Decorative panel and method for manufacturing a decorative panel

Abstract

Method for manufacturing a decorative panel, comprising the steps of: providing a substrate material (1), providing at least a decorative layer (2) and a wear layer (3) onto said substrate material (1), wherein said wear layer (3) is located above said decorative layer (2), providing a curable lacquer (4) on said wear layer (3), and embossing at least said curable lacquer (4), wherein the thickness of said wear layer and the thickness of said curable lacquer (4) follow a ratio of between 5:1 and 1:25.

Description

[0001] DECORATIVE PANEL AND METHOD FOR MANUFACTURING A DECORATIVE PANEL

[0002] The present invention relates to a decorative panel and a method for manufacturing a decorative panel.

[0003] In particular, the invention relates to decorative panels, for which laminate floor panels, parquet floor panels, and floor panels based on synthetic material are known examples. More in particular, in the class of floor panels which are based on synthetic material, LVT, WPC, and SPC floor panels are known examples. These floor panels mostly have a thermoplastic substrate, which, apart from the thermoplastic synthetic material, may also comprise additives and / or fillers. The top layer of these floor panels mostly also is composed of one or more thermoplastic layers. Reference is made to document WO 2013 / 026559 for an exemplary composition of such product.

[0004] Similarly to laminate floor panels, it is the intention that these synthetic material-based floor panels comprise an upper surface reflecting a natural character. To this aim, use is generally made of a decor and an embossed wear layer, by which a relief is realized in the upper surface of the floor panel. Again, reference is made to document WO 2013 / 026559, in which such example is described. However, with synthetic material-based floor panels, obtaining a natural look and feel may be problematic. This is especially so because of the type of wear layer that is mostly applied, namely a thermoplastic wear layer. Not only is this wear layer mostly scoring unsatisfactorily in respect to features such as wear resistance, scratch resistance, stain resistance and the like. Moreover, it also gives a plastic-like appearance to the floor panels, which is caused by the highly glossy character thereof. In order to address these problems, it is known to provide a lacquer layer above or on the wear layer. However, the known techniques thereof have proven insufficient, certainly in the case that the upper surface of the floor panel has a relief.

[0005] In the document WO 2013 / 026559, it is described to apply a lacquer layer on an embossed or deformed wear layer. However, the inventor has found that with this technique there is a high risk that glossy spots are visible in the upper surface of the floor panel. These spots are annoying and give an unnatural appearance to the floor panel. The problem seems to rise in particular with deep relief.

[0006] Document EP 2 883 712 describes providing two lacquer layers on a wear layer, with the aim of creating a difference in gloss degree. Although thereby the artificial look of the wear layer can be addressed, purely applying two lacquer layers seems not sufficient for removing the risk of glossy spots.

[0007] In document US 6,746,756 it is described to provide a lacquer layer on a wear layer and then embossing the lacquer layer in order to form a relief. Contrary to the above- mentioned document WO 2013 / 026559, the lacquer layer as such is embossed. There however remains a risk that the superficial lacquer layer of US 6,746,756 may get disrupted or interrupted, thereby making the underlaying wear layer visible. This would again lead to visibility of unwanted glossy spots. Furthermore, with the superficial lacquer layer of US 6,746,756 it is still difficult to obtain a decorative panel with a good score in respect to features such as wear resistance, scratch resistance, stain resistance and the like. Furthermore, by combining a wear layer and a lacquer layer as described in any of the aforementioned documents, the underlaying decorative layer may not be optimally visible. In particular, due to the combined wear layer and lacquer layer, the visual appearance of the decorative layer may be somewhat faded, or a certain haze may be visible, such that the decorative panel does not have a natural appearance.

[0008] WO 2024 / 009238 discloses a decorative panel comprising a wear layer and an applied thereon cured lacquer layer, wherein the cured lacquer layer has a thickness that is more comparable or even larger than the thickness of the wear layer. A relief can be provided in said cured lacquer layer. In so doing a more natural visual appearance and an improved surface quality can be obtained.

[0009] The present invention is, in first instance, aiming at an alternative method for manufacturing decorative panels, wherein, in accordance with preferred embodiments a more practicable industrial process for manufacturing decorative panels having a more natural visual appearance and / or surface quality may be obtained, especially regarding scratch and / or wear resistance.

[0010] A first independent aspect of the present invention provides a method for manufacturing a decorative panel, comprising at least the following steps:

[0011] - the step of providing a substrate material, wherein said substrate material preferably comprises one or more layers with thermoplastic material;

[0012] - the step of providing at least a decorative layer and a curable lacquer layer onto said substrate material, wherein said curable lacquer layer is located above said decorative layer and wherein said lacquer layer is preferably at least in part curable by means of heat, and

[0013] - the step of embossing at least said curable lacquer layer using a press treatment, with as a characteristic that said curable lacquer layer is provided, more particularly adhered, onto said substrate material and / or at least partially cured in said press treatment, wherein said curable lacquer layer in said press treatment is heated to a temperature of 50°C or more, 75°C or more, preferably 100°C or above.

[0014] The present invention hence is characterized in providing said curable lacquer onto said substrate material in said press treatment and processing said curable lacquer layer in said press treatment at a temperature of 50°C or more, 75°C or more, 100°C or above; and / or at least partially curing said curable lacquer layer in said press treatment while being processed at a temperature of 50°C or more, 75°C or more, 100°C or above. In the latter case the curable lacquer layer may be provided or adhered to said substrate material prior to, subsequent to or in said press treatment.

[0015] It is clear that said press treatment may use a structured mechanical press element, for example an embossing roller or a structured press plate, wherein the structure of the structured mechanical press element is pressed and negatively copied into said curable lacquer layer. Preferably said temperature is such that a total curing, or at least a 85% curing, is obtained in said press treatment. The degree of curing is preferably measured in accordance with ISO 4216:2021.

[0016] High temperature embossing, adhering and / or at least partially curing, of the curable lacquer layer using a single press treatment leads to a more fluent manufacturing.

[0017] Preferably, said curable lacquer layer is actively cooled or at least shielded from heat prior to entering said press treatment. This may prevent a premature curing reaction.

[0018] Preferably, the temperature of said curable lacquer layer is maintained below 60°C, or below 40°C prior to entering said press treatment.

[0019] Preferably, the curable lacquer layer shows a curing degree below 50%, or below 30% upon entering said press treatment.

[0020] When said substrate material comprises one or more layers with thermoplastic material, the substrate material may weaken due to the high temperature embossing and adhering and / or curing. In such case, it is preferred that the high temperature embossing and adhering and / or curing is followed by a cooling treatment. Such cooling treatment may be obtained in the same press, subsequently to the heated press treatment, or may be carried out separately, preferably immediately, i.e. starting within 5 seconds, after said press treatment.

[0021] For the press treatment, there are in essence two basic possibilities.

[0022] In accordance with a first possibility, said embossing and adhering and / or curing takes place continuously on the same line by which the substrate material, or one or more layers thereof, is provided at an upstream location. For example, an extrusion line may be provided for extrusion of substrate material through a slot nozzle die, wherein a device, for example a roller, for executing said press treatment is provided downstream of said slot nozzle die. The temperature of 100°C or more in said press treatment allows obtaining a satisfactory result even if the contact time with the device, for example with a structured mechanical press element, is limited, for example less than 20 seconds, or less than 10 seconds. As mentioned, preferably a roller is used in the press treatment, for example an embossing roller, and, preferably the curable lacquer layer, preferably at least together with said substrate material, is following said embossing roller over a surface that corresponds to at least 25%, or at least 35%, of the circumference of said embossing roller, or that corresponds to an angular section of at least 20°, or at least 45°, or an angular section between 65° and 90°. An optional cooling treatment may be obtained inline as well, preferably directly downstream from the embossing roller for example by means of convective or conductive heat transfer. Convective heat transfer may for example be obtained by blowing cooled air over the halfproduct containing the substrate material and the cured lacquer layer. Conductive heat transfer may for example be obtained by contacting the halfproduct with a cooled surface. Preferably, the halfproduct is supported upon leaving the device, for example the embossing roller. In so doing the risk that the potentially weakened thermoplastic material of the substrate material gives rise to warping can be minimized. The support function can be attained by means of said cooled surface, wherein this cooled surface is preferably positioned below the halfproduct and contacts said halfproduct.

