Method for producing decorative element comprising artificial stone and decorative element comprising artificial stone

Abstract

A method for manufacturing a decorative element comprising a substrate and a top layer wherein the substrate is made of artificial stone and the top layer comprises a decorative pattern, the method comprising the steps of: providing a mixture comprising at least an inorganic filler and a binder; compacting the mixture; curing the adhesive to obtain the substrate; and wherein the method comprises the step of inkjet printing a first decorative pattern on at least the top surface of the substrate wherein the ink is a thermocuring ink, such as a sublimation ink, wherein the method preferably comprises the step of curing the printed ink by exposing the printed substrate to heat, wherein the method comprises the step of providing a protective coating over the first decorative pattern.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a decorative element comprising engineered stone and a decorative element comprising engineered stone. The decorative element of the present invention is of the type comprising a substrate and a top layer, wherein the substrate is made of engineered stone and wherein the top layer comprises a decorative pattern. Specifically, the engineered stone of the present invention is commonly known in the market as quartz. Background Art

[0002] Engineered stone comprises inorganic fillers such as crushed stone, sand or other minerals, and recycled ceramics or glass bonded by a curing resin. More specifically, engineered stone refers to a composite material formed by bonding inorganic fillers or stone-like materials together with a curing binder cured at a low temperature, where the low temperature refers to a temperature below 500 °C. The binder is preferably a thermosetting resin.

[0003] Traditionally, natural stone has been used as a building material, especially for decorating buildings, for example, for covering walls or floors, and for producing worktops such as kitchen or bathroom countertops and dressers. Natural stone is mined from quarries and subsequently cut and polished to obtain slabs or billets of the desired shape. Due to quarrying, natural stone is relatively expensive and has a greater environmental impact.

[0004] Therefore, in the past few years, methods for manufacturing engineered stone have been developed in order to reduce costs and provide more environmentally friendly products. A well-known example of such a method is represented, for example, by the technique described in document WO 2007 / 138529. The document discloses a method for manufacturing engineered stone, which method comprises the steps of: providing a mineral filler by, for example, grinding sand or quartz; mixing the stone or stone-like material with a binder such as resin powder to obtain a mixture; depositing the mixture in a press mold having a shape and dimensions similar to the final product; applying a vacuum to press the mixture and applying a vibratory motion at a preset frequency; then hardening the obtained semi-finished product by a thermal curing method to obtain engineered stone; and then performing finishing steps such as cutting or polishing on the engineered stone.

[0005] This artificial stone usually includes monochromatic decoration. Alternatively, the artificial stone includes decoration including artificial textures that mimic natural stones such as marble or granite. As disclosed in WO 2009 / 010406, this kind of decoration is obtained by adding a colorant to the mixture before the mixture is deposited in the mold. The mixture is carried by an endless belt above the mold and self-loads into the mold by freely falling from the end of the belt. The colorant is loaded onto the surface of the mixture substantially corresponding to the end of the belt through a suitable nozzle, so that it falls into the mold together with the mixture in an uncontrolled manner. After the vibration-compression step, the pigment particles are distributed in the mixture, thereby generating a texture effect throughout the thickness of the artificial stone. Therefore, using this technique, it is impossible to obtain an artificial stone with a reproducible and predetermined decoration.

[0006] WO 2016 / 113652 discloses an apparatus and method for creating programmable color effects in artificial stone by a computer-controlled machine. The machine is an anthropomorphic robot or a Cartesian robot, equipped with one or more nozzles for dispensing a colorant on the surface of the mixture in a temporary support. The nozzle is connected to a tool that interacts with the surface of the mixture to create grooves or holes to receive the color so as to mimic the marble texture. Therefore, this apparatus requires machining of the mixture and provides an imitation natural stone decoration with relatively low resolution. This technique is slower and also has limitations in the size of the imitation texture that can be mimicked. In addition, it should be noted that the generated pattern will be affected by vibration and compaction, so that the final pattern is always different from the starting predetermined pattern.

[0007] WO2019070621 discloses a method for improving the aesthetic quality of artificial stone by inkjet printing decoration on the main surface of the stone. Summary of the Invention

[0008] The primary object of the present invention is to provide an alternative and improved method for manufacturing artificial stone, according to several preferred embodiments of which, the method aims to solve one or more problems arising in the prior art.

[0009] Furthermore, according to its first independent aspect, the present invention relates to a method for manufacturing a decorative element, the decorative element including a substrate and a top layer, wherein the substrate is made of artificial stone and wherein the top layer includes a decorative pattern, the method comprising the following steps:

[0010] - Providing a mixture comprising at least an inorganic filler and a binder;

[0011] - Compacting the mixture;

[0012] - Curing the binder to obtain the substrate;

[0013] And wherein the method comprises the step of inkjet printing a first decorative pattern on at least the top surface of the substrate.

[0014] The artificial stone can be manufactured in any desired form, but preferably in a substantially planar shape such as a slab, tile or slab. The artificial stone is preferably formed into a slab, wherein the slab is envisioned to be generally rectangular and planar in shape, preferably including a surface of at least 1.5 square meters. In this way, the artificial stone is made large enough to be versatile and suitable for cutting into dimensions and shapes according to the ultimate purpose of the artificial stone itself, such as, for example, kitchen or bathroom countertops. According to a preferred embodiment, the slab has a length of at least 2 m, preferably at least 2.5 m, for example 3 m or greater and a width of at least 1 m, preferably 1.5 m or greater. Additionally, the slab preferably exhibits a thickness of at least 10 mm, preferably at least 20 mm, for example 30 mm.

[0015] In a preferred embodiment, the inorganic filler comprises mineral materials such as any kind of stone, sand, siliceous mineral materials (e.g., quartz, silica sand, clay, feldspar, cristobalite, granite, talc) or calcareous mineral materials (e.g., calcium carbonate, marble, gypsum). The inorganic filler may also comprise ceramics, glass, metals and other inorganic materials, such as recycled materials. The filler can be in the form of powder, granules, shards, grains, aggregates or any other particulate form, but the granular and powder forms are preferred. The preferred filler is in the form of a powder with an average particle size below 45 μm, preferably below 20 μm. The filler preferably comprises at least 80 wt%, preferably more than 85 wt%, more preferably more than 90 wt% of the mixture. According to another embodiment of the present invention, the filler can be in the form of aggregates, grains and / or granules having a particle size distribution of 0.1 - 6.5 mm, preferably 0.1 - 2 mm, 0.1 - 0.7 mm. In the most preferred embodiment of the present invention, the filler consists of a combination of powder and granules, for example, the combination can comprise at least 60 wt% of granules and / or granules and 20 wt% - 35 wt% in the form of powder, wherein, for example, the granules have a particle size distribution of 0.1 - 6.5 mm, while the powder has an average particle size below 45 μm, preferably below 20 μm. In the most preferred embodiment of the present invention, most of the filler, i.e., at least 50 wt%, consists of silicon (Si)-based inorganic materials, and more preferably mainly consists of them. Silicon-based materials, such as siliceous minerals and glass, exhibit good affinity with the binder, thereby improving the final adhesion.

