Method for producing a decorated sheet and use thereof
Decorated sheets on the basis of cellulose non-woven fabrics, such as paper, for the production of decorated laminates are impregnated with synthetic resins. Consequently, their sizes are changed, they become brittle and are not water-resistant in the laminate. In the method according to the invention the printed or unprinted non-woven fabrics are impregnated with an aqueous dispersion of a polymer which is cross-linkable by UV radiation, dried and optionally printed and finally irradiated with UV radiation. The decorated sheets thus obtained are water-resistant in the laminate and can be coiled up and stored after each process step.
1. Method for producing a decorated sheet comprising the following steps, including a step of cross-linking/curing by UV radiation, in sequential order:
providing an unprinted non-woven fabric of cellulosic fibers;
impregnating the unprinted non-woven fabric with an aqueous dispersion of a polymer which is cross-linkable by UV radiation to yield an impregnated, unprinted non-woven fabric;
removing the aqueous dispersion medium from the impregnated unprinted non-woven fabric by drying to yield a dried, impregnated, unprinted, non-woven fabric;
printing a decoration on one side of the dried, impregnated, unprinted, non-woven fabric prior to said cross-linking/curing by UV radiation to yield a printed, dried, impregnated, non-woven fabric; and
curing the polymer in the printed, dried, impregnated, uncured, non-woven fabric by said cross-linking by means of UV irradiation.
2. Method according to claim 1 , characterized in that the polymer which is cross-linkable by UV radiation is a copolymer comprising at least urethane and ethylenically unsaturated units.
3. Method according to claim 2 , characterized in that the polymer which is cross-linkable by UV radiation further comprises ester units.
4. Method according to claim 3 , characterized in that the non-woven fabric is paper.
5. Method according to claim 3 , characterized in that the aqueous dispersion has a solids content of at least 35 wt. %.
6. Method according to claim 3 , characterized in that the drying process is implemented by infrared radiation, heated air, microwaves, and/or heated rollers.
7. Method according to claim 3 , characterized in that the printing process is implemented by offset printing, flexographic printing and/or a digital printing process.
8. Method according to claim 3 , characterized in that:
the non-woven fabric is paper;
the aqueous dispersion has a solids content of at least 35 wt. %;
the drying process is implemented by infrared radiation, heated air, microwaves, and/or heated rollers; and
the printing process is implemented by offset printing, flexographic printing and/or a digital printing process.
9. Method according to claim 2 , characterized in that the non-woven fabric is paper.
10. Method according to claim 2 , characterized in that the aqueous dispersion has a solids content of at least 35 wt.-%.
11. Method according to claim 2 , characterized in that the drying process is implemented by infrared radiation, heated air, microwaves, and/or heated rollers.
12. Method according to claim 2 , characterized in that the printing process is implemented by offset printing, flexographic printing and/or a digital printing process.
13. Method according to claim 2 , characterized in that:
the non-woven fabric is paper;
the aqueous dispersion has a solids content of at least 35 wt. %;
the drying process is implemented by infrared radiation, heated air, microwaves, and/or heated rollers; and
the printing process is implemented by offset printing, flexographic printing and/or a digital printing process.
14. Method according to claim 1 , characterized in that the non-woven fabric is paper.
15. Method according to claim 1 , characterized in that the aqueous dispersion has a solids content of at least 35 wt.-%.
16. Method according to claim 1 , characterized in that the drying process is implemented by infrared radiation, heated air, microwaves, and/or heated rollers.
17. Method according to claim 1 , characterized in that the printing process is implemented by offset printing, flexographic printing and/or a digital printing process.
18. Method according to claim 17 , characterized in that the printing process is implemented by means of an ink jet, transfer or laser printing process.
19. The method of claim 1 further comprising, after said curing, attaching the non-woven fabric onto a carrier plate, followed by applying a cover layer over the non-woven fabric.
20. The method of claim 1 wherein the non-woven fabric is paper and the method further comprises, after said curing, attaching the non-woven fabric onto a carrier plate, followed by applying a cover layer over the non-woven fabric.
21. The method of claim 1 wherein the printing is with a UV curable printing ink and the cross-linking by means of UV irradiation which cures the polymer in the fabric also cures the UV curable printing ink.
22. The method of claim 1 consisting of the stated steps of the providing, the impregnating, the removing, the printing, and the curing.
23. Method for producing a decorated sheet comprising the following steps, including a step of cross-linking/curing by UV radiation, in sequential order:
providing an unprinted non-woven fabric of cellulosic fibers;
impregnating the unprinted non-woven fabric with an aqueous dispersion of a polymer which is cross-linkable by UV radiation to yield an impregnated, unprinted non-woven fabric;
removing the aqueous dispersion medium from the impregnated unprinted non-woven fabric by drying to yield a dried, impregnated, unprinted, non-woven fabric;
printing a decoration on one side of the dried, impregnated, unprinted, non-woven fabric prior to any curing to yield a printed, dried, impregnated, uncured, non-woven fabric; and
curing the polymer in the printed, dried, impregnated, uncured, non-woven fabric by said cross-linking by means of UV irradiation.