UV-curable coating compositions with self-healing capabilities, coating films, and methods of producing coating films

1. A coating composition comprising a (meth)acrylate binder resin, a UV initiator, an organic solvent, and silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage,

wherein the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage comprise a compound of Chemical Formula 2:

wherein R 3 is hydrogen or a methyl, R 4 is any divalent organic functional group, p is an integer of 1 to 5, q is an integer of 1 to 10, a is an integer equal to or greater than 1, b is an integer of 2 to 9, and “silica” represents a silica particle.

2. The coating composition in accordance with claim 1 , wherein the (meth)acrylate binder resin comprises at least one polymer resin selected from the group consisting of a urethane (meth)acrylate resin and a hydroxyalkyl (meth)acrylate resin modified with a polylactone compound.

3. The coating composition in accordance with claim 2 , wherein the hydroxyalkyl (meth)acrylate resin modified with a polylactone compound comprises a compound of Chemical Formula 1:

wherein, in Chemical Formula 1, R 3 is hydrogen or a methyl, p is an integer of 1 to 5, q is an integer of 1 to 10, and b is an integer of 2 to 9.

4. The coating composition in accordance with claim 2 , wherein the urethane (meth)acrylate resin comprises a reaction product between an organic isocyanate compound having at least two isocyanate groups per molecule and a hydroxyalkyl (meth)acrylate modified with a polylactone compound.

5. The coating composition in accordance with claim 1 , comprising:

20% to 80% by weight of the (meth)acrylate binder resin;

1% to 10% by weight of the UV initiator;

5% to 50% by weight of the organic solvent; and

1% to 30% by weight of the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage.

6. The coating composition in accordance with claim 1 , further comprising a UV-curable monomer.

7. The coating composition in accordance with claim 6 , wherein the UV-curable monomer comprises at least one multifunctional acrylate compound selected from the group consisting of pentaerythritol tri/tetraacrylate (PETA), dipentaerythritol hexa-acrylate (DPHA), trimethylol propane triacrylate (TMPTA), and hexamethylene diacrylate (HDDA).

8. The coating composition in accordance with claim 1 , further comprising at least one additive selected from the group consisting of a leveling agent and a dispersion stabilizer.

9. A coating film comprising a cured product of a coating composition of claim 1 .

10. The coating film in accordance with claim 9 , wherein the (meth)acrylate binder resin and the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage are chemically bonded.

11. The coating film in accordance with claim 9 , wherein the (meth)acrylate binder resin and the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage form a crosslinked network structure.

12. The coating film in accordance with claim 9 , further comprising a UV-curable monomer.

13. A method of producing a coating film, which comprises the steps of:

mixing a (meth)acrylate binder resin, a UV initiator, an organic solvent, and a silica particle having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage;

applying the mixture on a substrate and drying it; and

subjecting the dried mixture to UV curing,

wherein the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage comprise a compound of Chemical Formula 2:

wherein R 3 is hydrogen or a methyl, R 4 is any divalent organic functional group, p is an integer of 1 to 5, q is an integer of 1 to 10, a is an integer equal to or greater than 1, b is an integer of 2 to 9, and “silica” represents a silica particle.

14. The method of producing a coating film in accordance with claim 13 , further comprising a step of preparing the (meth)acrylate binder resin.

15. The method of producing a coating film in accordance with claim 14 , wherein the step of preparing the (meth)acrylate binder resin comprises triggering a reaction between an organic isocyanate compound having at least two isocyanate groups per molecule and a polylactone-modified hydroxyalkyl (meth)acrylate resin to produce a urethane (meth)acrylate resin.

16. The method of producing a coating film in accordance with claim 13 , further comprising a step of preparing the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage.

17. The method of producing a coating film in accordance with claim 16 , wherein the step of preparing the silica particles having a polylactone-modified hydroxyalkyl (meth)acrylate linked to their surface through a urethane linkage comprises subjecting silica particles to a reaction with a diisocyanate compound, and subjecting a product resulting from the reaction between the silica particles and the diisocyanate compound to a reaction with a (meth)acrylate compound.

18. The method of producing a coating film in accordance with claim 13 , further comprising a step of adding a UV-curable monomer to the mixture.

19. The method of producing a coating film in accordance with claim 13 , further comprising a step of adding at least one additive selected from the group consisting of a leveling agent and a dispersion stabilizer to the mixture.