Cross-linkable composition

1. An optical laminate comprising an optical film; and a pressure-sensitive adhesive layer formed on one side of the optical film and including a cross-linked product of the cross-linkable composition, the cross-linkable composition comprising

an acrylic polymer;

an ionic compound having an alkali metal cation; and a compound of Formula 1 below, and having a curing rate of 30% or more according to Equation 1 below,

wherein, R 1 to R 4 are each independently a hydrogen atom or an alkyl group,

curing rate=B/A×100% [Equation 1] wherein, A is a mass in g before immersing the cross-linkable composition, in which a cross-linking agent of the acrylic polymer is blended, in an amount of 1 part by weight or less relative to 100 parts by weight f the acrylic polymer, to the cross-linkable composition comprising the ionic compound in a ratio of 3 parts by weight or more relative to 100 parts by weight of the acrylic polymer, or a cross-linked product of the composition in ethyl acetate, and B is a dry mass in g of insoluble contents recovered after immersing the cross-linkable composition or the cross-linked product of the composition in ethyl acetate at room temperature for 24 hours, where the insoluble contents are components sieved by a sieve of 200 meshes, wherein

the cross-linkable composition does not comprise a metal chelate cross-linking agent and a metal-containing cross-linking catalyst, in which the optical film comprising a polyvinyl alcohol polarizer, the polyvinyl alcohol polarizer comprising potassium component and zinc component, and a ratio of the potassium component to the zinc component is 0.2 to 6.

2. The optical laminate according to claim 1 , wherein the acrylic polymer comprises a polymerized unit of an alkyl (meth)acrylate monomer and a polymerized unit of a carboxyl group-containing monomer.

3. The optical laminate according to claim 2 , further comprising an epoxy cross-linking agent or an aziridine cross-linking agent.

4. The optical laminate according to claim 1 , wherein the alkali metal cation is a lithium cation.

5. The optical laminate according to claim 1 , wherein the ionic compound comprises an anion of Formula 2 below:

[X(YO m R f ) n ] − [Formula 2] wherein, X is nitrogen or carbon, Y is carbon or sulfur, R f is a perfluoroalkyl group, m is 1 or 2, and n is 2 or 3.

6. The optical laminate according to claim 1 , wherein the ionic compound comprises any one anion of Formulas 3 to 5 below:

[OSO 2 CnF 2+1 ] −   [Formula 3]

[N(SO 2 C n F 2+1 ) 2 ] −   [Formula 4]

[C(SO 2 C n F 2+1 ) 3 ] −   [Formula 5]

wherein, n is a number in a range of 1 to 4.

7. The optical laminate according to claim 1 , wherein the cross-linkable composition comprises the ionic compound which is in an amount of 0.001 to 20 parts by weight relative to 100 parts by weight of the acrylic polymer.

8. The optical laminate according to claim 1 , wherein the cross-linkable composition comprises the ionic compound which is in an amount of 3 parts by weight or more relative to 100 parts by weight of the acrylic polymer.

9. The optical laminate according to claim 1 , wherein in Formula 1, R 1 and R 2 are each independently an alkyl group having 1 to 4 carbon atoms, and R 3 and R 4 are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

10. The optical laminate according to claim 9 , wherein any one of R 3 and R 4 is a hydrogen atom and the other is an alkyl group having 1 to 4 carbon atoms.

11. The optical laminate according to claim 1 , wherein the cross-linkable composition comprises the compound of Formula 1 which is in an amount of 0.01 to 30 parts by weight relative to 100 parts by weight of the ionic compound.

12. The optical laminate according to claim 1 , further comprising a cross-linking agent.

13. The optical laminate according to claim 12 , wherein the cross-linking agent is an isocyanate cross-linking agent, an epoxy cross-linking agent or an aziridine cross-linking agent.

14. The optical laminate according to claim 12 , wherein the cross-linkable composition comprises the cross-linking agent which is in an amount of 10 parts by weight or less relative to 100 parts by weight of the acrylic, polymer.

15. The optical laminate according to claim 12 , wherein the cross-linkable composition comprises the cross-linking agent which is in an amount of 1 part by weight or less relative to 100 parts by weight of the acrylic, polymer.

16. A display device comprising a display panel to which the optical laminate of claim 1 is attached via the pressure-sensitive adhesive layer.

17. The optical laminate according to claim 2 , wherein the acrylic polymer further comprises a polymerized unit of an aromatic group-containing monomer represented by the following formula 6:

in Formula 6, R 1 represents hydrogen or an alkyl group, A represents an alkylene group, n represents an integer in a range of 0 to 3, Q represents a single bond, —O—, —S— or an alkylene group, and P represents an aryl group.