Coating composition and method of applying a coating composition

Abstract

An acrylate coating composition comprises (A) one or more acrylate and / or methacrylate oligomers; (B) one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents, wherein said reactive diluents have a molar mass lower than 800 g / mol; (C) one or more photo initiators; and (D) one or more thermo initiators. The coating composition comprises photo initiators in a combined amount less than 1 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).

Description

[0001] Coating composition and method of applying a coating composition

[0002] The invention relates to coating compositions for decorative panels. The invention relates more specifically to coating compositions applied in the production of decorative panels wherein the coating composition can provided with an embossed texture. The invention further relates to methods for partially curing (pre-gelling) coating compositions and to methods for manufacturing decorative panels comprising a coating layer.

[0003] W02020 / 095196A1 relates to a coated panel with at least a substrate and a top layer applied on the substrate. The top layer comprises at least a decor layer and a translucent or transparent wear layer. The wear layer comprises a thermally cured acrylate resin or a thermally cured unsaturated polyester resin. The thermal curing cures the resin partially or completely. The translucent or transparent wear layer can comprise an embossed relief.

[0004] WO202 1 / 224843 Al relates to a partially cured coated sheet. The sheet comprises a support layer and a coating layer on a side of the support layer. The coating layer is partially cured. The coating layer comprises carbon-carbon double bonds. The relative amount of carbon-carbon double bonds is higher at the surface of the coating layer than at the contact surface of the coating layer with the support layer. The coating layer can be an acrylate coating layer. Methods are disclosed for manufacturing such sheets; and for producing a decorative panel using such sheets.

[0005] WO2023 / 072891 Al discloses a radical-curable coating composition comprising (A) one or more oligomers selected from the group consisting of urethane (meth) acrylates, (meth)acrylated epoxidized triglycerides and any mixture thereof, wherein the oligomers have a molar mass equal to or higher than 800 g / mol and lower than 4500 g / mol, (B) one or more methacrylate reactive diluents having a molar mass lower than 800 g / mol, wherein the methacrylate reactive diluents have an average methacrylate functionality higher than 2, (C) one or more acrylate reactive diluents having a molar mass lower than 800 g / mol, wherein the acrylate reactive diluents have an average acrylate functionality higher than 2, (D) one or more photo-initiators, and (E) one or more thermal initiators, wherein the acrylate functionalities of the acrylate reactive diluents (C) and the methacrylate functionalities of the methacrylate reactive diluents (B) are present in a molar ratio of the acrylate functionalities to the methacrylate functionalities of at least 0.2, wherein the amount of oligomers (A) is higher than 20 wt.% and lower than 90 wt.% and the amount of reactive diluents (B) and (C) is higher than 10 wt.% and lower than 80 wt.%, based on the total amount of (A), (B) and (C), and wherein the total amount of (A), (B) and (C) is at least 25 wt.% of the radical-curable coating composition.

[0006] EP2154184A1 discloses a process for producing a thin matt lacquer layer onto a substrate, e.g. onto a floor panel. The thin layer has is between 8 and 20 micrometer thick. After applying a thin liquid lacquer layer onto a substrate, the lacquer is pre-dried, e.g. by means of UV radiation, followed by reticulation of the lacquer using an excimer type monochromatic radiation lamp and cross-linking the lacquer in a chamber under inert atmosphere using UV light.

[0007] US2017 / 0008334A1 discloses a method for producing a decorative panel. The method comprises the step of providing a carrier. A decoration is applied onto at least a partial region of the carrier. A lacquer-containing top layer is applied onto the decoration. The lacquer-containing top layer is partially cured. The partial hardening of the top layer is realized while forming a hardening gradient. The hardening gradient is established in the direction of the thickness of the top layer such that a surface region of the top layer is hardened comparably stronger than a deeper-lying region of the top layer. Subsequent to the partial hardening of the top layer, the top layer is provided with a structuring. The structuring is realized at least partially by a negative structuring. The lacquer-containing top layer is further hardened by means of radiation.

[0008] It is an objective of the invention to provide improvements to the prior art.

[0009] The first aspect of an invention relates to an acrylate coating composition. The coating composition comprises

[0010] (A) one or more acrylate and / or methacrylate oligomers; (B) one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents; wherein these reactive diluents have a molar mass lower than 800 g / mol, and preferably lower than 500 g / mol;

[0011] (C) one or more photo initiators; and

[0012] (D) one or more thermo initiators.

[0013] The acrylate coating composition comprises photo initiators in a combined amount less than 1 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).

[0014] The acrylate coating composition according to the invention only comprises a low amount of photo initiators. A coating layer obtained from the acrylate coating composition can be gelled first under neutral atmosphere (e.g. under nitrogen atmosphere). The coating layer can then be thermally pressed in which a thermal curing is performed. In such press operation no oxygen is present.

[0015] The low amount of photo initiators is beneficial as it reduces the cost of the coating composition considerably. The low concentration of photo initiators used is also beneficial for obtaining a more uniform curing of the coating layer obtained from the coating composition.

[0016] A preferred coating composition only requires a low amount of thermo initiators

[0017] Preferably, the coating composition comprises thermo initiators in a combined amount of less than 1 wt%, more preferably less than 0.5 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B). Such embodiments mean a reduction of the cost of the coating composition, while an efficient coating layer can be obtained. The low concentration of thermo initiators used is also beneficial for preventing the formation of cracks in the coating layer in a thermal curing step, as a high concentration of thermo initiators could result in a too fast progress of the exotherm curing reaction. The low concentration of thermo initiators also favors the formation of long polymer chains in thermal curing, thereby preventing the formation of a too brittle coating layer.

[0018] The oligomers preferably have a molar mass equal to or higher than 800 g / mol.

[0019] Preferably, the one or more acrylate and / or methacrylate oligomers have a molar mass lower than 4500 g / mol.

[0020] As used in this document, the molar mass of a compound is the calculated molar mass. The calculated molar mass is obtained by adding the atomic masses of all atoms present in the structural formula of a compound. When the exact structural formula of a compound is not known, the molar mass of the compound is the number average molecular weight determined using Triple Detection Size Exclusion Chromatography using tetra hydrofuran THF as eluent.

[0021] Preferably, the acrylate coating composition comprises photo initiators in a combined amount less than 0.5 wt%, more preferably less than 0.1 wt%, more preferably less than 0.06 wt%, more preferably less than 0.04 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).

[0022] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents have at least two (meth)acrylate functionalities. Such coating compositions result in coating layers have excellent mechanical properties.

[0023] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents comprise - and more preferably consist of - diluents having at least three (meth)acrylate functionalities. Such embodiments provide sufficient bonding of the diluents in the coating layer obtained and good cross linking in the coating layer obtained, such that migration of these diluents is prevented. Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents have a viscosity measured at 25°C between 1 and 3000 mPa.s, more preferably less than 1000 mPa.s. Such embodiments result in improved processing of the coating composition.

[0024] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents have a viscosity measured at 25°C between 160 mPa.s and 40 Pa.s. Such embodiments result in improved processing of the coating composition.

[0025] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents have an average molar mass higher than 100 g / mol.

[0026] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents have a maximal vapor pressure less than 0.02 mbar when measured at 20°. Such embodiments result in improved processing of the coating composition.

[0027] The one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents can include one or more than one of aliphatic and / or aromatic urethane (meth)acrylates, epoxy meth(acrylates), polyester (meth)acrylates, polyether (meth)acrylates, acrylated oligoamines, (meth)acrylated fatty acids derivatives, or combinations thereof.

[0028] Preferably, the one or more acrylate reactive diluents and / or methacrylate reactive diiluents and / or (meth)acrylamide reactive diluents comprise aliphatic diluents or consist of aliphatic diluents. Non yellowing of the coating layer obtained from such coating layers is a benefit of such embodiments. The one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents preferably have more than two (meth)acrylate functionalities. Such coating composites result in coating layers having excellent mechanical properties, e.g. wear resistance.

[0029] Examples of acrylate reactive diluents, methacrylate reactive diluents and (meth)acrylamide reactive diluents that can be used in the different aspects of the invention are: polyethylene glycol 600 diacrylate, tricyclodecanediol diacrylate, propoxylated neopentyl glycol diacrylate, bisphenol A derivative diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane ethoxy triacrylate, acrylated glycerol derivate, trimethylolpropane triacrylate, poly ether tetraacrylate, polyester acrylate, dipentaerythritol penta and / or hexa acrylate, pentaerythritol tri- and tetraacrylate (and mixtures thereof), dipropylene glycol diacrylate (DPGDA - CAS 57472-68-1), tricyclo(5.2.1.0 2,6)decanedimethanol diacrylate (TCDDA - CAS 42594-17-2), tricyclodecane dimethanol dimethacrylate (TCDDMA - CAS 43048-08-4), trimethylolpropane triacrylate (TMPTA - CAS 15625- 89-5), trimethylolpropane trimethacrylate (TMTPMA - CAS 3290-92-4), polyethylene glycol diacrylate (PEG600DA - CAS 26570-48-9), trimethylolpropane ethoxy triacrylate (TMP4EOTA - CAS 28961-43-5), trimethylolpropane (9 EO) triacrylate (TMP9EOTA - CAS 28961-43-5), trimethylolpropane (14 EO) triacrylate (TMP15EOTA - CAS 28961-43-5), 4-acryloylmorpholine ( ACMO - CAS 5117-12-4) and 4-hydroxybutyl acrylate (4-HBA - CAS 2478-10-6).

