LAMINABLE INK

Description

[0001] The present invention relates to a laminatable ink, the use of a laminatable ink, a decorative panel comprising a decorative layer made of laminatable ink and a method for producing a decorative panel comprising a decorative layer made of laminatable ink.

[0002] Decorative surfaces have a wide range of applications to create an appealing and personalized appearance. Surfaces are often decorated using various printing processes. Inks are transferred to a surface in the desired pattern and then fixed to form a decorative layer. In many areas, the use of radiation-curing inks has proven effective, as these can be cured using radiation, such as UV or electron beams, shortly after transfer to the surface to be printed, preventing them from running and allowing decorative layers with particularly sharp patterns to be created. These types of inks are particularly useful when printing on non-absorbent substrates.

[0003] Inkjet printing is frequently used, especially in the production of customized decorative surfaces. In this process, ink is transferred to the surface to be printed via computer-controlled nozzles based on a template. Radiation-curing inks can be fixed with radiation in the usual way after inkjet printing.

[0004] Increasingly, functional surfaces are also being provided with surface decorations. For example, wall, ceiling, and floor panels with decorations have a functional surface.

[0005] Decorated panels are known per se, although the term "wall panel" also includes panels suitable for ceiling or door cladding. They typically consist of a carrier or core made of a solid material, for example, a wood-based material such as medium-density fiberboard (MDF) or high-density fiberboard (HDF), a wood-plastic composite (WPC), or a mineral-plastic composite (MPC), which is provided on at least one side with a decorative layer and a cover layer, as well as optionally with further layers, for example, a wear layer arranged between the decorative and cover layers. In the case of MDF or HDF carriers, the decorative layer is usually applied to a printing substrate arranged on the carrier, which can be formed, for example, from a paper layer.It is known to print the decorative layer onto the paper layer before applying the paper layer to the substrate, or to apply an initially unprinted paper layer to the substrate and then apply the decorative layer to the paper layer using a so-called direct printing process. In the case of substrates based on plastic composite materials, it is known to apply a decoration using a direct printing process after applying a printing substrate, if necessary.

[0006] Such decorated surfaces must usually meet high requirements regarding mechanical abrasion, dirt resistance, impact resistance, and the like. Therefore, a sealing or covering layer is often applied to a decorated surface. Often, such wear-resistant or covering layers incorporate a surface structure imitating a decorative template, so that the surface of the decorative panel has a tactile structure whose shape and pattern are adapted to the applied decoration, thus achieving the most faithful reproduction of a natural material, including its haptic quality.

[0007] Sealing or covering layers are often applied under pressure and temperature. Such processes are also called lamination.

[0008] It is important that the additional layers applied to the decorative layer adhere well to the decorative layer, or, if possible, form a bond with sufficient bond strength, in particular with sufficient physical or chemical bond strength. Radiation-curing inks for decorating substrates are known, for example, from WO 2013 / 019821 or EP 2842763.

[0009] There is therefore a need to provide radiation-curing inks that can be easily bonded to additional layers after radiation curing. A disadvantage of existing radiation-curing inks is that they no longer bond well to additional layers after curing. Accordingly, existing radiation-curing inks are difficult to laminate. To date, bonding has usually been achieved by applying an adhesive to the decorative layer. However, this requires at least one additional process step.

[0010] It is therefore the object of the present invention to provide an improved laminatable ink.

[0011] This object is achieved by laminatable inks according to claim 1 and further by a use of such laminatable inks according to claim 13, panels having a decorative layer of laminatable ink according to claim 14 and a method for producing such panels according to claim 15. Preferred embodiments of the invention are specified in the subclaims, in the description or the examples, wherein further features described or shown in the subclaims or in the description or the examples can individually or in any combination constitute an object of the invention, unless the context clearly indicates the opposite.

[0012] The invention proposes a laminatable ink comprising a radiation-curable ink, preferably in an amount, based on the laminatable ink, of ≥ 50 wt.% to ≤ 99 wt.%, preferably ≥ 70 wt.% to ≤ 95 wt.%, particularly preferably ≥ 80 wt.% to ≤ 90 wt.%, and a thermally activatable matrix material, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 50 wt.%, preferably ≥ 5 wt.% to ≤ 30 wt.%, particularly preferably ≥ 10 wt.% to ≤ 20 wt.%, wherein the matrix material comprises at least one thermally activatable polymer, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 30 wt.%, preferably >_ 5 wt.% to ≤ 20 wt.%, particularly preferably ≥ 10 wt% to ≤ 15 wt%.

[0013] It was surprisingly shown that a decorative layer can be produced with such a laminatable ink, in particular by means of inkjet printing, the laminatable ink is furthermore radiation-curable and can be laminated after radiation curing, whereby a good bond strength with the laminate can be obtained without additionally applying an adhesive to the decorative layer before lamination.

[0014] For the purposes of the present invention, a radiation-curable ink is understood to mean inks, i.e. coloring liquids, which react and solidify at least partially when induced by electromagnetic radiation of a suitable wavelength, such as UV radiation, or electron radiation.

[0015] For the purposes of the present invention, a thermally activatable polymer is understood to be a polymer that softens or liquefies under the influence of temperature and can further polymerize or crosslink, particularly after radiation curing. In a preferred embodiment of the invention, the radiation-curable ink can comprise a monomer, an oligomer, a photoinitiator, a stabilizer, a dispersant, and / or a dye.

[0016] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a monomer, preferably in an amount, based on the laminatable ink, of ≥ 25 wt.% to ≤ 60 wt.%, particularly preferably of ≥ 30 wt.% to ≤ 50 wt.%.

