Plastic film

1. A plastic film, including:

a supporting substrate;

a first coating layer which is formed on one side of the supporting substrate and has an elastic modulus of 1,500 MPa or less;

a second coating layer which is formed on another side of the supporting substrate and has an elastic modulus of 2,000 MPa or more; and

at least one layer selected from: (i) a third coating layer located between the supporting substrate and the first coating layer; and (ii) a fourth coating layer located between the supporting substrate and the second coating layer, and

wherein each of (i) the first coating layer, (ii) the second coating layer, and (iii) the at least one layer selected from the third and the fourth coating layers, includes a photo-curable crosslinking copolymer of a photo-curable elastic polymer and a 3- to 6-functional acrylate monomer.

2. The plastic film according to claim 1 ,

wherein the plastic film includes a third coating layer and a fourth coating layer,

wherein an elastic modulus of the third coating layer is equal to or higher than the elastic modulus of the first coating layer,

and wherein an elastic modulus of the fourth coating layer is equal to or lower than the elastic modulus of the second coating layer.

3. The plastic film according to claim 2 , wherein the elastic modulus of the third coating layer is 2000 MPa or less.

4. The plastic film according to claim 2 , wherein the elastic modulus of the fourth coating layer is 1500 MPa or more.

5. The plastic film according to claim 1 , wherein the photo-curable crosslinking copolymer is a crosslinking copolymer in which a 1- to 2-functional acrylate monomer is crosslinked in addition to the 3- to 6-functional acrylate monomer and the photo-curable elastic polymer.

6. The plastic film according to claim 1 , wherein the photo-curable elastic polymer has an elongation of 15 to 200% as measured according to ASTM D638.

7. The plastic film according to claim 6 , wherein the photo-curable elastic polymer includes at least one selected from the group consisting of polycaprolactone, urethane acrylate polymers, and polyrotaxane, independently equally or differently.

8. The plastic film according to claim 7 , wherein the polyrotaxane includes a macrocycle connected with a lactone compound with a (meth)acrylate moiety introduced to the end thereof; a linear compound passing through the macrocycle; and stopper groups placed at both ends of the linear compound so as to prevent the macrocycle from dissociation.

9. The plastic film according to claim 1 , wherein each of the first coating layer, the second coating layer, and the at least one of the third and the fourth coating layers includes inorganic particles dispersed in the photo-curable crosslinking copolymer.

10. The plastic film according to claim 9 , wherein each of the first coating layer, the second coating layer, and the at least one of the third and the fourth coating layers includes 40 to 90 parts by weight of the photo-curable crosslinking copolymer and 10 to 60 parts by weight of the inorganic particles, based on 100 parts by weight of the first to the fourth coating layers.

11. The plastic film according to claim 1 , wherein the 3- to 6-functional acrylate monomer includes at least one selected from the group consisting of trimethylolpropane triacrylate (TMPTA), trimethylolpropaneethoxy triacrylate (TMPEOTA), glycerin-propoxylated triacrylate (GPTA), pentaerythritol tetraacrylate (PETA), and dipentaerythritol hexaacrylate (DPHA).

12. The plastic film according to claim 1 , including the first and the third coating layers on one side of the supporting substrate and the second coating layer on the other side of the supporting substrate, wherein the sum of the thicknesses of the first and the third coating layers is 50 to 300 μm and the thickness of the second coating layer is 50 to 300 μm.

13. The plastic film according to claim 12 , wherein a ratio of the thicknesses of the first coating layer and the third coating layer is 99:1 to 5:5.

14. The plastic film according to claim 1 , including the first coating layer on one side of the supporting substrate and the second and the fourth coating layer on the other side of the supporting substrate, wherein a sum of thicknesses of the second and the fourth coating layers is 50 to 300 μm and a thickness of the first coating layer is 50 to 300 μm.

15. The plastic film according to claim 14 , wherein the ratio of the thicknesses of the second coating layer and the fourth coating layer is 99:1 to 5:5.

16. The plastic film according to claim 1 , wherein the plastic film does not crack after a steel bead weighing 22 g is freely dropped ten times from a height of 60 cm thereto.

17. The plastic film according to claim 1 , wherein the plastic film shows a pencil hardness of 7H or more at the load of 1 kg.

18. The plastic film according to claim 1 , wherein a maximum distance between a plane and each edge or side of the plastic film is 1.0 mm or less, when the film is disposed on the plane after exposure to a temperature of 50° C. or more and a humidity of 80% or more for 70 hrs.

19. The plastic film according to claim 1 , further including at least one layer selected from the group consisting of a plastic resin film, an adhesive film, a release film, a conductive film, a conductive layer, a coating layer, a curable resin layer, a non-conductive film, a metal mesh layer, and a patterned metal layer on the first coating layer or the second coating layer.