[0030] Preferably, the acrylate coating composition comprises photo initiators in a combined amount of more than 0.03 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).

[0031] An example of photo initiator that can be used in the invention is bis(2,4,6- trimethylbenzoyl) phenylphosphine oxide (CAS 162881-26-7). Preferably, the acrylate coating composition comprises thermo initiators in a combined amount of more than 0.2 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).

[0032] Preferably, in the combination of the (A) one or more acrylate and / or methacrylate oligomers and the total amount of the (B) one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents having a molar mass lower than 800 g / mol, the molar ratio of the methacrylates (meaning the combination of the methacrylate oligomers and the methacrylate reactive diluents) to the combination of the methacrylates and the acrylates (meaning the combination of the oligomers and the reactive diluents) is higher than 0.05 and more preferably below 0.4. Such embodiments provide an optimum reactivity of the coating composition in pregelling the coating composition using UV-curing steps.

[0033] A preferred coating composition is characterized in that the one or more photo initiators comprise or consist of Norrish type I photo initiators. Norrish type I photo initiators are preferred as they allow to achieve thick coating layers.

[0034] More preferred photo initiators comprise or consist of multifunctional Norrish type I photo initiators.

[0035] Preferred photo initiators comprise phosphine oxide Norrish type I photo initiators, e.g. phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO - CAS 162881-26-7).

[0036] Examples of photo initiators that can be used in the invention are difunctional alpha hydroxy ketone (CAS 71868-15-0), phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO - CAS 162881-26-7) and 1, l'-(methylene-di -4,1 -phenylene)bis[2 -hydroxy -2- methyl-1 -propanone] (CAS 474510-57-1).

[0037] A preferred coating composition is characterized in that the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the first thermo initiator. Such embodiment is beneficial, as it allows that in the thermal curing of a coating layer obtained from the coating composition (e.g. by means of a thermal pressing operation), the coating layer is gradually cured, resulting in a coating layer having better properties, e.g. mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0038] More preferably, the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the second thermo initiator. Such embodiment is beneficial, as it allows that in the thermal curing of a coating layer obtained from the coating composition (e.g. by means of a thermal pressing operation), the coating layer is gradually cured, resulting in a coating layer having better properties, e.g. mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0039] More preferably, the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the third thermo initiator. Such embodiment is beneficial, as it allows that in the thermal curing of a coating layer obtained from the coating composition (e.g. by means of a thermal pressing operation), the coating layer is gradually cured, resulting in a coating layer having better properties, e.g. mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0040] A preferred coating composition is characterized in that the coating composition comprises silica (SiCE), preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% (and more preferably less than 1 wt%) of the coating composition. The presence of silica in the coating composition has the benefit of improving the radiation induced curing in an excimer pre-gelling operation of a coating layer obtained from the coating composition. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0041] The silica can be micronized synthetic amorphous silica or silica-gel, for example Grace Syloid RAD 2005, having an average particle size of 5.5 micron.

[0042] The acrylate coating composition can comprise one ore more than one of 0.5 wt% BYK333, 0.4% antislip agents (e.g. tego glide 432), 3-5 wt% Ebecryll365, 2 to 5 wt% polyamide beads, e.g. with particle size between 20 pm and 120 pm, e.g. Orgasol.

[0043] The acrylate coating composition can comprise AI2O3. It has shown that the presence of aluminum oxide improves the curing when pre-gelling by means of excimer curing a coating layer obtained from the coating composition. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0044] Preferably, the acrylate coating composition comprises AI2O3 having a S50 particle size less than 30 micrometer. The S50 particle size in the context of this document is determined from the cumulative particle size distribution according to volume measured by laser diffraction, and is the particle size at which 50% of the particles are smaller than this particle size S50. The presence of such aluminum oxide particles improves the curing when pre-gelling by means of excimer curing a coating layer obtained from the coating composition. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0045] The use of aluminum particles having bigger S50 particle size, e.g. S50 particle size higher than 40 micrometer or even higher than 75 micrometer, is known for increasing the abrasion resistance of coating layers obtained from coating compositions. Preferably, AI2O3 particles are present in an amount more than 0.05 wt% of the total coating composition, and preferably of less than 7 wt% (and more preferably less than 2 wt%) of the coating composition.

[0046] A preferred coating composition is characterized in that the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica. Use of such coating compositions results in coating layers having improved abrasion resistance after curing them.

[0047] Preferably, the acrylate coating composition comprises wear resistant particles, e.g. corundum or silicon carbide, having an S50 particle size between 40 - 100 micrometer. The incorporation of such particles is beneficial to improve the abrasion resistance of coating layers obtained with the acrylate coating composition.

[0048] A preferred acrylate coating composition provides after curing a transparent or translucent coating layer.

[0049] The acrylate coating composition can comprise pigments and / or dyes, preferably in amount of 0.5 - 10 percent by weight. Such embodiments allow to obtain a colored coating layer.

[0050] A preferred acrylate coating composition is characterized in that the acrylate coating composition comprises a matting agent.

[0051] Such embodiments are preferred, as the production of a coating layer with a matte surface is facilitated. The structured press element used to emboss and cure the coating layer can be textured to provide a macro structure (e.g. embossments) to the coating layer as well as to provide a matte surface (or to provide different gloss levels) to the coating layer, the latter via copying the micro texture of the structured press element. However, when the required micro structure is too fine or too rough, it has been observed that the coating layer can stick to the structured press element, resulting in quality problems such as press element contamination. Adding a matting agent in the acrylate coating composition results in a coating layer that has a more matte surface without having the need to provide the structured press element with a very fine surface texture.

[0052] The matting agent preferably provides between 2 and 14 wt%, and more preferably between 3 and 10 wt%, of the acrylate coating composition.

[0053] A preferred matting agent for use in the invention is amorphous silica, preferably having S50 particle size between 3 and 20 micrometer. The S50 particle size is the particle size in the particle size distribution according to volume as determined using laser diffraction at which 50% of the particles are smaller than the S50. Amorphous silica has shown good compatibility with the acrylate coating composition.

[0054] The second aspect of the invention relates to a method for curing a coating layer to B- stage. The method comprises the steps of

[0055] - applying a coating composition on a carrier;

[0056] - optionally applying a first UV-radiation step to the carrier with the coating composition;

[0057] - applying a second UV-radiation step by passing the carrier with the coating composition on it under an excimer-type monochromatic radiation lamp; and

[0058] - applying a third UV-radiation step to the carrier with the coating composition on it; thereby obtaining a carrier with a coating layer onto it, wherein the coating layer is provided by partial curing of the coating composition to B-stage; wherein the surface of the coating layer is not tacky; wherein the coating composition applied onto the carrier comprises

[0059] (A) one or more acrylate and / or methacrylate oligomers, preferably wherein said oligomers have a molar mass equal to or higher than 800 g / mol and preferably lower than 4500 g / mol ;

[0060] (B) one or more acrylate reactive diluents and / or methacrylate reactive diluents and / or (meth)acrylamide reactive diluents; wherein these reactive diluents have a molar mass lower than 800 g / mol, and preferably lower than 500 g / mol;

[0061] (C) one or more photo initiators; and

[0062] (D) one or more thermo initiators. The following test method can be used for determining that the surface of the coating layer is not tacky. Ten square samples of 100 mm by 1000 mm are stacked onto each other and kept under a pressure of 800kg / m2during 1 hour at a temperature of 60°C. After removing the pressure, the sheets are taken off the stack. The surface of the coating layer is not tacky if the sheets can be taken off the stack without stickiness.

[0063] As the coating layer obtained in the method according to the second aspect of the invention is non-tacky, the carrier with B-stage coating layer on it can be stacked and stored during a long time.

[0064] The method has the benefit that a non-tacky coating layer is obtained, which can still be thermally pressed in which the coating layer is provided with an embossed surface copying the structure of a structured press element and during which the coating layer is thermally cured thanks to the presence of the one or more thermo initiators. In the thermal pressing operation, the microstructure of the coating layer of the B-stage coating layer is destroyed. The texture of the coating layer - embossments and gloss levels - is fully determined by copying the texture of the press element used in the thermal pressing operation.

[0065] It is believed that the thin skin obtained in the second UV-radiation step (which is an excimer radiation step) breaks and scatters in small pieces not having negative effects during thermal pressing and allows embossing the coating layer in the thermal pressing. It means that in the thermal pressing, the microstructure and gloss of the surface is destroyed. The coating layer receives its texture - including gloss levels which can vary over the surface of the coating layer - by copying the surface texture of the press element used in the thermal pressing operation.

