coated paper sheet

Abstract

Coated paper sheet, wherein the coated paper sheet comprises a paper sheet and a partially hardened acrylate coating layer; wherein the partially hardened acrylate coating layer comprises at least one thermal initiator.

Description

[0001] This invention relates to a coated paper sheet for coated panels, in particular floor panels.

[0002] More precisely, the invention relates to a paper sheet for panels comprising a substrate and a top layer applied thereto, which has a decorative layer, for example, a decorative layer comprising a print. Such floor panels are generally known, for example from WO 97 / 47834. The floor panels disclosed in the aforementioned document relate, among others, to floor panels with a substrate that is mainly composed of an HDF sheet onto which a laminate layer is directly pressed, comprising one or more paper sheets impregnated with melamine resin, preferably also including a paper sheet with a print in, for example, a wood or stone motif, in particular a so-called decorative paper. The aforementioned melamine resin forms, among other things, a translucent wear layer over the decorative paper, but the transparency or translucency leaves much to be desired.On the underside of the substrate is a support layer or leveling layer, also based on a paper sheet impregnated with melamine resin. This support layer provides a compensating effect for tensile residual stresses present in the hardened melamine resin of the top layer. It remains possible to form extremely deep structures in the hardening melamine surface. So-called "white peaks" frequently occur. These are zones where inclusions are concentrated in the melamine surface. They mainly appear where deep depressions or structures are implemented.

[0003] It is known that the melamine surface of such a laminate panel leads to clicking noises when in use. Several solutions to this problem are known from the prior art. WO 03 / 016655 discloses the application of a sound-absorbing layer, such as a cork layer, beneath the melamine layer. It is known, among other things, from WO 2010 / 088769, to provide the melamine layers with a coating of a flexible monomer. WO 2009 / 101217 and WO 2010 / 070474 give examples of laminate panels in which the top layer is composed mainly of polyvinyl chloride (PVC) instead of melamine resin.

[0004] WO 2010 / 070474 discloses panels with a printed decorative layer that can be formed on the substrate and finished with a transparent PVC layer.

[0005] Furthermore, WO 01 / 47726 discloses a method for finishing panels with a printed decorative layer using a UV (ultraviolet) or electron beam curing acrylic resin. This process is difficult to integrate into existing laminate panel production methods and requires complex material logistics, sophisticated machinery, and results in high costs. For example, electron beam curing requires an inert atmosphere, making it possible to perform the treatment at the panel level. This technique is mainly applied to smaller panels or sheets in a physically enclosed lead chamber to neutralize the presence of harmful gamma radiation. These lead encapsulation components are thicker than 2.5 mm and extremely heavy. The photoinitiators required for UV curing have a detrimental effect on the quality of the resulting surface.Molecules used as photoinitiators are coming under increasing pressure due to the health risks they pose to humans.

[0006] Panels with a surface layer composed entirely of polyvinyl chloride (PVC) exhibit a loss of scratch resistance compared to conventional melamine surfaces. Furthermore, the PVC layer must be significantly thicker than a melamine layer to achieve comparable wear resistance. The texture and thickness of the PVC layer give the floor panel a plastic-like appearance, especially when imitating a product such as wood, stone, or ceramic. The texture achievable with a PVC layer is indistinct, which detracts from the realistic appearance of the resulting imitation.

[0007] In panels where the top layer is made of UV-cured or electron-beam-cured acrylate, as in WO 01 / 47726, advantageous surface characteristics are achieved. The relief that can be obtained in such a top layer is limited in that structural films must be applied, for example as in EP2019735.

[0008] The present invention is intended to provide a paper sheet for an alternative coated panel, thereby providing a solution to one or more of the problems with the prior art panels.

[0009] A coated panel, preferably a floor panel, wall panel, or furniture panel, is disclosed in a first independent aspect. It comprises at least one substrate and a top layer applied thereto, wherein the aforementioned top layer comprises at least one decorative layer and a translucent or transparent wear layer, characterized in that the aforementioned wear layer comprises a thermally cured acrylic resin and / or a thermally cured unsaturated polyester resin. Preferably, the resin is partially or completely cured during thermal curing.

[0010] In this document, a cured unsaturated polyester resin refers to a polyester resin that was unsaturated prior to curing and can be cured by crosslinking the double bonds in the unsaturated polyester resin.

[0011] The use of a thermally cured acrylic resin and / or a thermally cured unsaturated polyester resin opens up new possibilities for the design of the wear layer, while maintaining the excellent quality of a wear layer made of acrylic or unsaturated polyester resin. For example, the wear layer can thus be cured by hot pressing with a structured pressing element. Surprisingly, the inventors have found that the structure of the pressing element is quite advantageously replicated in the curing acrylic resin and / or the curing unsaturated polyester resin.In contrast to a curing melamine resin, the so-called chemical moisture or moisture that occurs as a byproduct of the reaction is not present in the curing reaction of the acrylate resin and / or the curing unsaturated polyester resin, so that the risk of the formation of inclusions in the translucent layer is limited, even when working with deep structures, for example with a local depth of more than 400 µm or even 1 mm or more in relation to the total surface area.

[0012] Furthermore, the inventors discovered that a thermally cured acrylic resin and / or a thermally cured unsaturated polyester resin can exhibit better transparency than a thermally cured melamine resin, such as that available in prior art laminate panels. The inventors attribute this to the significant shrinkage of a polycondensing melamine resin. For this reason, and due to the brittleness of the melamine resin, the cured melamine resin exhibits a considerable number of microcracks, which is not the case with the thermally cured acrylic resin-based wear layer of the invention.

[0013] Furthermore, the inventors were able to determine that tensile residual stresses that may be present in the wear layer after hardening are much lower in the case of the invention than in laminate panels of the prior art, so that the risk of the resulting panels or parts thereof exhibiting bending is significantly reduced, even when working without a carrier layer.

[0014] Furthermore, the resulting wear layer is softer than a melamine surface, and together with the lower tensile residual stresses in the surface, this characteristic allows for more acceptable scratching noises, especially for a noise comparable to that of real wood.

[0015] Furthermore, thermal curing enables more uniform curing than is the case with UV-cured acrylic resins. When using UV radiation for curing, the penetration depth of the light is limited. However, the thermal curing process of the invention can be initiated by means of one or more thermal initiators that are homogeneously or substantially homogeneously mixed with the acrylic resin or with the unsaturated polyester resin. In this way, the curing reaction can take place almost simultaneously and / or to the same extent across the entire thickness of a layer formed from acrylic resin or unsaturated polyester resin. Additionally, thicker cured layers can be formed, for example, layers with a thickness between 50 and 1000 µm, more precisely between 60 and 300 µm, and even more precisely between 100 and 300 µm.

[0016] The properties of the acrylate resin or the unsaturated polyester resin are primarily expressed when the aforementioned acrylate resin or the aforementioned unsaturated polyester resin is cured by at least one thermally initiated radical crosslinking reaction. The aforementioned curing preferably comprises at least one crosslinking of double carbon bonds present in the acrylate resin or in the unsaturated polyester, as may be the case with UV- or electron-beam-cured acrylate resins or unsaturated polyester resins.

[0017] According to one particular method, the aforementioned acrylate resin is cured both by a thermally initiated radical crosslinking reaction, in which the double carbon bonds present in the acrylate resin crosslink, and by a crosslinking reaction in which an oligomer or monomer with a hydroxyl (-OH) and / or an amine (-NH2) and / or a carboxyl (-COOH) functionality is crosslinked with an isocyanate, aziridine carbodiimide, or the like. This crosslinking reaction is promoted by the temperature used during the first crosslinking reaction. According to one particular example, the acrylate resin comprises or consists of a polyurethane acrylate resin.

[0018] It should be noted that the use of curing agents such as isocyanate or aziridine in a UV-curable coating is known to the inventors as dual curing. Such curing agents cause a second internal crosslinking, particularly of the hydroxyl (-OH-) and / or carboxyl (-COOH-) and / or amine (-NH2-) functional acrylate resins, to occur only in an uncontrolled manner and possibly with a long delay after the initial UV curing. The aforementioned particular method offers the possibility of providing coated panels with a wear layer obtained by applying a dual curing system, where the first crosslinking is thermally cured. Using the thermal energy of the first crosslinking, the second crosslinking is initiated in a controlled manner and can be completed in a short time. In other words, this is an "instant dual curing system."

[0019] According to one particular method, the curing of the acrylate resin or the unsaturated polyester resin is further promoted by a thermoset promoter, such as 2,4-pentanedione or N,N-diethylacetoacetamide, and / or by a thermoset accelerator, such as a cobalt-free accelerator, such as a copper or iron complex, or cobalt octoate, amine diethylaniline, dimethyl p-toluidine or ethoxylated p-toluidine.

[0020] It is clear that the presence of a thermal initiator in the acrylate resin or unsaturated polyester resin used can play an important role in the quality and relief aspects of the resulting wear layer.

[0021] A thermal initiator can be defined more generally as a thermally unstable molecule that decomposes or breaks down upon exposure to heat, at least into one or more radicals. The radicals produced then play the same role as the radicals produced in known photoinitiators during the UV curing of acrylate resins. The thermally generated radicals initiate the polymerization reaction of the double carbon bonds of the acrylate functionalities present in the acrylate resin.

[0022] For the same purpose as in the first aspect, a coated panel with at least one substrate and a top layer applied thereto is disclosed according to an independent second aspect, wherein the aforementioned top layer comprises at least one decorative layer and a translucent or transparent wear layer, characterized in that the aforementioned wear layer is based on a mixture of at least, on the one hand, an acrylate resin and / or an unsaturated polyester resin and, on the other hand, a thermal initiator. It is clear that the coated panels of the second aspect may have the features of the first aspect or of preferred embodiments thereof.In particular, the mixture may further comprise crosslinking agents such as isocyanate, aziridine, carbodiimide, or the like, so that the aforementioned wear layer is obtained by means of the instant dual curing system mentioned in connection with the first aspect. Furthermore, the mixture may also comprise thermoset promoters and / or accelerators as mentioned in connection with the first aspect of the invention.

[0023] Preferably, the aforementioned thermal initiator is an organic peroxide, preferably benzoyl peroxide, a methyl benzoyl peroxide, TPBIN (tertiary butyl peroxy-3,5,5-trimethylhexanoate), or lauryl peroxide. The inventors have found that these thermal initiators have a suitable minimum activation temperature required to achieve decomposition into at least one or more radicals, such that a sufficiently hardened wear layer can be obtained with acceptable energy consumption, particularly at a moderate curing temperature. Of the aforementioned peroxides, lauryl peroxide has the lowest activation temperature, and the curing of this resin can therefore be completed quickly.In some cases, however, for example, when significant indentations are to be formed in the wear layer during curing (e.g., 0.1 mm or more), or when adhesion to an underlying polyurethane layer is required, it is desirable for the resin to remain fluid for an extended period. In such cases, it is preferable to use at least benzoyl peroxide or methyl benzoyl peroxide as a thermal initiator. Of the latter, methyl benzoyl peroxide is the most advantageous because it yields the less toxic toluene as a reaction product, instead of benzene as in the case of benzoyl peroxide. It should also be noted that the reaction with lauryl peroxide leads to the formation of non-toxic aliphatics.

[0024] Other examples of organic and inorganic peroxides suitable as thermoinitiators are 2-butanone peroxide, persulfate, peroxydiphosphate and persulfate.

[0025] Other examples of peroxides suitable as thermoinitiators are ketone peroxide, diacyl peroxide, peroxyketal, hydroperoxide, peroxydicarbonate, peroxymonocarbonate, preferably tert-butylperoxy-3,5,5-trimethylhexanoate (TPBIN).

[0026] In addition to peroxides, azo polymerization initiators such as azonitrile, azo esters, hyponitrites, and / or azoamides can be used as an alternative. Specific examples include azobisisobutyronitrile (AIBN), 2-methylbutyronitrile (AMBN), and azovaleronitrile (AVN). Another alternative is the use of cesium ions.

[0027] Naturally, two or more of the aforementioned thermal initiators can be combined.

[0028] Preferably, the aforementioned mixture comprises 0.1-5 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin, and more preferably 0.5-2 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin, and more preferably 0.1-2 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin (if additional crosslinking with UV light is carried out, such a smaller amount of thermal initiator can be used to obtain a similar final cure). By changing the concentration of the thermal initiator, the resulting chain length of the polymerized acrylate resin or the polymerized unsaturated polyester resin can be adjusted. With larger amounts of thermal initiator, the reaction terminates sooner and shorter chain lengths are obtained, and with smaller amounts, longer chain lengths are obtained.A balance between the reaction rate and the degree of crosslinking or chain length is achieved with 0.5–2 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin. The time frame until partial or full curing is preferably such that sufficient resin flow can be achieved. Resin flow is important, for example, in a case where the structure of a press element is to be copied onto the surface of the wear layer. This specifically requires the displacement of the acrylate resin or the unsaturated polyester resin into all relief areas of the press element.

[0029] In the case of the aforementioned benzoyl peroxide, methyl benzoyl peroxide and / or lauryl peroxide, sufficient curing is achieved within an economically acceptable timeframe and with acceptable energy consumption using 0.5 to 2 parts per hundred parts of acrylate resin, while maintaining sufficient flow.