[0016] In some embodiments, crystalline silica, feldspar or kaolin can constitute a preferred choice of inorganic filler, or at least make up the majority of the filler, as they can exhibit a relatively white color. In some embodiments, vitreous and / or amorphous inorganic fillers can preferably be used to constitute the majority of the inorganic filler, as they can reduce the amount of free crystalline silica dust in the manufacture and / or processing of the decorative element.

[0017] The binder is a curable substance configured to cure and thereby bond the particles of the stone or stone-like material together. The binder can be in any form, i.e., liquid, solid, gel or any form suitable for mixing with and being uniformly dispersed in the filler. In some embodiments, the powder form can be preferred, as it reduces the likelihood of contamination of the mixture by other substances that may occur with the use of a wet form of the binder. The binder can be an organic substance, such as a resin. In the most preferred example, the binder can be a thermosetting resin.

[0018] In the most preferred embodiments, the binder comprises a polyester resin, preferably an unsaturated polyester resin, preferably consisting essentially of it. Less preferred alternatives for the binder include acrylic resins, epoxy resins, polyurethanes, rubbers, vinyl ester resins, etc. The binder is preferably less than 20% by weight of the mixture, preferably less than 15%, more preferably less than 10%. The polyester resin shows a very high binding capacity with the inorganic filler. In some embodiments, the resin forming the binder can be selected in such a way as to be able to withstand a temperature of 150 - 250 °C, for example, 150 - 200 °C, for at least a limited time, for example 1 - 20 min, preferably 5 - 20 min. Specifically, it is preferred that the binder be able to withstand this temperature in the cured state. For example, the resin can contain additives suitable for limiting the oxidation of the resin itself. In some embodiments, it is preferred that "being able to withstand the temperature" means that exposure to such a temperature for the said time has a limited or no effect on the color of the decorative element.

[0019] It should be noted that the mixture can also contain additives, such as coupling agents, catalysts or reagents that activate or accelerate the hardening of the binder, and / or temporary binders, such as glue or thermoplastic resins, for temporarily bonding the stone or stone-like material. In the most preferred example, the additive at least includes a silane coupling agent to further enhance the bonding between the silicon-based filler and the binder, preferably an unsaturated polyester binder. In addition, the additive can include crosslinking agents and / or catalysts to activate and / or accelerate the curing of the binder.

[0020] In a preferred embodiment, the mixture may further comprise one or more colorants. The colorant may be in the form of a dye or a pigment. Pigments are generally preferred as they can provide better UV resistance for the final artificial stone. The pigments may be organic or inorganic, with the latter being more preferred as the UV resistance is further enhanced. The preferred colors of the colorant are black, yellow, white, red, and green.

[0021] The mixture may be provided in different forms, for example, in the form of a paste material or a slurry, but preferably in a dry form, such as an incoherent particulate. According to a preferred embodiment where the mixture is provided in the form of an incoherent material, the mixture comprises a first particulate filler and a second particulate binder mixed together, preferably in powder form. Alternatively, the incoherent particulate may be formed by granulates or pellets, where each granulate or pellet comprises a filler and a binder bonded together to form the granulate or pellet.

[0022] In a preferred embodiment, the mixture may be directly provided into a mold, a frame, or any other tool suitable for giving the mixture a shape through a hopper or a feeder.

[0023] Before and / or during the step of providing the mixture into the mold, a first colorant or a first group of colorants may be added to the mixture. The first colorant or the first group of colorants may be evenly distributed in the substrate to provide the base color of the artificial stone. In some embodiments, the first colorant or the first group of colorants may be distributed according to a random motif such as a random texture effect or a dotted effect.

[0024] Before, during, and / or after the step of providing the mixture into the mold, a second colorant or a second group of colorants may be added to the mixture in the mold according to a motif that may be random or predetermined. Preferably, the second colorant or the second group of colorants may be provided according to a predetermined motif, such as the texture of imitation marble, granite, or any natural stone, or the texture effect of flakes. In a preferred embodiment, the predetermined pattern may be formed using a computer-controlled machine equipped with one or more nozzles for dispensing colorants, such as an anthropomorphic robot or a Cartesian robot. The nozzle is connected to a tool that interacts with the surface of the mixture to create grooves or holes for receiving the colorant. Preferably, the predetermined motif is obtained using a computer-controlled machine as described in WO2016 / 113652.

[0025] A random motif formed by a first colorant or a first group of colorants, or a predefined motif formed by a second colorant or a second group of colorants, or preferably a combination thereof, forms a second decorative pattern of the decorative element. The second decorative pattern is present in the substrate and, in particular, throughout the entire thickness of the substrate. In practice, the second decorative pattern forms a three-dimensional decoration.

[0026] The mold can have a shape and dimensions similar to those of the final product to be obtained or a semi-finished product of the process. Preferably, the mold or frame has a shape and dimensions similar to those of a slab or a flat plate. In a preferred embodiment, the mold is made of rubber and includes a concave body adapted to receive the mixture and a lid adapted to close the concave body so that the mixture is completely enclosed within the mold. It should be noted that in a less preferred embodiment, the mixture can be placed directly on a belt or in an open mold or frame.

[0027] Preferably, the compaction step is carried out under vacuum, i.e., a vacuum is created in the mold to assist in extracting the air between the mixture particles. More preferably, vibration is applied to the mold or frame during the compaction step, which helps to compact the mixture particles, resulting in a significant reduction in the porosity of the artificial stone. According to a preferred embodiment, both vacuum and vibration are applied to the mixture during pressing. This can achieve a very high degree of compaction of the mixture, such that after curing, it will result in a very low porosity.

[0028] It should be noted that as a result of the compaction step, the powder and particles of the mixture in the mold can be displaced, thus changing the motif of the first and / or second colorant. Therefore, the final second decorative pattern of the decorative element is different from the motif initially provided into the mold, and each decorative element is unique and different from other decorative elements. Specifically, the vibration can cause the particles to be displaced, which can mix the colors and / or mix the colored and uncolored mixtures. For example, in the case where such displacement occurs at the edge of the texture forming the above-mentioned second decorative pattern, it can cause a shadow to appear on the edge itself, making the contour of the texture less distinct.

[0029] After the compaction step, the mixture in the mold is transferred to a curing station. The curing of the binder can be achieved by radiation, heat, chemical curing, or other suitable techniques. In a preferred embodiment, the curing step is carried out at a temperature below 500 °C, for example, below 200 °C, for example, at room temperature. Specifically, in a preferred embodiment, the curing step can be heat-activated and continue in an exothermic reaction. The activation of the binder curing can occur at a temperature below 100 °C.

[0030] After curing, the artificial stone contains a porosity of less than 1 vol%, more preferably less than 0.5 vol%, and even more preferably less than 0.2 vol%.

[0031] After curing, the artificial stone is removed from the mold. In some embodiments, the artificial stone is cooled and / or conditioned before further steps are performed.

[0032] After curing, the method may include a calibration step and / or a squaring step. Calibration and squaring are machining steps that serve to provide the final desired shape and dimensions to the artificial stone. Specifically, calibration serves to flatten one or both major surfaces of the substrate made of artificial stone.