[0066] The coating composition used in the second aspect of the invention can be a coating composition according to any embodiment of the first aspect of the invention. Preferably, the wavelength of the excimer-type monochromatic radiation lamp is less than 250 nm. More preferably, the wavelength of the monochromatic radiation lamp is 172 nm, wavelength which can be obtained using a Xe2 excimer lamp.

[0067] The optional first UV-radiation step can be performed. Such step has the benefit that a partial curing is obtained deeper in the coating layer. The optional first UV-radiation step is beneficial as it improves the formation of a cured skin of the coating layer in the second UV-radiation step which is an excimer radiation step.

[0068] The third UV-radiation step has the benefit that the coating layer below its skin cured by the second UV-radiation step - which is an excimer radiation step - is pre-gelled to a certain extent.

[0069] The optional first UV-radiation step can be performed using polychromatic radiation lamps.

[0070] The third UV-radiation step can be performed using polychromatic radiation lamps.

[0071] In the method of the second aspect of the invention, the coating composition can comprise photo initiators as defined in embodiments of the first aspect of the invention and / or in quantities as defined in embodiments of the first aspect of the invention.

[0072] In the method of the second aspect of the invention, the coating composition can comprise thermo initiators as defined in embodiments of the first aspect of the invention and / or in quantities as defined in embodiments of the first aspect of the invention.

[0073] When the optional first UV-radiation step is performed, preferably the carrier with the coating composition consecutively passes one or a plurality of UV-lamps in the first UV- radiation step. Such embodiments have the benefit that the UV-radiation energy is spread such that the curing performed in the first UV-radiation step is done gradually, resulting in less stress in the coating layer. More preferably, in the first UV-radiation curing step the carrier consecutively passes at least two or at least three, or exactly two or exactly three UV-lamps.

[0074] Preferably, the carrier with the coating composition consecutively passes one or a plurality of UV-lamps in the third UV-radiation step. Such embodiments have the benefit that the UV-radiation energy is spread such that the curing performed in the third UV- radiation step is done gradually, resulting in less stress in the coating layer. More preferably, in the third UV-radiation curing step the carrier consecutively passes at least two or at least three, or exactly two or exactly three UV-lamps.

[0075] Preferably, the third UV-radiation step is at least partially performed using out-of-focus UV-lamps. Such embodiments have the benefit that the radiation energy is more spread, resulting in a more gradual partial curing, preventing stress in the coating layer.

[0076] Preferably, the optional first UV-radiation step - when performed -, the second UV- radiation step, and the third UV-radiation step are performed in-line and continuously.

[0077] Preferably, the surface of the coating layer obtained is wrinkled and / or comprises micro folds. Such embodiments are preferred as it has the benefit that the surface of the coating layer is sufficiently cured by the second UV-curing step, beneficial for the non-tackiness of the coating layer.

[0078] In the step of applying the coating composition on the carrier, between 30 (and preferably at least 100) and 300 gram coating composition can be applied per square meter. Such embodiments have the benefit that a coating layer is obtained that can be embossed in a subsequent thermal pressing operation. Furthermore, such coating layer provides excellent wear resistance, e.g. when used as wear layer in a floor covering.

[0079] In a preferred embodiment, in the step of applying the coating composition on the carrier, a coating layer between 30 (and preferably at least 50) and 400 micrometer thick is obtained. Such embodiments have the benefit that a coating layer is obtained that can be embossed in a subsequent thermal pressing operation. Furthermore, such coating layer provides excellent wear resistance, e.g. when used as wear layer in a floor covering.

[0080] The carrier may comprise or consist of a printed paper sheet, preferably a paper sheet provided with thermoset resin, more preferably wherein the thermoset resin comprises a melamine formaldehyde resin, an acrylate resin or a polyurethane resin, or combinations thereof. The combinations of thermoset resin can be combinations via mixtures of resin, or via multiple layers of resin having different composition.

[0081] The carrier may comprise or consist of a plastic film - e.g. a printed plastic film or a transparent unprinted plastic film -, preferably wherein the plastic film is selected from a polyvinyl chloride film, a thermoplastic polyurethane film, a polypropylene film, a polyester film or a poly(methyl methacrylate) film. Such embodiments have the benefit that coating layers with good wear resistance are obtained, e.g. for floor panels. The coating layers can be embossed in a thermal pressing operation in which the coating layers are fully cured. Such embodiments also allow to provide panels - e.g. floor panels - that do not require a transparent plastic foil wear layer or only require a transparent plastic foil wear layer that is much thinner than the ones traditionally used.

[0082] More preferably, such plastic film (e.g. a printed plastic film or a transparent unprinted plastic film) is less than 200 micrometer thick, more preferably less than 150 mm thick, more preferably less than 120 micrometer thick, more preferably less than 100 micrometer thick and more preferably less than 80 micrometer thick, even more preferably less than 50 micrometer thick.

[0083] The carrier can comprise or consist of a printed board, e.g. a printed wood-based board, or printed mineral board or a printed -whether or not filled - plastics board.

[0084] The print on the printed paper sheet, on the printed plastic film or on the printed board allow to provide a product with a printed design. In a thermal pressing operation in which the coating layer is thermally cured, the coating layer can be embossed, even in register wit the printed design, for obtaining a very realistic imitation of a natural product, e.g. of wood.

[0085] Preferably, the B-stage coating layer comprises one or more thermo initiators. Such embodiments allow that the B-stage coating layer can be cured in a thermal curing step, e.g. a thermal pressing operation, even in which the coating layer can be embossed.

[0086] The one or more thermo initiators can comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the first thermo initiator. Such embodiments have the benefit that the B-stage coating layer can be thermally cured (e.g. by means of a thermal pressing operation), wherein the thermal curing is performed gradually, resulting in a coating layer having better properties, e.g. better mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0087] More preferably, the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the second thermo initiator. Such embodiments have the benefit that the B-stage coating layer can be thermally cured (e.g. by means of a thermal pressing operation), wherein the thermal curing is performed gradually, resulting in a coating layer having better properties, e.g. better mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0088] More preferably, the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the third thermo initiator. Such embodiments have the benefit that the B-stage coating layer can be thermally cured (e.g. by means of a thermal pressing operation), wherein the thermal curing is performed gradually, resulting in a coating layer having better properties, e.g. better mechanical properties such as wear resistance. Especially the formation of cracks in the coating layer is prevented.

[0089] The coating composition used in the method of the second aspect of the invention can comprise silica (SiCh), preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% (and more preferably less than 1 wt%) of the coating composition.

[0090] The presence of silica in the coating composition has the benefit of improving the radiation induced curing in the second UV-radiation curing, which is an excimer curing step. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0091] The silica can be micronized synthetic amorphous silica or silica-gel, for example Grace Syloid RAD 2005, having an average particle size of 5.5 micron.

[0092] The acrylate coating composition used in methods according to the second aspect of the invention can comprise one ore more than one of 0.5 wt% BYK333, 0.4% antislip agents (e.g. tego glide 432), 3-5 wt% Ebecryll365, 2 to 5 wt% polyamide beads, e.g. with particle size between 20pm and 120pm, e.g. Orgasol.

[0093] The acrylate coating composition used in the method of the second aspect of the invention can comprise AI2O3. It has shown that the presence of aluminum oxide improves the curing when pre-gelling by means of excimer curing in the second UV- radiation curing step a coating layer obtained from the coating composition. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0094] Preferably, the acrylate coating composition used in the method of the second aspect of the invention comprises AI2O3 particles having a S50 particle size less than 30 micrometer. The S50 particle size in the context of this document is determined from the cumulative particle size distribution according to volume measured by laser diffraction, and is the particle size at which 50% of the particles are smaller than this particle size S50. It has shown that the presence of such aluminum oxide particles improves the curing when pre-gelling by means of excimer curing - in the second UV-radiation curing step - a coating layer obtained from the coating composition. A more homogeneous coating surface is obtained when afterwards performing a thermal curing via thermal pressing on the pre-gelled coating layer.

[0095] The use of aluminum particles having bigger S50 particle size, e.g. S50 particle size higher than 40 micrometer or even higher than 75 micrometer, is known for increasing the abrasion resistance of coating layers obtained from coating compositions.

[0096] Preferably, AI2O3 particles are present in an amount more than 0.05 wt% of the total coating composition used in the method of the second aspect of the invention, and preferably of less than 7 wt% (and more preferably less than 2 wt%) of the coating composition used in the method of the second aspect of the invention.

[0097] Preferably, the coating composition used in the method of the second aspect of the invention comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica. Use of such coating compositions results in coating layers having improved abrasion resistance after fully curing them.

[0098] Preferably, the acrylate coating composition used in the method of the second aspect of the invention comprises wear resistant particles, e.g. corundum or silicon carbide, having an S50 particle size between 40 - 100 micrometer. The incorporation of such particles is beneficial to improve the abrasion resistance of coating layers after fully curing them.

[0099] The acrylate coating composition used in the method of the second aspect of the invention can comprise pigments and / or dyes, preferably in amount of 0.5 - 10 percent by weight. Such embodiments allow to obtain a colored coating layer.

