METHOD FOR MANUFACTURING A DECORATIVE FOIL AND A PANEL COMPRISING SUCH FOIL

Abstract

A method for manufacturing a decorative foil may involve providing a thermoplastic carrier layer. An ink receiving layer may be provided to the carrier layer. A decorative pattern may be formed on the carrier layer by performing a digital printing operation wherein droplets of aqueous inks having a volume smaller than 100 pL are jet to the carrier layer, more particularly to the ink receiving. The ink receiving layer may comprise a binding agent, preferably different from an acrylic copolymer, and/or silica.

Claims

1. A method for manufacturing a decorative foil, the method comprising: providing a thermoplastic carrier layer; providing an ink receiving layer to tithe carrier layer; and forming a decorative pattern on the carrier layer by performing a digital printing operation wherein droplets of aqueous inks having a volume smaller than 100 pL are jet to the ink receiving layer; wherein the ink receiving layer comprises a binding agent.

2. The method of claim 1, the ink comprise a binding agent.

3. The method of claim 1, wherein the ink receiving layer comprises silica pigments having a BET value lower than 350 m.sup.2/g.

4. The method of claim 1, wherein the ink receiving layer comprises from 25% to 75% by weight of silica pigments.

5. The method of claim 1, wherein the ink receiving layer comprises pigments and binder with a pigment to binder ratio of 0.85 or more.

6. The method of claim 1, wherein the ink receiving layer has a pH of less than 6.

7. The method of claim 1, wherein the ink receiving layer comprises a cationic flocculating agent.

8. The method of claim 1, wherein the ink receiving layer comprises citric acid.

9. The method of claim 1, wherein providing the ink receiving layer to the carrier layer comprises, a first substep wherein a first substance including, pigment and binder is applied to the carrier layer, and a second substep wherein a second substance including at least binder is applied to the carrier layer and the pigment to binder ratio of the second substance applied in the second substep is lower than the pigment to binder ratio of the first substance applied in the first substep.

10. The method of claim 1, wherein the ink receiving layer comprises at least a cationic binding agent.

11. The method of claim 1, wherein the ink receiving layer comprises a waterborne aliphatic polyurethane dispersion as the binding agent.

12. The method of claim 1, wherein the ink receiving layer comprises silica pigments having a d50 particle size as determined by the laser light scattering granulometry technique, according to 13320-1, lower than 5.5 micrometer.

13. The method of claim 1, wherein the ink receiving layer comprises silica gel or fumed silica.

14. The method of claim 1, wherein the aqueous ink comprises a terpolymer of vinyl chloride, vinyl acetate and ethylene as a binding agent.

15. A method for manufacturing a decorative panel, having a substrate, a decorative pattern provided on a carrier layer and a transparent wear layer, wherein the method at least comprises laminating the wear layer on top of a decorative foil obtained through the method of claim 1, the decorative foil comprising the decorative pattern and the carrier layer.

Description

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0059] With the intention of further illustrating the invention, here below, without any limitative character, some comparative and preferred embodiments are listed in two example series.

Example Series 1

[0060] A rigid PVC foil of 0.07 mm thickness was surface activated with corona treatment and was provided with an inkjet receiver layer having a vinyl chloride vinyl acetate binding agent, more particularly a terpolymer of vinyl chloride, vinyl acetate and ethylene, and silica at a pigment to binder ratio PB as indicated in the first and second column of the below table. The silica applied was of the precipitated type with a d50 particle size of 5 micrometer. The inkjet receiver coating further comprised 15 percent by weight of a flocculating agent as mentioned in the third column. In some embodiments the inkjet receiver coating was applied using two substeps (“dual layer”) in accordance with the preferred embodiment listed above. In such case, the substance applied in the second substep did not contain silica pigments.

[0061] Each prepared rigid PVC foil was then digitally printed with an aqueous ink and laminated to a transparent PVC wear layer of 0.5 mm thickness. The lamination was performed for 10 seconds at 165° C. and at a pressure of 1 kg/cm.sup.2 followed by 165 seconds at 165° C. and at a pressure of 4 kg/cm.sup.2.

