Manufacturing method of decorative foil

Abstract

The present invention relates to a manufacturing process for high performance resin saturated decorative foils designed for outdoor and indoor surface linings, which can be used as decorative linings for HPL (High Pressure Laminate) and CPL (Continuous-Pressure Laminate) panels and for adhesion to any flat or curved 2D surface.

Description

[Technical field]

[0001] <Technical field> The present invention relates to a manufacturing process for high performance resin saturated decorative foils designed for outdoor and indoor surface linings, which can be used as decorative linings for HPL (high pressure laminate) and CPL (continuous-pressure laminate) panels and for adhesion to any flat or curved 2D surface.

[0002] High Pressure Laminate (HPL) panels and Continuous Pressure Laminate (CPL) panels are examples of panels made from different materials used in applications requiring resistance to scratches, abrasion, chemical attack or any kind of vandalism, and which also have the particularity of maintaining color fastness. To achieve these specific characteristics, decorative panels impregnated with modified melamine resins and surfaces made of coatings capable of meeting the properties required in each case are described in the state of the art.

[0003] Melamine-impregnated paper has limited resistance to acid attack and is not particularly suitable for use in outdoor applications. This problem is partially solved in US Patent No. 4,927,572, which discloses a method for producing a decorative panel, comprising the steps of: preparing an underlay; applying a decorative layer to the underlay; applying a liquid coating consisting essentially of a radiation-polymerizable mixture to the decorative layer; applying radiation to form a radiation-polymerized layer on the decorative layer; and hot pressing the underlay, the decorative layer and the radiation-polymerized layer together under conditions of elevated temperature and pressure such that a scratch resistance of 1.5 Newtons or greater is achieved.

[0004] Furthermore, European Patent No. EP 1631454 B1 discloses a decorative panel including a decorative layer on one or both sides of a support layer, the decorative layer including a base layer and a surface layer, the base layer being printed paper, the surface layer being a synthetic resin including one or more radiation curable components, an adhesive layer being present between the support layer and the decorative layer, the adhesive layer being in contact with the base layer, characterized in that a transparent layer being present between the base layer and the surface layer, the transparent layer being made of a synthetic resin including a radiation curable component selected from the group of unsaturated (meth)acrylates.

[0005] European Patent No. EP 2406086 B1 discloses a method for producing decorative paper and decorative panels using a water-based resin that is impregnated into a substrate.

[0006] More specifically, EP 2406086 B1 discloses a method comprising the steps of: preparing a paper; impregnating the paper with a first active radiation curable resin; drying the paper obtained in the previous step; applying a second active radiation curable resin to the dried paper obtained in the previous step; and curing the paper obtained in the previous step to obtain a resin-impregnated decorated paper; characterized by an initial drying process with a residual moisture of <5%, calculated based on the weight obtained after said drying step.

[0007] European Patent No. EP 2574476 B1 is also relevant and discloses a method for the manufacture of a decorative film comprising a resin-impregnated base paper and one or more top layers. The method comprises the following steps: preparing a resin-impregnated base paper; printing the base paper with an ink composition using inkjet technology; subjecting the previously printed base paper to a drying and / or curing treatment; applying one or more transparent top layers to the paper obtained in the previous step; curing the paper from the previous step. A further feature of the method is that the degree of impregnation of the resin-impregnated base paper used in the first step is between 30% and 60%, based on the dry weight of the base paper used as a base. The resin present in the base paper contains reactive groups and the resin is present throughout the entire thickness of the base paper. Summary of the Invention [Problem to be solved by the invention]

[0008] Although the processes disclosed in the above state of the art generally improve the characteristics of melamine resin impregnated panels, some limitations are still observed in the following respects: poor adhesion between layers, poor internal cohesion of the paper, poor impermeability of the decorative paper, difficulty in achieving a flat product, premature life of the decorative foil even before use, difficulty in stable processing of the product, poor resistance to atmospheric conditions, high risk of permeable porosity or unsaturated paper areas, reliance on an external adhesive layer to ensure saturation of the paper, and inability to reduce or eliminate the content or reliance on resins containing formaldehyde as adhesives, etc. One of the aims of the present invention is to solve these problems by a manufacturing method and the resulting panels as described in the appended claims. [Means for solving the problem]

[0009] <Description of the Invention> One of the objects of the present invention is a method for producing a decorative foil, which, in a non-limiting manner, allows the foil to be saturated with anhydrous resin, which can be cured through UV light and / or electron beam, and which, despite the fact that it can have a high crosslinking density, while showing excellent mechanical properties in terms of the traction of the paper in the direction perpendicular to the plane of the surface of the paper, also known as internal bond strength or "Z strength", does not have shrinkage problems resulting from high crosslinking levels, which curl the product and strongly complicate its application. This object is achieved by the method of claim 1. The dependent claims give details of particular and / or preferred embodiments of the present invention.

[0010] More specifically, the present invention discloses a method comprising carrying out: The first step is to prepare the substrate; a second step of encapsulating one side of the substrate with a first resin; a third step of drying and / or curing the surface sealed with the first resin; a fourth step of impregnating said substrate with an anhydride resin containing radiation-curable functional groups on a surface of said substrate opposite to the surface sealed with the first resin; A fifth step of hardening the by-product obtained in the above steps; A sixth step of applying one or more layers of one or more resins to one of the two faces of the by-product obtained in the previous step, where at least one resin contains radiation-curable functional groups; and The seventh step is drying and / or curing the foil obtained after all the above steps.

[0011] In one embodiment of the present invention, the execution of the above processes is sequential in the order specified, however, in other practical embodiments of the present invention, there may be execution orders of the methods including, but not limited to, the addition of intermediate steps or duplication of steps.

[0012] In the present invention, it is necessary to highlight the difference between sealing with resin (second step) and impregnation with resin (fourth step). In this description, impregnation with resin means applying as much resin as the substrate can receive until said substrate is saturated with the applied resin (i.e. "clogged" with this resin). On the other hand, sealing with resin means creating a surface resin film or layer that makes the substrate impermeable, at least temporarily, to the impregnating resin.

[0013] The present invention also distinguishes between drying and curing of resins, since they are not technically equivalent. In the drying process, the solvent is extracted by evaporation, whereas in curing, a polymerization reaction takes place. Thus, according to this specification, the radiation curing process includes, in a non-limiting manner, both ultraviolet radiation processes and media and electron beam radiation processes and media, since both techniques are well known to those skilled in the art and are sources of radiant energy.

[0014] Thus, in the context of the present invention, a radiation curable resin means a resin that polymerizes upon exposure to a radiation source, such as, but not limited to, an ultraviolet radiation source or an electron beam.

[0015] In the present invention, inactivation takes two forms. One involves creating an inert atmosphere, most commonly using high purity nitrogen, to reduce the oxygen in the air in contact with the resin. The other is physical inactivation, which is achieved by eliminating the presence of oxygen from the surface by creating a physical barrier between the oxygen in the air and the surface. This can be done by (but is not limited to) directly contacting the resin with a film or the surface of the resin with a flat or cylindrical surface to prevent the presence of oxygen. For example, the resin could be contacted with a BOPET film to prevent contact of the uncured resin with oxygen.

[0016] In the present invention, a partially oxygen-enriched atmosphere refers to an atmosphere in which the presence of oxygen significantly inhibits surface curing. In systems in which the radiation-curable component is selected from unsaturated acrylate and methacrylate groups, the phenomenon of surface curing inhibition is observed when the oxygen level exceeds 200 ppm.