[0100] A preferred method is characterized in that the optional first UV-radiation step is - when performed - not performed in an inert atmosphere. Such embodiments makes the process easier as less complex equipment is required, while good properties are obtained. As this curing step acts deeper in the coating layer, use of an inert atmosphere is not required.

[0101] A preferred method is characterized in that the optional first UV-radiation step is - when performed - performed in an inert atmosphere, e.g. in a nitrogen atmosphere. Such embodiments are beneficial, as already in the first UV-radiation step, more curing is performed at the surface of the coating composition, facilitating obtaining a non-tacky coating in the method of the second aspect of the invention.

[0102] A preferred method is characterized in that the second UV-radiation step and / or the third UV-radiation step is performed in an inert atmosphere, preferably under nitrogen atmosphere. Such embodiments provide a better coating layer.

[0103] A preferred method is characterized in that the coating layer is cured in the method to B- stage in which less than 60% of the acrylate double bonds at the surface of the coating layer are converted in the method, as measured using FTIR / ATR (Fourier Transform Infrared Spectroscopy / Attenuated Total Reflectance) using a diamond crystal.

[0104] Such embodiments facilitate that in a pressing operation the coating layer is provided with an embossed structure and even gloss differences, wherein the embossed structure and the gloss differences are obtained by copying the texture of the structured press element being used.

[0105] In FTIR / ATR using a diamond crystal, the conversion rate of the acrylate double bonds is determined by comparing the change of the amount of double bonds before and after curing the coating layer to B-stage. Using a diamond crystal, the penetration of the IR- waves in the test is about 2 to 3 micrometer, thus, the conversion rate of the acrylate double bonds is measured using FTIR / ATR (Fourier Transform Infrared Spectroscopy / Attenuated Total Reflectance) using a diamond crystal from the surface till this depth from the surface. A preferred method is characterized in that the step of applying a coating composition on a carrier comprises the step of applying a first coating composition on the carrier and a second coating composition on the first coating composition. The second coating composition provides on the carrier less than 40 % (and preferably less than 30 %) of the weight of the combination of the first coating composition and the second coating composition. The first coating composition as well as the second coating composition comprise (meth)acrylate oligomers and (meth)acrylate reactive diluents. The first coating composition and / or the second coating composition may be coating compositions as in any embodiment of the first aspect of the invention.

[0106] Such approach makes it possible to apply a cheap bulk layer and an expensive top layer which provides excellent surface properties to the coating layer.

[0107] Preferably, the second coating composition is applied thinner than the thickness of the first coating composition. Preferably, the second coating composition comprises wear resistance increasing particles and / or scratch resistance increasing particles. Preferably, these particles comprises or consist of aluminum oxide particles, diamond particles or silicon carbide particles. Preferably, the first coating composition does not comprise scratch resistance increasing particles.

[0108] In embodiments wherein the second coating composition comprises scratch resistant increasing particles, these particles preferably have an S50 particle size between 50% and 200% of the coating layer applied with the second coating composition.

[0109] In preferred embodiments of the invention, the second coating composition comprises a matting agent. This embodiment has the same benefit as explained at the first aspect of the invention.

[0110] The matting agent preferably provides between 2 and 14 wt%, and more preferably between 3 and 10 wt%, of the second coating composition. A preferred matting agent for use in the second coating composition is amorphous silica, preferably having S50 particle size between 3 and 20 micrometer. The S50 particle size is the particle size in the particle size distribution according to volume as determined using laser diffraction at which 50% of the particles are smaller than the S50. Amorphous silica has shown good compatibility with the acrylate coating composition.

[0111] The first coating composition as well as the second coating composition can be coating compositions as in any embodiment of the first aspect of the invention. Preferably, the first coating compositions differs from the second coating composition.

[0112] The third aspect of the invention relates to a sheet comprising a coating layer. The sheet is characterized in that the coating layer is an acrylate and / or methacrylate coating layer cured to B-stage. The surface of the coating layer is not tacky. The surface of the coating layer is wrinkled. The weight of the coating layer on the sheet is between 30 (and preferably at least 100) and 300 gram per square meter. The B-stage coating layer comprises one or more thermo initiators.

[0113] It is a benefit of such sheet that it can be thermally pressed wherein the coating layer is thermally cured and wherein the coating layer is embossed, e.g. by coping the structured surface of the press element or by using an embossed film between the press element and the coating layer. The thermal pressing operation can also involve laminating the sheet onto a board, e.g. a wood-based board such as a wood fiber board, a wood chip board or a oriented strand board (OSB), or onto a mineral based board (e.g. a magnesium oxide based board), or onto a board based on a thermoplastic matrix (e.g. a polyvinyl chloride based board); or onto a plurality of resin impregnated kraft paper sheets.

[0114] The sheet of the third aspect of the invention can be obtained using any embodiment of a method according to the second aspect of the invention.

[0115] The sheet of the third aspect of the invention can comprise a coating layer obtained using an acrylate coating composition as in any embodiment of the first aspect of the invention. A preferred sheet is characterized in that the sheet comprises a printed paper sheet and that the coating layer is provided on the printed paper sheet. Such embodiments have the benefit that the coating layer - also after final curing - is provided with a decorative printed image. In a thermal pressing operation, the coating layer can be provided with an embossed structure in register with the printed decor of the printed paper sheet. This allows the imitation of real wood.

[0116] The printed paper sheet may be provided with thermoset resin, preferably a B-stage thermoset resin . Such thermoset resin can be a melamine formaldehyde resin, an acrylate resin or a polyurethane resin, or combinations thereof. Resin combinations can comprise mixtures of resins or resin combinations can be provided via layers of different resins.

[0117] Use of a printed paper sheet impregnated with B-stage thermoset resin enables that the sheet can be thermally laminated in a pressing operation. In the same pressing operation, the B-stage coating layer of the sheet can be thermally cured and can be provided with an embossed structure.

[0118] The sheet can comprise a plastic film - e.g. a printed plastic film or a transparent unprinted plastic film -, wherein the coating layer is provided on the plastic film. The plastic film can be selected from a polyvinyl chloride film, a thermoplastic polyurethane film, a polypropylene film, a polyester film or a poly(methyl methacrylate) film. Such embodiments have the benefit that the sheet can be laminated to a plastics board, e.g. in a thermal pressing operation in which the B-stage coating layer is cured and optionally provided with an embossed structure.

[0119] The sheet of the third aspect of the invention optionally comprises a polyurethane layer at the opposite side of the side comprising the coating layer. The polyurethane layer can be beneficial for laminating the sheet to a substrate in a thermal pressing step in which the sheet is laminated to a substrate and during which the coating layer is thermally cured and optionally provided with an embossed structure, preferably in register with a printed decor of the sheet if present. A preferred sheet according to the third aspect is characterized in that the sheet comprises a polyurethane layer, a melamine-formaldehyde resin layer, a urea-formaldehyde resin layer, or a layer comprising a combination of such resins; or a resin impregnated paper sheet or nonwoven web - preferably wherein the resin is selected from polyurethane, melamine formaldehyde or urea-formaldehyde - at the side opposite to the side comprising the coating layer. Such layers can be beneficial for laminating the sheet to a substrate in a thermal pressing step in which the sheet is laminated to a substrate and during which the coating layer is thermally cured and optionally provided with an embossed structure, preferably in register with a printed decor of the sheet if present.

[0120] A preferred sheet is characterized in that less than 60% of the acrylate double bonds at the surface of the coating layer have been converted, as measured using FTIR / ATR using a diamond crystal.

[0121] A preferred sheet is characterized in that the acrylate coating layer is in a condition such that in a thermal pressing operation the acrylate coating layer can be cured and provided with embossments including gloss differences by copying the texture of the press element used in the thermal pressing operation.

[0122] A preferred sheet is characterized in that the coating layer comprises a matting agent, preferably wherein the matting agent provides between 2 and 14 wt% - and more preferably between 3 and 10 wt% - of the coating layer.

[0123] The matting agent preferably is an amorphous silica, more preferably having S50 particle size according to volume between 3 and 20 micrometer.

[0124] The fourth aspect of the invention relates to a board. The board comprises a coating layer. The coating layer is an acrylate and / or methacrylate coating layer cured to B-stage. The surface of the coating layer is not tacky. The surface of the coating layer is wrinkled. The weight of the coating layer on the board is between 30 (and preferably at least 100) and 300 gram per square meter. The coating layer comprises one or more thermo initiators. It is a benefit of such board that it can be thermally pressed wherein the coating layer is thermally cured and wherein the coating layer is embossed, e.g. by coping the structured surface of the press element or by using an embossed film between the press element and the coating layer.

[0125] The board of the fourth aspect of the invention can be obtained using any embodiment of a method according to the second aspect of the invention.

[0126] The board of the fourth aspect of the invention can comprise a coating layer obtained using an acrylate coating composition as in any embodiment of the first aspect of the invention.

[0127] A preferred board of the fourth aspect of the invention is characterized in that less than 60% of the acrylate double bonds at the surface of the coating layer have been converted, as measured using FTIR / ATR using a diamond crystal.