[0017] For the purposes of the present invention, a monomer is understood to be an organic molecule that, initiated by photoinitiators, enters a polymerization reaction and forms polymers. Monomers primarily serve as diluents to make the laminatable ink printable and, during polymerization, serve in particular to cure and crosslink the ink. In this respect, monomers for the purposes of this invention can be reactive diluents, which influence the viscosity of the ink composition and themselves crosslink to form corresponding polymers in a photoinitiated polymerization reaction.

[0018] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises an oligomer, preferably in an amount, based on the laminatable ink, of ≥ 5 wt.% to ≤ 50 wt.%, preferably ≥ 8 wt.% to ≤ 40 wt.%, particularly preferably ≥ 10 wt.% to ≤ 20 wt.%.

[0019] For the purposes of the present invention, an oligomer is understood to be a polymer with a low molecular weight and a small number of repeating units. Oligomers serve to adhere to the surface to be printed and, during polymerization, also to cure and crosslink.

[0020] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a photoinitiator, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 10 wt.%, preferably ≥ 3 wt.% to ≤ 8 wt.%, particularly preferably ≥ 4 wt.% to ≤ 6 wt.%.

[0021] For the purposes of the present invention, a photoinitiator is understood to mean compounds which react upon absorption of electromagnetic radiation, in particular upon absorption of light, such as UV light, and form a reactive compound which can initiate a polymerization reaction.

[0022] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a stabilizer, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably of ≥ 1.5 wt.% to ≤ 2.5 wt.%.

[0023] For the purposes of the present invention, a stabilizer is understood to mean compounds that improve the stability of a composition.

[0024] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a dispersant, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably of ≥ 1.5 wt.% to ≤ 2.5 wt.%.

[0025] For the purposes of the present invention, a dispersant refers to compounds that stabilize dispersions. Dispersants, for example, absorb onto the surface of particles to be dispersed, thus preventing particle agglomeration.

[0026] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a dye, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 60 wt.%, preferably ≥ 10 wt.% to ≤ 50 wt.%, particularly preferably ≥ 20 wt.% to ≤ 40 wt.%.

[0027] For the purposes of the present invention, a dye is understood to mean compounds which have a characteristic colour.

[0028] In a preferred embodiment of the invention, it can be provided that the radiation-curable ink contains a monomer in an amount of ≥ 25 wt.% to ≤ 60 wt.%, particularly preferably from ≥ 30 wt.% to ≤ 50 wt.%, an oligomer in an amount of ≥ 5 wt.% to ≤ 50 wt.%, preferably ≥ 8 wt.% to ≤ 40 wt.%, particularly preferably from ≥ 10 wt.% to ≤ 20 wt.%, a photoinitiator in an amount of ≥ 1 wt.% to ≤ 10 wt.%, preferably ≥ 3 wt.% to ≤ 8 wt.%, particularly preferably from ≥ 4 wt.% to ≤ 6 wt.%, a stabilizer in an amount of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 Wt.% to ≤ 2.5 wt.%, a dispersant in an amount of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 wt.% to ≤ 2.5 wt.% and a dye in an amount of ≥ 1 wt.% to ≤ 60 wt.%, preferably ≥ 10 wt.% to ≤ 50 wt.%, particularly preferably from ≥ 20 wt.% to ≤ 40 wt.%, based on the laminatable ink.

[0029] This advantageously ensures that the laminatable ink is readily radiation-curable, stable, has good color properties, and does not adversely affect laminatability.

[0030] In a preferred embodiment of the invention, it can be provided that the thermally activatable matrix material comprises a macromer, preferably in an amount, based on the laminatable ink, of ≥ 1 wt.% to ≤ 10 wt.%, particularly preferably of ≥ 2 wt.% to ≤ 5 wt.%.

[0031] For the purposes of the present invention, a macromer refers to macromolecular compounds that have a reactive end group and are thus polymerizable. Macromers, for example, modify the surface free energy of coatings and aid adhesion.

[0032] In a preferred embodiment of the invention, it can be provided that the thermally activatable matrix material comprises a solvent, preferably in an amount, based on the laminatable ink, of ≥ 0 wt.% to ≤ 5 wt.%, preferably ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably ≥ 1.5 wt.% to ≤ 2.5 wt.%.

[0033] For the purposes of the present invention, a solvent is understood to mean liquids that dissolve the polymer.

[0034] In a preferred embodiment of the invention, it can be provided that the thermally activatable matrix material comprises a macromer in an amount of ≥ 1 wt.% to ≤ 10 wt.%, particularly preferably from ≥ 2 wt.% to ≤ 5 wt.% and optionally a solvent in an amount of ≥ 0 wt.% to ≤ 5 wt.%, preferably ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 wt.% to ≤ 2.5 wt.%, based on the laminatable ink.

[0035] This advantageously ensures that the laminatable ink has good laminability without adversely affecting the radiation curability, stability and color properties.

[0036] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink contains a monomer in an amount of ≥ 25 wt.% to ≤ 60 wt.%, particularly preferably from ≥ 30 wt.% to ≤ 50 wt.%, an oligomer in an amount of ≥ 5 wt.% to ≤ 50 wt.%, preferably ≥ 8 wt.% to ≤ 40 wt.%, particularly preferably from ≥ 10 wt.% to ≤ 20 wt.%, a photoinitiator in an amount of ≥ 1 wt.% to ≤ 10 wt.%, preferably ≥ 3 wt.% to ≤ 8 wt.%, particularly preferably from ≥ 4 wt.% to ≤ 6 wt.%, a stabilizer in an amount of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 wt.% to ≤ 2.5 wt.%, a dispersant in an amount of ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 wt.% to ≤ 2.5 wt.%, and a dye in an amount of ≥ 1 wt.% to ≤ 60 wt.%, preferably ≥ 10 wt.% to ≤ 50 wt.%, particularly preferably from ≥ 20 wt.% to ≤ 40 wt.-%, based on the laminatable ink, and the thermally activatable matrix material comprises a macromer in an amount of ≥ 1 wt.% to ≤ 10 wt.%, particularly preferably from ≥ 2 wt.% to ≤ 5 wt.% and optionally a solvent in an amount of ≥ 0 wt.% to ≤ 5 wt.%, preferably ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably from ≥ 1.5 wt.% to ≤ 2.5 wt.%, based on the laminatable ink.

