Optical Laminate
The present application relates to an optical laminate. The present application can provide an optical laminate which can have stable durability even at a high temperature, particularly an ultra-high temperature of about 100° C. or higher, and that base material adhesiveness is excellent, other physical properties required for the optical laminate are also excellent, and even in the case of being disposed adjacent to the electrode, corrosion of the relevant electrode or the like is not induced.
1 . An optical laminate comprising
an optical film; and
a pressure-sensitive adhesive layer formed on a side of the optical film,
wherein the pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive polymer including
a first alkyl (meth)acrylate unit having an alkyl group with 4 or more carbon atoms,
a second alkyl (meth)acrylate unit having an alkyl group with 3 or less carbon atoms,
an aromatic group-containing monomer unit and
a hydroxyl group-containing monomer unit, and
wherein the pressure-sensitive adhesive polymer includes the first alkyl (meth)acrylate unit in an amount of 45 wt % to 70 wt %, and 30 to 65 parts by weight of the second alkyl (meth)acrylate unit, 20 to 45 parts by weight of the aromatic group-containing monomer unit, and 4 to 8 parts by weight of the hydroxyl group-containing monomer unit, relative to 100 parts by weight of the first alkyl (meth) acrylate unit.
2 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive layer has a storage modulus at room temperature of 0.07 MPa or more.
3 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive layer has a gel fraction of 80 wt % or more according to Equation 1 below:
Gel fraction= B/A× 100 [Equation 1]
wherein, A is a mass (unit: g) of the pressure-sensitive adhesive layer before immersing the pressure-sensitive adhesive layer in ethyl acetate, and B represents the dry mass (unit: g) of an insoluble fraction recovered after immersing the pressure-sensitive adhesive layer in ethyl acetate at room temperature for 24 hours.
4 . The optical laminate according to claim 1 , wherein the optical film is a polarizer.
5 . The optical laminate according to claim 4 , wherein the polarizer is a polyvinyl alcohol polarizer containing a potassium component and a zinc component.
6 . The optical laminate according to claim 5 , wherein the polyvinyl alcohol polarizer comprises the potassium component (K) and the zinc component (Zn) in a weight ratio (K/Zn) of 0.2 to 6.
7 . The optical laminate according to claim 5 , wherein the polyvinyl alcohol polarizer comprises the potassium component in an amount of 0.1 to 2 wt %.
8 . The optical laminate according to claim 5 , wherein the polyvinyl alcohol polarizer comprises the zinc component in an amount of 0.1 to 0.5 wt %.
9 . The optical laminate according to claim 1 , wherein the second alkyl (meth)acrylate unit is a methyl acrylate unit.
10 . The optical laminate according to claim 1 , wherein the aromatic group-containing monomer forming the aromatic group-containing monomer unit is represented by Formula 1 below:
wherein, R 1 is hydrogen or an alkyl group, A is an alkylene group, n is an integer in a range of 0 to 3, Q is a single bond, —O—, —S— or an alkylene group, and P is an aromatic substituent.
11 . The optical laminate according to claim 1 , wherein the hydroxyl group-containing monomer unit is a hydroxyalkyl (meth)acrylate unit having a hydroxyalkyl group having a carbon number in a range of 3 to 6.
12 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive polymer further comprises carboxyl group-containing monomer units and an amount of carboxyl group-containing monomer units in the pressure-sensitive adhesive polymer is 1 wt % or less.
13 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive layer further comprises a crosslinking agent for crosslinking the pressure-sensitive adhesive polymer.
14 . A display device comprising a display panel to which the optical laminate of claim 1 is attached via the pressure-sensitive adhesive layer of the optical laminate.
15 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive layer has a storage modulus at room temperature of 0.07 MPa to 0.2 MPa.
16 . The optical laminate according to claim 1 , wherein the pressure-sensitive adhesive layer has a gel fraction of 80 wt % to 95 wt % according to Equation 1 below:
Gel fraction= B/A× 100 [Equation 1]
wherein, A is a mass (unit: g) of the pressure-sensitive adhesive layer before immersing the pressure-sensitive adhesive layer in ethyl acetate, and B represents the dry mass (unit: g) of an insoluble fraction recovered after immersing the pressure-sensitive adhesive layer in ethyl acetate at room temperature for 24 hours.