[0017] Thanks to the methods and products described herein, a good level of mutual and durable adhesion is obtained between the different layers of the decorative foil, while at the same time adhesion with the substrate is achieved, ensuring crosslinking and permanent covalent chemical bonds, all of which can use one or more chemical reaction mechanisms. The impregnation of the substrate can be colorless or pigmented and has the particularity of being formulated to achieve a certain resistance to different adverse weather conditions. In particular, the impregnation of the substrate can be formulated to show high color stability despite exposure to UV rays. As a result, it is possible to impregnate already printed substrates, minimizing the effects of degradation due to solar radiation.

[0018] This UV resistance is becoming increasingly important not only for outdoor applications, but also for surfaces used in medical and hospital applications where UV disinfection is more frequent.

[0019] Moreover, the present invention allows the decorative foil that integrates the panel to be completely saturated with a non-hygroscopic resin and made impermeable before bonding to the substrate, regardless of external factors, such as the resin of the substrate to be pressed, or the pressure and temperature process, in the case of HPL or CPL panels. Moreover, when bonded by an external adhesive, the impermeability of the decorative foil is not dependent on the adhesive used.

[0020] The above mentioned properties are particularly important. When relying on the transfer of resin or external additives, it has been observed that this is a very difficult process to control, since the external additives must be able to flow and at the same time the air trapped in the substrate must be sucked in. It has also been observed that it is difficult to ensure that no unsaturated areas remain, since outdoor use may allow moisture to seep in and cause the foil to deteriorate. It is very difficult to discover the effect before application, as it may be too late, since it is cumbersome to check whether any areas remain unsaturated. It must also be noted that in applications where the resin or adhesive flows through the substrate, it is difficult to obtain a covalent chemical bond, and delamination of the substrate and the resin may occur.

[0021] Moreover, the decorative foil of the present invention retains its adhesive power even under adverse conditions such as those associated with transportation and storage. Therefore, it is found that the resins currently applied, such as melamine-formaldehyde and phenol-formaldehyde, are resins in which the chemical reaction is slowed but not inhibited, and therefore have limited stability. In contrast, the resins used to ensure adhesion in the present invention do not undergo slow chemical reactions, so that their stability and complete adhesion are guaranteed for a much longer period of time, and there is no gradual decrease in adhesion due to the aging of the decorative foil, making it possible to extend the life of the product before use.

[0022] Finally, the decorative foil according to the invention has the particularity that it can be used on HPL or CPL panels or on two-dimensional plane or curved elements covered with a Finish-Foil and that, after impregnation with resin under the inventive method described, it can be printed using traditional techniques or even digital printing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] <Preferred embodiments and examples of the present invention> As mentioned above, the present invention discloses a method for producing a decorative foil and its result and its use in different types of panels, said method comprising the following steps: The first step is to prepare the substrate; a second step of encapsulating one side of the substrate with a first resin; a third step of drying and / or curing the surface sealed with the first resin; a fourth step of impregnating the substrate on a side of the substrate opposite the side sealed with the first resin with an anhydride resin containing radiation-curable functional groups; A fifth step of hardening the by-product obtained in the above steps; A sixth step of applying one or more layers of one or more resins to one of the two faces of the by-product obtained in the previous step, where at least one resin contains radiation-curable functional groups; and A seventh step is drying and / or curing the foil obtained after all the above steps.

[0024] Next, the present invention will be analyzed with practical examples that illustrate different practical embodiments and the method of the claims contained herein in a non-limiting manner. Throughout this specification, the term "embodiment" means that the features, structures, or specific characteristics described with respect to the embodiment are included in at least one embodiment of the present invention. Thus, the appearance of the term "one embodiment" in multiple places throughout this specification does not necessarily refer to the same embodiment, but is merely a descriptive, non-limiting reference. Furthermore, several embodiments and examples of the present invention may be referenced herein along with alternatives of their different components. Such embodiments, examples, and alternatives should not be construed as de facto equivalents between them, but as independent embodiments of the present invention. Furthermore, the features, structures, or characteristics described herein may be combined in any suitable manner in one or more embodiments. In this description, numerous specific details are provided to provide a comprehensive understanding of the embodiments of the present invention. However, one skilled in the art will recognize that the present invention can be practiced without one or more of these specific details, or by using other methods, components, materials, or additional steps in processes.

[0025] Below are described some practical non-limiting embodiments of how the different steps of the method of the present invention can be actually carried out. As mentioned above, these embodiments are only practical examples and cannot be combined into one. At the same time, unless otherwise indicated, all percentages and weights of resins given in the following examples are based on their dry weight.

[0026] First step: providing the substrate In a practical, non-limiting embodiment of the first step, 2 ~200g / m 2 , preferably 50 g / m 2 ~140g / m 2 , more preferably 60 g / m 2 ~120g / m 2A cellulose-based paper (foil) is provided having a weight of 5 g / m2. Furthermore, this paper foil may contain pigments and / or mineral fillers in its mass and / or have decorative effects obtained by traditional and / or digital printing known in the art. This paper thus constitutes the substrate for all other resin layers that are applied successively under the method of the invention. In a practical embodiment, a cellulose-based paper is used, but other types of materials, such as nonwovens, can also be used, in which case the weight is 5 g / m2 or more. 2 ~100g / m 2 , preferably 10 g / m 2 ~ and 60g / m 2 , more preferably 15 g / m 2 ~50g / m 2 It would be.

[0027] Second step: encapsulating one side of the substrate with a first resin Next, one side of the substrate is sealed with a first resin. The amount of resin should be sufficient to make one side of the substrate impermeable, so that it will hold back the liquid resin applied to the opposite side in the next step of the method of the present invention. In certain embodiments, such a layer of first resin used as a sealant contains oligomers, monomers, adhesion promoter additives, rheology modifiers, cross-linking agents capable of acting as chemical cross-linkers to ensure fixation with adjacent surfaces, or any combination thereof. As mentioned before, it is important to emphasize that there is no impregnation in this second step, i.e., the first resin does not completely fill the interior of the substrate, but an impermeable layer is created so that all other liquid resins applied in subsequent steps do not soak into the substrate.

[0028] In a particular embodiment for producing HPL panels, a first water-based resin, physically dryable and / or radiation curable, is used, diluted accordingly to adjust its viscosity and its penetration into the paper. Amorphous silica can be used as a thickener to adjust its viscosity and thixotropy. This first resin used in this example embodiment allows good sealing and impermeability thanks to a surface film obtained on one side of the substrate, which in this practical example is a decorative foil. Said impermeable layer is configured to prevent the penetration of a liquid resin that is subsequently applied on the opposite side of the substrate or paper. The loading of this first sealing resin is between 1 and 30 g / m 2 , preferably 2 to 25 g / m 2 , more preferably 5 to 20 g / m 2 Additionally, up to 20% of the dry weight of the first resin is blocked isocyanate (preferably 15% or less, more preferably 5-10% of the dry weight). It is also desirable to include a dispersion of blocked isocyanate having a rated unblocking temperature of greater than 110°C, particularly a rated unblocking temperature of 130°C or greater.

[0029] The first sealing resin described for this HPL panel example exhibits chemical functionality configured to extend covalent bonds with both adjacent layers in the final product (i.e., adjacent layers to the decorative foil completed by the method of the present invention) and cross-link appropriately, even if they do not share the same cross-linking chemistry, thus establishing links between chemical groups that do not naturally react between themselves.

[0030] Moreover, considering that the base substrate to which the foil in this example is applied is a kraft paper impregnated with phenol-formaldehyde resin, such resin cross-links with the blocked isocyanate available in the sealing layer during the high temperature and pressure pressing step, resulting in a decorated board or final product to which the paper resulting from the method of the present invention is applied.