[0030] It is already evident from the above that the flow rate of the acrylate resin or the unsaturated polyester can be adjusted by selecting and concentrating the thermal initiator. In the case of acrylate resin, the flow rate can also be increased further by increasing the content of reactive dilution monomers or difunctional monomers, such as dipropylene glycol diacrylate (DPGDA), in the acrylate resin. Preferably, the acrylate resin comprises between 20 and 60 wt% monomers, preferably monofunctional and / or difunctional and / or trifunctional and / or tetrafunctional monomers.

[0031] Preferred embodiments that can be used in combination with the first, second, third and / or fourth aspect of the invention are discussed below.

[0032] Preferably, the wear layer of the coated panel of the first and / or second aspect comprises traces of a peroxide, such as benzoyl peroxide, methyl benzoyl peroxide and / or lauryl peroxide.

[0033] Preferably, the wear layer comprises at least traces of a reaction product resulting from the reaction of the thermal initiator and the acrylate resin. For example, the wear layer may comprise traces of benzene, toluene, or aliphatics.

[0034] Preferably, the aforementioned wear layer is uniformly or substantially uniformly hardened over its entire thickness.

[0035] Preferably, the thermal curing process comprises chemical crosslinking – preferably of the double carbon bonds present in the acrylate resin – and / or of the bonds present in the unsaturated polyester resin.

[0036] Double carbon bonds. Such a crosslinking reaction leads to extremely advantageous wear properties. By varying the concentration of initiators (thermal initiators and / or photoinitiators) and the amount of UV light when using additional UV curing added to the coating matrix before the pressing process, the degree and type of polymerization can be controlled. While it is known that EB curing occurs more homogeneously across the matrix, it can be observed that when working with thermal curing, in the case of specified texture depths and relief structures, a heat front is present, resulting in less homogeneous curing over time. This can affect the adhesion properties or the chain length of the matrix.

[0037] Preferably, the aforementioned wear layer is obtained based on a mixture containing at least, on the one hand, acrylate resin and / or unsaturated polyester resin and, on the other hand, a photoinitiator. More preferably, the mixture comprises 0.1–5 parts of a photoinitiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin.

[0038] More preferably, this mixture comprises 0.1-5 parts of two different photoinitiators per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin. Preferably, the photoinitiators are selected such that one photoinitiator cures the uppermost 20 µm of the wear layer (surface curing) and the other photoinitiator cures the wear layer more deeply (depth curing). This allows for advantageous curing of the wear layer.

[0039] Preferably, the decorative layer mentioned above comprises a substrate sheet, such as a sheet of paper, coated with synthetic material. This substrate may be, for example, a printed paper of the type used in the production of DPL-type laminate panels, and / or a paper with a Gurley value of less than 30 seconds, or even less than 25 or 20 seconds. The low Gurley value is advantageous for delivering the synthetic material mentioned above into the core of the paper. Preferably, the paper has a surface weight of 40 to 250 grams per square meter, and more preferably between 55 and 150 grams per square meter or between 65 and 90 grams per square meter. The higher surface weights, particularly between 90 and 150 grams per square meter, are preferably used in furniture panels, while the lower surface weights, particularly between 65 and 90 grams per square meter, are preferably used in floor panels.The printing can be done in an analog way, for example by means of an offset printing process with printing cylinders, and / or in a digital way, for example by means of an inkjet printing process, preferably in a so-called single-pass printer.

[0040] Instead of paper coated with synthetic material, it is also possible to use, for example, a film made of synthetic material as a decorative layer, such as a film made of PVC (polyvinyl chloride) or PET (polyethylene terephthalate), printed or unprinted, or a veneer. It should be noted that films made of synthetic material are an example of moisture-impermeable layers, and that the present inventors have found that, since no chemical moisture is produced during the curing of the acrylate resin, a thermally cured wear layer, in particular based on acrylate resin, can be formed on a film made of synthetic material or another impermeable layer. In the laminate layers of the panels of the prior art, the inventors assume that the chemical moisture migrates towards the substrate, and in the prior art, an impermeable layer above this substrate is undesirable.

[0041] Preferably, the synthetic material provided on the support sheet is a synthetic material comprising double carbon bonds.

[0042] According to a particular embodiment, the synthetic material provided on the substrate forms part of the aforementioned wear layer, with this part being located between the decorative layer itself, for example a printed pattern or a veneer, and the part of the wear layer formed by thermally cured acrylate. The part of the wear layer formed by the synthetic material of the decorative layer may include hard particles such as particles of aluminum oxide, silicon oxide, or silicon carbide.

[0043] Preferably, the synthetic material provided on the support sheet is selected from the following list: amino resins, urea-formaldehyde, melamine-urea-formaldehyde, melamine-formaldehyde, a polyurethane dispersion, a urethane-acrylic copolymer dispersion, acrylate, latex, melamine acrylate, reactive acrylate monomers, optionally in combination with a crosslinking agent such as carbodiimide, polyisocyanate, or aziridine. The synthetic material is preferably applied to the support sheet in a water-based mixture or dispersion, for example, by dipping, one or more roller applications, and / or one or more spray or pour applications. This dispersion can be stabilized anionically, cationically, or nonionically.In cases where this substrate includes a digitally printed decorative layer, the dispersion is preferably cationically stabilized to prevent any salts or acids in an optional inkjet receiver coating from destabilizing the polyurethane dispersion. It is, of course, not excluded that the aforementioned synthetic material is melamine formaldehyde. In such a case, a coating is applied, for example, to the surface of the substrate, which is provided with a synthetic material oriented towards the wear layer, to promote bonding with a thermally curing acrylic resin or a thermally curing polyester resin. Such a coating may comprise an aliphatic polyurethane dispersion, a latex dispersion, a water-based UV-curable substance such as water-based UV-curable acrylic resin, melamine acrylate, a chemically modified melamine resin, or an etherified melamine resin.It is, of course, not excluded that the aforementioned synthetic material is a thermally curable acrylate resin or an unsaturated polyester resin. The use of a cationically stabilized polyurethane dispersion, as in this case, for forming a coating on and / or impregnating a printed sheet of paper is in itself an important finding. Also disclosed, according to a separate independent aspect, is a method for producing coated panels with a substrate and a decorative top layer on a printed sheet of paper, characterized in that the method includes at least the step of applying a cationically stabilized polyurethane dispersion to the paper sheet that is printed or is to be printed.It is clear that the printing of this paper sheet is preferably carried out digitally and / or that this paper sheet comprises a previously applied coating with a pH value of less than 7, preferably 5 or lower, for example, an inkjet receiver coating. The present particular aspect may, of course, have other preferred features, such as those described earlier in this paragraph or in the context of the other aspects of the present invention. The polyurethane dispersion used may also have the following properties.

[0044] According to an important example, a polyurethane dispersion is applied to the substrate. Preferably, a polyurethane coating is obtained on the substrate with a König hardness of 20 to 160 seconds, 40 to 120 seconds, and preferably 40 to 100 seconds, more preferably 40 to 80 seconds. The inventor has found that this hardness results in better adhesion to the thermally curing acrylic resin or thermally curing unsaturated polyester resin of the wear layer. Polyurethane coatings with a higher König hardness can more easily lead to adhesion problems. Furthermore, the inventors have found that the softer polyurethane, particularly with a König hardness of 20 to 160 seconds, 40 to 120 seconds, and preferably 40 to 80 seconds, exhibits better scratch resistance. The polyurethane of the present example can also be located in the core of the substrate.According to another important possibility, the core of the carrier sheet is impregnated with a polycondensing resin, such as a melamine-based resin, while the polyurethane coating is mainly present on the surface of the carrier sheet. This possibility economically provides good splitting resistance of the carrier sheet while retaining the advantages of the polyurethane coating, such as reduced clicking or other noises. Preferably, the polyurethane coating has an elongation of between 40 and 400%, 100 and 300%, and more preferably 120 and 250%. The high elongation provides a bridge between the decorative paper, which, as mentioned above, may optionally have a core impregnated with a polycondensing resin, for example, a melamine-based resin, and the thermosetting acrylic resin.Preferably, the aforementioned acrylate resin is obtained on the basis of at least one multifunctional acrylate or methacrylate monomer and / or oligomer, such as a hexafunctional acrylate or methacrylate oligomer. A multifunctional acrylate or methacrylate oligomer provides a hard layer, but one that is as brittle and wear-resistant as possible.

[0045] According to the important example mentioned above, a polyurethane dispersion with a weight between 5 and 60 grams of dry matter per square meter and preferably between 10 and 20 grams of dry matter per square meter is preferably applied to the carrier sheet.

[0046] Preferably, the polyurethane dispersion used according to the important example mentioned above is water-based and comprises an acrylate functionality, and / or the dispersion comprises a UV acrylate, for example an epoxy-modified polyurethane acrylate, such as the commercially available NeoRad UV20 40W. Improved adhesion with thermally curing acrylate resin can be obtained using the present preferred embodiment.

[0047] To promote film formation in the PU dispersion, preferably 1 to 10% by weight, preferably 2 to 6%, of solvent is used in the dispersion. For example, DPnB (dipropylene glycol n-butyl ether), DPM (dipropylene glycol methyl ether), PM (propylene glycol methyl ether), 2-butoxyethanol, or diethylene glycol can be used.

[0048] Preferably, the PU dispersion has an MFFT (minimum film formation temperature, ISO 2115) between 0 and 40 °C, between 6 and 20 °C and preferably between 5 and 15 °C.

[0049] A reactive 100% acrylate primer can also be used. This primer penetrates the melamine layer and can be covalently bonded to the transparent topcoat that is applied later. This acrylate primer can be composed, for example, of HDDA (1,6-hexanediol diacrylate), ACMO (acryloylmorpholine), melamine acrylate, or acidic adhesion promoter acrylate.

[0050] Preferably, the aforementioned acrylate resin is obtained based on at least one monofunctional or difunctional acrylate or methacrylate monomer and / or oligomer. A difunctional acrylate or methacrylate oligomer provides a tough or less brittle, wear-resistant layer. Trifunctional and / or tetrafunctional acrylates can also be used.

[0051] It is preferable to work with acrylate monomers or oligomers, as these are more reactive than methacrylate monomers and oligomers.

[0052] Preferably, the aforementioned acrylate resin is of the aliphatic type. Using such an acrylate resin, aging and / or discoloration are limited to a maximum extent.

[0053] Preferably, the acrylate resin comprises 5 to 80% by weight of monomers, or more preferably 5 to 60% by weight, which may be monofunctional, difunctional, or multifunctional. Monomers in the acrylate resin can have one or more of the following effects: increasing the viscosity to the desired value, increasing adhesion through better absorption in adjacent layers, such as the substrate, or positively or negatively influencing the reactivity in the decorative layer, significantly influencing the flexibility and / or brittleness of the resulting wear layer, defining the operating range, for example, with regard to the temperature to be used, and positively influencing chemical resistance. For example, improved crosslinking, curing, and chemical resistance can be achieved with a multifunctional monomer. For this purpose, a trifunctional monomer such as TMPTA can be used, for example.Given their short chain length, difunctional monomers can also promote crosslinking and curing. For example, DPGDA (dipropylene glycol diacrylate) monomer can be used, maintaining sufficient flow during curing.

[0054] According to the most preferred embodiment, the aforementioned acrylate resin is obtained on the basis of at least a mixture of two or more acrylate oligomers with different functionalities, preferably on the basis of a mixture of a multifunctional acrylate oligomer, where "multi" is to be understood as more than two, and a difunctional acrylate oligomer. With such a mixture, the desired hardness and toughness of the final wear layer can be determined.

[0055] The use of acrylic resin as a wear layer also allows for the incorporation of acrylates with special properties. For example, the aforementioned acrylic resin can be obtained with at least one chemically modified acrylate, such as a fluoroacrylate. Adding chemically modified acrylates to the acrylic resin can achieve properties such as water repellency, ease of cleaning, fingerprint resistance, and antimicrobial properties. Other possible additives to the acrylic resin include metallic pigments and materials that improve tactile interaction. The additives mentioned here have no or virtually no effect on the thermal curing of the acrylic resin.

[0056] Preferably, at least hard particles such as aluminum oxide particles, silicon oxide particles, or silicon carbide particles are added to the acrylate resin or the unsaturated polyester resin. Alternatively, the aforementioned hard particles are located between the aforementioned decorative layer and the portion of the wear layer formed by the acrylate resin and / or thermally cured unsaturated polyester resin. In the case of a decorative layer comprising a substrate coated with synthetic material, the aforementioned hard particles may be located within a layer formed by this synthetic material. Preferably, at least 5 grams or at least 10 grams per square meter of such hard particles are added. Such particles can further increase the wear resistance.Preferably, the particles have a mesh size of F100 or smaller, but preferably not less than F320. The latter corresponds approximately to an average particle size between 30 and 125 µm. The wear resistance of the resulting wear layer can also be adjusted by means of its thickness, whether in combination with the presence of hard particles or not. Preferably, the wear layer based on thermally cured acrylate resin has a thickness of at least 50 µm and preferably at least 100 µm.

[0057] Preferably, the aforementioned wear layer is obtained using 10 to 300 grams per square meter of the aforementioned acrylic resin or unsaturated polyester resin. In the case of a furniture panel, the wear layer is preferably obtained using 10 to 80 grams (dry matter) – and preferably 10 to 30 grams (dry matter) – per square meter of the acrylic resin or thermally cured unsaturated polyester resin, while in the case of a floor panel, the wear layer is preferably obtained using 30 to 160 grams per square meter of the acrylic resin or unsaturated polyester resin.