[0033] The method may also include at least mechanically surface-treating the upper surface of the substrate to impart a desired texture to the substrate. The mechanical surface treatment may be a polishing, grinding or sanding step. In some embodiments, the mechanical surface treatment step may be carried out using an abrasive having a CAMI Grit designation in the range of 300 - 600 grit, preferably 400 grit. The inventors have found that the polishing step carried out in this way can provide an improvement in the adhesion between the substrate and the top layer of the decorative element. In fact, the texture obtained is rough enough to increase the specific surface area, thus overcoming the insufficient adhesion caused by the low porosity of the substrate. In addition, it has been found that the roughness obtained using this type of abrasive in this polishing step optimally enhances the scratch resistance and gloss of the final product.

[0034] In a preferred embodiment, where the ink is a dye-based ink, the mechanical surface treatment step may be carried out using an abrasive having a CAMI Grit designation above 1000 grit, preferably 2000 grit. The inventors have found that dye-based inks, especially polyester-based inks, show a better affinity with the binder, and this high grit of the surface mechanical treatment can provide a substrate surface closer to the final decorative element. For example, according to the preferred embodiment, after the mechanical treatment step, the upper surface of the decorative element shows a gloss measured at a 60° angle according to ASTM C584 higher than 20, more preferably higher than 30, and even more preferably higher than 40 GU (gloss units). It is noteworthy that mechanical surface treatment is superior to chemical surface treatments such as etching, as the latter is less controllable and may damage the artificial stone and / or the second decorative pattern.

[0035] Subsequently, the method of the present invention may include the step of applying a primer coating on the upper surface of the substrate. The primer coating may be adapted to render the surface of the substrate suitable for receiving the ink. In fact, the substrate is substantially non-porous, and the ink tends to bleed out, thereby reducing the resolution. In some embodiments, the primer coating is transparent or translucent, and the second decorative coating is visible through the primer coating itself, and the final aspect of the upper surface of the decorative element is formed by the combination of the first and second aspects. In some embodiments, the bottom coating is only for the purpose of allowing good printing of the ink, and it disappears at least partially, possibly completely, during subsequent operations.

[0036] In the most preferred embodiments, the primer coating may comprise an aqueous primer coating or a solvent-based primer coating. In certain cases, the primer coating may be dried after application. For example, the primer coating may be dried using natural convection air, blowing air, hot air IR radiation, and / or microwave radiation.

[0037] In some embodiments, the primer coating may be applied using a roll coating technique, preferably using a soft roll having a Shore hardness of less than 50 Shore, preferably 20 - 30 Shore, for example, 26 Shore, such as a sponge roll. In some embodiments, the primer coating may be applied in an amount of 5 - 75 g / m 2 , more preferably 5 - 60 g / m 2 , for example, 6 or 10 g / m 2 . In some alternative embodiments, the primer coating may be applied using a spraying technique.

[0038] In a preferred embodiment, a first decorative pattern may be printed on the upper surface of the substrate after applying the primer coating. The printing step may obtain a printed pattern with a resolution of up to 600 dpi, more preferably up to 360 dpi. The printer may be a single-channel or multi-channel printer. The printing step is preferably an inkjet printing step involving ejecting ink droplets from a print head, and the print head may be a piezoelectric (preferred) or bubble (optional) print head.

[0039] In a specific embodiment, the decorative pattern may be printed on a temporary substrate, such as a transfer sheet, for example, by inkjet printing. The temporary substrate may then be applied to the surface of the substrate, and during the following curing step involving applying heat and / or pressure, the subject ink may be transferred from the temporary substrate to the substrate of the decorative element, and the temporary transfer sheet may be removed and subsequently reused or discarded. In this embodiment, the ink forming the decorative pattern may preferably be sublimation ink.

[0040] It should be noted that the printed pattern can preferably be applied to a predetermined point in a fixed relationship, so that the printed pattern is applied to a predetermined position of the substrate, such as a position at a fixed distance (which can be zero) from the edge or corner, and the printed pattern is preferably aligned with the edge of the substrate, preferably aligned with the longitudinal edge of the substrate. Applying the printed pattern to a predetermined point in a fixed relationship is conducive to obtaining at least partial matching between the first and second decorative patterns.

[0041] In a preferred embodiment, the method includes the steps of identifying a second pattern present on the substrate and selecting a pattern to be printed based on the identification. In this way, at least partial matching of the first and second decorative patterns of the decorative element can be obtained to provide a continuity effect from the surface to the thickness.

[0042] According to the present invention, the ink can preferably be a dye-containing ink. Compared with pigment-containing inks, the advantage of dye-containing inks is that they can chemically bond to the printed substrate, ultimately providing higher scratch resistance and wear resistance. In some embodiments, the ink can be a sublimation ink. Preferably, the ink is a water-based ink.

[0043] The ink can exhibit a viscosity below 70 cP, preferably below 50 cP and / or a surface tension below 25 dyn / cm.

[0044] It should be noted that the printed pattern can be obtained by inks of multiple colors, such as inks having four colors, preferably cyan, magenta, yellow and black, or more colors, such as seven or eight colors. In any case, in a preferred embodiment, printing can be carried out with a unique ink. In this case, the selected ink is black ink, especially for marble decoration.

[0045] In some embodiments, the ink can be transparent or semi-transparent, so that the second decorative pattern present in the substrate is visible through the ink, that is, at the same position where the ink drops, the second decoration can be at least partially visible.

[0046] In a preferred embodiment, the ink is a thermosetting ink. For example, under the influence of heat, the ink can dry and / or sublime and / or fix itself to the printed substrate, such as fixing to the adhesive of artificial stone. Preferably, the dyes of the ink include organic substances and / or inorganic-organic complexes. In some instances, the ink can be a sublimation ink.

[0047] The curing and / or fixing of the ink on the upper surface of the substrate can include the step of exposing at least the upper surface of the substrate to heat. For example, the substrate can be exposed to a temperature of 150 - 250 °C, such as 150 - 200 °C. The printed substrate can be exposed to the temperature for at least a limited time, such as 1 - 20 minutes, preferably 5 - 20 minutes.

[0048] In some embodiments, the method may include the step of applying an adhesion promoter coating over the printed pattern. The adhesion promoter coating may improve the adhesion of a subsequent protective coating to the upper surface of the substrate, thereby ultimately improving the scratch resistance of the decorative element. In the most preferred embodiments, the adhesion promoter coating may comprise a silane-based and / or siloxane-based substance. In some embodiments, the adhesion promoter coating may be applied using a roll coating technique, preferably using a soft roll having a Shore hardness of less than 50 Shore, preferably 20 - 30 Shore, e.g., 26 Shore, such as a sponge roll. The adhesion promoter coating may be applied at a wet weight of 5 - 60 g / m 2 , preferably 50 g / m 2 . The adhesion promoter coating may be applied using various techniques, with roll coating being preferred. The adhesion promoter coating is preferably transparent or translucent such that the second decorative coating is visible through it. In the most preferred embodiments, the adhesion promoter coating is a water-based substance, and the method further includes the step of drying the adhesion promoter coating. In some embodiments, the adhesion promoter coating may have a dry matter / water content of 1:6 - 1:3, e.g., 1:4. Preferably, the above application amount of the adhesion promoter is the wet amount, e.g., considering the water content of the coating before the drying step. The drying step may be carried out using hot air blowing and / or IR radiation. The drying step may be carried out at a temperature from room temperature to 100 °C, e.g., at 50 °C.