[0031] In another particular embodiment for producing a finished foil, a sealing layer is applied which is also adhesive, for which purpose the sealing layer comprises a physically drying vinyl or vinyl-acrylic resin, such as a blocked isocyanate. In this way, the foil resulting from the method of the invention can be bonded via pressure and temperature, without the need to add other external adhesives. In this application, the weight of the applied sealing layer is between 1 and 80 g / m2, depending mainly on the substrate to which it is to be bonded. 2 , preferably 20 to 60 g / m 2 , more preferably 25 to 55 g / m 2 However, the amount of material that penetrates the substrate is still 1 to 30 g / m 2 , preferably 1 to 25 g / m 2 , more preferably 1 to 15 g / m 2 It would be.

[0032] Third step: Drying and / or curing the surface sealed with the first resin The substrate containing the first resin sealing layer is then immediately dried and / or cured in a third step. The drying and / or curing process is selected from, but not limited to, UV curing, electron beam curing, thermal initiator curing, moisture exposure curing, oxidation curing, thermal curing, water physical drying, solvent removal drying, or combinations thereof. Also, when adding thermally decomposable components such as blocked isocyanates to covalently react with adjacent layers, the drying and / or curing techniques applied can be adjusted to avoid premature reaction.

[0033] Fourth step: impregnating the substrate with an anhydride resin containing radiation-curable functional groups on the side of the substrate opposite the side sealed with the first resin. After drying and / or curing the first resin sealing one side of the substrate, the paper is impregnated with an anhydrous resin in an amount sufficient to saturate the substrate by impregnation on the side of the paper opposite to the side sealed with the first resin. In the process of the present invention, the impregnating resin can be a formaldehyde-free resin. The film formed by the first resin on one side of the substrate as described above makes the substrate impermeable, so that the second resin does not bleed out and contacts the support and conveying surfaces of the product production line, preventing contamination of the product and dirt on the contacted parts. In different embodiments, the anhydrous resin can be a transparent resin or a pigmented resin.

[0034] The sealing film formed by the first resin allows the application of the impregnating resin to the other side of the substrate, which may be a low molecular weight resin with a high density of functional groups and a very low viscosity, although it may be an anhydrous resin, a solvent, or formaldehyde. Therefore, even if only one side is impregnated, it is possible to quickly saturate the substrate by extracting all the air therein. It is possible to obtain a substrate with a sealing layer that may have chemical reactivity and properties different from the impregnation, without the problems that arise from such impregnation penetrating to the other side.

[0035] During the fourth step of the method, this anhydrous resin incorporated into the substrate ensures covalent crosslinking with adjacent layers of the finished final product, completely saturating the substrate and preventing subsequent moisture ingress (particularly important for outdoor applications exposed to adverse weather conditions). The anhydrous resin applied in this fourth step may include, but is not limited to, in different practical embodiments, oligomers, monomers, additives with suitable properties for obtaining covalent type interfacial crosslinking with adjacent layers, as well as pigments, filler nanoparticles, rheology modifiers, humectants, compatibilizers, UV absorbers, light stabilizers, flame retardants, thermal polymerization initiators and / or mixtures of any combination of the above.

[0036] To obtain a strong network of crosslinked polymers in the substrate body, the anhydride resin applied in the fourth step may include, but is not limited to, methacrylic and acrylic monomers and / or oligomers with a global functionality preferably of 2 or more, optionally including multifunctional softening oligomers and / or chain extenders that can modify the flexibility of the product by combining different mono- and multifunctional monomers that can generate a network.

[0037] Optionally, oligomers or oligomer mixtures can be used, which can include, as oligomer precursors, a combination of epoxy acrylates, preferably polyester acrylates, more preferably urethane acrylates and / or their corresponding methacrylates, together with acrylate monomers and their corresponding mono- and multifunctional methacrylates, all of which can also incorporate hydroxylated functional groups (-OH) and / or free or blocked isocyanate functional groups (-N=C=O). Acrylate oligomers can also be used, as well as the corresponding methacrylates containing functional groups and / or ethoxylated melamine groups in their chains.

[0038] In certain embodiments, acrylate monofunctional monomers having a hydroxylated end group (-OH) are added to the mixture, such as, but not limited to, 4-hydroxybutyl acrylate (4-HBA), 2-hydroxypropyl acrylate (HPA), 2-hydroxyethyl acrylate (HEA), carboxyethyl acrylate (CEA), and their corresponding methacrylates.

[0039] In another particular embodiment, the use of HDDA monomers (hexanediol diacrylate monomers) difunctional alone shows a very high ability to penetrate the paper structure, which allows the air trapped between the cellulose fibers to be easily extracted, giving the compound a high degree of saturation. In another embodiment, for clear-finished paper, UV-absorbing additives can be used, as well as light stabilizers and / or metallic pigments and / or iridescent pigments (synthetic mica). Finally, in another embodiment, the second resin can include amorphous silica as a thickener, configured to adjust the viscosity and give the mixture a thixotropic behavior.

[0040] Fifth step: Curing the by-product obtained in the above steps The method of the invention then supports at least partially curing the by-products obtained by carrying out steps 1 to 4, obtaining a cure that allows even rolling the paper, if necessary, while at the same time ensuring chemical anchor points and reactivity connecting adjacent layers in the coating.

[0041] The curing method may be selected from, but is not limited to, electron beam curing, ultraviolet light curing, thermal initiator curing, moisture curing, oxidation curing, heat curing, or a combination thereof.

[0042] Preferably, the foil obtained from the previous step is cured by electron beam and / or UV light, more preferably by electron beam (EB). In all cases, it can also be cured by exposure to, but not limited to, moisture, oxidation, thermal mechanisms, two-component resin polymerization, free and / or blocked isocyanate polymerization, obtaining interconnections by crosslinking all layers, thus ensuring interfacial adhesion and achieving hardening of all previously applied layers.

[0043] The problem of warping is one of the main issues with this type of product and occurs when one layer of the foil shrinks differently than another, creating tensions that cause the foil to become unbalanced. This warping occurs during drying and / or curing and can be more or less severe depending mainly on the resin used.

[0044] In one embodiment, the curing is performed by electron beam. In this embodiment, although there is a problem that a resin with high crosslink density is used for impregnation, leading to strong warping, this is minimized thanks to the method of the present invention, and by performing this partial curing of the substrate without yet applying a subsequent layer, the substrate may be allowed to shrink more freely. Thus, by controlling the uncured functional groups, it is possible to control the amount of remaining shrinkage and to adjust it so that the desired shrinkage is left to the next curing step.

[0045] In this embodiment, the process allows greater control of one of the key points since the cure can be tuned to obtain a flat finished foil. In this embodiment, it has been found that both the dose and voltage can be tuned, as well as the amount of oxygen at the surface, to control the warpage without compromising adhesion to the adjacent layer(s). Thus, in an example using electron beam curing: The number of electrons emitted from the device can be adjusted by the dose, so that the amount of crosslinking on the surface through which the electrons penetrate can be controlled. It is desirable to use a dose of 1 to 90 kGy. The voltage can adjust the electron transmission curve. When the voltage is in the low range, the transmission curve appears very steep and the dose decreases rapidly as the electrons enter the material. It is advisable to use a voltage between 80 and 300 kV. To obtain a chemically active surface, an inert atmosphere partially enriched in oxygen may be used, or it is also possible to carry out surface hardening without an inert atmosphere, where oxygen inhibits the surface hardening partially or completely on at least one of the foil's two sides.

[0046] By adjusting these parameters, the residual shrinkage can be adjusted in terms of both amount and distribution. It is also possible to obtain a less polymerized surface or an asymmetric distribution by adjusting the voltage and / or the surface oxygen level.