[0058] Preferably, in a coated panel according to any embodiment of any aspect of the invention, the wear layer is composed of different layers. The wear layer comprises several layers that have the features described as embodiments for the wear layer in the first and / or second and / or fourth aspect of the invention and / or are obtained by any embodiment of the method of the third aspect.

[0059] The thermally cured acrylate resin or the unsaturated polyester resin can be applied in the wear layer in several layers, and these layers can be identical in chemical formulation, but they can also differ from each other to optimize the performance-to-cost ratio or to optimize the flow behavior in the press.

[0060] Preferably, the compositions of these multiple layers differ from one another. More preferably, the uppermost layer of the wear layer comprises one or more fluorinated acrylates, microaluminum oxides, silicone acrylates, or nanosilicon dioxides.

[0061] Preferably, the coated panel, according to one of the independent aspects, is a floor panel, preferably suitable for floating installation. The wear layer can exhibit particularly high wear and / or scratch resistance, but is also sufficiently soft to achieve a significant improvement in noise performance compared to conventional melamine surfaces.

[0062] Preferably, the coated panel has a relief on its surface. Preferably, the relief also exhibits variations in gloss. These variations in gloss can occur in zones with at least two respective gloss levels, whereby these gloss levels can be clearly distinguished by the user and thus with the naked eye. More precisely, it is preferred that at least two gloss levels are used for each of the aforementioned selectable zones, such that specified zones clearly manifest as matte zones, while other zones manifest as non-matte or glossy zones. Most of the matte zones on the coated panel, for example, of a floor panel, preferably have a gloss level of 10 or more, preferably less than 10, while the less matte or glossy zones have a gloss level of more than 10 and more preferably more than 20, all of which are measured according to DIN 67530.Regardless of the absolute gloss levels used, the difference in gloss level between the matte and glossy zones of the coated panel is preferably at least 10.

[0063] With the same purpose as in the first and second aspects, the present disclosure further relates, according to an independent third aspect, to a method for producing coated panels, wherein the panels comprise at least a substrate and a top layer applied thereto, and the aforementioned top layer comprises at least a decorative layer and a translucent or transparent wear layer, characterized in that the method comprises at least the following steps: - the step of applying one or a combination of an acrylate resin, an unsaturated polyester resin, or a coating composition comprising an acrylate resin to the aforementioned decorative layer; wherein the acrylate resin, the unsaturated polyester resin, or the coating composition optionally comprises a thermal initiator and optionally a photoinitiator; and - the step of at least partially curing the aforementioned acrylate resin or unsaturated polyester resin or coating composition by means of hot pressing to form at least a portion of the aforementioned wear layer. It goes without saying that the acrylate resin, the unsaturated polyester resin or coating composition, and the optional thermal initiator can be based on the options mentioned in connection with the first and / or second aspect above.Preferably, the coating composition or the acrylate resin comprises at least one multifunctional acrylate oligomer and 0.5 to 2 parts of benzoyl peroxide, methyl benzoyl peroxide, or lauryl peroxide as a thermal initiator per 100 parts of acrylate resin; and more advantageously, 0.1 to 2 parts of benzoyl peroxide, methyl benzoyl peroxide, or lauryl peroxide as a thermal initiator per 100 parts, and more favorably, 0.1 to 1 part of benzoyl peroxide, methyl benzoyl peroxide, or lauryl peroxide as a thermal initiator per 100 parts. Curing under pressure maximizes the potential of thermally cured acrylate resin or thermally cured unsaturated polyester resin. It is clear that the aforementioned instant dual curing system can also be used in this case, employing the smaller amounts of the thermal initiator.

[0064] When using an acrylate resin - regardless of whether it is a coating composition mentioned above or not - or an unsaturated polyester resin, preferably an acrylate resin or an unsaturated polyester resin comprising oligomers and monomers is used.

[0065] Preferably, in the process according to the third aspect of the disclosure, at least hard particles such as aluminium oxide particles, silicon oxide particles or silicon carbide particles are added to the acrylate resin or the unsaturated polyester resin or the coating composition.

[0066] Preferably, the aforementioned pressing is carried out using a so-called short-cycle press or one-day press. It is, of course, not excluded that it is possible to use a continuous-type press, preferably one that uses moving press belts between which the workpiece moves, or a hot-press roller. It is also possible to use a continuous-type press that employs one or more press cylinders, which are preferably textured. The invention is of particular importance for the texturing of wear layers using press cylinders (in texturing, the top layer of the coated panel is provided with a relief).In this process, the dwell time under pressure is particularly short, and fast-curing acrylic resin or fast-curing polyester resin can sufficiently conform to the structure of the molded element even during such a short dwell time. This process creates a relief on the top layer of the coated panel, precisely replicating the different gloss levels.

[0067] Preferably, the aforementioned pressing is carried out at a temperature of 70 to 220 °C (and preferably at a temperature of 120 to 220 °C) and / or at a pressure of 5 to 80 bar. The inventors have obtained advantageous results when pressing in a short-cycle press at 195 °C and 40 bar (approximately 40 kg / cm²). 2) for 22 seconds. Such process parameters correspond to those used in the pressing of melamine-based laminate panels. However, such high temperatures and pressures are not required when pressing thermosetting acrylic resins or thermosetting unsaturated polyester resins, and the process parameters can be adjusted over a wide range, in particular reduced, until the desired effectiveness is achieved.

[0068] As mentioned above, the thermally curing acrylate resin – including the acrylate resin in the coating composition – or the thermally curing unsaturated polyester resin preferably exhibits sufficient flowability when used with a structured pressing element. For this purpose, it is preferable to use at least benzoyl peroxide or methyl benzoyl peroxide as the initiator.

[0069] The inventors have determined that it can be important to rapidly increase the pressing pressure so that the deformations caused by the pressing element to form the desired structure in the surface and / or substrate of the panel are carried out before the acrylic resin has essentially cured. This is also important in cases where the wear layer of thermally curing acrylic resin is to adhere to an underlying layer, such as one comprising polyurethane, like a backing sheet or decorative paper treated on its surface with a polyurethane dispersion, as described above.

[0070] Preferably, the aforementioned pressing is carried out using a structured pressing element, such as a structured pressing plate, for example of the type known per se from WO 2009 / 043910.

[0071] During pressing, a frame or rack is used that extends along all edges of the material being pressed. The purpose of this frame or rack is to prevent the acrylic or unsaturated polyester resin from splashing out of the press as the pressure increases. Furthermore, selecting the appropriate thickness of the frame or rack allows for precise control over the desired thickness of the wear layer. The frame or rack also ensures that sufficient pressure is applied to the curing acrylic or unsaturated polyester resin.

[0072] According to a particular embodiment, the disclosed method further comprises the step of post-curing the pressed wear layer by means of ultraviolet and / or electron radiation, both preferably carried out under an inert atmosphere. According to an important example of the present particular embodiment, a surface can be achieved that exhibits relief and / or gloss variations comparable to those achievable in a melamine surface, but with the quality and noise characteristics of an electron-beam-cured surface. For this purpose, the wear layer, pressed and structured by means of a pressing element, can be post-cured by means of electron radiation under an inert atmosphere.

[0073] Preferably, the aforementioned pressing is carried out on a stack comprising at least the substrate, the decorative layer, and the acrylic resin, unsaturated polyester resin, or coating composition. This results in a process that, in many aspects, corresponds to the production process for laminate panels, allowing the aforementioned process to be easily integrated into existing laminate production lines.

[0074] Preferably, the step of applying the acrylate resin or unsaturated polyester resin or coating composition to the aforementioned decorative layer is carried out while the decorative layer is already part of a stack comprising at least the substrate and the decorative layer.

[0075] Preferably, the decorative layer mentioned above comprises a substrate, such as a sheet of paper, and the method preferably includes at least the step of coating this substrate with synthetic material. The method may further include the step of coating the synthetic material with hard particles such as particles of aluminum oxide, silicon oxide, or silicon carbide.In practice, this step can be carried out in various ways, for example by mixing the hard particles into the synthetic material before it is provided on the support sheet, or by introducing the hard particles into the synthetic material after it has already been provided on the support sheet, for example by scattering these particles or by roller application, spraying or blasting of flowable mixtures or dispersions comprising these particles.

[0076] Preferably, the step of providing this carrier sheet with synthetic material comprises at least the application of a water-based or water-borne UV-curable synthetic material to the aforementioned carrier sheet.

[0077] Preferably, the step of coating this substrate sheet with synthetic material comprises at least the application of a UV-curable substance, for example, an acrylate resin and / or an unsaturated polyester, wherein this substance further comprises a thermal initiator. This can be a so-called hydro-UV or a complete hydro system containing a thermal initiator. Solvent-based acrylates can also be used; after drying, these form a non-adherent film. Such systems can comprise relatively long oligomers.

[0078] The treated substrate can be dried to a non-sticky state. The final curing of the oligomers can then occur during pressing.

[0079] As mentioned above, the synthetic material provided on the support sheet preferably further comprises hard particles such as corundum particles, e.g. aluminium oxide particles.

[0080] It should be noted that the step of applying the acrylic resin, unsaturated polyester resin, or coating composition to the aforementioned decorative layer can be carried out in two or more partial steps. Such an embodiment makes it possible to apply a larger quantity of the aforementioned acrylic resin, unsaturated polyester resin, or coating composition in a more homogeneous manner. Furthermore, it is possible to apply different compositions of the acrylic resin, unsaturated polyester resin, or coating composition in the respective partial steps.For example, it is possible to add acrylates with a specific functionality, such as acrylates that offer increased cleanability, only to the layers of acrylate resin that are closest to the surface of the panel or that are intended to form the surface of the panel, or to add hard particles such as aluminium oxide only to certain layers.

[0081] Furthermore, it should be noted that if the coating composition, the acrylic resin, or the unsaturated polyester resin includes photoinitiators, this coating composition, acrylic resin, or unsaturated polyester resin can be gelled before pressing and / or post-cured after pressing by UV irradiation with or without an inert atmosphere (to counteract oxygen inhibition). In the case of the aforementioned possibility, where the coating composition, acrylic resin, or unsaturated polyester resin is applied in two or more partial steps, UV irradiation before pressing is not necessarily required on all partial layers.For example, it is advantageous not to gel at least the topmost sub-layer so that sufficient flow of the coating composition, acrylate resin or unsaturated polyester resin is maintained during pressing in order to produce depressions in this layer by means of a structured pressing element such that thermally cured coating composition, thermally cured acrylate resin or cured unsaturated polyester resin is still present at the deepest point of this depression, and / or to produce gloss differences in this layer by means of a pressing element with gloss differences.

[0082] The use of photoinitiators and UV irradiation prior to pressing results in a pressing surface that is dry, or at least to a certain degree, for pressing. Dry processing can be desirable in the production process for various reasons, such as to facilitate intermediate storage and / or stacking. Such a dry or semi-dry condition can also be achieved in other ways. Several important methods are listed below.

[0083] Preferably, the coating composition used in the method comprises at least: an acrylate resin, one or more components comprising free hydroxyl groups, one or more components comprising free isocyanate groups, optionally one or more thermal initiators, optionally photoinitiators, and optionally one or more crosslinkers. Thermal initiators, photoinitiators, and crosslinkers mentioned in the other aspects of the invention may be used. Furthermore, the coating composition may comprise hard particles as described in the other independent aspects of the invention.

[0084] Preferably, the coating composition comprises a hydroxy-functional acrylate and / or a hydroxy-functional urethane acrylate.

[0085] Preferably, the coating composition comprises an isocyanate polymer and / or an isocyanate-functional acrylate.

[0086] Preferably, in the aforementioned hot pressing process, a condensation reaction occurs between hydroxyl and isocyanate groups of the coating composition, resulting in cross-linking in the coating composition.

[0087] Preferably after the step of applying the coating composition, the acrylate resin or the unsaturated polyester resin to the aforementioned decorative layer; and before the step of at least partially curing the aforementioned coating composition, the acrylate resin or the unsaturated polyester resin by means of hot pressing to form at least a part of the aforementioned wear layer; the method comprises the step of removing water and / or solvent from the coating composition, from the acrylate resin or from the unsaturated polyester resin.

[0088] Preferably following the step of applying the coating composition, the acrylate resin, or the unsaturated polyester resin to the aforementioned decorative layer; and prior to the step of at least partially curing the aforementioned coating composition, the acrylate resin, or the unsaturated polyester resin by hot pressing to form at least a portion of the aforementioned wear layer; the method comprises the step of gelling the coating composition, the acrylate resin, or the unsaturated polyester resin to a non-viscous state. Such embodiments have the advantage that a non-sticky intermediate product, for example in a rolled state, can be obtained before carrying out the hot pressing.

[0089] Preferably, the process after hot pressing comprises the step of UV post-curing of the pressed wear layer, whereby cross-linking of double bonds occurs. For this purpose, the coating composition, the acrylate resin, or the unsaturated polyester resin preferably comprises photoinitiators. This UV curing preferably takes place under an inert atmosphere.

[0090] Preferably, the process after hot pressing comprises the step of thermal post-curing the pressed wear layer, whereby cross-linking of double bonds occurs. For this purpose, the coating composition, the acrylate resin, or the unsaturated polyester resin preferably comprises thermal initiators. Preferably, the thermal post-curing after hot pressing is carried out at a higher temperature than the hot pressing itself.