[0037] This advantageously ensures that the laminatable ink has particularly good laminability, radiation curability, stability and color properties.

[0038] In a preferred embodiment of the invention, it can be provided that the monomer is an acrylate monomer.

[0039] This advantageously ensures that the laminatable ink can be particularly well radiation cured.

[0040] In a preferred embodiment of the invention, it can be provided that the monomer is selected from the group consisting of monofunctional monomers, difunctional monomers, multifunctional monomers or mixtures thereof.

[0041] The different monomers allow the curing properties of the laminatable ink to be advantageously adjusted. In particular, the molecular weight of the cured ink can be adjusted.

[0042] In a preferred embodiment of the invention, it can be provided that the monomer comprises a monofunctional monomer selected from the group consisting of isobornyl acrylate, glycidyl methacrylate and mixtures thereof.

[0043] The monofunctional monomers described above can advantageously ensure that the laminatable ink is particularly easy to cure.

[0044] In a preferred embodiment of the invention, it can be provided that the monomer comprises a difunctional monomer selected from the group consisting of 1,3-glycerol dimethacrylate, 1,10-decanediol dimethacrylate, tricyclodecane dimethanol diacrylate, 1,9-nonanediol dimethacrylate and mixtures thereof.

[0045] This advantageously ensures that the monomer forms additional cross-links during curing, whereby a particularly good stability of a decorative layer can be achieved.

[0046] In a preferred embodiment of the invention, it can be provided that the monomer comprises a multifunctional monomer.

[0047] This also advantageously allows the monomer to form additional cross-links during curing, which can result in particularly good stability of a decorative layer.

[0048] The multifunctional monomer is trimethylolpropane triacrylate.

[0049] In an alternative particularly preferred embodiment of the invention, it can be provided that the monomer is a mixture of isobornyl acrylate and glycidyl methacrylate.

[0050] Surprisingly, it was shown that trimethylolpropane triacrylate or a mixture of isobornyl acrylate and glycidyl methacrylate is particularly suitable as a monomer, since this advantageously allows the laminatable ink to be particularly well radiation-cured and, at the same time, particularly well laminated.

[0051] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises trimethylolpropane triacrylate in an amount of ≥ 20 wt.% to ≤ 70 wt.%, preferably of ≥ 35 wt.% to ≤ 50 wt.%, particularly preferably of ≥ 40 wt.% to ≤ 45 wt.% as monomer, based on the laminatable ink.

[0052] In an alternative particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises a mixture of isobornyl acrylate and glycidyl methacrylate in an amount of ≥ 20 wt.% to ≤ 70 wt.%, preferably of ≥ 25 wt.% to ≤ 50 wt.%, particularly preferably of ≥ 30 wt.% to ≤ 40 wt.% as monomer, based on the laminatable ink.

[0053] It was surprisingly shown that particularly good radiation curing can be advantageously achieved by using these amounts of trimethylolpropane triacrylate or a mixture of isobornyl acrylate and glycidyl methacrylate.

[0054] In a preferred embodiment of the invention, it can be provided that the oligomer is an acrylate cooligomer.

[0055] This advantageously ensures that the laminatable ink can be particularly well radiation cured.

[0056] In a preferred embodiment of the invention, it can be provided that the oligomer is selected from the group consisting of acrylic acrylate, urethane acrylate, melamine acrylate, epoxy acrylate, polyester acrylate and mixtures thereof.

[0057] In a particularly preferred embodiment of the invention, it can be provided that the oligomer is urethane acrylate.

[0058] In an alternative particularly preferred embodiment of the invention, it can be provided that the oligomer is melamine acrylate.

[0059] It was surprisingly shown that urethane acrylate or melamine acrylate is particularly suitable as an oligomer, since this advantageously allows the laminatable ink to be particularly well radiation-cured and, at the same time, particularly well laminated.

[0060] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises urethane acrylate in an amount of ≥ 5 wt.% to ≤ 50 wt.%, preferably ≥ 8 wt.% to ≤ 20 wt.%, particularly preferably ≥ 10 wt.% to ≤ 15 wt.%, as oligomer, based on the laminatable ink.

[0061] In an alternative particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises melamine acrylate in an amount of ≥ 5 wt.% to ≤ 50 wt.%, preferably >_ 8 wt.% to ≤ 20 wt.%, particularly preferably ≥ 10 wt.% to ≤ 15 wt.%, as oligomer, based on the laminatable ink.

[0062] It was surprisingly shown that particularly good radiation curing can be achieved advantageously by using these amounts of urethane acrylate or melamine acrylate.

[0063] In a preferred embodiment of the invention, it can be provided that the oligomer has a molecular weight in a range of ≥ 500 g / mol to ≤ 5000 g / mol.

[0064] In a preferred embodiment of the invention, it can be provided that the photoinitiator is selected from the group consisting of benzophenone, alpha ketone, thiophenylmorpholinepropanone, thioxanthone and mixtures thereof.

[0065] This advantageously makes it possible to initiate curing by radiation of a corresponding wavelength range, for example by UV radiation.

[0066] In a particularly preferred embodiment of the invention, it can be provided that the photoinitiator is alpha ketone.

[0067] In an alternative particularly preferred embodiment of the invention, it can be provided that the photoinitiator is thiophenylmorpholinopropanone.