[0128] A preferred board is characterized in that the coating layer comprises a matting agent, preferably wherein the matting agent provides between 2 and 14 wt% - and more preferably between 3 and 10 wt% - of the coating layer.

[0129] The matting agent preferably is an amorphous silica, more preferably having S50 particle size according to volume between 3 and 20 micrometer.

[0130] A preferred board of the fourth aspect of the invention is characterized in that the acrylate coating layer is in a condition such that in a thermal pressing operation the acrylate coating layer can be cured and provided with embossments including gloss differences by copying the texture of the press element used in the thermal pressing operation.

[0131] The board preferably comprises a printed board, e.g. a printed wood-based board, or a printed mineral board or a printed - whether or not filled - plastics board, wherein the coating layer is provided on the printed board. Such embodiments have the benefit that the board - also after final curing of the coating layer - is provided with a decorative printed image. In a thermal pressing operation - during which the B-stage coating layer can be thermally cured the coating layer can be provided with an embossed structure in register with the printed decor of the printed board. This allows the imitation of real wood.

[0132] The printed board can e.g. be printed wood-based board such as a wood fiber board, a wood chip board or a oriented strand board (OSB), or a printed mineral based board (e.g. a magnesium oxide based board) or a printed board based on a thermoplastic matrix (e.g. a polyvinyl chloride based board).

[0133] In more preferred embodiments of the third aspect or of the fourth aspect of the invention, the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than than the 60 seconds half-life temperature of the first thermo initiator. Such embodiments have the same benefits as mentioned for the first aspect and / or the second aspect of the invention.

[0134] In more preferred embodiments of the third aspect or of the fourth aspect of the invention, the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the second thermo initiator. Such embodiments have the same benefits as mentioned for the first aspect and / or the second aspect of the invention.

[0135] In more preferred embodiments of the third aspect or of the fourth aspect of the invention, the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C (and preferably at least 10°C, and more preferably at least 15°C) higher than the 60 seconds half-life temperature of the third thermo initiator. Such embodiments have the same benefits as mentioned for the first aspect and / or the second aspect of the invention. In preferred embodiments of the third aspect or of the fourth aspect of the invention, the coating layer comprises silica (SiCh) , preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% of the coating composition. Such embodiments have the same benefits as mentioned for the first aspect and / or the second aspect of the invention.

[0136] In preferred embodiments of the third aspect or of the fourth aspect of the invention, the coating layer comprises AI2O3, preferably in an amount more than 0.05 wt% of the total coating composition, and preferably in an amount less than 7 wt% (and more preferably less than 2 wt%) of the coating composition. Such embodiments can be performed as mentioned at the first aspect or the second aspect of the invention, and have the same benefits as mentioned for the first aspect and / or the second aspect of the invention.

[0137] In preferred embodiments of the third aspect or of the fourth aspect of the invention, the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica. Such embodiments can be performed as mentioned at the first aspect or the second aspect of the invention, and have the same benefits as mentioned for the first aspect and / or the second aspect of the invention.

[0138] In preferred embodiments of the third aspect or of the fourth aspect of the invention, the B-stage coating layer or the sheet has a moisture content and / or volatile organic compounds content less than 8 wt%, preferably less than 6 wt%, as measured by determining the weight of the board before and after exposing the board during 5 minutes to a temperature of 160°C. Such embodiments have the benefit that further processing of the sheet or board can be done in an easy and effective way.

[0139] In preferred embodiments of the third aspect or of the fourth aspect of the invention, the coating layer is between 30 (and preferably at least 50) and 400 micrometer thick, preferably more than 150 micrometer thick, more preferably more than 250 micrometer thick. Such embodiments have the benefit that after thermal curing of the B-stage coating layer a coating layer with excellent abrasion resistance is obtained and that in the thermal curing via thermal pressing, the surface can be provided with an embossed structure thanks to the thickness of the B-stage coating layer.

[0140] The fifth aspect of the invention relates to a method for manufacturing a decorative panel. The method comprises the steps of

[0141] - providing a substrate;

[0142] - placing a sheet as in any embodiment of the third aspect of the invention on the substrate;

[0143] - pressing the combination of the substrate and the sheet in a heated press element, thereby laminating the sheet onto the substrate and preferably providing by said pressing at least the coating layer of the sheet with an embossed structure.

[0144] This method allows to obtain a decorative panel having excellent abrasion resistance.

[0145] Preferably, the pressing operation is performed with a pressure between 10 and 100 g / cm2.

[0146] Preferably, the pressing operation in the heated press element is performed during 5 to 400 seconds and / or at between 120 and 220 °C.

[0147] The coating layer can be thermally cured in the pressing step.

[0148] A preferred embodiment of the fifth aspect of the invention is characterized in that the sheet comprises a printed paper sheet or a printed thermoplastic film; and in that in the pressing operation at least the coating layer is provided with an embossed structure in register with the print of the printed decor. It is a benefit of such embodiment that a panel can be obtained that shows a realistic imitation of a natural product, e.g. of wood. The decorative panel obtained can e.g. be a floor panel the surface of which showing a realistic imitation of a wood panel.

[0149] The pressings step can be performed in a single daylight press, or in a multiple daylight press, or in a short cycle press, or in a continuous press, or in a - preferably continuous

[0150] - lamination line. The pressing step can be performed using a structured press element or a structured film, wherein the structure of the structured press element or the structured film provides the coating layer of the sheet with an embossed structure. The embossed structure can be provided in register with a printed decor.

[0151] The substrate can be selected from a wood-based board, a wood fiber board, a wood chip board, a mineral board - e.g. a magnesium oxide based board -, a - whether or not filled - plastic board (preferably a - whether or not filled - thermoplastic board), or a plurality of resin impregnated kraft paper sheets.

[0152] The sheet used in the fifth aspect of the invention preferably comprises a polyurethane layer at the opposite side of the side comprising the coating layer. The polyurethane layer can be beneficial for laminating the sheet to the substrate in the pressing step.

[0153] The substrate can comprise a polyurethane layer onto which the sheet is applied. The polyurethane layer can be beneficial for laminating the sheet to the substrate in the pressing step.

[0154] In a preferred method of the fifth aspect of the invention a polyurethane layer or a web - e.g. a paper sheet or a nonwoven web - impregnated with polyurethane is positioned between the substrate and the sheet. The polyurethane layer or the web impregnated with polyurethane can be beneficial for laminating the sheet to the substrate in the pressing step.

[0155] Alternatively a melamine formaldehyde resin layer, a urea-formaldehyde resin layer or combinations thereof can be used instead of polyurethane; or a paper sheet or a nonwoven web impregnated a melamine formaldehyde resin, with a urea-formaldehyde resin or with combinations thereof can be positioned between the substrate and the sheet. It is a benefit of such embodiments that better lamination of the sheet to a substrate in the pressing step is obtained. In a preferred method according to the fifth aspect of the invention the sheet comprises a polyurethane layer, a melamine-formaldehyde resin layer, a urea-formaldehyde resin layer, or a layer comprising a combination of such resins; or a resin impregnated paper sheet or nonwoven web - preferably wherein the resin is selected from polyurethane, melamine formaldehyde or urea-formaldehyde - at the side opposite to the side comprising the coating layer at the opposite side of the side comprising the coating layer. Such embodiments provide improved adhesion of the sheet to the substrate in the pressing step.

[0156] In a preferred method according to the fifth aspect of the invention the substrate comprises a polyurethane layer, a melamine-formaldehyde resin layer, or a urea- formaldehyde resin layer onto which the sheet is applied. Such embodiments provide improved adhesion of the sheet to the substrate in the pressing step.

[0157] A preferred method according to the fifth aspect of the invention comprises the step of positioning a glue sheet between the substrate and the sheet; preferably wherein the glue sheet comprises a resin impregnated paper sheet or nonwoven web, more preferably wherein the resin is selected from polyurethane, melamine formaldehyde, urea- formaldehyde or combinations thereof. Such embodiments provide improved adhesion of the sheet to the substrate in the pressing step.

[0158] A preferred method according to the fifth aspect of the invention is characterized in that in the pressing operation the coating layer is provided with its gloss levels - and optionally with different gloss levels over the surface of the coating layer - by copying the texture of the heated press element.

[0159] It means that the microstructure present at the surface of the coating layer prior to the pressing operation in the heated press element is destroyed in the pressing operation and replaced by copying the texture of the heated press element. Thus, the coating layer obtains its embossed structure, as well as its gloss levels as determined by a microstructure, by copying the texture of the heated press element. This way, the gloss level(s) can be obtained independent from the gloss level of the surface of the coating layer before the pressing operation.

[0160] In a preferred embodiment, the coating layer is in the pressing operation in at least a section of its surface - and preferably over its full surface - provided with a gloss level less than 1.9 as measured under an angle of 60°.