[0023] In accordance with a second possibility, said embossing and adhering and / or curing takes place separately, i.e. off line from the line in which said substrate material, or one or more layers thereof, is provided. For example, an extrusion line may be provided for extrusion of substrate material through a slot nozzle die. The substrate material may be divided in slabs and the press treatment may be executed on said slabs, for example in a discontinuous press, such as in a single or multi daylight press. The temperature of 100°C or more in said press treatment allows obtaining a satisfactory result even if the heated cycle of the press is below 30 minutes, or even below 10 minutes. An optional cooling cycle may be performed, preferably in the same press. The cooling cycle may be performed during 35 minutes or less, and be aimed at bringing the slabs to room temperature, i.e. below 30°C. In so doing the risk that the potentially weakened thermoplastic material of the substrate material during the heated cycle gives rise to warping can be minimized. No supporting function will be required for removing the halfproducts from the press after such cooling cycle, but may nevertheless be provided. According to a particularly preferred embodiment, said curable lacquer layer is provided on a transparent wear layer, wherein the thickness of said wear layer and the thickness of said curable lacquer layer follow a ratio of between 5: 1 and 1 :25, or between 1 :2 and 1 : 10.

[0024] Preferably, said transparent wear layer, when available, is a prefabricated thermoplastic foil, e.g. a foil of polyvinyl chloride (PVC). The PVC of the wear layer may be plasticized or not. Preferably the wear layer is free of plasticizer or comprises an amount of plasticizer of 5 phr or less. In such case a very firm final wear protection is obtained over the decorative layer. According to an alternative the PVC of the wear layer comprises at least 15 phr of plasticizer, or, at least 25 phr of plasticizer or more. In such case a sound attenuating effect may be obtained rather close to the surface of the decorative panel. This is of special importance in case the decorative panel is a floor panel. It is of course not excluded that plasticizer levels between 5 and 15 phr are practiced, in which case an optimum balance between final wear resistance and sound attenuation may be obtained. According to an alternative, said wear layer is liquidly applied and is e.g. a UV curable or UV cured hotmelt. Such embodiment is of special interest when said decorative layer is obtained by applying inks directly on said substrate material, potentially with the intermediate of one or more primer layers.

[0025] Preferably said wear layer, when available, has a thickness of at least 50 micrometer, or at least 100 micrometer or more. A good value for the thickness of the wear layer is about 100 micrometer. As mentioned in said particularly preferred embodiment, the curable lacquer layer has a thickness of at least one fifth of said thickness. In the case of a wear layer of about 100 micrometer, a curable lacquer of 100 or more, or even of 150 micrometer or more may be applied on said wear layer.

[0026] It is clear that said wear layer, when available, is preferably transparent or translucent.

[0027] The same is true for said curable lacquer when in finally cured condition. The invention in accordance with said particularly preferred embodiment may have one or more advantages over what is known in that by following the above-mentioned ratio, a thinner wear layer may be applied. Using a thinner wear layer may have the advantage that transparency is improved, thus making the decorative layer underneath better visible at the surface of the decorative panel. Furthermore, by combining a wear layer and a curable lacquer following the above-mentioned ratio, at least the same scratch and / or wear resistance, or an even improved scratch and / or wear resistance, may be obtained in comparison to wear layers which are known in the art. By embossing at least the substantially thick curable lacquer, the risk may furthermore be reduced of having uncoated spots on the surface of the decorative panel, and gloss of the surface of the decorative panel may be determined by the curable lacquer layer and / or by the embossment structure. As such, the particularly preferred embodiment of the present invention allows for providing a decorative panel with improved visual appearance and / or with improved scratch and / or wear resistance.

[0028] By preference, the thickness of said wear layer, when available, and the thickness of said curable lacquer follow a ratio of between 4: 1 and 1 :20, more by preference of between 3: 1 and 1 :15, even more by preference of between 2: 1 and 1 : 10, most by preference of between 1 :1 and 1 : 10. With increased preferability, the transparency is further improved while still maintaining at least the same scratch and / or wear resistance, or while even improving the scratch and / or wear resistance.

[0029] For providing said curable lacquer on said wear layer several possibilities are envisaged, of which here below four are described without desiring to be exhaustive.

[0030] According to a first possibility, said curable lacquer is provided partially, at least partially, or wholly onto said wear layer before the step of providing at least said decorative layer and said wear layer onto said substrate material. This may allow a more easy application of the curable lacquer on the wear layer and / or may allow that the thickness ratio of the curable lacquer with regard to the wear layer can be set more accurately. By applying the curable lacquer before the step of providing at least the decorative layer and the wear layer onto the substrate material, the combined curable lacquer and wear layer may be prepared offline and / or may be prepared in advance, which may simplify the manufacturing process and / or improve its efficiency.

[0031] According to a second possibility, said curable lacquer is provided onto said wear layer by means of a transfer film containing said curable lacquer. The transfer film is preferably a temporary carrier for the curable lacquer which may be disposed of after the transfer of said curable lacquer to said wear layer. According to a special embodiment the transfer film may remain as e.g. a topmost layer in the obtained decorative panels, wherein such transfer film may serve as a protective packaging aid which is to be removed for example upon installation of the decorative panel. Applying the curable lacquer by means of a transfer film may allow to set the thickness of the curable lacquer accurately and / or may allow that the transfer film containing the curable lacquer is prepared beforehand and / or offline. By preference, the curable lacquer may be at least partly precured onto the transfer film prior to applying it onto the wear layer. In such case the coating is preferably at least a radiation curable lacquer, such as a UV curable lacquer, and is cured preferably by means of radiation, such as UV curing.

[0032] According to a third possibility, said curable lacquer is provided onto said wear layer during the step of embossing said curable lacquer. By directly applying the curable lacquer during embossing, the curable lacquer may be applied in an uncured state, thereby minimizing the risk of cracking due to embossing in a partly precured lacquer.

[0033] According to a fourth possibility, said curable lacquer is provided onto said wear layer between the step of providing at least said decorative layer and said wear layer onto said substrate material, and the step of embossing and at least partially curing said curable lacquer. By providing the curable lacquer onto said wear layer between the step of providing at least said decorative layer and said wear layer onto said substrate and the step of embossing, adherence between the several layers may be improved. More in particular, by having a separate lamination step of the decorative layer and the wear layers onto the substrate material, subsequently providing the curable lacquer onto said wear layer, and subsequently embossing and at least partially curing said curable lacquer, adherence between the several layers may be improved. Preferably, said curable lacquer has a thickness on said wear layer of between 10 and 800 pm, even more preferably between 50 and 300 pm. Within said thickness range, the curable lacquer has sufficient thickness to provide improved scratch and / or wear resistance, while still allowing optimal transparency of the combined curable lacquer and wear layer.

[0034] Preferably, said step of embossing said curable lacquer is executed with said lacquer in uncured or semi-cured, i.e. precured, condition. The lacquer may be fully cured by means of the press treatment of the invention, i.e. during embossing and adhering. Alternatively, one or more further curing steps may be necessary to reach the finally cured condition of said curable lacquer subsequent to said embossing.

[0035] Preferably, said curable lacquer is at least thermally curable. Additionally said curable lacquer may be radiation curable, for example excimer curable and / or UV curable and / or an LED curable, in particular UV LED curable. Thermally curable lacquers are easy to apply in their non-cured state, while forming a solid layer having good scratch and / or wear resistance once cured. Furthermore, curing by means of heat, excimer and / or UV is easy to implement in an existing production line and offers a lot of flexibility. In particular, the curable lacquer may be at least partly cured immediately after application, and preferably before said embossing, or may be wholly or finally cured before, during and / or after embossing. It is noted that a partial or final curing of a thermally curable lacquer during embossing can be obtained in several manners. In the case of an at least thermally curable lacquer the curing can be obtained by embossing at said temperature obtained with the press treatment of the invention.

[0036] By preference, said curable lacquer is a two-stage curable lacquer, one stage being thermally curable, another stage being radiation, e.g. excimer and / or UV, curable. This has the particular advantage that the curable lacquer may be applied in its uncured form allowing easy application, may be partly precured before and / or during embossing thereby improving the embossment quality, and / or may be cured in its second stage during and / or immediately after embossing. This may not only allow improving efficiency of the manufacturing process, but may also improve the quality of the relief obtained by embossing, as well as the scratch and / or wear resistance of the finally cured lacquer.

[0037] According to a further or another embodiment, said curable lacquer is partly, at least partly or wholly cured, for example precured, onto said wear layer before the step of providing at least said decorative layer and said wear layer onto said substrate material, or before the step of embossing said curable lacquer. By precuring said curable lacquer before the step of providing at least said decorative layer and said wear layer onto the substrate material, the combination of the curable lacquer and the wear layer is conditioned to allow offline storage, for example on a roll. This may further simplify the manufacturing process and / or improve efficiency thereof. By precuring said curable lacquer before the step of embossing said curable lacquer, the quality of the structure and / or relief obtained during embossing may furthermore be of improved quality and / or may be visually enhanced. Preferably said precuring attains a degree of curing of above 10%, but preferably 30% or below.

[0038] In some embodiments, said curable lacquer is at least partly precured prior to said step of embossing by means of UV curing. In some embodiments, said curable lacquer is at least partly cured during said step of embossing. By varying the curing before, during and / or after embossing, different visual effects may be obtained.