[0047] Surprisingly, it has been found that the process of the present invention allows the use of acrylic resins with a high density of unsaturated groups without detrimental warping effects, minimizing the inherent weakness of highly crosslinked systems, and even more surprisingly, after this e-beam curing, the high density of reactive groups remains active at the surface, even resulting in a stoichiometric excess with respect to the reactive groups of the adjacent layers.

[0048] All of this allows substrates highly saturated with translucent resins (optionally containing pigments) to exhibit high color stability when exposed to UV light, high crosslinking and internal cohesion to allow for tunable shrinkage in subsequent steps of the curing process, tunable viscosity, easy winding and printing, and high reactive groups at the interface with adjacent layers to ensure covalent bonding.

[0049] In a variation of the particular embodiment above, the radiation curable resin is endowed with hydroxylated (-OH) and free isocyanate functionality. In this application, the curing is performed by electron beam as in the previous embodiment, but a thermal cure step can be combined before or after the radiation cure to promote the reaction of the free isocyanate, especially at the surface, and contribute to a tack-free surface, which can be achieved with only a small surface cure step of the radiation curable resin. This system can be cured in an oxygen-rich inert atmosphere or cured under an inert atmosphere.

[0050] In another particular embodiment, thermal curing is carried out on a substrate that is pre-impregnated with a resin consisting of radiation curable functional groups, hydroxylated groups, free and / or blocked isocyanates together with a thermal initiator, followed by a thermal curing step of the free and / or blocked isocyanates, reserving the radiation curable groups and optionally blocked isocyanate groups from reacting, thereby allowing them to form covalent bonds with adjacent layers.

[0051] Optional first step: printing the decorative design Optionally, the method includes a step of printing a decorative design on one of the faces of the by-product obtained by carrying out the first to fifth steps. In a particular embodiment, a digital printer is used and the printed image is partially cured by UV light and / or electron beam. During partial curing, the image is fixed onto the decorative foil, but at the same time some of the reactive groups on the surface are activated so that they can establish covalent bonds with the subsequent layer, i.e. the layer formed by radiation curable resin upon irradiation in the sixth step.

[0052] Sixth step: applying one or more layers of one or more resins to one of the two faces of the by-product obtained in the previous step, where at least one of the resins contains radiation-curable functional groups. In this sixth step, one or several resins are applied (i.e., it can be one resin or several layered resins), at least one of which contains radiation curable functional groups, and can be cured to a thickness between 10 and 300 μm by exposure to, but not limited to, moisture, oxidation, thermal mechanisms, two-component resin polymerization, blocked isocyanate polymerization, or other types of radiation other than ultraviolet light or electron beams, on either side of the surface of the by-product obtained from the first to fifth steps and the optional decorative design printing step.

[0053] The resins used in this sixth step may include, but are not limited to, oligomers, monomers, additives with suitable functionality to obtain interfacial crosslinking with adjacent layers, as well as fillers to improve mechanical scratch hardness and abrasion resistance, nanoparticles, short fibers, pigments, rheology modifiers, humectants, surface tension modifiers, sun protection additives, antioxidants, vandal prevention agents (e.g., anti-graffiti), anti-soiling additives, antimicrobial agents, flame retardants, infrared reflective additives, antistatic agents, anti-fingerprint agents, or any combination of the above.

[0054] In a particular embodiment, the radiation-curable component is selected from unsaturated acrylate and methacrylate groups. In another particular embodiment, such radiation-curable component is formed by an epoxy acrylate oligomer, preferably an acrylate polyester oligomer, in particular a urethane acrylate oligomer or its corresponding methacrylate oligomer, such as a radiation-polymerizable polymer, where appropriate diluted with monofunctional and / or polyfunctional acrylate monomers and / or their corresponding methacrylates. In another particular embodiment, for enhancing color stability when exposed to UV light, the prepolymer is an aliphatic urethane acrylate oligomer, appropriately diluted with 1,6-hexanediol diacrylate monomer (HDDA).

[0055] In a particular embodiment of this step, it is desirable to apply none, one or several layers of said resin on the second paper or foil (optionally surface-treated with a release-effect resin). The foil may be made of, but is not limited to, biaxially oriented polyethylene terephthalate (BOPET) or biaxially oriented paraffin thermoplastic resin, in particular BOPP, and may have a thickness of 19 to 90 μm, more preferably 20 to 50 μm. By mechanical bonding by calendaring, the faces of the two foils are placed in contact, on the one hand, with this second foil and, on the other hand, with the face of the foil to which the layer or layers of resin have been applied as described above.

[0056] Optional second step: application of one or more layers of adhesion-promoting and / or adhesive resins Optionally, the method of the present invention includes applying one or more layers of a resin(s) that promotes adhesion and / or acts as an adhesive on the side opposite to where the layer(s) in the sixth step have or will be applied, after which, if necessary, a drying and / or curing step can be applied selected from, but not limited to, UV curing, curing by electron beam irradiation, curing by thermal polymerization initiator, curing by exposure to moisture, curing by oxidation, physical drying of water, drying by solvent removal, or any combination of the above processes.

[0057] In an embodiment for producing HPL, a water-based physically drying and / or radiation curable resin is used. The amount of this first sealing resin is 1-30 g / m 2 , preferably 2 g / m 2 ~25g / m 2 , more preferably 2 g / m 2 ~10g / m 2 It has further been found desirable to include up to 10% blocked isocyanate based on the dry weight of the first resin. In this embodiment, the blocked isocyanate preferably has a rated unblocking temperature of greater than 110° C., particularly greater than or equal to 130° C.

[0058] In another particular embodiment for producing a finished foil, an adhesive layer is applied that comprises a physically drying vinyl or vinyl-acrylic resin (containing a blocked isocyanate). In this way, the foil resulting from the process of the invention is bondable by pressure and temperature, without the need for the addition of other adhesives. In this application, the weight of the resin layer is between 1 and 80 g / m2. 2 is applied, preferably 20 to 60 g / m 2 , more preferably 25 to 55 g / m 2 It is.

[0059] Seventh step: drying and / or hardening of the product obtained after all the above steps. The drying and / or curing method may be selected from, but is not limited to, curing by electron beam, curing by ultraviolet light, curing by a thermal polymerization initiator, curing by moisture, curing by oxidation, heat curing, drying by solvent removal, or a combination thereof.

[0060] Preferably, the foil obtained from the previous step (possibly including optional steps) is cured by electron beam and / or UV light, more preferably by electron beam (EB). In any case, it can also be cured by exposure to, but not limited to, moisture, oxidation, thermal mechanisms, two-component resin polymerization, blocked isocyanate polymerization, in order to obtain cross-linked interconnection of all layers, thereby ensuring interfacial adhesion and achieving curing of all previously applied layers.

[0061] In a particular embodiment, curing is performed by electron beam, applying a dose of 1-90 kGy, preferably 10-80 kGy, more preferably 20-60 kGy, at a voltage of 80-300 kV, preferably 100-300 kV, more preferably 150-300 kV, under physically inert conditions or under inert atmosphere conditions with an oxygen content of less than 1000 ppm, preferably less than 500 ppm, more preferably less than 200 ppm.

[0062] Having provided a detailed description of the method of the present invention, a series of non-limiting examples of some practical applications of the present invention will now be described.

[0063] <Example 1> 70g / m2 with decorative printing on the surface 2 Prepare a decorative paper (high in pigment mass, as known in the art).

[0064] Next, in a practical embodiment of the second step of the method of the present invention, a radiation-curable group-containing water-based physically drying urethane acrylate resin to which a blocked isocyanate water-based dispersion has been added is added in an amount of 7 g / m2 in terms of dry weight. 2 The opposite side of the decorative print is sealed by applying it with a roller coater.

