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