Method of producing a relief image for printing
View Patent ↗The present invention involves a method for making a relief image. A film that includes a carrier sheet and an imageable material is used to form a mask image that is opaque to a curing radiation. In one embodiment, the mask image is formed on the carrier sheet while in another embodiment, the mask image is formed on a receptor sheet. The mask image is then transferred to a photosensitive material, such as a flexographic printing plate precursor. The resulting assembly is exposed to the curing radiation resulting in exposed and unexposed areas of the photosensitive material. The carrier sheet or the receptor sheet may be removed from the mask image either before or after exposure to the curing radiation. Finally, the photosensitive material and mask image assembly is developed with a suitable developer to form a relief image.
1. A method of making a relief image, the method comprising:
(a) providing a film comprising an imageable material disposed on a carrier sheet;
(b) contacting the imageable material with a receptor sheet;
(c) forming a mask image on the receptor sheet by imagewise exposing the imageable material to infrared radiation to form exposed areas and transferring the exposed areas of the imageable material to the receptor sheet;
(d) removing the carrier sheet from the mask image;
(e) transferring the mask image to a photosensitive material that is sensitive to a curing radiation;
(f) exposing the photosensitive material to the curing radiation through the mask image to form an imaged article, wherein the mask image is substantially opaque to the curing radiation; and
(g) developing the imaged article to form the relief image.
2. The method of claim 1 wherein the receptor sheet comprises a support having an image-receiving side and a non-image side, the image-receiving side comprises a polymer coating having a thickness of from 2 μm to 20 μm.
3. The method of claim 1 wherein the receptor sheet comprises a support having an image-receiving side and a non-image side, the image-receiving side having a texturized surface.
4. The method of claim 3 wherein the image-receiving side has a texturized surface provided by inert particulate material at a coverage of from 100 to 500 particles/mm 2 .
5. The method of claim 1 wherein the step of forming the mask image on the receptor sheet comprises subliming a colorant in exposed areas to the receptor sheet.
6. The method of claim 1 wherein the step of forming the mask image on the receptor sheet comprises ablating the exposed areas to the receptor sheet.
7. The method of claim 1 wherein the step of forming the mask image on the receptor sheet comprises melt-stick or laser-induced film transfer of the exposed areas of the imageable material to the receptor sheet.
8. The method of claim 1 further comprising the step of removing the receptor sheet from the mask image.
9. The method of claim 8 wherein the step of removing the receptor sheet from the mask image occurs before the step of exposing the photosensitive material to the curing radiation.
10. The method of claim 8 wherein the step of removing the receptor sheet from the mask image occurs after the step of exposing the photosensitive material to the curing radiation.
11. The method of claim 1 wherein the film further comprises a release layer disposed between the carrier sheet and the imageable material.
12. The method of claim 1 wherein the film further comprises a barrier layer disposed between the carrier sheet and the imageable material.
13. The method of claim 12 wherein the barrier layer comprises poly(cyanoacrylate alkyl) or nitrocellulose, and an infrared absorbing dye.
14. The method of claim 1 wherein the imageable material comprises an infrared absorber.
15. The method of claim 1 wherein the imageable material comprises an ultraviolet absorber.
16. The method of claim 1 wherein the imageable material comprises a colorant.
17. The method of claim 1 wherein the imageable material comprises an adhesive binder.
18. The method of claim 1 wherein the step of removing the carrier sheet from the mask image occurs before the step of exposing the photosensitive material to the curing radiation.
19. The method of claim 1 wherein the step of removing the carrier sheet from the mask image occurs after the step of exposing the photosensitive material to the curing radiation.
20. The method of claim 1 for providing a flexographic printing plate wherein the photosensitive material comprises a flexographic precursor that comprises an ultraviolet-curable material.
21. The method of claim 1 wherein the curing radiation comprises ultraviolet radiation.
22. The method of claim 1 wherein the step of transferring the mask image to the photosensitive material comprises laminating the mask image to the photosensitive material.
23. The method of claim 1 wherein the step of exposing the photosensitive material to the curing radiation is performed in ambient pressure, with or without heat.