Thin polarizer with excellent optical properties, manufacturing method therefor and polarizing plate including same
The present invention relates to a method of manufacturing a thin polarizer, including: forming a film laminate by attaching a polyvinyl alcohol-based film to at least one surface of a polymer film by using attraction force or an adhesive; swelling the film laminate so that a degree of swelling of the polyvinyl alcohol-based film is 0.36 to 0.44; dyeing at least one of iodine and a dichromatic dye on the film laminate; and stretching the film laminate.
1. A method of manufacturing a thin polarizer, comprising:
providing a prefabricated polyvinyl alcohol-based film;
providing a polymer film;
forming a film laminate by attaching the prefabricated polyvinyl alcohol-based film to at least one surface of the polymer film by using attraction force or an adhesive;
swelling the film laminate so that a degree of swelling of the polyvinyl alcohol-based film is 0.36 to 0.44;
dyeing at least one of iodine and a dichromatic dye on the film laminate; and
stretching the film laminate,
wherein the swelling of the film laminate is performed by a method of immersing the film laminate in water at 15° C. to 35° C., and
wherein the swelling of the film laminate is performed to satisfy the following Equation (2) when a swelling tank retention time is t seconds:
0.36≦0.105· t 0.5 ≦0.44 Equation (2).
2. The method of manufacturing a thin polarizer of claim 1 , wherein a thickness of the prefabricated polyvinyl alcohol-based film before attaching to the polymer film is 10 μm to 60 μm.
3. The method of manufacturing a thin polarizer of claim 1 , wherein the stretching is performed at a stretching magnification of 5 times to 15 times.
4. The method of manufacturing a thin polarizer of claim 1 , wherein the stretching is performed at a temperature of 45° C. to 55° C.
5. The method of manufacturing a thin polarizer of claim 1 , wherein the stretching is performed in a boric acid aqueous solution having a boric acid concentration of 1 to 5%.
6. The method of manufacturing a thin polarizer of claim 1 , further comprising:
after the stretching, separating the polymer film and the polyvinyl alcohol-based film.
7. The method of manufacturing a thin polarizer of claim 1 , further comprising:
after the stretching, drying the stretched film laminate.
8. A polyvinyl alcohol-based thin polarizer manufactured by the manufacturing method of claim 1 and having a thickness of 10 μm or less, simple substance transmittance of 40% to 45%, and a degree of polarization of 99.9% or more.
9. A polarizing plate comprising:
the polyvinyl alcohol-based thin polarizer of claim 8 .