[0065] In a non-limiting practical embodiment, this first resin consists of a Lamberti ESACOTE® LX 101 dispersion with a solids content of 34% to 36% and Covestro Bayhydur BL2867 incorporating an aqueous dispersion of blocked isocyanate with a reagent content of 38%, such that the dry content of the second product is 5% with respect to the solids content of the resin. The difunctional monomer hexanediol diacrylate (HDDA) is incorporated in the mixture in a proportion of 10%, based on the dry content of the resin.

[0066] The obtained by-product is physically dried (third step of the invention) in a drying tunnel sprayed with hot air at a temperature of 100° C. so as not to induce reaction of the blocked isocyanate, which represents a non-limiting practical example of the third step of the method of the invention.

[0067] Then, in the fourth step, the opposite side of the substrate or paper is impregnated. This is done, but not exclusively, with a roller coater and the excess is removed with a blade. For this, 35 g / m2 of resin consisting of only radiation-curable HDDA monomers is applied. 2 To this is added 1% of the UV absorber TINUVIN 400 and 1% of the light stabilizer HALS TINUVIN 292. This resin exhibits a very low viscosity and penetrates very easily, completely saturating the part of the substrate constituted between the surface resulting from the first resin and the sealing film.

[0068] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 200 kV, give said side an oxygen content of 500 ppm, and physically inactivate the sealed side.

[0069] In this non-limiting example, and after the steps described, the blank is wound up for further processing in subsequent steps.

[0070] On the previously prepared material, 80 g / m 2 The urethane acrylate resin EBECRYL 284 was diluted with TINUVIN 400 1% + light stabilizer HALS TINUVIN 292 1% and HDDA monomer at a shear rate of 1000 s -1 A third layer is applied having an applied viscosity of 2000 mPa·s at 25° C., measured at 200° C. This corresponds to the sixth step of the method of the invention.

[0071] Finally, the sixth step side is cured with an electron beam at a dose of 60 kGy and a voltage of 200 kV. This process is carried out under an inert atmosphere with an oxygen content of less than 200 ppm on the sixth step side and physical inactivation on the opposite side to achieve a full radiation deep cure of all layers, preserving the blocked isocyanate functionality of the sealing layer.

[0072] The finished products are then placed, with the decorated side facing outwards, on a pile of craft paper sheets soaked in phenol-formaldehyde resin, and then heated at a temperature of 160°C and a pressure of 80kg / cm. 2 During this pressing process, the phenolic resin crosslinks with the blocked isocyanate present at the interface to obtain a covalent chemical bond, preventing the ingress of water and atmospheric chemicals, ensuring chemical adhesion between the foil of the present invention and the substrate sheet, with a strength of 3 N / mm 2 Surface tensile strength values ​​(Z strength according to DIN 52366) of 0.1 to 0.5 mm or more are achieved.

[0073] <Example 2> 70g / m2 with decorative printing on the surface 2 A decorative paper (known in the art and having a high pigment mass) is prepared. Then, a urethane acrylate-based physically drying resin (i.e., a first water-based resin containing a radiation-curable group) is applied to the paper with a dry weight of 7 g / m2 using a roller coater. 2 The application seals the printed surface, which represents a non-limiting embodiment of the first two steps of the method.

[0074] The encapsulation resin mix consists of an aqueous dispersion of MIWON MIRAMER W8365NT with a solid content of 43%, to which the difunctional monomer hexanediol diacrylate (HDDA) is added in a proportion of 8% based on the dry weight of the resin. The resulting paper foil is subjected to physical drying, i.e., initial curing and / or drying, in a drying tunnel with hot air injection.

[0075] The substrate or paper is impregnated on the other side with a roller coater and the excess is removed with a blade (fourth step). For this purpose, 35 g / m2 of resin consisting of radiation-curable HDDA monomers is applied. 2 This resin, i.e. the resin applied in the fourth step of the method of the invention, exhibits a very low viscosity and penetrates very easily, completely saturating the portion of the substrate that is constituted between the surface and the sealing film of the first resin.

[0076] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 135 kV and an oxygen content of 500 ppm on that side, and physical passivation on the sealed side, in this example after these steps the blank is wound up for further processing in subsequent steps.

[0077] Afterwards, the same type of resin as described in the sixth step of Example 1 is applied, but this time on the side on which the first resin was applied. On the side impregnated with the second resin, 5 g / m of the sealing mixture (i.e. the third resin, which is the same as the first resin in Example 1) is applied. 2 Apply and follow the same drying and / or curing steps as from Example 1.

[0078] Finally, the product is subjected to a final curing step by applying an electron beam to the sixth step side at a dose of 60 kGy and a voltage of 225 kV, under an inert atmosphere with an oxygen content of less than 200 ppm on the sixth step side and physical inactivation on the opposite side, achieving a complete deep radiation cure of all layers, thereby preserving the blocked isocyanate functionality on the sealing layer.

[0079] The finished products are placed in order, with the decorated side facing outward, on a pile of craft paper sheets soaked in phenol-formaldehyde resin, and then heated at a temperature of 160°C and a pressure of 80 kg / cm. 2 During this pressing process, the phenolic resin crosslinks with the blocked isocyanate present at the interface to obtain a covalent chemical bond, preventing the ingress of water and atmospheric chemicals, ensuring chemical adhesion between the foil of the present invention and the substrate sheet, with a strength of 3 N / mm 2 Surface tensile strength values ​​(Z strength according to DIN 52366) of 0.1 to 0.5 mm or more are achieved.

[0080] <Example 3> 80g / m 2 A physically drying urethane acrylate resin containing radiation curable groups was mixed with a water-based dispersion of blocked isocyanate and applied to a white base paper with a roller coater until the dry weight reached 7 g / m. 2 and seal one of the two sides of the white base paper.

[0081] In a non-limiting practical embodiment, this first resin consists of a Lamberti ESACOTE® LX 101 dispersion with a solid content of 34% to 36%, Covestro Bayhydur BL2867 incorporates a blocked isocyanate aqueous dispersion with a reagent content of 38%, the proportion of the second product being 5% with respect to the solid content of the resin. The difunctional monomer hexanediol diacrylate (HDDA) is incorporated into the mixture at a proportion of 10% based on the dry content of the resin.

[0082] The obtained by-product is physically dried in a drying tunnel spraying hot air at a temperature of 100° C. so as not to induce a reaction from the blocked isocyanate (third step of the present invention), which corresponds to a non-limiting practical embodiment of the third step of the method of the present invention.

[0083] The paper is then impregnated with anhydrous resin using a roller coater and the excess is removed with a blade. For this purpose, 40 g / m2 of resin made from HDDA monomers is applied. 2 and 20% white pigment KRONOS 2220, 1% UV absorber TINUVIN 400, and 1% light stabilizer HALS TINUVIN 292. This resin has a low viscosity, penetrates very easily, and completely saturates the paper.

[0084] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 200 kV, imparting an oxygen content of 500 ppm to said side, and physically inactivating the sealed side.

[0085] The surface impregnated with the second resin is then printed with a digital printer using a photoreactive ink containing inorganic pigments, and the printed image is partially cured by exposure to UV light, fixing the image to the paper as it cures, but at the same time leaving the reactive groups active and able to form covalent bonds with the next layer.

[0086] On the printed side of the previously prepared material, another layer is applied: a third resin. This layer is 80 g / m 2 The urethane acrylate resin Ebecryl 4680 was mixed with 1% Tinuvin 400 and 1% light stabilizer Tinuvin 292, diluted with HDDA monomer, and heated at a shear rate of 1000 s -1 The coating viscosity measured at 25°C is 2000 mPa·s.