[0161] A preferred method is characterized in that one or two of the following options applies:

[0162] - option 1 : the coating layer is provided in the pressing operation with a gloss that differs over the surface of the coating layer less than 2 points, wherein the gloss is measured under an angle of 60°;

[0163] - option 2: the coating layer is provided in the pressing operation with different gloss levels over the surface of the coating, wherein the difference between the highest gloss and the lowest gloss is more than 2 points, wherein the gloss is measured under an angle of 60°;

[0164] - option 3 : the coating layer is provided in the pressing operation with different gloss levels over the surface of the coating, wherein the different gloss levels are provided in register with the printed decor.

[0165] The combination of options 2 and 3 is of particular interest, as it allows to produce panels with a very realistic imitation of a wood panel.

[0166] When measurements of gloss levels are mentioned, meant is measurement of gloss according to ASTM D 523 (2018) under a reflection angle of 60°.

[0167] With the intention of better showing the characteristics of the invention, hereafter, as an example without any limitative character, several preferred embodiments are described, with reference to the accompanying drawings, wherein: figure 1 illustrates a method according to aspects of the invention for curing a coating composition to B-stage; figure 2 shows a method according to aspects of the invention for manufacturing a decorative panel; and figure 3 shows a decorative panel obtained according to aspects of the invention.

[0168] Figure 1 illustrates an example of a method according to aspects of the invention for curing a coating composition to B-stage.

[0169] A coating composition 22 is applied on printed paper sheet 10 impregnated with a thermoset resin cured to B-stage. The coating composition 22 is applied in an amount of 200 g / m2of the printed paper sheet 10. The coating composition comprises:

[0170] (A) one or more acrylate and / or methacrylate oligomers. The oligomers have a molar mass equal to or higher than 800 g / mol and preferably lower than 4500 g / mol;

[0171] (B) one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents having a molar mass lower than 800 g / mol;

[0172] (C) one or more photo initiators; and

[0173] (D) a first thermo initiator, a second thermo initiator, a third thermo initiator and a fourth thermo initiator.

[0174] The coating composition 22 can be a coating composition as in any embodiment of the first aspect of the invention.

[0175] The first thermo initiator has a 60 seconds half-life of 130°C. The second thermo initiator has a 60 seconds half-life temperature of 150°C. The third thermo initiator has a 60 seconds half-life temperature of 165°C. The fourth thermo initiator has a 60 seconds halflife temperature of 177°C.

[0176] A first UV-radiation step 26, 28 is applied to the carrier with the coating composition. In this first UV-radiation step, the printed paper sheet 10 with the coating composition 22 applied on it consecutively passes two UV-lamps 26, 28.

[0177] A second UV-radiation is performed step by passing the printed paper sheet 10 with the coating composition 22 on it under an excimer-type monochromatic radiation lamp 30. In the example shown, the monochromatic radiation lamp is a Xe2 excimer lamp emitting UV radiation at 172 nm wavelength. A third UV-radiation step 32, 34 is applied to the carrier with the coating composition. In this third UV-radiation step, the printed paper sheet 10 with the coating composition 22 applied on it consecutively passes two UV-lamps 32, 34.

[0178] Obtained is a resin impregnated printed paper sheet (sheet 40) comprising a coating layer which is partially cured to B-stage and wherein the surface of the coating layer is not tacky, wrinkled and comprises micro folds caused by the excimer curing in the second UV-radiation step.

[0179] In the example shown, the first UV-radiation step 26, 28; the second UV-radiation step 30; and the third UV-radiation step 32, 34 are performed in-line and continuously.

[0180] As an alternative to the printed paper sheet 10, the coating composition can e.g. be applied on a plastic film or on a board having a printed decor.

[0181] Figure 2 shows an example of a method according to aspects of the invention for manufacturing a decorative panel. The method comprises the step of providing a substrate, e.g. a board 42, which can e.g. be a wood-based board, a wood fiber board, a wood chip board, a mineral board - e.g. a magnesium oxide based board -, a - whether or not filled - plastic board, preferably a - whether or not filled - thermoplastic board.

[0182] A sheet 40 as obtained in the method shown in figure 1 is placed on the board 42. The sheet 40 is a printed paper sheet impregnated with a thermoset resin can comprising a coating layer which is partially cured to B-stage and wherein the surface of the coating layer is not tacky, wrinkled and comprises micro folds.

[0183] A second paper sheet 44 impregnated with a thermoset resin can be positioned at the other side of the board 42.

[0184] The stack of the sheet 40, the board 42 and the second paper sheet 44 is pressed at elevated temperature in a single daylight press 50. The press element of the singe daylight press 50 is in the example shown a structured press element 52. In the single daylight press 50, the printed paper sheet 40 and the second paper sheet 44 are laminated to the board 40 thanks to the resins with which the printed paper sheet 40 and the second paper sheet 44 are impregnated. In the single daylight press, the coating layer of the printed paper sheet 40 is embossed in which the texture of the structured press element 50 is copied and the coating layer is thermally cured. Using an appropriate structured press element 52 and correct positioning of the printed paper sheet 40, an embossment in register with the printed design of the printed paper sheet 40 can be obtained. The press element can also provide a pressed bevel to the decorative panel.

[0185] The second paper sheet 44 can provide a balancing layer to the decorative panel which is obtained in the described thermal pressing operation.

[0186] With the method of figure 2, a decorative panel 60 as shown in figure 3 can be obtained. The decorative panel comprises a board 42, a resin impregnated printed paper sheet 40 having a coating layer. The decorative panel is embossed with a texture in register with the printed decor of the printed paper sheet. The bottom of the decorative panel 60 shown in the example comprises an impregnated second paper sheet 44 acting as balancing layer.

[0187] An example of an acrylate coating composition according to the first aspect of the invention comprises:

[0188] 14.4 parts by weight of a trifunctional epoxy acrylate oligomer,

[0189] 35 parts by weight of a polyester methacrylate oligomer,

[0190] 15 parts by weight of an unsatured polyester acrylate oligomer,

[0191] 30 parts by weight of an acrylate reactive diluent having three acrylate functionalities,

[0192] 0.1 parts by weight of Omnirad 2100, which is a blend of Norrish type I photo initiators,

[0193] 0.2 parts by weight of Luperox 531M60 (Arkema) which is a 60% solution of l,l-di(tert-amylperoxy)-cyclohexane peroxide in isododecane. l,l-di(tert- amylperoxy)-cyclohexane peroxide is a thermo initiator having a 60 seconds halflife temperature of 152 °C.

[0194] 0.3 parts by weight of thermo initiator tert-butyl peroxy-3, 5, 5 -trimethylhexanoate (TBPIN - CAS 13122-18-4), which has a 60 seconds half-life temperature of 160°C.

[0195] 0.3 parts by weight of thermo initiator 2-5-dimethyl-2-5-di-tert-butylperoxy- hexane, which has a 60 seconds half-life temperature of 177 °C.

[0196] 0.3 parts by weight of thermo initiator 2,5-dimethyl-2,5-bis(t-butyl peroxy)hexyne-3,85% solution in white oil. This thermo initiator has a 60 seconds half-life temperature of 194°C.

[0197] Coating layers have been applied on a melamine and acrylate resin impregnated printed paper sheet using 200 g / m2of this acrylate coating composition. The coating layer has been partially cured (pre- gelled) to B-stage using a first UV-radiati on step, a second UV- radiation step and a third UV-radiation step. The three UV-radiation steps have been performed in line and continuously. A Hg, a Ga or a Fe doped UV-radiation lamp can be used in the first UV-radiation step. The second UV-radiation step has been performed under inert atmosphere by a Xe2 excimer lamp (emitting monochromatic radiation at 172 nm wavelength). The third UV-radiation step has been performed by passing the coated printed paper sheet consecutively under two Ga or two iron doped UV lamps. This partial curing (pre-gelling) process resulted in a B-stage coating layer being non-tacky and the surface of which was wrinkled and comprising micro folds.

[0198] A single day light press with structured press element has been used to laminate using pressure and increased temperature the coated resin impregnated printed sheet of paper onto a High Density Fiberboard (HDF) in which the resin of the resin of the resin impregnated printed sheet of paper was cured. In the same pressing operation at 210°C during 20 seconds, the texture of the structured press element was copied into the acrylate coating layer and the acrylate coating layer was thermally cured. It has been observed that the texture of the structured press element was nicely copied at the surface of the laminate and that the acrylate coating layer was well cured. In another example, 200 gram per square meter of the coating composition of the previous example has been applied on a transparent polyvinyl chloride film of 100 micrometer thick. The obtained coating layer has been partially cured (pre-gelled) in the same way as in the previous example. An SPC (Solid Plastic Composite) polyvinyl chloride substrate (which comprises a polyvinyl chloride matrix and mineral fillers) was used as substrate, on top of which a 80 micrometer polyvinyl chloride film provided with a printed decor has been stacked, and on top of which the transparent polyvinyl chloride film with the partially cured coating composition was stacked. In a pressing operation at elevated temperature, the stack has been pressed in which the substrate, polyvinyl chloride film provided with the printed decor and the transparent polyvinyl chloride film with the partially cured coating are laminated to each other; and in which the surface of the decorative panel obtained has been provided with a surface texture by copying the structure of the structured press element that was used at least into the coating layer. The present invention is in no way limited to the embodiments described as an example or represented in the figures, on the contrary it can be realized in various forms and dimensions, without leaving the scope of the invention.