[0039] According to a further or another embodiment, said curable lacquer comprises two or more lacquer layers, said lacquer layers preferably having a different gloss degree.

[0040] According to a further or another embodiment, said wear layer is provided with a primer, preferably a thermoplastic primer or a polyurethane dispersion primer, in between said wear layer and said curable lacquer. Preferably, said primer is available in 1.5 to 15 grams per square meter dry weight, or preferably 5 to 10 grams per square meter dry weight. The primer may allow better adhesion of the curable lacquer onto the wear layer and / or may further improve the scratch and / or wear resistance of the combined wear layer, thermoplastic primer and curable lacquer. An example of a suitable thermoplastic primer is a primer comprising PVAc (Polyvinyl Acetate), for example applied to the wear layer at about 8 grams per square meter dry weight. An example of a suitable polyurethane dispersion primer is a UV curable polyurethane dispersion comprising acrylate functionalities, for example applied to the wear layer at 5 to 10 grams per square meter dry weight. A further advantage of applying a primer mainly applies when the relief obtained by embossing is substantially deep, for example with a relief comprising embossment with a depth of at least 200 pm, or of 300 pm and deeper. The relief obtained by embossing may be only present in the curable lacquer, or may even extend to below the curable lacquer, thereby partly perforating the curable lacquer. In the latter case, the primer may penetrate through such perforations out onto the surface of the decorative panel, which may allow specific visual effects and / or may further improve the scratch and / or wear resistance.

[0041] In some embodiments, said step of providing at least said decorative layer and said curable lacquer layer onto said substrate material, and the step of embossing said curable lacquer is performed at the same time. By performing said steps at the same time, no separate lamination roller is needed, which may further simplify the manufacturing process. The decorative layer and the curable lacquer layer may be laminated together, or not, before being applied to said substrate material. Preferably, the decorative layer the curable lacquer layer, and the optional wear layer, are laminated on said substrate material by means of an embossing roller. It is preferred that the decorative layer, the wear layer, the applied thereon curable lacquer and / or the substrate material follow the contour of the embossing roller over a portion of the circumference thereof that corresponds to an angular section of at least 20°, or at least 45°, or an angular section between 65° and 90°. With such embodiment a good lamination may be obtained in combination with a high resolution in embossing.

[0042] As explained directly above, said step of providing at least said decorative layer, said lacquer layer and said optional wear layer onto said substate material, and the step of embossing said curable lacquer on said wear layer may be performed by means of a single lamination / embossing roller. The manufacturing line may thus be further simplified. According to a further or another embodiment, said curable lacquer is provided onto said wear layer by means of a roller coater, such as by means of a lick roller, a comma bar coater or a meyer bar coater. Alternatively, said curable lacquer may be provided onto said wear layer by means of a curtain coater or a slot coater. Applying the curable lacquer by means of a roller coater, a curtain coater or a slot coater allows that the thickness of the curable lacquer may be set more accurately. It is clear that the application techniques mentioned here may be applied in said first possibility, as well as in said second possibility for applying said curable lacquer.

[0043] From the above, it is clear that said curable lacquer layer may form part of a prefabricated sheet together with said optional transparent wear layer and / or said decorative layer. Said decorative layer may essentially consist or consist of inks forming the bottom of said prefabricated sheet, preferably applied to the bottom of said optional transparent wear layer, when available in said prefabricated sheet. Alternatively, said decorative layer is a printed paper sheet or a printed thermoplastic foil, wherein said prefabricated sheet comprises said curable lacquer layer applied to said decorative layer.

[0044] Here below three important examples of such prefabricated sheet are further elucidated, without desiring to be exhaustive.

[0045] According to a first example the prefabricated sheet comprises a transparent or translucent thermoplastic foil, for example a PVC foil, preferably with a plasticizer content of at least 20 phr, for example of 30 phr or more, or alternatively below 20 phr, for example of 5 phr or lower. The thermoplastic foil preferably has a thickness between 50 and 150 micrometer. On top of said PVC foil a heat and radiation curable lacquer layer is applied, for example at a rate of 50 to 200 grams per square meter. Preferably the lacquer layer is realized on the basis of a polyurethane dispersion and / or an acrylate dispersion. Preferably the lacquer layer comprises solid particles of for example aluminum oxide or silicon carbide. Preferably said curable lacquer layer has been cured by means of radiation, but allows for a further curing by means of heat, for example because it contains thermo-initiators. The curing by means of radiation may provide for a reduced tackiness of the prefabricated sheet, while the remaining ability to cure using heat may be exploited during said embossing and adhering.

[0046] According to a second example, the prefabricated sheet of said first example further comprises a decorative layer at a bottom thereof. For example a decorative layer that essentially consists of inks applied to the bottom of said transparent thermoplastic foil.

[0047] According to a third example, the prefabricated sheet comprises a decorative layer, wherein said decorative layer is a paper layer provided with an ink pattern. On top of said printed pattern a heat and radiation curable lacquer layer is applied, for example at a rate of 50 to 200 grams per square meter. Preferably the lacquer layer is realized on the basis of a polyurethane dispersion and / or an acrylate dispersion. Preferably the lacquer layer comprises solid particles of for example aluminum oxide or silicon carbide. Preferably said curable lacquer layer has been cured by means of radiation, but allows for a further curing by means of heat, for example because it contains thermo-initiators. The curing by means of radiation may provide for a reduced tackiness of the prefabricated sheet, while the remaining ability to cure using heat may be exploited during said embossing and adhering.

[0048] Preferably, in said third example, said paper layer is a base print paper, for example having a paper weight of 50 to 250 grams per square meter, more preferably between 65 and 100 grams per square meter, wherein a paper weight of about 70 grams per square meter is preferred. In case of an ink pattern obtained by means of digital printing, in particular when using water-based inks, preferably an inkjet receiver coating is applied on the surface to be printed, for example an inkjet receiver coating comprising at least a binder, such as PVA (polyvinyl alcohol), or at least absorptive particles, such as silica particles. For example, such inkjet receiver coating composition as disclosed in WO 2021 / 214559 or WO 2017 / 130117, both incorporated herein by reference, may be applied.

[0049] Preferably, in said third example, said paper layer, in particular said base paper layer, is impregnated with a thermosetting resin, for example with a melamine and / or acrylic resin. Preferably a mixture of a melamine formaldehyde resin and an acrylic resin is applied. Such impregnation of the paper layer is beneficial for adhesion with said curable lacquer layer, especially when such curable lacquer layer is or comprises an acrylate resin or an unsaturated polyester resin. According to a preferred embodiment, a primer may be additionally provided on the bottom and / or on the top surface of the impregnated paper layer. Such primer may lead to an increased adhesion with a substrate material or another adjacent layer. The primer may comprise or be a thermoplastic primer or a polyurethane dispersion primer, preferably with acrylic functionalities. Preferably, said primer is available in 1.5 to 15 grams per square meter dry weight, or preferably 5 to 10 grams per square meter dry weight. An example of a suitable thermoplastic primer is a primer comprising PVAc (Polyvinyl Acetate). An example of a suitable polyurethane dispersion primer is a UV curable polyurethane dispersion comprising acrylate functionalities, for example applied to the wear layer at 5 to 10 grams per square meter dry weight.

[0050] In accordance with the invention, and especially in connection to said third possibility of applying said curable coating, by preference, said curable lacquer has a thickness on said wear layer of between 10 and 200 pm, or even more preferably between 10 and 100 pm. Such thickness may allow sufficient scratch and / or wear resistance while obtaining good transparency of the combined curable lacquer and wear layer. Herein, alternatively by preference, said curable lacquer may have a thickness on said wear layer of between 200 and 800 pm, between 300 and 800 pm, or between 500 and 800 pm. This is particularly advantageous in case substantially deep embossment structures are desired, for example with a relief comprising embossments with a depth of at least 200pm, or of 300pm and deeper. In general, but in the case of the third possibility particularly, by applying the curable lacquer in an uncured state, the risk of cracking due to embossing in a partly precured lacquer is minimized. It may however be possible that the curable lacquer is partly cured before embossing.

[0051] According to some embodiments, said curable lacquer is colored and / or stained. By using a colored and / or stained curable lacquer, a visual effect may be obtained wherein preferably certain coloring corresponds with the relief obtained by embossing. According to some embodiments, said curable lacquer, before providing it onto said wear layer, is applied onto an embossing roller used during the step of embossing said curable lacquer. By directly applying the curable lacquer on the embossing roller, the lacquer can be easily applied and accurately dosed.

[0052] According to some embodiments, said curable lacquer is applied onto said embossing roller by means of a roller coater, such as a lick roller, a comma bar coater or a meyer bar coater. Alternatively a curtain coater or a slot coater may be used to apply said curable lacquer onto said embossing roller. Applying the curable lacquer by means of a roller coater, such as a lick roller, a curtain coater or slot coater allows that the thickness of the curable lacquer may be set more accurately.