[0087] Finally, the product is subjected to a final curing step by applying an electron beam on the sixth step side with a dose of 60 kGy and a voltage of 200 kV, under an inert atmosphere with an oxygen content of less than 200 ppm on the sixth step side and physical inactivation on the opposite side, achieving a complete deep radiation cure of all layers, thereby preserving the blocked isocyanate functionality on the sealing layer.

[0088] The finished products are then placed, with the decorated side facing outwards, on a pile of craft paper sheets soaked in phenol-formaldehyde resin, and then heated at a temperature of 160°C and a pressure of 80kg / cm. 2 During this pressing process, the phenolic resin crosslinks with the blocked isocyanate present at the interface to obtain a covalent chemical bond, preventing the ingress of water and atmospheric agents, thus ensuring chemical adhesion between the foil of the present invention and the substrate sheet, with a strength of 3 N / mm 2 Surface tensile strength values ​​(Z strength in accordance with DIN 52366) of 0.1 to 0.5 mm or more are achieved.

[0089] <Example 4> 80g / m 2 A physically drying urethane acrylate resin containing a radiation curable group (i.e., a first water-based resin) was applied to a white base paper (known in the art and having a high pigment mass) in an amount of 7 g / m2 in dry weight. 2 One side of the white base paper is sealed by applying the coating with a roller coater, which corresponds to a non-limiting embodiment of the first two steps in this method.

[0090] The encapsulation resin mix is ​​a water-based dispersion of MIWON MIRAMER W8365NT with a solid content of 43%, to which the bifunctional monomer hexanediol diacrylate (HDDA) has been added at a rate of 8% based on the dry weight of the resin. This resin layer has two functions: it creates a membrane to prevent the impregnation liquid from seeping in, and it also prepares the outer surface for the subsequent printing step. Due to its chemical composition, this thin membrane allows the ink to penetrate slightly to the surface, improving fixation. The finished paper foil is then physically dried in a drying tunnel sprayed with hot air.

[0091] The paper is then impregnated with anhydrous resin using a roller coater and the excess is removed with a blade. For this purpose, 40 g / m2 of resin made from HDDA monomer is applied. 2 and 20% white pigment KRONOS 2220, 1% UV absorber TINUVIN 400, and 1% light stabilizer HALS TINUVIN 292. This resin has a low viscosity, penetrates very easily, and completely saturates the paper.

[0092] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 135 kV and an oxygen content of 500 ppm on that side, and physical inactivation on the sealed side, After these steps, the blank is wound up for further processing in the subsequent steps.

[0093] The surface impregnated with the first resin is then printed with a digital printer using a photoreactive ink containing inorganic pigments, and the printed image is partially cured by exposure to UV light, fixing the image to the paper as it hardens, but at the same time leaving the reactive groups active and able to form covalent bonds with the next layer.

[0094] On the printed side of the previously prepared material, another layer is applied: a third resin. This layer is 80 g / m 2Add 1% Tinuvin 400 and 1% light stabilizer Tinuvin 292 to the urethane acrylate resin Ebecryl 4680, dilute with HDDA monomer, and adjust the coating viscosity at 25°C to 2000 mPa s (shear rate 1000 s -1 On the surface on which the second resin was applied, a sealing mixture (i.e., a third resin identical to the first resin in Example 1) was applied at a rate of 5 g / m 2 Apply and follow the same drying and / or curing steps as from Example 1.

[0095] Finally, the product is subjected to a final curing step by applying an electron beam on the sixth step side with a dose of 60 kGy and a voltage of 225 kV, under an inert atmosphere with an oxygen content of less than 200 ppm on the sixth step side and physical inactivation on the opposite side, achieving a complete radiation-induced deep cure of all layers, thereby preserving the blocked isocyanate functionality of the sealing layer.

[0096] The finished products are then placed on top of a pile of craft paper sheets soaked in phenol-formaldehyde resin, with the decorated side facing outwards, and then heated at a temperature of 160°C and a pressure of 80kg / cm. 2 During this pressing process, the phenolic resin crosslinks with the blocked isocyanate present at the interface to obtain a covalent chemical bond, preventing the ingress of water and atmospheric agents, thus ensuring chemical adhesion between the foil of the present invention and the substrate sheet, with a strength of 3 N / mm 2 Surface tensile strength values ​​(Z strength in accordance with DIN 52366) of 0.1 to 0.5 mm or more are achieved.

[0097] <Example 5> 80g / m 2 A radiation curable resin with a solid content of 100% is applied at a rate of 8 g / m2 onto a decorative white paper (known for its traditional techniques and with a high pigment content). 2 The white side is sealed by applying the adhesive with a roller coater.

[0098] The encapsulation resin mixture was prepared by diluting 4-functional polyester acrylate MIWON Miramer P2291 with 2-functional monomer HDDA at a shear rate of 1000 s -1 The viscosity was measured at 25 °C and was set to 1000 mPa·s. It contains 5% blocked isocyanate, 100% solids Covestro Desmodur BL1100 / 1 and 3% surface photoinitiator CIBA Darocure 1173 2-hydroxy-2-methylpropiophenone (CAS number 7473-98-5).

[0099] The foil obtained is partially chemically dried on the surface by UV irradiation, taking special care that the temperature during said exposure is such that the reaction of the blocked isocyanates is not induced. The substrate is impregnated on the other side with a roller coater and the excess is removed with a blade. For this purpose, 40 g / m2 of a resin consisting of radiation-curable HDDA monomers is applied. 2 is necessary (i.e. impregnation with a second resin).

[0100] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 200 kV and an oxygen content of 500 ppm on that side, and a physical passivation on the sealed side. After these steps, the blank is wound up for further processing in the subsequent steps.

[0101] The surface of the material prepared above, opposite to the side containing the sealing resin, was subjected to a shear rate of 1000 s -1 The acrylate urethane resin EBECRYL 284 was diluted with HDDA monomer and 8% oxidized yellow pigment Lanxess Bayferrox 3910 at a concentration of 50 g / m2 to give a coating viscosity of 2200 mPa s at 25 °C, as measured by the FT-IR spectrophotometer. 2 Apply a layer with.

[0102] On one side of the microstructured "release foil" BOPET film, 50 g / m 2The urethane acrylate resin EBECRYL 284 was mixed with 25% Nanocryl nanoparticles, Tinuvin 400 + 1% light stabilizer Tinuvin 292, and diluted with HDDA monomer to achieve a coating viscosity of 2200 mPa s (1000 s) at 25 °C. -1 The liquid surfaces of both foils are brought into contact with a calendar and then cured by electron beam.

[0103] Finally, the product is subjected to a final curing step by applying an electron beam on the side of the sixth step with a dose of 60 kGy and a voltage of 225 kV. This is done under physical inactivation conditions on both sides to achieve complete radiation curing of all layers, thus preserving the blocked isocyanate functionality of the sealing layer. When the PET is separated, it is confirmed that the foil of the present application has a microstructure that survives high temperature and pressure pressing.

[0104] The finished products are then placed, with the decorated side facing outwards, on a pile of craft paper sheets soaked in phenol-formaldehyde resin, and then heated at a temperature of 160°C and a pressure of 80kg / cm. 2 During this pressing process, the phenolic resin crosslinks with the blocked isocyanate present at the interface to obtain a covalent chemical bond, preventing the ingress of water and atmospheric agents, thus ensuring chemical adhesion between the foil of the present invention and the substrate sheet, with a strength of 3 N / mm 2 Surface tensile strength values ​​(Z strength in accordance with DIN 52366) of 0.1 to 0.5 mm or more are achieved.