Claims

Claims1.- Acrylate coating composition, wherein the coating composition comprises(A) one or more acrylate and / or methacrylate oligomers, preferably wherein said oligomers have a molar mass equal to or higher than 800 g / mol;(B) one or more acrylate reactive diluent and / or methacrylate reactive diluent and / or (meth)acrylamide reactive diluents; wherein said reactive diluents have a molar mass lower than 800 g / mol, and preferably lower than 500 g / mol;(C) one or more photo initiators; and(D) one or more thermo initiators; wherein the coating composition comprises photo initiators in a combined amount less than 1 wt% of the combination of the one or more acrylate and / or methacrylate oligomers (A) and the one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents (B).2.- Acrylate coating composition as in claim 1, characterized in that the one or more photo initiators comprise or consist of Norrish type I photo initiators.3.- Acrylate coating composition as in any of the preceding claims, characterized in that the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the first thermo initiator.4.- Acrylate coating composition as in claim 3, characterized in that the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C higher than the 60 seconds half- life temperature of the second thermo initiator.5.- Acrylate coating composition as in claim 4, characterized in that the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-lifetemperature of the fourth thermo initiator is at least 8°C higher than the 60 seconds halflife temperature of the third thermo initiator.6.- Acrylate coating composition as in any of the preceding claims, characterized in that the coating composition comprises silica (SiCh), preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% of the coating composition.7.- Acrylate coating composition as in any of the preceding claims, characterized in that the coating composition comprises AI2O3, preferably with average particle size less than 30 micrometer, preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 7 wt% of the coating composition.8.- Acrylate coating composition as in any of the preceding claims, characterized in that the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica.9.- Acrylate coating composition as in any of the preceding claims, characterized in that the coating composition comprises wear resistant particles, e.g. corundum or silicon carbide, wherein the wear resistant particles have an average particle size between 40 and 100 micrometer.10.- Acrylate coating composition as in any of the preceding claims, characterized in that the acrylate coating composition comprises pigments and / or dyes, preferably in amount of 0.5 - 10 percent by weight.11.- Acrylate coating composition as in any of the preceding claims, characterized in that the acrylate coating composition comprises a matting agent, preferably wherein the matting agent provides between 2 and 14 wt% - and more preferably between 3 and 10 wt% - of the acrylate coating composition.12.- Acrylate coating composition as in claim 11, characterized in that the matting agent is an amorphous silica, preferably having S50 particle size according to volume between 3 and 20 micrometer.13.- Method for curing a coating layer to B-stage, wherein the method comprises the steps of- applying a coating composition on a carrier;- optionally applying a first UV-radiation step to the carrier with the coating composition;- applying a second UV-radiation step by passing the carrier with the coating composition on it under an excimer-type monochromatic radiation lamp; and- applying a third UV-radiation step to the carrier with the coating composition on it; thereby obtaining a carrier with a coating layer onto it, wherein the coating layer is provided by partial curing of the coating composition to B-stage; and wherein the surface of the coating layer is not tacky; wherein the coating composition - optionally a coating composition as in any of the preceding claims 1 - 12 - applied onto the carrier comprises(A) one or more acrylate and / or methacrylate oligomers, preferably wherein said oligomers have a molar mass equal to or higher than 800 g / mol and preferably lower than 4500 g / mol ;(B) one or more acrylate and / or methacrylate and / or (meth)acrylamide reactive diluents; wherein said reactive diluents have a molar mass lower than 800 g / mol, and preferably lower than 500 g / mol;(C) one or more photo initiators; and(D) one or more thermo initiators.14.- Method as in claim 13, characterized in that in the optional first UV-radiation step, when this step is performed, the carrier with the coating composition consecutively passes one or a plurality of UV-lamps.15.- Method as in any of the preceding claims 13 - 14, characterized in that the optional first UV-radiation step, when this step is performed, is at least partially performed using out-of-focus UV-lamps.16.- Method as in any of the preceding claim 13 - 15, characterized in that in the third UV-radiation step, the carrier with the coating composition consecutively passes a plurality of UV-lamps.17.- Method as in any of the preceding claims 13 - 16, characterized in that the thirdUV-radiation step is at least partially performed using out-of-focus UV-lamps.18.- Method as in any of the preceding claims 13 - 17, characterized in that the optional first UV-radiation step - when performed -, the second UV-radiation step, and the third UV-radiation step are performed in-line and continuously.19.- Method as in any of the preceding claims 13 - 18, characterized in that the surface of the coating layer obtained is wrinkled and / or comprises micro folds.20.- Method as in any of the preceding claims 13 - 19, characterized in that in the step of applying the coating composition on the carrier, between 30 - and preferably at least 100 - and 300 gram coating composition is applied per square meter.21.- Method as in any of the preceding claims 13 - 20, characterized in that in the step of applying the coating composition on the carrier, a coating layer between 30 (and preferably at least 50) and 400 micrometer thick is obtained.22.- Method as in any of the preceding claims 13 - 21, characterized in that the carrier comprises a printed paper sheet, preferably paper sheet provided with thermoset resin, more preferably wherein the thermoset resin comprises a melamine formaldehyde resin, an acrylate resin or a polyurethane resin, or combinations thereof.23.- Method as in any of the preceding claims 13 - 21, characterized in that the carrier comprises or consists of a plastic film - e.g. a printed plastic film or a transparent unprinted plastic film -, preferably wherein the plastic film is selected from a polyvinylchloride film, a thermoplastic polyurethane film, a polypropylene film, a polyester film or a poly(methyl methacrylate) film.24.- Method as in any of the preceding claims 13 - 23, characterized in that the carrier comprises or consists of a printed board, e.g. a printed wood-based board, or a printed mineral board or a printed - whether or not filled - plastics board.25.- Method as in any of the preceding claims 13 - 24, characterized in that the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the first thermo initiator.26.- Method as in claim 25, characterized in that the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the second thermo initiator.27.- Method as in claim 26, characterized in that the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the third thermo initiator.28.- Method as in any of the preceding claims 13 - 27, characterized in that the coating composition comprises silica (SiCh) , preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% of the coating composition.29.- Method as in any of the preceding claims 13 - 28, characterized in that the coating composition comprises AI2O3 particles, preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 7 wt% of the coating composition, preferably wherein the AI2O3 particles have an average particle size less than 30 micrometer.30.- Method as in any of the preceding claims 13 - 29, characterized in that the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica.31.- Method as in any of the preceding claims 13 - 30, characterized in that the optional first UV-radiation step is not performed in an inert atmosphere; or in that the optional first UV-radiation step is performed in an inert atmosphere, e.g. in a nitrogen atmosphere.32.- Method as in any of the preceding claims 13 - 31, characterized in that the second UV-radiation step and / or the third UV-radiation step is performed in an inert atmosphere, preferably under nitrogen atmosphere.33.- Method as in any of the preceding claims 13 - 32, characterized in that the coating layer is cured in the method to B-stage in which less than 60% of the acrylate double bonds at the surface of the coating layer are converted in the method, as measured using FTIR / ATR using a diamond crystal.34.- Method as in any of the preceding claims 13 - 33, characterized in that the step of applying a coating composition on a carrier, comprises the step of applying a first coating composition on the carrier and a second coating composition on the first coating composition, wherein the second coating composition provides on the carrier less than 40 wt% - and preferably less than 30 wt% - of the combination of the first coating composition and the second coating composition; wherein the first coating composition as well as the second coating composition comprise (meth)acrylate oligomers and (meth)acrylate reactive diluents.35.- Sheet comprising a coating layer, characterized in that the coating layer is an acrylate and / or methacrylate coating layer cured to B-stage, wherein the surface of the coating layer is not tacky, wherein the surface of the coating layer is wrinkled; wherein the weight of the coating layer on the sheet is between 30 - and preferably at least 100 - and 300 gram per square meter; wherein the coating layer comprises one or more thermoinitiators; preferably wherein the coating layer is obtained from a coating composition as in any of the claims 1 - 12; and / or wherein the sheet is obtained in a method as in any of the preceding claims 13 - 34.36.- Sheet as in claim 35, characterized in that the sheet comprises or consists of a printed paper sheet and that the coating layer is provided on the printed paper sheet, preferably wherein the paper sheet is provided with thermoset resin - preferably a B- stage thermoset resin -, more preferably wherein the thermoset resin comprises a melamine formaldehyde resin, an acrylate resin or a polyurethane resin, or combinations thereof.37.- Sheet as in in claim 35, characterized in that the sheet comprises a plastic film - e.g. a printed plastic film or a transparent unprinted plastic film - and that the coating layer is provided on the plastic film, preferably wherein the plastic film is selected from a polyvinyl chloride film, a thermoplastic polyurethane film, a polypropylene film, a polyester film or a poly(methyl methacrylate) film38.- Sheet as in any of the preceding claims 35 - 37, characterized in that the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator, wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the first thermo initiator.39.