Casting papers and their methods of formation and use
Methods are generally disclosed for forming and using a casting paper. In one embodiment, the casting paper can be made by coating a first surface of a base sheet with a release coating such that the release coating covers the entire first surface of the base sheet. A printed release coating is then applied on a portion of the first release coating, and is dried or cured as needed to form the casting paper having a textured surface defined by elevated areas corresponding to the printed release coating and valley areas corresponding to exposed areas of the printed release coating. In another embodiment, the casting paper can be made by first printing a base sheet with a patterned, structured coating, then coating over the patterned, structured coating with a release coating such that the release coating covers at least the unprinted areas of the base sheet. The casting paper can be used to form a texturized surface in a substrate.
1. A method of forming a casting paper, the method comprising:
coating a first surface of a base sheet with a release coating such that the release coating covers the entire first surface of the base sheet, wherein the release coating comprises a first curable polymeric material and a first release agent;
curing the release coating;
applying a printed release coating on a portion of the release coating, wherein the print coating comprises a second curable polymeric material and a second release agent; and
curing the printed release coating to form the casting paper having a textured surface defined by elevated areas corresponding to the printed release coating and valley areas corresponding to exposed areas of the release coating
wherein the release coating and the printed release coating are crosslinked upon curing so as to not melt at a transfer temperature of about 200° F. to about 400° F.
2. The method as in claim 1 , wherein the printed release coating is flexographically printed onto the release coating.
3. The method as in claim 1 , wherein the printed release coating is offset printed onto the release coating.
4. The method as in claim 1 , wherein the printed release coating is rotary screen printed onto the release coating.
5. The method as in claim 1 , wherein curing the release coating comprises exposing the release coating to e-beam radiation.
6. The method as in claim 1 , wherein curing the printed release coating comprises exposing the printed release coating to e-beam radiation.
7. The method as in claim 1 , wherein the first curable polymeric material and/or the second curable polymeric material comprises a curable monomer, a curable polymer, and a cross-linking agent.
8. The method as in claim 7 , wherein the curable monomer comprises trimethylolpropane triacrylate.
9. The method as in claim 7 , wherein the curable polymer comprises an acrylic polymer.
10. The method as in claim 7 , wherein the crosslinking agent comprises an aziridine cross-linker.
11. The method as in claim 1 , wherein the first curable polymeric material and the second curable polymeric material have substantially the same composition.
12. The method as in claim 1 , wherein the first release agent and/or the second release agent comprises lauryl acrylate.
13. The method as in claim 1 , wherein the first release agent and the second release agent have substantially the same composition.
14. The method as in claim 1 , wherein the print coating is applied to a thickness of about 10 μm to about 1 mm.
15. The method as in claim 14 , wherein the textured pattern corresponds to the negative image of the pattern to be cast onto a substrate.
16. The method as in claim 1 , further comprising:
coating a thermoplastic layer onto the textured surface of the casting paper;
positioning the thermoplastic layer adjacent to a substrate;
heat transferring the thermoplastic layer to the substrate; and
removing the casting paper from the substrate, such that the thermoplastic layer is transferred to the substrate while the release coating and the printed release coating remains on the base sheet of the casting paper.
17. The method as in claim 16 , wherein heat transferring the thermoplastic layer to the substrate comprises applying heat at a transfer temperature of about 125° C. to about 200° C. to the base sheet of the casting paper.
18. The method as in claim 1 , further comprising:
heating a thermoplastic surface on a substrate;
pressing the texturized surface of the casting paper onto the thermoplastic surface; and
removing the casting paper from the thermoplastic surface such that the release coating and the printed release coating remains on the base sheet of the casting paper.