[0053] According to a further or another embodiment, said curable lacquer is final cured after said step of embossing by means of excimer and / or LED and / or EB (electron beam) curing and / or UV (ultraviolet) curing. This provides for that the curable lacquer can be cured in a simple manner and a good degree of crosslinking can be obtained. This has a positive influence on the mechanical and chemical resistance. Notwithstanding the curable lacquer being at least partly precured or not, final curing the curable lacquer after the step of embossing may allow to obtain a relief of high quality and / or may improve the scratch and / or wear resistance.

[0054] In some embodiments, preferably after final curing said curable lacquer, an additional curable lacquer may be applied. Preferably, in such case, a primer, more particularly an adhesion primer, is provided on the cured lacquer, i.e. in between said additional curable lacquer and said curable lacquer. The primer may for example by PVAc or a polyurethane dispersion, more particularly a UV curable polyurethane dispersion with acrylate functionalities. A primer may provide an enhanced adherence of said additional curable lacquer on the cured lacquer. Alternatively, said additional curable lacquer is applied on the not yet fully cured, semi-cured, or uncured curable lacquer. In such case a good adherence may be obtained in the absence of primer layers, although the use of a primer is not excluded in such case as well. By applying an additional curable lacquer, scratch and / or wear resistance may be further improved, or specific visual effects may be obtained. To this aim, the additional curable lacquer preferably is provided after the relief is formed. Then, the additional curable lacquer in fact does not have to be embossed, such that, for example, a harder lacquer material can be chosen.

[0055] In some embodiments, the additional curable lacquer may have a gloss degree which is different from the curable lacquer, and / or the additional curable lacquer may be cured using another technique, thereby obtaining specific visual effects.

[0056] According to a special embodiment, said additional curable lacquer is an excimer curable lacquer. Such additional lacquer layer allows to set the gloss or mat level of the finally obtained surface of the decorative panel.

[0057] By preference, said additional curable lacquer is applied on the full surface of the curable lacquer, and, in particular by preference also in any embossments contained in said curable lacquer. As such, the additional curable lacquer may further improve the scratch and / or wear resistance.

[0058] Preferably, said additional curable lacquer comprises particles, preferably particles of A12O3, SiC, SiO2 or the like, wherein the particles contained in said additional curable lacquer have a particle size distribution with a D50, preferably a D90 value of 40 pm or less. Such small particles give exceptional scratch resistance at the surface of the decorative panel obtained. Preferably, either particles are absent from the curable lacquer, or, particles, preferably particles of A12O3, SiC, SiO2 or the like, are present in said curable lacquer, wherein the particles contained in said curable lacquer have a particle size distribution with a D90, preferably a D50 value larger than 40 pm, or even larger than 60 pm.

[0059] Preferably, said additional curable lacquer has a thickness smaller than the thickness of said curable lacquer. Preferably said additional curable lacquer has a thickness equalling or smaller than half the thickness of said curable lacquer. For example the curable lacquer may have a thickness of 80 to 300pm, while the additional curable lacquer has a thickness of 40 pm or less. In any case, it is preferred that the additional curable lacquer is different or discernible, e.g. by visual inspection possibly by means of a microscope, from the curable lacquer layer at least because of one or a combination of two or more of the following properties:

[0060] - the property that the curable lacquer and the additional curable lacquer comprise different cross-linkable resins. For example said curable lacquer may comprise a multifunctional acrylate monomer and / or oligomer, while said additional curable lacquer layer may comprise a methacrylate;

[0061] - the property that the curable lacquer and the additional curable lacquer comprise at least a portion of an identical or similar cross-linkable resin, for example both comprising a multifunctional acrylate monomer or oligomer, but wherein the respective portions are mutually different. For example, the resin of the curable lacquer may for at least 75wt% consist out of a multifunctional acrylate monomer or oligomer, while the resin of the additional lacquer may for 70 wt% or less consist out of the same multifunctional acrylate monomer or oligomer;

[0062] - the property that the curable lacquer and the additional curable lacquer comprise different initiators for crosslinking or a different initiator mix.

[0063] - the property that the curable lacquer and the additional curable lacquer have a different content of particles. For example, the additional curable lacquer may comprise particles of A12O3, SiC, SiO2 or the like, while such particles are absent or substantially absent from said curable lacquer. Such particles may bring additional scratch and wear resistance to the surface of the obtained decorative panels. Alternatively or in combination, the particles, preferably particles of A12O3, SiC, SiO2 or the like, contained in said additional curable lacquer may show a particle distribution with a D50 value smaller than, preferably less than 90% of, the D50 value of the particle distribution of particles contained in the curable lacquer. Alternatively or in combination, as expressed in grams per square meter, the curable lacquer comprises more particles, preferably particles of A12O3, SiC, SiO2 or the like, than said additional curable lacquer.

[0064] According to some embodiments, said embossing step defines deformed portions and undeformed portions in the surface of the curable lacquer, wherein, alternatively by preference, said additional curable lacquer is only applied on the undeformed portions. This is particularly advantageous in case a curable lacquer and an additional curable lacquer with a different gloss degree are used and / or in case these are cured using another technique. Special effects may be obtained, where the curable lacquer is visible at least in the deepest embossments, or deformed portions, and the additional lacquer is visible at least on the global upper surface, or undeformed portions.

[0065] According to some embodiments, said additional curable lacquer is cured via excimer and / or LED, such as UV LED, and / or electron beam (EB) and / or UV (Ultraviolet) curing. This provides for that the curable lacquer can be cured in a simple manner and a good degree of crosslinking can be obtained. This has a positive influence on the mechanical and chemical resistance. In particular, the additional curable lacquer is curable by means of excimer radiation, preferably followed by UV curing. This allows obtaining a matte finish.

[0066] Said curable lacquer and said additional curable lacquer preferably are cured together. It is clear that in such case said curable lacquer is not yet fully cured, semicured, or uncured when applying said additional curable lacquer. This is advantageous in view of the fact that then only one curing station will have to be provided to this aim. Moreover, this common curing provides for that a mutual crosslinking can occur between the lacquer layers. This is beneficial for features, such as adherence, wear resistance, scratch resistance and stain resistance.

[0067] However, it may also be possible that the curable lacquer and the additional curable lacquer are cured separately. In that case, it can be chosen for curing both layers with a different technique.

[0068] According to a further or another embodiment, said curable lacquer is realized on the basis of a polyurethane dispersion or acrylate dispersion and / or a combination of both. This results in that the lacquer layer can be embossed in a simple manner. By preference, the solid matter content of the PU and / or acrylate dispersion is situated between 30% and 50%, or even more preferably between 30% and 40%. According to a further or another embodiment, said curable lacquer comprises an acrylate copolymer. Such copolymer provides extra flexibility.

[0069] The curable lacquer layer may comprise a crosslinker. An example of a suitable crosslinker is polyaziridine and / or isocyanate.

[0070] The curable lacquer may comprise one or more photo-initiators and / or thermo-initiators.

[0071] According to the most preferred embodiment, said curable lacquer is an acrylate resin or unsaturated polyester resin, comprising at least one or more thermo-initiators, e.g. an organic peroxide, preferably benzoyl peroxide or lauryl peroxide or tertiary butylperoxyl-3,5,5-trimethylhexanoate (TBPIN). Preferably said curable lacquer comprises 0.1-5 parts by weight of thermo-initiator per 100 parts of said acrylate or unsaturated polyester resin. The curable lacquer may further comprises 0.1 to 5 parts by weight of photo-initiator. In the case of an acrylate resin, such resin preferably comprises a multifunctional acrylate monomer and / or oligomer, such as a hexafunctional acrylate oligomer, and, preferably said acrylate resin is of the aliphatic type. For example, such resins as disclosed in WO 2020 / 095196, incorporated herein by reference in its entirety, may be applied as said curable lacquer.

[0072] In some embodiments, said curable lacquer is substantially free of solid particles. By using a curable lacquer of substantial thickness according to the invention, solid particles can be omitted, however while still obtaining good scratch and / or wear resistance. According to an alternative, said curable lacquer and / or said additional lacquer, when available, may comprise particles of A12O3, SiC, SiO2 or the like. Such particles may bring about an exceptional abrasion and / or scratch resistance. Particles in the curable lacquer preferably have a particle size distribution with a D50 value between 45 and 180 micrometer. Preferably the D10 value is above 10 micrometer, and the D90 value is preferably below 220 micrometer. Preferably, said wear layer, when available, is transparent or translucent. This may allow good visibility of the decorative layer.

[0073] Preferably, said curable lacquer, preferably also after curing, is transparent or translucent. This may further improve the visibility of the decorative layer through the combined wear layer and curable lacquer.