[0068] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises alpha ketone in an amount of ≥ 1 wt.% to ≤ 10 wt.%, preferably ≥ 3 wt.% to ≤ 8 wt.%, particularly preferably ≥ 4 wt.% to ≤ 6 wt.%, as photoinitiator, based on the laminatable ink.

[0069] In an alternative particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises thiophenylmorpholinopropanone in an amount of ≥ 1 wt.% to ≤ 10 wt.%, preferably ≥ 3 wt.% to ≤ 8 wt.%, particularly preferably ≥ 4 wt.% to ≤ 5 wt.%, as photoinitiator, based on the laminatable ink.

[0070] In a preferred embodiment of the invention, it can be provided that the dispersant is selected from the group consisting of Efka 4000, Efka 5000, Efka 6000, Dispex, ultradisperse, RAD-SPERSE and mixtures thereof.

[0071] This advantageously ensures that the color of the laminatable ink is uniform without negatively affecting the laminability or radiation curability.

[0072] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink RAD-SPERSE in an amount of ≥ 0 wt.% to ≤ 5 wt.%, preferably ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably ≥ 1.5 wt.% to ≤ 2.5 wt.%, as dispersant, based on the laminatable ink.

[0073] In a preferred embodiment of the invention, it can be provided that the stabilizer is selected from the group consisting of 2-hydroxy-4-octyloxybenzophenone, 2-(2-hydroxy-5-methylphenyl) benzotriazole, 2,2-dihydroxy-4,4-dimethoxybenzophenone and mixtures thereof.

[0074] This advantageously ensures that the laminatable ink is heat-stable.

[0075] In a particularly preferred embodiment of the invention, it can be provided that the radiation-curable ink comprises 2-hydroxy-4-octyloxybenzophenone in an amount of ≥ 0 wt.% to ≤ 5 wt.%, preferably ≥ 1 wt.% to ≤ 3 wt.%, particularly preferably ≥ 1.5 wt.% to ≤ 2.5 wt.%, as a dispersant, based on the laminatable ink.

[0076] This advantageously ensures that the laminatable ink is heat-stable and that the radiation curability and laminability of the ink are not impaired.

[0077] According to a further embodiment of the invention, the laminatable ink may contain an inhibitor. This inhibitor may preferably be present in the laminatable ink in an amount of ≥ 0 wt.% to ≤ 2 wt.%, preferably ≥ 0.005 wt.% to ≤ 1 wt.%, particularly preferably ≥ 0.01 wt.% to ≤ 0.1 wt.%.

[0078] According to a further embodiment of the invention, the inhibitor may be at least one compound selected from a group consisting of hydroquinone, methoxymethylhydroquinone, p-benzoquinone, p-methoxyquinone, phenothiazine, mono-tert-butylhydroquinone, 1,2-dihydroxybenzene, p-tert-butylcatechol, benzoquinone, 2,5-di-tert-butylhydroquinone, 2,5-p-dimethyl-p-benzoquinone, anthraquinone, 2,6-di-tert-butylhydroxytoluene, and organic phosphites.

[0079] The provision of appropriate inhibitors can advantageously reduce exothermic decomposition of the laminatable ink and serve to control the photoinitiated polymerization.

[0080] In a preferred embodiment of the invention, it can be provided that the dye is an organic and / or inorganic pigment.

[0081] In a preferred embodiment of the invention, it can be provided that the dye is selected from the group, designated according to the Colour Index, consisting of NB1, NB2, PB1, PB1:2, PB15:1, NBr3, NBr7, NBr9, PBr1, NY2, NY3, NY6, NY10, NY11, NY12, NY13, NY14, PY1, PY2, PY3, PY4, PY5, PY6, NG1, NG2, PG1, PG2, PG4, PG13, NO2, NO4, NO5, NO6, PO17, PO20, NR1, NR2, NR11, NR23, NV1, PV1, PV1:1, PV1:3, PV3:3, NBK3, NBK6, NBK9, PBK11 and mixtures thereof.

[0082] This advantageously allows the color of the dye to be adjusted as desired without, in particular, impairing the radiation curability and laminability.

[0083] In a preferred embodiment of the invention, it can be provided that the dye has an average particle size of less than or equal to 200 nm, preferably less than or equal to 100 nm.

[0084] For the purposes of the present invention, the mean particle size is understood to mean the volumetrically averaged mean particle diameter D 50 , measured by laser diffractometry.

[0085] This advantageously ensures that the ink has a uniform color and can be printed well with inkjet printers. In particular, it can prevent clogging of the print nozzles.

[0086] In a preferred embodiment of the invention, it can be provided that the polymer is a UV-stable polymer.

[0087] This ensures that the thermally activatable matrix material is not affected by radiation curing using UV radiation.

[0088] In a preferred embodiment of the invention, it can be provided that the polymer is selected from the group consisting of polymethyl methacrylate, copolyacrylate, thermoplastic polyurethane, copolyamide, copolyester, liquid polybutadiene, rosin-modified polyisobutene and mixtures thereof.

[0089] It was surprisingly shown that these polymers are particularly suitable as polymers.

[0090] In a preferred embodiment of the invention, it can be provided that the polymer has a number average molecular weight in a range from ≥ 700 g / mol to ≤ 20000 g / mol.

[0091] In a preferred embodiment of the invention, it can be provided that the polymer comprises polymethyl methacrylate with a number average molecular weight in a range of ≥ 700 g / mol to ≤ 15000 g / mol.

[0092] In a preferred embodiment of the invention, it can be provided that the polymer comprises thermoplastic polyurethane with a number average molecular weight in a range of ≥ 1500 g / mol to ≤ 20000 g / mol.

[0093] In a preferred embodiment of the invention, it can be provided that the polymer comprises copolyamide with a number average molecular weight in a range of ≥ 2000 g / mol to ≤ 18000 g / mol.