[0105] <Example 6> 80g / m2 with decorative printing on the surface 2 A physically drying urethane acrylate resin with a radiation curable group was applied to the side opposite the design of the decorative paper (known for its traditional techniques and high pigment content) with a roller coater at a dry weight of 7 g / m. 2The sealing resin is a dispersion of ESACOTE (registered trademark) LX 101 manufactured by Lamberti, and the solid content is 34% to 36%.

[0106] The difunctional monomer hexanediol diacrylate (HDDA) is added to the mixture at a rate of 6% based on the resin dry matter and the monofunctional hydroxylated monomer (-OH) is added at a rate of 4% based on the resin dry matter. The resulting paper foil is physically dried in an evaporation oven with a hot air jet.

[0107] The other side of the substrate is impregnated with a roller coater and the excess is removed with a blade. For this purpose, 40 g / m2 of resin consisting of radiation-curable HDDA monomer is applied. 2 It is necessary to use 1% UV absorber Tinuvin 400 and 1% light stabilizer HALS Tinuvin 292. This resin has a very low viscosity and penetrates very easily, allowing it to completely saturate the paper.

[0108] The paper saturated with the first and second resins in the previous step is then subjected to electron beam irradiation to give the impregnated side a dose of 20 kGy, 200 kV and an oxygen content of 500 ppm on that side, and a physical passivation on the sealed side, after these steps the blank is wound up for further processing in the subsequent steps.

[0109] On the printed side of the previously prepared material, another layer is applied: a third resin. This layer is 80 g / m 2 The urethane acrylate resin Ebecryl 4680 was mixed with 1% Tinuvin 400 and 1% light stabilizer Tinuvin 292, diluted with HDDA monomer, and heated at a shear rate of 1000 s -1 The coating viscosity measured at 25°C is 2000 mPa·s.

[0110] Finally, the product is subjected to a final curing step by applying an electron beam with a dose of 60 kGy and a voltage of 200 kV on the sixth step side, under an inert atmosphere with an oxygen content of less than 200 ppm on the sixth step side, and physical inertness on the opposite side, to achieve full radiation curing of all layers.

[0111] The product developed in this example is bonded to an aluminum honeycomb panel using a hot melt polyurethane water reactive adhesive (PUR), and in this example, a matching aluminum square is also wrapped. A covalent chemical bond is obtained between the polyurethane reactive adhesive and the -OH functional groups, ensuring excellent adhesion, preventing water ingress, providing strong resistance to atmospheric agents, and ensuring mechanical adhesion between the laminate product object of this patent and the substrate to which it is bonded.

[0112] Finally, while the foregoing embodiments illustrate the principles of the present invention in one or more particular applications, it will be apparent to those skilled in the art that numerous changes in the form, use and details of implementation may be made without the exercise of inventive activity and without departing from the principles and concepts of the present invention as set forth in the following claims. Exemplary embodiments of the present invention are described below. <1> A method for producing a decorative foil, comprising: The first step is to prepare the substrate; a second step of encapsulating one surface of the substrate with a first resin; a third step of drying and / or curing the surface sealed with the first resin; a fourth step of impregnating the substrate on a side of the substrate opposite the side sealed with the first resin with an anhydride resin containing radiation-curable functional groups; The fifth step is to harden the by-product obtained in the above steps; a sixth step of applying one or more layers of one or more resins to one of the two faces of the by-product obtained in the previous step, where at least one resin contains radiation-curable functional groups; A seventh step is drying and / or curing the foil obtained after all the above steps. <2> The substrate is Weight 25g / m 2 ~200g / m 2 , preferably 50 g / m 2 ~140g / m 2 , more preferably 60 g / m 2 ~120g / m 2 or Weight 5g / m 2 ~100g / m 2 , preferably 10 g / m 2 ~60g / m 2 , more preferably 15 g / m 2 ~50g / m 2 Nonwoven fabric Consists of: <1> The method according to <3> the type of first resin is selected from physically drying, radiation curable, thermal initiator induced polymerization, crosslinking between hydroxylated groups and free and / or blocked isocyanates, and any combination thereof; The first resin further comprises: When configured to promote adhesion, the weight is 1 g / m 2 ~30g / m 2 , preferably 2 g / m 2 ~25g / m 2 , more preferably 5 g / m 2 ~20g / m 2 and When configured to act as an adhesive, the weight is 1 g / m 2 ~80g / m 2 , preferably 20 g / m 2 ~60g / m 2 , more preferably 25 g / m 2 ~55g / m 2 The amount of resin that penetrates the substrate is 1 g / m 2 ~30g / m 2 , preferably 1 g / m 2 ~25g / m 2 , more preferably 1 g / m 2 ~15g / m 2 That is, <1> or <2> The method according to <4> During the third step, the drying and / or curing process is carried out by at least one process selected from ultraviolet curing, electron beam irradiation, physical drying; <1> ~ <3> 2. The method according to claim 1 , wherein <5> In the fourth step, the radiation curable functional groups are reacted with thermal initiators, and / or hydroxylated groups and free and / or blocked isocyanates. <1> ~ <4> 2. The method according to claim 1 , wherein <6> the resin from the fourth step comprises 50% or more, preferably more than 75%, more preferably more than 85% of monomers having unsaturated acrylate and / or methacrylate groups; <1> ~ <4> 2. The method according to claim 1 , wherein <7> In a fifth step, curing is carried out by electron beam at a dose of 1-90 kGy, preferably 10-80 kGy, more preferably 20-60 kGy, at a voltage of 80-300 kV, preferably 100-300 kV, more preferably 120-250 kV, and at an oxygen content ranging from the lowest value obtainable by physical inerting techniques up to a concentration equivalent to the natural oxygen content in the atmosphere; <1> ~ <6> 2. The method according to claim 1 , wherein <8> The curing may be carried out under a partially oxygen-enriched inert atmosphere or without inertization, so that oxygen partially or completely inhibits surface curing on at least one of the two faces of the foil; <7> The method according to <9> an optional step of printing a decorative design on any surface, which can be performed after the fifth step of curing and before the sixth step of applying one or more layers of one or more radiation curable resins; <1> ~ <8> 2. The method according to claim 1 , wherein <10> Digital printing is used, where the ink is partially cured with UV light and / or an electron beam; When partially cured, the image is fixed on the decorative foil, but at the same time at least a portion of the surface reactive groups remain active so as to be able to establish covalent bonds with a subsequent layer in a sixth step. <9> The method according to <11> an optional step, before or after the sixth step, of applying one or more layers of one or more adhesion promoting and / or adhesive resins; One or more layers of such one or more adhesion promoting and / or adhesive resins may be applied to the surface opposite to the surface on which the sixth step has been or will be performed, followed by a drying and / or curing step, if required. <1> ~ <10> 2. The method according to claim 1 , wherein <12> the one or more adhesion promoting and / or adhesive layers are selected from physically drying, radiation curable, thermal initiator induced polymerization, crosslinking between hydroxylated groups and free and / or blocked isocyanates, and any combination thereof; When such resin or resins are configured to promote adhesion, the weight is 1 g / m 2 ~30g / m 2 , preferably 2 g / m 2 ~25g / m 2 , more preferably 2 g / m 2 ~10g / m 2 and When such resin or resins are configured to act as adhesives, the weight is 10 g / m 2 ~80g / m 2 , preferably 20 g / m 2 ~60g / m 2 , more preferably 25 g / m 2 ~55g / m 2 That is, <11> The method according to <13> In the seventh step, the curing is carried out by electron beam at a dose of 1-90 kGy, preferably 10-80 kGy, more preferably 20-60 kGy, at a voltage of 80-300 kV, preferably 100-300 kV, more preferably 150-250 kV, under physically inert conditions or in an inert atmosphere with an oxygen content of less than 1000 ppm, preferably less than 500 ppm, more preferably less than 200 ppm; <1> ~ <12> 2. The method according to claim 1 , <14> the radiation curable component is selected from unsaturated acrylate and methacrylate groups; <1> ~ <13> 2. The method according to claim 1 , <15> the radiation-curable component in the sixth step is formed from an epoxy acrylate oligomer, preferably a polyester acrylate oligomer, in particular a urethane acrylate oligomer or a corresponding methacrylate oligomer, such as a radiation-polymerizable polymer, if appropriate diluted with mono- and / or polyfunctional acrylate monomers and / or their corresponding methacrylates, <1> ~ <14> 2. The method according to claim 1 , <16> The prepolymer in the sixth step is an aliphatic urethane acrylate oligomer appropriately diluted with a diacrylate or triacrylate monomer; <1> ~ <15> 2. The method according to claim 1 , wherein <17> In a panel selected from HPL panels, CPL panels and 2D flat or curved elements backed with a finishing foil, <1> ~ <16> 2. Use of a decorative foil obtained by any of the methods according to claim 1.