[0074] In some embodiments, said decorative layer is colored and / or comprises a first printed pattern. Preferably, said decorative layer is a prefabricated thermoplastic foil or paper carrying a printed pattern. The printed pattern may be obtained by means of digital inkjet printing. According to an alternative said decorative layer is formed by direct application of inks on the substrate material, with the potential intermediate of one or more primer layers. The application of inks may be executed in a digital manner, for example by means of digital inkjet printing.

[0075] According to a further or another embodiment, at least a part of said wear layer comprises a second printed pattern. As such the first printed pattern and the second printed pattern may cooperate as to obtain an enhanced visual effect on different levels, which are visible through the wear layer and the curable lacquer on the surface of the decorated panel.

[0076] According to a further or another embodiment, said method comprises an additional embossing step, said additional embossing step is performed after said embossing step, and preferably after said step of applying the additional curable lacquer.

[0077] In some embodiments, said embossing step and / or said additional embossing step is performed in register with the first printed pattern of the decorative layer and / or with the second printed pattern of the wear layer. Such embossment in register with either the first printed pattern or the second printed pattern, or with both patterns, may further result in a visually very realistic decorated panel.

[0078] It may be possible that only a single substrate layer is provided. It may also be possible that multiple substrate layers are provided. The one or more substrate layers can be formed in any suitable manner. For example, strewing, extrusion and / or calendaring techniques are employed. By preference, said one or more substrate layers comprise a thermoplastic material.

[0079] Preferably, said temperature is from 130°C to 180°C.

[0080] Preferably, in said step of embossing a pressure of at least 20 kg / cm2is exerted on said curable lacquer layer, wherein preferably said pressure is 50 kg / cm2or less.

[0081] With the same aim as in said first independent aspect, the present invention, in accordance with its second independent aspect is a decorative panel, which comprises a substrate layer, a decorative layer, a wear layer provided above said decorative layer, and a lacquer layer provided above said wear layer, wherein the decorative panel has an upper surface showing a relief, said relief is present in at least the lacquer layer, wherein the thickness of said wear layer is 50 to 200 micrometer and said lacquer layer has a weight of 50 to 200 grams per square meter.

[0082] It is clear that the decorative panel of said second independent aspect may be obtained through a method in accordance with the first aspect of the invention and / or the preferred embodiments thereof, and that, as a result, the decorative panel of said second aspect may show corresponding preferred embodiments as mentioned in connection with said first aspect without necessarily having been manufactured in accordance with the first aspect.

[0083] The invention in its second aspect may have one or more advantages over what is known in that by having the above-mentioned ratio, a thinner wear layer may be applied. Using a thinner wear layer may have the advantage that transparency is improved, thus making the decorative layer underneath better visible at the surface of the decorative panel. Furthermore, by combining a wear layer and a lacquer layer following the above- mentioned thickness and weight, at least the same scratch and / or wear resistance, or an even improved scratch and / or wear resistance, may be obtained in comparison to wear layers which are known in the art. As the relief is at least, and preferably only, present in the lacquer layer, the risk may furthermore be reduced of having uncoated spots on the surface of the decorative panel, and gloss of the surface of the decorative panel may be determined by the lacquer layer and / or by the embossment structure or relief.

[0084] By preference, the thickness of said wear layer and the thickness of said lacquer layer follow a ratio of between 4: 1 and 1:20, more by preference ofbetween 3: l and 1: 15, even more by preference of between 2:1 and 1 : 10, most by preference of between 1 : 1 and 1 : 10. With increased preferability, the transparency is further improved while still maintaining at least the same scratch and / or wear resistance, or while even improving the scratch and / or wear resistance.

[0085] By preference, said lacquer layer has a thickness on said wear layer of between 10 and 800pm, preferably between 50 and 300 pm. Within said thickness range, the lacquer layer has sufficient thickness to provide improved scratch and / or wear resistance, while still allowing optimal transparency of the combined curable lacquer and wear layer. The decorative panel may show at least one of the following properties:

[0086] - the property that said lacquer layer has a thickness of at least 100 pm, or at least 150 pm;

[0087] - the property that said lacquer layer has a thickness of between 10 and 800 pm;

[0088] - the property that said lacquer layer has a thickness of between 50 and 800 pm;

[0089] - the property that said lacquer layer has a thickness of between 50 and 300 pm; or

[0090] - the property that said lacquer layer has a thickness of between 300 and 800 pm;

[0091] - the property that said wear layer is a thermoplastic foil, and, preferably the thickness of said thermoplastic foil and said lacquer layer follow a ratio of between 5: 1 and 1 :50, preferably between 5:1 and 1 :25.

[0092] As mentioned, such decorative panel may be obtained with a method similar to the method of the first aspect and / or the preferred embodiments thereof. For example, the components, for example acrylate resins, unsaturated polyester resins, thermo-initiators and / or photo-initiators listed in the context of the first aspect for said curable lacquer may also be applied in the present decorative panel. The additional lacquer layers mentioned in the first aspect may also be applied. It may be possible that the decorative panel only comprises a single substrate layer. It may also be possible that multiple substrate layers are provided. By preference, said one or more substrate layer comprises a thermoplastic material.

[0093] It is noted that, preferably, in the context of any of the aspects of the present invention, said decorative layer is a prefabricated thermoplastic foil or paper carrying a printed pattern. The printed pattern may be obtained by means of digital inkjet printing. According to an alternative said decorative layer is formed by direct application of inks on the substrate material, with the potential intermediate of one or more primer layers. The application of inks may be executed in a digital manner, for example by means of digital inkjet printing.

[0094] Where particle sizes, such as DIO, D50, D90 value, and particle size distributions are discussed in the present disclosure, this preferably concerns particle sizes and distributions as defined by laser light granulometry performed in accordance with ISO 13320, namely by a dynamic light scattering technique using a laser having an emission wavelength of 632.8 nm and measured under a scattering angle of 90 degrees. Such granulometry may e.g. be performed with a Malvern® Mastersizer 2000 or with a Malvern® Mastersizer 3000. For executing the measurement of the particle size distribution, the respective particles may be dispersed in a liquid, such as water.

[0095] In order to better demonstrate the features of the invention, some preferred embodiments are described below, by way of example and without any limiting character, with reference to the accompanying drawings, wherein: figure 1 schematically illustrates a method for manufacturing a decorative panel in accordance with the invention; figure 2 gives a larger view on the area indicated with F2 on Figure 1; figures 3 to 8 in a same view as figure 2 represent variants; figure 9 illustrates at a larger scale a cross-section in accordance with line IX-IX in figure 3; figure 10 illustrates at a larger scale a cross-section in accordance with line X-X in figure 1 ; figures 11 to 14 in a view similar to that of figure 10 illustrate variants; and figure 15 and 16 in a same view as figure 2 illustrate variants.

[0096] Figure 1 shows a method for manufacturing a decorative panel 10 in accordance with the invention, comprising at least the step SI of providing a substrate material 1, the step S2 of providing at least a decorative layer 2 and a wear layer 3 onto said substrate material 1, wherein said wear layer 3 is located above said decorative layer 2, the step S3, not shown, of providing a curable lacquer 4 on said wear layer 3, and the step S4 of embossing at least said curable lacquer 4, wherein the thickness TW of said wear layer 3 and the thickness TL of said curable lacquer 4 follow a ratio of between 5 : 1 and 1 :25. As is shown in Figure 1, providing of the substrate material 1 may be performed by an extrusion operation, which comprises a feed 5 for feeding raw material for the substrate material 1 to the extruder 6. The raw material is extruded through a so-called flat die or slot die 7 in to a flat substrate material 1, for example having a width of 1 to 2.1 meter, preferably about 1.3 meter and a thickness TS of 2 to 7 mm, by preference of 3 to 6 mm, more by preference of 3 to 5 mm, even more by preference of 3.5 to 4.5 mm. After leaving said slot die 7, the substrate material 1 continuously moves in a feeding direction F to be subjected to said steps S2-S4. It is furthermore shown in Figure 1 that the resulting material may be further divided into slabs 9 comprising a plurality of decorative panels and / or consequently divided into decorative panels 10. In a subsequent step, not shown, these decorative panels may at one or more pairs of opposite edges 23-24-25-26 be provided with coupling means enabling a glueless floating installation of a plurality of such decorative panels 10 into a covering, such as a floor covering. The coupling means may be substantially or wholly formed in the substrate material 1 and / or said decorative layer 2, wear layer 3 and lacquer layer 4. The coupling means may basically be shaped as a tongue and groove connection comprising mechanical locking means preventing the drifting apart of the tongue and groove. Examples of such coupling means are for example disclosed in WO 2011 / 077311. The decorative layer 2, in this case a thermoplastic foil 27 with an applied thereon printed pattern 28, has a thickness TF, wherein the thickness TF of said thermoplastic foil 27 and the thickness TL of said lacquer layer 4 follow a ratio of between 5: 1 and 1 :50, preferably between 5: 1 and 1 :25.