[0094] In a preferred embodiment of the invention, it can be provided that the polymer comprises copolyesters with a number average molecular weight in a range of ≥ 3000 g / mol to ≤ 20000 g / mol.

[0095] In a preferred embodiment of the invention, it can be provided that the polymer comprises liquid polybutadiene with a number average molecular weight in a range of ≥ 1000 g / mol to ≤ 3000 g / mol.

[0096] The polymers described above can advantageously ensure that the matrix material is activated during lamination, and the decorative layer forms a stable bond with a laminated cover layer, exhibiting good bond strength. In particular, the polymers described above can ensure that the physical properties of the laminatable ink are not overly impaired, thus maintaining good printability and radiation curability.

[0097] In a preferred embodiment of the invention, it can be provided that the polymer has an average particle size of less than or equal to 500 µm, preferably less than or equal to 80 µm, particularly preferably less than or equal to 1 µm.

[0098] This advantageously ensures that the polymer can be well distributed in the laminatable ink, so that the laminatability is consistently good across the entire printing area.

[0099] In a preferred embodiment of the invention, it can be provided that the polymer comprises polymethyl methacrylate with an average particle size of less than or equal to 150 µm.

[0100] In a preferred embodiment of the invention, it can be provided that the polymer comprises thermoplastic polyurethane with an average particle size of less than or equal to 170 µm, in particular less than or equal to 2 µm.

[0101] In a preferred embodiment of the invention, it can be provided that the polymer comprises copolyester and / or copolyamide with an average particle size of less than or equal to 400 µm, in particular less than or equal to 1 µm.

[0102] Surprisingly, it was shown that the previously described areas are particularly well suited for the specific polymers.

[0103] In a preferred embodiment of the invention, it can be provided that the polymer comprises polymethyl methacrylate with a melting range in a range of ≥ 170 °C to ≤ 210 °C.

[0104] In a preferred embodiment of the invention, it can be provided that the polymer comprises thermoplastic polyurethane with a melting range in a range of ≥ 105 °C to ≤ 132 °C.

[0105] In a preferred embodiment of the invention, it can be provided that the polymer comprises copolyamide with a melting range in a range of ≥ 118 °C to ≤ 128 °C.

[0106] In a preferred embodiment of the invention, it can be provided that the polymer comprises copolyesters with a melting range in a range of ≥ 110 °C to ≤ 120 °C.

[0107] In a preferred embodiment of the invention, it can be provided that the polymer is a copolyacrylate and / or a liquid polybutadiene.

[0108] In a particularly preferred embodiment of the invention, it can be provided that the polymer is a copolyacrylate having a viscosity in a range of greater than or equal to 300 mPa s to less than or equal to 500 mPa s, measured according to EN ISO 3219.

[0109] In a particularly preferred embodiment of the invention, it can be provided that the polymer is a liquid polybutadiene having a viscosity in a range of greater than or equal to 200 mPa s to less than or equal to 450 mPa s, measured according to EN ISO 3219.

[0110] This advantageously ensures that the corresponding polymer produces good thermal activation of the matrix material and at the same time has a viscosity that allows good printability of the laminatable ink.

[0111] In a preferred embodiment, it can be provided that the polymer is laminated in a temperature range of greater than or equal to 100 °C to less than or equal to 130 °C.

[0112] In a preferred embodiment of the invention, the polymer can be selected from tackifiers. For example, the polymer can preferably be a rosin ester resin, in particular a rosin ester-modified polyisobutene.

[0113] In a particularly preferred embodiment of the invention, it can be provided that the matrix material comprises polymethyl methacrylate with a number average molecular weight in a range from ≥ 700 g / mol to ≤ 15000 g / mol and a melting range in a range from ≥ 170 °C to ≤ 210 °C.

[0114] In a preferred embodiment of the invention, it can be provided that the matrix material comprises thermoplastic polyurethane with a number average molecular weight in a range from ≥ 1500 g / mol to ≤ 20000 g / mol and a melting range in a range from ≥ 105 °C to ≤ 132 °C.

[0115] In a preferred embodiment of the invention, it can be provided that the macromer is selected from the group consisting of polyoxyethylenechlorotriazine, polyoxypropylenechlorotriazine, polyethylene glycol, polyether, polystyrene butylacrylate and mixtures thereof.

[0116] In a preferred embodiment of the invention, it can be provided that the macromer has a molecular weight in a range of ≥ 150 g / mol to ≤ 400 g / mol.

[0117] In a preferred embodiment of the invention, it can be provided that the macromer is polyethylene glycol.

[0118] In an alternative preferred embodiment of the invention, it can be provided that the macromer is polyether.

[0119] In a particularly preferred embodiment of the invention, it can be provided that the macromer is polyethylene glycol and the polymer is thermoplastic polyurethane.

[0120] In an alternative particularly preferred embodiment of the invention, it can be provided that the macromer is polyether and the polymer is polymethylene methacrylate.

[0121] In an alternative embodiment of the invention, it can be provided that the matrix material does not contain a macromer and the polymer is liquid polybutadiene.

[0122] The above-described embodiments advantageously ensure that the laminatable ink can form a particularly strong bond with a cover layer.

[0123] In a preferred embodiment of the invention, it can be provided that the solvent is selected from the group consisting of cyclohexanone, butanone, methyl ethyl ketone, xylene, ethyl acetate, ethyl lactate, dimethyl sulfoxide, dimethylformamide, formic acid and mixtures thereof.

[0124] This advantageously ensures that the polymer is particularly well dispersed or even dissolved in the laminatable ink. This allows for a particularly homogeneous distribution of the polymer.

[0125] The invention further proposes the use of a previously described laminatable ink for producing a decorative layer.

[0126] In one embodiment of the invention, the laminatable ink is used to produce a laminated decorative layer of a decorative panel.

