Method for manufacturing polarizing plate and adhesive composition for polarizing plate

1. A method for manufacturing a polarizing plate, the method comprising:

preparing a polarizer;

providing an adhesive composition on one surface of each of a first protective film and a second protective film;

laminating the first protective film on one surface of the polarizer, and laminating the second protective film on the other surface of the polarizer; and

adhering the first protective film, the polarizer and the second protective film by curing the adhesive composition through irradiating active energy rays on the first protective film side,

wherein the adhesive composition provided on one surface of the second protective film comprises a photoinitiator and a photosensitizer represented by the following Chemical Formula 2:

in Chemical Formula 2,

Ra and Rb are the same as or different from each other, and are hydrogen; deuterium; or a substituted or unsubstituted alkyl group;

Rc is a substituted or unsubstituted alkyl group;

m is an integer of 0 to 4; n is an integer of 0 to 2;

when m is 2 or greater, Ra the same as or different from each other;

when n is 2, Rb are the same as or different from each other;

the active energy rays have a maximum wavelength range of 380 nm to 420 nm;

light transmittance of the first protective film for the active energy rays is higher than light transmittance of the second protective film for the active energy rays.

2. The method for manufacturing a polarizing plate of claim 1 , wherein the first protective film has light transmission of 70% or greater at a wavelength of 400 nm.

3. The method for manufacturing a polarizing plate of claim 1 , wherein the first protective film or the second protective film is a triacetyl cellulose-based film.

4. The method for manufacturing a polarizing plate of claim 1 , wherein the second protective film is a retardation film.

5. The method for manufacturing a polarizing plate of claim 1 , wherein the second protective film and the first protective film have a thickness ratio of 1:3 to 3:1.

6. The method for manufacturing a polarizing plate of claim 1 , wherein the adhering of the first protective film, the polarizer and the second protective film further comprises irradiating active energy rays on the second protective film side after irradiating active energy rays on the first protective film side.

7. The method for manufacturing a polarizing plate of claim 1 , wherein the photosensitizer has a main absorption wavelength band of 360 nm to 420 nm.

8. The method for manufacturing a polarizing plate of claim 1 , wherein a content of the photosensitizer is 5% by weight or less based on a total weight of the adhesive composition.

9. The method for manufacturing a polarizing plate of claim 1 , wherein the adhesive composition comprises the photosensitizer and the photoinitiator in a content ratio of 1:1 to 1:10.

10. The method for manufacturing a polarizing plate of claim 1 , wherein the adhesive composition comprises any one or more of an epoxy compound and an oxetane compound.

11. The method for manufacturing a polarizing plate of claim 1 , wherein the adhesive composition has viscosity of greater than or equal to 50 cps and less than or equal to 200 cps at 25° C.

12. The method for manufacturing a polarizing plate of claim 1 , wherein the adhesive composition has a curing time (t 1 ) at which a maximum exothermic peak appears of 100 seconds or shorter when irradiating light at a wavelength of 380 nm to 420 nm and intensity of 100 W/cm 2 under an isothermal condition of 25° C. and analyzing a curing behavior using a photo-differential scanning calorimeter (Photo-DSC).