[0097] In the present example, as better shown in Figure 2, said curable lacquer 4 is provided onto said wear layer 3 before the step S2 of providing at least said decorative layer 2 and said wear layer 3 onto said substrate material 1. Said curable lacquer 4 may have a thickness TL on said wear layer 3 of between 10 and 800 pm, preferably between 50 and 300 pm and / or may be a thermally curable and / or radiation curable, e.g. excimer curable and / or UV curable and / or LED curable and / or electron beam curable, lacquer. In the present example, said curable lacquer 4 is thermally curable and UV curable. Preferably, said curable lacquer 4 is precured onto said wear layer 3 before the step S2 of providing at least said decorative layer 2 and said wear layer 3 onto said substrate material 1. Such precuring of the curable lacquer 4 on the wear layer 3 may be performed offline, and is not explicitly illustrated in Figure 2. It is furthermore shown that said step S2 of providing at least said decorative layer 2 and said wear layer 3 onto said substrate material 1, and the step S4 of embossing said curable lacquer 4 on said wear layer 3 is performed at the same time. Herein, said step S2 of providing at least said decorative layer 2 and said wear layer 3 onto said substrate material 1, and the step S4 of embossing said curable lacquer 4 on said wear layer 3 is performed by means of a single lamination / embossing roller 8. Preferably, said embossing roller 8 is heated such that hot embossing of the curable lacquer 4 is obtained. The curable lacquer 4 is finally cured after embossing by means of the UV curing device 14. It is noted that the curable lacquer 4 may or may not comprise solid particles, such as abrasive particles or particles of aluminum oxide or silicon carbide.

[0098] Figures 3 and 4 represent variants illustrating the fourth possibility mentioned in the introduction. Herein said curable lacquer 4 is provided onto said wear layer 3 between the step S2 of providing at least said decorative layer 2 and said wear layer 3 onto said substrate material 1, and the step S4 of embossing and at least partially curing said curable lacquer 4. In these cases where the step S2 of providing the decorative layer 2 and the wear layer 3 onto the substrate material 1 are performed separately from the embossing step S4, one or more lamination rollers 11 may be provided, while embossing is performed by means of an embossing roller 8, preferably a heated embossing roller 8. Said curable lacquer 4 may have a thickness TW on said wear layer 3 of between 10 and 800 pm, preferably between 50 and 300 pm, and / or may be a thermally curable and / or radiation curable, e.g. excimer curable and / or UV curable lacquer. In the particular example of Figure 3, it is shown that, said curable lacquer 4 may be precured onto said wear layer 3 before the step S4 of embossing said curable lacquer 4. It may herein be that said curable lacquer 4 is at least partly precured prior to said step S4 of embossing by means of a UV curing device 14. In the particular example of Figure 3, the curable lacquer 4 is provided onto said wear layer 3 by means of a roller coater, more particularly a lick roller 12. As an alternative, in Figure 4, it is shown that said curable lacquer 4 is provided onto said wear layer 3 by means of a transfer film 13 containing said curable lacquer 4. The curable lacquer 4 may be applied to the transfer film 13 by means of a roller coater, such as by means of a lick roller 12. It may be that the curable lacquer 4 is at least partly precured on the transfer film 13 before applying it on the wear layer 3, which may be done by means of a UV curing device 14. It is noted that the curable lacquer 4 may or may not comprise solid particles, such as abrasive particles.

[0099] Figures 5 and 6 represent variants wherein said curable lacquer 4 is provided onto said wear layer 3 during the step of embossing said curable lacquer 4. Said curable lacquer may be relatively thinly applied, such as shown in Figure 5, wherein said curable lacquer 4 has a thickness TL on said wear layer 3 of between 10 and 100 pm. Alternatively, said curable lacquer 4 may be relatively thickly applied, such as shown in Figure 6, wherein said curable lacquer 4 has a thickness TL on said wear layer 3 of between 300 and 800 pm, preferably between 500 and 800 pm. In both cases, said curable lacquer 4, before providing it onto said wear layer 3, is applied onto an embossing roller 8 used during the step S4 of embossing said curable lacquer 4. Said curable lacquer 4 may herein be applied onto said embossing roller 8 by means of a lick roller 12. Optionally, as shown in Figure 6, said curable lacquer 4 may be at least partly precured on the embossing roller 8 by means of a UV curing device 14, before finally applying it onto the wear layer 3. In the present examples, a pretreatment may be present on the wear layer 3, such as a UV primer or bulk UV coating. In each of the aforementioned variants, said curable lacquer 4 is preferably final cured after said step S4 of embossing said curable lacquer 4 by means of excimer and / or UV curing, which may be performed by a UV curing device 14 and / or an excimer curing device 15. It is clear that both options remain possible, either alone or in combination, in any of the variants as illustrated. In the present examples of Figures 5 and 6, the curable lacquer 4 may be colored and / or stained and may thus serve the purpose of obtaining special visual effects. In particular, using a colored and / or stained curable lacquer 4 may allow to obtain staining and / or texturing in register.

[0100] Figure 7 represents a variant of the example as shown in Figure 2, wherein after final curing said curable lacquer 4, an additional curable lacquer 16 is applied. It may be that said additional curable lacquer is applied on the full surface of the curable lacquer 4. Alternatively, it may be that the surface is only partly covered by the additional curable lacquer 16. The additional curable lacquer 16 may be applied by means of a roller coater, such as by means of a lick roller 12. Final curing may be done by means of UV curing 14 and / or excimer curing 15.

[0101] Figure 8 represents a variant of the example as shown in Figure 2, wherein a thermoplastic primer 17 is provided in between said wear layer 3 and said curable lacquer 4. The relief obtained by embossing may be only present in the curable lacquer 4, or may even extend to below the curable lacquer 4, thereby partly perforating the curable lacquer 4. In the latter case, the thermoplastic primer 17 may penetrate through such perforations out onto the surface of the decorative panel.

[0102] In each of the variants shown, it may be that said curable lacquer 4 comprises two or more lacquer layers, said lacquer layers preferably having a different gloss degree.

[0103] It is also possible that said curable lacquer 4 is applied in several substeps, which do not necessarily have to apply a same or similar application method. For example, a first portion of said curable lacquer 4 may be pre-applied to the wear layer 3, similar to that what is shown in figures 2, 7 or 8, while a second portion may be liquidly applied downstream from providing said wear layer 3 and decorative layer 2 on the substrate material 1, for example similar to that what is shown in figures 3, 4 ,5 or 6.

[0104] Figure 9 illustrates a cross-section according to line IX-IX which corresponds to the layered build-up of a substrate layer 1 A, a decorative layer 2, a wear layer 3 and a lacquer layer 4A obtained from a curable lacquer 4 in accordance with the invention, wherein figure 9 shows the layered build-up before embossing at least said lacquer layer 4A, wherein the thickness TW of said wear layer 3 and the thickness TL of said curable lacquer 4 or lacquer layer 4A follow a ratio of between 5: 1 and 1 :25.

[0105] Figures 10 to 14 illustrate various cross-sections which correspond to the build-up of a decorative panel 10 in accordance with various embodiments of the invention. It is shown that the decorative panel 10 comprises a substrate layer 1 A, a decorative layer 2, a wear layer 3 provided above said decorative layer 2, and a lacquer layer 4A provided above said wear layer 3, wherein the decorative panel 10 has an upper surface showing a relief, said relief is present in at least the lacquer layer 4A, wherein the thickness TW of said wear layer 3 and the thickness TL of said lacquer layer 4A follow a ratio of between 5: 1 and 1 :25. Preferably, said lacquer layer 4A has a thickness TL on said wear layer 3 of between 10 and 800pm, preferably between 50 and 300 pm. Figure 10 also shows the relief in the lacquer layer 4, comprising deformed portions 18 and undeformed portions 19.

[0106] Figure 11 illustrates a variant that may be obtained through the method illustrated in figure 7, wherein an additional lacquer layer 16A is present, said additional lacquer layer 16A is present on the full surface of the lacquer layer 4A. In the alternative, Figure 12 illustrates a variant wherein said relief comprises deformed portions 18 and undeformed portions 19 on the surface of the lacquer layer 4 A, and wherein said additional lacquer 16A is only applied or mainly available on the undeformed portions 19.

[0107] Figure 13 illustrates a variant that may be obtained through the method illustrated in figure 8, wherein the relief is substantially deep, and wherein at least some of the deformed portions 18 protrude throughout the lacquer layer 4A. In the present example, a thermoplastic primer 17 is present in between the wear layer 3 and the lacquer layer 4A. In those regions where the deformed portions 18 protrude throughout the lacquer layer 4A, the thermoplastic primer 17 is able to wholly or partially fill the interruptions 20 in the lacquer layer 4A.