[0127] By the use according to the invention it can be achieved that surfaces can be provided with a decoration and a protective layer can be applied directly to the decoration.

[0128] The invention further proposes a decorative panel comprising a decorative layer with a decoration made from a previously described laminatable ink.

[0129] The decorative panels according to the invention make it possible to realize particularly detailed decorative surfaces, wherein the decorative surfaces can be protected by at least one protective layer.

[0130] The invention further proposes a method for producing a decorative panel comprising a decorative layer with a decoration made from a previously described laminatable ink.

[0131] The procedure comprises at least the following steps: a. Providing a plate-shaped carrier, b. Printing a decoration with a previously described laminatable ink on at least a portion of the plate-shaped carrier, c. Curing the decoration with electromagnetic radiation, preferably with UV radiation, d. Laminating at least a portion of the decoration with a wear and / or cover layer, When the decoration is laminated, the cured ink is thermally activated and forms a bond with the laminate.

[0132] A "carrier" can be understood, in particular, as a layer serving as the core or base layer in a finished panel, which can, in particular, comprise a natural material such as a wood-based material, a fiber material, or a material comprising a plastic. For example, the carrier can already provide the panel with suitable stability or contribute to it.

[0133] Wood-based materials within the meaning of the invention include, in addition to solid wood materials, materials such as cross-laminated timber, glued laminated timber, block laminated timber, veneer plywood, laminated veneer lumber, strip veneer lumber and bending plywood. In addition, wood-based materials within the meaning of the invention also include wood particle materials such as chipboard, extruded boards, oriented structural boards (OSB) and strip veneer lumber as well as wood fiber materials such as wood fiber insulation boards (HFD), medium-hard and hard fiberboards (MB, HFH), and in particular medium-density fiberboards (MDF) and high-density fiberboards (HDF). Modern wood-based materials such as wood-polymer materials (wood-plastic composite, WPC), sandwich panels made of a lightweight core material such as foam, rigid foam or paper honeycomb and a wood layer applied to it, as well as mineral-bonded chipboards, e.g. with cement, also constitute wood-based materials within the meaning of the invention.Cork also represents a wood-based material within the meaning of the invention.

[0134] Plastics that can be used in the production of corresponding panels or supports include, for example, thermoplastics such as polyvinyl chloride, polyolefins (e.g. polyethylene (PE), polypropylene (PP), polyamides (PA), polyurethanes (PU), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polyetheretherketone (PEEK) or mixtures or copolymers thereof. The plastics can contain common fillers, for example calcium carbonate (chalk), aluminum oxide, silica gel, quartz flour, wood flour, talc, fly ash, gypsum. They can also be colored in a known manner.

[0135] A "web-like carrier" can be understood as a carrier which, for example, in its manufacturing process, has a web-like length and thus a significantly greater length than its thickness or width, and whose length can, for example, be greater than 15 meters.

[0136] In the context of the present invention, a "plate-shaped carrier" can also be understood as a carrier that is formed by separating the web-like carrier and is designed in the form of a plate. Furthermore, the plate-shaped carrier can already predetermine the shape and / or size of the panel to be produced. However, the plate-shaped carrier can also be provided as a large plate. A large plate within the meaning of the invention is, in particular, a carrier whose dimensions exceed the dimensions of the final decorative panels by several times and which is divided into a corresponding plurality of decorative panels during the manufacturing process, for example by sawing, laser cutting, or waterjet cutting. For example, the large plate can correspond to the web-shaped carrier.

[0137] In the context of the present invention, lamination is understood to mean a material-to-material bonding of two layers by the action of pressure and / or temperature.

[0138] In the context of the present invention, thermal activation also includes a second, thermal curing.

[0139] In one embodiment of the invention, it can be provided that a printing substrate is applied to the plate-shaped carrier between steps a) and b).

[0140] For the purposes of the present invention, a printing substrate is understood to mean a layer which allows improved adhesion of the ink to the plate-shaped carrier.

[0141] The printing of the decoration with the above-described laminatable ink onto the plate-shaped carrier can be carried out using a conventional method. For example, the decoration can be produced with the laminatable ink using a flexographic printing, offset printing, or screen printing process. Preferably, the decoration can be produced with the laminatable ink using a digital printing technique, such as, in particular, an inkjet process.

[0142] This makes it possible to produce particularly individual decorations.

[0143] In a preferred embodiment of the invention, it can be provided that the decoration is produced from a plurality of differently colored, previously described, laminatable inks.

[0144] This makes it possible to produce multi-coloured decorations in particular.

[0145] In one embodiment of the invention, it can be provided that the curing of the decoration is carried out with electromagnetic radiation, preferably with UV radiation.

[0146] UV radiation can be understood in particular as radiation that lies in a wavelength range of, for example, 10-450nm, approximately 100-380nm.

[0147] This advantageously ensures that the laminatable ink is cured without impairing the thermal reactivation capability of the matrix.

[0148] Such radiation can be generated, for example, in a conventional manner using medium-pressure lamps. For example, a gas discharge lamp, such as a mercury vapor lamp, can be used.

[0149] In one embodiment of the invention, it can be provided that the wear and / or covering layer is a varnish, a resin or a film.

[0150] In one embodiment of the invention, the cover layer can be, for example, a liquid, lacquer-containing cover layer which is at least partially thermally cured, wherein the cured ink can be thermally activated and bond with the cured cover layer.

[0151] In one embodiment of the invention, it can be provided that the wear and / or cover layer is applied as a pre-produced overlay layer, for example based on melamine, onto the printed carrier and is bonded thereto by the action of pressure and / or heat, whereby the cured ink can be thermally activated and bonded to the wear and / or cover layer.