[0049] The method further includes the step of providing a protective coating over the printed pattern. According to the present invention, the protective coating may be applied according to a variety of possibilities.

[0050] According to the first of the said possibilities, the protective coating may be applied in the form of a curable material, preferably a radiation-curable material.

[0051] In a first preferred embodiment of this first possibility, the protective coating may be provided in a bilayer form. In a first preferred embodiment of the first possibility, the bottom coat may be applied directly on top of the printed pattern, and the top coat may be provided over the bottom coat.

[0052] Preferably, the base coat is transparent or translucent. The base coat is preferably acrylate-based. Possible preferred examples of the base coat can include acrylate-based oligomers such as epoxy acrylate, polyester acrylate, polyurethane acrylate. Other examples of acrylate-based base coats can include acrylate-based monomers, preferably having a functionality of 1-6. Preferably, the base coat includes scratch-resistant additives such as hard particles. Preferably, the base coat contains a UV absorber, such as a UV absorber belonging to the triazine family or the benzotriazole family, which can reduce or prevent yellowing of the base coat caused by UV irradiation (e.g., from sunlight) during normal use of the decorative layer. Preferably, an electron and / or radical scavenger can be included in the base coat. An example of a radical scavenger is a hindered amine light stabilizer (HALS).

[0053] The base coat can preferably be applied using a roll coating technique, preferably using a soft roll having a Shore hardness of less than 50 Shore, preferably 20-30 Shore, such as 26 Shore. In some embodiments, the base coat can be applied in an amount of 5-75 g / m 2 , more preferably 5-60 g / m 2 , for example, 6 or 50 g / m 2 . The inventors unexpectedly found that as the amount of the base coat approaches the lower limit of the indicated range, the final surface finish, especially gloss, can be improved. On the other hand, it was found that the higher the amount of the base coat, the better the synergistic effect with the top coat, as it is easier to perform the sanding step, which will be described below.

[0054] The method preferably includes a step of partially or possibly fully curing the base coat before the step of providing the top coat. Preferably, the base coat can be cured using a gallium UV lamp and / or a mercury (HG) UV lamp. In a preferred embodiment, the base coat is fully cured using, for example, a gallium and mercury (HG) UV lamp.

[0055] After applying the base coat and at least partially, preferably fully curing it, the method may preferably include a mechanical surface treatment of the base coat. The mechanical surface treatment may be a polishing, grinding or sanding step. In a preferred embodiment, the method includes a sanding step. This intermediate step between applying the base coat and the top coat can remove any patterns left by roll coating, such as orange peel effect, and obtain a smooth polished surface, while improving the adhesion of the top coat, thereby improving the scratch resistance of the top layer. In the most preferred embodiment, the sanding step is carried out using abrasives having a CAMI grit number of 300 - 1000. In the most preferred embodiment, the sanding step can be carried out using a plurality of abrasives having an increasing CAMI grit number. For example, the first abrasive may exhibit a grit size of 300 - 400, such as a CAMI grit number of 320. Preferably, the first abrasive may move in a direction orthogonal or at least oblique to the advancing direction of the decorative element. For example, the second abrasive may exhibit a grit size of 400 - 600, such as a CAMI grit number of 500. Preferably, the second abrasive may move in a direction substantially parallel to the advancing direction of the decorative element. For example, the third abrasive may exhibit a grit size of 500 - 700, such as a CAMI grit number of 600. Preferably, the third abrasive may move in a direction orthogonal or at least oblique to the advancing direction of the decorative element. For example, the fourth abrasive may exhibit a grit size of 600 - 1000, such as a CAMI grit number of 800. Preferably, the fourth abrasive may move in a direction substantially parallel to the advancing direction of the decorative element. The base coat texture obtained using these types of abrasives in this sanding step has been found to ideally optimize the scratch resistance and gloss of the final product.

[0056] The top coat may be transparent or translucent. The top coat may preferably be acrylate-based. Possible preferred examples of the top coat may include acrylate-based oligomers, such as epoxy acrylate, polyester acrylate, polyurethane acrylate. Other examples of acrylate-based top coats may include acrylate-based monomers, preferably having a functionality of 1 - 6. Preferably, the top coat includes a UV absorber, such as belonging to the triazine family or the benzotriazole family. Preferably, an electron and / or radical scavenger may be included in the UV top coat. An example of a radical scavenger is a hindered amine light stabilizer (HALS). Preferably, the top coat also includes a radical scavenger, which can reduce the risk of yellowing of the top coat when exposed to sunlight. The method preferably includes a step of curing, preferably fully curing the top coat. During the curing of the top coat, one or more layers that are still gelled or partially cured below can be fully cured. The top coat is preferably cured using a gallium and / or mercury UV lamp, preferably using both.

[0057] In some embodiments, when a matte surface is desired, excimer radiation is preferably used to cure the top coat.

[0058] According to the specific embodiment, at least the top coat is cured using an electron beam. The electron beam may be preferred because it does not require a photoinitiator to be present in the composition of the top coat. Thus, since no photoinitiator is released, the top layer can be easily certified as suitable for contact with food.

[0059] According to an alternative preferred embodiment, the top coat comprises a polymeric photoinitiator. The polymeric photoinitiator has the property that it can crosslink with the polymer matrix of the top coat to prevent its release. Thus, the top layer can be easily certified as suitable for contact with food.

[0060] Preferably, the top coat shows a degree of polymerization of at least 90%, more preferably 94% or higher after curing.

[0061] The top coat can be applied using roll coating, reverse roll coating, curtain coating or spray coating. In a preferred embodiment, the top coat can be applied using roll coating or reverse roll coating, with the latter being found to provide the best results in terms of gloss. The roll used for applying the top coat can be a hard roll, such as a hard roll showing a Shore hardness higher than 40 Shore, preferably 50 Shore. Applying the topmost layer using a hard roll provides a smoother surface finish and can have a higher gloss.

[0062] In some embodiments, the top coat can be applied in an amount of 2 - 10 g / m 2 , for example, 6 g / m 2 .

[0063] Preferably, the top coat has a gloss of 20 - 50 GU, more preferably 25 - 40 GU, measured at a 60° angle.

[0064] According to a second preferred embodiment of the first possibility of forming the protective coating, the protective coating is formed in a unique layer. In fact, since the printed pattern is formed by dyes bonded to the substrate, the scratch resistance and abrasion resistance are already acceptable. Thus, the main purpose of this protective coating is to improve the lightfastness of the dyes. By confining the protective coating to one layer, the impact of the protective coating on the final appearance of the decorative element can be limited, making the decorative element look less plastic and more natural.

[0065] According to this second preferred embodiment, the protective layer can be made according to the undercoat or preferably according to the top coat of the first preferred embodiment of the first possibility described above.

