Adhesive composition for polarizing plate, polarizing plate including the same, and optical display including the same

An adhesive composition for polarizing plates, comprising a (meth)acrylic copolymer and a curing agent,

• wherein the (meth)acrylic copolymer is prepared by copolymerization of a monomer mixture, the monomer mixture comprising:
• about 4 wt % to about 20 wt % of a hydroxyl group-containing (meth)acrylic monomer,
• a tertiary amine group-containing (meth)acrylic monomer, and
• a monomer having a homopolymer glass transition temperature (Tg) of about 100° C. or greater, the monomer having a homopolymer Tg of about 100° C. or greater comprising at least one of (meth)acryloyl morpholine or isobornyl (meth)acrylate and being present in the monomer mixture in an amount of about 5 wt % to about 19 wt %,
• wherein the monomer mixture comprises the hydroxyl group-containing (meth)acrylic monomer and the tertiary amine group-containing (meth)acrylic monomer in a weight ratio of about 500:1 to about 1:1,
• the adhesive composition having a gel fraction of about 50% or greater after aging for 12 hours, as calculated by Equation 1:
• Gel Fraction=(WC−WA)/(WB−WA)×100 Equation 1
• wherein:
• WA is a weight of a wire mesh (200 mesh);
• WB is a total weight of the wire mesh and a specimen of an adhesive film for polarizing plates, the adhesive film being obtained by depositing 1.0 g of the adhesive composition for polarizing plates to a thickness of 20 μm on a release film, followed by aging the adhesive composition for polarizing plates on the release film at 23° C. and 55% RH for a period of time;
• and
• WC is a total weight of the wire mesh and the adhesive film after placing the wire mesh and the adhesive film in a sample bottle, adding 50 cc of ethyl acetate to the sample bottle, allowing the sample bottle to stand for 1 day, and drying the sample bottle at 90° C. for 24 hours.