[0152] Furthermore, it may be preferred that a radiation-curable composition, such as a radiation-curable lacquer, such as an acrylic lacquer, is applied to form the wear and / or covering layer. The wear layer may contain hard materials such as titanium nitride, titanium carbide, silicon nitride, silicon carbide, boron carbide, tungsten carbide, tantalum carbide, aluminum oxide (corundum), zirconium oxide, or mixtures thereof to increase the wear resistance of the layer. The application can be carried out, for example, using rollers, such as rubber rollers, or using casting devices.

[0153] In a preferred embodiment of the invention, it can be provided that the cured ink is thermally activated during lamination at a temperature in a range of greater than or equal to 100 °C to less than or equal to 150 °C.

[0154] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises polymethyl methacrylate as polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 130 °C to less than or equal to 140 °C.

[0155] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises thermoplastic polyurethane as a polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 100 °C to less than or equal to 120 °C.

[0156] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises copolyamide as a polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 125 °C to less than or equal to 145 °C.

[0157] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises copolyester as polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 105 °C to less than or equal to 115 °C.

[0158] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises liquid polybutadiene as a polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 110 °C to less than or equal to 130 °C.

[0159] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises rosin-modified polyisobutene as a polymer and the cured ink is thermally activated at a temperature in a range of greater than or equal to 100 °C to less than or equal to 120 °C.

[0160] The temperature ranges described above ensure that the cured inks are thermally activated particularly well.

[0161] In a preferred embodiment of the invention, it can be provided that the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 2 bar to 70 bar, preferably greater than or equal to 10 bar to 50 bar.

[0162] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises polymethyl methacrylate as polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 5 bar to 70 bar, preferably greater than or equal to 15 bar to 60 bar.

[0163] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises thermoplastic polyurethane as the polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 2 bar to 55 bar, preferably greater than or equal to 8 bar to 50 bar.

[0164] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises copolyamide as a polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 2 bar to 70 bar, preferably greater than or equal to 7 bar to 65 bar.

[0165] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises copolyester as polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 3 bar to 70 bar, preferably greater than or equal to 4 bar to 63 bar.

[0166] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises liquid polybutadiene as a polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 4 bar to 70 bar, preferably greater than or equal to 5 bar to 55 bar.

[0167] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises rosin-modified polyisobutene as a polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 2 bar to 70 bar, preferably greater than or equal to 5 bar to 45 bar.

[0168] In a particularly preferred embodiment of the invention, it can be provided that the laminatable ink comprises liquid polybutadiene and rosin-modified polyisobutene as polymer and the decorative layer and the wear and / or cover layer are pressed together during lamination at a pressure in a range of greater than or equal to 4 bar to 70 bar, preferably greater than or equal to 5 bar to 55 bar.

[0169] The pressure ranges described above can ensure that the decorative layer and the sealing and / or covering layer have a particularly high bond strength.

[0170] Furthermore, the cover and / or wear layer can contain agents for reducing the static (electrostatic) charge of the final laminate. For example, the cover and / or wear layer can contain compounds such as choline chloride. The antistatic agent can be contained, for example, in a concentration between ≥0.1 wt.% and ≤40.0 wt.%, preferably between ≥1.0 wt.% and ≤30.0 wt.%, in the cover and / or wear layer composition.

[0171] Furthermore, it can be provided that a structure, in particular a surface structure that matches the decor, is introduced into the protective layer or wear or cover layer by introducing pores. It can be provided that the carrier plate already has a structure and an alignment of a printing tool for applying the decor and the carrier plate to one another takes place depending on the structuring of the carrier plate detected by means of an optical method. In order to align the printing tool and the carrier plate to one another, it can be provided that a relative movement between the printing tool and the carrier plate, which is necessary for alignment, takes place by moving the carrier plate or by moving the printing tool. Furthermore, it can be provided that a structuring of the decorative panels takes place after the application of the cover and / or wear layer.For this purpose, it can preferably be provided that a hardenable composition is applied as a covering and / or wear layer and a hardening process only takes place to the extent that only a partial hardening of the covering and / or wear layer occurs. A desired surface structure is embossed into the partially hardened layer using suitable tools, such as a hard metal textured roller or a stamp. The embossing takes place in accordance with the applied decoration. To ensure sufficient correspondence between the structure to be applied and the decoration, it can be provided that the carrier plate and the embossing tool are aligned to one another by appropriate relative movements. Following the introduction of the desired structure into the partially hardened covering and / or wear layer, the now structured covering and / or wear layer is further hardened.

[0172] In addition, a counter-layer can be applied on the side opposite the decorative side.

[0173] The invention is further explained below using examples. The examples illustrate possible embodiments of the invention. However, combinations or modifications of the embodiments are also possible within the scope of the invention.

[0174] The following tables provide examples of compositions of laminatable inks according to the invention. Wt. % refers to the mass fraction based on the laminatable ink.

[0175] The laminatable ink according to Example 1 had a violet color and was particularly easy to cure with UV radiation after being applied to a substrate using an inkjet printing process.

[0176] The resulting decorative layer was laminated with a wear-resistant layer in a press at 110°C and a pressure of 10 bar. This resulted in a stable bond without the need to apply an adhesive between the decorative layer and the wear-resistant layer. Example 1 material % by weight Isobornyl acrylate, glycidyl methacrylate 30-35% Urethane acrylates 10-15% Polyethylene glycol 5% Liquid polybutadiene 5-10% Thiophenylmorpholinopropanone 5% WHEEL SHAFT 2% 2-Hydroxy-4-octyloxybenzophenone 2% PV3:3 30-35% Rosin ester modified polyisobutene 2-5%

