Directly printed, coated panel

1. A panel for use as a wall, ceiling or floor panel, comprising

a carrier layer having a front side and a rear side, the carrier layer having on the front side at least the following layers in the following order:

a primer layer;

a decor layer comprising a polymerizable print color; and

a polymer layer having a front surface and a rear surface, wherein the polymer layer has a hardness gradient such that the hardness of the polymer layer continuously decreases with increasing depth from the front surface of the polymer layer,

wherein the print color of the decor layer is crosslinked with the polymer layer at an interface of the decor layer and the polymer layer.

2. The panel according to claim 1 , wherein the print color is based on a polymerizable acrylate.

3. The panel according to claim 1 , wherein the print color of the decor layer and the polymer layer have been cured in one common step together.

4. The panel according to claim 1 , wherein the decor layer has been applied by digital printing.

5. The panel according to claim 1 , wherein between the decor layer and the polymer layer no further layer is present.

6. The panel according to claim 1 , wherein the hardness gradient in general follows the following relation:

(−3.0· x )+ C≦Y ( x )≦(−0.2· x )+ C

wherein

x is the absolute value of the depth in micrometer of the coating as seen from the front surface of the coating;

Y(x) is the absolute value of the hardness in N/mm 2 at a specific depth x; and

C is the absolute value of the initial hardness in N/mm 2 of the coating at about x≈0-5 μm depth.

7. The panel according to claim 6 , wherein the hardness gradient corresponds in general to the following relation:

(−2.5· x )+ C≦Y ( x )≦(−0.4· x )+ C (−2,0· x )+ C≦Y ( x )≦(−0.6· x )+ C.

8. The panel according to claim 1 , wherein the polymer layer comprises a thickness of 20-300 μm.

9. The panel according to claim 1 , wherein the primer layer comprises a thickness of 20-300 μm.

10. The panel according to claim 1 , wherein the primer layer is no UV-curing lacquer.

11. The panel according to claim 1 , wherein the primer layer is based on an aqueous acrylate system.

12. The panel according to claim 1 , wherein the primer layer has been applied by a curtain coating method.

13. The panel according to claim 1 , wherein the polymer layer is based on one or more of the following acrylates: 1,6 hexandioldiacrylate, polyesteracrylate, polyurethanacrylacidester and dipropylenglycoldiacrylate.

14. The panel according to claim 1 , wherein the front surface of the polymer layer achieves in the grid cut test according to DIN ISO 2409 a grid cut parameter of at least 2.

15. A method for the coating of a panel, comprising the following steps:

(i) providing a carrier board;

(ii) applying a primer layer on the carrier board;

(iii) applying on the primer layer a decor layer including a polymerizable print color;

(iv) optionally: partially curing the print color;

(v) applying a first liquid coating agent onto the incompletely cured print color;

(vi) applying at least a second liquid coating agent onto the still wet first coating agent so that a partial mixing of the coating agents takes place; and

(vii) curing at least the applied coating agents and the print color in one common step together by using radiation, such that the cured coating agents comprise a hardness gradient, wherein the hardness of the cured coating agents decreases with increasing depth from a front surface of the resulting coating and wherein the print color of the decor layer is crosslinked with the first liquid coating agent at an interface of the decor layer and the first liquid coating agent.

16. The method according to claim 15 , wherein the primer layer in step (ii) is applied by a curtain coating method.

17. The method according to claim 15 , wherein the primer layer is dried after step (ii) and before step (iii).

18. The method according to claim 15 , wherein the decor layer is applied by digital printing.

19. The method according to claim 15 , wherein the coating agents are directly applied onto the decor layer.

20. The method according to claim 15 , wherein the hardness gradient in general corresponds to the following relation:

(−3.0· x )+ C≦Y ( x )≦(−0.2· x )+ C

wherein:

x is the absolute value of the depth in micrometer of the coating as seen from the front surface of the coating;

Y(x) is the absolute value of the hardness in N/mm 2 at a specific depth x; and

C is the absolute value of the initial hardness in N/mm 2 of the coating at about x≈0-5 μm depth.

21. The method according to claim 15 , wherein the hardness gradient corresponds in general to the following relation:

(−2.5· x )+ C≦Y ( x )≦(−0.4· x )+ C.

22. The method according to claim 15 , wherein the coating agents comprise a total thickness of 20-300 μm.

23. The method according to claim 15 , wherein the primer layer comprises a thickness of 20-300 μm.

24. The method according to claim 15 , wherein the primer layer is no UV-curing lacquer.

25. The method according to claim 15 , wherein the coating agents are based on one or more of the following acrylates: 1,6 hexandioldiacrylate, polyesteracrylate, polyurethanacrylacidester and dipropylenglycoldiacrylate.

26. The method according to claim 1 , wherein the decor layer consists of print color.