Patent ID: 8337961

Claim:
An acrylic pressure-sensitive adhesive composition for polarizing plates, comprising a (meth)acrylic copolymer comprising an alkyl(meth)acrylic acid ester monomer, in which alkyl has 2 to 14 carbon atoms, and a copolymerizable monomer containing a photo-initiator group, wherein, the composition forms a crosslinked structure through the reaction of the photo-initiator group, wherein, the composition after forming the crosslinked structure has a gel fraction, represented by Equation 1, of 10 to 55% and a swelling ratio, represented by Equation 2, of 30 to 110, and wherein, the composition after forming the crosslinked structure comprises a sol that is capable of being eluted with ethyl acetate and that has a weight average molecular weight of 600,000 or more: Gel fraction(%)= B/A× 100 (1) Swelling ratio= C/B (2) wherein, A represents weight of the composition after forming the crosslinked structure, B represents dry weight of insoluble content after depositing the composition after forming the crosslinked structure in ethyl acetate at ambient temperature for 48 hours, and C represents weight of insoluble content swollen with ethyl acetate after depositing the composition after forming the crosslinked structure in ethyl acetate at ambient temperature for 48 hours.