- Sheet as in claim 38, characterized in that the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the second thermo initiator.40.- Sheet as in claim 39, characterized in that the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the third thermo initiator.41.- Sheet as in any of the preceding claims 35 - 39, characterized in that the coating layer comprises silica (SiCh) , preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% of the coating composition.42.- Sheet as in any of the preceding claims 35 - 41, characterized in that the coating layer comprises AI2O3 , preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 7 wt% of the coating composition.43.- Sheet as in any of the preceding claims 35 - 42, characterized in that the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica.44.- Sheet as in any of the preceding claims 35 - 43, characterized in that the coating layer comprises a matting agent, preferably wherein the matting agent provides between 2 and 14 wt% - and more preferably between 3 and 10 wt% - of the coating layer.45.- Sheet as in claim 44, characterized in that the matting agent is an amorphous silica, preferably having S50 particle size according to volume between 3 and 20 micrometer.46.- Sheet as in any of the preceding claims 35 - 45, characterized in that the B-stage coating layer or the sheet has a moisture content and / or volatile organic compounds content less than 8 wt%, preferably less than 6 wt%, as measured by determining the weight of the sheet before and after exposing the sheet during 5 minutes to a temperature of 160°C.47.- Sheet as in any of the preceding claims 35 - 46, characterized in that the coating layer is between 30 and 400 micrometer thick, preferably more than 150 micrometer thick, more preferably more than 250 micrometer thick.48.- Sheet as in any of the preceding claims 35 - 47, characterized in that the sheet comprises a polyurethane layer, a melamine-formaldehyde resin layer, a ureaformaldehyde resin layer, or a layer comprising a combination of such resins; or a resin impregnated paper sheet or nonwoven web - preferably wherein the resin is selected from polyurethane, melamine formaldehyde or urea-formaldehyde - at the side opposite to the side comprising the coating layer.49.- Sheet as in any of the preceding claims 35 - 48, characterized in that less than 60% of the acrylate double bonds at the surface of the coating layer have been converted as measured using FTIR / ATR using a diamond crystal.50.- Sheet as in any of the preceding claims 35 - 49, characterized in that the acrylate coating layer is in a condition such that in a thermal pressing operation the acrylate coating layer can be cured and provided with embossments including gloss differences by copying the texture of the press element used in the thermal pressing operation.51.- Board comprising a coating layer, characterized in that the coating layer is an acrylate and / or methacrylate coating layer cured to B-stage, wherein the surface of the coating layer is not tacky, wherein the surface of the coating layer is wrinkled; wherein the weight of the coating layer on the board is between 30 - and preferably at least 100 - and 300 gram per square meter; wherein the coating layer comprises one or more thermo initiators; preferably wherein the coating layer is obtained from a coating composition as in any of the claims 1 - 12; and / or wherein the sheet is obtained in a method as in any of the preceding claims 13 - 36.52.- Board as in claim 51, characterized in that the board comprises a printed board, e.g. a printed wood-based board, or printed mineral board or a printed - whether or not filled - plastics board, wherein the coating layer is provided on the printed board.53.- Board as in any of the preceding claims 51 - 52, characterized in that the one or more thermo initiators comprise a first thermo initiator and a second thermo initiator,wherein the 60 seconds half-life temperature of the second thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the first thermo initiator.54.- Board as in claim 53, characterized in that the one or more thermo initiators comprise a third thermo initiator, wherein the 60 seconds half-life temperature of the third thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the second thermo initiator.55.- Board as in claim 54, characterized in that the one or more thermo initiators comprise a fourth thermo initiator, wherein the 60 seconds half-life temperature of the fourth thermo initiator is at least 8°C higher than the 60 seconds half-life temperature of the third thermo initiator.56.- Board as in any of the preceding claims 51 - 55, characterized in that the coating layer comprises silica (SiCh) , preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 3 wt% of the coating composition.57.- Board as in any of the preceding claims 51 - 56, characterized in that the coating layer comprises AI2O3, preferably in an amount more than 0.05 wt% of the total coating composition, and preferably less than 7 wt% of the coating composition.58.- Board as in any of the preceding claims 51 - 57, characterized in that the coating composition comprises wear resistant particles, e.g. corundum, silicon carbide, diamond or nanosilica.59.- Board as in any of the preceding claims 51 - 58, characterized in that the B-stage coating layer has a moisture and / or volatile organic compounds content less than 8 wt%, preferably less than 6 wt%, as measured by determining the weight of the board before and after exposing the board during 5 minutes to a temperature of 160°C.60.- Board as in any of the preceding claims 51 - 59, characterized in that the coating layer is between 30 (and preferably at least 50) and 400 micrometer thick, preferably more than 150 micrometer thick, more preferably more than 250 micrometer thick.61.- Board as in any of the preceding claims 51 - 60, characterized in that less than 60% of the acrylate double bonds at the surface of the coating layer have been converted as measured using FTIR / ATR using a diamond crystal.62.- Board as in any of the preceding claims 51 - 61, characterized in that the coating layer comprises a matting agent, preferably wherein the matting agent provides between 2 and 14 wt% - and more preferably between 3 and 10 wt% - of the coating layer.63.- Board a in claim 62, characterized in that the matting agent is an amorphous silica, preferably having S50 particle size according to volume between 3 and 20 micrometer.64.- Board as in any of the preceding claims 51 - 63, characterized in that the acrylate coating layer is in a condition such that in a thermal pressing operation the acrylate coating layer can be cured and provided with embossments including gloss differences by copying the texture of the press element used in the thermal pressing operation.65.- Method for manufacturing a decorative panel, wherein the method comprises the steps of- providing a substrate;- placing a sheet as in any of the preceding claims 35 - 50 on the substrate;- pressing the combination of the substrate and the sheet in a heated press element, thereby laminating the sheet onto the substrate and preferably providing by said pressing at least the coating layer of the sheet with an embossed structure.66.- Method as in claim 65, characterized in that in the pressing step, the coating layer is thermally cured.67.- Method as in any of the preceding claims 65 - 66, characterized in that the sheet comprises a printed paper sheet or a printed thermoplastic film and in that in the pressing operation at least the coating layer is provided with an embossed structure in register with the print of the printed decor.68.- Method as in any of the preceding claims 65 - 67, characterized in that said pressing is performed in a single daylight press, or in a multiple daylight press, or in a short cycle press, or in a continuous press, or in a - preferably continuous - lamination line.69.- Method as in any of the preceding claims 65 - 68, characterized in that said pressing is performed using a structured press element or a structured film, wherein the structure of the structured press element or the structured film provides the coating layer of the sheet with an embossed structure.70.- Method as in any of the preceding claims 65 - 69, characterized in that the substrate is selected from a wood-based board, a wood fiber board, a wood chip board, a mineral board - e.g. a magnesium oxide based board -, a - whether or not filled - plastic board, preferably a - whether or not filled - thermoplastic board, or a plurality of resin impregnated kraft paper sheets.71.- Method as in any of the preceding claims 65 - 70, characterized in that the sheet comprises a polyurethane layer, a melamine-formaldehyde resin layer, a ureaformaldehyde resin layer, or a layer comprising a combination of such resins; or a resin impregnated paper sheet or nonwoven web - preferably wherein the resin is selected from polyurethane, melamine formaldehyde or urea-formaldehyde - at the side opposite to the side comprising the coating layer at the opposite side of the side comprising the coating layer.72.- Method as in any of the preceding claims 65 - 71, characterized in that the substrate comprises a polyurethane layer, a melamine-formaldehyde resin layer, or a urea-formaldehyde resin layer onto which the sheet is applied.73 Method as in any of the preceding claims 65 - 72, characterized in that the method comprises the step of positioning a glue sheet between the substrate and the sheet; preferably wherein the glue sheet comprises a resin impregnated paper sheet or nonwoven web, more preferably wherein the resin is selected from polyurethane, melamine formaldehyde, urea-formaldehyde or combinations thereof.74.- Method as in any of the preceding claims 65 - 73, characterized in that in the pressing operation the coating layer is provided with its gloss levels - and optionally with different gloss levels over the surface of the coating layer - by copying the texture of the heated press element.75.- Method as in claim 74, characterized in that the coating layer is in the pressing operation in at least a section of its surface - and preferably over its full surface - provided with a gloss level less than 1.9 as measured under an angle of 60°.76.- Method as in any of the preceding claims 74 - 75, characterized in that one or two of the following options applies:- option 1 : the coating layer is provided in the pressing operation with a gloss that differs over the surface of the coating layer less than 2 points, wherein the gloss is measured under an angle of 60°;- option 2: the coating layer is provided in the pressing operation with different gloss levels over the surface of the coating, wherein the difference between the highest gloss and the lowest gloss is more than 2 points, wherein the gloss is measured under an angle of 60°;- option 3 : the coating layer is provided in the pressing operation with different gloss levels over the surface of the coating, wherein the different gloss levels are provided in register with the printed decor.

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