[0108] Figure 14 illustrates a decorative panel 10 which is mainly identical to the embodiment shown in figure 12, but where the wear layer 3 has been omitted. In so doing, an embodiment in accordance with the fourth independent aspect is obtained. The decorative panel 12 of figure 14 shows the preferred property that the lacquer layer 4A has a thickness TL of at least 150 pm. The decorative layer 2 comprises a printed pattern 28 applied to a thermoplastic foil 27. The thickness TF of the thermoplastic foil 27 and said lacquer layer 4A follow a ratio of about 1 :2,5. The decorative panel 10 is free from polyvinylchloride in the portion of said panel 10 that is positioned above said decorative layer 2. The lacquer layer 4A is obtained from an acrylate resin, preferably an acrylate resin comprising 0.1 to 5 parts by weight of thermo-initiators and / or photo-initiators per 100 parts of acrylate. The additional lacquer layer 16A is obtained from the same acrylate resin, but, in contrast to the curable lacquer layer 4A, comprises particles wherein the particle size distribution of said particles has a D90 value of 40 pm or less. Particles are absent in said curable lacquer layer 4A.

[0109] It is clear that when the wear layer 3 of figure 11 were to be omitted that a similar embodiment as that of figure 14 could be obtained, but wherein the additional lacquer layer 16A covers the entire surface of the decorative panel 10. Such decorative panel 10 forms an example of the fourth independent aspect of the present invention.

[0110] Figure 15 illustrates some steps S2-S4 in a method for manufacturing decorative panels in accordance with the first independent aspect of the invention. Figure 15 is essentially identical to Figure 2 with this exception that the decorative layer 2 and the wear layer 3 are separately and subsequently provided on the substrate material 2. The decorative layer 2 is laminated to said substrate material 2 by means a lamination roller 11, which is separate and arranged upstream from the embossing roller 8 which provides said wear layer 3 on top of said already laminated decorative layer 2. An additional lamination roller 11 for separate lamination of the decorative layer 2 upstream of the provision of said wear layer 3, may be available in any of the embodiments illustrated in figures 2 to 8.

[0111] Figure 16 illustrates another variant which is essentially identical to Figure 2 with this exception that the decorative layer 2, instead of being a prefabricated thermoplastic foil 27 with an applied thereon printed pattern 28, is formed by direct application of inks 29 on the substrate material 1, more particularly with the intermediate of one or more primer layers 30 that are applied on said substrate material 1 upstream of the ink application. The application of inks is in this case, as schematically represented in figure 16, executed by means of a digital printer 31 of the single pass type.

[0112] The decorative layer 2 illustrated in any of the figures 2 to 8, may be replaced by a decorative layer 2 comprising inks 29 directly applied to the substrate material 1, preferably with the intermediate of one or more primer layers 30, as illustrated in figure 15. In such case, and in particular in figure 3, 4, 5 and 6 the wear layer 3 may be omitted, and the curable lacquer layer 4 may be applied directly on the decorative layer 2 comprising said inks 29 which are directly applied to the substrate material 1.

[0113] In general, with respect to the figures, it is noted that where an embossing roller 8 is applied, such embossing roller 8 may be replaced by an alternative pressing element, such as by a structure foil, a structured press belt or a structured press plate. Such alternative pressing element may be applied in a continuously operating press. Alternatively, and in particular when a structured press plate is applied, this may be applied in a discontinuously operated press, for example in a so-called single daylight or multiple daylight press. Upstream from such discontinuously operated press, said substrate material 1 and the applied thereon decorative layer 2 and / or wear layer 3 may be divided into slabs 9, such that the discontinuously operated press is active on one or more of said slabs 9. It is further remarked that the additional embossing step mentioned in the introduction may be achieved by means of an embossing roller 8 or by means of an alternative pressing element, such as by one or more of the alternative pressing elements mentioned here directly above. The additional embossing step may be active on the substrate material 1 and the applied thereon decorative layer 2 and / or wear layer 3 and / or curable lacquer layer 4 and / or additional lacquer layer 16 while it is still in an endless format, or on slabs 9 obtained by dividing such endless substrate material 1. Such an additional embossing step may for example be applied for the formation of lowered areas which in the decorative panel 10 form lowered edge regions at one or more edges. Such lowered edge regions may for example comprise a beveled surface. Preferably, the curable lacquer layer 4A is available in said lowered edge region.

[0114] It is noted that, in the example of figure 8, the primer 17 is pre-applied on the wear layer 3, intermediate to the wear layer 3 and said curable lacquer 4. A primer 17 may be applied in any of the embodiments shown in the figures. In the cases of figures 2, 7, 8, 15 and 16, the primer 17 may be pre-applied to the wear layer 3 intermediate the wear layer 3 and the curable lacquer 4. In the cases of figures 3, 4, 5 and 6, the primer 17 may be either pre-applied to the wear layer, or be applied downstream from the lamination roller 11 and / or upstream from said step S3 of providing said curable lacquer 4.

[0115] In order to still further illustrate the features of the invention, some examples of prefabricated sheets are described here below, by way of example and without any limiting character. These prefabricated sheets comprise a curable lacquer layer and may be applied in a method according to the invention, i.e. for treating said prefabricated sheet in said press treatment at a temperature of 100°C or above, wherein, preferably said curable lacquer layer is substantially cured, preferably at least to a degree of curing of 85%, due to said press treatment.

[0116] Example 1 : A base print paper having a weight of 70 grams per square meter is provided with an inkjet receiver coating and digitally printed. Subsequently the printed paper is impregnated with a mixture of a melamine formaldehyde resin and an acrylic resin. The dry weight, i.e. at 7% residual humidity, of the applied resin is 70 grams per square meter. The dry weight, i.e. at 7% residual humidity, of the ink and inkjet receiver coating is 2 grams per square meter. A primer is additionally provided on the bottom of the impregnated paper layer, i.e. at the side opposite the printed pattern. The primer is a UV curable polyurethane dispersion primer and is applied at 8 grams per square meter. The total weight of the thus treated paper at 7% residual humidity is 150 grams per square meter.

[0117] The thus treated paper is then provided with 180 grams per square meter of a thermally and radiation curable lacquer. The lacquer is an acrylic resin comprising at least a thermoinitiators and at least a photo-initiator. The thermo-initiator is an organic peroxide. In this case TBPIN has been used at 0.5 parts per 100 parts of said acrylate resin. 0.5 parts of photo-initiator have been used as well. The acrylic resin comprises hexafunctional acrylic monomers and is of the aliphatic type. The acrylic resin comprises 10 grams per square meter of particles of A12O3, having a particle distribution with a D50 value of 65 micrometer.

[0118] The curable lacquer is precured or pre-gelled by means of UV radiation to create a less tacky or non-tacky surface.

[0119] In example 1, a prefabricated sheet as described as a third example in the introduction is achieved.

[0120] Example 2:

[0121] A base print paper having a weight of 70 grams per square meter is provided with an inkjet receiver coating and digitally printed. Subsequently the printed paper is impregnated with a mixture of a melamine formaldehyde resin and an acrylic resin. The dry weight, i.e. at 7% residual humidity, of the applied resin is 70 grams per square meter. The dry weight, i.e. at 7% residual humidity, of the ink and inkjet receiver coating is 2 grams per square meter. A primer is additionally provided on the bottom of the impregnated paper layer, i.e. at the side opposite the printed pattern. The primer is a UV curable polyurethane dispersion primer and is applied at 8 grams per square meter. A primer is additionally provided on the top of the impregnated paper layer. The same primer is used as on the bottom and at the same rate, 8 grams per square meter. The total weight of the thus treated paper at 7% residual humidity is 158 grams per square meter.

[0122] The thus treated paper is then provided with 180 grams per square meter of a thermally and radiation curable lacquer. The lacquer is an acrylic resin comprising at least a thermoinitiators and at least a photo-initiator. The thermo-initiator is an organic peroxide. In this case TBPIN has been used at 0.5 parts per 100 parts of said acrylate resin. 0.5 parts of photo-initiator have been used as well. The acrylic resin comprises hexafunctional acrylic monomers and is of the aliphatic type. The acrylic resin is free from abrasive particles such as A12O3, SiC, SiO2.

[0123] The curable lacquer is precured or pre-gelled by means of UV radiation to create a less tacky or non-tacky surface.

[0124] In example 2, a prefabricated sheet as described as a third example in the introduction is achieved.

[0125] Example 3 :

[0126] A transparent PVC foil having a thickness of 100 micrometer is provided. The PVC foil is a rigid PVC foil and is essentially free, or free, from plasticizers. A curable lacquer is provided on a surface of the PVC foil. The curable lacquer is the same as in example 2, but applied at a rate of 100 grams per square meter. The curable lacquer is precured or pre-gelled by means of UV radiation to create a less tacky or non-tacky surface.