[0066] According to a second possibility of forming a protective coating, the protective coating can be made of a silicon-based material, preferably a silicon-based polymer or oligomer, such as polysiloxane (silicone), siloxane, etc. The protective coating of the above second possibility can preferably contain a UV absorber, for example, a UV absorber belonging to the triazine family or the benzotriazole family. Preferably, an electron and / or radical scavenger can be included in the protective coating. An example of a radical scavenger is a hindered amine light stabilizer (HALS). Preferably, the protective coating can be applied in the form of an aqueous material. According to the second possibility, the protective coating can be dried and / or cured using heat.

[0067] In a specific variant of this second possibility, the protective coating can be in the form of a penetrating sealer rather than a coating on the surface. A sealer is a substance that fills and seals the open pores and irregularities on the surface of a material. Specifically, a reactive sealer can be a substance that can form a chemical bond with the mixture of artificial stone, preferably a substance that can form a chemical bond with mineral fillers. In a preferred example, the sealer can be a sealer of silane, siloxane chemistry, or a sealer of silicate, methyl siliconate, fluorosilicate chemistry. In this example, the sealer is water-based and first cures as the water evaporates, and then reacts with the mineral filler and covalently bonds.

[0068] In some embodiments, the method can include one or more steps for forming a relief on the surface of the decorative element and / or one or more steps for forming regions with different gloss levels. The relief and / or different gloss levels can be obtained according to a pattern, more preferably determined by a printed pattern. Preferably, the printed pattern can be obtained by a non-contact printing technique, such as digital inkjet printing. For example, the printed pattern is intended to provide a substance on the surface of the decorative element that will change the chemical or physical characteristics of the surface of the decorative element. Preferably, the above substance can be printed on one or more of a primer coating, a base coat, or a top coat before the corresponding gelling and / or curing. The substance can be, for example, a lacquer repellent, which can locally replace the coating material printed thereon, so that a depression is formed at the pattern. Subsequently, the substance is removed by, for example, drying. The substance can be a substance that can locally prevent the coating material printed therein and / or thereon from curing or at least change its curing conditions, so that after curing, the coating at the pattern will be harder or softer than the coating in the area where the substance is not printed. Subsequently, the coating is treated, for example, mechanically removing the uncured or softer areas of the coating (possibly together with the substance) to form a depression. Examples of such substances can be antioxidants, electron scavengers, curing inhibitors. Alternatively, the substance can cause a local change in the gloss level of the coating, for example, it can locally change the crystallization conditions of the coating printed therein and / or thereon. Description of the Drawings

[0069] For a better illustration of the features of the present invention, several preferred embodiments are described hereinafter by way of example without any limiting features, with reference to the accompanying drawings, in which:

[0070] Figure 1 is a perspective view of a decorative element according to the present invention;

[0071] Figure 2 shows, on a larger scale, a cross-section along Figure 1 line II-II in

[0072] Figure 3 shows, on a larger scale, a view of area F3 in Figure 2 ;

[0073] Figure 4 shows Figure 1 some steps of a method for manufacturing the decorative element. DETAILED DESCRIPTION

[0074] With reference to Figure 1 and Figure 2 , the decorative element 1 is shown in the form of a slab having a length X of at least 2 m, preferably at least 2.5 m, for example 3 m or more, and a width Y of at least 1 m, preferably 1.5 m or more. In addition, the decorative element 1 shows a thickness Z of at least 10 mm, preferably at least 20 mm, for example 30 mm.

[0075] The decorative element 1 comprises a substrate 2 and a top layer 3 covering the upper surface of the substrate 2.

[0076] The substrate 2 is made of artificial stone, which includes inorganic fillers and a cured organic binder that binds the particles of the inorganic fillers together. The inorganic fillers are based on silicon oxides such as silica or feldspar. The binder is preferably a thermosetting resin, more specifically an unsaturated polyester resin.

[0077] The decorative element 1 includes a first decorative pattern 4 and a second decorative pattern 5. The first and second decorative patterns 4, 5 are visible from the top surface of the decorative element itself. The upper surface of the decorative element has a glossiness of 20 - 50, more preferably 25 - 40, measured at a 60° angle.

[0078] The first decorative pattern 4 is a printed pattern present on the upper surface of the substrate 2, while the second decorative pattern is a three-dimensional decoration present throughout the thickness of the substrate 2. The first decorative pattern 4 has a higher resolution than the second decorative pattern 5.

[0079] As Figure 3 shown in

[0080] The first decorative pattern 4 is formed by inkjet printing ink. The ink forming the decorative layer contains an organic dye that binds to the binder of the substrate 2.

[0081] The protective coating 9 is acrylate-based and contains a UV-curing substance. The adhesion-promoting coating 6 and the protective coating 9 are transparent and contain a UV absorber.

[0082] Figure 4 Shows some steps of a method for manufacturing Figure 1 the decorative element according to the present invention.

[0083] In step S1, the mixture 10 is provided to the mold 15 for manufacturing the substrate 2. The mixture 10 contains an inorganic filler and a binder.

[0084] The filler consists of a combination of powder and fine grains, such as silica, feldspar, and / or other silicon-containing minerals. For example, the combination contains at least 60 wt% of fine grains and / or particles and 20 wt%-35 wt% in powder form. Wherein, for example, the particles have a particle size distribution of 0.1-6.5 mm, while the powder has an average particle size of less than 45 μm, preferably less than 20 μm. This filler preferably accounts for at least 80 wt% of the mixture, preferably more than 85 wt%, more preferably more than 90 wt%.

[0085] The binder, such as unsaturated polyester, is in powder form and accounts for 10 wt% of the mixture.

[0086] The mixture 10 further contains additives, such as coupling agents, catalysts, or crosslinking agents.

[0087] In step S1, the mixture 10 is deposited from the hopper 11 onto the first belt 12. The feeder 13 feeds the first set of colorants 14 into the mixture 10 on the first belt 12. Due to the advancement of the first belt 12, the mixture 10 with the first colorant 14 falls into the mold 15 placed below the first belt 12 on the second belt 16. Due to this fall, the first colorant 14 is randomly distributed in the mixture 10 in the mold 15.

[0088] Once the mixture 10 enters the mold 15, the robotic arm 17 delivers the second set of colorants 18 into the mixture 10 according to a predetermined theme. The pattern obtained by the combination of the first set of colorants 14 and the second set of colorants 18 substantially constitutes the second decorative pattern 5.

[0089] The mixture 10 in the mold 15 is advanced in the forward direction A to the compaction station 19 for the compaction step S2. The compaction station 19 includes a vibration unit 20 and a vacuum unit 21 for applying vibration and vacuum to the mixture in the mold 15, thereby causing its compaction.

[0090] Then, the still-forming mixture 10 is transported to a curing station 22 where the binder cures in a curing step S3. The curing of the binder is activated at a temperature below 200 °C and then continues with the exothermic reaction.

[0091] After the curing step S3, the obtained artificial stone substrate 2 is removed from the mold 15, which is now a coherent material with a porosity of less than 0.2%, and is transported to a plurality of machining stations for finishing operations on the substrate 2.

[0092] In step S4, the substrate 2 is calibrated to level at least its upper surface. Subsequently, in step S5, the substrate 2 is corrected to its final desired dimensions. It should be noted that steps S4 and S5 can be reversed.

