DECOR PAPER FOR LAMINATES

Abstract

Decoration paper for a decorative laminate, which is inkjet printable, comprising a paper substrate comprising at least one opacifying pigment having a refractive index of greater than 2, and on at least one face of the substrate a surface treatment comprising a binder and between 0.5 and 9 g/m.sup.2 of a filler having a specific surface area of between 2 and 100 m2/g and a refractive index of less than or equal to 2.

Claims

1. Decor paper for decorative laminates printable by inkjet, comprising a paper substrate with at least an opacifier pigment of refractive index greater than 2, and on at least one side of the substrate, a surface treatment comprising a binder and between 0.5 and 9 g/m.sup.2 of a filler with specific surface area from 2 to 100 m.sup.2/g and refractive index equal to or less than 2.

2. Paper according to claim 1, with specific surface area of the filler from 2 50 m.sup.2/g, in particular 10 to 30 m.sup.2/g.

3. Paper according to claim 1 with a resin penetration time on at least the side having received the surface treatment equal to or less than 10 s, or better equal to or less than 5 s.

4. Paper according to claim 3, the paper having a resin penetration time on each of its sides equal to or less than 10 s, or better equal to or less than 5 s.

5. Paper according to claim 1 wherein the binder represents between 10 and 50% in dry weight of the surface treatment.

6. Paper according to claim 1 wherein the filler represents between 50 and 90% in dry weight of the surface treatment.

7. Paper according to claim 1 wherein the surface treatment is deposited at a rate from 1 to 10 g/m.sup.2 in dry weight per treated side, in particular 3 to 6 g/m.sup.2 per treated side, or 4 to 5 g/m.sup.2.

8. Paper according to claim 1 wherein the binder is water-soluble.

9. Paper according to claim 1 wherein the binder contains PVOH, or better is composed of PVOH.

10. Paper according to claim 1 wherein the surface treatment is without silica.

11. Paper according to claim 1 wherein the surface treatment contains silica, in particular in a proportion equal to or less than 50% in mass of the said filler, or better between 5 and 30% in mass of the said filler.

12. Paper according to claim 1 wherein the filler contains at least one compound chosen from among clays, calcined clays, kaolins (natural, calcined, delaminated, and other silicates of aluminium, in particular synthetic), talc, diatomaceous earths, aluminium trihydrate, and mixtures of these.

13. Paper according to claim 1 wherein the surface treatment contains a salt of an alkaline earth metal, in particular CaCl.sub.2.

14. Paper according to claim 1 wherein the surface treatment contains at least one cationic polymer, in particular polyDADMAC.

15. Paper according to claim 1 wherein the opacifier pigment contains TiO.sub.2 or is composed of TiO.sub.2.

16. Paper according to claim 1 wherein the quantity of opacifier pigment in the paper substrate, in particular TiO.sub.2, is equal to or greater than 10% of the total dry weight of the paper in g/m.sup.2, more preferably is equal to or greater than 20%, or still better to 25%.

17. Paper according to claim 1 wherein only one side of the paper substrate has received the surface treatment.

18. Paper according to claim 1 wherein the quantity of filler is between 2 and 4 g/m.sup.2 per treated side.

19. Paper according to claim 1 wherein the filler to binder ratio is greater than 3:1, in particular 3.5:1 in dry weight.

20. Printed decor paper, comprising a decor paper according to claim 1 and an inkjet print.

21. Decor paper manufacturing process, in particular according to claim 1, comprising the step consisting in applying to at least one side of a paper substrate at least one composition comprising a binder and a filler with specific surface area between 2 and 100 m.sup.2/g and refractive index equal to or less than 2, in a quantity such that between 0.5 and 9 g/m.sup.2 of filler in dry weight is deposited on the paper.

22. Process according to the preceding claim wherein the composition is applied by a film transfer system.

23. High, low or continuous pressure laminate, comprising a decor paper as defined according to claim 1, or obtained by a process as defined in claim 21.

Description

EXAMPLES

[0147] A decor paper is first produced on a paper machine, the paper composed in particular of 100% short eucalyptus cellulose fibres, of TiO.sub.2 for a proportion of 35% in the paper substrate, small quantities of pigment providing a shade to aim for a defined colour and various chemical agents, in particular a wet strength agent.

[0148] The manufacture of this paper follows the traditional paper process known to experts in the field, namely pulping of the paper, refining, addition of components (TiO.sub.2, coloured pigments, additives), dilution then formation of the sheet, pressing and drying before arriving at the coating station which is always located on the paper machine.

[0149] The various formulations described in examples 1 to 15 in the tables corresponding to FIGS. 1 and 2 in the appended drawing are then applied to the paper. In examples 1 to 14, the coating station is a size press, a widely used paper process. In example 15, coating is done manually on one side of the substrate with a grooved rod to simulate coating (Meyer bar, knife coating layer, etc.) or film transfer (film press). The concentrations and formulations are adapted so as to obtain dry deposits with the values given in the table of FIG. 1. In the examples according to the invention given in FIG. 1 (except for example 15), the final paper weight obtained is between 75 et 80 g/m.sup.2 but could be adjusted by changing the paper weight of the substrate. Example 15 has the lowest paper weight, because of the lesser quantity of deposit applied to a single side of the substrate, but this too could be adjusted by changing the paper weight of the substrate.

[0150] The results firstly show the pronounced effect of the silica-based formulation (called silica A in the example), which decreases the air permeability of the paper (the higher the Gurley index, the lower the permeability). Thus, even with only 5 g/m.sup.2 from the formula given in example 1, the paper already has a Gurley value of 35 seconds while in example 4 according to the invention, the Gurley value is only 23 seconds for a deposit of 9.4 g/m.sup.2. If the comparison is made between close deposition of 9.5 g/m.sup.2 in example 3 and 9.4 g/m.sup.2 in example 4, the difference is still more marked, with respectively 56 seconds vs 23 seconds.

[0151] The recto/verso penetration times of the resin are still more clearly affected: 23/15 seconds in example 1, 49/52 seconds in example 3 compared with 3/2 seconds in example 4.

[0152] The advantage of the invention can be seen very clearly in the optical density values since that of the paper in example 4 is 1.61 compared with 1.51 in example 3.

[0153] The same conclusions can be drawn for the optical densities of the papers after lamination.

[0154] The treatment of the invention thus enables an extremely useful compromise to be found between optical density and resin penetration time, reflecting the impregnability.

[0155] The other examples produced by adding a cationic product to formula 1 according to the invention (PolyDADMAC or CaCl.sub.2) show synergy in the optical density without altering the resin penetration time.

[0156] The word between is understood as inclusive of limits unless otherwise stated.