[0091] In a preferred embodiment of the method, prior to the step of applying the aforementioned decorative layer, or a combination thereof, the coating composition, the acrylate resin, or the unsaturated polyester resin, to the aforementioned decorative layer, the method comprises the step of applying an adhesion promoter to the aforementioned decorative layer. Preferably, the adhesion promoter comprises or consists of one or more polyurethanes, polyurethane dispersions, water-based polyurethane dispersions, polyurethane dispersions with acrylate functionality, melamine acrylates, or acrylate primers. Preferably, a reactive, low-viscosity acrylate primer is used. Adhesion promoters such as those described in the first and / or second aspect of the invention can be used in the method of the third aspect of the disclosure.

[0092] Preferably, the application of the coating composition, the acrylate resin or the unsaturated polyester resin, or a combination thereof, to the aforementioned decorative layer is carried out using a wet or dry process.

[0093] When using a coating composition in the process, this coating composition preferably comprises a solvent, for example, butyl acetate. The use of a coating composition comprising a solvent has several advantages. When the coating composition is applied to a decorative layer that is thermoplastic, this solvent acts on this thermoplastic decorative layer. In this way, better adhesion to the decorative layer is obtained after the wear layer has cured. Examples include the use of a decorative layer comprising a thermoplastic film, for example, polyvinyl chloride (PVC); and more preferably, a printed thermoplastic film, more preferably a printed thermoplastic polyvinyl chloride film (PVC film).Examples include decorative layers formed by pressing thermoplastic substrates, where these thermoplastic substrates may contain fillers such as wood fibers or inorganic fillers such as calcium, clay, or chalk. Such thermoplastic substrates can include polyvinyl chloride (PVC), polyethylene, or polypropylene as the thermoplastic material.

[0094] In a preferred method, wherein the pressing is carried out using a continuous press or a hot-press roller, the method preferably comprises the step of applying the decorative layer to the substrate by rolling the decorative layer off a roller. This decorative layer is preferably a film of synthetic material, a printed film of synthetic material, or a printed sheet of paper, and is preferably impregnated with a thermally curing resin. More preferably, the coating composition is applied to the decorative layer by a dry process involving rolling it off a roller.

[0095] Preferably, after hot pressing, a relief is pressed into the wear layer, and after pressing in the relief, the wear layer is post-cured thermally or by means of UV radiation. Such an embodiment makes it possible to achieve high-quality decorative effects. During hot pressing, the wear layer is partially thermally cured. However, the wear layer still possesses sufficient plasticity to allow a relief to be pressed into it in a subsequent process – whether hot or not. Due to the plastic behavior of the wear layer, this can be done in the form of a pressed relief without the formation of cracks in the wear layer. During the subsequent post-curing, for example, thermally or by means of UV radiation, the wear layer is further hardened so that it can acquire its final properties.In this post-curing process, the use of UV radiation is preferred, as this also enables efficient curing in deep and narrow reliefs. For example, such a process allows the production of panels with surface layers that realistically simulate wood, even by pressing a relief precisely into the decorative layer with a printed wood pattern. This is also possible with the invention when using thermoplastic substrates, such as substrates comprising polypropylene, polyethylene, or polyvinyl chloride, with or without fillers such as wood fibers or wood particles, or inorganic fillers such as calcium, clay, or chalk.

[0096] In a preferred method, the substrate comprises a thermoplastic material, preferably PVC, polypropylene, or polyethylene. Preferably, this thermoplastic material is filled with fillers. The decorative layer comprises a film made of synthetic material, for example, a polyvinyl chloride film, and more preferably, this film made of synthetic material is printed. Alternatively, the decorative layer can comprise a print on the substrate or consist of a print made of the substrate itself.

[0097] In a preferred method, the substrate comprises or consists of a wood fiberboard (such as MDF or HDF); and the decorative layer comprises a printed carrier sheet, preferably a printed paper sheet. The carrier sheet is preferably impregnated with a thermosetting resin.

[0098] Furthermore, the process can also be carried out according to a number of possibilities, which are discussed below. If acrylate resin is specified, these possibilities also apply to the use of the coating composition that includes an acrylate resin.

[0099] According to one possibility, the acrylate resin or the unsaturated polyester resin or the coating composition is applied via a two-component lacquer. This two-component lacquer can be dried by physical curing, while the thermally curing acrylate component or the thermally curing unsaturated polyester component is cured by hot pressing.

[0100] According to a second approach, two thermal initiators with different SADTs (self-accelerating decomposition temperatures) are used in the acrylate resin or the unsaturated polyester resin. The lowest SADT is preferably selected to be below the pressing temperature, allowing this thermal initiator to become effective before pressing or before the activation of the other thermal initiator. Activating a thermal initiator with the lowest SADT can achieve a certain degree of drying.

[0101] A third option involves applying the acrylate resin as a 100% solid using both a photoinitiator and a thermal initiator. The acrylate resin can then be gelled using UV radiation to achieve a degree of drying. The coated paper can then optionally be stored at a temperature below the SADT (Safety Average Dry Point) of the thermal initiator. Further or complete curing is then achieved during hot pressing. After pressing, it is possible to perform further curing using UV radiation.

[0102] A fourth option involves using a hydro- or water-based lacquer with both a photoinitiator and a thermoinitiator. This method can be used in the same way as the third option, with the similar possibility of performing further curing after pressing.

[0103] A fifth option involves using a solvent-based acrylic resin or unsaturated polyester resin containing a thermal initiator and / or a photoinitiator. After application of the solvent-based resin, the solvent is evaporated at a low temperature, resulting in a tack-free surface. Curing occurs during panel pressing, ideally with additional UV curing after pressing.

[0104] A sixth possibility involves the use of a dual-curing varnish, combining hydroxyl-functional acrylates with isocyanate-functional acrylates. This varnish includes photoinitiators and / or thermal initiators. After solvent evaporation, the varnish is non-sticky, and curing is achieved through cross-linking of the hydroxyl and isocyanate groups, with concurrent curing via the double carbon bonds.

[0105] A seventh option involves using a hydro- or water-based lacquer, primarily with a thermal initiator, to initiate the radical reaction. The acrylic resin can then be gelled using hot air or (N)IR radiation. The coated paper can then optionally be stored at a temperature below the SADT of the thermal initiator. Further or complete curing is then achieved during hot pressing. After pressing, further curing using UV radiation is possible, provided a photoinitiator is used.

[0106] According to another possibility, various options from those mentioned above can be combined in different sub-layers, possibly with intermediate accompanying drying or gelation or partial hardening.

[0107] In general, within the scope of the present invention, it is preferred that the aforementioned thermally cured acrylic resin layer or the thermally cured unsaturated polyester covers the entire surface of the floor panel, optionally with the exception of recessed edge areas, for example in the form of chamfers or so-called beveled edges. In this way, sufficient water resistance is provided to the entire surface.

[0108] For the same purpose as in the first to third aspects, the present disclosure, according to an independent fourth aspect, also relates to a coated panel with at least one substrate and a top layer applied thereto, wherein the aforementioned top layer comprises at least one decorative layer and a translucent or transparent wear layer, characterized in that the aforementioned wear layer comprises an acrylate, wherein this acrylate comprises covalent bonds formed by the reaction of hydroxyl groups with isocyanate groups. Coated panels according to the fourth aspect of the disclosure can be produced by the process of the third aspect of the disclosure, using an acrylate resin or a coating composition comprising an acrylate resin.

[0109] In coated panels according to the fourth aspect of the disclosure, an adhesion promoter is preferably located between the decorative layer and the wear layer. Preferably, the adhesion promoter comprises or consists of one or more polyurethanes, polyurethane dispersions, water-based polyurethane dispersions, polyurethane dispersions with acrylate functionality, melamine acrylates, or acrylate primers, for example, a reactive low-viscosity acrylate primer. Adhesion promoters mentioned in the other aspects of the invention may also be applied in this case.

[0110] Coated panels according to the fourth aspect of the disclosure preferably include a relief in the wear layer. Preferably, this relief structure exhibits gloss variations.

[0111] Preferably, coated panels according to the fourth aspect of the disclosure have a decorative layer which displays a wood pattern by printing, and the wear layer comprises a relief in conformity with the wood pattern, and the relief more preferably comprises gloss differences in conformity with the wood pattern.

[0112] Preferably, coated panels according to the fourth aspect of the disclosure comprise a substrate comprising a thermoplastic material, for example, polyvinyl chloride, polyethylene, or polypropylene. Preferably, this thermoplastic material comprises one or more fillers, for example, wood fibers or inorganic fillers such as calcium, clay, or chalk. The decorative layer comprises a film of synthetic material or a printed film of synthetic material, or the decorative layer comprises a print on the substrate.

[0113] Preferably, coated panels according to the fourth aspect of the disclosure comprise a substrate that includes or consists of a wood fiberboard (such as MDF or HDF). The decorative layer comprises a printed carrier sheet, preferably a printed paper sheet, and preferably a printed paper sheet impregnated with a thermosetting resin.

[0114] It is clear that the method of the third aspect is preferably used to produce the coated panels of the first and / or the second aspect and / or the fourth aspect and / or the preferred embodiments thereof.

[0115] It is clear that the coated panels of the first, second, or fourth aspect, and / or those obtained according to the third aspect, may exhibit different structures. Several important possibilities are listed below, without this list being exhaustive.

[0116] According to a first possibility, the coated panel comprises a wood fiberboard as a substrate, a printed paper sheet coated with synthetic material as a decorative layer, and the wear layer according to the invention. According to an important example, the printed paper sheet comprises a polyurethane coating, at least on the surface facing the wear layer. Preferably, the paper sheet is impregnated in its core with a melamine-based resin, such as a modified melamine resin. The polyurethane coating preferably has a König hardness of 50 to 70 seconds. The wear layer preferably contains traces of benzene, toluene, benzoyl peroxide, or methyl benzoyl peroxide. Preferably, hard particles, such as corundum particles, are located above the printed paper sheet.Preferably, the coated panel has on its surface, more precisely in the wear layer, a structure or relief with sections of 400 µm depth or deeper and / or relief sections that penetrate into the substrate.

[0117] According to a second option, the coated panel comprises a substrate made of synthetic material or a synthetic composite, more precisely a thermoplastic polymer or a thermoplastic composite. This could be, for example, a substrate based on filled PVC (polyvinyl chloride), PP (polypropylene), PET (polyethylene terephthalate), or PU (polyurethane). The filler can include calcium carbonate or talc, or another powder or substance such as wood chips, bamboo chips, and / or other plant components. In the case of PVC, it can be rigid, semi-rigid, or flexible PVC, specifically with a plasticizer content of less than 5, between 5 and 15, or more than 15 parts per hundred parts PVC, respectively. The filler content can vary considerably and can reach up to 80 or 85 percent by weight of the composite.The decorative layer can, for example, comprise a print configured on a film made of synthetic material, such as a PVC film. According to the invention, the wear layer then comprises at least one part based on a thermally cured acrylate or a thermally cured unsaturated polyester. It is understood that the wear layer can also comprise further parts, such as a transparent film made of synthetic material, for example, a transparent PVC film, which is preferably located beneath the part formed by the thermally cured acrylate or thermally cured unsaturated polyester. This embodiment enables the provision of sharp relief properties and excellent surface characteristics on the surface of a panel composed primarily of thermoplastic material.

[0118] According to a third possibility, the coated panel comprises a substrate that is at least partially cured together with the wear layer, which consists of a coating composition, an acrylic resin, or an unsaturated polyester resin, and preferably also a decorative layer. The substrate can, for example, be based on a textile layer, woven or nonwoven, such as a spunbond nonwoven layer, like a textile layer based on glass fibers, steel fibers, and the like, which is preferably coated with a thermally curable synthetic material, such as a thermally curable acrylic resin or a thermally curable unsaturated polyester. It is possible to produce a coated panel of this third possibility in a single step by pressing a stack of the textile layer coated with synthetic material, the decorative layer, and the wear layer in a hot press.In this way, an extremely thin but stable plate can be obtained, such as a plate with a thickness of less than 4 mm or even 2 mm or thinner.

[0119] According to a fourth possibility, the coated panel comprises a substrate and a wear layer according to the invention, wherein the decorative layer is formed by the surface of the substrate. This can be the case, for example, with decorative panel materials such as wood panel materials, for instance, for the application of the invention with solid wood parquet or oriented strand board (OSB).

[0120] According to a fifth possibility, the top layer is formed as mentioned above in one of the first to seventh possibilities, however, the substrate is formed by a fiber cement board, magnesium oxide-based board, polyolefin-based board, particleboard, OSB, filled soft PVC board, filled hard or rigid PVC board, foam board made of synthetic material, preferably a so-called closed-cell foam board made of synthetic material, a multi-layer board such as a multiplex board or a board made of synthetic material with both layers of soft PVC and layers of hard PVC or rigid PVC.

[0121] With the same purpose as in the first to fourth aspects, the present disclosure, according to an independent fifth aspect, also relates to a coated panel with at least one substrate and a top layer applied thereto, wherein the aforementioned top layer comprises at least one decorative layer, characterized in that a thermally cured acrylic resin or a thermally cured unsaturated polyester resin is present between the aforementioned decorative layer and the substrate, and / or that the decorative layer is formed at least partially by a thermally cured acrylic resin or a thermally cured unsaturated polyester resin. According to this fifth aspect, the coated panel thus does not necessarily have a wear layer.Should this indeed be the case, this wear layer will not necessarily be based on a thermally cured acrylic resin or a thermally cured unsaturated polyester resin. The inventors have determined that the presence of a thermally cured acrylic resin or a thermally cured unsaturated polyester resin at any position in the top layer can lead to an improvement in click noise and other surface properties. Naturally, the acrylic resin or polyester resin and / or the thermal initiators used in connection with the fourth aspect can be the same as those discussed in connection with the first through fourth aspects, it being understood that they do not necessarily have to result in a transparent or translucent layer.