[0127] In example 3, a prefabricated sheet as described as a first example in the introduction is achieved.

[0128] The prefabricated sheets of examples 1 to 3 may be applied in any of the example methods described by means of the accompanying drawings figures 1, 2, 7, 8, 15, 16 and their corresponding description above.

[0129] The aspects and concepts disclosed in the claims and drawings may be combined with one another as long as they are not mutually contradictory. The present invention is by no means limited to the embodiments described above, however a decorative panel may be realized according to various variants without departing from the scope of the present invention.

Claims

Claims.1 Method for manufacturing a decorative panel, comprising at least the following steps:- the step of providing a substrate material (1), wherein said substrate material (1) comprises one or more layers with thermoplastic material;- the step of providing at least a decorative layer (2) and a curable lacquer layer (4) onto said substrate material (1), wherein said curable lacquer layer (4) is located above said decorative layer (2) and wherein said lacquer layer (4) is at least in part curable by means of heat, and- the step of embossing at least said curable lacquer layer (4) using a press treatment, characterized in that said curable lacquer layer (4) is provided, more particularly adhered, onto said substrate material (1) in said press treatment, wherein said curable lacquer layer (4) in said press treatment is heated to a temperature of 100°C or above.2.- Method according to claim 1, characterized in that said curable lacquer layer (4) is provided on a transparent wear layer, wherein the thickness (TW) of said wear layer (3) and the thickness (TL) of said curable lacquer layer (4) follow a ratio of between 5:1 and 1 :25.3.- Method according to claim 2, characterized in that said curable lacquer (4) is provided onto said wear layer (3) before the step of providing at least said decorative layer (2) and said wear layer (3), inclusive said curable lacquer layer (4), onto said substrate material (1).4.- Method according to any of the preceding claims, characterized in that said press treatment is performed by means of an embossing roller.5.- Method according to any of claims 1 to 4, characterized in that said press treatment is performed by means of a discontinuous, single stage or multi stage, press.6.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) forms part of a prefabricated sheet together with a transparent wear layer and / or said decorative layer (2).7.- Method according to claim 6, characterized in that said decorative layer consists of inks forming the bottom of said prefabricated sheet, preferably applied to the bottom of a transparent wear layer, when available in said prefabricated sheet.8.- Method according to claim 6, characterized in that said decorative layer (2) is a printed paper sheet or a printed thermoplastic foil, wherein said prefabricated sheet comprises said curable lacquer layer (4) applied to said decorative layer (2).9.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) has a thickness (TL) of between 10 and 100 pm.10.- Method according to any of claims 1 to 8, characterized in that said curable lacquer layer (4) has a thickness (TL) of between 300 and 800 pm, preferably between 500 and 800 pm.11.- Method according to any of claims 1 to 8, characterized in that said curable lacquer layer (4) has a thickness (TL) of between 10 and 800 pm, preferably between 50 and 300 pm.12.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) comprises a thermally curable and / or radiation curable, e.g. excimer curable and / or LED curable and / or electron beam curable and / or UV curable, lacquer.13.- Method according to claim 12, characterized in that said curable lacquer layer (4) comprises a two-stage curable lacquer, one stage being thermally curable, another stage being excimer and / or LED and / or electron beam and / or UV curable.14.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) is precured, i.e. at least partly cured before the step of embossing said curable lacquer layer (4).15.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) is at least partly cured during said step of embossing.16.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) is finally cured after said step of embossing said curable lacquer layer (4) by means of excimer and / or LED and / or electron beam and / or UV curing.17.- Method according to claim 16, characterized in that after finally curing said curable lacquer layer (4), an additional curable lacquer (16) is applied, and, preferably, wherein between said additional curable lacquer (16) and said curable lacquer (4) a primer or adhesion primer is provided.18.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) is realized on the basis of a polyurethane dispersion and / or an acrylate dispersion.19.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) comprises an acrylate copolymer.20.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4) further comprises solid particles, for example particles of aluminum oxide and / or silicon carbide.21.- Method according to any of the preceding claims, characterized in that said curable lacquer layer (4), preferably also after curing, is transparent or translucent.22.- Method according to any of the preceding claims, characterized in that said decorative layer (2) is colored and / or comprises a printed pattern.23.- Method according to claim 22, characterized in that said embossing step is performed in register with the printed pattern of the decorative layer (2).24.- Method according to any of the preceding claims, characterized in that said substrate material (1) comprises a thermoplastic material.25.- Method according to any of the preceding claims, characterized in that said temperature is from 130°C to 180°C.26.- Method according to any of the preceding claims, characterized in that in said step of embossing a pressure of at least 20 kg / cm2is exerted on said curable lacquer layer (4), wherein preferably said pressure is 50 kg / cm2or less.27.- Decorative panel, which comprises a substrate layer (1A), a decorative layer (2), a wear layer (3) provided above said decorative layer (2), and a lacquer layer (4A) provided above said wear layer (3), wherein the decorative panel has an upper surface showing a relief, said relief is present in at least the lacquer layer (4A), wherein the thickness (TW) of said wear layer (3) is 50 to 200 micrometer and said lacquer layer has a weight of 50 to 200 grams per square meter.28.- Decorative panel according to claim 27, characterized in that said lacquer layer (4 A) is obtained from a thermally curable and / or radiation curable, e.g. excimer curable and / or LED curable and / or electron beam curable and / or UV curable, lacquer.29.- Decorative panel according to claim 27 or 28, characterized in that said lacquer layer (4A) is obtained from a two-stage curable lacquer, one stage being thermally curable, another stage being excimer and / or LED and / or electron beam and / or UV curable.30.- Decorative panel according to any of claims 27 to 29, characterized in that said lacquer layer (4A) has a thickness (TL) on said wear layer (3) of between 10 and 800pm,preferably between 50 and 300 pm, or between 10 and 100 pm, or of between 300 and 800 pm, preferably between 500 and 800 pm.31.- Decorative panel according to any of claims 27 to 30, characterized in that said lacquer layer (4A) is realized on the basis of a polyurethane dispersion and / or acrylate dispersion.32.- Decorative panel according to any of claims 27 to 31, characterized in that said lacquer layer (4A) is obtained from a resin comprising an acrylate copolymer.33.- Decorative panel according to any of claims 27 to 32, characterized in that said lacquer layer (4A) comprises solid particles, preferably particles of aluminum oxide and / or silicon carbide.34.- Decorative panel according to any of claims 27 to 33, characterized in that said wear layer (3) and / or said lacquer layer (4A) is transparent or translucent.35.- Decorative panel according to any of claims 27 to 34, characterized in that said decorative layer (2) is colored and / or comprises a printed pattern, wherein, preferably, said relief is in register with the printed pattern of the decorative layer (2).36.- Decorative panel according to any of claims 27 to 35, characterized in that said substrate layer (1 A) comprises a thermoplastic material.37.- Decorative panel according to any of claims 27 to 36, characterized in that said decorative panel shows at least one or a combination of two or more of the following properties:- the property that said lacquer layer (4 A) has a thickness (TL) of at least 100 pm, or at least 150 pm;- the property that said lacquer layer (4 A) has a thickness (TL) of between 10 and 800 pm;- the property that said lacquer layer (4A) has a thickness (TL) of between 50 and 800 pm;- the property that said lacquer layer (4A) has a thickness (TL) of between 50 and 300 pm; or- the property that said lacquer layer (4 A) has a thickness (TL) of between 300 and 800 pm;- the property that said decorative layer (2) comprises a printed pattern applied to a thermoplastic foil, and, preferably the thickness (TF) of said thermoplastic foil and the thickness (TL) of said lacquer layer (4A) follow a ratio of between 5:1 and 1 :50 or between 5: 1 and 1 :25;- the property that said decorative panel (10) is free from polyvinyl chloride in the portion of said panel that is positioned above said decorative layer (2).38.- Decorative panel according to any of claims 27 to 37, characterized in that said lacquer layer (4A) is a cured acrylate resin or unsaturated polyester resin, comprising at least one or more thermo-initiators, e.g. an organic peroxide, preferably benzoyl peroxide or lauryl peroxide or tertiary butylperoxyl-3,5,5-trimethylhexanoate (TBPIN).39.- Decorative panel according to any of claims 27 to 37, characterized in that said lacquer layer (4A) is a cured resin that is free or essentially free from thermo-initiators.40.- Method, respectively decorative panel according to any of the preceding claims, characterized in that said decorative layer (2) comprises a printed pattern obtained by means of digital inkjet printing.41.- Method, respectively decorative panel, according to any of claims 1 to 40, characterized in that said decorative layer (2) is formed by direct application of inks on the substrate material (1) or substrate layer (1A), with the potential intermediate of one or more primer layers, wherein the application of inks is preferably executed in a digital manner, for example by means of digital inkjet printing.

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