Claims

1. A method for producing a decorative foil, comprising: A first step of providing a substrate; a second step of sealing one surface of the substrate with a first resin to produce an impermeable surface layer on the one surface without filling the interior of the substrate; a third step of drying and / or curing the surface sealed with the first resin; a fourth step of impregnating the substrate on a side of the substrate opposite the side sealed with the first resin with an anhydride resin containing radiation-curable functional groups in an amount sufficient to saturate the substrate by impregnation; a fifth step of hardening the product obtained in the first to fourth steps; a sixth step of applying one or more layers of one or more resins to one of the two faces of the product obtained in the first to fifth steps, where at least one resin contains radiation-curable functional groups; A seventh step of drying and / or curing the foil obtained from the first to sixth steps.

2. The substrate is Weight 25g / m ２ Up to 200 g / m ２ , or weight is 50 g / m ２ ~140g / m ２ , or weight is 60 g / m ２ ~120g / m ２ or a cellulosic paper having a weight of 5 g / m ２ ~100g / m ２ , or weight is 10 g / m ２ ~60g / m ２ , or weight is 15 g / m ２ ~50g / m ２ Nonwoven fabric The method of claim 1 , comprising:

3. the first resin type is selected from physically drying, radiation curable, thermal initiator induced polymerization, crosslinking between hydroxylated groups and free and / or blocked isocyanates, and any combination thereof; Where: When the first resin is configured to promote adhesion, the first resin has a weight percent of 1 g / m ２ ~30g / m ２ , or weight is 2 g / m ２ ~25g / m ２ , or weight is 5 g / m ２ ~20g / m ２ and When the first resin is configured to act as an adhesive, the first resin has a weight of 1 g / m ２ ~80g / m ２ , or weight is 20 g / m ２ ~60g / m ２ , or 25 g / m ２ ~55g / m ２ The amount of resin that permeates the substrate is 1 g / m ２ ~30g / m ２ , or the amount is 1 g / m ２ ~25g / m ２ , or the amount is 1 g / m ２ ~15g / m ２ That is, The method according to claim 1 or claim 2.

4. The method according to any one or more of claims 1 to 3, wherein during the third step, the drying and / or curing process is carried out by at least one process selected from UV curing, electron beam irradiation, physical drying.

5. 5. The method according to claim 1, wherein during the fourth step the radiation curable functional groups are accompanied by thermal initiators, and / or hydroxylated groups and free and / or blocked isocyanates.

6. 5. The method according to claim 1, wherein the anhydride resin comprising radiation-curable functional groups with which the substrate is impregnated in the fourth step comprises 50% or more of monomers having unsaturated acrylate and / or methacrylate groups, or more than 75% of monomers having unsaturated acrylate and / or methacrylate groups, or more than 85% of monomers having unsaturated acrylate and / or methacrylate groups.

7. 7. The method according to any one or more of the preceding claims, wherein in the fifth step, curing is carried out by electron beam with a dose of 1-90 kGy, alternatively with a dose of 10-80 kGy, alternatively with a dose of 20-60 kGy and a voltage of 80-300 kV, alternatively with a voltage of 100-300 kV, alternatively with a voltage of 120-250 kV.

8. 8. The method according to claim 7, wherein the curing is carried out under an inert atmosphere partially enriched with oxygen or may be carried out without inertization, such that oxygen partially or completely inhibits surface curing on at least one of the two faces of the foil.

9. 9. The method according to any one or more of the preceding claims, comprising an optional step of printing a decorative design on any of the faces, which can be carried out after the fifth step of curing and before the sixth step of applying one or more layers of one or more radiation curable resins.

10. Digital printing is used, where the ink is partially cured with UV light and / or an electron beam; 10. The method according to claim 9, wherein when partially cured, the image is fixed on the decorative foil, but at the same time at least a portion of the surface reactive groups remain active so as to be able to establish a covalent bond with a subsequent layer in a sixth step.

11. an optional step, before or after the sixth step, of applying one or more layers of one or more adhesion promoting and / or adhesive resins; A method according to any one or more of the preceding claims, wherein one or more layers of such one or more adhesion promoting and / or adhesive resins are applied to the face opposite to the face on which the sixth step has or will be performed, optionally followed by a drying and / or curing step.

12. the one or more adhesion promoting and / or adhesive layers are selected from physically drying, radiation curable, thermal initiator induced polymerization, crosslinking between hydroxylated groups and free and / or blocked isocyanates, and any combination thereof; When such resin or resins are configured to promote adhesion, they may be present in amounts of 1 g / m ２ ~30g / m ２ , or weight is 2 g / m ２ ~25g / m ２ , or weight is 2 g / m ２ ~10g / m ２ and When such resin or resins are configured to act as adhesives, they should have a weight of 10 g / m ２ ~80g / m ２ , or weight is 20 g / m ２ ~60g / m ２ , or weight is 25 g / m ２ ~55g / m ２ That is, The method of claim 11.

13. 13. The method according to any one of claims 1 to 12, wherein in the seventh step, curing is carried out by electron beam with a dose of 1 to 90 kGy, or with a dose of 10 kGy to 80 kGy, or with a dose of 20 kGy to 60 kGy and a voltage of 80 to 300 kV, or with a voltage of 100 kV to 300 kV, or with a voltage of 150 kV to 250 kV, said curing being carried out under physically inert conditions or under an inert atmosphere with an oxygen content of less than 1000 ppm, or with an oxygen content of less than 500 ppm, or with an oxygen content of less than 200 ppm.

14. The method of claim 1, wherein the radiation-curable functional groups are selected from unsaturated acrylate and methacrylate groups.

15. 15. The method according to claim 1, wherein the anhydride resin comprising radiation-curable functional groups in the sixth step is formed from an epoxy acrylate oligomer, or from a polyester acrylate oligomer, or from a urethane acrylate oligomer or the corresponding methacrylate oligomer, where appropriate diluted with mono- and / or polyfunctional acrylate monomers and / or their corresponding methacrylates.

16. The method according to any one or more of claims 1 to 15, wherein in the sixth step, the anhydride resin containing radiation curable functional groups is an aliphatic urethane acrylate oligomer appropriately diluted with diacrylate or triacrylate monomers.

17. Use of a decorative foil obtained by the method according to any one of claims 1 to 16 in a panel selected from HPL panels, CPL panels and 2D flat or curved elements backed with a finishing foil.