[0122] Preferably, the decorative layer mentioned above comprises at least one carrier sheet, such as a sheet of paper, wherein thermally cured acrylic resin or thermally cured unsaturated polyester resin forms the bond between the carrier sheet and the substrate. It is clear that the paper sheets described above can be used for this purpose.

[0123] Preferably, in the fourth aspect, the thermally cured acrylic resin or thermally cured unsaturated polyester resin is configured to be colored, for example by comprising pigments such as titanium dioxide. In such a case, the invention may relate to a white panel that can be used as such, for example, as a furniture panel, or that can be used as a semi-finished product in a process, wherein the white layer is used as a printing substrate for printing yet to be carried out.

[0124] Preferably, thermally cured acrylate resin or thermally cured unsaturated polyester resin forms a base layer for printing carried out on it, which at least partially forms the aforementioned decorative layer.

[0125] According to an alternative embodiment, the aforementioned decorative layer is a veneer, wherein thermally cured acrylic resin or non-thermally cured unsaturated polyester resin preferably extends from the underside of the veneer into and / or through pores, cracks, and other openings present in the veneer. As mentioned above, the acrylic resin or polyester resin is preferably colored. In this way, the acrylic resin or polyester resin can form a colored filling on the surface of the veneer at the location of openings such as knots and cracks.

[0126] In the context of the four aspects mentioned above, it is also noted that a wood fiberboard such as an MDF or HDF board can be used for the substrate. According to a particular embodiment, a low-density wood fiberboard is used, especially one with an average density of less than 750 kg per cubic meter, or even 650 kg per cubic meter or less. The use of such a low-density board contributes to a further improvement in noise reduction, such as the clicking sound, when using the coated panel, primarily in cases where these panels are used as floor panels in a floating installation. The use of such low-density wood fiberboards is made possible in part by the lower tensile residual stresses in the surface of the panels mentioned in the preceding aspects.In particular, there is a limited risk that tensile stresses in the surface layer could cause the upper edges to curl up. With prior art laminate panels, such a phenomenon is usually prevented or limited by increasing the panel density. With the surface layer of the panels described in the present disclosure, this is no longer necessary.

[0127] According to a particular embodiment, a substrate is used that is free of unbound formaldehyde or formaldehyde-free. The can can, for example, be a wood fiberboard bonded with pMDI (polymeric methylenediphenyl diisocyanate) adhesive. In this case, if the top layer is also formaldehyde-free, for example, consisting mainly of paper and thermosetting acrylic resin and / or polyurethane, a completely formaldehyde-free or formaldehyde-free coated board is obtained.

[0128] Furthermore, it should be noted again that the invention, considered in its entirety, allows the aforementioned top layer to include a water-impermeable layer. This is made possible by the fact that, unlike melamine-formaldehyde, thermally curing acrylic resin or thermally curing unsaturated polyester resin does not produce so-called "chemical" water as a byproduct during polymerization. When pressing or curing melamine resin, it is important that this chemical water can escape, either into the substrate or to the surface, and in such a case, water-impermeable layers are an obstacle to be avoided. Preferably, the aforementioned water-impermeable layer is formed by a layer located between the aforementioned decorative layer and the substrate.In this way, any moisture present on the surface of the coated panel cannot penetrate the substrate, and a highly dimensionally stable panel can be obtained even under fluctuating humidity. This is important, for example, in cases where the aforementioned substrate comprises or consists of a wood fiberboard. According to another possibility, the aforementioned waterproof layer is formed by an ink layer that at least partially forms the aforementioned decorative layer. Other examples of waterproof layers include TPU films (thermoplastic polyurethane), polyester-based layers, aluminum foils, especially non-perforated aluminum foil, and the like. In accordance with all these embodiments, the dimensional stability of the coated panels can be increased.

[0129] In general, it should be noted that the present invention, in all its aspects, can be applied separately to coated panels in which the decorative layer comprises a print based on UV-cured inks. As explained in WO 2014 / 024100, UV-cured inks can form a strong barrier to the aforementioned chemical water of a melamine polycondensation reaction, leading to various undesirable effects on the surface of the panels. The present invention prevents or limits the formation of chemical water by using a thermally curing acrylic resin in the top layer.

[0130] It is clear that, in the context of the present invention, the wear layer is considered to be the entire layer between the printed decorative layer and the surface of the panel. It is further clear that this wear layer is preferably composed substantially or even entirely of the aforementioned thermally cured acrylic resin or thermally cured unsaturated polyester resin, or the cured coating composition comprising an acrylic resin. It is also not excluded that the wear layer on the surface of the panel comprises a further surface coating and / or that part of the wear layer is formed by synthetic material that is initially applied to a carrier sheet of the decorative layer, as mentioned above.

[0131] According to a particular embodiment, the aforementioned wear layer comprises a sheet of material, such as a sheet of paper. Such a sheet significantly contributes to the impact resistance of the floor panels and reduces the risk of the typically hard but brittle wear layer cracking. The sheet makes the wear layer more ductile, which is also important for the subsequent processing of the floor panel edges. The ductility of the wear layer reduces the risk of splintering edges when milling the optional coupling elements. Furthermore, such a sheet forms a barrier against the displacement of wear-resistant or hard particles into the still-moist wear layer during production, allowing these particles to be more effective in the finished floor panel.According to the most preferred embodiment, the wear layer comprises a sheet of material containing embedded hard particles. For example, this can be a so-called Mead layer, such as that described in US 5,820,937, wherein an alpha-cellulose paper is filled with aluminum oxide particles or other wear-resistant particles during its production. In such an embodiment, the hard particles are held in a fixed position within the thickness of the wear layer, and no special measures are required to keep the hard particles suspended in the varnish layer or other material of the wear layer. The latter results in a reduced risk of transparency loss due to the addition of suspending agents and a smoother production process.When processing the edges, there is also a lower risk of hard particles detaching, as these are held together to some extent in the material sheet.

[0132] As mentioned above, the coated panel of the disclosure is preferably a floor panel, particularly intended for floating installation. Preferably, the floor panel is further characterized in that mechanical coupling elements are provided on at least two opposite edges and that, when two such floor panels are coupled, these coupling elements create a clamping effect between the upper edges, particularly the wear layers, at the point of the edges. With such an embodiment, reliable watertightness of the edges can be achieved. This is important, for example, in cases where a porous and / or wood-based substrate is used, such as MDF or HDF.

[0133] According to a particular embodiment, the aforementioned substrate is provided on at least two opposite edges with a coating or impregnation that prevents or limits the penetration of moisture into the substrate. In the case of a coating, the coating is preferably configured to overlap the edge of the top layer. In other words, according to this embodiment, a moisture-resistant coating is provided at the edge of the floor panel, with this coating extending from the substrate at least beyond the boundary with the aforementioned top layer. Preferably, the coating extends further, in particular at least beyond the boundary with the decorative layer and / or the wear layer.

[0134] In cases where low-density fiberboard, particularly with a density of less than 750 or less than 650 kg per cubic meter, is used for floor panels with mechanical coupling devices, measures are preferably taken to improve the quality of the material at the edges of the substrate. For example, reinforcement or impregnation with MDI or PU can be carried out at the edges. Another possibility is the application of an acrylic resin to these edges, which can then preferably be cured by electron beam curing. This curing can optionally be achieved together with the aforementioned UV or electron beam post-curing. Preferably, the acrylic resin applied to the edges is a layer of viscous acrylic resin.Another option is to apply urea-formaldehyde (UF), melamine-formaldehyde (MF), or another resin for pressing, at least at the points where the coupling agents are ultimately to be formed. Furthermore, the substrate can be impregnated with PU or MDI from the underside. In most existing click systems, such as those of WO 97 / 47834, it is important that the bottom area of ​​the board, particularly where the bottom groove lip of a locking tongue-and-groove joint is located, is secure.

[0135] As mentioned above, the wear layer is preferably provided with a structure or relief formed by indentations on its surface. Preferably, this structure contributes to imitating the pattern depicted in the printed decorative layer and / or the structure forms a boundary of the printed decorative layer, for example, at least at one edge thereof. For example, in the case of wood imitations, it is possible to work with indentations in the form of wood pores and / or veins. According to another example, it is possible to work with a boundary of the decorative layer in the form of chamfers or other edge finishes. In the case of stone decor, it is possible to work with a structure that imitates the presence of mortar joints. As mentioned above, the invention makes it possible to form such a structure or relief with deep indentations, for example, with indentations of 400 µm or deeper.For example, chamfers or other edge finishes with a depth of 400 µm can be formed.

[0136] Preferably, the wear layer is provided with structural elements that penetrate the substrate, or in other words, the decorative layer and the underlying substrate are also structured. This embodiment is particularly interesting when implementing structural elements such as edge banding, as it allows them to be given a deep configuration despite the limited thickness of the wear layer. The resulting relief in the decorative layer itself also contributes to the realistic imitation of the panel.

[0137] As mentioned above, in the case of a structure or relief with deep depressions and / or structural components that penetrate the substrate, a sufficient flow of thermally curing acrylate resin is preferably provided, for example by selecting benzoyl peroxide or methyl benzoyl peroxide as the thermal initiator.

[0138] According to one embodiment, the disclosure, in accordance with one or more of its preceding aspects, relates to a decorative profile instead of a coated panel. This can be, for example, the type of profile used for finishing a floor covering, such as a transition profile, end profile, skirting board, or the like. This embodiment allows for the uniform production of profiles suitable for decorative panels, for example, particularly suitable for the aforementioned coated panels. According to the present embodiment, the invention can lead to a decorative, floor-quality profile that can be produced more easily, thus allowing greater freedom in the design of such profiles.

[0139] The acrylate resin used in the various aspects of the present invention may, for example, have the following composition: - 5 to 80% by weight monomers, or more preferably 5 to 60% by weight, which may be monofunctional, difunctional or multifunctional, preferably selected from the list of cyclic monofunctional monomers (CTFA (cyclic trimethylolpropane formal acrylate), TMCHA (trimethylcyclohexyl acrylate), TBCHA (4-tert-butylcyclohexyl acrylate), IBOA (isobornyl acrylate), THFA (tetrahydrofurfuryl acrylate) etc.), alkoxylated monofunctional monomers (PE4A etc.), alkane monofunctional monomers (EOEOEA (2-(2-ethoxyethoxy)ethyl acrylate)), alkoxylated difunctional monomers, alkyl difunctional monomers, multifunctional monomers (TMPTA (trimethylolpropane triacrylate), GPTA (propoxylated glycerol triacrylate), PET(T)A (Pentaerythritol tri(tetra)acrylate) etc.), acid-based adhesion promoter monomers; mono-, di- or multifunctional acrylate or methacrylate monomers are preferably used, preferably trifunctional ones, so that the risk of unpleasant odors is limited; as a special example, TMPTMA (trimethylolpropane trimethacrylate) can be used. - Additives such as defoaming agents and leveling agents at 0.1 to 10% by weight; preferably, a leveling agent and / or a defoaming agent are used at 0.1 to 2% by weight; for example, a silicone polyether acrylate such as TEGO Rad 2300 can be used as the leveling agent; BYK 1790 can be used as the defoaming agent; - to 0.1 to 30 wt% and more preferably 1 to 10 wt% nanosilicon dioxide or corundum (Al2O3); for example, a dispersion of colloidal (nano-)silicon dioxide in a monomer such as a difunctional acrylate monomer may be used, or a dispersion of (nano-)silicon dioxide in butyl acetate or methoxypropyl acetate, or aluminum oxide platelets, for example with a particle size distribution between 3 and 18 µm; - 5 to 80 wt% oligomers of unsaturated polyester, polyester acrylate, urethane acrylate, polyether acrylate, melamine acrylate, polycarbonate acrylate, epoxy acrylate, amine-modified acrylate or urethane (meth)acrylate, preferably a urethane (meth)acrylate with 2 to 10 functional groups and / or a urethane acrylate with the formula AIPIA, wherein • A: Acrylic or methacrylic, mono- or polyfunctional • I: Isocyanate (aliphatic monomeric or oligomeric di- or multifunctional) • P: Polyol - long- or short-chain polyester, polyether, polycarbonate, di- or multifunctional; - possibly fillers, pigments and / or reinforcing agents; - a thermal initiator, preferably organic peroxide or an azo polymerization initiator, in a quantity of 0.1 to 5 percent by weight; - if necessary, add a photoinitiator at a rate of 0.1-5% by weight; - optionally, add a crosslinking agent such as isocyanate, carbodiimide and / or aziridine at a weight of 0.1-5 percent.

[0140] It should also be noted that the use of urethane acrylate has the additional advantage of hydrogen bonding, resulting in a favorable flexibility-to-hardness ratio of the resulting layer. It is also possible to work with, or use in addition to, so-called "special high-functionality urethane acrylates," such as silicone-based, hydrophilic functional, or fluorinated acrylates.

