SET OF INK FOR INKJET PRINTING A PAPER SHEET FOR BEING USED IN THE MANUFACTURING OF DECORATIVE PANELS, A METHOD FOR PRINTING ON A PAPER SHEET, A PRINTED PAPER SHEET AND A DECORATIVE PANEL

Abstract

A set of inks is provided for inkjet printing on a paper substrate, for example a paper sheet, for being used in laminated panel, preferably a floor, a wall, or furniture panels. The inks may be pigmented inks. The set of inks may include a cyan ink, a yellow ink, at least a red ink, and at least a black ink.

Claims

1. A set of inks for inkjet printing on a paper sheet for being used in a laminated panel, the inks being pigmented inks, the set of inks comprising: a cyan ink; a yellow ink; at least a red ink; and at least a black ink.

2. The set of inks of claim 1, wherein the set of inks comprises a first red ink and a second red ink; and wherein the first red ink and the second red ink are different from each other.

3. The set of inks of claim 1, wherein the first red ink comprises at least one pigment selected from the group consisting of: C.I. pigment red 144, C.I. pigment red 254, C.I. pigment red 176, C.I. pigment red 207, C.I. pigment red 242, or a mixed crystal thereof; and/or wherein the second red ink comprises at least one pigment selected from the group consisting of: C.I. pigment red 122, C.I. pigment red 202, C.I. pigment violet 19, C.I. pigment red 32, or a mixed crystal thereof.

4. The set of inks of claim 2, wherein the first red ink comprises at least one pigment having a hue angle between 350? and 42?.

5. The set of inks of claim 2, wherein the second red ink comprises at least one pigment having a hue angle between 312? and 350?.

6. The set of inks according to claim 1, wherein the red ink comprises a pigment selected from the group consisting of: C.I. pigment red 144, C.I. pigment red 254, C.I. pigment red 176, C.I. pigment red 122, C.I. pigment red 202, C.I. pigment red 207, C.I. pigment red 242, C.I. pigment violet 19, C.I. pigment red 32, or a mixed crystal thereof.

7. The set of inks according to claim 1, wherein the yellow ink comprises a pigment selected form the group consisting of: C.I. pigment yellow 110, C.I. pigment yellow 150, C.I. pigment yellow 93, C.I. pigment yellow 139, C.I. pigment yellow 181, or a mixed crystal thereof.

8. The set of inks according to claim 1, wherein the cyan ink comprises a phtalocyanine pigment.

9. The set of inks according to claim 1, wherein the black ink comprises a carbon black pigment.

10. The set of inks according to claim 1, wherein the set of inks comprises a first black ink and a second black ink.

11. The set of inks of claim 10, wherein the second black ink comprises a pigment load lower than the first black ink.

12. The set of inks of claim 10, wherein the second black ink comprises a pigment load between 0.1 and 2% based on the total weight of the ink.

13. The set of inks according to claim 1, wherein the inks are water-based, UV based, or hydro-UV based.

14. A method for manufacturing a decor paper sheet, for being used in a laminated panel, the method comprising: providing a base paper sheet; and inkjet printing a d?cor on the paper sheet; wherein the inkjet printing is performed using the set of inks according to claim 1.

15. The method of claim 14, wherein the paper sheet shows: a base paper weight higher than 20 grams per square meter; and/or a mean air resistance as expressed in Gurley value below 40 sec.

16. The method of claim 14, wherein the decor is a wood, stone, ceramic and/or cement imitating d?cor.

17. The method according to claim 14, further comprising: applying an ink receiver layer on a surface to be printed of the paper sheet before performing the inkjet printing.

18. The method according to claim 17, wherein the paper sheet with the ink receiver layer shows a resin penetration time of lower than 3 sec.

19. The method according to claim 17, wherein the ink receiver layer comprises a binder, and a metal salt.

20. A decorative paper sheet for being used in laminated panel, wherein the decorative paper sheet comprises an inkjet printed d?cor that is manufactured in a method according to claim 14.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] With the intention of better showing the characteristics of the invention, in the following, as an example without any limitative character, several preferred forms of embodiments are described with reference to the accompanying drawings, wherein:

[0039] FIG. 1 shows in perspective a panel according to the invention;

[0040] FIG. 2 shows a view according to the line II-II indicated on FIG. 1;

[0041] FIG. 3 shows on a larger scale provide a view on the area F3 illustrated in FIG. 2;

[0042] FIG. 4 shows some steps in a method for forming the panel of FIG. 1.

DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0043] FIG. 1 illustrates a decorative panel 1 comprising a substrate 2 made of a wood based material, preferably HDF and a top layer 3 provided with a printed motif 4, in this case imitating a wood d?cor. The panel 1 can have the shape of a rectangular and oblong floor panel, with a pair of long sides 5 and a pair of short sides 6. In this case the panel 1 is provided at least at the long sides 5 with coupling means 7 allowing to lock the respective sides 5 together with the sides of a similar panel both in a direction R1 perpendicular to the plane of the coupled panels, and in a direction R2 perpendicular to the coupled sides and in the plane of the coupled panels. As illustrated in FIG. 2 such coupling means or coupling parts can basically have the shape of a tongue 8 and a groove 9, provided with additional cooperating locking means 10 allowing for said locking in the direction R2.

[0044] FIG. 2 and FIG. 3 show that the top layer 3 comprises a d?cor layer 11 and a wear layer 12 provided on top of the decor layer 11. The decor layer 11 comprises a paper sheet 13, and the digitally printed d?cor 4. The d?cor layer 11 further comprises an inkjet receiving layer 14 on the paper sheet 13. In the example the inkjet receiving layer comprises a binder and at least one cationic metal salt. The binder preferably comprises polyvinyl alcohol. The metal salt is CaCl.sub.2. The inkjet receiving layer further comprise a cross linker, and other additives like dispersant, coupling agent, wetting agent or PH modifiers. The ink receiver layer is present on the paper sheet in an amount below 5 g/sqm (grams per square meter).

[0045] In the example, the wear layer 12 is a transparent overlay paper.

[0046] FIG. 4 shows some step of a method for manufacturing the panel 1. In the method is illustrated a step S1 of providing the paper 13 by uncoiling it from a first roll 16. The paper 13 is then provided, on at least one surface, with the inkjet receiving layer 14, for example with a doctor blade, a roller coater or a sprayer, in a step S2.

[0047] The coated paper 13 is then printed (step S3) in a single pass printer 20 using pigment containing water-based inks.

[0048] After printing, the obtained decorative paper 11 is coiled again in a second roll 17 and then stocked, as indicated in step S4.

[0049] For the production of the panel 1, the decorative paper 11 can be uncoiled from second roll 17 in a step S5 and then impregnated with a thermosetting resin 15, preferably a melamine formaldehyde resin, in a step S6. The decorative sheet 11 can then be cut into sheets 18, in a step S7. The sheets 18 are then sandwiched between a support 2 and a wear layer 12 and then thermally laminated to form the panel 1.

[0050] In the examples the printed motif 4 is obtained by jetting a set of multiple inks. The set of inks comprises six inks and preferably is constituted by: cyan, yellow, a first red ink, a second red ink, a first black ink and a second black ink.

[0051] The cyan ink comprises a phtalocyanine pigment.

[0052] The yellow ink comprises a C.I. pigment yellow 150.

[0053] The first red ink comprises one warm red pigment having a hue angle between 350? and 42?, in particular C.I. pigment red 254.

[0054] The second red ink comprises one warm red pigment having a hue angle between 312? and 350?, in particular C.I. pigment red 122.

[0055] Both the first and the second black ink comprise carbon black pigment C.I. 7. The first black ink comprises pigment load between 2 and 7% by weight and the second black ink comprises a pigment load between 0.1 and 2% by weight.

[0056] Each ink of the set has a viscosity below 15 mPas at a temperature between 25 and 45? C.

[0057] Each ink of the set comprises a water content between 25 to 80% by weight; 0.1 to 3% weight of surfynol 104E as a wetting agent; a humectant in an amount of 2 to 45%, preferably 1.2 hexanediol; 0-6% by weight of Dowanol DPnP; 1-10% by weight of dispersant, 0.1-1% by weight of pH adjuster.

[0058] It is generally noted that the dimensions of the represented top layer 3 and its components is, in the figures, drawn out of scale in order to better illustrate the invention.

[0059] The invention is further disclosed by the following item list as defined by the below numbered items.

