ADHESIVE COMPOSITION FOR POLARIZING PLATE, POLARIZING PLATE, AND OPTICAL DISPLAY DEVICE

1 . An adhesive composition for polarizing plates, comprising: a polyvinyl alcohol-based resin, a crosslinking agent having a primary amine group (—NH 2 ) or a secondary amine group (—NH—), and an epoxy-based compound having an alkylene oxide group.

2 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the crosslinking agent having a primary amine group or a secondary amine group comprises at least one ethylene imine-based crosslinking agent.

3 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the crosslinking agent: the epoxy-based compound having an alkylene oxide group are comprised in a weight ratio of about 1:1 to about 1:15.

4 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the alkylene oxide group is *—[—O—R—]—* (* being a linking site and R is a linear chain or branched chain C 2 to C 4 alkylene group).

5 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the epoxy-based compound having an alkylene oxide group comprises a compound represented by Chemical Formula 1:

R 1 —[—O—R—] n —O—R 2 ,  [Chemical Formula 1]

where R is a linear chain or branched chain C 2 to C 4 alkylene group;

R 1 and R 2 are each independently an epoxide group or an epoxide group-containing group; and

n is an integer of 1 to 30.

6 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the epoxy-based compound having an alkylene oxide group comprises at least one of ethylene glycol diglycidyl ether; poly(ethylene glycol) diglycidyl ether; propylene glycol diglycidyl ether; and poly(propylene glycol) diglycidyl ether.

7 . The adhesive composition for polarizing plates as claimed in claim 1 , wherein the adhesive composition comprises:

100 parts by weight of the polyvinyl alcohol-based resin;

about 0.1 parts by weight to about 50 parts by weight of the crosslinking agent having a primary amine group or a secondary amine group; and

about 1 part by weight to about 100 parts by weight of the epoxy-based compound having an alkylene oxide group.

8 . A polarizing plate comprising:

a polarizer;

a first liquid crystal retardation layer stacked on a lower surface of the polarizer; and

a first bonding layer bonding the polarizer to the first liquid crystal retardation layer,

wherein the first bonding layer comprises a bonding layer formed of the adhesive composition for polarizing plates as claimed in claim 1 .

9 . The polarizing plate as claimed in claim 8 , wherein the first liquid crystal retardation layer comprises an aromatic ring-containing liquid crystal compound.

10 . The polarizing plate as claimed in claim 8 , further comprising:

a second bonding layer and a second liquid crystal retardation layer formed on a lower surface of the first liquid crystal retardation layer.

11 . The polarizing plate as claimed in claim 10 , wherein the second liquid crystal retardation layer comprises an aromatic ring-containing liquid crystal compound.

12 . The polarizing plate as claimed in claim 10 , wherein the second bonding layer is formed of an adhesive composition for polarizing plates comprising: a polyvinyl alcohol-based resin; a crosslinking agent having a primary amine group or a secondary amine group; and an epoxy-based compound having an alkylene oxide group.

13 . The polarizing plate as claimed in claim 12 , wherein the crosslinking agent having a primary amine group or a secondary amine group comprises at least one ethylene imine-based crosslinking agent.

14 . The polarizing plate as claimed in claim 12 , wherein the alkylene oxide group-containing epoxy compound comprises at least one of ethylene glycol diglycidyl ether; poly(ethylene glycol) diglycidyl ether; propylene glycol diglycidyl ether; and poly(propylene glycol) diglycidyl ether.

15 . An optical display device comprising the polarizing plate as claimed in claim 8 .