[0062] The prepared foil, the print and the resulting laminated product were examined for dustiness, image quality, adhesion or lamination strength and ink loading capacity. Image quality is analyzed visually after printing a technical image with a plotter, more particularly a plotter commercially available from the company Epson. These properties were qualified on a scale from 0 to 5, resembling bad to perfect. The sum of the scores on all of the four properties provides a ranking of the several setups, where the highest sum is the most technically desirable result. However any result having a sum equal to 15 and more may be acceptable for an industrial process.

TABLE-US-00001 Binder PB-ratio   agent Duallayer Dust Images Adhesion Inkload None 0 / No 5 0 0 0 5 VCVA 0 / No 5 0 5 1 11 Yes 11 CaCl2 No 1 4 11 Yes 11 Cirtic No 1 5 12 acid Yes 12 0.5 / No 4 2 3 2 11 Yes 5 4 3 14 CaCl2 No 4 5 2 2 13 Yes 5 3 3 Cirtic No 1 4 2 12 acid Yes 5 5 3 18 1 / No 3 2 2 4 11 Yes 5 4 5 CaCl2 No 3 5 1 4 13 Yes 5 3 5 Cirtic No 3 5 3 4 15 acid Yes 5 5 5 20 2 / No 1 3 1 4 9 Yes 4 3 5 15 CaCl2 No 1 1 4 11 Yes 4 3 5 17 Cirtic No 1 5 2 4 12 acid Yes 4 4 5 18 Legend 0 Bad 5 Perfect indicates data missing or illegible when filed

[0063] From the results it can be gleaned that the higher pigment to binder ratio gives a higher dustiness, unless “dual layer” is applied. The image quality grows with higher pigment to binder ratio and the adhesion generally drops. The “dual layer” and the availability of a cationic flocculating agent like citric acid lifts the adhesion or lamination strength back up.

[0064] The best inkjet receiver coating from the results is the one having a pigment to binder ratio of 1, having been applied in two substeps (“dual layer”), in accordance with the preferred embodiment listed above, and comprising citric acid. Several other results are also well acceptable.

[0065] Depending on ink load and the desired image quality, other coatings from the present series may be acceptable. For example, with low ink load, a coating having a pigment to binder ratio of zero, or nearly zero, may be acceptable, and such is not excluded in the context of the present invention, as, in some cases, the criteria of dust creation and/or adhesion may be considered the most important.

Example Series 2

[0066] It was proceeded similarly as in example series 1 above, but instead off a vinyl chloride-vinyl acetate binding agent, a polyurethane binding agent has been applied. The results are summarized in the same way in the below table.

TABLE-US-00002 Binder PB-ratio   agent Duallayer Dust Images Adhesion Inkload None 0 / No 5 0 0 0 5 PU 0 / No 5 0 5 0 10 Yes 10 CaCl2 No 1 4 10 Yes 10 Cirtic No 1 5 11 acid Yes 11 1 / No 5 2 4 4 15 Yes 5 5 4 16 CaCl2 No 5 5 4 4 18 Yes 5 5 4 19 Cirtic No 5 5 4 19 acid Yes 5 5 4 19 2 / No 3 2 5 5 15 Yes 5 5 5 17 CaCl2 No 3 5 3 5 16 Yes 5 4 5 19 Cirtic No 3 5 4 5 17 acid Yes 5 5 20 3 / No 1 3 3 5 12 Yes 4 5 5 17 CaCl2 No 1 5 2 5 13 Yes 4 5 5 19 Cirtic No 1 5 3 5 14 acid Yes 4 5 5 19 Legend 0 Bad 5 Perfect indicates data missing or illegible when filed

[0067] From the results it can be gleaned that the higher pigment to binder ratio gives a higher dustiness, unless “dual layer” is applied. The image quality grows with higher pigment to binder ratio and the adhesion generally drops. The “dual layer” and the availability of a cationic flocculating agent like citric acid lifts the adhesion or lamination strength back up.

[0068] The best inkjet receiver coating from the results is the one having a pigment to binder ratio of 2, having been applied in two substeps (“dual layer”), in accordance with the preferred embodiment listed above, and comprising citric acid. Several other results are also well acceptable.

[0069] The present invention is in no way limited to the embodiments described herein above; on the contrary, such decorative films, floor panels or wall-to-wall floor coverings and methods for manufacturing them can be realized according to various variants, without leaving the scope of the present invention.