1.A set of inks for inkjet printing on paper sheet for being used in laminated panel, preferably floor, wall or furniture panels, said inks being pigmented inks, wherein said set of inks comprises: a cyan ink, a yellow ink, at least a red ink and at least a black ink.
2.The set of inks of item 1, wherein said set of inks comprises a first red ink and a second red ink wherein said first and second red ink are different each other, for example they comprise different pigments.
3.The set of inks of item 1 or 2, wherein said first red ink comprises at least one pigment selected in the group consisting of: C.I. pigment red 144, C.I. pigment red 254, C.I. pigment red 176, C.I. pigment red 207, C.I. pigment red 242 or mixed crystal thereof; and/or wherein said second red ink comprises at least one pigment selected in the group consisting of: C.I. pigment red 122, C.I. pigment red 202, C.I. pigment violet 19, C.I. pigment red 32 or a mixed crystal thereof.
4.The set of inks of item 2 or 3, wherein said first red ink comprises at least one pigment having a hue angle between 350? and 42?, for example wherein said first red ink comprises a mixture of pigments and wherein the ink has a hue angle between 350? and 42? 5.The set of inks any of items from 2 to 4, wherein said second red ink comprises at least one pigment having a hue angle between 312? and 350?, for example wherein said second red ink comprises a mixture of pigments and wherein the ink has a hue angle between 312? and 350?.
6.The set of inks according to any preceding items, wherein said red ink comprises a pigment selected in the group consisting of: C.I. pigment red 144, C.I. pigment red 254, C.I. pigment red 176, C.I. pigment red 122, C.I. pigment red 202, , C.I. pigment red 207, C.I. pigment red 242 C.I. pigment violet 19, C.I. pigment red 32 or a mixed crystal thereof.
7.The set of inks according to any preceding items, wherein said yellow ink comprises a pigment selected form selected in the group consisting of: C.I. pigment yellow 110, C.I. pigment yellow 150, C.I. pigment yellow 93, C.I. pigment yellow 139, C.I. pigment yellow 181 or a mixed crystal thereof.
8.The set of inks according to any preceding items, wherein the cyan pigment comprises a phtalocyanine pigment.
9.The set of inks according to any preceding items, wherein said black pigment comprises a carbon black pigment.
10.The set of inks according to any preceding items, wherein it comprises a first and a second black ink, preferably said second black ink having a lower color intensity than the first black ink.
11.The set of inks of item 10, wherein said second black ink comprises a pigment load lower than the first black ink, preferably said pigment load of the second black ink is at least 4, more preferably at least 5 times lower than the first black ink.
12.The set of inks of item 10 or 11, wherein said second black ink comprises a pigment load comprised between 0.1 and 2% based on the total weight of the ink.
13.The set of inks to any preceding items, wherein said inks are water-based, UV based or hydro-UV based.
14.A method for manufacturing a decor paper sheet, for being used in laminated panel, preferably floor, wall or furniture panels, comprising the step of providing a base paper sheet and the step of inkjet printing a d?cor on said paper sheet, wherein said step of inkjet printing is performed using the set of inks according to any preceding items.
15.The method of item 14, wherein the paper sheet shows: [0060] a base paper weight higher than 20 grams per square meter, preferably between 50 to 100 grams per square meter, e.g. between 60 and 80 grams per square meter; and/or [0061] a mean air resistance as expressed in Gurley value below 40 sec, preferably below 25 sec.
16.The method of item 14 or 15, wherein said d?cor is a wood, stone, ceramic and/or cement imitating d?cor.
17.The method according to any of items from 14 to 16, wherein said method comprises the step of applying an ink receiver layer on the surface to be printed of paper sheet before performing said inkjet printing.
18.The method according to item 17, wherein the paper sheet comprising the ink receiver layer shows a resin penetration time lower than 3 sec.
19.The method according to item 17 or 18, wherein the ink receiver layer comprises at least a binder, preferably polyvinyl alcohol, and a metal salt, preferably a cationic metal salt.
20.A decorative paper sheet for being used in laminated panel, preferably floor, wall or furniture panels, wherein said decorative paper sheet comprises an inkjet printed d?cor that is manufactured in a method according to any of items from 14 to 19.
21.A method for manufacturing a decorative panel, preferably floor, wall or furniture panels, comprising a substrate, and a top layer, said top layer comprising a d?cor layer, wherein said d?cor layer is printed using the set of inks according to any of the times from 1 to 13, preferably said top layer further comprises a wear layer.