimed is:

1. A polarizing film, comprising a polyvinyl alcohol-based resin film containing iodine,
wherein the polarizing film has a ratio I 2 /I 1 between an iodine concentration I 1 on one surface and an iodine concentration I 2 on another surface of 3.0 or more, and
wherein the surface having the iodine concentration I 1 has an anisotropic reflection (Rc/Rp) at a wavelength of 680 nm of 1.50 or less.

2. A polarizing film according to claim 1 , wherein the polarizing film is used so that the surface having the iodine concentration I 1 is on a viewer side.

3. A manufacturing method for the polarizing film according to claim 1 , the manufacturing method comprising:
forming a polyvinyl alcohol-based resin layer on one side of a resin substrate; and
stretching and dyeing a laminate of the resin substrate and the polyvinyl alcohol-based resin layer to turn the polyvinyl alcohol-based resin layer into a polarizing film,
the polarizing film having a ratio I 2 /I 1 between an iodine concentration I 1 on a surface on a resin substrate side and an iodine concentration I 2 on a surface on an opposite side to the resin substrate of 3.0 or more.

4. A manufacturing method according to claim 3 , wherein the stretching is performed using in-air stretching alone.

5. A manufacturing method according to claim 4 , wherein a stretching temperature in the in-air stretching is 120° C. or more.

6. An image display apparatus, comprising the polarizing film according to claim 1 ,
wherein the polarizing film is arranged so that the surface having the iodine concentration is on a viewer side.

7. An image display apparatus according to claim 6 , wherein the I 2 /I 1 ratio is 2.5 or more.

8. An image display apparatus according to claim 6 , wherein the I 2 /I 1 ratio is 4.0 or more.

9. An image display apparatus according to claim 6 , wherein the anisotropic reflection (Rc/Rp) is 1.30 or less.

10. An image display apparatus according to claim 6 , wherein the anisotropic reflection (Rc/Rp) is 1.20 or less.

11. A polarizing film according to claim 1 , wherein the I 2 /I 1 ratio is 3.5 or more.

12. A polarizing film according to claim 1 , wherein the I 2 /I 1 ratio is 4.0 or more.

13. A polarizing film according to claim 1 , wherein the anisotropic reflection (Rc/Rp) is 1.30 or less.

14. A polarizing film according to claim 1 , wherein the anisotropic reflection (Rc/Rp) is 1.20 or less.

Assignees

• Nitto Denko Corp

Inventors

• Goto Shusaku
• Kamijo Takashi
• Miyatake Minoru

Classifications

• G02B1/08 Primary

  made of polarising materials · CPC title

• B29K2105/256

  Sheets, plates, blanks or films · CPC title

• B29K2031/04

  Polymers of vinyl acetate, e.g. PVAc, i.e. polyvinyl acetate · CPC title

• B29D11/00894

  colouring or tinting · CPC title

• B29D11/00644

  polarizing · CPC title