[0093] Subsequently, in a polishing step S6, at least the upper surface of the substrate is mechanically treated. The polishing step S6 is carried out using an abrasive having a CAMI grit number of 300 - 600 grit, preferably 400 grit.

[0094] Then the substrate 2 is moved to a first coating station 23 to apply a primer coating 7 in a first coating step S7. It includes a sprayer 24 and a hot air blower 25 for drying the primer. The primer is preferably applied in the form of an aqueous solution or suspension. Drying is carried out at 50 °C.

[0095] Then, in a printing step S8, the substrate 2 is moved to a printing station 29 for printing a first decorative pattern 4. The printing station includes a single-pass inkjet printer 30 and an oven 31. The printer 30 is configured to print at least four inks: cyan, magenta, yellow, and black, and may add one or more spot colors. The ink is a water-based sublimation-curing dye-based ink. The dye is an organic dye.

[0096] After printing, the substrate is moved into the oven 31, which is a static oven in this embodiment. In the oven 31, the printed substrate 2 is exposed to a temperature of 150 - 200 °C to cure the ink, while the carrier of the ink (e.g., water) evaporates and the dye forms a bond with the substrate 2, specifically with its binder. The printed substrate 2 is exposed to the said temperature in the oven 31 for a curing time of 5 to 20 minutes. During curing, the primer layer 7 degrades and substantially disappears from the surface of the substrate 2.

[0097] The printed substrate 2 is then moved to the second coating station 32, where a tackifier coating 6 is applied in a second coating step S9. The second coating station 32 includes one or more coating rollers 27 and one or more hot air blowers 28 for drying the tackifier coating. The tackifier coating is applied in the form of an aqueous solution or dispersion and contains a silane and / or siloxane-based composition. The tackifier coating is dried at 50 °C.

[0098] The substrate 2 is then moved to the third coating station 39, where a protective coating 9 is applied in a third coating step S10. The third coating station 39 includes one or more coating rollers 40, one or more gallium UV lamps 28 for curing the protective coating, and one or more mercury HG UV lamps 33. The protective coating is applied in an amount of 6 g / m using a hard roller 40 having a hardness of 50 Shore. 2 After application, the protective coating is fully cured using the gallium UV lamp 28 and the mercury HG UV lamp 33.

[0099] The present invention is in no way limited to the above-described embodiments, but rather, this decorative element and its manufacturing method can be realized according to different variations without departing from the scope of the present invention.

[0100] Furthermore, it is obvious from the content of the specification that the present invention relates to one or more of the following listed clauses:

[0101] 1. A method for manufacturing a decorative element, the decorative element comprising a substrate and a top layer, wherein the substrate is made of artificial stone and wherein the top layer contains a decorative pattern, comprising the steps of:

[0102] - providing a mixture comprising at least an inorganic filler and a binder;

[0103] - compacting the mixture;

[0104] - curing the binder to obtain the substrate;

[0105] and wherein the method includes the step of inkjet printing a first decorative pattern on at least the top surface of the substrate.

[0106] 2. The method according to clause 1, wherein the decorative element is in the form of a flat panel or slab.

[0107] 3. The method according to clause 2, wherein the slab has a length of at least 2 m, preferably at least 2.5 m, for example 3 m or longer, and a width of at least 1 m, preferably 1.5 m or wider.

[0108] 4. The method according to clause 2 or clause 3, wherein the slab has a thickness of at least 10 mm, preferably at least 20 mm, for example 30 mm.

[0109] 5. A method according to any of the preceding clauses, wherein the inorganic filler comprises mineral materials such as any type of stone, sand, siliceous mineral materials such as quartz, silica sand, clay, feldspar, cristobalite, granite, talc or calcareous mineral materials such as calcium carbonate, marble, gypsum.

[0110] 6. A method according to any of the preceding clauses, wherein the inorganic filler may comprise ceramics, glass, metals and other inorganic materials such as recycled materials.

[0111] 7. A method according to any of the preceding clauses, wherein most of the filler, i.e. at least 50 wt%, consists of silicon (Si)-based inorganic materials, and more preferably consists mainly of them.

[0112] 8. A method according to any of the preceding clauses, wherein the filler may be in the form of powder, granules, fragments, fines, aggregates or any other particulate form, but is preferably in the form of granules and powder.

[0113] 9. A method according to any of the preceding clauses, wherein the filler is at least partially in the form of a powder having an average particle size of less than 45 μm, preferably less than 20 μm.

[0114] 10. A method according to any of the preceding clauses, wherein the filler is at least partially in the form of aggregates, fines and / or granules having a particle size distribution of 0.1 - 6.5 mm, preferably 0.1 - 2 mm, 0.1 - 0.7 mm.

[0115] 11. A method according to any of the preceding clauses, wherein the filler consists of a combination of powder and fines, for example the combination may comprise at least 60 wt% of fines and / or granules and 20 wt% - 35 wt% in the form of powder, wherein, for example, the granules have a particle size distribution of 0.1 - 6.5 mm and the powder has an average particle size of less than 45 μm, preferably less than 20 μm.

[0116] 12. A method according to any of the preceding clauses, wherein the filler preferably accounts for at least 80 wt% of the mixture, preferably more than 85 wt%, more preferably more than 90 wt%.

[0117] 13. A method according to any of the preceding clauses, wherein the binder is a curable substance configured to bond the particles of the filler together upon curing.

[0118] 14. A method according to any of the preceding clauses, wherein the binder comprises a polyester resin, preferably an unsaturated polyester resin, preferably consisting essentially of it.

[0119] 15. A method according to any of the preceding clauses, wherein the binder preferably accounts for less than 20 wt% of the mixture, preferably less than 15%, more preferably less than 10%.

[0120] 16. A method according to any of the preceding clauses, wherein the mixture comprises additives such as coupling agents, catalysts or reagents that activate or accelerate the hardening of the binder, and / or a temporary binder that temporarily bonds the stone or stone-like material, such as glue or a thermoplastic resin.

[0121] 17. A method according to any of the preceding clauses, wherein the mixture comprises at least a silane coupling agent.

[0122] 18. A method according to any of the preceding clauses, wherein the mixture comprises one or more colorants.

[0123] 19. A method according to clause 18, wherein the colorant can be in the form of a dye or a pigment.

[0124] 20. A method according to clause 19, wherein the pigment can be an organic or inorganic pigment.

[0125] 21. A method according to any of the preceding clauses, wherein the mixture is provided in a mold.

[0126] 22. A method according to clause 21, wherein a first colorant or a first group of colorants is added to the mixture before and / or during the step of providing the mixture in the mold.

[0127] 23. A method according to clause 22, wherein the first colorant or the first group of colorants is uniformly distributed in the substrate, providing the base color of the artificial stone, and / or wherein the second colorant or the first group of colorants is distributed according to a random theme, such as a random texture effect or a dot effect.

[0128] 24. A method according to any of clauses 21 to 23, wherein a second colorant or a second group of colorants can be added in a manner that forms a second decorative pattern of a decorative element during and / or after the step of providing the mixture in the mold.

[0129] 25. A method according to clause 24, wherein the second colorant or the second group of colorants is provided according to a predetermined theme, such as an effect that mimics the texture of marble, granite or any natural stone or the texture of flakes.