[0141] Optionally, the aforementioned composition, or the acrylate resin to be cured, or the cured saturated polyester in general, may also comprise a photoinitiator, for example, 0.1 to 10% by weight, preferably 1 to 10% by weight. These may be, for example, photoinitiators such as hydroxyacetophenones, acetophenones, aminoacetophenones, phosphine oxides, benzophenones, thioxanthones, benzoyl formates, or polymeric photoinitiators. These may, for example, be benzophenone or a phosphine oxide such as diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide. Such a composition may further comprise an amine synergist, for example, 1 to 10% by weight. Such a synergist promotes UV curing.The presence of a photoinitiator allows for additional UV curing after thermal curing, such as after hot pressing, to apply a structure to the acrylic resin layer, for example, a wear layer. Alternatively, the photoinitiator can be used to gel the acrylic resin or unsaturated polyester resin to perform thermal curing. For example, the acrylic resin or unsaturated polyester resin can be gelled on a support sheet, such as a printed or decorative paper, before this support sheet is incorporated into a stack to be pressed. Gelation can also be used to apply a support layer to the underside of the substrate.

[0142] Furthermore, the aforementioned composition may optionally comprise a UV absorber, for example 0.1 to 5 wt%, preferably 1 to 2% or 1.5%. The UV absorber may be 2-hydroxyphenyl-s-triazine, possibly containing 15-25% 2-methoxy-1-propyl acetate (for example, BASF Tinuvin 477), or bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate containing methyl-1,2,2,6,6-pentamethyl-4-piperidyl sebacate (for example, BASF Tinuvin 292).

[0143] Other optional components of the aforementioned composition are matting agents such as pyrogenic silicon dioxide, whether wax-treated or not, precipitated silicon dioxide, micronized organic polymer, polycondensed.

[0144] For example, a matting agent of this type can be used at a concentration of 0.1 to 8 percent by weight. Practical examples of suitable matting agents are Evonik Acematt 3600 and PQ Corporation Gasil UV55C. Furthermore, optional components of the aforementioned composition include additives that facilitate cleaning, anti-slip additives, and antimicrobial additives.

[0145] Below are several examples of possible compositions: EXAMPLE 1 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 60% difunctional aliphatic urethane acrylate • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1-5%, preferably 0.5-5%, particularly preferably 1% TBPIN thermoinitiator, i.e., tertiary butylperoxy-3,5,5-trimethylhexanoate • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 2 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 40% difunctional aliphatic urethane acrylate • 5-40%, preferably 20% trifunctional epoxy acrylate • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1–5%, preferably 0.5–5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 3 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 40% difunctional aliphatic urethane acrylate • 5-40%, preferably 20% trifunctional epoxy acrylate • 5-40%, preferably 18% trifunctional monomer (GPTA-propoxylated glycerol triacrylate) • 0.1–5%, preferably 0.5–5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 4 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 40% trifunctional aliphatic urethane acrylate, i.e., includes additional isocyanate groups for “instant double curing” (isocyanate groups) • 5-40%, preferably 20% trifunctional epoxy acrylate • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1–5%, preferably 0.5–5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 5 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 50% difunctional aliphatic urethane acrylate • 5-30%, preferably 10% silicon acrylate (2 to 6 functional), i.e., a “special high-functionality urethane acrylate” that increases cleanability. • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1–5%, preferably 0.5–5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 6 - Wet process with simple thermal curing • 10-40%, preferably 20% hexafunctional aliphatic urethane acrylate • 30-80%, preferably 50% difunctional aliphatic urethane acrylate • 2-15%, preferably 10% nanosilicon dioxide dispersed in TMPTA monomer; this results in increased scratch resistance • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1–5%, preferably 0.5–5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 7 - Wet process with gelation - or completely dry process The same formulations as in Examples 1 to 6 can be used, but with an additional 0.1-5% (and preferably 0.5-5%) photoinitiator such as benzophenone, 1-hydroxycyclohexyl phenyl ketone, XBPO (phosphine oxide-phenyl-bis(246-trimethylbenzoyl)), TPO (C 22 H 21P O2) or ITX (isopropylthioxanthone). It is not only possible, but even desirable, to add a mixture of photoinitiators, with one photoinitiator used for surface curing and the other for deep curing of the varnish. According to another practical example, the thermally curing acrylate resin consists of the following components: - 53.7 parts of an aliphatic urethane acrylate resin; - 0.3 parts benzoyl peroxide; - 46 parts dipropylene glycol diacrylate; - possibly defoaming agents, leveling agents, nanosilicon dioxide and / or corundum (Al2O3). EXAMPLE 8 - Wet process (solvent-based) with gelation - Coating composition, comprising (all components in percent by weight or parts by weight) • 100 parts of component A, consisting of: ◯ 40-90% hydroxy-functional acrylate, in butyl acetate as solvent (30-60% solvent), ◯ 0.01-1% crosslinker, for example of an organometallic compound such as dibutyltin dilaurate or zinc neodecanoate, ◯ 0.1-5% photoinitiator, ◯ 0.1-2% UV absorber, ◯ 0.1-2% light stabilizer, ◯ 5-40% mono-, di-, tri- or tetrafunctional acrylate monomer • 5-20 parts of an isocyanate, for example aliphatic polyisocyanate. EXAMPLE 9 - Wet process (solvent-based) with gelation - Coating composition, comprising (all components in percent by weight or parts by weight) • 30-70 parts of component A, consisting of: ◯ 40-90% hydroxy-functional acrylate, in butyl acetate as solvent (30-60% solvent), ◯ 0.01-1% crosslinker, for example of an organometallic compound such as dibutyltin dilaurate or zinc neodecanoate, ◯ 0.1-5% photoinitiator, ◯ 0.1-2% UV absorber, ◯ 0.1-2% light stabilizer, ◯ 5-40% mono-, di-, tri- or tetrafunctional acrylate monomer • 30-70 parts of an isocyanate-functional acrylate in solvent EXAMPLE 10 - Wet process (solvent-based) with gelation - Coating composition, comprising (all components in percent by weight or parts by weight) • 50-90 parts of component A, consisting of: ◯ 40-90% hydroxy-functional urethane acrylate, in butyl acetate as solvent (30-60% solvent), ◯ 0.01-1% crosslinker, for example of an organometallic compound such as dibutyltin dilaurate or zinc neodecanoate, ◯ 0.1-5% photoinitiator, ◯ 0.1-2% UV absorber, ◯ 0.1-2% light stabilizer, ◯ 5-40% mono-, di-, tri- or tetrafunctional acrylate monomer • 10-50 parts of an isocyanate-functional acrylate in solvent EXAMPLE 11 - Wet process with simple thermal curing • 10-80%, preferably 50% unsaturated polyester • 10-50%, preferably 20% tetrafunctional polyester acrylate • 5-40%, preferably 18% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 0.1–5%, preferably 0.5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 12 - Wet process with simple thermal curing • 10-80%, preferably 50% unsaturated polyester • 10-50%, preferably 20% tetrafunctional polyester acrylate • 2-20%, preferably 10%, 10-functional aliphatic urethane acrylate • 5-40%, preferably 15% difunctional monomer dipropylene glycol diacrylate (DPGDA) • 1-8%, preferably 3% aluminum oxide • 0.1–5%, preferably 0.5%, particularly preferably 1% TBPIN thermal initiator • 0.5-1.5%, preferably 1% leveling agent EXAMPLE 13 - Wet process with gelation - or complete dry process

[0146] The same formulations as in Examples 1 and 2 can be used, but with an additional 0.1–5% photoinitiator such as benzophenone, 1-hydroxycyclohexyl phenyl ketone, XBPO (phosphine oxide-phenyl-bis(246-trimethylbenzoyl)), TPO (C 22 H 21P O2) or ITX (isopropylthioxanthone). It is not only possible, but even desirable, to add a mixture of photoinitiators, with one photoinitiator used for surface curing and the other for deep curing of the varnish.

[0147] To better explain the features of the invention, some preferred embodiments are described below as examples, without being in any way limiting, with reference to the accompanying drawings, wherein: Fig. Figure 1 shows a perspective view of a coated panel, more precisely a floor panel; Fig. Figure 2 shows an enlarged area along line II-II of Fig. 1; Fig. Figure 3 is a schematic view of several steps in a method for realizing the invention; Fig. 4 and Fig. Figure 5 shows results of sound measurements of a panel with the features of the invention; and Fig. Figure 6 shows a method for realizing the invention.

[0148] Fig. Figure 1 shows a coated panel 1. In this case, it is a rectangular floor panel comprising a substrate 2 and a top layer 3 applied thereon, with at least one decorative layer 4 and a translucent or transparent wear layer 5. The wear layer 5 comprises a thermally cured acrylic resin, the curing being achieved by means of a thermally initiated radical crosslinking reaction. For this purpose, the starting material is a mixture of acrylic resin and a thermal initiator. The wear layer may also comprise a cured polyester resin or a cured coating composition comprising an acrylate.

[0149] The floor panel 1 is suitable for floating installation and for this purpose is provided in this case with mechanical coupling means 10 on both the long edge pair 6-7 and the short edge pair 8-9, which make it possible to connect two such floor panels 1 to each other on their respective edges 6-7-8-9.

[0150] Fig. Figure 2 again clearly shows that at least the long edge pair 6-7 of the floor panel 1 is made of Fig. 1 is provided with mechanical coupling means 10, mainly in the form of a tooth 11 and a groove 12, wherein in the coupled state of two such floor panels 1 there is a locking between the tooth 11 and the groove 12 at these edges 6-7 both in a first direction R1 perpendicular to the surface 13 of the coupled panels 1 and in a second direction R2 perpendicular to the coupled edges 6-7 and in the plane 13 of the panels 1.

[0151] Preferably, the short edges 8-9 are, as in the embodiment of Fig. 1 and Fig. 2. If mechanical coupling means 10 are also provided which effect a locking in the corresponding directions, mainly or not mainly in the form of a tooth 11 and a groove 12.

[0152] For the embodiment of Fig. 2 A substrate 2 is used, comprising a wood fiberboard with a density of 750 kg per cubic meter or less. To improve the bond strength of the existing coupling agents 10, the substrate 2 is impregnated with MDI (methylene diphenyl diisocyanate) 14 at its edges 6-7. As mentioned above, it is particularly important that at least the bottom lip 15, which flanks the groove 12, is configured to be sufficiently strong. Impregnation or other reinforcement of the substrate material 2 near the upper edges 16 is also desirable to limit possible swelling due to penetration and / or pressure effects during the milling of the coupling agents 10.

[0153] In this example, a support layer 18 is also provided on the underside 17 of the panel 1. This is preferably carried out on a thermally cured acrylic resin and serves primarily to form a barrier against rising damp. As explained in the invention, the wear layer 5 has a lower level of residual stresses, so the support layer 18 performs only a minimal function as a leveling layer. The support layer 18 can therefore also be omitted, particularly in cases where the substrate 2 itself is composed of waterproof material and / or has a water-repellent underside 17 and / or is treated to be at least somewhat water-repellent on the underside 17 of the substrate 2, for example by impregnating the substrate material on the underside 17 with MDI.

[0154] The decorative layer 4 of the floor panel 1 of Fig. 1 and Fig. 2 comprises a carrier sheet coated with synthetic material 19, more precisely a paper sheet 20 with a surface weight of approximately 70 grams per square meter. The paper sheet 20 displays a print 21 in the form of a wood motif. The synthetic material 19 used comprises double carbon bonds and is more precisely polyurethane.

[0155] Fig. Figure 3 again shows a schematic view of several steps in a process for producing the floor panel of Fig. 1 and Fig. 2.

[0156] In this example, a decorative layer 4, comprising at least one sheet of paper 20, is used as a base. The sheet of paper 20 itself is printed with a design 21. In a first step S1, the sheet of paper 20, or more precisely, a paper web from which the sheet of paper 20 will later be obtained by cutting, is coated with synthetic material 19. For this purpose, the paper web is unwound and impregnated in its core with a first synthetic material 19. The core impregnation can limit the risk of splitting of the sheet of paper 20 in the final coated panel 1. In this example, this core impregnation takes place in two steps: a first step S1A, in which synthetic material 19 is applied using a roller 22, and a second step S1B, in which the sheet of paper 20 is immersed in a bath 23 containing the synthetic material 19.In this example, the synthetic material 19 applied in the first step S1A and in the second step S1B is the same. However, it is also possible for the synthetic materials used in the first and second steps to differ, regardless of the specific application technique employed. Between the first step S1A and the second step S1B, the paper sheet 20 follows a trajectory 24 that allows sufficient penetration of the first synthetic material 19 applied during the first step S1A. As mentioned in the introduction, it is possible to use modified melamine-formaldehyde resin, modified urea-formaldehyde resin, or modified melamine-urea-formaldehyde resin as the first synthetic material 19. Preferably, the first synthetic material 19 comprises double carbon bonds.Preferably, the first synthetic material 19 is selected from the list of polyurethane, urethane-acrylic copolymer, acrylate, latex and a dispersion in combination with acrylate functionality.

[0157] Fig. Figure 3 further shows that, following the core impregnation mentioned above, aluminum oxide particles can be applied in a third step S1C, for example, as in this case, by means of a scattering treatment. This is preferably followed in a fourth step S1D by a drying treatment in a hot air oven 25. Optionally, in a fifth step S1E, an interlamellar coating 26 can be applied to the side of the print 21 and / or the side of the paper sheet 20 that is to face the wear layer 5, which increases the compatibility with the wear layer 5 to be formed from thermally curing acrylate resin or thermally curing unsaturated polyester resin or a coating composition comprising an acrylate resin.Such an interlamellar coating can be composed, for example, of a water-based polyurethane coating, a water-based UV-curing substance, or a melamine acrylate or reactive acrylate monomer. During the same step S1E or in a separate step, a coating 27 can also be applied to the side of the paper sheet 20 that is intended to face the substrate 2. The purpose of such a coating 27 is to ensure better adhesion to the substrate 2. Alternatively, such a coating 27 can also serve the purpose of noise reduction. In the latter case, polyurethane, for example aromatic polyurethane or thermoplastic polyurethane (TPU), is preferably used.After applying the interlamellar coating 26 and / or the coating 27, a drying treatment similar to that of the fourth sub-step S1D can be carried out again, as in the example.