[0177] The laminatable ink according to Example 2 was brown in color and cured particularly well with UV radiation after being applied to a substrate using an inkjet printing process. The resulting decorative layer was also laminated with a wear-resistant layer in a press at 110°C and a pressure of 2.5 bar. This also formed a stable bond without the need to apply an adhesive between the decorative layer and the wear-resistant layer. Example 2 material % by weight Trimethylolpropane triacrylates 37-45% Melamine acrylates 10% Polyethylene glycol 5% Thermoplastic polyurethane 15% Alphaketone 4% WHEEL SHAFT 2% 2-Hydroxy-4-octyloxybenzophenone 2% NBr3 17-25%

[0178] The laminatable ink according to Example 3 was green in color and also cured particularly well with UV radiation after being applied to a substrate using an inkjet printing process. The resulting decorative layer was laminated with a wear-resistant layer in a press at 135 °C and a pressure of 8 bar. This also formed a stable bond without the need to apply an adhesive between the decorative layer and the wear-resistant layer. Example 3 material % by weight Isobornyl acrylate, glycidyl methacrylate 36-41% Urethane acrylates 15% Polyether 5% Copolyacrylate 10% Thiophenylmorpholinopropanone 5% WHEEL SHAFT 2% 2-Hydroxy-4-octyloxybenzophenone 2% PG4 20-25%

[0179] The laminatable ink according to Example 4 was yellow in color and also cured particularly well with UV radiation after being applied to a substrate using an inkjet printing process. The resulting decorative layer was laminated with a wear-resistant layer in a press at 130°C and a pressure of 5 bar. This also formed a stable bond without the need to apply an adhesive between the decorative layer and the wear-resistant layer. Example 4 material % by weight Isobornyl acrylate, glycidyl methacrylate 30% Urethane acrylate 15% Liquid polybutadiene 11-20% Alphaketone 5% WHEEL SHAFT 2% 2-Hydroxy-4-octyloxybenzophenone 2% NY11 26-35%

Claims

1. Laminatable ink, comprising a radiation-curable ink, in an amount, based on the laminatable ink, of ≥ 50 wt.-% to ≤ 99 wt.-% and a thermally activatable matrix material, in an amount, based on the laminatable ink, of ≥ 1 wt.-% to ≤ 50 wt.-%, wherein the matrix material comprises at least one thermally activatable polymer in an amount, based on the laminatable ink, of ≥ 1 wt.-% to ≤ 30 wt.-%, wherein the radiation-curable ink comprises a monomer, an oligomer, a photoinitiator, a stabilizer, an inhibitor, a dispersant and / or a dye, wherein the radiation-curable ink comprises a monomer in an amount of ≥ 25 wt.-% to ≤ 60 wt.-%, an oligomer in an amount of ≥ 5 wt.-% to ≤ 50 wt.-%, a photoinitiator in an amount of ≥ 1 wt.-% to ≤ 10 wt.-%, a stabilizer in an amount of ≥ 1 wt.-% to ≤ 3 wt.-%, a dispersant in an amount of ≥ 1 wt.-% to s 3 wt.-%, and a dye in an amount of ≥ 1 wt.-% to s 60 wt.-%, based on the laminatable ink, and the thermally activatable ink matrix material comprises a macromer in an amount of ≥ 1 wt.-% to ≤ 10 wt.-% and optionally a solvent in an amount of ≥ 0 wt.-% to ≤ 5 wt.-%, based on the laminatable ink, characterized in that the monomer comprises a monofunctional monomer selected from the group consisting of isobornyl acrylate, glycidyl methacrylate and mixtures thereof, and / or wherein the monomer comprises a difunctional monomer selected from the group consisting of 1,3-glycerol dimethacrylate, 1,10-decanedioldimethacrylate, tricyclodecane dimethanol diacrylate, 1,9-nonanediol dimethacrylate and mixtures thereof, and / or the monomer of trimethylolpropane trimethacrylate.

2. Laminatable ink according to claim 1, wherein the oligomer is selected from the group consisting of acrylic acrylate, urethane acrylate, melamine acrylate, epoxy acrylate, polyester acrylate and mixtures thereof.

3. Laminatable ink according to any one of claims 1 or 2, wherein the photoinitiator is selected from the group consisting of benzophenone, alpha ketone, thiophenyl morpholine propanone, thioxanthone and mixtures thereof.

4. Laminatable ink according to any one of the preceding claims, wherein the polymer is selected from the group consisting of polymethyl methacrylate, copolyacrylate, thermoplastic polyurethane, copolyamide, copolyester, liquid polybutadiene, colophony-modified polyisobutene and mixtures thereof.

5. Laminatable ink according to any one of the preceding claims, wherein the polymer has a number average molecular weight in a range of ≥ 700 g / mol to ≤ 20,000 g / mol.

6. Laminatable ink according to any one of claims 1 to 5, wherein the macromer is selected from the group consisting of polyoxyethylene chlorotriazine, polyoxypropylene chlorotriazine, polyethylene glycol, polyether, polystyrene butyl acrylate and mixtures thereof.

7. Laminatable ink according to any one of claims 1 to 6, wherein the solvent is selected from the group consisting of cyclohexanone, butanone, methyl ethyl ketone, xylene, ethyl acetate, ethyl lactate, dimethyl sulfoxide, dimethylformamide, formic acid and mixtures thereof.

8. Use of a laminatable ink according to any one of the preceding claims for producing a decorative layer, preferably a laminated decorative layer of a decorative panel.

9. Decorative panel comprising a decorative layer with a decoration produced by use of a laminatable ink according to any one of claims 1 to 7.

10. Method for producing a decorative panel according to the preceding claim, comprising at least the method steps: a. providing a plate-shaped carrier; b. printing a decoration with a laminatable ink according to any one of claims 1 to 7 onto at least a part of the plate-shaped carrier; c. curing the decoration with electromagnetic radiation, preferably with UV radiation; d. laminating at least a partial area of the decoration with a wear and / or cover layer, wherein the cured ink is thermally activated during the lamination of the decoration and forms a bond with the laminate.