[0130] 26. A method according to clause 25, wherein the random theme of the first colorant or the first group of colorants, or the predetermined pattern of the second colorant or the second group of colorants, or preferably a combination thereof, constitutes the second decorative pattern of the decorative element.

[0131] 27. A method according to clause 26, wherein the second decorative pattern is present in the substrate and specifically throughout the entire thickness of the substrate.

[0132] 28. A method according to any of the preceding clauses, wherein the method comprises a step of compacting the mixture.

[0133] 29. A method according to clause 28, wherein the compaction step is carried out by applying vacuum and vibration.

[0134] 30. A method according to any of the preceding clauses, wherein the curing of the binder can be achieved by radiation, heating, chemical curing or other suitable techniques.

[0135] 31. A method according to any of the preceding clauses, wherein the curing of the binder is carried out at a temperature below 500 °C, for example below 200 °C, for example at room temperature.

[0136] 32. A method according to any of the preceding clauses, wherein the curing step is heat-activated and continues under exothermic reaction.

[0137] 33. A method according to clause 32, wherein the activation of the binder curing can occur at a temperature below 100 °C.

[0138] 34. A method according to any of the preceding clauses, wherein after curing, the artificial stone has a porosity of less than 1 vol%, preferably less than 0.5 vol%, more preferably less than 0.2 vol%.

[0139] 35. A method according to any of the preceding clauses, wherein after curing, the method includes a calibration step and / or a sizing step.

[0140] 36. A method according to any of the preceding clauses, wherein the method includes a polishing step, and the polishing step is adapted to provide a desired texture to the upper surface of the substrate.

[0141] 37. A method according to clause 36, wherein the polishing step is carried out using an abrasive having a CAMI grit number of 300 - 600 grit, preferably 400 grit, or using an abrasive having a CAMI grit number greater than 1000 grit.

[0142] 38. A method according to any of the preceding clauses, wherein the method includes applying a primer coating on the upper surface of the substrate.

[0143] 39. A method according to clause 44, wherein the primer coating is transparent or translucent.

[0144] 40. A method according to clause 44 or 45, wherein the primer coating is a radiation-curable substance, preferably a UV-curable substance.

[0145] 41. A method according to clause 44 or 45, wherein the primer coating is applied in an aqueous-based form.

[0146] 42. A method according to any of clauses 44 to 47, wherein the method includes a step of drying the primer coating using, for example, hot air.

[0147] 43. A method according to any of the preceding clauses, wherein the printing step is carried out to obtain a printed pattern with a resolution of up to 360 dpi.

[0148] 44. A method according to any of the preceding clauses, wherein the printed pattern is preferably applied to a predetermined point in a fixed relationship.

[0149] 45. A method according to any of the preceding clauses, wherein the method includes the steps of identifying a second pattern present on the substrate and selecting the pattern to be printed based on the identification.

[0150] 46. A method according to any of the preceding clauses, wherein the ink is a dye-containing ink.

[0151] 47. A method according to clause 53, wherein the dye can be an organic dye.

[0152] 48. A method according to any of the preceding clauses, wherein the ink is a heat-curable ink, such as a sublimation ink.

[0153] 49. A method according to clause 56, wherein the method preferably includes the step of curing the printed ink by exposing the printed substrate to heat.

[0154] 50. A method according to clause 56, wherein the step of curing the heat-curable ink can be carried out at a temperature of 150 - 250 °C, for example, 150 - 200 °C.

[0155] 51. A method according to clause 55 or 56, wherein the primer coating (if present) substantially disappears during the heat-curing step.

[0156] 52. A method according to any of the preceding clauses, wherein the ink is transparent or translucent, such that a second decorative pattern present in the substrate is visible through the ink.

[0157] 53. A method according to any of the preceding clauses, wherein the method includes the step of applying a tackifier coating over the printed pattern.

[0158] 54. A method according to clause 53, wherein the tackifier coating includes a silane and / or a siloxane-based substance.

[0159] 55. A method according to clause 53 or 54, wherein the tackifier coating is applied in a wet amount of 20 - 60 g / m 2 , preferably 40 g / m 2 .

[0160] 56. A method according to any one of clauses 53 or 55, wherein the tackifier coating is a water-based substance, and the method further includes the step of drying the tackifier coating.

[0161] 57. A method according to clause 56, wherein the tackifier coating contains a dry matter / water content of 1:6 - 1:2, for example 1:4, before drying.

[0162] 58. A method according to clause 56 or 57, wherein the drying step can be carried out using air blowing and / or IR radiation.

[0163] 59. A method according to any of the preceding clauses, wherein the method includes the step of providing a protective coating above the printed pattern.

[0164] 60. A method according to clause 59, wherein the protective coating is transparent or translucent.

[0165] 61. A method according to clause 59 or 60, wherein the protective coating is preferably acrylate-based, such as acrylate-based oligomers, such as epoxy acrylate, polyester acrylate, polyurethane acrylate, or acrylate-based monomers, preferably having a functionality of 1 - 6.

[0166] 62. A method according to any of clauses 59 to 61, wherein the protective coating contains scratch-resistant additives, such as hard particles.

[0167] 63. A method according to any of clauses 59 to 62, wherein the protective coating contains a UV absorber, such as a UV absorber belonging to the triazine family or the benzotriazole family.

[0168] 64. A method according to any of clauses 59 to 63, wherein the protective coating is applied in an amount of 5 - 75 g / m 2 , preferably 5 - 60 g / m 2 , for example, 6 or 60 g / m 2 .

[0169] 65. A method according to any of clauses 59 to 64, wherein the method includes the step of at least partially, possibly completely curing the protective coating.

[0170] 66. A method according to any of clauses 59 to 65, wherein the protective coating is cured using a gallium and / or mercury UV lamp, preferably both.

[0171] 67. A method according to any of clauses 59 to 65, wherein the protection is cured using excimer radiation.

[0172] 68. A method according to any of clauses 59 to 67, wherein the protective coating is cured using an electron beam.

[0173] 69. A method according to any of clauses 59 to 68, wherein the protective coating contains a polymer photoinitiator.

[0174] 70. A method according to any one of clauses 59 to 69, wherein the protective coating exhibits a degree of polymerization of at least 90%, more preferably 94% or higher, after curing.

[0175] 71. A method according to any one of clauses 59 to 70, wherein the protective coating is in the form of a single layer.

[0176] 72. A method according to any one of clauses 59 to 70, wherein the protective coating comprises a primer layer applied over the printed pattern and a topcoat disposed over the primer layer.

[0177] 73. A method according to clause 72, wherein the primer layer is transparent or translucent.

[0178] 74. A method according to clause 72 or 73, wherein the primer layer is preferably acrylate-based, such as an acrylate-based oligomer, such as epoxy acrylate, polyester acrylate, polyurethane acrylate, or an acrylate-based monomer, preferably having a functionality of 1-6.

[0179] 75. A method according to any one of clauses 72 to 74, wherein the primer layer contains a scratch-resistant additive, such as hard particles.