[0158] In a seventh step S1F, the treated paper sheet 20 in this example passes through a cooling roller 28, and the paper web is divided into sheets.

[0159] In a second step S2, a stack 29 is formed which includes at least the substrate 2 and the decorative layer 4, wherein the decorative layer 4 in this case comprises a printed paper sheet 20 which is provided with synthetic material 19 which was obtained in step S1.

[0160] The process of the disclosure comprises at least the third step S3 shown, in particular the step of applying an acrylate resin (or an unsaturated polyester resin or a coating composition comprising an acrylate resin) comprising a thermal initiator, to the decorative layer 4, and the fourth step S4 shown, in particular the step of at least partially curing the aforementioned resin by hot pressing. In the third step S3, an acrylate resin with a thermal initiator is applied to the underside 17 of the substrate 2 to form a carrier layer 18. It is clear that in this case, the third step S3, in particular the step of applying the resin to the decorative layer 4, is carried out while the decorative layer 4 is already part of a stack 29 comprising at least the substrate 2 and the decorative layer 4.

[0161] In the example shown, pressing is carried out using a so-called short-cycle press 30, and more precisely using a structured pressing element 31 or a pressing plate. The pressing is performed on a stack 29 comprising the substrate 2, the decorative layer 4, the acrylate resin of the wear layer 5, and the carrier layer 18. During pressing, the structure 32 of the pressing element 31 is copied into the surface of the wear layer 5.

[0162] Fig. Figure 4 shows the results, represented by curves 33-34, of noise measurements taken on the melamine surface of a prior art floor panel (curve 33) and on a thermally cured acrylic surface of a floor panel according to the invention (curve 34). These are measurements of loudness in phons, shown on the ordinate 35, as a function of frequency (Hz), shown on the abscissa 36, ​​of a scratching noise produced on this surface with a metal pin. Loudness is a variable that objectively reflects the subjectively perceived noise level. In the results for the melamine surface, shown in curve 33, an extremely large and broad peak can be found in the frequency interval from 1000 to 5000 Hz, in which the human ear is most sensitive. This noise is perceived as disturbing by users.

[0163] When the same scratching is performed on a thermally cured acrylic surface, the results in curve 34 show a significantly lower absolute loudness in the same interval. This leads to the perception of a warmer and less high-pitched sound, comparable to the sound produced on a wooden surface.

[0164] Fig. Figure 5 shows the results, represented by curves 37-38, of sound level measurements carried out on the one hand on a melamine surface of a prior art floor panel (curve 37) and on the other hand on a thermally cured acrylate surface of a floor panel according to the invention (curve 38). The prior art floor panel comprises a substrate made of HDF, in particular a wood fiberboard with an average density of about 950 kg per cubic meter.

[0165] The floor panel according to the disclosure comprises a substrate made of MDF, more precisely a wood fiberboard with an average density of about 650 kg per m³. 3 The results are measurements of the loudness in phons, shown on the ordinate (35), as a function of frequency (Hz), shown on the abscissa (36), of a clicking sound produced by a metal pin on this surface. The results show that a clicking sound on the floor panel of the revelation is less loud and that peaks in the interval from 1000 to 5000 Hz disappear. This makes it possible to achieve a warmer and more wood-like sound.

[0166] Fig. Figure 6 shows a further method for producing a coated panel 1 with the features of the invention. In this case, it is a method for producing a floor panel 1 with a substrate 2 made of synthetic material or synthetic composite material, for example, a floor panel of the LVT (Luxury Vinyl Tile) type, which comprises a substrate 2 made of highly filled soft, semi-rigid, or rigid PVC. The substrate 2 can be formed by extrusion of the synthetic material or composition or, as is the case here, in a first step T1 by one or more spreading operations in which granules 39 or powders with a suitable composition are deposited on a conveyor belt 40 and consolidated between the belts 41 of a double-belt press.In a second step T2, a printed film made of synthetic material 24 can be unrolled onto the formed substrate 2 to form the decorative layer 4, and in a third step T3, a translucent film made of synthetic material 43 can optionally be unrolled to form at least a portion 5A of the wear layer 5. In a fourth step T4, a mixture of at least one acrylate resin and a thermal initiator is applied to the resulting whole, preferably to the translucent film made of synthetic material 43, for example by means of one or more rollers 44. The substrate 2, the one or more films made of synthetic material, and the mixture of acrylate resin and the thermal initiator are then consolidated in a fifth step T5 or cured by means of a hot roller 45. In the example shown, a textured roller is used.Ultimately, the structure 32 of the roller 45 is advantageously copied in thermally curing acrylic resin. Such a process results in a wear layer 5 with excellent aesthetic and mechanical properties, without the need for an additional surface UV-cured lacquer layer, as is the case with prior art LVT floor panels.

[0167] As an alternative to the one in Fig. In the process shown in 6, the mixture of acrylate resin and a thermal initiator can also be applied to a semi-finished product, either consolidated or unconsolidated, comprising a substrate made of synthetic material or a synthetic composite and at least one decorative layer, for example, to a semi-finished product with a substrate, a printed film made of synthetic material, and optionally a transparent film made of synthetic material located above the print. The entire semi-finished product and the mixture can then be processed in a short-cycle press similar to the one described in step S4 of Fig. 3 presses shown will be pressed.

[0168] It is clear that the process shown and mentioned in the introduction can, in itself, be carried out wholly or partially on larger panels, sheets, or continuous webs. In such a case, the actual coated panels are obtained at least after the panels, sheets, or webs have been separated.

[0169] The present disclosure is by no means limited to the embodiments described above; rather, such coated panels and methods for their production can be realized without departing from the scope of protection of the present invention. Furthermore, it is also possible to apply the concept of the invention to the texturing of packaging materials or flat materials such as posters, stationery, or laminating material for laminating profiles, such as skirting boards and edge profiles for floor coverings.The disclosure therefore also relates to a method for producing packaging materials or flat materials, characterized in that the method comprises the step of applying a thermally curable acrylate resin or thermally curable unsaturated polyester to the actual packaging material or flat material, for example, paper, cardboard, film made of synthetic material, or the synthetic material itself, for example with a thermal initiator, and of at least partially curing the aforementioned acrylate resin or unsaturated polyester by means of hot pressing, preferably using a structured pressing element or a pressing film. It is clear that such a method can further demonstrate the preferred features of the invention according to the third aspect without the need to obtain coated panels.

