Method of producing polarizing plate

Patent metadata

Field	Value
Publication number	US-10466397-B2
Application number	US-201615332561-A
Country	US
Kind code	B2
Filing date	Oct 24, 2016
Priority date	Nov 4, 2015
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

There is provided a polarizing plate excellent in durability. A method of producing a polarizing plate according to an embodiment of the present invention includes: preparing a polarizing film laminate including a polarizer and a protective film arranged on at least one side of the polarizer; and shrinking the polarizing film laminate.

First claim

What is claimed is:

1. A method of producing a polarizing plate, comprising:
preparing a polarizing film laminate including a polarizer and a protective film arranged on at least one side of the polarizer;
shrinking the polarizing film laminate, and
cutting the shrunk polarizing film laminate,
wherein the cutting forms one selected from the group consisting of a through-hole, a site whose outer edge forms a V-shape that is convex inward in a plane direction, a site whose outer edge forms an R-shape that is convex inward in a plane direction, and the combination thereof, on the polarizing film laminate.

2. The production method according to claim 1 , wherein the shrinking the polarizing film laminate is performed in a transmission axis direction of the polarizer by 0.2% or more.

3. The production method according to claim 2 , further comprising cutting the shrunk polarizing film laminate.

4. The production method according to claim 2 , wherein the shrinking the polarizing film laminate is performed in a transmission axis direction of the polarizer by 0.2% to 0.6%.

5. A polarizing plate, which is obtained by the production method of claim 1 .

6. The production method according to claim 1 , wherein the cutting comprises one selected from the group consisting of a method involving irradiating the polarizing film laminate with laser light, a method involving using a cutting blade, and the combination thereof.

7. The production method according to claim 1 , further comprising forming a pressure-sensitive adhesive layer on the shrunk polarizing film laminate prior to the cutting.

8. The production method according to claim 1 , further comprising forming a pressure-sensitive adhesive layer on the shrunk polarizing film laminate after cutting the shrunk polarizing film laminate.

9. The production method according to claim 1 , wherein the preparing step further comprises a second protective film arranged on a side of the polarizer that is opposite to the protective film.

10. The production method according to claim 9 , wherein the second protective film is formed from a material selected from the group consisting of a (meth)acrylic resin, a cycloolefin-based resin, an olefin-based resin, an ester-based resin, a polyamide-based resin, a polycarbonate-based resin and a copolymer resin.

11. The production method according to claim 9 , wherein the second protective film has a thickness of 10 μm to 200 μm.

12. The production method according to claim 1 , wherein the protective film is formed from a material selected from the group consisting of a (meth)acrylic resin, a cycloolefin-based resin, an olefin-based resin, an ester-based resin, a polyamide-based resin, a polycarbonate-based resin and a copolymer resin.

13. The production method according to claim 1 , wherein the protective film has a thickness of 10 μm to 200 μm.

14. The production method according to claim 1 , wherein prior to the shrinkage step, a surface-treated layer is formed on a side of the protective film that is opposite to the side the polarizer is arranged on.

15. The production method according to claim 1 , wherein the shrinkage step is performed at a heating temperature of 70 to 90° C. and a heating time of 1 hour to 10 hours.

16. The production method according to claim 1 , wherein the shrinking the polarizing film laminate is performed in an absorption axis direction of the polarizer by 0.3% to 1.0%.

17. The production method according to claim 1 , wherein the shrinking the polarizing film laminate is performed in a transmission axis direction of the polarizer by 0.2% to 0.6% and
wherein the shrinking the polarizing film laminate is performed in an absorption axis direction of the polarizer by 0.3% to 1.0%.

18. A method of producing a polarizing plate, comprising:
preparing a polarizing film laminate including a polarizer and a protective film arranged on at least one side of the polarizer;
heating the polarizing film laminate for 10 hours to 100 hours at the temperature of 70° C. to 90° C., to thereby shrink the polarizing film laminate at a shrinkage ratio of 0.2% or more in a transmission axis direction of the polarizer; and
cutting the shrunk polarizing film laminate by laser irradiation to form one selected from the group consisting of a through-hole, a site whose outer edge forms a V-shape that is convex inward in a plane direction, a site whose outer edge forms an R-shape that is convex inward in a plane direction, and the combination thereof, on the polarizing film laminate.

Assignees

• Nitto Denko Corp

Inventors

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

Classifications

• B29C61/02

  Thermal shrinking · CPC title

• G02B5/3033 Primary

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

• B32B2307/42

  Polarizing, birefringent, filtering · CPC title

• G02B5/305 Primary

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

• B29C63/00

  Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor (B29C73/00 takes precedence; by blowing B29C49/00; by thermoforming B29C51/00) · CPC title