[0180] 76. A method according to any one of clauses 72 to 75, wherein the primer layer contains a UV absorber, such as a UV absorber belonging to the triazine family or the benzotriazole family.

[0181] 77. A method according to any one of clauses 72 to 76, wherein the primer layer is applied in an amount of 5-75 g / m 2 , preferably 5-60 g / m 2 For example, 6 or 60 g / m 2 .

[0182] 78. A method according to any one of clauses 72 to 77, wherein the method includes a step of at least partially, possibly completely, curing the primer layer before the step of providing the topcoat.

[0183] 79. A method according to any one of clauses 72 to 78, wherein the primer layer is cured using a gallium UV lamp.

[0184] 80. A method according to clause 72 or 79, wherein after applying the primer layer and at least partially curing, preferably completely curing, the method includes a step of sanding the primer layer.

[0185] 81. A method according to any one of clauses 72 to 80, wherein the topcoat is transparent or translucent.

[0186] 82. A method according to any one of clauses 72 to 81, wherein the topcoat is preferably acrylate-based, such as an acrylate-based oligomer, such as epoxy acrylate, polyester acrylate, polyurethane acrylate, or an acrylate-based monomer, preferably having a functionality of 1-6.

[0187] 83. A method according to any one of clauses 72 to 82, wherein the topcoat contains a UV absorber, such as a UV absorber belonging to the triazine family or the benzotriazole family.

[0188] 84. A method according to any one of clauses 72 to 83, wherein the topcoat contains a radical scavenger.

[0189] 85. A method according to any one of clauses 72 to 84, wherein the topcoat is applied in an amount of 2-10 g / m 2 , for example 6 g / m 2 .

[0190] 86. A method according to any one of clauses 72 to 85, wherein the method includes the step of at least partially, preferably completely curing the topcoat.

[0191] 87. A method according to clause 86, wherein during the curing of the topcoat, the bottomcoat is finally cured.

[0192] 88. A method according to clause 86 or 87, wherein the topcoat is cured using a gallium and / or mercury UV lamp, preferably cured using both.

[0193] 89. A method according to any one of clauses 86 to 87, wherein the topcoat is cured using excimer radiation.

[0194] 90. A method according to any one of clauses 86 to 87, wherein the topcoat is cured using an electron beam.

[0195] 91. A method according to any one of clauses 86 to 89, wherein the topcoat contains a polymer photoinitiator.

[0196] 92. A method according to any one of clauses 86 to 91, wherein the topcoat shows a degree of polymerization of at least 90%, more preferably 94% or higher after curing.

[0197] 93. A method according to any one of clauses 72 to 92, wherein the bottomcoat and the topcoat can be applied using roll coating, reverse roll coating, curtain coating, or spraying.

[0198] 94. A method according to clause 93, wherein the bottomcoat is applied using a roll, and the topcoat is applied using a reverse roll.

[0199] A method according to any of the preceding clauses, including one or more steps of forming a relief on the surface of a decorative element, and / or one or more steps of forming regions having different degrees of gloss.

[0200] 96. A method according to clause 95, wherein the relief and / or the regions of different degrees of gloss can be obtained according to a pattern, more preferably determined by a printed font.

Claims

1. A method for manufacturing a decorative element (1), said decorative element comprising a substrate (2) and a top layer (3), wherein said substrate is made of artificial stone and said top layer comprises decorative patterns (4, 5), the method comprising the following steps: - providing (S1) a mixture (10) comprising at least an inorganic filler and a binder; - compacting (S2) the mixture (10); - curing (S3) the binder to obtain the substrate (2); and wherein the method comprises the step of inkjet printing (S8) a first decorative pattern (4) on at least the top surface of the substrate, wherein the ink is a heat-curable ink, such as a sublimation ink, wherein the method preferably comprises the step of curing the printed ink by exposing the printed substrate to heat, wherein the method comprises the step of providing a protective coating (9) above the first decorative pattern (4).

2. The method according to claim 1, wherein The protective coating (9) comprises a UV absorber, such as a UV absorber belonging to the triazine family or the benzotriazole family.

3. The method according to claim 1 or 2, wherein The protective coating (9) contains electron and / or radical scavengers.

4. The method according to any one of the preceding claims, wherein, The protective coating (9) is made of a silicon-based material, preferably a silicon-based polymer or oligomer such as polysiloxane (silicone) or siloxane.

5. The method according to any one of claims 1 to 4, wherein The protective coating (9) is acrylate-based, such as an acrylate-based oligomer, such as epoxy acrylate, polyester acrylate, polyurethane acrylate, or an acrylate-based monomer, preferably having a functionality of 1-6.

6. The method according to any one of the preceding claims, wherein, The protective coating (9) is in the form of a single layer.

7. The method according to any one of claims 1 to 6, wherein The protective coating (9) comprises a primer layer applied above the printed pattern and a top layer provided above the primer layer.

8. The method according to any one of claims 1 to 4, wherein The protective coating (9) is in the form of a penetrating sealant layer.

9. The method according to any one of the preceding claims, comprising the step of applying (S9) a tackifier coating (6) above the printed pattern.

10. The method according to claim 9, wherein, The tackifier coating (6) comprises a silane and / or siloxane-based substance.

11. The method according to any one of the preceding claims, comprising the step of applying (S7) a primer coating (7) on the upper surface of the substrate before the step of printing (S8).

12. The method according to claim 11, wherein, The primer coating (7) is transparent or translucent.

13. The method according to claim 11 or 12, wherein, The primer coating (7) is a radiation-curable substance, preferably a UV-curable substance.

14. The method according to any one of claims 11 to 13, wherein the primer coating (7) is applied in an aqueous-based form.

15. The method according to claim 14, wherein, The method comprises the step of drying the primer coating (7) using, for example, hot air.

16. The method according to claim 14 or 15, wherein The primer coating (7) substantially disappears during the heat-curing step.

17. The method according to any one of the preceding claims, wherein, The mixture (10) comprises one or more colorants.

18. The method according to claim 17, wherein, The colorant may be in the form of a dye or a pigment.

19. The method according to any one of the preceding claims, wherein, The mixture (10) is provided in a mold (15).

20. The method according to claim 19, wherein Before and / or during the step of providing the mixture (10) into the mold (16), a first colorant (14) or a first group of colorants is added to the mixture, and wherein the first colorant or the first group of colorants is uniformly distributed in the substrate to provide the base color of the artificial stone, and / or wherein the first colorant or the first group of colorants is distributed according to a random theme such as a random texture effect or a dotted effect.

21. The method according to claim 20, wherein, During and / or after the step of providing the mixture (10) into the mold (15), a second colorant (18) or a second group of colorants can be added to the mixture in the mold (15), and wherein the second colorant or the second group of colorants is provided according to a predetermined theme, for example, mimicking the texture of marble, granite or any natural stone or the texture effect of flakes.

22. The method according to claim 20 or 21, wherein, The random theme of the first colorant (14) or the first group of colorants, or the predetermined theme of the second colorant (18) or the second group of colorants, or preferably a combination thereof, forms the second decorative pattern (15) of the decorative element (1).

23. The method according to claim 22, wherein, The second decorative pattern (5) is present in the substrate (2), and in particular, throughout the thickness of the substrate.

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