[0170] The invention also relates to the following list of numbered points: Item 1. Coated panel with at least one substrate (2) and a top layer (3) applied thereto, wherein the aforementioned top layer (3) comprises at least one decorative layer (4) and a translucent or transparent wear layer (5), characterized in that the aforementioned wear layer (5) comprises a thermally cured acrylate resin or a thermally cured unsaturated polyester resin, where thermal curing preferably partially or completely hardens the resin. Point 2. Coated panel according to point 1, characterized in that the aforementioned acrylate resin or unsaturated polyester resin is cured by means of a thermally initiated radical crosslinking reaction. Point 3. Coated panel according to point 1 or 2, characterized in that the aforementioned curing process comprises at least one cross-linking of the double carbon bond present in the acrylate resin or unsaturated polyester resin. Point 4. Coated panel, whether according to one of the preceding points or not, comprising at least one substrate (2) and a top layer (3) applied thereto, wherein the aforementioned top layer (3) comprises at least one decorative layer (4) and a translucent or transparent wear layer (5), characterized in that the aforementioned wear layer (5) is obtained on the basis of a mixture which contains at least on the one hand acrylate resin and / or unsaturated polyester resin and on the other hand a thermal initiator. Point 5. Coated panel according to point 4, characterized in that the aforementioned thermal initiator is an organic peroxide, preferably benzoyl peroxide or lauryl peroxide or tertiary butyl peroxy-3,5,5-trimethylhexanoate (TBPIN). Point 6. Coated panel according to point 4 or 5, characterized in that the aforementioned mixture comprises 0.1-5 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin and preferably 0.1-2 parts of thermal initiator per 100 parts of acrylate resin or per 100 parts of unsaturated polyester resin. Point 7. Coated panel according to one of the preceding points, characterized in that the aforementioned wear layer (5) comprises traces of a peroxide. Point 8. Coated panel according to one of the preceding points, characterized in that the aforementioned wear layer (5) is hardened uniformly or substantially uniformly over its entire thickness. Point 9. Coated panel according to one of the preceding points, characterized in that the thermal curing comprises chemical cross-linking, preferably of the double carbon bonds present in the acrylate resin or in the unsaturated polyester resin. Point 10. Coated panel according to one of the preceding points, characterized in that the aforementioned wear layer (5) is obtained on the basis of a mixture which contains at least on the one hand acrylate resin and / or unsaturated polyester resin and on the other hand a photoinitiator, wherein preferably the mixture comprises 0.1-5 parts of a photoinitiator per 100 parts acrylate resin or per 100 parts unsaturated polyester resin. Item 11. Coated panel according to item 10, characterized in that the aforementioned mixture comprises 0.1-5 parts of two different photoinitiators per 100 parts acrylate resin or per 100 parts unsaturated polyester resin. Point 12. Coated panel according to one of the preceding points, characterized in that the aforementioned decorative layer (4) comprises a carrier sheet provided with synthetic material (19), such as a paper sheet (20). Point 13. Coated panel according to point 12, characterized in that the aforementioned synthetic material (19) comprises double carbon bonds. Item 14. Coated panel according to item 12 or 13, wherein the wear layer comprises a thermally cured acrylate resin or a thermally cured unsaturated polyester resin and wherein the aforementioned synthetic material (19) is selected from the list of amino resins, urea-formaldehyde, melamine-urea-formaldehyde, melamine-formaldehyde, polyurethane, urethane-acrylic copolymer, melamine acrylate, melamine-formaldehyde, acrylate, latex, dispersions, optionally in combination with a crosslinking agent. Item 15. Coated panel according to one of the preceding items, wherein the wear layer comprises a thermally cured acrylate resin and wherein the aforementioned acrylate resin is obtained on the basis of at least a multifunctional acrylate monomer and / or oligomer, such as a hexafunctional acrylate oligomer. Item 16. Coated panel according to one of the preceding items, wherein the wear layer comprises a thermally cured acrylate resin and wherein the aforementioned acrylate resin is obtained on the basis of at least a monofunctional or difunctional or a trifunctional acrylate monomer and / or oligomer. Item 17. Coated panel according to one of the preceding items, wherein the wear layer comprises a thermally cured acrylate resin and wherein the aforementioned acrylate resin is obtained with at least one chemically modified acrylate, such as a fluoroacrylate. Item 18. Coated panel according to any of the preceding items, wherein the wear layer comprises a thermally cured acrylate resin and wherein the aforementioned acrylate resin is of an aliphatic type. Item 19. Coated panel according to one of the preceding items, wherein the wear layer is composed of different layers; and the wear layer comprises several layers having the properties described for the wear layer in one of the preceding items 1 to 18; wherein the compositions of these several layers preferably differ from one another. Item 20. Coated panel according to item 19, wherein the top layer of the wear layer comprises one or more of a fluorinated acrylate, a microaluminum oxide, a silicone acrylate or a nanosilicon dioxide. Point 21. Coated panel according to one of the preceding points, characterized in that the coated panel (1) is a floor panel, preferably suitable for floating installation. Item 22. Coated panel according to one of the preceding items, characterized in that the coated panel (1) has a relief on its surface, optionally with gloss differences. Item 23. Method for the production of coated panels, wherein the panels (1) comprise at least a substrate (2) and a top layer (3) applied thereto, and the aforementioned top layer (3) comprises at least a decorative layer (4) and a translucent or transparent wear layer (5), characterized in that the method comprises at least the following steps: - the step (S3) of applying one or a combination of a coating composition comprising an acrylate resin, an acrylate resin or an unsaturated polyester resin, to the aforementioned decorative layer (4); wherein the coating composition, the acrylate resin or the unsaturated polyester resin optionally comprises a thermal initiator and optionally a photoinitiator; and - the step (S4) of at least partially hardening the aforementioned coating composition, acrylate resin or unsaturated polyester resin by means of hot pressing to form at least a part of the aforementioned wear layer (5). Point 24. Method according to point 23, characterized in that the method further comprises the step of post-curing the pressed wear layer (5) by means of ultraviolet and / or electron radiation, preferably under an inert atmosphere. Point 25. Method according to one of points 23 to 24, characterized in that the aforementioned pressing is carried out using a structured pressing element (31), preferably forming a relief in the top layer. Point 26. Method according to one of points 23 to 25, characterized in that the aforementioned pressing is carried out on a stack (29) comprising at least the substrate (2), the decorative layer (4) and the coating composition and / or the acrylate resin and / or the unsaturated polyester resin. Point 27. Method according to one of points 23 to 26, characterized in that the step (S3) of applying the coating composition and / or the acrylate resin and / or the unsaturated polyester resin to the aforementioned decorative layer (4) is carried out, while the decorative layer (4) is already part of a stack (29) comprising at least the substrate (2) and the decorative layer (4). Point 28. Method according to one of points 23 to 27, characterized in that the aforementioned decorative layer (4) comprises a carrier sheet, such as a paper sheet (20), and the method includes at least the step of coating the aforementioned carrier sheet with synthetic material (19). Point 29. Method according to point 28, characterized in that the step of providing the aforementioned carrier sheet with synthetic material (19) comprises at least the application of a water-based or a water-based UV-curable synthetic material to the aforementioned carrier sheet. Point 30. Method according to point 28 or 29, characterized in that the step of providing the aforementioned carrier sheet with synthetic material (19) comprises at least the application of a UV-curable substance, wherein this substance further comprises a thermal initiator. Item 31. Method according to any of items 23 to 30, wherein the method comprises step (S3) of applying the coating composition to the aforementioned decorative layer (4); wherein the coating composition comprises at least an acrylate resin, one or more components comprising free hydroxyl groups, one or more components comprising free isocyanate groups, optionally one or more thermal initiators, optionally photoinitiators and optionally one or more crosslinking agents. Item 32. Method according to item 31, wherein the coating composition comprises a hydroxy-functional acrylate and / or a hydroxy-functional urethane acrylate. Item 33. Method according to one of items 31 or 32, wherein the coating composition comprises an isocyanate polymer and / or an isocyanate-functional acrylate. Point 34. Method according to one of points 31 to 33, wherein, during the aforementioned hot pressing, a condensation reaction occurs between hydroxyl and isocyanate groups of the coating composition, thereby causing crosslinking in the coating composition. Item 35. Method according to any one of items 23 to 34; wherein, after step (S3) of applying the coating composition, the acrylate resin or the unsaturated polyester resin to the aforementioned decorative layer (4); and before step (S4) of at least partially curing the aforementioned coating composition, the acrylate resin or the unsaturated polyester resin by hot pressing in order to form at least a part of the aforementioned wear layer (5); the method comprises the step of removing water and / or solvent from the coating composition or from the acrylate resin or from the unsaturated polyester resin. Item 36. Method according to any of items 23 to 35, wherein after step (S3) of applying the coating composition, the acrylate resin or the unsaturated polyester resin to the aforementioned decorative layer (4); and before step (S4) of at least partially curing the aforementioned coating composition, the acrylate resin or the unsaturated polyester resin by hot pressing in order to form at least a part of the aforementioned wear layer (5); the method comprises the step of gelling the coating composition, the acrylate resin or the unsaturated polyester resin to a non-viscous state. Point 37. Method according to one of points 23 to 36, wherein after hot pressing the step of UV post-curing of the pressed wear layer - preferably under an inert atmosphere - is carried out, whereby cross-linking of double bonds takes place; for this purpose the coating composition, the acrylate resin or the unsaturated polyester resin preferably comprises photoinitiators. Point 38. Method according to one of points 23 to 37, wherein after hot pressing the step of thermal post-curing of the pressed wear layer is carried out, whereby cross-linking of double bonds takes place; for this purpose the coating composition, the acrylate resin or the unsaturated polyester resin preferably comprises thermal initiators. Point 39. Method according to point 38, wherein the thermal post-curing after hot pressing is carried out at a higher temperature than during hot pressing. Item 40. Method according to any one of items 23 to 39, wherein prior to step (S3) of applying the coating composition, the acrylate resin or the unsaturated polyester resin to the aforementioned decorative layer (4); the method comprises the step of applying an adhesion promoter to the aforementioned decorative layer, wherein the adhesion promoter preferably comprises or consists of one or more polyurethanes, polyurethane dispersions, water-based polyurethane dispersions, polyurethane dispersions with acrylate functionality, melamine acrylate or acrylate primers, preferably a reactive low-viscosity acrylate primer. Point 41. Method according to one of points 23 to 40, wherein in step (S3) of applying the or a combination of the coating composition, the acrylate resin or the unsaturated polyester resin to the aforementioned decorative layer (4) such application is carried out by a wet or dry process. Item 42. Method according to any of items 23 to 41, wherein the method comprises step (S3) of applying the coating composition to the aforementioned decorative layer (4); and wherein the coating composition comprises a solvent, for example butyl acetate. Point 43. Method according to one of points 23 to 42, characterized in that the pressing is carried out using a short-cycle press (30). Point 44. Method according to one of points 23 to 43, characterized in that the pressing is carried out by means of a continuous type press or by means of a hot press roller. Point 45. Method according to point 44; wherein the method comprises the step of applying the decorative layer to the substrate by rolling the decorative layer from a roll, wherein the aforementioned decorative layer is preferably a film of synthetic material or a printed film of synthetic material or a printed sheet of paper - and is preferably impregnated with a thermally curing resin; wherein the coating composition is preferably applied to the decorative layer by a dry process by rolling a roller. Point 46. Method according to any of the preceding points 23 to 45, wherein after hot pressing a relief is pressed into the wear layer and wherein after pressing in the relief the wear layer is thermally cured or cured by means of UV radiation. Point 47. Method according to one of points 23 or 46, characterized in that the hot pressing is carried out at a temperature of 120 to 220 °C and / or at a pressure of 10 to 80 bar. Point 48. Method according to any one of points 23 to 47, wherein the substrate comprises a thermoplastic material - preferably PVC, polypropylene or polyethylene - preferably filled with fillers; and wherein the decorative layer comprises a film of synthetic material - preferably printed - and preferably a PVC film; or wherein the decorative layer comprises or consists of a print on the substrate. Point 49. Method according to any one of points 23 to 47, wherein the substrate comprises or consists of a wood fiberboard (such as MDF or HDF) and the decorative layer comprises a printed carrier sheet, preferably a printed paper sheet, and preferably a printed paper sheet impregnated with a thermally curing resin. Item 50. Coated panel with at least one substrate (2) and a top layer (3) applied thereto, wherein the aforementioned top layer (3) comprises at least one decorative layer (4) and a translucent or transparent wear layer (5), characterized in that the aforementioned wear layer (5) comprises an acrylate, wherein this acrylate comprises covalent bonds formed by reaction of hydroxyl groups with isocyanate groups. Item 51. Coated panel according to item 50, wherein an adhesion promoter is located between the decorative layer and the wear layer, wherein the adhesion promoter preferably comprises or consists of one or more: a polyurethane, a polyurethane dispersion, a water-based polyurethane dispersion, a polyurethane dispersion with acrylate functionality, a melamine acrylate or a - preferably reactive - low-viscosity acrylate primer. Item 52. Coated panel according to one of items 50 to 51, wherein the wear layer comprises a relief, wherein preferably this relief exhibits gloss differences. Item 53. Coated panel according to item 52, wherein the decorative layer shows a wood pattern by printing and wherein the relief is in exact match with the wood pattern, wherein the aforementioned relief preferably shows gloss differences in exact match with the wood pattern. Item 54. Coated panel according to any one of items 50 to 53, wherein the substrate comprises a thermoplastic material - for example, polyvinyl chloride, polyethylene or polypropylene -, wherein this thermoplastic material preferably comprises one or more fillers -; and wherein the decorative layer comprises a film of synthetic material or a printed film of synthetic material or wherein the decorative layer comprises a print on the substrate. Item 55. Coated panel according to any one of items 50 to 53, wherein the substrate comprises or consists of a wood fiberboard (such as MDF or HDF) and the decorative layer comprises a printed carrier sheet, preferably a printed paper sheet, and preferably a printed paper sheet impregnated with a thermally curing resin. Item 56. Method according to one of points 23 to 49, wherein the method is used for the production of panels (1) having the characteristics of one of points 1 to 22 or one of points 50 to 55. Item 57. Coated panel with at least one substrate (2) and a top layer (3) applied thereto, wherein the aforementioned top layer (3) comprises at least one decorative layer (4), characterized in that a thermally cured acrylate resin or a thermally cured unsaturated polyester resin is located between the aforementioned decorative layer (4) and the substrate (2) and / or the decorative layer (4) is formed at least partially by a thermally cured acrylate resin or a thermally cured unsaturated polyester resin. Item 58. Coated panel according to item 57, characterized in that the thermally cured acrylate resin or thermally cured unsaturated polyester resin is configured to be colored, for example by comprising pigments such as titanium oxide. Item 59. Coated panel according to item 57 or 58, characterized in that thermally cured acrylate resin or thermally cured unsaturated polyester resin forms a base layer for a print configured thereon, which at least partially forms the aforementioned decorative layer. Point 60. Coated panel according to one of points 57 to 59, characterized in that the aforementioned decorative layer relates to a veneer, wherein thermally cured acrylate resin or thermally cured unsaturated polyester preferably extends from the underside of the veneer into and / or through pores, cracks and other openings present in the veneer. Point 61. Coated panel according to one of points 57 to 60, characterized in that the aforementioned decorative layer comprises at least one carrier sheet, such as a paper sheet (20), wherein thermally cured acrylate resin or thermally cured polyester resin forms the bond between the aforementioned carrier sheet and the substrate (2). Item 62. Coated panel or method according to any of the preceding items, characterized in that the substrate (2) is a wood fiberboard with an average density of less than 850 kg per cubic meter and preferably less than 750 kg per cubic meter. Item 63. Coated panel or method according to any of the preceding items, characterized in that the aforementioned top layer (3) comprises a water-impermeable layer. Point 64. Coated panel or method according to point 63, characterized in that the aforementioned water-impermeable layer is formed by a layer that is present between the aforementioned decorative layer (4) and the substrate (2). Point 65. Coated panel or method according to point 63, characterized in that the aforementioned waterproof layer is formed by an ink layer which forms at least part of the aforementioned decorative layer (4). QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 97 / 47834 [0002, 0134] WO 03 / 016655

[0003] WO 2010 / 088769

[0003] WO 2009 / 101217

[0003] WO 2010 / 070474 [0003, 0004] WO 01 / 47726 [0005, 0007] EP 2019735

[0007] WO 2009 / 043910

[0070] WO 2014 / 024100

[0129] US 5,820,937

[0131]

Claims

[1] Coated paper sheet, wherein the coated paper sheet comprises a paper sheet and a partially hardened acrylate coating layer; wherein the partially hardened acrylate coating layer comprises at least one thermal initiator. [2] Coated paper sheet according to claim 1, characterized by , that the sheet of paper is a printed sheet of paper. [3] Coated paper sheet according to any of the preceding claims, characterized by , that the partially cured acrylate coating layer includes more than one thermal initiator. [4] Coated paper sheet according to any of the preceding claims, characterized by , that the partially hardened acrylate coating layer can be hardened by a thermally initiated radical crosslinking reaction of acrylate groups. [5] Coated paper sheet according to any one of the preceding claims, characterized bythat the paper sheet comprises an adhesion promoter on which the partially cured acrylate coating layer is provided, wherein the adhesion promoter preferably comprises or consists of one or more polyurethanes, polyurethane dispersions, water-based polyurethane dispersions, polyurethane dispersions with acrylate functionality, melamine acrylates or a - preferably reactive - low-viscosity acrylate primer. [6] Coated paper sheet according to any one of the preceding claims, characterized by , that the partially hardened acrylate coating layer has a mass between 10 and 300 grams per square meter. [7] Coated paper according to any of the preceding claims, characterized by , that the partially hardened acrylate coating layer is of the aliphatic type. [8] Coated paper sheet according to any one of the preceding claims, characterized by, that the partially cured acrylate coating layer comprises one or more than one thermal initiator, wherein the one or more than one thermal initiator is selected from a persulfate, a peroxydiphosphate, an azo polymerization initiator, an organic peroxide - preferably selected from benzoyl peroxide, a methyl benzoyl peroxide, TPBIN (tertiary butyl peroxy-3,5,5-trimethylhexanoate), lauryl peroxide, 2-butanone peroxide, ketone peroxide, diacyl peroxide, peroxyketal, hydroperoxide, peroxydicarbonate, peroxymonocarbonate, tert-butyl peroxy-3,5,5-trimethylhexanoate (TPBIN). [9] Coated paper sheet according to any one of the preceding claims, characterized by, that the partially cured acrylate coating layer has been partially cured by UV curing of an acrylate resin comprising at least one acrylate monomer, one acrylate oligomer and at least one photoinitiator, wherein the acrylate resin preferably comprises a multifunctional acrylate or methacrylate monomer and / or oligomer, such as a hexafunctional acrylate oligomer. [10] Coated paper sheet according to any of the preceding claims, characterized by that the partially cured acrylate coating layer comprises DPGDA (dipropylene glycol diacrylate) and / or a trifunctional monomer, such as TMPTA, or reaction products thereof. [11] Coated paper sheet according to any of the preceding claims, characterized by that the partially cured acrylate coating layer is obtained from at least one urethane acrylate, e.g. at least one hydroxyl-functional urethane acrylate. [12] Coated paper sheet according to any one of the preceding claims, characterized by , that the paper sheet is provided with synthetic material (19), wherein the synthetic material (19) is preferably selected from the list of amino resins, urea formaldehyde, melamine-urea-formaldehyde, melamine-formaldehyde, polyurethane, urethane-acrylic copolymer, melamine acrylate, melamine-formaldehyde, acrylate, latex, dispersions, optionally in combination with a crosslinking agent. [13] Coated paper sheet according to any of the preceding claims, characterized by , that the partially cured acrylate coating layer comprises several layers, the composition of which differs from each other.

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