Thin film polarizer having superior optical properties, manufacturing method thereof, and polarizing plate and display device including the same

Patent metadata

Field	Value
Publication number	US-9684104-B2
Application number	US-201414386296-A
Country	US
Kind code	B2
Filing date	Jun 12, 2014
Priority date	Jun 18, 2013
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

There are provided a thin film polarizer having superior optical properties and a method of manufacturing the same. The thin film polarizer includes: forming a film laminate by attaching a non-stretched polyvinyl alcohol (PVA)-based film to at least one surface of a thermoplastic polyurethane film, using attractive force therebetween or using an adhesive; stretching the film laminate at a temperature of 45° C. to 55° C.; and separating the PVA-based film from the thermoplastic polyurethane film.

First claim

The invention claimed is:

1. A method of manufacturing a thin film polarizer, the method comprising:
forming a film laminate by attaching a prefabricated non-stretched polyvinyl alcohol (PVA)-based film to at least one surface of a thermoplastic polyurethane film, using attractive force therebetween or using an adhesive;
stretching the film laminate at a temperature of 45° C. to 55° C.; and
separating the PVA-based film from the thermoplastic polyurethane film.

2. The method of claim 1 , wherein the stretching of the film laminate is performed at a temperature of 50° C. to 55° C.

3. The method of claim 1 , wherein the stretching of the film laminate is performed at a magnification of 5 to 15 times.

4. The method of claim 1 , wherein the non-stretched PVA-based film has a thickness of 10 μm to 60 μm.

5. The method of claim 1 , wherein the stretching of the film laminate is performed in an aqueous boric acid solution having a boric acid concentration of 1% to 5%.

6. The method of claim 1 , wherein the stretching of the film laminate is performed in an aqueous boric acid solution having a boric acid concentration of 1% to 3%.

7. The method of claim 1 , wherein the stretching of the film laminate is performed to allow the PVA-based film to have a thickness of 10 μm or less.

8. The method of claim 1 , wherein the stretching of the film laminate is performed to allow for a contraction rate of the PVA-based film in a width direction thereof to be 30% to 80%.

9. The method of claim 1 , wherein an adhesive strength between the stretched PVA-based film and the stretched polyurethane film after the stretching of the film laminate is 2N/2 cm or less.

10. The method of claim 1 , wherein the separating of the PVA-based film from the thermoplastic polyurethane film is performed using a peel strength of 2N/2 cm or less.

11. The method of claim 1 , further comprising dyeing the film laminate with at least one of iodine and a dichroic dye, prior to the stretching of the film laminate.

12. The method of claim 1 , further comprising drying the stretched film laminate after the stretching of the film laminate.

Assignees

• Lg Chemical Ltd

Inventors

• Nam Sung-Hyun
• Jung Jong-Hyun
• Rah Kyun-Il
• Yu Hye-Min

Classifications

• G02B5/3033 Primary

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

• B32B2309/02

  Temperature · CPC title

• B32B2307/412

  Transparent · CPC title

• B29D7/01

  Films or sheets · CPC title

• B32B2331/04

  Polymers of vinyl acetate, e.g. PVA · CPC title